An air-conditioning device includes: a main circuit in which a refrigerant circulates; a flow channel-switching unit configured to select a certain parallel heat exchanger as a defrosting target; a bypass pipe; a temperature-detecting unit; an operation control unit configured to operate the flow channel-switching unit such that an operation mode is switched between a normal heating operation mode in which the plurality of parallel heat exchangers serve as evaporators and a defrosting heating operation mode in which one parallel heat exchanger is selected as the defrosting target to cause part of the refrigerant to flow thereinto via the bypass pipe and the other parallel heat exchangers serves as an evaporator; and an erroneous installation-sensing unit configured to sense erroneous installation of an installed component based on a magnitude relationship between the detected temperatures in the plurality of parallel heat exchangers detected by the temperature-detecting unit.

TECHNICAL FIELD

The present disclosure relates to an air-conditioning device.

BACKGROUND

Recently, heat pump type air-conditioning devices using air as a heat source have more often been installed instead of boiler type heating mechanisms that perform heating by burning fossil fuel in cold regions in view of global environmental conservation. A heat pump type air-conditioning device can efficiently perform heating with supply of heat from air in addition to supply of electric power to a compressor.

However, in such a heat pump type air-conditioning device, as the temperature of the outside air or the like becomes lower, frost is more likely to be attached to an outdoor heat exchanger serving as an evaporator and exchanging heat between outside air and a refrigerant. Accordingly, such a heat pump type air-conditioning device needs to perform defrosting by melting frost attached to the outdoor heat exchanger. As such a defrosting method, for example, a method of reversing the flow of a refrigerant in a heating mechanism and supplying the refrigerant from the compressor to the outdoor heat exchanger is known. In this method, since indoor heating stops while defrosting is being performed, comfort may be compromised.

Therefore, an air-conditioning device that can perform heating in a period of defrosting in which the outdoor heat exchanger are partitioned, defrosting is performed on some of the partitioned outdoor heat exchangers and the other partitioned outdoor heat exchangers are operated as evaporators to perform heating is proposed (for example, see Patent Document 1 and Patent Document 2).

In the aforementioned air-conditioning device according to the related art, the outdoor heat exchanger is partitioned into a plurality of parallel heat exchangers and a flow channel-switching unit such as a switching valve that switches a heat exchanger such that it operates as an evaporator or performs defrosting is provided. The air-conditioning device according to the related art performs defrosting without stopping heating by causing part of a refrigerant emitted from the compressor to flow into the heat exchanger having requested defrosting and to perform defrosting using the flow channel-switching unit.

PATENT DOCUMENT

Patent Document 1

Patent Document 2

However, for example, when the flow channel-switching unit is erroneously connected and attached to a heat exchanger other than a heat exchanger to which the flow channel-switching unit should be connected and attached, the air-conditioning device according to the related art may not sense erroneous installation of an installed component such as the flow channel-switching unit and may not perform defrosting normally.

SUMMARY

The present disclosure was invented to solve the aforementioned problem and an objective thereof is to provide an air-conditioning device that can sense erroneous installation of an installed component and perform defrosting normally without stopping heating of an indoor unit.

In order to achieve the aforementioned objective, according to an aspect of the present disclosure, an air-conditioning device is provided, including: a main circuit in which a compressor, an indoor heat exchanger, a decompressor, and a plurality of parallel heat exchangers connected in parallel are connected by a pipe and in which a refrigerant circulates; a flow channel-switching unit connected to the plurality of parallel heat exchangers and configured to select a certain parallel heat exchanger out of the plurality of parallel heat exchangers as a defrosting target for defrosting by melting frost attached to the parallel heat exchanger; a bypass pipe configured to cause part of a refrigerant emitted from the compressor to flow into the parallel heat exchanger selected as the defrosting target by the flow channel-switching unit; a temperature-detecting unit configured to detect temperatures of the refrigerant in the plurality of parallel heat exchangers; an operation control unit configured to operate the flow channel-switching unit such that an operation mode is switched between a normal heating operation mode in which the plurality of parallel heat exchangers serve as evaporators and a defrosting heating operation mode in which one parallel heat exchanger out of the plurality of parallel heat exchangers is selected as the defrosting target to cause part of the refrigerant to flow thereinto via the bypass pipe and the other parallel heat exchangers serves as an evaporator; and an erroneous installation-sensing unit configured to sense erroneous installation of an installed component associated with the defrosting based on a magnitude relationship between the detected temperatures in the plurality of parallel heat exchangers detected by the temperature-detecting unit.

According to the present disclosure, it is possible to sense erroneous installation of an installed component associated with defrosting and to perform defrosting normally without stopping heating of an indoor unit.

DETAILED DESCRIPTION

Hereinafter, an air-conditioning device according to embodiments of the present disclosure are described with reference to the accompanying drawings.

First Embodiment

FIG.1is a drawing illustrating an example of a configuration of an air-conditioning device100according to a first embodiment of the present disclosure.

As illustrated inFIG.1, the air-conditioning device100includes an outdoor unit10, an indoor unit20, and a control device60.

The outdoor unit10is a heat source unit that generates heat which is supplied to the indoor unit20and serves as a heat source-side unit.

The indoor unit20serves as a load-side unit that uses heat supplied from the outdoor unit10. The indoor unit20includes an indoor heat exchanger21and an indoor fan22.

The outdoor unit10and the indoor unit20are connected to each other by a first extension pipe32and a second extension pipe33.

The indoor heat exchanger21performs exchange of heat with indoor air using heat supplied from the outdoor unit10.

The indoor fan22carries indoor air to the indoor heat exchanger21. That is, the indoor fan22is an air blower that blows indoor air to the indoor heat exchanger21.

The outdoor unit10includes a compressor11, a cooling/heating-switching unit12, a first decompressor13, a plurality of parallel heat exchangers14(14-1and14-2), a receiver15, a third decompressor16, a plurality of second decompressors17(17-1and17-2), a flow rate-adjusting device18, an outdoor fan19, a flow channel-switching unit and a plurality of temperature-detecting units51(51-1and51-2).

The air-conditioning device100includes a main circuit RC which is a refrigerant circuit for circulating a refrigerant between the outdoor unit10and the indoor unit20.

The main circuit RC has a configuration in which the constituents of the main circuit RC included in the outdoor unit10and the indoor unit20are connected by an emission pipe31, a first extension pipe32, a second extension pipe33, a first connection pipe34, a second connection pipe35, and an intake pipe36.

The refrigerant used for the main circuit RC is, for example, a Freon refrigerant or a hydrofluoroolefin refrigerant (an HFO refrigerant). Examples of the Freon refrigerant include an R32 refrigerant, an R125 refrigerant and an R134a refrigerant, which are chlorofluorocarbon-based refrigerants (HFC-based refrigerants), and an R410A refrigerant, an R407c refrigerant and an R404A refrigerant, which are mixed refrigerants thereof. Examples of the HFO refrigerant include HFO-1234yf, HFO-1234 ze(E) and HFO-1234 ze(Z).

The main circuit RC has a configuration in which the compressor11, the cooling/heating-switching unit12, the indoor heat exchanger21, the first decompressor13, the parallel heat exchanger14-1, and the parallel heat exchanger14-2are sequentially connected by a pipe.

The compressor11is connected between the intake pipe36and the emission pipe31. The compressor11compresses a refrigerant supplied via the intake pipe36and emits a high-temperature high-pressure refrigerant to the emission pipe31.

The cooling/heating-switching unit12is connected between the emission pipe31and the intake pipe36and switches a flow direction of the refrigerant. The cooling/heating-switching unit12is constituted, for example, by a four-way valve. The emission side of the compressor11and the cooling/heating-switching unit12are connected by the emission pipe31. The intake side of the compressor11and the cooling/heating-switching unit12are connected by the intake pipe36.

In a heating operation, the cooling/heating-switching unit12connects the emission pipe31and the first extension pipe32, connects the emission side of the compressor11and the indoor heat exchanger21, connects the intake pipe36and the second connection pipes35(35-1,35-2), and connects the intake side of the compressor11and the parallel heat exchangers14(14-1,14-2).

In a cooling operation, the cooling/heating-switching unit12connects the emission pipe31and the second connection pipes35(35-1,35-2), connects the emission side of the compressor11and the parallel heat exchangers14(14-1,14-2), connects the intake pipe36and the first connection pipe32, and connects the intake side of the compressor11and the indoor heat exchanger21.

In this embodiment, the switching state of the cooling/heating-switching unit12in the cooling operation is referred to as switching A, and the switching state of the cooling/heating-switching unit12in the heating operation is referred to as switching B.

The first decompressor13is connected to the indoor heat exchanger21by the second extension pipe33and decompresses and expands the refrigerant.

The receiver15is disposed between the first decompressor13and the third decompressor16and is a tank in which a liquid refrigerant is stored.

The plurality of parallel heat exchangers14(14-1and14-2) are disposed in parallel between the cooling/heating-switching unit12and the second decompressors17(17-1,17-2) and are, for example, outdoor heat exchangers that perform exchange of heat between outside air and the refrigerant.

In this embodiment, the parallel heat exchanger14-1and the parallel heat exchanger14-2are referred to as parallel heat exchangers14when they indicate arbitrary parallel heat exchangers of the air-conditioning device100or when they are not particularly distinguished.

The parallel heat exchanger14-1is connected between the first connection pipe34-1and the second connection pipe35-1. The parallel heat exchanger14-2is connected between the first connection pipe34-2and the second connection pipe35-2.

In this embodiment, the first connection pipe34-1and the first connection pipe34-2are referred to as first connection pipes34when they indicate arbitrary first connection pipes of the air-conditioning device100or when they are not particularly distinguished. In this embodiment, the second connection pipe35-1and the second connection pipe35-2are referred to as second connection pipes35when they indicate arbitrary second connection pipes of the air-conditioning device100or when they are not particularly distinguished.

A detailed configuration of the parallel heat exchanger14(14-1,14-2) are described below with reference toFIG.2.

FIG.2is a drawing illustrating an example of a configuration of the parallel heat exchanger14(14-1,14-2) according to this embodiment.

As illustrated inFIG.2, the parallel heat exchanger14(14-1,14-2) is constituted, for example, as a finned tube type heat exchanger including a plurality of heat transfer tubes14aand a plurality of fins14b. Here, it is assumed that the outdoor heat exchanger is divided into two parallel heat exchangers14(14-1,14-2).

A plurality of heat transfer tubes14athrough which a refrigerant passes therein are provided in a stepped direction perpendicular to an air-passing direction and provided in a column direction parallel to the air-passing direction.

The fins14bare disposed at intervals such that air passes in the air-passing direction. The fins14bmay have an integral shape which is not divided into the parallel heat exchanger14-1and the parallel heat exchanger14-2or may be divided into the parallel heat exchanger14-1and the parallel heat exchanger14-2as illustrated inFIG.2.

The parallel heat exchangers14(14-1,14-2) are divided in the up-and-down direction in a casing of the outdoor unit10. The parallel heat exchangers14may be divided in a left-and-right direction or may be divided in the up-and-down direction as illustrated inFIG.2. When the parallel heat exchanger14is divided in the left-and-right direction, refrigerant inlets to the parallel heat exchanger14-1and the parallel heat exchanger14-2are located at both ends in the left-and-right direction of the outdoor unit10and thus pipe connection of the parallel heat exchangers14is complicated, but water generated through defrosting does not become attached to the other heat exchangers.

When the parallel heat exchanger14is divided in the up-and-down direction, pipe connection is facilitated, but water generated from the upper heat exchanger flows down to the lower heat exchanger and thus there is a likelihood that heat exchange may be inhibited because water generated through defrosting in the upper heat exchanger becomes frozen in the lower heat exchanger when the lower heat exchanger serves as an evaporator while defrosting of the upper heat exchanger is being performed.

Referring back toFIG.1, the third decompressor16is disposed between the receiver15and two parallel heat exchangers14(14-1,14-2). The third decompressor16decompresses and expands a refrigerant.

The second decompressors17(17-1,17-2) are disposed between the parallel heat exchangers14(14-1,14-2) and the third decompressor16and decompress and expand the refrigerant. The second decompressor17-1is connected to the parallel heat exchanger14-1via the first connection pipe34-1. The second decompressor17-2is connected to the parallel heat exchanger14-2via the first connection pipe34-2. The second decompressor17may be configured to only decompress a refrigerant and thus may be a capillary tube, an expansion valve, or the like.

In this embodiment, the second decompressor17-1and the second decompressor17-2are referred to as second decompressors17when they indicate arbitrary second decompressors of the air-conditioning device100or when they are not particularly distinguished.

The flow channel-switching unit40is connected to the two parallel heat exchangers14and selects one parallel heat exchanger14of the two parallel heat exchangers14as a defrosting target. Here, a defrosting target is a target to be defrosted such that frost attached to the parallel heat exchanger14is melted. The flow channel-switching unit40is disposed in the second connection pipes35(35-1,35-2) between the emission side of the compressor11(the cooling/heating-switching unit12) and the two parallel heat exchangers14(14-1,14-2).

The flow channel-switching unit40includes a first on/off-switching device41-1, a first on/off-switching device41-2, a second on/off-switching device42-1, and a second on/off-switching device42-2.

The first on/off-switching device41-1is disposed between the cooling/heating-switching unit12and the second connection pipe35-1. The first on/off-switching device41-1is, for example, an on/off valve and connects or disconnects a flow channel between the cooling/heating-switching unit12and the second connection pipe35-1.

The first on/off-switching device41-2is disposed between the cooling/heating-switching unit12and the second connection pipe35-2. The first on/off-switching device41-1is, for example, an on/off valve and connects or disconnects a flow channel between the cooling/heating-switching unit12and the second connection pipe35-2.

The second on/off-switching device42-1is disposed between the emission side of the compressor11and the second connection pipe35-1. The second on/off-switching device42-1is, for example, an on/off valve and connects or disconnects a flow channel between a bypass pipe37on the emission side of the compressor11and the second connection pipe35-1.

The second on/off-switching device42-2is disposed between the emission side of the compressor11and the second connection pipe35-2. The second on/off-switching device42-2is, for example, an on/off valve and connects or disconnects a flow channel between a bypass pipe37on the emission side of the compressor11and the second connection pipe35-2.

The refrigerant circuit of the air-conditioning device100includes a bypass pipe37that supplies part of a high-temperature high-pressure refrigerant emitted from the compressor11to the two parallel heat exchangers14.

The bypass pipe37branches part of the refrigerant emitted from the compressor11to flow into the parallel heat exchanger14selected as a defrosting target by the flow channel-switching unit40. For example, one end of the bypass pipe37is connected to the emission pipe31and the other end thereof is branched and is connected to the second connection pipes35(35-1,35-2).

The flow rate-adjusting device18is disposed between the emission pipe31and the bypass pipe37and adjusts a flow rate of the refrigerant flowing in the bypass pipe37.

The outdoor fan19is an air blower that blows air to the plurality of parallel heat exchangers14. The outdoor fan19sends outside air to the parallel heat exchangers14.

The plurality of temperature-detecting units51(51-1,51-2) are, for example, temperature sensors and detect the temperature of the refrigerant in the plurality of parallel heat exchangers14. Each temperature-detecting unit51detects the temperature of a refrigerant evaporating or being used for defrosting in the corresponding parallel heat exchanger14.

In this embodiment, the temperature-detecting unit51-1and the temperature-detecting unit51-2have the same configuration and are referred to as the temperature-detecting units51when they indicate arbitrary temperature-detecting units of the air-conditioning device100or when they are not particularly distinguished.

The temperature-detecting unit51-1is disposed in the parallel heat exchanger14-1and detects a temperature of a refrigerant in the parallel heat exchanger14-1. The temperature-detecting unit51-2is disposed in the parallel heat exchanger14-2and detects a temperature of a refrigerant in the parallel heat exchanger14-2.

The temperature-detecting units51(51-1,51-2) may be disposed in the first connection pipes34(34-1,34-1) or the second connection pipes35(35-1,35-2). Each temperature-detecting unit51may detect a pressure of a refrigerant using a pressure detector instead of a temperature sensor and indirectly detect the temperature of the refrigerant using a saturation temperature thereof.

The control device60includes, for example, a central processing unit (CPU) and controls operations of various control units and switching of an operation mode. The control device60includes, for example, control boards installed in the outdoor unit10and the indoor unit20and a remote controller provided indoors.

The control device60includes an operation control unit61, an erroneous installation-sensing unit62, and a notification output unit63.

The operation control unit61controls operations of various control units and switching of the operation mode. The operation control unit61operates the cooling/heating-switching unit12such that the operation mode switches between a cooling operation mode and a heating operation mode. Here, the cooling operation mode is an operation mode in which the air-conditioning device100performs a cooling operation. The heating operation mode is an operation mode in which the air-conditioning device100performs a heating operation. The heating operation mode includes a normal heating operation mode and a defrosting heating operation mode. In the following description, the defrosting heating operation mode may be referred to as a continuous heating operation mode.

The operation control unit61controls the cooling/heating-switching unit12such that switching A is set when the operation mode is switched to the cooling operation mode. The operation control unit61controls the cooling/heating-switching unit12such that switching B is set when the operation mode is switched to the heating operation mode.

The operation control unit61operates the flow channel-switching unit40to switch between the normal heating operation mode and the defrosting heating operation mode. Here, the normal heating operation mode is an operation mode in which both the parallel heat exchangers14serve as evaporators and is a normal heating operation mode. That is, in the normal heating operation mode, both the parallel heat exchanger14-1and the parallel heat exchanger14-2operate as normal evaporators.

The defrosting heating operation mode is an operation mode in which one parallel heat exchanger14of the plurality of parallel heat exchangers14is selected as defrosting target, part of the refrigerant is caused to flow therein via the bypass pipe37, and the other parallel heat exchanger14serves as an evaporator. In the defrosting heating operation mode, defrosting is performed on one of the parallel heat exchanger14-1and the parallel heat exchanger14-2while continuing to perform the heating operation.

For example, when the operation mode is switched to the normal heating operation mode, the operation control unit61sets the first on/off-switching device41-1and the first on/off-switching device41-2to an ON state and sets the second on/off-switching device42-1and the second on/off-switching device42-2to an OFF state. In this case, the parallel heat exchanger14-1and the parallel heat exchanger14-2serve as evaporators.

When the parallel heat exchanger14-1is selected as a defrosting target in the defrosting heating operation mode, the operation control unit61sets the first on/off-switching device41-1to the OFF state, sets the second on/off-switching device42-1to the ON state, sets the first on/off-switching device41-2to the ON state, and sets the second on/off-switching device42-2to the OFF state. In this case, the parallel heat exchanger14-1is subjected to defrosting and the parallel heat exchanger14-2serves as an evaporator.

When the parallel heat exchanger14-2is selected as a defrosting target in the defrosting heating operation mode, the operation control unit61sets the first on/off-switching device41-2to the OFF state, sets the second on/off-switching device42-2to the ON state, sets the first on/off-switching device41-1to the ON state, and sets the second on/off-switching device42-1to the OFF state. In this case, the parallel heat exchanger14-2is subjected to defrosting and the parallel heat exchanger14-1serves as an evaporator.

The operation control unit61determines whether defrosting is completed, for example, based on the detected temperature of the refrigerant in the parallel heat exchanger14serving as a defrosting target detected by the temperature-detecting unit51(51-1,51-2). The operation control unit61determines that defrosting of the parallel heat exchanger14serving as a defrosting target is completed, for example, when the detected temperature of the refrigerant in the parallel heat exchanger14serving as a defrosting target is higher than the melting temperature of frost (0° C.).

The erroneous installation-sensing unit62senses erroneous installation of an installed component associated with defrosting based on the detected temperatures in the plurality of parallel heat exchangers14detected by the temperature-detecting unit51. That is, the erroneous installation-sensing unit62performs an erroneous installation-sensing process of sensing erroneous installation of an installed component associated with defrosting in a state in which the operation mode is switched to the defrosting heating operation mode. Examples of the installed component associated with defrosting include the flow channel-switching unit40and the temperature-detecting units51.

The erroneous installation-sensing unit62senses that the flow channel-switching unit40or the temperature-detecting unit51is erroneously installed when the detected temperature in the parallel heat exchanger14serving as a defrosting target is equal to or lower than the detected temperature in the parallel heat exchanger14serving as an evaporator.

When erroneous installation of an installed component is sensed, the erroneous installation-sensing unit62causes the notification output unit63to output notification information based on the sensing result of erroneous installation of an installed component. That is, the erroneous installation-sensing unit62notifies the outside of the air-conditioning device100that erroneous installation is sensed using the notification output unit63.

The notification output unit63is, for example, a display unit of a remote controller or a speaker for outputting alarm sound. The notification output unit63outputs the sensing result from the erroneous installation-sensing unit62. For example, when the notification output unit63is a display unit of a remote controller, the notification output unit63displays notification information based on the sensing result of erroneous installation of an installed component. The sensing result of erroneous installation includes a sensing result indicating normal installation.

States of the cooling/heating-switching unit12and the flow channel-switching unit40corresponding to the operation modes of the air-conditioning device100are described below with reference toFIG.3.

FIG.3is a drawing illustrating states of the cooling/heating-switching unit12and the flow channel-switching unit40corresponding to the operation modes of the air-conditioning device100according to this embodiment.

InFIG.3, an “ON” state of each of the first on/off-switching device41-1, the first on/off-switching device41-2, the second on/off-switching device42-1, and the second on/off-switching device42-2of the flow channel-switching unit40represents a state in which both ends thereof are connected, and an “OFF” state thereof represents a state in which both ends thereof are disconnected. A path using the second connection pipe35-1is referred to as “path 1,” and a case in which the parallel heat exchanger14-1is selected as a defrosting target and defrosting is performed via the path using the second connection pipe35-1is referred to as “path 1-side defrosting.” A path using the second connection pipe35-1is referred to as “path 2,” and a case in which the parallel heat exchanger14-2is selected as a defrosting target and defrosting is performed via the path using the second connection pipe35-2is referred to as “path 2-side defrosting.”

For example, when the operation mode is the cooling operation mode, the operation control unit61sets the cooling/heating-switching unit12to “switching A,” sets the first on/off-switching device41-1and the first on/off-switching device41-2to the “ON” state, and sets the second on/off-switching device42-1and the second on/off-switching device42-2to the “OFF” state.

For example, when the operation mode is the normal heating operation mode, the operation control unit61sets the cooling/heating-switching unit12to “switching B,” sets the first on/off-switching device41-1and the first on/off-switching device41-2to the “ON” state, and sets the second on/off-switching device42-1and the second on/off-switching device42-2to the “OFF” state.

For example, when the operation mode is the defrosting heating operation mode and Path 1 is selected as a defrosting target (when “Path 1-side defrosting” is performed), the operation control unit61sets the cooling/heating-switching unit12to “switching B,” sets the first on/off-switching device41-1to the “OFF” state, and sets the first on/off-switching device41-2to the “ON” state. In this case, the operation control unit61sets the second on/off-switching device42-1to the “ON” state and sets the second on/off-switching device42-2to the “OFF” state.

For example, when the operation mode is the defrosting heating operation mode and Path 2 is selected as a defrosting target (when “Path 2-side defrosting” is performed), the operation control unit61sets the cooling/heating-switching unit12to “switching B,” sets the first on/off-switching device41-1to the “ON” state, and sets the first on/off-switching device41-2to the “OFF” state. In this case, the operation control unit61sets the second on/off-switching device42-1to the “OFF” state and sets the second on/off-switching device42-2to the “ON” state.

Operations of the air-conditioning device100according to this embodiment are described below with reference to the drawings. The operation in the cooling operation mode of the air-conditioning device100are first described.

FIG.4is a drawing illustrating the flow of a refrigerant in the cooling operation mode of the air-conditioning device100according to this embodiment. InFIG.4, parts in which a refrigerant flows in the cooling operation mode are indicated by a solid line, and parts in which a refrigerant does not flow are indicated by a dashed line.

FIG.5is a P-h drawing in the cooling operation mode of the air-conditioning device100according to this embodiment. InFIG.5, the vertical axis represents a pressure P [MPa (megapascal)] of a refrigerant, and the horizontal axis represents specific enthalpy h [kJ (kilojoule)/kg (kilogram)]. Points P1to P4inFIG.5represent refrigerant states in the parts referred to by the same reference signs inFIG.4.

InFIG.5, when the compressor11starts its operation, the compressor11compresses a low-temperature low-pressure gas refrigerant and emits a high-temperature high-pressure gas refrigerant. The refrigerant compression process in the compressor11is performed such that the gas refrigerant is more heated by the adiabatic efficiency of the compressor11in comparison with a case in which the refrigerant is adiabatically compressed along an isoentropic line and is indicated by a line extending from the point P1to the point P2inFIG.5.

The high-temperature high-pressure gas refrigerant emitted from the compressor11branches into two refrigerants while passing through the cooling/heating-switching unit12and passes through the first on/off-switching device41-1and the first on/off-switching device41-2. The gas refrigerants passing through the first on/off-switching device41-1and the first on/off-switching device41-2flow into the parallel heat exchanger14-1and the parallel heat exchanger14-2connected thereto via the second connection pipe35-1and the second connection pipe35-2.

The parallel heat exchanger14-1and the parallel heat exchanger14-2cool the refrigerant flowing thereinto while heating the outside air. As a result, the refrigerants change to intermediate-temperature high-pressure liquid refrigerants. The refrigerant change in the parallel heat exchanger14-1and the parallel heat exchanger14-2is indicated by a slightly oblique straight line extending approximately horizontally and extending from the point P2to the point P3inFIG.5in consideration of a pressure loss.

The intermediate-temperature high-pressure liquid refrigerants flowing out from the parallel heat exchanger14-1and the parallel heat exchanger14-2flow into the first connection pipe34-1and the first connection pipe34-2, pass through the second decompressor17-1and the second decompressor17-2, and then merge. The merged refrigerant is expanded and decompressed and falls into a low-temperature low-pressure state with two phases of gas and liquid while passing through the third decompressor16, the receiver15, and the first decompressor13. Change of the refrigerant in the second decompressor17-1, the second decompressor17-2, the third decompressor16, the receiver15, and the first decompressor13is carried out with constant enthalpy. The refrigerant change at this time is indicated by a vertical line extending from the point P3to the point P4inFIG.5.

The refrigerant in the low-temperature low-pressure state with two phases of gas and liquid flowing out from the first decompressor13flows out from the outdoor unit10, passes through the second extension pipe33, and flows into the indoor heat exchanger21of the indoor unit20. The indoor heat exchanger21heats the flowed refrigerant while cooling the inside air. As a result, the refrigerant changes to a low-temperature low-pressure gas refrigerant. The refrigerant change in the indoor heat exchanger21is indicated by a slightly oblique straight line extending approximately horizontally and extending from the point P4to the point P1inFIG.5in consideration of a pressure loss.

The low-temperature low-pressure gas refrigerant flowing out from the indoor heat exchanger21returns to the outdoor unit10via the first extension pipe32, flows into the compressor11via the cooling/heating-switching unit12, and is compressed therein.

FIG.6is a drawing illustrating the flow of a refrigerant in the normal heating operation mode of the air-conditioning device100according to this embodiment. InFIG.6, parts in which a refrigerant flows in the normal heating operation mode are indicated by a solid line, and parts in which a refrigerant does not flow are indicated by a dashed line.

FIG.7is a P-h drawing in the normal heating operation mode of the air-conditioning device100according to this embodiment. InFIG.7, the vertical axis represents a pressure P [MPa] of a refrigerant, and the horizontal axis represents specific enthalpy h [kJ/kg]. Points P11to P14inFIG.7represent refrigerant states in the parts referred to by the same reference signs inFIG.6.

InFIG.6, when the compressor11starts its operation, the compressor11compresses a low-temperature low-pressure gas refrigerant and emits a high-temperature high-pressure gas refrigerant. The refrigerant compression process in the compressor11is indicated by a line extending from the point P11to the point P12inFIG.7.

The high-temperature high-pressure gas refrigerant emitted from the compressor11passes through the cooling/heating-switching unit12and flows out from the outdoor unit10. The high-temperature high-pressure gas refrigerant flowing out from the outdoor unit10flows into the indoor heat exchanger21of the indoor unit20via the first extension pipe32.

The indoor heat exchanger21cools the refrigerant flowing thereinto while heating the inside air. As a result, the refrigerant change to an intermediate-temperature high-pressure liquid refrigerant. The refrigerant change in the indoor heat exchanger21is indicated by a slightly oblique straight line extending approximately horizontally and extending from the point P12to the point P13inFIG.7in consideration of a pressure loss.

The intermediate-temperature high-pressure liquid refrigerant flowing out from the indoor heat exchanger21returns to the outdoor unit10via the second extension pipe33. The refrigerant returning to the outdoor unit10passes through the first decompressor13, the receiver15, and the third decompressor16and branches, and the branched refrigerants flow into the second decompressor17-1and the second decompressor17-2via the first connection pipe34-1and the first connection pipe34-2. The refrigerants are expanded and decompressed and falls into a low-temperature low-pressure state with two phases of gas and liquid while passing through the first decompressor13, the third decompressor16, and the second decompressor17. Change of the refrigerant in the first decompressor13, the third decompressor16, and the second decompressor17is carried out with constant enthalpy. The refrigerant change at this time is indicated by a vertical line extending from the point P13to the point P14inFIG.7.

The refrigerants flowing out from the second decompressor17-1and the second decompressor17-2flows into the parallel heat exchanger14-1and the parallel heat exchanger14-2. The parallel heat exchanger14-1and the parallel heat exchanger14-2heats the refrigerants while cooling the outside air. As a result, the refrigerants change to low-temperature low-pressure gas refrigerants. The refrigerant change in the parallel heat exchanger14-1and the parallel heat exchanger14-2is indicated by a slightly oblique straight line extending approximately horizontally and extending from the point P14to the point P11inFIG.7in consideration of a pressure loss.

The low-temperature low-pressure gas refrigerants flowing out from the parallel heat exchanger14-1and the parallel heat exchanger14-2flow into the second connection pipe35-1and the second connection pipe35-2, pass through the first on/off-switching device41-1and the first on/off-switching device41-2and then merge, and the merged refrigerant flows into the compressor11via the cooling/heating-switching unit12and is compressed therein.

The defrosting heating operation mode is carried out when the parallel heat exchanger14is frosted in the normal heating operation mode. The operation control unit61of the control device60determines whether the parallel heat exchanger14is frosted and determines whether a defrosting heating operation needs to be carried out based on the result of determination. The operation control unit61determines whether the parallel heat exchanger14is frosted, for example, based on a refrigerant saturation temperature to which a suction pressure of the compressor11is converted.

For example, when a refrigerant saturation temperature is much lower than a set outside air temperature and is less than a threshold value, the operation control unit61determines that the parallel heat exchanger14has frost requiring defrosting. For example, when a temperature difference between the outside air temperature and an evaporation temperature is equal to or greater than a preset value and an elapsed time in that state is equal to or greater than a predetermined period, the operation control unit61determines that the parallel heat exchanger14has frost requiring defrosting. The determination of whether there is frost is not limited to this determination method, and may be performed using another method.

When it is determined that the parallel heat exchanger14is frosted, the operation control unit61determines that a starting condition for starting the defrosting heating operation is satisfied. When it is determined that the start condition is satisfied, the operation control unit61switches the operation mode to the defrosting heating operation mode.

With the configuration of the air-conditioning device100according to this embodiment, it is possible to perform a continuous heating operation in which the parallel heat exchanger14-2is selected as a defrosting target and is subjected to defrosting (Path 2-side defrosting) and the parallel heat exchanger14-1serves as an evaporator in the defrosting heating operation mode. Also, on the other hand, it is possible to perform an operation in which the parallel heat exchanger14-1is selected as a defrosting target and is subjected to defrosting (path 1-side defrosting) and the parallel heat exchanger14-2serves as an evaporator.

The operation in which path 1-side defrosting is performed and the operation in which path 2-side defrosting is performed are the same except that the on/off states of the first on/off-switching device41-1, the first on/off-switching device41-2, the second on/off-switching device42-1, and the second on/off-switching device42-2are different, and the parallel heat exchanger14serving as a defrosting target and the parallel heat exchanger14serving as an evaporator are exchanged to change the flow of the refrigerant in the parallel heat exchangers14. Accordingly, in the following description, it is assumed that the continuous heating operation in which defrosting of the parallel heat exchanger14-2(path 2-side defrosting) is performed and the parallel heat exchanger14-1serves as an evaporator is performed. The same is assumed in the following description of embodiments.

FIG.8is a drawing illustrating the flow of a refrigerant in the defrosting heating operation mode of the air-conditioning device100according to this embodiment. In the example illustrated inFIG.8, path 2-side defrosting is performed, parts in which a refrigerant flows in the defrosting heating operation mode are indicated by a solid line, and parts in which a refrigerant does not flow are indicated by a dashed line.

FIG.9is a P-h drawing in the defrosting heating operation mode of the air-conditioning device100according to this embodiment. InFIG.9, the vertical axis represents a pressure P [MPa] of a refrigerant, and the horizontal axis represents specific enthalpy h [kJ/kg]. Points P21to P29inFIG.9represent refrigerant states in the parts referred to by the same reference signs inFIG.8.

The operation control unit61turns off the first on/off-switching device41-2corresponding to the parallel heat exchanger14-2serving as a defrosting target in the defrosting heating operation mode in which defrosting of the parallel heat exchanger14-2is performed. The operation control unit61turns on the second on/off-switching device42-2and turns on the flow rate-adjusting device18. The operation control unit61turns on the first on/off-switching device41-1corresponding to the parallel heat exchanger14-1serving as an evaporator and turns off the second on/off-switching device42-1.

Accordingly, a defrosting circuit with sequential connection of the compressor11, the flow rate-adjusting device18, the second on/off-switching device42-2, the parallel heat exchanger14-2and the second decompressor17-2is turned on and the defrosting heating operation is performed.

InFIG.8, when the defrosting heating operation is performed, part of a high-temperature high-pressure gas refrigerant emitted from the compressor11flows into the bypass pipe37and is decompressed to an intermediate pressure by the flow rate-adjusting device18. The refrigerant change at this time is indicated by a line extending from the point P22to the point P25inFIG.9.

Then, the refrigerant decompressed to the intermediate pressure at the point P25flows into the parallel heat exchanger14-2via the second on/off-switching device42-2. The refrigerant flowing into the parallel heat exchanger14-2is cooled by exchange of heat with frost attached to the parallel heat exchanger14-2.

In this way, by decompressing the high-temperature high-pressure gas refrigerant emitted from the compressor11and then causing the refrigerant to flow into the parallel heat exchanger14-2, frost attached to the parallel heat exchanger14-2can be melted. The refrigerant change at this time is indicated by a line extending from the point P25to the point P26inFIG.9.

After defrosting is performed, the refrigerant flowing out from the parallel heat exchanger14-2is decompressed while passing through the second decompressor17-2. The refrigerant change at this time is indicated by a line extending from the point P26to the point P27inFIG.9.

The refrigerant passing through the second decompressor17-2merges into that in the main circuit RC. The merged refrigerant passes through the second decompressor17-1, flows into the parallel heat exchanger14-1serving as an evaporator, and is evaporated.

When defrosting of the parallel heat exchanger14-2is completed, the operation control unit61controls the on/off states of the first on/off-switching device41-1, the first on/off-switching device41-2, the second on/off-switching device42-1, and the second on/off-switching device42-2such that defrosting of the parallel heat exchanger14-1is performed or the operation mode is switched to the normal heating operation mode.

The operation control unit61determines completion of defrosting based on the temperature detected by the temperature-detecting unit51-2. The operation control unit61determines the completion of defrosting, for example, when the detected temperature is higher than a predetermined value higher than a frost melting temperature (0° C.).

The erroneous installation-sensing process of the air-conditioning device100according to this embodiment are described below.

Here, an influence when the temperature-detecting unit51(51-1,51-2) or the flow channel-switching unit40(the first on/off-switching device41-1, the first on/off-switching device41-2, the second on/off-switching device42-1, and the second on/off-switching device42-1) is erroneously installed (erroneous installation is performed) are first described below.

For example, when the temperature-detecting unit51-1and the temperature-detecting unit51-2are inversely installed, the refrigerant temperature of the parallel heat exchanger14-2serving as a defrosting target is detected by the temperature-detecting unit51-1, and the refrigerant temperature of the parallel heat exchanger14-1serving as an evaporator is detected by the temperature-detecting unit51-1. In this case, the refrigerant temperature of the parallel heat exchanger14-1serving as an evaporator is lower than 0° C., which is a frosting temperature, and the temperature-detecting unit51-2detects the temperature lower than 0° C. Accordingly, since the temperature detected by the temperature-detecting unit51-2for determining completion of defrosting is not higher than 0° C., which is a frost melting temperature, the operation control unit61cannot correctly determine completion of defrosting.

Also, for example, when the second on/off-switching device42-1and the second on/off-switching device42-2are inversely installed, the second on/off-switching device42-2is connected to the second connection pipe35-1. Accordingly, since the high-temperature refrigerant passing through the second on/off-switching device42-2does not flow into the parallel heat exchanger14-1and flows into the compressor11via the first on/off-switching device41-1, the operation control unit61cannot perform defrosting of either of the parallel heat exchanger14-1and the parallel heat exchanger14-2.

Therefore, the air-conditioning device100according to this embodiment performs the erroneous installation-sensing process of sensing erroneous installation of the temperature-detecting unit51(51-1,51-2) or the flow channel-switching unit40(the first on/off-switching device41-1, the first on/off-switching device41-2, the second on/off-switching device42-1, and the second on/off-switching device42-1).

The erroneous installation-sensing process in the air-conditioning device100according to this embodiment are described below with reference toFIG.10.

FIG.10is a flowchart illustrating an example of the erroneous installation-sensing process in the air-conditioning device100according to this embodiment.

The air-conditioning device100performs the erroneous installation-sensing process illustrated inFIG.10when a starting condition of the erroneous installation-sensing process is satisfied. Examples of the starting condition of the erroneous installation-sensing process include a condition in which the defrosting heating operation is first performed after being powered on, a condition in which the starting is instructed by operating a remote controller or a mobile terminal, and a condition in which the starting is instructed by a switch such as a button switch or a DIP switch provided on a control board of the outdoor unit10. When the process is started by operating the remote controller or the mobile terminal or the starting is instructed from a switch on the control board, there is an advantage in that the process can be performed at an arbitrary timing by an operator at the time of constructing or maintenance of the outdoor unit10.

As illustrated inFIG.10, the operation control unit61of the control device60first performs the defrosting heating operation in which the parallel heat exchanger14-2is selected as a defrosting target (Step S101). That is, the operation control unit61sets the cooling/heating-switching unit12to switching B, sets the first on/off-switching device41-1and the second on/off-switching device42-2to the ON state, and sets the first on/off-switching device41-2and the second on/off-switching device42-1to the OFF state. The operation control unit61turns on the flow rate-adjusting device18to start the operation of the compressor11.

Then, the erroneous installation-sensing unit62of the control device60determines whether the detected temperature T2is higher than the detected temperature T1(Step S102). The erroneous installation-sensing unit62acquires the detected temperature T1in the parallel heat exchanger14-1from the temperature-detecting unit51-1and acquires the detected temperature T2in the parallel heat exchanger14-2from the temperature-detecting unit51-2. That is, the erroneous installation-sensing unit62acquires the detected temperature T1detected by the temperature-detecting unit51-1and the detected temperature T2detected by the temperature-detecting unit51-2. The erroneous installation-sensing unit62compares the detected temperature T1in the parallel heat exchanger14-1and the detected temperature T2in the parallel heat exchanger14-2and determines whether the detected temperature T2is higher than the detected temperature T1. When the detected temperature T2is higher than the detected temperature T1(Step S102: YES), the erroneous installation-sensing unit62causes the process to proceed to Step S103. When the detected temperature T2is equal to or lower than the detected temperature T1(Step S102: NO), the erroneous installation-sensing unit62causes the process to proceed to Step S104.

In Step S103, the erroneous installation-sensing unit62notifies the outside of normal installation. In this case, the erroneous installation-sensing unit62causes the notification output unit63to output notification information indicating that installation of the temperature-detecting unit51(51-1,51-2) and the flow channel-switching unit40(the first on/off-switching device41-1, the first on/off-switching device41-2, the second on/off-switching device42-1, and the second on/off-switching device42-1) is normal and notifies the outside of the normal installation. After the process of Step S103is performed, the erroneous installation-sensing unit62ends the erroneous installation-sensing process.

In Step S104, the erroneous installation-sensing unit62notifies the outside of erroneous installation. In this case, the erroneous installation-sensing unit62causes the notification output unit63to output notification information indicating that installation of the temperature-detecting unit51(51-1,51-2) or the flow channel-switching unit40(the first on/off-switching device41-1, the first on/off-switching device41-2, the second on/off-switching device42-1, or the second on/off-switching device42-2) is erroneous and notifies the outside of the erroneous installation. After the process of Step S104is performed, the erroneous installation-sensing unit62ends the erroneous installation-sensing process.

The erroneous installation-sensing unit62performs notification of the normal installation or the erroneous installation, for example, using a display unit of a remote controller, a display unit provided on a control board of the outdoor unit10, and a lamp provided on the control board as the notification output unit63. The erroneous installation-sensing unit62may output a notification indicating the normal installation or the erroneous installation to a mobile terminal or the like via the remote controller or the control board.

As described above, the air-conditioning device100according to this embodiment includes the main circuit RC, the flow channel-switching unit40, the bypass pipe37, the temperature-detecting unit51, the operation control unit61, and the erroneous installation-sensing unit62. In the main circuit RC, the compressor11, the indoor heat exchanger21, the decompressor (for example, the first decompressor13), and a plurality of parallel heat exchangers14connected in parallel to each other are connected by a pipe and a refrigerant circulates. The flow channel-switching unit40is connected to the plurality of parallel heat exchangers14and selects one parallel heat exchanger14(for example, the parallel heat exchanger14-2) out of the plurality of parallel heat exchangers14as a defrosting target which is a target of defrosting by melting frost attached to the parallel heat exchanger14. The bypass pipe37causes part of the refrigerant emitted from the compressor11to flow into the parallel heat exchanger14(for example, the parallel heat exchanger14-2) selected as a defrosting target by the flow channel-switching unit40. The temperature-detecting unit51detects the temperatures of the refrigerant in the plurality of parallel heat exchangers14. The operation control unit61operates the flow channel-switching unit40such that the operation is switched between the normal heating operation mode and the defrosting heating operation mode. Here, the normal heating operation mode is an operation mode in which the plurality of parallel heat exchangers14serve as evaporators. The defrosting heating operation mode is an operation mode in which one parallel heat exchanger14(for example, the parallel heat exchanger14-2) out of the plurality of parallel heat exchangers14is selected as a defrosting target, part of the refrigerant flows thereinto via the bypass pipe37, and the other parallel heat exchanger14(for example, the parallel heat exchanger14-1) out of the plurality of parallel heat exchangers14serves as an evaporator. The erroneous installation-sensing unit62senses erroneous installation of an installed component associated with defrosting (for example, the temperature-detecting unit51or the flow channel-switching unit40) based on the detected temperatures in the plurality of parallel heat exchangers14detected by the temperature-detecting unit51.

Accordingly, the air-conditioning device100according to this embodiment can sense erroneous installation of an installed component (for example, the temperature-detecting unit51or the flow channel-switching unit40) associated with defrosting and perform defrosting normally without stopping heating of the indoor unit20.

In this embodiment, the erroneous installation-sensing unit62senses that the flow channel-switching unit40or the temperature-detecting unit51is erroneously installed when the detected temperature (for example, the detected temperature T2) in the parallel heat exchanger14(for example, the parallel heat exchanger14-2) serving as a defrosting target is equal to or lower than the detected temperature (for example, equal to or lower than the detected temperature T1) in the parallel heat exchanger14(for example, the parallel heat exchanger14-1) serving as an evaporator in the state in which the operation mode is switched to the defrosting heating operation mode.

Accordingly, the air-conditioning device100according to this embodiment can appropriately sense that the flow channel-switching unit40or the temperature-detecting unit51is erroneously installed by comparing the detected temperature T2of the refrigerant in the parallel heat exchanger14-2serving as a defrosting target with the detected temperature T1of the refrigerant in the parallel heat exchanger14-1serving as an evaporator.

In this embodiment, the erroneous installation-sensing unit62causes the notification output unit63to output notification information based on the result of sensing of erroneous installation of an installed component when erroneous installation of the installed component is sensed.

Accordingly, with the air-conditioning device100according to this embodiment, when erroneous installation of the installed component is sensed, a user can recognize erroneous installation of an installed component or normal installation of an installed component.

In this embodiment, when the starting condition of the process of sensing erroneous installation of an installed component is satisfied, the erroneous installation-sensing unit62senses erroneous installation of an installed component in a state in which the operation mode is switched to the defrosting heating operation mode.

Accordingly, the air-conditioning device100according to this embodiment can ascertain erroneous installation of an installed component at a timing suitable for the starting condition.

Also, in the above describedFIG.8, the air-conditioning device100according to this embodiment can melt frost by causing a high-temperature high-pressure gas refrigerant to flow into the parallel heat exchanger14-2without decompressing the gas refrigerant even when the flow rate-adjusting device18is not provided. However, when a refrigerant with a high pressure and a high saturation temperature flows into the parallel heat exchanger14-2, the refrigerant condenses immediately due to a large temperature difference from the frost melting point (0° C.). Accordingly, since an amount of liquid refrigerant in the parallel heat exchanger14-2increases and an amount of refrigerant used for heating is insufficient, heating capability decreases.

Therefore, the air-conditioning device100according to this embodiment can lower the saturation temperature of the refrigerant and suppress an amount of liquid refrigerant in the parallel heat exchanger14-2by decompressing the refrigerant emitted from the compressor11and causing the refrigerant to flow into the parallel heat exchanger14-2using the flow rate-adjusting device18. Accordingly, with the air-conditioning device100according to this embodiment, it is possible to enhance indoor comfortability.

In the erroneous installation-sensing process illustrated in the above describedFIG.10, the outdoor fan19may operate or may not operate. By stopping the outdoor fan19, the refrigerant temperature in the parallel heat exchanger14serving as an evaporator is likely to decrease and the refrigerant temperature in the other heat exchanger is likely to increase. Accordingly, the air-conditioning device100according to this embodiment can easily sense a temperature difference between the detected temperature T1and the detected temperature T2by stopping the outdoor fan19.

Also, on the other hand, by causing the outdoor fan19to operate, evaporation of the refrigerant is promoted. Accordingly, with the air-conditioning device100according to this embodiment, it is possible to prevent intake of a liquid refrigerant into the compressor11by causing the outdoor fan19to operate.

In the erroneous installation-sensing process according to this embodiment, the first decompressor13or the third decompressor16may be turned on or may be turned off. For example, by turning off the first decompressor13or the third decompressor16, the refrigerant circuit on the indoor unit20side in the air-conditioning device100according to this embodiment is closed and a path in which a refrigerant flows decreases. Accordingly, since a difference between the emission pressure and the intake pressure of the compressor11increases and, by the increased difference, the temperature difference of the refrigerant between the parallel heat exchanger14serving as an evaporator and the other parallel heat exchanger14increases, the air-conditioning device100according to this embodiment can easily sense the temperature difference between the detected temperature T1and the detected temperature T2.

For example, by turning on the first decompressor13and the third decompressor16, the air-conditioning device100according to this embodiment can store an unnecessary refrigerant in the receiver15, and thus it is possible to prevent intake of a liquid refrigerant into the compressor11.

Also, in the above describedFIG.10, an example in which the parallel heat exchanger14-1serves as an evaporator, the parallel heat exchanger14-2is selected as a defrosting target, and the erroneous installation-sensing process is performed is described, but the parallel heat exchanger14-1may be selected as a defrosting target, the parallel heat exchanger14-2may serve as an evaporator, and the erroneous installation-sensing process may be performed. In this case, in Step S102inFIG.10, the determination condition is inverted, and normal installation is sensed when the detected temperature T1is higher than the detected temperature T2.

Second Embodiment

An air-conditioning device100aaccording to a second embodiment of the present disclosure are described below. In this embodiment, a modified example in which a plurality of outdoor fans19are provided and airflow volumes blown to a plurality of parallel heat exchangers14can be changed are described.

FIG.11is a drawing illustrating an example of a configuration of the air-conditioning device100aaccording to the second embodiment.

As illustrated inFIG.11, the air-conditioning device100aincludes an outdoor unit10a, an indoor unit20, and a control device60a.

InFIG.11, the same elements as inFIG.1are referred to by the same reference signs and description thereof are omitted. In the following description, differences of the air-conditioning device100afrom the configuration in the first embodiment are mainly described.

The outdoor unit10aincludes a compressor11, a cooling/heating-switching unit12, a first decompressor13, a plurality of parallel heat exchangers14(14-1and14-2), a receiver15, a third decompressor16, a plurality of second decompressors17(17-1and17-2), a flow rate-adjusting device18, a plurality of outdoor fans (19-1and19-2), a flow channel-switching unit40, and a plurality of temperature-detecting units51(51-1and51-2). The outdoor unit10ais different from the outdoor unit10according to the first embodiment in that the plurality of outdoor fans (19-1and19-2) corresponding to the plurality of parallel heat exchangers14(14-1and14-2) are provided.

The outdoor fan19-1is an air blower that blows air to the parallel heat exchanger14-1. The outdoor fan19-1sends outside air to the parallel heat exchanger14-1.

The outdoor fan19-2is an air blower that blows air to the parallel heat exchanger14-2. The outdoor fan19-2sends outside air to the parallel heat exchanger14-2.

The control device60aincludes, for example, a CPU and controls operations of various control units and switching of an operation mode. The control device60aincludes, for example, control boards installed in the outdoor unit10aand the indoor unit and a remote controller grounded indoors.

The control device60aincludes an operation control unit61a, an erroneous installation-sensing unit62a, and a notification output unit63.

The basic function of the operation control unit61ais the same as the operation control unit61according to the first embodiment. The operation control unit61ais different from the operation control unit61according to the first embodiment in that control of two outdoor fans (19-1and19-2) is performed.

The operation control unit61acontrols the two outdoor fans (19-1and19-2) such that an airflow volume for the parallel heat exchanger14serving as a defrosting target is smaller than an airflow volume for the parallel heat exchanger14serving as an evaporator in the defrosting heating operation mode. The operation control unit61aimproves defrosting performance by individually controlling the outdoor fan19-1and the outdoor fan19-2in the defrosting heating operation mode.

For example, when the parallel heat exchanger14-2is a defrosting target, the operation control unit61acontrols the outdoor fan19-1and the outdoor fan19-2such that the airflow volume for the parallel heat exchanger14-2is smaller than the airflow volume for the parallel heat exchanger14-1. In this case, the operation control unit61adecreases the airflow volume for the parallel heat exchanger14-2by stopping the outdoor fan19-2or controls the outdoor fan19-2at a rotation speed lower than that of the outdoor fan19-1. In this case, the operation control unit61aperforms control such that the outdoor fan19-1operates.

When the erroneous installation-sensing process is performed, the operation control unit61adoes not change the airflow volume of the outdoor fan19-1corresponding to the parallel heat exchanger14-1serving as an evaporator and increases the airflow volume of the outdoor fan19-2corresponding to the parallel heat exchanger14-2serving as a defrosting target.

The basic function of the erroneous installation-sensing unit62ais the same as the erroneous installation-sensing unit62according to the first embodiment. The erroneous installation-sensing unit62asenses erroneous installation of a plurality of outdoor fans (19-1and19-2), for example, based on change of the detected temperature before and after the airflow volume of the outdoor fan19-1(or the outdoor fan19-2) for one of the parallel heat exchanger14-2serving as a defrosting target and the parallel heat exchanger14-1serving as an evaporator is changed.

For example, the erroneous installation-sensing unit62achanges the outdoor fan19-2from stopping to operating and senses that the outdoor fan (19-1,19-2) is erroneously installed when the detected temperature after the airflow volume for the parallel heat exchanger14-2serving as a defrosting target is increased is not lower than the detected temperature before the airflow volume is increased (not lower than the previous detected temperature). The erroneous installation-sensing unit62asenses that the outdoor fan (19-1,19-2) is installed normally when the detected temperature after the airflow volume for the parallel heat exchanger14-2serving as a defrosting target is increased is lower than the detected temperature before the airflow volume is increased.

Operations of the air-conditioning device100aaccording to this embodiment are described below with reference to the drawings.

FIG.12is a flowchart illustrating an example of the erroneous installation-sensing process in the air-conditioning device100aaccording to this embodiment.

The air-conditioning device100aperforms the erroneous installation-sensing process illustrated inFIG.12when a starting condition of the erroneous installation-sensing process is satisfied.

As illustrated inFIG.12, the operation control unit61aof the control device60afirst performs the defrosting heating operation in which the parallel heat exchanger14-2is selected as a defrosting target (Step S201). That is, the operation control unit61asets the cooling/heating-switching unit12to switching B, sets the first on/off-switching device41-1and the second on/off-switching device42-2to the ON state, and sets the first on/off-switching device41-2and the second on/off-switching device42-1to the OFF state. The operation control unit61aturns on the flow rate-adjusting device18to start the operation of the compressor11. The operation control unit61asets the outdoor fan19-1to the ON state (an operating state) and sets the outdoor fan19-2to the OFF state (a stopped state).

Then, the erroneous installation-sensing unit62aof the control device60adetermines whether the detected temperature T2is higher than the detected temperature T1(Step S202). The erroneous installation-sensing unit62adetermines whether the detected temperature T2in the parallel heat exchanger14-2is higher than the detected temperature T1in the parallel heat exchanger14-1. When the detected temperature T2is higher than the detected temperature T1(Step S202: YES), the erroneous installation-sensing unit62acauses the process to proceed to Step S203. When the detected temperature T2is equal to or lower than the detected temperature T1(Step S202: NO), the erroneous installation-sensing unit62acauses the process to proceed to Step S207.

In Step S203, the operation control unit61aoperates the outdoor fan19-2. That is, the operation control unit61asets the outdoor fan19-2to the ON state (the operating state).

Then, the erroneous installation-sensing unit62adetermines that a detected temperature T2′ is lower than the detected temperature T2(Step S204). Here, the detected temperature T2is a detected temperature of a refrigerant detected by the temperature-detecting unit51-2before the outdoor fan19-2is switched to the ON state (when the outdoor fan19-2is in the OFF state). The detected temperature T2′ is a detected temperature of the refrigerant detected by the temperature-detecting unit51-2after the outdoor fan19-2is switched to the ON state. The erroneous installation-sensing unit62acompares the detected temperature T2and the detected temperature T2′ and causes the process to proceed to Step S205when the detected temperature T2′ is lower than the detected temperature T2(Step S204: YES). When the detected temperature T2′ is equal to or higher than the detected temperature T2(Step S204: NO), the erroneous installation-sensing unit62acauses the process to proceed to Step S206.

In Step S205, the erroneous installation-sensing unit62anotifies the outside of normal installation. In this case, the erroneous installation-sensing unit62acauses the notification output unit63to output notification information indicating that installation of the temperature-detecting unit51(51-1,51-2), the flow channel-switching unit40(the first on/off-switching device41-1, first on/off-switching device41-2, the second on/off-switching device42-1, and the second on/off-switching device42-1), and the outdoor fan (19-1,19-2) is normal and notifies the outside of normal installation. After the process of Step S205is performed, the erroneous installation-sensing unit62aends the erroneous installation-sensing process.

In Step S206, the erroneous installation-sensing unit62anotifies the outside of erroneous installation of the outdoor fan (19-1,19-2). In this case, the erroneous installation-sensing unit62acauses the notification output unit63to output notification information indicating that installation of the outdoor fan (19-1,19-2) is erroneous and notifies the outside of erroneous installation of the outdoor fan (19-1,19-2). After the process of Step S206is performed, the erroneous installation-sensing unit62aends the erroneous installation-sensing process.

In Step S207, the erroneous installation-sensing unit62anotifies the outside of erroneous installation of the temperature-detecting unit51or the flow channel-switching unit40. In this case, the erroneous installation-sensing unit62acauses the notification output unit63to output notification information indicating that installation of the temperature-detecting unit51or the flow channel-switching unit40is erroneous and notifies the outside of erroneous installation. After the process of Step S207is performed, the erroneous installation-sensing unit62aends the erroneous installation-sensing process.

In the aforementioned process flow, when the outdoor fan19-1and the outdoor fan19-2are installed normally, the airflow volume for the parallel heat exchanger14-2increases and cooling performance of the refrigerant using air is improved by switching the outdoor fan19-2to the ON state, and the temperature detected by the temperature-detecting unit51-2decreases. Accordingly, the erroneous installation-sensing unit62aswitches the outdoor fan19-2from the OFF state to the ON state and determines that the outdoor fan19-1and the outdoor fan19-2are installed normally when the detected temperature T2′ after the outdoor fan19-2is switched to the ON state is lower than the detected temperature T2before the outdoor fan19-2is switched to the ON state (when the outdoor fan19-2is in the OFF state).

In the process of Step S204inFIG.12, the erroneous installation-sensing unit62adetermines whether the outdoor fan19-1and the outdoor fan19-2are installed normally by comparing the detected temperature T2and the detected temperature T2′ detected by the temperature-detecting unit51-2, but the temperature detected by the temperature-detecting unit51-1may be used.

FIG.13is a drawing schematically illustrating change of a detected temperature with time in the erroneous installation-sensing process according to this embodiment.

InFIG.13, the vertical axis represents the detected temperature, and the horizontal axis represents the time. In a waveform W1and a waveform W3, for example, change of the detected temperature in normal installation when the outdoor fan19-2is switched from the OFF state to the ON state at time t1is indicated by a solid line. In a waveform W2and a waveform W4, change of the detected temperature in erroneous installation when the outdoor fan (19-1,19-2) is erroneously installed is indicated by a dashed line.

In the case of normal installation, since the temperature detected by the temperature-detecting unit51-2connected to the parallel heat exchanger14-2corresponding to the outdoor fan19-2changes, the detected temperature T2′ is lower than the detected temperature T2(see the waveform W1). At this time, the temperature detected by the temperature-detecting unit51-1does not change and the detected temperature T1′ detected by the temperature-detecting unit51-2after the outdoor fan19-2is switched to the ON state does not change from the detected temperature T1(see the waveform W3).

On the other hand, when the outdoor fan19-1and the outdoor fan19-2are erroneously installed, the outdoor fan19-2corresponds to the parallel heat exchanger14-1and thus the temperature detected by the temperature-detecting unit51-1changes. In this case, since the airflow volume for the parallel heat exchanger14-1serving as an evaporator increases and heating performance of the refrigerant using air is improved, the temperature detected by the temperature-detecting unit51-1increases and the detected temperature T1′ is higher than the detected temperature T1(see the waveform W4).

Accordingly, in the process of Step S204illustrated inFIG.12, the erroneous installation-sensing unit62amay sense that the outdoor fan (19-1,19-2) is erroneously installed when the detected temperature T1′ is higher than the detected temperature T1.

The outdoor fan19-2is switched to the OFF state in the process of Step S201and is switched to the ON state in the process of Step S203, but the outdoor fan19-2may be made to operate at a lower rotation speed in the process of Step S201and the rotation speed of the outdoor fan19-2may be increased in the process of Step S203.

In the process of Step S203, the rotation speed of the outdoor fan19-1may be decreased instead of switching of the outdoor fan19-2to the ON state or increasing the rotation speed thereof. In this case, in the process of Step S204, the erroneous installation-sensing unit62adetermines normal installation when the detected temperature T1′ is lower than the detected temperature T1or determines erroneous installation when the detected temperature T2′ is higher than the detected temperature T2.

As described above, the air-conditioning device100aaccording to this embodiment includes a plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) that blow air to a plurality of parallel heat exchangers14. The erroneous installation-sensing unit62asenses erroneous installation of a plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) based on a change of the detected temperature before and after the airflow volume of the air blower (the outdoor fan19-1or the outdoor fan19-2) for one of the parallel heat exchanger14serving as a defrosting target and the parallel heat exchanger14serving as an evaporator is changed.

Accordingly, the air-conditioning device100aaccording to this embodiment can appropriately sense erroneous installation of a plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2).

In this embodiment, the operation control unit61adoes not change the airflow volume of the air blower (the outdoor fan19-1) corresponding to the parallel heat exchanger14(for example, the parallel heat exchanger14-1) serving as an evaporator but increases the airflow volume of the air blower (the outdoor fan19-2) corresponding to the parallel heat exchanger14(for example, the parallel heat exchanger14-2) serving as a defrosting target. The erroneous installation-sensing unit62asenses that the plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) are erroneously installed when the detected temperature T2′ after the airflow volume for the parallel heat exchanger14serving as a defrosting target (for example, the parallel heat exchanger14-2) is increased is not lower than the detected temperature T2before the airflow volume is increased.

Accordingly, the air-conditioning device100aaccording to this embodiment can appropriately sense erroneous installation of the plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) by increasing the airflow volume of the air blower (the outdoor fan19-2) corresponding to the parallel heat exchanger14serving as a defrosting target (for example, the parallel heat exchanger14-2).

In this embodiment, the operation control unit61adoes not change the airflow volume of the air blower (the outdoor fan19-1) corresponding to the parallel heat exchanger14serving as an evaporator (for example, the parallel heat exchanger14-1) but increases the airflow volume of the air blower (the outdoor fan19-2) corresponding to the parallel heat exchanger14serving as a defrosting target (for example, the parallel heat exchanger14-2). The erroneous installation-sensing unit62asenses that the plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) are erroneously installed when the detected temperature T1′ after the airflow volume for the parallel heat exchanger14serving as a defrosting target (for example, the parallel heat exchanger14-2) is increased is higher than the detected temperature T1before the airflow volume is increased.

Accordingly, the air-conditioning device100aaccording to this embodiment can appropriately sense erroneous installation of the plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) by increasing the airflow volume of the air blower (the outdoor fan19-2) corresponding to the parallel heat exchanger14serving as a defrosting target (for example, the parallel heat exchanger14-2).

In this embodiment, the operation control unit61acontrols the plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) such that the airflow volume for the parallel heat exchanger14serving as a defrosting target (for example, the parallel heat exchanger14-2) is smaller than the airflow volume for the parallel heat exchanger14serving as an evaporator (for example, the parallel heat exchanger14-1) in the defrosting heating operation mode.

Accordingly, with the air-conditioning device100aaccording to this embodiment, since the airflow volume for the parallel heat exchanger14serving as a defrosting target (for example, the parallel heat exchanger14-2) decreases, it is possible to suppress dissipation of heat from a high-temperature refrigerant used for defrosting to air and to efficiently transmit heat of the refrigerant to frost. Accordingly, with the air-conditioning device100aaccording to this embodiment, it is possible to improve defrosting performance by individually operating the outdoor fan19-1and the outdoor fan19-2in the defrosting heating operation mode.

Third Embodiment

An air-conditioning device100baccording to a third embodiment of the present disclosure are described below with reference to the drawings.

FIG.14is a drawing illustrating an example of a configuration of the air-conditioning device100baccording to the third embodiment.

As illustrated inFIG.14, the air-conditioning device100bincludes an outdoor unit10b, an indoor unit20, and a control device60b.

InFIG.14, the same elements as inFIG.1orFIG.11are referred to by the same reference signs and description thereof are omitted. In the following description, differences of the air-conditioning device100bfrom the first embodiment and the second embodiment are mainly described.

The outdoor unit10bincludes a compressor11, a cooling/heating-switching unit12, a first decompressor13, a plurality of parallel heat exchangers14(14-1and14-2), a receiver15, a third decompressor16, a plurality of second decompressors17(17-1and17-2), a flow rate-adjusting device18, a plurality of outdoor fans (19-1and19-2), a flow channel-switching unit40a, a plurality of temperature-detecting units51(51-1and51-2), and a plurality of temperature-detecting units52(52-1and52-2). The outdoor unit10bis different from the outdoor unit10aaccording to the second embodiment in that the flow channel-switching unit40ahas a different configuration and the plurality of temperature-detecting units52(52-1and52-2) are provided.

In this embodiment, the temperature-detecting unit51-1and the temperature-detecting unit52-1are used as temperature-detecting units50-1that detect the temperature of a refrigerant in the parallel heat exchanger14-1, and the temperature-detecting unit51-2and the temperature-detecting unit52-2are used as temperature-detecting units50-2that detect the temperature of a refrigerant in the parallel heat exchanger14-2.

In this embodiment, each of the temperature-detecting unit51-1and the temperature-detecting unit51-2is an example of a first temperature-detecting unit, and each of the temperature-detecting unit52-1and the temperature-detecting unit52-2is an example of a second temperature-detecting unit. The temperature-detecting unit51-1and the temperature-detecting unit51-2are referred to as temperature-detecting units51when they represent arbitrary first temperature-detecting units provided in the air-conditioning device100bor when they are not particularly distinguished.

The temperature-detecting unit52-1and the temperature-detecting unit52-2are referred to as temperature-detecting units52when they represent arbitrary second temperature-detecting units provided in the air-conditioning device100bor when they are not particularly distinguished. The temperature-detecting unit50-1and the temperature-detecting unit50-2are referred to as temperature-detecting units50when they represent arbitrary temperature-detecting units provided in the air-conditioning device100bor when they are not particularly distinguished.

The temperature-detecting unit51detects the saturation temperature of the refrigerant in the parallel heat exchanger14as the first detected temperature. That is, the temperature-detecting unit51-1detects the saturation temperature of the refrigerant in the parallel heat exchanger14-1as a detected temperature T11. The temperature-detecting unit51-2detects the saturation temperature of the refrigerant in the parallel heat exchanger14-2as a detected temperature T12.

The temperature-detecting unit52is disposed in a pipe (the first connection pipe34) connected to the opposite side of the bypass pipe37with respect to the parallel heat exchanger14and detects the temperature of the refrigerant at an outlet of the parallel heat exchanger14serving as a defrosting target as the second detected temperature. That is, the temperature-detecting unit52-1detects the temperature of the refrigerant in a part of the parallel heat exchanger14-1corresponding to the first connection pipe34-1as a detected temperature T21. The temperature-detecting unit52-2detects the temperature of the refrigerant in a part of the parallel heat exchanger14-2corresponding to the first connection pipe34-2as a detected temperature T22. As long as the temperature of the refrigerant at an outlet when the parallel heat exchanger14is selected as a defrosting target can be detected, the temperature-detecting unit52is not limited to be disposed in the first connection pipe34and may be disposed in the vicinity of the outlet of the parallel heat exchanger14.

The flow channel-switching unit40ais connected to two parallel heat exchangers14and selects one parallel heat exchanger14of the two parallel heat exchangers14as a defrosting target. The flow channel-switching unit40ais disposed in the second connection pipe35(35-1,35-2) between the emission side (the cooling/heating-switching unit12side) of the compressor11and the two parallel heat exchangers14(14-1and14-2).

The flow channel-switching unit40aincludes a switching device43-1and a switching device43-2.

The switching device43-1is, for example, a three-way valve or a four-way valve. The switching device43-1switches a pipe connected to the parallel heat exchanger14-1between the intake pipe36and the bypass pipe37.

The switching device43-2is, for example, a three-way valve or a four-way valve. The switching device43-2switches a pipe connected to the parallel heat exchanger14-2between the intake pipe36and the bypass pipe37.

In this embodiment, the switching device43-1and the switching device43-2are referred to as switching devices43when they are arbitrary switching devices provided in the air-conditioning device100bor when they are not particularly distinguished.

The control device60bincludes, for example, a CPU and controls operations of various control units and switching of an operation mode. The control device60bincludes, for example, control boards installed in the outdoor unit10band the indoor unit20and a remote controller grounded indoors.

The control device60bincludes an operation control unit61b, an erroneous installation-sensing unit62b, and a notification output unit63.

The basic function of the operation control unit61bis the same as the operation control unit61aaccording to the second embodiment. The operation control unit61bswitches the operation mode between the normal heating operation mode and the defrosting heating operation mode by operating the flow channel-switching unit40a. The operation control unit61bswitches a pipe to be connected to the parallel heat exchanger14-1between the intake pipe36and the bypass pipe37by operating the switching device43-1. The operation control unit61bswitches a pipe to be connected to the parallel heat exchanger14-2between the intake pipe36and the bypass pipe37by operating the switching device43-2.

States of the cooling/heating-switching unit12and the flow channel-switching unit40acorresponding to the operation modes of the air-conditioning device100bare described below with reference toFIG.15.

FIG.15is a drawing illustrating states of the cooling/heating-switching unit12and the flow channel-switching unit40acorresponding to the operation modes of the air-conditioning device100baccording to this embodiment.

InFIG.15, in the switching device43-1and the switching device43-2of the flow channel-switching unit40a, “main circuit” state represents a state in which the parallel heat exchanger14is connected to the intake pipe36, and “bypass” state represents a state in which the parallel heat exchanger14is connected to the bypass pipe37.

For example, when the operation is the cooling operation mode, the operation control unit61bsets the cooling/heating-switching unit12to “switching A” and sets the switching device43-1and the switching device43-2to “main circuit” state.

For example, when the operation mode is the normal heating operation mode, the operation control unit61bsets the cooling/heating-switching unit12to “switching B” and sets the switching device43-1and the switching device43-2to “main circuit” state.

For example, when the operation mode is the defrosting heating operation mode and the path 1 side is selected as a defrosting target (in the case of “path 1-side defrosting”), the operation control unit61bsets the cooling/heating-switching unit12to “switching B.” In this case, the operation control unit61bsets the switching device43-1to “bypass” and sets the switching device43-2to “main circuit” state.

For example, when the operation mode is the defrosting heating operation mode and the path 2 side is selected as a defrosting target (in the case of “path 2-side defrosting”), the operation control unit61bsets the cooling/heating-switching unit12to “switching B.” In this case, the operation control unit61bsets the switching device43-1to “main circuit” state and sets the switching device43-2to “bypass” state.

The basic function of the erroneous installation-sensing unit62bis the same as the erroneous installation-sensing unit62aaccording to the second embodiment. The erroneous installation-sensing unit62bsenses erroneous installation of an installed component associated with defrosting. In this embodiment, examples of the installed component associated with defrosting include the flow channel-switching unit40a, the temperature-detecting unit51, the temperature-detecting unit52, and the outdoor fan (19-1,19-2).

The erroneous installation-sensing unit62bdetermines whether one of the flow channel-switching unit40a, the temperature-detecting unit51, the temperature-detecting unit52, and the outdoor fan (19-1,19-2) is erroneously installed, for example, based on a combination of four detected temperatures including the detected temperature T12and the detected temperature T22in the parallel heat exchanger14-2serving as a defrosting target and the detected temperature T11and the detected temperature T21in the parallel heat exchanger14-1serving as an evaporator.

Operations of the air-conditioning device100baccording to this embodiment are described below with reference to the drawings.

FIG.16is a flowchart illustrating an example of the erroneous installation-sensing process in the air-conditioning device100baccording to this embodiment.

The air-conditioning device100bperforms the erroneous installation-sensing process illustrated inFIG.16when a starting condition of the erroneous installation-sensing process is satisfied.

As illustrated inFIG.16, the operation control unit61bof the control device60bfirst performs the defrosting heating operation in which the parallel heat exchanger14-2is selected as a defrosting target (Step S301). That is, as illustrated inFIG.15, the operation control unit61bsets the cooling/heating-switching unit12to “switching B,” sets the switching device43-1to “main circuit” state, and sets the switching device43-2to “bypass” state. The operation control unit61bturns on the flow rate-adjusting device18to start the operation of the compressor11. The operation control unit61bsets the outdoor fan19-1to the ON state (an operating state) and sets the outdoor fan19-2to the OFF state (a stopped state).

Then, the erroneous installation-sensing unit62bof the control device60bdetermines whether the detected temperature T12is higher than the detected temperature T11(Step S302). The erroneous installation-sensing unit62bdetermines whether the detected temperature T12detected by the temperature-detecting unit51-2is higher than the detected temperature T11detected by the temperature-detecting unit51-1. When the detected temperature T12is higher than the detected temperature T11(Step S302: YES), the erroneous installation-sensing unit62bcauses the process to proceed to Step S303. When the detected temperature T12is equal to or lower than the detected temperature T11(Step S302: NO), the erroneous installation-sensing unit62bcauses the process to proceed to Step S308.

In Step S303, the erroneous installation-sensing unit62bdetermines whether the detected temperature T22is higher than the detected temperature T21. The erroneous installation-sensing unit62bdetermines whether the detected temperature T22detected by the temperature-detecting unit52-2is higher than the detected temperature T21detected by the temperature-detecting unit52-1. When the detected temperature T22is higher than the detected temperature T21(Step S303: YES), the erroneous installation-sensing unit62bcauses the process to proceed to Step S304. When the detected temperature T22is equal to or lower than the detected temperature T21(Step S303: NO), the erroneous installation-sensing unit62bcauses the process to proceed to Step S307.

In Step S304, the erroneous installation-sensing unit62bdetermines whether the detected temperature T12is higher than the detected temperature T22. The erroneous installation-sensing unit62bdetermines whether the detected temperature T12detected by the temperature-detecting unit51-2is higher than the detected temperature T22detected by the temperature-detecting unit52-2. When the detected temperature T12is higher than the detected temperature T22(Step S304: YES), the erroneous installation-sensing unit62bcauses the process to proceed to Step S305. When the detected temperature T12is equal to or lower than the detected temperature T22(Step S304: NO), the erroneous installation-sensing unit62bcauses the process to proceed to Step S306.

In Step S305, the erroneous installation-sensing unit62bnotifies the outside that the outdoor fans (19-1and19-2) are erroneously installed. In this case, the erroneous installation-sensing unit62bcauses the notification output unit63to output notification information indicating that installation of the outdoor fans (19-1,19-2) is erroneous and notifies the outside that the outdoor fans (19-1,19-2) are erroneously installed. After the process of Step S305is performed, the erroneous installation-sensing unit62bends the erroneous installation-sensing process.

In Step S306, the erroneous installation-sensing unit62bnotifies the outside of normal installation. In this case, the erroneous installation-sensing unit62bcauses the notification output unit63to output notification information indicating that installation of the flow channel-switching unit40a, the temperature-detecting unit51, the temperature-detecting unit52, and the outdoor fans (19-1,19-2) is normal and notifies the outside of normal installation. After the process of Step S306is performed, the erroneous installation-sensing unit62bends the erroneous installation-sensing process.

In Step S307, the erroneous installation-sensing unit62bnotifies the outside that the temperature-detecting unit51is erroneously installed. In this case, the erroneous installation-sensing unit62bcauses the notification output unit63to output notification information indicating that installation of the temperature-detecting units51(51-1and51-2) is erroneous and notifies the outside that the temperature-detecting units51(51-1and51-2) are erroneously installed. After the process of Step S307is performed, the erroneous installation-sensing unit62bends the erroneous installation-sensing process.

In Step S308, the erroneous installation-sensing unit62bdetermines whether the detected temperature T22is higher than the detected temperature T21. The erroneous installation-sensing unit62bdetermines whether the detected temperature T22detected by the temperature-detecting unit52-2is higher than the detected temperature T21detected by the temperature-detecting unit52-1. When the detected temperature T22is higher than the detected temperature T21(Step S308: YES), the erroneous installation-sensing unit62bcauses the process to proceed to Step S309. When the detected temperature T22is equal to or lower than the detected temperature T21(Step S308: NO), the erroneous installation-sensing unit62bcauses the process to proceed to Step S310.

In Step S309, the erroneous installation-sensing unit62bnotifies the outside that the temperature-detecting unit52is erroneously installed. In this case, the erroneous installation-sensing unit62bcauses the notification output unit63to output notification information indicating that installation of the temperature-detecting units52(52-1and52-2) is erroneous and notifies the outside that the temperature-detecting units52(52-1and52-2) are erroneously installed. After the process of Step S309is performed, the erroneous installation-sensing unit62bends the erroneous installation-sensing process.

In Step S310, the erroneous installation-sensing unit62bnotifies the outside that the flow channel-switching unit40ais erroneously installed. In this case, the erroneous installation-sensing unit62bcauses the notification output unit63to output notification information indicating that installation of the flow channel-switching unit40a(the switching device43-1and the switching device43-2) is erroneous and notifies the outside that the flow channel-switching unit40a(the switching device43-1and the switching device43-2) is erroneously installed. After the process of Step S310is performed, the erroneous installation-sensing unit62bends the erroneous installation-sensing process.

The determination of erroneous installation in Steps S302to S304are described below in detail.

First, when the flow channel-switching unit40a(the switching device43-1and the switching device43-2), the temperature-detecting units51(51-1and51-2), and the temperature-detecting units52(52-1and52-2) are installed normally, the temperature-detecting unit51-1and the temperature-detecting unit52-1detect the temperature of the parallel heat exchanger14-1serving as an evaporator and thus the detected temperature T11and the detected temperature T21are low.

The temperature-detecting unit52-1and the temperature-detecting unit52-2detect the temperature of the parallel heat exchanger14-2into which emitted gas flows, and thus the detected temperature T21and the detected temperature T22are high. From this point of view, the erroneous installation-sensing unit62bcan ascertain that the flow channel-switching unit40aand the temperature-detecting units51are installed normally because the detected temperature T12is higher than the detected temperature T11in Step S302. The erroneous installation-sensing unit62bcan ascertain that the temperature-detecting units52are installed normally because the detected temperature T22is higher than the detected temperature T21in Step S303.

When it is determined in Step S303that the detected temperature T22is equal to or lower than the detected temperature T21, the erroneous installation-sensing unit62bcan determine that the detected temperature T22is the temperature in the parallel heat exchanger14-1serving as an evaporator and ascertain that the temperature-detecting units52are erroneously installed.

When the outdoor fan19-1and the outdoor fan19-2are installed normally, the emitted gas flowing into the parallel heat exchanger14-2is cooled with air, but the outdoor fan19-2corresponding to the parallel heat exchanger14-2is in the OFF state, and thus the cooling performance is low and supercooling is not reached. Accordingly, the detected temperature T22is the same saturation temperature as the detected temperature T12.

When the outdoor fan19-1and the outdoor fan19-2are erroneously installed, the outdoor fan19-1corresponding to the parallel heat exchanger14-2is in the ON state, and thus the cooling performance is improved and supercooling is reached. Accordingly, the detected temperature T22is detected as the supercooling temperature, and thus the detected temperature T22is lower than the detected temperature T12, which is detected as the saturation temperature. Accordingly, the erroneous installation-sensing unit62bcan sense erroneous installation of the outdoor fan19-1and the outdoor fan19-2by comparing the detected temperature T12and the detected temperature T22in Step S304.

When the erroneous installation-sensing unit62bdetermines in Step S302that the detected temperature T12is equal to or lower than the detected temperature T11, it means that any of the switching device43-1and the switching device43-2and the temperature-detecting unit51-1and the temperature-detecting unit51-2is erroneously installed. Accordingly, the erroneous installation-sensing unit62bcan compare the detected temperature T21and the detected temperature T22in Step S308and sense that the temperature-detecting units51(51-1and51-2) are erroneously installed when the detected temperature T22is higher than the detected temperature T21.

When it is determined in Step S310that the detected temperature T22is equal to or lower than the detected temperature T21, the erroneous installation-sensing unit62bcan sense that the flow channel-switching unit40a(the switching device43-1and the switching device43-2) are erroneously installed.

When the temperature-detecting units51(51-1and51-2) are erroneously installed, the parallel heat exchanger14-1serves as an evaporator and the emitted gas flows into the parallel heat exchanger14-2. Accordingly, the temperature-detecting unit51-2connected to the parallel heat exchanger14-1detects a low temperature and the temperature-detecting unit51-1connected to the parallel heat exchanger14-2detects a high temperature.

When the temperature-detecting units52(52-1and52-2) are installed normally, the temperature-detecting unit52-1connected to the parallel heat exchanger14-1detects a low temperature and the temperature-detecting unit52-2connected to the parallel heat exchanger14-2detects a high temperature. Accordingly, since it is determined in Step S302that the detected temperature T12is equal to or lower than the detected temperature T11and it is determined in Step S308that the detected temperature T22is higher than the detected temperature T21, the erroneous installation-sensing unit62bcan sense erroneous installation of the temperature-detecting units51(51-1and51-2).

When the flow channel-switching unit40a(the switching device43-1and the switching device43-2) is erroneously installed, the emitted gas flows into the parallel heat exchanger14-1and the parallel heat exchanger14-2serves as an evaporator. Accordingly, the temperature-detecting unit51-1and the temperature-detecting unit52-1connected to the parallel heat exchanger14-1detect a high temperature and the temperature-detecting unit51-2and the temperature-detecting unit52-2connected to the parallel heat exchanger14-2detect a low temperature.

Accordingly, since it is determined in Step S302that the detected temperature T12is equal to or lower than the detected temperature T11and it is determined in Step S308that the detected temperature T22is equal to or lower than the detected temperature T21, the erroneous installation-sensing unit62bcan sense erroneous installation of the flow channel-switching unit40a(the switching device43-1and the switching device43-2).

As described above, the air-conditioning device100baccording to this embodiment includes the temperature-detecting unit50configured to detect the temperatures of the refrigerants in a plurality of parallel heat exchangers14, the operation control unit61b, and the erroneous installation-sensing unit62b. The temperature-detecting unit50includes the temperature-detecting unit51(the first temperature-detecting unit) and the temperature-detecting unit52(the second temperature-detecting unit). The temperature-detecting unit51detects the saturation temperature of the refrigerant in each of the parallel heat exchangers14as the first detected temperature. The temperature-detecting unit52is disposed in the pipe connected to the opposite side to the bypass pipe37of each of the parallel heat exchangers14and detects the temperature of the refrigerant at the outlet of the parallel heat exchanger14serving as a defrosting target as the second detected temperature. The erroneous installation-sensing unit62bdetermines whether one of the flow channel-switching unit40, the temperature-detecting unit51, the temperature-detecting unit52, and the plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) is erroneously installed, based on a combination of four detected temperatures including the first detected temperature and the second detected temperature in the parallel heat exchanger14serving as a defrosting target and the first detected temperature and the second detected temperature in the parallel heat exchanger14serving as an evaporator. That is, the erroneous installation-sensing unit62bdetermines whether one of the flow channel-switching unit40, the temperature-detecting unit51, the temperature-detecting unit52, and the plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) is erroneously installed, for example, based on a combination of the detected temperature T21and the detected temperature T22in the parallel heat exchanger14-2serving as a defrosting target and the detected temperature T11and the detected temperature T12in the parallel heat exchanger14-1serving as an evaporator.

Accordingly, the air-conditioning device100baccording to this embodiment can appropriately sense whether one of the flow channel-switching unit40, the temperature-detecting unit51, the temperature-detecting unit52, and the plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) is erroneously installed. Accordingly, the air-conditioning device100baccording to this embodiment can appropriately sense erroneous installation of an installed component associated with defrosting and perform defrosting normally without stopping heating of the indoor unit20.

The present disclosure is not limited to the above described embodiments, and can be modified without departing from the scope of the present disclosure.

For example, in the aforementioned embodiments, the refrigerant used in the main circuit RC is a Freon refrigerant or an HFO refrigerant, but the present disclosure is not limited thereto. The refrigerant used in the main circuit RC may be, for example, a CO2refrigerant, an HC refrigerant (for example, a propane refrigerant or an isobutene refrigerant), an ammonia refrigerant, or a mixed refrigerant thereof. The refrigerant used in the main circuit RC may be a refrigerant used for a vapor compression type heat pump.

In the aforementioned embodiments, an example in which one indoor unit20is connected to one outdoor unit10(10a,10b) in the air-conditioning device100(100a,100b) is described, but the present disclosure is not limited thereto. The air-conditioning device100(100a,100b) may have, for example, a configuration in which two or more indoor units20are connected in parallel or a configuration in which two or more outdoor units10(10a,10b) are connected in parallel. When two or more indoor units20are provided, the air-conditioning device100(100a,100b) may have a refrigerant circuit configuration that can perform a cooling/heating simultaneous operation in which each indoor unit can selectively performs cooling or heating, by connecting three extension pipes in parallel or providing a switching device on the indoor unit20side.

In the aforementioned embodiments, an example in which the air-conditioning device100(100a,100b) includes the receiver15and the third decompressor16is described, but a configuration in which the receiver15and the third decompressor16are not provided may be employed. An example in which the outdoor unit10(10a,10b) includes the first decompressor13is described above, but the present disclosure is not limited thereto and the first decompressor13may be disposed outside of the outdoor unit10(10a,10b). For example, the first decompressor13may be disposed in a pipe connected to the second extension pipe33of the indoor unit20.

In the aforementioned embodiments, the parallel heat exchangers14(14-1and14-2) are not limited to the structure illustrated inFIG.2, and may have another structure. For example, the parallel heat exchanger14-1and the parallel heat exchanger14-2may include a mechanism for reducing heat leakage provided in the fin14b(for example, a notch or a slit provided in a fin), or a heat transfer tube for allowing a high-temperature refrigerant to flow may be provided between the parallel heat exchanger14-1and the parallel heat exchanger14-2. By splitting the fin14bor providing a mechanism for reducing heat leakage in the parallel heat exchanger14-1and the parallel heat exchanger14-2and providing a heat transfer tube for allowing a high-temperature refrigerant to flow, it is possible to suppress leakage of heat from the parallel heat exchanger14serving as a defrosting target to the parallel heat exchanger14serving as an evaporator and to suppress difficulty in defrosting at the boundary of the split due to leakage of heat.

In the aforementioned embodiments, an example in which the outdoor unit10(10a,10b) includes two parallel heat exchangers14is described, but three or more parallel heat exchangers14may be provided.

In the aforementioned embodiments, an example in which the outdoor unit10(10a,10b) includes the flow rate-adjusting device18is described, but a configuration in which the flow rate-adjusting device18is not provided may be employed. When the flow rate-adjusting device18is not provided, the second on/off-switching device42-1and the second on/off-switching device42-2of the flow channel-switching unit40or the switching device43-1and the switching device43-2of the flow channel-switching unit40amay have the function of the flow rate-adjusting device18.

In the above described third embodiment, an example in which the air-conditioning device100bappropriately senses that one of the flow channel-switching unit40, the temperature-detecting unit51, the temperature-detecting unit52, and a plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) is erroneously installed is described above, but the present disclosure is not limited thereto. The air-conditioning device100bmay be able to sense that two or more of the flow channel-switching unit40, the temperature-detecting unit51, the temperature-detecting unit52, and a plurality of air blowers (the outdoor fan19-1and the outdoor fan19-2) are erroneously installed or to sense the temperature-detecting unit51and the temperature-detecting unit52are erroneously installed using a combination of four temperatures including the detected temperature T11, the detected temperature T12, the detected temperature T21, and the detected temperature T22or magnitude relationships of temperature differences therebetween.

In the third embodiment, an example in which the air-conditioning device100(100a,100b) switches between the cooling operation and the heating operation is described above, but the present disclosure is not limited thereto. The air-conditioning device100(100a,100b) may have a circuit configuration for enabling a cooling/heating simultaneous operation, or the cooling/heating-switching unit12may be omitted and only the normal heating operation and the defrosting heating operation may be performed.

The aforementioned air-conditioning devices100(100aand100b) include a computer system therein. The processing steps of the erroneous installation-sensing process are stored in a computer-readable recording medium in the form of a program, and the process is performed by causing the computer to read and execute the program. The computer-readable recording medium is a magnetic disk, a magneto-optical disc, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. This computer program may be transmitted to a computer via a communication line, and the computer receiving the program may execute the program.