Patent Description:
The heat pump refers to a device that transmits a low-temperature heat to a high temperature or transmits a high-temperature heat to a low temperature by using the heat generation or condensation heat of a refrigerant. In general, it may include an outdoor unit including a compressor, an outdoor heat exchanger, and the like, and an indoor unit including an indoor heat exchanger, and the like.

The heat pump may be used for heating to increase the temperature of the room, or for hot water supply providing hot water to users, by heating water through heat exchange of refrigerant, thereby replacing the use of fossil fuels.

Conventionally, a chlorofluorocarbon (CFC)-based refrigerant known as freon gas was widely used, but as it was found to be the cause of destroying the ozone layer existing in the atmosphere, the use of chlorofluorocarbon-based refrigerants was prohibited, and various alternative refrigerants have been developed and used.

Meanwhile, among the alternative refrigerants, in the case of a refrigerant containing propane or isobutane as a main component, Ozone Depletion Potential (ODP) is <NUM>, and the Global Warming Potential (GWP) is also low in comparison with other alternative refrigerants, so it is in the spotlight as an eco-friendly refrigerant. However, due to its high flammability, there is a high possibility of a fire when a refrigerant leaks. In addition, in general, if sufficient refrigerant is not circulated due to refrigerant leakage, there are also problems such as low heat exchange efficiency and damage to the compressor.

Disclosure of Invention <CIT>discloses a refrigeration cycle apparatus having a controller which detects whether refrigerant leakage has occurred based on the detection value from a refrigerant leakage sensor. When a leakage of refrigerant is detected, a refrigerant recovery operation is started.

The present invention has been made in view of the above problems, and provides a heat pump capable of accurately determining whether a refrigerant is leaked according to various methods, and an operation method thereof.

The present invention further provides a heat pump capable of controlling the operation of valves so that the refrigerant is not leaked any more when the refrigerant is leaked, and an operation method thereof.

The present invention further provides a heat pump capable of preventing the refrigerant from entering indoors when a refrigerant is leaked, and discharging the refrigerant to the outside, and an operation method thereof.

In accordance with an aspect of the present invention, a heat pump is provided as defined in claim <NUM>, and includes a compressor for compressing a refrigerant, a plurality of shut-off valves, and a controller, wherein the controller determines whether the refrigerant leaks, closes the first shut-off valve when the refrigerant leaks, and closes the second shutoff valve when a sensing value of the pressure sensor is less than a preset reference pressure.

The heat pump further includes: a housing, a water refrigerant heat exchanger for heat-exchanging the refrigerant and water, an outdoor heat exchanger for heat-exchanging the refrigerant and outdoor air, a pressure sensor detecting a pressure of the refrigerant flowing between the compressor and the water refrigerant heat exchanger, and a first shut-off valve is disposed in a pipe connected to a discharge part of the compressor, and a second shut-off valve id disposed between the outdoor heat exchanger and the compressor.

The heat pump further includes an outdoor fan disposed in one side of the outdoor heat exchanger; and a ventilation fan for discharging air inside the housing to the outside, and the controller stops an operation of the compressor and drives the ventilation fan, when the second shutoff valve is closed.

The outdoor fan of the heat pump is disposed in a first area of the housing, the ventilation fan is disposed in a second area of the housing, and the housing includes a partition wall separating the first area and the second area from each other.

The water refrigerant heat exchanger of the heat pump is disposed in the second area of the housing.

The heat pump further includes a first temperature sensor for sensing an outdoor temperature; and a second temperature sensor disposed in a second area of the housing, and the controller determines that the refrigerant leaks, when a sensing value of the second temperature sensor is lower than a sensing value of the first temperature sensor by a certain reference or more.

The ventilation fan and the second temperature sensor of the heat pump are disposed adjacent to a bottom surface of the housing.

A density of the refrigerant is greater than that of air.

The heat pump further includes an expansion valve for expanding the refrigerant; and a third temperature sensor for sensing a temperature of the refrigerant discharged from the compressor, and the controller determines that the refrigerant leaks, when a sensing value of the third temperature sensor is equal to or higher than a preset reference temperature for a certain time, in a state where opening degree of the expansion valve is a maximum opening degree.

The controller of the heat pump according to the present invention calculates a power consumption of the compressor, and determines that the refrigerant leaks, when an operating frequency of the compressor is higher than or equal to a certain frequency, and the power consumption of the compressor is less than a certain power consumption.

The heat pump further includes a fourth temperature sensor for sensing a temperature of the outdoor heat exchanger, and the controller determines that the refrigerant leaks, when a difference between the sensing value of the first temperature sensor and a sensing value of the fourth temperature sensor is less than a certain reference value.

In accordance with another aspect of the present invention, a method of operating a heat pump is provided as defined in claim <NUM>, and includes: determining whether a refrigerant leaks; closing a first shutoff valve disposed in a pipe connected to a discharge part of a compressor for compressing the refrigerant, when the refrigerant leaks; and closing a second shutoff valve disposed between an outdoor heat exchanger for heat-exchanging the refrigerant with outdoor air and the compressor, when a sensing value of a pressure sensor detecting a pressure of the refrigerant flowing between a water refrigerant heat exchanger for heat-exchanging the refrigerant with water and the compressor is less than a preset reference pressure.

As described above, according to various embodiments of the present invention, it is possible to accurately determine whether the refrigerant leaks from various angles through various methods by using the sensing value of the internal temperature sensor, the sensing value of the discharge temperature sensor, the sensing value of the outdoor temperature sensor, the sensing value of the heat exchanger temperature sensor, the power consumption of the compressor, and the like.

In addition, according to various embodiments of the present invention, when the refrigerant leaks, the shut-off valves are closed so that the refrigerant does not leak any more, and the refrigerant can be discharged to the outdoors by driving the ventilation fan, thereby reducing the possibility of fire, and improving the safety and reliability of the product.

In addition, according to various embodiments of the present invention, even if the refrigerant leaks, it is possible to block refrigerant from entering the room, by disposing the water refrigerant heat exchanger in the outdoor unit so that the refrigerant circulates only inside the housing of the outdoor unit.

According to various embodiments of the present invention, it is possible to accurately determine whether a refrigerant leaks through various methods using sensors or the like.

In addition, according to various embodiments of the present invention, when the refrigerant leaks, the operation of valves is controlled so that the refrigerant does not leak anymore, and the refrigerant can be discharged to the outdoors by driving a ventilation fan, thereby reducing the possibility of fire and improving the safety and reliability of the product.

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description in conjunction with the accompanying drawings, in which:.

In order to clearly and briefly describe the present invention, components that are irrelevant to the description will be omitted in the drawings. The same reference numerals are used throughout the drawings to designate the same or similar components.

Terms "module" and "part" for elements used in the following description are given simply in view of the ease of the description, and do not carry any important meaning or role. Therefore, the "module" and the "part" may be used interchangeably.

It should be understood that the terms "comprise", "include", "have", etc. when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or combinations of them but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It will be understood that, although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. Further, terms defined in a common dictionary will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the drawings, the thicknesses or the sizes of elements and graphs may be exaggerated, omitted or simplified to more clearly and conveniently illustrate the present disclosure.

<FIG> is a schematic diagram of a system including a heat pump according to an embodiment of the present invention, and <FIG> is a configuration diagram of an outdoor unit of <FIG>.

Referring to <FIG> and <FIG>, a system <NUM> may include an outdoor unit <NUM>, a distribution unit <NUM>, a hot water supply unit <NUM>, a heating unit <NUM>, and/or an indoor unit <NUM>. Here, the outdoor unit <NUM> and/or the distribution unit <NUM> may be included in a heat pump.

The outdoor unit <NUM> may be connected to the distribution unit <NUM> through a plurality of outdoor pipes <NUM> and <NUM>. In this case, the outdoor unit <NUM> may be disposed outdoors, and the distribution unit <NUM> may be disposed indoors.

The outdoor unit <NUM> may receive water from the distribution unit <NUM> through any one of a plurality of outdoor pipes <NUM> and <NUM>, and may deliver water to the distribution unit <NUM> through another of the plurality of outdoor pipes <NUM> and <NUM>.

The outdoor unit <NUM> may include a compressor <NUM> that compresses the refrigerant, a compressor motor 102b for driving the compressor <NUM>, an accumulator <NUM> that temporarily stores the gasified refrigerant to remove moisture and foreign matter, and then supplies a refrigerant having a constant pressure to the compressor <NUM>, an outdoor heat exchanger <NUM> that serves to dissipate heat of the compressed refrigerant, an outdoor blower <NUM> including an outdoor fan 105a disposed in one side of the outdoor heat exchanger <NUM> to promote heat dissipation of refrigerant and an outdoor fan motor 105b for rotating the outdoor fan 105a, a main valves <NUM> (e.g., electronic expansion valves (EEV)) for expanding the condensed refrigerant, a water refrigerant heat exchanger <NUM> for heat-exchanging refrigerant and water, and/or a cooling/heating switching valve <NUM> that changes the flow path of the compressed refrigerant. In addition, the outdoor unit <NUM> may further include a plurality of sensors.

The refrigerant compressed by the compressor <NUM> of the outdoor unit <NUM> may have a higher density than air. The refrigerant may be a refrigerant containing propane, isobutene, or the like.

The outdoor unit <NUM> may operate according to the mode of the heat pump. For example, when the heat pump is set to a cooling mode, the outdoor unit <NUM> may operate to move the refrigerant compressed by the compressor <NUM> to the water refrigerant heat exchanger <NUM> through the outdoor heat exchanger <NUM>. In addition, when the heat pump is set to a heating mode, the outdoor unit <NUM> may operate to move the refrigerant compressed by the compressor <NUM> to the outdoor heat exchanger <NUM> through the water refrigerant heat exchanger <NUM>.

The outdoor unit <NUM> may include a sub valve <NUM> that adjusts the amount of refrigerant injected into the compressor <NUM>. Here, the sub valve <NUM> may be an electronic expansion valve (EEV). When the refrigerant is injected into the compressor <NUM> through the sub-valve <NUM>, it is possible to overcome the limitation of refrigerant suction which is limited by the density of the refrigerant sucked into the compressor <NUM> and the volume of a compression chamber of the compressor <NUM>, thereby improving the compression capacity of the compressor <NUM>. Through this, it is possible to increase the amount of refrigerant to be circulated, and to improve the performance of the cooling operation or heating operation of the heat pump.

Meanwhile, the outdoor unit <NUM> may additionally include a super-cooling heat exchanger (not shown) for heat exchange of the refrigerant expanded through the sub valve <NUM>.

The outdoor unit <NUM> includes at least one shutoff valve <NUM>, <NUM> that blocks movement of the refrigerant. At least one of the shut-off valves <NUM> and <NUM> may be a <NUM>-way valve.

The first shutoff valve <NUM> is disposed in a flow path through which the refrigerant compressed by the compressor <NUM> is discharged and moves to the outdoor heat exchanger <NUM> or the water refrigerant heat exchanger <NUM>. For example, the first shutoff valve <NUM> may be disposed in a pipe connected to the discharge portion of the compressor <NUM> through which the compressed refrigerant is discharged.

The second shutoff valve <NUM> is disposed in a flow path through which the refrigerant moves to the compressor <NUM> through the outdoor heat exchanger <NUM> and the water refrigerant heat exchanger <NUM>. For example, the second shut-off valve <NUM> may be disposed in a pipe connecting the accumulator <NUM> and the cooling/heating switching valve <NUM>.

The water refrigerant heat exchanger <NUM> may be connected to a plurality of outdoor pipes <NUM> and <NUM>. Water supplied through any one of the plurality of outdoor pipes <NUM> and <NUM> may be discharged through the other one of the plurality of outdoor pipes <NUM> and <NUM> after heat exchange with the refrigerant.

The outdoor unit <NUM> may further include an outdoor pump (<NUM> in <FIG>) that pumps water circulating through the water refrigerant heat exchanger <NUM>.

The distribution unit <NUM> may supply water to the outdoor unit <NUM> through any one of the plurality of outdoor pipes <NUM> and <NUM>, and may be supplied with water from the outdoor unit <NUM> through the other one of the plurality of outdoor pipes <NUM> and <NUM>. For example, when the heat pump is set to the heating mode, cold water may be supplied to the outdoor unit <NUM> and hot water may be supplied from the outdoor unit <NUM>.

The distribution unit <NUM> may include a flow sensor (not shown) that detects a flow rate of water, a pump (not shown) that pumps water circulating through the distribution unit <NUM>, an expansion tank (not shown), and an air vent valve (not shown) that discharges air.

Meanwhile, the distribution unit <NUM> may be connected to the hot water supply unit <NUM>, the heating unit <NUM>, and/or the indoor unit <NUM> through a plurality of indoor pipes <NUM> and <NUM>.

The distribution unit <NUM> may distribute the water supplied from the outdoor unit <NUM> to at least one of the hot water supply unit <NUM>, the heating unit <NUM>, and the indoor unit <NUM>, through a plurality of indoor pipes <NUM> and <NUM>, and may supply the water delivered from at least one of the hot water supply unit <NUM>, the heating unit <NUM>, and the indoor unit <NUM> to the outdoor unit <NUM>. To this end, the distribution unit <NUM> may further include a plurality of valves (not shown) for distributing water.

The heating unit <NUM> may include a heat dissipation pipe (not shown) connected to the plurality of indoor pipes <NUM> and <NUM>. For example, the hot water supplied through any one of the plurality of indoor pipes <NUM> and <NUM> may move along the heat dissipation pipe to heat the indoor floor, and the cold water discharged after performing heat-exchange through the heat dissipation pipe may be delivered to the distribution unit <NUM> through the other one of the plurality of indoor pipes <NUM> and <NUM>.

The indoor unit <NUM> is applicable to any of a stand type air conditioner, a wall-mounted type air conditioner, and a ceiling type air conditioner, but in the drawing, a ceiling type air conditioner is illustrated.

The indoor unit <NUM> may include an indoor heat exchanger (not shown), an indoor fan (not shown), and a plurality of sensors (not shown).

The indoor heat exchanger may heat-exchange air with cold water or hot water supplied from the distribution unit <NUM>. The indoor fan may discharge the air heat-exchanged in the indoor heat exchanger into the room, through rotation.

<FIG> is an example of a front view of the outdoor unit of <FIG>, and <FIG> is an example of an inner front view of the outdoor unit of <FIG>.

Referring to <FIG> and <FIG>, one surface of the housing <NUM> of the outdoor unit <NUM> may include an area in which air heat exchanged by the outdoor heat exchanger <NUM> is discharged to the outside according to the rotation of the outdoor fan 105a.

Meanwhile, the outdoor unit <NUM> may further include a ventilation fan <NUM> that discharges air inside the housing <NUM> to the outside according to rotation. In this case, the ventilation fan <NUM> may be disposed in one surface of the housing <NUM> and exposed to the outside.

The ventilation fan <NUM> may include an impeller. The ventilation fan <NUM> may further include a filter (not shown) that blocks foreign matter such as dust flowing into the housing <NUM> from the outside.

The ventilation fan <NUM> may be disposed at a lower end adjacent to the bottom surface of the housing <NUM>.

Meanwhile, the housing <NUM> may include a partition wall <NUM> that separates a first area in which the outdoor heat exchanger <NUM> and the outdoor fan 105a are disposed, and a second area in which the compressor <NUM>, the water refrigerant heat exchanger <NUM>, the outdoor pump <NUM>, the control circuit module <NUM>, and the like are disposed, from each other, and above mentioned two areas may be spatially separated from each other by the partition wall <NUM>. The ventilation fan <NUM> may be disposed in correspondence with the second area so as to discharge the air inside the second area to the outside.

The outdoor unit <NUM> may further include an internal temperature sensor <NUM> that detects the temperature inside the housing <NUM>. The internal temperature sensor <NUM> may be disposed in a lower end adjacent to the bottom surface of the second area of the housing <NUM>.

<FIG> is a block diagram of a heat pump according to an embodiment of the present invention.

Referring to <FIG>, the heat pump may include a fan driving unit <NUM>, a compressor driving unit <NUM>, a valve unit <NUM>, a sensor unit <NUM>, and/or a controller <NUM>.

The fan driving unit <NUM> may drive at least one fan provided in the heat pump. For example, the fan driving unit <NUM> may drive the outdoor fan 105a and/or the ventilation fan <NUM>.

The fan driving unit <NUM> may include a rectifier (not shown) that rectifies AC power into DC power and outputs the rectified AC power, a DC terminal capacitor that stores a pulsating voltage from the rectifier, an inverter (not shown) that has a plurality of switching elements and converts a smoothed DC power to a three-phase AC power having a certain frequency and outputs the three-phase AC power, and/or a motor (not shown) for driving a fan according to the three-phase AC power output from the inverter.

The fan driving unit <NUM> may have separate configurations for driving the outdoor fan 105a and the ventilation fan <NUM>, respectively. For example, the fan driving unit <NUM> may include an outdoor fan motor 105b for rotating the outdoor fan 105a and a ventilation fan motor (not shown) for rotating the ventilation fan <NUM>, respectively.

The compressor driving unit <NUM> may drive the compressor <NUM>.

The compressor driving unit <NUM> may include a rectifier (not shown) that rectifies AC power to DC power and outputs the DC power, a DC terminal capacitor (not shown), a compressor motor 102b that drives the compressor <NUM> according to an inverter (not shown) and/or a three-phase AC power output from the inverter.

The valve unit <NUM> may include at least one valve. At least one valve included in the valve unit <NUM> may operate under the control of the controller <NUM>. For example, the valve unit <NUM> may include a main valve <NUM>, a sub valve <NUM>, a cooling/heating switching valve <NUM>, and/or at least one shut-off valve <NUM>, <NUM>.

The sensor unit <NUM> may include at least one sensor, and may transmit data on a sensing value detected through at least one sensor to the controller <NUM>.

At least one sensor provided in the sensor unit <NUM> may be disposed inside the outdoor unit <NUM>, the distribution unit <NUM>, the indoor unit <NUM>, and the like. For example, the sensor unit <NUM> may include a heat exchanger temperature sensor disposed in the outdoor heat exchanger <NUM>, at least one pressure sensor detecting a pressure of a refrigerant flowing through each pipe, at least one pipe temperature sensor for detecting the temperature of fluid flowing through each pipe, and the like.

The sensor unit <NUM> may include an indoor temperature sensor that detects an indoor temperature and/or an outdoor temperature sensor that detects an outdoor temperature. For example, the outdoor temperature sensor may be disposed in the outdoor unit <NUM>, and the indoor temperature sensor may be disposed in the indoor unit <NUM>.

The sensor unit <NUM> may include an internal temperature sensor <NUM> that detects a temperature inside the housing <NUM> of the outdoor unit <NUM>.

The controller <NUM> may be connected to each component provided in the heat pump, and control the overall operation of each component. The controller <NUM> may transmit/ receive data to and from each component provided in the heat pump.

The controller <NUM> may be provided not only in the outdoor unit <NUM>, but also in the distribution unit <NUM>, a remote control device (not shown) that remotely controls the operation of the heat pump, and the like. For example, the controller <NUM> may be included in the control circuit module <NUM> disposed inside the housing of the outdoor unit <NUM>.

The controller <NUM> may include at least one processor, and may control the overall operation of the heat pump by using the processor included therein. Here, the processor may be a general processor such as a central processing unit (CPU). Obviously, the processor may be a dedicated device such as an ASIC or another hardware-based processor.

The controller <NUM> may control an operation of the fan driving unit <NUM>. For example, the controller <NUM> may change the number of rotations of the outdoor fan 105a by changing the frequency of the three-phase AC power output to the outdoor fan motor 105b through the operation control of the fan driving unit <NUM>.

The controller <NUM> may control the operation of the compressor driving unit <NUM>. For example, the controller <NUM> may change the operating frequency of the compressor <NUM> by changing the frequency of the three-phase AC power output to the compressor motor 102b through the operation control of the compressor driving unit <NUM>.

The controller <NUM> may control an operation of at least one valve included in the valve unit <NUM> according to the mode of the heat pump. For example, when the heat pump is set to a cooling mode, and when the refrigerant compressed by the compressor <NUM> moves to the water refrigerant heat exchanger <NUM> through the outdoor heat exchanger <NUM> and the heat pump is set to the heating mode, the controller <NUM> may control the operation of the cooling/heating switching valve <NUM> so that the refrigerant compressed by the compressor <NUM> moves to the outdoor heat exchanger <NUM> through the water refrigerant heat exchanger <NUM>.

The controller <NUM> may control an operation of each component provided in the heat pump, based on a sensing value of at least one sensor included in the sensor unit <NUM>. For example, the controller <NUM> may determine whether a refrigerant leaks, based on the sensing value of at least one sensor included in the sensor unit <NUM>, and may control the operation of each configuration provided in the heat pump according to whether the refrigerant leaks.

The controller <NUM> may determine whether the refrigerant leaks, based on the sensing value of the internal temperature sensor <NUM> and the sensing value of the outdoor temperature sensor. For example, when the outdoor unit <NUM> is installed outdoors, the sensing value of the internal temperature sensor <NUM> and the sensing value of the outdoor temperature sensor are similarly detected within a certain reference. However, when a refrigerant containing propane, isobutene, or the like having a low boiling point leaks, the ambient temperature drops sharply. Therefore, the sensing value of the internal temperature sensor <NUM> may also be rapidly lowered. In this case, when the sensing value of the internal temperature sensor <NUM> is lower than the sensing value of the outdoor temperature sensor by a certain reference or more, the controller <NUM> may determine that the refrigerant leaks. The controller <NUM> may determine whether the refrigerant leaks, based on the amount of change in the sensing value of the internal temperature sensor <NUM>.

The controller <NUM> may determine whether the refrigerant leaks, based on a sensing value of a discharge temperature sensor (not shown) that detects the temperature of the refrigerant discharged from the compressor <NUM>. For example, when the sensing value of the discharge temperature sensor is higher than or equal to a preset reference temperature, the controller <NUM> may determine that the amount of refrigerant circulated is insufficient and may increase the opening degree amount of the main valve <NUM>. At this time, in a state where the opening degree of the main valve <NUM> is the maximum opening degree, when the sensing value of the discharge temperature sensor (not shown) that detects the temperature of the refrigerant discharged from the compressor <NUM> is higher than or equal to a preset reference temperature for a certain time, the controller <NUM> may determine that the refrigerant leaks.

The controller <NUM> according to the present invention determines whether the refrigerant leaks, based on the operating frequency and power consumption of the compressor <NUM>. For example, when the amount of refrigerant compressed by the compressor <NUM> is insufficient, power consumption of the compressor <NUM> may be significantly lower than when the amount of refrigerant is sufficient due to idle rotation of the compressor motor 102b. In this case, when the operating frequency of the compressor <NUM> is higher than or equal to a certain frequency and the power consumption of the compressor <NUM> is less than a certain power consumption, the controller <NUM> determines that the refrigerant leaks. Here, the certain power consumption is a value corresponding to a certain frequency.

The controller <NUM> may determine whether the refrigerant leaks, based on the sensing value of the outdoor temperature sensor and the sensing value of the heat exchanger temperature sensor. For example, in the outdoor heat exchanger <NUM>, heat exchange occurs due to the difference between the outdoor temperature and the temperature of the refrigerant, but when the refrigerant is insufficient, the heat exchange efficiency decreases, and the difference between the outdoor temperature and the temperature of the refrigerant may gradually decrease. In this case, when the difference between the sensing value of the outdoor temperature sensor and the sensing value of the heat exchanger temperature sensor is less than a certain reference value, the controller <NUM> may determine that the refrigerant leaks.

When it is determined that the refrigerant leaks, the controller <NUM> may control the operation of at least one valve included in the valve unit <NUM>.

When it is determined that the refrigerant leaks, the controller <NUM> may close the first shutoff valve <NUM> so that the refrigerant discharged from the compressor <NUM> may be blocked from being moved to the outdoor heat exchanger <NUM> or the water refrigerant heat exchanger <NUM>.

When the first shut-off valve <NUM> is closed, the controller <NUM> may check whether the sensing value of a first pressure sensor (not shown) that detects the pressure of the refrigerant flowing between the compressor <NUM> and the water refrigerant heat exchanger <NUM> is lower than a preset reference pressure. Here, the first pressure sensor may be disposed in a pipe connecting the cooling/heating switching valve <NUM> and the water refrigerant heat exchanger <NUM>.

When the sensing value of the first pressure sensor is less than a preset reference pressure, the controller <NUM> may determine that the refrigerant flowing in each pipe of the outdoor unit <NUM> moved to the compressor <NUM> and the accumulator <NUM> by a certain amount or more, and may close the second shutoff valve <NUM>. In this case, the controller <NUM> may control the main valve <NUM> and/or the sub valve <NUM> to have a minimum opening degree.

When the second shutoff valve <NUM> is closed, the controller <NUM> may control the compressor driving unit <NUM> to stop the operation of the compressor <NUM>. When the second shutoff valve <NUM> is closed, the controller <NUM> may control the fan driving unit <NUM> to drive the ventilation fan motor of the fan driving unit <NUM> so that the ventilation fan <NUM> rotates.

Meanwhile, the heat pump may further include an output unit (not shown).

The output unit may include a display device, such as a display, and a light emitting diode (LED), and may display a message related to a refrigerant leakage through the display device.

The output unit may include an audio device such as a speaker, and a buzzer, and may output a warning sound for refrigerant leakage through the audio device.

<FIG> is a flowchart illustrating a method of operating a heat pump according to an embodiment of the present invention.

Referring to <FIG>, the heat pump may monitor whether a refrigerant leaks, at operations S610 and S620.

For example, when the sensing value of the internal temperature sensor <NUM> is lower than the sensing value of the outdoor temperature sensor by a certain reference or more, the heat pump may determine that the refrigerant leaks.

For example, in a state in which the opening degree of the main valve <NUM> is the maximum opening degree, when the sensing value of the discharge temperature sensor for detecting the temperature of the refrigerant discharged from the compressor <NUM> is higher than or equal to a preset reference temperature for a certain time, the heat pump may determine that the refrigerant leaks.

For example, the heat pump may determine that the refrigerant leaks, when the operating frequency of the compressor <NUM> is equal to or higher than a certain frequency, and the power consumption of the compressor <NUM> is less than a certain power consumption.

For example, when the difference between the sensing value of the outdoor temperature sensor and the sensing value of the heat exchanger temperature sensor is less than a certain reference value, the heat pump may determine that the refrigerant leaks.

At this time, the heat pump may independently perform a plurality of methods of monitoring whether the refrigerant leaks, or may be sequentially performed.

When the refrigerant leaks, the heat pump closes the first shutoff valve <NUM>, thereby blocking the refrigerant discharged from the compressor <NUM> from moving to the outdoor heat exchanger <NUM> or the water refrigerant heat exchanger <NUM>, at operation S630.

The heat pump may check whether the sensing value of the first pressure sensor for detecting the pressure of the refrigerant flowing between the compressor <NUM> and the water refrigerant heat exchanger <NUM> is lower than a preset reference pressure, in a state in which the first shutoff valve <NUM> is closed, at operation S640.

When the sensing value of the first pressure sensor is less than a preset reference pressure, the heat pump may determine that the refrigerant flowing in each pipe of the outdoor unit <NUM> moved to the compressor <NUM> and the accumulator <NUM> by a certain amount or more, and may close the second shutoff valve <NUM>, at operation S650.

The heat pump may control the compressor driving unit <NUM> to stop the operation of the compressor <NUM>, at operation S660.

The heat pump may drive the ventilation fan <NUM> to discharge the leaked refrigerant together with the air inside the housing <NUM> to the outside, at operation S670.

As described above, according to various embodiments of the present invention, it is possible to accurately determine whether the refrigerant leaks from various angles through various methods by using the sensing value of the internal temperature sensor <NUM>, the sensing value of the discharge temperature sensor, the sensing value of the outdoor temperature sensor, the sensing value of the heat exchanger temperature sensor, the power consumption of the compressor <NUM>, and the like.

In addition, according to various embodiments of the present invention, when the refrigerant leaks, the shut-off valves <NUM> and <NUM> are closed so that the refrigerant does not leak any more, and the refrigerant can be discharged to the outdoors by driving the ventilation fan <NUM>, thereby reducing the possibility of fire, and improving the safety and reliability of the product.

In addition, according to various embodiments of the present invention, even if the refrigerant leaks, it is possible to block refrigerant from entering the room, by disposing the water refrigerant heat exchanger <NUM> in the outdoor unit <NUM> so that the refrigerant circulates only inside the housing <NUM> of the outdoor unit <NUM>.

Since the accompanying drawings are merely for easily understanding embodiments disclosed herein, it should be understood that the technical spirit disclosed herein is not limited by the accompanying drawings, and the scope of the present invention is solely defined by the appended claims.

Claim 1:
A heat pump comprising:
a housing (<NUM>) disposed outdoors;
a compressor (<NUM>) configured to compress a refrigerant;
a water refrigerant heat exchanger (<NUM>) configured to perform heat exchange between the refrigerant and water;
an outdoor heat exchanger (<NUM>) configured to perform heat exchange between the refrigerant and outdoor air;
a pressure sensor configured to detect a pressure of the refrigerant flowing between the compressor (<NUM>) and the water refrigerant heat exchanger (<NUM>);
a first shut-off valve (<NUM>) disposed in a pipe connected to a discharge part of the compressor (<NUM>);
a second shut-off valve (<NUM>) disposed between the outdoor heat exchanger (<NUM>) and the compressor (<NUM>); and
a controller (<NUM>) configured to:
calculate a power consumption of the compressor (<NUM>),
determine that the refrigerant leaks, when an operating frequency of the compressor (<NUM>) is higher than or equal to a certain frequency and the power consumption of the compressor (<NUM>) is less than a certain power consumption corresponding to the certain frequency,
control the first shut-off valve (<NUM>) to be closed when the refrigerant leaks, and
control the second shutoff valve (<NUM>) to be closed when a sensing value of the pressure sensor is less than a preset reference pressure.