Patent Description:
In general, an air conditioner includes a refrigeration cycle, and is an apparatus configured to heat or cool an indoor space by implementation of the refrigeration cycle. An example of such a device is disclosed in <CIT>, which comprises a room warming/cooling and hot water supplying heat pump apparatus with a four-way valve, room-side heat exchanger, an expansion device and an outdoor side heat exchanger.

In recent years, various kinds of air conditioners have been developed. For example, there is an air conditioner, such as in the <CIT>, to allow hot water generated by a hot water generator to be used to heat the indoor space or supply hot water. Such an air conditioner includes an indoor unit to directly exchange heat with indoor air so as to heat and cool the indoor space, and a hot water generator to heat water using high temperature refrigerant supplied to the hot water generator from a compressor of an outdoor unit.

The present invention has the object of providing an air conditioner with a reliable indoor heating operation during simultaneous indoor heating & hot water generation.

This object is achieved by an air conditioner according to claim <NUM> and a control method of an air conditioner according to claim <NUM>.

The present invention provides a control method of an air conditioner, the air conditioner including an outdoor unit, one or more indoor units to heat an indoor space by refrigerant supplied from the outdoor unit, and a hot water generator to heat water by the refrigerant supplied from the outdoor unit. The control method includes controlling supply of the refrigerant by a control unit so that the refrigerant is first supplied to one or more indoor units in operation from the outdoor unit, and is then supplied to the hot water generator. The controlling supply of the refrigerant is executed by controlling an opening degree of a hot water expansion valve provided at the hot water generator, sensing a pressure at a discharge side of a compressor of the outdoor unit, controlling a supply of refrigerant to one or more of the one or more indoor units and the hot water generator based on the sensed pressure of the refrigerant at the discharge side of the compressor of the outdoor unit to prevent the refrigerant from cooling the one or more indoor units or the hot water generator by identifying whether none of the one or more indoor units in operation, identifying whether a pressure at a discharge side of a compressor in the outdoor unit is less than a reference pressure, and if the identified pressure at the discharge side of the compressor is less than the reference pressure and if anyone of the one or more one indoor units is identified as being in operation, then opening the hot water expansion valve to the minimum opening degree.

The control method of the air conditioner may further include identifying whether there is not any one indoor unit in operation among the indoor units, and if there is no indoor unit in operation, opening the hot water expansion valve of the hot water generator to the maximum opening degree thereof.

The control method of the air conditioner may further include identifying whether there is not any one indoor unit in operation among the indoor units, if there is any one indoor unit in operation, identifying a temperature of water which is discharged from the hot water generator, and if the temperature of the discharge water is less than a reference temperature, opening the hot water expansion valve to the minimum opening degree thereof.

The control method of the air conditioner may further include identifying whether there are one or more indoor units in operation among the indoor units, identifying the amount of refrigerant used being used in one or more indoor units in operation among the indoor units, summing all the amount of refrigerant used in one or more indoor units in operation to calculate the total amount of refrigerant used, and opening the hot water expansion valve to the opening degree thereof corresponding to the total amount of refrigerant used.

When the total amount of refrigerant used in one or more indoor units is relatively great, the hot water expansion valve may be opened to the relatively small opening degree thereof, and when the total amount of refrigerant used in one or more indoor units is relatively less, the hot water expansion valve may be opened to the relatively great opening degree thereof.

Each of the maximum total amount of refrigerant used in one or more indoor units and the maximum amount of refrigerant used in the hot water generator may be equal to the amount of refrigerant supplied from the outdoor unit, and the sum of the total amount of refrigerant used in one or more indoor units in operation among the indoor units and the amount of refrigerant used in the hot water generator in operation may be equal to or lesser than the amount of refrigerant supplied from the outdoor unit.

In accordance with another aspect of the present invention provides an air conditioner including an outdoor unit, one or more indoor units to heat an indoor space by refrigerant supplied from the outdoor unit, a hot water generator to heat water by refrigerant supplied from the outdoor unit, a hot water expansion valve arranged at the hot water generator to control the amount of refrigerant which is supplied to the hot water generator, the hot water expansion valve being formed as a flow regulating valve capable of controlling an opening degree thereof, and a control unit configured to allow the hot water expansion valve to be opened to an opening degree thereof corresponding to the total amount of refrigerant used being used in the one or more indoor units, to identify the pressure at a discharge side of the compressor of the outdoor unit, and to control the opening of the hot water expansion valve to a minimum opening degree based on if the identified pressure at the discharge side of the compressor is less than the reference pressure and if anyone of the one or more one indoor units is identified as being in operation.

The control unit may identify whether there is not any one indoor unit in operation, and then open the hot water expansion valve to the maximum opening degree thereof when there is no indoor unit in operation.

The outdoor unit includes a compressor to compress refrigerant and a pressure sensing sensor to sense a pressure at a discharge side of the compressor, and the control unit identifies the pressure at the discharge side of the compressor, and then open the hot water expansion valve to the minimum opening degree thereof when the pressure at the discharge side of the compressor is equal to or lesser than a reference pressure.

The hot water generator may include a heating tank to heat water by refrigerant and a discharge water temperature sensing sensor to sense a temperature of water which is discharged from the heating tank, and the control unit may identify the temperature of the water which is discharged from the heating tank, and then open the hot water expansion valve to the minimum opening degree thereof when the temperature of the discharge water is equal to or lesser than a reference temperature.

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

As shown in <FIG>, an air conditioner according to an exemplary embodiment of the present disclosure includes an outdoor unit <NUM> arranged at an outdoor space to exchange heat with outdoor air, indoor units <NUM> to exchange heat with indoor air so as to heat and cool indoor spaces, respectively, a hot water generator <NUM> to heat water by refrigerant so as to generate hot water, and a hot water consuming device <NUM> to use the hot water generated by the hot water generator <NUM>. In such an air conditioner, hot or cold air generated through implementation of the refrigeration cycle of the air conditioner may be used to heat and cool the indoor space, and hot water generated by the hot water generator <NUM> may be supplied to the hot water consuming device <NUM> such as a floor heater or a hot water supply device.

The outdoor unit <NUM> includes a compressor <NUM> to compress refrigerant, an outdoor heat exchanger <NUM> to allow the refrigerant to exchange heat with outdoor air, a four-way valve <NUM> to selectively supply the refrigerant compressed by the compressor <NUM> to any one of the outdoor heat exchanger <NUM> and each indoor unit <NUM>, and a pressure sensing sensor <NUM> to sense pressure of the refrigerant discharged from the compressor <NUM>, namely, pressure of the refrigerant which passes through a path provided at a discharge side of the compressor <NUM>.

The indoor unit <NUM> is comprised of a plurality of indoor units <NUM> which may independently heat and cool a plurality of indoor spaces, respectively. Such an indoor unit <NUM> is a device to heat and cool the indoor space while allowing the refrigerant supplied from the outdoor unit <NUM> to exchange heat with indoor air. Each indoor unit <NUM> includes an indoor heat exchanger <NUM> to allow the refrigerant to exchange heat with indoor air, and an air conditioning expansion valve <NUM> to decompress and expand the refrigerant.

The hot water generator <NUM> is a device to heat water by the refrigerant supplied from the outdoor unit <NUM> so as to generate hot water. The hot water generator <NUM> includes a heating tank <NUM> to heat water while allowing the refrigerant supplied from the outdoor unit <NUM> to exchange heat with water supplied from the hot water consuming device <NUM>, a hot water expansion valve <NUM> to decompress and expand the refrigerant passing through the heating tank <NUM>, and a discharge water temperature sensing sensor <NUM> to sense temperature of the hot water which is supplied to the hot water consuming device <NUM> from the heating tank <NUM> after undergoing heat exchange with the refrigerant in the heating tank <NUM>. Herein, the hot water expansion valve <NUM> is a flow regulating valve capable of controlling an opening degree thereof to regulate the amount of refrigerant which is supplied to the hot water generator <NUM>.

In this case, indoor heating by the indoor units <NUM> and hot water generation by the hot water generator <NUM> may be performed independently of each other. Consequently, either the maximum total amount of refrigerant used in the indoor units when all indoor units <NUM> are operated or the maximum amount of refrigerant used in the hot water generator <NUM> when the hot water generator <NUM> is operated at full load is practically equal to the amount of refrigerant supplied from the outdoor unit <NUM>. Also, when the indoor heating by the indoor units <NUM> is performed simultaneously with the hot water generation by the hot water generator <NUM>, the sum of the total amount of refrigerant used in indoor units <NUM> and the amount of refrigerant used in the hot water generator <NUM> is always maintained at or below the amount of refrigerant supplied from the outdoor unit <NUM>, in order to prevent generation of a cold wind in the indoor units <NUM>.

As shown in <FIG>, the air conditioner also includes a control unit <NUM> to control overall operation of the air conditioner, a valve drive unit <NUM> to control the air conditioning expansion valve <NUM> and the hot water expansion valve <NUM>, and a compressor drive unit <NUM> to control the compressor <NUM>. In detail, the control unit <NUM> controls the air conditioning expansion valve <NUM>, the hot water expansion valve <NUM>, and the compressor <NUM> by the valve drive unit <NUM> and the compressor drive unit <NUM>, based on pressure and temperature information transferred from the pressure sensing sensor <NUM> and discharge water temperature sensing sensor <NUM> described above.

Hereinafter, a control method of the air conditioner configured as described above will be described in detail with reference to <FIG>.

The control method of the air conditioner according to the present exemplary embodiment sums the amount of refrigerant used being used in one or more indoor units <NUM> in operation among a plurality of indoor units <NUM> to derive the total amount of refrigerant used ΣQ, and then opens the hot water expansion valve <NUM> to the opening degree thereof corresponding to the total amount of refrigerant used ΣQ, thereby regulating the amount of refrigerant which is supplied to the hot water generator <NUM>. That is, the hot water expansion valve <NUM> is controlled so that refrigerant is first supplied to one or more indoor units <NUM> in operation from the outdoor unit <NUM>, and is then supplied to the hot water generator <NUM>. This serves to uniformly maintain the amount of refrigerant which is supplied to the indoor units <NUM>, regardless of whether or not the hot water generator <NUM> is operated. Therefore, in accordance with the above-mentioned configuration, it may be possible to prevent the refrigerant, which may be inadequately supplied to one or more of the indoor units <NUM> when the hot water generator <NUM> is operated during heating operation mode, from causing generation of a cold wind in the indoor units <NUM>.

To this end, the control method of the air conditioner, if the hot water generator <NUM> is operated by a user (operation <NUM>), first identifies whether there is not any one indoor unit <NUM> in operation among a plurality of indoor units <NUM> (operation <NUM>). Thereafter, if there is no indoor unit <NUM> in operation among a plurality of indoor units <NUM>, the hot water expansion valve <NUM> is opened to the maximum opening degree thereof (operation <NUM>). In other words, if there is no indoor unit <NUM> in operation among a plurality of indoor units <NUM>, all refrigerant supplied from the outdoor unit <NUM> is used to operate the hot water generator <NUM>.

On the contrary, the control method of the air conditioner senses refrigerant pressure P at the discharge side of the compressor <NUM> by the pressure sensing sensor <NUM> (operation <NUM>) if there is any one indoor unit <NUM> in operation among a plurality of indoor units <NUM>, and then indentifies whether the sensed refrigerant pressure P is less than the reference pressure Pref (operation <NUM>). If the refrigerant pressure P is less than the reference pressure Pref, the hot water expansion valve <NUM> is opened to the minimum opening degree thereof (operation <NUM>).

In this case, the reference pressure Pref is the refrigerant pressure P at the discharge side of the compressor <NUM> during an operation mode of all the indoor units <NUM>. Accordingly, when the hot water generator <NUM> is operated in a state in which the pressure at the discharge side of the compressor <NUM> is less than the reference pressure Pref, the refrigerant may be inadequately supplied to one or more of the indoor units <NUM>. As a result, generation of a cold wind may be caused in the indoor units <NUM> in heating operation. Therefore, in such a case, the hot water generator <NUM> is opened to the minimum opening degree thereof so that the hot water generator <NUM> is practically not operated while preventing the refrigerant from remaining in the hot water generator <NUM>.

Further, the control method of the air conditioner senses temperature T of water which is discharged from the heating tank <NUM> of the hot water generator <NUM> by the discharge water temperature sensing sensor <NUM> mounted at the hot water generator <NUM> (operation <NUM>) if the pressure P at the discharge side of the compressor <NUM> is equal to or greater than the reference pressure Pref, and then indentifies whether the sensed discharge water temperature T is less than the reference temperature Tref (operation <NUM>).

If the discharge water temperature T is less than the reference temperature Tref, the refrigerant to exchange heat with water while passing through the heating tank <NUM> may be rapidly cooled by the water, thereby rapidly dropping the refrigerant pressure P at the discharge side of the compressor <NUM>. Accordingly, when the refrigerant pressure P at the discharge side of the compressor <NUM> is rapidly dropped, the refrigerant may be inadequately supplied to one or more of the indoor units <NUM>. As a result, generation of a cold wind may be caused in the indoor units <NUM> in heating operation. Therefore, when the discharge water temperature T is less than the reference temperature Tref, the hot water generator <NUM> is opened to the minimum opening degree thereof so that the hot water generator <NUM> is practically not operated while preventing the refrigerant from remaining in the hot water generator <NUM>.

Although the above-mentioned method senses the pressure P at the discharge side of the compressor <NUM> (operation <NUM>), and then senses the discharge water temperature T (operation <NUM>) if the pressure P at the discharge side of the compressor <NUM> is equal to or greater than the reference pressure Pref, the method may also be executed in reverse order. That is, the method may sense the discharge water temperature T (operation <NUM>), and then identify the pressure P at the discharge side of the compressor <NUM> (operation <NUM>) if the discharge water temperature T is equal to or greater than the reference temperature Tref.

Thereafter, the control method of the air conditioner, if the discharge water temperature T is equal to or greater than the reference temperature Tref, respectively identifies the amount of refrigerant used being used for heating in indoor units <NUM> in operation among a plurality of indoor units <NUM>, and then sums the amount of refrigerant used in each indoor unit <NUM> in operation to indentify the total amount of refrigerant used ΣQ (operation <NUM>). Subsequently, the hot water expansion valve <NUM> is opened to the opening degree thereof corresponding to the calculated total amount of refrigerant used ΣQ (operation <NUM>). That is, the opening degree of the hot water expansion valve <NUM> is controlled so that the remaining refrigerant, except for the total amount of refrigerant used ΣQ being used in the indoor units <NUM> in operation among refrigerant supplied from the outdoor unit <NUM>, is supplied to the hot water generator <NUM>.

In the present exemplary embodiment, a range of the total amount of refrigerant used ΣQ in one or more indoor units <NUM> in operation among a plurality of indoor units <NUM> is set in a multistage manner to control the opening degree of the hot water expansion valve <NUM> according to the set range of the total amount of refrigerant used. In other words, when the total amount of refrigerant used ΣQ is relatively great, the hot water expansion valve <NUM> is opened to the relatively small opening degree thereof to decrease the amount of refrigerant which is supplied to the hot water generator <NUM>. On the other hand, when the total amount of refrigerant used ΣQ is relatively less, the hot water expansion valve <NUM> is opened to the relatively great opening degree thereof to increase the amount of refrigerant which is supplied to the hot water generator <NUM>.

As described above, when the opening degree of the hot water expansion valve <NUM> is controlled according to the total amount of refrigerant used in one or more indoor units <NUM> in operation, the amount of refrigerant to be supplied to the indoor units <NUM> may be sufficient even when the hot water generator <NUM> is operated during heating operation by the indoor units <NUM>. As a result, it may be possible to prevent a cold wind from being generated in the indoor units <NUM>.

The present exemplary embodiment discloses an air conditioner including a plurality of indoor units <NUM>, but is not limited thereto. Thus, an air conditioner including a single indoor unit <NUM> may also be applied.

As is apparent from the above description, the air conditioner according to an aspect of the present disclosure may control the opening degree of the hot water expansion valve so that the remaining refrigerant, except for the total amount of refrigerant used being used in the indoor units among refrigerant supplied from the outdoor unit, is supplied to the hot water generator, thereby sufficiently supplying refrigerant to the indoor units in operation even when the hot water generator is operated.

Claim 1:
A control method of an air conditioner, wherein the air conditioner comprises an outdoor unit (<NUM>), one or more indoor units (<NUM>) to heat an indoor space through refrigerant supplied from the outdoor unit (<NUM>), and a hot water generator (<NUM>) to heat water through the refrigerant supplied from the outdoor unit (<NUM>),
controlling supply of the refrigerant by a control unit (<NUM>) so that the refrigerant is first supplied to one or more indoor units (<NUM>) in operation from the outdoor unit (<NUM>), and is then supplied to the hot water generator,
characterized by
wherein the controlling supply of the refrigerant is executed by controlling an opening degree of a hot water expansion valve (<NUM>) provided at the hot water generator (<NUM>);
sensing a pressure at a discharge side of a compressor of the outdoor unit;
controlling a supply of refrigerant to one or more of the one or more indoor units and the hot water generator based on the sensed pressure of the refrigerant at the discharge side of the compressor of the outdoor unit to prevent the refrigerant from cooling the one or more indoor units or the hot water generator by;
identifying whether none of the one or more indoor units is in operation;
identifying whether the pressure at the discharge side of a compressor of the outdoor unit is less than a reference pressure; and
if the identified pressure at the discharge side of the compressor is less than the reference pressure and if anyone of the one or more one indoor units is identified as being in operation, then opening the hot water expansion valve to a minimum opening degree.