Heat pump

Abstract

The invention relates to a heat pump. A heat pump according to an embodiment of the present invention comprises: a compressor that compresses a refrigerant; the liquid storage device is used for supplying a refrigerant to the compressor; the receiver is connected with the liquid storage device; a refrigerant-water heat exchanger that exchanges heat between the refrigerant and water; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; a four-way valve that guides the refrigerant discharged from the compressor to the refrigerant-water heat exchanger or the outdoor heat exchanger; an expansion valve disposed between the refrigerant-water heat exchanger and the outdoor heat exchanger; a first valve disposed between the refrigerant-water heat exchanger and the receiver; a second valve disposed between the compressor and the receiver; and a third valve disposed between the receiver and the reservoir.

Description

Technical Field

[0001] The present invention relates to a heat pump, and more particularly to a heat pump (HEAT PUMP) capable of operating in an optimal refrigerant state. Background Art

[0002] Generally, a heat pump refers to a device that cools or heats a room through the compression, condensation, expansion, and evaporation of a refrigerant. When the outdoor heat exchanger of the heat pump functions as a condenser and the indoor heat exchanger functions as an evaporator, the room can be cooled. When the indoor heat exchanger of the heat pump functions as a condenser and the outdoor heat exchanger functions as an evaporator, the room can be heated.

[0003] For example, the heat pump may be an air-to-water heat pump (AWHP) that uses water as a medium to perform heat exchange with a refrigerant. In this case, the temperature of water stored in a water tank may be increased by using water that is heated by heat exchange with the refrigerant, thereby supplying hot water to the room. Alternatively, as water that is heated by heat exchange with the refrigerant flows through a water pipe installed in the room, the room may be heated.

[0004] In the case of a multi-heat pump in which one outdoor unit is connected to multiple indoor units, the amount of refrigerant required varies depending on the number of indoor units in operation. In the case of an AWHP for heating water, in cooling operation, a large amount of refrigerant is required because an outdoor heat exchanger with a large internal volume is used as a condenser, and in heating operation, a small amount of refrigerant is required because a plate-type heat exchanger with a small internal volume is used as a condenser. If the refrigerant is sealed according to a certain condition of the refrigerant amount, the problem of reduced performance under other conditions will arise.

[0005] The prior art document (Korea Patent Publication No. 10-2023-0033633) discloses a structure in which a buffer tank is connected to the rear end of a condenser of a heat pump to store refrigerant and heat or cool the buffer tank. The structure disclosed in the prior art document is a structure for adjusting the temperature of the buffer tank in a short time, so it is difficult to selectively control the required refrigerant storage amount. Summary of the invention

[0006] The problem to be solved by the present invention is to provide a heat pump which can adjust the amount of refrigerant according to the operating state so as to operate in an optimal refrigerant state.

[0007] Another problem to be solved by the present invention is to provide a heat pump capable of actively adjusting the amount of circulating refrigerant according to the required amount of refrigerant.

[0008] Another problem to be solved by the present invention is to provide a heat pump capable of improving performance and efficiency.

[0009] Another problem to be solved by the present invention is to provide a heat pump that can operate with optimal performance and efficiency without shortage of refrigerant even in cooling operation.

[0010] Problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

[0011] In order to solve the above problem, the heat pump according to the embodiment of the present invention can actively store the refrigerant in the refrigerant storage device (receiver) or discharge the refrigerant stored in the refrigerant storage device according to the required amount of refrigerant, thereby operating in an optimal refrigerant state.

[0012] In order to solve the above problem, the heat pump of an embodiment of the present invention can operate in the optimal refrigerant state regardless of operating conditions such as indoor temperature, outdoor temperature, compressor frequency, and operating modes such as cooling and heating by using a device that can store refrigerant according to the required amount of refrigerant.

[0013] In order to solve the above problems, the heat pump of the embodiment of the present invention can seal the refrigerant according to the refrigerant amount under the maximum demand and adjust the refrigerant amount according to the operating state, thereby improving performance and efficiency. In particular, even in cooling operation, the refrigerant will not be insufficient and the heat pump can operate with optimal performance and efficiency.

[0014] The heat pump of an embodiment of the present invention includes: a compressor, which compresses refrigerant; an accumulator, which provides refrigerant to the compressor; a receiver, which is connected to the accumulator; a refrigerant-water heat exchanger, which exchanges heat between the refrigerant and water; an outdoor heat exchanger, which exchanges heat between the refrigerant and outdoor air; a four-way valve, which guides the refrigerant discharged from the compressor to the refrigerant-water heat exchanger or the outdoor heat exchanger; an expansion valve, which is arranged between the refrigerant-water heat exchanger and the outdoor heat exchanger; a first valve, which is arranged between the refrigerant-water heat exchanger and the receiver; a second valve, which is arranged between the compressor and the receiver; and a third valve, which is arranged between the receiver and the accumulator.

[0015] In heating operation, when the first valve and the third valve are opened, a portion of the refrigerant passing through the refrigerant-water heat exchanger can move to the receiver, and when the second valve and the third valve are opened, the refrigerant stored in the receiver can move to the accumulator.

[0016] The heat pump according to the embodiment of the present invention may further include a controller for controlling the opening and closing of the first valve, the second valve, and the third valve based on the amount of refrigerant during operation.

[0017] In the heating operation, if the degree of supercooling is higher than an upper limit reference value, the controller may control the first valve and the third valve to open, and in the heating operation, if the degree of supercooling is lower than a lower limit reference value, the controller may control the second valve and the third valve to open.

[0018] In the heating operation, the controller may control the four-way valve so that the refrigerant discharged from the compressor is guided to the refrigerant-water heat exchanger.

[0019] The heat pump according to the embodiment of the present invention may further include a capillary tube disposed between the third valve and the liquid reservoir.

[0020] The heat pump according to the embodiment of the present invention may further include a fourth valve disposed between the outdoor heat exchanger and the receiver.

[0021] In cooling operation, when the fourth valve and the third valve are opened, a portion of the refrigerant passing through the outdoor heat exchanger can move to the receiver, and when the second valve and the third valve are opened, the refrigerant stored in the receiver can move to the accumulator.

[0022] The heat pump according to the embodiment of the present invention may further include a controller for controlling the opening and closing of the first valve, the second valve, the third valve, and the fourth valve based on the amount of refrigerant during operation.

[0023] During the heating operation, if the degree of supercooling is higher than an upper limit reference value, the controller may control the first valve and the third valve to open and control the second valve and the fourth valve to close (close); during the heating operation, if the degree of supercooling is lower than a lower limit reference value, the controller may control the second valve and the third valve to open and control the first valve and the fourth valve to close (close).

[0024] During the refrigeration operation, if the degree of supercooling is higher than the upper limit reference value, the controller can control the fourth valve and the third valve to open and control the first valve and the second valve to close (close). During the refrigeration operation, if the degree of supercooling is lower than the lower limit reference value, the controller can control the second valve and the third valve to open and control the first valve and the fourth valve to close (close).

[0025] In the cooling operation, the controller can control the four-way valve so that the refrigerant discharged from the compressor is guided to the outdoor heat exchanger. In the heating operation, the controller can control the four-way valve so that the refrigerant discharged from the compressor is guided to the refrigerant-water heat exchanger.

[0026] The controller may control the first valve, the second valve, the third valve, and the fourth valve to be in a closed state during a set initial stabilization period.

[0027] The heat pump of the embodiment of the present invention may further include: a first pipe connecting the refrigerant-water heat exchanger and the expansion valve; and a second pipe branching from the first pipe and connected to the receiver, and the first valve may be arranged on the second pipe.

[0028] The expansion valve may include: a first expansion valve disposed between the refrigerant-water heat exchanger and the first valve; and a second expansion valve disposed between the outdoor heat exchanger and the second valve.

[0029] In heating operation, the first expansion valve may be opened to a maximum opening degree, and the second expansion valve may expand the refrigerant. In cooling operation, the first expansion valve may expand the refrigerant, and the second expansion valve may be opened to a maximum opening degree.

[0030] The heat pump of an embodiment of the present invention includes: a compressor; a liquid reservoir, which provides refrigerant to the compressor; a receiver, which is connected to the liquid reservoir; a refrigerant-water heat exchanger, which exchanges heat between the refrigerant and water; an outdoor heat exchanger, which exchanges heat between the refrigerant and outdoor air; a four-way valve, which guides the refrigerant discharged from the compressor to the refrigerant-water heat exchanger or the outdoor heat exchanger; a first expansion valve and a second expansion valve, which are arranged between the refrigerant-water heat exchanger and the outdoor heat exchanger; a first valve, which is arranged between the refrigerant-water heat exchanger and the receiver; a second valve, which is arranged between the compressor and the receiver; and a third valve, which is arranged between the receiver and the liquid reservoir, and the first valve is arranged in the piping connected between the first expansion valve and the second expansion valve.

[0031] The heat pump of an embodiment of the present invention includes: a compressor that compresses refrigerant; a liquid storage tank that provides refrigerant to the compressor; a receiver connected to the liquid storage tank; at least one indoor unit for cooling or heating, each including an indoor heat exchanger; an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air; a four-way valve that guides the refrigerant discharged from the compressor to the indoor unit or the outdoor heat exchanger; an expansion valve that is arranged between the indoor unit and the outdoor heat exchanger; a first valve that is arranged between the indoor unit and the receiver; a second valve that is arranged between the compressor and the receiver; and a third valve that is arranged between the receiver and the liquid storage tank.

[0032] In heating operation, the expansion valve can expand the refrigerant, and the expansion valve on the indoor unit side can be opened to a maximum opening degree. In cooling operation, the expansion valve can be opened to a maximum opening degree, and the expansion valve on the indoor unit side can expand the refrigerant.

[0033] The heat pump of an embodiment of the present invention includes: a compressor; a liquid reservoir, which provides refrigerant to the compressor; a receiver, which is connected to the liquid reservoir; an indoor heat exchanger, which exchanges heat between the refrigerant and water or indoor air; an outdoor heat exchanger, which exchanges heat between the refrigerant and outdoor air; a four-way valve, which guides the refrigerant discharged from the compressor to the indoor heat exchanger or the outdoor heat exchanger; an expansion valve, which is arranged between the indoor heat exchanger and the outdoor heat exchanger; a first valve, which is arranged between the indoor heat exchanger and the receiver; a second valve, which is arranged between the compressor and the receiver; a third valve, which is arranged between the receiver and the liquid reservoir; and a fourth valve, which is arranged between the outdoor heat exchanger and the receiver.

[0034] According to at least one embodiment of the present invention, the amount of refrigerant can be adjusted according to the operating state, so as to operate in an optimal refrigerant state.

[0035] According to at least one embodiment of the present invention, the amount of circulating refrigerant can be actively adjusted according to the required amount of refrigerant.

[0036] According to at least one embodiment of the present invention, a heat pump capable of improving performance and efficiency can be provided.

[0037] According to at least one embodiment of the present invention, even in cooling operation, refrigerant is not insufficient and the system can be operated with optimal performance and efficiency.

[0038] On the other hand, other effects will be disclosed directly or implicitly in the detailed description of the embodiments of the present invention to be described later. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a block diagram of a heat pump according to an embodiment of the present invention.

[0040] Figures 2 to 4 This is a diagram referred to in the description of the heat pump operation heating and the refrigerant flow according to one embodiment of the present invention.

[0041] Figures 5 to 7 This is a diagram referred to in the description of heat pump operation cooling and refrigerant flow in one embodiment of the present invention.

[0042] Figure 8 This is a flow chart of a heat pump operation method according to an embodiment of the present invention.

[0043] Fig. 9 It is a block diagram of a heat pump according to an embodiment of the present invention.

[0044] Fig.10 This is a diagram referred to in the description of the heat pump operation heating and the refrigerant flow according to one embodiment of the present invention.

[0045] Fig.11 This is a diagram referred to in the description of heat pump operation cooling and refrigerant flow in one embodiment of the present invention.

[0046] Fig.12 It is a block diagram of a heat pump according to an embodiment of the present invention.

[0047] Fig.13 It is a block diagram of a heat pump according to an embodiment of the present invention.

[0048] Description of Reference Numerals

[0049] Heat pump: 1

[0050] Expansion valve: 10

[0051] Compressor: 20

[0052] Outdoor heat exchanger: 50

[0053] Reservoir: 60

[0054] Receiver: 70 DETAILED DESCRIPTION

[0055] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments and can be modified in various forms.

[0056] In the drawings, in order to explain the present invention clearly and briefly, illustration of parts not related to the explanation is omitted, and the same reference numerals are used for the same or very similar parts throughout the specification.

[0057] On the other hand, the suffixes "module" and "unit" of the constituent elements used in the following description are only given for the convenience of writing this specification, and they themselves are not given particularly important meanings or functions. Therefore, the "module" and "unit" can also be used interchangeably.

[0058] In addition, in the present specification, in order to describe a plurality of elements, terms such as first and second may be used, but such elements are not limited to these terms. These terms are used only to distinguish one element from another element.

[0059] Figure 1 It is a block diagram of a heat pump according to an embodiment of the present invention.

[0060] Generally, a heat pump refers to a device that cools or heats a room through compression, condensation, expansion, and evaporation of a refrigerant. The heat pump 1 may include an outdoor unit and an indoor unit for forming a cycle, the outdoor unit may include an outdoor heat exchanger 50 disposed outdoors, and the indoor unit may include an indoor heat exchanger 40 disposed indoors.

[0061] The heat pump 1 of one embodiment of the present invention can use air and water as heat sources. In the heat pump 1 of the embodiment of the present invention, the refrigerant can perform heat exchange with outdoor air in the outdoor heat exchanger 50 and perform heat exchange with water in the indoor heat exchanger 40. Here, the refrigerant can apply a variety of refrigerants including R290.

[0062] The indoor heat exchanger 40 may be a refrigerant-water heat exchanger 40 that exchanges heat between the refrigerant and water. The heat transfer direction between the refrigerant and the water in the refrigerant-water heat exchanger 40 may be different according to the cooling and heating operation modes of the heat pump 1. In the refrigerant-water heat exchanger 40, the water that exchanges heat with the refrigerant may flow into the room and cool or heat the room, or provide cold water or hot water to the room.

[0063] The refrigerant-water heat exchanger 40 may be a plate-type heat exchanger. Here, the plate-type heat exchanger may have a plurality of electric heating plates stacked one on another, and the refrigerant and water flowing into the plate-type heat exchanger may flow along the flow path formed between the plurality of electric heating plates and perform heat exchange with each other in a non-contact manner.

[0064] As described above, the heat pump 1 according to an embodiment of the present invention is an air-to-water heat exchange type heat pump and can be referred to as an air source heat pump (AWHP).

[0065] Reference Figure 1The heat pump 1 includes: a compressor 20 that compresses refrigerant; a liquid storage tank 60 that provides refrigerant to the compressor 20; a refrigerant-water heat exchanger 40 that exchanges heat between the refrigerant and water; an outdoor heat exchanger 50 that exchanges heat between the refrigerant and outdoor air; a four-way valve 30 that guides the refrigerant discharged from the compressor 20 to the refrigerant-water heat exchanger 40 or the outdoor heat exchanger 50; and an expansion valve 10 that is arranged between the refrigerant-water heat exchanger 40 and the outdoor heat exchanger 50.

[0066] The compressor 20 can compress the refrigerant flowing in from the accumulator 60, and can be driven by a compressor motor (not shown). The compressor 20 can discharge high-temperature and high-pressure refrigerant by compressing the refrigerant flowing in from the accumulator 60. For example, the compressor 20 can be an inverter compressor that can control the amount of refrigerant and the discharge pressure of the refrigerant by adjusting the operating frequency.

[0067] The refrigerant compressed by the compressor 20 may flow into the outdoor heat exchanger 50 or the indoor heat exchanger 40 through the four-way valve 30 according to the cooling and heating operation modes of the heat pump 1 .

[0068] The outdoor heat exchanger 50 may allow the refrigerant to exchange heat with the outdoor air. The heat transfer direction between the refrigerant and the outdoor air in the outdoor heat exchanger 50 may be different depending on the cooling and heating operation modes of the heat pump 1.

[0069] The outdoor fan 50a can control the amount of air supplied to the outdoor heat exchanger 50 by being disposed at one side of the outdoor heat exchanger 50. The outdoor fan 50a can be driven by an outdoor fan motor (not shown).

[0070] The expansion valve 10 can receive the refrigerant condensed by either the outdoor heat exchanger 50 or the indoor heat exchanger 40 according to the cooling and heating operation mode of the heat pump 1. The expansion valve 10 can expand the condensed refrigerant. The refrigerant expanded by the expansion valve 10 can flow into the outdoor heat exchanger 50 or the indoor heat exchanger 40 according to the cooling and heating operation mode of the heat pump 1. The expansion valve 10 can be an electronic expansion valve (EEV).

[0071] The four-way valve 30 can selectively guide the refrigerant discharged from the compressor 20 to either the outdoor heat exchanger 50 or the indoor heat exchanger 40 according to the cooling and heating operation modes of the heat pump 1 .

[0072] When the controller 1310 described later cools the indoor environment, the four-way valve 30 can be adjusted so that the refrigerant discharged from the compressor 20 is guided to the outdoor heat exchanger 50. When the indoor environment is heated, the four-way valve 30 can be adjusted so that the refrigerant discharged from the compressor 20 is guided to the refrigerant-water heat exchanger 40.

[0073] The controller 1310 may be electrically connected to each component of the heat pump 1. The controller 1310 may control each component of the heat pump according to the operation mode of the heat pump. As described above, the heat pump 1 may supply cold water or hot water to the room according to the operation mode, and the cold water or hot water may be provided to the kitchen, toilet or bathroom, etc., or used for cooling or heating the room.

[0074] Generally, the heat exchanger of AWHP is composed of a fin-tube heat exchanger for heat exchange between air and refrigerant and a plate heat exchanger for heat exchange between refrigerant and water. When operating for heating, the high-temperature and high-pressure refrigerant flowing out of the compressor heats the water while passing through the plate heat exchanger, and the refrigerant is condensed to become liquid refrigerant, and then expanded into a low-temperature and low-pressure two-phase refrigerant in the expansion device, evaporated in the evaporator (Fin & Tube heat exchanger) and entered the compressor.

[0075] Since the internal volume of the plate heat exchanger used as a condenser in heating operation is smaller than that of the fin & tube heat exchanger, the optimal refrigerant amount is less than the refrigerant amount during cooling. When the refrigerant amount is too much, it will cause excessive increase in high pressure and decrease in efficiency.

[0076] Since the internal volume of the fin tube heat exchanger used as a condenser in refrigeration operation is large and the interior is filled with high-pressure liquid refrigerant, the required optimal refrigerant amount is large. When the refrigerant amount is small, insufficient supercooling due to insufficient refrigerant will occur in the condenser (Fin & Tube heat exchanger), and the refrigerant cannot flow sufficiently in the expansion device, resulting in insufficient refrigeration capacity.

[0077] Therefore, in AWHP, it is necessary to find and seal a suitable value between the optimum refrigerant amounts for cooling and heating, and it is not possible to use the optimum refrigerant amounts for cooling and heating at the same time.

[0078] Reference Figure 1 The heat pump 1 further includes a receiver 70 connected to the liquid reservoir 60. On the other hand, the receiver 70 can be separated from the liquid reservoir 60 and configured independently. Alternatively, the receiver 70 and the liquid reservoir 60 can also be formed as one body. As an example, the receiver 70 can be formed by dividing the upper part of the internal space of the liquid reservoir 60.

[0079] The receiver 70 stores refrigerant in excess of the refrigerant amount required by the heat exchangers 40 and 50. For example, when the refrigerant load or the heating load decreases, the required refrigerant amount is reduced, and as the required refrigerant amount decreases, a portion of the refrigerant is stored in the receiver 70. When the refrigerant load or the heating load increases, the required refrigerant amount increases, and as the required refrigerant amount increases, the refrigerant stored in the receiver 70 is discharged.

[0080] The heat pump 1 can actively store the refrigerant in the receiver 70 of the refrigerant storage device according to the required amount of refrigerant, or discharge the refrigerant stored in the receiver 70, so as to operate in an optimal refrigerant state after sealing in sufficient refrigerant.

[0081] That is, according to the present invention, the refrigerant can be sealed according to the refrigerant amount under the maximum demand and the refrigerant amount can be adjusted according to the operating state, thereby improving performance and efficiency. In particular, even during the refrigeration operation, the refrigerant is not insufficient and operates with optimal performance and efficiency.

[0082] In addition, the heat pump 1 can use a receiver 70 that stores refrigerant according to the required refrigerant amount and operate in an optimal refrigerant state corresponding to various operating modes and operating conditions, regardless of operating conditions such as indoor temperature, outdoor temperature, compressor frequency, and changes in operating modes such as cooling and heating.

[0083] A receiver 70 may be installed at the outlet of the heating reference condenser. In heating operation, since the refrigerant passes directly through the receiver after passing through the condenser (plate heat exchanger), liquid refrigerant can be stored in the receiver and the refrigerant exceeding the required amount during the heating process can be stored in the receiver in liquid form. In cooling operation, since the refrigerant passes through the receiver in a low-pressure two-phase refrigerant state after passing through the condenser and the expansion device, a large amount of liquid refrigerant is not stored in the receiver, so that the refrigerant required for cooling can be ensured.

[0084] However, when the receiver 70 is installed at the outlet of the heating reference condenser, it is not possible to accurately correspond to the required refrigerant amount according to various operating conditions such as the indoor temperature (water inlet temperature in the case of AWHP), the outdoor temperature, the compressor frequency, etc. In particular, in a multi-heat pump having a plurality of indoor units, since the optimal refrigerant amount varies depending on the number of indoor units in operation, the receiver 70 alone cannot achieve the optimal operation.

[0085] Therefore, the heat pump 1 of the present invention further includes a refrigerant quantity regulating valve ( Fig.13 The controller 1310 may adjust the refrigerant quantity by controlling the opening and closing of the refrigerant quantity regulating valve 1320.

[0086] According to one embodiment of the present invention, the refrigerant quantity regulating valve 1320 includes: a first valve V1, configured between the indoor heat exchanger 40 (for example, the refrigerant-water heat exchanger 40) and the receiver 70; a second valve V2, configured between the compressor 20 and the receiver 70; and a third valve V3, configured between the receiver 70 and the liquid storage tank 60.

[0087] According to an embodiment of the present invention, the refrigerant quantity regulating valve 1320 includes a fourth valve V4 disposed between the outdoor heat exchanger 50 and the receiver 70 .

[0088] Reference Figure 1 The refrigerant-side mechanical part of the heat pump 1 includes a compressor 20, a four-way valve 30, a refrigerant-water heat exchanger 40, an expansion valve 10, an outdoor heat exchanger 50, a liquid storage tank 60, and a receiver 70. The refrigerant exchanges heat with water in the refrigerant-water heat exchanger 40.

[0089] The controller 1310 controls the refrigerant flow direction according to whether cooling or heating is operated. The controller 1310 controls the four-way valve 30 according to whether cooling or heating is operated so that the refrigerant discharged from the compressor 20 is guided to the refrigerant-water heat exchanger 40 or the outdoor heat exchanger 50.

[0090] Figures 2 to 4 This is a diagram referred to in the description of the heat pump operation heating and the refrigerant flow according to one embodiment of the present invention. Figure 2 The refrigerant flow direction during heating operation is shown. Figure 3 The operation of the receiver 70 in the state of excess refrigerant is shown. Figure 4 The operation of the receiver 70 in a refrigerant-deficient state is shown.

[0091] The controller 1310 can adjust the amount of refrigerant according to the operating state by controlling the refrigerant amount regulating valve 1320 to store the refrigerant in the receiver 70 or discharge the refrigerant of the receiver 70. Thus, sufficient refrigerant that can meet the refrigerant amount in the case of maximum demand can be put into the heat pump 1. Therefore, even in the cooling operation, the refrigerant is not insufficient and the heat pump 1 operates with the best performance and efficiency.

[0092] In the heating operation, the controller 1310 controls the four-way valve 30 so that the refrigerant discharged from the compressor 20 is guided to the refrigerant-water heat exchanger 40 .

[0093] Reference Figure 2 In the heating operation, the refrigerant passes through the compressor 20, the four-way valve 30, the refrigerant-water heat exchanger 40, the expansion valve 10, the outdoor heat exchanger 50, the four-way valve 30, the accumulator 60 and then enters the compressor 20 again.

[0094] The low-temperature and low-pressure refrigerant flowing from the accumulator 60 into the compressor 20 can be discharged from the compressor 20 in a high-temperature and high-pressure state.

[0095] The refrigerant discharged from the compressor 20 may flow into the refrigerant-water heat exchanger 40 via the four-way valve 30, thereby exchanging heat with water. At this time, since heat energy is transferred from the refrigerant to the water, the temperature of the water increases and the refrigerant is condensed, so that in the heating operation, the refrigerant-water heat exchanger 40 can be understood as a condenser. At this time, the water with increased temperature is supplied to the room, thereby heating the indoor space. Alternatively, hot water may be supplied to the room.

[0096] The refrigerant passing through the refrigerant-water heat exchanger 40 may pass through the expansion valve 10 and be expanded to a low temperature and a low pressure.

[0097] The refrigerant passing through the expansion valve 10 can flow into the outdoor heat exchanger 50 and exchange heat with the outdoor air. At this time, since the heat energy of the outdoor air is transferred to the refrigerant, the temperature of the outdoor air is reduced and the refrigerant is evaporated, so that in the heating operation, the outdoor heat exchanger 50 can be understood as an evaporator.

[0098] The refrigerant passing through the outdoor heat exchanger 50 may flow into the accumulator 60 via the four-way valve 30. The accumulator 60 may supply the gaseous refrigerant to the compressor 20, thereby completing the heating cycle of the heat pump 1.

[0099] Reference Figure 3 When the first valve V1 and the third valve V3 are opened, a portion of the refrigerant passing through the refrigerant-water heat exchanger 40 moves to the receiver 70 and is stored.

[0100] In the case of heating operation, basically, since the amount of refrigerant in the heat pump 1 is large, it is stored in the receiver 70. When it is determined that the amount of refrigerant in the heating operation is large, the controller 1310 opens the first valve V1 and the third valve V3. In the heating operation, since the refrigerant flowing out of the refrigerant-water heat exchanger 40 is a high-pressure liquid refrigerant, the refrigerant moves to the receiver 70 through the first valve V1 and is stored.

[0101] The third valve V3 can play a role in making it easier for the refrigerant to enter the receiver 70 through the first valve V1. In addition, a capillary tube 90 can be configured at the rear end of the third valve V3. The capillary tube 90 can be configured between the third valve V3 and the liquid accumulator 60. The capillary tube 90 can limit the speed and amount of the refrigerant flowing into the receiver 70 or the refrigerant discharged. The capillary tube 90 is provided at the rear end of the third valve V3, and when the third valve V3 is opened, the liquid refrigerant can be prevented from directly entering the liquid accumulator 60.

[0102] When it is determined that the appropriate amount of refrigerant required for heating is reached, the controller 1310 closes the first valve V1 and the third valve V3 .

[0103] If the refrigerant is sealed based on the cooling operation, basically, the refrigerant excess state occurs more often. However, in the heating operation, since the optimal refrigerant amount also changes according to the outdoor temperature and the inlet water temperature in the refrigerant-water heat exchanger 40, the refrigerant amount is insufficient.

[0104] When it is determined that the amount of refrigerant in the heating operation is insufficient, the controller 1310 opens the second valve V2 and the third valve V3. Figure 4 , when the second valve V2 and the third valve V3 are opened, the refrigerant stored in the receiver 70 moves to the accumulator 60 and is applied to the refrigeration cycle again.

[0105] The controller 1310 opens the second valve V2 and the third valve V3 and transfers the refrigerant in the receiver 70 to the accumulator 60, thereby increasing the amount of circulating refrigerant. When the second valve V2 and the third valve V3 are opened, the high-pressure gas at the outlet of the compressor 20 pushes the liquid refrigerant in the receiver 70, causing the refrigerant to flow out through the third valve V3, and the inside of the receiver 70 is filled with gas, thereby increasing the amount of refrigerant moving in the product.

[0106] In the heating operation, the controller 1310 controls the opening and closing of the first valve V1 , the second valve V2 , and the third valve V3 based on the amount of refrigerant required corresponding to the heating load and the current amount of refrigerant.

[0107] When it is determined that the current amount of refrigerant is greater than the required amount of refrigerant, the controller 1310 opens the first valve V1 and the third valve V3 and stores the remaining refrigerant in the receiver 70 .

[0108] In addition, when it is determined that the current amount of refrigerant is less than the required amount of refrigerant, the controller 1310 opens the second valve V2 and the third valve V3 and discharges the refrigerant stored in the receiver 70, thereby increasing the amount of circulating refrigerant.

[0109] The excess / insufficient amount of refrigerant can be determined by using a variety of publicly available methods for determining the amount of refrigerant. For example, the excess / insufficient amount of refrigerant can be determined based on the degree of subcooling. An upper limit reference value and a lower limit reference value can be set for the degree of subcooling. When the degree of subcooling is higher than the upper limit reference value, it is determined that there is more refrigerant, and when the degree of subcooling is lower than the lower limit reference value, it is determined that there is less refrigerant. The upper limit reference value of the degree of subcooling and the lower limit reference value of the degree of subcooling can be set to an appropriate range of the degree of subcooling that can correspond to the heating load or the cooling load.

[0110] In cooling or heating operation, the amount of refrigerant can be confirmed by the degree of supercooling of the product. The controller 1310 can be based on the sensor (refer to Fig.13 The degree of supercooling is determined by using the data measured by the sensor 1330).

[0111] For example, the controller 1310 can determine the degree of supercooling of the refrigerant-water heat exchanger 40. The controller 1310 can measure the degree of supercooling of the refrigerant-water heat exchanger 40 based on the inlet temperature and outlet temperature of the refrigerant-water heat exchanger 40 detected by the temperature sensor. Alternatively, the controller 1310 can measure the degree of supercooling of the outdoor heat exchanger 50 based on the inlet temperature and outlet temperature of the outdoor heat exchanger 50 detected by the temperature sensor. In addition, in the case where the heat pump 1 also includes a supercooling device, the temperature of the pipe connected to the supercooling device can also be used to determine the degree of supercooling. In addition, the controller 1310 can compare the condensing temperature with the pipe temperature or the indoor unit outlet temperature according to whether the cooling or heating operation is performed, thereby determining the degree of supercooling.

[0112] When the supercooling degree is higher than the upper limit reference value, the controller 1310 may control the first valve V1 and the third valve V3 to open, and when the supercooling degree is lower than the lower limit reference value, the controller 1310 may control the second valve V2 and the third valve V3 to open.

[0113] In the heating operation, the controller 1310 may control the opening and closing of the first valve V1 , the second valve V2 , the third valve V3 , and the fourth valve V4 based on the amount of refrigerant required corresponding to the heating load and the current amount of refrigerant.

[0114] For example, in the heating operation, when the degree of supercooling is higher than the upper limit reference value, the controller 1310 may control the first valve V1 and the third valve V3 to be opened and control the second valve V2 and the fourth valve V4 to be closed.

[0115] In addition, in the heating operation, when the degree of supercooling is lower than the lower limit reference value, the controller 1310 may control the second valve V2 and the third valve V3 to be opened and control the first valve V1 and the fourth valve V4 to be closed.

[0116] Figures 5 to 7 This is a diagram referred to in the description of heat pump operation cooling and refrigerant flow in one embodiment of the present invention. Figure 5 Shows the refrigerant flow direction during cooling operation. Figure 6 The operation of the receiver 70 in the state of excess refrigerant is shown. Figure 7 The operation of the receiver 70 in a refrigerant-deficient state is shown.

[0117] In the heating operation, the controller 1310 controls the four-way valve 30 so that the refrigerant discharged from the compressor 20 is guided to the refrigerant-water heat exchanger 40 .

[0118] Furthermore, during the cooling operation, the controller 1310 controls the four-way valve 30 so that the refrigerant discharged from the compressor 20 is guided to the outdoor heat exchanger 50 .

[0119] Reference Figure 5 In cooling operation, the refrigerant passes through the compressor 20, the four-way valve 30, the outdoor heat exchanger 50, the expansion valve 10, the refrigerant-water heat exchanger 40, the four-way valve 30, the accumulator 60 and enters the compressor 20 again.

[0120] The low-temperature and low-pressure refrigerant flowing from the accumulator 60 into the compressor 20 can be discharged from the compressor 20 in a high-temperature and high-pressure state.

[0121] The refrigerant discharged from the compressor 20 may flow into the outdoor heat exchanger 50 through the four-way valve 30, thereby exchanging heat with the outdoor air. At this time, since heat energy is transferred from the refrigerant to the outdoor air, the temperature of the outdoor air increases and the refrigerant is condensed, so that in the cooling operation, the outdoor heat exchanger 50 can be understood as a condenser.

[0122] The refrigerant passing through the outdoor heat exchanger 50 may pass through the expansion valve 10 and expand to a low temperature and a low pressure.

[0123] The refrigerant passing through the expansion valve 10 may flow into the refrigerant-water heat exchanger 40, thereby exchanging heat with water. At this time, since the heat energy of the circulating water is transferred to the refrigerant, the temperature of the water is reduced and the refrigerant is evaporated, so in the refrigeration operation, the refrigerant-water heat exchanger 40 may be understood as an evaporator. At this time, the water with a reduced temperature may be supplied to the room, thereby cooling the indoor space. Alternatively, cold water is supplied to the room.

[0124] The refrigerant passing through the refrigerant-water heat exchanger 40 may pass through the four-way valve 30 and flow into the accumulator 60 .

[0125] The accumulator 60 may supply the gaseous refrigerant to the compressor 20 , thereby completing the refrigeration cycle of the heat pump 1 .

[0126] In the cooling operation, the controller 1310 may control the opening and closing of the first valve V1 , the second valve V2 , the third valve V3 , and the fourth valve V4 based on the amount of refrigerant required corresponding to the cooling load and the current amount of refrigerant.

[0127] In the cooling operation, when the degree of supercooling is higher than the upper limit reference value, the controller 1310 controls the fourth valve V4 and the third valve V3 to open and controls the first valve V1 and the second valve V2 to close.

[0128] Reference Figure 6When the fourth valve V4 and the third valve V3 are opened, a portion of the refrigerant passing through the outdoor heat exchanger 50 moves to the receiver 70 .

[0129] In the cooling operation, when the degree of supercooling is lower than the lower limit reference value, the controller 1310 controls the second valve V2 and the third valve V3 to open and controls the first valve V1 and the fourth valve V4 to close.

[0130] Reference Figure 7 , when the second valve V2 and the third valve V3 are opened, the refrigerant stored in the receiver 70 moves to the accumulator 60 .

[0131] If the refrigeration is operated in the state where the refrigerant is stored in the receiver 70, the actual amount of refrigerant will be less than the optimal amount of refrigerant required for refrigeration. At this time, the controller 1310 opens the second valve V2 and the third valve V3 and discharges the refrigerant stored in the receiver 70 to the accumulator 60. When the second valve V2 and the third valve V3 are opened, the high-pressure gas at the outlet of the compressor 20 pushes the liquid refrigerant in the receiver 70, so that the refrigerant flows out through the third valve V3, and the inside of the receiver 70 is filled with gas, thereby increasing the amount of refrigerant moving in the product.

[0132] At this time, the liquid refrigerant also expands through the capillary tube 90 at the rear end of the third valve V3 , and the refrigerant slowly moves to the accumulator 60 , thereby eliminating the risk of the liquid refrigerant directly flowing into the compressor 20 .

[0133] In the cooling operation, the optimal refrigerant amount may also change according to the outdoor temperature, the water inlet temperature, the compressor frequency, etc. In the cooling operation, if it is determined that the refrigerant amount is excessive, the controller 1310 opens the fourth valve V4 and the third valve V3 and stores the liquid refrigerant in the receiver 70. In the cooling operation, since the outlet of the outdoor heat exchanger 50 is a high-pressure liquid refrigerant, when the fourth valve V4 is opened, the liquid refrigerant is stored in the receiver 70.

[0134] During the operation of the product, the liquid storage tank 60 is in a low pressure state and has a low temperature, so it can play a role in keeping the temperature of the receiver 70 low.

[0135] Reference Figures 1 to 7 The expansion valve 10, the compressor 20, the four-way valve 30, the refrigerant-water heat exchanger 40, the outdoor heat exchanger 50, and the accumulator 60 may be connected to each other through a refrigerant pipe a.

[0136] The refrigerant-water heat exchanger 40 and the expansion valve 10 may be connected via the first pipe a1. The second pipe a2 may be branched from the first pipe a1 and connected to the receiver 70. A portion of the refrigerant flowing out of the refrigerant-water heat exchanger 40 may pass through the first pipe a1 and the second pipe a2 and move to the receiver 70. The first valve V1 may be disposed on the second pipe a2 to allow the refrigerant to flow into the receiver 70 or prevent the refrigerant from flowing in through the second pipe a2.

[0137] The third pipe a3 can provide a flow path of the refrigerant from the compressor 20 to the four-way valve 30 by being arranged between the compressor 20 and the four-way valve 30. The flow path can be switched according to the operation mode of the heat pump and the refrigerant flowing in through the third pipe a3 can be selectively guided to the refrigerant-water heat exchanger 40 or the outdoor heat exchanger 50.

[0138] The fourth pipe a4 may be branched from the third pipe a3 and connected to the receiver 70. In addition, the second valve V2 may be disposed in the fourth pipe a4. Thus, when the second valve V2 is opened, the high-pressure gas at the outlet of the compressor 20 pushes the liquid refrigerant in the receiver 70.

[0139] The fifth pipe a5 may be provided between the four-way valve 30 and the accumulator 60 to provide a flow path of the refrigerant to the four-way valve 30 and the accumulator 60. The accumulator 60 may supply the gaseous refrigerant to the compressor 20 through the sixth pipe a6.

[0140] The outdoor heat exchanger 50 and the expansion valve 10 may be connected via the seventh pipe a7. The twelfth pipe a12 may be branched from the seventh pipe a7 and connected to the receiver 70. A portion of the refrigerant flowing out of the outdoor heat exchanger 50 may move to the receiver 70 via the seventh pipe a7 and the twelfth pipe a12. The fourth valve V4 may be arranged on the twelfth pipe a12 to allow the refrigerant to flow into the receiver 70 or prevent the refrigerant from flowing in through the twelfth pipe a12.

[0141] On the other hand, the second pipe a2 and the fourth pipe a4 may be combined into a tenth pipe a10 and connected to the receiver 70. Alternatively, the second pipe a2 and the fourth pipe a4 may be directly connected to the receiver 70, respectively.

[0142] The twelfth pipe a12 may be combined with the second pipe a2 or the tenth pipe a10 . Alternatively, the twelfth pipe a12 may be directly connected to the receiver 70 .

[0143] When the flow path for the refrigerant to flow into the receiver 70 is formed as one tenth pipe a10 , there is an advantage that only one interface for the refrigerant to flow into the receiver 70 needs to be provided.

[0144] On the other hand, the receiver 70 and the reservoir 60 may be connected via the eleventh pipe a11. The third valve V3 may be disposed in the eleventh pipe a11. In addition, the capillary tube 90 may be disposed in the eleventh pipe a11.

[0145] On the other hand, the pump 80 and the refrigerant-water heat exchanger 40 can be connected through the water pipe b. In addition, the pump 80 and the refrigerant-water heat exchanger 40 can be connected to a water tank (not shown), a water supply source, etc. through the water pipe b. Water can flow into the refrigerant-water heat exchanger 40 through the water inlet pipe b1, and the water that undergoes heat exchange in the refrigerant-water heat exchanger 40 can be discharged to the water tank, indoor space, etc. through the water outlet pipe b2.

[0146] Figure 8 This is a flow chart of a heat pump operation method according to an embodiment of the present invention.

[0147] Reference Figure 8 During the initial stabilization period, after the heat pump 1 is operated (S810), the refrigerant quantity adjustment control logic (S820) can be executed. For example, the controller 1310 controls to execute the initial operation for five minutes (S810). At this time, the controller 1310 can control the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4 to be closed during the set initial stabilization period (S815).

[0148] The controller 1310 may determine whether to operate the cooling or heating mode ( S820 ), and determine whether the refrigerant is excessive or insufficient based on reference values ​​set for each operation ( S825 , S835 , S850 , S860 ).

[0149] Although Figure 8 , the upper limit reference value and the lower limit reference value of the cooling operation are set to be the same as the upper limit reference value and the lower limit reference value of the heating operation, but the present invention is not limited thereto. For example, the amount of refrigerant may be judged to be more or less with different references depending on the cooling operation or the heating operation. In addition, the upper limit reference value and the lower limit reference value may be set to be different in the cooling operation and the heating operation.

[0150] When the degree of supercooling exceeds the upper limit reference value (e.g., 20° C.) (S825), the controller 1310 determines that the refrigerant is excessive, and performs an operation of storing liquid refrigerant in the receiver 70 (S830). At this time, the controller 1310 controls the first valve V1 and the third valve V3 to open and controls the second valve V2 and the fourth valve V4 to close.

[0151] When the degree of supercooling is lower than the lower limit reference value (e.g., 5°C) (S835), the controller 1310 determines that the refrigerant is too little, and performs an operation of discharging the liquid refrigerant from the receiver 70 (S845). At this time, the controller 1310 controls the second valve V2 and the third valve V3 to open and controls the first valve V1 and the fourth valve V4 to close.

[0152] On the other hand, during heating operation, when the degree of supercooling is within the range of the upper limit reference value and the lower limit reference value (for example, within 5°C to 20°C), the controller 1310 can determine that the refrigerant is appropriate and can control the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4 to a closed state (S840).

[0153] In the cooling operation, when the degree of supercooling exceeds the upper limit reference value (e.g., 20° C.) (S850), the controller 1310 determines that there is too much refrigerant, and performs an operation (S855) of storing liquid refrigerant in the receiver 70. At this time, the controller 1310 controls the third valve V3 and the fourth valve V4 to open and controls the first valve V1 and the second valve V2 to close.

[0154] In the cooling operation, when the degree of supercooling is lower than the lower limit reference value (e.g., 5°C) (S860), the controller 1310 determines that the refrigerant is too little, and performs an operation of discharging the liquid refrigerant from the receiver 70 (S870). At this time, the controller 1310 controls the second valve V2 and the third valve V3 to open and controls the first valve V1 and the fourth valve V4 to close.

[0155] On the other hand, during refrigeration operation, when the degree of supercooling is within the range of the upper limit reference value and the lower limit reference value (for example, within 5°C to 20°C), the controller 1310 can determine that the refrigerant is appropriate and can control the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4 to be in a closed state (S865).

[0156] According to one embodiment of the present invention, the refrigerant quantity regulation control for storing or discharging liquid refrigerant according to the degree of supercooling can be repeatedly performed in the following manner: after controlling the refrigerant quantity regulating valve 1320 for ten seconds, all refrigerant quantity regulating valves 1320 are closed for five minutes, the degree of supercooling is confirmed while the system is running, and then, it is controlled again for ten seconds.

[0157] The refrigerant quantity regulating valve 1320 for supercooling adjustment is opened (on) for ten seconds and then closed. After that, the supercooling state is confirmed by five minutes of system operation, and the refrigerant quantity regulating valve 1320 is controlled to be opened (On) or closed (Off) again. Thus, the refrigerant quantity adjustment control can be performed in a manner of monitoring while controlling for ten seconds and operating for five minutes.

[0158] Fig. 9 It is a block diagram of a heat pump according to an embodiment of the present invention.

[0159] Fig.10 This is a diagram for reference in the description of the heat pump operation heating and the refrigerant flow in one embodiment of the present invention. Fig.11 This is a diagram referred to in the description of heat pump operation cooling and refrigerant flow in one embodiment of the present invention.

[0160] Due to the use of the subcooler and the use of the injection module during the cooling and heating process, the heat pump 1 of an embodiment of the present invention can use two expansion devices. For example, the injection module can inject a portion of the flowing refrigerant into the compressor 20. Here, injection can refer to causing a refrigerant having an intermediate pressure between the pressure of the refrigerant flowing from the accumulator 60 into the compressor 20 and the pressure of the refrigerant discharged from the compressor 20 to flow into the compression chamber of the compressor 20. The injection module can have an expansion valve that expands a portion of the refrigerant.

[0161] Reference Fig. 9 The expansion valve 10 includes: a first expansion valve 10a, which is arranged between the refrigerant-water heat exchanger 40 and the first valve V1; and a second expansion valve 10b, which is arranged between the outdoor heat exchanger 50 and the first valve V1.

[0162] In this embodiment, the refrigerant quantity regulating valve 1320 includes a first valve V1, a second valve V2, and a third valve V3.

[0163] The first valve V1 may transfer the refrigerant flowing in from any direction to the receiver 70 by being disposed between the first expansion valve 10 a and the second expansion valve 10 b .

[0164] The first valve V1 may be disposed on the thirteenth pipe a13 connecting the first expansion valve 10a and the second expansion valve 10b. The first expansion valve 10a and the second expansion valve 10b may be connected via the fourteenth pipe a14. The thirteenth pipe a13 may be branched from the fourteenth pipe a14 and connected to the receiver 70. The first valve V1 may allow the refrigerant to flow into the receiver 70 or prevent the refrigerant from flowing in by being disposed on the thirteenth pipe a13.

[0165] The other components except the first expansion valve 10a, the second expansion valve 10b, the thirteenth pipe a13, and the fourteenth pipe a14 are the same as Figures 1 to 7 Therefore, Figures 9 to 11 Embodiments and Figures 1 to 7 Repeated parts in the embodiments are briefly described or their description is omitted, but it is obvious that they can be applied in the same manner.

[0166] In the heating operation, the controller 1310 controls the four-way valve 30 so that the refrigerant discharged from the compressor 20 is guided to the refrigerant-water heat exchanger 40 .

[0167] Reference Fig.10 In heating operation, the refrigerant passes through the compressor 20, the four-way valve 30, the refrigerant-water heat exchanger 40, the first expansion valve 10a, the second expansion valve 10b, the outdoor heat exchanger 50, the four-way valve 30, the accumulator 60 and enters the compressor 20 again.

[0168] The first expansion valve 10a and the second expansion valve 10b may be electronic expansion valves (EEV) capable of adjusting the opening degree. The first expansion valve 10a and the second expansion valve 10b may adjust the opening degree according to the cooling or heating operation mode.

[0169] During heating operation, the first expansion valve 10a can be fully opened and the second expansion valve 10b can be partially opened, so that the refrigerant passing through the refrigerant-water heat exchanger 40 can pass through the first expansion valve 10a without state change and flow into the outdoor heat exchanger 50 after being expanded when passing through the second expansion valve 10b.

[0170] On the other hand, when the amount of refrigerant is within the reference range, the controller 1310 keeps the first valve V1 , the second valve V2 , and the third valve V3 in a closed state.

[0171] When it is determined that the refrigerant is more than the required amount, the controller 1310 opens the first valve V1 and the third valve V3 and stores a portion of the refrigerant in the receiver 70. When the amount of refrigerant is reduced to meet the reference range, the controller 1310 closes the first valve V1 and the third valve V3.

[0172] When it is determined that the refrigerant is less than the required amount, the controller 1310 opens the second valve V2 and the third valve V3 and discharges the refrigerant stored in the receiver 70 to the accumulator 60. When the refrigerant amount is increased to meet the reference range, the controller 1310 closes the second valve V2 and the third valve V3.

[0173] In the cooling operation, the controller 1310 controls the four-way valve 30 so that the refrigerant discharged from the compressor 20 is guided to the outdoor heat exchanger 50 .

[0174] Reference Fig.11 In cooling operation, the refrigerant passes through the compressor 20, the four-way valve 30, the outdoor heat exchanger 50, the expansion valve 10, the refrigerant-water heat exchanger 40, the four-way valve 30, the accumulator 60 and enters the compressor 20 again.

[0175] During cooling operation, the second expansion valve 10b is fully opened and the first expansion valve 10a is partially opened, so that the refrigerant passing through the refrigerant-water heat exchanger 40 can pass through the second expansion valve 10b without state change and flow into the outdoor heat exchanger 50 after being expanded when passing through the first expansion valve 10a.

[0176] In cooling operation, when it is determined that the refrigerant is greater than the required amount, the controller 1310 opens the first valve V1 and the third valve V3 and stores a portion of the refrigerant in the receiver 70. When the amount of refrigerant is reduced to meet the reference range, the controller 1310 closes the first valve V1 and the third valve V3.

[0177] In cooling operation, when it is determined that the refrigerant is less than the required amount, the controller 1310 opens the second valve V2 and the third valve V3 and discharges the refrigerant stored in the receiver 70 to the accumulator 60. When the amount of refrigerant is increased to meet the reference range, the controller 1310 closes the second valve V2 and the third valve V3.

[0178] Fig.12 It is a block diagram of a heat pump according to an embodiment of the present invention.

[0179] Reference Fig.12 The heat pump 1 includes: a compressor 20; a liquid storage tank 60, which provides refrigerant to the compressor 20; a receiver 70, which is connected to the liquid storage tank 60; at least one indoor unit I1, I2 for cooling or heating, each including an indoor heat exchanger; an outdoor heat exchanger 50, which allows the refrigerant to exchange heat with outdoor air; a four-way valve 30, which guides the refrigerant discharged from the compressor 20 to the indoor unit I1, I2 or the outdoor heat exchanger 50; an expansion valve 10, which is arranged between the indoor unit I1, I2 and the outdoor heat exchanger 50; a first valve V1, which is arranged between the indoor unit I1, I2 and the receiver 70; a second valve V2, which is arranged between the compressor 20 and the receiver 70; and a third valve V3, which is arranged between the receiver 70 and the liquid storage tank 60.

[0180] Reference Fig.12 The heat pump 1 may be a multi-heat pump in which a plurality of indoor units I1 and I2 are connected to an outdoor heat exchanger 50 and expansion devices E1 and E2 are provided in the indoor units I1 and I2, respectively.

[0181] The indoor units I1 and I2 and the expansion valve 10 may be connected via a first pipe a1. A second pipe a2 may be branched from the first pipe a1 and connected to the receiver 70. In addition, the expansion valve 10 may be connected to the outdoor heat exchanger 50 via a seventh pipe a7.

[0182] The refrigerant may flow into the receiver 70 via the first pipe a1 and the second pipe a2, or may flow into the receiver 70 via the seventh pipe a7, the first pipe a1, and the second pipe a2.

[0183] On the other hand, the first pipe a1 may be connected to the indoor units I1 and I2. The first pipe a1 may be connected to the first indoor unit I1 through the 1-1 indoor unit pipe a21, and may be connected to the second indoor unit I2 through the 2-1 indoor unit pipe a22.

[0184] The first indoor expansion valve E1 is arranged on the 1-1 indoor unit pipe a21, and the second indoor expansion valve E2 is arranged on the 2-1 indoor unit pipe a22. The indoor units I1 and I2 include: an indoor heat exchanger for exchanging heat between the refrigerant and the indoor air; an indoor fan (not shown) for generating air flow; and indoor expansion valves E1 and E2 for expanding the refrigerant. The indoor expansion valves E1 and E2 may be electronic expansion valves (EEV). The refrigerant may be expanded by the outdoor expansion valve 10 or the indoor expansion valves E1 and E2.

[0185] In addition, the ninth pipe a9 may be connected to the indoor units I1 and I2. The ninth pipe a9 is connected to the first indoor unit I1 through the 1st-2nd indoor unit pipe a23, and is connected to the second indoor unit I2 through the 2nd-2nd indoor unit pipe a24.

[0186] Other components other than those related to indoor units I1 and I2 Figures 1 to 7 Therefore, Fig.12 Examples and Figures 1 to 7 Repeated parts in the embodiments are briefly described or their description is omitted, but it is obvious that they can be applied in the same manner.

[0187] During the heating operation, the controller 1310 controls the four-way valve 30 so that the refrigerant discharged from the compressor 20 is guided to the indoor units I1 and I2 in the heating operation. During the cooling operation, the controller 1310 controls the four-way valve 30 so that the refrigerant discharged from the compressor 20 is guided to the outdoor heat exchanger 50.

[0188] In the heating operation, the refrigerant passes through the compressor 20 , the four-way valve 30 , the indoor units I1 , I2 , the expansion valve 10 , the outdoor heat exchanger 50 , the four-way valve 30 , and the accumulator 60 and enters the compressor 20 again.

[0189] In the cooling operation, the refrigerant passes through the compressor 20 , the four-way valve 30 , the outdoor heat exchanger 50 , the expansion valve 10 , the indoor units I1 , I2 , the four-way valve 30 , and the accumulator 60 and enters the compressor 20 again.

[0190] On the other hand, in the heating operation, the expansion valve 10 expands the refrigerant, and the expansion valves E1 and E2 on the indoor units I1 and I2 are opened to the maximum opening. In the cooling operation, the expansion valve 10 is opened to the maximum opening, and the expansion valves E1 and E2 on the indoor units I1 and I2 are expanded.

[0191] The expansion valve 10 and the indoor expansion valves E1 and E2 may be electronic expansion valves (EEVs) capable of adjusting the opening degree. The expansion valve 10 and the indoor expansion valves E1 and E2 may adjust the opening degree according to the cooling or heating operation mode.

[0192] During heating operation, the indoor expansion valves E1 and E2 are fully opened and the expansion valve 10 is partially opened, so that the refrigerant passing through the heat exchangers on the indoor units I1 and I2 sides can pass through the indoor expansion valves E1 and E2 without changing its state and expand when passing through the expansion valve 10 and then flow into the outdoor heat exchanger 50.

[0193] During cooling operation, the expansion valve 10 is fully opened and the indoor expansion valves E1 and E2 are partially opened, so that the refrigerant passing through the outdoor heat exchanger 50 can pass through the expansion valve 10 without changing its state and expand when passing through the indoor expansion valves E1 and E2 and then flow into the heat exchangers on the indoor units I1 and I2 sides.

[0194] On the other hand, when the amount of refrigerant is within the reference range, the controller 1310 keeps the first valve V1 , the second valve V2 , and the third valve V3 in a closed state.

[0195] When it is determined that the refrigerant is more than the required amount, the controller 1310 opens the first valve V1 and the third valve V3 and stores a portion of the refrigerant in the receiver 70. When the amount of refrigerant is reduced to meet the reference range, the controller 1310 closes the first valve V1 and the third valve V3.

[0196] When it is determined that the refrigerant is less than the required amount, the controller 1310 opens the second valve V2 and the third valve V3 and discharges the refrigerant stored in the receiver 70 to the accumulator 60. When the refrigerant amount is increased to meet the reference range, the controller 1310 closes the second valve V2 and the third valve V3.

[0197] According to the present invention, in products such as multi-heat pumps or AWHPs where the optimum refrigerant amount varies significantly depending on the number of indoor units in operation or the cooling or heating operation mode, it is possible to operate in an optimum refrigerant state according to the operating state by using a receiver 70 that can store refrigerant.

[0198] Fig.13 It is a block diagram of a heat pump according to an embodiment of the present invention.

[0199] Reference Fig.13 A heat pump 1 according to an embodiment of the present invention includes the above-mentioned compressor 20 , four-way valve 30 , and expansion valve 10 .

[0200] In addition, the heat pump 1 includes a refrigerant quantity regulating valve 1320 for regulating the amount of circulating refrigerant. For example, the refrigerant quantity regulating valve 1320 may be configured as follows: Figure 1 Alternatively, the refrigerant quantity regulating valve 1320 may be composed of the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4 described in the above description. Fig. 9 , Fig.12 The first valve V1, the second valve V2, and the third valve V3 described above are constituted.

[0201] In addition, the heat pump 1 further includes a controller 1310 for controlling the overall operation. The controller 1310 can control the four-way valve 30 according to the operation mode of cooling operation or heating operation, thereby adjusting the flow direction of the refrigerant.

[0202] In addition, the controller 1310 may adjust the opening of the expansion valve 10 , and for this purpose, the expansion valve 10 may be an electronic expansion valve (EEV).

[0203] In addition, the controller 1310 may store the refrigerant in the receiver 70 or circulate the refrigerant stored in the receiver 70 by controlling the opening and closing of the refrigerant amount regulating valve 1320 .

[0204] In addition, the controller 1310 may receive data measured from the sensor of the sensing part 1330 and control the heat pump 1 based on the received data.

[0205] The sensor unit 1330 has a plurality of sensors. For example, the sensor unit 1330 can obtain indoor and outdoor temperature and humidity data by setting an outdoor temperature sensor, an outdoor humidity sensor, an indoor temperature sensor, an indoor humidity sensor, etc.

[0206] For example, in order to measure the compressor discharge superheat, the sensor unit 1330 may include a compressor outlet temperature sensor and an indoor heat exchanger pressure sensor.

[0207] The compressor discharge superheat can be measured based on the compressor discharge temperature measured by the compressor outlet temperature sensor provided at the outlet side of the compressor 20 and the saturation temperature of the refrigerant condensed in the indoor heat exchanger 40, and the saturation temperature of the refrigerant condensed in the indoor heat exchanger 40 can be obtained by converting the saturation pressure of the refrigerant condensed in the indoor heat exchanger 40 measured by the indoor heat exchanger pressure sensor provided at the indoor heat exchanger 40. Alternatively, the saturation temperature of the refrigerant condensed in the indoor heat exchanger 40 can be directly measured by providing the indoor heat exchanger temperature sensor in the indoor heat exchanger 40.

[0208] When the compressor discharge temperature is higher than the reference discharge temperature, the controller 1310 may increase the amount of refrigerant to reduce the compressor discharge temperature.

[0209] For example, in order to measure the suction superheat, the sensing unit 1330 may have a compressor inlet temperature sensor and an outdoor heat exchanger pressure sensor. The suction superheat may be measured based on the compressor suction temperature measured by the compressor inlet temperature sensor provided at the inlet side of the compressor 20 and the saturation temperature of the refrigerant evaporated in the outdoor heat exchanger 50, and the saturation temperature of the refrigerant evaporated in the outdoor heat exchanger 50 may be obtained by converting the saturation pressure of the refrigerant evaporated in the outdoor heat exchanger 50 measured by the outdoor heat exchanger pressure sensor provided at the outdoor heat exchanger 50. Alternatively, according to an embodiment, the saturation temperature of the refrigerant evaporated in the outdoor heat exchanger 50 may also be directly measured by providing an outdoor heat exchanger temperature sensor in the outdoor heat exchanger 50.

[0210] When the suction superheat exceeds the reference temperature value, the controller 1310 may increase the amount of refrigerant passing through the outdoor heat exchanger 50 to reduce the suction superheat.

[0211] The heat pump 1 includes a compressor 20 , an expansion valve 10 , a four-way valve 30 , an outdoor heat exchanger 50 , one or more heat exchangers 40 for heat supply, a liquid storage tank 60 , and a receiver 70 .

[0212] According to one embodiment of the present invention, the heat pump 1 includes: a second valve V2, connected from the outlet of the compressor 20 to the receiver 70; a fourth valve V4, connected from the outlet of the cooling operation reference condenser (outdoor heat exchanger 50) to the receiver 70; a first valve V1, connected from the outlet of the heating reference condenser (indoor heat exchanger or refrigerant-water heat exchanger) to the receiver 70; and a third valve V3, connected between the receiver 70 and the liquid storage tank 60.

[0213] In addition, the heat pump 1 may further include a capillary tube 90 between the third valve V3 and the liquid reservoir 60 .

[0214] When the degree of subcooling of the heat pump system is confirmed and the degree of subcooling is greater than a reference value (eg, 20° C.), the controller 1310 may determine that there is too much refrigerant and perform an operation of storing the refrigerant in the receiver 70 .

[0215] In addition, when the degree of supercooling is less than a reference value (eg, 5° C.), the controller 1310 determines that the amount of refrigerant is too small and performs an operation of discharging the liquid refrigerant of the receiver 70 to the accumulator 60 .

[0216] like Figures 9 to 11 In the embodiment shown, since two or more expansion devices are provided, the fourth valve V4 can be deleted if one side can ensure the subcooled liquid regardless of cooling and heating.

[0217] According to an embodiment, the reservoir 60 may be adjacent to the receiver 70 and constituted as one body. Alternatively, the reservoir 60 and the receiver 70 may also be constituted by separate bodies.

[0218] In order to solve the above problem, the heat pump according to the embodiment of the present invention can actively store the refrigerant in the refrigerant storage device or discharge the refrigerant stored in the refrigerant storage device according to the required amount of refrigerant, thereby operating in an optimal refrigerant state.

[0219] In order to solve the above problems, the heat pump according to the embodiment of the present invention can operate in the optimal refrigerant state regardless of operating conditions such as indoor temperature, outdoor temperature, compressor frequency, and operating modes such as cooling and heating by using a device that can store refrigerant according to the required refrigerant amount.

[0220] In order to solve the above problems, the heat pump of the embodiment of the present invention can seal the refrigerant according to the refrigerant amount under the maximum demand and adjust the refrigerant amount according to the operating state, thereby improving performance and efficiency. In particular, even in cooling operation, the refrigerant will not be insufficient and the heat pump can operate with optimal performance and efficiency.

[0221] In order to solve the above-mentioned problem, the heat pump of an embodiment of the present invention actively adjusts the amount of circulating refrigerant, so that even in products such as multi-heat pumps or AWHPs where the optimal amount of refrigerant varies significantly depending on the number of indoor units in operation or the cooling and heating operation modes, it can operate in the optimal refrigerant state according to the operating state.

[0222] Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-mentioned specific embodiments, and a person skilled in the art may make various modifications within the scope of the present invention as claimed in the claims, and these modifications should not be understood separately from the technical idea or prospect of the present invention.

Claims

1. A heat pump, wherein: include: compressor, which compresses the refrigerant; a liquid receiver for supplying refrigerant to the compressor; a receiver connected to the liquid reservoir; Refrigerant-water heat exchanger, which exchanges heat between refrigerant and water; An outdoor heat exchanger exchanges heat between the refrigerant and the outdoor air; A four-way valve guides the refrigerant discharged from the compressor to the refrigerant-water heat exchanger or the outdoor heat exchanger; an expansion valve, disposed between the refrigerant-water heat exchanger and the outdoor heat exchanger; a first valve disposed between the refrigerant-water heat exchanger and the receiver; a second valve disposed between the compressor and the receiver; as well as The third valve is arranged between the receiver and the liquid reservoir.

2. The heat pump according to claim 1, wherein: During heating operation, When the first valve and the third valve are opened, a portion of the refrigerant passing through the refrigerant-water heat exchanger moves to the receiver, When the second valve and the third valve are opened, the refrigerant stored in the receiver moves to the accumulator.

3. The heat pump according to claim 2, wherein: The system further includes a controller that controls the opening and closing of the first valve, the second valve, and the third valve based on the amount of refrigerant during operation.

4. The heat pump according to claim 3, wherein: In the heating operation, if the degree of supercooling is higher than an upper limit reference value, the controller controls the first valve and the third valve to open. In the heating operation, if the degree of supercooling is lower than a lower limit reference value, the controller controls the second valve and the third valve to open.

5. The heat pump according to claim 3, wherein: During the heating operation, the controller controls the four-way valve so that the refrigerant discharged from the compressor is guided to the refrigerant-water heat exchanger.

6. The heat pump according to claim 1, wherein: A capillary tube is also included, and the capillary tube is configured between the third valve and the liquid reservoir.

7. The heat pump according to claim 1, wherein: The device further includes a fourth valve, which is disposed between the outdoor heat exchanger and the receiver.

8. The heat pump according to claim 7, wherein: During refrigeration operation, When the fourth valve and the third valve are opened, a portion of the refrigerant passing through the outdoor heat exchanger moves to the receiver. When the second valve and the third valve are opened, the refrigerant stored in the receiver moves to the accumulator.

9. The heat pump according to claim 8, wherein: The system further includes a controller that controls the opening and closing of the first valve, the second valve, the third valve, and the fourth valve based on the amount of refrigerant during operation.

10. The heat pump according to claim 9, wherein: In the heating operation, if the degree of supercooling is higher than the upper limit reference value, the controller controls the first valve and the third valve to open and controls the second valve and the fourth valve to close. In the heating operation, if the degree of supercooling is lower than a lower limit reference value, the controller controls the second valve and the third valve to be opened, and controls the first valve and the fourth valve to be closed.

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