Heat pump system for a vehicle

Abstract

The present invention discloses a heat pump system for a vehicle, which can control the temperature of a battery module by using a refrigerator that exchanges heat between a refrigerant and a coolant; and can maximize the cooling and heating performance by applying a gas injection device that selectively operates in the cooling, heating, or dehumidifying mode of the vehicle to increase the flow rate of the refrigerant.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10 - 2020 - 0172334, filed on December 10, 2020, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] The present disclosure relates to a heat pump system for a vehicle. More specifically, the present disclosure relates to a heat pump system for a vehicle that regulates the temperature of a battery module by using a chiller that exchanges heat between a refrigerant and a coolant and improves heating performance by applying a gas injection device. Background Art

[0004] Generally, an air - conditioning system for a vehicle includes an air - conditioning device that circulates a refrigerant to heat or cool the vehicle interior.

[0005] Such an air - conditioning device maintains a comfortable interior environment by keeping the temperature of the vehicle interior at an appropriate level regardless of external temperature changes. During the process in which the refrigerant discharged by driving a compressor passes through a condenser, a liquid receiver dryer, an expansion valve, and an evaporator and then circulates back to the compressor again, heat exchange is performed through the condenser and the evaporator to heat or cool the vehicle interior.

[0006] That is, in the cooling mode in summer, the air - conditioning device condenses the high - temperature and high - pressure gaseous coolant compressed by the compressor, and then passes through the liquid receiver dryer and the expansion valve to reduce the temperature and humidity of the interior by evaporating in the evaporator.

[0007] Meanwhile, in recent years, as concerns about energy efficiency and environmental pollution have gradually increased, there has been a need to develop environmentally friendly vehicles to substantially replace internal combustion engine vehicles. Environmentally friendly vehicles are generally electric vehicles driven by fuel cells or electricity, or hybrid vehicles driven by an engine and a battery.

[0008] Unlike the air - conditioning device of a general vehicle, in an environmentally friendly vehicle, an electric vehicle or a hybrid vehicle does not use a separate heater, and the air - conditioning device applied to an environmentally friendly vehicle is generally referred to as a heat pump system.

[0009] On the other hand, in the case of an electric vehicle, the chemical reaction energy of oxygen and hydrogen is converted into electrical energy to generate a driving force. In this process, since heat is generated due to the chemical reaction in the fuel cell, in order to ensure the performance of the fuel cell, the generated heat must be effectively removed.

[0010] In addition, even in a hybrid vehicle, the driving force is generated by jointly driving a motor with the electric power supplied by a fuel cell or a battery and an engine that runs on ordinary fuel. Therefore, only by effectively removing the heat generated by the fuel cell or the battery and the motor can the performance of the motor be ensured.

[0011] Therefore, generally in a hybrid vehicle or an electric vehicle, a battery cooling system, a cooler, and a heat pump system need to form separate closed loops separately to prevent heat generation by the motor, electrical components, and the battery including the fuel cell.

[0012] Accordingly, the size and weight of the cooling module provided at the front of the vehicle increase, and in the engine compartment, the layout of the connecting pipes for supplying the refrigerant and the coolant to the heat pump system, the cooler, and the battery cooling system is complicated.

[0013] In addition, a battery cooling system that heats or cools the battery according to the state of the vehicle is separately provided to enable the battery to exhibit optimal performance. Therefore, a plurality of valves connected to the respective connecting pipes are applied, and the noise and vibration caused by the frequent opening and closing operations of the valves are transmitted into the vehicle interior, resulting in deteriorated riding comfort.

[0014] In addition, when heating the vehicle interior, the heating performance decreases due to the lack of a heat source, the power consumption increases due to the use of an electric heater, and the power consumption of the compressor increases.

[0015] The information included in the background section of the present invention is only used to enhance the understanding of the overall background of the present invention, and cannot be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0016] Aspects of the present invention aim to provide a heat pump system for a vehicle that can control the temperature of a battery module by using a single refrigerator that exchanges heat between a refrigerant and a coolant to simplify the system.

[0017] In addition, aspects of the present invention aim to provide a heat pump system for a vehicle that can increase the flow rate of the refrigerant by applying a gas injection device that selectively operates in the cooling, heating, or dehumidifying mode of the vehicle, thereby maximizing the cooling and heating performance.

[0018] Aspects of the present invention are directed to providing a heat pump system for a vehicle, including: an air conditioning device that circulates a refrigerant through a refrigerant pipeline; a coolant circulation device that circulates a coolant through a coolant pipeline; a refrigerator that is connected to the coolant circulation device through a coolant pipeline, is connected to the refrigerant pipeline through a refrigerant connection pipeline that is part of the refrigerant pipeline, and controls the temperature of the selectively flowing coolant by exchanging heat between the coolant selectively flowing in from the coolant circulation device and the refrigerant supplied from the air conditioning device; and a gas injection device that is provided in the air conditioning device and increases the flow rate of the refrigerant circulating in the refrigerant pipeline by bypassing a part of the refrigerant in the refrigerant passing through an internal condenser connected to the refrigerant pipeline to the compressor, wherein a heat exchanger provided in the air conditioning device is connected to the coolant circulation device through a coolant pipeline so that the coolant is supplied from the coolant circulation device, and the heat pump system further includes a first branch pipeline that is connected to the refrigerant pipeline through a first refrigerant valve at the rear end of the heat exchanger based on the flow direction of the refrigerant.

[0019] The air conditioning device may include: a heating, ventilation, and air conditioning (HVAC) module including an evaporator connected through a refrigerant pipeline and an opening and closing door configured to selectively allow outside air passing through the evaporator to flow into an internal condenser according to cooling, heating, and dehumidifying modes of the vehicle; a heat exchanger connected to the refrigerant pipeline and the coolant pipeline and exchanging heat between the refrigerant supplied through the refrigerant pipeline and the coolant supplied from the coolant circulation device through the coolant pipeline; a compressor connected between the evaporator and the heat exchanger through the refrigerant pipeline; a sub-condenser provided in the refrigerant pipeline between the heat exchanger and the evaporator; a first expansion valve provided in the refrigerant pipeline connecting the sub-condenser and the evaporator; a second expansion valve provided in the refrigerant connection pipeline; and a receiver provided in the refrigerant pipeline between the evaporator and the compressor.

[0020] The second expansion valve may selectively expand the refrigerant passing through the sub-condenser and allow the expanded refrigerant to flow into the refrigerant connection pipeline according to the mode of the vehicle among the cooling, heating, and dehumidifying modes of the vehicle.

[0021] The first end of the refrigerant connection pipeline may be connected to the refrigerant pipeline between the sub-condenser and the first expansion valve; the second end of the refrigerant connection pipeline may be connected to the refrigerant pipeline between the receiver and the evaporator; the first end of the first branch pipeline may be connected to the refrigerant pipeline through a first refrigerant valve between the heat exchanger and the sub-condenser; and the second end of the first branch pipeline may be connected to the receiver.

[0022] The gas injection device may include: a gas-liquid separator disposed in a refrigerant pipeline between an internal condenser and a heat exchanger, separating gaseous refrigerant and liquid refrigerant in the refrigerant that has passed through the internal condenser and selectively discharging them; a supply pipeline connecting the gas-liquid separator and a compressor and selectively supplying the gaseous refrigerant from the gas-liquid separator to the compressor; a control valve disposed in the supply pipeline; a third expansion valve disposed in the refrigerant pipeline between the internal condenser and the gas-liquid separator; and a fourth expansion valve disposed in the refrigerant pipeline between the gas-liquid separator and the heat exchanger.

[0023] The heat pump system may further include: a second branch pipeline, with a first end connected to a second refrigerant valve disposed in the refrigerant pipeline between the internal condenser and the compressor and a second end connected to the refrigerant pipeline between the fourth expansion valve and the heat exchanger; a third branch pipeline, with a first end connected to a third refrigerant valve disposed in the refrigerant pipeline between the sub-condenser and the first expansion valve and a second end connected to the refrigerant pipeline between the internal condenser and the third expansion valve; and a fourth branch pipeline, with a first end connected to the refrigerant pipeline between the gas-liquid separator and the fourth expansion valve and a second end connected to the refrigerant pipeline between the third refrigerant valve and the first expansion valve and having a check valve.

[0024] When cooling the battery module in the cooling mode of the vehicle and the gas injection device operates, the coolant circulation device may supply coolant to the heat exchanger and the refrigerator through a coolant pipeline connected to the heat exchanger and the refrigerator; in the air conditioning device, the refrigerant connection pipeline may be opened by the operation of the second expansion valve; the refrigerant pipeline connected to the first expansion valve may be closed by the operation of the third refrigerant valve; the refrigerant pipeline connecting the internal condenser and the compressor may be closed by the operation of the second refrigerant valve; the refrigerant may circulate along the opened refrigerant pipeline and the refrigerant connection pipeline; the first expansion valve and the second expansion valve may expand the refrigerant so that the expanded refrigerant is respectively supplied to the evaporator and the refrigerator; the first branch pipeline may be closed; the second branch pipeline, the third branch pipeline, and the fourth branch pipeline may be opened; the refrigerant pipeline connecting the heat exchanger and the sub-condenser may be opened by the operation of the first refrigerant valve; the heat exchanger may condense the refrigerant by exchanging heat with the coolant; the sub-condenser may further condense the refrigerant by exchanging heat with the external air; in the gas injection device, the supply pipeline may be opened; the third expansion valve may expand the refrigerant supplied through the third branch pipeline and supply it to the gas-liquid separator; and the fourth expansion valve may not operate.

[0025] When cooling the battery module in the cooling mode of the vehicle and the gas injection device is not operating, the coolant circulation device can supply coolant to the heat exchanger and the refrigerator through the coolant pipeline connected to the heat exchanger and the refrigerator; in the air conditioning device, the refrigerant connection pipeline can be opened by the operation of the second expansion valve; the refrigerant can circulate along the refrigerant pipeline and the refrigerant connection pipeline; the first expansion valve and the second expansion valve can expand the refrigerant so that the expanded refrigerant is supplied to the evaporator and the refrigerator respectively; the first branch pipeline, the second branch pipeline, the third branch pipeline and the fourth branch pipeline can be closed; the refrigerant pipeline connecting the heat exchanger and the sub-condenser can be opened by the operation of the first refrigerant valve; the heat exchanger can condense the refrigerant by exchanging heat with the coolant; the sub-condenser can further condense the refrigerant by exchanging heat with the external air.

[0026] When the gas injection device operates in the heating mode of the vehicle, the supply pipeline can be opened; the third expansion valve can expand the refrigerant supplied from the internal condenser and supply it to the gas-liquid separator; the fourth expansion valve can expand the refrigerant supplied from the gas-liquid separator and supply it to the heat exchanger; the first branch pipeline can be opened by the operation of the first refrigerant valve; and the second branch pipeline, the third branch pipeline and the fourth branch pipeline can be closed.

[0027] When the gas injection device does not operate in the heating mode of the vehicle, the supply pipeline can be closed; the third expansion valve can allow the refrigerant supplied from the internal condenser to pass through; the fourth expansion valve can expand the refrigerant passing through the gas-liquid separator and supply it to the heat exchanger; the first branch pipeline can be opened by the operation of the first refrigerant valve; and the second branch pipeline, the third branch pipeline and the fourth branch pipeline can be closed.

[0028] When the gas injection device does not operate in the dehumidification mode of the vehicle, the supply pipeline can be closed; the third expansion valve can allow the refrigerant supplied from the internal condenser to pass through; the fourth expansion valve can expand the refrigerant passing through the gas-liquid separator and supply it to the heat exchanger; the first branch pipeline can be opened by the operation of the first refrigerant valve; the second branch pipeline and the third branch pipeline can be closed; and the fourth branch pipeline can be opened.

[0029] When the gas injection device operates in the dehumidification mode of the vehicle, the supply pipeline can be opened; the third expansion valve can expand the refrigerant supplied from the internal condenser and supply it to the gas-liquid separator; the fourth expansion valve can expand the refrigerant passing through the gas-liquid separator and supply it to the heat exchanger; the first branch pipeline can be opened by the operation of the first refrigerant valve; the second branch pipeline and the third branch pipeline can be closed; and the fourth branch pipeline can be opened.

[0030] When the gas injection device operates, the control valve can operate so that the supply line can be opened.

[0031] The second expansion valve, the third expansion valve, and the fourth expansion valve can be electronic expansion valves that selectively expand the refrigerant while controlling the flow of the refrigerant.

[0032] The heat exchanger can further condense or evaporate the refrigerant discharged from the gas-liquid separator by exchanging heat with the coolant according to the selective operation of the fourth expansion valve.

[0033] In the heating mode of the vehicle, the coolant circulation device can supply the coolant to the heat exchanger through the coolant line connected to the heat exchanger; in the air conditioning device, the refrigerant line connecting the sub-condenser and the evaporator can be closed by the operation of the first expansion valve; the refrigerant connection line can be closed by the operation of the second expansion valve; the fourth expansion valve can expand the refrigerant; the first branch line can be opened by the operation of the first refrigerant valve; the refrigerant line connecting the heat exchanger and the sub-condenser can be closed by the operation of the first refrigerant valve; the heat exchanger can evaporate the refrigerant by exchanging heat with the coolant; and the gas injection device can be selectively operated.

[0034] In the dehumidifying mode of the vehicle,

[0035] The coolant circulation device can supply the coolant to the heat exchanger through the coolant line connected to the heat exchanger; in the air conditioning device, the refrigerant line connecting the sub-condenser and the evaporator can be closed by the operation of the first expansion valve; the refrigerant connection line can be closed by the operation of the second expansion valve; the first branch line can be opened by the operation of the first refrigerant valve;

[0036] The refrigerant line connecting the heat exchanger and the sub-condenser can be closed by the operation of the first refrigerant valve;

[0037] The heat exchanger can evaporate the refrigerant by exchanging heat with the coolant; the fourth branch line can be opened by the operation of the check valve; and the gas injection device can be selectively operated.

[0038] The gas injection device can include: a plate heat exchanger disposed in the refrigerant line between the heat exchanger and the internal condenser; a supply line including a first end connected to the refrigerant line between the internal condenser and the plate heat exchanger and a second end connected to the compressor through the plate heat exchanger; a third expansion valve disposed in the supply line at the front end of the plate heat exchanger; and a fourth expansion valve disposed in the refrigerant line between the plate heat exchanger and the heat exchanger.

[0039] The heat exchanger can be a water-cooled heat exchanger; and the sub-condenser can be an air-cooled heat exchanger.

[0040] The gas injection device can be selectively operated in the cooling, heating, or dehumidifying mode of the vehicle.

[0041] As described above, the heat pump system for a vehicle according to an exemplary embodiment of the present invention can control the temperature of the battery module according to the vehicle mode by using a chiller that exchanges heat between the refrigerant and the coolant, thereby simplifying the system.

[0042] In addition, according to an exemplary embodiment of the present invention, by effectively controlling the temperature of the battery module, the battery module can operate with optimal performance, and the total mileage of the vehicle can be increased by effectively managing the battery module.

[0043] In addition, according to an exemplary embodiment of the present invention, the flow rate of the refrigerant can be selectively increased in the cooling, heating, or dehumidifying mode of the vehicle by applying the gas injection device, thereby maximizing the cooling and heating performance.

[0044] In addition, according to an exemplary embodiment of the present invention, the manufacturing cost and weight can be reduced by simplifying the entire system, and the space utilization rate can be improved.

[0045] The method and apparatus of the present invention have other features and advantages that will become apparent in or will be more particularly set forth in the accompanying drawings and the following detailed description, which are incorporated herein to explain certain principles of the present invention. Description of the Drawings

[0046] Figure 1 A block diagram showing a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0047] Figure 2 A block diagram showing a gas injection device applied to a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0048] Figure 3 An operating state diagram showing that in a heat pump system for a vehicle according to various exemplary embodiments of the present invention, the battery module is cooled by using the refrigerant in the cooling mode of the vehicle and the gas injection device is not operating.

[0049] Figure 4 An operating state diagram showing that in a heat pump system for a vehicle according to various exemplary embodiments of the present invention, the battery module is cooled by using the refrigerant in the cooling mode of the vehicle and the gas injection device is operating.

[0050] Figure 5The operation state diagram showing the non - operation of the gas injection device in the heating mode of a vehicle in a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0051] Figure 6 The operation state diagram showing the operation of the gas injection device in the heating mode of a vehicle in a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0052] Figure 7 The operation state diagram showing the non - operation of the gas injection device in the dehumidifying mode of a vehicle in a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0053] Figure 8 The operation state diagram showing the operation of the gas injection device in the dehumidifying mode of a vehicle in a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0054] It is understood that the drawings are not necessarily drawn to scale, but present a somewhat simplified representation of various features illustrating the basic principles of the present invention. Specific design features of the present invention included herein, including, for example, specific dimensions, orientations, positions, and shapes, will be determined in part by the particular intended application and use environment.

[0055] In several of the figures of the drawings, reference numerals refer to the same or equivalent parts in the present invention. Detailed Description of the Invention

[0056] Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the drawings and described below. Although the present invention will be described in conjunction with the exemplary embodiments of the present invention, it should be understood that this description is not intended to limit the present invention to those exemplary embodiments. On the other hand, the present invention is intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, modifications, equivalent forms, and other embodiments that may be included within the spirit and scope of the present invention as defined by the appended claims.

[0057] Various exemplary embodiments of the present invention will be described in detail below with reference to the drawings.

[0058] The exemplary embodiments described in this specification and the configurations shown in the drawings are only the most preferred exemplary embodiments of the present invention, but do not limit the spirit and scope of the present disclosure. Therefore, it should be understood that there may be various equivalent forms and modifications that can replace these exemplary embodiments and configurations when this application is filed.

[0059] To clearly describe the present invention, parts irrelevant to the present invention will be omitted, and the same elements or equivalent parts will be referred to by the same reference numerals throughout the specification.

[0060] The dimensions and thicknesses of each element are arbitrarily shown in the drawings, but the present disclosure is not necessarily limited thereto, and in the drawings, for clarity, the thicknesses of layers, films, plates, regions, etc. are exaggerated.

[0061] In this specification and the appended claims, unless there is a contrary explicit description, the word "comprising" and variations such as "comprises" or "comprising" will be understood to imply the inclusion of the stated element but not the exclusion of any other element.

[0062] In addition, terms such as "…… unit", "…… mechanism", "…… part", and "…… component" used herein refer to a general component unit that performs at least one or more functions or operations.

[0063] Figure 1 is a block diagram of a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0064] A heat pump system for a vehicle according to various exemplary embodiments of the present invention can control the temperature of a battery module by using a chiller 40 that exchanges heat between a refrigerant and a coolant, and can improve the heating performance by applying a gas injection device 30.

[0065] Here, in the heat pump system, a coolant circulation device 3 that supplies coolant to electrical components and a battery module in an electric vehicle and an air conditioning device 10 for cooling and heating the interior of the vehicle can be linked.

[0066] That is, referring to Figure 1 , the heat pump system may include a coolant circulation device 3, an air conditioning device 10, and a chiller 40.

[0067] First, the coolant circulation device 3 circulates the coolant through a coolant line 5. The coolant circulation device 3 may be connected to electrical components and a battery module (not shown) through the coolant line 5.

[0068] In addition, the coolant circulation device 3 may include a radiator, a water pump, a liquid storage tank, etc. (not shown).

[0069] The electrical components may include power conversion devices such as an electric power control unit (EPCU), a motor, an inverter, and an on-vehicle charger (OBC), as well as an autonomous driving controller.

[0070] The electrical components as described above may be connected to the coolant line 5 to be cooled by water cooling.

[0071] The coolant circulation device 3 circulates the coolant cooled by the radiator along the coolant line 5 through the operation of a water pump to cool the electrical components or the battery module to prevent overheating.

[0072] On the other hand, in various exemplary embodiments of the present invention, only one coolant circulation device 3 is provided as an example, but the present invention is not limited thereto, and each coolant circulation device may be applied to supply coolant to the electrical component and the battery module, respectively.

[0073] In various exemplary embodiments of the present invention, the air conditioning device 10 includes a heating, ventilation, and air conditioning (HVAC) module 12, a heat exchanger 13, a sub-condenser 14, a first expansion valve 15, an evaporator 16, a liquid receiver 17, a compressor 19, a refrigerant connection pipeline 21, a second expansion valve 23, and a first branch pipeline 25, which are connected through a refrigerant pipeline 11.

[0074] First, the HVAC module 12 includes an evaporator 16 connected through a refrigerant pipeline 11 and an opening / closing door 12b that controls selectively inflowing external air passing through the evaporator 16 into the internal condenser 12a according to the cooling, heating, and dehumidifying modes of the vehicle.

[0075] That is, in the heating mode of the vehicle, the opening / closing door 12b is opened so that the external air passing through the evaporator 16 flows into the internal condenser 12a.

[0076] On the contrary, in the cooling mode of the vehicle, the opening / closing door 12b closes the internal condenser 12a side so that the external air cooled when passing through the evaporator 16 directly flows into the vehicle interior.

[0077] The internal condenser 12a can condense the refrigerant supplied from the compressor 19 by exchanging heat with external air.

[0078] In various exemplary embodiments of the present invention, the heat exchanger 13 is connected to the refrigerant pipeline 11 so that the refrigerant passes through it. The heat exchanger 13 can be connected to the coolant circulation device 3 through a coolant pipeline 5 so that coolant is supplied from the coolant circulation device 3.

[0079] That is, the heat exchanger 13 can condense or evaporate the refrigerant by exchanging heat with the coolant supplied through the coolant pipeline 5. The heat exchanger 13 can be a water-cooled heat exchanger into which the coolant flows.

[0080] In an exemplary embodiment of the present invention, the sub-condenser 14 may be provided in the refrigerant pipeline 11 between the heat exchanger 13 and the evaporator 16. The sub-condenser 14 can be an air-cooled heat exchanger that condenses the refrigerant by using external air.

[0081] The first expansion valve 15 is provided in the refrigerant pipeline 11 between the sub-condenser 14 and the evaporator 16. The first expansion valve 15 receives the refrigerant passing through the sub-condenser 14 and expands it.

[0082] The accumulator 17 is provided in the refrigerant pipeline 11 between the evaporator 16 and the compressor 19.

[0083] The accumulator 17 improves the efficiency and durability of the compressor 19 by supplying only gaseous refrigerant to the compressor 19.

[0084] The compressor 19 is connected between the evaporator 16 and the heat exchanger 13 through the refrigerant pipeline 11. The compressor 19 can compress the gaseous refrigerant and supply the compressed refrigerant to the internal condenser 12a.

[0085] In various exemplary embodiments of the present invention, the first end of the refrigerant connection pipeline 21 is connected to the refrigerant pipeline 11 between the sub-condenser 14 and the first expansion valve 15. In addition, the second end of the refrigerant connection pipeline 21 can be connected to the refrigerant pipeline 11 between the evaporator 16 and the accumulator 17.

[0086] Meanwhile, the second expansion valve 23 can be provided in the refrigerant connection pipeline 21.

[0087] The second expansion valve 23 can selectively expand the refrigerant passing through the sub-condenser 14 and make it flow into the refrigerant connection pipeline 21, or make the refrigerant passing through the sub-condenser 14 pass through the refrigerant connection pipeline 21 according to the mode of the vehicle.

[0088] When cooling the battery module by using the coolant that exchanges heat with the refrigerant, the second expansion valve 23 expands the refrigerant flowing into through the refrigerant connection pipeline 21 and makes it flow into the refrigerator 40.

[0089] That is, the second expansion valve 23 expands the refrigerant discharged from the sub-condenser 14 to reduce its temperature and make it flow into the refrigerator 40, so that the temperature of the coolant passing through the inside of the refrigerator 40 can be further reduced.

[0090] Therefore, the coolant whose water temperature is reduced when passing through the refrigerator 40 can flow in and cool the battery module.

[0091] In the exemplary embodiment of the present invention, based on the flow direction of the refrigerant, the first branch pipeline 25 is connected to the refrigerant pipeline 11 through the first refrigerant valve 24 at the rear end of the heat exchanger 13.

[0092] That is, the first end of the first branch pipeline 25 is connected to the refrigerant pipeline 11 between the heat exchanger 13 and the sub-condenser 14 through the first refrigerant valve 24. The second end of the first branch pipeline 25 can be connected to the accumulator 17.

[0093] In the heating mode or dehumidifying mode of the vehicle, the first branch pipeline 25 can be opened by the operation of the first refrigerant valve 24. In this case, the first refrigerant valve 24 can close the refrigerant pipeline 11 connected to the sub-condenser 14.

[0094] Meanwhile, in various exemplary embodiments of the present invention, the heat pump system may further include a gas injection device 30.

[0095] The gas injection device 30 is disposed in the air conditioning device 10.

[0096] The gas injection device 30 can bypass a part of the refrigerant supplied to the refrigerant pipeline 11 to the compressor 19 to increase the flow rate of the refrigerant circulating in the refrigerant pipeline 11.

[0097] The gas injection device 30 configured as described above can be selectively operated in the cooling, heating, or dehumidifying mode of the vehicle.

[0098] Here, the gas injection device 30 includes a gas-liquid separator 31, a supply pipeline 32, a control valve 33, a third expansion valve 34, and a fourth expansion valve 35.

[0099] First, the gas-liquid separator 31 is disposed in the refrigerant pipeline 11 between the internal condenser 12a and the heat exchanger 13.

[0100] The gas-liquid separator 31 can completely separate the gaseous refrigerant and the liquid refrigerant in the refrigerant that has completed heat exchange when passing through the internal condenser 12a and selectively discharge them.

[0101] The supply pipeline 32 connects the gas-liquid separator 31 and the compressor 19. The supply pipeline 32 can selectively supply the gaseous refrigerant from the gas-liquid separator 31 to the compressor 19.

[0102] That is, the supply pipeline 32 can connect the gas-liquid separator 31 and the compressor 19 such that the gaseous refrigerant passing through the gas-liquid separator 31 can selectively flow into the compressor 19.

[0103] In various exemplary embodiments of the present invention, the control valve 33 is disposed in the supply pipeline 32. The control valve 33 can selectively open the supply pipeline 32 according to the vehicle mode.

[0104] That is, the control valve 33 can be operated such that the supply pipeline 32 can be opened when the gas injection device 30 operates.

[0105] Here, the gas-liquid separator 31 can supply the gaseous refrigerant to the compressor 19 through the supply pipeline 32 opened by the operation of the control valve 33. In addition, the gas-liquid separator 31 can supply the liquid refrigerant to the heat exchanger 13.

[0106] The third expansion valve 34 is provided in the refrigerant pipeline 11 between the internal condenser 12a and the gas-liquid separator 31.

[0107] In addition, the fourth expansion valve 35 may be provided in the refrigerant pipeline 11 between the gas-liquid separator 31 and the heat exchanger 13.

[0108] That is, when the battery module is cooled in the cooling mode of the vehicle and the gas injection device 30 operates, the third expansion valve 34 can expand the refrigerant flowing into the refrigerant pipeline 11 and supply it to the gas-liquid separator 31. The fourth expansion valve 35 does not operate.

[0109] Therefore, the refrigerant passing through the gas-liquid separator 31 may not flow into the heat exchanger 13.

[0110] On the contrary, when the battery module is cooled in the cooling mode of the vehicle and the gas injection device 30 does not operate, the third expansion valve 34 and the fourth expansion valve 35 may not expand the refrigerant supplied to the internal condenser 12a and allow it to flow through the refrigerant pipeline 11.

[0111] In addition, when the gas injection device 30 operates in the heating mode of the vehicle, the third expansion valve 34 can expand the refrigerant supplied from the internal condenser 12a and supply it to the gas-liquid separator 31.

[0112] In addition, the fourth expansion valve 35 can expand the refrigerant supplied from the gas-liquid separator 31 and allow it to flow through the refrigerant pipeline 11.

[0113] On the contrary, when the gas injection device 30 does not operate in the heating mode of the vehicle, the third expansion valve 34 can allow the refrigerant supplied from the internal condenser 12a to pass through.

[0114] In addition, the fourth expansion valve 35 can expand the refrigerant passing through the gas-liquid separator 31 and supply it to the heat exchanger 13.

[0115] Meanwhile, when the gas injection device 30 operates in the dehumidifying mode of the vehicle, the third expansion valve 34 can expand the refrigerant supplied from the internal condenser 12a and supply it to the gas-liquid separator 31.

[0116] In addition, the fourth expansion valve 35 can expand the refrigerant passing through the gas-liquid separator 31 and supply it to the heat exchanger 13.

[0117] On the contrary, when the gas injection device 30 does not operate in the dehumidifying mode of the vehicle, the third expansion valve 34 can allow the refrigerant supplied from the internal condenser 12a to pass through.

[0118] In addition, the fourth expansion valve 35 can expand the refrigerant passing through the gas-liquid separator 31 and supply it to the heat exchanger 13.

[0119] Here, the heat exchanger 13 can selectively condense or evaporate the refrigerant passing through the internal condenser 12a according to whether the gas injection device 30 operates.

[0120] The heat exchanger 13 further condenses or evaporates the refrigerant discharged from the gas-liquid separator 31 by exchanging heat with the coolant according to the selective operation of the fourth expansion valve 35.

[0121] When the heat exchanger 13 condenses the refrigerant, the heat exchanger 13 further condenses the refrigerant condensed in the internal condenser 12a, and the sub-condenser 14 further condenses the refrigerant, so that the subcooling of the refrigerant can be increased, and thus the coefficient of performance (COP), which is a coefficient of cooling capacity compared to the required power of the compressor, can be improved.

[0122] Meanwhile, the gas injection device 30 can further include a separate connection pipeline (not shown), the first end of which is connected to the refrigerant pipeline 11 between the internal condenser 12a and the third expansion valve 34, and the second end of which is connected to the refrigerant pipeline 11 between the fourth expansion valve 35 and the heat exchanger 13.

[0123] A separate on-off valve (not shown) can be provided in the separate connection pipeline.

[0124] That is, the connection pipeline is opened by the operation of the on-off valve, and in this case, the refrigerant passing through the internal condenser 12a can be directly supplied to the heat exchanger 13 without passing through the gas injection device 30.

[0125] Therefore, when the gas injection device 30 does not operate, the pressure of the refrigerant circulating along the refrigerant pipeline 11 can be reduced.

[0126] Meanwhile, the air-conditioning device 10 can further include a second branch pipeline 27, a third branch pipeline 29, and a fourth branch pipeline 51.

[0127] First, the first end of the second branch pipeline 27 is connected to the second refrigerant valve 26 in the refrigerant pipeline 11 provided between the internal condenser 12a and the compressor 19.

[0128] The second end of the second branch pipeline 27 is connected to the refrigerant pipeline 11 between the fourth expansion valve 35 and the heat exchanger 13.

[0129] In an exemplary embodiment of the present invention, the first end of the third branch pipeline 29 is connected to a third refrigerant valve 28 in a refrigerant pipeline 11 disposed between an auxiliary condenser 14 and a first expansion valve 15.

[0130] The second end of the third branch pipeline 29 is connected to the refrigerant pipeline 11 between an internal condenser 12a and a third expansion valve 34.

[0131] The first end of the fourth branch pipeline 51 is connected to the refrigerant pipeline 11 between a gas-liquid separator 31 and a fourth expansion valve 35.

[0132] The second end of the fourth branch pipeline 51 is connected to the refrigerant pipeline 11 between the third refrigerant valve 28 and the first expansion valve 15. Here, a check valve 53 may be disposed in the fourth branch pipeline 51.

[0133] That is, in the cooling and dehumidifying mode of the vehicle, the fourth branch pipeline 51 can be selectively opened by the operation of the check valve 53.

[0134] In an exemplary embodiment of the present invention, a refrigerator 40 is connected to a coolant circulation device 3 through a coolant pipeline 5, and the coolant can selectively circulate therein.

[0135] The refrigerator 40 is connected to the refrigerant pipeline 11 through a refrigerant connection pipeline 21. That is, the refrigerator 40 can be a water-cooled heat exchanger into which the coolant flows.

[0136] Therefore, the refrigerator 40 exchanges heat between the coolant flowing selectively through the coolant pipeline 5 and the refrigerant selectively supplied from the air-conditioning device 10 to control the temperature of the coolant.

[0137] In an exemplary embodiment of the present invention, the first expansion valve 15 can be a mechanical expansion valve, while the second expansion valve 23, the third expansion valve 34, and the fourth expansion valve 35 can be electronic expansion valves that selectively expand the refrigerant while controlling the flow of the refrigerant through the refrigerant pipeline 11 or the refrigerant connection pipeline 21.

[0138] Meanwhile, reference will be made to Figure 2 Describe a gas injection device 130 according to various exemplary embodiments of the present invention.

[0139] Figure 2 A block diagram showing a gas injection device applied to a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0140] Reference is made to Figure 2 , and a gas injection device 130 according to various exemplary embodiments of the present invention is disposed in the air-conditioning device 10.

[0141] Here, the gas injection device 130 may include a plate heat exchanger 131, a supply pipeline 132, a third expansion valve 133, and a fourth expansion valve 134.

[0142] First, the plate heat exchanger 131 may be disposed in the refrigerant pipeline 11 between the internal condenser 12a and the heat exchanger 13.

[0143] The first end of the supply pipeline 132 is connected to the refrigerant pipeline 11 between the internal condenser 12a and the plate heat exchanger 131.

[0144] The second end of the supply pipeline 132 may be connected to the compressor 19 through the plate heat exchanger 131.

[0145] That is, a part of the refrigerant in the refrigerant flowing through the internal condenser 12a or flowing in through the third branch pipeline 29 may flow into the supply pipeline 132, and the remaining refrigerant may flow into the plate heat exchanger 131 through the refrigerant pipeline 11.

[0146] The third expansion valve 133 may be disposed in the supply pipeline 132 at the front end of the plate heat exchanger 131.

[0147] The third expansion valve 133 may selectively open and close the supply pipeline 132 according to whether the gas injection device 130 operates, and may selectively expand the refrigerant flowing into the supply pipeline 132.

[0148] In addition, the fourth expansion valve 134 may be disposed in the refrigerant pipeline 11 between the plate heat exchanger 131 and the heat exchanger 13.

[0149] Here, in the cooling mode, heating mode, or dehumidifying mode of the vehicle, when the gas injection device 130 operates, the third expansion valve 133 may expand the refrigerant flowing into the supply pipeline 132 and supply it to the plate heat exchanger 131.

[0150] Therefore, the plate heat exchanger 131 may exchange heat between the refrigerant that expands and flows into the supply pipeline 132 through the operation of the third expansion valve 133 and the refrigerant passing through the refrigerant pipeline 11.

[0151] Therefore, the supply pipeline 132 may selectively supply the gaseous refrigerant in the refrigerant that has undergone heat exchange when passing through the plate heat exchanger 131 to the compressor 19.

[0152] The operation of the gas injection device 130 configured as described above is as follows.

[0153] First, according to the operation of the third expansion valve 133, a part of the refrigerant passing through the internal condenser 12a flows into the supply pipeline 132.

[0154] The refrigerant flowing into the supply pipeline 132 expands by the operation of the third expansion valve 133, and the expanded refrigerant turns into a gas inside the plate heat exchanger 131 by exchanging heat with the remaining refrigerant flowing in through the refrigerant pipeline 11.

[0155] The gaseous refrigerant is supplied to the compressor 19 through the opened supply pipeline 132.

[0156] That is, the gas injection device 130 causes the gaseous refrigerant that has exchanged heat when passing through the plate heat exchanger 131 to flow back into the compressor 19 through the supply pipeline 132, thereby increasing the flow rate of the refrigerant circulating in the refrigerant pipeline 11.

[0157] On the other hand, in the heating or dehumidifying mode of the vehicle, the fourth expansion valve 134 can expand the refrigerant passing through the plate heat exchanger 131 and make it flow through the refrigerant pipeline 11 regardless of whether the gas injection device 130 is operating.

[0158] In addition, when the gas injection device 130 operates in the cooling mode of the vehicle, the fourth expansion valve 134 may not operate.

[0159] Hereinafter, reference will be made to Figures 3 to 8 Describe in detail the operation and function of the heat pump system for a vehicle according to an exemplary embodiment of the present invention having the above-described configuration.

[0160] First, reference will be made to Figure 3 Describe the operation in the case of cooling the battery module in the cooling mode of the vehicle and the gas injection device 30 not operating.

[0161] Figure 3 Show an operating state diagram of cooling the battery module by using a refrigerant in the cooling mode of the vehicle in a heat pump system for a vehicle according to various exemplary embodiments of the present invention and the gas injection device not operating.

[0162] Refer to Figure 3 The coolant circulation device 3 supplies coolant to the heat exchanger 13 and the refrigerator 40 through the coolant pipeline 5 connected to the heat exchanger 13 and the refrigerator 40.

[0163] In the air conditioning device 10, each component operates to cool the vehicle interior. Therefore, the refrigerant circulates along the refrigerant pipeline 11.

[0164] Here, the refrigerant pipeline 11 connecting the sub-condenser 14 and the evaporator 16 is opened by the operation of the first expansion valve 15. The refrigerant connection pipeline 21 is opened by the operation of the second expansion valve 23.

[0165] In addition, the first branch pipeline 25 is closed by the operation of the first refrigerant valve 24. The second branch pipeline 27 is closed by the operation of the second refrigerant valve 26. The third branch pipeline 29 is closed by the operation of the third refrigerant valve 28. And the fourth branch pipeline 51 is closed by the operation of the check valve 53.

[0166] Therefore, the refrigerant passing through the sub-condenser 14 can circulate along the refrigerant pipeline 11 and the refrigerant connection pipeline 21.

[0167] Here, the first expansion valve 15 and the second expansion valve 23 can expand the refrigerant so that the expanded refrigerant can be supplied to the evaporator 16 and the refrigerator 40 respectively.

[0168] In addition, the sub-condenser 14 can further condense the refrigerant flowing in from the heat exchanger 13 by exchanging heat with the external air.

[0169] Meanwhile, the coolant passing through the refrigerator 40 can cool the battery module connected to the coolant circulation device 3.

[0170] That is, the coolant passing through the refrigerator 40 is cooled by exchanging heat with the refrigerant supplied to the refrigerator 40. The coolant cooled in the refrigerator 40 is supplied to the battery module. Therefore, the battery module can be effectively cooled by the cooled coolant.

[0171] That is, the second expansion valve 23 expands a part of the refrigerant in the refrigerant passing through the sub-condenser 14 so that the expanded refrigerant is supplied to the refrigerator 40.

[0172] Therefore, a part of the refrigerant discharged from the sub-condenser 14 expands through the operation of the second expansion valve 23 to become a low-temperature and low-pressure state and flows into the refrigerator 40 provided in the refrigerant connection pipeline 21.

[0173] Then, the refrigerant flowing into the refrigerator 40 exchanges heat with the coolant, and flows into the compressor 19 through the accumulator 17 via the refrigerant pipeline 11 connected to the refrigerant connection pipeline 21.

[0174] Meanwhile, the remaining refrigerant discharged from the sub-condenser 14 flows through the refrigerant pipeline 11 to cool the vehicle interior, and sequentially passes through the first expansion valve 15, the evaporator 16, the accumulator 17, the compressor 19, the internal condenser 12a, and the heat exchanger 13.

[0175] Here, the external air flowing into the HVAC module 12 is cooled by the low-temperature refrigerant flowing into the evaporator 16 when passing through the evaporator 16.

[0176] In this case, the opening / closing door 12b closes a part passing through the internal condenser 12a, so that the cooled outside air does not pass through the internal condenser 12a. Therefore, the cooled outside air directly flows into the vehicle interior, thereby cooling the vehicle interior.

[0177] Meanwhile, the refrigerant with an increased condensation amount while passing through the heat exchanger 13 and the sub-condenser 14 in sequence expands and is supplied to the evaporator 16, so that the refrigerant can evaporate at a lower temperature.

[0178] That is, in various exemplary embodiments of the present invention, the heat exchanger 13 condenses the refrigerant by exchanging heat with the coolant, and the sub-condenser 14 further condenses the refrigerant by exchanging heat with the outside air, thereby advantageously performing subcooling of the refrigerant.

[0179] In addition, since the subcooled refrigerant evaporates at a lower temperature in the evaporator 16, the temperature of the outside air passing through the evaporator 16 can be further reduced, thereby improving the cooling performance and efficiency.

[0180] Meanwhile, in the gas injection device 30, the supply pipeline 32 is closed by the operation of the control valve 33. Here, the refrigerant discharged from the internal condenser 12a can be supplied to the heat exchanger 13 without expanding in the third expansion valve 34 and the fourth expansion valve 35.

[0181] That is, the third expansion valve 34 and the fourth expansion valve 35 can cause the refrigerant supplied from the internal condenser 12a to flow through the refrigerant pipeline 11 without expanding.

[0182] While repeating the above process, the refrigerant can cool the interior in the cooling mode of the vehicle, and at the same time, the refrigerant can cool the coolant by heat exchange while passing through the refrigerator 40.

[0183] The low-temperature coolant cooled in the refrigerator 40 flows into the battery module. Therefore, the battery module can be effectively cooled by the supplied low-temperature coolant.

[0184] Reference will be made to Figure 4 Describe the operation in the case where the battery module is cooled in the cooling mode of the vehicle and the gas injection device 30 operates.

[0185] Figure 4 The operation state diagram shows the operation of using the refrigerant to cool the battery module in the cooling mode of the vehicle and the operation of the gas injection device in a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0186] Reference Figure 4 , the coolant circulation device 3 supplies the coolant to the heat exchanger 13 and the refrigerator 40 respectively through the coolant pipeline 5 connected to the heat exchanger 13 and the refrigerator 40.

[0187] In the air conditioner 10, each component operates to heat the vehicle interior. Therefore, the refrigerant circulates along the refrigerant pipeline 11.

[0188] Here, the refrigerant pipeline 11 connecting the sub-condenser 14 and the third refrigerant valve 28 is opened. The refrigerant connection pipeline 21 is opened by the operation of the second expansion valve 23.

[0189] Based on the third refrigerant valve 28, the refrigerant pipeline 11 connected to the first expansion valve 15 is closed by the operation of the third refrigerant valve 28.

[0190] In addition, the refrigerant pipeline 11 connecting the internal condenser 12a and the compressor 19 is closed by the operation of the second refrigerant valve 26. At the same time, the refrigerant pipeline 11 connecting the heat exchanger 13 and the sub-condenser 14 is opened by the operation of the first refrigerant valve 24.

[0191] Here, the first branch pipeline 25 is closed by the operation of the first refrigerant valve 24, and the second branch pipeline 27 is opened by the operation of the second refrigerant valve 26.

[0192] In addition, the third branch pipeline 29 is opened by the operation of the third refrigerant valve 28, and the fourth branch pipeline 51 is opened by the operation of the check valve 53.

[0193] Therefore, the refrigerant can circulate along the opened refrigerant pipeline 11, the opened refrigerant connection pipeline 21, and the opened second branch pipeline 27, third branch pipeline 29, and fourth branch pipeline 51.

[0194] That is, the refrigerant discharged from the compressor 19 flows into the heat exchanger 13 along the opened second branch pipeline 27. The heat exchanger 13 can condense the refrigerant flowing into the opened second branch pipeline 27 from the compressor 19 by exchanging heat with the coolant.

[0195] Therefore, the sub-condenser 14 can further condense the refrigerant flowing in from the heat exchanger 13 by exchanging heat with the outside air.

[0196] The refrigerant passing through the sub-condenser 14 can be supplied to the gas injection device 30 along the opened refrigerant pipeline 11 and the third branch pipeline 29.

[0197] At the same time, in the gas injection device 30, the supply pipeline 32 is opened by the operation of the control valve 33.

[0198] In this state, the third expansion valve 34 expands the refrigerant supplied through the third branch pipeline 29 and supplies it to the gas-liquid separator 31, and the fourth expansion valve 35 does not operate.

[0199] The gaseous refrigerant in the refrigerant supplied to the gas-liquid separator 31 is supplied to the compressor 19 through the opened supply line 32.

[0200] That is, the gas injection device 30 causes the gaseous refrigerant that has undergone heat exchange when passing through the gas-liquid separator 31 to flow back into the compressor 19 through the supply line 32, thereby increasing the flow rate of the refrigerant circulating in the refrigerant line 11.

[0201] In addition, the liquid refrigerant discharged from the gas-liquid separator 31 through the refrigerant line 11 flows into the refrigerant line 11 between the third refrigerant valve 28 and the refrigerant connection line 21 along the opened fourth branch line 51.

[0202] Therefore, a part of the refrigerant in the refrigerant flowing into the fourth branch line 51 flows into the refrigerant connection line 21 opened by the operation of the second expansion valve 23. The remaining refrigerant passes through the first expansion valve 15 and is supplied to the evaporator 16.

[0203] Here, the first expansion valve 15 and the second expansion valve 23 can expand the refrigerant so that the expanded refrigerant is supplied to the evaporator 16 and the refrigerator 40 respectively.

[0204] At the same time, the coolant passing through the refrigerator 40 can cool the battery module connected to the coolant circulation device 3.

[0205] That is, the coolant passing through the refrigerator 40 is cooled by heat exchange with the expanded refrigerant supplied to the refrigerator 40. The coolant cooled in the refrigerator 40 flows into the battery module. Therefore, the battery module can be effectively cooled by the cooled coolant.

[0206] That is, the second expansion valve 23 expands a part of the refrigerant flowing into the refrigerant line 11 along the fourth branch line 51 so that the expanded refrigerant is supplied to the refrigerator 40.

[0207] Therefore, a part of the refrigerant flowing into the refrigerant connection line 21 expands through the operation of the second expansion valve 23 to become a low-temperature and low-pressure state, and flows into the refrigerator 40 provided in the refrigerant connection line 21.

[0208] Therefore, the refrigerant flowing into the refrigerator 40 exchanges heat with the coolant, and flows into the compressor 19 after passing through the accumulator 17 through the refrigerant line 11 connected to the refrigerant connection line 21.

[0209] Meanwhile, the remaining refrigerant flowing into the refrigerant pipeline 11 from the fourth branch pipeline 51 flows through the refrigerant pipeline 11 to cool the vehicle interior and sequentially passes through the first expansion valve 15, the evaporator 16, the accumulator 17, the compressor 19, the internal condenser 12a, and the heat exchanger 13.

[0210] Here, the outside air flowing into the HVAC module 12 is cooled by the low-temperature refrigerant flowing into the evaporator 16 while passing through the evaporator 16.

[0211] In this case, the opening / closing door 12b closes the part passing through the internal condenser 12a so that the cooled outside air does not pass through the internal condenser 12a. Therefore, the cooled outside air directly flows into the vehicle interior, thereby cooling the vehicle interior.

[0212] Meanwhile, the refrigerant with an increased condensation amount when sequentially passing through the heat exchanger 13, the sub-condenser 14, and the gas-liquid separator 31 expands and is supplied to the evaporator 16, so that the refrigerant can evaporate at a lower temperature.

[0213] That is, in various exemplary embodiments of the present invention, the heat exchanger 13 condenses the refrigerant by exchanging heat with the coolant, and the sub-condenser 14 further condenses the refrigerant by exchanging heat with the outside air, thereby advantageously performing subcooling of the refrigerant.

[0214] In addition, since the subcooled refrigerant evaporates at a lower temperature in the evaporator 16, the temperature of the outside air passing through the evaporator 16 can be further reduced, thereby improving the cooling performance and efficiency.

[0215] In addition, the gas injection device 30 can maximize the cooling efficiency by increasing the flow rate of the refrigerant circulating in the refrigerant pipeline 11.

[0216] While repeating the above process, the refrigerant can cool the interior in the cooling mode of the vehicle, and at the same time, the refrigerant can cool the coolant through heat exchange while passing through the refrigerator 40.

[0217] The low-temperature coolant cooled in the refrigerator 40 flows into the battery module. Therefore, the battery module can be effectively cooled by the supplied low-temperature coolant.

[0218] In various exemplary embodiments of the present invention, reference will be made to Figure 5 Describe the operation when the gas injection unit 30 does not operate in the heating mode of the vehicle.

[0219] Figure 5 The operation state diagram showing the operation when the gas injection device does not operate in the heating mode of the vehicle in the heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0220] Refer toFigure 5 , the coolant circulation device 3 supplies coolant to the heat exchanger 13 through the coolant pipeline 5 connected to the heat exchanger 13. In this case, the coolant pipeline 5 connected to the refrigerator 40 is closed.

[0221] In the air conditioning device 10, each component operates to heat the vehicle interior. Therefore, the refrigerant circulates along the refrigerant pipeline 11.

[0222] Here, the refrigerant pipeline 11 connecting the sub-condenser 14 and the evaporator 16 is closed by the operation of the first expansion valve 15.

[0223] The refrigerant connection pipeline 21 is closed by the operation of the second expansion valve 23.

[0224] At the same time, the first branch pipeline 25 is opened by the operation of the first refrigerant valve 24, and the second branch pipeline 27 is closed by the operation of the second refrigerant valve 26.

[0225] The third branch pipeline 29 is closed by the operation of the third refrigerant valve 28, and the fourth branch pipeline 51 is closed by the operation of the check valve 53.

[0226] In addition, the refrigerant pipeline 11 connecting the heat exchanger 13 and the sub-condenser 14 can be closed by the operation of the first refrigerant valve 24.

[0227] Here, when the gas injection device 30 is not operating, the supply pipeline 32 is closed by the operation of the control valve 33. In addition, the third expansion valve 34 allows the refrigerant supplied from the internal condenser 12a to pass through.

[0228] The fourth expansion valve 35 can expand the refrigerant passing through the gas-liquid separator 31 and supply it to the heat exchanger 13.

[0229] Therefore, the heat exchanger 13 can evaporate the expanded refrigerant by exchanging heat with the coolant.

[0230] The refrigerant evaporated in the heat exchanger 13 is supplied to the accumulator 17 along the first branch pipeline 25.

[0231] The refrigerant supplied to the accumulator 17 is separated into gas and liquid. The gaseous refrigerant in the refrigerant separated into gas and liquid is supplied to the compressor 19.

[0232] The refrigerant compressed into a high-temperature and high-pressure state in the compressor 19 flows into the internal condenser 12a.

[0233] Here, the refrigerant supplied to the internal condenser 12a can raise the temperature of the external air flowing into the HVAC module 12.

[0234] The opening and closing door 12b is opened so that the outside air flowing into the HVAC module 12 and passing through the evaporator 16 passes through the internal condenser 12a.

[0235] Therefore, the outside air flowing in from the outside flows in at room temperature without being cooled when passing through the evaporator 16 where no refrigerant is supplied. The flowing-in outside air is converted to a high temperature state when passing through the internal condenser 12a and flows into the vehicle interior, thereby heating the vehicle interior.

[0236] In various exemplary embodiments of the present invention, reference will be made to Figure 6 Describe the operation when the gas injection device 30 operates in the heating mode of the vehicle.

[0237] Figure 6 The operation state diagram showing the operation of the gas injection device in the heating mode of the vehicle in a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0238] Refer to Figure 6 The coolant circulation device 3 supplies coolant to the heat exchanger 13 through the coolant pipeline 5 connected to the heat exchanger 13. In this case, the coolant pipeline 5 connected to the refrigerator 40 is closed.

[0239] In the air conditioning device 10, each component operates to heat the vehicle interior. Therefore, the refrigerant circulates along the refrigerant pipeline 11.

[0240] Here, the refrigerant pipeline 11 connecting the sub-condenser 14 and the evaporator 16 is closed by the operation of the first expansion valve 15.

[0241] The refrigerant connection pipeline 21 is closed by the operation of the second expansion valve 23.

[0242] At the same time, the first branch pipeline 25 is opened by the operation of the first refrigerant valve 24, and the second branch pipeline 27 is closed by the operation of the second refrigerant valve 26.

[0243] The third branch pipeline 29 is closed by the operation of the third refrigerant valve 28, and the fourth branch pipeline 51 is closed by the operation of the check valve 53.

[0244] In addition, the refrigerant pipeline 11 connecting the heat exchanger 13 and the sub-condenser 14 can be closed by the operation of the first refrigerant valve 24.

[0245] Here, when the gas injection device 30 operates, the supply pipeline 32 is opened by the operation of the control valve 33.

[0246] In this state, the third expansion valve 34 expands the refrigerant supplied from the internal condenser 12a and supplies it to the gas-liquid separator 31.

[0247] The gaseous refrigerant in the refrigerant supplied to the gas-liquid separator 31 is supplied to the compressor 19 through the opened supply pipeline 32.

[0248] That is, the gas injection device 30 causes the gaseous refrigerant that has undergone heat exchange when passing through the gas-liquid separator 31 to flow back into the compressor 19 through the supply pipeline 32, thereby increasing the flow rate of the refrigerant circulating in the refrigerant pipeline 11.

[0249] In addition, the liquid refrigerant discharged from the gas-liquid separator 31 through the refrigerant pipeline 11 flows into the heat exchanger 13 along the refrigerant pipeline 11 opened by the operation of the fourth expansion valve 35.

[0250] In this case, the fourth expansion valve 35 can expand the refrigerant supplied from the gas-liquid separator 31.

[0251] That is, the gas-liquid separator 31 of the gas injection device 30 can bypass the gaseous refrigerant to the compressor 19 through the supply pipeline 32, and can supply the liquid refrigerant to the fourth expansion valve 35.

[0252] Then, the refrigerant can expand when passing through the fourth expansion valve 35, and can evaporate by exchanging heat with the coolant in the heat exchanger 13.

[0253] The refrigerant expanded in the heat exchanger 13 is supplied to the accumulator 17 along the first branch pipeline 25.

[0254] The refrigerant supplied to the accumulator 17 is separated into gas and liquid. The gaseous refrigerant in the refrigerant separated into gas and liquid is supplied to the compressor 19.

[0255] The refrigerant compressed into a high-temperature and high-pressure state in the compressor 19 flows into the internal condenser 12a.

[0256] Here, the refrigerant supplied to the internal condenser 12a can raise the temperature of the outside air flowing into the HVAC module 12.

[0257] The opening and closing door 12b is opened so that the outside air flowing into the HVAC module 12 and passing through the evaporator 16 passes through the internal condenser 12a.

[0258] Therefore, the outside air flowing in from the outside flows in at room temperature without being cooled when passing through the evaporator 16 without refrigerant supply. The flowing-in outside air is converted to a high-temperature state when passing through the internal condenser 12a and flows into the vehicle interior, thereby heating the vehicle interior.

[0259] Therefore, the present invention can improve the heating efficiency and performance while minimizing the use of a separate electric heater.

[0260] In addition, the gas injection device 30 can maximize the heating performance by increasing the flow rate of the refrigerant circulating in the refrigerant pipeline 11.

[0261] In various exemplary embodiments of the present invention, reference will be made to Figure 7 describe the operation when the gas injection device 30 is not operating in the dehumidification mode of the vehicle.

[0262] Figure 7 The operation state diagram showing the operation when the gas injection device is not operating in the dehumidification mode of the vehicle in the heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0263] Reference is made to Figure 7 such that the heat pump system can execute the dehumidification mode while heating the vehicle interior.

[0264] First, the coolant circulation device 3 supplies coolant to the heat exchanger 13 through the coolant pipeline 5 connected to the heat exchanger 13. In this case, the coolant pipeline 5 connected to the refrigerator 40 is closed.

[0265] In the air conditioning device 10, each component operates to heat and dehumidify the vehicle interior. Therefore, the refrigerant circulates along the refrigerant pipeline 11.

[0266] Here, the refrigerant pipeline 11 connecting the sub-condenser 14 and the evaporator 16 is closed by the operation of the first expansion valve 15.

[0267] The refrigerant connection pipeline 21 is closed by the operation of the second expansion valve 23.

[0268] Meanwhile, the first branch pipeline 25 is opened by the operation of the first refrigerant valve 24.

[0269] The second branch pipeline 27 is closed by the operation of the second refrigerant valve 26, and the third branch pipeline 29 is closed by the operation of the third refrigerant valve 28.

[0270] The fourth branch pipeline 51 is opened by the operation of the check valve 53.

[0271] In addition, the refrigerant pipeline 11 connecting the heat exchanger 13 and the sub-condenser 14 can be closed by the operation of the first refrigerant valve 24.

[0272] Here, when the gas injection device 30 is not operating, the supply pipeline 32 is closed by the operation of the control valve 33.

[0273] In addition, the third expansion valve 34 allows the refrigerant supplied from the internal condenser 12a to pass through.

[0274] The fourth expansion valve 35 can expand the refrigerant passing through the gas-liquid separator 31 and supply it to the heat exchanger 13.

[0275] Therefore, the heat exchanger 13 can evaporate the expanded refrigerant by exchanging heat with the coolant.

[0276] Meanwhile, the fourth branch pipeline 51 supplies a part of the refrigerant passing through the gas-liquid separator 31 to the first expansion valve 15.

[0277] Therefore, a part of the refrigerant flowing into the fourth branch pipeline 51 expands when passing through the first expansion valve 15. The expanded refrigerant flows into the evaporator 16.

[0278] The refrigerant evaporated in the heat exchanger 13 is supplied to the accumulator 17 along the first branch pipeline 25.

[0279] The refrigerant supplied to the accumulator 17 is separated into gas and liquid. The gaseous refrigerant in the refrigerant separated into gas and liquid is supplied to the compressor 19.

[0280] The refrigerant compressed into a high-temperature and high-pressure state in the compressor 19 flows into the internal condenser 12a.

[0281] Here, the refrigerant supplied to the internal condenser 12a can raise the temperature of the external air flowing into the HVAC module 12.

[0282] The opening and closing door 12b is opened so that the external air flowing into the HVAC module 12 and passing through the evaporator 16 passes through the internal condenser 12a.

[0283] Meanwhile, the external air flowing into the HVAC module 12 is dehumidified by the low-temperature refrigerant flowing into the evaporator 16 when passing through the evaporator 16. Then, it is converted to a high-temperature state when passing through the internal condenser 12a and flows into the vehicle interior, thereby heating and dehumidifying the vehicle interior.

[0284] That is, when the gas injection device 30 is not operating, the third expansion valve 34 allows the refrigerant supplied from the internal condenser 12a to pass through. The fourth expansion valve 35 expands the refrigerant passing through the gas-liquid separator 31 and supplies it to the heat exchanger 13. Here, the heat exchanger 13 can evaporate the refrigerant by exchanging heat with the coolant.

[0285] A part of the refrigerant passing through the gas-liquid separator 31 is supplied to the first expansion valve 15 and the evaporator 16 through the opened fourth branch pipeline 51.

[0286] Through such an operation, the outside air flowing into the HVAC module 12 is dehumidified by the low-temperature refrigerant flowing into the evaporator 16 when passing through the evaporator 16. Then, it is converted to a high-temperature state when passing through the internal condenser 12a and flows into the vehicle interior, thereby smoothly heating and dehumidifying the vehicle interior.

[0287] In various exemplary embodiments of the present invention, reference will be made to Figure 8 Describe the operation when the gas injection device 30 operates in the dehumidification mode of the vehicle.

[0288] Figure 8 The operation state diagram showing the operation of the gas injection device in the dehumidification mode of the vehicle in a heat pump system for a vehicle according to various exemplary embodiments of the present invention.

[0289] The heat pump system can execute the dehumidification mode while heating the vehicle interior.

[0290] First, the coolant circulation device 3 supplies the coolant to the heat exchanger 13 through the coolant pipeline 5 connected to the heat exchanger 13. In this case, the coolant pipeline 5 connected to the refrigerator 40 is closed.

[0291] In the air conditioning device 10, each component operates to heat and dehumidify the vehicle interior. Therefore, the refrigerant circulates along the refrigerant pipeline 11.

[0292] Here, the refrigerant pipeline 11 connecting the sub-condenser 14 and the evaporator 16 is closed by the operation of the first expansion valve 15.

[0293] The refrigerant connection pipeline 21 is closed by the operation of the second expansion valve 23.

[0294] At the same time, the first branch pipeline 25 is opened by the operation of the first refrigerant valve 24.

[0295] The second branch pipeline 27 is closed by the operation of the second refrigerant valve 26, and the third branch pipeline 29 is closed by the operation of the third refrigerant valve 28.

[0296] The fourth branch pipeline 51 is opened by the operation of the check valve 53.

[0297] In addition, the refrigerant pipeline 11 connecting the heat exchanger 13 and the sub-condenser 14 can be closed by the operation of the first refrigerant valve 24.

[0298] Here, when the gas injection device 30 operates, the supply pipeline 32 is opened by the operation of the control valve 33.

[0299] In this state, the third expansion valve 34 expands the refrigerant supplied from the internal condenser 12a and supplies it to the gas-liquid separator 31.

[0300] The gaseous refrigerant in the refrigerant supplied to the gas-liquid separator 31 is supplied to the compressor 19 through the opened supply line 32.

[0301] That is, the gas injection device 30 causes the gaseous refrigerant that has undergone heat exchange when passing through the gas-liquid separator 31 to flow back into the compressor 19 through the supply line 32, thereby increasing the flow rate of the refrigerant circulating in the refrigerant line 11.

[0302] In addition, the liquid refrigerant discharged from the gas-liquid separator 31 through the refrigerant line 11 flows into the heat exchanger 13 along the refrigerant line 11 opened by the operation of the fourth expansion valve 35.

[0303] The fourth expansion valve 35 expands the refrigerant that has passed through the gas-liquid separator 31.

[0304] Therefore, the heat exchanger 13 can evaporate the refrigerant by exchanging heat with the coolant.

[0305] That is, the gas-liquid separator 31 of the gas injection device 30 can bypass the gaseous refrigerant to the compressor 19 through the supply line 32, and can supply the liquid refrigerant to the fourth expansion valve 35.

[0306] Then, the refrigerant can expand when passing through the fourth expansion valve 35, and can be evaporated in the heat exchanger 13 by exchanging heat with the coolant.

[0307] At the same time, the fourth branch line 51 supplies a part of the refrigerant in the refrigerant that has passed through the gas-liquid separator 31 to the first expansion valve 15.

[0308] Therefore, a part of the refrigerant flowing into the fourth branch line 51 expands when passing through the first expansion valve 15. The expanded refrigerant flows into the evaporator 16.

[0309] The refrigerant evaporated in the heat exchanger 13 is supplied to the accumulator 17 along the first branch line 25.

[0310] The refrigerant supplied to the accumulator 17 is separated into gas and liquid. The gaseous refrigerant in the refrigerant separated into gas and liquid is supplied to the compressor 19.

[0311] The refrigerant compressed into a high-temperature and high-pressure state in the compressor 19 flows into the internal condenser 12a.

[0312] Here, the refrigerant supplied to the internal condenser 12a can raise the temperature of the external air flowing into the HVAC module 12.

[0313] The opening / closing door 12b is opened so that outside air flowing into the HVAC module 12 and passing through the evaporator 16 passes through the internal condenser 12a.

[0314] That is, the outside air flowing into the HVAC module 12 is dehumidified by the low-temperature refrigerant flowing into the evaporator 16 when passing through the evaporator 16. Therefore, it is converted to a high-temperature state when passing through the internal condenser 12a and flows into the vehicle interior, thereby smoothly heating and dehumidifying the vehicle interior.

[0315] Therefore, as described above, when applying the heat pump system for a vehicle according to an exemplary embodiment of the present invention, the temperature of the battery module can be controlled according to the vehicle mode by using one chiller 40 that exchanges heat between the refrigerant and the coolant, thereby simplifying the system.

[0316] In addition, according to an exemplary embodiment of the present invention, by effectively controlling the temperature of the battery module, the battery module can operate with optimal performance, and the total mileage of the vehicle can be increased by effectively managing the battery module.

[0317] In addition, according to an exemplary embodiment of the present invention, the cooling and heating performance can be maximized by selectively increasing the refrigerant flow rate in the cooling, heating, or dehumidifying mode of the vehicle by applying the gas injection device 30.

[0318] In addition, the present invention can reduce the manufacturing cost and weight by simplifying the entire system, and can improve the space utilization rate.

[0319] Although the present invention has been described in conjunction with exemplary embodiments that are currently considered to be practical exemplary embodiments of the present invention, it should be understood that the present invention is not limited to the included exemplary embodiments. On the other hand, it is intended to cover various modifications and equivalent claims and various alternatives and modifications thereof. The scope of the present invention is intended to be defined by the appended claims and their equivalents.

[0320] In various exemplary embodiments of the present invention, the controller is connected to at least one element of the heat pump system, such as the control valve 33, but not limited thereto, to control its operation.

[0321] In addition, terms related to a control device such as "controller", "control unit", "control device", or "control module" refer to a hardware device including a memory and a processor configured to execute one or more steps interpreted as an algorithmic structure. The memory stores the algorithmic steps, and the processor executes the algorithmic steps to perform one or more processes of the methods according to various exemplary embodiments of the present invention. The control device according to an exemplary embodiment of the present invention can be implemented by a non-volatile memory configured to store an algorithm for controlling the operation of various components of a vehicle or data on software commands for executing the algorithm and a processor configured to perform the above operations using the data stored in the memory. The memory and the processor can be separate chips. Alternatively, the memory and the processor can be integrated in a single chip. The processor can be implemented as one or more processors. The processor can include various logic circuits and arithmetic circuits, process data according to a program provided by the memory, and generate a control signal according to the processing result.

[0322] The control device can be at least one microprocessor operated by a predetermined program, and the predetermined program can include a series of commands for executing the methods included in the above various exemplary embodiments of the present invention.

[0323] The present invention can also be embodied as computer-readable code on a computer-readable recording medium. A computer-readable recording medium is any data storage device that can store data that can be subsequently read by a computer system. Examples of computer-readable recording media include hard disk drives (HDDs), solid state drives (SSDs), silicon disk drives (SDDs), read-only memories (ROMs), random access memories (RAMs), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc., and embodiments as carrier waves (e.g., transmitted via the Internet).

[0324] In various exemplary embodiments of the present invention, each of the above operations can be performed by a control device, and the control device can be configured by a plurality of control devices or an integrated single control device.

[0325] In various exemplary embodiments of the present invention, the control device can be implemented in the form of hardware or software, or can be implemented in a combination of hardware and software.

[0326] For purposes of explanation and to define the appended claims with precision, reference is made to the locations of the features of the exemplary embodiments shown in the figures and the terms “upper”, “lower”, “inner”, “outer”, “above”, “below”, “upward”, “downward”, “front”, “rear”, “behind”, “inner side”, “outer side”, “inward”, “outward”, “interior”, “exterior”, “within”, “outside”, “forward” and “backward” are used to describe such features. It will be further understood that the term “connected” or its derivatives refer to both direct and indirect connection.

[0327] In addition, the term “fixed connection” means that the members of the fixed connection always rotate at the same speed. In addition, the term “selectively connected” means that “when the selectively connected members are not combined with each other, the selectively connected members rotate individually; when the selectively connected members are combined with each other, the selectively connected members rotate at the same speed; when at least one of the selectively connected members is a fixed member and the remaining selectively connected members are combined with the fixed member, the selectively connected members are fixed”.

[0328] For purposes of illustration and description, the foregoing description of specific exemplary embodiments of the invention has been given. These descriptions are not intended to be exhaustive of the invention or to limit the invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described to explain certain principles of the invention and its practical application to enable others skilled in the art to implement and utilize the invention in its various exemplary embodiments and alternative forms and modifications. The scope of the invention is intended to be defined by the appended claims and their equivalents.

Claims

1. A heat pump system for a vehicle, comprising: An air conditioning device that circulates a refrigerant through a refrigerant pipeline; A coolant circulation device that circulates a coolant through a coolant pipeline; A refrigerator that is connected to the coolant circulation device through the coolant pipeline, is connected to the refrigerant pipeline through a refrigerant connection pipeline that is a part of the refrigerant pipeline, and controls the temperature of the selectively flowing coolant by exchanging heat between the coolant selectively flowing in from the coolant circulation device and the refrigerant supplied from the air conditioning device; And A gas injection device that is provided in the air conditioning device and increases the flow rate of the refrigerant circulating in the refrigerant pipeline by bypassing a part of the refrigerant in the refrigerant passing through an internal condenser connected to the refrigerant pipeline to the compressor, Wherein, a heat exchanger provided in the air conditioning device is connected to the coolant circulation device through the coolant pipeline so that the coolant is supplied from the coolant circulation device, Wherein, The heat pump system further includes a first branch pipeline. Based on the flow direction of the refrigerant, the first branch pipeline is connected to the refrigerant pipeline through a first refrigerant valve at the rear end of the heat exchanger, The air conditioning device includes: A heating, ventilation, and air conditioning (HVAC) module that includes an evaporator connected through the refrigerant pipeline and an opening and closing door that selectively allows outside air passing through the evaporator to flow into the internal condenser according to the cooling, heating, and dehumidifying modes of the vehicle; The heat exchanger, which is connected to the refrigerant pipeline and the coolant pipeline and exchanges heat between the refrigerant supplied through the refrigerant pipeline and the coolant supplied from the coolant circulation device through the coolant pipeline; A compressor that is connected between the evaporator and the heat exchanger through the refrigerant pipeline; A sub-condenser that is provided in the refrigerant pipeline between the heat exchanger and the evaporator; A first expansion valve that is provided in the refrigerant pipeline connecting the sub-condenser and the evaporator; A second expansion valve that is provided in the refrigerant connection pipeline; and A liquid receiver that is provided in the refrigerant pipeline between the evaporator and the compressor, A first end of the refrigerant connection pipeline is connected to the refrigerant pipeline between the sub-condenser and the first expansion valve, A second end of the refrigerant connection pipeline is connected to the refrigerant pipeline between the liquid receiver and the evaporator, A first end of the first branch pipeline is connected to the refrigerant pipeline between the heat exchanger and the sub-condenser through a first refrigerant valve, A second end of the first branch pipeline is connected to the liquid receiver, The gas injection device includes: A gas-liquid separator that is provided in the refrigerant pipeline between the internal condenser and the heat exchanger and separates and selectively discharges the gaseous refrigerant and the liquid refrigerant in the refrigerant passing through the internal condenser; A supply pipeline that connects the gas-liquid separator and the compressor and selectively supplies the gaseous refrigerant from the gas-liquid separator to the compressor, A control valve, disposed in the supply pipeline; A third expansion valve, disposed in the refrigerant pipeline between the internal condenser and the gas-liquid separator; and A fourth expansion valve, disposed in the refrigerant pipeline between the gas-liquid separator and the heat exchanger, The heat pump system for a vehicle further includes: A second branch pipeline, with the first end connected to a second refrigerant valve disposed in the refrigerant pipeline between the internal condenser and the compressor, and the second end connected to the refrigerant pipeline between the fourth expansion valve and the heat exchanger; A third branch pipeline, with the first end connected to a third refrigerant valve disposed in the refrigerant pipeline between the sub-condenser and the first expansion valve, and the second end connected to the refrigerant pipeline between the internal condenser and the third expansion valve; and A fourth branch pipeline, with the first end connected to the refrigerant pipeline between the gas-liquid separator and the fourth expansion valve, the second end connected to the refrigerant pipeline between the third refrigerant valve and the first expansion valve, and having a check valve in the fourth branch pipeline.

2. The heat pump system for a vehicle according to claim 1, wherein The second expansion valve selectively expands the refrigerant passing through the sub-condenser according to the mode of the vehicle among the cooling, heating, and dehumidifying modes of the vehicle and causes the expanded refrigerant to flow into the refrigerant connection pipeline.

3. The heat pump system for a vehicle according to claim 1, wherein When cooling the battery module in the cooling mode of the vehicle and the gas injection device operates, The coolant circulation device supplies coolant to the heat exchanger and the refrigerator through the coolant pipeline connecting the heat exchanger and the refrigerator; In the air conditioning device, The refrigerant connection pipeline is opened by the operation of the second expansion valve; The refrigerant pipeline connected to the first expansion valve is closed by the operation of the third refrigerant valve; The refrigerant pipeline connecting the internal condenser and the compressor is closed by the operation of the second refrigerant valve; The refrigerant circulates along the opened refrigerant pipeline and the refrigerant connection pipeline; The first expansion valve and the second expansion valve expand the refrigerant so that the expanded refrigerant is respectively supplied to the evaporator and the refrigerator; The first branch pipeline is closed; The second branch pipeline, the third branch pipeline, and the fourth branch pipeline are opened; The refrigerant pipeline connecting the heat exchanger and the sub-condenser is opened by the operation of the first refrigerant valve; The heat exchanger condenses the refrigerant by exchanging heat with the coolant; The sub-condenser further condenses the refrigerant by exchanging heat with external air; In the gas injection device, the supply pipeline is opened; The third expansion valve expands the refrigerant supplied through the third branch pipeline and supplies it to the gas-liquid separator; and The fourth expansion valve does not operate.

4. The heat pump system for a vehicle according to claim 1, wherein When cooling the battery module in the cooling mode of the vehicle and the gas injection device is not operating, the coolant circulation device supplies coolant to the heat exchanger and the refrigerator through the coolant pipeline connected to the heat exchanger and the refrigerator; In the air conditioning device, the refrigerant connection pipeline is opened by the operation of the second expansion valve; the refrigerant circulates along the refrigerant pipeline and the refrigerant connection pipeline; the first expansion valve and the second expansion valve expand the refrigerant so that the expanded refrigerant is respectively supplied to the evaporator and the refrigerator; the first branch pipeline, the second branch pipeline, the third branch pipeline and the fourth branch pipeline are closed; the refrigerant pipeline connecting the heat exchanger and the sub-condenser is opened by the operation of the first refrigerant valve; the heat exchanger condenses the refrigerant by heat exchange with the coolant; the sub-condenser further condenses the refrigerant by heat exchange with the external air; In the gas injection device, the supply pipeline is closed; and the third expansion valve and the fourth expansion valve cause the refrigerant supplied from the internal condenser to flow through the refrigerant pipeline without expansion.

5. The heat pump system for a vehicle according to claim 1, wherein, when the gas injection device operates in the heating mode of the vehicle, the supply pipeline is opened; the third expansion valve expands the refrigerant supplied from the internal condenser and supplies the expanded refrigerant to the gas-liquid separator; the fourth expansion valve expands the refrigerant supplied from the gas-liquid separator and supplies the expanded refrigerant to the heat exchanger; the first branch pipeline is opened by the operation of the first refrigerant valve; and the second branch pipeline, the third branch pipeline and the fourth branch pipeline are closed.

6. The heat pump system for a vehicle according to claim 1, wherein, when the gas injection device does not operate in the heating mode of the vehicle, the supply pipeline is closed; the third expansion valve allows the refrigerant supplied from the internal condenser to pass through; the fourth expansion valve expands the refrigerant passing through the gas-liquid separator and supplies the expanded refrigerant to the heat exchanger; the first branch pipeline is opened by the operation of the first refrigerant valve; and the second branch pipeline, the third branch pipeline and the fourth branch pipeline are closed.

7. The heat pump system for a vehicle according to claim 1, wherein, when the gas injection device does not operate in the dehumidification mode of the vehicle, the supply pipeline is closed; the third expansion valve allows the refrigerant supplied from the internal condenser to pass through; and the fourth expansion valve expands the refrigerant passing through the gas-liquid separator and supplies the expanded refrigerant to the heat exchanger; the first branch pipeline is opened by the operation of the first refrigerant valve; the second branch pipeline and the third branch pipeline are closed; and the fourth branch pipeline is opened.

8. The heat pump system for a vehicle according to claim 1, wherein, When the gas injection device operates in the dehumidification mode of the vehicle, the supply pipeline is opened; the third expansion valve expands the refrigerant supplied from the internal condenser and supplies the expanded refrigerant to the gas-liquid separator; the fourth expansion valve expands the refrigerant passing through the gas-liquid separator and supplies the expanded refrigerant to the heat exchanger; the first branch pipeline is opened by the operation of the first refrigerant valve; the second branch pipeline and the third branch pipeline are closed; and the fourth branch pipeline is opened.

9. The heat pump system for a vehicle according to claim 1, wherein when the gas injection device operates, the control valve operates to open the supply pipeline.

10. The heat pump system for a vehicle according to claim 1, wherein the second expansion valve, the third expansion valve and the fourth expansion valve are electronic expansion valves that selectively expand the refrigerant while controlling the flow of the refrigerant.

11. The heat pump system for a vehicle according to claim 1, wherein the heat exchanger further condenses or evaporates the refrigerant discharged from the gas-liquid separator by heat exchange with the coolant according to the selective operation of the fourth expansion valve.

12. The heat pump system for a vehicle according to claim 1, wherein in the heating mode of the vehicle, the coolant circulation device supplies coolant to the heat exchanger through the coolant pipeline connected to the heat exchanger; in the air conditioning device, the refrigerant pipeline connecting the sub-condenser and the evaporator is closed by the operation of the first expansion valve; the refrigerant connection pipeline is closed by the operation of the second expansion valve; the fourth expansion valve expands the refrigerant; the first branch pipeline is opened by the operation of the first refrigerant valve; the refrigerant pipeline connecting the heat exchanger and the sub-condenser is closed by the operation of the first refrigerant valve; the heat exchanger evaporates the refrigerant by heat exchange with the coolant; and the gas injection device operates selectively.

13. The heat pump system for a vehicle according to claim 1, wherein in the dehumidification mode of the vehicle, the coolant circulation device supplies the coolant to the heat exchanger through the coolant pipeline connected to the heat exchanger; in the air conditioning device, the refrigerant pipeline connecting the sub-condenser and the evaporator is closed by the operation of the first expansion valve; the refrigerant connection pipeline is closed by the operation of the second expansion valve; the first branch pipeline is opened by the operation of the first refrigerant valve; the refrigerant pipeline connecting the heat exchanger and the sub-condenser is closed by the operation of the first refrigerant valve; the heat exchanger evaporates the refrigerant by heat exchange with the coolant; the fourth branch pipeline is opened by the operation of the check valve; and the gas injection device operates selectively.

14. The heat pump system for a vehicle according to claim 1, wherein The gas injection device includes: a plate heat exchanger disposed in the refrigerant pipeline between the heat exchanger and the internal condenser; a supply pipeline including a first end connected to the refrigerant pipeline between the internal condenser and the plate heat exchanger and a second end connected to the compressor through the plate heat exchanger; a third expansion valve disposed in the supply pipeline at the front end of the plate heat exchanger; and a fourth expansion valve disposed in the refrigerant pipeline between the plate heat exchanger and the heat exchanger.

15. The heat pump system for a vehicle according to claim 1, wherein the heat exchanger is a water-cooled heat exchanger; and the sub-condenser is an air-cooled heat exchanger.

16. The heat pump system for a vehicle according to claim 1, wherein the gas injection device operates selectively in the cooling, heating or dehumidifying mode of the vehicle.

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