Heat pump system for vehicle

Abstract

A heat pump system for a vehicle includes: an air conditioning unit including a compressor, a first heat exchanger, a second heat exchanger, a first expansion valve, and a third heat exchanger connected through a refrigerant line to circulate refrigerant through the refrigerant line; and a cooler connected to the refrigerant line through a first connection line and adjusting a temperature of the coolant by heat exchanging the refrigerant supplied from the air conditioning unit with the coolant, in which the air conditioning unit further includes: a first valve provided in the refrigerant line between the first heat exchanger and the second heat exchanger; a second valve provided in the refrigerant line between the third heat exchanger and the compressor; a second expansion valve provided in the first connection line; the first end of the second connecting pipeline is connected to the refrigerant pipeline between the first heat exchanger and the second heat exchanger, and the second end of the second connecting pipeline is connected to the refrigerant pipeline between the second heat exchanger and the third heat exchanger; and a third expansion valve.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0118415 filed in the Korean Intellectual Property Office on September 6, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a heat pump system for a vehicle, and more particularly to a heat pump system for a vehicle that can cool or heat the interior of a vehicle by using a natural refrigerant and effectively adjust the temperature of a battery module by using a single cooler in which a refrigerant and a coolant perform heat exchange. Background Art

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

[0005] The air conditioning unit is used to maintain the interior of the vehicle at a suitable temperature regardless of external temperature changes. The air conditioning unit is configured to heat or cool the interior of the vehicle by causing the condenser and the evaporator to exchange heat in the process in which the refrigerant discharged by driving the compressor passes through the condenser, the liquid receiver dryer, the expansion valve and the evaporator and circulates back to the compressor.

[0006] In other words, the air conditioning unit condenses the high-temperature and high-pressure gas-phase refrigerant compressed from the compressor through the condenser, passes the refrigerant through the receiver-drier and the expansion valve, and then evaporates the refrigerant in the evaporator in the cooling mode, thereby reducing the temperature and humidity inside the vehicle.

[0007] Environmental protection technology of vehicles is the core technology of the future automobile industry, and advanced automobile manufacturers have focused their efforts on the development of environmentally friendly vehicles to cope with environmental protection and fuel efficiency regulations.

[0008] Recently, with the increasing concern about energy efficiency and environmental pollution issues, there is a need to develop environmentally friendly vehicles that can basically replace internal combustion engine vehicles. Environmentally friendly vehicles are divided into electric vehicles driven using fuel cells or electricity as a power source, and hybrid vehicles driven using an engine and a battery.

[0009] Electric vehicles have attracted much attention as a means of transportation to solve environmental and energy problems in the future.

[0010] Heat pump systems, which are air conditioning devices used to regulate the temperature inside a vehicle, are suitable for such electric vehicles.

[0011] However, refrigerants conventionally used in heat pump systems contain a large amount of environmentally regulated substances such as PFAS (perfluoroalkyl and polyfluoroalkyl substances), and therefore there is a need to develop a system that can control the temperature inside a vehicle by using a new refrigerant (which does not contain PFAS or flammability), or a natural refrigerant.

[0012] The above information disclosed in the Background section is only for enhancing understanding of the background of the invention. Therefore, the Background section may contain information that does not constitute the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0013] The present invention intends to provide a heat pump system for a vehicle that can cool or heat the interior of the vehicle by using a natural refrigerant and effectively adjust the temperature of a battery module to comply with environmental regulations by using a single cooler in which the refrigerant and the coolant perform heat exchange.

[0014] In addition, the present invention intends to provide a heat pump system for a vehicle, which can maximize cooling and heating performance by applying R744 refrigerant (which is a natural refrigerant using carbon dioxide) to operate in a supercritical cycle, wherein the supercritical cycle refers to a state in which the pressure and temperature of the refrigerant are higher than a threshold pressure and temperature.

[0015] A heat pump system for a vehicle may include: an air conditioning unit including a compressor, a first heat exchanger, a second heat exchanger, a first expansion valve, and a third heat exchanger, which are connected by a refrigerant line so that the refrigerant circulates through the refrigerant line; and a cooler connected to the refrigerant line through a first connecting line. The cooler is configured to adjust the temperature of the coolant by exchanging heat between the refrigerant supplied from the air conditioning unit and the coolant. The air conditioning unit also includes: a first valve disposed in the refrigerant line between the first heat exchanger and the second heat exchanger; a second valve disposed in the refrigerant line between the third heat exchanger and the compressor; a second expansion valve disposed in the first connecting line; a second connecting line, a first end of which is connected to the refrigerant line between the first heat exchanger and the second heat exchanger, and a second end of which is connected to the refrigerant line between the second heat exchanger and the third heat exchanger; and a third expansion valve disposed in the second connecting line.

[0016] The air conditioning unit also includes: a third connecting line, a first end of which is connected to the refrigerant line between the compressor and the first heat exchanger, and a second end of which is connected to the refrigerant line between the first heat exchanger and the second heat exchanger; a third valve, which is arranged in the third connecting line; a fourth connecting line, a first end of which is connected to the refrigerant line between the second heat exchanger and the third heat exchanger, and a second end of which is connected to the refrigerant line between the third heat exchanger and the compressor; a fourth expansion valve, which is arranged in the fourth connecting line; a fifth connecting line, a first end of which is connected to the refrigerant line between the third heat exchanger and the compressor, and a second end of which is connected to the refrigerant line between the first heat exchanger and the second heat exchanger; and a fourth valve, which is arranged in the fifth connecting line.

[0017] The air conditioning unit also includes: a liquid accumulator, which is arranged in the refrigerant pipeline between the third heat exchanger and the compressor; and an internal heat exchanger, which is arranged inside the liquid accumulator and is configured to cause the refrigerant supplied from the second heat exchanger and the refrigerant supplied from the third heat exchanger to exchange heat with each other, and supply liquid refrigerant in the heat-exchanged refrigerant to the third heat exchanger.

[0018] In the heating mode of the vehicle interior: a portion of the refrigerant line connecting the first end of the first connecting line and the second end of the second connecting line is closed by the operation of the first expansion valve. A portion of the refrigerant line connecting the first end of the second connecting line and the second end of the fifth connecting line is closed by the operation of the first valve. A portion of the refrigerant line connecting the second end of the fourth connecting line and the second end of the first connecting line is closed by the operation of the second valve. The first connecting line is opened by the operation of the second expansion valve. The second connecting line is opened by the operation of the third expansion valve. The third connecting line is closed by the operation of the third valve. The fourth connecting line is opened by the operation of the fourth expansion valve. The fifth connecting line is opened by the operation of the fourth valve.

[0019] The fourth expansion valve is configured to expand the refrigerant so that the expanded refrigerant is supplied to the second heat exchanger, the internal heat exchanger, and the cooler, respectively.

[0020] A portion of the refrigerant flowing from the third heat exchanger into the fourth connecting line flows into the second heat exchanger, and the remaining refrigerant flowing from the third heat exchanger into the fourth connecting line flows into the internal heat exchanger.

[0021] A portion of the refrigerant discharged from the fourth expansion valve passes through the internal heat exchanger along the refrigerant line and then flows into the cooler. The refrigerant discharged from the second heat exchanger and the cooler passes through the internal heat exchanger and the accumulator and then is supplied to the compressor.

[0022] The second expansion valve supplies the refrigerant introduced through the first connecting line to the cooler without expansion, and the third expansion valve supplies the refrigerant introduced through the second connecting line to the third heat exchanger without expansion.

[0023] In the heating and dehumidification mode of the vehicle interior: a portion of the refrigerant line connecting the first end of the first connecting line and the second end of the second connecting line is opened by the operation of the first expansion valve. A portion of the refrigerant line connecting the first end of the second connecting line and the second heat exchanger is closed by the operation of the first valve. The refrigerant line connecting the third heat exchanger and the accumulator is opened by the operation of the second valve. The refrigerant line connecting the second heat exchanger and the internal heat exchanger is closed. The first connecting line is opened by the operation of the second expansion valve. The second connecting line is opened by the operation of the third expansion valve. The third connecting line is closed by the operation of the third valve. The fourth connecting line is closed by the operation of the fourth expansion valve. The fifth connecting line is closed by the operation of the fourth valve.

[0024] The third expansion valve is configured to expand the refrigerant introduced from the first heat exchanger through the second connecting line and supply the expanded refrigerant to the third heat exchanger and the cooler, respectively.

[0025] The first expansion valve and the second expansion valve are configured to flow the introduced refrigerant without expansion.

[0026] When the battery module needs to be cooled in the cooling mode inside the vehicle: a portion of the refrigerant line connecting the compressor and the first heat exchanger and a portion of the refrigerant line connecting the first heat exchanger and the second heat exchanger are closed by the operation of the first valve. The first connecting line is opened by the operation of the second expansion valve. The second connecting line is closed by the operation of the third expansion valve. The third connecting line is opened by the operation of the third valve. The fourth connecting line is closed by the operation of the fourth expansion valve. The fifth connecting line is closed by the operation of the fourth valve.

[0027] The first expansion valve is configured to expand the refrigerant introduced through the refrigerant line and flow the expanded refrigerant to the third heat exchanger. The second expansion valve is configured to expand the refrigerant introduced into the first connecting line and flow the expanded refrigerant to the cooler so as to cool the battery module by using the coolant that exchanges heat with the refrigerant in the cooler.

[0028] The refrigerant discharged from the compressor flows into the second heat exchanger along the third connecting line. A portion of the refrigerant discharged from the internal heat exchanger flows into the cooler along the first connecting line. The remaining refrigerant discharged from the internal heat exchanger flows into the first expansion valve along the refrigerant line. The refrigerant discharged from the cooler and the refrigerant discharged from the third heat exchanger pass through the internal heat exchanger and the accumulator along the refrigerant line and are then supplied to the compressor.

[0029] The second heat exchanger and the third heat exchanger are configured to cool or evaporate the refrigerant introduced into the inside.

[0030] The first end of the first connecting line is connected to the refrigerant line between the second heat exchanger and the first expansion valve. The second end of the first connecting line is connected to the refrigerant line between the third heat exchanger and the compressor.

[0031] The refrigerant is R744 refrigerant formed from carbon dioxide.

[0032] The cooler is connected to the electric components and the battery module through first and second lines, respectively, through which a coolant circulates.

[0033] The first heat exchanger, the second heat exchanger, and the third heat exchanger are air-cooled gas coolers configured to exchange heat between the refrigerant introduced into the interior and the air. The cooler is a water-cooled gas cooler configured to exchange heat between the refrigerant introduced into the interior and the coolant.

[0034] The first expansion valve, the second expansion valve, the third expansion valve, and the fourth expansion valve are electronic expansion valves configured to selectively expand the refrigerant while controlling the flow of the refrigerant.

[0035] The first valve, the second valve, the third valve and the fourth valve may be two-way valves.

[0036] As described above, by adopting the heat pump system for a vehicle according to one embodiment, since the interior of the vehicle is cooled or heated by using a natural refrigerant, it is possible to cope with environmental regulations and improve the overall marketability of the vehicle.

[0037] In addition, according to the present invention, by applying R744 refrigerant, which is a natural refrigerant using carbon dioxide, the cooling and heating performance can be maximized by operating in a supercritical region, which is a state where the pressure and temperature of the refrigerant are higher than a threshold pressure and temperature, for cooling and heating the interior of a vehicle.

[0038] Furthermore, according to the present invention, by effectively adjusting the temperature of the battery module using a single cooler that performs heat exchange of a coolant and a refrigerant according to a vehicle mode, it is possible to achieve downsizing and simplification of the system.

[0039] Furthermore, according to one embodiment, by effectively regulating the temperature of the battery module, optimal performance of the battery module may be achieved, and the overall driving range of the vehicle may be increased due to the efficient management of the battery module.

[0040] Furthermore, according to the present invention, in the heating mode inside the vehicle, since the refrigerant expands and is diverted to each heat exchanger, the flow rate of the refrigerant is easily controlled, the ambient air heat and the waste heat of the electrical components can be smoothly recovered, and the cooler for cooling the battery module can be optimally designed.

[0041] Furthermore, according to the embodiments, manufacturing cost and weight can be reduced, and space utilization can be improved by simplifying the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a block diagram of a heat pump system for a vehicle according to an embodiment;

[0043] Figure 2 is an operation diagram of a heat pump system for a vehicle in a heating mode of a vehicle interior according to an embodiment;

[0044] Figure 3 is an operation diagram of a heat pump system for a vehicle in a heating and dehumidification mode of a vehicle interior according to an embodiment;

[0045] Figure 4 is an operation diagram of cooling a battery module in a cooling mode inside a vehicle according to an embodiment of the heat pump system for a vehicle.

[0046] Description of reference numerals:

[0047] 2, 4: First pipeline, second pipeline

[0048] 3: Electrical components

[0049] 5: Battery module

[0050] 10: Compressor

[0051] 11: Refrigerant pipeline

[0052] 12: HVAC module

[0053] 13, 14, 16: the first heat exchanger, the second heat exchanger and the third heat exchanger

[0054] 15: First expansion valve

[0055] 17: Liquid reservoir

[0056] 17a: Internal heat exchanger

[0057] 20: Cooler

[0058] 21: First connecting pipeline

[0059] 23: Second expansion valve

[0060] 31: Second connecting pipeline

[0061] 33: The third expansion valve

[0062] 41: Third connecting pipeline

[0063] 43: The third valve

[0064] 51: Fourth connecting pipeline

[0065] 53: Fourth expansion valve

[0066] 61: Fifth connecting pipeline

[0067] 63: The fourth valve DETAILED DESCRIPTION

[0068] Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0069] The exemplary embodiments disclosed in this specification and the configurations shown in the drawings are only some embodiments of the present invention and do not cover the entire scope of the present invention. Therefore, it should be understood that various equivalents and modifications may exist in various embodiments of the present invention.

[0070] In order to clarify the present invention, parts that are not related to the description are omitted, and the same reference numerals are used throughout the specification to designate the same or equivalent elements.

[0071] In addition, the size and thickness of each element are arbitrarily shown in the drawings, but the present invention is not necessarily limited thereto. In addition, in the drawings, the thickness of layers, films, panels, regions, etc. are exaggerated for clarity.

[0072] In addition, unless explicitly described to the contrary, the term “comprise” and terms such as “include” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0073] In addition, each term described in the specification, such as “unit,” “means,” “portion,” “section,” and “member,” refers to a unit of a comprehensive element that performs at least one function or operation.

[0074] Figure 1 is a block diagram of a heat pump system for a vehicle according to one embodiment.

[0075] According to a heat pump system for a vehicle of one embodiment, the vehicle interior may be cooled or heated by using a natural refrigerant and the temperature of the battery module 5 may be effectively adjusted to comply with environmental regulations by using a single cooler 20 that performs heat exchange between the refrigerant and the coolant.

[0076] The refrigerant may be R744 refrigerant formed of carbon dioxide, which has an ozone depletion potential (ODP) of 0 and a global warming potential (GWP) of 1.

[0077] In other words, by applying R744 refrigerant, which is a natural refrigerant using carbon dioxide, a heat pump system for a vehicle according to one embodiment can maximize cooling and heating performance by operating in a supercritical cycle, which refers to a state in which the pressure and temperature of the refrigerant are higher than a threshold pressure and temperature.

[0078] To this end, the heat pump system according to one embodiment may include an air conditioning unit and a chiller 20 .

[0079] refer to Figure 1 The air conditioning unit may include a compressor 10, a first heat exchanger 13, a second heat exchanger 14, a third heat exchanger 16, a liquid reservoir 17, and an internal heat exchanger 17a, which are connected to each other through a refrigerant line 11 so that the refrigerant circulates through the refrigerant line 11.

[0080] First, the compressor 10 may compress introduced refrigerant and flow the compressed refrigerant to the refrigerant line 11 , allowing the refrigerant to circulate along the refrigerant line 11 .

[0081] The first heat exchanger 13 may perform heat exchange between the refrigerant selectively supplied from the compressor 10 and the air.

[0082] The second heat exchanger 14 may be connected to the first heat exchanger 13 through the refrigerant line 11. Therefore, the refrigerant supplied to the refrigerant line 11 may pass through the second heat exchanger 14.

[0083] The second heat exchanger 14 may be disposed at the front side of the vehicle, and may cool or evaporate the refrigerant by exchanging heat with air introduced from the outside during driving of the vehicle.

[0084] Since R744 refrigerant is a supercritical refrigerant, unlike other refrigerants, it does not undergo phase change, so it is called a gas cooling refrigerant rather than a condensing refrigerant.

[0085] In the present embodiment, the first expansion valve 15 may be provided in the refrigerant line 11 between the second heat exchanger 14 and the third heat exchanger 16. The first expansion valve 15 may selectively expand the refrigerant introduced through the refrigerant line 11.

[0086] In addition, a third heat exchanger 16 may be provided in the refrigerant line 11 between the first expansion valve 15 and the compressor 10 .

[0087] The first heat exchanger 13 and the third heat exchanger 16 may be disposed inside a heating, ventilation, and air conditioning (HVAC) module 12 .

[0088] Therefore, the third heat exchanger 16 may cool or evaporate the refrigerant by exchanging heat with the air introduced into the HVAC module 12 .

[0089] In other words, the first heat exchanger 13 , the second heat exchanger 14 , and the third heat exchanger 16 may be air-cooled gas coolers configured to exchange heat between the refrigerant introduced into the inside and the air.

[0090] The second heat exchanger 14 and the third heat exchanger 16 may evaporate the refrigerant when expanded refrigerant is introduced, and cool the refrigerant when unexpanded refrigerant is introduced.

[0091] In the present embodiment, the accumulator 17 may be disposed in the refrigerant line 11 between the third heat exchanger 16 and the compressor 10 .

[0092] The accumulator 17 supplies only gaseous refrigerant to the compressor 10 , thereby improving the efficiency and durability of the compressor 10 .

[0093] In addition, an internal heat exchanger 17a may be provided inside the accumulator 17. The internal heat exchanger 17a may heat-exchange the refrigerant supplied from the second heat exchanger 14 and the refrigerant supplied from the third heat exchanger 16 with each other, and may supply liquid refrigerant of the heat-exchanged refrigerants to the third heat exchanger 16.

[0094] In other words, the internal heat exchanger 17a may heat-exchange the refrigerant cooled from the second heat exchanger 14 with the low-temperature refrigerant discharged from the third heat exchanger 16 and supply the heat-exchanged refrigerant to the compressor 10 and the third heat exchanger 16, respectively.

[0095] In the present embodiment, the cooler 20 may be connected to the electric component 3 through the first pipeline 2 through which the coolant circulates.

[0096] The electrical components 3 may include an electric power control unit (EPCU), power conversion equipment (such as a motor, an inverter, an on-board charger (OBC), etc.), an automatic driving controller, etc.

[0097] The electric component 3 thus configured can be water-cooled by being connected to the first line 2 .

[0098] The cooler 20 may adjust the temperature of the electric component 3 by using the coolant that exchanges heat with the refrigerant, and recover waste heat of the electric component 3 .

[0099] In addition, the cooler 20 may be connected to the battery module 5 through the second line 4 through which the coolant circulates. Therefore, the coolant may selectively circulate through the inside of the cooler 20.

[0100] The cooler 20 may heat-exchange the refrigerant supplied from the air conditioning unit with the coolant, thereby adjusting the temperature of the coolant. In other words, the cooler 20 may be a water-cooled gas cooler configured to heat-exchange the refrigerant introduced inside with the coolant.

[0101] The cooler 20 may be connected to the refrigerant line 11 through a first connecting line 21 .

[0102] A first end of the first connecting line 21 may be connected to the refrigerant line 11 between the second heat exchanger 14 and the first expansion valve 15. Also, a second end of the first connecting line 21 may be connected to the refrigerant line 11 between the third heat exchanger 16 and the accumulator 17.

[0103] In other words, the cooler 20 may perform heat exchange between the coolant selectively introduced through the first line 2 or the second line 4 and the refrigerant selectively supplied from the air conditioning unit to adjust the temperature of the coolant.

[0104] Therefore, the coolant that has undergone heat exchange in the cooler 20 may circulate through the electric component 3 through the first line 2. Furthermore, the coolant that has undergone heat exchange in the cooler 20 may circulate through the battery module 5 through the second line 4.

[0105] A water pump (not shown) may be provided in the first pipeline 2 and the second pipeline 4 .

[0106] In other words, the coolant may circulate in the first line 2 and the second line 4 according to the operation of each water pump (not shown).

[0107] Therefore, the coolant that exchanges heat with the refrigerant in the cooler 20 may be selectively supplied to the electric components 3 and the battery modules 5 , thereby adjusting the temperatures of the electric components 3 and the battery modules 5 .

[0108] In this embodiment, the air conditioning unit may also include a first valve 18, a second valve 19, a second expansion valve 23, a second connecting pipeline 31, a third expansion valve 33, a third connecting pipeline 41, a third valve 43, a fourth connecting pipeline 51, a fourth expansion valve 53, a fifth connecting pipeline 61 and a fourth valve 63.

[0109] The first valve 18 may be disposed in the refrigerant line 11 between the first heat exchanger 13 and the second heat exchanger 14 .

[0110] The first valve 18 may selectively open and close the refrigerant line 11 so that the refrigerant discharged from the first heat exchanger 13 can be selectively introduced into the second heat exchanger 14 .

[0111] In the present embodiment, the second valve 19 may be provided in the refrigerant line 11 between the third heat exchanger 16 and the compressor 10. In more detail, the second valve 19 may be provided in the refrigerant line 11 between the third heat exchanger 16 and the accumulator 17.

[0112] The second valve 19 may open the refrigerant line 11 so that the refrigerant discharged from the third heat exchanger 16 can flow into the accumulator 17. Conversely, the second valve 19 may close the refrigerant line 11 so that the refrigerant discharged from the third heat exchanger 16 does not flow into the accumulator 17.

[0113] In other words, in the case of a heating mode of the vehicle interior, the second valve 19 may close the refrigerant line 11 so that the refrigerant exhausted from the third heat exchanger 16 does not flow into the accumulator 17 .

[0114] On the other hand, in the vehicle interior cooling mode or the vehicle interior heating and dehumidification mode, the second valve 19 may open the refrigerant line 11 so that the refrigerant exhausted from the third heat exchanger 16 may flow into the accumulator 17 .

[0115] The second expansion valve 23 may be provided in the first connecting line 21 .

[0116] The second expansion valve 23 may selectively expand the refrigerant introduced into the first connecting line 21 based on a cooling mode or a heating mode of the vehicle interior, and flow the selectively expanded refrigerant to the cooler 20 .

[0117] In addition, the second expansion valve 23 may supply the refrigerant introduced into the first connecting line 21 to the cooler 20 without expansion, or may close the first connecting line 21 so that the refrigerant is not supplied to the cooler 20 .

[0118] In more detail, when cooling the battery module 5 by using the coolant that performs heat exchange with the refrigerant in the cooler 20, the second expansion valve 23 may open the first connection line 21. At the same time, the second expansion valve 23 may expand the refrigerant introduced into the first connection line 21 and allow the expanded refrigerant to flow to the cooler 20.

[0119] In other words, the second expansion valve 23 may expand the refrigerant discharged from the second heat exchanger 14 to reduce the temperature and allow the expanded refrigerant to flow to the cooler 20 , thereby further reducing the temperature of the coolant flowing through the inside of the cooler 20 .

[0120] Therefore, by causing the coolant having a relatively low temperature to flow while passing through the cooler 20 , the battery module 5 can be cooled more effectively.

[0121] In this embodiment, a first end of the second connecting line 31 may be connected to the refrigerant line 11 between the first heat exchanger 13 and the second heat exchanger 14. A second end of the second connecting line 31 may be connected to the refrigerant line 11 between the second heat exchanger 14 and the third heat exchanger 16.

[0122] The third expansion valve 33 may be provided in the second connection line 31. The third expansion valve 33 may selectively open and close the second connection line 31, and may selectively expand the refrigerant introduced into the second connection line 31.

[0123] In a cooling mode of the vehicle interior, the third expansion valve 33 may close the second connecting line 31. On the other hand, in a heating mode of the vehicle interior, the third expansion valve 33 may open the second connecting line 31.

[0124] In addition, in the heating and dehumidification mode of the vehicle interior, the third expansion valve 33 may open the second connecting line 31 and may expand the refrigerant introduced into the second connecting line 31 .

[0125] In other words, the third expansion valve 33 may selectively expand the refrigerant while controlling the flow of the refrigerant.

[0126] In this embodiment, a first end of the third connection line 41 may be connected to the refrigerant line 11 between the compressor 10 and the first heat exchanger 13. A second end of the third connection line 41 may be connected to the refrigerant line 11 between the first heat exchanger 13 and the second heat exchanger 14.

[0127] The third valve 43 may be provided in the third connecting line 41. The third valve 43 may selectively open and close the third connecting line 41.

[0128] In other words, in the vehicle interior cooling mode, the third valve 43 may open the third connecting line 41. On the other hand, in the vehicle interior heating mode and the vehicle interior heating and dehumidifying mode, the third valve 43 may close the third connecting line 41.

[0129] A first end of the fourth connection line 51 may be connected to the refrigerant line 11 between the second heat exchanger 14 and the third heat exchanger 16. A second end of the fourth connection line 51 may be connected to the refrigerant line 11 between the third heat exchanger 16 and the accumulator 17.

[0130] A fourth expansion valve 53 may be provided in the fourth connecting line 51 .

[0131] The fourth expansion valve 53 may control the flow of the refrigerant by selectively opening and closing the fourth connecting line 51 , and may selectively expand the refrigerant introduced into the fourth connecting line 51 .

[0132] In other words, in the vehicle interior heating mode, the fourth expansion valve 53 may open the fourth connecting line 51 and may expand the refrigerant introduced into the fourth connecting line 51 and supply the expanded refrigerant to the second heat exchanger 14 and the interior heat exchanger 17a, respectively.

[0133] Therefore, in the heating mode of the vehicle interior, the second heat exchanger 14 may evaporate the refrigerant by exchanging heat with the air introduced from the outside.

[0134] The refrigerant having passed through the internal heat exchanger 17a may be supplied to the cooler 20. The cooler 20 may evaporate the refrigerant by exchanging heat with the coolant supplied through the first line 2.

[0135] On the contrary, in the cooling mode of the vehicle interior or the heating and dehumidifying mode of the vehicle interior, the fourth expansion valve 53 may close the fourth connecting line 51 .

[0136] In this embodiment, a first end of the fifth connection line 61 may be connected to the refrigerant line 11 between the third heat exchanger 16 and the compressor 10. A second end of the fifth connection line 61 may be connected to the refrigerant line 11 between the first heat exchanger 13 and the second heat exchanger 14.

[0137] In addition, a fourth valve 63 may be provided in the fifth connecting line 61. The fourth valve 63 may control the flow of the refrigerant by selectively opening and closing the fifth connecting line 61.

[0138] In the vehicle interior cooling mode or the vehicle interior heating and dehumidification mode, the fourth valve 63 may close the fifth connecting line 61. Conversely, in the case of the vehicle interior heating mode, the fourth valve 63 may open the fifth connecting line 61.

[0139] The first valve 18 , the second valve 19 , the third valve 43 , and the fourth valve 63 may each be a two-way valve that controls opening and closing of the refrigerant line 11 , the third connecting line 41 , and the fifth connecting line 61 .

[0140] In addition, the first expansion valve 15 , the second expansion valve 23 , the third expansion valve 33 , and the fourth expansion valve 53 may each be an electronic expansion valve that selectively expands the refrigerant while controlling the flow of the refrigerant.

[0141] In the following, reference will be made to Figure 2-4 The operation and action of the heat pump system for a vehicle according to the embodiment configured as described above are described in detail.

[0142] First, refer to Figure 2 Operation in a heating mode of the vehicle interior is described.

[0143] Figure 2 is an operation diagram of a heat pump system for a vehicle in a heating mode of a vehicle interior according to an embodiment.

[0144] refer to Figure 2 , the coolant may circulate through the first pipeline 2 by operation of a water pump (not shown).

[0145] Therefore, the coolant having passed through the electric component 3 may be supplied to the cooler 20 along the first line 2 .

[0146] The various components in the air conditioning unit may be used to heat the interior of the vehicle. Therefore, the refrigerant may circulate along the refrigerant line 11.

[0147] A portion of the refrigerant line 11 connecting the first end of the first connection line 21 and the second end of the second connection line 31 may be closed by the operation of the first expansion valve 15 .

[0148] A portion of the refrigerant line 11 connecting the first end of the second connecting line 31 and the second end of the fifth connecting line 61 may be closed by the operation of the first valve 18 .

[0149] In addition, a portion of the refrigerant line 11 connecting the second end of the fourth connecting line 51 and the second end of the first connecting line 21 may be closed by the operation of the second valve 19 .

[0150] Meanwhile, the first connecting line 21 may be opened by the operation of the second expansion valve 23. The second expansion valve 23 may supply the refrigerant introduced through the first connecting line 21 to the cooler 20 without expansion.

[0151] The second connecting line 31 may be opened by operation of the third expansion valve 33. The third expansion valve 33 may supply the refrigerant introduced through the second connecting line 31 to the third heat exchanger 16 without expansion.

[0152] Therefore, the first heat exchanger 13 and the third heat exchanger 16 may cool the refrigerant by using the air introduced into the HVAC module 12 .

[0153] In the present embodiment, the third connection line 41 may be closed by the operation of the third valve 43. The fourth connection line 51 may be opened by the operation of the fourth expansion valve 53.

[0154] Therefore, a portion of the refrigerant flowing into the fourth connecting line 51 from the third heat exchanger 16 may flow into the second heat exchanger 14 .

[0155] Meanwhile, the remaining refrigerant among the refrigerant flowing into the fourth connecting line 51 from the third heat exchanger 16 may flow into the internal heat exchanger 17 a along the refrigerant line 11 .

[0156] The fourth expansion valve 53 may expand the refrigerant so that the expanded refrigerant is supplied to the second heat exchanger 14 , the internal heat exchanger 17 a , and the cooler 20 , respectively.

[0157] Therefore, the second heat exchanger 14 may evaporate the expanded refrigerant by exchanging heat with the air introduced from the outside. The second heat exchanger 14 may recover ambient air heat while evaporating the expanded refrigerant by exchanging heat with the air.

[0158] In addition, the cooler 20 may evaporate the expanded refrigerant by exchanging heat with the coolant supplied through the first line 2. The cooler 20 may recover waste heat of the electric components 3 from the coolant heated by recovering the waste heat from the electric components 3.

[0159] In addition, the fifth connecting line 61 may be opened by the operation of the fourth valve 63 .

[0160] Therefore, the refrigerant discharged from the second heat exchanger 14 may flow along the fifth connecting line 61 , and the refrigerant discharged from the cooler 20 may flow along the first connecting line 21 .

[0161] The refrigerant flowing through the first and fifth connecting lines 21 and 61 may pass through the internal heat exchanger 17 a and the accumulator 17 along the refrigerant line 11 and then be supplied to the compressor 10 .

[0162] In other words, a portion of the refrigerant expanded from the fourth expansion valve 53 may pass through the internal heat exchanger 17 a along the refrigerant line 11 and then flow into the cooler 20 .

[0163] In addition, the refrigerant discharged from the second heat exchanger 14 and the cooler 20 may pass through the internal heat exchanger 17 a and the accumulator 17 and then be supplied to the compressor 10 .

[0164] In this state, the refrigerant supplied from the compressor 10 may flow into the first heat exchanger 13 along the refrigerant line 11. The refrigerant having passed through the first heat exchanger 13 may flow along the second connection line 31 connected to the refrigerant line 11.

[0165] The refrigerant flowing along the second connecting line 31 may flow into the third heat exchanger 16 along the refrigerant line 11 connected to the third heat exchanger 16 .

[0166] The first heat exchanger 13 and the third heat exchanger 16 may cool the refrigerant by exchanging heat between the refrigerant and the air introduced into the HVAC module 12. The refrigerant preliminarily cooled in the first heat exchanger 13 may be additionally cooled in the third heat exchanger 16.

[0167] In other words, when the refrigerant having passed through the first heat exchanger 13 is supplied to the third heat exchanger 16 without being expanded by operation of the third expansion valve 33 , the third heat exchanger 16 may cool the refrigerant by exchanging heat with air introduced into the HVAC module 12 .

[0168] The refrigerant having passed through the third heat exchanger 16 may flow along the opened fourth connecting line 51. The refrigerant introduced into the fourth connecting line 51 may be expanded by the operation of the fourth expansion valve 53.

[0169] A portion of the refrigerant expanded from the fourth expansion valve 53 may flow along the refrigerant line 11 connected to the internal heat exchanger 17 a and flow into the internal heat exchanger 17 a .

[0170] The refrigerant having passed through the internal heat exchanger 17 a may pass through the cooler 20 along the refrigerant line 11 and the first connecting line 21 , and then pass through the internal heat exchanger 17 a and the accumulator 17 .

[0171] The remaining refrigerant in the refrigerant expanded by the fourth expansion valve 53 may pass through the second heat exchanger 14 and then flow along the fifth connecting line 61. The refrigerant introduced into the fifth connecting line 61 may pass through the internal heat exchanger 17a and the accumulator 17 together with the refrigerant having passed through the cooler 20.

[0172] Therefore, the second heat exchanger 14 can cool the supplied refrigerant by exchanging heat with the air, and at the same time, the cooler 20 can cool the supplied refrigerant by exchanging heat with the coolant. When such operations are repeatedly performed, the second heat exchanger 14 and the cooler 20 can recover waste heat of the electrical component 3 and heat of the surrounding air.

[0173] In other words, since the recovered waste heat of the electric components 3 and the ambient air heat are used to increase the temperature of the refrigerant, the heat pump system can reduce the power consumption of the compressor 10 and improve the heating efficiency.

[0174] The refrigerant having passed through the accumulator 17 may be supplied to the compressor 10 .

[0175] In addition, the refrigerant compressed to a high-temperature and high-pressure state by the compressor 10 may be introduced back into the first heat exchanger 13 along the refrigerant line 11 .

[0176] As described above, the refrigerants supplied to the first heat exchanger 13 and the third heat exchanger 16 , respectively, may increase the temperature of the air introduced into the HVAC module 12 .

[0177] Therefore, the air introduced from the outside may be converted into a high temperature state while sequentially passing through the third heat exchanger 16 and the first heat exchanger 13 , and flow into the interior of the vehicle, thereby achieving heating of the interior of the vehicle.

[0178] In this embodiment, reference Figure 3 Describe the operation of the vehicle interior in heating and dehumidification modes.

[0179] Figure 3 is an operation diagram of a heat pump system for a vehicle in heating and dehumidification modes of a vehicle interior according to an embodiment.

[0180] refer to Figure 3 , the various components in the air conditioning unit can heat and dehumidify the interior of the vehicle. Therefore, the refrigerant can circulate along the refrigerant pipeline 11.

[0181] A portion of the refrigerant line 11 connecting the first end of the first connection line 21 and the second end of the second connection line 31 may be opened by the operation of the first expansion valve 15 .

[0182] In addition, a portion of the refrigerant line 11 connecting the first end of the second connecting line 31 and the second heat exchanger 14 may be closed by the operation of the first valve 18 .

[0183] The refrigerant line 11 connecting the third heat exchanger 16 and the accumulator 17 may be opened by the operation of the second valve 19. In addition, the refrigerant line 11 connecting the second heat exchanger 14 and the internal heat exchanger 17a may be closed.

[0184] The first connection line 21 may be opened by the operation of the second expansion valve 23. The second connection line 31 may be opened by the operation of the third expansion valve 33.

[0185] The third expansion valve 33 may expand the refrigerant introduced from the first heat exchanger 13 through the second connection line 31. Thereafter, the third expansion valve 33 may supply the expanded refrigerant to the third heat exchanger 16 and the cooler 20, respectively.

[0186] Meanwhile, the first expansion valve 15 and the second expansion valve 23 may allow the introduced refrigerant to flow through the refrigerant line 11 and the first connection line 21 without expansion.

[0187] Therefore, the first heat exchanger 13 may cool the refrigerant by using the air introduced into the HVAC module 12 .

[0188] The coolant may be circulated through the first pipeline 2 by operation of a water pump (not shown). Therefore, the coolant having passed through the electric component 3 may be supplied to the cooler 20 along the first pipeline 2.

[0189] Therefore, the cooler 20 may evaporate the introduced refrigerant by exchanging heat with the coolant supplied through the first line 2. The cooler 20 may recover waste heat of the electric components 3 from the coolant heated by recovering the waste heat from the electric components 3.

[0190] In other words, since the recovered waste heat of the electric components 3 is used to increase the temperature of the refrigerant, the heat pump system can reduce the power consumption of the compressor 10 and improve the heating efficiency.

[0191] Although not shown in the figure, when the waste heat of the battery module 5 is also recovered, the coolant can be circulated through the second pipeline 4 by the operation of a water pump (not shown). Therefore, the coolant that has passed through the battery module 5 can be supplied to the cooler 20 along the second pipeline 4.

[0192] In the present embodiment, it is taken as an example that the first connecting line 21 is opened by the operation of the second expansion valve 23 to introduce the refrigerant into the cooler 20, but the present invention is not limited thereto.

[0193] In other words, when the waste heat of the electric component 3 or the battery module 5 does not need to be recovered by the cooler 20, the first connecting line 21 can be closed. The coolant cannot circulate through the first line 2 and the second line 4.

[0194] In the present embodiment, the third connection line 41 may be closed by operating the third valve 43. The fourth connection line 51 may be closed by operating the fourth expansion valve 53.

[0195] In addition, the fifth connecting line 61 may be closed by the operation of the fourth valve 63 .

[0196] Therefore, the refrigerant discharged from the compressor 10 or the refrigerant discharged from the first heat exchanger 13 does not flow into the second heat exchanger 14 .

[0197] In other words, the refrigerant discharged from the compressor 10 may flow into the first heat exchanger 13 along the refrigerant line 11. The refrigerant having passed through the first heat exchanger 13 may flow along the second connection line 31 connected to the refrigerant line 11.

[0198] The refrigerant flowing through the second connection line 31 may be expanded by the operation of the third expansion valve 33. Thereafter, a portion of the expanded refrigerant may flow into the third heat exchanger 16.

[0199] The remaining refrigerant in the expanded refrigerant may flow into the cooler 20 through the first connecting line 21 .

[0200] Then, the refrigerant having passed through the cooler 20 and the refrigerant having passed through the third heat exchanger 16 may pass through the internal heat exchanger 17 a and the accumulator 17 along the refrigerant line 11 .

[0201] In addition, the refrigerant having passed through the accumulator 17 may be supplied to the compressor 10 .

[0202] In addition, the refrigerant compressed to a high-temperature and high-pressure state by the compressor 10 may be introduced back into the first heat exchanger 13 along the refrigerant line 11 .

[0203] As described above, the refrigerant supplied to the first heat exchanger 13 may increase the temperature of the air introduced into the HVAC module 12 .

[0204] In other words, the air introduced into the HVAC module 12 may be dehumidified by the low-temperature refrigerant introduced into the third heat exchanger 16 while passing through the third heat exchanger 16. Thereafter, since the air is converted into a high-temperature state while passing through the first heat exchanger 13 and then introduced into the vehicle interior, the vehicle interior may be smoothly heated and dehumidified.

[0205] In addition, reference Figure 4 The operation of cooling the battery module 5 in the vehicle interior cooling mode is described.

[0206] Figure 4 is an operation diagram of a heat pump system for a vehicle according to an embodiment for cooling a battery module in a cooling mode of the interior of the vehicle.

[0207] refer to Figure 4 , the coolant may be circulated through the first pipeline 2 by the operation of a water pump (not shown). At the same time, the coolant may be circulated through the second pipeline 4 by the operation of a water pump (not shown).

[0208] In other words, the coolant having passed through the electric component 3 may be supplied to the cooler 20 along the first line 2 , and the coolant having passed through the battery module 5 may be supplied to the cooler 20 along the second line 4 .

[0209] The various components in the air conditioning unit may be used for cooling the interior of the vehicle. Therefore, the refrigerant may circulate along the refrigerant line 11 .

[0210] A portion of the refrigerant line 11 connecting the compressor 10 and the first heat exchanger 13 and a portion of the refrigerant line 11 connecting the first heat exchanger 13 and the second heat exchanger 14 may be closed by operation of the first valve 18 .

[0211] The first connecting line 21 may be opened by operation of the second expansion valve 23 for cooling of the electric component 3 and the battery module 5 .

[0212] Therefore, the coolant having passed through the battery module 5 may be supplied to the cooler 20 along the second line 4 .

[0213] The second expansion valve 23 may expand the refrigerant introduced into the first connecting line 21 and flow the expanded refrigerant to the cooler 20 , thereby cooling the battery module 5 by using the coolant exchanging heat with the refrigerant in the cooler 20 .

[0214] Therefore, the coolant having passed through the cooler 20 may be cooled by heat-exchanging with the expanded refrigerant supplied to the cooler 20 .

[0215] In other words, the coolant passing through the cooler 20 may be cooled by heat exchange with the expanded refrigerant supplied to the cooler 20. The coolant cooled in the cooler 20 may be supplied to the battery module 5 along the second line 4. Therefore, the battery module 5 may be effectively cooled by the coolant cooled at the cooler 20.

[0216] The second connection line 31 may be closed by operation of the third expansion valve 33. The third connection line 41 may be opened by operation of the third valve 43.

[0217] In addition, the fourth connection line 51 may be closed by the operation of the fourth expansion valve 53. In addition, the fifth connection line 61 may be closed by the operation of the fourth valve 63.

[0218] Therefore, the refrigerant discharged from the compressor 10 may flow along the third connecting line 41 without passing through the first heat exchanger 13 .

[0219] In other words, the refrigerant discharged from the compressor 10 may flow along the third connecting line 41 , and may flow into the second heat exchanger 14 along the refrigerant line 11 connected to the second heat exchanger 14 .

[0220] The second heat exchanger 14 may preliminarily cool the refrigerant using air introduced from the outside.

[0221] The refrigerant discharged from the second heat exchanger may flow into the internal heat exchanger 17a along the refrigerant line 11. The internal heat exchanger 17a may heat-exchange the refrigerant supplied from the second heat exchanger 14 with the refrigerants supplied from the third heat exchanger 16 and the cooler 20, respectively, to achieve additional cooling of the refrigerant supplied from the second heat exchanger 14.

[0222] A portion of the refrigerant discharged from the internal heat exchanger 17 a may flow into the cooler 20 along the first connecting line 21 .

[0223] The refrigerant introduced into the cooler 20 may exchange heat with the coolant supplied through the second line 4 , pass through the internal heat exchanger 17 a and the accumulator 17 through the refrigerant line 11 connected to the first connecting line 21 , and then flow into the compressor 10 .

[0224] In addition, the remaining refrigerant among the refrigerant discharged from the interior heat exchanger 17 a may flow into the first expansion valve 15 along the refrigerant line 11 to cool the interior of the vehicle.

[0225] The first expansion valve 15 may expand the refrigerant introduced through the refrigerant line 11 and allow the expanded refrigerant to flow to the third heat exchanger 16 .

[0226] The refrigerant having passed through the third heat exchanger 16 may pass through the internal heat exchanger 17 a , the accumulator 17 , and the compressor 10 in sequence along the refrigerant line 11 .

[0227] In other words, the refrigerant discharged from the cooler 20 and the refrigerant discharged from the third heat exchanger 16 may pass through the internal heat exchanger 17 a and the accumulator 17 along the refrigerant line 11 and then be supplied to the compressor 10 .

[0228] The air introduced into the HVAC module 12 may be cooled by the low-temperature refrigerant introduced into the third heat exchanger 16 while passing through the third heat exchanger 16 .

[0229] Since the cooled air directly enters the vehicle interior by passing through the first heat exchanger 13 to which the refrigerant is not supplied, the vehicle interior may be cooled.

[0230] The refrigerant, whose cooling amount is increased while sequentially passing through the second heat exchanger 14 and the internal heat exchanger 17a, is expanded and supplied to the third heat exchanger 16, and thus, the refrigerant may be evaporated to a lower temperature.

[0231] In other words, in the present embodiment, the second heat exchanger 14 may cool the refrigerant by exchanging heat with the air, and the internal heat exchanger 17a may additionally cool the refrigerant by exchanging heat with the low-temperature refrigerant.

[0232] Through this operation, the heat pump system can more efficiently cool the R744 refrigerant formed from carbon dioxide, thereby providing an advantage in the formation of subcooling of the refrigerant.

[0233] In addition, as the subcooled refrigerant evaporates at a lower temperature at the third heat exchanger 16, the temperature of the air passing through the third heat exchanger 16 is further reduced, thereby improving cooling performance and efficiency.

[0234] While the above-described process is repeatedly performed, the refrigerant may cool the vehicle interior in the vehicle interior cooling mode, and at the same time, the coolant is cooled by heat exchange while passing through the cooler 20 .

[0235] The low-temperature coolant cooled in the cooler 20 flows to the battery module 5 through the second line 4. Therefore, the battery module 5 can be effectively cooled by the supplied low-temperature coolant.

[0236] Therefore, as described above, when the heat pump system for a vehicle according to one embodiment is applied, since cooling or heating of the vehicle interior is performed by using a natural refrigerant, environmental regulations are complied with and the overall marketability of the vehicle can be improved.

[0237] In addition, according to the present invention, by applying R744 refrigerant, which is a natural refrigerant using carbon dioxide, the refrigeration and heating performance can be maximized by operating in a supercritical region, which refers to a state in which the pressure and temperature of the refrigerant are higher than a threshold pressure and temperature, for cooling and heating the interior of a vehicle.

[0238] Furthermore, according to the present invention, the temperature of the battery module 5 can be effectively adjusted using the single cooler 20 in which the coolant and the refrigerant perform heat exchange based on the vehicle mode, so that downsizing and simplification of the system can be achieved.

[0239] Furthermore, according to the embodiment, by effectively regulating the temperature of the battery module 5 , optimal performance of the battery module 5 may be achieved, and the overall driving distance of the vehicle may be increased due to the effective management of the battery module 5 .

[0240] Furthermore, according to the present invention, in the heating mode inside the vehicle, since the refrigerant expands and is split to be supplied to the second heat exchanger 14 and the cooler 20 respectively, the flow control of the refrigerant becomes easy, the ambient air heat and the waste heat of the electrical components can be smoothly recovered, and the optimal design of the cooler 20 can be achieved to cool the battery module.

[0241] Furthermore, according to the embodiments, manufacturing cost and weight can be reduced by simplifying the entire system, and space utilization can be improved.

[0242] While the invention has been described in conjunction with what are presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A heat pump system for a vehicle, the heat pump system comprising: an air conditioning unit including a compressor, a first heat exchanger, a second heat exchanger, a first expansion valve, and a third heat exchanger connected by a refrigerant line so that a refrigerant circulates through the refrigerant line; as well as a cooler connected to the refrigerant line through a first connecting line and configured to adjust the temperature of the coolant by exchanging heat between the refrigerant supplied from the air conditioning unit and the coolant, Wherein, the air conditioning unit further comprises: a first valve disposed in the refrigerant line between the first heat exchanger and the second heat exchanger; a second valve disposed in the refrigerant line between the third heat exchanger and the compressor; a second expansion valve, disposed in the first connecting line; a second connecting line having a first end connected to the refrigerant line between the first heat exchanger and the second heat exchanger and a second end connected to the refrigerant line between the second heat exchanger and the third heat exchanger; and The third expansion valve is arranged in the second connecting pipeline.

2. The heat pump system according to claim 1, wherein: The air conditioning unit further comprises: a third connecting line, a first end of which is connected to the refrigerant line between the compressor and the first heat exchanger, and a second end of which is connected to the refrigerant line between the first heat exchanger and the second heat exchanger; a third valve, disposed in the third connecting pipeline; a fourth connecting line, a first end of which is connected to the refrigerant line between the second heat exchanger and the third heat exchanger, and a second end of which is connected to the refrigerant line between the third heat exchanger and the compressor; a fourth expansion valve, disposed in the fourth connecting pipeline; a fifth connecting line having a first end connected to the refrigerant line between the third heat exchanger and the compressor and a second end connected to the refrigerant line between the first heat exchanger and the second heat exchanger; and A fourth valve is arranged in the fifth connecting pipeline.

3. The heat pump system according to claim 2, wherein: The air conditioning unit further comprises: an accumulator disposed in the refrigerant line between the third heat exchanger and the compressor; and An internal heat exchanger is provided inside the accumulator and is configured to heat-exchange the refrigerant supplied from the second heat exchanger and the refrigerant supplied from the third heat exchanger with each other and supply liquid refrigerant of the heat-exchanged refrigerants to the third heat exchanger.

4. The heat pump system according to claim 3, wherein: In vehicle interior heating mode: a portion of the refrigerant line connecting the first end of the first connecting line and the second end of the second connecting line is closed by the operation of the first expansion valve; a portion of the refrigerant line connecting the first end of the second connecting line and the second end of the fifth connecting line is closed by operation of the first valve; a portion of the refrigerant line connecting the second end of the fourth connecting line and the second end of the first connecting line, being closed by operation of the second valve; The first connecting line is opened by operation of the second expansion valve; The second connecting line is opened by operation of the third expansion valve; The third connecting line is closed by operation of the third valve; The fourth connecting line is opened by operation of the fourth expansion valve; and The fifth connecting line is opened by operation of the fourth valve.

5. The heat pump system according to claim 4, wherein: The fourth expansion valve is configured to expand the refrigerant so that the expanded refrigerant is supplied to the second heat exchanger, the internal heat exchanger, and the cooler, respectively.

6. The heat pump system according to claim 4, wherein: a portion of the refrigerant flowing from the third heat exchanger into the fourth connecting line flows into the second heat exchanger; and The remaining refrigerant of the refrigerant flowing from the third heat exchanger into the fourth connecting line flows into the internal heat exchanger.

7. The heat pump system according to claim 4, wherein: A portion of the refrigerant discharged from the fourth expansion valve passes through the internal heat exchanger along the refrigerant line and then flows into the cooler; and Refrigerant exhausted from the second heat exchanger and the cooler passes through the internal heat exchanger and the accumulator, and then is supplied to the compressor.

8. The heat pump system according to claim 4, wherein: the second expansion valve supplies the refrigerant introduced through the first connecting line to the cooler without expansion; and The third expansion valve supplies the refrigerant introduced through the second connecting line to the third heat exchanger without expansion.

9. The heat pump system according to claim 3, wherein: In heating and dehumidification mode for the vehicle interior: a portion of the refrigerant line connecting a first end of the first connecting line and a second end of the second connecting line, opened by operation of the first expansion valve; a portion of the refrigerant line connecting the first end of the second connecting line and the second heat exchanger is closed by operation of the first valve; the refrigerant line connecting the third heat exchanger and the accumulator is opened by the operation of the second valve; the refrigerant line connecting the second heat exchanger and the internal heat exchanger is closed; The first connecting line is opened by operation of the second expansion valve; The second connecting line is opened by operation of the third expansion valve; The third connecting line is closed by operation of the third valve; The fourth connecting line is closed by operation of the fourth expansion valve; and The fifth connecting line is closed by operation of the fourth valve.

10. The heat pump system according to claim 9, wherein: The third expansion valve is configured to expand the refrigerant introduced from the first heat exchanger through the second connecting line and to supply the expanded refrigerant to the third heat exchanger and the cooler, respectively.

11. The heat pump system according to claim 10, wherein: The first expansion valve and the second expansion valve are configured to flow introduced refrigerant without expansion.

12. The heat pump system according to claim 3, wherein: When the battery module needs to be cooled in the vehicle's internal cooling mode: a portion of the refrigerant line connecting the compressor and the first heat exchanger and a portion of the refrigerant line connecting the first heat exchanger and the second heat exchanger are closed by operation of the first valve; The first connecting line is opened by operation of the second expansion valve; The second connecting line is closed by operation of the third expansion valve; The third connecting line is opened by operation of the third valve; The fourth connecting line is closed by operation of the fourth expansion valve; and The fifth connecting line is closed by operation of the fourth valve.

13. The heat pump system according to claim 12, wherein: The first expansion valve is configured to expand the refrigerant introduced through the refrigerant line and to flow the expanded refrigerant to the third heat exchanger; and The second expansion valve is configured to expand the refrigerant introduced into the first connecting line and flow the expanded refrigerant to the cooler so as to cool the battery module by using the coolant exchanging heat with the refrigerant in the cooler.

14. The heat pump system according to claim 12, wherein: The refrigerant discharged from the compressor flows into the second heat exchanger along the third connecting line; A portion of the refrigerant discharged from the internal heat exchanger flows into the cooler along the first connecting line; The remaining refrigerant in the refrigerant discharged from the internal heat exchanger flows into the first expansion valve along the refrigerant line; and The refrigerant discharged from the cooler and the refrigerant discharged from the third heat exchanger pass through the internal heat exchanger and the accumulator along the refrigerant line and are then supplied to the compressor.

15. The heat pump system according to claim 1, wherein: The second heat exchanger and the third heat exchanger are configured to cool or evaporate refrigerant introduced into the inside.

16. The heat pump system according to claim 1, wherein: A first end of the first connecting line is connected to the refrigerant line between the second heat exchanger and the first expansion valve; and A second end of the first connecting line is connected to the refrigerant line between the third heat exchanger and the compressor.

17. The heat pump system according to claim 1, wherein: The refrigerant is R744 refrigerant formed of carbon dioxide.

18. The heat pump system according to claim 1, wherein: The cooler is connected to the electric components and the battery module through first and second lines, respectively, through which a coolant circulates.

19. The heat pump system according to claim 1, wherein: The first heat exchanger, the second heat exchanger, and the third heat exchanger are air-cooled gas coolers configured to perform heat exchange between the refrigerant introduced into the interior and the air; and The cooler is a water-cooled gas cooler configured to perform heat exchange between a refrigerant introduced into the inside and a coolant.

20. The heat pump system according to claim 2, wherein: The first expansion valve, the second expansion valve, the third expansion valve, and the fourth expansion valve are electronic expansion valves configured to selectively expand the refrigerant while controlling a flow of the refrigerant.

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