HEAT PUMP SYSTEM FOR A VEHICLE

Abstract

A heat pump system for a vehicle may be capable of cooling or heating a vehicle interior using natural refrigerant and efficiently adjusting the temperature of a battery module (5) by using a single heat exchange device (20) in which refrigerant and coolant exchange heat to respond to environmental regulations.

Description

Background(a) Area of ​​Revelation

[0001] The present disclosure and invention relate to a heat pump system for a vehicle. More specifically, the present disclosure and invention relate to a heat pump system for a vehicle capable of efficiently cooling or heating a vehicle interior using a natural refrigerant and adjusting the temperature of a battery module using a single heat exchange device in which refrigerant and coolant exchange heat. (b) Description of the technology purchased

[0002] Generally, an air conditioning system for a vehicle includes an air conditioning unit that circulates a refrigerant to heat or cool an interior of the vehicle.

[0003] The air conditioning unit, which is intended to keep the interior of the vehicle at an appropriate temperature regardless of a change in the outside temperature in order to maintain a comfortable interior environment, is adapted to heat or cool the interior of the vehicle by heat exchange by means of a condenser and an evaporator in a process in which a refrigerant discharged by the operation of a compressor circulates through the condenser, a receiver dryer, an expansion valve and the evaporator back to the compressor.

[0004] In other words, the air conditioning unit lowers a temperature and a humidity of the interior by condensing a high-temperature, high-pressure gas-phase refrigerant compressed by the compressor through the condenser, passing the refrigerant through the receiver drier and the expansion valve, and then evaporating the refrigerant in the evaporator in a cooling mode.

[0005] An environmentally friendly technology of a vehicle is a core technology of a future automobile industry, and advanced automobile manufacturers have focused their energy on developing an environmentally friendly vehicle to achieve environmental and fuel efficiency regulations.

[0006] Recently, due to the ever-increasing interest in energy efficiency and the problem of environmental pollution, there is a need to develop an environmentally friendly vehicle that can essentially replace an internal combustion engine. Environmentally friendly vehicles are divided into electric vehicles, which use a fuel cell or electricity (e.g., from a battery) as a power source, and hybrid vehicles, which use an internal combustion engine and a battery.

[0007] The electric vehicle is in focus as a future means of transport to solve environmental and energy resource problems.

[0008] A heat pump system, which is an air conditioning device for regulating the temperature in the vehicle interior, is used in such an electric vehicle.

[0009] However, the refrigerant commonly used in heat pump systems contains a large amount of substances regulated by environmental regulations, e.g., PFAS (per- and polyfluoroalkyl substances), and therefore there is a need to develop a system capable of regulating the temperature of the vehicle interior by using new refrigerants, without PFAS or flammability, or natural refrigerants.

[0010] The above information disclosed in this Background section is provided merely to enhance the understanding of the general background of the present disclosure / invention and may therefore contain information that does not constitute prior art already known to a person skilled in the art. Short explanation

[0011] The present disclosure or invention (hereinafter also referred to as disclosure) provides a heat pump system for a vehicle which is capable of cooling or heating a vehicle interior using a natural refrigerant and adjusting the temperature of a battery module by using a single (ie, e.g., in particular a single) heat exchange device in which a refrigerant and a coolant exchange heat with each other (also referred to as "being heat exchanged") in an efficient manner in order to comply with environmental regulations.

[0012] Furthermore, the present disclosure provides a heat pump system for a vehicle capable of maximizing cooling and heating performance by operating in a supercritical (also "supercritical") cycle / region, i.e., a state in which the pressure and temperature of the refrigerant are above a threshold pressure and temperature, by using the refrigerant R744, which is a natural refrigerant using carbon dioxide.

[0013] A heat pump system for a vehicle (e.g., a motor vehicle, for example, a passenger car) may include an air conditioning unit having 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 to circulate a refrigerant through the refrigerant line, and a heat exchange device (e.g., also called a "chiller device" or "cooling device," English "chiller"), which is connected to the refrigerant line by a first connecting line. The heat exchange device is configured to adjust the temperature of the coolant by heat exchanging the refrigerant supplied from the air conditioning unit with a coolant.The air conditioning unit may further comprise 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, a second connection 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 a third expansion valve provided in the second connection line.

[0014] The air conditioning unit may further comprise: a third connecting line having a first end connected to the refrigerant line between the compressor and the first heat exchanger, and a second end connected to the refrigerant line between the first heat exchanger and the second heat exchanger, a third valve provided in the third connecting line, a fourth connecting line having a first end connected to the refrigerant line between the second heat exchanger and the third heat exchanger, and a second end connected to the refrigerant line between the third heat exchanger and the compressor, a fourth expansion valve provided in the fourth connecting line, a fifth connecting line having a first end connected to the refrigerant line between the third heat exchanger and the compressor, and a second endwhich is connected to the refrigerant line between the first heat exchanger and the second heat exchanger, and a fourth valve which is provided in the fifth connecting line.

[0015] The air conditioning unit may further include an accumulator provided in the refrigerant line between the third heat exchanger and the compressor, and an indoor heat exchanger provided inside the accumulator and configured to allow the refrigerant supplied from the second heat exchanger and the refrigerant supplied from the third heat exchanger to exchange heat with each other and to supply a liquid refrigerant among the heat-exchanged refrigerant to the third heat exchanger.

[0016] In a heating mode of a vehicle interior, a section of the refrigerant line connecting a first end of the first connecting line to the second end of the second connecting line can be closed by an operation or actuation (hereinafter also referred to as operation) of the first expansion valve. A section of the refrigerant line connecting the first end of the second connecting line and the second end of the fifth connecting line can be closed by an operation of the first valve. A section of the refrigerant line connecting a second end of the fourth connecting line and a second end of the first connecting line can be closed by an operation of the second valve. The first connecting line can be opened by an operation of the second expansion valve.The second connecting line can be opened by operation of the third expansion valve. The third connecting line can be closed by operation of the third valve. The fourth connecting line can be opened by operation of the fourth expansion valve. The fifth connecting line can be opened by operation of the fourth valve.

[0017] The fourth expansion valve may be configured to expand the refrigerant so that the expanded refrigerant is supplied to the second heat exchanger, the indoor heat exchanger, and the heat exchange device, respectively.

[0018] A part of the refrigerant of the refrigerant flowing from the third heat exchanger into the fourth connection line may flow into the second heat exchanger, and a remaining refrigerant of the refrigerant flowing from the third heat exchanger into the fourth connection line may flow into the indoor heat exchanger.

[0019] A portion of the refrigerant discharged from the fourth expansion valve may flow through the indoor heat exchanger along the refrigerant line and then into the heat exchange device. The refrigerant discharged from the second heat exchanger and the heat exchange device may flow through the indoor heat exchanger and the accumulator and then be supplied to the compressor.

[0020] The second expansion valve may supply the refrigerant introduced via the first connecting line to the heat exchange device without expansion, and the third expansion valve may supply the refrigerant introduced via the second connecting line to the third heat exchanger without expansion.

[0021] In a heating and dehumidifying mode of a vehicle interior, a portion of the refrigerant line connecting a first end of the first connection line and the second end of the second connection line may be opened by operation of the first expansion valve. A portion of the refrigerant line connecting the first end of the second connection line and the second heat exchanger may be closed by operation of the first valve. The refrigerant line connecting the third heat exchanger and the accumulator may be opened by operation of the second valve. The refrigerant line connecting the second heat exchanger and the indoor heat exchanger is closed. The first connection line may be opened by operation of the second expansion valve. The second connection line may be opened by operation of the third expansion valve.The third connecting line can be closed by operation of the third valve. The fourth connecting line can be closed by operation of the fourth expansion valve. The fifth connecting line can be closed by operation of the fourth valve.

[0022] The third expansion valve may be configured to expand the refrigerant introduced through the second connecting line from the first heat exchanger and to supply the expanded refrigerant to the third heat exchanger and the heat exchange device, respectively.

[0023] The first expansion valve and the second expansion valve may be configured to pass the introduced refrigerant without expansion.

[0024] When cooling a battery module is required in a vehicle interior 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 may be closed by operation of the first valve. The first connecting line may be opened by operation of the second expansion valve. The second connecting line may be closed by operation of the third expansion valve. The third connecting line may be opened by operation of the third valve. The fourth connecting line may be closed by operation of the fourth expansion valve. The fifth connecting line may be closed by operation of the fourth valve.

[0025] The first expansion valve may be configured to expand the refrigerant introduced through the refrigerant line and direct the expanded refrigerant to the third heat exchanger. The second expansion valve may be configured to expand the refrigerant introduced into the first connection line and direct the expanded refrigerant to the heat exchange device to cool the battery module using the coolant that has exchanged heat with the refrigerant in the heat exchange device.

[0026] The refrigerant discharged from the compressor may flow into the second heat exchanger along the third connecting line. Part of the refrigerant discharged from the indoor heat exchanger may flow into the heat exchange device via the first connecting line. Remaining refrigerant discharged from the indoor heat exchanger may flow into the first expansion valve along the refrigerant line. The refrigerant discharged from the heat exchange device and the refrigerant discharged from the third heat exchanger may flow through the indoor heat exchanger and the accumulator along the refrigerant line and then be supplied to the compressor.

[0027] The second heat exchanger and the third heat exchanger may be configured to cool or evaporate a refrigerant introduced therein.

[0028] A first end of the first connecting line may be connected to the refrigerant line between the second heat exchanger and the first expansion valve, and a second end of the first connecting line may be connected to the refrigerant line between the third heat exchanger and the compressor.

[0029] The refrigerant can be refrigerant R744, which is formed from carbon dioxide.

[0030] The heat exchange device may be connected to an electrical component and a battery module respectively associated therewith through a first (e.g., coolant) line and a second (e.g., coolant) line circulating the coolant (e.g., through the first line to an electrical component and through the second line to the battery module).

[0031] The first heat exchanger, the second heat exchanger, and the third heat exchanger may be air-cooled gas coolers configured to exchange heat between the refrigerant introduced therein and air (e.g., heat exchange the refrigerant introduced therein with air). The heat exchange device may be a water-cooled gas cooler configured to exchange heat between the refrigerant introduced therein and the coolant (e.g., heat exchange the refrigerant introduced therein with coolant).

[0032] The first expansion valve, the second expansion valve, the third expansion valve and the fourth expansion valve may be electronic expansion valves configured to selectively expand the refrigerant while controlling the flow movement of the refrigerant.

[0033] The first valve, the second valve, the third valve and the fourth valve can be two-way valves.

[0034] As described above, by using a heat pump system for a vehicle according to an embodiment, it is possible to meet environmental regulations and improve the overall marketability of the vehicle because the cooling or heating of the vehicle interior is performed by using the natural refrigerant.

[0035] Furthermore, according to the disclosure, by using the refrigerant R744, 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 in which the pressure and temperature of the refrigerant are higher than a threshold value of pressure and temperature, to cool and heat the vehicle interior.

[0036] Furthermore, according to the disclosure, streamlining and simplification of the system can be achieved by efficiently adjusting the temperature of the battery module by using a single (ie, e.g., in particular, a single) heat exchange device for the coolant and the refrigerant according to the vehicle mode.

[0037] Furthermore, according to one embodiment, by efficiently adjusting the temperature of the battery module, optimal performance of the battery module can be enabled, and the overall range of the vehicle can be increased due to the efficient management of the battery module.

[0038] Furthermore, in the heating mode of the vehicle interior according to the disclosure, since the refrigerant is expanded and branched to be supplied to each heat exchanger, the flow of the refrigerant can be easily controlled, the heat of the ambient air and the waste heat of the electrical components can be recovered uniformly and / or easily, and at the same time, a heat exchange device for cooling the battery module can be optimally designed.

[0039] Furthermore, according to one embodiment, it is possible to reduce manufacturing costs and weight by simplifying an overall system and to improve space utilization. Short description of the drawings Fig. 1 is a block diagram of a heat pump system for a vehicle according to an embodiment. Fig. 2 is an operational diagram of a heat pump system for a vehicle according to an embodiment in a vehicle interior heating mode. Fig. 3 is an operation diagram of a heat pump system for a vehicle according to an embodiment in a heating and dehumidifying mode of the vehicle interior. Fig. 4 is an operational diagram of a heat pump system for a vehicle according to an embodiment for cooling a battery module in a vehicle interior cooling mode. Detailed description

[0040] An embodiment will be described in detail below with reference to the accompanying drawings.

[0041] The embodiments disclosed in this specification and the structures illustrated in the drawings are merely representative embodiments of the present disclosure and do not cover the entire scope of the present disclosure. Therefore, it is understood that numerous equivalents and modifications may exist at the time of this specification.

[0042] In order to clarify the present disclosure, parts not related to the description are omitted, and the same elements or equivalents are indicated by the same reference numerals throughout the description.

[0043] In addition, the size and thickness of the individual elements are shown arbitrarily in the drawings, but the present disclosure is not necessarily limited thereto, and in the drawings, the thicknesses of layers, films, plates, regions and the like are exaggerated for clarity.

[0044] Unless expressly stated otherwise, the word “comprise” and variations such as “comprises” or “comprising” are to be understood as including the specified elements but not excluding other elements.

[0045] In addition, each of the terms described in the description, such as "...unit", "...means", "...section", "...part" and "...element", means a unit of a parent element that performs at least one function or operation.

[0046] Fig. 1 is a block diagram of a heat pump system of a vehicle according to an embodiment.

[0047] A heat pump system for a vehicle according to an embodiment can cool or heat a vehicle interior using a natural refrigerant and adjust a temperature of a battery module 5 in an efficient manner by using a single (ie, e.g., in particular, a single) heat exchange device 20 that exchanges heat between the refrigerant and a coolant, so as to respond to environmental regulations.

[0048] The refrigerant may be a carbon dioxide-formed R744 refrigerant (also referred to as “refrigerant R744”), which has an ozone depletion potential (ODP) of 0 and a global warming potential (GWP) of 1.

[0049] In other words, a heat pump system for a vehicle according to one embodiment can maximize cooling and heating performance by using the refrigerant R744, which is a natural refrigerant using carbon dioxide, by operating in a supercritical (also "supercritical") cycle / region, that is, in a state where the pressure and temperature of the refrigerant are higher than a threshold pressure and temperature.

[0050] For this purpose, the heat pump system according to one embodiment may comprise a (e.g. air) air conditioning unit and the heat exchange device (e.g. also called “chiller device” or “cooler device”, English “chiller”) 20.

[0051] Referring to Fig. 1, the air conditioning unit may comprise a compressor 10, a first heat exchanger 13, a second heat exchanger 14, a third heat exchanger 16, an accumulator 17 and an indoor heat exchanger (e.g. also “internal heat exchanger”) 17a, which are connected to each other by a refrigerant line 11 in order to circulate the refrigerant through the refrigerant line 11.

[0052] First, the compressor 10 can compress the introduced refrigerant and supply the compressed refrigerant into the refrigerant line 11 so that the refrigerant can circulate along the refrigerant line 11.

[0053] The first heat exchanger 13 can carry out a heat exchange of the refrigerant selectively (ie, for example, optionally) supplied by the compressor 10 with the air.

[0054] The second heat exchanger 14 may be connected to the first heat exchanger 13 through the refrigerant line 11. Accordingly, the refrigerant supplied to the refrigerant line 11 may flow through the second heat exchanger 14.

[0055] The second heat exchanger 14 may be arranged on a front side of the vehicle and may cool or evaporate the refrigerant by exchanging heat with the air supplied from outside while the vehicle is running.

[0056] Because R744 refrigerant is a supercritical refrigerant and differs from other refrigerants in that it does not undergo phase change, it is referred to as a gas cooling refrigerant rather than a condensing refrigerant.

[0057] 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.

[0058] In addition, the third heat exchanger 16 may be provided in the refrigerant line 11 between the first expansion valve 15 and the compressor 10.

[0059] The first heat exchanger 13 and the third heat exchanger 16 may be provided in an interior of a heating, ventilation and air conditioning (HVAC) module 12.

[0060] Accordingly, the third heat exchanger 16 can cool or evaporate the refrigerant by exchanging heat with the air supplied to the HVAC module 12.

[0061] In other words, the first heat exchanger 13, the second heat exchanger 14 and the third heat exchanger 16 may be an air-cooled gas cooler which is configured to cool the refrigerant introduced therein (ie, for example, into their interior or internally) by heat exchange with air.

[0062] The second heat exchanger 14 and the third heat exchanger 16 can evaporate the refrigerant when the expanded refrigerant is introduced and cool the refrigerant when the unexpanded refrigerant is introduced.

[0063] In the present embodiment, the accumulator 17 may be provided in the refrigerant line 11 between the third heat exchanger 16 and the compressor 10.

[0064] The accumulator 17 supplies only gaseous refrigerant to the compressor 10, thereby improving the efficiency and service life of the compressor 10.

[0065] Furthermore, the indoor heat exchanger 17a may be provided inside the accumulator 17. The indoor heat exchanger 17a may allow the refrigerant supplied from the second heat exchanger 14 and the refrigerant supplied from the third heat exchanger 16 to exchange heat with each other, and supply a liquid refrigerant in the heat-exchanged refrigerant to the third heat exchanger 16.

[0066] In other words, the indoor heat exchanger 17a can allow the refrigerant cooled by the second heat exchanger 14 to exchange heat with the low-temperature refrigerant (ie, 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.

[0067] In the present embodiment, the heat exchange device 20 may be connected to an electrical component 3 via a first line 2 through which the coolant circulates.

[0068] The electrical component 3 may include an electrical power control unit (EPCU), a power conversion device such as an electric motor, an inverter, an on-board charging device (OBC) or the like, and an autonomous driving control device or the like.

[0069] The electrical component 3 configured in this way can be water-cooled by being connected to the first line 2.

[0070] The heat exchange device 20 can adjust a temperature of the electrical component 3 using the coolant heat-exchanged with the refrigerant and can recover a waste heat of the electrical component 3.

[0071] Furthermore, the heat exchange device 20 may be connected to the battery module 5 via a second conduit 4 through which the coolant circulates. Accordingly, the coolant may selectively circulate through an interior of the heat exchange device 20.

[0072] The heat exchange device 20 can exchange heat from the refrigerant supplied from the air conditioning unit with the coolant, thereby adjusting the temperature of the coolant. In other words, the heat exchange device 20 can be a water-cooled gas cooler configured to perform heat exchange between the refrigerant introduced therein and the coolant.

[0073] The heat exchange device 20 can be connected to the refrigerant line 11 via a first connecting line 21.

[0074] 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. Furthermore, 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.

[0075] In other words, the heat exchange device 20 can heat exchange the coolant selectively introduced via the first line 2 or the second line 4 with the refrigerant selectively supplied from the air conditioning unit to adjust the temperature of the coolant.

[0076] Accordingly, the coolant that has exchanged heat in the heat exchange device 20 can circulate through the first conduit 2 through the electrical component 3. Furthermore, the coolant that has exchanged heat in the heat exchange device 20 can circulate through the second conduit 4 through the battery module 5.

[0077] A (e.g. respective, ie e.g. one each) water pump (not shown) can be provided in the first line 2 and the second line 4.

[0078] In other words, the coolant can be circulated in the first pipe 2 and the second pipe 4 by operating each water pump (not shown).

[0079] Accordingly, the coolant heat-exchanged with the refrigerant in the heat exchange device 20 can be selectively supplied to the electrical component 3 and the battery module 5, thereby adjusting the temperature of the electrical component 3 and the battery module 5.

[0080] In the present embodiment, the air conditioning unit may further include a first valve 18, a second valve 19, a second expansion valve 23, a second connection line 31, a third expansion valve 33, a third connection line 41, a third valve 43, a fourth connection line 51, a fourth expansion valve 53, a fifth connection line 61, and a fourth valve 63.

[0081] The first valve 18 may be provided in the refrigerant line 11 between the first heat exchanger 13 and the second heat exchanger 14.

[0082] The first valve 18 can 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.

[0083] 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. Specifically, the second valve 19 may be provided in the refrigerant line 11 between the third heat exchanger 16 and the accumulator 17.

[0084] The second valve 19 can 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 can close the refrigerant line 11 so that the refrigerant discharged from the third heat exchanger 16 cannot flow into the accumulator 17.

[0085] In other words, in the case of a heating mode of the vehicle interior, the second valve 19 can close the refrigerant line 11 so that the refrigerant discharged from the third heat exchanger 16 cannot flow into the accumulator 17.

[0086] On the other hand, in a vehicle interior cooling mode or a vehicle interior heating and dehumidifying mode, the second valve 19 can open the refrigerant line 11 so that the refrigerant discharged from the third heat exchanger 16 can flow into the accumulator 17.

[0087] The second expansion valve 23 may be provided in the first connecting line 21.

[0088] Depending on the cooling mode or the heating mode of the vehicle interior, the second expansion valve 23 can selectively expand the refrigerant introduced into the first connection line 21 and supply the selectively expanded refrigerant to the heat exchange device 20.

[0089] In addition, the second expansion valve 23 may supply the refrigerant introduced into the first connection line 21 to the heat exchange device 20 without expansion or close the first connection line 21 so that the refrigerant cannot be supplied to the heat exchange device 20.

[0090] Specifically, when cooling the battery module 5 using the coolant that has exchanged heat with the refrigerant in the heat exchange device 20, the second expansion valve 23 can open the first connection line 21. At the same time, the second expansion valve 23 can expand the refrigerant introduced into the first connection line 21 and supply the expanded refrigerant to the heat exchange device 20.

[0091] In other words, the second expansion valve 23 can expand the refrigerant discharged from the second heat exchanger 14 to lower the temperature and supply the expanded refrigerant to the heat exchange device 20, whereby the temperature of the coolant flowing through the interior of the heat exchange device 20 can be further lowered.

[0092] Accordingly, the battery module 5 can be cooled more efficiently by circulating the coolant, the temperature of which is lowered as it flows through the heat exchange device 20.

[0093] In the present embodiment, a first end of the second connection 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 connection line 31 may be connected to the refrigerant line 11 between the second heat exchanger 14 and the third heat exchanger 16.

[0094] The third expansion valve 33 may be provided in the second connecting line 31. The third expansion valve 33 may selectively open and close the second connecting line 31 and may selectively expand the refrigerant introduced into the second connecting line 31.

[0095] In the case of the vehicle interior cooling mode, the third expansion valve 33 can close the second connecting line 31. In the case of the vehicle interior heating mode, however, the third expansion valve 33 can open the second connecting line 31.

[0096] In addition, in the case of the heating and dehumidifying mode of the vehicle interior, the third expansion valve 33 can open the second connecting pipe 31 and expand the refrigerant introduced into the second connecting pipe 31.

[0097] In other words, the third expansion valve 33 can selectively expand the refrigerant while controlling the flow movement of the refrigerant.

[0098] In the present 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.

[0099] 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.

[0100] In other words, in the case of the vehicle interior cooling mode, the third valve 43 can open the third connecting line 41. In the case of the vehicle interior heating mode and in the case of the vehicle interior heating and dehumidification mode, however, the third valve 43 can close the third connecting line 41.

[0101] A first end of the fourth connecting 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 connecting line 51 may be connected to the refrigerant line 11 between the third heat exchanger 16 and the accumulator 17.

[0102] The fourth expansion valve 53 may be provided in the fourth connecting line 51.

[0103] The fourth expansion valve 53 can control the flow of the refrigerant by selectively opening and closing the fourth connection line 51 and can selectively expand the refrigerant introduced into the fourth connection line 51.

[0104] In other words, in the vehicle interior heating mode, the fourth expansion valve 53 may open the fourth connecting pipe 51 and expand the refrigerant introduced into the fourth connecting pipe 51 and supply the expanded refrigerant to the second heat exchanger 14 and the indoor heat exchanger 17a, respectively.

[0105] Accordingly, in the heating mode of the vehicle interior, the second heat exchanger 14 can evaporate the refrigerant by heat exchange with the air supplied from the outside.

[0106] The refrigerant that has flowed through the internal heat exchanger 17a can be supplied to the heat exchange device 20. The heat exchange device 20 can evaporate the refrigerant by heat exchange with the coolant supplied through the first line 2.

[0107] In contrast, in the vehicle interior cooling mode or the vehicle interior heating and dehumidifying mode, the fourth expansion valve 53 may close the fourth connecting pipe 51.

[0108] In the present 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.

[0109] Furthermore, the fourth valve 63 may be provided in the fifth connecting line 61. The fourth valve 63 may control the refrigerant flow by selectively opening and closing the fifth connecting line 61.

[0110] In the case of the vehicle interior cooling mode or the vehicle interior heating and dehumidification mode, the fourth valve 63 can close the fifth connecting line 61. In the vehicle interior heating mode, however, the fourth valve 63 can open the fifth connecting line 61.

[0111] The first valve 18, the second valve 19, the third valve 43 and the fourth valve 63 may each be a two-way valve which controls the opening and closing of the refrigerant line 11, the third connecting line 41 and the fifth connecting line 61.

[0112] 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 movement of the refrigerant.

[0113] The operation and effect of a heat pump system for a vehicle according to an embodiment configured as described above will be described below with reference to Fig. 2 to 4 are described in detail.

[0114] First, the operation in the heating mode of the vehicle interior is described with reference to Fig. 2 described.

[0115] Fig. 2 is an operation diagram of a heat pump system for a vehicle according to an embodiment in the vehicle interior heating mode.

[0116] With reference to Fig. 2, the coolant can circulate through the first line 2 by operating a water pump (not shown).

[0117] Accordingly, after passing through the electrical component 3, the coolant can be supplied to the heat exchange device 20 along the first line 2.

[0118] The respective components in the air conditioning unit can operate to heat the vehicle interior. Accordingly, the refrigerant can circulate along the refrigerant line 11.

[0119] A section of the refrigerant line 11, which connects the first end of the first connecting line 21 to the second end of the second connecting line 31, can be closed by an operation or actuation (hereinafter also referred to as: operation) of the first expansion valve 15.

[0120] 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 operation of the first valve 18.

[0121] 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 operation of the second valve 19.

[0122] At the same time, the first connecting line 21 can be opened by operating the second expansion valve 23. The second expansion valve 23 can supply the refrigerant introduced via the first connecting line 21 to the heat exchange device 20 without expansion.

[0123] The second connecting line 31 can be opened by operating the third expansion valve 33. The third expansion valve 33 can supply the refrigerant introduced via the second connecting line 31 to the third heat exchanger 16 without expansion.

[0124] Accordingly, the first heat exchanger 13 and the third heat exchanger 16 can cool the refrigerant using the air introduced into the HVAC module 12.

[0125] In the present embodiment, the third connection line 41 may be closed by operation of the third valve 43. The fourth connection line 51 may be opened by operation of the fourth expansion valve 53.

[0126] Accordingly, a part of the refrigerant flowing from the third heat exchanger 16 into the fourth connecting line 51 can flow into the second heat exchanger 14.

[0127] At the same time, a remaining refrigerant from the refrigerant flowing from the third heat exchanger 16 into the fourth connecting line 51 can flow along the refrigerant line 11 into the indoor heat exchanger 17a.

[0128] The fourth expansion valve 53 can expand the refrigerant so that the expanded refrigerant is supplied to the second heat exchanger 14, the indoor heat exchanger 17a and the heat exchange device 20, respectively.

[0129] Accordingly, the second heat exchanger 14 can evaporate the expanded refrigerant by heat exchange with the air introduced from the outside. The second heat exchanger 14 can recover (i.e., absorb) the heat from the ambient air, whereby the expanded refrigerant is evaporated by heat exchange with the air.

[0130] Furthermore, the heat exchange device 20 can evaporate the expanded refrigerant by heat exchange with the coolant supplied through the first line 2. The heat exchange device 20 can recover the waste heat of the electrical component 3 from the coolant that has been heated by absorbing the waste heat of the electrical component 3.

[0131] In addition, the fifth connecting line 61 can be opened by operating the fourth valve 63.

[0132] Accordingly, the refrigerant discharged from the second heat exchanger 14 can flow along the fifth connection line 61 and the refrigerant discharged from the heat exchange device 20 can flow along the first connection line 21.

[0133] The refrigerants flowing through the first connecting pipe 21 and the fifth connecting pipe 61 can flow through the indoor heat exchanger 17a and the accumulator 17 along the refrigerant pipe 11 and then be supplied to the compressor 10.

[0134] In other words, part of the refrigerant from the refrigerant expanded by the fourth expansion valve 53 may flow along the refrigerant line 11 through the indoor heat exchanger 17a and then flow into the heat exchange device 20.

[0135] In addition, the refrigerant discharged from the second heat exchanger 14 and the heat exchange device 20 may flow through the indoor heat exchanger 17a and the accumulator 17 and then be supplied to the compressor 10.

[0136] In such a state, the refrigerant supplied from the compressor 10 can flow into the first heat exchanger 13 along the refrigerant line 11. The refrigerant that has flowed through the first heat exchanger 13 can flow along the second connecting line 31, which is connected to the refrigerant line 11.

[0137] The refrigerant flowing along the second connecting line 31 can flow into the third heat exchanger 16 along the refrigerant line 11 connected to the third heat exchanger 16.

[0138] The first heat exchanger 13 and the third heat exchanger 16 can cool the refrigerant by heat exchange between the refrigerant and the air introduced into the HVAC module 12. The refrigerant primarily cooled in the first heat exchanger 13 can be additionally cooled (e.g., secondarily) in the third heat exchanger 16.

[0139] In other words, when the refrigerant that has passed through the first heat exchanger 13 is supplied to the third heat exchanger 16 without being expanded by the operation of the third expansion valve 33, the third heat exchanger 16 can cool the refrigerant by heat exchanging the refrigerant with the air introduced into the HVAC module 12.

[0140] The refrigerant that has flowed through the third heat exchanger 16 can flow along the opened fourth connecting line 51. The refrigerant introduced into the fourth connecting line 51 can be expanded by the operation of the fourth expansion valve 53.

[0141] A part of the refrigerant from the refrigerant expanded by the fourth expansion valve 53 may flow along the refrigerant pipe 11 connected to the indoor heat exchanger 17a and flow into the indoor heat exchanger 17a.

[0142] The refrigerant that has flowed through the indoor heat exchanger 17a may flow along the refrigerant line 11 and the first connecting line 21 through the heat exchange device 20 and then flow through the indoor heat exchanger 17a and the accumulator 17.

[0143] Remaining refrigerant from the refrigerant expanded by the fourth expansion valve 53 may flow through the second heat exchanger 14 and then flow along the fifth connection line 61. The refrigerant introduced into the fifth connection line 61 may flow through the indoor heat exchanger 17a and the accumulator 17 together with the refrigerant that has passed through the heat exchange device 20.

[0144] Accordingly, the second heat exchanger 14 can cool the supplied refrigerant by heat exchange with the air, and at the same time, the heat exchange device 20 can cool the supplied refrigerant by heat exchange with the coolant. By repeatedly performing such an operation, the second heat exchanger 14 and the heat exchange device 20 can recover the waste heat of the electrical component 3 and extract heat from the ambient air.

[0145] In other words, since the recovered waste heat of the electrical component 3 and the absorbed 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.

[0146] The refrigerant that has flowed through the accumulator 17 can be fed to the compressor 10.

[0147] In addition, the refrigerant compressed to a high temperature and high pressure state by the compressor 10 can be returned to the first heat exchanger 13 along the refrigerant line 11.

[0148] As described above, the refrigerant supplied to the first heat exchanger 13 and the third heat exchanger 16, respectively, can increase the temperature of the air introduced into the HVAC module 12.

[0149] Accordingly, the air introduced from the outside can be converted into a high-temperature state while passing through the third heat exchanger 16 and the first heat exchanger 13 in sequence, and flow into the vehicle interior, thereby achieving heating of the vehicle interior.

[0150] In the present embodiment, the operation in the heating and dehumidifying mode of the vehicle interior will be described with reference to Fig. 3 described.

[0151] Fig. 3 is an operation diagram of a heat pump system for a vehicle according to an embodiment in the heating and dehumidification mode of the vehicle interior.

[0152] With reference to Fig. 3, the respective components in the air conditioning unit can operate to heat and dehumidify the vehicle interior. Consequently, the refrigerant can circulate along the refrigerant line 11.

[0153] A portion of the refrigerant line 11 connecting the first end of the first connecting line 21 and the second end of the second connecting line 31 may be opened by the operation of the first expansion valve 15.

[0154] 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.

[0155] 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. Furthermore, the refrigerant line 11 connecting the second heat exchanger 14 and the indoor heat exchanger 17a may be closed.

[0156] The first connecting line 21 can be opened by the operation of the second expansion valve 23. The second connecting line 31 can be opened by the operation of the third expansion valve 33.

[0157] The third expansion valve 33 can expand the refrigerant introduced from the first heat exchanger 13 through the second connecting line 31. Thereafter, the third expansion valve 33 can supply the expanded refrigerant to the third heat exchanger 16 and the heat exchange device 20, respectively.

[0158] At the same time, the first expansion valve 15 and the second expansion valve 23 can pass the introduced refrigerant through the refrigerant line 11 and the first connecting line 21 without expansion.

[0159] Accordingly, the first heat exchanger 13 can cool the refrigerant using the air introduced into the HVAC module 12.

[0160] The coolant may circulate through the first conduit 2 by operating a water pump (not shown). Accordingly, after flowing through the electrical component 3, the coolant may be supplied to the heat exchange device 20 along the first conduit 2.

[0161] Consequently, the heat exchange device 20 can evaporate the introduced refrigerant by heat exchange with the coolant supplied through the first line 2. The heat exchange device 20 can recover the waste heat of the electrical component 3 from the coolant that has been heated by absorbing the waste heat of the electrical component 3.

[0162] In other words, since the recovered waste heat of the electrical component 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.

[0163] Although not shown in the drawings, if the waste heat of the battery module 5 is also to be collectively recovered, the coolant may be circulated through the second conduit 4 by operating a water pump (not shown). Accordingly, the coolant that has flowed through the battery module 5 may be supplied to the heat exchange device 20 along the second conduit 4.

[0164] The present embodiment uses an example that the first connection line 21 is opened by the operation of the second expansion valve 23 so that the refrigerant can be introduced into the heat exchange device 20, but is not limited thereto.

[0165] In other words, if the waste heat of the electrical component 3 or the battery module 5 does not need to be recovered by the heat exchange device 20, the first connecting line 21 can be closed. The coolant can then not circulate through the first line 2 and the second line 4.

[0166] 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 closed by the operation of the fourth expansion valve 53.

[0167] In addition, the fifth connecting line 61 can be closed by the operation of the fourth valve 63.

[0168] Accordingly, the refrigerant discharged from the compressor 10 or from the first heat exchanger 13 cannot flow into the second heat exchanger 14.

[0169] In other words, the refrigerant discharged from the compressor 10 can flow into the first heat exchanger 13 along the refrigerant line 11. The refrigerant that has flowed through the first heat exchanger 13 can flow along the second connecting line 31 connected to the refrigerant line 11.

[0170] The refrigerant flowing through the second connecting line 31 can be expanded by the operation of the third expansion valve 33. Afterward, a portion of the expanded refrigerant can flow into the third heat exchanger 16.

[0171] A remaining refrigerant from the expanded refrigerant can flow into the heat exchange device 20 through the first connecting line 21.

[0172] Subsequently, the refrigerant that has flowed through the heat exchange device 20 and the refrigerant that has flowed through the third heat exchanger 16 can flow along the refrigerant line 11 through the indoor heat exchanger 17a and the accumulator 17.

[0173] In addition, the refrigerant that has flowed through the accumulator 17 can be fed to the compressor 10.

[0174] In addition, the refrigerant compressed to a high temperature and high pressure state by the compressor 10 can be returned to the first heat exchanger 13 along the refrigerant line 11.

[0175] As described above, the refrigerant supplied to the first heat exchanger 13 can increase the temperature of the air introduced into the HVAC module 12.

[0176] In other words, the air introduced into the HVAC module 12 can be dehumidified by the low-temperature refrigerant introduced into the third heat exchanger 16 while passing through the third heat exchanger 16. Since the air is subsequently converted to a high-temperature state while passing through the first heat exchanger 13 and then introduced into the vehicle interior, the vehicle interior can be uniformly heated and dehumidified.

[0177] In addition, the operation for cooling the battery module 5 in the vehicle interior cooling mode will be explained with reference to Fig. 4 described.

[0178] Fig. 4 is an operational diagram of a heat pump system for a vehicle according to an embodiment for cooling a battery module in a vehicle interior cooling mode.

[0179] With reference to Fig.4, the coolant can circulate through the first line 2 by operating a water pump (not shown). At the same time, the coolant can circulate through the second line 4 by operating a water pump (not shown).

[0180] In other words, the coolant that has flowed through the electrical component 3 can be supplied to the heat exchange device 20 via the first line 2 and the coolant that has flowed through the battery module 5 can be supplied to the heat exchange device 20 via the second line 4.

[0181] The respective components in the air conditioning unit can operate to cool the vehicle interior. Accordingly, the refrigerant can circulate along the refrigerant line 11.

[0182] 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 the operation of the first valve 18.

[0183] The first connecting line 21 can be opened by the operation of the second expansion valve 23 for cooling the electrical component 3 and the battery module 5.

[0184] Accordingly, the coolant which has flowed through the battery module 5 can be supplied to the heat exchange device 20 via the second line 4.

[0185] The second expansion valve 23 can expand the refrigerant introduced into the first connection line 21 and supply the expanded refrigerant to the heat exchange device 20 to cool the battery module 5 using the coolant that has exchanged heat with the refrigerant in the heat exchange device 20.

[0186] Accordingly, the coolant flowing through the heat exchange device 20 can be cooled by heat exchange with the expanded refrigerant supplied to the heat exchange device 20.

[0187] In other words, the coolant flowing through the heat exchange device 20 can be cooled by heat exchange with the expanded refrigerant supplied to the heat exchange device 20. The coolant cooled in the heat exchange device 20 can be supplied to the battery module 5 via the second conduit 4. Accordingly, the battery module 5 can be efficiently cooled by the coolant cooled in the heat exchange device 20.

[0188] The second connecting line 31 can be closed by the operation of the third expansion valve 33. The third connecting line 41 can be opened by the operation of the third valve 43.

[0189] In addition, the fourth connecting line 51 may be closed by the operation of the fourth expansion valve 53. In addition, the fifth connecting line 61 may be closed by the operation of the fourth valve 63.

[0190] Consequently, the refrigerant discharged from the compressor 10 can flow along the third connecting line 41 without flowing through the first heat exchanger 13.

[0191] In other words, the refrigerant discharged from the compressor 10 can flow along the third connecting line 41 and flow into the second heat exchanger 14 along the refrigerant line 11 connected to the second heat exchanger 14.

[0192] The second heat exchanger 14 can primarily cool the refrigerant by means of the air introduced from outside.

[0193] The refrigerant discharged from the second heat exchanger 14 can flow into the indoor heat exchanger 17a along the refrigerant line 11. The indoor heat exchanger 17a can subject the refrigerant supplied from the second heat exchanger 14 to heat exchange with the refrigerant supplied from the third heat exchanger 16 and the heat exchange device 20, respectively, in order to achieve additional (e.g., secondary) cooling of the refrigerant supplied from the second heat exchanger 14.

[0194] A part of the refrigerant discharged from the indoor heat exchanger 17a may flow into the heat exchange device 20 along the first connecting pipe 21.

[0195] The refrigerant introduced into the heat exchange device 20 can exchange heat with the coolant supplied via the second supply line 4, flow through the indoor heat exchanger 17a and the accumulator 17 via the refrigerant line 11 connected to the first connection line 21, and then flow into the compressor 10.

[0196] In addition, a remaining refrigerant from the refrigerant discharged from the indoor heat exchanger 17a can flow into the first expansion valve 15 along the refrigerant line 11 to cool the vehicle interior.

[0197] The first expansion valve 15 can expand the refrigerant introduced through the refrigerant line 11 and direct the expanded refrigerant to the third heat exchanger 16.

[0198] The refrigerant which has flowed through the third heat exchanger 16 can flow successively through the indoor heat exchanger 17a, the accumulator 17 and the compressor 10 along the refrigerant line 11.

[0199] In other words, the refrigerant discharged from the heat exchange device 20 and the refrigerant discharged from the third heat exchanger 16 can flow along the refrigerant line 11 through the indoor heat exchanger 17a and the accumulator 17 and then be supplied to the compressor 10.

[0200] The air introduced into the HVAC module 12 can be cooled by the low-temperature refrigerant introduced into the third heat exchanger 16 while flowing through the third heat exchanger 16.

[0201] Since the cooled air is introduced directly into the vehicle interior by flowing through the first heat exchanger 13, which is not supplied with the refrigerant, it can cool the vehicle interior.

[0202] The refrigerant with increased cooling quantity when flowing successively through the second heat exchanger 14 and the indoor heat exchanger 17a is expanded and supplied to the third heat exchanger 16 so that the refrigerant can be evaporated to an even lower temperature.

[0203] In other words, in the present embodiment, the second heat exchanger 14 can cool the refrigerant by heat exchange with the air, and the indoor heat exchanger 17a can additionally cool the refrigerant by heat exchange with the low-temperature refrigerant.

[0204] Through such a process, the heat pump system can cool the R744 refrigerant, which is formed from carbon dioxide, more efficiently, which provides an advantage for the formation of subcooling of the refrigerant.

[0205] In addition, since the refrigerant formed with subcooling is evaporated at a lower temperature at the third heat exchanger 16, the temperature of the air flowing through the third heat exchanger 16 can be further lowered, thereby improving the cooling performance and efficiency.

[0206] By repeatedly performing the above-described operations, the refrigerant can cool the vehicle interior in the vehicle interior cooling mode and, at the same time, cool the coolant by heat exchange when flowing through the heat exchange device 20.

[0207] The low-temperature coolant cooled in the heat exchange device 20 flows through the second line 4 to the battery module 5. Accordingly, the battery module 5 can be efficiently cooled by the supplied low-temperature coolant.

[0208] Therefore, as described above, in the application of a heat pump system for a vehicle according to an embodiment, since cooling or heating of a vehicle interior is performed using a natural refrigerant, it is possible to respond to environmental regulations, and the overall marketability of the vehicle can be improved.

[0209] Furthermore, according to the disclosure, by using the refrigerant R744, 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 in which the pressure and temperature of the refrigerant are higher than a threshold value of pressure and temperature, to cool and heat the vehicle interior.

[0210] Furthermore, according to the disclosure, the temperature of the battery module 5 is efficiently adjusted by using a single (ie, e.g., in particular, a single) heat exchange device 20 for the coolant and the refrigerant depending on the vehicle mode, whereby streamlining and simplification of the system can be achieved.

[0211] Furthermore, according to one embodiment, by efficiently adjusting the temperature of the battery module 5, the optimal performance of the battery module 5 can be enabled, and the overall range of the vehicle can be increased due to the efficient management of the battery module 5.

[0212] Furthermore, in the heating mode of the vehicle interior according to the present disclosure, since the refrigerant is expanded and branched to be supplied to the second heat exchanger 14 and the heat exchanging device 20, respectively, the flow control of the refrigerant can be simplified, the ambient air heat and waste heat of electrical components can be recovered uniformly and / or easily, and at the same time, an optimal design of the heat exchanging device 20 for cooling the battery module can be achieved.

[0213] Furthermore, according to one embodiment, it is possible to reduce manufacturing costs and weight by simplifying the overall system and to improve space utilization.

[0214] While this disclosure has been described in connection with the embodiments presently contemplated as practical, it is to be understood that the disclosure is not limited to the present embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. List of reference symbols 2, 4 First and second line 3 Electrical components 5 Battery module 10 compressors 11 Refrigerant line 12 HVAC module 13, 14, 16 First, second and third heat exchangers 15 First expansion valve 17 Accumulator 17a Indoor heat exchanger 20 Heat exchange device (chiller device) 21 First connecting line 23 Second expansion valve 31 Second connecting line 33 Third expansion valve 41 Third connecting line 43 Third valve 51 Fourth connecting line 53 Fourth expansion valve 61 Fifth connecting line 63 Fourth valve

Claims

[1] Heat pump system for a vehicle, comprising: an air conditioning unit having a compressor (10), a first heat exchanger (13), a second heat exchanger (14), a first expansion valve (15) and a third heat exchanger (16), which are connected by a refrigerant line (11) to circulate a refrigerant through the refrigerant line (11), and a heat exchange device (20) which is connected to the refrigerant line (11) by a first connecting line (21) and is designed to adjust the temperature of a coolant by heat exchange of the refrigerant supplied from the air conditioning unit with a coolant, wherein the air conditioning unit further comprises: a first valve (18) provided in the refrigerant line (11) between the first heat exchanger (13) and the second heat exchanger (14), a second valve (19) provided in the refrigerant line (11) between the third heat exchanger (16) and the compressor (10), a second expansion valve (23) provided in the first connecting line (21), a second connecting line (31) having a first end connected to the refrigerant line (11) between the first heat exchanger (13) and the second heat exchanger (14), and a second end connected to the refrigerant line (11) between the second heat exchanger (14) and the third heat exchanger (16), and a third expansion valve (33) provided in the second connecting line (31). [2] The heat pump system according to claim 1, wherein the air conditioning unit further comprises: a third connecting line (41) having a first end connected to the refrigerant line (11) between the compressor (10) and the first heat exchanger (13) and a second end connected to the refrigerant line (11) between the first heat exchanger (13) and the second heat exchanger (14), a third valve (43) provided in the third connecting line (41), a fourth connecting line (51) having a first end connected to the refrigerant line (11) between the second heat exchanger (14) and the third heat exchanger (16), and a second end connected to the refrigerant line (11) between the third heat exchanger (13) and the compressor (10), a fourth expansion valve (53) provided in the fourth connecting line (51), a fifth connecting line (61) having a first end connected to the refrigerant line (11) between the third heat exchanger (13) and the compressor (10), and a second end connected to the refrigerant line (10) between the first heat exchanger (13) and the second heat exchanger (14), and a fourth valve (63) provided in the fifth connecting line (61). [3] The heat pump system according to claim 2, wherein the air conditioning unit further comprises: an accumulator (17) which is provided in the refrigerant line (11) between the third heat exchanger (16) and the compressor (10), and an internal heat exchanger (17a) provided within the accumulator (17) and configured to allow the refrigerant supplied from the second heat exchanger (14) and the refrigerant supplied from the third heat exchanger (16) to exchange heat with each other and to supply a liquid refrigerant under the heat-exchanged refrigerant to the third heat exchanger (16). [4] Heat pump system according to claim 3, wherein in a heating mode of a vehicle interior: a section of the refrigerant line (11) which connects a first end of the first connecting line (21) to the second end of the second connecting line (31) is closed by operation of the first expansion valve (15), a section 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) is closed by operation of the first valve (18), a portion of the refrigerant line (11) connecting a second end of the fourth connecting line (51) and a second end of the first connecting line (21) is closed by operation of the second valve (19), the first connecting line (21) is opened by operation of the second expansion valve (23), the second connecting line (31) is opened by operation of the third expansion valve (33), the third connecting line (41) is closed by operation of the third valve (43), the fourth connecting line (51) is opened by operation of the fourth expansion valve (53), the fifth connecting line (61) is opened by operation of the fourth valve (63). [5] The heat pump system according to claim 4, wherein the fourth expansion valve (53) is configured to expand the refrigerant so that the expanded refrigerant is supplied to the second heat exchanger (14), the indoor heat exchanger (17a) and the heat exchange device (20), respectively. [6] Heat pump system according to claim 4 or 5, wherein: a part of the refrigerant from the refrigerant flowing from the third heat exchanger (16) into the fourth connecting line (51) flows into the second heat exchanger (14), and a remaining refrigerant from the refrigerant flowing from the third heat exchanger (16) into the fourth connecting line (51) flows into the indoor heat exchanger (17a). [7] Heat pump system according to one of claims 4 to 6, wherein: a part of the refrigerant from the refrigerant flowing out of the fourth expansion valve (53) flows through the indoor heat exchanger (17a) along the refrigerant line (11) and then flows into the heat exchange device (20), and the refrigerant discharged from the second heat exchanger (14) and the heat exchange device (20) flows through the indoor heat exchanger (17a) and the accumulator (17) and is then supplied to the compressor (10). [8] Heat pump system according to one of claims 4 to 7, wherein: the second expansion valve (23) supplies the refrigerant introduced through the first connecting line (21) to the heat exchange device (20) without expansion, and the third expansion valve (33) can supply the refrigerant introduced through the second connecting line (31) to the third heat exchanger (16) without expansion. [9] Heat pump system according to one of claims 3 to 8, wherein in a heating and dehumidification mode of a vehicle interior: a portion of the refrigerant line (11) connecting a first end of the first connecting line (21) and the second end of the second connecting line (31) is opened by operation of the first expansion valve (15), a section of the refrigerant line (11) connecting the first end of the second connecting line (31) and the second heat exchanger (14) is closed by operation of the first valve (18), the refrigerant line (11) connecting the third heat exchanger (16) and the accumulator (17) is opened by operation of the second valve (19). the refrigerant line (11) connecting the second heat exchanger (14) and the indoor heat exchanger (17a) is closed, the first connecting line (21) is opened by operation of the second expansion valve (23), the second connecting line (31) is opened by operation of the third expansion valve (33), the third connecting line (41) is closed by operation of the third valve (43), the fourth connecting line (51) is closed by operation of the fourth expansion valve (53), and the fifth connecting line (61) is closed by operation of the fourth valve (63). [10] Heat pump system according to claim 9, wherein the third expansion valve (33) is adapted to expand the refrigerant introduced through the second connecting line (31) from the first heat exchanger (13) and to supply the expanded refrigerant to the third heat exchanger (16) and the heat exchange device (20) respectively. [11] Heat pump system according to claim 9 or 10, wherein the first expansion valve (15) and the second expansion valve (23) are arranged to pass the introduced refrigerant without expansion. [12] Heat pump system according to one of claims 3 to 8, wherein when cooling of a battery module is required in a cooling mode of a vehicle interior: a section of the refrigerant line (11) connecting the compressor (10) and the first heat exchanger (13) and a section of the refrigerant line (11) connecting the first heat exchanger (13) and the second heat exchanger (14) are closed by operation of the first valve (18), the first connecting line (21) is opened by operation of the second expansion valve (23), the second connecting line (31) is closed by operation of the third expansion valve (33), the third connecting line (41) is opened by operation of the third valve (43), the fourth connecting line (51) is closed by operation of the fourth expansion valve (53), and the fifth connecting line (61) is closed by operation of the fourth valve (63). [13] The heat pump system according to claim 12, wherein the first expansion valve (15) is configured to expand the refrigerant introduced through the refrigerant line (11) and to supply the expanded refrigerant to the third heat exchanger (16), and the second expansion valve (23) is configured to expand the refrigerant introduced into the first connection line (21) and to supply the expanded refrigerant to the heat exchange device (20) to cool the battery module (5) using the coolant that has exchanged heat with the refrigerant in the heat exchange device (20). [14] Heat pump system according to claim 12 or 13, wherein: the refrigerant discharged from the compressor (10) flows along the third connecting line (41) into the second heat exchanger (14), a part of the refrigerant from the refrigerant discharged from the indoor heat exchanger (17a) flows into the heat exchange device (20) along the first connecting line (21), a remaining refrigerant from the refrigerant discharged from the indoor heat exchanger (17a) flows along the refrigerant line (11) into the first expansion valve (15), and the refrigerant discharged from the heat exchange device (20) and the refrigerant discharged from the third heat exchanger (16) flows along the refrigerant line (11) through the indoor heat exchanger (17a) and the accumulator (17) and is then supplied to the compressor (10). [15] Heat pump system according to one of claims 1 to 14, wherein the second heat exchanger (14) and the third heat exchanger (16) are arranged to cool or evaporate a refrigerant introduced therein. [16] Heat pump system according to one of claims 1 to 15, wherein a first end of the first connecting line (21) is connected to the refrigerant line (11) between the second heat exchanger (14) and the first expansion valve (15), and a second end of the first connecting line (21) is connected to the refrigerant line (11) between the third heat exchanger (16) and the compressor (10). [17] Heat pump system according to one of claims 1 to 16, wherein the refrigerant is an R744 refrigerant formed from carbon dioxide. [18] Heat pump system according to one of claims 1 to 17, wherein the heat exchange device (20) is connected to an electrical component (3) and a battery module (5) respectively associated by a first line (2) and a second line (4) which circulate the coolant. [19] Heat pump system according to one of claims 1 to 18, wherein: the first heat exchanger (13), the second heat exchanger (14) and the third heat exchanger (16) are air-cooled gas coolers which are designed to exchange heat between the refrigerant introduced therein and air, and the heat exchange device (20) is a water-cooled gas cooler which is designed to exchange heat between the refrigerant introduced therein and the coolant. [20] Heat pump system according to claim 2 or any one of claims 3 to 19 when dependent on claim 2, wherein the first expansion valve (15), the second expansion valve (23), the third expansion valve (33) and the fourth expansion valve (53) are electronic expansion valves arranged to selectively expand the refrigerant while controlling the flow movement of the refrigerant.

Images