Heat pump system for a vehicle

Abstract

This invention provides a heat pump system for vehicles that improves cooling and heating performance, and includes a gas injection device that selectively operates in the vehicle's interior air conditioning mode to increase refrigerant flow. When the external temperature is high or when using a refrigerant with high critical pressure and critical temperature, the heat pump system can prevent deterioration in the cooling performance of the vehicle interior by preventing the temperature of the refrigerant discharged from the compressor from becoming excessively high.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0180993, filed with the Korean Intellectual Property Office on December 6, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to heat pump systems for vehicles, and more specifically, to a heat pump system for vehicles capable of improving its cooling and heating performance. Background Technology

[0004] Air conditioning systems for vehicles include air conditioning units that circulate refrigerant to heat or cool the interior of the vehicle.

[0005] An air conditioning system is used to maintain a suitable temperature inside a vehicle to ensure a comfortable interior environment, regardless of changes in the outside temperature. The system is configured to heat or cool the vehicle interior by exchanging heat between the condenser and evaporator as the refrigerant discharged through the compressor passes through the condenser, receiver-drier, expansion valve, and evaporator, and then recirculates back to the compressor.

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

[0007] With increasing concern about energy efficiency and environmental pollution, there is a need to develop environmentally friendly vehicles that can substantially replace internal combustion engine vehicles. Environmentally friendly vehicles can be divided into electric vehicles that use fuel cells or electricity as a power source and hybrid vehicles that use engines and batteries.

[0008] Unlike the air conditioning in ordinary vehicles, these environmentally friendly electric or hybrid vehicles do not use a separate heater. The air conditioning used in these environmentally friendly vehicles is usually called a heat pump system.

[0009] Electric vehicles powered by fuel cells generate propulsion by converting the chemical reaction between oxygen and hydrogen into electrical energy. During this process, the chemical reaction within the fuel cell produces heat. Therefore, effectively removing this heat is essential to ensuring the performance of the fuel cell.

[0010] Furthermore, hybrid vehicles generate driving force by using an electric motor powered by electricity supplied from the aforementioned fuel cell or battery, in conjunction with an engine that runs on conventional fuels. Therefore, the heat generated from the fuel cell or battery and the electric motor must be effectively removed to ensure the performance of the electric motor.

[0011] Therefore, in hybrid or electric vehicles according to the prior art, the cooling device, heat pump system and battery cooling system should be configured as independent closed loops to prevent the electric motor, electrical components and the battery including the fuel cell from overheating.

[0012] Therefore, the size and weight of the cooling module located at the front of the vehicle increase, and the layout of the connecting pipes in the engine compartment that supply refrigerant and coolant to the various heat pump systems, cooling devices and battery cooling systems becomes more complicated.

[0013] Furthermore, since the battery cooling system, which heats or cools the battery according to the vehicle condition, is individually configured to obtain the battery's optimal performance, multiple valves are used to selectively interconnect the connecting pipes. Therefore, noise and vibration generated by the frequent opening and closing of the valves may be transmitted into the vehicle interior, thereby reducing the vehicle's ride comfort.

[0014] In addition, for heating the vehicle interior, heating performance may deteriorate due to insufficient heat source, power consumption may increase due to the use of electric heaters, and the power consumption of the compressor may also increase.

[0015] The information described in this background section is only for enhancing the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0016] The present invention provides a heat pump system for vehicles that can increase the flow of refrigerant by means of a gas injection device that operates selectively in the air conditioning mode inside the vehicle, thereby improving cooling and heating performance.

[0017] Furthermore, according to the present invention, when the external temperature is high or a refrigerant with a high critical pressure and critical temperature is used, the heat pump system for a vehicle can prevent the performance of cooling the vehicle interior from deteriorating by preventing the temperature of the refrigerant discharged from the compressor from becoming too high.

[0018] A heat pump system for a vehicle includes: a compressor configured to compress a refrigerant; a first heat exchanger connected to the compressor via a refrigerant line; and a first expansion valve connected to the first heat exchanger via a refrigerant line. The heat pump system also includes an evaporator connected to the first expansion valve via a refrigerant line, connected to the compressor via a refrigerant line, and configured to evaporate the supplied refrigerant. The heat pump system further includes a gas injection device disposed on the refrigerant line between the first heat exchanger and the first expansion valve, and configured to selectively expand the refrigerant supplied from the first heat exchanger and allow the expanded refrigerant to flow. The gas injection device is further configured to selectively supply a portion of the supplied refrigerant to the compressor to increase the flow rate of the refrigerant circulating through the refrigerant line, wherein the refrigerant flow is controlled by operational control of the gas injection device according to at least one mode for regulating the interior temperature of the vehicle.

[0019] The heat pump system may further include a connecting line, with a first end connected to a refrigerant line between a first heat exchanger and a first expansion valve, and a second end connected to a refrigerant line between a compressor and an evaporator. The heat pump system may also include a cooler disposed on the connecting line, configured to regulate the temperature of the coolant by exchanging heat with refrigerant introduced through the connecting line and selectively introduced coolant. The heat pump system may further include a second expansion valve disposed on the connecting line upstream of the cooler.

[0020] The gas injection device may include a gas-liquid separator disposed on the refrigerant line between the first heat exchanger and the first expansion valve. The gas injection device may also include a third expansion valve disposed on the refrigerant line upstream of the gas-liquid separator. The gas injection device may further include a first line, with a first end connected to the gas-liquid separator and a second end connected to the compressor. The gas injection device may include a fourth expansion valve disposed on the first line. The gas injection device may also include a second line, with a first end connected to the fourth expansion valve and a second end connected to the refrigerant line between the evaporator and the compressor.

[0021] The gas-liquid separator can operate when expanded refrigerant is supplied from the third expansion valve and is configured to supply gaseous refrigerant in the supplied refrigerant to the compressor through the first line to increase the flow rate of refrigerant circulating through the refrigerant line.

[0022] When the gas injection device needs to be operated, the third expansion valve can expand the refrigerant supplied through the refrigerant line and supply the expanded refrigerant to the gas-liquid separator.

[0023] In at least one mode of the gas injection device, the fourth expansion valve can close the portion of the first pipeline connected to the compressor, open the second pipeline, and cause the refrigerant introduced from the gas-liquid separator through the first pipeline to expand, so that the expanded refrigerant flows into the second pipeline.

[0024] In at least one mode, the fourth expansion valve can close the second line and allow refrigerant introduced from the gas-liquid separator through the first line to flow without expansion.

[0025] At least one mode may include a first mode for cooling the vehicle interior, wherein the gas injection device operates when the temperature of the refrigerant discharged from the compressor is greater than or equal to a critical temperature. At least one mode may include a second mode for cooling the vehicle interior, wherein the gas injection device operates when the temperature of the refrigerant discharged from the compressor is less than or equal to a critical temperature. At least one mode may include a third mode for cooling the battery module while simultaneously cooling the vehicle interior, wherein the gas injection device operates when the temperature of the refrigerant discharged from the compressor is greater than or equal to a critical temperature. At least one mode may include a fourth mode for heating the vehicle interior and operating the gas injection device.

[0026] In the first mode, the refrigerant line connecting the compressor, first heat exchanger, first expansion valve, and evaporator can be opened. The connecting line can be closed via the second expansion valve. The portion of the first line connecting the gas-liquid separator to the fourth expansion valve can be opened via the fourth expansion valve, and the remaining portion of the first line connecting the fourth expansion valve to the compressor can be closed via the fourth expansion valve. The second line can be opened via the fourth expansion valve. The first expansion valve expands the refrigerant introduced through the refrigerant line and supplies the expanded refrigerant to the evaporator. The third expansion valve expands the refrigerant introduced through the refrigerant line and supplies the expanded refrigerant to the gas-liquid separator via the refrigerant line. The fourth expansion valve expands the refrigerant introduced from the gas-liquid separator through the first line and allows the expanded refrigerant to flow along the second line. The gas-liquid separator supplies gaseous refrigerant from the internally introduced refrigerant to the compressor through the open portions of the first and second lines.

[0027] In the second mode, the refrigerant line connecting the compressor, the first heat exchanger, the first expansion valve, and the evaporator can be opened. The connecting line can be closed via the second expansion valve. The first line can be opened via the fourth expansion valve, and the second line can be closed via the fourth expansion valve. The first expansion valve expands the refrigerant introduced through the refrigerant line and supplies the expanded refrigerant to the evaporator. The third expansion valve expands the refrigerant introduced through the refrigerant line and supplies the expanded refrigerant to the gas-liquid separator through the refrigerant line. The fourth expansion valve allows the refrigerant introduced from the gas-liquid separator through the first line to flow without expansion. The gas-liquid separator supplies gaseous refrigerant from the internally introduced refrigerant to the compressor through the opened first line.

[0028] In the third mode, the refrigerant line connecting the compressor, the first heat exchanger, the first expansion valve, and the evaporator can be opened. The connecting line can be opened via the second expansion valve. The portion of the first line connecting the gas-liquid separator to the fourth expansion valve can be opened via the fourth expansion valve, and the remaining portion of the first line connecting the fourth expansion valve to the compressor can be closed via the fourth expansion valve. The second line can be opened via the fourth expansion valve. The first expansion valve expands the refrigerant introduced through the refrigerant line and supplies the expanded refrigerant to the evaporator. The second expansion valve expands the refrigerant introduced through the connecting line and supplies the expanded refrigerant to the cooler. The third expansion valve expands the refrigerant introduced through the refrigerant line and supplies the expanded refrigerant to the gas-liquid separator through the refrigerant line. The fourth expansion valve expands the refrigerant introduced from the gas-liquid separator through the first line and allows the expanded refrigerant to flow along the second line. The gas-liquid separator supplies gaseous refrigerant from the internally introduced refrigerant to the compressor through the opened portions of the first and second lines.

[0029] In the fourth mode, the portions of the refrigerant line connecting the compressor, the first heat exchanger, and the gas injection device can be opened. The portions of the refrigerant line connecting the gas injection device to the first end of the connecting line, and the portions of the refrigerant line connecting the second end of the connecting line to the compressor, can be opened. The portions of the refrigerant line connecting the evaporator to the first end of the connecting line, and the portions of the refrigerant line connecting the evaporator to the second end of the connecting line, can be closed by the first expansion valve. The connecting line can be opened by the second expansion valve. The first line can be opened by the fourth expansion valve. The second line can be closed by the fourth expansion valve. The second expansion valve allows the refrigerant introduced through the connecting line to expand and supplies the expanded refrigerant to the cooler. The third expansion valve allows the refrigerant introduced through the refrigerant line to expand and supplies the expanded refrigerant to the gas-liquid separator through the refrigerant line. The fourth expansion valve allows the refrigerant introduced from the gas-liquid separator through the first line to flow without expansion. The gas-liquid separator supplies gaseous refrigerant from the internally introduced refrigerant to the compressor through the opened first line.

[0030] The second and third expansion valves can be bidirectional electronic expansion valves, configured to selectively expand the refrigerant while controlling the flow of the supplied refrigerant. The fourth expansion valve can be a three-way electronic expansion valve, configured to selectively expand the refrigerant while controlling the flow of the refrigerant.

[0031] The heat pump system may also include a second heat exchanger located on the refrigerant line between the compressor and the first heat exchanger, and a receiver located on the refrigerant line between the evaporator and the compressor.

[0032] The first heat exchanger and cooler can be water-cooled heat exchangers, configured to exchange heat between internally introduced refrigerant and coolant, and the second heat exchanger can be air-cooled heat exchangers, configured to exchange heat between internally introduced refrigerant and air.

[0033] The heat pump system may also include an internal heat exchanger connected to a refrigerant line connecting the first heat exchanger and the first expansion valve, and to a refrigerant line connecting the evaporator and the compressor, and configured to exchange heat between refrigerant supplied from the first heat exchanger and refrigerant supplied from the evaporator.

[0034] The first heat exchanger can be connected to electrical components via a first coolant pipeline through which the first coolant circulates, and the cooler can be connected to the battery module via a second coolant pipeline through which the second coolant circulates.

[0035] As described above, the heat pump system for vehicles according to embodiments of the present invention improves cooling and heating performance by increasing the refrigerant flow rate through a gas injection device that operates selectively in the air conditioning mode inside the vehicle.

[0036] Furthermore, according to the present invention, when the external temperature is high or when a refrigerant with a high critical pressure and critical temperature is used, the performance of cooling the interior of the vehicle can be prevented from deteriorating by preventing the temperature of the refrigerant discharged from the compressor from becoming too high.

[0037] Furthermore, according to the present invention, by using a gas injection device, the required system components can be minimized while the system performance can be maximized, thus achieving system simplification and streamlining.

[0038] Furthermore, according to the present invention, the power consumption of the compressor in the vehicle interior cooling mode can be reduced, and the heating performance in the vehicle interior heating mode can be improved, thereby reducing unnecessary power consumption and increasing the overall driving distance of the vehicle.

[0039] Furthermore, according to the present invention, manufacturing costs and weight can be reduced and space utilization of the vehicle or vehicle system can be improved by simplifying the entire system. Attached Figure Description

[0040] Figure 1 This is a block diagram of a heat pump system for a vehicle according to an embodiment of the present invention.

[0041] Figure 2 This is an operational state diagram of a first mode of a heat pump system for a vehicle according to an embodiment of the present invention.

[0042] Figure 3 This is an operational state diagram of a second mode of a heat pump system for a vehicle according to an embodiment of the present invention.

[0043] Figure 4 This is an operational state diagram of the third mode of a heat pump system for a vehicle according to an embodiment of the present invention.

[0044] Figure 5 This is an operational state diagram of the fourth mode of a heat pump system for a vehicle according to an embodiment of the present invention.

[0045] Explanation of reference numerals in the attached figures

[0046] 2, 4: First and second coolant lines

[0047] 3: Electrical components

[0048] 5: Battery Module

[0049] 10: Compressor

[0050] 11: Refrigerant Piping

[0051] 12: First heat exchanger

[0052] 13: Second heat exchanger

[0053] 14: Internal heat exchanger

[0054] 15: First expansion valve

[0055] 16: Evaporator

[0056] 17: Liquid reservoir

[0057] 20: Cooler

[0058] 21: Connecting pipelines

[0059] 23: Second expansion valve

[0060] 30: Gas injection device

[0061] 31: Gas-liquid separator

[0062] 32: Third expansion valve

[0063] 33: First Pipeline

[0064] 34: Fourth expansion valve

[0065] 35: Second pipeline Detailed Implementation

[0066] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0067] The embodiments described in this specification and the structures shown in the accompanying drawings are merely exemplary embodiments of the present invention and do not cover the full scope of the present invention. Therefore, it should be understood that various equivalent forms and variations of the described embodiments may exist when applying the technical concept of this application.

[0068] For the purpose of clearly illustrating the invention, parts unrelated to the description have been omitted. Furthermore, throughout the specification, the same reference numerals refer to the same elements or equivalents.

[0069] Furthermore, the dimensions and thicknesses of the various components may be shown arbitrarily in the accompanying drawings, but the present invention is not limited thereto. For clarity, the thicknesses of layers, films, plates, regions, etc., are enlarged in the accompanying drawings.

[0070] Furthermore, unless explicitly stated to the contrary, the terms “comprising,” “having,” “including,” and variations thereof, such as “containing” or “comprise,” should be understood to mean that the said element is included, but not that any other element is excluded.

[0071] Furthermore, the various terms used in this specification, such as “…unit,” “…device,” “…section,” “…component,” and “…building,” etc., refer to a unit of integrated elements that performs at least one function or operation. When a component, device, unit, module, controller, detector, element, etc., of the present invention is described as having a purpose or performing an operation or function, that component, device, unit, module, controller, detector, or element shall be considered herein as “configured to” satisfy that purpose or perform that operation or function. The present invention describes a controller and a data detector for a cooling system. Controllers, detectors, or other such components may be embodied individually or included as part of a controller or component in a processor and, for example, a memory in a non-transitory computer-readable medium.

[0072] Figure 1 This is a block diagram of a heat pump system for a vehicle according to an embodiment of the present invention.

[0073] When cooling or heating the interior of a vehicle, the heat pump system for a vehicle according to an embodiment of the present invention can increase the flow of refrigerant by applying a gas injection device 30 that operates selectively in a selected air conditioning mode inside the vehicle, thereby improving the cooling and heating performance of the vehicle.

[0074] Furthermore, when the external temperature is high or when a refrigerant with a high critical pressure and critical temperature is used, the heat pump system according to an embodiment of the present invention can prevent the temperature of the refrigerant discharged from the compressor 10 from being too high, thereby preventing the deterioration of the cooling performance of the vehicle interior.

[0075] A refrigerant with high critical pressure and critical temperature can be R744 refrigerant.

[0076] R744 refrigerant can be composed of carbon dioxide with an ozone depletion potential (ODP) of 0 and a global warming potential (GWP) of 1.

[0077] When using R744 refrigerant, which is a natural refrigerant that uses carbon dioxide, the heat pump system can operate in a supercritical cycle, in which the pressure and temperature of the refrigerant are higher than the critical pressure and critical temperature, thereby maximizing cooling and heating performance.

[0078] Reference Figure 1 The heat pump system may include a compressor 10, a first heat exchanger 12, a second heat exchanger 13, an internal heat exchanger 14, a first expansion valve 15, an evaporator 16, a cooler 20, a connecting pipeline 21, a second expansion valve 23, and a gas injection device 30.

[0079] The compressor 10 can compress the supplied refrigerant and cause the compressed refrigerant to flow along the refrigerant line 11, so that the refrigerant circulates along the refrigerant line 11.

[0080] The first heat exchanger 12 can be connected to the compressor 10 via the refrigerant line 11. The first heat exchanger 12 can condense the supplied refrigerant by exchanging heat with the coolant.

[0081] When using R744 refrigerant, since R744 is a supercritical refrigerant and does not undergo a phase change like conventional refrigerants, the term "gas cooling" can be used instead of "condensation".

[0082] The first heat exchanger 12 can be connected to the electrical component 3 via a first coolant line 2 through which coolant circulates. A water pump (not shown) can be installed on the first coolant line 2, and the coolant can be selectively circulated by the operation of the water pump, thereby causing the coolant to flow through the coolant line.

[0083] Electrical component 3 may include power conversion devices, such as power control unit (EPCU), motor, inverter, on-board charger (OBC) and / or automatic driving controller, etc.

[0084] The electrical component 3 configured in this way can be connected to the first coolant line 2 for water cooling.

[0085] Therefore, the first heat exchanger 12 can regulate the temperature of the electrical component 3 by using a coolant that undergoes superheat exchange with the refrigerant, and can recover the waste heat of the electrical component 3.

[0086] The second heat exchanger 13 can be installed on the refrigerant line 11 between the compressor 10 and the first heat exchanger 12, i.e., connected to or installed along the refrigerant line 11. The second heat exchanger 13 can condense (or cool) the refrigerant by exchanging heat with the air.

[0087] In other words, the second heat exchanger 13 can be an air-cooled heat exchanger configured to exchange heat between the refrigerant introduced inside and the air.

[0088] In an embodiment of the present invention, the first expansion valve 15 can be connected to the first heat exchanger 12 via a refrigerant line 11. The first expansion valve 15 can selectively expand the introduced refrigerant.

[0089] The evaporator 16 can be connected to the first expansion valve 15 via a refrigerant line 11. Furthermore, the evaporator 16 can be connected to the compressor 10 via a refrigerant line 11. The evaporator 16 can evaporate the refrigerant supplied from the first expansion valve 15 by exchanging heat with ambient air.

[0090] Evaporator 16 can be installed within a heating, ventilation, and air conditioning (HVAC) module (not shown).

[0091] Therefore, the air passing through evaporator 16 can be cooled by the low-temperature refrigerant supplied to evaporator 16 as it passes through evaporator 16. The cooled air can then be introduced into the vehicle interior to cool the vehicle interior.

[0092] In other words, the evaporator 16 can be an air-cooled heat exchanger configured to exchange heat between the refrigerant introduced inside and the air.

[0093] The internal heat exchanger 14 can be connected to the refrigerant line 11 connecting the first heat exchanger 12 and the first expansion valve 15, and the refrigerant line 11 connecting the evaporator 16 and the compressor 10, respectively.

[0094] The internal heat exchanger 14 can exchange heat between the refrigerant supplied from the first heat exchanger 12 and the refrigerant supplied from the evaporator 16.

[0095] In other words, the internal heat exchanger 14 can exchange heat between the refrigerant condensed (or cooled) in the first heat exchanger 12 and the low-temperature refrigerant discharged from the evaporator 16, and can supply the heat-exchanged refrigerant to the compressor 10 and the evaporator 16 respectively.

[0096] The heat pump system may also include a liquid receiver 17.

[0097] The receiver 17 can be installed on the refrigerant line 11 between the evaporator 16 and the compressor 10. In one example, the receiver 17 can be installed on the refrigerant line 11 between the internal heat exchanger 14 and the compressor 10.

[0098] The receiver 17 can supply only gaseous refrigerant to the compressor 10, thereby improving the efficiency and durability of the compressor 10.

[0099] In an embodiment of the invention, the cooler 20 can be connected to the battery module 5 via a second coolant pipeline 4 through which the coolant circulates. Therefore, the coolant can selectively circulate through the cooler 20.

[0100] In other words, when cooling the battery module 5 while cooling the vehicle interior, or when recovering the waste heat of the battery module 5 while heating the vehicle interior, the second coolant line 4 can be opened to connect the cooler 20 to the battery module 5.

[0101] The cooler 20 can regulate the temperature of the coolant by exchanging heat between the supplied refrigerant and the coolant.

[0102] In other words, the coolant after heat exchange in the cooler 20 can be circulated to the battery module 5 through the second coolant line 4. A water pump (not shown) can be installed on the second coolant line 4, and the coolant can be selectively circulated by the operation of the water pump.

[0103] The cooler 20 can regulate the temperature of the coolant selectively supplied through the second coolant line 4 by exchanging heat between the refrigerant supplied from the first heat exchanger 12 through the internal heat exchanger 14 and the coolant.

[0104] In other words, the first heat exchanger 12 and the cooler 20 can be water-cooled heat exchangers configured to exchange heat between the refrigerant and coolant introduced internally.

[0105] The cooler 20 can be connected to the refrigerant line 11 via the connecting line 21.

[0106] The first end of the connecting line 21 can be connected to the refrigerant line 11 between the first heat exchanger 12 and the first expansion valve 15.

[0107] Furthermore, the second end of the connecting line 21 can be connected to the refrigerant line 11 between the evaporator 16 and the compressor 10. In one example, the second end of the connecting line 21 can be connected to the refrigerant line 11 between the evaporator 16 and the internal heat exchanger 14.

[0108] The cooler 20 can regulate the temperature of the coolant by exchanging heat between the coolant selectively introduced through the second coolant line 4 and the refrigerant selectively supplied from the first heat exchanger 12.

[0109] Therefore, the coolant that undergoes superheat exchange with the refrigerant in the cooler 20 can be selectively supplied to the battery module 5 to regulate the temperature of the battery module 5.

[0110] The cooler 20 configured in this way can be connected in parallel with the evaporator 16 via connecting pipe 21.

[0111] In an embodiment of the present invention, based on the flow direction of the refrigerant, the second expansion valve 23 may be installed on the connecting pipeline 21 at the upstream end of the cooler 20.

[0112] When cooling the battery module 5 by using the coolant that has exchanged heat with the refrigerant while cooling the vehicle interior, or when heating the vehicle interior, the second expansion valve 23 can expand the refrigerant introduced through the connecting line 21 and allow the expanded refrigerant to flow into the cooler 20.

[0113] In other words, while cooling the battery module 5 inside the vehicle, the second expansion valve 23 can expand the refrigerant introduced through the connecting line 21 to reduce its temperature, and allow the expanded refrigerant to flow into the cooler 20, thereby further reducing the temperature of the refrigerant passing through the cooler 20.

[0114] Therefore, the coolant whose temperature drops when passing through the cooler 20 can be introduced into the battery module 5, thereby achieving more efficient cooling.

[0115] When the waste heat generated by the battery module 5 is recovered while heating the interior of the vehicle, the second expansion valve 23 can expand the refrigerant introduced through the connecting line 21 and supply the expanded refrigerant to the cooler 20.

[0116] Therefore, the cooler 20 can evaporate the refrigerant by exchanging heat with the refrigerant supplied through the second refrigerant line 4.

[0117] The cooler 20 can recover waste heat from the battery module 5 while exchanging heat between the refrigerant supplied from the second expansion valve 23 and the refrigerant supplied from the battery module 5.

[0118] The second expansion valve 23 configured in this way can be a bidirectional electronic expansion valve, which is configured to selectively expand the refrigerant while controlling the flow of the supplied refrigerant.

[0119] The upstream end of the cooler 20 can be set based on the flow direction of the refrigerant. Based on the flow direction of the refrigerant along the connecting pipeline 21, the location where the refrigerant is introduced into the cooler 20 can be defined as the upstream end of the cooler 20, and the location where the refrigerant is discharged from the cooler 20 can be defined as the downstream end of the cooler 20.

[0120] Furthermore, the gas injection device 30 can be connected to the refrigerant line 11 between the first heat exchanger 12 and the first expansion valve 15. In one example, the gas injection device 30 can be connected to the refrigerant line 11 between the internal heat exchanger 14 and the first expansion valve 15.

[0121] The gas injection device 30 can selectively expand the refrigerant supplied from the first heat exchanger 12 and allow the expanded refrigerant to flow, and can selectively supply a portion of the supplied refrigerant to the compressor 10 to increase the flow rate of the refrigerant circulating through the refrigerant line 11.

[0122] The gas injection device 30 configured in this way can operate selectively when cooling or heating the interior of the vehicle.

[0123] The gas injection device 30 may include a gas-liquid separator 31, a third expansion valve 32, a first pipeline 33, a fourth expansion valve 34, and a second pipeline 35.

[0124] The gas-liquid separator 31 can be installed on the refrigerant line 11 between the first heat exchanger 12 and the first expansion valve 15.

[0125] Based on the refrigerant flow direction, the third expansion valve 32 can be installed on the refrigerant line 11 at the upstream end of the gas-liquid separator 31.

[0126] When the gas injection device 30 needs to be operated, the third expansion valve 32 can expand the refrigerant supplied from the first heat exchanger 12 through the internal heat exchanger 14 and through the refrigerant line 11, and can supply the expanded refrigerant to the gas-liquid separator 31.

[0127] The third expansion valve 32 configured in this way can be a bidirectional electronic expansion valve, which is configured to selectively expand the refrigerant while controlling the flow of the refrigerant.

[0128] In an embodiment of the present invention, the upstream end of the gas-liquid separator 31 can be set based on the flow direction of the refrigerant. Based on the flow direction of the refrigerant along the refrigerant line 11, the position where the refrigerant is introduced into the gas-liquid separator 31 can be defined as the upstream end of the gas-liquid separator 31, and the position where the refrigerant is discharged from the gas-liquid separator 31 can be defined as the downstream end of the gas-liquid separator 31.

[0129] In an embodiment of the present invention, the first end of the first pipeline 33 may be connected to the gas-liquid separator 31. The second end of the first pipeline 33 may be connected to the compressor 10.

[0130] In other words, the first pipeline 33 can connect the gas-liquid separator 31 to the compressor 10, so that the gaseous refrigerant separated in the gas-liquid separator 31 can be selectively introduced into the compressor 10.

[0131] When the expanded refrigerant is supplied from the third expansion valve 32, the gas-liquid separator 31 can be operated.

[0132] The gas-liquid separator 31 can supply gaseous refrigerant from the supplied refrigerant to the compressor 10 through the first pipeline 33, thereby increasing the flow rate of refrigerant circulating through the refrigerant pipeline 11.

[0133] In an embodiment of the present invention, a fourth expansion valve 34 may be disposed on the first pipeline 33. The fourth expansion valve 34 may selectively expand the introduced refrigerant.

[0134] Furthermore, the first end of the second pipeline 35 can be connected to the fourth expansion valve 34. The second end of the second pipeline 35 can be connected to the refrigerant pipeline 11 between the evaporator 16 and the compressor 10.

[0135] In other words, the fourth expansion valve 34 can be a three-way electronic expansion valve configured to selectively expand the refrigerant while controlling the flow of the refrigerant.

[0136] In at least one mode for regulating the interior temperature of the vehicle, the fourth expansion valve 34 can close the portion of the first line 33 connected to the compressor 10 and open the second line 35.

[0137] The fourth expansion valve 34 can expand the refrigerant introduced from the gas-liquid separator 31 through the first pipeline 33, and allow the expanded refrigerant to flow to the second pipeline 35.

[0138] In the gas injection device 30 configured in this way, when the expanded refrigerant is supplied, the gas-liquid separator 31 can supply gaseous refrigerant to the compressor 10 through the first pipeline 33.

[0139] The gas-liquid separator 31 can discharge liquid refrigerant to the refrigerant line 11.

[0140] In other words, when the expanded refrigerant is supplied to the gas-liquid separator 31, the gas-liquid separator 31 can supply the gaseous refrigerant in the supplied refrigerant to the compressor 10 through the first pipeline 33, so as to increase the total flow rate of the refrigerant circulating through the refrigerant pipeline 11.

[0141] In such a heat pump system, the flow of refrigerant can be controlled by the operation control of the gas injection device 30 according to at least one mode for regulating the interior temperature of the vehicle.

[0142] At least one mode may include a first mode, a second mode, a third mode, and a fourth mode.

[0143] In the first mode, when the temperature of the refrigerant discharged from the compressor 10 is greater than or equal to the critical temperature, the gas injection device 30 can be operated and the interior of the vehicle can be cooled.

[0144] In the second mode, when the temperature of the refrigerant discharged from the compressor 10 is less than or equal to the critical temperature, the gas injection device 30 can be operated and the interior of the vehicle can be cooled.

[0145] In the third mode, when the temperature of the refrigerant discharged from the compressor 10 is greater than or equal to the critical temperature, the gas injection device 30 can be operated, and the battery module 5 can be cooled while cooling the interior of the vehicle.

[0146] In addition, in the fourth mode, the gas injection device 30 can be operated and the interior of the vehicle can be heated.

[0147] The following is for reference Figures 2 to 5 The operation and function of a heat pump system for a vehicle, configured as described above, are explained in detail according to an embodiment of the present invention.

[0148] The following text refers to Figure 2The operation of the gas injection device 30 in the first mode for cooling the vehicle interior is described in detail when the temperature of the refrigerant discharged from the compressor 10 is greater than or equal to the critical temperature.

[0149] Figure 2 This is an operational state diagram of a first mode of a heat pump system for a vehicle according to an embodiment of the present invention.

[0150] Reference Figure 2 In the first mode, the refrigerant line 11 that interconnects the compressor 10, the first heat exchanger 12, the first expansion valve 15 and the evaporator 16 can be opened.

[0151] The connecting line 21 can be closed by the second expansion valve 23.

[0152] In an embodiment of the present invention, the portion of the first pipeline 33 that connects the gas-liquid separator 31 and the fourth expansion valve 34 can be opened by the fourth expansion valve 34.

[0153] Furthermore, the remaining portion of the first pipeline 33 connecting the fourth expansion valve 34 and the compressor 10 can be closed via the fourth expansion valve 34.

[0154] In addition, the second pipeline 35 can be opened via the fourth expansion valve 34.

[0155] In this state, the refrigerant compressed in compressor 10 can be introduced into the second heat exchanger 13 and the first heat exchanger 12 along refrigerant line 11. The first coolant line 2 can be opened, thereby supplying coolant to electronic components 3.

[0156] Therefore, the second heat exchanger 13 can condense (or cool) the refrigerant by using air introduced from the outside while the vehicle is in motion. The first heat exchanger 12 can condense (or cool) the refrigerant by using coolant supplied from the electronic component 3.

[0157] The refrigerant condensed (or cooled) in the first heat exchanger 12 can be introduced into the internal heat exchanger 14 along the refrigerant line 11. Thereafter, the refrigerant that has passed through the internal heat exchanger 14 can be introduced into the third expansion valve 32.

[0158] The third expansion valve 32 can expand the refrigerant introduced through the refrigerant line 11, and can supply the expanded refrigerant to the gas-liquid separator 31 through the refrigerant line 11.

[0159] The gas-liquid separator 31 can supply gaseous refrigerant from the internally introduced refrigerant to the fourth expansion valve 34 through the first pipeline 33.

[0160] The fourth expansion valve 34 can expand the refrigerant introduced from the gas-liquid separator 31 through the first pipeline 33, and can make the expanded refrigerant flow along the second pipeline 35.

[0161] Therefore, the refrigerant discharged from the gas-liquid separator 31 into the first line 33 can have a lower pressure and temperature when it expands in the fourth expansion valve 34. The refrigerant with reduced pressure and temperature can then flow along the second line 35.

[0162] In other words, the gas-liquid separator 31 can supply gaseous refrigerant from the internally introduced refrigerant to the compressor 10 through the open portions of the first pipeline 33 and the second pipeline 35.

[0163] The refrigerant flowing through the second line 35 can be introduced into the compressor 10 together with the refrigerant flowing through the refrigerant line 11 connected to the compressor 10 via the receiver 17, thereby increasing the flow rate of the refrigerant circulating through the refrigerant line 11.

[0164] Because the refrigerant, whose pressure and temperature decrease as it passes through the fourth expansion valve 34, is introduced into the compressor 10 along with the refrigerant flowing through the refrigerant line 11, the overall temperature of the refrigerant discharged from the compressor 10 may decrease.

[0165] In other words, through this operation, the gas injection device 30 can increase the flow rate of refrigerant circulating through the refrigerant line 11 and reduce the temperature of the refrigerant discharged from the compressor 10, thereby preventing the deterioration of the cooling performance of the vehicle interior due to the decreased operating performance of the compressor 10.

[0166] The gas-liquid separator 31 can supply liquid refrigerant from the internally introduced refrigerant to the first expansion valve 15 through the refrigerant line 11.

[0167] The first expansion valve 15 can expand the refrigerant introduced through the refrigerant line 11 and supply the expanded refrigerant to the evaporator 16.

[0168] In this state, the ambient air introduced into the HVAC module (not shown) can be cooled by the low-temperature refrigerant introduced into the evaporator 16 as it passes through the evaporator 16. The cooled ambient air can then be directly introduced into the vehicle interior to cool the vehicle interior.

[0169] In addition, the refrigerant that has passed through the evaporator 16 can be introduced into the internal heat exchanger 14 along the refrigerant line 11.

[0170] The internal heat exchanger 14 can exchange heat between the refrigerant supplied from the first heat exchanger 12 and the refrigerant supplied from the evaporator 16.

[0171] In other words, the internal heat exchanger 14 can exchange heat between the refrigerant condensed (or cooled) in the first heat exchanger 12 and the low-temperature refrigerant discharged from the evaporator 16, and can supply the heat-exchanged refrigerant to the compressor 10 and the third expansion valve 32 respectively.

[0172] Furthermore, the refrigerant from the evaporator 16, having passed through the internal heat exchanger 14, can be introduced into the receiver 17 along the refrigerant line 11 via the second line 35, together with the refrigerant flowing through the refrigerant line 11. Afterward, the refrigerant can be introduced into the compressor 10 via the receiver 17.

[0173] The refrigerant compressed in the compressor 10 can travel along the refrigerant line 11 through the second heat exchanger 13 and then be supplied to the first heat exchanger 12.

[0174] The heat pump system can repeat the above process.

[0175] While repeating the above operations, the heat pump system can increase the flow rate of refrigerant flowing along the refrigerant line 11, and can reduce the temperature of the additional refrigerant supplied to the compressor 10 by controlling the operation of the gas injection device 30.

[0176] Therefore, when the temperature of the refrigerant discharged from the compressor 10 is greater than or equal to the critical temperature, the heat pump system can reduce the temperature of the refrigerant discharged from the compressor 10, thereby maintaining the operating performance of the compressor 10 and preventing the performance of cooling the interior of the vehicle from deteriorating.

[0177] In addition, the heat pump system can increase the flow rate of refrigerant along the refrigerant line 11, thereby improving the overall cooling performance and efficiency of the system.

[0178] The following text refers to Figure 3 In an embodiment of the present invention, the operation of the gas injection device 30 in a second mode for cooling the interior of a vehicle when the temperature of the refrigerant discharged from the compressor 10 is less than or equal to the critical temperature will be described in detail.

[0179] Figure 3 This is an operational state diagram of a second mode of a heat pump system for a vehicle according to an embodiment of the present invention.

[0180] Reference Figure 3 In the second mode, the refrigerant line 11 that interconnects the compressor 10, the first heat exchanger 12, the first expansion valve 15 and the evaporator 16 can be opened.

[0181] The connecting line 21 can be closed by the second expansion valve 23.

[0182] In an embodiment of the present invention, the first pipeline 33 can be opened by the fourth expansion valve 34.

[0183] The second pipeline 35 can be closed via the fourth expansion valve 34.

[0184] In this state, the refrigerant compressed in compressor 10 can be introduced into the second heat exchanger 13 and the first heat exchanger 12 along refrigerant line 11. The first coolant line 2 can be opened, thereby supplying coolant to electrical components 3.

[0185] Therefore, the second heat exchanger 13 can condense (or cool) the refrigerant by using air introduced from the outside when the vehicle is in motion. The first heat exchanger 12 can condense (or cool) the refrigerant by using coolant supplied from the electrical component 3.

[0186] The refrigerant condensed (or cooled) in the first heat exchanger 12 can be introduced into the internal heat exchanger 14 along the refrigerant line 11. Thereafter, the refrigerant that has passed through the internal heat exchanger 14 can be introduced into the third expansion valve 32.

[0187] The third expansion valve 32 can expand the refrigerant introduced through the refrigerant line 11, and can supply the expanded refrigerant to the gas-liquid separator 31 through the refrigerant line 11.

[0188] The gas-liquid separator 31 can supply gaseous refrigerant from the internally introduced refrigerant to the fourth expansion valve 34 through the first pipeline 33.

[0189] The fourth expansion valve 34 allows the refrigerant introduced from the gas-liquid separator 31 through the first line 33 to flow without expansion.

[0190] Therefore, the refrigerant discharged from the gas-liquid separator 31 can be supplied to the compressor 10 through the first line 33 without expansion.

[0191] In other words, the gas-liquid separator 31 can supply gaseous refrigerant from the internally introduced refrigerant to the compressor 10 through the opened first pipeline 33.

[0192] Through this operation, the gas injection device 30 can cause the gaseous refrigerant discharged from the gas-liquid separator 31 to flow back to the compressor 10 through the first line 33, thereby increasing the flow rate of the refrigerant circulating through the refrigerant line 11.

[0193] The gas-liquid separator 31 can supply liquid refrigerant from the internally introduced refrigerant to the first expansion valve 15 through the refrigerant line 11.

[0194] The first expansion valve 15 can expand the refrigerant introduced through the refrigerant line 11 and supply the expanded refrigerant to the evaporator 16.

[0195] In this state, the ambient air introduced into the HVAC module (not shown) can be cooled by the low-temperature refrigerant introduced into the evaporator 16 as it passes through the evaporator 16. The cooled ambient air can then be directly introduced into the vehicle interior to cool the vehicle interior.

[0196] In addition, the refrigerant that has passed through the evaporator 16 can be introduced into the internal heat exchanger 14 along the refrigerant line 11.

[0197] The internal heat exchanger 14 can exchange heat between the refrigerant supplied by the first heat exchanger 12 and the refrigerant supplied from the evaporator 16.

[0198] In other words, the internal heat exchanger 14 can exchange heat between the refrigerant condensed (or cooled) in the first heat exchanger 12 and the low-temperature refrigerant discharged from the evaporator 16, and can supply the heat-exchanged refrigerant to the compressor 10 and the third expansion valve 32 respectively.

[0199] Furthermore, the refrigerant that has passed through the internal heat exchanger 14 from the evaporator 16 can be introduced into the receiver 17 along the refrigerant line 11. Afterward, the refrigerant can be introduced into the compressor 10 via the receiver 17.

[0200] In other words, the refrigerant that has passed through the receiver 17 and the refrigerant supplied from the gas-liquid separator 31 through the first pipeline 33 can be introduced into the compressor 10. The introduced refrigerant can be compressed by the compressor 10.

[0201] The refrigerant compressed in the compressor 10 can travel along the refrigerant line 11 through the second heat exchanger 13 and then be supplied to the first heat exchanger 12.

[0202] The heat pump system can repeat the above process.

[0203] While repeating the above operations, the heat pump system can increase the flow rate of refrigerant flowing along refrigerant line 11.

[0204] Furthermore, the internal heat exchanger 14 can exchange heat between the refrigerant condensed (or cooled) in the first heat exchanger 12 and the refrigerant introduced from the evaporator 16, thereby further improving the degree of condensation (or cooling level) of the refrigerant.

[0205] Thus, since the gas injection device 30 injects refrigerant with increased condensation by controlling the flow of refrigerant, the subcooling of the refrigerant discharged from the first heat exchanger 12 is increased.

[0206] When the subcooling of the refrigerant discharged from the first heat exchanger 12 increases, the evaporator 16 may have a significantly increased enthalpy difference level, and the cooling load may be reduced to a minimum.

[0207] Therefore, when the temperature of the refrigerant discharged from the compressor 10 is less than or equal to the critical temperature, the heat pump system can control the flow of the refrigerant discharged from the first heat exchanger 12 through the operation control of the gas injection device 30, thereby cooling the vehicle interior more effectively.

[0208] In addition, the heat pump system can increase the flow rate of refrigerant along the refrigerant line 11, thereby improving the overall cooling performance and efficiency of the system.

[0209] The following text refers to Figure 4 The operation of the gas injection device 30 in a third mode, which operates to cool the battery module 5 while simultaneously cooling the vehicle interior, is described in detail in an embodiment of the present invention when the temperature of the refrigerant discharged from the compressor 10 is greater than or equal to the critical temperature.

[0210] Figure 4 This is an operational state diagram of the third mode of a heat pump system for a vehicle according to an embodiment of the present invention.

[0211] Reference Figure 4 In the third mode, the refrigerant line 11 that interconnects the compressor 10, the first heat exchanger 12, the first expansion valve 15 and the evaporator 16 can be opened.

[0212] The connecting line 21 can be opened via the second expansion valve 23.

[0213] In an embodiment of the present invention, the portion of the first pipeline 33 that connects the gas-liquid separator 31 and the fourth expansion valve 34 can be opened by the fourth expansion valve 34.

[0214] Furthermore, the remaining portion of the first pipeline 33 connecting the fourth expansion valve 34 and the compressor 10 can be closed via the fourth expansion valve 34.

[0215] In addition, the second pipeline 35 can be opened via the fourth expansion valve 34.

[0216] In this state, the refrigerant compressed in compressor 10 can be introduced into the second heat exchanger 13 and the first heat exchanger 12 along refrigerant line 11. The first coolant line 2 can be opened, thereby supplying coolant to electronic components 3.

[0217] Therefore, the second heat exchanger 13 can condense (or cool) the refrigerant by using air introduced from the outside while the vehicle is in motion. The first heat exchanger 12 can condense (or cool) the refrigerant by using coolant supplied from the electronic component 3.

[0218] The refrigerant condensed (or cooled) in the first heat exchanger 12 can be introduced into the internal heat exchanger 14 along the refrigerant line 11. Thereafter, the refrigerant that has passed through the internal heat exchanger 14 can be introduced into the third expansion valve 32.

[0219] The third expansion valve 32 can expand the refrigerant introduced through the refrigerant line 11, and can supply the expanded refrigerant to the gas-liquid separator 31 through the refrigerant line 11.

[0220] The gas-liquid separator 31 can supply gaseous refrigerant from the internally introduced refrigerant to the fourth expansion valve 34 through the first pipeline 33.

[0221] The fourth expansion valve 34 can expand the refrigerant introduced from the gas-liquid separator 31 through the first pipeline 33, and can make the expanded refrigerant flow along the second pipeline 35.

[0222] Therefore, the refrigerant discharged from the gas-liquid separator 31 into the first line 33 can have a lower pressure and temperature when it expands in the fourth expansion valve 34. The refrigerant with reduced pressure and temperature can then flow along the second line 35.

[0223] In other words, the gas-liquid separator 31 can supply gaseous refrigerant from the internally introduced refrigerant to the compressor 10 through the open portions of the first pipeline 33 and the second pipeline 35.

[0224] The refrigerant flowing through the second line 35 can be introduced into the compressor 10 together with the refrigerant flowing through the refrigerant line 11 connected to the compressor 10 via the receiver 17, thereby increasing the flow rate of the refrigerant circulating through the refrigerant line 11.

[0225] Because the refrigerant, whose pressure and temperature have decreased when passing through the fourth expansion valve 34, is introduced into the compressor 10 along with the refrigerant flowing through the refrigerant line 11, the overall temperature of the refrigerant discharged from the compressor 10 may decrease.

[0226] In other words, through this operation, the gas injection device 30 can increase the flow rate of refrigerant circulating through the refrigerant line 11 and reduce the temperature of the refrigerant discharged from the compressor 10, thereby preventing the deterioration of the cooling performance of the vehicle interior due to the decline in the operating performance of the compressor 10.

[0227] The refrigerant discharged from the gas-liquid separator 31 through the refrigerant line 11 can be introduced into the first expansion valve 15 and the second expansion valve 23 respectively along the refrigerant line 11 and the connecting line 21.

[0228] The first expansion valve 15 can expand the refrigerant introduced through the refrigerant line 11 and supply the expanded refrigerant to the evaporator 16.

[0229] In this state, the ambient air introduced into the HVAC module (not shown) can be cooled by the low-temperature refrigerant introduced into the evaporator 16 as it passes through the evaporator 16. The cooled ambient air can then be directly introduced into the vehicle interior to cool the vehicle interior.

[0230] The second expansion valve 23 can expand the refrigerant introduced through the connecting line 21 and supply the expanded refrigerant to the cooler 20.

[0231] The refrigerant introduced into the cooler 20 can cool the coolant while exchanging heat with the coolant supplied from the battery module 5 through the second coolant line 4.

[0232] The coolant cooled in the cooler 20 can be supplied to the battery module 5 along the second coolant line 4. Therefore, the battery module 5 can be effectively cooled by the coolant cooled in the cooler 20.

[0233] In other words, the coolant circulating through the second coolant line 4 can effectively cool the battery module 5 while repeating the above operations.

[0234] In addition, the refrigerant passing through the evaporator 16 and the cooler 20 can be introduced into the internal heat exchanger 14 along the refrigerant line 11.

[0235] The internal heat exchanger 14 can exchange heat between the refrigerant supplied from the first heat exchanger 12 and the refrigerant supplied from the evaporator 16.

[0236] In other words, the internal heat exchanger 14 can exchange heat between the refrigerant condensed (or cooled) in the first heat exchanger 12 and the low-temperature refrigerant discharged from the evaporator 16 and the cooler 20 respectively, and can supply the heat-exchanged refrigerant to the compressor 10 and the third expansion valve 32 respectively.

[0237] Furthermore, the refrigerant that has passed through the internal heat exchanger 14 from the evaporator 16 can be introduced into the receiver 17 along the refrigerant line 11 via the second line 35, together with the refrigerant flowing through the refrigerant line 11. Afterward, the refrigerant can be introduced into the compressor 10 via the receiver 17.

[0238] The refrigerant compressed in the compressor 10 can travel along the refrigerant line 11 through the second heat exchanger 13 and then be supplied to the first heat exchanger 12.

[0239] The heat pump system can repeat the above process.

[0240] While repeating the above operations, the heat pump system can increase the flow rate of refrigerant flowing along the refrigerant line 11, and can reduce the temperature of the additional refrigerant supplied to the compressor 10 by controlling the operation of the gas injection device 30.

[0241] Therefore, when the temperature of the refrigerant discharged from the compressor 10 is greater than or equal to the critical temperature, the heat pump system can reduce the temperature of the refrigerant discharged from the compressor 10, thereby maintaining the operating performance of the compressor 10 and preventing the performance of cooling the interior of the vehicle from deteriorating.

[0242] In addition, the heat pump system can increase the flow rate of refrigerant along the refrigerant line 11, thereby improving the overall cooling performance and efficiency of the system.

[0243] The heat pump system can effectively cool the battery module 5 by using a low-temperature coolant cooled in the cooler 20.

[0244] In an embodiment of the invention, when the temperature of the refrigerant discharged from the compressor 10 is greater than or equal to the critical temperature, the gas injection device 30 is operated to cool the battery module 5 while simultaneously cooling the vehicle interior. However, the invention is not limited thereto.

[0245] When the temperature of the refrigerant discharged from the compressor 10 is less than or equal to the critical temperature, the gas injection device 30 can be operated in the heat pump system to cool the battery module 5 while cooling the vehicle interior.

[0246] In addition, see the following text. Figure 5 The fourth mode is described in detail for heating the vehicle interior and operating the gas injection device.

[0247] Figure 5 This is an operational state diagram of the fourth mode of a heat pump system for a vehicle according to an embodiment of the present invention.

[0248] Reference Figure 5 In the fourth mode, the portion of the refrigerant line 11 that connects the compressor 10, the first heat exchanger 12, and the gas injection device 30 can be opened.

[0249] Furthermore, the portion of the refrigerant line 11 from the gas injection device 30 to the first end of the connecting line 21, and the portion of the refrigerant line 11 from the second end of the connecting line 21 to the compressor 10, can be opened.

[0250] In other words, the portion of the refrigerant line 11 that connects the first end of the connecting line 21 to the second end of the connecting line 21 via the first expansion valve 15 and the evaporator 16 can be closed by the first expansion valve 15.

[0251] In an embodiment of the present invention, the connecting pipeline 21 can be opened by the second expansion valve 23.

[0252] The first pipeline 33 can be opened via the fourth expansion valve 34. Furthermore, the second pipeline 35 can be closed via the fourth expansion valve 34.

[0253] In this state, the refrigerant compressed in compressor 10 can be introduced into the second heat exchanger 13 and the first heat exchanger 12 along refrigerant line 11. The first coolant line 2 can be opened, thereby supplying coolant to electrical components 3.

[0254] Therefore, the second heat exchanger 13 can condense (or cool) the refrigerant by using air introduced from the outside when the vehicle is in motion. The first heat exchanger 12 can condense (or cool) the refrigerant by using coolant supplied from the electrical component 3.

[0255] When the refrigerant passes through the second heat exchanger 13, it can recover heat from the ambient air by exchanging heat with the ambient air. In addition, when the refrigerant passes through the first heat exchanger 12, it can recover waste heat from the electrical components 3 by exchanging heat with the coolant.

[0256] In other words, the first heat exchanger 12 and the second heat exchanger 13 can recover heat from the ambient air and waste heat from the electrical components 3 through the above-described operation, and use it to increase the temperature of the refrigerant.

[0257] The refrigerant condensed (or cooled) in the first heat exchanger 12 can be introduced into the internal heat exchanger 14 along the refrigerant line 11. Thereafter, the refrigerant that has passed through the internal heat exchanger 14 can be introduced into the third expansion valve 32.

[0258] The third expansion valve 32 can expand the refrigerant introduced through the refrigerant line 11, and can supply the expanded refrigerant to the gas-liquid separator 31 through the refrigerant line 11.

[0259] The fourth expansion valve 34 allows the refrigerant introduced from the gas-liquid separator 31 through the first line 33 to flow without expansion.

[0260] Therefore, the refrigerant discharged from the gas-liquid separator 31 can be supplied to the compressor 10 through the first line 33 without expansion.

[0261] In other words, the gas-liquid separator 31 can supply gaseous refrigerant from the internally introduced refrigerant to the compressor 10 through the opened first pipeline 33.

[0262] Through this operation, the gas injection device 30 can cause the gaseous refrigerant discharged from the gas-liquid separator 31 to flow back to the compressor 10 through the first line 33, thereby increasing the flow rate of the refrigerant circulating through the refrigerant line 11.

[0263] The refrigerant discharged from the gas-liquid separator 31 through the refrigerant line 11 can be introduced into the second expansion valve 23 along the connecting line 21.

[0264] The second expansion valve 23 can expand the refrigerant introduced through the connecting line 21 and supply the expanded refrigerant to the cooler 20.

[0265] In this case, the second coolant line 4 can be opened to connect the cooler 20 and the battery module 5.

[0266] Therefore, the refrigerant introduced into the cooler 20 can cool the coolant while exchanging heat with the coolant supplied from the battery module 5 through the second coolant line 4.

[0267] The temperature of the coolant circulating along the second coolant line 4 can be increased by absorbing waste heat from the battery module 5.

[0268] In this state, coolant can be supplied to cooler 20 along the second coolant line 4. Therefore, the waste heat generated by battery module 5 can raise the temperature of the coolant supplied to cooler 20.

[0269] In other words, the cooler 20 can recover the waste heat of the battery module 5 by exchanging heat between the coolant and the refrigerant, and use it to increase the temperature of the refrigerant.

[0270] The refrigerant that has passed through the cooler 20 can be introduced into the internal heat exchanger 14 along the refrigerant line 11.

[0271] The internal heat exchanger 14 can exchange heat between the refrigerant supplied from the first heat exchanger 12 and the refrigerant supplied from the evaporator 16.

[0272] In other words, the internal heat exchanger 14 can exchange heat between the refrigerant condensed (or cooled) in the first heat exchanger 12 and the low-temperature refrigerant discharged from the evaporator 16 and the cooler 20 respectively, and can supply the heat-exchanged refrigerant to the compressor 10 and the third expansion valve 32 respectively.

[0273] Furthermore, the refrigerant from the cooler 20, having passed through the internal heat exchanger 14, can be introduced into the receiver 17 along the refrigerant line 11. Thereafter, the refrigerant can be introduced into the compressor 10 via the receiver 17.

[0274] The refrigerant compressed in the compressor 10 can be supplied to the first heat exchanger 12 via the second heat exchanger 13 through the refrigerant line 11.

[0275] The heat pump system can repeat the above process.

[0276] Although not shown in the figure, the first heat exchanger 12 in the heat pump system can be connected to a heating device for heating the interior of the vehicle via a separate coolant line (not shown).

[0277] The heating element can be installed inside the HVAC module (not shown) together with the evaporator 16.

[0278] Therefore, the refrigerant introduced into the first heat exchanger 12 can exchange heat with the coolant supplied from the heating device. The coolant, whose heat is increased by heat exchange with the refrigerant in the first heat exchanger 12, can be supplied to the heating device.

[0279] The ambient air introduced into the vehicle can be converted to a high-temperature state through heat exchange with the high-temperature coolant introduced into the heating device, and then introduced into the vehicle to achieve heating of the vehicle interior.

[0280] When the first heat exchanger 12 is not connected to a heating device, the second heat exchanger 13 in the heat pump system can be located inside the HVAC module (not shown) together with the evaporator 16.

[0281] Therefore, the ambient air introduced into the vehicle can be converted into a high-temperature state by exchanging heat with the high-temperature refrigerant introduced into the second heat exchanger 13, and then introduced into the vehicle to achieve heating of the vehicle interior.

[0282] Therefore, the refrigerant circulating in the heat pump system can successfully recover heat from the ambient air, waste heat from electrical components 3, or waste heat from battery module 5, thereby improving the overall heating performance and efficiency of the system.

[0283] Furthermore, according to the present invention, the use of a separate electric heater can be minimized while improving heating efficiency and performance.

[0284] In other words, while repeating the above operations, the heat pump system can increase the flow rate of refrigerant flowing along the refrigerant line 11 and can fully recover and utilize waste heat, thereby improving the heating performance and efficiency of the system.

[0285] In addition, the gas injection device 30 can increase the flow rate of refrigerant circulating through the refrigerant line 11, thereby maximizing the heating performance.

[0286] Therefore, as described above, by using a single cooler 20 that allows heat exchange between the coolant and refrigerant, the heat pump system for a vehicle according to an embodiment of the present invention can recover waste heat from the battery module 5 or cool the battery module 5 according to the air conditioning mode inside the vehicle, and can regulate the temperature of the battery module 5.

[0287] Furthermore, according to the present invention, by applying a gas injection device 30 that operates selectively in a selected air conditioning mode inside the vehicle to increase the flow of refrigerant, the cooling and heating performance of the system can be improved.

[0288] Furthermore, according to the present invention, when the external temperature is high or when the pressure and temperature of the refrigerant are higher than the critical pressure and temperature, the performance degradation of the cooling vehicle interior can be prevented by preventing the temperature of the refrigerant discharged from the compressor 10 from becoming too high.

[0289] Furthermore, according to the present invention, by using the gas injection device 30, the number of system components can be minimized while the system performance can be maximized, thereby achieving system simplification and streamlining.

[0290] Furthermore, according to the present invention, the power consumption of the compressor 10 can be reduced in the cooling mode inside the vehicle, and unnecessary power consumption can be reduced by improving the heating performance in the heating mode inside the vehicle, thereby increasing the overall driving distance of the vehicle.

[0291] Furthermore, according to the present invention, by streamlining the entire system, manufacturing costs and weight can be reduced, and space utilization of the vehicle and vehicle system can be improved.

[0292] Although the invention has been described in conjunction with embodiments currently considered practical, it should be understood that the invention is not limited to the disclosed embodiments. Rather, the invention is intended to cover various modifications and equivalent configurations included within the spirit and scope of the appended claims.

Claims

1. A heat pump system for a vehicle, the heat pump system comprising: A compressor, configured to compress refrigerant; A first heat exchanger is connected to the compressor via a refrigerant line; The first expansion valve is connected to the first heat exchanger via a refrigerant line; An evaporator, which is connected to the first expansion valve via a refrigerant line and to the compressor via a refrigerant line, is configured to evaporate the refrigerant; A gas injection device is disposed on the refrigerant line between the first heat exchanger and the first expansion valve. The gas injection device is configured to selectively expand the refrigerant supplied from the first heat exchanger and allow the expanded refrigerant to flow, and to selectively supply a portion of the refrigerant to the compressor to increase the flow rate of the refrigerant circulating through the refrigerant line. The flow of refrigerant is controlled by operating the gas injection device based on at least one mode for controlling the temperature inside the vehicle.

2. The heat pump system according to claim 1, further comprising: Connecting pipelines, including: The first end is connected to the refrigerant line between the first heat exchanger and the first expansion valve, and A second end is connected to a refrigerant line between the compressor and the evaporator; a cooler is disposed on the connecting line, the cooler being configured to regulate the temperature of the coolant by heat exchange between the refrigerant introduced through the connecting line and the coolant; and A second expansion valve is provided on the connecting pipeline at the upstream end of the cooler.

3. The heat pump system according to claim 2, wherein, The gas injection device includes: A gas-liquid separator is installed on the refrigerant pipeline between the first heat exchanger and the first expansion valve; The third expansion valve is located on the refrigerant line at the upstream end of the gas-liquid separator; The first pipeline has a first end connected to the gas-liquid separator and a second end connected to the compressor; A fourth expansion valve is disposed on the first pipeline; and The second pipeline has its first end connected to the fourth expansion valve and its second end connected to the refrigerant pipeline between the evaporator and the compressor.

4. The heat pump system according to claim 3, wherein, The gas-liquid separator is configured to operate when refrigerant expanded by the third expansion valve is supplied to the gas-liquid separator, and is also configured to supply gaseous refrigerant in the refrigerant to the compressor through the first line to increase the flow rate of refrigerant circulating through the refrigerant line.

5. The heat pump system according to claim 3, wherein, When the gas injection device needs to be operated, the third expansion valve is configured to expand the refrigerant supplied through the refrigerant line and to supply the refrigerant expanded by the third expansion valve to the gas-liquid separator.

6. The heat pump system according to claim 3, wherein, In at least one of the said modes, The fourth expansion valve is configured to close the portion of the first pipeline connected to the compressor, and is configured to open the second pipeline, and is configured to expand the refrigerant introduced from the gas-liquid separator through the first pipeline so that the refrigerant expanded by the fourth expansion valve flows into the second pipeline.

7. The heat pump system according to claim 3, wherein, In at least one of the said modes, The fourth expansion valve is configured to close the second line and is also configured to allow refrigerant introduced from the gas-liquid separator through the first line to flow without expansion.

8. The heat pump system according to claim 3, wherein, The at least one mode includes: A first mode for cooling the interior of a vehicle, wherein the gas injection device is configured to operate when the temperature of the refrigerant discharged from the compressor is greater than or equal to a critical temperature; A second mode for cooling the vehicle interior, in which the gas injection device is configured to operate when the temperature of the refrigerant discharged from the compressor is less than or equal to the critical temperature; A third mode for cooling the battery module while simultaneously cooling the vehicle interior, wherein in this third mode, the gas injection device is configured to operate when the temperature of the refrigerant discharged from the compressor is greater than or equal to the critical temperature; and A fourth mode for heating the interior of the vehicle, in which the gas injection device is configured to operate.

9. The heat pump system according to claim 8, wherein, In the first mode: The refrigerant line connecting the compressor, the first heat exchanger, the first expansion valve, and the evaporator is configured to be open; The connecting pipeline is configured to be closed by the second expansion valve; The portion of the first pipeline connecting the gas-liquid separator to the fourth expansion valve is configured to be opened by the fourth expansion valve. The remaining portion of the first pipeline connecting the fourth expansion valve to the compressor is configured to be closed by the fourth expansion valve; The second pipeline is configured to be opened by the fourth expansion valve; The first expansion valve is configured to expand the refrigerant introduced through the refrigerant line and to supply the refrigerant expanded by the first expansion valve to the evaporator; The third expansion valve is configured to expand the refrigerant introduced through the refrigerant line, and to supply the refrigerant expanded by the third expansion valve to the gas-liquid separator through the refrigerant line. The fourth expansion valve is configured to expand the refrigerant introduced from the gas-liquid separator through the first line, and to allow the refrigerant expanded by the fourth expansion valve to flow along the second line; and The gas-liquid separator is configured to supply gaseous refrigerant in the refrigerant to the compressor through an open portion of the first pipeline and the second pipeline.

10. The heat pump system according to claim 8, wherein, In the second mode: The refrigerant line connecting the compressor, the first heat exchanger, the first expansion valve, and the evaporator is configured to be open; The connecting pipeline is configured to be closed by the second expansion valve; The first pipeline is configured to be opened by the fourth expansion valve; The second pipeline is configured to be closed by the fourth expansion valve; The first expansion valve is configured to expand the refrigerant introduced through the refrigerant line and to supply the refrigerant expanded by the first expansion valve to the evaporator; The third expansion valve is configured to expand the refrigerant introduced through the refrigerant line, and to supply the refrigerant expanded by the third expansion valve to the gas-liquid separator through the refrigerant line. The fourth expansion valve is configured to allow refrigerant introduced from the gas-liquid separator through the first line to flow without expansion; and The gas-liquid separator is configured to supply gaseous refrigerant from the refrigerant to the compressor through an open first line.

11. The heat pump system according to claim 8, wherein, In the third mode: The refrigerant line connecting the compressor, the first heat exchanger, the first expansion valve, and the evaporator is configured to be open; The connecting pipeline is configured to be opened by the second expansion valve; The portion of the first pipeline connecting the gas-liquid separator to the fourth expansion valve is configured to be opened by the fourth expansion valve. The remaining portion of the first pipeline connecting the fourth expansion valve to the compressor is configured to be closed by the fourth expansion valve; The second pipeline is configured to be opened by the fourth expansion valve; The first expansion valve is configured to expand the refrigerant introduced through the refrigerant line and to supply the refrigerant expanded by the first expansion valve to the evaporator; The second expansion valve is configured to expand the refrigerant introduced through the connecting line, and to supply the refrigerant expanded by the second expansion valve to the cooler; The third expansion valve is configured to expand the refrigerant introduced through the refrigerant line, and to supply the refrigerant expanded by the third expansion valve to the gas-liquid separator through the refrigerant line. The fourth expansion valve is configured to expand the refrigerant introduced from the gas-liquid separator through the first pipeline, and to allow the refrigerant expanded by the fourth expansion valve to flow along the second pipeline; and The gas-liquid separator is configured to supply gaseous refrigerant in the refrigerant to the compressor through an open portion of the first pipeline and the second pipeline.

12. The heat pump system according to claim 8, wherein, In the fourth mode: The refrigerant pipeline connecting the compressor, the first heat exchanger, and the gas injection device is configured to be open. The portion of the refrigerant line connecting the gas injection device to the first end of the connecting line and the portion of the refrigerant line connecting the second end of the connecting line to the compressor are both configured to be open; The portion of the refrigerant line connecting the evaporator to the first end of the connecting line and the portion of the refrigerant line connecting the evaporator to the second end of the connecting line are both configured to be closed by the first expansion valve. The connecting pipeline is configured to be opened by the second expansion valve; The first pipeline is configured to be opened by the fourth expansion valve; The second pipeline is configured to be closed by the fourth expansion valve; The second expansion valve is configured to expand the refrigerant introduced through the connecting line, and to supply the refrigerant expanded by the second expansion valve to the cooler; The third expansion valve is configured to expand the refrigerant introduced through the refrigerant line, and to supply the refrigerant expanded by the third expansion valve to the gas-liquid separator through the refrigerant line. The fourth expansion valve is configured to allow refrigerant introduced from the gas-liquid separator through the first line to flow without expansion; and The gas-liquid separator is configured to supply gaseous refrigerant from the refrigerant to the compressor through an open first line.

13. The heat pump system according to claim 3, wherein: Both the second and third expansion valves are two-way electronic expansion valves, configured to selectively expand the refrigerant while controlling its flow; and The fourth expansion valve is a three-way electronic expansion valve configured to selectively expand the refrigerant while controlling the flow of the refrigerant.

14. The heat pump system according to claim 2, further comprising: A second heat exchanger is disposed on the refrigerant line between the compressor and the first heat exchanger; as well as A receiver is disposed on the refrigerant line between the evaporator and the compressor.

15. The heat pump system according to claim 14, wherein: Both the first heat exchanger and the cooler are water-cooled heat exchangers, configured to exchange heat between the refrigerant and the coolant; and The second heat exchanger is an air-cooled heat exchanger configured to exchange heat between the refrigerant and the air.

16. The heat pump system according to claim 1, further comprising: An internal heat exchanger is connected to a refrigerant line connecting the first heat exchanger and the first expansion valve and to a refrigerant line connecting the evaporator and the compressor. The internal heat exchanger is configured to exchange heat between refrigerant supplied from the first heat exchanger and refrigerant supplied from the evaporator.

17. The heat pump system according to claim 1, wherein: The first heat exchanger is connected to electrical components via a first coolant line that circulates the first coolant; and The cooler is connected to the battery module via a second coolant pipeline that circulates a second coolant.

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