HEAT PUMP SYSTEM FOR VEHICLES

Abstract

An embodiment of a heat pump system for a vehicle comprises a compressor (10) for compressing a refrigerant, a condenser (12) connected to the compressor (10), a heat exchanger (14) connected to the condenser (12), a first expansion valve (16) connected to the heat exchanger (14), an evaporator (18) connected to the first expansion valve (16), a first refrigerant connection line (21) whose ends are connected between the compressor (10) and the evaporator (18) and between the heat exchanger (14) and the first expansion valve (16), a heat exchanger device (24) and a second expansion valve (26) on the first refrigerant connection line (21), and a gas injection device (50) for selectively expanding and flowing the refrigerant supplied from the condenser (12) or the heat exchanger (14) and for selectively supplying a part of the refrigerant to the compressor (10),to increase a flow rate of the refrigerant, wherein the flow of the refrigerant is controlled according to a mode for controlling a temperature of a vehicle interior or a battery module (3).

Description

TECHNICAL FIELDThe present invention relates to a heat pump system for a vehicle.BACKGROUNDIn general, 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.The air conditioning unit, which is to maintain the interior of the vehicle at an appropriate temperature regardless of a change in the external temperature to maintain a comfortable interior environment, is configured to heat or cool the interior of the vehicle by heat exchange using a condenser and an evaporator while circulating a refrigerant discharged by the operation of a compressor back to the compressor through the condenser, a receiver dryer, an expansion valve, and the evaporator.That is, in a summer cooling mode, the air conditioning unit lowers a temperature and 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 dryer and the expansion valve, and then evaporating the refrigerant in the evaporator.Recently, according to a continuously increasing interest in energy efficiency and pollution problem, an eco-friendly vehicle capable of substantially replacing an internal combustion engine vehicle has been developed, and the eco-friendly vehicle is generally divided into an electric vehicle operated with a fuel cell or electricity as a power source and a hybrid vehicle operated with an internal combustion engine and a battery.In the electric vehicle or the hybrid vehicle among these eco-friendly vehicles, a separate heater is not used unlike an air conditioner of a general vehicle, and an air conditioner used in the eco-friendly vehicle is generally referred to as a heat pump system.In the case of an electric vehicle driven by a fuel cell as a power source, the driving force is generated by converting the chemical reaction energy of oxygen and hydrogen into electric energy. In this process, heat energy is generated by the chemical reaction inside the fuel cell. In order to ensure the performance of the fuel cell, the generated heat needs to be effectively dissipated.Moreover, the hybrid vehicle generates the driving force by operating a motor supplied with power from the above-described fuel cell or an electric battery together with an internal combustion engine operated with a general fuel. Therefore, the heat generated from the fuel cell or the battery and the motor should be efficiently dissipated to ensure the performance of the motor.Therefore, in the hybrid vehicle or the electric vehicle according to the related art, coolant, a heat pump system, and a battery cooling system, respectively, should be configured as separate closed circuits to prevent heat generation of the motor and the battery including a fuel cell.Therefore, a size and a weight of a cooling module disposed in front of the vehicle are increased, and the arrangement of connection pipes supplying a refrigerant or a coolant to each of the heat pump system, the coolant, and the battery cooling system in an engine room becomes complicated.In addition, since the battery cooling system that heats or cools the battery according to a vehicle state is separately provided so that the battery has optimum performance, a plurality of valves are used for connecting the respective connection pipes to each other, and noise and vibration due to frequent opening / closing operations of these valves are transmitted into the interior of the vehicle, so that ride comfort is impaired.Moreover, when heating the vehicle interior, there are disadvantages of decreasing heating power due to a lack of a heat source, increasing power consumption due to the use of electric heating, increasing power consumption of the compressor, and the like.The above information in this Background section is only for enhancement of understanding of the background of the embodiments of the invention and therefore may include information that is not prior art and is already known to those skilled in the art.BRIEF EXPLANATIONThe present invention relates to a heat pump system for a vehicle. Particular embodiments relate to a heat pump system for a vehicle capable of improving cooling and heating performance by using a gas injection device (hereinafter, briefly:The gas injection device is used to selectively operate in a selected air conditioning mode of an interior of the vehicle.Embodiments of the present disclosure provide a heat pump system for a vehicle capable of improving cooling and heating performance by employing a gas injection device selectively operated in at least one mode selected for air conditioning of a vehicle interior to increase a flow rate of a refrigerant.According to one embodiment, a heat pump system for a vehicle (for example, comprises. An automobile such as a passenger car) including: a compressor that compresses a refrigerant; a condenser that is connected to the compressor via a refrigerant line; a heat exchanger that is connected to the condenser via the refrigerant line and condenses or evaporates the supplied refrigerant; a first expansion valve that is connected to the heat exchanger via the refrigerant line; an evaporator that is connected to the first expansion valve via the refrigerant line; a first refrigerant connection line that has one end connected to the refrigerant line between the compressor and the evaporator and the other end connected to the refrigerant line between the heat exchanger and the first expansion valve; and a heat exchange device (for example. A chiller) provided on the first refrigerant connection line and controlling a temperature of a refrigerant by selective heat exchange between the refrigerant introduced into the first refrigerant connection line and the introduced refrigerant, a second expansion valve provided on the first refrigerant connection line at a front end of the one heat exchange device, and a gas injection device connected to the refrigerant line, wherein the gas injection device selectively expands and moves the refrigerant supplied from the condenser or the heat exchanger and selectively supplies a part of the supplied refrigerant to the compressor to increase a flow rate of the refrigerant circulating in the refrigerant line, wherein the flow rate of the refrigerant can be controlled according to at least one mode for controlling a temperature of a vehicle interior or a temperature of a battery module.The gas injection device may further include, for example, a first gas-liquid separator provided on the refrigerant line between the condenser and the heat exchanger and selectively separating a gaseous refrigerant and a liquid refrigerant from the refrigerant introduced therein and selectively outputting the separated gaseous refrigerant and liquid refrigerant, a third expansion valve provided on the refrigerant line between the condenser and the first gas-liquid separator, a fourth expansion valve provided on the refrigerant line between the first gas-liquid separator and the heat exchanger, a second refrigerant connection line having one end connected to the first gas-liquid separator and the other end connected to a first valve provided on the refrigerant line between the heat exchanger and the first expansion valve, a second gas-liquid separator provided on the second refrigerant connection line, a third refrigerant connection line having one end connected to the refrigerant line between the heat exchanger and the first valve and the other end connected to the second gas-liquid separator, and a fifth expansion valve provided on the third refrigerant connection line.For example, the gas injection device may further include a first pipe that selectively supplies the gaseous refrigerant discharged from the first gas-liquid separator or the second gas-liquid separator to the compressor and has one end connected to the second refrigerant connection pipe between the first gas-liquid separator and the second gas-liquid separator and the other end connected to the compressor.For example, the first gas-liquid separator may be operated when the third expansion valve expands and supplies the refrigerant while heating the interior of the vehicle, and supplies the gaseous refrigerant among the supplied refrigerants to the compressor via the first pipe to increase the flow rate of the refrigerant circulating in the refrigerant pipe.For example, the second gas-liquid separator may be operated when the fifth expansion valve expands and supplies the refrigerant while cooling the interior of the vehicle, and supplies the gaseous refrigerant among the supplied refrigerants to the compressor via the first pipe to increase the flow rate of the refrigerant circulating in the refrigerant pipe.For example, the gas injection device may further include a second pipe connected between the third expansion valve and the fourth expansion valve and selectively bypasses the refrigerant supplied from the condenser to the heat exchanger according to an operation of the third expansion valve and the fourth expansion valve without passing through the first gas-liquid separator.For example, the gas injection device may further include a second valve provided on the second refrigerant connection line between the first gas-liquid separator and the second gas-liquid separator, and a third line having one end connected to the second valve and the other end connected to the refrigerant line between the evaporator and the compressor.The at least one mode may include, for example, at least a first mode in which the gas injection device is operated and the battery module is cooled while the interior of the vehicle is cooled, a second mode in which the gas injection device is operated and the interior of the vehicle is heated, a third mode in which the gas injection device is not operated and the battery module is cooled while the interior of the vehicle is cooled, a fourth mode in which the gas injection device is not operated and the interior of the vehicle is heated, and a fifth mode in which the interior of the vehicle is heated and dehumidified.In the case of the first mode, for example, the first refrigerant connection line may be / are opened by an operation of the second expansion valve, the second refrigerant connection line may be / are opened by an operation of the first valve, the third refrigerant connection line may be / are opened by an operation of the fifth expansion valve, a portion of the refrigerant connection line connecting the third refrigerant connection line and the first valve may be / are closed by an operation of the first valve, the first line may be / are opened by an operation of the second valve, the second line may be / are opened by an operation of the third expansion valve and the fourth expansion valve, the third line may be / are closed by the operation of the second valve, the refrigerant line connecting the third expansion valve, the first gas-liquid separator, and the fourth expansion valve, When the third expansion valve and the fourth expansion valve are / are operated to be closed, the first expansion valve may expand the refrigerant introduced from the second gas-liquid separator along the refrigerant line and supply the expanded refrigerant to the evaporator, the second expansion valve may expand the refrigerant introduced into the first refrigerant connection line and supply the expanded refrigerant to the heat exchange device, the third expansion valve may flow the refrigerant supplied from the condenser into the second line without expanding the refrigerant, the fourth expansion valve may flow the refrigerant supplied through the second line into the heat exchanger without expanding the refrigerant, the fifth expansion valve may expand the refrigerant supplied from the heat exchanger through the third refrigerant connection line and supply the expanded refrigerant to the second gas-liquid separator, and the second gas-liquid separator may supply the gaseous refrigerant among the refrigerants supplied through the third refrigerant connection line to the compressor through the opened second refrigerant connection line and the first line, and discharge the liquid refrigerant into the refrigerant line through the first valve.In the case of the second mode, the first refrigerant connection line may be / are closed by an operation of the second expansion valve, the second refrigerant connection line may have opened a portion connecting the first gas-liquid separator and the first line, and a portion connecting the second gas-liquid separator and the third line, the third refrigerant connection line may be / are opened by an operation of the fifth expansion valve, the refrigerant line connecting the evaporator from a rear end and downstream of the heat exchanger with respect to the third refrigerant connection line may be / are closed, the first line may be / are opened, the second line may be / are closed by the operation of the third expansion valve and the fourth expansion valve, the third line may be / are opened by an operation of the second valve, In the case where the refrigerant line connecting the third expansion valve, the first gas-liquid separator, and the fourth expansion valve may be / are opened by the operation of the third expansion valve and the fourth expansion valve, may be / become an operation of the first expansion valve and the second expansion valve, the third expansion valve may expand the refrigerant supplied from the condenser and supply the expanded refrigerant to the first gas-liquid separator, the fourth expansion valve may expand the refrigerant supplied from the first gas-liquid separator and supply the expanded refrigerant to the heat exchanger, the fifth expansion valve may supply the refrigerant introduced from the heat exchanger via the third refrigerant connection line to the second gas-liquid separator without expanding the refrigerant, The first gas-liquid separator may supply the gaseous refrigerant among the supplied refrigerants to the compressor via the opened first line, and the second gas-liquid separator may supply the gaseous refrigerant among the refrigerants supplied via the third refrigerant connection line to the compressor via the opened third line.In the case of the third mode, the first refrigerant communication line may be / are opened by an operation of the second expansion valve, the second refrigerant communication line may be / are closed by the operation of the first valve, the third refrigerant communication line may be / are closed by an operation of the fifth expansion valve, the first line may be / are closed, the second line may be / are opened by an operation of the third expansion valve and the fourth expansion valve, the third line may be / are closed by the operation of the second valve, the refrigerant line connecting the third expansion valve, the first gas-liquid separator, and the fourth expansion valve may be / are closed by the operation of the third expansion valve and the fourth expansion valve, In the first expansion valve, the first expansion valve may expand the refrigerant introduced from the heat exchanger along the refrigerant line and supply the expanded refrigerant to the evaporator, the second expansion valve may expand the refrigerant introduced into the first refrigerant connection line and supply the expanded refrigerant to the heat exchange device, the third expansion valve may flow the refrigerant supplied from the condenser into the second line without expanding the refrigerant, the fourth expansion valve may flow the refrigerant supplied through the second line into the heat exchanger without expanding the refrigerant, and the operation of the fifth expansion valve may be / may be stopped.In the case of the fourth mode, the first refrigerant connection line may be / are closed by an operation of the second expansion valve, a portion of the second refrigerant connection line connecting the second gas-liquid separator and the third line may be / are opened by an operation of the second valve, the third refrigerant connection line may be / are opened by an operation of the fifth expansion valve, the refrigerant line connecting the evaporator to the third refrigerant connection line from a rear end of the heat exchanger may be / are closed, the first line may be / are closed, the second line may be / are opened by the operation of the third expansion valve and the fourth expansion valve, the third line may be / are opened by an operation of the second valve, the refrigerant line connecting the third expansion valve may be, The first gas-liquid separator and the fourth expansion valve may be / are closed by the operation of the third expansion valve and the fourth expansion valve, an operation of the first expansion valve and the second expansion valve may be stopped, the third expansion valve may flow the refrigerant supplied from the condenser into the second line without expanding the refrigerant, the fourth expansion valve may expand the refrigerant supplied through the second line and flow the expanded refrigerant into the heat exchanger, the fifth expansion valve may supply the refrigerant introduced into the third refrigerant connection line to the second gas-liquid separator without expanding the refrigerant, and the second gas-liquid separator may supply the gaseous refrigerant among the refrigerants supplied through the third refrigerant connection line to the compressor through the opened third line.In the case of the fifth mode, the first refrigerant connection line may be / are closed by an operation of the second expansion valve, a portion of the second refrigerant connection line connecting the second gas-liquid separator and the third line may be / are opened by an operation of the second valve, the third refrigerant connection line may be / are opened by an operation of the fifth expansion valve, the refrigerant line connecting the evaporator from a rear end of the heat exchanger to the third refrigerant connection line may be / are opened by an operation of the first valve and the first expansion valve, the first line may be / are closed, the second line may be / are opened by the operation of the third expansion valve and the fourth expansion valve, the third line may be / are opened by an operation of the second valve, In the case where the refrigerant line connecting the third expansion valve and the first gas-liquid separator may be / are closed by an operation of the third expansion valve and the fourth expansion valve, the first expansion valve may selectively expand the refrigerant supplied from the heat exchanger and supply the expanded refrigerant to the evaporator, may stop an operation of the second expansion valve, the third expansion valve may flow the refrigerant supplied from the condenser into the second line without expanding the refrigerant, the fourth expansion valve may expand the refrigerant supplied via the second line and flow the expanded refrigerant into the heat exchanger, the fifth expansion valve may supply the refrigerant introduced into the third refrigerant connection line to the second gas-liquid separator without expanding the refrigerant, and the second gas-liquid separator may supply the gaseous refrigerant among the refrigerants supplied via the third refrigerant connection line to the compressor via the opened third line.For example, the heat exchanger may condense the supplied refrigerant in the first mode and the third mode.For example, the heat exchanger may evaporate the supplied refrigerant in the second mode, the fourth mode, and the fifth mode.For example, the first expansion valve, the second expansion valve, and the fifth expansion valve may each be a 2-way expansion valve that is selectively operated in the at least one mode and selectively expands the refrigerant while controlling the flow of the supplied refrigerant.For example, the third expansion valve and the fourth expansion valve may each be a 3-way electronic expansion valve that is selectively operated in the at least one mode and selectively expands the refrigerant while controlling the flow of the refrigerant.The one heat exchanger device may be connected to the battery module via a coolant line through which the coolant circulates, for example.The coolant line can be / are opened, for example, in order to connect the heat exchanger device and the battery module during cooling of the battery module.As described above, according to a heat pump system for a vehicle according to an embodiment of the present invention, it is possible to improve cooling and heating performance by employing a gas injection device that selectively operates in at least one mode selected for air conditioning of a vehicle interior to increase a flow rate of a refrigerant.Moreover, according to embodiments of the present invention, it is possible to simplify the system by maximizing the system performance using a gas injection device while minimizing the component (number).Moreover, according to an exemplary embodiment of the present invention, it is possible to reduce manufacturing cost, reduce weight, and improve space utilization by simplifying the entire system.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a block diagram of a heat pump system for a vehicle according to an embodiment. FIG. 2 is an operation state diagram according to a first mode in the heat pump system for a vehicle according to an embodiment of the present invention. FIG. 3 is an operation state diagram according to a second mode in the heat pump system for a vehicle according to an embodiment of the present invention. FIG. 4 is an operation state diagram according to a third mode in the heat pump system for a vehicle according to an embodiment of the present invention. FIG. 5 is an operation state diagram according to a fourth mode in the heat pump system for a vehicle according to an embodiment of the present invention. FIG. 6 is an operation state diagram according to a fifth mode in the heat pump system for a vehicle according to an embodiment of the present invention.DETAILED DESCRIPTION OF EMBODIMENTSExemplary embodiments will be described in detail below with reference to the accompanying drawings.Since exemplary embodiments indicated in the present specification and embodiments shown in the accompanying drawings are only exemplary embodiments of the present invention, they do not represent the entire spirit of the embodiments of the present invention. It is understood that various alterations and modifications may replace the exemplary embodiments given in the present specification and the embodiments configured in the accompanying drawings at a time when the application is filed.The description of contents unrelated to the embodiments of the present invention is omitted to clearly describe the embodiments of the present invention, and like reference numerals denote like elements throughout the description.Since sizes and thicknesses of the respective components are arbitrarily set forth in the accompanying drawings for convenience of explanation, the embodiments of the present invention are not limited to the contents shown in the accompanying drawings. Moreover, the thicknesses have been exaggerated to clearly show a plurality of parts and regions.Moreover, throughout the specification, unless expressly described otherwise, the term "comprising" and variations such as "comprising" "comprising", etc. are understood to imply the inclusion of stated elements but not the exclusion of other elements.Moreover, the terms "..unit", "... means", "... part", "..element" described in the specification denote units of a comprehensive configuration for executing at least a function and an operation.FIG. 1 is a block diagram of a heat pump system for a vehicle according to an exemplary embodiment.A heat pump system for a vehicle according to an embodiment of the present invention may improve cooling and heating performance by employing a gas injection device 50 selectively operated in at least one mode selected for air conditioning an interior of a vehicle.Here, the heat pump system may be connected to a cooling device that circulates coolant in an electric vehicle and an air conditioning device that is an air conditioning device for cooling and heating the interior space.That is, referring to FIG. 1, the heat pump system may include the air conditioning device including the cooling device, a compressor 10, a condenser 12, a heat exchanger 14, a first expansion valve 16, an evaporator 18, a first refrigerant connection line 21, a heat exchanger device 24, a second expansion valve 26, and the gas injection device 50.The cooling device may include electrical components (not shown) through which the coolant circulates, and a battery module 3.This cooling device may further comprise a cooler (for example. These may include front coolers; not shown). The radiator is disposed in the front portion of the vehicle. Behind the radiator, a cooling fan (not shown) is disposed. Accordingly, the radiator can cool the coolant by operating, for example, a cooling fan and exchanging heat with outside air.Here, the electrical component may be connected to the heat exchanger 14 or a line through which coolant circulates to the heat exchanger device 24, and the battery module 3 may be connected to the heat exchanger device 24 and a coolant line 5 through which coolant circulates.Here, when cooling the battery module 3 or recovering the waste heat of the battery module 3 when heating the vehicle interior, the coolant line 5 may be opened to connect the heat exchange device 24 and the battery module 3.In this case, the coolant in the coolant line 5 may be selectively circulated by the operation of a water pump (not shown).The electrical component may include an electric power control unit (EPCU), a motor, an inverter, an on board charger (OBC), an autonomous driving control device, or the like.The electric power control unit, the inverter, the motor, or the autonomous driving control device may generate heat during driving, and the on-board charging device may generate heat when charging the battery module 3.That is, when the waste heat generated from the electric component is recovered during heating of the vehicle interior, the heat generated from the electric power control unit, the motor, the inverter, the on-board charger, or the autonomous driving control device may be recovered.In the present embodiment, the compressor 10 may compress the supplied refrigerant.The condenser 12 is connected to the compressor 10 via a refrigerant line 11. Here, the condenser 12 and the evaporator 18 may be incorporated in an HVAC module (Engl. HVAC: heating, ventilation and air conditioning) (not shown), for example.Moreover, the interior of the HVAC module may include an open-close door that controls the air flowing through the evaporator 18 (e.g., flowing into the vehicle interior) to be selectively introduced into the condenser 12 when the interior of the vehicle is cooled or heated.That is, when the interior of the vehicle is heated, the opening-closing door is opened to allow outside air flowing through the evaporator 18 to be introduced into the condenser 12.On the other hand, when cooling the vehicle interior, the condenser 12 side is closed by opening / closing the opening-closing door, so that the outside air cooled by flowing through the evaporator 18 is directly introduced into the vehicle interior.In the present embodiment, the heat exchanger 14 may be connected to the condenser 12 via the refrigerant line 11. This heat exchanger 14 can perform heat exchange of the refrigerant supplied from the condenser 12 with air or refrigerant to condense or evaporate the refrigerant.That is, the heat exchanger 14 may be configured as, for example, an air-cooled heat exchanger that is disposed behind the radiator at a front of the vehicle and exchanges heat between air and refrigerant. On the other hand, the heat exchanger 14 may be configured as, for example, a water-cooled heat exchanger connected to a separate line through which coolant (for example, another cooling system) in the vehicle circulates to exchange heat between the coolant and a refrigerant.The first expansion valve 16 may be provided in the refrigerant line 11 between the heat exchanger 14 and the evaporator 18.The evaporator 18 is connected to the heat exchanger 14 via the refrigerant line 11. When the refrigerant expanded by the first expansion valve 16 is introduced, the evaporator 18 may evaporate the refrigerant by heat exchange with the air introduced into the HVAC module.In the present embodiment, one end of the first refrigerant connection line 21 may be connected to the refrigerant line 11 between the compressor 10 and the evaporator 18. The other end of the first refrigerant connection line 21 may be connected to the refrigerant line 11 between the heat exchanger 14 and the first expansion valve 16.The heat exchanger device 24 is provided in the first refrigerant connection line 21. The heat exchange device 24 may selectively circulate coolant internally through the coolant line 5.That is, the heat exchange device 24 may be, for example, the water-cooled heat exchanger into which the coolant is introduced.Accordingly, the heat exchange device 24 can control the temperature of the coolant by heat exchange between the coolant introduced into the first refrigerant connection line 21 and the coolant selectively introduced via the coolant line 5.In the present embodiment, the second expansion valve 26 may be provided on the first refrigerant connection line 21 at the front end of the heat exchange device 24.This second expansion valve 26 can expand the refrigerant introduced through the first refrigerant connection line 21 in cooling the battery module 3 using the refrigerant that has heat-exchanged with the refrigerant during cooling of the vehicle interior, and introduce the expanded refrigerant into the heat exchange device 24.That is, when the battery module 3 is cooled during cooling of the vehicle interior, the second expansion valve 26 may expand the refrigerant introduced into the first refrigerant connection line 21 and introduce the expanded refrigerant into the heat exchange device 24 while lowering the temperature of the expanded refrigerant, thereby further lowering the water temperature of the refrigerant flowing through the interior of the heat exchange device 24.Accordingly, the coolant whose water temperature is lowered while passing through the heat exchange device 24 is introduced into the battery module 3, and thus the battery module 3 can be cooled more efficiently.The gas injection device 50 may be connected to the refrigerant line 11. The gas injection device 50 may selectively expand and flow the refrigerant supplied from the condenser 12 or the heat exchanger 14, and may selectively supply a part of the supplied refrigerant to the compressor 10 to increase a total flow rate of the refrigerant circulating in the refrigerant line 11.Here, the gas injection device 50 may include a first gas-liquid separator 51, a third expansion valve 52, a fourth expansion valve 53, a second refrigerant connection line 54, a second gas-liquid separator 55, a third refrigerant connection line 56, and a fifth expansion valve 57.The first gas-liquid separator 51 may be provided in the refrigerant line 11 between the condenser 12 and the heat exchanger 14. The first gas-liquid separator 51 may separate a gaseous refrigerant and a liquid refrigerant among the refrigerants introduced therein, and selectively discharge the gaseous refrigerant and the liquid refrigerant.In the present embodiment, the third expansion valve 52 may be provided in the refrigerant line 11 between the condenser 12 and the first gas-liquid separator 51.The fourth expansion valve 53 may be provided in the refrigerant line 11 between the first gas-liquid separator 51 and the heat exchanger 14.One end of the second refrigerant connection line 54 may be connected to the first gas-liquid separator 51. The other end of the second refrigerant connection line 54 may be connected to a first valve V 1 provided in the refrigerant line 11 between the heat exchanger 14 and the first expansion valve 16.In the present embodiment, the second gas-liquid separator 55 may be provided in the second refrigerant connection line 54. The second gas-liquid separator 55 may separate a gaseous refrigerant and a liquid refrigerant among the refrigerants introduced therein, and selectively discharge the gaseous refrigerant and the liquid refrigerant.One end of the third refrigerant connection line 56 may be connected to the refrigerant line 11 between the heat exchanger 14 and the first valve V 1. The other end of the third refrigerant connection line 56 may be connected to the second gas-liquid separator 55.The fifth expansion valve 57 may be provided in the third refrigerant connection line 56.The gas injection device 50 configured as described above may further include a first passage 61, a second passage 62, a second valve V 2, and a third passage 63.One end of the first pipe 61 may be connected to the second refrigerant connection pipe 54 between the first gas-liquid separator 51 and the second gas-liquid separator 55. The other end of the first conduit 61 may be connected to the compressor 10.The first pipe 61 configured as above can selectively supply the gaseous refrigerant discharged from the first gas-liquid separator 51 or the second gas-liquid separator 55 to the compressor 10.That is, the first gas-liquid separator 51 can be operated when the third expansion valve 52 expands and supplies the refrigerant while heating the interior of the vehicle.In this case, the first gas-liquid separator 51 may supply the gaseous refrigerant among the supplied refrigerants to the compressor 10 via the first pipe 61 to increase the flow rate of the refrigerant circulating in the refrigerant pipe 11.Further, the second gas-liquid separator 55 may be operated when the fifth expansion valve 57 expands and supplies the refrigerant while cooling the interior of the vehicle.In this case, the second gas-liquid separator 55 may supply the gaseous refrigerant among the supplied refrigerants to the compressor 10 via the first pipe 61 to increase the flow rate of the refrigerant circulating in the refrigerant pipe 11.In the present embodiment, the second line 62 may connect the third expansion valve 52 and the fourth expansion valve 53.The second conduit 62 can selectively redirect the refrigerant supplied from the condenser 12 to the heat exchanger 14 according to the operation of the third expansion valve 52 and the fourth expansion valve 53 without passing through the first gas-liquid separator 51.The second valve V 2 may be provided in the second refrigerant communication line 54 between the first gas-liquid separator 51 and the second gas-liquid separator 55.Here, the first valve V 1 and the second valve V 2 may each be a 3-way valve that can distribute the flow rate and simultaneously control the refrigerant flow.One end of the third line 63 may be connected to the second valve V 2. The other end of the third pipe 63 may be connected to the refrigerant pipe 11 between the evaporator 18 and the compressor 10.The heat pump system configured as above may control the flow of the refrigerant according to at least one of a vehicle interior temperature adjustment mode and the temperature of the battery module.Here, the first expansion valve 16, the second expansion valve 26, and the fifth expansion valve 57 can be selectively operated in the at least one mode.That is, the first expansion valve 16, the second expansion valve 26, and the fifth expansion valve 57 are 2-way expansion valves that selectively expand the refrigerant while controlling the flow of the supplied refrigerant.The third expansion valve 52 and the fourth expansion valve 53 can be selectively operated in at least one mode. That is, the third expansion valve 52 and the fourth expansion valve 53 may be 3-way electronic expansion valves that selectively expand the refrigerant while controlling the flow of the refrigerant.Here, the at least one mode may include first to fifth modes.In the first mode, the gas injection device 50 may be operated and the battery module 3 may be cooled while cooling the interior of the vehicle.In the second mode, the gas injection device 50 may be operated and the interior of the vehicle may be heated.In the third mode, the gas injection device 50 may not operate, and the battery module 3 may be cooled while cooling the interior of the vehicle.In the present embodiment, in the fourth mode, the gas injection device 50 cannot be operated and the interior of the vehicle can be heated.In the fifth mode, the interior of the vehicle may be heated and dehumidified.Here, the heat exchanger 14 may condense the supplied refrigerant in the first mode and the third mode.On the other hand, the heat exchanger 14 may evaporate the supplied refrigerant in the second mode, the fourth mode, and the fifth mode.The operation and operation of the individual modes of the heat pump system according to the embodiments of the present invention configured as described above will be described in detail with reference to FIGS. 2 to 6.First, in the heat pump system according to an embodiment of the present invention, the operation according to the first mode in which the gas injection device 50 is operated and the battery module 3 is cooled while the interior of the vehicle is cooled will be described with reference to FIG. 2.FIG. 2 is an operation state diagram according to a first mode in the heat pump system for a vehicle according to an embodiment of the present invention.Referring to FIG. 2, in the case of the first mode, the compressor 10 is operated to flow the refrigerant along the refrigerant line 11 to cool the interior of the vehicle.At this time, the first refrigerant communication line 21 is opened by the operation of the second expansion valve 26. The second refrigerant communication line 54 may be opened by the operation of the first valve V 1.The third refrigerant communication line 56 is opened by the operation of the fifth expansion valve 57. At this time, a portion of the refrigerant line 11 connecting the third refrigerant connection line 56 and the first valve V 1 may be closed by the operation of the first valve V 1.That is, the refrigerant line 11 connecting the third refrigerant connection line 56 and the first valve V 1 from a rear end and downstream of the heat exchanger 14 with respect to the third refrigerant connection line 56 is closed by the operation of the first valve V 1.Here, the leading end of the heat exchanger 14 and the trailing end of the heat exchanger 14 may be set depending on the flow direction of the refrigerant.That is, based on the direction in which the refrigerant flows along the refrigerant line 11, the position at which the refrigerant is introduced into the heat exchanger 14 may be defined as the leading end of the heat exchanger 14, and the position at which the refrigerant is discharged from the heat exchanger 14 may be defined as the trailing end of the heat exchanger 14.In the present embodiment, the first passage 61 is opened by the operation of the second valve V 2. The second line 62 may be opened by the operation of the third expansion valve 52 and the fourth expansion valve 53.The third line 63 is closed by the operation of the second valve V 2.In this case, the refrigerant line 11 connecting the third expansion valve 52, the first gas-liquid separator 51, and the fourth expansion valve 53 may be closed by the operation of the third expansion valve 52 and the fourth expansion valve 53.Then, the refrigerant supplied from the compressor 10 to the condenser 12 is introduced into the third expansion valve 52 along the refrigerant line 11.The third expansion valve 52 can flow the refrigerant supplied from the condenser 12 into the second pipe 62 without expanding the refrigerant.The fourth expansion valve 53 flows the refrigerant supplied through the second pipe 62 into the heat exchanger 14 without expanding the refrigerant.The heat exchanger 14 condenses the introduced refrigerant by heat exchange with a working fluid such as air or refrigerant. The refrigerant discharged from the heat exchanger 14 is introduced into the third refrigerant connection line 56.In this case, the fifth expansion valve 57 may expand the refrigerant introduced from the heat exchanger 14 through the third refrigerant connection line 56, and supply the expanded refrigerant to the second gas-liquid separator 55.Here, the second gas-liquid separator 55 may supply the gaseous refrigerant among the refrigerants supplied via the third refrigerant connection line 56 to the compressor 10 via the opened second refrigerant connection line 54 and the first line 61.That is, the gas injection device 50 may introduce the gaseous refrigerant separated upon passing through the second gas-liquid separator 55 back into the compressor 10 through the first pipe 61, thereby increasing the flow rate of the refrigerant circulating in the refrigerant pipe 11.The second gas-liquid separator 55 may discharge the liquid refrigerant to the connected refrigerant line 11 among the refrigerants supplied via the third refrigerant connection line 56 via the second refrigerant connection line 54 and the first valve V 1.A part of the refrigerants discharged into the refrigerant line 11 may be introduced into the opened first refrigerant connection line 21, and the rest of the refrigerants may be introduced into the first expansion valve 16.Here, the second expansion valve 26 may expand the refrigerant introduced into the first refrigerant connection line 21 and supply the expanded refrigerant to the heat exchange device 24.The refrigerant introduced into the heat exchange device 24 can cool the coolant by heat exchange with the coolant supplied from the battery module 3 through the coolant line 5.The coolant cooled in the heat exchange device 24 is supplied to the battery module 3 via the coolant line 5. Accordingly, the battery module 3 can be efficiently cooled by the coolant cooled in the heat exchange device 24.That is, the coolant circulating through the coolant line 5 can efficiently cool the battery module 3 while repeatedly performing the above-described operation.Meanwhile, the first expansion valve 16 may expand the refrigerant introduced through the refrigerant line 11 and supply the expanded refrigerant to the evaporator 15.Here, the outside air introduced into the HVAC module is cooled by the refrigerant introduced into the evaporator 18 being in a low temperature state while passing through the evaporator 18.In this case, the opening-closing door of the HVAC module closes a portion passing through the condenser 12, so that the cooled outside air does not pass through the condenser 12. Therefore, the cooled outside air can be directly introduced into the interior of the vehicle, thereby cooling the interior of the vehicle.The refrigerant that has passed through the evaporator 18 or the heat exchange device 24 may be introduced into the compressor 10 together with the refrigerant that moves along the first line 61.That is, the refrigerant that has passed through the evaporator 18 and the heat exchange device 24, respectively, and the refrigerant supplied from the second gas-liquid separator 55 through the first pipe 61 are introduced into the compressor 10. The introduced refrigerant may be compressed by the operation of the compressor 10.The refrigerant compressed in the compressor 10 passes through the condenser 12 and is then supplied to the third expansion valve 52 via the refrigerant line 11.Then, the heat pump system may repeat the above-described operation.That is, the heat pump system may increase the flow rate of the refrigerant moving along the refrigerant line 11 while repeatedly performing the above-described operation.Moreover, the heat pump system can improve overall cooling performance and efficiency, and can efficiently cool the interior of the vehicle by increasing the flow rate of the refrigerant flowing along the refrigerant line 11.At the same time, the heat pump system can efficiently cool the battery module 3 using the low-temperature coolant cooled in the heat exchange device 24.In the present embodiment, the operation according to the second mode in which the gas injection device 50 is operated and the interior of the vehicle is heated will be described with reference to FIG. 3.FIG. 3 is an operation state diagram according to the second mode in the heat pump system for a vehicle according to an embodiment of the present invention.Referring to FIG. 3, in the case of the second mode, the compressor 10 is operated to flow the refrigerant along the refrigerant line 11 to heat the interior of the vehicle.Here, the first refrigerant communication line 21 is closed by the operation of the second expansion valve 26.In the second refrigerant connection line 54, a portion connecting the first gas-liquid separator 51 and the first line 61 and a portion connecting the second gas-liquid separator 55 and the third line 63 may be opened.The third refrigerant communication line 56 is opened by the operation of the fifth expansion valve 57.Here, the refrigerant line 11 connecting the evaporator 18 to the third refrigerant connection line 56 from the rear end of the heat exchanger 14 may be closed by the operation of the first valve V 1.Moreover, a portion of the second refrigerant connection line 54 connecting the second gas-liquid separator 55 and the first valve V 1 may be closed by the operation of the first valve V 1.Here, the front end of the heat exchanger 14 and the rear end of the heat exchanger 14 may be set depending on the flow direction of the refrigerant.That is, based on the direction in which the refrigerant flows along the refrigerant line 11, the position at which the refrigerant is introduced into the heat exchanger 14 may be defined as the leading end of the heat exchanger 14, and the position at which the refrigerant is discharged from the heat exchanger 14 may be defined as the trailing end of the heat exchanger 14.The first line 61 may be opened. The second passage 62 may be closed by the operation of the third expansion valve 52 and the fourth expansion valve 53.In this case, the refrigerant line 11 connecting the third expansion valve 52, the first gas-liquid separator 51, and the fourth expansion valve 53 may be opened by the operation of the third expansion valve 52 and the fourth expansion valve 53.Here, a part of the second refrigerant connection line 54 connecting the first gas-liquid separator 51 and the first line 61 may be opened.The third line 63 may be opened by the operation of the second valve V 2.In this case, a portion of the second refrigerant connection line 54 connecting the second valve V 2 and the first line 61 may be closed with respect to the first line 61.Then, the refrigerant supplied from the compressor 10 to the condenser 12 is introduced into the third expansion valve 52 along the refrigerant line 11.The third expansion valve 52 may expand the refrigerant supplied from the condenser 12 and supply the expanded refrigerant to the first gas-liquid separator 51.The first gas-liquid separator 51 can supply the gaseous refrigerant among the supplied refrigerants to the compressor 10 through the opened first pipe 61.That is, the gas injection device 50 can introduce the gaseous refrigerant separated upon passing through the first gas-liquid separator 51 back into the compressor 10 through the first pipe 61, thereby increasing the flow rate of the refrigerant circulating in the refrigerant pipe 11.The first gas-liquid separator 51 supplies the liquid refrigerant among the refrigerants supplied from the third expansion valve 52 to the fourth expansion valve 53 via the refrigerant line 11.The fourth expansion valve 53 can expand the refrigerant supplied from the first gas-liquid separator 51 and supply the expanded refrigerant to the heat exchanger 14.The heat exchanger 14 evaporates the introduced refrigerant by heat exchange with a working fluid such as air or refrigerant. The refrigerant discharged from the heat exchanger 14 is introduced into the third refrigerant connection line 56.In this case, the fifth expansion valve 57 can supply the refrigerant to the second gas-liquid separator 55 without expanding the refrigerant introduced from the heat exchanger 14 through the third refrigerant connection line 56.In this case, the second gas-liquid separator 55 may supply the gaseous refrigerant among the refrigerants supplied via the third refrigerant connection line 56 to the compressor 10 via the opened second refrigerant connection line 54 and the opened third line 63.The operations of the first expansion valve 16 and the second expansion valve 26 may be stopped.That is, the refrigerant discharged from the first gas-liquid separator 51 and the refrigerant discharged from the second gas-liquid separator 55 may be introduced into the compressor 10 together. The introduced refrigerant may be compressed by the operation of the compressor 10.The refrigerant compressed in the compressor 10 is supplied to the condenser 12 via the refrigerant line 11. At this time, the refrigerant supplied to the condenser 12 may increase the temperature of the outside air introduced into the HVAC module.The open-close door is opened to allow the outside air introduced into the HVAC module and directed through the evaporator 18 to flow through the condenser 12.Therefore, the outside air introduced from the outside is introduced in a state of room temperature in which it is not cooled at the time of passing through the evaporator 18 to which the refrigerant is not supplied. The introduced outside air is brought into a high temperature state as it passes through the condenser 12 and then introduced into the interior of the vehicle, so that heating of the interior of the vehicle can be performed.In this way, the heat pump system according to an embodiment of the present invention can improve overall heating performance and efficiency because the gas injection device 50 is operated together.Moreover, embodiments of the present invention may improve heating efficiency and performance while minimizing the use of a separate electric heater.Moreover, the gas injection device 50 can increase the flow rate of the refrigerant circulating in the refrigerant line 11, thereby maximizing the heating performance.In the present embodiment, the operation according to the third mode in which the gas injection device 50 is not operated and the battery module 3 is cooled while the interior of the vehicle is cooled will be described with reference to FIG. 4.FIG. 4 is an operation state diagram according to a third mode in the heat pump system for a vehicle according to an embodiment of the present invention.Referring to FIG. 4, in the case of the third mode, the compressor 10 is operated to flow refrigerant along the refrigerant line 11 to cool the interior of the vehicle.Here, the first refrigerant communication line 21 is opened by the operation of the second expansion valve 26. The second refrigerant communication line 54 may be closed by the operation of the first valve V 1.The third refrigerant communication line 56 is closed by the operation of the fifth expansion valve 57. Here, the operation of the fifth expansion valve 57 may be stopped.In the present embodiment, the first pipe 61 is closed. The second passage may be opened by the operation of the third expansion valve 52 and the fourth expansion valve 53.The third line 63 is closed by the operation of the second valve V 2.In this case, the refrigerant line 11 connecting the third expansion valve 52, the first gas-liquid separator 51, and the fourth expansion valve 53 may be closed by the operation of the third expansion valve 52 and the fourth expansion valve 53.Then, the refrigerant supplied from the compressor 10 to the condenser 12 is introduced into the third expansion valve 52 along the refrigerant line 11.The third expansion valve 52 can flow the refrigerant supplied from the condenser 12 into the second pipe 62 without expanding the refrigerant.The fourth expansion valve 53 flows the refrigerant supplied through the second pipe 62 into the heat exchanger 14 without expanding the refrigerant.The heat exchanger 14 condenses the introduced refrigerant by heat exchange with a working fluid such as air or refrigerant. The refrigerant discharged from the heat exchanger 14 flows through the refrigerant line 11.A part of the refrigerant discharged from the heat exchanger 14 may be introduced into the opened first refrigerant connection line 21, and the rest of the refrigerant may be introduced into the first expansion valve 16.Here, the second expansion valve 26 may expand the refrigerant introduced into the first refrigerant connection line 21 and supply the expanded refrigerant to the heat exchange device 24.The refrigerant introduced into the heat exchange device 24 can cool the coolant by heat exchange with the coolant supplied from the battery module 3 via the coolant line 5.The coolant cooled in the heat exchange device 24 is supplied to the battery module 3 via the coolant line 5. Accordingly, the battery module 3 can be efficiently cooled by the cooling mediums cooled in the heat exchange device 24.That is, the coolant circulating through the coolant line 5 can efficiently cool the battery module 3 while repeatedly performing the above-described operation.Meanwhile, the first expansion valve 16 may expand the refrigerant introduced from the heat exchanger 14 through the refrigerant line 11 and supply the expanded refrigerant to the evaporator 15.Here, the outside air introduced into the HVAC module is cooled by the refrigerant introduced into the evaporator 18 being in a low temperature state while passing through the evaporator 18.In this case, the opening-closing door of the HVAC module closes a portion passing through the condenser 12, so that the cooled outside air does not pass through the condenser 12. Therefore, the cooled outside air can be directly introduced into the interior of the vehicle, thereby cooling the interior of the vehicle.Meanwhile, the refrigerant that has passed through the evaporator 18 and the heat exchange device 24, respectively, may be introduced into the compressor 10.That is, the refrigerant that has passed through the evaporator 18 or the heat exchange device 24 may be introduced into the compressor 10. The introduced refrigerant may be compressed by the operation of the compressor 10.The refrigerant compressed in the compressor 10 flows through the condenser 12 and is then supplied to the third expansion valve 52 via the refrigerant line 11.Then, the heat pump system may repeat the above-described operation.That is, the heat pump system may cool the interior of the vehicle without operating the gas injection device 50 while repeatedly performing the above-described operation.At the same time, the heat pump system can efficiently cool the battery module 3 using the low-temperature coolant cooled in the heat exchange device 24.In the present embodiment, the operation according to the fourth mode in which the gas injection device 50 is not operated and the interior of the vehicle is heated will be described with reference to FIG. 5.FIG. 5 is an operation state diagram according to a fourth mode in the heat pump system for a vehicle according to an embodiment of the present invention.Referring to FIG. 5, in the case of the fourth mode, the compressor 10 is operated to flow the refrigerant along the refrigerant line 11 to heat the interior of the vehicle.Here, the first refrigerant communication line 21 is closed by the operation of the second expansion valve 26.A portion of the second refrigerant connection line 54 connecting the second gas-liquid separator 55 and the third line 63 may be opened by operation of the second valve V 2.The third refrigerant communication line 56 is opened by the operation of the fifth expansion valve 57.Here, the refrigerant line 11 connecting the evaporator 18 to the third refrigerant connection line 56 from the rear end of the heat exchanger 14 may be closed by the operation of the first valve V 1.Moreover, a portion of the second refrigerant connection line 54 connecting the second gas-liquid separator 55 and the first valve V 1 may be closed by the operation of the first valve V 1.Here, the front end of the heat exchanger 14 and the rear end of the heat exchanger 14 may be set depending on the flow direction of the refrigerant.That is, based on the direction in which the refrigerant flows along the refrigerant line 11, the position at which the refrigerant is introduced into the heat exchanger 14 may be defined as the leading end of the heat exchanger 14, and the position at which the refrigerant is discharged from the heat exchanger 14 may be defined as the trailing end of the heat exchanger 14.In the present embodiment, the first pipe 61 is closed. The second line 62 may be opened by the operation of the third expansion valve 52 and the fourth expansion valve 53.The third line 63 may be opened by the operation of the second valve V 2.In this case, the refrigerant line 11 connecting the third expansion valve 52, the first gas-liquid separator 51, and the fourth expansion valve 53 may be closed by the operation of the third expansion valve 52 and the fourth expansion valve 53.Then, the refrigerant supplied from the compressor 10 to the condenser 12 is introduced into the third expansion valve 52 along the refrigerant line 11.The third expansion valve 52 can flow the refrigerant supplied from the condenser 12 into the second pipe 62 without expanding the refrigerant.The fourth expansion valve 53 may expand the refrigerant supplied through the second pipe 62 and supply the expanded refrigerant to the heat exchanger 14.The heat exchanger 14 evaporates the introduced refrigerant by heat exchange with a working fluid such as air or refrigerant. The refrigerant discharged from the heat exchanger 14 is introduced into the third refrigerant connection line 56.In this case, the fifth expansion valve 57 can supply the refrigerant to the second gas-liquid separator 55 without expanding the refrigerant introduced from the heat exchanger 14 through the third refrigerant connection line 56.In this case, the second gas-liquid separator 55 may supply the gaseous refrigerant among the refrigerants supplied via the third refrigerant connection line 56 to the compressor 10 via the opened second refrigerant connection line 54 and the opened third line 63.The operation of the first expansion valve 16 and the second expansion valve 26 may be stopped.That is, the refrigerant discharged from the second gas-liquid separator 55 may be introduced into the compressor 10. The introduced refrigerant may be compressed by the operation of the compressor 10.The refrigerant compressed in the compressor 10 is supplied to the condenser 12 via the refrigerant line 11. At this time, the refrigerant supplied to the condenser 12 may increase the temperature of the outside air introduced into the HVAC module.The open-close door is opened to allow the outside air introduced into the HVAC module and directed through the evaporator 18 to flow through the condenser 12.Therefore, the outside air introduced from the outside is introduced in a state of room temperature in which it is not cooled at the time of passing through the evaporator 18 to which the refrigerant is not supplied. The introduced outside air is brought into a high temperature state as it passes through the condenser 12 and then introduced into the interior of the vehicle, so that heating of the vehicle interior can be performed.The refrigerant condensed in the condenser 12 may be supplied to the heat exchanger 14 via the second line 62 and the refrigerant line 11 opened by the operation of the third and fourth expansion valves 52 and 53.That is, the heat pump system can heat the interior of the vehicle without the need to operate the gas injection device 50 while the process is repeatedly performed.Moreover, embodiments of the present invention may recover waste heat from sources of the air or electrical component, e.g., in the condenser 12 and the heat exchanger 14, thereby improving heating efficiency and performance while minimizing the use of separate electrical heaters.The operation according to the fifth mode in which the interior of the vehicle is heated and dehumidified will be described with reference to FIG. 6.FIG. 6 is an operation state diagram according to a fifth mode in the heat pump system for a vehicle according to an embodiment of the present invention.Referring to FIG. 6, in the case of the fifth mode, the compressor 10 is operated to flow the refrigerant along the refrigerant line 11 to heat and de-wet the interior of the vehicle.Here, the first refrigerant communication line 21 is closed by the operation of the second expansion valve 26.A portion of the second refrigerant connection line 54 connecting the second gas-liquid separator 55 and the third line 63 may be opened by the operation of the second valve V 2.The third refrigerant communication line 56 is opened by the operation of the fifth expansion valve 57.Here, the refrigerant line 11 connecting the evaporator 18 to the third refrigerant connection line 56 from the rear end of the heat exchanger 14 may be opened by the operation of the first valve V 1 and the first expansion valve 16.Moreover, a portion of the second refrigerant connection line 54 connecting the second gas-liquid separator 55 and the first valve V 1 may be closed by the operation of the first valve V 1.Here, the front end of the heat exchanger 14 and the rear end of the heat exchanger 14 may be set depending on the flow direction of the refrigerant.That is, based on the direction in which the refrigerant flows along the refrigerant line 11, the position at which the refrigerant is introduced into the heat exchanger 14 may be defined as the leading end of the heat exchanger 14, and the position at which the refrigerant is discharged from the heat exchanger 14 may be defined as the trailing end of the heat exchanger 14.In the present embodiment, the first pipe 61 is closed. The second line 62 may be opened by the operation of the third expansion valve 52 and the fourth expansion valve 53.The third line 63 may be opened by the operation of the second valve V 2.In this case, the refrigerant line 11 connecting the third expansion valve 52, the first gas-liquid separator 51, and the fourth expansion valve 53 may be closed by the operation of the third expansion valve 52 and the fourth expansion valve 53.Then, the refrigerant supplied from the compressor 10 to the condenser 12 is introduced into the third expansion valve 52 along the refrigerant line 11.The third expansion valve 52 can flow the refrigerant supplied from the condenser 12 into the second pipe 62 without expanding the refrigerant.The fourth expansion valve 53 may expand the refrigerant supplied through the second pipe 62 and supply the expanded refrigerant to the heat exchanger 14.The heat exchanger 14 evaporates the introduced refrigerant by heat exchange with a working fluid such as air or refrigerant. A part of the refrigerant discharged from the heat exchanger 14 is introduced into the opened third refrigerant connection line 56.In this case, the fifth expansion valve 57 can supply the refrigerant to the second gas-liquid separator 55 without expanding the refrigerant introduced from the heat exchanger 14 through the third refrigerant connection line 56.In this case, the second gas-liquid separator 55 may supply the gaseous refrigerant among the refrigerants supplied via the third refrigerant connection line 56 to the compressor 10 via the opened second refrigerant connection line 54 and the opened third line 63.The rest of the refrigerant discharged from the heat exchanger 14 is introduced into the first expansion valve 16 via the opened refrigerant line 11.The first expansion valve 16 may expand the refrigerant supplied from the heat exchanger 14 and supply the expanded refrigerant to the evaporator 18. The refrigerant discharged from the evaporator 18 may be supplied to the compressor 10.That is, the refrigerant discharged from the second gas-liquid separator 55 and the refrigerant discharged from the evaporator 18 may be introduced into the compressor 10 together. The introduced refrigerant may be compressed by the operation of the compressor 10.The refrigerant compressed in the compressor 10 is supplied to the condenser 12 via the refrigerant line 11. At this time, the refrigerant supplied to the condenser 12 may increase the temperature of the outside air introduced into the HVAC module.The open-close door is opened to allow the outside air introduced into the HVAC module and directed through the evaporator 18 to flow through the condenser 12.Therefore, the outside air introduced into the HVAC module is dehumidified by the refrigerant introduced into the evaporator 18 and in a low-temperature state while flowing through the evaporator 18. Thereafter, the outside air is brought into the high temperature state as it passes through the condenser 12 and introduced into the interior of the vehicle, thereby uniformly heating and dehumidifying the interior of the vehicle.Therefore, according to the heat pump system for a vehicle according to the embodiments of the present invention, it is possible to improve cooling and heating performance by selectively operating the gas injection device 50 in at least one mode selected for air conditioning of the vehicle interior to increase the flow rate of the refrigerant.According to embodiments of the present invention, it is also possible to selectively efficiently control the temperature of the battery module 3 in at least one mode with a heat exchange device 24 in which the coolant and the refrigerant are heat-exchanged.Moreover, according to embodiments of the present invention, it is possible to simplify the system by maximizing the system performance using the gas injection device 50 while minimizing the components.Moreover, according to an embodiment of the present invention, it is possible to have the optimum performance of the battery module 3 by efficiently controlling the temperature of the battery module 3 and to increase the overall travel distance of the vehicle by effectively controlling the temperature of the battery module 3.Moreover, according to an exemplary embodiment of the present invention, it is possible to reduce manufacturing cost, reduce weight, and improve space utilization by simplifying the overall system.Although the embodiments of the present disclosure have been described above with reference to exemplary embodiments and the drawings, the embodiments of the present disclosure are not limited thereto, but may be variously modified and changed by those skilled in the art without departing from the spirit and scope of the embodiments of the present disclosure defined in the claims.The following terms may be used in conjunction with the drawings to describe various features of embodiments of the present disclosure. 3 Battery module 5 Coolant line 10 Compressor 11 Refrigerant line 12 Condenser 14 Heat exchanger 16 First expansion valve 18 Evaporator 21 First refrigerant connection line 24 Chiller 26 Second expansion valve 50 Gas injection device 51 First gas-liquid separator 52 Third expansion valve 53 Fourth expansion valve 54 Second refrigerant connection line 55 Second gas-liquid separator 56 Third refrigerant connection line 57 Fifth expansion valve 61 First line 62 Second line 63 Third line V 1, V 2 First and second valves

Claims

A heat pump system for a vehicle, comprising: a compressor (10) configured to compress a refrigerant; a condenser (12) connected to the compressor (10) via a refrigerant line (11); a heat exchanger (14) connected to the condenser (12) via the refrigerant line (11) and configured to condense or evaporate the refrigerant; a first expansion valve (16) connected to the heat exchanger (14) via the refrigerant line (11); an evaporator (18) connected to the first expansion valve (16) via the refrigerant line (11); a first refrigerant connection line (21) having a first end connected to the refrigerant line (11) between the compressor (10) and the evaporator (18) and having a second end, which is connected to the refrigerant line (11) between the heat exchanger (14) and the first expansion valve (16), a heat exchange device (24) disposed in the first refrigerant connection line (21) and configured to control a temperature of a refrigerant by selective heat exchange between the refrigerant introduced into the first refrigerant connection line (21) and the refrigerant, a second expansion valve (26) disposed in the first refrigerant connection line (21) at a front end of the heat exchange device (24), and a gas injection device (50) connected to the refrigerant line (11) and configured to selectively expand and flow the refrigerant supplied from the condenser (12) or the heat exchanger (14) and selectively supply a part of the refrigerant to the compressor (10) to increase a flow rate of the refrigerant circulating in the refrigerant line (11), wherein the flow of the refrigerant is controlled according to a mode for controlling a temperature of an interior of the vehicle or a temperature of a battery module (3).The system according to claim 1, wherein the gas injection device (50) further comprises: a first gas-liquid separator (51) disposed in the refrigerant line (11) between the condenser (12) and the heat exchanger (14) and configured to selectively separate the refrigerant into a gaseous refrigerant and a liquid refrigerant and selectively discharge the gaseous refrigerant and the liquid refrigerant; a third expansion valve (52) disposed in the refrigerant line (11) between the condenser (12) and the first gas-liquid separator (51); a fourth expansion valve (53) disposed in the refrigerant line (11) between the first gas-liquid separator (51) and the heat exchanger (14); and a second refrigerant communication line (54), which is connected at a first end to the first gas-liquid separator (51) and at a second end to a first valve (V1) arranged in the refrigerant line (11) between the heat exchanger (14) and the first expansion valve (16), a second gas-liquid separator (55) arranged in the second refrigerant connection line (54), a third refrigerant connection line (56), the first end of which is connected to the refrigerant line (11) between the heat exchanger (14) and the first valve (V1) and the second end of which is connected to the second gas-liquid separator (55), and a fifth expansion valve (57) arranged in the third refrigerant connection line (56).The system according to claim 2, wherein the gas injection device (50) further comprises a first pipe (61) configured to selectively supply the gaseous refrigerant discharged from the first gas-liquid separator (51) or the second gas-liquid separator (55) to the compressor (10), a first end of the first pipe (61) being connected to the second refrigerant connection pipe (54) between the first gas-liquid separator (51) and the second gas-liquid separator (55), and a second end being connected to the compressor (10).The system according to claim 3, wherein the first gas-liquid separator (51) is configured to be operated in a state in which the third expansion valve (52) expands and supplies the refrigerant while heating the interior of the vehicle, and supplies the gaseous refrigerant to the compressor (10) via the first pipe (61) to increase the flow rate of the refrigerant circulating in the refrigerant pipe (11).The system according to claim 3 or 4, wherein the second gas-liquid separator (55) is configured to be operated in a state in which the fifth expansion valve (57) expands and supplies the refrigerant while cooling the interior of the vehicle, and supplies the gaseous refrigerant to the compressor (10) via the first pipe (61) to increase the flow rate of the refrigerant circulating in the refrigerant pipe (11).The system according to claim 3, 4 or 5, wherein the gas injection device (50) further comprises a second pipe (62) connected between the third expansion valve (52) and the fourth expansion valve (53) and configured to selectively redirect the refrigerant supplied from the condenser (12) to the heat exchanger (14) according to an operation of the third expansion valve (52) and the fourth expansion valve (53) without passing through the first gas-liquid separator (51).The system according to any one of claims 2 to 6, wherein the gas injection device (50) further comprises a second valve (V2) disposed in the second refrigerant connection line (54) between the first gas-liquid separator (51) and the second gas-liquid separator (55), and a third line (63) having a first end connected to the second valve (V2) and a second end connected to the refrigerant line (11) between the evaporator (18) and the compressor (10).The system according to claim 7, wherein the mode is selected from a plurality of modes including a first mode in which the gas injection device (50) is operated and the battery module (3) is cooled while cooling the interior of the vehicle, a second mode in which the gas injection device (50) is operated and the interior of the vehicle is heated, a third mode in which the gas injection device (50) is not operated and the battery module (3) is cooled while cooling the interior of the vehicle, a fourth mode in which the gas injection device (50) is not operated and the interior of the vehicle is heated, and a fifth mode in which the interior of the vehicle is heated and dehumidified.The system according to claim 8, wherein in a case where the mode is the first mode: the first refrigerant connection line (21) is configured to be opened by an operation of the second expansion valve (26), the second refrigerant connection line (54) is configured to be opened by an operation of the first valve (V1), the third refrigerant connection line (56) is configured to be opened by an operation of the fifth expansion valve (57), a portion of the refrigerant line (11) connecting the third refrigerant connection line (56) and the first valve (V1) is configured to be closed by an operation of the first valve (V1), the first line (61, 62) is configured to be opened by an operation of the second valve (V2), the second line (62) is configured to be opened, to be opened by operation of the third expansion valve (52) and the fourth expansion valve (53), the third pipe (63) is configured to be closed by operation of the second valve (V2), the refrigerant pipe (11) connecting the third expansion valve (52), the first gas-liquid separator (51), and the fourth expansion valve (53) is configured to be closed by operation of the third expansion valve (52) and the fourth expansion valve (53), the first expansion valve (16) is configured to expand the refrigerant introduced from the second gas-liquid separator (55) along the refrigerant pipe (11) and supply the expanded refrigerant to the evaporator (18), the second expansion valve (26) is configured to be closed, to expand the refrigerant introduced into the first refrigerant connection line (21) and supply the expanded refrigerant to the heat exchange device (24), the third expansion valve (52) is configured to flow the refrigerant supplied from the condenser (12) into the second line (62) without expanding the refrigerant, the fourth expansion valve (53) is configured to allow the refrigerant supplied through the second line (62) to flow into the heat exchanger (14) without expanding the refrigerant, the fifth expansion valve (57) is configured to expand the refrigerant introduced from the heat exchanger (14) through the third refrigerant connection line (56) and supply the expanded refrigerant to the second gas-liquid separator (55), and the second gas-liquid separator (55) is configured to, to supply the gaseous refrigerant supplied through the third refrigerant connection line (56) to the compressor (10) through the opened second refrigerant connection line (54) and the first line (61), and to discharge the liquid refrigerant into the refrigerant line (11) through the first valve (V1).The system according to claim 8 or 9, wherein in a case where the mode is the second mode: the first refrigerant connection line (21) is configured to be closed by an operation of the second expansion valve (26), the second refrigerant connection line (54) has a portion connecting the first gas-liquid separator (51) and the first line (61), and has a portion connecting the second gas-liquid separator (55) and the third line (63) configured to be opened, the third refrigerant connection line (56) is configured to be opened by an operation of the fifth expansion valve (57), the refrigerant line (11) connecting the evaporator (18) from a rear end of the heat exchanger (14) with respect to the third refrigerant connection line (56) is configured to be closed, the first pipe (61) is configured to be opened, the second pipe (62) is configured to be closed by the operation of the third expansion valve (52) and the fourth expansion valve (53), the third pipe (63) is configured to be opened by the operation of the second valve (V2), the refrigerant pipe (11) connecting the third expansion valve (52), the first gas-liquid separator (51), and the fourth expansion valve (53) is configured to be opened by the operation of the third expansion valve (52) and the fourth expansion valve (53), an operation of the first expansion valve (16) and the second expansion valve (26) is stopped, the third expansion valve (52) is configured to be opened, to expand the refrigerant supplied from the condenser (12) and supply the expanded refrigerant to the first gas-liquid separator (51), the fourth expansion valve (53) is configured to expand the refrigerant supplied from the first gas-liquid separator (51) and supply the expanded refrigerant to the heat exchanger (14), the fifth expansion valve (57) is configured to supply the refrigerant introduced from the heat exchanger (14) through the third refrigerant connection line (56) to the second gas-liquid separator (55) without expanding the refrigerant, the first gas-liquid separator (51) is configured to supply the gaseous refrigerant through the opened first line (61) to the compressor (10), and the second gas-liquid separator (55) is configured to, in order to supply the gaseous refrigerant supplied through the third refrigerant connecting line (56) to the compressor (10) through the opened third line (63).The system according to claim 8, 9 or 10, wherein in a case where the mode is the third mode: the first refrigerant connection line (21) is configured to be opened by an operation of the second expansion valve (26), the second refrigerant connection line (54) is configured to be closed by an operation of the first valve (V1), the third refrigerant connection line (56) is configured to be closed by an operation of the fifth expansion valve (57), the first line (61) is configured to be closed, the second line (62) is configured to be opened by the operation of the third expansion valve (52) and the fourth expansion valve (53), the third line (63) is configured to be closed by the operation of the second valve (V2), the refrigerant line (11), which connects the third expansion valve (52), the first gas-liquid separator (51), and the fourth expansion valve (53) is configured to be closed by the operation of the third expansion valve (52) and the fourth expansion valve (53), the first expansion valve (16) is configured to expand the refrigerant introduced from the heat exchanger (14) along the refrigerant line (11) and supply the expanded refrigerant to the evaporator (18), the second expansion valve (26) is configured to expand the refrigerant introduced into the first refrigerant connection line (21) and supply the expanded refrigerant to the heat exchange device (24), the third expansion valve (52) is configured to flow the refrigerant supplied from the condenser (12) into the second line (62) without expanding the refrigerant, the fourth expansion valve (53) is configured to, to allow the refrigerant supplied via the second pipe (62) to flow into the heat exchanger (14) without expanding the refrigerant, and the operation of the fifth expansion valve (57) is stopped.The system according to any one of claims 8 to 11, wherein in a case where the mode is the fourth mode: the first refrigerant connection line (21) is configured to be closed by an operation of the second expansion valve (26), a portion of the second refrigerant connection line (54) connecting the second gas-liquid separator (55) and the third line (63) is configured to be opened by an operation of the second valve (V2), the third refrigerant connection line (56) is configured to be opened by an operation of the fifth expansion valve (57), the refrigerant line (11) connecting the evaporator (18) from a rear end of the heat exchanger (14) with respect to the third refrigerant connection line (56) is configured to be closed, the first line (61) is configured to be closed, the second pipe (62) is configured to be opened by the operation of the third expansion valve (52) and the fourth expansion valve (53), the third pipe (63) is configured to be opened by an operation of the second valve (V 2), the refrigerant pipe (11) connecting the third expansion valve (52), the first gas-liquid separator (51), and the fourth expansion valve (53) is configured to be closed by the operation of the third expansion valve (52) and the fourth expansion valve (53), the operation of the first expansion valve (16) and the second expansion valve (26) is stopped, the third expansion valve (52) is configured to flow the refrigerant supplied from the condenser (12) into the second pipe (62) without expanding the refrigerant, the fourth expansion valve (53) is configured to, to expand the refrigerant supplied through the second pipe (62) and to flow the expanded refrigerant into the heat exchanger (14), the fifth expansion valve (57) is configured to supply the refrigerant introduced into the third refrigerant connection pipe (56) to the second gas-liquid separator (55) without expanding the refrigerant, and the second gas-liquid separator (55) is configured to supply the gaseous refrigerant supplied through the third refrigerant connection pipe (56) to the compressor (10) through the opened third pipe (63).The system according to any one of claims 8 to 12, wherein in a case where the mode is the fifth mode, the first refrigerant connection line (21) is configured to be closed by an operation of the second expansion valve (26), a portion of the second refrigerant connection line (54) connecting the second gas-liquid separator (55) and the third line (63) is configured to be opened by an operation of the second valve (V2), the third refrigerant connection line (56) is configured to be opened by an operation of the fifth expansion valve (57), the refrigerant line (11) connecting the evaporator (18) from a rear end of the heat exchanger (14) with respect to the third refrigerant connection line (56) is configured to be opened, to be opened by operation of the first valve (V 1) and the first expansion valve (16), the first pipe (61) is configured to be closed, the second pipe (62) is configured to be opened by operation of the third expansion valve (52) and the fourth expansion valve (53), the third pipe (63) is configured to be opened by operation of the second valve (V 2), the refrigerant pipe (11) connecting the third expansion valve (52), the first gas-liquid separator (51), and the fourth expansion valve (53) is configured to be closed by operation of the third expansion valve (52) and the fourth expansion valve (53), the first expansion valve (16) is configured to be closed, to selectively expand the refrigerant supplied from the heat exchanger (14) and supply the expanded refrigerant to the evaporator (18), an operation of the second expansion valve (26) is stopped, the third expansion valve (52) is configured to flow the refrigerant supplied from the condenser (12) into the second pipe (62) without expanding the refrigerant, the fourth expansion valve (53) is configured to expand the refrigerant supplied through the second pipe (62) and to flow the expanded refrigerant into the heat exchanger (14), the fifth expansion valve (57) is configured to supply the refrigerant introduced into the third refrigerant connection pipe (56) to the second gas-liquid separator (55) without expanding the refrigerant, and the second gas-liquid separator (55) is configured to, in order to supply the gaseous refrigerant supplied through the third refrigerant connecting line (56) to the compressor (10) through the opened third line (63).The system according to any one of claims 8 to 13, wherein the heat exchanger (14) is configured to condense the refrigerant in the first mode and the third mode.The system according to any one of claims 8 to 14, wherein the heat exchanger (14) is configured to evaporate the refrigerant in the second mode, the fourth mode and the fifth mode.The system according to any one of claims 2 to 15, wherein the first expansion valve (16), the second expansion valve (26), and the fifth expansion valve (57) include 2-way expansion valves configured to be selectively operated in a mode and selectively expand the refrigerant while controlling the flow of the refrigerant.The system according to any one of claims 2 to 16, wherein the third expansion valve (52) and the fourth expansion valve (53) comprise 3-way electronic expansion valves configured to be selectively operated in a mode and selectively expand the refrigerant while controlling the flow of the refrigerant.A heat pump system for a vehicle, the system comprising: a compressor (10) configured to compress a refrigerant; a condenser (12) connected to the compressor (10) via a refrigerant line (11); a heat exchanger (14) connected to the condenser (12) via the refrigerant line (11) and configured to condense or evaporate the refrigerant; a first expansion valve (16) connected to the heat exchanger (14) via the refrigerant line (11); an evaporator (18) connected to the first expansion valve (16) via the refrigerant line (11); a first refrigerant connection line (21) having a first end connected to the refrigerant line (11) between the compressor (10) and the evaporator (18) and a second end, which is connected to the refrigerant line (11) between the heat exchanger (14) and the first expansion valve (16), a heat exchange device (24) disposed in the first refrigerant connection line (21) and configured to control a temperature of a refrigerant by selective heat exchange between the refrigerant introduced into the first refrigerant connection line (21) and the refrigerant, a second expansion valve (26) disposed on the first refrigerant connection line (21) at a front end of the heat exchange device (24), and a gas injection device (50) connected to the refrigerant line (11) and configured to selectively expand and flow the refrigerant supplied from the condenser (12) or the heat exchanger (14) and selectively supply a part of the refrigerant to the compressor (10) to increase a flow rate of the refrigerant circulating in the refrigerant line (11), wherein the flow of the refrigerant is controlled according to a mode for controlling a temperature of an interior of the vehicle or a temperature of a battery module (3), and wherein the heat exchange device (24) is connected to the battery module (3) through a coolant line (5) configured to allow the coolant to circulate therethrough.The system according to claim 18, wherein the coolant line (5) is in an open state in a state of cooling the battery module (3) to connect the heat exchange device (24) and the battery module (3).A heat pump system for a vehicle, the system comprising: a compressor (10) configured to compress a refrigerant; a condenser (12) connected to the compressor (10) via a refrigerant line (11); a heat exchanger (14) connected to the condenser (12) via the refrigerant line (11) and configured to condense or evaporate the refrigerant; a first expansion valve (16) connected to the heat exchanger (14) via the refrigerant line (11); an evaporator (18) connected to the first expansion valve (16) via the refrigerant line (11); a first refrigerant connection line (21) having a first end connected to the refrigerant line (11) between the compressor (10) and the evaporator (18) and having a second end, which is connected to the refrigerant line (11) between the heat exchanger (14) and the first expansion valve (16), a heat exchange device (24) disposed in the first refrigerant connection line (21) and configured to control a temperature of a refrigerant by selective heat exchange between the refrigerant introduced into the first refrigerant connection line (21) and the refrigerant, a second expansion valve (26) disposed on the first refrigerant connection line (21) at a front end of the heat exchange device (24), and a gas injection device (50) connected to the refrigerant line (11) and configured to selectively expand and flow the refrigerant supplied from the condenser (12) or the heat exchanger (14) and selectively supply a part of the refrigerant to the compressor (10) to increase a flow rate of the refrigerant circulating in the refrigerant line (11), wherein the flow of the refrigerant is controlled according to a selected mode for controlling a temperature of an interior of the vehicle or a temperature of a battery module (3), the selected mode being selected from a plurality of modes, the plurality of modes including: a first mode in which the gas injection device (50) is operated and the battery module (3) is cooled while the interior of the vehicle is cooled, a second mode in which the gas injection device (50) is operated and the interior of the vehicle is heated, a third mode in which the gas injection device (50) is not operated and the battery module (3) is cooled while the interior of the vehicle is cooled, a fourth mode in which the gas injection device (50) is not operated and the interior of the vehicle is heated, and a fifth mode, in which the interior of the vehicle is heated and dehumidified.

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