Vehicle heat pump system

Abstract

Disclosed is a vehicle heat pump system that can perform all of the functions of cooling, heating, and dehumidification while reducing the size of a package of an air conditioning device, and uses only two refrigerant valves, and thus can improve price competitiveness. The vehicle heat pump system is provided with: a compressor that compresses a refrigerant and discharges same; an indoor heat exchanger that is provided inside an air conditioning case and exchanges heat with air discharged into a vehicle interior; an outdoor heat exchanger that is provided outside the air conditioning case and exchanges heat with outside air; an expansion valve that controls the flow direction of the refrigerant and can selectively expand the refrigerant; a chiller that exchanges heat between the refrigerant and cooling water; and a direction-switching valve that controls the flow of the refrigerant, discharged from the compressor, so that the refrigerant flows selectively to the outdoor heat exchanger or the indoor heat exchanger. The expansion valve includes a plurality of communication ports, and at least two of the plurality of communication ports can be changed to an inlet or an outlet of the refrigerant depending on a mode.

Description

Heat pump system for vehicles

[0001] The present invention relates to a heat pump system for a vehicle, and more particularly, to a heat pump system for a vehicle capable of implementing cooling and heating according to a mode through an indoor heat exchanger by changing the flow direction of a refrigerant.

[0002] Typically, a vehicle air conditioning system comprises a cooling system for cooling the vehicle's interior and a heating system for heating the vehicle's interior. The cooling system, on the interior heat exchanger side of the refrigerant cycle, converts air passing through the exterior of the interior heat exchanger into cold air by exchanging heat with the refrigerant flowing within the evaporator, thereby cooling the vehicle's interior. Furthermore, the heating system, on the heater core side of the coolant cycle, converts air passing through the exterior of the heater core into warm air by exchanging heat with the coolant flowing within the heater core, thereby heating the vehicle's interior.

[0003] Meanwhile, a heat pump system is being applied that can selectively perform cooling and heating by switching the flow direction of the refrigerant using one refrigerant cycle, which is different from the aforementioned vehicle air conditioning system.

[0004] The heat pump system is equipped with an indoor heat exchanger installed inside the air conditioning case to exchange heat with air blown into the vehicle interior, an outdoor heat exchanger to exchange heat outside the air conditioning case, and a directional control valve that can change the flow direction of the refrigerant. Depending on the flow direction of the refrigerant by the directional control valve, when the cooling mode is activated, the indoor heat exchanger performs the function of a cooling heat exchanger, and when the heating mode is activated, the indoor heat exchanger performs the function of a heating heat exchanger.

[0005] Referring to FIG. 1, a conventional vehicle heat pump system includes an indoor heat exchanger (15), an auxiliary heat exchanger (11), an outdoor heat exchanger (10), a four-way valve (20), and a three-way valve (30).

[0006] The indoor heat exchanger (15) is placed inside the case (16) within the vehicle interior and exchanges heat with the air supplied to the interior. The indoor heat exchanger (15) selectively switches between condenser and evaporator functions depending on the operating mode. An auxiliary heat exchanger (11) is provided downstream of the indoor heat exchanger (15) in the direction of air flow within the case (16).

[0007] The auxiliary heat exchanger (11) operates as an evaporator when the indoor heat exchanger (15) operates as a condenser, and operates as a condenser when the indoor heat exchanger (15) operates as an evaporator. The outdoor heat exchanger (10) exchanges heat with the outdoor air, and the refrigerant passing through the indoor heat exchanger (15) passes through a four-way valve (20) that is controlled to allow for optional reverse cycle circulation. A three-way valve (30) is provided so that the refrigerant passing through the four-way valve (20) can be selectively branched and flow to the auxiliary heat exchanger (11).

[0008] A vehicle heat pump system comprises a first line (1), a second line (2), and a third line (3). Refrigerant passing through a four-way valve (20) via the first line (1) is constantly recirculated to the four-way valve (20). An accumulator (32) for separating the vapor and liquid of the refrigerant and a compressor (33) are provided in the first line (1). A three-way valve (30) is installed on the first line (1), and the second line (2) is connected to the three-way valve (30).

[0009] The refrigerant passing through the three-way valve (30) is optionally branched to the auxiliary heat exchanger (11). The third line (3) allows the refrigerant passing through the auxiliary heat exchanger (11) to be supplied to the accumulator (32). The third line (3) is provided with a connection port (31) so that the refrigerant passing through the auxiliary heat exchanger (11) can be connected to the accumulator (32). An expansion valve (12) that performs a throttling action is provided between the indoor heat exchanger (15) and the outdoor heat exchanger (10).

[0010] In cooling mode, the refrigerant discharged from the compressor (33) condenses while passing through the outdoor heat exchanger (10) via the four-way valve (20), expands while passing through the expansion valve (12), and evaporates while passing through the indoor heat exchanger (15). Thereafter, the refrigerant passes through the four-way valve (20), the three-way valve (30), the auxiliary heat exchanger (11), and then circulates through the compressor (33).

[0011] In heating mode, the refrigerant discharged from the compressor (33) condenses while passing through the indoor heat exchanger (15) via the four-way valve (20), expands while passing through the expansion valve (12), and evaporates while passing through the outdoor heat exchanger (10). Thereafter, the refrigerant passes through the four-way valve (20) and the three-way valve (30) and circulates through the compressor (33). In this case, the refrigerant passing through the three-way valve (30) bypasses the auxiliary heat exchanger (11).

[0012] In dehumidification mode, the refrigerant discharged from the compressor (33) condenses while passing through the indoor heat exchanger (15) via the four-way valve (20), expands while passing through the expansion valve (12), and evaporates while passing through the outdoor heat exchanger (10). Thereafter, the refrigerant evaporates while passing through the four-way valve (20), the three-way valve (30), and the auxiliary heat exchanger (11), and then circulates through the compressor (33).

[0013] Conventional vehicle heat pump systems require the interior heat exchanger (15) and auxiliary heat exchanger (11) to be positioned within the case (16). This inevitably increases the weight and packaging size to a comparable level compared to air conditioning systems equipped with an evaporator and heater core. Furthermore, the auxiliary heat exchanger is not used in heating mode, so it only takes up space and does not improve air conditioning performance.

[0014] In addition, the conventional vehicle heat pump system does not use the auxiliary heat exchanger (11) in the heating mode. Furthermore, the conventional vehicle heat pump system requires an inlet and outlet pipe for the indoor heat exchanger, and an inlet and outlet pipe for the auxiliary heat exchanger. Consequently, the conventional vehicle heat pump system requires a total of four pipes connecting the engine compartment and the interior of the vehicle. Meanwhile, the indoor heat exchanger (15) and the auxiliary heat exchanger (11) are used in the heating and dehumidifying mode.

[0015] In order to solve such conventional problems, the present invention provides a vehicle heat pump system that can implement all cooling, heating, and dehumidifying functions while reducing the package of the air conditioning device and can improve price competitiveness by using only two refrigerant valves.

[0016] A vehicle heat pump system according to the present invention comprises: a compressor for compressing and discharging a refrigerant; an indoor heat exchanger provided inside an air conditioning case for exchanging heat with air discharged into a vehicle interior; an outdoor heat exchanger provided outside the air conditioning case for exchanging heat with outside air; an expansion valve for controlling the flow direction of the refrigerant and selectively expanding the refrigerant; a chiller for exchanging heat between the refrigerant and cooling water; and a direction changing valve for controlling the flow of the refrigerant discharged from the compressor so that it selectively flows to the outdoor heat exchanger or the indoor heat exchanger, wherein the expansion valve includes a plurality of communication ports, and at least two of the plurality of communication ports are configured to be changed to an inlet or an outlet of the refrigerant depending on a mode.

[0017] The above expansion valve can be configured to allow the gas to flow into one opening and be expanded and discharged through openings in different directions, depending on the mode.

[0018] The above expansion valve selectively expands and sends the refrigerant that has passed through the outdoor heat exchanger to the indoor heat exchanger or chiller, or selectively expands and sends the refrigerant that has passed through the indoor heat exchanger to the outdoor heat exchanger or chiller.

[0019] The above expansion valve has a first communication port connected to an outdoor heat exchanger, a second communication port connected to a chiller, and a third communication port connected to an indoor heat exchanger, and introduces refrigerant into the first communication port and expands the refrigerant and sends it to the second or third communication port, or introduces refrigerant into the third communication port and expands the refrigerant and sends it to the first or second communication port.

[0020] The above directional valve is composed of a four-way valve connected to the compressor, outdoor heat exchanger, indoor heat exchanger, chiller, and refrigerant line between the compressor.

[0021] A chiller refrigerant line is provided that branches from the refrigerant line between the outdoor heat exchanger and the indoor heat exchanger and is connected to the chiller, and the expansion valve is provided at a branch point of the chiller refrigerant line.

[0022] A connecting pipe formed on the downstream side of the directional change valve in the direction of refrigerant flow is further provided so that the refrigerant passing through the directional change valve can flow to the compressor.

[0023] In cooling mode, the refrigerant discharged from the compressor passes through the outdoor heat exchanger via the direction change valve, expands in the expansion valve, and then passes through the indoor heat exchanger to circulate through the compressor. In this case, the second communication port of the expansion valve is closed.

[0024] In cooling and battery cooling mode, the refrigerant discharged from the compressor passes through the outdoor heat exchanger via the direction change valve, expands in the expansion valve, and then some of it passes through the indoor heat exchanger and circulates through the compressor, while the other part passes through the chiller via the chiller refrigerant line and circulates through the compressor. In this case, the expanded refrigerant is discharged through both the second and third communication ports of the expansion valve.

[0025] In battery cooling mode, the refrigerant discharged from the compressor passes through the outdoor heat exchanger via the directional valve, expands in the expansion valve, and then passes through the chiller and circulates through the compressor. In this case, the third communication port of the expansion valve is closed.

[0026] In the dehumidifying heating mode, the refrigerant discharged from the compressor passes through the outdoor heat exchanger via the direction changing valve, expands in the expansion valve, and then passes through the indoor heat exchanger and circulates through the compressor. In this case, the second communication port of the expansion valve is closed, and heating is performed by heating the air through the operation of the electric heater provided downstream of the indoor heat exchanger in the direction of air flow.

[0027] In the first heating mode, the refrigerant discharged from the compressor passes through the indoor heat exchanger via the directional valve, expands in the expansion valve, and then some of it passes through the outdoor heat exchanger and circulates through the compressor, while the other part passes through the chiller via the chiller refrigerant line and circulates through the compressor. In this case, the expanded refrigerant is discharged through both the first and second communication ports of the expansion valve.

[0028] In the second heating mode, the refrigerant discharged from the compressor passes through the indoor heat exchanger via the direction change valve, is expanded in the expansion valve, and then passes through the outdoor heat exchanger and circulates through the compressor. In this case, the second communication port of the expansion valve is closed.

[0029] In the third heating mode, the refrigerant discharged from the compressor passes through the indoor heat exchanger via the direction change valve, is expanded in the expansion valve, and then passes through the chiller and circulates through the compressor. In this case, the first communication port of the expansion valve is closed.

[0030] The vehicle heat pump system according to the present invention can reduce the overall package of the air conditioning system by using only one heat exchanger within the air conditioning case. That is, the present invention can reduce the overall package of the air conditioning system by using only one heat exchanger through which refrigerant flows to the cooling section. Furthermore, compared to the prior art that uses two heat exchangers, the work required for piping and connecting the piping can be reduced.

[0031] In addition, by configuring the refrigerant valves with two (one directional valve and one expansion valve) and implementing various air conditioning modes such as cooling, heating, dehumidification, and battery cooling, the manufacturing cost can be drastically reduced and price competitiveness can be increased.

[0032] Figure 1 illustrates a conventional vehicle heat pump system.

[0033] FIG. 2 illustrates a vehicle heat pump system according to one embodiment of the present invention.

[0034] FIG. 3 illustrates a direction change valve of a vehicle heat pump system according to one embodiment of the present invention.

[0035] FIG. 4 illustrates an expansion valve of a vehicle heat pump system according to one embodiment of the present invention.

[0036] FIG. 5 is a drawing for explaining the operation mode of an expansion valve according to one embodiment of the present invention.

[0037] FIG. 6 illustrates a cooling mode of a vehicle heat pump system according to one embodiment of the present invention.

[0038] FIG. 7 illustrates the cooling and battery cooling modes of a vehicle heat pump system according to one embodiment of the present invention.

[0039] FIG. 8 illustrates a battery cooling mode of a vehicle heat pump system according to an embodiment of the present invention.

[0040] FIG. 9 illustrates a dehumidifying heating mode of a vehicle heat pump system according to an embodiment of the present invention.

[0041] FIG. 10 illustrates a first heating mode of a vehicle heat pump system according to one embodiment of the present invention.

[0042] FIG. 11 illustrates a second heating mode of a vehicle heat pump system according to an embodiment of the present invention.

[0043] FIG. 12 illustrates a third heating mode of a vehicle heat pump system according to one embodiment of the present invention.

[0044] The technical configuration of a vehicle heat pump system is described in detail according to the attached drawings as follows.

[0045] Referring to FIGS. 2 to 5, a vehicle heat pump system according to one embodiment of the present invention comprises a compressor (101) connected to a refrigerant line (191), an outdoor heat exchanger (102), an expansion valve (200), an indoor heat exchanger (121), and a chiller (104).

[0046] A blower is provided on one side of the air conditioning case (120) to suck in internal or external air and discharge it into the vehicle interior, and an indoor heat exchanger (121) is provided in the internal air passage of the air conditioning case (120). An electric heater (123) is provided downstream of the indoor heat exchanger (121) in the air flow direction within the air conditioning case (120). The electric heater (123) generates heat when power is applied, and may be formed of a PTC heater, etc.

[0047] The electric heater (123) functions as an auxiliary heat source and functions as a heat source that heats the air in the dehumidifying heating mode. The electric heater (123) is configured with dual PTCs and can be operated individually in the air passages partitioned on the left and right sides of the air conditioning case (120). A temp door (122) is provided between the indoor heat exchanger (121) and the electric heater (123) to control the discharge temperature of the air by controlling the amount of cold air and hot air.

[0048] The compressor (101) sucks in refrigerant, compresses it, and then discharges it as a high-temperature, high-pressure gas. The outdoor heat exchanger (102) is provided outside the air conditioning case (120) to exchange heat with the outside air, and can be installed in the front of the vehicle, etc. The indoor heat exchanger (121) is provided inside the air conditioning case (120) to exchange heat with the air discharged into the vehicle interior.

[0049] An accumulator (105) is provided upstream of the compressor (101) in the direction of refrigerant flow to separate the vapor and liquid of the refrigerant passing therethrough. In addition, a double pipe (103) is formed in the refrigerant pipe connecting the accumulator (105) and the compressor (101). The double pipe (103) exchanges heat between the refrigerant in the refrigerant line (191) connecting the outdoor heat exchanger (102) and the expansion valve (200) and the refrigerant in the refrigerant line (191) connecting the accumulator (105) and the compressor (101).

[0050] The indoor heat exchanger (121) functions as a cooling heat exchanger that cools the air or as a heating heat exchanger that heats the air. The expansion valve (200) expands the refrigerant. The chiller (104) is a refrigerant-coolant heat exchanger that exchanges heat between the refrigerant and the coolant circulating through the vehicle's electrical components or batteries.

[0051] The indoor heat exchanger (121) functions as an evaporator in cooling mode, absorbing heat from air blown into the vehicle interior, and functions as a condenser in heating mode, generating heat from air blown into the vehicle interior. In this way, the indoor heat exchanger (121) performs opposite functions in cooling mode and heating mode.

[0052] A vehicle heat pump system according to one embodiment of the present invention controls the flow of refrigerant discharged from a compressor (101) and blows air passing through an indoor heat exchanger (121) into the vehicle interior to perform a series of air conditioning operations, such as cooling, heating, dehumidification, and battery cooling, within the vehicle interior. In this case, the indoor heat exchanger (121) may be provided in a plurality of rows separated on an air passage within an air conditioning case (120). The indoor heat exchanger (121) is configured as an integrated heat exchanger separated into a plurality of rows.

[0053] A vehicle heat pump system according to one embodiment of the present invention comprises a chiller refrigerant line (192). In addition, the vehicle heat pump system further comprises a direction change valve (110). The chiller refrigerant line (192) branches from the refrigerant line between the outdoor heat exchanger (102) and the indoor heat exchanger (121) and is connected to the chiller (104).

[0054] The directional switching valve (110) controls the flow of refrigerant discharged from the compressor (101) to selectively flow to the outdoor heat exchanger (102) or the indoor heat exchanger (121). The directional switching valve (110) is composed of a 4-way valve. The directional switching valve (110) is connected to the refrigerant lines between the compressor (101), the outdoor heat exchanger (102), the indoor heat exchanger (121), the chiller (104), and the compressor (101).

[0055] An expansion valve (200) is configured to control the flow direction of refrigerant and selectively expand the refrigerant. The expansion valve includes a plurality of communication ports, and at least two of the plurality of communication ports are configured to be changed to serve as inlets or outlets for the refrigerant depending on the mode. In addition, the expansion valve is configured to allow refrigerant to flow into one communication port and expand and discharge through communication ports in different directions depending on the mode.

[0056] That is, the expansion valve (200) is composed of an electric expansion valve (EXV) and is composed of a three-way valve. The expansion valve (200) is configured so that two of the three communication ports can be changed to the inlet and outlet of the refrigerant, thereby enabling bidirectional expansion of the refrigerant.

[0057] In addition, the expansion valve (200) selectively expands and sends the refrigerant that has passed through the outdoor heat exchanger (102) to the indoor heat exchanger (121) or the chiller (104), or selectively expands and sends the refrigerant that has passed through the indoor heat exchanger (121) to the outdoor heat exchanger (102) or the chiller (104). The expansion valve (200) is provided at a branch point of the chiller refrigerant line (192).

[0058] The expansion valve (200) performs not only the expansion function of the refrigerant but also the directional function of changing the flow of the refrigerant, and can change the inlet and outlet during the expansion of the refrigerant. That is, the expansion valve (200) has three communication ports that selectively function as the inlet or outlet of the refrigerant depending on the air conditioning mode.

[0059] More specifically, the expansion valve (200) has a first communication port (210), a second communication port (220), and a third communication port (230). The first communication port (210) is connected to the outdoor heat exchanger (102), the second communication port (220) is connected to the chiller (104), and the third communication port (230) is connected to the indoor heat exchanger (121). Refrigerant may be introduced into the first communication port (210) to expand and send the refrigerant to the second communication port (220) or the third communication port (230), or the refrigerant may be introduced into the third communication port (230) to expand and send the refrigerant to the first communication port (210) or the second communication port (220).

[0060] As shown in Fig. 5, the expansion valve (200) is not a 3-way valve that simply changes direction, nor is it a throttle that performs one-way expansion, but is a three-way valve that can expand in multiple directions. That is, the three-way valve according to the present invention may be in a state where the second communication port is closed and the refrigerant flows into the first communication port, expands, and then flows into the third communication port (mode 1), or in a state where the second communication port is closed and the refrigerant flows into the third communication port, expands, and then flows into the first communication port (mode 1), or in a state where the first communication port is closed and the refrigerant flows into the third communication port, expands, and then flows into the second communication port (mode 2), or in a state where the third communication port is closed and the refrigerant flows into the first communication port, expands, and then flows into the second communication port (mode 3), or in a state where the refrigerant flows into the third communication port, expands, and then flows into the first and second communication ports simultaneously (mode 4), or in a state where the refrigerant flows into the first communication port, expands, and then flows into the second and third communication ports simultaneously (mode 4). In this way, the expansion inlet and outlet of the expansion valve (200) are configured to be changeable.

[0061] Meanwhile, the vehicle heat pump system further comprises a connecting pipe (163). The connecting pipe (163) is formed downstream of the directional switching valve in the direction of refrigerant flow so that the refrigerant passing through the directional switching valve (110) can flow to the compressor (101). That is, the refrigerant passing through the directional switching valve (110) passes through the connecting pipe (163), passes through the accumulator (105), and then flows to the compressor (101).

[0062] A vehicle heat pump system according to one embodiment of the present invention performs air conditioning, such as cooling, heating, dehumidification, and battery cooling, within a vehicle using a single indoor heat exchanger (121). To this end, various air conditioning modes can be implemented using a single directional switching valve (4-way valve) and a single expansion valve (3-way valve). In particular, the expansion valve (200) is configured to enable bidirectional expansion of the refrigerant.

[0063] Through this configuration, the overall package of the air conditioning unit can be reduced by applying only one heat exchanger within the air conditioning case (120). In addition, by configuring the refrigerant valves with two (one directional valve and one expansion valve), various air conditioning modes such as cooling, heating, dehumidification, and battery cooling can be implemented, thereby drastically reducing manufacturing costs and increasing price competitiveness.

[0064] Referring to Fig. 6, in the cooling mode (Only A / C Mode), the high temperature and high pressure refrigerant discharged from the compressor (101) passes through the outdoor heat exchanger (102) via the directional change valve (110), exchanges heat with the outdoor air, and then expands in the expansion valve (200). The refrigerant expanded in the expansion valve (200) passes through the indoor heat exchanger (121), passes through the directional change valve (110), passes through the accumulator (105), and circulates through the compressor (101). The refrigerant passing through the indoor heat exchanger (121) exchanges heat with the air blown into the vehicle interior to perform cooling.

[0065] In this case, the second communication port (220) of the expansion valve (200) is closed and the refrigerant does not flow to the chiller (104). The refrigerant flowing into the first communication port (210) of the expansion valve (200) expands and flows out through the third communication port (230) to the indoor heat exchanger (121). The temp door (122) closes the hot air passage passing through the electric heater (123).

[0066] Referring to Fig. 7, in the A / C and Battery Cooling Mode, the high temperature and high pressure refrigerant discharged from the compressor (101) passes through the outdoor heat exchanger (102) via the directional change valve (110) and exchanges heat with the outdoor air before being expanded in the expansion valve (200). A portion of the refrigerant expanded in the expansion valve (200) passes through the indoor heat exchanger (121), passes through the directional change valve (110), passes through the accumulator (105), and circulates through the compressor (101). The refrigerant passing through the indoor heat exchanger (121) exchanges heat with the air blown into the vehicle interior to perform cooling.

[0067] Another portion of the refrigerant expanded in the expansion valve (200) passes through the chiller refrigerant line (192) to the chiller (104), cools the coolant circulating in the battery, and then passes through the accumulator (105) to circulate through the compressor (101). That is, the refrigerant that has passed through the directional valve (110) flows into the connecting pipe (163) and into the accumulator (105). In this case, the expanded refrigerant is discharged through both the second communication port (220) and the third communication port (230) of the expansion valve (200). That is, the refrigerant that has entered the first communication port (210) of the expansion valve (200) expands, and some of it flows out through the second communication port (220) to the chiller (104), and another portion flows out through the third communication port (230) to the indoor heat exchanger (121). The temp door (122) closes the hot air passage passing through the electric heater (123).

[0068] Referring to Fig. 8, in the battery cooling mode (Only Battery Cooling Mode), the high temperature and high pressure refrigerant discharged from the compressor (101) passes through the outdoor heat exchanger (102) via the directional valve (110), exchanges heat with the outdoor air, and then expands in the expansion valve (200). The refrigerant expanded in the expansion valve (200) passes through the chiller refrigerant line (192) to the chiller (104), cools the cooling water circulating in the battery, and then passes through the accumulator (105) to circulate in the compressor (101). In this case, the third communication port (230) of the expansion valve (200) is closed, and the refrigerant does not flow to the indoor heat exchanger (121). The temp door (122) closes the hot air passage passing through the electric heater (123).

[0069] Referring to Fig. 9, in the dehumidification and heating mode, the high temperature and high pressure refrigerant discharged from the compressor (101) passes through the outdoor heat exchanger (102) via the directional change valve (110), exchanges heat with the outdoor air, and then is expanded in the expansion valve (200). The refrigerant expanded in the expansion valve (200) passes through the indoor heat exchanger (121), passes through the directional change valve (110), passes through the accumulator (105), and circulates through the compressor (101). The refrigerant passing through the indoor heat exchanger (121) exchanges heat with the air blown into the vehicle interior, thereby performing dehumidification.

[0070] In addition, the vehicle interior is heated by heating the air passing through the electric heater (123) by operating the electric heater (123). In this case, the second combustion port (220) of the expansion valve (200) is closed and the refrigerant does not flow to the chiller (104). The temp door (122) opens the hot air passage passing through the electric heater (123).

[0071] As shown in FIGS. 6 to 9, when the refrigerant discharged from the compressor (101) flows to the outdoor heat exchanger (102) through the direction change valve (110), the upper side and the left side of the direction change valve (110) in the drawing are indicated with black shading.

[0072] Referring to Fig. 10, in the first heating mode (outside air and electric field waste heat absorption), the high temperature and high pressure refrigerant discharged from the compressor (101) passes through the indoor heat exchanger (121) via the direction change valve (110). The refrigerant passing through the indoor heat exchanger (121) exchanges heat with the air blown into the vehicle interior, thereby performing heating.

[0073] The refrigerant that has passed through the indoor heat exchanger (121) is expanded in the expansion valve (200), and then some of it passes through the chiller (104) and the accumulator (105) via the chiller refrigerant line (192) and circulates through the compressor (101). Another part of the refrigerant expanded in the expansion valve (200) passes through the outdoor heat exchanger (102), the directional change valve (110), the accumulator (105), and circulates through the compressor (101). The refrigerant absorbs the waste heat of the entire system in the chiller (104) and the outside air in the outdoor heat exchanger (102).

[0074] In this case, the expanded refrigerant is discharged through both the first communication port (210) and the second communication port (220) of the expansion valve (200). That is, the refrigerant flowing into the third communication port (230) of the expansion valve (200) expands, and some of it flows out through the second communication port (220) to the chiller (104), and the other part flows out through the first communication port (210) to the outdoor heat exchanger (102). The temp door (122) opens the hot air passage passing through the electric heater (123).

[0075] Referring to Fig. 11, in the second heating mode (outside air heat absorption), the high temperature and high pressure refrigerant discharged from the compressor (101) passes through the indoor heat exchanger (121) via the direction change valve (110). The refrigerant passing through the indoor heat exchanger (121) exchanges heat with the air blown into the vehicle interior, thereby performing heating.

[0076] The refrigerant passing through the indoor heat exchanger (121) expands in the expansion valve (200), then passes through the outdoor heat exchanger (102), the directional change valve (110), the accumulator (105), and circulates through the compressor (101). The refrigerant absorbs heat from the outside air in the outdoor heat exchanger (102). In this case, the second communication port (220) of the expansion valve (200) is closed, and the refrigerant does not flow to the chiller (104). The temp door (122) opens the hot air passage passing through the electric heater (123). This mode can be used in environments such as when the waste heat of the entire vehicle is not sufficient at the beginning of the vehicle startup.

[0077] Referring to Fig. 12, in the third heating mode (waste heat absorption), the high temperature and high pressure refrigerant discharged from the compressor (101) passes through the indoor heat exchanger (121) via the direction change valve (110). The refrigerant passing through the indoor heat exchanger (121) exchanges heat with the air blown into the vehicle interior, thereby performing heating.

[0078] The refrigerant passing through the indoor heat exchanger (121) expands in the expansion valve (200) and then circulates through the chiller (104) and the accumulator (105) via the chiller refrigerant line (192) and the compressor (101). In this case, the first communication port (210) of the expansion valve (200) is closed and the refrigerant does not flow to the outdoor heat exchanger (102). The temp door (122) opens the hot air passage passing through the electric heater (123). This mode can be used in environments where the outside temperature is extremely low.

[0079] As shown in FIGS. 10 to 12, when the refrigerant discharged from the compressor (101) flows to the indoor heat exchanger (121) through the directional change valve (110), the upper side and the right side of the directional change valve (110) in the drawing are indicated with black shading.

[0080]

[0081] While the vehicle heat pump system according to the present invention has been described with reference to the embodiments illustrated in the drawings, these are merely exemplary, and anyone skilled in the art will understand that various modifications and equivalent alternative embodiments are possible. Therefore, the true scope of technical protection should be determined by the technical spirit of the appended claims.

Claims

1. A compressor that compresses and discharges refrigerant; An indoor heat exchanger installed inside the air conditioning case to exchange heat with the air discharged into the vehicle interior; An outdoor heat exchanger installed outside the air conditioning case to exchange heat with the outside air; An expansion valve that controls the flow direction of the refrigerant and can optionally expand the refrigerant; A chiller that exchanges heat between refrigerant and cooling water; and It has a directional valve that controls the flow of the refrigerant discharged from the compressor to selectively flow to an outdoor heat exchanger or an indoor heat exchanger, A vehicle heat pump system wherein the expansion valve includes a plurality of communication ports, and at least two of the plurality of communication ports are configured to be changed to an inlet or an outlet of a refrigerant depending on the mode.

2. In paragraph 1, A vehicle heat pump system characterized in that the above expansion valve can be introduced into one opening and expanded and discharged through openings in different directions depending on the mode.

3. In paragraph 1, The above expansion valve, A vehicle heat pump system that selectively expands and sends refrigerant that has passed through an outdoor heat exchanger to an indoor heat exchanger or chiller, or selectively expands and sends refrigerant that has passed through an indoor heat exchanger to an outdoor heat exchanger or chiller.

4. In paragraph 3, The above expansion valve, A vehicle heat pump system having a first communication port connected to an outdoor heat exchanger, a second communication port connected to a chiller, and a third communication port connected to an indoor heat exchanger, wherein refrigerant is introduced into the first communication port and the refrigerant is expanded and sent to the second or third communication port, or refrigerant is introduced into the third communication port and the refrigerant is expanded and sent to the first or second communication port.

5. In paragraph 4, The above directional change valve is a vehicle heat pump system consisting of a 4-way valve each connected to a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a refrigerant line between the chiller and the compressor.

6. In paragraph 5, A chiller refrigerant line is provided that branches from the refrigerant line between the outdoor heat exchanger and the indoor heat exchanger and is connected to the chiller. A vehicle heat pump system, characterized in that the expansion valve is provided at a branch point of the chiller refrigerant line.

7. In paragraph 6, A vehicle heat pump system further comprising a connecting pipe formed on the downstream side of the directional valve in the direction of refrigerant flow so that refrigerant passing through the directional valve can flow to the compressor.

8. In paragraph 6, In cooling mode, A vehicle heat pump system characterized in that the refrigerant discharged from the compressor passes through the outdoor heat exchanger via the directional valve, expands in the expansion valve, passes through the indoor heat exchanger, and circulates through the compressor, and in this case, the second communication port of the expansion valve is closed.

9. In paragraph 6, In cooling and battery cooling mode, A vehicle heat pump system characterized in that the refrigerant discharged from the compressor passes through the outdoor heat exchanger via the directional valve, expands in the expansion valve, and then some of it passes through the indoor heat exchanger and circulates through the compressor, while another part passes through the chiller via the chiller refrigerant line and circulates through the compressor, and in this case, the expanded refrigerant is discharged through both the second and third communication ports of the expansion valve.

10. In paragraph 6, In battery cooling mode, A vehicle heat pump system characterized in that the refrigerant discharged from the compressor passes through a direction change valve, passes through an outdoor heat exchanger, is expanded in an expansion valve, passes through a chiller, and circulates through the compressor, and in this case, the third communication port of the expansion valve is closed.

11. In paragraph 6, In dehumidifying heating mode, The refrigerant discharged from the compressor passes through the outdoor heat exchanger via the directional valve, expands in the expansion valve, and then passes through the indoor heat exchanger to circulate through the compressor. In this case, the second communication port of the expansion valve is closed. A vehicle heat pump system characterized in that it performs heating by heating air through the operation of an electric heater provided downstream of an indoor heat exchanger in the direction of air flow.

12. In paragraph 6, In the first heating mode, A vehicle heat pump system characterized in that the refrigerant discharged from the compressor passes through the indoor heat exchanger via the directional valve, is expanded by the expansion valve, and then some of it passes through the outdoor heat exchanger and circulates through the compressor, and another part passes through the chiller via the chiller refrigerant line and circulates through the compressor, and in this case, the expanded refrigerant is discharged through both the first and second communication ports of the expansion valve.

13. In paragraph 6, In the second heating mode, A vehicle heat pump system characterized in that the refrigerant discharged from the compressor passes through the indoor heat exchanger via the directional valve, is expanded in the expansion valve, passes through the outdoor heat exchanger, and circulates through the compressor, and in this case, the second communication port of the expansion valve is closed.

14. In paragraph 6, In the third heating mode, A vehicle heat pump system characterized in that the refrigerant discharged from the compressor passes through the indoor heat exchanger via the directional valve, expands in the expansion valve, passes through the chiller, and circulates through the compressor, and in this case, the first communication port of the expansion valve is closed.

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