Heat pump system for vehicle

Abstract

Disclosed is a heat pump system for a vehicle, which can implement all of cooling, heating, and dehumidifying functions while enabling reduction of a package of an air conditioning device, and uses only three refrigerant valves and can thus improve price competitiveness. The heat pump system for a vehicle comprises: a compressor for compressing and discharging a refrigerant; an indoor heat exchanger provided inside an air conditioning case to exchange heat with air discharged into the interior of a vehicle; an outdoor heat exchanger provided outside the air conditioning case to exchange heat with external air; a chiller for performing heat exchange between a refrigerant and cooling water; a direction switching valve for controlling the flow of the refrigerant discharged from the compressor so that the refrigerant selectively flows to the outdoor heat exchanger or the indoor heat exchanger; a first expansion valve capable of controlling the flow direction of a refrigerant and selectively expanding the refrigerant; and a second expansion valve disposed at a different position from the first expansion valve to be able to control the flow direction of a refrigerant and selectively expand the refrigerant, wherein the first expansion valve and the second expansion valve are configured to be able to be in a fully closed state for blocking the flow of a refrigerant.

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 three 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; a chiller for exchanging heat between a refrigerant and a cooling water; a directional valve for controlling the flow of the refrigerant discharged from the compressor so that it can selectively flow to the outdoor heat exchanger or the indoor heat exchanger; a first expansion valve for controlling the flow direction of the refrigerant and selectively expanding the refrigerant; and a second expansion valve for controlling the flow direction of the refrigerant and selectively expanding the refrigerant, the first expansion valve and the second expansion valve being arranged at a different position from the first expansion valve and configured to be in a fully closed state (Full Close) that blocks the flow of the refrigerant.

[0017] An expansion valve connection line connecting the first expansion valve and the second expansion valve is further provided.

[0018] The refrigerant passing through the second expansion valve can move to the first expansion valve via the expansion valve connection line, and the refrigerant expands in at least one of the first expansion valve and the second expansion valve depending on the air conditioning mode.

[0019] The first expansion valve is configured as a three-way valve connected to a refrigerant line between the outdoor heat exchanger and the second expansion valve, a chiller, and the second expansion valve, respectively, and the second expansion valve is configured as a three-way valve connected to the first expansion valve, the indoor heat exchanger, and the outdoor heat exchanger, respectively.

[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] The first expansion valve is configured to expand the refrigerant that has passed through the outdoor heat exchanger and flow to the chiller, or to expand the refrigerant that has passed through the second expansion valve and flow to the chiller, and the second expansion valve is configured to expand the refrigerant that has passed through the outdoor heat exchanger and flow to the indoor heat exchanger, or to expand the refrigerant that has passed through the indoor heat exchanger and flow to the outdoor heat exchanger, or to expand the refrigerant that has passed through the indoor heat exchanger and flow to the first expansion valve.

[0022] A chiller refrigerant line is provided that branches from the refrigerant line between the outdoor heat exchanger and the second expansion valve and is connected to the chiller, and the first expansion valve is provided in the chiller refrigerant line.

[0023] A first connecting pipe that allows the refrigerant that has passed through the outdoor heat exchanger to flow to the first expansion valve or the second expansion valve; and a second connecting pipe that is formed on the downstream side of the directional switching valve in the refrigerant flow direction so that the refrigerant that has passed through the directional switching valve can flow to the compressor are further provided.

[0024] In cooling mode, the refrigerant discharged from the compressor passes through the outdoor heat exchanger via the direction change valve, expands in the second expansion valve, passes through the indoor heat exchanger, and circulates through the compressor. In this case, the first expansion valve is fully closed (Full Close).

[0025] In cooling and battery cooling mode, the refrigerant discharged from the compressor passes through the direction change valve to the outdoor heat exchanger, some of which is expanded in the second expansion valve and then passes through the indoor heat exchanger to circulate through the compressor, and the other part is expanded in the first expansion valve through the chiller refrigerant line and then passes through the chiller to circulate through the compressor.

[0026] In battery cooling mode, the refrigerant discharged from the compressor passes through the outdoor heat exchanger via the direction change valve, expands in the first expansion valve through the chiller refrigerant line, and then circulates through the compressor via the chiller. In this case, the second expansion valve is fully closed (Full Close).

[0027] 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 second expansion valve, passes through the indoor heat exchanger, and circulates through the compressor. In this case, the first expansion valve is fully closed (Full Close), 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.

[0028] In the first heating mode, the refrigerant discharged from the compressor passes through the indoor heat exchanger via the direction change valve, expands in the second expansion valve, and then some of it passes through the first expansion valve via the chiller refrigerant line, passes through the chiller, and circulates through the compressor, while the other part passes through the outdoor heat exchanger and circulates through the compressor.

[0029] In the second heating mode, the refrigerant discharged from the compressor passes through the indoor heat exchanger via the direction change valve, expands in the second expansion valve, and then passes through the outdoor heat exchanger and circulates through the compressor. In this case, the first expansion valve is fully closed (Full Close).

[0030] In the third heating mode, the refrigerant discharged from the compressor passes through the indoor heat exchanger via the direction change valve, passes through the second expansion valve as is, and flows to the first expansion valve via the expansion valve connection line. After the refrigerant is expanded in the first expansion valve, it passes through the chiller and circulates through the compressor.

[0031] In the fourth heating mode, the refrigerant discharged from the compressor passes through the indoor heat exchanger via the direction change valve, expands in the second expansion valve, and then flows to the first expansion valve via the expansion valve connection line. After the refrigerant passes through the first expansion valve as is, it passes through the chiller and circulates through the compressor.

[0032] 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.

[0033] Furthermore, by configuring the refrigerant with three valves (one directional valve and two expansion valves), the system can implement various air conditioning modes, including cooling, heating, dehumidification, and battery cooling, thereby reducing manufacturing costs and enhancing price competitiveness. Meanwhile, the expansion valve connection line can selectively expand the refrigerant through one of the two expansion valves during heating mode, maximizing heating efficiency.

[0034] Figure 1 illustrates a conventional vehicle heat pump system.

[0035] FIG. 2 illustrates a vehicle heat pump system according to one embodiment of the present invention.

[0036] FIG. 3 illustrates a direction change valve of a vehicle heat pump system according to one embodiment of the present invention.

[0037] FIG. 4 illustrates a first expansion valve of a vehicle heat pump system according to one embodiment of the present invention.

[0038] FIG. 5 illustrates a second expansion valve of a vehicle heat pump system according to one embodiment of the present invention.

[0039] FIG. 6 is a drawing for explaining the operation mode of the first expansion valve and the second expansion valve according to one embodiment of the present invention.

[0040] FIG. 7 illustrates a cooling mode of a vehicle heat pump system according to one embodiment of the present invention.

[0041] FIG. 8 illustrates the cooling and battery cooling modes of a vehicle heat pump system according to one embodiment of the present invention.

[0042] FIG. 9 illustrates a battery cooling mode of a vehicle heat pump system according to an embodiment of the present invention.

[0043] FIG. 10 illustrates a dehumidifying heating mode of a vehicle heat pump system according to an embodiment of the present invention.

[0044] FIG. 11 illustrates a first heating mode of a vehicle heat pump system according to one embodiment of the present invention.

[0045] FIG. 12 illustrates a second heating mode of a vehicle heat pump system according to an embodiment of the present invention.

[0046] FIG. 13 illustrates a third heating mode of a vehicle heat pump system according to an embodiment of the present invention.

[0047] FIG. 14 illustrates a fourth heating mode of a vehicle heat pump system according to one embodiment of the present invention.

[0048] The technical configuration of a vehicle heat pump system is described in detail according to the attached drawings as follows.

[0049] Referring to FIGS. 2 to 6, 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 means, and an indoor heat exchanger (121).

[0050] 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.

[0051] 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.

[0052] The compressor (101) sucks in refrigerant, compresses it, and then discharges it in a high-temperature, high-pressure gaseous state. 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.

[0053] 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 second expansion valve (300) and the refrigerant in the refrigerant line (191) connecting the accumulator (105) and the compressor (101).

[0054] 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 means expands the refrigerant. The chiller (104) is a refrigerant-coolant heat exchanger that exchanges heat between the refrigerant and the coolant circulating in the vehicle's electrical components or batteries.

[0055] 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.

[0056] 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.

[0057] A vehicle heat pump system according to one embodiment of the present invention comprises a chiller refrigerant line (192) and an expansion valve connection line (193). In addition, the vehicle heat pump system further comprises a direction change valve (110). In addition, the expansion means comprises a first expansion valve (200) and a second expansion valve (300).

[0058] The chiller refrigerant line (192) branches from the refrigerant line between the outdoor heat exchanger (102) and the second expansion valve (300) and is connected to the chiller (104). The expansion valve connection line (193) connects the first expansion valve (200) and the second expansion valve (300).

[0059] The refrigerant passing through the second expansion valve (300) can move to the first expansion valve (200) via the expansion valve connection line (193). In this case, the refrigerant expands in at least one of the first expansion valve (200) and the second expansion valve (300) depending on the air conditioning mode. The expansion valve connection line (193) can maximize heating efficiency by selectively expanding the refrigerant in one of the first expansion valve (200) and the second expansion valve (300) in the heating mode. This will be described in detail later.

[0060] 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).

[0061] The first expansion valve (200) is configured to control the flow direction of the refrigerant and to selectively expand the refrigerant. That is, the first expansion valve (200) is configured as an electric expansion valve (EXV). In addition, the first expansion valve (200) is configured as a 3-way valve. The first expansion valve (200) is connected to the refrigerant line between the outdoor heat exchanger (102) and the second expansion valve (300), the chiller (104), and the second expansion valve (300), respectively.

[0062] The first expansion valve (200) is provided in the chiller refrigerant line (192). The first expansion valve (200) not only performs the function of expanding the refrigerant but also performs the function of changing the direction of the flow of the refrigerant, and can change the inlet and outlet during the expansion of the refrigerant. In other words, the first expansion valve (200) has three communication ports that selectively function as the inlet or outlet of the refrigerant depending on the air conditioning mode.

[0063] More specifically, the first expansion valve (200) can introduce refrigerant through a communication port connected to the refrigerant line between the outdoor heat exchanger (102) and the second expansion valve (300) among the three communication ports, expand the refrigerant, and then discharge the refrigerant through a communication port connected to the chiller (104). In addition, the first expansion valve (200) can introduce refrigerant through a communication port connected to the second expansion valve (300) among the three communication ports, expand the refrigerant, and then discharge the refrigerant through a communication port connected to the chiller (104).

[0064] In addition, the first expansion valve (200) is configured to be in a fully closed state (Full Close) that completely blocks the flow of refrigerant. When fully closed, the first expansion valve (200) closes all three communication ports, so that the refrigerant does not flow to the first expansion valve (200). Meanwhile, the first expansion valve (200) is capable of being fully opened in one direction (Full Open), so that the refrigerant can pass through without being expanded.

[0065] The second expansion valve (300) is arranged at a different position from the first expansion valve (200) to control the flow direction of the refrigerant and to selectively expand the refrigerant. That is, the second expansion valve (300) is configured as an electric expansion valve (EXV). In addition, the second expansion valve (300) is configured as a 3-way valve. The second expansion valve (300) is connected to the first expansion valve (200), the indoor heat exchanger (121), and the outdoor heat exchanger (102), respectively.

[0066] The second expansion valve (300) has the same structure as the first expansion valve (200). That is, the second expansion valve (300) performs not only the expansion function of the refrigerant but also the direction-changing function of changing the flow of the refrigerant, and can change the inlet and outlet during the expansion of the refrigerant. That is, the second expansion valve (300) has three communication ports that selectively function as the inlet or outlet of the refrigerant depending on the air conditioning mode.

[0067] More specifically, the second expansion valve (300) can introduce refrigerant through a communication port connected to the outdoor heat exchanger (102) among the three communication ports, expand the refrigerant, and then discharge the refrigerant through a communication port connected to the indoor heat exchanger (121). In addition, the second expansion valve (300) can introduce refrigerant through a communication port connected to the indoor heat exchanger (121) among the three communication ports, expand the refrigerant, and then discharge the refrigerant through a communication port connected to the outdoor heat exchanger (102). In addition, the second expansion valve (300) can introduce refrigerant through a communication port connected to the indoor heat exchanger (121) among the three communication ports, expand the refrigerant, and then discharge the refrigerant through a communication port connected to the first expansion valve (200).

[0068] In addition, the second expansion valve (300) is configured to be in a fully closed state (Full Close) that completely blocks the flow of refrigerant. When fully closed, the second expansion valve (300) closes all three communication ports, so that the refrigerant does not flow to the second expansion valve (300). Meanwhile, the second expansion valve (300) is capable of being fully opened in one direction (Full Open), so that the refrigerant can pass through without being expanded.

[0069] The first expansion valve (200) expands the refrigerant that has passed through the outdoor heat exchanger (102) and causes it to flow to the chiller (104), or expands the refrigerant that has passed through the second expansion valve (300) and causes it to flow to the chiller (104). In addition, the second expansion valve (300) expands the refrigerant that has passed through the outdoor heat exchanger (102) and causes it to flow to the indoor heat exchanger (121), or expands the refrigerant that has passed through the indoor heat exchanger (121) and causes it to flow to the outdoor heat exchanger (102), or expands the refrigerant that has passed through the indoor heat exchanger (121) and causes it to flow to the first expansion valve (200).

[0070] As illustrated in Fig. 6, the first expansion valve (200) and the second expansion valve (300) are not 3-way valves that simply change direction, nor are they throttle means that perform one-way expansion, but are three-way valves that can expand in multiple directions. That is, the three-way valve according to the present invention may be in a state where all three communication ports are closed (Full Close), or the first communication port is closed and the second communication port and the third communication port are in communication (Open 1), or the third communication port is closed and the first communication port and the second communication port are in communication (Open 2), or the first communication port is closed and the refrigerant flows into the second communication port, expands, and then flows into the third communication port (Expansion 1), or the first communication port is closed and the refrigerant flows into the third communication port, expands, and then flows into the second communication port (Expansion 1), or the third communication port is closed and the refrigerant flows into the first communication port, expands, and then flows into the second communication port (Expansion 2), or the third communication port is closed and the refrigerant flows into the second communication port, expands, and then flows into the first communication port (Expansion 2). In this way, the expansion inlet and outlet of the first expansion valve (200) and the second expansion valve (300) are configured to be changeable.

[0071] Meanwhile, the vehicle heat pump system further comprises a first connecting pipe (161) and a second connecting pipe (162). The first connecting pipe (161) allows the refrigerant passing through the outdoor heat exchanger (102) to flow to the first expansion valve (200) or the second expansion valve (300). That is, the refrigerant flowing into the first connecting pipe (161) selectively flows to the first expansion valve (200) or to the second expansion valve (300) through the double pipe (103). The second connecting pipe (162) is formed downstream of the directional change valve in the refrigerant flow direction so that the refrigerant passing through the directional change valve (110) can flow to the compressor (101). That is, the refrigerant that has passed through the direction change valve (110) passes through the second connecting pipe (162), passes through the accumulator (105), and then flows to the compressor (101).

[0072] 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, a variety of air conditioning modes can be implemented using a single directional switching valve (4-way valve) and two expansion valves (3-way valves). In particular, both expansion valves are configured to have changeable expansion inlets and outlets.

[0073] Through this configuration, the overall package of the air conditioning device can be reduced by applying only one heat exchanger within the air conditioning case (120). In addition, by configuring the refrigerant valves with three (one directional valve and two expansion valves), various air conditioning modes such as cooling, heating, dehumidification, and battery cooling can be implemented, thereby reducing manufacturing costs and increasing price competitiveness. Meanwhile, the expansion valve connection line can maximize heating efficiency by selectively expanding the refrigerant in one of the two expansion valves during heating mode.

[0074] Referring to Fig. 7, 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 second expansion valve (300), 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 cooling. In this case, the first expansion valve (200) is fully closed (Full Close), and the refrigerant does not flow to the chiller (104). The temp door (122) closes the hot air passage passing through the electric heater (123).

[0075] Referring to Fig. 8, in the cooling and battery cooling mode (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, then flows into the first connecting pipe (161), and some of it is expanded in the second expansion valve (300), 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.

[0076] Another portion of the refrigerant that has passed through the outdoor heat exchanger (102), exchanged heat with the outdoor air, and then flowed into the first connecting pipe (161) is expanded in the first expansion valve (200) through the chiller refrigerant line (192), and then passes through the chiller (104) to cool the coolant circulating in the battery, and then passes through the accumulator (105) and circulates through the compressor (101). That is, the refrigerant that has passed through the directional change valve (110) flows into the second connecting pipe (162) and flows into the accumulator (105). In this case, both the first expansion valve (200) and the second expansion valve (300) perform one-way expansion, so that the expanded refrigerant is supplied to the chiller (104) and the indoor heat exchanger (121), respectively. The temp door (122) closes the hot air passage passing through the electric heater (123).

[0077] Referring to Fig. 9, in the battery cooling mode (Only Battery Cooling Mode), the high temperature and high pressure refrigerant discharged from the compressor (101) passes through the direction changing valve (110) to the outdoor heat exchanger (102) and exchanges heat with the outdoor air, then expands in the first expansion valve (200) through the chiller refrigerant line (192), passes through the chiller (104), cools the cooling water circulating in the battery, and then passes through the accumulator (105) and circulates through the compressor (101). In this case, the second expansion valve (300) is completely 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).

[0078] Referring to Fig. 10, 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) and exchanges heat with the outdoor air, then expands in the second expansion valve (300), 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).

[0079] The refrigerant passing through the indoor heat exchanger (121) exchanges heat with the air blown into the vehicle interior, thereby performing dehumidification. In addition, the electric heater (123) is operated to heat the air passing through the electric heater (123), thereby heating the vehicle interior. In this case, the first expansion valve (200) is fully closed (Full Close), 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).

[0080] As shown in FIGS. 7 to 10, 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.

[0081] Referring to Fig. 11, 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.

[0082] The refrigerant that has passed through the indoor heat exchanger (121) is expanded in the second expansion valve (300), and then some of it passes through the chiller refrigerant line (192) and the first expansion valve (200) as is, passes through the chiller (104) and the accumulator (105), and circulates through the compressor (101). Another part of the refrigerant expanded in the second expansion valve (300) passes through the outdoor heat exchanger (102), passes through the direction change valve (110), passes through the accumulator (105), and circulates through the compressor (101). The refrigerant absorbs the waste heat of the entire system in the chiller (104) and absorbs the outside air in the outdoor heat exchanger (102).

[0083] Referring to Fig. 12, 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.

[0084] The refrigerant passing through the indoor heat exchanger (121) expands in the second expansion valve (300), 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 first expansion valve (200) is fully closed (Full Close), and the refrigerant does not flow to the chiller (104). This mode can be used in environments such as when the waste heat from the entire vehicle is insufficient at the beginning of the vehicle startup.

[0085] Referring to Fig. 13, in the third heating mode (full-range waste heat absorption, first expansion valve expansion), 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.

[0086] The refrigerant that has passed through the indoor heat exchanger (121) passes through the second expansion valve (300) as is and flows to the first expansion valve (200) through the expansion valve connection line (193). After the refrigerant is expanded in the first expansion valve (200), it passes through the chiller (104) and the accumulator (105) and circulates through the compressor (101). In this case, the first expansion valve (200) performs one-way expansion so that the expanded refrigerant is supplied to the chiller (104), and the second expansion valve (300) passes the refrigerant as is without expanding it.

[0087] Referring to Fig. 14, in the fourth heating mode (full-range waste heat absorption, second expansion valve expansion), 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.

[0088] The refrigerant that has passed through the indoor heat exchanger (121) is expanded in the second expansion valve (300) and then flows to the first expansion valve (200) through the expansion valve connection line (193). The refrigerant passes through the first expansion valve (200) as is, then passes through the chiller (104) and the accumulator (105) and circulates through the compressor (101). In this case, the first expansion valve (200) passes the refrigerant through without expanding it, and the second expansion valve (300) performs one-way expansion so that the expanded refrigerant is supplied to the first expansion valve (200).

[0089] In this way, the inlet and outlet of the refrigerant are changed in both directions, and bidirectional expansion is possible. Through the configuration of the expansion valve connection line (193) connecting the first expansion valve (200) and the second expansion valve (300), the refrigerant that has passed through the indoor heat exchanger (121) can be expanded in the second expansion valve (300) rather than the first expansion valve (200).

[0090] The third heating mode in which expansion occurs in the first expansion valve (200) can further maximize heating efficiency compared to the fourth heating mode structure in which expansion occurs in the second expansion valve (300). This is because, in addition to the indoor heat exchanger (121), more high-temperature refrigerant exists in the expansion valve connection line (193) between the first expansion valve (200) and the second expansion valve (300), so that when the performance is the same, the pressure of the overall heat pump system is lowered and the power consumption of the compressor (101) is lowered, so the structure in which expansion occurs in the first expansion valve (200) has better heating efficiency.

[0091] As shown in FIGS. 11 to 14, 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.

[0092]

[0093] 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; A chiller that exchanges heat between refrigerant and cooling water; A directional valve that controls the flow of refrigerant discharged from the compressor to selectively flow to an outdoor heat exchanger or an indoor heat exchanger; A first expansion valve capable of controlling the flow direction of the refrigerant and selectively expanding the refrigerant; and A second expansion valve is disposed at a different location from the first expansion valve to control the flow direction of the refrigerant and optionally expand the refrigerant. A vehicle heat pump system in which the first expansion valve and the second expansion valve are configured to be in a fully closed state that blocks the flow of refrigerant.

2. In paragraph 1, A vehicle heat pump system further comprising an expansion valve connection line connecting the first expansion valve and the second expansion valve.

3. In paragraph 2, A vehicle heat pump system characterized in that the refrigerant passing through the second expansion valve can move to the first expansion valve through the expansion valve connection line, and the refrigerant expands in at least one of the first expansion valve and the second expansion valve depending on the air conditioning mode.

4. In paragraph 2, The above first expansion valve is composed of a three-way valve connected to the refrigerant line between the outdoor heat exchanger and the second expansion valve, the chiller, and the second expansion valve, respectively. A vehicle heat pump system characterized in that the second expansion valve is composed of a three-way valve connected to the first expansion valve, the indoor heat exchanger, and the outdoor heat exchanger, respectively.

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 4, The above first expansion valve is configured to expand the refrigerant that has passed through the outdoor heat exchanger and flow to the chiller, or to expand the refrigerant that has passed through the second expansion valve and flow to the chiller. A vehicle heat pump system in which the second expansion valve expands the refrigerant that has passed through the outdoor heat exchanger and causes it to flow to the indoor heat exchanger, or expands the refrigerant that has passed through the indoor heat exchanger and causes it to flow to the outdoor heat exchanger, or expands the refrigerant that has passed through the indoor heat exchanger and causes it to flow to the first expansion valve.

7. In paragraph 5, A chiller refrigerant line is provided that branches from the refrigerant line between the above outdoor heat exchanger and the second expansion valve and is connected to the chiller. A vehicle heat pump system, characterized in that the first expansion valve is provided in the chiller refrigerant line.

8. In paragraph 7, A first connecting pipe that allows the refrigerant passing through the outdoor heat exchanger to flow to the first expansion valve or the second expansion valve; and A vehicle heat pump system further comprising a second 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.

9. In paragraph 7, 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 direction change valve, is expanded in the second expansion valve, passes through the indoor heat exchanger, and circulates through the compressor, and in this case, the first expansion valve is fully closed (Full Close).

10. In paragraph 7, In cooling and battery cooling mode, A vehicle heat pump system characterized in that the refrigerant discharged from the compressor passes through a direction change valve to an outdoor heat exchanger, some of which is expanded in a second expansion valve and then passes through an indoor heat exchanger to circulate through the compressor, and the other part is expanded in a first expansion valve through a chiller refrigerant line and then passes through a chiller to circulate through the compressor.

11. In paragraph 7, In 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 direction change valve, expands in the first expansion valve through the chiller refrigerant line, passes through the chiller, and circulates through the compressor, and in this case, the second expansion valve is fully closed.

12. In paragraph 7, In dehumidifying heating mode, The refrigerant discharged from the compressor passes through the outdoor heat exchanger via the directional valve, expands in the second expansion valve, passes through the indoor heat exchanger, and circulates through the compressor. In this case, the first expansion valve is fully closed (Full Close). 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.

13. In paragraph 7, 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 direction change valve, expands in the second expansion valve, and then some of it passes through the first expansion valve via the chiller refrigerant line and circulates through the compressor, while the other part passes through the outdoor heat exchanger and circulates through the compressor.

14. In paragraph 7, 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 change valve, is expanded in the second expansion valve, passes through the outdoor heat exchanger, and circulates through the compressor, and in this case, the first expansion valve is fully closed (Full Close).

15. In paragraph 7, 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 direction change valve, passes through the second expansion valve as is, flows to the first expansion valve via the expansion valve connection line, and after the refrigerant is expanded in the first expansion valve, passes through the chiller and circulates through the compressor.

16. In paragraph 7, In the 4th 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 second expansion valve, flows to the first expansion valve via the expansion valve connection line, and then passes through the chiller and circulates through the compressor as is from the first expansion valve.

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