Vehicle HVAC system

Abstract

The HVAC system of the present invention includes a compressor; an internal condenser provided on the downstream side of the compressor; a refrigerant heat exchanger between the internal condenser and the compressor, the refrigerant heat exchanger configured to transfer heat between an expanded refrigerant and an unexpanded refrigerant among the refrigerants discharged from the internal condenser; a water-cooled heat exchanger disposed on a downstream side of the internal condenser and configured to transfer heat between the refrigerant and the coolant circulating in the coolant system; an external heat exchanger disposed on a downstream side of the internal condenser and configured to transfer heat between the refrigerant and ambient air; and a control valve unit configured to control flow of the refrigerant and expansion and / or non-expansion of the refrigerant among the internal condenser, the water-cooled heat exchanger, the external heat exchanger, and the refrigerant heat exchanger.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Korean Patent Application No. 10-2023-0154827, filed on November 9, 2023, which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a vehicle heating, ventilation and air conditioning (HVAC) system. Background Art

[0004] With the increasing attention paid to energy efficiency and environmental issues, there is a need to develop environmentally friendly vehicles that can replace internal combustion engine vehicles. Such environmentally friendly vehicles are divided into electric vehicles driven by using fuel cells or electricity as a power source, and hybrid vehicles driven by using an engine and a battery.

[0005] An electric vehicle or hybrid vehicle may include a heating, ventilation, and air conditioning (HVAC) system for air conditioning in the vehicle cabin (or passenger compartment). The HVAC system may be configured to heat and cool the air within the vehicle cabin for passenger comfort.

[0006] To ensure driving safety, an electric vehicle or hybrid vehicle may include a power electronics (PE) cooling system designed to maintain the PE components of the PE system at an appropriate temperature and a battery cooling system designed to maintain the battery at an appropriate temperature. The PE cooling system may cool PE components such as a motor, an inverter, an on-board charger (OBC), and a low DC-DC converter (LDC), thereby maintaining the PE components at their respective appropriate temperatures. The battery cooling system may cool the battery, thereby maintaining the battery at its appropriate temperature.

[0007] The HVAC system and the PE cooling system may be thermally connected via a water-cooled heat exchanger. When the HVAC system is operated in a heating mode, the refrigerant may absorb heat from the PE coolant circulating in the PE cooling system via the water-cooled heat exchanger. That is, the refrigerant may be configured to absorb waste heat from the PE components via the water-cooled heat exchanger.

[0008] When the HVAC system is operated in a heating mode, the refrigerant compressed by the compressor may be condensed by the interior condenser, and the refrigerant may heat the air passing through the outer surface of the interior condenser, so that the heating of the vehicle cabin may be performed. The refrigerant exhausted from the interior condenser may be expanded by the expansion valve, and the expanded refrigerant may be evaporated by the water-cooled heat exchanger.

[0009] When the HVAC system operates in the heating and dehumidification mode, the refrigerant compressed by the compressor may be condensed by the interior condenser, and the refrigerant may heat the air passing through the outer surface of the interior condenser, so that heating of the cabin may be performed. The refrigerant exhausted from the interior condenser may be expanded by the expansion valve. A portion of the expanded refrigerant may be evaporated by the water-cooled heat exchanger, the remaining portion of the expanded refrigerant may be evaporated by the evaporator, and the air passing through the outer surface of the evaporator may be cooled, so that dehumidification of the cabin may be performed.

[0010] However, in the HVAC system according to the related art, when the refrigerant fails to sufficiently absorb heat through the water-cooled heat exchanger, the evaporation amount of the refrigerant may decrease, and thus the suction pressure of the compressor may decrease below the threshold pressure. When the suction pressure of the compressor is lower than the threshold pressure, the efficiency of the compressor may decrease, and thus the RPM of the compressor may decrease below the threshold RPM or the compressor may stop. Therefore, the coefficient of performance (COP) of the HVAC system may decrease. Since the heating of the cabin is not performed using the refrigerant, but the cabin is heated only by the electric heater of the HVAC system, the electrical efficiency of the electric vehicle may decrease.

[0011] In the HVAC system of the related art, as the heat absorption of the refrigerant decreases, the evaporation amount of the refrigerant may be insufficient. Therefore, due to the reduction or stop of the RPM of the compressor, the heating and dehumidification of the cabin using the refrigerant may not be performed smoothly, and the heating of the cabin may be performed by the electric heater, so that the electrical efficiency of the electric vehicle may be reduced.

[0012] The above information described in this background section is for helping understanding the background of the present invention concepts and may include various technical concepts that are not considered to be prior art known to the public. Summary of the invention

[0013] The present invention relates to a vehicle heating, ventilation and air conditioning (HVAC) system. A particular embodiment relates to a vehicle HVAC system designed to improve heating performance and / or dehumidification performance using refrigerant by using a control valve unit and a refrigerant heat exchanger disposed between a compressor and an interior condenser, thereby improving the electrical efficiency of an electric vehicle.

[0014] The embodiments of the present invention can solve the problems occurring in the prior art and maintain the advantages achieved by the prior art.

[0015] Embodiments of the present invention provide a vehicle heating, ventilation and air conditioning (HVAC) system designed to improve heating performance and / or dehumidification performance utilizing refrigerant by using a control valve unit and a refrigerant heat exchanger disposed between a compressor and an interior condenser, thereby improving the electrical efficiency of an electric vehicle.

[0016] According to an embodiment of the present invention, a vehicle HVAC system may include a compressor, an interior condenser disposed at a downstream side of the compressor, a refrigerant heat exchanger located between the interior condenser and the compressor, a water-cooled heat exchanger disposed at a downstream side of the interior condenser and transferring heat between the refrigerant and a coolant circulating in a coolant system, an external heat exchanger disposed at a downstream side of the interior condenser and transferring heat between the refrigerant and ambient air, and a control valve unit controlling the flow of the refrigerant and the expansion and / or non-expansion of the refrigerant between the interior condenser, the water-cooled heat exchanger, the external heat exchanger, and the refrigerant heat exchanger. The refrigerant heat exchanger may be configured to transfer heat between the expanded refrigerant and the non-expanded refrigerant in the refrigerant discharged from the interior condenser.

[0017] The refrigerant heat exchanger may include a first passage through which an unexpanded refrigerant passes and a second passage through which an expanded refrigerant passes.

[0018] The control valve unit may include a first control valve allowing refrigerant exhausted from the internal condenser to be directed to the external heat exchanger or to bypass the external heat exchanger.

[0019] The first control valve may include an input port fluidly connected to the internal condenser, a first output port fluidly connected to the first passage of the refrigerant heat exchanger and the outlet of the external heat exchanger, and a second output port fluidly connected to the inlet of the external heat exchanger.

[0020] The first control valve may be configured to allow the input port to selectively communicate with the first output port or the second output port.

[0021] The control valve unit may include a second control valve that allows refrigerant discharged from the internal condenser or refrigerant discharged from the first passage of the refrigerant heat exchanger to be guided to the water-cooled heat exchanger.

[0022] The second control valve may include a first input port fluidly connected to the internal condenser, a second input port fluidly connected to the first passage of the refrigerant heat exchanger, and an output port fluidly connected to the first passage of the water-cooled heat exchanger.

[0023] The second control valve may be configured to allow the first input port or the second input port to selectively communicate with the output port.

[0024] When the first input port or the second input port is connected to the output port, the opening degree of the second control valve can be adjusted.

[0025] The control valve unit may include a third control valve allowing refrigerant exhausted from the internal condenser or the external heat exchanger to be guided to the second passage of the refrigerant heat exchanger.

[0026] The third control valve may include a first input port fluidly connected to the interior condenser, a second input port fluidly connected to the exterior heat exchanger, and an output port fluidly connected to an inlet of a second passage of the refrigerant heat exchanger.

[0027] The third control valve may be configured to allow the first input port or the second input port to selectively communicate with the output port.

[0028] The water-cooled heat exchanger and the external heat exchanger may be connected in parallel to the refrigerant circulation path.

[0029] The vehicle HVAC system may further include a cooling-side expansion valve located on a downstream side of the first passage of the refrigerant heat exchanger, and an evaporator located on a downstream side of the cooling-side expansion valve.

[0030] The inlet of the first channel of the refrigerant heat exchanger may be located on the downstream side of the internal condenser and the downstream side of the external heat exchanger, the inlet of the second channel of the refrigerant heat exchanger may be located on the downstream side of the internal condenser and the downstream side of the water-cooled heat exchanger, and the outlet of the second channel of the refrigerant heat exchanger may be located on the upstream side of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other purposes, features and advantages of the embodiments of the present invention will become more apparent through the following detailed description in conjunction with the accompanying drawings, in which:

[0032] Figure 1 A vehicle heating, ventilation and air conditioning (HVAC) system according to an exemplary embodiment of the present invention is described;

[0033] Figure 2 Describes the flow of refrigerant when a vehicle HVAC system according to an exemplary embodiment of the present invention is operated in a heating mode and ice formation occurs in an external heat exchanger;

[0034] Figure 3 Describing the flow of refrigerant when the vehicle HVAC system according to an exemplary embodiment of the present invention is operated in a heating mode and when icing does not occur in an external heat exchanger;

[0035] Figure 4 Describing the flow of refrigerant when the vehicle HVAC system according to an exemplary embodiment of the present invention operates in heating and dehumidification modes;

[0036] Figure 5 To explain the flow of refrigerant when the vehicle HVAC system according to the exemplary embodiment of the present invention operates in a heating and dehumidification enhancement mode; and

[0037] Figure 6 The flow of refrigerant when the vehicle HVAC system according to an exemplary embodiment of the present invention operates in the heating enhancement and dehumidification modes is described. DETAILED DESCRIPTION

[0038] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals will be used throughout to represent the same or equivalent elements. In addition, detailed descriptions of known techniques associated with the present invention will be omitted to avoid unnecessarily obscuring the main points of the present invention.

[0039] Terms such as first, second, A, B, (a) and (b) can be used to describe the elements in the exemplary embodiments of the present invention. These terms are only used to distinguish one element from another element, and the inherent characteristics, order or sequence of the corresponding elements, etc. are not limited by these terms. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as the meaning generally understood by the ordinary knowledge personnel of the field to which the present invention belongs. Such terms as defined in the commonly used dictionary are interpreted as having the same meaning as the contextual meaning in the relevant technical field, and are not interpreted as having an ideal or overly formal meaning, unless clearly defined as having such meaning in this application.

[0040] refer to Figure 1 According to an exemplary embodiment of the present invention, a vehicle heating, ventilation and air conditioning (HVAC) system may be configured to heat or cool the air in a cabin of a vehicle using a phase change of a circulating refrigerant. The HVAC system may include a refrigerant circulation path 30 and an HVAC housing 70 that allow the refrigerant to circulate therethrough. The refrigerant circulation path 30 may be fluidly connected to a compressor 11, an internal condenser 12, a water-cooled heat exchanger 25, an external heat exchanger 13, a cooling-side expansion valve 14, an evaporator 15, and a refrigerant heat exchanger 26. The refrigerant circulation path 30 may allow the flow of the refrigerant to vary according to various operating modes of the vehicle thermal management system.

[0041] The compressor 11 may compress the refrigerant to allow the refrigerant to circulate. The compressor 11 may include a compressor motor and a compression part operated by the compressor motor. The refrigerant circulation path 30 may be fluidly connected to the compression part of the compressor 11.

[0042] The HVAC system may include an accumulator 16 disposed at an upstream side of the compressor 11. The accumulator 16 may be located between the evaporator 15 and the compressor 11, and the accumulator 16 may separate liquid refrigerant from the refrigerant received by the evaporator 15, thereby preventing the liquid refrigerant from flowing into the compressor 11.

[0043] The interior condenser 12 may be configured to condense the refrigerant received from the compressor 11, and thus, air passing through the interior condenser 12 may be heated by the refrigerant passing through an internal passage of the interior condenser 12. When the air heated by the interior condenser 12 is guided into the vehicle cabin, the vehicle cabin may be heated.

[0044] The water-cooled heat exchanger 25 may be disposed on the downstream side of the interior condenser 12 and may be thermally connected to the coolant system 80. The water-cooled heat exchanger 25 may be configured to transfer heat between the coolant circulating in the coolant system 80 and the refrigerant circulating in the refrigerant circulation path 30.

[0045] According to an exemplary embodiment, the water-cooling type heat exchanger 25 and the external heat exchanger 13 may be connected to the refrigerant circulation path 30 in parallel.

[0046] According to an exemplary embodiment, the coolant system 80 may be a power electronics (PE) cooling system configured to cool a PE component 82. The coolant system 80 may include a coolant circulation path 81 through which a coolant circulates, a PE component 82 fluidly connected to the coolant circulation path 81, a PE radiator 83 fluidly connected to the coolant circulation path 81, and a pump 84 that pumps the coolant. The PE component 82 may be an electric motor, an inverter, and a power conversion component. The PE radiator 83 may be disposed adjacent to a front grille of the vehicle, and the coolant passing through the PE radiator 83 may be cooled by ambient air forcedly blown by a cooling fan. The PE component 82 may have a coolant channel disposed inside or outside thereof, and the coolant may pass through the coolant channel. The coolant channel of the PE component 82 may be fluidly connected to the coolant circulation path 81.

[0047] The water-cooled heat exchanger 25 may include a first channel 25a fluidly connected to the refrigerant circulation path 30 and a second channel 25b fluidly connected to the coolant circulation path 81. When the temperature of the PE component 82 increases, the coolant may absorb heat from the PE component 82, so that the temperature of the coolant may be relatively increased. The refrigerant passing through the first channel 25a of the water-cooled heat exchanger 25 may absorb heat from the coolant passing through the second channel 25b of the water-cooled heat exchanger 25, and thus the refrigerant may evaporate in the water-cooled heat exchanger 25.

[0048] The external heat exchanger 13 may be disposed on the downstream side of the internal condenser 12, and the external heat exchanger 13 may have a refrigerant passage through which the refrigerant passes. The external heat exchanger 13 may be disposed adjacent to the front grille of the vehicle, and the external heat exchanger 13 may directly contact the ambient air, so that the external heat exchanger 13 may be configured to transfer heat between the refrigerant and the ambient air. In particular, the external heat exchanger 13 may perform heat exchange with the ambient air forcibly blown by the cooling fan, so that the heat transfer rate between the refrigerant and the ambient air can be further improved.

[0049] When the refrigerant does not expand on the upstream side of the external heat exchanger 13, the unexpanded refrigerant may release heat to the ambient air and condense at the external heat exchanger 13. That is, when the refrigerant does not expand on the upstream side of the external heat exchanger 13, the external heat exchanger 13 may function as a condenser that condenses the refrigerant received from the internal condenser 12.

[0050] When the refrigerant expands on the upstream side of the external heat exchanger 13, the expanded refrigerant may absorb heat from the ambient air and evaporate at the external heat exchanger 13. That is, when the refrigerant expands on the upstream side of the external heat exchanger 13, the external heat exchanger 13 may function as an evaporator that evaporates the refrigerant received from the internal condenser 12.

[0051] The cooling side expansion valve 14 may be disposed on the downstream side of the external heat exchanger 13, and the cooling side expansion valve 14 may be located between the external heat exchanger 13 and the evaporator 15 in the refrigerant circulation path 30. The cooling side expansion valve 14 may be disposed on the upstream side of the evaporator 15, and may adjust the flow of the refrigerant entering the evaporator 15 and / or the flow rate of the refrigerant. During the cooling operation of the HVAC system, the cooling side expansion valve 14 may be configured to expand the refrigerant received from the external heat exchanger 13. According to an exemplary embodiment, the cooling side expansion valve 14 may be a thermal expansion valve (TXV) that senses the temperature and / or pressure of the refrigerant and adjusts the opening of the cooling side expansion valve 14.

[0052] The evaporator 15 may be provided on the downstream side of the cooling-side expansion valve 14, and may receive the refrigerant expanded by the cooling-side expansion valve 14. The evaporator 15 may be configured to cool the air using the refrigerant received from the cooling-side expansion valve 14. That is, the refrigerant expanded by the cooling-side expansion valve 14 may absorb heat from the air and evaporate at the evaporator 15. During the cooling operation of the HVAC system, the evaporator 15 may be configured to cool the air using the refrigerant cooled by the external heat exchanger 13 and expanded by the cooling-side expansion valve 14, and the air cooled by the refrigerant may be guided into the vehicle cabin.

[0053] The HVAC system according to an exemplary embodiment of the present invention may include a refrigerant heat exchanger 26 between the interior condenser 12 and the compressor 11. The refrigerant heat exchanger 26 may be configured to transfer heat between unexpanded refrigerant and expanded refrigerant in the refrigerant discharged from the interior condenser 12.

[0054] The refrigerant heat exchanger 26 may include a first passage 26a through which unexpanded refrigerant passes and a second passage 26b through which expanded refrigerant passes. The first passage 26a and the second passage 26b may be fluidly separated from each other.

[0055] An inlet of the first passage 26 a may be located on a downstream side of the interior condenser 12 and a downstream side of the exterior heat exchanger 13 , and an outlet of the first passage 26 a may be located on an upstream side of the cooling-side expansion valve 14 and the evaporator 15 .

[0056] An inlet of the second passage 26 b may be located at a downstream side of the interior condenser 12 and a downstream side of the water-cooled heat exchanger 25 , and an outlet of the second passage 26 b may be located at an upstream side of the compressor 11 and the accumulator 16 .

[0057] The refrigerant heat exchanger 26 may be configured to transfer heat between the unexpanded refrigerant passing through the first passage 26a and the expanded refrigerant passing through the second passage 26b. The temperature of the unexpanded refrigerant may be higher than the temperature of the expanded refrigerant. Therefore, the expanded refrigerant passing through the second passage 26b may absorb heat from the unexpanded refrigerant passing through the first passage 26a, so that the expanded refrigerant can be evaporated (heated) and the unexpanded refrigerant can be condensed (cooled).

[0058] The HVAC housing 70 may have an inlet and an outlet, and may be configured to allow air to be guided into the cabin of the vehicle. The evaporator 15 and the interior condenser 12 may be located inside the HVAC housing 70. An air mixing door 71 may be provided between the evaporator 15 and the interior condenser 12, and an electric heater 72 such as a positive temperature coefficient heater (PTC) may be provided on the downstream side of the interior condenser 12 in the air flow direction.

[0059] According to an exemplary embodiment of the present invention, an HVAC system may include a control valve unit 20, which controls the flow of refrigerant (the direction of the refrigerant, the flow rate of the refrigerant, etc.) between the internal condenser 12, the water-cooled heat exchanger 25, the external heat exchanger 13 and the refrigerant heat exchanger 26, and the expansion and / or non-expansion of the refrigerant.

[0060] The control valve unit 20 may include a first control valve 21 that controls the flow of the refrigerant in a manner that allows the refrigerant discharged from the interior condenser 12 to be directed to the exterior heat exchanger 13 or to bypass the exterior heat exchanger 13 .

[0061] The first control valve 21 may include an input port 21a fluidly connected to the interior condenser 12, a first output port 21b fluidly connected to the first passage 26a of the refrigerant heat exchanger 26 and the outlet of the exterior heat exchanger 13, and a second output port 21c fluidly connected to the inlet of the exterior heat exchanger 13. Refrigerant discharged from the interior condenser 12 may be guided to the input port 21a of the first control valve 21 through the second line 32. Refrigerant discharged from the first output port 21b of the first control valve 21 may bypass (bypass) the exterior heat exchanger 13 and be guided to the first passage 26a of the refrigerant heat exchanger 26, and refrigerant discharged from the second output port 21c of the first control valve 21 may be guided to the exterior heat exchanger 13.

[0062] The first control valve 21 may be configured to allow the input port 21a to selectively communicate with the first output port 21b or the second output port 21c using the first actuator 21f. For example, the first control valve 21 may allow the input port 21a to communicate with the first output port 21b or the second output port 21c by moving a valve member such as a ball member or a needle member in the valve housing. The valve member is actuated by the first actuator 21f.

[0063] When the first control valve 21 performs the first switching operation to allow the input port 21a to communicate with the first output port 21b, the refrigerant discharged from the interior condenser 12 may be guided to the first passage 26a of the refrigerant heat exchanger 26 through the input port 21a and the first output port 21b, thereby bypassing the exterior heat exchanger 13. When the first control valve 21 performs the first switching operation, the opening degree of the first control valve 21 may be adjusted to 100% using the valve member (that is, the first control valve 21 may be fully opened), and the refrigerant discharged from the first output port 21b of the first control valve 21 may not expand.

[0064] When the first control valve 21 performs the second switching operation to allow the input port 21a to communicate with the second output port 21c, the refrigerant discharged from the interior condenser 12 may be guided to the exterior heat exchanger 13 through the input port 21a and the second output port 21c. When the first control valve 21 performs the second switching operation, the opening of the first control valve 21 may be adjusted by the valve member so that the refrigerant may expand or may not expand. According to an exemplary embodiment, when the first control valve 21 performs the second switching operation, the opening of the first control valve 21 may be adjusted by the valve member to be lower than 100% and more than 0%, so that the refrigerant discharged from the second output port 21c of the first control valve 21 may expand. According to another exemplary embodiment, when the first control valve 21 performs the second switching operation, the opening of the first control valve 21 may be adjusted by the valve member to 100% (that is, the first control valve 21 may be fully opened), so that the refrigerant discharged from the second output port 21c of the first control valve 21 may not expand.

[0065] The control valve unit 20 may include a second control valve 22 that controls the flow of refrigerant in a manner allowing refrigerant discharged from the interior condenser 12 or the first passage 26 a of the refrigerant heat exchanger 26 to be guided to the first passage 25 a of the water-cooled heat exchanger 25 .

[0066] The second control valve 22 may include a first input port 22a fluidly connected to the interior condenser 12, a second input port 22b fluidly connected to an outlet of a first passage 26a of a refrigerant heat exchanger 26, and an output port 22c fluidly connected to an inlet of a first passage 25a of a water-cooled heat exchanger 25. Refrigerant discharged from the interior condenser 12 may be guided to the first input port 22a of the second control valve 22 through a second line 32, refrigerant discharged from the first passage 26a of the refrigerant heat exchanger 26 may be guided to the second input port 22b of the second control valve 22, and refrigerant discharged from the output port 22c of the second control valve 22 may be guided to the first passage 25a of the water-cooled heat exchanger 25.

[0067] The second control valve 22 may be configured to allow the first input port 22a or the second input port 22b to selectively communicate with the output port 22c through the second actuator 22f. For example, the second control valve 22 may allow the first input port 22a or the second input port 22b to communicate with the output port 22c by moving a valve member such as a ball member or a needle member in the valve housing. The valve member is actuated by the second actuator 22f.

[0068] When the second control valve 22 performs the first switching operation to allow the first input port 22a to communicate with the output port 22c, the refrigerant discharged from the interior condenser 12 can be guided to the first passage 25a of the water-cooled heat exchanger 25 through the first input port 22a and the output port 22c. When the second control valve 22 performs the first switching operation, the opening degree of the second control valve 22 can be adjusted to be lower than 100% and more than 0% using the valve member, so that the refrigerant discharged from the output port 22c of the second control valve 22 can expand.

[0069] When the second control valve 22 performs the second switching operation to allow the second input port 22b to communicate with the output port 22c, the refrigerant discharged from the first passage 26a of the refrigerant heat exchanger 26 can be guided to the first passage 25a of the water-cooled heat exchanger 25 through the second input port 22b and the output port 22c. When the second control valve 22 performs the second switching operation, the opening degree of the second control valve 22 can be adjusted to be lower than 100% and more than 0% using the valve member, so that the refrigerant discharged from the output port 22c of the second control valve 22 can expand.

[0070] The control valve unit 20 may include a third control valve 23 that controls the flow of refrigerant in a manner that allows refrigerant discharged from the interior condenser 12 or refrigerant discharged from the exterior heat exchanger 13 to be guided to the second passage 26 b of the refrigerant heat exchanger 26 .

[0071] The third control valve 23 may include a first input port 23a fluidly connected to the interior condenser 12, a second input port 23b fluidly connected to the first passage 26a of the refrigerant heat exchanger 26 and the outlet of the exterior heat exchanger 13, and an output port 23c fluidly connected to the inlet of the second passage 26b of the refrigerant heat exchanger 26. Refrigerant discharged from the interior condenser 12 may be guided to the first input port 23a of the third control valve 23 through the second line 32, refrigerant discharged from the exterior heat exchanger 13 may be guided to the second input port 23b of the third control valve 23, and refrigerant discharged from the output port 23c of the third control valve 23 may be guided to the second passage 26b of the refrigerant heat exchanger 26.

[0072] The third control valve 23 may be configured to allow the first input port 23a or the second input port 23b to selectively communicate with the output port 23c through the third actuator 23f. For example, the third control valve 23 may allow the first input port 23a or the second input port 23b to communicate with the output port 23c by moving a valve member such as a ball member or a needle member in the valve housing. The valve member is actuated by the third actuator 23f.

[0073] When the third control valve 23 performs the first switching operation to allow the first input port 23a to communicate with the output port 23c, the refrigerant discharged from the interior condenser 12 can be guided to the second passage 26b of the refrigerant heat exchanger 26 through the first input port 23a and the output port 23c. According to an exemplary embodiment, when the third control valve 23 performs the first switching operation, the opening degree of the third control valve 23 can be adjusted to be lower than 100% and more than 0% using a valve member so that the refrigerant discharged from the output port 23c of the third control valve 23 can expand. According to another exemplary embodiment, the diameter of the output port 23c can be smaller than the diameter of the first input port 23a and the diameter of the second input port 23b, so when the third control valve 23 performs the first switching operation, the flow rate of the refrigerant discharged from the output port 23c can be relatively low.

[0074] When the third control valve 23 performs the second switching operation to allow the second input port 23b to communicate with the output port 23c, the refrigerant discharged from the external heat exchanger 13 may be guided to the second passage 26b of the refrigerant heat exchanger 26 through the second input port 23b and the output port 23c. When the third control valve 23 performs the second switching operation, the opening degree of the third control valve 23 may be adjusted to 100% (i.e., the third control valve 23 may be fully opened) using the valve member so that the refrigerant discharged from the output port 23c of the third control valve 23 may not expand.

[0075] When ice formation occurs in the external heat exchanger 13 due to low ambient temperature, the refrigerant may not absorb heat from the ambient air through the external heat exchanger 13. In addition, when the calorific value of the PE component 82 is not high, the refrigerant may not absorb heat from the coolant system 80 through the water-cooled heat exchanger 25. In the case where the refrigerant does not absorb heat through the external heat exchanger 13 and / or the water-cooled heat exchanger 25, when the third control valve 23 performs the first switching operation, the refrigerant discharged from the internal condenser 12 may merge with the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25 through the third control valve 23. The temperature of the refrigerant discharged from the output port 23c of the third control valve 23 may be higher than the temperature of the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25. The refrigerant discharged from the internal condenser 12 and the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25 may merge at the connection point 63, so that the temperature of the refrigerant may be relatively increased. Then, the refrigerant may be guided to the second passage 26 b of the refrigerant heat exchanger 26 , so that the refrigerant evaporation performance of the refrigerant heat exchanger 26 can be improved.

[0076] The first control valve 21 , the second control valve 22 , and the third control valve 23 may form a single module, so the control valve unit 20 and the HVAC system are easier to assemble.

[0077] See also Figure 1 The refrigerant circulation path 30 may include a first pipeline 31 extending from the outlet of the compressor 11 to the internal condenser 12, a second pipeline 32 extending from the internal condenser 12 to the control valve unit 20, a third pipeline 33 extending from the control valve unit 20 to the inlet of the external heat exchanger 13, a fourth pipeline 34 extending from the outlet of the external heat exchanger 13 to the inlet of the evaporator 15, a fifth pipeline 35 extending from the outlet of the evaporator 15 to a downstream point of the first channel 25a of the water-cooled heat exchanger 25, and a sixth pipeline 36 extending from the fifth pipeline 35 to the inlet of the compressor 11.

[0078] The first channel 26a of the refrigerant heat exchanger 26 may be fluidly connected to the fourth line 34, and the second channel 26b of the refrigerant heat exchanger 26 may be fluidly connected to the sixth line 36. The connection point 63 of the fifth line 35 and the sixth line 36 may be located at the downstream side of the first channel 25a of the water-cooled heat exchanger 25 and the upstream side of the first channel 26a of the refrigerant heat exchanger 26.

[0079] The refrigerant discharged from the interior condenser 12 may be guided to at least one of the exterior heat exchanger 13, the refrigerant heat exchanger 26, and the water-cooled heat exchanger 25 through the branch point 40. The branch point 40 may be provided at the outlet of the second pipeline 32, and the branch point 40 may be located between the first control valve 21, the second control valve 22, and the third control valve 23.

[0080] The first branch line 41 may extend from the branch point 40 to the input port 21a of the first control valve 21, and the first branch line 41 may be configured to guide at least a portion of the refrigerant discharged from the interior condenser 12 to the input port 21a of the first control valve 21. At least a portion of the refrigerant discharged from the interior condenser 12 may be guided from the branch point 40 to the input port 21a of the first control valve 21 through the first branch line 41.

[0081] The second branch line 42 may extend from the branch point 40 to the first input port 22a of the second control valve 22, and the second branch line 42 may be configured to guide at least a portion of the refrigerant discharged from the interior condenser 12 to the first input port 22a of the second control valve 22. At least a portion of the refrigerant discharged from the interior condenser 12 may be guided from the branch point 40 to the first input port 22a of the second control valve 22 through the second branch line 42.

[0082] The third branch line 43 may extend from the branch point 40 to the first input port 23a of the third control valve 23, and the third branch line 43 may be configured to guide at least a portion of the refrigerant discharged from the interior condenser 12 to the first input port 23a of the third control valve 23. At least a portion of the refrigerant discharged from the interior condenser 12 may be guided from the branch point 40 to the first input port 23a of the third control valve 23 through the third branch line 43.

[0083] The exterior heat exchanger 13 and the first passage 25 a of the water-cooling type heat exchanger 25 may be connected in parallel to the refrigerant circulation path 30 through the first branch line 41 , the second branch line 42 , and the third branch line 43 .

[0084] The first output port 21b of the first control valve 21 may be fluidly connected to the fourth line 34 through the first connecting line 51. The first connecting line 51 may be configured to allow the refrigerant discharged from the first output port 21b of the first control valve 21 to bypass the external heat exchanger 13 and be guided to the first passage 26a of the refrigerant heat exchanger 26 through the fourth line 34. The inlet of the first connecting line 51 may be connected to the first output port 21b of the first control valve 21. The outlet of the first connecting line 51 may be connected to the fourth line 34 at a connection point 61 between the first passage 26a of the refrigerant heat exchanger 26 and the external heat exchanger 13.

[0085] The output port 22c of the second control valve 22 may be fluidly connected to a connection point 63 of the fifth line 35 and the sixth line 36 through a second connecting line 52. The second connecting line 52 may be configured to guide the refrigerant discharged from the output port 22c of the second control valve 22 to the first channel 25a of the water-cooled heat exchanger 25. An inlet of the second connecting line 52 may be connected to the output port 22c of the second control valve 22. An outlet of the second connecting line 52 may be connected to a connection point 63 of the fifth line 35 and the sixth line 36. The water-cooled heat exchanger 25 may be disposed at the second connecting line 52, and the first channel 25a of the water-cooled heat exchanger 25 may be connected to the second connecting line 52. The refrigerant discharged from the output port 22c of the second control valve 22 may pass through the first channel 25a of the water-cooled heat exchanger 25, and the refrigerant discharged from the first channel 25a of the water-cooled heat exchanger 25 may be guided to the second channel 26b of the refrigerant heat exchanger 26 through the sixth line 36. Therefore, the water-cooling type heat exchanger 25 may be fluidly connected to the refrigerant circulation path 30 through the second connection line 52 , and the water-cooling type heat exchanger 25 and the external heat exchanger 13 may be connected to the refrigerant circulation path 30 in parallel.

[0086] The second input port 22b of the second control valve 22 may be fluidly connected to the fourth line 34 through a fifth connecting line 55. The fifth connecting line 55 may be configured to guide a portion of the refrigerant discharged from the first passage 26a of the refrigerant heat exchanger 26 to the second input port 22b of the second control valve 22. An inlet of the fifth connecting line 55 may be connected to the fourth line 34 at a connecting point 64 located on the downstream side of the first passage 26a of the refrigerant heat exchanger 26. An outlet of the fifth connecting line 55 may be connected to the second input port 22b of the second control valve 22.

[0087] The second input port 23b of the third control valve 23 may be fluidly connected to the fourth line 34 through a third connecting line 53. The third connecting line 53 may be configured to guide the refrigerant discharged from the outlet of the external heat exchanger 13 to the second input port 23b of the third control valve 23. The inlet of the third connecting line 53 may be connected to the fourth line 34 at a connecting point 62 located on the upstream side of the first passage 26a of the refrigerant heat exchanger 26. The outlet of the third connecting line 53 may be connected to the second input port 23b of the third control valve 23.

[0088] The output port 23c of the third control valve 23 may be fluidly connected to the sixth pipeline 36 through the fourth connecting line 54. The fourth connecting line 54 may be configured to guide the refrigerant discharged from the output port 23c of the third control valve 23 to the second passage 26b of the refrigerant heat exchanger 26. An inlet of the fourth connecting line 54 may be connected to the output port 23c of the third control valve 23. An outlet of the fourth connecting line 54 may be connected to a connection point 63 of the fifth pipeline 35 and the sixth pipeline 36. The refrigerant discharged from the output port 23c of the third control valve 23 and the refrigerant discharged from the second connecting line 52 may be combined at the connection point 63 and then may be guided to the sixth pipeline 36.

[0089] The controller 100 may be configured to control the compressor 11, the first actuator 21f of the first control valve 21, the second actuator 22f of the second control valve 22, the third actuator 23f of the third control valve 23, the pump 84 of the coolant system 80, the cooling side expansion valve 14, the air mixing door 71 and the electric heater 72, respectively. Therefore, the overall operation of the HVAC system may be controlled by the controller 100. According to an exemplary embodiment, the controller 100 may be a fully automatic temperature control (FATC) system. The controller 100 may include a processor and a memory. The processor may be programmed to receive instructions stored in the memory and may transmit the instructions to the HVAC system. The memory may be a data storage device such as a hard disk drive, a solid state drive, a server, a volatile storage medium, and a non-volatile storage medium.

[0090] Figure 2 The flow of refrigerant when the HVAC system according to the exemplary embodiment of the present invention is operated in a heating mode and icing occurs in the exterior heat exchanger 13 because the ambient temperature is lower than a threshold temperature is described.

[0091] refer to Figure 2, the cooling-side expansion valve 14 may be closed, and the refrigerant compressed by the compressor 11 may flow into the interior condenser 12. The refrigerant passing through the interior condenser 12 may be cooled by the air passing through the HVAC housing 70, so that the refrigerant passing through the interior condenser 12 may be condensed by the air. The first control valve 21 may perform a first switching operation to allow the input port 21a to communicate with the first output port 21b, so that a portion of the refrigerant discharged from the interior condenser 12 may be guided to the first passage 26a of the refrigerant heat exchanger 26 through the first output port 21b of the first control valve 21, and bypass the exterior heat exchanger 13.

[0092] refer to Figure 2 , the second control valve 22 may perform a second switching operation to allow the second input port 22b to communicate with the output port 22c, so that the refrigerant discharged from the first passage 26a of the refrigerant heat exchanger 26 may be guided to the first passage 25a of the water-cooled heat exchanger 25 through the second input port 22b and the output port 22c of the second control valve 22. When the second control valve 22 performs the second switching operation, the refrigerant discharged from the output port 22c of the second control valve 22 may expand, and the refrigerant expanded by the second control valve 22 may be guided to the first passage 25a of the water-cooled heat exchanger 25. The refrigerant passing through the first passage 25a of the water-cooled heat exchanger 25 may absorb heat from the coolant passing through the second passage 25b, and thus the refrigerant may evaporate in the water-cooled heat exchanger 25.

[0093] refer to Figure 2 , the third control valve 23 may perform a first switching operation to allow the first input port 23a to communicate with the output port 23c, so that the remaining portion of the refrigerant discharged from the interior condenser 12 may be guided to the second passage 26b of the refrigerant heat exchanger 26 through the first input port 23a and the output port 23c of the third control valve 23. The remaining portion of the refrigerant discharged from the interior condenser 12 may be guided to the connection point 63 located at the downstream side of the first passage 25a of the water-cooled heat exchanger 25 through the first input port 23a and the output port 23c of the third control valve 23. When the third control valve 23 performs the first switching operation, the remaining portion of the refrigerant discharged from the interior condenser 12 may merge with the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25 through the third control valve 23. The temperature of the refrigerant discharged from the output port 23c of the third control valve 23 may be higher than the temperature of the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25. The refrigerant discharged from the interior condenser 12 and the refrigerant discharged from the first channel 25a of the water-cooled heat exchanger 25 may be combined at the connection point 63, so that the temperature of the refrigerant can be relatively increased. Then, the refrigerant may be guided to the second channel 26b of the refrigerant heat exchanger 26, so that the refrigerant evaporation performance of the refrigerant heat exchanger 26 can be improved.

[0094] refer to Figure 2 , the refrigerant discharged from the first output port 21b of the first control valve 21 may not expand, and the refrigerant discharged from the output port 22c of the second control valve 22 may expand. The temperature of the refrigerant discharged from the first output port 21b of the first control valve 21 may be higher than the temperature of the refrigerant discharged from the output port 22c of the second control valve 22. The unexpanded refrigerant may pass through the first passage 26a of the refrigerant heat exchanger 26, and the expanded refrigerant may pass through the second passage 26b of the refrigerant heat exchanger 26, so that the expanded refrigerant can be evaporated by the unexpanded refrigerant, and the unexpanded refrigerant can be condensed by the expanded refrigerant.

[0095] refer to Figure 2 , when the HVAC system is operated in the heating mode under the condition of relatively low ambient temperature, ice may occur in the external heat exchanger 13, so the refrigerant may need to bypass the external heat exchanger 13. In addition, because the calorific value of the PE component 82 is not high, the temperature of the coolant circulating in the coolant circulation path 81 of the coolant system 80 may not be relatively high. Therefore, the refrigerant passing through the first channel 25a of the water-cooled heat exchanger 25 may not fully absorb heat from the second channel 25b of the water-cooled heat exchanger 25, and thus the refrigerant may not be fully evaporated in the water-cooled heat exchanger 25. That is, under the condition of relatively low ambient temperature, the refrigerant may not fully absorb heat from the external heat exchanger 13 and the water-cooled heat exchanger 25. In order to solve this problem, the HVAC system according to the exemplary embodiment of the present invention may allow the refrigerant heat exchanger 26 to additionally provide heat for refrigerant evaporation under relatively low ambient temperature conditions. Therefore, the refrigerant can be evaporated in two steps (stages) through the water-cooled heat exchanger 25 and the refrigerant heat exchanger 26, so that the superheating of the refrigerant can be ensured. In addition, after a portion of the refrigerant discharged from the interior condenser 12 and the refrigerant discharged from the first channel 25a of the water-cooled heat exchanger 25 are merged through the third control valve 23, the refrigerant can be guided to the second channel 26b of the refrigerant heat exchanger 26 so that the refrigerant can additionally absorb heat. Therefore, the refrigerant evaporation performance is further improved.

[0096] Figure 3 The flow of refrigerant when the HVAC system according to the exemplary embodiment of the present invention is operated in the heating mode and icing does not occur in the exterior heat exchanger 13 because the ambient temperature is higher than the threshold temperature is described.

[0097] refer to Figure 3, the cooling-side expansion valve 14 may be closed, and the refrigerant compressed by the compressor 11 may flow into the interior condenser 12. The refrigerant passing through the interior condenser 12 may be cooled by the air passing through the HVAC housing 70, so that the refrigerant passing through the interior condenser 12 may be condensed by the air. The first control valve 21 may perform a second switching operation to allow the input port 21a to communicate with the second output port 21c, so that a portion of the refrigerant discharged from the interior condenser 12 may be guided to the exterior heat exchanger 13 through the second output port 21c of the first control valve 21. At this time, when the first control valve 21 performs the second switching operation, the opening degree of the first control valve 21 may be adjusted to be lower than 100% and more than 0% by the valve member, so that the refrigerant discharged from the second output port 21c of the first control valve 21 may be expanded. The refrigerant expanded by the first control valve 21 may be guided to the exterior heat exchanger 13. The refrigerant passing through the exterior heat exchanger 13 may absorb heat from the ambient air, so that the refrigerant may be evaporated.

[0098] refer to Figure 3 , the second control valve 22 may perform a first switching operation to allow the first input port 22a to communicate with the output port 22c, so that the remaining portion of the refrigerant discharged from the interior condenser 12 may pass through the first passage 25a of the water-cooled heat exchanger 25. When the second control valve 22 performs the first switching operation, the refrigerant discharged from the output port 22c of the second control valve 22 may expand. The refrigerant expanded by the second control valve 22 may be guided to the first passage 25a of the water-cooled heat exchanger 25. The refrigerant passing through the first passage 25a of the water-cooled heat exchanger 25 may absorb heat from the coolant passing through the second passage 25b, and thus the refrigerant may evaporate in the water-cooled heat exchanger 25.

[0099] refer to Figure 3 , the third control valve 23 may perform a second switching operation to allow the second input port 23b to communicate with the output port 23c, so that the refrigerant discharged from the external heat exchanger 13 may be guided to the second passage 26b of the refrigerant heat exchanger 26 through the second input port 23b and the output port 23c of the third control valve 23, the fourth connecting line 54, and the sixth line 36. When the third control valve 23 performs the second switching operation, the opening degree of the third control valve 23 may be adjusted to 100% using the valve member (that is, the third control valve 23 may be fully opened), and the refrigerant discharged from the output port 23c of the third control valve 23 may not expand.

[0100] refer to Figure 3After the refrigerant discharged from the output port 23c of the third control valve 23 and the refrigerant discharged from the first channel 25a of the water-cooled heat exchanger 25 merge at the connection point 63, the refrigerant can be guided to the second channel 26b of the refrigerant heat exchanger 26, and the refrigerant discharged from the second channel 26b of the refrigerant heat exchanger 26 can be guided to the compressor 11.

[0101] refer to Figure 3 , when the ambient temperature is relatively high, the refrigerant can evaporate through the external heat exchanger 13 and the water-cooled heat exchanger 25, so the refrigerant evaporation performance can be fully realized.

[0102] Figure 4 The flow of refrigerant when the HVAC system according to the exemplary embodiment of the present invention operates in the heating and dehumidification modes is described.

[0103] refer to Figure 4 , the refrigerant compressed by the compressor 11 may flow into the interior condenser 12, and the refrigerant passing through the interior condenser 12 may be cooled by the air passing through the HVAC housing 70, so that the refrigerant passing through the interior condenser 12 may be condensed by the air. The first control valve 21 may perform a first switching operation to allow the input port 21a to communicate with the first output port 21b, so that a portion of the refrigerant discharged from the interior condenser 12 may be guided to the first passage 26a of the refrigerant heat exchanger 26 through the first output port 21b of the first control valve 21, and bypass the exterior heat exchanger 13.

[0104] refer to Figure 4 , the second control valve 22 may perform a first switching operation to allow the first input port 22a to communicate with the output port 22c, so that the remaining portion of the refrigerant discharged from the interior condenser 12 may pass through the first passage 25a of the water-cooled heat exchanger 25. When the second control valve 22 performs the first switching operation, the refrigerant discharged from the output port 22c of the second control valve 22 may expand. The refrigerant expanded by the second control valve 22 may be guided to the first passage 25a of the water-cooled heat exchanger 25. The refrigerant passing through the first passage 25a of the water-cooled heat exchanger 25 may absorb heat from the coolant passing through the second passage 25b, so that the refrigerant can evaporate in the water-cooled heat exchanger 25.

[0105] refer to Figure 4, the cooling side expansion valve 14 may be opened, and the first input port 23a, the second input port 23b, and the output port 23c of the third control valve 23 may all be closed. The refrigerant discharged from the first passage 26a of the refrigerant heat exchanger 26 may be guided to the evaporator 15 through the cooling side expansion valve 14. The refrigerant may be expanded using the cooling side expansion valve 14, and the expanded refrigerant may be evaporated by the evaporator 15. After the refrigerant discharged from the evaporator 15 and the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25 are joined at the connection point 63, the refrigerant may be guided to the second passage 26b of the refrigerant heat exchanger 26, and the refrigerant discharged from the second passage 26b of the refrigerant heat exchanger 26 may be guided to the compressor 11. The air passing through the HVAC housing 70 may be cooled by the evaporator 15, so that the air flowing into the passenger compartment may be dehumidified.

[0106] refer to Figure 4 , the refrigerant discharged from the first output port 21b of the first control valve 21 may not expand, and the refrigerant discharged from the output port 22c of the second control valve 22 may expand. The temperature of the refrigerant discharged from the first output port 21b of the first control valve 21 may be higher than the temperature of the refrigerant discharged from the output port 22c of the second control valve 22. The unexpanded refrigerant may pass through the first passage 26a of the refrigerant heat exchanger 26, and the expanded refrigerant may pass through the second passage 26b of the refrigerant heat exchanger 26, so that the expanded refrigerant may be evaporated by the unexpanded refrigerant, and the unexpanded refrigerant may be condensed by the expanded refrigerant. Therefore, the refrigerant may be condensed in two steps by the internal condenser 12 and the refrigerant heat exchanger 26, so that subcooling of the refrigerant can be ensured, and the refrigerant may be evaporated in two steps by the water-cooled heat exchanger 25 and the refrigerant heat exchanger 26, so that superheating of the refrigerant can be ensured.

[0107] Figure 5 The flow of refrigerant when the HVAC system according to the exemplary embodiment of the present invention operates in the heating and dehumidification enhancement mode is described.

[0108] refer to Figure 5, the refrigerant compressed by the compressor 11 may flow into the interior condenser 12, and the refrigerant passing through the interior condenser 12 may be cooled by the air passing through the HVAC housing 70, so that the refrigerant passing through the interior condenser 12 may be condensed by the air. The first control valve 21 may perform a second switching operation to allow the input port 21a to communicate with the second output port 21c, so that a portion of the refrigerant discharged from the interior condenser 12 may be guided to the exterior heat exchanger 13 through the second output port 21c of the first control valve 21. At this time, when the first control valve 21 performs the second switching operation, the opening degree of the first control valve 21 may be adjusted to 100% using the valve member (that is, the first control valve 21 may be fully opened), so that the refrigerant discharged from the second output port 21c of the first control valve 21 may not expand. The refrigerant may release heat to the ambient air through the exterior heat exchanger 13, so that the refrigerant may be cooled and condensed by the ambient air.

[0109] refer to Figure 5 , the second control valve 22 may perform a first switching operation to allow the first input port 22a to communicate with the output port 22c, so that the remaining portion of the refrigerant discharged from the interior condenser 12 may pass through the first passage 25a of the water-cooled heat exchanger 25. When the second control valve 22 performs the first switching operation, the refrigerant discharged from the output port 22c of the second control valve 22 may expand. The refrigerant expanded by the second control valve 22 may be guided to the first passage 25a of the water-cooled heat exchanger 25. The refrigerant passing through the first passage 25a of the water-cooled heat exchanger 25 may absorb heat from the coolant passing through the second passage 25b, so that the refrigerant can evaporate in the water-cooled heat exchanger 25.

[0110] refer to Figure 5 , the cooling side expansion valve 14 may be opened, and the first input port 23a, the second input port 23b, and the output port 23c of the third control valve 23 may all be closed. The refrigerant discharged from the first passage 26a of the refrigerant heat exchanger 26 may be guided to the evaporator 15 through the cooling side expansion valve 14. The refrigerant may be expanded using the cooling side expansion valve 14, and the expanded refrigerant may be evaporated by the evaporator 15. After the refrigerant discharged from the evaporator 15 and the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25 are joined at the connection point 63, the refrigerant may be guided to the second passage 26b of the refrigerant heat exchanger 26, and the refrigerant discharged from the second passage 26b of the refrigerant heat exchanger 26 may be guided to the compressor 11. The air passing through the HVAC housing 70 may be cooled by the evaporator 15, so that the air flowing into the passenger compartment may be dehumidified.

[0111] refer to Figure 5, the refrigerant discharged from the second output port 21c of the first control valve 21 may not expand, while the refrigerant discharged from the output port 22c of the second control valve 22 may expand. The unexpanded refrigerant may pass through the first channel 26a of the refrigerant heat exchanger 26, and the expanded refrigerant may pass through the second channel 26b of the refrigerant heat exchanger 26, so that the expanded refrigerant may be evaporated by the unexpanded refrigerant in the refrigerant heat exchanger 26, and the unexpanded refrigerant may be condensed by the expanded refrigerant in the refrigerant heat exchanger 26. Therefore, the refrigerant may be condensed in three steps through the internal condenser 12, the external heat exchanger 13, and the refrigerant heat exchanger 26, so that the supercooling of the refrigerant can be ensured, and the refrigerant may be evaporated in two steps through the water-cooled heat exchanger 25 and the refrigerant heat exchanger 26, so that the superheating of the refrigerant can be ensured. By ensuring the supercooling of the refrigerant and the superheating of the refrigerant, the suction pressure of the compressor 11 can be relatively reduced, so that the power consumption of the compressor 11 can be minimized.

[0112] Figure 6 The flow of refrigerant when the HVAC system according to the exemplary embodiment of the present invention operates in the heating enhancement and dehumidification modes is described.

[0113] refer to Figure 6 , the refrigerant compressed by the compressor 11 may flow into the interior condenser 12, and the refrigerant passing through the interior condenser 12 may be cooled by the air passing through the HVAC housing 70, so that the refrigerant passing through the interior condenser 12 may be condensed by the air. The first control valve 21 may perform a first switching operation to allow the input port 21a to communicate with the first output port 21b, so that a portion of the refrigerant discharged from the interior condenser 12 may be guided to the first passage 26a of the refrigerant heat exchanger 26 through the first output port 21b of the first control valve 21, and bypass the exterior heat exchanger 13.

[0114] refer to Figure 6 , the second control valve 22 may perform a first switching operation to allow the first input port 22a to communicate with the output port 22c, so that the remaining portion of the refrigerant discharged from the interior condenser 12 may pass through the first passage 25a of the water-cooled heat exchanger 25. When the second control valve 22 performs the first switching operation, the refrigerant discharged from the output port 22c of the second control valve 22 may expand. The refrigerant expanded by the second control valve 22 may be guided to the first passage 25a of the water-cooled heat exchanger 25. The refrigerant passing through the first passage 25a of the water-cooled heat exchanger 25 may absorb heat from the coolant passing through the second passage 25b, and thus the refrigerant may evaporate in the water-cooled heat exchanger 25.

[0115] refer to Figure 6, the cooling-side expansion valve 14 may be opened, and the refrigerant discharged from the first passage 26a of the refrigerant heat exchanger 26 may be guided to the evaporator 15 through the cooling-side expansion valve 14. The refrigerant may be expanded using the cooling-side expansion valve 14, and the expanded refrigerant may be evaporated by the evaporator 15. After the refrigerant discharged from the evaporator 15 and the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25 are joined at the connection point 63, the refrigerant may be guided to the second passage 26b of the refrigerant heat exchanger 26, and the refrigerant discharged from the second passage 26b of the refrigerant heat exchanger 26 may be guided to the compressor 11. The air passing through the HVAC case 70 may be cooled by the evaporator 15, so that the air flowing into the cabin may be dehumidified.

[0116] refer to Figure 6 , the third control valve 23 may perform a first switching operation to allow the first input port 23a to communicate with the output port 23c, so that the remaining portion of the refrigerant discharged from the interior condenser 12 may be guided to the second passage 26b of the refrigerant heat exchanger 26 through the first input port 23a and the output port 23c of the third control valve 23. The remaining portion of the refrigerant discharged from the interior condenser 12 may be guided to the connection point 63 located at the downstream side of the first passage 25a of the water-cooled heat exchanger 25 through the first input port 23a and the output port 23c of the third control valve 23. When the third control valve 23 performs the first switching operation, the remaining portion of the refrigerant discharged from the interior condenser 12 may merge with the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25 through the third control valve 23. The temperature of the refrigerant discharged from the output port 23c of the third control valve 23 may be higher than the temperature of the refrigerant discharged from the first passage 25a of the water-cooled heat exchanger 25. The refrigerant discharged from the interior condenser 12 and the refrigerant discharged from the first channel 25a of the water-cooled heat exchanger 25 may be combined at the connection point 63, so that the temperature of the refrigerant may be relatively increased. Then, the refrigerant may be guided to the second channel 26b of the refrigerant heat exchanger 26, so that the refrigerant evaporation performance of the refrigerant heat exchanger 26 can be improved.

[0117] refer to Figure 6, the refrigerant discharged from the first output port 21b of the first control valve 21 may not be expanded, and the refrigerant discharged from the output port 22c of the second control valve 22 may be expanded. The unexpanded refrigerant may pass through the first passage 26a of the refrigerant heat exchanger 26, and the expanded refrigerant may pass through the second passage 26b of the refrigerant heat exchanger 26, so that the expanded refrigerant may be evaporated by the unexpanded refrigerant in the refrigerant heat exchanger 26, and the unexpanded refrigerant may be condensed by the expanded refrigerant in the refrigerant heat exchanger 26. The refrigerant may be condensed in two steps by the internal condenser 12 and the refrigerant heat exchanger 26, so that the supercooling of the refrigerant can be ensured, and the refrigerant may be evaporated by the evaporator 15, the water-cooled heat exchanger 25, and the refrigerant heat exchanger 26, so that the superheating of the refrigerant can be ensured. By ensuring the supercooling of the refrigerant and the superheating of the refrigerant, the heating of the vehicle compartment can be performed quickly.

[0118] As described above, the HVAC system according to the exemplary embodiment of the present invention can allow the refrigerant heat exchanger to provide additional heat for the evaporation of the refrigerant under relatively low ambient temperature conditions. Therefore, the refrigerant can be evaporated in two steps through the water-cooled heat exchanger and the refrigerant heat exchanger, so that the superheat of the refrigerant can be ensured.

[0119] According to an exemplary embodiment of the present invention, when the HVAC system is operated in a heating mode and icing occurs in the external heat exchanger, a portion of the refrigerant discharged from the internal condenser and the refrigerant discharged from the water-cooled heat exchanger may be combined through a third control valve, and then the refrigerant may be directed to the refrigerant heat exchanger so that the refrigerant may additionally absorb heat.

[0120] According to an exemplary embodiment of the present invention, in a case where the ambient temperature is relatively high, the refrigerant may be evaporated through the external heat exchanger and the water-cooled heat exchanger, and thus the refrigerant evaporation performance can be improved.

[0121] According to an exemplary embodiment of the present invention, when the HVAC system operates in the heating and dehumidification modes, the refrigerant can be condensed in three steps through the internal condenser, the external heat exchanger, and the refrigerant heat exchanger, so that the refrigerant can be supercooled, and the refrigerant can be evaporated in two steps through the water-cooled heat exchanger and the refrigerant heat exchanger, so that the refrigerant can be superheated. By ensuring the supercooling of the refrigerant and the superheating of the refrigerant, the suction pressure of the compressor can be relatively reduced, so that the power consumption of the compressor can be minimized.

[0122] According to an exemplary embodiment of the present invention, when the HVAC system operates in the heating enhancement and dehumidification mode, the refrigerant can be condensed in two steps through the interior condenser and the refrigerant heat exchanger, so that the refrigerant can be supercooled, and the refrigerant can be evaporated through the evaporator, the water-cooled heat exchanger and the refrigerant heat exchanger, so that the refrigerant can be superheated. By ensuring the supercooling of the refrigerant and the superheating of the refrigerant, the heating of the vehicle cabin can be performed quickly.

[0123] Although the embodiments of the present invention have been described above with reference to the exemplary embodiments and the accompanying drawings, the present invention is not limited thereto and various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present invention.

[0124] Reference numerals

[0125] 11: Compressor

[0126] 12: Internal condenser

[0127] 13: External heat exchanger

[0128] 14: Cooling side expansion valve

[0129] 15: Evaporator

[0130] 16: Liquid reservoir

[0131] 20: Control valve unit

[0132] 21: First control valve

[0133] 22: Second control valve

[0134] 23: The third control valve

[0135] 25: Water-cooled heat exchanger

[0136] 26: Refrigerant heat exchanger

[0137] 30: Refrigerant circulation path

[0138] 31: First Pipeline

[0139] 32: Second pipeline

[0140] 33: The third pipeline

[0141] 34: The fourth pipeline

[0142] 35: Fifth Pipeline

[0143] 36: Pipeline 6

[0144] 40: Branching point

[0145] 41: First branch pipeline

[0146] 42: Second branch pipeline

[0147] 43: The third branch pipeline

[0148] 51: First connecting pipeline

[0149] 52: Second connecting pipeline

[0150] 53: Third connecting pipeline

[0151] 54: Fourth connecting pipeline

[0152] 55: Fifth connecting pipeline

[0153] 70: HVAC housing

[0154] 71: Air mix door

[0155] 72: Electric heater

[0156] 80: Coolant system

[0157] 81: Coolant circulation path

[0158] 82: PE parts

[0159] 83: PE radiator

[0160] 84: Pump

[0161] 100: Controller.

Claims

1. A vehicle HVAC system for heating, ventilating and air-conditioning a vehicle, comprising: compressor; an internal condenser disposed on a downstream side of the compressor; a refrigerant heat exchanger located between the internal condenser and the compressor, the refrigerant heat exchanger being configured to transfer heat between expanded refrigerant and unexpanded refrigerant in the refrigerant discharged from the internal condenser; a water-cooled heat exchanger disposed on a downstream side of the internal condenser and configured to transfer heat between the refrigerant and a coolant circulating in a coolant system; an external heat exchanger disposed on a downstream side of the internal condenser and configured to transfer heat between the refrigerant and ambient air; as well as A control valve unit is configured to control the flow of the refrigerant between the internal condenser, the water-cooled heat exchanger, the external heat exchanger, and the refrigerant heat exchanger and the expansion and / or non-expansion of the refrigerant.

2. The vehicle HVAC system of claim 1, wherein: The refrigerant heat exchanger includes a first passage through which the unexpanded refrigerant passes and a second passage through which the expanded refrigerant passes.

3. The vehicle HVAC system of claim 2, wherein: The control valve unit includes a first control valve configured to allow the refrigerant discharged from the interior condenser to be directed to the exterior heat exchanger or to bypass the exterior heat exchanger.

4. The vehicle HVAC system of claim 3, wherein: The first control valve includes an input port fluidly connected to the interior condenser, a first output port fluidly connected to the first passage of the refrigerant heat exchanger and an outlet of the exterior heat exchanger, and a second output port fluidly connected to an inlet of the exterior heat exchanger.

5. The vehicle HVAC system of claim 4, wherein: The first control valve is configured to allow the input port to selectively communicate with the first output port or the second output port.

6. The vehicle HVAC system of claim 2, wherein: The control valve unit includes a second control valve configured to allow the refrigerant discharged from the interior condenser or the refrigerant discharged from the first passage of the refrigerant heat exchanger to be guided to the water-cooled heat exchanger.

7. The vehicle HVAC system of claim 6, wherein: The second control valve includes a first input port fluidly connected to the interior condenser, a second input port fluidly connected to the first passage of the refrigerant heat exchanger, and an output port fluidly connected to the first passage of the water-cooled heat exchanger.

8. The vehicle HVAC system of claim 7, wherein: The second control valve is configured to allow the first input port or the second input port to selectively communicate with the output port.

9. The vehicle HVAC system of claim 7, wherein: The opening degree of the second control valve is configured to be adjusted in a state where the first input port or the second input port is communicated with the output port.

10. The vehicle HVAC system of claim 2, wherein: The control valve unit includes a third control valve configured to allow the refrigerant exhausted from the interior condenser or the exterior heat exchanger to be guided to the second passage of the refrigerant heat exchanger.

11. The vehicle HVAC system of claim 10, wherein: The third control valve includes a first input port fluidly connected to the interior condenser, a second input port fluidly connected to the exterior heat exchanger, and an output port fluidly connected to an inlet of the second passage of the refrigerant heat exchanger.

12. The vehicle HVAC system of claim 11, wherein: The third control valve is configured to allow the first input port or the second input port to selectively communicate with the output port.

13. The vehicle HVAC system of claim 2, further comprising: a cooling-side expansion valve located on a downstream side of the first passage of the refrigerant heat exchanger; as well as The evaporator is located downstream of the cooling-side expansion valve.

14. The vehicle HVAC system of claim 2, wherein: An inlet of the first passage of the refrigerant heat exchanger is located on the downstream side of the internal condenser and the downstream side of the external heat exchanger; An inlet of the second passage of the refrigerant heat exchanger is located on the downstream side of the interior condenser and the downstream side of the water-cooled heat exchanger; and An outlet of the second passage of the refrigerant heat exchanger is located on an upstream side of the compressor.

15. A vehicle HVAC system for heating, ventilating and air-conditioning a vehicle, comprising: compressor; an internal condenser disposed on a downstream side of the compressor; a refrigerant heat exchanger located between the internal condenser and the compressor, the refrigerant heat exchanger being configured to transfer heat between expanded refrigerant and unexpanded refrigerant in the refrigerant discharged from the internal condenser; a water-cooled heat exchanger disposed on a downstream side of the internal condenser and configured to transfer heat between the refrigerant and a coolant circulating in a coolant system; an external heat exchanger disposed on a downstream side of the internal condenser and configured to transfer heat between the refrigerant and ambient air, the water-cooled heat exchanger and the external heat exchanger being connected in parallel to a refrigerant circulation path; as well as A control valve unit is configured to control the flow of the refrigerant between the internal condenser, the water-cooled heat exchanger, the external heat exchanger, and the refrigerant heat exchanger and the expansion and / or non-expansion of the refrigerant.

16. The vehicle HVAC system of claim 15, wherein: The refrigerant heat exchanger includes a first passage through which the unexpanded refrigerant passes and a second passage through which the expanded refrigerant passes.

17. The vehicle HVAC system of claim 16, wherein: The control valve unit includes a first control valve configured to allow the refrigerant discharged from the internal condenser to be directed to the external heat exchanger or to bypass the external heat exchanger; the first control valve comprising an input port fluidly connected to the internal condenser, a first output port fluidly connected to the first passage of the refrigerant heat exchanger and an outlet of the external heat exchanger, and a second output port fluidly connected to an inlet of the external heat exchanger; and The first control valve is configured to allow the input port to selectively communicate with the first output port or the second output port.

18. The vehicle HVAC system of claim 16, wherein: the control valve unit including a second control valve configured to allow the refrigerant discharged from the internal condenser or the refrigerant discharged from the first passage of the refrigerant heat exchanger to be guided to the water-cooled heat exchanger; the second control valve including a first input port fluidly connected to the internal condenser, a second input port fluidly connected to the first passage of the refrigerant heat exchanger, and an output port fluidly connected to the first passage of the water-cooled heat exchanger; The second control valve is configured to allow the first input port or the second input port to selectively communicate with the output port; and The opening degree of the second control valve is configured to be adjusted in a state where the first input port or the second input port is communicated with the output port.

19. The vehicle HVAC system of claim 16, wherein: the control valve unit including a third control valve configured to allow the refrigerant exhausted from the interior condenser or the exterior heat exchanger to be guided to the second passage of the refrigerant heat exchanger; the third control valve including a first input port fluidly connected to the interior condenser, a second input port fluidly connected to the exterior heat exchanger, and an output port fluidly connected to an inlet of the second passage of the refrigerant heat exchanger; and The third control valve is configured to allow the first input port or the second input port to selectively communicate with the output port.

20. The vehicle HVAC system of claim 16, further comprising: a cooling-side expansion valve located on a downstream side of the first passage of the refrigerant heat exchanger; as well as The evaporator is located downstream of the cooling-side expansion valve.

Images