KR20220036260A - Vehicle thermal management system - Google Patents

Abstract

The present invention provides an air conditioning subsystem including an evaporator, a compressor, a condenser, and a refrigerant loop fluidly connected to a first expansion valve disposed upstream of the evaporator, and a battery cooling subsystem including a battery coolant loop fluidly connected to the battery. A thermal management system for a vehicle including a system, a battery chiller configured to transfer heat between a branch line branched from the refrigerant loop and the battery coolant loop, and a second expansion valve disposed upstream of the battery chiller on the branch line. As a dehumidification method, during dehumidifying operation of the air conditioning subsystem, the compressor is maintained at a constant RPM by a controller, and the flow rate of the refrigerant flowing into the evaporator is reduced when the evaporator temperature is less than the target evaporator temperature, and the target evaporator temperature is lower than the target evaporator temperature. The evaporator temperature may be an optimal evaporator temperature suitable for dehumidification of the air conditioning subsystem.

Description

Dehumidification method for vehicle thermal management system {VEHICLE THERMAL MANAGEMENT SYSTEM}

The present invention relates to a dehumidifying method for a vehicle thermal management system, and more specifically, to a dehumidifying method for a vehicle thermal management system that can keep the compressor of the air conditioning subsystem constant during dehumidifying the vehicle interior.

Recently, as interest in energy efficiency and environmental pollution issues grows day by day, there is a demand for the development of eco-friendly vehicles that can substantially replace internal combustion engine vehicles. These eco-friendly vehicles are usually electric vehicles or engines powered by fuel cells or electricity. It is divided into hybrid vehicles that are driven using batteries.

An electric vehicle includes a thermal management system, and the thermal management system includes a power train cooling subsystem that cools the electric motor and electronic components, a battery cooling subsystem that cools the battery, and the vehicle's cooling subsystem. It may include an air conditioning subsystem (HVAC subsystem) that heats or cools the air in the passenger compartment.

The air conditioning subsystem includes an evaporator, heater core, and air mixing door disposed within the air conditioning duct. The air conditioning duct has an inlet through which air flows in, and a plurality of outlets through which air is discharged into the passenger compartment. The evaporator is configured to cool the air, the heater core is configured to heat the air flowing into the passenger compartment, and an air mixing door (also referred to as a 'temperature door') is disposed between the evaporator and the heater core. . The evaporator is placed upstream of the air mixing door, and the heater core is placed downstream of the air mixing door. The air mixing door is configured to control the temperature of the air flowing into the passenger compartment by controlling the flow rate of air passing through the heater core.

To maintain the comfort of the passenger compartment of a vehicle, dehumidification is necessary, and dehumidification of the passenger compartment can be achieved by lowering the temperature of the evaporator below a certain temperature and condensing moisture in the air through the dehumidifying operation of the air conditioning subsystem. During the dehumidification operation of the thermal management system, even if the compressor operates at the minimum RPM, a flow rate of refrigerant exceeding that required for dehumidification flows into the evaporator, which may cause the evaporator to be supercooled below 0°C and freeze. In order to prevent overcooling or freezing of the evaporator, the compressor can be controlled to cycle on and off periodically.

However, as the compressor is periodically turned on and off, a lot of noise is generated, and the temperature of the evaporator rises while the compressor is turned off, so the dehumidifying effect is reduced. As the temperature fluctuation of the inner condenser increased and indoor temperature controllability deteriorated, the PTC heater in the air conditioning duct needed to operate, which had the disadvantage of lowering fuel efficiency.

The matters described in this background art section are written to enhance understanding of the background of the invention, and may include matters that are not prior art already known to those skilled in the art in the field to which this technology belongs.

The present invention was conceived in consideration of the above points, and relates to a dehumidification method for a vehicle thermal management system that can keep the RPM of the compressor of the air conditioning subsystem constant during dehumidification of the vehicle interior.

An embodiment of the present invention for achieving the above object includes an air conditioning subsystem including an evaporator, a compressor, a condenser, and a refrigerant loop fluidly connected to a first expansion valve disposed upstream of the evaporator, and a battery. a battery cooling subsystem including a fluidly connected battery coolant loop; a battery chiller configured to transfer heat between a branch line branched from the coolant loop and the battery coolant loop; and an upstream side of the battery chiller on the branch line. A dehumidifying method for a vehicle thermal management system including a second expansion valve disposed, wherein during dehumidifying operation of the air conditioning subsystem, the compressor is maintained at a constant RPM by a controller, and the evaporator is dehumidified when the evaporator temperature is less than the target evaporator temperature. The flow rate of refrigerant flowing into the system is reduced, and the target evaporator temperature may be an optimal evaporator temperature suitable for dehumidification of the air conditioning subsystem.

When the evaporator temperature is greater than the target evaporator temperature, the flow rate of refrigerant flowing into the evaporator may be increased.

The second expansion valve is configured to have a variable opening rate, and when the evaporator temperature is less than the target evaporator temperature, the flow rate of the refrigerant flowing into the battery chiller is increased by increasing the opening rate of the second expansion valve. At the same time, the flow rate of refrigerant flowing into the evaporator can be reduced.

When the evaporator temperature is less than the target evaporator temperature, the opening rate of the second expansion valve is controlled to be greater than the standard opening rate, and the standard opening rate is the opening rate of the second expansion valve set to maintain the target evaporator temperature. You can.

When the evaporator temperature is greater than the target evaporator temperature, the opening rate of the second expansion valve may be controlled to be below the standard opening rate.

The compressor may be controlled to operate during the dehumidification time at the minimum RPM required for dehumidification operation.

According to the present invention, the RPM of the compressor can be kept constant by varying the flow rate of the refrigerant flowing into the evaporator depending on the temperature of the evaporator during dehumidification operation in the vehicle interior, thereby preventing noise generation in advance and dehumidifying. During operation, the evaporator temperature of the air conditioning subsystem can be kept constant, and by reducing the temperature fluctuation of the inner condenser located within the air conditioning duct, the operation of the PTC heater is not required, improving fuel efficiency.

1 is a diagram illustrating a thermal management system for a vehicle according to an embodiment of the present invention.
Figure 2 is a flow chart illustrating a dehumidification method of a thermal management system for a vehicle according to an embodiment of the present invention.
Figure 3 is a graph showing that the evaporator temperature is maintained constant at the target evaporator temperature when performing the dehumidification method of the thermal management system for a vehicle according to an embodiment of the present invention.
Figure 4 is a graph showing that the RPM of the compressor is maintained constant when performing the dehumidification method of the thermal management system for a vehicle according to an embodiment of the present invention.
Figure 5 is a graph showing the change in the opening rate of the second expansion valve when performing the dehumidification method of the thermal management system for a vehicle according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through illustrative drawings. When adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when describing embodiments of the present invention, if detailed descriptions of related known configurations or functions are judged to impede understanding of the embodiments of the present invention, the detailed descriptions will be omitted.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term. Additionally, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an idealized or excessively formal sense. No.

Referring to FIG. 1, the vehicle thermal management system 10 according to an embodiment of the present invention includes an air conditioning subsystem 11 (HVAC subsystem) that heats or cools the air in the passenger compartment of the vehicle, and a battery 41 that cools the battery 41. It may include a battery cooling subsystem (12) and a power train cooling subsystem (13) that cools the electric motor (51) and its related electrical components (52).

The air conditioning subsystem 11 may include a refrigerant loop 21 through which refrigerant circulates. The refrigerant loop 21 may be fluidly connected to the evaporator 31, the compressor 32, the inner condenser 33, the outer condenser 35, and the first expansion valve 15. In Figure 1, the refrigerant flows sequentially through the evaporator 31, the compressor 32, the inner condenser 33, the outer condenser 35, and the first expansion valve 15, so that the refrigerant circulates in the refrigerant loop 21. You can.

The evaporator 31 may be configured to cool the air by refrigerant cooled by the external condenser 35.

The compressor 32 may be configured to compress the refrigerant received from the evaporator 31. According to one example, the compressor 32 may be an electric compressor driven by electrical energy.

The inner condenser 33 may be configured to heat air by refrigerant received from the compressor 32.

The external condenser 35 may be placed on the front side of the vehicle, and the external condenser 35 may be cooled through external air forcibly blown by the cooling fan 75.

The first expansion valve 15 may be disposed between the outer condenser 35 and the evaporator 31, and in particular, the first expansion valve 15 is disposed on the upstream side of the evaporator 31 to provide airflow from the outer condenser 35. It may be configured to expand the received refrigerant. According to one example, the first expansion valve 15 may be a thermal expansion valve (TXV) with a solenoid. When the first expansion valve 15 is closed, the refrigerant may not flow into the evaporator 31 but only into the battery chiller 37. That is, when the first expansion valve 15 is closed, the air conditioning subsystem 11 is not cooled, and only the battery chiller 37 can be cooled. When the first expansion valve 15 is opened, refrigerant may flow into the evaporator 31. That is, when the first expansion valve 15 is opened, cooling of the air conditioning subsystem 11 can be performed.

The air conditioning subsystem 11 may include an air conditioning duct 30 configured to discharge air toward the passenger compartment of the vehicle, and the evaporator 31 and the inner condenser 33 may be located within the air conditioning duct 30. . The air mixing door 34a may be disposed between the evaporator 31 and the inner condenser 33, and the PTC heater 34b (Positive Temperature Coefficient heater) may be disposed downstream of the inner condenser 33.

The air conditioning subsystem 11 may further include an accumulator 38 disposed between the evaporator 31 and the compressor 32 , and the accumulator 38 may be located downstream of the evaporator 31 . The accumulator 38 may be configured to prevent the liquid refrigerant from flowing into the compressor 32 by separating the liquid refrigerant from the refrigerant received from the evaporator 31.

The air conditioning subsystem 11 may further include a branch line 36 branched from the refrigerant loop 21, and a battery chiller 37 may be fluidly connected to the branch line 36, and the battery chiller 37 may be connected to the branch line 36. ) may be configured to transfer heat between the branch line 36 and the battery coolant loop 22, which will be described later. The battery chiller 37 may include a first coolant passage 37a fluidly connected to the branch line 36 and a second coolant passage 37b fluidly connected to the battery coolant loop 22. Accordingly, the battery chiller 37 can transfer heat between the coolant passing through the second coolant passage 37b and the coolant passing through the first coolant passage 37a. The branch line 36 may be fluidly connected to the accumulator 38, and the refrigerant passing through the branch line 36 may be accommodated in the accumulator 38.

The second expansion valve 16 may be disposed on the upstream side of the battery chiller 37 on the branch line 36, and the second expansion valve 16 may be configured to expand the refrigerant received from the external condenser 35. there is. According to one example, the second expansion valve 16 may be an electronic expansion valve (EXV) whose opening rate is variable by the controller 100. As the opening rate of the second expansion valve 16 varies, the flow rate of refrigerant flowing into the battery chiller 37 may vary. For example, when the opening rate of the second expansion valve 16 is greater than the standard opening rate, the flow rate of refrigerant flowing into the battery chiller 37 may increase relatively than the standard flow rate, and the opening rate of the second expansion valve 16 may be increased relatively. If the rate is less than the standard opening rate, the flow rate of the refrigerant flowing into the battery chiller 37 may be similar to the standard flow rate or may be relatively reduced compared to the standard flow rate. Here, the standard opening rate may be the opening rate of the second expansion valve 16 that can maintain the target evaporator temperature. The standard flow rate may be the flow rate of refrigerant flowing into the battery chiller 37 when the second expansion valve 16 is opened at the standard opening rate. Accordingly, when the second expansion valve 16 is opened at the standard opening rate, the refrigerant can flow into the battery chiller 37 at the corresponding standard flow rate.

As the opening rate of the first expansion valve 15 and the opening rate of the second expansion valve 16 are adjusted by the controller 100, the refrigerant will be distributed at a certain ratio to the evaporator 31 and the battery chiller 37. Through this, the cooling of the air conditioning subsystem 11 and the cooling of the battery chiller 37 can be performed simultaneously or selectively.

The air conditioning subsystem 11 may further include a refrigerant bypass line 39 fluidly connected to the branch line 36, and the refrigerant bypass line 39 allows the refrigerant passing through the branch line 36 to be stored in the accumulator. It may be configured to bypass (38) and compressor (32). Specifically, the inlet of the refrigerant bypass line 39 may be connected to a point between the battery chiller 37 and the accumulator 38 on the branch line 36, and the outlet of the refrigerant bypass line 39 may be connected to the refrigerant loop ( 21) may be connected to a point between the outer condenser 35 and the water-cooled heat exchanger 70. That is, the refrigerant bypass line 39 can join the refrigerant loop 21 from the branch line 36.

The air conditioning subsystem 11 may further include a first three-way valve 61 disposed at the outlet of the refrigerant bypass line 39. That is, the first three-way valve 61 may be disposed at the confluence point between the outlet of the refrigerant bypass line 39 and the refrigerant loop 21. The refrigerant passing through the branch line 36 can selectively flow through the refrigerant bypass line 39 by the switching operation of the first three-way valve 61.

The battery cooling subsystem 12 may include a battery coolant loop 22 through which coolant circulates. The battery coolant loop (22) includes a battery (41), a heater (42), a battery chiller (37), a second circulation pump (45), a battery radiator (43), a reservoir tank (48), and a first circulation pump (44). ) can be fluidly connected to. In Figure 1, the coolant is supplied to the battery 41, heater 42, battery chiller 37, second circulation pump 45, battery radiator 43, reservoir tank 48, and first circulation pump 44. By sequentially flowing, the coolant can circulate in the battery coolant loop 22.

The battery 41 may have a coolant passage through which coolant passes inside or outside, and the battery coolant loop 22 may be fluidly connected to the coolant passage of the battery 41.

The heater 42 may be disposed between the battery chiller 37 and the battery 41, and the heater 42 may heat the coolant circulating in the battery coolant loop 22 to warm up the coolant. According to one example, the heater 42 may be a water heater that heats coolant by heat exchange with a high-temperature fluid. According to another example, heater 42 may be an electric heater.

The battery radiator 43 may be placed on the front side of the vehicle, and the battery radiator 43 may be cooled through outdoor air forcibly blown by the cooling fan 75. Battery radiator 43 may be adjacent to external condenser 35.

The first circulation pump 44 may be disposed between the battery radiator 43 and the battery 41, and the first circulation pump 44 may be configured to circulate coolant.

The second circulation pump 45 may be disposed between the battery radiator 43 and the battery chiller 37, and the second circulation pump 45 may be configured to circulate coolant.

The battery cooling subsystem 12 includes a first battery bypass line 46 and a second battery bypass line 47 that guide coolant from the upstream side of the first circulation pump 44 to the downstream side of the battery chiller 37. It can be included.

The inlet of the first battery bypass line 46 may be connected to a point between the first circulation pump 44 and the battery radiator 43 on the battery coolant loop 22. Specifically, the inlet of the first battery bypass line 46 may be connected to a point between the first circulation pump 44 and the reservoir tank 48 on the battery coolant loop 22. The outlet of the first battery bypass line 46 may be connected to a point between the battery chiller 37 and the second circulation pump 45 on the battery coolant loop 22.

The inlet of the second battery bypass line 47 may be connected to a point between the inlet of the first battery bypass line 46 and the battery radiator 43 on the battery coolant loop 22. Specifically, the inlet of the second battery bypass line 47 may be connected to a point between the inlet of the first battery bypass line 46 and the reservoir tank 48 on the battery coolant loop 22. The outlet of the second battery bypass line 47 may be connected to a point between the outlet of the first battery bypass line 46 and the second circulation pump 45 on the battery coolant loop 22.

The first battery bypass line 46 and the second battery bypass line 47 may be parallel to each other.

The battery cooling subsystem 12 may further include a second three-way valve 62 disposed at the outlet of the first battery bypass line 46. That is, the second three-way valve 62 may be disposed at the confluence point between the outlet of the first battery bypass line 46 and the battery coolant loop 22. The first circulation pump 44 and the second circulation pump 45 can be selectively operated by the switching operation of the second three-way valve 62. Accordingly, the coolant can selectively pass through the first battery bypass line 46 and the second battery bypass line 47 by the switching operation of the second three-way valve 62. The coolant passing through the first battery bypass line 46 bypasses the battery radiator 43, and the coolant flows through the battery 41, heater 42, and battery chiller 37 by the first circulation pump 44. It can be passed sequentially. Coolant passing through the second battery bypass line 47 may sequentially pass through the second circulation pump 45 and the battery radiator 43.

The reservoir tank 48 may be disposed between the battery radiator 43 and the first circulation pump 44.

The powertrain cooling subsystem 13 may include a powertrain coolant loop 23 through which coolant circulates. The powertrain coolant loop 23 can be fluidly connected to electrical components 52 such as the electric motor 51 and inverter, the powertrain radiator 53, the third circulation pump 54, and the reservoir tank 56. . In Figure 1, the coolant sequentially flows through the electric motor 51, the electrical components 52, the third circulation pump 54, the reservoir tank 56, and the powertrain radiator 53, so that the coolant flows through the powertrain coolant loop ( 23) can be cycled.

The electric motor 51 may have a coolant passage through which coolant passes inside or outside the electric motor 51, and the powertrain coolant loop 23 may be fluidly connected to the coolant passage of the electric motor 51.

The electrical component 52 may be one or more electrical components related to driving the electric motor 51, such as an inverter, OBC, LDC, etc.

The powertrain radiator 53 may be placed on the front side of the vehicle, and the powertrain radiator 53 may be cooled through outdoor air forcibly blown by the cooling fan 75. The outer condenser 35, battery radiator 43, and powertrain radiator 53 may be placed adjacent to each other on the front side of the vehicle, and the cooling fan is connected to the outer condenser 35, battery radiator 43, and powertrain radiator. It can be placed on the rear side of (53).

The third circulation pump 54 may be placed upstream of the electric motor 51 and the electrical components 52, and the third circulation pump 54 is configured to circulate coolant on the powertrain coolant loop 23. It can be.

The powertrain cooling subsystem 13 may further include a powertrain bypass line 55 that guides coolant from the downstream of the electric motor 51 to the upstream of the third circulation pump 54. The inlet of the powertrain bypass line 55 may be connected to a point between the electric motor 51 and the powertrain radiator 53 on the powertrain coolant loop 23. The outlet of the powertrain bypass line 55 may be connected to a point between the reservoir tank 56 and the electric motor 51 on the powertrain coolant loop 23. Specifically, the outlet of the powertrain bypass line 55 may be connected to a point between the reservoir tank 56 and the electrical component 52 on the powertrain coolant loop 23.

The powertrain cooling subsystem 13 may further include a third three-way valve 63 disposed at the outlet of the powertrain bypass line 55, and the coolant is used for the operation of the third three-way valve 63. The powertrain radiator 53 can be bypassed through the powertrain bypass line 55, and the coolant can sequentially pass through the electric motor 51, the third circulation pump 54, and the electrical components 52. You can.

The reservoir tank 56 may be placed on the downstream side of the powertrain radiator 53. In particular, the reservoir tank 56 may be disposed between the powertrain radiator 53 and the third three-way valve 63 on the powertrain coolant loop 23.

The thermal management system 10 according to an embodiment of the present invention further includes a water-cooled heat exchanger 70 disposed between the air conditioning subsystem 11, the battery cooling subsystem 12, and the powertrain cooling subsystem 13. can do.

The thermal management system 10 according to an embodiment of the present invention transfers waste heat from the electric motor 51 and the electrical components 52 of the powertrain cooling subsystem 13 to the air conditioning subsystem 11 and/or the battery cooling subsystem ( 12) may further include a water-cooled heat exchanger 70 configured to recover. Specifically, the water-cooled heat exchanger 70 includes a first coolant passage 71 fluidly connected to the powertrain coolant loop 23, a second coolant passage 72 fluidly connected to the battery coolant loop 22, and , may include a third coolant passage 73 fluidly connected to the refrigerant loop 21.

The refrigerant loop 21 of the air conditioning subsystem 11 may further include a third expansion valve 17 disposed between the inner condenser 33 and the water-cooled heat exchanger 70. The third expansion valve 17 may be a fully open electronic expansion valve (full open type EXV). The third expansion valve 17 may be configured to have a variable opening rate by the controller 100, and as the opening rate of the third expansion valve 17 is varied, the refrigerant flowing into the third coolant passage 73 The flow rate may be variable.

The first three-way valve 61 may be disposed between the outer condenser 35 and the water-cooled heat exchanger 70 on the refrigerant loop 21.

The thermal management system 10 for a vehicle according to an embodiment of the present invention includes an outside temperature sensor 81 that measures the outside air temperature of the vehicle, a humidity sensor 82 that measures the humidity in the passenger compartment of the vehicle, and an air conditioning subsystem 11. A refrigerant temperature/pressure sensor 83 that measures the temperature and pressure of the refrigerant, a pressure sensor 84 configured to check for malfunction by measuring the pressure of the refrigerant loop 21, and a temperature of the evaporator 31. It may include an evaporator temperature sensor 85. The pressure sensor 84 detects that the pressure of the refrigerant loop 21 is lowered below the reference pressure, thereby confirming that the refrigerant is reduced or absent within the refrigerant loop 21. If the pressure of the refrigerant loop 21 exceeds the standard pressure, the pressure sensor 84 can confirm that a part of the refrigerant loop 21 is blocked. The controller 100 operates the air conditioning subsystem 11 and the battery using the outside temperature sensor 81, humidity sensor 82, refrigerant temperature/pressure sensor 83, pressure sensor 84, and evaporator temperature sensor 85. The operations of the cooling subsystem 12 and the powertrain cooling subsystem 13 can be appropriately controlled.

Figure 2 is a flow chart illustrating a dehumidification method of a thermal management system for a vehicle according to an embodiment of the present invention.

First, it is determined whether the air conditioning subsystem 11 of the vehicle thermal management system 10 is turned on (S1).

When the controller 100 determines that the air conditioning subsystem 11 is turned on, it is determined whether the dehumidifying mode of the air conditioning subsystem 11 is necessary (S2). For example, by comparing the outside temperature of the vehicle with the reference temperature, whether the wipers are operating, the number of passengers in the passenger compartment of the vehicle, the humidity measured by the humidity sensor 82, and whether or not the dehumidification button of the air conditioning subsystem is pressed, etc. You can determine whether it is in dehumidifying mode or not.

If it is determined that the dehumidifying mode of the air conditioning subsystem 11 is necessary, the controller 100 controls the air conditioning subsystem 11 so that the air conditioning subsystem 11 operates in the dehumidifying mode. In particular, while the compressor 32 is driven at a constant RPM, the controller 100 operates the compressor 32 and the first expansion valve ( 15) can be controlled (S3). Referring to FIG. 4, the compressor 32 may be controlled by the controller 100 to be constantly operated at the minimum RPM required for dehumidification during the dehumidification time.

It is determined whether the evaporator temperature measured by the evaporator temperature sensor 85 is less than the target evaporator temperature (T1) (S4). The target evaporator temperature (T1) refers to the optimal evaporator temperature suitable for dehumidification. For example, the target evaporator temperature (T1) may be 1°C.

When the evaporator temperature is less than the target evaporator temperature T1, the evaporator 31 may be excessively cooled, so the opening rate of the second expansion valve 16 is increased by the controller 100 (S5). In particular, by controlling the opening rate of the second expansion valve 16 to be greater than the standard opening rate, the flow rate of the refrigerant flowing into the battery chiller 37 can be increased and at the same time the flow rate of the refrigerant flowing into the evaporator 31 can be reduced. You can. That is, when the evaporator temperature becomes smaller than the target evaporator temperature T1, the opening rate of the second expansion valve 16 relatively increases, so that the flow rate of refrigerant flowing into the evaporator 31 can be relatively reduced. Here, the standard opening rate may be the opening rate of the second expansion valve 16 set to maintain the target evaporator temperature. The standard flow rate may be the flow rate of refrigerant flowing into the battery chiller 37 when the second expansion valve 16 is opened at the standard opening rate.

When the evaporator temperature is greater than the target evaporator temperature (T1), the opening rate of the second expansion valve 16 is reduced by the controller 100 (S6). In particular, by controlling the opening rate of the second expansion valve 16 to be below the standard opening rate, the flow rate of the refrigerant flowing into the battery chiller 37 can be reduced and the flow rate of the refrigerant flowing into the evaporator 31 can be increased. You can. That is, when the evaporator temperature becomes greater than the target evaporator temperature T1, the opening rate of the second expansion valve 16 is relatively reduced, so that the flow rate of refrigerant flowing into the evaporator 31 can be relatively increased.

As described above, when executing the dehumidification method of the vehicle thermal management system 10 according to an embodiment of the present invention, the evaporator temperature can be kept constant at the target evaporator temperature T1 as shown in FIG. 3, and as shown in FIG. 4 The RPM of the compressor 32 may be maintained constant, and as shown in FIG. 5, the opening rate of the second expansion valve 16 may be varied during the dehumidification time.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention.

Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

10: Vehicle thermal management system 11: Air conditioning subsystem
12: Battery cooling subsystem 13: Powertrain cooling subsystem
15: first expansion valve 16: second expansion valve
17: Third expansion valve 21: Refrigerant loop
22: Battery coolant loop 23: Powertrain coolant loop
30: air conditioning duct 31: evaporator
32: compressor 33: inner condenser
35: outer condenser 36: branch line
37: Battery chiller 38: Accumulator
39: Refrigerant bypass line 41: Battery
42: heater 43: battery radiator
44: first circulation pump 45: second circulation pump
46: 1st battery bypass line 47: 2nd battery bypass line
48: reservoir tank 51: electric motor
52: Electrical parts 53: Powertrain radiator
54: Third circulation pump 55: Powertrain bypass line
56: reservoir tank 61: first three-way valve
62: 2nd three-way valve 63: 3rd three-way valve
70: Water-cooled heat exchanger 81: Outdoor temperature sensor
82: Humidity sensor 83: Refrigerant temperature/pressure sensor
84: pressure sensor 85: evaporator temperature sensor

Claims (6)

an air conditioning subsystem including an evaporator, a compressor, a condenser, and a refrigerant loop fluidly connected to a first expansion valve disposed upstream of the evaporator, and a battery cooling subsystem including a battery coolant loop fluidly connected to a battery; A dehumidifying method for a thermal management system for a vehicle including a battery chiller configured to transfer heat between a branch line branched from the refrigerant loop and the battery coolant loop, and a second expansion valve disposed upstream of the battery chiller on the branch line. ,
During dehumidifying operation of the air conditioning subsystem, the compressor is maintained at a constant RPM by a controller,
When the evaporator temperature is less than the target evaporator temperature, the flow rate of the refrigerant flowing into the evaporator is reduced,
A dehumidifying method for a vehicle thermal management system where the target evaporator temperature is the optimal evaporator temperature suitable for dehumidification. In claim 1,
A dehumidifying method for a vehicle thermal management system that increases the flow rate of refrigerant flowing into the evaporator when the evaporator temperature is greater than the target evaporator temperature. In claim 1,
The second expansion valve is configured to have a variable opening rate,
When the evaporator temperature is less than the target evaporator temperature, thermal management for vehicles increases the flow rate of refrigerant flowing into the battery chiller by increasing the opening rate of the second expansion valve and simultaneously reduces the flow rate of refrigerant flowing into the evaporator. Dehumidification method of the system. In claim 3,
When the evaporator temperature is less than the target evaporator temperature, the opening rate of the second expansion valve is controlled to be greater than the standard opening rate, and the standard opening rate is the opening rate of the second expansion valve set to maintain the target evaporator temperature. Dehumidification method for vehicle thermal management system. In claim 4,
When the evaporator temperature is greater than the target evaporator temperature, the opening rate of the second expansion valve is controlled to be less than or equal to the standard opening rate. In claim 1,
A dehumidifying method for a vehicle thermal management system in which the compressor is controlled to operate at the minimum RPM required for dehumidification during the dehumidification time.

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