WO2022070796A1

WO2022070796A1 - Vehicle heat management system

Info

Publication number: WO2022070796A1
Application number: PCT/JP2021/032765
Authority: WO
Inventors: 麗娜劉; 錦兪; 博文張; 誠司伊藤
Original assignee: 株式会社デンソー
Priority date: 2020-09-30
Filing date: 2021-09-07
Publication date: 2022-04-07
Also published as: CN113547956A

Abstract

A vehicle heat management system of the present invention has a coolant circulation circuit. The coolant circulation circuit has a compressor, and a first heat exchanger provided with a fan. The coolant circulation circuit includes a first bypass and a second bypass that are connected in parallel between the upstream side of the compressor and the downstream side of the first heat exchanger. The first bypass includes a first expander and a second heat exchanger connected in that order. The second bypass includes a second expander, a third heat exchanger for performing heat exchange with a battery, and a third expander, connected in that order. The coolant circulation circuit is further provided with a fourth heat exchanger as an internal heat exchanger thereupon. A control system keeps coolant flowing into the third heat exchanger in a saturated state by controlling the opening degrees of the second expander and the third expander. Consequently, the temperature of the coolant flowing into the third heat exchanger is regulated.

Description

Vehicle heat management system

Cross-reference of related applications

This application is a patent application filed in the People's Republic of China on September 30, 2020. It is based on X, and the content of the basic application is incorporated by reference as a whole.

This disclosure relates to the vehicle heat management technology field, specifically to the vehicle heat management system.

In order to guarantee the safe operation and life of the power battery of an electric vehicle, it is necessary to cool and heat the power battery to ensure that the power battery operates within an appropriate temperature range. Therefore, when the temperature of the battery is higher than a certain temperature value, it is necessary to cool the battery, and when the temperature is lower than a certain temperature, it is necessary to heat the battery.

In a vehicle heat management system that directly heats and / or cools a battery using a refrigerant, two types of means are usually used for heating the battery in the vehicle heat management system. One is to heat the battery directly using PTC, and the other is to heat the battery using high temperature gas compressed by a compressor.

When heating a battery using PTC, there are currently two main types of PTC on the market, one with feedback adjustment and the other without feedback adjustment. The PTC with feedback adjustment can adjust the thermal output delivered by the PTC based on the temperature of the bottom of the battery. The feedback regulator reduces the PTC thermal output if the temperature at the bottom of the battery is above a certain value. For PTCs without feedback control, the thermal output is constant. The feedback regulator turns off the PTC when the temperature of the bottom of the battery is higher than a certain specified value, and turns on the PTC again when the temperature of the bottom of the battery is lower than a certain value for heating. Therefore, PTC will start and stop frequently. Also, in the case of heating by PTC, the price will be considerably high.

On the other hand, when the battery is directly heated using the high temperature gas compressed by the compressor, the temperature rises when the battery absorbs the heat of the refrigerant, and the temperature drops when the refrigerant dissipates heat. At this time, the temperature difference of the refrigerant at the inlet and outlet of the heating plate of the battery reaches 30 to 40 degrees, and the temperature difference on the surface of the battery exceeds the permissible value (generally 5 ° C). If the temperature difference between the batteries is too large, the life and efficiency of the power battery may be significantly affected.

In view of the above problems, an object of this disclosure is to provide a vehicle heat management system capable of realizing a plurality of heat management modes including soaking cooling and soaking heating of a battery.

In this disclosure, a vehicle heat management system having a refrigerant circulation circuit is provided, and the refrigerant circulation circuit includes a compressor, a first heat exchanger in which a fan is installed, and an upstream side of the compressor and a first heat exchange. It includes a first bypass and a second bypass connected in parallel to the downstream side of the vessel, the first bypass includes a first inflator and a second heat exchanger connected in sequence, and the second bypass connects in sequence. A third heat exchanger for heat exchange between the second expansion device and the battery, and a third expansion device are included, and a fourth heat exchanger is further installed on the refrigerant circulation circuit. 4 The heat exchanger causes heat exchange between the refrigerant flowing out from the first heat exchanger and the refrigerant flowing toward the compressor, or a part of the refrigerant flowing out from the first heat exchanger and flowing toward the compressor. By having a part of the refrigerant exchange heat and controlling the opening degree of the second expansion device and the third expansion device, the refrigerant flowing into the third heat exchanger is saturated, thereby making the third heat exchanger saturated. Adjust the temperature of the refrigerant flowing into.

Further, in this disclosure, the first bypass and the second bypass are connected in parallel between the first confluence point located on the downstream side of the first heat exchanger and the second confluence point located on the upstream side of the compressor. The fourth heat exchanger is located between the first heat exchanger and the first confluence, and between the second confluence and the compressor, and is the first confluence from the first heat exchanger. It can be used to exchange heat between the refrigerant flowing toward the point and the refrigerant flowing from the second confluence toward the compressor.

Further, in this disclosure, the first bypass and the second bypass are connected in parallel between the first confluence point located on the downstream side of the first heat exchanger and the second confluence point located on the upstream side of the compressor. The fourth heat exchanger is located between the first confluence point and the second expansion device and between the third expansion device and the second confluence point, and is located between the first confluence point and the second expansion device. It can be used to exchange heat between the refrigerant flowing into the device and the refrigerant from the third expansion device toward the second confluence.

Further, in this disclosure, the first expansion device is configured independently by an electronic expansion valve or a mechanical expansion valve having a shut-off function, or a mechanical temperature expansion valve and a mechanical temperature expansion valve on the first bypass. It can be configured with a solenoid valve mounted on the upstream side.

Further, in this disclosure, the second expansion device is configured independently by an electronic expansion valve or a mechanical expansion valve having a shut-off function, or a mechanical temperature expansion valve and a mechanical temperature expansion valve on the second bypass. It can be configured with a solenoid valve mounted on the upstream side.

Also, in this disclosure, a gas-liquid separator can be installed on the inlet side of the compressor. As a result, the gas and liquid of the refrigerant can be separated by the gas-liquid separator, and the compressor can be prevented from being damaged.

With this disclosure, it is possible to realize uniform heating and uniform cooling of the battery with a simple and low-cost circuit structure. As a result, efficient operation and service life of the battery can be guaranteed, and the influence on the service life due to the excessive surface temperature difference in the process of heating or cooling the battery can be prevented. It is possible to perform four different thermal management modes: single cooling inside the car, single cooling of the battery, heating of the battery, and simultaneous cooling of the inside of the car and the battery.

1A and 1B are structural schematic views of a vehicle heat management system based on the first embodiment of the disclosure, FIG. 1A is a structural schematic diagram of a vehicle heat management system, and FIG. 1B is a first expansion in a vehicle heat management system. A specific installation example of the device and the second expansion device, (c) is a structural schematic diagram when a gas-liquid separator is installed in the vehicle heat management system. FIG. 2 is a diagram showing an independent cooling circulation of a battery by the vehicle heat management system of the first embodiment shown in FIG. 1, and FIG. 2A is a schematic structural diagram of the vehicle heat management system during a battery independent cooling circulation. b) is a pressure enthalpy diagram of the battery independent cooling circulation. FIG. 3 is a diagram showing battery heating circulation by the vehicle heat management system of the first embodiment shown in FIG. 1, where (a) is a schematic structural diagram of the vehicle heat management system during battery heating circulation, (b). Is a pressure enthalpy diagram of battery heating circulation. FIG. 4 is a diagram showing an air-conditioning independent cooling circulation by the vehicle heat management system of the first embodiment shown in FIG. 1, and FIG. 4A is a structural schematic diagram of the vehicle heat management system during an air-conditioning independent cooling circulation, (b). ) Is a pressure enthalpy diagram of the air conditioning single cooling circulation. FIG. 5 is a diagram showing air conditioning and battery cooling circulation by the vehicle heat management system of the first embodiment shown in FIG. 1, and FIG. 5A is an outline of the structure of the vehicle heat management system during air conditioning and battery cooling circulation. The figure (b) is a pressure enthalpy diagram of circulation in which air conditioning and a battery operate at the same time. 6A and 6B are structural schematic views of a vehicle heat management system based on the second embodiment of the disclosure, FIG. 6A is a structural schematic diagram of the vehicle heat management system, and FIG. 6B is a first expansion in the vehicle heat management system. This is a specific installation example of the device and the second expansion device. FIG. 7 is a diagram showing an air-conditioning independent cooling circulation by the vehicle heat management system of the second embodiment shown in FIG. 6, and FIG. 7A is a structural schematic diagram of the vehicle heat management system during an air-conditioning independent cooling circulation, (b). ) Is a pressure enthalpy diagram during cooling and circulation of air conditioning alone. FIG. 8 is a diagram showing that air conditioning and cooling circulation of the battery are simultaneously performed by the vehicle heat management system of the second embodiment shown in FIG. 6, and FIG. 8A is a diagram showing the air conditioning of the vehicle heat management system and the battery. The structural schematic diagram at the time of simultaneous cooling circulation, (b) is the pressure enthalpy diagram at the time of simultaneous cooling circulation of an air conditioner and a battery. FIG. 9 is a schematic structural diagram of a vehicle heat management system based on the third embodiment of the disclosure.

In the following, this disclosure will be further described by linking the drawings with the embodiments. It should be understood that the drawings and embodiments merely explain this disclosure and do not limit this disclosure.

Here, the vehicle heat management system that can realize soaking cooling and soaking heating of the battery is open to the public. The vehicle heat management system can be applied to vehicles such as PHEV (Plug-in Hybrid Electric Vehicle, plug-in hybrid electric vehicle) and pure EV (Electric Vehicle, electric vehicle). Hereinafter, specific embodiments of this disclosure will be described in more detail in connection with the drawings.

1st Embodiment FIG. 1 is a structural schematic diagram of a vehicle heat management system based on the first embodiment of this disclosure. As shown in FIG. 1 (a), the vehicle heat management system of the first embodiment has a refrigerant circulation circuit 300. The refrigerant circulation circuit 300 includes a compressor 20 and a first heat exchanger 21. The refrigerant circulation circuit 300 includes a first bypass 301 and a second bypass 302 connected in parallel between the upstream of the compressor 20 and the downstream of the first heat exchanger 21. The first heat exchanger 21 is installed downstream of the compressor 20. The first heat exchanger 21 is a condenser for heat exchange between high temperature and high pressure refrigerant gas discharged from the compressor 20 and air. A fan 32 is installed on the capacitor 21. When the fan 32 is started, the condenser 21 exchanges heat between the refrigerant and the air blown out by the fan to dissipate heat. The condenser 21 is used only as a fluid passage because the condenser 21 does not function when the fan 32 is stopped.

The first bypass 301 is mainly used for cooling the inside of the vehicle, and the first expansion device 34 and the second heat exchanger 25 are connected in this order, and the downstream of the condenser 21 and the compressor 20 are connected in this order. It is connected to the upstream of. Therefore, the compressor 20, the condenser 21, the first expansion device 34, and the second heat exchanger 25 form a cooling circuit that cools the inside of the vehicle along the flow direction of the refrigerant in this order. In the present embodiment, the first expansion device 34 is provided by an electronic expansion valve (EXV; Electrical Expansion Valve) or a mechanical expansion valve (Shut-off TXV; Shut-off Thermal Expansion Valve) having a shut-off function. Can be done. The first expansion device 34 also has a switching function and a diaphragm function at the same time. As shown in FIG. 1B, the first expansion device 34 can also be configured by connecting the switching valve 23 and the first expansion valve 24 in series. The first expansion device 34 may be independently configured by an electronic expansion valve or a mechanical expansion valve having a shut-off function. Alternatively, the first expansion device 34 may consist of a mechanical temperature expansion valve and a solenoid valve mounted upstream of the mechanical temperature expansion valve on the first bypass.

The switching valve 23 may be a solenoid valve that can be opened and closed, and is mainly used for controlling the opening and closing of the first bypass 301. The first expansion valve 24 may be a mechanical temperature expansion valve (TXV; Thermal Expansion Valve). The opening degree of the expansion valve 24 of the first expansion valve 24 is voluntarily controlled based on the degree of superheat of the refrigerant, and is mainly used to throttle and reduce the pressure of the inflowing refrigerant gas. The second heat exchanger 25 is an evaporator that exchanges heat between air and the refrigerant, and the refrigerant flowing out from the first expansion valve 24 after the temperature drop is lowered absorbs the heat of the air in the evaporator 25 and has a low temperature and low pressure. It becomes a gas and cools the inside of the car.

The second bypass 302 is configured by connecting the second expansion device 35, the third heat exchanger 27 installed below the battery 29, and the third expansion valve 28 as the third expansion device in this order. .. The second bypass 302 is connected between the downstream of the capacitor 21 and the upstream of the compressor 20 in this order. The compressor 20, the capacitor 21, the second expansion device 35, the third heat exchanger 27, and the third thermal expansion valve 28 heat or cool the battery 29 along the flow direction of the refrigerant in this order. It constitutes a management circuit. In the present embodiment, the second expansion device 35 may be an electronic expansion valve as shown in FIG. 1 (b) or a second expansion valve 26 as a mechanical expansion valve having a shut-off function. At the same time, the second expansion device 35 also has a switching function and a diaphragm function. The second expansion device 35 may also be configured by connecting a solenoid valve and a temperature expansion valve such as the first expansion device 34 described above in series.

The third heat exchanger 27 is a battery heat exchanger and is installed below the power battery 29. The battery heat exchanger 27 realizes cooling and heating of the battery 29 by exchanging the amount of heat of the bottom surface of the battery 29 with the refrigerant circulating inside. When the temperature of the refrigerant is lower than the temperature of the battery 29, the refrigerant absorbs the amount of heat of the battery 29 and realizes the function of cooling the battery 29. When the temperature of the refrigerant is higher than the temperature of the battery 29, the refrigerant dissipates heat to the battery 29, and the battery 29 absorbs the heat of the refrigerant to realize the function of heating the battery 29.

The second expansion valve 26 is installed upstream of the battery heat exchanger 27. The second expansion valve 26 is mainly used to throttle the inflowing refrigerant gas to reduce the pressure to obtain a medium-temperature, medium-pressure liquid refrigerant. The second expansion valve 26 may be an integrated expansion valve such as an electronic expansion valve that can realize a switching function and a throttle function, for example. The third expansion valve 28 is mainly used to squeeze the refrigerant discharged from the battery heat exchanger 27 twice to obtain a low-temperature low-pressure liquid. By controlling the opening degree of the second expansion valve 26 and the third expansion valve 28, the refrigerant flowing into the third heat exchanger 27 is always saturated (that is, a gas-liquid mixed state) and flows into the battery heat exchanger 27. The temperature of the refrigerant can be adjusted.

As described above, the first confluence point 30 is formed on the downstream side of the condenser 21 on the refrigerant circulation circuit 300 at the refrigerant inlet ends of the first bypass 301 and the second bypass 302. A second confluence 31 is formed at the refrigerant outlet ends of the first bypass 301 and the second bypass 302 on the upstream side of the compressor 20 on the refrigerant circulation circuit 300. As a result, the first bypass 301 and the second bypass 302 are collectively installed in parallel in the refrigerant circulation circuit 300.

Further, in this disclosure, the heat exchanger 22 is further installed on the refrigerant circulation circuit 300. The heat exchanger 22 is mainly used to exchange heat between the refrigerant flowing out of the condenser 21 and the refrigerant flowing toward the compressor 20. Alternatively, the heat exchanger 22 is used to exchange heat between a part of the refrigerant flowing out of the condenser 21 and a part of the refrigerant flowing toward the compressor 20. The heat exchanger 22 is also referred to as a fourth heat exchanger. The heat exchanger 22 is also an internal heat exchanger in the refrigerant circulation circuit 300.

In the first embodiment, as shown in FIG. 1, the heat exchanger 22 has a portion between the capacitor 21 and the first confluence 30 and a portion between the compressor 20 and the second confluence 31. It is installed in between. At this time, the heat exchanger 22 causes all the refrigerants flowing out from the condenser 21 and all the refrigerants flowing toward the compressor 20 to exchange heat. More specifically, the heat exchanger 22 causes heat exchange between the first refrigerant and the second refrigerant. The first refrigerant is a high temperature and high pressure refrigerant. The first refrigerant is a refrigerant that flows from the condenser 21 into the first bypass 301 and / or the second bypass 302. That is, the first refrigerant is a refrigerant that flows into the first confluence 30. The second refrigerant is a low temperature low pressure refrigerant. The second refrigerant is a refrigerant that flows from the first bypass 301 and / or the second bypass 302 toward the compressor 20. That is, the second refrigerant is a refrigerant that has flowed out from the second confluence 31 and has not reached the compressor 20. The specific situation will be described later, but this causes the relatively high temperature and high pressure refrigerant flowing out through the capacitor 21 to dissipate heat. The temperature of the high temperature and high pressure refrigerant drops. As a result, the high pressure refrigerant may acquire supercooling. The low-temperature low-pressure liquid refrigerant flowing out from the second confluence 31 absorbs heat and becomes a low-temperature low-pressure gas. As a result, the low pressure refrigerant may acquire a degree of superheat. The heat exchanger 22 can contribute to enhancing the performance of the entire system.

Further, as shown in FIG. 1 (c), gas-liquid separation is further separated between the heat exchanger 22 and the compressor 20, specifically, between the outlet of the heat exchanger 22 and the inlet of the compressor 20. A vessel 36 can also be installed. The role of the gas-liquid separator 36 is to separate gas and liquid. The liquid refrigerant is stored in the tank of the gas-liquid separator 36, and the refrigerant gas enters the compressor 20. As a result, it is possible to prevent the compressor 20 from being damaged due to a liquid impact when the compressor 20 sucks in the liquid refrigerant.

The vehicle heat management system can realize four different circulation modes. The vehicle heat management system provides a first mode, a second mode, a third mode, and a fourth mode. The first mode is a circulation state for cooling the battery alone. The second mode is a circulating state in which the battery is heated. The third mode is a circulation state that independently provides a cooling function for air conditioning applications. The third mode is also referred to as an in-vehicle temperature drop state. The fourth mode is a circulating state that provides cooling functions for both air conditioning and the battery. The fourth mode is also called a simultaneous progress state of air conditioning cooling and battery cooling. Hereinafter, the above four types of operation modes will be described in detail with reference to FIGS. 2 to 5 by taking the vehicle heat management system shown in FIG. 1 (b) as an example.

The vehicle heat management system includes a control system 500. The control system 500 controls a plurality of variable elements of the refrigerant circulation circuit 300 so as to selectively provide the plurality of circulation modes. Multiple variable elements include electric expansion valves, solenoid valves, fan motors, and the like. The control system 500 includes a plurality of input devices for inputting an operating state of the refrigerant circulation circuit 300, a temperature environment, and the like. The control system 500 includes at least one processor 510. The processor 510 may be a semiconductor circuit that executes a program recorded in internal memory or external memory. The processor 510 may be a semiconductor circuit including a digital circuit corresponding to a program. Digital circuits may be referred to by names such as gate arrays or FPGAs.

Battery independent cooling circulation state FIG. 2 is a diagram showing a first mode by the vehicle heat management system of the first embodiment. (A) is a structural schematic diagram in the first mode of the vehicle heat management system. (B) is a pressure enthalpy diagram in the first mode. The pipeline shown by the dotted line in the figure indicates that the pipeline is blocked. As should be described here, in the present embodiment, the pressure enthalpy diagram is a curve diagram of pressure and enthalpy value. Pressure enthalpy diagrams are commonly used in the analysis of refrigerants. The pressure enthalpy diagram shows the change in the operation mode when the refrigerant flows in the flow path. The ordinate of the pressure enthalpy diagram is the logarithmic value of absolute pressure (that is, the absolute value of pressure), and the abscissa is the specific enthalpy value. The pressure enthalpy diagram is mainly used to visualize and show the state of the refrigerant at different positions in the system and the state change of the refrigerant. In the control of each mode described later, the state of the refrigerant differs depending on the difference in the opening degree of each valve. The difference in the state of the refrigerant is shown as a position on the pressure enthalpy diagram. The pressure enthalpy diagram in each mode embodies the state the system wants to reach, the target state of control. In the following, if they are the same, they will not be mentioned repeatedly.

As shown in FIGS. 2A and 2B, in the first mode, the control system 500 turns on the fan 32 to start the capacitor 21, closes the switching valve 23, and opens the second expansion valve 26. ing. At this time, no refrigerant is flowing through the first bypass 301. The high-temperature and high-pressure refrigerant gas compressed by the compressor 20 passes through the condenser 21 and dissipates heat to the outside to become a high-temperature and high-pressure liquid refrigerant. All the heat-dissipated refrigerant passes through the heat exchanger 22 and exchanges heat with the low-temperature low-pressure refrigerant discharged from the second bypass 302 in the heat exchanger 22. All of the refrigerant heat exchanged by the heat exchanger 22 flows into the second bypass 302, whereby the refrigerant is made to perform isobaric heat dissipation, temperature lowering, and supercooling. The opening degree of the second expansion valve 26 is controlled based on the degree of superheat of the refrigerant on the outlet side of the battery heat exchanger 27. For example, if the target superheat is set to 5 ° C, the opening of the second expansion valve 26 will increase when the system superheat exceeds 5 ° C, and the second expansion valve will increase when the system superheat falls below 5 ° C. The opening degree of 26 is reduced. Further, the control system 500 adjusts the rotation speed of the compressor 20 based on the heat exchange amount of the battery heat exchanger 27. Specifically, the control system 500 can detect the temperature of the battery 29 and set the target heat exchange amount Q0 required for the battery heat exchanger 27 based on the detected temperature of the battery 29, and the battery. The higher the temperature, the larger the required target heat exchange amount Q0 is set. Subsequently, the control system 500 calculates the actual heat exchange amount Q of the battery heat exchanger 27, compares it with the target heat exchange amount Q0, and controls the rotation speed of the compressor 20 according to the comparison result. The control system 500 increases the rotation speed of the compressor 20 when Q <Q0, and decreases the rotation speed of the compressor 20 when Q> Q0. The second expansion valve 26 decompresses and expands the refrigerant. The second expansion valve 26 supplies a medium-temperature, medium-pressure, gas-liquid mixed saturated refrigerant slightly lower than the temperature of the battery 29. The refrigerant after being throttled by the second expansion valve 26 enters the battery heat exchanger 27 to absorb heat, and the refrigerant after heat absorption passes through the third expansion valve 28. In the first mode, the third expansion valve 28 is fully opened, so that the throttle is not performed. The refrigerant that has passed through the third expansion valve 28 enters the heat exchanger 22 and absorbs heat for the second time. The low-temperature low-pressure refrigerant gas that has undergone two endothermic processes enters the compressor 20 and completes the first mode.

Since the saturation temperature of the refrigerant under the intermediate pressure is higher than the saturation temperature of the refrigerant under the low pressure, the temperature difference between the refrigerant under the intermediate pressure and the battery 29 is relatively small. The amount of heat of the battery 29 absorbed by the refrigerant under the intermediate pressure is relatively small. By doing so, the pre-evaporation of the refrigerant can be suppressed, and the refrigerant can always absorb heat under the gas-liquid saturation state, so that the surface temperature of the battery 29 is relatively uniform and the temperature difference is small.

In the circulation state of the first mode, it is the refrigerant that exchanges the amount of heat in the heat exchanger 22. As shown in FIGS. 2A and 2B, the high-pressure and high-temperature liquid refrigerant discharged from the capacitor 21 flows into the left side of the heat exchanger 22. The low-temperature low-pressure liquid refrigerant discharged after the battery heat exchanger 27 absorbs heat flows into the right side of the heat exchanger 22. As a result, the heat exchanger 22 realizes supercooling of the refrigerant by radiating heat from the high-temperature and high-pressure liquid refrigerant, and realizes overheating of the refrigerant by absorbing heat from the low-temperature and low-pressure refrigerant. As a result, the endothermic capacity and heat exchange capacity of the refrigerant can be increased, and the performance of the system can be improved.

Battery heating circulation state FIG. 3 is a diagram showing a battery heating circulation by the vehicle heat management system of the first embodiment. (A) is a structural schematic diagram in the second mode of the vehicle heat management system. (B) is a pressure enthalpy diagram in the second mode.

As shown in FIG. 3, in the second mode, the refrigerant is compressed by the compressor 20 to become a high-temperature and high-pressure gas. In the operation mode, since the fan 32 of the condenser 21 is stopped, the condenser 21 at this time is merely a passage for the fluid, and the high-temperature and high-pressure refrigerant gas does not exchange the amount of heat in the condenser 21. In this mode, the control system 500 closes the switching valve 23 and opens the second expansion valve 26, but at this time, no refrigerant is flowing on the first bypass 301. All of the high-temperature and high-pressure refrigerant flowing out of the condenser 21 passes through the heat exchanger 22 and exchanges heat with the refrigerant discharged from the battery heat exchanger 27 in the heat exchanger 22 to dissipate heat for the first time. Go and release some of the heat. The specific amount of heat radiation can be adjusted by the second expansion valve 26 of the second bypass 302.

All of the refrigerant after releasing a part of the amount of heat into the heat exchanger 22 flows into the second bypass 302, and the first throttle is performed in the second expansion valve 26. Here, the opening degree of the second expansion valve 26 is controlled based on the degree of superheat of the refrigerant before entering the second expansion valve 26, and the target degree of superheat can be set to 5 ° C. Further, the opening degree of the third expansion valve 28 is controlled based on the degree of superheat at the inlet of the compressor 20, and the target degree of superheat can be set to 10 ° C. At the same time, the control system 500 controls the rotation speed of the compressor 20 based on the amount of heat required for the battery heat exchanger 27. Specifically, the control system 500 can detect the temperature of the battery 29 and set the target heat exchange amount Q0 required for the battery heat exchanger 27 based on the detected temperature of the battery 29. The control system 500 sets the required target heat exchange amount Q0 larger as the detected temperature is higher. Subsequently, the actual heat exchange amount Q of the battery heat exchanger 27 is calculated and compared with the target heat exchange amount Q0. If Q <Q0, the rotation speed of the compressor 20 is increased, and if Q> Q0, the rotation speed is increased. Reduces the rotation speed of the compressor 20. In this way, the squeezed refrigerant is changed to a liquid in a gas-liquid mixed state having a temperature higher than that of the battery 29. The medium pressure is an intermediate pressure between the high-pressure refrigerant discharged from the compressor 20 and the low-pressure refrigerant discharged after being throttled twice by the third expansion valve 28 described later. The medium-temperature, medium-pressure liquid refrigerant dissipates heat for the second time in the battery heat exchanger 27, and the amount of heat in this portion is absorbed by the battery 29 to realize a temperature rise of the battery. As shown in FIG. 3B, in the heat dissipation process of the refrigerant, the second expansion valve 26 is adjusted so that the refrigerant is always in a saturated state of gas-liquid mixing. Since the saturated refrigerant has the same temperature, it is possible to realize battery heating with a uniform temperature. Finally, the refrigerant that has been radiated twice passes through the third expansion valve 28 on the outlet side of the battery 29 and is used for the second throttle. At this time, the opening degree of the third expansion valve 28 can be controlled based on the degree of superheat of the refrigerant discharged from the heat exchanger 22 toward the compressor 20. The third expansion valve 28 changes the refrigerant into a low-temperature low-pressure liquid, and the low-temperature low-pressure liquid passes through the heat exchanger 22. As a result, in the heat exchanger 22, the refrigerant absorbs the amount of heat to become a low-temperature low-pressure gas, and finally returns to the compressor to complete the circulation in the second mode.

Air-conditioning independent cooling circulation state FIG. 4 is a diagram showing a third mode by the vehicle heat management system of the first embodiment. (A) is a structural schematic diagram in the third mode of the vehicle heat management system. (B) is a pressure enthalpy diagram in the third mode.

As shown in FIGS. 4A and 4B, in the third mode, the control system 500 turns on the fan 32 to start the capacitor 21, closes the second expansion valve 26, and closes the switching valve 23. It is open. The high-temperature and high-pressure refrigerant compressed by the compressor 20 passes through the capacitor 21 and dissipates heat to the outside. All of the heat-dissipated refrigerant passes through the heat exchanger 22 to dissipate heat for the second time. Specifically, the refrigerant after the first heat dissipation by the condenser 21 exchanges heat with the low-temperature low-pressure refrigerant flowing out from the first bypass 301 in the heat exchanger 22, thereby supercooling the refrigerant. It will be realized. Since the second expansion valve 26 is closed and the switching valve 23 is open, all the refrigerant after the two heat dissipation enters the first bypass 301 through the first confluence point 30. That is, no refrigerant flows through the second bypass 302. The refrigerant that has passed through the switching valve 23 enters the first expansion valve 24 and is subjected to throttle expansion. After the throttle, the refrigerant becomes a liquid refrigerant in a gas-liquid mixed state lower than the temperature inside the vehicle, enters the evaporator 25, and absorbs heat to cool the inside of the vehicle. The refrigerant after endothermic enters the heat exchanger 22 through the second confluence 31 and absorbs heat for the second time. The refrigerant gas that has undergone two endothermic processes enters the compressor, and the circulation of the third mode is completed.

In this circulation, it is the refrigerant that exchanges the amount of heat in the heat exchanger 22. As shown in FIGS. 4A and 4B, the high-pressure and high-temperature liquid refrigerant discharged from the capacitor 21 flows into the left side of the heat exchanger 22. The low-temperature low-pressure liquid refrigerant discharged from the evaporator 25 flows into the right side of the heat exchanger 22. In the heat exchanger 22, the high temperature and high pressure liquid refrigerant dissipates heat to realize supercooling of the refrigerant, and the low pressure and low temperature refrigerant absorbs heat to realize overheating of the refrigerant. As a result, the endothermic capacity and heat exchange capacity of the refrigerant can be increased, and the performance of the system can be improved.

Both air-conditioning and battery cooling circulation state FIG. 5 is a diagram showing the circulation of the fourth mode by the vehicle heat management system of the first embodiment. (A) is a structural schematic diagram in the fourth mode of the vehicle heat management system. (B) is a pressure enthalpy diagram in the fourth mode.

As shown in FIGS. 5A and 5B, in the fourth mode, the control system 500 turns on the fan 32 to activate the capacitor 21 and opens the switching valve 23 and the second expansion valve 26. .. The high-temperature and high-pressure refrigerant discharged after being compressed by the compressor 20 passes through the capacitor 21 and dissipates heat for the first time. All of the refrigerant discharged from the condenser 21 passes through the heat exchanger 22. The refrigerant discharged from the evaporator 25 and the battery heat exchanger 27 each absorb heat in the heat exchanger 22 for the second time. At this time, since the switching valve 23 and the second expansion valve 26 are both open, the high-temperature and high-pressure liquid refrigerant discharged from the heat exchanger 22 is divided into two at the first confluence point 30. One of the divided refrigerants enters the first bypass 301 and passes through the evaporator 25 to cool the vehicle interior. The other of the diverted refrigerant passes from the second expansion valve 26 to the battery 29 side to cool the battery.

The refrigerant that has entered the first bypass 301 enters the first expansion valve 24 via the switching valve 23, is throttled and depressurized, and becomes a low-temperature low-pressure gas-liquid mixed refrigerant. The refrigerant after the step-down temperature enters the evaporator 25, absorbs the amount of heat of air in the evaporator 25, becomes a low-temperature low-pressure gas, and flows toward the second confluence 31.

The refrigerant that has passed through the second bypass 302 first throttles through the second expansion valve 26, and controls the opening degree of the second expansion valve 26 based on the amount of heat that the refrigerant transfers to the battery heat exchanger 27. do. Specifically, the target heat exchange amount Q0 required for the battery heat exchanger 27 can be set based on the temperature of the battery 29, and the higher the temperature, the larger the required target heat exchange amount Q0. After that, the actual heat exchange amount Q of the battery heat exchanger 27 is calculated, and the relationship between the actual heat exchange amount Q and the opening area of the second expansion valve 26 is established. When Q> Q0, the valve opening area decreases, and when Q <Q0, the valve opening area increases. As a result, the refrigerant is maintained in a gas-liquid mixed saturated state of medium temperature and medium pressure (at this time, the value of the intermediate pressure is set with respect to the high pressure in the condenser 21 and the low pressure in the evaporator 25), and under the intermediate pressure. The refrigerant in the above absorbs the amount of heat of the battery 29. The saturation temperature of the refrigerant under intermediate pressure is higher than the saturation temperature of the refrigerant under low pressure. Therefore, the temperature difference between the refrigerant under the intermediate pressure and the battery 29 is relatively reduced. As a result, the amount of heat of the battery 29 absorbed by the refrigerant under the intermediate pressure is relatively small. Therefore, since the pre-evaporation of the refrigerant can be suppressed and the refrigerant can always absorb heat under the gas-liquid saturation state, the surface temperature of the battery 29 is relatively uniform and the temperature difference is small. The control system 500 adjusts the pressure value of the refrigerant by controlling the opening degree of the second expansion valve 26. The control system 500 controls the opening degree of the third expansion valve 28 based on the degree of superheat of the refrigerant on the outlet side of the battery heat exchanger 27 to ensure that the refrigerant is always saturated in the endothermic process. Thereby, the control system 500 guarantees that the temperature difference of the battery 29 is within the required range, and realizes uniform temperature cooling of the battery 29.

After that, the refrigerants discharged from the first bypass 301 and the second bypass 302 merge at the second confluence point 31. The combined refrigerant enters the heat exchanger 22 and absorbs heat again to become a low-temperature low-pressure refrigerant gas, and the refrigerant after endothermic finally returns to the compressor 20, thereby completing the circulation of the fourth mode.

2nd Embodiment The vehicle heat management system of the 2nd embodiment has a structure similar to that of the vehicle heat management system of the 1st embodiment. Therefore, the structure of the vehicle heat management system of the second embodiment will be mainly described as being different from the vehicle heat management system of the first embodiment, the same structure will be represented by the same reference numerals, and the description thereof will be omitted.

FIG. 6 is a schematic structural diagram of a vehicle heat management system based on the second embodiment of this disclosure. (A) is a structural schematic diagram of a vehicle heat management system. (B) is a specific installation example of the first expansion device and the second expansion device in the vehicle heat management system. As shown in FIG. 6A, the vehicle heat management system of the second embodiment has a refrigerant circulation circuit 400. The refrigerant circulation circuit 400 includes a compressor 20 and a condenser 21 provided with a fan 32. The refrigerant circulation circuit 400 includes a first bypass 401 and a second bypass 402 that are connected in parallel between the upstream of the compressor 20 and the downstream of the condenser 21. The first bypass 401 is formed by connecting the first expansion device 34 and the second heat exchanger 25 in this order, and the first expansion device 34 has a switching valve 23 as shown in FIG. 6B. The first expansion valve 24 can also be connected in series. The second bypass 402 is configured by connecting a second expansion valve 35, a third heat exchanger 27 installed below the battery 29, and a third expansion valve 28 as a third expansion device in this order. .. Among them, the second expansion device 35 may be an electronic expansion valve as shown in FIG. 6B or a second expansion valve 26 as a mechanical expansion valve having a shut-off function.

As described above, the first confluence point 40 is formed on the downstream side of the condenser 21 on the refrigerant circulation circuit 400 at the refrigerant inlet ends of the first bypass 401 and the second bypass 402. A second confluence 41 is formed at the refrigerant outlet ends of the first bypass 401 and the second bypass 402 on the upstream side of the compressor 20 on the refrigerant circulation circuit 400. As a result, the first bypass 401 and the second bypass 402 are collectively connected in parallel in the refrigerant circulation circuit 400.

Further, in the second embodiment, as shown in FIGS. 6A and 6B, the heat exchanger 22 is further installed in the refrigerant circulation circuit 400. The heat exchanger 22 is installed between the first confluence point 40 and the second expansion valve 26, and is installed between the second confluence point 41 and the third expansion valve 28. At this time, the heat exchanger 22 provides heat exchange between the first refrigerant and the second refrigerant. The first refrigerant is a part of the high temperature and high pressure refrigerant. The second refrigerant is a part of the low temperature low pressure refrigerant. The heat exchanger 22 is also called an internal heat exchanger. The first refrigerant is a part of all the high-temperature and high-pressure refrigerants flowing out from the capacitor 21. That is, it is a refrigerant portion that flows out from the capacitor 21, passes through the first confluence 40, and flows into the second bypass 402. The second refrigerant is a low-temperature low-pressure refrigerant flowing out of the second bypass 402. That is, it is a part of all the refrigerant flowing toward the compressor 20. The heat exchanger 22 causes the refrigerant flowing into the second expansion valve 26 to dissipate heat, lower the temperature, and supercool. The heat exchanger 22 absorbs the amount of heat in the refrigerant flowing out from the third expansion valve 28 to make it a low-temperature low-pressure gas. As a result, the heat exchanger 22 can contribute to improving the performance of the entire system. Such an installation method is useful for integrated integration of the heat exchanger 22 and the flow path on the battery 29 side, such as designing the heat exchanger 22 and the battery heat exchanger 27 as an integrated heat exchanger.

Further, as shown in FIGS. 6A and 6B, a gas-liquid separator 36 can be further installed between the second confluence point 41 and the inlet of the compressor 20. The role of the gas-liquid separator 36 is to prevent damage to the compressor 20 by separating the gas and the liquid, as described above.

In the second embodiment, the above four types of different circulation states can be provided in the same manner. Also in this embodiment, the first mode, the second mode, the third mode, and the fourth mode can be realized. Hereinafter, the above four types of operation modes will be described in detail with reference to FIGS. 2 to 5. Of these, the first mode and the second mode are the same as those in the first embodiment, so they will not be described repeatedly here, and only the third mode and the fourth mode will be briefly described. For the first mode and the second mode, the description of the preceding embodiment can be referred to.

Air-conditioning independent cooling circulation FIG. 7 is a diagram showing a state in a third mode by the vehicle heat management system of the second embodiment. (A) is a structural schematic diagram in the third mode of the vehicle heat management system. (B) is a pressure enthalpy diagram in the third mode.

As shown in FIGS. 7A and 7B, in the third mode, the control system 500 turns on the fan 32, activates the capacitor 21, closes the second expansion valve 26, and closes the switching valve 23. It is open. The high-temperature and high-pressure refrigerant compressed by the compressor 20 passes through the capacitor 21 and dissipates heat to the outside. Since the second expansion valve 26 is closed and the switching valve 23 is open, the refrigerant after heat dissipation enters the first bypass 401. In the first bypass 401, the refrigerant enters the expansion valve 24 via the switching valve 23 to throttle the refrigerant, and the throttle is reduced in pressure to become a refrigerant in a gas-liquid mixed state lower than the vehicle interior temperature. The refrigerant enters the evaporator 25 and absorbs heat, and the refrigerant after the heat absorption enters the compressor 20 to complete the circulation in the third mode.

Both air conditioning and battery cooling circulation state FIG. 8 is a diagram showing a fourth mode by the vehicle heat management system of the second embodiment. (A) is a structural schematic diagram in the fourth mode of the vehicle heat management system. (B) It is a pressure enthalpy diagram in the 4th mode.

As shown in FIGS. 8A and 8B, in the fourth mode, the control system 500 turns on the fan 32 to activate the capacitor 21 and opens the switching valve 23 and the second expansion valve 26. .. The high-temperature and high-pressure refrigerant compressed and discharged by the compressor 20 dissipates heat through the capacitor 21. The high-temperature and high-pressure liquid refrigerant discharged from the heat exchanger 21 is divided into two at the first confluence point 40. One of the divided refrigerants enters the first bypass 401, passes through the evaporator 25, and cools the inside of the vehicle. The other of the diverted refrigerant passes from the second expansion valve 26 to the battery 29 side to cool the battery 29.

The refrigerant that has entered the first bypass 401 and has flowed out through the switching valve 23 enters the first expansion valve 24, is throttled and depressurized, and becomes a low-temperature low-pressure gas-liquid mixed state refrigerant after the temperature is lowered. This refrigerant enters the evaporator 25. The refrigerant absorbs the amount of heat of air in the evaporator 25, becomes a low-temperature low-pressure gas, and flows toward the compressor 20.

The refrigerant passing through the second bypass 402 first dissipates heat in the heat exchanger 22. In the desired state, in the heat exchanger 22, the refrigerant acquires supercooling. In the heat exchanger 22, the low-temperature low-pressure refrigerant decompressed by the third expansion valve 28 contributes to lowering the temperature of the high-temperature high-pressure refrigerant from the capacitor 21. Next, the refrigerant flows into the second expansion valve 26. The refrigerant is supplied to the second expansion valve 26 for the first throttle. The second expansion valve 26 supplies a medium-temperature, medium-pressure, gas-liquid mixed saturated refrigerant. This medium pressure is an intermediate pressure value between the high pressure in the capacitor 21 and the low pressure in the evaporator 25. The refrigerant under the intermediate pressure absorbs the amount of heat of the battery 29. The pressure value of the refrigerant can be adjusted by controlling the opening degree of the second expansion valve 26 at the battery inlet. The refrigerant discharged from the heat exchanger 27 subsequently enters the third expansion valve 28 and is used for the second throttle. The refrigerant after throttle in the third expansion valve 28 enters the heat exchanger 22 and absorbs heat for the second time. The refrigerant after endothermic merges with the refrigerant of the first bypass 401 at the second merging point 41, and the merging refrigerant returns to the compressor 20. Since the saturation temperature of the refrigerant under the intermediate pressure is higher than the saturation temperature of the refrigerant under the low pressure, the temperature difference between the refrigerant under the intermediate pressure and the battery 29 is relatively reduced. Therefore, the amount of heat of the battery 29 absorbed by the refrigerant under the intermediate pressure is relatively small. Therefore, since the pre-evaporation of the refrigerant can be suppressed and the refrigerant can always absorb heat under the gas-liquid saturation state, the surface temperature of the battery 29 is relatively uniform and the temperature difference is small. By controlling the opening degree of the second expansion valve 26 to adjust the pressure value of the refrigerant and controlling the opening degree of the third expansion valve 28 on the outlet side of the battery 29, the refrigerant is always saturated in the endothermic process. You can be assured that. The second expansion valve 26 and the third expansion valve 28 may be controlled by a mechanical temperature-sensitive control system. The second expansion valve 26 and the third expansion valve 28 may be controlled by the control system 500. Thereby, the temperature difference of the battery 29 is guaranteed to be within the required range, and the uniform temperature cooling of the battery 29 is realized.

Third Embodiment The vehicle heat management system of the third embodiment has substantially the same structure as the vehicle heat management system of the first embodiment. Therefore, only the differences will be described. FIG. 9 is a schematic structural diagram of a vehicle heat management system based on the third embodiment of the disclosure. As shown in FIG. 9, the first expansion device 34 is provided by the first expansion valve 33. The first expansion device 34 can be provided by an integrated electronic expansion valve (EXV) having a shut-off switching function. Alternatively, the first expansion device 34 can be provided by a mechanical expansion valve (Shut-off TXV) having a shut-off function. Therefore, the switching function and the throttle function can be compatible with each other only by using the first expansion valve 33. Similarly, in the third embodiment, the above-mentioned four different circulation modes can be executed, but they will not be described repeatedly here. When the first expansion valve 33 is an electronic expansion valve, the opening degree of the electronic expansion valve can be determined by the magnitude of the degree of supercooling on the rear surface of the capacitor 21. For example, the control system 500 can set a target supercooling degree SCO and can control the opening degree of the first expansion valve 33 according to the comparison result with the observed supercooling degree. The control system 500 reduces the opening degree of the electronic expansion valve when the degree of supercooling of the rear surface of the condenser 21 exceeds SCO, and increases the opening degree of the electronic expansion valve when the degree of supercooling of the rear surface of the condenser 21 is lower than SCO. ..

Other Embodiments As described above, the situation of the air conditioning circuit installed in parallel in the refrigerant circulation circuit and used for cooling the inside of the vehicle has been described. This disclosure is not limited to this, and it is also possible to realize soaking heating and soaking cooling of the battery by using only the refrigerant circulation circuit without installing the air conditioning circuit.

In the specific embodiments described above, the purpose, technical method and beneficial effects of this disclosure will be described in more detail. The above is only one of the specific embodiments of this disclosure and does not limit the scope of protection of this disclosure. This disclosure can be embodied in various forms, with the intent that it does not deviate from the basic characteristics of this disclosure. It should be understood that the embodiments in this disclosure are used for illustration and not limitation. Also, the scope of this disclosure is limited by the claims, not the specification, and is included in the claims, and all changes within the scope equivalent to the claims. It must be understood that both are included in the claims. All modifications, equivalent replacements, improvements, etc. made within the gist and principles of this disclosure shall be within the scope of this disclosure.

Claims

In the vehicle heat management system
It has a refrigerant circulation circuit, and the refrigerant circulation circuit is parallel to a compressor, a first heat exchanger in which a fan is installed, and an upstream side of the compressor and a downstream side of the first heat exchanger. Including the connected first bypass and second bypass,
The first bypass includes a first inflator and a second heat exchanger connected in sequence.
The second bypass includes a second inflator connected in sequence, a third heat exchanger and a third inflator for heat exchange with the battery.
A fourth heat exchanger is further installed on the refrigerant circulation circuit, and the fourth heat exchanger exchanges heat between the refrigerant flowing out of the first heat exchanger and the refrigerant flowing toward the compressor. Alternatively, heat exchange is performed between a part of the refrigerant flowing out from the first heat exchanger and a part of the refrigerant flowing toward the compressor.
By controlling the opening degree of the second expansion device and the third expansion device, the refrigerant flowing into the third heat exchanger is saturated, thereby adjusting the temperature of the refrigerant flowing into the third heat exchanger. A vehicle heat management system characterized by
The first bypass and the second bypass are connected in parallel between the first confluence point located on the downstream side of the first heat exchanger and the second confluence point located on the upstream side of the compressor.
The fourth heat exchanger is located between the first heat exchanger and the first confluence, and between the second confluence and the compressor, and is the first heat exchanger. The vehicle heat according to claim 1, wherein the heat is used to exchange heat between the refrigerant flowing from the first confluence toward the first confluence and the refrigerant flowing from the second confluence toward the compressor. Management system.
The first bypass and the second bypass are connected in parallel between the first confluence point located on the downstream side of the first heat exchanger and the second confluence point located on the upstream side of the compressor.
The fourth heat exchanger is located between the first confluence point and the second expansion device, and between the third expansion device and the second confluence point, and the first confluence point. The vehicle heat management according to claim 1, wherein the refrigerant is used to exchange heat between the refrigerant flowing into the second expansion device and the refrigerant from the third expansion device toward the second confluence. system.
The first expansion device is configured independently by an electronic expansion valve or a mechanical expansion valve having a shut-off function, or on the mechanical temperature expansion valve and the first bypass on the upstream side of the mechanical temperature expansion valve. The vehicle heat management system according to any one of claims 1 to 3, wherein the vehicle is composed of an attached solenoid valve.
The second expansion device is configured independently by an electronic expansion valve or a mechanical expansion valve having a shut-off function, or on the mechanical temperature expansion valve and the second bypass on the upstream side of the mechanical temperature expansion valve. The vehicle heat management system according to any one of claims 1 to 3, wherein the vehicle is composed of an attached solenoid valve.
The vehicle heat management system according to any one of claims 1 to 3, wherein a gas-liquid separator is installed on the inlet side of the compressor.
The vehicle heat management system executes a first mode when cooling the battery independently.
The feature is that the second mode is executed when the battery is heated, the third mode is executed when only the inside of the vehicle is cooled, and the fourth mode is executed when the inside of the vehicle and the battery are cooled at the same time. The vehicle heat management system according to any one of claims 1 to 3.
When performing the first mode, the fan on the first heat exchanger is turned on, the first expansion device is closed, and the first mode is based on the degree of superheat of the refrigerant on the outlet side of the third heat exchanger. 2. The vehicle heat management system according to claim 7, wherein the opening degree of the expansion device is controlled to keep the third expansion device fully open.
When the second mode is performed, the fan on the first heat exchanger is turned off, the first expansion device is closed, the second expansion device is opened, and before entering the second expansion device. The opening degree of the second expansion device is controlled based on the degree of superheat of the refrigerant, the opening degree of the third expansion device is controlled based on the degree of superheat on the inlet side of the compressor, and the third heat exchanger is controlled. The vehicle heat management system according to claim 7, wherein the rotation speed of the compressor is controlled based on the amount of heat exchange required for the compressor.
The vehicle according to claim 7, wherein when the third mode is performed, the fan on the first heat exchanger is turned on, the first expansion device is opened, and the second expansion device is closed. Thermal management system.
When the fourth mode is performed, the fan on the first heat exchanger is turned on, the first expansion device is opened, the second expansion device is opened, and the refrigerant is transmitted to the third heat exchanger. It is characterized in that the opening degree of the second expansion device is controlled based on the amount of heat generated, and the opening degree of the third expansion device is controlled based on the degree of overheating of the refrigerant on the outlet side of the third heat exchanger. The vehicle heat management system according to claim 7.