A thermal management system and a new energy vehicle

Abstract

The application belongs to the technical field of thermal management, and particularly relates to a thermal management system and a new energy vehicle. The thermal management system comprises a refrigerant circuit, a main cooling circuit, a battery cooling circuit, a first heat exchanger and a second heat exchanger. A condenser, a compressor and an expansion valve are arranged in series on the refrigerant circuit. The refrigerant circuit exchanges heat with the main cooling circuit through the first heat exchanger, so as to cool the main cooling circuit. The main cooling circuit exchanges heat with the battery cooling circuit through the second heat exchanger, so as to cool the battery cooling circuit. The battery cooling circuit is used for cooling the battery system. An interface for connecting a cab cooling device is arranged on the main cooling circuit, and the cab cooling device is used for cooling the cab. Thus, the application solves the problem that the refrigeration effect of the air conditioning system and the battery system cannot be considered simultaneously in the prior art.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thermal management, and particularly relates to a thermal management system and a new energy vehicle. BACKGROUND

[0002] The future of new energy vehicle thermal management is promising, with a domestic market exceeding 40 billion yuan in 2025, and battery thermal management reaching 20 billion yuan. According to the single vehicle price of domestic air conditioning and battery thermal management and the future penetration rate, NE predicts that the domestic new energy vehicle sales will reach 5 million vehicles in 2025 according to the positive factors, and the corresponding vehicle thermal management market space will be 405 billion; the battery thermal management market will be 204 billion. That is, in the future, the battery thermal management of new energy vehicles will reach the same whole vehicle thermal management share as traditional vehicle air conditioning.

[0003] With the increasing demand for battery thermal management and the increasing requirement for air conditioning comfort, in the case of using a water cooling system in the battery system and the air conditioning system, the antifreeze water temperature required by the battery refrigeration is generally 10-25℃, and the antifreeze water temperature required by the air conditioning system is generally 0-10℃. The water temperature intervals of the two are inconsistent. If the same antifreeze system is used, when the antifreeze water temperature interval is 10-25℃, the refrigeration capacity of the air conditioning system cannot be guaranteed, and when the antifreeze water temperature interval is 0-10℃, the battery temperature may be too low, causing battery condensation and other problems. The existing air conditioning + battery thermal management integrated system that can consider both water temperature intervals is not ideal.

[0004] At present, integrated battery thermal management mainly uses air conditioning system refrigerant direct cooling method + battery water cooling method or air conditioning system + battery system double water cooling method. The first method has poor air conditioning comfort, and the water in the cab is taken away during the refrigeration process, causing dry air in the cab. The second method cannot guarantee the refrigeration temperature interval and the refrigeration effect of the air conditioning system and the battery system because the antifreeze water temperature required by the battery system and the air conditioning system is inconsistent. When the air conditioning system and the battery thermal management are turned on at the same time, it is easy to cause poor air conditioning refrigeration capacity or low battery temperature, causing battery condensation and other problems. In short, the existing integrated battery thermal management system has advantages and disadvantages, and cannot guarantee the refrigeration temperature interval and the refrigeration effect of the air conditioning system and the battery system at the same time. SUMMARY

[0005] The purpose of the present application is to provide a thermal management system and a new energy vehicle to solve the problem that the refrigeration effect of the air conditioning system and the battery system cannot be considered at the same time in the prior art.

[0006] To solve the above technical problems, the technical solutions provided by the present application and the beneficial effects corresponding to the technical solutions are as follows:

[0007] The heat management system of the application comprises a refrigerant circuit, a main cooling circuit, a battery cooling circuit, a first heat exchanger and a second heat exchanger; the condenser, the compressor and the expansion valve are arranged in series on the refrigerant circuit; the refrigerant circuit exchanges heat with the main cooling circuit through the first heat exchanger to cool the main cooling circuit; the main cooling circuit exchanges heat with the battery cooling circuit through the second heat exchanger to cool the battery cooling circuit; the battery cooling circuit is used to cool the battery system; and the main cooling circuit is provided with an interface for connecting the cab cooling device to cool the cab through the cab cooling device.

[0008] The heat management system has the following advantages: compared with the prior art, the heat management system can ensure the refrigeration effect of the cab and the temperature of the battery system by using two sets of heat exchangers; the main cooling circuit is cooled by the refrigerant in the refrigerant circuit through the first heat exchanger, and the battery system is cooled by the main cooling circuit through the second heat exchanger; since the main cooling circuit absorbs a certain amount of heat after cooling the cab, the temperature of the medium in the main cooling circuit rises to a certain extent, so that the battery system is prevented from being too low in temperature to cause condensation and other problems, the service life of the battery is improved, and the charging rate is improved; the lowest temperature medium obtained by the medium in the main cooling circuit of the heat management system through the refrigerant circuit is directly used to cool the cab, and the refrigeration capacity of the cab is ensured; experiments prove that the working temperature range of the medium is 10-25℃ when the battery system is cooled, which can effectively prevent the battery from being too low in temperature to cause condensation and other problems; the working temperature range of the medium is 0-10℃ when the cab is cooled, which is more comfortable than the outflow temperature of the traditional water-cooled air conditioner, and the air conditioner in the cab does not take away water during operation, which makes people feel more comfortable; in addition, the heat management system can control the operation of the second heat exchanger according to needs to ensure the lowest power consumption; and the heat management system has the characteristics of simple equipment, light weight and high comfort.

[0009] Further, the main cooling circuit is further provided with a circulating water pump.

[0010] Further, the battery cooling circuit comprises a circulating driving branch and a battery cooling branch connected in series, the circulating driving branch comprises a plurality of circulating driving sub-branches connected in parallel, a water pump is arranged on each circulating driving sub-branch, and the battery cooling branch comprises a plurality of battery cooling sub-branches connected in parallel, each battery cooling sub-branch is used to cool each battery module included in the battery system.

[0011] Further, in order to realize low power consumption and improve the cooling effect, the compressor speed is automatically adjusted according to the water temperature during the operation of the heat management system.

[0012] Further, the thermal management system further comprises a first expansion tank for supplementing liquid for the main cooling circuit.

[0013] Further, the thermal management system further comprises a second expansion tank for supplementing liquid for the battery cooling circuit.

[0014] Further, the first heat exchanger and the second heat exchanger are both plate heat exchangers.

[0015] Further, the plurality of parallelly arranged circulation driving sub-branches are two, and one water pump is arranged on each circulation driving sub-branch.

[0016] The new energy vehicle of the present application comprises a vehicle body, and further comprises a thermal management system according to the present application, so as to achieve the same effect as the thermal management system according to the present application. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of the principle of a thermal management system according to the present application. DETAILED DESCRIPTION

[0018] The present application aims to provide a thermal management system with secondary heat exchange function, as shown in the drawings, the thermal management system has a secondary heat exchange plate heat exchanger, the main circuit antifreeze exchanges heat with the refrigerant through the plate heat exchanger and then cools the air conditioning system, the auxiliary circuit antifreeze exchanges heat with the main circuit antifreeze through the plate heat exchanger and then cools the battery system, so as to improve the refrigeration capacity of the air conditioning system and ensure that the battery system does not have too low temperature to cause condensation and other problems. The above-mentioned main circuit is a main cooling circuit, and the auxiliary circuit is a battery cooling circuit. Figure 1

[0019] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below in combination with the drawings and examples.

[0020] An embodiment of a thermal management system:

[0021] An embodiment of a thermal management system according to the present application, the thermal management system comprises a first heat exchanger, a second heat exchanger, a refrigerant circuit, a main cooling circuit and a battery cooling circuit, as shown in the drawings, in this embodiment, the medium of the main cooling circuit is antifreeze; the medium of the battery cooling circuit is also antifreeze, and the heat exchanger is a plate heat exchanger. Figure 1

[0022] ​​The refrigerant circuit exchanges heat with the main cooling circuit through the first heat exchanger to cool the main cooling circuit; the main cooling circuit also exchanges heat with the battery cooling circuit through the second heat exchanger to cool the battery cooling circuit. The thermal management system is provided with a first expansion tank and a second expansion tank, the first expansion tank is used to deaerate and supplement the main cooling circuit, and the second expansion tank is used to deaerate and supplement the battery cooling circuit. An interface for connecting the cab cooling device is arranged on the main cooling circuit, the interface connects the driver fan coil, and the cab is cooled through the cab fan coil. The main cooling circuit also cools the battery system through the second heat exchanger. The battery cooling circuit is used to cool the battery system. Further, in order to speed up the cooling effect of the battery system, the battery cooling circuit includes a circulating driving branch and a battery cooling branch in series, the circulating driving branch includes a plurality of parallel circulating driving sub-branches, a water pump is arranged on each circulating driving sub-branch, and the battery cooling branch includes a plurality of parallel battery cooling sub-branches, each battery cooling sub-branch is used to cool each battery module included in the battery system. Specifically, the plurality of parallel circulating driving sub-branches are two, and one water pump is arranged on each circulating driving sub-branch, that is, two water pumps are used for cooling the battery system in the battery cooling circuit, and the two water pumps are used to collect and then distribute antifreeze to different battery modules. The condenser, compressor and expansion valve are arranged in series on the refrigerant circuit, and the expansion valve is a thermal expansion valve in this embodiment.

[0023] Specifically, the condenser in the refrigerant circuit converts high-temperature and high-pressure refrigerant into low-temperature and low-pressure refrigerant, and then the low-temperature refrigerant is transmitted to the first heat exchanger through the thermal expansion valve to exchange heat with the high-temperature antifreeze in the main cooling circuit; the high-temperature refrigerant after heat exchange is compressed and adjusted in pressure by the compressor and then returns to the condenser for cooling, and the refrigerant in the refrigerant circuit is thus circulated to cool the main cooling circuit.

[0024] The low-temperature antifreeze in the main cooling circuit is cooled and cooled by the first heat exchanger, and then flows to the cab fan coil to cool the cab, and the low-temperature antifreeze absorbs heat in the cab and becomes low-temperature antifreeze with a slightly higher temperature, and the low-temperature antifreeze with a slightly higher temperature is cooled and exchanged by the second heat exchanger to become high-temperature antifreeze, and the high-temperature antifreeze returns to the first heat exchanger to cool and exchange heat with the low-temperature refrigerant in the refrigerant circuit, and the main cooling circuit is thus circulated to cool the cab and the battery cooling circuit.

[0025] The anti-freezing solution in the battery cooling circuit is cooled in the second heat exchanger, and then the anti-freezing solution is driven into a plurality of battery cooling sub-branches by a circulating water pump on a circulating driving sub-branch to cool and lower the temperature of the battery system, and the anti-freezing solution becomes high-temperature anti-freezing solution after absorbing the heat of the battery, and the high-temperature anti-freezing solution is cooled and lowered in temperature again in the second heat exchanger, and the battery cooling circuit is circulated to cool and lower the temperature of the battery system.

[0026] In specific work, when the cab needs to be refrigerated, the first heat exchanger works, the second heat exchanger stops working, and the air conditioning system composed of the refrigerant circuit, the cab fan coil and the main cooling circuit starts to work. First, the refrigerant circuit works, exchanges heat through the first heat exchanger to cool the main cooling circuit, and then the main cooling circuit is cooled by the circulating water pump to the cab fan coil. At this time, only the cab needs to be cooled, and the refrigerant circuit can completely guarantee the working water temperature interval of 0-10℃, meeting the cooling demand of the cab. Moreover, compared with the traditional air conditioning water-cooled air conditioner, the air outlet temperature is softer, and the air conditioning water in the cab is not taken away during operation, making people feel more comfortable.

[0027] When the cab and the battery system need to be refrigerated at the same time, the first heat exchanger and the second heat exchanger work, and the air conditioning system and the battery cooling circuit need to be cooled. First, the refrigerant circuit works, exchanges heat through the first heat exchanger to cool the main cooling circuit, and then the main cooling circuit is cooled by the circulating water pump to the cab fan coil. Then, the low-temperature anti-freezing solution with a slightly higher temperature is cooled and exchanged by the second heat exchanger for the battery cooling circuit, and the anti-freezing solution is collected by the circulating water pump 2 and the circulating water pump 3 respectively arranged in the two parallel circulating driving sub-branches, and finally distributed to different battery modules through a plurality of battery cooling sub-branches to cool and lower the temperature of the battery. Among them, the low-temperature anti-freezing solution with a slightly higher temperature absorbs some heat in the cab, and the working water temperature interval is 10-25℃, which can effectively avoid problems such as condensation caused by too low temperature of the battery.

[0028] The present application has a secondary heat exchanger plate heat exchanger, the main circuit anti-freezing solution exchanges heat with the refrigerant through the plate heat exchanger to cool the air conditioning system, and the auxiliary circuit anti-freezing solution exchanges heat with the main circuit anti-freezing solution through the plate heat exchanger to cool the battery system. This can not only improve the refrigeration capacity of the air conditioning system, but also ensure that the battery system does not have problems such as condensation caused by too low temperature.

[0029] In addition, in order to guarantee the cooling effect of the heat management system and reduce the power consumption of the whole vehicle, the heat management system has an automatic frequency conversion function, which automatically adjusts the rotating speed of the compressor according to the water temperature state during operation, so as to reduce the energy consumption of the whole vehicle while guaranteeing the battery and air conditioning refrigeration. Specifically, when the battery cooling state, the battery system sends an air conditioning system battery cooling set water temperature; when the air conditioner is in operation, the air conditioning system also provides an air conditioning set water temperature. The air conditioner automatically adjusts the rotating speed of the compressor according to the two set temperatures: when the actual water temperature state deviates greatly from the set temperature or the cooling speed is slow, the rotating speed of the compressor is automatically increased to facilitate rapid reaching of the water temperature requirement, and when the water temperature difference is small or the cooling speed is fast, the rotating speed of the compressor is automatically reduced.

[0030] Compared with the prior art, the biggest advantage of the heat management system is that two sets of plate heat exchangers can guarantee the air conditioning refrigeration effect and the battery temperature at the same time. The antifreeze of the main cooling circuit exchanges heat with the refrigerant through the plate heat exchanger and then cools the air conditioning system, and the antifreeze of the battery cooling circuit exchanges heat with the antifreeze of the main cooling circuit through the plate heat exchanger and then cools the battery system. In this way, the refrigeration capacity of the air conditioning system can be improved, and the battery system can be prevented from being too low in temperature to cause condensation and other problems, so that the battery life and the charging rate can be improved. In addition, the heat management system has the characteristics of energy saving, light weight, high comfort and the like.

[0031] The present application has the following specific advantages:

[0032] 1. The present application realizes the battery cooling function, and the working water temperature interval is 10-25℃, which can effectively avoid the condensation and other problems caused by too low temperature of the battery.

[0033] 2. The present application can realize the air conditioning refrigeration function, and the working water temperature interval is 0-10℃, which is more comfortable than the traditional air conditioning water-cooled air conditioning, and the air conditioning water in the cab will not be taken away during operation, so that people feel more comfortable.

[0034] 3. The present application has an automatic frequency conversion function, which automatically adjusts the rotating speed of the compressor according to the water temperature state during operation, so as to reduce the energy consumption of the whole vehicle while guaranteeing the battery and air conditioning refrigeration.

[0035] 4. The present application has a real-time detection and reporting function of faults of each component of the air conditioning system, which is convenient for daily maintenance during vehicle operation.

[0036] 5. The present application has a secondary heat exchange plate heat exchanger. The antifreeze of the main circuit exchanges heat with the refrigerant through the plate heat exchanger and then cools the air conditioning system, and the antifreeze of the auxiliary circuit exchanges heat with the antifreeze of the main circuit through the plate heat exchanger and then cools the battery system. In this way, the refrigeration capacity of the air conditioning system can be improved, and the battery system can be prevented from being too low in temperature to cause condensation and other problems.

[0037] 6、The application has the functions of battery cooling and air conditioner refrigeration, and the highly integrated air conditioner system greatly reduces the air conditioner cost.

[0038] A new energy vehicle embodiment:

[0039] A new energy vehicle embodiment, comprising a vehicle body, a cab cooling device and a battery cooling device, further comprising a thermal management system, the thermal management system comprising a first heat exchanger, a second heat exchanger, a refrigerant circuit, a main cooling circuit and a battery cooling circuit. The thermal management system uses two sets of plate heat exchangers to simultaneously ensure the air conditioner refrigeration effect and the battery temperature. The antifreeze of the main cooling circuit exchanges heat with the plate heat exchanger and the refrigerant to cool the air conditioner system, and the antifreeze of the battery cooling circuit exchanges heat with the antifreeze of the main cooling circuit through the plate heat exchanger to cool the battery system. In this way, the refrigeration capacity of the air conditioner system can be improved, and the battery system can be prevented from being too low in temperature to cause condensation and other problems, the battery life can be better improved, and the charging rate can be improved. Specifically, a thermal management system embodiment comprises a thermal management system, which achieves the same effect as the thermal management system.

Claims

1. A thermal management system, characterized by: The heat management system comprises a refrigerant circuit, a main cooling circuit, a battery cooling circuit, a first heat exchanger and a second heat exchanger; the condenser, the compressor and the expansion valve are arranged in series on the refrigerant circuit; the refrigerant circuit exchanges heat with the main cooling circuit through the first heat exchanger to cool the main cooling circuit; the main cooling circuit exchanges heat with the battery cooling circuit through the second heat exchanger to cool the battery cooling circuit; the battery cooling circuit is used to cool the battery system; the main cooling circuit is provided with an interface for connecting a cab cooling device, which is used to cool the cab through the cab cooling device; the second heat exchanger is arranged downstream of the interface, so that the antifreeze in the main cooling circuit passes through the first heat exchanger, the cab cooling device and then the second heat exchanger in sequence.

2. The thermal management system of claim 1, wherein: The main cooling circuit is further provided with a circulating water pump.

3. The thermal management system of claim 1, wherein: The battery cooling circuit comprises a circulating driving branch and a battery cooling branch arranged in series, the circulating driving branch comprises a plurality of circulating driving sub-branches arranged in parallel, a water pump is arranged on each circulating driving sub-branch, and the battery cooling branch comprises a plurality of battery cooling sub-branches arranged in parallel, each battery cooling sub-branch is used to cool each battery module included in the battery system.

4. The thermal management system of claim 1, wherein: The compressor speed is automatically adjusted according to the water temperature during the operation of the heat management system.

5. The thermal management system of claim 1, wherein: The heat management system further comprises a first expansion water tank, which is used to supplement the main cooling circuit with liquid.

6. The thermal management system of claim 1, wherein: The heat management system further comprises a second expansion water tank, which is used to supplement the battery cooling circuit with liquid.

7. The thermal management system of any one of claims 1-6, wherein: The first heat exchanger and the second heat exchanger are both plate heat exchangers.

8. The thermal management system of claim 3, wherein: The plurality of circulating driving sub-branches arranged in parallel are two, and one water pump is arranged on each circulating driving sub-branch.

9. A new energy vehicle comprising a vehicle body, characterized in that: The heat management system according to any one of claims 1-8 is further included.

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