Whole vehicle liquid-cooled battery pack heating and cooling system and method

Abstract

The invention provides a whole vehicle liquid cooling battery pack heating and cooling system and method. The system comprises an upper computer, an expansion kettle, a temperature sensor, a first three-way valve, a water pump, a heating unit, a refrigeration unit and a second three-way valve, a first interface of the first three-way valve is connected with a water outlet of the water pump, a second interface is connected with a water outlet of the vehicle battery pack heat management circulating waterway, and a third interface is connected with a water inlet of the battery pack; a first interface of the second three-way valve is connected with a water inlet of the refrigeration unit, a second interface of the second three-way valve is connected with a water inlet of the vehicle battery pack heat management circulating water path, and a third interface of the second three-way valve is connected with a water outlet of the battery pack; the two three-way valves, the temperature sensor, the heating unit and the refrigerating unit are electrically connected with the control unit, and the upper computer is electrically connected with the control unit and the vehicle-mounted self-diagnosis system. Rapid heating and cooling of the battery pack can be realized, the vehicle immersion time is shortened, and the cost is saved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular relates to a temperature rise and fall system and method for a liquid-cooled battery pack of a whole vehicle. Background Art

[0002] With the rapid development of new energy vehicles, all vehicle manufacturers have increased their research and development efforts in hybrid and pure electric vehicles, resulting in more and more vehicle testing tasks. In addition, when conducting environmental tests on new energy vehicles, most vehicles need to be immersed in order to make the temperature of the vehicle battery pack consistent with the ambient temperature. Since the battery pack has good sealing, it takes a long time to heat and cool the battery pack. Off-season tests, such as cooling in summer and heating in winter, often require longer immersion time. This is even more stretched for the already tight environmental chamber resources, which will delay the progress of other test tasks.

[0003] At present, when testing hybrid and pure electric vehicles, the temperature rise and fall of the battery pack is to place the vehicle in an environmental chamber. When the ambient temperature reaches the required temperature, the high and low temperature environment is used to naturally change the temperature of the battery pack to the required temperature. However, the natural temperature rise and fall of the battery pack takes a long time, and the vehicle even needs to be immersed for more than 20 hours in extreme environmental tests. With the continuous improvement of battery pack production technology, its sealing and thermal insulation properties are getting better and better, which makes the temperature rise and fall of the battery pack more difficult. The main disadvantages of heating and cooling the battery pack in the environmental chamber are: the long immersion time of the vehicle is accompanied by the increase of personnel, energy, material and other costs, and at the same time, the use time of the environmental chamber becomes longer, which increases wear and tear; because the vehicle is immersed for a long time, it occupies more environmental chamber resources, causing delays to other R&D test tasks. Therefore, how to design a whole vehicle liquid-cooled battery pack temperature rise and fall system and method to achieve rapid temperature rise and fall of the battery pack and effectively shorten the vehicle immersion time has become a technical problem that technicians in this field urgently need to solve. Summary of the invention

[0004] The object of the present invention is to provide a vehicle liquid-cooled battery pack temperature rise and fall system to solve the above technical problems in the prior art. Another object of the present invention is to provide a vehicle liquid-cooled battery pack temperature rise and fall method.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A whole vehicle liquid-cooled battery pack temperature rise and fall system, comprising a control unit, a heating unit, a refrigeration unit, a host computer, a first three-way valve, a second three-way valve, a water pump, an expansion kettle, and a temperature sensor. The first three-way valve, the water pump, the heating unit, the refrigeration unit, and the second three-way valve are sequentially arranged in series on a temperature rise and fall water path. The temperature sensor is arranged between the second three-way valve and the refrigeration unit. The expansion kettle is connected between the water pump and the heating unit through a pipeline. The first interface of the first three-way valve is connected to the water outlet of the water pump, and the second interface of the first three-way valve is connected to the vehicle battery. The first three-way valve is connected to the water outlet of the thermal management circulating water circuit of the battery pack, and the third interface of the first three-way valve is connected to the water inlet of the battery pack; the first interface of the second three-way valve is connected to the water inlet of the refrigeration unit, the second interface of the second three-way valve is connected to the water inlet of the thermal management circulating water circuit of the vehicle battery pack, and the third interface of the second three-way valve is connected to the water outlet of the battery pack; the first three-way valve, the second three-way valve, the temperature sensor, the heating unit and the refrigeration unit are electrically connected to the control unit respectively, the control unit is electrically connected to the host computer, and the host computer is electrically connected to the vehicle-mounted self-diagnosis system.

[0007] A method for increasing and decreasing the temperature of a liquid-cooled battery pack of a vehicle comprises the following steps:

[0008] Step S1, before the vehicle is immersed, the control unit controls the communication state of the first three-way valve so that the first interface of the first three-way valve is connected to the third interface and the second interface is cut off; at the same time, the control unit controls the communication state of the second three-way valve so that the first interface of the second three-way valve is connected to the third interface and the second interface is cut off;

[0009] Step S2, input the test required temperature of the battery pack on the host computer, and then the host computer transmits the test required temperature to the control unit; the control unit compares the actual temperature of the battery pack with the test required temperature, and if the actual temperature of the battery pack is equal to the test required temperature, proceed to step S5; if the actual temperature of the battery pack is not equal to the test required temperature, proceed to step S3;

[0010] Step S3, the control unit compares the temperature of the coolant in the heating and cooling water path detected by the temperature sensor with the test required temperature of the battery pack. If the temperature of the coolant is equal to the test required temperature of the battery pack, the process proceeds to step S4; if the temperature of the coolant is not equal to the test required temperature of the battery pack, the temperature of the coolant is adjusted until the temperature of the coolant is equal to the test required temperature of the battery pack, and then the process proceeds to step S4;

[0011] Step S4, the control unit compares the actual temperature of the battery pack with the test required temperature. If the actual temperature of the battery pack is equal to the test required temperature, the process proceeds to step S5; if the actual temperature of the battery pack is not equal to the required temperature, the process returns to step S3;

[0012] Step S5, the control unit controls the second interface of the first three-way valve to be connected to the third interface, and the first interface thereof is cut off; at the same time, the control unit controls the second interface of the second three-way valve to be connected to the third interface, and the first interface thereof is cut off.

[0013] Preferably, in step S3, the specific method for adjusting the temperature of the coolant includes: if the temperature of the coolant is greater than the test required temperature of the battery pack, the control unit controls the refrigeration unit to operate to cool the coolant until the temperature of the coolant is equal to the test required temperature of the battery pack, and then enters step S4.

[0014] Preferably, the cooling of the cooling liquid is achieved by heat exchange between the refrigeration unit and the cooling liquid.

[0015] Preferably, in step S3, the specific method for adjusting the temperature of the coolant also includes: if the temperature of the coolant is lower than the test required temperature of the battery pack, the control unit controls the heating unit to operate to heat the coolant until the temperature of the coolant is equal to the test required temperature of the battery pack, and then enters step S4.

[0016] Preferably, the heating unit and the coolant are heated by heat exchange.

[0017] Preferably, the host computer collects the actual temperature of the battery pack through the on-board self-diagnosis system and then transmits it to the control unit.

[0018] Preferably, when the actual temperature of the battery pack collected by the host computer exceeds the maximum temperature designed for the battery pack, the host computer triggers the alarm device to sound and light alarm.

[0019] The beneficial effects of the present invention are:

[0020] The whole vehicle liquid-cooled battery pack temperature control system and method of the present invention can control the heating unit and the refrigeration unit through the control unit according to actual needs, so that the battery pack can be heated and cooled more quickly. Compared with the prior art, the vehicle immersion time is effectively shortened, the cost is saved, the environmental chamber resources are saved, and the progress of other test tasks is better guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present invention in detail in conjunction with the drawings, wherein

[0022] Figure 1 A schematic diagram of a vehicle liquid-cooled battery pack temperature rise and fall system provided by an embodiment of the present invention;

[0023] Figure 2 A flow chart of a method for increasing and decreasing the temperature of a liquid-cooled battery pack of a vehicle provided in an embodiment of the present invention.

[0024] Markings in the accompanying drawings:

[0025] 1. Thermal management water circuit of vehicle battery pack, 2. Battery pack, 3. First three-way valve,

[0026] 4. Water pump, 5. Expansion kettle, 6. Heating unit, 7. Signal connection line,

[0027] 8. Control unit, 9. Host computer, 10. Refrigeration unit, 11. Heating and cooling water circuit,

[0028] 12. Temperature sensor, 13. Second three-way valve, 14. On-board self-diagnosis system. DETAILED DESCRIPTION

[0029] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0030] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0031] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0032] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0033] like Figure 1As shown, an embodiment of the present invention provides a vehicle liquid-cooled battery pack temperature rise and fall system, which includes a control unit 8, a heating unit 6, a refrigeration unit 10, a host computer 9, a first three-way valve 3, a second three-way valve 13, a water pump 4, an expansion kettle 5, and a temperature sensor 12. The first three-way valve 3, the water pump 4, the heating unit 6, the refrigeration unit 10, and the second three-way valve 13 are sequentially arranged in series on a temperature rise and fall water path 11, the temperature sensor 12 is arranged between the second three-way valve 13 and the refrigeration unit 10, and the expansion kettle 5 is connected between the water pump 4 and the heating unit 6 through a pipeline; the first interface of the first three-way valve is connected to the water outlet of the water pump The second interface of the first three-way valve 3 is connected to the water outlet of the thermal management circulating water circuit 1 of the vehicle battery pack, and the third interface of the first three-way valve is connected to the water inlet of the battery pack 2; the first interface of the second three-way valve 13 is connected to the water inlet of the refrigeration unit, the second interface of the second three-way valve is connected to the water inlet of the thermal management circulating water circuit of the vehicle battery pack, and the third interface of the second three-way valve is connected to the water outlet of the battery pack; the first three-way valve, the second three-way valve, the temperature sensor, the heating unit and the refrigeration unit are electrically connected to the control unit respectively, the control unit is electrically connected to the host computer 9, and the host computer is electrically connected to the on-board self-diagnosis system.

[0034] The whole vehicle liquid-cooled battery pack temperature control system provided in the embodiment of the present invention can control the heating unit 6 and the refrigeration unit 10 through the control unit 8 according to actual needs, so that the battery pack can be heated and cooled more quickly. Compared with the prior art, the vehicle immersion time is effectively shortened, the cost is saved, the environmental chamber resources are saved, and the progress of other test tasks is better guaranteed.

[0035] like Figure 2 As shown, the embodiment of the present invention also provides a battery pack heating and cooling method based on the above vehicle liquid-cooled battery pack heating and cooling system, which includes the following steps:

[0036] Step S1, before the vehicle is immersed, the control unit controls the connection state of the first three-way valve 3, so that the first interface of the first three-way valve is connected to the third interface, and the second interface thereof is cut off; at the same time, the control unit controls the connection state of the second three-way valve 13, so that the first interface of the second three-way valve 13 is connected to the third interface, and the second interface thereof is cut off, so that the battery pack 2 is separated from the battery pack thermal management circulation water circuit 1 of the vehicle itself and connected to the heating and cooling water circuit 11; at this time, the heating and cooling water circuit is replenished with water and exhausted through the expansion kettle 5, and the control unit 8 controls the water pump 4 to start working;

[0037] Step S2, input the test required temperature of the battery pack on the host computer 9, and then the host computer transmits the test required temperature to the control unit; the control unit compares the actual temperature of the battery pack with the test required temperature, and if the actual temperature of the battery pack is equal to the test required temperature, proceed to step S5; if the actual temperature of the battery pack is not equal to the test required temperature, proceed to step S3;

[0038] Step S3, the control unit 8 compares the temperature of the coolant in the heating and cooling water path detected by the temperature sensor 12 with the test required temperature of the battery pack. If the temperature of the coolant is equal to the test required temperature of the battery pack, the process proceeds to step S4; if the temperature of the coolant is not equal to the test required temperature of the battery pack, the temperature of the coolant is adjusted until the temperature of the coolant is equal to the test required temperature of the battery pack, and then the process proceeds to step S4;

[0039] Step S4, the control unit 8 compares the actual temperature of the battery pack with the test required temperature. If the actual temperature of the battery pack is equal to the test required temperature, the process proceeds to step S5; if the actual temperature of the battery pack is not equal to the required temperature, the process returns to step S3;

[0040] Step S5: The control unit 8 controls the second interface of the first three-way valve to be connected to the third interface, and the first interface is cut off; at the same time, the control unit controls the second interface of the second three-way valve to be connected to the third interface, and the first interface is cut off, so that the battery pack is connected to the battery pack thermal management circulation water circuit of the vehicle itself. At this time, the control unit controls the water pump to stop working, and the host computer can display "work completed" to prompt the test personnel.

[0041] Furthermore, in step S3, the specific method for adjusting the temperature of the coolant includes: if the temperature of the coolant is greater than the test required temperature of the battery pack, the control unit 8 controls the refrigeration unit to operate to cool the coolant until the temperature of the coolant is equal to the test required temperature of the battery pack, and then enters step S4.

[0042] Specifically, the cooling of the cooling liquid is achieved by heat exchange between the refrigeration unit and the cooling liquid. In a specific embodiment, the refrigeration unit may have the ability to reduce the temperature of the cooling liquid to -40°C.

[0043] Furthermore, in step S3, the specific method for adjusting the temperature of the coolant also includes: if the temperature of the coolant is lower than the test required temperature of the battery pack, the control unit controls the heating unit to operate to heat the coolant until the temperature of the coolant is equal to the test required temperature of the battery pack, and then enters step S4.

[0044] Specifically, the heating unit and the coolant are heated by heat exchange. In a specific embodiment, the heating unit can increase the temperature of the coolant to 60°C.

[0045] Preferably, the host computer 9 collects the actual temperature of the battery pack through the vehicle self-diagnosis system 14 (OBD for short), and then transmits it to the control unit. It is understandable that the host computer 9 can be directly connected to the OBD interface of the vehicle through a signal connection line, so as to conveniently realize the electrical connection between the host computer and the vehicle self-diagnosis system; Figure 1 The dotted line in represents the signal connection line 7.

[0046] Specifically, when the actual temperature of the battery pack collected by the host computer 9 exceeds the maximum temperature designed for the battery pack, the host computer triggers the alarm device to sound and light alarm. The actual temperature of the battery pack and the working information of the temperature control system can be displayed on the display interface of the host computer. It can also display system control, collection and other information. When the system fails, sound and light alarms are issued. The actual temperature of the battery pack collected can also be compared with the maximum temperature designed for the battery pack. For example, if the maximum temperature designed for the battery pack is 40°C, if the actual temperature of the battery pack collected is greater than 40°C, sound and light alarms are issued to prompt the test personnel.

[0047] Preferably, the control accuracy of the present invention is ±0.5°C. For example, when judging whether the actual temperature of the battery pack is equal to the test required temperature, as long as the difference between the actual temperature of the battery pack and the test required temperature is within ±0.5°C, it can be determined that the actual temperature of the battery pack is equal to the test required temperature. Otherwise, the two temperatures are not equal. The above method can also be used to judge whether the temperature of the coolant is equal to the test required temperature of the battery pack, which will not be repeated here. The water pump is electrically connected to the control unit. After the control unit controls the water pump to be powered on, the water pump starts working. It can run at low power. Since the flow rate in the heating and cooling water circuit is small at this time, it can exchange heat with the battery pack as fully as possible, shortening the working time. Of course, the control unit can also flexibly adjust the power of the water pump according to actual needs to achieve rapid heating and cooling of the battery pack.

[0048] The whole vehicle liquid-cooled battery pack temperature rise and fall system and battery pack temperature rise and fall control method of the present invention are systems independent of the whole vehicle thermal management system. It mainly uses external heat sources and cold sources such as heating units and refrigeration units to actively make the actual temperature of the battery pack quickly reach the test requirement temperature, so as to reduce the vehicle immersion time and save test resources and energy. Since the battery pack needs to reach a certain temperature when conducting environmental tests, the immersion method currently used is to place the vehicle in an environmental chamber and heat the battery pack by air cooling. This method has the problem of taking a long time and wasting energy, and the vehicle is in the OFF state during the immersion stage, and the water pump, compressor, heat exchanger and other components in its own circulating water circuit cannot work, resulting in slow heat exchange between the battery pack and the outside world. The battery pack temperature rise and fall system and method of the present invention can effectively solve the above problems, achieve the purpose of rapid and accurate temperature rise and fall of the battery pack, shorten the working time of the environmental chamber, and extend its service life. It is simple to operate, efficient and safe. The present invention is mainly used for the rapid temperature rise and fall of the whole vehicle liquid-cooled battery pack, and can also be used for the rapid temperature rise and fall of other liquid-cooled components.

[0049] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A vehicle liquid-cooled battery pack temperature rise and fall system, characterized in that: It includes a control unit, a heating unit, a refrigeration unit, a host computer, a first three-way valve, a second three-way valve, a water pump, an expansion kettle, and a temperature sensor. The first three-way valve, the water pump, the heating unit, the refrigeration unit, and the second three-way valve are sequentially arranged in series on a heating and cooling water path. The temperature sensor is arranged between the second three-way valve and the refrigeration unit. The expansion kettle is connected between the water pump and the heating unit through a pipeline. The first interface of the first three-way valve is connected to the water outlet of the water pump, and the second interface of the first three-way valve is connected to the thermal management circulating water outlet of the vehicle battery pack. The first three-way valve and the second three-way valve are connected to the water outlet of the thermal management circulation water circuit of the vehicle battery pack, and the third interface of the first three-way valve is connected to the water inlet of the battery pack; the first interface of the second three-way valve is connected to the water inlet of the refrigeration unit, the second interface of the second three-way valve is connected to the water inlet of the thermal management circulation water circuit of the vehicle battery pack, and the third interface of the second three-way valve is connected to the water outlet of the battery pack; the first three-way valve, the second three-way valve, the temperature sensor, the heating unit and the refrigeration unit are electrically connected to the control unit respectively, the control unit is electrically connected to the host computer, and the host computer is electrically connected to the vehicle self-diagnosis system.

2. A method for increasing and decreasing the temperature of a liquid-cooled battery pack of a vehicle, characterized in that: It includes the following steps: Step S1, before the vehicle is immersed, the control unit controls the communication state of the first three-way valve so that the first interface of the first three-way valve is connected to the third interface and the second interface is cut off; at the same time, the control unit controls the communication state of the second three-way valve so that the first interface of the second three-way valve is connected to the third interface and the second interface is cut off; Step S2, input the test required temperature of the battery pack on the host computer, and then the host computer transmits the test required temperature to the control unit; the control unit compares the actual temperature of the battery pack with the test required temperature, and if the actual temperature of the battery pack is equal to the test required temperature, proceed to step S5; if the actual temperature of the battery pack is not equal to the test required temperature, proceed to step S3; Step S3, the control unit compares the temperature of the coolant in the heating and cooling water path detected by the temperature sensor with the test required temperature of the battery pack. If the temperature of the coolant is equal to the test required temperature of the battery pack, the process proceeds to step S4; if the temperature of the coolant is not equal to the test required temperature of the battery pack, the temperature of the coolant is adjusted until the temperature of the coolant is equal to the test required temperature of the battery pack, and then the process proceeds to step S4; Step S4, the control unit compares the actual temperature of the battery pack with the test required temperature. If the actual temperature of the battery pack is equal to the test required temperature, the process proceeds to step S5; if the actual temperature of the battery pack is not equal to the required temperature, the process returns to step S3; Step S5, the control unit controls the second interface of the first three-way valve to be connected to the third interface, and the first interface thereof is cut off; at the same time, the control unit controls the second interface of the second three-way valve to be connected to the third interface, and the first interface thereof is cut off.

3. The method for cooling and lowering the temperature of a liquid-cooled battery pack of a vehicle according to claim 2, characterized in that: In step S3, the specific method for adjusting the temperature of the coolant includes: if the temperature of the coolant is greater than the test required temperature of the battery pack, the control unit controls the refrigeration unit to operate and cool the coolant until the temperature of the coolant is equal to the test required temperature of the battery pack, and then enters step S4.

4. The method for cooling and lowering the temperature of a liquid-cooled battery pack of a vehicle according to claim 3, characterized in that: The cooling of the coolant is achieved by heat exchange between the refrigeration unit and the coolant.

5. The method for cooling and lowering the temperature of a liquid-cooled battery pack of a vehicle according to claim 3, characterized in that: In step S3, the specific method for adjusting the temperature of the coolant also includes: if the temperature of the coolant is lower than the test required temperature of the battery pack, the control unit controls the heating unit to operate to heat the coolant until the temperature of the coolant is equal to the test required temperature of the battery pack, and then enters step S4.

6. The method for heating and cooling a liquid-cooled battery pack of a vehicle according to claim 5, characterized in that: The heating unit and the coolant are heated by heat exchange.

7. The method for heating and cooling a liquid-cooled battery pack of a vehicle according to claim 2, characterized in that: The host computer collects the actual temperature of the battery pack through the on-board self-diagnosis system and then transmits it to the control unit.

8. The method for cooling and lowering the temperature of a liquid-cooled battery pack of a vehicle according to claim 2, characterized in that: When the actual temperature of the battery pack collected by the host computer exceeds the maximum temperature designed for the battery pack, the host computer triggers the alarm device to sound and light alarm.

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