Battery thermal management system and battery assembly

Abstract

The invention relates to the technical field of battery thermal management, in particular to a battery thermal management system and a battery assembly. The heat management system comprises a cooling liquid circulation pipeline, a refrigerant circulation pipeline and a heat exchanger, the cooling liquid circulation pipeline flows through the outer surface of the battery module, and the cooling liquid circulation pipeline exchanges heat with the refrigerant circulation pipeline through the heat exchanger; a coaxial pipe is sleeved outside a part of the refrigerant circulating pipeline, and two ends of the coaxial pipe are connected with the cooling liquid circulating pipeline; the refrigerant circulating pipeline comprises a refrigerant driving device, and the refrigerant driving device and the heat exchanger are arranged at the two ends of part of the refrigerant circulating pipeline respectively; the cooling liquid flowing through the coaxial pipe is used for heating a refrigerant in the refrigerant circulating pipeline; by arranging the coaxial pipe, the coolant heats the refrigerant, so that the starting pressure requirement of the refrigerant driving device is reduced, the application universality of the thermal management system is improved, the service life of the battery is prolonged, and the stability of the output power of the battery is improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery thermal management, and in particular to a battery thermal management system and a battery assembly. Background Art

[0002] The battery needs to operate within a suitable temperature range to ensure the battery life and output power stability. In the prior art, a battery thermal management system is usually set to adjust the battery temperature. However, when the ambient temperature is low, the battery thermal management system cannot perform cooling or the cooling effect is poor, which affects the battery life and battery output power stability. Summary of the invention

[0003] In response to the above-mentioned problems in the prior art, the purpose of the present application is to set a coaxial tube so that the coolant heats the refrigerant, thereby reducing the starting pressure requirement of the refrigerant drive device, improving the application of the thermal management system, and thereby improving the battery life and battery output power stability.

[0004] In order to solve the above problems, the present application provides a battery thermal management system, including a coolant circulation pipeline, a refrigerant circulation pipeline and a heat exchanger, wherein the coolant circulation pipeline flows through the outer surface of the battery module, and the coolant circulation pipeline exchanges heat with the refrigerant circulation pipeline through the heat exchanger;

[0005] A coaxial tube is provided on a part of the refrigerant circulation pipeline, and both ends of the coaxial tube are connected to the coolant circulation pipeline;

[0006] The refrigerant circulation pipeline includes a refrigerant driving device, and the refrigerant driving device and the heat exchanger are respectively arranged at two ends of a portion of the refrigerant circulation pipeline;

[0007] The coolant flowing through the coaxial tube is used to heat the refrigerant in the refrigerant circulation pipeline.

[0008] In an embodiment of the present application, the flow direction of the refrigerant in a portion of the refrigerant circulation pipeline is opposite to the flow direction of the coolant in the coaxial tube.

[0009] In the embodiment of the present application, a coaxial flow valve and a coaxial check valve are respectively provided at both ends of the coaxial tube.

[0010] In the embodiment of the present application, the coaxial flow valve includes an input end and two output ends, and the two output ends include the coaxial tube and the coolant circulation pipeline;

[0011] The coaxial flow valve is used to switch the output end to change the flow channel of the coolant.

[0012] In the embodiment of the present application, a control device is also included, and the control device is communicatively connected with the coaxial flow valve and the coaxial check valve respectively.

[0013] In an embodiment of the present application, the control device is used to adjust the opening and closing states of the coaxial flow valve and the coaxial check valve when the ambient temperature is lower than a preset temperature, so that the coolant in the coolant circulation pipeline flows through the coaxial tube.

[0014] In an embodiment of the present application, the coolant circulation pipeline includes a coolant driving device, and the coolant driving device is arranged at the input end of the coaxial tube.

[0015] In an embodiment of the present application, the coolant circulation pipeline includes a heater, and the coolant in the coolant circulation pipeline flows through the heat exchanger and the heater in sequence.

[0016] In an embodiment of the present application, the refrigerant circulation pipeline includes an expansion valve, and the refrigerant in the refrigerant circulation pipeline flows through the expansion valve and the heat exchanger in sequence.

[0017] On the other hand, the present application also provides a battery assembly, which includes a battery module and a battery thermal management system in an embodiment of the present application.

[0018] Due to the above technical solution, a battery thermal management system described in this application has the following beneficial effects:

[0019] By installing a coaxial tube outside part of the refrigerant circulation pipeline, the coolant flowing through the coaxial tube can heat the refrigerant in the refrigerant circulation pipeline. After the refrigerant absorbs heat, based on the principle of thermal expansion and contraction, the gas will expand and increase its volume, which will cause the pressure in the refrigerant circulation pipeline to increase. As a result, the starting pressure requirement of the refrigerant drive device is reduced, thereby increasing the application range of the thermal management system and thereby improving the battery life and battery output power stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments or prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a schematic diagram of the structure of a battery thermal management system provided in an embodiment of the present application;

[0022] Figure 2 It is a schematic diagram of the structure of the coaxial tube in the battery thermal management system provided in the embodiment of the present application.

[0023] Among them, 1-coolant circulation pipeline, 11-coolant driving device, 12-heater, 13-expansion water tank, 2-refrigerant circulation pipeline, 21-refrigerant driving device, 22-expansion valve, 23-condenser, 3-heat exchanger, 4-battery module, 5-coaxial tube, 6-coaxial flow valve, 7-coaxial check valve. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0025] The term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present application. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0026] Combination Figure 1-2 , introduces a battery thermal management system provided by an embodiment of the present application, including a coolant circulation pipeline 1, a refrigerant circulation pipeline 2 and a heat exchanger 3, the coolant circulation pipeline 1 flows through the outer surface of the battery module 4, and the coolant circulation pipeline 1 exchanges heat with the refrigerant circulation pipeline 2 through the heat exchanger 3; a coaxial tube 5 is provided on the outer sleeve of part of the refrigerant circulation pipeline 2, and both ends of the coaxial tube 5 are connected to the coolant circulation pipeline 1; the refrigerant circulation pipeline 2 includes a refrigerant driving device 21, and the refrigerant driving device 21 and the heat exchanger 3 are respectively arranged at both ends of the part of the refrigerant circulation pipeline 2; the coolant flowing through the coaxial tube 5 is used to heat the refrigerant in the refrigerant circulation pipeline 2.

[0027] In the embodiment of the present application, the coolant circulation pipeline 1 refers to a pipeline for circulating the coolant, specifically, the coolant flows through the outer surface of the battery module to adjust the temperature of the battery module 4; the refrigerant circulation pipeline 2 refers to a pipeline for circulating the refrigerant, specifically, the refrigerant is used to reduce the temperature of the coolant; the refrigerant and the coolant exchange temperature in the heat exchanger 3, specifically, the heat exchanger 3 can be a plate heat exchanger and a shell and tube heat exchanger, etc.

[0028] In the specific embodiment of the present application, the refrigerant flows through the heat exchanger 3, the corresponding part of the pipeline of the coaxial tube 5 and the refrigerant driving device 21 in sequence.

[0029] In an embodiment of the present application, a coaxial tube 5 is arranged on the outer surface of part of the refrigerant circulation pipeline 2 so that the coolant flowing through the coaxial tube 5 heats the refrigerant in the refrigerant circulation pipeline 2. After the refrigerant absorbs heat, based on the principle of thermal expansion and contraction, the gas expands and increases its volume when absorbing heat, thereby causing the pressure in the refrigerant circulation pipeline 2 to increase, thereby reducing the starting pressure requirement of the refrigerant drive device 21, thereby increasing the wide application of the thermal management system and thereby improving the battery life and battery output power stability.

[0030] In a specific embodiment of the present application, the refrigerant driving device 21 is a compressor.

[0031] In a specific embodiment of the present application, the cooling liquid may be a 50% ethylene glycol aqueous solution.

[0032] In the embodiment of the present application, the flow direction of the refrigerant in a part of the refrigerant circulation pipeline 2 is opposite to the flow direction of the cooling liquid in the coaxial tube 5 .

[0033] In the embodiment of the present application, by setting the flow direction of the refrigerant and the flow direction of the coolant in the coaxial tube 5 to be opposite, the relative flow velocity of the refrigerant and the coolant is increased, thereby improving the heat exchange efficiency.

[0034] In the specific embodiment of the present application, the coolant flows through the coaxial tube 5 and the heat exchanger 3 in sequence.

[0035] In the embodiment of the present application, a coaxial flow valve 6 and a coaxial check valve 7 are respectively provided at both ends of the coaxial tube 5 .

[0036] In the embodiment of the present application, the coaxial flow valve 6 is used to control the flow rate of the coolant flowing through the coaxial tube 5, and the coaxial check valve 7 is used to control the flow rate of the coolant flowing back to the coolant circulation pipeline 1.

[0037] In the embodiment of the present application, a coaxial flow valve 6 and a coaxial check valve 7 are respectively provided at both ends of the coaxial tube 5, so as to control the time node at which the coolant flows into the coaxial tube 5 and the flow rate of the coolant flowing into the coaxial tube 5, thereby improving the controllability of the refrigerant heating time and thereby improving the controllability of the battery thermal management system.

[0038] In the embodiment of the present application, the coaxial flow valve 6 includes an input end and two output ends, and the two output ends include a coaxial tube 5 and a coolant circulation pipeline 1; the coaxial flow valve 6 is used to switch the output end to change the flow channel of the coolant.

[0039] In the embodiment of the present application, the circulation channel of the coolant includes circulating in the coolant circulation pipeline 1 and flowing out of the coolant circulation pipeline 1 to the coaxial tube 5, and then flowing back to the coolant circulation pipeline 1 from the coaxial tube 5.

[0040] In the specific embodiment of the present application, the coaxial flow valve 6 is a three-way valve.

[0041] In the embodiment of the present application, by setting the coaxial flow valve 6 as two output ends and one input end, the coolant can be output to any one of the two output ends, or the coolant can be output to the two output ends separately, thereby improving the flexibility of the coolant flow and the flexibility of the application scenarios of the battery thermal management system.

[0042] In the embodiment of the present application, the battery thermal management system further includes a control device, which is respectively communicatively connected to the coaxial flow valve 6 and the coaxial check valve 7 .

[0043] In the embodiment of the present application, the control device is used to control the operation of the coaxial flow valve 6 and the coaxial check valve 7 .

[0044] In the embodiment of the present application, a control device is provided to realize electrical control of the coaxial valve and the coaxial check valve 7, thereby improving the control accuracy and control timeliness of the battery thermal management system, thereby improving the reliability of the battery thermal management system.

[0045] In an embodiment of the present application, the control device is used to adjust the opening and closing states of the coaxial flow valve 6 and the coaxial check valve 7 when the ambient temperature is lower than a preset temperature, so that the coolant in the coolant circulation pipeline 1 flows through the coaxial tube 5.

[0046] In a specific embodiment of the present application, the preset temperature may be -12 to -15°C.

[0047] In a specific embodiment of the present application, when the ambient temperature is lower than the preset temperature, the temperature of the coolant will be higher than the ambient temperature, thereby controlling the opening of the coaxial flow valve 6 and the coaxial check valve 7, so that the coolant flows through the coaxial tube 5 and heats the liquid in the refrigerant. As a result, the refrigerant absorbs heat, causing the pressure on one side of the refrigerant drive device 21 to increase, thereby reducing the starting pressure requirement of the refrigerant drive device 21, thereby achieving low-temperature refrigeration of the battery thermal management system.

[0048] In a specific embodiment of the present application, when the ambient temperature is lower than the preset temperature, the temperature difference between the refrigerant and the coolant can reach about 10 to 30°C. Specifically, the coolant temperature is higher than the refrigerant temperature, and the coolant temperature can be 20 to 30°C.

[0049] In an embodiment of the present application, the control device adjusts the opening and closing states of the coaxial flow valve 6 and the coaxial check valve 7 when the ambient temperature is lower than the preset temperature, so that the coolant in the coolant circulation pipeline 1 flows through the coaxial tube 5, thereby improving the application range of the thermal management system, and further improving the battery life and battery output power stability.

[0050] In the embodiment of the present application, the coolant circulation pipeline 1 includes a coolant driving device 11 , and the coolant driving device 11 is arranged at the input end of the coaxial tube 5 .

[0051] In a specific embodiment of the present application, the coolant driving device 11 is a water pump.

[0052] In a specific embodiment of the present application, the coolant may flow through the coolant driving device 11 , the coaxial tube 5 , and the heat exchanger 3 in sequence.

[0053] In the embodiment of the present application, the coolant circulation pipeline 1 includes a heater 12 , and the coolant in the coolant circulation pipeline 1 flows through the heat exchanger 3 and the heater 12 in sequence.

[0054] In the embodiment of the present application, the heater 12 is used to heat the coolant to increase the temperature of the battery module 4 .

[0055] In a specific embodiment of the present application, the control device is communicatively connected with the heater 12 .

[0056] In the embodiment of the present application, by providing a heater 12, the battery thermal management system can not only cool the battery module 4, but also keep the battery module 4 warm, thereby improving the breadth of application scenarios and application flexibility of the battery thermal management system.

[0057] In the embodiment of the present application, the refrigerant circulation pipeline 2 includes an expansion valve 22 , and the refrigerant in the refrigerant circulation pipeline 2 flows through the expansion valve 22 and the heat exchanger 3 in sequence.

[0058] In the embodiment of the present application, the expansion valve 22 is used to convert the medium-temperature and high-pressure liquid refrigerant into low-temperature and low-pressure wet steam through throttling.

[0059] In a specific embodiment of the present application, the expansion valve 22 is a thermal expansion valve 22 .

[0060] In a specific embodiment of the present application, the coolant circulation pipeline 1 may also include multiple temperature sensors T. Specifically, one temperature sensor is arranged at the output end of the heater 12, and one temperature sensor is arranged at the input end of the coolant driving device 11.

[0061] In a specific embodiment of the present application, the coolant driving device 11 is disposed between the coaxial tube 5 and the pipeline on the outer surface of the battery module 4 .

[0062] In a specific embodiment of the present application, an expansion water tank 13 is further provided on the coolant circulation pipeline 1 for storing the coolant.

[0063] In a specific embodiment of the present application, a pressure sensor P, a temperature and pressure sensor PT and multiple refrigerant filling ports C are also provided on the refrigerant circulation pipeline 2. Specifically, the input end of the refrigerant driving device 21 is sequentially provided with a refrigerant filling port and a pressure sensor P, and the output end of the refrigerant driving device 21 is sequentially provided with a refrigerant filling port and a temperature and pressure sensor PT.

[0064] In a specific embodiment of the present application, a condenser 23 is further provided on the refrigerant circulation pipeline 2, and the condenser 23 includes a condensing fan; specifically, the condenser 23 is arranged at the output end of the refrigerant driving device 21, and is located after the refrigerant filling port and the temperature and pressure sensor PT.

[0065] The working principle of the battery thermal management system in the embodiment of the present application is described below:

[0066] Under normal operating conditions, the output end of the coaxial flow valve 6 is connected to the coolant circulation pipeline 1, and the coolant cannot flow into the coaxial tube 5, so that the coolant flows in the coolant circulation pipeline 1, the refrigerant flows in the refrigerant circulation pipeline 2, and the coolant exchanges temperature with the refrigerant through the heat exchanger 3.

[0067] When the ambient temperature is lower than the preset temperature, the output end of the coaxial flow valve 6 changes from being connected to the coolant circulation pipeline 1 to being connected to the coaxial tube 5. At the same time, the coaxial check valve 7 is opened. That is to say, the coolant flows through the coaxial tube 5 and then flows back to the coolant circulation pipeline 1. The coolant heats the refrigerant to increase the pressure in the refrigerant circulation pipeline 2, thereby reducing the starting pressure requirement of the refrigerant drive device 21, thereby increasing the wide application of the thermal management system and thereby improving the battery life and battery output power stability.

[0068] The battery thermal management system in the embodiment of the present application has the following beneficial effects:

[0069] A coaxial tube 5 is installed on part of the refrigerant circulation pipeline 2 so that the coolant flowing through the coaxial tube 5 heats the refrigerant in the refrigerant circulation pipeline 2. After the refrigerant absorbs heat, based on the principle of thermal expansion and contraction, the gas will expand and increase its volume when absorbing heat, thereby causing the pressure in the refrigerant circulation pipeline 2 to increase, thereby reducing the starting pressure requirement of the refrigerant drive device 21, thereby increasing the wide application of the thermal management system and thereby improving the battery life and battery output power stability.

[0070] An embodiment of the present application also provides a battery assembly, which includes a battery module 4 and a battery thermal management system in an embodiment of the present application.

[0071] The above description has fully disclosed the specific implementation methods of the present application. It should be pointed out that any changes made by technicians familiar with the field to the specific implementation methods of the present application do not deviate from the scope of the claims of the present application. Accordingly, the scope of the claims of the present application is not limited to the above specific implementation methods.

Claims

1. A battery thermal management system, characterized in that: It comprises a coolant circulation pipeline (1), a refrigerant circulation pipeline (2) and a heat exchanger (3), wherein the coolant circulation pipeline (1) flows through the outer surface of a battery module (4), and the coolant circulation pipeline (1) exchanges heat with the refrigerant circulation pipeline (2) through the heat exchanger (3); A coaxial tube (5) is provided on a portion of the refrigerant circulation pipeline (2), and both ends of the coaxial tube (5) are connected to the coolant circulation pipeline (1); The refrigerant circulation pipeline (2) comprises a refrigerant driving device (21), and the refrigerant driving device (21) and the heat exchanger (3) are respectively arranged at two ends of a portion of the refrigerant circulation pipeline (2); The cooling liquid flowing through the coaxial tube (5) is used to heat the refrigerant in the refrigerant circulation pipeline (2).

2. The battery thermal management system according to claim 1, characterized in that: The flow direction of the refrigerant in a portion of the refrigerant circulation pipeline (2) is opposite to the flow direction of the cooling liquid in the coaxial tube (5).

3. The battery thermal management system according to claim 1, characterized in that: A coaxial flow valve (6) and a coaxial check valve (7) are respectively provided at both ends of the coaxial tube (5).

4. The battery thermal management system according to claim 3, characterized in that: The coaxial flow valve (6) comprises an input end and two output ends, wherein the two output ends comprise the coaxial tube (5) and the coolant circulation pipeline (1); The coaxial circulation valve (6) is used to switch the output end to change the circulation channel of the cooling liquid.

5. The battery thermal management system according to claim 3, characterized in that: It also includes a control device, which is communicatively connected to the coaxial flow valve (6) and the coaxial check valve (7) respectively.

6. The battery thermal management system according to claim 5, characterized in that: The control device is used to adjust the opening and closing states of the coaxial flow valve (6) and the coaxial check valve (7) when the ambient temperature is lower than a preset temperature, so that the coolant in the coolant circulation pipeline (1) flows through the coaxial tube (5).

7. The battery thermal management system according to claim 1, characterized in that: The coolant circulation pipeline (1) comprises a coolant driving device (11), and the coolant driving device (11) is arranged at the input end of the coaxial tube (5).

8. The battery thermal management system according to claim 1, characterized in that: The coolant circulation pipeline (1) comprises a heater (12), and the coolant in the coolant circulation pipeline (1) flows through the heat exchanger (3) and the heater (12) in sequence.

9. The battery thermal management system according to claim 1, characterized in that: The refrigerant circulation pipeline (2) comprises an expansion valve (22), and the refrigerant in the refrigerant circulation pipeline (2) flows through the expansion valve (22) and the heat exchanger (3) in sequence.

10. A battery assembly, characterized in that: It comprises a battery module (4) and a battery thermal management system as claimed in any one of claims 1 to 9.

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