Liquid cooling pipeline system and design method thereof

Abstract

The present application relates to the field of rail transit heat exchange technology, and specifically provides a liquid cooling pipeline system and a design method thereof, which is used in a locomotive power battery thermal management system, including a water tank, a heat exchanger, a water pump, a power battery end cooling pipeline, a heat exchanger water inlet pipe, a heat exchanger water outlet pipe, a water pump outlet pipe, a pipeline exhaust pipe and a pipeline water supply pipe; wherein the water pump, the heat exchanger and the power battery end cooling pipeline are connected in series through pipelines to form a circulation loop, the water tank is connected in parallel to the circulation loop through the pipeline exhaust pipe and the pipeline water supply pipe, and the connection position of the pipeline exhaust pipe and the circulation loop is set so that when the liquid cooling pipeline is in the exhaust stage, the liquid level of the coolant in the water tank continues to decrease. The liquid cooling pipeline system of the present application can be integrated into the locomotive power battery thermal management device, has a compact structure, saves space, and can solve problems such as low pipeline exhaust efficiency and water pump suction caused by coolant reflux.

Description

Technical Field

[0001] The present application relates to the field of rail transit heat exchange technology, and in particular to a liquid cooling pipeline system and a design method thereof. Background Art

[0002] Power batteries are core components of locomotives. The level of control over battery operating and storage temperatures is closely linked to their performance and lifespan. Power battery thermal management systems manage battery heat, ensuring optimal operating temperatures, enhancing safety, and extending battery life. Currently, most locomotive power battery thermal management systems utilize a combination of air cooling and liquid cooling. Liquid cooling utilizes water, ethylene glycol, or a refrigerant as a coolant, removing heat from the battery through a closed coolant circulation system.

[0003] However, during the coolant filling stage, due to the long pipelines, the use of a liquid filling pump will easily cause gas accumulation in the pipelines due to factors such as excessive filling speed. In addition, during the operation of the liquid cooling pipelines, the coolant in the pipelines will also produce some gas due to heat exchange, thereby affecting the function of the power battery thermal management system.

[0004] At present, the new energy vehicle field often uses expansion tanks to solve the exhaust problem in its power battery cooling pipes. However, due to the significant differences in locomotive size specification requirements and cooling performance requirements from new energy vehicles, this solution will cause some problems when used in the locomotive field. Specifically, the capacity and number of locomotive power battery packs are much higher than those of new energy vehicles, requiring a higher cooling effect, and the locomotive liquid cooling pipes are also much longer than those of new energy vehicles. Therefore, the water pump in the liquid cooling pipe system needs to provide a higher pressure than that of new energy vehicles to enable the coolant to circulate in the entire locomotive liquid cooling pipe; this results in the coolant in the circulation pipe flowing back to the expansion tank if the conventional new energy vehicle exhaust solution is adopted, resulting in the water pump being sucked empty. Therefore, there is an urgent need for a liquid cooling pipe system suitable for the locomotive power battery thermal management system. Summary of the Invention

[0005] The purpose of this application is to provide a liquid cooling pipeline system and a design method thereof, which are used in a locomotive power battery thermal management system, and can solve problems such as low pipeline exhaust efficiency and coolant reflux causing water pump suction.

[0006] The embodiments of the present application can be implemented through the following technical solutions:

[0007] A liquid cooling pipeline system for a locomotive power battery thermal management system, comprising a water tank, a heat exchanger, a water pump, a power battery end cooling pipeline, a heat exchanger water inlet pipe, a heat exchanger water outlet pipe, a water pump water outlet pipe, a pipeline exhaust pipe and a pipeline water supply pipe; the heat exchanger water inlet pipe is connected to the power battery end cooling pipeline and the heat exchanger, the heat exchanger water outlet pipe is connected to the heat exchanger and the water pump, the water pump water outlet pipe is connected to the water pump and the power battery end cooling pipeline, the heat exchanger, water pump and power battery end cooling pipeline are connected in series through the heat exchanger water inlet pipe, the heat exchanger water outlet pipe and the water pump water outlet pipe A circulation loop is formed; the water tank is connected in parallel to the circulation loop through the pipeline exhaust pipe and the pipeline water supply pipe, and the water pump outlet pipe is higher than the heat exchanger water inlet pipe and the heat exchanger outlet pipe; the pipeline water supply pipe is used to add coolant to the circulation loop, and the pipeline exhaust pipe is used to discharge the gas in the circulation loop into the water tank; the first port of the pipeline exhaust pipe is connected to the water tank, and the second port thereof is connected to the circulation loop, and the connection position of the second port and the circulation loop is set so that when the liquid cooling pipeline system is in the exhaust stage, the liquid level of the coolant in the water tank continues to decrease.

[0008] Furthermore, when the liquid cooling pipeline system is in the exhaust stage, the liquid flow rate flowing out of the water tank through the pipeline water supply pipe at the same time is greater than the liquid flow rate entering the water tank through the pipeline exhaust pipe.

[0009] Furthermore, when the liquid cooling pipe system is in the exhaust stage, the upper limit of the liquid coolant flow in the exhaust pipe of the pipe is 0.3m 3 / h, the lower limit of the flow rate of liquid coolant flowing out of the water tank through the pipeline water supply pipe is 0.3m 3 / h.

[0010] Furthermore, the second port of the pipeline exhaust pipe is connected to the heat exchanger water inlet pipe or the heat exchanger water outlet pipe, the height of the second port of the pipeline exhaust pipe and the circulation loop interface is h1, and the height of the highest point of the heat exchanger water inlet pipe and the heat exchanger water outlet pipe is h2, and the h1 and h2 satisfy:

[0011] h2-h1≤30mm.

[0012] Furthermore, the second port of the pipeline exhaust pipe is connected to the highest point between the heat exchanger water inlet pipe and the heat exchanger water outlet pipe.

[0013] Furthermore, the second port of the pipeline exhaust pipe is connected to the water outlet pipe of the water pump, and a valve is provided on the pipeline exhaust pipe, and the ratio of gas to liquid in the pipeline exhaust pipe is controlled by adjusting the valve opening.

[0014] Furthermore, it also includes a second pipeline exhaust pipe, the first port of the second pipeline exhaust pipe is connected to the pipeline exhaust pipe, and the second port is connected to the circulation loop.

[0015] Furthermore, the second end of the second pipeline exhaust pipe is connected to the water outlet pipe of the water pump.

[0016] Furthermore, a valve is provided on the second pipeline exhaust pipe.

[0017] Furthermore, the water tank includes an upper water chamber and a lower water chamber separated from each other, and the upper water chamber and the lower water chamber are connected through a water tank exhaust pipe arranged inside the water tank. The shell at the corresponding position of the upper port of the water tank exhaust pipe protrudes upward to form an upper air collecting area, and the upper port of the water tank exhaust pipe is connected to the upper air collecting area; a pressure relief valve is provided on the top of the lower water chamber; a liquid level measuring instrument is provided inside the lower water chamber; the first port of the pipeline exhaust pipe is connected to the upper part of the upper water chamber, and the first port of the pipeline water supply pipe is connected to the bottom of the upper water chamber.

[0018] Furthermore, the water tank also includes a water inlet, which is arranged at the top of the upper water chamber, and the water inlet is located at the highest point of the liquid cooling pipeline system.

[0019] Furthermore, the water injection port includes a second water injection port, which is connected to the upper water chamber.

[0020] Furthermore, the water injection port also includes a first water injection port, which is directly connected to the lower water chamber through a pipeline.

[0021] A method for designing a liquid cooling piping system, used to design the above-mentioned liquid cooling piping system, comprises the following steps:

[0022] S1: Set the position and layout of the water tank, heat exchanger, water pump and power battery cooling pipe according to the specifications of the locomotive power battery thermal management device used;

[0023] S2: Connect the pipes according to the position layout of the water tank, heat exchanger, water pump and power battery cooling pipes;

[0024] S3: Connect the second port of the pipeline exhaust pipe to one of the optional positions in the circulation loop to form a pipeline exhaust pipe arrangement scheme, and perform an exhaust phase test on the scheme;

[0025] S4: Determine whether the test result of S3 meets the stop condition. When the stop condition is met, the exhaust pipe arrangement plan is feasible; when the stop condition is not met, return to S3.

[0026] Furthermore, the stopping condition is specifically:

[0027] a. The liquid level H2 in the water tank at the end of the exhaust phase is less than the liquid level H1 in the water tank at the start of the exhaust phase;

[0028] b. After the exhaust phase, with the water pump running, the change in the liquid level in the water tank over a period of time does not exceed 8mm;

[0029] c. After the exhaust stage, when the water pump stops running, the change in the liquid level in the water tank over a period of time does not exceed 8mm.

[0030] The embodiments of the present application provide a liquid cooling pipeline system and a design method thereof, which have at least the following beneficial effects:

[0031] 1. The liquid cooling piping system of the present application can be integrated into a locomotive power battery thermal management device. To adapt to the shape and size of the thermal management device and to coordinate with other systems in the thermal management device, the components and connections of the liquid cooling piping system are rationally arranged, resulting in a compact structure and space saving.

[0032] 2. By connecting water tanks in parallel, the entire pipeline can be replenished and exhausted. By optimizing the position of the exhaust pipe, the exhaust efficiency in the pipeline is further improved to avoid excessive coolant backflow causing the water pump to suck air out of the system.

[0033] 3. The upper and lower separated water tanks are used. The design of the lower water tank can compensate the coolant of the upper water tank and adjust the gas pressure;

[0034] 4. By setting a water filling port on the water tank, the coolant is injected into the pipeline system through gravitational potential energy. Compared with the conventional method of injecting coolant through an injection pump, the operation is simpler and the injection operation can be completed without an additional injection pump. It also avoids the problem of air suffocation in the pipeline caused by the injection pump injecting liquid too quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of a locomotive power battery thermal management device used in the liquid cooling pipeline system of this application;

[0036] Figure 2 This is a schematic diagram of the overall structural layout of the liquid cooling pipeline system of this application;

[0037] Figure 3 This is a schematic diagram of the arrangement of the exhaust pipes of the liquid cooling pipe system according to an embodiment of the present application;

[0038] Figure 4 This is a schematic diagram of the arrangement of exhaust pipes of a liquid cooling pipe system according to another embodiment of the present application;

[0039] Figure 5 This is a schematic diagram of the arrangement of exhaust pipes of a liquid cooling pipe system according to another embodiment of the present application;

[0040] Figure 6 This is a schematic diagram of the coolant flow in the liquid cooling piping system of this application;

[0041] Figure 7This is a schematic diagram of the overall structure of the water tank in this application;

[0042] Figure 8 A top view of the water tank in this application;

[0043] Figure 9 for Figure 8 Middle AA section;

[0044] Figure 10 for Figure 8 Middle BB section;

[0045] Figure 11 This is a schematic diagram of the liquid level in the water tank at the beginning of the exhaust phase;

[0046] Figure 12 Schematic diagram of the liquid level in the water tank at the end of the exhaust phase.

[0047] Numbers in the figure

[0048] Water tank 1, shell 11, upper water chamber 111, lower water chamber 112, water inlet 12, first water inlet 121, second water inlet 122, exhaust pipe joint 13, water supply pipe joint 14, liquid level observation window 15, pressure relief valve 16, upper gas collecting area 17, water tank exhaust pipe 18, liquid level measuring instrument 19, heat exchanger 2, water pump 3, power battery end cooling pipeline 4, pipeline water supply pipe 5, water tank water supply pipe 51, pipeline exhaust pipe 6, heat exchanger water inlet pipe 7, heat exchanger water outlet pipe 8, water pump outlet pipe 9. DETAILED DESCRIPTION

[0049] Hereinafter, the present application will be further described based on preferred embodiments with reference to the accompanying drawings.

[0050] In addition, various components in the drawings are enlarged or reduced in size for ease of understanding, but this is not intended to limit the scope of protection of this application.

[0051] Words importing the singular include the plural and vice versa.

[0052] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or are the orientation or positional relationship in which the products of the embodiments of the present application are usually placed when in use, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 on the present application. In addition, in the description of the present application, in order to distinguish different units, words such as first and second are used in this specification, but these are not limited by the order of manufacture, nor can they be understood as indicating or implying relative importance. Their names may be different in the detailed description and claims of the present application.

[0053] The vocabulary in this specification is used to illustrate the embodiments of the present application, but is not intended to limit the present application. It should also be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or a communication between the two components. For those skilled in the art, the specific meanings of the above terms in this application can be specifically understood.

[0054] Now combined Figures 1-12 The present invention will be further described:

[0055] like Figure 1 The figure shows a thermal management device for locomotive power batteries. Mounted on the locomotive's roof, it provides thermal management, such as cooling and heating, for the locomotive power batteries located below it, keeping them operating within a suitable temperature range. Because the thermal management device is mounted on the locomotive's roof, it faces limitations such as size and shape to match the locomotive's design. This necessitates integrating multiple systems within the device's limited space, placing high demands on the installation and layout of each system.

[0056] This application provides a liquid cooling pipe system integrated in the above-mentioned thermal management device. In order to adapt to the shape and size of the thermal management device and to cooperate with other systems in the thermal management device, the components and connections in the liquid cooling pipe system are reasonably arranged, with a compact structure and space saving. Figure 2 The figure shows an overall structural diagram of an embodiment of the liquid cooling pipeline system of the present application, which includes a water tank 1, a heat exchanger 2, and a water pump 3, wherein the heat exchanger 2, the water pump 3 and the power battery end cooling pipeline 4 are connected by pipelines to form a series circulation loop to achieve cooling of the power battery; the water tank 1 is connected in parallel to the above-mentioned series circulation loop to achieve the functions of liquid replenishment and exhaust for the entire liquid cooling pipeline system.

[0057] Specifically, when used, the water tank 1, heat exchanger 2, water pump 3 and the connecting pipes therebetween are located inside the above-mentioned thermal management device, and the power battery end cooling pipe 4 is located outside the thermal management device; preferably, the heat exchanger 2 is located between the water tank 1 and the water pump 3, so that the liquid cooling pipe system can better adapt to the shape of the above-mentioned thermal management device and better cooperate with other systems in the thermal management device.

[0058] Specifically, combined Figure 6 The flow direction of the coolant is further explained. The water inlet on the upper part of the heat exchanger 2 is connected to the heat exchanger inlet pipe 7. The coolant from the power battery end cooling pipeline 4 flows into the water inlet of the heat exchanger 2 through the heat exchanger inlet pipe 7. The water outlet located at the lower part of the heat exchanger 2 is connected to the heat exchanger outlet pipe 8. The other end of the heat exchanger outlet pipe 8 is connected to the water inlet of the water pump 3. The coolant after heat exchange inside the heat exchanger 2 flows into the water pump 3 through the heat exchanger outlet pipe 8. The water outlet on the water pump 3 is connected to the water pump outlet pipe 9. The water pump outlet pipe 9 allows the coolant to flow back into the water inlet end of the power battery end cooling pipeline 4, thereby realizing a circulation loop of the coolant.

[0059] Specifically, based on the flow direction of the coolant, the water pump outlet pipe 9 is set higher than the heat exchanger inlet pipe 7 and the heat exchanger outlet pipe 8; in some preferred embodiments, the heat exchanger inlet pipe 7 is higher than the heat exchanger outlet pipe 8.

[0060] Specifically, the water tank 1 is connected in parallel to the circulation loop through the pipeline water supply pipe 5 and the pipeline exhaust pipe 6. The pipeline water supply pipe 5 is used to replenish the coolant in the water tank 1 into the pipeline system, and the pipeline exhaust pipe 6 is used to transfer the gas in the pipeline system to the water tank 1 for discharge.

[0061] Since the gas is light in weight and generally gathers at a high position in the pipeline, the conventional operation in this field is to connect one end of the pipeline exhaust pipe 6 to the highest position of the series circulation loop, that is, the highest point of the water pump outlet pipe 9. However, this position is located at the outlet of the water pump 3. The excessive pressure causes too much coolant to be diverted through the pipeline exhaust pipe 6 and flow into the water tank 1. After flowing into the water tank 1, this part of the coolant will be stored in the water tank 1 and will not flow back into the pipeline system, thus causing the water pump to be sucked empty.

[0062] Based on the above-mentioned water pump suction problem, the applicant has found that connecting the pipeline exhaust pipe 6 to a specific position of the pipeline system can, on the one hand, avoid the above-mentioned water pump suction phenomenon, and on the other hand, ensure the exhaust effect of the pipeline. When the pipeline exhaust pipe 6 is connected to a specific position of the pipeline system, the liquid level of the coolant in the water tank 1 continues to drop during the exhaust stage of the liquid cooling pipeline system; preferably, at the same time during the exhaust stage, the liquid flow rate flowing out of the water tank 1 through the pipeline water supply pipe 5 is greater than the liquid flow rate entering the water tank 1 through the pipeline exhaust pipe 6; preferably, during the exhaust stage, the upper limit of the liquid coolant flow rate in the pipeline exhaust pipe 6 is 0.3m 3 / h, the lower limit of the flow rate of the liquid coolant flowing out of the water tank 1 through the pipeline water supply pipe 5 is 0.3m 3 / h.

[0063] The following are some specific arrangements of the exhaust pipe 6:

[0064] In some embodiments, as Figure 3 As shown, the first port of the pipeline exhaust pipe 6 is connected to the water tank 1, the heat exchanger water inlet pipe 7 is higher than the heat exchanger water outlet pipe 8, and the second port of the pipeline exhaust pipe 6 is connected to the highest point in the heat exchanger water inlet pipe 7. At this time, when the liquid cooling pipeline system is in the exhaust stage, the liquid level of the coolant in the water tank 1 continues to decrease.

[0065] In some other embodiments, the first port of the pipeline exhaust pipe 6 is connected to the water tank 1, the heat exchanger water inlet pipe 7 is higher than the heat exchanger water outlet pipe 8, the height of the interface between the second port of the pipeline exhaust pipe 6 and the heat exchanger water inlet pipe 7 is h1, and the height of the highest point between the heat exchanger water inlet pipe 7 and the heat exchanger water outlet pipe 8 is h2. When h2-h1≤30mm is satisfied, when the liquid cooling pipeline system is in the exhaust stage, the liquid level of the coolant in the water tank 1 continues to decrease.

[0066] In some other embodiments, such as Figure 4 As shown, the first port of the pipeline exhaust pipe 6 is connected to the water tank 1, and the second port thereof is connected to the highest point of the water pump outlet pipe 9. A valve is provided on the pipeline exhaust pipe 6. By adjusting the valve opening, the ratio of gas to liquid in the pipeline exhaust pipe 6 is controlled, so that the liquid level of the coolant in the water tank 1 continues to decrease during the exhaust stage.

[0067] In some other embodiments, such as Figure 5 As shown, the system further includes a second exhaust pipe 61, the first end of which is connected to the main exhaust pipe 6, and the second end of which is connected to the circulation loop. Furthermore, valves are provided on both the main exhaust pipe 6 and the second exhaust pipe 61. The provision of multiple exhaust pipes further enhances the exhaust effect. The opening of the valves controls the gas-liquid ratio within the exhaust pipes, ensuring that the coolant level in the water tank 1 continuously decreases during the exhaust phase.

[0068] In some other embodiments, the diameter of the pipeline water supply pipe 5 is larger than the diameter of the pipeline exhaust pipe 6 to further ensure that the liquid flow rate flowing out of the water tank 1 through the pipeline water supply pipe 5 is greater than the liquid flow rate entering the water tank 1 through the pipeline exhaust pipe 6 at the same time.

[0069] In some other embodiments, the liquid cooling pipeline system further includes a plurality of temperature sensors, which are respectively arranged on each pipeline to monitor the water temperature in the system in real time.

[0070] This application provides a design method for a liquid cooling piping system, comprising the following steps:

[0071] S1: Set the position arrangement of the water tank 1, heat exchanger 2, water pump 3 and power battery end cooling pipe 4 according to the specifications of the locomotive power battery thermal management device used;

[0072] S2: Connect the water tank 1, heat exchanger 2, water pump 3 and power battery cooling pipe 4 according to their positional arrangement;

[0073] S3: Connect the second port of the pipeline exhaust pipe 6 to one of the optional positions in the circulation loop to form a pipeline exhaust pipe arrangement scheme and perform exhaust phase testing;

[0074] S4: Determine whether the test result of S3 meets the stop condition. When the stop condition is met, the exhaust pipe arrangement plan is feasible; when the stop condition is not met, return to S3.

[0075] Specifically, the stopping conditions include:

[0076] a. The liquid level H2 in the water tank 1 at the end of the exhaust phase is less than the liquid level H1 in the water tank 1 at the start of the exhaust phase;

[0077] b. After the exhaust phase, with the water pump running, the change in the liquid level in the water tank 1 over a period of time does not exceed 8 mm;

[0078] c. After the exhaust stage, when the water pump stops running, the change in the liquid level height in the water tank 1 within a period of time does not exceed 8 mm.

[0079] The following combination Figure 7-10 The structure of the water tank 1 is further described:

[0080] The water tank 1 includes a shell 11, whose overall shape is adapted to the above-mentioned thermal management device. Its interior is divided into an upper water chamber 111 and a lower water chamber 112. The upper water chamber 111 is located above the lower water chamber 112, and the two water chambers are separated by a partition.

[0081] Specifically, an exhaust pipe joint 13 and a water supply pipe joint 14 are respectively provided on the upper and lower outer sides of the shell 11. One end of the exhaust pipe joint 13 is connected to the first port of the pipeline exhaust pipe 6, and the other end is connected to the upper end of the upper water chamber 111; one end of the water supply pipe joint 14 is connected to the first port of the pipeline water supply pipe 5, and the other end is connected to the water tank water supply pipe 51. The water tank water supply pipe 51 has the same diameter as the pipeline water supply pipe 5. The mouth of the water tank water supply pipe 51 passes through the interior of the lower water chamber 112 and is connected to the lower end of the upper water chamber 111. When the coolant in the liquid cooling pipeline system is insufficient, the coolant in the upper water chamber 111 flows into the circulation loop system through the water tank water supply pipe 51 and the pipeline water supply pipe 5 in turn for replenishment.

[0082] Specifically, a vertical water tank exhaust pipe 18 is provided inside the water tank 1, and the upper water chamber 111 is connected to the lower water chamber 112 through the water tank exhaust pipe 18; the shell 11 at the position corresponding to the upper port of the water tank exhaust pipe 18 bulges upward to form an upper gas collecting area 17, and the upper port of the water tank exhaust pipe 18 is connected to the upper gas collecting area 17, that is, the plane where the upper port of the water tank exhaust pipe 18 is located is lower than the top end surface of the shell 11 at the upper gas collecting area 17, and not lower than the top end surface of the shell 11 at other positions except the upper gas collecting area 17, so that the gas in the upper water chamber 111 can gather in the upper gas collecting area 17 and enter the lower water chamber 112 through the water tank exhaust pipe 18 in the working state; preferably, the bottom of the shell 11 at the position corresponding to the lower port of the water tank exhaust pipe 18 bulges downward to form a lower gas collecting area, and the lower port of the water tank exhaust pipe 18 is connected to the lower gas collecting area.

[0083] Specifically, the water tank 1 also includes a pressure relief valve 16, which is arranged at the top of the lower water chamber 112. The pressure relief valve 16 automatically opens and closes according to the gas pressure in the lower water chamber 112. When the gas pressure in the lower water chamber 112 is too high, the pressure relief valve 16 automatically opens to discharge the gas in the lower water chamber 112 to relieve the pressure.

[0084] Specifically, the water tank 1 also includes a liquid level measuring instrument 19 and a liquid level observation window 15. The liquid level measuring instrument 19 is arranged inside the lower water chamber 112, and the liquid level observation window 15 is arranged on the outside of the lower water chamber 112 and the corresponding position of the liquid level measuring instrument 19, and is used to monitor and observe the position of the coolant in the lower water chamber 112.

[0085] In some preferred embodiments, a water inlet 12 is further provided at the top of the upper water chamber 111, and the water inlet 12 is located at the highest point of the entire liquid cooling pipeline system, so that the coolant injected through the water inlet 12 can flow into various parts of the system better by virtue of gravity potential energy; specifically, before the liquid cooling pipeline system works, the coolant is injected from the water inlet 12 to fill the entire liquid cooling pipeline with coolant. Compared with the conventional method of injecting coolant through a water pump, the operation is simpler and the injection operation can be completed without an additional water pump, and the problem of air suffocation in the pipeline caused by the water pump injecting too quickly is also avoided.

[0086] Specifically, the water injection port 12 includes a first water injection port 121 and a second water injection port 122 , wherein the first water injection port 121 is directly connected to the lower water chamber 112 through a pipeline, and the second water injection port 122 is connected to the upper water chamber 111 .

[0087] The following further explains the steps and working principle of the liquid cooling pipe system of this application:

[0088] When the liquid cooling pipeline system is in the filling stage before starting to work, open the second water filling port 122 and pour coolant into the upper water chamber 111 through it. At this time, the coolant will flow into the entire liquid cooling pipeline through the water tank water supply pipe 51 and the pipeline exhaust pipe 6 until the entire pipeline and the upper water chamber 111 are filled. Since the first water filling port 121 and the pressure relief valve 16 are closed at this time, no coolant flows into the lower water chamber 112. When the coolant overflows from the second water filling port 122, it indicates that the entire pipeline system and the upper water chamber 111 are filled with coolant. At this time, close the second water filling port 122, open the first water filling port 121, and inject coolant into the lower water chamber 112 through it until the coolant level in the lower water chamber 121 reaches such a level. Figure 11 When the lower portion is the coolant area and the upper portion is the gas area, the first water inlet 121 is closed to complete the liquid filling stage. The coolant area in the lower water chamber 112 can compensate for the coolant in the upper water chamber so that the upper water chamber is always filled with coolant. The gas area in the lower water chamber 112 can regulate the air pressure in the entire system. When there is too much gas, it can be discharged from the water tank 1 through the exhaust valve.

[0089] After the filling stage is completed, the exhaust stage begins. At this time, the water pump 3 is started, and the coolant in the circulation loop and the residual gas all flow in the pipeline. The gas in the pipeline flows into the upper water chamber 111 of the water tank 1 through the pipeline exhaust pipe 6. Since the upper water chamber 111 is in a state of being filled with coolant, the gas will gather in the upper gas collecting area 17 and flow into the lower water chamber 112 through the water tank exhaust pipe 18, and finally gather in the gas area above the lower water chamber 112. When the pressure in the gas area is too high, the pressure relief valve 16 is opened to discharge the water tank 1, thereby realizing the exhaust of the entire liquid cooling pipeline system; at this stage, the gas in the circulation loop continuously enters the water tank 1, and the coolant in the circulation loop is insufficient. The coolant in the upper water chamber 111 is replenished into the circulation loop by the pipeline water supply pipe 5. The coolant in the upper water chamber 111 is reduced, and the coolant in the lower water chamber 112 is compensated to the upper water chamber 111 through the water tank exhaust pipe 18. Therefore, at this stage, the liquid level of the coolant in the lower water chamber 112 continues to decrease. Figure 11 and Figure 12 As shown, the liquid level H2 at the end of the exhaust phase is lower than the liquid level H1 at the start of the exhaust phase.

[0090] When the exhaust stage is over, the liquid level height area of ​​the coolant in the lower water chamber 112 is stable. At this time, the liquid cooling pipeline system enters the working stage. The coolant with higher temperature from the cooling pipeline 4 at the power battery end flows into the heat exchanger 2 through the heat exchanger water inlet pipe 7. The heat exchange is carried out in the heat exchanger 2 to obtain the coolant with lower temperature, which flows into the water pump 3 through the heat exchanger outlet pipe 8, and then flows back to the cooling pipeline 4 at the power battery end through the water pump outlet pipe 9 by the water pump 3, thereby forming a circulation loop to cool the power battery.

[0091] The above is a detailed introduction to the specific implementation methods of the present application. For those skilled in the art, several improvements and modifications can be made to the present application without departing from the principles of the present application. These improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A liquid cooling pipeline system for a locomotive power battery thermal management system, comprising a water tank (1), a heat exchanger (2), a water pump (3), a power battery end cooling pipeline (4), a heat exchanger water inlet pipe (7), a heat exchanger water outlet pipe (8), a water pump water outlet pipe (9), a pipeline exhaust pipe (6) and a pipeline water supply pipe (5); the heat exchanger water inlet pipe (7) is connected to the power battery end cooling pipeline (4) and the heat exchanger (2), the heat exchanger water outlet pipe (8) is connected to the power battery end cooling pipeline (4) and the heat exchanger (2), and the heat exchanger water outlet pipe (8) is connected to the power battery end cooling pipeline (4) and the heat exchanger (2). The heat exchanger (2) and the water pump (3) are connected, the water pump outlet pipe (9) is connected to the water pump (3) and the power battery end cooling pipeline (4), the heat exchanger (2), the water pump (3) and the power battery end cooling pipeline (4) are connected in series by the heat exchanger water inlet pipe (7), the heat exchanger water outlet pipe (8) and the water pump outlet pipe (9) to form a circulation loop; the water tank (1) is connected in parallel to the circulation loop through the pipeline exhaust pipe (6) and the pipeline water supply pipe (5), and is characterized in that: The water pump outlet pipe (9) is higher than the heat exchanger water inlet pipe (7) and the heat exchanger water outlet pipe (8); The pipeline water supply pipe (5) is used to add coolant to the circulation loop, and the pipeline exhaust pipe (6) is used to discharge the gas in the circulation loop into the water tank (1); The first end of the pipeline exhaust pipe (6) is connected to the water tank, and the second end thereof is connected to the circulation loop. The connection position of the second end and the circulation loop is set so that when the liquid cooling pipeline system is in the exhaust phase, the liquid level of the coolant in the water tank (1) continues to decrease; The second port is connected to the heat exchanger water inlet pipe (7) or the heat exchanger water outlet pipe (8), and the height h1 of the interface position between the second port and the circulation loop and the height h2 of the highest point of the heat exchanger water inlet pipe (7) and the heat exchanger water outlet pipe (8) satisfy: h2-h1≤30mm; Alternatively, the second port is connected to a water pump outlet pipe (9), and a valve is provided on the pipeline exhaust pipe (6), and the ratio of gas to liquid in the pipeline exhaust pipe (6) is controlled by adjusting the valve opening.

2. The liquid cooling pipeline system according to claim 1, characterized in that: When the liquid cooling pipeline system is in the exhaust phase, at the same time, the liquid flow rate flowing out of the water tank (1) through the pipeline water supply pipe (5) is greater than the liquid flow rate entering the water tank (1) through the pipeline exhaust pipe (6).

3. The liquid cooling pipeline system according to claim 2, characterized in that: When the liquid cooling pipeline system is in the exhaust stage, the upper limit of the liquid cooling liquid flow in the pipeline exhaust pipe (6) is 0.3m 3 / h, the lower limit of the flow rate of the liquid coolant flowing out of the water tank (1) through the pipeline water supply pipe (5) is 0.3m 3 / h.

4. The liquid cooling pipeline system according to claim 1, characterized in that: The second end of the pipeline exhaust pipe (6) is connected to the highest point between the heat exchanger water inlet pipe (7) and the heat exchanger water outlet pipe (8).

5. The liquid cooling pipeline system according to claim 1, characterized in that: It also includes a second pipeline exhaust pipe (61), wherein a first port of the second pipeline exhaust pipe (61) is connected to the pipeline exhaust pipe (6), and a second port is connected to the circulation loop.

6. The liquid cooling pipeline system according to claim 5, characterized in that: The second end of the second pipeline exhaust pipe (61) is connected to the water pump outlet pipe (9).

7. The liquid cooling pipeline system according to claim 6, characterized in that: The second pipeline exhaust pipe is provided with a valve.

8. The liquid cooling pipeline system according to claim 1, characterized in that: The water tank (1) comprises an upper water chamber (111) and a lower water chamber (112) separated from each other, the upper water chamber (111) and the lower water chamber (112) being connected via a water tank exhaust pipe (18) provided inside the water tank (1), the housing (11) at a position corresponding to the upper port of the water tank exhaust pipe (18) protruding upwards to form an upper gas collecting area (17), and the upper port of the water tank exhaust pipe (18) is connected to the upper gas collecting area (17); A pressure relief valve (16) is provided on the top of the lower water chamber (112); A liquid level measuring instrument (19) is provided inside the lower water chamber (112); The first port of the pipeline exhaust pipe (6) is connected to the upper part of the upper water chamber (111), and the first port of the pipeline water supply pipe (5) is connected to the bottom of the upper water chamber (111).

9. The liquid cooling pipeline system according to claim 8, characterized in that: The water tank (1) further comprises a water injection port (12), wherein the water injection port (12) is arranged at the top of the upper water chamber (111), and the water injection port (12) is located at the highest point of the liquid cooling pipeline system.

10. The liquid cooling pipeline system according to claim 9, characterized in that: The water injection port (12) includes a second water injection port (122) which is in communication with the upper water chamber (111).

11. The liquid cooling pipeline system according to claim 10, characterized in that: The water injection port (12) further comprises a first water injection port (121), which is directly connected to the lower water chamber (112) through a pipeline.

12. A design method for designing the liquid cooling piping system according to claim 1, characterized in that: The following steps are involved: S1: setting the position arrangement of the water tank (1), the heat exchanger (2), the water pump (3) and the power battery end cooling pipeline (4) according to the specification requirements of the applied locomotive power battery thermal management device; S2: Connecting the pipes according to the positional arrangement of the water tank (1), the heat exchanger (2), the water pump (3) and the power battery end cooling pipe (4); S3: Connecting the second end of the pipeline exhaust pipe (6) to one of the optional positions in the circulation loop to form a pipeline exhaust pipe arrangement scheme, and performing an exhaust phase test on the pipeline exhaust pipe arrangement scheme; S4: Determine whether the test result of S3 meets the stop condition. If the stop condition is met, the exhaust pipe arrangement scheme of the pipeline is feasible; When the stop condition is not met, return to S3.

13. The design method according to claim 12, characterized in that: The stop conditions are specifically: a. At the end of the exhaust phase, the liquid level H2 in the water tank (1) is less than the liquid level H1 in the water tank (1) at the start of the exhaust; b. After the exhaust phase, under the condition that the pump is running, the change in the liquid level height in the water tank (1) over a period of time does not exceed 8 mm; c. After the exhaust phase is completed, under the condition that the water pump stops running, the change value of the liquid level height in the water tank (1) within a period of time does not exceed 8mm.

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