A coolant replacement method, device and application

Abstract

The application relates to the engine technical field, and discloses a cooling liquid replacement method, device and application, which comprises the following steps: performing test residual water blowing on an engine after testing; replacing the cooling liquid of the engine for multiple times by adopting multiple preset freezing point value cooling liquids; judging whether the replaced cooling liquid in the engine reaches the freezing point value of the factory cooling liquid; if yes, the cooling liquid replacement of the engine is completed; if not, the cooling liquid replacement is continuously performed until the cooling liquid in the engine reaches the freezing point value of the factory cooling liquid. The cooling liquid replacement method is used for replacing the cooling liquid of a fuel cell engine, the use amount of the cooling liquid is greatly saved, the cost is reduced, the replacement time is shortened, the efficiency is improved, the waste liquid amount is greatly reduced, the waste liquid storage cost and treatment cost are reduced, and the application is more energy-saving and environment-friendly.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a method, apparatus and application for coolant replacement. Background Technology

[0002] Currently, there are two testing methods for fuel cell engines: coolant testing and deionized water testing. Deionized water testing is more widely used due to its low cost. However, the water left after deionized water testing is prone to freezing in low winter temperatures, which can affect the product's performance. Moreover, when adding coolant later, the residual water can affect the coolant concentration, thereby affecting the freezing point and the overall performance.

[0003] In existing technologies, residual water is purged after testing, and then the fuel cell engine is replaced with coolant, which can basically solve the above problems. However, due to the very complex internal flow channels of the fuel cell engine, it is difficult to completely purge the residual water. When replacing the coolant, a large amount of coolant and a long replacement time are required to reach the freezing point value required by the factory. This method is costly and inefficient. Summary of the Invention

[0004] To address the challenges of thoroughly cleaning residual water during testing due to the complex internal flow channels of the engine, and the need for large amounts of coolant and extended replacement time to achieve the factory-required freezing point during engine coolant replacement, this invention provides a coolant replacement method, apparatus, and application.

[0005] The technical content of this invention is as follows:

[0006] A method for replacing coolant includes the following steps:

[0007] After the test is completed, the engine is purged of residual water.

[0008] The engine coolant is replaced multiple times by using coolant with multiple preset freezing point values.

[0009] Determine whether the coolant inside the engine has reached the factory-set freezing point after replacement;

[0010] If yes, the engine coolant replacement is complete; if not, continue the coolant replacement process until the coolant inside the engine reaches the factory-set freezing point.

[0011] Furthermore, the preset freezing point value of the coolant is not greater than the freezing point value of the standard coolant.

[0012] Furthermore, the coolant is replaced no less than 5 times, and the engine and pipelines are purged after each coolant replacement.

[0013] Furthermore, the coolant replacement is performed for the final replacement using coolant with a standard freezing point value.

[0014] According to the above-described coolant replacement method, the present invention provides a coolant replacement device for implementing the coolant replacement method described above, comprising a coolant replacement branch, a standard coolant tank, a compressed air supply component, and a recovery tank, wherein the recovery tank, the coolant replacement branch, the standard coolant tank, and the compressed air supply component are connected in sequence.

[0015] Furthermore, the recovery liquid tank, the standard coolant tank, and the compressed air supply assembly are all equipped with solenoid valves.

[0016] Furthermore, it also includes a water pump, which is installed on the pipeline between the standard coolant tank and the compressed air supply assembly.

[0017] According to the application of the coolant replacement device described above in a fuel cell engine, the coolant replacement branch includes multiple sets, the multiple sets of coolant replacement branches are connected in parallel, the fuel cell engine is connected in parallel with the multiple sets of coolant replacement branches, and the standard coolant tank, the compressed air supply component and the fuel cell engine are connected in sequence.

[0018] Furthermore, each of the coolant replacement branches is equipped with a coolant tank and a solenoid valve. Each solenoid valve comprises two sets, which are respectively installed on the inlet and outlet pipes of the coolant tank.

[0019] The application of the coolant replacement device according to any one of the above claims in multiple fuel cell engines includes multiple fuel cell engines. The coolant replacement branch includes multiple sets, which are connected in series. Each coolant replacement branch is provided with two sets of solenoid valves, and the multiple fuel cell engines are respectively arranged between the two sets of solenoid valves.

[0020] The beneficial effects of this invention include the following:

[0021] (1) The coolant replacement method of the present invention replaces the coolant in the fuel cell engine, which greatly saves the amount of coolant used, reduces the cost, shortens the replacement time, and improves efficiency.

[0022] (2) By replacing the coolant in the fuel cell engine using the coolant replacement method of the present invention, the amount of waste liquid generated is greatly reduced, thereby reducing the cost of waste liquid storage and treatment, and making it more energy-efficient and environmentally friendly. Attached Figure Description

[0023] Figure 1 This is a schematic flowchart of the coolant replacement method of the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of the coolant replacement device of the present invention applied to a fuel cell engine.

[0025] Figure 3 This is a schematic diagram of the structure of the coolant replacement device of the present invention applied to multiple fuel cell engines.

[0026] in:

[0027] 1-Recovery liquid tank;

[0028] 2-Coolant displacement branch;

[0029] 3-coolant tank;

[0030] 4-Solenoid valve;

[0031] 5 - Standard coolant tank;

[0032] 6-Water pump;

[0033] 7- Compressed air supply components;

[0034] 8- Fuel cell engine. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] Combination Figure 1 As shown, the present invention provides a coolant replacement method, comprising the following steps:

[0038] After the test is completed, the engine is purged of residual water.

[0039] The engine coolant is replaced multiple times by using coolant with multiple preset freezing point values.

[0040] Determine whether the coolant inside the engine has reached the factory-set freezing point after replacement;

[0041] If yes, the engine coolant replacement is complete; if not, continue the coolant replacement process until the coolant inside the engine reaches the factory-set freezing point.

[0042] Furthermore, the preset freezing point value of the coolant is not greater than the freezing point value of the standard coolant, and the preset freezing point values ​​of the multiple coolants are different.

[0043] Furthermore, the coolant is replaced no less than 5 times, and the engine and pipelines are purged after each coolant replacement.

[0044] Furthermore, the coolant replacement is performed for the final replacement using coolant with a standard freezing point value.

[0045] Example 2

[0046] To further verify the coolant replacement method provided in Example 1, this example specifically provides a coolant replacement method. The factory-installed coolant freezing point is set to no more than -40℃, the standard coolant freezing point is -45℃, and four preset cooling point values ​​are set: -40℃, -30℃, -20℃, and -10℃. The coolant replacement is performed through the following steps:

[0047] After the test is completed, the engine is purged of residual water.

[0048] After purging, the engine was purged four times by setting the preset freezing point values ​​of the coolant to -40℃, -30℃, -20℃, and -10℃.

[0049] When the engine is first replaced with coolant at -10℃, the replaced coolant can be recycled as waste liquid.

[0050] When the engine is purged with coolant at -20°C for the second time, the cooling point of the purged coolant will be approximately -10°C, and it will be reserved for the first purging of the next engine.

[0051] When the engine is purged for the third time with coolant at -30°C, the cooling point of the purged coolant will be approximately -20°C, and it will be reserved for the second purging of the next engine.

[0052] When the engine is purged for the fourth time with coolant at -40°C, the freezing point of the purged coolant will be approximately -30°C, and it will be reserved for the third purging of the next engine.

[0053] Finally, the engine is replaced for the fifth time with coolant with a standard freezing point of -45°C. After the coolant in the engine reaches the factory-required freezing point, the coolant is purged. The freezing point of the replaced coolant is about -40°C. This coolant and the purged coolant are reserved for the fourth replacement of the next engine.

[0054] After each coolant replacement, the engine and piping were purged with coolant, and the purged coolant was recovered.

[0055] The coolant that has been replaced and recovered can be recycled and reused to replace the coolant in the next engine.

[0056] The engine coolant is replaced multiple times using coolant with multiple preset freezing point values. The replacement order is from the highest temperature of the preset freezing point value to the lowest temperature. Each replacement uses one preset freezing point value. After the replacement is completed, it is determined whether the coolant inside the engine has reached the factory freezing point value. If it has, the coolant replacement ends. If not, the next preset freezing point value coolant is selected for replacement. This cycle is repeated until the coolant inside the engine reaches the factory freezing point value.

[0057] Example 3

[0058] According to the coolant replacement method provided in Example 1, combined with Figure 2 As shown, this embodiment provides a coolant replacement device that implements any of the coolant replacement methods described above. The device includes a coolant replacement branch 2, a standard coolant tank 5, a compressed air supply component 7, and a recovery tank 1. The recovery tank 1, the coolant replacement branch 2, the standard coolant tank 5, and the compressed air supply component 7 are connected in sequence.

[0059] Furthermore, the recovery liquid tank 1, the standard coolant tank 5, and the compressed air supply assembly 7 are all equipped with solenoid valves 4.

[0060] Furthermore, it also includes a water pump 6, which is installed on the pipeline between the standard coolant tank 5 and the compressed air supply assembly 7.

[0061] According to the application of the coolant replacement device described above in a fuel cell engine, the coolant replacement branch 2 includes multiple sets, the multiple sets of coolant replacement branch 2 are connected in parallel, the fuel cell engine 8 is connected in parallel with the multiple sets of coolant replacement branch 2, and the standard coolant tank 5, the compressed air supply component 7 and the fuel cell engine 8 are connected in sequence.

[0062] Furthermore, each of the coolant replacement branch lines 2 is equipped with a coolant tank 3 and a solenoid valve 4. Each solenoid valve 4 includes two sets, and the two sets of solenoid valves 4 are respectively installed on the inlet and outlet pipes of the coolant tank 3.

[0063] This invention can be configured with multiple coolant replacement branches and multiple coolant tanks corresponding to different freezing point values, according to needs and factory requirements, to perform multiple replacement processes.

[0064] Example 4

[0065] To further investigate the implementation of the coolant replacement method, this embodiment, in conjunction with Example 3, provides an application of a coolant replacement device in a fuel cell engine. The device is applied to a fuel cell engine, such as... Figure 2 As shown, it includes four coolant displacement branches 2 connected in parallel. Each of the four coolant displacement branches 2 is equipped with a coolant tank 3 and two sets of solenoid valves 4. The two sets of solenoid valves 4 are respectively installed on the inlet and outlet pipes of the coolant tank 3. The coolant tanks 3 of the four coolant displacement branches 2 are -10℃ coolant tank, -20℃ coolant tank, -30℃ coolant tank, and -40℃ coolant tank, respectively. The standard coolant tank is a -45℃ coolant tank.

[0066] The number of coolant replacement branches 2 can be set according to needs and factory requirements, and then multiple coolant tanks 3 are set with corresponding freezing point values.

[0067] In this embodiment, the factory requirement for the coolant freezing point of the fuel cell engine 8 is set to not exceed -40℃, the standard coolant freezing point is set to -45℃, and then four freezing point values ​​are set in sequence: -40℃, -30℃, -20℃, and -10℃, which correspond to the coolant tanks at -40℃, -30℃, -20℃, and -10℃, respectively.

[0068] The coolant replacement of this fuel cell engine is performed through the following steps:

[0069] First, open the solenoid valves on the recovery fluid tank, the compressed air supply assembly, and the compressed air supply assembly itself. Clean compressed air supplied by the compressed air supply assembly passes sequentially through the solenoid valves on the compressed air supply assembly, the fuel cell engine, and the recovery fluid tank, purging residual water from the fuel cell engine into the recovery fluid tank. After continuously purging the fuel cell engine as needed or for a specified time, close the solenoid valves on the compressed air supply assembly, completing the residual test water purging of the fuel cell engine.

[0070] Next, open the solenoid valve and water pump on the outlet pipe of the -10℃ coolant tank. The approximately -10℃ coolant in the -10℃ coolant tank flows sequentially through the solenoid valve on the outlet pipe of the -10℃ coolant tank, the water pump, the fuel cell engine, and the solenoid valve on the recovery tank, before flowing into the recovery tank.

[0071] When all the coolant in the -10℃ coolant tank has flowed out, close the solenoid valve and water pump on the outlet pipe of the -10℃ coolant tank, open the solenoid valve on the compressed air supply component, and the clean compressed air supplied by the compressed air supply component passes through the solenoid valve on the compressed air supply component, the fuel cell engine and the solenoid valve on the recovery tank in sequence, purging the approximately -10℃ coolant in the fuel cell engine and pipeline into the recovery tank.

[0072] After continuously purging the fuel cell engine and pipelines as needed or at specified intervals, close the solenoid valve on the compressed air supply component to complete the first coolant replacement of the engine.

[0073] Next, open the solenoid valve on the inlet pipe of the -10℃ coolant tank, the solenoid valve on the outlet pipe of the -20℃ coolant tank, and the water pump. The approximately -20℃ coolant in the -20℃ coolant tank flows sequentially through the solenoid valve on the outlet pipe of the -20℃ coolant tank, the water pump, the fuel cell engine, and the solenoid valve on the inlet pipe of the -10℃ coolant tank, before flowing into the -10℃ coolant tank.

[0074] When all the coolant in the -20℃ coolant tank has flowed out, close the solenoid valve and water pump on the outlet pipe of the -20℃ coolant tank, and open the solenoid valve on the compressed air supply assembly. The clean compressed air supplied by the compressed air supply assembly passes sequentially through the solenoid valve on the compressed air supply assembly, the fuel cell engine, the solenoid valve on the recovery tank, and the solenoid valve on the inlet pipe of the -10℃ coolant tank, purging the approximately -20℃ coolant in the fuel cell engine and pipeline into the -10℃ coolant tank.

[0075] After continuously purging the fuel cell engine and pipelines as needed or at specified intervals, close the solenoid valve on the compressed air supply assembly to complete the second coolant replacement of the engine.

[0076] Next, the solenoid valves on the inlet pipe of the -20℃ coolant tank, the solenoid valves on the outlet pipe of the -30℃ coolant tank, and the water pump are opened. The approximately -30℃ coolant in the -30℃ coolant tank flows sequentially through the solenoid valve on the outlet pipe of the -30℃ coolant tank, the water pump, the fuel cell engine, and the solenoid valve on the inlet pipe of the -20℃ coolant tank, before flowing into the -20℃ coolant tank.

[0077] When all the coolant in the -30℃ coolant tank has flowed out, close the solenoid valve and water pump on the outlet pipe of the -30℃ coolant tank, and open the solenoid valve on the compressed air supply component. The clean compressed air provided by the compressed air supply component passes sequentially through the solenoid valve on the compressed air supply component, the fuel cell engine, the solenoid valve on the recovery tank, and the solenoid valve on the inlet pipe of the -20℃ coolant tank, purging the approximately -30℃ coolant in the fuel cell engine and pipeline into the -20℃ coolant tank.

[0078] After continuously purging the fuel cell engine and pipelines as needed or at specified intervals, close the solenoid valve on the compressed air supply component to complete the engine's third coolant replacement.

[0079] Next, open the solenoid valve on the inlet pipe of the -30℃ coolant tank, the solenoid valve on the outlet pipe of the -40℃ coolant tank, and the water pump. The approximately -40℃ coolant in the -40℃ coolant tank flows sequentially through the solenoid valve on the outlet pipe of the -40℃ coolant tank, the water pump, the fuel cell engine, and the solenoid valve on the inlet pipe of the -30℃ coolant tank, before flowing into the -30℃ coolant tank.

[0080] When all the coolant in the -40℃ coolant tank has flowed out, close the solenoid valve and water pump on the outlet pipe of the -40℃ coolant tank, and open the solenoid valve on the compressed air supply assembly. The clean compressed air supplied by the compressed air supply assembly passes sequentially through the solenoid valve on the compressed air supply assembly, the fuel cell engine, the solenoid valve on the recovery tank, and the solenoid valve on the inlet pipe of the -30℃ coolant tank, purging the approximately -40℃ coolant in the fuel cell engine and pipeline into the -30℃ coolant tank.

[0081] After continuously purging the fuel cell engine and pipelines as needed or at specified intervals, close the solenoid valve on the compressed air supply component to complete the fourth coolant replacement of the engine.

[0082] Finally, open the solenoid valve on the inlet pipe of the -40℃ coolant tank, the solenoid valve on the outlet pipe of the -45℃ coolant tank, and the water pump. The approximately -45℃ standard coolant in the -45℃ coolant tank flows sequentially through the solenoid valve on the outlet pipe of the -45℃ coolant tank, the water pump, the fuel cell engine, and the solenoid valve on the inlet pipe of the -40℃ coolant tank, before flowing into the -40℃ coolant tank.

[0083] When all the coolant in the -45℃ coolant tank has flowed out, close the solenoid valve and water pump on the outlet pipe of the -45℃ coolant tank, and open the solenoid valve on the compressed air supply assembly. The clean compressed air supplied by the compressed air supply assembly passes sequentially through the solenoid valve on the compressed air supply assembly, the fuel cell engine, the solenoid valve on the recovery tank, and the solenoid valve on the inlet pipe of the -40℃ coolant tank, purging the coolant below -40℃ in the fuel cell engine and pipeline into the -40℃ coolant tank.

[0084] After continuously purging the fuel cell engine and pipelines as needed or at specified intervals, close the solenoid valve on the compressed air supply assembly to complete the fifth coolant replacement of the engine.

[0085] After five coolant replacements, the residual coolant in the fuel cell engine has a freezing point of less than -40°C, which meets the factory requirements.

[0086] After the coolant replacement of this fuel cell engine is completed, new -45℃ coolant is added to the -45℃ standard coolant tank to perform the coolant replacement for the next fuel cell engine.

[0087] After a certain number of fuel cell engines are replaced, the high-freezing-point coolant in the recovery tank is professionally recycled once a certain amount is reached.

[0088] For first-time use, coolant with the corresponding freezing point value can be added to the -10℃, -20℃, -30℃, -40℃, and -45℃ standard coolant tanks.

[0089] A fuel cell engine is a fuel cell engine that has passed the test using deionized water.

[0090] Example 5

[0091] To further investigate the implementation of the coolant replacement method, in conjunction with Examples 2 and 3, and Figure 3 As shown, this embodiment provides an application of a coolant replacement device on multiple fuel cell engines, including multiple fuel cell engines 8. The coolant replacement branch 2 includes multiple sets, which are connected in series. Each coolant replacement branch 2 is equipped with two sets of solenoid valves 4. The multiple fuel cell engines 8 are respectively arranged between the two sets of solenoid valves 4. The standard coolant tank 5, water pump 6, compressed air supply component 7, multiple sets of coolant replacement branches 2 and recovery tank 1 are connected in sequence.

[0092] The coolant replacement branch 2 provided in this embodiment includes a workstation, and the fuel cell engine 8 is installed at the workstation via a quick-connect device.

[0093] The factory-set requirement for the fuel cell engine in this embodiment is that the freezing point of the coolant is no greater than -40°C, and the freezing point of the standard coolant is set to -45°C, that is, the coolant in the standard coolant tank is at -45°C. The fuel cell engine in this embodiment includes n groups, and all n groups of fuel cell engines are set at the workstation.

[0094] In this embodiment, the coolant of the nth group of fuel cell engines is replaced through the following steps, so that the nth group of fuel cell engines meets the factory requirements.

[0095] First, open the solenoid valves on all coolant replacement branches, and simultaneously open the solenoid valve on the compressed air supply assembly. This allows the clean compressed air supplied by the compressed air supply assembly to pass sequentially through the solenoid valve on the compressed air supply assembly and all coolant replacement branches, purging the residual liquid on the fuel cell engine in group n to the fuel cell engine in group n-1, and so on, until it is purged to the fuel cell engine in group 1 and then into the recovery liquid tank.

[0096] After purging as needed or for a specified period of time, close the solenoid valve on the compressed air supply component to complete the first residual liquid purging of the fuel cell engine.

[0097] Next, turn on the water pump to allow the -45°C coolant in the standard coolant tank to pass through the water pump and all coolant replacement branches in sequence until it flows into the recovery tank.

[0098] When the -45°C coolant in the standard coolant tank passes through the nth group of fuel cell engines, the coolant undergoes coolant replacement. The freezing point of the coolant increases after replacement. This process continues, and the freezing point of the coolant increases multiple times after passing through multiple groups of fuel cell engines. Finally, the coolant flows into the recovery tank.

[0099] After continuous replacement as needed or for a specified period, the water pump is turned off to complete the coolant replacement. The residual coolant freezing point value in the nth group of fuel cell engines after coolant replacement is less than -40℃, meeting the factory requirements. Then, the solenoid valve on the compressed air supply component is opened to purge multiple coolant replacement branches again, purging the residual coolant into the recovery tank. After a certain period of time, the solenoid valve on the compressed air supply component is closed to complete the purging.

[0100] Finally, close the solenoid valves on all coolant replacement branches, remove the nth group of fuel cell engines that have passed coolant replacement, and sequentially move the (n-1)th group of fuel cell engines forward one workstation until the first group of fuel cell engines is moved to the second workstation. Add a new fuel cell engine to the first workstation, and then begin coolant replacement for the (n-1)th group of fuel cell engines to meet factory requirements. Remove the n-1th group of fuel cell engines that have passed coolant replacement, and move the fuel cell engines from each workstation forward one workstation again to begin coolant replacement for the (n-2)th group of fuel cells. Repeat this operation to keep the system running continuously, constantly removing fuel cell engines that have passed coolant replacement while continuously adding new fuel cell engines that need coolant replacement, forming a production line operation. Multiple fuel cell engines are replaced simultaneously, shortening the coolant replacement time.

[0101] The -45°C coolant in the standard coolant tank is used for the nth group of fuel cell engines. This is the nth and final coolant replacement for the nth group of fuel cell engines. After the replacement, the nth group of fuel cell engines meets the factory requirements. As shown in Example 2, the coolant temperature increases after the replacement of the coolant in the nth group of fuel cell engines. The increased coolant temperature is used for the (n-1)th coolant replacement of the (n-1)th group of fuel cell engines. The coolant temperature increases again after the replacement, and it is used for the (n-2)th coolant replacement of the (n-2)th group of fuel cell engines. After the (n-2)th coolant replacement of the (n-2)th group of fuel cell engines, the coolant temperature increases again, and it is used for the (n-3)th coolant replacement of the (n-3)th group of fuel cell engines. This process is repeated until the coolant is used for the first coolant replacement of the 1st group of fuel cell engines. The temperature of the coolant during the first coolant replacement of the 1st group of fuel cell engines is not lower than -10°C.

[0102] When using the above device for the first time, the first fuel cell engine is put into operation at station 1, and the other stations 2, ..., n-1, n are connected by tooling that replaces the fuel cell engine.

[0103] This embodiment can be configured with multiple workstations for replacement processing according to actual needs and factory requirements.

[0104] This invention employs this method for coolant replacement in fuel cell engines, which significantly reduces coolant usage, lowers costs, shortens replacement time, and improves replacement efficiency.

[0105] The coolant replacement device provided by this invention is convenient and flexible to use, and is more conducive to implementation on the production line, saving time and cost, while also saving raw material costs.

[0106] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for replacing coolant, characterized in that: Includes the following steps: After the test is completed, the engine is purged of residual water. The engine coolant is replaced multiple times by using coolant with multiple preset freezing point values. Determine whether the coolant inside the engine has reached the factory-set freezing point after replacement; If yes, the engine coolant replacement is complete; if not, continue the coolant replacement process until the coolant inside the engine reaches the factory-set freezing point.

2. The coolant replacement method according to claim 1, characterized in that: The preset freezing point value of the coolant is not greater than the freezing point value of the standard coolant.

3. The coolant replacement method according to claim 1, characterized in that: The coolant is replaced no less than 5 times, and the engine and pipelines are purged after each coolant replacement.

4. The coolant replacement method according to claim 1, characterized in that: The coolant replacement is performed for the final replacement using coolant with a standard freezing point value.

5. A coolant replacement device, implementing the coolant replacement method according to any one of claims 1-4, characterized in that: It includes a coolant replacement branch, a standard coolant tank, a compressed air supply assembly, and a recovery tank, wherein the recovery tank, the coolant replacement branch, the standard coolant tank, and the compressed air supply assembly are connected in sequence.

6. A coolant replacement device according to claim 5, characterized in that: The recovery liquid tank, the standard coolant tank, and the compressed air supply assembly are all equipped with solenoid valves.

7. A coolant replacement device according to claim 5, characterized in that: It also includes a water pump, which is installed on the pipeline between the standard coolant tank and the compressed air supply assembly.

8. The application of the coolant replacement device according to any one of claims 5-7 in a fuel cell engine, characterized in that: The coolant displacement branch includes multiple sets, which are connected in parallel. The fuel cell engine is connected in parallel with the multiple sets of coolant displacement branches. The standard coolant tank, the compressed air supply component, and the fuel cell engine are connected in sequence.

9. The application of the coolant replacement device according to claim 8 in a fuel cell engine, characterized in that: Each coolant replacement branch is equipped with a coolant tank and a solenoid valve. Each solenoid valve consists of two sets, which are respectively installed on the inlet and outlet pipes of the coolant tank.

10. The application of the coolant replacement device according to any one of claims 5-7 in multiple fuel cell engines, comprising multiple fuel cell engines, characterized in that: The coolant replacement branch includes multiple sets, which are connected in series. Each coolant replacement branch is equipped with two sets of solenoid valves, and multiple fuel cell engines are respectively installed between the two sets of solenoid valves.

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