A multi-stack fuel cell system coolant filling method and system and vehicle

Abstract

The present invention discloses a method for filling coolant in a multi-stack fuel cell system, a system therefor, and a vehicle therefor, relating to the technical field of fuel cell systems. A multi-stack fuel cell system includes an expansion water tank, a first valve, a second valve, at least one fuel cell, a third valve, a fourth valve, and a heater connected in sequence. A main water pump is provided between the expansion water tank and the heater, and the above-mentioned sequentially connected components form a closed loop. A method for filling coolant in a multi-stack fuel cell system controls the connection or connection relationship between the water supply valve, the vacuum equipment, the second valve, the auxiliary water tank, the third valve, the auxiliary water pump, and the fourth valve, so that the fuel cell system automatically completes the water addition and exhaust operations and completes the coolant filling. Compared with the prior art, the method for filling coolant in a multi-stack fuel cell system in the present application can realize automatic coolant replenishment, avoid too little coolant in the cooling circuit of the fuel cell system, and reduce the intensity of daily manual maintenance work.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell systems, and in particular to a method for filling coolant in a multi-stack fuel cell system, a system thereof, and a vehicle. Background Art

[0002] During the operation of the fuel cell, in order to maintain the high efficiency and stability of the stack, thermal management is very important for the fuel cell system, whether it is system cooling during high-power operation or system heating during cold start. To this end, the fuel cell system will use coolant circulation to cool and control the temperature of the fuel cell system.

[0003] However, as the use time accumulates, the coolant in the cooling circuit of the fuel cell system will gradually decrease. In addition, there will also be the problem of coolant leakage. Once the coolant leaks after the fuel cell has been used for a long time, it is necessary to investigate the cause of the leak and replenish the coolant to the specified amount in time. The added coolant needs to ensure certain system conductivity requirements and control the concentration of related conductive ions in the cooling water circuit to be within a reasonable range, while also ensuring that the fuel cell system can have high system operating efficiency and long-life durability. During the process of adding coolant, the air in the water field gathers on the upper part of the stack and is difficult to discharge, resulting in a very slow filling process and even requiring human intervention to vent. In addition, in the prior art, the expansion water tank is generally arranged on the roof of the vehicle. When adding coolant, it is necessary to climb onto the roof to operate, which is time-consuming and labor-intensive and also very unsafe. Therefore, there is currently no good method for controlling the coolant filling of the coolant circuit. The present application proposes a method for filling coolant in a multi-stack fuel cell system and its system and vehicle. Summary of the Invention

[0004] In view of the defects existing in the prior art, the purpose of the present invention is to provide a multi-stack fuel cell system coolant filling method and its system and vehicle, aiming to solve the technical problems in the related art to a certain extent.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A method for filling coolant in a multi-stack fuel cell system comprises the following steps:

[0007] Step 1: Start the coolant filling operation, close the water supply valve, control the first valve to connect the vacuum equipment with the second valve, control the second valve to connect the auxiliary water tank with the first valve, and control the third valve to connect the auxiliary water pump with the fourth valve; start the vacuum equipment, record the expansion tank pressure P at this time, record the initial value as P0, and proceed to the next step;

[0008] Step 2: operate the vacuum pumping device for a time t until the pressure P in the expansion tank gradually decreases to P1, then control the vacuum pumping device to stop the vacuum pumping operation and proceed to the next step;

[0009] Step 3: Open the water supply valve, the system starts to automatically replenish water, and increases the pressure P in the expansion tank to make P = P0 ± Pn, where Pn is the pressure compensation constant. This means that the system is completed except for the stack water supply. Record the auxiliary water tank level V0 and proceed to the next step.

[0010] Step 4: Control the second valve to connect the fuel cell stack to the auxiliary water tank, control the third valve to connect the auxiliary water pump to the fuel cell stack, start the auxiliary water pump to replenish water to the fuel cell stack, and detect the liquid level of the auxiliary water tank at V. Calculate the difference between the volume when the auxiliary water tank level is V0 and the total volume of the fuel cell stack cooling path Vd as V1. Ensure that the volume when the auxiliary water tank level is V is no greater than V1, indicating that the fuel cell stack has been exhausted and proceed to the next step.

[0011] Step 5. Close the auxiliary water pump, control the third valve to connect the fuel cell stack to the fourth valve, control the second valve to connect the first valve to the fuel cell stack, control the first valve to connect the expansion tank to the second valve and the main water pump, then open the water supply valve. The system automatically completes the water adding and exhausting operations and completes the coolant filling.

[0012] On the basis of the above technical solution, in step 4, the total volume Vd of the stack cooling path is pre-set as a parameter value according to the size and model of the stack.

[0013] Based on the above technical solution, a multi-stack fuel cell system includes an expansion water tank, a first valve, a second valve, at least one fuel cell, a third valve, a fourth valve and a heater connected in sequence. A main water pump is provided between the expansion water tank and the heater, and the above-mentioned components connected in sequence form a closed loop. A water supply valve is also provided between the expansion water tank and the main water pump. The first valve is also connected to a vacuum pump. An auxiliary water tank is provided in parallel with the fuel cell. An auxiliary water pump is connected in series to the auxiliary water tank. The auxiliary water pump is connected to the third valve through a pipeline. A radiator is connected in parallel to the heater. The two ends of the radiator are respectively connected to the fourth valve and the main water pump. In addition, a liquid level sensor is provided in the auxiliary water tank.

[0014] Based on the above technical solution, the expansion water tank is provided with a liquid level sensor.

[0015] On the basis of the above technical solution, the first valve, the second valve, the third valve and the fourth valve are three-way valves.

[0016] Based on the above technical solution, a fuel cell system vehicle includes at least one multi-stack fuel cell system and one or more processors to execute any of the methods described above.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] (1) Compared with the prior art, the method for filling coolant in a multi-stack fuel cell system of the present invention can realize automatic coolant replenishment, automatic drainage and exhaust, automatic filling, and automatic correction and fine-tuning, thereby avoiding insufficient coolant in the cooling circuit of the fuel cell system and reducing the intensity of daily manual maintenance work.

[0019] (2) The multi-stack fuel cell system coolant filling system of the present invention can simultaneously fill coolant into multiple single-stack or multi-stack fuel cells and systems, and realize smooth and efficient cooling pipe filling operation through vacuum pumping and auxiliary auxiliary water tanks. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a logic flow diagram of a method for adding coolant to a multi-stack fuel cell system according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic structural diagram of a coolant filling system for a multi-stack fuel cell system in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0023] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0024] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set", "install", "connect", and "connect" 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 or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. Moreover, the terms "include", "comprise", or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article, or device. In the absence of further restrictions, the elements defined by the sentence "including a..." do not exclude the presence of other identical elements in the process, method, article, or device that includes the elements.

[0025] See also Figure 1 This is a logic flow chart of a method for adding coolant to a multi-stack fuel cell system according to an embodiment of the present invention, which includes the following steps:

[0026] Step 1: Start the coolant filling operation, close the water supply valve, control the first valve to connect the vacuum equipment with the second valve, control the second valve to connect the auxiliary water tank with the first valve, and control the third valve to connect the auxiliary water pump with the fourth valve; start the vacuum equipment, record the expansion tank pressure P at this time, record the initial value as P0, and proceed to the next step;

[0027] Step 2: operate the vacuum pumping device for a time t until the pressure P in the expansion tank gradually decreases to P1, then control the vacuum pumping device to stop the vacuum pumping operation and proceed to the next step;

[0028] Step 3: Open the water supply valve, the system starts to automatically replenish water, and increases the pressure P in the expansion tank to make P = P0 ± Pn, where Pn is the pressure compensation constant. This means that the system is completed except for the stack water supply. Record the auxiliary water tank level V0 and proceed to the next step.

[0029] Step 4: Control the second valve to connect the fuel cell stack to the auxiliary water tank, control the third valve to connect the auxiliary water pump to the fuel cell stack, start the auxiliary water pump to replenish water to the fuel cell stack, and detect the liquid level of the auxiliary water tank at V. Calculate the difference between the volume when the auxiliary water tank level is V0 and the total volume of the fuel cell stack cooling path Vd as V1. Ensure that the volume when the auxiliary water tank level is V is no greater than V1, indicating that the fuel cell stack has been exhausted and proceed to the next step.

[0030] Step 5. Close the auxiliary water pump, control the third valve to connect the fuel cell stack to the fourth valve, control the second valve to connect the first valve to the fuel cell stack, control the first valve to connect the expansion tank to the second valve and the main water pump, then open the water supply valve. The system automatically completes the water adding and exhausting operations and completes the coolant filling.

[0031] In this embodiment, the total volume Vd of the stack cooling path in step 4 is pre-set as a parameter value according to the size and model of the stack.

[0032] A multi-stack fuel cell system in the present application is suitable for adopting the above-mentioned multi-stack fuel cell system coolant filling method, including an expansion water tank, a first valve, a second valve, at least one fuel cell, a third valve, a fourth valve and a heater connected in sequence, a main water pump is provided between the expansion water tank and the heater, and the above-mentioned sequentially connected components form a closed loop, wherein a water supply valve is also provided between the expansion water tank and the main water pump, the first valve is also connected to a vacuum pumping device, an auxiliary water tank is provided in parallel with the fuel cell, an auxiliary water tank is connected in series with an auxiliary water pump, the auxiliary water pump is connected to the third valve through a pipeline, a radiator is connected in parallel with the heater, and the two ends of the radiator are respectively connected to the fourth valve and the main water pump. In addition, a liquid level sensor is provided in the auxiliary water tank.

[0033] In this embodiment, the expansion water tank is provided with a liquid level sensor.

[0034] In this embodiment, the first valve, the second valve, the third valve, and the fourth valve are one or a combination of two or a combination of three of a three-way valve, a four-way valve, and a five-way valve.

[0035] This embodiment also involves a fuel cell system vehicle, which specifically includes at least one multi-stack fuel cell system, and one or more processors executing steps one to five in a multi-stack fuel cell system coolant filling method to complete coolant filling.

[0036] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0037] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0038] The present invention is not limited to the above-described embodiments. Persons skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are deemed to be within the scope of protection of the present invention. Any matters not described in detail in this specification constitute prior art known to those skilled in the art.

Claims

1. A method for filling coolant in a multi-stack fuel cell system, characterized in that: The following steps are involved: Step 1: Start the coolant filling operation, close the water supply valve, control the first valve to connect the vacuum equipment with the second valve, control the second valve to connect the auxiliary water tank with the first valve, and control the third valve to connect the auxiliary water pump with the fourth valve; start the vacuum equipment, record the expansion tank pressure P at this time, record the initial value as P0, and proceed to the next step; Step 2: operate the vacuum pumping device for a time t until the pressure P in the expansion tank gradually decreases to P1, then control the vacuum pumping device to stop the vacuum pumping operation and proceed to the next step; Step 3: Open the water supply valve, the system starts to automatically replenish water, and increases the pressure P in the expansion tank to make P = P0 ± Pn, where Pn is the pressure compensation constant. This means that the system is completed except for the stack water supply. Record the auxiliary water tank level V0 and proceed to the next step. Step 4: Control the second valve to connect the fuel cell stack to the auxiliary water tank, control the third valve to connect the auxiliary water pump to the fuel cell stack, start the auxiliary water pump to replenish water to the fuel cell stack, and detect the liquid level of the auxiliary water tank at V. Calculate the difference between the volume when the auxiliary water tank level is V0 and the total volume of the fuel cell stack cooling path Vd as V1. Ensure that the volume when the auxiliary water tank level is V is no greater than V1, indicating that the fuel cell stack has been exhausted and proceed to the next step. Step 5. Close the auxiliary water pump, control the third valve to connect the fuel cell stack to the fourth valve, control the second valve to connect the first valve to the fuel cell stack, control the first valve to connect the expansion tank to the second valve and the main water pump, then open the water supply valve. The system automatically completes the water adding and exhausting operations and completes the coolant filling.

2. The method for filling coolant in a multi-stack fuel cell system according to claim 1, wherein: In step 4, the total volume Vd of the stack cooling path is pre-set as a parameter value according to the size and model of the stack.

3. A method for filling coolant in a multi-stack fuel cell system according to any one of claims 1 to 2, characterized in that: It includes an expansion water tank, a first valve, a second valve, at least one battery stack, a third valve, a fourth valve and a heater connected in sequence. A main water pump is provided between the expansion water tank and the heater, and the above-mentioned components connected in sequence form a closed loop. A water supply valve is also provided between the expansion water tank and the main water pump. The first valve is also connected to a vacuum pump. An auxiliary water tank is provided in parallel with the battery stack. An auxiliary water pump is connected in series to the auxiliary water tank. The auxiliary water pump is connected to the third valve through a pipeline. A radiator is connected in parallel to the heater. The two ends of the radiator are respectively connected to the fourth valve and the main water pump. In addition, a liquid level sensor is provided in the auxiliary water tank.

4. The method for filling coolant in a multi-stack fuel cell system according to claim 3, characterized in that: The expansion water tank is provided with a liquid level sensor.

5. The method for filling coolant in a multi-stack fuel cell system according to claim 3, characterized in that: The first valve, the second valve, the third valve and the fourth valve are three-way valves.

6. A fuel cell system vehicle, characterized in that: The system comprises at least one multi-stack fuel cell system, and one or more processors executing the method according to any one of claims 1 to 2.

Images