Fuel cell system based on variable working conditions

Abstract

The utility model relates to a fuel cell system based on variable working conditions, which comprises a fuel cell stack provided with a first end and a second end; the air compressor is provided with an air compression end and a turbine end, the air compression end is connected to the first end, the turbine end is connected to the second end, a first switch piece is arranged between the air compression end and the first end, a second switch piece is arranged between the turbine end and the second end, and a third switch piece is arranged between a pipeline connected with the air compression end and a pipeline connected with the turbine end; wherein when the fuel cell stack is initially started or runs, the third switch piece is closed, and the first switch piece and the second switch piece are opened; and when the fuel cell stack is shut down, the third switch piece is opened, and the first switch piece and the second switch piece are closed. According to the fuel cell system based on the variable working conditions, an extremely high response rate is needed in the case of rapid load pulling; and a recovery system with a turbine needs to be shut down and purged more sufficiently.

Description

Technical Field

[0001] This utility model relates to the field of fuel cell technology, and in particular to a fuel cell system based on varying operating conditions. Background Technology

[0002] Fuel cell power generation is an energy conversion device that directly converts the chemical energy of the supplied fuel into electrical energy. It is a power generation device that can continuously obtain electricity by continuously supplying fuel. Due to its advantages such as high power generation efficiency and good environmental characteristics, it has been actively developed in recent years.

[0003] When fuel cell systems are used in vehicle systems, they will face complex and variable operating conditions, such as rapid load increases and abnormal shutdowns. For fuel cells, which are electrical energy devices that generate electricity through chemical reactions, their reaction speed is relatively mild, requiring coordination with other system components to achieve a response to these changing conditions. Utility Model Content

[0004] Therefore, the technical problem to be solved by this utility model is to overcome the problems of slow load response speed of fuel cell systems and incomplete shutdown purging of turbine recovery systems in the prior art.

[0005] To address the aforementioned technical problems, this utility model provides a fuel cell system based on varying operating conditions, comprising: a fuel cell stack with a first end and a second end; an air compressor with a compressor end and a turbine end, the compressor end being connected to the first end, the turbine end being connected to the second end, a first switch being provided between the compressor end and the first end, a second switch being provided between the turbine end and the second end, and a third switch being provided between the pipes connected to the compressor end and the turbine end; wherein, when the fuel cell stack is initially started or running, the third switch is closed, and the first and second switches are open; when the fuel cell stack is shut down, the third switch is open, and the first and second switches are closed. The fuel cell system based on varying operating conditions described in this utility model requires an extremely fast response rate under rapid load; and the shutdown purging with the turbine recovery system needs to be more thorough.

[0006] In one embodiment of this utility model, the first switching element is a throttle valve.

[0007] In one embodiment of this utility model, the second switching element is a back pressure valve.

[0008] In one embodiment of this utility model, the third switching element is a bypass valve.

[0009] In one embodiment of this utility model, the first end is the inlet end of the fuel cell stack, and the second end is the outlet end of the fuel cell stack.

[0010] In one embodiment of this utility model, an intercooler is provided between the compressor end and the first end, a first pipe is provided between the compressor end and the intercooler, a second pipe is provided between the intercooler and the first end, and the first switch is disposed on the second pipe.

[0011] In one embodiment of the present invention, a third pipe is provided between the turbine end and the second end, the second switch is disposed on the third pipe, and a fourth pipe is provided between the second pipe and the third pipe, the third switch being disposed on the fourth pipe.

[0012] In one embodiment of the present invention, one end of the fourth pipe is connected to the second pipe between the second switch and the intercooler, and the other end of the fourth pipe is connected to the third pipe between the third switch and the turbine end.

[0013] In one embodiment of this utility model, the compressed air end is connected to a chemical filter.

[0014] In one embodiment of this utility model, a muffler is connected to the turbine end.

[0015] Compared with the prior art, the above-mentioned technical solution of this utility model has the following beneficial effects:

[0016] The air compressor system is started in advance. Once the air compressor reaches the specified speed, the air supply is switched to the main circuit to quickly establish the hydrogen-air reaction interface and increase the load-bearing rate.

[0017] At the outlet of the fuel cell system, the air compressor turbine end is subjected to the impact of high humidity and heat gas, and water vapor will remain inside. After the system is shut down, the air compressor turbine end is purged separately through a bypass branch to prevent the purging gas from entering the fuel cell stack and drying out its internal proton exchange membrane. Attached Figure Description

[0018] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the structure of the fuel cell system under varying operating conditions during startup or shutdown in a preferred embodiment of this utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the fuel cell system under varying operating conditions in a preferred embodiment of the present invention.

[0021] Explanation of reference numerals in the accompanying drawings: 1. Fuel cell stack; 2. Air compressor; 21. Compressor end; 22. Turbine end; 23. Chemical filter; 24. Silencer; 3. First switch; 4. Second switch; 5. Third switch; 6. Intercooler; 61. First pipe; 62. Second pipe; 63. Third pipe; 64. Fourth pipe. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0023] Reference Figure 1 , 2 As shown, the fuel cell system based on variable operating conditions of this utility model includes: a fuel cell stack 1, which is provided with a first end and a second end, the first end being the inlet end of the fuel cell stack 1 and the second end being the outlet end of the fuel cell stack 1; an air compressor 2, which is provided with a compressor end 21 and a turbine end 22, the compressor end 21 being connected to the first end and the turbine end 22 being connected to the second end, a first switch 3 being provided between the compressor end 21 and the first end, a second switch 4 being provided between the turbine end 22 and the second end, and a third switch 5 being provided between the pipe connected to the compressor end 21 and the pipe connected to the turbine end 22; wherein, when the fuel cell stack 1 is initially started or running, the third switch 5 is closed and the first switch 3 and the second switch 4 are open; when the fuel cell stack 1 is stopped, the third switch 5 is open and the first switch 3 and the second switch 4 are closed.

[0024] In the above structure, the first switching element 3 is a throttle valve. The second switching element 4 is a back pressure valve. The third switching element 5 is a bypass valve. Adding a bypass valve to the air branch not only increases the load-bearing rate but also facilitates purging of the air compressor turbine end after system shutdown, improving component utilization.

[0025] A bypass branch is added to the main air circuit of fuel cell stack 1. When fuel cell stack 1 starts to load, the air compressor is run in advance and the gas is discharged through the bypass branch. Once the air compressor supply conditions can meet the load power requirements, the main air circuit is switched to run to quickly establish the hydrogen-air interface and quickly load the system.

[0026] In high-power systems with turbine regeneration, the air discharged from the fuel cell stack is hot and humid gas. After the system is shut down, a new round of purging is performed on the air compressor turbine end through a bypass to prevent water from remaining on the air compressor turbine end and to avoid drying out the proton exchange membrane inside the fuel cell stack.

[0027] In the above structure, an intercooler 6 is provided between the compressor end 21 and the first end, a first pipe 61 is provided between the compressor end 21 and the intercooler 6, and a second pipe 62 is provided between the intercooler 6 and the first end. The first switch 3 is disposed on the second pipe 62. A third pipe 63 is provided between the turbine end 22 and the second end, and the second switch 4 is disposed on the third pipe 63. A fourth pipe 64 is provided between the second pipe 62 and the third pipe 63, and a third switch 5 is disposed on the fourth pipe 64. One end of the fourth pipe 64 is connected to the second pipe 62 between the second switch 4 and the intercooler 6, and the other end of the fourth pipe 64 is connected to the third pipe 63 between the third switch 5 and the turbine end 22.

[0028] Additionally, a chemical filter 23 is connected to the compressor end 21. A muffler 24 is connected to the turbine end 22.

[0029] The present invention relates to a fuel cell system based on varying operating conditions. By adding a bypass valve to the main air line, the flow of the pipeline at the front end of the fuel cell stack is diverted, which enables more flexible control of the air intake conditions at the front end of the fuel cell stack.

[0030] ① When the fuel cell system is initially started up and the system power load command is executed, the bypass valve is opened, the throttle valve and the back pressure valve are closed, the air compressor is quickly run to the speed required for the target power, the bypass valve is closed, the throttle valve and the back pressure valve are opened, the air compressor gas is introduced into the fuel cell stack for reaction, the hydrogen-air interface is quickly established, and the fuel cell stack load rate is increased.

[0031] ② When the fuel cell power generation system is running stably, close the bypass valve and open the throttle valve and back pressure valve.

[0032] ③ When the fuel cell power generation system is shut down for purging, after the air compressor has completed purging the inside of the stack casing, close the throttle valve and back pressure valve, and open the bypass valve. This performs a secondary, thorough purging of the air compressor turbine end to prevent liquid residue from remaining. By directly introducing gas into the air compressor turbine end through the bypass valve, the secondary purging avoids over-drying the proton exchange membrane of the stack, which would affect its performance. At the same time, directly purging the turbine end with purging gas reduces energy loss of gas entering the stack.

[0033] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A fuel cell system based on a variable operating condition, characterized by, The utility model relates to a fuel cell system, comprising: a fuel cell stack, which is provided with a first end and a second end; an air compressor, which is provided with a compression end and a turbine end, the compression end is connected to the first end, the turbine end is connected to the second end, a first switch is arranged between the compression end and the first end, a second switch is arranged between the turbine end and the second end, and a third switch is arranged between the pipeline connected to the compression end and the pipeline connected to the turbine end; wherein, when the fuel cell stack is initially operated, the third switch is closed, and the first switch and the second switch are opened; when the fuel cell stack is started or stopped, the third switch is opened, and the first switch and the second switch are closed.

2. The fuel cell system based on multiple variable operating conditions according to claim 1, characterized in that: The first switch is a throttle valve.

3. The fuel cell system based on multiple variable operating conditions according to claim 2, characterized in that: The second switch is a back pressure valve.

4. The fuel cell system based on multiple variable operating conditions according to claim 3, characterized in that: The third switch is a bypass valve.

5. The multi-operating condition based fuel cell system of claim 4, wherein: The first end is the inlet end of the fuel cell stack, and the second end is the outlet end of the fuel cell stack.

6. The multi-operating condition based fuel cell system of claim 5, wherein: A intercooler is arranged between the compression end and the first end, a first pipeline is arranged between the compression end and the intercooler, a second pipeline is arranged between the intercooler and the first end, and the first switch is arranged on the second pipeline.

7. The multi-operating condition based fuel cell system of claim 6, wherein: A third pipeline is arranged between the turbine end and the second end, the second switch is arranged on the third pipeline, a fourth pipeline is arranged between the second pipeline and the third pipeline, and the third switch is arranged on the fourth pipeline.

8. The multi-operating condition based fuel cell system of claim 7, wherein: One end of the fourth pipeline is connected to the second pipeline between the second switch and the intercooler, and the other end of the fourth pipeline is connected to the third pipeline between the third switch and the turbine end.

9. The multi-operating condition based fuel cell system of claim 1 or 8, wherein: The compression end is connected to a chemical filter.

10. The multi-operating condition based fuel cell system of claim 9, wherein: The turbine end is connected to a silencer.

Images