Fuel cell tail gas recovery and drainage system and working method thereof

Abstract

The invention relates to a fuel cell tail gas recovery and drainage system and a working method thereof.Gas provided by a gas cylinder sequentially passes through a high-pressure assembly, a first electromagnetic valve and an ultrasonic humidifier and then enters a galvanic pile from an inlet to participate in a reaction, and an outlet of the galvanic pile is connected to an inlet of a water diversion buffer tank through a pipeline; a second electromagnetic valve is arranged on a connecting pipeline between an outlet of the galvanic pile and the water distribution buffer tank, a first outlet of the water distribution buffer tank is connected with an inlet of the galvanic pile through a pipeline, a third electromagnetic valve is arranged on a connecting pipeline between the water distribution buffer tank and the inlet of the galvanic pile, and a pressure sensor is arranged in the water distribution buffer tank; two working modes are formed by arranging the water distribution buffer tank to be matched with the opening degree of the electromagnetic valve, and in the first working mode, the water distribution buffer tank recovers reaction gas and galvanic pile produced water; in the second working mode, the recycled gas stored in the water diversion buffer tank is directly supplied to the galvanic pile for reaction as a gas source; and the cycle is repeated, so that the gas recycling function of the low-power fuel cell is realized.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and in particular to a fuel cell tail gas recovery and drainage system and a working method thereof. Background Art

[0002] Existing fuel cell reaction gas recycling is mainly completed by ejectors or reflux pumps. The ejector uses Bernoulli's principle to form a negative pressure at the nozzle, and reuses the unreacted gas in the stack and discharges the liquid water in the stack according to the pressure difference between the gas replenishment port and the gas reflux port; the reflux pump uses the impeller to create a pressure difference to reuse the unreacted gas in the stack and discharge the liquid water in the stack.

[0003] The ejection process of the ejector requires the front end to provide very high gas pressure and gas flow to form a pressure difference at the nozzle. Therefore, ejection can be achieved in high-power fuel cells, but it is difficult to meet the requirements in low-power fuel cells. For the reflux pump, due to manufacturing process limitations, the reflux pump is large in size and also requires a larger fuel cell to meet the reflux demand, which will also generate greater auxiliary energy consumption.

[0004] In addition, both of the above solutions require the use of a gas-liquid separator separately to discharge the liquid water in the fuel cell stack, which increases the system volume.

[0005] Therefore, it is urgent to design a fuel cell exhaust gas recovery and drainage system and a working method thereof to solve the problems existing in the above-mentioned prior art. Summary of the invention

[0006] In view of this, the present invention provides a fuel cell exhaust gas recovery and drainage system and a working method thereof, the purpose of which is to replace the traditional ejector or reflux pump to achieve the gas recycling function of a low-power fuel cell.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A fuel cell tail gas recovery and drainage system comprises a gas cylinder, a high-pressure component, a first solenoid valve, an ultrasonic humidifier, a second solenoid valve, a water-dividing buffer tank, a third solenoid valve and a pressure sensor; the gas provided by the gas cylinder passes through the high-pressure component, the first solenoid valve and the ultrasonic humidifier in sequence, and then enters the fuel cell stack through the inlet of the fuel cell stack to participate in the reaction, the outlet of the fuel cell stack is connected to the inlet of the water-dividing buffer tank via a pipeline, and a second solenoid valve is arranged on the connecting pipeline between the outlet of the fuel cell stack and the water-dividing buffer tank, the first outlet of the water-dividing buffer tank is connected to the inlet of the fuel cell stack via a pipeline, and a third solenoid valve is arranged on the connecting pipeline between the water-dividing buffer tank and the inlet of the fuel cell stack, and a pressure sensor is arranged in the water-dividing buffer tank for monitoring the pressure in the water-dividing buffer tank.

[0009] Furthermore, the second outlet of the water separation buffer tank is connected to the ultrasonic humidifier via a pipeline, a one-way valve is provided on the connecting pipeline between the water separation buffer tank and the ultrasonic humidifier, and the liquid water separated by the water separation buffer tank is used to replenish water for the ultrasonic humidifier.

[0010] Furthermore, a drainage pipe is provided at the third outlet of the water-dividing buffer tank for discharging excess water in the water-dividing buffer tank out of the system, and a fourth solenoid valve is provided on the drainage pipe for controlling whether the water in the water-dividing buffer tank is discharged.

[0011] The present invention also provides a working method based on the above-mentioned fuel cell tail gas recovery and drainage system, and the working method is as follows:

[0012] The fuel cell tail gas recovery and drainage system has two working modes. When the system is in operation, the first working mode is started first. When the pressure sensor detects that the pressure in the water separation buffer tank rises to the same level as the pressure at the rear end of the high-pressure assembly, the system switches to the second working mode. When the pressure in the water separation buffer tank drops by 30 kPa, the system returns to the first working mode, and the cycle repeats.

[0013] The first working mode is specifically as follows: the third solenoid valve is closed, the first solenoid valve and the second solenoid valve are opened, and the gas provided by the gas cylinder passes through the high-pressure component, the first solenoid valve, and the ultrasonic humidifier in sequence, and then enters the fuel cell stack from the inlet to participate in the reaction; in the first working mode, the water separation buffer tank is in a low-pressure state. Under the action of the pressure difference, the tail gas generated in the fuel cell stack enters the water separation buffer tank after passing through the second solenoid valve. With the continuous entry of the tail gas, the pressure in the water separation buffer tank gradually increases, and the liquid water in the tail gas is separated in the water separation buffer tank and stored at the bottom of the water separation buffer tank;

[0014] The second working mode is specifically as follows: close the first solenoid valve and the second solenoid valve, open the third solenoid valve, the gas in the water separation buffer tank flows out from the first outlet, passes through the third solenoid valve, and enters the fuel cell stack from the inlet to participate in the reaction. As the gas in the water separation buffer tank is continuously consumed, the pressure in the water separation buffer tank gradually decreases.

[0015] Furthermore, the liquid water stored in the water-dividing buffer tank flows out through the second outlet of the water-dividing buffer tank, passes through the one-way valve and enters the ultrasonic humidifier to atomize and humidify the gas entering the fuel cell stack.

[0016] Furthermore, the volume V of the water diversion buffer tank is calculated as follows:

[0017] The water storage ratio of the water distribution buffer tank is set to 30%. When the liquid water in the water distribution buffer tank exceeds 30%, the fourth solenoid valve is opened to discharge part of the liquid water. When the liquid water storage ratio in the water distribution buffer tank is 30%, the volume V of the water distribution buffer tank is calculated. The specific calculation is as follows:

[0018] V=V g / (1-30%) (1);

[0019] Where V g It is the effective gas volume of the water distribution buffer tank.

[0020] Furthermore, the effective gas volume V of the water separation buffer tank g The specific calculation is as follows:

[0021] V g =m*R g *T / ΔP (2);

[0022] Where m is the fluctuation value of the gas mass in the water separation buffer tank when the two working modes are switched; R g is the molar gas constant of the reaction gas; T is the operating temperature of the fuel cell stack; ΔP is the fluctuation value of the gas pressure in the water separation buffer tank when the two working modes are switched, ΔP = 30 kPa.

[0023] Furthermore, the fluctuation value m of the gas mass in the water-dividing buffer tank when the two working modes are switched is calculated by the following formula:

[0024] m=t*m max (3);

[0025] Where, t is the duration of the second working mode, t = 2min; m max is the maximum gas consumption rate of the fuel cell stack.

[0026] Furthermore, the maximum gas consumption rate of the stack m max Calculated by the following formula:

[0027] m max =I*M*k / z / F (4);

[0028] Wherein, I is the rated operating current of the stack; M is the molar mass of the reaction gas. When the system is used in a hydrogen supply system, the reaction gas is hydrogen, and the value of M is 2. When the system is used in a supply system using pure oxygen, the reaction gas is oxygen, and the value of M is 32. k is the number of cells in the stack; z is the number of reaction charge transfers. When the system is used in a hydrogen supply system, the reaction gas is hydrogen, and the value of z is 2. When the system is used in a supply system using pure oxygen, the reaction gas is oxygen, and the value of z is 4. F is the Faraday constant.

[0029] Furthermore, the molar gas constant R of the reaction gas g Calculated by the following formula:

[0030] R g =R / M (5);

[0031] Where R is the molar gas constant, R = 8.314 J / (mol·K); M is the molar mass of the reaction gas. When the system is used in a hydrogen supply system, the reaction gas is hydrogen, and the value of M is 2. When the system is used in a supply system using pure oxygen, the reaction gas is oxygen, and the value of M is 32.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) Two working modes are formed by setting a water-dividing buffer tank and coordinating the opening of the solenoid valve. In the first working mode, the water-dividing buffer tank recovers the reaction gas and the water produced by the fuel cell stack; in the second working mode, the recovered gas stored in the water-dividing buffer tank is directly supplied to the fuel cell stack reaction as a gas source; this cycle is repeated to realize the gas recycling function of the low-power fuel cell.

[0034] (2) By setting up a water separation buffer tank, the gas reflux structure and the water separation structure are combined, and by connecting the water separation buffer tank with the ultrasonic humidifier, the reflux structure, the water separation structure and the humidification structure are highly integrated, replacing the traditional membrane humidifier, avoiding the high cost and short life of the traditional membrane humidifier, and also reducing the product cost and system complexity.

[0035] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A schematic structural diagram of a fuel cell tail gas recovery and drainage system according to an embodiment of the present invention is shown.

[0038] In the figure: 1. Gas cylinder; 2. High-voltage component; 3. First solenoid valve; 4. Ultrasonic humidifier; 5. Third solenoid valve; 6. Pressure sensor; 7. Second solenoid valve; 8. One-way valve; 9. Water distribution buffer tank; 10. Fourth solenoid valve; 11. Fuel stack. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The embodiment of the present invention provides a fuel cell tail gas recovery and drainage system, as shown in the attached Figure 1 As shown, it includes a gas cylinder 1, a high-pressure component 2, a first solenoid valve 3, an ultrasonic humidifier 4, a second solenoid valve 7, a water-dividing buffer tank 9, a third solenoid valve 5, and a pressure sensor 6; the gas provided by the gas cylinder 1 passes through the high-pressure component 2, the first solenoid valve 3, and the ultrasonic humidifier 4 in sequence, and then enters the battery stack 11 from the inlet of the battery stack 11 to participate in the reaction, the outlet of the battery stack 11 is connected to the inlet of the water-dividing buffer tank 9 through a pipeline, and a second solenoid valve 7 is arranged on the connecting pipeline between the outlet of the battery stack 11 and the water-dividing buffer tank 9, the first outlet of the water-dividing buffer tank 9 is connected to the inlet of the battery stack 11 through a pipeline, and a third solenoid valve 5 is arranged on the connecting pipeline between the water-dividing buffer tank 9 and the inlet of the battery stack 11, and a pressure sensor 6 is arranged in the water-dividing buffer tank 9 for monitoring the pressure in the water-dividing buffer tank 9.

[0041] The second outlet of the water separation buffer tank 9 is connected to the ultrasonic humidifier 4 via a pipeline. A one-way valve 8 is provided on the connecting pipeline between the water separation buffer tank 9 and the ultrasonic humidifier 4. The liquid water separated by the water separation buffer tank 9 is used to replenish water for the ultrasonic humidifier 4.

[0042] The third outlet of the water-dividing buffer tank 9 is provided with a drainage pipe for discharging excess water in the water-dividing buffer tank 9 out of the system. The drainage pipe is provided with a fourth solenoid valve 10 for controlling whether the water in the water-dividing buffer tank 9 is discharged.

[0043] The fuel cell tail gas recovery and drainage system is used in a hydrogen supply system or in a supply system using pure oxygen.

[0044] The embodiment of the present invention further proposes a working method based on the above-mentioned fuel cell tail gas recovery and drainage system, and the working method is as follows:

[0045] The fuel cell tail gas recovery and drainage system has two working modes. When the operation is in progress, the first working mode is started first. When the pressure sensor 6 detects that the pressure in the water-dividing buffer tank 9 rises to be equal to the pressure at the rear end of the high-pressure component 2, it switches to the second working mode. When the pressure in the water-dividing buffer tank 9 drops by 30 kPa, it returns to the first working mode again, and the cycle repeats.

[0046] The first working mode is specifically as follows: the third solenoid valve 5 is closed, the first solenoid valve 3 and the second solenoid valve 7 are opened, and the gas provided by the gas cylinder 1 passes through the high-pressure component 2, the first solenoid valve 3, and the ultrasonic humidifier 4 in sequence, and then enters the fuel cell stack 11 from the inlet of the fuel cell stack 11 to participate in the reaction; in the first working mode, the water separation buffer tank 9 is in a low-pressure state. Under the action of the pressure difference, the tail gas generated in the fuel cell stack 11 enters the water separation buffer tank 9 after passing through the second solenoid valve 7. With the continuous entry of the tail gas, the pressure in the water separation buffer tank 9 gradually increases, and the liquid water in the tail gas is separated in the water separation buffer tank 9 and stored at the bottom of the water separation buffer tank 9;

[0047] The second working mode is specifically as follows: close the first solenoid valve 3 and the second solenoid valve 7, open the third solenoid valve 5, and the gas in the water-dividing buffer tank 9 flows out from the first outlet, passes through the third solenoid valve 5, and enters the fuel cell stack 11 from the inlet of the fuel cell stack to participate in the reaction. As the gas in the water-dividing buffer tank 9 is continuously consumed, the pressure in the water-dividing buffer tank 9 gradually decreases. In the second working mode, the humidity of the gas in the water-dividing buffer tank 9 is relatively high, and no ultrasonic humidifier 4 is required for humidification.

[0048] The liquid water stored in the water-dividing buffer tank 9 flows out through the second outlet of the water-dividing buffer tank 9, passes through the one-way valve 8 and enters the ultrasonic humidifier 4, and is used to atomize and humidify the gas entering the fuel cell stack 11, so as to realize the utilization of water produced by the fuel cell stack.

[0049] The calculation method of the volume V of the water-dividing buffer tank 9 is as follows:

[0050] The water storage ratio of the water-dividing buffer tank 9 is set to 30%. When the liquid water in the water-dividing buffer tank 9 exceeds 30%, the fourth solenoid valve 10 is opened to discharge part of the liquid water. When the liquid water storage ratio in the water-dividing buffer tank 9 is 30%, the volume V of the water-dividing buffer tank 9 is calculated. The specific calculation is as follows:

[0051] V=V g / (1-30%) (1);

[0052] Where V g is the effective gas volume of the water distribution buffer tank, which is calculated as follows:

[0053] V g =m*R g *T / ΔP (2);

[0054] Where m is the fluctuation value of the gas mass in the water separation buffer tank when the two working modes are switched; R g is the molar gas constant of the reaction gas; T is the operating temperature of the fuel cell stack; ΔP is the fluctuation value of the gas pressure in the water-dividing buffer tank when the two working modes are switched, ΔP = 30 kPa; According to experimental research, the performance is best when the gas pressure fluctuation is 30 kPa.

[0055] The fluctuation value m of the gas mass in the water-dividing buffer tank when the two working modes are switched is calculated by the following formula:

[0056] m=t*m max (3);

[0057] Where, t is the duration of the second working mode, t = 2min. According to experimental research, the stack performance is best when t is 2min. max is the maximum gas consumption rate of the stack, calculated by the following formula:

[0058] m max =I*M*k / z / F (4);

[0059] Wherein, I is the rated operating current of the stack; M is the molar mass of the reaction gas. When the system is used in a hydrogen supply system, the reaction gas is hydrogen, and the value of M is 2. When the system is used in a supply system using pure oxygen, the reaction gas is oxygen, and the value of M is 32. k is the number of cells in the stack; z is the number of reaction charge transfers. When the system is used in a hydrogen supply system, the reaction gas is hydrogen, and the value of z is 2. When the system is used in a supply system using pure oxygen, the reaction gas is oxygen, and the value of z is 4. F is the Faraday constant.

[0060] Molar gas constant R of the reaction gas g Calculated by the following formula:

[0061] R g =R / M (5);

[0062] Wherein, R is the molar gas constant, R=8.314J / (mol·K); M is the molar mass of the reaction gas. When the system is used for a hydrogen supply system, the reaction gas is hydrogen, and the value of M is 2. When the system is used for a supply system using pure oxygen, the reaction gas is oxygen, and the value of M is 32.

[0063] By setting a water-dividing buffer tank and coordinating the opening of the solenoid valve, two working modes are formed. In the first working mode, the water-dividing buffer tank recovers the reaction gas and the water produced by the fuel cell stack; in the second working mode, the recovered gas stored in the water-dividing buffer tank is directly supplied to the fuel cell stack reaction as a gas source; this cycle is repeated to realize the gas recycling function of the small-power fuel cell.

[0064] By setting up a water separation buffer tank, the gas reflux structure and the water separation structure are combined, and by connecting the water separation buffer tank with the ultrasonic humidifier, the reflux structure, the water separation structure and the humidification structure are highly integrated, replacing the traditional membrane humidifier, avoiding the problems of high cost and short life brought about by the use of traditional membrane humidifiers, and also reducing the product cost and system complexity.

[0065] By designing a calculation method for the volume of the water distribution buffer tank, a reasonable volume of the water distribution buffer tank is calculated according to specific use conditions to improve the working efficiency of the system.

[0066] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fuel cell tail gas recovery and drainage system, characterized in that: The invention comprises a gas cylinder (1), a high-pressure component (2), a first solenoid valve (3), an ultrasonic humidifier (4), a second solenoid valve (7), a water-dividing buffer tank (9), a third solenoid valve (5), and a pressure sensor (6); the gas provided by the gas cylinder (1) passes through the high-pressure component (2), the first solenoid valve (3), and the ultrasonic humidifier (4) in sequence, and then enters the cell stack (11) from the inlet of the cell stack (11) to participate in the reaction; the outlet of the cell stack (11) is connected to the inlet of the water-dividing buffer tank (9) via a pipeline, and a second solenoid valve (7) is provided on the connecting pipeline between the outlet of the cell stack (11) and the water-dividing buffer tank (9); the first outlet of the water-dividing buffer tank (9) is connected to the inlet of the cell stack (11) via a pipeline, and a third solenoid valve (5) is provided on the connecting pipeline between the water-dividing buffer tank (9) and the inlet of the cell stack (11); and a pressure sensor (6) is provided in the water-dividing buffer tank (9) for monitoring the pressure in the water-dividing buffer tank (9).

2. The fuel cell tail gas recovery and drainage system according to claim 1, characterized in that: The second outlet of the water separation buffer tank (9) is connected to the ultrasonic humidifier (4) via a pipeline, and a one-way valve (8) is provided on the connecting pipeline between the water separation buffer tank (9) and the ultrasonic humidifier (4). The liquid water separated by the water separation buffer tank (9) is used to replenish water for the ultrasonic humidifier (4).

3. The fuel cell tail gas recovery and drainage system according to claim 1, characterized in that: The third outlet of the water-dividing buffer tank (9) is provided with a drainage pipe for discharging excess water in the water-dividing buffer tank (9) out of the system, and the drainage pipe is provided with a fourth solenoid valve (10) for controlling whether the water in the water-dividing buffer tank (9) is discharged.

4. A working method of the fuel cell tail gas recovery and drainage system according to any one of claims 1 to 3, characterized in that: The working method is as follows: The fuel cell tail gas recovery and drainage system has two working modes. During operation, the first working mode is first started. When the pressure sensor (6) detects that the pressure in the water separation buffer tank (9) rises to be equal to the air pressure at the rear end of the high-pressure component (2), the second working mode is switched. When the pressure in the water separation buffer tank (9) drops by 30 kPa, the first working mode is returned again, and the cycle repeats. The first working mode is specifically as follows: the third solenoid valve (5) is closed, the first solenoid valve (3) and the second solenoid valve (7) are opened, and the gas provided by the gas cylinder (1) passes through the high-pressure component (2), the first solenoid valve (3), and the ultrasonic humidifier (4) in sequence, and then enters the fuel cell stack (11) from the inlet of the fuel cell stack (11) to participate in the reaction; in the first working mode, the water separation buffer tank (9) is in a low-pressure state, and under the action of the pressure difference, the tail gas generated in the fuel cell stack (11) enters the water separation buffer tank (9) after passing through the second solenoid valve (7), and as the tail gas continues to enter, the pressure in the water separation buffer tank (9) gradually increases, and the liquid water in the tail gas is separated in the water separation buffer tank (9) and stored at the bottom of the water separation buffer tank (9); The second working mode is specifically as follows: the first solenoid valve (3) and the second solenoid valve (7) are closed, and the third solenoid valve (5) is opened, so that the gas in the water-dividing buffer tank (9) flows out from the first outlet, passes through the third solenoid valve (5), and enters the fuel cell stack (11) through the inlet of the fuel cell stack (11) to participate in the reaction, and as the gas in the water-dividing buffer tank (9) is continuously consumed, the pressure in the water-dividing buffer tank (9) gradually decreases.

5. The working method of the fuel cell tail gas recovery and drainage system according to claim 4, characterized in that: Liquid water stored in the water separation buffer tank (9) flows out through the second outlet of the water separation buffer tank (9), passes through a one-way valve (8), and enters the ultrasonic humidifier (4), and is used to atomize and humidify the gas entering the fuel cell stack (11).

6. The working method of the fuel cell tail gas recovery and drainage system according to claim 4, characterized in that: The volume V of the water-dividing buffer tank (9) is calculated as follows: The water storage ratio of the water distribution buffer tank (9) is set to 30%. When the liquid water in the water distribution buffer tank (9) exceeds 30%, the fourth solenoid valve (10) is opened to discharge part of the liquid water. When the liquid water storage ratio in the water distribution buffer tank (9) is 30%, the volume V of the water distribution buffer tank (9) is calculated. The specific calculation is as follows: V=V g / (1-30%) (1); Where V g It is the effective gas volume of the water distribution buffer tank.

7. The operating method of the fuel cell tail gas recovery and drainage system according to claim 6, characterized in that: Effective gas volume V of water separation buffer tank g The specific calculation is as follows: V g =m*R g *T / ΔP (2); Where m is the fluctuation value of the gas mass in the water separation buffer tank when the two working modes are switched; R g is the molar gas constant of the reaction gas; T is the operating temperature of the fuel cell stack; ΔP is the fluctuation value of the gas pressure in the water separation buffer tank when the two working modes are switched, ΔP = 30 kPa.

8. The operating method of the fuel cell tail gas recovery and drainage system according to claim 7, characterized in that: The fluctuation value m of the gas mass in the water-dividing buffer tank when the two working modes are switched is calculated by the following formula: m=t*m max (3); Where, t is the duration of the second working mode, t = 2min; m max is the maximum gas consumption rate of the fuel cell stack.

9. The operating method of the fuel cell tail gas recovery and drainage system according to claim 8, characterized in that: Maximum gas consumption rate of the fuel cell stack m max Calculated by the following formula: m max =I*M*k / z / F (4); Wherein, I is the rated operating current of the stack; M is the molar mass of the reaction gas. When the system is used in a hydrogen supply system, the reaction gas is hydrogen, and the value of M is 2. When the system is used in a supply system using pure oxygen, the reaction gas is oxygen, and the value of M is 32. k is the number of cells in the stack; z is the number of reaction charge transfers. When the system is used in a hydrogen supply system, the reaction gas is hydrogen, and the value of z is 2. When the system is used in a supply system using pure oxygen, the reaction gas is oxygen, and the value of z is 4. F is the Faraday constant.

10. The operating method of the fuel cell tail gas recovery and drainage system according to claim 7, characterized in that: Molar gas constant R of the reaction gas g Calculated by the following formula: R g =R / M (5); Wherein, R is the molar gas constant, R=8.314J / (mol·K); M is the molar mass of the reaction gas. When the system is used for a hydrogen supply system, the reaction gas is hydrogen, and the value of M is 2. When the system is used for a supply system using pure oxygen, the reaction gas is oxygen, and the value of M is 32.

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