CN114839106A - Method, system, vehicle and medium for measuring hydrogen concentration of fuel cell - Google Patents

Abstract

The invention relates to the technical field of fuel cells, in particular to a method, a system, a vehicle and a medium for measuring the hydrogen concentration of a fuel cell; the method comprises the steps of carrying out gas-liquid separation on gas at the outlet of the hydrogen circulating pump, and heating the separated gas until the relative humidity is less than 100%; acquiring the temperature of the gas before heating and the saturated pressure at the corresponding temperature, the temperature of the heated gas and the saturated pressure, humidity and volume of the heated hydrogen at the corresponding temperature, and calculating to obtain the volume fraction of the heated hydrogen and the humidity RH of the gas before heating ₉ If RH ₉ Is more than 100 percent; calculating to obtain the final volume fraction of the hydrogen; if the gas humidity RH ₉ Less than or equal to 100%, the volume fraction of hydrogen after heating is equal to the final volume fraction of hydrogen; the invention can realize the hydrogen concentration test with low development cost, simple structure and high reliability; through heating the gas after separating, can prevent the condensation of saturated vapor, guarantee the accuracy of measurement.

Description

A fuel cell hydrogen concentration measurement method, system, vehicle and medium

technical field

The present invention relates to the technical field of fuel cells, in particular to a method, system, vehicle and medium for measuring hydrogen concentration of fuel cells.

Background technique

The working principle of proton exchange membrane fuel cell is that hydrogen and oxygen undergo electrochemical reaction to generate water and output electricity at the same time. Since the voltage of the fuel cell is usually less than 1V, in practical application, it is necessary to connect hundreds of cells in series to form a fuel cell stack, and match the corresponding peripheral accessories to form a fuel cell system.

Hydrogen is one of the reactants in the electrochemical reaction of fuel cells. In the existing fuel cell system, hydrogen is usually recycled on the anode side with the help of a hydrogen circulation pump or an ejector to improve the utilization rate of hydrogen, but its concentration is serious. It affects the output performance and life of the stack. Since the anode side usually carries liquid water, the existing hydrogen concentration sensor is easily affected by liquid water and leads to functional failure. Therefore, it is necessary to develop an appropriate technology to monitor the hydrogen concentration on the anode side.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a fuel cell hydrogen concentration measurement method, system, vehicle and medium with simple structure and low cost.

In order to solve the above-mentioned technical problems, the first technical scheme adopted by the present invention is:

A method for measuring hydrogen concentration in a fuel cell, comprising:

Gas-liquid separation is performed on the gas at the outlet of the hydrogen circulation pump, and the separated gas is heated, and the relative humidity of the heated gas is less than 100%; the temperature T ₇ before the gas heating and the saturated pressure p _sat ( _T7 );

Obtain the temperature T ₁₀ , the pressure p ₁₀ , the humidity RH ₁₀ , the saturation pressure p _sat (T ₁₀ ) at the corresponding temperature, the hydrogen volume x _H2,11 after heating, and the hydrogen volume fraction x _w,11 after heating, so The calculation method of the hydrogen volume fraction x _{w, 11} after the heating is:

The gas humidity RH ₉ before heating is obtained according to the heated gas temperature T ₁₀ and the humidity RH ₁₀ , and the calculation method of the gas humidity RH ₉ is:

If RH ₉ >100%; then the final hydrogen volume fraction x _{H2, the final} calculation method is:

If the gas humidity RH ₉ ≤ 100%, the hydrogen volume fraction x _w,11 after heating is equal to the final hydrogen volume fraction x _H2,final .

In order to solve the above-mentioned technical problems, the second technical scheme adopted by the present invention is:

A battery hydrogen concentration measurement system, comprising a measurement loop and a gas-liquid separation component, a heating element, a temperature, pressure and humidity sensor and a hydrogen concentration sensor arranged in sequence on the measurement loop;

A temperature and pressure sensor is arranged on the measurement loop before the heating element.

In order to solve the above-mentioned technical problems, the third technical scheme adopted by the present invention is:

A vehicle, comprising a fuel cell, the fuel cell comprising a hydrogen circulation pump, the hydrogen circulation pump comprising an inlet and an outlet, and the battery hydrogen concentration measurement system described above;

The measurement loop of the battery hydrogen concentration measurement system is connected in parallel with the hydrogen circulation pump including the inlet and the outlet;

One end of the measurement loop with the gas-liquid separation assembly is connected to the inlet.

In order to solve the above-mentioned technical problems, the fourth technical scheme adopted by the present invention is:

A medium having stored thereon a computer program that, when executed by a processor, implements the method for measuring the hydrogen concentration of a fuel cell as described above.

The beneficial effects of the present invention are as follows: through the battery hydrogen concentration measurement system and method of the present invention, a hydrogen concentration test with low development cost, simple structure and high reliability can be realized; and the system is complicated and the cost is high in order to achieve measurement in the prior art. By heating the separated gas, the relative humidity of the heated gas is less than 100%, increasing the saturated vapor pressure, preventing the condensation of saturated water vapor, and ensuring the accuracy of the measurement.

Description of drawings

1 is a schematic structural diagram of a fuel cell hydrogen concentration measurement system according to a specific embodiment of the present invention;

Label description: 1. Control valve; 2. Hydrogen circulation pump; 3. Electromagnetic purge valve; 4. Electric stack; 5. Pressure regulating valve; 6. Air compressor; 7. Temperature and pressure sensor; 8. Water separation piece; 9. Waterproof and breathable parts; 10. Temperature, pressure and humidity sensor; 11. Hydrogen concentration sensor; 12. Heating element; 13. Measuring circuit.

Detailed ways

In order to describe in detail the technical content, achieved objects and effects of the present invention, the following descriptions are given with reference to the embodiments and the accompanying drawings.

Please refer to FIG. 1, a method for measuring the hydrogen concentration of a fuel cell, comprising:

Gas-liquid separation is performed on the gas at the outlet of the hydrogen circulation pump, and the separated gas is heated, and the relative humidity of the heated gas is less than 100%; the temperature T ₇ before the gas heating and the saturated pressure p _sat ( _T7 );

Obtain the temperature T ₁₀ , the pressure p ₁₀ , the humidity RH ₁₀ , the saturation pressure p _sat (T ₁₀ ) at the corresponding temperature, the hydrogen volume x _H2,11 after heating, and the hydrogen volume fraction x _w,11 after heating, so The calculation method of the hydrogen volume fraction x _{w, 11} after the heating is:

The gas humidity RH ₉ before heating is obtained according to the heated gas temperature T ₁₀ and the humidity RH ₁₀ , and the calculation method of the gas humidity RH ₉ is:

If RH ₉ >100%; then the final hydrogen volume fraction x _{H2, the final} calculation method is:

If the gas humidity RH ₉ ≤ 100%, the hydrogen volume fraction x _w,11 after heating is equal to the final hydrogen volume fraction x _H2,final .

Further, the flow ratio before the gas-liquid separation and after the gas-liquid separation is less than 5%.

It can be seen from the above description that the flow ratio before gas-liquid separation and after gas-liquid separation is less than 5% to avoid the influence of the measurement process on the normal operation of the system; optionally, if the flow ratio is less than 5%, the flow in the measurement loop can be Released to the atmosphere in a safe manner.

Further, the flow ratio before the gas-liquid separation and after the gas-liquid separation is 1%.

Further, it also includes the final nitrogen volume fraction x _N2 ; if RH ₉ >100%; the calculation method of the final nitrogen volume fraction x _N2 is:

If the gas humidity RH ₉ ≤ 100%, the final nitrogen volume fraction x _N2 is calculated as:

x _N2 = 1-x _{H2, final} -x _{w, 11} .

A battery hydrogen concentration measurement system, comprising a measurement loop and a gas-liquid separation component, a heating element, a temperature, pressure and humidity sensor and a hydrogen concentration sensor arranged in sequence on the measurement loop;

A temperature and pressure sensor is arranged on the measurement loop before the heating element.

Further, the gas-liquid separation assembly includes a water dividing member and a waterproof and air-permeable partner arranged in sequence along the measurement circuit.

Further, a flow sensor is also provided on the measurement loop after the hydrogen concentration sensor.

It can be seen from the above description that the gas composition can be accurately calculated by setting the flow sensor.

Further, a pressure regulating member is also provided on the measurement loop after the hydrogen concentration sensor.

It can be seen from the above description that, through the arrangement of the pressure regulating element, the flow rate in the measurement loop can be precisely controlled, so that the ratio of the flow rate in the loop to the flow rate in the circulation loop is less than 5%.

A vehicle, comprising a fuel cell, the fuel cell comprising a hydrogen circulation pump, the hydrogen circulation pump comprising an inlet and an outlet, and the above-mentioned battery hydrogen concentration measurement system;

The measurement loop of the battery hydrogen concentration measurement system is connected in parallel with the hydrogen circulation pump including the inlet and the outlet;

One end of the measurement loop with the gas-liquid separation assembly is connected to the inlet.

A medium having stored thereon a computer program that, when executed by a processor, implements the above-described method for measuring hydrogen concentration in a fuel cell.

As can be seen from the above description, the battery hydrogen concentration measurement system and method of the present invention can realize the hydrogen concentration measurement with low development cost, simple structure and high reliability; and overcome the problems of complicated system and high cost in the prior art in order to realize the measurement. .

Example 1

A method for measuring hydrogen concentration in a fuel cell, comprising:

Gas-liquid separation is performed on the gas at the outlet of the hydrogen circulating pump, and the separated gas is heated. The relative humidity of the heated gas is less than 100% or less than 80%; the temperature _T7 before gas heating and the saturation at the corresponding temperature are obtained. air pressure p _sat (T ₇ );

Obtain the temperature T ₁₀ , the pressure p ₁₀ , the humidity RH ₁₀ , the saturation pressure p _sat (T ₁₀ ) at the corresponding temperature, the hydrogen volume x _H2,11 after heating, and the hydrogen volume fraction x _w,11 after heating, so The calculation method of the hydrogen volume fraction x _{w, 11} after the heating is:

Obtain the gas humidity RH ₉ before heating according to the gas temperature T ₁₀ after heating and humidity RH ₁₀ (T ₇ is used in the formula because the temperature change in the measurement loop is very small before and after gas-liquid separation, which can be ignored and regarded as equivalent , so it is directly used as the temperature after gas-liquid separation), and the calculation method of the gas humidity RH ₉ is:

If RH ₉ >100%; then the final hydrogen volume fraction x _{H2, the final} calculation method is:

If the gas humidity RH ₉ ≤ 100%, the hydrogen volume fraction x _w,11 after heating is equal to the final hydrogen volume fraction x _H2,final .

The flow ratio before the gas-liquid separation and after the gas-liquid separation is 1%.

It also includes the final nitrogen volume fraction x _N2 ; if RH ₉ >100%; then the final nitrogen volume fraction x _N2 is calculated as:

If the gas humidity RH ₉ ≤ 100%, the final nitrogen volume fraction x _N2 is calculated as:

x _N2 = 1-x _{H2, final} -x _{w, 11} .

in

Referring to FIG. 1 , T ₇ is the temperature at the temperature and pressure sensor 7 , and p _sat (T ₇ ) is the saturated air pressure at the corresponding temperature of the temperature and pressure sensor 7 ;

T ₁₀ , p ₁₀ , and RH ₁₀ are the temperature, pressure, and humidity at the temperature, pressure, and humidity sensor 10 , and p _sat (T ₁₀ ) is the saturated air pressure at the corresponding temperature of the temperature, pressure, and humidity sensor 10 ;

x _H2 , 11 is the hydrogen volume after heating obtained at the hydrogen concentration sensor;

RH ₉ is the gas humidity at the waterproof vent 9 .

Embodiment 2

Referring to Fig. 1, a battery hydrogen concentration measurement system includes a measurement loop 13 and a gas-liquid separation assembly, a heating element 12, a temperature, pressure and humidity sensor 10 and a hydrogen concentration sensor 11 arranged in sequence on the measurement loop 13;

A temperature and pressure sensor 7 is arranged on the measurement loop 13 before the heating element.

The gas-liquid separation assembly includes a water dividing member 8 and a waterproof ventilation member 9 arranged in sequence along the measuring circuit 13 .

A flow sensor is also provided on the measurement loop 13 after the hydrogen concentration sensor 11 .

A pressure regulating member is also provided on the measurement circuit 13 after the hydrogen concentration sensor 11 .

in

Described water divider 8 is the water divider of SMC model, can choose to remove the liquid water particle diameter greater than 50um in gas; Described waterproof breathable member 9 is waterproof breathable valve, in theory, can only allow hydrogen, nitrogen, water Gases such as steam pass through, and liquid water particles are not allowed to pass through. The e-PTFE film material used has a pore size between 0.1-10um. The liquid water particles are generally larger than this range, and the diameter of the gas molecules is 0.4nm. High contact angle and other characteristics can effectively achieve gas-water separation.

Embodiment 3

1, a vehicle includes a fuel cell, the fuel cell includes a control valve 1, a hydrogen circulation pump 2, an electromagnetic purge valve 3, an electric stack 4, a pressure regulating valve 5, and an air compressor 6, the hydrogen gas passes through The control valve 1 enters into the stack 4, the air enters into the stack 4 through the air compressor 6, the electromagnetic purge valve 3 controls the discharge of reaction products, and the pressure regulating valve 5 controls the discharge of the stack 4. pressure; the hydrogen circulation pump 2 includes an inlet and an outlet,

Also includes the battery hydrogen concentration measurement system described in Embodiment 1;

The measurement loop 13 of the battery hydrogen concentration measurement system is connected in parallel with the hydrogen circulation pump 2 including the inlet and the outlet;

One end of the measuring circuit 13 with the gas-liquid separation assembly is connected to the inlet.

The measuring loop 13 is set close to the outlet of the hydrogen circulation pump 2 as the starting end, and the inlet close to the hydrogen circulating pump 2 is the ending end. 8. The waterproof ventilation member 9 , the heating member 12 , the temperature, pressure and humidity sensor 10 and the hydrogen concentration sensor 11 .

Embodiment 4

A medium on which a computer program is stored, and when the computer program is executed by a processor, implements the method for measuring the hydrogen concentration of a fuel cell as described in the first embodiment.

The above descriptions are only examples of the present invention, and are not intended to limit the scope of the patent of the present invention. Any equivalent transformations made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in related technical fields, are similarly included in the within the scope of patent protection of the present invention.

Claims (10)

1. a measuring method of hydrogen concentration of fuel cell, is characterized in that, comprises Gas-liquid separation is performed on the gas at the outlet of the hydrogen circulation pump, and the separated gas is heated, and the relative humidity of the heated gas is less than 100%; the temperature T ₇ before the gas heating and the saturated pressure p _sat ( _T7 ); Obtain the temperature T ₁₀ , the pressure p ₁₀ , the humidity RH ₁₀ , the saturation pressure p _sat (T ₁₀ ) at the corresponding temperature, the hydrogen volume x _H2,11 after heating, and the hydrogen volume fraction x _w,11 after heating, so The calculation method of the hydrogen volume fraction x _{w, 11} after the heating is:

The gas humidity RH ₉ before heating is obtained according to the heated gas temperature T ₁₀ and the humidity RH ₁₀ , and the calculation method of the gas humidity RH ₉ is:

If RH ₉ >100%; then the final hydrogen volume fraction x _{H2, the final} calculation method is:

If the gas humidity RH ₉ ≤ 100%, the hydrogen volume fraction x _w,11 after heating is equal to the final hydrogen volume fraction x _H2,final . 2 . The method for measuring hydrogen concentration of a fuel cell according to claim 1 , wherein the flow ratio before the gas-liquid separation and after the gas-liquid separation is less than 5%. 3 . 3 . The method for measuring hydrogen concentration of a fuel cell according to claim 2 , wherein the flow ratio before the gas-liquid separation and after the gas-liquid separation is 1%. 4 . 4. The method for measuring the hydrogen concentration of a fuel cell according to claim 1, further comprising: the final nitrogen volume fraction x _N2 ; if RH ₉ >100%; the calculation method of the final nitrogen volume fraction x _N2 is:

If the gas humidity RH ₉ ≤ 100%, the final nitrogen volume fraction x _N2 is calculated as: x _N2 = 1-x _{H2, final} -x _{w, 11} . 5. A battery hydrogen concentration measurement system, characterized in that it comprises a measurement loop and a gas-liquid separation assembly, a heating element, a temperature, pressure and humidity sensor and a hydrogen concentration sensor sequentially arranged on the measurement loop; A temperature and pressure sensor is arranged on the measurement loop before the heating element. 6 . The battery hydrogen concentration measurement system according to claim 5 , wherein the gas-liquid separation component comprises a water separation member and a waterproof ventilation member arranged in sequence along the measurement loop. 7 . 7 . The battery hydrogen concentration measurement system according to claim 5 , wherein a flow sensor is further provided on the measurement loop after the hydrogen concentration sensor. 8 . 8 . The battery hydrogen concentration measurement system according to claim 5 , wherein a pressure regulating member is further provided on the measurement loop after the hydrogen concentration sensor. 9 . 9. A vehicle, comprising a fuel cell, the fuel cell comprising a hydrogen circulation pump, the hydrogen circulation pump comprising an inlet and an outlet, characterized in that, further comprising the battery hydrogen concentration measurement according to any one of claims 5-8 system; The measurement loop of the battery hydrogen concentration measurement system is connected in parallel with the hydrogen circulation pump including the inlet and the outlet; One end of the measurement loop with the gas-liquid separation assembly is connected to the inlet. 10. A medium on which a computer program is stored, characterized in that, when the computer program is executed by a processor, the method for measuring hydrogen concentration of a fuel cell according to any one of claims 1-4 is implemented.

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