Control method for monitoring hydrogen backflow system on line

Abstract

The invention relates to the technical field of fuel cells, in particular to a control method for monitoring a hydrogen backflow system on line. Comprising a galvanic pile module, an ejector is arranged on a hydrogen inlet pipeline of the galvanic pile module, a hydrogen outlet pipeline of the galvanic pile module is connected with a gas-liquid separator, a gas outlet of the gas-liquid separator is connected with the ejector through a hydrogen circulating pump, and a temperature-humidity-pressure integrated sensor is arranged on the hydrogen inlet pipeline. A temperature-humidity-pressure integrated sensor is arranged between the gas-liquid separator and the hydrogen circulating pump, the hydrogen return flow Q hydrogen return is obtained according to data collected by the temperature-humidity-pressure integrated sensor and the temperature-pressure integrated sensor, the hydrogen return flow Q hydrogen return is monitored, and then the hydrogen inlet flow is controlled. Compared with the prior art, the hydrogen return flow is monitored in real time, so that the flow of hydrogen entering a galvanic pile is controlled, the normal action of a hydrogen fuel cell system is ensured, and the service life of the hydrogen fuel cell system is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cells, in particular to a control method for online monitoring of a hydrogen reflux system. Background Art

[0002] At present, in order to ensure that the stack is in a better working state and improve the utilization rate of hydrogen, the anode hydrogen circulation of the hydrogen fuel cell system has become a necessary function of the system. However, the difference in the reflux flow directly affects the working efficiency and life of the stack. The size of the reflux flow directly affects the stoichiometric ratio and humidity of the hydrogen entering the anode of the stack. If the reflux flow is too small, the anode hydrogen stoichiometric ratio of the stack will be insufficient, resulting in insufficient gas and low humidity, which will affect the life of the stack. Therefore, online monitoring of the hydrogen reflux flow can improve the system power and extend the system service life. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present invention provides a control method for online monitoring of a hydrogen reflux system.

[0004] In order to achieve the above purpose, a control method for online monitoring of a hydrogen reflux system is designed, including a fuel cell module, an ejector is arranged on the hydrogen inlet pipeline of the fuel cell module, a hydrogen outlet pipeline of the fuel cell module is connected to a gas-liquid separator, a gas outlet of the gas-liquid separator is connected to the ejector through a hydrogen circulation pump, a temperature, humidity and pressure integrated sensor is arranged on the hydrogen inlet pipeline, a temperature and pressure integrated sensor is arranged between the gas-liquid separator and the hydrogen circulation pump, and a hydrogen return flow rate Q is obtained according to the data collected by the temperature, humidity and pressure integrated sensor and the temperature and pressure integrated sensor 回氢 , for the hydrogen return flow Q 回氢 Monitor and control the hydrogen flow rate.

[0005] The hydrogen return flow rate Q is obtained 回氢 The method comprises the following steps: S1, calculates the mass fraction m1 of water vapor entering the reactor based on the data collected by the temperature, humidity and pressure integrated sensor; S2, calculate the mass fraction m2 of the reflux water vapor based on the data collected by the temperature and pressure integrated sensor; S3, Q is obtained based on the mass fraction of the incoming steam m1 and the mass fraction of the reflux steam m2. 回氢 .

[0006] The specific method of step S1 is as follows: S11, using the integrated temperature, humidity and pressure sensor to measure the total pressure P1, humidity RH1 and temperature T1 of the pile; S12, look up the table or empirical formula to obtain the saturated water vapor pressure P entering the stack s1 ; S13, then the actual water vapor pressure entering the pile, P w1 =P s1*RH1; S14, get the water content entering the pile (per gram of hydrogen), w1=9*P w1 / (P1-P w1 ); S15, and then obtain the mass fraction of water vapor entering the stack, m1=w1 / (1+w1).

[0007] The specific method of step S2 is as follows: S21: measuring the total pressure P2 and temperature T2 of the reflux hydrogen by a temperature-pressure integrated sensor; S22, hydrogen reflux humidity is 100%, look up the table or empirical formula to obtain the reflux saturated water vapor pressure P s2 ; S23, get the reflux water content (per gram of hydrogen), w2=9*P s2 / (P2-P s2 ); S24, and then obtain the mass fraction of reflux water vapor m2=w2 / (1+w2).

[0008] The specific method of step S3 is as follows: S31, since the water entering the reactor comes from the reflux water, we get (Q 回氢 +Q 回水蒸汽 )*m2=(Q 回氢 +Q 回水蒸汽 +Q 进氢 )*m1, that is, Q 回氢 +Q 回水蒸汽 =Q 进氢* m1 / (m 2- m1), i.e. Q 回总 =Q 进氢* m1 / (m 2- m1); S32, due to the reflux steam flow Q 回水蒸汽 =Q 回总 *m2= Q 进氢* m1*m2 / (m 2- m1); S33, then we get Q 回氢 = Q 进氢* m1 / (m 2- m1)- Q 进氢* m1*m2 / (m 2- m1).

[0009] In step S3, Q 进氢 The hydrogen supply system is controlled by the vehicle controller in each power range to provide a calibrated hydrogen flow rate, which is the value calibrated in advance.

[0010] According to the hydrogen return flow rate Q回氢 , control the speed of the hydrogen circulation pump and the return hydrogen flow rate Q 回氢 Control is performed to thereby control the flow of hydrogen entering the fuel cell stack module.

[0011] The liquid outlet of the gas-liquid separator is connected to a drain valve.

[0012] The inlet of the hydrogen gas inlet pipeline is connected to a hydrogen source, and a hydrogen inlet solenoid valve and a proportional valve are also arranged on the hydrogen gas inlet pipeline.

[0013] Compared with the prior art, the present invention monitors the return hydrogen flow in real time, thereby controlling the hydrogen flow entering the fuel cell stack, ensuring the normal functioning of the hydrogen fuel cell system, and extending the service life of the hydrogen fuel cell system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention.

[0015] Figure 2 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] like Figure 1 As shown, in this embodiment, the online monitoring hydrogen reflux system includes a fuel cell module, an ejector 3 is provided on the hydrogen inlet pipeline 2 of the fuel cell module 1, a hydrogen outlet pipeline 4 of the fuel cell module 1 is connected to a gas-liquid separator 5, a gas outlet of the gas-liquid separator 5 is connected to the ejector 3 through a hydrogen circulation pump 6, a temperature, humidity and pressure integrated sensor 7 is provided on the hydrogen inlet pipeline 2, a temperature and pressure integrated sensor 8 is provided between the gas-liquid separator 5 and the hydrogen circulation pump 6, and the return hydrogen flow rate Q is obtained according to the data collected by the temperature, humidity and pressure integrated sensor 7 and the temperature and pressure integrated sensor 8. 回氢 , for the hydrogen return flow Q 回氢 Monitor and control the hydrogen flow rate.

[0018] The hydrogen return flow rate Q is obtained 回氢 The method comprises the following steps: S1, calculate the mass fraction m1 of water vapor entering the stack based on the data collected by the temperature, humidity and pressure integrated sensor 7. Specifically: S11, measure the total pressure P1, humidity RH1 and temperature T1 entering the stack based on the temperature, humidity and pressure integrated sensor 7; S12, obtain the saturated water vapor pressure P entering the stack by looking up a table or empirical formula s1 ; S13, then the actual water vapor pressure entering the pile, P w1 =P s1 *RH1; S14, get the water content entering the pile (per gram of hydrogen), w1=9*P w1 / (P1-P w1); S15, and then obtain the mass fraction of water vapor entering the stack, m1=w1 / (1+w1).

[0019] Since the hydrogen outlet contains a large amount of liquid water, the hydrogen after the gas-liquid separator is 100% humidified. S2, calculate the mass fraction m2 of the reflux water vapor based on the data collected by the temperature-pressure integrated sensor 8. The details are as follows: S21: measure the total pressure P2 and temperature T2 of the reflux hydrogen through the temperature-pressure integrated sensor 8; S22, obtain the reflux saturated water vapor pressure P by looking up a table or empirical formula s2 ; S23, get the reflux water content (per gram of hydrogen), w2=9*P s2 / (P2-P s2 ); S24, and then obtain the mass fraction of reflux water vapor m2=w2 / (1+w2).

[0020] S3, Q is obtained based on the mass fraction of the incoming steam m1 and the mass fraction of the reflux steam m2. 回氢 The details are as follows: S31, since the water entering the pile comes from the reflux water, we get (Q 回氢 +Q 回水蒸汽 )*m2=(Q 回氢 +Q 回水蒸汽 +Q 进氢 )*m1, that is, Q 回氢 +Q 回水蒸汽 =Q 进氢* m1 / (m 2- m1), i.e. Q 回总 =Q 进氢* m1 / (m 2- m1); S32, due to the reflux steam flow Q 回水蒸汽 =Q 回总 *m2= Q 进氢* m1*m2 / (m 2- m1); S33, then we get Q 回氢 = Q 进氢* m1 / (m 2- m1)- Q 进氢* m1*m2 / (m 2- m1).

[0021] In step S3, Q 进氢 The hydrogen supply system is controlled by the vehicle controller in each power range to provide a calibrated hydrogen flow rate, which is the value calibrated in advance.

[0022] The liquid outlet of the gas-liquid separator 5 is connected to a drain valve 9. The inlet of the hydrogen inlet pipeline 2 is connected to a hydrogen source 10. The hydrogen inlet pipeline 2 is also provided with a hydrogen inlet solenoid valve 11 and a proportional valve 12.

[0023] When this embodiment is used, the vehicle controller controls the hydrogen supply system as the hydrogen source 10 to provide a certain flow of hydrogen, which enters the fuel cell module 1 after passing through the hydrogen inlet solenoid valve 11, the proportional valve 12, and the ejector 3. The temperature, humidity and pressure integrated sensor 7 on the hydrogen inlet pipeline 1 collects the hydrogen pressure, temperature and humidity. After the reaction of the fuel cell module 1, the unreacted hydrogen needs to be refluxed to improve the utilization rate of the hydrogen. This embodiment uses the hydrogen circulation pump 6 and the ejector 3 in series to reflux the unreacted hydrogen, and the temperature and pressure integrated sensor 8 on the hydrogen outlet pipeline 4 collects the reflux hydrogen pressure and temperature. The reflux hydrogen flow rate Q is calculated based on the data detected by the two sensors. 回氢。

[0024] Specifically, if Figure 2 As shown, after the vehicle is started, the hydrogen supply of the hydrogen fuel cell is controlled, that is, the hydrogen flow entering the stack module 1 is controlled. At this time, two sensors collect data to obtain the reflux hydrogen flow Q 回氢 , and then according to the hydrogen return flow Q 回氢 size, controls the speed of hydrogen circulation pump 6, and controls the return hydrogen flow rate Q 回氢 Control is performed to thereby control the flow of hydrogen entering the fuel cell stack module 1.

Claims

1. A control method for online monitoring of a hydrogen reflux system, comprising a fuel cell module, wherein a hydrogen inlet pipeline (2) of the fuel cell module (1) is provided with an ejector (3), a hydrogen outlet pipeline (4) of the fuel cell module (1) is connected to a gas-liquid separator (5), and a gas outlet of the gas-liquid separator (5) is connected to the ejector (3) via a hydrogen circulation pump (6), characterized in that: The hydrogen inlet pipeline (2) is provided with a temperature, humidity and pressure integrated sensor (7), and a temperature and pressure integrated sensor (8) is provided between the gas-liquid separator (5) and the hydrogen circulation pump (6). The return hydrogen flow rate Q is obtained based on the data collected by the temperature, humidity and pressure integrated sensor (7) and the temperature and pressure integrated sensor (8). 回氢 , for the hydrogen return flow Q 回氢 Monitor and control the hydrogen flow rate.

2. A control method for online monitoring of a hydrogen reflux system according to claim 1, characterized in that: The hydrogen return flow rate Q is obtained 回氢 The method comprises the following steps: S1, calculates the mass fraction m1 of water vapor entering the reactor based on the data collected by the temperature, humidity and pressure integrated sensor (7); S2, calculating the mass fraction m2 of the reflux water vapor based on the data collected by the temperature and pressure integrated sensor (8); S3, Q is obtained based on the mass fraction of the incoming steam m1 and the mass fraction of the reflux steam m2. 回氢 .

3. A control method for online monitoring of a hydrogen reflux system according to claim 2, characterized in that: The specific method of step S1 is as follows: S11, measuring the total pressure P1, humidity RH1 and temperature T1 of the pile using the integrated temperature, humidity and pressure sensor (7); S12, look up the table or empirical formula to obtain the saturated water vapor pressure P entering the stack s1 ; S13, then the actual water vapor pressure entering the pile, P w1 =P s1 *RH1; S14, get the water content entering the pile (per gram of hydrogen), w1=9*P w1 / (P1-P w1 ); S15, and then obtain the mass fraction of water vapor entering the stack, m1=w1 / (1+w1).

4. A control method for online monitoring of a hydrogen reflux system according to claim 2, characterized in that: The specific method of step S2 is as follows: S21: measuring the total pressure P2 and temperature T2 of the reflux hydrogen through the integrated temperature and pressure sensor (8); S22, hydrogen reflux humidity is 100%, look up the table or empirical formula to obtain the reflux saturated water vapor pressure P s2 ; S23, get the reflux water content (per gram of hydrogen), w2=9*P s2 / (P2-P s2 ); S24, and then obtain the mass fraction of reflux water vapor m2=w2 / (1+w2).

5. The control method for online monitoring of a hydrogen reflux system according to claim 2, characterized in that: The specific method of step S3 is as follows: S31, since the water entering the reactor comes from the reflux water, we get (Q 回氢 +Q 回水蒸汽 )*m2=(Q 回氢 +Q 回水蒸汽 +Q 进氢 )*m1, that is, Q 回氢 +Q 回水蒸汽 =Q 进氢* m1 / (m 2- m1), i.e. Q 回总 =Q 进氢* m1 / (m 2- m1); S32, due to the reflux steam flow Q 回水蒸汽 =Q 回总 *m2 = Q 进氢* m1*m2 / (m 2- m1); S33, then we get Q 回氢 = Q 进氢* m1 / (m 2- m1)- Q 进氢* m1*m2 / (m 2- m1).

6. A control method for online monitoring of a hydrogen reflux system according to claim 2 or 5, characterized in that: In step S3, Q 进氢 The hydrogen supply system is controlled by the vehicle controller in each power range to provide a calibrated hydrogen flow rate, which is the value calibrated in advance.

7. The control method for online monitoring of a hydrogen reflux system according to claim 1, characterized in that: According to the hydrogen return flow rate Q 回氢 , control the speed of the hydrogen circulation pump (6) and adjust the return hydrogen flow rate Q 回氢 Control is performed to thereby control the flow of hydrogen entering the fuel cell stack module (1).

8. The control method for online monitoring of a hydrogen reflux system according to claim 1, characterized in that: The liquid outlet of the gas-liquid separator (5) is connected to a drain valve (9).

9. The control method for online monitoring of a hydrogen reflux system according to claim 1, characterized in that: The inlet of the hydrogen inlet pipeline (2) is connected to a hydrogen source (10), and the hydrogen inlet pipeline (2) is also provided with a hydrogen inlet solenoid valve (11) and a proportional valve (12).

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