Fuel cell system, control method and automobile

Abstract

The invention provides a fuel cell system, a control method and an automobile, and belongs to the technical field of fuel cells. The fuel cell system comprises the following steps: acquiring the temperature of a copper electrode, the temperature of an output copper bar and the internal environment temperature of a fuel cell box; obtaining the temperature rise temperature of the copper electrode and the output copper bar corresponding to the current of the fuel cell, and obtaining the theoretical upper limit temperature which can be reached by the copper electrode and the output copper bar at the current environment temperature; according to the theoretical upper limit temperature and the temperature redundancy coefficient, calculating to obtain a threshold temperature for judging whether the connection of the copper electrode and the output copper bar is normal; after the fuel cell system is shut down or emergency shut down is completed, the concentration of hydrogen in a fuel cell box is obtained, and it is determined that hydrogen leakage happens to the fuel cell system; and after hydrogen leakage of the fuel cell system occurs, obtaining the internal volume of the fuel cell box body, the hydrogen volume distribution coefficient, the holding pressure, the holding time and the hydrogen concentration, calculating the hydrogen leakage amount of the fuel cell, and controlling the fuel cell system to operate normally.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and particularly relates to a fuel cell system, a control method and an automobile. Background Art

[0002] In a vehicle fuel cell power generation system, in order to ensure that the fuel cell can operate in a harsh environment, the fuel cell is usually integrally placed inside a sealed box for protection against rain and dust. During the storage and operation of the fuel cell system, moisture and hydrogen will accumulate inside the box, which will affect the hydrogen safety and insulation resistance of the system. The fuel cell box is generally provided with a purge inlet, a purge outlet, and a hydrogen concentration sensor. The air compressor in the fuel cell system is used to purge and replace the gas inside the box to remove moisture and hydrogen, and monitor the internal hydrogen concentration.

[0003] The prior art only focuses on the discharge of water vapor and hydrogen inside the box, and the purge method is simple and single, unable to quickly remove liquid water, and unable to quantitatively calculate and analyze the external leakage of hydrogen in the fuel cell. Quantitatively determining the external exposure of hydrogen in the fuel cell is crucial for the safe operation of the system. The purge pipeline usually adopts a direct connection method without a sealing device, and there is a risk of backflow of the tail gas hydrogen into the box when the fuel cell system is shut down emergently.

[0004] The space environment inside the fuel cell box is the direct external environment for the fuel cell to work. The prior art lacks effective control of its environmental parameters, such as temperature, pressure, humidity, etc. Effectively controlling the working environmental parameters of the fuel cell can not only ensure good operating conditions of the fuel cell, but also improve the performance indicators of the fuel cell system. During use, it is necessary to output the electric energy generated by the fuel cell externally. Usually, an external output copper bar is used to lead out the positive and negative copper electrodes of the fuel cell. One end of the output copper bar is fixed on the surface of the sealed box, and the other end is connected and fixed to the copper electrode of the fuel cell. Since the fuel cell is inside the box, it is impossible to quickly detect the loosening of the connection between the copper electrode of the fuel cell and the output copper bar. Under high-current operation, the loosening of the connection between the copper electrode and the output copper bar will bring extremely serious consequences, such as melting of the copper electrode or copper bar due to high temperature, and open fire inside the box. Summary of the Invention

[0005] The present invention provides a fuel cell system, a control method and an automobile, which can solve the technical problems of hydrogen safety risks caused by hydrogen leakage of the fuel cell or hydrogen backflow into the box body from the tail gas, quantitative analysis of hydrogen leakage of the fuel cell, reduction of insulation resistance caused by high humidity, liquid water condensation or coolant leakage inside the box body, and high temperature and melting caused by loose connection between the copper electrode and the output copper busbar. The method provided by the embodiment of the present invention can effectively monitor and regulate parameters such as the temperature, pressure and humidity inside the fuel cell box body, reduce the pressure difference inside and outside the fuel cell, provide a good operating environment for the fuel cell, and improve the performance of the fuel cell system.

[0006] The technical solution provided by the embodiment of the present invention is as follows: On the one hand, a control method for a fuel cell system is provided, including: Obtaining the temperature of the copper electrode, the temperature of the output copper busbar, and the internal environment temperature of the fuel cell box body; Obtaining the temperature rise of the copper electrode and the output copper busbar corresponding to the fuel cell current; Obtaining the theoretically upper limit temperature that the copper electrode and the output copper busbar can reach at the current ambient temperature according to the temperature rise of the copper electrode and the output copper busbar corresponding to the fuel cell current and the internal environment temperature; Calculating a threshold temperature for judging whether the connection between the copper electrode and the output copper busbar is normal according to the theoretically upper limit temperature and the temperature redundancy coefficient; Comparing the actually measured temperatures of the copper electrode and the output copper busbar with the threshold temperature, and when the temperatures of the copper electrode and the output copper busbar are greater than the threshold temperature, determining that the connection between the copper electrode and the output copper busbar is loose; After the fuel cell system is shut down or an emergency shutdown is completed, obtaining the hydrogen concentration inside the fuel cell box body, comparing the hydrogen concentration with the threshold concentration, and when the hydrogen concentration is greater than the threshold concentration, determining that the fuel cell system has a hydrogen leak; After the fuel cell system has a hydrogen leak, obtaining the internal volume of the fuel cell box body, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time, and the hydrogen concentration; Calculating the hydrogen leakage amount of the fuel cell based on the internal volume of the fuel cell box body, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time, and the hydrogen concentration; Controlling the internal gas pressure and moisture of the fuel cell box body based on the hydrogen leakage amount of the fuel cell, and further controlling the normal operation of the fuel cell system.

[0007] In an optional implementation manner, obtaining the theoretically upper limit temperature that the copper electrode and the output copper busbar can reach at the current ambient temperature according to the temperature rise of the copper electrode and the output copper busbar corresponding to the fuel cell current and the internal environment temperature includes: The theoretical upper limit temperature is obtained based on the sum of the internal environmental temperature and the temperature rise of the fuel cell box.

[0008] In an alternative embodiment, a threshold temperature for determining whether the copper electrode and the output copper bus are connected normally is calculated based on the theoretical upper limit temperature and the temperature redundancy coefficient, including: The theoretical upper limit temperature is obtained by multiplying the temperature redundancy coefficient by the theoretical upper limit temperature.

[0009] In an alternative embodiment, the hydrogen leakage amount of the fuel cell is calculated based on the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time, and the hydrogen concentration, including: The hydrogen leakage amount of the fuel cell is obtained according to the following formula: L P = V×η×β / T Where L is the hydrogen leakage amount of the fuel cell, P is the pressure holding pressure of the hydrogen chamber of the fuel cell, V is the internal net volume of the fuel cell box, β is the hydrogen distribution coefficient in the fuel cell box, and T is the pressure holding duration.

[0010] In an alternative embodiment, it further includes: comparing the hydrogen leakage amount of the fuel cell with the hydrogen leakage threshold of the fuel cell; Based on the comparison result, the degree of hydrogen leakage in the anode chamber of the fuel cell is judged, and then whether to perform fault output and alarm prompt is determined.

[0011] In an alternative embodiment, controlling the internal gas pressure and moisture of the fuel cell box based on the hydrogen leakage amount of the fuel cell to control the normal operation of the fuel cell system, including: When the fuel cell system is running, the pressure and temperature of the compressed gas provided by the gas source are controlled based on the hydrogen leakage amount of the fuel cell, and the gas pressure and gas flow parameters inside the fuel cell box are calculated according to the operating condition parameters of the fuel cell; According to the gas pressure and gas flow parameters inside the fuel cell box, the opening ratios of the inlet proportional valve and the outlet proportional valve of the fuel cell box are dynamically adjusted to control the gas pressure and gas flow, and meet the internal and external pressure difference of the fuel cell, the requirements of hydrogen discharge and heat dissipation inside the box.

[0012] In an alternative embodiment, controlling the internal gas pressure and moisture of the fuel cell box based on the hydrogen leakage amount of the fuel cell to control the normal operation of the fuel cell system further includes: Controlling the inlet proportional valve of the fuel cell box, periodically opening or closing the outlet proportional valve of the fuel cell box, and replacing the internal gas of the fuel cell box with a periodic, preset pressure difference, and preset flow rate; When the internal gas of the fuel cell box is replaced periodically with a preset pressure difference and a preset flow rate, the coolant and liquid water inside the fuel cell box are quickly discharged.

[0013] In an optional embodiment, the pressure of the internal gas of the fuel cell box is the difference between the pressure of the cathode cavity in the operating condition parameters of the fuel cell system and the calibrated pressure of the cathode cavity.

[0014] On the other hand, a control system for a fuel cell system is provided, which is controlled by the control method of the fuel cell system described in any one of the above.

[0015] On yet another aspect, a vehicle is provided, which includes the fuel cell control system described above.

[0016] The control method of the fuel cell system provided by the embodiments of the present invention has at least the following beneficial effects: The method provided by the embodiments of the present invention can quickly and accurately identify the connection looseness problem between the fuel cell copper electrode and the output copper busbar in the fuel cell box by measuring and monitoring the temperature of the fuel cell copper electrode and the copper busbar, and prevent serious safety risks such as abnormal high temperature of the copper electrode, electrode melting and open fire caused by connection looseness under large current. It can effectively prevent the interference of hydrogen concentration monitoring and safety risks brought by the backflow of tail gas hydrogen into the fuel cell box, and can quantitatively analyze the external leakage of the fuel cell anode cavity by calculation, evaluate the anode sealing performance of the fuel cell, detect faults in time, and prevent safety risks. It can effectively monitor and regulate the external working environment parameters of the fuel cell, especially the external pressure parameters of the fuel cell, which is beneficial to reducing the external pressure difference of each cavity of the fuel cell, enhancing the sealing performance, reducing the leakage amount, and extending the service life of the fuel cell. It can quickly and effectively discharge the coolant and liquid water inside the box, efficiently dry the inside of the box, reduce humidity, and increase the insulation resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present disclosure will become more apparent. Among them, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0018] Figure 1 It is a schematic flowchart of the control method of the fuel cell system provided by the embodiments of the present invention.

[0019] Figure 2 It is a schematic structural diagram of the fuel cell box provided by the embodiments of the present invention.

[0020] Figure 3 It is a schematic flowchart of the detection of the connection looseness between the fuel cell copper electrode and the copper busbar provided by the embodiments of the present invention.

[0021] Figure 4 Schematic diagram of the detection process for hydrogen leakage in a fuel cell provided by an embodiment of the present invention.

[0022] Figure 5 Schematic diagram of the external environment pressure regulation process for a fuel cell provided by an embodiment of the present invention.

[0023] Figure 6 Schematic diagram of the internal liquid drainage and drying process for the fuel cell box provided by an embodiment of the present invention. Detailed implementation manners

[0024] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be more thorough and complete, and can fully convey the scope of the present disclosure to those skilled in the art.

[0025] As used herein, the term "including" and its variants mean open inclusion, that is, "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an exemplary embodiment" and "an embodiment" mean "at least one exemplary embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. There may also be other explicit and implicit definitions hereinafter.

[0026] Please refer to Figure 1 , the control method for a fuel cell system provided by an embodiment of the present invention includes: Step S1, obtaining the copper electrode temperature, the output copper bar temperature, and the internal environment temperature of the fuel cell box.

[0027] Step S2, obtaining the temperature rise of the copper electrode and the output copper bar corresponding to the fuel cell current.

[0028] Step S3, obtaining the theoretically achievable upper limit temperature of the copper electrode and the output copper bar at the current ambient temperature according to the temperature rise of the copper electrode and the output copper bar corresponding to the fuel cell current and the internal environment temperature; Step S4, calculating the threshold temperature for determining whether the connection of the copper electrode and the output copper bar is normal according to the theoretically achievable upper limit temperature and the temperature redundancy coefficient.

[0029] Step S5, comparing the actually measured copper electrode temperature and output copper bar temperature with the threshold temperature, and when the copper electrode temperature and the output copper bar temperature are greater than the threshold temperature, it is determined that the connection of the copper electrode and the output copper bar is loose.

[0030] Step S6: After the fuel cell system shuts down or completes an emergency shutdown, obtain the hydrogen concentration inside the fuel cell box body, compare the hydrogen concentration with a threshold concentration, and when the hydrogen concentration is greater than the threshold concentration, determine that the fuel cell system has a hydrogen leak.

[0031] Step S7: After the fuel cell system has a hydrogen leak, obtain the internal volume of the fuel cell box body, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time, and the hydrogen concentration.

[0032] Step S8: Calculate the hydrogen leakage amount of the fuel cell based on the internal volume of the fuel cell box body, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time, and the hydrogen concentration.

[0033] Step S9: Control the internal gas pressure and moisture of the fuel cell box body based on the hydrogen leakage amount of the fuel cell, thereby controlling the normal operation of the fuel cell system.

[0034] The control method of the fuel cell system provided by the embodiment of the present invention has the following beneficial effects: The method provided by the embodiment of the present invention can quickly and accurately identify the problem of loose connection between the fuel cell copper electrode and the output copper bar in the fuel cell box body by measuring and monitoring the temperatures of the fuel cell copper electrode and the copper bar, prevent serious safety risks such as abnormal high temperature of the copper electrode, electrode melting, and open fire caused by loose connection under large current. It can effectively prevent the interference of hydrogen concentration monitoring and safety risks brought by the backflow of tail gas hydrogen into the fuel cell box body, can quantitatively analyze the external leakage of the fuel cell anode cavity through calculation, evaluate the anode sealing performance of the fuel cell, discover faults in time, and prevent safety risks. It can effectively monitor and regulate the external working environment parameters of the fuel cell, especially the external pressure parameters of the fuel cell, which is beneficial to reducing the external pressure difference of each cavity of the fuel cell, enhancing the sealing performance, reducing the leakage amount, and extending the service life of the fuel cell. It can quickly and effectively discharge the coolant and liquid water inside the box body, efficiently dry the inside of the box body, reduce the humidity, and increase the insulation resistance.

[0035] In step S1, obtain the copper electrode temperature, the output copper bar temperature, and the internal environment temperature of the fuel cell box body.

[0036] As Figure 2 shown, the fuel cell box body provided by the embodiment of the present invention is internally provided with a copper electrode, a copper bar connection point temperature sensor, a hydrogen concentration sensor, a pressure sensor, and a box body internal temperature sensor, and externally provided with a box body inlet proportional valve, a box body outlet proportional valve, a gas source temperature sensor, etc.

[0037] The temperature sensors at the copper electrode and the copper bus connection point measure the temperatures of the copper electrode and the output copper bus at the connection point. The hydrogen concentration sensor measures the volume concentration of hydrogen gas inside the box body. The pressure sensor measures the gas pressure inside the box body. The temperature sensor measures the ambient temperature inside the box body.

[0038] The proportional valve at the box body inlet controls the gas pipeline entering the box body, and the proportional valve at the box body outlet controls the gas pipeline discharging the gas inside the box body. The gas source temperature sensor measures the temperature of the gas source. The gas source is a compressed gas source, and the pressure and temperature of the compressed gas are controllable and can be provided by the air compressor of the fuel cell system or other device equipment.

[0039] In steps S2 and S3, the temperature rise of the copper electrode and the output copper bus corresponding to the fuel cell current is obtained. According to the temperature rise of the copper electrode and the output copper bus corresponding to the fuel cell current and the internal ambient temperature, the theoretical upper limit temperature that the copper electrode and the output copper bus can reach at the current ambient temperature is obtained; As Figure 3 shown, the copper electrode and the copper bus are connected to the temperature sensors to measure the copper electrode temperature and the copper bus temperature. The temperature sensor inside the fuel cell box measures the internal ambient temperature of the fuel cell box. According to the temperature rise of the copper electrode and the output copper bus corresponding to the fuel cell current, the theoretical upper limit temperature that the copper electrode and the output copper bus can reach at the current ambient temperature is calculated, and based on this, the temperature redundancy coefficient is increased to obtain the threshold temperature for judging whether the connection of the copper electrode and the copper bus is normal.

[0040] When the measured copper electrode temperature or copper bus temperature is greater than the threshold temperature, it is determined that the connection between the copper electrode and the output copper bus is loose, and a fault output and an alarm prompt are given to eliminate the corresponding risk.

[0041] In an optional implementation manner, obtaining the theoretical upper limit temperature that the copper electrode and the output copper bus can reach at the current ambient temperature according to the temperature rise of the copper electrode and the output copper bus corresponding to the fuel cell current and the internal ambient temperature includes: obtaining the theoretical upper limit temperature according to the sum of the internal ambient temperature and the temperature rise of the fuel cell box body.

[0042] In the embodiment of the present invention, the theoretical upper limit temperature = the internal ambient temperature of the fuel cell box body + the temperature rise. Among them, the internal ambient temperature of the fuel cell box body can be measured by the internal temperature sensor, and the temperature rise can be obtained by looking up the data table and engineering practice according to the fuel cell current and the design parameters of the output copper bus.

[0043] In steps S6 and S7, after the fuel cell system shuts down or completes an emergency shutdown, the hydrogen concentration inside the fuel cell box is obtained, and the hydrogen concentration is compared with a threshold concentration. When the hydrogen concentration is greater than the threshold concentration, it is determined that the fuel cell system has a hydrogen leak. After the fuel cell system has a hydrogen leak, the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time, and the hydrogen concentration are obtained.

[0044] After the fuel cell system shutdown is completed or an emergency shutdown occurs, the inlet proportional valve and the outlet proportional valve of the fuel cell box are closed, and the internal space of the fuel cell box is promptly sealed to prevent the tail gas hydrogen from flowing back into the fuel cell box, affecting the judgment of fuel cell hydrogen leakage and the hydrogen concentration alarm inside the box.

[0045] As Figure 4 shown, when the hydrogen concentration in the sealed space of the fuel cell box exceeds the normal threshold concentration, it can be judged that the fuel cell has an abnormal hydrogen leak, and quantitative analysis and calculation of the fuel cell hydrogen leakage are required.

[0046] Open the inlet proportional valve and the outlet proportional valve of the fuel cell box, and use the compressed gas provided by the gas source to discharge the hydrogen inside the fuel cell box until the measured hydrogen concentration value is 0. Close the inlet proportional valve and the outlet proportional valve of the fuel cell box, perform leakage pressure holding on the fuel cell anode circuit for a certain period of time, and measure the current hydrogen concentration inside the fuel cell box. According to the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the pressure holding pressure, the pressure holding time, and the hydrogen concentration, calculate the fuel cell hydrogen leakage amount. Compare the hydrogen leakage amount with the fuel cell hydrogen leakage threshold to judge the severity of the fuel cell anode cavity leakage, and then perform fault output and alarm prompts to eliminate the safety risks brought by the abnormal hydrogen leakage of the fuel cell.

[0047] In an alternative embodiment, calculating the threshold temperature for determining whether the copper electrode and the output copper busbar are connected normally based on the theoretical upper limit temperature and the temperature redundancy coefficient includes: obtaining the theoretical upper limit temperature by multiplying the temperature redundancy coefficient and the theoretical upper limit temperature.

[0048] In an alternative embodiment, calculating the fuel cell hydrogen leakage amount based on the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time, and the hydrogen concentration includes: obtaining the fuel cell hydrogen leakage amount according to the following formula: L P = V×η×β / T where L is the fuel cell hydrogen leakage amount, P is the pressure holding pressure of the fuel cell hydrogen cavity, L PIt is the hydrogen leakage rate of the fuel cell under the pressure maintaining pressure of the fuel cell hydrogen chamber. V is the internal net volume of the fuel cell box, β is the hydrogen distribution coefficient in the fuel cell box, and T is the pressure maintaining duration.

[0049] In an alternative embodiment, it further includes: comparing the hydrogen leakage rate of the fuel cell with the hydrogen leakage threshold of the fuel cell; judging the degree of hydrogen leakage in the anode chamber of the fuel cell based on the comparison result, and further determining whether to perform fault output and alarm prompt.

[0050] In an alternative embodiment, controlling the internal gas pressure and moisture of the fuel cell box based on the hydrogen leakage rate of the fuel cell to further control the normal operation of the fuel cell system includes: When the fuel cell system operates, controlling the pressure and temperature of the compressed gas provided by the gas source based on the hydrogen leakage rate of the fuel cell, and calculating the internal gas pressure and gas flow parameters of the fuel cell box according to the operating condition parameters of the fuel cell.

[0051] Dynamically adjusting the opening ratios of the inlet proportional valve and the outlet proportional valve of the fuel cell box according to the internal gas pressure and gas flow parameters of the fuel cell box to control the gas pressure and gas flow, and meet the internal and external pressure differences of the fuel cell, the requirements for discharging hydrogen inside the box and heat dissipation.

[0052] Furthermore, regulating the internal gas pressure of the fuel cell box, that is, the external environment pressure of the fuel cell, to ensure that the anode chamber, cathode chamber and cooling chamber of the fuel cell maintain a relatively low pressure difference with the environment pressure during operation, reduce the leakage degree of each chamber to the outside, enhance the sealing effect and extend the service life. As Figure 5 shown, when the fuel cell system operates, controlling the pressure and temperature of the compressed gas provided by the gas source, calculating the internal gas pressure and gas flow parameters of the box according to the operating condition parameters of the fuel cell, and dynamically adjusting the opening ratios of the inlet proportional valve and the outlet proportional valve of the fuel cell box to control the pressure and flow, and meet the internal and external pressure differences of the fuel cell, the requirements for discharging hydrogen inside the box and heat dissipation.

[0053] In an alternative embodiment, controlling the internal gas pressure and moisture of the fuel cell box based on the hydrogen leakage rate of the fuel cell to further control the normal operation of the fuel cell system further includes: Controlling the inlet proportional valve of the fuel cell box, periodically opening or closing the outlet proportional valve of the fuel cell box, and replacing the internal gas of the fuel cell box with a periodic, preset pressure difference and preset flow rate; quickly discharging the coolant and liquid water inside the fuel cell box when the internal gas of the fuel cell box is replaced with a periodic, preset pressure difference and preset flow rate.

[0054] Further, the moisture inside the fuel cell box is regulated to quickly discharge and dry the liquid water inside the fuel cell box. The condensation of water vapor or the leakage of the cooling cavity inside the fuel cell box will cause an increase in humidity and liquid accumulation inside the shell, posing a risk of reducing the insulation resistance of the fuel cell, which may trigger an electrical high-voltage safety alarm and affect the normal operation of the system. As Figure 6 shown, the gas source provides compressed gas with a relatively high temperature, and the gas source temperature sensor measures the temperature of the gas source gas. When the temperature of the compressed gas reaches a certain threshold, the high-pressure and high-temperature gas is used to discharge and dry the liquid water inside the fuel cell box. The inlet proportional valve of the box is opened, and the outlet proportional valve of the fuel cell box is periodically opened and closed to control the pressure inside the fuel cell box to reach the threshold pressure, and the gas inside the fuel cell box is replaced periodically, with a high pressure difference and a large flow rate. The periodic discharge of the gas with a high pressure difference, high temperature, and large flow rate can quickly discharge the coolant and liquid water inside the fuel cell box, efficiently dry the inside of the fuel cell box, and improve the insulation resistance.

[0055] In an alternative embodiment, the pressure of the gas inside the fuel cell box is the difference between the pressure of the cathode cavity and the calibrated pressure of the cathode cavity in the operating condition parameters of the fuel cell system.

[0056] On the other hand, a control system for a fuel cell system is provided, which is controlled by the control method of the fuel cell system described in any one of the above.

[0057] On yet another aspect, a vehicle is provided, which includes the fuel cell control system described above.

[0058] Embodiment 1 Monitoring and judging the looseness of the connection between the copper electrode and the output copper busbar.

[0059] During a certain operation of the fuel cell system, the monitoring of the looseness of the connection between the copper electrode and the output copper busbar is carried out according to the Figure 3 flow shown: Step 1: The temperature of the copper electrode is read as 200°C, the temperature of the copper busbar is 180°C, and the ambient temperature inside the box is 60°C.

[0060] Step 2: The output current of the fuel cell is 500 A at this time. The theoretical temperature rise of the copper electrode under a current of 500 A is 60°C, and the theoretical temperature rise of the output copper busbar under a current of 500 A is 70°C.

[0061] Step 3: The safety threshold temperature of the copper electrode under a current of 500 A is (60 + 60) * 1.2 = 144°C, and the safety threshold temperature of the output copper busbar under a current of 500 A is (60 + 70) * 1.2 = 156°C.

[0062] Step 4: Since the current temperature of the copper electrode, 200°C, is greater than the current safety threshold temperature of the copper electrode, 144°C, and the current temperature of the output copper bar, 180°C, is greater than the current safety threshold temperature of the output copper bar, 156°C. It can be determined that the connection between the copper electrode and the output copper bar is loose, and an alarm prompt and fault output are made.

[0063] Step 5: According to the alarm prompt, after inspecting and troubleshooting inside the fuel cell box, it is confirmed that there is a loose connection, and the risk is promptly eliminated.

[0064] Example 2 Quantitative analysis and calculation of hydrogen leakage in a fuel cell.

[0065] During the operation of a certain fuel cell system, the hydrogen volume concentration inside the fuel cell box is detected to be 50000 PPM, indicating a risk of abnormal hydrogen leakage. Quantitative analysis and calculation of hydrogen leakage in the fuel cell are required. Operate and make judgments according to the Figure 3 shown process Step 1: Open the inlet proportional valve of the box to 100%, open the outlet proportional valve of the box to 100%, and the gas source flow rate is 50 L / min to replace the gas inside the fuel cell box until the hydrogen concentration inside the fuel cell box is 0.

[0066] Step 2: Close the inlet proportional valve of the fuel cell box and the outlet proportional valve of the fuel cell box. Control the pressure inside the anode cavity of the fuel cell to remain at 50 kPag for 5 minutes, and read the hydrogen concentration inside the fuel cell box at this time as 45000 PPM.

[0067] Step 3: According to the net volume V of the fuel cell box, the hydrogen distribution coefficient β inside the fuel cell box, the pressure holding pressure P, the hydrogen concentration η inside the fuel cell box, and the pressure holding duration T, calculate that the current leakage rate of the anode cavity of the fuel cell is 10 mL / min.

[0068] Step 4: Under the pressure holding of 50 kPag in the anode cavity of the fuel cell, the safety leakage threshold is 0.5 mL / min. The calculated value of 10 mL / min is much greater than the safety threshold of 0.5 mL / min, indicating that there is a serious leakage in the anode cavity. An alarm is given.

[0069] Step 5: According to the alarm reminder, troubleshoot the fault. It is confirmed that there is a seal failure somewhere, and the safety risk is eliminated.

[0070] The embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A control method for a fuel cell system, characterized in that: include: Obtain the copper electrode temperature, output copper busbar temperature, and fuel cell box internal ambient temperature; Obtain the temperature rise of the copper electrode and the output copper bar corresponding to the fuel cell current; Obtaining the theoretical upper limit temperature that the copper electrode and the output copper busbar can reach at the current ambient temperature according to the temperature rise temperature of the copper electrode and the output copper busbar corresponding to the fuel cell current and the internal ambient temperature; The threshold temperature for judging whether the copper electrode and the output copper busbar are connected normally is calculated based on the theoretical upper limit temperature and the temperature redundancy coefficient; Comparing the actually measured copper electrode temperature and output copper busbar temperature with the threshold temperature, and determining that the connection between the copper electrode and the output copper busbar is loose when the copper electrode temperature and the output copper busbar temperature are greater than the threshold temperature; After the fuel cell system is shut down or an emergency shutdown is completed, the hydrogen concentration inside the fuel cell box is obtained, and the hydrogen concentration is compared with a threshold concentration. When the hydrogen concentration is greater than the threshold concentration, it is determined that a hydrogen leak occurs in the fuel cell system; After hydrogen leakage occurs in the fuel cell system, obtaining the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the holding pressure, the holding time and the hydrogen concentration; The hydrogen leakage of the fuel cell is calculated based on the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the holding pressure, the holding time and the hydrogen concentration; Based on the hydrogen leakage of the fuel cell, the gas pressure and moisture inside the fuel cell box are controlled to thereby control the normal operation of the fuel cell system.

2. The control method of the fuel cell system according to claim 1, characterized in that: The theoretical upper limit temperature that the copper electrode and the output copper bus can reach at the current ambient temperature is obtained according to the temperature rise temperature of the copper electrode and the output copper bus corresponding to the fuel cell current and the internal ambient temperature, including: The theoretical upper limit temperature is obtained according to the sum of the internal ambient temperature and the temperature rise temperature of the fuel cell box.

3. The control method of the fuel cell system according to claim 1, characterized in that: The threshold temperature for judging whether the copper electrode and the output copper busbar are connected normally is calculated based on the theoretical upper limit temperature and the temperature redundancy coefficient, including: The theoretical upper limit temperature is obtained according to the product of the temperature redundancy coefficient and the theoretical upper limit temperature.

4. The control method of the fuel cell system according to claim 1, characterized in that: The hydrogen leakage of the fuel cell is calculated based on the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the holding pressure, the holding time and the hydrogen concentration, including: obtaining the hydrogen leakage of the fuel cell according to the following formula: L P = V×η×β / T Wherein, L is the hydrogen leakage of the fuel cell, P is the pressure holding pressure of the hydrogen cavity of the fuel cell, V is the internal net volume of the fuel cell box, β is the hydrogen distribution coefficient in the fuel cell box, and T is the pressure holding duration.

5. The control method of the fuel cell system according to claim 1, characterized in that: Also includes: comparing the fuel cell hydrogen leakage amount with the fuel cell hydrogen leakage threshold; The extent of hydrogen leakage in the anode cavity of the fuel cell is judged based on the comparison result, and then it is determined whether to perform a fault output and an alarm prompt.

6. The control method of the fuel cell system according to claim 1, characterized in that: Controlling the gas pressure and moisture inside the fuel cell box based on the hydrogen leakage of the fuel cell and thus controlling the normal operation of the fuel cell system includes: When the fuel cell system is running, the pressure and temperature of the compressed gas provided by the gas source are controlled based on the hydrogen leakage of the fuel cell, and the gas pressure and gas flow parameters inside the fuel cell box are calculated according to the operating condition parameters of the fuel cell; The opening ratio of the inlet proportional valve and the outlet proportional valve of the fuel cell box is dynamically adjusted according to the gas pressure and gas flow parameters inside the fuel cell box, and the gas pressure and gas flow are controlled to meet the pressure difference between the inside and outside of the fuel cell, the hydrogen discharge and heat dissipation requirements inside the box.

7. The control method of the fuel cell system according to claim 1, characterized in that: Based on the hydrogen leakage of the fuel cell, the gas pressure and moisture inside the fuel cell box are controlled to thereby control the normal operation of the fuel cell system, further comprising: Controlling the inlet proportional valve of the fuel cell box, periodically opening or closing the outlet proportional valve of the fuel cell box, and replacing the internal gas of the fuel cell box periodically, with a preset pressure difference and a preset flow rate; When the internal gas of the fuel cell box is replaced periodically, with a preset pressure difference and a preset flow rate, the coolant and liquid water inside the fuel cell box are quickly discharged.

8. The control method of the fuel cell system according to claim 1, characterized in that: The gas pressure inside the fuel cell box is the difference between the pressure of the cathode cavity in the operating condition parameters of the fuel cell system and the calibrated pressure of the cathode cavity.

9. A control system for a fuel cell system, characterized in that: The fuel cell system is controlled by the control method according to any one of claims 1 to 8.

10. An automobile, characterized in that: The vehicle includes the fuel cell control system according to claim 9.

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