Fuel cell system, control method and vehicle

Abstract

The present invention provides a fuel cell system, a control method and an automobile, belonging to the technical field of fuel cell. The fuel cell system includes: obtaining the temperature of the copper electrode, the temperature of the output busbar, and the internal environment temperature of the fuel cell box; obtaining the temperature rise of the copper electrode and the output busbar corresponding to the fuel cell current, and obtaining the theoretical upper limit temperature that the copper electrode and the output busbar can reach at the current ambient temperature; calculating a threshold temperature for judging whether the connection of the copper electrode and the output busbar is normal according to the theoretical upper limit temperature and the temperature redundancy coefficient; after the fuel cell system shuts down or completes an emergency shutdown, obtaining the hydrogen concentration inside the fuel cell box to determine 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, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time and the hydrogen concentration to calculate the hydrogen leakage amount of the fuel cell, and controlling the normal operation of the fuel cell system.

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 displace 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. It cannot quickly discharge liquid water and cannot quantitatively calculate and analyze the external leakage of hydrogen in the fuel cell. Quantitatively determining the external leakage 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 tail gas hydrogen backflow 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 index of the fuel cell system. During use, the electric energy generated by the fuel cell needs to be output 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, etc. Summary of the Invention

[0005] The present invention provides a fuel cell system, a control method and an automobile, which can solve the hydrogen safety risks caused by hydrogen leakage of the fuel cell or hydrogen backflow into the box body from the tail gas, the problem of quantitative analysis of hydrogen leakage of the fuel cell, the problem of reduced insulation resistance caused by high humidity, liquid water condensation or coolant leakage inside the box body, and the technical problems of 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 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:

[0007] On the one hand, a control method for a fuel cell system is provided, including:

[0008] Obtain the copper electrode temperature, the output copper busbar temperature, and the internal environment temperature of the fuel cell box body;

[0009] Obtain the temperature rise of the copper electrode and the output copper busbar corresponding to the fuel cell current;

[0010] 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, obtain the theoretical upper limit temperature that the copper electrode and the output copper busbar can reach at the current ambient temperature;

[0011] According to the theoretical upper limit temperature and the temperature redundancy coefficient, calculate the threshold temperature for judging whether the connection between the copper electrode and the output copper busbar is normal;

[0012] Compare the actually measured copper electrode temperature and output copper busbar temperature with the threshold temperature. When the copper electrode temperature and the output copper busbar temperature are greater than the threshold temperature, it is determined that the connection between the copper electrode and the output copper busbar is loose;

[0013] 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 the threshold concentration, and when the hydrogen concentration is greater than the threshold concentration, determine that the fuel cell system has a hydrogen leak;

[0014] 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;

[0015] 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, calculate the hydrogen leakage amount of the fuel cell;

[0016] Control the internal gas pressure and moisture of the fuel cell box based on the hydrogen leakage amount of the fuel cell, and then control the normal operation of the fuel cell system.

[0017] In an alternative embodiment, 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 copper electrode, the temperature rise of the output copper bus corresponding to the fuel cell current, and the internal ambient temperature includes:

[0018] Obtain the theoretical upper limit temperature according to the sum of the internal ambient temperature and the temperature rise of the fuel cell box.

[0019] In an alternative embodiment, calculating the threshold temperature for judging whether the connection of the copper electrode and the output copper bus is normal according to the theoretical upper limit temperature and the temperature redundancy coefficient includes:

[0020] Obtain the theoretical upper limit temperature according to the product of the temperature redundancy coefficient and the theoretical upper limit temperature.

[0021] In an alternative embodiment, calculating the hydrogen leakage amount of the fuel cell 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 hydrogen leakage amount of the fuel cell according to the following formula:

[0022] L P = V×η×β / T

[0023] Wherein, 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.

[0024] 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;

[0025] Based on the comparison result, judge the degree of hydrogen leakage in the anode chamber of the fuel cell, and then determine whether to perform fault output and alarm prompt.

[0026] 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, and then controlling the normal operation of the fuel cell system includes:

[0027] When the fuel cell system is running, control the pressure and temperature of the compressed gas provided by the gas source based on the hydrogen leakage amount of the fuel cell, and calculate the gas pressure and gas flow parameters inside the fuel cell box according to the fuel cell operating condition parameters;

[0028] Dynamically adjust the opening ratios of the inlet proportional valve and the outlet proportional valve of the fuel cell box according to the gas pressure and gas flow parameters inside the fuel cell box to control the gas pressure and gas flow, so as to meet the pressure difference between the inside and outside of the fuel cell, and the requirements for hydrogen discharge and heat dissipation inside the box.

[0029] In an alternative embodiment, based on the hydrogen leakage amount of the fuel cell, control the gas pressure and moisture inside the fuel cell box, and further control the normal operation of the fuel cell system, further including:

[0030] Control the inlet proportional valve of the fuel cell box, periodically open or close the outlet proportional valve of the fuel cell box, and replace the internal gas of the fuel cell box with a periodic, preset pressure difference, and preset flow rate;

[0031] When the internal gas of the fuel cell box is replaced with a periodic, preset pressure difference, and preset flow rate, quickly discharge the coolant and liquid water inside the fuel cell box.

[0032] In an alternative embodiment, 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.

[0033] 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.

[0034] On yet another aspect, an automobile is provided, and the automobile includes the above-mentioned fuel cell control system.

[0035] The control method of the fuel cell system provided by the embodiments of the present invention has at least the following beneficial effects:

[0036] 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 row in the fuel cell box by measuring and monitoring the temperatures of the fuel cell copper electrode and the copper row, 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 caused 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 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 parameter of the fuel cell, which is beneficial to reducing the pressure difference between each cavity of the fuel cell and the outside, 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 the humidity, and increase the insulation resistance. Description of the Drawings

[0037] The above and other objects, features, and advantages of the present disclosure will become more apparent by describing the exemplary embodiments of the present disclosure in more detail with reference to the accompanying drawings, wherein, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0038] Figure 1 It is a schematic flow chart of the control method of the fuel cell system provided by the embodiment of the present invention.

[0039] Figure 2 It is a schematic diagram of the fuel cell box structure provided by the embodiment of the present invention.

[0040] Figure 3 It is a schematic flow chart of the detection process for loose connection between the copper electrode and the copper busbar of the fuel cell provided by the embodiment of the present invention.

[0041] Figure 4 It is a schematic flow chart of the detection process for the hydrogen leakage amount of the fuel cell provided by the embodiment of the present invention.

[0042] Figure 5 It is a schematic flow chart of the external environment pressure regulation of the fuel cell provided by the embodiment of the present invention.

[0043] Figure 6 It is a schematic flow chart of the internal liquid drainage and drying process of the fuel cell box provided by the embodiment of the present invention. Detailed implementation manners

[0044] 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 to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0045] The term "including" and its variations used herein 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 be other explicit and implicit definitions hereinafter.

[0046] Please refer to Figure 1 , the control method of the fuel cell system provided by the embodiment of the present invention includes:

[0047] Step S1, obtain the copper electrode temperature, the output copper busbar temperature, and the internal environment temperature of the fuel cell box.

[0048] Step S2: Obtain the temperature rise of the copper electrode and the output copper busbar corresponding to the fuel cell current.

[0049] Step S3: Obtain the theoretically achievable upper limit temperature of the copper electrode and the output copper busbar at the current ambient temperature based on the temperature rise of the copper electrode and the output copper busbar corresponding to the fuel cell current and the internal ambient temperature.

[0050] Step S4: Calculate the threshold temperature for determining whether the connection of the copper electrode and the output copper busbar is normal based on the theoretically achievable upper limit temperature and the temperature redundancy coefficient.

[0051] Step S5: Compare the actually measured temperatures of the copper electrode and the output copper busbar with the threshold temperature. When the temperatures of the copper electrode and the output copper busbar are greater than the threshold temperature, it is determined that the connection of the copper electrode and the output copper busbar is loose.

[0052] Step S6: After the fuel cell system shuts down or completes an emergency shutdown, obtain the hydrogen concentration inside the fuel cell box, compare the hydrogen concentration with the threshold concentration, and when the hydrogen concentration is greater than the threshold concentration, it is determined that the fuel cell system has a hydrogen leak.

[0053] Step S7: After the fuel cell system has a hydrogen leak, obtain the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the holding pressure, the pressure holding time, and the hydrogen concentration.

[0054] Step S8: Calculate the hydrogen leakage amount of the fuel cell 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.

[0055] Step S9: Control the internal gas pressure and moisture of the fuel cell box based on the hydrogen leakage amount of the fuel cell, thereby controlling the normal operation of the fuel cell system.

[0056] The control method of the fuel cell system provided by the embodiment of the present invention has the following beneficial effects:

[0057] The method provided by the embodiment of the present invention can quickly and accurately identify the connection looseness problem between the copper electrode and the output copper busbar of the fuel cell in the fuel cell box by measuring and monitoring the temperatures of the copper electrode and the copper busbar of the fuel cell, 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 interior of the fuel cell box, can quantitatively analyze the external leakage of the anode cavity of the fuel cell through 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 parameter 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 prolonging the service life of the fuel cell. It can quickly and effectively drain the coolant and liquid water inside the box, efficiently dry the inside of the box, reduce the humidity, and increase the insulation resistance.

[0058] In step S1, the temperature of the copper electrode, the temperature of the output copper busbar, and the internal environment temperature of the fuel cell box are obtained.

[0059] As Figure 2 shown, inside the fuel cell box provided by the embodiment of the present invention, there are a copper electrode, a temperature sensor for the copper busbar connection point, a hydrogen concentration sensor, a pressure sensor, and a temperature sensor inside the box. Outside the box, there are a box inlet proportional valve, a box outlet proportional valve, a gas source temperature sensor, etc.

[0060] The temperature sensor for the copper electrode and the copper busbar connection point measures the temperatures of the copper electrode and the output copper busbar at the connection point. The hydrogen concentration sensor measures the volume concentration of hydrogen gas inside the box. The pressure sensor measures the gas pressure inside the box. The temperature sensor measures the internal environment temperature of the box.

[0061] The box inlet proportional valve controls the gas pipeline entering the inside of the box. The box outlet proportional valve controls the gas pipeline discharging the inside of the box. 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 generated and provided by the air compressor of the fuel cell system or other device equipment.

[0062] In steps S2 and S3, the temperature rise temperatures of the copper electrode and the output copper busbar corresponding to the fuel cell current are obtained. According to the temperature rise temperatures of the copper electrode and the output copper busbar corresponding to the fuel cell current and the internal environment temperature, the theoretical upper limit temperatures that the copper electrode and the output copper busbar can reach at the current ambient temperature are obtained;

[0063] As Figure 3As shown, the copper electrode and the copper busbar are connected to a temperature sensor to measure the temperature of the copper electrode and the copper busbar, and 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 copper busbar corresponding to the fuel cell current, the theoretical upper limit temperature that the copper electrode and the copper busbar can reach at the current ambient temperature is calculated, and a temperature redundancy coefficient is added accordingly to obtain the threshold temperature for judging whether the connection of the copper electrode and the copper busbar is normal.

[0064] When the measured temperature of the copper electrode or the copper busbar is greater than the threshold temperature, it is determined that the connection between the copper electrode and the output copper busbar is loose, and a fault output and an alarm prompt are given to eliminate the corresponding risk.

[0065] In an optional implementation manner, 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 of the copper electrode and the output copper busbar 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.

[0066] In the embodiment of the present invention, the theoretical upper limit temperature = the internal ambient temperature of the fuel cell box + the temperature rise. Among them, the internal ambient temperature of the fuel cell box can be measured by an internal temperature sensor, and the temperature rise can be obtained by looking up data tables and engineering practices based on the fuel cell current and the design parameters of the output copper busbar.

[0067] 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 the 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.

[0068] After the fuel cell system shuts down or completes an emergency shutdown, 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 sealed in time to prevent the tail gas hydrogen from flowing back into the fuel cell box, affecting the judgment of fuel cell hydrogen leakage and the alarm of the hydrogen concentration inside the box.

[0069] 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 determined that the fuel cell has an abnormal hydrogen leak, and quantitative analysis and calculation of the fuel cell hydrogen leak need to be carried out.

[0070] Open the inlet proportional valve and the outlet proportional valve of the fuel cell box. Utilize 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, keep the leakage pressure of the fuel cell anode circuit for a certain period of time, and measure the current hydrogen concentration inside the fuel cell box. Calculate the hydrogen leakage amount of the fuel cell according to the internal volume of the fuel cell box, the hydrogen volume distribution coefficient, the pressure holding value, the pressure holding time, and the hydrogen concentration. Compare the hydrogen leakage amount with the hydrogen leakage threshold of the fuel cell to judge the severity of the leakage of the fuel cell anode cavity, and then perform fault output and alarm prompts to eliminate the safety risks brought by abnormal hydrogen leakage of the fuel cell.

[0071] In an alternative embodiment, calculating a threshold temperature for determining whether the copper electrode and the output copper bus are connected normally according to the theoretical upper limit temperature and the temperature redundancy coefficient includes: obtaining the theoretical upper limit temperature according to the product of the temperature redundancy coefficient and the theoretical upper limit temperature.

[0072] In an alternative embodiment, calculating the hydrogen leakage amount of the fuel cell 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 hydrogen leakage amount of the fuel cell according to the following formula:

[0073] L P = V×η×β / T

[0074] Wherein, L is the hydrogen leakage amount of the fuel cell, P is the pressure holding value of the fuel cell hydrogen cavity, and L P is the hydrogen leakage amount of the fuel cell under the pressure holding value of the fuel cell hydrogen cavity. V is the internal net volume of the fuel cell box, β is the hydrogen distribution coefficient inside the fuel cell box, and T is the pressure holding duration.

[0075] 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; judging the degree of hydrogen leakage in the anode cavity of the fuel cell based on the comparison result, and then determining whether to perform fault output and alarm prompts.

[0076] 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 includes:

[0077] When the fuel cell system is operating, controlling the pressure and temperature of the compressed gas provided by the gas source based on the hydrogen leakage amount of the fuel cell, and calculating the gas pressure and gas flow parameters inside the fuel cell box according to the operating condition parameters of the fuel cell.

[0078] Dynamically adjust the opening ratios of the inlet proportional valve and the outlet proportional valve of the fuel cell box according to the gas pressure and gas flow parameters inside the fuel cell box, control the gas pressure and gas flow rate, and meet the pressure difference inside and outside the fuel cell, as well as the requirements for hydrogen discharge and heat dissipation inside the box.

[0079] Furthermore, regulate the gas pressure inside the fuel cell box, that is, the external environmental pressure of the fuel cell, to ensure that the anode chamber, cathode chamber, and cooling chamber maintain a relatively low pressure difference with the ambient pressure during the operation of the fuel cell, reduce the degree of external leakage of each chamber, enhance the sealing effect, and extend the service life. As Figure 5 shown, when the fuel cell system is operating, control the pressure and temperature of the compressed gas provided by the gas source. According to the operating condition parameters of the fuel cell, calculate the gas pressure and gas flow rate parameters inside the box, and dynamically adjust the opening ratios of the inlet proportional valve and the outlet proportional valve of the fuel cell box to control the pressure and flow rate, and meet the pressure difference inside and outside the fuel cell, as well as the requirements for hydrogen discharge and heat dissipation inside the box.

[0080] In an alternative embodiment, control the gas pressure and moisture inside the fuel cell box based on the hydrogen leakage amount of the fuel cell, and further control the normal operation of the fuel cell system, further including:

[0081] Control the inlet proportional valve of the fuel cell box, periodically open or close the outlet proportional valve of the fuel cell box, and replace 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 with a periodic, preset pressure difference, and preset flow rate, quickly discharge the coolant and liquid water inside the fuel cell box.

[0082] Furthermore, regulate the moisture inside the fuel cell box and quickly discharge and dry the liquid water inside the fuel cell box. The condensation of water vapor inside the fuel cell box or the leakage of the cooling chamber will cause an increase in humidity and liquid accumulation inside the housing, posing a risk of reducing the insulation resistance of the fuel cell, and further triggering an electrical high-voltage safety alarm, affecting the normal operation of the system. As Figure 6 shown, the gas source provides compressed gas, and the compressed gas has a relatively high temperature. The gas source temperature sensor measures the temperature of the gas source gas. When the temperature of the compressed gas reaches a certain threshold, use the high-pressure and high-temperature gas to perform the operation of discharging and drying the liquid water inside the fuel cell box. Open the inlet proportional valve of the box, periodically open and close the outlet proportional valve of the fuel cell box, control the internal pressure of the fuel cell box to obtain the threshold pressure, and replace the internal gas of the fuel cell box with a periodic, high pressure difference, and large flow rate. The periodic gas discharge 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 increase the insulation resistance.

[0083] In an alternative embodiment, the internal gas pressure of the fuel cell box is the difference between the pressure of the cathode cavity and the calibrated pressure of the cathode cavity among the operating condition parameters of the fuel cell system.

[0084] 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.

[0085] On yet another aspect, a vehicle is provided, which includes the fuel cell control system described above.

[0086] Example 1

[0087] Monitoring and judging the looseness of the connection between the copper electrode and the output copper busbar.

[0088] During a certain operation of the fuel cell system, according to Figure 3 the shown process, the connection looseness of the copper electrode and the output copper busbar is monitored:

[0089] Step 1: The temperature of the copper electrode is read as 200 °C, the temperature of the copper busbar is 180 °C, and the internal environment temperature of the box is 60 °C.

[0090] Step 2: The output current of the fuel cell at this time is 500 A. The theoretical temperature rise of the copper electrode under 500 A current is 60 °C, and the theoretical temperature rise of the output copper busbar under 500 A current is 70 °C.

[0091] Step 3: The safety threshold temperature of the copper electrode under 500 A current is (60 + 60) * 1.2 = 144 °C, and the safety threshold temperature of the output copper busbar under 500 A current is (60 + 70) * 1.2 = 156 °C.

[0092] 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 busbar, 180 °C, is greater than the current safety threshold temperature of the output copper busbar, 156 °C. It can be judged that the connection between the copper electrode and the output copper busbar is loose, and an alarm prompt and a fault output are made.

[0093] Step 5: According to the alarm prompt, after detecting and troubleshooting the inside of the fuel cell box, it is confirmed that there is a connection looseness phenomenon, and the risk is eliminated in time.

[0094] Example 2 Quantitative analysis and calculation of fuel cell hydrogen leakage.

[0095] During a certain operation of the fuel cell system, the hydrogen volume concentration in the fuel cell box is detected to be 50000 PPM, and there is a risk of abnormal hydrogen leakage. It is necessary to conduct a quantitative analysis and calculation of the fuel cell hydrogen leakage. According to Figure 3 the shown process, the operation and judgment are carried out

[0096] Step 1: Open the inlet proportional valve of the fuel cell box to 100%, open the outlet proportional valve of the fuel cell box to 100%, and set the gas source flow rate to 50 L / min to replace the gas in the fuel cell box until the hydrogen concentration in the fuel cell box is 0.

[0097] 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 in the anode cavity of the fuel cell to maintain 50 kPag for 5 minutes, and read the hydrogen concentration in the fuel cell box at this time, which is 45000 PPM.

[0098] Step 3: According to the net volume V of the fuel cell box, the hydrogen distribution coefficient β in the fuel cell box, the pressure holding pressure P, the hydrogen concentration η in 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.

[0099] 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.

[0100] Step 5: According to the alarm reminder, troubleshoot the problem. It is confirmed that there is a seal failure somewhere, and the safety risk is eliminated.

[0101] The above has described the embodiments of the present disclosure. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field 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 improvements to the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the embodiments disclosed herein.

Claims

1. A control method for a fuel cell system, characterized in that, 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; Obtaining the temperature rise of the copper electrode and the output copper busbar corresponding to the fuel cell current; Obtaining the theoretically achievable upper limit temperature of the copper electrode and the output copper busbar at the current ambient temperature based on 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 determining whether the connection of the copper electrode and the output copper busbar is normal based on the theoretically achievable upper limit temperature and a temperature redundancy coefficient; Comparing the actually measured temperatures of the copper electrode and the output copper busbar with the threshold temperature, and determining that the connection of the copper electrode and the output copper busbar is loose when the temperatures of the copper electrode and the output copper busbar are greater than the threshold temperature; After the fuel cell system shuts down or completes an emergency shutdown, obtaining the hydrogen concentration inside the fuel cell box, comparing the hydrogen concentration with a threshold concentration, and determining that the fuel cell system has a hydrogen leak when the hydrogen concentration is greater than the threshold concentration; After the fuel cell system has a hydrogen leak, obtaining the internal volume of the fuel cell box, 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, 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 based on the hydrogen leakage amount of the fuel cell, thereby controlling the normal operation of the fuel cell system.

2. The control method of the fuel cell system according to claim 1, characterized in that Obtaining the theoretically achievable upper limit temperature of the copper electrode and the output copper busbar at the current ambient temperature based on the temperature rise of the copper electrode and the output copper busbar corresponding to the fuel cell current and the internal environment temperature, including: Obtaining the theoretically achievable upper limit temperature by summing the internal environment temperature and the temperature rise of the fuel cell box.

3. The control method of the fuel cell system according to claim 1, characterized in that, Calculating a threshold temperature for determining whether the connection of the copper electrode and the output copper busbar is normal based on the theoretically achievable upper limit temperature and a temperature redundancy coefficient, including: Obtaining the threshold temperature by multiplying the temperature redundancy coefficient and the theoretically achievable upper limit temperature.

4. The control method of the fuel cell system according to claim 1, characterized in that Calculating the hydrogen leakage amount of the fuel cell 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: obtaining the hydrogen leakage amount of the fuel cell 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.

5. The control method of the fuel cell system according to claim 1, characterized in that Also including: Comparing the hydrogen leakage amount 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 then determining 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 internal gas pressure and moisture of the fuel cell box based on the hydrogen leakage amount of the fuel cell, thereby controlling the normal operation of the fuel cell system, including: When the fuel cell system operates, 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, so as to meet the pressure difference inside and outside the fuel cell, and the requirements for hydrogen discharge and heat dissipation inside the box.

7. The control method of the fuel cell system according to claim 1, characterized in that, Based on the hydrogen leakage amount of the fuel cell, the gas pressure and moisture inside the fuel cell box are controlled to further control the normal operation of the fuel cell system, and it 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 with a periodic, preset pressure difference, and 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 and the calibrated pressure of the cathode cavity in the operating condition parameters of the fuel cell system.

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

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

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