CN115395053A - A purging system and purging method for a fuel cell system - Google Patents

Abstract

The invention discloses a purging system and a purging method of a fuel cell system. The purge system of the present invention comprises: the device comprises a battery pile, an air device, a hydrogen device, a purging device and a discharging device. The purging method of the present invention is based on the purging system. The air is introduced into the battery system through the air compression assembly for use, the source is rich, the cost is low, and the air with high nitrogen content is subjected to deoxidation treatment through the deoxidation bottle, so that a purging air source is obtained, and a nitrogen storage system does not need to be additionally carried. And the nitrogen purging is adopted, so that the influence on the cathode and the anode of the battery is small. The tail hydrogen discharge of the hydrogen device can be recycled through the ejector and the hydrogen circulating pump, and can also be used as a reducing agent to carry out reduction treatment on a deoxidizer in the deoxidizer bottle.

Description

A purging system and purging method for a fuel cell system

technical field

The invention relates to the technical field of fuel cells, in particular to a purging system of a fuel cell system and a purging method thereof.

Background technique

Proton exchange membrane fuel cell, referred to as fuel cell, its purging is mainly to clean up the liquid water or water vapor generated during its working process, to avoid the solidification of excess liquid water or water vapor remaining in the bipolar plate and membrane electrode, which will cause damage to the stack permanent damage. The purging of fuel cells is often accompanied by the start and stop of fuel cells, and the performance of the stack during start and stop directly affects the reliability of fuel cells, so the quality of fuel cell purging is an important factor in considering the reliability of fuel cells .

In the prior art, there are mainly the following three ways of purging the fuel cell. One is to purge the anode with anode hydrogen and the cathode with cathode air. This purging method has high requirements for control and calibration. If large flow control is used, a high potential will be formed at the cathode, making the carbon-based substrate on the cathode catalytic layer more likely to undergo oxidation reaction with oxygen or water, causing the catalyst to condense and deteriorating the electric potential. Heap performance; if small flow control is adopted, the start-stop time of the system will be prolonged. Second, the cathode and anode are purged with anode hydrogen. This purging method has the risk of mixing the anode hydrogen gas with the cathode air, which will increase the risk of counter-electrode of the stack, does not take advantage of the safety of the fuel cell, and will also reduce the overall utilization of the fuel cell. The third is to purge the anode and cathode with nitrogen. The disadvantage of this purging method is mainly due to the need for an external nitrogen storage system to obtain a nitrogen source, which is not conducive to the development trend of fuel cell integration.

Contents of the invention

The purpose of the present invention is to provide a purging system for a fuel cell system to solve one or more technical problems in the prior art, and at least provide a beneficial option or create conditions.

The technical solution adopted for solving the above-mentioned technical problems:

A purging system for a fuel cell system, comprising: a battery stack, an air device, a hydrogen device, a purging device and an exhaust device;

The battery stack has an air inlet, an air outlet, a hydrogen inlet and a hydrogen outlet; the air device includes: an air compressor assembly and a humidifier; the hydrogen device includes: a hydrogen storage assembly, an ejector, a hydrogen circulation pump, A liquid-gas separator; the purging device includes: a deoxygenation bottle and a purging circulation pump;

The air inlet is connected to the air compressor assembly through the humidifier, and the air outlet is connected to the discharge device through the humidifier;

The hydrogen inlet is connected to the hydrogen storage assembly, the hydrogen outlet is connected to the liquid-gas separator, the liquid-gas separator has a drain port and a hydrogen discharge port, and the drain port is connected to the discharge device, The hydrogen exhaust port is connected to the hydrogen inlet through the ejector and the hydrogen circulation pump;

The deoxygenation bottle has an air inlet, a hydrogen inlet, a purge outlet and a discharge outlet, the air inlet is connected to the air compressor assembly, and the purge outlet is respectively connected to the air inlet and hydrogen through the purge circulation pump. The inlet is connected, and the outlet is connected with the discharge device.

The purging system of the fuel cell system provided by the present invention has at least the following beneficial effects: the air is fed into the battery system through the air compressor assembly for use, the source is abundant, the cost is low and reliable, and the air with high nitrogen content is deoxidized by the deoxygenation bottle , so as to obtain a purge gas source with superior purge performance, without the need for an additional nitrogen storage system. The use of nitrogen purging has little impact on the cathode and anode of the battery, requires low flow control, and will not increase the risk of reverse polarity. The tail hydrogen of the hydrogen device can be recycled through the ejector and the hydrogen circulation pump, and can also be used as a reducing agent to reduce the deoxidizer in the deoxidizer, which improves the utilization rate of hydrogen in the system and effectively solves the problem of tail hydrogen concentration. Hydrogen safety problems caused by too high.

As a further improvement of the above technical solution, the humidifier has a dry-side inlet connected to the air compressor assembly, a dry-side outlet connected to the air inlet, a wet-side inlet connected to the air outlet, and a Wet side outlet for drain communication.

Through the above technical scheme, the wet tail gas discharged from the battery stack enters the humidifier through the wet side inlet and is discharged from the wet side outlet; the dry gas to be humidified enters the humidifier from the dry side inlet and is converted into a gas rich in moisture Finally, it is discharged from the dry side outlet, and then enters the fuel cell stack.

As a further improvement of the above technical solution, both the wet side outlet and the drain port are connected to the discharge device through the deoxygenation bottle, the wet side outlet is connected to the air inlet, and the drain port is connected to the hydrogen inlet connected. Through the above technical scheme, both the tail drainage of the hydrogen device and the tail drainage of the air device are passed into the deoxidation bottle, and the humidity or water content in the deoxidation bottle is increased, thereby improving the deoxidation efficiency and utilization rate of the deoxidizer, and can control the number of components , reducing control requirements and system development costs.

As a further improvement of the above technical solution, the injector has an injection inlet connected to the hydrogen storage assembly, an injection outlet connected to the hydrogen inlet, and an injection return port connected to the hydrogen exhaust port . Through the above technical solution, the liquid-gas separator separates the tail hydrogen gas and passes it into the battery cell stack through the ejector through the hydrogen gas inlet for recycling. The hydrogen gas in the hydrogen storage component leads from the injection inlet to the injection outlet. Compared with the circulating hydrogen, it is a high-speed and high-energy flow, which can be evenly mixed with the circulating hydrogen.

As a further improvement of the above technical solution, the purging device further includes a purge bypass valve, and both ends of the purge bypass valve communicate with the air inlet and the outlet of the purge circulation pump respectively. Through the above technical solution, the purge bypass valve can form a circulation loop with the deoxidation bottle and the purge circulation pump, and the deoxygenation air can circulate in the circulation loop, so that the deoxidation treatment is more sufficient.

As a further improvement of the above technical solution, the purging device includes a purge solenoid valve, one side of the purge solenoid valve is connected to the outlet of the purge circulation pump; the hydrogen inlet or the hydrogen circulation pump One of the inlets, and the air inlet, are connected to the other side of the purge solenoid valve. Through the above technical scheme, the purge gas source is led to the air inlet through the purge circulation pump to realize cathode purge; directly to the hydrogen inlet or through the hydrogen circulation pump and then to the hydrogen inlet to realize anode purge. The purge solenoid valve can control the on-off of the purge gas source pipeline.

As a further improvement of the above technical solution, a purge heat exchanger is provided between the purge solenoid valve and the purge circulation pump, and the two ends of the purge heat exchanger are respectively connected to the purge solenoid valve and the purge circulation pump. The circulation pump is connected. Through the above technical solution, the purging heat exchanger can reduce the temperature of the purging gas source deoxidized by the deoxygenation bottle, so as to prevent the excessively high temperature of the purging gas source from flowing into the fuel cell stack and causing the stack to burn.

The present invention also provides a purging method. The purging method is based on the purging system of the above-mentioned fuel cell system. The deoxidizer is used for deoxidation treatment, and the deoxidized nitrogen gas is passed into the air inlet and the hydrogen gas inlet of the battery cell stack to realize the nitrogen purging of the anode and the cathode; In the deoxidizing bottle, it acts as a reducing agent to realize the reduction treatment of the oxidized deoxidizing agent.

The purging method provided by the present invention has at least the following beneficial effects: use air for deoxidation treatment to obtain a reliable source of nitrogen purge gas, and use nitrogen for cathode purge and anode purge, which improves the work of the fuel cell stack performance and reliability. Using the tail hydrogen gas from the hydrogen device as the reducing agent of the deoxygenation bottle effectively solves the hydrogen safety problem caused by the excessive hydrogen concentration in the tail gas, and at the same time improves the hydrogen utilization rate of the system. The purging method of the present invention has stable purging, improves the functionality of the fuel cell system, can reutilize tail hydrogen, and realizes the uniqueness of the product of the fuel cell system.

As a further improvement of the above technical solution, the deoxygenation bottle is integrated with a heating wire, an oxygen concentration sensor, a hydrogen concentration sensor, and a temperature sensor. The temperature sensor detects and determines the ambient temperature. The operating state of the hydrogen valve is used to control the start and stop of the deoxygenation bottle.

Through the above technical solution, the deoxidation bottle integrated with the resistance heating wire can ensure that the reduction reaction of the deoxidizer can proceed smoothly. Through the oxygen concentration sensor and the hydrogen concentration sensor, it can be ensured that no excess oxygen and hydrogen are involved in purging. The temperature is monitored by a temperature sensor, so that both the deoxidation treatment of the purge gas source and the reduction treatment of the deoxidizer can maintain an appropriate reaction temperature.

As a further improvement of the above technical solution, the oxygen concentration threshold and the hydrogen concentration threshold in the deoxygenation bottle are preset, and the fault is detected by real-time monitoring of the oxygen concentration and hydrogen concentration in the deoxygenation bottle and the power-on purge or shutdown of the fuel cell system is controlled. purge. Through the above technical solutions,

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention will be further described;

Fig. 1 is the purging system of the fuel cell system provided by the present invention, a structural schematic diagram of an embodiment thereof;

Fig. 2 is a schematic structural view of an embodiment of the purging system of the fuel cell system provided by the present invention;

Fig. 3 is a schematic structural view of an embodiment of the purge system of the fuel cell system provided by the present invention;

Fig. 4 is a schematic structural view of an embodiment of the purge system of the fuel cell system provided by the present invention;

Fig. 5 is a schematic structural view of an embodiment of the purge system of the fuel cell system provided by the present invention;

Fig. 6 is a purging method provided by the present invention, a schematic diagram of the control flow of the deoxygenation bottle in one embodiment;

Fig. 7 is a schematic flow chart of the shutdown and purge strategy in one embodiment of the purging method provided by the present invention;

FIG. 8 is a schematic flow chart of a power-on purging strategy in an embodiment of the purging method provided by the present invention.

In the figure: 11, battery stack; 20, air device; 21, air filter; 22, air compressor; 23, intercooler; 24, throttle; 25, humidifier; 26, back pressure valve; 27. Air bypass valve; 30. Hydrogen device; 31. Hydrogen storage bottle; 32. Stop valve; 33. Pressure reducing valve; 34. Safety valve; 35. Hydrogen heat exchanger; 36. Ejector; 37. Liquid Gas separator; 38. Ejector return check valve; 39. Hydrogen circulation pump; 310. Hydrogen circulation check valve; 311. Drain valve; 312. Hydrogen exhaust valve; 40. Purging device; 41. Purging circulation pump ;42, purge solenoid valve; 43, purge bypass valve; 44, deoxygenation bottle; 45, anode purge check valve; 46, cathode purge check valve; 47, purge drain valve; 48, purge Heat exchanger; 50, discharge device; 51, mixed discharge pipe; 52, muffler.

Detailed ways

This part will describe the specific embodiment of the present invention in detail, and the preferred embodiment of the present invention is shown in the accompanying drawings. Each technical feature and overall technical solution of the invention, but it should not be understood as a limitation on the protection scope of the present invention.

In the description of the present invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc. indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only In order to facilitate the description of the present invention and simplify the description, it does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, if there is a word description such as "several", the meaning is one or more, and the meaning of multiple is more than two. Greater than, less than, exceeding, etc. are understood as not including the original number, above and below , within, etc. are understood as including the original number.

In the description of the present invention, unless otherwise clearly defined, words such as setting, installation, and connection should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

Referring to Figures 1 to 8, the purging system of the fuel cell system of the present invention is implemented as follows:

A purging system for a fuel cell system, comprising: a cell stack 11 , an air device 20 , a hydrogen device 30 , a purging device 40 and a discharge device 50 .

The battery cell stack 11 has an air inlet, an air outlet, a hydrogen inlet and a hydrogen outlet. The battery stack 11 should also have the inlet and outlet of the thermal management system and the interface of the electrical system, but considering that the technical solution of the purge system proposed by the present invention mainly involves the air system and the hydrogen system, it does not do anything for the corresponding thermal management system or electrical system. out the description.

The air device 20 includes: an air compressor assembly and a humidifier 25 .

The humidifier 25 has a dry side inlet, a dry side outlet, a wet side inlet and a wet side outlet. The dry side inlet communicates with the air compressor assembly, the dry side outlet communicates with the air inlet, the wet side inlet communicates with the air outlet, and the wet side outlet communicates with the discharge device 50 connected.

The air inlet is connected to the air pressure assembly through the humidifier 25 , and the air outlet is connected to the discharge device 50 through the humidifier 25 .

The hydrogen device 30 includes: a hydrogen storage assembly, an ejector 36 , a hydrogen circulation pump 39 and a liquid-gas separator 37 . The hydrogen gas inlet is connected to the hydrogen storage assembly through the ejector 36 . The hydrogen outlet is connected to the liquid-gas separator 37 . The liquid-gas separator 37 has a drain port and a hydrogen discharge port. The water discharge port is connected with the discharge device 50 , and the hydrogen discharge port is connected with the hydrogen gas inlet through the ejector 36 and the hydrogen circulation pump 39 .

A hydrogen circulation check valve 310 is also provided between the outlet of the hydrogen circulation pump 39 and the hydrogen inlet. The inlet of the hydrogen circulation check valve 310 communicates with the outlet of the hydrogen circulation pump 39 . The hydrogen inlet, the outlet of the hydrogen circulation check valve 310 and the injection outlet are connected through a three-way pipe.

The purging device 40 includes: a deoxygenation bottle 44 and a purging circulation pump 41 . The deoxygenation bottle 44 has an air inlet, a hydrogen inlet, a purge outlet and a discharge outlet. The air inlet is connected with the air pressure assembly. The purge outlet is respectively connected to the air inlet and the hydrogen inlet through the purge circulation pump 41 . The discharge port is connected to the discharge device 50 .

The air pressure assembly includes: an air filter 21 , an air compressor 22 and an intercooler 23 . The air filter 21 , the air compressor 22 and the intercooler 23 communicate with each other in sequence.

In this embodiment, the air filter 21 is integrated with an ambient temperature sensor and an air flow meter, its inlet can be directly connected to the atmosphere, and its outlet is connected to the inlet of the air compressor 22 through a pipe. During the working process of the air compressor 22, negative pressure will be generated at its inlet. In order to avoid the phenomenon of sucking the connecting pipeline between the air compressor 22 and the air filter 21, it should be ensured that the air filter The connecting pipeline between the outlet of 21 and the inlet of the air compressor 22 should meet at least a pressure resistance of ±50kPa, and the specific pressure value can be determined according to the specific system.

The inlet of the intercooler 23 communicates with the outlet of the air compressor 22 , and the outlet of the intercooler 23 is connected with the air bypass valve 27 and the throttle valve 24 respectively through a three-way pipe. One side of the throttle valve 24 is connected to the outlet of the intercooler 23 through a tee pipe, and the other side is connected to the dry side inlet of the humidifier 25 . One side of the air bypass valve 27 is connected to the outlet of the intercooler 23 through a three-way pipe, and the other side is connected to the air inlet of the deoxygenation bottle 44 .

The humidifier 25 has a dry side channel and a wet side channel. The dry-side inlet and dry-side outlet are respectively arranged at both ends of the dry-side channel, and the wet-side inlet and wet-side outlet are respectively arranged at both ends of the wet-side channel. Before the air enters the stack, it is humidified externally by the humidifier 25, so as to ensure that the proton exchange membrane contains an appropriate amount of water. The wet side outlet of the humidifier 25 communicates with the discharge device 50 through the back pressure valve 26 .

The air in the atmosphere is initially filtered by the air filter 21, and then pressurized by the air compressor 22. The high-temperature air pressurized by the air compressor 22 can be lowered in temperature by the intercooler 23, and then sent to the humidifier 25 or deoxygenated bottle 44.

The hydrogen storage assembly includes: a hydrogen storage bottle 31 , a stop valve 32 , a pressure reducing valve 33 , a safety valve 34 and a hydrogen heat exchanger 35 . The hydrogen storage bottle 31 , shut-off valve 32 , decompression valve 33 , safety valve 34 and hydrogen heat exchanger 35 are connected to each other in sequence. The inlet of the stop valve 32 is connected to the outlet of the hydrogen storage bottle 31 , and the outlet of the stop valve 32 is connected to the inlet of the pressure reducing valve 33 . The inlet of the safety valve 34 is connected to the outlet of the pressure reducing valve 33 , and the outlet of the safety valve 34 is connected to the inlet of the hydrogen heat exchanger 35 .

The ejector 36 has an ejection inlet, an ejection outlet and an ejection return port. The outlet of the hydrogen heat exchanger 35 communicates with the injection inlet. The injection outlet is connected to the hydrogen inlet of the battery cell stack 11 .

The inlet of the liquid-gas separator 37 is connected with the hydrogen outlet of the battery cell stack 11, and the hydrogen outlet is connected with a four-way pipe. One of the nozzles of the four-way pipe is communicated with the inlet of the hydrogen circulation pump 39, the other nozzle is connected with the hydrogen inlet of the deoxygenation bottle 44 through the hydrogen discharge valve 312, and the other nozzles are connected through the ejection reflux unit. The direction valve 38 communicates with the ejection return port.

The inlet and outlet of the ejection return check valve 38 are respectively connected with the four-way pipe and the ejection return port, so that the hydrogen gas discharged from the hydrogen discharge port can flow in through the four-way pipe and the ejection return check valve 38 The ejector returns to the flow port.

Both ends of the hydrogen exhaust valve 312 are connected to the hydrogen exhaust port of the liquid-gas separator 37 and the hydrogen gas inlet of the deoxygenation bottle 44 respectively, so as to control the on-off of the hydrogen exhaust port and the hydrogen gas inlet. Both ends of the drain valve 311 are respectively connected to the drain port of the liquid-gas separator 37 and the discharge device 50 , so as to control the connection between the drain port and the discharge device 50 .

The purging device 40 includes a purging solenoid valve 42 . The purge outlet of the deoxygenation bottle 44 is connected with the inlet of the purge circulation pump 41 , and the outlet of the purge circulation pump 41 is connected with the purge solenoid valve 42 . One side of the purge solenoid valve 42 is connected to the outlet of the purge circulation pump 41, and the other side of the purge solenoid valve 42 is connected with an anode purge check valve 45 and a cathode purge valve through a three-way pipe. Check valve 46. The anode purge check valve 45 is connected with the inlet of the hydrogen circulation pump 39 and the hydrogen exhaust port through a three-way pipe. The cathode purge one-way valve 46 is connected between the air inlet and the dry side outlet of the humidifier 25 through a three-way pipe.

The purging device 40 also includes a purging bypass valve 43 . Both ends of the purge bypass valve 43 communicate with the outlet of the purge circulation pump 41 and the air inlet of the deoxygenation bottle 44 respectively. One side of the purge bypass valve 43 is connected between the purge solenoid valve 42 and the purge circulation pump 41 through a three-way pipe, and the other side is connected with the air bypass valve 27 and the deoxygenation bottle through a three-way pipe 44 between the air inlets.

The drain port of the liquid-gas separator 37 is connected to the discharge device 50 through a drain valve 311 . The discharge port of the deoxygenation bottle 44 is connected with the discharge device 50 through the purge and drain valve 47 .

The discharge device 50 includes: a mixing pipe 51 and a muffler 52 . The inlet of the mixing pipe 51 communicates with the back pressure valve 26 , the drain valve 311 and the purge and drain valve 47 respectively. The muffler 52 is disposed at the outlet of the mixing tube 51 . In this embodiment, the mixing pipe 51 has a drainage function to prevent excessive liquid water or water vapor from flowing into the muffler 52 , resulting in howling or performance degradation of the muffler 52 .

In a further embodiment shown in FIG. 3 , one side of the anode purge check valve 45 communicates with the purge solenoid valve 42 , and the other side communicates with the hydrogen gas of the battery stack 11 through a three-way pipe. The import is connected. The anode purge check valve 45 is directly connected to the hydrogen inlet, and the anode purge path does not need to pass through the hydrogen circulation pump 39 , which reduces the performance requirements of the purge circulation pump 41 and reduces development costs.

In a further embodiment as shown in FIG. 4 , the drain port of the liquid-gas separator 37 is connected to the hydrogen gas inlet of the deoxygenation bottle 44 through a drain valve 311 . One side of the drain valve 311 communicates with the drain port of the liquid-gas separator 37 , and the other side communicates between the hydrogen inlet and the hydrogen exhaust valve 312 through a three-way pipe. The tail water steam of the hydrogen device 30 is transported to the deoxidation bottle 44 to increase the humidity or water content in the deoxidation bottle 44 and improve the deoxidation efficiency and utilization rate of the deoxidizer in the deoxidation bottle 44 . Similarly, the wet side outlet of the humidifier 25 can also be connected with the air inlet of the deoxygenation bottle 44 through the back pressure valve 26 . The tail water vapor from the air device 20 and the hydrogen device 30 is passed into the deoxygenation bottle 44 to be consumed by the deoxidizer during the deoxidation reaction, and the excess water vapor can be transported to the mixing pipe 51 through the outlet for discharge.

In a further embodiment shown in FIG. 5 , the purging device 40 further includes a purging heat exchanger 48 . The purge heat exchanger 48 is arranged between the purge solenoid valve 42 and the purge circulation pump 41 . Two ends of the purging heat exchanger 48 are respectively connected with the purging electromagnetic valve 42 and the purging circulating pump 41 . The temperature of the purge gas source deoxidized by the deoxidation bottle 44 is lowered through the purge heat exchanger 48 to prevent the purge gas source with too high temperature from flowing into the fuel cell stack 11 and causing burning.

According to system requirements, in some embodiments, the liquid-gas separator 37 can integrate an ultrasonic liquid level sensor. The integrated ultrasonic liquid level sensor can cooperate with the drain valve 311 to realize the drain control of the liquid-gas separator 37 .

The present invention also provides a purging method based on the above purging system.

During the purging process, the air is passed into the deoxidation bottle 44 through the air compressor assembly, and the deoxidizer in the deoxidation bottle 44 is used for deoxidation treatment, and the deoxidized nitrogen gas is passed into the air inlet and hydrogen gas of the battery stack 11. The inlet realizes the nitrogen purging of the anode and the cathode; the tail hydrogen gas of the hydrogen device 30 is passed into the deoxidation bottle 44 through the hydrogen exhaust port, and acts as a reducing agent to realize the reduction treatment of the oxidized deoxidizer.

An appropriate amount of deoxidizer is provided inside the deoxidizer bottle 44 . The volume of the deoxidizer bottle 44 and the storage capacity of the deoxidizer depend on the power of the fuel cell system. In this embodiment, the deoxidizer is a mixture of reduced iron powder, activated carbon, water-absorbing resin and salt, which is non-toxic and tasteless, and has high deoxidation efficiency. Using water and salt as a catalyst, using the chemical reaction of iron and oxygen, it can absorb oxygen in the air powerfully and achieve the purpose of deoxidation. The specific chemical reaction formula is: 4Fe+3O2+6H2O→4Fe(OH)3.

The deoxygenation bottle 44 is integrated with a heating wire. The deoxidizer forms 4Fe(OH)3 after deoxidation. It is necessary to use the tail hydrogen gas from the hydrogen device 30 as a reducing agent to reduce 4Fe(OH)3 into reduced iron powder or active iron powder to ensure recycling. Specifically: first use high temperature to heat 4Fe(OH)3 to form Fe2O3. The hydrogen discharged from the hydrogen discharge valve 312 is then used as a reducing agent, and the reduction reaction is realized at a high temperature of 100° C. to 200° C. The specific chemical reaction is: 4Fe(OH)3→Fe2O3+H2→2Fe+3H2O.

The deoxygenation bottle 44 also integrates an oxygen concentration sensor, a hydrogen concentration sensor and a temperature sensor. The ambient temperature is detected and determined by the temperature sensor, and the start and stop of the deoxygenation bottle 44 is controlled according to the ambient temperature combined with the operating status of the vehicle system, the battery stack 11 and the hydrogen exhaust valve 312, so as to ensure an appropriate reaction temperature and no excess oxygen and hydrogen to participate in purging.

As shown in Figure 6, the concrete control method of described deoxygenation bottle 44 is as follows:

First, detect the ambient temperature and determine whether the ambient temperature sensor is abnormal.

If the ambient temperature sensor is faulty, report the fault and re-detect the ambient temperature. If there is no fault in the ambient temperature sensor, it is judged whether the ambient temperature is greater than the threshold T1.

If the ambient temperature is less than or equal to the threshold T1, the heating function of the deoxygenation bottle 44 is turned on. The opening time depends on the temperature identified by the temperature sensor in the deoxygenation bottle 44. The temperature threshold can be considered to be consistent with or higher than T1.

If the ambient temperature is greater than the threshold T1, it is determined whether the vehicle is running. If the vehicle is not running, the deoxygenation heating function is turned off; if the vehicle is running, it is judged whether the battery stack 11 is running. If the battery stack 11 is not running, then turn off the heating function of the deoxygenation bottle 44; if the battery stack 11 is running, it is judged whether the hydrogen discharge valve 312 is opened.

If the hydrogen discharge valve 312 is not opened, then close the heating function of the deoxygenation bottle 44; if the hydrogen discharge valve 312 is opened, then open the heating function of the deoxygenation bottle 44, and the opening time needs to be determined according to the hydrogen concentration identified by the hydrogen concentration sensor in the deoxygenation bottle 44 .

The ambient temperature threshold T1 can be set according to the actual situation and the usage environment. Generally speaking, it is better to set T1 above 0° C., which can avoid freezing of the reaction water inside the deoxygenation bottle 44 due to too low ambient temperature. The hydrogen concentration threshold is determined according to the sensitivity of the fuel cell stack 11 to the purge gas.

According to the purge sensitivity of the fuel cell stack 11 , the oxygen concentration threshold c1 and the hydrogen concentration threshold c2 in the deoxygenation bottle 44 are preset. Then by monitoring the oxygen concentration and hydrogen concentration in the deoxygenation bottle 44 in real time to detect faults and control the start-up or shutdown purge of the fuel cell system.

As shown in Figure 7, when shutting down and purging:

Firstly, it is judged whether the shutdown command of the fuel cell system has not been executed.

If the shutdown command of the fuel cell system is not executed, return to the previous level and continue to wait for the shutdown command; if the shutdown command of the fuel cell system is executed, it is judged whether the fuel cell system has not stopped working.

If the fuel cell system does not stop working, then return to the upper level and continue to wait for the shutdown command; if the fuel cell system has stopped working, then close the throttle valve 24, open the bypass valve, and input the deoxygenation source to the deoxygenating bottle 44.

Then, the oxygen concentration in the deoxygenation bottle 44 is detected to determine whether the oxygen concentration in the deoxygenation bottle 44 is greater than c1.

If the oxygen concentration is greater than c1, it is judged whether the oxygen concentration sensor is abnormal. If there is an abnormality in the oxygen concentration sensor, a fault is reported, and the oxygen concentration of the deoxygenation bottle 44 is re-detected after the fault is eliminated. If there is no abnormality in the oxygen concentration sensor, then close the purge solenoid valve 42 sequentially, run the purge circulation pump 41, open the purge bypass valve 43, and then re-detect the oxygen concentration of the deoxygenation bottle 44.

If the oxygen concentration is less than c1, then detect the hydrogen concentration in the deoxygenation bottle 44 to determine whether the hydrogen concentration in the deoxygenation bottle 44 is greater than c2.

If the hydrogen concentration in the deoxygenation bottle 44 is greater than c2, it is judged whether the hydrogen concentration sensor is abnormal. If there is an abnormality in the hydrogen concentration sensor, a fault is reported, and the hydrogen concentration in the deoxygenation bottle 44 is re-detected after the fault is eliminated. If there is no abnormality in the oxygen concentration sensor, then close the purge solenoid valve 42 in sequence, run the purge circulation pump 41, open the purge bypass valve 43, and then re-detect the hydrogen concentration of the dehydrogenation bottle.

If the hydrogen concentration in the deoxygenation bottle 44 is less than c2, then close the purge bypass valve 43 in sequence, run the purge circulation pump 41, open the purge solenoid valve 42, and then open the back pressure valve 26, drain valve 311 and hydrogen discharge valve 312 simultaneously.

After the above work is completed, the shutdown and purge strategy can be ended. The purge time can be calibrated according to the opening time of the purge bypass valve 43 , the opening time of the purge solenoid valve 42 , and different operating conditions of the fuel cell stack 11 .

As shown in Figure 8, when starting up and purging:

Firstly, it is judged whether the fuel cell system power-on command is not executed.

If the start-up command of the fuel cell system is not executed, return to the previous level and continue to wait for the start-up command; if the start-up command of the fuel cell system is executed, it is determined whether the fuel cell system is not started.

If the fuel cell system is not started, then return to the previous level and continue to wait for the start command; if the fuel cell system is started, then turn on the air system and the hydrogen system. Wherein, opening the air system refers to opening the air compressor 22 , the throttle valve 24 and the back pressure valve 26 . Turning on the hydrogen system refers to opening the stop valve 32 , the pressure reducing valve 33 , the hydrogen circulation pump 39 , the drain valve 311 and the hydrogen exhaust valve 312 .

After the air system and the hydrogen system are turned on, the oxygen concentration of the deoxygenation bottle 44 is detected to determine whether the oxygen concentration of the deoxygenation bottle 44 is greater than c1.

If the oxygen concentration is greater than c1, it is judged whether the oxygen concentration sensor is abnormal. If there is an abnormality in the oxygen concentration sensor, a fault is reported, and the oxygen concentration of the deoxygenation bottle 44 is re-detected after the fault is eliminated. If there is no abnormality in the oxygen concentration sensor, then close the purge solenoid valve 42 sequentially, run the purge circulation pump 41, open the purge bypass valve 43, and then re-detect the oxygen concentration of the deoxygenation bottle 44.

If the oxygen concentration is less than c1, then detect the hydrogen concentration in the deoxygenation bottle 44 to determine whether the hydrogen concentration in the deoxygenation bottle 44 is greater than c2.

If the hydrogen concentration in the deoxygenation bottle 44 is greater than c2, it is judged whether the hydrogen concentration sensor is abnormal. If there is an abnormality in the hydrogen concentration sensor, a fault is reported, and the hydrogen concentration in the deoxygenation bottle 44 is re-detected after the fault is eliminated. If there is no abnormality in the oxygen concentration sensor, then close the purge solenoid valve 42 in sequence, run the purge circulation pump 41, open the purge bypass valve 43, and then re-detect the hydrogen concentration of the dehydrogenation bottle.

If the hydrogen concentration in the deoxygenation bottle 44 is less than c2, the purge and drain valve 47 is opened.

After the above work is completed, the power-on purge strategy can be ended. In particular, when the air system is turned on, the air bypass valve 27 can be turned on or not according to the demand of the fuel cell stack 11 and the coordinated performance of the air compressor 22 .

In the description of this specification, references to the terms "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific examples," or "some examples" are intended to mean that the implementation A specific feature, structure, material, or characteristic described by an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can also make various changes, modifications, substitutions and modifications to these embodiments without departing from the principle and spirit of the present invention. Modifications, modifications, equivalent variations or replacements are all included within the scope defined by the claims of the present application, and the scope of the present invention is defined by the claims and their equivalents.

Claims (10)

1. A purging system for a fuel cell system, characterized in that: comprising: a cell stack (11), an air device (20), a hydrogen device (30), a purging device (40) and a discharge device (50); The battery cell stack (11) has an air inlet, an air outlet, a hydrogen inlet and a hydrogen outlet; the air device (20) includes: an air compressor assembly and a humidifier (25); the hydrogen device (30) includes: Hydrogen storage assembly, ejector (36), hydrogen circulation pump (39), liquid-gas separator (37); the purging device (40) includes: deoxygenation bottle (44) and purge circulation pump (41); The air inlet is connected to the air compressor assembly through the humidifier (25), and the air outlet is connected to the discharge device (50) through the humidifier (25); The hydrogen inlet is connected to the hydrogen storage assembly, the hydrogen outlet is connected to the liquid-gas separator (37), and the liquid-gas separator (37) has a drain port and a hydrogen discharge port, and the drain port is connected to the The discharge device (50) is connected, and the hydrogen discharge port is connected with the hydrogen inlet through the injector (36) and the hydrogen circulation pump (39); The deoxygenation bottle (44) has an air inlet, a hydrogen inlet, a purge outlet and a discharge outlet, the air inlet is connected to the air compressor assembly, and the purge outlet is connected to the purge circulation pump (41) respectively. The air inlet is connected to the hydrogen inlet, and the discharge port is connected to the discharge device (50). 2. The purging system of the fuel cell system according to claim 1, characterized in that: the humidifier (25) has a dry-side inlet communicated with the air pressure component, and a dry-side outlet communicated with the air inlet , a wet side inlet in communication with said air outlet, and a wet side outlet in communication with said exhaust (50). 3. The purging system of the fuel cell system according to claim 2, characterized in that: both the wet side outlet and the drain are connected to the discharge device (50) through the deoxygenation bottle (44), and the The wet side outlet is connected to the air inlet, and the drain is connected to the hydrogen inlet. 4. The purging system of the fuel cell system according to claim 1, characterized in that: the ejector (36) has an ejection inlet communicated with the hydrogen storage assembly, an ejector inlet communicated with the hydrogen inlet An injection port, and an ejection return port connected to the hydrogen exhaust port. 5. The purge system of the fuel cell system according to claim 1, characterized in that: the purge device (40) further comprises a purge bypass valve (43), and the purge bypass valve (43) The two ends of each communicate with the air inlet and the outlet of the purging circulation pump (41) respectively. 6. The purge system of the fuel cell system according to claim 1, characterized in that: the purge device (40) comprises a purge solenoid valve (42), and one side of the purge solenoid valve (42) Connected with the outlet of the purging circulation pump (41); one of the hydrogen inlet or the inlet of the hydrogen circulation pump (39) and the air inlet are connected with the outlet of the purging electromagnetic valve (42) connected on the other side. 7. The purge system of the fuel cell system according to claim 6, characterized in that: a purge heat exchanger (48) is provided between the purge solenoid valve (42) and the purge circulation pump (41) , the two ends of the purging heat exchanger (48) are respectively connected with the purging solenoid valve (42) and the purging circulation pump (41). 8. A purging method, characterized in that: the purging method is based on the purging system of the fuel cell system according to any one of claims 1 to 7, and the specific method is as follows: The air is passed into the deoxidation bottle (44) through the air pressure assembly, and the deoxidation treatment is carried out by the deoxidizer in the deoxidation bottle (44), and the nitrogen after the deoxidation is passed into the air inlet and hydrogen of the battery stack (11) Imported to realize nitrogen purge of anode and cathode; Tail exhaust hydrogen gas from the hydrogen device (30) is passed into the deoxidizer bottle (44) through the hydrogen exhaust port, and acts as a reducing agent to realize reduction treatment of the oxidized deoxidizer. 9. The purging method according to claim 8, characterized in that: the deoxygenation bottle (44) is integrated with a heating wire, an oxygen concentration sensor, a hydrogen concentration sensor and a temperature sensor, and the ambient temperature is detected and determined by the temperature sensor, according to The ambient temperature controls the start and stop of the deoxygenation bottle (44) in combination with the operating states of the vehicle system, the battery stack (11) and the hydrogen discharge valve (312). 10. The purging method according to claim 9, characterized in that: the oxygen concentration threshold and the hydrogen concentration threshold in the deoxygenation bottle (44) are preset, and the oxygen concentration and hydrogen in the deoxygenation bottle (44) are monitored in real time concentration to detect faults and control the start-up or shutdown purge of the fuel cell system.

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