CN116682992B - Fuel cell system and shutdown purging method of fuel cell stack - Google Patents
Fuel cell system and shutdown purging method of fuel cell stack Download PDFInfo
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- CN116682992B CN116682992B CN202310942951.XA CN202310942951A CN116682992B CN 116682992 B CN116682992 B CN 116682992B CN 202310942951 A CN202310942951 A CN 202310942951A CN 116682992 B CN116682992 B CN 116682992B
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- 239000000446 fuel Substances 0.000 title claims abstract description 132
- 238000010926 purge Methods 0.000 title claims abstract description 39
- 238000000034 method Methods 0.000 title claims abstract description 22
- 239000001257 hydrogen Substances 0.000 claims abstract description 82
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 82
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 76
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 130
- 238000001514 detection method Methods 0.000 claims description 29
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 27
- 239000001301 oxygen Substances 0.000 claims description 22
- 229910052760 oxygen Inorganic materials 0.000 claims description 22
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 21
- 229910052757 nitrogen Inorganic materials 0.000 claims description 16
- 150000002431 hydrogen Chemical class 0.000 claims description 14
- 239000007788 liquid Substances 0.000 claims description 11
- 238000006243 chemical reaction Methods 0.000 claims description 10
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 6
- 238000012544 monitoring process Methods 0.000 claims description 5
- 239000000498 cooling water Substances 0.000 claims description 4
- 239000013589 supplement Substances 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 9
- 239000012528 membrane Substances 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- 239000000306 component Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000036284 oxygen consumption Effects 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- HEZMWWAKWCSUCB-PHDIDXHHSA-N (3R,4R)-3,4-dihydroxycyclohexa-1,5-diene-1-carboxylic acid Chemical compound O[C@@H]1C=CC(C(O)=O)=C[C@H]1O HEZMWWAKWCSUCB-PHDIDXHHSA-N 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04223—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
- H01M8/04228—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells during shut-down
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04223—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
- H01M8/04231—Purging of the reactants
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04223—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
- H01M8/04253—Means for solving freezing problems
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
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- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Fuel Cell (AREA)
Abstract
The application relates to the technical field of fuel cells and discloses a fuel cell system and a shutdown purging method of the fuel cell stack, wherein the shutdown purging method comprises the fuel cell stack, a hydrogen supply assembly, an air supply assembly, a hydrothermal circulation assembly and an electronic control module, the hydrogen supply assembly, the air supply assembly and the hydrothermal circulation assembly are all communicated with the fuel cell stack, the air supply assembly comprises an air compressor, an air pressure sensor, a first tee joint, a first stop valve and a first tail discharge valve, the air compressor is communicated with one end of the air pressure sensor, the other end of the air pressure sensor is communicated with an A port of the first tee joint through the fuel cell stack, a B port of the first tee joint is communicated with the first tail discharge valve, the other end of the first tail discharge valve is communicated with the external environment, a C port of the first tee joint is communicated with the first stop valve, and the other end of the first stop valve is communicated with the air compressor. The application has the effect of relieving the problem of poor purging effect of the fuel cell stack.
Description
Technical Field
The present application relates to the field of fuel cells, and more particularly, to a shutdown purge method for a fuel cell system and a fuel cell stack.
Background
A fuel cell is a chemical device that directly converts chemical energy of fuel into electric energy, and is also called an electrochemical generator. The electrochemical principle, namely the primary cell working principle, is adopted to directly convert chemical energy stored in fuel and oxidant into electric energy isothermally, so that the actual process is oxidation-reduction reaction.
The fuel cell system comprises a fuel cell stack, a hydrogen supply system, an air supply system, a water heat management system and an electric control system, wherein the core component is the fuel cell stack. A fuel cell stack is a location where hydrogen and oxygen react electrochemically, converting fuel chemical energy into electrical energy.
When the fuel cell system is shut down, water vapor and liquid water generated by reaction remain in the electric pile. Wherein, partial air can permeate to the anode side of the electric pile to form a hydrogen-air interface, so that the catalyst is attenuated, and the electric pile performance is reduced. The water generated by the reaction remains in the electric pile and can be frozen into ice in a low-temperature environment, on one hand, the ice in the catalytic layer in the electric pile can cover the catalyst reaction sites, so that the reaction area is reduced; on the other hand, repeated icing and deicing in the membrane electrode in the electric pile can lead to the mechanical property attenuation of the membrane electrode and reduce the service life of the membrane electrode.
Currently, most of the existing fuel cells are purged with nitrogen after shutdown to drain the water remaining in the fuel cells.
In view of the above related art, the inventors consider that purging the fuel cell with nitrogen gas requires additional accessories, and there is a problem that the volume and mass of the fuel cell system are increased, which affects the mobility thereof, and increases the additional cost of the fuel cell system.
Disclosure of Invention
In order to alleviate the above-described problems, the present application provides a fuel cell system.
The application provides a fuel cell system, which adopts the following technical scheme:
the utility model provides a fuel cell system, includes fuel cell stack, hydrogen supply subassembly, air supply subassembly, hydrothermal circulation subassembly and electronic control module, hydrogen supply subassembly, air supply subassembly and hydrothermal circulation subassembly all communicate with fuel cell stack, the inside reaction of oxyhydrogen fuel cell stack is used for producing electric energy, heat energy and water, electronic control module is connected with the fuel cell stack electricity, air supply subassembly includes air compressor machine, air pressure sensor, first tee bend, first stop valve and first tail row valve, air compressor machine and air pressure sensor's one end intercommunication, air pressure sensor's the other end passes through fuel cell stack and first tee bend's A mouth intercommunication, first tee bend's B mouth and first tail row valve intercommunication, first tail row valve's the other end and external environment intercommunication, first tee's C mouth and first stop valve intercommunication, first stop valve's the other end and air compressor machine intercommunication.
By adopting the technical scheme, before the fuel cell system is shut down, the first stop valve is opened, the tail exhaust valve is closed, and air at the cathode outlet is sent back to the stack inlet, so that a loop is formed inside; at the moment, the electric pile works normally, but the output current/voltage drops gradually, and under the action of the air compressor, a part of fresh air still enters the electric pile along with the continuous consumption of oxygen in the circulating air, but the amount of the entering air is gradually reduced to 0; the air in the electric pile is circularly purged at the cathode side, the circulated air is heated to carry the water generated by the reaction and the water remained in the electric pile enters the water tank in a high-temperature saturated steam state, and the water is condensed by the fins in the water tank and then is collected at the bottom of the water tank. Finally, the reaction is stopped gradually due to the too low oxygen content, and the oxygen consumption circulation process is stopped after the temperature of the electric pile is reduced to the normal temperature. Purging the cathode of the fuel cell stack is completed without adding additional accessories, and the main component of the air remaining in the cathode is nitrogen, so that most of moisture in the cathode cavity is brought into the water tank after circulation.
Optionally, the electronic control module includes a temperature detection sensor for detecting an external ambient temperature, and the temperature detection sensor is electrically connected to the hydrogen supply assembly.
By adopting the technical scheme, the temperature detection sensor is used for detecting the working environment temperature of the fuel cell system, and if the working environment temperature is higher than the set temperature, only the oxygen in the cathode of the fuel cell stack needs to be emptied before shutdown; if the operating environment temperature is lower than the set temperature, water in the fuel cell stack needs to be drained.
Optionally, the hydrogen supply subassembly includes second stop valve, ejector, second tee bend and second tail valve, second stop valve one end and hydrogen gas source intercommunication, the other end and the inlet end intercommunication of ejector of second stop valve, the end of giving vent to anger of ejector passes through the fuel cell stack and communicates with the A mouth of second tee bend, the B mouth of second tee bend and second tail valve intercommunication, the other end and the external environment intercommunication of second tail valve, the C mouth of second tee bend and the entrance point intercommunication of ejector, temperature-detecting sensor is connected with second tail valve electricity.
Through adopting the technical scheme, the air outlet end of the ejector is communicated with the A port of the second tee joint through the fuel cell stack, the B port of the second tee joint is communicated with the second tail discharge valve, the C port of the second tee joint is communicated with the inlet end of the ejector, the temperature detection sensor is electrically connected with the second stop valve, when the temperature detection sensor detects that the temperature of the external environment is lower than the set temperature, the temperature detection sensor transmits a signal to enable the second tail discharge valve to be opened, the pressure for conveying hydrogen to the inside of the fuel cell stack is increased, the anode of the fuel cell stack is purged by utilizing dry hydrogen, one part of wet hydrogen circulates through the ejector, and the other part of wet hydrogen is discharged through the tail discharge valve and is brought out of liquid water at the anode side; as the anode side is continuously replenished with dry hydrogen, the anode side is eventually filled with dry hydrogen.
Optionally, the bipolar plate of the fuel cell stack is a porous bipolar plate.
By adopting the technical scheme, the bipolar plate of the fuel cell stack is a porous bipolar plate, and in the process of purging the anode of the fuel cell stack by utilizing hydrogen, part of liquid water in the porous bipolar plate is purged into the cathode side cavity by the hydrogen at the anode side, and nitrogen in the cathode side cavity is gradually replaced by dry hydrogen until the cathode side cavity is fully filled with the dry hydrogen.
Optionally, the electronic control module comprises a discharge resistor and a voltage detection element, wherein the discharge resistor is electrically connected with the fuel cell stack, and the voltage detection element is used for monitoring the average voltage value of the fuel cell stack.
By adopting the technical scheme, the average voltage value of the fuel cell stack is monitored by the voltage detection element, and when the voltage value is 0, the oxygen in the cathode of the fuel cell stack is completely consumed.
Optionally, a hydrogen concentration detecting member is arranged at one end of the first tail exhaust valve, which is communicated with the external environment.
By adopting the technical scheme, the hydrogen concentration detection part is utilized to monitor the gas exhausted by the first tail exhaust valve, and when the hydrogen concentration rises to a certain value, the anode of the fuel cell stack is filled with hydrogen.
Optionally, the hydrothermal circulation assembly includes water pump, water tank and third stop valve, the water inlet and the fuel cell stack intercommunication of water pump, the delivery port and the water tank intercommunication of water pump, third stop valve one end and water tank intercommunication, the other end and the fuel cell stack intercommunication of third stop valve.
Optionally, a negative pressure sensor is arranged between the water inlet of the water pump and the fuel cell stack, the negative pressure sensor is used for monitoring the pressure in the flow channel, and the negative pressure sensor is electrically connected with the water pump.
By adopting the technical scheme, a negative pressure sensor is arranged between the water inlet of the water pump and the fuel cell stack, so that the negative pressure is ensured not to exceed a set value; when the negative pressure sensor detects that the negative pressure is too high, the rotating speed of the water pump is reduced or the water pump is turned off, and after the negative pressure is reduced, the rotating speed of the water pump is increased or the water pump is turned on, so that the water in the electric pile can be pumped out as much as possible, and the damage of the membrane electrode caused by the too high negative pressure can be avoided.
In order to alleviate the above problems, the application also provides a shutdown purge method of the fuel cell stack.
The application provides a shutdown purging method of a fuel cell stack, which adopts the following technical scheme:
a shutdown purging method for a fuel cell stack mainly comprises the following steps:
s1: opening the first stop valve, closing the first tail valve, and returning the air discharged from the cathode outlet of the fuel cell stack to the stack inlet again to form a loop; at the moment, the electric pile works normally, but the output current/voltage drops gradually, under the action of the air compressor, along with the continuous consumption of oxygen in the circulating air, a part of fresh air still enters the electric pile, but the amount of the air entering the electric pile is gradually reduced to 0, and finally, the main component of the air reserved in the cathode is nitrogen, and the air compressor and the first stop valve are closed;
s2: detecting the temperature of the external environment through a temperature detection sensor, stopping the machine after the purging is finished if the temperature of the external environment is higher than the set temperature, and continuing the next step if the temperature of the external environment is higher than the set temperature;
s3: opening a second tail discharge valve, increasing the pressure of delivering hydrogen to the inside of the fuel cell stack, purging the anode of the fuel cell stack by using dry hydrogen, wherein one part of wet hydrogen circulates through an ejector, and the other part of wet hydrogen is discharged through the tail discharge valve and brings out liquid water at the anode side; along with the continuous supplement of the dry hydrogen on the anode side, the anode side is finally filled with the dry hydrogen;
s4: opening a first tail discharge valve, and purging part of liquid water in the porous bipolar plate into a cathode side cavity by the anode side hydrogen, wherein nitrogen in the cathode side cavity is gradually replaced by dry hydrogen until the cathode side cavity is fully filled with the dry hydrogen;
s5: and closing the third stop valve and starting the water pump, wherein the water pump enters a low-rotation-speed working mode, and the water pump pumps out water in the cooling water flow channel and water in the cathode and anode flow channels in the porous bipolar plate.
Through adopting above-mentioned technical scheme, whole shut down sweeps the process under the condition that does not increase extra annex, utilizes the circulation of high pressure hydrogen and air to sweep, discharges oxygen and water in the fuel cell pile, can prevent to form the empty interface of hydrogen on the one hand, avoids causing the decay of catalyst, on the other hand, prevents that the inside of pile from freezing after the low temperature environment shut down, improves the pile life-span and reduces the difficulty of restarting simultaneously. In addition, the purging mode does not need to additionally add an inert gas source, reduces the complexity of the system, increases the reliability of the system, and avoids the pressure fluctuation and the safety problem caused by gas source switching; the water in the electric pile is pumped by utilizing high-pressure hydrogen, air circulation and negative pressure of a water pump, so that the water is thoroughly removed compared with the normal-pressure purging based on nitrogen; the hydrogen has lighter specific gravity than nitrogen and better escape property, and is more suitable for filling the cathode cavity; can prevent the damage of water to the air compressor in the air circulation process, and improve the service life of the air compressor.
Optionally, S3, S4 and S5 are performed synchronously.
By adopting the technical scheme, the time for purging is reduced, and the purging efficiency is improved.
In summary, the present application includes at least one of the following beneficial technical effects:
1. one end of an air pressure sensor is communicated with an A port of a first tee joint through a fuel cell stack, a B port of the first tee joint is communicated with a first tail discharge valve, a C port of the first tee joint is communicated with a first stop valve, the other end of the first stop valve is communicated with an air compressor, before the fuel cell system is shut down, the first stop valve is opened, the tail discharge valve is closed, air at a cathode outlet is returned to an inlet of the stack, a loop is formed inside the stack, at the moment, the stack normally works, but the output current/voltage gradually drops, under the action of the air compressor, along with the continuous consumption of oxygen in circulating air, a part of fresh air still enters the stack, but the entering air is gradually reduced to 0, the air inside the stack is circularly purged at the cathode side, water generated by carrying a reactor after the temperature rise of the circulating air and water reserved in the stack enters a water tank in a high-temperature saturated vapor state, and is collected at the bottom of the water tank after the water tank is condensed, finally, due to the fact that the oxygen content is too low, the reactor gradually stops, after the temperature of the stack is reduced to normal temperature, the oxygen consumption circulation process is stopped, and the fuel cell normally works, but the stack is completed, on the condition that accessories are not additionally added, but the output current/voltage gradually drops, and the oxygen is gradually, a part of the oxygen is still in the cathode is prevented from being polluted, and the air is greatly, the air is in the air cavity, and the air is greatly reduced, and the air is in the air cavity, and the environment is prevented from being turned down, and the cathode, and the air is in the air is caused by the situation that the air is being caused by the air, and the air is being in the air and the air;
through setting up the negative pressure sensor between water inlet and the fuel cell pile of water pump, guarantee that the negative pressure does not surpass the setting value, when negative pressure sensor detects that the negative pressure is too high, reduce the water pump rotational speed or close the water pump, improve the water pump rotational speed again or start the water pump after the negative pressure reduces, also can avoid the membrane electrode harm that the negative pressure caused when taking out the inside moisture of pile as far as possible.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute a limitation on the application. In the drawings:
FIG. 1 is a schematic overall structure of an embodiment of the present application;
FIG. 2 is a schematic view of the structure of a portion of an air supply assembly according to an embodiment of the present application;
fig. 3 is a schematic view showing the structures of a hydrogen supply unit portion and a hydrothermal circulation unit portion in the embodiment of the application.
Reference numerals: 100. a fuel cell stack; 200. a hydrogen supply assembly; 210. a second shut-off valve; 220. an ejector; 230. a second tee; 240. a second tail gate valve; 300. an air supply assembly; 310. an air compressor; 320. an air pressure sensor; 330. a first tee; 340. a first stop valve; 350. a first tail gate; 400. a hydrothermal circulation assembly; 410. a water pump; 420. a water tank; 430. a third stop valve; 440. a negative pressure sensor; 500. and a hydrogen concentration detecting member.
Detailed Description
In order to more clearly illustrate the general inventive concept, the present application will be described in further detail below with reference to fig. 1-3.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, however, the present application may be practiced in other ways than those described herein, and therefore the scope of the present application is not limited to the specific embodiments disclosed below. It should be noted that, without conflict, embodiments of the present application and features in each embodiment may be combined with each other.
The embodiment of the application discloses a fuel cell system. Referring to fig. 1 and 2, a fuel cell system includes a fuel cell stack 100, a hydrogen supply assembly 200, an air supply assembly 300, a hydrothermal circulation assembly 400, and an electronic control module, each of the hydrogen supply assembly 200, the air supply assembly 300, and the hydrothermal circulation assembly 400 being in communication with the fuel cell stack 100, the hydrogen-oxygen fuel cell stack 100 internally reacting to generate electric power, heat energy, and water, the electronic control module being electrically connected with the fuel cell stack 100.
The air supply assembly 300 includes an air compressor 310, an air pressure sensor 320, a first tee joint 330, a first stop valve 340 and a first tail valve 350, wherein the air compressor 310 is communicated with one end of the air pressure sensor 320, the other end of the air pressure sensor 320 is communicated with an A port of the first tee joint 330 through the fuel cell stack 100, a B port of the first tee joint 330 is communicated with the first tail valve 350, the other end of the first tail valve 350 is communicated with the external environment, a C port of the first tee joint 330 is communicated with the first stop valve 340, and the other end of the first stop valve 340 is communicated with the air compressor 310.
Before the fuel cell system is shut down, the first stop valve 340 is opened, the tail discharge valve is closed, and air at the outlet of the cathode is sent back to the inlet of the electric pile, and a loop is formed inside; at this time, the pile works normally, but the output current/voltage drops gradually, and under the action of the air compressor 310, along with the continuous consumption of oxygen in the circulating air, a part of fresh air still enters the pile, but the amount of the entering air decreases gradually to 0. The air in the electric pile is circularly purged at the cathode side, water generated by carrying reaction after the temperature of the circulated air rises and water remained in the electric pile enter the water tank 420 in a high-temperature saturated steam state, the water is condensed by the fins in the water tank 420 and then is collected at the bottom of the water tank 420, finally, the reaction is gradually stopped due to the too low oxygen content, and the oxygen consumption circulation process is stopped after the temperature of the electric pile is reduced to normal temperature. The purging of the cathode of the fuel cell stack 100 is completed without adding additional accessories, at this time, the main component of the air remaining in the cathode is nitrogen, and most of the moisture in the cathode cavity is brought into the water tank 420 after circulation, so that on one hand, the formation of a hydrogen-air interface can be prevented, the attenuation of the catalyst is avoided, on the other hand, the icing of the inside of the stack after the shutdown in a low-temperature environment is prevented, and the restarting difficulty is reduced.
Referring to fig. 2 and 3, the electronic control module includes a discharge resistor and a voltage detecting element, the discharge resistor being electrically connected with the fuel cell stack 100. The voltage detection element is used to monitor the average voltage value of the fuel cell stack 100. The consumption of oxygen is mainly determined by the voltage output by the stack. With the continuous decrease of oxygen, the output voltage of the electric pile is synchronously decreased, when the voltage is decreased to 45V (250-electricity-saving pile), DCDC stops working, the discharge resistor continues to discharge to about 24V (250-electricity-saving pile), the air compressor 310 and the first stop valve 340 are closed, and the main component of air in the cathode is nitrogen.
Referring to fig. 1 and 3, the electronic control module further includes a temperature detection sensor for detecting an external ambient temperature, and the temperature detection sensor is electrically connected with the hydrogen supply assembly 200. Detecting the working environment temperature of the fuel cell system by using a temperature detection sensor, and if the working environment temperature is higher than a set temperature, only evacuating oxygen in the cathode of the fuel cell stack 100 before stopping; if the operating environment temperature is lower than the set temperature, water in the fuel cell stack 100 needs to be discharged.
Referring to fig. 1, 2 and 3, the hydrogen supply assembly 200 includes a second shut-off valve 210, an ejector 220, a second tee 230 and a second tail discharge valve 240, one end of the second shut-off valve 210 is communicated with a hydrogen gas source, the other end of the second shut-off valve 210 is communicated with an air inlet end of the ejector 220, an air outlet end of the ejector 220 is communicated with an a port of the second tee 230 through the fuel cell stack 100, a B port of the second tee 230 is communicated with the second tail discharge valve 240, the other end of the second tail discharge valve 240 is communicated with an external environment, a C port of the second tee 230 is communicated with an inlet end of the ejector 220, and a temperature detection sensor is electrically connected with the second tail discharge valve 240. When the temperature detection sensor detects that the temperature of the external environment is lower than the set temperature, the temperature detection sensor transmits a signal to enable the second tail discharge valve 240 to be opened, the pressure of delivering hydrogen into the fuel cell stack 100 is increased, the anode of the fuel cell stack 100 is purged by using dry hydrogen, one part of wet hydrogen circulates through the ejector 220, and the other part of wet hydrogen is discharged through the tail discharge valve and brings liquid water at the anode side; as the anode side is continuously replenished with dry hydrogen, the anode side is eventually filled with dry hydrogen.
Referring to fig. 2 and 3, the bipolar plates of the fuel cell stack 100 are porous bipolar plates, and during purging of the anode of the fuel cell stack 100 with hydrogen, the anode side hydrogen purges a portion of the liquid water in the porous bipolar plates into the cathode side cavity, and the nitrogen in the cathode side cavity is gradually replaced with dry hydrogen until the cathode side cavity is completely filled with dry hydrogen. The hydrogen concentration detecting member 500 is disposed at one end of the first tail gas discharge valve 350, which communicates with the external environment, and the hydrogen concentration detecting member 500 is used to monitor the gas discharged from the first tail gas discharge valve 350, and when the hydrogen concentration rises to a certain value, the anode of the fuel cell stack 100 is filled with hydrogen.
Referring to fig. 1, 2 and 3, the hydrothermal circulation assembly 400 includes a water pump 410, a water tank 420, and a third shut-off valve 430, a water inlet of the water pump 410 is communicated with the fuel cell stack 100, a water outlet of the water pump 410 is communicated with the water tank 420, one end of the third shut-off valve 430 is communicated with the water tank 420, and the other end of the third shut-off valve 430 is communicated with the fuel cell stack 100. Before the shutdown, the third stop valve 430 is closed, the water pump 410 enters a low rotation speed operation mode, and the negative pressure circulating pump pumps water in the cooling water flow channels out of the inside of the pile on one hand, and pumps water in the cathode/anode flow channels in the porous bipolar plate out through negative pressure on the other hand.
In a preferred embodiment, a negative pressure sensor 440 is disposed between the water inlet of the water pump 410 and the fuel cell stack 100, the negative pressure sensor 440 is used for monitoring the pressure in the flow channel, and the negative pressure sensor 440 is electrically connected with the water pump 410. When the negative pressure sensor 440 detects that the negative pressure is too high, the rotation speed of the water pump 410 is reduced or the water pump 410 is turned off, and after the negative pressure is reduced, the rotation speed of the water pump 410 is increased or the water pump 410 is turned on, so that the water in the electric pile can be pumped out as much as possible, and the damage of the membrane electrode caused by the too high negative pressure can be avoided. The pump head adopts the PWM duty ratio to control the negative pressure value to be constant at 20kpa, the PWM duty ratio of the water pump 410 is about 50% when the fuel cell is in a normal working state, and the pump head can maintain the constant negative pressure of 20kpa only by about 10% of the duty ratio when the pump head is in a dry state, so when the duty ratio of the water pump 410 is controlled to be less than 15%, the negative pressure in the fuel cell stack 100 is stopped to pump water, the water pump 410 continues to work, the pump head is spin-dried, the water pump 410 is closed, and the third stop valve 430 is opened.
The embodiment of the application also discloses a shutdown purging method of the fuel cell stack 100, which mainly comprises the following steps:
s1: opening the first shut-off valve 340, closing the first tail-gate valve 350, and returning the air exhausted from the cathode outlet of the fuel cell stack 100 to the stack inlet again to form a loop; at this time, the electric pile works normally, but the output current/voltage drops gradually, and under the action of the air compressor 310, along with the continuous consumption of oxygen in the circulating air, a part of fresh air still enters the electric pile, but the amount of the entering air decreases gradually to 0; the consumption of oxygen is mainly determined by the voltage output by the electric pile, the output voltage of the electric pile is synchronously reduced along with the continuous reduction of oxygen, when the voltage is reduced to 45V (250-voltage-saving pile), DCDC stops working, the discharge resistor continues to discharge to about 24V (250-voltage-saving pile), the air compressor 310 and the first stop valve 340 are closed, and the main component of air in the cathode is nitrogen.
S2: detecting the temperature of the external environment through a temperature detection sensor, stopping the machine after the purging is finished if the temperature of the external environment is higher than the set temperature, and continuing the next step if the temperature of the external environment is higher than the set temperature;
s3: opening a second tail discharge valve 240 to increase the pressure of delivering hydrogen to the inside of the fuel cell stack 100, purging the anode of the fuel cell stack 100 with dry hydrogen, circulating a part of the wet hydrogen through the ejector 220, discharging the other part of the wet hydrogen through the tail discharge valve, and carrying out liquid water on the anode side; with the continuous replenishment of the dry hydrogen gas at the anode side, the hydrogen gas concentration detection member 500 is used to monitor the gas discharged from the first tail gas discharge valve 350, and when the hydrogen gas concentration rises to a certain value, the anodes of the fuel cell stack 100 are filled with hydrogen gas;
s4: opening the first tail gas discharge valve 350, and purging part of liquid water in the porous bipolar plate into the cathode side cavity by the anode side hydrogen, wherein nitrogen in the cathode side cavity is gradually replaced by dry hydrogen until the cathode side cavity is completely filled with the dry hydrogen;
s5: the third stop valve 430 is closed and the water pump 410 is started, the water pump 410 enters a low-rotation-speed working mode, the water pump 410 pumps out water in the cooling water flow channel and water in the cathode and anode flow channels in the porous bipolar plate, when the duty ratio of the water pump 410 is controlled to be smaller than 15%, negative pressure water pumping in the fuel cell stack 100 is stopped, the water pump 410 continues to work, the water pump 410 is closed after the pump head is spin-dried, and meanwhile the third stop valve 430 is opened.
The whole shutdown purging process utilizes the high-pressure hydrogen and air to circularly purge and discharge oxygen and water in the fuel cell stack 100 under the condition that no additional accessories are added, so that on one hand, a hydrogen-air interface can be prevented from being formed, the attenuation of a catalyst is avoided, on the other hand, the inside of the stack is prevented from being frozen after the shutdown in a low-temperature environment, the service life of the stack is prolonged, and meanwhile, the restarting difficulty is reduced. In addition, the purging mode does not need to additionally add an inert gas source, reduces the complexity of the system, increases the reliability of the system, and avoids the pressure fluctuation and the safety problem caused by gas source switching; the water in the electric pile is pumped by utilizing high-pressure hydrogen, air circulation and negative pressure of the water pump 410, so that the water is thoroughly removed compared with the normal-pressure purging based on nitrogen; the hydrogen has lighter specific gravity than nitrogen and better escape property, and is more suitable for filling the cathode cavity; the damage of water to the air compressor 310 during the air circulation process can be prevented, and the life of the air compressor 310 can be prolonged.
In a preferred embodiment, S3, S4 and S5 are performed simultaneously, thereby improving the efficiency of shutdown purge and reducing the time spent for purge.
The application can be realized by adopting or referring to the prior art at the places which are not described in the application.
The above embodiments are not intended to limit the scope of the present application, so: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.
Claims (10)
1. A shutdown purge method for a fuel cell stack, comprising the steps of:
the fuel cell system applied to the shutdown purging method comprises a fuel cell stack, a hydrogen supply assembly, an air supply assembly, a hydrothermal circulation assembly and an electronic control module, wherein a bipolar plate of the fuel cell stack is a porous bipolar plate;
the air supply assembly comprises an air compressor, an air pressure sensor, a first tee joint, a first stop valve and a first tail discharge valve, wherein the air compressor is communicated with one end of the air pressure sensor, the other end of the air pressure sensor is communicated with an A port of the first tee joint through a fuel cell stack, a B port of the first tee joint is communicated with the first tail discharge valve, the other end of the first tail discharge valve is communicated with the external environment, a C port of the first tee joint is communicated with the first stop valve, and the other end of the first stop valve is communicated with the air compressor;
the electronic control module comprises a temperature detection sensor for detecting the temperature of the external environment;
the hydrogen supply assembly comprises a second stop valve, an ejector, a second tee joint and a second tail discharge valve, one end of the second stop valve is communicated with a hydrogen gas source, the other end of the second stop valve is communicated with an air inlet end of the ejector, an air outlet end of the ejector is communicated with an A port of the second tee joint through a fuel cell stack, a B port of the second tee joint is communicated with the second tail discharge valve, the other end of the second tail discharge valve is communicated with the external environment, a C port of the second tee joint is communicated with an inlet end of the ejector, and the temperature detection sensor is electrically connected with the second tail discharge valve;
s1: opening the first stop valve, closing the first tail valve, and returning the air discharged from the cathode outlet of the fuel cell stack to the stack inlet again to form a loop; at the moment, the electric pile works normally, but the output current/voltage drops gradually, under the action of the air compressor, along with the continuous consumption of oxygen in the circulating air, a part of fresh air still enters the electric pile, but the amount of the air entering the electric pile is gradually reduced to 0, and finally, the main component of the air reserved in the cathode is nitrogen, and the air compressor and the first stop valve are closed;
s2: detecting the temperature of the external environment through a temperature detection sensor, stopping the machine after the purging is finished if the temperature of the external environment is higher than the set temperature, and continuing the next step if the temperature of the external environment is higher than the set temperature;
s3: opening a second tail discharge valve, increasing the pressure of delivering hydrogen to the inside of the fuel cell stack, purging the anode of the fuel cell stack by using dry hydrogen, wherein one part of wet hydrogen circulates through an ejector, and the other part of wet hydrogen is discharged through the tail discharge valve and brings out liquid water at the anode side; along with the continuous supplement of the dry hydrogen on the anode side, the anode side is finally filled with the dry hydrogen;
s4: opening a first tail discharge valve, and purging part of liquid water in the porous bipolar plate into a cathode side cavity by the anode side hydrogen, wherein nitrogen in the cathode side cavity is gradually replaced by dry hydrogen until the cathode side cavity is fully filled with the dry hydrogen;
s5: and closing the third stop valve and starting the water pump, wherein the water pump enters a low-rotation-speed working mode, and the water pump pumps out water in the cooling water flow channel and water in the cathode and anode flow channels in the porous bipolar plate.
2. A shutdown purge method of a fuel cell stack according to claim 1, wherein: s3, S4 and S5 are performed synchronously.
3. A fuel cell system employing the shutdown purge method of the fuel cell stack of any one of claims 1 to 2, characterized in that: the fuel cell system comprises a fuel cell stack, a hydrogen supply assembly, an air supply assembly, a hydrothermal circulation assembly and an electric control module, wherein the hydrogen supply assembly, the air supply assembly and the hydrothermal circulation assembly are all communicated with the fuel cell stack, an internal reaction of the fuel cell stack is used for generating electric energy, heat energy and water, the electric control module is electrically connected with the fuel cell stack, the air supply assembly comprises an air compressor, an air pressure sensor, a first tee joint, a first stop valve and a first tail discharge valve, the air compressor is communicated with one end of the air pressure sensor, the other end of the air pressure sensor is communicated with an A port of the first tee joint through the fuel cell stack, a B port of the first tee joint is communicated with the first tail discharge valve, the other end of the first tail discharge valve is communicated with an external environment, a C port of the first tee joint is communicated with the first stop valve, and the other end of the first stop valve is communicated with the air compressor.
4. A fuel cell system according to claim 3, wherein: the electronic control module comprises a temperature detection sensor for detecting the temperature of the external environment, and the temperature detection sensor is electrically connected with the hydrogen supply assembly.
5. The fuel cell system according to claim 4, wherein: the hydrogen supply assembly comprises a second stop valve, an ejector, a second tee joint and a second tail discharge valve, one end of the second stop valve is communicated with a hydrogen gas source, the other end of the second stop valve is communicated with the air inlet end of the ejector, the air outlet end of the ejector is communicated with an A port of the second tee joint through a fuel cell stack, a B port of the second tee joint is communicated with the second tail discharge valve, the other end of the second tail discharge valve is communicated with the external environment, a C port of the second tee joint is communicated with the inlet end of the ejector, and the temperature detection sensor is electrically connected with the second tail discharge valve.
6. A fuel cell system according to claim 3, wherein: the bipolar plates of the fuel cell stack are porous bipolar plates.
7. A fuel cell system according to claim 3, wherein: the electric control module comprises a discharge resistor and a voltage detection element, wherein the discharge resistor is electrically connected with the electric pile, and the voltage detection element is used for monitoring the average voltage value of the fuel cell electric pile.
8. A fuel cell system according to claim 3, wherein: one end of the first tail exhaust valve, which is communicated with the external environment, is provided with a hydrogen concentration detection part.
9. A fuel cell system according to claim 3, wherein: the hydrothermal circulation assembly comprises a water pump, a water tank and a third stop valve, a water inlet of the water pump is communicated with the fuel cell stack, a water outlet of the water pump is communicated with the water tank, one end of the third stop valve is communicated with the water tank, and the other end of the third stop valve is communicated with the fuel cell stack.
10. The fuel cell system according to claim 9, wherein: a negative pressure sensor is arranged between the water inlet of the water pump and the fuel cell stack, the negative pressure sensor is used for monitoring the pressure in the flow channel, and the negative pressure sensor is electrically connected with the water pump.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111029620A (en) * | 2019-11-29 | 2020-04-17 | 同济大学 | Fuel cell system with tail discharge nitrogen collecting device and shutdown purging method |
| CN111740135A (en) * | 2020-05-20 | 2020-10-02 | 广东国鸿氢能科技有限公司 | Start-stop method and device for water guide bipolar plate fuel cell |
| CN111785995A (en) * | 2020-06-16 | 2020-10-16 | 广东国鸿氢能科技有限公司 | Purging pipeline system for water guide bipolar plate fuel cell |
| CN211700443U (en) * | 2020-04-27 | 2020-10-16 | 罗伯特·博世有限公司 | Water separator, fuel gas supply system, and fuel cell system |
| CN114927728A (en) * | 2022-04-13 | 2022-08-19 | 东风汽车集团股份有限公司 | Shutdown and discharge control method and device for fuel cell system and vehicle |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111029620A (en) * | 2019-11-29 | 2020-04-17 | 同济大学 | Fuel cell system with tail discharge nitrogen collecting device and shutdown purging method |
| CN211700443U (en) * | 2020-04-27 | 2020-10-16 | 罗伯特·博世有限公司 | Water separator, fuel gas supply system, and fuel cell system |
| CN111740135A (en) * | 2020-05-20 | 2020-10-02 | 广东国鸿氢能科技有限公司 | Start-stop method and device for water guide bipolar plate fuel cell |
| CN111785995A (en) * | 2020-06-16 | 2020-10-16 | 广东国鸿氢能科技有限公司 | Purging pipeline system for water guide bipolar plate fuel cell |
| CN114927728A (en) * | 2022-04-13 | 2022-08-19 | 东风汽车集团股份有限公司 | Shutdown and discharge control method and device for fuel cell system and vehicle |
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