US20160099477A1 - Passive anode gas recovery system for fuel cell - Google Patents
Passive anode gas recovery system for fuel cell Download PDFInfo
- Publication number
- US20160099477A1 US20160099477A1 US14/503,607 US201414503607A US2016099477A1 US 20160099477 A1 US20160099477 A1 US 20160099477A1 US 201414503607 A US201414503607 A US 201414503607A US 2016099477 A1 US2016099477 A1 US 2016099477A1
- Authority
- US
- United States
- Prior art keywords
- hydrogen gas
- ejector
- fuel cell
- fuel
- flow meter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 113
- 238000011084 recovery Methods 0.000 title claims abstract description 48
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 122
- 239000001257 hydrogen Substances 0.000 claims abstract description 21
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 21
- 239000007789 gas Substances 0.000 claims abstract description 17
- 238000004064 recycling Methods 0.000 claims abstract description 14
- 230000001105 regulatory effect Effects 0.000 claims description 10
- 239000012528 membrane Substances 0.000 claims description 6
- 238000012544 monitoring process Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 4
- 239000012530 fluid Substances 0.000 description 17
- 229910000831 Steel Inorganic materials 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 239000010959 steel Substances 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 3
- 238000012423 maintenance Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- -1 hydrogen ions Chemical class 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005381 potential energy Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000003050 experimental design method Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000008713 feedback mechanism Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000013178 mathematical model Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Images
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
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
- H01M8/04104—Regulation of differential pressures
-
- 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
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
- H01M8/04097—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with recycling 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
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
- H01M8/1018—Polymeric electrolyte materials
-
- 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
- H01M8/10—Fuel cells with solid electrolytes
- H01M2008/1095—Fuel cells with polymeric electrolytes
-
- 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
Definitions
- the present invention relates to a passive anode gas recovery system for fuel cells, especially to a passive fuel recovery system arranged at an outlet end of an anode of a fuel cell that recovers unconsumed hydrogen gas in the fuel cell for recycling and reuse.
- the passive fuel recovery system of the fuel cell has high efficiency and low cost.
- the two ejectors are connected to form a large-scale ejector for recycling and reuse of hydrogen gas not reacted. Yet the recovery efficiency is low due to insufficient vacuum in the ejector caused by the larger air chamber in the ejector. In order to overcome these shortcomings, there is a need to provide a novel recovery system for fuel cells with advantages of compact volume, light weight and low cost.
- a passive anode gas recovery system for fuel cells that includes a passive fuel recovery system disposed on an outlet end of an anode of a fuel cell and used for effective recycling and reuse of unconsumed hydrogen fuel in the fuel cell.
- the recycling system for fuel cells achieves higher efficiency with lower cost.
- the present invention provides a passive anode gas recovery system for fuel cells in which a fuel recovery system is arranged at an anode of a fuel cell and is used for recycling and reusing unconsumed hydrogen fuel in the fuel cell effectively.
- the passive anode gas recovery system for fuel cells includes a fuel cell, a fuel supply device, an electronically controlled regulator, a first ejection module, a second ejection module, a hydrogen recovery module, and a controller.
- a fuel input end and a fuel output end are disposed on an anode.
- the fuel supply device is connected to an electronically controlled regulator and is used for storage of hydrogen gas the fuel cell required.
- the pressure of the hydrogen gas is regulated by the electronically controlled regulator and then the hydrogen gas is output.
- the first ejection module is composed of a first solenoid valve, a first ejector and a first hydrogen gas flow meter.
- One end of the first ejection module is used to receive the hydrogen gas output from the fuel supply device and with the pressure regulated by the electronically controlled regulator.
- the first solenoid valve allows the hydrogen gas entering the first ejector to be pressured. Then the hydrogen gas passes through the other end of the first ejection module and enters the fuel input end to be used by the fuel cell.
- the first hydrogen gas flow meter is connected to the first ejector for monitoring flow rate of the hydrogen gas output from the first ejector.
- the second ejection module is connected to the first ejection module in parallel.
- the second ejection module is formed by a second solenoid valve, a second ejector and a second hydrogen gas flow meter.
- the hydrogen recovery module includes a third hydrogen gas flow meter and a fourth hydrogen gas flow meter. One end of the third hydrogen gas flow meter and one end of the fourth hydrogen gas flow meter are connected to the fuel output end of the fuel cell while the other end thereof are respectively connected to the first ejector and the second ejector for monitoring flow rate of the recovered hydrogen gas.
- the controller is connected to the fuel supply device and used for receiving parameters output from the first hydrogen gas flow meter, the second hydrogen gas flow meter, the third hydrogen gas flow meter, and the fourth hydrogen gas flow meter.
- the system judges the hydrogen gas should be recovered into the first ejector or the second ejector by the hydrogen recovery module for recycling and reuse.
- the first ejector and the second ejector respectively have a plurality of orifices having different diameters and made from electrochromic materials.
- the controller provides proper current for adjustment of the orifice diameter.
- the fuel cell is a proton exchange membrane fuel cell (PEMFC).
- PEMFC proton exchange membrane fuel cell
- the pressure of the hydrogen gas output from the fuel supply device is regulated by the electronically controlled regulator to be ranging from 1 bar to 10 bar. Then the hydrogen gas is used by the first ejector and the second ejector.
- the first ejector and the second ejector respectively have orifices with six different diameters ranging from 0.5 mm to 2 mm. It should be noted that the orifice diameters mentioned above are only some embodiments of the present invention, not intended to limit the scope of the present invention. People skilled in the related art know that the amount of the recovered hydrogen gas of the fuel cell 1 varies according to the orifice diameter of the ejector.
- the passive ejector of the present invention is used to replace conventional active mechanical pump for hydrogen recycling and having advantages of low cost, no extra energy consumption, no external control device required, compact volume, light weight, maintenance free etc.
- the present invention can be applied to developing a fuel cell systems with high efficiency and low cost. This is beneficial to development of industries such as fuel cell electric vehicle, fuel cell generator, etc.
- the ejector compresses hydrogen gas provided to the fuel cell by potential energy and sucks unused hydrogen gas. Such operation requires no electricity or energy input of mechanical shaft. Thus the mass of the equipment is reduced and the reliability is improved. And the problem of conventional mechanical pump for hydrogen recycling is solved. Two ejectors are used in the present invention for hydrogen recovery.
- the ejectors are easy to be replaced and the cost can be effectively controlled.
- the orifice of the ejector is made from electrochromic material.
- the controller supplies proper current for adjustment of the ejector orifice diameter according to system requirements.
- the power range of the fuel cell is adjusted by the changes of the ejector orifice diameter in real time manner. The wider the operation range of the power is, the higher the recovery efficiency the fuel cell has.
- the conventional ejector has the shortcoming of poor recovery efficiency.
- the present invention has precise and stable supply of hydrogen fuel by potential energy of the high pressure steel cylinder and the design of hydrogen gas flow meter to compensate the loss caused by low recovery efficiency of the ejector.
- the system of the present invention features on quick starting due to the proton exchange membrane fuel cell with low working temperature used. And the system has advantages of high reliability, long service life, strong environmental adaptability and low cost because it has high energy density and provides power required according to changes of load power.
- FIG. 1 is a schematic drawing showing structure of an embodiment of a passive anode gas recovery system for fuel cells according to the present invention
- FIG. 2 is a schematic drawing showing cross section of an ejector of an embodiment according to the present invention.
- FIG. 3 is a flow chart showing steps of an embodiment according to the present invention.
- the passive anode gas recovery system for fuel cells includes at least one fuel cell 1 , a fuel supply device 2 , an electronically controlled regulator 3 , a first ejection module 4 , a second ejection module 5 , a hydrogen recovery module 6 , and a controller 7 .
- the fuel cell 1 includes a fuel input end 111 and a fuel output end 112 , both disposed on an anode 11 thereof.
- the fuel cell 1 is a proton exchange membrane fuel cell with features of simple structure, easy operation, low working temperature, quick starting, no electrolyte loss, and excellent high current discharge performance has become the focus of research and development of the fuel cell 1 .
- Hydrogen gas and oxygen gas are respectively delivered to the anode 11 and a cathode 12 .
- Hydrogen gas is split into hydrogen ions and electrons by a catalyst at the anode 11 .
- the hydrogen ions are passed electrolytes and conducted to the cathode 12 while the electrons travel along an external circuit to the cathode 12 .
- PEMFC On a catalyst layer of the cathode 12 , oxygen molecules react with the electrons and protons to form water, which flows out of the cell along with gas at the cathode 12 . Due to low temperature operation of the PEMFC ranging about 60 ⁇ 80 , the fuel cell starts up quickly. Moreover, PEMFC has high energy density and provides power required according to changes of load power. Thus it's a leading candidate for replacement of conventional chargeable batteries and is applied to vehicles, buildings or portable devices. Along with the increasing applications, PEMFC has been developed along with high power, high reliability, long service life, good environmental adaptation, low cost, etc. The trend is more obvious in car fuel cells.
- the fuel supply device 2 is connected to an electronically controlled regulator 3 and is used for storage of hydrogen gas the fuel cell 1 required.
- the pressure of the hydrogen gas is regulated by the electronically controlled regulator 3 and then the hydrogen gas is output.
- a high pressure steel cylinder is used as the fuel supply device 2 .
- the high pressure steel cylinder is commonly used to store hydrogen gas.
- hydrogen gas is directly input into the fuel cell 1 .
- the pressure is increased a bit to ensure that the hydrogen gas is distributed over active area of the membrane inside the fuel cell 1 .
- the pressure should not be too high otherwise flow field plates and the proton exchange membrane may be damaged.
- the pressure of the gas is reduced by the electronically controlled regulator 3 and then the gas is delivered into the fuel cell 1 to have reactions.
- hydrogen gas unconsumed, it is recovered by a recovery system. There is limited volume of hydrogen gas within the high pressure steel cylinder. Once the hydrogen gas can be recovered, the service life of the high pressure steel cylinder can be increased.
- the electronically controlled regulator 3 features on two micro solenoid valves combined with software and hardware of driving circuit with multi-pulse width modulation (M-PWM). Pressure feedback technique is applied to precisely control the pilot pressure of the designed valve and further control the force that drives the main valve shaft for regulation of the pressure at the outlet end of the valve.
- M-PWM multi-pulse width modulation
- the pressure of the hydrogen gas output from the fuel supply device 2 and regulated by the electronically controlled regulator 3 is ranging from 1 bar to 10 bar and the hydrogen gas is used by the following ejectors.
- the first ejection module 4 consists of a first solenoid valve 41 , a first ejector 42 and a first hydrogen gas flow meter 43 .
- One end of the first ejection module 4 is used to receive the hydrogen gas output from the fuel supply device 2 and with the pressure regulated by the electronically controlled regulator 3 .
- the first solenoid valve 41 allows the hydrogen gas entering the first ejector 42 to be pressured. Then the hydrogen gas passes through the other end of the first ejection module 4 and enters the fuel input end 111 to be used by the fuel cell 1 .
- the first hydrogen gas flow meter 43 is connected to the first ejector 42 for monitoring flow rate of the hydrogen gas output from the first ejector 42 .
- the first ejector 42 can be a Venturi Vacuum Pump. No extra power is consumed and no additional control system is required.
- the ejector has simple structure and many advantages such as small volume, light weight, no maintenance, and low cost. Thus the ejector has been applied to industrial fields such as production and maintenance of vacuum state, low pressure vapor returning, etc.
- the ejector is mainly composed of a nozzle, a venture, a diffuser and a suction chamber. Energy and mass exchange between working fluid and driven fluid occurs in a mixing chamber. The speed of the working is decreased while the driven fluid is increased. The speed of the two kinds of fluid gradually becomes uniform at an outlet of the mixing chamber. While the mixed fluid passes through the diffuser, a part of kinetic energy is converted into pressure.
- the mixed fluid is output after being pressurized.
- the mixed fluid can be vapor phase, liquid phase, or a mixture of gas and fluid.
- the medium passed the nozzle is called working medium.
- the working medium fluid and the driven medium fluid are introduced into the mixing chamber for balancing the speed, generally along with the increasing of the pressure.
- the pressure of the fluid flowing from the mixing chamber to the diffuser keeps increasing.
- the pressure of the mixed fluid is larger than the pressure of the driven fluid entering a receiving chamber.
- the main function of the ejector is to increase pressure of the driven fluid without consuming mechanical energy directly. Refer to FIG. 2 , a cross section of the ejector is revealed. When hydrogen gas flows through an inlet (A) of the ejector and arrives a narrow nozzle (D), according to Law of conservation of mass:
- ⁇ is the gas density
- A is the cross-sectional area
- V is the average velocity of the fluid
- a A V A A D V D ,
- P A is the input pressure; .when the fluid flows to the nozzle (D), the pressure generated P D is much smaller than the input pressure P A .
- the gas moves form high pressure area to low pressure area.
- a suction force is generated at a suction inlet (C) when P D is smaller than a fixed value so as to recover the hydrogen gas to the ejector.
- the suction force the ejector generated enables hydrogen gas to carry water out. Then the water is removed by liquid gas separation.
- the second ejection module 5 is connected to the first ejection module 4 in parallel.
- the second ejection module 5 is formed by a second solenoid valve 51 , a second ejector 52 and a second hydrogen gas flow meter 53 .
- the orifice diameter of the first ejector 42 and the second ejector 52 is ranging from 0.5 mm to 2 mm.
- six ejectors with the orifice diameter of 0.5 mm, 0.7 mm, 1 mm, 1.3 mm, 1.5 mm, and 2 mm respectively are used for compressing hydrogen gas.
- the ejectors with the orifice diameter of 0.5 mm and 0.7 mm are small-orifice-diameter ejectors.
- the ejector In case of smaller orifice diameter, the ejector has smaller flow rate compared with other ejectors. Thus the corresponding power/watt is also limited. This is the shortcoming of ejectors with smaller orifice diameter. Yet the recovery flow rate of the small-orifice-diameter ejector is larger than the inlet flow rate. The small-orifice-diameter ejector has higher recovery efficiency. Moreover, the ejectors with orifice diameter of 1 mm, 1.3 mm, 1.5 mm, and 2 mm are large-orifice-diameter ejectors. Thus the corresponding flow rate is larger and the power is increased and having larger wattage range.
- the large-orifice-diameter ejectors have lower recovery flow rate and poor recovery efficiency.
- the orifice diameters mentioned above are only some embodiments of the present invention, not intended to limit the scope of the present invention. People skilled in the related art know that the amount of the recovered hydrogen gas of the fuel cell 1 varies according to the orifice diameter of the ejector.
- the hydrogen recovery module 6 includes a third hydrogen gas flow meter 61 and a fourth hydrogen gas flow meter 62 .
- One end of the third hydrogen gas flow meter 61 and one end of the fourth hydrogen gas flow meter 62 are connected to the fuel output end 112 of the fuel cell 1 while the other end thereof are respectively connected to the first ejector 42 and the second ejector 52 for monitoring flow rate of the recovered hydrogen gas.
- the controller 7 is connected to the fuel supply device 2 and used for receiving parameters output from the first hydrogen gas flow meter 43 , the second hydrogen gas flow meter 53 , the third hydrogen gas flow meter 61 , and the fourth hydrogen gas flow meter 62 . According to the parameters received, the system checks that the hydrogen gas should be recovered to the first ejector 42 or the second ejector 52 by the hydrogen recovery module for recycling and reuse.
- the first ejector 42 and the second ejector 52 respectively have a plurality of orifices having different diameters and made from electrochromic materials.
- the controller 7 provides proper current for adjustment of the orifice diameter.
- a fuel recovery system is disposed on the anode 11 of the fuel cell 1 by experimental design method and related experiments are carried out.
- LabVIEW graphical programming platform is used for system control and measuring experiment data.
- CFD-RC simulated software based on the multi-step finite volume method is used to carry out multi-physics coupling simulation according to structure and environment of the experiment system.
- the Mathematical Model and system control method related to the recovery mechanism are further discussed.
- the recovery system is integrated into the fuel cell 1 to form a complete system of the fuel cell 1 .
- FIG. 3 a flow chart showing steps of an embodiment of the present invention is disclosed.
- the fuel cell 1 reads data used and generates satisfaction-power figure (S-P figure) to simulate the amount of hydrogen gas the fuel cell 1 required.
- S-P figure satisfaction-power figure
- the fuel cell 1 sends a command to the electronically controlled regulator 3 for pressure adjustment.
- a Proportional-Integral-Derivative (PID) controller is used to reach a reference value of S-P figure.
- PID controller is a control loop feedback mechanism widely used in industrial control system. The data collected is compared with a reference value by the PID controller. Then a difference therebetween is used to calculate a new input value. The new input value is used to make the data of the system reach or maintain at the reference value.
- PID controller can adjust the input value based on historical data and occurrence frequency of the difference so as to make the system work/operate more precisely and stably.
- the first solenoid valve 41 disposed on the first ejection module 4 controls whether the hydrogen gas enters the first ejection module 4 or not.
- the first combination is that both solenoid valves 41 , 51 are off.
- both solenoid valves 41 , 51 are on.
- the first solenoid valve 41 is off while the second solenoid valve 51 is on.
- the fourth combination the first solenoid valve 41 is on while the second solenoid valve 51 is off.
- the equivalent number is divided by the value of 2 .
- the first solenoid valve 41 is off while the second solenoid valve 51 is on.
- the system uses the second ejection module 5 with larger orifice diameter and worse recovery efficiency as the main device to recover hydrogen gas.
- the first solenoid valve 41 is pulsed while the second solenoid valve 51 is on. The system activates the first ejection module 4 having smaller orifice diameter for hydrogen recovery and having higher recovery efficiency.
- the pressure is adjusted by electrically-controlled regulator 3 .
- Use PID program to make the pressure become consistent with the reference value of S-P figure.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Fuel Cell (AREA)
Abstract
Description
- 1. Fields of the invention
- The present invention relates to a passive anode gas recovery system for fuel cells, especially to a passive fuel recovery system arranged at an outlet end of an anode of a fuel cell that recovers unconsumed hydrogen gas in the fuel cell for recycling and reuse. The passive fuel recovery system of the fuel cell has high efficiency and low cost.
- 2. Descriptions of Related Art
- In order to provide current the load required, hydrogen gas more than the anode of fuel cells required is supplied. Thus a part of hydrogen gas unconsumed needs to be exhausted. However, once being exhausted to the atmosphere, there is a risk of explosion due to combustion reaction of the hydrogen gas. Thus the residual hydrogen gas must be recovered during operation of the fuel cell. In most of the fuel cells available now, active devices such as pumps are added for recycling of the hydrogen gas. Yet the pump added consumes more power. An extra controller is required for the system. This causes increasing of the cost and the volume of the system is larger. In order to solve the problem mentioned above, some research uses certain structure such as ejectors for hydrogen recovery of fuel cells. The two ejectors are connected to form a large-scale ejector for recycling and reuse of hydrogen gas not reacted. Yet the recovery efficiency is low due to insufficient vacuum in the ejector caused by the larger air chamber in the ejector. In order to overcome these shortcomings, there is a need to provide a novel recovery system for fuel cells with advantages of compact volume, light weight and low cost.
- Therefore it is a primary object of the present invention to provide a passive anode gas recovery system for fuel cells that includes a passive fuel recovery system disposed on an outlet end of an anode of a fuel cell and used for effective recycling and reuse of unconsumed hydrogen fuel in the fuel cell. In combination with features of PEMFC that has high energy density and provides power required along with changes of load power, the recycling system for fuel cells achieves higher efficiency with lower cost.
- In order to achieve the above object, the present invention provides a passive anode gas recovery system for fuel cells in which a fuel recovery system is arranged at an anode of a fuel cell and is used for recycling and reusing unconsumed hydrogen fuel in the fuel cell effectively. The passive anode gas recovery system for fuel cells includes a fuel cell, a fuel supply device, an electronically controlled regulator, a first ejection module, a second ejection module, a hydrogen recovery module, and a controller. In the fuel cell, a fuel input end and a fuel output end are disposed on an anode. The fuel supply device is connected to an electronically controlled regulator and is used for storage of hydrogen gas the fuel cell required. The pressure of the hydrogen gas is regulated by the electronically controlled regulator and then the hydrogen gas is output. The first ejection module is composed of a first solenoid valve, a first ejector and a first hydrogen gas flow meter. One end of the first ejection module is used to receive the hydrogen gas output from the fuel supply device and with the pressure regulated by the electronically controlled regulator. The first solenoid valve allows the hydrogen gas entering the first ejector to be pressured. Then the hydrogen gas passes through the other end of the first ejection module and enters the fuel input end to be used by the fuel cell. The first hydrogen gas flow meter is connected to the first ejector for monitoring flow rate of the hydrogen gas output from the first ejector. The second ejection module is connected to the first ejection module in parallel. The second ejection module is formed by a second solenoid valve, a second ejector and a second hydrogen gas flow meter. The hydrogen recovery module includes a third hydrogen gas flow meter and a fourth hydrogen gas flow meter. One end of the third hydrogen gas flow meter and one end of the fourth hydrogen gas flow meter are connected to the fuel output end of the fuel cell while the other end thereof are respectively connected to the first ejector and the second ejector for monitoring flow rate of the recovered hydrogen gas. The controller is connected to the fuel supply device and used for receiving parameters output from the first hydrogen gas flow meter, the second hydrogen gas flow meter, the third hydrogen gas flow meter, and the fourth hydrogen gas flow meter. According to the parameters received, the system judges the hydrogen gas should be recovered into the first ejector or the second ejector by the hydrogen recovery module for recycling and reuse. The first ejector and the second ejector respectively have a plurality of orifices having different diameters and made from electrochromic materials. The controller provides proper current for adjustment of the orifice diameter.
- The fuel cell is a proton exchange membrane fuel cell (PEMFC).
- The pressure of the hydrogen gas output from the fuel supply device is regulated by the electronically controlled regulator to be ranging from 1 bar to 10 bar. Then the hydrogen gas is used by the first ejector and the second ejector.
- The first ejector and the second ejector respectively have orifices with six different diameters ranging from 0.5 mm to 2 mm. It should be noted that the orifice diameters mentioned above are only some embodiments of the present invention, not intended to limit the scope of the present invention. People skilled in the related art know that the amount of the recovered hydrogen gas of the
fuel cell 1 varies according to the orifice diameter of the ejector. - Thereby the passive ejector of the present invention is used to replace conventional active mechanical pump for hydrogen recycling and having advantages of low cost, no extra energy consumption, no external control device required, compact volume, light weight, maintenance free etc. The present invention can be applied to developing a fuel cell systems with high efficiency and low cost. This is beneficial to development of industries such as fuel cell electric vehicle, fuel cell generator, etc. Moreover, the ejector compresses hydrogen gas provided to the fuel cell by potential energy and sucks unused hydrogen gas. Such operation requires no electricity or energy input of mechanical shaft. Thus the mass of the equipment is reduced and the reliability is improved. And the problem of conventional mechanical pump for hydrogen recycling is solved. Two ejectors are used in the present invention for hydrogen recovery. Thus the ejectors are easy to be replaced and the cost can be effectively controlled. Furthermore, the orifice of the ejector is made from electrochromic material. The controller supplies proper current for adjustment of the ejector orifice diameter according to system requirements. The power range of the fuel cell is adjusted by the changes of the ejector orifice diameter in real time manner. The wider the operation range of the power is, the higher the recovery efficiency the fuel cell has. The conventional ejector has the shortcoming of poor recovery efficiency. The present invention has precise and stable supply of hydrogen fuel by potential energy of the high pressure steel cylinder and the design of hydrogen gas flow meter to compensate the loss caused by low recovery efficiency of the ejector. In addition, the system of the present invention features on quick starting due to the proton exchange membrane fuel cell with low working temperature used. And the system has advantages of high reliability, long service life, strong environmental adaptability and low cost because it has high energy density and provides power required according to changes of load power.
- The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein
-
FIG. 1 is a schematic drawing showing structure of an embodiment of a passive anode gas recovery system for fuel cells according to the present invention; -
FIG. 2 is a schematic drawing showing cross section of an ejector of an embodiment according to the present invention; -
FIG. 3 is a flow chart showing steps of an embodiment according to the present invention. - Refer to
FIG. 1 , a schematic drawing showing structure of an embodiment of a passive anode gas recovery system used for fuel cells for effective recycling and reuse of hydrogen gas not reacted according to the present invention is revealed. The passive anode gas recovery system for fuel cells includes at least onefuel cell 1, afuel supply device 2, an electronically controlledregulator 3, afirst ejection module 4, asecond ejection module 5, ahydrogen recovery module 6, and acontroller 7. - The
fuel cell 1 includes afuel input end 111 and afuel output end 112, both disposed on ananode 11 thereof. Thefuel cell 1 is a proton exchange membrane fuel cell with features of simple structure, easy operation, low working temperature, quick starting, no electrolyte loss, and excellent high current discharge performance has become the focus of research and development of thefuel cell 1. Hydrogen gas and oxygen gas are respectively delivered to theanode 11 and acathode 12. Hydrogen gas is split into hydrogen ions and electrons by a catalyst at theanode 11. The hydrogen ions are passed electrolytes and conducted to thecathode 12 while the electrons travel along an external circuit to thecathode 12. On a catalyst layer of thecathode 12, oxygen molecules react with the electrons and protons to form water, which flows out of the cell along with gas at thecathode 12. Due to low temperature operation of the PEMFC ranging about 60˜80 , the fuel cell starts up quickly. Moreover, PEMFC has high energy density and provides power required according to changes of load power. Thus it's a leading candidate for replacement of conventional chargeable batteries and is applied to vehicles, buildings or portable devices. Along with the increasing applications, PEMFC has been developed along with high power, high reliability, long service life, good environmental adaptation, low cost, etc. The trend is more obvious in car fuel cells. - The
fuel supply device 2 is connected to an electronically controlledregulator 3 and is used for storage of hydrogen gas thefuel cell 1 required. The pressure of the hydrogen gas is regulated by the electronically controlledregulator 3 and then the hydrogen gas is output. In a preferred embodiment, a high pressure steel cylinder is used as thefuel supply device 2. The high pressure steel cylinder is commonly used to store hydrogen gas. After the pressure being reduced by the electronically controlledregulator 3, hydrogen gas is directly input into thefuel cell 1. When the hydrogen gas is delivered into thefuel cell 1, the pressure is increased a bit to ensure that the hydrogen gas is distributed over active area of the membrane inside thefuel cell 1. The pressure should not be too high otherwise flow field plates and the proton exchange membrane may be damaged. Thus the pressure of the gas is reduced by the electronically controlledregulator 3 and then the gas is delivered into thefuel cell 1 to have reactions. As to hydrogen gas unconsumed, it is recovered by a recovery system. There is limited volume of hydrogen gas within the high pressure steel cylinder. Once the hydrogen gas can be recovered, the service life of the high pressure steel cylinder can be increased. Moreover, the electronically controlledregulator 3 features on two micro solenoid valves combined with software and hardware of driving circuit with multi-pulse width modulation (M-PWM). Pressure feedback technique is applied to precisely control the pilot pressure of the designed valve and further control the force that drives the main valve shaft for regulation of the pressure at the outlet end of the valve. - In a preferred embodiment, the pressure of the hydrogen gas output from the
fuel supply device 2 and regulated by the electronically controlledregulator 3 is ranging from 1 bar to 10 bar and the hydrogen gas is used by the following ejectors. - The
first ejection module 4 consists of afirst solenoid valve 41, afirst ejector 42 and a first hydrogengas flow meter 43. One end of thefirst ejection module 4 is used to receive the hydrogen gas output from thefuel supply device 2 and with the pressure regulated by the electronically controlledregulator 3. Thefirst solenoid valve 41 allows the hydrogen gas entering thefirst ejector 42 to be pressured. Then the hydrogen gas passes through the other end of thefirst ejection module 4 and enters thefuel input end 111 to be used by thefuel cell 1. The first hydrogengas flow meter 43 is connected to thefirst ejector 42 for monitoring flow rate of the hydrogen gas output from thefirst ejector 42. Thefirst ejector 42 can be a Venturi Vacuum Pump. No extra power is consumed and no additional control system is required. The ejector has simple structure and many advantages such as small volume, light weight, no maintenance, and low cost. Thus the ejector has been applied to industrial fields such as production and maintenance of vacuum state, low pressure vapor returning, etc. The ejector is mainly composed of a nozzle, a venture, a diffuser and a suction chamber. Energy and mass exchange between working fluid and driven fluid occurs in a mixing chamber. The speed of the working is decreased while the driven fluid is increased. The speed of the two kinds of fluid gradually becomes uniform at an outlet of the mixing chamber. While the mixed fluid passes through the diffuser, a part of kinetic energy is converted into pressure. The mixed fluid is output after being pressurized. The mixed fluid can be vapor phase, liquid phase, or a mixture of gas and fluid. The medium passed the nozzle is called working medium. The working medium fluid and the driven medium fluid are introduced into the mixing chamber for balancing the speed, generally along with the increasing of the pressure. The pressure of the fluid flowing from the mixing chamber to the diffuser keeps increasing. At the outlet of the diffuser, the pressure of the mixed fluid is larger than the pressure of the driven fluid entering a receiving chamber. Thus the main function of the ejector is to increase pressure of the driven fluid without consuming mechanical energy directly. Refer toFIG. 2 , a cross section of the ejector is revealed. When hydrogen gas flows through an inlet (A) of the ejector and arrives a narrow nozzle (D), according to Law of conservation of mass: -
{dot over (m)}A={dot over (m)}D, - wherein {dot over (m)} is the mass flow rate; and
-
{dot over (m)}=ρAV, - wherein ρ is the gas density, A is the cross-sectional area, and V is the average velocity of the fluid; the fluid is considered as incompressible during the flowing process so that p can be neglected.
-
AAVA=ADVD, - wherein AA>>AD because the diameter of the nozzle (D) is much more smaller than the diameter of the inlet (A); thus
-
VD>>VA, - according to Bernoulli's Principle:
-
P A+1/2ρV A +ρgh A =P D+1/2ρV D +ρgh D, - wherein P is the pressure, g is the gravity, h is the height; the inlet (A) and the nozzle (D) are considered at the same horizontal level so that hA=hD,
-
P A+1/2ρV A =P D+1/2ρV D, - thus PA>>PD,
wherein PA is the input pressure;
.when the fluid flows to the nozzle (D), the pressure generated PD is much smaller than the input pressure PA. The gas moves form high pressure area to low pressure area. Thus a suction force is generated at a suction inlet (C) when PD is smaller than a fixed value so as to recover the hydrogen gas to the ejector. Moreover, the suction force the ejector generated enables hydrogen gas to carry water out. Then the water is removed by liquid gas separation. - The
second ejection module 5 is connected to thefirst ejection module 4 in parallel. Thesecond ejection module 5 is formed by asecond solenoid valve 51, asecond ejector 52 and a second hydrogengas flow meter 53. The orifice diameter of thefirst ejector 42 and thesecond ejector 52 is ranging from 0.5 mm to 2 mm. In a preferred embodiment of the present invention, six ejectors with the orifice diameter of 0.5 mm, 0.7 mm, 1 mm, 1.3 mm, 1.5 mm, and 2 mm respectively are used for compressing hydrogen gas. The ejectors with the orifice diameter of 0.5 mm and 0.7 mm are small-orifice-diameter ejectors. In case of smaller orifice diameter, the ejector has smaller flow rate compared with other ejectors. Thus the corresponding power/watt is also limited. This is the shortcoming of ejectors with smaller orifice diameter. Yet the recovery flow rate of the small-orifice-diameter ejector is larger than the inlet flow rate. The small-orifice-diameter ejector has higher recovery efficiency. Moreover, the ejectors with orifice diameter of 1 mm, 1.3 mm, 1.5 mm, and 2 mm are large-orifice-diameter ejectors. Thus the corresponding flow rate is larger and the power is increased and having larger wattage range. But compared with ejectors with small orifice diameter, the large-orifice-diameter ejectors have lower recovery flow rate and poor recovery efficiency. It should be noted that the orifice diameters mentioned above are only some embodiments of the present invention, not intended to limit the scope of the present invention. People skilled in the related art know that the amount of the recovered hydrogen gas of thefuel cell 1 varies according to the orifice diameter of the ejector. - The
hydrogen recovery module 6 includes a third hydrogengas flow meter 61 and a fourth hydrogengas flow meter 62. One end of the third hydrogengas flow meter 61 and one end of the fourth hydrogengas flow meter 62 are connected to thefuel output end 112 of thefuel cell 1 while the other end thereof are respectively connected to thefirst ejector 42 and thesecond ejector 52 for monitoring flow rate of the recovered hydrogen gas. - The
controller 7 is connected to thefuel supply device 2 and used for receiving parameters output from the first hydrogengas flow meter 43, the second hydrogengas flow meter 53, the third hydrogengas flow meter 61, and the fourth hydrogengas flow meter 62. According to the parameters received, the system checks that the hydrogen gas should be recovered to thefirst ejector 42 or thesecond ejector 52 by the hydrogen recovery module for recycling and reuse. Thefirst ejector 42 and thesecond ejector 52 respectively have a plurality of orifices having different diameters and made from electrochromic materials. Thecontroller 7 provides proper current for adjustment of the orifice diameter. - In the present invention, a fuel recovery system is disposed on the
anode 11 of thefuel cell 1 by experimental design method and related experiments are carried out. LabVIEW graphical programming platform is used for system control and measuring experiment data. Then CFD-RC simulated software based on the multi-step finite volume method is used to carry out multi-physics coupling simulation according to structure and environment of the experiment system. The Mathematical Model and system control method related to the recovery mechanism are further discussed. At last, design and develop an ideal passive recovery system according to the fuel recovery efficiency the PEMFC required. And the recovery system is integrated into thefuel cell 1 to form a complete system of thefuel cell 1. Due to complicated structure, expensive instrument, and risk of the hydrogen system, hydrogen gas is replaced by air the in beginning of the research to construct a gas recovery system for thefuel cell 1. Next the relation between air flow rate and flow rate of hydrogen gas is calculated by Reynolds number formula. Thus the performance of hydrogen gas in the ejector recovery system can be learned. - Refer to
FIG. 3 , a flow chart showing steps of an embodiment of the present invention is disclosed. - A. Reading Data and Simulating Requirement:
- The
fuel cell 1 reads data used and generates satisfaction-power figure (S-P figure) to simulate the amount of hydrogen gas thefuel cell 1 required. - B. Adjusting Pressure:
- The
fuel cell 1 sends a command to the electronically controlledregulator 3 for pressure adjustment. A Proportional-Integral-Derivative (PID) controller is used to reach a reference value of S-P figure. PID controller is a control loop feedback mechanism widely used in industrial control system. The data collected is compared with a reference value by the PID controller. Then a difference therebetween is used to calculate a new input value. The new input value is used to make the data of the system reach or maintain at the reference value. PID controller can adjust the input value based on historical data and occurrence frequency of the difference so as to make the system work/operate more precisely and stably. - C. Checking On/Off State of the Ejection Module:
- The
first solenoid valve 41 disposed on thefirst ejection module 4 controls whether the hydrogen gas enters thefirst ejection module 4 or not. There are four combinations when thefirst solenoid valve 41 disposed on thefirst ejection module 4 is used together with thesecond solenoid valve 51 of thesecond ejection module 5. The first combination is that bothsolenoid valves solenoid valves first solenoid valve 41 is off while thesecond solenoid valve 51 is on. In the fourth combination, thefirst solenoid valve 41 is on while thesecond solenoid valve 51 is off. - D. Reading Equivalent Number:
- Read the equivalent number of the
fuel cell 1. The equivalent number is divided by the value of 2. When the equivalent number is smaller than 2, thefirst solenoid valve 41 is off while thesecond solenoid valve 51 is on. And the system uses thesecond ejection module 5 with larger orifice diameter and worse recovery efficiency as the main device to recover hydrogen gas. When the equivalent number is larger than 2, thefirst solenoid valve 41 is pulsed while thesecond solenoid valve 51 is on. The system activates thefirst ejection module 4 having smaller orifice diameter for hydrogen recovery and having higher recovery efficiency. - E. Adjusting Wattage:
- The pressure is adjusted by electrically-controlled
regulator 3. Use PID program to make the pressure become consistent with the reference value of S-P figure. - F. Reading Information and Storing Data:
- Read program flow by all sensors. If there is a problem, the program turns the flow back to the process B, the step of adjusting pressure. The pressure is regulated by the electronically-controlled
regulator 3 and the reference value of the S-P figure is reached by the PID controller. Once the sensors check that there is no problem, record and store data related. The recovery of hydrogen gas is completed. - Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
Claims (4)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/503,607 US9312551B1 (en) | 2014-10-01 | 2014-10-01 | Passive anode gas recovery system for fuel cell |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/503,607 US9312551B1 (en) | 2014-10-01 | 2014-10-01 | Passive anode gas recovery system for fuel cell |
Publications (2)
Publication Number | Publication Date |
---|---|
US20160099477A1 true US20160099477A1 (en) | 2016-04-07 |
US9312551B1 US9312551B1 (en) | 2016-04-12 |
Family
ID=55633456
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/503,607 Expired - Fee Related US9312551B1 (en) | 2014-10-01 | 2014-10-01 | Passive anode gas recovery system for fuel cell |
Country Status (1)
Country | Link |
---|---|
US (1) | US9312551B1 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108875166A (en) * | 2018-05-25 | 2018-11-23 | 天津大学 | The modeling method of anode of fuel cell hydrogen is received using electrochemical hydrogen blowback |
CN110323470A (en) * | 2019-07-18 | 2019-10-11 | 中山大洋电机股份有限公司 | Fuel cell is into hydrogen regulating device and its fuel cell system of application |
CN110571456A (en) * | 2019-08-30 | 2019-12-13 | 孙军 | gas control device with composite function |
CN111740131A (en) * | 2020-06-24 | 2020-10-02 | 一汽解放汽车有限公司 | Hydrogen return system of fuel cell |
US20210226237A1 (en) * | 2020-01-22 | 2021-07-22 | Toyota Jidosha Kabushiki Kaisha | Fuel cell system |
CN115064729A (en) * | 2022-08-04 | 2022-09-16 | 佛山市清极能源科技有限公司 | Fuel cell hydrogen circulation system |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070044657A1 (en) * | 2005-09-01 | 2007-03-01 | Laven Arne | Fuel cell systems and methods for passively increasing hydrogen recovery through vacuum-assisted pressure swing adsorption |
US8206857B2 (en) * | 2007-06-26 | 2012-06-26 | Hyteon Inc. | Fuel cell combined heat and power generation |
CN103003999B (en) * | 2010-07-13 | 2015-04-01 | 丰田自动车株式会社 | Piping unit for use in fuel cell and fuel cell unit provided therewith, and fuel cell system |
-
2014
- 2014-10-01 US US14/503,607 patent/US9312551B1/en not_active Expired - Fee Related
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108875166A (en) * | 2018-05-25 | 2018-11-23 | 天津大学 | The modeling method of anode of fuel cell hydrogen is received using electrochemical hydrogen blowback |
CN110323470A (en) * | 2019-07-18 | 2019-10-11 | 中山大洋电机股份有限公司 | Fuel cell is into hydrogen regulating device and its fuel cell system of application |
CN110571456A (en) * | 2019-08-30 | 2019-12-13 | 孙军 | gas control device with composite function |
US20210226237A1 (en) * | 2020-01-22 | 2021-07-22 | Toyota Jidosha Kabushiki Kaisha | Fuel cell system |
US11695143B2 (en) * | 2020-01-22 | 2023-07-04 | Toyota Jidosha Kabushiki Kaisha | Fuel cell system |
CN111740131A (en) * | 2020-06-24 | 2020-10-02 | 一汽解放汽车有限公司 | Hydrogen return system of fuel cell |
CN115064729A (en) * | 2022-08-04 | 2022-09-16 | 佛山市清极能源科技有限公司 | Fuel cell hydrogen circulation system |
Also Published As
Publication number | Publication date |
---|---|
US9312551B1 (en) | 2016-04-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9312551B1 (en) | Passive anode gas recovery system for fuel cell | |
Liu et al. | Applications of ejectors in proton exchange membrane fuel cells: A review | |
CN110374856B (en) | Hydrogen injection pump test system for fuel cell | |
US10072342B2 (en) | Integrated electrochemical compressor and cascade storage method and system | |
US9590258B2 (en) | Apparatus and method for managing fuel cell vehicle system | |
CN103199282A (en) | Fuel cell supply including information storage device and control system | |
CA2566334A1 (en) | Cartridge with fuel supply and membrane electrode assembly stack | |
CN108875166A (en) | The modeling method of anode of fuel cell hydrogen is received using electrochemical hydrogen blowback | |
CN104979572A (en) | Fuel cell system control using an inferred mass air flow | |
CN113130941A (en) | Hydrogen supply system of proton exchange membrane hydrogen fuel cell and control method | |
CN105489973A (en) | High-performance metal air fuel cell system | |
CN202712342U (en) | Fuel cell device | |
US20070099045A1 (en) | Fuel cell device capable of adjusting operational parameters | |
TWI509871B (en) | Passive gas recovery system of fuel cell anode | |
CN117153280B (en) | Simulation model building method, simulation method and simulation system of alkaline electrolysis hydrogen production system | |
CN101853957A (en) | Fuel cell system | |
CN208889776U (en) | A kind of humidity control apparatus of fuel cell system | |
CN107195924A (en) | Fuel cell system, its control method and the vehicles including it | |
CN116031443A (en) | Test platform of hydrogen production and power generation integrated reversible system | |
CN109524692A (en) | Fuel cell system, fuel cell vehicle and hydrogen utilization rate improvement method | |
CN207441872U (en) | A kind of micro fuel cell apparatus | |
Spellman et al. | Economic report on vanadium redox flow battery with optimization of flow rate | |
KR100770429B1 (en) | Apparatus for testing efficiency of methanol fuel cell | |
CN109244512B (en) | Solid oxide fuel cell power generation system with supercharging function | |
US20230261217A1 (en) | Anode recovery system of fuel cell |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NATIONAL UNIVERSITY OF TAINAN, TAIWAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HWANG, JENN-JIANG;CHANG, CHUN-YUAN;LU, YEN-HSUN;AND OTHERS;REEL/FRAME:033870/0561 Effective date: 20141001 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YR, SMALL ENTITY (ORIGINAL EVENT CODE: M2551); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20240412 |