Research On Dynamic Hydrogen Supply Strategy For Anode Of Air-cooled Proton Exchange Membrane Fuel Cell

Proton Exchange Membrane Fuel Cell(PEMFC)has become an ideal choice facing energy and environmental problems because of its advantages of pollution free,high energy density,fast cold start-up and low operating temperature.Compared with watercooled PEMFC,air-cooled PEMFC without the equipment of cooling liquid circulation and reactive gas humidification,has the advantages of light weight and simple structure,which is considered as an ideal future power source for small power systems.The hydrogen supply strategies have great impacts on the performance and life of the aircooled PEMFC.In this thesis,a series experiments were performed on a laboratory developed 2k W air-cooled PEMFC to research the impacts on its performance by the amount of hydrogen supply,and explored the suitable dynamic hydrogen supply strategies.The main contents of this thesis are as follows:1.The influence of the amount of hydrogen supply on the performance of the aircooled PEMFC in the open anode mode and the dead-ended anode mode was researched by experiments.In the open hydrogen supply mode,the influence of the hydrogen supply flow rate on its output voltage and consistency of node voltage were explored.In the dead-ended-end hydrogen supply mode,the influence of hydrogen supply pressure on its output voltage,consistency of node voltage and loading performance were explored.2.In this thesis,dynamic hydrogen supply strategies for an air-cooled PEMFC were studied.The strategies were divided into two types,i.e.,fixed exhaust cycle and adaptively adjusting exhaust cycle based on output voltage.Model-free iterative learning control algorithms were proposed in this research.Specifically,these algorithms were used to iteratively optimize the opening and closing trigger conditions of the exhaust valve of air-cooled PEMFC.Based on the experimental results,two dynamic hydrogen supply strategies with the optimal output performance were obtained.And then,by calculating the data from the experiments,we obtained two dynamic hydrogen supply strategies with optimal energy consumption ratio.3.In order to verify the effectiveness of the dynamic hydrogen supply strategies in actual use scenarios,this thesis selected the scenario of the UAV fuel cell power supply system.The electronic load of the test platform was used to simulate the working conditions of DJI S1000+ UAV cruising under different take-off weights.The simulation experiments verified the effectiveness of the two dynamic hydrogen supply strategies with the optimal energy consumption ratio.Then,according to the test results of the verification experiments,the actual use effects of these two dynamic hydrogen supply strategies were compared.In this thesis,it is found that the dynamic hydrogen supply strategies can make the air-cooled PEMFC work in a more efficient and stable working condition,and these strategies can reduce the hydrogen usage amount and increase the life of the air-cooled PEMFC,thereby reduce the cost of the air-cooled PEMFC power supply systems.