Measurement And Evaluation Methodology Of Hydrogen Injector And Hydrogen Recirculation Pump For Fuel Cell Engines

As one of the main subsystems for fuel cell engines,the performances of hydrogen recirculation system is crucial.Hydrogen injector and hydrogen circulation pump are the key components of the hydrogen circulation system.In this paper,the test conditions and test methods for the performance evaluation of hydrogen injector and hydrogen recirculation pump are investigated.The measurement and evaluation system is further constructed,and the methodology verification is carried out.The details are summarized as follows:(1)This paper introduces the development status of fuel cell vehicles and their components.The research status of hydrogen injector and hydrogen recirculation pump are focused on.However,a comprehensive measurement and evaluation system for hydrogen injector and hydrogen recirculation pump is still lacked.(2)Firstly,based on the test conditions of hydrogen injector and hydrogen recirculation pump,this paper proposes the design requirements that the test platform should meet.Built the test platform and developed the hardware and software for the test platform,which lays the foundation for subsequent measurement and evaluation studies.(3)Then,this paper establishes a performance index system for hydrogen injectors,including general performances,operating characteristics,environmental adaptability,and endurance reliability.This index system is verified by experimental tests.After experimental tests,it is found that the hydrogen injector operates with congestion effects,and this phenomenon is found to solve the problem that the outlet flow rate of the hydrogen injector is almost constant when the back pressure is adjusted.For the actual application scenario of hydrogen injector,this paper designs a performance test scheme considering stack power to simulate the hydrogen consumption conditions.The flow rate is controlled for hydrogen consumption simulation.The opening and closing of solenoid valve is adopted to simulate the pulsed discharge of the tail discharge valve for fuel cell engines,which further improves the measurement methodology of hydrogen injectors.(4)Finally,This paper also establishes a performance index system for hydrogen recirculation pumps,including general performances,operating characteristics,environmental adaptability,and endurance reliability.This index system is verified by experimental tests.In addition,this paper designs a method based on different test media to verify the performance of hydrogen recirculation pump.Due to the differences in kinematic viscosity between nitrogen and hydrogen,the hydrogen recirculation pump performs better when tested with nitrogen,which provides important guidance for the subsequent evaluation with other media.