Active thermal management between proton exchange membrane fuel cell and metal hydride hydrogen storage tank considering long-term operation

Abstract

A fuel cell power system integrating proton-exchange-membrane fuel cell (PEMFC) and metal hydride (MH)-based hydrogen storage tank presents great potential in transportation applications. The embedded PEMFC and MH tank are thermally coupled through a heat ex-changer and control system. The hydrogen generating and supplying rate from the MH tank to PEMFC is strongly influenced by the transferred heat, which affects the performance of long-term operation as well. In this work, the dynamic behavior of the fuel cell system is simulated with a mathematical model set and validated using a database from the real operation vehicles. Thanks to the heat ex-changer combined by fan, radiator and circulation water, the hydrogen flow rate from MH tank to PEMFC is well controlled to meet the requirement of power load. The simulated model describes the response of each component including the power and heat generated by PEMFC, the hydrogen desorption kinetics and the heat transfer in the system. A thermal management strategy with a PID controller is proposed to reduce the degradation and extend the lifespan of PEMFC. The results demonstrate that an optimized performance of PEMFC after 1000 h is realized. In spite of the MH tank degradation rate has been raised 0.3%, 2.5% of voltage degradation of PEMFC is reduced. Meanwhile, for the integration fuel cell system, more than 3% of fuel efficiency and 10% of fuel economy is saved.