Research On Solar Thermal Reforming Hydrogen Production Experiment And Fuel Cell Hybrid System

With the economic development of mankind in the future,both the environmental pollution and energy shortage will become increasingly prominent,so the future energy utilization should be more inclined to clean energy and renewable energy.As a kind of clean energy without pollution,solar energy has the disadvantages of time and space discontinuity,high utilization cost and low efficiency,so,the solar thermochemical energy storage has received more attention and development.Based on the principle of energy cascade utilization,solar energy can provide heat for methane reforming,and the hydrogen produced by the reaction can be used for fuel cell power generation.The integration of solar thermochemical energy storage,efficient and clean hydrogen production and power generation technology can be realized,and the transmission and transformation of solar energy-hydrogen energy-electric energy-user can be realized.This paper focuses on solar collector,methane hydrogen production in membrane reactor and fuel cell hybrid power system.The specific contents and conclusions are as follows:(1)The models of membrane reactor reforming for hydrogen production and fuel cell are established by Aspen Plus software,and the effects of palladium membrane,reaction steam-carbon ratio and reaction temperature on the composite system of membrane reactor reforming for hydrogen production and fuel cell are analyzed.The simulation results show that when the reactant conversion rates of the membrane reactor and the conventional reactor are the same,the palladium membrane reactor can lower the reaction temperature,or at the same reaction temperature,the palladium membrane reactor can increase the methane conversion rate.When the reaction temperature is 500℃ and the steam-carbon ratio is 2.5,it is helpful to the methane reforming reaction in the membrane reactor.(2)According to the change of DNI in Lhasa on a certain day,the heat available for solar energy collection by trough collector is calculated,and the solar energy with the external heating form is input into the above mentioned hybrid system.According to the simulation data,the performance indexes such as methane conversion rate,H2 yield,battery power and voltage,and the efficiency of solar energy conversion to hydrogen energy are calculated.The results show that when the DNI changes from 10:00 am to 20:00 pm on a certain day,the voltage output changes in the range of 0.72～0.74V,and the battery output power is 120kW.From 10:00 am to 19:00 pm,the maximum conversion efficiency of solar-chemical energy can reach 0.265,and the maximum power generation efficiency of the system is 0.370.On this day,24.53 kmol hydrogen or fuel cell can be obtained,which can provide the electricity of 1440.556 kW·h.(3)In order to ensure that both the methane conversion rate and the system exergy efficiency in the solar thermal reforming hydrogen production are high,the trough collector is calculated to collect the heat energy available for solar energy according to the change of DNI on the typical day of Lasa four seasons,and the methane inlet flow is continuously regulated.The results show that when the exergy efficiency reaches 80%,the methane inlet mole flow reaches the highest value of 2.5 kmol/h in summer,0.7 kmol/h in spring and 1.8 kmol/h in autumn,In the winter solstice,due to the low overall DNI,when the exergy efficiency reaches 70%,the maximum methane import volume can reach 0.12 kmol/h.(4)The reactor structure is designed,and the experimental platform for hydrogen production from methane steam reforming in membrane reactor is built.According to the simulation conditions,both the reaction temperature and the reactant water carbon ratio are set to carry out the experiment.According to the experimental data,the methane conversion rate and other performance indicators are calculated,and the same performance indicators in the simulation are compared to evaluate the feasibility of the simulation system.The results show that when the steam-carbon ratio is 2.5 and the temperature is 500℃,the methane conversion rate is 0.73.In specific experiments,the steam-carbon ratio of 2.5 is more conducive to methane reforming reaction.The relative error between the experimental data and the simulation data is within 8%,so the proposed hybrid system model is verified to be feasible.This paper provides methods and ideas for the research of solar thermal reforming hydrogen production and fuel cell system,lays the foundation for the integration of methane reforming trough solar collectors in the future,and provides theoretical support for the subsequent research on solar thermal utilization.