Simulation analysis of microchannel type ammonia cracking reactor for hydrogen production
In order to optimize the performance of the microchannel type ammonia cracking reactor for hydrogen production,a three-dimensional steady-state multi-physical field coupling numerical model is established.The distribution of velocity,density,temperature,concentration and reaction rate in the reactor,as well as the effects of flow channel length and operating conditions on the NH3 conversion rate are simulated and studied.The velocity of fluid increases and the density decreases from the inlet to the outlet along the flow channel as the reaction proceeds.The temperature and concentration gradients are the most pronounced near the inlet,the ammonia cleavage reaction is mainly concentrated in the first half of the microchannel.Under the baseline conditions(temperature 773 K,pressure 101.325 kPa,and flow rate 400 mL/min),at least 80%of NH3 is cracked within 50%of the length from the inlet.Increasing the flow channel length and the temperature,decreasing the flow rate and the pressure can increase the NH3 conversion rate,the effect of temperature is the greatest.When the temperature T≥823 K,the NH3 conversion rate can reach 83.79%,even if the flow rate reaches 800 mL/min and the pressure is 0.7 MPa.
ammoniahydrogen productionmicrochannelnumerical simulationheat transfermass transfer
万方数据
维普
