煤化学链燃烧颗粒流动反应的数值模拟

Numerical Simulation on Particle Flow and Reaction of Chemical Looping Combustion of Coal

针对化学链燃烧气固反应速率的影响因素复杂未知的问题,本文建立了碳粒与CaSO4载氧体颗粒在水蒸气气氛下的数理模型,并利用Fluent进行数值计算,从微观上分析了温度和压力的改变,对颗粒间化学链燃烧反应速率、CO2生成速率以及载氧体表面固相生成物沉积速率的影响。分析结果表明,提高反应器内的温度和压力,均加快了CaSO4载氧体颗粒表面CaS的沉积速率,且压力的提高在很大程度上促进了沉积速率的增加,而沉积覆盖在载氧体表面上的CaS导致了反应速率的下降。该研究有利于高纯度CO2气体的捕集,从而达到减排的目的,对化学链反应速率的控制具有重要意义。

Since the influence on gas-solid reaction rate of chemical looping combustion was unclear, the gas-solid flow reaction between carbon particle and CaSO4 Oxygen Carrier particle under steam atmosphere was studied in this paper. Based on the Fluent calculation, the varied temperature, pressure influenced on the CLC reaction rate, CO2 production rate and CaS deposited rate on the OC particle surface. The analysis results show that, with the rising of temperature and pressure in reactor, the deposition rate of CaS on CaSO40C particle surface was accelerated, and the increase of pressure largely contributed to the increas- ing of deposition rate. However, the CaS that deposited on the OC surface led to the decline of reaction rate. The study is conducive to the collecting of high purity CO2 gas, so as to achieve the goal of emission reduction. And also it is significant to the control of chemical looping reaction rate.