脉冲放电NO脱除过程模拟

Simulation of NO removal by using pulsed discharge

建立了数学模型,把所考虑的NO/N2/O2/H2O脉冲放电体系中的主要化学反应,归结为各物种浓度的刚性常微分方程组的初值问题来求解,计算方法选用Rosenbrock法,得到了物种浓度随停留时间的演化规律。结果表明:NO还原和氧化在其脱除过程中同时共存,当NO,N2,O2,H2O和CO2的体积浓度分别为200×10-6,80%,5%,6%和9%时,NO氧化所占的比例比NO还原的大很多;脉冲频率增大导致NO还原率和氧化率均增大;H2O浓度增大导致HNO3浓度增大,表明NO氧化所占的比例随H2O浓度增大而增大。

A mathematical model was developed to describe the behavior of species in pulsed discharge of the NO/N2/O2/H2O system, and to compute the generation of the species by considering a serious of chemical reactions in the pulsed discharge into stiff ordinary differential equations. The equations were numerically solved with the Rosenbrock method and the evolution of various species produced in the NO/N2/O2/H2O system as a function of residence time was studied. The results showed that NO reduction and NO oxidation coexisted in one NO removal process. The proportion of NO oxidation was much bigger than that of NO reduction, when the concentrations of NO, N2, O2, H2O and CO2 were 200 × 10^-6, 80%, 5%, 6% and 9% respectively. Both NO reduction efficiency and NO oxidation efficiency increased with increasing pulsed discharge frequency. The concentration of HNO3 increased with increasing concentration of water vapor, indicating that the proportion of NO oxidation increased with increasing concentration of water vapor.