H_2／空气CSTR双稳定状态及点火过程的基元反应模拟

Simulation of the Bistable States and Ignition in an H_2/Air CSTR with Detailed Chemistry

利用基元反应机理数值模拟了H2／空气良好搅拌反应器(CSTR)系统的双稳定状态和点火过程．在入口温度较低时,系统在低流量和高流量时都存在一个熄火极限．在着火极限流量范围内,既存在一个高温稳定状态(着火状态),还存在一个略高于入口温度的低温稳定状态,具有双稳定状态．随着入口温度的增加,CSTR系统低流量的低温稳定状态会消失．在双稳定条件下,系统的最终状态取决于系统初始填充空气的温度．当该温度高于点火温度时,系统处于高温稳定态;低于点火温度时,系统则处于低温稳定态．点火温度与系统压力的关系为典型的“Z”型曲线．

The bistable states and ignition in an H2/air CSTR （continuous-flow stirred tank reactor） are numerically simulated based on the detailed chemistry. Under the condition of low inlet temperature, there are extinguish limits at the low flow rate and the high flow rate respectively. Within combustible limits of flow rates, the system has two stable states ： high temperature state （ burning state）, and the low temperature state. The low-temperature stable state at low flow rate will disappear with increase of inlet temperature. In bistable states, the final states of system are determined by the temperature of initial filling air of the system. If the temperature is higher than the ignition temperature, the system stabilizes at the high temperature. Otherwise, it stabilizes at low temperature. The relation between ignition temperature and pressure in a CSTR system is a typical ＂Z＂ curve.