考虑化学反应强耦合的植被火焰条件下直流间隙多物理场耦合模型

Multi-physical-field Coupling Model of DC Gap Under Vegetation Flame Condition Considering Strong Coupling of Chemical Reaction

为分析电场、温度场与燃烧化学反应的相互作用,更准确地模拟植被火焰条件下间隙带电粒子分布情况,建立了考虑化学反应强耦合的植被火焰条件下直流间隙多物理场耦合模型。并通过植被燃烧试验的结果对模型关键参数进行设置,利用模型仿真分析了不同极性电压、电极高度对带电粒子分布特性的影响及带电粒子对背景电场的影响。结果表明:该文试验条件下,松木热解反应方程系数修正为C_(10)H_(14)O_(6)→4C+3CO+CO_(2)+2CH_(4)+2H_(2)+H_(2)O、热解反应速率为2.4×10^(–8)mol/(m^(3)·s)时,仿真与试验结果最为接近;随着电极高度的降低,电极附近与电极极性相异的带电粒子浓度由10^(–9m)ol/m^(3)增加至10^(–8)mol/m^(3),变化趋势与泄漏电流相似;带电粒子对正电极附近初始背景电场的影响效果大于负极性,正电极附近背景电场的增幅为70%~110%,负电极附近则增大了40%~80%。

In order to analyze the interaction between electric field,temperature field and chemical reaction of combustion,and to accurately simulate the distribution of charged particles in the gap under the condition of vegetation flame,this paper establishes a DC gap multi-physical-field coupling model in which the strong coupling of chemical reaction under the condition of vegetation flame is taken into account.The key parameters of the model are set according to the results of vegetation burning test.The effects of different polarity voltages and electrode heights on the distribution characteristics of charged particles and the effects of charged particles on the background electric field are analyzed by using the model simulation.The results show that,under the test conditions,when the coefficient of the pyrolysis reaction equation of pine is modified to C_(10)H_(14)O_(6)→4C+3CO+CO_(2)+2CH_(4)+2H_(2)+H_(2)O and the pyrolysis reaction rate is 2.4×10^(–8)mol/(m^(3)·s),the simulation results are the closest to the test results.With the decrease of electrode height,the concentration of charged particles with different polarity near the electrode increases from 10^(9)mol/m^(3)to 10^(–8)mol/m^(3),which is similar to the leakage current.The effect of charged particles on the initial background electric field near the positive electrode is greater than that of the negative electrode.The increasement of the background electric field near the positive electrode is 70%~110%,and the increasement of the background electric field near the negative electrode is 40%~80%.