富氧燃烧循环流化床机组热力特性分析及优化

Thermodynamic characteristics analysis and optimization of oxyfuel combustion circulating fluidized bed unit

为获得富氧燃烧循环流化床(CFB)发电机组热力特性参数随运行参数的变化规律,以内蒙古某亚临界CFB发电机组为研究对象,建立富氧燃烧CFB发电机组流程仿真模型,对氧气纯度、氧气浓度(体积分数)、过量氧气系数及漏风系数等单因素对发电系统整体能耗的影响进行了研究。结果表明:随着氧气纯度、氧气浓度的增大,机组供电标准煤耗先减少后增大,机组净电效率先增大后减小;随着过量氧气系数、漏风系数的增大,供电标准煤耗增大,净电效率减小;富氧燃烧CFB发电机组在氧气纯度为96%、氧气浓度为30%、过量氧气系数为1.05、漏风系数为0.01时,供电标准煤耗为417.60 g/(kW·h),净电效率为29.42%,是采用单因素分析法考察的所有工况中最优组合方案。

In order to obtain the variation law of thermodynamic characteristic parameters of oxyfuel combustion circulating fluidized bed(CFB)generator set with operation parameters,a process simulation model of oxyfuel combustion CFB generator set was established by taking a subcritical CFB generator set in Inner Mongolia as the research object.The influences of single factors such as oxygen purity,oxygen concentration,excessive oxygen coefficient and air leakage coefficient on overall energy consumption of the power generation system was studied.The results show that,with the increase of oxygen purity and oxygen concentration(volume fraction),the standard coal consumption of power supply decreases at first and then increases,and the net electric efficiency increases at first and then decreases.With the increase of excessive oxygen coefficient and air leakage coefficient,the standard coal consumption of power supply increases and the net electricity efficiency decreases.The power supply standard coal consumption reaches 417.60 g/(kW·h)and the net power efficiency reaches 29.42%when the oxygen purity is 96%,the oxygen concentration is 30%,the excessive oxygen coefficient is 1.05 and the air leakage coefficient is 0.01,this condition is the optimal scheme in all the conditions observed using the single factor analysis method.