暖风器与低温省煤器联合系统变参数热力特性模拟

Simulation on variable parameter thermal characteristics of the combined system of air heater and low temperature economizer

针对电站锅炉排烟温度高、排烟热损失大的问题,以某亚临界330 MW机组为例,采用Ebsilon软件建立了包含锅炉、汽轮机和发电机的完整模型;在此模型基础上对常规低温省煤器和暖风器与低温省煤器联合系统进行了热力特性模拟,着重分析了设计不同的暖风器出口风温时,联合系统的特性变化,及其对汽轮机热耗率、锅炉效率、发电煤耗、辅机功耗和供电煤耗的影响。结果表明:暖风器与低温省煤器联合系统具有较大的节能潜力,与常规低温省煤器系统相比,联合系统可多节煤0.5~0.9 g/(k W·h);设计不同的暖风器出口风温时,供电煤耗降幅随风温升高而增加,但风温升高至一定程度后,节能量不再变大。

Aiming at solving the problem of high boiler exhaust gas temperature and large exhaust heat loss in power plants,taking a 330 MW subcritical unit as an example,a complete system model including boiler,steam turbine and generator is set up using the Ebsilon software.Based on this model,thermal characteristics simulation is conducted on the combined system of normal low temperature economizer and the combined system of air heater and low temperature economizer.The characteristics of the combined system is analyzed with different air heater outlet temperatures,and the effects of air heater outlet temperature on turbine heat rate,boiler efficiency,power generation coal consumption,auxiliary power consumption and power coal consumption are also analyzed.The results show that,the combined system of air heater and low temperature economizer has great potential in energy saving.The combined system can save more 0.5~0.9 g/(kW·h)of coal than the normal low temperature economizer.When designing the temperature of the air heater outlet,the decrease of power coal consumption increases with the air heater outlet temperature.However,when the temperature goes up to a certain extent,the energy saving capacity no longer increases.