环境温度对热电联产机组的影响及对策

Effect of environmental temperature on cogeneration units and the countermeasures

针对热电联产机组冬季存在空冷凝汽器冻结和供热抽汽参数调节滞后的问题,结合某4×220MW直接空冷热电联产机组进行了热力计算,得出不同环境温度对应的凝汽器最小蒸汽流量和供热抽汽流量,并利用origin软件绘制出相应的性能曲线。通过分析发现:随着环境温度升高,流入凝汽器的蒸汽量逐渐降低,并且蒸汽量的变化率逐渐减小;当环境温度低于零下5℃时,基本热网加热器已经达到最大热负荷,需要启动尖峰热网加热器以满足热用户的需求;当环境温度低于零下6℃时,所需总蒸汽流量已经超过最大主蒸汽流量,此时需要加大燃料投入,增大主蒸汽流量,或关闭部分空冷凝汽器单元,减小发电量。该方法能够准确计算不同温度对应的热电比例,及时调整发电和供热参数,实现能量的合理利用。

Against such problems as frozen in air cooled condenser and lag in heat supply extraction parameter adjustment that occurred on cogeneration units in winter,a model was established to conduct thermal dynamic calculation,combining with a 4×220 MW direct air cooled cogeneration uni.The minimum condenser steam flow and heat supply extraction flow under different environmental temperatures were obtained,and the origin software was employed to draw the corresponding performance curves.The results showed that,with an increase in the environmental temperature,the steam amount required by condenser reduced and the variation rate of the steam flow decreased gradually.When the environmental temperature was lower than-5 ℃,the basic heater had reached the maximum heating load,peak-load heater should be started to satisfy the heat users.When the environmental temperature was below-6 ℃,the required total steam amount had exceeded the maximum steam amount,so fuel input should be increased to improve the main steam amount or part of the condenser units should be shut down to reduce power generation.This method can calculate the heat/electricity ratio at different environmental temperatures correctly and regulate the parameters of power generation and heat supply timely to realize the reasonable utilization of energy.