燃煤发电机组深度调峰运行的能耗特性分析

Energy Consumption Characteristics Analysis on a Coal-Fired Power Plant Operating in Deep Peaking Mode

随着我国可再生能源发电装机容量的增长,越来越多的火电机组将承担深度调峰任务。因此,需要开展火电机组低负荷能耗特性的研究。文章以某350 MW机组为例,建立了机组变工况计算模型和分析模型,对机组超低负荷运行的能耗特性进行了预测。计算结果表明,随着机组负荷的下降,机组发电标准煤耗率逐渐增大,在机组负荷分别为50%、40%、30%、20%时,发电标准煤耗率较100%负荷分别增加了15.90、25.81、42.32、70.43 g·(k W·h)-1。分析结果表明,机组低负荷运行时,锅炉子系统、汽轮机子系统效率均显著下降。

With the increasing of installed power capacity from renew able energy,more and more thermal power plants are subject or serve the deep load cycling. Therefore,it is needed to study the energy consumption characteristics of power plants under ultra-low load. Taking a 350 MW unit as example,this paper establishes the calculation models of off-design conditions and exergy analysis model for units,and predicts the energy consumption characteristics of power plants under ultra-low load. The results show that the standard coal consumption rate for power generation increases with the decreasing of power load. The standard coal consumption rate for power generation are increased by 15. 90,25. 81,42. 32 and 70. 43 g ·（ k W·h）-1w hen the load ratios are 50%,40%,30% and 20% compared with that when the load ratio is 100%,respectively. The results of exergy analysis show that the exergy efficiencies of boiler subsystem and turbine subsystem all decrease significantly when the power plant operates under low load ratio.