大型空冷机组高背压供热运行特性分析

Analysis on operation characteristics of high back-pressure heating for large air-cooling units

直接空冷机组高背压供热可减少机组采暖抽汽,增加机组发电能力,而且能回收乏汽余热,增大机组的供热能力。为了探讨空冷机组高背压供热改造后的运行特性,进一步挖掘机组的节能潜力,以300 MW直接空冷机组为例,基于供热机组变工况理论和矩阵分析法建立高背压供热理论模型,分析环境温度变化对高背压供热机组性能的影响规律。结果表明:提高背压,可增大机组的供热能力;随着环境温度的升高,机组最佳运行背压呈下降的趋势;高背压供热机组按最佳运行曲线运行时的发电功率更大,节能效果更显著。本文研究结果可为机组在供热期的经济运行提供理论依据。

The utilization of high back-pressure heating of the direct air-cooling unit can not only reduce heating steam extraction to promote the power generation capacity, but also recycle steam exhaust waste heat to enhance the heating capacity of the unit. In order to discuss the operating characteristics of the air-cooling unit with high back-pressure heating and further enhance the energy saving potential of the unit, taking the 300 MW direct air-cooling unit as an example, the theoretical model of high back-pressure heating is established based on the theory of variable working conditions of the heating unit and matrix analysis method. The effect of the environmental temperature changes on the performance of high back-pressure heating unit is analyzed. The results indicate that increasing the back pressure can increase the heating capacity of the unit. The back pressure of the unit＇s optimal operation has a decreasing tendency with the rising of environmental temperature. When the high back-pressure heating unit is operated according to the optimal operation curve, the power generation is greater and energy saving effect is more significant. This study provides a theoretical basis for the economic operation of the unit during the heating period.