提高蒸汽初参数是提高机组热经济性的一个重要途径，在亚临界机组主蒸汽、再热蒸汽温度提升条件下，文章以300 MW等级亚临界机组为例，对现有加热器的换热能力进行计算分析，在充分发挥其换热能力基础上，对回热抽汽参数进行优化设计，合理分配各段抽汽参数，避免了四台加热器的更换；就抽汽参数优化对汽轮机热耗率的影响进行了定量计算。通过回热抽汽参数优化设计，减少项目投资六百余万元，降低汽轮机热耗率千分之一点七二，取得了明显的经济效益。

Increasing steam parameters is an important way to improve unit thermal economy. With the steam parameter rising of subcritical unit, the capacity of heat exchange was designed though calculation and analysis. With the maximum of heat-exchange, the parameters of regenerative extraction steam were further optimized, and each and every parameter of regenerative extraction steam was reasonably re-distributed. As a result, the replacement of four heaters was avoided. The effect of extraction parameters optimization on the heat rate of steam turbine was calculated quantitatively. Finally, more than six million Yuan of project investment was saved, and the heat rate of steam turbine was reduced by 1.72‰.

TK262