给水加热型联合循环的变工况性能

在联合循环改造的各种方案中,给水加热型具有投资少、改动少、耗用优质燃料较少、尤其是简单易行及技术难度小等特点,因此在我国现有的技术经济水平、特别是以煤为主的国情下,有一定应用市场。本文分析比较了多种变工况运行方式的性能及可能出现的问题,并在此基础上提出综合性能较好的运行模式。

OFF-DESIGN PERFORMANCE OF FEEDWATER HEATING COMBINED CYCLE

Among various CC-Repowering schemes, feedwater heating combined cycle is the simplest and most reliable one with lowest technical difficulty and investment, and thus is believed to be the suitable repowering method at present for China and other developing countries with similar national conditions. The off-design performances of feedwater heating combined cycle are discussed in this paper. Several specific operating scenarios with varying power output are available for the off-design operation: both gas turbine and steam turbine run in the part load condition while maintaining the heat balance in the feedwater heating unit; gas turbine load is reduced while steam turbine load maintains unchanged until the former one reaches a certain point or alternatively, steam turbine runs with a falling load while gas turbine maintains operation at full load, etc. The performances of different operating scenarios are analyzed and compared and better scenario is recommend accordingly.