中压供汽对350 MW超临界机组经济性的影响

Influence of medium pressure steam supply on economy of 350 MW Supercritical Units

某电厂350 MW超临界机组采用再热蒸汽作为工业用汽汽源,运行时发现机组煤耗不降反升。本文分别从设计工况图、现场试验两方面分析该机组中压供汽后煤耗变化趋势及影响因素。发现中压供汽在机组实际运行时偏离设计工况而导致中低压缸效率降低较多,超过中压供汽热电联产的收益。同时本文进一步将分析方法推广得到中压供汽机组热电联产的临界条件,为同类机组经济性分析提供重要的借鉴意义。

A 350 MW supercritical unit of a power plant uses reheated steam as the industrial steam source.During operation,it is found that the coal consumption of the unit does not decrease but rises instead.This paper analyzes the change trend and influencing factors of coal consumption of the unit after medium pressure steam supply from two aspects of design condition diagram and field test.It is found that the medium pressure steam supply deviates from the design condition during the actual operation of the unit,which leads to a large reduction in the efficiency of the medium and low pressure cylinder,which exceeds the profit of the medium pressure steam cogeneration.At the same time,the analysis method is further extended to obtain the critical conditions of cogeneration of medium pressure steam supply units,which provides important reference for the economic analysis of similar units.