A Study on Optimal Repowering System of Recombustion Type

Abstract

The repowering which is combined gas turbine to the used fossil power plant has an increasing effect of electric power supply and the thermal efficiency of power plant. In the repowering, the question now arises the more increasing parts of power plant remodels the more increasing cost of repowering.
This paper is proposed a repowering system of recombustion type with minimized parts of power plant remodels and high thermal efficiency of total power plant system. The optimal repowering system is maximized performance index represented a thermal efficency of the repowering system. The system is satisfied with the constraint for operating the repowering plant. And we proposed the optimization for quantity of heat transfer at each parts of the boiler by the burner combustion control of upper and under stage for less remodeling parts of the power plant.
A result of analysis, this repowering system has higher thermal efficiency of total fossil power plant system in spite of minimum parts of plant remodels. This system has an advantage to cost performance, and it will be applied the repowering to used fossil power plants extensively.