The effect of parallel hot windbox repowering on 387 MW fossil fuel power plant

The paper presents the concept of repowering in existing power plant. Among technologies for existing steam power plants, the hot windbox repowering is the fastest way to respond to the energy demand, improve efficiency and reduce the pollutants emissions. Thermodynamic analysis of power plant model with fossil boiler before and after hot windbox repowering, has been investigated using commercial software. The purpose of this work is to understand and analyze the effect of hot windbox repowering on 387 MW fossil fuel power plant as well as the effect of additional heat exchangers, which have been installed parallel with regeneration system to use the heat of boiler exhaust gases. In this way, after repowering the summary power of power plant in base load is 615 MW, which has been reached adding gas turbine (176.9 MW). To analyze the model, calculations were performed in 3 stages: 1) calculation and comparison of the thermodynamic parameters as well as carbon dioxide emissions of power plant model before and after repowering, 2) analysis of the optimal value of feed water mass flow through heat exchangers installed after economizer, 3) calculation of thermodynamic parameters in values 100%, 90%, 80% and 75% of fossil boiler heat loads.