Efficiency of steam reheating in heat recovery steam generator at thermal power plant with gas turbine topping

Olga Romashova,Aleksandra Katalevskaya,Aleksandr Tubolev,Aleksandr Minor,Vladimir Martyshev,G.V Kuznetsov,A.O Zhdanova

doi:10.1051/matecconf/201711001054

Olga Romashova, Aleksandra Katalevskaya + Show 5 more

Open Access

https://doi.org/10.1051/matecconf/201711001054

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Abstract

Possibility of using alternative option to the displacement of regenerative heating is analyzed in this paper: application of heat recovery steam generator’s (HRSG) thermal power for reheating of working medium that has passed steam turbine.

Highlights

Technical re-equipment and modernization of existing Thermal Power Plants (TPPs) with implementation of combined-cycle technologies lead to significant reduction in specific consumption of reference fuel for electricity generation
Thermal efficiency of CCPP schemes with displacement of steam reheating and regenerative heating from steam-turbine part for different options of heat recovery steam generator (HRSG) heat application is compared: scheme 1 (Fig. 1) - displacement of steam reheating from steam boiler; scheme 2 (Fig. 2) - partial displacement of regenerative heating (high-pressure heaters (HPHs)); scheme 3 (Fig. 3) - displacement of steam reheating with partial displacement of regenerative heating; scheme 4 (Fig. 4) - complete displacement of regenerative heating
To sum up: - displacement of HPH from steam turbine plant leads to an increase of heat losses in condenser by 24% compared with initial scheme of STP; complete replacement of regenerative heating increases losses by 50%

Summary

Introduction

Technical re-equipment and modernization of existing Thermal Power Plants (TPPs) with implementation of combined-cycle technologies lead to significant reduction in specific consumption of reference fuel for electricity generation. Schemes with heating of feed water and condensate in HRSG are most widespread and have been called GT topping with displacement of regenerative heating [5-7]. Disadvantage of such modernization for TPPs is a significant deterioration of steam turbine plant (STP) thermal efficiency: the share of heat losses in condenser increases, consumption of main. Possibility of using alternative option to the displacement of regenerative heating is analyzed in this paper: application of heat recovery steam generator’s (HRSG) thermal power for reheating of working medium that has passed steam turbine

HRSG options for displacing steam reheating and regenerative heating

Results of calculations

Choice of the optimum steam reheating pressure in the HRSG

Conclusion