Thermodynamic modelling and simulation of advanced combined cycle for performance enhancement

Abstract

This paper deals with the development requirements of a gas—steam combined cycle power plant with the aim to achieve plant efficiency in excess of 62 per cent through various possibilities of performance enhancement in topping cycle and bottoming cycle. For this study, the reference-combined cycle configuration (MS9001 series) power plant of General Electric has been considered. The innovation possibilities include the increase in rotor/turbine inlet temperature; development of advanced high-temperature blade material with superior thermal barrier coatings; advanced inlet duct and compressor inlet design to minimize loss; improved individual component efficiencies; improved turbine blade cooling techniques; better blade cooling mediums; incorporating intercooling and reheat either separately or in combination with the simple gas turbine cycle using higher cycle pressure ratio; improved gas turbine exhaust heat utilization in the heat recovery steam generator, minimize stack gas temperature; as well as best shaft system configuration. This study quantifies each of these development possibilities and shows that on incorporating these factors in the reference cycle it could offer the combined cycle plant efficiency above 65 per cent.