Thermodynamic modelling and optimization of a dual pressure reheat combined power cycle

摘要

Heat recovery steam generator (HRSG) plays a key role on performance of combined cycle (CC). In this work, attention was focused on a dual pressure reheat (DPRH) HRSG to maximize the heat recovery and hence performance of CC. Deaerator, an essential open feed water heater in steam bottoming cycle was located to enhance the efficiency and remove the dissolved gasses in feedwater. Each of the heating section in HRSG is solved from the local flue gas condition with an aim of getting minimum possible temperature difference. For high performance, better conditions for compressor, HRSG sections, steam reheater and deaerator are developed. The CC system is optimized at a gas turbine inlet temperature of 1400°C due to the present available technology of modern gas turbine blade cooling systems. The exergetic losses in CC system are compared with each other. The present DPRH HRSG model has been compared and validated with the plant and published data.