PERFORMANCE MODELING OF UNFIRED STEAM CYCLE USING SINGLE DUAL PRESSURE ONCE-THROUGH STEAM GENERATOR

摘要

The high thermal efficiency and the use of low carbon content fuel (e.g., natural gas) have made the Combined Cycle Power Plant (CCPP) one of the best choices for power generation due to its benefits associate with low cost and low environmental impact. The performance of Unfired Steam Cycle (USC) as a part of the CCPP has significant impact on the performance of the whole power plant as it provides the CCPP with around one third of the total useful power. An accurate performance simulation of the USC is therefore necessary to analyze the effects of various operating parameters on the performance of combined cycle power plant. In this paper, a performance simulation approach for an unfired steam cycle using single and dual pressure-level of an OTSG is presented. The developed modeling method has been applied to the performance simulation of an existing unfired steam cycle power generation unit installed at Manx Electricity Authority and the results are promising. A comparison between simulated and actual performance at design and off design operating conditions of the same USC has shown a remarkable agreement with errors values below 1 %.