Exergy Analysis for Performance Optimization of a Steam Turbine Cycle

Abstract

Exergy analysis of a 500 MWe steam turbine cycle is performed to identify the components that offer significant work potential saving opportunity. Criteria of performance relevant to the individual components are formulated. Exergy flows, exergy consumption due to irreversibilities and rational performance parameters for the turbine cycle and its components are computed by using plant operation data under different conditions. Energy efficiency of the turbine cycle is low due to large energy rejection, but the derived exergy efficiency of the turbine cycle is high due to low exergy rejection from the cycle. Part load operation exhibits lower energy efficiency due to higher energy rejection relative to net output. On the contrary, exergy rejection from the cycle relative to net output does not increase during low load operation. Results show that poor part load exergy efficiency is due to higher exergy destruction relative to net output. Higher pressure feed heaters deal with larger exergy and therefore, need more attention to improve cycle efficiency. Operation and maintenance decisions based on exergy analysis have proved to be more effective in reducing inefficiencies in operating power plant. Exergy-based approach of performance analysis will help practicing power engineers manage energy resources and environment better.

Thermodynamic analysis of a coal-fired power plant repowered with pressurized pulverized coal combustion

“…Validation of the software ‘Cycle-Tempo’ was carried out by simulating the steam cycle of a 500 MWe power plant reported by Ray et al [10]. The results are presented in Table 2 and it is observed that the simulation results (stream flow data) are very close to the corresponding operational values, with a maximum deviation of about 3.5 per cent.…”

“…Rosen [9] compared the performance of an operating coal-fired power plant and a nuclear power plant using a process simulator, Aspen Plus. Exergy analysis was used to obtain the insights into the turbine cycle performance by Ray et al [10]. The effects of altering excess combustion air and stack-gas temperature on the overall plant energy and exergy efficiency was reported by Rosen and Tang [11].…”

Thermodynamic and economic analysis of performance evaluation of all the thermal power plants: A review

“…As it was mentioned, several studies have been conducted on both energy and exergy analyses of power plants with different capacities working based on coal firing. 14,[98][99][100] In a steam power plant, both exergy and energy were analyzed. 101,102 Vandani, Bidi, and Ahmadi.…”

Modelling and Assessment of Effect of Operation Parameters on Gas Turbine Power Plant Performance using First and Second Laws of Thermodynamics

“…In recent years, numerous and extensive researches have been conducted to evaluate thermal power systems from both energy and exergy analyses point of view (Bilgen, 2000;Ray et al, 2007;Khaldi and Adouane, 2011;Chen et al, 2014;Soltani et al, 2015;Martin et al, 2016;Ganapathy et al, 2009;Egware and Obanor, 2013b;Ahmadi et al, 2011). Table 1 shows the brief summary of studies on proportion of exergy destruction in various components of thermal plant by different authors and year of study.…”