Exergy Analysis of a Sponge Coke Fired Circulating Fluidized Bed Power Plant: A Case Study of Garri 4 Power Plant

Abstract

Fossil fuel is the dominant energy source worldwide accounting for 80 % of total energy sources, 18 % of it is being used for electricity generation which made the search for improvement opportunities in order to optimize the design and operation condition essential. The present work aims to analyze the performance of Garrri 4 power plant (110 MW); a sponge coke fired circulating fluidized bed power plant in order to define improvement opportunities magnitude and location. The system was analyzed using Energy and exergy analysis at three different loads 29.32 MW, 45MW and 47 MW in term of key performance parameter. The energy analysis revealed the boiler as the main source of exergy destruction accounting for 85.59%, 85.29 and 75% from the total exergy destruction, and the heaters as having the highest exergetic efficiency ranging from (73.25- 99.6)% (74.6 - 95.29)% and (55- 98.9)% followed by the steam Turbine having 69.27%,72.29% and 76.10% all for the sited loads respectively. A general improvement in the plant exergetic efficiency is observed when shifting toward the plant’s rated load from 21.79%, 23.72% till 26.27% for the studied loads respectively accompanied by a slight reduction in exergy destruction associated with the generation of 1MW of electricity from 10.92 MW, 9.97 MW and 9.85 MW respectively.