Effect of Ambient Air Temperature on the Performance Factor of a Combined Cycle in Garri Power Plant

Abstract

The Combined cycle (Gas/Steam) Performance is highly sensitive to the Ambient Air temperature. Sudan is one of the countries which have high ambient air temperature and low humidity. As a result, power output from combined cycle decreases and the specific fuel consumption increases. When there is high power demand needed especially during summer season and the high price of fuel (light diesel oil).This problems can be avoided by cooling compressor inlet air temperature. By application of media cooling system (evaporative) in Garri Combined cycle. The ambient air temperature decreased 38% for Gt7 & 31% for Gt8. The performance test result show that the Compressor Specific work decreased by 1.15% for Gt7 & 2.9% for Gt8, Specific Net work increased by 1.15% for Gt7 & 2.9 for Gt8, power output increased by 11% for Gt7 & 8.8% for Gt8, Specific fuel consumption decreased by 1.8% for Gt7 & 3.3% for Gt8, Fuel saving equal 0.22% forGt7 & 0.29% for Gt8, Gas turbine Efficiency increased by 0.62% for Gt7 & 0.92% for Gt8, Exhaust flow rate increased by 7.9%, Steam turbine pressure increased by 4.5%, Steam turbine power output increased by 2.2%, and Combined cycle Efficiency increased by 0.06%.