The Performance Improvement In Garri Combined Cycle Power Plant By Inlet Air Media Type Evaporative Cooling

Abstract

The Gas turbine performance is highly sensitive to the compressor inlet temperature. In Sudan the output of gas turbine falls to a value that is less than the rated output under high temperature conditions. The solution of this problem is important because the peak demand season in Sudan happens in the summer. One of the convenient methods of inlet air cooling is evaporative media type which appropriate for hot and dry weather. As the gas turbine and combined plants in Sudan installed in such ambient conditions, therefore this method can be used to improve the performance of gas turbine and combined cycle plants. This thesis focuses on performance improvement of a Gas turbine and combined cycle power plant by air inlet media type evaporative system cooling. By application of media cooling system in Garri combined cycle power plant, in eight frame 6 gas turbines. The performance test results show that the power out of frame 6 gas turbines, (GT1 to GT8) increased by 4.4MW (14%), 5.7MW (18%), 2.1MW (6.8%), 4.5MW (15%), 4.3MW (15%), 4MW (13), 4.1MW (14%) and 3.4MW (10%). And also steam turbines 1 to 3 increased by 1MW and steam turbine 4 increased by 0.5MW. The heat rate for gas turbines decreased by 3.7%, 7.2%, 3.9%, 6.4%, 4%,3.3%,2.3% and 2.4%. Also the efficiency of gas turbines increased by 1%, 2.2%, 1%, 2%, 1.4%, 1 %, 0.6% and 1%. iv According to the economical calculations in this thesis the pay back period is estimated to be 0.23 year (2.8 months) for the evaporative cooling system, the study in this research has shown that the media type evaporative cooling system is suitable for the dry and hot climate like Sudan for gas turbine power enhancement.