Performance improvement of the combined cycle power plant by intake air cooling using an absorption chiller

This paper studies how to improve the capacity of the combined cycle (CC) power plant which has been operated for 8 years. The most popular way is to lower intake air temperature to around 15 °C (ISO) and 100% RH before entering the air compressor of a gas turbine (GT). Thailand has 3 seasons: winter, summer and rainy season. According to 2003 Bangkok monthly weather data, all year ambient temperature is higher than 15 °C. This research proposes a steam absorption chiller (AC) to cool intake air to the desired temperature level. It could increase the power output of a GT by about 10.6% and the CC power plant by around 6.24% annually. In economic analysis, the payback period will be about 3.81 years, internal rate of return 40%, and net present value 19.44 MUS$.