Performance improvements of the intercooled reheat recuperated gas-turbine cycle using absorption inlet-cooling and evaporative after-cooling

Inlet air-cooling improves both efficiency and power of gas-turbine cycles. An absorption inlet-cooling system is introduced to the intercooled reheat recuperated gas-turbine cycle (I cycle). The exhaust gas of the cycle is used to run the system, which cools the inlet air to the low-pressure compressor and high-pressure compressor using two stages of cooling in the intercooler. Five different layouts of the I cycle are presented. Those layouts include the effects of absorption inlet cooling, evaporative inlet cooling, evaporative aftercooling, and absorption inlet cooling with evaporative aftercooling. A parametric study of the effect of pressure ratio, ambient temperature, ambient relative-humidity, turbine's inlet-temperature (TIT), and the effectiveness of the recuperated heat-exchanger (epsilon(HEI)) on the performance of all cycles is carried out. The results indicate that using two stages of cooling in the intercooler could boost the gain in efficiency, because of applying evaporative inlet cooling, by up to 1.55%. Applying absorption inlet-cooling could increase the efficiency of the I cycle by up to 6.6% compared with 3.9% for applying evaporative inlet cooling. Applying absorption inlet-cooling with evaporative aftercooling could increase the optimum efficiency of the I cycle by 3.5% and its maximum power by more than 50%. Increasing TIT increases the capacity of the recuperated heat-exchanger and absorption cooling system and raises the gain in efficiency because of increasing epsilon(HEI). (C) 2003 Published by Elsevier Ltd.