A comparison between the HAT cycle and other gas-turbine based cycles: Efficiency, specific power and water consumption

The search for improved power cycles leads to various gas-turbine based cycles with very different characteristics and complexities, ranging from the traditional recuperated gas-turbine cycle to complexes' combinations of components such as intercooled compression, compressed air aftercooling, recuperation and/or reheat. In this work the HAT cycle (humid air turbine) is compared with the simple-cycle gas-turbine, the recuperated (and the intercooled-recuperated) gas-turbine cycles, the STIG (steam injection gas-turbines) and also with the combined-cycle. The focus of comparison is also put on the needed water quality and consumption, as well as on performance and emissions. The efficiency and/or specific power production advantages of each analyzed cycle are weighted against the cycle complexity, specific emissions and water needs. The different degrees of water purity for each use are also discussed and a differentiation is made between water circulation and water consumption. The possible best-range of applicability is addressed to each cycle, taking into account the power plant size and also the gas-turbine classical operating parameters as pressure ratio, turbine inlet temperature and operation profile. (C) 1997 Elsevier Science Ltd.