Thermo-economic analysis of air saturator integration in conventional combined power cycles

Abstract This paper presents a detailed thermodynamic and economic analysis on a conventional combined power cycle integrated with the Maisotsenko heat exchanger. The results obtained were compared with the conventional combined cycle to see the impact of the Maisotsenko technology on the thermal efficiency, air mass flowrate required and the levelized cost of electricity. A Maisotsenko heat exchanger is placed at the inlet of the air compressor to cool down the air to reduce the power input and the air flowrate required. As a results smaller turbomachinery equipment are installed, which aids in decreasing the capital cost. In addition, another Maisotsenko heat exchanger is placed before the combustor to saturate the air streams to allow effective heat recovery from the turbine gasses at the recuperator. This will help in reducing the fuel burnt in the combustion chamber, thus reducing the operating cost. It was found that the Maisotsenko combined cycle (MCC) has a higher overall thermal efficiency than the conventional combined cycle (CC) by 6%, which reduced the levelized cost of electricity LCOE by 3.8 US$/MWh. However, due to the nature of the Maistosenko technology, 19.55 kg/s of water is required to saturate the air and provide an effective heat recovery from the exhaust gasses. Finally, a parametric analysis was conducted on the MCC and the CC to compare system behaviors when certain operating parameters change.