Performance Analysis of a Humid Air Turbine Cycle With an Aero-Derivative Gas Turbine

Abstract

Nowadays, the issues of the energy and environment become more and more serious with the demand of energy increasing drastically. The advanced gas turbine cycles provide the opportunities to solve these issues. Humid air turbine (HAT) cycle, which is one of the most promising cycles with high efficiency, low emissions and low unit investment costs, is a prominent representation of the advanced gas turbine cycles. In this paper, an aero-derivative three-shaft gas turbine was converted to the HAT cycle. The aero-derivative is one of the most efficient simple cycles, whose system efficiency can reach 40%. And it is an effective solution to transform the advanced technology from the aeronautical filed to the industrial application. In order to investigate the performance of the HAT cycle, the saturator model was established based on the saturation curve and the saturator working line. Additionally, it was validated that the saturator model was consistent with the steady state experimental results very well. The maximum error of the outlet air temperature is less than 0.8% and the maximum error of the outlet air humidity is less than 1.9%. Three different HAT cycle systems were designed and simulated on the MATLAB platform. The thermodynamic performance of the three HAT systems on the design point shows that case 2 is the better one, which means that the aftercooler does not have obvious benefits for system performance and NOx emissions. Then, the effects of the ambient temperature on the case 2 and simple cycle were investigated. The results show that the HAT cycle has the more favorable off-design performance than the simple cycle when the ambient temperature is changed.