Modeling and Simulation of Saturator Temperature Control in Humid Air Turbine Cycle

Humid Air Turbine (HAT) cycle is one of the most advanced gas turbine cycles in the world. It has drawn great attention due to its high efficiency and good environmental compatibility. The saturator is the key component in the HAT cycle, which utilizes liquid water to humidify compressed air to improve the system performance and make it possible to recover low temperature waste heat in the HAT cycle system. Therefore, saturator temperature control occupies very important position in HAT cycle, and it is essential to study the control logic in saturator. Saturator temperature control is a control strategy that adjusts the water flow rate to fit the designed temperature. In this paper, the HAT cycle test rig of Shanghai Jiao Tong University is taken as research object and a complete HAT cycle model using global heat and mass transfer coefficient is built to analyze the influence of saturator temperature control on both steady-state and dynamic performance of HAT cycle system. The system efficiency increases by 0.071% after considering saturator temperature control on 75% load. The dynamic response of output power changes little, while the saturator component can achieve stable faster. The research in this paper can lay the foundation for operation and control of the HAT cycle demonstration plants.