Experimental analysis of the air humidification process for humid air turbine cycle using a two-phase measurement system

摘要

The humid air turbine (HAT) cycle utilizes the low-temperature heat from the gas turbine exhaust to humidify the air, thereby increasing the specific output work. The air humidification process has a significant impact on gas turbine efficiency. So far, there is still a lack of reliable experimental data from gas-liquid two-phase flow, which limits the in-depth study of the air humidification process. In this work, the new multi-point gas-liquid two-phase temperature and relative humidity measurement system suitable for countercurrent pressurized humidifier is re-designed, the temperature and relative humidity distributions of humid air and the water temperature distribution are obtained along the height of humidifier. The effects of the water-air ratio and inlet water temperature on the humidification process are thoroughly investigated. The water-air ratio has little effect on the outlet air temperature, and it has a significant effect on the air and water temperature in the packing segment, and the relative humidity and absolute humidity increase as the water-air ratio increases. The outlet air temperature and water temperature increase as the inlet water temperature improves. The sooner the air reaches saturation and the absolute humidity increases more significantly at higher inlet water temperature. Vapor condensation occurs at the interface during the humidification process. Besides, the outlet water temperature can be cooled to be lower than the wet bulb temperature of the inlet air, but always higher than the dew point temperature of the inlet air. The measurement data provide an experimental basis for studying the heat and mass transfer inside the humidifier.