Novel EFHAT System With Enhancement of Humidification by Recovery of GT Exhaust Latent Heat

In this paper, we have proposed a new type of gas turbine cycle based on innovative combination of a newly designed HAT cycle with an externally fired boiler (EFHAT). In this manner, “dirty” fuels such as coal, biomass and etc. can be more efficiently used than before, and the water can be recovered. It is different from the conventional HAT cycle. In particular, the temperature of clean humid air discharging to atmosphere is not limited by the dew point, and the latent heat of steam can be utilized to generate hot water entering the humidifier. Therefore, the humidification ability is significantly enhanced, which is beneficial to improvement on system efficiency. As a result, with a gas turbine of 1073 K TIT, the net efficiency of the new system may reach as high as 43.0%. Furthermore, we have identified that air saturation can make a good temperature match in system, which results in effective utilization of both quality and quantity of energy at low and/or middle temperature range. With the principle of cascade utilization of energy and the methodology of system integration, we have opened up a new orientation for the clean coal power generation system.Copyright © 2002 by ASME