Heat and water recovery from flue gas: Application of micro-porous ceramic membrane tube bundles in gas-fired power plant

Abstract

Heat and water trans-membrane condenser (HWTMC) consisted of ceramic membrane tube bundles and cooling pathway is a functional apparatus to recover heat and water from flue gas in thermal power plants. In this study, the water and heat-recovery performance of 2 μm HWTMC on a gas-fired power plant was studied theoretically and experimentally. The simultaneous drop-wise/film-wise condensation heat transfer process was proposed in this study, and we investigated them by installing several temperature sensors within the HWTMC. In addition, the heat and water-recovery performance of HWTMC was evaluated respectively under different operational conditions, and the velocity loss of flue gas was also measured to verify its practicability. The experimental results showed that flue gas temperatures change significantly in the first 2/3 of the HWTMC unit, while barely change at end, especially when they are higher than 103.5°C. Compared with other operational conditions, moreover, a moderate cooling water inlet flow rate (0.3 m3/h) would result in a remarkable heat and water-recovery performance. To guarantee the efficiency of the experimental HWTMC with total membrane area of 0.145 m2, flue gas flow rate should be set under 500 m3/h. This paper is useful for membrane type waste heat and water-recovery installation design.