NUMERICAL SIMULATION OF LOW GRADE HEAT AND WATER RECOVERY USING NANOPOROUS TRANSPORT MEMBRANE CONDENSERS BUNDLE TUBES

摘要

Low grade waste heat and water recovery using ceramic membrane, is an emerging technology which helps to increase the efficiency of boilers and gas or coal combustors in various industrial processes and conventional power plants. The tube wall of a Transport Membrane Condenser (TMC) based heat exchanger is made of a nano-porous material with high membrane selectivity which is able to extract condensate water from the flue gas in the presence of other non-condensable gases (i.e. CO2, O2 and N2). In this work, a numerical study has been carried out to investigate the effects of transversal pitches of the TMC bundle tubes on the performance of a TMC based cross flow heat exchanger. A simplified multi-species transport model is used to investigate the heat and mass transfer characteristics of a condensing combustion flue gas in a cross-flow transport membrane tube bundle. Various transversal (0.4"-0.6") and longitudinal (0.4"-0.8") pitches were used. The numerical results revealed that the effect of transversal pitches on the outlet parameters are more pronounced.