OPTIMIZING COMBINED MEMBRANE DEHUMIDIFICATION WITH HEAT EXCHANGERS USING CFD FOR HIGH EFFICIENCY HVAC SYSTEMS
thesisposted on 14.12.2020, 23:01 by Ajay Sekar Chandrasekaran
7ABSTRACTAs the energy consumption for thermal comfort and space cooling around the world continues to grow due to a steadily increasing demand and climate change; the use of vapor compression technology, has increased significantly. In this technology, condensation is used to condense out the water vapor from air by maintaining the coils at a cooler temperature than required to meet the sensible load. This results in a high energy consumption for dehumidification and lowers the overall efficiency of the system. They also pose environmental threats due to its significant CO2 emissions.
The aim of this research is to address the above problems by using a novel membrane configuration called as a membrane heat exchanger that has integrated cooling coils and simultaneously cools and dehumidifies the air stream with the help of a vacuum pump and a vapor selective membrane.
In this work, the CFD modeling and design of a membrane heat exchanger is presented. The model is developed for a base case to study the heat and mass transfer performance of the system. The model after validation with existing studies is developed further to obtain several contour plots to understand the effects of concentration polarization, membrane permeance, Reynolds number, pressure drop and other design parameters on the performance of the system.