Simulation study of using macroporous ceramic membrane to recover waste heat and water from flue gas

Abstract

Transport membrane condenser based on macroporous ceramic membranes can better meet the requirements of power plants for the recovery of waste heat and water from flue gas. This paper proposes a condensation and permeation model for describing the process of waste heat and water recovery from flue gas by macroporous transport membrane condenser. The results obtained from model are compared with the experimental results. According to results of condensation and permeation rate, errors between the calculated and experimental data are less than 10%. According to results of outlet water and flue gas temperatures, errors between the calculated and experimental results are within 0.06%. Therefore, accuracy of the model is verified. Based on the model, effects of the parameters including flue gas temperature and flow velocity, cooling water temperature and flow velocity, flue gas relative humidity, membrane porosity, and local atmospheric pressure are studied in terms of water and heat recovery performances. The research results show that increasing the flow rate of flue gas and cooling water, increasing the relative humidity of flue gas, increasing the local atmospheric pressure, reducing the temperature of flue gas and cooling water can increase the condensation rate of water vapor, thereby enhancing the recovery performance of the ceramic membrane. The increase of the porosity of the ceramic membrane can increase the penetration rate of the condensate, and more condensate can be recycled into the ceramic membrane, so that the overall recovery effect is better.