Direct contact membrane distillation : a sensitivity analysis and an outlook on membrane effective thermal conductivity

A rigorous and high-fidelity two-dimensional numerical model for a direct contact membrane distillation (DCMD) module has been developed. The developed model incorporates all the key physics governing the transport phenomena taking place within the membrane distillation (MD) module. The spatial variation of the physical properties of the fluids flowing in the channels and the membrane with temperature has been captured. The model has been used to investigate the sensitivity of the key performance indicators or KPIs (i.e. the transmembrane flux, the thermal efficiency and the temperature polarisation coefficient) to ten key operational conditions and membrane characteristics. The models used to estimate the effective thermal conductivity of the membranes have been discussed and it was shown that more appropriate models are required to accurately estimate the latter parameter and, to this end, a new model has been proposed.