Design study of the coupling of an air gap membrane distillation unit to an air conditioner

Ahmadou Tidiane Diaby (1, 2) , Paul Byrne (1) , Patrick Loulergue (3) , Béatrice Balannec (3) , Anthony Szymczyk (3) , Thierry Maré (1) , Ousmane Sow (2)

1 LGCGM - Laboratoire de Génie Civil et Génie Mécanique
2 ESP - École Supérieure Polytechnique de Dakar
3 ISCR - Institut des Sciences Chimiques de Rennes

This work presents the design of a membrane distillation (MD) unit coupled to a refrigeration device. The operation of an MD pilot plant is first tested then modelled using EES software. The range of hot water feed temperature provided by the condenser of the refrigeration device may vary from 25 to 65 °C as needed by the MD unit. The results of the experimental study enable to validate a 1D theoretical model with a maximum deviation of ± 6%. This model is coupled to a heat pump model to simulate the operation of a coupled machine. The system performance is studied following two scenarios. In Scenario 1 (continuous mode), the system is connected to a seawater network. In Scenario 2 (batch mode), the seawater reservoir is filled up manually every day. The simulation study shows that the increase of the feed water temperature enhances significantly the produced permeate flux but decreases the performance of the heat pump. This system exhibits high exergy efficiency and GOR for a high feed water temperature. Exergy efficiency and gained output ratio (GOR) decrease as the water flow increases and the hot water temperature decreases. Conversely, the coefficient of performance (COP) of the refrigerator increases.

Mots clés: air conditioner; coupling; air gap membrane distillation

Domaines: Thermique [physics.class-ph]

Ahmadou Tidiane Diaby, Paul Byrne, Patrick Loulergue, Béatrice Balannec, Anthony Szymczyk, et al.. Design study of the coupling of an air gap membrane distillation unit to an air conditioner. Desalination, 2017, 420, pp.308 - 317. ⟨10.1016/j.desal.2017.08.001⟩. ⟨hal-01579519⟩