Comparative performance evaluation of conventional multi-effect evaporation desalination processes

The three different configurations of the multi-effect evaporation system: the parallel/cross, forward and backward feed configurations were studied. On the basis of material and energy balances, mathematical models are developed for all the configurations. These models are used to study the effect of all the parameters on total capacity, gain output ratio, specific heat transfer area, specific heat consumption and temperature difference between effects under different operating and design conditions. Results indicate that for the three feed schemes, steam temperature and temperature difference per effect have the major impact on the specific heat transfer area of the effects. Results also showed that the parallel/cross feed scheme has better performance characteristics than the other two feed configurations. Parallel/cross feed configuration has higher gain output ratio and lower specific heat consumption than the other two arrangements.