Steady State Analysis of Multiple Effect Evaporation (MEE) Desalination Process

Life without water is not possible. Like other natural resources, the global resources of fresh water are unevenly distributed. The world population is increasing at very rapid rate while the natural water resources remain constant. This gap is expected to widen dramatically in the near future. Our country like most countries in the east suffer from water stressed condition. Desalination is only the logical or available solution. In MED units, the feed seawater sprayed individually in each effect is heated to form pure vapors, which condense to form product water. Irrespective of the continuous development of the desalination industry the thermal desalination is still expensive. The study presented in this thesis is motivated by, to study the impact of various cost controlling parameters on the performance of MEE desalination process. KANUPP has two desalination plants (RO and NDDP). The NDDP has parallel feed cross flow multiple effect evaporation (MEE-PC) configurations. The study presented in this thesis describes a simplified steady state mathematical model to analyze the MED systems. The results obtained by the model are compared with the NDDP data. The developed model is used to investigate the effect of the parameters controlling the product water cost. These parameters includes thermal performance ratio, cooling water flow rate and heat transfer area. It can also be used to study the effect of variation in the operating conditions of the plant on the plant performance. The effect of the process variables on the performance of MED is carried out. This includes the effect of number of effects, intake seawater salinity and heating stream temperature, vacuum condition in term of vapor temperature of last effect. (author)