The Comparative Research On Economics Of Solar Desalination Systems

With the rapid development of industry, both energy and fresh water consume more and more rapidly, and most of the world has appeared varieties of fresh water shortage problem. To solve this problem, people have been devoted to transforming seawater to fresh water, namely seawater desalination, to meet the needs of industrial production and human life. Solar desalination has attracted more and more attention, because it consumes less traditional energy and produces less environmental pollution compared with the traditional method of seawater desalination.This paper mainly carries on a comparative study on the performance of solar desalination system coupled with the solar pond and the system coupled with evacuated tube collectors. On the basis of existing physical model, mathematical model and economic calculation model, we obtain the following conclusions by the comparative study on both performances.With the same fresh water production, the same number of the effects of LT-MED and the same temperature of the heating steam of the first effect, fresh water cost of the system coupled with solar pond is lower than the system coupled with evacuated tube collectors.And the difference of fresh water cost between the two systems reduces when the number of the effects of LT-MED or the fresh water production increases.Both fresh water costs of the two systems reduce when the number of the effects of LT-MED or the fresh water production increases. The investment cost of the system coupled with solar pond is lower than the system coupled with evacuated tube collectors. But the electric auxiliary cost and the cost of land of the system coupled with solar pond is higher than the system coupled with evacuated tube collectors.When the price of land is higher than1725￥/m2, the system (which has8effects and fresh water production of which is300t/d) coupled with solar pond will be higher than the system coupled with evacuated tube collectors.In addition, this paper also carries on a comparative study on the influences of some parameters on the investment costs, the running costs and the electric auxiliary costs of the two systems. These parameters include fresh water production, the number of the effects of LT-MED and the temperature of the heating steam.