Thermal and economic analyses of solar desalination system with evacuated tube collectors

摘要

Conventional seawater desalination technology could solve the problem of fresh water shortage, but consumes a large amount of fossil fuel and causes the environmental problems such as global warming and acid rain. On account of this, solar desalination is one of the promising methods. The thermal and economic performance on solar desalination system with evacuated tube collectors and low temperature multi-effect distillation is researched in this paper. Mathematical and economic models are established based on mass and energy conservation, which conclude evacuated tube collector model, heat storage tank model, flash tank model, multi-effect distillation model and electrical heating and cooling model. Taking actual operation into account, the influence of the heating steam temperature of the first effect and the effect number of multi-effect distillation system on system performance is analyzed. The cost constitution of solar desalination system with evacuated tube collectors is shown, and the proportion of the cost of evacuated tube collector is the largest. The water cost is given out to appreciate the economic performance of the solar desalination system. The conclusions are helpful to the design and operation of solar desalination plant.