Small Heat Pump Low Temperature Experimental Study, Multi-effect Distillation Desalination Device

Desalination of seawater has been developed for several centuries, and shortage of fresh water in some region has been solved by desalination. Desalted water has not been all-pervading for the high cost, so cost reduction and high efficiency energy saving have been the emphases of desalination research. At the same time, there is a great demand for such portable equipment. Two-effect and nine-effect desalination equipments have been designed and constructed completely, according to the patent of author's energy sources graduate school. In this new system, the evaporator of heat pump is put in the end effect of LT-MED system, which is used to recycle the energy of vapor outside and condense vapor to water. The energy absorbed from vapor is enhanced by pump compressor, then translated into the condenser and used again. So this new system combines the advantages of both LT-MED which can produce large amount of water in many effects and VC which can use the energy of vapor in the end effect reduplicative. With the advantage this new system can produce water effectively.The feasibility of the new system has been testified in the experiment of two-effect desalination equipment. The average output is 5～7kg/h uniform to design data, and influenced by quantity of seawater insufflations, vacuum and state of heat pump. Then the experience can be applied to multi-effect set. The feasibility has been testified again in the data analysis of nine-effect equipment. The water average output is 40kg/h lower than design data, with the adverse conditions which are multi-liquid heat exchanger's unfulfilment, low exterior temperatures, low seawater inlet temperatures, heat pump optimization incomplete, bad airproof and so on. Nevertheless, the output of single effect is 4.4 kg/h more than congener set.