Experimental Study Of Stacked Tray Solar Distillation Strengthened By Vacuum-pump Offering Additional Power

With scarcity of fresh water resources, China is caught into face predicaments of water source shortage and poor water quality. Especially the security issues of brackish water as a drinking water source in the western rural area must be resolved as soon as possible. Therefore, the state will make more efforts to guarantee drinking water safety and security in rural areas. In western region of China, characteristic of scarce rainfall, the strong evaporation, salinity water but rich solar energy resources are very prominent, where technology is relatively backward. According to these situations, solar stacked disc distillation strengthened by additional power is studied. The experiment is divided into two stages. The base experiment is in steady state conditions with the electric heater as a heating source, in which the effect of external vacuum suction enhanced single-stage and two-stage distillation desalination are compared. The relationship between distiller water production and operating temperature, salt concentration, suction pressure and other factors are obtained from the experiment. The experimental production water quality and efficiency are compared in experiment, which provide the parameters for heat transfer performance improvements and integration equipment promotions. the solar power to strengthen integrated Diego disc distillation desalination pilot test was based on the form of in the previous stage, the distiller was modified and integrated: the reactor series was improved to 5, and the multi-level distiller's performance and capacity of water were tested, and a simple calculation of the economic costs of practical application was conducted according to the literature, and the feasibility of practical application of distiller was demonstrated.The results showed that: with the operating temperature and suction pressure increasing, the fresh water production would raise either, as well as energy consumption. However, due to many factors such as production process, thermal insulation properties, distillation, heat exchange performance limitations, the pressure did not need so high. For the reactor, the appropriate operating temperature is at 60℃and suction pressure is 0.04Mpa, under which conditions, salt concentration of 10g/L desalts, whose thermodynamic efficiency is up to 48%. According to simple economic accounting, water cost of the solar disc stacked desalination integrated system worth 15.5 yuan. Compared to the current market of pure water costs, desalination costs have advantages. However, as time is limited and the reactor heat transfer system is not perfect, experiment in actual weather conditions has not been completed, so the stills of the actual water production efficiency is unknown. It still remains to further verify by other tests.The results indicate that the solar stacked disc distillation system strengthened by additional power has advantages to promote in majority dry areas in western China, with characteristics of simple structure, stable performance, cheap solar energy and environmentally safe. The technology has great potential, which is also needed further research on reactor heat transfer performance of solar collectors to improve the energy efficiency.