Experimental Study Of The New Solar Membrane Distillation System About Collector’s Loop

Solar membrane distillation system is a new water technology which is a combination of solar energy and membrane distillation desalination. In today’s energy shortage, scarcity of freshwater resource under the background of the times, solar membrane distillation desalination water system will become an important technical measure that can solve the lack of fresh water resource.In order to solve the lack of fresh water which is serious in China’s western region, we take a research for solar collector heating system in solar membrane distillation desalination water system. As the U-tube collector with high thermal efficiency, small heat loss, start fast, big pressure, high temperature characteristics, this article uses a U-tube collector with CPC reflectors and built the solar heating system.Solar membrane distillation desalination water system needs hot end provide hot thermal solution from 30℃to 90℃, also the temperature of low-temperature heat source needs to be remain unchanged in the running. The article takes a research for U-tube solar collector circulatory system based on this situation. By analyzing the data of the solar radiation, wind direction, wind speed and other meteorological information and import and export temperature of solar collector, tank temperature and other parameter’s changes, we find that the wind direction, wind speed and solar radiation have a greater influence on the stable operation of the system. ambient temperature, operation mode, collector connections, the type of collector, piping connections and so on are all have a certain influence on the stable operation of the system. Wind direction and wind speed primarily by changing air flow on the collector surface, thereby affecting the collector absorption of solar radiation; Changes of solar radiation directly affects the collector’s heat absorption, thereby affecting the temperature of the hot end of the system; The medium temperature’s change causes medium temperature in solar collector system changed, affecting the stability operation of the system; In different operating modes and connections, the system’s operation is different; System using different collector area, the operation changed; different kinds of collectors, the system thermal efficiency is not the same; Import and export temperature of solar collector is higher, tank can store much more heat. By analyzing the operation of the system under different operating conditions, we found that solar collector system in the forced circulation and collector running in parallel, the system has a higher thermal efficiency.The article by calculating obtains the heat of the water tanks, founding the relationship between produced water of membrane distillation system and heat transfer of collector system and receiving conversion methods between produced water and heat transfer. Obtained by computing that 2 square meters collector runs up with 18 films, system produced water 96.768kg after running 8 hours. Collectors operate in parallel up with 18 films, system produced water 166.656kg after running 8 hours. The thermal efficiency of the system has a great influence on the production of water, therefore, improving the system thermal efficiency and reducing heat loss is the main way to increase water yield. We can see from the above that the system has a great significance for solving the problem of drinking water in water-poor areas.