Study On Efficient Working Fluids And Comprehensive Utilization Methods Of Tubular Solar Collector

Tubular solar collector is the most commonly used solar collector,because of the low cost of production and the easy-control of heat collecting condition,but it also has the problem of low heat collecting efficiency and low solar utilization ratio of unit area.In recent years,more and more scholars are devoted to study the application of nanofluids in the field of solar-thermal conversation,and nanofluids have shown competitive performance.However,the poor dispersion stability and complicated preparation process restrict the wild use of nanofluids.Therefore,it is of great significance to improve the performance of working fluids and develop new comprehensive utilization methods of solar energy,for the scale application of solar thermal utilization.Inspired by the Chinese ink which is heavy black and has stable properties,this work proposes the application of Chinese ink as a working fluid in solar photo-thermal conversion.Compared with reported Cu,CuO nanofluids,Chinese ink has shown more satisfied stability of dispersion and higher efficiency of photo-thermal conversion.The main components of the Chinese ink which contain carbon black and bone glue were studied.It was found that,the ink particle has a colloid core-shell-like structure,where the carbon black was wrapped by a shell of bone glue.In this structure,the carbon black core is determined for the conversion of solar irradiation into thermal energy,and the shell of bone glue plays a significant role on the prevention of the ink particles from aggregation and deposition.Based on the transformation mechanism of Chinese ink,the new kind of working fluid named bionic structure mimicking frog eggs(BSMFE)was prepared,and its excellent performance has been proved by experiments.On this basis,this paper puts forward a new method named photo-thermal agriculture which combine solar-thermal collection with the planting of green plants,it could help to improve the economic output value per unit area.Aiming at this method,various types of industrialization devices were designed.Based on the photo-thermal agriculture,a unit combined rotor dynamic collector was put forward.The experiments show that the efficiency of the photo-thermal conversion is greatly improved by the rotors,and the low flow resistance structure is better than the two blade structure,the black rotor is better than the transparent rotor,the flow rate has little effect on the process of photo-thermal conversion.