| With the introduction of the " double reduction policy ",the low-cost and highefficiency utilization of renewable energy has received widespread attention in response to environmental degradation,shortage of fossil energy and other issues related to the prospects of human survival and development.And solar energy,as a clean,low-cost renewable energy source,has high application potential.At the same time,the shortage of water resources has always been a difficult problem for China and the world to solve.The development of solar water desalination technology is one of the effective means to solve the water shortage.This paper adopts concentrated hot localization interfacial evaporation desalination system for research main line.Then,the simulation and experimental method is used for carrying out the design and performance analysis of concentrator,optimization of concentrator uniformity,project design of photochemical interfacial deslination system.The conclusion will provide theoretical support for the development of high point-focused concentrator and the application of the concentrating heat transfer system.The main research contents of this paper are:1.Design and performance analysis of Annular Fresnel ReflectorAccording to the traditional linear Fresnel concentrator and Fresnel lens,the structural principle analysis and design formula derivation of the Annular Fresnel Reflector are carried out in this paper.And the corresponding three-dimensional model and ray tracing model are built.The performance analysis of the variable structure parameters of the reflector is carried out.Then,it is concluded that the top layer of the reflector has large defects in light gathering.In addition,the possible equipment deviation and tracking deviation of the reflector are analyzed.When the tracking deviation is less than 1°,the performance of the concentrator is acceptable,and the light reception rate is not less than 96.79%.2.Design,simulation and experiment performance analysis of Annular Fresnel solar concentratorAccording to the defects of the top mirror of the reflector,this paper adds a Fresnel lens to form the Annular Fresnel solar concentrator in the central area of the reflector.According to the design principle of the Fresnel lens,this paper obtains the structural parameter design process.In addition,according to the ray tracing model established above,the simulation performance analysis and error analysis of the annular Fresnel solar concentrator are carried out.The influence of the lens addition is obtained.The concentrating ratio,average irradiation,maximum irradiation and solar power of receiver increased by 8.83%,9.49%,1 0.70%and 9.49%respectively.According to the above,the experimental bench was built,and the coil radiator was used as the receiving surface for experimental analysis.Then,the experimental performance changes with the lens addition were compared in terms of the surface temperature of the receiving surface.The temperature difference is close to 500℃ with the addition of lens,and about 400℃ without lens.Finally,the Annular Fresnel solar concentrator was analyzed.The reasons for the inhomogeneity of the energy field of the device and the optimization ideas are discussed.The maximum temperature difference on the surface of the radiator is 130℃,and the minimum temperature difference is about 93℃,which is significantly different from that of the coil radiator at 500℃3.Numerical simulation and experimental analysis of manifold microchannel heat sinkBased on the design of the concentrator,this paper optimizes the energy uniformity of the concentrator through the heat sink.On the basis of previous research on heat sink s,this paper adjusts and optimizes the structure of the heat sink to adapt to the Annular Fresnel solar concentrator.Then this paper builds one 3D model using Solidworks,and uses finite element software to divide the mesh and adjust the governing equations.After establishing and solving the model,the performance of the heat sinks under variable working conditions is analyzed,and the model is verified by experiments.Finally,a corresponding experimental bench was built to analyze the experimental performance under the concentrated condition,and the performance of the coil radiator was compared.4.Concentrated solar desalination system based on interfacial evaporation technologyIn this paper,a new type of desalination distiller is designed based on the concentrating characteristics and structural characteristics of the Annular Fresnel solar concentrator.And the evaporator material suitable for concentrating conditions is selected according to the technical principle of interfacial evaporation.At the same time,concentrated thermal local interfacial evaporation desalination system suitable for Annular Fresnel solar concentrator is developed by modifying the distiller.The mathematical model of the interfacial evaporation system was built.The manifold microchannel was coupled with the interfacial evaporation system.The design idea of the system scheme was proposed.Finally,a comparative experiment was carried out on the desalination performance of the distiller before and after the transformation.The maximum GOR of interfacial evaporation is 27.1%,and the maximum GOR of undersurface heating is 15.75%.The performance advantage of the interfacial evaporation technology compared with the traditional bottom heating technology under the condensing condition was obtained.Then,this paper conducts efficiency comparative analysis of the solar desalination system based on nearly references.In summary,the structure parameters of concentrator and the distribution characteristics of energy field are optimized in this paper.Combined with the characteristics of interfacial evaporation,a design scheme of interfacial evaporation desalination system based on Annular Fresnel concentrator and heat field distribution technology is proposed,which provides a feasible way for the engineering application of solar seawater desalination. |
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