Study On The Design And Photothermal Conversion Performance Of A Disc Solar Stirling Hot Tube Cluster

Solar-dish Stirling thermal-power generation is a promising technology in the renewable energy field,where the Stirling engine is the core equipment of the solar thermal utilization system.The photothermal transformation process carried by Stirling engine directly determines the generation efficiency of the whole system.The heating tube cluster is the core component of the heat transfer capacity of Stirling in light-thermal energy exchange interface.The problem of distribution of solar energy distribution in the traditional dish Stirling engine is not uniform,the non-uniform flow of the wall surface can easily lead to "hot spot",which would reduce its reliability.From what has been discussed above,the mathematical model of tube length and tube number of heating tube of Stirling heat receiver is constructed in this paper,the tube length and tube value of heating tube for the Stirling heat receiver of 1kW effective power are solved numerically,through the characteristic analysis of the photothermal transmission path of disk solar Stirling system to design a kind of involute heating tube cluster which can meet the requirement of pipe wall energy flux.A three-dimensional model of 1 kw involute heating tube cluster was established by using the parametric modeling method of Matlab,Pro/E and then The optical properties and heat transfer capacity of the heating tube cluster are verified.The research and analysis by Optisworks and Fluent software simulation platform were carried out.The specific research process is mainly:First of all,on the basis of the characteristics of heat transfer of heat pipe and the heat transfer process of the heat pipe and analyze in this paper,the theoretical model of the running parameters of the rated Stirling engine is constructed,the mathematical model of tube length and tube number of heat absorber for the effective power of Stirling engine is obtained.The heat pipe length and tube number of different power Stirling engines are calculated,the correctness of the model is verified by comparing with the actual value.The tube length and number of tube needed for the heat pipe of Stirling heat receiver with effective power of 1kW are solved numerically.Research results show that:The heat tube length and number of tube number of the four cylinder Stirling engine with different effective power are solved by solving three different effective power of 38 kW,90kW and 127 kW,After comparing its actual value,it is found that the constructed mathematical model can effectively control with the error range within plus or minus 7%.The heating tube of the four-cylinder Stirling heat machine with effective power of 1kW is 31 cm and the tube number is 28.Next,According to the minimum principle of heat loss,the cavity structure and relative dimensions of the four cylinder Stirling heat absorber with effective power of 1kW are derived.Through Matlab programming software and Pro/E joint parameterization modeling method,a three-dimensional model of tube cluster type heat absorber is established,The heating tube cluster of this structure can effectively increase the direct radiation area of the heat pipe in the same space.The Optisworks optical analysis software is used to compare the optical properties of the involute tube cluster and the direct tube cluster.The research shows that :The involute heating tube cluster has more uniform surface energy flow distribution than the direct tube cluster,The difference of the heating tube cluster of the four-cylinder unit is small,the maximum flow value of each heating tube in the same cylinder unit is basically the same.Finally:Through Fluent6.3CFD software,the distribution of energy flow density of tube cluster wall surface can be obtained by using the third chapter of optical simulation,research of the flow and heat transfer performance of photothermal coupling.The research shows that :The temperature difference of the heating tube of the involute tube cluster under the condition of the same working condition is smaller,as the inlet velocity increases,the temperature distribution of the heating tube wall decreases,When heating tube inlet velocity of1 m/s speed up to 2 m/s,the temperature drop to 242 k,from 2 m/s speed up to 3 m/s,when the temperature drops 104 k,3 m/s to 4 m/s,the temperature decline of 54 k,4 m/s to 5 m/s,the temperature decreased by 31 k.