As the core component for photothermal conversion and utilization in energy storage power generation systems

solar collectors determine the efficiency of solar energy utilization through their solar energy capture and energy conversion performance. This paper takes the concentric tube-in-tube phase change heat storage spiral finned trough collector as the research object. By adopting the response surface experimental design method

the interaction effect between the fin height and pitch are taken is considered

and the average heat flux density is used as the evaluation index to optimize the fin structure of the collector

and to investigate the influence of mass flow rate and solar irradiance on the entire heat collection system. The research results show that the optimal parameter combination of fin height and pitch is 4.22 and 148.85 mm

with an average heat flux density of 1 343.5 W/m2. A low mass flow rate can improve the heat collection efficiency of the collector

but the heat release process is seriously delayed. Under a high mass flow rate

the phase change material melts insufficiently

leading to a decline in the thermal performance of the system. For different mass flow rates

the maximum difference in the percentage of heat storage time and solidification time is 22.22% and 15.63% respectively

and the maximum difference in heat collection efficiency is 25.53%. The response surface experimental design method can obtain the optimal parameter combination of fin height and pitch

which provides a reference for the structural design of phase change heat storage spiral finned trough collectors. In practical applications

according to the real-time changes of solar irradiance and the heat storage demand of the system

the mass flow rate of the working medium should be reasonably adjusted to maximize the heat collection efficiency and achieve the coordinated matching of the heat storage and heat release processes.