A New Model and Solution Method for Anti-Freezing and Temperature Drop Analysis of Solar Collector System

Abstract

The robust and accurate evaluation of the temperature distribution of the solar collector system during the cooling process is instrumental for a reasonable and effective system anti-freezing. Thus, it is necessary to establish a proper and comprehensive model of the solar collector system. This paper presents an unsteady multi-node, thermal and hydraulic coupling model of the solar collector system. The model was established based on the analysis of the flow and heat transfer processes of the fluid in the collector system loop and following the finite difference method. The coupling model was solved by adopting an iterative method, and the model accuracy was verified by experiments. A comparative analysis was conducted, and the results highlighted that it is faster and more accurate to calculate the coupling model of a solar collector system using a methodology based on the Ferrari solution method of rooting equation and parameter settings. In addition, the cooling process of the centralized solar collector system was analyzed and evaluated. It was concluded that the non-uniform flow rate distribution of the collector system had a significant effect on the temperature distribution. Nevertheless, as the cooling process progressed, the solar collector temperature distribution gradually became uniform.

Keywords: Solar collector system, Thermal-hydraulic coupling model, Decoupling solution method, Cooling process, temperature distribution