1：Experimental Design and Method Selection:

The method involves comparing two models - an analytical model based on energy balance and a numerical model developed from recorded operating data. The analytical model uses the collector energy balance to combine characteristic parameters, while the numerical model is based on the Blackbox identification method using recorded data of medium inlet and outlet temperature, and solar irradiance.

2：Sample Selection and Data Sources:

Operating data from a solar heating system composed of two flat-plate collectors connected in parallel and heat loaded with a 100 dm3 storage tank were used. The data included solar irradiance, medium inlet and outlet temperatures, and flow rate.

3：List of Experimental Equipment and Materials:

The test stand included PT1000 thermal resistant sensors for temperature measurement, a variable speed pump for medium flow, and a flow meter. The system was controlled by a PLC connected to a PC with a SCADA program for data visualization and archiving.

4：Experimental Procedures and Operational Workflow:

Experiments were conducted for different flow rates of the working medium (propylene glycol) to analyze the impact on collector static and dynamic properties. The System Identification Toolbox of the Matlab package was used for parametric model development.

5：Data Analysis Methods:

The developed models were compared to determine characteristic parameters of the solar segment. The analysis included the impact of flow rate on gain coefficients of the main and disturbance paths, and the determination of heat loss coefficient, heat removal factor, and collector efficiency factor.