The term "solar collector" commonly refers to a device for solar hot water heating, but may refer to large power generating installations such as solar parabolic troughs and solar towers or non- water heating devices such as solar cookers or solar air heaters. Solar thermal collectors are either non-concentrating or concentrating.
Such curves describing the variation of the thermal efficiency of solar collectors are presented in the data sheets of manufacturers or of independent testing laboratories. The uncorrected formula leads to high calculation errors especially for collectors with evacuated tubes and with thermal tubes for high temperature differences.
By increasing the flat plate solar collector outlet fluid temperature, the temperature change in the exchange of thermal energy with the sun reduces. As a consequence, the fluid irreversibility rate enhances by 21.73% for inlet fluid temperature varying from 20 to 65 °C (Fig. 14).
Solar thermal collectors have been widely studied, and various new designs were reported. To improve the performance of these solar devices, it is essential to understand the heat transfer behavior of the systems.
Provided by the Springer Nature SharedIt content-sharing initiative The chapter presents the fundamentals for performance evaluation of different types of solar thermal collectors (STC): flat thermal collectors (FTC), evacuated thermal collectors (ETC) and concentrated thermal collectors (CTC). All the STC can be integrated in the...
The average amount of heat energy produced by a flat plate solar collector during a day has been calculated by formula K – parameter, ̊C. ̊C; Tin – heat carrier inlet temperature into collector, To – surrounding air temperature ̊C; L – average monthly value of atmosphere lucidity.