Theoretical Analysis of Working Fluid Inside Solar Thermal Trackers

To guide the aperture area of solar receptor in the direction of the sun, there are basically two types of solar tracking systems. These are the active solar tracking and the passive solar thermal tracking systems. The passive solar thermal tracking systems can comfortably be used to track solar photovoltaic (PV) and solar thermal collectors if they are properly designed and developed. The main components of such a system are two partially shaded working fluid tanks and a cylinder-piston assembly. The study’s findings indicate that if ammonia is to be heated from 20 to 60 °C, its initial quality should be adjusted to be between 0.00132 and 0.32 to ensure smooth piston displacement. Ammonia subcools before reaching 60 °C if it began heating with quality lower than 0.00132. The result causes a sudden huge rise in pressure that will not give smooth piston displacement. On the other hand, if the quality was higher than 0.32 before the start of heating, ammonia gets superheated earlier, and after that the pressure raise will be insignificant to get enough piston displacement. As compared to previously reported research works on solar thermal tracker, this research work has clearly revealed that there are two key issues that require special consideration when designing thermal-based tracking systems. The first condition is the temperature interval in which the fluid is exposed to operate. The other condition is the two state of the fluid at the lower and upper temperature limits.