Thermal behaviour of water inside an absorber tube in a solar parabolic trough collector (PTC) systems

This study is on investigating the thermal behavior of water being heated inside a horizontal tube used as a sun radiation absorber in a parabolic trough collector systems. It was assumed that the parabolic trough collector has the maximum concentration ratio and the absorber’s outside diameter is 50 mm. the surface temperature of the absorber is considered about 350 degrees Celsius.The thermal map and velocity filed of a heated water inside an absorber tube with the maximum concentration ratio has been investigated by using COMSOL Multiphysics software. Results indicated that till 2000 s, the water inside the absorber tube gets warmer and warmer gradually and after 2000 s, the thermal map of the system stays the same. The heating process of water inside the absorber tube caused a circular water movement inside the tube which is due to buoyancy flow and originates from density that varies with a temperature change. It has also been revealed that by the increase of water temperature inside the absorber tube, the circular movement of water accelerates.

کلیدواژه ها:

Thermal behaviour ، Absorber Tube ، Velocity field ، Parabolic trough collector