Investigation of the performance of a Solar Powered Adsorption Heat Pipe

Abstract

An adsorption heat pipe was designed and built from a stainless steel tube of 32mm outer diameter, 30 mm inner diameter and 1000 mm long, the inner surface of thetube was coated by 10 mm thickness of active carbon, which was assumed to be theadsorbent, while the adsorbent was assumed to be the methanol, or acetone. Theadsorption heat pipe consist of three zones, namely adsorption/ desorption, adiabaticand evaporation/condensation zones. Electrical heater with variables capacity is used toheat up the unit generator during desorption process, water was used to cool thecondenser, while air was used to cool the generator. Two types of adsorption pair areused, namely active carbon-methanol and active carbon-acetone. The effect of heatinput to the generator on the heat pipe surface temperature and evaporator temperatureare studied. The results showed that the adsorption heat pipe can work at a relativelylow temperature namely 70-100 oC, the time required for cooling process in the rangeof 18 to 24 minutes, and activated carbon – Acetone pair gave a good behavior for theheat pipe due to the short cycle– time compared with that for activated carbon –Methanol