Experimental analysis of thermal performance of solar collectors with different numbers of heat pipes versus a flow-through solar collector.

This paper presents a comparative study of the experimental analysis of two heat pipe solar collectors with different numbers of heat pipes and a flow-through collector. For this purpose, three collectors were designed, constructed and tested side-by-side under various environmental conditions. In this study the three collectors selected were: first, a collector with six heat pipes, type(I); second, a collector with twelve heat pipes, Type (II); and third, one flow-through solar collector, type (III). These collectors were simultaneously tested outdoor according to ASHRAE standard 93–1986. Tests showed that the efficiency of collector type (II) was higher than the other two. The thermal efficiency of flow-through solar collector (III) at mid-day was higher than collector type (I); however, the efficiency of collector type (I) was higher than the conventional collector type (III) in the morning and in the afternoon. There are two methods to increase the efficiency of heat pipe collectors, the first is to increase the number of heat pipes and the second is to increase the effective absorber area by proper design of the heat pipe condenser. [ABSTRACT FROM AUTHOR]