Analysis of thermal performance a heat pipe for concentrated photovoltaic cooling

Heat pipes are used in this study for the concentrated photovoltaic (CPV) passive cooling. Investigations have been done in two steps: in the first step, the heat pipe's thermal performance in the horizontal position has been tested. Two sets cylindrical heat pipes with identical diameters (6 mm) but of different lengths (250 mm and 150 mm, respectively) were employed. Each set consists of three heat pipes. The results of the study showed that the heat pipe has a maximum operating point that is dependent on both the intensity of the incident light and the surrounding temperature. Moreover, this operating point could be determined. For high light intensity, a long heat pipe performs better than a short one, and vise versa. In the second step, a heat pipe passive cooled CPV system has been investigated for both long and short heat pipe systems. The performance of heat pipe cooled CPV system was compared to that of the traditional fins-cooled CPV system. Results showed that at light concen-trations of 55 X, cooling a solar cell with a heat pipe enhances its maximum output power by 6% for a long heat pipe and by 7% for a short heat pipe, respectively. While at 210 X illumination concentration, long and short heat pipes, respectively, produced gains of 16 and 12% in the cell's maximum output power.