Novel heat dissipation design incorporating heat pipes for DC combiner boxes of a PV system

In a Photovoltaic (PV) system, heat is generated by an operating diode. Because DC combiner boxes are waterproof, dustproof, air tight and made of heat-insulating material, thermal energy is easily accumulated, affecting the performance and safety of power cables and other electronic components near the diodes in the DC combiner box. This study utilizes a heat pipe as a channel for heat dissipation to conduct the heat out of a DC combiner box without destroying the air-tightness of the box. An existing DC combiner box was improved upon using this method of heat dissipation. The measured heat flow and temperature demonstrate that the proposed method is feasible. The influence of the condensation section temperature on the maximum heat transfer of the heat pipe was also investigated by experiment. The maximum heat transfer rate of the heat pipe was found to increase with the condensation section temperature of the heat pipe. When the condensation temperature was 20 °C, 30 °C and 40 °C, the maximum heat transfer rate of the heat pipe was 21.6 W, 29.6 W and 39.7 W, respectively.

► Heat emission is an important issue of DC combiner boxes for PV systems.
► We utilized a heat pipe as a channel for heat dissipation to conduct the heat.
► An existing DC combiner box was improved upon using this method.
► The maximum heat transfer rate of the design was found to increase with the condensation section temperature.