Experimental analysis of thermoelectric heat exchanger powered by solar energy

Abstract

Experiments were performed to test a novel solar photovoltaic (PV) powered Thermoelectric Heat Exchanger (TE-HE) to provide hot/cold water. The experiments were carried out for 3 configurations- cold reservoir charging, hot reservoir charging and single pass test. In the charging experiments, the water was recirculated in either the hot or cold reservoir to obtain heated or cooled water. In single pass test, water was circulated as a free stream to obtain cold/ hot output. The device was powered by solar PV, making it portable and able to work in remote places. The Coefficient of Performance (COP) of the device was calculated. The effect of changing the volume flow rates on the hot and cold sides of the Thermoelectric Modules (TEM) was studied. The change in COP of the cooler/ heater with the change in number of TEMs was also assessed. It was observed that the COP in the cold reservoir charging phase increased with the increase in water flow rates through the hot and cold water jackets. A maximum COP of the cold water charging mode of 1.33 was obtained for hot side flow rate of 150 L/h and cold side flow rate of 75 L/h. The performance of the thermoelectric (TE) device in cooling configuration was influenced positively by varying the size of the hot reservoir. The highest COP obtained for the heating configuration was 1.73 at the maximum water flow rates. Increasing the number of TEMs increased the performance of the heater. The minimum and maximum outlet temperatures in the single pass test were 10 °C and 49 °C respectively. The COPmax value for the cooling configuration was 0.71, and 0.92 for the heating configuration.