Experimental and numerical study on a novel fanless air-to-air solar thermoelectric refrigerator equipped with boosted heat exchanger

Abstract

Peltier cooling systems are generally small, portable and simple in operating principle compared to conventional vapor compression cooling systems. For these reasons, Peltier cooling systems are proposed widely to use in the field. In studies on Peltier coolers presented in the literature, equipment such as pumps and fans is used and this causes noise and vibration. In order to resolve these problems and negative effects, a cooling system was designed and manufactured using completely motionless elements. Additionally, the electricity energy need of this thermoelectric cooling chamber is fully met by solar energy. This study was investigated both experimentally and numerically by using computational fluid dynamics (CFD) methods. By designing a special heat exchanger in the produced air-to-air cooler system, it has been proven that, the Peltier system can work effectively without the need for any elements such as fans. Then the effects of the voltage values applied to the system and the number of Peltier modules have been investigated. The experiments were carried out at 4 different voltage values (1.5, 2.0, 2.5 and 3.0 V) and in 3 different Peltier numbers (1, 3 and 5) in consecutive connections. According to the obtained results, the most suitable situation for reducing the temperature of the cooling chamber were obtained as the voltage was at a maximum of 3 V and the Peltier number was maximum (5 Peltiers mode), where the internal temperature of the cooling chamber decreased to 11.28 °C. It was observed that, the coefficient of performance (COP) values decreased over time in all experiments. Considering the data taken at the beginning of the experiments, the maximum COP value was obtained as 0.04 when 1 Peltier and 1.5 V voltage were applied.