Experimental Testing of a Thermoelectric-Based Hydronic Cooling and Heating Device With Transient Charging of Sensible Thermal Energy Storage Water Tank

Experiments were performed to charge either cold or hot water thermal energy storage tanks using a heat exchanger equipped with multiple thermoelectric (TE) modules. The primary objective was to design a simple, but effective, modular Peltier heat pump system component to provide chilled or hot water for domestic use at the appliance level, and when arranged in multiple unit combinations, a system that can potentially satisfy small home cooling and heating requirements. Moreover, when the TEs are directly energized using solar photovoltaic (PV) panels, the system provides a renewable, pollution-free, and off-the-grid solution to supplement home energy needs. The present work focuses on the design and testing of a thermoelectric heat exchanger component that consists of two water channels machined from two aluminum plates with an array of three, five, or eight thermoelectric modules placed in between to transiently cool and/or heat the water in the thermal energy storage tank. The water passing over either the cold or hot side of the TE modules is recirculated to charge the cold or hot thermal storage tank, respectively. The temperatures in the prototype Peltier heat exchanger test component and thermal energy water storage tank were measured during both cold and hot tank charging operations. The thermal efficiencies of the TE heat pump cooling/heating system are reported. The effects of the TE power input, number of TE units, rate of fluid flow, and heat sink/source temperature are studied.