Experimental and numerical investigation on a photovoltaic heat pump with two condensers: A micro-channel heat pipe/thermoelectric generator condenser and a submerged coil condenser

Abstract

Thermoelectric generators are proposed to be applied to the heat pumps to further improve the electrical output of the system. Some mathematical analyses have been carried out, but the related experimental exploration is lacked. In this paper, a photovoltaic heat pump with two condensers: a micro-channel heat pipe/thermoelectric generator (MCHP/TEG) condenser and a submerged coil condenser, was built and tested under different weather conditions. Results show that the water temperature rises with running time, leading to the decrease in heat capacity and coefficient of performance (COPth: only consider the heat; COPPVT: consider both electricity and heat). On 29th May, the average photovoltaic output, condensing heat, COPth, and COPPVT are 358 W, 3373 W, 3.96, and 5.08, which are improved to 485 W, 3705 W, 4.32, and 5.80 by the better irradiation condition on 30th May, but the average electrical efficiency is decreased from 16.63% to 15.65%. The TEG output is also higher under better irradiance. However, due to the poor performance of the commercial TEG, the TEG output in the experiment is low. With better parameters or a larger photovoltaic evaporating area, the TEG output and system performance could be enhanced. This article is also a supplement and improvement to several previously published articles in terms of experiments and verification.