The solar powered refrigerator and heat pump for urban street vendors

Mechanical Engineering Department, Cape Peninsula University of Technology, PO Box 1906, Bellville, 7535 Cape Town, South Africa

Abstract

This article proposes an integrated solar PV refrigerator and heat pump (ISPVRHP) for Sub-Saharan African food vendors; the warm chamber would keep prepared food warm until the food is sold, while the cold chamber would minimise food spoilage. The ISPVRHP proposed in this article can cool water or other beverages and be capable of utilising the heat rejected to the atmosphere by the condenser for warming food. The ISPVRHP was modelled using ANSYS software, and the results were validated experimentally. The results show that both systems work well at peak hours, especially under more intense sun rays. The study found that the variation of incident solar radiation and ambient temperature has significant effects on the performance of the ISPVRHP; the wind speed, however, has only a minor impact on the total heat load of the system. In addition, the systems (cooling and heating) reached the desired temperatures and maintained them for long periods. The capacity of the refrigeration system can be increased by increasing the component sizes, including the PV system size. The ISPVRHP performance dropped substantially when the doors remained open for extended periods due to loss of energy through mass transfer.