Conference Year
2021
Keywords
solar-driven refrigeration, latent heat energy storage, cold thermal energy storage, phase change materials, domestic refrigeration
Abstract
In remote rural areas without access to the electrical grid, the use of a stand-alone photovoltaic (PV) installation to drive a domestic refrigerator can be a viable option for adequate food preservation. In this application, energy storage, probably in electric batteries, is required to guarantee refrigeration conditions during periods without solar energy availability. However, electric batteries are still costly, have limited lifespan and use materials with restricted availability. Latent heat thermal energy storage (LHTES) can be an alternative to electric batteries with reduced cost and lower environmental impact. The current study presents general design guidelines for a system with a household refrigerator driven by PV power and with LHTES units. The LHTES units consist of finned panels filled with phase change material (PCM) that are placed on the vertical walls of the compartments, and are passively discharged by free convection. A thermodynamic model is used to size the system components and assess the technical viability of the proposed configuration. Special attention is paid to the heat transfer considerations involved in the design of the LHTES units to guarantee the required charge and discharge powers. The analysis is applied to a 400 L sample commercial refrigerator operating in Medellín, Colombia. It is concluded that the refrigerator necessitates moderate modifications to achieve the technical viability of the proposed configuration.