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ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
THERMO-ECONOMIC ANALYSIS OF A CONVENTIONAL REFRIGERATOR HOUSEHOLD USING PCM
Submission Author:
David Silva Ferraz , MG
Co-Authors:
David Silva Ferraz, Sara Isabel de Melo Resende, Cleison Henrique de Paula, Ralney Faria, Raphael Nunes Nunes de Oliveira
Presenter: Sara Isabel de Melo Resende
doi://10.26678/ABCM.ENCIT2022.CIT22-0364
Abstract
In Brazil, household refrigerators correspond to 30% of the average consumption of domestic electrical energy. Improving the efficiency of these equipment promotes a reduction of domestic costs with electric energy while simultaneously reducing the demand to join electric services. In 2021, Brazil went through a water crisis with a reduction in the volume of water in hydroelectric dams, implying greater participation of thermoelectric plants to avoid blackout situations. To reduce the residential demand for electricity and increase the energy efficiency of household refrigerators, this work proposes the numerical simulation of the behavior of a domestic refrigerator integrated with a PCM (Phase Change Material) positioned next to the condenser for storing energy in the form of latent heat to extend the time the compressor remains off and reduce the number of components starts. The PCM absorbs heat from the condenser during the time the compressor is running and changes from the solid phase to the liquid phase by absorbing latent heat. The thermal inertia provided by the phase change of the PCM in the condenser allows the heat exchange with the environment to be more uniform by reducing the peak temperature of the condenser during the phase in which the compressor remains on. The attenuated heat exchange provides a reduction in the temperature of the condenser and consequently promotes an increase in the energy efficiency of the refrigerator. The advantage of reducing the number of compressor starts is that the start is the moment of greatest conversion of energy into friction between the mechanical components of the compressor. Another benefit of this reduction is the extension of the compressor’s lifespan. The COP calculated was 1.778, the work done by the compressor was 0.0958 kJ/s, the heat released to the PCM (condenser) was 0.266 kJ/s, the heat absorbed on the evaporator was 0.1704 kJ/s, and the PCM volume was 0.00115 m3. The use of PCM in condensers proved to be promising and assertive for small refrigeration systems, such as household refrigerators.
Keywords
Household Refrigerator, Phase Change Material, PCM, Computer simulation, thermo-economic analysis
