Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
NUMERICAL ANALYSIS OF THE THERMODYNAMIC PERFORMANCE OF AN ACTIVE BAROCALORIC REGENERATOR USING PDMS RUBBER FOR REFRIGERATION APPLICATIONS
Submission Author:
Pedro Faria , MG , Brazil
Co-Authors:
Pedro Faria, Kimi Portugal, Alexandre Magnus Gomes Carvalho, Paulo Vinicius Trevizoli
Presenter: Pedro Faria
doi://10.26678/ABCM.COBEM2021.COB2021-0195
Abstract
Though vapor compression technology for heating and cooling applications is widespread in society, restrictions imposed upon the working fluids are escalating, whether they are relative to environmental impact, user safety, or energetic performance of the equipment. It is estimated that about 5 million refrigerators, air-conditioners, and heat pumps are used around the world, being responsible for the consumption of 20% of all the energy produced. This context motivates research on alternative technologies, notably i-caloric effects in solid-state refrigerants. Among the i-caloric effects, stand out the barocaloric effect (driven by mechanical stress - compression) which, despite being the less explored might be, along with the elastocaloric effect, the most promising alternative to vapor compression systems, due to the high adiabatic temperature change. This work aims to make up for the scarcity of theoretical models to evaluate the real potential of active barocaloric regenerators using elastomers for heat pumping applications. The proposed 2D model uses parallel plates as geometry of the regenerative matrix, being each plate composed of an inner layer of a barocaloric elastomer between two outer layers of a metallic material. These outer walls have the role of constraining the lateral expansion of the inner layer that would, otherwise, be caused by the compression in the axis perpendicular to the flow direction. The fluid flow through the regenerator bed, between the flat plates, is driven by a sinusoidal pressure gradient and is simulated according to an analytical solution obtained from the Navier-Stokes equation after several simplifications. The heat transfer problem in the two solids and in the fluid is modeled by the Energy Conservation equations for each phase and solved by the Finite Volume Method, thus constituting an analytical-numerical hybrid model. Cooling capacity results are evaluated as a function of the fluid flow rate, temperature span and geometric parameters of the device. Temperature profiles along the regenerator bed and temperature transients are also evaluated to understand the thermal behavior of the proposed system.
Keywords
Active Caloric Regenerator, Barocaloric Effect, Elastomers, Refrigeration, Finite volume method
