Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
CFD BUBBLE PUMP’S NUMERICAL SIMULATIONS FOR LiBr–H2O ABSORPTION REFRIGERATION’S CYCLE MOVED BY SOLAR ENERGY
Submission Author:
Gustavo Fernandes Soares , CE , Brazil
Co-Authors:
Gustavo Fernandes Soares, Francisco Matos
Presenter: Gustavo Fernandes Soares
doi://10.26678/ABCM.COBEM2021.COB2021-0230
Abstract
The growing use of renewable energies has the need for research in practically all possible applications, among them are the refrigeration cycles by vapor absorption. These systems are being proposed as an alternative for the climatization of hot environments in regions favored by solar irradiation such as Brazil, it is estimated that the capacity of solar irradiation in some regions of Brazil can reach 6100 Wh⁄(m^2⁄(.day)). Therefore, this work uses the absorption refrigeration cycle with the use of solar energy in the system generator, so through the use of finite volumes, the objective of the work was to simulate the flow of the fluid that occurs inside the solar collector, main component of the cycle. The finite volume model was approached with the Ansys Fluent software (2012). The development of water vapor bubbles without dispersed fluid inside the collection tubes was evaluated in order to verify if the geometric characteristics of the collector, such as diameter and length of the tubes, meet the needs of the refrigeration cycle. The nucleated boiling process was numerically simulated by Ansys Fluent and it was necessary to add a forces of interface in the governing equations, so that it is possible to analyze the phase change phenomenon more precisely. The geometry used is two-dimensional and the study was implemented with different heat flow conditions. It is important to note that the simulation model results very close to the results of experimental authors. According to the analysis using the distinct heat flow, it can be seen that the three data flows tested favorable values of steam formation along the proposed geometry. The amount of heat flow 800 W⁄m^2 and 1000 W⁄m^2 , values very close to the maximum generation of water vapor. Therefore, it is possible to infer that the model in Ansys Fluent for studying the bubble pump, is possible for a simulation of applications in which a phase change is used, which can be used in several applications in the field of industrial refrigeration and air conditioning that uses the principle of absorption cooling.
Keywords
Absorption Refrigerant, Energy solar, Bubble Pump, Computational fluid dynamics (CFD), CFD simulation, Multiphase flow modeling
