Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
MATHEMATICAL MODELING OF AN AIR CONDITIONER TO SIMULATE THE COOLING OF SPACES
Submission Author:
Flávio Júnior Santiago Silva , PR
Co-Authors:
Flávio Júnior Santiago Silva, Wellington Balmant, Diego de Lima Sousa, Iago Gomes Costa, JOSÉ VIRIATO COELHO VARGAS, André Bellin Mariano
Presenter: Flávio Júnior Santiago Silva
doi://10.26678/ABCM.ENCIT2022.CIT22-0498
Abstract
With the development of the economy and industry, the demand for energy has increased significantly, since according to the latest energy balance provided by the Ministry of Mines and Energy, the industry sector showed an increase of 3 million tons of oil equivalent in the final consumption of electricity, and within this sector, there are the subsectors of HVAC and Refrigeration that stand out for their self-spending. Based on this scenario, the absorption refrigeration system is a promising alternative in being able to use thermal energy from renewable sources, in addition to using working fluids with low environmental impact compared to traditional refrigeration systems. With this, this work presents mathematical modeling of an absorption refrigeration system to simulate the air conditioning of two spaces. For this, the development of the mathematical equations of the model was based on the application of the principles of conservation of mass and energy in a transient regime for the components refrigerator, reservoir, two fan coil, and two spaces, where each component was modeled as a simple control volume. After the mathematical model was developed, a computational code was developed in Fortran 90 language, in order to obtain numerical answers for each control volume and thus carry out analyzes according to the system parameters. The mathematical model resulted in a system of ordinary differential equations (ODEs) that was solved by integrating in time with the help of the Runge-Kutta-Fehlberg method of 4th/5th order and interacting, simultaneously. As a result, this article resulted in the input profiles of the temperature of the thermal fluids of each control volume, as well as the cooling time in each environment. The Coefficient of Performance(COP) for the first air-conditioned space was 0.54 (COP = 0.54) and when two spaces cooled the COP was 0.25 (COP = 0.25), and optimizations were also performed in some parameters, thus evaluating the influence of these parameters as a function of system operation via computer simulation. In this way, it is possible to conclude that the proposed mathematical model can be used as a useful tool for simulation in different conditions of operation, control and, thus, avoid future problems in the installation of the system in environments, in addition to performing analyzes for optimization of the main components. of an absorption refrigeration system.
Keywords
Absorption refrigeration, mathematical model, Computational simulation
