Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Development and characterization of a calibrated calorimeter to evaluate air conditioning systems
Submission Author:
Maria Claudia Régio e Silva , SC , Brazil
Co-Authors:
Maria Claudia Régio e Silva, Gabriel Martins do Rosario, Sergio Luiz Dutra, Matheus Capovilla, Rafael Valdir de Lima, Anderson Lorenzoni, Diego dos Santos, Gislaine Hoffmann, Guilherme Fidelis Peixer, Jaime Lozano, Jader Riso Barbosa Jr.
Presenter: Maria Claudia Régio e Silva
doi://10.26678/ABCM.COBEM2021.COB2021-1992
Abstract
Validation and characterization of air conditioning (AC) systems can be an expensive and onerous stage on the development of these equipment. Among several options established by the ruling standards, calorimeter methods are widely used both in academic and industrial environments. The objective of this work is to design and characterize a calibrated calorimeter for validating the performance of AC systems and to compare their results with those obtained from tests performed with a certificated calorimeter. The main goal of the apparatus is not to certificate AC, but rather to provide reliable performance data for these systems, in special a magnetic refrigeration system under development at POLO Laboratories. The device is a 10.7 m² calibrated calorimeter divided into two chambers thermally isolated from each other: the cold side (CS), for the evaporator unity of the AC, and the hot side (HS), for the condenser unity. The area surrounding the calorimeter is called outside (OS) and it refers to the room where it is situated. Given the goal of the apparatus and budget, equipment and physical space restrictions, this design is based on the standard’s recommendations, although it does not follow all its imposed demands. Among the main adaptations, the humidity control is present only at the CS chamber and, for the purpose of supporting and better accommodating the magnetic cooling prototype, the base of the HS is in direct contact with the OS floor. Nevertheless, temperature controls are measure by 9 thermocouples in the CS, 9 in the HS and 7 in the OS. Temperature control in the CS is performed through electrical heaters, in the HS by a chiller coupled to fan-coil and in the OS by ambient air-conditioners. Once the calorimeter was built, a characterization stage of the apparatus was performed, wherein the objective was to experimentally evaluate the heat transferred through the walls of the device. An average global heat transfer coefficient, for the conditions under which the AC will be tested, was obtained for the walls in contact with the OS, which for the CS is 0.568 W/(m²K) and for the HS is 0.843 W/(m²K). Lastly, for the purpose of evaluating the impact of such adaptations in the obtained results, a reference air-conditioner, which was previously evaluated with a certificated calorimeter, was tested with the apparatus. The results were compared and used for calibrating the developed calorimeter for future tests performed on it.
Keywords
calorimeter method, calibrated calorimeter, thermodynamic characterization, air conditioning system characterization, performance comparison
