Análise termodinâmica de eficiência energética e estudo comparativo de dois sistemas de refrigeração de um auditório universitário

Abstract

For the installation of an air conditioning system, it is essential to conduct a thermal load study of the environment in order to determine the appropriate system capacity. This procedure allows for the correct sizing of refrigeration equipment and a realistic estimate of energy efficiency. The study was applied in Auditorium 2 of the Federal University of Ceará (UFC), Russas-CE campus.The thermal comfort conditions adopted were established in accordance with current Brazilian technical standards and the recommendations of ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers). The methodology consisted of a dimensional survey of the environment, complemented by the development of a twodimensional model in specific software to facilitate spatial analysis. For the calculation of the thermal load, factors foreseen in the standard were considered, such as: level of physical activity of the occupants, maximum number of people in the room, climatic characteristics of the region, geographical orientation of the building, construction typology, incidence of solar radiation during the critical period, presence of electronic equipment, type of lighting and air renewal parameters. The calculations were performed individually for each type of thermal load, using the corresponding normative equations, and subsequently summed to determine the total value. The results indicate a thermal load of 33,253.88 W (113,395.75 BTU/h). From this value, it was possible to select the equipment best suited to the auditorium's needs. Thus, the implementation of the VRV system presents itself as the most advantageous solution compared to the system already installed in the environment, guaranteeing operational savings and improved thermal comfort for the auditorium users. The analysis considers performance indicators such as COP (Coefficient of Performance), cooling capacity, energy consumption, and estimated operating cost.The results indicate that the VRV system exhibits greater energy efficiency and mechanical performance, demonstrating the system's suitability, since its annual electricity savings represent a significant reduction in the institution's operating costs, allowing for reduced energy consumption and optimized investment. It also features a fully automated system, lower noise levels, and simpler maintenance. Given this, this study aims to propose solutions for reducing the thermal load of the environment, identifying a more efficient alternative from both an energy and economic standpoint.