Desenvolvimento de programa para dimensionamento da carga térmica e seleção das unidades condensadora e evaporadora: sistemas frigoríficos de pequeno porte

Abstract

Cold rooms are used, in commercial and industrial companies, as one of the main refrigerated compartments that have the capacity to store and preserve products, such as: meat, fish, vegetables, fruits and varieties. Therefore, the objective of this work is to develop a program for sizing the thermal load and selecting condenser and evaporator units for small refrigeration systems, using the MATLAB platform as support for implementing the algorithm. The research was developed by determining the total daily thermal load of cold rooms by calculating the heat portions, sizing the thermal load and, thus, selecting the condenser and evaporator units. The numerical model developed allows the selection of this equipment depending on the type of refrigeration chamber, whether frozen or chilled, type of insulation, type of product, among other parameters. A comparative analysis was carried out to verify the numerical model developed, testing different scenarios, such as: products to be stored, defrosting time, safety factor and percentage value of engine power. Regarding the products used to carry out the analyses, three types of products with different categories were randomly chosen, namely: milk, cod and poultry. Among the parameters analyzed, defrosting time is essential in the operational method of the cold room. From the results found for the total thermal load, with defrosting times of 2h and 6h, a percentage increase in the total thermal load of 22% was obtained approximately. Finally, the results obtained highlighted the efficiency of the program, which can be used in research and work in the area of refrigeration and air conditioning.