Projeto de dimensionamento e seleção de equipamentos para uma câmara frigorífica de congelamento de carnes e resfriamento de laticínios

Abstract

The food industry condenses one of the biggest applications of industrial refrigeration, be it in the development, storage or distribution of food. Applying knowledge of refrigeration and heat transfer, the present paper has as objective describe the steps of dimensioning a cold store for a supermarket located in the city of Corumbá - MS, with a freezing demand of 15 T/day of beef and cooling of 5000 L/day of curd. In order for the project to be developed, the storage characteristics of the food under study, such as temperature and storage volume, were initially collected. With this information, the dimensioning of the thermal load of the beef and curd chambers was carried out taking into account the product loads, infiltration, heat transmission, people, lighting and equipment. The entire calculation was developed according to the ASHRAE refrigeration manual and using the Engineering Equation Solver (EES) software. For the meat chamber a total thermal load of 269,562 kcal/h was obtained, while for the curd chamber the calculated load was 32,674 kcal/h. In addition, the product storage shelves and cold rooms were dimensioned and designed in CAD, with 58.86 m2 and 54.94 m2 areas for the meat and curd chambers, respectively. Using the thermal load data, refrigeration equipment was selected by consulting supplier catalogs. To meet the demand of the chambers, 5 evaporator units with a nominal capacity of 61,946 kcal/h were selected to freeze the meat and 1 evaporator with a capacity of 42,009 kcal/h to cool the curds. For the stages of compression and condensation, 9 condensing units were chosen with a cooling power of 32,719 kcal/h for meat and only 1 condensing unit with a capacity of 32,854 kcal/h for curds. The equipment operates with R-404A refrigerant. The costs of the project were estimated at around half a million reais, not including freight and installation, with electrical refrigeration equipment comprising approximately 82% of the total value of the project (511,007.00 reals).