Monitoring and Control of a Cooling System in a Commercial Store

This paper presents a case-study for the optimization, the monitoring and the automatic control of a refrigeration system in a commercial store. The existing controllers were replaced by Omron temperature controllers, connected to an industrial network and linked to a central computer for data monitoring and temperature control using a LabView software. In case of an alarm occurrence, this system includes a routine that automatically sends a GSM message to alert the person responsible for the store. This functionality is not yet available in commercial systems. The objective of a refrigeration plant is to cool down articles or substances and maintain them at a temperature lower than the ambient temperature. Therefore, refrigeration can be defined as a process that removes heat. Refrigeration systems are thus fundamental to ensure the quality and preservation of the various products in the food industry, including the conditioning store of perishable food products and the conservation of pre-frozen products. Refrigeration slows down the proliferation of bacteria in food: the technique used in practice is based on the extremely rapid and intense action of the cooling effect, which allows the organoleptic properties of the food to be preserved, thus extending the conservation time. In the cooling process two methods are used: mechanical refrigeration and refrigeration by ice (1): • In Mechanical Refrigeration refrigerant fluids are used. The fluid follows through the different stages of the system, where heat is absorbed and transported to another area, through fluid compression, condensing, expansion and evaporation processes. A refrigerant, therefore, must have properties whereby it evaporates at a low temperature and pressure, absorbing heat, and then gives up this heat by condensing at a higher temperature and pressure. This procedure requires energy.