Análise comparativa entre chiller de compressor parafuso e chiller de compressor centrífugo em aplicação de termoacumulação

Abstract

Energy management stands out as one of the most important requirements in the pre paration and choice of equipment in the execution of a refrigeration project. Lack of labor specialized for maintenance, the misuse of equipment and even its useful life, are the main responsible for energy waste, however, it is necessary to use methodologies to diagnose, analyze the various situations and, based on satisfactory results, arrive at solutions that aim mainly to minimize costs and optimize efficiency system energy. Assessing the composition of the chiller equipment screw compressor and centrifugal compressor chiller, as well as their characteristics, from the conceptions described in the project calculation memorandum to the operation in the thermoaccumulation tank loading regime, it was possible to demonstrate the energy temperature variation of the two types of equipment. The fixed speed screw chiller proves to be faster than the cen trifugal chiller with variable speed for cooling the tank, that is, the energy efficiency in partial loads is increased with the speed variation, helping the compressor capacity con trol. The use of the non­standard Partial Load Value (NPLV) analysis method, described in the AHRI 550/590 standard, presented satisfactory results and of great importance for understanding the consumption in kW per TR produced by each machine. It was possible to verify that the screw chiller with NPLV of 0.79 and the centrifugal chiller with NPLV of 0.69, operate with above the available machine kW/TR values, which is 0.67 and 0.58, respectively. These values are justified by the operation occurring under par tial loads and variations throughout the night. This represents an increase in the energy consumption of each equipment.