Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
DESIGN OF A COOLING MACHINE OPERATING WITH CO2 IN SUBCRITICAL CYCLE
Submission Author:
Sabrina Nogueira Rabelo , MG
Co-Authors:
Carlos Henrique Neto da silva, Hélio Augusto Goulart Diniz, Neylor Makalister Ribeiro Vieira, STELLA MARYS SILVA PINHEIRO, Sabrina Nogueira Rabelo
Presenter: Sabrina Nogueira Rabelo
doi://10.26678/ABCM.ENCIT2018.CIT18-0042
Abstract
The purpose of this work is to design an ar-water cooling machine using components that operate with CO2 (R744) in a subcritical cycle. The machine has a concentric tube condenser option (coaxial) with counter-current flow and a cross-flow finned tube evaporator option. It was also used an alternative semi-hermetic compressor and an electronic expansion valve. The components were designed and selected based on mass and energy equations. The specialized literature was consulted for the acquisition of mathematical models more suitable for the project of heat exchangers, which were programmed in the MATLAB® (MATrix LABoratory) software, assisted by the EES® (Engineering Equation Solver) software. The refrigeration capacity of the evaporator was 3.47 kW, operating at a pressure of 19.7 bar and at an evaporation temperature of - 20 °C. The heat exchange rate between the fluids in the condenser was 4.82 kW, working at a pressure of 45.02 bar and at a condensing temperature of 10 °C. The projected machine has a cycle COP (Coefficient of Performance) of 3.47, which can be used by a research laboratory and will allow the production of cold air at 8.1°C, which can be used to aid in the air conditioning of laboratory rooms and can also be applied in laboratory tests of domestic refrigeration machines.
Keywords
Refrigeration machine, Cooling system, project, subcritical cycle, R744
