Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
THEORETICAL ANALYSIS OF AN OIL COOLER PIPE FOR THE THERMAL MANAGEMENT OF HERMETIC COMPRESSORS
Submission Author:
Thiago Dutra , SC , Brazil
Co-Authors:
Thiago Dutra
Presenter: Thiago Dutra
doi://10.26678/ABCM.COBEM2021.COB2021-0185
Abstract
Hermetic compressors have been designed in smaller dimensions and to operate in wider application envelopes. As a result, the temperature of internal components increases during operation and thermal management solutions are needed to avoid superheating of critical components, such as the electric motor. This paper presents a theoretical analysis to assess the effect of an oil cooler pipe (OCP) on the reduction of the electric motor temperature. Refrigerant fluid flows from the exit of the condenser straight through the OCP, removing heat from the lubricant oil sump inside the compressor, and cooling the electric motor. A simulation model was developed by coupling a lumped-parameter thermal model of a hermetic reciprocating compressor with a theoretical model for the heat transfer in the OCP. The compressor thermal model was validated with temperature measurements obtained from a compressor adopted for household and light commercial applications. Results show that the motor temperature decreases at the expense of a reduction in the cooling capacity, which indicates a tradeoff between compressor reliability and refrigeration system performance. Moreover, the benefit of the OCP was found to decrease at high condensing temperatures. Due to that, an extra expansion device was added in the line between the condenser and the OCP so as to control the inlet temperature in the latter. Several analyses were carried out with this new configuration and its impact on the motor temperature and system performance was evaluated.
Keywords
Hermetic Compressor, Thermal management, Simulation Model
