Summary

Suction superheating acts to reduce the volumetric and isentropic efficiencies of small reciprocating compressors adopted for household refrigeration. This dissertation considers the thermal modeling of an oil-free linear compressor. The finite volume method was adopted for the solution of both the heat conduction in solids components and the flow of refrigerant inside the compressor shell. In order to reduce the computational cost, the compression cycle inside the cylinder was modeled via a transient lumped formulation, but in a coupled manner with the model for the remainder of the solution domain. The developed model was adopted to predict the velocity and temperature fields and heat flux in different regions of the compressor. In terms of temperature distribution, some difference between numerical and experimental results was observed in specific regions of solid components and gas. Nevertheless, the model presented was able to predict estimates in good agreement with measurements, especially for gas suction superheating and efficiency parameters, in four different operating conditions. The model does not require experimental calibration, being particularly useful in compressor design.

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