Summary

Scroll compressors perform the compression process by using two identical inter-fitting, spiral-shaped scroll elements. Such elements are mounted inverted and rotated 180! in relation to each other and, by making contact with each other at sealing points, form multiple compression volumes. The thermodynamic efficiency of scroll compressors is a.ected by heat transfer that takes place during both the suction and the compression processes. Two lumped-parameter thermal models were developed and experimentally calibrated to predict the temperature distribution of scroll compressors with particular attention given to gas superheating in the suction process. Thermal resistances between the components were based on global heat transfer coefficients, whereas conduction heat transfer through the scroll wraps was solved via a one-dimensional finite volume method. The thermal models were coupled to a thermodynamic model of the compression cycle and then applied to simulate the compressor performance under di.erent conditions of speed and pressure ratio. The models were able to correctly predict the compressor temperature distribution for operating conditions within the range of those adopted for its calibration. The model demonstrated that heat conduction through the scroll wraps reduces slightly the discharge temperature. Moreover, it was also observed that the heat transfer that takes place during the metallic contact between scroll wraps acts to produce a linear temperature variation along their length.

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