Parametric study for performance of small size hermetic reciprocating compressors

Abstract

The recent remarkable effects of global warming and a noticeable rise in power consumption are leading to major research on household refrigerators. In addition to that, alternative refrigerants have opened a new room for improvement of the compressor. Parametric analysis on compressor performance has a high demand for understanding their effect and parametric significance. To address the issue, this study presents the effect of critical parameters: cylinder bore, ports (suction, discharge), valve system (suction, discharge), muffler (suction, discharge), test condition, refrigerant type, and motor rotational frequency on compressor performance. The Performance of the compressor has been evaluated in terms of refrigerant flow rate, power consumption (PV power), power loss due to over-compression (over-pressure loss), and under-expansion (under-pressure loss). Analysis of temperature distribution at various locations adored the study further. However, a one-numerical model of a hermetic reciprocating compressor has been developed and validated before that. Conservation for mass, momentum, and energy balance equations have been used to characterize the physical processes across the fluid domain. Moreover, Euler-Bernoulli thin beam theory has also been used for valve reed dynamics. These equations have been discretized by explicit forward and central difference techniques. The numerical forms of those equations have been applied at each relevant node and solved to evaluate fluid state, flow, and other geometric parameters. The fluid and structural domains have also been coupled by transferring relevant parameters across them. This study reveals a significant correlation of the stated parameters with compressor performance. Refrigerant flow rate, PV power, and under–expansion loss have been observed to be critically influenced by the investigated parameters related to cylinder bore, suction port, and suction valve system. Discharge port, discharge valve system have been observed to have the primary impact on the PV power and over-compression loss. Test condition, refrigerant type, and rotational frequency of motor have been observed to have significant parametric significance on refrigerant flow rate, PV power, over-compression loss, and under-expansion loss. These key observations of this study are hoped to open a new room for further follow-up research to address both the regional and global challenges.