Generations Of Novel Asymmetric Wraps And Investigation Of Working Characteristics For Scroll Compressors

The scroll profile determines the performance of scroll compressors.The disadvantage of the existing scroll compressor with the function of asynchronous suction is that there are irreversible losses during the discharge process,because the built-in volume ratios of two working chambers are not equal,which leads the gas of different pressure to mix when the discharge port is opened.In order to deal with the above problem,in this paper,three symmetrical modified wraps were studied including a symmetrical two arcs modified wrap,a symmetrical n-pair of circular arcs modified wrap,a symmetrical circular involute modified wrap,and three asymmetrical modified wraps were proposed including an asymmetrical two arcs modified wrap,an asymmetrical n-pair circular arcs modified wrap,and an asymmetrical circular involute modified wrap.Geometric theories of six modified wraps were established,and the influence of independent geometric parameters on the performance for scroll wraps was studied.A novel asymmetric scroll compressors,with the equal built-in volume ratio of two working chambers,by using the midline design method of asymmetric two arcs modified wrap was put forward and generated.The geometric theories were established and the influence of modified parameters on the performance of the novel asymmetric scroll compressor was analyzed.The novel asymmetric scroll compressor,with the same two built-volume ratios,solved the problem of irreversible loss during the discharge process for the existing scroll compressors with the function of asynchronous suction.3D numerical simulations of the novel asymmetric scroll compressor and existing scroll compressor,during the working process,were conducted and compared in order to reveal the internal flow field characteristics;and distributions of pressure,velocity vectors and streamlines of working chambers in fluid regions were analyzed.Stresses and deformations of the orbiting and fixed scrolls caused by temperature and pressure loads were calculated.The results show that the flow field of the novel asymmetric scroll is relatively uniform,and the gas pressures in the two discharge chambers are equal.Therefore,there are not distinct airflow vortex during the discharge process.The value of stresses and deformations for the novel asymmetrical scroll compressor are smaller than those of the existing scroll compressor of asynchronous suction.Thus,the novel asymmetrical scroll compressor has better working and mechanical characteristics.This study are of great significance for promoting the development and application for scroll compressors.