Performance Improvement of Single Screw Compressor by Meshing Clearance Adjustment Used in Refrigeration System

The single screw compressor (SSC) is widely used in air compression and refrigeration systems due to its many advantages. The meshing clearance between the screw groove and gate rotor teeth flank has a significant influence on the compressor performance. In this paper, mathematical calculation models describing the internal working process of the SSC are established in order to evaluate the thermal dynamic characteristics of the compressor under varying meshing clearance heights. The refrigerating capacity, volume efficiency and adiabatic efficiency of the SSC are calculated and discussed. Three prototypes, with different meshing clearance heights, were manufactured to study the internal influence mechanisms. The theoretical model was verified using experimental data and the calculation results strongly agreed with the experimental results. Results demonstrate that comparisons of volume efficiency and adiabatic efficiency between the measured and calculated results exhibited deviations of 3.64%–7.98% and 5.92%–9.4%, respectively. Based on the models, analysis under varying meshing clearance heights and working conditions was performed. Taking into account working performance, actual manufacturing conditions and manufacturing cost limitations, a meshing clearance height range from 0.01 mm to 0.08 mm is suggested. This study can provide important theoretical data and experimental support for the design, manufacturing and optimization of single screw compressors.