No abstract

Twin-screw refrigeration compressors have been widely used in many industry applications due to their unique advantages. The performance of twin-screw refrigeration compressors is generally predicted by one-dimensional numerical simulation or empirical methods; however, the above methods cannot obtain the distribution of the fluid pressure field and temperature field inside the compressor. In this paper, a three-dimensional model was established based on the experimental twin-screw refrigeration compressor. The internal flow field of the twin-screw compressor was simulated by computational fluid dynamics (CFD) software using structured dynamic grid technology. The flow and thermodynamic characteristics of the fluid inside the compressor were analyzed. The distribution of the internal pressure field, temperature field, and velocity field in the compressor were obtained. Comparing the P-θ indicator diagram and the performance parameters of the compressor with the experimental results, it was found that the results of the three-dimensional numerical simulation were consistent with the experimental data. The maximum error was up to 2.578% on the adiabatic efficiency at the partial load working condition. The accuracy of the 3D numerical simulation of the screw compressors was validated and a new method for predicting the performance of twin-screw refrigeration compressors was presented that will be helpful in their design.

：Twin-screw refrigeration compressors have been widely used due to their unique advantages, but owing to their complex rotor structure and profile design. The performance of twin-screw refrigeration compressors is generally predicted by one-dimensional numerical simulation or empirical methods, but this kind of method cannot obtain the distribution of the fluid pressure field and temperature field inside the compressor. A three-dimensional model is established based on the experimental screw compressor. The internal flow field of the twin-screw compressor is simulated by CFD software using the structured dynamic grid technology. The flow and thermodynamic parameters of the fluid inside the compressor are analyzed. The distribution of the internal pressure field, temperature field and velocity field of the compressor is obtained. Comparing the P-V indicator diagram and the macroscopic performance parameters of the compressor obtained by three-dimensional numerical simulation with the experimental results, it is found that the simulation results are basically consistent with the experimental data. The error is large at part load, and the maximum error is the adiabatic efficiency, which is 2.58%. Numerical simulation can accurately predict the performance of twin-screw compressor and provide a new method for compressor design.