Optimization of screw compressor design

Ever increasing demands for efficient screw compressors require that compressor designs are tailored upon their duty, capacity and manufacturing capability. A suitable procedure for optimisation of screw compressor shape, dimension and operating parameters is described here, which results in the most appropriate design for a given compressor duty. It is based on a rack generation algorithm for rotor profile combined with a numerical model of the compressor fluid flow and thermodynamic processes. Compressors thus designed achieve higher delivery rates and better efficiencies than those using traditional approaches. Some optimization issues of the rotor profile and compressor parts are discussed, using a 5/6-106 mm screw compressor to illustrate the results. It is shown that the optimum rotor profile, compressor speed, oil flow rate and temperature may significantly differ when compressing different gases or vapours.