The Application of Microcomputer In Optimum Design and Performance Forecast of Screw Compressor

This paper has introduced the measu rement and analysis of all space cu rved surface errors of screw machinery (i ncluding single screw and twin scre w ) and the setting of functional spacefigure, thus optimizing the design paramete rs and forecasting the performance index. The measuring method designed is an ingenious combination of the mecha nism and grid with microcomputer techniq ue, and the measurement results of the corresponding framework joints of ~pace curved surface have been described in this paper. The optimum design has been obtained by theoretic derivation a nd experiment. The machinery has good effici ency and has yielded remarkable eco nomic benefits. Introduction In rotary machinery, the rotor and gate rotor of a single serew compre ssor and the rotor pairs of a twin -screw compressor are conjugate par ts. By the engagement of curved surfaces o f these parts, elementary capacity is enlarged or reduced. The surfaces also support gas pressure, and the spac e between the curved-surfaces is sprayed with lubrication oil. Finally, the pat tern and place of the discharge vent are re lated with the concrete curved surf aces. Therefore, the engaging tolerance in single screw and twin-sc~ew compressors , which have been discussed in this p aper, is essential to the performan ce index of these machines. This paper has given measuring meth ods of engaging tolerapce ( on sing le screw and twin-screw compressors), which were not accomplished by pred ecessors, such as the analysis of errors, the process of processing the errors w ith a micro-computer, and final influence on performance index. Measurement and Analysis for Engage ment Error of Twin-Screw Compressor Rot or Pairs we have experimented on a screw refrigerator, the no minal diameter of which is 200 mm. When the average engaging tolerance is reduced from 0.1 mm to 0.07 mm, the volume efficiency in creases 3%, and the adiabatic effic iency increases 0-5% or so ; With an ammon ia refrigerator whose nominal diame ter is 160 mm, when the average engagi ng tolerance is reduced from 0.07 m m to 0.04 mm, volumetric efficiency increases 4-5% under nominal working conditions. Figure 1 gives the error curves of the screw rotor ( 200 mm in nomina l diameter ) meaeured with two method s in a factory of our countrY· One uses magneto-railing techni(!ues, and th e other uses " Dynamic Gonjugatorsengaging