2013 年 30 巻 1 号 p. 99-106
In this study, calculations of the mechanical efficiency of a large reciprocating compressor, developed by Mayekawa MFG. Co., Ltd., with a per cylinder suction volume of 1300 cm3 were carried out. These calculations were used to confirm whether the empirical combination of major design parameters in the Mayekawa compressor delivers optimal mechanical efficiency. Initially, the theoretical equation of motion of the rotating crankshaft is developed. Subsequently, computer calculations are carried out to determine the mechanical efficiency for various combinations of the major design parameters for operating speeds of 800, 1000 and 1200 rpm. From these calculations, the optimal combination parameters yielding the maximum mechanical efficiency could be determined, and then compared with the empirical combination used in the Mayekawa compressor. The maximum mechanical efficiency reaches 91.1% at the operating speed of 1000rpm, with a combination of the piston stroke of 40mm and the piston diameter of 130mm, which agree well with the design values of conventional compressor. An attention should be paid to the characteristics of optimal combination, depending upon the operating speed, where the selection of optimal combination at the average operating speed is recommended.