EXPERIMENTAL STUDY OF THE INDICATOR DIAGRAM OF A SINGLE-STAGE RECIPROCATING COMPRESSOR AT DIFFERENT CRANKSHAFT ROTATION SPEEDS

Abstract

This paper presents the results of an experimental study of the working process of a single-stage reciprocating compressor at different crankshaft rotational speeds. The main objective of the research is to determine the influence of rotational speed on the thermodynamic processes inside the cylinder and the energy performance of the compressor. During the experiment, the compressor was tested at operating modes of 600, 800, and 1000 rpm, and pressure–volume (p–V) indicator diagrams were obtained. Based on these diagrams, the suction, compression, and discharge processes were analyzed, and the indicated work of the compressor was evaluated. The results show that as the rotational speed increases, the volumetric efficiency of the cylinder decreases. This phenomenon is explained by the reduction of suction time and the increase in dynamic losses. In addition, at higher rotational speeds the inertial effects of the valves become more significant, which leads to an increase in mechanical and thermal losses. As a result, the reduction of the indicator diagram area indicates a decrease in the energy efficiency of the compressor. The experimental data obtained in this study can be used for diagnosing compressor operating modes and determining optimal speed parameters. Overall, the study confirms that rotational speed is an important factor that directly affects the efficiency of reciprocating compressor operation. The obtained results can be applied to reduce energy losses and improve the reliability of compressor units in industrial applications.