Analysis of the Influence of Thermophysical Properties of a Droplet Liquid on the Work Processes of a Two-Stage Piston Hybrid Power Machine

Abstract

The article considers the influence of the main thermophysical properties of the power liquid on the working processes and energy characteristics of a new highly efficient two-stage piston hybrid power machine designed to compress gas to medium and high pressures. Mathematical model of the working processes of the machine under study with a pro-filed working chamber of stage 2 has been developed. To verify the developed mathematical model of working processes, a prototype and a stand for its study were created. The visualization of the movement of the liquid piston, measurement of the instant pressure in the working chamber of the machine, energy and consumption characteristics verified the developed mathematical model. As a result of a numerical experiment, we determined that there is an optimal value of the dynamic viscosity of the power liquid, which depends on the angular velocity of the crankshaft and is in the range from 0.005 to 0.02 Pa∙s, with large values referring to large values of the angular velocity. With a decrease in the density of the power liquid, the work of friction forces decreases and the total indicator efficiency increases. The findings of the research can be used when choosing coolants in reciprocating compressors with a liquid piston.