Studying the Frictional Power Loss in a Refrigeration Rotary Vane Compressor with a Working Fluid in Different Phase States

Abstract

The technique and results of experimental study of the antifriction characteristics of working chamber seals of promising oil-free refrigeration rotary vane compressors operating in the wet steam region are presented. The investigations have been carried out with friction in the environment of R32, R410a, and R22 refrigerants as working fluids. A significant friction coefficient drop (to 0.025‒0.05) in the wet steam environment as compared with the friction of the seals on the cylinder wall in the superheated steam environment (0.12‒0.135) has been established. It has been found that the coefficient of friction of the cylinder wall seals of oil-free refrigeration rotary vane compressors operating in the wet steam region is almost independent of the working fluid type and thickness of the liquid film on cylinder walls in the investigated range. The experimental results obtained have been used in a mathematical model for studying the energy characteristics of a refrigeration rotary vane compressor operating in the superheated and wet steam regions. The theoretical results have shown that, when a refrigeration rotary vane compressor operates in the wet steam region (by the example of an R22 refrigerant), its mechanical efficiency increases by 10% on average as compared with the operation in the superheated steam region at a rotor speed of 2000 rpm.