Application of indirect circulation loops with carbon dioxide in refrigeration cycles

Abstract

The paper provides with a review of indirect cooling systems with a circulation loop with carbon dioxide as a working fluid. A technical solution was also proposed, consisting in coupling a propane compressor cooling system unit with a two-phase CO2 loop. A general calculation approach was presented for the flow resistance occurring in the installation because of the prepared maps of two-phase flow patterns in the horizontal and vertical channels. The focus of the calculations was to determine the appropriate height of the liquid column to enable proper operation of the system. The paper is an introduction to the currently undertaken development works on innovative solutions of indirect refrigeration systems for commercial refrigeration.