Heat exchange at the boiling of ozone-safe refrigerants and their oil-freon mixtures

Abstract

The object of research is the processes of heat and mass transfer during phase transitions of ozone-safe refrigerants and their oil-freon mixtures on smooth finned and capillary-porous heat-transfer surfaces of industrial heat exchange apparatuses. The purpose and objectives of the research was theoretical and experimental research of processes of heat transfer in developed bubble boiling of ozone friendly refrigerant and oil- refrigerant mixtures on smooth and developed surfaces of heat exchange by establishing relationships to determine the coefficients of heat transfer and influence of the various factors that determine the intensity of heat transfer at phase transitions in devices of refrigeration, heat pump systems and air conditioning systems; the establishment of the mechanism of heat transfer processes during evaporation of oil-refrigerant mixtures. Development of practical recommendations for the calculation and design of high-efficiency heat exchange equipment, reducing the material consumption and weight and size indicators of heat exchangers. Development and implementation of improved performance vaporizers and condensers for refrigeration, heat pump installations and air conditioning systems. For the first time, experimental studies of heat exchange processes during the boiling of refrigerants and their oil-freon mixtures on various surfaces in a wide range of thermal loads (2,9...100,8 kW / m2). Graphic dependences of the heat transfer intensity on the operating parameters of the boiling process and other characteristics are obtained. The results of the work are implemented in the technological process of VESA LLC and in the educational process of Sukhoi state technical University for lectures on the disciplines "heat and mass Transfer" and "Industrial heat and mass transfer processes and installations". The results obtained can be used in the development and creation of highly efficient evaporative heat ex-changers.