Експериментальне дослідження нестаціонарного теплообміну в суміші

Abstract

Experimental studies of the heat transfer process from the vertical cylindrical wall to the organic mixture with limited information of thermal physical processes have been carried out. The portable experimental stand, main part of which consists of two coaxial cylinders, thermocouples, device for information collection from the thermocouples and its transfer to the computer. Heat transfer coefficients from the wall are determined by means of two methods: method for stationary heat exchange processes and method of the regular thermal mode in the system «cylindrical volume filled with water – metal wall – mixture», on the condition of mixture location in the external annular channel. It was revealed that at the investigated interval the ratio for the excess temperature ln(ϑ) = f(τ) is maintained, it is typical for the regular thermal mode in the solid bodies of different forms. It was established that the discrepancy of heat transfer coefficients, determined by the method of the regular thermal mode and determined by the methods of the stationary mode does not exceed 20%. The difference is explained by the fact that the experimental studies were carried out on conditions of non-stationary heat exchange and the processing of the experimental data for the determination of the heat-transfer coefficients was performed, applying the technique, used for stationary heat exchange modes. The data, obtained as a result of the studies, prove the possibility of applying the method of regular thermal mode for the study of heat transfer intensity to viscous liquids and organic mixtures. The proposed laboratory installation and the technique of the results processing enable to assess heat transfer coefficients to the viscous liquids and mixtures with the limited information about their thermal physical properties and suggested methods of intensification of the convective heat exchange.