Comparative Thermohydraulic Efficiency of Processes in Channels with Chaotic Packing

Resumo

A new approach to calculation of the thermohydraulic efficiency of channels with different methods of intensification including small-size chaotic packings was considered, and the corresponding expressions were obtained. For this, the Kirpichev, Antufiev, and Spalding energy coefficients, thermal efficiency of the process in the channel, and cell model of the flow structure were used. Expressions were given for calculating the temperature profiles, thermal efficiency, hydraulic resistance of channels with chaotic elements, and average Nusselt number. The results of calculations agreed with the experimental data obtained on an experimental stand with a tube-in-tube heat exchanger and oil–water heat transfer agents. Examples of calculations were given for several types of metal packing, and conclusions were drawn about the most effective designs. It was recommended to use metal chaotic packing in channels for liquids with increased viscosity because the laminar flow of the heat transfer agent changes to the turbulent one, and the heat transfer coefficient substantially increases in this case.