Condensation of a Vapor-Gas Mixture Containing Solid Particles on the Surface of Finned Pipes

The operation of some heat exchangers entails condensation of a vapor-gas mixture. If this mixture contains solid particles, they are deposited during the condensation on the outer finned surface. After the liquid flows off, a layer of sediment from solid particles is formed on the finned pipe outer surfaces. A mathematical description of the sediment layer formation on the outer surface of an annular circular straight fin of constant thickness on a cooled pipe during the condensation of a vapor-gas mixture containing solid particles has been developed. Using the developed mathematical model, equations for calculating the temperatures and thickness of the sediment layer in dimensionless form are obtained. Dependences of the change in heat flux on the temperature difference between the fin and environment, fin thickness, and the thermal conductivity coefficients of the sediment and fin are derived. It has been found that, as the temperature difference between the fin and the environment increases from 10 to 50°C, the heat flux increases by a factor of 0.29, and as this temperature difference increases from 10 to 100°C, the heat flux increases by a factor of 0.17. Significant changes in the heat flux are observed in the first 10 days. It can be seen from the study results that with an increase in the temperature difference between the fin and environment, the difference in heat flux values becomes more significant. After 10 days, a smooth change in the heat flux values is observed.