A comprehensive film condensation heat transfer correlation, established on the basis of analytical and empirical results from the literature, is in excellent agreement with all existing data. It incorporates the effects of interfacial shear stress, interfacial waviness, and turbulent transport in the condensate film. The usefulness of this correlation is demonstrated for annular-film condensation inside tubes. This correlation can easily be incorporated into condensing models once the interfacial shear stress is known. Two cases, cocurrent annular-film condensation inside vertical and horizontal tubes and countercurrent annular-film reflux condensation such as occurs inside the two-phase closed thermosyphon, are used to demonstrate this procedure.

General film condensation correlations

Critical heat flux

The present understanding of critical heat flux (CHF) in subcooled flow boiling with water is reviewed and fusion reactor component high-heat flux (HHF) requirements are outlined. This survey (Part...

Subcooled Flow Boiling Critical Heat Flux (CHF) and Its Application to Fusion Energy Components. Part I. A Review of Fundamentals of CHF and Related Data Base

Boiling heat transfer and critical heat flux in liquid films falling on vertically-mounted heat sources

A new set of correlations for the film flow analysis was developed to predict the critical heat flux in annular flow regime accurately. All the correlations adopted here were based on experimental data or considerations of the processes in annular flow; the resulting model required no parameters that should be adjusted from the measured data of critical heat flux. The 4,375 data of critical heat flux in forced flow of water in vertical uniformly heated round tubes were used to test the basic performance of the model. The comparisons between the calculated and measured critical heat fluxes showed that the predicted results by the present model agree with the experimental data fairly well if the flow pattern at the onset of critical heat flux condition is considered annular flow. The predictive capability was not deteriorated even in the cases of small diameter tube, short length tube as well as low vapor quality. Good agreements were also achieved in the preliminary tests against the critical heat flux dat...

https://www.tandfonline.com/doi/pdf/10.1080/18811248.2003.9715370

Prediction of Critical Heat Flux in Annular Flow Using a Film Flow Model

Critical heat flux and droplet entrainment rate in boiling of falling liquid films

Heat transfer for steam condensing inside a vertical tube

Experimental data of the condensate film thickness and the local heat transfer coefficient are presented for steam condensing in down flow inside a vertical tube. On the basis of the data obtained, the relations between the condensate film thickness, local heat transfer coefficient, film Reynolds number of condensate and shear stresses at tube wall and vapor-liquid interface are investigated and compared with the theoretical predictions for tubulent and laminar film condensation. A brass tube with an inside diameter of 24 mm was used as the test tube. The ranges of variables covered by this experiment are: 40∼90m/sec for the inlet velocity of steam, 0.2∼0.8 for the exit dryness fraction and 500∼2000 for the condensate film Reynolds number. A prediction is also presented for the thickness of laminar sublayer from the experimental data of local heat transfer coefficient by assuming that the condensate film consists of two layers, a laminar sublayer and a turbulent layer. The result indicates that the laminar sublayer thickness of condensate film is considerably different from that of single phase full tube flow.

Heat Transfer and Pressure Drop for Flow Condensation Inside a Vertical Tube

Experimental data of the heat transfer coefficient during annular flow condensation of steam inside a horizontal tube are presented and compared with the data on vertical downflow condensation and analytical predictions presented so far. Based on an ideal annular flow model, a method for predicting the heat transfer coefficient is proposed for both horizontal flow and vertical downflow.

Mitsuru Inoue

Papers

Critical heat flux and droplet entrainment rate in boiling of falling liquid films

Heat transfer for steam condensing inside a vertical tube

Heat Transfer and Pressure Drop for Flow Condensation Inside a Vertical Tube

Heat Transfer during Annular Flow Condensation of Steam inside Tubes