Analytical Study of Flow Regimes for Direct Contact Condensation Based on Parametrical Investigation

2005 ◽  
Vol 127 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Anka Petrovic
Keyword(s):  
Direct Contact ◽  
Analytical Study ◽  
Nuclear Reactor ◽  
Flow Regimes ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Jet Pumps ◽  
Different Shapes ◽  
Contact Condensation ◽  
Limited Accuracy

Various industrial devices exist where direct contact condensation (DCC) of steam in water takes place. Typical examples are the nuclear reactor coolant systems, steam driven jet pumps, and condensers. The modeling of steam condensation is crucial to obtain an appropriate design of such devices. Present models designed for DCC have shown limited agreement with experimental data. Computation of the flow regimes is performed with limited accuracy, due to initial model settings and empirical correlations, which form a main drawback in the computation of DCC related problems. This study, which is a part of a PhD study, presents an investigation of the steam-water interface for various conditions of steam and water, using the computation of balance equations and jump conditions. A simple mathematical model to predict the location of the condensation interface for four different shapes of steam plume at different heat transfer coefficients is presented which will be further developed into an advanced computational model for DCC.

Analytical Study of Flow Regimes for Direct Contact Condensation Based on Parametrical Investigation

2004 ◽  
Author(s):  
Anka Petrovic
Keyword(s):  
Direct Contact ◽  
Analytical Study ◽  
Nuclear Reactor ◽  
Flow Regimes ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Jet Pumps ◽  
Different Shapes ◽  
Contact Condensation ◽  
Limited Accuracy

Various industrial devices exist where Direct Contact Condensation (DCC) of steam in water takes place. Typical examples are the nuclear reactor coolant systems, steam driven jet pumps and condensers. The modelling of steam condensation is crucial to obtain an appropriate design of such devices. Present models designed for DCC have shown limited agreement with experimental data. Computation of the flow regimes is performed with limited accuracy, due to initial model settings and empirical correlations, which form a main drawback in the computation of DCC related problems. This study, which is a part of a PhD study, presents an investigation of the steam-water interface for various conditions of steam and water, using the computation of balance equations and jump conditions. A simple mathematical model to predict the location of the condensation interface for four different shapes of steam plume at different heat transfer coefficients is presented which will be further developed into an advanced computational model for DCC.

An Experimental Investigation of OC-OTEC Direct-Contact Condensation and Evaporation Processes

1984 ◽  
Vol 106 (1) ◽  
pp. 120-127 ◽  
Author(s):  
R. G. Sam ◽  
B. R. Patel
Keyword(s):  
Heat Transfer ◽  
Direct Contact ◽  
Turbulent Jets ◽  
Operating Conditions ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Air Content ◽  
Thermal Energy Conversion ◽  
Ocean Thermal Energy ◽  
Contact Condensation

Heat transfer data are presented for direct-contact evaporator and condenser geometries suitable for Open-Cycle Ocean Thermal Energy Conversion (OC-OTEC) applications. Falling turbulent jets and films were tested at typical operating conditions. The flash evaporator performance was relatively constant over the range of conditions tested, with efficiencies as high as 95 percent due to the breakup of the jets (or films) into sprays. The condenser performance was only affected by the jet or film Reynolds number and the steam air content. Condenser heat transfer coefficients of the order of 27 kW/m2 °C were achieved with jets which were higher than those obtained with films. An empirical correlation was developed for the condenser data after it was shown that none of the existing correlations found in the literature could correlate all of the data trends observed.

Determination of heat transfer coefficients in direct contact latent heat storage systems

2018 ◽  
Vol 145 ◽  
pp. 71-79 ◽  
Author(s):  
Sven Kunkel ◽  
Tobias Teumer ◽  
Patrick Dörnhofer ◽  
Kerstin Schlachter ◽  
Yohana Weldeslasie ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Latent Heat ◽  
Direct Contact ◽  
Heat Storage ◽  
Storage Systems ◽  
Transfer Coefficients ◽  
Latent Heat Storage ◽  
Heat Transfer Coefficients

Prediction of Horizontal Tubeside Condensation of Pure Components Using Flow Regime Criteria

1980 ◽  
Vol 102 (3) ◽  
pp. 471-476 ◽  
Author(s):  
G. Breber ◽  
J. W. Palen ◽  
J. Taborek
Keyword(s):  
Heat Transfer ◽  
Prediction Method ◽  
Local Heat Transfer ◽  
Flow Regimes ◽  
Local Heat ◽  
Pure Component ◽  
Liquid Volume ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Horizontal Tubes

In order to select the appropriate correlations for prediction of horizontal tubeside condensation heat transfer coefficients, it is necessary to estimate what types of flow patterns exist at various points along the tube. The main criteria required are shown to be the ratio of shear to gravity forces on the condensate film and the ratio of vapor volume to liquid volume. A recently proposed prediction method by Taitel and Dukler is compared with observed flow regimes for condensation in horizontal tubes. The theoretically obtained parameters are shown to characterize the flow regimes well. Based on these parameters, a simplified procedure for prediction of local heat transfer coefficients for pure component condensation in horizontal tubes is proposed.

Sign in / Sign up

Export Citation Format

Share Document