NUMERICAL AND EXPERIMENTAL MODELLING OF THREE PHASE DIRECT CONTACT HEAT EXCHANGERS

1986 ◽  
Author(s):  
T. Coban ◽  
Robert F. Boehm
Keyword(s):  
Heat Exchangers ◽  
Direct Contact ◽  
Contact Heat ◽  
Experimental Modelling ◽  
Three Phase

Performance of a Three-Phase, Spray-Column, Direct-Contact Heat Exchanger

1989 ◽  
Vol 111 (1) ◽  
pp. 166-172 ◽  
Author(s):  
T. C¸oban ◽  
R. Boehm
Keyword(s):  
Heat Exchanger ◽  
Direct Contact ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Column Height ◽  
Contact Heat ◽  
Factors Affecting ◽  
Spray Column ◽  
Three Phase ◽  
New Formulation

A numerical model of a three-phase, direct-contact, spray-column heat exchanger has been developed. This model has been used to calculate performance information about this type of device and to compare, where possible, to experiments. General equations are defined for distance up the column using a physically based model for the local heat transfer. This model has been used to investigate a number of characteristics of these devices, such as temperature and holdup distributions through the column. A new formulation is given for a mixed, time-averaged temperature that may be representative of measurements taken with temperature transducers in direct-contact heat exchangers. Little has been given in the literature about quantitative variations of performance as a function of the key independent variables, and information on these aspects is presented here. Although the results presented are for a specific geometry (0.61 m diameter, 3 m active column height, evaporating pentane in 85°C water), the variations shown can give insights generally into the factors affecting performance in these devices. In virtually all cases examined here, extremely good comparisons are shown between predictions and measurements. Conclusions are drawn about the applicability of the model and the important effects demonstrated.

scholarly journals Analytical Modelling of a Spray Column Three-Phase Direct Contact Heat Exchanger

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Hameed B. Mahood ◽  
Adel O. Sharif ◽  
Seyed Ali Hosseini ◽  
Rex B. Thorpe
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Direct Contact ◽  
Relative Velocity ◽  
Contact Heat ◽  
Spray Column ◽  
Three Phase ◽  
Direct Contact Heat Exchanger

An analytical model for the temperature distribution of a spray column, three-phase direct contact heat exchanger is developed. So far there were only numerical models available for this process; however to understand the dynamic behaviour of these systems, characteristic models are required. In this work, using cell model configuration and irrotational potential flow approximation characteristic models has been developed for the relative velocity and the drag coefficient of the evaporation swarm of drops in an immiscible liquid, using a convective heat transfer coefficient of those drops included the drop interaction effect, which derived by authors already. Moreover, one-dimensional energy equation was formulated involving the direct contact heat transfer coefficient, the holdup ratio, the drop radius, the relative velocity, and the physical phases properties. In addition, time-dependent drops sizes were taken into account as a function of vaporization ratio inside the drops, while a constant holdup ratio along the column was assumed. Furthermore, the model correlated well against experimental data.

Design and Evaluation of Evaporating Lens Direct Contact Heat Exchangers

1981 ◽  
Vol 103 (2) ◽  
pp. 128-132 ◽  
Author(s):  
C. A. Kodres ◽  
H. R. Jacobs ◽  
R. F. Boehm
Keyword(s):  
Heat Flux ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Direct Contact ◽  
Lens Model ◽  
Contact Heat ◽  
Geothermal Heat ◽  
Single Lens ◽  
Explicit Procedure ◽  
Direct Contact Heat Exchanger

An explicit procedure for analyzing a superheated, evaporating lens direct contact heat exchanger has been developed. This method is based upon the application of a dimensional analysis derivation of a relationship for the heat flux from a single evaporating lens. Several suggestions are offered for use in the design of these devices. To estimate the error introduced by extrapolating a single lens model to represent a system of lenses, the method is used to “design” two operating geothermal heat exchangers. A difference of about 16 percent is observed between the calculated and measured overall heat flux.

Experimental and numerical study of direct contact heat exchangers

1985 ◽  
Vol 28 (6) ◽  
pp. 1215-1227 ◽  
Author(s):  
L. Tadrist ◽  
P. Seguin ◽  
R. Santini ◽  
J. Pantaloni ◽  
A. Bricard
Keyword(s):  
Heat Exchangers ◽  
Direct Contact ◽  
Numerical Study ◽  
Contact Heat
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