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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

STRAIGHTFORWARD DESIGN FORMULAE FOR EFFICIENCY AND MEAN TEMPERATURE DIFFERENCE IN SPIRAL PLATE HEAT EXCHANGERS

Get access (open in a dialog) DOI: 10.1615/IHTC8.1280
pages 2793-2797

Résumé

The system of ordinary differential equations for the temperature distribution in spiral plate heat exchangers has been solved numerically to obtain the efficiency and the logarithmic mean temperature difference-(LMTD-) correction factors (F) as a function of the number of transfer units (N), the number of turns (n), and the heat capacity rate ratio (C). It has been found that the LMTD correction factors, when plotted versus number of transfer units per turn (N/n) fall approximately on a single curve. That curve could be very closely represented by the simple formula F = (n/N)·tanh(N/n). From that simple analytic representation of our numerical results it was concluded that a simpler physical model might exist to represent the overall behaviour of a spiral plate heat exchanger equally well. In fact a countercurrent cascade of n cocurrent heat exchangers does exactly result in the above mentioned formula for the LMTD correction factor.