Abo Bibliothek: Guest

ISSN Online: 2377-424X

International Heat Transfer Conference 4
August 31 - September 5, 1970, Paris-Versailles, France

ON THE EFFECT OF HELICAL-FLOW INSERTS ON BOILING PRESSURE DROP

Get access (open in a dialog) DOI: 10.1615/IHTC4.530
pages 1-9

Abstrakt

The effect of helical-flow-promoting inserts on boiling pressure drop is correlated for water and alkali metals at relatively low pressures. A constant-slip model is used. The slip ratio (mean gas velocity divided by mean liquid velocity) is approximated by the square root of the liquid-to-gas density ratio. For boilers with no inserts, the two-phase friction factor has previously been correlated as a function of mean superficial liquid, and gas Reynolds numbers. It is assumed that inserts affect pressure drop through an increase in friction factor and reduction in flow area. The two-phase friction factor is correlated herein as a function of mean superficial liquid and gas Reynolds numbers and the ratio of insert pitch to tube diameter.