Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-89116-130-9

International Heat Transfer Conference 6
August, 7-11, 1978, Toronto, Canada

NATURAL CONVECTION HEAT TRANSFER IN CLOSED GAS-FILLED TUBES

Get access (open in a dialog) DOI: 10.1615/IHTC6.3280
pages 263-267

Abstrakt

This paper describes an experimental investigation of heat transfer by free convection in closed gas-filled tubes with the background of receiving knowledge about appropriate cooling arrangements for heat producing radioactive gas (Kr 85) filled in steel flasks. Variations of the heat transport properties were executed by different tube geometries, filling gases, gas pressures, inclination angles and temperature levels.

The tubes were heated by putting one end into the hole of a stove. From the other end heat was withdrawn by means of a water cooled copper finger equipped with two thermocouples serving as a differential calorimeter. Also the temperatures of the tube wall and in the gas were recorded.

In a twofold way heat transfer laws were formulated. First, we express the relations as an improvement factor concerning the heat conductivity. Second, a heat transfer law is produced with respect to a Nusselt number which includes the heat transfer from the hot wall to the gas and the appropriate effect on the cold side, regarding geometry and the angle of inclination. The results overstretch a range of length based Grashof numbers of about logl08 to log1012.