EXPERIMENTAL INVESTIGATION OF A NONSTANDARD LAYOUT OF A MULTIROW HORIZONTAL FINNED-TUBE BUNDLE WITH AN EXHAUST SHAFT

In view of the fact that heat exchangers made of bimetallic fi nned tubes have found wide application in contemporary technology for the regime of natural convection, it became necessary to take into account the radiative component that may be appreciable in the total heat fl ux and that depends on the geometric parameters of the bundle and characteristics of the surface studied. It is suggested in the article to raise the heat power of a multirow fi nned bundle by applying a nonstandard layout of tubes by placing their upper row above the exhaust shaft, with the remaining ones under the shaft. From the results of experimental investigations and of a comparative analysis of heat transfer by radiation and convection of a multirow fi nned-tube heat transfer bundle with an exhaust shaft and different layouts of tubes, it is shown that the nonstandard layout of fi nned tubes of a multirow heat exchanging bundle makes it possible to increase the radiant heat fl ux by 1.4–1.5 times. In this case, the total heat transfer rate of the bundle with the use of a nonstandard layout is increased approximately by 5%. It is shown that it is worthwhile to optimize the layout of the bundle when the fraction of the radiant fl ux in the total heat fl ow exceeds 10%.
   
Author:  A. B. Sukhotskii, E. S. Danil′chik, and G. S. Marshalova
Keywords:  fi nned tube, exhaust shaft, zone method of calculation of a radiant heat fl ux, natural convection of air
Page:  1079