ТЕПЛООБМІН ПАКЕТІВ ПЛОСКООВАЛЬНИХ ОРЕБРЕНИХ ТРУБ В УМОВАХ ВІЛЬНОЇ КОНВЕКЦІЇ І ПРИРОДНОЇ ТЯГИ

Abstract

Experimental investigations of heat transfer of two-row staggered and in-line bundles of flat-oval tubes with incomplete transversal finning in conditions of free convection and natural draft in the range of Rayleigh numbers 3000 < Ra < 30000 are performed. The difference in heat transfer in conditions of free convection and natural draft is shown, which indicates that the intensity of heat transfer of staggered and in-line bundles in natural draft conditions is 1,8 ... 2 times more than in free convection conditions. Comparison of the received data of heat transfer for staggered and in-line bundles is made. The results of the comparative analysis showed that the intensity of the heat transfer of staggered and in-line bundles under conditions of free convection and natural draft at the Rayleigh number Ra < 7000 are almost identical. At the Rayleigh number 7000 < Ra < 20000 heat transfer of the staggered bundle in conditions of natural draft is 10 ... 13% higher than of the in-line bundle.