Research of Hydraulic Resistance and Heat Transfer in Elements of Pipe Columns with Alternate Arrangement Located in Gas Pipes behind the Screen of Hot-Water Boiler

Abstract

In modern designs of hot-water boilers, depending on design layout and arrangement of external screens with furnace cage presented by membrane panels, there appears a channel with longitudinal and cross runaround in cross-section of gas pass. Whereas cross-section of such channel differs from traditional forms, thoroughly researched and presented in academic publications. In this paper there are presented results of experimental researches on determination of hydraulic resistance and coefficient of heat transfer for particular convective elements of boilers with new configuration – membrane type furnace screens and swirler device at gas pass located behind the screens. It is shown that in gas pass with swirler device located behind the screens, in case of cross runaround of tubes and high temperature of gases (870÷970)°K, one can expect the increase of heat transfer coefficient in comparison with classic alternate arrangement of tube columns with large amount of tubes in cross row.