| 摘要 |
Condensing heat exchanger flue tube for installation in the holes of a tube sheets of the heat exchanger has a dents (2) formed along the length of the tube (1), and said dents (2) are pointed towards the inside of the tube (1), and said dents (2) are positioned opposite each other, and two opposite dents (2) mark out a section, where the distance between the lowest points in the dents (2) measured inside the tube (1) in the section is 1.0 mm or less, and the ratio of the length (L) of the tube (1) to the tube cross section circumference around which the combustion gases flow falls within the range from 2.5 to 6.5. The maximum outer linear dimension of the tube's (1) cross section at any point along its length, corresponding to the maximum diameter of the circle circumscribed on the outer contour of that cross-section, is not greater than the minimum transverse linear dimension at its upper and/or lower end, corresponding to the minimum diameter of the circle inscribed within the outer contour of the upper and/or lower end of the tube (1). |
