| 摘要 |
<p>In a heat exchanger tube having external surface enlarging elements in the form of pins, pins (18) of a certain length (11) are used in the first half of the tube length (L) in the direction of flow of the gases, and second pins (19) having a length (12) approximately equivalent to 11/cos 45° along the rest of the tube. Within a region of approximately 20 % of L, nearest to the gas inlet (12) from a combustion chamber, the length of the pins is decreased conically in known manner, so that the pin length closest to the inlet is negligible. The longer pins (19) are bent approximately 45° in relation to the longitudinal axis of the tube so that their ends remain within the contour defined by the shorter pins (18).</p> |
