| 摘要 |
FIELD: power industry. ^ SUBSTANCE: there proposed is heat exchange surface representing metal tube finned with metal spiral; inside spiral there located is metal wire with the specified linear expansion coefficient, which is installed inside spiral turns with preliminary tightening. Thermal expansion coefficient of wire metal inside spiral is chosen so that when operating temperature of heat exchange surface is more than ambient temperature, then linear expansion coefficient of the inserted wire is chosen less than linear expansion coefficient of tube metal and finning; if operating temperature of heat exchange surface is less than ambient temperature, then linear expansion coefficient of the inserted wire is chosen so that it is higher than linear expansion coefficient of metal of tube and finning; as a result, thermodynamic effectiveness of tube finning is increased at temperature variation from ambient temperature to operating temperature of heat exchange surface due to additional tightening of fin to tube surface and increase of contact spot of fin and surface of tube. ^ EFFECT: increasing thermodynamic efficiency of finning owing to lower thermal resistance in contact zone. ^ 1 dwg |
