Technical field: Extended surface enhanced heat transfer technology

Production process: Formed by hot rolling and extrusion of thick walled seamless steel pipes. The specific production process is as follows: The thick walled seamless steel pipe is subjected to 2000Hz-2500Hz intermediate frequency induction and applied to 900-950 º C, and automatically enters three sets of specially designed rolling blades with a circumferential distribution of 120. The thick walled seamless steel pipe is rolled into a spiral finned tube with wall thickness, wing height, wing pitch, and wing shape meeting the requirements at once (I. E., the part of metal with reduced wall thickness undergoes plastic deformation to form a spiral finned tube with wing height, wing pitch, and wing shape meeting the requirements), and the fins are integrated with the pipe, with a flat and smooth surface.

Technical leadership level. Exclusive domestic production

Technical advantages: The spiral finned steel pipes currently used are mostly wound, frequency welded, and brazed spiral finned steel pipes. The integral spiral finned steel pipe has become a replacement product for the above three forms of spiral finned steel pipes due to its long service life, stable heat transfer performance, and obvious energy-saving effect.

Its advantages are reflected in the following aspects:

1. Long service life, more than three times that of wound welded finned steel pipes.

2. The use of integral spiral finned steel pipe design or modification of the economizer (heat exchanger) effectively solves problems such as high exhaust temperature, dust accumulation and wear of the economizer. The root of the fins forms an arc cut with the pipe, and the surface of the fins is smooth, completely eliminating the dust accumulation, blockage, and slagging caused by uneven folding of the fin roots in other forms of finned pipes.

3. The use of hot rolling technology in production has improved the density, yield strength, tensile strength, and wear resistance of the metal structure.

4. Due to the integrated structure of fins and pipes and their spiral strip distribution, the pressure bearing capacity of integral spiral finned steel pipes is more than three times that of seamless steel pipes with the same wall thickness and inner diameter.

5. Wear resistance has solved the problem of severe wear on the convection surface of coal-fired boilers due to high wind speed and high ash concentration. (Especially for circulating fluidized bed boilers)

6. The fins and tubes are integrated into a structure, completely eliminating the contact thermal resistance that other forms of finned steel pipes cannot overcome when the fins and tubes are two body structures. The longitudinal profile of the fins is trapezoidal, which greatly improves the heat transfer efficiency of the fins.

7. The integral spiral fin expansion surface heat transfer is adopted. Under the same working conditions, the heat transfer coefficient of the tube bundle is 3.5-5.5 times that of seamless steel pipes with the same wall thickness and inner diameter, and twice that of welded spiral fin steel pipes of the same specification.