CN112146077A

CN112146077A - High-efficiency internal tooth high-pressure boiler tube

Info

Publication number: CN112146077A
Application number: CN202011020380.7A
Authority: CN
Inventors: 胡省宪; 徐勇
Original assignee: SHANGHAI YUYANG SPECIAL METAL MATERIALS CO LTD
Current assignee: SHANGHAI YUYANG SPECIAL METAL MATERIALS CO LTD
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2020-12-29

Abstract

The embodiment of the invention discloses a high-efficiency internal tooth high-pressure boiler pipe, which comprises an internal tooth pipe and a boiler pipe, wherein a layer of intermediate metal is attached to the outer surface of the internal tooth pipe, the outer diameter of the internal tooth pipe is smaller than the inner diameter of the boiler pipe, the internal tooth pipe is fixed in the boiler pipe, and the internal tooth pipe and two ends of the boiler pipe are welded.

Description

High-efficiency internal tooth high-pressure boiler tube

Technical Field

The invention relates to the field of heat exchange tube manufacturing, in particular to a high-efficiency internal tooth high-pressure boiler tube.

Background

The existing power station boiler tubes are all thick-wall carbon steel tubes or seamless steel tubes, and smooth or sparse shallow threads are arranged in the tubes. The heat exchange efficiency is low.

At present, heat exchange pipes for strengthening the inner surface are not basically used for strengthening heat exchange of the inner surface, and part of the heat exchange pipes are used for strengthening the inner surface, but are not suitable for high-pressure boilers, generally small-caliber thin-walled pipes are used, so that the pressure resistance is insufficient, and the flow is insufficient.

Disclosure of Invention

In view of this, the embodiment of the invention provides an efficient internal-tooth high-pressure boiler tube, which is resistant to high pressure and has excellent heat transfer characteristics.

The embodiment of the invention discloses a high-efficiency internal tooth high-pressure boiler pipe which comprises an internal tooth pipe and a boiler pipe, wherein a layer of intermediate metal is attached to the outer surface of the internal tooth pipe, the outer diameter of the internal tooth pipe is smaller than the inner diameter of the boiler pipe, the internal tooth pipe is fixed in the boiler pipe, and the two ends of the internal tooth pipe and the two ends of the boiler pipe are welded.

Further, the melting point of the intermediate metal is 600 degrees.

Further, the outer diameter of the internal gear pipe is 0.5mm smaller than the inner diameter of the boiler pipe.

Further, the thickness of the plating layer of the intermediate metal is 2 times of the roughness of the inner wall of the boiler pipe, and the attaching method is hot dipping or electroplating.

Furthermore, before the boiler pipe is fixed with the inner toothed pipe, the inner surface of the boiler pipe is subjected to acid cleaning to remove an oxidation film, and the boiler pipe is dried by hot argon and then protected.

Further, after the inner gear pipe and the boiler pipe are inserted, one end is welded and sealed, the inner gear pipe and the boiler pipe are gradually expanded from a welding head to the other end, and an induction coil is used for heating the expanded joint to 800 ℃ to promote the fusion of two layers of metals; and after the expansion joint is finished, the joint of the other end is also welded to connect the inner layer metal and the outer layer metal.

The invention has the following advantages:

1. the high-pressure resistant heat exchanger has high pressure resistance and good boiling heat transfer effect;

2. the processing cost is low, and the cost performance is high;

3. the metal consumption of the boiler is reduced, and the overall size is reduced;

4. boiler tube explosion caused by overheating is eliminated.

Drawings

Fig. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a left side view of an embodiment of the present invention.

FIG. 3 is a cross-sectional view of an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in the figure, the embodiment of the invention discloses a high-efficiency internal tooth high-pressure boiler pipe which comprises an internal tooth pipe 1 and a boiler pipe 2, wherein a layer of intermediate metal 3 is attached to the outer surface of the internal tooth pipe, the outer diameter of the internal tooth pipe is smaller than the inner diameter of the boiler pipe, the internal tooth pipe is fixed in the boiler pipe, and the two ends of the internal tooth pipe and the two ends of the boiler pipe are welded.

In one embodiment of the present invention, the melting point of the intermediate metal is 600 degrees.

In one embodiment of the invention, the outside diameter of the internally toothed tube is 0.5mm smaller than the inside diameter of the boiler tubes.

In one embodiment of the invention, the thickness of the coating of the intermediate metal is 2 times of the roughness of the inner wall of the boiler tube, and the attaching method is hot dipping or electroplating.

In one embodiment of the invention, before the boiler tube is fixed with the inner toothed tube, the inner surface of the boiler tube is acid-washed to remove an oxidation film, and is dried by hot argon gas and then protected.

In one embodiment of the invention, after the inner gear pipe and the boiler pipe are inserted, one end is welded and sealed, the inner gear pipe and the boiler pipe are gradually expanded from a welding head to the other end, and an induction coil is used for heating the expanded joint to 800 ℃ to promote the fusion of two layers of metals; and after the expansion joint is finished, the joint of the other end is also welded to connect the inner layer metal and the outer layer metal.

The inner surface of the boiler pipe and the outer surface of the inner gear pipe are subjected to expansion joint compounding and high-temperature fusion to form a bimetal composite pipe with an efficient heat exchange inner surface;

has the advantages that:

1. the heat exchange efficiency of the boiler tube is improved, and the purposes of reducing material waste and equipment volume are achieved;

2. the overheating phenomenon of the boiler caused by film boiling is eliminated, and the possibility of tube explosion is reduced;

3. reduce the probability of scale formation and prolong the service life.

The embodiment of the invention discloses a method for manufacturing a high-efficiency heat exchange tube of a high-pressure boiler, which comprises the following steps:

oxidizing layer treatment, namely performing oxidizing layer removal treatment on the inner wall of the thick-wall seamless pipe, and filling nitrogen for protection after the treatment is finished;

adhering intermediate metal to the outer surface of the thin-wall inner gear pipe;

penetrating the thin-wall internal gear pipe into the thick-wall seamless pipe, and welding and fixing the thick-wall seamless pipe and the thin-wall internal gear pipe by argon arc welding at one end to form a composite pipe;

expanding the pipe, sealing two ends of the composite pipe, and inflating high pressure inside the composite pipe to expand the inner pipe outwards; it should be slightly over-inflated so that the outer tube is slightly inflated to the point where the yield point of the outer tube is not reached. Welding the other end after the expansion joint is finished; mechanical expansion of the tube must not be used to avoid damaging the tooth profile.

And (4) welding, heating the outer pipe by using an induction coil, and melting the middle layer metal.

In an embodiment of the present invention, in the oxide layer treatment step, descaling by acid washing or mechanical polishing is used. The inner surface of the steel pipe is free from oxidation, oil stain and impurities before the steel pipe is processed in the next step.

In one embodiment of the present invention, in the step of attaching the intermediate metal, the intermediate metal is selected according to an inner and outer layer welding method, and if the intermediate metal is brazing, a low melting point metal is selected, and if the intermediate metal is diffusion welding, a metal with good extensibility is selected.

In one embodiment of the present invention, in the fusion step, if diffusion welding is used, the tube expansion pressure is kept during fusion, and if brazing is used, welding is performed after pressure relief.

The embodiment of the invention can be used for producing various heat exchange tubes resistant to high temperature and high pressure.

The above description is only a preferred embodiment of the present invention, but other driving mechanisms including, but not limited to, motor driving and other driving sources are not intended to limit the present invention, and any modifications, equivalents and the like within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The high-efficiency internal tooth high-pressure boiler pipe is characterized by comprising an internal tooth pipe and a boiler pipe, wherein a layer of intermediate metal is attached to the outer surface of the internal tooth pipe, the outer diameter of the internal tooth pipe is smaller than the inner diameter of the boiler pipe, the internal tooth pipe is fixed in the boiler pipe, and the two ends of the internal tooth pipe and the two ends of the boiler pipe are welded.

2. A high efficiency internally toothed high pressure boiler tube according to claim 1, wherein the melting point of the intermediate metal is 600 degrees.

3. A high efficiency internally toothed high pressure boiler tube as set forth in claim 1, wherein the internally toothed tube outside diameter is 0.5mm smaller than the boiler tube inside diameter.

4. A high efficiency internally toothed high pressure boiler tube according to claim 3, wherein the intermediate metal is plated to a thickness of 2 times the roughness of the inner wall of the boiler tube by hot dip plating or electroplating.

5. A high efficiency internal tooth high pressure boiler tube as claimed in claim 1, wherein the boiler tube is acid-washed with an oxide film on its inner surface before being fixed to the internal tooth tube and protected after being dried with hot argon gas.

6. The high-efficiency internal-tooth high-pressure boiler pipe as claimed in claim 1, wherein after the internal-tooth pipe and the boiler pipe are inserted, one end is welded and sealed, the internal-tooth pipe and the boiler pipe are gradually expanded from the welding head to the other end, and an induction coil is used for heating the expansion joint to 800 degrees to promote the fusion of two layers of metals; and after the expansion joint is finished, the joint of the other end is also welded to connect the inner layer metal and the outer layer metal.