Welding joint structure of smoke tube and tube plate

Abstract

The utility model discloses a welding joint structure of a smoke tube and a tube plate, which comprises a tube plate hole arranged on the tube plate, one end of the smoke tube extends into one end of the tube plate hole close to a shell pass side, and a section of smoke tube groove is arranged on the outer wall of the end part of the smoke tube in the tube plate hole. The wall thickness of the end part of the smoke tube is gradually reduced from the shell pass side to the inner direction of the tube plate hole through the smoke tube groove; a circle of protrusion is arranged on the inner wall of the end area, located at one end of the shell pass side, in the tube plate hole, the thickness of the protrusion protruding out of the inner wall of the tube plate hole is gradually increased in the direction from the tube plate hole to the shell pass side, and the protrusion forms a tube plate hole groove. And the smoke tube groove and the tube plate hole groove are fixedly and hermetically connected through total cross-section penetration welding. The utility model has the advantages that: 1, the structure is simple, and the welding seam between the smoke tube and the tube plate hole is close to one end of the shell pass side, so that the welding seam can be fully cooled, the influence of the temperature difference between the tube plate and the smoke tube on the welding seam can be effectively reduced, and the generation of fatigue cracks can be effectively avoided;

Description

TECHNICAL FIELD

[0001] The utility model relates to a waste heat recovery equipment technical field, concretely relates to a smoke pipe boiler. BACKGROUND

[0002] The smoke pipe boiler usually includes: a shell side cylinder, a flue gas inlet chamber and a flue gas outlet chamber are arranged at both ends of the shell side cylinder, a tube sheet is arranged between the flue gas inlet chamber and the shell side cylinder and between the flue gas outlet chamber and the shell side cylinder respectively, a plurality of smoke pipes are arranged in the shell side cylinder, both ends of the smoke pipe are welded and fixedly and sealingly connected with tube sheet holes on the tube sheet, so as to be communicated with the flue gas inlet chamber and the flue gas outlet chamber respectively.

[0003] The welding joint structure of the conventional smoke pipe and the tube sheet includes: one end of the smoke pipe extends out of the tube sheet hole and away from the shell side, that is, the port of the smoke pipe is located in the flue gas inlet chamber or in the flue gas outlet chamber, and the outer wall of the port of the smoke pipe and the inner wall of the tube sheet hole are fixedly and sealingly connected by an angle weld.

[0004] During long-term operation of the boiler, the weld between the smoke pipe and the tube sheet is prone to corrosion and cracking, and the weld root often has phenomena such as incomplete fusion and incomplete penetration, especially the weld between the tube sheet on the side of the flue gas inlet chamber and the heat exchange pipe is located at the position of the flue gas inlet chamber, the temperature of this area is high, the weld cannot be fully cooled, and the weld works in a high-temperature environment for a long time. INVENTION CONTENTS

[0005] The utility model needs to solve the technical problem of providing a welding joint structure of a smoke pipe and a tube sheet, which is simple in structure, firm and reliable in connection, and can effectively avoid the generation of fatigue cracks in the weld between the smoke pipe and the tube sheet.

[0006] To solve the above problems, the utility model adopts the technical scheme of a welding joint structure of a smoke pipe and a tube sheet, which includes: a tube sheet hole opened in a tube sheet, one end of a smoke pipe extends into the tube sheet hole and is close to the shell side, a smoke pipe bevel is arranged on the outer wall of the end of the smoke pipe in the tube sheet hole, the smoke pipe bevel makes the wall thickness of the end of the smoke pipe gradually decrease from the shell side to the direction of the tube sheet hole, a protrusion is arranged on the inner wall of the end region of the tube sheet hole on the shell side, the thickness of the protrusion protruding from the inner wall of the tube sheet hole gradually increases in the direction of the shell side along the tube sheet hole, the protrusion forms a tube sheet hole bevel, and the smoke pipe bevel and the tube sheet hole bevel are fixedly and sealingly connected by full-section welding.

[0007] Further, the foregoing welding joint structure of a smoke tube and a tube plate, wherein the tube plate hole is provided with a tube plate hole blunt edge at the end of the end on the shell side, the tube plate hole blunt edge is connected with the tube plate hole bevel; the tube plate hole bevel on the shell side is flush with the tube plate hole bevel on the shell side; the gap between the tube plate hole blunt edge and the outer wall of the smoke tube is 1-1.5mm; the gap between the smoke tube bevel and the tube plate hole bevel and the gap between the tube plate hole blunt edge and the outer wall of the smoke tube are full cross welding.

[0008] Further, the foregoing welding joint structure of a smoke tube and a tube plate, wherein the length of the blunt edge is 0.5mm.

[0009] Further, the foregoing welding joint structure of a smoke tube and a tube plate, wherein the angle of the smoke tube bevel is 30-45°.

[0010] Further, the foregoing welding joint structure of a smoke tube and a tube plate, wherein the angle of the tube plate hole bevel is 30-45°.

[0011] Further, the foregoing welding joint structure of a smoke tube and a tube plate, wherein the end face of the weld between the smoke tube bevel and the tube plate hole bevel extends from the inner end of the smoke tube bevel to the inner wall of the tube plate hole and is parallel to the tube plate hole bevel.

[0012] The advantages of the present application are: 1. The structure is simple, one end of the smoke tube is inserted into the tube plate hole on the shell side, and is welded and fixed at the position, which makes the weld on the shell side, so that the weld can exchange heat with the material in the shell, thereby being fully cooled, and further effectively reducing the influence of the temperature difference between the tube plate and the smoke tube on the weld, effectively avoiding the generation of fatigue cracks. 2. One end of the smoke tube is inserted into the tube plate hole on the shell side, and the full cross welding between the smoke tube bevel and the tube plate hole bevel, so that the formed weld has high reliability, firm connection, can further avoid the generation of fatigue cracks, and is convenient for endoscopic examination of the weld root, and ensures the weld quality. 3. The tube plate hole blunt edge is provided, and the gap between the tube plate hole blunt edge and the outer wall of the smoke tube is left, which is convenient for ensuring full cross welding, thereby ensuring the weld quality. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a structural schematic view of the welding joint structure of a smoke tube and a tube plate.

[0014] Figure 2 is Figure 1 is an enlarged structural schematic view of part A in the figure. DETAILED DESCRIPTION

[0015] The present application will be further described in detail below in combination with the drawings and preferred embodiments.

[0016] As Figure 1 , Figure 2 shown, a kind of welding joint structure of smoke pipe and tube plate, including: the tube plate hole 2 being opened in tube plate 1, the end of smoke pipe 3 is inserted into the end of tube plate hole 2 near shell side 4, the end of smoke pipe 3 in tube plate hole 2 is provided with a section of smoke pipe bevel 31 on outer wall.The angle θ of smoke pipe bevel 31 in the embodiment is 30 °-45 °.Smoke pipe bevel 31 makes the wall thickness of the end of smoke pipe 3 gradually smaller from shell side to the direction inside tube plate hole 2.

[0017] The end of the end region in tube plate hole 2 is located in shell side 4 inner wall and is provided with a circle of protrusion 21, the thickness of protrusion protruding from the inner wall of tube plate hole 2 gradually increases along tube plate hole 2 to shell side 4 direction, and the protrusion forms tube plate hole bevel 21.The angle α of tube plate hole bevel 21 is 30 °-45 °.Smoke pipe bevel 31 and tube plate hole bevel 21 are fixedly connected by full cross-section welding penetration.

[0018] The end of the end of the inner wall of tube plate hole 2 is located in shell side 4 and is provided with tube plate hole land 22, and the land length L1 of tube plate hole land 22 is 0.5 mm.The tube plate hole land 22 is connected with tube plate hole bevel 21.The end of smoke pipe bevel 31 near shell side 4 is flush with the end of tube plate hole bevel 21 near shell side 4.There is a gap L2 between tube plate hole land 22 and the outer wall of smoke pipe 3, and the gap L2 is 1-1.5 mm.The gap between smoke pipe bevel 31 and tube plate hole bevel 21 and between tube plate hole land 22 and the outer wall of smoke pipe 3 is welded by full cross-section penetration.The end surface 51 of weld 5 between smoke pipe bevel 31 and tube plate hole bevel 21 extends from the inner end of smoke pipe bevel 31 to the inner wall of tube plate hole 2 and is parallel to tube plate hole bevel 21.

[0019] The welding joint structure of smoke pipe and tube plate described in the application has the following advantages: first, the structure is simple, one end of smoke pipe 3 is inserted into tube plate hole 2 near shell side 4, and welding is carried out at this position, which makes the end of weld 5 near shell side 4, so that weld 5 can exchange heat with the material in shell side, thereby being fully cooled, which can effectively reduce the influence of the temperature difference between tube plate 1 and smoke pipe on weld 5, effectively avoid the generation of fatigue cracks, and ensure the long-term stable operation of the boiler.Second, one end of smoke pipe 3 is inserted into tube plate hole 2 near shell side 4, and full cross-section welding penetration is carried out between smoke pipe bevel 31 and tube plate hole bevel 21, so that the reliability of the formed weld is high, the connection is firm, the generation of fatigue cracks can be further avoided, and the situation of weld root can be easily checked by endoscope, thereby ensuring the quality of weld.Third, tube plate hole land 22 is provided, and there is a gap between tube plate hole land 22 and the outer wall of smoke pipe 3, which can ensure full cross-section welding penetration and thereby ensure the quality of weld.

Claims

1. A welded joint structure between a smoke pipe and a tube sheet, comprising: The tube sheet hole formed on the tube sheet is characterized in that: one end of the flue extends into the tube sheet hole near the shell side, and a flue bevel is provided on the outer wall of the end of the flue located in the tube sheet hole, the flue bevel causing the wall thickness of the end of the flue to gradually decrease from the shell side towards the tube sheet hole; a ring of protrusions is provided on the inner wall of the end area of ​​the tube sheet hole located on the shell side, the thickness of the protrusions protruding from the inner wall of the tube sheet hole gradually increases along the tube sheet hole towards the shell side, the protrusions forming the tube sheet hole bevel; the flue bevel and the tube sheet hole bevel are fully welded through and sealed together.

2. The welded joint structure of a smoke pipe and a tube sheet according to claim 1, characterized in that: The tube sheet hole is provided with a blunt edge at one end on the shell side, and the blunt edge of the tube sheet hole is connected to the bevel of the tube sheet hole; the end of the flue bevel near the shell side is flush with the end of the tube sheet hole bevel near the shell side; a gap of 1 to 1.5 mm is left between the blunt edge of the tube sheet hole and the outer wall of the flue; the gap between the flue bevel and the tube sheet hole bevel, and between the blunt edge of the tube sheet hole and the outer wall of the flue, are fully welded through the cross section.

3. The welded joint structure of a smoke pipe and a tube sheet according to claim 1, characterized in that: The blunt edge length is 0.5mm.

4. The welded joint structure of a smoke pipe and a tube sheet according to claim 1, 2, or 3, characterized in that: The angle of the flue bevel is 30° to 45°.

5. The welded joint structure of a smoke pipe and a tube sheet according to claim 1, 2, or 3, characterized in that: The bevel angle of the tube sheet hole is 30° to 45°.

6. The welded joint structure of a smoke pipe and a tube sheet according to claim 1, characterized in that: The end face of the weld between the flue bevel and the tube sheet hole bevel extends from the inner end of the flue bevel toward the inner wall of the tube sheet hole and is parallel to the tube sheet hole bevel.

Images