Sealing structure for through-wall pipe of lower protection plate of combined cycle horizontal waste heat boiler

Abstract

The utility model relates to the technical field of horizontal waste heat boiler through-wall pipes, in particular to a combined cycle horizontal waste heat boiler lower protection plate through-wall pipe sealing structure which can prevent a protection plate at a through-wall pipe from being overheated when a waste heat boiler operates, prolong the service life of the sealing structure and improve the sealing performance. The through-wall pipe is sleeved with a sleeve, the bottom of the sleeve is welded to an embedded plate on the lower portion of the through-wall pipe, an annular plate clamping sleeve is welded to the outer side of the bottom protection plate, and the embedded plate is connected with the annular plate clamping sleeve through a non-metal expansion joint. An outer side sealing circular ring plate which is not welded and is clamped into the circular ring plate clamping sleeve and an inner side first sealing circular ring plate which is supported on the inner side of the bottom protection plate are arranged outside the sleeve in a sleeving manner, and heat preservation cotton is arranged between the outer side sealing circular ring plate and the first inner side sealing circular ring plate and above the inner side first sealing circular ring plate; an upper sealing structure is arranged above and around the heat preservation cotton on the first sealing circular ring plate on the inner side, and the through-wall pipe penetrates through the upper sealing structure.

Description

Technical Field

[0001] The utility model relates to the technical field of horizontal waste heat boiler wall-penetrating pipes, in particular to a sealing structure for a lower guard plate wall-penetrating pipe of a combined cycle horizontal waste heat boiler. Background Art

[0002] Gas-steam combined cycle is the mainstream power generation technology in developed countries in the world. It has the advantages of high overall efficiency and low pollution emissions. The waste heat boiler absorbs the exhaust heat of the gas turbine and produces steam to enter the steam turbine. It is an important equipment in the combined cycle power plant. The flue gas side of the waste heat boiler is the exhaust of the gas turbine. With the development of gas turbines, the exhaust temperature of H-class gas turbines has exceeded 650℃, and the highest has exceeded 700℃. The flue gas side of the waste heat boiler is a positive pressure condition. The lower through-wall pipe of the horizontal waste heat boiler has a large vertical and horizontal expansion. In actual operation, the protective plate at the through-wall pipe often overheats, and even the metal expansion joint used for sealing is damaged. Frequent maintenance and replacement are required, and the service life is short. Summary of the invention

[0003] In order to solve the above technical problems, the utility model provides a sealing structure for the lower guard plate through-wall pipe of a combined cycle horizontal waste heat boiler, which can prevent the guard plate at the through-wall pipe from overheating when the waste heat boiler is running, thereby extending the service life of the sealing structure.

[0004] The technical solution is as follows: a sealing structure for a lower guard plate through-wall pipe of a combined cycle horizontal waste heat boiler, comprising a through-wall pipe passing through a bottom guard plate, characterized in that a sleeve is provided on the outside of the through-wall pipe and the bottom of the sleeve is welded to the embedded plate at the bottom of the through-wall pipe, a circular plate sleeve is welded to the outside of the bottom guard plate, the embedded plate and the circular plate sleeve are connected by a non-metallic expansion joint, an outer sealing circular plate that is not welded and is inserted into the circular plate sleeve, and an inner first sealing circular plate supported on the inner side of the bottom guard plate are provided on the outside of the sleeve, thermal insulation cotton is arranged between the outer sealing circular plate and the inner first sealing circular plate and above the inner first sealing circular plate, an upper sealing structure is arranged above and around the thermal insulation cotton on the inner first sealing circular plate, and the through-wall pipe passes through the upper sealing structure.

[0005] It is further characterized in that the upper sealing structure comprises an inner cylinder of the guard plate welded to the inner side of the bottom guard plate, an upper annular clamping plate and a lower annular clamping plate arranged at intervals are welded at the upper opening of the inner cylinder of the guard plate, an inner second sealing annular plate is clamped between the upper annular clamping plate and the lower annular clamping plate, and the inner second sealing annular plate is not welded to the through-wall pipe;

[0006] An annular reinforcing rib plate is welded to the outer wall of the inner cylinder of the guard plate.

[0007] After adopting the utility model, the sealing circular ring plate on the inner side and the sealing circular ring plate on the outer side of the guard plate are utilized, and the thermal insulation cotton is filled in the middle. The high-temperature flue gas is completely isolated from the thermal insulation inner side of the guard plate by utilizing the structure of multiple baffles and thermal insulation cotton, thereby preventing the guard plate at the wall-penetrating pipe from overheating when the waste heat boiler is running. At the same time, this structure adopts a non-metallic expansion joint as the outermost sealing device. Compared with traditional metal expansion joints, non-metallic expansion joints have no metal fatigue, have a longer service life, and are more convenient to replace. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of the structure of the utility model;

[0009] Figure 2 for Figure 1 The enlarged schematic diagram at I in the middle;

[0010] Figure 3 for Figure 1 The enlarged schematic diagram of the middle II;

[0011] Figure 4 for Figure 1 AA diagram in the middle (bottom guard plate not shown);

[0012] Figure 5 for Figure 1 Schematic diagram of the center BB (bottom guard plate not shown). DETAILED DESCRIPTION

[0013] See Figures 1 to 4 The invention discloses a sealing structure for a wall-penetrating pipe of a lower guard plate of a combined cycle horizontal waste heat boiler, which comprises a wall-penetrating pipe 2 passing through a bottom guard plate 1, a sleeve 3 is provided on the outer surface of the wall-penetrating pipe 2, and the bottom of the sleeve 3 is welded to a pre-buried plate 4 at the bottom of the wall-penetrating pipe 1, a circular plate sleeve 5 is welded to the outer side of the bottom guard plate 1, the pre-buried plate 4 and the circular plate sleeve 5 are connected by a non-metallic expansion joint 6, an outer sealing circular plate 7 which is not welded and is inserted into the circular plate sleeve 5, and an inner first sealing circular plate 8 which is supported on the inner side of the bottom guard plate 1 are provided on the outer surface of the sleeve 3, thermal insulation cotton 9 is arranged between the outer sealing circular plate 7 and the first inner sealing circular plate 8, and above the inner first sealing circular plate 8, an upper sealing structure is arranged above and around the thermal insulation cotton 9 on the first inner sealing circular plate 8, and the wall-penetrating pipe 1 passes through the upper sealing structure.

[0014] The upper sealing structure includes an inner cylinder 10 of the guard plate welded to the inner side of the bottom guard plate 1, and an upper circular clamp plate 11 and a lower circular clamp plate 12 arranged at intervals are welded at the upper opening of the inner cylinder 10 of the guard plate. An inner second sealing circular ring plate 13 is clamped between the upper circular clamp plate 11 and the lower circular clamp plate 12, and the inner second sealing circular ring plate 13 is not welded to the wall-penetrating pipe 2; an annular reinforcing rib 14 is welded to the outer wall of the inner cylinder 10 of the guard plate, which can enhance the strength of the inner cylinder 10 of the guard plate, and is also welded to the bottom guard plate 1.

[0015] The outer sealing annular plate 7, the inner first sealing annular plate 8 and the inner second sealing annular plate 13 will not affect the vertical upward and downward expansion of the wall-penetrating pipe 1. The outer sealing annular plate 7 can not only seal the smoke, but also support the thermal insulation cotton 9 between the outer sealing annular plate 7 and the first inner sealing annular plate 8.

[0016] During assembly, first put the sleeve 3 on the wall-penetrating pipe 1 and weld it with the embedded plate 4. The annular plate sleeve 5 and the outer sealing annular plate 7 are pre-installed, and then the wall-penetrating pipe 1 together with the sleeve 3 pass through the outer sealing annular plate 7, and then install the first layer of thermal insulation cotton first, and cover the inner first sealing annular plate 7, and then weld and fix the internal cylinder 10 of the guard plate, and start to fill the second layer of thermal insulation cotton. This time the thermal insulation cotton should be filled as tightly as possible, and then install the lower annular clamp plate 12, the inner second sealing annular plate 13, and the upper annular clamp plate 11 in sequence. The upper annular clamp plate 11 and the lower annular clamp plate 12 are both welded and fixed to the internal cylinder 10 of the guard plate, which serves as the second seal here and has the functions of both sealing plate and packing seal. Finally, install the non-metallic expansion joint on the outermost side of the guard plate. Through the above wall-penetrating pipe and multiple sealing measures, it is ensured that the high-temperature flue gas will not contact the skin of the non-metallic expansion joint, which greatly extends the life and service life of the skin.

Claims

1. A sealing structure for a through-wall pipe at the bottom guard plate of a combined cycle horizontal waste heat boiler, comprising a through-wall pipe passing through the bottom guard plate, characterized in that: The wall-penetrating tube is sheathed with a sleeve and the bottom of the sleeve is welded to the embedded plate at the bottom of the wall-penetrating tube, a circular plate sleeve is welded to the outer side of the bottom guard plate, the embedded plate and the circular plate sleeve are connected by a non-metallic expansion joint, the sleeve is sheathed with an outer sealing circular plate that is not welded and is inserted into the circular plate sleeve, and an inner first sealing circular plate supported on the inner side of the bottom guard plate, thermal insulation cotton is arranged between the outer sealing circular plate and the inner first sealing circular plate and above the inner first sealing circular plate, an upper sealing structure is arranged above and around the thermal insulation cotton on the inner first sealing circular plate, and the wall-penetrating tube passes through the upper sealing structure.

2. The sealing structure of the lower guard plate through-wall pipe of a combined cycle horizontal waste heat boiler according to claim 1 is characterized in that: The upper sealing structure includes an inner cylinder of the guard plate welded to the inner side of the bottom guard plate, and an upper circular clamp plate and a lower circular clamp plate arranged at intervals are welded at the upper opening of the inner cylinder of the guard plate. An inner second sealing circular ring plate is clamped between the upper circular clamp plate and the lower circular clamp plate, and the inner second sealing circular ring plate is not welded to the wall-penetrating pipe.

3. The sealing structure of the lower guard plate through-wall pipe of a combined cycle horizontal waste heat boiler according to claim 2 is characterized in that: An annular reinforcing rib plate is welded to the outer wall of the inner cylinder of the guard plate.

Images