Flexible sealing device for tube bundle penetrating part of flue heating surface of waste heat boiler
By introducing expansion joints, limit folding plates and movable top sealing plates into the waste heat boiler flue sealing device, the problem of non-flexibility of the expansion of the tube bundle caused by welding fixation is solved, and the effect of coexistence of sealing and flexibility is achieved, and cracking and leakage is avoided.
Patent Information
- Application Number
- CN202421931960.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-09
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2034-08-09
AI Technical Summary
The existing waste heat boiler flue sealing method is welded and fixed, resulting in the lack of flexibility in the heating surface tube bundle when expanding at high temperature, which is prone to cracking and leakage.
A flexible sealing device is designed, including a horizontally arranged water-cooled pipe, a side sealing plate, a contraction joint, a limit folding plate and a movable top sealing plate. Through the combination of these components, a certain expansion allowance is achieved while sealing, and high-temperature expansion deformation is absorbed.
When ensuring the sealing of the flue, the device provides sufficient flexibility of the heating surface tube bundle and the container, avoiding cracking and leakage caused by high temperature expansion, and is especially suitable for large-span waste heat boilers.
Smart Images
Figure CN222978153U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a waste heat boiler, in particular to a flexible sealing device for the part where the heat exchange surface tube bundle of the waste heat boiler flue passes through; while sealing the flue, it can ensure that the heat exchange surface tube bundle and the header connected thereto still have good flexibility. Background Technique
[0002] In the flue of the waste heat boiler, the sealing cover at the place where the heat exchange surface tube bundle passes through the boiler water wall usually adopts a completely welded way; although this sealing method has good sealing performance, it also has the problem of reducing the flexibility of the pipeline. Since the heat exchange surface tube bundle usually has a large span, it will produce large expansion and deformation in both the horizontal and vertical directions after being heated; while the sealing cover welded to the tube bundle has poor stretchability due to being completely welded, and in the actual application process, it is easy to occur that the tube bundle and the header connected thereto cannot absorb the expansion deformation caused by high temperature through their own deformation, resulting in cracking and leakage at the connection between the tube bundle and the header and the welding place between the tube bundle and the sealing cover. Content of the Utility Model
[0003] The purpose of the utility model is to overcome the problems existing in the above background technique, and provide a flexible sealing device for the part where the heat exchange surface tube bundle of the waste heat boiler flue passes through. This device should have a certain expansion margin to ensure flue sealing and avoid cracking and leakage.
[0004] In order to achieve the above purpose, the utility model adopts the following technical scheme:
[0005] A flexible sealing device for the part where the heat exchange surface tube bundle of the waste heat boiler flue passes through, including several water-cooled tubes horizontally arranged in the water wall at the top of the flue, several side sealing plates and a top sealing plate fixed on the upper surfaces of the several water-cooled tubes, heat insulation materials filled between the water wall at the top of the flue and the sealing plates, and several heat exchange surface tube bundles vertically arranged and sequentially inserted into the inner cavity of the flue along the width direction of the horizontal flue;
[0006] It is characterized in that: the sealing device further includes an expansion joint horizontally fixed on the several side sealing plates, several limiting folding plates symmetrically fixed on the upper surface of the expansion joint on four sides and keeping a gap with the expansion joint, and the top sealing plate movably inserted into the gap; the top ends of the several heat exchange surface tube bundles sequentially pass through the water wall at the top of the flue, the expansion joint and the top sealing plate and then communicate with the external heat exchange surface tube bundle header, and the heat pipe sleeve fixed to the outer wall of the heat pipe is welded and fixed to the top sealing plate.
[0007] The cross-section of the side sealing plate is in a right-angle structure, and its vertical side is directly welded to the water wall at the top of the flue; the horizontal sides of the four side sealing plates are arranged in pairs facing each other.
[0008] The cross-section of the limiting folding plate is a right-angle structure; its vertical sides are respectively welded to the upper surface of the expansion joint, while the horizontal sides of the four limiting folding plates are arranged facing each other in pairs, and the lower surface of the horizontal sides is kept at a gap from the upper surface of the expansion joint; so that the top sealing plate located in this gap can move between the limiting folding plates and absorb part of the thermal expansion in the horizontal direction.
[0009] The expansion joint is horizontally arranged on the horizontal sides of the four side sealing plates to partially absorb the vertical thermal expansion generated by the heated tube due to high temperature.
[0010] The heat-insulating material completely fills the gap between several water-cooled tubes and the top sealing plate.
[0011] The top sealing plate is formed by splicing multiple sealing plates laid along the width direction of the heated tube. The length of the sealing plate is 1 - 1.5 meters; the width is determined according to the distance between two adjacent limiting folding plates welded to the upper surface of the expansion joint.
[0012] A gap required for thermal expansion is maintained between two adjacent sealing plates, and the gap is covered by a sealing steel plate. The two side edges of the sealing steel plate are respectively welded to two limiting folding plates.
[0013] The heated tube sleeve is sleeved outside the heated tube, and the axis of the heated tube sleeve is perpendicular to the plate surface of the top sealing plate.
[0014] The top sealing plate and the horizontal sides of the limiting folding plate have an activity gap of 0.8 - 1.2 mm.
[0015] The beneficial effects of the present utility model are: compared with the prior art, by arranging an expansion joint and limiting folding plates at the top of the sealing cover, the present utility model enables the sealing cover to have a certain expansion margin in both the horizontal and vertical directions while achieving the sealing effect, so that the heating surface tube bundle has sufficient flexibility to absorb the thermal expansion generated by high temperature, and avoids cracking at the welded joints of the tube bundle with the header and the sealing cover. The present utility model is particularly suitable for the sealing at the penetration of the heating surface tube bundle of a large-span waste heat boiler. Description of the Drawings
[0016] Figure 1 It is a top view structural schematic diagram of an embodiment of the present utility model.
[0017] Figure 2 It is a front view structural schematic diagram of an embodiment of the present utility model.
[0018] Figure 3 It is Figure 2 An enlarged structural schematic diagram of the top sealing assembly in
[0019] Figure 4 An enlarged structural schematic diagram of the top sealing plate in the top view direction (relative toFigure 1 , rotated 90 degrees).
[0020] Figure 5 is Figure 4 the schematic cross-sectional structure view in the A-A direction (after the A-A direction cross-section and then rotated 90 degrees) in
[0021] Markings in the figure: 1 - water-cooled pipe; 2 - heat-absorbing surface tube bundle; 3 - side sealing plate; 4 - expansion joint; 5 - limit folding plate; 6 - top sealing plate; 7 - thermal insulation material; 8 - sealing steel plate. Specific implementation
[0022] The following further illustrates the present utility model in conjunction with the embodiments shown in the accompanying drawings.
[0023] As Figure 1 , Figure 2 shown ( Figure 1 only shows a partial view of the water-cooled wall at the top of the flue), the water-cooled wall at the top of the flue includes a plurality of water-cooled pipes 1 arranged horizontally and parallel to each other. A rectangular sealing cover composed of four side sealing plates 3 and a top sealing plate 6 is welded and fixed on the upper surface of these water-cooled pipes. Thermal insulation material 7 (usually aluminosilicate thermal insulation material) is filled inside the sealing cover; a plurality of heat-absorbing surface tube bundles 2 arranged vertically are inserted into the flue cavity and arranged in sequence along the width direction of the flue (i.e., Figure 1 the up and down direction of
[0024] In the existing sealing structure at the top of the flue of the waste heat boiler, since the sealing cover is welded and fixed to both the heat-absorbing surface tube bundle and the water-cooled wall, it cannot absorb the expansion deformation caused by high temperature, resulting in cracking and leakage prone to occur at the connection between the heat-absorbing surface tube bundle and the header and at the welded joint between the tube bundle and the sealing cover.
[0025] The improvement made by the present utility model is:
[0026] The provided flexible sealing device for the heat transfer surface tube bundle passing through part of the waste heat boiler flue also includes expansion joints horizontally fixed (preferably by welding) on the four side sealing plates around, limit folding plates symmetrically fixed (preferably by welding) on the upper surface of the expansion joints and keeping a gap with the expansion joints, and the top sealing plate movably inserted into the gap (the top sealing plate originally fixed to the side sealing plate is now changed to a sliding installation). The top ends of several pairs of vertically arranged heating tubes sequentially pass upward through the water-cooled wall at the top of the flue, the expansion joint and the top sealing plate and then communicate with the external steam pipeline. The heating tube sleeves sleeved and fixed on the outer wall of the heating tubes are welded and fixed to the top sealing plate; the heat insulation material completely fills the gap between the water-cooled wall at the top of the flue and the sealing cover.
[0027] As Figure 2 , Figure 3 shown, the side sealing plate 3 with a right-angled cross-section is horizontally placed (the length direction of the side sealing plate is perpendicular to Figure 2 the paper surface), and its vertical side is directly welded to the water-cooled wall at the top of the flue; the horizontal sides of the four side sealing plates are arranged in pairs facing each other. The installation structure of the side sealing plate is the same as that before improvement and does not need to be changed.
[0028] The lengths of the four side sealing plates are determined by the width of the water-cooled wall at the top of the flue and the number and span of the heat transfer surface tube bundles.
[0029] As Figure 2 , Figure 3 shown, the expansion joints 4 are horizontally arranged on the horizontal sides of the four side sealing plates and welded and fixed to the four side sealing plates; the expansion joints have elasticity and can absorb the vertical thermal expansion of the heat transfer surface tube bundle caused by high temperature to a certain extent. The four limit folding plates 5 with a right-angled cross-section are separated from each other in parallel by a certain distance, and their vertical sides are respectively welded to the upper surface of the expansion joints (the four limit folding plates also enclose a rectangle); the horizontal sides of the four limit folding plates are arranged in pairs facing each other and the lower surfaces of the horizontal sides keep a gap with the upper surface of the expansion joints. The horizontally arranged top sealing plate 6 is inserted into the gap. Several heating surface tube bundles 2 forming the heating surface are vertically arranged and pass upward through the water-cooled wall at the top of the flue, the expansion joint and the top sealing plate, and then the outer wall of the heating tube sleeve is welded and fixed to the top sealing plate. Since the top sealing plate 6 is not welded to the expansion joint 4 and the limit folding plate 5, the top sealing plate 6 can freely slide within the range limited by the limit folding plate 5 (the top sealing plate has a large degree of freedom of movement in the front, back, left and right directions in the horizontal plane) to absorb the horizontal thermal expansion of the heat transfer surface tube bundle caused by high temperature (including the direction perpendicular to Figure 2 the paper surface direction and Figure 2 the left and right directions).
[0030] Furthermore, although the top sealing plate 6 inserted into the gap is not seal-welded to the expansion joint 4, since the width of the movable gap B between the final top sealing plate 6 and the horizontal side of the limit folding plate 4 is 0.8 - 1.2 mm, considering the bending structure here, the thermal expansion caused by high temperature during normal operation, and the filling of thermal insulation materials, the overall sealing performance of the device can be ensured.
[0031] As Figure 4 , Figure 5 shown, the top sealing plate 6 should be formed by splicing multiple sealing plates with a length of 1 to 1.5 meters according to the pitch of the heating surface tube bundle (the multiple sealing plates are spliced in sequence along the width direction of the flue), and there is no welding between the sealing plates and a certain gap is left. While considering the ease of transportation and construction, the sealing device has more degrees of freedom to absorb the thermal expansion of the heating surface tube bundle in the left and right directions; both side edges of the sealing steel plate 8 are welded to two limit folding plates 5 respectively for sealing the connection between the top sealing plates 6.
Claims
1. A flexible sealing device for a heat receiving surface tube bundle passing through a flue of a waste heat boiler, comprising a plurality of water cooling tubes (1) arranged horizontally in a water cooling wall at the top of the flue, a plurality of side sealing plates (3) and a top sealing plate (6) fixed on the upper surface of the plurality of water cooling tubes, a heat preservation material (7) filled between the water cooling wall at the top of the flue and the sealing plate, and a plurality of heat receiving surface tube bundles (2) arranged vertically and sequentially inserted into the inner cavity of the flue along the horizontal flue width direction; Features: The sealing device also includes an expansion joint (4) horizontally fixed on a plurality of side sealing plates, a plurality of limit folding plates (5) symmetrically fixed on four sides of the upper surface of the expansion joint and maintaining a gap with the expansion joint, and the top sealing plate (6) movably inserted in the gap; the top ends of the plurality of heating surface tube bundles pass through the flue top water-cooled wall, the expansion joint and the top sealing plate in sequence upwards and then connect to the external heating surface tube bundle header, and the heating tube sleeve fixed to the outer wall of the heating tube is welded and fixed to the top sealing plate.
2. The flexible sealing device for the exit of the heat recovery boiler flue heating surface tube bundle according to claim 1 is characterized in that: The cross section of the side sealing plate is a right-angle structure, and its vertical side surface is directly welded to the water-cooled wall at the top of the flue; the horizontal side surfaces of the four side sealing plates are arranged opposite to each other in pairs.
3. The flexible sealing device for the exit of the heat recovery boiler flue heating surface tube bundle according to claim 2 is characterized in that: The cross section of the limiting folding plate is a right-angle structure; its vertical side surfaces are respectively welded to the upper surface of the expansion joint, and the horizontal side surfaces of the four limiting folding plates are arranged opposite to each other in pairs and a gap is maintained between the lower surface of the horizontal side surface and the upper surface of the expansion joint; so that the top sealing plate located in the gap can move between the limiting folding plates to absorb part of the thermal expansion in the horizontal direction.
4. The flexible sealing device for the exit of the heat recovery boiler flue heating surface tube bundle according to claim 3 is characterized in that: The expansion and contraction joints are horizontally arranged on the horizontal sides of the four side sealing plates to partially absorb the thermal expansion of the heated pipes in the vertical direction due to the high temperature.
5. The flexible sealing device for the exit portion of the heat recovery boiler flue heating surface tube bundle according to claim 4 is characterized in that: The heat-insulating material completely fills the gaps between the plurality of water-cooling pipes and the sealing cover.
6. The flexible sealing device for the exit of the heat recovery boiler flue heating surface tube bundle according to claim 5 is characterized in that: The top sealing plate is formed by splicing multiple sealing plates laid along the width direction of the heated pipe. The length of the sealing plate is 1-1.5 meters; the width is determined by the distance between two adjacent limit folding plates welded on the upper surface of the expansion and contraction joint.
7. The flexible sealing device for the exit of the heat recovery boiler flue heating surface tube bundle according to claim 6 is characterized in that: A gap required for thermal expansion is maintained between two adjacent sealing plates, and a sealing steel plate (8) seals and covers the gap. The edges on both sides of the sealing steel plate are respectively welded to two limit folding plates.
8. The flexible sealing device for the exit of the heat recovery boiler flue heating surface tube bundle according to claim 7 is characterized in that: The heated pipe sleeve is sleeved on the outside of the heated pipe, and the axis of the heated pipe sleeve is perpendicular to the surface of the top sealing plate.
9. The flexible sealing device for the exit portion of the heat recovery boiler flue heating surface tube bundle according to claim 8 is characterized in that: The top sealing plate and the horizontal side surface of the limiting folding plate have a movable gap (B) of 0.8-1.2 mm.