A steam-water separation structure in the steam drum of a circulating fluidized bed boiler

Abstract

This utility model discloses a steam-water separation structure in a circulating fluidized bed boiler drum, including a steam-water separator, an arc-shaped baffle assembly, and a baffle plate assembly. The steam-water separator is installed on the upper part of the drum, corresponding to the saturated steam pipe joint of the drum. The arc-shaped baffle plate assembly is installed on both sides of the inner wall of the drum at the welding positions of the riser pipe joints, forming a first-stage steam separation space together with the inner wall of the drum. The baffle plate assembly is installed on the upper outer side of the arc-shaped baffle plate assembly, forming a second-stage steam separation space together with the arc-shaped baffle plate assembly. The bottom of the first-stage steam separation space is connected to the water space inside the drum, and the upper part of the first-stage steam separation space is connected to the second-stage steam separation space. The bottom of the second-stage steam separation space is connected to the water space inside the drum, and the upper part of the second-stage steam separation space is connected to the steam space inside the drum. This utility model significantly improves the quality of boiler steam and enhances the safety and stability of boiler operation.

Description

Technical Field

[0001] This utility model relates to the field of circulating fluidized bed boiler technology, and in particular to a steam-water separation structure in the steam drum of a circulating fluidized bed boiler. Background Technology

[0002] The steam drum in a circulating fluidized bed boiler is a very important component of the boiler system. It is mainly used for steam-water separation and storage of a certain amount of water and steam. The steam drum is usually made of high-strength boiler steel plate, which can withstand high temperature and high pressure.

[0003] During boiler operation, when the salinity of steam and boiler water remains constant, as the boiler load gradually increases, the flow velocity of the steam-water mixture in the riser increases, leading to an increase in the kinetic energy of the steam-water mixture entering the steam drum. This results in a slight increase in the amount of water carried in the steam. Particularly when the boiler load exceeds the design value, the excessively rapid evaporation rate and the lag in the feedwater system's regulation response cause abnormal fluctuations in the steam drum water level, significantly increasing the amount of water carried in the steam. This, in turn, affects steam quality, reduces economic efficiency, and further impacts the safe and stable operation of the boiler. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model designs a steam-water separation structure in the steam drum of a circulating fluidized bed boiler.

[0005] The present invention adopts the following technical solution: A steam-water separation structure in a circulating fluidized bed boiler drum includes a steam-water separator installed on the upper part of the steam drum, the position of which corresponds to the saturated steam pipe joint in the horizontal direction of the steam drum; and also includes an arc-shaped baffle assembly and a baffle assembly. The arc-shaped baffle assembly is installed on the inner wall of both sides of the steam drum at the welding position of the corresponding riser pipe joint, and together with the inner wall of the steam drum, it forms the first-stage steam separation space. The baffle assembly is installed on the upper outer side of the arc-shaped baffle assembly. Together with the arc-shaped baffle assembly, it encloses the second-stage steam separation space. The bottom of the first-stage steam separation space is connected to the water space inside the steam drum, and the upper part of the first-stage steam separation space is connected to the second-stage steam separation space. The bottom of the second-stage steam separation space is connected to the water space inside the steam drum, and the upper part of the second-stage steam separation space is connected to the steam space inside the steam drum.

[0006] Preferably, the arc-shaped baffle assembly includes an arc-shaped baffle, fixed supports on the inner wall of the steam drum, two end plates, and an arc-shaped plate. The fixed supports include slotted angle steel, T-shaped support angles, steel plates, and a top plate. The arc-shaped baffle is welded and fixed to the slotted angle steel, T-shaped support angles, and steel plates. The front and rear sides of the arc-shaped baffle assembly are sealed by end plates. The arc-shaped plate is positioned below the top plate and fixed to the steel plate. A slotted angle steel is installed at 52.5° below the centerline of the steam drum. The slots on the slotted angle steel are approximately 550mm long, spaced approximately 1450mm apart, and face downwards. Steel plates are arranged at intervals of approximately 550mm along the length of the steam drum, 235mm above the centerline. A top plate is positioned above the steel plates, spaced approximately 110mm apart. The arc-shaped plate is 12mm thick, while the top plate, steel plate, end plates, arc-shaped baffles, and T-shaped support corners are 10mm thick and made of Q235B steel. The width of the arc-shaped baffles should be wide enough to allow passage through the manhole. After the arc-shaped baffle assembly is installed inside the steam drum, its open ends are sealed by end plates. The enclosed area formed by the two end plates must completely cover all riser pipe joints, ensuring that the length of the area is not less than two-thirds of the straight section length of the steam drum. This forces a change in the steam flow direction, achieving efficient steam-water separation. Both ends of the arc-shaped baffle assembly and the baffle assembly are sealed by the same end plate. The end plate not only reinforces the baffle assembly but also effectively prevents steam leakage.

[0007] Preferably, the arc-shaped baffle is concentric with the inner wall of the steam drum. The arc-shaped baffle is spaced at a certain distance from the inner wall of the steam drum, typically 110 mm, and has small holes with a diameter of Φ35 mm. The holes are spaced at a distance of 500 mm and are evenly distributed.

[0008] Preferably, T-shaped support angles are provided at equal intervals between the arc-shaped baffle and the inner wall of the steam drum. The T-shaped support angles are arranged three evenly at 17.5° intervals, pointing downwards along the center line of the steam drum's arc, with their welding positions corresponding to the small holes on the arc-shaped baffle.

[0009] Preferably, the baffle assembly includes a steam equalization orifice plate, a baffle plate, a straight plate, a rib plate, and an end plate. The front and rear sides of the baffle assembly are sealed by the end plates. The steam equalization orifice plate, the baffle plate, and the straight plate are welded sequentially. One end of the rib plate is welded to the baffle assembly, and the other end is welded to the arc-shaped baffle plate to form a stable support structure. The thickness of the aforementioned steam equalization orifice plate, baffle plate, and straight plate is generally 6mm, the width should be able to pass through a manhole, the material is Q235B, and the length is not less than two-thirds of the length of the straight section of the steam drum.

[0010] As a preferred option, the steam distribution plate has evenly distributed small holes, with a diameter of generally Φ10~Φ14mm and a spacing of no more than 50mm, which are evenly distributed.

[0011] The number of orifices is determined based on the boiler's evaporation rate and flow rate. The resistance of the orifice plate ensures uniform steam distribution along the length of the steam drum, preventing localized steam load concentration, reducing steam rise velocity, and facilitating gravity separation. Additionally, the orifice plate can block some small water droplets, contributing to fine separation. The ribs, including rib one and rib two, are used to reinforce the baffle assembly. The ribs are evenly distributed along the length of the steam drum.

[0012] The lower edge of the baffle assembly should be positioned 150-200mm below the normal water level of the steam drum. The minimum distance between the arc-shaped baffle and the baffle assembly should ensure a low water velocity when passing through this area. For medium and high-pressure boilers, the flow velocity on one side is approximately 4m / s. Otherwise, steam may be carried by the water flow, causing boiler water expansion or steam to flow into the downcomer, affecting the reliability of the circulation. The normal water level of the steam drum is located 150mm below the centerline of the steam drum.

[0013] Preferably, the steam-water separator is installed at a 45° angle on the upper part of the steam drum.

[0014] Preferably, the steam-water separator includes a stainless steel wire mesh, multiple corrugated plates, a bent plate, and a sealing plate. The stainless steel wire mesh is bolted to the bent plates and fixed in place. The corrugated plates are evenly distributed and fixed by the sealing plate and bent plate. Steam passes through the wire mesh and then through the corrugated plates for steam-water separation. The steam-water separation structure in a circulating fluidized bed boiler drum is generally installed on the inner wall of the drum by welding or bolting. For ease of installation and to avoid disassembly for inspection, welding is typically used. The corrugated plates are resistance-spot welded, and the stainless steel wire mesh is bolted to the bent plates and cover plate for easy disassembly and replacement. The stainless steel wire mesh is 106mm thick, 305mm wide, with 40 pieces per 100mm section, and has a diameter of 0.28mm.

[0015] Preferably, the curved plate is covered with a cover plate.

[0016] Preferably, the bottom of the bent plate is connected to a pipe, which connects to the water space inside the steam drum.

[0017] The beneficial effects of this invention are as follows: In operation, the steam-water mixture from the riser pipe first enters the first-stage steam separation space for initial separation. Water, under inertia, flows downwards along the inner wall of the steam drum and enters the water space via the slotted angle steel. The separated wet steam then enters the second-stage steam separation space, where it undergoes secondary separation by being deflected by the arc-shaped plate and passing through the steam equalization orifice plate. The separated steam enters the steam space of the steam drum, while the water is guided into the water space by the baffle plate. The steam after secondary separation rises into the steam-water separator for a third separation. The separated steam is led out through the saturated steam pipe, while the water flows into the water space of the steam drum through a pipe. This three-stage separation of the steam-water mixture effectively reduces the amount of water carried in the steam, significantly improving steam quality and enhancing the stability and reliability of the system operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 for Figure 1 A schematic diagram of the structure of part A; Figure 3 for Figure 1 The right view in the middle; Figure 4 This is a structural schematic diagram of the fixed support component; Figure 5 for Figure 1 A schematic diagram of part B in the diagram; Figure 6 for Figure 3 Enlarged view of part C in the middle; In the diagram: 100 - Arc-shaped baffle assembly; 200 - Baffle assembly; 300 - Steam-water separator; 400 - Steam drum; 500 - Saturated steam pipe; 600 - Riser pipe connector; 700 - First-stage steam separation space; 800 - Second-stage steam separation space; 900 - Steam space; 1000 - Water space; 101-Slotted angle steel; 102-T-shaped support angle; 103-Arc-shaped baffle; 104-Steel plate; 105-Arc-shaped plate; 106-Top plate; 107-End plate; 201 - Steam equalization orifice plate; 202 - Rib 1; 203 - Baffle plate; 204 - Straight plate; 205 - Rib 2; 301 - Bend plate; 302 - Pipe; 303 - Cover plate; 304 - Stainless steel wire mesh; 305 - Corrugated plate; 306 - Sealing plate; 307 - Limiting plate. Detailed Implementation

[0019] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings: Example: This utility model addresses the problem of improving steam quality in circulating fluidized bed boilers by improving the steam-water separation structure in the boiler drum. Specifically, the boiler drum 400 is arranged in a front-to-back direction, as shown below. Figure 1 A riser pipe joint 600 is welded to the opening on the outer wall along the length of the steam drum. Each riser pipe corresponds to one riser pipe joint 600. Arc-shaped baffle assemblies 100 are installed on the inner walls of both sides of the steam drum at the welding positions corresponding to the riser pipe joints 600. The front and rear sides of the arc-shaped baffle assembly 100 are sealed by end plates 107. The arc-shaped baffle assembly 100 and the inner wall of the steam drum together form the first-stage steam separation space 700. A second-stage steam separation space 800 is added based on the first-stage steam separation space 700.

[0020] The second-stage steam separation space 800 of this utility model is specifically a baffle assembly 200 installed below the arc plate 105 on the first-stage steam separation space 700. Together with the first-stage steam separation space 700, they form the second-stage steam separation space 800. The two spaces share a common end plate 107 for sealing. This steam space 800 can prevent local steam load concentration, reduce the steam rising speed, and facilitate gravity separation. In addition, the steam equalization orifice plate 201 can also block some small water droplets, playing a certain role in fine steam separation and improving the quality of boiler steam.

[0021] During operation, the steam-water mixture from the riser first enters the first-stage steam separation space 700 for initial separation. Water, under inertia, flows downwards along the inner wall of the steam drum 400 and enters the water space 1000 via the slotted angle steel 101. The separated wet steam then enters the second-stage steam separation space 800, where it undergoes secondary separation by being deflected by the arc-shaped plate 105 and passing through the steam equalization orifice plate 201. The separated steam enters the steam space 900 of the steam drum, while the water is guided by the baffle assembly 200 into the water space 1000. The steam after secondary separation rises into the steam-water separator 300 for a third separation. The separated steam is led out through the saturated steam pipe 500, while the water flows into the water space 1000 of the steam drum through the pipe 302. This three-stage separation of the steam-water mixture effectively reduces the amount of water carried in the steam, significantly improving steam quality and enhancing the stability and reliability of the system.

[0022] The arc-shaped baffle assembly 100 is installed inside the steam drum 400. The open end faces on the front and rear sides are sealed by the end plates 107. The closed area enclosed by the two end plates must completely cover all riser pipe joints 600 and ensure that the length of the area is not less than two-thirds of the length of the straight section of the steam drum, thereby forcibly changing the steam flow direction and achieving efficient steam-water separation.

[0023] like Figure 2 As shown, the installation structure of the arc-shaped baffle assembly 100 on the inner wall of the steam drum 400 is as follows: A baffle assembly 100 is installed on the inner wall of the steam drum 400. Figure 4 Fixed support components. Figure 4 The fixed support consists of a steel plate 104, a slotted angle steel 101, and a top plate 106, with an arc-shaped baffle 103 and... Figure 4 The fixed support is welded and fixed. The arc-shaped plate 105 in the arc-shaped baffle assembly 100 is located below the top plate 106 and fixed to the steel plate 104 to form a stable support system. Among them, the distance L3 between the arc-shaped baffle 103 and the inner wall of the steam drum 400 is ( Figure 1 The diameter of the small hole is 110mm, and the diameter of the hole is b1 ( Figure 3 The diameter is Φ35mm, and the spacing between the holes is L7. Figure 3 The diameter is 500mm. T-shaped support angles 102 are set at equal intervals between the arc-shaped baffle 103 and the inner wall of the steam drum 400. The T-shaped support angle 102 is welded along the edge of each hole, which not only ensures the reliability and strength of the overall support structure, but also guides the steam flow to be evenly distributed.

[0024] Figure 4 In the fixed support, the distance L5 between the top plate 106 and the steel plate 104 is 110mm, and the distance L4 between the steel plate 104 and the center of the steam drum is 235mm. The horizontal spacing L6 is ( Figure 3 The diameter is 500mm, and it is welded above the arc-shaped baffle 103 and fixed by the arc plate 105. A slotted angle steel is installed at 52.5° below the centerline of the steam drum. Several long slots are cut on the slotted angle steel 101, with a slot length L8 (…). Figure 3 The spacing is 500mm, with the slot openings facing the steam / water space at 1000mm intervals.

[0025] The baffle assembly 200 is connected by welding. A steam equalization orifice plate 201 is welded below the arc-shaped plate 105. A baffle plate 203 is connected below the steam equalization orifice plate 201. A straight plate 204 overlaps below the baffle plate 203. The baffle assembly 200 is supported and fixed by rib plate one (202) and rib plate two (205). One end of rib plate one (202) and rib plate two (205) is welded to the arc-shaped baffle plate 103, and the other end is fixed to the baffle assembly 200. They are evenly arranged to form a stable support structure.

[0026] The lower edge of the baffle assembly 200 should be positioned below the normal water level of the steam drum, at a distance of L2 ( Figure 1 The diameter of the steam drum is 150~200mm, and the length is not less than two-thirds of the straight section length of the steam drum. The steam equalization plate 201 in the baffle assembly 200 has evenly distributed small holes with a diameter b2. Figure 6 The diameter is Φ10~Φ14mm. Lateral spacing L9 ( Figure 6 The length is 35mm, and the longitudinal spacing is L10 ( Figure 6 The water level is 25mm. The normal water level is located below the 400mm centerline of the steam drum at a distance of L1 ( Figure 1 The diameter is 150mm. The steam equalization orifice plate 201 in the baffle assembly 200 uses the throttling effect of the orifice plate to make the steam evenly distributed along the length of the steam drum, which can prevent local steam load concentration, reduce the steam rising speed, and facilitate gravity separation. In addition, the steam equalization orifice plate can also block some small water droplets, which plays a certain role in fine steam separation.

[0027] Gas-water separator such as Figure 5 As shown: the tilt angle α of the steam-water separator Figure 5 The angle is 45°, and it is installed on the upper part of the steam drum. The stainless steel wire mesh 304 is connected by bolts through the cover plate 303 and the bending plate 301 for easy disassembly. The corrugated plate 305 is placed in the frame formed by the sealing plate 306 and the bending plate 301, and is limited by the limiting plate 307. The steam that has undergone secondary separation passes through the stainless steel wire mesh 304 and is separated into steam and water by multiple corrugated plates 305. The separated steam is led out through the saturated steam pipe 500, while the water flows into the steam drum water space 1000 through the pipe 302.

[0028] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A steam-water separation structure in a circulating fluidized bed boiler steam drum, comprising a steam-water separator installed on the upper part of the steam drum, its position corresponding to the saturated steam pipe joint in the horizontal direction of the steam drum, characterized in that, It also includes arc-shaped baffle assembly and baffle assembly; The arc-shaped baffle assembly is installed on the inner wall of both sides of the steam drum at the welding position of the corresponding riser pipe joint, and together with the inner wall of the steam drum, it forms the first-stage steam separation space. The baffle assembly is installed on the upper outer side of the arc-shaped baffle assembly. Together with the arc-shaped baffle assembly, it encloses the second-stage steam separation space. The bottom of the first-stage steam separation space is connected to the water space inside the steam drum, and the upper part of the first-stage steam separation space is connected to the second-stage steam separation space. The bottom of the second-stage steam separation space is connected to the water space inside the steam drum, and the upper part of the second-stage steam separation space is connected to the steam space inside the steam drum.

2. The steam-water separation structure in a circulating fluidized bed boiler steam drum according to claim 1, characterized in that, The arc-shaped baffle assembly includes an arc-shaped baffle, a fixed support component installed on the inner wall of the steam drum, two end plates on both sides, and an arc-shaped plate. The front and rear sides of the arc-shaped baffle assembly are sealed by the end plates. The fixed support component includes a slotted angle steel, a T-shaped support angle, a steel plate, and a top plate. The arc-shaped baffle is welded and fixed to the slotted angle steel, the T-shaped support angle, and the steel plate. The arc-shaped plate is located below the top plate and fixed to the steel plate.

3. The steam-water separation structure in a circulating fluidized bed boiler steam drum according to claim 1, characterized in that, The baffle assembly includes a steam equalization orifice plate, a baffle plate, a straight plate, a rib plate, and an end plate. The left and right sides of the baffle assembly are sealed by the end plates. The steam equalization orifice plate, the baffle plate, and the straight plate are welded together in sequence.

4. The steam-water separation structure in the steam drum of a circulating fluidized bed boiler according to claim 2, characterized in that, The arc-shaped baffle plate is provided with T-shaped support angles at equal intervals with the inner wall of the steam drum.

5. The steam-water separation structure in a circulating fluidized bed boiler steam drum according to claim 2, characterized in that, The arc-shaped baffle plate is concentric with the inner wall of the steam drum.

6. The steam-water separation structure in a circulating fluidized bed boiler steam drum according to claim 3, characterized in that, Small holes are evenly distributed on the steam distribution plate.

7. The steam-water separation structure in a circulating fluidized bed boiler steam drum according to claim 1, characterized in that, The steam-water separator is installed at a 45° angle on the upper part of the steam drum.

8. The steam-water separation structure in a circulating fluidized bed boiler steam drum according to claim 1, characterized in that, The steam-water separator includes a stainless steel wire mesh, multiple corrugated plates, a bent plate, a sealing plate, a cover plate, and pipes. The stainless steel wire mesh is connected and fixed to the bent plate with bolts. The corrugated plates are evenly distributed and fixed by the sealing plate and the bent plate. Steam passes through the wire mesh and then through the corrugated plates for steam-water separation.

9. The steam-water separation structure in a circulating fluidized bed boiler steam drum according to claim 8, characterized in that, The curved plate is covered by a cover plate.

10. The steam-water separation structure in a circulating fluidized bed boiler drum according to claim 8, characterized in that, The bottom of the bent plate is connected to a pipe, which connects to the water space inside the steam drum.

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