A brand new non-metal expansion joint for CFB boiler furnace outlet

Abstract

The invention discloses a novel non-metal expansion joint for a furnace outlet of a CFB boiler, comprising two correspondingly arranged metal frames, the outer ends of which are provided with joint guard rings which are fixedly connected together by bolt assemblies, inner guard plates are arranged on the inner sides of the two metal frames, an insulating sleeve is embedded and installed between the joint guard ring and the front pad, and a sealing ring A is arranged; a flow guide device is installed on the straight plate end face which is turned at a right angle at the outer end of the transverse plate of the inner guard plate and extended inward, a metal frame 1 and the inner ring of the flow guide device are paved with refractory and wear-resistant material in an integral covering manner, a refractory and wear-resistant material is paved on the inner ring of the metal frame 2 separately, and a high-temperature medium flow channel is formed in the middle; an anti-ash pad is installed in the gap between the integral refractory and wear-resistant material and the separately paved refractory and wear-resistant material. The invention adopts effective measures to prevent smoke from backflowing while satisfying the expansion in three-dimensional directions, avoids burning of the insulation layer and the skin, solves the safety hazards of cracking, burning, ash spraying and the like of the non-metal expansion joint at the inlet of the furnace-separator of a large CFB boiler, and prolongs the service life of the expansion joint.

Description

Technical Field

[0001] The invention relates to the technical field of thermal power facilities, in particular to a brand-new non-metal expansion joint at a furnace outlet of a CFB boiler. Background Art

[0002] The CFB boiler body is divided into three independent suspension and support parts: furnace, separator and tail shaft. The expansion joints are used to connect and seal each part. As a key component of the circulating fluidized bed boiler, the performance of the expansion joint directly affects the safe operation of the boiler. The characteristics and overall layout of the CFB boiler require that the non-metal expansion joint effectively absorb the expansion volume, without leakage or burning.

[0003] The three-dimensional expansion of the CFB boiler in the high-temperature area and the three-dimensional expansion furnace-separator inlet area is absorbed by non-metallic expansion joints. This area is a dense phase area with a harsh working environment, a long-term operating temperature of 1100°C, a high ash content in the flue gas medium, and negative pressure;

[0004] The separator inlet (furnace outlet) is the pressure balance point for CFB boiler operation control, and the furnace negative pressure (measured at the furnace outlet balance point) is controlled at -127 to -245 Pa. If the pressure reaches a pressure value of ±2489 Pa, the main fuel cut-off (MFT) will be triggered, and the pressure value reaching ±3744 Pa will trigger the cut-off of the induced draft fan.

[0005] Damage to the furnace-separator non-metallic expansion joint can easily lead to the following hidden dangers during boiler operation:

[0006] 1) The boiler air leakage increases. In order to maintain the negative pressure at the separator inlet (furnace outlet), the induced draft fan needs to increase its output, resulting in an increase in plant electricity consumption. If the induced draft fan margin is insufficient to compensate for the pressure change caused by the air leakage, the boiler MFT will be activated.

[0007] 2) During long-term operation of a CFB boiler, the furnace pressure will fluctuate within a certain range. If the expansion joint ruptures, the flue gas from the boiler will leak out, causing the operating environment of the power plant to deteriorate, which is not conducive to civilized production.

[0008] 3) After the expansion joint ruptures, the flue gas temperature at the furnace outlet decreases, which is not conducive to the heat transfer of the tail flue gas. In severe cases, it will cause insufficient heat absorption of the tail heating surface, reduce the steam temperature of the superheater and reheater, and affect the boiler performance. Summary of the invention

[0009] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a brand-new non-metal expansion joint for the furnace outlet of a CFB boiler, comprising two correspondingly arranged metal frames, a joint guard ring is arranged at the outer end and fixedly connected as a whole by a bolt assembly, inner guard plates are arranged on the inner sides of the two metal frames, an insulating sleeve is embedded and installed between the joint guard ring and the front pad, and a sealing ring A is arranged; a flow guide device is installed on the straight plate end face of the inner guard plate which is turned at a right angle at the outer end of the horizontal plate and extended inward, the inner ring of the metal frame one and the flow guide device is covered with refractory and wear-resistant materials as a whole, and the inner ring of the metal frame two is separately paved with refractory and wear-resistant materials, forming a middle High-temperature medium flow channel; an anti-ash pad is installed in the gap between the integral refractory and wear-resistant material and the separately laid refractory and wear-resistant material. The present invention not only meets the three-dimensional expansion, but also adopts effective measures to prevent the flue gas from flowing back, avoids burning the insulation layer and the skin, and solves the safety hazards of cracking, burning, and ash spraying of the non-metallic expansion joint at the inlet of the furnace-separator of a large CFB boiler. The expansion joint adopts a full labyrinth structure and is designed with a total of several mutual protection measures. While completely absorbing the three-dimensional expansion, it effectively prevents the high-temperature ash-containing flue gas from flowing out, reduces the possibility of the expansion joint being burned, and ensures and extends the service life of the expansion joint.

[0010] To achieve the above-mentioned purpose, the technical scheme of the present invention is: a brand-new non-metal expansion joint at the furnace outlet of a CFB boiler, comprising a correspondingly arranged metal frame 1 and a metal frame 2, the outer right-angled edge of the left end of the metal frame 1 is turned outward to the left to form a platform, and the outer right-angled edge of the right end of the metal frame 2 is turned left to form a platform, and the two ends of the joint guard ring are respectively placed on the left-turned platform of the metal frame 1 and the left-turned platform of the metal frame 2, and the upper sides of the two ends of the joint guard ring are provided with clamping flanges. After the two ends of the mounting assembly are placed on the clamping flanges at the two ends, the screws and nuts of the bolt assembly fix the metal frame 1 and the metal frame 2, the joint guard ring, the clamping flange, and the mounting assembly together;

[0011] The inner side surface of the metal frame 1 is provided with an inner guard plate 2, and the inner side surface of the metal frame 2 is provided with an inner guard plate 1. The outer ends of the transverse plates of the inner guard plate 2 and the inner guard plate 1 turn at right angles and extend inwardly toward the center. The outer ends of the transverse plates of the inner guard plate 2 and the inner guard plate 1 turn at right angles and extend inwardly. The outer end surfaces of the two pieces of the partition plates 1 are in contact and fit together.

[0012] Front pads are installed at the outer ends of the inner guard plate 2 and the inner guard plate 1 transverse plates, and the two ends of the front pads are respectively fixedly connected with the inner guard plate 2 and the inner guard plate 1 transverse plates by bolt assemblies mounted on the front pad pressure plates;

[0013] The insulation sleeve 1 is embedded and installed between the combined guard ring and the front gasket, the insulation sleeve 2 is sleeved on the outer end of the insulation sleeve 1, the inner end surface of the insulation sleeve 1 is in contact with the front gasket, and the outer end surface of the insulation sleeve 2 is in contact with the combined guard ring 4;

[0014] A sealing ring A is provided between the front pad and the transverse plates of the inner guard plate 2 and the inner guard plate 1;

[0015] The outer ends of the transverse plates of the inner guard plate 2 and the inner guard plate 1 are turned at right angles and the straight plate end surfaces extending inward are provided with flow guide devices, and a sealing ring B is provided between the flow guide devices and the transverse plates of the inner guard plate 2 and the inner guard plate 1;

[0016] The guide device is a square structure composed of a plurality of guide plates connected in a fish scale-like manner. A raised partition plate 2 is provided at one end of the guide plate. When installed, the partition plate 2 is placed on the rear end of the guide plate at the front end for bridging.

[0017] The inner ring of the metal frame 1 and the guide device is covered with refractory and wear-resistant materials as a whole, and the inner ring of the metal frame 2 is separately paved with refractory and wear-resistant materials, and a high-temperature medium flow channel is formed in the middle of the refractory and wear-resistant materials;

[0018] The inner spaces of the metal frame 1 and the metal frame 2 are separated by a plurality of square rib plates, and the separated spaces are embedded with heat insulation materials, which are fixed to the metal frame 1 and the metal frame 2 at corresponding positions by a plurality of casting material Y nails;

[0019] A gap is provided between the integral refractory and wear-resistant material laid on the inner ring of the metal frame 1 and the guide device and the refractory and wear-resistant material laid separately on the inner ring of the metal frame 2 9, and an anti-ash pad is installed in the gap;

[0020] The outer sides of the metal frame 1 and the metal frame 2 are evenly distributed with reinforcing ribs.

[0021] It is further provided that the combined guard ring and the front gasket are both made of heat-resistant composite materials.

[0022] It is further provided that the sealing ring A is formed by integral multi-layer composite molding of a ceramic fiber blanket.

[0023] It is further provided that the first insulation sleeve and the second insulation sleeve are integrally formed of multi-layer composites of high-purity high-aluminum fibers.

[0024] It is further provided that the sealing ring B is a ceramic fiber rope.

[0025] It is further provided that the anti-dust pad is integrally formed of aluminum silicate fibers.

[0026] The beneficial effects of the present invention are as follows: while satisfying the expansion in three-dimensional directions, the present invention adopts effective measures to prevent the backflow of flue gas, avoids burning of the insulation layer and the skin, and solves the safety hazards of cracking, burning, and ash spraying of the non-metallic expansion joint at the inlet of the furnace-separator of a large CFB boiler. The expansion joint adopts a full labyrinth structure and is designed with a total of several measures for mutual protection. While completely absorbing the expansion in three-dimensional directions, it effectively prevents the outflow of high-temperature ash-containing flue gas, reduces the possibility of the expansion joint being burned, and ensures and extends the service life of the expansion joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention;

[0028] Figure 2 for Figure 1 A top view schematic diagram of

[0029] Figure 3 for Figure 1 Left side view of the middle guide device;

[0030] Figure 4 for Figure 3 Connection diagram of the center guide plate.

[0031] In the figure: metal frame 1, clamping flange 2, installation assembly 3, joint guard ring 4, sealing ring A5, insulation sleeve 1 6, insulation sleeve 2 7, bolt assembly 8, metal frame 2 9, inner guard plate 1 10, partition 1 11, casting material Y nail 12, inner guard plate 2 13, sealing ring B 14, front pad pressure plate 15, dust-proof pad 16, guide device 17, guide plate 171, partition 2 172, square rib plate 18, reinforcing rib plate 19, front pad 20, refractory and wear-resistant material 21. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0033] like Figure 1 , Figure 2 As shown, a new non-metal expansion joint at the furnace outlet of a CFB boiler includes a correspondingly arranged metal frame 1 and a metal frame 2 9, the outer right-angled edge of the left end of the metal frame 1 is turned outward to the left to form a platform, and the outer right-angled edge of the right end of the metal frame 2 9 is turned left to form a platform, and the two ends of the combined guard ring 4 made of heat-resistant composite materials are respectively placed on the left-turned platform of the metal frame 1 and the left-turned platform of the metal frame 2 9, and the upper sides of the two ends of the combined guard ring 4 are provided with clamping flanges 2. After the two ends of the mounting assembly 3 are placed on the clamping flanges 2 at the two ends, the screws and nuts of the bolt assembly 8 fix the metal frame 1 and the metal frame 2 9, the clamping flange 2 of the combined guard ring 4, and the mounting assembly 3 together;

[0034] An inner guard plate 13 is provided on the inner side of the metal frame 1, and an inner guard plate 10 is provided on the inner side of the metal frame 9. The outer ends of the horizontal plates of the inner guard plate 13 and the inner guard plate 10 turn right angles and extend inwards toward the center. The outer ends of the horizontal plates of the inner guard plate 13 and the inner guard plate 10 turn right angles and extend inwards. A partition plate 11 is provided in a horizontal direction and in a corresponding position. The outer end surfaces of the two partition plates are in contact and fit together.

[0035] A front pad 20 made of a heat-resistant composite material is installed at the outer ends of the inner guard plate 2 13 and the inner guard plate 1 10 transverse plate, and the two ends of the front pad 20 are respectively fixedly connected to the inner guard plate 2 13 and the inner guard plate 10 transverse plate by a bolt assembly 8 fitted with a front pad pressure plate 15; an insulating sleeve 6 is embedded and installed between the joint guard ring 4 and the front pad 20, and an insulating sleeve 2 7 is fitted on the outer end of the insulating sleeve 6, and the inner end surface of the insulating sleeve 6 is in contact with the front pad 20, and the outer end surface of the insulating sleeve 2 7 is in contact with the inner end surface of the insulating sleeve 6. The combined guard ring 4 is fitted; a sealing ring A5 is arranged between the front pad 20 and the transverse plates of the inner guard plate 2 13 and the inner guard plate 1 10; the sealing ring A5 is an integral multi-layer composite molding of a ceramic fiber blanket, with a precise structure, stable performance, high temperature resistance and deformation resistance, and a flow guide device 17 is installed on the straight plate end face of the inner guard plate 2 13 and the inner guard plate 10 that turns at a right angle at the outer end of the transverse plate and extends inward, and a sealing ring B14 is arranged between the flow guide device 17 and the transverse plates of the inner guard plate 2 13 and the inner guard plate 10.

[0036] like Figure 3 , Figure 4 As shown, the guide device 17 is a square structure composed of a plurality of guide plates 171 bridged in a fish scale manner. A raised partition plate 172 is provided at one end of the guide plate 171. When installed, the partition plate 172 is placed on the rear end of the guide plate 171 at the front end to bridge the rear end, which can fully adapt to and accommodate the adaptive adjustment and buffering of the three-dimensional deformation of the non-metallic expansion joint.

[0037] The inner circles of the metal frame 1 and the guide device 17 are integrally covered with refractory and wear-resistant materials 21, and the inner circle of the metal frame 2 9 is separately paved with refractory and wear-resistant materials 21. A high-temperature medium flow channel is formed in the middle of the refractory and wear-resistant materials 21. The inner spaces of the metal frame 1 and the metal frame 2 9 are separated by a plurality of square rib plates 18. The separated spaces are embedded with heat insulating materials. The heat insulating materials are fixed to the metal frame 1 and the metal frame 2 9 at corresponding positions with a plurality of casting material Y nails 12 to improve the overall strength and rigidity.

[0038] There is a gap between the integral refractory and wear-resistant material 21 laid on the inner circle of the metal frame 1 and the guide device 17 and the refractory and wear-resistant material 21 laid separately on the inner circle of the metal frame 2 9, and an anti-ash pad 16 is installed in the gap, which is beneficial to effectively prevent particles in the medium flow channel from entering through the gap between the refractory and wear-resistant materials 21 on both sides when the metal frame 1 and the metal frame 2 9 of the non-metallic expansion joint are three-dimensionally deformed due to high temperature.

[0039] The outer sides of the metal frame 1 and the metal frame 2 9 are evenly distributed with reinforcing ribs 19 to improve the overall rigidity and strength of the non-metal expansion joint.

[0040] The technical solution structure of the present invention has the following innovative features and protective measures:

[0041] 1. The non-metal expansion joint frame is expanded and raised, and the full labyrinth structure is moved outward. Without reducing the internal circulation clearance, a layer of refractory and wear-resistant material is laid on the guide plate guide device 17. The refractory and wear-resistant material is laid along the circumference of the expansion joint, which can improve the wear resistance and temperature resistance of the guide plate;

[0042] 2. The guide device 17 is arranged in a circle along the circumference of the expansion joint and adopts a fish scale design. The main purpose is to eliminate and release the expansion of the guide plate after heating, and prevent the refractory and wear-resistant material from falling off after the guide plate 171 is deformed by heat;

[0043] 3. There is an anti-ash pad 16 at the bottom of the expansion joint, the main purpose of which is to prevent dust in the flue gas from entering the expansion joint at the bottom of the expansion joint during long-term operation of the boiler;

[0044] 4. A sealing ring B14 is designed on the inner side of the guide plate. The material is ceramic fiber braided rope. Through its strong and resilient braided fabric characteristics, it prevents medium fly ash from entering and depositing in the expansion joint to hinder the expansion joint from absorbing three-dimensional displacement, and also prevents smoke from leaking out;

[0045] 5. In order to prevent the sealing ring B14 from loosening or falling off after long-term operation, a partition 11 is designed on the outside of the sealing ring B14. The material is 310S. The purpose is to connect the upper and lower parts, compress the sealing ring B14, and at the same time support the sealing ring A5 to prevent it from falling;

[0046] 6. On the outside of the partition, a sealing ring A5 is designed, which is made of multiple layers of aluminum silicate wool blanket. Its main purpose is to continue to prevent smoke and fly ash from escaping;

[0047] 7. The expansion joint is designed with an inner guard plate 10 and an inner guard plate 2 13, which are arranged on both sides of the expansion joint respectively. The main purpose is to fix the sealing ring A5 and the sealing ring B14, fix the castable inside the expansion joint, fix the front pad 20, and protect the insulation sleeve 1 6 and the insulation sleeve 2 7 inside the expansion joint frame;

[0048] 8. A front pad 20 is designed between the two inner guard plates 10 and 13, and is fixed to the inner guard plates 10 and 13 with fasteners to prevent the seal ring A5 and the seal ring B14 in the expansion joint from having a gap after the product loses its elasticity after long-term use. A small amount of ash-containing smoke will enter the expansion joint and escape outside, and the front pad will prevent this phenomenon from occurring;

[0049] 9. Outside the front pad, there is a heat-insulating sleeve 6, which is formed by ceramic fiber cloth wrapped with high-purity high-aluminum wool, to prevent the high-temperature ash-containing smoke from leaking out;

[0050] 10. On the outside of the insulation sleeve 1 6, a insulation sleeve 2 7 is designed, which is formed by ceramic fiber cloth wrapped with high-purity high-aluminum wool as a whole, and continues to prevent the high-temperature ash-containing flue gas from leaking out;

[0051] 11. The outermost side of the expansion joint is designed with a joint guard ring 4, which is composed of multiple layers of heat-resistant, corrosion-resistant, sealing materials and aluminum silicate wool. It mainly absorbs expansion displacement and has the final sealing function;

[0052] 12. The internal castable gripping nails 12 of the expansion joint should be arranged and welded on the frames on both sides of the expansion joint as much as possible. The main reason is to prevent the castable from cracking in the state, to protect the frames on both sides of the expansion joint to the maximum extent and avoid the risk of the frames being burned through;

[0053] 13. A square rib plate 18 is designed between the inner guard plate 13 and the metal frame 1. The square rib plate is mainly used to reduce the deformation of the inner guard plate 13 after being heated, and to avoid the falling off of the refractory and wear-resistant material after the deformation.

[0054] The above shows and describes the basic principles and main features of the present invention, as well as the advantages of the present invention. Those skilled in the art will also understand that the present invention is not limited to the above implementation cases, and the above implementation cases and descriptions are only for explaining the principles of the present invention. Without departing from the design scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A brand new non-metal expansion joint for CFB boiler furnace outlet, characterized by: It comprises a correspondingly arranged metal frame one (1) and a metal frame two (9), wherein the outer end right-angled edge of the metal frame one (1) at the left end is turned outward to the left to form a platform, and the outer end right-angled edge of the metal frame two (9) at the right end is turned left to form a platform, and the two ends of the combined guard ring (4) are respectively placed on the left-turned outward platform of the metal frame one (1) and the left-turned platform of the metal frame two (9), and the upper sides of the two ends of the combined guard ring (4) are provided with clamping flanges (2). After the two ends of the mounting assembly (3) are placed on the clamping flanges (2) at the two ends, the screws and nuts of the bolt assembly (8) fix the metal frame one (1) and the metal frame two (9), the clamping flange (2) of the combined guard ring (4), and the mounting assembly (3) together; The inner side surface of the metal frame one (1) is provided with an inner guard plate two (13), and the inner side surface of the metal frame two (9) is provided with an inner guard plate one (10). The outer ends of the transverse plates of the inner guard plate two (13) and the inner guard plate one (10) turn right angles and extend inwards toward the center. The outer ends of the transverse plates of the inner guard plate two (13) and the inner guard plate one (10) turn right angles and extend inwards. Both of them are provided with a transverse partition plate one (11) with corresponding positions. The outer end surfaces of the two partition plates one are in contact and fit together. Front pads (20) are installed at the outer ends of the transverse plates of the inner guard plate 2 (13) and the inner guard plate 1 (10), and the two ends of the front pads (20) are respectively fixedly connected to the transverse plates of the inner guard plate 2 (13) and the inner guard plate 1 (10) by bolt assemblies (8) mounted on the front pad pressure plates (15); A heat-insulating sleeve 1 (6) is embedded and installed between the combined protective ring (4) and the front gasket (20); a heat-insulating sleeve 2 (7) is sleeved on the outer end of the heat-insulating sleeve 1 (6); the inner end surface of the heat-insulating sleeve 1 (6) is in contact with the front gasket (20); and the outer end surface of the heat-insulating sleeve 2 (7) is in contact with the combined protective ring (4); A sealing ring A (5) is provided between the front pad (20) and the inner guard plate 2 (13) and the transverse plate of the inner guard plate 1 (10); A flow guide device (17) is installed on the straight plate end surface that turns at right angles and extends inwards at the outer ends of the transverse plates of the inner guard plate 2 (13) and the inner guard plate 1 (10), and a sealing ring B (14) is provided between the flow guide device (17) and the transverse plates of the inner guard plate 2 (13) and the inner guard plate 1 (10); The guide device (17) is a square structure composed of a plurality of guide plates (171) connected in a fish scale-like manner. A raised partition plate 2 (172) is provided at one end of the guide plate (171). When installed, the partition plate 2 (172) is placed on the rear end of the guide plate (171) at the front end for bridging. The inner rings of the metal frame 1 (1) and the guide device (17) are integrally covered with refractory and wear-resistant materials (21), and the inner ring of the metal frame 2 (9) is separately paved with refractory and wear-resistant materials (21), and a high-temperature medium flow channel is formed between the refractory and wear-resistant materials (21); The inner spaces of the metal frame 1 (1) and the metal frame 2 (9) are separated by a plurality of square rib plates (18), and heat insulation materials are embedded in the separated spaces. The heat insulation materials are fixed to the metal frame 1 (1) and the metal frame 2 (9) at corresponding positions by a plurality of casting material Y nails (12); A gap is provided between the integral refractory and wear-resistant material (21) laid on the inner ring of the metal frame 1 (1) and the guide device (17) and the refractory and wear-resistant material (21) laid separately on the inner ring of the metal frame 2 (9), and an anti-ash pad (16) is installed in the gap; The outer sides of the metal frame 1 (1) and the metal frame 2 (9) are evenly distributed with reinforcing ribs (19).

2. A new non-metal expansion joint for a CFB boiler furnace outlet as claimed in claim 1, characterized in that: The combined guard ring (4) and the front pad (20) are both made of heat-resistant composite materials.

3. A new non-metal expansion joint for a CFB boiler furnace outlet as claimed in claim 1, characterized in that: The sealing ring A (5) is formed by integrally forming a multi-layer composite of ceramic fiber blankets.

4. A new non-metal expansion joint for a CFB boiler furnace outlet as claimed in claim 1, characterized in that: The thermal insulation sleeve 1 (6) and the thermal insulation sleeve 2 (7) are integrally formed of multi-layer composites of high-purity high-aluminum fibers.

5. A new non-metal expansion joint for a CFB boiler furnace outlet as claimed in claim 1, characterized in that: The sealing ring B (14) is a ceramic fiber rope.

6. A new non-metal expansion joint for a CFB boiler furnace outlet as claimed in claim 1, characterized in that: The dust-proof pad (16) is integrally formed of aluminum silicate fibers.

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