Compact double-leg steam-cooled material returning device structure
By setting up a membrane wall pipe screen and return leg expansion joint in the steam-cooled returner, a compact two-legged air-cooled returner structure is achieved, which solves the problem that the returner in the prior art cannot meet the needs of multiple return ports, improves the boiler efficiency and peak shaving capacity of the power plant, and reduces maintenance and operation costs.
Patent Information
- Application Number
- CN202421245062.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-03
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-06-03
AI Technical Summary
The existing vapor-cooled returner structure can only return the material to one return port of the boiler, and cannot meet the needs of multiple return ports in a limited space.
The compact two-legged air-cooled returner structure is adopted. By setting up a membrane-type wall pipe screen between the inlet, outlet and lower container of the returner to form a return channel, the return of multiple return ports is realized and connected to the furnace through the return leg expansion joint.
This design reduces the thickness and amount of castable material, reduces the construction cycle and difficulty, avoids the problem of overtemperature temperature of the steel plate outer wall, improves the boiler efficiency and peak shaving capacity of the power plant, and reduces maintenance and operation costs.
Smart Images
Figure CN222597710U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of circulating fluidized beds, in particular to a compact double-leg steam-cooled material return device structure. Background Art
[0002] Circulating fluidized bed boiler is a high-efficiency, low-pollution combustion technology that has developed rapidly in recent decades. Figure 1 As shown, the circulating fluidized bed boiler comprises a furnace 1, a cyclone separator 4, a cyclone separator outlet flue 2, a tail flue 3 and a return device 5. The flue gas carrying solid particles after combustion in the furnace 1 enters the cyclone separator 4. After separation by the cyclone separator 4, the flue gas and the fly ash particles not separated by the cyclone separator 4 are sent to the tail flue 3 through the cyclone separator outlet flue 2 for heat exchange, and the solid particles separated by the cyclone separator 4 are sent back to the furnace 1 through the return device 5 for circulating combustion.
[0003] At present, the common circulating fluidized bed boiler return feeders at home and abroad are basically steel plate type (insulated) structures. Three layers of wear-resistant refractory materials, namely calcium silicate board, insulation castable and wear-resistant castable, are arranged in sequence inside the steel plate. In order to reduce the temperature of the outer surface, the total thickness of the wear-resistant refractory material is generally about 400mm. The disadvantages of this structure are: the surface temperature of the steel plate is high, it is very easy to overheat, the lining weight is large, the quality and construction process of the lining refractory and wear-resistant materials are high, and the maintenance cost of the refractory material is high. As the boiler operation cycle increases, the castable ages, and the thermal insulation performance decreases, resulting in overheating and red-burning of the outer surface of the flue, reducing the efficiency of the boiler and increasing safety risks. At the same time, the castable is thicker, and the overall maintenance cost is higher. In order to prevent the castable from cracking and falling off, the start and stop of the boiler and the variable load rate are limited, which reduces the ability of the power plant to respond to the peak load regulation of the power grid, increases the operating cost, and reduces the economic efficiency of the unit.
[0004] In addition, the traditional steel plate type returner adopts a supporting structure, the steam cooling separator adopts a suspension structure, and an expansion joint is used in the middle to absorb the expansion. However, according to feedback from many power plants, the expansion joint is easy to get stuck during operation, causing the upper part of the separator to be bent, causing serious safety hazards.
[0005] In recent years, the research on cooling recyclers with low outer surface temperature and small load has become a hot topic.
[0006] In order to improve the high temperature of the outer wall of the steel plate in the traditional structure and the phenomenon that it is very easy to overheat, the Chinese utility model patent with the announcement number CN216131917U provides a steam-cooled re-feeder structure, in which membrane wall tube screens are connected between the re-feeder inlet header, the air distribution plate header and the re-feeder outlet header. The cooling design of introducing steam into each of the membrane wall tube screens improves the situation that the outer wall temperature is too high or even red in the traditional structure, avoids the heavy casting material of the traditional casting type re-feeder, and reduces the overall weight of the re-feeder. However, this type of re-feeder structure can only re-feed one re-feeding port of the boiler. When the boiler is designed with multiple re-feeding ports, multiple re-feeders need to be configured for re-feeding, which occupies a large amount of space; in order to obtain higher energy utilization, the design of circulating fluidized bed boilers continues to develop in the direction of large-scale, but due to space limitations, it is impossible to configure enough re-feeders. Utility Model Content
[0007] The utility model aims to provide a compact double-leg steam-cooled material return device structure to solve the problem that the existing steam-cooled material return device structure can only return material to one return port of the boiler and cannot meet the return material demand in a limited space.
[0008] The utility model is realized by adopting the following technical solutions:
[0009] The utility model provides a compact double-leg steam-cooled recycler structure, comprising a recycler leg inlet header, a recycler leg outlet header, a recycler lower header and a recycler outlet header, membrane wall tube screens are arranged between the recycler leg inlet header and the recycler leg outlet header, between the recycler leg inlet header and the recycler outlet header, between the recycler leg outlet header and the recycler lower header, and between the recycler lower header and the recycler outlet header, the recycler leg inlet header, the recycler leg outlet header, the recycler lower header, the recycler outlet header and each of the membrane wall tube screens together form a recycler channel;
[0010] The return leg inlet header comprises a left return leg inlet header and a right return leg inlet header, the left return leg inlet header and the right return leg inlet header respectively correspond to a return port of the furnace of the circulating fluidized bed boiler, and the left return leg inlet header and the right return leg inlet header are respectively connected to the furnace through a return leg expansion joint;
[0011] The reclaimer outlet header is connected to a cyclone separator.
[0012] As the preferred technical solution:
[0013] The return material outlet header is connected to the return material port of the cyclone separator.
[0014] As the preferred technical solution:
[0015] The smoke outlet of the cyclone separator is connected to a cyclone separator outlet flue, and the cyclone separator outlet flue is connected to the tail flue through a flue expansion joint.
[0016] As the preferred technical solution:
[0017] The left-side return leg inlet header and the right-side return leg inlet header are both connected to a plurality of return device inlet connecting pipes.
[0018] As the preferred technical solution:
[0019] The left side return leg front wall membrane type wall tube screen, the right side return leg front wall membrane type wall tube screen, the left side return leg rear wall membrane type wall tube screen, the right side return leg rear wall membrane type wall tube screen, the left side return leg outer wall membrane type wall tube screen, and the right side return leg outer wall membrane type wall tube screen are connected between the return leg inlet header and the return leg outlet header;
[0020] The inner wall membrane type wall tube panel of the left return leg and the inner wall membrane type wall tube panel of the right return leg are connected between the return leg inlet header and the return device outlet header.
[0021] As the preferred technical solution:
[0022] The membrane wall tube panel between the return leg inlet header and the return leg outlet header is vertically connected to the return leg outlet header.
[0023] As the preferred technical solution:
[0024] A left-side return leg hanging structure and a right-side return leg hanging structure are provided on the membrane wall tube panel between the return leg inlet header and the return leg outlet header.
[0025] As the preferred technical solution:
[0026] The lower header of the return material device includes a lower rear wall header of the return material device and a lower front wall header of the return material device;
[0027] The return leg outlet header and the lower front wall header of the return material device are connected by a membrane wall tube screen from the return leg outlet header to the lower front wall header of the return material device; the return leg outlet header and the lower rear wall header of the return material device are connected by a membrane wall tube screen from the return leg outlet header to the lower rear wall header of the return material device.
[0028] As the preferred technical solution:
[0029] A plurality of hoods are arranged on the membrane wall tube screen between the return leg outlet header and the lower rear wall header of the return device.
[0030] As the preferred technical solution:
[0031] The lower front wall header of the return material device is connected to the return material device outlet header by a membrane wall tube screen from the lower front wall header of the return material device to the return material device outlet header; the lower rear wall header of the return material device is connected to the return material device outlet header by a membrane wall tube screen from the lower rear wall header of the return material device to the return material device outlet header.
[0032] As the preferred technical solution:
[0033] The return device outlet header and the cyclone separator are connected by a vertical membrane wall tube screen at the lower part of the separator.
[0034] As the preferred technical solution:
[0035] A cyclone separator outlet annular header is arranged on the top of the cyclone separator, and a cyclone separator outlet annular header hanging structure is arranged on the cyclone separator outlet annular header.
[0036] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:
[0037] 1. The utility model adopts membrane wall tube screen as the channel, and the thickness and amount of castables are greatly reduced, which greatly reduces the period and difficulty of castable construction, and is conducive to the later operation, maintenance and overhaul of the boiler; at the same time, it solves the problem that the outer wall temperature of the steel plate in the traditional structure is easy to overheat or even burn red, reduces heat dissipation loss, and improves boiler efficiency; in addition, it can also improve the start-stop and load change rate of the circulating fluidized bed boiler, and improve the power plant's ability to respond to the peak load regulation of the power grid. The reduction of castables, the reduction of maintenance costs and the increase of load change rate are conducive to improving the economic efficiency of power plant units.
[0038] 2. The return leg inlet header of the utility model is connected to the furnace through the return device expansion joint. The cyclone separator outlet annular header at the top of the cyclone separator is provided with a cyclone separator outlet annular header hanging structure to bear the load of the cyclone separator itself and the load of the return device descending section. At the same time, the plane where the rigid suspension is located is used as the expansion zero point of the cyclone separator in the vertical direction. During the operation of the boiler, the outlet flue of the cyclone separator expands upward, and the cyclone separator and the return device expand downward together, thereby avoiding the bending of the upper suspension of the separator and avoiding the occurrence of such safety hazards.
[0039] 3. The utility model is provided with a left-side return leg inlet header and a right-side return leg inlet header, which can make the return material more uniform.
[0040] 4. The connection between the steam-cooled return feeder and the two steam-cooled return feeder legs is connected at a 90-degree right angle, which makes the steam-cooled return feeder smaller in size, more compact in structure, uses less pipes and refractory materials, has a smaller load, and is more convenient to arrange.
[0041] 5. Due to the space limitation in the width direction of the boiler, as well as the structural and performance requirements of a single return leg, a membrane wall tube screen is used. Currently, a single return device corresponds to a maximum of two return ports, and it is structurally impossible to achieve three return ports. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1 It is a structural schematic diagram of a circulating fluidized bed boiler in the prior art.
[0043] Figure 2 It is a side view of the compact double-leg steam-cooled material return device structure described in the utility model.
[0044] Figure 3 It is a front view of the compact double-leg steam-cooled material return device structure described in the utility model.
[0045] Figure 4 It is a three-dimensional structural schematic diagram of the compact double-leg steam-cooled material return device structure described in the utility model.
[0046] Icons: 1-furnace, 2-cyclone separator outlet flue, 3-tail flue, 4-cyclone separator, 5-return device, 11-return device inlet connecting pipe, 12-return leg expansion joint, 13-left return leg inlet header, 14-right return leg inlet header, 15-left return leg front wall membrane wall tube screen, 16-right return leg front wall membrane wall tube screen, 17-left return leg rear wall membrane wall tube screen, 18-right return leg rear wall membrane wall tube screen, 19-left return leg outer wall membrane wall tube screen, 20-right return leg outer wall membrane wall tube screen, 21-return leg outlet header to the membrane wall tube screen between the return leg front wall header and the lower part of the return device, 22-return leg outlet header to the return 1-Membrane wall tube screen between the lower rear wall headers of the return material feeder, 23-the lower front wall header of the return material feeder, 24-the lower rear wall header of the return material feeder, 25-the membrane wall tube screen between the lower front wall header of the return material feeder and the return material feeder outlet header, 26-the membrane wall tube screen between the lower rear wall header of the return material feeder and the return material feeder outlet header, 27-the return material feeder outlet header, 28-the membrane wall tube screen at the lower vertical section of the separator, 29-the left return material leg hanging structure, 30-the right return material leg hanging structure, 31-the cyclone separator outlet annular header, 32-the cyclone separator outlet annular header hanging structure, 33-the membrane wall tube screen on the inner wall of the left return material leg, 34-the membrane wall tube screen on the inner wall of the right return material leg, 35-the return material leg outlet header. DETAILED DESCRIPTION
[0047] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0048] Example 1
[0049] like Figure 2-Figure 4 As shown, this embodiment proposes a compact double-leg steam-cooled recycler structure, including a recycler leg inlet header, a recycler leg outlet header 35, a recycler lower header and a recycler outlet header 27. Membrane wall tube screens are arranged between the recycler leg inlet header and the recycler leg outlet header 35, between the recycler leg inlet header and the recycler outlet header 27, between the recycler leg outlet header 35 and the recycler lower header, and between the recycler lower header and the recycler outlet header 27. The recycler leg inlet header, the recycler leg outlet header 35, the recycler lower header, the recycler outlet header 27 and each of the membrane wall tube screens together form a recycler channel. One end of the return channel is connected to the return port of the cyclone separator, and the other end is connected to the furnace. Specifically, the return outlet header 27 is connected to the cyclone separator; the smoke outlet of the cyclone separator is connected to the cyclone outlet flue. The return channel, the cyclone separator and the cyclone outlet flue together constitute an integrated steam-cooled separator structure to replace the traditional design of a circulating fluidized bed boiler. The return channel returns the large particles captured by the cyclone separator to the furnace for circulating combustion. At the same time, the steam from the return outlet header 27 flows into the cyclone separator.
[0050] The design of the return channel can greatly improve the problem of the outer wall of the traditional steel plate structure being prone to overheating or even burning red by steam cooling during the return process.
[0051] In this embodiment, the return leg inlet header and the return device outlet header 27 are both designed to be rectangular, and the return leg outlet header 35 is designed to be semi-rectangular.
[0052] The return leg inlet header includes a left return leg inlet header 13 and a right return leg inlet header 14; the return device lower header includes a return device lower rear wall header 24 and a return device lower front wall header 23.
[0053] The left return leg inlet header 13 and the right return leg inlet header 14 respectively correspond to a return port of the circulating fluidized bed boiler furnace, and the left return leg inlet header 13 and the right return leg inlet header 14 are respectively connected to the furnace through a return leg expansion joint 12, and the return leg expansion joint 12 can absorb the expansion difference between the return device structure, the cyclone separator and the furnace water-cooled wall.
[0054] The left return leg inlet header 13 and the right return leg inlet header 14 are both connected to a plurality of return device inlet connecting pipes 11, and steam enters the left return leg inlet header 13 and the right return leg inlet header 14 through the return device inlet connecting pipes 11. In this embodiment, the left return leg inlet header 13 and the right return leg inlet header 14 are respectively connected to three return device inlet connecting pipes 11.
[0055] The return leg inlet header and the return leg outlet header 35 are connected with the left return leg front wall membrane wall tube screen 15, the right return leg front wall membrane wall tube screen 16, the left return leg rear wall membrane wall tube screen 17, the right return leg rear wall membrane wall tube screen 18, the left return leg outer wall membrane wall tube screen 19, and the right return leg outer wall membrane wall tube screen 20.
[0056] The inner wall membrane tube panel 33 of the left return leg and the inner wall membrane tube panel 34 of the right return leg are connected between the return leg inlet header and the return device outlet header 27 .
[0057] The left return leg inlet header 13 is combined with the left return leg front wall membrane wall tube screen 15, the left return leg rear wall membrane wall tube screen 17, the left return leg inner wall membrane wall tube screen 33, and the left return leg outer wall membrane wall tube screen 19; the right return leg inlet header 14 is combined with the right return leg front wall membrane wall tube screen 16, the right return leg rear wall membrane wall tube screen 18, the right return leg inner wall membrane wall tube screen 34, and the right return leg outer wall membrane wall tube screen 20 to form two return legs, one end of the two return legs is connected to the furnace, and the other end is connected to the return device to realize return.
[0058] A left return leg hanging structure 29 and a right return leg hanging structure 30 are provided on the membrane wall tube panel between the return leg inlet header and the return leg outlet header 35 to bear the load of the return leg section of the return device.
[0059] The return leg outlet header 35 and the return material device lower front wall header 23 are connected via a membrane wall tube screen 21 between the return leg outlet header and the return material device lower front wall header; the return leg outlet header 35 and the return material device lower rear wall header 24 are connected via a membrane wall tube screen 22 between the return leg outlet header and the return material device lower rear wall header.
[0060] A plurality of wind hoods are arranged on the membrane wall tube screen 22 between the return leg outlet header and the lower rear wall header of the return device. High-pressure fluidizing air fully fluidizes the high-temperature ash in the return device structure through each wind hood, and is sent into the furnace through the return device structure for circulating combustion.
[0061] The lower front wall header 23 of the return material device is connected to the return material device outlet header 27 by a membrane wall tube screen 25 between the lower front wall header of the return material device and the return material device outlet header; the lower rear wall header 24 of the return material device is connected to the return material device outlet header 27 by a membrane wall tube screen 26 between the lower rear wall header of the return material device and the return material device outlet header.
[0062] The membrane wall tube screen 33 on the inner wall of the left return leg, the membrane wall tube screen 34 on the inner wall of the right return leg, the membrane wall tube screen 25 between the lower front wall header of the return device and the return device outlet header, and the membrane wall tube screen 26 between the lower rear wall header of the return device and the return device outlet header, form a return channel shape and are finally all connected to the return device outlet header 27.
[0063] The return material outlet header 27 is connected to the cyclone separator, and the return material outlet header 27 and the cyclone separator are connected by a lower vertical section membrane wall tube screen 28 of the separator. The lower vertical section membrane wall tube screen 28 of the separator is connected to the cyclone separator above it, and a cyclone separator outlet annular header 31 is arranged on the top of the cyclone separator, and a certain number of cyclone separator outlet annular header hanging structures 32 are arranged on the cyclone separator outlet annular header 31 to bear the load of the cyclone separator itself and the load of the return material descending section. The cyclone separator outlet flue is connected to the tail flue through a flue expansion joint.
[0064] At the same time, the plane where the rigid suspension is located is used as the expansion zero point of the cyclone separator in the vertical direction. During the operation of the boiler, the cyclone separator outlet flue expands upward, and the cyclone separator and the return device expand downward, thus avoiding the bending of the upper suspension of the separator and the occurrence of such safety hazards.
[0065] In this embodiment, the two return legs are connected to the return device at right angles, so that the steam-cooled return device is smaller in size, more compact in structure, uses less pipes and refractory materials, has a smaller load, and is more convenient to arrange.
[0066] The compact double-leg steam-cooled return material device structure described in the utility model has a steam flow as follows when used:
[0067] After the steam enters the left return leg inlet header 13 and the right return leg inlet header 14 through multiple return leg inlet connecting pipes 11, it is divided into multiple paths and enters the return leg outlet header 35 and the return device outlet header 27 respectively through the membrane wall tube screens: one part of the steam enters the return leg outlet header 35 through the left return leg front wall membrane wall tube screen 15, the right return leg front wall membrane wall tube screen 16, the left return leg rear wall membrane wall tube screen 17, the right return leg rear wall membrane wall tube screen 18, the left return leg outer wall membrane wall tube screen 19, and the right return leg outer wall membrane wall tube screen 20, and the other part of the steam enters the return device outlet header 27 through the left return leg inner wall membrane wall tube screen 33 and the right return leg inner wall membrane wall tube screen 34. After the steam comes out of the return leg outlet header 35, it is divided into two parts: one part of the steam passes through the return leg outlet header to the membrane wall tube screen 21 between the lower front wall header of the return material device and enters the lower front wall header 23 of the return material device, and then the steam passes through the lower front wall header of the return material device to the membrane wall tube screen 25 between the return material device outlet header, and finally enters the return material device outlet header 27; the other part of the steam passes through the return leg outlet header to the membrane wall tube screen 22 between the lower rear wall header of the return material device and enters the lower rear wall header 24 of the return material device, and then the steam passes through the lower rear wall header of the return material device to the membrane wall tube screen 26 between the return material device outlet header, and finally enters the return material device outlet header 27.
[0068] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.
Claims
1. A compact double-leg steam-cooled return feeder structure, characterized in that: It includes a return leg inlet header, a return leg outlet header, a return device lower header and a return device outlet header. Membrane wall tube screens are arranged between the return leg inlet header and the return leg outlet header, between the return leg inlet header and the return device outlet header, between the return leg outlet header and the return device lower header, and between the return device lower header and the return device outlet header. The return leg inlet header, the return leg outlet header, the return device lower header, the return device outlet header and each of the membrane wall tube screens together form a return channel. The return leg inlet header comprises a left return leg inlet header and a right return leg inlet header, the left return leg inlet header and the right return leg inlet header respectively correspond to a return port of the furnace of the circulating fluidized bed boiler, and the left return leg inlet header and the right return leg inlet header are respectively connected to the furnace through a return leg expansion joint; The reclaimer outlet header is connected to a cyclone separator.
2. The compact double-leg steam-cooled material return device structure according to claim 1 is characterized in that: The left-side return leg inlet header and the right-side return leg inlet header are both connected to a plurality of return device inlet connecting pipes.
3. The compact double-leg steam-cooled material return device structure according to claim 1 is characterized in that: The left side return leg front wall membrane type wall tube screen, the right side return leg front wall membrane type wall tube screen, the left side return leg rear wall membrane type wall tube screen, the right side return leg rear wall membrane type wall tube screen, the left side return leg outer wall membrane type wall tube screen, and the right side return leg outer wall membrane type wall tube screen are connected between the return leg inlet header and the return leg outlet header; The inner wall membrane type wall tube panel of the left return leg and the inner wall membrane type wall tube panel of the right return leg are connected between the return leg inlet header and the return device outlet header.
4. The compact double-leg steam-cooled material return device structure according to claim 1 is characterized in that: The membrane wall tube panel between the return leg inlet header and the return leg outlet header is vertically connected to the return leg outlet header.
5. The compact double-leg steam-cooled material return device structure according to claim 1 is characterized in that: A left-side return leg hanging structure and a right-side return leg hanging structure are provided on the membrane wall tube panel between the return leg inlet header and the return leg outlet header.
6. The compact double-leg steam-cooled material return device structure according to claim 1 is characterized in that: The lower header of the return material device includes a lower rear wall header of the return material device and a lower front wall header of the return material device; The return leg outlet header and the lower front wall header of the return material device are connected by a membrane wall tube screen from the return leg outlet header to the lower front wall header of the return material device; the return leg outlet header and the lower rear wall header of the return material device are connected by a membrane wall tube screen from the return leg outlet header to the lower rear wall header of the return material device.
7. The compact double-leg steam-cooled material return device structure according to claim 6 is characterized in that: A plurality of hoods are arranged on the membrane wall tube screen between the return leg outlet header and the lower rear wall header of the return device.
8. The compact double-leg steam-cooled material return device structure according to claim 6 is characterized in that: The lower front wall header of the return material device is connected to the return material device outlet header by a membrane wall tube screen from the lower front wall header of the return material device to the return material device outlet header; the lower rear wall header of the return material device is connected to the return material device outlet header by a membrane wall tube screen from the lower rear wall header of the return material device to the return material device outlet header.
9. The compact double-leg steam-cooled material return device structure according to claim 1 is characterized in that: The return device outlet header and the cyclone separator are connected by a vertical membrane wall tube screen at the lower part of the separator.
10. The compact double-leg steam-cooled material return device structure according to claim 9, characterized in that: A cyclone separator outlet annular header is arranged on the top of the cyclone separator, and a cyclone separator outlet annular header hanging structure is arranged on the cyclone separator outlet annular header.
Citation Information
Patent Citations
Steam-cooled material returning device structure
CN216131917U