Arrangement structure of coal bunker in CFB boiler steel frame
By arranging the front and side coal bunkers within the steel frame of the CFB boiler, eliminating the need for a separate coal bunker frame, and using an electronic weighing coal feeder connected to the front and rear walls of the boiler, the problems of unstable operation and high maintenance costs of existing CFB boilers have been solved, achieving more efficient coal feeding uniformity and rapid load change capability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI BOILER WORKS CO LTD
- Filing Date
- 2025-03-03
- Publication Date
- 2026-04-10
AI Technical Summary
The existing coal bunker layout of CFB boilers leads to unstable boiler operation, high maintenance costs, and difficulty in meeting the operational requirements of rapid load changes. In particular, when burning low-quality fuels, the amount of coal required to be fed into the boiler is large, and long-distance transportation affects the stability and economic benefits of the boiler.
The coal bunker is arranged inside the boiler steel frame, using a front coal bunker and two side coal bunkers, eliminating the need for a separate coal bunker steel frame. An electronic weighing coal feeder is connected to the front and rear walls of the boiler, reducing the need for scraper feeders, shortening the conveying path, and achieving joint coal feeding from the front and rear walls.
It improves the stability and variable load response speed of the boiler, reduces maintenance costs, enhances the uniformity of coal feeding and the adaptability of coal quality, and is particularly suitable for low-calorific-value fuels such as coal gangue, avoiding coal blockage and wear problems in the coal chute.
Smart Images
Figure CN224108185U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a steel frame inner coal bunker arrangement structure suitable for large circulating fluidized bed boiler. BACKGROUND
[0002] At present, the common coal bunker arrangement of existing CFB boiler is front coal bunker, and the coal bunker steel frame is relatively independent with the boiler steel frame, and the two are not connected through the steel frame.
[0003] As shown in Figure 1 , Figure 2 , a CFB boiler coal bunker arrangement structure, the steel frame is set as 0-1, the coal bunker steel frame is set as 0-2, wherein the coal bunker steel frame is arranged in front of the boiler steel frame. The coal bunker is arranged in the coal bunker steel frame 0-2, as shown in Figure 1 , Figure 2 , the number of coal bunkers is set as 5, which are respectively set as coal bunker A-coal bunker E. Among them, the coal bunker A and the coal bunker E are arranged at both ends of the coal bunker, which are set as side coal bunker structures and are connected with the rear wall of the boiler. The coal bunker B-coal bunker D is arranged at the middle position of the coal bunker, which is set as a front coal bunker structure and is connected with the front wall of the boiler.
[0004] Two return leg coal feeding mechanisms are arranged in the coal bunker A and the coal bunker E, respectively, and the maximum single return leg coal feeding capacity is 80t / h. Two wall type coal feeding mechanisms are arranged in the coal bunker B-coal bunker D, respectively, and the maximum single wall type coal feeding capacity is 35t / h. The boiler design adopts 6 wall type coal feeding mechanisms in the front wall + 4 return leg coal feeding mechanisms in the rear wall, therefore, the total maximum coal feeding capacity is 530t / h, which can meet the 200% design coal feeding amount (BMCR working condition 268t / h requirement).
[0005] The two return leg coal feeding mechanisms in the coal bunker A and the coal bunker E are respectively composed of an electronic weighing coal feeder 0-4 and a scraper feeder 0-6.
[0006] The two wall type coal feeding mechanisms in the coal bunker B-coal bunker D are respectively composed of an electronic weighing coal feeder 0-5.
[0007] The boiler 0-3 is arranged in the boiler steel frame 0-1, wherein the coal bunker A and the coal bunker E are connected with the rear wall of the boiler through the electronic weighing coal feeder 0-4 and the scraper feeder 0-6. The length of the electronic weighing coal feeder 0-4 in the coal bunker A and the coal bunker E is set as L1, and the value range is set as 25-40 meters.
[0008] The boiler 0-3 is arranged in the boiler steel frame 0-1, wherein the coal bunker B-coal bunker D is connected with the front wall of the boiler through the electronic weighing coal feeder 0-5.
[0009] The prior art has the following problems: the coal bunker is placed on the support structure between the steam engine room and the boiler room; the front and rear walls are combined to feed coal; when inferior fuel is used, the amount of coal required for the furnace is large, and the front and rear walls are combined to feed coal; the coal bunker arranged on both sides of the front wall will feed the fuel into the corresponding coal feeding point of the rear wall through the long distance electronic weighing coal feeder + scraper; the unloading capacity of the coal bunker, the transportation speed of the electronic weighing coal feeder and the uniformity of the material distribution of the scraper will affect the operation stability and the variable load response speed of the boiler; the maintenance cost is high and the economic benefit is low. Practical new type content
[0010] The utility model provides a CFB boiler steel frame inner coal bunker arrangement structure, and the coal bunker arrangement adopts boiler front coal bunker + boiler rear two sides coal bunker arrangement, and the front coal bunker and both sides coal bunker are arranged in the boiler steel frame (1-1), the independent coal bunker free steel frame is not arranged in the boiler steel frame (1-1), and the coal bunker is directly integrated in the boiler steel frame, the boiler (1-3) is arranged in the middle part of the boiler steel frame (1-1), four front coal bunkers are arranged at the front position of the boiler (1-3), and the coal bunker numbers are respectively first to fourth coal bunkers (1#~4#); one side coal bunker is arranged at the position of the rear part of the boiler (1-3) on both sides respectively, and the coal bunker numbers are respectively fifth to sixth coal bunkers (5#, 6#).
[0011] Preferably, two return legs coal feeding mechanisms are arranged in the first to fourth coal bunkers (1#~4#) respectively, and the maximum single return leg coal feeding capacity is 80t / h; four return legs coal feeding mechanisms are arranged in the fifth to sixth coal bunkers (5#, 6#) respectively, and the maximum return leg coal feeding capacity is 80t / h; the boiler design adopts eight front wall return leg coal feeding + eight rear wall return leg coal feeding, therefore, the total maximum coal feeding capacity is 1280t / h, and the 200% design coal feeding amount can be met.
[0012] Preferably, the eight return leg coal feeding mechanisms in the first to fourth coal bunkers 1#~4# are respectively composed of second electronic weighing coal feeders (1-5); the eight return leg coal feeding mechanisms in the fifth to sixth coal bunkers 5#, 6# are respectively composed of first electronic weighing coal feeders (1-4).
[0013] Preferably, the fifth to sixth coal bunkers (5#, 6#) are connected with the boiler rear wall through the first electronic weighing coal feeder (1-4); the length of the first electronic weighing coal feeder (1-4) in the fifth to sixth coal bunkers (5#, 6#) is L2, and the value range is 5~8 meters; the boiler (1-3) is arranged in the boiler steel frame (1-1), and the first to fourth coal bunkers (1#~4#) are connected with the boiler front wall through the second electronic weighing coal feeder (1-5).
[0014] The utility model discloses the following beneficial effects compared with the prior art: the utility model discloses a kind of boiler steel frame inner coal bunker arrangement structure, coal bunker arrangement adopts front coal bunker+two side coal bunker arrangement, using this arrangement mode, front coal bunker and side coal bunker are all arranged in boiler steel frame, without extra erection support structure, land area is saved. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 Main view of existing CFB boiler conventional coal bunker arrangement.
[0016] Figure 2 Plan view of existing CFB boiler conventional coal bunker arrangement.
[0017] Figure 3 Main view of a new CFB boiler steel frame inner coal bunker arrangement.
[0018] Figure 4 Plan view of a new CFB boiler steel frame inner coal bunker arrangement.
[0019] Figure 5 A new CFB boiler return material device.
[0020] Reference signs: boiler steel frame 1-1, boiler 1-3, first electronic weighing coal feeder 1-4, second electronic weighing coal feeder 1-5, first to fourth coal bunker 1#~4#, fifth to sixth coal bunker 5#, 6#. DETAILED DESCRIPTION
[0021] The utility model will be further explained in detail in combination with drawings and specific embodiments, but the utility model is not limited to the following embodiments.
[0022] A kind of CFB boiler steel frame inner coal bunker arrangement structure, coal bunker arrangement adopts front coal bunker+two side coal bunker arrangement, and front coal bunker and two side coal bunkers are all arranged in boiler steel frame (see Figure 3 、 Figure 4 ).
[0023] Boiler steel frame is set to 1-1, and there is no coal bunker steel frame in boiler, wherein, in the middle of boiler steel frame 1-1, boiler 1-3 is equipped, in the embodiment (see Figure 3 、 Figure 4 ), four front coal bunkers are equipped in the front position of boiler 1-3, and coal bunker number is respectively set as first to fourth coal bunker 1#~4#. One side coal bunker is respectively equipped in the position of the back of boiler 1-3, and coal bunker number is respectively set as fifth to sixth coal bunker 5#, 6#.
[0024] The first to fourth coal bunkers 1#~4# are respectively provided with two return material leg coal feeding mechanisms, and the single return material leg coal feeding capacity is 80t / h.
[0025] The eight return material leg coal feeding mechanisms in the first to fourth coal bunkers 1#~4# are all composed of the second electronic weighing coal feeder 1-5.
[0026] The eight return material leg coal feeding mechanisms in the fifth to sixth coal bunkers 5# and 6# are all composed of the first electronic weighing coal feeder 1-4, and the scraper feeding mechanism is omitted.
[0027] The boiler 1-3 is arranged in the boiler steel frame 1-1, wherein the fifth to sixth coal bunkers 5# and 6# are connected with the rear wall of the boiler through the first electronic weighing coal feeder 1-4.
[0028] The boiler 1-3 is arranged in the boiler steel frame 1-1, wherein the first to fourth coal bunkers 1#~4# are connected with the front wall of the boiler through the second electronic weighing coal feeder 1-5.
[0029] The utility model discloses a kind of coal bunker arrangement structures in boiler steel frame, coal bunker arrangement adopts front coal bunker+two side coal bunker arrangement, using this arrangement mode, front coal bunker and side coal bunker are arranged in boiler steel frame, and additional support structure is not needed, and land area is saved.
[0030] The utility model discloses a kind of coal bunker arrangement structures in boiler steel frame, two side coal bunkers, i.e. the first electronic weighing coal feeder 1-4 in the fifth to sixth coal bunkers 5# and 6#, length L2, compared with the CFB boiler of previous coal bunker arrangement, electronic weighing coal feeder length L1, L2 length is one fifth of L1 length, mechanism length realizes reduction, improve the stability of boiler and variable load response speed, low in later maintenance cost, high economic benefit. The front coal bunker and side coal bunker in the utility model all adopt single-stage electronic weighing conveying mode of scraper feeder being omitted, overall coal conveying path length tends to be consistent, more suitable for the demand of boiler fast variable load operation. Combined coal bunker design, the coal of whole bed surface all tends to be uniform, so that boiler operation is more stable.
[0031] The utility model discloses a new CFB boiler steel frame inner coal bunker arrangement structure, and the coal bunker arrangement adopts front coal bunker+both sides coal bunker arrangement, and the coal feeding system is designed with 8 material return devices, so 16 coal feeding ports can be arranged, the coal feeding uniformity of the boiler and the coal quality adaptability are improved, and the utility model is especially suitable for low heat value fuel of coal gangue blending combustion.
[0032] Figure 5 It is a new CFB boiler material return device diagram, and the material return device number in the diagram is set as 1-6-1#~1-6-8# (total 8), and the coal feeding port number in the diagram is set as 1-7-1#~1-7-16# (total 16).
[0033] For the selection of the coal feeding system of the large circulating fluidized bed boiler, the engineering coal condition and the geographical condition where the engineering is located need to be determined, for the fuel of low heat value, the boiler fuel consumption is large, and for the CFB boiler above 300MW, the hearth width is wide, the number of each hearth coal feeding port is large, and in the actual operation process, due to various factors, the fuel amount of each coal feeding port is very large, in order to reduce the influence of coal feeding on the hearth combustion, the front and rear wall combined feeding is adopted, that is, the coal bunker arrangement adopts front coal bunker+both sides coal bunker arrangement, the first to fourth coal bunkers 1#~4# are connected with the front wall of the boiler through the electronic weighing coal feeder, and the front wall feeding function of the boiler is realized.
[0034] In addition, the front and rear wall combined feeding is favorable to improving the uniformity of the hearth, and the rear wall feeding (material return device feeding) can completely avoid the coal blocking phenomenon of the front wall coal falling pipe in the high humidity area.
[0035] The new CFB boiler disclosed by the utility model innovatively adopts the front and rear wall combined feeding design structure in the coal feeding mode, and the front and rear wall feeding mode also adopts the material return device feeding, so as to improve the reliability and stability of the coal feeding system.
[0036] 1, coal feeding and circulating material are mixed in the material return device in advance, and then enter the hearth, so that the hearth combustion temperature is more uniform;
[0037] 2. The flow rate of circulating material in each return feeder is much greater than the coal feed rate. Therefore, the coal feed rate of a single return feeder can be much greater than that of a conventional wall-type coal feeder. Thus, the coal feed rate of a single return feeder can be greater than that of a conventional wall-type coal feeder while ensuring the uniformity of bed temperature.
[0038] 3. The coal return feeder can prevent coal blockage in the feed pipe. Since the coal return pipe of the coal return feeder is basically arranged in a straight pipe, it can reduce or even eliminate the occurrence of coal blockage.
[0039] 4. It can reduce or even eliminate the wear of the coal chute. For wall-type coal feeders, the wear of the coal chute is very serious due to the design of the bend. The wear is especially serious for power plants that burn coal gangue. Therefore, wall-type coal feeders are not recommended in the design of ultra-supercritical CFB boilers.
[0040] 5. The coal feeding method for the front and rear walls adopts a return feeder, which can be used for various coal bunker layout structures and is easy to arrange.
[0041] For large-capacity, ultra-supercritical circulating fluidized bed boilers, fuel consumption is increased, and a combined front and rear wall coal feeding method is usually adopted to meet operational needs. Furthermore, the furnace width is wider, and the arrangement of a single front wall or single-side coal bunker will result in long transport routes and slow response times. Current policies require generating units to have deep peak-shaving and rapid load-changing capabilities, necessitating a simpler coal bunker arrangement with shorter transport routes.
[0042] This utility model discloses a coal bunker arrangement structure within a boiler steel frame. The length L2 of the electronic weighing feeders in both coal bunkers is reduced by one-fifth compared to the previous CFB boiler coal bunker arrangement structure, where the length L1 of the electronic weighing feeders is reduced from the conventional 25-40 meters to 5-8 meters, a reduction of approximately 80%. This simplified structure improves boiler stability and load change response speed, resulting in lower maintenance costs and higher economic benefits. The front and side coal bunkers in this utility model employ a single-stage electronic weighing conveying method that eliminates the need for scraper feeders, leading to a more consistent overall coal conveying path length, which is more suitable for the boiler's rapid load change operation requirements. The combined coal bunker design ensures uniform coal feeding across the entire bed surface, resulting in more stable boiler operation.
[0043] The above description is a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model. These improvements and modifications are also considered to be within the protection scope of the present utility model, and the protection scope of the present utility model shall be defined by the claims.
Claims
1. A CFB boiler steel frame internal coal bunker arrangement, characterized in that, The coal bunker arrangement adopts a boiler front coal bunker + boiler rear two-side coal bunker arrangement, and the front coal bunker and the two-side coal bunkers are arranged in the boiler steel frame (1-1); The boiler steel frame (1-1) is not provided with an independent coal-free steel frame, and the coal bunkers are directly integrated in the boiler steel frame, a boiler (1-3) is arranged in the middle of the boiler steel frame (1-1), four front coal bunkers are arranged in front of the boiler (1-3), and the coal bunkers are numbered as the first to fourth coal bunkers (1#-4#); one side coal bunker is arranged at each of the two sides of the rear part of the boiler (1-3), and the coal bunkers are numbered as the fifth to sixth coal bunkers (5#, 6#).
2. The coal bunker arrangement structure in the CFB boiler steel frame according to claim 1, characterized in that: Two return-leg coal feeding mechanisms are arranged in each of the first to fourth coal bunkers (1#-4#), and the maximum single return-leg coal feeding capacity is 80 t / h; Four return-leg coal feeding mechanisms are arranged in each of the fifth to sixth coal bunkers (5#, 6#), and the maximum return-leg coal feeding capacity is 80 t / h; the boiler design adopts 8 front-wall return-leg coal feeding mechanisms + 8 rear-wall return-leg coal feeding mechanisms, so that the total maximum coal feeding capacity is 1280 t / h, which can meet the 200% design coal feeding amount.
3. The coal bunker arrangement structure in the CFB boiler steel frame according to claim 2, characterized in that: The eight return-leg coal feeding mechanisms in the first to fourth coal bunkers (1#-4#) are each composed of a second electronic weighing coal feeder (1-5); The eight return-leg coal feeding mechanisms in the fifth to sixth coal bunkers (5#, 6#) are each composed of a first electronic weighing coal feeder (1-4).
4. The coal bunker arrangement structure in the CFB boiler steel frame according to claim 3, characterized in that: The fifth to sixth coal bunkers (5#, 6#) are connected with the rear wall of the boiler through the first electronic weighing coal feeder (1-4); the length of the first electronic weighing coal feeder (1-4) in the fifth to sixth coal bunkers (5#, 6#) is L2, and the value range of L2 is 5-8 meters; The boiler (1-3) is arranged in the boiler steel frame (1-1), and the first to fourth coal bunkers (1#-4#) are connected with the front wall of the boiler through the second electronic weighing coal feeder (1-5).