Uniform powder supply mixing mill powder making system
By combining a double-inlet double-outlet coal mill and a medium-speed coal mill, and utilizing components such as isolation plates and exhaust gas separators, the problems of output delay and coal powder uniformity in the medium-speed pulverizing system during load increase were solved, achieving uniform coal powder distribution and efficient combustion, and improving the boiler's load regulation speed and operational stability.
Patent Information
- Application Number
- CN202423216352.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-12-25
AI Technical Summary
Medium-speed grinding systems experience output delays when increasing load, which limits the boiler's load increase rate and results in poor uniformity of the pulverized coal feeding pipeline. In particular, the air-coal ratio increases at low loads, which is not conducive to stable boiler combustion. Furthermore, conventional pulverized coal feeding pipelines are prone to wear.
It adopts a combination of double-inlet double-outlet coal mill and medium-speed coal mill, combined with isolation plates, exhaust gas separators and gate valves, to adjust the air-coal ratio and coal powder fineness of the coal feeding pipeline, separate excess air through the exhaust gas separator, and precisely control the airflow using regulating valves and flow measurement devices, combined with the mixed utilization of multiple coal types.
It achieves uniform distribution and efficient combustion of pulverized coal, improves the load regulation speed and operational stability of the boiler, reduces wear on pulverized coal feeding pipes, and enhances the flexibility and reliability of the system.
Smart Images
Figure CN223595967U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a new generation of coal power field of thermal power plant, especially a kind of uniform powder supply mixed grinding system. BACKGROUND
[0002] Variable load rate is one of the core requirements of new generation of coal power.And many thermal power plants use medium-speed mill direct-fired pulverizing system, medium-speed mill has low cost and low operating cost, but due to its own grinding output characteristics, when the coal supply of first coal feeder increases, there is a certain delay in the increase of its output, the delay of medium-speed mill output will limit the boiler load increasing rate, thereby affecting the unit load increasing rate;Double-in double-out mill has high load increasing rate, but its cost is high, and the operating cost is high, so many thermal power plants only use double-in double-out steel ball mill when coal quality is very poor.
[0003] Due to the arrangement of the burner, the length of the powder conveying pipe from the coal mill is very different, and the resistance is also very different, but for the boiler burner, the more uniform the air-powder volume is, the better, the adjustable orifice is arranged on the conventional powder conveying pipe, and the adjustable orifice is used to adjust the uniformity of the powder conveying pipe, but the adjustable orifice is easily worn out because the powder conveying pipe long-term conveys the wear-resistant air-powder mixture, which leads to poor uniformity of the powder conveying pipe in long-term operation, especially in the low load stage of deep regulation, the air-coal ratio is high, and the uniformity is worse.Deep regulation is also a core requirement of new generation of coal power, and in the low load stage, the air-coal ratio of conventional coal mill becomes larger, which is not conducive to stable combustion of boiler. SUMMARY
[0004] To solve the existing problems, the utility model provides a kind of uniform powder supply mixed grinding system, which aims to combine multiple different types of coal mills, and mix different coal species;At the same time, by using the isolation plate and the exhaust gas separator, the load supply range and the air-coal ratio of deep regulation powder supply are increased to improve the combustion efficiency of pulverized coal and the operating stability of boiler.
[0005] To achieve the above purpose, the utility model provides the following technical scheme.
[0006] A kind of uniform powder supply mixed grinding system, including double-in double-out mill unit, first powder conveying pipe, medium-speed mill unit, second powder conveying pipe, first separator, first plug door, exhaust gas separator, second separator and second plug door;The double-in double-out mill unit is sequentially connected with the hearth of boiler by first separator, a plurality of first powder conveying pipes, first plug door and exhaust gas separator are arranged on each first powder conveying pipe;The medium-speed mill unit is sequentially connected with the hearth of boiler by second separator, a plurality of second powder conveying pipes, and second plug door is arranged on each second powder conveying pipe;Isolation plate is arranged in the first powder conveying pipe.
[0007] As a further improvement of the present application, the isolation plate is inclined to the direction of the pipeline, and is used for blocking and shielding the pulverized coal in the pipeline.
[0008] As a further improvement of the present application, the inclination of the isolation plate is adjustable.
[0009] As a further improvement of the present application, the first pulverized coal pipeline comprises a vertical section perpendicular to the ground, and a gas separation device is arranged on the vertical section.
[0010] As a further improvement of the present application, the gas separation device comprises a gas pipe.
[0011] As a further improvement of the present application, the gas separation device further comprises a regulating valve, a flow measuring device and a shut-off valve arranged in sequence on the gas pipe.
[0012] As a further improvement of the present application, the double-in double-out coal mill unit comprises a first raw coal bin, a first coal feeder and a double-in double-out coal mill, and two openings arranged at the lower part of the first raw coal bin are connected to two inlets arranged on the double-in double-out coal mill through the first coal feeder.
[0013] As a further improvement of the present application, the number of the double-in double-out coal mill is single or multiple.
[0014] As a further improvement of the present application, the medium-speed coal mill unit comprises a second raw coal bin, a second coal feeder and a medium-speed coal mill, and an opening arranged at the lower part of the second raw coal bin is connected to an inlet arranged on the medium-speed coal mill through the second coal feeder.
[0015] As a further improvement of the present application, the number of the medium-speed coal mill is single or multiple.
[0016] The present application has the following advantages:
[0017] The present application combines multiple coal mills of different types, mixes different coal types, and adjusts the opening and closing of multiple pulverized coal pipelines through the plug door, so that the ratio and fineness of the pulverized coal entering the boiler are uniform, thereby improving the combustion efficiency of the pulverized coal and improving the load and operation stability of the boiler in a timely and rapid manner.
[0018] Preferably, the isolation plate can change the flow state of the pulverized coal gas flow in the pulverized coal pipeline, increase the air-coal ratio, and help to realize uniform distribution of the pulverized coal and reduce pipeline wear. At the same time, the inclined isolation plate can also play a certain flow guiding role, thereby improving the conveying efficiency of the pulverized coal.
[0019] Preferably, the adjustable inclination allows the isolation plate to be adjusted according to different operating conditions, thereby optimizing the flow state of the pulverized coal gas flow and further improving the combustion efficiency of the pulverized coal and the operating stability of the boiler.
[0020] Preferably, the provision of the exhaust gas separator helps to separate excess air from the pulverized coal gas flow, thereby reducing the air-coal ratio and improving the combustion efficiency.
[0021] Preferably, the exhaust gas pipe, as part of the exhaust gas separator, is responsible for guiding the separated exhaust gas out of the system, ensuring that the air content in the pulverized coal gas flow is moderate, which is conducive to the stable combustion of the pulverized coal.
[0022] Preferably, the regulating valve can adjust the flow rate of the gas flow in the exhaust gas pipe as needed, thereby achieving precise control of the air content in the pulverized coal gas flow, which helps to improve the combustion efficiency of the pulverized coal and the operating stability of the boiler; the flow measuring device can monitor the flow rate of the gas flow in the exhaust gas pipe in real time, providing accurate operating data for the system, which helps operators to adjust the system operating parameters in a timely manner to ensure stable supply of pulverized coal and combustion efficiency; the provision of the shut-off valve allows operators to quickly shut off the gas flow in the exhaust gas pipe when needed, ensuring the safe operation of the system. At the same time, it also helps to isolate the exhaust gas separator part during maintenance or repair, facilitating maintenance work.
[0023] Optionally, the double-in double-out coal mill unit realizes continuous supply and grinding of the pulverized coal, ensuring the uniformity and stability of the pulverized coal. At the same time, the double-in double-out coal mill has the advantages of high grinding efficiency and stable operation.
[0024] Preferably, the choice of single or multiple double-in double-out coal mills can flexibly adjust the coal grinding capacity of the system. Multiple double-in double-out coal mills can also realize load balancing and mutual backup, improving the overall performance and reliability of the system.
[0025] Optionally, the design of the medium-speed coal mill unit allows the system to select different types of coal mills as needed to adapt to different coal types and operating conditions. This flexibility helps to improve the adaptability and reliability of the system.
[0026] Preferably, the choice of single or multiple medium-speed coal mills according to actual needs can flexibly adjust the coal grinding capacity of the system, ensuring stable supply of the pulverized coal. At the same time, multiple medium-speed coal mills can also realize mutual backup, improving the reliability and stability of the system. BRIEF DESCRIPTION OF DRAWINGS
[0027] The drawings described herein are for illustrative purposes only and do not in any way limit the scope of the present disclosure. In addition, the shapes and proportions of the components in the drawings are only illustrative and are used to help understand the present invention, and are not specific limitations on the shapes and proportions of the components. In the drawings:
[0028] Figure 1 A schematic diagram of a uniform-portion mixed grinding pulverizing system according to an embodiment;
[0029] Figure 2 A schematic diagram of a waste gas separator of a uniform-portion mixed grinding pulverizing system according to an embodiment;
[0030] Wherein, 1, a first raw coal bin; 2, a first coal feeder; 3, a double-in double-out coal mill; 4, a first separator; 5, a first plug door; 6, a first powder conveying pipeline; 7, a waste gas separator; 8, a second raw coal bin; 9, a second coal feeder; 10, a medium-speed coal mill; 11, a second separator; 12, a second powder conveying pipeline; 13, a second plug door; 14, a boiler; 15, an isolation plate; 16, a waste gas pipe; 17, a regulating valve; 18, a flow measuring device; 19, a shut-off valve. DETAILED DESCRIPTION
[0031] In order to make the personnel in the technical field better understand the technical scheme in the utility model, the technical scheme in the embodiment of the utility model will be described clearly and completely below in combination with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by the personnel in the technical field without making creative labor should belong to the protection scope of the utility model.
[0032] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can be intervening elements. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can be present. The terms "vertical", "horizontal", "left", "right", and the like as used herein are used for illustration only and do not in any way limit the embodiments of the present application.
[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this description, the terms "and / or" includes any and all combinations of one or more of the associated listed items.
[0034] Embodiment 1
[0035] As Figure 1The uniform coal feeding and mixing grinding system shown includes a double-inlet double-outlet coal mill unit, a first coal feeding pipe 6, a medium-speed coal mill unit, a second coal feeding pipe 12, a first separator 4, a first gate valve 5, a waste gas separator 7, a second separator 11, and a second gate valve 13. The double-inlet double-outlet coal mill unit 3 is connected to the furnace of a boiler 14 in sequence through the first separator 4 and several first coal feeding pipes 6. Each first coal feeding pipe 6 is equipped with a first gate valve 5 and a waste gas separator 7. The medium-speed coal mill unit 10 is connected to the furnace of a boiler 14 in sequence through the second separator 11 and several second coal feeding pipes 12. Each second coal feeding pipe 12 is equipped with a second gate valve 13.
[0036] The dual-inlet dual-outlet coal mill unit includes a first raw coal bunker 1, a first coal feeder 2, and a dual-inlet dual-outlet coal mill 3; the two openings at the bottom of the first raw coal bunker 1 are connected to the two inlets on the dual-inlet dual-outlet coal mill 3 through the first coal feeder 2.
[0037] The medium-speed coal mill unit includes a second raw coal bunker 8, a second coal feeder 9, and a medium-speed coal mill 10; the opening at the bottom of the second raw coal bunker 8 is connected to the inlet on the medium-speed coal mill 10 through the second coal feeder 9.
[0038] The advantages of changing a standalone medium-speed mill direct-fired or double-inlet double-outlet pulverizing system into a uniform pulverizing system that simultaneously includes a double-inlet double-outlet coal mill 3 and a medium-speed coal mill 10 are as follows: the double-inlet double-outlet mill drum contains a large amount of pulverized coal, and when the load needs to be increased, the output of both the double-inlet double-outlet mill and the medium-speed mill can be adjusted simultaneously to quickly and timely meet the grid demand for the load increase rate of boiler 14; when the output of the medium-speed mill is increased to the required output, the output of the double-inlet double-outlet mill is reduced to the set load level. During stable operation, the double-inlet double-outlet mill always has a certain margin and is not in a full-load state, which ensures that the load increase rate can be increased at any time and leaves a margin for changes in the pulverized coal supply of the system.
[0039] like Figure 2 As shown, an isolation plate 15 is installed inside the first pulverized coal feeding pipe 6. The isolation plate 15 is inclined in the direction of the pipe to block the pulverized coal inside the pipe and adjust the air-coal ratio inside the pipe. The isolation plate 15 is superior to the adjustable orifice in the mixing and grinding system. The adjustable orifice is easily worn, resulting in poor uniformity of the resistance of the pulverized coal feeding pipe during long-term operation, especially in the low-load stage of deep adjustment, where the uniformity requirement is even higher, and this problem is particularly prominent. At the same time, in order to eliminate the adjustable orifice, the design of the pulverized coal feeding pipe is also adjusted accordingly. The short pipe of about 20m uses a smaller inner diameter, while the long pipe of about 100m uses a larger inner diameter to ensure that the total resistance in each pulverized coal feeding pipe is consistent.
[0040] The first powder feeding pipeline 6 comprises a vertical pipeline section perpendicular to the ground. The exhaust gas separator is arranged on the vertical pipeline section, which helps to separate the exhaust gas and return the coal powder to the first powder feeding pipeline 6. The exhaust gas separator 7 is installed on the first powder feeding pipeline 6 in a low load state, which separates a part of the coal powder in the mixture of the exhaust gas and the coal powder, and discharges the coal powder to the boiler 14 through the exhaust gas pipeline 16, so as to ensure the reasonable allocation of the air-coal ratio at the low load burner, and help the boiler 14 to burn stably at a low load.
[0041] As shown in Figure 2 The exhaust gas separator 7 comprises an exhaust gas pipeline 16, an adjusting valve 17, a flow measuring device 18 and a shut-off valve 19 arranged in sequence on the exhaust gas pipeline 16. The adjusting valve 17 can adjust the flow of the gas in the exhaust gas pipeline 16 according to the needs, so as to realize the accurate control of the air content in the coal powder gas flow; this helps to improve the combustion efficiency of the coal powder and the operation stability of the boiler 14. The flow measuring device 18 can monitor the flow of the gas in the exhaust gas pipeline 16 in real time, and provide accurate operation data for the system, which helps the operator to adjust the system operation parameters in time, and ensures the stable supply of the coal powder and the combustion efficiency. The setting of the shut-off valve 19 enables the operator to quickly cut off the gas flow in the exhaust gas pipeline 16 when needed, so as to ensure the safe operation of the system; at the same time, it also helps to isolate the exhaust gas separator 7 part during maintenance or repair, and facilitates the maintenance work. When the coal powder supply of the double-in double-out coal mill 3 cannot meet the short-time load increase needs of the boiler 14, the shut-off valve 19 is opened, the exhaust gas is discharged from the first powder feeding pipeline 6, and the air-coal ratio is reduced; when the flow measuring device 18 shows that the exhaust gas flow is too large, the adjusting valve 17 can be used to finely adjust the exhaust gas, and the air-coal ratio is moderately increased.
[0042] Specific use principle:
[0043] When the load demand is not high and the coal type is fine, according to the load needs, fine coal powder is loaded in one or more second raw coal bins 8, and the second coal feeder 9 and the medium-speed coal mill 10 are opened respectively to supply the coal powder to the boiler 14;
[0044] When the load demand is high and the coal type is coarse, according to the load needs, coarse coal powder is loaded in one or more first raw coal bins 1, and the first coal feeder 2 and the double-in double-out coal mill 3 are opened respectively to supply the coal powder to the boiler 14;
[0045] When the load needs to be changed greatly and has different coal types, the fine coal powder is loaded in one or more second raw coal bins 8, the second coal feeder 9 and the medium-speed coal mill 10 are opened respectively to supply the coal powder to the boiler 14, the coarse coal powder is loaded in the first raw coal bin 1, the first coal feeder 2 and the double-in double-out coal mill 3 are opened to supply the coal powder to the boiler 14, the number of the pipeline for supplying the coal powder and the opening and closing degree are adjusted through the first plug door 5 arranged on the first coal powder conveying pipeline 6, the air-coal ratio of each first coal powder conveying pipeline 6 is further adjusted through the exhaust gas separator 7 arranged on each conveying branch pipeline, and the coal powder supply provided by the double-in double-out coal mill 3 for the load requirement of the boiler 14 is adjusted. The number of the pipeline for supplying the coal powder and the opening and closing degree are adjusted through the second plug door 13 arranged on the second coal powder conveying pipeline 12, and the coal powder supply provided by the medium-speed coal mill 10 for the load requirement of the boiler 14 is adjusted.
[0046] The above embodiment is only one of the implementation manners capable of realizing the technical scheme of the present application, and the scope of the present application is not limited to the above embodiment, but also includes any changes, substitutions and other implementation manners easily thought by those skilled in the art within the technical scope disclosed by the present application. Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.
Claims
1. A uniform powder supply mixed grinding powder system, characterized by, The application relates to a coal pulverizing system, which comprises a double-inlet double-outlet coal pulverizer unit, a first powder feeding pipeline (6), a medium-speed coal pulverizer unit, a second powder feeding pipeline (12), a first separator (4), a first plug door (5), a waste gas separator (7), a second separator (11) and a second plug door (13).
2. A uniform powder supply mixed grinding powder system according to claim 1, characterized in that, The double-inlet double-outlet coal pulverizer unit is sequentially connected with the furnace of a boiler (14) through the first separator (4) and a plurality of first powder feeding pipelines (6), and the first plug door (5) and the waste gas separator (7) are arranged on each first powder feeding pipeline (6); the medium-speed coal pulverizer unit is sequentially connected with the furnace of the boiler (14) through the second separator (11) and a plurality of second powder feeding pipelines (12), and the second plug door (13) is arranged on each second powder feeding pipeline (12); and the first powder feeding pipeline (6) is provided with a partition plate (15).
3. A uniform powder supply mixed grinding system according to claim 2, characterized in that, The partition plate (15) is inclined to the pipeline direction and is used for shielding the coal powder in the powder feeding pipeline.
4. A uniform powder supply mixed grinding system according to claim 3, wherein, The inclination of the partition plate (15) can be adjusted.
5. A uniform powder supply mixed grinding system according to claim 4, wherein, The first powder feeding pipeline (6) comprises a vertical section perpendicular to the ground, and the waste gas separator (7) is arranged on the vertical section.
6. A uniform powder supply mixed grinding system according to claim 4, wherein, The waste gas separator (7) comprises a waste gas pipeline (16) connected with the vertical section.
7. A uniform powder supply mixed grinding system according to claim 1, wherein, The waste gas separator (7) further comprises a regulating valve (17), a flow measuring device (18) and a shut-off valve (19) which are sequentially arranged on the waste gas pipeline (16).
8. A uniform powder supply mixed grinding system according to claim 7, characterized in that, The double-inlet double-outlet coal pulverizer unit comprises a first raw coal bin (1), a first coal feeder (2) and double-inlet double-outlet coal pulverizers (3), two openings arranged at the lower part of the first raw coal bin (1) are communicated with two inlets arranged on the double-inlet double-outlet coal pulverizers (3) through the first coal feeder (2).
9. The uniform powder supply mixed grinding powder system according to claim 1, characterized in that, The number of the double-inlet double-outlet coal pulverizers (3) is two or more.
10. A uniform powder supply mixed grinding system according to claim 9, wherein, The medium-speed coal pulverizer unit comprises a second raw coal bin (8), a second coal feeder (9) and a medium-speed coal pulverizer (10), and an opening arranged at the lower part of the second raw coal bin (8) is communicated with an inlet arranged on the medium-speed coal pulverizer (10) through the second coal feeder (9). The number of the medium-speed coal pulverizers (10) is single or multiple.