Boiler tail flue system suitable for full combustion of Zhundong coal
By using flue partition walls and coking removal devices in the boiler tail flue system, the problem of easy coking of Zhundong coal was solved, and flue gas temperature control and effective removal of coke were achieved, improving the economy and safety of boiler operation.
Patent Information
- Application Number
- CN202422656356.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-10-31
AI Technical Summary
Zhundong coal is prone to coking in boiler applications, which leads to reduced heat exchange efficiency of the heating surface and increased flue resistance. Existing methods, such as blending with kaolin, are costly and have not effectively solved the coking problem.
The flue is divided into a first flue, a connecting flue, and a second flue by a flue partition wall. Combined with a superheater cooling and decoking device, including an ash hopper, a slag crusher, a separator, a slag silo, and a hydraulic soot blowing assembly, the flue gas temperature is controlled below 950℃, and low-melting-point ash is adsorbed and decoked.
It effectively avoids coking on the heating surfaces of the low-temperature superheater and low-temperature reheater, reduces flue resistance, and improves energy utilization efficiency and the economy and safety of unit operation.
Smart Images
Figure CN223649335U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of coal -fired boiler, in particular to a kind of boiler tail flue system suitable for all burning Zhundong coal. BACKGROUND
[0002] Due to the unique coal quality characteristics of Zhundong coal, such as high water content and low ash melting point, it faces many technical challenges in practical application. The typical Zhundong coal ash melting point is between 1100-1200℃, which belongs to fusible ash, and is prone to coking. And its deformation temperature and softening temperature difference is small, about 30-60℃, which belongs to short slag coal, further aggravating the coking problem. These characteristics lead to serious coking in the boiler application of Zhundong coal in power plant, especially the coking of the tail flue heating surface, which reduces the heat exchange efficiency of the heating surface, and also increases the flue resistance, reducing the economy of the unit operation.
[0003] At present, in order to alleviate the problem of boiler coking, some enterprises that burn Zhundong coal usually adopt the method of mixing a large amount of kaolin, with a mixing ratio of 3%-8%. However, this alone increases the annual cost of the enterprise by hundreds of millions of yuan.
[0004] Therefore, to provide a boiler tail flue system suitable for all burning Zhundong coal to improve energy utilization efficiency and reduce system safety risk is an urgent problem to be solved by those skilled in the art. SUMMARY
[0005] The technical problem to be solved by the utility model is to overcome the defects in the prior art, thereby providing a boiler tail flue system suitable for all burning Zhundong coal.
[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme:
[0007] A boiler tail flue system suitable for all burning Zhundong coal, comprising:
[0008] A boiler outlet flue;
[0009] An empty flue connected to the boiler outlet flue;
[0010] A tail flue connected downstream of the empty flue, wherein a low-temperature superheater and a low-temperature reheater are provided in the tail flue;
[0011] A flue partition wall extending from the boiler outlet flue to the empty flue to divide the empty flue into a first flue, a second flue and a connecting flue; along the flow direction of flue gas, the first flue, the connecting flue and the second flue are sequentially connected;
[0012] A superheater is arranged on the side of the flue gas partition wall close to the second flue for reducing the temperature of the flue gas flowing in the first flue.
[0013] Preferably, the system further comprises a decoking device.
[0014] The decoking device comprises an ash hopper, a slag crusher, a separator, a slag reservoir and a water blowing assembly.
[0015] The ash hopper is arranged at the lower end of the connecting flue, and the ash hopper, the slag crusher, the separator and the slag reservoir are sequentially connected to form a slag discharge path.
[0016] The liquid output end of the separator is connected to the water blowing assembly, and the output end of the water blowing assembly is communicated with the first flue.
[0017] Preferably, a first valve is arranged between the ash hopper and the slag crusher.
[0018] Preferably, the water blowing assembly comprises a water pump, a water supplement pipe, a water delivery pipe and a plurality of water blowing devices.
[0019] The water supplement pipe is communicated with the input end of the water pump.
[0020] The water delivery pipe is sequentially communicated with the liquid output end of the separator, the water pump and the water blowing devices.
[0021] The output end of the water blowing devices is communicated with the first flue.
[0022] Preferably, a second valve is arranged between the water pump and the water blowing devices.
[0023] Preferably, the system further comprises an air preheater arranged downstream of the low-temperature reheater, and an air supply assembly is connected to the input end of the air preheater.
[0024] The system further comprises a heat exchanger having a first medium channel and a second medium channel, the first medium channel is communicated with the air supply assembly, and the second medium channel is communicated with the liquid output end of the separator and the water blowing assembly.
[0025] Preferably, the air supply assembly comprises a fan, a first pipeline and a second pipeline.
[0026] The first pipeline directly communicates the input end of the air preheater and the output end of the fan.
[0027] The second pipeline is communicated with the second medium channel and then communicated with the first pipeline.
[0028] Preferably, a third valve is arranged on the second pipeline.
[0029] Preferably, the boiler outlet flue is used to be connected with a pulverized coal furnace, or, used to be connected with a circulating fluidized bed power plant boiler.
[0030] Compared with the prior art, the utility model has the beneficial effects that:
[0031] The boiler tail flue system suitable for burning Zhundong coal entirely provided by the utility model can divide the empty flue into the first flue, the second flue and the connecting flue through the flue partition wall, and the first flue, the connecting flue and the second flue are communicated in sequence, so that the high-temperature flue gas output from the boiler outlet flue can first enter the first flue and be cooled down in the superheater heat exchange (heat transfer is realized through the flue partition wall), and then the flue gas temperature flowing through the first flue can be controlled below 950 DEG C, so that the ash melting point is not reached, and the low-melting-point ash in the flue gas can be attached to the side wall of the first flue and coked, thereby the ash content in the flue gas entering the tail flue can be reduced, and the problem of reduced heat exchange effect caused by coking of the heating surface of the low-temperature superheater and the low-temperature reheater can be avoided, and meanwhile, the problem of increased flue resistance caused by coking of the heating surface of the low-temperature superheater and the low-temperature reheater can also be avoided, and then the problems of economy and safety of the unit operation can be reduced. BRIEF DESCRIPTION OF DRAWINGS
[0032] In order to more clearly illustrate the specific embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description, and obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating labor.
[0033] Figure 1 An example of the connection schematic diagram provided by the utility model system.
[0034] EXPLANATION OF REFERENCE NUMERALS:
[0035] 101, first valve; 102, second valve; 103, third valve; 1, boiler outlet flue; 2, empty flue; 21, first flue; 22, second flue; 23, connecting flue; 3, tail flue; 31, low-temperature superheater; 32, low-temperature reheater; 4, flue partition wall; 5, superheater; 6, decoking device; 61, ash bucket; 62, slag crusher; 63, separator; 64, slag reservoir; 65, water blowing component; 651, water pump; 652, water supplement pipe; 653, water supply pipe; 654, water blowing device; 7, air preheater; 8, air supply component; 80, fan; 81, first pipeline; 82, second pipeline; 9, heat exchanger. DETAILED DESCRIPTION
[0036] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0037] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0038] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0039] See Figure 1 A boiler tail flue system suitable for burning only Zhundong coal includes a boiler outlet flue 1, an empty flue 2, a tail flue 3, a flue partition wall 4, and a superheater 5. The empty flue 2 is connected to the boiler outlet flue 1; the tail flue 3 is connected downstream of the empty flue 2 and contains a low-temperature superheater 31 and a low-temperature reheater 32; the flue partition wall 4 extends from the boiler outlet flue 1 to the empty flue 2, dividing the empty flue 2 into a first flue 21, a second flue 22, and a connecting flue 23; along the upward flow of flue gas, the first flue 21, the connecting flue 23, and the second flue 22 are connected sequentially; the superheater 5 is located on the side of the flue partition wall 4 closest to the second flue 22 and is used to cool the flue gas flowing in the first flue 21.
[0040] Through the above scheme, the flue partition wall 4 can divide the empty flue 2 into a first flue 21, a second flue 22, and a connecting flue 23. The first flue 21, the connecting flue 23, and the second flue 22 are connected in sequence, so that the high-temperature flue gas output from the boiler outlet flue 1 can first enter the first flue 21 and cool down in the superheater 5 (heat transfer is achieved through the flue partition wall 4). This can control the temperature of the flue gas flowing through the first flue 21 to below 950℃, which is below the melting point of ash. This allows the low-melting-point ash in the flue gas to adhere to the side wall of the first flue 21 and coke. This can reduce the ash content in the flue gas entering the tail flue 3, and avoid the problem of reduced heat exchange efficiency caused by coking on the heating surfaces of the low-temperature superheater 31 and the low-temperature reheater 32. At the same time, it can also avoid the problem of increased flue resistance caused by coking on the heating surfaces of the low-temperature superheater 31 and the low-temperature reheater 32, which would reduce the economic efficiency and safety of the unit operation.
[0041] In order to remove coke from the first flue 21, the system also includes a coke removal device 6.
[0042] Specifically, the decoking device 6 includes an ash hopper 61, a slag crusher 62, a separator 63, a slag silo 64, and a hydraulic soot blowing assembly 65. The ash hopper 61 is located at the lower end of the connecting flue 23. The ash hopper 61, the slag crusher 62, the separator 63, and the slag silo 64 are connected in sequence to form a slag discharge path. The liquid output end of the separator 63 is connected to the hydraulic soot blowing assembly 65, and the output end of the hydraulic soot blowing assembly 65 is connected to the first flue 21, thereby realizing water recycling.
[0043] Furthermore, a first valve 101 is provided between the ash hopper 61 and the slag crusher 62.
[0044] Furthermore, the hydraulic soot blowing assembly 65 includes a water pump 651, a water supply pipe 652, a water delivery pipe 653, and several hydraulic soot blowers 654; the water supply pipe 652 is connected to the input end of the water pump 651; the water delivery pipe 653 is sequentially connected to the liquid output end of the separator 63, the water pump 651, and the hydraulic soot blowers 654; the output end of the hydraulic soot blowers 654 is connected to the first flue 21.
[0045] Furthermore, a second valve 102 is provided between the water pump 651 and the hydraulic soot blower 654.
[0046] See Figure 1 The system also includes an air preheater 7 located downstream of the low-temperature reheater 32, with an air supply assembly 8 connected to the input end of the air preheater 7; the system also includes a heat exchanger 9, which has a first medium channel and a second medium channel, the first medium channel being connected to the air supply assembly 8, and the second medium channel being connected to the liquid output end of the separator 63 and the hydraulic soot blowing assembly 65.
[0047] Furthermore, the air supply assembly 8 includes a fan 80, a first pipeline 81, and a second pipeline 82; the first pipeline 81 is directly connected to the input end of the air preheater 7 and the output end of the fan 80; the second pipeline 82 is connected to the second medium channel and then to the first pipeline 81.
[0048] Furthermore, a third valve 103 is installed on the second pipeline 82.
[0049] It is known that the coke lumps attached to the side wall of the first flue 21, after being periodically blown away by the hydraulic soot blower 654, fall into the ash hopper 61. After the coke lumps and high-temperature water enter the slag crusher 62, the coke lumps are crushed and enter the separator 63. The separator 63 separates the crushed coke lumps and high-temperature water. The crushed coke lumps can be conveyed into the slag silo 64 via a pneumatic conveying device. The separated high-temperature water is cooled by heat exchanger 9 and then sent to water pump 651, which continues to deliver it to the hydraulic soot blower 654 for coke removal. The water conveyed by the air supply assembly 8 is heated by heat exchange and then sent to the air preheater 7 for further heat exchange. On the one hand, this can increase the inlet air temperature of the air preheater 7, effectively alleviating the cold end corrosion problem of the air preheater 7; on the other hand, it can realize the reuse of high-temperature water thermal energy, while avoiding excessively high temperature of the flushing water input into the first flue 21.
[0050] In this embodiment, the boiler outlet flue 1 is used to connect to a pulverized coal boiler, or to a circulating fluidized bed power plant boiler.
[0051] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.
Claims
1. A boiler tail flue system suitable for boilers burning only Zhundong coal, characterized in that, include: Boiler outlet flue (1); The empty flue (2) is connected to the boiler outlet flue (1); Tail flue (3) is connected downstream of the empty flue (2), and a low-temperature superheater (31) and a low-temperature reheater (32) are provided in the tail flue (3). A flue partition wall (4) extends from the boiler outlet flue (1) to the empty flue (2) to divide the empty flue (2) into a first flue (21), a second flue (22) and a connecting flue (23); along the flue flow upward, the first flue (21), the connecting flue (23) and the second flue (22) are connected in sequence; The superheater (5) is located on the side of the flue partition wall (4) near the second flue (22) and is used to cool the flue gas flowing in the first flue (21).
2. The boiler tail flue system suitable for burning only Zhundong coal according to claim 1, characterized in that, It also includes a decoking device (6); The decoking device (6) includes a ash hopper (61), a slag crusher (62), a separator (63), a slag silo (64), and a hydraulic soot blowing assembly (65). The ash hopper (61) is located at the lower end of the connecting flue (23). The ash hopper (61), the slag crusher (62), the separator (63) and the slag storage (64) are connected in sequence to form a slag discharge path. The liquid output end of the separator (63) is connected to the hydraulic soot blowing assembly (65), and the output end of the hydraulic soot blowing assembly (65) is connected to the first flue (21).
3. A boiler tail flue system suitable for burning only Zhundong coal according to claim 2, characterized in that, A first valve (101) is also provided between the ash hopper (61) and the slag crusher (62).
4. A boiler tail flue system suitable for burning only Zhundong coal according to claim 2, characterized in that, The hydraulic soot blowing assembly (65) includes a water pump (651), a water supply pipe (652), a water delivery pipe (653), and several hydraulic soot blowers (654). The water supply pipe (652) is connected to the input end of the water pump (651); The water supply pipe (653) is connected in sequence to the liquid output end of the separator (63), the water pump (651), and the hydraulic soot blower (654). The output end of the hydraulic soot blower (654) is connected to the first flue (21).
5. A boiler tail flue system suitable for burning only Zhundong coal according to claim 4, characterized in that, A second valve (102) is provided between the water pump (651) and the hydraulic soot blower (654).
6. A boiler tail flue system suitable for burning only Zhundong coal according to any one of claims 2 to 5, characterized in that, It also includes an air preheater (7) located downstream of the low-temperature reheater (32), with an air supply assembly (8) connected to the input end of the air preheater (7). The system also includes a heat exchanger (9), which has a first medium channel and a second medium channel. The first medium channel is connected to the air supply assembly (8), and the second medium channel is connected to the liquid output end of the separator (63) and the hydraulic soot blowing assembly (65).
7. A boiler tail flue system suitable for burning only Zhundong coal according to claim 6, characterized in that, The air supply assembly (8) includes a fan (80), a first pipeline (81), and a second pipeline (82); The first pipeline (81) is directly connected to the input end of the air preheater (7) and the output end of the fan (80); The second pipeline (82) is connected to the second medium channel and then connected to the first pipeline (81).
8. A boiler tail flue system suitable for burning only Zhundong coal according to claim 7, characterized in that, A third valve (103) is provided on the second pipeline (82).
9. A boiler tail flue system suitable for burning only Zhundong coal according to claim 1, characterized in that, The boiler outlet flue (1) is used to connect to a pulverized coal boiler, or to a circulating fluidized bed power plant boiler.