Ultra-low load stable combustion equipment of opposed firing boiler
By using a counter-fired boiler design and incorporating components such as exhaust gas separation and a pre-combustion chamber, stable combustion of the boiler under low load is achieved, solving the problem of stable combustion of coal-fired boilers during deep peak shaving and improving the boiler's stable combustion capability and safety.
Patent Information
- Application Number
- CN202520128712.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-01-20
AI Technical Summary
During deep peak shaving, coal-fired boilers experience a drop in furnace temperature, difficulty in igniting pulverized coal, poor flame stability, and are prone to flameout, posing a fire extinguishing hazard and making it difficult to meet the 15% minimum stable combustion load requirement.
It adopts a counter-firing boiler design, which includes a peak-shaving burner, a conventional swirl burner and a burnout air system. Through components such as a waste gas separation device and a pre-combustion chamber, it achieves separation and concentration of primary air and pulverized coal gas flow. Combined with internal and external secondary air regulation and combustion at the waste gas nozzle, it has the ability to achieve ultra-low load self-stabilized combustion under single burner conditions without oil injection or plasma-assisted combustion.
It enables stable combustion of the boiler at 15% of its rated load, has deep peak-shaving capability, avoids the risk of furnace fire extinguishing, and improves the stable combustion capability of coal-fired boilers.
Smart Images
Figure CN223826223U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of power station boiler, more specifically to the technical field of counter -current combustion boiler ultra -low load stable combustion equipment. BACKGROUND
[0002] In recent years, according to national policy, thermal power generating unit needs to meet the demand of power grid depth peak shaving, and large coal-fired boiler needs to meet the requirement of 20% minimum stable combustion load without oil or plasma combustion assistance;According to the demonstration unit of electric power planning requirement, it also needs to meet 15% minimum stable combustion load. In the process of depth peak shaving, the furnace temperature drops, the coal powder is difficult to ignite, the flame stability is poor, and the flame is easy to extinguish, which has the major accident hidden danger of furnace fire. The low load stable combustion of boiler is the key of depth peak shaving of thermal power generating unit, and improving the stable combustion capacity of coal-fired boiler is an important task to be solved in depth peak shaving. CONTENT OF THE UTILITY MODEL
[0003] The utility model discloses a counter -current combustion boiler ultra -low load stable combustion equipment.
[0004] The utility model discloses a counter -current combustion boiler ultra -low load stable combustion equipment to realize the following technical scheme specifically:
[0005] The utility model provides a counter -current combustion boiler ultra -low load stable combustion equipment, including two peak shaving combustors arranged on the side wall of the combustor furnace, a plurality of conventional swirl combustors and a plurality of burnout air systems, each peak shaving combustor, each conventional swirl combustor and each burnout air system are communicated with the inside of the combustor furnace, each peak shaving combustor is communicated with the corresponding coal mill, and each conventional swirl combustor is matched with the corresponding coal mill.
[0006] Specifically, the combustion equipment includes two peak shaving combustors on the front and rear side walls of the combustor furnace, a plurality of conventional swirl combustors and a plurality of burnout air systems. The peak shaving combustor is arranged with two corresponding coal mills, and the conventional swirl combustor corresponds to the remaining coal mill.
[0007] In an embodiment, the peak shaving combustor includes a precombustion chamber communicated with the inside of the combustor furnace, a flue gas separation device communicated with the coal mill, a primary air nozzle communicated with the precombustion chamber, a primary air channel communicated with the primary air nozzle and the flue gas separation device at both ends respectively, a flue gas flow channel assembly communicated with the flue gas separation device and a pulverized coal concentrator arranged in the primary air channel, the pulverized coal concentrator is close to the primary air nozzle and divides the channel into two.
[0008] Specifically, the peak-shaving burner is provided with a pre-chamber, a flue gas separation device and a flue gas nozzle, and can have the self-stabilizing combustion capability at ultra-low load without oil injection or plasma combustion support of a single burner. When the boiler needs to operate at low load, the peak-shaving burner is put into operation to meet the deep peak-shaving capability of 15% of the rated load of the boiler.
[0009] When the boiler operates at low load, the peak-shaving burner is put into operation, and the primary air pulverized coal gas flow first passes through the flue gas separation device to separate the primary air pulverized coal gas flow into a high-concentration pulverized coal gas flow and a flue gas flow, and the high-concentration pulverized coal gas flow enters the primary air passage again. The pulverized coal concentrator arranged in the primary air passage can further separate the pulverized coal gas flow into two gas flows with different concentrations, and then the gas flow enters the pre-chamber through the primary air nozzle to stabilize combustion in the pre-chamber.
[0010] In one embodiment, the peak-shaving burner further comprises a central air passage located in the primary air passage, one end of the central air passage extending out of the primary air passage, and the other end of the central air passage communicating with the primary air nozzle.
[0011] In one embodiment, the peak-shaving burner further comprises an inner secondary air passage, a secondary air nozzle and an inner secondary air swirl adjusting baffle; the inner secondary air passage is arranged outside the primary air passage, the secondary air nozzle is connected to the end of the inner secondary air passage, and the inner secondary air swirl adjusting baffle is located in the inner secondary air passage.
[0012] Specifically, the inner secondary air is a swirl flow, and the swirl intensity can be adjusted by the inner secondary air swirl adjusting baffle.
[0013] In one embodiment, the peak-shaving burner further comprises an outer secondary air passage, an outer secondary air nozzle and an outer secondary air adjusting device, the outer secondary air passage is arranged outside the primary air passage, the outer secondary air adjusting device is arranged in the outer secondary air passage, and the number of the outer secondary air nozzles is multiple, which are circumferentially distributed on the outer secondary air passage and each of which communicates with the burner hearth.
[0014] In one embodiment, each of the outer secondary air nozzles communicates with the burner hearth in a horizontal connection mode.
[0015] Specifically, the outer secondary air is a straight flow, which is injected into the burner hearth through the outer secondary air nozzles.
[0016] In one embodiment, the flue gas flow passage assembly comprises a flue gas air pipe communicating with the flue gas separation device, a flue gas adjusting valve arranged on the flue gas air pipe and a flue gas nozzle arranged at the end of the flue gas air pipe, the flue gas nozzle communicating with the inside of the burner hearth.
[0017] Specifically, by adjusting the opening degree of the flue gas adjusting valve, the concentration of the pulverized coal entering the primary air passage can also be adjusted.
[0018] In one embodiment, a perimeter air nozzle is arranged at the flue gas nozzle and communicates with the inside of the burner furnace, and the perimeter air is drawn from the secondary air in the air box.
[0019] Specifically, the flue gas flow is injected into the furnace through the flue gas duct and the flue gas nozzle, and the flue gas nozzle is surrounded by the perimeter air nozzle, and the perimeter air is drawn from the secondary air in the air box, so that the flue gas nozzle can be cooled and protected.
[0020] In one embodiment, the precombustion chamber is integrally formed by wear-resistant and high-temperature-resistant castable, the diameter of the precombustion chamber outlet is D, the diameter of the precombustion chamber inlet is d, the distance from the precombustion chamber inlet to the center line of the water-cooled wall is L, the value of D / d is 1.5-2, and the value of L / D is 0.5-1.
[0021] In one embodiment, the flame stabilizing tooth and the expansion cone are further arranged in the primary air nozzle.
[0022] Specifically, the flame stabilizing tooth and the expansion cone are further arranged in the primary air nozzle, so that the pulverized coal combustion can be strengthened, and the burner stable combustion can be further ensured.
[0023] The beneficial effects of the present application are as follows:
[0024] 1. The peak regulation burner is provided with a precombustion chamber, a flue gas separation device and a flue gas nozzle, so that the self-stable combustion capacity of ultra-low load can be achieved without oil injection or plasma combustion assistance of a single burner, and when the boiler needs to be operated at low load, the peak regulation burner can be operated to meet the deep peak regulation capacity of 15% of the rated load of the boiler.
[0025] 2. The flue gas flow is injected into the furnace through the flue gas duct and the flue gas nozzle, and the flue gas nozzle is surrounded by the perimeter air nozzle, and the perimeter air is drawn from the secondary air in the air box, so that the flue gas nozzle can be cooled and protected. BRIEF DESCRIPTION OF DRAWINGS
[0026] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.
[0027] Figure 1 is a structural schematic view of the present application;
[0028] Figure 2 is Figure 1 the left view of the present application;
[0029] Figure 3 is a structural schematic view of the peak regulation burner;
[0030] Figure 4 is Figure 3 schematic view of the center K;
[0031] Figure 5 is Figure 3 schematic view of the structure at A-A in the center;
[0032] Reference signs: 1 - pre-combustion chamber, 2 - central air passage, 3 - primary air passage, 4 - pulverized coal concentrator, 5 - primary air nozzle, 6 - inner secondary air passage, 7 - inner secondary air nozzle, 8 - inner secondary air swirl adjusting baffle, 9 - outer secondary air nozzle, 10 - outer secondary air adjusting device, 11 - exhaust gas separation device, 12 - exhaust gas air pipe, 13 - exhaust gas adjusting valve, 14 - exhaust gas nozzle, 15 - peripheral air nozzle. DETAILED DESCRIPTION
[0033] In order to make the technical problems, technical solutions and technical effects of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.
[0034] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.
[0035] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", etc. are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.
[0036] In the description of the embodiments of the present application, it should be noted that the orientation or position relationship indicated by the terms "inner", "outer", "upper", etc. is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship when the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, cannot be understood as a limitation on the present application.
[0037] As Figures 1 to 5As shown, the utility model provides the super low load stable combustion combustion equipment of the combustion boiler, including two peak shaving combustor which symmetry sets on the side wall of the burner hearth, a plurality of conventional swirl burner and a plurality of burnout air system, each peak shaving combustor, each conventional swirl burner and each burnout air system all are communicated with the inside of the burner hearth, each peak shaving combustor is communicated with corresponding coal mill, each conventional swirl burner is matched with corresponding coal mill.
[0038] Specifically, the combustion equipment includes two peak shaving combustors on the front and rear side walls of the burner hearth, a plurality of conventional swirl burners and a plurality of burnout air systems. The peak shaving combustors are arranged corresponding to two coal mills, and the conventional swirl burners correspond to the remaining coal mills.
[0039] In one embodiment, the peak shaving combustor includes a pre-chamber 1 communicated with the inside of the burner hearth, a flue gas separation device 11 communicated with the coal mill, a primary air nozzle 5 communicated with the pre-chamber 1, a primary air channel 3 having two ends communicated with the primary air nozzle 5 and the flue gas separation device 11 respectively, a flue gas flow channel assembly communicated with the flue gas separation device 11, and a pulverized coal concentrator 4 arranged in the primary air channel 3, which is close to the primary air nozzle 5 and divides the channel into two.
[0040] Specifically, the peak shaving combustor is provided with a pre-chamber 1, a flue gas separation device 11 and a flue gas nozzle 14, which can have the self-stabilizing combustion capability at ultra-low load without oil injection or plasma combustion assistance of a single combustor. When the boiler needs to operate at low load, the peak shaving combustor is put into operation to meet the deep peak shaving capability of 15% of the rated load of the boiler.
[0041] When the boiler operates at low load, the peak shaving combustor is put into operation, and the primary air pulverized coal gas flow first passes through the flue gas separation device 11 to separate the primary air pulverized coal gas flow into a high-concentration pulverized coal gas flow and a flue gas flow, and the high-concentration pulverized coal gas flow enters the primary air channel 3. The pulverized coal concentrator 4 arranged in the primary air channel 3 can further separate the pulverized coal gas flow into two streams with different concentrations, and then enter the pre-chamber 1 through the primary air nozzle 5 for stable combustion in the pre-chamber 1.
[0042] In one embodiment, the peak shaving combustor further includes a central air channel 2 located in the primary air channel 3, one end of the central air channel 2 extending out of the primary air channel 3, and the other end of the central air channel 2 communicated with the primary air nozzle 5.
[0043] In one embodiment, the peak shaving combustor further includes an inner secondary air channel 6, a secondary air nozzle and an inner secondary air swirl adjusting baffle 8; the inner secondary air channel 6 is sleeved outside the primary air channel 3, the secondary air nozzle is connected to the end of the inner secondary air channel 6, and the inner secondary air swirl adjusting baffle 8 is located in the inner secondary air channel 6.
[0044] Specifically, the inner secondary air is a cyclone gas flow, and the cyclone intensity can be adjusted by the inner secondary air cyclone adjusting baffle 8.
[0045] In one embodiment, the peak-shaving burner further comprises an outer secondary air channel, outer secondary air nozzles 9, and an outer secondary air adjusting device 10. The outer secondary air channel is sleeved outside the primary air channel 3. The outer secondary air adjusting device 10 is arranged in the outer secondary air channel. The outer secondary air nozzles 9 are in a plurality of circumferentially distributed forms on the outer secondary air channel, and each outer secondary air nozzle 9 is in communication with the burner hearth.
[0046] In one embodiment, each outer secondary air nozzle 9 is in horizontal connection with the burner hearth.
[0047] Specifically, the outer secondary air is a straight flow gas flow, which is injected into the burner hearth through the outer secondary air nozzles 9.
[0048] In one embodiment, the exhaust gas flow channel assembly comprises an exhaust gas air pipe 12 in communication with the exhaust gas separation device 11, an exhaust gas adjusting valve 13 arranged on the exhaust gas air pipe 12, and an exhaust gas nozzle 14 arranged at the end of the exhaust gas air pipe 12, which is in communication with the inside of the burner hearth.
[0049] Specifically, by adjusting the opening degree of the exhaust gas adjusting valve 13, the concentration of the pulverized coal entering the primary air channel 3 can also be adjusted.
[0050] In one embodiment, the exhaust gas nozzle 14 is provided with a perimeter air nozzle 15 in communication with the inside of the burner hearth, and the perimeter air is introduced from the secondary air in the air box.
[0051] Specifically, the exhaust gas flow is injected into the hearth for combustion through the exhaust gas air pipe 12 and the exhaust gas nozzle 14. The exhaust gas nozzle 14 is provided with a perimeter air nozzle 15 around it, and the perimeter air is introduced from the secondary air in the air box to cool and protect the exhaust gas nozzle 14.
[0052] In one embodiment, the pre-chamber 1 is integrally formed by wear-resistant and high-temperature-resistant castable material. The outlet diameter of the pre-chamber 1 is D, the inlet diameter of the pre-chamber 1 is d, the distance from the inlet of the pre-chamber 1 to the center line of the water-cooled wall is L, the value of D / d is 1.5-2, and the value of L / D is 0.5-1.
[0053] In one embodiment, the flame stabilizing teeth and the expansion cone are further arranged in the primary air nozzle 5.
[0054] Specifically, the flame stabilizing teeth and the expansion cone are further arranged in the primary air nozzle 5, which can strengthen the combustion of the pulverized coal and further ensure the stable combustion of the burner.
[0055] Example 1
[0056] The present embodiment provides a kind of equipment for the stable combustion of coal-fired boiler at ultra-low load.
[0057] For a certain 660 MW opposed firing boiler, the scheme is as follows:
[0058] The combustion equipment includes 12 peak-shaving burners arranged on the front and rear walls, 24 conventional swirl burners, and a multi-layer overfire air system. The peak-shaving burners are arranged on the lowermost layer of the front and rear walls and correspond to two coal mills; the conventional swirl burners are arranged on the middle and upper layers of the front and rear walls and correspond to the remaining four coal mills.
[0059] The peak-shaving burners are provided with a pre-chamber, a spent gas air separation device, and a spent gas nozzle, and can have a self-stable combustion capability at ultra-low load without oil or plasma combustion support for a single burner. When the boiler needs to operate at low load, the bottom layer of the peak-shaving burners is fired, and the remaining burners are operated at medium and high load conditions.
Claims
1. A counter-firing combustion boiler with ultra-low load stable combustion equipment, characterized in that, It includes two peak-shaving burners symmetrically arranged on the side wall of the burner furnace, multiple conventional swirl burners, and multiple burnout air systems. Each of the peak-shaving burners, conventional swirl burners, and burnout air systems is connected to the inside of the burner furnace. Each of the peak-shaving burners is connected to the corresponding coal mill, and each of the conventional swirl burners is matched to the corresponding coal mill.
2. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 1, characterized in that, The peak-shaving burner includes a pre-combustion chamber (1) connected to the inside of the burner furnace, a waste gas separation device (11) connected to the coal mill, a primary air nozzle (5) connected to the pre-combustion chamber (1), a primary air passage (3) connected at both ends to the primary air nozzle (5) and the waste gas separation device (11) respectively, a waste gas flow passage assembly connected to the waste gas separation device (11), and a coal powder concentrator (4) disposed in the primary air passage (3). The coal powder concentrator (4) is located near the primary air nozzle (5) and divides the passage into two.
3. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 2, characterized in that, The peak-shaving burner also includes a central air channel (2) located inside the primary air channel (3), one end of the central air channel (2) extends out of the primary air channel (3), and the other end of the central air channel (2) is connected to the primary air nozzle (5).
4. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 3, characterized in that, The peak-shaving burner also includes an inner secondary air channel (6), a secondary air nozzle, and an inner secondary air swirl regulating baffle (8); the inner secondary air channel (6) is sleeved on the outside of the primary air channel (3), the secondary air nozzle is connected to the end of the inner secondary air channel (6), and the inner secondary air swirl regulating baffle (8) is located inside the inner secondary air channel (6).
5. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 2, characterized in that, The peak-shaving burner also includes an external secondary air duct, an external secondary air nozzle (9), and an external secondary air regulating device (10). The external secondary air duct is sleeved outside the primary air duct (3), and the external secondary air regulating device (10) is located inside the external secondary air duct. There are multiple external secondary air nozzles (9), which are evenly distributed in a circle on the external secondary air duct, and each external secondary air nozzle (9) is connected to the burner furnace.
6. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 5, characterized in that, Each of the external secondary air nozzles (9) is connected to the burner furnace in a horizontal manner.
7. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 2, characterized in that, The exhaust gas flow channel assembly includes an exhaust gas duct (12) connected to the exhaust gas separation device (11), an exhaust gas regulating valve (13) provided on the exhaust gas duct (12), and an exhaust gas nozzle (14) provided at the end of the exhaust gas duct (12), the exhaust gas nozzle (14) being connected to the interior of the burner furnace.
8. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 7, characterized in that, A perimeter air nozzle (15) communicating with the inside of the burner furnace is provided at the exhaust gas nozzle (14), and the perimeter air is drawn from the secondary air in the air box.
9. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 2, characterized in that, The pre-combustion chamber (1) is integrally formed from wear-resistant and high-temperature resistant castable material. The outlet diameter of the pre-combustion chamber (1) is D, the inlet diameter of the pre-combustion chamber (1) is d, and the distance from the inlet of the pre-combustion chamber (1) to the center line of the water-cooled wall is L. The value of D / d is 1.5~2, and the value of L / D is 0.5~1.
10. The ultra-low load stable combustion equipment for counter-firing boilers according to claim 2, characterized in that, The primary air nozzle (5) is also equipped with flame stabilizing teeth and an expansion cone.