Automatic stable combustion device and thermal power generating unit combustion system

Abstract

The invention relates to an automatic stable combustion device and a thermal power generating unit combustion system. The automatic stable combustion device comprises a primary air pulverized coal pipe, a combustion chamber, a reducing pipe, a micro-oil gun and a secondary air box, the primary air pulverized coal pipe is communicated with the combustion chamber, the reducing pipe is arranged in the primary air pulverized coal pipe, a small-diameter port faces the combustion chamber, the micro-oil gun is arranged on the outer wall face of the primary air pulverized coal pipe and extends into the combustion chamber, and the secondary air box is communicated with the combustion chamber. An air outlet of the secondary air box faces the combustion chamber and communicates with the combustion chamber. According to the automatic stable-combustion combustion device, the concentration of pulverized coal entering the combustion chamber is increased, ignition of the pulverized coal is facilitated, the pulverized coal is ignited through the micro-oil gun, oil is saved, normal combustion of the pulverized coal can be guaranteed when the boiler operates at a low load, and therefore the combustion stability of the pulverized coal is improved, and the combustion efficiency of the boiler is improved. The problems that when the thermal power generating unit operates at a low load, pulverized coal combustion is unstable, and negative pressure of a hearth is generated are solved, and therefore the operation stability of the thermal power generating unit during peak shaving is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of pulverized coal combustion, and in particular to an automatic stable combustion device and a combustion system for a thermal power unit. Background Art

[0002] As the proportion of renewable energy in the power grid gradually increases, the demand for peak load regulation also gradually increases. Compared with renewable energy and other power sources, thermal power units have better peak load regulation performance. When the boiler of a thermal power unit is running at low load for peak load regulation, the concentration of pulverized coal put into the boiler is reduced, which can easily cause the problem of unstable combustion of pulverized coal in the boiler and negative pressure in the furnace. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention proposes an automatic stable combustion device, which improves the stability of coal powder combustion and solves the problem of unstable coal powder combustion and negative pressure in the furnace when the thermal power unit is running at low load, thereby ensuring the stability of the thermal power unit during peak operation.

[0005] An embodiment of the present invention provides a combustion system for a thermal power unit.

[0006] According to an embodiment of the present invention, an automatic stable combustion device includes a primary air pulverized coal pipe, a combustion chamber, a reduced diameter pipe, a micro-oil gun and a secondary air box, wherein one end of the primary air pulverized coal pipe in its extension direction is used to connect to a pulverized coal source, and the other end of the primary air pulverized coal pipe in its extension direction is connected to the combustion chamber; the reduced diameter pipe is arranged in the primary air pulverized coal pipe, and the reduced diameter pipe has a large diameter port and a small diameter port, the large diameter port faces the one end of the primary air pulverized coal pipe, the large diameter port fits the inner wall surface of the primary air pulverized coal pipe, and the small diameter port faces the combustion chamber; the micro-oil gun is arranged on the outer wall surface of the primary air pulverized coal pipe, and the micro-oil gun extends into the combustion chamber; the secondary air box is arranged at the other end of the primary air pulverized coal pipe, and the secondary air box has an air inlet and an air outlet, and the air outlet faces the combustion chamber and is connected to the combustion chamber.

[0007] The automatic stable combustion device of the embodiment of the present invention increases the concentration of coal powder entering the combustion chamber, is beneficial to the ignition of coal powder, and ignites the coal powder through a micro-oil gun, which not only saves oil, but also ensures the normal combustion of coal powder when the boiler is running at low load, thereby improving the stability of coal powder combustion and solving the problem of unstable coal powder combustion and negative pressure in the furnace when the thermal power unit is running at low load, thereby ensuring the stability of the operation of the thermal power unit during peak load regulation.

[0008] In some embodiments, the automatic stable combustion device further includes a coal powder atomizer, and the coal powder atomizer is arranged on the small-diameter port to atomize the coal powder discharged from the reduced-diameter pipe.

[0009] In some embodiments, the automatic stable combustion device further includes an oil atomizer, and the oil atomizer is arranged at the outlet end of the micro-oil gun.

[0010] In some embodiments, there are multiple micro-oil guns, and the multiple micro-oil guns are evenly distributed around the primary air pulverized coal pipe.

[0011] In some embodiments, the diameter of the reducing tube gradually decreases from the large-diameter port to the small-diameter port.

[0012] In some embodiments, the inner diameter of the small-diameter port is half the inner diameter of the primary air pulverized coal pipe.

[0013] In some embodiments, the thickness of the reduced diameter pipe is the same as the thickness of the primary air pulverized coal pipe.

[0014] In some embodiments, the automatic stable combustion device further includes a wear-resistant ring, the outer wall of the wear-resistant ring is connected to the inner wall of the primary air pulverized coal pipe, one end of the wear-resistant ring is connected to the large diameter port, and the other end of the wear-resistant ring is arc-shaped.

[0015] In some embodiments, the secondary air box surrounds the primary air pulverized coal pipe, and the air outlet surrounding the primary air pulverized coal pipe and the micro-oil gun is provided on the side of the secondary air box facing the combustion chamber.

[0016] The combustion system of a thermal power unit in the embodiment of the present invention includes the automatic stable combustion device.

[0017] The combustion system of the thermal power unit in the embodiment of the present invention can ensure the stability of coal powder combustion when the boiler is running at low load for peak load regulation, thereby ensuring the stability of the thermal power unit during peak load regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of an automatic stable combustion device according to an embodiment of the present invention.

[0019] Reference numerals:

[0020] Combustion device 100;

[0021] Pulverized coal pipe 1, combustion chamber 2, reducing pipe 3, micro oil gun 4, secondary air box 5, air inlet 51, air outlet 52, pulverized coal atomizer 6, oil atomizer 7, wear-resistant ring 8. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0023] Please refer to the attached Figure 1 , the automatic stable combustion device 100 and the combustion system of the thermal power unit according to the embodiment of the present invention are described in detail.

[0024] The combustion system of a thermal power unit according to the embodiment of the present invention includes an automatic stable combustion device 100 .

[0025] The automatic stable combustion device 100 of the embodiment of the present invention comprises a primary air pulverized coal pipe 1, a combustion chamber 2, a reducing pipe 3, a micro oil gun 4 and a secondary air box 5. The primary air pulverized coal pipe 1 has one end (e.g. Figure 1 The left end of the primary air pulverized coal pipe 1 is used to connect to the pulverized coal source, and the other end of the primary air pulverized coal pipe 1 in its extension direction (for example Figure 1 The right end in the middle) is connected to the combustion chamber 2. The diameter reduction pipe 3 is arranged in the primary air pulverized coal pipe 1, and the diameter reduction pipe 3 has a large diameter port and a small diameter port. The large diameter port faces the end of the primary air pulverized coal pipe 1, the large diameter port fits the inner wall surface of the primary air pulverized coal pipe 1, and the small diameter port faces the combustion chamber 2. The micro oil gun 4 is arranged on the outer wall surface of the primary air pulverized coal pipe 1, and the micro oil gun 4 extends into the combustion chamber 2. The secondary air box 5 is arranged at the other end of the primary air pulverized coal pipe 1, and the secondary air box 5 has an air inlet 51 and an air outlet 52, and the air outlet 52 faces the combustion chamber 2 and is connected to the combustion chamber 2. The fresh air containing oxygen enters the secondary air box 5 from the air inlet 51 of the secondary sub-box, and is then discharged into the combustion chamber 2 from the air outlet 52 to provide oxygen for the combustion chamber 2.

[0026] When the automatic stable combustion device 100 of the embodiment of the present invention is in use, the one end of the primary air pulverized coal pipe 1 is connected to the pulverized coal source, and the pulverized coal enters the primary air pulverized coal pipe 1 and then enters the reduced diameter pipe 3. Since the diameter of the small diameter port of the reduced diameter pipe 3 is smaller than the diameter of the large diameter port, the concentration of the pulverized coal after passing through the reduced diameter pipe 3 is increased, so that the pulverized coal is easier to ignite.

[0027] When the thermal power unit is running at low load, the micro-oil gun 4 is connected to the detection and control system of the thermal power unit. If the detection and control system of the thermal power unit detects that the furnace has negative pressure, the combustion is unstable, and the intensity of the combustion fire detection is reduced, the detection and control system controls the micro-oil gun 4 to automatically start (the micro-oil gun 4 is turned on) to ignite the higher concentration of coal powder in the combustion chamber 2. When the detection and control system detects that the negative pressure in the furnace is stable and the intensity of the fire detection is increased, the detection and control system controls the micro-oil gun 4 to automatically exit (the micro-oil gun 4 is turned off).

[0028] Therefore, the automatic stable combustion device 100 of the embodiment of the present invention increases the concentration of coal powder entering the combustion chamber 2, is conducive to the ignition of coal powder, and ignites the coal powder through the micro-oil gun 4, which not only saves oil, but also ensures the normal combustion of coal powder when the boiler is running at low load, thereby improving the stability of coal powder combustion, solving the problem of unstable coal powder combustion and negative pressure in the furnace when the thermal power unit is running at low load, thereby ensuring the stability of the thermal power unit during peak operation.

[0029] In some embodiments, the diameter of the reducing tube 3 gradually decreases from the large diameter port to the small diameter port. In other words, the reducing tube 3 is a reducing tube, so a gradually shrinking flow path is formed for the coal powder, which can gradually concentrate the coal powder passing through the reducing tube 3, thereby reducing the problem of local turbulence and eddy current generated by the coal powder during the flow and concentration process, ensuring the smoothness of the concentration process of the coal powder, and also helping to reduce the collision and wear of the coal powder on the reducing tube 3, which is conducive to improving the service life of the reducing tube 3 and reducing the maintenance cost of the automatic stable combustion device 100 of the embodiment of the present invention.

[0030] In some embodiments, the thickness of the reduced diameter pipe 3 is greater than or equal to the thickness of the primary air pulverized coal pipe 1. This ensures that the wear degree of the reduced diameter pipe 3 by the pulverized coal is less than or equal to that of the primary air pulverized coal pipe 1, thereby ensuring the purpose of concentrating the pulverized coal by the reduced diameter pipe 3. It should be noted that the reduced diameter pipe 3 and the primary air pulverized coal pipe 1 are made of the same material.

[0031] Specifically, in this embodiment, the thickness of the reduced diameter pipe 3 is equal to the thickness of the primary air pulverized coal pipe 1 .

[0032] In some embodiments, the inner diameter of the small-diameter port is half the inner diameter of the primary air pulverized coal pipe 1. After the pulverized coal entering the primary air pulverized coal pipe 1 is concentrated by the reduced diameter pipe 3, the concentration is doubled (i.e., twice the original concentration). The automatic stable combustion device 100 of the embodiment of the present invention adopts this inner diameter ratio, which can better achieve the concentration of pulverized coal, facilitate the combustion and stable combustion of pulverized coal, and control the wear of pulverized coal on the reduced diameter pipe 3 within a certain range, thereby ensuring the service life of the reduced diameter pipe 3 and reducing the maintenance cost of the automatic stable combustion device 100.

[0033] The automatic stable combustion device 100 of the embodiment of the present invention further comprises a wear-resistant ring 8, the outer wall surface of the wear-resistant ring 8 is connected to the inner wall surface of the primary air pulverized coal pipe 1, one end of the wear-resistant ring 8 is connected to the large diameter port, and the other end of the wear-resistant ring 8 is arc-shaped. Figure 1As shown, the right end of the wear-resistant ring 8 is connected to the large diameter port, and the left end of the wear-resistant ring 8 is arc-shaped. In other words, the arc-shaped surface of the wear-resistant ring 8 is the windward surface, that is, when the coal powder enters the reduced diameter pipe 3 from the primary air coal powder pipe 1, it flows through the arc-shaped surface of the wear-resistant ring 8. The arc-shaped surface is a smooth surface, which is conducive to reducing the smoothness of the coal powder when it is redirected through the large diameter port, avoiding the problem of local turbulence and eddy current generated by the coal powder at the large diameter port, reducing the friction between the coal powder and the large diameter port, thereby helping to reduce the collision and wear of the coal powder on the reduced diameter pipe 3, further helping to increase the service life of the reduced diameter pipe 3, and further reducing the maintenance cost of the automatic stable combustion device 100 of the embodiment of the present invention.

[0034] Specifically, the wear-resistant ring 8 and the reducing pipe 3 are an integral structure.

[0035] The automatic stable combustion device 100 of the embodiment of the present invention further includes a pulverized coal atomizer 6, which is arranged on the small-diameter port to atomize the pulverized coal discharged from the reduced diameter pipe 3. The pulverized coal atomizer 6 atomizes the concentrated pulverized coal and sprays it into the combustion chamber 2 after atomization. The atomized pulverized coal has smaller particles and a higher concentration, so that the flammability of the pulverized coal can be further improved, and then when the boiler is running at low load, the stability of the pulverized coal combustion can be further improved, and the stability of the operation of the thermal power unit during peak load regulation can be further ensured.

[0036] The automatic stable combustion device 100 of the embodiment of the present invention further includes an oil atomizer 7, which is arranged at the outlet end of the micro-oil gun 4. The oil atomizer 7 refines the oil sprayed by the micro-oil gun 4, so that the pulverized coal is easier to ignite, thereby making the pulverized coal burn more stably, and then further improves the stability of the pulverized coal combustion when the boiler is running at low load, and further ensures the stability of the operation of the thermal power unit during peak load regulation.

[0037] Specifically, there are multiple micro-oil guns 4, and the multiple micro-oil guns 4 are evenly distributed around the primary air pulverized coal pipe 1. Therefore, after the pulverized coal flows out of the small-diameter port, the micro-oil guns 4 around it are evenly distributed, so that the ignition points of the pulverized coal are evenly distributed, making the pulverized coal easier to ignite and the pulverized coal combustion more stable, and then when the boiler is running at low load, the stability of the pulverized coal combustion is further improved, and the stability of the operation of the thermal power unit during peak load regulation is further guaranteed.

[0038] In this embodiment, there are two micro-oil guns 4 , and an oil atomizer 7 is disposed at the outlet end of the two micro-oil guns 4 .

[0039] In some embodiments, the secondary air box 5 surrounds the primary air pulverized coal pipe 1, and an air outlet 52 surrounding the primary air pulverized coal pipe 1 and the micro-oil gun 4 is provided on the side of the secondary air box 5 facing the combustion chamber 2. The air discharged from the air outlet 52 evenly surrounds the pulverized coal, providing relatively evenly distributed oxygen for the combustion of the pulverized coal, thereby making the pulverized coal easier to ignite and burn, making the pulverized coal combustion more stable, and then further improving the stability of the pulverized coal combustion when the boiler is running at low load, and further ensuring the stability of the operation of the thermal power unit during peak load regulation.

[0040] Therefore, the automatic stable combustion device 100 of the embodiment of the present invention realizes the stable combustion of coal powder under the low-load condition of the thermal power unit, and solves the problem of unstable boiler combustion and easy boiler fire extinguishing during the deep peak regulation period of the thermal power unit.

[0041] Therefore, the combustion system of the thermal power unit according to the embodiment of the present invention can ensure the stability of coal powder combustion when the boiler is running at low load for peak load regulation, thereby ensuring the stability of the thermal power unit during peak load regulation.

[0042] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0044] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0046] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0047] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An automatic stable combustion device (100), characterized in that: include: A primary air pulverized coal pipe (1) and a combustion chamber (2), wherein one end of the primary air pulverized coal pipe (1) in its extension direction is used to connect to a pulverized coal source, and the other end of the primary air pulverized coal pipe (1) in its extension direction is connected to the combustion chamber (2); A reduced diameter pipe (3), the reduced diameter pipe (3) being arranged in the primary air pulverized coal pipe (1), the reduced diameter pipe (3) having a large diameter port and a small diameter port, the large diameter port facing the one end of the primary air pulverized coal pipe (1), the large diameter port being in contact with the inner wall surface of the primary air pulverized coal pipe (1), and the small diameter port facing the combustion chamber (2); A micro-oil gun (4), the micro-oil gun (4) being arranged on the outer wall surface of the primary air pulverized coal pipe (1), and the micro-oil gun (4) extending into the combustion chamber (2); A secondary wind box (5), the secondary wind box (5) being arranged at the other end of the primary air pulverized coal pipe (1), the secondary wind box (5) having an air inlet (51) and an air outlet (52), the air outlet (52) facing the combustion chamber (2) and being in communication with the combustion chamber (2).

2. The automatic stable combustion device (100) according to claim 1, characterized in that: It further comprises a coal powder atomizer (6), wherein the coal powder atomizer (6) is arranged on the small-diameter port to atomize the coal powder discharged from the reduced-diameter pipe (3).

3. The automatic stable combustion device (100) according to claim 1, characterized in that: It further comprises an oil atomizer (7), wherein the oil atomizer (7) is arranged at the outlet end of the micro-oil gun (4).

4. The automatic stable combustion device (100) according to claim 1, characterized in that: The micro-oil guns (4) are multiple, and the multiple micro-oil guns (4) are evenly distributed around the primary air pulverized coal pipe (1).

5. The automatic stable combustion device (100) according to claim 1, characterized in that: The diameter of the reducing tube (3) gradually decreases from the large-diameter port toward the small-diameter port.

6. The automatic stable combustion device (100) according to claim 1, characterized in that: The inner diameter of the small-diameter port is half the inner diameter of the primary air pulverized coal pipe (1).

7. The automatic stable combustion device (100) according to claim 1, characterized in that: The thickness of the reduced diameter pipe (3) is the same as the thickness of the primary air pulverized coal pipe (1).

8. The automatic stable combustion device (100) according to claim 1, characterized in that: It further comprises a wear-resistant ring (8), the outer wall surface of the wear-resistant ring (8) is connected to the inner wall surface of the primary air pulverized coal pipe (1), one end of the wear-resistant ring (8) is connected to the large-diameter port, and the other end of the wear-resistant ring (8) is arc-shaped.

9. The automatic stable combustion device (100) according to claim 1, characterized in that: The secondary air box (5) surrounds the primary air pulverized coal pipe (1), and the side of the secondary air box (5) facing the combustion chamber (2) is provided with the air outlet (52) surrounding the primary air pulverized coal pipe (1) and the micro-oil gun (4).

10. A combustion system for a thermal power unit, characterized in that: It comprises the automatic stable combustion device (100) as claimed in any one of claims 1 to 9.

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