A pulverized coal boiler oxygen-enriched gas ignition and boiler stable combustion burner

Abstract

The utility model provides an oxygen-enriched fuel gas ignition and boiler stable combustion burner for a pulverized coal boiler, comprising a primary air / pulverized coal elbow, a primary air / pulverized coal horizontal nozzle and an oxygen-enriched ignition and stable combustion burner, wherein one end of the primary air / pulverized coal elbow inlet is connected to a pulverized coal pipeline, and the other end is connected to the primary air / pulverized coal horizontal nozzle, the outlet end of the primary air / pulverized coal horizontal nozzle is connected to a furnace, and a 2-4 level pulverized coal concentration device is arranged in the primary air / pulverized coal horizontal nozzle; the beneficial effects of the utility model are as follows: using oxygen-enriched fuel gas ignition to strengthen the adaptability of coal types for ignition and stable combustion of a coal-fired boiler, improving the low-load stable combustion capability of the boiler, and improving the ignition and stable combustion performance of the pulverized coal when the coal quality used in the pulverized coal boiler of a thermal power unit deteriorates, the calorific value is reduced, the moisture content is increased, the ash content is increased, and the deep adjustment load requirement of the boiler is further reduced, thereby enhancing the coal type adaptability and deep adjustment capability of the boiler.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler burners, in particular to an oxygen-enriched fuel gas ignition and boiler stable combustion burner for a pulverized coal boiler. Background Art

[0002] Coal-fired thermal power generating units play a ballast role in the safe and stable operation of the national power grid. However, in order to meet the needs of absorbing more wind power, photovoltaic and other new energy electricity, the power grid has higher and higher requirements for the peak load regulation capacity of coal-fired units, and the deep regulation capacity is generally required to be reduced to 20-30% load condition of the boiler. In addition, the coal used for power generation is increasingly inclined to use low calorific value, high moisture, high ash content and other types of coal that are not conducive to ignition and burnout, which makes it more difficult to stabilize the combustion of boilers and adjust the low load deep regulation.

[0003] At present, the existing ignition and stable combustion technologies for boilers include plasma ignition burners, micro-oil ignition burners and oxygen-rich micro-oil ignition burners. Plasma ignition technology has poor adaptability to lean coal and other coal types with low volatile matter, while micro-oil ignition technology has a small fuel adjustment range and cannot flexibly adjust the output quickly and in large proportions according to the characteristics of the coal to meet the actual needs of ignition and stable combustion. Utility Model Content

[0004] In order to overcome the above problems existing in the prior art, the utility model provides a pulverized coal boiler oxygen-enriched fuel gas ignition and boiler stable combustion burner.

[0005] The utility model discloses an oxygen-enriched fuel gas ignition and boiler stable combustion burner for a pulverized coal boiler, comprising a primary air / pulverized coal elbow, a primary air / pulverized coal horizontal nozzle and an oxygen-enriched ignition stable combustion gun, wherein one end of the primary air / pulverized coal elbow inlet is connected to a pulverized coal pipeline, and the other end is connected to the primary air / pulverized coal horizontal nozzle, and the outlet end of the primary air / pulverized coal horizontal nozzle is connected to a furnace, and a 2-4-stage pulverized coal concentrating device is arranged in the primary air / pulverized coal horizontal nozzle, and the pulverized coal concentrating device comprises an inlet concentrating section, a central first-stage concentrating cylinder, a central second-stage concentrating cylinder and a central third-stage concentrating cylinder.

[0006] On this basis, the cross-sections of the inlet concentration section and the central first-level concentration cylinder are circular structures, the central longitudinal section of the inlet concentration section is a contracted structure, and the central longitudinal section of the central first-level concentration cylinder is a front and rear horizontal section plus an expanded cone structure.

[0007] On this basis, the cross-section of the central secondary concentrator and the central tertiary concentrator is a circular or elliptical structure, and the longitudinal section of the central secondary concentrator and the central tertiary concentrator is a horizontal section with equal diameters at both ends plus a central necked concentrating structure.

[0008] On this basis, the oxygen-enriched ignition and stabilizing gas gun is inserted from the primary air / coal powder elbow, the front end of the oxygen-enriched ignition and stabilizing gas gun is inserted into the central first-level concentrator, and the horizontal direction of the oxygen-enriched ignition and stabilizing gas gun is aligned with the center line of the primary air / coal powder horizontal nozzle.

[0009] On this basis, the oxygen-enriched ignition and combustion stabilizing gas gun is composed of three concentric sleeves, and the oxygen-enriched ignition and combustion stabilizing gas gun includes a coal powder oxygen-enriched nozzle, a fuel gas oxygen-enriched nozzle and a fuel gas nozzle. The coal powder oxygen-enriched nozzle is located in the outermost layer, the fuel gas oxygen-enriched nozzle is the middle layer, and the fuel gas nozzle is the innermost layer.

[0010] On this basis, the gas oxygen-enriched nozzle nozzle end includes an expansion segment, the gas nozzle nozzle end is placed in the gas oxygen-enriched nozzle nozzle expansion segment, and the pulverized coal oxygen-enriched nozzle nozzle end is at the rear end of the gas oxygen-enriched nozzle expansion segment.

[0011] On this basis, the diameter of the expanded end of the gas oxygen-enriched nozzle is the same as the outer diameter of the pulverized coal oxygen-enriched nozzle.

[0012] Compared with the prior art, the utility model has the following beneficial effects: the adaptability of coal types for ignition and stable combustion of coal-fired boilers is enhanced by ignition with oxygen-enriched fuel gas, and the low-load stable combustion capability of the boiler is improved; the fuel gas and the oxygen-enriched gas from the fuel gas oxygen-enriched nozzle are premixed and ignited and burned in the expanded cone section at the nozzle end of the fuel gas oxygen-enriched nozzle to form an initial ignition flame; the nozzle end of the pulverized coal oxygen-enriched nozzle is at the rear end of the expanded cone section of the fuel gas oxygen-enriched nozzle, and the pulverized coal airflow entering the central primary concentrator is sprayed outside the expanded cone tube to increase the oxygen concentration of the pulverized coal airflow in this area, and the oxygen-enriched fuel gas flame of the initial ignition and burning is wrapped in the central primary concentrator; the primary air / pulverized coal airflow in the central primary concentrator is heated by the initial fuel gas ignition airflow and then rises The primary air / coal powder airflow in the central secondary concentrator is heated and ignited, and the combustion flue gas ejected from the central secondary concentrator enters the central tertiary concentrator, heats and ignites the primary air / coal powder airflow in the central tertiary concentrator. Finally, the primary air / coal powder airflow ignited at the burner outlet center is sprayed into the furnace under the wrapping of the outer light-phase primary air / coal powder airflow, forming a stable combustion flame in the furnace. When the coal quality of the pulverized coal boiler of the thermal power unit deteriorates, the calorific value is reduced, the moisture content is increased, the ash content is increased, and the deep adjustment load requirement of the boiler is further reduced, the ignition and stable combustion performance of the pulverized coal is improved, and the coal type adaptability and deep adjustment capability of the boiler are enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of the burner of the utility model;

[0014] Figure 2 This is a schematic diagram of the head structure of the oxygen-enriched ignition and combustion-stabilizing gas gun of the utility model;

[0015] In the figure: 1. primary air / coal powder elbow, 2. primary air / coal powder horizontal nozzle, 3. oxygen-enriched ignition and gas stabilizing gun, 3-1. coal powder oxygen-enriched nozzle, 3-2. gas oxygen-enriched nozzle, 3-3. gas nozzle, 4. inlet concentrating section, 5. center first-stage concentrating cylinder, 6. center second-stage concentrating cylinder, 7. center third-stage concentrating cylinder. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] The utility model discloses a pulverized coal boiler oxygen-enriched gas ignition and boiler stable combustion burner, referring to Figure 1 and Figure 2 , including a primary air / coal powder elbow 1, a primary air / coal powder horizontal nozzle 2 and an oxygen-enriched ignition and combustion stabilizing gun 3. One end of the inlet of the primary air / coal powder elbow 1 is connected to the coal powder pipeline, and the other end is connected to the primary air / coal powder horizontal nozzle 2. The outlet end of the primary air / coal powder horizontal nozzle 2 is connected to the furnace. A 2-4-stage coal powder concentration device is arranged in the primary air / coal powder horizontal nozzle 2. In this embodiment, three stages are arranged. The coal powder concentration device includes an inlet concentration section 4, a central first-stage concentration cylinder 5, a central second-stage concentration cylinder 6 and a central third-stage concentration cylinder 7.

[0018] According to the ignition difficulty of the coal types, the central secondary concentrator 6 and the central tertiary concentrator 7 are non-essential structures. For coal types that are easy to ignite, the central secondary concentrator 6 and the central tertiary concentrator 7 may not be set. For coal types with poor ignition characteristics, the central secondary concentrator 6 needs to be added, and for coal types with even worse ignition characteristics, the central tertiary concentrator 7 needs to be added. In the present embodiment, all three levels are set.

[0019] As a preferred embodiment of the utility model, in this embodiment, the cross-section of the inlet concentrating section 4 and the central primary concentrating tube 5 is a circular structure, the central longitudinal section of the inlet concentrating section 4 is a constricted structure, and the central longitudinal section of the central primary concentrating tube 5 is a front and rear horizontal section plus a flared cone structure; the cross-section of the central secondary concentrating tube 6 and the central tertiary concentrating tube 7 is a circular or elliptical structure, and the longitudinal section of the central secondary concentrating tube 6 and the central tertiary concentrating tube 7 is a horizontal section with equal diameters at both ends plus a central constricted concentrating structure. The specific shape can be adjusted according to the cross-sectional size of the primary air / coal powder horizontal nozzle 2.

[0020] As a preferred embodiment of the utility model, in this embodiment, the oxygen-enriched ignition and gas stabilizing gun 3 is inserted from the primary air / coal powder elbow 1, the front end of the oxygen-enriched ignition and gas stabilizing gun 3 is inserted into the center first-level concentrator 5, and the oxygen-enriched ignition and gas stabilizing gun 3 is horizontally aligned with the center line of the primary air / coal powder horizontal nozzle 2.

[0021] As a preferred embodiment of the utility model, in this embodiment, the oxygen-enriched ignition and stabilizing gas gun 3 is composed of three concentric sleeves, and the oxygen-enriched ignition and stabilizing gas gun 3 includes a coal powder oxygen-enriched nozzle 3-1, a gas oxygen-enriched nozzle 3-2 and a gas nozzle 3-3. The coal powder oxygen-enriched nozzle 3-1 is located at the outermost layer, the gas oxygen-enriched nozzle 3-2 is the middle layer, and the gas nozzle 3-3 is the innermost layer. The diameter of the expanded end of the gas oxygen-enriched nozzle 3-2 is the same as the outer diameter of the coal powder oxygen-enriched nozzle 3-1.

[0022] As a preferred embodiment of the utility model, in this embodiment, the nozzle end of the gas oxygen-enriched nozzle 3-2 includes an expansion segment, the nozzle end of the gas oxygen-enriched nozzle 3-3 is placed in the nozzle expansion segment of the gas oxygen-enriched nozzle 3-2, and the nozzle end of the pulverized coal oxygen-enriched nozzle 3-1 is at the rear end of the expansion segment of the gas oxygen-enriched nozzle 3-2.

[0023] The fuel gas and the oxygen-enriched gas from the fuel gas oxygen-enriched nozzle are premixed and ignited in the expanded cone section at the nozzle end of the fuel gas oxygen-enriched nozzle 3-2 to form an initial ignition flame. The nozzle end of the pulverized coal oxygen-enriched nozzle 3-1 is at the rear end of the expanded cone section of the fuel gas oxygen-enriched nozzle 3-2, and the pulverized coal airflow entering the central first-level concentrator 5 is sprayed outside the expanded cone to increase the oxygen concentration of the pulverized coal airflow in this area, and the initial ignition and burning oxygen-enriched fuel gas flame is wrapped in the central first-level concentrator 5. The primary air / pulverized coal airflow in the central first-level concentrator 5 is heated by the initial fuel gas ignition airflow and then burns at a higher temperature, and enters the central second-level concentrator 6 to heat and ignite the primary air / pulverized coal airflow in the central second-level concentrator 6. The combustion flue gas ejected from the central second-level concentrator 6 enters the central third-level concentrator 7 to heat and ignite the primary air / pulverized coal airflow in the central third-level concentrator 7. Finally, the primary air / pulverized coal airflow ignited at the center of the burner outlet is sprayed into the furnace wrapped by the outer light-phase primary air / pulverized coal airflow, forming a stable combustion flame in the furnace.

[0024] The utility model can improve the ignition and stable combustion performance of pulverized coal and enhance the coal type adaptability and deep adjustment capability of the boiler when the coal quality used in the pulverized coal boiler of a thermal power unit deteriorates, the calorific value is reduced, the moisture content is increased, the ash content is increased, and the deep adjustment load requirement of the boiler is further reduced.

[0025] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation", "screwing", "pad installation" 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 or an electrical connection; 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, ordinary technicians in this field can understand the specific meanings of the above terms in the utility model according to the specific circumstances.

[0027] The above description shows and describes the preferred embodiments of the utility model. As mentioned above, it should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the utility model concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A pulverized coal boiler oxygen-enriched gas ignition and boiler stable combustion burner, characterized in that: The invention comprises a primary air / coal powder elbow (1), a primary air / coal powder horizontal nozzle (2) and an oxygen-enriched ignition and combustion stabilizing gun (3). One end of the inlet of the primary air / coal powder elbow (1) is connected to a coal powder pipeline, and the other end is connected to the primary air / coal powder horizontal nozzle (2). The outlet end of the primary air / coal powder horizontal nozzle (2) is connected to a furnace. A 2-4-stage coal powder concentration device is arranged in the primary air / coal powder horizontal nozzle (2). The coal powder concentration device comprises an inlet concentration section (4), a central first-stage concentration cylinder (5), a central second-stage concentration cylinder (6) and a central third-stage concentration cylinder (7).

2. The pulverized coal boiler oxygen-enriched gas ignition and boiler combustion stabilization burner according to claim 1, characterized in that: The cross-sections of the inlet concentration section (4) and the central first-level concentration cylinder (5) are circular structures. The central longitudinal section of the inlet concentration section (4) is a constricted structure, and the central longitudinal section of the central first-level concentration cylinder (5) is a front and rear horizontal section plus an expanded cone structure.

3. The pulverized coal boiler oxygen-enriched gas ignition and boiler combustion stabilization burner according to claim 1, characterized in that: The cross-sections of the central secondary concentrator (6) and the central tertiary concentrator (7) are circular or elliptical structures, and the longitudinal sections of the central secondary concentrator (6) and the central tertiary concentrator (7) are horizontal sections with equal diameters at both ends and a central constriction concentrating structure.

4. The pulverized coal boiler oxygen-enriched gas ignition and boiler combustion stabilization burner according to claim 2, characterized in that: The oxygen-enriched ignition and stabilizing gas gun (3) is inserted from the primary air / coal powder elbow (1), the front end of the oxygen-enriched ignition and stabilizing gas gun (3) is inserted into the center first-level concentrator (5), and the oxygen-enriched ignition and stabilizing gas gun (3) is horizontally aligned with the center line of the primary air / coal powder horizontal nozzle (2).

5. The pulverized coal boiler oxygen-enriched gas ignition and boiler combustion stabilization burner according to claim 3, characterized in that: The oxygen-enriched ignition and stabilizing combustion gun (3) is composed of three concentric sleeves, and the oxygen-enriched ignition and stabilizing combustion gun (3) comprises a coal powder oxygen-enriched nozzle (3-1), a fuel gas oxygen-enriched nozzle (3-2) and a fuel gas nozzle (3-3), wherein the coal powder oxygen-enriched nozzle (3-1) is located at the outermost layer, the fuel gas oxygen-enriched nozzle (3-2) is the middle layer, and the fuel gas nozzle (3-3) is the innermost layer.

6. The pulverized coal boiler oxygen-enriched gas ignition and boiler combustion stabilization burner according to claim 5, characterized in that: The nozzle end of the gas oxygen-enriched nozzle (3-2) comprises an expanded conical section, the nozzle end of the gas oxygen-enriched nozzle (3-3) is placed in the expanded conical section of the gas oxygen-enriched nozzle (3-2), and the nozzle end of the pulverized coal oxygen-enriched nozzle (3-1) is at the rear end of the expanded conical section of the gas oxygen-enriched nozzle (3-2).

7. The pulverized coal boiler oxygen-enriched gas ignition and boiler combustion stabilization burner according to claim 5, characterized in that: The diameter of the expanded end of the nozzle of the fuel gas oxygen-enriched nozzle (3-2) is the same as the outer diameter of the pulverized coal oxygen-enriched nozzle (3-1).

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