Micro-oxygen-enriched combustor

Abstract

The invention relates to the field of combustors, and discloses a micro-oxygen-enriched combustor which comprises a central primary air spray pipe, a central secondary air spray pipe and a combustion chamber, the central primary air spray pipe is communicated with the combustion chamber, and an oscillation cavity is formed between the central primary air spray pipe and the combustion chamber so as to spray fuel gas introduced by the central primary air spray pipe into the combustion chamber; the plurality of secondary air spray pipes are arranged outside the central primary air spray pipe in a surrounding manner and are communicated with the hearth; and the primary air adjusting spray pipe is communicated with the hearth and is used for introducing oxygen. According to the technical scheme, the oscillation cavity enables fuel gas introduced into the hearth to generate oscillation jet flow, the stability of the mixing and combustion process is remarkably improved, meanwhile, micro-oxygen-enriched combustion also gives consideration to balance of operation cost and performance improvement, the device is particularly suitable for improving the combustion stability in low-load operation of a coal-fired power plant, and the service life of the device is prolonged. The combustion stability can be effectively improved, the fuel utilization rate is high, pollutant emission is reduced, and equipment damage is reduced.

Description

Technical Field

[0001] The invention relates to the field of burners, in particular to a micro-oxygen-enriched burner. Background Art

[0002] With the large-scale development of new energy, its intermittent, random and volatile characteristics have put forward huge demands on the system regulation capabilities. As the basic guarantee power source in the power system, coal-fired power plants bear more flexible regulation responsibilities, balancing the load changes of the power grid through peak regulation to ensure the stable operation of the power system. Therefore, it is necessary to balance the load changes of the power grid by reducing the combustion load.

[0003] The burners in the prior art are unstable in low-load combustion, which leads to reduced fuel utilization, increased pollutant emissions, and even equipment damage or safety accidents. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem in the prior art that the burner is unstable in low-load combustion, resulting in reduced fuel utilization, increased pollutant emissions, and even equipment damage or safety accidents.

[0005] In order to achieve the above object, the present invention provides a micro-oxygen-enriched burner, comprising:

[0006] A central primary air nozzle is connected to the furnace, and an oscillation cavity is provided between the central primary air nozzle and the furnace to spray the gas introduced by the central primary air nozzle into the furnace;

[0007] Secondary air nozzles, a plurality of secondary air nozzles are arranged around the central primary air nozzle and connected to the furnace; and,

[0008] The primary air regulating nozzle is connected to the furnace and is used for introducing oxygen.

[0009] In some embodiments, the oscillation cavity includes a primary oscillation cavity and a secondary oscillation cavity which are sequentially connected between the central primary air nozzle and the furnace.

[0010] In some embodiments, the ratio of the diameter of the central primary air nozzle to that of the primary oscillation cavity is 0.2 to 0.5, and the ratio of the diameter of the primary oscillation cavity to that of the secondary oscillation cavity is 0.6 to 0.8.

[0011] In some embodiments, the ratio of the length to the diameter of the primary oscillation cavity is 1.5-3, and the ratio of the length to the diameter of the secondary oscillation cavity is 1.5-3.

[0012] In some embodiments, a hole plate is provided at the outlet of the primary oscillation cavity to form an oscillating jet.

[0013] In some embodiments, the primary air regulating nozzles are arranged on both sides of the central primary air nozzle and are connected to the outlet of the central primary air nozzle.

[0014] In some embodiments, the secondary air nozzle includes an inner secondary air nozzle and an outer secondary air nozzle radially spaced from each other, the inner secondary air nozzle and the outer secondary air nozzle are respectively arranged outside the central primary air nozzle, and an outer secondary air oscillation cavity is provided between the outer secondary air nozzle and the furnace.

[0015] In some embodiments, the ratio of the diameter of the outer secondary air nozzle to the diameter of the outer secondary air oscillation cavity is 0.2-0.5, and the ratio of the length to the diameter of the outer secondary air oscillation cavity is 2-5.

[0016] In some embodiments, the number of inner secondary air nozzles is 2 to 6, and the number of outer secondary air nozzles is 2 to 4.

[0017] In some embodiments, the inlet flow velocity of the furnace is 60 m / s to 200 m / s.

[0018] Through the above technical scheme, the oscillating cavity causes the gas introduced into the furnace to produce an oscillating jet, periodically changing the speed, flow rate or direction of the jet fluid, producing a regular pulsation or swinging effect, making the transfer of heat and momentum more efficient. The vortex structure generated can significantly improve the stability of the mixing and combustion process. At the same time, the slightly oxygen-enriched combustion also takes into account the balance between operating costs and performance improvement. It is particularly suitable for improving combustion stability during low-load operation of coal-fired power plants. It can effectively improve combustion stability, high fuel utilization, reduce pollutant emissions and reduce equipment damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional view of a micro-oxygen-enriched burner according to an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 Section view of the AA plane.

[0021] Description of Reference Numerals

[0022] 1. Central primary air nozzle; 2. Inner secondary air nozzle; 3. Outer secondary air nozzle; 4. Outer secondary air oscillation cavity; 5. Primary oscillation cavity; 6. Orifice plate; 7. Secondary oscillation cavity; 8. Primary air regulating nozzle. DETAILED DESCRIPTION

[0023] The following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments of the invention herein, but includes all technical solutions falling within the scope of the claims.

[0024] The present invention provides these embodiments to make the present invention thorough and complete, and fully express the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, rather than as limiting.

[0025] It should be noted that, in the description of the present invention, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, 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 cannot be understood as a limitation on the present invention. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0026] In addition, the words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" is not strictly perpendicular, but is within the tolerance range. "Parallel" is not strictly parallel, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0027] It should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0028] All terms used in the present invention have the same meanings as those understood by ordinary technicians in the field to which the present invention belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0029] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0030] In order to solve the problem that the burner in the prior art is unstable in low-load combustion, resulting in reduced fuel utilization, increased pollutant emissions, and even equipment damage or safety accidents, the present invention provides a micro-oxygen-enriched burner, such as Figure 1 As shown, the slightly oxygen-enriched burner includes: a central primary air nozzle 1, which is connected to the furnace and is used to introduce fuel gas. An oscillation cavity is provided between the central primary air nozzle 1 and the furnace. After passing through the oscillation cavity, the fuel gas is excited to be oscillating fuel gas and sprayed into the furnace, so that it is more fully mixed with other gases, burns more completely, and has a high fuel utilization rate; a secondary air nozzle, a plurality of secondary air nozzles are arranged outside the central primary air nozzle 1 and are connected to the furnace, and are used to introduce the required air for subsequent combustion into the furnace; and a primary air regulating nozzle 8, which is connected to the furnace and is used to introduce oxygen, so that the oxygen concentration in the furnace is appropriately increased to reach a slightly oxygen-enriched state (the oxygen concentration is generally 21% to 30%), so that the introduced fuel gas can burn more fully and reduce the polluting exhaust gas generated by incomplete combustion. Through the above technical scheme, the oscillating cavity causes the gas introduced into the furnace to produce an oscillating jet, periodically changing the speed, flow rate or direction of the jet fluid, producing a regular pulsation or swinging effect, making the transfer of heat and momentum more efficient. The vortex structure generated can significantly improve the stability of the mixing and combustion process. At the same time, the slightly oxygen-enriched combustion also takes into account the balance between operating costs and performance improvement. It is particularly suitable for improving combustion stability during low-load operation of coal-fired power plants. It can effectively improve combustion stability, high fuel utilization, reduce pollutant emissions and reduce equipment damage.

[0031] In some embodiments, Figure 1 As shown, the oscillation cavity includes a primary oscillation cavity 5 and a secondary oscillation cavity 7 which are sequentially connected between the central primary air nozzle 1 and the furnace. The primary air in the central primary air nozzle 1 passes through the primary oscillation cavity 5 and the secondary oscillation cavity 7 in sequence, and oscillates twice, further strengthening the primary air to generate an oscillating jet, so that the gas distribution in the furnace is more uniform, and the gas and oxygen are more fully mixed, so as to burn more fully.

[0032] In some embodiments, in order to stimulate the formation of oscillating gas and achieve a better oscillating injection effect, the diameter ratio of the central primary air nozzle 1 to the primary oscillation cavity 5 is preferably 0.2-0.5, to avoid the inlet cross-sectional area of ​​the primary oscillation cavity 5 being too small or too large, which affects the formation of oscillating gas. The diameter ratio of the primary oscillation cavity 5 to the secondary oscillation cavity 7 is preferably 0.6-0.8, to avoid the inlet cross-sectional area of ​​the secondary oscillation cavity 7 being too small or too large, which affects the further aggravation of the oscillating gas.

[0033] In some embodiments, the ratio of the length to the diameter of the primary oscillation cavity 5 is 1.5-3, and the ratio of the length to the diameter of the secondary oscillation cavity 7 is 1.5-3, which provide suitable excitation conditions for the formation of oscillating combustion gas.

[0034] In some embodiments, Figure 1 and Figure 2 As shown, the orifice plate 6 is arranged at a position near the outlet of the inner wall of the primary oscillation cavity 5, and the orifice plate 6 is formed at the outlet of the primary oscillation cavity 5 as a channel with an inner diameter smaller than that of the primary oscillation cavity 5 and a square cross section, which is used to promote the formation of an oscillating jet. Orifice plates 6 of other shapes can also be provided to set the channel cross section to different shapes, such as setting the cross section to a triangle, etc., and by providing channels of different shapes to promote the formation of oscillating jets to different degrees, which can be flexibly adjusted according to actual conditions.

[0035] In some embodiments, Figure 1 As shown, the primary air regulating nozzle 8 is arranged on both sides of the central primary air nozzle 1 and is connected to the outlet of the central primary air nozzle 1. A valve is arranged at the inlet of the primary air regulating nozzle 8 to adjust the amount of input oxygen. The primary air regulating nozzle 8 is used to mix the primary air and oxygen, adjust the oxygen concentration of the primary air, and thus adjust the oxygen concentration in the furnace as a whole to form a slightly oxygen-enriched combustion environment. At the same time, the setting position of the primary air regulating nozzle 8 enables the primary air regulating nozzle 8 to adjust the shape of the gas sprayed from the central primary air nozzle 1. The oxygen in the primary air regulating nozzle 8 collides and mixes with the gas of the central primary air nozzle 1 at the outlet of the central primary air nozzle 1, further aggravating the oscillation injection effect in the primary oscillation cavity 5. The oxygen introduced into the primary air regulating nozzle 8 can use oxygen as a byproduct of other new energy production processes, such as the oxygen byproduct of solar photovoltaic hydrogen production can be connected to the oxygen-enriched burner of the present invention.

[0036] In some embodiments, Figure 1 and Figure 2As shown, the secondary air nozzle includes an inner secondary air nozzle 2 and an outer secondary air nozzle 3 radially spaced from each other. The inner secondary air nozzle 2 and the outer secondary air nozzle 3 are respectively spaced outside the central primary air nozzle 1 and provide air to the furnace. Among them, the inner secondary air nozzle 2 provides additional air for the combustion process to ensure that the gas in the furnace can be completely burned. An outer secondary air oscillation cavity 4 is provided between the outer secondary air nozzle 3 and the furnace. The air introduced by the outer secondary air nozzle 3 passes through the outer secondary air oscillation cavity 4, generates an oscillating jet and is sprayed into the furnace, further strengthening the gas mixing in the furnace, making the gas burn more fully, and improving the combustion stability.

[0037] In some embodiments, the diameter ratio of the outer secondary air nozzle 3 to the outer secondary air oscillation cavity 4 is preferably 0.2-0.5, and the length-diameter ratio of the outer secondary air oscillation cavity 4 is 2-5, so as to stimulate a more violent oscillating jet.

[0038] In some embodiments, the number of the inner secondary air nozzles 2 is 2 to 6, and the number of the outer secondary air nozzles 3 is 2 to 4. Figure 2 The figure shows the case where the number of inner secondary air nozzles 2 is 2 and the number of outer secondary air nozzles 3 is 2. When the number of inner secondary air nozzles 2 is greater than 2 and less than or equal to 6, and the number of outer secondary air nozzles 3 is greater than 2 and less than or equal to 4, the inner secondary air nozzles 2 and the outer secondary air nozzles 3 can be arranged arbitrarily along the circumference of the central primary air nozzle 1.

[0039] In some embodiments, Figure 1 As shown, the outlets of the secondary oscillation cavity 7, the inner secondary air nozzle 2, and the outer secondary air oscillation cavity 4 are flush with the furnace, and the flow velocity is 60m / s~200m / s, that is, the inlet flow velocity of the furnace is 60m / s~200m / s. The amount of gas introduced can be adjusted according to actual needs to control the combustion intensity of the micro-oxygen-enriched burner.

[0040] The working process of the oxygen-enriched burner provided by the preferred embodiment of the present invention is specifically described below:

[0041] The gas introduced into the central primary air nozzle 1 collides and mixes with the oxygen introduced into the primary air regulating nozzle 8 at the outlet of the central primary air nozzle 1, and enters the primary oscillation cavity 5 to generate an oscillating jet. When passing through the channel at the orifice plate 6 near the outlet of the primary oscillation cavity 5 and the secondary oscillation cavity 7 in sequence, an oscillating jet is further generated and sprayed into the furnace. At this time, the mixing of the gas and oxygen is more complete. The air introduced into the outer secondary air nozzle 3 generates an oscillating jet after passing through the outer secondary air oscillation cavity 4 and is sprayed into the furnace. In the furnace, the mixed gas of gas and oxygen from the secondary oscillation cavity 7 is sprayed into the furnace, and the outer secondary air oscillation cavity 4 is sprayed into the furnace and fully mixed with the air introduced into the furnace by the inner secondary air nozzle 2, which increases the contact area between the gas and the air, promotes the full combustion of the gas in a slightly oxygen-enriched state, improves the combustion stability, reduces pollutant emissions, and is more suitable for low-load combustion.

[0042] So far, various embodiments of the present invention have been described in detail. In order to avoid obscuring the concept of the present invention, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution invented here.

[0043] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A micro oxygen-enriched burner, characterized in that: include: A central primary air nozzle (1), the central primary air nozzle (1) being in communication with the furnace, and an oscillation cavity being provided between the central primary air nozzle (1) and the furnace, so as to spray the fuel gas introduced through the central primary air nozzle (1) into the furnace; Secondary air nozzles, a plurality of which are arranged outside the central primary air nozzle (1) and are connected to the furnace; and A primary air regulating nozzle (8), the primary air regulating nozzle (8) is connected to the furnace and is used to introduce oxygen.

2. The micro-oxygen-enriched burner according to claim 1, characterized in that: The oscillation cavity comprises a primary oscillation cavity (5) and a secondary oscillation cavity (7) which are sequentially connected between the central primary air nozzle (1) and the furnace.

3. The micro-oxygen-enriched burner according to claim 2, characterized in that: The ratio of the diameter of the central primary air nozzle (1) to the diameter of the primary oscillation cavity (5) is 0.2 to 0.5, and the ratio of the diameter of the primary oscillation cavity (5) to the diameter of the secondary oscillation cavity (7) is 0.6 to 0.

8.

4. The micro-oxygen-enriched burner according to claim 2, characterized in that: The ratio of the length to the diameter of the primary oscillation cavity (5) is 1.5 to 3, and the ratio of the length to the diameter of the secondary oscillation cavity (7) is 1.5 to 3.

5. The micro-oxygen-enriched burner according to claim 2, characterized in that: An orifice plate (6) is provided at the outlet of the primary oscillation cavity (5) to form an oscillating jet.

6. The micro-oxygen-enriched burner according to claim 1, characterized in that: The primary air regulating nozzle (8) is arranged on both sides of the central primary air nozzle (1) and is connected to the outlet of the central primary air nozzle (1).

7. The micro-oxygen-enriched burner according to claim 1, characterized in that: The secondary air nozzle comprises an inner secondary air nozzle (2) and an outer secondary air nozzle (3) which are radially spaced from each other, wherein the inner secondary air nozzle (2) and the outer secondary air nozzle (3) are respectively arranged outside the central primary air nozzle (1), wherein an outer secondary air oscillation cavity (4) is provided between the outer secondary air nozzle (3) and the furnace.

8. The micro-oxygen-enriched burner according to claim 7, characterized in that: The ratio of the diameter of the external secondary air nozzle (3) to the diameter of the external secondary air oscillation cavity (4) is 0.2 to 0.5, and the ratio of the length to the diameter of the external secondary air oscillation cavity (4) is 2 to 5.

9. The micro-oxygen-enriched burner according to claim 7, characterized in that: The number of the inner secondary air nozzles (2) is 2 to 6, and the number of the outer secondary air nozzles (3) is 2 to 4.

10. The micro-oxygen-enriched burner according to claim 1, characterized in that: The inlet flow velocity of the furnace is 60m / s to 200m / s.

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