CN111623348A - Porous ceramic combustion head for low-nitrogen combustor - Google Patents

Abstract

The invention discloses a porous ceramic combustion head for a low-nitrogen burner, comprising a combustion head casing and an inner air duct; a fire orifice plate is provided at the top opening of the combustion head casing, and the fire orifice plate comprises at least two Porous medium ceramic plates, the inner side of each porous medium ceramic plate is provided with an inner protective plate with holes; the inner air duct is inserted into the combustion head casing, and the surface of the inner air duct is provided with a plurality of ventilation ports. The combustion head of the invention has high combustion efficiency, low CO and NOx emissions, dual anti-tempering protection functions, reliable safety performance, uniform airflow distribution, uniform fuel premixing, and stable combustion conditions.

Description

A kind of porous ceramic combustion head for low nitrogen burner

technical field

The invention relates to the technical field of gas burners, in particular to a porous ceramic combustion head for a low-nitrogen burner.

Background technique

At present, the heat load of vertical heating furnaces on the market is mainly below 1MW, and most of them are equipped with simple partial premixed gas burners. When using, it is necessary to manually adjust the gas valve and the air distribution mechanism, and manually adjust the air-fuel ratio. The fuel is often burned in the case of unreasonable excess air coefficient, the combustion is insufficient or the exhaust gas temperature is too high, and the fuel is not used reasonably. On the one hand, energy is wasted. Most of them are ejector structures, the primary air supply is insufficient, the secondary air supply is uneven, the flame is long, the flue gas flow rate is fast, the residence time in the furnace is short, and the amount of pollutants generated is large.

With the increasingly prominent environmental problems, the formulation of relevant domestic and foreign gas fuel combustion appliance standards, and the implementation of nitrogen oxide control measures by government environmental protection departments, more and more low-nitrogen combustion technologies are also applied to the field of combustion technology. At present, the nitrogen reduction methods used by low-nitrogen burners on the market include flue gas recirculation technology and full premix combustion technology. Flue gas recirculation technology is mainly used in larger gas boilers, while small gas heating furnaces mainly use full premix combustion technology. Full premixed combustion refers to fully mixing the gas and all the required air before the burner's fire hole, and then performing rapid and complete combustion after the fire hole. The combustion speed of full premixed combustion is fast, the combustion is complete, and the overall temperature of the flame is lower than that of the inner flame of partial premixed combustion, and the emission of nitrogen oxides is low. At present, the complete premixed burners at home and abroad are mostly flat and cylindrical. Among them, the fire hole media of the flat burner are mostly metal fiber materials and porous ceramic plate materials. In practical applications, the former is expensive. If it is partially blocked, it may be damaged by oxidation and corrosion when used in a high temperature environment for a long time. The latter Low hardness, easy to chip, and risk of tempering if damaged, therefore, the wide application of both is limited.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a kind of porous ceramic combustion head for complete premixed low nitrogen burner with natural gas as fuel, high combustion efficiency and low nitrogen emission, so as to solve the problem of the existing flat plate with porous ceramic plate as fire hole medium. The technical problems existing in the type burner.

In order to achieve the above objects, the technical solutions adopted in the present invention are as follows.

A porous ceramic combustion head for a low-nitrogen burner, comprising a combustion head casing and an inner air duct; a fire orifice plate is provided at the top opening of the combustion head casing, and the fire orifice plate comprises at least two porous medium ceramic plates The inner side of each porous medium ceramic plate is provided with an inner protective plate with holes; the inner air duct is inserted into the combustion head casing, and a plurality of ventilation openings are arranged on the surface of the inner air duct.

Further, the combustion head housing 1 is mainly composed of a front end plate 13 , an upper plate 14 , a lower plate 15 and a rear end plate 16 ; the inner air duct 2 is inserted into the through hole opened on the front end plate 13 The combustion head casing 1 is in a sealed connection with the front end plate 13 ; the upper plate 14 is provided with at least two openings, and the inner protection plate 4 is arranged on the upper plate 14 from the inner side. At the opening, the porous medium ceramic plate 3 is disposed at the opening from the outside of the upper plate 14 ; the rear end plate 16 is provided with one or more drainage holes.

Further, the upper plate 14 includes two top surfaces at an included angle, each top surface is provided with one or more openings, and the outer side of each opening is provided with one or more porous medium ceramic plates 3, each One or more inner protective plates 4 are arranged on the inner side of each opening.

Further, the edge of the porous dielectric ceramic plate 3 is provided with a fire guide 8, and the fire guide 8 is provided with a circular heat dissipation hole or a strip heat dissipation hole.

Further, the fire guide sheet 8 includes a first fire guide sheet 81 and a second fire guide sheet 82, which are respectively located on the tops of the two top surfaces.

Further, the porous dielectric ceramic plate 3 is fixed on the upper plate 14 by several pressing plates, and the connection between the porous dielectric ceramic plate 3 and the upper plate 14 is sealed with high temperature resistant glue.

Further, round holes and/or strip holes are densely arranged on the inner protective plate 4 .

Further, the inner air duct 2 includes an air outlet duct 10 at the front end and a connection duct 12 at the rear end, the air outlet duct 10 is located inside the combustion head casing 1, and the connection cylinder 12 is located in the combustion head casing. Outside the body 1 , a mounting flange 11 is provided at the end of the connecting cylinder 12 , and the plurality of ventilation openings 17 are arranged on the surface of the air outlet duct 10 in close arrangement.

Further, from the front end of the inner air duct 2 to the rear end, the apertures of the plurality of ventilation openings 17 gradually increase.

Further, the total opening area of the plurality of vents 17 is equivalent to the inlet area of the mounting flange 11 .

As can be seen from the above technical solutions, the embodiments of the present invention have the following advantages:

The combustion head of the invention has the advantages of compact structure, high combustion efficiency and low CO and NOx emissions.

In the combustion head of the present invention, the fire hole plate set on the fire hole surface includes two or more porous medium ceramic plates, the number of porous medium ceramic plates can be adjusted according to the required heat load, and the number of single porous medium ceramic plates can be reduced. It can effectively reduce the cracking of the fire orifice plate due to thermal stress deformation caused by temperature increase. In addition, an internal protective plate is arranged under the porous dielectric ceramic plate, and the double-layer structure formed together can realize double anti-tempering protection function. , the safety performance is more reliable.

The combustion head of the present invention is provided with an inner air duct, which can realize uniform distribution of air flow under variable load conditions, and promote uniform premixing of fuel. By using the burner of the present invention, the combustion mode of complete premixing of gaseous fuel can be realized, and the combustion condition is stable .

It can be seen from the above that the combustion head of the present invention has high combustion efficiency, low CO and NOx emissions, dual anti-backlash protection functions, reliable safety performance, uniform airflow distribution, uniform fuel premixing, and stable combustion conditions. The combustion head of the present invention can be used not only in small and medium-sized industrial heating systems, but also in domestic and commercial heating and domestic hot water supply systems.

Description of drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that are used in the description of the embodiments and the prior art. Obviously, the drawings in the following description are only some implementations of the present invention. For example, for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of a porous ceramic combustion head for a low-nitrogen burner in an embodiment of the present invention;

2 is a schematic structural diagram of a combustion head housing in an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an inner air duct in an embodiment of the present invention.

Detailed ways

In order to make those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only Embodiments are part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The terms "first", "second", "third" and the like in the description and claims of the present invention and the above drawings are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes For other steps or units inherent to these processes, methods, products or devices.

A detailed description will be given below through specific embodiments.

Referring to FIGS. 1 to 3 , an embodiment of the present invention provides a porous ceramic combustion head for a low-nitrogen burner (hereinafter referred to as a combustion head).

The combustion head includes a combustion head casing 1 and an inner air duct 2; a fire orifice plate is provided at the top opening of the combustion head casing 1, and the fire orifice plate includes at least two porous medium ceramic plates 3, each porous An inner protective plate 4 is arranged on the inner side of the dielectric ceramic plate 3 ; the inner air duct 2 is inserted into the combustion head housing 1 , and a plurality of ventilation ports 17 are provided on the surface of the inner air duct 2 .

Wherein, the fire orifice plate can adjust the number of porous medium ceramic plates 3 according to the required heat load, and change the area of a single porous medium ceramic plate. Both the porous medium ceramic plate 3 and the inner protection plate 4 have densely distributed through holes, allowing gas fuel to pass through. Optionally, through holes in the form of round holes and/or strip holes are densely arranged on the inner protective plate 4, and have the function of preventing tempering. Optionally, the width gap of the strip hole is between 0.5-1.5mm, the porosity of the strip hole is between 50%-60%, and the thickness is between 1-8mm; the diameter of the circular hole is between 1-2mm, and the porosity is between 1-2mm The rate is between 40%-60%; the thickness of the inner protection plate 4 is between 3-10mm.

The combustion head casing 1 is mainly composed of a front end plate 13 , an upper plate 14 , a lower plate 15 and a rear end plate 16 , and has a hollow cavity inside. The front end plate is provided with a through hole, and the inner air duct 2 is inserted into the combustion head casing 1 from the through hole opened on the front end plate 13 and is sealedly connected with the front end plate 13 . The upper plate 14 is provided with at least two openings to form a fire hole surface; the inner protection plate 4 is arranged at the openings from the inner side of the upper plate 14, and the porous medium ceramic plate 3 is inserted from the upper plate 14. The outer side of the plate 14 is arranged at the opening; the inner protective plate 4 and the porous dielectric ceramic plate 3 together constitute a double-layered fire orifice plate. The rear end plate 16 is provided with one or more drainage holes, such as 1-3 drainage holes.

Optionally, the upper plate 14 includes two top surfaces at an included angle, each top surface is provided with one or more openings, and the outer side of each opening is provided with one or more porous medium ceramic plates 3, One or more inner protective panels 4 are provided on the inner side of each opening.

Optionally, the porous medium ceramic plate 3 is fixed on the upper plate 14 by a plurality of pressing plates, the pressing plate may be provided with mounting holes, and is installed on the work 14 by bolts. Wherein, the pressing plate may include Z-shaped pressing plate 5 and several-shaped pressing plate 7 . The several-type pressing plate 7 is arranged between the two top surfaces, and has two pressing feet respectively used to fix the upper edges of the porous medium ceramic plates 3 provided on the two top surfaces. The Z-shaped pressing plates 5 are dispersedly arranged, and are respectively used to fix the lower edge, the left edge and the edge of the porous medium ceramic plate 3 .

Optionally, the connection between the porous dielectric ceramic plate 3 and the upper plate 14 is sealed with high temperature resistant glue to prevent the mixed gas from leaking from the edge and burning and damaging the metal frame of the surrounding combustion head casing. The high temperature resistant adhesive can be, for example, Shilin SL8081 high temperature resistant sealant.

Optionally, the edge of the porous medium ceramic plate 3 is provided with a fire guide 8, the fire guide is used to disturb the flame to stabilize the combustion, and a circular heat dissipation hole or a strip heat dissipation is provided on it. holes and fixing holes for mounting and fixing. Further, the fuse 8 includes a first fuse 81 and a second fuse 82, which are respectively located on the tops of the two top surfaces; a first fuse can be provided on both sides of the top of one of the top surfaces. The two sides of the top of the other top surface can be provided with a second to fire guide 82 respectively. Optionally, the fuse 8 can be installed on the Z-shaped pressing plate 5 through the opening fixing holes. Further, a heat insulating gasket 6 may be spaced between the fuse 8 and the Z-shaped pressing plate 5 .

Optionally, the inner air duct 2 includes an air outlet duct 10 at the front end and a connection duct 12 at the rear end, the air outlet duct 10 is located inside the combustion head housing 1, and the connection duct 12 is located in the combustion head housing. Outside the body 1 , the plurality of ventilation openings 17 are arranged in close arrangement on the surface of the air outlet duct 10 , and the end of the connecting duct 12 is provided with a mounting flange 11 . The connection between the connecting cylinder 12 and the mounting flange 11 and between the connecting cylinder 12 and the front end plate 13 of the combustion head housing 1 can be connected by welding.

Optionally, from the front end of the inner air duct 2 to the rear end, the apertures of the plurality of ventilation ports 17 gradually increase.

Optionally, the total opening area of the plurality of vents 17 is equivalent to the inlet area of the mounting flange 11 .

As above, the present invention discloses a porous ceramic combustion head for a low nitrogen burner, which mainly includes a combustion head casing 1, an inner air duct 2, a porous medium ceramic plate 3, an inner protective plate 4 and other components, and may further include a mounting flange 11. , pressure plate, fuse 8, thermal insulation gasket 6 and other components. Among them, other components except the heat insulating gasket 6 can be made of high temperature resistant stainless steel. When the combustion head is working, the gas fuel formed by the complete premixing of gas and air can enter the inner air duct 2 from the side of the mounting flange 11, enter the combustion head housing 1 through the vent 17 on the inner air duct 2, and then Combustion is carried out by overflowing through the through holes in the fire orifice plate. Among them, the fire orifice plate includes two layers of an inner protective plate 4 and a porous dielectric ceramic plate 3, which can realize double anti-tempering protection. The fire guide 8 is provided with round holes or strip-shaped heat dissipation holes, which are used for turbulent flames to stabilize combustion. The inner air duct 2 can match the required length of the inner air duct according to the length of the combustion head. The inner air duct 2 is provided with densely-discharged vents, and the aperture gradually increases from the inside to the outside. Realize uniform distribution of airflow under variable load conditions, and promote uniform premixing of fuel and air.

To sum up, the combustion head disclosed in the embodiments of the present invention achieves the following technical effects by adopting the above technical solutions.

The combustion head of the invention has the advantages of compact structure, high combustion efficiency and low CO and NOx emissions.

In the combustion head of the present invention, the fire hole plate set on the fire hole surface includes two or more porous medium ceramic plates, the number of porous medium ceramic plates can be adjusted according to the required heat load, and the number of single porous medium ceramic plates can be reduced. It can effectively reduce the cracking of the fire orifice plate due to thermal stress deformation caused by temperature increase. In addition, an internal protective plate is arranged under the porous dielectric ceramic plate, and the double-layer structure formed together can realize double anti-tempering protection function. , the safety performance is more reliable.

The combustion head of the present invention is provided with an inner air duct, which can realize uniform distribution of air flow under variable load conditions, and promote uniform premixing of fuel. By using the burner of the present invention, the combustion mode of complete premixing of gaseous fuel can be realized, and the combustion condition is stable .

It can be seen from the above that the combustion head of the present invention has high combustion efficiency, low CO and NOx emissions, dual anti-backlash protection functions, reliable safety performance, uniform airflow distribution, uniform fuel premixing, and stable combustion conditions. The combustion head of the present invention can be used not only in small and medium-sized industrial heating systems, but also in domestic and commercial heating and domestic hot water supply systems.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or modify some of the technical features. Equivalent replacements are made; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A porous ceramic combustion head for a low-nitrogen burner is characterized in that,

comprises a combustion head shell (1) and an inner air cylinder (2);

a fire hole plate is arranged at an opening at the top of the combustion head shell (1), the fire hole plate comprises at least two porous medium ceramic plates (3), and an internal protection plate (4) is arranged on the inner side of each porous medium ceramic plate (3);

the inner air duct (2) is inserted into the combustion head shell (1), and a plurality of ventilation openings (17) are formed in the surface of the inner air duct (2).

2. The porous ceramic burner head for a low-nitrogen burner according to claim 1,

the combustion head shell (1) is mainly formed by combining a front end plate (13), an upper plate (14), a lower plate (15) and a rear end plate (16);

the inner air duct (2) is inserted into the combustion head shell (1) from a through hole formed in the front end plate (13) and is in sealed connection with the front end plate (13);

the upper plate (14) is provided with at least two openings, the internal protection plate (4) is arranged at the openings from the inner side of the upper plate (14), and the porous medium ceramic plate (3) is arranged at the openings from the outer side of the upper plate (14);

one or more sewage draining holes are arranged on the rear end plate (16).

3. The porous ceramic burner head for a low-nitrogen burner according to claim 2,

the upper plate (14) comprises two top surfaces which form an included angle, one or more openings are formed in each top surface, one or more porous medium ceramic plates (3) are arranged on the outer side of each opening, and one or more internal protection plates (4) are arranged on the inner side of each opening.

4. The porous ceramic burner head for a low-nitrogen burner according to claim 3,

the edge of the porous medium ceramic plate (3) is provided with a fire guiding sheet (8), and the fire guiding sheet (8) is provided with round heat dissipation holes or strip-shaped heat dissipation holes.

5. The porous ceramic burner head for a low-nitrogen burner according to claim 4,

the fire guiding sheet (8) comprises a first fire guiding sheet (81) and a second fire guiding sheet (82) which are respectively positioned at the tops of the two top surfaces.

6. The porous ceramic burner head for a low-nitrogen burner according to claim 2,

the porous medium ceramic plate (3) is fixed on the upper plate (14) through a plurality of press plates, and the joint of the porous medium ceramic plate (3) and the upper plate (14) is sealed by high-temperature-resistant glue.

7. The porous ceramic burner head for a low-nitrogen burner according to claim 1,

round holes and/or strip-shaped holes are densely arranged on the internal protection plate (4).

8. The porous ceramic burner head for a low-nitrogen burner according to claim 1,

interior dryer (2) include play dryer (10) and connecting cylinder (12) of rear end of front end, play dryer (10) are located combustion head casing (1) is inside, connecting cylinder (12) are located combustion head casing (1) is outside, the tip of connecting cylinder (12) is provided with mounting flange (11), a plurality of vents (17) are densely arranged and are set up the surface of play dryer (10).

9. The porous ceramic burner head for a low-nitrogen burner according to claim 8,

from the front end to the rear end of interior dryer (2), the aperture of a plurality of vent (17) increases gradually.

10. The porous ceramic burner head for a low-nitrogen burner according to claim 8,

the total area of the openings of the plurality of ventilation openings (17) is equivalent to the inlet area of the mounting flange (11).

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