KR100965277B1 - Lean-rich combustion burner having characteristics of reducing pollutional material and stabilizing flame - Google Patents

Abstract

An object of the present invention is to provide a burner having a salt pore structure that can implement a two-stage combustion and excessive-lean burn to reduce the amount of NOx generated, and to implement a higher flame resistance than a flat flame.

The present invention for realizing this, a space in which a concentrated mixer flows is formed therein, and a plurality of first salt balls having a plurality of salt holes formed at predetermined intervals so that the concentrated mixer is ejected on a horizontal upper surface are installed in parallel at regular intervals. ; A plurality of second salt flakes each having a plurality of salt holes formed at predetermined intervals so that the lean mixer is ejected are formed between the first salt flakes on the left and right upper surfaces in which a space in which the lean mixer flows is formed and is upwardly bent; A plurality of first fuel nozzles are respectively installed at an inlet side of the plurality of first salt balls into which the concentrated mixer is introduced; At the inlet side of the plurality of second salt balls into which the lean mixer is introduced, a plurality of second fuel nozzles having a diameter smaller than that of the first fuel nozzle are provided.

Two-stage combustion, over-lean burn, NOx, flame, flame, turndown ratio, flame transition

Description

Lean-rich combustion burner having characteristics of reducing pollutional material and stabilizing flame}

The present invention relates to a super-lean burner having a pollution reduction and flame retardant characteristics, and simultaneously implements a multi-stage combustion method and a super-lean burn method to reduce the generation of NOx and to apply a salt ball structure with flame retardant properties. The present invention relates to an over-lean burn burner having improved flame safety.

In general, in the combustion method of gas fuel, premixed combustion in which gas fuel and combustion air are mixed in advance and then supplied to the combustion chamber, diffused combustion for separately supplying fuel and air, and premixed combustion and diffused combustion are mixed. There is partial premixed combustion.

The partial premixed combustion refers to the combustion produced by the Bunsen burner. The Bunsen burner pre-mixes the primary air and the fuel, which is a part of the supplied air, and supplies the secondary air to the flame-generating part. To induce. Conventional combustion gas appliances such as domestic gas boilers mainly employ Bunsen burners because of their advantages such as low flame stability and low risk of backfire.

However, the Bunsen burner has a long burn flame and high flame temperature, and the amount of air required for combustion requires a lot of excess air compared to the theoretical amount of air, resulting in high heat loss and high emissions of NOx and CO. It had limitations in maximizing the efficiency of equipment and reducing pollutants.

In general, NOx emitted from the combustor has an equivalent ratio as shown in the graph of FIG. 1. Equivalence ratio (Φ) represents the theoretical air-fuel ratio (AF _stoich ) with respect to the actual air-fuel ratio (AF _act ). Φ = 1 means that the theoretical air-fuel ratio is the same as the actual air-fuel ratio, Φ> 1 condition represents a rich burn, and Φ <1 condition represents a lean burn state, respectively.

Referring to FIG. 1, it can be seen that the equivalent ratio of NOx is most generated near 1, and the amount of NOx is reduced in the region of excessive combustion (Φ> 1) or lean combustion (Φ <1). The curve of equivalence ratio and flame temperature also shows the same characteristics as in FIG. 1.

Combustion methods that reduce the generation of NOx by using the relationship between the equivalent ratio and the flame temperature include two-stage combustion and rich-lean combustion.

Two-stage combustion is a method of lowering the maximum flame temperature by splitting and combusting fuel or air, and in general, splitting and supplying air, and fuel and a small amount of air are mixed in the primary combustion zone to make the fuel rich. Combustion occurs, while unburned is completely burned by the secondary air. This two-stage combustion is a combustion method that reduces the NOx by lowering the local temperature of the flame by lengthening the flame length (increasing the surface area of the flame → increasing the heat dissipation of the flame).

Superrich-lean combustion avoids the condition that the excess air ratio of fuel and air with the highest flame temperature is 1 in premixed combustion, and simultaneously forms the fuel rich with low excess air ratio and the fuel rich with high excess air ratio. By lowering the flame temperature, the amount of NOx is lowered, and the unstable phenomena such as the flying of the flame, which may occur in lean burning, are maintained by the flames caused by overcombustion. do.

On the other hand, compared to the conventional flame-type flame flames are improved flame flame structure that can reduce the lifting and resulting flame instability of the flame is disclosed in Korean Patent Registration No. 10-778716.

In addition, the gas boiler has a turn-down ratio (TDR) set according to the heating load required by the boiler. The turndown ratio (TDR) refers to the ratio of maximum gas consumption to minimum gas consumption in a gas combustion device in which the amount of gas is variably controlled. For example, if the maximum gas consumption is 30,000kcal / h and the minimum gas consumption is 6,000kcal / h, the turndown ratio (TDR) is 5: 1. The turndown ratio (TDR) is limited by how low the minimum gas consumption can be adjusted to maintain a stable flame.

In order to improve the turndown ratio, a method of increasing the turndown ratio (TDR) of the gas burner has been proposed by dividing the combustion zone of the burner into a plurality of zones and opening and closing the passage of gas injected into each combustion zone of the burner.

However, when the combustion zone is divided into three stage regions as shown in FIG. 2 to implement a multi-stage combustion structure, the first stage combustion region 10, the second stage combustion region 20, and the three stage combustion region 30 are adjacent to each other. It is arranged from left to right, so that the flame transition is unstable when the flame is transferred from the first stage combustion (FIG. 2A state) to the second stage combustion (FIG. 2B state) and the second stage combustion to the third stage combustion (FIG. 2C state). There was this.

The present invention is to solve all the problems of the conventional burner structure described above, while implementing a two-stage combustion and super-lean burn to reduce the amount of NOx generation, salt tools that can implement a higher flame resistance than a flat flame The purpose is to provide a burner with a jaw.

Another object of the present invention is to provide a burner that can improve the stability of flame transition by allowing the transition of flame from the center to the left and right sides when implementing a multi-stage combustion structure for improving the turndown ratio.

In order to achieve the above object, the present invention provides a space in which a concentrated mixer flows therein, and a plurality of first salt balls having a plurality of salt holes formed at predetermined intervals so that the concentrated mixer is ejected on a horizontal upper surface in parallel at regular intervals. Installed; A plurality of second salt flakes each having a plurality of salt holes formed at predetermined intervals so that the lean mixer is ejected are formed between the first salt flakes on the left and right upper surfaces in which a space in which the lean mixer flows is formed and is upwardly bent; A plurality of first fuel nozzles are respectively installed at an inlet side of the plurality of first salt balls into which the concentrated mixer is introduced; At the inlet side of the plurality of second salt balls into which the lean mixer is introduced, a plurality of second fuel nozzles having a diameter smaller than that of the first fuel nozzle are provided.

In addition, an air passage space may be formed between the first side and the opposite side of the second salt piece to pass a portion of the air introduced through the blower.

In addition, the one or more first salt flakes positioned in the center of the plurality of first salt flakes and the one or more second salt flakes adjacent to form a first stage combustion; At least one pair of salt flakes composed of the first salt flakes and the second salt flakes are installed in parallel on each of the left and right sides of the first stage combustion section to form a two stage combustion section, or the first salt flakes and the second salt flakes on the left and right sides of the two stage combustion section. One or more pairs of salt ball pieces each formed in parallel to further form a three-stage combustion unit; The flame formed in the first stage combustion unit may be configured to be transferred to a two-stage combustion unit or a three-stage combustion unit on both the left and right sides as the load increases, thereby multistage combustion.

In addition, the plurality of first fuel nozzles and the second fuel nozzles are respectively coupled to the lower side and the upper side of one side of the manifold for distributing fuel; On the other side of the manifold, the two-stage fuel is formed in a groove shape along the left and right circumference of the first stage fuel supply groove and the first stage fuel supply groove formed in the center portion to supply fuel to the first stage combustion unit. A two-stage fuel supply groove is formed to supply fuel to the unit, or the three-stage fuel unit is formed in a groove shape along the left and right circumferences of the two-stage fuel supply groove together with the first and second fuel supply grooves. It may be composed of a three-stage fuel supply groove is formed so that the fuel is supplied to.

In addition, the plurality of fuel supply grooves may be configured such that the fuel supply path is connected or blocked by the opening and closing operation of the solenoid valve.

According to the present invention, it is possible to reduce the amount of pollutants generated and to implement improved flame retardant properties, and the flame transition is stable.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a perspective view showing a burner according to an embodiment of the present invention, Figure 4 is an exploded perspective view of the burner shown in Figure 3, Figure 5 is a cross-sectional view AA of Figure 3, Figure 6 is a schematic cross-sectional view BB of Figure 3, FIG. 7 is a front view and a side view showing the first and second salt balls shown in FIG. 3, respectively.

The burner of the present invention includes a burner body part 100 having a space in which a mixture of air and fuel flows and having a flame formed thereon, and a manifold installed at one side of the burner body part 100 to introduce fuel. The fold 200, a blower 300 installed at the lower side of the burner body part 100, and air is introduced therein, and a cover 400 covering the side surface of the manifold 200.

The burner body part 100 is provided with a plurality of first salt holes 110 and second salt holes 120 each having a salt hole for forming a flame, the first salt hole piece 110 and the second salt A plate-shaped diaphragm 130 is provided at the lower end of the specimen 120.

As shown in FIG. 7A, the first salt ball piece 110 includes a mixing passage having a space formed therein so that a mixture of fuel and air introduced through the inlet 111 through which the fuel and the air flows in and through the inlet 111 is passed through. (112), the upper surface 113 is formed with a salt hole 114 is ejected through the mixer passage 112 through the mixer.

The mixer passage 112 is formed in a zigzag shape to allow sufficient mixing of air and fuel. The upper surface 113 is formed in a horizontal shape so that the salt hole 114 is directed vertically.

As shown in FIG. 7B, the second salt ball piece 120 has a space in which a space is formed such that a mixture of fuel and air introduced through the inlet 121 through which the fuel and air are introduced passes through the inlet 121. And a top surface 123 having a salt hole 124 through which the mixer passed through the mixer passage 122 is ejected. The upper surface 123 is bent upward and the salt hole 124 is formed so that the mixer is ejected to the left and right symmetrical surface.

The first salt flakes 110 and the second salt flakes 120 are alternately arranged in parallel, as shown in FIG.

The rich salt mixer is supplied to the inside of the first salt piece 110 so that the concentrated combustion is performed on the upper surface 113.

A lean mixer is supplied inside the second salt ball piece 120 to perform lean combustion on the upper surface 123.

The first fuel nozzles 211 and the second fuel nozzles 212 are disposed on the inlets 111 and 121 of the first salt ball piece 110 and the second salt ball piece 120 so as to be spaced apart from each other by a predetermined distance.

The first fuel nozzle 211 and the second fuel nozzle 212 are fixed to one side of the manifold 200 in which a fuel flow path is formed.

The first fuel nozzle 211 is installed at a predetermined interval in the horizontal direction by the same number as the first salt hole piece 110, the second fuel nozzle 212 is higher than the first fuel nozzle 211 Located in the spaced apart in the horizontal direction by the same number as the second salt ball piece 120 is installed.

Accordingly, the concentrated fuel injected through the first fuel nozzle 211 flows into the inlet 111 of the first salt hole piece 110, and the lean fuel injected through the second fuel nozzle 212 is the second fuel nozzle 211. The inlet 111 of the first salt ball piece 110 and the inlet 121 of the second salt ball piece 120 are formed differently from each other so as to flow into the inlet 121 of the two salt pieces 120.

The fuel supplied through the first fuel nozzle 211 has a nozzle diameter set such that the fuel-air mixer is rich, and the fuel supplied through the second fuel nozzle 212 is fuel-air. The nozzle diameter is set so that the mixer of is in a lean state.

The inlet path of the fuel-air mixer of the present invention having the above configuration will be described.

First, fuel is introduced through a fuel inlet (not shown) provided at one side of the manifold 200. The fuel introduced through the fuel inlet is branched and supplied to the first fuel nozzle 211 and the second fuel nozzle 212, and then the inlet 111 and the second salt cavity (of the first salt hole piece 110). It is ejected to the inlet 121 of 120. In this case, the amount of fuel passing through the nozzles 211 and 212 can be set by the diameter of the nozzle.

The air supplied upward through the blower 300 flows in a lateral direction by the diaphragm 130 and flows laterally through the air flow space 140 formed in the lower portion of the burner body 100.

The air passing through the air flow space 140 is supplied to the inlet 111 of the first salt ball piece 110 and the inlet 121 of the second salt ball piece 120 to the first and second fuel nozzles 211 and 212. Is mixed with the ejected fuel.

The fuel-air mixer in which mixing starts at the inlets 111 and 121 is sufficiently mixed with fuel and air via the mixing passages 112 and 122.

The mixer that passes through the mixing cylinder path 112 of the first salt ball piece 110 is ejected through the salt hole 114 to form a super-concentrated salt, and the mixer that passes through the mixing cylinder path 122 of the second salt ball piece 120. Is ejected through the salt hole 124 to form a lean salt.

The upper surface 113 in which the salt holes 114 are formed in the first salt hole piece 110 has a horizontal shape, and the upper surface 123 in which the salt holes 124 are formed in the second salt hole piece 120 is bent upward to have different directions. It has a structure formed with two inclined surfaces facing. Therefore, the flame formed in the salt hole 114 of the first salt hole piece 110 is formed in the vertical direction, whereas the flame formed in the salt hole 124 of the second salt hole piece 120 is inclined with respect to the vertical direction. Thus, the flame structure is formed while colliding with the flame formed in the salt hole 114 of the first salt hole piece 110.

As a result, the flame retardancy of the flame is improved compared to the conventional flat flame, and the lifting of the flame and the instability thereof are reduced even when the air ratio of the flame or the load of the premixer is increased, and the flame length is reduced by the vertical length of the flame. In case of direct contact, it is possible to prevent the generation of incomplete combustion products such as carbon monoxide.

In addition, it is possible to burn all of the unburned components by improving the mixing of the unburned components of the rich flame through the collision of both lean flames, and in the case of the high load, the ejection speed increases to realize better mixing characteristics. .

In addition, the present invention divides and supplies fuel and air to the first salt flakes 110 and the second salt flakes 120 and puts the difference between the heights of the super-concentrated salt holes 114 and the lean flame salt holes 124 for two-stage combustion and overconcentration. -It is possible to reduce the amount of NOx generated by implementing lean burn at the same time.

On the other hand, as shown in Figure 6, the air passage space 150 to pass a portion of the air introduced through the blower 300 between the opposite side of the first salt ball piece 110 and the second salt ball piece 120. ) Is preferably formed.

Most of the air supplied from the blower 300 is blocked by the diaphragm 130 and flows in the lateral direction of the air flow space 140, and the remaining portion is passed through the air through the hole 130a formed in the diaphragm 130. It is supplied to the space 150.

The air flowing through the air passage space 150 may be prevented from being damaged by the red heat of the salt holes pieces 110 and 120. In addition, since the air is blown out through the air passage space 150 to form a diffusion combustion region, a stable combustion can be made in a wider load region by supplementing the characteristics of the narrow premixed burner. .

Hereinafter, with reference to FIGS. 8 to 10, a high turndown ratio (TDR) through three-stage combustion and a structure in which flame transition is stable will be described.

Figure 8a is a view showing a state in which the first stage combustion with a heating load is a low load, Figure 8b is a view showing a state in which the two-stage combustion with a heating load is a heavy load, Figure 8c is a three-stage combustion with a heating load is a high load 9 is a schematic view showing a side cross-section of the manifold portion shown in FIG. 4, and FIGS. 10A and 10B are perspective views showing the manifold of the present invention.

Referring to FIG. 8A, when the heating load is low and the first stage combustion occurs, rich flames are generated in the three first salt pieces 110 in the center, and the two second salt pieces therebetween. A lean flame is generated at 120 to form the first stage combustion part A part.

In this state, when the heating load increases, two stage combustion is performed as shown in FIG. 8B. That is, when the second stage combustion starts in the state where the flame is formed in the first stage combustion unit (part A), the mixer is ejected through the salt holes of the first and second salt ball pieces 110 and 120 located on the left and right sides of the first stage combustion unit (part A). Then, the flame of the first stage combustion section (Part A) is shifted from side to side to form a two stage combustion section (Part B).

In the past, the flame is unstable because the flame is transferred in one direction, but in the present invention, the flame is stably made because the flame is made in both the left and right directions. This is because the mixer is ejected through the two-stage combustion section (B) when the heating load is increased, so that the change in the ejection pressure is not large.

In the state of FIG. 8B, when the heating load increases, three stage combustion is performed as shown in FIG. 8C. In this case, the flame is transferred to the three stage combustion section (C section) on the left and right sides by the flame formed in the two stage combustion section (B section).

Thus, the structure of the manifold for implementing a burner in which the flame is divided into two sides in the center and transferred to the center will be described with reference to FIGS. 9 and 10.

The first and second fuel nozzles 211 and 212 are installed at one side of the manifold 200 to face the inlets 111 and 121 of the salt holes 110 and 120, and the first and second stage combustion units are respectively provided at the other side. First, second and third stage fuel supply grooves 201, 202 and 203 for supplying fuel are formed.

The first stage fuel supply groove 201 is connected so that fuel is always supplied to all the load areas during the operation of the burner by opening and closing the main fuel supply valve (not shown).

Three through holes 201a are formed on the inner wall of the first stage fuel supply groove 201 and two through holes 201b are disposed on the lower side of the first fuel supply groove 201 to the first fuel nozzle 211 and the second fuel nozzle 212. Each is connected.

The fuel introduced into the first stage fuel supply groove 201 by the opening of the main fuel supply valve is mixed with air while passing through the through holes 201a and 201b, the fuel nozzles 211 and 212 and the inlets 111 and 121. It is supplied to the short combustion section.

One side of the first stage fuel supply groove 201 and one side of the second stage fuel supply groove 202 are connected to each other by a first connection hole 204, and the first connection hole 204 is connected to a first solenoid valve ( 221 is opened and closed.

The two stage fuel supply groove 202 is formed in a groove shape along the left and right circumference of the first stage fuel supply groove 201.

On the left and right sides of the inner wall of the two-stage fuel supply groove 202, one through-hole 202a is formed at the lower side and one through-hole 202b at the upper side, so that the first fuel nozzle 211 and the second fuel nozzle ( 212), respectively.

The fuel introduced into the second stage fuel supply groove 202 is mixed with air while passing through the through holes 202a and 202b, the fuel nozzles 211 and 212 and the inlets 111 and 121, and then supplied to the second stage combustion unit.

The other side of the first stage fuel supply groove 201 and the third stage fuel supply groove 203 are connected to each other by a second connection hole 205, and the second connection hole 205 is a second solenoid valve 222. It is opened and closed by.

The three-stage fuel supply groove 203 is formed in a groove shape along the left and right circumference of the two-stage fuel supply groove 202.

On the left and right sides of the inner wall of the three-stage fuel supply groove 203, one through-hole 203a is formed at the lower side and two through-holes 203b at the upper side, so that the first fuel nozzle 211 and the second fuel nozzle ( 212), respectively.

The fuel introduced into the three-stage fuel supply groove 203 is mixed with air while passing through the through holes 203a and 203b, the fuel nozzles 211 and 212 and the inlets 111 and 121, and then is supplied to the three-stage combustion unit.

The first solenoid valve 221 is closed at the first stage combustion and blocks the fuel introduced into the first stage fuel supply groove 201 from being supplied to the second stage fuel supply groove 202, and is opened at the second stage combustion. The fuel introduced into the short fuel supply groove 201 is supplied to the second fuel supply groove 202.

The second solenoid valve 222 is closed at the first stage and the second stage combustion to block the fuel introduced into the first stage fuel supply groove 201 from being supplied to the third stage fuel supply groove 203, and at the time of the three stage combustion The fuel that is opened and introduced into the first fuel supply groove 201 is supplied to the third fuel supply groove 203.

According to this structure, it realizes a high turndown ratio of 10: 1 through three stage combustion and at the same time, the flame is transferred from the center to the left and right sides even when the heating load is increased from the first stage to the second stage and the second stage to the third stage. Transition is possible.

In the above described the present invention based on the preferred embodiment, the present invention is not limited to the above embodiment, various modifications by those skilled in the art within the scope of the technical idea of the present invention This is possible.

1 is a graph showing a relationship between NOx and an equivalent ratio;

2 is a schematic view showing a conventional multi-stage combustion state,

3 is a perspective view showing a burner according to an embodiment of the present invention,

Figure 4 is an exploded perspective view of the burner shown in Figure 3,

5 is a cross-sectional view A-A of FIG.

6 is a cross-sectional schematic view taken along line B-B of FIG.

7 is a front view and a side view showing the salt flakes shown in FIG.

8A is a view showing a state in which the first stage combustion is performed with the heating load at a low load;

8b is a view showing a state in which the heating load is a two-stage combustion with a heavy load,

8c is a view showing a state in which the heating load is a three-stage combustion with a high load,

9 is a schematic view showing a side cross-section of the manifold portion shown in FIG.

10a, b are perspective views showing a manifold of the present invention.

Explanation of symbols on the main parts of the drawings

100: burner body 110: the first salt flight

120: second salt flight 111,121: inlet

112,122: Mixing passage 113,123: Upper surface

114,124: Flame attack 130: Plate

140: air flow space 150: air passage space

200: Manifold 201: 1st stage fuel supply groove

202: 2-stage fuel supply groove 203: 3-stage fuel supply groove

201a, b, 202a, b, 203a, b: Through-hole 211: First fuel nozzle

212: second fuel nozzle 221: the first solenoid valve

222: second solenoid valve 300: blower

400: cover

Claims (5)

A space in which a concentrated mixer flows is formed therein, and a plurality of first salt balls having a plurality of salt holes formed at predetermined intervals are installed in parallel at a predetermined interval on a horizontal upper surface so that the concentrated mixer is ejected; A plurality of second salt flakes each having a plurality of salt holes formed at predetermined intervals so that the lean mixer is ejected are formed between the first salt flakes on the left and right upper surfaces in which a space in which the lean mixer flows is formed and is upwardly bent; A plurality of first fuel nozzles are respectively installed at an inlet side of the plurality of first salt balls into which the concentrated mixer is introduced; An inlet-lean combustion burner having pollutant reduction and flame retardant characteristics, each of which is provided with a plurality of second fuel nozzles having a diameter smaller than that of the first fuel nozzle, at an inlet side of the plurality of second salt holes into which the lean mixer is introduced. The method of claim 1, An air-tight combustion burner having air pollution reduction and flame retardant characteristics, characterized in that an air passage space is formed between the opposite sides of the first salt flakes and the second salt flakes to allow a portion of the air introduced through the blower to pass therethrough. The method according to claim 1 or 2, One or more first salt flakes positioned in the center of the plurality of first salt flakes and one or more second salt flakes adjacent thereto form a first stage combustion unit; At least one pair of salt flakes composed of the first salt flakes and the second salt flakes are installed in parallel on each of the left and right sides of the first stage combustion section to form a two stage combustion section, or the first salt flakes and the second salt flakes on the left and right sides of the two stage combustion section. One or more pairs of salt ball pieces each formed in parallel to further form a three-stage combustion unit; The flame formed in the first stage combustion unit is transferred to the two stage combustion unit or the three stage combustion unit on both the left and right sides as the load increases, and thus the multi-stage combustion is performed. burner. The method of claim 3, The plurality of first fuel nozzles and the second fuel nozzles are respectively coupled to a lower side and an upper side of one side of a manifold for distributing fuel; On the other side of the manifold, the two-stage fuel is formed in a groove shape along the left and right circumference of the first stage fuel supply groove and the first stage fuel supply groove formed in the center portion to supply fuel to the first stage combustion unit. A two-stage fuel supply groove is formed to supply fuel to the unit, or the three-stage fuel unit is formed in a groove shape along the left and right circumferences of the two-stage fuel supply groove together with the first and second fuel supply grooves. Three-stage fuel supply groove is formed so that the fuel is supplied to the super-lean burn burner having a pollution reduction and flame-retardant characteristics characterized in that. The method of claim 4, wherein The plurality of fuel supply grooves are over-lean burn burner having a pollutant reduction and flame resistance characterized in that the fuel supply path is connected or blocked by the opening and closing operation of the solenoid valve.

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