KR101269145B1 - Regenerative burner injecting two-staged fuel and air - Google Patents

Abstract

The regenerative burner according to the embodiment of the present invention includes a burner body having a gas access passage in which combustion air is introduced or exhaust gas is discharged, a primary air injection hole communicating with the gas access passage and formed at one end of the burner body, It is in communication with the primary air injection port and is formed at one end of the burner body, the communication chamber and the gas access passage is formed at one end, the secondary air injection port formed outside the primary air injection port, the burner body And a second fuel nozzle embedded in the burner body while penetrating through the first fuel nozzle and the burner body, the second fuel nozzle being formed outside of the primary air injection port based on a cross section of one end thereof.

Combustion apparatus, burners, heat storage, fuel nozzles, nitrogen oxides

Description

Regenerative burner that injects fuel and air in two stages {REGENERATIVE BURNER INJECTING TWO-STAGED FUEL AND AIR}

The present invention relates to a regenerative burner which burns fuel and air among the components of a regenerative combustion device to provide a flame to the combustion device, and more particularly, a regenerative burner that can minimize damage to a fuel nozzle even when combustion proceeds for a long time. It is about.

In general, in a facility using a burner such as a heating furnace or a boiler, it is important to suppress the amount of nitrogen oxides to prevent environmental pollution as well as thermal efficiency. That is, when gaseous fuel is used, nitrogen and oxygen in the air react at a high temperature to generate so-called thermal NOx. These nitrogen oxides are pointed out as a major factor causing environmental pollution, various techniques have been developed to suppress their production.

Thus, an air two-stage combustion burner that suppresses the production of nitrogen oxides has been proposed, and is known in Korean Patent Registration No. 056814. Air 2-stage combustion burners supply air for combustion in two stages inside the burner. In general, a two-stage combustion burner supplies 20 to 70% of the amount of air required for the first stage to reduce nitrogen oxide production due to lack of oxygen and to suppress nitrogen oxide production due to a decrease in combustion temperature. It is configured to completely burn the unburned fuel by spraying in the second stage.

In addition, a regenerative burner that recovers the waste heat contained in the combustion gas and raises the temperature of the combustion air is used in heating furnaces and other industrial furnaces, and is known from Korean Utility Model Registration No. 0276859. That is, two or more regenerative burners are installed in a heating furnace or other industrial furnace, and when one of the plurality of regenerative burners performs combustion operation, the other regenerative burner is configured to discharge the exhaust gas. The heat storage burner is provided with a heat storage device in the exhaust gas discharge passage, and is configured to preheat the combustion air during the combustion operation.

As described above, a regenerative burner configured to preheat air for combustion while supplying air in two stages in order to suppress nitrogen oxide generation is widely used in industrial fields.

The present invention aims to provide a regenerative burner having an improved structure so that fuel nozzles are not damaged even when exposed to radiant heat of a long time furnace while suppressing generation of nitrogen oxides by injecting fuel and air in two stages.

The regenerative burner according to the embodiment of the present invention includes a burner body having a gas access passage in which combustion air is introduced or exhaust gas is discharged, a primary air injection hole communicating with the gas access passage and formed at one end of the burner body, It is in communication with the primary air injection port and is formed at one end of the burner body, the communication chamber and the gas access passage is formed at one end, the secondary air injection port formed outside the primary air injection port, the burner body And a second fuel nozzle embedded in the burner body while penetrating through the first fuel nozzle and the burner body, the second fuel nozzle being formed outside of the primary air injection port based on a cross section of one end thereof.

The secondary air injection port and the second fuel nozzle may be arranged on the same circumference in the cross section of one end. In this case, a plurality of secondary air injection holes and second fuel nozzles may be disposed, and the secondary air injection holes and the second fuel nozzles may be alternately disposed.

The diameter of the gas access passage may be larger than the diameter of the first air injection port based on the cross section.

The first fuel supply pipe and the second fuel supply pipe may be respectively inserted into the first fuel nozzle and the second fuel nozzle which protrude to the outside of the burner body.

Air may be provided to the combustion chamber through the first air injection port, and fuel may be provided to the combustion chamber through the first fuel nozzle.

Air may be provided to the combustion furnace of the combustion apparatus through the second air injection port, and fuel may be provided to the combustion furnace through the second fuel nozzle.

The combustion chamber, the secondary air injection port and the second fuel nozzle may be in communication with the combustion furnace of the combustion device to provide flame to the combustion furnace.

The incompletely combusted portion of the flame provided to the combustion furnace in the combustion chamber may be completely combusted by the air injected through the secondary air injection port.

The regenerative burner according to the embodiment of the present invention not only suppresses the generation of nitrogen oxide more reliably by the configuration of injecting fuel and air in two stages, but also improves the combustion energy efficiency by the regenerative configuration of preheating combustion air. Can be.

In addition, since the fuel nozzles are not directly contacted or exposed to radiant heat by the flame in the combustion furnace, the fuel nozzles are not easily damaged even in a long time use, thereby improving life.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is a cross-sectional view schematically showing a regenerative combustion device.

Referring to FIG. 1, a regenerative combustion device is a device to which a regenerative burner 200 according to an embodiment of the present invention is applied.

The regenerative combustion device 100 is generally equipped with a pair of regenerative burners 200 and 201 in one combustion furnace 110. For example, when the first heat storage burner 200 performs a combustion operation, the second heat storage burner 201 discharges the exhaust gas generated in the combustion furnace 110.

The regenerative combustion device 100 is generally supplied with fuel through a single pipe, and is divided into a first regenerative burner 200 and a second regenerative burner 201 at one point. Although the first regenerative burner 200 burns and the second regenerative burner 201 exhausts the exhaust gas through FIG. 1, the first regenerative burner 200 and the second regenerative burner 201 are fixed. With a cycle, the combustion operation and the exhaust emission operation can be performed alternately.

Referring to the operation of the regenerative combustion device 100, the first fuel switching valve 130 installed in the first fuel supply pipe 120 is maintained in the open state, the first fuel supply pipe 121 is installed in the second fuel supply pipe 121 2 The fuel switching valve 131 is kept closed. Then, fuel is supplied to the first heat storage burner 200 through the first fuel supply pipe 120, and combustion air is supplied to the first heat storage burner 200 through the first air pipe 160. In this operating state, the second heat storage burner 201 serves to discharge the exhaust gas and discharges the exhaust gas to the second air pipe 161. At this time, the first air pipe 160 and the second air pipe 161 are connected to the gas selector 150, the gas switch 150 is the combustion air in accordance with the operation of the switching valve mode installed therein Or change the direction of the exhaust gas.

A first heat storage 140 and a second heat storage 141 are connected to the first heat storage burner 200 and the second heat storage burner 201, respectively. Combustion air supplied to the first heat storage burner 200 is preheated while passing through the first heat storage 140, and exhaust gas discharged through the second heat storage burner 201 exchanges sensible heat and heat exchange therein. Through the second heat accumulator 141 is stored.

On the other hand, the first regenerative burner 200 and the second regenerative burner 201 may exchange their functions. That is, the first heat accumulator 140 accumulates the sensible heat of the exhaust gas, and the second heat accumulator 141 preheats the combustion air by using the regenerated sensible heat.

Hereinafter, the regenerative burner 200 according to the embodiment of the present invention used in the regenerative combustion device 100 will be described in more detail.

FIG. 2 is a cross-sectional view schematically illustrating a regenerative burner 200 according to an exemplary embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2.

2 and 3, the regenerative burner 200 according to the embodiment of the present invention includes a burner body 210 and a combustion chamber 230 in which a gas access passage 220 is formed.

The burner body 210 is connected to communicate with the heat storage 140 shown in FIG. 1, and combustion air is introduced or exhaust gas is discharged through the gas access passage 220. At this time, the regenerative burner 200 is provided with the combustion air preheated in the regenerator 140 through the gas access passage 220 therein, thereby improving the combustion efficiency of the regenerative burner 200 during the combustion process. have.

The combustion chamber 230 is formed in communication with the gas access passage 220 in the burner body 210. A primary air injection port 240 is formed between the gas access passage 220 and the combustion chamber 230, and both ends of the primary air injection port 240 communicate with the gas access passage 220 and the combustion chamber 230, respectively. . By this structure, the combustion air flowing into the one end of the primary air injection port 240 from the gas access passage 220 is injected into the combustion chamber 230 at the other end of the primary air injection port 240. At this time, since the primary air injection port 240 has a smaller volume than the gas access passage 220, combustion air introduced into a relatively narrow space may be smoothly supplied to the combustion chamber 230 by pressure. .

In addition, the first fuel nozzle 250 is formed such that one end thereof communicates with the combustion chamber 230 while passing through the burner body 210. The first fuel supply pipe 251 is inserted into an end of the first fuel nozzle 250 protruding outward of the burner body 210, and the fuel provided from the first fuel supply pipe 251 is first fuel nozzle 250. It is injected into the combustion chamber 230 through. Here, the first fuel nozzle 250 is installed to penetrate the inside from the outside of the burner body 210, since the direction crosses the x-axis of FIG. 2, the flame generated from the combustion chamber 230 to the combustion furnace 110 Not on the same straight line as. Accordingly, the first fuel nozzle 250 may not be exposed to the radiant heat of the flame.

According to the above configuration, the combustion air injected from the primary air injection port 240 and the fuel injected from the first fuel nozzle 250 are mixed in the combustion chamber 230 and combusted first.

On the other hand, the heat storage burner 200 of the present embodiment includes a secondary air injection port 260 and the second fuel nozzle 270.

The secondary air injection port 260 is formed in communication with the gas access passage 220 similarly to the primary air injection port 240. Specifically, one end of the secondary air injection port 260 is in communication with the gas access passage 220, the other end is in communication with the combustion furnace. As shown in FIG. 3, the other end of the secondary air injection hole 260 is formed outside the combustion chamber 230 located at the center of the cross section, and the plurality of secondary air injection holes 260 open the combustion chamber 230. It can be formed along the circumference.

Secondary air injection port 260 also has a smaller volume than the gas access passage 220 can efficiently inject the combustion air into the combustion furnace. Combustion air flowing into the gas access passage 220 may be divided into a primary air injection port 240 and a secondary air injection port 260.

On the other hand, not only the combustion air is introduced through the primary air injection port 240 and the secondary air injection port 260, but also the exhaust gas discharged from the heat storage burner 200 is the primary air injection port 240 and the secondary air. It is discharged to the outside of the heat storage burner 200 through the injection hole 260.

The second fuel nozzle 270 is embedded in the burner body 210. Like the first fuel nozzle 250, the second fuel supply pipe 271 is inserted into the second fuel nozzle 270, and the other end thereof is in communication with the combustion furnace 110. Here, the second fuel supply pipe 271 is inserted into the second fuel nozzle 270 to penetrate the burner body 210 from the outside of the burner body 210, and the second fuel nozzle 270 is inserted into the combustion chamber 230. It is formed to be buried in the burner body 210 along the parallel direction. A plurality of second fuel nozzles 270 may be formed, and may be arranged in a circumference along the outer side of the combustion chamber 230 as shown in FIG. 3.

That is, the second fuel nozzle 270 may be formed on the same circumference as the secondary air injection hole 260. In this case, the second fuel nozzle 270 and the secondary air injection holes 260 may be alternately arranged. However, the present invention is not limited thereto, and the second fuel nozzle 270 and the secondary air injection hole 260 may be arranged along the outer side of the combustion chamber 230, but may be disposed on another circumference.

Since the second fuel nozzle 270 is buried in the burner body 210, radiant heat is hardly transferred from the flame in the combustion furnace 110.

As described above, the first fuel nozzle 250 and the second fuel nozzle 270 of the regenerative burner 200 according to the embodiment of the present invention have a minimum portion, that is, inside the combustion chamber 230 or the combustion furnace 110. , Only its end is exposed. As a result, the first fuel nozzle 250 and the second fuel nozzle 270 do not directly contact the radiant heat having the straightness, and do not contact the hot gas generated in the combustion chamber 230 or the combustion furnace 110. Therefore, even if the regenerative burner 200 is operated for a long time, the nozzles 250 and 270 may be prevented from being damaged as much as possible, and the nozzles 250 and 270 may be effectively prevented from being oxidized by the hot gas. have.

In addition, since the first fuel nozzle 250 and the second fuel nozzle 270 are not exposed to the air injection holes 240 and 260 or the gas access passage, the first fuel nozzle (1) when the regenerative burner 200 is operated. There is no need for a separate cooler to cool the 250 and the second fuel nozzle 270.

Regenerative burner 200 according to an embodiment of the present invention is primarily in the central region of the regenerative burner 200 through the combustion air and fuel injected from the primary air injection port 240 and the first fuel nozzle 250. Combustion takes place. At this time, the fuel incompletely burned in the primary combustion process is completely mixed with the combustion air injected through the secondary air injection port 260. In addition, the air injected through the secondary air injection port 260 can smoothly recycle the air in the combustion furnace 110, thereby reducing the oxygen concentration in the combustion air to suppress the generation of nitrogen oxides. On the other hand, since combustion is also performed through the combustion air and fuel injected from the secondary air injection hole 260 and the second fuel nozzle 270, not only the combustion efficiency of the regenerative burner 200 is increased, but also the secondary air injection hole 260. ) And the second fuel nozzle 270 are uniformly formed at the outer side of the combustion chamber 230 located in the central region, thereby providing a uniform flame peak in the combustion furnace 110.

The inventors of the present invention prepared the regenerative burner 200 in the above-described structure, and carried out a regenerative combustion test on the regenerative burner to measure the generation concentration of nitrogen oxide, and found the following results.

In the experimental example, the natural gas fuel was burned using the regenerative burner 200 according to the embodiment of the present invention. The combustion furnace 110 used in the experimental example has a square shape having a width, length, and length of 0.6 m, 0.6 m, and 3 m, respectively, and a regenerative burner 200 is installed at both ends thereof.

The injection speed of the combustion air and fuel of the regenerative burner 200 was maintained at 30m / s or more at room temperature, the specific regenerative combustion conditions are shown in Table 1 below. Here, the temperature of the combustion furnace 110 is measured by measuring the temperature of the middle portion in the longitudinal direction of the combustion furnace, the combustion capacity is the combustion capacity of the regenerative burner 200 used, the switching time is the regenerative burner respectively installed at both ends The time spent in the combustion process by selecting one of them alternately.

Combustion capacity
(kcal / h) First / second fuel ratio Furnace temperature
(℃) Switching time
(sec) NOx concentration
(ppm) Experimental Example 1 12 million 30: 70 1130 90 39 Experimental Example 2 170,000 50: 50 1150 90 30 Experimental Example 3 170,000 30: 70 1150 90 36 Experimental Example 4 170,000 0: 100 1160 90 28

Referring to Table 1, in Experimental Examples 1 to 4, as a result of performing regenerative combustion, the concentration of nitrogen oxides was 28 to 39 ppm, which showed a significantly lower concentration of nitrogen oxides compared to 70 ppm, which is a general average nitrogen oxide concentration. That is, it can be seen that the use of the regenerative burner according to the embodiment of the present invention enables low pollution combustion.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

1 is a view schematically showing a regenerative combustion device.

2 is a cross-sectional view schematically showing a regenerative burner according to an embodiment of the present invention.

3 is a sectional view taken along line III-III in Fig.

DESCRIPTION OF THE REFERENCE NUMERALS to main parts of the drawings

200; Regenerative burner 210; Burner body 220; Gas passage

230; Combustion chamber 240; Primary air nozzle 260; Secondary air nozzle

250; First fuel nozzle 270; Second fuel nozzle

Claims (10)

A burner body having a gas access passage through which combustion air is introduced or exhaust gas is discharged; A primary air injection port communicating with the gas access passage and formed at one end of the burner body; A combustion chamber in communication with the primary air injection port and formed at one end of the burner body; A secondary air injection hole communicating with the gas access passage and formed at one end thereof and formed outside the primary air injection hole based on a cross section of the one end; A first fuel nozzle installed to penetrate the burner body and expose an end portion of the burner to the inside of the combustion chamber; And A second fuel nozzle embedded in the burner body while penetrating through the burner body and formed outside the primary air injection hole based on a cross section of the one end portion; And the secondary air injection port and the second fuel nozzle are arranged on the same circumference in the cross section of the one end, and the secondary air injection port and the second fuel nozzle are alternately arranged. delete The method of claim 1, And a plurality of the secondary air injection holes and the second fuel nozzles. delete The method of claim 1, The regenerative burner having a diameter of the gas access passage based on the cross section larger than a diameter of the first air injection port. The method of claim 1, And a first fuel supply pipe and a second fuel supply pipe, respectively, inserted into the first fuel nozzle and the second fuel nozzle which protrude outside the burner body. The method of claim 1, The regenerative burner of which air is supplied to the combustion chamber through the first air injection port and fuel is supplied to the combustion chamber through the first fuel nozzle. The method of claim 1, The regenerative burner of which air is supplied to the combustion furnace of the combustion apparatus through the second air injection port, and fuel is supplied to the combustion furnace through the second fuel nozzle. The method of claim 1, The combustion chamber, the secondary air injection port and the second fuel nozzle communicate with a combustion furnace of a combustion device to provide flame to the combustion furnace. 10. The method of claim 9, Regenerative burner in which the incompletely burned portion of the flame provided to the combustion furnace in the combustion chamber is completely burned by the air injected through the secondary air injection port.

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