JP2002286206A - Heavy oil burner cooling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heavy oil burner cooling apparatus wherein remaining oil in a heavy oil burner is prevented from being carbonized. SOLUTION: A heavy oil burner cooling apparatus is adapted to include a distance piece 15 supported and fixed in a furnace 1 so as to be protruded with a predetermined length in the furnace 1, a heavy oil burner 14 where a burner section 14b inserted into the distance piece 15 freely to go front and backward is provided, protruded, and cooing air supply means for supplying cooling and sealing air into the distance piece 15. In the heavy oil burner cooling apparatus, upon the heavy oil burner being extinguished and upon boiler hot banking a burner chip 18 at a top end of the burner section 14b supports the heavy oil burner freely to go forward and backward from an opening in the tip end of the distance piece 15, and when it is withdrawn, supply of the cooling air is not interrupted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling apparatus for a heavy oil burner in a heavy oil boiler, and more particularly to a cooling apparatus for a heavy oil boiler which is installed in a boiler furnace to prevent carbonization of residual oil at the tip of the burner during boiler hot banking and to operate during a boiler operation. The present invention relates to a heavy oil burner cooling device that does not require cooling steam.

[0002]

2. Description of the Related Art In recent years, boilers for thermal power plants in Japan have been converting fuel from conventional heavy oil-fired boilers to pulverized coal-fired boilers in order to correct the dependence on coal.
Especially for special-purpose boilers, a large-capacity thermal power plant is built with pulverized coal. Therefore, especially in the case of heavy oil-fired power, the boiler load is not always operated at full load, and the boiler load is increased or decreased to 75%, 50%, or 25% load, or operation is stopped. For example, a so-called Daily Start Stop operation is being performed to shift to a thermal power plant that carries an intermediate load. After the fire is extinguished, the fuel oil burner evaporates the residual oil of the fuel in the fuel oil burner into the furnace or barges with air, but slightly adheres to the thin film as residual oil and remains in the fuel oil burner.
Therefore, in order to prevent the residual oil from carbonizing due to a rise in the temperature of the heavy oil burner being extinguished due to the radiant heat from the furnace, cooling steam is supplied to the heavy oil burner (fire extinguishing burner) that is not in operation to cool. It is carried out. However, the spraying of the cooling steam creates wet conditions for corrosion of the burner chips and cold corrosion in the boiler, and cooling steam is not preferred. In addition, since steam is wasted, the boiler efficiency is reduced.

[0003] On the other hand, during boiler hot banking, since the furnace temperature is 200 to 300 ° C, carbonization of residual oil is reduced to 15 ° C.
Long term in an atmosphere of 0 to 200 ° C or more (about 10 hours or more)
In the prior art, a blower dedicated to a heavy oil burner is provided, or a branch is provided by a flame detector, a cool air blower, or the like, and the inside of the heavy oil burner is cooled by the following method. Hereinafter, the prior art will be described with reference to FIGS. FIG. 2 is a diagram showing an example of an air system of a conventional heavy oil burner cooling device, FIG. 3 is a detailed view showing a part of a heavy oil burner portion in FIG. 2 in an enlarged manner, and FIG. 4 is cooling air and a burner during boiler hot banking. An air system diagram when the sealing air is taken out by a dedicated blower. Fig. 5 uses a burner dedicated blower only during boiler hot banking, and FD during boiler operation.
FIG. 6 is a diagram of a cooling steam system that is used for cooling when the heavy oil burner is stopped when the outlet air from the F-port is used.

[0004] As shown in FIG. 2, a predetermined number of heavy oil burners 14 are provided from a wind box 2 attached to the furnace 1 into the furnace 1. Cooling air is supplied to each heavy oil burner 14 from a burner dedicated blower 6. The burner-dedicated blower 6 has an air suction port as the atmosphere, and the inlet side includes a silencer 7, an inlet damper 8, and an inlet duct 9. The outlet side of the burner blower 6 is the outlet damper 1
0, a blower outlet 13 and an outlet duct 11.

[0005] Each heavy oil burner 14, as shown in FIG.
The fuel oil burner 14 is provided with a burner tip 18 fixed to the tip of a heavy oil burner 14 by a cap nut 17.
An outer peripheral portion of the heavy oil burner 14 is covered with a distance piece 15, and a cap nut 17 and a burner chip 18 are exposed from a front end portion of the distance piece 15 inside the furnace. A flame stabilizing plate 16 is attached to the distal end of the distance piece 15 inside the furnace. The distance piece 15 is slidably supported on the side wall 2 a of the wind box 2 by the seal box 3 and the gland packing 4. A fuel oil burner cooling air supply port 15a for taking in cooling and sealing air is provided at an end of the distance piece 15 on the fuel oil burner 14 side. Main part of fuel oil burner 14 and distance piece 1
The end of the fuel oil burner 5 on the side of the heavy oil burner 14 is attached to a support member 14a, and the support member 14a is attached to and supported by a heavy oil burner pull-out cylinder 13 that is cantilevered on the furnace wall 1a. In addition, 5 in FIG.
19 is an air register for taking combustion air into the furnace.

In such a conventional cooling device for a heavy oil burner, cooling is performed by flowing cooling air between the heavy oil burner 14 and the distance piece 15 by the blower dedicated to the burner 6. On the other hand, when the burner dedicated blower 6 is used only during boiler hot banking, the air system is as shown in FIG. That is, the air from the non-illustrated push-in ventilator (FDF) of the boiler equipment via the heavy oil burner sealing air inlet check valve 21 is joined to the line coming from the burner dedicated blower 6, and the three-way outlet is provided as burner sealing air during boiler operation. It is supplied from the heavy oil burner cooling air supply port 15a via the switching valve 20. On the other hand, when the burner-only blower 6 is used both during boiler operation and during hot banking, an air system as shown in FIG. Cooling air is supplied to the heavy oil burner cooling air supply port 15a. The aspirating air in FIGS. 4 and 5 is used when the heavy oil burner 14 is mounted or pulled out, and in that case, the three-way opening switching valve 20 is switched and used.

FIG. 6 shows a steam system diagram in which cooling steam is supplied for cooling when such a conventional heavy oil burner is stopped. Heavy oil is supplied to the heavy oil burner 14 via the heavy oil inlet valve 22 and the Barco joint 5,
The steam is similarly sprayed with the steam inlet valve 23 and the Barco joint 5.
Is supplied to the heavy oil burner 14. The steam also branches before the spray steam inlet valve 23 and further branches to a purge steam valve 27 and a cooling steam valve 28, one of which is cooled from the purge cooling steam valve 25 to the heavy oil side via the check valve 24. And the other supplies cooling steam from the purge cooling steam valve 25 to the steam side. The empty steam of the purge steam valve 27 and the cooling steam valve 28 further flows to the drain via the drain valve 26.

[0008]

In the burner cooling air system constituted by the above-mentioned prior art, it is achieved to flow sealing air during cooling and operation of the heavy oil burner.
No measures were taken to minimize the amount of radiant heat from the furnace, and no structural consideration was given to cooling the tip of the heavy oil burner. Therefore, the oil remaining at the tip of the heavy oil burner may be carbonized.

The present invention has been made in view of such a background, and an object of the present invention is to provide a fuel oil burner cooling device that does not carbonize the residual oil of the fuel oil burner.

[0010]

To achieve the above object, the present invention provides a distance piece supported and fixed to a furnace so as to protrude with a predetermined length into the furnace, and a distance piece inside the distance piece. A fuel oil burner provided with a fuel oil burner having a burner portion protrudingly inserted into and retracted from the fuel oil burner, and cooling air supply means for supplying cooling and sealing air to the distance piece into which the burner portion is inserted. The apparatus is characterized in that there is provided a means for supporting the fuel oil burner so that the tip of the burner part can retreat from the tip of the distance piece when the fuel oil burner is extinguished and during boiler hot banking.

[0011] In this case, the cooling air supply means operates also at the time of extinguishing the heavy oil burner and at the time of boiler hot banking, and supplies air from the back side to the tip of the heavy oil burner retreated from the open end of the distance piece. In addition to reducing the amount of radiant heat from the furnace, it prevents combustion air and furnace gas from entering the fuel oil burner chip. The supporting means is constituted by a cylinder means supported by the distance piece so as to perform an advance / retreat operation.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Note that, in the following embodiments, the same reference numerals are given to portions that can be regarded as equivalent to the conventional technology of steam, and redundant description will be omitted as appropriate.

FIG. 1 is a diagram for explaining the structure of a fuel oil burner cooling device according to an embodiment of the present invention. Note that FIG. 2 shows a state in which the heavy oil burner is operating.

In the present invention, the distance piece 15 covering the heavy oil burner 14 is arranged such that the tip inside the furnace is located at the same position as in the prior art, and
Is fixed to the side wall 2a. Therefore, the flame stabilizing plate 16 attached to the furnace tip of the distance piece 15
Is also fixed. The heavy oil burner 14 is movably supported by a heavy oil burner insertion / removal cylinder 13 fixedly supported by a distance piece 15. During operation of the heavy oil burner 14, as shown in FIG.
8 is, for example, 40 mm from the tip of the distance piece 15.
Fuel oil burner insertion / removal cylinder 1
3 controls the position. The burner chip 18
Is attached to the tip of a burner portion 14b protruding from the heavy oil burner 14 main body, and ejects heavy oil from this position. When the fuel oil burner 14 is ignited, the burner portion 14 b may be advanced into the furnace 1 by the fuel oil burner insertion / removal cylinder 13 to a position optimal for combustion of the fuel oil burner 14.

When the fuel oil burner 14 is at rest or during hot banking, the fuel oil burner insertion / removal cylinder 13 controls the positions of the fuel oil burner 14 and the burner portion 14b so that the burner chip 18 is located at the withdrawn position indicated by the dotted line in FIG. . This position is, for example, a position 200 to 300 mm from the distal end of the distance piece 15. The cooling air and the sealing air are controlled to flow from the fuel oil burner cooling air supply port 15a of the fuel oil burner 14 when the furnace temperature is 100 ° C. or more during ignition / digestion and during hot banking. You. The amount of radiant heat from the furnace can be reduced depending on the positional relationship between the tip of the distance piece 15 as an incident port and the burner chip 18 which is the tip of the heavy oil burner 14 as a heat receiving surface. With the structure of this embodiment, the temperature of the heavy oil burner 14 can be set to 150 ° C. or lower, which is the temperature at which the residual oil starts to be carbonized. Thereby, carbonization does not occur, and it becomes possible to eliminate the clogging phenomenon of the heavy oil burner.

That is, the amount of radiant heat from the furnace in the prior art enters the burner opening area and receives heat at the area of the heavy oil burner tip. On the other hand, in the present invention, since the distance piece 15 is fixed and only the heavy oil burner 14 is retracted by about 200 to 300 mm, radiant heat is incident only from the opening area of the distance piece 15.
Thereby, the entrance (the tip of the distance piece 15)
, And a distance from the heat receiving surface (burner chip 18).

According to the present invention, the cooling efficiency can be improved. That is, when the fuel oil burner 14 is stopped, the tip of the fuel oil burner 14 can enter the distance piece 15, so that the tip of the fuel oil burner 14 can be cooled. In addition, the cooling air and the sealing air can shut off the combustion air and the in-furnace gas which are about to enter through the hole of the burner chip 18 of the heavy oil burner 14, so that the temperature rise of the heavy oil burner 14 can be prevented. By reducing the amount of radiation heat received, it is possible to lower the temperature to a temperature lower than the temperature at which carbonization of the residual oil starts (<150 ° C.).

With the fuel oil burner cooling device of the present invention, the cooling steam for the fuel oil burner 14 can be eliminated. That is, the structure of the cooling device in the prior art is
As described above, the fuel oil burner 14 and the distance piece 1
Insertion and removal from the furnace are performed with 5 fixed. The positional relationship between the heavy oil burner 14 and the flame holding plate 16 is determined in consideration of the flammability, and therefore, the burner tip 18 of the heavy oil burner 14 protrudes from the tip of the distance piece 15 supporting the flame holding plate 16 by about 40 to 50 mm. Will be. In order to ensure stable combustion near the burner chip 18, an increase in the amount of cooling air or sealing air is not preferable.
Therefore, there is no air curtain effect due to cooling air or air flow for sealing, and 250 to
High-temperature combustion air such as 350 ° C. and furnace gas enter by convection and carbonize the residual oil. In order to prevent this phenomenon, it was necessary to supply cooling steam to the stopped heavy oil burner during boiler operation. On the other hand, in the present invention, the burner tip 18 of the heavy oil burner 14 is connected to the distance piece 15.
If the cooling air for the heavy oil burner or the air for sealing is sent in this state, it is possible to shut off the entry of high-temperature combustion air and gas in the furnace into the distance piece 15. Yes, no cooling steam is required.

By fixing the distance piece 15 as in the present invention, the temperature of the flame-holding plate 16 and the distal end of the distance piece 15 are increased by the radiant heat from the furnace compared to the prior art configuration. It is most likely to rise when the burner is extinguished. The furnace temperature varies depending on the type of fuel used, but it is necessary to consider the maximum temperature of 1100 ° C for heavy oil and crude oil combustion and 900 ° C for gas combustion . However, recent technology for heat resistance has been improved, and a material that can sufficiently withstand the above-mentioned high temperatures can be selected, so that there is no problem. For example, “Inconel 625” is placed on the flame holding plate 16 and “SU” is placed on the distance piece 15.
S310S "may be used.

[0020]

As is apparent from the above description, according to the present invention, since the burner portion of the heavy oil burner moves within the distance piece, the burner portion is extinguished when the heavy oil burner is extinguished or in hot banking. By drawing the tip of the furnace into the distance piece, the amount of radiant heat received from the furnace can be reduced. This allows
The cooling air and the sealing air can cut off the combustion air and the furnace gas that enter from the front end side of the heavy oil burner. As described above, the cooling property of the tip of the heavy oil burner is greatly improved, and carbonization of the residual oil of the heavy oil burner can be prevented, so that the cleaning interval of the heavy oil burner can be extended. As a result, the reliability of the heavy oil burner increases, and the stable combustion of the boiler can be continued. Further, since the cooling steam during the stoppage of the heavy oil burner is not required, it is possible to increase the boiler efficiency and to reduce the power generation cost. Further, since a cooling steam facility is not required, construction costs and maintenance are not required.

Further, according to the present invention, the cooling air supply means is operated even when the heavy oil burner is extinguished and during boiler hot banking, so that intrusion of the combustion gas and the furnace gas into the burner can be effectively shut off. . In addition, the cooling air can also reduce the amount of radiant heat transferred.

Furthermore, according to the present invention, since the heavy oil burner and the oil supply pipe are movably supported by the cylinder means supported by the distance piece, the advance and retreat operation can be performed with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a structure of a fuel oil burner cooling device according to an embodiment of the present invention.

FIG. 2 is an air system diagram of an example of a conventional fuel oil burner cooling device.

FIG. 3 is an enlarged detail view showing a part of a heavy oil burner section of FIG. 2;

FIG. 4 is an air system diagram when cooling air and burner sealing air during boiler hot banking are taken out by a dedicated blower.

FIG. 5 is an air system diagram when a blower dedicated to a burner is used only during boiler hot banking and FDF outlet air is used during boiler operation.

FIG. 6 is a diagram of a cooling steam system that flows for cooling when the heavy oil burner is stopped.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace 2 Wind box 6 Burner dedicated blower 13 Fuel oil burner removal cylinder 14 Fuel oil burner 14a Support member 14b Burner part 15 Distance piece 15a Fuel oil burner cooling air supply port 16 Flame holding plate 18 Burner chip

Continuation of front page (72) Inventor Naoaki Hotta 5-3 Takaracho, Kure-shi, Hiroshima Fab term in Bab Hitachi Engineering Co., Ltd. (reference) 3K052 GA07 GB04 GC01 GE00 3K091 EB02

Claims (3)

[Claims] 1. A distance piece supported and fixed to the furnace so as to protrude into the furnace with a predetermined length, and a burner portion inserted into the distance piece so as to be able to advance and retreat. A fuel oil burner, comprising: a fuel oil burner; and cooling air supply means for supplying cooling and sealing air into the distance piece into which the burner portion is inserted.When the fuel oil burner is extinguished and during boiler hot banking, A fuel oil burner cooling device comprising: means for supporting the fuel oil burner such that the tip of the burner section can retreat from the tip of the distance piece. 2. The fuel oil burner cooling device according to claim 1, wherein the cooling air supply means is also operated during the fire extinguishing of the fuel oil burner and during boiler hot banking. 3. The fuel oil burner cooling system according to claim 1, wherein said supporting means comprises a cylinder means supported by said distance piece.