JP5754583B2 - Burner and boiler - Google Patents

Description

  The present invention relates to a burner having a plurality of nozzles and a boiler having such a burner.

  Conventionally, a burner having two nozzles, a high combustion nozzle and a low combustion nozzle, is known. In this type of burner, fuel is sprayed only from the low combustion nozzle during low combustion, and fuel is sprayed from both the high combustion nozzle and the low combustion nozzle during high combustion.

  Since this type of burner includes two nozzles, a high combustion nozzle and a low combustion nozzle, the middle point between the two nozzles is usually arranged in accordance with the burner central axis. Therefore, all the nozzles are arranged eccentrically from the burner central axis. Therefore, the flame is biased in the combustion chamber, and there is room for improvement in combustibility.

  Therefore, as disclosed in the following Patent Document 1, in order to improve the combustibility at the time of low combustion, the low combustion nozzle (4) is made to have a burner central axis (8) (combustion) rather than the high combustion nozzle (5). The burner (1) arrange | positioned so that it may become close to a chamber central axis (7)) is proposed.

JP 2003-302010 A

  However, when combustion is sprayed from two nozzles, a high combustion nozzle and a low combustion nozzle, at the time of high combustion in the first place, the fuel and flame from each nozzle overlap, and a high temperature part is locally generated. It is inevitable that it will be done.

  The problem to be solved by the present invention is to provide a burner and a boiler that improve the combustibility of each combustion stage.

The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is provided with a plurality of nozzles having different spraying amounts, and alternatively, from which nozzle is sprayed. A burner that changes the combustion amount by switching, and the nozzle with the largest spray amount is arranged along the burner central axis or closer to the burner central axis than the other nozzles, and the nozzle for high combustion A burner that changes the amount of combustion at four positions of high combustion, medium combustion, low combustion, and stop, and sprays fuel only from the high combustion nozzle during high combustion The fuel is sprayed only from the middle combustion nozzle at the time of middle combustion, the fuel is sprayed only from the low combustion nozzle at the time of low combustion, and the amount of spray from the middle combustion nozzle is lower than that of the high combustion nozzle, but low combustion. More than for nozzle The high combustion nozzles are arranged along the burner central axis or closer to the burner central axis than the medium and low combustion nozzles, and the medium combustion nozzle is low combustion By disposing the nozzle closer to the burner central axis than the nozzle for use, the nozzle having a larger spray amount is arranged closer to the burner central axis .

  According to the first aspect of the present invention, among the plurality of nozzles having different spray amounts, the nozzle that is sprayed alternatively according to the combustion stage is switched, and fuel is supplied from only one nozzle in each combustion stage. Is sprayed. Thereby, the overlap of the fuel and flame from each nozzle can be prevented, the generation of a local high temperature portion can be prevented, and the combustibility can be improved. In addition, since the nozzle with the maximum spray amount is arranged along the burner central axis or closer to the burner central axis than the other nozzles, the flammability at the maximum combustion can be best improved. .

According to the first aspect of the present invention, since fuel is sprayed only from the high combustion nozzle even during high combustion, fuel and flame overlap as compared with the case where spray from the low combustion nozzle is also used. It is possible to prevent the occurrence of local high temperature parts and improve the combustibility. In addition, since the high combustion nozzle is disposed along the burner central axis or closer to the burner central axis than the low combustion nozzle, the combustibility during high combustion can be improved most.

According to the first aspect of the present invention, even in the four-position control burner, the fuel is sprayed from only one nozzle in each combustion stage, thereby preventing the overlap of the fuel and the flame. Generation of a high temperature part can be prevented and combustibility can be improved. In addition, since the high combustion nozzle is disposed along the burner central axis or closer to the burner central axis than the other nozzles, the combustibility during high combustion can be best improved.

Furthermore, in the invention according to claim 2 , the burner is provided downward in the center of the upper part of the cylindrical combustion chamber, and the high combustion nozzle is arranged along the central axis of the combustion chamber, It is arrange | positioned so that it may become closer to a combustion chamber central axis rather than another nozzle, It is a boiler provided with the burner of Claim 1 characterized by the above-mentioned.

According to the second aspect of the invention, the high combustion nozzle is arranged along the combustion chamber central axis, or arranged closer to the combustion chamber central axis than the other nozzles, so that the high combustion nozzle can be used. A boiler with the best flammability can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the burner and boiler which improved the combustibility of each combustion stage are realizable.

It is a schematic longitudinal cross-sectional view which shows one Example of the burner of this invention. It is an enlarged view of the nozzle front-end | tip part of the burner in FIG. It is a III-III arrow line view in FIG.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic longitudinal sectional view showing an embodiment of the burner of the present invention. 2 is an enlarged view of the nozzle tip of the burner in FIG. 1, and FIG. 3 is a view taken in the direction of arrows III-III in FIG.

  The burner 1 of this embodiment is a burner for burning liquid fuel, and includes two nozzles, a high combustion nozzle 2 and a low combustion nozzle 3. Each of the nozzles 2 and 3 is configured by providing nozzle tips 6 and 7 at the tip ends of the nozzle pipes 4 and 5, respectively.

  Each of the nozzles 2 and 3 is disposed along the axis in the vertical direction, and is provided close to each other in parallel. At this time, the nozzle tips 6 and 7 of the nozzles 2 and 3 are arranged close to each other at the same height.

  The low combustion nozzle 3 is provided with an ignition device 8. Specifically, an ignition insulator 9 is provided in the vicinity of the low combustion nozzle 3, and a spark is generated between the electrodes 10, 10 at the lower end portion thereof to ignite the fuel sprayed from the low combustion nozzle 3. be able to.

  Fuel from the oil tank 11 can be supplied to the nozzles 2 and 3 via the oil supply passage 12. Specifically, the oil supply passage 12 from the oil tank 11 is branched into two branches after passing through the fuel pump 13 and the fuel main valve 14, and one oil supply passage 15 is connected to the high combustion fuel valve 16 through the high combustion fuel valve 16. Connected to the combustion nozzle 2, the other oil supply passage 17 is connected to the low combustion nozzle 3 via a low combustion fuel valve 18.

  The fuel source valve 14 is maintained in an open state during operation of the boiler. Accordingly, when the high combustion fuel valve 16 is opened while the fuel pump 13 is operated, fuel is supplied to the high combustion nozzle 2 and fuel is sprayed downward from the nozzle tip 6 in a substantially conical shape. On the other hand, when the low combustion fuel valve 18 is opened while the fuel pump 13 is operated, fuel is supplied to the low combustion nozzle 3 and the fuel is sprayed downward from the nozzle tip 7 in a substantially conical shape.

  In this embodiment, the burner 1 is controlled in combustion quantity at three positions of high combustion, low combustion and stop, but at low combustion, fuel is sprayed only from the low combustion nozzle 3 and at high combustion, low combustion is performed. Fuel is not sprayed from the nozzle 3 for fuel, but fuel is sprayed only from the nozzle 2 for high combustion. The ratio of the spray amount (spray flow rate) between the low combustion nozzle 3 and the high combustion nozzle 2 is typically 1 to 2, but the spray amount of the high combustion nozzle 2 is the spray amount of the low combustion nozzle 3. As long as it is larger than the amount, the ratio of the spray amount can be changed as appropriate.

  The burner 1 further includes a rectifying cylinder 19 and an air register 20 so as to surround the nozzles 2 and 3. Each of the rectifying cylinder 19 and the air register 20 is cylindrical, and is arranged in a concentric cylinder shape with its axis line arranged in the vertical direction. The nozzles 2 and 3 are held in a state where the nozzles 2 and 3 are inserted from the upper opening of the rectifying cylinder 19 to the vicinity of the lower end at the radial center of the rectifying cylinder 19. Thus, the rectifying cylinder 19 is provided so as to surround each of the nozzles 2 and 3, and the air register 20 is provided so as to surround the rectifying cylinder 19. The lower end portions of the nozzles 2 and 3 are disposed slightly above the lower end portions of the rectifying cylinder 19 and the air register 20. Further, the upper end portion of the air register 20 is formed in an inverted truncated cone shape that increases in diameter as it goes upward.

  A baffle plate 21 is provided in the lower opening of the rectifying cylinder 19. The baffle plate 21 is a baffle plate provided so as to close the lower opening of the rectifying cylinder 19, and corresponds to the nozzle chips 6 and 7 and the lower end portions of the ignition device 8 as shown in FIGS. 2 and 3. Openings 22 are formed at the locations.

  An air opening forming plate 23 is provided at the lower end of the cylindrical space between the rectifying cylinder 19 and the air register 20 as desired. In the present embodiment, an air opening forming plate 23 made of an annular plate material is provided, and the air opening forming plate 23 is formed with a plurality of openings 24, 24,. When the air opening forming plate 23 having a plurality of openings 24 is used, the flame from the burner 1 is divided to increase the surface area of the flame, and the generation of NOx can be prevented by reducing the flame temperature due to heat dissipation. . However, the number and shape of the openings 24 provided in the air opening forming plate 23 can be appropriately changed. In some cases, the installation of the air opening forming plate 23 may be omitted, and the entire area of the cylindrical space between the rectifying cylinder 19 and the air register 20 may be opened.

  The burner 1 further includes a substantially cylindrical window box 25 that opens only downward. A flange 27 provided on the outer periphery of the air register 20 is held by an annular mounting plate 26 provided near the lower opening of the wind box 25. Thus, the window box 25 opens downward only through the opening 22 of the rectifying cylinder 19 and the opening 24 of the air register 20.

  An air path 28 from a blower (not shown) is connected to the upper part of the peripheral side wall of the wind box 25. Accordingly, the air from the blower is sent to the upper openings of the rectifying cylinder 19 and the air register 20 via the air passage 28 and the wind box 25. The air passes through the inside of the rectifying cylinder 19 and is discharged from the opening 22 of the baffle plate 21, and passes through the cylindrical space between the rectifying cylinder 19 and the air register 20 from the opening 24 of the air opening forming plate 23. Discharged. When fuel is sprayed from the nozzles 2 and 3 and combustion is performed, the position corresponding to the amount of combustion is controlled by controlling the position of a damper (not shown) provided in the air passage and / or the rotational speed of the blower. Is fed into the combustion chamber as combustion air.

  Such a burner 1 is provided on the top of the can 30 of the boiler 29. The can 30 is typically configured by arranging a large number of water tubes in a cylindrical shape. And the burner 1 is provided in the radial center upper part of the cylindrical water pipe row | line toward downward. The fuel discharged from the burner 1 is burned inside the cylindrical water tube row. That is, the inside of the cylindrical water tube row functions as a combustion chamber.

  In the present embodiment, the high combustion nozzle 2 is disposed along the burner central axis X or is disposed closer to the burner central axis X than the low combustion nozzle 3. The burner central axis X is the central axis of the rectifying cylinder 19 and usually coincides with the central axis of the can 30 or the combustion chamber.

  In the boiler 29 of this embodiment, the amount of combustion is controlled at three positions: high combustion, low combustion, and stop. As is well known, the amount of combustion can be controlled by a pressure sensor (including a pressure switch) by monitoring the use load of steam based on the steam pressure from the boiler 29.

  As described above, in this embodiment, fuel is sprayed only from the high combustion nozzle 2 during high combustion, and fuel is sprayed from only the low combustion nozzle 3 during low combustion. When starting the boiler 29 from the stopped state, the sprayed fuel from the low combustion nozzle 3 may be ignited using the ignition device 8, and at the time of transition from the low combustion state to the high combustion state, After the flame of the sprayed fuel from the nozzle 3 is transferred to the sprayed fuel from the high combustion nozzle 2, spraying of the fuel from the low combustion nozzle 3 may be stopped.

  According to the burner 1 and the boiler 29 of the present embodiment, since fuel is sprayed only from the high combustion nozzle 2 even during high combustion, compared with the case where the spray from the low combustion nozzle 3 is also used, It is possible to prevent the overlapping of flames, prevent the occurrence of local high temperature parts, and improve the combustibility. In addition, since the high combustion nozzle 2 is arranged along the burner central axis X or closer to the burner central axis X than the low combustion nozzle 3, the combustibility at the time of high combustion is best improved. be able to.

  The burner 1 and the boiler 29 of the present invention are not limited to the configuration of the above embodiment, and can be changed as appropriate. For example, in the above embodiment, the two nozzles of the high combustion nozzle 2 and the low combustion nozzle 3 are provided, but a middle combustion nozzle may be further provided. In this case, the burner 1 changes the amount of combustion at four positions of high combustion, medium combustion, low combustion, and stop. The amount of spray from the middle combustion nozzle is set to be smaller than the high combustion nozzle 2 but larger than the low combustion nozzle 3. Also in this case, fuel is sprayed only from the high combustion nozzle 2 during high combustion, fuel is sprayed only from the middle combustion nozzle during medium combustion, and fuel is sprayed from only the low combustion nozzle 3 during low combustion. The high combustion nozzle 2 is arranged along the burner central axis X, or arranged closer to the burner central axis X than the middle combustion nozzle and the low combustion nozzle 3. The middle combustion nozzle is preferably arranged so as to be the same as or closer to the burner central axis X than the low combustion nozzle 3. That is, it is preferable that the nozzles with a larger spray amount are arranged closer to the burner central axis X.

  Furthermore, the number of nozzles is not limited to two or three, and may be more than that. That is, the present invention can be applied to a burner that includes a plurality of nozzles having different spraying amounts, and that selectively changes which nozzle is sprayed from the nozzles to change the combustion amount. Then, the nozzle with the largest spray amount may be arranged along the burner central axis X, or may be arranged closer to the burner central axis X than the other nozzles.

1 Burner 2 High Combustion Nozzle 3 Low Combustion Nozzle 19 Rectifier 20 Air Register 29 Boiler X Burner Center Axis

Claims (2)

A burner comprising a plurality of nozzles with different spraying amounts, and selectively switching from which nozzle to spray to change the combustion amount,
The nozzle with the maximum spray amount is arranged along the burner central axis or closer to the burner central axis than the other nozzles ,
A burner comprising a high combustion nozzle, a middle combustion nozzle, and a low combustion nozzle, and changing the combustion amount at four positions of high combustion, medium combustion, low combustion and stop,
Fuel is sprayed only from the high combustion nozzle during high combustion, fuel is sprayed only from the middle combustion nozzle during medium combustion, and fuel is sprayed from only the low combustion nozzle during low combustion,
The amount of spray from the medium combustion nozzle is set to be smaller than the high combustion nozzle but larger than the low combustion nozzle,
The high combustion nozzle is arranged along the burner central axis or closer to the burner central axis than the medium combustion nozzle and the low combustion nozzle, and the medium combustion nozzle is more than the low combustion nozzle. A burner characterized in that a nozzle having a larger spray amount is arranged closer to the burner central axis by being arranged closer to the burner central axis . In the upper center of the cylindrical combustion chamber, the burner is provided downward,
2. The burner according to claim 1 , wherein the high combustion nozzle is disposed along a combustion chamber central axis or closer to the combustion chamber central axis than other nozzles. boiler.

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