JP2013076475A - Boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boiler that can be configured more simply and can be reduced in noise.SOLUTION: The boiler 1 includes: a boiler body 10 which includes a combustion chamber 17, a plurality of water pipes 12 annularly arranged so as to encircle the combustion chamber, a boiler housing 11 disposed at an outer side of the plurality of water pipes and a combustion gas discharging part 15 provided at the boiler housing 11 and discharging a combustion gas generated in the combustion chamber 17 therefrom; an exhaust tube 20 which is connected to the combustion gas discharging part 15 and includes an exhaust gas flow passage 21 through which the combustion gas discharged from the boiler body 10 flows; and an exhaust noise reducing member 30 which is disposed between the boiler body 10 and the exhaust tube 20 so as to block the combustion gas discharging part 15 and configured in a plate shape, and in which an exhaust gas flow passage hole 31 with an area smaller than a cross-section area of the exhaust gas flow passage 21 is formed.

Description

  The present invention relates to a boiler. More specifically, the present invention relates to a boiler that can reduce noise generated with fuel combustion.

Conventionally, a boiler that heats water and generates steam or hot water is composed of a combustion chamber in which fuel such as heavy oil and light oil is burned, a plurality of water pipes arranged to surround the combustion chamber, and a plurality of water pipes. And a boiler casing disposed on the outside.
In the above boiler, as the fuel burns in the combustion chamber, the pressure in the combustion chamber (inside the can) (hereinafter referred to as the furnace pressure) changes with a predetermined amplitude. And the vibration of the air which arises in the inside of a combustion chamber by the change of this furnace pressure propagates to the external space of a boiler as noise. In particular, in the case of a boiler having a small pressure loss in the can body, when the amplitude of the furnace pressure increases, low-frequency vibrations generated by the large furnace pressure amplitude propagate to the external space.
In order to reduce such noise generated from a boiler, a boiler in which a sound absorbing material is attached to the inside of a can body has been proposed (see Patent Documents 1 and 2).

JP 7-217810 A JP 2002-89802 A

According to the boilers proposed in Patent Documents 1 and 2, vibration and noise generated inside the can body can be absorbed by the sound absorbing material.
However, in the boilers proposed in Patent Documents 1 and 2, since it is necessary to attach the sound absorbing material to the inside of the can body, the boiler manufacturing process becomes complicated.

  Therefore, an object of this invention is to provide the boiler which can be comprised more simply and can reduce a noise.

  The present invention is provided in a combustion chamber in which fuel is combusted, a plurality of water tubes arranged in an annular shape so as to surround the combustion chamber, a boiler housing disposed outside the plurality of water tubes, and the boiler housing. A can body having a combustion gas discharge portion for discharging combustion gas generated in the combustion chamber, and an exhaust flow passage connected to the combustion gas discharge portion and through which the combustion gas discharged from the can body flows. And an exhaust pipe having an area smaller than the cross-sectional area of the exhaust flow passage. The exhaust pipe is disposed between the can body and the exhaust pipe so as to close the combustion gas discharge portion. It is related with a boiler provided with the exhaust noise reduction member in which the exhaust circulation hole was formed.

  Moreover, it is preferable that the said exhaust noise reduction member is further provided with the division part which divides the said exhaust flow hole into several exhaust flow small holes.

  Moreover, it is preferable that the said partition part is formed in the cross shape which divides the said exhaust circulation hole into four equally.

  Further, the exhaust circulation hole is formed in a circular shape, and the plurality of exhaust circulation small holes are formed in a linear shape in a portion partitioned by the partition portion and in an arc shape in a portion not partitioned by the partition portion. It is preferred that

  The area of the exhaust circulation hole is preferably 15% to 20% of the cross-sectional area of the exhaust flow passage.

The present invention also provides a combustion chamber in which fuel is combusted, a plurality of water pipes arranged in an annular shape so as to surround the combustion chamber, a casing arranged outside the plurality of water pipes, and the casing. A can body comprising a combustion gas discharge part for discharging the combustion gas generated in the combustion chamber;
An exhaust pipe connected to the combustion gas discharge section and having an exhaust flow passage through which the combustion gas discharged from the can body circulates, and a method for reducing exhaust noise in a boiler,
An exhaust noise reduction member is disposed between the can body and the exhaust cylinder and is configured in a plate shape and has an exhaust noise reduction member in which an exhaust circulation hole having an area smaller than a cross-sectional area of the exhaust flow passage is formed. It relates to a reduction method.

  ADVANTAGE OF THE INVENTION According to this invention, the boiler which can be comprised simply and can reduce a noise can be provided.

It is a figure which shows one Embodiment of the boiler of this invention. It is a figure which decomposes | disassembles and shows the boiler shown in FIG. It is the XX sectional view taken on the line of FIG. It is a figure which shows one Embodiment of the orifice member of this invention, Fig.4 (a) shows a top view, FIG.4 (b) shows a side view. Fig.5 (a)-FIG.5 (g) are each a top view which shows the other form of an orifice member.

Hereinafter, preferred embodiments of the boiler of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the boiler 1 of the present embodiment includes a can body 10, an exhaust cylinder 20, and an orifice member 30 as an exhaust noise reduction member.

As shown in FIGS. 1 and 2, the can body 10 includes a boiler housing 11, a plurality of water pipes 12, a lower header 13, an upper header 14, a combustion gas discharge unit 15, a burner 16, Is provided. A combustion chamber 17 and a combustion gas passage 18 are formed inside the can body 10.
The boiler housing 11 is configured in a cylindrical shape and constitutes a main part of the outer shape of the can body 10. The boiler casing 11 is arranged such that the height direction is along the vertical direction. An opening 111 is formed in the upper part of the peripheral surface of the boiler housing 11.

The plurality of water tubes 12 are arranged extending in the vertical direction inside the boiler casing 11. As shown in FIGS. 1 to 3, the plurality of water pipes 12 constitute an inner water pipe group 121 and an outer water pipe group 122 arranged outside the inner water pipe group 121. The inner water pipe group 121 is configured by arranging a plurality of water pipes 12 in an annular shape so as to be coaxial with the central axis of the boiler casing 11. In the present embodiment, as shown in FIG. 3, the inner water pipe group 121 includes water pipes 12 arranged adjacent to each other except a portion located on the opposite side to the side where the opening 111 is formed in the boiler casing 11. Are arranged in contact with each other.
The outer water tube group 122 is configured to be arranged in an annular shape so that the plurality of water tubes 12 are coaxial with the central axis of the boiler casing 11. Further, the outer water tube group 122 is arranged in the vicinity of the inner surface of the boiler casing 11 so that a predetermined space is formed between the outer water tube group 121 and the inner water tube group 121. In other words, the boiler housing 11 is disposed outside the outer water tube group 122 (the plurality of water tubes 12).

The lower header 13 is disposed at the lower part inside the boiler casing 11. The lower header 13 is constituted by an annular container. The lower header 13 is connected to lower ends of the plurality of water pipes 12 (the inner water pipe group 121 and the outer water pipe group 122).
The upper header 14 is disposed in the upper part inside the boiler casing 11. The upper header 14 is constituted by an annular container. The upper header 14 is connected to the upper ends of a plurality of water tubes 12 (the inner water tube group 121 and the outer water tube group 122).

The combustion gas discharge unit 15 is disposed at the upper part of the boiler casing 11. More specifically, the combustion gas discharge part 15 is configured in a cylindrical shape having a bent part 151 bent approximately 90 degrees. And the combustion gas discharge part 15 is connected with the boiler housing | casing 11 so that the base end part 152 of the combustion gas discharge part 15 may block | close the opening 111. FIG. As shown in FIGS. 1 and 2, the front end 153 of the combustion gas discharge unit 15 is open upward. A flange portion 154 extending outward is formed at the front end portion 153 of the combustion gas discharge portion 15, and a plurality of flange portions 154 are provided at predetermined intervals in the circumferential direction. Bolt insertion holes 155 (see FIG. 2) are formed.
The cross-sectional area of the combustion gas flow passage in the combustion gas discharge portion 15 is configured to be approximately equal to the opening area of the opening 111 of the boiler casing 11.

  The burner 16 is disposed at the center of the upper surface of the boiler casing 11. The burner 16 includes a fuel injection nozzle and an air supply nozzle (both not shown). The burner 16 injects fuel from the fuel injection nozzle toward the inside of the boiler casing 11, and supplies air from the air supply nozzle to the inside of the boiler casing 11 to burn the fuel.

As shown in FIGS. 1 to 3, the combustion chamber 17 is constituted by a space surrounded by the inner water tube group 121. In other words, the inner water tube group 121 (the plurality of water tubes 12) is annularly disposed so as to surround the combustion chamber 17. In the combustion chamber 17, the fuel injected from the fuel injection nozzle of the burner 16 is combusted to generate combustion gas.
As shown in FIGS. 1 and 2, the combustion gas passage 18 is configured by a space between the outside of the inner water tube group 121 and the inner surface of the boiler casing 11. The combustion gas generated in the combustion chamber 17 flows through the combustion gas passage 18.

As shown in FIGS. 1 and 2, the exhaust cylinder 20 is configured in a cylindrical shape having an exhaust flow passage 21. The exhaust cylinder 20 is connected to the combustion gas discharge unit 15 via an orifice member 30 described later. More specifically, the exhaust cylinder 20 is configured by a cylindrical member having a substantially uniform thickness. A flange portion 22 extending outward is formed at the base end portion of the exhaust tube 20, and a plurality of bolts provided at predetermined intervals in the circumferential direction are inserted into the flange portion 22. A hole 23 (see FIG. 2) is formed.
The cross-sectional area of the exhaust flow passage 21 of the exhaust cylinder 20 is configured to be approximately equal to the cross-sectional area of the combustion gas flow passage in the combustion gas discharge unit 15.
The exhaust gas 20 circulates through the combustion gas passage 18 and the combustion gas discharged from the can body 10 (combustion gas discharge unit 15) flows through the exhaust pipe 20 described above.

  As shown in FIG. 4A, the orifice member 30 is disposed between the combustion gas discharge part 15 and the exhaust cylinder 20 in the can body 10. As shown in FIGS. 4A and 4B, the orifice member 30 is configured in a plate shape, and has an exhaust circulation hole 31, a partition portion 32 that partitions the exhaust circulation hole 31, and a plurality of bolts. And an insertion hole 33.

The orifice member 30 is configured in a disc shape having substantially the same shape and the same size as the outer shape of the flange portion 154 provided in the can body 10 (combustion gas discharge portion 15) and the outer shape of the flange portion 22 provided in the exhaust cylinder 20. The
The exhaust circulation hole 31 is formed in the central portion of the orifice member 30. The exhaust circulation hole 31 has an area smaller than the cross-sectional area of the exhaust flow passage 21. In the present embodiment, the exhaust circulation hole 31 is formed in a circular shape.

  The partition part 32 partitions the exhaust circulation hole 31 into a plurality of exhaust circulation small holes 311. In this embodiment, the partition part 32 is formed in a cross shape and divides the circular exhaust circulation hole 31 into approximately four equal parts. That is, the partition part 32 partitions the exhaust circulation hole 31 into four fan-shaped exhaust circulation small holes 311.

Here, if the cross-sectional area of the exhaust passage 21 is about 700cm ² ~1500cm ^2, the area of the exhaust passage holes 31 (the total area of the plurality of exhaust flow eyelet 311), from the viewpoint of suitably preventing noise of the low frequency, Preferably, it is 15% to 20% of the cross-sectional area of the exhaust flow passage 21.
When the area of the exhaust flow hole 31 is less than 15% of the cross-sectional area of the exhaust flow passage 21, the pressure loss of the can 10 becomes too large, and the power of the blower that introduces air into the combustion chamber 17 is increased. There is a need to increase it. Further, when the area of the exhaust circulation hole 31 exceeds 20% of the cross-sectional area of the exhaust flow passage 21, the effect of reducing low-frequency noise is reduced.

  The plurality of bolt insertion holes 33 are disposed in the vicinity of the outer edge of the orifice member 30 at a predetermined interval in the circumferential direction. The plurality of bolt insertion holes 33 are formed in a bolt insertion hole 155 formed in the flange portion 154 provided in the can body 10 and a bolt insertion hole 23 formed in the flange portion 22 provided in the proximal end portion of the exhaust tube 20. It is formed at the corresponding position.

  As shown in FIGS. 1 and 2, the above orifice member 30 is interposed between the combustion gas discharge part 15 and the exhaust cylinder 20 so as to block the combustion gas discharge part 15. The orifice member 30 disposed between the combustion gas discharge portion 15 and the exhaust cylinder 20 is configured by inserting a plurality of bolts 40 connecting the can body 10 and the exhaust cylinder 20 through the plurality of bolt insertion holes 33. It is fixed between the can 10 and the exhaust tube 20.

The shape of the exhaust flow hole 31 of the orifice member 30 is not limited to the shape shown in FIGS. 4 (a) and 5 (a).
For example, as shown in FIG. 5B, the exhaust circulation holes 31 may be formed in a square shape, and the exhaust circulation holes 31 may be partitioned into four square exhaust circulation small holes 311 by a cross-shaped partition portion 32.
Further, as shown in FIGS. 5C and 5D, the orifice member 30 may be configured by forming a plurality of circular or triangular exhaust circulation holes 31 in the central portion.
Further, as shown in FIGS. 5 (e) to 5 (g), an orifice member 30 having a single exhaust circulation hole 31 having a circular shape, a triangular shape, or a square shape may be used without providing the partition portion 32.

In the boiler 1 described above, first, fuel is burned in the combustion chamber 17. Here, combustion gas is generated with the combustion of the fuel in the combustion chamber 17, and the pressure inside the combustion chamber 17 (can body 10) (hereinafter referred to as the furnace pressure) changes with a predetermined amplitude. Next, the combustion gas generated in the combustion chamber 17 heats the water flowing through the plurality of water pipes 12 (inner water pipe group 121) arranged so as to surround the combustion chamber 17. Next, the combustion gas heats the water flowing from the combustion chamber 17 through the combustion gas passage 18 and further through the plurality of water pipes 12 (the inner water pipe group 121 and the outer water pipe group 122). Then, the combustion gas that has passed through the combustion gas passage 18 moves from the combustion gas discharge portion 15 to the exhaust pipe 20.
Here, in the present embodiment, the combustion gas generated in the combustion chamber 17 is not provided with the inner water tube group 121 provided in a portion located on the opposite side of the boiler casing 11 from the side where the opening 111 is formed. From the part, it moves to the combustion gas passage 18. Then, the combustion gas that has moved from the combustion chamber 17 to the combustion gas passage 18 divides into two hands and circulates through the combustion gas passage 18 as shown in FIG.

  In addition, water is supplied into the plurality of water pipes 12 from a lower header 13 disposed below the plurality of water pipes 12. And the water heated in the inside of the some water pipe 12 turns into a vapor | steam, and is supplied to a steam supply pipe (not shown) from the upper header 14.

  Here, an orifice member 30 is disposed at a connection portion between the combustion gas discharge portion 15 and the exhaust cylinder 20. Thereby, the flow rate of the combustion gas flowing from the combustion gas discharge part 15 to the exhaust pipe 20 is suppressed by the orifice member 30. Then, by suppressing the flow rate of the combustion gas flowing from the combustion gas discharge portion 15 to the exhaust pipe 20, a predetermined pressure loss occurs in the can body 10, and the amplitude of the furnace pressure becomes small.

  According to the boiler 1 of this embodiment demonstrated above, there exist the following effects.

  (1) An orifice member 30 in which an exhaust circulation hole 31 having a smaller area than the cross-sectional area of the exhaust flow passage 21 is formed between the combustion gas discharge portion 15 and the exhaust cylinder 20 in the can body 10. Thereby, since the flow volume of the exhaust_gas | exhaustion discharged | emitted from the can 10 (combustion gas discharge part 15) to the exhaust pipe 20 can be suppressed, the amplitude of a furnace pressure can be made small. Therefore, it is possible to reduce the low-frequency vibration that is generated as the fuel is burned in the combustion chamber 17, and it is possible to reduce the generation of noise due to the low-frequency vibration. In addition, the flow rate of the combustion gas discharged from the can body 10 can be adjusted without configuring the exhaust cylinder 20 to be thin. Therefore, it is possible to prevent a combustion failure at the start of combustion due to the narrow configuration of the exhaust cylinder 20, and to reduce the difference between the pressure loss at the start of combustion and the pressure loss at the time of steady combustion.

  (2) The orifice member 30 for reducing noise is disposed in the connecting portion between the can body 10 and the exhaust tube 20. Thereby, it is possible to reduce noise with a simple configuration without disposing a member for reducing noise inside the can 10. Further, the orifice member 30 can be easily attached to an existing boiler without performing a large-scale construction.

  (3) The orifice member 30 is configured including the partition portion 32, and the exhaust circulation hole 31 is configured by a plurality of exhaust circulation small holes 311. Thereby, the flow of the combustion gas passing through the exhaust circulation holes 31 (the plurality of exhaust circulation small holes 311) can be rectified, and the noise generated when the combustion gas passes through the exhaust circulation holes 31 can be reduced. Therefore, it is possible to reduce the generation of sound due to the arrangement of the orifice member 30 while reducing the generation of noise due to low frequency vibration.

  (4) The partition part 32 is formed in a cross shape, and the plurality of exhaust circulation small holes 311 are formed in a shape obtained by dividing the exhaust circulation hole 31 into approximately four equal parts. Thereby, since the rectification effect by the several exhaust circulation small hole 311 can be improved more, generation | occurrence | production of the sound resulting from arrange | positioning the orifice member 30 can be reduced more.

  (5) The area of the exhaust flow holes 31 (the total area of the plurality of exhaust flow small holes 311) was set to 15% to 20% of the cross-sectional area of the exhaust flow passage 21. Thereby, it is possible to prevent the pressure loss of the can body 10 from becoming excessively large while preferably obtaining a low-frequency noise reduction effect.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
In the following embodiments, orifice members 30 and 30b to 30g (see FIGS. 5A to 5G) in which exhaust circulation holes having different shapes are formed are used in a boiler (manufactured by Miura Kogyo Co., Ltd.). The boilers of Examples 1 to 7 were installed by being interposed at the connection portion between the can body and the exhaust pipe. Moreover, the boiler which has not attached the orifice member was made into the boiler of a comparative example.

The boilers of Examples 1 to 7 and the comparative example were operated, and the noise generated from the boiler was evaluated.
Low-frequency noise generated from the boiler is placed at a position about 2 m away from the front of the boiler, with a low-frequency sound level meter (trade name: NA-18A, manufactured by Rion Co., Ltd.) and 1/3 octave band analysis for 10 seconds ( The maximum value of the center frequency (12.5 Hz) was measured. The evaluation results are shown in Table 1 below.

［騒音の評価］
×：低周波騒音が発生した。
△：低周波騒音はなくなったが、排ガス流通穴を通過するときに発生すると考えられる笛吹音が発生した。
○：低周波騒音はなくなったが、わずかな笛吹音が発生した。
◎：低周波騒音はなく、かつ、笛吹音も発生しなかった。

[Evaluation of noise]
X: Low frequency noise was generated.
Δ: Low-frequency noise disappeared, but whistling sound that was thought to be generated when passing through the exhaust gas circulation hole was generated.
○: Low frequency noise disappeared, but a slight whistling sound was generated.
A: There was no low-frequency noise, and no whistling sound was generated.

  As shown in Table 1, in the boilers of Examples 1 to 7 to which the orifice member was attached, the generation of low frequency noise could be suppressed. In addition, in the boilers of Examples 6 and 7 to which the orifice member having a single exhaust circulation hole was attached, whistling sound that was considered to be caused by the arrangement of the orifice member was generated, but the exhaust circulation was caused by a plurality of exhaust circulation small holes. Compared with the boilers of Examples 6 and 7, the whistling sound was reduced in the boilers to which the orifice members of Examples 1 to 4 configured with holes were attached. Furthermore, in the boiler according to the first embodiment in which the circular exhaust circulation hole is divided into four fan-shaped exhaust circulation small holes by the cross-shaped partition portion, the generation of low-frequency noise and the generation of whistle blowing noise are prevented. I was able to.

As mentioned above, although each preferred embodiment of the present invention was described, the present invention is not limited to each embodiment mentioned above, and can be changed suitably.
For example, the shape of the exhaust flow hole in the orifice member is not limited to the shape described above.

DESCRIPTION OF SYMBOLS 1 Boiler 10 Can body 11 Boiler housing | casing 12 Water pipe 15 Combustion gas discharge part 17 Combustion chamber 18 Combustion gas passage 20 Exhaust pipe 21 Exhaust flow passage 30 Orifice member (exhaust noise reduction member)
31 Exhaust flow hole 32 Partition 311 Exhaust flow small hole

Claims (6)

A combustion chamber in which fuel is combusted, a plurality of water tubes arranged in an annular shape so as to surround the combustion chamber, a boiler housing disposed outside the plurality of water tubes, and the combustion chamber provided in the boiler housing A can having a combustion gas discharge part for discharging the combustion gas generated in
An exhaust pipe having an exhaust flow passage connected to the combustion gas discharge section and through which the combustion gas discharged from the can body flows;
The exhaust gas distribution hole is formed between the can body and the exhaust pipe so as to close the combustion gas discharge part, is configured in a plate shape, and has an area smaller than a cross-sectional area of the exhaust flow passage. A boiler comprising an exhaust noise reduction member.   The boiler according to claim 1, wherein the exhaust noise reduction member further includes a partition portion that partitions the exhaust circulation hole into a plurality of exhaust circulation small holes.   The boiler according to claim 2, wherein the partition portion is formed in a cross shape that divides the exhaust circulation hole into approximately four equal parts. The exhaust circulation hole is formed in a circular shape,
4. The boiler according to claim 2, wherein the plurality of exhaust circulation small holes are formed such that a portion partitioned by the partition portion is formed in a straight line, and a portion not partitioned by the partition portion is formed in an arc shape.   The boiler according to any one of claims 1 to 4, wherein an area of the exhaust circulation hole is 15% to 20% of a cross-sectional area of the exhaust flow passage. A combustion chamber in which fuel is combusted, a plurality of water pipes arranged in an annular shape so as to surround the combustion chamber, a casing arranged outside the plurality of water pipes, and provided in the casing and generated in the combustion chamber A can having a combustion gas discharge part for discharging the burned combustion gas;
An exhaust pipe connected to the combustion gas discharge section and having an exhaust flow passage through which the combustion gas discharged from the can body circulates, and a method for reducing exhaust noise in a boiler,
An exhaust noise reduction member is disposed between the can body and the exhaust cylinder and is configured in a plate shape and has an exhaust noise reduction member in which an exhaust circulation hole having an area smaller than a cross-sectional area of the exhaust flow passage is formed. Reduction method.

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