JP2008175453A - Burner and boiler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burner reducing noxious substance using at least either liquid fuel or gas fuel. <P>SOLUTION: A burner 40 comprises a fuel jet part 42 jetting at least either liquid fuel or gas fuel. A plurality of air exhaust parts 47 for exhausting combustion air are provided around the fuel jet part 40, and each of the air exhaust parts 47 has a guide part 58 for controlling the exhaust direction of air, and a diffusion part 59 for diffusing the exhausted air. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a burner and a boiler. More specifically, the present invention relates to a burner and a boiler that can realize reduction of harmful substances using at least one of liquid fuel and gaseous fuel.

  Conventionally, a boiler having a can having a group of water tubes arranged in an annular shape is well known, and in such a boiler, a burner is generally arranged at the center of the water tube group. . That is, in the boiler having such a configuration, the central portion of the annularly arranged water tube group functions as a combustion chamber for burning the fuel supplied from the burner.

  Moreover, in the burner which comprises a boiler, many proposals are made regarding the combustibility improvement technique and the reduction technique of harmful substances (NOx, CO, soot, etc.) (refer patent document 1).

  For example, the burner disclosed in Patent Document 1 is a burner for the purpose of preventing poor combustion due to the bias of the flame, but even if this technique is used, it has a great effect on reducing harmful substances. Can't hope. That is, although various proposals have been made conventionally, there is no known technique that achieves a high level of both combustibility improvement and reduction of harmful substances (NOx, CO, soot, etc.). In particular, the burner that uses liquid fuel is more prominent than the burner that uses gaseous fuel.

  Furthermore, in the boiler configured using the can body having the above-described annularly arranged water tube group, the gas generated in the burner is specified by the position and shape of the gas flow path provided in the can body. Tend to be pulled in the direction (mainly the direction in which the gas flow path is provided). Therefore, depending on the compatibility between the configuration of the burner and the configuration of the can body, there may be a problem in the combustion performance of the burner, the generation of harmful substances in the boiler, and the like.

JP 2005-106310 A

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and is a burner capable of improving combustibility and reducing harmful substances using at least one of liquid fuel and gaseous fuel. It is an issue to provide. Moreover, this invention makes it a subject to provide the boiler which can implement | achieve combustibility improvement and reduction of a harmful substance.

  The present invention has been made in order to solve the above-described problems, and is a burner provided with a fuel ejection portion that ejects at least one of liquid fuel and gaseous fuel, and a combustion is performed around the fuel ejection portion. A plurality of air ejection portions for ejecting the working air are provided, and each of the air ejection portions has a guide portion for controlling the air ejection direction and a diffusion portion for diffusing the ejected air. It is said.

  According to such a configuration, since the air ejection portion has the guide portion, the flow of the flame (gas) is controlled according to the configuration of the can body (position of the gas flow path, etc.), and harmful substances are reduced. (Low dust and low NOx) can be achieved. Further, since the air ejection part has the diffusion part, the fuel and the combustion air can be effectively mixed to reduce dust. According to such a configuration (a configuration having a diffusion portion), the mixing state of the fuel and air ejected from the fuel ejection portion can be made partially non-uniform. In other words, it does not simply improve the mixing state, but partly intentionally forms a non-uniform mixing state by the diffusing section. Therefore, a boiler configured using such a burner reduces the gas temperature in the can. , NOx value can be reduced. Further, according to such a configuration, since the plurality of air ejection portions are provided around the fuel ejection portion, it is possible to form a divided flame and reduce NOx. In addition, according to such a configuration, by having the guide portion, the combustion air can be focused and brought into contact with the fuel at a high speed. Therefore, when liquid fuel is used as the fuel, The combustion state of the flame approaches that of vaporization combustion, and it is possible to reduce NOx. Further, by increasing the flow rate of the air jetted by providing the guide portion, the gas around the guide portion is entrained (because it is in a state of self-recirculation), so it is possible to reduce NOx. it can.

  In addition, the present invention has been made to solve the above-described problem, and has a can body having an inner water tube group and an outer water tube group arranged in an annular shape, and is disposed at a central portion of the inner water tube group. A boiler provided with a burner, wherein the burner is a burner having the above-described configuration.

  According to the boiler according to such a configuration, since the burner that can exhibit the various effects described above is mounted, it is possible to obtain a boiler that can realize reduction of harmful substances.

  Further, in the boiler according to the present invention, the adjacent inner water tubes forming the inner water tube group are closed except for the portion where the gas flow path is provided, and the guide portion is configured so that the gas is evenly distributed in the gas flow path. It is preferable to be configured to flow into

  According to this preferred configuration, since the gas is configured to flow evenly in the gas flow path, the boiler that can stabilize the combustion state in the can and realize more effective reduction of harmful substances Can be obtained.

  Further, in the boiler according to the present invention, the gas flow path is annularly provided at one end side of the inner water tube group, and the guide portion is configured to eject the air inward. It is preferable.

  According to this preferable configuration, since the guide portion is configured to eject the air inward, it is difficult for the flame to spread outward (side where the gas flow path is provided). Therefore, according to such a configuration, the liquid fuel and the flame (gas) in the combustion start stage are less likely to come into contact with the inner water tube group of the can body, thereby eliminating inappropriate incomplete combustion in the immediate vicinity of the burner, Generation of CO and dust can be effectively prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the burner which can implement | achieve combustibility improvement and reduction of a harmful | toxic substance can be obtained using at least one fuel of liquid fuel and gaseous fuel. Moreover, according to this invention, the boiler which can implement | achieve combustibility improvement and reduction of a harmful substance can be obtained.

  Before describing the embodiments of the present invention, terms used in this specification will be described.

  In the present specification, when simply referred to as “gas”, the gas is a concept including at least one of a gas during a combustion reaction and a gas for which the combustion reaction has been completed, and may also be referred to as a combustion gas. In other words, the gas includes both the gas in the combustion reaction and the gas in which the combustion reaction is completed, the gas in the combustion reaction only, or the gas in which the combustion reaction is completed only. It is a concept that includes. Hereinafter, the same concept is used unless otherwise described.

  Further, the exhaust gas means a gas in which the combustion reaction is completed or almost completed. Further, unless otherwise specified, exhaust gas means either or both of the gas that passes through the boiler body and reaches the chimney and the gas that circulates in the body.

  Further, the gas temperature means the temperature of the gas during the combustion reaction unless otherwise specified, and is synonymous with the combustion temperature or the combustion flame temperature. Further, the suppression of the gas temperature means that the maximum value of the gas (combustion flame) temperature is kept low. In general, the combustion reaction is extremely small in the above-mentioned “gas for which the combustion reaction has been completed”, but continues, so “completion of the combustion reaction” means 100% completion of the combustion reaction. It is not a thing.

  Hereinafter, embodiments of the present invention will be described.

  First, a burner according to a first aspect of the present embodiment is a burner provided with a fuel ejection portion that ejects at least one of liquid fuel and gaseous fuel, and combustion air is ejected around the fuel ejection portion. A plurality of air ejection portions are provided, and each air ejection portion has a guide portion for controlling the air ejection direction and a diffusion portion for diffusing the ejected air.

  Moreover, the boiler concerning the 2nd aspect of this embodiment is a boiler provided with the can which has the inner side water pipe group and outer side water pipe group which were arranged cyclically, and the burner arrange | positioned in the center part of the inner side water pipe group. And this burner is the burner concerning a 1st aspect, It is characterized by the above-mentioned.

  Furthermore, the boiler concerning the 3rd aspect of this embodiment is obstruct | occluded between the adjacent inner side water pipes which comprise an inner side water pipe group except the part which provides a gas flow path in the structure of a 2nd aspect, and a guide part is The gas is configured to flow evenly through the gas flow path.

  Further, in the boiler according to the fourth aspect of the present embodiment, in the configuration of the third aspect, the gas flow path is annularly provided at one end side of the inner water tube group, and the guide portion directs air inward. It is configured to erupt.

<First Example>
Hereinafter, the boiler concerning the 1st example of the present invention is explained based on a drawing.

  FIG. 1 shows an explanatory view of a longitudinal section of a boiler according to a first embodiment of the present invention. FIG. 2 shows a simplified explanatory view of a cross section taken along line II-II in FIG. FIG. 3 shows a simplified explanatory view of a cross section taken along line III-III in FIG. FIG. 4 shows a simplified explanatory view of a cross section taken along line IV-IV in FIG.

  As shown in FIG. 1 etc., the boiler 1 concerning a present Example is comprised using the can 10 which has the water pipe group arrange | positioned circularly, and the burner 40 arrange | positioned in the center part of these water pipe groups. A wind box 70 for supplying combustion air to the burner 40 is provided above the burner 40.

  The can body 10 is configured by standing a plurality of water pipe groups (an inner water pipe group 20 and an outer water pipe group 30) between the upper header 11 and the lower header 12. The respective water tube groups 20 and 30 are arranged in a substantially concentric ring shape, and an outer water tube group 30 is provided at a predetermined interval from the inner water tube group 20, and the inner water tube group 20, the outer water tube group 30, and the like. An annular gas flow path 80 is formed between the two.

  In the present embodiment, the inner water tube group 20 is configured using a plurality of inner water tubes 21 and first vertical fin portions 24. Each inner water pipe 21 is formed in an annular shape with a substantially uniform predetermined interval, and a first vertical fin connected between each inner water pipe 21 so as to eliminate a gap between adjacent inner water pipes 21. A portion 24 is provided. That is, in the present embodiment, the inner water tube group 20 is configured in an annular shape in close contact with the first vertical fin portion 24.

  Moreover, the lower end part 21a of each inner side water pipe 21 is a reduced diameter part, and in the inner side water pipe group 20 concerning a present Example, the space around this reduced diameter lower end part 21a is the inner side formed circularly. It will function as the gas channel 25 (corresponding to the “gas channel” of the present invention). That is, the inner gas channel 25 functions to guide the gas generated inside the inner water tube group 20 to the annular gas channel 80.

  In the present embodiment, the outer water tube group 30 is configured using a plurality of outer water tubes 31 and a second vertical fin portion 34. Each outer water pipe 31 is formed in an annular shape with a substantially uniform predetermined interval, and a second vertical fin connected to each other to eliminate a gap between adjacent outer water pipes 31. A portion 34 is provided. That is, in the present embodiment, the outer water pipe group 30 is configured in an annular shape in a close state using the second vertical fin portion 34.

  Moreover, the upper end part 31a of each outer side water pipe 31 is a diameter-reduced part, and in the outer side water pipe group 30 concerning a present Example, the space around this diameter-reduced upper end part 31a is the outer side formed circularly. It functions as the gas flow path 35. The outer gas channel 35 functions to guide the gas introduced into the annular gas channel 80 toward the exhaust cylinder 90. That is, the gas generated inside the inner water tube group 20 is collected in the exhaust pipe 90 via the inner gas flow path 25, the annular gas flow path 80, and the outer gas flow path 35, and the can is It is discharged outside the body 10.

  Each inner water tube 21 constituting the inner water tube group 20 is provided with a plurality of first stud fins 22 (stud fins) at the lower end 21a. The inner water pipe 21 located on the downstream side (downstream side of the gas flow) where the first stud fins 22 are provided has a plurality of flat plate-like first fins 23 (flat plate shape) on the annular gas flow path 80 side. Fins).

  Each outer water pipe 31 constituting the outer water pipe group 30 is provided with a plurality of second stud fins 32 (stud fins) in the vicinity of the inner gas flow path 25. The outer water pipe 31 located on the downstream side (downstream side of the gas flow) where the second stud fins 32 are provided has a plurality of flat plate-like second fins 33 (flat plate shape) on the annular gas flow path 80 side. Fins).

  That is, in the present embodiment, the stud fins (first stud fins 22) are connected to the inner water pipe group 20 (the inner water pipe 21 constituting the inner water pipe group 20) and the outer water pipe group 30 (the outer water pipe 31 constituting the outer water pipe group 30) in the vicinity of the inner gas flow path 25. , Second stud fins 32) are provided, and flat fins (first fins 23, second fins 33) are provided downstream of these stud fins (downstream in the gas flow). In the present embodiment, the first fin 23 and the second fin 33 are provided to have an inclination angle of 80 ° (an inclination angle of 10 ° with respect to the horizontal) with respect to the gas flow (vertical flow). ing.

  5 and 6 are schematic views of a burner provided in the boiler according to the present embodiment. Here, FIG. 5 shows an explanatory view of a longitudinal section of the burner according to the present embodiment, and FIG. 6 shows a bottom view of the burner shown in FIG.

  The burner 40 constituting the boiler 1 according to this embodiment is installed in a partition wall 71 in a wind box 70 as an air supply means for supplying combustion air to the burner 40 (see FIGS. 1 and 5). . Specifically, the mounting plate 41 constituting the burner 40 is mounted on the partition wall 71 from above, and the mounting plate 41 is fastened to the partition wall 71 by fastening means (not shown) such as a bolt, thereby the burner. 40 is installed in the partition wall 71 in the wind box 70. In the present embodiment, the configuration of the blower that supplies air into the wind box 70 is omitted because it is a well-known technique.

  As shown in FIGS. 5 and 6, the burner 40 according to the present embodiment includes a nozzle portion 42 (first nozzle portion 42 a and second nozzle portion 42 b) that sprays liquid fuel (in the “fuel ejection portion” of the present invention). Equivalent), an igniter 43 provided in the vicinity of the first nozzle part 42a, and an air supplied from the wind box 70 to be mixed with the liquid fuel sprayed from the nozzle part 42. Air supply path (first air supply path 44 for supplying primary air, second air supply path 45 for supplying secondary air), and air supplied from the first air supply path 44 is ejected to the combustion chamber 16 side. And a plurality of ambient air ejection portions 47 for ejecting air supplied from the second air supply path 45 to the combustion chamber 16 side (corresponding to the “air ejection portion” of the present invention) (first circumference) Air ejection part 47a to second It is constructed using ambient air ejection section 47f) and.

  As the nozzle part 42 according to the present embodiment, a first nozzle part 42a that sprays liquid fuel at the time of low combustion and high combustion, and a second nozzle part 42b that sprays liquid fuel only at the time of high combustion are provided. . That is, the nozzle part 42 includes a first nozzle part 42a that is in a fuel supply state during low combustion (and a high combustion period) and a second nozzle part 42b that is in a fuel supply state together with the first nozzle part 42a during high combustion. The fuel supply state in each nozzle part 42 is appropriately switched according to the combustion load of the boiler. That is, each nozzle part 42a, 42b is on-off controlled as needed.

  The first air supply path 44 constituting the burner 40 is configured using a first cylinder member 54 provided outside the nozzle portion 42, and the second air supply path 45 uses the first cylinder member 54. Configured. That is, the inner area of the first cylinder member 54 functions as the first air supply path 44, and the area formed between the first cylinder member 54 and the second cylinder member 55 functions as the second air supply path 45. . The upper end portion of the second cylindrical member 55 is formed with an expanding portion 55A that expands outward as it goes upward. The reason why the expanding portion 55 </ b> A having such a shape is provided is to allow the air supplied from the wind box 70 to flow uniformly in the cross-sectional direction in the second air supply path 45. If the expanded portion 55 </ b> A is not provided, the air flow adheres to the inner wall of the second cylindrical member 55 and flows, and does not flow uniformly in the cross-sectional direction in the second air supply path 45.

  A first air supply plate 56 in which a central air ejection portion 46 is perforated is provided at the distal end portion (the end portion on the combustion chamber 16 side of the boiler 1) of the first cylindrical member 54, and is supplied from the wind box 70. Air is ejected to the combustion chamber 16 side through the central air ejection portion 46. Further, a second air supply plate 57 provided with a plurality of ambient air ejection portions 47 is provided at the tip end portion (the end portion on the combustion chamber 16 side of the boiler 1) of the second cylinder member 57. The air supplied from is not only ejected from the central air ejection portion 46 but also through the plurality of ambient air ejection portions 47 to the combustion chamber 16 side.

  The ambient air ejection part 47 (corresponding to the “air ejection part” of the present invention) is provided around the nozzle part 42 as shown in FIGS. 5 and 6. The ambient air ejection portion 47 is configured to eject air inward so that the gas generated by the burner 40 does not spread outward. According to such a configuration, the liquid fuel and the flame (gas) at the combustion start stage are less likely to come into contact with the inner water tube group 20 of the can 10, so that inappropriate imperfect combustion near the burner 40 is eliminated, and CO and The generation of dust can be effectively prevented.

  The ambient air ejection part 47 according to the present embodiment is directed to the inside (nozzle part 42 side) of the air ejected from each ambient air ejection part 47 (first ambient air ejection part 47a to sixth ambient air ejection part 47f). Of the air ejected from the guide portions 58 (first guide portion 58a to sixth guide portion 58f) and the surrounding air ejection portions 47 (first ambient air ejection portion 47a to sixth ambient air ejection portion 47f). It has a diffusion part 59 (first diffusion part 59a to sixth diffusion part 59f) that promotes diffusion.

  More specifically, in the present embodiment, six substantially trapezoidal through-hole portions 51 (first through-hole portion 51a to sixth through-hole portion 51f) are perforated in the second air supply plate 57, A guide part 58 (first guide part 58a to sixth guide part 58f) is configured by using a plate-like member on the outer peripheral side (the side far from the nozzle part 42) of each through-hole part 51. The guide portion 58 is configured to cover a part of each through-hole portion 51. In this embodiment, a portion not covered by the guide portion 58 is ejected from the ambient air ejection portion 47. Functions as a diffusion part 59 (first diffusion part 59a to sixth diffusion part 59f) that promotes diffusion of air.

  Each guide part 58 has at least a part of air ejected from each ambient air ejection part 47 (mainly air in a region covered by the guide part 58 of the through-hole part 51) inside (nozzle part 42 side). The plate-like member is inclined to be ejected in the direction. The inclination angle θ (attachment angle) at this time is preferably about 20 ° to 60 °.

  In addition, the height of each guide portion 58 is set so that the liquid fuel sprayed from the nozzle portion 42 in a cone shape (triangular pyramid shape with the nozzle portion 42 as a vertex) does not contact each guide portion 58. Yes.

  As described above, the diffusing portion 59 (the first diffusing portion 59a to the sixth diffusing portion 59f) is a portion of the through-hole portion 51 that is not covered by the guide portion 58 (indicated by a broken line in FIGS. 5 and 6). Area). Since this part (diffusion part 59) is not provided with an element for rectifying the air supplied via the second air supply path 45 such as the guide part 58 or the like, the part is diffused from the diffusion part 59. The air will expand rapidly.

  Therefore, in the burner 40 according to the present embodiment, the air ejected from the ambient air ejecting portion 47 is guided inward by the guide portion 58 and a part thereof is promoted to diffuse by the diffusing portion 59. .

  The boiler 1 concerning a present Example is comprised as mentioned above, and acts as follows based on the structure. Hereinafter, the operation will be specifically described with reference to FIGS.

  When the burner 40 according to this embodiment is operated in a low combustion state, first, a blower (not shown) is driven, and air is supplied to the first air supply path 44 and the second air supply path 45 via the wind box 70. Is supplied. Next, the igniter 43 is energized in accordance with the timing at which the liquid fuel is sprayed from the first nozzle portion 42a.

  That is, in the present embodiment, air is ejected from the central air ejection part 46 and the ambient air ejection part 47 via the first air supply path 44 and the second air supply path 45, and this air and the first nozzle part 42a. Mixing with the liquid fuel sprayed from is performed. Then, the liquid fuel mixed with the air is ignited by an igniter 43 provided near the first nozzle portion 42a to form an electric spark when energized. By this ignition, the liquid fuel sprayed from the first nozzle part 42a burns, and the low combustion state is maintained as long as the liquid fuel continues to be sprayed from the first nozzle part 42a. Moreover, if liquid fuel is supplied also from the 2nd nozzle part 42b with the 1st nozzle part 42a, the burner 40 will be in a high combustion state.

  In the burner 40 according to the present embodiment, the fuel supply state in the nozzle portion 42 is appropriately switched (on / off control), and can be switched to any one of the stopped state, the low combustion state, and the high combustion state. That is, when the combustion state continues, switching from low combustion to high combustion or from high combustion to low combustion is possible.

  The amount of air supplied to the burner 40 is generally adjusted using a damper (not shown) provided in a duct between the wind box 70 and the blower, an inverter for controlling the rotation speed of the blower, or the like (not shown). The And this air is supplied corresponding to the supply amount of liquid fuel. For example, in a burner configured using two nozzle tips having similar fuel supply performance, the amount of air supplied when liquid fuel is sprayed from one of the nozzle tips (at the time of low combustion) is “1”. Then, the amount of air supplied when spraying liquid fuel from both nozzle tips (during high combustion) is set to “2”. Such air amount adjustment is performed using a damper or an inverter.

  Now, in the burner 40 configured and functioning as described above, as shown in FIG. 5 and the like, a guide portion 58 is provided in order to inject air from the surrounding air ejection portion 47 inward. Therefore, in the burner 40, the flame F (combustion gas) (illustration omitted) will be formed toward the downward direction in the state by which the breadth was suppressed. The combustion gas G0 generated by the burner 40 flows downward along the inner water tube group 20. The gas that has flowed downward along the inner water tube group 20 collides with the lower surface of the can body 10, and then becomes a flow of gas G1 (see FIGS. 1 and 2) that flows radially in the circumferential direction. It is introduced into the annular gas flow path 80 through the inner gas flow path 25.

  The gas G <b> 2 introduced into the annular gas channel 80 via the inner gas channel 25 then flows upward along the inner water tube group 20 and the outer water tube group 30. At this time, the gas G2 flows upward while turning according to the inclination angle of the flat fins (the first fin 23 and the second fin 33) provided in the inner water tube group 20 and the outer water tube group 30. To do. Then, the gas G2 that has flowed upward while swirling collides with the upper surface of the can body 10, and then becomes a flow of gas G3 (see FIGS. 1 and 4) that flows radially in the circumferential direction. The gas is collected in the exhaust cylinder 90 via the gas flow path 35 and discharged to the outside of the can body 10 via the exhaust cylinder 90.

  In the gas flow as described above, the thermal energy of the flame (combustion gas) generated by the burner 40 is recovered by the inner water tube group 20 and the outer water tube group 30.

  More specifically, first, the gases G0 and G1 and the inner surface of the inner water tube group 20 are in contact with each other on the inner surface side of the inner water tube group 20 (the side where the burner 40 is provided (combustion chamber side)). The heat recovery is performed by Next, when the gas G1 passes through the inner gas flow path 25, the inner water pipe group 20 (the lower end portion 21a of the inner water pipe 21) and the first stud fins 22 provided in the vicinity of the inner gas flow path 25, Heat recovery is performed by contact with the gas G1.

  Next, after the gas G1 passes through the inner gas passage 25, the gas collides with the lower end of the outer water tube group 30, and in addition, stud fins 22 and 32 are provided in the vicinity of the inner gas passage 25. Therefore, a turbulent state is promoted in the vicinity of the inner gas flow path 25. Therefore, in the vicinity of the inner gas flow path 25, the first stud fins 22 and the second stud fins 32 are effectively brought into contact with the gas, and highly efficient heat recovery is performed.

  Next, the gas G2 flowing upward while swirling in the annular gas flow path 80 is supplied to the inner water tube group 20, the outer water tube group 30, and the flat fins (first fins) provided in each of the water tube groups 20, 30. 23, the second fin 33) is contacted, and heat recovery from the gas G2 is performed by making these contacts. Finally, the gas G3 that has flowed upward while swirling through the annular gas channel 80 is collected outside the outer tube group 30 (exhaust tube 90 side) until it is collected in the exhaust tube 90 via the outer gas channel 35. ), The heat recovery is performed.

  Since the burner 40 and the boiler 1 according to this embodiment are configured and function as described above, the following effects can be obtained.

  The burner 40 according to the present embodiment is provided with a nozzle portion 42 (corresponding to the “fuel ejection portion” of the present invention) that ejects liquid fuel, and a plurality of nozzles 42 that eject combustion air around the nozzle portion 42. Ambient air ejection portions 47 (corresponding to the “air ejection portion” of the present invention) are provided, and each ambient air ejection portion 47 diffuses the air to be ejected and a guide portion 58 that controls the air ejection direction. And a diffusing portion 59 to be used.

  According to such a structure, since the surrounding air ejection part 47 has the guide part 58, the flow of the flame (gas) is controlled according to the structure of the can body (position of the gas flow path, etc.), and the harmful substances are reduced. (Low dust and low NOx) can be achieved. In the present embodiment, the inner gas flow path 25 of the can body 10 is formed in an annular shape below, and the gas flows uniformly to the inner gas flow path 25 and the gas to the inner water tube group 20 is In order to eliminate early contact, the guide portion 58 is provided at an angle at which combustion air is ejected inward (nozzle portion 42 side). If the combustion air is ejected inward based on such a configuration, the liquid fuel and the flame (gas) at the combustion start stage are less likely to come into contact with the inner water tube group 20 of the can 10. Inappropriate incomplete combustion can be eliminated, and generation of CO and soot can be effectively prevented.

  Moreover, according to such a structure, since the some surrounding air ejection part 47 is provided in the circumference | surroundings of the nozzle part 42, a division | segmentation flame can be formed and reduction in NOx can be achieved.

  Furthermore, according to such a configuration, by having the guide portion 58, it becomes possible to focus the combustion air and bring it into contact with the liquid fuel at a high speed, so that the combustion state of the flame approaches vaporization combustion, Low NOx can be achieved. Further, by increasing the flow velocity of the combustion air jetted by providing the guide portion 58 in this way, the gas around the guide portion 58 is entrained (because it is in a state of self-recirculation), so the NOx is reduced. Can be achieved.

  Moreover, the surrounding air ejection part 47 which comprises the burner 40 concerning a present Example also has the spreading | diffusion part 59 with the guide part 58 which exhibits the various effect mentioned above. As described above, the diffusion portion 59 is a portion of the through-hole portion 51 that is not covered with the guide portion 58 (see FIGS. 5 and 6). That is, since the diffusion part 59 is not provided with an element for rectifying the air, such as the guide part 58, the air ejected from the diffusion part 59 flows into the edge part (through-hole part) of the diffusion part 59. 51 (edge portion)). Then, in the immediate vicinity of the burner 40, a small turbulence occurs in the air, and the mixing state of the liquid fuel sprayed from the nozzle part 42 and the air can be partially made uneven. Since the burner 40 according to the present embodiment has such a diffusing portion 59, the mixing state is not simply improved, and a partly intentionally non-uniform mixing state can be formed. That is, in the present embodiment, by providing the diffusing portion 59, it is possible to form a light and dark combustion state in the vicinity of the burner 40, so that the gas temperature can be lowered and the NOx value can be reduced. Of course, according to such a configuration, since the ambient air ejection part 47 has the diffusion part 59, the liquid fuel and the combustion air can be effectively mixed to reduce dust.

  As described above, the boiler 1 according to this embodiment is based on the reduction of CO and dust by suppressing the spread of gas in the combustion chamber 16 of the can body 10 and the appropriate exhaust gas circulation flow formed in the can body 10. NOx reduction, CO reduction, and soot dust by the synergistic effect of the gas temperature reduction, the gas temperature reduction due to the formation of an appropriate split flame, and the gas temperature reduction due to the light and shade combustion formed by the diffusion part 39 Can be reduced.

  In addition, according to the present embodiment, the boiler 1 is configured as described above, and the gas flows in the can 10 as described above. Therefore, heat recovery is effectively performed and an extended transmission with high durability. A boiler having a water tube group having a hot surface (such as fins) can be obtained.

  Specifically, according to the boiler 1 according to the present embodiment, the stud fins 22 and 32 (enlarged heat transfer surfaces) are provided in the vicinity of the inner gas channel 25 (gas channel), which is a region where the temperature difference is large. Therefore, heat recovery can be performed effectively. In addition, since the enlarged heat transfer surfaces provided in the vicinity of the inner gas flow path 25 are the stud fins 22 and 32, even if an overheated state occurs, cracks, dropouts, and the like are unlikely to occur. Further, according to such a configuration, the stud fins 22 and 32 are provided in the vicinity of the inner gas flow path 25, and heat recovery is performed from the combustion gas at an early stage, and the temperature of the combustion gas is lowered early. Can be reduced.

  Further, in the boiler 1 according to the present embodiment, flat fins 23 and 33 inclined with respect to the gas flow are provided on the downstream side of the stud fins 22 and 32 provided in the vicinity of the inner gas flow path 25. It has been. According to such a configuration, it becomes possible to configure the boiler 1 that can be recovered more effectively and operated with high efficiency without wasting the heat energy that could not be recovered by the stud fins 22 and 32. .

  Furthermore, in the boiler 1 according to the present embodiment, the plate-like fins 23 and 33 provided on the downstream side of the stud fins 22 and 32 are provided so as to be inclined at a predetermined angle with respect to the gas flow. Ascending while rotating in the annular gas flow path 80. That is, according to the present embodiment, compared to the case where fins are provided at right angles to the gas flow, the fins 23 and 33 do not obstruct the gas flow, so that the boiler 1 capable of realizing a low pressure loss can be obtained. .

  Moreover, according to the boiler 1 concerning a present Example, since it becomes possible to implement heat recovery effectively as mentioned above, it becomes possible to achieve size reduction of a boiler resulting from this. . That is, by increasing the heat recovery rate, it is possible to increase the operating efficiency of the boiler, and accordingly, the boiler can be reduced in size.

<Other examples>
The present invention is not limited to the above-described embodiments and examples (hereinafter referred to as “the above-described embodiments and the like”), and various modifications are made as necessary within the scope that can meet the gist of the present invention. These are all included in the technical scope of the present invention.

  In the above-described embodiments and the like, the case where the guide portions 57 provided in the respective ambient air ejection portions 47 are provided in the same direction and inclined at the same angle (inward direction) has been described. It is not limited to the configuration. Therefore, for example, you may comprise so that the installation inclination angle of each guide part 57 may differ suitably.

  In the above-described embodiments, etc., the case has been described in which the guide portion 57 is configured using a plate-shaped member (scoop type) having a U-shaped cross section, but the present invention is not limited to this configuration, Any configuration may be employed as long as at least a part of the air ejected from the air ejection portion 47 can be guided inward. Therefore, you may comprise a guide part using the flat plate-shaped member of 1 sheet, for example. Specifically, a flat plate-like member may be provided on the outer peripheral portion of the through-hole portion 51 constituting each of the surrounding air ejection portions 47 so as to be inclined. Even with such a configuration, it is possible to guide at least part of the air ejected from the ambient air ejecting portion 47 in the inner direction, and thus the various effects described above can be obtained.

  Furthermore, in the above-described embodiment, the second nozzle 42b for high combustion is disposed on the central axis of the first cylindrical member 54, and the first nozzle 42a for low combustion (and high combustion) is disposed from the central axis. Although the arrangement is shifted, the present invention is not limited to this arrangement. For example, it is also possible to arrange so that the center between the second nozzle 42 b and the first nozzle 42 a overlaps the central axis of the first cylinder member 54. The present invention can also be applied to a burner that switches between a low combustion amount and a high combustion amount by a single nozzle (not shown).

  Moreover, in the said embodiment etc., although the case where the guide part 57 was provided in all the surrounding air ejection parts 47 was demonstrated, this invention is not limited to this structure. The present invention aims to control the flow of air (combustion air) so that the gas generated by the burner 40 does not spread outside more than necessary. In addition to the configuration in which the guide portion is provided, the concept includes a configuration in which the guide portion is provided in part of the ambient air ejection portion.

  Furthermore, in the above-described embodiments and the like, the type of liquid fuel was not particularly described, but the present invention is not limited to any liquid fuel, and liquid fuels such as kerosene, A heavy oil, B heavy oil, and C heavy oil are used. Applicable. Moreover, in the said embodiment etc., although the case where liquid fuel was used as a fuel was demonstrated, this invention is not limited to this structure, You may use gaseous fuel as needed. Furthermore, for example, a two-component mixed fluid (for example, a fluid obtained by mixing liquid fuel and water) may be used as the fuel.

  Moreover, the boiler 1 concerning this invention is not limited to the structure of the can 10 demonstrated in FIG. 1 etc., A various change is possible as needed. Therefore, for example, a configuration as shown in FIG. Here, FIG. 7 shows a simplified explanatory view of a transverse section of a boiler according to another embodiment of the present invention.

  A boiler according to another embodiment has the same basic configuration as that of the first embodiment described above. Therefore, in the following, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the detailed description thereof is omitted, and the configuration different from the first embodiment will be mainly described. .

  FIG. 7 shows a simplified explanatory view of a cross section of a boiler according to another embodiment of the present invention. More specifically, it is a simplified explanatory diagram corresponding to FIG. 2 according to the first embodiment described above. That is, FIG. 7 shows a simplified explanatory view of a cross section in the vicinity of the inner gas flow path 25 (corresponding to the “gas flow path” of the present invention) of the boiler according to the present embodiment.

  As described above, the boiler 1 according to the present embodiment basically has the same configuration as that of the first embodiment, and the difference from the first embodiment is that the inner gas flow path 25 is in the vicinity. The number of stud fins 22 and 32 provided. In this embodiment, compared with the first embodiment, the first stud fins 22 provided at the lower end 21a of the inner water pipe 21 are reduced, and the second stud fins 32 provided at the lower end of the outer water pipe 31 are provided. Many are provided. More specifically, the first stud fin 22 is not provided on the annular gas flow path 80 side at the lower end 21 of the inner water pipe 21, and the corresponding amount of the stud fin (reduced by the inner water pipe 21) is provided on the outer water pipe 31. It is provided at the lower end.

  As described in the first embodiment, after the gas G <b> 1 passes through the inner gas passage 25, the gas collides with the lower end portion of the outer water tube group 30. After that, in the vicinity of the inner gas flow path 25, the gas mainly flows upward along the outer water tube group 30. As a result, in the vicinity of the inner gas flow path 25, the outer water tube group 30 has more contact times with the gas than the inner water tube group 20.

  A present Example is comprised paying attention to this gas flow, and aims at providing the boiler 1 which can perform heat recovery with higher efficiency.

  As described above, the boiler according to the present embodiment is provided with the stud fins 22 and 32 in the inner water tube group 20 and the outer water tube group 30 in the vicinity of the inner gas flow path 25, and the outer water tube group 30 is arranged on the inner side. It is characterized by having a structure in which more stud fins are provided than in the water tube group 20.

  According to the boiler 1 according to the present embodiment, after the combustion gas generated in the burner 40 provided in the central portion of the inner water tube group 20 contacts the outer water tube group 30 via the inner gas passage 25, It circulates between water pipe groups (between the inner water pipe group 20 and the outer water pipe group 30) (annular gas flow path 80). At this time, the gas continuously flows from the inner water tube group 20 toward the outer water tube group 30, so in the annular gas flow path 80, the gas contact time is inevitably higher in the outer water tube group 30 than in the inner water tube group 20. Will be longer. According to the present embodiment, the outer water tube group 30 is provided with more stud fins than the inner water tube group 20, and therefore heat recovery from the combustion gas can be performed more effectively.

  Moreover, according to the boiler 1 concerning this other Example, in addition to the said effect, the effect obtained in a 1st Example can also be naturally obtained.

  Further, in the above-described embodiment and the like, the case where the stud fins 22 and 32 are provided in both the inner water tube group 20 and the outer water tube group 30 in the vicinity of the inner gas channel 25 (gas channel) has been described. It is not limited to the configuration. Therefore, for example, it is good also as a structure which provides a stud fin only in the outer side water pipe group 30 in the inner side gas flow path 25 vicinity. As described above, since the gas continuously flows from the inner water tube group 20 toward the outer water tube group 30, the gas contact time in the annular gas flow path 80 is longer than that of the inner water tube group 20. Will be longer. Therefore, even when the stud fin is provided only in the outer water tube group 30 in the vicinity of the inner gas flow path 25 in this way, heat recovery from the combustion gas can be performed relatively effectively.

  Moreover, in the said embodiment etc., although the structure which provides the cyclic | annular inner side gas flow path 25 (gas flow path) in the lower end side of the inner side water pipe group was demonstrated, this invention is not limited to this structure. Therefore, for example, an annular inner gas channel (corresponding to the “gas channel” of the present invention) may be provided on the upper end side of the inner water tube group. At this time, when the inner gas channel is provided on the upper end side of the inner water tube group, the outer gas channel is arranged on the outer side in order to increase the heat recovery rate (in order to increase the contact time between the gas and the water tube group). It is preferable to provide at the lower end side of the water tube group.

  Furthermore, in the above-described embodiment and the like, the case where a boiler is configured using a can body in which two rows of water pipe groups are arranged substantially concentrically has been described, but the present invention is not limited to this configuration, and as necessary. In addition, the can body may be configured by arranging three or more groups of water tubes. If a can body is configured by arranging three rows of water tube groups (for example, an inner water tube group, an intermediate water tube group, and an outer water tube group) in a substantially concentric circle, one end side (for example, the lower end side) of the inner water tube group If the inner gas flow path is provided in the intermediate water pipe group, the intermediate gas flow path is provided on the other end side (for example, the upper end side), and the outer gas flow is provided on one end side (for example, the lower end side) of the outer water pipe group. It is preferable to do.

  Moreover, in the said embodiment etc., although the case where the cylindrical stud fins 22 and 32 were used was demonstrated, this invention is not limited to this structure, The durable protrusion which can be welded appropriately to a water pipe Any shape may be used as long as it is a thing. Therefore, for example, an oblique cylinder shape, an elliptic cylinder shape (including an oblique elliptic cylinder shape), a prismatic shape (including an oblique prism shape), a cone shape (including an oblique cone shape), a pyramid shape (including an oblique pyramid shape), etc. Stud fins having the following shape may be used.

It is explanatory drawing of the longitudinal cross-section of the boiler concerning the 1st Example of this invention. FIG. 2 is a simplified explanatory diagram of a cross section taken along line II-II in FIG. 1. FIG. 3 is a simplified explanatory diagram of a cross section taken along line III-III in FIG. 1. FIG. 4 is a simplified explanatory diagram of a cross section taken along line IV-IV in FIG. 1. The explanatory drawing of the longitudinal section of the burner concerning the 1st example of the present invention is shown. FIG. 6 is a bottom view of the burner shown in FIG. 5. It is a simplified explanatory drawing of the cross section of the boiler concerning the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Boiler 10 ... Can body 11 ... Upper header 12 ... Lower header 16 ... Combustion chamber 20 ... Inner water pipe group 21 ... Inner water pipe 21a ... Lower end part 22 ... First stud fin 23 ... First fin (flat fin)
24 ... First vertical fin part 25 ... Inner gas flow path 30 ... Outer water pipe group 31 ... Outer water pipe 31a ... Upper end part 32 ... Second stud fin 33 ... Second fin (flat fin)
34 ... Second vertical fin part 35 ... Outer gas flow path 40 ... Burner 41 ... Mounting plate 42 ... Nozzle part 42a ... First nozzle part 42b ... Second nozzle part 43 ... Igniter 44 ... First air supply path 45 ... 2nd air supply path 46 ... Central air ejection part 47 ... Ambient air ejection part 47a-47f ... 1st ambient air ejection part-6th ambient air ejection part 51 ... Through-hole part 51a-51f ... 1st through-hole part-1st Six through-hole portions 54 ... first cylinder member 55 ... second cylinder member 55A ... expanded portion 56 ... first air supply plate 57 ... second air supply plate 58 ... guide portions 58a to 58f ... first guide portion to sixth Guide part 59 ... Diffusion part 59a-59f ... 1st diffusion part-6th diffusion part 70 ... Wind box 71 ... Partition 80 ... Annular gas flow path 90 ... Exhaust pipe

Claims (4)

A burner provided with a fuel ejection portion that ejects at least one of liquid fuel and gaseous fuel,
A plurality of air ejection portions for ejecting combustion air are provided around the fuel ejection portion,
Each of the air ejection parts has a guide part for controlling the air ejection direction and a diffusion part for diffusing the ejected air. A boiler comprising a can having an inner water tube group and an outer water tube group arranged in an annular shape, and a burner disposed in the center of the inner water tube group,
The boiler according to claim 1, wherein the burner is the burner according to claim 1. Between the adjacent inner water pipes forming the inner water pipe group is closed except for the part where the gas flow path is provided,
The boiler according to claim 2, wherein the guide portion is configured so that gas flows through the gas flow path evenly. The gas flow path is annularly provided on one end side of the inner water tube group,
The boiler according to claim 3, wherein the guide portion is configured to eject the air inward.

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