WO2016157925A1 - Boiler device - Google Patents

Boiler device Download PDF

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Publication number
WO2016157925A1
WO2016157925A1 PCT/JP2016/050484 JP2016050484W WO2016157925A1 WO 2016157925 A1 WO2016157925 A1 WO 2016157925A1 JP 2016050484 W JP2016050484 W JP 2016050484W WO 2016157925 A1 WO2016157925 A1 WO 2016157925A1
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WO
WIPO (PCT)
Prior art keywords
exhaust gas
boiler
line
fuel
fuel gas
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PCT/JP2016/050484
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French (fr)
Japanese (ja)
Inventor
亮 宮川
Original Assignee
三浦工業株式会社
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Publication date
Application filed by 三浦工業株式会社 filed Critical 三浦工業株式会社
Priority to KR1020177007385A priority Critical patent/KR20170134957A/en
Priority to JP2017509309A priority patent/JPWO2016157925A1/en
Publication of WO2016157925A1 publication Critical patent/WO2016157925A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N1/00—Regulating fuel supply
    • F23N1/007—Regulating fuel supply using mechanical means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C9/00—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber
    • F23C9/08—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber for reducing temperature in combustion chamber, e.g. for protecting walls of combustion chamber
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N1/00—Regulating fuel supply
    • F23N1/02—Regulating fuel supply conjointly with air supply

Definitions

  • the present invention relates to a boiler device that performs exhaust gas circulation.
  • This application claims priority based on Japanese Patent Application No. 2015-071633 for which it applied to Japan on March 31, 2015, and uses the content here.
  • Patent Document 1 discloses such a boiler apparatus.
  • Patent Document 1 discloses a configuration that prevents ignition failure caused by excess air by suppressing the amount of combustion air supplied during ignition when exhaust gas is not circulated.
  • a boiler device that circulates exhaust gas performs combustion adjustment based on the normal combustion state in which the exhaust gas is circulated. Therefore, oxygen is not mixed in an exhaust gas having a lower oxygen concentration than the combustion air. The concentration will be higher than expected.
  • the exhaust gas ratio is adjusted to be high during normal combustion, the difference in the amount of oxygen contained in the combustion air becomes large between ignition when the exhaust gas is not circulated and normal combustion.
  • Patent Document 1 although the opening degree of the damper is controlled to prevent harmful effects caused by excess oxygen at the time of ignition, it is necessary to add damper control at the time of ignition.
  • An object of the present invention is to provide a configuration capable of reliably preventing excessive oxygen concentration during ignition and realizing stable ignition in a boiler device that performs exhaust gas circulation.
  • the present invention includes a boiler, a fuel supply line for supplying fuel gas to the boiler, an air supply line for supplying combustion air mixed with the fuel gas to the boiler, and a blower connected to the air supply line.
  • An air supply unit a burner which is disposed inside the boiler and combusts an air-fuel mixture of the fuel gas and the combustion air, an exhaust line which exhausts exhaust gas generated by the combustion of the air-fuel mixture, and the exhaust
  • An exhaust gas circulation line that connects the line and the air supply unit, and circulates part of the exhaust gas to the air supply unit, and an end on one side and an end on the other side are connected on the path of the fuel supply line.
  • bypass line The bypass line, the bypass valve disposed in the bypass line, and close the bypass valve during normal combustion, and open the bypass valve when the burner ignites.
  • serial bypass line circulating the fuel gas, and a control unit in comparison with a normal combustion control is performed to increase the supply amount of the fuel gas to a boiler apparatus, characterized in that it comprises a.
  • the boiler device further includes a fuel gas decompression member that is disposed in the fuel supply line and decompresses the fuel gas, and the bypass line has one end connected to the upstream side of the fuel gas decompression member, The other end is preferably connected to the downstream side of the fuel gas decompression member.
  • the boiler device further includes an exhaust gas flow rate adjusting unit that is disposed in the exhaust gas circulation line and adjusts the flow rate of the exhaust gas, and the control unit does not supply the exhaust gas to the air supply unit when the burner is ignited. It is preferable to adjust the exhaust gas flow rate adjusting unit so that the exhaust gas flow rate adjusting unit is adjusted so that supply of the exhaust gas to the air supply unit is started after a predetermined time has elapsed since the ignition of the burner.
  • FIG. 4 is a timing chart schematically showing opening / closing control of a bypass valve and an exhaust gas flow rate adjustment damper before and after ignition.
  • the boiler apparatus 1 of this embodiment is a steam boiler that generates steam by heating water, and supplies steam to a load device (not shown).
  • the “line” in the present specification is a general term for lines capable of flowing a fluid such as a flow path, a path, and a pipeline.
  • the boiler apparatus 1 of this embodiment is the boiler 2, the fuel supply part 3, the air supply part 4, the exhaust gas circulation line 19, the steam line 20, the water supply part 5, and the control apparatus. 6.
  • the boiler 2 includes a boiler casing 11, a plurality of water pipes 12 disposed inside the boiler casing 11, an air supply duct 17 in which combustion air is mixed with fuel gas, and a mixture of fuel gas and combustion air.
  • a burner 15 that burns air and an exhaust cylinder 18 as an exhaust line that exhausts exhaust gas to the outside of the boiler casing 11 are provided.
  • the boiler casing 11 is formed in a rectangular parallelepiped shape in plan view.
  • the plurality of water tubes 12 are arranged inside the boiler housing 11 with a predetermined interval in the longitudinal direction and the width direction.
  • the plurality of water pipes 12 are held inside the boiler casing 11 with their upper ends connected to an upper header (not shown) and their lower ends connected to a lower header (not shown).
  • casing 11 is not limited to what is formed in the above-mentioned rectangular parallelepiped shape.
  • a boiler housing formed in a round shape can be used.
  • the air supply duct 17 is connected to one end side of the boiler casing 11 in the longitudinal direction. Fuel gas is supplied from the fuel supply unit 3 to the air supply duct 17 and combustion air is supplied from the air supply unit 4.
  • the burner 15 is disposed in a portion (air supply port) to which the air supply duct 17 is connected in the boiler casing 11, burns a mixture of fuel gas and combustion air, and superheats water in the plurality of water pipes 12. Generate steam.
  • the exhaust cylinder 18 is a discharge line for discharging exhaust gas generated by combustion to the outside of the boiler casing 11, and is connected to the other end side in the longitudinal direction of the boiler casing 11.
  • the fuel supply unit 3 is configured to supply fuel to the boiler 2.
  • the fuel supply unit 3 includes a fuel supply line 31, a governor 32, an on-off valve 33, a first orifice 34, a second orifice 35, a bypass line 36, and a bypass valve 37.
  • the fuel supply line 31 has an upstream end connected to a fuel supply source (not shown) and a downstream end connected to the air supply duct 17.
  • the governor 32 is a pressure adjusting unit that adjusts the pressure of the fuel gas flowing through the fuel supply line 31.
  • the governor 32 of the present embodiment receives the pressure of the air supply line 42 by a communication pipe (not shown) connected to the air supply line 42, and the fuel gas is supplied to the supply amount of combustion air by a so-called equalizing valve system. It has a function as a proportional control valve for controlling the flow rate of the fuel gas so that the supply amount of fuel is proportional.
  • the on-off valve 33 is disposed on the downstream side of the governor 32.
  • the on-off valve 33 can open or close the flow path of the fuel supply line 31.
  • the first orifice 34 is disposed on the downstream side of the on-off valve 33 and decompresses the fuel gas.
  • the second orifice 35 is a fuel gas decompression member that decompresses the fuel gas, and is disposed on the downstream side of the first orifice 34.
  • the bypass line 36 is connected to the upstream side of the second orifice 35 and to the downstream side.
  • the bypass valve 37 is disposed in the bypass line 36.
  • the bypass valve 37 is an electromagnetic valve that opens or closes the flow path of the bypass line 36.
  • combustion adjustment at the time of normal combustion is performed based on the state where the bypass valve 37 is closed and the flow path of the bypass line 36 is closed.
  • the normal combustion here means a combustion state after ignition (for example, a state in which steam generated by the boiler 2 is supplied to the load device).
  • the air supply unit 4 is configured to supply combustion air to the boiler 2.
  • the air supply unit 4 of this embodiment includes a blower 41, an air supply line 42, and a combustion air damper 43.
  • the blower 41 includes a fan, a motor that rotates the fan, and an inverter.
  • the blower 41 can adjust the rotation speed of the motor according to the frequency input to the inverter.
  • An exhaust gas circulation line 19 to be described later is connected to the blower 41 so that a part of the exhaust gas discharged from the boiler casing 11 to the outside can be introduced into the blower 41.
  • the air supply line 42 has an upstream end connected to the blower 41 and a downstream end connected to the air supply duct 17.
  • the blower 41 takes in air by rotation of the fan, and sends combustion air to the boiler 2 through the air supply line 42.
  • the combustion air damper 43 is connected to the air supply line 42 so as to be rotatable between a closed state in which the combustion air flow path is closed and an open state in which the combustion air flow path is opened and the combustion air flow path is opened. Be placed. Further, the combustion air damper 43 is configured to be able to change the opening degree in order to adjust the supply amount of the combustion air.
  • the exhaust gas circulation line 19 has an upstream end connected to the exhaust pipe 18 and a downstream end connected to the blower 41 (air supply unit 4). A part of the exhaust gas discharged from the inside of the boiler housing 11 to the exhaust pipe 18 is sent to the blower 41 by the exhaust gas circulation line 19, mixed with outside air, and sent again to the boiler 2.
  • an exhaust gas flow adjustment damper 27 is arranged in the exhaust gas circulation line 19, an exhaust gas flow adjustment damper 27 is arranged.
  • the exhaust gas flow rate adjustment damper 27 is a so-called multi-position damper whose opening degree can be adjusted.
  • the exhaust gas flow rate adjusting damper 27 of the present embodiment closes the exhaust gas flow path inside the exhaust gas circulation line 19 and rotates a predetermined angle (for example, 90 degrees) from this closed state, thereby changing the exhaust gas flow path. It can be rotated between the open state and the open state.
  • the exhaust gas flow rate adjustment damper 27 is a multi-position damper as described above, and the opening degree in the open state can be adjusted. With this function, the mixing ratio of the exhaust gas sent to the blower 41 can be adjusted.
  • the exhaust gas flow rate adjustment damper 27 functions as an exhaust gas flow rate adjustment unit that can adjust whether or not to supply exhaust gas to the blower 41, including the adjustment of the flow rate, by being configured so that the opening degree can be adjusted.
  • the exhaust gas flow path inside the exhaust gas circulation line 19 is opened, and the normal combustion adjustment is performed based on the state where a part of the exhaust gas is introduced into the blower 41. .
  • the steam line 20 has an upstream end connected to the boiler 2 and a downstream end connected to a load device (not shown). Steam generated in the boiler 2 is supplied to the load device via the steam line 20.
  • the water supply unit 5 is configured to supply water for generating steam to the boiler 2.
  • the water supply unit 5 of the present embodiment includes a water supply line 51 and a heat exchanger 52.
  • the water supply line 51 has an upstream end connected to a water supply source (not shown) and a downstream end connected to the boiler 2.
  • the heat exchanger 52 is disposed inside the exhaust pipe 18. The heat exchanger 52 performs heat exchange between the water flowing inside the water supply line 51 and the exhaust gas flowing through the exhaust pipe 18. Thereby, the water flowing through the water supply line 51 is supplied to the boiler 2 in a preheated state.
  • the control device 6 is electrically connected to the blower 41, the combustion air damper 43, the bypass valve 37, each pressure sensor, and the like.
  • the control device 6 of this embodiment includes a control unit 61 and a storage unit 62.
  • the controller 61 performs various controls such as adjustment of the supply amounts of fuel gas and combustion air, ignition control of the boiler 2, and combustion control.
  • the storage unit 62 stores various types of information for the control unit 61 to perform control.
  • the control unit 61 of the present embodiment performs control to increase the flow rate of the fuel gas at the time of ignition than at the time of normal combustion control in order to prevent ignition failure due to the exhaust gas not being circulated at the time of ignition. Do. Next, fuel gas supply control and exhaust gas circulation control during ignition by the control unit 61 will be described.
  • FIG. 2 is a timing chart schematically showing opening / closing control of the bypass valve 37 and the exhaust gas flow rate adjustment damper 27 before and after ignition.
  • pre-purge control is performed as a stage before ignition.
  • the pre-purge control is control in which air is sent to the boiler casing 11 by the blower 41 and the inside of the boiler casing 11 is ventilated.
  • the bypass valve 37 is controlled to be closed, and the exhaust gas flow rate adjustment damper 27 disposed in the exhaust gas circulation line 19 is also controlled to be closed.
  • the control shifts to ignition control.
  • the control unit 61 performs control to open the flow path of the bypass line 36 by opening the bypass valve 37.
  • the fuel gas flowing through the bypass line 36 is sent to the downstream side of the fuel supply line 31 without being depressurized by the second orifice 35. Therefore, the amount of fuel gas supplied during ignition is higher than when the bypass line 36 is closed and all the fuel gas supplied to the boiler 2 is decompressed by the second orifice 35 (during normal combustion). Becomes larger.
  • the control unit 61 controls the bypass valve 37 to be closed and the exhaust gas flow rate adjustment damper 27 to be opened (see FIG. 2) after a predetermined time (several seconds to several tens of seconds) has elapsed since the start of ignition.
  • a predetermined time severe seconds to several tens of seconds
  • By closing the bypass valve 37 the flow path of the bypass line 36 is closed, and the supply amount of the fuel gas supplied to the boiler 2 becomes smaller than that at the time of ignition. Also.
  • the exhaust gas flow rate adjustment damper 27 By opening the exhaust gas flow rate adjustment damper 27, the flow path of the exhaust gas circulation line 19 is opened, and the exhaust gas generated after ignition is introduced into the blower 41 (air supply unit 4).
  • combustion adjustment is performed based on the state where the flow path of the bypass line 36 is closed and the exhaust gas is introduced into the blower 41 (the state where the exhaust gas having a low oxygen concentration and the outside air are mixed). Therefore, the fuel gas is supplied to the boiler 2 in an appropriate amount when the bypass valve 37 is closed, and the exhaust gas is mixed in the appropriate amount with respect to the combustion air by opening the exhaust gas flow adjustment damper 27. It is supplied to the boiler 2.
  • the boiler 2 that has shifted to the combustion control heats the water in the water pipe 12 by the combustion of a mixture of combustion air mixed with exhaust gas and fuel gas to generate steam.
  • the generated steam is supplied to the load equipment through the steam line 20.
  • the exhaust gas generated by the combustion of the air-fuel mixture is sent to the exhaust cylinder 18.
  • a part of the exhaust gas is sent to the blower 41 through the exhaust gas circulation line 19 and the rest is discharged to the outside.
  • the exhaust gas sent to the blower 41 is mixed with external air and circulated to the boiler 2 through the air supply line 42.
  • the boiler apparatus 1 of the present embodiment includes a bypass line 36 in which an end on one side and an end on the other side are connected on the path of the fuel supply line 31, a bypass valve 37 disposed in the bypass line 36, When the burner 15 is ignited, the bypass valve 37 is closed. When the burner 15 is ignited, the bypass valve 37 is opened and the fuel gas is also circulated through the bypass line 36. And a control unit 61 that performs control. As a result, the amount of fuel gas supplied at the time of ignition is larger than that at the time of normal combustion. Therefore, since the exhaust gas with a low oxygen concentration is not mixed, the oxygen concentration is excessive with respect to the fuel gas. Defects can be reliably prevented.
  • the bypass line 36 has one end connected to the upstream side of the second orifice 35 and the other end connected to the downstream side of the second orifice 35.
  • the control unit 61 closes the exhaust gas flow rate adjustment damper 27 so that the exhaust gas is not supplied to the blower 41 (air supply unit 4), and the exhaust gas is supplied to the blower 41 after a predetermined time has elapsed from the ignition of the burner. Control is performed to open the exhaust gas flow rate adjustment damper 27 so as to be started. As a result, it is possible to reliably prevent the air (residual exhaust gas) inside the exhaust gas circulation line 19 from being supplied to the blower 41 at the start of pre-purge or ignition, and smoothly shift to control for circulating the exhaust gas as the exhaust gas is generated. Can be made.
  • the control for closing the bypass valve 37 and the control for opening the exhaust gas flow rate adjustment damper 27 are performed at the same time, but these controls are performed at different timings with a time difference. It may be.
  • the bypass valve 37 is configured as an electromagnetic valve that is electrically controlled, but may be appropriately changed according to circumstances. For example, a configuration such as a needle valve or a butterfly valve may be added to the bypass valve 37 so that the flow rate of the fuel gas flowing through the bypass line 36 can be adjusted.
  • the exhaust gas flow rate adjusting damper 27 constitutes the exhaust gas flow rate adjusting unit, but this configuration can be changed as appropriate.
  • an electromagnetic valve can be employed in the exhaust gas flow rate adjustment unit.
  • downstream end of the exhaust gas circulation line 19 is connected to the blower 41, but this configuration can be changed as appropriate.
  • the downstream end of the exhaust gas circulation line 19 may be connected to the air supply line 42 and the exhaust gas may be sent to the air supply line 42 by a separately provided fan.
  • the exhaust gas flow rate adjusting portion 27 is configured by the exhaust gas flow rate adjusting damper 27 arranged in the exhaust gas circulation line 19, but the configuration is not limited to this.
  • the exhaust gas flow rate adjustment unit can be configured by a flow rate adjustment damper and an open / close damper.
  • the flow rate adjustment damper is configured to be able to adjust the opening degree, and is a damper that adjusts the mixing ratio of the exhaust gas.
  • the open / close damper is a damper that adjusts whether exhaust gas is supplied to the blower 41.
  • the exhaust gas flow rate adjustment unit can be configured with only the open / close damper. Thus, the configuration of the exhaust gas flow rate adjusting unit can be changed as appropriate.

Abstract

A boiler device 1 is provided with a bypass line (36) of which a one-side end and an other-side end are connected to the path of a fuel supply line (31), a bypass valve (37) arranged in the bypass line (36), and a control unit (61) which performs control for closing the bypass valve (37) during normal combustion and opening the bypass valve (37) to allow fuel gas to flow through the bypass line (36) as well during ignition of a burner (15), thereby making the amount of fuel gas supplied greater than the amount during normal combustion. The bypass line (36) is connected at the one-side end to the upstream side of a second orifice (35), and is connected at the other-side end to the downstream side of the second orifice (35).

Description

ボイラ装置Boiler equipment
　本発明は、排ガス循環を行うボイラ装置に関する。本願は、２０１５年３月３１日に日本に出願された特願２０１５－０７１６３３号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a boiler device that performs exhaust gas circulation. This application claims priority based on Japanese Patent Application No. 2015-071633 for which it applied to Japan on March 31, 2015, and uses the content here.
　従来から、燃焼によって生じた排ガスをボイラに循環させる排ガス循環を行うボイラ装置が知られている。この種のボイラ装置を開示するものとして例えば特許文献１がある。特許文献１には、排ガスの循環が行われていない着火時において、燃焼用空気の供給量を抑えることによって過剰空気による着火の不具合等を防止する構成が開示されている。 2. Description of the Related Art Conventionally, boiler apparatuses that perform exhaust gas circulation that circulates exhaust gas generated by combustion in a boiler are known. For example, Patent Document 1 discloses such a boiler apparatus. Patent Document 1 discloses a configuration that prevents ignition failure caused by excess air by suppressing the amount of combustion air supplied during ignition when exhaust gas is not circulated.
特開平６－２８８５１１号公報JP-A-6-288511
　排ガス循環を行うボイラ装置は、排ガスが循環している通常の燃焼時の状態に基づいて燃焼調整を行っているため、燃焼用空気に比べて酸素濃度が低い排ガスが混合されていない状態では酸素濃度が想定されているよりも高い状態になってしまう。特に、通常の燃焼時において排ガス比率が高く調整されている場合は、排ガスが循環していない着火時と通常の燃焼時とで燃焼用空気に含まれる酸素量の差が大きくなってしまう。この点、特許文献１では、ダンパの開度を制御して着火時における過剰酸素による弊害を防止しているものの、着火時のダンパ制御を追加する必要がある。また、燃焼空気の供給量に燃料ガスの供給量が比例する比例制御が行われるボイラ装置では、通常の燃焼時と状況が異なる着火時にあわせて空気比の調整を行うことが難しかった。このように、従来の技術には、着火の不具合を確実に防止するという点で改善の余地があった。 A boiler device that circulates exhaust gas performs combustion adjustment based on the normal combustion state in which the exhaust gas is circulated. Therefore, oxygen is not mixed in an exhaust gas having a lower oxygen concentration than the combustion air. The concentration will be higher than expected. In particular, when the exhaust gas ratio is adjusted to be high during normal combustion, the difference in the amount of oxygen contained in the combustion air becomes large between ignition when the exhaust gas is not circulated and normal combustion. In this regard, in Patent Document 1, although the opening degree of the damper is controlled to prevent harmful effects caused by excess oxygen at the time of ignition, it is necessary to add damper control at the time of ignition. Further, in a boiler apparatus in which proportional control is performed in which the supply amount of fuel gas is proportional to the supply amount of combustion air, it is difficult to adjust the air ratio in accordance with ignition that is different from normal combustion. As described above, the conventional technology has room for improvement in terms of surely preventing the ignition failure.
　本発明は、排ガス循環を行うボイラ装置において、着火時における酸素濃度過剰を確実に防止し、安定した着火を実現できる構成を提供することを目的とする。 An object of the present invention is to provide a configuration capable of reliably preventing excessive oxygen concentration during ignition and realizing stable ignition in a boiler device that performs exhaust gas circulation.
　本発明は、ボイラと、前記ボイラに燃料ガスを供給する燃料供給ラインと、前記燃料ガスに混合する燃焼用空気を前記ボイラに供給する空気供給ライン及び該空気供給ラインに接続される送風機を有する空気供給部と、前記ボイラの内部に配置され、前記燃料ガスと前記燃焼用空気の混合気を燃焼させるバーナと、前記混合気の燃焼によって生じる排ガスを前記ボイラから排出する排出ラインと、前記排出ラインと前記空気供給部を接続し、前記排ガスの一部を前記空気供給部に循環させる排ガス循環ラインと、前記燃料供給ラインの経路上に一側の端部と他側の端部が接続されるバイパスラインと、前記バイパスラインに配置されるバイパス弁と、通常の燃焼時は前記バイパス弁を閉じ、前記バーナの着火時は、前記バイパス弁を開いて前記バイパスラインにも前記燃料ガスを流通させることにより、通常の燃焼時に比べて前記燃料ガスの供給量を大きくする制御を行う制御部と、を備えることを特徴とするボイラ装置に関する。 The present invention includes a boiler, a fuel supply line for supplying fuel gas to the boiler, an air supply line for supplying combustion air mixed with the fuel gas to the boiler, and a blower connected to the air supply line. An air supply unit, a burner which is disposed inside the boiler and combusts an air-fuel mixture of the fuel gas and the combustion air, an exhaust line which exhausts exhaust gas generated by the combustion of the air-fuel mixture, and the exhaust An exhaust gas circulation line that connects the line and the air supply unit, and circulates part of the exhaust gas to the air supply unit, and an end on one side and an end on the other side are connected on the path of the fuel supply line. The bypass line, the bypass valve disposed in the bypass line, and close the bypass valve during normal combustion, and open the bypass valve when the burner ignites. By also serial bypass line circulating the fuel gas, and a control unit in comparison with a normal combustion control is performed to increase the supply amount of the fuel gas to a boiler apparatus, characterized in that it comprises a.
　前記ボイラ装置は、前記燃料供給ラインに配置され、前記燃料ガスを減圧する燃料ガス減圧部材を更に備え、前記バイパスラインは、一側の端部が前記燃料ガス減圧部材の上流側に接続され、他側の端部が前記燃料ガス減圧部材の下流側に接続されることが好ましい。 The boiler device further includes a fuel gas decompression member that is disposed in the fuel supply line and decompresses the fuel gas, and the bypass line has one end connected to the upstream side of the fuel gas decompression member, The other end is preferably connected to the downstream side of the fuel gas decompression member.
　前記ボイラ装置は、前記排ガス循環ラインに配置され、前記排ガスの流量を調整する排ガス流量調整部を更に備え、前記制御部は、前記バーナの着火時は、前記空気供給部に前記排ガスが供給されないように前記排ガス流量調整部を調整し、前記バーナの着火から所定時間経過後に前記空気供給部に前記排ガスの供給が開始されるように前記排ガス流量調整部を調整する制御を行うことが好ましい。 The boiler device further includes an exhaust gas flow rate adjusting unit that is disposed in the exhaust gas circulation line and adjusts the flow rate of the exhaust gas, and the control unit does not supply the exhaust gas to the air supply unit when the burner is ignited. It is preferable to adjust the exhaust gas flow rate adjusting unit so that the exhaust gas flow rate adjusting unit is adjusted so that supply of the exhaust gas to the air supply unit is started after a predetermined time has elapsed since the ignition of the burner.
　本発明によれば、排ガス循環を行うボイラ装置において、着火時における酸素濃度過剰を確実に防止し、安定した着火を実現できる構成を提供できる。 According to the present invention, in a boiler device that performs exhaust gas circulation, it is possible to provide a configuration that can reliably prevent excessive oxygen concentration during ignition and realize stable ignition.
本発明の一実施形態であるボイラ装置を概略的に示した図である。It is the figure which showed roughly the boiler apparatus which is one Embodiment of this invention. 着火前後におけるバイパス弁及び排ガス流量調整ダンパの開閉制御を概略的に示すタイミングチャートである。4 is a timing chart schematically showing opening / closing control of a bypass valve and an exhaust gas flow rate adjustment damper before and after ignition.
　以下、本発明のボイラ装置の好ましい一実施形態について、図面を参照しながら説明する。本実施形態のボイラ装置１は、水を加熱して蒸気の生成を行う蒸気ボイラであり、負荷機器（図示省略）に蒸気を供給するものである。なお、本明細書における「ライン」とは、流路、経路、管路等の流体の流通が可能なラインの総称である。 Hereinafter, a preferred embodiment of the boiler device of the present invention will be described with reference to the drawings. The boiler apparatus 1 of this embodiment is a steam boiler that generates steam by heating water, and supplies steam to a load device (not shown). The “line” in the present specification is a general term for lines capable of flowing a fluid such as a flow path, a path, and a pipeline.
　図１に示すように、本実施形態のボイラ装置１は、ボイラ２と、燃料供給部３と、空気供給部４と、排ガス循環ライン１９と、蒸気ライン２０と、給水部５と、制御装置６と、を備える。 As shown in FIG. 1, the boiler apparatus 1 of this embodiment is the boiler 2, the fuel supply part 3, the air supply part 4, the exhaust gas circulation line 19, the steam line 20, the water supply part 5, and the control apparatus. 6.
　ボイラ２は、ボイラ筐体１１と、ボイラ筐体１１の内部に配置される複数の水管１２と、燃料ガスに燃焼用空気が混合される給気ダクト１７と、燃料ガスと燃焼用空気の混合気を燃焼するバーナ１５と、排ガスをボイラ筐体１１の外部に排出する排出ラインとしての排気筒１８と、を備える。 The boiler 2 includes a boiler casing 11, a plurality of water pipes 12 disposed inside the boiler casing 11, an air supply duct 17 in which combustion air is mixed with fuel gas, and a mixture of fuel gas and combustion air. A burner 15 that burns air and an exhaust cylinder 18 as an exhaust line that exhausts exhaust gas to the outside of the boiler casing 11 are provided.
　ボイラ筐体１１は、平面視矩形形状の直方体状に形成される。複数の水管１２は、ボイラ筐体１１の内部に、複数の水管１２が長手方向及び幅方向に所定の間隔をあけて配列される。複数の水管１２は、その上端部が上部ヘッダ（図示省略）に接続されるとともに、その下端部が下部ヘッダ（図示省略）に接続された状態でボイラ筐体１１の内部に保持されている。なお、ボイラ筐体１１の形状は、上述の直方体状に形成されるものに限定されない。例えば、丸型に形成されたボイラ筐体を用いることもできる。 The boiler casing 11 is formed in a rectangular parallelepiped shape in plan view. The plurality of water tubes 12 are arranged inside the boiler housing 11 with a predetermined interval in the longitudinal direction and the width direction. The plurality of water pipes 12 are held inside the boiler casing 11 with their upper ends connected to an upper header (not shown) and their lower ends connected to a lower header (not shown). In addition, the shape of the boiler housing | casing 11 is not limited to what is formed in the above-mentioned rectangular parallelepiped shape. For example, a boiler housing formed in a round shape can be used.
　給気ダクト１７は、ボイラ筐体１１の長手方向の一端側に接続される。この給気ダクト１７に燃料供給部３から燃料ガスが供給されるとともに、空気供給部４から燃焼用空気が供給される。 The air supply duct 17 is connected to one end side of the boiler casing 11 in the longitudinal direction. Fuel gas is supplied from the fuel supply unit 3 to the air supply duct 17 and combustion air is supplied from the air supply unit 4.
　バーナ１５は、ボイラ筐体１１における給気ダクト１７が接続される部分（給気口）に配置され、燃料ガスと燃焼用空気の混合気を燃焼して複数の水管１２の水を過熱し、蒸気を発生させる。 The burner 15 is disposed in a portion (air supply port) to which the air supply duct 17 is connected in the boiler casing 11, burns a mixture of fuel gas and combustion air, and superheats water in the plurality of water pipes 12. Generate steam.
　排気筒１８は、燃焼によって生じた排ガスをボイラ筐体１１の外部に排出するための排出ラインであり、ボイラ筐体１１の長手方向の他端側に接続される。 The exhaust cylinder 18 is a discharge line for discharging exhaust gas generated by combustion to the outside of the boiler casing 11, and is connected to the other end side in the longitudinal direction of the boiler casing 11.
　次に、燃料供給部３について説明する。燃料供給部３は、ボイラ２に燃料を供給するための構成である。燃料供給部３は、燃料供給ライン３１と、ガバナ３２と、開閉弁３３と、第１オリフィス３４と、第２オリフィス３５と、バイパスライン３６と、バイパス弁３７と、を備える。 Next, the fuel supply unit 3 will be described. The fuel supply unit 3 is configured to supply fuel to the boiler 2. The fuel supply unit 3 includes a fuel supply line 31, a governor 32, an on-off valve 33, a first orifice 34, a second orifice 35, a bypass line 36, and a bypass valve 37.
　燃料供給ライン３１は、その上流側の端部が燃料供給源（図示両略）に接続され、その下流側の端部が給気ダクト１７に接続される。ガバナ３２は、燃料供給ライン３１を流れる燃料ガスの圧力を調整する調圧手段である。本実施形態のガバナ３２は、空気供給ライン４２に接続される連通管（図示省略）により、空気供給ライン４２の圧力を受けており、いわゆる均圧弁方式で、燃焼用空気の供給量に燃料ガスの供給量が比例するように燃料ガスの流量を制御する比例制御弁としての機能を有する。開閉弁３３は、ガバナ３２の下流側に配置される。開閉弁３３によって、燃料供給ライン３１の流路の開放又は閉止が可能になっている。第１オリフィス３４は、開閉弁３３の下流側に配置され、燃料ガスの減圧を行う。 The fuel supply line 31 has an upstream end connected to a fuel supply source (not shown) and a downstream end connected to the air supply duct 17. The governor 32 is a pressure adjusting unit that adjusts the pressure of the fuel gas flowing through the fuel supply line 31. The governor 32 of the present embodiment receives the pressure of the air supply line 42 by a communication pipe (not shown) connected to the air supply line 42, and the fuel gas is supplied to the supply amount of combustion air by a so-called equalizing valve system. It has a function as a proportional control valve for controlling the flow rate of the fuel gas so that the supply amount of fuel is proportional. The on-off valve 33 is disposed on the downstream side of the governor 32. The on-off valve 33 can open or close the flow path of the fuel supply line 31. The first orifice 34 is disposed on the downstream side of the on-off valve 33 and decompresses the fuel gas.
　第２オリフィス３５は、燃料ガスを減圧する燃料ガス減圧部材であり、第１オリフィス３４の下流側に配置される。バイパスライン３６は、この第２オリフィス３５の上流側に接続されるとともに、下流側に接続される。バイパス弁３７は、バイパスライン３６に配置される。バイパス弁３７は、バイパスライン３６の流路の開放又は閉止を行う電磁弁である。本実施形態では、このバイパス弁３７が閉状態となってバイパスライン３６の流路が閉止されている状態を基準として通常の燃焼時の燃焼調整が行われている。なお、ここでいう通常の燃焼時とは、着火後の燃焼状態（例えば、ボイラ２によって生成された蒸気が負荷機器に供給されている状態）のことをいう。 The second orifice 35 is a fuel gas decompression member that decompresses the fuel gas, and is disposed on the downstream side of the first orifice 34. The bypass line 36 is connected to the upstream side of the second orifice 35 and to the downstream side. The bypass valve 37 is disposed in the bypass line 36. The bypass valve 37 is an electromagnetic valve that opens or closes the flow path of the bypass line 36. In the present embodiment, combustion adjustment at the time of normal combustion is performed based on the state where the bypass valve 37 is closed and the flow path of the bypass line 36 is closed. The normal combustion here means a combustion state after ignition (for example, a state in which steam generated by the boiler 2 is supplied to the load device).
　次に、空気供給部４について説明する。空気供給部４は、ボイラ２に燃焼用空気を供給するための構成である。本実施形態の空気供給部４は、送風機４１と、空気供給ライン４２と、燃焼用空気ダンパ４３と、を備える。 Next, the air supply unit 4 will be described. The air supply unit 4 is configured to supply combustion air to the boiler 2. The air supply unit 4 of this embodiment includes a blower 41, an air supply line 42, and a combustion air damper 43.
　送風機４１は、ファンと、このファンを回転させるモータと、インバータと、を含んで構成される。送風機４１は、インバータに入力される周波数に応じてモータの回転数を調整可能になっている。送風機４１には、後述する排ガス循環ライン１９が接続されており、ボイラ筐体１１から外部に排出される排ガスの一部を送風機４１に導入可能になっている。 The blower 41 includes a fan, a motor that rotates the fan, and an inverter. The blower 41 can adjust the rotation speed of the motor according to the frequency input to the inverter. An exhaust gas circulation line 19 to be described later is connected to the blower 41 so that a part of the exhaust gas discharged from the boiler casing 11 to the outside can be introduced into the blower 41.
　空気供給ライン４２は、その上流側の端部が送風機４１に接続されるとともに、下流側の端部が給気ダクト１７に接続される。送風機４１は、ファンの回転によって空気を取り込み、この空気供給ライン４２を介して燃焼用空気をボイラ２に送り込む。 The air supply line 42 has an upstream end connected to the blower 41 and a downstream end connected to the air supply duct 17. The blower 41 takes in air by rotation of the fan, and sends combustion air to the boiler 2 through the air supply line 42.
　燃焼用空気ダンパ４３は、燃焼用空気の流路を塞いだ閉状態と、この閉状態から回転し、燃焼用空気の流路を開放した開状態との間で回転可能に空気供給ライン４２に配置される。また、燃焼用空気ダンパ４３は、燃焼用空気の供給量を調整するため開度変更可能に構成される。 The combustion air damper 43 is connected to the air supply line 42 so as to be rotatable between a closed state in which the combustion air flow path is closed and an open state in which the combustion air flow path is opened and the combustion air flow path is opened. Be placed. Further, the combustion air damper 43 is configured to be able to change the opening degree in order to adjust the supply amount of the combustion air.
　次に、排ガス循環ライン１９について説明する。排ガス循環ライン１９は、その上流側の端部が排気筒１８に接続されるとともに、下流側の端部が送風機４１(空気供給部４)に接続される。ボイラ筐体１１の内部から排気筒１８に排出された排ガスの一部は、この排ガス循環ライン１９によって送風機４１に送られ、外気と混合されてボイラ２に再び送り込まれる。 Next, the exhaust gas circulation line 19 will be described. The exhaust gas circulation line 19 has an upstream end connected to the exhaust pipe 18 and a downstream end connected to the blower 41 (air supply unit 4). A part of the exhaust gas discharged from the inside of the boiler housing 11 to the exhaust pipe 18 is sent to the blower 41 by the exhaust gas circulation line 19, mixed with outside air, and sent again to the boiler 2.
　排ガス循環ライン１９には、排ガス流量調整ダンパ２７が配置される。排ガス流量調整ダンパ２７は、その開度を調整可能ないわゆる多位置ダンパである。本実施形態の排ガス流量調整ダンパ２７は、排ガス循環ライン１９の内部の排ガスの流路を塞いだ閉状態と、この閉状態から所定の角度（例えば、９０度）回転し、排ガスの流路を開放した開状態と、の間で回転可能になっている。また、排ガス流量調整ダンパ２７は、上述のように多位置ダンパであり、開状態における開度を調整可能になっている。この機能により、送風機４１に送られる排ガスの混合率の調整が可能になっている。このように、排ガス流量調整ダンパ２７は、その開度が調整可能に構成されることにより、流量の調整も含めて排ガスを送風機４１に供給するか否かを調整できる排ガス流量調整部として機能する。なお、本実施形態では、排ガス循環ライン１９の内部の排ガスの流路が開放されており、排ガスの一部が送風機４１に導入されている状態を基準に通常時の燃焼調整が行われている。 In the exhaust gas circulation line 19, an exhaust gas flow adjustment damper 27 is arranged. The exhaust gas flow rate adjustment damper 27 is a so-called multi-position damper whose opening degree can be adjusted. The exhaust gas flow rate adjusting damper 27 of the present embodiment closes the exhaust gas flow path inside the exhaust gas circulation line 19 and rotates a predetermined angle (for example, 90 degrees) from this closed state, thereby changing the exhaust gas flow path. It can be rotated between the open state and the open state. Further, the exhaust gas flow rate adjustment damper 27 is a multi-position damper as described above, and the opening degree in the open state can be adjusted. With this function, the mixing ratio of the exhaust gas sent to the blower 41 can be adjusted. In this way, the exhaust gas flow rate adjustment damper 27 functions as an exhaust gas flow rate adjustment unit that can adjust whether or not to supply exhaust gas to the blower 41, including the adjustment of the flow rate, by being configured so that the opening degree can be adjusted. . In the present embodiment, the exhaust gas flow path inside the exhaust gas circulation line 19 is opened, and the normal combustion adjustment is performed based on the state where a part of the exhaust gas is introduced into the blower 41. .
　蒸気ライン２０は、上流側の端部がボイラ２に接続されるとともに、下流側の端部が負荷機器（図示省略）に接続される。この蒸気ライン２０を介してボイラ２で生成された蒸気が負荷機器に供給される。 The steam line 20 has an upstream end connected to the boiler 2 and a downstream end connected to a load device (not shown). Steam generated in the boiler 2 is supplied to the load device via the steam line 20.
　次に、給水部５について説明する。給水部５は、ボイラ２に蒸気を生成するための水を給水するための構成である。本実施形態の給水部５は、給水ライン５１と、熱交換器５２と、を備える。給水ライン５１は、上流側の端部が給水源（図示省略）に接続されるとともに、下流側の端部がボイラ２に接続される。熱交換器５２は、排気筒１８の内部に配置される。熱交換器５２は、給水ライン５１の内部を流れる水と、排気筒１８を流れる排ガスとの間で熱交換を行う。これにより、給水ライン５１を流れる水が予熱された状態でボイラ２に供給されることになる。 Next, the water supply unit 5 will be described. The water supply unit 5 is configured to supply water for generating steam to the boiler 2. The water supply unit 5 of the present embodiment includes a water supply line 51 and a heat exchanger 52. The water supply line 51 has an upstream end connected to a water supply source (not shown) and a downstream end connected to the boiler 2. The heat exchanger 52 is disposed inside the exhaust pipe 18. The heat exchanger 52 performs heat exchange between the water flowing inside the water supply line 51 and the exhaust gas flowing through the exhaust pipe 18. Thereby, the water flowing through the water supply line 51 is supplied to the boiler 2 in a preheated state.
　次に、制御装置６について説明する。制御装置６は、送風機４１、燃焼用空気ダンパ４３、バイパス弁３７、各圧力センサ等と電気的に接続されている。本実施形態の制御装置６は、制御部６１と、記憶部６２と、を備える。制御部６１は、燃料ガス及び燃焼用空気の供給量の調整やボイラ２の着火制御や燃焼制御等の各種の制御を行う。記憶部６２には、制御部６１が制御を行うための各種の情報が記憶される。 Next, the control device 6 will be described. The control device 6 is electrically connected to the blower 41, the combustion air damper 43, the bypass valve 37, each pressure sensor, and the like. The control device 6 of this embodiment includes a control unit 61 and a storage unit 62. The controller 61 performs various controls such as adjustment of the supply amounts of fuel gas and combustion air, ignition control of the boiler 2, and combustion control. The storage unit 62 stores various types of information for the control unit 61 to perform control.
　本実施形態の制御部６１は、着火時において、排ガスが循環していないことに起因する着火不良を防止するために、通常の燃焼制御時よりも着火時の燃料ガスの流量を大きくする制御を行う。次に、制御部６１による着火時における燃料ガスの供給制御及び排ガスの循環制御について説明する。図２は、着火前後におけるバイパス弁３７及び排ガス流量調整ダンパ２７の開閉制御を概略的に示すタイミングチャートである。 The control unit 61 of the present embodiment performs control to increase the flow rate of the fuel gas at the time of ignition than at the time of normal combustion control in order to prevent ignition failure due to the exhaust gas not being circulated at the time of ignition. Do. Next, fuel gas supply control and exhaust gas circulation control during ignition by the control unit 61 will be described. FIG. 2 is a timing chart schematically showing opening / closing control of the bypass valve 37 and the exhaust gas flow rate adjustment damper 27 before and after ignition.
　ボイラ２の運転制御が開始されると、着火を行う前段階としてプレパージ制御が行われる。プレパージ制御は、送風機４１によって空気をボイラ筐体１１に送り込み、ボイラ筐体１１の内部を換気する制御である。図２に示すように、プレパージ制御では、バイパス弁３７は閉状態に制御されるとともに、排ガス循環ライン１９に配置される排ガス流量調整ダンパ２７も閉状態に制御される。 When the operation control of the boiler 2 is started, pre-purge control is performed as a stage before ignition. The pre-purge control is control in which air is sent to the boiler casing 11 by the blower 41 and the inside of the boiler casing 11 is ventilated. As shown in FIG. 2, in the pre-purge control, the bypass valve 37 is controlled to be closed, and the exhaust gas flow rate adjustment damper 27 disposed in the exhaust gas circulation line 19 is also controlled to be closed.
　プレパージが完了すると着火制御に移行する。着火制御が開始されると、制御部６１は、バイパス弁３７を開状態にしてバイパスライン３６の流路を開放する制御を行う。バイパスライン３６を流通する燃料ガスは、第２オリフィス３５によって減圧されることなく燃料供給ライン３１の下流側に送られる。従って、バイパスライン３６が閉鎖されており、ボイラ２に供給される全ての燃料ガスが第２オリフィス３５によって減圧されている状態（通常の燃焼時）に比べ着火時の方が燃料ガスの供給量が大きくなる。 When the pre-purge is completed, the control shifts to ignition control. When the ignition control is started, the control unit 61 performs control to open the flow path of the bypass line 36 by opening the bypass valve 37. The fuel gas flowing through the bypass line 36 is sent to the downstream side of the fuel supply line 31 without being depressurized by the second orifice 35. Therefore, the amount of fuel gas supplied during ignition is higher than when the bypass line 36 is closed and all the fuel gas supplied to the boiler 2 is decompressed by the second orifice 35 (during normal combustion). Becomes larger.
　バーナ１５の着火が完了すると燃焼制御に移行する。制御部６１は、着火開始より所定時間（数秒から十数秒程度）経過後に、バイパス弁３７を閉状態に制御するとともに、排ガス流量調整ダンパ２７を開状態に制御する（図２参照）。バイパス弁３７が閉じられることにより、バイパスライン３６の流路が閉鎖され、ボイラ２に供給される燃料ガスの供給量は着火時に比べて小さくなる。また。排ガス流量調整ダンパ２７が開かれることにより、排ガス循環ライン１９の流路が開放され、着火後に生じた排ガスが送風機４１（空気供給部４）に導入される。 When the ignition of the burner 15 is completed, it shifts to combustion control. The control unit 61 controls the bypass valve 37 to be closed and the exhaust gas flow rate adjustment damper 27 to be opened (see FIG. 2) after a predetermined time (several seconds to several tens of seconds) has elapsed since the start of ignition. By closing the bypass valve 37, the flow path of the bypass line 36 is closed, and the supply amount of the fuel gas supplied to the boiler 2 becomes smaller than that at the time of ignition. Also. By opening the exhaust gas flow rate adjustment damper 27, the flow path of the exhaust gas circulation line 19 is opened, and the exhaust gas generated after ignition is introduced into the blower 41 (air supply unit 4).
　上述のように、バイパスライン３６の流路が閉鎖されており、かつ、排ガスが送風機４１に導入されている状態（酸素濃度が低い排ガスと外気が混合された状態）を基準に燃焼調整が行われているので、燃料ガスはバイパス弁３７が閉じられることにより適切な量でボイラ２に供給され、燃焼用空気についても排ガス流量調整ダンパ２７が開かれることにより排ガスが混合されて適切な量でボイラ２に供給される。 As described above, combustion adjustment is performed based on the state where the flow path of the bypass line 36 is closed and the exhaust gas is introduced into the blower 41 (the state where the exhaust gas having a low oxygen concentration and the outside air are mixed). Therefore, the fuel gas is supplied to the boiler 2 in an appropriate amount when the bypass valve 37 is closed, and the exhaust gas is mixed in the appropriate amount with respect to the combustion air by opening the exhaust gas flow adjustment damper 27. It is supplied to the boiler 2.
　燃焼制御に移行したボイラ２は、排ガスが混合された燃焼用空気と燃料ガスの混合気の燃焼によって水管１２内部の水を加熱して蒸気を生成させる。生成した蒸気は、蒸気ライン２０を通じて負荷機器に供給される。一方、混合気の燃焼によって生じた排ガスは、排気筒１８に送られる。排気筒１８では、排ガスの一部が排ガス循環ライン１９を通じて送風機４１に送られ、残りが外部に排出される。送風機４１に送られた排ガスは、外部の空気と混合されて空気供給ライン４２を通じてボイラ２に循環する。 The boiler 2 that has shifted to the combustion control heats the water in the water pipe 12 by the combustion of a mixture of combustion air mixed with exhaust gas and fuel gas to generate steam. The generated steam is supplied to the load equipment through the steam line 20. On the other hand, the exhaust gas generated by the combustion of the air-fuel mixture is sent to the exhaust cylinder 18. In the exhaust cylinder 18, a part of the exhaust gas is sent to the blower 41 through the exhaust gas circulation line 19 and the rest is discharged to the outside. The exhaust gas sent to the blower 41 is mixed with external air and circulated to the boiler 2 through the air supply line 42.
　以上説明した本実施形態のボイラ装置１によれば、以下のような効果を奏する。 According to the boiler device 1 of the present embodiment described above, the following effects are obtained.
　本実施形態のボイラ装置１は、燃料供給ライン３１の経路上に一側の端部と他側の端部が接続されるバイパスライン３６と、バイパスライン３６に配置されるバイパス弁３７と、通常の燃焼時はバイパス弁３７を閉じ、バーナ１５の着火時は、バイパス弁３７を開いてバイパスライン３６にも燃料ガスを流通させることにより、通常の燃焼時に比べて前記燃料ガスの供給量を大きくする制御を行う制御部６１と、を備える。これにより、着火時において、通常の燃焼時に比べ燃料ガスの供給量が大きくなるので、酸素濃度が低い排ガスが混合されていないために、燃料ガスに対して酸素濃度が過剰となって生じる着火の不具合を確実に防止できる。従って、排ガス循環を行うボイラ装置１において、空気と混合される排ガスの比率が高い場合であっても、安定した着火を実現できる。また、燃焼用空気ダンパ４３の制御を複雑化させることなく着火を安定化できる。本実施形態のように、燃焼用空気の供給量に燃料ガスの供給量が比例する比例制御が行われるガス焚きのボイラ装置１においても、複雑な構成や制御を加えることなく、通常の燃焼時よりも着火時の燃料ガスの供給量を増やす構成を実現できる。即ち、燃焼用空気の供給量に燃料ガスの供給量が比例するように燃料ガスの流量を調整する又は燃料ガスの供給量に燃焼用空気の供給量が比例するように燃焼用空気の供給量を調整する比例制御が行われるボイラ装置においても、本発明の構成であれば、比例制御を行うための構成を複雑化することなく、通常の燃焼時と異なる状況にある着火時の空気比を適切に調整することができるのである。 The boiler apparatus 1 of the present embodiment includes a bypass line 36 in which an end on one side and an end on the other side are connected on the path of the fuel supply line 31, a bypass valve 37 disposed in the bypass line 36, When the burner 15 is ignited, the bypass valve 37 is closed. When the burner 15 is ignited, the bypass valve 37 is opened and the fuel gas is also circulated through the bypass line 36. And a control unit 61 that performs control. As a result, the amount of fuel gas supplied at the time of ignition is larger than that at the time of normal combustion. Therefore, since the exhaust gas with a low oxygen concentration is not mixed, the oxygen concentration is excessive with respect to the fuel gas. Defects can be reliably prevented. Therefore, in the boiler apparatus 1 that performs exhaust gas circulation, stable ignition can be realized even when the ratio of exhaust gas mixed with air is high. Further, ignition can be stabilized without complicating the control of the combustion air damper 43. Even in the gas-fired boiler apparatus 1 in which proportional control is performed in which the supply amount of fuel gas is proportional to the supply amount of combustion air as in the present embodiment, during normal combustion without adding a complicated configuration and control. Thus, it is possible to realize a configuration in which the amount of fuel gas supplied during ignition is increased. That is, the fuel gas flow rate is adjusted so that the fuel gas supply amount is proportional to the combustion air supply amount, or the combustion air supply amount is proportional to the fuel gas supply amount. Even in a boiler apparatus in which proportional control is performed to adjust the ratio, the air ratio at the time of ignition in a situation different from that at the time of normal combustion can be obtained without complicating the structure for performing proportional control with the configuration of the present invention. It can be adjusted appropriately.
　バイパスライン３６は、一側の端部が第２オリフィス３５の上流側に接続され、他側の端部が第２オリフィス３５の下流側に接続される。これにより、バイパスライン３６を通過する燃料ガスは、第２オリフィス３５によって減圧されないので、バイパスライン３６を開放したときの燃料ガスの流量の増加量を確実に大きくできる構成をシンプルな構造で実現できる。 The bypass line 36 has one end connected to the upstream side of the second orifice 35 and the other end connected to the downstream side of the second orifice 35. As a result, the fuel gas passing through the bypass line 36 is not decompressed by the second orifice 35, so that a configuration that can reliably increase the amount of increase in the flow rate of the fuel gas when the bypass line 36 is opened can be realized with a simple structure. .
　制御部６１は、バーナ１５の着火時は、送風機４１（空気供給部４）に排ガスが供給されないように排ガス流量調整ダンパ２７を閉じ、バーナの着火から所定時間経過後に送風機４１に排ガスの供給が開始されるように排ガス流量調整ダンパ２７を開く制御を行う。これにより、プレパージや着火開始時に排ガス循環ライン１９の内部の空気（残留した排ガス）が送風機４１に供給される事態を確実に防止できるとともに、排ガス発生にあわせて排ガスを循環させる制御にスムーズに移行させることができる。 When the burner 15 is ignited, the control unit 61 closes the exhaust gas flow rate adjustment damper 27 so that the exhaust gas is not supplied to the blower 41 (air supply unit 4), and the exhaust gas is supplied to the blower 41 after a predetermined time has elapsed from the ignition of the burner. Control is performed to open the exhaust gas flow rate adjustment damper 27 so as to be started. As a result, it is possible to reliably prevent the air (residual exhaust gas) inside the exhaust gas circulation line 19 from being supplied to the blower 41 at the start of pre-purge or ignition, and smoothly shift to control for circulating the exhaust gas as the exhaust gas is generated. Can be made.
　以上、本発明のボイラ装置１の好ましい一実施形態について説明したが、本発明は、上述の実施形態に制限されるものではなく、適宜変更が可能である。例えば、上記実施形態では、バイパス弁３７を閉状態にする制御と、排ガス流量調整ダンパ２７を開状態にする制御を同時に行っているが、時間差を設けてそれぞれ異なるタイミングでこれらの制御を行うようにしてもよい。また、本実施形態では、バイパス弁３７は電気的に制御される電磁弁として構成されているが、事情に応じて適宜変更することができる。例えば、バイパス弁３７にニードル弁やバタフライ弁等の構成を加えてバイパスライン３６を流れる燃料ガスの流量を調整できるように構成することもできる。 As mentioned above, although one preferable embodiment of the boiler apparatus 1 of this invention was described, this invention is not restrict | limited to the above-mentioned embodiment, It can change suitably. For example, in the above embodiment, the control for closing the bypass valve 37 and the control for opening the exhaust gas flow rate adjustment damper 27 are performed at the same time, but these controls are performed at different timings with a time difference. It may be. Further, in the present embodiment, the bypass valve 37 is configured as an electromagnetic valve that is electrically controlled, but may be appropriately changed according to circumstances. For example, a configuration such as a needle valve or a butterfly valve may be added to the bypass valve 37 so that the flow rate of the fuel gas flowing through the bypass line 36 can be adjusted.
　上記実施形態では、排ガス流量調整ダンパ２７によって排ガス流量調整部を構成しているがこの構成は適宜変更できる。例えば、排ガス流量調整部に電磁弁を採用することができる。 In the above embodiment, the exhaust gas flow rate adjusting damper 27 constitutes the exhaust gas flow rate adjusting unit, but this configuration can be changed as appropriate. For example, an electromagnetic valve can be employed in the exhaust gas flow rate adjustment unit.
　上記実施形態では、排ガス循環ライン１９の下流側の端部が送風機４１に接続される構成であるが、この構成は適宜変更できる。例えば、排ガス循環ライン１９の下流側の端部を空気供給ライン４２に接続し、別途設けたファンによって排ガスを空気供給ライン４２に送り込む構成とすることもできる。 In the above embodiment, the downstream end of the exhaust gas circulation line 19 is connected to the blower 41, but this configuration can be changed as appropriate. For example, the downstream end of the exhaust gas circulation line 19 may be connected to the air supply line 42 and the exhaust gas may be sent to the air supply line 42 by a separately provided fan.
　上記実施形態では、排ガス循環ライン１９に配置される排ガス流量調整ダンパ２７によって排ガス流量調整部が構成されているが、この構成に限定されるわけではない。例えば、流量調整ダンパ及び開閉ダンパによって排ガス流量調整部を構成することもできる。流量調整ダンパは、開度調整が可能に構成され、排ガスの混合率を調整するダンパである。また、開閉ダンパは、排ガスを送風機４１に供給するか否かを調整するダンパである。あるいは、開閉ダンパのみで排ガス流量調整部を構成することもできる。このように、排ガス流量調整部の構成は適宜変更することができる。 In the above embodiment, the exhaust gas flow rate adjusting portion 27 is configured by the exhaust gas flow rate adjusting damper 27 arranged in the exhaust gas circulation line 19, but the configuration is not limited to this. For example, the exhaust gas flow rate adjustment unit can be configured by a flow rate adjustment damper and an open / close damper. The flow rate adjustment damper is configured to be able to adjust the opening degree, and is a damper that adjusts the mixing ratio of the exhaust gas. The open / close damper is a damper that adjusts whether exhaust gas is supplied to the blower 41. Alternatively, the exhaust gas flow rate adjustment unit can be configured with only the open / close damper. Thus, the configuration of the exhaust gas flow rate adjusting unit can be changed as appropriate.
　１　ボイラ装置
　２　ボイラ
　４　空気供給部
　１５　バーナ
　１８　排気筒（排出ライン）
　１９　排ガス循環ライン
　２７　排ガス流量調整ダンパ（排ガス流量調整部）
　３１　燃料供給ライン
　３５　第２オリフィス（燃料ガス減圧部材）
　３６　バイパスライン
　３７　バイパス弁
　４１　送風機
　４２　空気供給ライン
　６１　制御部 DESCRIPTION OF SYMBOLS 1 Boiler apparatus 2 Boiler 4 Air supply part 15 Burner 18 Exhaust pipe (discharge line)
19 Exhaust gas circulation line 27 Exhaust gas flow rate adjustment damper (Exhaust gas flow rate adjustment part)
31 Fuel supply line 35 Second orifice (fuel gas decompression member)
36 Bypass line 37 Bypass valve 41 Blower 42 Air supply line 61 Control unit

Claims (3)

  1. 　ボイラと、
    　前記ボイラに燃料ガスを供給する燃料供給ラインと、
    　前記燃料ガスに混合する燃焼用空気を前記ボイラに供給する空気供給ライン及び該空気供給ラインに接続される送風機を有する空気供給部と、
    　前記ボイラの内部に配置され、前記燃料ガスと前記燃焼用空気の混合気を燃焼させるバーナと、
    　前記混合気の燃焼によって生じる排ガスを前記ボイラから排出する排出ラインと、
    　前記排出ラインと前記空気供給部を接続し、前記排ガスの一部を前記空気供給部に循環させる排ガス循環ラインと、
    　前記燃料供給ラインの経路上に一側の端部と他側の端部が接続されるバイパスラインと、
    　前記バイパスラインに配置されるバイパス弁と、
    　通常の燃焼時は前記バイパス弁を閉じ、前記バーナの着火時は、前記バイパス弁を開いて前記バイパスラインにも前記燃料ガスを流通させることにより、通常の燃焼時に比べて前記燃料ガスの供給量を大きくする制御を行う制御部と、
    を備えることを特徴とするボイラ装置。     With a boiler,
    A fuel supply line for supplying fuel gas to the boiler;
    An air supply unit having an air supply line for supplying combustion air mixed with the fuel gas to the boiler and a blower connected to the air supply line;
    A burner that is disposed inside the boiler and burns a mixture of the fuel gas and the combustion air;
    An exhaust line for exhausting exhaust gas generated by combustion of the air-fuel mixture from the boiler;
    An exhaust gas circulation line that connects the exhaust line and the air supply unit and circulates a part of the exhaust gas to the air supply unit;
    A bypass line to which an end on one side and an end on the other side are connected on the path of the fuel supply line;
    A bypass valve disposed in the bypass line;
    During normal combustion, the bypass valve is closed, and when the burner is ignited, the fuel gas is supplied to the bypass line by opening the bypass valve and allowing the fuel gas to flow through the bypass line. A control unit that performs control to increase
    A boiler device comprising:
  2. 　前記燃料供給ラインに配置され、前記燃料ガスを減圧する燃料ガス減圧部材を更に備え、
    　前記バイパスラインは、一側の端部が前記燃料ガス減圧部材の上流側に接続され、他側の端部が前記燃料ガス減圧部材の下流側に接続される請求項１に記載のボイラ装置。     A fuel gas decompression member disposed in the fuel supply line for decompressing the fuel gas;
    2. The boiler device according to claim 1, wherein one end of the bypass line is connected to the upstream side of the fuel gas decompression member, and the other end is connected to the downstream side of the fuel gas decompression member.
  3. 　前記排ガス循環ラインに配置され、前記排ガスの流量を調整する排ガス流量調整部を更に備え、
    　前記制御部は、前記バーナの着火時は、前記空気供給部に前記排ガスが供給されないように前記排ガス流量調整部を調整し、前記バーナの着火から所定時間経過後に前記空気供給部に前記排ガスの供給が開始されるように前記排ガス流量調整部を調整する制御を行う請求項１又は２に記載のボイラ装置。     An exhaust gas flow rate adjusting unit that is disposed in the exhaust gas circulation line and adjusts the flow rate of the exhaust gas;
    The control unit adjusts the exhaust gas flow rate adjusting unit so that the exhaust gas is not supplied to the air supply unit when the burner is ignited. The boiler apparatus of Claim 1 or 2 which performs control which adjusts the said waste gas flow volume adjustment part so that supply may be started.
PCT/JP2016/050484 2015-03-31 2016-01-08 Boiler device WO2016157925A1 (en)

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KR102537965B1 (en) 2021-03-24 2023-06-01 우성씨엔에스(주) Arraratus for premixing combustion air and fuel gas

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