JP3307560B2 - Combustion equipment - Google Patents
Combustion equipmentInfo
- Publication number
- JP3307560B2 JP3307560B2 JP12735497A JP12735497A JP3307560B2 JP 3307560 B2 JP3307560 B2 JP 3307560B2 JP 12735497 A JP12735497 A JP 12735497A JP 12735497 A JP12735497 A JP 12735497A JP 3307560 B2 JP3307560 B2 JP 3307560B2
- Authority
- JP
- Japan
- Prior art keywords
- burner
- thermocouple
- air ratio
- thermoelectromotive force
- fuel supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Combustion (AREA)
- Regulation And Control Of Combustion (AREA)
Description
【０００１】[0001]
【発明の属する技術の分野】本発明は、空気比を一定に
保って安定した燃焼を行う燃焼装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus for performing stable combustion while maintaining a constant air ratio.
【０００２】[0002]
【従来の技術】従来、燃焼装置であるガス給湯器やガス
ファンヒータにおいて、バーナへの燃料ガスの供給量を
調節する比例制御弁と、バーナに燃焼用空気を供給する
送風機を備え、例えば吸気管や排気管の閉塞等の外乱に
より、燃焼用空気の供給量が変動しても、バーナに対す
る燃料ガスと燃焼用空気の供給量の比が一定に保たれる
ように、バーナへの燃料ガスの供給量を調節する、いわ
ゆる空燃比制御を行うことで、失火や不完全燃焼が生じ
るのを防止し、安定した燃焼を行うようにしたものがあ
る。2. Description of the Related Art Conventionally, a gas water heater or a gas fan heater as a combustion device is provided with a proportional control valve for adjusting a supply amount of fuel gas to a burner and a blower for supplying combustion air to the burner. Even if the supply amount of combustion air fluctuates due to disturbance such as blockage of a pipe or an exhaust pipe, the fuel gas supply to the burner is maintained so that the ratio of the supply amount of fuel gas to the burner and the supply amount of combustion air are kept constant. There is a method in which misfire or incomplete combustion is prevented from occurring by performing so-called air-fuel ratio control that adjusts a supply amount of the fuel gas, thereby performing stable combustion.
【０００３】この空燃比制御としては、例えば、送風機
により実際にバーナに供給される空気量と、バーナに供
給される燃料ガスの供給量に応じて決定される燃焼に必
要な空気量との比である空気比λ（実際の供給空気量／
必要空気量）を検出する空気比検出手段を設け、該空気
比検出手段により検出される空気比が所定の基準空気比
λB に保たれるように、比例制御弁の開度を制御してバ
ーナへの燃料供給量を調節するものが知られている。As the air-fuel ratio control, for example, the ratio of the amount of air actually supplied to a burner by a blower to the amount of air required for combustion determined according to the amount of fuel gas supplied to the burner is determined. Is the air ratio λ (actual supply air amount /
Air ratio detecting means for detecting the required air amount, and controlling the degree of opening of the proportional control valve so that the air ratio detected by the air ratio detecting means is maintained at a predetermined reference air ratio λB. There is known an apparatus that regulates a fuel supply amount to a fuel cell.
【０００４】そして、空気比検出手段としては、バーナ
の近傍に熱電対を設け、バーナ燃焼時の該熱電対の熱起
電力と空気比との相関関係から、空気比を検出するよう
にしたものがある。この熱電対の熱起電力と空気比との
相関関係は、図１に示すように、空気比λ＝１で熱電対
の熱起電力が最大となる、上に凸の２次曲線となる。As an air ratio detecting means, a thermocouple is provided near the burner, and the air ratio is detected from the correlation between the thermoelectromotive force of the thermocouple and the air ratio when the burner is burning. There is. As shown in FIG. 1, the correlation between the thermoelectromotive force of the thermocouple and the air ratio is an upwardly convex quadratic curve in which the thermoelectromotive force of the thermocouple becomes maximum at the air ratio λ = 1.
【０００５】そのため、前記基準空気比λB をλB ＝１
に設定したときは、λ＞１のときは前記比例制御弁によ
りバーナへの燃料供給量を増やして必要空気量を増やす
ことで空気比を下げ、λ＜１のときには前記比例制御弁
によりバーナへの燃料供給量を減らして必要空気量を減
らし、空気比を上げることで、空気比を基準空気比であ
る１に保って安定した燃焼を行うことができる。Therefore, the reference air ratio λB is set to λB = 1.
When λ> 1, the air ratio is reduced by increasing the fuel supply amount to the burner by the proportional control valve and increasing the required air amount when λ> 1, and when λ <1, the proportional control valve is used to control the burner. By reducing the required amount of air by increasing the fuel supply amount and increasing the air ratio, stable combustion can be performed while maintaining the air ratio at 1, which is the reference air ratio.
【０００６】ところで、空気比を大きくすると、燃焼に
より発生する一酸化炭素（ＣＯ）や窒素酸化物（ＮＯ
ｘ）の生成量が減少する。そこで、前記基準空気比λB
を１よりも大きい、例えばλB ＝１．３に設定し、燃焼
時の一酸化炭素や窒素酸化物の生成量を抑制することが
行われている。When the air ratio is increased, carbon monoxide (CO) and nitrogen oxides (NO
x) is reduced. Therefore, the reference air ratio λB
Is set to be larger than 1, for example, .lambda.B = 1.3, and the production amount of carbon monoxide and nitrogen oxide during combustion is suppressed.
【０００７】しかし、本願発明者らは、このように前記
基準空気比λB を１よりも大きい値に設定したときに、
以下の不都合が生じることを知見した。即ち、前述した
ように、熱電対の熱起電力と空気比との相関グラフは、
λ＝１で熱電対の熱起電力が最大となる上に凸の２次曲
線であるので、前記基準空気比λB （＞１）に対応した
熱電対の熱起電力をＶB とすると、ＶB に対応する空気
比はλB だけではなく、λ＜１の領域にもＶB に対応す
る空気比λM が別に存在する。そのため、熱電対の熱起
電力だけでは、空気比がλB よりも大きいときと、λM
未満であるときとの区別ができないという不都合が生じ
ることを知見した。However, the present inventors set the reference air ratio λB to a value larger than 1 as described above,
It has been found that the following disadvantages occur. That is, as described above, the correlation graph between the thermoelectromotive force of the thermocouple and the air ratio is:
Since the thermoelectromotive force of the thermocouple is a convex quadratic curve at the maximum when λ = 1, the thermoelectromotive force of the thermocouple corresponding to the reference air ratio λB (> 1) is VB, The corresponding air ratio is not only λB, but there is another air ratio λM corresponding to VB in the region where λ <1. Therefore, when the air ratio is larger than λB and λM
It has been found that there is a disadvantage that it cannot be distinguished from when it is less than.
【０００８】通常、このように空気比がλM 未満となる
ことは生じ難いが、例えば排気管の閉塞等によりバーナ
への燃焼用空気の供給量が急激に減少し、空気比が極端
に低下したときには、空気比がλM 未満となることが生
じ得る。この場合、前記不都合により、実際の空気比は
λM 未満であるにも拘らず、空気比が前記基準空気比λ
B よりも大きいと判断されてしまう。Normally, it is difficult for the air ratio to be less than λM as described above. However, for example, the supply amount of combustion air to the burner sharply decreases due to blockage of an exhaust pipe or the like, and the air ratio extremely decreases. Occasionally, the air ratio may be less than λM. In this case, due to the above-mentioned inconvenience, although the actual air ratio is less than λM, the air ratio is not equal to the reference air ratio λM.
It is determined to be larger than B.
【０００９】そして、このように空気比がλM 未満であ
る場合に、λB よりも大きいと判断してしまい、空気比
を前記基準空気比λB に近づけようとして、空気比を小
さくするために比例制御弁によりバーナへの燃料ガスの
供給量を増加させると、空気比が前記基準空気比λB か
ら離れてしまい、該基準空気比λB に近づける制御がな
されないという不都合があった。When the air ratio is smaller than λM, it is determined that the air ratio is larger than λB. In order to make the air ratio closer to the reference air ratio λB, the proportional control is performed to reduce the air ratio. When the amount of fuel gas supplied to the burner is increased by the valve, the air ratio deviates from the reference air ratio λB, and there is a disadvantage that control for approaching the reference air ratio λB is not performed.
【００１０】また、空気比が極端に小さい状態で燃焼が
行われるので、燃焼時に大量の一酸化炭素や窒素酸化物
が発生してしまうという不都合があった。Further, since the combustion is performed in an extremely small air ratio, there is a disadvantage that a large amount of carbon monoxide and nitrogen oxides are generated during the combustion.
【００１１】[0011]
【発明が解決しようとする課題】本発明は、前記不都合
を解消し、空気比が極端に低下したときであっても、空
気比を所定の基準空気比に保つことができる燃焼装置を
提供することを目的とする。SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides a combustion apparatus which can maintain the air ratio at a predetermined reference air ratio even when the air ratio is extremely reduced. The purpose is to:
【００１２】[0012]
【課題を解決するための手段】本発明の第１の実施態様
は、上記目的を達成するため、バーナと、該バーナへの
燃料供給量を調節する比例制御弁と、該バーナに燃焼用
空気を供給する送風機と、該バーナに臨んで設置され、
該バーナの燃焼時に該送風機により該バーナに供給され
る実際の空気量と該バーナの燃焼に必要な空気量との比
である空気比に応じた熱起電力を発生する熱電対と、該
熱電対の熱起電力が、１以上の所定値に設定された基準
空気比に対応した基準電圧に一致するように、該熱電対
の熱起電力が該基準電圧を超えるときは前記比例制御弁
により前記バーナへの燃料供給量を減少させる第１制御
を行い、前記熱電対の熱起電力が前記基準電圧未満であ
るときには、前記比例制御弁により前記バーナへの燃料
供給量を増加させて、前記熱電対の熱起電力が増加する
か減少するかを判別し、増加すると判別したときは、そ
のまま前記比例制御弁により前記バーナへの燃料供給量
を増加させる第２制御を行い、減少すると判別したとき
には前記バーナへの燃料供給量の増加を中止して、前記
熱電対の熱起電力が増加した後に減少するのを検出する
まで、前記バーナへの該燃料供給量を減少させ、次いで
前記第１制御を行う比例弁制御手段とを備えたことを特
徴とする。According to a first embodiment of the present invention, there is provided a burner, a proportional control valve for adjusting a fuel supply amount to the burner, and a combustion air supplied to the burner. And a blower for supplying, and installed facing the burner,
A thermocouple for generating a thermoelectromotive force according to an air ratio which is a ratio of an actual amount of air supplied to the burner by the blower at the time of combustion of the burner and an amount of air required for combustion of the burner; When the thermoelectromotive force of the thermocouple exceeds the reference voltage so that the thermoelectromotive force of the pair matches the reference voltage corresponding to the reference air ratio set to one or more predetermined values, the proportional control valve Performing a first control to reduce the fuel supply amount to the burner, and when the thermoelectromotive force of the thermocouple is less than the reference voltage, increasing the fuel supply amount to the burner by the proportional control valve; It is determined whether the thermoelectromotive force of the thermocouple increases or decreases, and when it is determined that the thermoelectromotive force increases, the second control for increasing the fuel supply amount to the burner is performed by the proportional control valve as it is, and it is determined that the thermoelectric power decreases. Sometimes to the burner A proportional valve that stops increasing the fuel supply amount and reduces the fuel supply amount to the burner until it detects that the thermoelectromotive force of the thermocouple increases and then decreases, and then performs the first control. Control means.
【００１３】熱電対の熱起電力と空気比の相関グラフ
は、空気比が１であるときに熱電対の熱起電力が最大と
なる、上に凸の２次曲線となる。そのため、前記燃料供
給制御手段が、前記熱電対の熱起電力が前記基準電圧未
満であり、前記バーナへの燃料供給量を増加させて空気
比を小さくしたときに、前記熱電対の熱起電力が増加し
たときには、そのときの空気比が、空気比と熱起電力の
相関グラフが右下がり（傾きが負）である領域、即ち空
気比が１を超える領域にあると判断することができる。The correlation graph between the thermoelectromotive force of the thermocouple and the air ratio is a quadratic curve that is upwardly convex, where the thermoelectromotive force of the thermocouple is maximum when the air ratio is 1. Therefore, when the fuel supply control means determines that the thermoelectromotive force of the thermocouple is less than the reference voltage and the air ratio is reduced by increasing the fuel supply amount to the burner, the thermoelectromotive force of the thermocouple is reduced. Is increased, it can be determined that the air ratio at that time is in a region where the correlation graph of the air ratio and the thermoelectromotive force is falling to the right (negative slope), that is, in a region where the air ratio exceeds 1.
【００１４】そこで、本第１の実施形態では、前記比例
弁制御手段は、空気比を小さくしたときに、前記熱電対
の熱起電力が増加したときは、前記比例制御弁により前
記バーナへの燃料供給量を減少させる前記第２制御を実
行し、空気比を前記基準空気比に近づける処理を行う。In the first embodiment, when the air ratio is reduced, and when the thermoelectromotive force of the thermocouple increases, the proportional valve control means controls the proportional valve to the burner. The second control for reducing the fuel supply amount is executed, and a process for bringing the air ratio close to the reference air ratio is performed.
【００１５】一方、前記熱電対の熱起電力が前記基準電
圧未満であり、前記バーナへの燃料供給量を増加させて
空気比を小さくしたときに、前記熱電対の熱起電力が減
少したときには、そのときの空気比が１未満である領域
にあると判断することができる。この場合に、前記空気
比が１を超える領域にあるときと同様、前記バーナへの
燃料供給量を増加させることで空気比を小さくする前記
第２制御を直ちに実行すると、もともと前記基準空気比
よりも小さかった空気比が更に小さくなり、前記基準空
気比から離れてしまう。On the other hand, when the thermoelectromotive force of the thermocouple is less than the reference voltage and the air supply ratio is reduced by increasing the fuel supply amount to the burner and the thermoelectromotive force of the thermocouple decreases. It can be determined that the air ratio at that time is in a region where the air ratio is less than 1. In this case, similarly to the case where the air ratio is in a region exceeding 1, when the second control for reducing the air ratio by increasing the fuel supply amount to the burner is immediately executed, the original air ratio is originally higher than the reference air ratio. The smaller air ratio is further reduced, and deviates from the reference air ratio.
【００１６】かかる場合に、本第１の実施態様によれ
ば、前記比例弁制御手段は、前記バーナへの燃料供給量
の増加を中断し、前記熱電対の熱起電力が上昇後、低下
するのを検出するまで前記バーナへの燃料供給量を減少
させた後、前記第１制御を行う。In such a case, according to the first embodiment, the proportional valve control means interrupts the increase in the amount of fuel supplied to the burner, and the thermoelectromotive force of the thermocouple increases and then decreases. After the amount of fuel supplied to the burner is reduced until the first control is detected, the first control is performed.
【００１７】このように、前記バーナへの燃料供給量を
減少させ（空気比を増大させ）ているときに、前記熱電
対の熱起電力が上昇後、低下するのを検出したというこ
とは、空気比が、熱電対の熱起電力と空気比の相関グラ
フの、空気比が１未満である領域から１を超える領域に
移行したことを意味する。As described above, when the amount of fuel supplied to the burner is being reduced (the air ratio is being increased), it is detected that the thermoelectromotive force of the thermocouple decreases after the rise. This means that the air ratio has shifted from a region where the air ratio is less than 1 to a region where the air ratio exceeds 1 in the correlation graph of the thermoelectromotive force of the thermocouple and the air ratio.
【００１８】そして、空気比が１を超えた後は、前記第
１制御により前記バーナへの燃料供給量を減少させて空
気比を大きくすることで、空気比を前記基準空気比に近
づけることができる。After the air ratio exceeds 1, the first control reduces the fuel supply amount to the burner to increase the air ratio, thereby bringing the air ratio closer to the reference air ratio. it can.
【００１９】したがって、本第１の実施態様によれば、
前記熱電対の熱起電力が前記基準電圧未満であるとき
に、対応する空気比が１を超えているときも、１未満で
あるときにも、空気比を前記基準空気比に近づけること
ができる。Therefore, according to the first embodiment,
When the thermoelectromotive force of the thermocouple is less than the reference voltage, the air ratio can be close to the reference air ratio when the corresponding air ratio is greater than 1 or less than 1. .
【００２０】そのため、空気比が極端に低下した場合で
あっても、空気比を前記基準空気比に近づけることがで
き、空気比が極端に低下した状態で燃焼が続行され、燃
焼時に一酸化炭素や窒素酸化物が大量に発生するのを防
止することができる。Therefore, even when the air ratio is extremely reduced, the air ratio can be brought close to the reference air ratio, and the combustion is continued in the state where the air ratio is extremely reduced, and the carbon monoxide is generated during the combustion. And a large amount of nitrogen oxides can be prevented.
【００２１】また、本発明の第２の実施態様は、バーナ
と、該バーナへの燃料供給量を調節する比例制御弁と、
該バーナに燃焼用空気を供給する送風機と、該バーナに
臨んで設置され、該バーナの燃焼時に該送風機により該
バーナに供給される実際の空気量と該バーナの燃焼に必
要な空気量との比である空気比に応じた熱起電力を発生
する熱電対と、該熱電対の熱起電力が、１以上の所定値
に設定された基準空気比に対応した第１基準電圧に一致
するように、該熱電対の熱起電力が該第１基準電圧を超
えるときは前記比例制御弁により前記バーナへの燃料供
給量を減少させる第１制御を行い、前記熱電対の熱起電
力が前記第１基準電圧未満であるときには、前記比例制
御弁により前記バーナへの燃料供給量を増加させて、前
記熱電対の熱起電力が増加するか減少するかを判別し、
増加すると判別したときは、そのまま前記比例制御弁に
より前記バーナへの燃料供給量を増加させる第２制御を
行い、減少すると判別したときには前記バーナへの燃料
供給量の増加を中止して、前記熱電対の熱起電力が前記
第１基準電圧よりも高い所定の第２基準電圧以上となる
まで、前記バーナへの該燃料供給量を減少させた後に前
記第１制御を行う比例弁制御手段とを備えたことを特徴
とする。According to a second embodiment of the present invention, there is provided a burner, a proportional control valve for adjusting a fuel supply amount to the burner,
A blower for supplying air for combustion to the burner; and a blower installed facing the burner, the amount of air supplied to the burner by the blower when the burner burns and the amount of air required for combustion of the burner. A thermocouple that generates a thermoelectromotive force according to an air ratio, which is a ratio, and a thermoelectromotive force of the thermocouple that matches a first reference voltage corresponding to a reference air ratio set to a predetermined value of at least one. When the thermoelectromotive force of the thermocouple exceeds the first reference voltage, the proportional control valve performs a first control to reduce the fuel supply amount to the burner, and the thermoelectromotive force of the thermocouple is reduced to the second reference voltage. When the voltage is less than one reference voltage, the proportional control valve increases the fuel supply amount to the burner to determine whether the thermoelectromotive force of the thermocouple increases or decreases,
When it is determined to increase, the second control for increasing the fuel supply amount to the burner is performed by the proportional control valve as it is, and when it is determined to decrease, the increase in the fuel supply amount to the burner is stopped, and Proportional valve control means for performing the first control after reducing the fuel supply amount to the burner until the thermoelectromotive force of the pair becomes equal to or higher than a predetermined second reference voltage higher than the first reference voltage. It is characterized by having.
【００２２】空気比が１未満であっても、熱電対の熱起
電力が前記第１基準電圧を超えていれば、前記第１制御
により、バーナへの燃料供給量を減少させて、必要空気
量を減少させることで空気比を大きくし、空気比を前記
基準空気比に近づけることができる。Even if the air ratio is less than 1, if the thermoelectromotive force of the thermocouple exceeds the first reference voltage, the fuel supply to the burner is reduced by the first control to reduce the required air. By reducing the amount, the air ratio can be increased, and the air ratio can be made closer to the reference air ratio.
【００２３】そのため、本第２の実施態様では、前記比
例弁制御手段は、前記バーナへの燃料供給量を増加させ
て空気比を小さくしたときに、前記熱電対の熱起電力が
減少することを判別したとき、即ち、空気比が１未満で
あると判別したときには、燃料供給量の増加を中止し
て、前記熱電対の熱起電力が前記第１基準電圧よりも高
い前記第２基準電圧を超えるまで、燃料供給量を逆に減
少させて空気比を大きくする。Therefore, in the second embodiment, the proportional valve control means may reduce the thermoelectromotive force of the thermocouple when the fuel ratio to the burner is increased to reduce the air ratio. Is determined, that is, when it is determined that the air ratio is less than 1, the increase in the fuel supply amount is stopped, and the thermoelectric power of the thermocouple is higher than the first reference voltage. Until it exceeds, the fuel supply is reduced conversely to increase the air ratio.
【００２４】そして、空気比の増大に応じて前記熱電対
の熱起電力が増加し、前記第２基準電圧を超えた後は、
前記第１の実施態様と同様に、前記第１制御により前記
バーナへの燃料供給量を減少させて空気比を大きくする
ことで、空気比を前記基準空気比に近づけることができ
る。Then, after the thermoelectromotive force of the thermocouple increases according to the increase of the air ratio and exceeds the second reference voltage,
Similarly to the first embodiment, the air ratio can be made closer to the reference air ratio by reducing the fuel supply amount to the burner and increasing the air ratio by the first control.
【００２５】本第２の実施態様によれば、基本的な制御
である前記第１制御及び前記第２制御以外の制御を行う
期間が、前記第１の実施態様よりも短くてすむので、よ
り簡単な制御で、前記第１の実施態様と同様の効果を得
ることができる。According to the second embodiment, the period during which the control other than the first control and the second control, which are basic controls, is performed is shorter than that of the first embodiment. With the simple control, the same effect as in the first embodiment can be obtained.
【００２６】[0026]
【発明の実施の形態】本発明の第１の実施形態を図１〜
図４を参照して説明する。図１は本第１の実施形態の燃
焼装置に備えた熱電対の熱起電力と空気比との相関グラ
フ、図２は本第１の実施形態の燃焼装置である給湯器の
システム構成図、図３は図２に示した給湯器の空気比の
制御ブロック図、図４は図２に示した給湯器の空気比の
制御動作を示すフローチャートである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIGS.
This will be described with reference to FIG. FIG. 1 is a correlation graph between the thermoelectromotive force of a thermocouple provided in the combustion device of the first embodiment and the air ratio, FIG. 2 is a system configuration diagram of a water heater that is the combustion device of the first embodiment, FIG. 3 is a control block diagram of the air ratio of the water heater shown in FIG. 2, and FIG. 4 is a flowchart showing an operation of controlling the air ratio of the water heater shown in FIG.
【００２７】図２を参照して、本第１の実施形態の給湯
器は、使用者が設定した目標温度の湯を出湯するもので
あり、１は給湯器本体、２は給湯器本体１内に形成され
た燃焼室３に収容されたバーナ、４は燃焼室３の上方で
給湯器本体１内に設けられた熱交換器、５はバーナ２に
燃料ガスを供給するガス供給管、６は熱交換器４を通っ
て配管された給湯管、７は燃焼室３内のバーナ２に燃焼
用空気を供給する送風機、８は給湯器の作動制御を行う
コントローラ、９は出湯温の設定操作等を行うための操
作器である。燃焼室３には、バーナ２を点火するための
火花放電を生じさせる点火電極１０と、バーナ２の燃焼
状態（失火や着火の有無等）を検知する熱電対１１とが
配置されている。Referring to FIG. 2, a water heater according to the first embodiment taps out hot water having a target temperature set by a user. 1 is a water heater main body, and 2 is a water heater main body. Burner accommodated in the combustion chamber 3 formed in the above, 4 is a heat exchanger provided in the water heater body 1 above the combustion chamber 3, 5 is a gas supply pipe for supplying fuel gas to the burner 2, and 6 is A hot water supply pipe piped through the heat exchanger 4, a blower 7 for supplying combustion air to the burner 2 in the combustion chamber 3, a controller 8 for controlling the operation of the hot water supply, a setting operation 9 for setting the tap water temperature, etc. This is an operating device for performing. In the combustion chamber 3, an ignition electrode 10 for generating a spark discharge for igniting the burner 2 and a thermocouple 11 for detecting a combustion state of the burner 2 (presence or absence of misfire or ignition) are arranged.
【００２８】送風機７は、燃焼用空気の導入路１２の吸
気口１３に臨んで、導入路１２内に設けられたファン１
４と、ファン１４を回転駆動するファンモータ１５とに
より構成され、ファン１４の回転により、バーナ２の燃
焼に必要な燃焼用空気を導入路１２の吸気口１３から吸
引し、該燃焼用空気を導入路１２を介して燃焼室３に供
給する。The blower 7 faces the intake port 13 of the combustion air introduction passage 12 and is provided with a fan 1 provided in the introduction passage 12.
4 and a fan motor 15 that rotationally drives the fan 14. By the rotation of the fan 14, combustion air required for combustion of the burner 2 is sucked from the intake port 13 of the introduction path 12, and the combustion air is The fuel is supplied to the combustion chamber 3 through the introduction path 12.
【００２９】尚、ファンモータ１５には、ファンモータ
１５の回転速度を検出する回転速度センサ１６が設けら
れている。The fan motor 15 is provided with a rotation speed sensor 16 for detecting the rotation speed of the fan motor 15.
【００３０】ガス供給管５には、その上流側から順に、
ガス供給管５を開閉する主電磁弁１７と、ガス供給管５
からバーナ２に供給される燃料ガスの供給量を調節する
比例制御弁１８とが設けられている。The gas supply pipe 5 is provided in order from the upstream side.
A main solenoid valve 17 for opening and closing the gas supply pipe 5;
And a proportional control valve 18 for adjusting the amount of fuel gas supplied to the burner 2.
【００３１】給湯管６には、熱交換器４の上流側で、給
湯管６の通水量を検出する流量センサ１９と、熱交換器
４に供給される水の温度を検出する入水温センサ２０と
が設けられ、また、熱交換器４の下流側には、熱交換器
４で加熱された水の温度を検出する出湯温センサ２１が
設けられている。この場合、入水温センサ２０及び出湯
温センサ２１は、例えば感熱抵抗素子であるサーミスタ
により構成されるものである。The hot water supply pipe 6 has a flow rate sensor 19 at the upstream side of the heat exchanger 4 for detecting the amount of water flowing through the hot water supply pipe 6 and an incoming water temperature sensor 20 for detecting the temperature of water supplied to the heat exchanger 4. Is provided downstream of the heat exchanger 4, and a tapping temperature sensor 21 for detecting the temperature of water heated by the heat exchanger 4 is provided. In this case, the incoming water temperature sensor 20 and the outgoing water temperature sensor 21 are constituted by, for example, thermistors that are heat-sensitive resistance elements.
【００３２】尚、給湯管６の下流端部は、例えば、台所
等の給湯栓（図示しない）に接続される。The downstream end of the hot water supply pipe 6 is connected to a hot water tap (not shown) in, for example, a kitchen.
【００３３】操作器９には、出湯目標温度の設定を行う
温度設定スイッチ２２と、出湯目標温度や給湯器の異常
等の報知を行う表示器２３とが備えられている。The operating device 9 is provided with a temperature setting switch 22 for setting a hot water supply target temperature and a display 23 for notifying the hot water supply target temperature and an abnormality of the water heater.
【００３４】コントローラ８は、マイクロコンピュータ
やメモリ、Ｉ／Ｏユニット等の電子回路により構成され
たものであり、各センサ１６，１９，２０，２１及び熱
電対１１を介してそれぞれ検出されるファンモータ１５
の回転速度、給湯管６の通水量、入水温及び出湯温、並
びにバーナ２の燃焼状態の検出データ等に基づき、点火
電極１０や、ファンモータ１５、主電磁弁１７、比例制
御弁１８、表示器２３の作動を制御する。The controller 8 is constituted by an electronic circuit such as a microcomputer, a memory, an I / O unit, etc., and is a fan motor which is detected via each of the sensors 16, 19, 20, 21 and the thermocouple 11. Fifteen
The ignition electrode 10, the fan motor 15, the main solenoid valve 17, the proportional control valve 18, the display The operation of the vessel 23 is controlled.
【００３５】ここで、図３を参照して、コントローラ８
による給湯器の基本的作動制御の概要を説明する。Here, referring to FIG.
An outline of the basic operation control of the water heater according to the present invention will be described.
【００３６】使用者が図２に示した給湯管６の下流側の
先端に取り付けられた給湯栓（図示しない）を操作し、
流量センサ１９により給湯管６への通水が検出される
と、コントローラ８はファンモータ１５を駆動して、バ
ーナ２への燃焼用空気の供給を開始する。また、コント
ローラ８は主電磁弁１７を開弁して、バーナ２への燃料
ガスの供給を開始する。そして、この状態でコントロー
ラ８は、点火電極１０に図示しないスパーカ（高電圧発
生回路）を介して火花放電を生じさせて、バーナ２を点
火し、バーナ２の燃焼を開始する。A user operates a hot water tap (not shown) attached to a distal end on the downstream side of the hot water supply pipe 6 shown in FIG.
When the flow sensor 19 detects the passage of water through the hot water supply pipe 6, the controller 8 drives the fan motor 15 to start supplying combustion air to the burner 2. Further, the controller 8 opens the main solenoid valve 17 to start supplying fuel gas to the burner 2. Then, in this state, the controller 8 causes a spark discharge to occur in the ignition electrode 10 via a sparker (high voltage generation circuit) (not shown) to ignite the burner 2 and start burning the burner 2.
【００３７】コントローラ８は、図３に示すように、比
例弁制御手段３０と、目標燃焼量算出部３１と、モータ
駆動回路３２とを備え、バーナ２の燃焼が開始される
と、目標燃焼量算出部３１は、流量センサ１９、入水温
センサ２０及び出湯温センサ２１によりそれぞれ検出さ
れる給湯管６の通水量、入水温及び出湯温の検出データ
と、湯温設定スイッチ２２により設定された出湯温の目
標温度とに基づき、出湯温を目標温度に一致させるため
のバーナ２の目標燃焼量を時々刻々求める。As shown in FIG. 3, the controller 8 includes a proportional valve control means 30, a target combustion amount calculating section 31, and a motor drive circuit 32. When the burner 2 starts burning, the target combustion amount The calculating unit 31 detects the flow rate of water through the hot water supply pipe 6 detected by the flow rate sensor 19, the incoming water temperature sensor 20, and the outgoing water temperature sensor 21, the incoming water temperature and the outgoing water temperature, and the hot water set by the hot water temperature setting switch 22. Based on the target temperature, the target combustion amount of the burner 2 for making the hot water temperature equal to the target temperature is obtained every moment.
【００３８】そして、目標燃焼量算出部３１は、前記目
標燃焼量に応じた燃焼用空気がバーナ２に供給されるよ
うに、モータ駆動回路３２に目標回転速度を指示する。
モータ駆動回路３２は、該目標回転速度と、回転速度セ
ンサ１６により検出されるファンモータ１５の実際の回
転速度とが一致するように、ファンモータ１５に供給す
る電力を調節する。Then, the target combustion amount calculation unit 31 instructs the motor drive circuit 32 of the target rotation speed so that the combustion air according to the target combustion amount is supplied to the burner 2.
The motor drive circuit 32 adjusts the power supplied to the fan motor 15 so that the target rotation speed matches the actual rotation speed of the fan motor 15 detected by the rotation speed sensor 16.
【００３９】また、比例弁制御手段３０は、その内部に
備えた基本通電量算出部３３により、回転速度センサ１
６の検出値に応じた比例制御弁１８への通電量を算出
し、通電量決定部３４を介して比例制御弁１８に通電
し、比例制御弁１８の開度を可変することでバーナ２へ
の燃料ガスの供給量を調節する。これにより、給湯管６
の出湯温が前記設定温度に一致するようにバーナ２への
燃焼用空気の供給量と、燃料ガスの供給量とが調節され
る。The proportional valve control means 30 is provided with a basic energization amount calculating section 33 provided therein to control the rotation speed sensor 1.
6 to the burner 2 by calculating the amount of power to the proportional control valve 18 in accordance with the detection value of 6, and supplying power to the proportional control valve 18 via the amount of power determination unit 34 to vary the opening of the proportional control valve 18. Adjust the supply of fuel gas. Thereby, the hot water supply pipe 6
The supply amount of the combustion air to the burner 2 and the supply amount of the fuel gas are adjusted such that the hot water temperature of the burner matches the set temperature.
【００４０】比例弁制御手段３０は、また、ファン１４
により実際にバーナ２に供給される燃焼用空気の供給量
と、前記目標燃焼量での燃焼に必要な空気の供給量との
比である空気比（実際の供給空気量／必要空気量）を所
定の基準空気比λB に保って燃焼を行う機能を有する。
比例弁制御手段３０に備えた基準電圧算出部３５、比較
部３６、補正値算出部３７、変化検出部３８、通電量減
算部３９はこのような空気比の制御を行うためのもので
ある。The proportional valve control means 30 includes the fan 14
Thus, the air ratio (actual supply air amount / required air amount), which is the ratio of the supply amount of combustion air actually supplied to the burner 2 to the supply amount of air required for combustion at the target combustion amount, is calculated. It has a function of performing combustion while maintaining a predetermined reference air ratio λB.
The reference voltage calculation unit 35, the comparison unit 36, the correction value calculation unit 37, the change detection unit 38, and the energization amount subtraction unit 39 provided in the proportional valve control unit 30 are for controlling such an air ratio.
【００４１】以下、比例弁制御手段３０による空気比の
制御について説明する。熱電対１１の熱起電力Ｖと空気
比λとは相関関係を有し、その相関グラフは、図１に示
すように空気比λ＝１で熱起電力Ｖが最大となる、上に
凸の２次曲線となる。そして、空気比が大きいほど、燃
焼時に発生する一酸化炭素（ＣＯ）や窒素酸化物（ＮＯ
ｘ）の量が減少するため、本第１の実施形態では、基準
空気比λB を１よりも大きい１．３に設定し、空気比が
１．３の状態でバーナ２が燃焼するように制御を行う。Hereinafter, control of the air ratio by the proportional valve control means 30 will be described. There is a correlation between the thermoelectromotive force V of the thermocouple 11 and the air ratio λ, and the correlation graph shows an upwardly convex shape in which the thermoelectromotive force V is maximum at the air ratio λ = 1 as shown in FIG. It becomes a quadratic curve. As the air ratio increases, carbon monoxide (CO) and nitrogen oxides (NO
Since the amount of x) decreases, in the first embodiment, the reference air ratio λB is set to 1.3, which is larger than 1, and control is performed so that the burner 2 burns when the air ratio is 1.3. I do.
【００４２】尚、実際の制御は、空気比を直接扱わず、
空気比に対応する熱電対の熱起電力を用いて行われる。
即ち、図１のグラフにおいて、基準空気比λB に対応し
た熱起電力ＶB を基準電圧とし、熱電対１１の熱起電力
が該基準電圧ＶB ±０．２ｍＶである状態でバーナ２が
燃焼するように、制御が行われる。The actual control does not directly handle the air ratio,
This is performed using the thermoelectromotive force of the thermocouple corresponding to the air ratio.
That is, in the graph of FIG. 1, the burner 2 burns in a state where the thermoelectromotive force VB corresponding to the reference air ratio λB is set as the reference voltage and the thermoelectromotive force of the thermocouple 11 is the reference voltage VB ± 0.2 mV. Then, control is performed.
【００４３】また、熱電対１１の熱起電力Ｖと空気比λ
との相関グラフは、バーナ２の燃焼量に応じて、その最
大値と傾きが変化するため、基準電圧算出部３５は、フ
ァンモータ１５の回転速度（バーナ２の燃焼量に対応）
に応じて、基準空気比λB に対応する熱電対の基準電圧
ＶB を決定する。The thermoelectromotive force V of the thermocouple 11 and the air ratio λ
Since the maximum value and the slope of the correlation graph change in accordance with the combustion amount of the burner 2, the reference voltage calculation unit 35 determines the rotation speed of the fan motor 15 (corresponding to the combustion amount of the burner 2).
, The reference voltage VB of the thermocouple corresponding to the reference air ratio λB is determined.
【００４４】図４のフローチャートは、比例弁制御手段
３０による空気比の制御動作を示すものであり、基本通
電量算出部３３により算出された、比例制御弁１８への
基本通電量をもとに、以下の式により比例制御弁１８へ
の通電量を調節して、空気比を制御するものである。FIG. 4 is a flow chart showing the operation of controlling the air ratio by the proportional valve control means 30, and is based on the basic energizing amount to the proportional control valve 18 calculated by the basic energizing amount calculating section 33. The amount of electricity to the proportional control valve 18 is adjusted by the following equation to control the air ratio.
【００４５】通電量 ＝ 基本通電量 × 補正値α 図４を参照して、比例弁制御手段３０は、ＳＴＥＰ１で
補正値αを１（補正なし）とし、ＳＴＥＰ２で比較部３
６により、熱電対１１の熱起電力が基準電圧ＶB −０．
２ｍＶ未満であるか否かを判定する。ＳＴＥＰ２で熱電
対１１の熱起電力が基準電圧Ｖ1 −０．２ｍＶ未満でな
いと判定されたときは、ＳＴＥＰ１０に分岐し、ＳＴＥ
Ｐ１０で比較部３６により熱電対１１の熱起電力が基準
電圧ＶB＋０．２ｍＶを超えているか否かを判定する。Referring to FIG. 4, the proportional valve control means 30 sets the correction value α to 1 (no correction) in STEP 1 and the comparison unit 3 in STEP 2.
6, the thermoelectromotive force of the thermocouple 11 becomes equal to the reference voltage VB-0.
It is determined whether it is less than 2 mV. If it is determined in STEP 2 that the thermoelectromotive force of the thermocouple 11 is not less than the reference voltage V1 -0.2 mV, the flow branches to STEP 10 and the STE
At P10, the comparing unit 36 determines whether the thermoelectromotive force of the thermocouple 11 exceeds the reference voltage VB + 0.2 mV.
【００４６】ＳＴＥＰ１０で、熱電対１１の熱起電力が
基準電圧ＶB ＋０．２ｍＶを超えていないと判定された
ときはＳＴＥＰ２に分岐する。即ち熱電対１１の熱起電
力が基準電圧ＶB ±０．２ｍＶの範囲内にあるときは、
ＳＴＥＰ２，ＳＴＥＰ１０が繰り返し実行され、補正値
αは変化せず、比例制御弁３０への通電量の増減は行わ
れない。If it is determined in STEP 10 that the thermoelectromotive force of the thermocouple 11 does not exceed the reference voltage VB + 0.2 mV, the flow branches to STEP 2. That is, when the thermoelectromotive force of the thermocouple 11 is within the range of the reference voltage VB ± 0.2 mV,
STEP2 and STEP10 are repeatedly executed, the correction value α does not change, and the amount of energization to the proportional control valve 30 is not increased or decreased.
【００４７】それに対して、ＳＴＥＰ１０で、比較部３
６により熱電対１１の熱起電力が基準電圧ＶB ＋０．２
ｍＶを超えていると判定されたときには、ＳＴＥＰ１１
に進む。ＳＴＥＰ１１では、補正値算出部３７により、
補正値αから０．１が減算される。これにより、通電量
決定部３４で算出される比例電磁弁１８への通電量が減
少される。On the other hand, in STEP 10, the comparison unit 3
6, the thermoelectromotive force of the thermocouple 11 becomes equal to the reference voltage VB + 0.2.
If it is determined that the voltage exceeds mV, STEP 11
Proceed to. In STEP 11, the correction value calculation unit 37
0.1 is subtracted from the correction value α. As a result, the amount of power to the proportional solenoid valve 18 calculated by the amount-of-current determining unit 34 is reduced.
【００４８】そして、ＳＴＥＰ１２で３秒経過するのを
待ってＳＴＥＰ２に戻る。ＳＴＥＰ２で熱電対１１の熱
起電力が基準電圧ＶB −０．２ｍＶ未満でないと判定さ
れ、ＳＴＥＰ１０で熱電対１１の熱起電力が基準電圧Ｖ
B ＋０．２ｍＶを超えていると判定されたときは、再び
ＳＴＥＰ１１で補正値αから０．１が減算され、比例制
御弁１８への通電量が減少される。即ち、熱電対の熱起
電力が基準電圧ＶB ＋０．２ｍＶ以下となるまで、比例
制御弁１８への通電量を減少させる第１制御が実行され
る。Then, after waiting three seconds in STEP 12, the process returns to STEP2. In STEP 2, it is determined that the thermoelectromotive force of the thermocouple 11 is not less than the reference voltage VB -0.2 mV, and in Step 10, the thermoelectromotive force of the thermocouple 11 is
When it is determined that the difference exceeds B + 0.2 mV, 0.1 is subtracted again from the correction value α in STEP 11, and the amount of electricity supplied to the proportional control valve 18 is reduced. That is, the first control for reducing the amount of electricity supplied to the proportional control valve 18 is executed until the thermoelectromotive force of the thermocouple becomes equal to or lower than the reference voltage VB + 0.2 mV.
【００４９】一方、ＳＴＥＰ２で、熱電対１１の熱起電
力が基準電圧ＶB −０．２ｍＶ未満であると判定された
ときには、熱電対１１の熱起電力に対応する空気比が１
未満であるか、１を超えているかを判定する必要があ
る。なぜなら、図１のグラフを参照して、基準電圧ＶB
に対応する空気比は、１を超える領域にある基準空気比
λB と、１未満の領域にあるλM との２つがあり、空気
比がλB を超える領域にあるときと、空気比がλM 未満
である領域にあるときとでは、空気比の制御方向が異な
るからである。On the other hand, when it is determined in STEP 2 that the thermoelectromotive force of the thermocouple 11 is less than the reference voltage VB−0.2 mV, the air ratio corresponding to the thermoelectromotive force of the thermocouple 11 is 1
It is necessary to determine whether it is less than 1 or more than 1. Because, with reference to the graph of FIG.
There are two air ratios, namely, a reference air ratio λB in an area exceeding 1 and a λM in an area less than 1. When the air ratio is in an area exceeding λB, and when the air ratio is less than λM, This is because the control direction of the air ratio is different from when in a certain area.
【００５０】即ち、空気比が基準空気比λB を超えてい
るときは、空気比を小さくすることで、空気比を基準空
気比λB に近づけることができるが、空気比がλM 未満
であるときは、逆に、空気比を大きくすることで、空気
比を基準空気比λB に近づけることができる。That is, when the air ratio exceeds the reference air ratio λB, the air ratio can be made closer to the reference air ratio λB by reducing the air ratio, but when the air ratio is less than λM, Conversely, by increasing the air ratio, the air ratio can be made closer to the reference air ratio λB.
【００５１】そのため、比例弁制御手段３０は、ＳＴＥ
Ｐ３，ＳＴＥＰ４で、空気比がλBを超える領域にある
か、λM 未満の領域にあるかを判別する処理を行う。Ｓ
ＴＥＰ３では、補正値算出部３７、及び通電量決定部３
４により、補正値αに０．１を加算し、比例制御弁１８
への通電量を増加させる。これにより比例制御弁１８の
開度が大きくなり、バーナ２への燃料ガスの供給量が増
加するので、空気比が減少する。For this reason, the proportional valve control means 30
In P3 and STEP4, a process is performed to determine whether the air ratio is in a region exceeding .lambda.B or in a region less than .lambda.M. S
In TEP3, the correction value calculation unit 37 and the energization amount determination unit 3
4, 0.1 is added to the correction value α, and the proportional control valve 18 is added.
Increase the amount of electricity to As a result, the opening of the proportional control valve 18 increases, and the amount of fuel gas supplied to the burner 2 increases, so that the air ratio decreases.
【００５２】そして、ＳＴＥＰ４で変化検出部３８によ
り、熱電対１１の熱起電力が減少するか否かの判別を行
う。変化検出部３８により、熱電対１１の熱起電力が減
少しない（増加する）と判別されたときは、空気比は、
空気比の減少に対して熱電対１１の熱起電力が増加す
る、図１の相関グラフで傾きが負である領域、即ち空気
比が１を超える領域にあると判断できる。Then, in STEP 4, the change detector 38 determines whether the thermoelectromotive force of the thermocouple 11 decreases. When the change detection unit 38 determines that the thermoelectromotive force of the thermocouple 11 does not decrease (increases), the air ratio is:
It can be determined that the thermoelectromotive force of the thermocouple 11 increases with a decrease in the air ratio, and that the region has a negative slope in the correlation graph of FIG.
【００５３】そのため、この場合はＳＴＥＰ２０に分岐
し、３秒経過するのを待ってＳＴＥＰ２に戻る。そし
て、ＳＴＥＰ２で、熱電対１１の熱起電力が基準電圧Ｖ
B −０．２以上となるまで、ＳＴＥＰ３，ＳＴＥＰ４，
ＳＴＥＰ２０を繰り返して比例制御弁１８への通電量を
増加させ、空気比を減少させる第２制御を行う。この第
２制御により、熱電対１１の熱起電力が増加して基準電
圧ＶB に近づく。For this reason, in this case, the process branches to STEP 20 and waits for 3 seconds to return to STEP 2. Then, in STEP2, the thermoelectromotive force of the thermocouple 11 becomes equal to the reference voltage V.
Until B-0.2 or more, STEP3, STEP4,
By repeating STEP 20, the second control for increasing the amount of electricity to the proportional control valve 18 and decreasing the air ratio is performed. By this second control, the thermoelectromotive force of the thermocouple 11 increases and approaches the reference voltage VB.
【００５４】それに対して、ＳＴＥＰ４で、変化検出部
３８により、熱電対の熱起電力が減少すると判別された
ときには、空気比は、空気比の減少に対して熱電対１１
の熱起電力が減少する、図１の相関グラフで傾きが正で
ある領域、即ち空気比が１未満の領域にあると判断でき
る。On the other hand, when the change detection unit 38 determines in step 4 that the thermoelectromotive force of the thermocouple decreases, the air ratio increases with the decrease of the air ratio.
Can be determined to be in a region where the slope is positive in the correlation graph of FIG. 1, that is, a region where the air ratio is less than 1.
【００５５】そのため、この場合には、ＳＴＥＰ５に進
み、ＳＴＥＰ６で変化検出部３８により、熱電対１１の
熱起電力の増加を検知するまで、ＳＴＥＰ３０で０．５
秒経過する毎に、ＳＴＥＰ５で通電量減算部３９により
補正値αから０．１を減算して比例制御弁１８への通電
量を減少させる。これにより、比例制御弁１８の開度が
小さくなり、バーナ２への燃料ガスの供給量が減少して
空気比が大きくなり、これに対応して熱電対１１の熱起
電力が増加する。Therefore, in this case, the process proceeds to STEP5, and in STEP30, the change detection unit 38 detects the increase of the thermoelectromotive force of the thermocouple 11 by 0.5 until the change detection unit 38 detects the increase in the thermoelectromotive force.
Every time the seconds elapse, the energization amount subtraction unit 39 subtracts 0.1 from the correction value α in STEP5 to reduce the energization amount to the proportional control valve 18. As a result, the opening of the proportional control valve 18 decreases, the amount of fuel gas supplied to the burner 2 decreases, the air ratio increases, and the thermoelectromotive force of the thermocouple 11 increases correspondingly.
【００５６】そして、ＳＴＥＰ６で変化検出部３８によ
り熱電対１１の熱起電力が増加したことを検知した後
は、ＳＴＥＰ７に進み、ＳＴＥＰ８で変化検出部３８に
より、熱電対１１の熱起電力が減少したことが検知され
るまで、ＳＴＥＰ３１で０．５秒経過する毎に、ＳＴＥ
Ｐ７で通電量減算部３９により補正値αから０．１を減
算して比例制御弁１８への通電量を減少させる。After the change detecting section 38 detects in step 6 that the thermoelectromotive force of the thermocouple 11 has increased, the operation proceeds to step 7 and in step 8, the change detecting section 38 decreases the thermoelectromotive force of the thermocouple 11. Until it is detected, every time 0.5 seconds elapses in STEP31, the STE
In P7, the energization amount subtraction unit 39 subtracts 0.1 from the correction value α to reduce the energization amount to the proportional control valve 18.
【００５７】このように、比例制御弁１８への通電量を
減少させて空気比を増加させたときに、熱電対１１の熱
起電力が増加した後に減少することを検知したときは、
空気比が図１の相関グラフの空気比が１未満である領域
から、空気比が１を超える領域に移行したと判断するこ
とができる。As described above, when the amount of electricity to the proportional control valve 18 is reduced to increase the air ratio, and when it is detected that the thermoelectromotive force of the thermocouple 11 decreases after the increase,
It can be determined that the air ratio has shifted from a region where the air ratio is less than 1 in the correlation graph of FIG. 1 to a region where the air ratio exceeds 1.
【００５８】そして、空気比が１を超える領域に移行し
た後は、ＳＴＥＰ２に進み、ＳＴＥＰ２，ＳＴＥＰ１０
〜ＳＴＥＰ１２のループにより、熱電対１１の熱起電力
が基準電圧Ｖ1 ＋０．２ｍＶ以下となるまで、比例制御
弁１８への通電量を減少させる前記第１制御を行うこと
で、空気比を基準空気比λB に近づけることができる。After shifting to the region where the air ratio exceeds 1, the operation proceeds to STEP2, and STEP2, STEP10
By performing the first control to reduce the amount of electricity supplied to the proportional control valve 18 until the thermoelectromotive force of the thermocouple 11 becomes equal to or lower than the reference voltage V1 + 0.2 mV by the loop of STEP12, the air ratio is set to the reference air. Ratio λB.
【００５９】そのため、図４のフローチャートによれ
ば、空気比が図１の相関グラフ上のどの位置にあって
も、熱電対１１の熱起電力を基準空気比λB に対応した
基準電圧ＶB ±０．２ｍＶの範囲内に保つ制御がなさ
れ、バーナ２の燃焼時に発生する一酸化炭素や窒素酸化
物の生成量を抑制しながら、安定した燃焼を行うことが
できる。Therefore, according to the flowchart of FIG. 4, the thermoelectromotive force of the thermocouple 11 is changed to the reference voltage VB ± 0 corresponding to the reference air ratio λB, regardless of the air ratio at any position on the correlation graph of FIG. The control is performed so as to keep the temperature within the range of 0.2 mV, and stable combustion can be performed while suppressing the amount of carbon monoxide and nitrogen oxide generated during the combustion of the burner 2.
【００６０】次に、本発明の第２の実施形態について説
明する。本第２の実施形態の装置構成は、図２、図３に
示した前記第１の実施形態と同じであり、空気比の制御
処理方法のみが異なる。以下、図５に示したフローチャ
ートに従って、本第２の実施形態の空気比の制御処理方
法について説明する。Next, a second embodiment of the present invention will be described. The device configuration of the second embodiment is the same as that of the first embodiment shown in FIGS. 2 and 3, except for the method of controlling the air ratio. Hereinafter, an air ratio control processing method according to the second embodiment will be described with reference to the flowchart shown in FIG.
【００６１】図５を参照して、ＳＴＥＰ１〜ＳＴＥＰ４
の処理は前記第１の実施形態と共通であり、第１の実施
形態と異なるのは、ＳＴＥＰ４で、変化検出部３８によ
り、熱電対の熱起電力が減少したことから、空気比が１
未満である領域にあると判別されたときの処理である。Referring to FIG. 5, STEP 1 to STEP 4
Is the same as that of the first embodiment. The difference from the first embodiment is that in STEP 4, the change detection unit 38 reduces the thermoelectromotive force of the thermocouple.
This is the process when it is determined that the area is smaller than the area.
【００６２】図１の相関グラフから明らかなように、熱
電対１１の熱起電力が基準電圧ＶB1を超えていれば、熱
電対１１の熱起電力が基準電圧ＶB1に達するまで、比例
制御弁１８への通電量を増加させて空気比を増加させ
る、前記第１制御を行うことで、空気比を基準空気比λ
B に近づけることができる。As is apparent from the correlation graph shown in FIG. 1, if the thermoelectromotive force of the thermocouple 11 exceeds the reference voltage VB1, the proportional control valve 18 will continue until the thermoelectromotive force of the thermocouple 11 reaches the reference voltage VB1. By performing the first control of increasing the air ratio by increasing the amount of electricity to the air, the air ratio is changed to the reference air ratio λ.
B can be approached.
【００６３】そこで、本第２の実施形態では、ＳＴＥＰ
４で、変化検出部３８により、空気比が１未満の領域に
あると判別されたときには、ＳＴＥＰ５０に進み、ＳＴ
ＥＰ５１で、熱電対１１の熱起電力が、第１基準電圧Ｖ
B1よりも大きい値に設定した第２基準電圧ＶB2を超える
まで、ＳＴＥＰ５２で０．５秒経過する毎に、ＳＴＥＰ
５０で、通電量減算部３９により補正値αから０．１を
減算する。Therefore, in the second embodiment, STEP
If the change detection unit 38 determines in step 4 that the air ratio is in an area of less than 1, the process proceeds to step 50 and proceeds to step 50.
In EP51, the thermoelectromotive force of the thermocouple 11 is changed to the first reference voltage V
Until the second reference voltage VB2 set to a value greater than B1 is exceeded, every 0.5 seconds in STEP52,
In step 50, the energization amount subtraction unit 39 subtracts 0.1 from the correction value α.
【００６４】そして、ＳＴＥＰ５１で熱電対１１の熱起
電力が第２基準電圧ＶB2を超えたときは、ＳＴＥＰ２に
戻り、ＳＴＥＰ２，ＳＴＥＰ１０〜ＳＴＥＰ１２のルー
プにより前記第１制御を実行する。これにより、前記第
１の実施形態と同様、空気比が図１の相関グラフ上のど
の位置にあっても、熱電対１１の熱起電力を基準空気比
λB に対応した基準電圧ＶB ±０．２ｍＶの範囲内に保
つ制御がなされ、バーナ２の燃焼時に発生する一酸化炭
素や窒素酸化物の生成量を抑制しながら、安定した燃焼
を行うことができる。When the thermoelectromotive force of the thermocouple 11 exceeds the second reference voltage VB2 in STEP51, the process returns to STEP2, and the first control is executed by the loop of STEP2, STEP10 to STEP12. Thus, as in the first embodiment, regardless of the air ratio at any position on the correlation graph of FIG. 1, the thermoelectromotive force of the thermocouple 11 is reduced to the reference voltage VB ± 0 .0 corresponding to the reference air ratio λB. Control is performed to keep the temperature within the range of 2 mV, and stable combustion can be performed while suppressing the generation amount of carbon monoxide and nitrogen oxide generated when the burner 2 burns.
【００６５】尚、本第１、第２の実施形態において、比
例弁制御手段３０が、空気比が図１の相関グラフのλM
未満であることを検知したときは、吸気口１３の閉塞
等、装置が異常状態にあると考えられるので、表示器２
３により異常の報知を行うようにしてもよい。In the first and second embodiments, the proportional valve control means 30 determines whether the air ratio is λM in the correlation graph of FIG.
When it is detected that the pressure is less than the predetermined value, it is considered that the device is in an abnormal state, such as the blockage of the intake port 13.
The notification of the abnormality may be performed by the method described in FIG.
【００６６】また、本第１、第２の実施形態では、燃焼
装置として給湯器を例に説明したが、他の燃焼機器、例
えばガスファンヒータについても本発明の適用が可能で
ある。In the first and second embodiments, a water heater is described as an example of a combustion device. However, the present invention can be applied to other combustion equipment, for example, a gas fan heater.
【図１】空気比と熱電対の熱起電力との相関グラフ。FIG. 1 is a graph showing the correlation between the air ratio and the thermoelectromotive force of a thermocouple.
【図２】本発明の実施形態の燃焼装置である給湯器のシ
ステム構成図。FIG. 2 is a system configuration diagram of a water heater that is a combustion device according to the embodiment of the present invention.
【図３】図２の給湯器に備えたコントローラのブロック
図。FIG. 3 is a block diagram of a controller provided in the water heater of FIG. 2;
【図４】図３のコントローラの動作フローチャート。FIG. 4 is an operation flowchart of the controller of FIG. 3;
【図５】図３のコントローラの動作フローチャート。FIG. 5 is an operation flowchart of the controller of FIG. 3;
１…給湯器本体、２…バーナ、３…燃焼室、４…熱交換
器、５…ガス供給管、６…給湯管、７…送風機、８…コ
ントローラ、９…操作器、１０…点火電極、１１…熱電
対、１２…導入路、１３…吸気口、１４…ファン、１５
…ファンモータ、１６…回転速度センサ、１７…主電磁
弁、１８…比例制御弁、１９…流量センサ、２０…入水
温センサ、２１…出湯温センサ、２２…温度設定スイッ
チ、２３…表示器、３０…比例弁制御手段、３１…目標
燃焼量算出部、３２…モータ駆動回路、３３…基本通電
量算出部、３４…通電量決定部、３５…基準電圧算出
部、３６…比較部、３７…補正値算出部、３８…変化検
出部、３９…通電量減算部DESCRIPTION OF SYMBOLS 1 ... Water heater main body, 2 ... Burner, 3 ... Combustion chamber, 4 ... Heat exchanger, 5 ... Gas supply pipe, 6 ... Hot water supply pipe, 7 ... Blower, 8 ... Controller, 9 ... Operating device, 10 ... Ignition electrode, 11 thermocouple, 12 introduction path, 13 intake port, 14 fan, 15
... Fan motor, 16 ... Rotation speed sensor, 17 ... Main solenoid valve, 18 ... Proportional control valve, 19 ... Flow rate sensor, 20 ... Inlet water temperature sensor, 21 ... Outlet water temperature sensor, 22 ... Temperature setting switch, 23 ... Display Reference numeral 30: proportional valve control means, 31: target combustion amount calculation unit, 32: motor drive circuit, 33: basic energization amount calculation unit, 34: energization amount determination unit, 35: reference voltage calculation unit, 36: comparison unit, 37 ... Correction value calculation unit, 38: change detection unit, 39: energization amount subtraction unit
Claims (2)
する比例制御弁と、該バーナに燃焼用空気を供給する送
風機と、該バーナに臨んで設置され、該バーナの燃焼時
に該送風機により該バーナに供給される実際の空気量と
該バーナの燃焼に必要な空気量との比である空気比に応
じた熱起電力を発生する熱電対と、 該熱電対の熱起電力が、１以上の所定値に設定された基
準空気比に対応した基準電圧に一致するように、該熱電
対の熱起電力が該基準電圧を超えるときは前記比例制御
弁により前記バーナへの燃料供給量を減少させる第１制
御を行い、 前記熱電対の熱起電力が前記基準電圧未満であるときに
は、前記比例制御弁により前記バーナへの燃料供給量を
増加させて、前記熱電対の熱起電力が増加するか減少す
るかを判別し、増加すると判別したときは、そのまま前
記比例制御弁により前記バーナへの燃料供給量を増加さ
せる第２制御を行い、減少すると判別したときには前記
バーナへの燃料供給量の増加を中止して、前記熱電対の
熱起電力が増加した後に減少するのを検出するまで、前
記バーナへの該燃料供給量を減少させ、次いで前記第１
制御を行う比例弁制御手段とを備えたことを特徴とする
燃焼装置。1. A burner, a proportional control valve for adjusting a fuel supply amount to the burner, a blower for supplying combustion air to the burner, and a blower installed facing the burner, the blower being used for burning the burner. A thermocouple that generates a thermoelectromotive force according to an air ratio which is a ratio of an actual air amount supplied to the burner to an air amount required for combustion of the burner, and a thermoelectromotive force of the thermocouple is: When the thermoelectromotive force of the thermocouple exceeds the reference voltage so as to match a reference voltage corresponding to a reference air ratio set to one or more predetermined values, a fuel supply amount to the burner by the proportional control valve. When the thermoelectromotive force of the thermocouple is less than the reference voltage, the proportional control valve increases the fuel supply amount to the burner, and the thermoelectromotive force of the thermocouple is reduced. Determine whether to increase or decrease and increase When it is determined, the second control for increasing the fuel supply amount to the burner is performed by the proportional control valve as it is, and when it is determined that the fuel supply amount decreases, the increase in the fuel supply amount to the burner is stopped, and the thermocouple is stopped. The fuel supply to the burner is reduced until the thermoelectromotive force is detected to decrease after increasing, and then the first
A combustion device comprising: a proportional valve control means for performing control.
する比例制御弁と、該バーナに燃焼用空気を供給する送
風機と、該バーナに臨んで設置され、該バーナの燃焼時
に該送風機により該バーナに供給される実際の空気量と
該バーナの燃焼に必要な空気量との比である空気比に応
じた熱起電力を発生する熱電対と、 該熱電対の熱起電力が、１以上の所定値に設定された基
準空気比に対応した第１基準電圧に一致するように、該
熱電対の熱起電力が該第１基準電圧を超えるときは前記
比例制御弁により前記バーナへの燃料供給量を減少させ
る第１制御を行い、 前記熱電対の熱起電力が前記第１基準電圧未満であると
きには、前記比例制御弁により前記バーナへの燃料供給
量を増加させて、前記熱電対の熱起電力が増加するか減
少するかを判別し、増加すると判別したときは、そのま
ま前記比例制御弁により前記バーナへの燃料供給量を増
加させる第２制御を行い、減少すると判別したときには
前記バーナへの燃料供給量の増加を中止して、前記熱電
対の熱起電力が前記第１基準電圧よりも高い所定の第２
基準電圧以上となるまで、前記バーナへの該燃料供給量
を減少させた後に前記第１制御を行う比例弁制御手段と
を備えたことを特徴とする燃焼装置。2. A burner, a proportional control valve for adjusting an amount of fuel supplied to the burner, a blower for supplying combustion air to the burner, and a blower installed facing the burner, the blower being used for burning the burner. A thermocouple that generates a thermoelectromotive force according to an air ratio which is a ratio of an actual air amount supplied to the burner to an air amount required for combustion of the burner, and a thermoelectromotive force of the thermocouple is: When the thermoelectromotive force of the thermocouple exceeds the first reference voltage so as to match the first reference voltage corresponding to the reference air ratio set to at least one predetermined value, the proportional control valve causes the proportional control valve to control the burner. Performing a first control to decrease the fuel supply amount of the thermocouple, and when the thermoelectromotive force of the thermocouple is less than the first reference voltage, the proportional control valve increases the fuel supply amount to the burner, thereby increasing the thermoelectric power. Determine if paired thermoelectromotive force increases or decreases When it is determined to increase, the second control for increasing the fuel supply amount to the burner is performed by the proportional control valve as it is, and when it is determined to decrease, the increase in the fuel supply amount to the burner is stopped, A predetermined second voltage having a thermoelectromotive force of a thermocouple higher than the first reference voltage;
A combustion apparatus comprising: a proportional valve control unit that performs the first control after reducing the fuel supply amount to the burner until the fuel supply amount reaches a reference voltage or more.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12735497A JP3307560B2 (en) | 1997-05-16 | 1997-05-16 | Combustion equipment |
| KR1019980017579A KR100313781B1 (en) | 1997-05-16 | 1998-05-15 | Combustion apparatus and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12735497A JP3307560B2 (en) | 1997-05-16 | 1997-05-16 | Combustion equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10318534A JPH10318534A (en) | 1998-12-04 |
| JP3307560B2 true JP3307560B2 (en) | 2002-07-24 |
Family
ID=14957869
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12735497A Expired - Fee Related JP3307560B2 (en) | 1997-05-16 | 1997-05-16 | Combustion equipment |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP3307560B2 (en) |
| KR (1) | KR100313781B1 (en) |
-
1997
- 1997-05-16 JP JP12735497A patent/JP3307560B2/en not_active Expired - Fee Related
-
1998
- 1998-05-15 KR KR1019980017579A patent/KR100313781B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10318534A (en) | 1998-12-04 |
| KR100313781B1 (en) | 2001-12-28 |
| KR19980087111A (en) | 1998-12-05 |
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