JPH0437332B2 - - Google Patents
Info
- Publication number
- JPH0437332B2 JPH0437332B2 JP60139425A JP13942585A JPH0437332B2 JP H0437332 B2 JPH0437332 B2 JP H0437332B2 JP 60139425 A JP60139425 A JP 60139425A JP 13942585 A JP13942585 A JP 13942585A JP H0437332 B2 JPH0437332 B2 JP H0437332B2
- Authority
- JP
- Japan
- Prior art keywords
- flame
- air
- current
- fuel ratio
- flame rod
- 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 - Lifetime
Links
- 239000000446 fuel Substances 0.000 claims description 35
- 238000001514 detection method Methods 0.000 claims description 19
- 238000002485 combustion reaction Methods 0.000 claims description 8
- 238000005259 measurement Methods 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000005856 abnormality Effects 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 239000000567 combustion gas Substances 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N5/00—Systems for controlling combustion
- F23N5/02—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium
- F23N5/12—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using ionisation-sensitive elements, i.e. flame rods
- F23N5/123—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using ionisation-sensitive elements, i.e. flame rods using electronic means
-
- 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
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2225/00—Measuring
- F23N2225/26—Measuring humidity
- F23N2225/30—Measuring humidity measuring lambda
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N2229/00—Flame sensors
- F23N2229/16—Flame sensors using two or more of the same types of flame sensor
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Combustion (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明はガス、石油等の燃焼装置の空燃比を検
出する装置に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for detecting the air-fuel ratio of a combustion device for gas, oil, etc.
従来の技術
従来の空燃比検出装置は第７図に示すように、
燃焼用混合気体の流出するバーナ１と、このバー
ナ１から形成される炎の外炎に触れる位置に設置
したフレームロツド２とを電源３と電流計４とを
直列に接続した回路に組込んだ構成であり、バー
ナ１から流出する燃焼用混合気体が着火して炎を
形成するのであるが、この炎に電導性がある為、
前記電流計４の回路が形成されて、この回路に電
流が流れる。この電流の大きさは炎内のイオン濃
度、即ち燃料と空気との混合比（以後、空燃比と
記す）によつて決定されるのであるから電流計４
の電流値を読み取る事によつて空燃比を知る事が
できるというものである。（例えば、特公昭46−
36947号公報）又、例えば特開昭51−117341号公
報に記載された装置のようにフレームロツドを２
本使い、一方を空気過剰検出、他方を燃料過剰検
出として用いた例もある。Conventional technology As shown in Fig. 7, a conventional air-fuel ratio detection device
A configuration in which a burner 1 from which a combustion gas mixture flows out and a flame rod 2 installed in a position where it touches the outer flame of the flame formed from this burner 1 are incorporated into a circuit in which a power source 3 and an ammeter 4 are connected in series. The combustion gas mixture flowing out of burner 1 ignites and forms a flame, but since this flame has electrical conductivity,
A circuit for the ammeter 4 is formed, and a current flows through this circuit. The magnitude of this current is determined by the ion concentration in the flame, that is, the mixture ratio of fuel and air (hereinafter referred to as air-fuel ratio), so the ammeter 4
The air-fuel ratio can be determined by reading the current value. (For example, Tokuko Sho 46-
36947) Also, for example, as in the device described in JP-A-51-117341, two frame rods are
In some cases, one is used to detect excess air and the other is used to detect excess fuel.
発明が解決しようとする問題点
しかしながら、炎イオン電流と空燃比の関係は
第８図に示す様に空燃比Ｐ＝POでイオン電流Ifは
ピーク値If＝IfOとなり、１対１の関数にならない
ことが知られており、上記前者の様な従来の構成
では、If＝If1のときにＰ＝P1なのかＰ＝P2なのか
判別できないという問題点を有していた。又、上
記後者の様な従来の構成では空気過剰による燃焼
異常、燃料過剰による燃焼異常、又は正常状態の
識別はできるが、正常、異常の程度を定量的に検
出する、即ち空燃比を全域にわたつて検出するこ
とが困難であるという問題点を有していた。Problems to be Solved by the Invention However, as shown in Figure 8, the relationship between the flame ion current and the air-fuel ratio is such that when the air-fuel ratio P = P O , the ion current I f has a peak value I f = I fO , and it is 1:1. It is known that it is not a function of Ta. In addition, in conventional configurations such as the latter, it is possible to distinguish between combustion abnormalities due to excess air, combustion abnormalities due to excess fuel, or normal conditions, but it is not possible to quantitatively detect the degree of normality or abnormality, that is, to determine the air-fuel ratio over the entire range. The problem is that it is difficult to detect it across the board.
本発明はかかる従来の問題点を解消するもの
で、空燃比を全域にわたり検出し、燃焼の正常、
異常を定量的に検出することを目的とする。 The present invention solves these conventional problems by detecting the air-fuel ratio over the entire range and determining whether combustion is normal or not.
The purpose is to quantitatively detect abnormalities.
問題点を解決するための手段
上記問題点を解決するために本発明の空燃比検
出装置は、一対の電極で構成され燃焼火炎中のイ
オン電流対空燃比特性が異なる箇所に挿入された
複数のフレームロツドセンサと、前記各フレーム
ロツドセンサの電極間に共通の電圧を印加する１
個の電源と、前記各フレームロツドセンサと直列
に接続された炎電流検出抵抗と、前記各検出抵抗
に流れる電流を計測する電流計測回路と、前記各
電流計測回路で計測した電流の相対値を演算する
割算手段を有する構成としたものである。Means for Solving the Problems In order to solve the above problems, the air-fuel ratio detection device of the present invention comprises a plurality of frames each of which is composed of a pair of electrodes and is inserted into a combustion flame at a location where the ionic current vs. air-fuel ratio characteristics are different. 1. Applying a common voltage between the electrodes of the rod sensor and each of the frame rod sensors.
a flame current detection resistor connected in series with each of the flame rod sensors, a current measurement circuit that measures the current flowing through each of the detection resistors, and a relative value of the current measured by each of the current measurement circuits. The structure includes a division means for calculating .
作 用
本発明は上記した構成によつて、イオン電流の
相対値を演算することにより相対値と空燃比が１
対１の関数になるので相対値により空燃比が検出
可能という作用を有する。Effect The present invention has the above-described configuration, and by calculating the relative value of the ion current, the relative value and the air-fuel ratio can be adjusted to 1.
Since it is a one-to-one function, it has the effect that the air-fuel ratio can be detected by a relative value.
実施例
以下、本発明の実施例を添付図面にもとづいて
説明する。なお、実施例の説明にあたつては第７
図と同一部分には便宜上同一符号を付した。第１
図において１はバーナーで、このバーナー１から
形成される火炎に２本のフレームロツド２ａと２
ｂが挿入され、一方の電極をバーナ、他方の電極
をフレームロツドとした２個のフレームロツドセ
ンサ５ａ，５ｂを構成している。３は電源でここ
では直流電源を使用しており、６ａ，６ｂは炎電
流検出用抵抗であり、フレームロツドセンサ５
ａ，５ｂと炎電流検出用抵抗６ａ，６ｂの接続点
の電位は電流計測回路７ａ，７ｂに入力されフレ
ームロツドセンサ５ａ，５ｂに流れる炎電流Ifa、
Ifbを検出している。演算増幅器８ａ，８ｂはボ
ルテージフオロア回路を構成しており炎電流Ifa、
Ifbに比例した出力電圧に変換される。演算増幅
器９ａ、抵抗１０ａ，１１ａ、および演算増幅器
９ｂ、抵抗１０ｂ，１１ｂはそれぞれ反転増幅回
路を構成し抵抗１２，１３により分圧された基準
電位に対して反転増幅している。１４は割算予段
で、演算増幅器１５ａ，１５ｂ、トランジスタ１
６ａ，１６ｂ、ダイオード１７ａ，１７ｂ、抵抗
１８ａ，１８ｂ，１９によりそれぞれ構成された
２個の対数変換回路と、演算増幅器２０、抵抗２
１，２２，２３，２４で構成された差動増幅器に
より構成され、log Ifb／Lfaに比例した出力を得
るために対数変換回路と差動増幅回路の組み合わ
せでlog Ifb−log lfaの演算を行つている。火炎
中でフレームフロツドの挿入箇所によりイオン電
流対空燃比特性を変えることが可能であることは
知られており、フレームロツドセンサ５ａ，５ｂ
のイオン電流対空燃比特性を第２図に示す。イオ
ン電流Ifa、Ifbがピークとなる空燃比はそれぞれ
Ｐ＝Pa、Ｐ＝Pbと違つた点になる。電流検出回
路７ａ，７ｂの出力電圧V7a、V7bの特性は第３
図に示す様にイオン電流Ifa、Ifbに比例したもの
となる。電流検出回路７ａ，７ｂの出力電圧
V7a、V7bは割算予段１４に入力する。２個の対
数変換回路の出力電圧Vla、VlbはV7a、V7bの対数
に比例するので特性は第４図に示す様になる。差
動増幅回路の出力電圧VputはVlb−Vlaに比例する
ので空燃比特性は第５図の様に１対１に対応する
関数となる。なお、第５図上P1、P2は第８図の
P1、P2に相当するものである。これでVputを計測
することにより空燃比を検出することが可能とな
るのである。Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In addition, when explaining the example, please refer to the seventh
For convenience, the same parts as those in the figure are given the same reference numerals. 1st
In the figure, 1 is a burner, and two flame rods 2a and 2 are attached to the flame formed from this burner 1.
b is inserted to form two flame rod sensors 5a and 5b, one electrode of which is a burner and the other electrode of which is a flame rod. 3 is a power source, in which a DC power source is used; 6a and 6b are resistances for flame current detection; and flame rod sensor 5.
The potential at the connection point between a, 5b and the flame current detection resistors 6a, 6b is input to the current measuring circuits 7a, 7b, and the flame current I fa flows to the flame rod sensors 5a, 5b.
I am detecting fb . The operational amplifiers 8a and 8b constitute a voltage follower circuit, and the flame current I fa ,
I is converted to an output voltage proportional to fb . The operational amplifier 9a, the resistors 10a and 11a, and the operational amplifier 9b and the resistors 10b and 11b each constitute an inverting amplifier circuit, and perform inverting amplification with respect to the reference potential divided by the resistors 12 and 13. 14 is a division budget stage, which includes operational amplifiers 15a and 15b, and transistor 1.
6a, 16b, diodes 17a, 17b, resistors 18a, 18b, 19, respectively, two logarithmic conversion circuits, an operational amplifier 20, and a resistor 2.
It is composed of a differential amplifier consisting of 1, 22, 23, and 24, and calculates log Ifb - log lfa by a combination of a logarithmic conversion circuit and a differential amplifier circuit to obtain an output proportional to log Ifb / Lfa. It's on. It is known that it is possible to change the ion current versus air-fuel ratio characteristics depending on the insertion point of the flame rod in a flame, and the flame rod sensors 5a and 5b
Figure 2 shows the ion current vs. air-fuel ratio characteristics of . The air-fuel ratios at which the ion currents I fa and I fb reach their peaks are at different points, P=P a and P=P b , respectively. The characteristics of the output voltages V 7a and V 7b of the current detection circuits 7a and 7b are as follows.
As shown in the figure, it is proportional to the ion currents I fa and I fb . Output voltage of current detection circuits 7a and 7b
V 7a and V 7b are input to the division budget stage 14. Since the output voltages V la and V lb of the two logarithmic conversion circuits are proportional to the logarithms of V 7a and V 7b , the characteristics are as shown in FIG. Since the output voltage Vput of the differential amplifier circuit is proportional to Vlb - Vla , the air-fuel ratio characteristic becomes a function corresponding to one to one as shown in FIG. In addition, P 1 and P 2 on the top of Figure 5 are the same as in Figure 8.
This corresponds to P 1 and P 2 . This makes it possible to detect the air-fuel ratio by measuring V put .
次に本発明の別の実施例を第６図に示す。前記
実施例と相違する点は電源３に交流電源を使用し
ている点である。抵抗２５ａ，２５ｂの両端の電
圧はコンデンサ２６ａ，２６ｂと抵抗２７ａ，２
７ｂでそれぞれなる積分回路で、整流作用により
発生した直流分のみが積分され、積分回路の出力
電位は電流計測回路７ａ，７ｂに入力し、以下前
記実施例と同様の動作でVputを計測することによ
り空燃比を検出することが可能となる。以上の実
施例では割算手段を対数変換回路と差動増幅回路
で構成してlag Ifb−log／lfaの演算を行わせてい
るが、Ａ／Ｄ変換回路によりデイジタル値に変換
してマイクロコンピユータ等のプログラムで構成
してIfb／Ifaの演算を行つてもよい。又、第２図
ではイオン電流Ifa、Ifbのピーク値が等しいが、
ピーク値が違つても同様の作用を有するものであ
り、フレームロツドセンサを３個以上使用してよ
り精度の高い検出を行なうことも可能である。
又、複数のフレームロツドセンサをパイロツトバ
ーナ等別バーナの火炎に挿入しても実現可能であ
る。 Next, another embodiment of the present invention is shown in FIG. The difference from the previous embodiment is that an AC power source is used as the power source 3. The voltage across the resistors 25a, 25b is the voltage across the capacitors 26a, 26b and the resistors 27a, 2.
At 7b, each integrating circuit integrates only the DC component generated by the rectifying action, and the output potential of the integrating circuit is input to current measuring circuits 7a and 7b, and V put is then measured in the same manner as in the above embodiment. This makes it possible to detect the air-fuel ratio. In the above embodiment, the dividing means is configured with a logarithmic conversion circuit and a differential amplifier circuit to perform the calculation of lag Ifb-log/lfa. Ifb/Ifa calculations may be performed using a program such as the following. Also, in Fig. 2, the peak values of the ion currents I fa and I fb are equal, but
Even if the peak values are different, they have the same effect, and it is also possible to perform more accurate detection by using three or more flame rod sensors.
It is also possible to insert a plurality of flame rod sensors into the flame of a separate burner such as a pilot burner.
発明の効果
以上のように本発明の空燃比検出装置によれば
次の効果が得られる。Effects of the Invention As described above, the air-fuel ratio detection device of the present invention provides the following effects.
(1) 複数のフレームロツドセンサによりイオン電
流の相対値で空燃比を検出しているので、１対
１に対応する関数として空燃比を全域にわたり
検出可能であり、正常燃焼、異常燃焼の程度を
定量的に検出できる効果がある。(1) Since the air-fuel ratio is detected using the relative value of the ion current using multiple flame rod sensors, it is possible to detect the air-fuel ratio over the entire range as a function with a one-to-one correspondence, and it is possible to detect the degree of normal combustion and abnormal combustion. It has the effect of quantitatively detecting
(2) 複数のフレームロツドセンサに１個の電源で
共通の電圧を印加しているので、電源電圧が変
動していイオン電流の絶対値が変動しても相対
値は変動しないので信頼性の高い空燃比検出装
置を提供できるという効果がある。(2) Since a common voltage is applied to multiple flame rod sensors by one power supply, even if the power supply voltage fluctuates and the absolute value of the ion current changes, the relative value does not change, which improves reliability. This has the effect of providing a high air-fuel ratio detection device.
第１図は本発明の一実施例を示す空燃比検出装
置の回路図、第２図はイオン電流の空燃比特性
図、第３図は電流検出回路出力電圧の空燃比特性
図、第４図は対数変換回路出力電圧の空燃比特性
図、第５図は空燃比検出部出力電圧の空燃比特性
図、第６図は本発明の他の実施例を示す回路図、
第７図は従来例の空燃比検出装置のシステム図、
第８図はイオン電流の空燃比特性図である。
１……バーナ（フレームロツドセンサの電極）、
２ａ，２ｂ……フレームロツド（フレームロツド
センサの電極）、３……電源、５ａ，５ｂ……フ
レームロツドセンサ、６ａ，６ｂ……炎電流検出
抵抗、７ａ，７ｂ……電流計測回路、１４……割
算手段。
Fig. 1 is a circuit diagram of an air-fuel ratio detection device showing an embodiment of the present invention, Fig. 2 is an air-fuel ratio characteristic diagram of ion current, Fig. 3 is an air-fuel ratio characteristic diagram of current detection circuit output voltage, and Fig. 4 is an air-fuel ratio characteristic diagram of the logarithmic conversion circuit output voltage, FIG. 5 is an air-fuel ratio characteristic diagram of the air-fuel ratio detection unit output voltage, and FIG. 6 is a circuit diagram showing another embodiment of the present invention.
Figure 7 is a system diagram of a conventional air-fuel ratio detection device.
FIG. 8 is an air-fuel ratio characteristic diagram of ion current. 1...Burner (flame rod sensor electrode),
2a, 2b... Flame rod (electrode of flame rod sensor), 3... Power supply, 5a, 5b... Flame rod sensor, 6a, 6b... Flame current detection resistor, 7a, 7b... Current measurement circuit, 14 ...Division means.
Claims (1)
流対空燃比特性が異なる箇所に挿入された複数の
フレームロツドセンサと、前記各フレームロツド
センサの電極間に共通の電圧を印加する１個の電
源と、前記各フレームロツドセンサと直列に接続
された炎電流検出抵抗と、前記各検出抵抗に流れ
る電流を計測する電流計測回路と、前記各電流計
測回路で計測した電流の相対値を演算する割算手
段を有する構成の空燃比検出装置。1 A plurality of flame rod sensors each consisting of a pair of electrodes and inserted at locations with different ionic current versus air-fuel ratio characteristics in a combustion flame, and one flame rod sensor that applies a common voltage between the electrodes of each of the flame rod sensors. A power source, a flame current detection resistor connected in series with each of the flame rod sensors, a current measurement circuit that measures the current flowing through each of the detection resistors, and a calculation of the relative value of the current measured by each of the current measurement circuits. An air-fuel ratio detection device configured to have a dividing means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60139425A JPS62725A (en) | 1985-06-26 | 1985-06-26 | Air-fuel ratio detecting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60139425A JPS62725A (en) | 1985-06-26 | 1985-06-26 | Air-fuel ratio detecting device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62725A JPS62725A (en) | 1987-01-06 |
| JPH0437332B2 true JPH0437332B2 (en) | 1992-06-19 |
Family
ID=15244899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60139425A Granted JPS62725A (en) | 1985-06-26 | 1985-06-26 | Air-fuel ratio detecting device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62725A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2805029B1 (en) * | 2000-02-15 | 2002-07-19 | Brandt Cooking | GAS BURNER CONTROL DEVICE |
| ITAN20020038A1 (en) * | 2002-08-05 | 2004-02-06 | Merloni Termosanitari Spa Ora Ariston Thermo Spa | LAMBDA VIRTUAL SENSOR COMBUSTION CONTROL SYSTEM. |
| JP4997900B2 (en) * | 2006-09-29 | 2012-08-08 | 株式会社ノーリツ | Flame current detection device and combustion device |
| JP5274442B2 (en) * | 2009-12-22 | 2013-08-28 | 株式会社パロマ | Combustion device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51117341A (en) * | 1975-04-07 | 1976-10-15 | Mitsubishi Electric Corp | Combustion apparatus |
-
1985
- 1985-06-26 JP JP60139425A patent/JPS62725A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51117341A (en) * | 1975-04-07 | 1976-10-15 | Mitsubishi Electric Corp | Combustion apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62725A (en) | 1987-01-06 |
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