JPH06213055A - Air-fuel ratio controller of gas engine - Google Patents
Air-fuel ratio controller of gas engineInfo
- Publication number
- JPH06213055A JPH06213055A JP4325297A JP32529792A JPH06213055A JP H06213055 A JPH06213055 A JP H06213055A JP 4325297 A JP4325297 A JP 4325297A JP 32529792 A JP32529792 A JP 32529792A JP H06213055 A JPH06213055 A JP H06213055A
- Authority
- JP
- Japan
- Prior art keywords
- air
- fuel ratio
- adjusting means
- output
- ratio adjusting
- 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.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 28
- 239000007789 gas Substances 0.000 claims abstract description 35
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 33
- 239000001301 oxygen Substances 0.000 claims abstract description 33
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 33
- 238000000034 method Methods 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 4
- 239000002737 fuel gas Substances 0.000 description 2
- 239000000567 combustion gas Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Output Control And Ontrol Of Special Type Engine (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ガスエンジンの空燃比
制御方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas engine air-fuel ratio control method.
【０００２】[0002]
【従来の技術】稀薄燃焼ガスエンジンでは、ＮＯX を低
減するために、稀薄な空燃比を採用している。実用化さ
れている稀薄燃焼ガスエンジンでは、エンジン出力、エ
ンジン回転数、吸気圧力、吸気温度、インタクーラ水
温、又は、その一部を計測し、目標空燃比を決定してい
る。BACKGROUND OF THE INVENTION lean combustion gas engine, in order to reduce NO X, employs a dilute air-fuel ratio. In a lean-burn gas engine that has been put into practical use, the target air-fuel ratio is determined by measuring engine output, engine speed, intake pressure, intake temperature, intercooler water temperature, or part thereof.
【０００３】[0003]
【発明が解決しようとする課題】しかし、エンジンの排
出ＮＯX 濃度は、大気の湿度の影響を大きく受ける。す
なわち、図５に示すように例えば酸素濃度７％の特性Ｃ
において、ＮＯX 濃度は、例えば湿度５０％で１５００
ｐｐｍであるが、湿度１０％では３２００ｐｐｍと非常
に大きく変化する。However, the exhaust NO x concentration of the engine is greatly affected by atmospheric humidity. That is, as shown in FIG. 5, for example, the characteristic C with an oxygen concentration of 7%
In, NO X concentration, for example 50% humidity 1500
Although it is ppm, when humidity is 10%, it greatly changes to 3200 ppm.
【０００４】本発明は、湿度が変化しても安定的にＮＯ
X を低減することができるガスエンジンの空燃比制御方
法を提供することを目的としている。According to the present invention, NO is stable even if the humidity changes.
An object of the present invention is to provide a gas engine air-fuel ratio control method capable of reducing X.
【０００５】[0005]
【課題を解決するための手段】本発明による方法は、エ
ンジン出力値と大気湿度とを取込んで排気中の酸素濃度
目標値を演算し、その演算した排気中の酸素濃度目標値
からリーン酸素センサの出力目標値を演算し、この演算
したリーン酸素センサの出力目標値から空燃比調節手段
の設定値を演算し且つその演算結果通りに該空燃比調節
手段を設定し、リーン酸素センサの出力値を取込んで前
記目標値と比較し、両者が等しくなるように空燃比調節
手段を制御している。According to the method of the present invention, an engine output value and atmospheric humidity are taken in to calculate an oxygen concentration target value in exhaust gas, and lean oxygen is calculated from the calculated oxygen concentration target value in exhaust gas. The output target value of the sensor is calculated, the set value of the air-fuel ratio adjusting means is calculated from the calculated output target value of the lean oxygen sensor, and the air-fuel ratio adjusting means is set according to the calculation result, and the output of the lean oxygen sensor is calculated. The value is fetched and compared with the target value, and the air-fuel ratio adjusting means is controlled so that they become equal.
【０００６】本発明の実施に際して、前記空燃比調節手
段はガスバイパス弁であるか、或いは空気バイパス弁で
あるのが好ましい。また、ガスのバイパス回路を設けず
に、直接に（メインとなる）ガス量を制御しても良い。In implementing the present invention, the air-fuel ratio adjusting means is preferably a gas bypass valve or an air bypass valve. Further, the gas amount (main) may be directly controlled without providing a gas bypass circuit.
【０００７】ここで、上記制御は、パーソナルコンピュ
ータで構成された制御ユニットで行い、その制御ユニッ
トに、リーン酸素センサ、ガスバイパス弁、エンジン出
力センサ及びエアフィルタに設けた湿度計を接続するの
が好ましい。Here, the above-mentioned control is performed by a control unit composed of a personal computer, and a lean oxygen sensor, a gas bypass valve, an engine output sensor and a hygrometer provided in an air filter are connected to the control unit. preferable.
【０００８】[0008]
【作用】本発明においては、湿度をファクタにして排気
中の目標酸素濃度を求め、その目標酸素濃度からリーン
酸素センサの目標出力値を介して、空燃比調節手段の設
定値（例えばガスバイパス弁の開度目標値）を求めて設
定し、リーン酸素センサの出力値が目標出力値に等しく
なるように、空燃比調節手段を制御する。ここで、空燃
比調節手段がガスバイパス弁である場合には、ガスバイ
パス弁の弁開度を制御する。In the present invention, the target oxygen concentration in the exhaust gas is obtained by using the humidity as a factor, and the set value of the air-fuel ratio adjusting means (for example, the gas bypass valve) is obtained from the target oxygen concentration via the target output value of the lean oxygen sensor. Then, the air-fuel ratio adjusting means is controlled so that the output value of the lean oxygen sensor becomes equal to the target output value. Here, when the air-fuel ratio adjusting means is a gas bypass valve, the valve opening degree of the gas bypass valve is controlled.
【０００９】[0009]
【実施例】以下図面を参照して本発明の実施例を説明す
る。Embodiments of the present invention will be described below with reference to the drawings.
【００１０】図１には、本発明を実施する装置の一例が
示されている。ガスエンジン１の吸気通路２には、吸入
空気Ａのエアフィルタ３、ミキサ４、ターボチャージャ
５、インタクーラ６及びスロットル７が直列に設けられ
ている。そのミキサ４には、燃料ガスＧの供給管８が接
続され、インタクーラ６とスロットル７との間は、ガス
バイパス弁９（空燃比調節手段）を備えたバイパス管８
ａにより供給管８に接続されている。FIG. 1 shows an example of an apparatus for carrying out the present invention. In the intake passage 2 of the gas engine 1, an air filter 3, a mixer 4, a turbocharger 5, an intercooler 6, and a throttle 7 for intake air A are provided in series. A fuel gas G supply pipe 8 is connected to the mixer 4, and a bypass pipe 8 provided with a gas bypass valve 9 (air-fuel ratio adjusting means) between the intercooler 6 and the throttle 7.
It is connected to the supply pipe 8 by a.
【００１１】他方、排気通路１０には、リーン酸素セン
サ１１が設けられ、そのセンサ１１はガスバイパス弁９
と共に、パーソナルコンピュータで構成された制御ユニ
ット１２にそれぞれ接続されている。そして、この制御
ユニット１２には、エンジン出力センサ１３と、エアフ
ィルタ３の一部に設けられた湿度計１４とがそれぞれ接
続されている。On the other hand, a lean oxygen sensor 11 is provided in the exhaust passage 10, and the sensor 11 is a gas bypass valve 9.
Together, they are respectively connected to the control unit 12 composed of a personal computer. The engine output sensor 13 and the hygrometer 14 provided in a part of the air filter 3 are connected to the control unit 12.
【００１２】制御に際し制御ユニット１２は図２に示す
ように、エンジン出力センサ１３からエンジン出力Ｐを
取込み（ステップＳ１）、湿度計１４から大気湿度Ｈを
取込み（ステップＳ２）、これらのエンジン出力Ｐ及び
大気湿度Ｈから図３及び式１により排気中の酸素濃度の
酸素濃度目標値Ｏ20を演算する（ステップＳ３）。な
お、図３の欄内数字は、ＮＯX の目標値に対応する排ガ
ス中の酸素濃度を示している。例えばエンジン出力１０
０％で、大気湿度１００％では、排気中の酸素濃度８％
で、ＮＯX は２００ｐｐｍとなる。なお、Ｏ2i,jは実験
で決定しておく。In the control, the control unit 12 takes in the engine output P from the engine output sensor 13 (step S1) and the atmospheric humidity H from the hygrometer 14 (step S2) as shown in FIG. Then, the oxygen concentration target value O 20 of the oxygen concentration in the exhaust gas is calculated from the atmospheric humidity H according to FIG. 3 and Equation 1 (step S3). The numbers in the columns of FIG. 3 indicate the oxygen concentration in the exhaust gas corresponding to the target value of NO X. For example, engine output 10
0%, 100% atmospheric humidity, 8% oxygen concentration in the exhaust
Therefore, NO X becomes 200 ppm. Note that O 2i, j has been experimentally determined.
【００１３】 次いで、図４により酸素濃度目標値Ｏ20からリーン酸素
センサ１１の出力Ｌのリーンセンサ出力目標値Ｌ0 を演
算し（ステップＳ４）、これに基づきガスバイパス弁９
の開度Ｍのバイパス弁開度目標値Ｍ0 を演算する（ステ
ップＳ５）。そこで、ガスバイパス弁９に制御信号を出
力し、開度Ｍをバイパス弁開度目標値Ｍ0 にする（ステ
ップＳ６）、次いで、リーン酸素センサ１１からリーン
センサ出力Ｌを取込み（ステップＳ７）、その出力Ｌが
リーンセンサ出力目標値Ｌ0 に等しいか否かを判定する
（ステップＳ８）。ＹＥＳだったら、制御を終り、ＮＯ
の場合は、ステップＳ５に戻る。そこで、センサ出力Ｌ
に対応したガスバイパス弁９の目標値Ｍ0 を演算し、弁
開度を変えることによりリーンセンサ出力すなわち空燃
比を補正する。[0013] Next, the lean sensor output target value L 0 of the output L of the lean oxygen sensor 11 is calculated from the oxygen concentration target value O 20 according to FIG. 4 (step S4), and the gas bypass valve 9
The bypass valve opening target value M 0 of the opening M of is calculated (step S5). Therefore, a control signal is output to the gas bypass valve 9 to set the opening M to the bypass valve opening target value M 0 (step S6), and then the lean sensor output L is taken in from the lean oxygen sensor 11 (step S7). It is determined whether the output L is equal to the lean sensor output target value L 0 (step S8). If YES, end control and NO
In case of, it returns to step S5. Therefore, the sensor output L
The target value M 0 of the gas bypass valve 9 corresponding to is calculated and the valve opening is changed to correct the lean sensor output, that is, the air-fuel ratio.
【００１４】[0014]
【発明の効果】以上説明したように本発明によれば、湿
度により目標空燃比を補正して安定的にＮＯx を低減す
ることができる。As described above, according to the present invention, the target air-fuel ratio can be corrected by the humidity to stably reduce NOx.
【図１】本発明を実施する装置の一例を示す全体構成
図。FIG. 1 is an overall configuration diagram showing an example of an apparatus for implementing the present invention.
【図２】制御フローチャート図。FIG. 2 is a control flowchart.
【図３】エンジン出力及び大気湿度から排気中の酸素濃
度目標値を求める図面。FIG. 3 is a diagram for obtaining an oxygen concentration target value in exhaust gas from an engine output and atmospheric humidity.
【図４】排気中の酸素濃度目標値からリーンセンサ出力
目標値を求める図面。FIG. 4 is a diagram for obtaining a lean sensor output target value from an oxygen concentration target value in exhaust gas.
【図５】相対湿度〜ＮＯX 量特性図。FIG. 5 is a relative humidity-NO x amount characteristic diagram.
Ａ・・・空気 Ｇ・・・燃料ガス Ｈ・・・大気湿度 Ｌ・・・リーンセンサ出力 Ｍ・・・ガスバイパス弁開度 Ｐ・・・エンジン出力 １・・・ガスエンジン ２・・・吸気通路 ３・・・エアフィルタ ４・・・ミキサ ５・・・ターボチャージャ ６・・・インタクーラ ７・・・スロットル ８・・・供給管 ８ａ・・・バイパス管 ９・・・ガスバイパス弁 １０・・・排気通路 １１・・・リーン酸素センサ １２・・・制御ユニット １３・・・エンジン出力センサ １４・・・湿度計 A ... Air G ... Fuel gas H ... Atmospheric humidity L ... Lean sensor output M ... Gas bypass valve opening P ... Engine output 1 ... Gas engine 2 ... Intake Passage 3 ... Air filter 4 ... Mixer 5 ... Turbocharger 6 ... Intercooler 7 ... Throttle 8 ... Supply pipe 8a ... Bypass pipe 9 ... Gas bypass valve 10 ... Exhaust passage 11: lean oxygen sensor 12: control unit 13: engine output sensor 14: hygrometer
Claims (3)
排気中の酸素濃度目標値を演算し、その演算した排気中
の酸素濃度目標値からリーン酸素センサの出力目標値を
演算し、この演算したリーン酸素センサの出力目標値か
ら空燃比調節手段の設定値を演算し且つその演算結果通
りに該空燃比調節手段を設定し、リーン酸素センサの出
力値を取込んで前記目標値と比較し、両者が等しくなる
ように空燃比調節手段を制御することを特徴とするガス
エンジンの空燃比制御方法。1. An engine output value and atmospheric humidity are taken in to calculate an oxygen concentration target value in exhaust gas, and a lean oxygen sensor output target value is calculated from the calculated oxygen concentration target value in exhaust gas. The set value of the air-fuel ratio adjusting means is calculated from the calculated output target value of the lean oxygen sensor, and the air-fuel ratio adjusting means is set according to the calculation result, and the output value of the lean oxygen sensor is fetched and compared with the target value. However, the air-fuel ratio control method for a gas engine is characterized in that the air-fuel ratio adjusting means is controlled so that they are equal to each other.
ある請求項１のガスエンジンの空燃比制御方法。2. The air-fuel ratio control method for a gas engine according to claim 1, wherein the air-fuel ratio adjusting means is a gas bypass valve.
ある請求項１のガスエンジンの空燃比制御方法。3. The air-fuel ratio control method for a gas engine according to claim 1, wherein the air-fuel ratio adjusting means is an air bypass valve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4325297A JPH06213055A (en) | 1992-12-04 | 1992-12-04 | Air-fuel ratio controller of gas engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4325297A JPH06213055A (en) | 1992-12-04 | 1992-12-04 | Air-fuel ratio controller of gas engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06213055A true JPH06213055A (en) | 1994-08-02 |
Family
ID=18175247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4325297A Pending JPH06213055A (en) | 1992-12-04 | 1992-12-04 | Air-fuel ratio controller of gas engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06213055A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102493884A (en) * | 2011-12-23 | 2012-06-13 | 重庆潍柴发动机厂 | Gas inlet control method for large-power gas engine |
| JP2017141814A (en) * | 2016-01-13 | 2017-08-17 | ヴィンタートゥール ガス アンド ディーゼル リミテッド | Method and system for optimizing fuel consumption of two stroke turbo supercharged low speed diesel engine |
-
1992
- 1992-12-04 JP JP4325297A patent/JPH06213055A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102493884A (en) * | 2011-12-23 | 2012-06-13 | 重庆潍柴发动机厂 | Gas inlet control method for large-power gas engine |
| JP2017141814A (en) * | 2016-01-13 | 2017-08-17 | ヴィンタートゥール ガス アンド ディーゼル リミテッド | Method and system for optimizing fuel consumption of two stroke turbo supercharged low speed diesel engine |
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