JP2001164955A - Auxiliary combustion chamber-type engine and its operating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an auxiliary combustion chamber-type engine capable of increasing the life of an ignition means of an auxiliary combustion chamber by prevent the ignition means from deteriorating due to a high temperature and its operating method. SOLUTION: In the auxiliary combustion chamber-type engine 100 and its operating method, a combustion chamber 2 is surrounded by a cylinder 1 and a piston 3, and the ignition means 11 ignites air-fuel mixture within the auxiliary combustion chamber 10 communicating with the combustion chamber 2. Additionally, a liquid supply means 13 for the chamber 10 provides the chamber 10 with an incombustible liquid W supplied to the chamber 10 to evaporate for cooling the ignition means 11 by utilizing the liquid W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sub-chamber system comprising a combustion chamber surrounded by a cylinder and a piston, a sub-chamber communicating with the combustion chamber, and ignition means for igniting a mixture in the sub-chamber. The present invention relates to an engine and a method of operating a sub-chamber engine.

[0002]

2. Description of the Related Art As such a sub-chamber engine, for example, an air-fuel mixture in a sub-chamber is ignited by an igniting means and burned, and a flame by the combustion is jetted from the sub-chamber into a combustion chamber. There is a configuration in which a lean air-fuel mixture in a combustion chamber is burned, but conventionally, no special consideration has been given to deterioration of the ignition means due to heat.

[0003]

That is, since the air-fuel mixture in the sub-chamber needs to be ignited by the ignition means, it is a rich air-fuel mixture with a relatively small air ratio. Therefore, the combustion temperature in the sub-chamber is high. The sub-chamber gets quite hot as the engine runs. Therefore, in the conventional sub-chamber type engine, the ignition means of the sub-chamber is exposed to high temperature and is severely deteriorated by heat, so that it often becomes unusable in a relatively short time.

The present invention focuses on such a conventional problem, and an object of the present invention is to suppress the deterioration of the igniting means due to a high temperature and to extend the life of the igniting means in the sub-chamber. To provide an engine and its operation method.

[0005]

In order to achieve this object, the invention according to claim 1 comprises a combustion chamber surrounded by a cylinder and a piston, and a sub-chamber communicating with the combustion chamber.
A sub-chamber type engine having an ignition means for igniting the air-fuel mixture in the sub-chamber, wherein a sub-chamber liquid supply means for supplying the sub-chamber with the liquid supplied to the sub-chamber and evaporating is provided. Features a point.

That is, when the liquid is supplied to the sub-chamber by the sub-chamber liquid supply means, the liquid evaporates in the sub-chamber, and the sub-chamber is cooled by the latent heat of evaporation. Therefore, the temperature of the sub-chamber is reduced, the exposure of the ignition means of the sub-chamber to high temperatures is suppressed, and the deterioration of the ignition means due to heat can be delayed to extend the life.

The invention according to claim 2 is characterized in that the liquid is a liquid that does not burn in the sub-chamber.

[0008] Therefore, while the life of the ignition means is extended by the supply of the liquid as described above, the influence of the supply of the liquid on the combustion is suppressed, and the desired combustion is performed in the sub-chamber and the combustion chamber. You can expect.

According to a third aspect of the present invention, the liquid comprises:
It is characterized in that it is at least one liquid selected from water, chlorofluorocarbon and alternative fluorocarbons.

That is, by using water, chlorofluorocarbon, alternative chlorofluorocarbon, or a mixture of a plurality of these liquids having a relatively large latent heat of vaporization as the liquid for cooling, the sub-chamber can be efficiently used with a small amount of liquid. Can be cooled well.
Examples of the alternative chlorofluorocarbon include HFC (compound composed of hydrogen, fluorine, and carbon) and HCFC (compound composed of hydrogen, chlorine, fluorine, and carbon).

The invention according to claim 4 is characterized in that the supply timing of the liquid by the sub-chamber liquid supply means is set during an intake stroke or an exhaust stroke.

That is, during the intake stroke or the exhaust stroke, both the combustion chamber and the sub-chamber communicating therewith have a relatively low pressure, and the liquid is supplied at the low pressure, whereby the liquid is supplied smoothly. Thus, a desired location in the sub chamber can be reliably cooled.

In addition, the sub chamber liquid supply means directs the liquid toward the ignition means and ejects the liquid.
Alternatively, it may be a means for dropping the liquid onto the ignition means.

That is, by supplying the liquid by the injector, the influence of the pressure and the pressure change in the sub-chamber is small, and the liquid is jetted toward the ignition means so that the liquid is supplied to the ignition means. As a result, the ignition means can be cooled reliably. Further, by dropping the liquid onto the ignition means, the ignition means can be cooled with a simple configuration.

The above description relates to a sub-chamber type engine. According to a fifth aspect of the present invention, there is provided a combustion chamber surrounded by a cylinder and a piston, and a sub chamber communicating with the combustion chamber. A method for operating a sub-chamber engine, comprising: a chamber, and an ignition means for igniting an air-fuel mixture in the sub-chamber, wherein a liquid supplied to the sub-chamber, evaporating, and not combusting in the sub-chamber, is supplied to the sub-chamber. To cool the ignition means.

Therefore, according to this operating method, the ignition means can be reliably cooled by the latent heat of evaporation of the liquid evaporated in the sub-chamber while performing the desired combustion in the sub-chamber and the combustion chamber, and the high temperature Deterioration of the ignition means can be suppressed, and the life of the ignition means in the sub chamber can be extended.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sub-chamber engine according to the present invention and an operating method thereof will be described with reference to the drawings. As shown in FIGS. 1 and 2, the sub-chamber engine 100 includes a cylinder 1 and a piston 3 housed in the cylinder 1 and forming a combustion chamber 2 in a space surrounding the cylinder 1. Reference numeral 3 is linked to the crankshaft CS via a connecting rod 4. This engine 100
An intake valve 6 that opens and closes the intake path 5 and an exhaust valve 8 that opens and closes the exhaust path 7 are provided, and the intake, compression, combustion / expansion, and exhaust gas are exhausted in the combustion chamber 2 while opening and closing the intake valve 6 and the exhaust valve 8. The piston 3 is reciprocated in the cylinder 1 by executing various strokes, and the reciprocating motion is converted into the rotational motion of the crankshaft CS and output.

A sub-chamber 10 communicates with the combustion chamber 2 through an injection hole 9 of a nozzle called a torch nozzle. The sub-chamber 10 has an ignition means for igniting a mixture in the sub-chamber 10. And a sub-chamber 10 is provided.
A fuel supply valve 12 for supplying fuel to the fuel cell is also provided. Further, the sub-chamber 10 is provided with an injector 13 as a sub-chamber liquid supply means, and is an example of a liquid for cooling an ignition plug, that is, an incombustible liquid supplied to the sub-chamber 10 and evaporated. The water W is configured to be directed toward the spark plug 11 and to be jetted. This engine 100
Is a gas engine using natural gas containing methane as a main component as fuel G, and the fuel G is supplied to the fuel supply valve 12.
The air-fuel mixture is supplied to the sub-chamber 10 via the air passage and also supplied to the intake passage 5 so as to generate an air-fuel mixture with the combustion air A flowing through the intake passage 5.

Next, the operating state of the sub-chamber engine 100 will be described. The intake valve 6 is opened just before the piston 3 reaches the top dead center, and the combustion chamber is moved from the intake passage 5 as the piston 3 descends. 2, a mixture of fuel G and air A is sucked. This sucked air-fuel mixture has an air ratio of 1.4 to
With a lean mixture of 2.0, the intake valve 6 is closed immediately after the piston 3 begins to rise above bottom dead center. During this intake stroke, as shown in FIG.
Is activated, and the water W is spouted toward the spark plug 11 vigorously. The jetted water W evaporates upon contact with the spark plug 11 and the wall surface of the sub-chamber 10, and the ignition plug 11 and the sub-chamber 10 are cooled by the latent heat of evaporation. Note that the injection of the water W by the injector 13 is not necessarily performed when the temperature of the sub-chamber 10 or the ignition plug 11 is low, and is preferably executed when the temperature of the ignition plug 11 or the like becomes high. desirable. Also, the jet of water W
Depending on various situations, it may be executed once every cycle or once every plural cycles.

When the piston 3 rises, the exhaust valve 8 is closed. As the piston 3 rises, the lean air-fuel mixture in the combustion chamber 2 is compressed, and immediately after the piston 3 starts rising, that is, in the compression step. In the initial stage, the fuel supply valve 12 is opened, and a mixture of fuel G and air A is generated in the sub-chamber 10. The air-fuel mixture in the sub-chamber 10 is a rich air-fuel mixture having an air ratio of 0.54 to 1.2 and is set within the flammable range. In this state, the ignition plug is set immediately before the piston 3 reaches the top dead center. 11 is operated and ignited, so that the ignition and combustion of the air-fuel mixture in the sub-chamber 10 are reliably performed.

The combustion of the rich mixture in the sub-chamber 10 causes the pressure in the sub-chamber 10 to rise rapidly, and the flame in the sub-chamber 10 is directed from the injection hole 9 to the combustion chamber 2 as shown in FIG. It is spouted vigorously. That is, a flame usually called a torch is injected into the combustion chamber 2, and the torch T ignites and burns the lean mixture in the combustion chamber 2. By burning the lean air-fuel mixture in the combustion chamber 2 as described above, lean combustion can be performed as a whole, and the NOx can be reduced. Then, in this combustion / expansion process, the piston 3 is lowered by high-pressure gas generated by combustion in the combustion chamber 2, and
In the subsequent exhaust stroke, the exhaust valve 8 is opened,
As the piston 3 rises, exhaust gas from the combustion chamber 2 is discharged from the exhaust passage 7 to the outside of the engine 100.

Using the sub-chamber engine having the above-described structure, the operation for confirming the operation and effect was carried out. As a result, the combustion temperature in the sub-chamber dropped from 1800 ° C. to 1400 ° C. It was confirmed that the service life of the battery was extended from 5000 hours to 15000 hours of continuous operation.
The engine used at that time had an output of 330 kW.
The in-line six-cylinder gas engine was operated under the following conditions, and water was directly injected into the sub-chamber during the intake stroke in which the intake valve was open. Bore diameter: 165 mmφ Stroke: 180 mm Sub-chamber air ratio: about 0.85 Combustion chamber air ratio: about 2.0 Sub-chamber / combustion chamber volume ratio: 0.05 Engine rotation speed: 1800 rpm Water injection amount (to sub-chamber fuel) Ratio): 0.5

[Other Embodiments] (1) In the above embodiment, an example was shown in which water was used as the liquid to be used for cooling the sub-chamber 10 and the spark plug 11.
Any non-flammable liquid that evaporates besides water may be used.For example, Freon or alternative Freon can be used,
An appropriate mixture of these can also be used.

(2) In the above embodiment, the injector 1
3 shows an example in which the supply timing of the liquid is set during the intake stroke. However, the supply timing can be set during the exhaust stroke, and further, can be set during the compression stroke. It is not always necessary to use the injector 13, and for example, the liquid may be sucked and dropped by utilizing the low pressure state of the combustion chamber 2 in the intake stroke or the exhaust stroke. Further, in the above embodiment, the configuration in which the liquid is directly supplied to the ignition plug 11 has been described. However, the liquid is supplied to the entire sub-chamber 10 including the ignition plug 11 or supplied only to the periphery of the ignition plug 11. Various modifications are possible.

(3) In the above embodiment, the four-stroke engine 100 has been described as an example. However, the present invention can be applied to a two-stroke engine. Not limited to hydrogen,
Use various gaseous fuels such as propane and butane,
Fuels other than gaseous fuels, such as gasoline, light oil, heavy oil,
Liquid fuels such as ethanol and methanol can also be used.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a sub-chamber engine of the present invention.

FIG. 2 is a schematic configuration diagram of a sub-chamber engine of the present invention.

[Explanation of symbols]

 Reference Signs List 1 cylinder 2 combustion chamber 3 piston 10 sub-chamber 11 ignition means 13 injector as sub-chamber liquid supply means 100 sub-chamber engine W water as liquid

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F02M 25/022 F02M 25/02 H (72) Inventor Koji Moriya 4-1-2 Hiranocho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka Gas Co., Ltd. (reference) 3G023 AA12 AC03 AD21 3G092 AA07 FA38 HE03X

Claims (5)

[Claims] 1. A sub-chamber engine comprising: a combustion chamber surrounded by a cylinder and a piston; a sub-chamber communicating with the combustion chamber; and ignition means for igniting an air-fuel mixture in the sub-chamber. A sub-chamber type engine provided with sub-chamber liquid supply means for supplying a liquid supplied to the sub-chamber and evaporated to the sub-chamber. 2. The sub-chamber engine according to claim 1, wherein the liquid is a liquid that does not burn in the sub-chamber. 3. The sub-chamber engine according to claim 2, wherein the liquid is at least one liquid selected from water, CFCs, and CFC alternatives. 4. The sub-chamber engine according to claim 1, wherein the supply timing of the liquid by the sub-chamber liquid supply means is set during an intake stroke or an exhaust stroke. 5. A method for operating a sub-chamber engine, comprising: a combustion chamber surrounded by a cylinder and a piston; a sub-chamber communicating with the combustion chamber; and ignition means for igniting a mixture in the sub-chamber. A method of operating a sub-chamber engine in which a liquid supplied to the sub-chamber and evaporated and not combusted in the sub-chamber is supplied to the sub-chamber to cool the ignition means.