JPH07217502A - High combustion efficiency method for diesel engine - Google Patents

Abstract

PURPOSE:To heighten the combustion efficiency of a diesel engine and reduce the generation of both nitrogen oxides and incompletely burnt material. CONSTITUTION:Exhaust gas or nitrogen enriched gas not having passed an oxygen enriched film, or low oxygeneration gas intermixed with both is sucked from the intake port of a cylinder 9. When a piston in the cylinder ascends to a certain extent to heighten up to immediately before the ignition temperature, the oxygen enriched gas obtained through the oxygen enriched film 4 is jetted toward injected fuel, in the optional direction and with optional pressure. The elapsed time between fuel injection and ignition is thereby short, and the binding possibility of nitrogen and oxygen becomes low so as to reduce the generation of nitrogen oxides. The fuel diffused in the cylinder 9 is mixed with the low oxygenation gas and burnt so as to further reduce the generation of nitrogen oxides. The fuel not gasified being fresh from injection is mixed with the oxygen enriched gas of high oxygen concentration and burnt in the state of being close to almost complete combustion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel engine, and more particularly to a high combustion efficiency of a diesel engine which can improve combustion efficiency and reduce the generation of both incompletely combusted substances (particulates) and nitrogen oxides. It relates to the method of conversion.

[0002]

2. Description of the Related Art In recent years, exhaust gas pollution of automobiles has become a serious problem. Diesel engines, in particular, emit a large amount of nitrogen oxides (NO _x ) that are harmful to the human body, so countermeasures against them have been a major issue. This is essentially due to the fact that diesel engines are operated at high air / fuel ratios. Due to this too much air, nitrogen, which is not directly related to combustion, is often bound at high temperature and high pressure, and the longer the combustion time in the engine, the more chemical reaction occurs with the fuel. This was due to the fact that more oxygen and nitrogen, which was not extra, were bound together. For this reason, the timing of supplying fuel into the cylinder is delayed, the piston rises to some extent, the internal pressure of the cylinder rises, and fuel is injected immediately before the ignition temperature, and ignition is performed immediately.
Measures are taken to prevent the binding of nitrogen and oxygen.

[0003]

On the other hand, by delaying the timing of fuel injection, incomplete combustion occurs in which unburned fuel becomes soot. That is, at the time when the fuel is supplied into the cylinder, the temperature of the compressed air has already risen in the cylinder. The time from fuel injection to ignition is short, and combustion will start when the fuel is not sufficiently mixed with air in that short time. Fuel that does not sufficiently contact oxygen and is not gasified is only steamed by the heat of combustion and does not participate in combustion.
This is an incompletely combusted material (soot) that has become particulates (particulate matter), which adheres to the inner wall of the cylinder and the valve to cause deterioration of combustion efficiency and a change in cylinder capacity.
It also affected the life of the engine. In addition, these pollute the outside air and cause pollution problems such as asthma and allergies.

This will be described with reference to the conceptual views of the inside of the cylinder a shown in FIGS. First, in FIG. 18, the fuel c is injected into the cylinder a from the injector b. The air d sucked from the intake port is taken into the cylinder a.
In FIG. 19, the fuel c is slightly diffused in the cylinder a, but in reality, there are many fuels c ′ that have solidified at a certain place where they have not been in contact with oxygen and have not been gasified. In other words, the air-fuel ratio in the cylinder a is not uniform, and actually various air-fuel ratio parts are formed. In FIG. 20, combustion has already started, but the fuel c ′ just injected is not gasified, and incomplete combustion occurs in this portion due to lack of oxygen. In FIG. 21, the combustion has almost finished, but the fuel that has just been steamed by the heat of combustion remains in the gas f as the incompletely combusted substance e. In order to reduce the generation of the incompletely burned substance e, it is sufficient to accelerate the fuel injection so that the fuel and the air are sufficiently mixed, but this time, since the combustion time becomes long, it is not related to the combustion. Excess oxygen and nitrogen are likely to bond with each other, and the problem of returning to the problem of increasing the amount of nitrogen oxides is returned.

As described above, the generation of nitrogen oxides and incompletely burned substances is related to the fact that if one is reduced, the other is increased, and it is not possible to simultaneously reduce both. The present invention has been made to solve the above problems, and it is an object of the present invention to provide a method for improving combustion efficiency of a diesel engine capable of reducing both nitrogen oxides and incompletely combusted substances. To aim.

[0006]

According to the method for improving the combustion efficiency of a diesel engine according to the present invention, a gasified fuel is burned by a low oxygenated gas having a small amount of oxygen, and a non-gasified fuel or a gasified fuel is used. Fuel that does not mix well with oxygen is burned by oxygen-enriched gas, and the efficiency of combustion is improved by artificially changing the components of the combustion gas according to the gasification state of the fuel.
First, a gas with a large amount of oxygen is injected toward the injected fuel with a later injection timing to facilitate the contact of the fuel with oxygen. To delay the injection timing, as is well known, means that the piston rises to some extent and the gas sucked from the intake port is compressed to some extent, the temperature rises and the fuel is easily ignited. An oxygen-enriched membrane is used to obtain the oxygen-rich gas. The oxygen-enriched film is a film through which oxygen is selectively passed, and various materials such as polybutadiene, ethyl cellulose, polypropylene, polystyrene, and polydimethylsiloxane can be used. By sucking the external air through the oxygen-enriched film with a pump, oxygen is selectively sucked to obtain an oxygen-enriched gas having a high oxygen concentration. Fuel is injected into the cylinder, which is the combustion chamber of the engine.
An appropriate amount of oxygen-enriched gas is injected in an arbitrary direction and an arbitrary pressure at which it is easy to mix with the fuel so that the oxygen and the fuel can easily come into contact with each other.

The cylinder previously sucks air for combustion before fuel injection, and the gas sucked from the intake port is a low oxygen content gas. As the oxygen-reduced gas, exhaust gas, nitrogen-enriched gas that has not passed through the oxygen-enriched film, or both are used. First, the exhaust gas circulates the exhaust gas exhausted from the cylinder and mixes with the air sent to the intake port. The exhaust gas has a small amount of oxygen due to combustion, so that the gas taken into the cylinder from the intake port has a low oxygen concentration and is a low oxygen content gas. Also, the oxygen-enriched gas is injected toward the fuel through the oxygen-enriched film, but if the oxygen-enriched film did not pass through the oxygen-enriched film, the nitrogen-enriched gas with a large ratio of nitrogen to oxygen was mixed with the air sent to the intake port. To do. Also,
Absorbs moisture in the oxygen-enriched gas that has passed through the oxygen-enriched membrane,
It is also possible to employ a method in which moisture is released into a nitrogen-enriched gas that has not passed through the oxygen-enriched membrane or a low-oxygenated gas mixed with exhaust gas.

[0008]

[Function] The oxygen-depleted gas mixed with the exhaust gas is sucked from the intake port. This is the case when the piston descends, at which point neither fuel nor oxidatively enriched gas is supplied. When the oxygen-depleted gas fills the cylinder, the piston turns upward. The cylinder rises to some extent to compress the oxygen-depleted gas, and the temperature inside the cylinder rises. At this point, fuel is injected into the cylinder. An appropriate amount of oxygen-enriched gas is injected into the injected fuel in an arbitrary direction and at an arbitrary pressure where it is easily mixed. The injection of the oxygen-enriched gas is started at the same time as or slightly before or after the fuel injection. Soon after, the temperature in the cylinder reaches the ignition point, and the fuel burns. However, the air-fuel ratio in the cylinder is not uniform, and the fuel is gasified in some parts, or there is a part that is not yet gasified. The fuel that has already diffused in the cylinder mixes with the oxygen-depleted gas filled in the cylinder and burns. At this time, since the oxygen concentration contained in the gas is low, nitrogen is less likely to be bound to oxygen. An oxygen-enriched gas exists near the fuel that has been blown out and has not sufficiently vaporized (gasified), and combustion is promoted by oxygen having a high concentration in this gas. Therefore, all the fuel is burned by oxygen, and the combustion is performed in a form close to complete combustion. As a result, the amount of incompletely combusted fuel is extremely reduced, and generation of incompletely combusted substances is suppressed. Further, since the fuel diffused in the cylinder burns in a short time, nitrogen and oxygen are less likely to be bound to each other, and generation of nitrogen oxides is suppressed. As described above, according to the present invention, an ideal air-fuel ratio is artificially created in the entire cylinder, and combustion can be efficiently performed in the entire cylinder in a short time.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on an embodiment shown in the drawings. In FIG. 1, reference numeral 1 is an air filter through which air in the external environment is taken. A part of the air is taken into the selection chamber 5 whose inside is partitioned by the oxygen-enriched film 4 through the branch pipe 3 branched from the air supply pipe 2. A heater 20 is arranged in the selection chamber 5. An oxygen pipe 6 is connected to one side of the selection chamber 5, and a suction pump 7 is arranged in the middle of the oxygen pipe 6. Air on the other side of the oxygen-enriched film 4 is sucked by the suction pump 7, passed through the oxygen-enriched film 4, and oxygen is selectively collected.

The remaining gas, which has a low oxygen concentration, joins the air supply pipe 2 directly sent from the air cleaner 1 to the engine cylinder 9 through the nitrogen pipe 8. A pump 10 for increasing the pressure is arranged between the cylinder 9 and the middle of the oxygen pipe 6. A hygroscopic material, for example, a felt 11 is spanned between the oxygen pipe 6 and the nitrogen pipe 8. This crossover method is as shown in FIGS. 14 to 16, one end is arranged in the oxygen pipe 6 and the other end is arranged in the nitrogen pipe 8. The oxygen pipe 6 is connected to the spraying device 12 of the cylinder 9 through the pressure increasing pump 10.

In the figure, 13 is a fuel tank, which is continuous with the injection device 15 of the cylinder 9 through a pump 14. The exhaust pipe 16 for sending the exhaust gas is continuous to the exhaust gas circulation circuit 17, and the exhaust pipe 18 and the circulation pipe 19 are continuous from the exhaust gas circulation circuit 17. The circulation pipe 19 is continuous with the air supply pipe 2. The exhaust gas circulation circuit 17 performs a catalytic treatment of the exhaust gas, a filter for collecting particulates generated at the time of starting, and a function of sending a part of the exhaust gas to the air supply pipe 2.

Next, the operation of the above apparatus will be described. When the engine is started, the piston 21 in the cylinder 9 starts vertical movement. At the same time, the suction pump 7 operates to start taking in the oxygen-enriched gas O. Similarly fuel tank 13
The pump 14 starts to send the fuel F from. Booster pump 10
Through which oxygen-enriched gas is sent to the injector 12. While the piston 21 descends, the intake valve 22 opens, and the air A from the air filter 1 and the oxygen enriched film 4 from the intake port 23.
The low-oxygenated gas T that did not pass through is mixed and sent into the cylinder 9. (FIG. 2) When the piston 21 rises to some extent and the temperature rises, the fuel F is injected from the injector 15 and the oxygen-enriched gas O is injected from the injector 12.
(FIGS. 3 and 10) Of the fuel F, the fuel F that has diffused in the cylinder 9 is burned by the air A that has already filled the cylinder 9. The fuel F ′ just injected is burned by the oxygen-enriched gas O. (FIGS. 11 and 12) As a result, even in a short period of time, the fuel in the cylinder 9 is completely burned. (Figure 13)

When the piston 21, which has been lowered once during combustion, rises again, the exhaust valve 24 opens and the gas G is exhausted from the exhaust port 25. The exhaust gas circulation circuit 17 sends a part of the exhaust gas G to the air supply pipe 2 through the circulation pipe 19 to further convert the air A into the oxygen-depleted gas T. The felt 11 laid between the oxygen pipe 6 and the nitrogen pipe 8
It absorbs the moisture of the oxygen-enriched gas O, which contains a relatively large amount of moisture, and releases it in the nitrogen pipe 8. With this, the nitrogen pipe 8
The oxygen-depleted gas T sent through the oxygen-containing gas is further reduced in the proportion of oxygen due to water content, and is reduced in oxygen content. If the mixture of these gases is taken into the cylinder 9 through the intake port 23, the possibility that nitrogen will be associated with oxygen becomes lower, and the generation of nitrogen oxides is significantly reduced. The felt 11 is not only laid between the oxygen pipe 6 and the nitrogen pipe 8 as shown in the figure, but also laid between the oxygen pipe 6 and the air supply pipe 2 and released in the air supply pipe 2. May be damp.

FIGS. 4 to 9 show the modes of injecting the fuel F and the oxidation-enriched gas O into the cylinder 9, respectively, and the modes and the numbers thereof are not limited to these but exist in various ways. . In particular, FIG. 7 shows that the injector 15 is housed in the injector 12, and the oxygen-enriched gas O is injected so as to wrap the fuel F therein. Further, although the felt 11 is interposed between the oxygen pipe 6 and the nitrogen pipe 8 in the above embodiments, it is not always necessary to achieve the object of the present invention. Further, the pump 10 for increasing the pressure is not always necessary, and it is almost unnecessary if the felt 11 is not used. Heater 20 placed in selection room 5
Is because the oxygen selection efficiency is higher when the oxidation-enriched film 4 maintains a certain temperature, and may not be necessary depending on the performance and size of the oxygen-enriched film 4. FIG. 17 shows a circuit 2 for keeping the oxygen concentration in the oxygen-enriched gas O constant.
6 shows an embodiment including No. 6, when the oxygen concentration in the oxygen-enriched gas O is too high, the nitrogen-enriched gas is sucked and fed into the oxygen pipe 6 to keep the oxygen concentration of the oxygen-enriched gas O constant. To do. Reference numeral 27 is a valve, which narrows the air supply pipe 2 when the amount of oxygen in the air sucked into the cylinder is too large.
A valve 28 is provided to control the amount of exhaust gas sent to the circulation pipe 19 and adjust the exhaust gas concentration. In the middle of the exhaust pipe 18, an exhaust gas purification device 2
9 is provided.

[0015]

Since the present invention has the above-mentioned structure, the following effects can be obtained. Just before the piston rises and the pressure in the cylinder rises to reach the ignition temperature, fuel can be injected and burned, and the time for nitrogen and oxygen to combine is shortened, so the generation of nitrogen oxides is reduced. be able to. Since the oxygen-enriched gas is injected toward the injected fuel, the oxygen-enriched gas, even if it is a non-gasified fuel that has just been injected or if it is gasified but does not mix well with oxygen Good combustion is performed by the oxygen in the fuel, and almost complete combustion of the fuel can be realized. Therefore, it is possible to reduce the generation of incompletely burned substances (soot) in the particulate state. Exhaust gas with low oxygen concentration, nitrogen-enriched gas that has not passed through the oxygen-enriched film, or both are sucked into the cylinder before combustion. This further reduces the possibility that nitrogen will be bound to oxygen, and can further reduce the generation of nitrogen oxides. Since the entire fuel burns in a form close to complete combustion, it is possible to improve output and save energy. Moisture in the oxygen-enriched gas is absorbed, and the low-oxygenated gas containing a large amount of water is sucked into the cylinder and used as a combustion gas. The amount of oxygen in the oxygen-depleted gas is further reduced due to the high water content, and the possibility that nitrogen and oxygen are bound to each other is reduced.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a combustion gas supply device used in the present invention.

FIG. 2 is a cross-sectional view of a state in which air is taken into the cylinder from an intake port.

FIG. 3 is a cross-sectional view of a state in which fuel and oxygen-enriched gas are injected.

FIG. 4 is a cross-sectional view of an embodiment in which fuel and oxygen-enriched gas are injected.

FIG. 5 is a cross-sectional view of another embodiment in which fuel and oxygen-enriched gas are injected.

FIG. 6 is a cross-sectional view of another embodiment in which fuel and oxygen-enriched gas are injected.

FIG. 7 is a cross-sectional view of another embodiment in which fuel and oxygen-enriched gas are injected.

FIG. 8 is a cross-sectional view of another embodiment in which fuel and oxygen-enriched gas are injected.

FIG. 9 is a cross-sectional view of another embodiment in which fuel and oxygen-enriched gas are injected.

FIG. 10 is a conceptual diagram of a state in which fuel and oxygen-enriched gas are injected.

FIG. 11 is a conceptual diagram of a state in which a fuel and an oxidation-enriched gas are mixed together.

FIG. 12 is a conceptual diagram of a state where combustion has started.

FIG. 13 is a conceptual diagram of a state in which combustion is completed.

FIG. 14 is a conceptual diagram in which a felt is bridged between an oxygen pipe and a nitrogen pipe.

FIG. 15 is a cross-sectional view of a state in which a felt is stretched between an oxygen pipe and a nitrogen pipe.

FIG. 16 is a cross-sectional view showing a state in which a felt is stretched between an oxygen pipe and a nitrogen pipe.

FIG. 17 is a conceptual diagram of another embodiment of the combustion gas supply device.

FIG. 18 is a conceptual diagram of a fuel supply state into a conventional Cinder.

FIG. 19 is a conceptual diagram showing a state where fuel is diffused in a cylinder.

FIG. 20 is a conceptual diagram of a combustion state.

FIG. 21 is a conceptual diagram after the end of combustion.

[Explanation of symbols]

 1 Air Filter 2 Air Supply Pipe 3 Branch Pipe 4 Oxygen Enrichment Membrane 5 Selection Chamber 6 Oxygen Pipe 7 Suction Pump 8 Nitrogen Pipe 9 Cylinder 10 Pump 11 Felt 12 Injector 13 Fuel Tank 14 Pump 15 Injector 16 Exhaust Pipe 17 Exhaust Gas Circulation circuit 18 Discharge pipe 19 Circulation pipe 20 Heater 21 Piston 22 Intake valve 23 Intake port 24 Exhaust valve 25 Exhaust port 26 Circuit 27 Valve 28 Valve 29 Exhaust gas purifier A Air O Oxygen enriched gas T Hypoxia gas G Gas F fuel

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F02M 25/022 33/00 C

Claims (2)

[Claims] 1. A low oxygen-containing gas in which either or both of exhaust gas and nitrogen-enriched gas that have not passed through an oxygen-enriched film are mixed into normal air is sucked from an intake port of a cylinder, and then oxygen-rich gas is added. Immediately before the piston rises, the internal pressure rises to reach the ignition temperature, the oxygen-enriched gas obtained through the chemical film,
The fuel injected from the fuel injection device in the cylinder is injected in an appropriate amount in an arbitrary direction and at an arbitrary pressure that mixes well with the fuel injected.The fuel diffused in the cylinder is burned by the oxygen-depleted gas, and the fuel not sufficiently mixed with oxygen is oxygen. A method for improving combustion efficiency of a diesel engine, in which combustion is performed by an enriched gas to improve combustion efficiency and to reduce generation of nitrogen oxides and particulates. 2. The moisture in the oxygen-enriched gas that has passed through the oxygen-enriched film is absorbed and released into the oxygen-depleted gas, and the oxygen-depleted gas containing more moisture is sucked into the cylinder. The method for improving the combustion efficiency of a diesel engine according to claim 1, wherein