JPH073008Y2 - Intake and exhaust treatment device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an intake / exhaust treatment device for an internal combustion engine that supplies oxygen-enriched air to a combustion chamber.

(Prior Art) Not all of the air supplied to the internal combustion engine contributes to the combustion of fuel, and only about 20% of oxygen contained in the air burns the fuel, and about the rest accounts for about 30%. 80% of nitrogen is exhausted outside as it is as exhaust gas.

Therefore, supplying only the oxygen necessary for combustion brings great advantages to downsizing of the engine and reduction of vibration, but on the other hand, problems such as installation of oxygen supply device should be solved in terms of cost and space. However, even if such a method is theoretically established, it is extremely difficult to put it into practical use.

By the way, an oxygen-enriched film is known to increase the oxygen concentration in the air. This is to increase the concentration of oxygen contained in the permeated air by using a non-porous membrane made of organic polymer material and utilizing the difference in permeability between oxygen and nitrogen when passing through the membrane. (For example, “Industrial heating” September 1986 issue and
See the October issue "Development of oxygen-enriched membranes and their application to combustion systems").

Therefore, as disclosed in Japanese Utility Model Laid-Open No. 61-49063 by the present applicant, a part of the air supplied to the engine is stored in a tank in a state where the oxygen concentration is increased through an oxygen enrichment device, and a specific amount of air is stored. There is also proposed a device that improves the combustion of the engine by supplying the stored oxygen-enriched air during operation.

(Problems to be solved by the device) However, since the oxygen concentration and the amount of permeation of oxygen-enriched air that permeates the oxygen-enriching device are proportional to the pressure difference between the upstream and the downstream of the oxygen-enriching membrane, this difference In order to generate pressure, in the above device, the air pressurized by the turbocharger is sent to the oxygen enrichment device, but by pressurizing the air by the turbocharger, the temperature above the temperature at which the oxygen enrichment membrane operates properly is exceeded. There was a problem in durability because the air temperature might rise.

Furthermore, of the air introduced into the oxygen enrichment device, the proportion of air with a high nitrogen concentration that does not permeate the oxygen enrichment membrane is large,
If the oxygen-enriched air is set to cover the entire required intake air amount of the engine, if the total air amount is pressurized by the turbocharger at this time, the capacity of the turbocharger becomes very large.

The present invention aims to solve such a problem.

(Means for Solving Problems) The present invention has an intake compressor of a turbocharger installed in an intake passage of an engine and an exhaust turbine installed in an exhaust passage of the engine, while an oxygen enrichment device is installed upstream of the turbocharger. A passage for taking out the oxygen-enriched air from the enriching device was connected to the intake compressor, and a passage for taking out the nitrogen-enriched air was connected to the tank via the air compressor.

(Operation) The air that has passed through the oxygen enrichment membrane of the oxygen enricher is sucked by the intake compressor of the turbocharger and supplied to the intake passage of the engine.

On the other hand, the air that does not pass through the oxygen-enriched membrane is sucked by the air compressor and stored in the tank.

Since the amount of air drawn into the intake compressor of the turbocharger is only oxygen-enriched air that does not contain nitrogen-enriched air, it is possible to reduce the capacity of the turbocharger, and the oxygen-enriched device does not change the atmosphere. Since it is sucked, the intake air temperature does not rise above the proper operating temperature of the oxygen-rich film.

(Example) The Example of this invention is described based on drawing.

In FIG. 1, 1 is an engine, 2 is an intake passage, 3 is an exhaust passage, 4 is a turbocharge, and a turbocharger 4 drives a compressor 4B by a turbine 4A rotating by the pressure of exhaust gas flowing through the exhaust passage 3. Then, the compressed air is sent into the intake passage 2.

An oxygen enrichment device 6 is set upstream of the turbocharger 4, and the air from the air cleaner 5 passes through the oxygen enrichment device 6 and is sucked.

The oxygen enrichment device 6 is provided with an oxygen enrichment film 6A inside, and an oxygen enriched air having a high oxygen concentration which is introduced from an inlet portion 6B connected to the passage 5A from the air cleaner 5 and permeates the oxygen enrichment film 6A is exited. Nitrogen-enriched air having a high nitrogen concentration, which is introduced from the portion 6C to the oxygen-enriched passage 7 and does not permeate the oxygen-enriched membrane 6A, is introduced from another outlet portion 6D to the nitrogen-enriched passage 8.

The oxygen enrichment passage 7 is connected to the intake compressor 4B of the turbocharger 4, and the nitrogen enrichment passage 8 is connected to the tank 10 via an air compressor 9.

The oxygen-enriched passage 7 and the nitrogen-enriched passage 8 are the passages on the inlet side.
Constant differential pressure reducing valves 12 and 13 are respectively interposed between the 5A and
When the pressure difference between the passages exceeds a specified value, the constant pressure reducing valve 1
The valves 2 and 13 open to introduce air directly from the upstream side of the oxygen enrichment device 6.

An exhaust gas recirculation passage 14 is provided for short-circuiting between the intake passage 2 downstream of the intake compressor 4B and the exhaust passage 3 upstream of the exhaust turbine 4A to recirculate a part of the exhaust gas into the intake air.
The opening of the control valve 15 installed in this passage 14 is adjusted by the controller 16
Is controlled according to the operating state.

It is configured as described above, and the operation will be described below.

The turbocharger 4 is rotated by the exhaust gas when the engine 1 is operated. The exhaust turbine 4A rotates the intake compressor 4B.
Is driven to suck air from the oxygen enriched passage 7. On the other hand, the air compressor 9 is driven by the engine 1,
Air is sucked from the nitrogen enriched passage 8.

The oxygen-enriched air of the oxygen-enriching device 6 that has permeated the oxygen-enriched air 6A and has an increased oxygen concentration flows into the oxygen-enriched passage 7, and does not permeate the oxygen-enriched membrane 6A, but is relatively nitrogen-rich. The concentrated nitrogen-enriched air flows into the nitrogen-enriched passage 8.

Therefore, the engine 1 is supplied with air having a high oxygen concentration from the oxygen-enriched passage 7 through the intake passage 2, whereby the combustion is improved, and the output and fuel consumption are improved and smoke is reduced.

The intake compressor 4B of the turbocharger 4 sucks only oxygen-enriched air supplied to the engine and does not need to suck nitrogen-enriched air, so that the air capacity can be small. Further, since the oxygen enrichment device 6 is located upstream of the intake compressor 4B, the high temperature air compressed by the compressor 4B does not pass through the oxygen enrichment device 6 and the oxygen enrichment membrane 6A is always operated in the proper operating temperature range. Can be kept at

Although the combustion temperature rises due to the supply of oxygen-enriched air, the amount of NOx produced tends to increase.However, by recirculating a part of the exhaust gas from the exhaust gas recirculation passage 14 into the intake air, NOx
To reduce

On the other hand, the air having a high nitrogen concentration sent into the tank 10 via the air compressor 9 is used as an air brake or other air pressure source.

By the way, depending on the operating condition of the engine, when the supply of oxygen-enriched air or nitrogen-enriched air through the oxygen-enrichment device 6 is insufficient, the pressure in the oxygen-enriched passage 7 and the nitrogen-enriched passage 8 is reduced. However, when the differential pressure with the upstream side of the oxygen enrichment device 6 becomes a predetermined value or more, the constant differential pressure reducing valve 12 or 13 opens, so it is possible to bypass the oxygen enrichment device 6 and introduce air. Therefore, it is possible to prevent the pressure loss from increasing due to the increase in the intake negative pressure.

As described above, according to the present invention, the air that has permeated the oxygen enrichment membrane of the oxygen enricher is supplied to the intake passage through the intake compressor of the turbocharger and does not permeate the oxygen enrichment membrane. Air is sucked by the air compressor and stored in the tank, and the amount of air sucked by the intake compressor of the turbocharger is only oxygen-enriched air that does not contain nitrogen-enriched air, so reduce the capacity of the turbocharger. At the same time, an air compressor can be used to suck in the nitrogen-enriched air, and since the atmosphere is sucked into the oxygen-enriching device as it is, the intake air temperature rises above the proper operating temperature of the oxygen-enriched film. It is possible to always obtain a good oxygen enrichment action.

[Brief description of drawings]

Drawing is a block diagram which shows the Example of this invention. 1 ... Engine, 2 ... Intake passage, 3 ... Exhaust passage, 4 ... Turbocharger, 4A ... Exhaust turbine, 4B ... Intake compressor, 6 ... Oxygen enrichment device, 7 ... Oxygen enrichment passage, 8 ... Nitrogen enrichment passage, 9 ... Air compressor, 10 ... Tank.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor, written by Kitamura, Io-chome, 1-chome, Ageo-shi, Saitama, Nissan Diesel Industry Co., Ltd. (72) Keiichi Niimura, 1-chome, Io-chome, Ageo, Saitama Prefecture Incorporated (72) Inventor Shuichi Nakamura 1-chome, Ichichome, Ageo-shi, Saitama Nissan Diesel Industry Co., Ltd. (56) Reference JP 62-267557 (JP, A) Actual 63-118372 (JP) , U)

Claims (1)

[Scope of utility model registration request] 1. An intake air compressor of a turbocharger is installed in an intake passage of an engine, and an exhaust turbine is installed in an exhaust passage, while an oxygen enrichment device is provided upstream of the turbocharger, and an oxygen enrichment air is supplied from the oxygen enrichment device. An intake / exhaust treatment device for an internal combustion engine, wherein a passage for taking out air is connected to the intake compressor, and a passage for taking out nitrogen-enriched air is connected to the tank via an air compressor.