JP2005248928A - Exhaust emission control device in internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce contamination in exhaust while minimizing addition of new parts. <P>SOLUTION: On a tip of a water supply pipe 18 connected in the middle of piping 16 downstream of a water pump 12 and upstream of a radiator 15, a spray nozzle 19 is installed. The spray direction of the spray nozzle 19 is set into an exhaust pipe 17 in the flow direction of exhaust. Cooling water W flowing into the water supply pipe 18 is sprayed from the spray nozzle 19 into the exhaust pipe 17 by delivery action of the water pump 12. Mist water sprayed into the exhaust pipe 17 gets in gas-liquid contact with exhaust gas flowing in the exhaust pipe 17. Water after getting in gas-liquid contact with the exhaust gas hits on separation plates 20 and 21 to drop onto a water receiving container 22. Cooling water W in the water receiving container 22 is sucked by the water pump 12 to be recovered through a water recovering pipe 23 to piping 13. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an exhaust gas purification device in an internal combustion engine provided with cooling means for circulating cooling water to cool the internal combustion engine.

For example, Patent Documents 1 and 2 disclose purification devices for removing unclean substances (black smoke particles, nitrogen oxides, exhaust odor components, etc.) contained in exhaust gas generated in an internal combustion engine.
In the apparatus disclosed in Patent Document 1, a liquid is sprayed from a spray nozzle into a pipe body serving as an exhaust passage. The liquid sprayed from the spray nozzle is collected in the liquid collector, and the liquid collected in the liquid collector is sprayed from the spray nozzle again by the pump. In the apparatus disclosed in Patent Document 2, the cleaning liquid into which the chemical has been injected is sprayed from a spray nozzle into a cleaning tower serving as an exhaust passage.

The devices disclosed in Patent Documents 1 and 2 attempt to purify the exhaust gas by removing unclean substances from the exhaust gas by gas-liquid contact between the sprayed liquid and the exhaust gas.
Japanese Utility Model Publication No. 5-32711 JP 2002-273151 A

  However, as a device for spraying the liquid, a dedicated liquid tank, a liquid circulation pump and the like are newly required. Such addition of new parts is not desirable for a vehicle having a large weight constraint or mounting space constraint, for example.

  An object of the present invention is to reduce the uncleanness of exhaust gas while suppressing the addition of new parts as much as possible.

  To this end, the present invention is directed to an exhaust gas purifying apparatus in an internal combustion engine having a radiator and a water pump, and provided with a cooling means for circulating cooling water by the operation of the water pump to cool the internal combustion engine. In the invention according to Item 1, water injection means for injecting the cooling water into the exhaust path of the exhaust gas by the operation of the water pump, and cooling water injected from the water injection means are collected in a water circulation path in the cooling means. And an exhaust gas purification device including a recovery means for the purpose.

  At least a part of the unclean substances (aldehyde, black smoke particles, etc., which are components of exhaust gas odor) contained in the exhaust gas in gas-liquid contact with the cooling water for cooling the internal combustion engine is injected from the water injection means. Trapped in the cooling water. Since the cooling water for cooling the internal combustion engine is used for purifying the exhaust gas, the addition of new parts is less than before. The configuration using the discharge pressure of the water pump to inject cooling water for bringing the exhaust gas into gas-liquid contact does not require the addition of a new water pump.

  According to a second aspect of the present invention, there is provided the water supply passage according to the first aspect, wherein the water supply passage is branched and connected to the water circulation path downstream of the water pump and upstream of the radiator, and the injection nozzle is connected to the water supply passage. Water separation means that constitutes the water injection means and is interposed on the exhaust path to separate water from the exhaust gas flow; a water circulation path upstream of the water pump and downstream of the radiator; and the water separation means; The recovery means provided with a water recovery passage connecting the two.

  A part of the cooling water in the water circulation path is sent to the water supply passage by the discharge pressure of the water pump and is jetted from the jet nozzle. The cooling water in gas-liquid contact with the exhaust gas is separated from the exhaust gas by the water separation means on the exhaust path, and recovered to the water circulation path upstream of the water pump and downstream of the radiator.

  According to a third aspect of the present invention, in the second aspect, a separation plate interposed on the exhaust path so as to block an exhaust gas flow, and a water circulation path provided immediately below the separation plate and connected to the water circulation path upstream of the water pump. The said water separation means provided with the water receiving container was comprised.

  The exhaust gas stream containing water collides with the separation plate, and the water flowing together with the exhaust gas stream is separated from the exhaust gas stream by the collision. The separated water returns to the water circulation path upstream of the water pump via the water receiving container.

According to a fourth aspect of the present invention, in any one of the second and third aspects, the spray nozzle that sprays the cooling water in a mist form is the spray nose.
Spray water has good gas-liquid contact efficiency with exhaust gas.

  The present invention has an excellent effect of reducing the uncleanness of exhaust gas while suppressing the addition of new parts as much as possible.

A first embodiment embodying the present invention will be described below with reference to FIGS. 1 (a) and 1 (b).
As shown in FIG. 1A, pipes 13 and 14 are connected to a water pump 12 that obtains a rotational driving force from the internal combustion engine 11. The pipe 13 is connected to a water outlet of the radiator 15, and the pipe 14 is connected to an inlet of a water path (not shown) in the internal combustion engine 11. A pipe 16 is connected to an outlet of a water path (not shown) in the internal combustion engine 11. The pipe 16 is connected to the water inlet of the radiator 15. Note that a cooling water tank (not shown) is accommodated in the radiator 15.

  The water pump 12, the radiator 15, and the pipes 13, 14, 16 constitute cooling means for cooling the internal combustion engine by circulating cooling water. The pipes 13, 14, and 16 constitute a water circulation path.

  Exhaust gas generated in the internal combustion engine 11 is discharged to the atmosphere via the exhaust pipe 17. A water supply pipe 18 is branched and connected in the middle of the pipe 16 downstream of the water pump 12 and upstream of the radiator 15. A spray nozzle 19 is attached to the tip of a water supply pipe 18 as a water supply passage. The spray nozzle 19 is connected to a bent portion in the middle of the exhaust pipe 17 serving as an exhaust path. The spray direction in the spray nozzle 19 as the spray nozzle is directed in the exhaust pipe 17 and in the exhaust gas flow direction.

  As shown in FIG. 1B, a pair of separation plates 20 and 21 are disposed in the middle of the exhaust pipe 17 downstream of the connection portion between the water supply pipe 18 and the exhaust pipe 17. Separation plates 20 and 21 are arranged in parallel to each other in a direction orthogonal to the flow direction of the exhaust gas in the exhaust pipe 17 and spaced in the flow direction of the exhaust gas. A water receiving container 22 is disposed immediately below the separation plates 20 and 21. The water receiving container 22 is connected to the peripheral surface of the exhaust pipe 17, and the exhaust gas in the exhaust pipe 17 does not leak to the outside from the connecting portion between the exhaust pipe 17 and the water receiving container 22.

  A water recovery pipe 23 is connected to the bottom wall of the water receiving container 22. A water recovery pipe 23 as a water recovery passage is connected to a pipe 13 upstream of the water pump 12 and downstream of the radiator 15.

  When the internal combustion engine 11 is operated, the water pump 12 sucks the cooling water W in the pipe 13 and discharges it to the pipe 14 side. The cooling water W discharged to the pipe 14 passes through the water path in the internal combustion engine 11 to cool the internal combustion engine 11, and the cooling water W that has cooled the internal combustion engine 11 flows out to the pipe 16. A part of the cooling water W flowing out to the pipe 16 flows to the radiator 15 side, and the rest flows to the water supply pipe 18. The cooling water W that has flowed to the radiator 15 side returns to the pipe 13 via the cooling water tank in the radiator 15.

  The cooling water W that has flowed into the water supply pipe 18 is sprayed from the spray nozzle 19 into the exhaust pipe 17 by the discharge action of the water pump 12. The atomized water sprayed into the exhaust pipe 17 comes into gas-liquid contact with the exhaust gas flowing through the exhaust pipe 17. The water in gas-liquid contact with the exhaust gas collides with the separation plates 20 and 21 and drops into the water receiving container 22. The cooling water W in the water receiving container 22 is recovered to the pipe 13 through the water recovery pipe 23 by the suction action of the water pump 12. The exhaust gas passes through the lower side of the separation plates 20 and 21 and is discharged out of the exhaust pipe 17.

  The water supply pipe 18 and the spray nozzle 19 constitute water injection means for injecting the cooling water W into the exhaust pipe 17 by the operation of the water pump 12. The separation plates 20 and 21 and the water recovery pipe 23 constitute water separation means for separating water from the exhaust gas flow. The water separation means and the water recovery pipe 23 constitute a recovery means for recovering the cooling water injected from the water injection means to the water circulation path in the cooling means.

In the first embodiment, the following effects can be obtained.
(1-1) At least a part of the unclean substances (aldehyde, black smoke particles, etc., which are components of exhaust gas odor) contained in the exhaust gas in gas-liquid contact with the mist-like cooling water in the exhaust pipe 17, Captured by mist-like cooling water. The cooling water W for cooling the internal combustion engine 11 is used in purification of exhaust gas in the form of a mist. The spraying means for making the cooling water W mist can be configured by newly adding a water supply pipe 18 and a spray nozzle 19 to the cooling means for cooling an internal combustion engine conventionally used.

  The recovery means for recovering the mist-like cooling water sprayed from the spray nozzle 19 to the water circulation path in the cooling means is a separation plate 20, 21 and a water receiving container for the cooling means for cooling an internal combustion engine conventionally used. 22 and the water recovery pipe 23 can be newly added.

  In the conventional apparatus for purifying exhaust gas using water other than the cooling water in the cooling means for cooling the internal combustion engine, a dedicated water tank, a dedicated water circulation pump and the like are newly required. In this embodiment, since a dedicated water tank and a dedicated water circulation pump are not required, the addition of new parts is less than in the conventional case.

  (1-2) The exhaust gas flow including the spray water having high gas-liquid contact efficiency with the exhaust gas collides with the separation plates 20 and 21, and by this collision, the spray water in the exhaust gas is separated from the exhaust gas flow. The The separated water returns to the water circulation path (pipe 13) upstream of the water pump 12 through the water receiving container 22 and the water recovery pipe 23 immediately below the separation plates 20 and 21. The configuration in which the exhaust gas flow containing the spray water collides with the separation plates 20 and 21 to separate the water from the exhaust gas flow is suitable for efficient water separation with a simple configuration.

  (1-3) The direction of water spray from the spray nozzle 19 is along the flow direction of the exhaust gas. That is, the water spray from the spray nozzle 19 does not become an exhaust resistance related to the exhaust gas, and the configuration in which the direction of the water spray from the spray nozzle 19 matches the flow direction of the exhaust gas is to avoid an increase in the exhaust resistance. Is preferred. Further, the spray water is difficult to adhere to the inner wall of the exhaust pipe 17, and the exhaust pipe 17 is not corroded by the spray water.

(1-4) The unclean substances in the exhaust gas trapped in the cooling water W serve to lower the freezing temperature of the cooling water W.
Next, a second embodiment of FIG. 2 will be described. The same reference numerals are used for the same components as those in the first embodiment.

  In the second embodiment, a cooling water tank 24 is provided outside the radiator 15. Pipes 13A and 13B between the radiator 15 and the water pump 12 are connected in the cooling water tank 24, and exhaust pipes 17A and 17B are also connected in the cooling water tank 24. The cooling water tank 24 always stores a certain amount or more of the cooling water W.

  The pipe 13 </ b> B in the cooling water tank 24 is always below the liquid level of the cooling water W in the cooling water tank 24. When the internal combustion engine 11 is operated, the cooling water in the cooling water tank 24 is pumped up through the pipe 13 </ b> B by the suction action of the water pump 12 and is sent to the internal combustion engine 11 through the pipe 14. The cooling water W sent from the internal combustion engine 11 to the radiator 15 is sent into the cooling water tank 24 via the pipe 13A.

  The exhaust pipes 17A and 17B in the cooling water tank 24 are always above the liquid level of the cooling water W in the cooling water tank 24. Exhaust gas generated in the internal combustion engine 11 is discharged to the atmosphere via the exhaust pipe 17A, the cooling water tank 24, and the exhaust pipe 17B.

  The front end side of the exhaust pipe 17A faces downward and is connected to the cooling water tank 24, and the spray nozzle 19 is connected to the bent portion of the exhaust pipe 17A. The spraying direction of the spray nozzle 19 connected to the tip of the water supply pipe 18 is directed downward in the exhaust pipe 17A facing downward. The mist-like water sprayed from the spray nozzle 19 into the exhaust pipe 17A by the discharge action of the water pump 12 makes gas-liquid contact with the exhaust gas flowing through the exhaust pipe 17A. The water in gas-liquid contact with the exhaust gas is mixed with the stored water in the cooling water tank 24.

  In the second embodiment, the same effects as the items (1-1) and (1-3) in the first embodiment can be obtained. Further, in the second embodiment, since the spray water sprayed from the spray nozzle 19 into the exhaust pipe 17A is sprayed toward the liquid level of the stored water in the cooling water tank 24, it is more than in the case of the first embodiment. In addition, water separation (that is, cooling water recovery) can be performed more efficiently.

Next, a third embodiment of FIG. 3 will be described. The same reference numerals are used for the same components as those in the first embodiment.
In the third embodiment, an electromagnetic on-off valve 25 is interposed on the water supply pipe 18. The electromagnetic opening / closing valve 25 receives excitation / demagnetization control of the control device 26, and the control device 26 controls excitation / demagnetization of the electromagnetic switching valve 25 based on temperature detection information obtained by the exhaust gas temperature detector 27. The exhaust temperature detector 27 detects the temperature of the exhaust gas in the exhaust pipe 17. When the temperature detected by the exhaust temperature detector 27 is lower than a preset reference temperature, the control device 26 excites the electromagnetic on-off valve 25 to open the valve. When the water pump 12 is operating, the cooling water is sprayed from the spray nozzle 19 when the electromagnetic on-off valve 25 is in the valve open state. When the temperature detected by the exhaust gas temperature detector 27 is equal to or higher than a preset reference temperature, the control device 26 demagnetizes the electromagnetic on-off valve 25 and closes the valve. When the electromagnetic on-off valve 25 is closed, the cooling water is not sprayed from the spray nozzle 19.

  Aldehydes and black smoke particles are likely to be generated when the exhaust temperature is low. Even when a part of the sprayed cooling water is released into the atmosphere together with the exhaust gas, if the cooling water is sprayed from the spray nozzle 19 only when the exhaust temperature is low, aldehyde and black smoke particles are removed. It is possible to suppress the cooling water from being reduced while efficiently capturing the cooling water.

In the present invention, the following embodiments are also possible.
(1) In the first embodiment, a filter may be interposed on the water supply pipe 18, and the unclean substances in the exhaust gas captured by the spray water may be removed from the cooling water by the filter.

(2) In the first embodiment, the linear jet water may collide with the separation plate 20 to be scattered, and the exhaust gas may be purified by the scattered water.
The technical idea that can be grasped from the embodiment described above will be described below.

  [1] The exhaust gas purifying apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein the water injection direction of the water injection means is aligned with the flow direction of the exhaust gas.

The 1st Embodiment is shown, (a), (b) is a lineblock diagram of a cooling means and an exhaust gas purification device. The block diagram of the cooling means and exhaust-gas purification apparatus which shows 2nd Embodiment. The block diagram of the cooling means and exhaust-gas purification apparatus which shows 3rd Embodiment.

Explanation of symbols

  11: Internal combustion engine. 12 ... Water pump. 13, 14, 16... Pipes constituting the water circulation path. 15 ... Radiator constituting the cooling means. 17: An exhaust pipe serving as an exhaust path. 18: A water supply pipe serving as a water supply passage constituting water injection means. 19: A spray nozzle as a spray nozzle constituting the water spray means. 20, 21... Separation plates constituting water separation means. 22: A water receiving container constituting water separating means. 23: A water recovery pipe as a water recovery passage constituting the recovery means. W: Cooling water.

Claims (4)

In an exhaust gas purifying apparatus in an internal combustion engine having a radiator and a water pump, and having cooling means for cooling the internal combustion engine by circulating cooling water by the operation of the water pump,
Water injection means for injecting the cooling water into the exhaust path of the exhaust gas by the operation of the water pump;
An exhaust gas purifying apparatus for an internal combustion engine, comprising: recovery means for recovering cooling water injected from the water injection means to a water circulation path in the cooling means.   The water injection means includes a water supply passage branched and connected to the water circulation path downstream of the water pump and upstream of the radiator, and an injection nozzle connected to the water supply passage, and the recovery means Water separation means interposed on the exhaust path for separating water from the exhaust gas flow, and a water recovery passage connecting the water separation path upstream of the water pump and downstream of the radiator and the water separation means. The exhaust gas purification apparatus for an internal combustion engine according to claim 1, which is provided.   3. The internal combustion engine according to claim 2, wherein the water separation unit includes a separation plate interposed on the exhaust path so as to block an exhaust gas flow, and a water receiving container provided immediately below the separation plate. Exhaust gas purification device.   The exhaust gas purifying apparatus for an internal combustion engine according to any one of claims 2 and 3, wherein the injection nozzle is a spray nozzle that injects cooling water in a mist form.

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