JPH11324812A - Venturi type mixer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce pressure loss of intake air of a venturi type mixer. SOLUTION: This venturi type mixer 30 is equipped with a fuel gas supply pipe 13 and an exhaust gas supply pipe 16, a barrel part 19 in which an internal space 20 passing intake air 27 is arranged is connected to an intake pipe 7 on the intake air side of an engine, an inner wall 21 whose cross section along the flow direction of the intake air 27 is formed into a hourglass shape from an intake air inflow side toward an intake air outflow side is arranged in the inside of the internal space 20, a space 24 into which fuel gas 10 and exhaust gas 15 are led to flow and a hourglass-shaped space 25 in which intake air 27 flows are formed between the inner wall 21 and the inside of the barrel part 19, and an ejection hole 26 through which fuel gas 10 and exhaust gas 15 are ejected to the hourglass-shaped space 25 is arranged in the part of the inner wall 21 where the hourglass-shaped space 25 is narrowed down.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Venturi mixer for mixing and supplying gaseous fuel and exhaust gas to intake air supplied to an engine.

[0002]

2. Description of the Related Art In general, in an automobile engine, a part of exhaust gas discharged from an exhaust line of the engine is supplied to the engine through an exhaust gas recirculation path by utilizing a pressure difference between the exhaust line and an intake line. A so-called exhaust gas recirculation (Exhaust Gas Recirc) for reducing the combustion temperature by suppressing the combustion of fuel in the engine by the exhaust gas returned to the intake line and reducing the combustion temperature and reducing the generation of NOx
).

An example of a Venturi type mixer conventionally used for exhaust gas recirculation will be described with reference to FIGS. 5 and 6. An intake manifold 2 is attached to an intake side of an engine 1 and an exhaust side of the engine 1 is described. The exhaust manifold 3 is attached to the. An intake pipe 7 having a compressor 5 and an air cleaner 6 of a turbocharger 4 is connected to the intake manifold 2, and an exhaust pipe 9 having a turbine 8 of the turbocharger 4 is connected to the exhaust manifold 3.

[0004] A venturi-type mixer 11 for the gas fuel 10 is connected to the middle of the intake pipe 7 by bolts via a flange 12, and the gas-fuel supply to the Venturi-type mixer 11 for the gas fuel 10 is performed. Pipe 13
Are connected with a gas fuel metering valve 14.

The intake pipe 7 located on the engine side of the Venturi mixer 11 for the gas fuel 10 is provided with a Venturi mixer 11 ′ for the exhaust gas 15 ′ having substantially the same type as the Venturi mixer 11 for the gas fuel 10. An exhaust pipe on the exhaust side of the engine 1 is connected to the venturi-type mixer 11 ′ for the exhaust gas 15 by bolts via a flange 12 so as to be arranged in series adjacent to the Venturi-type mixer 11 for the fuel 10. An exhaust gas supply pipe 16 extending from 9 is connected with an exhaust gas metering valve 17.

Here, as shown in FIG. 6, the venturi type mixers 11 and 11 'for the gas fuel 10 and the exhaust gas 15 have an inner space 2 having the same diameter as the intake pipe 7 in the body 19 thereof.
0, and an inner wall 21 is attached to the internal space 20.
The inner wall 21 has an opening 22 opposite the diameter of the inner space 20 on the side opposite to the engine.
With a drum-shaped cross section along the extending direction of the internal space 20 so as to rapidly reduce in the direction of extension of the internal space 20 to the middle part of the engine 1 side and then gradually expand to the opening 23 on the engine side. It is.

The inner wall 21 defines the inner space 20 and the body 1
A space 24 and a drum-shaped space 25 provided between the inner wall 9 and the inner wall 21
A plurality of ejection holes 26 are formed along the inner circumferential direction of the inner wall 21 on the inner periphery of the inner wall 21 of the hourglass space 25 which is most narrowed down so as to communicate the hourglass space 25 and the space 24. They are provided at equal intervals.

When the engine 1 is driven, the intake air 27 sucked by the air cleaner 6 and the compressor 5
Flows into the hourglass space 25 of the venturi-type mixer 11 for the gas fuel 10 provided in the middle of the intake pipe 7, and when the intake air 27 passes through the narrowed portion of the hourglass space 25, the intake air Since the pressure of the portion decreases at the same time as the flow velocity of the gas fuel 27 increases, the gas fuel 10 flowing into the space 24 formed between the inner wall 21 and the body portion 19 is sucked out from the ejection hole 26, and the intake gas 27 mixes the gas fuel 10. It becomes gas 28.

Subsequently, the mixed gas 28 of the gaseous fuel 10 and the intake air 27 flows into the drum-shaped space 25 of the adjacent venturi-type mixer 11 ′ for the exhaust gas 15, while the Venturi-type mixer 11 for the exhaust gas 15 A space 24 formed between the inner wall 21 and the body 19 of the exhaust manifold 3 is supplied to the engine 1 and burned by the engine 1.
A part of the exhaust gas 15 discharged from the exhaust gas through the turbine 8 and the exhaust pipe 9 flows into the exhaust gas supply pipe 16 via the exhaust gas metering valve 17 in advance.

When the mixed gas 28 passes through the narrowed portion of the hourglass space 25, the flow rate of the intake air 27 increases as in the case where the gas fuel 10 is sucked out by the venturi-type mixer 11 for the gas fuel 10. At the same time, the pressure in that portion decreases, so that the exhaust gas 15 in the space 24 is sucked out from the ejection hole 26, and becomes a mixed gas 29 in which the gas fuel 10 and the exhaust gas 15 are mixed with the intake air 27, and is supplied to the engine 1.

For this reason, each of the Venturi-type mixers 11, 1
The number of the injection holes 26 formed in 1 'is changed, and the gas fuel metering valve 14 and the exhaust gas metering valve 17 are adjusted to change the mixing ratio of the intake 27 of the mixed gas 29, the gas fuel 10, and the exhaust gas 15. Then, the exhaust gas 15 of the mixed gas 29 suppresses the combustion of the fuel in the engine 1 to lower the combustion temperature and reduce the generation of NOx.

The mixed gas 2 supplied to the engine 1
9 burns into exhaust gas 15, and a part of the exhaust gas 15 further flows from the exhaust pipe 9 through the exhaust gas supply pipe 16 and the space 24 into the hourglass space 25 of the venturi-type mixer 11 ′ for the exhaust gas 15, and the engine 1 , The exhaust pipe 9, the exhaust gas supply pipe 16 and the intake pipe 7.

[0013]

However, when the venturi-type mixer 11 for the gas fuel 10 and the venturi-type mixer 11 'for the exhaust gas 15 are adjacently arranged in two stages in series, the Venturi-type mixers 11, 11 Since the pressure loss of the mixed gases 28, 29 flowing through the drum-shaped spaces 25, 25 is large, the output of the engine 1 is reduced, and since the number of parts is large, the overall size is large and the mountability on a vehicle is poor. There was a problem that the manufacturing cost also increased.

An object of the present invention is to provide a Venturi type mixer which can solve such a problem.

[0015]

According to a first aspect of the present invention, there is provided a venturi mixer having a body provided with a gas fuel supply pipe and an exhaust gas supply pipe and provided with an internal space through which intake air is passed. An inner wall having a drum-shaped cross section along the flow direction of the intake air from the intake inflow side to the intake outflow side is provided in the internal space, and the inflow of gas fuel and exhaust gas is provided between the inner wall and the body. And a drum-shaped space through which intake air flows, and a discharge hole for gas fuel and exhaust gas is provided in the narrowed inner wall portion of the drum-shaped space.

According to a second aspect of the present invention, there is provided a venturi-type mixer having a gas fuel supply pipe and an exhaust gas supply pipe and having a body provided with an internal space through which intake air passes is connected to an intake pipe on an intake side of an engine. Inside, an inner wall having a drum-shaped cross section along the flow direction of the intake air from the intake inflow side to the intake outflow side is provided, and a space into which gas fuel and exhaust gas flows and an intake air flow are provided between the inner wall and the body. A drum-shaped space is formed, and a discharge hole for gas fuel and exhaust gas to the drum-shaped space is provided in a narrowed inner wall portion of the drum-shaped space, and further, a space provided between the inner wall and the inside of the trunk portion is provided in the space. The gas fuel supply pipe and the exhaust gas supply pipe are connected to the body so that the gas fuel flows into the gas fuel space and the exhaust gas flows into the exhaust gas space. Than it is.

In the first aspect of the present invention, the gas fuel and the exhaust gas are sucked out from the ejection hole by one venturi type mixer, so that the gas fuel venturi type mixer and the exhaust gas venturi type mixer are arranged in two stages. Since the pressure loss of the mixed gas can be reduced and the number of parts can be reduced as compared with the above, the overall size can be reduced, the mountability in a vehicle can be improved, and the manufacturing cost can be reduced.

In the case of the second invention, the gas fuel and the exhaust gas are not mixed in the space formed between the inner wall and the body of the Venturi mixer by the partition provided in the Venturi mixer. The gas fuel and the exhaust gas do not flow back to one another due to the pressure difference when they flow into the space. Further, since the gas fuel and the exhaust gas are sucked out from the ejection holes by one venturi-type mixer, the pressure loss of the mixed gas can be reduced as compared with the case where the venturi-type mixer is arranged in two stages. As in the first invention, the number of parts can be reduced by the mold mixer, so that the overall size can be reduced and the mountability on a vehicle can be improved, and the manufacturing cost can be reduced.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a Venturi type mixer according to a first embodiment of the present invention.
Parts denoted by the same reference numerals as those in FIG. 6 represent the same items.

The Venturi mixer 30 is connected to the intake pipe 7 of the engine 1 by the gas fuel supply pipe 1.
3 and the exhaust gas supply pipe 16 are connected in one stage instead of being arranged in two stages as in a conventional venturi mixer for gas fuel and a venturi mixer for exhaust gas.

The Venturi mixer 30 is substantially the same as the conventional Venturi mixer for exhaust gas and gas fuel.
An inner space 20 having the same diameter as the intake pipe 7 is provided in the body 19, and an inner wall 21 is attached to the inner space 20. The inner wall 21 is formed such that the diameter of the internal space 20 is reduced rapidly in the direction in which the internal space 20 extends from the anti-engine side opening 22 to the middle part on the engine 1 side, and then gradually expands to the engine side opening 23. It has a drum-shaped cross section along the extending direction of the internal space 20.

The inner wall 21 defines the inner space 20 and the body 1.
A space 24 and a drum-shaped space 25 provided between the inner wall 9 and the inner wall 21
A plurality of ejection holes 26 are formed along the inner circumferential direction of the inner wall 21 on the inner periphery of the inner wall 21 of the hourglass space 25 which is most narrowed down so as to communicate the hourglass space 25 and the space 24. They are provided at equal intervals.

Further, the inner wall 21 and the torso 1 are attached to the torso 19.
Gas fuel supply pipe 1 so as to communicate with the space 24 between
3 and the exhaust gas supply pipe 16 are connected to the body 19 respectively.

The operation of the first embodiment of the present invention will be described below.

When the engine 1 is driven, the gas fuel 10 is supplied from the gas fuel supply pipe 13 to the gas fuel metering valve 14 into the space 24 formed between the inner wall 21 of the venturi mixer 30 and the body 19. At the same time, a part of the exhaust gas 15 burned by the engine 1 and discharged from the exhaust manifold 3 through the turbine 8 and the exhaust pipe 9 flows from the exhaust gas supply pipe 16 through the exhaust gas metering valve 17, Gas fuel 1 in space 24
0 and the mixed gas 31 of the exhaust gas 15.

On the other hand, the air cleaner 6 and the compressor 5
The intake air 27 sucked by the Venturi mixer 30
Flows into the drum-shaped space 25 of the
When the gas passes through the constricted portion of the hourglass space 25, the gas flowing into the space 24 formed between the inner wall 21 and the body portion 19 because the flow velocity of the intake air 27 increases and the pressure in that portion decreases at the same time. The mixed gas 31 of the fuel 10 and the exhaust gas 15 is sucked out from the ejection hole 26, and the intake air 27 becomes the mixed gas 29 in which the gas fuel 10 and the exhaust gas 15 are mixed and supplied to the engine 1.

For this reason, one Venturi type mixer 30
Since the gas fuel 10 and the exhaust gas 15 are sucked out from the ejection holes 26, the pressure loss of the mixed gas 29 is reduced as compared with the case where the venturi mixer for the gas fuel and the venturi mixer for the exhaust gas are arranged in two stages. In addition, since the number of components can be reduced, the overall size can be reduced, the mountability in a vehicle can be improved, and the manufacturing cost can be reduced.

Further, the number of the ejection holes 26 formed in the venturi-type mixer 30 is changed, and the gas fuel metering valve 1 is changed.
4 and the exhaust gas metering valve 17 are adjusted to change the mixing ratio of the intake 27 of the mixed gas 29, the gas fuel 10 and the exhaust gas 15, and the exhaust gas 15 of the mixed gas 29 suppresses fuel combustion in the engine 1. It is the same as the conventional example that the combustion temperature can be reduced and the generation of NOx can be reduced.

FIG. 4 shows a second example of the embodiment of the present invention. In the figure, portions denoted by the same reference numerals as those in FIG. 1 represent the same components.

The Venturi type mixer 32 of the second example is a Venturi type mixer substantially similar to the first example,
A partition 33 is provided in a space 24 formed between the body 1 and the body 19.

The partition wall 33 defines a space provided between the inner wall 21 of the venturi-type mixer 32 and the inside of the body 19 in the middle of the internal space 20 in the direction in which the internal space 20 extends. It is formed by connecting the inner periphery of the body portion 19 and the outer periphery of the inner wall 21 so as to be divided into the exhaust gas space 35 on one side.

A gas fuel supply pipe 13 is connected to a gas fuel metering valve 14 so as to communicate with a gas fuel space 34.
The exhaust gas supply pipe 16 is connected with an exhaust gas metering valve 17 so as to communicate with the exhaust gas space 35.

In the vicinity of the partition wall 33 of the inner wall 21, a plurality of ejection holes 26 are formed along the inner circumferential direction of the inner wall 21 so that the gas fuel space 34 and the exhaust gas space 35 communicate with the hourglass space 25, respectively. At regular intervals, for gas fuel 10 and exhaust gas 15
Are provided in two rows.

The operation of the second embodiment of the present invention will be described below.

When the engine 1 is driven, the gas fuel 10 flows from the gas fuel supply pipe 13 through the gas fuel metering valve 14 into the gas fuel space 34 divided by the partition wall 33, and at the same time, the exhaust gas space. A part of the exhaust gas 15 which is burned by the engine 1 and discharged from the exhaust manifold 3 through the turbine 8 and the exhaust pipe 9 flows into the exhaust gas supply pipe 16 via the exhaust gas metering valve 17 in advance.

On the other hand, the air cleaner 6 and the compressor 5
Venturi-type mixer 3
When the gas flows into the second drum-shaped space 25 and passes through the narrowed portion of the drum-shaped space 25 in the same manner as in the conventional example, the flow rate of the intake air 27 increases and the pressure in that portion decreases at the same time. The gas fuel 10 and the exhaust gas 15 flowing into the space 34 and the exhaust gas space 35 are separately sucked out from the ejection holes 26 for the gas fuel 10 and the exhaust gas 15, and the intake 27 is a mixed gas 29 in which the gas fuel 10 and the exhaust gas 15 are mixed. And is supplied to the engine 1.

Therefore, the gas fuel 10 and the exhaust gas 15 do not mix in the space formed between the inner wall 21 and the body 19 of the Venturi mixer 32 due to the partition wall 33 provided in the Venturi mixer 32. The gas fuel and the exhaust gas do not flow back to one another due to the pressure difference when they flow into the space. Further, similarly to the first example, the gas fuel 10 and the exhaust gas 1
5 is sucked out from the ejection hole 26, the pressure loss of the mixed gas 29 can be reduced as compared with a case where a venturi mixer for gas fuel and a venturi mixer for exhaust gas are arranged in two stages. One venturi-type mixer 32 is sufficient, and the number of components can be reduced. Therefore, the overall size is reduced, the mountability on a vehicle is good, and the manufacturing cost can be reduced.

Further, the number of the injection holes 26 formed in each Venturi mixer 32 is changed, and the gas fuel metering valve 14 and the exhaust gas metering valve 17 are adjusted to adjust the mixed gas 29.
The mixing ratio of the intake air 27, the gaseous fuel 10, and the exhaust gas 15 is changed, and the exhaust gas 15 of the mixed gas 29 suppresses the combustion of the fuel in the engine 1, thereby lowering the combustion temperature and reducing the generation of NOx. The same is true.

The venturi-type mixer 30 and the venturi-type mixer 32 of the present invention are not limited to the above-described embodiment, but are limited to the inner wall 21 as long as the flow rates of the gas fuel 10 and the exhaust gas 15 are adjusted. It goes without saying that the size, position, shape, and number of the ejection holes 26 may be provided in any manner, and that various changes may be made without departing from the spirit of the present invention.

[0041]

According to the Venturi type mixer of the present invention,
Various excellent effects can be obtained as described below.

I) According to the first aspect of the present invention, since the gas fuel and the exhaust gas are sucked out from the ejection hole by one venturi-type mixer, two venturi-type mixers for the gas fuel and the venturi-type mixer for the exhaust gas are used. Compared to the case of arranging in a row, the pressure loss of the mixed gas can be reduced and the number of parts can be reduced, so that the overall size can be reduced and the mountability on the vehicle is good, and the manufacturing cost is also reduced Can be.

II) According to the second aspect of the invention, the gas fuel and the exhaust gas are mixed in the space formed between the inner wall and the body of the Venturi mixer by the partition provided in the Venturi mixer. Therefore, the gas fuel and the exhaust gas do not flow back to one another due to the pressure difference when flowing into the space. Also, since gas fuel and exhaust gas are sucked out from the ejection hole by one venturi-type mixer,
Compared to a case where a Venturi-type mixer is arranged in two stages, the pressure loss of the mixed gas can be reduced, and the number of parts can be reduced with one Venturi-type mixer. As in the first aspect, the mountability is good and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a first example of an embodiment of a Venturi mixer of the present invention.

FIG. 2 is a view in the direction of arrows II-II in FIG.

FIG. 3 is a schematic configuration diagram of an engine and a pipe provided with the Venturi mixer of the present invention.

FIG. 4 is a vertical sectional side view showing a second example of the embodiment of the Venturi mixer of the present invention.

FIG. 5 is a schematic configuration diagram of an engine and a pipe when a conventional Venturi mixer is arranged in two stages.

FIG. 6 is a vertical sectional side view showing an example of a conventional case where Venturi type mixers are arranged in two stages.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 7 Intake pipe 10 Gas fuel 13 Gas fuel supply pipe 15 Exhaust gas 16 Exhaust gas supply pipe 19 Body 20 Internal space 21 Inner wall 24 Space 25 Hourglass space 26 Outlet 27 Intake 33 Partition wall 34 Gas fuel space 35 Exhaust gas space

Claims (2)

[Claims] A body provided with a gas fuel supply pipe and an exhaust gas supply pipe and having an internal space through which intake air passes is connected to an intake pipe on an intake side of an engine, and an intake air is introduced into the internal space from an intake inflow side. A cross section along the flow direction of the intake air toward the outflow side is provided with a drum-shaped inner wall, and a space into which gas fuel and exhaust gas flows and a drum-shaped space through which the intake air flows are formed between the inner wall and the inside of the body, and A venturi-type mixer, wherein an outlet for gas fuel and exhaust gas is provided in the narrowed inner wall portion of the hourglass space. 2. A body provided with a gas fuel supply pipe and an exhaust gas supply pipe and provided with an internal space through which intake air passes is connected to an intake pipe on the intake side of the engine. A cross section along the flow direction of the intake air toward the outflow side is provided with a drum-shaped inner wall, and a space into which gas fuel and exhaust gas flows and a drum-shaped space through which the intake air flows are formed between the inner wall and the inside of the body, and In the narrowed inner wall portion of the hourglass space, a jet hole for gas fuel and exhaust gas is provided to the hourglass space, and further in a space provided between the inner wall and the inside of the trunk,
A partition partitioning the space into a space for gas fuel and a space for exhaust gas is provided, and a gas fuel supply pipe and an exhaust gas supply pipe are provided in the body so that the gas fuel flows into the gas fuel space and the exhaust gas flows into the exhaust gas space. A venturi-type mixer characterized by being connected.