JP2011032998A - Internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine capable of reducing fuel consumption and improving emission. <P>SOLUTION: The internal combustion engine includes: a fuel supply mechanism that supplies mixed fuel prepared by mixing fuel with water to each cylinder; and a hydrogen supply mechanism that supplies hydrogen to each cylinder. The fuel supply mechanism includes: a mixing tank 8 that stores therein the mixed fuel; mixers 18, 64, 82 that injects the mixed fuel in which fuel and water are mixed to the mixing tank 8; and a fuel pump 12 that supplies the mixed fuel in the mixing tank 8 to each cylinder. The hydrogen supply mechanism mixes intake air in an intake pipe with hydrogen and supplies the mixture to each cylinder. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an internal combustion engine that is operated by supplying a mixed fuel obtained by mixing water to a fuel to a cylinder.

  Conventionally, as described in Patent Document 1, when a mixed fuel obtained by mixing water with fuel is supplied to each cylinder, high frequency vibration is applied to the mixed fuel to make it ultrafine and the water supply amount is changed according to the operating state. A device that is controlled to improve exhaust gas purification is known.

JP 2004-76608 A

However, even these conventional devices are desired to further purify the exhaust gas and improve the combustion efficiency.
An object of the present invention is to provide an internal combustion engine that further purifies exhaust gas and improves combustion efficiency.

In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
In an internal combustion engine having fuel supply means for supplying a mixed fuel obtained by mixing water to fuel to a cylinder,
This is an internal combustion engine provided with hydrogen supply means for supplying hydrogen to the cylinder.

  The fuel supply means includes a mixing tank that stores the mixed fuel, a mixer that discharges the mixed fuel into the mixing tank, and a fuel that supplies the mixed fuel in the mixing tank to the cylinder. It is good also as a structure provided with the pump. Further, the hydrogen supply means may be configured to mix the intake air with hydrogen and supply it to the cylinder.

  The fuel supply device of the present invention can improve fuel consumption by supplying and burning fuel, water, and hydrogen in a mixed state without greatly changing the configuration and combustion method of a conventional internal combustion engine. At the same time, the emission can be improved.

1 is a schematic configuration diagram of an internal combustion engine as an embodiment of the present invention. It is a schematic block diagram of a fuel supply mechanism as this embodiment. It is an expanded sectional view of the 1st mixer of this embodiment. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is an expansion perspective view of the rectification fin of this embodiment. It is an expanded sectional view of the 2nd mixer of this embodiment. It is an expanded sectional view of the submixer of this embodiment.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 1 and 2, reference numeral 1 denotes an internal combustion engine body. In this embodiment, a 4-cylinder diesel engine is used as an example. Other cylinder numbers may be used.

  First, the fuel supply mechanism F as fuel supply means for supplying fuel to the internal combustion engine body 1 will be described. The internal combustion engine body 1 is provided with a fuel injection valve 2 for each cylinder (not shown), and the injection pump 14 injects the supplied fuel into each cylinder via each fuel injection valve 2.

  A fuel tank 4 for storing fuel and a water tank 6 for storing water are provided, and a mixing tank 8 is also provided. In this embodiment, JIS standard light oil is used as the fuel, but it is not limited to light oil, and JIS standard kerosene or heavy oil, in particular, A heavy oil may be used. In the case of a gasoline engine, gasoline may be used as fuel.

  The fuel mixture generated in the mixing tank 8 is connected to the injection pump 14 by the main fuel pump 12 through the filter 10. Fuel is injected from the injection pump 14 into each cylinder (not shown) via each fuel injection valve 2, and excess fuel is connected to the mixing tank 8 via a return pipe 16.

  The mixing tank 8 is provided with a fuel level sensor 17 for detecting the fuel level. The fuel level sensor 17 outputs the fuel level according to the vertical movement of the float 17a floating on the surface of the fuel.

  A first mixer 18 is provided inside the mixing tank 8, and a fuel supply pipe 20 connected to the fuel tank 4 is connected to the first mixer 18. Further, a water supply pipe 22 connected to the water tank 6 is connected to the first mixer 18.

  As shown in FIG. 3, the first mixer 18 has an inflow hole 28 connected to the fuel supply pipe 20 formed in the mixer body 24 (see FIG. 4). A ring-shaped swirl flow chamber 32 is formed in the mixer main body 24, and the inflow hole 28 is connected to the swirl flow chamber 32 from the tangential direction on the outer peripheral side of the ring-shaped swirl flow chamber 32.

  As shown in FIG. 3, a cylindrical vortex chamber 34 is formed in the mixer main body 24 so as to be concentric with the swirling flow chamber 32. The inner periphery of the vortex chamber 34 is formed in a circular shape, the swirl flow chamber 32 is formed larger in the radial direction than the vortex flow chamber 34, and the vortex flow chamber 34 is disposed inside the swirl flow chamber 32. The chamber 34 is partitioned by a partition wall 36. A large-diameter hole 38 that is connected to the swirl flow chamber 32 and the vortex flow chamber 34 and is larger in the radial direction than the swirl flow chamber 32 is formed. The lid member 39 inserted into the large-diameter hole 38 allows the swirl flow chamber 32 and One end side of the vortex chamber 34 is closed.

  The lid member 39 is in contact with the upper end surface 36a of the partition wall 36, and a plurality of narrow channels 42 are formed on the upper end surface 36a of the partition wall 36 to communicate the swirl flow chamber 32 and the vortex flow chamber 34 (see FIG. 5). . The narrow channel 42 is formed in a substantially circular arc shape, and when a fluid flows into the swirling flow chamber 32 from the inflow hole 28 from the tangential direction, a swirling flow is generated in the swirling flow chamber 32. The narrow channel 42 is formed so that the narrow channel 42 is in the same direction along the turning direction.

  A large number of the narrow channels 42 are formed at equal intervals on the upper end surface 36a of the partition wall 36, and in this embodiment, eight are formed. The fluid flows from the swirl flow chamber 32 into the vortex chamber 34 via the narrow channel 42, and the fluid It is comprised so that it may flow in in the state which turns and flows. In addition, the narrow channel 42 is formed to have a wide width on the inflow side of the swirl flow chamber 32, a narrow width on the outflow side of the vortex flow chamber 34, and further chamfered on the inflow side of the swirl flow chamber 32 of the narrow flow channel 42. The cross-sectional area is increased.

  On the other hand, a tapered hole 44 formed concentrically with the vortex chamber 34 is connected to the other end side of the vortex chamber 34, and the diameter-expanded side of the tapered hole 44 is substantially the same diameter as the vortex chamber 34. The tapered hole 44 is formed so that the diameter-expanded side of the tapered hole 44 is connected to the vortex chamber 34 so that the diameter of the tapered hole 44 decreases toward the tip of the tapered hole 44. A connection hole 45 is concentrically connected to the taper hole 44 on the reduced diameter side of the taper hole 44, and the connection hole 45 is connected to the suction side of the first fuel pump 48.

  The lid member 39 is provided with a cylindrical portion 56 protruding into the vortex chamber 34, and the cylindrical portion 56 is formed concentrically with the vortex chamber 34. The cylindrical portion 56 is formed to have a length that reaches the inside of the tapered hole 44, and a supply hole 57 that communicates with the tapered hole 44 is formed in the cylindrical portion 56. In addition, the supply hole 57 is formed concentrically with the vortex chamber 34 and is formed to penetrate the lid member 39, and the water supply pipe 22 is connected to the supply hole 57.

  A straightening fin 62 is provided on the outer periphery of the cylindrical portion 56 perpendicular to the axial direction of the vortex chamber 34 (see FIG. 5), and the straightening fin 62 is formed over substantially the entire outer periphery of the cylindrical portion 56. At the same time, the rectifying fins 62 protrude from the outer periphery of the cylindrical portion 56 so as to reach the inner periphery of the vortex chamber 34.

  The rectifying fins 62 are provided in the vicinity of the outlet of the narrow channel 42 to the vortex chamber 34. In this embodiment, the rectifying fins 62 include three blades 62a, 62b, and 62c. Each blade 62a, 62b, 62c is configured such that one end is slightly bent, and a gap is formed between each blade 62a, 62b, 62c.

  In addition, the bending of each blade 62a, 62b, 62c on one end side causes the fluid flowing into the vortex chamber 34 from the narrow channel 42 to be a vortex, but the fluid passes through the gap between the blades 62a, 62b, 62c. It is configured to flow and to form a fluid vortex appropriately. Further, the thickness t of the rectifying fins 62 is formed as thin as 0.1 to 0.2 mm, and the thickness t may be determined by experiments or the like.

  A second mixer 64 is provided in the mixing tank 8. As shown in FIG. 7, the second mixer 64 includes a mixer body 24 having the same structure as that of the first mixer 18 described above. . The connection hole 45 is connected to the suction side of the second fuel pump 66. A lid member 68 is inserted into the large-diameter hole 38 of the mixer main body 24, and one end sides of the swirl flow chamber 32 and the vortex flow chamber 34 are closed. The lid member 68 is provided with a cylindrical portion 56, and a supply hole 70 that communicates with the tapered hole 44 is formed in the cylindrical portion 56. Rectifying fins 62 are provided on the outer periphery of the cylindrical portion 56.

  The supply hole 57 is formed concentrically with the vortex chamber 34, and an air supply hole 72 and a water supply hole 74 communicating with the supply hole 57 are communicated with the lid member 68 through the restrictors 72a and 74a, respectively. Is formed. An air suction pipe 54 is connected to the air supply hole 72 (see FIG. 2), and the air suction pipe 54 is disposed above the fuel in the mixing tank 8. A water suction pipe 76 is connected to the water supply hole 74 (see FIG. 2), and the water suction pipe 76 is disposed in an opening in a recess 78 formed in the bottom of the mixing tank 8.

The discharge sides of the first fuel pump 48 and the second fuel pump 66 are connected to a discharge pipe 80, and the discharge pipe 80 is joined and connected to a submixer 82 provided in the mixing tank 8.
The submixer 82 has the same basic structure as the first mixer 18 and the second mixer 64 described above, and the same members as the first mixer 18 and the second mixer 64 are denoted by the same reference numerals. Detailed description is omitted. As shown in FIG. 8, in the submixer 82, the inflow hole 28 to which the discharge pipe 80 is connected is formed in the submixer main body 84.

  A swirl flow chamber 32 and a vortex flow chamber 34 to which the inflow hole 28 is connected are formed in the submixer body 84. A large-diameter hole 38 is formed in connection with the swirl flow chamber 32 and the vortex flow chamber 34, and one end sides of the swirl flow chamber 32 and the vortex flow chamber 34 are closed by the nozzle member 40 inserted into the large-diameter hole 38. . The nozzle member 40 contacts the upper end surface 36 a of the partition wall 36, and a plurality of narrow channels 42 are formed on the upper end surface 36 a of the partition wall 36.

  On the other hand, a tapered hole 44 formed concentrically with the vortex chamber 34 is connected to the other end side of the vortex chamber 34, and the diameter-expanded side of the tapered hole 44 is substantially the same diameter as the vortex chamber 34. The tapered hole 44 is formed so that the diameter-expanded side of the tapered hole 44 is connected to the vortex chamber 34 so that the diameter of the tapered hole 44 decreases toward the tip of the tapered hole 44.

  The nozzle member 40 is provided with a cylindrical portion 56 protruding into the vortex chamber 34, and the cylindrical portion 56 is formed concentrically with the vortex chamber 34. The cylindrical portion 56 is formed to have a length that reaches the connecting portion between the vortex chamber 34 and the tapered hole 44, and a connecting hole 58 that communicates with the tapered hole 44 is formed in the cylindrical portion 56. In addition, a tapered discharge hole 60 that communicates with the connection hole 58 and opens into the mixing tank 8 is formed. The connection hole 58 and the discharge hole 60 are formed concentrically with the vortex chamber 34, and the discharge hole 60 is provided so as to increase in diameter from the connection hole 58 side toward the outside.

  A straightening fin 62 is provided on the outer periphery of the cylindrical portion 56 so as to be orthogonal to the axial direction of the vortex chamber 34, and the straightening fin 62 is formed over substantially the entire outer periphery of the cylindrical portion 56. Is projected from the outer periphery of the cylindrical portion 56 so as to reach the inner periphery of the vortex chamber 34.

  Next, the intake mechanism A of this embodiment will be described. As shown in FIG. 1, the intake mechanism A of the internal combustion engine body 1 is provided with a flow meter 100 for measuring the flow rate of air taken into an intake pipe (not shown). Further, the intake mechanism A is provided with a hydrogen supply mechanism H as a hydrogen supply means. The hydrogen supply mechanism H supplies hydrogen from an unillustrated cylinder filled with hydrogen into the intake pipe, and the air and hydrogen Are mixed in advance and supplied to each cylinder. The hydrogen supply mechanism H is also provided with a flow meter 102 for measuring the flow rate of hydrogen added into the intake pipe.

  The supply amount of the hydrogen added by the hydrogen supply mechanism H expressed by the volume ratio with respect to the air is not particularly limited as long as it is within the combustion range in the internal combustion engine, but is 4.0 vol% or less outside the hydrogen flammability range. Preferably, a certain proportion of hydrogen may be added according to the air flow rate measured by the flow meter 100.

  In the present embodiment, the exhaust system of the internal combustion engine is provided with an exhaust gas analyzer 104 that analyzes exhaust gas discharged through an exhaust pipe (not shown). A generator 106 is connected to the output shaft of the internal combustion engine body 1, and a constant load 108 is connected to the output side of the generator 106. In addition, a wattmeter 110 that measures the power generated by the generator 106 is provided.

Next, the operation of the internal combustion engine of the present embodiment described above will be described.
When the first fuel pump 48 is driven, the first fuel pump 48 sucks fuel and water from the fuel tank 4 and the water tank 6 through the first mixer 18, respectively. Fuel flows into the first mixer 18 from the fuel supply pipe 20, and water flows into the first mixer 18 from the water supply pipe 22.

  In the first mixer 18, the fuel flows into the swirling flow chamber 32 through the inflow hole 28 by being sucked from the connection hole 45 by the first fuel pump 48. By flowing into the ring-shaped swirling flow chamber 32 from the tangential direction, the fuel becomes swirling flow along the shape of the swirling flow chamber 32. Then, it flows from the swirl flow chamber 32 into the vortex flow chamber 34 through the narrow channel 42. At this time, the total cross-sectional area of the plurality of narrow channels 42 is smaller than the cross-sectional area of the swirl flow chamber 32, and the fuel flow velocity increases. Further, since the cross-sectional area of the narrow channel 42 is gradually reduced, the flow rate of the fuel is increased.

  When fuel flows into the vortex chamber 34 from the narrow channel 42, a high-speed vortex is generated around the outer periphery of the cylindrical portion 56 in the vortex chamber 34. In the vortex chamber 34, the vortexed fuel flows through the gaps between the blades 62 a, 62 b, 62 c, and the vortex rotation around the cylindrical portion 56 is rectified by the rectifying fins 62.

  The swirled fuel flows into the tapered hole 44 from the vortex chamber 34, and water flows into the tapered hole 44 through the water supply pipe 22 and the supply hole 57. The fuel and water are mixed by the swirl of the fuel in the tapered hole 44 to generate a mixed fuel that is an emulsion fuel. This mixed fuel is sucked into the first fuel pump 48 through the connection hole 45 and is supplied from the first fuel pump 48 to the submixer 82 through the discharge pipe 80.

  The mixed fuel supplied to the submixer 82 also flows into the tapered hole 44 from the swirling flow chamber 32, the narrow flow channel 42, and the vortex flow chamber 34 in the submixer 82, and water is finely divided. The mixed fuel is discharged from the tapered hole 44 through the connection hole 58 in the cylindrical portion 56 and discharged from the discharge hole 60 into the mixing tank 8. In the vortex chamber 34 and the tapered hole 44, the fuel swirls as a high-speed vortex, and water is mixed with the fuel, so that the formation of fine water particles is promoted and mixed.

  When the fuel level sensor 17 detects the fuel level in the mixing tank 8 and exceeds a predetermined level, the drive of the first fuel pump 48 is temporarily stopped. On the other hand, when the second fuel pump 66 is driven, the second fuel pump 66 sucks the mixed fuel, water, and air in the mixing tank 8 through the second mixer 64. The mixed fuel in the mixing tank 8 flows into the swirl flow chamber 32 through the inflow hole 28 and flows into the tapered hole 44 from the narrow flow path 42 and the vortex flow chamber 34 as described above.

  Water or mixed fuel in the recess 78 flows into the tapered hole 44 through the water suction pipe 76, the water supply hole 74, and the supply hole 70. Air flows into the taper hole 44 through the air suction pipe 54, the air supply hole 72, and the supply hole 70. The water and air that have flowed into the tapered hole 44 are mixed with the fuel, water, and air by the swirl of the mixed fuel in the tapered hole 44, and an emulsion fuel containing air is generated. In addition, you may make it supply hydrogen simultaneously with air.

  The air becomes minute bubbles and is mixed with the vortex flow in the tapered hole 44 to generate a mixed fuel that is an emulsion fuel in which the minute bubbles are mixed. The mixed fuel is sucked into the second fuel pump 66 from the tapered hole 44 through the connection hole 45.

  The second fuel pump 66 supplies the mixed fuel to the submixer 82, and flows into the tapered hole 44 from the swirling flow chamber 32, the narrow channel 42, and the vortex chamber 34 in the submixer 82, and water and air are atomized. Then, the mixed fuel is mixed by the vortex flow in the tapered hole 44, and this mixed fuel passes through the connection hole 58 in the cylindrical portion 56 from the tapered hole 44 and is discharged into the mixing tank 8 from the discharge hole 60. In the vortex chamber 34 and the taper hole 44, the fuel swirls as a high-speed vortex, and water and air are mixed with the fuel, so that the atomization of water and air is promoted and mixed.

  The mixed fuel produced in the mixing tank 8 is supplied to the injection pump 14 by the main fuel pump 12 through the filter 10. The mixed fuel is injected from the injection pump 14 into each cylinder (not shown) via each fuel injection valve 2, and excess fuel is returned to the mixing tank 8 via the return pipe 16.

  On the other hand, air is sucked into the internal combustion engine body 1 through an intake pipe and supplied to each cylinder. At that time, hydrogen is premixed in the supplied air and supplied to each cylinder. The amount of air supplied is measured by the flow meter 100, and the supply amount of hydrogen is measured by the flow meter 102.

  The mixed fuel is injected into each cylinder from each fuel injection valve 2, and air in which hydrogen is mixed is supplied to each cylinder to operate the internal combustion engine body 1, and the mixed fuel is injected by injecting the mixed fuel into the cylinder. The atomized air inside promotes the combustion of fuel, and the water causes a slight explosion. Improvement in combustion efficiency improves fuel efficiency and combustion is performed at a low temperature, so that nitrogen oxides are reduced and emissions are improved.

  Further, hydrogen is the lightest molecule and is a substance excellent in combustibility and diffusivity, and high combustibility and diffusivity is advantageous for efficient and complete combustion. Hydrogen molecule itself has a high energy content and has very good properties as a fuel. By adding hydrogen, combustion begins before fuel, leading to a good diffusion state of fuel in the cylinder, assisting combustion of fuel with poor flammability and diffusibility, and promoting combustion As a result, the combustion efficiency is improved and the emission is improved.

Next, experimental results by the internal combustion engine of the present embodiment will be described based on Tables 1 and 2.
As shown in Table 1, as the internal combustion engine body 1, an air-cooled four-cycle diesel engine was used, and diesel light oil was used as the fuel. An AC generator with a rated output of 2.0 kW was used as the generator 106, and the generator 106 was driven with a rated output and a constant load.

内燃機関本体１に供給する燃料、水、水素の組み合わせを変えて内燃機関本体１の運転状態を測定した。その結果を表２に示す。

The operating state of the internal combustion engine body 1 was measured by changing the combination of fuel, water, and hydrogen supplied to the internal combustion engine body 1. The results are shown in Table 2.

ここで、軽油消費量削減率は比較例１を基準にして算出し、発電効率は下記式により算出した。

Here, the light oil consumption reduction rate was calculated based on Comparative Example 1, and the power generation efficiency was calculated by the following equation.

Power generation efficiency = output energy amount / introduced energy amount
= Supplying fuel combustion heat (low heating value standard) / Power generation output
= {Supplying fuel combustion heat (low heating value reference) + Supplying hydrogen combustion heat (low heating value reference)} / Power generation output amount Comparative Example 1 is a fuel without adding water and hydrogen as in the conventional operation state. It shows the power generation efficiency and emission when operating with only the supply. Comparative Example 2 shows the power generation efficiency and emission when operated by adding 1.5 vol% of hydrogen by volume with respect to air. Comparative Example 3 shows the power generation efficiency and emission when the fuel oil is operated with a mixed fuel of 100 by mixing 98.6 mass% of light oil and 1.4 mass% of water by weight.

  In the embodiment, as described above, fuel, water, and hydrogen are added, hydrogen is added at a volume ratio of 1.5 vol% with respect to air, light oil is added at a weight ratio of 98.6 mass%, and water is added at a weight ratio of 1. This shows the power generation efficiency and emissions when operating with a mixed fuel of 100% mixed at 4 mass%.

  In Comparative Example 2, hydrogen is added to Comparative Example 1, but there is a difference in combustibility between the fuel gas oil and hydrogen, and hydrogen burns out before the gas oil burns well. There seemed to be no clear improvement in power generation efficiency or emissions. In Comparative Example 3, the fuel consumption, power generation efficiency, and emission were improved in comparison with Comparative Example 1 in the case of using a mixed fuel obtained by mixing water with fuel gas oil to make an emulsion fuel.

  On the other hand, in the examples, water and hydrogen are added to Comparative Example 1, but by mixing water, water acts as an intermediary for the combustion of fuel and hydrogen, and hydrogen combustion It is thought that water absorbed the thermal energy from the water and expanded as water vapor to promote the diffusion of light oil and improve the combustibility of light oil.

  As a result, fuel consumption, power generation efficiency, and emissions were further improved as compared with Comparative Example 3. In the embodiment, the light oil consumption reduction rate is about 23%, which means a reduction that greatly exceeds the amount of energy (combustion calorific value) of the supplied hydrogen. This is clearly shown in the fact that the power generation efficiency has been greatly improved.

  Therefore, in the example, it is considered that not only the light oil is replaced with hydrogen but the combustion efficiency of the fuel itself is improved. The addition of water also reduces the combustion temperature, which may lead to improved emissions.

  Fuel consumption can be improved and emissions can be improved by supplying and burning fuel, water, and hydrogen in a mixed state without significantly changing the configuration and combustion method of conventional internal combustion engines. it can.

  The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine body 2 ... Fuel injection valve 4 ... Fuel tank 6 ... Water tank 8 ... Mixing tank 12 ... Main fuel pump 14 ... Injection pump 16 ... Return pipe 18 ... First mixer 20 ... Fuel supply pipe 22 ... Water supply pipe 32 ... Swirl flow chamber 34 ... Vortex flow chamber 42 ... Narrow flow path 44 ... Tapered hole 48,66 ... Fuel pump 54 ... Air suction pipe 62 ... Rectifier fin 64 ... Second mixer 82 ... Submixer 100,102 ... Flow meter 104 ... exhaust gas analyzer 106 ... generator 108 ... load 110 ... watt meter

Claims (3)

In an internal combustion engine having fuel supply means for supplying a mixed fuel obtained by mixing water to fuel to a cylinder,
An internal combustion engine comprising hydrogen supply means for supplying hydrogen to the cylinder. The fuel supply means includes a mixing tank for storing the mixed fuel;
A mixer for discharging the mixed fuel into the mixing tank;
The internal combustion engine according to claim 1, further comprising a fuel pump that supplies the mixed fuel in the mixing tank to the cylinder. 3. The internal combustion engine according to claim 1, wherein the hydrogen supply means mixes the intake air with hydrogen and supplies the mixture to the cylinder.

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