JPS6146659B2 - - Google Patents

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to a novel fuel supply device for supplying water/oil emulsion fuel to the combustion chamber of an internal combustion engine in a stable emulsion state. .

(b) Prior art: Traditionally, aqueous components (e.g., water or methanol aqueous solution) and fuel-based components (e.g., light oil, kerosene, heavy oil, volatile oil) are fed in fixed proportions into a mixer, where they are mixed into an emulsion. This fuel is further supplied to the carburetor, and the fuel comes out of the carburetor.
This pump circulates, circulates and mixes the fuel in the circulation line returning to the carburetor via a pump, during which time a portion of this fuel is drawn out from the carburetor and supplied to the fuel injection pump. A fuel supply system for an internal combustion engine made by
It is known as described in the publication No.

However, the water/oil volume ratio of the fuel to be combusted is
0.1 to 0.8 and the water droplet diameter is at least 20 microns or less, preferably 5 microns or less, and the conventional device described above is insufficient to stably maintain this state during fuel use. It was hot. In conventional devices, there is
This is because only the pump is involved, and this circulation pipe is attached to the carburetor in a closed circuit state, and the fuel supply pipe to the injection pump is separately attached to the carburetor. This is because the mixer separately provided in the raw fuel supply path to the fuel tank is not directly involved in the circulation of fuel in the above-mentioned fuel circulation pipe. Additionally, this results in a state in which water and oil are partially separated, and when fuel in this state flows into the injection pump, the separated water corrodes the wetted parts of the injection pump, reducing the life of the pump. There was also the problem of lowering the performance.

(c) Purpose and history of the present invention; The present inventor aimed to solve the problems of the above-mentioned conventional device, and first, in the raw fuel supply line in the above-mentioned conventional device, there was no circulation pipe. We decided to interpose the mixer, which is located separately, in the circulation pipe, and also interpose the fuel tank in the circulation pipe. Since the mixer performs a very large number of circulation movements, a stationary mixer that only requires a short length is used as the mixer, and a fuel tank is interposed in the circulation path.
The problem of circulating all the fuel stored in the tank in large quantities and maintaining a uniform emulsion state, which is not present in the above-mentioned conventional equipment, is solved by the problem that the fuel is circulated through the circulation pipe extremely many times. It has been discovered that this problem can be solved by interposing a static mixer and by leading the fuel to the injection pump through a circulation pipe before exiting the static mixer and returning to the fuel tank. The present invention has now been completed.

(d) Configuration of the present invention; In a fuel supply device for an internal combustion engine that supplies fuel to a combustion chamber of an internal combustion engine using an injection pump, a fuel tank that stores fuel consisting of water and oil, an emulsification pump, and a stationary The static mixer is connected in this order by a passage pipe to form a circulation path, and the passage pipe connecting the static mixer and the fuel tank is provided with a branch pipe, and the branch pipe is The stationary mixer is connected to the injection pump via a fuel supply pump, and the emulsification pump is operated to circulate the fuel from the fuel tank to the fuel tank via the emulsification pump and the static mixer. A fuel supply system for an internal combustion engine, characterized in that a part of the fuel immediately after leaving the fuel is led out from the branch pipe to the injection pump.

(e) Examples of the present invention; The present invention will be explained in more detail with reference to embodiments shown in the drawings.

FIG. 1 is a schematic diagram schematically showing one embodiment of the apparatus according to the present invention.

In FIG. 1, a fuel tank 1, a fuel pump 4, a first filter 5, an injection pump 6, a second filter 7, and an injection nozzle 8 are connected in series through a passage pipe 3. The first filter 5 and the injection nozzle 8 are connected to the fuel tank 1 through a return pipe 3. The fuel 2 in the fuel tank 1 is sent by the supply pump 4 to the injection pump 6 via the first filter 5 . Furthermore, it is pressurized by the injection pump 6,
It passes through the second filter 7 and is injected from the injection nozzle 8 into the engine combustion chamber. The fuel that overflowed from the first filter 5 and the injection nozzle 8 returns to the fuel tank 1 through the return pipe 3'.

On the other hand, a fuel tank 1, an emulsifying pump 9, and a static mixer 10 are arranged in this order, and these are connected by a passage pipe 11 to form a circulation path. A branch pipe 17 for branching from the circulation path located between the static mixer 10 and the fuel tank 1 and sending fuel to the injection nozzle 8 is provided at the branch point 12 and engaged with the fuel pump 4. . The fuel 2 stored in the fuel tank 1 is mixed with water, water, etc. at a filling station in advance.
Oil, emulsifiers, and other necessary additives are mixed and emulsified. However, the necessary components may be put into the fuel tank 1. The fuel 2 in the fuel tank 1 may maintain an emulsion state, but due to changes over time, the emulsion state may deteriorate and the fuel 2 may be separated into oil and water. Therefore, when operating an internal combustion engine, this fuel must be emulsified and dispersed into a stable emulsion. Therefore, when the internal combustion engine is operated, the emulsifying pump 9 is operated in conjunction with the internal combustion engine, and the operation of the pump 9 causes the fuel tank 1, the pump 9, and the static mixer 10 to be interposed in this order. The fuel 2 in the fuel tank 1 is circulated through the circulation path formed in this order. During this flow process, the fuel is subjected to emulsification and dispersion processing, and a portion of the fuel is led out from the static mixer 10 to the fuel injection pump 6 through the branch pipe 17. This derived fuel has just been sufficiently emulsified and dispersed and has reached a stable emulsion state.

Note that the flow rate of the fuel passing through the static mixer 10 is designed to be much faster than the flow rate in the passage pipe 3, which is 5 to 20 cm/s. Also,
If the emulsification pump is driven by the internal combustion engine, the circulation pipe system will always work effectively while the engine is in operation.

FIG. 2 is a graph showing the speed of fuel passing through the static mixer and the state of emulsification and dispersion.

The experiment shown in FIG. 2 was conducted as follows.

First, in this experiment, in the circulation path shown in Fig. 1, a static mixer consisting of five elements shown in JP-A-49-34656 were connected in series, and the composition of the fuel was as follows. Main ingredient is light oil,
Water/no volume ratio is 0.7, emulsifier/oil volume ratio is 0.5×
10 ^-2 , nonionic surfactant HLB as emulsifier
The value of is 5.5.

Note that the emulsion stabilization scale was shown as follows.

Transfer the emulsified and dispersed fuel to a 15 mm diameter test tube 1.
3 (see Figure 3), and after leaving it for 5 days, the values of a and b shown in Figure 3 were measured and expressed as separation rate (b/a x 100%). Here, b
is the value of the upper transparent phase 14, which is an oil layer formed by separation of the emulsion and is a transparent liquid. There is a dispersion layer 15 (value indicated by c) below the upper transparent layer.

When the stability of the emulsion is poor, the amount of water is
Naturally, when there is a large amount, the lower transparent phase 16 (value indicated by d)
appears, but here the separation rate (b/a×100
%) indicates the stability of the emulsion. The static mixer used in this experiment was the one disclosed in Japanese Patent Application Laid-Open No. 49-34656, but 2 to 8 elements connected in series can be effectively used. The number of feathers is 3 to 3 as shown in Publication No. 8290.
It can also be effectively used using 10 pieces. Of course, other known static mixers can also be used.

In addition, in the experiment shown in Figure 2, the emulsifier
Although we used oil with an HLB value of 5.5, heavy oil, light oil,
HLB is 4.0 to 8.0 as an emulsifier for kerosene and volatile oil.
It has been confirmed in another experiment that this is suitable.

When emulsion fuel is continuously subjected to emulsification treatment for a long period of time, the temperature of the fuel gradually increases, which may significantly impede the stability of the emulsion. Therefore, in such a case, it is preferable to operate the emulsification pump intermittently, and the intermittent time interval of the operation is as follows:
It is necessary that the phase separation time be shorter than the phase separation time until the fuel in the emulsion becomes substantially unusable. Intermittent operation can be accomplished by providing a clutch between the heat engine and the emulsifying pump, setting the time with a timer, and engaging and disconnecting the clutch electrically or mechanically. When the emulsification pump 9 is stopped, the fuel is sent to the injection pump 6 by the fuel supply pump 4, and the fuel 2 in the fuel tank 1 is sent to the branch pipe 17.
Do it through.

Furthermore, when the emulsifying pump is operated with generated power obtained from a heat engine, this can be achieved by intermittent use of the power using a timer.

Further, a mechanism may be added that detects the temperature of the emulsion fuel and temporarily stops driving the emulsification pump when the temperature reaches a set temperature or higher.

Furthermore, in the circulation path consisting of the fuel tank, emulsifying pump, and static mixer, a fuel cooling means, such as a heat radiation fin or a refrigerant jacket, or the passage pipe 11 is lengthened to form a surface area sufficient for heat radiation. It is also preferable to take such measures.

(f) Effects of the present invention; The present invention also includes a fuel tank interposed in the fuel circulation path system to circulate the entire fuel,
Therefore, by circulating the fuel many times and passing through the mixer many times, the mixer itself can be shortened by interposing a static mixer in the circulation system. It produces a mixing effect that is twice as many times as the number of circulation passes through the mixer, and a portion of the fuel that goes from the static mixer to the large-volume fuel tank.
Since it has a structure in which the fuel is led out from the circulation pipe to the injection pump, the entire fuel is maintained in a nearly uniform state, and the fuel heading to the injection pump is the same as the one in the tank that has just finished mixing in the static mixer. Because it is formed by drawing out a part of the fuel flowing in the pipe before it flows into a large-volume part, the water droplet diameter is extremely small and uniformly dispersed, which could not be achieved with the conventional equipment mentioned above. emulsion fuel can now be supplied to the injection pump,
In addition, separated water does not flow toward the injection pump, resulting in a significant effect that the life of the injection pump is extended.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram schematically showing an embodiment of a device according to the present invention. FIG. 2 is a graph showing the speed of fuel passing through the static mixer and the state of emulsification and dispersion. FIG. 3 is a front view for explaining the operation for determining the value indicating stabilization of the emulsion. 1: fuel tank, 2: fuel, 3: passage pipe,
3': return pipe, 4: oil supply pump, 5: first filter, 6: injection pump, 7: second filter,
8: injection nozzle, 9: emulsification pump, 10: static mixer, 11: passage pipe, 12: branch point, 17: branch pipe.

Claims (1)

[Claims] 1. In a fuel supply system for an internal combustion engine that supplies fuel to a combustion chamber of an internal combustion engine using an injection pump, a fuel tank that stores fuel consisting of water and oil, an emulsification pump, and a static mixer are used in this system. The static mixer and the fuel tank are connected in turn to form a circulation path, and the passage pipe connecting the static mixer and the fuel tank is provided with a branch pipe, and the branch pipe is connected to the fuel injection pump via a fuel pump. is connected to a pump, and while the operation of the emulsifying pump circulates the fuel from the fuel tank to the fuel tank via the emulsifying pump and the static mixer, the fuel immediately after leaving the static mixer is A fuel supply device for an internal combustion engine, wherein a portion of the fuel supply device is led out from the branch pipe to the injection pump.