JPS58122352A - Method for supplying two sorts of fuel in internal-combustion engine - Google Patents

Abstract

PURPOSE:To use two sorts of fuels, for better performance of engine operation, without changing much the fuel supply system designed for single sort fuel by cooling the mixture of petroleum and alcoholic fuels after measuring and putting it in the state of two-phase segregated zone. CONSTITUTION:Fuel tanks 1 and 2 contain a petroleum fuel such as light oil and an alcoholic fuel such as ethanol, respectively, in the liquid phase. An electric heater 15 heats these two types of fuels flowing in a common duct 13 above their respective dissolution temperatures. A fuel injection pump 14 is equipped with two or more fuel outlets 20 which are connected to a fuel injection nozzle 22. On the midway of duct 21 a cooling device 23 is furnished, in which the mixture of these two types of fuels is cooled below either of the dissolution temperatures which is lowest.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for supplying dual fuel to an internal combustion engine, particularly a diesel engine, and more specifically to a method for supplying dual fuel, petroleum-based fuel and alcohol-based fuel, to the internal combustion engine. Regarding the method.

It has been considered to use petroleum-based fuels such as light oil and alcohol-based fuels such as ethanol in diesel engines. Petroleum-based fuels have a cetane number suitable for diesel engine fuel oil, and have the ignitability required for normal diesel engine operation, but alcohol-based fuels have a cetane number suitable for diesel engine fuel oil. The cetane value is extremely low, and it does not have the ignitability required for normal diesel engine operation. The cetane number of a solution of petroleum-based fuel and alcohol-based fuel is determined depending on the mixing ratio of petroleum-based fuel and alcohol-based fuel, and this cetane number is necessarily lower than that of petroleum-based fuel. The higher the percentage, the lower it becomes. For this reason, it is generally impossible to use two types of fuels, petroleum-based fuel and alcohol-based fuel, as fuel oil for diesel engines due to the lack of cetane number in the dissolved liquid.

For this reason, conventionally, when using the above-mentioned two types of fuel,
Petroleum-based fuel and alcohol-based fuel are each stored in separate fuel tanks, and the petroleum-based fuel and alcohol-based fuel are pumped from each fuel tank using two fuel meters such as fuel injection pumps.
Each fuel is injected into the internal combustion chamber through two fuel injection nozzles. It is considered that the two fuels may be injected into the diesel engine individually, or the two fuels may be mixed after metering and then injected into the diesel engine as a two-phase separated liquid through a single fuel injection nozzle. In this case, droplets of petroleum-based fuel and droplets of alcohol-based fuel are supplied to the diesel engine in a state where they are individually dispersed, so that the petroleum-based fuel with a high cetane number is first compressed and ignited, and the petroleum-based fuel The highly flammable alcohol-based fuel is ignited by the flame of the alcohol-based fuel,
Good combustion takes place.

However, this fuel supply method requires two fuel injection pumps, which makes the fuel supply system for the internal combustion engine complicated and expensive, and because of the difference in metering accuracy between the two fuel injection pumps, the mixture is always kept constant. It is difficult to supply a proportion of dual fuel to an internal combustion engine.

In addition, in order to modify the mixing ratio of two types of fuel, it is necessary to use two fuel injection pumps whose metering characteristics can be changed, and when using two types of fuel, it is necessary to use a single fuel injection pump such as petroleum-based fuel. It is necessary to significantly change the fuel supply system that uses the fuel.

The present invention effectively utilizes the fact that two types of fuel exhibit a dissolved liquid and a two-phase separated liquid depending on the temperature. The object of the present invention is to provide a new dual fuel supply method that allows dual fuel to be used as a good fuel oil for diesel engines.

According to the present invention, this purpose is to provide a method for supplying dual fuels of petroleum-based fuel and alcohol-based fuel to an internal combustion engine, and to bring the mixed liquid of petroleum-based fuel and alcohol-based fuel into a state in the dissolution region. metering with a fuel meter 1 @ 11, cooling the mixed liquid after measuring to bring the mixed liquid into a state of a two-phase separation region,
This is inside fsIIll! This is accomplished by a two-way fuel supply method.

According to this method, since the measurement of the two types of fuel, petroleum-based fuel and alcohol-based fuel, is carried out in the state where the two types of fuel are in the dissolution region, the two types of fuel can be measured using one fuel metering device. When supplied to the internal combustion engine, the two types of fuel are supplied as a two-phase separated liquid, and the sedan value of petroleum-based fuel ensures the ignitability required for normal diesel** operation. be done. In addition, with this method, it is possible to store petroleum fuel and alcohol fuel in the melting region in the fuel tank, and in this case, only one fuel tank is required, compared to the conventional method. Two types of fuel can be supplied by simply adding a cooling device to the single fuel fuel supply system.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

FIG. 1 shows one embodiment of a dual fuel supply system implementing the dual fuel supply method according to the present invention. This dual fuel supply device has two fuel tanks 1 and 2,
Fuel tank 1 stores petroleum-based fuel such as diesel oil, and fuel tank 2 stores petroleum-based fuel such as diesel oil.
The fuel tank stores alcoholic fuels such as ethanol, t-butyl alcohol (TBA), methyl-t-butyl ether (MTBE), and methanol in liquid phase.

The fuel tanks 1 and 2 are provided with fuel outlet pipes 3.4. The fuel outlet pipe 3 is connected to the common conduit 13 via the flow control valve 5, the conduit 7, the fuel filter 9, the conduit 1'1, and the fuel outlet J4 is connected to the flow control valve 6, the conduit 8, the fuel filter 10. It is connected to a common conduit 13 via a conduit 12 that extends. The common field 1113 is connected to the fuel intake port 19 of one fuel injection pump 14. An electric heater 15 is provided in the middle of the common conduit 13, and the cough electric heater 15 is selectively supplied with current from a battery power source 16 via a switch 17. ! 13
The petroleum-based fuel and the alcohol-based fuel flowing through the tank are heated to a temperature higher than the melting temperature of both. switch 1
7 is configured to close in response to the temperature detected by the temperature sensor 18, that is, the fuel lrx after passing through the electric heater.

The fuel injection pump 14 is provided with a plurality of fuel discharge ports 20. It is connected to a fuel injection nozzle 22 via 21. The fuel injection nozzle 22 is normally attached to a diesel engine (not shown) and is adapted to silently supply fuel to the Il chamber or main combustion chamber of the diesel engine.

A cold m@W, in this embodiment, a thermoelectric cooler 123 is installed in the middle of the conduit 21. The thermoelectric cooling unit 1123 is selectively supplied with current supplied by the battery unit 1124 via the switch 25, and is configured to cool the mixed liquid 6- of petroleum-based fuel and alcohol-based fuel flowing through the conduit 21 to below the melting temperature of both. It has become. The switch 25 opens and closes in response to the temperature detected by the ml sensor 26, that is, the m degree of fuel passing through the cooler.

According to the present invention, since the two types of fuels, petroleum fuel and alcohol fuel, are measured in a state in which they are in the melting region, they can be accurately measured using one fuel injection pump and are not supplied to the internal combustion engine. Since the fuel is supplied in a two-phase separation state when the fuel is separated, the necessary ignitability of the fuel as a diesel engine fuel oil is ensured.

In this fuel supply method, the mixing ratio of the two types of fuel can be adjusted freely and reliably by the control valves 5 and 6.

FIG. 2 shows another embodiment of a dual fuel supply system for carrying out the dual fuel supply method according to the present invention. In FIG. 2, parts corresponding to those in FIG. 11 are indicated by the same reference numerals as in FIG. 1. In this dual fuel supply @stomach, two fuels, petroleum fuel and alcohol fuel, are stored in one fuel tank 30 in a predetermined mixing ratio in a dissolution range. This fuel tank 30 is provided with a fuel take-off pipe 31, which is connected to the fuel intake port 19 of the fuel injection pump 14 via a fuel filter 32 and a conduit 33.

In this embodiment as well, the type 2 fuel is measured in a state in which it is in the melting range, and internal combustion is achieved! When supplied to the I-channel, it is supplied in the state of a two-phase separation region, and the same effects as in the above-mentioned embodiments can be obtained.

In this embodiment, not only the fuel injection pump but also the fuel tank can be combined into one, and two types of fuel can be well supplied by simply adding a cooling @ stomach to the conventional single-fuel fuel supply system. I can do it.

The melting temperature of the two types of fuel changes depending on the mixing ratio of petroleum fuel and alcohol fuel. Figure 3 shows the solubility characteristics of two types of fuel: diesel oil and ethanol. When the mixing ratio of light oil and ethanol is 2:8, it is in the melting range at room temperature, that is, 20°C. In the embodiment shown in FIG. 2, it is necessary to maintain the temperature inside the tank above the melting temperature of the two types of fuel so that the two types of fuel are in the melting region within the fuel tank. If there is a risk that the temperature will drop below the temperature, the fuel tank 30 may be provided with an appropriate heating device.

Although the present invention has been described in detail above with reference to specific embodiments, it is understood by those skilled in the art that the present invention is not limited thereto, and that various embodiments can be made within the scope of the present invention. It would be obvious for

[Brief explanation of the drawing]

Figures 1 and 2 are schematic configuration diagrams showing an embodiment of a dual fuel supply device used to carry out the dual fuel supply method according to the present invention, and Figure 3 is a dissolution of dual fuel of light oil and ethanol. It is a graph showing characteristics. 1.2...Fuel tank, 3,4...Fuel removal pipe, 5
゜6...Flow rate control valve, 7.8...Conduit, 9.10-
Fuel filter, 11.12... conduit, 13... common conduit. 14... Fuel injection pump, 15... Electric heater, 1
6...Battery power supply, 17-...Switch, 18...
- Temperature sensor, 19... Fuel intake 0.20... Fuel discharge 0.29- 1... Conduit, 22... Fuel injection nozzle, 23...
Thermoelectric cooler, 24... Battery power source, 25... Switch, 26...'aa sensor, 30... Fuel tank, 31... Conduit 32... Fuel filter, 33 River conduit patent applicant Toyota Automatic Kushi Industries Co., Ltd.
Patent Attorney Takeshi Akishi 10-

Claims (1)

[Claims] Internal combustion of two types of fuel: petroleum-based fuel and alcohol-based fuel 11
In this method, the mixed liquid of petroleum fuel and alcoholic fuel is measured by a fuel metering device in a state in the dissolution region, and after the measurement, the mixed liquid is cooled and the isthmus mixture is separated into one phase. This is a two-type fuel supply method that supplies this to an internal combustion engine.