JP2007204600A - Apparatus for producing and feeding emulsion fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing and feeding an emulsion fuel, making anxiety of water separation, and a storage tank inevitably required in a batch treatment unnecessary on the structure, and enabling the miniaturization; and to provide a feeding method. <P>SOLUTION: The apparatus for producing and feeding the emulsion fuel is constituted as follows. A raw material 10 is charged from a raw material tank 11 to a mixing vessel 14 by a feed pump 12, and a mixed fluid 13 obtained by mixing water 10a, an emulsifier 10b and a light oil 10c is made. The mixed fluid 13 is sent to an emulsifier 3 by a pump 15 to provide the emulsion fuel 8, and emulsion fuel 8 is fed to an engine 2 by a fuel pump 4. A pipe connected to the mixing vessel 14 through a relief valve 5 is installed in the midway of the pipe between the emulsifier 3 and the engine 2. The light oil tank 11c is connected by a pipe branched at the midway of the pipe to the mixing vessel 14, to a feed valve 6 of a three-way valve present just before the fuel pump 4 to enable the fuel to be properly switched between the pure light oil 10c and the emulsion fuel 8 at the start or stop of the apparatus 1. The feeding method is also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an apparatus for producing and supplying an emulsion fuel of water and fuel oil, which is a fuel for a combustion apparatus such as a diesel engine.

In recent years, exhaust gas regulations from internal combustion engines including diesel engines have been strengthened year by year due to increasing awareness of environmental protection. The automobile NOx / PM method is one example. Diesel engines have higher thermal efficiency than gasoline engines, and should have a lower environmental impact and match the needs of the times. However, in general, diesel engines are regarded as a problem in Japan and the United States because they emit large amounts of nitrogen oxides and black smoke (particulate suspended matter).

Nitrogen oxides cause photochemical smog and acid rain, and have been pointed out to the human body, especially the respiratory system. As a technique for suppressing the generation of nitrogen oxides, there is a method of delaying the fuel injection timing in the engine. It is known that this method increases the emission amount of particulate suspended matter in a trade-off relationship. When an auxiliary machine can be added to the engine or when a large change is allowed, an exhaust gas recirculation system, a high-pressure fuel injection system, and the like can be considered.

Under such circumstances, emulsion fuel has been demonstrated as the only technology that can simultaneously reduce nitrogen oxides and particulate suspended solids. Emulsion fuel is obtained by adding water and a surfactant (hereinafter referred to as an emulsifier) to fuel and uniformly dispersing and stabilizing the fuel. Due to the presence of water in the fuel, the combustion temperature in the engine is suppressed, and the generation of nitrogen oxides caused by the thermal dissociation of nitrogen and oxygen in the air, which is normally generated in fuel, is suppressed. As a mechanism for reducing particulate suspended solids, the boiling point of water is lower than the ignition point of fuel oil in the compression process of the diesel cycle. There is also the theory that composting is promoted and unburned is less likely to occur.
Patent Publication 2002-294260 Patent Publication 2004-67913

The biggest challenge in spreading emulsion fuel is the separation of water. Since it is a liquid mixture of water and fuel oil that does not normally mix, it is inevitably lacking in stability and there is a concern about separation of moisture. Water separation must be avoided due to problems such as engine shutdown and corrosion. Most of the emulsion fuel production machines that have been put on the market in the past are batch treatments in which water and fuel oil are supplied in a fixed amount to the tank, and then stirred and emulsified. This is a method of refueling.

However, in the case of use where the annual working days are only a few days during the harvest period, as in the case of a combine in an agricultural machine, the conventional method of replenishing emulsion fuel to the light oil tank as it is is supposed to separate the tank or piping. The In addition, some types of fuel filters for internal combustion engines have a function of removing water and are difficult to use for engines having such filters.
Emulsion fuel can be used not only as a diesel engine but also as a fuel for a continuous combustor such as a boiler burner if the fuel oil type used as a raw material is changed to the oil type of the original burner. The effect has been confirmed.

It is difficult to say that the above-described conventional emulsion fuel production apparatus by batch processing and its fuel supply method are apparatuses that can be used with peace of mind due to concerns about water separation. Also, as a countermeasure, even if an emulsion fuel production device is mounted on the vehicle and only the required amount of fuel is produced, since the batch processing is performed, it corresponds to the time required to produce one batch. It is necessary to store the maximum fuel consumption of the engine somewhere, and it is not realistic to increase the size of the device and mount it on the vehicle. Therefore, it is necessary to change the system from batch processing to continuous processing, but it is difficult to achieve a stable mixing ratio of water and oil in continuous processing. For example, if a continuous process is constructed with a tankless system, even if a metering pump is used, the metering cannot be ensured due to fluctuations in the internal pressure of the pipe, and the mixing ratio varies due to variations in the discharge rate, resulting in stable combustion. Absent.

Next, even if a continuous emulsion fuel production apparatus can be realized, if starting and stopping with only emulsion fuel, the concern of water separation at the time of long-term stop has not been completely wiped out. However, in the normal fuel system line, it is usual to supply the fuel excessively, install a return circuit and return it to the tank, and even in the case of emulsion fuel, water separation is almost as a result of flow by the pump. No longer. Eventually, the fuel is stationary and the possibility of water separation remains in the engine downstream of the return circuit. However, the water separation inside the engine at the time of long-term stop cannot be wiped out by the existing system.

In order to realize a continuous processing system using a metering pump, the pressure on the discharge side of the pump may be stabilized. Therefore, if a small tank (reservoir) is prepared in the circuit as in the batch type, and this is opened to the atmosphere or maintained at a constant pressure with a relief valve, back pressure will be applied to all metering pumps supplied here. Quantities can be secured. At this time, it is not necessary to use a metering pump for all the raw materials.For example, the fuel oil is supplied by a head, the flow rate is picked up by a flow meter, and the discharge amount of water and emulsifier is controlled by feedback control using the metering pump. It is also possible to control. Moreover, the emulsifier is a small amount of about 0.01% to 5.0% with respect to the total amount, and complete synchronous control is not necessary, and the time required for consuming the fuel of one third of the tank control capacity is less than If it supplies during, it will be enough.

In order to eliminate water separation of the emulsion fuel remaining inside the engine, it is sufficient that the emulsion fuel does not remain inside the engine. In other words, when a signal for engine termination processing by key-off operation is received, the fuel supply pipe is automatically switched to fuel oil, the return side is piped to the aforementioned tank, and the fuel consumption time at idling is calculated until the fuel is switched. And stop the engine with a timer. The description here assumes an engine, but the same applies to a continuous combustion apparatus such as a burner.

According to the present invention, a continuous emulsion fuel production machine can be realized, and a storage tank that is absolutely necessary in the conventional batch processing type is not necessary in terms of structure, and accordingly, the size can be reduced accordingly. As a result, it is possible to produce and supply only the necessary amount of emulsion fuel while running on a vehicle, and it is possible to eliminate concerns about water separation. Furthermore, since the structure of the tank and the like are simplified and electrical control is simplified, the manufacturing cost can be reduced. These effects are also significant in terms of cost and size in the continuous emulsion fuel production apparatus of the present invention even for a diesel engine for in-house power generation with a displacement exceeding 10,000 cc installed in a factory or the like. is there. As a result, the spread of emulsion fuel becomes possible, and the generation amount of nitrogen oxides and particulate suspended solids, which are the effects of emulsion fuel, can be reduced, thereby contributing to the suppression of environmental pollution.

Hereinafter, an emulsion fuel production and supply apparatus (this apparatus) 1 which is an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to this. In this embodiment, a diesel engine having a displacement of 2000 cc or less is assumed as a combustion device, and a continuous emulsion fuel production and supply device that can be mounted on a vehicle equipped with the diesel engine is assumed.

FIG. 1 is a diagram illustrating the configuration of the apparatus 1. That is, the water 10a, the emulsifier 10b, and the light oil 10c used as the raw material 10 of the emulsion fuel 8 are stored in the raw material tank 11 (the water tank 11a, the emulsifier tank 11b, and the light oil tank 11c, respectively). The light oil tank 11c can share the fuel tank of the vehicle. From each raw material tank 11, a pipe for supplying the raw material 10 to the mixing tank 14 in which the raw material 10 is mixed and a supply pump 12 are installed, and the raw material 10 is charged into the mixing tank 14 in an amount corresponding to the operation. A mixed fluid 13 in which is mixed is produced. In addition, a liquid level sensor 16 is installed inside the mixing tank 14, and when the liquid level sensor 16 is activated when a certain amount of the mixed fluid 13 is produced, the supply pump 12 stops its operation, and the mixed fluid 13 It is not made.

The mixed fluid 13 is sent to the emulsifying device 3 by the pump 15, and the mixed fluid 13 is emulsified by passing through the emulsifying device 3, and becomes the emulsion fuel 8 and sent to the engine 2 by the fuel pump 4. The piping connecting the emulsifying device 3 and the engine 2 is branched in the middle, and when a certain pressure is applied, a piping connecting to the mixing vessel 14 via the relief valve 5 that opens only in the direction of the mixing vessel 14 from the emulsifying device 3 is set. Has been. The light oil tank 11 c branches off in the middle of the piping to the mixing tank 14, and is connected to the fuel pump 4 through a supply valve 6 that is a three-way valve immediately before the fuel pump 4. Further, when the fuel supply to the engine 2 is excessive, a branch is provided between the fuel pump 4 and the engine 2 in order to return the fuel to the light oil tank 11c or the mixing tank 14, and branch from the fuel pump 4 side. The pipe is connected to the light oil tank 11c or the mixing tank 14 via a return valve 7 which is a three-way valve.

Next, the actual operation of this embodiment will be described. FIG. 2 shows the flow of fuel and the like during operation of the present embodiment. The emulsion fuel 8 maintains a stable emulsified state at the time of manufacture, but the state becomes unstable after a certain period of time, and in some cases, it is separated into water 10a, emulsifier 10b, and light oil 10c as raw materials. It may end up. If this is the case, it cannot be said that the engine 2 is suitable for starting, and the engine 2 may even be damaged in some cases. Therefore, it is preferable to start with pure light oil 10c only at the time of starting.

First, when the present apparatus 1 is started, the light oil 10c and the like move only at the thick line portion shown in FIG. 2A. That is, the supply valve 6 opens only in the direction of the light oil tank 11c → the engine 2, and the light oil 10c supplied from the light oil tank 11c flows in the direction of the arrow shown in the drawing and is sent to the engine 2 by the fuel pump 4, The engine 2 is started with light oil 10c having a purity of 100%. At this time, the return valve 7 opens only in the direction of the engine 2 → the light oil tank 10c, and the excessively supplied light oil 10c is returned to the light oil tank 11c. On the other hand, since it is expected that the emulsion fuel 8 remaining at the previous start-up remains in the state separated in the pipe as described above, when the emulsion fuel 8 is manufactured and sent out by operating the pump 15. Since the supply valve 6 is closed in the direction of the mixing tank 14 → the engine 2, it is returned to the mixing tank 14 through the relief valve 5.

When the operation of starting the engine 2 and returning all the separated emulsion fuel 8 in the pipe to the mixing tank 14 is completed, the operation state shown in FIG. 2B is subsequently shifted. During normal operation, the supply valve 6 opens only in the direction of the mixing tank 14 → the engine 2 and the return valve 7 opens only in the direction of the engine 2 → the mixing tank 14, respectively, and moves only at the thick line portion shown in FIG. 2B. That is, each raw material 10 is sent to the mixing tank 14 by the respective raw material pump 12 to form the mixed fluid 13 to the extent that the liquid level sensor 16 reacts. The mixed fluid 13 is sent to the emulsifying device 3 by the pump 15 to be emulsified, and the produced emulsion fuel 8 is sent to the engine 2 via the fuel pump 4, and the excess supply is returned to the mixing tank 14. Of course, if the liquid level sensor 15 does not react, the mixed fluid 13 in the mixing tank 14 is insufficient, and each raw material 10 is charged at a constant rate until the liquid level sensor 15 reacts again. . The mixed fluid 13 has already been emulsified to some extent by being sent out by the pump 15, and there is no problem in use as an emulsion fuel even if the emulsifying device 3 is not installed in some cases.

When the present apparatus 1 is stopped, as described above, if the emulsion fuel 8 remains in the pipe, the emulsion fuel 8 is separated and a problem occurs in the next start. Therefore, the emulsion fuel 8 remaining in the engine 2 and in the pipe immediately adjacent to the engine 2 is generated. Must be replaced with pure light oil 10c. Therefore, as shown in FIG. 3C, the supply valve 6 is opened only in the direction of the light oil tank 11c → the engine 2 and the return valve is opened only in the direction of the engine 2 → the mixing tank 14, and the light oil 10c is fed directly from the light oil tank 11c to the engine 2. At this time, if the light oil 10c becomes excessively supplied, it is returned to the mixing tank 14. This is to prevent the emulsion fuel 8 from entering the light oil tank 11c. At this time, the light oil 10c is mixed in the mixing tank 14, and if the amount of the returned light oil 10c is unknown, a mixed fluid 13 that is rich in the light oil 10c is produced. There is no problem with the combustion of the fuel 8.

2A to 2C, the apparatus 1 can switch the fuel to the pure light oil 10c and the emulsion fuel 8 in a timely manner, and can stably start the engine 2 and discharge environmental pollutants during normal operation. Can be suppressed. Further, for example, by installing a sensor for detecting the load of the engine 2 and the accelerator opening and performing feedback control on the discharge amount of the pump, the oil-water ratio of the emulsion fuel 8 can be dynamically proportionally controlled.

It is a figure which shows the system of each component and piping of the emulsion fuel manufacture supply apparatus of a present Example. It is a figure which shows the operation condition at the time of operation | movement of each component and piping of the emulsion fuel manufacture supply apparatus of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 This apparatus 2 Engine 3 Emulsifier 4 Fuel pump 5 Relief valve 6 Supply valve 7 Return valve 8 Emulsion fuel 10 Raw material 10a Water 10b Emulsifier 10c Light oil 11 Raw material tank 11a Water tank 11b Emulsifier tank 11c Light oil tank 12 Raw material pump 12a Water pump 12b Emulsifier pump 12c Light oil pump 13 Mixed fluid 14 Mixing tank 15 Pump 16 Liquid level sensor

Claims (7)

An emulsion fuel production and supply device for producing an emulsion fuel using fuel oil, water and a surfactant as raw materials, and supplying the emulsion fuel to a combustion apparatus, comprising a small-capacity mixing tank to which a plurality of the raw materials are supplied, wherein the mixing An emulsion fuel production and supply device, wherein the mixed fluid of the raw materials supplied from the tank is emulsified to become emulsion fuel and then directly supplied to the combustion device. The emulsion fuel production and supply apparatus according to claim 1, wherein the volume of the mixed layer is not more than twice the maximum fuel consumption per minute of the combustion apparatus. When the relief valve is installed after the emulsifying device and the flow rate of the emulsion fuel supplied to the combustion device is greater than the consumption, the relief valve is operated to return the excess emulsion fuel to the mixed layer. The emulsion fuel production and supply device according to claim 1 or 2, characterized in that: 4. The emulsion fuel production and supply device according to claim 1, wherein the surfactant supply device supplied to the mixed layer comprises a constant capacity pump such as a trochoid pump and a stepping motor. After receiving a signal to stop the consumption of fuel, the piping path on the supply side is switched from the emulsion fuel to the fuel oil, and the emulsion fuel remaining in the combustion device is completely eliminated and replaced with pure fuel oil. 5. The emulsion fuel production and supply device according to claim 1, further comprising an automatic switching device for the piping path that automatically stops the supply of the fuel oil after the operation. 6. The feed rate of the raw material is feedback-controlled so that the operating condition of the combustion device is detected and the mixing ratio of the raw material is optimized to the load state of the combustion device. Emulsion fuel production and supply equipment. A method for producing and supplying emulsion fuel using fuel oil, water and a surfactant as raw materials and supplying the fuel to a combustion device,
During normal operation, the raw material is simultaneously supplied to a small-capacity mixing tank to form a mixed fluid, and the mixed fluid is supplied to an emulsifying device to be emulsified to become an emulsion fuel, which is then directly supplied to the combustion device.
When the operation is stopped, the supply of the raw material to the mixing tank is stopped, and the fuel oil is directly supplied to the combustion device so that the emulsion fuel in the combustion device and the piping is combusted and replaced with pure fuel oil. Stop
At the start of operation, the fuel oil is directly supplied to the combustion device to ensure stable startability, and the emulsification device is operated to start production of emulsion fuel for shifting to normal operation. A method for producing and supplying an emulsion fuel, wherein the separated emulsion fuel is returned to the mixing tank and then shifted to a normal operation.

Images