JP2009203323A - Apparatus for producing emulsion fuel not containing emulsifying agent and operation method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing an emulsion fuel not requiring an emulsifying agent. <P>SOLUTION: The apparatus for producing an emulsion fuel comprises an oil feed line for feeding a fuel oil and water under pressure, a water feed line, a first ejector for joining the oil feed line and the water feed line, an emulsion fuel production part comprising a second ejector to be connected to the jet nozzle of the first ejector and a first mixer to be connected to the latter part of the jet nozzle of the second ejector, a cushion tank that is connected to the subsequent stage of the first mixer and temporarily stores the emulsion fuel, a bypass line that is returned from the cushion tank by way of an emulsion fuel pressure pump arranged at the subsequent stage of the cushion tank to the cushion tank itself, a return line connected to the bypass line and to the second ejector, and an emulsion fuel feed line connected from the cushion tank to the fuel feed part of a combustion apparatus. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an emulsion fuel production apparatus and an operation method thereof.

  Emulsion fuel is attracting attention as a fuel that can suppress the generation of soot and nitrogen oxides (NOX) while reducing the amount of fuel used by mixing water with fuel oil such as heavy oil.

  “Emulsion” refers to a dispersion solution in which both solute solvents are liquid, and is roughly classified into a water-in-oil emulsion (W / O emulsion) and an oil-in-water emulsion (O / W type). . In either case, fine particles (water droplets or oil droplets) having a particle size of about 0.1 to 10 μm are suspended in the solvent (oil or water). Since these fine particles diffusely reflect visible light and appear white and turbid like milk, the emulsion is called an emulsion.

  When an “emulsifier” is added to oil and water and stirred, a “water-oil emulsion” is formed which can stably maintain a dispersed state for a long time. An emulsifier is a kind of surfactant that disperses water molecules in fuel oil by chemical action. Many of the conventionally known emulsion fuels are generally formed by a chemical mechanism using an “emulsifier” (see Patent Documents 1 and 2, etc.).

  Patent Documents 3 to 4 describe a method in which fuel oil and water are supplied to a mixer without using an emulsifier and mixed, and the obtained emulsion fuel is immediately supplied to a combustion apparatus using a pump. Has been. However, in the case of the conventional method without adding an emulsifier (Patent Documents 3, 4, etc.), it is difficult to produce an emulsion fuel in which fine water is uniformly dispersed in fuel oil, even if fine water droplets are uniformly distributed. Even if a dispersed emulsion fuel is obtained, since no emulsifier is used, the water droplets aggregate and the water droplet diameter becomes non-uniform, and if supplied to the combustion device and burned, the combustion efficiency will deteriorate. It has been pointed out as a problem that black smoke is generated (Patent Document 2, third paragraph). That is, a method for producing a high-quality emulsion fuel that does not contain an emulsifier has been eagerly desired. Eventually, Patent Document 2 also adopts a method of mixing emulsifiers.

  However, not only does the price of the emulsion fuel increase as the emulsifier is added, but it has also been pointed out that the emulsifier itself has a serious adverse effect on combustion (for example, Patent Document 1, paragraph 4). Furthermore, if the emulsion fuel containing the emulsifier is continuously used in the combustion apparatus for a long period of time, there is a problem that the components of the emulsifier tend to accumulate deposits and scales called frog inside the combustion apparatus.

JP 2006-111666 A JP 2006-329438 A JP-A-5-157221 JP-A-10-185183

  One of the problems of emulsion fuel production technology without adding an emulsifier is to uniformly disperse the water particles in the fuel oil component without the aid of chemical action by the surfactant.

  In order to solve this problem, the present inventors have already applied water and fuel with an ejector having a special internal structure while independently pressurizing the water supply line and the oil (fuel oil) supply line by two high-pressure pumps. A new emulsion fuel production device (unit) has been successfully developed by combining oil and passing through a line mixer. According to this apparatus, it is possible to produce a high quality emulsion fuel in which water molecules are uniformly dispersed in the fuel oil without adding any emulsifier.

  However, since the emulsion fuel produced by this apparatus has a dispersion time of about several tens of seconds, it must be sent to the combustion apparatus before separation of fuel oil and water begins. For this reason, the above-described emulsion fuel production apparatus has a structure provided in the front stage of the fuel supply unit of the combustion apparatus. This is because when one unit is connected to many combustion devices, there is a problem that the supply of emulsion fuel cannot follow the sudden increase in load, such as when the combustion devices are started all at once.

  That is, since one fuel production device (unit) is designed to be attached to one combustion device, in order to operate a plurality of combustion devices, the same number of fuel production devices (units) as the combustion devices are required. It is necessary.

  The present invention has been made in view of the above, and provides a novel emulsion fuel production apparatus capable of supplying emulsion fuel without adding an emulsifier to a plurality of combustion apparatuses with a single fuel production apparatus. Is the main technical issue.

An emulsion fuel production apparatus according to the present invention joins an oil supply line that pressurizes and supplies fuel oil by an oil pump, a water supply line that pressurizes and supplies water by a water pump, and the oil supply line and the water supply line. An emulsion fuel production unit including a first ejector, a second ejector connected to the ejection port of the first ejector, and a first mixer connected to a subsequent stage of the ejection port of the second ejector; ,
Returned from the cushion tank to the cushion tank itself via a cushion tank that is connected to the subsequent stage of the first mixer and temporarily stores the emulsion fuel, and an emulsion fuel pressurization pump provided at the subsequent stage of the cushion tank. A bypass line connected to the bypass line, a return line connected to the second ejector and an emulsion fuel supply line connected from the cushion tank to a fuel supply part of a combustion device. It is characterized by that.

  The emulsion fuel production apparatus according to the present invention has an advantage that it can be easily attached to an existing boiler facility equipped with a plurality of combustion apparatuses, and one unit can be connected to a plurality of boilers.

A first heater may be provided on an annular piping path that connects the cushion tank from the return line and the first and second ejectors. For example,
It is conceivable to provide a method between the jet port of the second ejector and the first line mixer or between the water pump and the first ejector. This is because the mixing efficiency can be increased by setting the first heater to an appropriate temperature depending on the type of fuel oil (particularly viscosity).

  The cushion tank may include a second heater for keeping the emulsion fuel stored therein. This is because the separation of the emulsion fuel can be suppressed by maintaining the temperature in the cushion tank storing the emulsion fuel at a predetermined temperature.

  You may provide the 2nd line mixer in the back | latter stage of the said emulsion fuel pressurization pump. This is because mixing is performed again immediately before being sent to the combustion device, so that high-quality emulsion fuel can be reliably sent into the combustion device.

  When the position of the emulsion fuel level in the cushion tank is equal to or lower than the first set value, the operation method of the emulsion fuel production apparatus is configured to pass through the bypass line until the second set value is reached. Emulsion fuel is produced in the emulsion fuel production section while refluxing from the cushion tank to the cushion tank itself, and when the liquid level is equal to or higher than a second set value, the emulsion fuel production section in the emulsion fuel production section The production may be stopped and the emulsion fuel in the cushion tank may be controlled to return to the second ejector via the return line.

  In this way, a certain amount or more of fresh emulsion fuel is always secured in the cushion tank, so that the emulsion fuel can be stably supplied even when the combustion apparatus suddenly increases its load. become.

  According to the emulsion fuel production apparatus of the present invention, fresh emulsion fuel that does not contain an emulsifier is constantly circulated in the apparatus so that the emulsion fuel is always held in the cushion tank, so that one unit is connected to a plurality of combustion apparatuses. Even so, since the cushion tank ensures the supply of the emulsion fuel against the fluctuation of the load, the emulsion fuel can be stably supplied to each combustion device. Further, the emulsion fuel production apparatus according to the present invention can change the existing combustion apparatus from heavy oil fuel or the like to emulsion fuel. This can reduce the burden on the global environment as well as the fuel cost.

(Emulsion fuel combustion principle)
First, the combustion principle of the emulsion fuel mentioned in the present invention will be briefly described with reference to the drawings. In the present invention, since an emulsion fuel production apparatus applied to a combustion apparatus such as a boiler is assumed, fuel oil such as A heavy oil and soft water from which impurities are removed are used as starting materials. Wastewater generated from equipment may be used. The blending ratio is approximately 70 to 95%: around 5 to 30%. This ratio varies depending on the specific gravity and viscosity of the starting material, but is basically a water-in-oil emulsion (W / O emulsion) because it contains more oil.

  FIGS. 6 (a) to 6 (d) are transition diagrams schematically showing how the water-in-oil emulsion burns over time. The emulsion sprayed from the nozzle contains fine water droplets 101 in the fuel oil 100 (FIG. 6A). When the emulsion is sent into the combustion device in this state, the outer fuel oil component starts to burn (FIG. 6B). Then, the internal water begins to heat and expand (FIG. 6C). Finally, secondary fine particles are formed (this is referred to as “micro explosion”), and the oil droplet fine particles rapidly burn with an increased contact area with air (FIG. 6D).

  The combustion temperature is lowered by the heat of vaporization of the water contained in the fuel, and thus the amount of nitrogen oxide produced is reduced. Furthermore, since the finely divided fuel is rapidly burned completely, generation of exhaust particulates (PM) made of graphite, unburned carbon, or the like is suppressed.

(First embodiment)
-System configuration-
FIG. 1 is a conceptual diagram showing how the emulsion fuel production apparatus according to the first embodiment of the present invention is used. A broken line (a line connecting points A and B in the figure) indicates an existing pipe in which an oil tank 10 for storing fuel such as A heavy oil is connected to a plurality of burners 20 (20a to 20d). ing. This existing pipe is disconnected at point A and connected to the emulsion fuel production apparatus 30 according to the present invention. The emulsion fuel production apparatus 30 is connected to a water tank 40 for supplying water that is the second raw material of the emulsion fuel.

  As described above, the emulsion fuel production apparatus has an advantage that it can be installed on a relatively large existing heavy oil fuel boiler facility equipped with a plurality of combustion apparatuses without undergoing extensive modification. The plurality of combustion devices does not mean that a plurality of burner chips are provided in one combustion device, but means that a plurality of combustion devices controlled independently are connected.

  FIG. 2 is a system configuration diagram for explaining an internal system configuration of the emulsion fuel production apparatus. The output of the pump shown in the figure can be changed according to the frequency of the inverter, whereby the output during operation can be changed. A broken line indicates an electric signal line, and various operation controls such as quantitative control can be performed by centralized control using an operation panel, and data can be recorded and monitored.

  As shown in the figure, the combustion apparatus according to the present embodiment is roughly composed of an emulsion fuel production part and a cushion tank for storing the emulsion fuel.

Among these, the emulsion fuel production part has the following configuration, and in this part, emulsion fuel is produced using fuel oil and water as starting materials.
As shown in FIG. 2, a pipe connected to the oil tank 10 for supplying fuel oil, an oil supply line 12 including an oil pump (P1) 11 for pressurizing the fuel oil, a pipe connected to the water tank for supplying water, and water A water supply line 42 including a water pump (P2) 41 that pressurizes the first and second ejectors 50 and 60, a first heater 70, a first static mixer 80, and the like are connected through a pipe.

  The ejector is a member for colliding and mixing two fluids at high speed, and is a substantially T-shaped member having three openings communicating with each other, and has two inflow ports and one jet port. And. The first and second ejectors 50 and 60 shown in this embodiment are configured such that the pipe diameter (space diameter) changes abruptly inside.

  The internal space diameters of the first and second ejectors 50 and 60 are both wide in the vicinity of the two inflow portions, suddenly narrow in the interior, wide again in the junction, and wider in the ejection portion (exit side). It is comprised so that it may become. If a portion having a large inner diameter is an antinode and a portion having a small inner diameter is a node, a plurality of antinodes and nodes are continuously provided. Such a rapid change in the pipe diameter is thought to contribute to the homogenization of the emulsion fuel. For example, the portion of the node with the narrowest inner diameter is 0.5 mm or more and 3 mm or less, while the thick portion is about 2.1 mm to about 7.6 mm.

  Combined with pressurization at such an extremely high pressure and passing through the ejector and the line mixer in which the belly and the node are continuous as described above, a uniform emulsion fuel substantially without using an emulsifier. Can be manufactured.

  An oil supply line 12 for supplying fuel oil and a water supply line 42 for supplying water are connected to the two inlets of the first ejector 50 via check valves C4 and C2. A jet outlet of the first ejector 50 is directly connected to one of the two inlets of the second ejector 60, and a return line 100 described later is connected to the other outlet through a check valve C5. .

  In this embodiment, the first electric heater 70 is provided in the previous stage of the static mixer 80. However, the other parts (for example, the return line 100, the first and second ejectors 50, 60 are described later). It may be provided on a piping path connecting the cushion tank 90, an oil supply line, a water supply line, or the like. The electric heater 70 can be controlled at a constant temperature by a switch such as a thyristor, and is heated to a temperature of about 40 ° C. to 80 ° C. here. In addition, since heating temperature is determined by the kind (especially viscosity etc.) of oil, it is not limited to said range.

  FIG. 3 is a structural sectional view showing an example of the static mixer 80 in FIG. This static mixer 80 is a kind of line mixer in which a large number of elements (80A, 80B) are provided inside a cylindrical circular tube, and fuel oil and water are mixed while being separated each time they pass through the elements. .

  A cushion tank 90 is connected to the subsequent stage of the static mixer 80 via a control valve (SV3). The cushion tank 90 is a container that can store emulsion fuel production. Further, in the rear stage of the cushion tank 90, the emulsion fuel in the cushion tank 90 can be returned to the second ejector 60 via the emulsion fuel pressurizing pump (P3) 111, and the return line 100 and the cushion tank 90 can be recirculated. And an emulsion fuel supply line 120 through which the emulsion fuel is sent to the fuel supply section of the combustion apparatus 20 (20a, 20b,...). Further, as in this embodiment, a second line mixer is provided downstream of the emulsion fuel supply line 120. In this case, since mixing is performed again immediately before being sent to the combustion apparatus, it is possible to ensure that the emulsifier-free emulsion fuel that is separated over time is sent into the combustion apparatus.

  Also, various instruments and valves are provided on the piping, collecting various data such as the pressure, temperature and flow velocity of the fluid flowing in the piping, opening and closing various valves according to commands from the operation panel, and pumps The inverter frequency can be adjusted.

  As described above, the emulsion fuel in the present invention disperses fuel oil and water by the physical action of pressure and temperature, and does not include chemical stabilization means using a surfactant called an emulsifier. The dispersion stabilization time is relatively short.

  Therefore, when the emulsion fuel does not decrease in the cushion tank, in other words, when the state where the emulsion fuel is not consumed in the combustion device continues, if the emulsion fuel stays in the storage container for a long time, the fuel oil will increase with time. The problem arises that water and water begin to separate. Therefore, in order to maintain the dispersed state, the emulsion fuel that has not been used for a certain period of time after manufacture is returned to the second ejector 60 via the return line 100.

  In other words, when the fuel is not sent to the combustion device, the emulsion fuel is constantly circulated, so that it is newly stored in the cushion tank by a predetermined amount while being newly produced from the cushion tank.

  With such a mechanism, fresh emulsion fuel in the cushion tank is immediately supplied even when a plurality of combustion devices are started simultaneously.

  In addition, a level meter (liquid level gauge) is provided in the cushion tank, and when the amount falls below a predetermined amount, a new raw material is introduced from the emulsion fuel production department to increase the amount of emulsion fuel stored in the cushion tank. Constitute. At that time, the valves SV4 and SV8 are controlled so as to return from the cushion tank to the cushion tank itself via the bypass line 101.

  HH / H / L / LL shown in the cushion tank 90 in FIG. 2 indicates the state of the liquid level gauge in the cushion tank. HH generates a signal indicating an alarm contact (full water), H indicates a control contact (high level), L indicates a control contact (low level), and LL generates a signal indicating an alarm contact (low water).

  In order to suppress the temperature drop of the emulsion fuel, it is preferable to provide a second heater in the cushion tank or to increase the heat retention by using a heat insulating material or the like.

  In addition, although the static mixer was illustrated in FIG. 2, if it is a line mixer, another structure may be sufficient. Moreover, you may comprise so that the nano filter provided with the fine hole of a nanometer order may be provided in the back | latter stage of a line mixer. This is because the fuel oil and water are mixed more uniformly. The size of the pores depends on the type of emulsion fuel to be produced, but is preferably on the order of several tens of nm to several μm.

  FIG. 4A is a structural sectional view schematically showing another example of the line mixer. As shown in the figure, a configuration in which one or a plurality of mixing units having a cylindrical cross section are continuously provided with a pipe having a small inner diameter may be employed. Even in such a structure, the emulsion (50 + 80) shown in FIG. 2 is substantially used in that the emulsion produced by the ejector 50 and the emulsion refluxed from the return line 100 are mixed by the ejector 60 and mixed by the mixer. This is because the same effect as that of the product can be obtained.

The ejector and the static mixer do not necessarily have to be configured separately as illustrated in FIG.
FIG. 4B is a structural cross-sectional view showing a configuration example in which an ejector and a static mixer are connected to form an integrated structure. As shown in the figure, for each of the two inlets, two types of pipes having different inner diameters are continuously provided in two stages, and an integral member that connects the ejector outlet and the static mixer inlet. 61. Even in such a case, it can be considered that an ejector and a mixer are substantially provided.

(Second Embodiment)
-About operation method-
Next, an example of an operation method when the emulsion fuel production apparatus according to the first embodiment is connected to an existing boiler will be described. The control method described here is called a “quantitative control method”, but is merely an example and is not limited to this method.

  FIG. 5 is a sequence diagram for explaining an operation procedure during start-up and operation by the quantitative control method.

[1] During start-up and operation First, the oil pump 11 is started with a signal indicating that the liquid level gauge of the cushion tank 90 has reached a position below L as a start trigger.
2. Next, the water pump 41 is started with the fuel oil supply flow rate as a trigger.
3. Next, the mixing temperature of water / fuel oil is heated to 40 ° C. to 80 ° C. by the heater 70 to improve mixing efficiency. During production, the pump 111 constantly circulates in the cushion tank 90 via the bypass line 101 to prevent the dispersion liquid from staying.
[2] At the end The oil pump 11 is stopped using a signal indicating that the liquid level gauge of the cushion tank 90 has reached a position higher than H as a stop trigger.
5. After stopping the oil pump 11, the water pump 41 is stopped and a standby state is entered. During emulsion fuel production, the pump 111 always circulates in the emulsion production piping via the return line 100 to prevent the dispersion liquid from staying.

(Auxiliary function)
The flow rate, temperature, pressure, etc. of the fluid flowing in the pipes are monitored by meters 201-212 such as various flow meters, thermometers, pressure gauges, etc., and instantaneous values, integrated values, ratios, etc. are displayed and recorded. You may go. For example, it is useful for initial flow rate adjustment and maintenance by storing various data for one week every 30 minutes in the flash ROM inside the control PLC. Specifically, the fuel oil flow rate, water flow rate, emulsion fuel production flow rate, boiler supply flow rate, oil pump inverter frequency, water pump inverter frequency, emulsion fuel production pressure, and the like. In addition, the fuel oil or water supply flow rate may be monitored and an alarm may be issued in the event of an abnormality or a safety valve may be operated.

  The emulsion fuel production apparatus according to the present invention can be implemented as an additional facility that can be easily connected to an existing boiler facility, and the emulsion fuel obtained by this device does not require an emulsifier, and thus has an effect of reducing fuel costs. Be expected. Therefore, since the emulsion fuel production apparatus according to the present invention is expected to be widely used in facilities such as factories, hotels, hospitals, etc., where boiler facilities are introduced, the industrial applicability is extremely large. .

FIG. 1 is a conceptual diagram showing how the emulsion fuel production apparatus according to the first embodiment of the present invention is used. FIG. 2 is a system configuration diagram of the combustion apparatus according to the first embodiment of the present invention. FIG. 3 is a structural sectional view showing an example of the static mixer 22 in FIG. FIG. 4A is a structural sectional view schematically showing another example of the line mixer. FIG. 4B is a structural cross-sectional view showing a configuration example in which an ejector and a static mixer are connected to form an integrated structure. FIG. 5 is a sequence diagram for explaining an operation procedure during start-up and operation by the quantitative control method. FIGS. 6 (a) to 6 (d) are transition diagrams schematically showing how the water-in-oil emulsion burns over time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Oil tank 20 (20a-20d) Burner 30 Emulsion fuel manufacturing apparatus 40 Water tank 11 Oil pump (P1)
41 Water pump (P2)
50, 60 Ejector 70 Heater 80 Static mixer 90 Cushion tank 100 Return line 111 Emulsion fuel pressurizing pump (P3)
120 Emulsion fuel supply line

Claims (5)

An oil supply line that supplies fuel oil under pressure by an oil pump; a water supply line that supplies water under pressure by a water pump; a first ejector that joins the oil supply line and the water supply line; An emulsion fuel production section including a second ejector connected to an ejector outlet of the ejector, and a first mixer connected to a subsequent stage of the ejector outlet of the second ejector;
Returned from the cushion tank to the cushion tank itself via a cushion tank that is connected to the subsequent stage of the first mixer and temporarily stores the emulsion fuel, and an emulsion fuel pressurization pump provided at the subsequent stage of the cushion tank. A bypass line connected to the bypass line, a return line connected to the second ejector and an emulsion fuel supply line connected from the cushion tank to a fuel supply part of a combustion device. An emulsion fuel production apparatus characterized by the above. 2. The emulsion fuel production apparatus according to claim 1, further comprising a first heater on an annular piping path connecting the cushion tank from the return line and the first and second ejectors. The emulsion fuel production apparatus according to claim 1 or 2, wherein the cushion tank includes a second heater for keeping the emulsion fuel stored therein. 4. The emulsion fuel production apparatus according to claim 1, further comprising a second line mixer at a stage subsequent to the emulsion fuel pressurizing pump. 5. An operation method of the emulsion fuel production apparatus according to claim 1,
When the level of the emulsion fuel level in the cushion tank is less than or equal to the first set value, the cushion tank returns to the cushion tank itself via the bypass line until the second set value is reached. While producing emulsion fuel in the emulsion fuel production department,
When the position of the liquid level is equal to or higher than a second set value, the production of the emulsion fuel in the emulsion fuel production unit is stopped and the emulsion fuel in the cushion tank is sent to the second tank via the return line. A method of operating an emulsion fuel production apparatus, characterized in that it is returned to an ejector of the above.

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