JP2002115812A - Combustion method and apparatus for water-fossile fuel mixed emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion method and an apparatus for water-fossile fuel mixed emulsion wherein water-fossil fuel mixed emulsion is combusted with a high water content with high energy efficiency and high combustion calorie is obtained without interruption. SOLUTION: A combustion method and a combustion apparatus for water- fossile fuel mixed emulsion are adapted as follows. Water-fossile fuel mixed emulsion is pressurized and heated with heating means 3, 9 into a super critical fluid, and then the resultant water-fossile fuel mixed fluid is injected from a mixed fluid burner 6, which fluid is brought into contact with a Brown's gas flame of a browns gas burner 5 for combustion of the water-fossile fuel mixed fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and apparatus for burning a mixed emulsion of a fossil liquid fuel such as water and petroleum. More specifically, the present invention relates to a method and apparatus for burning a water-fossil fuel mixed emulsion that can burn the water-fossil fuel mixed emulsion with high energy efficiency and that emits less polluting gas into the environment.

[0002]

2. Description of the Related Art Various proposals have been made to mix fossil liquid fuel with water and burn it as a fuel emulsion from the viewpoint of resource saving and cleaner exhaust gas. Examples of such a fuel emulsion include an emulsion fuel using a special emulsifier that can be added to a petroleum-based fuel to form a highly hydrophilic gel. As a method for burning the fuel emulsion, a method has been proposed in which an emulsion fuel using cationized water is injected into a hot cathode chamber heated to a high temperature at which water decomposes and burned. Since fuel emulsions contain water, they cannot be ignited by a burner or the like in air at normal temperature and burned completely like ordinary fossil fuels. In many cases, it does not ignite. Conventionally, in order to completely burn such a fuel emulsion containing water and use it as a fuel, the temperature of the combustion environment had to be as high as about 1600 ° C. For this reason, although the fuel emulsion itself is expected to be used for various purposes,
Sustained combustion has only been achieved in very specific circumstances. Also, for example, the combustion space used in boilers, gas turbines, etc. that are generally put into practical use
Maintaining a high temperature environment, such as a (chamber) or a combustor,
This is difficult because the steam and gas flow remove heat, which has been a major problem in its widespread use and practical application in terms of energy efficiency and economy. Furthermore, in recent years, reduction of CO ₂ (carbon dioxide) emission has been required on a global scale, and there is a long-felt need for a fuel combustion system that can be obtained with a certain amount of combustion calories and as little CO ₂ emission as possible. The water-fossil fuel-mixed emulsion can reduce CO ₂ emissions during combustion by mixing water with the water-fossil-fuel-mixed emulsion more efficiently than the fossil fuel alone. The development of the device was desired. The present applicant has already filed an application for the combustion of a water-fossil fuel emulsion (see Japanese Patent Application Laid-Open No. 11-166705), but it has not been satisfactory in terms of energy efficiency. In addition, water in a supercritical state (critical temperature 374.2 ° C., critical pressure 22.12 MPa), which has recently attracted attention, has a density of 1/6 to 1 of that of liquid.
It is widely known that the viscosity is about the same as that of a gas, and the diffusion coefficient is between a liquid and a gas.

[0003]

Accordingly, the present invention provides
It is an object of the present invention to provide a method of burning a water-fossil fuel mixed emulsion in which a water-fossil fuel mixed emulsion having a high water content is burned with high energy efficiency and high calories are continuously obtained. Another object of the present invention is to provide a combustion apparatus capable of efficiently and economically burning a water-fossil fuel mixed emulsion having a high water content.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and as a result, it has been found that when burning a mixed emulsion, the fuel is more preferably in the form of mist than in the gaseous state. That is, the heated fuel mist comes into contact with the Brown's gas flame and explosively decomposes first to hydrogen-oxygen, and the water component on the side that receives the explosive energy of the oil component that serves as the detonator must also have a certain size. However, they learned that water gas molecules are too small. In addition, the supercritical fluid of the water-fossil fuel mixed emulsion has a very large molecule like a liquid, is actively activated like a gas molecule, has a large kinetic energy, and has a very high molecular density comparable to a liquid. It has been found that the active fluid has a high decomposition activity. In order to sustain the combustion of the water component as a hydrogen / oxygen flame, it was found that its kinetic energy and molecular frequency needed to match the Browns gas molecules at the ignition point. Obtaining knowledge that can be solved by making it supercritical fluid,
The present invention has been made based on these findings.

That is, according to the present invention, (1) a water-fossil fuel mixed emulsion is pressurized and heated to form a supercritical fluid, and then the supercritical fluidized water-fossil fuel mixed fluid is ejected from a mixed fluid burner to produce a Brownian's mixture. A method for burning a water-fossil fuel mixed emulsion which is brought into contact with and burned with a Browns gas flame by gas combustion, (2) the ratio of water in the water-fossil fuel mixed emulsion is 95 to 70% by volume ratio. (3) The method for burning a water-fossil fuel mixed emulsion according to (1), wherein (3) the emulsion is pressurized by a supply pressurizing pump and heating is performed by heat exchange with flue gas. Combustion method, (4) means for pressurizing and heating water-fossil fuel mixed emulsion to make it supercritical fluid, and mixing means for injecting water-fossil fuel mixed fluid produced by making it supercritical fluid A fluid burner, a browns gas burner, and a combustion chamber provided with the mixed fluid burner and the browns gas burner. In the combustion chamber, the browns gas flame of the browns gas burner is applied to the mixed fluid stream injected from the mixed fluid burner. (5) The apparatus for burning a water-fossil fuel mixed emulsion which can be brought into contact with the fuel, and (5) the pressurizing means is a supply pressurizing pump, and the heating means is a heat exchanger attached to a flue. A water-fossil fuel mixed emulsion combustion apparatus.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The water-fossil fuel mixed emulsion to be burned in the present invention is a liquid fuel containing water and a liquid fossil fuel. Examples of the liquid fossil fuel include kerosene, light oil, and heavy oil. Since water makes the mixed emulsion supercritical, tap water, distilled water and the like are not particularly limited, and there is no need to use activated water such as tourmaline water or reduced water as in the known invention. The mixing ratio of the water and the liquid fossil fuel in the water-fossil fuel mixed emulsion that can be used in the present invention is not particularly limited, but the water ratio in the emulsion (generally an oil-in-water emulsion) is usually 95 to 95 by volume. preferably 70%, particularly preferably 95 to 75% from the viewpoint of reduction of CO ₂ emissions during combustion. In addition, in addition to water and fossil fuel,
A trace amount of a surfactant or tourmaline can be added as needed, but it is not necessary to pay special attention to the performance as an emulsion.

In the present invention, the above-mentioned water-fossil fuel mixed emulsion is prepared at a temperature of 390 ° C. or higher and a pressure of 23.0 MPa.
The supercritical state is maintained, and a supercritical fluid is injected from the state through an injection nozzle and burned. The mixed emulsion is pressurized by a supply pressurizing pump, and if necessary, further pressurized by a pressurizing pump to a pressure higher than the critical pressure. It is necessary to heat the temperature of the water-fossil fuel mixed emulsion at room temperature to 390 ° C. or higher, and preferably to 400 to 450 ° C. There is no particular limitation on the heating and heating method, and from the viewpoint of heating cost, it is preferable to heat exchange with flue gas in the combustion chamber to increase the temperature.However, an electric heater or a steam heat exchanger is provided in the feed path after pressurization. It may be provided and heated.

[0008] A Browns gas flame is brought into contact with the water-fossil fuel mixed fluid stream which is supercritical fluidized and injected as described above. The Browns gas itself used in the present invention is a non-explosive mixed gas obtained by electrolysis of water, in which hydrogen and oxygen are mixed at a volume ratio of 2: 1. It is known that the generation of heat results in extremely high combustion temperatures. According to the present invention, the browns gas is burned by using a torch nozzle and an igniter that emits an ignition spark, for example, to about 2300
A high reducing flame at <RTIgt; 0 C </ RTI> is created, and the tip of the flame, preferably of good reactivity, is brought into contact with the mixed fluid stream. This allows
The mixed fluid burns at a high temperature. This is because the Browns gas flame heats the mixed fluid stream and interacts with active chemical species generated from fossil fuels in the mixed fluid to burn fossil fuel, generate high heat and turn it into a supercritical fluid The water molecules in the mixed fluid are several hundred times larger than the gaseous water molecules, so the high heat is sufficiently received by the water molecules, and further exploded with steam to burn fast as a hydrogen / oxygen gas flame (Brown's gas flame) and propagate the flame And the entire mixture fluid is burned. The speed of the high-speed combustion by the steam explosion is, for example, about 7.25 times (linear velocity: 2.9 m / s) the combustion of propane. In addition, even if a propane gas flame, a city gas flame, an acetylene flame, etc. are brought into contact with a supercritical fluidized water-fossil fuel mixed emulsion fluid stream, they do not burn well, but these flames are mainly composed of hydrogen atoms. It is considered that unlike the Browns gas flame described above, the supply of oxygen from the outside is essential, and the interaction with the emulsion fluid flow is different. In the above combustion mechanism, active chemical species react with oxygen generated by steam explosion, so the amount of oxygen that must be supplied from the outside during combustion is much smaller than normal combustion, and combustion that does not substantially use air A system is also possible. For example, if the volume ratio of water: fossil fuel is 9: 1,
It is considered that the amount of oxygen required from the outside for combustion is one tenth or less of the conventional amount. The combustion method and the combustion apparatus of the present invention can continuously obtain high combustion calories by using a water-fossil fuel mixed emulsion in which the amount of use of fossil fuel is reduced, so that it is economical and fossil fuel in air. Emissions that cause pollution can be significantly reduced as compared with the case where fuel is burned.

Next, the combustion method and the combustion apparatus of the present invention will be described in more detail with reference to the drawings. FIG. 1 is an explanatory view showing the configuration of an embodiment of the apparatus of the present invention.
This is an example in which a fossil fuel mixed emulsion is heated by heat exchange with flue gas. In the figure, 1 is a water-fossil fuel mixed emulsion storage tank, 2 is a kerosene tank, 3 is a water-fossil fuel mixed emulsion supply pressurizing pump, 4 is a browns gas generator, 5 is a browns gas burner, and 6 is a mixed fluid burner. , 7 is a combustion chamber, 8 is a flue, 9 is a heat exchanger, 1
0 heat resistant material, 11 is a _heater, V 1 ~V ₅ are each valve. At the start of this device,
The switching valve _{V 1} was kerosene tank 2 side, the switching valve _{V 2} is switched to the burner side, discharged pressure 0.5~0.6MPa valve _{V 3} is closed supply pressure pump 3
The kerosene is injected from the mixed fluid burner 6 of the combustion chamber 7 and ignited to heat the combustion chamber. Combustion chamber heated, the valves V ₁ switched flue gas temperature of the flue 9 reaches 850 ° C. C. to 1100 ° C. to emulsion storage tank 1 side, switching the switching valve V ₂ to the heating Atsushi Nobori side, the valve V ₃ is opened, and a normal temperature water-fossil fuel mixed emulsion in the storage tank 1 is supplied. The discharge pressure of the pressure pump 3 is 23.0 to 26.0MP.
At a, the mixture is sent to the mixed fluid burner 6 through the heat exchanger 9. FIG. 1 shows switching valves V ₁ and V ₂ and a common supply pressurizing pump. However, a supply line for water-fossil fuel mixed emulsion and a supply line for kerosene are separately provided. And a high-pressure supply pressurizing pump for water-fossil fuel mixed emulsion and a supply pressurizing pump for kerosene.
Here, the mixed emulsion is heated by the heat exchanger and reaches 390 ° C. or higher at the outlet thereof, and becomes a supercritical fluid, passes through the heat insulating pipe 10 and the valve V ₃ , and becomes an active mist from the mixed fluid burner 6. Is gushing. On the other hand, the Browns gas burner 5 near the fluid burner 6
The Brown's gas generated by the Brown's gas generator 4 is injected through a valve V ₄ and ignited by an igniter (not shown) to form a Brown's gas flame which comes into contact with the mixed fluid flow from the mixed fluid burner 6 and mixes. Burn the fluid stream. Although the atmosphere of the combustion chamber 7 is a normal ambient atmosphere via a valve V ₅ from the outside can be introduced air, the more one oxygen or ozone, adjusting the composition of the gas in the combustion chamber 7 (e.g. Oxygen excess, etc.). In the present invention, it is not necessary to raise the temperature of the entire combustion chamber 7 when the water-fossil fuel mixed emulsion is burned, and the water-fossil fuel mixed emulsion can be continuously and completely burned by the contact of the Brown's gas flame.

FIG. 2 is an enlarged explanatory view showing the state of the flame from the Browns gas burner 5 and the flow of the mixed fluid from the mixed fluid burner 6. When the P point of the mixed fluid stream injected from the mixed fluid burner 6 is brought into contact with a point, preferably at the tip, of the bun rounds gas flame 21 (about 2300 ° C.) from the Browns gas burner 5, the fossil fuel component in the mixed fluid stream becomes Browns. Combustion at high temperature exceeding 4000 ° C by reaction with gas flame. At this high temperature, active water molecules in the mixed fluid stream are decomposed into a gas mainly composed of Browns gas. This gas instantaneously self-combustes at the point P, and the combustion becomes flame propagation, and chain combustion occurs in the directions A and B from the point P, so that the entire mixed fluid injected from the mixed fluid burner 6 burns. In the drawing, reference numeral 22 denotes a flame of the combustion of the mixed fluid. At this time, it is preferable to install the mixed fluid burner 6 and the Browns gas burner 5 such that the contact angle between the mixed fluid flow and the Brown's gas flame is 15 to 30 °. Further, the position of the point P where the Browns gas flame contacts is usually within a range where the temperature of the mixed fluid flow is properly maintained without lowering, and is about 4 to 8 cm from the nozzle tip of the mixed fluid burner 6. Position is preferred.

The combustion method and the combustion apparatus of the present invention can be used, for example, as a heating furnace having the above-described combustion chamber, and as a boiler, a hot air generator, a gas turbine generator, and the like.
It can also be used for incineration of waste, firing of ceramic products, carbonization of materials, and the like.

[0012]

Next, the present invention will be described in more detail with reference to examples. With the combustion system having the configuration shown in FIG. 1, the fuel supply amount is 65 liter / h, and the combustion heat amount is 1,000,000 k.
The outline of the energy comparison when operated at cal / h is shown. As the water-fossil fuel mixed emulsion, tap water and heavy oil were used in a volume ratio of 80:20, and a surfactant of 0.4% by mass of heavy oil was added. First, from the kerosene tank 2 to 0.
Kerosene is supplied by the pump 3 at a discharge pressure of 5 MPa,
The mixed fluid burner 6 ignites and burns, heats the furnace, and when the flue gas temperature reaches about 1000 ° C., switches the switching valves V ₁ and V ₂ , opens V ₃ , and supplies the water-heavy oil mixed emulsion. The pressure was supplied by the pressure pump 3 and an additional pressure pump at a discharge pressure of 24.5 MPa. The supplied mixed emulsion passed through a heat exchanger provided in the flue section and was heated to about 420 ° C. by the flue gas. The mixed fluid that has reached the supercritical state by pressurization and heating
0, ejecting valve _{V 3} from the street mixed fluid burner 6.
An igniter for browns gas from burner 5 (not shown)
And the tip of the 2300 ° C. browns gas flame is mixed with the mixed fluid flow from the mixed fluid burner 6 (5 c from the burner tip).
When applied to m), the mixed fluid burned to emit a flame and continued burning.

According to the method of converting the water-fossil fuel mixed emulsion into a supercritical fluid, a fuel supply rate of 65 liter /
h (52 liters / h of water, 13 liters / h of heavy oil) and the amount of energy applied to the fuel when operated at a combustion heat of 1,000,000 kcal / h are roughly as follows. (B) Power consumption of the pump 3 3 kwH = 2,580 kcal / h (b) Heated to 400 degrees 65 × (400-15) = 25,025 kcal / h (b) + (b) = 28,605 kcal / h (A) For comparison, the method of evaporating and supplying a water-fuel oil mixed emulsion described in the specification of the prior application and supplying the same in the same manner as described above also provides a fuel supply amount of 65 L / h (58.5 L / water).
h, kerosene 6.5 liters / h), heat of combustion 1,000,000 kc
The energy amount when operating at al / h was calculated. (B) 'Power consumption of the pump 0.3 kwH = 258 kcal / h (b)' Heated to saturated steam 65 x (100-15) + 58.5 x 539 = 37,057 kcal / h (a) '+ (b)' = 37,315 kcal / h (B) Comparing (A) and (B), (A) / (B) ≒ 0.77, and the supercritical method of the present invention is a method for evaporating and vaporizing. In comparison, the amount of energy to be applied is as small as about 77%. Similarly, when the energy input from the outside under the operating condition of 1,000,000 kcal / h is calculated, (c) Brownian gas generation is 7kwH = 6,020kcal / h (b) + (b) + (c) = 34 , 625 kcal / h Therefore, the ratio of the required energy is about 3.5%. [(34,625 / 1,000,000) × 100 ≒ 3.46]

Comparative Example A browns gas generator was stopped using the same combustion apparatus as in the embodiment, and an attempt was made to ignite with a propane gas flame into a mixed fluid stream in which the same water-heavy oil mixed emulsion used in the embodiment was brought into a supercritical state. As a result, the mixed fluid did not burn well.
Note that a mixed fluid stream having a water content of up to about 15% could be burned with a propane gas flame.

[0015]

According to the present invention, water having a high water content
Efficiently burns fossil fuel mixed emulsions and reduces C
High combustion calories can be obtained with the amount of generated O ₂ . Further, in the present invention, since the water-fossil fuel mixed emulsion is a fluid in a supercritical state, this mixed fluid becomes an active fluid, has a kinetic energy and a molecular frequency equivalent to Brown's gas, and is brought into contact with the Brown's gas flame. As a result, the entire mixed gas can be continuously burned at a high temperature economically and energy-efficiently without setting the entire combustion environment to a very high temperature unlike the related art. Furthermore, the pump power is an electric input, but the heating energy for supercriticality can utilize the waste heat of the flue gas and is extremely energy efficient.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of a combustion device of the present invention.

FIG. 2 is an explanatory diagram of a mixed fluid flow and a Brown's gas flame in the combustion device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Storage tank of water-fossil fuel mixed emulsion 2 Kerosene tank 3 Water-fossil fuel mixed emulsion supply pressurizing pump 4 Brown's gas generator 5 Brown's gas burner 6 Mixed fluid burner 7 Combustion chamber 8 Flue 9 Heat exchanger 10 Heat resistant coating material 11 heater V ₁ ~V ₅ valve 21 Brown's gas flame 22 mixed fluid flame

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 3K052 AA10 AB01 AB08 GA10 GB01 GB08 GC07 GD03 3K065 RA00 RB02 3K068 AA11 AB03 BA03 CA11 EA01 EA02 EA03 FB06 JA06

Claims (5)

[Claims] 1. A water-fossil fuel mixed emulsion is pressurized and heated to form a supercritical fluid, and then the supercritical fluidized water-fossil fuel mixed fluid is ejected from a mixed fluid burner to produce a Brown's gas flame by Brown's gas combustion. And burning the mixture. 2. The method for burning a water-fossil fuel mixed emulsion according to claim 1, wherein the proportion of water in the water-fossil fuel mixed emulsion is 95 to 70% by volume. 3. The method of burning a water-fossil fuel mixed emulsion according to claim 1, wherein the emulsion is pressurized by a supply pressurizing pump, and the heating is performed by heat exchange with flue gas. 4. A means for pressurizing and heating a water-fossil fuel mixed emulsion into a supercritical fluid, a mixed fluid burner for injecting a water-fossil fuel mixed fluid generated by supercritical fluidization, a Browns gas burner, A combustion chamber provided with the mixed fluid burner and the browns gas burner, wherein the browns gas flame of the browns gas burner can come into contact with the mixed fluid flow injected from the mixed fluid burner in the combustion chamber. A water-fossil fuel mixed emulsion combustion device. 5. The pressurizing means is a supply pressurizing pump,
5. The apparatus according to claim 4, wherein the heating means is a heat exchanger attached to a flue.