JP2006046765A - Combustion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion device easy to maintain with a simple structure, which hardly generates a harmful gas such as carbon monoxide or nitrogen oxide or smoke and soot. <P>SOLUTION: This combustion device 1 comprises an oil injection nozzle 3 for injecting fuel oil 4 of ordinary temperature into a combustion furnace 2 having a cylindrical shape; a steam injection nozzle 6 for injecting superheated steam 5 into a mixing chamber 17a that is an area to which the fuel oil 4 is injected from the nozzle 3; a heated passage 7 that is a steam generation means generating the superheated steam 5; and a blower 8 that is a blowing means supplying air into the combustion furnace 2. The fuel oil 4 in an oil tank is supplied to the nozzle 3 via an oil feed pipe 10 by operating an oil pump P1, and water in a water tank is supplied to the heated passage 7 via a water feed pipe 14 by operating a water pump. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a combustion apparatus used as various heating means or heating means such as a boiler heating apparatus and a vinyl house heating apparatus.

  Conventionally, as a combustion apparatus using fuel oil such as kerosene or heavy oil and water, there is an emulsion type combustion apparatus. The emulsion-type combustion apparatus burns an emulsified liquid by adding an emulsion generation auxiliary agent such as water and a surfactant to fuel oil. However, in the case of an emulsion-type combustion apparatus, it is necessary to add water and a surfactant to the fuel oil and stir it or apply ultrasonic vibration to emulsify it, so that the emulsification process is complicated. Moreover, since it is difficult to maintain an emulsified state, the combustion state may become unstable.

  Therefore, a mixed combustion apparatus has been developed in which fuel oil and water are injected into a combustion furnace at a predetermined ratio, and both are mixed with each other and burned. As such a mixed combustion device, for example, there is a mixed combustion device of fuel oil and water according to the invention of the present applicant (see Patent Document 1).

  In the mixed combustion apparatus of fuel oil and water described in Patent Document 1, the fuel oil heated by the oil vaporization pipe and the water heated by the water vaporization pipe are respectively transferred from the oil injection nozzle and the water injection nozzle to the mixing chamber. Since the fuel is injected and burned in a mixed state, a stable combustion state can be maintained without misfire.

Japanese Patent Laid-Open No. 11-257604

  In the case of the mixed combustion apparatus described in Patent Document 1, since the fuel oil is heated and injected from the oil injection nozzle, it is necessary to provide an oil vaporizing pipe or the like for heating the fuel oil, resulting in a complicated apparatus. Yes. Further, when used for a long period of time, a part of the heated fuel oil may tar and the injection nozzle may be clogged, so that regular maintenance is required.

  The problem to be solved by the present invention is to provide a combustion apparatus that hardly generates harmful gases such as carbon monoxide and nitrogen oxides and soot, and has a simple structure and easy maintenance.

  The combustion apparatus of the present invention includes an oil injection nozzle that injects fuel oil at room temperature into the combustion furnace, a water vapor injection nozzle that injects superheated steam toward a region where fuel oil is injected from the oil injection nozzle, It is characterized by comprising steam generating means for generating the superheated steam and air blowing means for supplying air into the combustion furnace. Here, “normal temperature fuel oil” refers to fuel oil having an oil temperature of about 20 ° C. to 90 ° C., and “superheated steam” refers to water vapor in a high temperature state of about 180 ° C. to 850 ° C. at normal pressure. That means.

  With such a configuration, the combustion reaction is performed in a state where the fuel oil injected from the oil injection nozzle and the high-temperature superheated steam injected from the steam injection nozzle are mixed, so that carbon monoxide, nitrogen oxidation Hazardous gases such as things and soot are hardly generated. In addition, since normal temperature fuel oil is injected from the oil injection nozzle, there is no need to provide an oil vaporization pipe or the like as a heating / vaporization means for the fuel oil, and a simple structure can be achieved. Furthermore, since part of the heated fuel oil is not tarned and the injection nozzle is not clogged, maintenance is easy.

  If superheated water vapor is injected from the water vapor injection nozzle to normal temperature fuel oil injected from the oil injection nozzle, harmful gases such as carbon monoxide and nitrogen oxides and soot are hardly generated, and energy efficiency is improved. The reason for this is not fully understood, but it is speculated that it may be due to various factors described below.

  In the combustion apparatus of the present invention, when fuel oil is injected from the oil injection nozzle and superheated water vapor is injected from the water vapor injection nozzle, the particle diameter of the fuel oil liquid particle having a particle diameter of about 30 μm to 100 μm is several μm to Many water droplets of about 10 μm are included. When heated in the initial stage of combustion, the water droplets expand rapidly, and the expansion force causes the oil particles to explode and promotes microexplosion of the fuel oil, increasing the contact area between the fuel oil and air. As a result, the combustibility is improved even at a low air ratio, and as a result, the generation amount of CO and soot particles is reduced, and it is considered that the energy efficiency is improved.

On the other hand, the principle of CO production of hydrocarbon fuels is
_{C n H m + n / 2O} 2 → nCO + m / 2H 2 ····· (a)
And the reaction to suppress the formation of NO _x and unburned carbon material is
H ₂ O + C (fuel oil) → 2H + CO−28.1 kcal (b)
It is. Here, since the reaction (b) is an endothermic reaction, the temperature rises locally in the early stage of combustion to suppress the production of NO _x , and at the same time, the reaction with the unburned carbon substance occurs.

Here, the action of water can be shown by the following reaction formula.
H ₂ O + H → H ₂ + OH (endothermic) (c)
H ₂ O + O → OH + OH (endothermic)
H ₂ + O → H + OH (endothermic)

The reaction in the conversion process in which CO becomes CO ₂ can be represented by the following reaction formula.
CO + OH → CO ₂ + H (exotherm) (d)
CO + 2O → CO ₂ + O (exotherm) (e)
In this case, most of the conversion reaction is (d), and the reaction (e) is very slow and can be ignored. And it is thought that OH group produced | generated by reaction of (c) accelerates | stimulates reaction of (d), and suppresses the amount of CO.

In addition, because the heat generated in the reaction process in which CO is converted to CO ₂ is greater than the heat required in the decomposition process of H ₂ O, the flame temperature alone is limited to ordinary fuel alone. It is estimated that the temperature is higher than the flame temperature when burning.

  Although the research on the process of "micro explosion-> atomization promotion-> combustibility improvement (physical effect)" described above as the action of water on the combustion reaction has been almost established theoretically, In emulsion-type combustion devices that are only inferred based on verification, and the overall combustion equation has not yet been established, the atomization phenomenon due to micro-explosion is greatly affected. It is presumed that the effect is large.

The following items can be considered as the basis for such a guess.
(1) The flame temperature of the combustion apparatus of the present invention is 1500 ° C., which is about 300 ° C. higher than the flame temperature of the emulsion type combustion apparatus, and since the CO concentration in the exhaust gas is low, CO + OH → CO ₂ The reaction of + H (exotherm) is proceeding more actively.
(2) The water addition ratio with the best fuel saving effect is very large at 15% (volume ratio) in the case of the emulsion-type combustion apparatus, which is 40% (volume ratio) or more in the combustion apparatus of the present invention. On the basis of the extreme assumption that 15% of water in an emulsion-type combustion device brings only atomization promoting action, in the case of the combustion device of the present invention, about 62.5% of the water used is chemically It seems to have brought about an effect. The numerical value of 62.5% is based on {(40-15) / 40} × 100 = 62.5.
(3) Assuming that the atomization phenomenon occurs due to the inclusion of water droplets in the oil droplets, the present invention injects water vapor and oil gas separately, so both particles are bonded to each other. The probability is low.

  As described above, when superheated water vapor is injected from the water vapor injection nozzle to the normal temperature fuel oil injected from the oil injection nozzle, harmful gases such as carbon monoxide and nitrogen oxides and soot and smoke are almost generated. It is presumed that this is the reason why the energy efficiency disappears, and that the energy efficiency is improved.

  Here, it is desirable to provide as the steam generating means constituting the combustion apparatus a heated path through which water supplied from the outside is heated and vaporized by the heat generated in the combustion furnace and fed to the steam injection nozzle. With such a configuration, it is possible to generate superheated steam using the heat generated in the combustion furnace, so that it is not necessary to separately provide heating means, and the structure can be simplified.

  In this case, it is desirable to arrange the heated path in the combustion furnace. With such a configuration, it is possible to quickly raise the temperature and vaporize the water supplied from the outside by the heated path arranged in the combustion furnace in a high temperature state, so that the combustion efficiency is greatly increased. improves.

  The present invention has the following effects.

(1) An oil injection nozzle that injects normal temperature fuel oil into the combustion furnace, a water vapor injection nozzle that injects superheated steam toward a region where fuel oil is injected from the oil injection nozzle, and the superheated steam. By providing the water vapor generating means to be generated and the air blowing means for supplying air toward the combustion furnace, harmful gases such as carbon monoxide and nitrogen oxides and smoke are hardly generated, and the structure is simple. Maintenance is also easy.

(2) If a heated path is provided as the water vapor generating means for heating and vaporizing the water supplied from the outside by the heat generation of the combustion furnace and feeding it to the water vapor injection nozzle, the heat generation of the combustion furnace is used. Thus, since it is possible to generate superheated steam, it is not necessary to separately provide a heating means, and the structure can be simplified.

(3) If the heated path is arranged in the combustion furnace, it is possible to quickly raise the temperature and vaporize water supplied from the outside, so that the combustion efficiency is greatly improved.

  Hereinafter, a heating apparatus according to an embodiment of the present invention will be described with reference to the drawings. 1 is a partially cutaway side view showing a combustion apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic view showing the configuration of the combustion apparatus shown in FIG.

  As shown in FIGS. 1 and 2, the combustion apparatus 1 of the present embodiment includes an oil injection nozzle 3 for injecting fuel oil 4 at room temperature into a cylindrical combustion furnace 2, and an oil injection nozzle 3. A steam injection nozzle 6 for injecting superheated steam 5 into the mixing chamber 17a, which is a region where fuel oil 4 is injected from, a heated path 7 as steam generating means for generating superheated steam 5, and combustion And a blower 8 which is a blowing means for supplying air into the furnace 2.

  A normal temperature fuel oil 4 is accommodated in an oil tank 9 disposed at a position away from the combustion furnace 2, and the fuel oil 4 in the oil tank 9 is connected to the fuel supply pipe 10 by operating the oil pump P <b> 1. Via the oil injection nozzle 3. A flow rate regulator 11 for adjusting the supply amount of the fuel oil 4 to the oil injection nozzle 3 is arranged in the middle of the oil supply pipe 10 located on the downstream side of the oil pump P1. The fuel oil 4 supplied via the oil supply pipe 10 is injected into the mixing chamber 17a from the oil injection nozzle 3, and mixed with the superheated steam 5 injected from the water vapor injection nozzle 6 in this mixing chamber 17a and burned. To do.

  Further, a water tank 13 containing water 15 is disposed at a position away from the combustion furnace 2, and the water 15 in the water tank 13 passes through the water supply pipe 14 by operating the water pump P <b> 2. And supplied to the heated path 7. In the middle of the water supply pipe 14 located on the downstream side of the water pump P2, a flow rate regulator 16 for adjusting the supply amount of the water 15 to the heated path 7 is arranged.

  The heated path 7 disposed in the combustion furnace 2 includes a cylindrical water vaporizing cylinder 18 having a cavity 18 a in a partition wall, and a coiled superheated tube 19 communicating with the water vaporizing cylinder 18. The proximal end portion of the water vaporizing cylinder 18 is arranged so as to surround the cylindrical mixing cylinder 17 coaxially. On the extension of the water vaporizing cylinder 18 in the axial direction, the coiled superheated tube 19 is coaxially arranged. It is arranged to make. The front end portion of the superheat pipe 19 communicates with a water vapor supply pipe 20 that is piped in the direction of the blower 8 through the outside of the water vaporization cylinder 18 and the superheat pipe 19.

  The water 15 supplied via the water supply pipe 14 flows into the cavity 18a of the water vaporization cylinder 18, is heated and vaporized by the heat generated by the combustion reaction in the mixing chamber 17a, and then becomes water vapor in the superheat pipe 19. Flow into. The steam that has flowed into the superheater pipe 19 is further heated by the heat generated by the combustion reaction, rises in temperature through the steam supply pipe 20, and once returns to the blower 8 side. The water vapor 5 is injected into the mixing chamber 17a, mixed with the fuel oil 4 injected from the oil injection nozzle 3 described above, and combusted.

  When the combustion apparatus 1 is operated, first, the blower 8 is operated, the oil pump P1 is operated while air is sent into the mixing chamber 17a, and the fuel oil 4 injected from the oil injection nozzle 3 is ignited. Thereafter, when the water pump P2 is operated to gradually supply the water 15 in the water tank 13 to the heated path 7, the temperature rises and vaporizes in the cavity 18a of the water vaporizing cylinder 18 due to heat generated by the combustion of the fuel oil 4. The steam that has flowed into the superheated tube 19 rises in temperature while passing through it, and eventually becomes the superheated steam 5 from the steam spray nozzle 6 and is injected into the mixing chamber 17a and burns in the mixing chamber 17a. Combustion reaction is promoted by mixing with the existing fuel oil 4.

  Thus, after about 1 to 2 minutes have elapsed after the fuel oil 4 injected from the oil injection nozzle 3 is ignited, the air supplied from the blower 8 and the fuel oil 4 injected from the oil injection nozzle 3 Since the steam (superheated steam 5), which has become high temperature due to combustion, is injected into the mixing chamber 17a, if the blower 8 is stopped and the supply of air is stopped at that time, oil injection is performed thereafter. Combustion can be continued by the fuel oil 4 injected from the nozzle 3 and the superheated steam 5 injected from the water vapor injection nozzle 6. That is, after the injection of the superheated steam 5 starts, even if the blower 8 is stopped, the combustion continues while blowing out the flame vigorously toward the front end opening 2a of the combustion furnace 2.

  In the case of the combustion apparatus 1, ignition is simple and normal combustion operation can be started within a short period of 1 to 2 minutes after ignition. In addition, since the combustion operation can be performed even after the blower 8 is stopped after the injection of the superheated water vapor 5 is started, the electric power required to operate the blower 8 can be reduced. Note that the combustion state at the start of operation of the combustion apparatus 1 and the combustion state during the combustion operation can be adjusted by adjusting the flow rate regulators 11 and 16 to change the ratio of the supply amounts of the fuel oil 4 and the water 15. .

  Thus, in the combustion apparatus 1, the combustion reaction is performed in a state where the fuel oil 4 injected from the oil injection nozzle 3 and the high-temperature superheated steam 5 injected from the water vapor injection nozzle 6 are mixed. Harmful gases such as carbon monoxide and nitrogen oxides and soot are hardly generated. This could be confirmed by actually using a gas measuring device (Model 6215, model number CA-CALC, Nippon Kanomax Co., Ltd.) on the extension of the tip opening 2a of the combustion furnace 2.

  Moreover, since the normal temperature fuel oil 4 is injected from the oil injection nozzle 3, there is no need to provide means (such as an oil vaporization pipe) for heating or vaporizing the fuel oil 4 in advance, and the structure should be simple. Can do. Furthermore, since normal temperature fuel oil 4 is supplied, part of the fuel oil 4 is not tarned, and the injection nozzle 3 is not clogged with the tarred fuel oil 4, and maintenance is easy.

  Further, as the water vapor generating means, a heated path 7 is provided in which water 15 supplied from the outside is heated and vaporized by the combustion heat in the combustion furnace 2 and fed to the water vapor injection nozzle 6. For this reason, since the superheated steam 5 can be continuously generated using the heat generated in the combustion furnace 2, it is not necessary to separately provide a heating means, and the structure can be simplified.

  In this case, since the heated path 7 is disposed in the combustion furnace 2, the temperature of the water 15 supplied from the outside is rapidly increased by the heated path 7 disposed in the combustion furnace 2 in a high temperature state. The superheated steam 5 can be continuously generated by vaporizing, and the combustion efficiency is also good. In addition, it is equivalent to the combustion apparatus 1 by attaching the member from the water tank 13 via the to-be-heated path | route 7 to the water vapor | steam injection nozzle 6 which is a structural part of the combustion apparatus 1 to the existing oil type burner. It is also possible to constitute a combustion device.

  Conventionally, preheating at the start of operation takes time and has been an impediment to practical use. In the case of the combustion apparatus 1, the operation can be started in a short time of about 1 to 2 minutes after ignition. Therefore, such an obstruction factor is eliminated and practical use can be achieved.

  The combustion apparatus of the present invention can be widely used as various heating means or heating means such as a boiler heating apparatus and a greenhouse heating apparatus.

It is a partially notched side view which shows the combustion apparatus which is embodiment of this invention. It is the schematic which shows the structure of the combustion apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustion apparatus 2 Combustion furnace 2a Tip opening 3 Oil injection nozzle 4 Fuel oil 5 Superheated steam 6 Steam injection nozzle 7 Superheated path 8 Blower 9 Oil tank 10 Oil supply pipe 11, 16 Flow rate regulator 13 Water tank 14 Water supply pipe 15 Water 17 Mixing cylinder 17a Mixing chamber 18 Water vaporization cylinder 18a Cavity 19 Superheat pipe 20 Steam supply pipe P1 Oil pump P2 Water pump

Claims (3)

  An oil injection nozzle that injects fuel oil at normal temperature into the combustion furnace, a steam injection nozzle that injects superheated steam toward the region where fuel oil is injected from the oil injection nozzle, and water vapor that generates the superheated steam A combustion apparatus comprising: generating means; and air blowing means for supplying air into the combustion furnace.   The combustion apparatus according to claim 1, wherein the steam generation means is provided with a heated path for heating and vaporizing water supplied from the outside by heat generation of the combustion furnace and feeding the water to the steam injection nozzle.   The combustion apparatus according to claim 1, wherein the heated path is disposed in the combustion furnace.

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