JP2001248808A - Combustion equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable combustion equipment on the thick and thin fuel combustion method to obtain normal combustion by suppressing the recondensation of gasified liquid fuel. SOLUTION: In this combustion equipment, a thick-side opening 45 which enables a thick premixed gas generating chamber 39 to communicate with a thick burner port 23, a thin-side opening 46 which enables the chamber 39 to communicate with a thin premixed gas generating chamber 44, and the chamber 44 are provided in a heat transfer means 42 which returns the heat of flames to a gasifying means 37 and the recondensation of gasified fuel is prevented by suppressing the temperature drop of the fuel until the fuel reaches the burner ports 23 and 25. Therefore, the fuel can be burnt at a desired excess air ratio and the occurrence of NOx, CO, HC, soot, etc., can be suppressed. At the time of shutting-off this equipment, in addition, the occurrence of an offensive smell can be suppressed, because no condensed fuel is left.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low NOx combustion system, and more particularly to a lean combustion system.

[0002]

2. Description of the Related Art Conventionally, a combustion apparatus based on a gray-scale combustion system has generally been described in JP-A-7-19419. As shown in FIG.
Is a combustion tube, in the center of which is a mixing chamber 2, and on both sides of it a dense flame port 3
And a light-side flame port 5 is provided at the upper part of the mixing chamber 2 by a light-side flame port structure 4. Reference numeral 6 denotes an air port provided in a lower portion of the mixing chamber 2, and 7 denotes a light-side gas ejection hole provided on an inner wall of the deep-side flame opening 3. The dense-side flame port 3 has a dense-gas chamber 10 provided with a dense-side flame port 8 in the upper part and a through hole 9 in the lower part.
1 is formed.

In the above configuration, the rich gas is blown into the mixing chamber 2 from the light gas outlet 7 and mixed with the air from the air port 6 to generate a light gas. To form a light flame in the center. One-way hole 9 through dense gas chamber 10
The concentrated gas that has flowed into the blast blows out and burns from the upper dense side flame port 8 to form a rich flame on both sides. The unstable light flame is held by the rich flame on both sides.

Here, the amount of concentrated gas flowing into the dense gas chamber 10 from the through hole 9 is determined by the opening area determined by the number of holes or the hole diameter of the through hole 9, and is discharged from the light-side gas outlet 7. The gas amount and the gas distribution amount are determined.

[0005]

However, in the conventional combustion apparatus, when a liquid fuel such as kerosene is heated and vaporized and burned, the temperature upstream of the light-side flame port 5 and the deep-side flame port 8 is low. The temperature of the vaporized fuel drops and condenses and adheres to various parts. For this reason, the recondensed fuel mixes with the vaporized fuel to produce soot,
There is a problem that normal combustion cannot be obtained, such as generation of a large amount of Ox, CO, and HC. This phenomenon is particularly remarkable at the time of ignition when the burner temperature is low. Further, even during fire extinguishing, the condensed fuel remains and gradually evaporates, so that there is a problem that a strong odor is generated.

[0006] Here, the dark side flame port structure 1 having a through hole 9 formed therein
The stagnation of the flow of the vaporized fuel occurs on the upstream side of the dense-side flame port 3 in which the first gas injection hole 7 and the light-side gas ejection hole 7 are formed, and recondensation in this portion is remarkable. Further, the temperature of the fresh gas mixed with air at room temperature decreases, and the temperature of the fresh gas flowing near the wall of the mixing chamber 2 further decreases, and recondensation in that portion is also remarkable.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a lean premixed gas generation chamber, a rich premixed gas generation chamber, and a rich side opening and a rich premixed gas generation chamber communicating with the rich flame port. A light-side opening for communicating the gas with the light premixed gas generation chamber is provided in the heat transfer means for returning the heat of the flame to the vaporizing means.

According to the invention, the temperature of the vaporized fuel is prevented from lowering down to the rich flame port and the light flame port, and recondensation of the vaporized fuel is prevented. Therefore, combustion can be performed at a desired excess air ratio, and generation of NOx, CO, HC, soot, and the like can be suppressed. Further, even when the fire is extinguished, the condensed fuel does not remain, so that generation of odor can be suppressed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A combustion apparatus according to a first aspect of the present invention includes a rich flame port and a light flame port, heat receiving means for receiving heat from a flame, and heat received by the heat receiving means being recirculated to heat and vaporize liquid fuel. Vaporizing means, heat transfer means for returning heat received by the heat receiving means to the vaporizing means, and a rich fuel mixture for mixing the liquid fuel vaporized by the vaporizing means and the premix air to produce a rich premixed gas. An air-fuel mixture generation chamber, a light-air-fuel mixture generation chamber provided in the heat transfer means for mixing the air-rich mixture and the dilution air to generate a light air-fuel mixture, and a rich air-fuel mixture generation chamber provided in the heat transfer means. A rich-side opening for communicating the mixture gas generation chamber with the rich flame port, and a light-side opening provided in the heat transfer means for communicating the rich premixture gas generation chamber and the light premixture gas generation chamber. I have.

Since the rich side opening, the light side opening and the light premixed gas generation chamber are provided in heat transfer means for returning the combustion heat to a high temperature, the vaporized fuel is supplied to the rich flame opening and the lean flame. No recondensation occurs due to the temperature drop to the mouth.
Therefore, combustion can be performed at a desired excess air ratio, and NOx, CO, H
C, soot, etc. can be suppressed from occurring. Further, even at the time of fire extinguishing, since the recondensed fuel does not remain, generation of odor can be suppressed.

In the combustion apparatus according to a second aspect of the present invention, the dilution air opening is provided in the heat transfer means.

Since the dilution air is preheated when flowing through the heat transfer means, a decrease in the temperature of the lean premixture is suppressed,
Recondensation of vaporized fuel in the lean premixed gas generation chamber can be more effectively suppressed.

According to a third aspect of the present invention, there is provided a combustion apparatus comprising a flame-holding cylinder in which a rich flame port and a light flame port are alternately arranged on a circumference, and a side surface of which faces the rich flame port and the light flame port. And the flame holding tube is used as a heat receiving means.

Then, the rich flame and the light flame collide with the heat receiving means, so that the heat can be effectively received and the lift of the rich flame and the light flame can be suppressed.

In the combustion apparatus according to a fourth aspect of the present invention, the rich flame port and the light flame port are alternately arranged on the circumference, and the protruding portion whose side faces the rich flame port and the light flame port is transmitted. The projection is integrally formed with the heating means, and the projection is used as the heat receiving means.

[0016] Since the projection integrally formed with the heat transfer means receives the heat, the heat transfer means can be maintained at a high temperature, and the recondensation of the vaporized fuel can be more effectively suppressed.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a combustion apparatus according to Embodiment 1 of the present invention, FIG. 2 (a) is a plan view showing the flame port plate, and FIG. 2 (b) is a partition plate thereof. It is a top view. FIG.
FIG. 4 is a sectional view taken along line AA in FIG. 1, and FIG.
FIG. 4 is a cross-sectional view taken along line B.

In FIG. 2, reference numeral 21 denotes a disc-shaped flame opening plate. As shown in FIG. 2A, a first notch 22 is a dense flame outlet 23 from which a rich premixed gas is jetted, and a second notch is provided. Reference numeral 24 denotes a light flame port 25 through which a light premixed gas is jetted, and a first light premixed gas flow opening 26 is provided at the center. The rich flame ports 23 and the light flame ports 25 are provided alternately on the circumference. First notch 22
The width of the notch is smaller than that of the second notch 24, and the depth of the notch is shallower. 27 is a disk-shaped partition plate,
As shown in FIG. 2B, a plurality of first rich premixed gas flow openings 28 are provided concentrically, and a second light premixed gas flow opening 29 is provided at the center. The partition plate 27 separates the two flame opening plates 21, and the diameter of the second pale premixed gas passage opening 29 is larger than the diameter at which the end of the second notch 24 is located,
The diameter of the first notch 22 is smaller than the diameter at which the end of the first notch 22 is located.

Reference numeral 30 denotes a bottom plate, in which a plurality of second dense premixed gas flow openings 31 are provided concentrically, and a third light premixed gas flow opening 32 is provided in the center. The partition plate 27 and the flame port plate 21 are sequentially stacked on the bottom plate 30 in the vertical direction, and the top plate 33 is finally provided. Flame plate 21 and partition plate 27
Are set as one set, and the number of these sets is selected according to the fuel input.

Here, near the end of the first notch 22, the first rich premixed gas passage 28 shown in FIG. 2 and the second rich premixed gas passage 31 shown in FIG. Ki 2
3 is formed. On the other hand, the first and second light premixed gas flow openings 26 and 29 shown in FIG. 2 and the third light premixed gas flow opening 32 shown in FIG. A supply passage to the light flame port 25 is formed. Numerals 34 and 35 denote a rich flame and a light flame alternately formed on the flame plate 21. Reference numeral 36 denotes a flame holding cylinder (heat receiving means) whose side faces face the rich flame port 23 and the light flame port 25.

Reference numeral 37 denotes vaporizing means for heating and vaporizing the liquid fuel, and includes a heater 38 therein. A rich premixed gas generation chamber 39 is formed inside the vaporizing means 37, and a rotating body 40 is provided. 41 is a nozzle for supplying liquid fuel.

Reference numeral 42 denotes a heat transfer means provided downstream of the vaporization means 37. The heat transfer means 42 is provided with a rich flame port 23 and a light flame port 25.
And a protrusion 43 (heat receiving means) whose side faces face each other. Further, a light premixed gas generation chamber 44 in which a light premixed gas is generated in the heat transfer means 42, a rich side opening 45 communicating the rich premixed gas generation chamber 39 with the rich flame port 23, and a rich premixed gas generation chamber 3
9 and a light-side opening 46 for communicating the light premixed gas generation chamber 44
In addition, a dilution air opening 48 for communicating the dilution air supply chamber 47 with the light premixed gas generation chamber 44 is provided. The dilution air openings 48 are provided radially at predetermined intervals as shown in FIG.

49 is an air supply means, 50 is a premixing air supply passage communicating with the rich premixed gas generation chamber 39, and 51 is a dilution air supply passage communicating with the dilution air supply chamber 47.

Next, the operation and operation will be described.
In step (1), the heater 38 is energized by an ignition command signal from a control unit (not shown) to preheat the vaporizing unit 37 to a predetermined temperature. After the completion of the preheating, the liquid fuel is supplied to the rotating body 40 by the nozzle 41 by a fuel pump (not shown). The rotating body 40 is driven by a motor (not shown), and shakes and atomizes the liquid fuel from the rotating body 40 by centrifugal force. The atomized liquid fuel collides with the inner surface of the vaporizing means 37 and is vaporized.

The air supplied by the air supply means 49 is divided into two parts, one of which is supplied through the premixing air supply passage 50 to the rich premixed gas generation chamber 39 as premixing air. The other is supplied to the dilution air supply chamber 47 through the dilution air supply passage 51. The rich premixed gas is generated by mixing the vaporized fuel and the premixing air in the rich premixed gas generation chamber 39.

The rich premixture is divided into two systems by the heat transfer means 42. Part of the rich premixed gas flows through the rich side opening 45 and is supplied to the rich flame outlet 23. The remainder of the rich premixed gas flows through the light side opening 46 and is supplied to the light premixed gas generation chamber 44,
It is diluted by the dilution air supplied through the dilution air opening 48 to produce a lean premix. The light premixed gas flows out of the light premixed gas generation chamber 44 and is supplied to the light flame port 25. Then, the flame is ignited by the operation of the ignition means (not shown), and a rich flame 34 and a light flame 35 are formed. After ignition, the ignition means stops operating.

Since the rich flames 34 and the light flames 35 are alternately formed on the circumference, the arrangement end of the rich flames 34 and the light flames 35 does not exist. Accordingly, the flow velocity variation between the rich flames 34 or the light flames 35 is small, and the uniform flames are divided into the rich flames 34 and the light flames 35, which are small and uniform. You. Further, the fuel distribution ratio and the excess air ratio to the lean premix can be increased, and NOx can be suppressed.

The rich flame 34 and the light flame 35 collide with the flame holding cylinder 36 and the projection 43, and the lift is effectively suppressed, and the flame holding cylinder 36 and the projection 43 receive heat efficiently.
The received heat is returned to the vaporizing means 37 by the heat transfer means 42.
After a while after the ignition, the power supply to the heater 38 is stopped, but the vaporizing means 37 is maintained at a predetermined temperature (250 ° C.) or higher, and the liquid fuel is vaporized.

Here, the light premixed gas generation chamber 44 and the dense side opening 4
5 and the light side opening 46 are provided in the heat transfer means 42 which is maintained at a high temperature by the heat received by the flame holding cylinder 36 and the projection 43, so that the rich premixed gas and the light premixed gas are supplied to the rich flame port 23 and the light No recondensation occurs due to a temperature drop in the path leading to the flame outlet 25. Further, since the dilution air is preheated by the heat transfer means 42 when flowing through the dilution air opening 48, even if the rich premixed air is mixed with the low-temperature dilution air to produce a light premixed air. The light premix is maintained at a temperature above the recondensation.
Therefore, combustion can be performed at a desired excess air ratio, and NOx, CO, H
C, soot and the like can be suppressed. Further, even when the fire is extinguished, the condensed fuel does not remain, so that generation of odor can be suppressed.

In the above embodiment, gaseous fuel such as city gas can be used. In that case, the configuration related to the vaporization of the liquid fuel described in the above embodiment can be omitted.

[0032]

As described above, according to the first aspect of the present invention, the rich side opening, the light side opening and the light premixed gas generation chamber are provided in the heat transfer means in which the combustion heat is recirculated and maintained at a high temperature. Therefore, recondensation due to a temperature drop does not occur before the vaporized fuel reaches the rich flame port and the light flame port. Therefore, combustion can be performed at a desired excess air ratio, and generation of NOx, CO, HC, soot, and the like can be suppressed. Further, even at the time of fire extinguishing, since the recondensed fuel does not remain, generation of odor can be suppressed.

According to the second aspect of the present invention, since the dilution air is preheated when flowing through the heat transfer means, a decrease in the temperature of the lean premixture is suppressed, and the vaporization in the lean premixture generation chamber is performed. Fuel recondensation can be more effectively suppressed.

Further, according to the third aspect of the present invention, the rich flame and the light flame collide with the heat receiving means, so that the heat can be effectively received and the lift of the rich flame and the light flame can be suppressed.

According to the fourth aspect of the present invention, since the projection integrated with the heat transfer means receives heat, the heat transfer means can be maintained at a high temperature, and the recondensation of the vaporized fuel can be more effectively suppressed. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view of a combustion device according to an embodiment of the present invention (a sectional view taken along line XYZ in FIGS. 3 and 4).

FIG. 2A is a plan view showing a flame port plate of the combustion device. FIG. 2B is a plan view showing a partition plate of the combustion device.

FIG. 3 is a sectional view of the combustion device taken along line AA in FIG. 1;

FIG. 4 is a sectional view of the combustion device taken along line BB in FIG. 1;

FIG. 5 is a perspective view showing a conventional combustion device.

[Explanation of symbols]

 23 Rich Flame Port 25 Light Flame Port 36 Flame Holding Cylinder (Heat Receiving Means) 37 Evaporating Means 39 Rich Premixed Gas Generation Chamber 42 Heat Transfer Means 43 Projection (Heat Receiving Means) 44 Light Premixed Gas Generation Chamber 45 Dark Side Opening 46 Light Side opening 48 Air opening for dilution

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F23D 11/44 F23D 11/44 B (72) Inventor Norio Shiya 1006 Odakadoma, Kadoma City, Osaka Matsushita Electric Industrial F term in the company (reference) 3K052 AA05 AC01 EB07 EB09 3K065 TA01 TA04 TD04 TH04 TP01

Claims (4)

[Claims] A heat receiving means for receiving heat from the flame; a heat receiving means for receiving heat from the flame; a vaporizing means for heating and vaporizing the liquid fuel by recirculating heat received by the heat receiving means; A heat transfer means for returning to the means, a rich premixed gas generation chamber for mixing the liquid fuel vaporized by the vaporizing means with the premixing air to generate a rich premixed gas, and the rich heat transfer means provided in the heat transfer means. A light premixed gas generation chamber for mixing the premixed gas and the dilution air to generate a light premixed gas; and a rich gas mixture chamber provided in the heat transfer means and communicating with the rich premixed gas generation chamber and the rich flame port. A combustion device comprising: a side opening; and a light-side opening provided in the heat transfer means and communicating the rich premixed gas generation chamber and the light premixed gas generation chamber. 2. The combustion apparatus according to claim 1, wherein an air opening for dilution is provided in the heat transfer means. 3. A rich flame port and a light flame port are alternately arranged on a circumference, and a flame holding cylinder whose side faces the rich flame port and the light flame port is provided. The combustion device according to claim 1, wherein 4. A rich flame port and a light flame port are alternately arranged on a circumference, and a projection having a side surface facing the rich flame port and the light flame port is integrally formed with a heat transfer means. The combustion device according to any one of claims 1 to 3, wherein the device is a heat receiving unit.