JPH06174210A - Liquid fuel-burning device - Google Patents

Abstract

PURPOSE:To make instantaneous start-up possible and lower the noise level both relating to the combustion and make the device structurally compact. CONSTITUTION:The fuel is jetted in a thin circular film from a fuel jet 39 provided at the tip of a fuel nozzle 35 and against the tip of this jetted fuel a stream of air fed from an air jet 62 is made to impinge to divide the fuel into fine particles. As a result, the thickness of the film of the fuel jetted in a thin circular film from the fuel nozzle becomes thinner and the jetting velocity slows down; furthermore, since a stream of air is made to impinge directly upon the tip of fuel which is in an unstable state, the fuel is divided into fine particles uniformly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel combustion apparatus used as a heat source for hot water supply / heating equipment.

[0002]

2. Description of the Related Art In recent years, there have been strong demands for instantaneous ignition, expansion of combustion amount adjustment range, noise reduction, and size reduction of petroleum combustion equipment.

Conventionally, the combustion methods of this type of liquid fuel combustion apparatus are roughly classified into those in which the fuel particles atomized by the atomizer are burned as they are, and those in which the liquid fuel is once vaporized and burned. . For example, in the former spray combustion device, as shown in FIG. 5, the liquid fuel supplied from the fuel tank 1 is pressurized by the electromagnetic pump 2 and is ejected from the pressure spray nozzle 3 through the supply pipe 4 to be atomized. Combustion chamber 6
Is sprayed on. On the other hand, the combustion air is supplied to the combustion chamber 6 by the blower fan 7 through the blower path 5. At this time, a combustion reaction with the liquid fuel sprayed from the pressure spray nozzle 3 was performed to form a flame.

In the latter vaporization and combustion apparatus, as shown in FIG. 6, the liquid fuel supplied from the fuel tank 8 passes through the oil feed pipe 10 by the oil feed pump 9 and the vaporization cylinder in which the electric heater 13 is embedded from the nozzle 11 to the nozzle. Droplets are sent out to the high temperature vaporization chamber 12 formed in 14 and are heated and vaporized. On the other hand, the combustion air is blown by the blower fan 15 into the air duct 1
It is supplied to the vaporization chamber 12 from the throat portion 17 provided on the outer periphery of the nozzle 11 through the nozzle 6. At this time, it was mixed with the vaporized fuel to form a flame at the flame port 18 provided in the combustion chamber 19.

[0005]

However, in the above-mentioned conventional spray combustion apparatus (FIG. 5), the flame length becomes large because the particle size of the liquid fuel ejected from the pressure spray nozzle 3 and atomized is large, and It was not possible to reduce the size, and further, combustion noise was not generated because the combustion noise was generated by the burst noise generated when the fuel particles boil rapidly due to the flame. Further, when the jet flow velocity is lowered to adjust the combustion amount, the atomization state is extremely deteriorated, the particle size of the fuel is increased, and the combustion becomes poor, so that the combustion amount adjustment range is extremely small.

The vaporizing and combusting device (FIG. 6) has a complicated structure because the liquid fuel has to be vaporized.
Moreover, a heating source for vaporization and power consumption were required.
Furthermore, since the preheating time for raising the temperature of the vaporization cylinder 14 and the vaporization chamber 12 is required, immediate ignition and combustion cannot be performed, and the instantaneousness of combustion rise is poor. As described above, the above-mentioned conventional liquid fuel combustion apparatus has a problem that the instantaneousness of combustion startup and noise reduction are insufficient and the adjustment range of the combustion amount is small.

The present invention is intended to solve the above-mentioned problems. It has a momentary rise of combustion, low noise, and a small size.
A liquid fuel combustion apparatus that expands the adjustment range of the combustion amount.

[0008]

In order to achieve the above object, the present invention provides a fuel nozzle having a liquid fuel supply portion to which liquid fuel is supplied, and a fuel nozzle connected to a tip of the fuel nozzle and an outer periphery of the tip of the fuel nozzle. A nozzle head having a fuel injection hole formed between the fuel injection hole and an outer periphery of the fuel nozzle so that the atomizing air collides with a predetermined position of the fuel jet ejected in a thin film form from the fuel injection hole. An air nozzle having an air ejection hole disposed outside, an air supply section for supplying air to the air ejection hole, an atomization section including a ventilation section formed between the fuel nozzle and the air nozzle, and the fog. An atomization chamber having an atomization section disposed inward, a primary air supply section for supplying primary air to the atomization chamber, a combustion section provided in communication with the atomization chamber downstream, and to the combustion section. Equipped with a secondary air supply unit that supplies air Than it is.

[0009]

According to the present invention, the thin-film fuel jet ejected from the fuel ejection hole has a thinner film thickness, the ejection speed is decelerated and small, and the fuel film formation state is unstable at a predetermined position. The kinetic energy of the air jet can be effectively utilized by directly colliding the atomization air with the air, and the relative velocity of the air and the fuel becomes large so that the atomization is promoted and the atomization is effective. When it is carried out, it becomes uniform fine particles, and the atomized state can be obtained in a wide control range. Further, since the atomized fuel particles are mixed with air and conveyed to the combustion section as a combustible mixture, instantaneous ignition combustion is possible and the size of the device can be reduced by shortening the flame. Further, since the fine particles are burned, combustion noise can be reduced.

[0010]

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

As shown in FIGS. 1 and 2, an atomizing section 21 is provided in the center of the inside of the atomizing chamber 20, and liquid fuel is pressurized from a fuel tank 22 by an electromagnetic pump 23 and pumped up. , And is supplied to the atomizing unit 21 via the fuel supply pipe 24. The atomizing air sent from the air supply means 25 is supplied to the atomizing unit 21 through the air supply pipe 26. A mixing plate 27 is provided in the upper part of the atomization chamber 20 on the downstream side of the atomization unit 21.
8 is formed, and the combustion section 29 is provided on the downstream side of the mixing chamber 28. Part of the air sent from the blower 30 is supplied to the atomization chamber 20 by the primary air supply unit 31. The fuel particles mixed with air in the mixing chamber 28 are uniformly dispersed by the pressure equalizing plate 32, supplied to the flame port 33 of the combustion unit 29, and burned. Further, a part of the air sent from the blower 30 is supplied to the combustion unit 29 by the secondary air supply unit 34, and this secondary air is supplied to the secondary air holes (not shown) subdivided by the flame port 33. To be done.

The details of the atomizing unit 21 will be described below. That is, the fuel nozzle 35 is provided with a liquid fuel supply portion 36 at the center thereof, a fuel passage 36a communicating with the liquid fuel supply portion 36 is formed at the tip end so as to face the outer periphery, and a protruding portion 37a of the nozzle head 37 is formed. Is connected with a fixing screw 38 to form a fuel injection hole 39 between the outer periphery of the tip of the fuel nozzle 35. The liquid fuel is supplied from the fuel supply pipe 24 to the liquid fuel supply unit 36, and the fuel passage 36
After passing through a, it passes through a gap 36b formed by the tip of the fuel nozzle 35 and the projecting portion 37a of the nozzle head 37 and is ejected from the fuel ejection hole 39 as a circular thin-film fuel jet L. A ventilation part 43 is formed between the fuel nozzle 35 and the air nozzle 40. The air nozzle 40 has an air supply portion 41 formed on the concentric outer circumference of the fuel nozzle 35, and an air ejection hole 42 is provided immediately below the tip of the outer circumference of the fuel jet L on the downstream side. The air ejection hole 42 is arranged at a position having a distance A from the tip of the fuel ejection hole 39. Then, the air is supplied to the air supply unit 41 through the air supply pipe 26, and the air ejection holes 42 to the fuel ejection holes 39.
The fuel jet L ejected in a more circular thin film shape is ejected toward a predetermined position.

The operation of the above configuration will be described.
When the power (not shown) is turned on, the electromagnetic pump operates,
The liquid fuel is pumped from the fuel tank 22 into a pressurized state, is supplied to the liquid fuel supply portion 36 in the fuel nozzle 35 through the fuel supply pipe 24, reaches the gap 36b through the fuel passage 36a, and is discharged from the fuel injection hole 39. A circular thin-film fuel jet L is ejected. At the same time, the air supply means 25
Is activated, and air is supplied to the air supply portion 41 through the air supply pipe 26 in a pressurized state and is jetted from directly below toward the fuel jet L which is jetted in a circular thin film shape from the air jet hole 42.
At this time, the air flow directly collides with a predetermined position of the circular thin-film fuel jet L in the jet direction of the fuel from directly below, and the circular thin-film fuel is sheared and atomized into fine particles.

In this case, since the liquid fuel ejected from the fuel ejection hole 39 is a circular thin film-shaped fuel jet L, its surface area increases toward the tip of the outer periphery, and its film thickness becomes thinner. Further, the fuel ejection speed is high immediately after the fuel is ejected from the fuel ejection hole 39, and is decelerated and becomes smaller as the distance from the fuel ejection hole 39 increases. In the formation of the circular thin film-shaped fuel jet L, the turbulence on the circular thin film grows from the stable state region La, then passes through the unstable region Lb to be split, and becomes a fuel droplet. In this process, the air ejection hole 42 is arranged at a predetermined position having a distance A from the tip of the fuel ejection hole 39, and is ejected from directly below toward a predetermined position of the fuel jet L ejected in a circular thin film shape. Since the kinetic energy of the air jet can be effectively utilized because it is provided in the above, compared with the parallel flow in which the jet directions of the fuel and the air are the same,
Further, since the air jet directly collides with the fuel jet L ejected in the shape of a circular thin film where the jet speed of the fuel is decelerated and becomes small, the relative velocity of the air and the fuel becomes large and atomization is further promoted. Further, the film thickness of the circular thin-film fuel jet L becomes thinner, and the unstable state (L
Since the air jet directly collides with the fuel jet of b) from directly below, atomization is effectively performed and atomized into fine particles having a uniform particle size. Then, the atomization state can be obtained in a wide adjustment range by the action of the shearing force due to the air jet flow, with respect to the atomization combustion device (FIG. 5) which ejects fuel from the conventional pressure atomization nozzle 3 and atomizes it. . Next, the fuel nozzle 35
The operation of the ventilation part 43 formed between the air nozzle 40 and the air nozzle 40 will be described. FIG. 3 shows a configuration in which the ventilation part 43 is not formed between the fuel nozzle 35 and the air nozzle 40. In this case, the inside of the air ejection hole 42 surrounded by the fuel jet L and the air flow (g) has a negative pressure. In the region P, the fuel jet L is drawn downward and partially contacts the inner peripheral end surface 40a of the air ejection hole 42 to cause wetting. Coarse particles of the wetting liquid are mixed during atomization, which hinders atomization and homogenization. However, in the present invention, since the ventilation portion 43 is formed between the fuel nozzle 35 and the air nozzle 40, the negative pressure region disappears, wetting can be avoided, and factors that hinder atomization and homogenization can be eliminated. The liquid fuel is sprayed into the atomization chamber 28 as a group of fine particles having a uniform particle diameter by the action of the atomization unit 20. Then, while being mixed with the air supplied from the primary air supply unit 31, it is introduced into the mixing chamber 28 and sufficiently mixed. This mixture of fuel and air is sent to the combustion unit 29 while further increasing the degree of mixing, and the pressure equalizing plate 32 is provided.
By this, it is uniformly dispersed in the entire combustion section 29, becomes a combustible air-fuel mixture, is supplied to the flame port 33, and becomes premixed combustion. At this time, the combustion air is supplied to the flame port 33 from the secondary air supply unit 34, so that a short flame is formed.

As described above, according to the liquid fuel combustion apparatus of the embodiment, the film thickness of the fuel jet L ejected from the fuel nozzle 35 in the shape of a circular thin film is thinner, the ejection speed is decelerated and small, and the fuel film is formed. In this state, air for atomization is directly collided with a predetermined position in an unstable state to form uniform fine particles, and the fine particles are supplied to the flame port 33 while being mixed with the air supplied from the primary air supply unit 31. Since the combustion air is supplied from the secondary air supply unit 34, a good combustion state can be obtained. And this atomizing unit 2
According to No. 1, since the atomization amount can be adjusted widely, atomization of the liquid fuel can be ensured even when the combustion amount is small, and the adjustment range of the combustion amount can be expanded. Further, the atomizing air acts as a part of the primary air, and the air supplied from the primary air supply unit 31 conveys the atomized liquid fuel to the combustion unit 29 and acts as premixed air, so that the flame is generated. Premixed combustion can be performed at the mouth 33, and the combustion speed can be made higher than that of diffusion combustion. Further, the secondary air supply unit 3
Combustion air is supplied from No. 4, so that the flame length formed at the flame port 33 is shortened and the apparatus can be downsized. Then, the fine particles of the liquid fuel and the air conveyed to the combustion unit 29 become a combustible air-fuel mixture, so that ignition combustion can be performed instantly. Furthermore, when the particles of the liquid fuel are large as in the conventional case, the combustion noise resulting from the burst noise when the particles are rapidly boiled by the flame can be reduced by atomizing the liquid fuel to reduce the noise of the device. Can be realized.

Next, another embodiment of the present invention will be described with reference to FIG. In the figure, the difference from the above-mentioned embodiment is that the air ejection holes 42 are configured so that the air flow (arrow g) collides with the fuel jet direction (arrow 1) at an angle (θ) of 90 degrees or more. is there. According to the configuration of the other embodiment, the relative velocity of the air and the fuel becomes larger, and the kinetic energy of the air jet can be effectively utilized, so atomization is further promoted and the above-mentioned effect can be improved.

[0017]

As is apparent from the above embodiments, the liquid fuel combustion apparatus of the present invention has the following effects. (1) The film thickness of the fuel jet ejected from the fuel nozzle in the shape of a circular thin film is thinner, the ejection speed is decelerated and small, and the state of fuel film formation is unstable. By directly colliding with each other, uniform fine particles can be obtained. (2) Since the ventilation part is formed between the fuel nozzle and the air nozzle, the negative pressure region disappears and the wetting is avoided to atomize the particles.
It is possible to eliminate the factors that hinder homogenization. (3) Since the air jet holes are configured so that the air streams collide with each other at an angle of 90 degrees or more with respect to the fuel jet direction, the relative velocity of the air and the fuel becomes larger, and the kinetic energy of the air jet is effectively utilized. It is possible to further promote atomization. (4) Uniform and fine fuel particles are supplied to the flame port 33 while being mixed with the air supplied from the primary air supply unit 31, and the combustion air is supplied from the secondary air supply unit 34. Therefore, a good combustion state can be obtained. (5) Since the atomization state can be obtained in a wide adjustment range by the action of the shearing force due to the application of the air jet, the atomization of the liquid fuel can be secured even when the combustion amount is small, and the adjustment range of the combustion amount is expanded. be able to. (6) The atomizing air acts as a part of the primary air,
The air supplied from the primary air supply section conveys the atomized liquid fuel to the combustion section and also acts as premixed air, so that premixed combustion can be performed at the flame mouth, and the combustion speed is higher than that of diffusion combustion. Can also be larger. Further, the combustion air is supplied from the secondary air supply unit, so that the flame length formed at the flame port is reduced and the device can be downsized. (7) Since the fine particles of the liquid fuel and the air, which have been conveyed to the combustion section, become a combustible mixture, ignition combustion can be performed instantly. (8) Since the combustion of uniform and minute fuel particles is performed, it is possible to reduce the combustion noise caused by the explosion noise when the conventional large fuel particles are rapidly boiled by the flame by atomizing the liquid fuel. The noise of the device can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a liquid fuel combustion device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of an atomizing section in the same device.

FIG. 3 is a cross-sectional view of an essential part for explaining the action of an atomizing unit in the same device.

FIG. 4 is a cross-sectional view of essential parts of a liquid fuel combustion apparatus according to another embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a conventional liquid fuel combustion device.

FIG. 6 is a cross-sectional view of essential parts of another conventional liquid fuel combustion apparatus.

[Explanation of symbols]

 20 Atomization chamber 21 Atomization section 29 Combustion section 31 Primary air supply section 34 Secondary air supply section 35 Fuel nozzle 36 Liquid fuel supply section 37 Nozzle head 39 Fuel ejection hole 40 Air nozzle 41 Air supply section 42 Air ejection hole 43 Aeration Department

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norio Nobuya 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A fuel nozzle having a liquid fuel supply portion to which liquid fuel is supplied, and a nozzle head connected to a tip of the fuel nozzle to form a fuel injection hole between the outer periphery of the tip of the fuel nozzle. Atomizing air is supplied so as to collide with a predetermined position of the fuel jet ejected in a thin film form from the fuel ejecting hole provided on the outer periphery of the fuel nozzle, and an air ejected outside the fuel ejecting hole An air nozzle having a hole and an air supply part for supplying air to the air ejection hole, an atomizing part formed of a ventilation part formed between the fuel nozzle and the air nozzle, and the atomizing part The atomization chamber, a primary air supply unit that supplies primary air to the atomization chamber, a combustion unit that is provided in communication with the atomization chamber downstream, and an air supply unit that supplies air to the combustion unit. A liquid fuel combustion apparatus having a secondary air supply unit. 2. The liquid fuel combustion apparatus according to claim 1, wherein the air ejection holes are provided so that an angle formed by the fuel jet direction and the air flow direction is 90 degrees or more.