JPS62129611A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To change the injection pressure of liquid fuel without spoiling burning properties and permit to control the amount of combustion with a wide range by a method wherein a flow regulating tube, heated to the condition of a high temperature by combustion heat during combustion and heating fuel mist injected from injection nozzles arranged on the bottom plate of an inner tube, is provided in the inner tube under a condition that the opening end thereof is faced to the side of the injection nozzles. CONSTITUTION:A flow regulating tube 19 is arranged in an inner tube 11 near air injection ports 14 while the flow regulating tube 19 is heated to the condition of high temperature and red heat by combustion heat during combustion. As a result, the mist of the fuel, injected from a spray nozzle 17, is heated to permit to prevent imperfect combustion. Further, the outer peripheral surface of the flow regulating tube 19 is formed so that the outer diameter of the tube 19 reduces gradually from the side of an opening end 19a toward the side of a closing end 19b, therefore, the outflow speed of combustion gas may be uniformed substantially so as to cope with the change of flow amount of combustion gas in a space between the inner peripheral surface of the inner tube 11 and the outer peripheral slanted surface of the flow regulating tube 19 while the stagnating time of unburnt gas may be lengthered whereby perfect combustion may be contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a liquid fuel combustion device that vaporizes and burns liquid fuel.

[Technical background of the invention]

Generally, there is a liquid fuel combustion apparatus having the configuration shown in FIG. 9. In FIG. 9, reference numeral 1 denotes an inner cylinder whose one end is opened as a flame port 2 of a secondary flame chamber and whose other end is closed by a bottom plate 3. A flame holder 4 is disposed at the flame port 2 of the inner cylinder 1 in order to stabilize flame formation at the flame port 2. Further, a large number of air jet holes 5 are formed on the peripheral wall surface of the inner cylinder 1. Further, an outer cylinder 6 is disposed outside the inner cylinder 1, and an air flow passage 7 is formed between the outer cylinder 6 and the inner cylinder 1. Further, a spray nozzle 8 for spraying liquid fuel is disposed approximately at the center of the bottom plate 3 of the inner cylinder 1, and a spark plug 9 is disposed near the spray nozzle 8. During operation of this liquid fuel combustion device, combustion air is introduced into the air flow passage 7 between the outer cylinder 6 and the inner cylinder 1 by a blower fan (not shown), and air is introduced into the air jet hole 5 on the peripheral wall surface of the inner cylinder 1. The liquid fuel is injected into the inner cylinder 1 from a spray nozzle 8 in an atomized state, and is ignited by a spark plug 9. The combustion is performed in a state where a primary flame a is formed in the vicinity of the air jet holes 5 of the inner cylinder 1, and a secondary flame a is formed on the frame holder 4, respectively.

[Problems in the Background Art] In this type of liquid fuel combustion device, if the spray pressure of the liquid fuel is varied by a pump (not shown) to adjust the spray amount and the capacity of the liquid fuel combustion device is varied, the following will occur. Problems may occur. That is, if the capacity of the liquid fuel combustion device is to be improved, the spray pressure is increased. In this case, the spray pattern of the liquid fuel sprayed from the spray nozzle 8 is such that the fuel spray is diffused in the area of the generatrix A defined by the spray angle θ of the spray nozzle 8, as shown by the dotted line in FIG. Therefore, there is no problem. However, when the spray pressure is lowered to reduce the capacity of the liquid fuel combustion device, the average particle diameter d of the sprayed fuel becomes coarser, resulting in incomplete combustion.

Generally, the relationship between the spray pressure P and the average particle diameter d is expressed by equation (1).

d = 207 X W"" X l' X P-0°
46 , .
/5) As shown in equation (1), as the spray pressure P decreases, the average particle diameter d increases. Furthermore, when the spray pressure P is lowered, the spray pattern of the liquid fuel sprayed from the spray nozzle 8 is reduced to a tulip shape as shown by the dashed line B in FIG. Since the air ejection speed decreases as it moves away from the air ejection holes 5, the mixing of the fuel and air deteriorates, resulting in incomplete combustion.

Furthermore, the coarse fuel particles collide with the red-hot flame holder 4, and some of them are gasified and burned, but most of them fall from the wall of the frame holder 4 onto the surface of the inner cylinder 1, and from the air jet holes 5. It is dangerous because it is emitted unburned to the outside by the ejected airflow, and the odor of the combustion exhaust gas is also strong.

In other words, when trying to control the capacity of a conventional liquid fuel combustion device by changing the spray pressure, especially when the capacity is reduced, large amounts of soot and carbon monoxide (Co) are generated, and odor is emitted. There was a problem that problems such as the occurrence of problems occurred.

[Purpose of the invention]

An object of the present invention is to provide a pressure spray type liquid fuel combustion device that enables significant control of the amount of combustion by changing the injection pressure of liquid fuel without impairing combustibility. It is something.

[Summary of the invention]

In this invention, one end is opened as a flame port for secondary flame,
The other end is closed by the bottom plate, and an inner cylinder is provided in which a large number of air jet holes are formed on the peripheral wall surface, and a combustion chamber for the primary flame is formed inside, and an air flow passage is formed on the outside of this inner cylinder. A liquid fuel in which an outer cylinder is disposed, and a spray nozzle for spraying liquid fuel is disposed on the bottom plate of the inner cylinder, and the amount of combustion is adjusted according to changes in the spray pressure of the fuel injected from the spray nozzle. In combustion equipment, one end is open.

A closed end is formed on the other end side, and the opening end of the rectifier cylinder is heated to a high temperature state by combustion heat during combustion to heat the fuel spray injected from the spray nozzle, with its open end facing the spray nozzle side. It is characterized in that it is provided in the inner cylinder in a state in which

[Embodiments of the invention]

1 and 2 show a first embodiment of the invention. FIG. 1 shows a schematic configuration of the main parts of a liquid fuel combustion device, in which one end of 11 is opened as the flame port 12 of the 26 primary flame chamber, and the narrow end is the bottom plate 11.
This is an internal station blocked by 3. A large number of air jet holes 14 are formed on the peripheral wall surface of the inner cylinder 11.
A primary flame a is formed inside this inner cylinder 11. Further, an outer cylinder 15 is disposed outside the inner cylinder 11, and an air flow passage 16 is formed between the outer cylinder 15 and the inner cylinder 11. Further, a spray nozzle 17 for spraying liquid fuel is disposed approximately at the center of the bottom plate 13 of the inner cylinder 11, and a spark plug 18 is disposed near the spray nozzle 17.

On the other hand, a rectifying cylinder 19 is disposed inside the inner cylinder 11 . As shown in FIG. 2, the flow straightening tube 19 is a substantially truncated conical cylinder, with an open end 19a at one end (large diameter side) and a closed end 19a at the other end (small diameter side). 19b are formed respectively. Furthermore, the rectifier tube 19 is installed with its open end 19a facing the spray nozzle 17 and coaxially arranged with the center axis of the spray nozzle 17. Also,
The rectifying cylinder 19 has a pair of cross bins 2 attached to the outer cylinder 15.
0a, 20b. In this case, the cross bins 20a, 20b are arranged substantially perpendicular to each other. Note that the rectifying tube 19 may be made of metal with high heat resistance, or may be formed of a ceramic material.

Next, the operation of this liquid fuel combustion device will be explained.

First, when increasing the capacity of the liquid fuel combustion device, a large amount of air is supplied by rotating a blower fan (not shown) provided in the air flow passage 16, and the l1jIn pressure is increased by a pump (not shown) to blow the spray nozzle. Fuel is injected from 17. That is, combustion air is passed through the air flow path 1 between the outer cylinder 15 and the inner cylinder 11 by a blower fan (not shown).
6, and the air is introduced into the inner cylinder 11 through the air jet holes 14 and 14 on the peripheral wall surface of the inner cylinder 11.
... is injected into the inner cylinder 11 from the spray nozzle 17, and the liquid fuel is atomized into the inner cylinder 11 from the spray nozzle 17.
is injected into the inside of the cylinder and ignited by the spark plug 18, and a primary flame a and a secondary flame a are formed on the flame a and flame a in the vicinity of the air jet holes 14 of the inner cylinder 11, respectively. It is designed to be burned in the same condition as before. In this case, the spray pattern of the liquid fuel sprayed from the spray nozzle 17 is such that the fuel spray is diffused in the area of the generatrix A defined by the spray angle θ of the spray nozzle 17, as shown by the dotted line in FIG. It has become.

In addition, when the capacity of the liquid fuel combustion device is to be reduced, a small amount of air is supplied by rotating a blower fan (not shown) provided in the air flow passage 16, and the spray pressure is lowered by a pump (not shown), etc. Fuel is injected from 17. In this case, the spray pattern of the liquid fuel sprayed from the spray nozzle 17 is in a state of contracting into a tulip shape, as shown by the dashed line B in FIG. In this case, inside the inner cylinder 11, there is a rectifying cylinder 1 near the air jet hole 14.
9 is disposed, the straightening tube 19 is heated to a high temperature state by combustion heat during combustion, and becomes red-hot. As a result, even if the particle size of the sprayed fuel injected from the spray nozzle 17 becomes coarse and the spray pattern shrinks to a tulip shape, the inner surface of the concave rectifying tube 19 stops receiving the fuel.
The heat of the rectifier tube 19 can heat the sprayed fuel to promote gasification of the sprayed fuel, thereby preventing incomplete combustion.

Furthermore, since the rectifying cylinder 19 is formed of a substantially truncated conical cylinder whose outer circumferential surface is inclined so that the outer diameter gradually decreases from the open end 19a side to the closed end 19b side, Inner peripheral surface of inner cylinder 11 and rectifying cylinder 19
It is possible to change the cross-sectional area of the combustion gas in the space between the slanted surface of the outer periphery of the combustion gas into a state where it gradually increases from the upstream side to the downstream side. Therefore, in accordance with the change in the flow rate of combustion gas, the flow rate of combustion gas gradually increases from the upstream side to the downstream side in the space between the inner peripheral surface of the inner cylinder 11 and the outer peripheral inclined surface of the straightening cylinder 19. The cross-sectional area of the combustion gas in the space between the inner circumferential surface of the inner cylinder 11 and the inclined surface on the outer periphery of the straightening tube 19 can be changed by It is possible to approximately equalize the outflow velocity of combustion gas in the space between the outer peripheral inclined surface and the outer peripheral inclined surface. Therefore, the inner cylinder 1-1
The residence time of unburned gas in the space between the inner peripheral surface of 0 to 1 and the inclined surface of the outer periphery of the straightening cylinder 19 can be increased,
Complete combustion can be promoted.

Further, the opening end 19a of the rectifying tube 19 is connected to the spray nozzle 17.
The spray area 1fiP inside the generatrix A defined by the spray angle θ
Because it was installed inside the
The opening end 19a of the straightening tube 19 is set at the spray angle θ of the spray nozzle 17.
It is possible to reliably prevent the line from intersecting with the bus line A defined by Therefore, when increasing the capacity of a liquid fuel combustion device, a so-called follow-cone spray pattern is formed in which most of the liquid fuel is atomized on the generatrix A defined by the spray angle θ of the spray nozzle 17. It is possible to prevent the sprayed fuel from condensing at the opening m19a of the rectifier tube 19 when the temperature of the rectifier tube 19 is low at the initial stage of ignition.

Regarding the position of the opening end 19a of the straightening tube 19, when the minimum combustion amount is 5 to 6000 kcal/H, the opening end 19a of the straightening tube 19 is located at the most upstream end where the primary flame a is formed, as shown in FIG. The optimum position is slightly upstream of the air nozzle 14a, and the minimum combustion amount is 10,000k.
When the temperature is about cal/H, the air ejection hole 14. Similar effects were obtained in experiments even if the mounting position was changed to position b. The position of the open end 19a of the rectifier m19 is selected depending on the minimum fuel limit, but it may be located near the air jet hole at the most upstream end where the -order flame a is formed, for example, 14a or '14b.

Note that the present invention is not limited to the first embodiment described above. For example, in the first embodiment, among the air ejection holes 14 of the inner cylinder 11, the air ejection hole 14a at the most upstream end where the -order flame a is formed is included in the direction perpendicular to the central axis of the spray nozzle 17. The base 1i! is defined by the spray angle θ of the spray nozzle 17 on the upstream side of the virtual cross section S formed in the spray nozzle 17. When the virtual cross section S forming the boundary line of the spray area P inside A and the generatrix A defined by the spray angle θ of the spray nozzle 17 intersect with each other, the maximum diameter d in the spray area P
2 is smaller than the inner diameter dimension d' of the inner cylinder 11), but as in the second embodiment shown in FIG. 1
When the generatrix A defined by the spray angle θ of 7 does not intersect with each other (the maximum diameter d2 within the spray area P and the inner cylinder 1
1) may be the same as the inner diameter dimension d- of 1.

Further, the rectifying tube 19 is not limited to a truncated conical shape, but as shown in the third embodiment shown in FIG. M4 and FIG.
, the diameter of the closed end 19b may be O). Furthermore, as in the fourth embodiment shown in FIG. 6 and FIG.
1-The diameter of the closed end 19b is da). Further, as in the fifth embodiment shown in FIG. 8, the rectifying cylinder 19 may be formed of a substantially bowl-shaped cylinder with a curved conical inclined surface. Furthermore, it goes without saying that various other modifications can be made without departing from the gist of the invention.

〔Effect of the invention〕

According to this invention, an open end is formed on one end side and a closed end is formed on the other end side, and the fuel is heated to a high temperature state by combustion heat during combustion and is injected from a spray nozzle disposed on the bottom plate of the inner station. The rectifying tube that heats the spray is installed inside the inner tube with its open end facing the spray nozzle, so the injection pressure of the liquid fuel can be changed to significantly increase the combustion amount without impairing combustibility. A pressure spray liquid fuel combustion device that can be controlled can be provided.

[Brief explanation of drawings]

1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a vertical cross-sectional view showing a schematic configuration of the main parts of a liquid fuel combustion device, and FIG. 2 is a perspective view showing a rectifying tube. 3 and 3 are vertical sectional views showing the schematic structure of the main parts of a second embodiment of the present invention, and FIGS. 4 and 5 show a third embodiment of the invention, and FIG. 5 is a longitudinal sectional view of the same; FIGS. 6 and 7 show a fourth embodiment of the present invention; FIG. 6 is a perspective view of the rectifying tube; FIG. 7 is a longitudinal sectional view of the same, FIG. 8 is a longitudinal sectional view of a straightening tube showing a fifth embodiment of the present invention, and FIG. 9 is a longitudinal sectional view showing a schematic configuration of main parts of a conventional liquid fuel combustion device. It is. 11... Inner cylinder, 12... Flame port, 13... Bottom plate,
14... Air jet hole, 15... Outer cylinder, 16... Air flow path, 17... Spray nozzle, 19... Straightening tube,
19a...open end, 19b...closed end, a...-
Secondary flame, b...Secondary flame, θ...Spray angle, A...
Generatrix, P... spray area. Applicant's agent Patent attorney Takehiko Suzue = 15-r Figure 3 ■ d 1.6 Old "Time Figure 8 Figure 9 □ CA

Claims (3)

[Claims] (1) One end is opened as a flame port for the secondary flame, the other end is closed by the bottom plate, and a large number of air injection holes are formed on the peripheral wall surface, forming a combustion chamber for the primary flame inside. an outer cylinder that forms an air flow path is disposed on the outside of the inner cylinder, and a spray nozzle for spraying liquid fuel is disposed on the bottom plate of the inner cylinder, and the liquid fuel is injected from the spray nozzle. In a liquid fuel combustion device that adjusts the combustion amount according to changes in the spray pressure of fuel, an open end is formed at one end and a closed end is formed at the other end, and the combustion heat reaches a high temperature state during combustion. A liquid fuel combustion device characterized in that a rectifier tube that heats the fuel spray injected from the spray nozzle is provided in the inner tube with its open end facing the spray nozzle side. (2) Claim (1) characterized in that the outer peripheral surface of the rectifying tube is inclined such that the outer diameter gradually decreases from the open end side to the closed end side. The liquid fuel combustion device described in . (3) The rectifier tube is installed with its open end inserted inside the spray area inside the generatrix defined by the spray angle of the spray nozzle. The liquid fuel combustion device according to item 1) or item (2).