JPH0490402A - Combustion equipment for liquid fuel - Google Patents

Abstract

PURPOSE:To reduce NOx without losing the balance of the pressure loss of each section in the periphery of a combustion device by installing a plurality of heat sinks on the outer circumference of the front end section, to which the burner port of the outer casing of the combustion device faces. CONSTITUTION:In the liquid-fuel combustion equipment, a flame formed in a burner port 14 collides with the front end section of an outer casing 1 cooled by heat sinks 15 and is cooled, thus lowering the temperature of the flame. The balance of the pressure loss of each section in the periphery of a combustion device 3 is not lost at that time. Consequently, the concentration of NOx contained in a combustion waste gas is diminished because the temperature of the flame is lowered. Since secondary air for combustion from a secondary-air passing hole 17 collides with the heat sinks 15 by a guide member 18 positively, the temperature drops of contact sections with the flame of the outer casing 1 is kept excellent, and the concentration of NOx can be reduced by approximately 45%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a liquid fuel combustion device that mixes liquid fuel such as petroleum with combustion air and burns the mixture as a mixed gas in a flame hole.

[Prior Art] FIG. 5 is a cross-sectional view of a conventional liquid fuel combustion apparatus disclosed in, for example, Japanese Patent Laid-Open No. 2-78810. This combustion device includes a combustor 3 having an overall cylindrical shape and having an outer cylinder 2 and an inner cylinder 2 connected at one end by an end wall. A space between the outer cylinder 1 and the inner cylinder 2 is formed as an annular vaporization mixing chamber 4 having a bottom formed by an end wall. The inner cylinder 2 is open at both ends and serves as a passage through which secondary air for combustion passes. An air supply port 5 for introducing primary air for combustion is formed on the side of the end wall of the outer cylinder l, and a fuel injection nozzle 6 is attached to this air supply port 5 so as not to block the air supply port 5. ing.

The interior of the vaporization mixing chamber 4 has a spiral shape, for example, and a burner 7 is mounted on the open side in a lid-like manner while being pressed against a burner head 8. The combustor 3 itself is housed in an outer box 9 that forms a combustion enclosure body, and an outer peripheral secondary air passage 10 is formed between the outer box and the outer cylinder 1 of the combustor 3 to pass secondary air for combustion. ing.

Further, the internal space of the inner cylinder 2 is configured as an inner peripheral secondary air passage 11 through which secondary air for combustion passes.

In the figure, reference numeral 12 is a heater, and 13 is a combustion chamber formed by the main body of the combustion apparatus.

The combustion operation of the liquid fuel combustion device having the above configuration is as follows. That is, liquid fuel is supplied from the fuel injection nozzle 6 and primary air is supplied from the air supply port 5 into the vaporization mixing chamber 4 which is heated by the heater 12, and is vaporized and mixed while swirling in the vaporization mixing chamber 4. I'm curious. The air-fuel mixture is guided to a flame hole formed by the burner 7 and the burner head 8, and is ignited by an ignition means (not shown) to form a flame directed toward the outer cylinder 1 and combust. The combustion of the air-fuel mixture heats a heated fluid (not shown), and the heat necessary for vaporizing the liquid fuel, preheating the air-fuel mixture, etc. is recovered. In order to stabilize the flame in the flame hole, secondary combustion air is supplied from the outer peripheral secondary air passage 10 and the inner peripheral secondary air passage 11, respectively.

[Problems to be Solved by the Invention] In the conventional liquid fuel combustion apparatus described above, there is a problem that the temperature of the outer cylinder 1 is high and the decrease in flame temperature cannot be measured, so the concentration of NOx contained in the combustor gas is high. Ta. The pressure loss at various parts around the combustor is delicate, and it was difficult to reduce NOx without disrupting this balance.

This invention was made in order to solve such conventional problems, and the object is to obtain a liquid fuel combustion device that can achieve reduction in NOx without disturbing the balance of pressure loss in various parts around the combustor. It is.

[Means for Solving the Problems] A liquid fuel combustion device according to the present invention is configured such that a heat sink is provided at the tip of an outer cylinder to cool it with secondary air for combustion.

Further, in another liquid fuel combustion device according to the present invention, a guide member is provided in the secondary air passage so that the secondary air for combustion is directed toward the heat sink.

[Function] In this invention, the temperature of the tip of the outer cylinder facing the flame opening is lowered by heat radiation from the heat sink, and the flame temperature is lowered, so that the balance of pressure loss in various parts around the combustor is not disturbed. (It becomes possible to achieve a reduction in NOx.

In another aspect of the invention, the secondary air for combustion is directed toward the heat sink by the guide member, so that heat radiation from the heat sink is promoted and the flame temperature can be lowered.

[Embodiment] FIG. 1 is a sectional view showing a liquid fuel combustion device as an embodiment of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a perspective view of a combustor. As can be seen from this figure, this liquid fuel combustion device is characterized by the configuration of its flame forming section, and the configuration of other parts is the same as the conventional example described above.

Therefore, the same reference numerals are given to the same or corresponding configurations as those of the conventional example, and the description thereof will be omitted to avoid duplication.6 Characteristics of the liquid fuel combustion apparatus of this example are the burner 7. and a burner head 8, and faces a plurality of flame holes 14 that open radially toward the tip of the outer cylinder 1.
A plurality of heat dissipating plates 15 are integrally molded in the shape of a tooth row on the outer periphery of the tip. The heat sink 15 contacts combustion secondary air from the outer peripheral secondary air passage 10 between the outer box 9 and the combustor 3. Combustor fixing plate 1 fixing the combustor 3 to the outer box 9
6 is formed with a secondary air passage hole 17 for passing secondary air for combustion, and immediately after this secondary air passage hole 17, a guide member 18 for guiding the secondary air for combustion toward the heat sink 15 side is formed in the combustor. It is constituted by a part of the fixed plate 16.

In this liquid fuel combustion device as well, the air-fuel mixture can be combusted in the same way as the combustion operation described in the conventional liquid fuel combustion device. However, in the liquid fuel combustion device according to this example, the flame formed in the flame hole 14 hits the tip of the outer cylinder l which is cooled by the heat sink 15 and is cooled, so the temperature of the flame can be lowered. Of course, the balance of pressure loss in each part around the combustor 3 remains the same as before. Therefore, the concentration of NOx contained in the combustor gas will be reduced due to the lower flame temperature. Heat sink 1
5, the secondary air for combustion from the secondary air passage hole 17 hits the north pole by the guide member 18, so the temperature drop of the part of the outer cylinder 1 that comes into contact with the flame is maintained well, and NOx of about 45% is It becomes possible to reduce the concentration of

In addition, in the above embodiment, the heat sink 1 is arranged parallel to the center line of the combustor 3.
However, by forming the heat sink 15 at an angle of inclination with respect to the center line of the combustor 3, as shown in FIG. 4, the surface area of the heat sink 15 can be set wide.
Heat dissipation can be further improved, and the concentration of NOx can be effectively reduced.

[Effects of the Invention] As is clear from the above description of the embodiments, according to the present invention, the tip of the outer cylinder of the combustor that comes into contact with the flame is cooled by the secondary combustion air by the heat sink, and the temperature of the flame is reduced. Therefore, it is possible to achieve the effect of reducing NOx without destroying the balance of pressure loss in various parts around the combustor.

In addition, according to another invention, the guide member makes the contact between the combustion secondary air and the heat sink smooth, and the temperature at the tip of the outer cylinder of the combustor is effectively lowered, thereby achieving a reduction in NOx. can do.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of a liquid fuel combustion device as an embodiment of the present invention, FIG. 2 is a front view thereof, FIG. 3 is a perspective view of a combustor, and FIG. A perspective view of a combustor showing another embodiment, and FIG. 5 is a sectional view showing the configuration of a conventional liquid fuel combustion device. In the figure, 1 is an outer cylinder;
2 is an inner cylinder, 3 is a combustor, 4 is a vaporization mixing chamber, 7 is a burner,
9 is an outer box, 11 is an inner peripheral secondary air passage, 15 is a heat sink, 1
6 is a combustor fixing plate, 17 is a secondary air passage hole, and 18 is a guide member. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent - Masuo Oiwa (2 people) Fig.

Claims (1)

[Claims] (1) A combustor that is built into an outer box and has an outer cylinder and an inner cylinder, and is formed between the outer cylinder and the inner cylinder, and mixes liquid fuel and primary combustion air as a swirling flow and vaporizes the mixture. a combustion section having a vaporization mixing section, a burner that injects the mixed gas vaporized in the vaporization mixing section from a flame port toward the outer cylinder side to form a flame, and between the outer box and the outer case of the combustor. In the liquid fuel combustion device, the combustor is formed with a secondary air passage for supplying secondary air for combustion to the combustion section, and a plurality of heat sinks are provided on the outer periphery of the tip of the outer cylinder of the combustor facing the flame port. A liquid fuel combustion device characterized by: (2) The liquid fuel combustion device according to claim 1, characterized in that a guide member is provided in the secondary air passage to bring the secondary air for combustion into contact with the heat sink.