JPH0454130B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a combustor used in a vehicle heating system.

[Conventional technology] Unlike a vehicle heating system that uses the exhaust heat of an internal combustion engine, this system supplies combustion gas from a combustor to the engine's intake port via a heat exchanger, and at the same time supplies air heated by the heat exchanger to the vehicle. A heating system for a vehicle that blows air into a room has been proposed, for example, in Japanese Patent Application No. 199362/1983.

In the above-described combustor, the air supplied to the combustion chamber causes convection around the ignition glow plug, which prevents the temperature of the ignition glow plug from increasing and impairs ignitability. Since the fuel nozzle is not located in the center of the combustion chamber, the air-fuel mixture is unevenly distributed, impairing the stability of combustion.

[Problems to be Solved] In view of the above-mentioned problems, an object of the present invention is to provide a combustor that improves the distribution of air-fuel mixture in the combustion chamber and improves ignitability and combustion stability. .

[Means for Solving the Problem] In order to achieve the above object, the present invention has a configuration in which a combustion tube is disposed inside a cup-shaped housing connected to an intake duct, and an annular air preheating chamber is provided between the two. A baffle plate having a notched passage on the periphery is fitted into the combustion tube to partition a vaporizing chamber and a combustion chamber having an outlet, and a plurality of baffle plates are provided on the peripheral wall of the combustion tube to communicate the air preheating chamber and the combustion chamber. An air hole is provided and the finned fuel supply pipe is supported by diagonally penetrating the housing and combustion cylinder.
A fuel nozzle that protrudes into an opening in the center of the rectifier plate is connected to the tip of the fuel supply pipe, a vaporizing glow plug is inserted into the base end of the fuel supply pipe, and an ignition glow plug is placed in the vaporizing chamber. be.

[Operation] Air in the intake duct flows into the combustion chamber through the air preheating chamber and the air holes in the combustion cylinder. A portion of the air flows into the vaporization chamber through a notched passage on the periphery of the baffle plate.

On the other hand, the fuel in the fuel supply pipe is heated by the vaporizing glow plug, and is blown from the fuel nozzle through the center opening of the baffle plate, mixed with air, and ignited to the ignition glow plug in the vaporizing chamber. The ignited fuel flows into the combustion chamber through a notched passage on the periphery of the baffle plate, mixes with air from the air holes, burns completely, and is sent from the outlet to the heat exchanger.

[Embodiment of the Invention] As shown in FIG. 1, a combustion cylinder 3 made of ceramic is inserted into the inner end of a substantially cup-shaped housing 7 formed from a heat-resistant metal plate, with a sleeve 1 in between. The outer end of the combustion tube 3 is held down by a sleeve 5 having a flange 5a. sleeve 5
is fitted into the housing 7, and the flange 5a abuts against the stepped portion 7a of the housing 7. The step portion 7a, the flange 5a, and the flange 21a of the connecting tube 21 are coupled with a plurality of bolts (not shown) with the gasket 6 interposed therebetween. The connecting tube 21 is connected to the inlet of a heat exchanger (not shown) that heats heating air.

A dump ring 9 made of a metal plate such as stainless steel and having a U-shaped cross section is interposed between the end of the combustion tube 3 and the sleeve 1, and a similar dump ring 4 is interposed between the end of the combustion tube 3 and the sleeve 5. The combustion cylinder 3 is elastically supported inside the housing 7 by damping rings 9 and 4. An annular air preheating chamber 19 is defined between the housing 7 and the combustion tube 3.
Combustion air flows from the intake duct 20 to the air preheating chamber 1
9. The air is introduced into the combustion chamber 18 through a large number of air holes 14. A cup-shaped cap 8 made of heat-resistant metal is fitted into the inner end of the combustion tube 3, and a rectifying plate 2 made of ceramic is fitted into the inner end of the cap 8. The inside of the fuel cylinder 3 is connected to the vaporization chamber 17 by the baffle plate 2.
and a combustion chamber 18. An ignition glow plug 16 is supported on the peripheral wall of the vaporizing chamber 17.

The fuel nozzle 23 projects from an opening 22 at the center of the baffle plate 2 toward the ignition glow plug 16 of the vaporization chamber 17 . The fuel nozzle 23 is connected to the tip of a fuel supply pipe 26 of the fuel vaporizer 11 made of ceramics. The vaporizing glow plug 13 screwed onto the base end of the fuel supply pipe 26 has its heat generating part 13a inserted into the cylindrical part 30 of the fuel supply pipe 26, and the fuel pipe 12 is connected to the cylindrical part 30. The tip of the fuel supply pipe 26 protruding into the combustion chamber 18 is provided with a number of deep annular grooves on its outer peripheral surface to form a fin 24 . The fuel supply pipe 26 is attached to a mounting member 25 supported on the housing 7.
The seal 10 is applied and fixed by the fixing means 27.

As shown in FIG. 2, the rectifier plate 2 is a disc-shaped plate made of ceramics, and has a plurality of wide notches 2a on its periphery, and a notch passageway is formed between it and the cylindrical portion of the cap 8. form 33.

Next, the operation of the combustor according to the present invention will be explained. The air sucked in from the intake duct 20 is heated in the air preheating chamber 19, and is heated through the air holes 14 of the combustion tube 3.
It flows into the combustion chamber 18 from there. A part of the air passes through a cutout passage 33 in a part of the baffle plate 2 (in the illustrated example, the lower cutout passage 33 adjacent to the wall of the combustion tube 3 on which the fuel vaporization device 11 is supported) and enters the vaporization chamber 17. The remainder is mixed with the fuel in the combustion chamber 18 and used for combustion, and flows from the outlet 32 through the connecting tube 21 to the heat exchanger.

On the other hand, the fuel sent from the fuel pipe 12 to the fuel supply pipe 26 is
The fuel is heated and vaporized, and is sprayed from the fuel nozzle 23 through the opening 22 of the baffle plate 2 to the heated portion of the ignition glow plug 16 while mixing with air. The mixture of fuel and air is ignited by the ignition glow plug 16 and flows into the combustion chamber 18 through the cutout passage 33 above the baffle plate 2 .

During steady operation, the fins 24 are heated in the combustion chamber 18, so even if the energization to the vaporizing glow plug 13 is stopped, the fuel in the cylindrical portion 30 of the fuel supply pipe 26 is vaporized.

As mentioned above, the fuel is vaporized and ignited in the vaporization chamber 17, flows into the combustion chamber 18 along the inner circumferential wall of the combustion tube 3 via the notched passage 33, mixes with air from the air hole 14, and is completely combusted. and is discharged from the outlet 22. At the same time, the air sucked from the lower air hole 14 is sucked into the vaporization chamber 17 along the inner peripheral wall of the combustion tube 3 through the lower notch passage 33 while being heated by the combustion gas.

[Effects of the Invention] As described above, the present invention has a combustion tube disposed inside a cup-shaped housing connected to an intake duct, an annular air preheating chamber defined between the two, and a cutout passage provided at the periphery. A rectifying plate having a housing and a combustion chamber is fitted into the combustion tube to partition a vaporization chamber and a combustion chamber having an outlet, and a number of air holes are provided in the peripheral wall of the combustion tube to communicate the air preheating chamber and the combustion chamber. Support the finned fuel supply pipe by penetrating it diagonally, connect the fuel nozzle that protrudes into the opening provided in the center of the rectifying plate to the tip of the fuel supply pipe, and attach the vaporizing glow plug to the base end of the fuel supply pipe. The fuel heated by the vaporizing glow plug in the fuel supply pipe flows from a single fuel nozzle, and the air in the combustion chamber flows through the center of the rectifying plate surrounding the fuel nozzle. From the opening, the mixture becomes a mixture and is supplied to the ignition glow plug in the vaporization chamber, where it is quickly ignited, so it is ignited in the vaporization chamber by vibrations and changes in the flow rate of air and combustion gas in the combustion chamber. There is no risk of the fuel being blown out.

In particular, as the fuel is ejected from the fuel nozzle into the vaporization chamber, it vaporizes and mixes with the air, so once ignited, a stable combustion state is achieved and high-speed combustion corresponding to the intake speed of the engine is achieved.

In a steady state of combustion, the fuel supply pipe is heated by the combustion gas through the fins, so even if the power to the vaporizing glow plug is stopped, the fuel is vaporized in the fuel supply pipe, reducing the power consumption of the vaporizing glow plug. .

The air-fuel mixture ignited in the vaporization chamber passes through the notched passages on the periphery of the baffle plate and flows into the combustion chamber in a distributed manner over almost the entire surface of the combustion chamber, where it mixes with air from the air holes in the combustion tube.
Stable combustion can be achieved even if the combustion chamber has a relatively small volume.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a combustor according to the present invention, and FIG. 2 is a front view of a rectifying plate. 2: Straightening plate, 3: Combustion tube, 7: Housing, 1
1: Fuel vaporization device, 13: Vaporization glow plug, 1
4: Air hole, 16: Ignition glow plug, 17: Vaporization chamber, 23: Fuel nozzle, 24: Fin, 26:
Fuel supply pipe, 32: outlet.

Claims (1)

[Claims] 1 A combustion cylinder is placed inside a cup-shaped housing connected to the intake duct, an annular air preheating chamber is defined between the two, and a baffle plate with a notched passage on the periphery is fitted into the combustion cylinder to perform vaporization. A combustion chamber having a chamber and an outlet is divided, a number of air holes are provided in the peripheral wall of the combustion tube to communicate the air preheating chamber and the combustion chamber, and a finned fuel supply pipe is provided diagonally through the housing and the combustion tube. Connect the fuel nozzle that protrudes into the opening provided in the center of the rectifying plate to the tip of the fuel supply pipe, insert the vaporization glow plug into the base end of the fuel supply pipe, and place the ignition glow plug in the vaporization chamber. A combustor characterized by: