JPH0612333Y2 - Combustor for hot-fire heaters for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a combustor of a combustion heater for a vehicle.

(Prior Art and Problems Thereof) Conventionally, as a combustor of a combustion type heater for a vehicle, there is, for example, Japanese Patent Application No. 61-123534 filed by the applicant of the present application.

Generally, a combustor of a conventional combustion heater for a vehicle supplies liquid fuel into the combustion chamber inside the combustion cylinder, and at the same time, introduces combustion air introduced around the combustion cylinder into the combustion chamber from air inlet holes on the peripheral wall of the combustion cylinder. The air-fuel mixture is introduced, and the air-fuel mixture of the introduced combustion air and the vaporized liquid fuel is ignited and burned in the combustion chamber.

However, in such a conventional combustor, since cold combustion air is introduced around the combustion cylinder and the combustion cylinder is constantly cooled by the combustion air, (1) the air-fuel mixture is ignited in the combustion chamber. Since the ambient temperature of the combustion chamber becomes lower than the temperature of the central part when it is burned, the incomplete combustion occurs in part and the combustion performance is poor. (2) Due to this incomplete combustion, the inner circumference of the combustion cylinder Since the carbon adheres to the surface and the inner peripheral surface of the heat exchanger connected to the combustor, the durability of the combustion cylinder and the heat exchanger is poor, and (3) heating is stopped due to poor combustion performance. There is a problem that the extinguishing time until the combustion of the air-fuel mixture disappears is long and a large amount of blue-white smoke is emitted when the combustion disappears.

(Purpose of the Invention) The present invention has been made in view of such conventional problems, and prevents combustion air from contacting the outer peripheral surface of the combustion cylinder to improve combustion performance and durability. An object of the present invention is to provide a combustor for a combustion heater for a vehicle, which is improved and which reduces the emission amount of blue-and-white smoke when the combustion of the air-fuel mixture disappears.

(Means for Solving the Problems) The gist of the present invention for achieving the above object is to provide a combustion air and a vaporized liquid which are introduced into a combustion chamber in the combustion cylinder from an air inflow hole in a peripheral wall of the combustion cylinder. In a combustor of a vehicle combustion heater adapted to ignite and combust an air-fuel mixture in the combustion chamber, a heat insulating cover that covers the entire peripheral wall of the combustion cylinder is provided, and the inner peripheral surface of the heat insulating cover and the An air inflow for introducing the combustion air into the combustion chamber from the air inflow hole is provided at a position corresponding to the air inflow hole in the peripheral wall of the heat insulating cover, with a gap provided between the combustion cylinder and the outer peripheral surface. The present invention relates to a combustor of a combustion heater for a vehicle, which is characterized by having holes formed therein.

(Operation) In the combustor of the vehicle combustion heater, the entire peripheral wall of the combustion cylinder is covered with the heat insulating cover and the gap serves as an air layer for heat insulation, so that the entire combustion chamber is kept warm and external Since the combustion air introduced from the inside is introduced into the combustion chamber through the heat insulating cover and the air inflow hole of the combustion cylinder, the combustion cylinder is not cooled by the combustion air.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view of a vehicular combustion heater to which a combustor according to an embodiment of the present invention is applied. The combustion heater is composed of a combustor 1 and a heat exchanger 2.

The combustor 1 is provided with a combustion tube 4 having a large number of air inflow holes 4a formed in the peripheral wall and having a combustion chamber 3 inside, and a flange 4b formed at one end of the combustion tube 4 has an opening at the center. The combustion tube 4 is fixed to the mounting plate 5, and the other end of the combustion tube 4 is closed by a disc-shaped wick 6 formed of, for example, ceramic fiber.
On the outer end surface of the wick 6, a flange 7b of a passage forming member 7 having a fuel passage 7a for supplying the liquid fuel pumped by a fuel supply pump (not shown) to the wick 6 is attached.

On the outer periphery of the combustion cylinder 4, a heat insulating cover 8 that covers the entire peripheral wall is provided.
Is installed. The heat insulating cover 8 has a cylindrical portion 8a lightly press-fitted on the outer periphery of the combustion cylinder 4 with a slight gap as shown in FIG. 2, and an end wall covering the front end surface of the flange 7b of the passage forming member 7. It consists of a part 8b. The end wall portion 8b
A shaft portion of the passage forming member 7 projects outward from an opening formed in the center of the. An air inflow hole 8c having substantially the same diameter as the air inflow hole 4a is formed at a position corresponding to the air inflow hole 4a of the combustion cylinder 4 on the peripheral wall of the tubular portion 8a of the heat insulating cover 8. In addition, according to the experiment result by the applicant of the present application, the air inflow hole 8c is shown.
Depending on the arrangement of the air inflow holes 4a of the combustion cylinder 4, it may be better to increase or decrease the size up to about 20% to improve the combustion state.

The body cover 9 surrounds the heat insulating cover 8 and the passage forming member 7.
The flange 9a at one end of the body cover 9 is fixed to the mounting plate 5. On the peripheral wall of the body cover 9, there are a mounting hole 9b in which a glow plug 10 is mounted so that an ignition part 10a projects into the combustion chamber 3, and a combustion air inlet 9b.
c is formed and the front end wall of the main body cover 9 has an opening 9 for allowing the shaft of the passage forming member 7 to project to the outside.
d is formed. A sealing member 11 having an opening for allowing the tip of the passage forming member 7 to protrude to the outside is attached to the flange 9e forming the opening 9d. In this way, an air passage 12 is formed between the main body cover 9, the heat insulating cover 8 and the passage forming member 7.

The flange 13a of the connecting pipe 13 is fixed to the end surface of the mounting plate 5 on the side opposite to the combustor, and the heat exchanger 2 is connected to the combustor 1 via the connecting pipe 13.

The heat exchanger 2 has a combustion pipe 21 having one end fitted to the inner circumference of the connection pipe 13, an inner cylinder 22 arranged to cover the outer circumference of the combustion pipe 21, and an outer circumference of the inner cylinder 22. And an outer cylinder 23 disposed in the.

As shown in FIGS. 1 and 3, the combustion pipe 21 forms a combustion gas passage 24, and an end portion of the combustion gas passage 24 is formed between the outer periphery of the combustion pipe 21 and the inner periphery of the inner cylinder 22. The combustion gas passage 25 communicates with one end of the combustion gas passage 25. One end side opening of the inner cylinder 22 is closed by a cover 26, and the other end side opening is closed by the connecting pipe 13 and the spacer 27.
An exhaust port 22a for discharging combustion gas from the other end of the combustion gas passage 25 is formed at the other end of the inner cylinder 22. As shown in FIGS. 3 and 4, a plurality of fins 22b are provided on the inner circumference of the inner cylinder 22 at equal intervals in the circumferential direction so as to connect the inner cylinder 22 and the combustion gas passage 25. It is designed to efficiently exchange heat with the combustion gas passing therethrough.

As shown in FIGS. 1 and 3, on both sides of the outer cylinder 23, a heating air inlet port 23a and a heating air outlet port 23b are provided.
Are formed. The inlet 23a and the outlet 23b are
The inner cylinder 22 and the outer cylinder 23 communicate with each other via a heating air passage 27 formed between the outer circumference and the inner circumference of the outer cylinder 23. As shown in FIG. 3 and FIG. 4, a plurality of fins 22c are provided on the outer periphery of the inner cylinder 22 at equal intervals in the circumferential direction, and the fins 22c are projected from the suction port 23a for heating. The air is efficiently exchanged with the inner cylinder 22, which has become hot due to heat exchange with the combustion gas while the air flows in the heating air passage 27 toward the air outlet 23b. Furthermore, the fin 22c
As shown in FIG. 4, the side surface of the is provided with fine irregularities 22c 'for increasing the surface area.

The operation of the vehicle combustion heater having the above structure will be described below.

When the operating portion (not shown) is turned on to start heating the vehicle interior, the combustion air is supplied from the combustion air inlet 9c into the air passage 12 by the blower (not shown), and the heat insulating cover 8 and the combustion cylinder 3 are heated. Combustion chamber 3 through air inlet holes 8c and 4a
Will be introduced in. On the other hand, the liquid fuel is supplied to the wick 6 from the fuel passage 7a of the passage forming member 7 by a pump (not shown) and is temporarily impregnated in the wick 6. When the glow plug 10 is sparked, the liquid fuel impregnated in the wick 6 is vaporized, and the gas mixture of the vaporized liquid fuel and the combustion air is ignited to start combustion and high-temperature combustion gas is generated. . During the heating, the combustion air constantly flows from the combustion air inlet 9c to the heat insulation cover 8 and the air inlet 8 of the combustion tube 3.
Although it is introduced into the combustion chamber 3 through c and 4a, the entire peripheral wall of the combustion cylinder 4 is covered by the heat insulation cover 8 to retain heat, and the inner peripheral surface of the cylinder portion 8a of the heat insulation cover 8 and the outer periphery of the combustion cylinder 4 The space between the surfaces (see FIG. 2) serves as an air layer for heat insulation, so that the entire combustion chamber 3 is kept warm. Therefore,
The entire periphery of the combustion chamber 3, which becomes high temperature after the combustion of the air-fuel mixture starts, that is, the entire peripheral wall of the combustion tube 4 is not cooled by the combustion air, and a high temperature state for maintaining complete combustion of the air-fuel mixture is maintained.

The high temperature combustion gas generated in the combustion chamber 3 is, as shown by the solid arrow in FIG.
3, after passing through the combustion gas passage 24 and the combustion gas passage 25, it is discharged from the exhaust port 22a of the inner cylinder 22. At this time, the inner cylinder 22 becomes hot due to heat exchange with the combustion gas while the high-temperature combustion gas passes through the combustion gas passage 25. On the other hand, the heating air is drawn in through the heating inlet 23a and flows through the heating air passage 27 toward the heating outlet 23b, as indicated by the broken line in FIG. The heating air is heated in the inner cylinder 2 while passing through the heating air passage 27.
The air for heating is heated by being heat-exchanged with 2, and the heated heating air is blown into the vehicle interior from the heating outlet 23b to heat the vehicle interior.

When the operation unit (not shown) is turned off to stop the heating of the passenger compartment, the supply of the combustion air and the liquid fuel is stopped, and the combustion of the air-fuel mixture remaining in the combustion chamber 3 disappears.
The combustion gas is exhausted and the heating of the passenger compartment is stopped.

In the above embodiment, the cylindrical portion 8a of the heat insulating cover 8 is burned with a slight gap between the inner periphery of the cylindrical portion 8a of the thermal insulating cover 8 and the outer periphery of the combustion cylinder 4 as shown in FIG. Although it was lightly press-fitted to the outer periphery of the cylinder 4, by increasing the gap between the inner periphery of the cylinder 8a and the outer periphery of the combustion cylinder 4 and connecting the air inflow holes 8c and 4a with a connecting pipe, the cylinder 8a A closed air layer for heat insulation may be provided between the inner peripheral surface of and the outer peripheral surface of the combustion tube 4. In this case, due to the air layer that is closed, the combustion cylinder 4 is different from the above embodiment.
This has the advantage that the entire peripheral wall of is less likely to be cooled by the combustion air.

Although the above embodiment is of a type in which liquid fuel is vaporized in the combustion chamber 3, the present invention is also applicable to a combustion type heater of the type in which vaporized liquid fuel is supplied into the combustion chamber 3. . The combustion type heater is configured to supply the liquid fuel vaporized by a vaporization plug disposed in the middle of the liquid fuel supply path into the combustion chamber, for example.

(Effects of the Invention) As described in detail above, according to the combustor of the combustion heater for a vehicle according to the present invention, a heat insulating cover that covers the entire peripheral wall of the combustion cylinder is provided, and the inner peripheral surface of the heat insulating cover and the combustion cylinder. A gap is provided between the combustion chamber and the outer peripheral surface of the heat insulation cover, and the combustion air is introduced from the air inflow hole into the combustion chamber inside the combustion cylinder at a position corresponding to the air inflow hole in the peripheral wall of the combustion cylinder. With the configuration in which the air inlet hole is formed, the entire peripheral wall of the combustion cylinder is covered with the heat insulating cover and the gap serves as an air layer for heat insulation, so that the entire combustion chamber is kept warm and the combustion introduced from the outside is performed. Since the working air is introduced into the combustion chamber through the heat insulating cover and the air inflow hole of the combustion cylinder, the entire circumference of the combustion chamber where the mixture of vaporized liquid fuel and combustion air starts to burn and becomes high temperature, That is, the entire peripheral wall of the combustion tube is exposed to the combustion air. Is not cooled. Therefore, the combustion chamber in the combustion cylinder is maintained at a high temperature and the air-fuel mixture is always completely combusted, soot due to incomplete combustion does not adhere to the inner peripheral wall of the combustion cylinder, and combustion performance and durability can be improved. In addition, because the air-fuel mixture burns completely, the extinguishing time from the stop of the supply of liquid fuel and combustion air into the combustion chamber until the combustion of the air-fuel mixture disappears is shortened, and the emission of blue-white smoke when it disappears The amount can be reduced.

[Brief description of drawings]

1 to 4 show one embodiment of the present invention. FIG. 1 is a vertical sectional view of a combustion heater for a vehicle, and FIG. 2 is an enlarged sectional view of a part of FIG. 3 is a sectional view taken along the line III-III in FIG. 1, and FIG. 4 is an enlarged sectional view of a part of FIG. 1 ... Combustor, 3 ... Combustion chamber, 4 ... Combustion cylinder, 4a ...
Air inflow hole, 8 ... Heat insulation cover, 8c ... Air inflow hole.

Claims (1)

[Scope of utility model registration request] 1. A mixture of combustion air and vaporized liquid fuel introduced into a combustion chamber in the combustion cylinder from an air inlet hole in a peripheral wall of the combustion cylinder is ignited and burned in the combustion chamber. In a combustor of a combustion heater for a vehicle, a heat insulating cover that covers the entire peripheral wall of the combustion cylinder is provided, and a gap is provided between an inner peripheral surface of the heat insulating cover and an outer peripheral surface of the combustion cylinder.
A combustion heater for a vehicle, characterized in that an air inflow hole for introducing the combustion air from the air inflow hole into the combustion chamber is formed in a position corresponding to the air inflow hole on the peripheral wall of the heat insulating cover. Combustor.