JPH0440602B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a pulse combustion device in which combustion of a mixture of air and fuel is intermittently repeated in a combustion chamber.

[Technical background of the invention]

FIG. 1 shows a schematic configuration of the entire pulse combustion apparatus, in which 1 is a combustion chamber, and 2 is a cylindrical mixing chamber disposed upstream of this combustion chamber 1. In FIG. One end of each of an air supply pipe 3 and a fuel supply pipe 4 are connected to the mixing chamber 2. In addition, air supply pipe 3
Air is supplied through an intake muffler 5 and an air valve 7 in an air chamber 6.
Further, fuel gas is supplied to the fuel supply pipe 4 via a cushion tank 8 and a fuel valve 9. The air and fuel gas introduced into the mixing chamber 2 via the air supply pipe 3 and the fuel supply pipe 4 are mixed within this mixing chamber 2,
Explosive combustion occurs within the combustion chamber 1.
In this case, at the time of startup, air is supplied into the air supply pipe 3 by the blower fan 10, and the mixture of air and fuel gas mixed in the mixing chamber 2 is ignited by the igniter 11 and combusted. It is designed to explode and burn inside chamber 1. After starting, the air valve 7 and the fuel valve 9 are intermittently opened and closed to supply air and fuel intermittently, and due to contact with the high temperature residual gas in the combustion chamber 1 and the inner wall, etc. The air-fuel mixture supplied into the combustion chamber 1 is then ignited, and explosive combustion is repeated in a pulsed manner. Further, a tail pipe 12 is connected to the combustion chamber 1. The exhaust gas in the combustion chamber 1 is discharged from the tail pipe 10 to the outside via a decoupler 13, a heat exchanger 14, and an exhaust muffler 15. Note that 16 is a frame rod inserted into the mixing chamber 2.

[Problems in the Background Art] As shown in FIG. The introduced air flow and fuel gas flow meet in a substantially orthogonal state as shown by the arrows in FIG. 2, and are mixed. As a result, the flow of the air-fuel mixture in the mixing chamber 2 is disturbed, and the inflow of the air-fuel mixture from the mixing chamber 2 side to the combustion chamber 1 side is delayed, making it easy for the air-fuel mixture to fill up in the mixing chamber 2. There is no problem in the case of fuel with a relatively slow burning rate, but in the case of a fuel with a relatively fast burning rate such as hydrogen-based fuel, most of the There was a problem with the mixture being burned. In this way, when the air-fuel mixture is combusted in the mixing chamber 2, the surrounding wall surface of the mixing chamber 2 is heated to a high temperature state, and when no cooling means such as water cooling is provided, the surrounding wall surface of the mixing chamber 2 is heated to a high temperature. Since the surrounding wall surface becomes red-hot, the heat radiated from the mixing chamber 2 reduces combustion efficiency, and the heat radiated to the surroundings of the mixing chamber 2 may cause damage to various components installed around the mixing chamber 2 or a fire. There was a risk of an outbreak. Furthermore, since the air sent into the mixing chamber 2 from the air supply pipe 3 hits the peripheral wall surface of the mixing chamber 2 almost perpendicularly, the air inflow resistance becomes large, and the air flows from the air supply pipe 3 side to the mixing chamber 2 side. There was a problem that the supply could not be carried out smoothly. As a result, there was a problem in that the amount of air supplied was insufficient and incomplete combustion was likely to occur due to lack of air, resulting in the generation of harmful carbon monoxide (CO).

[Purpose of the invention]

The present invention provides a pulse combustion device that can prevent a temperature rise on the wall surface of a mixing chamber, and can also smooth the supply of air from an air supply pipe into the mixing chamber, thereby improving combustion characteristics. The purpose is to

[Summary of the invention]

Air supply pipes are connected along the surface plane of the inner wall of the cylindrical mixing chamber, and the mixing direction is opposite to the swirling direction of the vortex formed in the mixing chamber by the air introduced into the mixing chamber from the air supply pipe. The fuel supply pipe is connected in the tangential direction of the indoor wall surface.

[Embodiments of the invention]

FIGS. 3 to 5 show an embodiment of the present invention. In addition, FIG. 3 and FIG. 4 show the main part structure of a pulse combustion apparatus, and 21 is a cylindrical mixing chamber. This mixing chamber 21 has a cylindrical shape with a bottom, and the open end side of this mixing chamber 21 is connected to a combustion chamber 22.
is connected to. Further, an air supply pipe 23 and a fuel supply pipe 2 are provided on the peripheral wall surface on the closed end side of the mixing chamber 21.
4 are connected to each other. In this case, the air supply pipe 23 is connected along the tangential direction of the inner wall surface of the mixing chamber 21.
The air introduced into the mixing chamber 21 swirls along the inner wall surface of the mixing chamber 21 as shown by arrows in FIGS. 3 and 4, and a vortex is formed within the mixing chamber 21. Furthermore, the fuel supply pipe 24 is connected in the tangential direction of the mixing chamber 21, which is opposite to the swirling direction of the vortex formed by the air introduced into the mixing chamber 21 from the air supply pipe 23. Further, an igniter 25 for ignition is attached to the peripheral wall surface of the mixing chamber 21 at the intersection of the center lines of the air supply pipe 23 and the fuel supply pipe 24.

Therefore, in the case of the above structure, at the time of starting, air supplied by the fan 10 (shown in FIG. 1) is introduced into the mixing chamber 21 from the air supply pipe 23, and the air is mixed from the fuel supply pipe 24. Fuel gas is introduced into the chamber 21 . The air thus introduced into the mixing chamber 21 from the air supply pipe 23 turns clockwise in FIG. 3 along the inner wall surface of the mixing chamber 21, and is introduced into the mixing chamber 21 from the fuel supply pipe 24. The fuel gas thus generated swirls counterclockwise in FIG. 3 along the inner wall surface of the mixing chamber 21. Therefore, the air and fuel gas introduced into the mixing chamber 21 come into contact at the intersection of the center lines of the air supply pipe 23 and the fuel supply pipe 24, and are mixed.
An igniter 25 placed at the intersection of the center lines of fuel supply tube 3 and fuel supply pipe 24 reliably ignites the fuel and starts pulse combustion.
Further, after starting, as the air-fuel mixture in the fuel chamber 22 explodes and burns, the air valve 7 and fuel valve 9 shown in FIG. Ru. In this case, after starting, the amount of air introduced into the mixing chamber 21 from the air supply pipe 23 is increased from the fuel supply pipe 24 to the mixing chamber 21.
1, the amount of air introduced into the mixing chamber 21 from the air supply pipe 23 is extremely large compared to the amount of fuel introduced into the mixing chamber 21, as shown by the arrow in FIG. A swirling vortex flow is formed along the inner wall surface. The air is swirled within this mixing chamber 21 and mixed with the fuel gas. The air-fuel mixture sent from the mixing chamber 21 to the combustion chamber 22 side is ignited by contact with the high-temperature residual gas in the combustion chamber 22, the inner wall, etc., and explodes and burns. 22, explosion and combustion of the air-fuel mixture is repeated in a pulsed manner.

Thus, in the above configuration, the air supply pipe 23 is connected along the inner wall connection line direction of the mixing chamber 21, and the air supply pipe 23 is connected to the mixing chamber 21.
The air introduced into the mixing chamber 21 swirls along the inner wall surface of the mixing chamber 21 and a vortex is formed within the mixing chamber 21. During pulse combustion, the air supply pipe 2
The inner wall surface of the mixing chamber 21 can be cooled by the swirling flow formed by the low-temperature air introduced into the mixing chamber 21 from the mixing chamber 3 . Therefore, in the relationship diagram showing the relationship between the combustion amount and the wall temperature of the mixing chamber 21 in FIG. 5, as shown by the solid line, the increase in the wall surface temperature of the mixing chamber 21 is prevented compared to the case of the conventional configuration shown by the dotted line. As a result, combustion efficiency can be improved compared to the conventional method, and damage to various members disposed around the mixing chamber 21 and occurrence of fire can be prevented. Furthermore, since the air introduced into the mixing chamber 21 from the air supply pipe 23 swirls along the inner wall surface of the mixing chamber 21, compared to the conventional case where the air is applied approximately perpendicularly to the inner wall surface of the mixing chamber. This can reduce air inflow resistance and facilitate air supply. Therefore, generation of incomplete fuel due to insufficient air supply can be prevented. Further, the vortex flow of air formed in the mixing chamber 21 can promote mixing of air and fuel gas, and the combustion characteristics can be further improved.

It should be noted that this invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the invention.

〔Effect of the invention〕

An air supply pipe is connected along the tangential direction of the cylindrical inner wall surface of the mixing chamber arranged on the upstream side of the combustion chamber, and the air introduced into the mixing chamber from this air supply pipe is used to generate air inside the mixing chamber. Since the fuel supply pipe is connected in the tangential direction of the wall surface of the mixing chamber, which is opposite to the swirling direction of the vortex flow that is formed, it is possible to prevent the temperature of the wall surface of the mixing chamber from rising, and the supply from the air supply pipe to the mixing chamber is smooth. It is possible to improve the combustion characteristics.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of the entire pulse combustion device, FIG. 2 is a cross-sectional view of main parts showing a conventional example, FIGS. 3 to 5 show an embodiment of the present invention, and FIG.
The figure is a cross-sectional view of the main part, Figure 4 is a longitudinal cross-sectional view of the same, and Figure 5 is a cross-sectional view of the main part.
The figure is a relationship diagram showing the relationship between the combustion amount and the wall surface temperature of the mixing chamber. 21...Mixing chamber, 22...Combustion chamber, 23...Air supply pipe, 24...Fuel supply pipe.

Claims (1)

[Claims] 1 A cylindrical mixing chamber is provided upstream of the combustion chamber, and an air supply pipe and a fuel supply pipe are connected to this mixing chamber, respectively, and air and fuel are supplied through these air supply pipes and fuel supply pipes. In the pulse combustion device in which the air is intermittently introduced into the mixing chamber and mixed, and is intermittently combusted within the combustion chamber, the air supply pipe is connected along a tangential direction of a cylindrical inner wall surface of the mixing chamber. and the fuel supply pipe is connected in a tangential direction of a wall surface of the mixing chamber, which is opposite to a swirling direction of a vortex formed in the mixing chamber by air introduced into the mixing chamber from the air supply pipe. A pulse combustion device featuring: