JPH0512576Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Purpose of the invention] (Industrial field of application) This invention is a method for reducing liquid This invention relates to a pulse combustion device that enables the use of fuel.

(Prior Art) As is well known, a water heater using a pulse combustion device as a heat source has been developed. FIG. 2 shows a schematic configuration of the main parts of this type of water heater, in which 1 is a hot water storage tank of the water heater, and 2 is a pulse combustion device attached to this hot water storage tank 1. Further, 3 is a combustion chamber of the pulse combustion device 2, and 4 is a mixing chamber connected to the upstream side of the combustion chamber 3. In this case, the combustion chamber 3 is arranged inside the hot water storage tank 1 of the water heater, and the mixing chamber 4 is arranged outside the hot water storage tank 1. Further, an air supply pipe 5 and a fuel supply pipe 6 are connected to the mixing chamber 4, respectively. An air flapper valve 7 and a fuel flapper valve 8 are interposed in the air supply pipe 5 and fuel supply pipe 6, respectively, to open and close as the pressure inside the combustion chamber 3 changes. And air flapper valve 7
Air is intermittently supplied into the mixing chamber 4 through the air supply pipe 5 as the flapper valve 8 opens and closes, and air is intermittently supplied into the mixing chamber 4 through the fuel supply pipe 6 as the flapper valve 8 opens and closes. The mixed fuel is mixed in the mixing chamber 4, and this air-fuel mixture is explosively burned in a pulsed manner in the combustion chamber 3. Further, a tail pipe 9 is connected to the combustion chamber 3. This tail pipe 9 is connected to the combustion chamber 3 as well as the hot water storage tank 1 of the water heater.
It is placed inside the . Then, the combustion gas in the combustion chamber 3 is led out to the outside via the tail pipe 9, and the combustion chamber 3 and the tail pipe 9 are heated to a high temperature state by this combustion gas.
The water in the hot water storage tank 1 is heated by the heat.

By the way, when the pulse combustion device 2 is used as a heat source for a water heater, a mixing chamber 4 for air and fuel is provided upstream of the combustion chamber 3 of the pulse combustion device 2.
By connecting the combustion chamber 3 inside the hot water storage tank 1 of the water heater and the mixing chamber 4 outside the hot water storage tank 1, for example, the air supply pipe 5 and the fuel supply pipe 6, etc. The system facilitates maintenance and inspection work such as installing various piping and replacing fuel injection nozzles. However, in the case of the above-mentioned conventional configuration, the wall temperature of the mixing chamber 4 is heated to about 400°C during the operation of the pulse combustion device 2, so a part of the combustion heat is transferred to the hot water storage tank through the mixing chamber 4. There is a problem of leakage to the outside of 1.
Therefore, there is a problem in trying to improve the thermal efficiency of the water heater, and the surroundings of the mixing chamber 4 are also heated to a high temperature due to heat radiation from the mixing chamber 4. It was necessary to install a heat insulating material 10 etc. around the area, which caused the problem of high cost.

Furthermore, gas fuel is often used as the fuel for the pulse combustion device 2;
As shown in Japanese Patent No. 109666, a pulse combustion device using liquid fuel as fuel has also been proposed. However, in this case, the vaporization mechanism section that vaporizes the liquid fuel is configured to come into contact with a heat exchange section disposed inside the hot water storage tank 1, such as the combustion section or tail pipe section of a pulse combustion device. Therefore, when this technology is applied to the pulse combustion device 2 with the above configuration in which the mixing chamber 4 is connected to the upstream side of the combustion chamber 3, the combustion chamber 4 is connected to the upstream side of the combustion chamber 3. There is a problem that a part of the combustion heat leaks to the outside of the hot water storage tank 1.

(Problems to be solved by the invention) This invention enables the use of liquid fuel without complicating the configuration, reducing thermal efficiency, reducing safety, or making maintenance inspection difficult. The object is to provide a pulse combustion device suitable for use as a heat source for a water heater, for example.

[Structure of the invention] (Means for solving the problem) In order to achieve the above object, the pulse combustion device according to the invention includes a combustion chamber arranged in a tank containing a fluid to be heated, and one end of which is disposed in a tank. a tail pipe connected to the downstream side of the combustion chamber and whose other end is led to the outside of the tank via the inside of the tank; and a mixing pipe located outside the tank and connected to the upstream side of the combustion chamber. a vaporization chamber provided adjacent to the outside of the mixing chamber; a liquid fuel supply mechanism for supplying liquid fuel into the vaporization chamber; and a liquid fuel supply mechanism for supplying liquid fuel into the vaporization chamber; A vaporized fuel supply pipe that supplies air to the mixing chamber; an air supply pipe that supplies air to the mixing chamber; and a pair of valves for feeding the fuel gas and the air into the mixing chamber.

(Operation) When pulse combustion is performed, the walls of the mixing chamber are heated by this combustion heat. Since the vaporization chamber is arranged adjacent to the outside of the mixing chamber, the liquid fuel supplied to the vaporization chamber is vaporized by the heat transmitted through the walls of the mixing chamber, and the liquid fuel produced by this vaporization is The combustion gas is then supplied to the mixing chamber via the valve.

Therefore, the heat transmitted to the walls of the mixing chamber can be effectively used to vaporize the liquid fuel. In addition, although the outer surface of the wall that constitutes the vaporization chamber is located outside the tank, as mentioned above, the heat transferred from the mixing chamber is used to vaporize the liquid fuel, so the outer surface of the wall that constitutes the vaporization chamber becomes high temperature. After all, the vaporization chamber also serves as a thermal insulator between the mixing chamber and the outside.

Further, since the mixing chamber and the vaporization chamber are located outside the tank, maintenance and inspection of the air supply pipe, fuel gas supply pipe, etc. is not obstructed.

(Example) An example of this invention will be described below with reference to FIG. Figure 1 shows a schematic configuration of the main parts of a pulse combustion device used as a heating source for a water heater, etc. as shown in Figure 2, where 11 is a combustion chamber of the pulse combustion device, and 12 is a combustion chamber of this combustion chamber 11. This is a mixing chamber connected to the upstream side. A liquid fuel vaporizer 13 is disposed around the mixing chamber 12. In this case, the mixing chamber 12 is a cylindrical mixing chamber component 1 with a bottom.
It is formed inside 4. The wall of this mixing chamber component 14 has a double structure, and the mixing chamber 12
A hollow carburetor forming space 15 is formed within the peripheral wall of the carburetor. The vaporizer forming space 15 of the mixing chamber forming member 14 forms a vaporizer 13 that heats the liquid fuel with the heat of the mixing chamber 12 during pulse combustion and vaporizes the liquid fuel.

In addition, the vaporizer configuration space 1 of the mixing chamber configuration member 14
5 is connected to a liquid fuel supply pipe 16. A liquid pump 17 is interposed in this liquid fuel supply pipe 16 . And these liquid fuel supply pipes 1
A liquid fuel supply mechanism 18 for supplying liquid fuel to the vaporizer 13 is formed by the fuel pump 6 and the liquid feed pump 17.

Furthermore, one end of a vaporized fuel supply pipe 19 disposed outside the mixing chamber component 14 is connected to the carburetor component space 15 of the mixing chamber component 14 . The other end of this vaporized fuel supply pipe 19 is connected to the mixing chamber component 1
4 and connected to the inside of the mixing chamber 12. Further, a fuel flapper valve 20 is interposed in the vaporized fuel supply pipe 19. The vaporized fuel supply pipe 19 and the fuel flapper valve 20
As a result, a vaporized fuel introduction section 21 for introducing the fuel vaporized by the vaporizer 13 into the mixing chamber 12 is formed. Further, one end of a fuel return pipe 22 is connected to the fuel flapper valve 20. The other end of this fuel return pipe 22 is connected to the carburetor forming space 15 of the mixing chamber forming member 14. The fuel condensed within the fuel flapper valve 20 is returned to the carburetor forming space 15 of the mixing chamber forming member 14 via this fuel return pipe 22.

Further, 23 is an air supply pipe. This air supply pipe 23 penetrates the wall of the mixing chamber component 14 and is connected to the inside of the mixing chamber 12 . Furthermore, an air flapper valve 24 is interposed in the air supply pipe 23. Further, an igniter 25 for ignition at the time of starting is installed in the mixing chamber 12.

Furthermore, an electric heater 26 for starting is embedded in the wall of the mixing chamber component 14. The electric heater 26 is energized only when the wall of the mixing chamber component 14 is maintained at a low temperature, such as during startup, and the heat of pulse combustion is used to energize the mixing chamber component 14.
4 is heated to a high temperature, the electric heater 26 is de-energized. Note that 27 is a heat insulating material attached around the vaporized fuel supply pipe 19 and the fuel flapper valve 20 which are arranged outside the mixing chamber component 14. This is to prevent the vaporized fuel from condensing within the fuel tank 20.

Next, the operation of the above configuration will be explained. First, during pulse combustion, liquid fuel is supplied to the vaporizer 13 via the liquid fuel supply pipe 16 as the liquid feed pump 17 is driven. In this case, when starting the pulse combustion device, the electric heater 2 of the mixing chamber component 14
6 is energized, and the liquid fuel in the vaporizer 13 is vaporized by this electric heater 26. The fuel vaporized in the vaporizer 13 is then transferred to a vaporized fuel supply pipe 19.
from the mixing chamber 12 via the fuel flapper valve 20
be introduced within. Furthermore, air is introduced into the mixing chamber 12 from an air supply pipe 23 via an air flapper valve 24, and the vaporized fuel and air are mixed in the mixing chamber 12, and this mixture is sent to an igniter for ignition at the time of starting. 25 to cause explosive combustion within the combustion chamber 11, thereby starting pulse combustion. Further, after the start of pulse combustion, the electric heater 26 is de-energized in a state where the wall portion of the mixing chamber component 14 is heated to a temperature that evaporates the liquid fuel due to the heat of the pulse combustion. And electric heater 2
After energization is stopped in step 6, the liquid fuel in the vaporizer 13 is vaporized by heat conducted from the mixing chamber 12 through the wall of the mixing chamber component 14.

In this way, in the case of the above configuration, during pulse combustion, the vaporizer 13 around the mixing chamber 12 is heated by the heat of the mixing chamber 12, and the liquid fuel supply pipe is heated by the heat of the mixing chamber 12. Since the liquid fuel introduced into the vaporizer 13 from the vaporizer 16 is vaporized, and the fuel vaporized by the vaporizer 13 is introduced into the mixing chamber 12 via the vaporized fuel supply pipe 19, the pulse During operation of the combustion device, the mixing chamber 12
The combustion heat leaking to the outside through the vaporizer 13 can be effectively used to vaporize the liquid fuel in the vaporizer 13. Therefore, even when a pulse combustion device is used as a heat source for a water heater, the amount of combustion heat leaking to the outside via the mixing chamber component 14 during operation of the pulse combustion device can be reduced compared to the conventional method. As a result, thermal efficiency can be improved. Furthermore, as the amount of combustion heat leaking from the mixing chamber component 14 to the outside is reduced, it is possible to eliminate the risk of the surroundings of the mixing chamber component 14 being heated to a high temperature state, which prevents fires, etc. It is not necessary to install a heat insulating material or the like around the mixing chamber component 14 to prevent danger, and costs can be reduced. Further, since the mixing chamber 12 and the vaporizer 13 are located outside the hot water storage tank, maintenance and inspection of the air supply pipe 23, the liquid fuel supply pipe 16, etc. are not obstructed.

Note that this invention is not limited to the above embodiments. For example, in the above embodiment, the fuel flapper valve 20 is provided in the vaporization combustion supply pipe 19, and the air flapper valve 24 is provided in the air supply pipe 23, but instead of these flapper valves 20 and 24, an aero A configuration may also be adopted in which a dynamic valve is installed. moreover,
Of course, various other modifications can be made without departing from the gist of the invention.

[Effects of the invention] According to this invention, a liquid fuel vaporizer is disposed around a mixing chamber placed outside the tank on the upstream side of the combustion chamber, and the liquid fuel is supplied to the vaporizer. Since a supply mechanism and a vaporized fuel introduction section for introducing the fuel vaporized by the vaporizer into the mixing chamber are provided, the heat that attempts to escape from the mixing chamber to the outside during operation is effectively used to transfer the fuel to the liquid. In addition to being able to vaporize the fuel, the vaporizer can also perform the function of thermally insulating between the mixing chamber and the outside, thereby ensuring safety. Additionally, since the mixing chamber and vaporization chamber are located outside the tank, maintenance and inspection of the air supply pipes, fuel gas supply pipes, etc. can be facilitated, which ultimately reduces the complexity of the configuration and reduces thermal efficiency. It is possible to use liquid fuel without causing deterioration, deterioration of safety, or difficulty in maintenance and inspection.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing a schematic configuration of the main parts of a pulse combustion device according to an embodiment of this invention, and Fig. 2 is a longitudinal cross-sectional view of the main parts showing a conventional pulse combustion device installed in a water heater. be. DESCRIPTION OF SYMBOLS 11... Combustion chamber, 12... Mixing chamber, 13... Carburizer, 18... Liquid fuel supply mechanism, 21... Vaporized fuel introduction part.

Claims (1)

[Claims for Utility Model Registration] (1) A combustion chamber arranged in a tank containing a fluid to be heated, one end of which is connected to the downstream side of the combustion chamber, and the other end of which is connected through the tank. a tail pipe led to the outside of the tank; a mixing chamber arranged outside the tank and connected to the upstream side of the combustion chamber; a vaporization chamber provided adjacent to the outside of the mixing chamber; a liquid fuel supply mechanism that supplies liquid fuel into a room; a vaporized fuel supply pipe that supplies fuel gas generated by vaporization in the vaporization chamber to the mixing chamber; and an air supply that supplies air to the mixing chamber. and a pair of valves provided in the middle of the air supply pipe and the vaporized fuel supply pipe, respectively, for feeding the fuel gas and the air into the mixing chamber in response to pressure fluctuations in the mixing chamber. A pulse combustion device characterized by: (2) The pulse combustion device according to claim 1, which is a registered utility model, characterized in that an electric heater that is energized at startup is attached to the wall of the vaporization chamber.