JPH04116308A - Combustion device of stirling engine - Google Patents

Abstract

PURPOSE:To make the temperature of a heater uniform by concentrically by providing a group of fuel pipes at a position close to the inner face of a combustion drum. CONSTITUTION:The combustion air sent by an external air fan is preheated at an air preheating element 3, passes over a combustion device liner 4, and is sent into an air buffer 9 after passing through between fuel pipes 7 by a flow guide plate 12 as shown by arrows 'a'. The air sent to the air buffer 9 flows outside the group of fuel pipes through between the fuel pipes 7. On the other hand, fuel is sent from a fuel pipe into a fuel buffer 10 through a connecting port 11, distributed to the fuel pipes 7, spouted from a lot of fuel spouting holes 8 provided on the fuel pipes 7, mixed with the combustion air, spouted from burner ports 6 and burnt. (the fuel flow is shown by arrows 'f') The combustion flames 14 horizontally, radially stretch and strike perpendicularly against a heater 1. Since the burner ports 6 are uniformly arranged in the longitudinal and circumferential directions and the flames strike across the whole length of the heater 1, the temperature of the heater 1 can be kept uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a combustor for heating the working fluid of a Stirling engine.

(Prior art) In a Stirling engine, the working fluid flows through a heater provided in a part of the closed circuit and is heated by the combustor. This is extremely important for improving output and efficiency.

Currently, in many Stirling engines, the heater is installed vertically across the cylindrical surface, and the combustor is provided at the upper center of the heater group.

In the conventional Stirling engine combustor, the fuel injection nozzle was installed at the top of the cylindrical combustion tube, so the flame ejected from the lower opening of the combustion tube heated the lower side of the heater more. The second part had the disadvantage that it was not exposed to flame and the temperature was uneven.

Japanese Patent Publication No. 62-20373 discloses that a swirler is installed around the fuel injection nozzle to supply combustion air in the tangential direction of the circumference surrounding the fuel injection nozzle. A combustor for a Stirling engine is disclosed in which the mixed gas is strongly mixed with fuel injected from an injection nozzle, and this mixed gas is primarily combusted in a combustion cylinder, and then completely combusted in a main combustion chamber with a Calorie heater. In this case as well, the shape of the flame in the combustion tube is downward and widens at the bottom, so although complete combustion occurs in the main combustion chamber, the flame does not hit the top of the heater. The temperature will be lower than at the bottom. or,
Swirlers have the disadvantage of causing a large pressure loss in the air system and increasing the driving force of the cooking air blower.

Utility Model Application Publication No. 111828 discloses that a generally cylindrical main body is provided in a closed combustion space, and a first gas flow path that communicates with the combustion space from the outside and a cylindrical wall of the main body from the outside is provided. a second gas flow path leading to the combustion space through a plurality of gas blow holes formed on the outer periphery; and an exhaust path leading to the outside through the center of the main body; A burner is disclosed in which one of the gases flows into a combustion space through a first gas flow path and the other gas flows into a combustion space through a second gas flow path and is combusted. Since the combustion is carried out in a distributed manner on the outside of the main body, it is said that it is possible to heat the heater, etc. uniformly and efficiently. However, in the Go method, combustion is carried out locally in a dispersed manner, so it is not possible to heat the heater uniformly. In order to do this, highly accurate calculations are required, and the structure becomes complicated, resulting in an unavoidable increase in cost.

In addition, Japanese Patent Application Laid-Open No. 5L-79334 discloses that a combustor having a plurality of small holes on the side surface of a cylindrical combustion cylinder is installed inside a group of heat generators, and combustion scum is injected from the small holes. A combustor is disclosed in which the heater is heated by convection heating, but since this combustion tube is placed directly inside the flame,
The drawback is that it gets very hot and is not durable.

(Problems to be Solved by the Invention) In view of the above-mentioned drawbacks of conventionally implemented or proposed star link engine combustors, the present invention has a simple configuration, excellent durability, and It is an object of the present invention to provide a combustor that can evenly apply flame from top to bottom and make the temperature of the heater uniform.

(Means for Solving the Problems) In order to solve the above problems, the combustor for a starlink engine according to the present invention has a large number of combustion holes arranged on a plurality of vertical lines provided at equal intervals in the circumferential direction. A cylindrical combustion tube having a closed lower end on a cylindrical side surface, and a plurality of fuel tubes each having a combustion injection hole at a position opposite to each combustion hole and facing each row in the vertical direction of the combustion tube. It is characterized by having a group of fuel pipes concentrically provided close to the inner surface of the combustion cylinder.

(Function) Since the combustor of the present invention is constructed as described above, the flame does not go downwards in the combustion tube, but extends horizontally and radially from the combustion hole provided on the side surface of the combustion tube. The flame can be applied evenly to both the top and bottom. As a result, the temperature distribution of the heater becomes uniform, improving the output and efficiency of the engine. Furthermore, by designing the diameters of the combustion holes and fuel injection holes to appropriate values, the air ratio can be made constant at any location.

Additionally, since the flame is located outside the combustion hole, the flame does not directly hit the combustion tube, improving durability.

(Example) Below, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a sectional view showing a combustor of a Stirling engine according to an embodiment of the present invention together with a heater and the like.

The working fluid heaters 1 of a Stirling engine are arranged on two cylindrical surfaces and extend in the vertical direction. On the outside thereof, a cylindrical air preheater 2 is provided concentrically with the heater group. An air preheating element 3 is housed inside the air preheater 2 . A combustor liner 4 is attached to the vessel preheating element 3, thereby holding the combustor cylinder 5 centrally inside the heater group 1.

The combustion tube 5 is a cylinder whose lower end is closed and whose upper end is open, and a large number of combustion holes 6 are bored in the side surface along a plurality of vertical lines provided at equal intervals in the circumferential direction of the combustion tube. Combustion tube 5
A plurality of combustion tubes 7 are vertically extended adjacent to the inside of the combustion tube 5, facing the rows of combustion holes 6 of the combustion tube 5. These fuel pipes 7 are arranged on the cylindrical surface of the cylinder 5 and the center of the cylinder, and each fuel pipe 7 is provided with a fuel injection hole 8 at a position opposite to the combustion hole 6 of the combustion cylinder 5. There is. The diameter of the fuel injection hole 8 is much smaller than the diameter of the combustion hole 6 (as shown in FIG.
Either two fuel injection holes 8 are provided with the same center as the combustion hole 6, or
As shown in FIG. 4, a plurality of fuel injection holes may be provided symmetrically with respect to the center of the combustion hole 6 for one combustion hole.

The lower end of the fuel pipe 7 is closed, and the -1 end communicates with a fuel buffer 10 connected to the fuel pipe through a connection port 11.

Further, the salt 1'EI pipe 7 is attached to the combustor liner 4 via a flow control plate 12. The inside of the combustion tube 5 is an air hole 9. Further, an ignition plaque 13 is attached to the combustor liner 4.

Combustion air sent by an external blower is preheated in the air preheating tube l-3, passes through the upper part of the combustor liner 4, and is directed by the flow control plate 12 into the fuel pipe 7 as shown by arrow a in FIG. The air is sent to the air buffer 9 through the air gap.

The air sent to the air buffer 9 passes between the fuel pipes 7 and flows out of the fuel pipe group as shown in FIG. 3 or 4. The above-described flow of combustion air is shown by arrow a in FIGS. 1 to 4.

On the other hand, the fuel buffer 10 is connected from the fuel pipe through the connection port 11.
The fuel sent is distributed to each fuel pipe 7, injected from a large number of fuel injection holes 8 bored in the fuel pipe 7, mixed with the combustion air, jetted from the combustion hole 6, and combusted. do. The above fuel flow is shown by arrow f in FIGS. 1, 3, and 4.

The burned flame 14 extends horizontally and radially and impinges on the heater 1 at right angles. Therefore, by arranging the combustion holes 6 evenly in the vertical and circumferential directions, the flame is applied uniformly over the entire length of the heater 1, and the temperature of the heater can be made uniform.

As shown in FIG. 4, if two or more fuel injection holes 8 are provided for each combustion hole 6, the mixture of fuel and combustion air will be improved.

Furthermore, as shown in FIG. 5, by providing spiral fins 15 on the inner surface of the combustion hole 6, the flow of fuel and air can be swirled to improve mixing.

(Effects) As described below, according to the present invention, with a simple configuration, the flame is uniformly applied over the entire length of the heater, the temperature distribution of the heater is made uniform, and the output and efficiency of the engine are improved. can be done. Furthermore, since the flame is located outside the combustion hole, the flame does not directly hit the combustion tube, which is effective in improving durability.

[Brief explanation of the drawing]

1 is a sectional view showing the structure near the combustor of a Stirling engine according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a sectional view taken along line B in FIG. 4 is a sectional view taken along line -B, FIG. 4 is a sectional view corresponding to FIG. 3 of another embodiment of the present invention, and FIG. 5 is a sectional view of a combustion hole of still another embodiment. 1... Heater, 2... Air preheater, 5... Combustion tube, ■... Fuel pipe, 14... Flame,

Claims (3)

[Claims] (1) Inside the group of heaters to heat a plurality of vertically extending heaters for heating the working fluid of the Stirling engine and an air preheater provided in a cylindrical shape outside of these heaters. The combustor is a cylindrical cylinder with a closed bottom end, which has a large number of combustion holes arranged on a plurality of vertical lines arranged at equal intervals in the circumferential direction on the cylindrical surface. The fuel tube is composed of a shaped combustion tube, and a plurality of fuel tubes each facing each row of the combustion holes in the vertical direction and having a fuel injection hole at a position opposite to each combustion hole, and adjacent to the inside of the combustion tube. A combustor characterized by having a group of fuel pipes arranged concentrically. (2) The combustor according to claim 1, wherein a plurality of fuel injection holes are provided in the fuel pipe for each combustion hole in the combustion tube. (3) The combustor according to claim 1, wherein a spiral fin is provided on the inner surface of the combustion hole.