JPH04116254A - Combustor for stirling engine - Google Patents

Abstract

PURPOSE:To obtain the uniform combustion in a combustion chamber and improve the flame stabilizing property by arranging multiple flame stabilizing rods for unifying the combustion gas at a uniform interval intrusively into the air-fuel mixture. CONSTITUTION:A fuel nozzle 3 injecting the fuel is provided at the center section of the top wall 2 of the combustor for a Stirling internal combustion engine 1, and a swirler 7 guiding the preheated combustion air into a burner tile 4 via an air preheater 6 is provided at the upper section of the burner tile 4. An igniter 8 is arranged intrusively into the air-fuel mixture in the primary combustion space 5 from the top wall 2, an ignition transformer 9 is connected to the igniter 8, a spark is generated by the igniter 8 to cause ignition in the air-fuel mixture. Multiple flame stabilizing rods 12 with the same diameter and same length as those of the igniter 8 and a flame rod 10 are intruded into the air-fuel mixture in the primary combustion space 5 from the top wall 2, and the igniter 8, flame rod 10 and flame stabilizing rods 12 are uniformly arranged on the same circumference.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a combustor for a Stirling engine.

[Prior art]

Conventionally, as shown in FIG. 3, a fuel spray nozzle 51 for spraying fuel, a swirler 52 for introducing combustion air arranged around the nozzle, and fuel from the nozzle 51 and combustion air from the swirler 52 are used. A cylindrical burner cone 53 for primary combustion of the air-fuel mixture of The swirler 52 supplies combustion air tangentially into the burner cone 53, and the opening facing the combustion chamber 55 is arranged in a radial direction. For example, a Stirling engine combustor having an igniter at the combustion air outlet of the swirler 52 for ignition is disclosed in Japanese Patent Laid-Open No. 62
It is publicly known from the publication No.-20373.

The combustor mentioned above is used as a combustor for an external combustion engine.

In conventional combustors for Stirling engines, the aim is to achieve stable combustion and almost uniform temperature distribution by swirling the combustion air inside the burner cone in a spiral pattern, but the following problems arise: produce.

(2) Since the Eve Knife is inserted into the swirled air-fuel mixture, turbulence occurs in the swirling flow, causing turbulence in the flame after ignition, that is, local slits in the flame. As a result, combustion is not necessarily uniform within the combustion chamber, and some parts tend to reach higher temperatures than necessary, leading to early burnout of parts within the combustion chamber and uneven temperature of the working gas, which reduces the durability of the Stirling engine. This resulted in a decrease in output.

2. Due to the turbulence of the swirling flow caused by the Eve Knife, the purpose of the conventional technology of maintaining stable combustion by swirling the combustion air was lost, resulting in an unstable flame and reduced flame stability. This caused problems with the operation of the Stirling engine.

The burner has heater tubes, which are part of a high-temperature heater, arranged in its combustion chamber, and uses combustion heat to heat the working gas in the closed circuit through the heater tubes, so combustion occurs within the combustion chamber. It is required to be applied uniformly and to have stable flame stability. However, in some conventional combustors, combustion was not performed uniformly and flame stability was poor due to the Eve knife and flame rod inserted directly into the combustion chamber.

[Industrial application field]

The second object of the present invention is to provide a combustor for a Stirling engine that solves the problems of the conventional combustor for a Stirling engine and enables uniform combustion within the combustion chamber and improved flame stability.

[Means to solve the problem]

The present invention includes a fuel injection nozzle that injects fuel, a swirler for introducing air arranged around the nozzle, and a primary combustion of a mixture of the fuel from the nozzle and the air from the swirler. A combustor for a Stirling engine having a burner tile for igniting the mixture and an oil knife for igniting the mixture, wherein a plurality of flame holding rods for homogenizing combustion gas are arranged so as to protrude into the mixture, The problem was solved by a combustor for a Stirling engine characterized in that the flame stabilizing rods are arranged at equal intervals.

[Function] According to the present invention, the flame stabilizing rods are arranged equally on the same circumference as the Eve knife and the flame rod. Only the Eve knife and flame rod are inserted directly into the combustion chamber, which causes cracks in the flame, but by inserting a flame-holding rod, it is possible to prevent flame cracks to a minimum and ensure uniform combustion. do. In addition, by inserting the flame stabilizing rod directly into the combustion chamber, the flame stabilizing rod itself is heated and functions similarly to a pilot burner, and a circulating vortex is generated in the wake of the flame stabilizing rod, causing high temperature combustion gas to flow out. Being caught up in this vortex stabilizes the flame and improves flame stability.

〔Example] The details of the present invention will be explained based on embodiments shown in the drawings.

In FIG. 1, a combustor 1 for a Stirling internal combustion engine has a fuel nozzle 3 for injecting fuel in the center of a top wall 2, and the outlet of the fuel nozzle 3 is located inside a hollow burner tile 4 made of heat-resistant steel. That is, it enters into the primary combustion space 5 formed inside the hollow burner tile 4. The upper part of the burner tile 4 has a swirler 7 that introduces combustion air preheated through the air preheater 6 into the inside of the burner tile 4.

The swirler 7 spirally introduces combustion air into the burner tile 4 in a tangential direction thereof, thereby effectively promoting mixing with the fuel injected from the fuel nozzle 3. - An eve knife 8 is arranged so as to protrude from the top wall 2 into the air-fuel mixture in the fire combustion space 5, and an ignition transformer 9 is attached to the eve knife 8.
is connected, and the Eve knife 8 generates a spark to ignite the air-fuel mixture. Eve knife 4
Similarly, flame detection is performed by a flame detection device 11 connected to a lower flame rod 10 that plunges from the top wall 2 into the air-fuel mixture in the primary combustion space 5 and to the flame rod 10. A plurality of flame stabilizing rods 12 (four in the figure), which are formed to have the same diameter and the same length as the Eve knife 8 and the flame rod 10, protrude from the top wall 2 into the air-fuel mixture in the primary combustion space 5. As shown in FIG. 2, the Eve knife 8, the flame rod 10, and the flame holding rod 12 are arranged equally on the same circumference (in this embodiment, at 60° intervals). The igniter 8, flame rod 10, and flame stabilizer 12 are all directly inserted into the fire combustion space 5. The flame stabilizer 12 has the function of making the combustion gas ejected from the outlet of the burner tile 4 into the secondary combustion space 15 uniform.

The heater tube 14 of the high temperature heat exchanger 13 is arranged around the secondary combustion space 15 . The flame stabilizer 12 is effective in heating the working gas in the heater tube 14 to an isothermal temperature, and can be a factor in improving the output and efficiency of the Stirling engine. Since the air-fuel mixture is combusted uniformly within the combustion chamber, there is no need for any part of the engine to become hotter than necessary, which prevents premature burnout of parts within the combustion chamber and improves the durability of the Stirling engine. It becomes a factor that causes Furthermore, since the flame stabilizer 12 is inserted directly into the primary combustion space 5, the flame stabilizer 12 itself is heated to a high temperature and becomes a flame stabilizer, improving flame stability.

Note that the flame stabilizer 12 is made of heat-resistant steel. Since the combustion in the primary combustion space 5, which is the insertion space, is in the initial state, the flame temperature has not risen, and there is no problem with the heat resistance of the flame stabilizer 12.

〔effect〕

According to the present invention, a plurality of flame stabilizers are directly inserted into the flame combustion space, which can keep the combustion uniform, make the temperature distribution of the working gas uniform, and improve the output efficiency of the Stirling engine. Furthermore, since the flame stabilizer itself can act as a flame stabilizer, flame stabilization performance is improved, and operation can be performed without causing any trouble to the Stirling engine.

[Brief explanation of drawings]

The first is a cross-sectional view of a combustor for a Stirling engine according to an example of the present invention, FIG. 2 is a view taken along the arrow at the point indicated by A in FIG. 1, and FIG. It is.

Claims (1)

[Claims] A fuel injection nozzle that injects fuel, a swirler for introducing air arranged around the nozzle, and a burner tile that primarily burns a mixture of fuel from the nozzle and air from the swirler. and an igniter for igniting the air-fuel mixture, wherein a plurality of flame-holding rods for homogenizing combustion gas are arranged to protrude into the air-fuel mixture, A combustor for a Stirling engine characterized by rods arranged at equal intervals.