JPS6179851A - Stirling engine combustor - Google Patents

Abstract

PURPOSE:To improve heat insulating efficiency and nozzle cooling efficiency by constructing a cover body which covers the top of a combustor body, with a cover in which a heat reflecting board is embedded in a heat insulating material, and a second cover which is provided apart from, and opposite to, said cover, and providing a fuel injection nozzle passing through both of the covers. CONSTITUTION:In the captioned combustor, a combustion chamber 2, etc. is provided in a combustor body and a cover body 9 which has a fuel injection nozzle 8 in its center, is fixed to its upper part, while a preheating air chamber 12 is formed between a upper partition board 11 having a swirler 10 and the cover body 9. In this case, the cover body 9 consists of a first and a second covers 13, 19. The first cover 13 is formed by providing a heat insulating material 16 between a pair of reflecting boards 14, 15, and embedding a reflecting board 17 in the heat insulating board 16. The second cover 19 is provided apart from the cover 13, and a bracket 21 which forms a vacant space 20 into which a cooling air is fed through a pipe 24, is provided on the top wall in the center of the second cover 19, and the fuel injection nozzle 8 is provided in a pipe 23 which passes through these covers 13, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a combustor for a Stirling engine.
It is also used to minimize waste heat through the fuel injection nozzle.

(Prior art and its problems) As shown in FIG. 3, a conventional combustor 1 for a Stirling engine has a combustion chamber 2, a heater tube 3, and a combustion air preheating tube 4 inside, and its outer peripheral wall A lid body 9' having a heat insulating material made of an asbestos-based solid component and having a fuel injection nozzle 8 in the center is fixed to a water body 7 having an air intake duct 5 and a combustion gas discharge duct 6, and The structure is such that a preheated air chamber 12 is formed between a fixed upper partition plate 11 having a swirler 10 and a lid 9'.

In FIG. 3, the combustion air entering from the direction indicated by the arrow enters the preheating tube 4 below the main body T, receives the heat of the exhaust gas in the combustion chamber 2, is preheated, and is sent to the preheating air 812. Next, the preheated combustion air is mixed with fuel from the nozzle 8 and supplied into the combustion chamber 2 via the swirler 10 . On the other hand, the exhaust gas passes through the preheating tube 4 and is discharged to the outside from the discharge duct 6.

In such a conventional combustor 1, combustion heat is transmitted through the upper partition plate 1.
1 to the air in the preheated air chamber 12 to heat it, but a considerable amount of heat is radiated to the outside via the lid 9'. This can be easily understood from the fact that the temperature of the outer surface of the lid 9' rises to nearly 200°C.

This heat dissipation loss corresponds to a loss of approximately 5 inches of supplied heat.

Furthermore, when the lid body 9' reaches such a high temperature, a considerable thermal stress is applied to the lid body 9', which damages the asbestos-based insulation material and causes pieces of the insulation material to swirl. -10 and preheating pipe 4, clogging the swath 2-10 and preheating pipe 4'fr, obstructing the flow of combustion air and reducing combustion efficiency.

Furthermore, the heat leaking to the outside through the fuel spray nozzle 8 also becomes a considerable heat loss.

(Problems and technical means of the present invention) The present invention aims to eliminate the above-mentioned problems, and in order to achieve the purpose, the lid body covering the opening of the combustor main body is provided with a heat reflecting plate as a heat insulating material. It has a laminated heat insulation structure consisting of an embedded first cover and a second cover facing away from the first cover, and the space inside the bracket provided on the second cover and the preheated air chamber are connected through a A technical means is used in which the fuel mist nozzle held on the bracket is extended toward the center of the swirler through the nozzle.

The adoption of the above means allows the space between the first and second covers to have a heat insulating effect and reduce heat loss to the outside, and the air flowing into the preheating air chamber from inside the bracket to cool the fuel spray nozzle. At the same time, it prevents the bracket from rising in temperature.

(Example) Please refer to FIGS. 1 and 2. The combustor main body 7 in the example shown in the same figure is substantially the same as that in FIG. 3, so a description thereof will be omitted and the same reference numerals will be used.

The lid body 9 has a first cover 13 that forms a preheating air chamber 12 communicating with the combustion air preheating pipe 4 between the lid body 9 and the liner 11 which is separated by a partition plate. The first cover 13 has a pair of reflective plates 14 .
, 15 has a heat insulating material 16 within the heat insulating material 16, and has a structure in which a reflecting plate 17 is embedded within the heat insulating material 16. The lid body 9 further includes a second cover 19 that faces the first cover 13 at a distance and creates a space 18 therebetween. This space 18 acts as a heat insulating layer and prevents combustion heat from being released to the outside. prevent.

The fuel spray nozzle 8 and the igniter 22, which are provided on the central top wall of the second cover 19 and are held by a bracket 21 having a space 20 therein, are passed through the lid body 9 and directed toward the central part of the swirler 10. extend to. The nozzle 8
A nozzle #23 that communicates the space 20 of the bracket 21 with the preheating air chamber 12 is provided in the portion of the lid body 9 through which the space 20 of the bracket 21 and the igniter 22 pass, and the fuel spray nozzle 8 and the igniter 22 are connected to each other. The inside of Tsukuia'23 is penetrated leaving an air passage. Furthermore, bracket 2
A space 20 in the bracket 21 is communicated with the air intake duct 5 through the nozzle 24, and a part of the air supplied into the duct 5 from a blower (not shown) is transferred to the space in the bracket 21. 20. As a result, the air supplied to the space 20 in the bracket 21 cools the fuel spray nozzle 8 and the igniter 22 by passing through the inside of the 4-side 23, and then, while cooling the upper cover 25 of the swirler 10, Enter the preheating window room 12. Therefore, heat is prevented from escaping to the outside via the nozzle 8 and the igniter 22, and the temperature of the bracket 21 is not increased.

(Effects) Since the lid used in the combustor of the present invention has a multilayer structure including spaces, there is no heat leak of preheated air.
In addition, it can be made thin and lightweight with a high heat insulating effect. The air flowing from the bracket space to the preheating air chamber cools the fuel injection nozzle and prevents spontaneous combustion inside it.Furthermore, it cools the top cover of the swirler, thereby preventing the swirler from overheating. .

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a combustor according to an example of the present invention, FIG. 2 is an enlarged cross-sectional view of the central portion of a lid, and FIG. 3 is a cross-sectional view of a conventional combustor. In the diagram = 2... Combustion chamber, 3... Heater tube, 4
... Air preheating pipe, 7 ... Combustor main body, 8 ... Fuel spray nozzle, 9 ... Lid body, 10 ... Swirler-112
...Air preheating chamber, 13.19...Cover, 18...
・Insulation space, 21...Bracket, 23...Nonoig.

Claims (1)

[Claims] a main body having a combustion chamber, a heater tube, and a combustion air preheating pipe therein, and an air passage leading to the air preheating pipe on its outer periphery; and a lid covering an opening of the main body; The lid body is composed of a first cover having a heat reflecting plate embedded in a heat insulating material, and a second cover that is spaced apart from the first cover and serves as a top plate having a bracket in the center; A swirler is fixed to a liner that is disposed on the main body to face the second cover and forms a preheating air chamber communicating with the air preheating tube between them, and a fuel spray nozzle held on the bracket is connected to the lid body. the fuel spray nozzle is supported by the lid body and passes through a pipe that communicates the space inside the bracket with the air preheating chamber; A combustor for a Stirling engine, wherein the space communicates with a passage that supplies air to the air passage of the main body.