JPS61226547A - Combustor for stirling engine - Google Patents

Abstract

PURPOSE:To improve the thermal efficiency and the durability of heater tube by arranging combustion gas straightner while keeping into tight contact with the fins provided on the heater tube of Stirling engine. CONSTITUTION:The heater tube 104 to be piped in the combustion chamber at the top of Stirling engine is arranged in circle around the combustion chamber to receive the combustion gas in the combustion chamber at the central side and heated thus to heat the working gas flowing through the interior. Fins are provided to the heater tube 104 in parallel with the gas flow and a straightner 10 is provided while brought into tight contact against the outercircumference of fins. Consequently, the combustion gas will contact reliably against the fins to improve the thermal efficiency while the radiation heat of the straightner 10 and the heat of the straightner itself will transmit to the heater tube to improve the thermal efficiency furthermore thus to eliminate burning due to local heating of fins resulting in improvement of durability.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to improvements in combustors for Stirling engines.

(Prior Art) Conventionally, a combustor for a Stirling engine has a structure as shown in FIG. That is, the Stirling MRxi combustor includes a housing 100 having a combustion chamber 108 and a combustion gas exhaust port 109, a nozzle 106 for injecting fuel,
An air swirler 107 that supplies air, a cylinder 101 that operates a load, a heat exchanger housing 102, and a heater that reciprocates working gas between the cylinder 101 having heat absorption fins 105 and the heat exchanger housing 102. It consisted of a tube 104. The combustion chamber 1
For example, as the fin 105 for absorbing heat from the combustion gas of No. 08, a structure shown in FIG.
It is known as 863451.

This figure is a sectional view of the heater tube taken along the center line. In this case, the heater tubes include a first tube 116 connected to the cylinder, second and third tubes 114, 115 integrated with fins 125 connected to the heat exchanger housing, and and a fourth tube 130 connecting the third tube. Arrow B
indicates the direction of movement of combustion gas.

Furthermore, another example is a structure in which the fins 126 and the heater tube 118 are manufactured separately and integrated, as shown in a plan view and a sectional view, respectively, in FIGS. 6(a) and 6(b).

However, in the case of the structure shown in FIGS. 6 and 7 described above, the direction in which the combustion gas flows is as shown in FIG. 8, which is a plan view thereof. In other words, the combustion gas having high-temperature heat flows from the introduction direction 150 to the discharge direction 151 and does not flow behind the heater tube 119. Therefore, the combustion gas does not efficiently exchange heat with the rear portion 120 of the heater tube 119.

(Problems to be Solved by the Invention) Therefore, the present invention improves the heat exchange rate between the combustion gas and the heater tube by arranging a rectifying plate so that the flow of the combustion gas goes behind the heater tube. The purpose is to improve the overall efficiency of the combustor.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a housing having a combustion chamber, and a large number of housings held in the housing and arranged in parallel at intervals on the inner circumferential side of the combustion chamber. A combustor for a Stirling engine, comprising a heater tube and a burner held in the housing and injecting fuel into the fuel chamber, in which combustion gas flows from the center of the combustion chamber toward the periphery through between the heater tubes. In this, a portion of the heater tube on the peripheral edge side of the combustion chamber has a plate-shaped fin extending in a direction substantially perpendicular to the axial direction of the heater tube, and the combustion chamber includes adjacent heater tubes having the fin. This combustor for a Stirling engine is characterized by comprising a baffle plate that guides the air to the rear between the two.

The housing, numerous heater tubes and fins, and burner can be used as they are in conventional equipment.

The baffle plate disposed at the peripheral edge of the heater tube is a member that guides high-temperature combustion gas generated when fuel is combusted in the burner to the back of the heater tube. It is desirable that the rectifying plate is made of a material having high thermal conductivity so that the amount of heat obtained from the combustion gas is conducted or radiated to the heater tube. Furthermore, it is necessary that the baffle plate does not melt or deform at the temperature of the combustion gas. In addition, from the viewpoint of increasing the surface area, it is desirable that the rectifying plate has a corrugated shape or a flat plate, or is arranged between adjacent tubes with its top facing the direction of movement of the working gas. A roughly ■-shaped or roughly T-shaped shape is preferable.

(Function) The housing holds and houses the combustion chamber and the burners and other components disposed in the combustion chamber.

The fuel supplied to the device of the present invention is injected from the burner of the combustion chamber and combusted. The combustion generates high-temperature combustion gas. The combustion gas moves in the direction of the exhaust port of the combustion chamber. The heater tube disposed at the peripheral edge of the combustion chamber and the fins disposed on the heater tube absorb heat from the combustion gas mainly through convection. On the other hand, a rectifying plate disposed at the peripheral edge of the heater tube guides combustion gas from the center of the combustion chamber toward the exhaust port along the outer peripheral portion of the heater tube. Therefore, the heater tube absorbs the amount of heat by radiation or heat conduction from the peripheral edge side opposite to the center of the combustion chamber by the baffle plate. Therefore, the heater tube absorbs heat from the combustion gas almost over its entire circumferential edge by means of the baffle plate.

(Example) Hereinafter, the present invention will be explained in detail based on a specific first example.

The combustion chamber, housing, burner, etc. are the same as the conventional equipment. Therefore, the overall configuration is almost the same as the conventional device shown in FIG. That is, the difference between the device of the first embodiment and the conventional device is that a rectifying plate is added to the heater tube.

A detailed plan view of the current plate 10 used in the first embodiment is shown in the first example.
Shown in Figure (a). FIG. 2B is a perspective view of the current plate 10 arranged in a large number of heater tubes 104. That is, the heater tube 104 of the conventional device and the fin 105 of the conventional device are provided. A rectifying plate 10 having a substantially V-shaped cross section and a predetermined length is brazed to the end face of a conventional fin 105. For example, the baffle plate 10 directs combustion gas from the center of the combustion chamber toward the exhaust port,
As shown in FIG. 2A, the air is guided from the center direction 150 to the exhaust port direction 151. Top portion 10 of the current plate 10
C directs combustion gas to adjacent heater tubes 104 and 10.
4 to the respective peripheries. Furthermore, the skirt portion 10S110T of the baffle plate 10 guides the combustion gas to the surface of each of the heater tubes 104 facing the center side of the combustion chamber.

Housing 100 holds and houses components such as combustion chamber 108 and burner 106. The fuel supplied to the device of the present invention is supplied to a burner 1 having a discharge port in the combustion chamber 108.
It is ejected from 06 and burned. The combustion generates high-temperature combustion gas. The combustion gas flows into the combustion chamber 1
Move in the direction of the 08 exhaust port. The heater tube 104 disposed around the periphery of the combustion chamber 108 and the fins 105 disposed on the heater tube absorb heat from the combustion gas mainly through convection. On the other hand, the baffle plate 10 disposed on the heater tube 104 guides the combustion gas from the center of the combustion chamber toward the exhaust port along the outer periphery of the heater tube 104 . Therefore, the heater tube 10
4 absorbs the amount of heat from the peripheral edge side of the combustion chamber 108 by the current plate 10 through radiation and heat conduction. Accordingly, the heater tube 104 absorbs heat from the combustion gas through the baffle plate 10 substantially over its entire circumference.

According to the first embodiment, by adding a rectifier plate having a substantially V-shaped cross section to the conventional combustor for a Stirling engine, combustion gas from the combustion chamber can be guided to the rear surface of the heater tube. , the heat exchange rate provided from the combustion gas to the heater tube is improved.

Next, a second embodiment will be described. The second embodiment is substantially the same as the first embodiment, except that the shape of the current plate is different.

The shape of the current plate 20 is shown in FIG. That is, the cross-sectional shape is approximately V-shaped like the first embodiment, but the bending angles of the skirt portions 20S and 20T are different, and the length of the single straightening plate 20 is different from the length of the fin installation interval. It must be sized. In this case, the current plate 20 is, for example,
It is fixed by welding to the fin 135 at locations 20A and 20B.

In the case of the second embodiment, heat exchange is performed in the same manner as in the first embodiment, and almost the same effect can be obtained.

The third and fourth practical examples will be described below.

In the third embodiment, as shown in FIG. 3, a straightening plate 30 having a substantially T-shaped cross section and made of a continuous material is used. The fourth embodiment, as shown in FIG. 4, uses a plate-shaped rectifying plate 40 fixed to a continuous fin 136. In the third and fourth embodiments described above, substantially the same effects as in the first embodiment can be obtained.

[Effects of the Invention] For example, in order to eliminate the drawbacks of the prior art, it is conceivable to erect a baffle plate behind the fin portion of the heater tube. However, although this can improve the flow distribution of high-temperature gas, the heat m given when high-temperature gas collides with this baffle plate is not used very effectively other than being radiated to the surroundings by radiation. Furthermore, there is a problem in that the temperature of this material increases and it eventually burns out. However, according to the present invention, by providing a housing having a combustion chamber, a heater tube, a burner, and a rectifying plate disposed on the heater tube and guiding it to the outer circumferential side, combustion is not performed as in the conventional device. The heat exchange rate between the heater tube and the combustion gas is improved because the gas is guided along the outer circumferential side of the heater tube without being guided behind the heater tube and moving to the exhaust port. More specifically, the current plate has a portion that comes into close contact with the fins. The amount of heat applied to the rectifying plate is transmitted to the fins by heat transfer from the radiation applied to the heater tube. Therefore, the current plate has a unique effect of heating the working gas within the heater tube. The amount of heat contained in the high-temperature gas is effectively used. This means that the temperature of the current plate does not rise more than necessary. That is, the problem of burning out of the current plate does not occur.

[Brief explanation of drawings]

FIG. 1 to FIG. 4 each show a specific first embodiment of the present invention.
FIG. 7 is an explanatory diagram showing the shape and arrangement of a current plate used in a Stirling engine combustor according to a fourth embodiment. Fifth
7 to 7 are a combustor for a Stirling engine, a shape of a fin disposed on a heater tube, and a cross-sectional view of a fin disposed on a heater tube, respectively, which are used to explain the prior art. FIG. 8 is an explanatory diagram showing the flow of combustion gas in the prior art.

Claims (4)

[Claims] (1) A housing having a combustion chamber; a large number of heater tubes held in the housing and arranged in parallel at intervals on the inner circumferential side of the combustion chamber; held in the housing and supplying fuel to the fuel chamber; In a combustor for a Stirling engine, the part of the heater tube on the periphery side of the combustion chamber is The combustion chamber has plate-shaped fins extending substantially perpendicular to the axial direction of the heater tube, and the combustion chamber is provided with the combustion gas on the peripheral edge side facing the gap between adjacent heater tubes having the fins. A combustor for a Stirling engine, comprising a rectifying plate that guides the heater tube from the gap to the rear of the heater tube. (2) The combustor for a Stirling engine according to claim 1, wherein the flow landing plate is plate-shaped. (3) The combustor for a Stirling engine according to claim 1, wherein the current plate has a substantially V-shaped cross section and is disposed with its top facing toward the center of the gap between adjacent heater tubes. (4) The combustor for a Stirling engine according to claim 1, wherein the rectifier plate has a substantially T-shaped cross section and is disposed with the tip of the center portion facing toward the center of the gap between adjacent heater tubes.