JPS6336052A - High temperature heat exchanger of stirling engine - Google Patents

Abstract

PURPOSE:To increase the performance of heat transfer to a heater tube provided through plural opening parts and passages and reduce the exhaust temp. of a combustion gas by circulating said combustion gas by convection in each of said opening parts and passages before exhausting. CONSTITUTION:In a combustion chamber 21 in a housing 10, fuel injected from a burner 15 is mixed with air introduced from a swirler 16 by means of a burner tile 14 and, then, ignited for combustion. And, the combustion gas is exhausted from the center of the combustion chamber 21 through an exhaust port 23, after passing through plural opening parts 26-28 and passages 22, 21 in order. In this case, a heater tube 11 which runs through the opening parts 26, 27 and passages 22, 21 efficiently absorbs the quantity of heat of the combustion gas by convection. Also, radiating members 17-19 which are heated by the combustion gas by convection heat the heater tube 11 by radiant heat. As a result, the performance of heat transfer to the heater tube 11 is increased, thereby, reducing the exhaust temp. of the combustion gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a high temperature heat exchanger for a Stirling engine.

(Prior art) The conventional high-temperature heat exchanger for a Stirling engine is disclosed in Japanese Patent Application Laid-open No. 1983-
There is one shown in Japanese Patent No. 63347. As shown in FIG. 3, this has a large number of heater tubes 3, which are held in a housing 1 and arranged in parallel with a gap between them on the circumferential side of a combustion chamber 2, as heaters with a working fluid sealed inside. Further, the combustion gas is communicated with the burner tile 4 so as to flow from the center of the combustion chamber 2 through between the heater tubes 3 in the circumferential direction, so that the working fluid in the heater tubes 3 is convectively heated by the combustion heat. An upstream side 5 of the heater tube 3 that is equipped with a combustor and faces the inner shaft of the combustion chamber 2, and an upstream side 5 of the heater tube 3 that faces the periphery of the combustion chamber 2;
The downstream side 6 of the heater tube 3 facing the periphery of the combustion chamber 2
A porous or net-like radiator 7°8 was disposed in each of the radiators to allow combustion gas to flow therethrough.

(Problems to be Solved by the Invention) According to the above configuration, in order to bring the temperature of the heater to an average of 750°C, the temperature of the radiator must be increased to 800°C or higher. Therefore, the temperature of the exhaust gas flowing out to the air preheater through the radiator is as high as 850°C or higher. As a result, there was a possibility that the efficiency of the engine would decrease or the air preheater would be damaged.

Therefore, the technical object of the present invention is to reduce the temperature of the exhaust gas discharged to the air preheater.

[Structure of the Invention] (Means for Solving the Problems) The technical means taken in the present invention to solve the above technical problem is to provide a cylindrical tube that surrounds the combustion chamber and hangs down from the upper part of the housing. a cylindrical second radiating member that is erected from the lower part of the housing and has a larger diameter than the first radiating member; and a cylindrical second radiating member that is suspended from the upper part of the housing and has a larger diameter than the second radiating member. a third radiant member having a shape;
a first opening formed between a lower end of the first radiant member and a lower part of the housing and facing the combustion chamber;
A first passage formed between the first radiating member and the second radiating member and communicating with the first opening, and a first passage formed between the upper end of the second radiating member and the upper part of the housing. a second opening communicating with the first passage; a second passage formed between the second radiating member and the third radiating member and communicating with the second opening; and a lower end of the third radiating member. and a third opening formed between the third opening and the lower part of the housing and communicating with the second passage and further communicating with the discharge port, and a third opening located inside the third opening and buried in the lower part of the housing. an expansion cylinder, a regenerator located at a lower part of the second passage and embedded in the lower part of the housing; The present invention includes a heater tube connecting the expansion cylinder and the regenerator.

(Operation) The above technical means operates as follows. That is, the high-temperature combustion gas burned in the combustion chamber passes through the first opening and further passes through the first passage from bottom to top. Furthermore, the second
It turns back at the opening and passes through the second passage from top to bottom, leading to the exhaust port through the third opening. In this way, the combustion gas convects and flows through the passage and is exhausted.
Heat transfer performance to the heater tube disposed within the opening is increased. This allows the exhaust temperature to be reduced.

(Example) An embodiment of the present invention will be described based on the accompanying drawings.

1 and 3, a high-temperature heat exchanger for a Stirling engine has a housing 10 having a combustion chamber 12 of a predetermined volume therein. The housing 10 holds a burner 15 that communicates with a fuel supply source (not shown) and injects fuel into the combustion chamber 12 . This burner 15
A swirling flow path 20 is arranged around and tangentially to this.

Furthermore, a swirler 16 for swirling and introducing combustion air into the combustion chamber 12 is provided. A hollow cylindrical burner tile 14 that mixes fuel and air and burns the mixture is disposed near the swirler 16.

Furthermore, a cylindrical first radiating member 17 is attached to the periphery of the combustion chamber 12 from the upper part of the housing 10 so as to surround the combustion chamber 12.
is hanging down. A first opening 26 is formed between the lower end of the first radiating member 17 and the lower part of the housing 10 . Furthermore, a cylindrical second radiating member 18 having a larger diameter than the first radiating member 17 is provided upright from the lower part of the housing 10 .

A second opening 27 is formed between the upper end of the second radiating member 18 and the upper part of the housing 10 . Also, the first
A first passage 22 is formed between the radiant member 17 and the second radiant member 18 . Furthermore, a cylindrical third radiating member 19 having a larger diameter than the second radiating member 18 is suspended from the upper part of the housing 10 . A third opening 28 is formed between the lower end of the third radiating member 19 and the lower part of the housing 10. Further, a second passage 21 is formed between the second radiating member 18 and the third radiating member 19. Furthermore, an expansion cylinder 24 is embedded in the lower part of the housing 10 inside the first opening 26 .

Further, a regenerator is embedded in the lower part of the housing 10 in the lower part of the second passage 21. From this expansion cylinder, R is vertical toward the top, horizontal within the first opening 26, vertical toward the top in the first passage 22, and changed in direction by 180 degrees at the second opening 27. The second passage 21 has a heater tube 11 which is vertical toward the bottom and connected to the regenerator 13. A large number of heater tubes 11 are arranged in parallel on the peripheral edge side of the combustion chamber 12 with a predetermined gap in between (FIG. 2).

Further, the heater tube 11 in the second passage 21 is provided with a large number of rings 25 to further improve the heat transfer effect.

Next, the operation will be explained. In FIG. 1, fuel injected into a combustion chamber 21 in a housing 10 through a burner 15 is mixed with air swirled through a swirler 16 in a burner tile 14, and ignited and burned by an additive device (not shown). High-temperature combustion gas generated by combustion passes from the center of the combustion chamber 12 through the first opening 26 to the first passage 22, the second opening 27. Second passage 21. The third opening portion 28 and the through hole are exhausted from the exhaust port 23. This leads to the first. The second opening portion 26.27 and the first opening portion 26.27. Second passage 22.
The heater tube 11 passing through the first . Second.
The third radiant members 17, 18, and 19 are heated by the convection of the combustion gas, emit side heat, and heat the heater tube 11 by thermal radiation.

〔Effect of the invention〕

The present invention includes a cylindrical first radiating member that surrounds a combustion chamber and is suspended from an upper part of a housing, and a cylindrical second radiating member that is erected from a lower part of the housing and has a larger diameter than the first radiating member. a cylindrical third radiating member that hangs down from the upper part of the housing and has a larger diameter than the second radiating member;
a first opening formed between a lower end of the first radiant member and a lower part of the housing and facing the combustion chamber;
A first passage formed between the first radiating member and the second radiating member and communicating with the first opening, and a first passage formed between the upper end of the second radiating member and the upper part of the housing. a second opening communicating with the first passage; a second passage formed between the second radiating member and the third radiating member and communicating with the second opening; and a lower end of the third radiating member. and a third opening formed between the housing and the lower part of the housing and communicating with the second passage and further communicating with the discharge port; and an expansion valve located inside the first opening and buried in the lower part of the housing. a cylinder, a regenerator located at a lower part of the second passage and buried in a lower part of the housing, and the first opening;
Since the high-temperature heat exchanger for the Stirling engine is configured by including a heater tube that connects the expansion cylinder and the regenerator through the first passage, the second opening, and the second passage, the combustion Since the gas is exhausted through convection within the opening and the passage, the heat transfer performance to the heater tube disposed within the opening and the passage increases, thereby reducing the exhaust temperature when exhausting the combustion gas. be able to. or,
As the temperature of the combustion gas decreases, the temperature of the gas passing through the heater tube also decreases. This makes it possible to reduce the heat load on the regenerator, thereby improving the output and efficiency of the engine.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a high-temperature heat exchanger according to the present invention, FIG. 2 is a cross-sectional view of the high-temperature heat exchanger, and FIG. 3 is a cross-sectional view of a conventional high-temperature heat exchanger. 10...Housing, 11...Heater tube,
12... Combustion chamber, 13... Regenerator.

Claims (1)

[Claims] a cylindrical first radiating member that surrounds the combustion chamber and is suspended from the upper part of the housing; a cylindrical second radiating member that is erected from the lower part of the housing and has a larger diameter than the first radiating member; and the housing. a third radiating member that is cylindrical and has a larger diameter than the second radiating member, and is formed between the lower end of the first radiating member and the lower part of the housing, and faces the combustion chamber. a first opening formed between the first radiating member and the second radiating member and communicating with the first opening; a first passage formed between the upper end of the second radiating member and the housing; a second opening formed between the upper part and communicating with the first passage; a second passage formed between the second radiating member and the third radiating member and communicating with the second opening; a third opening formed between a lower end of the third radiant member and a lower part of the housing and communicating with the second passage and further communicating with the discharge port; and a third opening located inside the first opening. an expansion cylinder buried in the lower part of the housing; a regenerator located in the lower part of the second passage and buried in the lower part of the housing; the first opening; the first passage;
A high temperature heat exchanger for a Stirling engine, comprising a heater tube connecting the expansion cylinder and the regenerator through the second opening and the second passage.