JP2011137584A - Stirling engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Stirling engine capable of being operated even with small temperature difference by increasing a heat exchange amount with the outside. <P>SOLUTION: This Stirling engine (10) is composed of an expansion cylinder (20) enclosing working fluid (11) and including a displacer piston (23) partitioning between an expansion space (21) and a compression space (22), an output cylinder (30) including a power piston (32) forming an output space (31) communicated with the expansion cylinder (20), a piston/rotating mechanism section (40) for operating the displacer piston (23) and the power piston (32) with phase difference to each other, a heater (61) communicated with the expansion space (21), a cooler (64) communicated with the compression space (22), a regenerator (63) communicating between the heater (61) and the cooler (64), a heater-side pulse convertor (66) communicating the regenerator (63), the heater (61) and the expansion space (21), and a cooler-side pulse convertor (67) communicating the regenerator (63), the cooler (64) and the compression space (22). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a Stirling engine. More specifically, the present invention relates to a Stirling engine that increases the amount of heat exchange with the outside and operates even with a small temperature difference.

  The basic operation of a Stirling engine that has been widely known in the past is that the working fluid in the container is moved by one displacer piston that partitions the high temperature space and the low temperature space in the sealed container or two power pistons that reciprocate with a phase difference. The pressure of the fluid in the container fluctuates by reciprocating both the high temperature and low temperature spaces, and this pressure change is established by taking out or inputting the pressure fluctuation as power by the power piston. Here, the working fluid is a compressible medium that converts heat and mechanical work.

A conventional Stirling engine is disclosed in Patent Document 1, for example. A displacer-type Stirling engine that is a typical Stirling engine will be described with reference to FIG.
The Stirling engine 70 includes an expansion cylinder 20 and an output cylinder 30. The expansion cylinder 20 and the output cylinder 30 enclose the working fluid 11. The expansion cylinder 20 includes a displacer piston 23 that partitions the inside of the cylinder into an expansion space 21 and a compression space 22. On the other hand, the output cylinder 30 includes a power piston 32 that forms an output space 31 communicating with the expansion cylinder 20. In FIG. 9, the output space 31 communicates with the compression space 22 of the expansion cylinder 20.

The displacer piston 23 is reciprocally driven by a displacer piston rod 24 (hereinafter referred to as “D-rod”) connected thereto.
The power piston 32 is reciprocally driven by a power piston rod 33 (hereinafter referred to as “P rod”) connected thereto. The power piston 32 has a function of taking out work from the expansion of the working fluid 11 and a function of giving work to compress the working fluid 11.
The displacer piston 23 and the power piston 32 are configured to operate with a phase difference from each other by the piston / rotation mechanism 40. For example, the displacer piston 23 is mechanically coupled so as to move ahead of the power piston 32 with a phase angle of approximately 90 degrees.

A so-called Scotch / yoke mechanism is used as the piston / rotation mechanism 40. The tip of the D-rod 24 is connected to a displacer drive yoke 42 (hereinafter referred to as “D-yoke”), and a displacer-drive scotch slider 43 (hereinafter referred to as “D-slider”) is connected to the D-yoke 42. Is slidably mounted. The D slider 43 is rotated by a displacer drive gear 44 (hereinafter referred to as “D gear”).
That is, the D · slider 43 slides in the D · yoke 42 while rotating, so that the D · yoke 42 reciprocates vertically in FIG. Accordingly, the displacer piston 23 reciprocates in the vertical direction in FIG. 9 via the D rod 24 connected to the D yoke 40.

On the other hand, the tip of the P rod 33 is connected to a power piston drive yoke 52 (hereinafter referred to as “P • yoke”), and a power piston drive scotch slider 53 (hereinafter referred to as “P • yoke”) is connected to the P • yoke 52. "Slider") is slidably mounted. The P slider 53 is rotated by a power piston drive gear 54 (hereinafter referred to as “P gear”).
That is, the P • slider 53 reciprocates in the vertical direction in FIG. 9 because the P • slider 53 slides in the P • yoke 52 while rotating. Therefore, the power piston 32 reciprocates in the vertical direction in FIG. 9 via the P rod 33 connected to the P yoke 52.

  Further, the D gear 44 and the P gear 54 are meshed so that the displacer piston 23 operates ahead of the power piston 32 at a phase angle of approximately 90 degrees. A flywheel 56 (flywheel) is provided on the rotation output shaft 55 of the P • gear 54.

In the expansion cylinder 20, the expansion space 21 communicates with the heater 61. On the other hand, the compression space 22 communicates with the cooler 64. Furthermore, the heater 61 and the cooler 64 communicate with each other via the regenerator 63.
The heater 61 is a flow path that transfers heat from the external high-temperature heat source 62 to the working fluid 11. On the other hand, the cooler 64 is a flow path that transfers the heat of the external low-temperature heat source 65 to the working fluid 11.
The regenerator 63 exchanges heat between the working fluid 11 that enters and exits the regenerator 63 from the heater 61 and the working fluid 11 that enters and exits the regenerator 63 from the cooler 64. At this time, only the working fluid 11 is allowed to pass between the heater 61 and the cooler 64 while being thermally insulated. For example, structurally, it corresponds to a counter-flow heat storage heat exchanger composed of a large number of thin metal tube bundles.
In addition, said heater 61, the cooler 64, and the regenerator 63 are the structures of an airtight container.

The working fluid 11 is filled in a space surrounded by a sealed container and a piston. The sealed container includes the expansion space 21, the compression space 22, the heater 61, the regenerator 63, the cooler 64, and a flow path connecting them. The sealed container can exchange heat with the outside through the container wall surface.
Even if the displacer piston 23 moves, the entire volume of the closed container does not change. Therefore, the pressure difference of the working fluid 11 in each part in the sealed container is slight. The pressure in the sealed container changes in the expansion space 21, the compression space 22, the heater 61, the regenerator 63, the cooler 64, and each part of the flow path connecting them almost simultaneously at the rising and lowering. On the other hand, the temperature of the working fluid 11 varies greatly in each part.

The operation of the Stirling engine 70 will be described.
First, when the displacer piston 23 is lowered in FIG. 9 by the rotational drive of the D-gear 44, the low-temperature working fluid 11 in the compression space 22 is pushed out. The low-temperature working fluid 11 passes through the cooler 64, the regenerator 63, and the heater 61 in this order, and enters the expansion space 21 at a high temperature. At the same time, according to Boyle-Charles' law, the overall pressure of the closed container increases.
That is, the working fluid 11 flowing out of the compression space 22 is cooled by the low-temperature heat source 65 when it first passes through the cooler 64. In the next regenerator 63, preheating is performed in reverse. In the last heater 61, it is further heated from the high-temperature heat source 62 and becomes a high temperature and flows into the expansion space 21.

The power piston 32 outputs mechanical work to the vicinity of the bottom dead center while descending in FIG. 9 due to the pressure in the sealed container.
That is, the thermal expansion of the working fluid 11 mainly occurs in the heater 61 and the regenerator 63, and the overall pressure of the sealed container increases. That is, the increased pressure propagates to the cooler 64, the compression space 22, and the output space 31 of the output cylinder 30, and pushes down the power piston 32 to output mechanical work.
At this time, since the working fluid 11 performs expansion work while receiving heat from the high-temperature heat source 62 while passing through the heater 61, the working fluid 11 in the expansion space 21 and the heater 61 has a low temperature drop and a high temperature. To be kept.

Next, when the displacer piston 23 rises in FIG. 9 by the rotational drive of the D-gear 44, the high-temperature working fluid 11 in the expansion space 21 is pushed out. The high temperature working fluid 11 sequentially passes through the heater 61, the regenerator 63, and the cooler 64, and enters the compression space 22 at a low temperature. At the same time, the overall pressure in the sealed container drops according to Boyle-Charles' law.
That is, the working fluid 11 flowing out from the expansion space 21 is superheated from the high-temperature heat source 62 when it first passes through the heater 61. In the next regenerator 63, it is precooled in reverse. In the last cooler 64, it receives further cooling from the cold heat source and becomes a low temperature and flows into the compression space 22.

Immediately thereafter, the power piston 32 rises from the bottom dead center with a phase difference of about 90 degrees by the rotational drive of the P-gear 54. The power piston 32 compresses the working fluid 11 in the sealed container whose pressure has dropped.
That is, the power piston 32 compresses the working fluid 11 in the compression space 22 while extruding it to the cooler 64. Since compression is performed while dissipating heat, the temperature rise associated with compression is extremely small compared to adiabatic compression.
The power piston 32 works in order to give the compression work to the working fluid 11. The energy required for the compression work uses a part of the rotational kinetic energy accumulated in the flywheel 56. Alternatively, work energy generated in other cylinders is used as in the case of a multi-cylinder engine.
As described above, the Stirling engine can output continuous mechanical work to the output rotating shaft by repeating the series of operations described above.

JP 9-68104 A

In the conventional Stirling engine 70, the working fluid 11 is a reciprocating flow in both the heater 61 and the cooler 64. Therefore, in the heater 61, the working fluid 11 and the high-temperature heat source 62 fluid exchange heat while repeating the counter flow and the parallel flow. Also in the cooler 64, the working fluid 11 and the fluid of the low-temperature heat source 65 exchange heat while repeating the counter flow and the parallel flow.
As a result, neither the heater 61 nor the cooler 64 can increase the amount of exchange heat. Further, the regenerator 63 is also subjected to a heat load due to the exchange heat quantity, so that loss occurs. However, in both the heater 61 and the cooler 64, the loss cannot be reduced.

The reason is as follows. That is, the working fluid 11 flowing out from the compression space 22 passes through the cooler 64, the regenerator 63, and the heater 61 and reaches a high temperature and flows into the expansion space 21. That is, the working fluid 11 is preheated by the regenerator 63 and heated by the heater 61, but is forced to be cooled in order to first pass through the cooler 64.
On the other hand, the working fluid 11 flowing out from the expansion space 21 passes through the heater 61, the regenerator 63, and the cooler 64, becomes a low temperature, and flows into the compression space 22. That is, the working fluid 11 is precooled by the regenerator 63 and should be cooled by the cooler 64, but is first forced to be heated to pass through the heater 61.
For the above reasons, it has been difficult to operate the Stirling engine 70 using a low-temperature heat source.

  The problem to be solved by the present invention is to increase the amount of heat exchange with the outside, thereby providing a Stirling engine that operates even with a small temperature difference due to a low-temperature heat amount of, for example, 100 ° C. or less, which has conventionally been exhausted heat. There is to do.

(First invention)
The first invention of the present application relates to the following Stirling engine (10).
That is, the cylinder in which the working fluid (11) is sealed communicates with the expansion cylinder (20) having a displacer piston (23) that partitions the expansion space (21) and the compression space (22), and the expansion cylinder (20). An output cylinder (30) having a power piston (32) forming an output space (31), and a piston / rotation mechanism (40) that operates the displacer piston (23) and the power piston (32) with a phase difference from each other. ) And a heater (61) communicating with the expansion space (21) to transfer the heat of the external high-temperature heat source to the working fluid (11), and the heat of the working fluid (11) to the external low-temperature Operates while exchanging heat to transfer to the heat source and communicating between the cooler (64) communicating with the compression space (22), between the heater (61) and the cooler (64), and insulative in temperature. A regenerator (63) capable of passing only the fluid (11), and a three-branch channel communicating between the regenerator (63), the heater (61) and the expansion space (21) A heater-side pulse converter (66) forming a regenerator, a regenerator (63), a cooler (64), and a cooler-side pulse converter (67) And).
The heater-side pulse converter (66) mainly causes the working fluid (11) flowing from the regenerator (63) to flow into the heater (61), and mainly flows the working fluid (11) flowing from the expansion space (21). Let it flow into the regenerator (63).
The cooler-side pulse converter (67) mainly causes the working fluid (11) flowing from the regenerator (63) to flow into the cooler (64), and the working fluid (11) flowing from the compression space (22) mainly. This is the Stirling engine (10) that is supposed to flow into (63).

(Glossary)
The “working fluid” is a fluid that serves as a medium for heat exchange. A gas such as air, helium or hydrogen may be used, or water or other liquid may be used.

(Function)
In the expansion stroke, the displacer piston (23) operates to push out the working fluid (11) in the compression space (22). Most of the working fluid (11) does not pass through the cooler (64) by the cooler-side pulse converter (67), and becomes a high temperature via the regenerator (63) and the heater (61). It flows into (21). The overall pressure in the sealed container increases. Due to the pressure in the sealed container, the power piston (32) outputs mechanical work up to near the bottom dead center.
In the compression stroke, the displacer piston (23) is actuated by the piston / rotation mechanism (40) to push out the working fluid (11) in the expansion space (21). Most of the working fluid (11) does not pass through the heater (61) by the heater-side pulse converter (66), and passes through the regenerator (63) and the cooler (64) to become a low temperature to be compressed space. Enter (22). Immediately after that, the power piston (32) moves from the bottom dead center to the top dead center with a phase difference by the piston / rotation mechanism (40), and compresses the working fluid (11) in the sealed container whose pressure has dropped. To do.
The above expansion process and compression process are repeated to output continuous machine work. Since the back flow (reciprocating flow) of the working fluid 11 does not occur in the heater (61) and the cooler (64), the amount of exchange heat in the heater (61) and the cooler (64) increases. Furthermore, the heat load of the regenerator (63) is reduced.

(Variation 1 of the first invention)
The first invention can also provide the following variations.
That is, a displacer piston rod (24) is connected to the displacer piston (23), and a power piston rod (33) is connected to the power piston (32).
The piston / rotation mechanism (40) includes a displacer / scotch / yoke mechanism (41) that reciprocates the displacer piston rod (24), and a power piston that reciprocates the power piston rod (33). The scotch-yoke mechanism (51), the elliptical displacer elliptical gear (45) that transmits rotational motion to the displacer-scotch-yoke mechanism (41), and the displacer elliptical gear (45). And an elliptical power piston elliptical gear (57) that meshes with a phase difference and transmits rotational motion to the power piston / scotch / yoke mechanism (51).

(Function)
The displacer piston rod (24) connected to the displacer piston (23) is reciprocated by transmitting rotational motion to the displacer, scotch, and yoke mechanism (41) by an elliptical displacer elliptical gear (45). To do.
On the other hand, the power piston rod (33) connected to the power piston (32) is an elliptical power piston elliptical gear (57) that meshes with the displacer elliptical gear (45) with a phase difference. It reciprocates by transmitting rotational motion to the yoke mechanism (51).
Since the elliptical gear is used as described above, the acupressure diagram can be approximated to an ideal cycle. Since the elliptical gear is used, the power piston (32) moves at a high speed when the displacer piston (23) is near the top dead center or the bottom dead center. On the other hand, when the power piston (32) is near the top dead center or the bottom dead center, the displacer piston (23) moves at a high speed.

(Variation 2 of the first invention)
The first invention can also provide the following variations.
That is, a displacer piston rod (24) is connected to the displacer piston (23), and a power piston rod (33) is connected to the power piston (32).
The piston / rotation mechanism section (40) reciprocates the displacer piston rod (24), and a pair of first displacer / scotch / yoke mechanisms (41a) and a second displacer disposed opposite to each other. A pair of first power piston scotch yoke mechanism (51a) and a second power piston scotch, which reciprocate the power piston rod (33) and are disposed opposite to each other. A yoke mechanism (51b), a first displacer scotch yoke mechanism (41a) that transmits a positive rotational motion to the first displacer scotch yoke mechanism (41a), and a second displacer scotch yoke mechanism (41b). The second displacer gear (45b) that transmits reverse rotational movement to the first displacer gear (45a) is engaged with a phase difference. And a first power piston gear (57a) for transmitting a reverse rotational motion to the first power piston / scotch / yoke mechanism (51a) and the second displacer gear (45b) with a phase difference, and And a second power piston gear (57b) that transmits a forward rotation motion to the second power piston / scotch / yoke mechanism (51b).

(Function)
The displacer piston rod (24) connected to the displacer piston (23) reciprocates by a pair of the first displacer scotch yoke mechanism (41a) and the second displacer scotch yoke mechanism (41b). The first displacer gear (45a) transmits a positive rotational motion to the first displacer scotch yoke mechanism (41a), and the second displacer gear (45b) transmits the second displacer scotch yoke mechanism ( Transmits counter-rotating motion to 41b). Accordingly, since the first displacer gear (45a) and the second displacer gear (45b) that are reversed from each other are driven, side thrust does not occur.
On the other hand, the power piston rod (33) connected to the power piston (32) reciprocates between the pair of first power piston / scotch / yoke mechanisms (51a) and second power piston / scotch / yoke mechanism (51b). The first power piston gear (57a) transmits a forward rotational motion to the first power piston / scotch / yoke mechanism (51a), and the second power piston gear (57b) is transmitted to the second displacer / scotch / Reverse rotation motion is transmitted to the yoke mechanism (51b). Therefore, since it is driven by the two first power piston gears (57a) and the second power piston gear (57b) which are reversed to each other, no side thrust is generated.

  According to the first to third aspects of the present invention, there is provided a Stirling engine that increases the amount of heat exchange with the outside and operates even through a small temperature difference caused by a low temperature fluid, for example, 100 ° C. or less. I was able to.

It is a schematic structure figure showing the Stirling engine of an embodiment of the present invention. 1 shows a Stirling engine according to an embodiment of the present invention, and is a schematic configuration diagram of a single cylinder coaxial gamma type. FIG. 3 shows operations in the Stirling engine of FIG. 2, (A) and (B) show an expansion stroke, and (C) and (D) are schematic diagrams showing a compression stroke. (A) shows the flow of the working fluid in the cooler-side pulse converter during the expansion stroke, and (B) is a schematic explanatory diagram showing the flow of the working fluid in the heater-side pulse converter during the expansion stroke. (A) shows the flow of the working fluid in the cooler-side pulse converter during the compression stroke, and (B) is a schematic explanatory diagram showing the flow of the working fluid in the heater-side pulse converter during the compression stroke. It is a shiatsu diagram which shows 1 cycle temperature history (qualitative change) in the Stirling engine of embodiment of this invention. It is a schematic side view which shows the piston and the rotation mechanism part of other embodiment in this invention. It is rough operation explanatory drawing which looked at the piston and rotation mechanism part of other embodiments in the present invention from the front. It is a schematic block diagram which shows the conventional Stirling engine. It is a shiatsu diagram which shows the 1-cycle temperature history (qualitative change) in the conventional Stirling engine.

Embodiments of the present invention will be described below with reference to the drawings.
The Stirling engine 10 according to this embodiment is a displacer type. As shown in FIG. 1, an expansion cylinder 20 and an output cylinder 30 are provided. The expansion cylinder 20 and the output cylinder 30 enclose the working fluid 11. The expansion cylinder 20 includes a displacer piston 23 that partitions the inside of the cylinder into an expansion space 21 and a compression space 22. On the other hand, the output cylinder 30 includes a power piston 32 that forms an output space 31 communicating with the expansion cylinder 20. In FIG. 1, the output space 31 communicates with the expansion space 21 of the expansion cylinder 20.
In addition, the working fluid 11 is a medium for exchanging heat and mechanical work, and gas such as air, helium, and hydrogen, water, or other liquid can be used.

The displacer piston 23 is reciprocally driven by a displacer piston rod 24 (hereinafter referred to as “D-rod”) connected thereto.
The power piston 32 is reciprocally driven by a power piston rod 33 (hereinafter referred to as “P rod”) connected thereto. The power piston 32 has a function of taking out work from the expansion of the working fluid 11 and a function of giving work to compress the working fluid 11.

  The displacer piston 23 and the power piston 32 are configured to operate with a phase difference from each other by the piston / rotation mechanism 40. For example, the displacer piston 23 is mechanically connected so as to move ahead of the power piston 32 at a phase angle of about 90 degrees.

A so-called Scotch / yoke mechanism is used as the piston / rotation mechanism 40.
In the displacer scotch yoke mechanism 41, the tip of the D rod 24 is connected to a displacer drive yoke 42 (hereinafter referred to as “D yoke”), and the displacer drive scotch slider 43 is connected to the D yoke 42. (Hereinafter referred to as “D-slider”) is slidably mounted. The D slider 43 is rotated by a displacer drive gear 44 (hereinafter referred to as “D gear”).
That is, the D · slider 43 slides in the D · yoke 42 while rotating, so that the D · yoke 42 reciprocates in the vertical direction in FIG. Accordingly, the displacer piston 23 reciprocates in the vertical direction in FIG. 1 via the D rod 24 connected to the D yoke 40.

On the other hand, in the power piston / scotch / yoke mechanism 51, the tip of the P / rod 33 is connected to a power piston drive yoke 52 (hereinafter referred to as “P / yoke”). A piston drive scotch slider 53 (hereinafter referred to as “P-slider”) is slidably mounted. The P slider 53 is rotated by a power piston drive gear 54 (hereinafter referred to as “P gear”).
That is, the P · slider 53 reciprocates in the vertical direction in FIG. 1 because the P · slider 53 slides in the P · yoke 52 while rotating. Therefore, the power piston 32 reciprocates in the vertical direction in FIG. 1 through the P rod 33 connected to the P yoke 52.

  Further, the D gear 44 and the P gear 54 are meshed so that the displacer piston 23 operates ahead of the power piston 32 at a phase angle of approximately 90 degrees. A flywheel 56 (flywheel) is provided on the rotation output shaft 55 of the P • gear 54.

  In the expansion cylinder 20, the expansion space 21 communicates with the heater 61. On the other hand, the compression space 22 communicates with the cooler 64. Furthermore, the heater 61 and the cooler 64 communicate with each other via the regenerator 63. In addition, the heater 61, the regenerator 63, and the expansion space 21 communicate with each other via a heater-side pulse converter 66 that is a three-branch flow path. In addition, the cooler 64, the regenerator 63, and the compression space 22 communicate with each other via a cooler-side pulse converter 67 that is a three-branch flow path.

The heater 61 is a flow path that transfers heat from the external high-temperature heat source 62 to the working fluid 11. On the other hand, the cooler 64 is a flow path that transfers the heat of the external low-temperature heat source 65 to the working fluid 11.
The regenerator 63 exchanges heat between the working fluid 11 that enters and exits the regenerator 63 from the heater 61 and the working fluid 11 that enters and exits the regenerator 63 from the cooler 64. At this time, only the working fluid 11 is allowed to pass between the heater 61 and the cooler 64 while being thermally insulated. For example, structurally, it corresponds to a counter-flow heat storage heat exchanger composed of a large number of thin metal tube bundles.

The heater-side pulse converter 66 has a configuration in which the working fluid 11 flowing from the regenerator 63 mainly flows into the heater 61 and the working fluid 11 flowing from the expansion space 21 mainly flows into the regenerator 63.
The cooler side pulse converter 67 has a configuration in which the working fluid 11 flowing from the regenerator 63 mainly flows into the cooler 64 and the working fluid 11 flowing from the compression space 22 mainly flows into the regenerator 63.
The heater 61, the cooler 64, the regenerator 63, the heater-side pulse converter 66, and the cooler-side pulse converter 67 have a sealed container structure.

  The working fluid 11 is filled in a space surrounded by a sealed container and a piston. The sealed container includes the expansion space 21, the compression space 22, the heater 61, the regenerator 63, the cooler 64, the heater side pulse converter 66, the cooler side pulse converter 67, and a flow path connecting them. The sealed container can exchange heat with the outside through the container wall surface.

  Even if the displacer piston 23 moves, the entire volume of the closed container does not change. Therefore, the pressure difference of the working fluid 11 in each part in the sealed container is slight. The pressure in the sealed container is the expansion space 21, the compression space 22, the heater 61, the regenerator 63, the cooler 64, the heater side pulse converter 66, the cooler side pulse converter 67, and each part of the flow path connecting them. Both change towards ascent and descent almost simultaneously. On the other hand, the temperature of the working fluid 11 varies greatly in each part.

Next, specific examples of the Stirling engine 10 of the present embodiment will be described.
FIG. 2 shows a single-cylinder coaxial gamma-type Stirling engine 10. A cylindrical displacer piston 23 is accommodated in the expansion cylinder 20 which also serves as an engine body having a circular cross section so as to be movable up and down in FIG. 2, and is divided into an expansion space 21 and a compression space 22. The output cylinder 30 is formed at the center of the displacer piston 23. A cylindrical D rod 24 that is an extension of the output cylinder 30 is connected to the lower portion of the displacer piston 23.

The power piston 32 is housed in the output cylinder 30 so as to be movable up and down in FIG. 2, forms an output space 31, and is reciprocated by a connected P / rod 33. The output space 31 communicates with the expansion space 21 of the expansion cylinder 20.
The displacer piston 23 and the power piston 32 operate with a phase difference from each other by the piston / rotation mechanism 40a.

  The piston / rotation mechanism 40a is an elliptical gear in which the D • gear 44 and the P • gear 54 have an elliptical shape, and uses a Scotch / yoke mechanism. Since it is basically the same as the above-described piston / rotation mechanism 40, detailed description thereof will be omitted, and different points will be mainly described.

An elliptical displacer drive elliptical gear 45 (hereinafter referred to as “D-elliptical gear”) is a substitute for the aforementioned D-gear 44 and transmits rotational motion to the displacer-scotch-yoke mechanism 41. .
On the other hand, an elliptical power piston drive elliptical gear 57 (hereinafter referred to as “P-elliptical gear”) is a substitute for the P-gear 54 described above. The power piston / scotch / yoke mechanism 51 is meshed with a phase difference of a degree and a rotational motion is transmitted to the power piston / scotch / yoke mechanism 51.

As described above, since the elliptical D / elliptical gear 45 and the elliptical P / elliptical gear 57 are used, the acupressure diagram shown in FIG. 6 can be approximated to an ideal cycle.
Further, since the D / elliptical gear 45 and the P / elliptical gear 57 are used, the power piston 32 moves at a high speed when the displacer piston 23 is near the top dead center or the bottom dead center. On the other hand, when the power piston 32 is near the top dead center or the bottom dead center, the displacer piston 23 moves at a high speed.

The heater 61 is disposed above the upper wall portion of the expansion cylinder 20 in FIG. 2 so that a plurality of U-shaped tubes 61 a communicate with the expansion space 21. The heat of the external high-temperature heat source 62 passes around the plurality of U-shaped tubes 61a, and the working fluid 11 in each U-shaped tube 61a is heated.
The cooler 64 is disposed below the lower wall portion of the expansion cylinder 20 in FIG. 2 so that a plurality of U-shaped tubes 64 a communicate with the compression space 22. The heat of the external low-temperature heat source 65 passes around the plurality of U-tubes 64a, and the working fluid 11 in each U-tube 64a is cooled.
The regenerator 63 is provided in the cylindrical side wall portion of the expansion cylinder 20, and both sides thereof communicate with the expansion space 21 and the compression space 22. The same number is provided as the plurality of U-shaped tubes 61 a of the heater 61 and the plurality of U-shaped tubes 64 a of the cooler 64.

  In the heater-side pulse converter 66, the working fluid 11 flowing out from the heater-side outlet of the regenerator 63 passes through the expansion space 21 and flows into the inlet of the U-shaped tube 61 a of the heater 61. The U-shaped tubes 61a of the heater 61 are disposed. Therefore, the structure is such that the heater-side outlet of the regenerator 63 and the expansion space 21 are communicated, the heater-side outlet of the regenerator 63 and the heater 61 are communicated, and the heater 61 and the expansion space 21 are communicated. It is a flow path.

  The cooler side pulse converter 67 is arranged so that the working fluid 11 flowing out from the cooler side outlet of the regenerator 63 passes through the compression space 22 and flows into the inlet of the U-shaped pipe 64a of the cooler 64. The U-shaped pipes 64a of the cooler 64 are arranged. Therefore, the structure is such that the cooler side outlet of the regenerator 63 and the compression space 22 are communicated, the cooler side outlet of the regenerator 63 and the cooler 64 are communicated, and the three branches that communicate the cooler 64 and the compression space 22. It is a flow path.

  That is, in both the heater-side pulse converter 66 and the cooler-side pulse converter 67, the working fluid 11 is selected while selecting different branch flow paths at the both ends of the regenerator 63 of the regenerator 63. Flowing. Therefore, most of the working fluid 11 of the heater 61 and the cooler 64 has a structure in which even if there is a slight backflow, the working fluid 11 is an intermittent one-way flow.

The operation of both the Stirling engines 10 and 10a shown in FIGS. 1 and 2 will be described. In addition, about the Stirling engine 10 of FIG. 2, FIG. 3 (A)-(D) is referred collectively.
First, the expansion stroke will be described. When the displacer piston 23 is lowered in FIGS. 1, 2, and 3 (A) by the rotational drive of the D-gear 44, the low-temperature working fluid 11 in the compression space 22 is pushed out. Most of the low-temperature working fluid 11 does not pass through the cooler 64 but passes through the regenerator 63 and the heater 61 in order due to the branch flow path characteristics of the cooler-side pulse converter 67.

  In the cooler side pulse converter 67, as shown in FIG. 4A, the low temperature working fluid 11 does not pass through the U-shaped pipe 64a [(1) ′ → (1)] of the cooler 64, and most of the low temperature working fluid 11 is passed through. It passes through the flow path (2) directly entering the regenerator 63. The reason is that the flow loss [(1) ′ → (1)] passing through the U-shaped pipe 64a of the cooler 64 has a higher pressure loss than the flow passage (2).

In the regenerator 63, the working fluid 11 is preheated. In the next heater 61, it is further heated from the high-temperature heat source 62, which is close to counterflow heat exchange, and becomes high temperature and flows into the expansion space 21. At the same time, according to Boyle-Charles' law, the overall pressure of the closed container increases.
Note that most of the working fluid 11 flowing out of the regenerator 63 passes through the heater 61 due to the branch flow path characteristics of the heater-side pulse converter 66. There is little working fluid 11 flowing directly from the regenerator 63 into the expansion space 21.

  In the heater-side pulse converter 66, as shown in FIG. 4B, when the working fluid 11 exits the regenerator 63, the working fluid 11 is not a flow path (2) that directly flows into the expansion space 21, but the U of the heater 61. It passes through the tube 61a [(1) → (1) ′]. The reason is that the outlet dynamic pressure of the regenerator 63 is equal to or higher than the pressure loss of the U-shaped tube 61 a of the heater 61.

The power piston 32 outputs mechanical work to the vicinity of the bottom dead center while descending in FIGS. 1, 2, and 3 (B) due to the pressure in the above-described sealed container.
That is, the thermal expansion of the working fluid 11 mainly occurs in the heater 61 and the regenerator 63, and the overall pressure of the sealed container increases. That is, the increased pressure propagates to the cooler 64, the compression space 22, and the output space 31 of the output cylinder 30, and pushes down the power piston 32 to output mechanical work.
At this time, since the working fluid 11 performs expansion work while receiving heat from the high-temperature heat source 62 while passing through the heater 61, the working fluid 11 in the expansion space 21 and the heater 61 has a low temperature drop and a high temperature. To be kept.

  Next, the compression process will be described. When the displacer piston 23 rises in FIG. 1, FIG. 2 and FIG. 3 (C) by the rotational drive of the D gear 44, the high temperature working fluid 11 in the expansion space 21 is pushed out. Most of the high-temperature working fluid 11 does not pass through the heater 61 but sequentially passes through the regenerator 63 and the cooler 64 due to the branch flow path characteristics of the heater-side pulse converter 66.

  In the heater side pulse converter 66, as shown in FIG. 5 (B), the high temperature working fluid 11 does not pass through the U-shaped tube 61a [(1) ′ → (1)] of the heater 61, and most of the high temperature working fluid 11 passes through. It passes through the flow path (2) directly entering the regenerator 63. The reason is that the pressure loss is higher in the flow path [(1) ′ → (1)] passing through the U-shaped tube 61a of the heater 61 than in the flow path (2).

In the regenerator 63, the working fluid 11 is pre-cooled. In the next cooler 64, the low-temperature heat source 65 receives further cooling, which is close to counterflow heat exchange, and becomes a low temperature and flows into the compression space 22. At the same time, according to Boyle-Charles' law, the overall pressure of the closed container increases.
Note that most of the working fluid 11 flowing out of the regenerator 63 passes through the cooler 64 due to the branch flow path characteristics of the cooling side pulse converter. There is little working fluid 11 flowing directly from the regenerator 63 into the compression space 22.

  In the cooler side pulse converter 67, as shown in FIG. 5A, when the working fluid 11 exits the regenerator 63, the working fluid 11 does not flow directly into the compression space 22 (2), but the U of the cooler 64. It passes through the tube 64a [(1) → (1) ′]. The reason is that the outlet dynamic pressure of the regenerator 63 is equal to or higher than the pressure loss of the U-shaped pipe 64 a of the cooler 64.

Immediately thereafter, the power piston 32 rises in FIG. 1, FIG. 2 and FIG. 3 (D) from the bottom dead center with a phase difference of about 90 degrees by the rotational drive of the P gear 54. The power piston 32 compresses the working fluid 11 in the sealed container whose pressure has dropped.
That is, the power piston 32 extrudes the high-temperature working fluid 11 in the expansion space 21 and compresses it while sequentially passing it through the heater-side pulse converter 66, the regenerator 63, and the cooler 64. Since compression is performed while dissipating heat, the temperature rise associated with compression is extremely small compared to adiabatic compression.
The power piston 32 works in order to give the compression work to the working fluid 11. The energy required for the compression work uses a part of the rotational kinetic energy accumulated in the flywheel 56. Alternatively, work energy generated in other cylinders is used as in the case of a multi-cylinder engine.

  The Stirling engine 10 outputs continuous mechanical work to the output rotation shaft by repeating the above-described series of expansion stroke and compression stroke operations.

As described above, the reverse flow (reciprocal flow) of the working fluid 11 does not occur in the heater 61 and the cooler 64, and the following effects are obtained.
(1) The exchange heat quantity in the heater 61 and the cooler 64 increases.
In the heater 61, the working fluid 11 and the high-temperature heat source 62 fluid exchange counter-current heat, so the amount of heat exchange can be increased. On the other hand, in the cooler 64, since the working fluid 11 and the fluid of the low-temperature heat source 65 exchange countercurrent heat, the amount of heat exchange can be increased.
Moreover, in the heater 61, since the temperature difference between the working fluid 11 and the high-temperature heat source 62 becomes large, the exchange heat amount of the heater 61 increases. The reason is that the temperature of the working fluid entering the heater 61 from the regenerator 63 is lower than that of the conventional reciprocating flow type.
On the other hand, in the cooler 64, the temperature difference between the working fluid 11 and the low-temperature heat source 65 becomes large, so the amount of heat exchanged in the cooler 64 increases. This is because the temperature of the working fluid entering the cooler 64 from the regenerator 63 is higher than that of the conventional reciprocating flow type.

(2) The heat load of the regenerator 63 is reduced.
Since the regenerator 63 is also subjected to a heat load due to the exchange heat quantity, a loss occurs. In other words, the regenerator 63 is efficient, and assuming that the heat exchange efficiency η and the exchange heat quantity QR per cycle, a loss (1 · η) · QR per cycle occurs. If the exchange heat quantity QR can be reduced, the loss also decreases.
In the Stirling engine 10 of the present embodiment, the exchange heat quantity can be reduced to about 0.3 × QR with respect to the exchange heat quantity QR of the conventional Stirling engine 10. Therefore, the loss could be reduced to about 0.3 × (1 · η) · QR.

The above effect is clear when FIG. 6 and FIG. 10 are compared.
FIG. 6 is a shiatsu diagram showing one-cycle temperature history (qualitative change) of each part of the Stirling engine 10 of the present embodiment. On the other hand, FIG. 10 is a shiatsu diagram showing a one-cycle temperature history (qualitative change) of each part of the conventional Stirling engine 10. In any figure, it represents with the same code | symbol.
In the present embodiment, the temperature difference ΔTR of the regenerator 63 is significantly reduced as compared with the prior art, and thus greatly contributes to reducing the no-load of the regenerator 63.
Further, in this embodiment, the heat exchange between the heat source and the working fluid 11 is a counter flow. For example, the high temperature heat source 62 side is in the direction of arrows 9 to 10, and the working fluid 11 side is in the direction of arrows 3. In the present embodiment, the directions of the arrows face each other substantially in parallel as compared with the conventional example. That is, since the temperature difference ΔTHS of the high-temperature heat source 62 can be increased, the characteristics suitable for low temperature use such as exhaust heat are exhibited.

Next, another embodiment relating to the above-described piston / rotation mechanism will be described.
As shown in FIGS. 7 and 8, a piston / rotation mechanism 40b of another embodiment includes a pair of first displacer / scotch / yoke mechanisms 41a (hereinafter referred to as “first” And a second displacer Scotch yoke mechanism 41b (hereinafter referred to as "second D. Scotch yoke mechanism"). The basic structure is the same as the displacer, scotch, and yoke mechanism 41 described above.

  The first D / Scotch / yoke mechanism 41 a and the second D / Scotch / yoke mechanism 41 b are provided at positions facing each other with the D / rod 24 interposed therebetween. That is, the first D slider 44a and the second D slider 43b are slidable at a position facing each other across the D rod 24, with one D yoke 42 connected to the tip of the D rod 24. It is attached to.

  Further, a first displacer elliptical gear 45a (hereinafter referred to as "first D.elliptical gear") that transmits rotational motion to the D.yoke 42 via the first D.slider 43a; A second displacer elliptical gear 45b (hereinafter referred to as "second D. elliptical gear") that transmits rotational motion via the second D / slider 43b is provided. In FIG. 8, the first D / elliptical gear 45a is indicated by a solid line, and the second D / elliptical gear 45b is indicated by a dotted line.

  The first D / elliptical gear 45a and the second D / elliptical gear 45b are provided at positions facing each other with the D / rod 24 interposed therebetween, and are configured to rotate in directions opposite to each other. For example, the first D oval gear 45a rotates in the clockwise direction (forward rotation direction) in FIG. 8, and the second D oval gear 45b in the counterclockwise direction (reverse rotation direction) in FIG. Rotate towards. Details of the inverted structure will be described later.

  In addition, as shown in FIGS. 7 and 8, the piston / rotation mechanism 40b includes a pair of first power piston / scotch / yoke mechanisms 51a (hereinafter referred to as “first”). And a second power piston / scotch / yoke mechanism 51b (hereinafter referred to as “second P / scotch / yoke mechanism”). The basic structure is the same as that of the power piston / scotch / yoke mechanism 51 described above.

  The first P / Scotch / yoke mechanism 51 a and the second P / Scotch / yoke mechanism 51 b are provided at positions facing each other across the P / rod 33. In other words, the P / D / yoke 52, to which the tip of the P / rod 33 is connected, is located at a position where the first P / slider 53a and the second P / slider 53b face each other across the P / rod 33. It is slidably mounted.

  Further, a first power piston elliptical gear 57a (hereinafter referred to as "first P. elliptical gear") that transmits rotational motion to the P • D • yoke 52 via the first P • slider 53a; A second power piston elliptical gear 57b (hereinafter referred to as "second P. elliptical gear") that transmits rotational motion via the second P.slider 53b is provided. In FIG. 8, the first P / elliptical gear 57a is indicated by a solid line, and the second P / elliptical gear 57b is indicated by a dotted line.

  The first P / elliptical gear 57a and the second P / elliptical gear 57b are provided at positions facing each other with the P / rod 33 interposed therebetween, and are configured to rotate in directions opposite to each other. Moreover, the first P / elliptical gear 57a meshes with the first D / elliptical gear 45a with a phase difference, that is, a phase difference of 90 degrees in this embodiment. On the other hand, the second P / ellipse gear 57b meshes with the second D / ellipse gear 45b with a phase difference of 90 degrees.

Further, a structure in which the first D / elliptical gear 45a and the second D / elliptical gear 45b, and the first P / elliptical gear 57a and the second P / elliptical gear 57b are mutually inverted will be described.
The first rotation output shaft 55a of the first P / elliptical gear 57a is integrally provided with a first rotation transmission gear 58a made of, for example, a bevel gear. On the other hand, the second rotation output shaft 55b of the second P / elliptical gear 57b is integrally provided with a second rotation transmission gear 58a made of, for example, a bevel gear. The first rotation transmission gear 58a and the second rotation transmission gear 58b have the same diameter and the same number of teeth, and the major diameter of the first P / elliptical gear 57a and the second P / elliptical gear 57b. The diameter is larger than the major axis dimension.
Therefore, the lowest positions of the first rotation transmission gear 58a and the second rotation transmission gear 58b are located below the first P / elliptical gear 57a and the second P / elliptical gear 57b.
Further, as shown in FIGS. 7 and 8, the third rotation transmission gear 58c made of, for example, a bevel gear is at the lowest position of the first rotation transmission gear 58a and the lowest position of the second rotation transmission gear 58b. It is attached so as to mesh.

With the above configuration, the first P / elliptical gear 57a and the second P / elliptical gear 57b are reversely rotated by the meshing operation of the first rotation transmission gear 58a, the second rotation transmission gear 58b, and the third rotation transmission gear 58c. Rotate to. Further, the first D / elliptical gear 45a meshing with the first P / elliptical gear 57a and the second D / elliptical gear 45b meshing with the second P / elliptical gear 57b rotate in directions opposite to each other.
For example, the first P / elliptical gear 57a rotates in the counterclockwise direction (reverse rotation direction) in FIG. 8, and the second P / elliptical gear 57b rotates in the clockwise direction (forward rotation direction) in FIG. Rotate towards.
Accordingly, the first D / elliptical gear 45a rotates in the clockwise direction (forward rotation direction) in FIG. 8, and the second D / elliptical gear 45b rotates in the counterclockwise direction (reverse rotation) in FIG. Direction).
As a result, one P · D · yoke 52 is driven by the two first P · sliders 53a and the second P · slider 53b which are reversed to each other, so that no side thrust is generated.
Further, since one D · yoke 42 is driven by two first D · sliders 43a and second D · sliders 43b that are reversed to each other, no side thrust is generated.

From the above, by driving one yoke with two scotch sliders that are reversed, a scotch-yoke mechanism that does not generate side thrust can be achieved.
In the case of one scotch-yoke mechanism as shown in FIG. 2, since one scotch is used, a rotational moment is generated in the yoke. Therefore, a lateral force, that is, a side thrust is generated on the end face of the yoke and the guide of the yoke. Side thrust greatly affects the durability and life of reciprocating engines.
However, by driving the yoke with two scotches that are reversed, the side thrust cancels out in the rigid yoke, so that the side thrust is extremely small.

In the piston / rotation mechanism 40b of the above-described embodiment, the first D / elliptical gear 45a, the second D / elliptical gear 45b, the first P / elliptical gear 57a, and the second P / elliptical gear have an elliptical shape. 57b is used, but the present invention is also applicable to the first D-gear 44, the second D-gear 44, the P-gear 54, and the second P-ellipse gear 54, which have a normal circular shape.

DESCRIPTION OF SYMBOLS 10 Stirling engine 11 Working fluid 20 Expansion cylinder 21 Expansion space 22 Compression space 23 Displacer piston 24 Displacer piston rod (D rod)
30 Output cylinder 31 Output space 32 Power piston 33 Power piston rod (P · rod)
40, 40a, 42b Piston / rotating mechanism 41 Displacer / Scotch / Yoke mechanism (D / Scotch / Yoke mechanism)
41a First Displacer Scotch Yoke Mechanism (First D Scotch Yoke Mechanism)
41b Second Displacer Scotch Yoke Mechanism (Second D Scotch Yoke Mechanism)
42 Displacer Drive Yoke (D ・ Yoke)
43 Displacer Drive Scotch Slider (D ・ Slider)
43a First Displacer Drive Scotch Slider (First D Slider)
43b Second displacer drive scotch slider (second D-slider)
44 Displacer Drive Gear (D ・ Gear)
45 Displacer Drive Elliptical Gear (D / Oval Gear)
45a 1st displacer drive elliptical gear (1st D oval gear)
45b Second displacer drive elliptical gear (second D-elliptical gear)
51 Power Piston / Scotch / Yoke Mechanism (P / Scotch / Yoke Mechanism)
51a First Power Piston Scotch Yoke Mechanism (First P Scotch Yoke Mechanism)
51b Second power piston / Scotch / Yoke mechanism (Second P / Scotch / Yoke mechanism)
52 Power Piston Drive Yoke (P ・ Yoke)
53 Power Piston Drive Scotch Slider (P ・ Slider)
53a 1st power piston drive scotch slider (1st P slider)
53b Second Power Piston Drive Scotch Slider (Second P / Slider)
54 Power Piston Drive Gear (P ・ Gear)
55 rotation output shaft 55a first rotation output shaft 55b second rotation output shaft 56 flywheel 57 power piston drive elliptic gear (P-elliptic gear)
57a 1st power piston drive oval gear (1st P oval gear)
57b 2nd power piston drive elliptical gear (2nd P, elliptical gear)
58a First rotation transmission gear 58b Second rotation transmission gear 58c Third rotation transmission gear 61 Heater 61a U-shaped tube 62 High temperature heat source 63 Regenerator 64 Cooler 64a U-shaped tube 65 Low temperature heat source 66 Heater side pulse converter 67 Cooler Side pulse converter 70 Stirling engine

Claims (3)

An expansion cylinder having a displacer piston for partitioning the inside of the cylinder enclosing the working fluid into an expansion space and a compression space;
An output cylinder having a power piston that forms an output space communicating with the expansion cylinder;
A piston / rotation mechanism that operates the displacer piston and the power piston with a phase difference from each other;
A heat exchanger for exchanging heat from an external high-temperature heat source to the working fluid, and in communication with the expansion space;
A cooler that exchanges heat to transfer the heat of the working fluid to an external low-temperature heat source and communicates with the compression space;
A regenerator that communicates between the cooler and the heater and that allows only the working fluid to pass while being thermally insulated;
A heater-side pulse converter that forms a three-branch flow path that communicates between the regenerator, the heater, and the expansion space;
A cooler side pulse converter that forms a three-branch flow path communicating between the regenerator, the cooler, and the compression space;
The heater-side pulse converter mainly causes the working fluid flowing from the regenerator to flow into the heater, and causes the working fluid flowing from the expansion space to flow mainly into the regenerator.
The cooler-side pulse converter is a Stirling engine in which the working fluid flowing from the regenerator mainly flows into the cooler and the working fluid flowing from the compression space mainly flows into the regenerator. A displacer piston rod is connected to the displacer piston, a power piston rod is connected to the power piston,
The piston / rotation mechanism section includes a displacer / scotch / yoke mechanism that reciprocates the displacer piston rod;
A power piston, scotch, and yoke mechanism that reciprocates the power piston rod;
An elliptical displacer elliptic gear that transmits rotational motion to the displacer scotch yoke mechanism;
Engaging the displacer elliptical gear with a phase difference and transmitting rotational motion to the power piston / scotch / yoke mechanism, an elliptical power piston elliptical gear;
The Stirling engine according to claim 1, comprising: A displacer piston rod is connected to the displacer piston, a power piston rod is connected to the power piston,
The piston / rotation mechanism reciprocates the displacer piston rod, and a pair of first displacer / scotch / yoke mechanisms and a second displacer / scotch / yoke mechanism,
Reciprocating the power piston rod, and a pair of first power piston / scotch / yoke mechanism and a second power piston / scotch / yoke mechanism disposed opposite to each other;
A first displacer gear for transmitting a positive rotational motion to the first displacer scotch yoke mechanism;
A second displacer gear for transmitting a reverse rotational movement to the second displacer scotch yoke mechanism;
A first power piston gear that meshes with the first displacer gear with a phase difference and transmits a reverse rotational motion to the first power piston / scotch / yoke mechanism;
A second power piston gear that meshes with the second displacer gear with a phase difference and transmits a positive rotational motion to the second power piston / scotch / yoke mechanism. The Stirling engine according to claim 2.

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