JP5035109B2 - External combustion engine - Google Patents

Description

  The present invention relates to an external combustion engine that converts a displacement of a liquid portion of a working medium caused by a change in the volume of vapor of the working medium into mechanical energy and outputs the mechanical energy.

  Conventionally, this type of external combustion engine is described in Patent Document 1. In this conventional technique, a working medium is sealed in a tubular container in a liquid state, and a part of the liquid working medium in the container is heated by a heater to be vaporized, and the vapor of the vaporized working medium is cooled. By cooling with a vessel and liquefying, the displacement of the liquid portion (liquid piston) of the working medium caused by the volume fluctuation of the working medium vapor is converted into mechanical energy and output.

  Moreover, in this prior art, the diameter of the tubular container is expanded in a disk shape at the heated portion where the liquid working medium is heated and vaporized. The liquid working medium flows from the central part of the heated part, and is heated and vaporized in the process of spreading from the central part of the heated part toward the outer peripheral part.

According to this prior art, in the heated part, the liquid working medium flowing in from the central part of the heated part collides with the inner wall surface of the heated part and then flows toward the outer peripheral part of the heated part. In this way, the liquid working medium collides with the inner wall surface of the heated part, and the liquid working medium is agitated to generate turbulent flow, so that the temperature boundary layer near the inner wall surface of the heated part is destroyed. Is done. As a result, the heat exchange efficiency in the heated part can be improved.
Japanese Patent Laid-Open No. 2007-247592

  However, in this prior art, since the heated portion is enlarged in a disc shape, the working medium flows from the central portion of the heated portion to the outer peripheral portion. In other words, the flow path cross-sectional area of the working medium increases from the center of the heated portion toward the outer periphery.

  For this reason, since the working medium flows more concentratedly in the center of the heated part than in the outer peripheral part, the temperature of the wall surface decreases in the central part of the heated part as compared with the outer peripheral part. A temperature difference will occur between the part and the outer peripheral part. As a result, there is a problem that the heat exchange efficiency in the heated part is reduced.

  This problem is not limited to the external combustion engine in which the heated portion is expanded in a disk shape, but also the external combustion in which the heated portion is expanded in a disk shape other than the disk (for example, a polygonal disk shape). It occurs in the same way in institutions.

  An object of this invention is to improve the heat exchange efficiency in a to-be-heated part in view of the said point.

In order to achieve the above object, in the invention described in claim 1, a tubular container (11) in which a working medium (12) is encapsulated so as to be flowable in a liquid state;
A heater (13) for heating and vaporizing a part of the liquid working medium (12) in the container (11);
A cooler (14) for cooling and liquefying the vapor of the working medium (12) heated and vaporized by the heater (13);
An output unit (15) for converting the displacement of the liquid portion of the working medium (12) caused by the volume fluctuation of the working medium (12) into mechanical energy and outputting the mechanical energy;
The diameter of the container (11) is expanded in a disk shape in the heated portion (11a) where the working medium (12) is vaporized,
In the heated part (11a), a sintered body (21) having a fine flow path through which the working medium (12) flows is disposed so as to be thermally conductive,
In the sintered body (21), a cavity (21a) that constitutes a flow path that is larger than the fine flow path is formed so as to be polymerized at the center of the heated portion (11a) .
Further, the connecting portion between the expanded diameter portion expanded in the container (11) and the tubular tube portion is the central portion of the expanded diameter portion, and the cavity (21a) is provided in the central portion of the expanded diameter portion. It is characterized by that.

  According to this, the working medium (12) flows through the cavity (21a) of the sintered body (21) at the center of the heated part (11a), and the working medium (12) flows at the outer peripheral part of the heated part (11a). It will flow through the fine flow path of the sintered body (21).

  For this reason, since it can suppress that the flow-path cross-sectional area of a working medium (12) increases as it goes to a peripheral part from the center part of a to-be-heated part (11a), the center part and outer peripheral part of a to-be-heated part (11a) Thus, the occurrence of a temperature difference can be suppressed, and as a result, the efficiency of heat exchange in the heated portion (11a) can be improved.

  The invention according to claim 2 is characterized in that, in the external combustion engine according to claim 1, the planar shape of the cavity (21a) is a star shape surrounded by three or more smooth curves. .

  Thereby, since the surface area of the site | part which faces a cavity (21a) among sintered compacts (21) can be increased, the contact of the working medium (12) in a cavity (21a) and a sintered compact (21) The area can be increased. For this reason, the efficiency of the heat exchange in a to-be-heated part (11a) can be improved more.

  Specifically, as in the invention according to claim 3, in the external combustion engine according to claim 2, a smooth curve may be formed into an arc.

  In the invention according to claim 4, in the external combustion engine according to claim 1, the planar shape of the cavity (21a) is a shape formed by arranging one or more triangles around a circle. To do.

  Thereby, since the surface area of the site | part which faces a cavity (21a) among sintered compacts (21) can be increased, the contact of the working medium (12) in a cavity (21a) and a sintered compact (21) The area can be increased. For this reason, the efficiency of the heat exchange in a to-be-heated part (11a) can be improved more.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram showing a schematic configuration of a power generation apparatus including an external combustion engine 10 and a generator 1 according to the present invention. The up arrow in FIG. 1 indicates the top and bottom direction, and the down arrow indicates the bottom and top direction.

  As shown in FIG. 1, an external combustion engine 10 of this embodiment is for driving a generator 1 that generates an electromotive force by oscillating and moving a mover 2 in which a permanent magnet is embedded. (In this embodiment, water) 12 in which liquid 12 is encapsulated so as to be flowable in a liquid state, a heater 13 that heats part of the working medium 12 in the container 11 to generate vapor of the working medium 12, and heating And a cooler 14 for cooling the vapor of the working medium 12 generated by the vessel 13.

  In the present embodiment, a high temperature gas is used as the heat source of the heater 13. In addition, cooling water circulates in the cooler 14 of the present embodiment. Although not shown, a radiator that dissipates heat taken from the steam of the working medium 12 by the cooling water is disposed in the circulating circuit of the cooling water.

  The container 11, which is a tubular pressure vessel, has a substantially U shape as a whole, and is disposed such that the bent portion is positioned at the lowermost portion and both end portions extend upward in the vertical direction. A heater 13 is disposed at one end of the container 11. A cooler 14 is disposed at a site on one end side of the container 11 and below the heater 13.

  In this example, since the working medium 12 is water, the container 11 is made of stainless steel. It is good also considering the to-be-heated part 11a which contacts the heater 13 among the containers 11, and the to-be-cooled part 11b which contacts the cooler 14 as the product made from copper or aluminum excellent in thermal conductivity.

  An output unit 15 that converts the displacement of the liquid portion of the working medium 12 into mechanical energy and outputs it is disposed at the other end of the container 11 (the end opposite to the heated portion 11a). The output unit 15 includes a piston 16 that is displaced by receiving pressure from a liquid portion (liquid piston) of the working medium 12, and a cylinder unit 17 that slidably supports the piston 16.

  The piston 16 is connected to the shaft 2a of the mover 2, and an elastic means for generating an elastic force that presses the mover 2 toward the piston 16 is formed on the opposite side of the piston 16 across the mover 2. A spring 18 is provided.

  2 is an enlarged cross-sectional view of the heated portion 11a, and FIG. 3 is a cross-sectional view taken along the line AA of FIG. The container 11 is expanded in a disk shape in the heated portion 11a. A sintered body 21 formed of a powder having excellent thermal conductivity (copper powder in this example) is disposed in contact with the bottom surface in the heated portion 11a so as to conduct heat. The sintered body 21 is formed in a disk shape having an outer diameter slightly smaller than the inner diameter of the heated portion 11a, and is disposed coaxially with the heated portion 11a.

  The fine space formed inside the sintered body 21 constitutes a fine flow path through which the working medium 12 flows. At the center of the sintered body 21, a cavity 21a that forms a flow path that is larger than the fine flow path is formed so as to overlap with the center of the heated portion 11a. In this example, the planar shape of the cavity 21a (the shape shown in FIG. 3) is a substantially three-star shape surrounded by three arcs.

  On the upper surface of the sintered body 21, a partition plate 22 that divides the internal space of the heated portion 11 a up and down is disposed. The partition plate 22 is formed in a disc shape having an outer diameter slightly smaller than the inner diameter of the heated portion 11a, and is arranged coaxially with the heated portion 11a. Accordingly, a communication path 23 that connects the upper and lower spaces partitioned by the partition plate 22 is formed on the outer peripheral side of the partition plate 22.

  The space above the partition plate 22 in the heated part 11a constitutes a gas sealing part 24 in which a predetermined volume of gas is sealed. The gas sealing portion 24 is a space necessary for the working medium 12 heated by the heater 13 to vaporize. The gas sealed in the gas sealing part 24 may be air, for example, or pure vapor of the working medium 12.

  Next, the operation in the above configuration will be described. When the heater 13 and the cooler 14 are operated, first, the working medium (water) 12 in the heated portion 11a is heated and vaporized by the heater 13, and the high-temperature / high-pressure working medium 12 is heated in the heated portion 11a. The vapor is accumulated, and the liquid level of the working medium 12 on one end side (the heated portion 11a side) of the container 11 is pushed down. Then, the liquid part of the working medium 12 enclosed in the container 11 is displaced from one end side to the other end side of the container 11 to push up the piston 16 on the generator 1 side and compress the spring 18.

  When the liquid level of the working medium 12 at one end of the container 11 falls to the cooled part 11b and the vapor of the working medium 12 enters the cooled part 11b, the vapor of the working medium 12 is cooled and liquefied by the cooler 14. Therefore, the force that pushes down the liquid level of the working medium 12 disappears, and the liquid level of the working medium 12 rises on one end side of the container 11. As a result, the piston 16 on the generator 1 side that is once pushed up by the expansion of the vapor of the working medium 12 is lowered by the elastic force of the spring 18.

  Such an operation is repeatedly executed until the operations of the heater 13 and the cooler 14 are stopped, during which the liquid portion of the working medium 12 in the container 11 is periodically displaced as a liquid piston (so-called self-excited vibration). Thus, the mover 2 of the generator 1 is moved up and down.

  Next, the behavior of the working medium 12 in the heated part 11a will be described in detail. When the vapor of the working medium 12 is cooled and liquefied by the cooler 14 and the liquid level of the working medium 12 on one end side of the container 11 rises, the working medium 12 in the liquid state is partitioned as indicated by an arrow a in FIG. It collides with the plate 22. Then, the working medium 12 in the liquid state colliding with the partition plate 22 changes its flow direction by approximately 90 degrees as indicated by the arrow b in FIG. Enter the flow path.

  The working medium 12 in the liquid state entering the fine flow path in the sintered body 21 is heated and vaporized in the process of flowing from the center of the heated portion 11a toward the outer periphery as indicated by the arrows in FIG. . Then, the vapor of the vaporized working medium 12 flows into the gas enclosure 24 through the communication path 23 located on the outer peripheral side of the sintered body 21.

  According to the present embodiment, the liquid working medium 12 collides with the partition plate 22 and the liquid working medium 12 in the heated part 11a is agitated to generate a turbulent flow. Therefore, heat exchange in the heated part 11a Efficiency can be improved.

  Furthermore, according to this embodiment, the working medium 12 flows through the cavity 21a of the sintered body 21 at the center of the heated portion 11a, and the working medium 12 passes through the fine flow path of the sintered body 21 at the outer peripheral portion of the heated portion 11a. Will flow.

  For this reason, since it can suppress that the flow-path cross-sectional area of the working medium 12 increases as it goes to the outer peripheral part from the center part of the to-be-heated part 11a, a temperature difference arises by the center part and outer peripheral part of the to-be-heated part 11a. As a result, the efficiency of heat exchange in the heated portion 11a can be further improved.

  And since the planar shape of the cavity 21a of the sintered compact 21 is made into the substantially three star shape enclosed by three circular arcs, the surface area of the site | part which faces the cavity 21a among the sintered compacts 21 is increased. Therefore, the contact area between the working medium 12 and the sintered body 21 in the cavity 21a can be increased. For this reason, the efficiency of the heat exchange in the to-be-heated part 11a can be improved further.

(Second Embodiment)
In the first embodiment, the planar shape of the cavity 21a of the sintered body 21 is substantially a three-star shape, but in the second embodiment, the planar shape of the cavity 21a is substantially as shown in FIG. It has a four-star shape.

  In this example, the substantially four-star shape of the cavity 21a is formed by arranging four isosceles triangles around a circle. Also in this embodiment, the same effect as the first embodiment can be obtained.

(Other embodiments)
(1) The above embodiments are merely examples of the planar shape of the cavity 21a, and the planar shape of the cavity 21a can be variously changed without being limited thereto.

  For example, in the first embodiment, the planar shape of the cavity 21a may be a star shape surrounded by four or more arcs, or a star surrounded by a curve other than the arc, for example, a smooth curve whose curvature changes. You may make it a shape.

  In the second embodiment, the planar shape of the cavity 21a may be a shape formed by arranging four or more isosceles triangles around the circle, or a triangle other than the isosceles triangle may be placed around the circle. You may make it the shape formed by arrangement | positioning.

  (2) In each of the above-described embodiments, the heated portion 11a and the sintered body 21 are formed in a disk shape, but the heated portion 11a and the sintered body 21 are not limited to this and are formed in a disk shape other than the disk ( For example, a polygonal disk shape may be used.

  (3) In each of the above embodiments, the heater 13 and the container 11 are formed separately. However, the heated portion 11a of the heater 13 and the container 11 may be integrally formed.

  (4) In each of the above embodiments, a high-temperature gas is used as a heat source for the heater 13, but the heater 13 may be configured by an electric heater.

  (5) In each of the above embodiments, the case where the present invention is applied to the drive source of the power generation apparatus has been described, but the external combustion engine of the present invention can also be used as a drive source other than the power generation apparatus.

It is a schematic block diagram of the electric power generating apparatus which shows 1st Embodiment of this invention. It is an expanded sectional view of the to-be-heated part in FIG. It is AA sectional drawing of FIG. It is an expanded sectional view of the heated part in a 2nd embodiment.

Explanation of symbols

11a Heated part 13 Heater 21 Sintered body 21a Cavity

Claims (4)

A tubular container (11) in which a working medium (12) is encapsulated so as to be able to flow in a liquid state;
A heater (13) for heating and evaporating a part of the liquid working medium (12) in the container (11);
A cooler (14) for cooling and liquefying the vapor of the working medium (12) heated and vaporized by the heater (13);
An output unit (15) for converting the displacement of the liquid part of the working medium (12) caused by the volume fluctuation of the vapor of the working medium (12) into mechanical energy and outputting it.
The container (11) is expanded in a disk shape in a heated portion (11a) where the working medium (12) is vaporized,
In the heated part (11a), a sintered body (21) having a fine flow channel through which the working medium (12) flows is disposed so as to be thermally conductive,
In the sintered body (21), a cavity (21a) constituting a flow path enlarged from the fine flow path is formed so as to be polymerized in a central portion of the heated portion (11a) ,
Furthermore, the connection part of the enlarged diameter part expanded in the said container (11) and the tubular pipe part is a center part of the said enlarged diameter part, Comprising: The said cavity (in the center part of the said enlarged diameter part) An external combustion engine characterized in that there is 21a) .   2. The external combustion engine according to claim 1, wherein the planar shape of the cavity (21 a) is a star shape surrounded by three or more smooth curves.   The external combustion engine according to claim 2, wherein the smooth curve is an arc.   The external combustion engine according to claim 1, wherein the planar shape of the cavity (21a) is a shape formed by arranging one or more triangles around a circle.

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