JP2007085641A - Heat exchanger for stirling engine, and stirling engine using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger for a Stirling engine providing smooth and stable heat exchange with a heat transfer head. <P>SOLUTION: In the Stirling engine 1, working gas is moved between a compression space 45 and an expansion space 46 by a piston 12 and a displacer 13. A high temperature side internal heat exchanger 42 and a low temperature side internal heat exchanger 43 arranged between the compression space 45 and the expansion space 46, and transferring heat exchanged with the working gas to a high temperature side heat transfer head 40 and a low temperature side heat transfer head 42 are both composed of the heat exchanger 100. The heat exchanger 100 is formed with a multiplicity of fins 102 extending in a center direction of a ring, in an inner face of a ring like base 101. A retaining ring 110 is pressed in a cylindrical space formed between tips of the fins 102. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat exchanger for a Stirling engine and a Stirling engine using the same.

  The Stirling engine is attracting attention as a heat engine that does not cause destruction of the ozone layer because helium, hydrogen, nitrogen or the like is used as a working gas instead of Freon. In a Stirling engine used as a refrigerator, a piston is reciprocated by a power source such as a linear motor, and a displacer is synchronously reciprocated with a predetermined phase difference with respect to the piston. The piston and displacer move working gas back and forth between the compression space and the expansion space. The working gas temperature rises in the compression space, and the working gas temperature falls in the expansion space. If the heat in the compression space (high temperature space) is dissipated through the high temperature heat transfer head to achieve isothermal compression change, and the external heat is absorbed into the expansion space (low temperature space) through the low temperature heat transfer head, the isothermal expansion change is realized. A reverse Stirling cycle is formed.

  In order to transfer heat from the compression space (high temperature space) to the high temperature heat transfer head and to absorb external heat to the expansion space (low temperature space) through the low temperature heat transfer head, Each has a heat exchanger. Increasing the heat exchange efficiency and heat transfer efficiency of such a heat exchanger has been a concern in the art.

Patent Documents 1 and 2 describe heat exchangers made of corrugated fins. Corrugated fins are used because they have a wide heat transfer area (the area of the portion in contact with the working gas). The top of the corrugated fin is pressed against the inner peripheral surface of the tubular heat transfer head, and heat is transferred between the corrugated fin and the heat transfer head through a linear contact point. Patent Literature 3 discloses a skive heat radiating member which is an element technology of a heat exchanger. Although what was disclosed by patent document 4 is not a heat exchanger but a regenerator, the fin is formed radially by extrusion molding.
JP 2002-81774 A (page 3-5, FIG. 1-8) JP 2001-91075 A (Page 3-5, FIG. 1-5) JP 2001-326308 A (page 3-5, FIG. 1-5) JP 2000-28214 A (page 4-5, FIG. 1-6)

  When a heat exchanger composed of corrugated fins is combined with a heat transfer head, it is required that the top of the corrugated fin ridge does not leak and adheres closely to the inner peripheral surface of the heat transfer head. To that end, it is necessary to draw a perfect circle on the top of the corrugated fin ridge, but it is difficult to accurately finish the geometric shape of the corrugated fin, and the inner peripheral surface of the heat transfer head Often there was a top that did not touch the surface. When the situation where the portion to be contacted with the heat transfer head does not contact occurs, naturally, heat transfer between the heat exchanger and the heat transfer head is hindered, and the performance of the Stirling engine is deteriorated. In order not to fall into such a situation, the top of the corrugated fin ridge and the inner peripheral surface of the heat transfer head are brazed or bonded with an adhesive so that no gap is created between them. Although practiced, it leads to an increase in material costs and processing costs, which is undesirable.

  The present invention has been made in view of the above points, and provides a heat exchanger for a Stirling engine having a novel structure in which heat exchange with a heat transfer head is smooth and stable, and such a heat exchanger. The purpose is to provide a high performance Stirling engine.

  (1) In order to achieve the above object, the present invention provides a heat exchanger for a Stirling engine that transfers heat transferred between a compression space and a working gas that travels between expansion spaces to a heat transfer head. A large number of fins extending toward the center of the ring are formed on the inner surface.

  According to this configuration, heat transfer between the heat transfer head is not performed through the linear portion of the top of the ridge like the corrugated fin, but is performed through the planar portion of the outer periphery of the ring-shaped base. However, heat transfer is stable and the amount of heat transferred can be increased.

  (2) Further, the present invention is characterized in that, in the heat exchanger for a Stirling engine having the above-described configuration, the base and the fin are integrally extruded.

  According to this structure, since there is no boundary part which inhibits heat transfer between a base and a fin, favorable heat transfer can be implement | achieved.

  (3) Further, in the heat exchanger for a Stirling engine having the above-described configuration, the ring-shaped base is formed by rolling a flat plate-like material having a large number of fins with the fins inward. Yes.

  According to this configuration, the flat material with the fins standing up is rounded to form the heat exchanger. Therefore, various methods can be used to stand up the fins, and manufacturing is easy. Further, the diameter of the ring-shaped base can be freely adjusted by changing the length of the flat plate material.

  (4) The present invention is also characterized in that in the heat exchanger for a Stirling engine configured as described above, the ring base has at least one slit having a vector component in the ring axis direction.

  According to this configuration, if the force is applied to the ring-shaped base to reduce the width of the slit, the diameter of the base itself becomes smaller.In that state, the ring-shaped base is inserted into the heat transfer head and then the force is relaxed. The outer peripheral surface of the ring-shaped base can be closely adhered to the inner peripheral surface of the heat transfer head. Even when a sudden temperature difference occurs between the heat exchanger and the heat transfer head, the ring-shaped base immediately follows the expansion or contraction of the heat transfer head and maintains surface contact with the elasticity provided by the presence of the slit. Can do.

  (5) Moreover, this invention is a heat exchanger for Stirling engines of the said structure, The said slit divides the said ring-shaped base, It is characterized by the above-mentioned.

  According to this configuration, since the dimensional difference between the inner circumference of the heat transfer head and the outer circumference of the base can be absorbed by the expansion and contraction of the slit width, the dimensional accuracy does not have to be pursued so strictly when manufacturing the heat exchanger. Also, since the ring shape of the base is easily bent, it is easy to insert it into the heat transfer head.

  (6) Moreover, this invention is a heat exchanger for Stirling engines of the said structure, The said slit is provided with the bridge part which connects both bank parts.

  According to this configuration, even if the heat exchanger is not supported by a hand, the slit does not open too much, and the ring-shaped base is kept at a certain diameter or less, so that handling is easy.

  (7) Further, according to the present invention, in the heat exchanger for a Stirling engine having the above-described configuration, the ring-shaped base has a diameter-reducing groove having a vector component in a ring axis direction in at least one place.

  According to this configuration, if a force is applied to the ring-shaped base to reduce the width of the diameter-reducing groove, the diameter of the ring-shaped base itself is reduced. By loosening, the outer peripheral surface of the ring-shaped base can be brought into close contact with the inner peripheral surface of the heat transfer head.

  (8) Further, in the heat exchanger for a Stirling engine having the above-described configuration, the fin has a cross-sectional shape viewed from an end surface direction and is tapered toward a center direction of the ring-shaped base. Yes.

  According to this configuration, the heat transfer of the fins increases in resistance from the point where the fin cross-sectional area gradually decreases toward the center of the heat exchanger, and the fin cross-sectional area gradually increases toward the outer periphery of the heat exchanger. The resistance becomes small from where you do. Accordingly, heat easily flows toward the outer periphery of the heat exchanger, and the amount of heat exchanged with the heat transfer head increases.

  (9) Further, the present invention is characterized in that in the heat exchanger for a Stirling engine having the above-described configuration, a retaining ring is press-fitted into a cylindrical space formed between the tips of the fins.

  According to this configuration, since the retaining ring presses the heat exchanger in the outer circumferential direction and strongly presses the fin, the outer circumferential surface of the heat exchanger is pressed against the inner circumferential surface of the heat transfer head, the contact state is stabilized, and the heat is Transfer efficiency is improved.

  (10) Further, in the heat exchanger for a Stirling engine having the above-described configuration, the present invention is characterized in that the fin has a curved cross-sectional shape viewed from the end surface direction.

  According to this configuration, since the fin comes into contact with the member inserted in the center of the heat exchanger by elasticity due to bending, it is difficult to cause a variation in that some fins reach the member and some do not reach. When the member is a retaining ring, the ring base is pressed against the inner circumferential surface of the heat transfer head over the entire circumference by the reaction force of the force exerted on the retaining ring by the fin, and the contact state is stabilized, improving the heat transfer efficiency. .

  (11) Further, the present invention is a Stirling engine equipped with any of the heat exchangers described above.

  According to this configuration, the capacity or operating efficiency of the Stirling engine can be improved by using a heat exchanger having excellent heat transfer performance.

  According to the present invention, it is possible to obtain a heat exchanger for a Stirling engine that has a large heat transfer area and is in surface contact with the inner peripheral surface of the heat transfer head and can stably transfer heat.

  First, the structure of a Stirling engine that is a target for use of the heat exchanger of the present invention will be described with reference to FIG. FIG. 1 is a sectional view of a Stirling engine.

  The Stirling engine 1 is a free piston type used as a refrigerator, and the cylinders 10 and 11 are the center of the assembly. The axes of the cylinders 10 and 11 are aligned on the same straight line. A piston 12 is inserted into the cylinder 10, and a displacer 13 is inserted into the cylinder 11. The piston 12 and the displacer 13 reciprocate without contacting the inner walls of the cylinders 10 and 11 by the mechanism of the gas bearing during operation of the Stirling engine 1. The piston 12 and the displacer 13 move with a predetermined phase difference.

  A cup-shaped magnet holder 14 is fixed to one end of the piston 12. A displacer shaft 15 protrudes from one end of the displacer 13. The displacer shaft 15 passes through the piston 12 and the magnet holder 14 so as to freely slide in the axial direction.

  The cylinder 10 holds the linear motor 20 outside the portion corresponding to the operation region of the piston 12. The linear motor 20 includes an outer yoke 22 having a coil 21, an inner yoke 23 provided so as to be in contact with the outer peripheral surface of the cylinder 10, and a ring shape inserted into an annular space between the outer yoke 22 and the inner yoke 23. , A tube 25 surrounding the outer yoke 22, an outer yoke 22, an inner yoke 23, and synthetic resin end brackets 26 and 27 that hold the tube 25 in a predetermined positional relationship. The magnet 24 is fixed to the magnet holder 14.

  The central portion of the spring 30 is fixed to the hub portion of the magnet holder 14. The center portion of the spring 31 is fixed to the displacer shaft 15. The outer peripheral portions of the springs 30 and 31 are fixed to the end bracket 27. A spacer 32 is disposed between the outer peripheries of the springs 30 and 31, whereby the springs 30 and 31 maintain a certain distance. The springs 30 and 31 are disc-shaped materials with spiral cuts and resonate the displacer 13 with a predetermined phase difference (generally about 90 ° phase difference) with respect to the piston 12. Play a role.

  A high temperature side heat transfer head 40 and a low temperature side heat transfer head 41 are arranged outside the portion of the cylinder 11 corresponding to the operating region of the displacer 13. The high temperature side heat transfer head 40 has a ring shape, and the low temperature side heat transfer head 41 has a cap shape, both of which are made of a metal having good heat conductivity such as copper or copper alloy. A ring-shaped high-temperature side internal heat exchanger 42 is mounted on the inner peripheral surface of the high-temperature side heat transfer head 40, and a ring-shaped low-temperature side internal heat exchanger 43 is also mounted on the inner peripheral surface of the low-temperature side heat transfer head 41. Installed. Each of the high temperature side internal heat exchanger 42 and the low temperature side internal heat exchanger 43 has air permeability, and transfers the heat of the working gas passing through the inside to the high temperature side heat transfer head 40 and the low temperature side heat transfer head 41. The structure of the high temperature side internal heat exchanger 42 and the low temperature side internal heat exchanger 43 will be described in detail later.

  The high temperature side heat transfer head 40 and the low temperature side heat transfer head 41 are thus supported outside the cylinder 11 with the high temperature side internal heat exchanger 42 and the low temperature side internal heat exchanger 43 interposed therebetween. The cylinder 10 and the pressure vessel 50 are connected to the high temperature side heat transfer head 40.

  An annular space surrounded by the high temperature side heat transfer head 40, the cylinders 10 and 11, the piston 12, the displacer 13, the displacer shaft 15, and the high temperature side internal heat exchanger 42 becomes a compression space 45. A space surrounded by the low temperature side heat transfer head 41, the cylinder 11, the displacer 13, and the low temperature side internal heat exchanger 43 becomes an expansion space 46.

  A regenerator 70 is disposed between the high temperature side internal heat exchanger 42 and the low temperature side internal heat exchanger 43. A regenerator 47 is disposed between the internal heat exchangers 42 and 43. The regenerator 47 is formed by filling a container with a filler (matrix) such as a wire mesh, or winding a thin metal plate or a synthetic resin film in a coil shape, and has a gap through which a working gas passes. A regenerator tube 48 wraps outside the regenerator 47. The regenerator tube 48 forms an airtight passage between the heat transfer heads 40 and 41. The regenerator tube 48 can be formed of stainless steel, for example.

  A cylindrical pressure vessel covering the linear motor 20, the cylinder 10, and the piston 12 forms the body portion 50. The interior of the body part 50 is a back pressure space 51.

  The structure of the body part 50 is as follows. That is, the body part 50 is divided into two parts: a ring-like part 52 joined to the high-temperature side heat transfer head 40 and a cap-like part 53 joined to the ring-like part 52. Both the ring-shaped part 52 and the cap-shaped part 53 are made of stainless steel. One end of the ring-shaped portion 52 is narrowed to a taper shape and brazed to the high temperature side heat transfer head 40. The cap-shaped part 53 has a structure in which an end plate 53a is welded to the inner surface of the pipe.

  Flange-shaped portions 54 and 55 are provided at the other end of the ring-shaped portion 52 and the open end of the cap-shaped portion 53 facing the ring-shaped portion 52. The flange-shaped portions 54 and 55 are both formed by welding a stainless steel ring to the ring-shaped portion 52 and the cap-shaped portion 53. Finally, the flange-shaped portions 54 and 55 are welded and sealed. The body part 50 in a state is formed.

  The body portion 50 is provided with a terminal portion 28 for supplying power to the linear motor 20 and a pipe 50a for enclosing a working gas therein. These are all provided so as to protrude in the radial direction from the outer peripheral surface of the cap-shaped portion 53.

  A dynamic vibration absorber 60 is attached to the body portion 50. The dynamic vibration absorber 60 includes a base 61 fixed to the body portion 50, a plate-like spring 62 supported by the base 61, and a balance weight 63 supported by the spring 62.

  The Stirling engine 1 operates as follows. When an alternating current is supplied to the coil 21 of the linear motor 20, a magnetic field penetrating the magnet 24 is generated between the outer yoke 22 and the inner yoke 23, and the magnet 24 reciprocates in the axial direction. By supplying power with a frequency that matches the resonance frequency determined by the total mass of the piston system (piston 12, magnet holder 14, magnet 24, and spring 30) and the spring constant of the spring 30, the piston system has a smooth sine. Start wavy reciprocating motion.

  In the displacer system (the displacer 13, the displacer shaft 15, and the spring 31), the resonance frequency determined by the total mass and the spring constant of the spring 31 is set to resonate with the driving frequency of the piston 12.

  By the reciprocating motion of the piston 12, the compression space 45 is repeatedly compressed and expanded. As the pressure changes, the displacer 13 also reciprocates. At this time, a phase difference is generated between the displacer 13 and the piston 12 due to flow resistance between the compression space 45 and the expansion space 46. In this way, the displacer 13 having a free piston structure vibrates in synchronization with the piston 12 with a predetermined phase difference.

  By the above operation, an inverse Stirling cycle is formed between the compression space 45 and the expansion space 46. The working gas temperature rises in the compression space, and the working gas temperature falls in the expansion space 46. For this reason, the temperature of the compression space 45 rises and the temperature of the expansion space 46 falls.

  The working gas that travels between the compression space 45 and the expansion space 46 during operation passes through the high-temperature side internal heat exchanger 42 and the low-temperature side internal heat exchanger 43 to transfer the heat of the working gas to the high-temperature side internal heat exchanger. The temperature is transferred to the high temperature side heat transfer head 40 and the low temperature side heat transfer head 41 through 42 and the low temperature side internal heat exchanger 43. Since the working gas flowing into the regenerator 70 from the compression space 45 is high temperature, the high temperature side heat transfer head 40 is heated, and the high temperature side heat transfer head 40 becomes a worm head. Since the working gas flowing into the regenerator 70 from the expansion space 46 is low in temperature, the low-temperature side heat transfer head 41 is cooled, and the low-temperature side heat transfer head 41 becomes a cold head. The Stirling engine 1 functions as a refrigeration engine by dissipating heat from the high temperature side heat transfer head 40 to the atmosphere and lowering the temperature of the specific space with the low temperature side heat transfer head 41.

  The regenerator 70 functions to pass only the working gas without transferring the heat of the compression space 45 and the expansion space 46 to the counterpart space. The hot working gas that has entered the regenerator 70 from the compression space 45 via the high temperature side internal heat exchanger 42 gives its heat to the regenerator 70 when passing through the regenerator 70, and the expansion space with the temperature lowered. 46 flows in. The low-temperature working gas that has entered the regenerator 70 from the expansion space 46 through the low-temperature side internal heat exchanger 43 collects heat from the regenerator 70 when passing through the regenerator 70, and the compressed space in a state where the temperature has risen. 45. That is, the regenerator 70 serves as a heat storage means.

  When the piston 12 and the displacer 13 reciprocate and the working gas moves, the Stirling engine 1 is vibrated. The vibration suppressing device 60 suppresses this vibration.

  Next, the structure of the high temperature side internal heat exchanger 42 and the low temperature side internal heat exchanger 43 will be described with reference to FIG. The high temperature side internal heat exchanger 42 and the low temperature side heat exchanger 43 are both constituted by the heat exchanger 100.

  A first embodiment of the heat exchanger 100 is shown in FIGS. FIG. 2 shows a state in which it is fitted to a high temperature side heat transfer head 40 or a low temperature side heat transfer head 41 (hereinafter, the high temperature side heat transfer head 40 and the low temperature side heat transfer head 41 are simply referred to as “heat transfer head”). It is the figure which looked at the heat exchanger 100 from the end surface side, ie, making a line of sight correspond to the axis of a ring. FIG. 3 is a perspective view of the heat exchanger 100.

  The heat exchanger 100 has fins 102 that extend in parallel to the axis of the ring and toward the center of the ring at a constant pitch on the inner surface of a thin ring-shaped base 101 having an outer diameter substantially equal to the inner diameter of the heat transfer head. Many were formed. The base 101 and the fin 102 have the same width in the ring axis direction.

  The heat exchanger 100 can be manufactured by extruding a metal material into a long tube shape and cutting it into a predetermined length. Copper, copper alloy, aluminum, aluminum alloy or the like is used as the metal material. According to the extrusion molding, the base 101 and the fins 102 are integrated, and there is no boundary portion that hinders the transfer of heat between them, so that a good heat transfer can be realized.

  The molding method of the heat exchanger 100 is not limited to extrusion molding. Die-casting or cutting out from material blocks can also be used. These methods can also be formed so that the base 101 and the fins 102 are integrated.

  The heat exchanger 100 faces the inner peripheral surface of the heat transfer head on the outer peripheral surface of the base 101 and comes into surface contact. As described above, since heat is transferred to and from the heat transfer head through the planar portion of the outer periphery of the ring-shaped base 101, the heat transfer area is wide, the heat transfer is stable, and the amount of heat transferred is also increased. it can.

  Increasing the number of fins 102 increases the contact area with the working gas and can transfer a lot of heat, but the ventilation resistance increases in proportion to the number of fins 102. Therefore, the number of fins 102 is determined so that the contact area with the working gas and the ventilation resistance are balanced.

  The fin 102 has a cross-sectional shape viewed from the end surface direction and is tapered toward the center of the base 101. For this reason, the heat transfer of the fins 102 increases in resistance from the point where the cross-sectional area of the fins 102 gradually decreases toward the center of the heat exchanger 100, and the cross-sectional area of the fins 102 toward the outer peripheral direction of the heat exchanger 100. The resistance becomes small from the point where increases gradually. Accordingly, heat easily flows toward the outer periphery of the heat exchanger 100, and the amount of heat exchanged with the heat transfer head increases.

  A retaining ring 110 is press-fitted into a cylindrical space formed between the tips of the fins 102. Stainless steel is used for the retaining ring 110, but other metals may be used. Since the press-fitted retaining ring 110 presses the heat exchanger 100 in the outer peripheral direction and strongly presses the fins 102, the outer peripheral surface of the heat exchanger 100 is pressed against the inner peripheral surface of the heat transfer head, and the contact state is stabilized. Heat transfer efficiency is improved.

  The press-fitting of the retaining ring 110 may be performed after the heat exchanger 100 is inserted into the heat transfer head. The retaining ring 110 is first press-fitted into the heat exchanger 100, and then the heat exchanger 100 is moved into the heat transfer head. You may follow the procedure of press fitting.

  The outer diameter of the heat exchanger 100 may be made slightly larger than the inner diameter of the heat transfer head so that the fitting between the two becomes an interference fit. In this way, the retaining ring 110 can be omitted.

  The fin 102 has a curved cross-sectional shape viewed from the end surface direction. For this reason, when another member is inserted into the center of the heat exchanger 100, the fin 102 undergoes not only compression but also elastic deformation such that the radius of curvature is reduced. The tip of the fin 102 comes into contact with the inserted member with a cushioning property, and variations such as a fin that reaches the member and a fin that does not reach the member are unlikely to occur. When press-fitting the retaining ring 110, the base 101 is pressed against the inner peripheral surface of the heat transfer head over the entire circumference by the reaction force of the force exerted on the retaining ring 110 by the fin 102. Transfer efficiency is improved.

  A second embodiment of the heat exchanger 100 is shown in FIGS. FIG. 4 is a perspective view of a heat exchanger 100a according to the second embodiment. FIG. 5 is a view of the heat exchanger 100a fitted to the heat transfer head as viewed from the end face side. FIG. 6 is a plan development view.

  The heat exchanger 100 of the first embodiment has a ring shape from the beginning, but the heat exchanger 100a of the second embodiment is not. A ring-shaped base 101 is obtained by erecting a large number of fins 102 on a flat metal material 101p and rolling the metal material 101p with the fins 102 inside. FIG. 6 shows a planar metal material 101p having a large number of fins 102 standing in parallel to the ring axis. When this metal material 101p is rounded, a heat exchanger 100a shown in FIGS. 4 and 5 is obtained.

  According to this manufacturing method, since various methods such as the skive processing described in Patent Document 3 can be used for standing the fins 102, it is possible to select and manufacture a method advantageous in cost. . Further, the diameter of the base 101 can be freely adjusted by changing the length of the metal material 101p.

  When the metal material 101p with the fins 102 erected by skiving or the like is rolled into a ring shape by a conventionally known processing method such as wrapping around a cylindrical mold, the ring is formed by dividing the base 101 between the butt ends. A slit 103 extending parallel to the axis is formed. The slit 103 has a vector component in the ring axis direction as a matter of course in terms of geometric shape. Thus, in the heat exchanger 100a in which the slit 103 having the vector component in the ring axis direction is provided in the base 101, if the force is applied to the base 101 to reduce the width of the slit 103, the diameter of the base 101 itself is reduced. Therefore, the outer peripheral surface of the base 101 can be brought into close contact with the inner peripheral surface of the heat transfer head by loosening the force after the base 101 is inserted into the heat transfer head in this state. Further, even when a temperature difference suddenly occurs between the heat exchanger 100a and the heat transfer head, the base 101 immediately follows the expansion or contraction of the heat transfer head by the elasticity provided by the slit 103, and keeps the surface contact. be able to.

  The slit 103 divides the base 101, and the expansion and contraction of the width of the slit 103 can absorb the dimensional difference between the inner periphery of the heat transfer head and the outer periphery of the base 101. Therefore, in manufacturing the heat exchanger 100a, the dimensional accuracy is increased. You do n’t have to pursue that rigorously. Further, since the ring shape of the base 101 is easily bent, it is easy to insert it into the heat transfer head.

  In addition, it is also possible to obtain the shape of the heat exchanger 100a by extruding the metal material into a shape having the slit 103 without using the method of rounding the metal material 101p with the fins 102 standing upright.

  A third embodiment of the heat exchanger 100 is shown in FIG. FIG. 7 is a developed plan view of a heat exchanger 100b according to the third embodiment.

  In the second embodiment, the fins 102 are erected in parallel with the ring axis. The fins 102 of the third embodiment extend so as to intersect the ring axis at an angle θ. When the metal material 101p is rounded, the fin 102 forms a skew angle with respect to the ring axis.

  In the configuration of the third embodiment, even if the axial length of the entire heat exchanger is the same as that of the second embodiment, the length of the fins 102 is longer than that of the fins 102 of the second embodiment, and heat transfer accordingly. The area increases and heat transfer efficiency is improved.

  A fourth embodiment of the heat exchanger 100 is shown in FIG. FIG. 8 is a plan development view of a heat exchanger 100c according to the fourth embodiment.

  In the second embodiment, the fins 102 extend linearly in parallel with the ring axis. In the fourth embodiment, the fin 102 is bent into a “<” shape.

  In the configuration of the fourth embodiment, even if the axial length of the entire heat exchanger is the same as that of the second embodiment, the length of the fins 102 is longer than that of the fins 102 of the second embodiment, and heat transfer accordingly. The area increases and heat transfer efficiency is improved.

  A fifth embodiment of the heat exchanger 100 is shown in FIGS. FIG. 9 is a perspective view of a heat exchanger 100d according to the fifth embodiment, and FIG. 10 is a developed plan view of the heat exchanger 100d.

  The fifth embodiment differs from the second embodiment in the shape of the flat metal material 101p. That is, the metal material 101p of the second embodiment is rectangular, but the metal material 101p of the fifth embodiment is a parallelogram. When the metal material 101p is rounded, as shown in FIG. 10, the slit 103 has a skew angle with respect to the ring axis. The point that the slit 103 has a vector component in the ring axis direction, and the overall operation and effects are the same as in the second embodiment.

  A sixth embodiment of the heat exchanger 100 is shown in FIG. FIG. 11 is a developed plan view of a heat exchanger 100e according to the sixth embodiment.

  In the metal material 101p of the sixth embodiment, one end protrudes into a triangular convex portion 106, and the other end is recessed into a triangular concave portion 107. The slit formed between the convex part 106 and the concave part 107 bends in the shape of a "<". The point that the slit has a vector component in the ring axis direction, and the overall operation and effects are the same as in the second embodiment.

  A seventh embodiment of the heat exchanger 100 is shown in FIG. FIG. 12 is a plan development view of a heat exchanger 100f according to the seventh embodiment.

  In the seventh embodiment, two metal materials 101p each having a thick end and a thin end are arranged in such a manner that a thick end and a thin end are arranged to form a rectangle as a whole. When the two metal materials 101p combined in this way are rounded, a cylindrical heat exchanger 100f can be obtained.

  It is also possible to combine the fins 102 of the third and fourth embodiments with the metal material 101p of the fifth to seventh embodiments.

  An eighth embodiment of the heat exchanger 100 is shown in FIG. FIG. 13 is a cross-sectional view of a heat exchanger 100g according to the eighth embodiment.

  The entire heat exchanger 100g has a truncated cone shape, and the inner surface of the heat transfer head is also a conical surface having the same apex angle as that of the heat exchanger 100g. When the heat exchanger 100g is pushed into the heat transfer head, the outer peripheral surface of the heat exchanger 100g is in close contact with the inner peripheral surface of the heat transfer head, so that heat transfer efficiency can be improved. Further, since the heat exchanger 100g only enters the heat transfer head to a certain depth, the heat exchanger 100g is not pushed too much.

  A ninth embodiment of the heat exchanger 100 is shown in FIG. FIG. 14 is a cross-sectional view of a heat exchanger 100h according to the ninth embodiment.

  The heat exchanger 100h has a two-stage cylindrical shape in which a thin cylindrical portion and a thick cylindrical portion are connected. The inner surface of the heat transfer head that receives the heat exchanger 100h is also a two-stage cylindrical surface. When the heat exchanger 100h is inserted into the heat transfer head, the step between the thin portion and the thick portion serves as a stopper, and the heat exchanger 100h stops properly at a fixed insertion depth. For this reason, the relative position of the heat transfer head and the heat exchanger 100h can always be determined accurately.

  The heat exchanger 100g according to the eighth embodiment and the heat exchanger 100h according to the ninth embodiment can be formed by die-casting or cutting out from a material block. Moreover, it can also shape | mold by the method of rounding the flat metal raw material 101p which erected the fin 102 like 2nd-7th embodiment. The shape of the fin 102 and the shape of the flat metal material 101p may be the same as those in the previous embodiments.

  A tenth embodiment of the heat exchanger 100 is shown in FIG. FIG. 15 is a perspective view of a heat exchanger 100i according to the tenth embodiment.

  The heat exchanger 100i according to the tenth embodiment is formed in a ring shape by extrusion as in the first embodiment, and the slit 103 is formed by electric discharge machining. The slit 103 extends parallel to the ring axis and has a vector component in the ring axis direction. At both end portions of the slit 103 in the length direction, narrow bridge portions 104 that connect both bank portions of the slit 103 are formed. Since the bridge portion 104 is easily bent, the heat exchanger 100b is press-fitted into the heat transfer head having a tight size to bend the bridge portion 104, whereby the outer periphery of the base 101 is placed on the inner peripheral surface of the heat transfer head. The surface can be closely attached.

  Since both bridge portions of the slit 103 are connected by the bridge portion 104, the slit 103 does not open too much without supporting the heat exchanger 100i by hand, and the base 101 is kept below a certain diameter. Therefore, it is easy to handle the heat exchanger 100i both in the case where it is put in a returnable box and delivered to the assembly plant, and in the case where it is press-fitted into the heat transfer head.

  An eleventh embodiment of the heat exchanger 100 is shown in FIG. FIG. 16 is a perspective view of a heat exchanger 100j according to the eleventh embodiment.

  The heat exchanger 100j of the eleventh embodiment includes the bridge portions 104 at both ends of the slit 103 extending in parallel with the ring axis as in the tenth embodiment, but the shape of the bridge portion 104 is the same as that of the tenth embodiment. Is different. That is, the bridge portion 104 of the heat exchanger 100j of the eleventh embodiment is not linear as in the tenth embodiment, but has a “<” shape when viewed from a direction perpendicular to the outer peripheral surface of the base 101. Presents. As a result, the bridge portion 104 is easily contracted or buckled.

  A twelfth embodiment of the heat exchanger 100 is shown in FIG. FIG. 17 is a perspective view of a heat exchanger 100k according to the twelfth embodiment.

  Similarly to the tenth embodiment, the heat exchanger 100k of the twelfth embodiment includes the bridge portions 104 at both ends of the slit 103 extending in parallel with the ring axis, and the shape of the bridge portion 104 is the same as that of the tenth embodiment. Is different. That is, the bridge portion 104 of the heat exchanger 100k according to the twelfth embodiment has an arcuate cross section that is concave toward the center of the base 101. This shape can be formed by forming the slit 103 having the bridge portion 104 by electric discharge machining and then pressing the bridge portion 104. As a result, the bridge portion 104 is easily contracted or buckled.

  A thirteenth embodiment of the heat exchanger 100 is shown in FIG. FIG. 18 is a perspective view of a heat exchanger 100l according to the thirteenth embodiment.

  In the heat exchanger 100l of the thirteenth embodiment, a diameter reducing groove 105 is formed in the base 101 in place of the slit. The diameter-reducing groove 105 extends parallel to the ring axis and has a vector component in the ring axis direction. The cross-sectional shape of the diameter reducing groove 105 is a triangle. In this way, in the heat exchanger 100l in which the diameter reducing groove 105 having the vector component in the ring axis direction is provided in the base 101, if the force is applied to the base 101 to reduce the width of the diameter reducing groove 105, the base 101 In this state, the base 101 is inserted into the heat transfer head and then the force is loosened, so that the outer peripheral surface of the base 101 can be brought into close contact with the inner peripheral surface of the heat transfer head.

  A fourteenth embodiment of the heat exchanger 100 is shown in FIG. FIG. 19 is a view of the heat exchanger 100m according to the fourteenth embodiment fitted to a heat transfer head and viewed from the end face side.

  The heat exchanger 100m according to the fourteenth embodiment has a plurality of diameter-reducing grooves 105 formed therein. In the figure, a total of four diameter-reducing grooves 105 are formed at intervals of 90 °, but the number is arbitrary.

  A fifteenth embodiment of the heat exchanger 100 is shown in FIG. FIG. 20 is a view of the heat exchanger 100n according to the fifteenth embodiment fitted to a heat transfer head and viewed from the end face side.

  The heat exchanger 100n of the fifteenth embodiment differs from the thirteenth and fourteenth embodiments in the shape of the diameter-reducing groove 105. That is, the diameter-reduction groove 105 of the heat exchanger 100n of the fifteenth embodiment has an arc-shaped cross section that is concave toward the center of the base 101, and its wall surface is thinner than the base 101, and its width is reduced. It has become easier.

  The diameter-reducing groove 105 of the thirteenth to fifteenth embodiments may have an angle so as to intersect the ring axis. When a plurality of diameter-reducing grooves 105 are formed on one base 101, the angles may be different for each groove, and the diameter-reduced grooves 105 having different angles may be arranged so as to intersect each other.

  The configuration of each of the above embodiments is not exclusive and can be duplicated. For example, the slits with bridge portions of the third to fifth embodiments can be added to the heat exchanger 100b of the second embodiment, or the diameter reducing grooves of the thirteenth to fifteenth embodiments can be added. It is possible to carry out overlapping with various other combinations.

  Although each embodiment of the present invention has been described above, various modifications can be made without departing from the spirit of the present invention.

  The present invention is applicable to all Stirling engines.

Cross section of Stirling engine End view of the heat exchanger according to the first embodiment The perspective view of the heat exchanger which concerns on 1st Embodiment. The perspective view of the heat exchanger which concerns on 2nd Embodiment. End view of heat exchanger according to the second embodiment Plane development view of a heat exchanger according to the second embodiment Plane development view of a heat exchanger according to the third embodiment Plane development view of a heat exchanger according to the fourth embodiment The perspective view of the heat exchanger which concerns on 5th Embodiment Plane development view of heat exchanger according to fifth embodiment Plane development view of heat exchanger according to sixth embodiment Plane development view of heat exchanger according to seventh embodiment Sectional drawing of the heat exchanger which concerns on 8th Embodiment Sectional drawing of the heat exchanger which concerns on 9th Embodiment The perspective view of the heat exchanger which concerns on 10th Embodiment The perspective view of the heat exchanger which concerns on 11th Embodiment The perspective view of the heat exchanger which concerns on 12th Embodiment The perspective view of the heat exchanger which concerns on 13th Embodiment End view of heat exchanger according to the fourteenth embodiment End view of heat exchanger according to the fifteenth embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stirling engine 12 Piston 13 Displacer 20 Linear motor 40 High temperature side heat transfer head 41 Low temperature side heat transfer head 42 High temperature side internal heat exchanger 43 Low temperature side internal heat exchanger 45 Compression space 46 Expansion space 100, 100a-100n Heat exchanger 101 Base 102 Fin 103 Slit 104 Bridge part 105 Reducing groove 110 Retaining ring

Claims (11)

In a heat exchanger for a Stirling engine that transfers heat transferred between the compression space and the working gas moving back and forth to the expansion space to the heat transfer head,
A heat exchanger for a Stirling engine, wherein a large number of fins extending toward the center of the ring are formed on the inner surface of the ring-shaped base.   The heat exchanger for a Stirling engine according to claim 1, wherein the base and the fin are integrally formed by extrusion.   The heat exchanger for a Stirling engine according to claim 1, wherein the ring-shaped base is formed by rolling a flat plate-like material having a large number of fins with the fins facing inward.   The Stirling engine heat exchanger according to any one of claims 1 to 3, wherein the ring-shaped base has at least one slit having a vector component in a ring axis direction.   The Stirling engine heat exchanger according to claim 4, wherein the slit divides the ring-shaped base.   The Stirling engine heat exchanger according to claim 4, wherein the slit includes a bridge portion that connects both bank portions.   The heat exchanger for a Stirling engine according to any one of claims 1 to 3, wherein the ring-shaped base has at least one reduced-diameter groove having a vector component in a ring axis direction.   8. The heat exchange for a Stirling engine according to claim 1, wherein a cross-sectional shape of the fin as viewed from an end surface direction is tapered toward a center direction of the ring-shaped base. 9. vessel.   The Stirling engine heat exchanger according to any one of claims 1 to 8, wherein a retaining ring is press-fitted into a cylindrical space formed between tips of the fins.   The heat exchanger for a Stirling engine according to any one of claims 1 to 9, wherein the fin has a curved cross-sectional shape as viewed from the end surface direction.   A Stirling engine comprising the heat exchanger according to any one of claims 1 to 10.

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