Heat exchanger for stirling engine, manufacturing method for heat exchanger and regenerator

Abstract

To provide a heat exchanger for a Stirling engine that improves heat exchange performance of a regenerator, a manufacturing method for the heat exchanger and the regenerator.SOLUTION: A heat exchanger 6 for a Stirling engine 1 includes a heater 67, a regenerator 69 and a cooler 68 connected in series in a flowing direction of work gas. An expansion chamber 21 and a compression chamber 22 are communicated via the heater 67, the regenerator 69 and the cooler 68. The regenerator 69 includes: a heat accumulation body 71 capable of accumulating heat of the work gas; and a casing 70 that surrounds the heat accumulation body 71. The heat accumulation body 71 and the casing 70 are continuously connected to each other and provided integrally.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present invention relates to a heat exchanger for a Stirling engine, a method for manufacturing the heat exchanger, and a regenerator. [Background technology]

[0002] In recent years, research and development has been conducted to contribute to energy efficiency so that more people can have access to affordable, reliable, sustainable and advanced energy.

[0003] A Stirling engine is known as a heat engine that converts thermal energy into power. A Stirling engine converts thermal energy into power by moving a working gas back and forth between an expansion chamber on the heater side and a compression chamber on the cooler side via a heater, a regenerator, and a cooler, and repeating the volumetric changes of the expansion chamber and the compression chamber (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-126185 Summary of the Invention [Problem to be solved by the invention]

[0005] In a Stirling engine, the output performance of the engine depends heavily on the performance of the heat exchanger. To realize a Stirling engine with excellent output performance, it has been desired to improve the heat exchange performance of the heat exchanger.

[0006] The present invention provides a heat exchanger for a Stirling engine having improved heat exchange performance of the regenerator, a method for manufacturing the heat exchanger, and the regenerator. [Means for solving the problem]

[0007] The present invention relates to A heat exchanger for a Stirling engine, comprising a heater, a regenerator, and a cooler connected in series in a flow direction of a working fluid, and an expansion chamber and a compression chamber communicated with each other via the heater, the regenerator, and the cooler, The regenerator comprises: A heat storage body capable of storing heat of the working fluid; A housing that surrounds the heat storage body, The heat storage body and the housing are continuously connected to each other and integrally provided.

[0008] The present invention also provides a method for producing a semiconductor device comprising the steps of: A method for manufacturing the heat exchanger, comprising the steps of: The heat storage body and the housing of the regenerator are integrally formed by additive manufacturing of metal powder.

[0009] The present invention also provides a method for producing a semiconductor device comprising the steps of: A regenerator in which a fluid flows through an internal space, A heat storage body capable of storing heat of the fluid; A housing that surrounds the heat storage body, The heat storage body and the housing are continuously connected to each other and integrally provided, The heat storage body is configured by a plurality of side elements that are continuously connected in a three-dimensional shape and integrally provided, Each side element has a plate shape in which the surface area projected area of ​​a face seen from a second direction intersecting with a first direction which is the flow direction of the working fluid is larger than the surface area projected area of ​​the face seen from the first direction. Effect of the Invention

[0010] According to the present invention, the heat exchange performance of the regenerator can be improved. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a Stirling engine 1 which is an example of a Stirling engine according to the present invention. [Diagram 2] 2 is a cross-sectional view showing the configuration of a main part of a heat exchanger 6. FIG. [Diagram 3]FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 6 is a diagram showing a schematic diagram of a working gas passage 671 and a heat source fluid passage 672 provided in a heater 67. FIG. [Diagram 5] 6 is a schematic cross-sectional view of a working gas passage 671 and a heat source fluid passage 672 of a heater 67 defined by a partition wall 60. FIG. [Figure 6] 1(a) is a diagram showing a spiral flow generating section 55 provided in a working gas flow passage 671 of a heater 67, and FIG. 1(b) is a diagram showing the working gas flow passage 671 viewed from the flow direction of the heat source fluid. [Figure 7] 10(a) is a diagram showing the flow (broken line) of the heat source fluid flowing through the heat source fluid introduction chamber 80, and FIG. 10(b) is a diagram showing the ceiling wall 27 as viewed from the expansion chamber 21 side. [Figure 8] 3 is a cross-sectional view taken along line VIII-VIII in FIG. 2. [Figure 9] 6 is a diagram showing a schematic diagram of a working gas passage 681 and a cooling fluid passage 682 provided in a cooler 68. FIG. [Figure 10] FIG. [Figure 11] 11 is a side view of the heat storage body 71 as seen from the direction of the white arrow in FIG. [Figure 12] 2 is a perspective view of a unit structure 72 of a heat storage body 71. FIG. [Figure 13] 1A and 1B show a side element 73 of a heat storage body 71 as viewed from a second direction (upper figure) and as viewed from a first direction (lower figure). [Figure 14] 13 is a top view of the regenerator 69 with the heat storage body 71 housed in the housing 70. FIG. [Figure 15] 13 is a side view of the regenerator 69 in a state in which the heat storage body 71 is housed in the housing 70. FIG. [Figure 16] 1 is a side view of a heat exchanger 6, a heat source fluid introduction chamber 80, and a heat source fluid discharge passage 51 which are integrally formed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A Stirling engine according to an embodiment of the present invention will be described below with reference to the accompanying drawings. In the following, a β-type Stirling engine will be described as an example of the Stirling engine.

[0013] [Stirling engine] 1, a Stirling engine 1 includes a cylinder 2 in which a working gas is sealed, a displacer piston 3 and a power piston 4 inserted in the cylinder 2, a piston crank mechanism 5 connected to the displacer piston 3 and the power piston 4, and a heat exchanger 6 that raises and lowers the temperature of the working gas in the cylinder 2. The working gas is, for example, high-pressure air, helium, or hydrogen.

[0014] The Stirling engine 1 is, for example, a hermetic type engine, and a generator 11 that extracts the shaft rotation output of the piston crank mechanism 5 as electric power is disposed inside the crankcase.

[0015] The cylinder 2 has a generally cylindrical shape with one end provided with a ceiling wall 27 and the other end open. For ease of explanation, the axial direction of the cylinder 2 will also be referred to as the up-down direction, and the ceiling wall 27 side in the axial direction will also be referred to as the upper side, and the open side will also be referred to as the lower side.

[0016] A displacer piston 3 is disposed on the upper side of the cylinder 2, and a power piston 4 is disposed on the lower side. An expansion chamber 21 in which the working gas has a high temperature is formed between the displacer piston 3 and a ceiling wall 27, and a compression chamber 22 in which the working gas has a low temperature is formed between the displacer piston 3 and the power piston 4. Hereinafter, the expansion chamber 21 and the compression chamber 22 in the cylinder 2 are also referred to as a working space 20.

[0017] The cylinder 2 has a first cylinder 23 located on the upper side and a second cylinder 24 located on the lower side and having the same diameter as the first cylinder 23, and the first cylinder 23 and the second cylinder 24 are coaxially connected by flange portions 25, 26 that they have.

[0018] A plurality of first communication parts 23a are provided on the outer peripheral surface of the upper side of the first cylinder 23, which communicate with a plurality of first inlet / outlet parts (inlet / outlet parts) 61a (described later) of the heat exchanger 6. The number of the first communication parts 23a is the same as that of the first inlet / outlet parts 61a. Each of the first communication parts 23a is formed in a slit shape having substantially the same shape as the corresponding first inlet / outlet part 61a, and is disposed opposite the corresponding first inlet / outlet part 61a. The plurality of first communication parts 23a serve as inlets and outlets to the expansion chamber 21.

[0019] A plurality of second communication portions 23b are provided on the outer peripheral surface of the lower side of the first cylinder 23, which communicate with a plurality of second inlet / outlet portions (inlet / outlet portions) 61b (described later) of the heat exchanger 6. The number of the second communication portions 23b provided is the same as that of the second inlet / outlet portions 61b. Each second communication portion 23b is formed in a slit shape having substantially the same shape as the corresponding second inlet / outlet portion 61b, and is disposed opposite the corresponding second inlet / outlet portion 61b. The second communication portion 23b serves as an inlet / outlet of the compression chamber 22.

[0020] The displacer piston 3 and the power piston 4 are arranged coaxially in the cylinder 2. The displacer piston 3 divides the space formed by the cylinder 2 and the power piston 4 into two in the vertical direction. In other words, the displacer piston 3 forms an expansion chamber 21 formed above the displacer piston 3 and a compression chamber 22 formed between the displacer piston 3 and the power piston 4. The internal space (i.e., the working space 20) of the expansion chamber 21 and the compression chamber 22 is connected to the internal space of the heat exchanger 6 via a plurality of first communication parts 23a and a plurality of second communication parts 23b, and has a pressure substantially equal to the internal pressure of the heat exchanger 6. In this way, the expansion chamber 21 and the compression chamber 22 are connected to each other via the heat exchanger 6, and the working gas repeatedly moves back and forth between the expansion chamber 21 and the compression chamber 22 through the heat exchanger 6 by the movement of the displacer piston 3 described later.

[0021] The displacer piston 3 and the power piston 4 are connected to the crankshaft 10 via different connecting rods 30, 40 so that the power piston 4 moves 90 degrees ahead of the displacer piston 3 and the power piston 4 moves 90 degrees ahead of the displacer piston 3 and the power piston 4 outputs a rotational force to the piston crank mechanism 5 via the connecting rod 40. The crankshaft 10 is connected to the output shaft 16 of the recoil starter 15 via a coupling 14.

[0022] The displacer piston 3 is used to move the working gas in the cylinder 2, and by moving the working gas in the cylinder 2, the volume ratio of the expansion chamber 21 and the compression chamber 22 is changed. For example, when a large amount of high-temperature working gas exists in the expansion chamber 21, the internal pressure of the cylinder 2 becomes high, and when a large amount of low-temperature working gas exists in the compression chamber 22, the internal pressure of the cylinder 2 becomes low. In accordance with the timing of this pressure fluctuation, the power piston 4 is pushed down from near the top dead center at high pressure, thereby obtaining an axial torque to be output to the piston crank mechanism 5, and at low pressure, the power piston 4 is pushed up by the piston crank mechanism 5, and by repeating this, a continuous torque can be obtained.

[0023] As described above, the Stirling engine 1 constitutes a Stirling cycle in which the working gas is moved between the expansion chamber 21 and the compression chamber 22 via the heat exchanger 6, and the volumetric changes of the expansion chamber 21 and the compression chamber 22 are repeated to convert heat and power.

[0024] [Heat exchanger] As shown in FIG. 2, the heat exchanger 6 is configured in a double cylindrical shape extending in the axial direction (i.e., the vertical direction) along the outer peripheral surface of the first cylinder 23, and has an inner peripheral wall 61 provided on the inner peripheral side and an outer peripheral wall 62 provided on the outer peripheral side.

[0025] The heat exchanger 6 includes a heater 67 provided on the expansion chamber 21 side and performing heat exchange between the working gas and a heat source fluid, a cooler 68 provided on the compression chamber 22 side and performing heat exchange between the working gas and a cooling fluid, and a regenerator 69 disposed between the heater 67 and the cooler 68 and capable of storing heat of the working gas. For example, the heat source fluid is a high-temperature gas (for example, high-temperature air), and the cooling fluid is a low-temperature liquid (for example, cooling water).

[0026] The heater 67 , the regenerator 69 , and the cooler 68 are disposed between the inner circumferential wall 61 and the outer circumferential wall 62 , and are connected in series in the axial direction of the cylinder 2 .

[0027] The heater 67, the regenerator 69, and the cooler 68 are provided with a communication passage 600 through which the working gas flows, communicating the expansion chamber 21 with the compression chamber 22. The communication passage 600 is composed of a plurality of working gas flow passages 671 of the heater 67, an internal space of the regenerator 69, and a working gas flow passage 681 of the cooler 68, which will be described later.

[0028] (heater) As shown in FIG. 3, the heater 67 has a plurality of first partitions 60a extending radially and spaced at a predetermined interval in the circumferential direction, and a plurality of second partitions 60b connecting opposing surfaces of the first partitions 60a and extending in the flow direction (i.e., the vertical direction) of the working gas and heat source fluid.

[0029] In the heater 67, working gas circulation layers 63 through which the working gas flows and heat source fluid circulation layers 64 through which the heat source fluid flows are alternately formed in the circumferential direction, separated by the first partition wall 60a. The heater 67 is a plate-type heat exchanger in which the working gas and the heat source fluid exchange heat through the first partition wall 60a. In this embodiment, since the heat source fluid has a higher temperature than the working gas, the heater 67 heats the working gas that flows in and out of the expansion chamber 21 through the first communication portion 23a of the first cylinder 23.

[0030] 2, the above-mentioned first inlet / outlet portion 61a is provided at the upper end of the inner circumferential wall 61 where the working gas flow layer 63 is located. The first inlet / outlet portion 61a is formed in a slit shape having substantially the same shape as the corresponding first communication portion 23a, and is disposed opposite the corresponding first communication portion 23a of the first cylinder 23. In the heat exchanger 6, the first inlet / outlet portion 61a serves as an inlet / outlet to the expansion chamber 21 of the cylinder 2.

[0031] The working gas flow layer 63 has an upper end 631 that is closed, and a lower end that is open and communicates with a regenerator 69. The working gas flowing through the working gas flow layer 63 reverses its flow direction once per rotation of the crankshaft 10 due to the movement of the displacer piston 3.

[0032] The heat source fluid circulation layer 64 has an open upper end and communicates with a heat source fluid introduction chamber 80. The heat source fluid introduction chamber 80 introduces heat source fluid supplied from the outside into the heat source fluid circulation layer 64. As a result, the heat source fluid is introduced from above into the heat source fluid circulation layer 64. The heat source fluid introduction chamber 80 will be described in detail later.

[0033] An outlet portion 62a is provided in the outer peripheral wall 62 at the position of the lower end of the heat source fluid circulation layer 64. The outlet portion 62a is formed in a slit shape and is disposed opposite the corresponding heat source fluid circulation layer 64, and guides the heat source fluid to a heat source fluid discharge path 51 provided on the radially outer side of the heat source fluid circulation layer 64. In addition, an abutment portion 641 is provided at the lower end of the heat source fluid circulation layer 64. The abutment portion 641 is provided along the lower end of the outlet portion 62a of the outer peripheral wall 62, and guides the heat source fluid to the outlet portion 62a.

[0034] The heat source fluid discharge path 51 is provided in approximately the center of the heat exchanger 6 in the vertical direction, and extends along the circumferential direction of the heat exchanger 6. The heat source fluid discharge path 51 is provided with a discharge portion 52, and the heat source fluid guided from each outlet portion 62a to the heat source fluid discharge path 51 is discharged from the discharge portion 52 to the outside of the heat exchanger 6.

[0035] The inner structures of the working gas circulation layer 63 and the heat source fluid circulation layer 64 will be described in more detail. The heater 67 has a plurality of working gas flow paths 671 provided in the working gas circulation layer 63 and through which the working gas flows, and a plurality of heat source fluid flow paths 672 provided in the heat source fluid circulation layer 64 and through which the heat source fluid flows. Each working gas flow path 671 and each heat source fluid flow path 672 are defined by a first partition wall 60a and a second partition wall 60b. The first partition wall 60a and the second partition wall 60b that define each flow path may be collectively referred to as partition wall 60.

[0036] 4 is a diagram showing a working gas flow passage 671 and a heat source fluid flow passage 672, and the partition wall 60 is not shown in FIG. The working gas flow passage 671 extends in the vertical direction, and an upper end portion thereof communicates with the expansion chamber 21 via a space 630 and a first inlet / outlet portion 61a described later, and a lower end portion thereof communicates with a regenerator 69. Each working gas flow layer 63 is provided with a plurality of working gas flow passages 671 arranged in parallel along the radial direction. When the working gas flows from the lower end to the upper end of the working gas flow passage 671, it flows counter to the heat source fluid, and when the working gas flows from the upper end to the lower end, it flows parallel to the heat source fluid.

[0037] The upper end of the working gas flow passage 671 is located at a position farther from the closed upper end 631 of the working gas flow layer 63, as the working gas flow passage 671 is located closer to the first inlet / outlet portion 61a (i.e., on the inner periphery side). That is, the working gas discharged from the working gas flow passage 671 located closer to the first inlet / outlet portion 61a is discharged at a position farther from the upper end 631 of the working gas flow layer 63.

[0038] In each working gas flow layer 63 of the heater 67, a space 630 formed by the upper end 631 and the upper ends of the working gas flow passages 671 is substantially triangular in side view. The space 630 is a portion where the flow of the working gas flowing out from the working gas flow passage 671 bends toward the first inlet / outlet portion 61a. The space 630 is shaped so that the flow passage cross section gradually expands from the outer periphery side toward the inner periphery side, so that the flow velocity at each position is equalized and pressure loss can be minimized. In addition, by setting the maximum area of ​​the first inlet / outlet portion 61a to be equal to the sum of the cross-sectional areas of the working gas flow passages 671, the pressure loss of the heat exchanger 6 including the first inlet / outlet portion 61a can be minimized.

[0039] FIG. 5 is a schematic diagram showing a plurality of working gas flow passages 671 provided in each working gas flow layer 63. As shown in FIG. 5, the plurality of working gas flow passages 671 are partitioned by a first partition wall 60a and a second partition wall 60b. In this case, the plurality of working gas flow passages 671 are partitioned by the second partition wall 60b so that the equivalent diameters of the working gas flow passages 671 are equal. By making the equivalent diameters of the working gas flow passages 671 equal, the pressure loss coefficients and heat transfer coefficients become equal, and the working gas flowing through each working gas flow passage 671 does not drift. By eliminating the drift of the working gas flowing through the working gas flow passage 671, the overall pressure loss is reduced and the heat transfer performance is improved.

[0040] 2, the heat source fluid passage 672 extends in the vertical direction of the heat exchanger 6, with its upper end communicating with the heat source fluid introduction chamber 80 and its lower end communicating with the heat source fluid discharge passage 51 via a space 640 and an outlet portion 62a, which will be described later. Each working gas distribution layer 63 is provided with a plurality of heat source fluid passages 672 arranged in parallel along the radial direction.

[0041] The lower end of the heat source fluid flow path 672 is located at a position farther from the abutment portion 641 as the heat source fluid flow path 672 is located closer to the outlet portion 62a (i.e., closer to the outer periphery). That is, the heat source fluid discharged from the heat source fluid flow path 672 located closer to the outlet portion 62a is discharged at a position farther from the abutment portion 641.

[0042] In each heat source fluid flow layer 64, a space 640 formed by the abutment portion 641 and the lower ends of the heat source fluid flow paths 672 has a substantially triangular shape in side view. The space 640 is a portion where the flow of the heat source fluid flowing out from the heat source fluid flow path 672 bends toward the outlet portion 62a. The space 640 has a shape in which the flow path cross section gradually expands from the inner periphery side toward the outer periphery side, so that the flow velocity at each position is equal and pressure loss can be minimized.

[0043] As indicated by the symbols in parentheses in FIG. 5, the multiple heat source fluid flow paths 672 provided in each heat source fluid flow layer 64 are also defined by the first partition wall 60a and the second partition wall 60b, similar to the working gas flow path 671.

[0044] In this embodiment, the thermal conductivity of the heat source fluid is smaller than that of the working gas, and the heat transfer coefficient when the heat source fluid flows through the heat source fluid passage 672 is smaller than the heat transfer coefficient when the working gas flows through the working gas passage 671. In other words, the thermal resistance due to heat transfer of the heat source fluid (hereinafter also simply referred to as the thermal resistance on the heat source fluid side) is large.

[0045] 6(a) and 6(b), a spiral flow generating section 55 that generates a spiral flow (solid arrow in FIG. 6(a)) along the flow direction of the heat source fluid (i.e., downward) is provided in the heat source fluid flow path 672. This generates a tornado-like vortex flow along the flow direction of the heat source fluid and agitates the heat source fluid flowing through the heat source fluid flow path 672, thereby reducing the thermal resistance on the heat source fluid side and improving the heat transfer performance between the working gas and the heat source fluid via the partition wall 60.

[0046] Specifically, the spiral flow generating section 55 is composed of a plurality of fins 56 erected from the partition wall 60. The plurality of fins 56 are arranged at a predetermined interval along the flow direction of the heat source fluid, and are arranged in a spiral shape around the central axis L1 of the flow path cross section of the heat source fluid flow path 672. In (a) and (b) of FIG. 6, the flow path cross section of the heat source fluid flow path 672 has a rectangular shape, and the plurality of fins 56 are arranged in a spiral shape at 90 degree intervals in the circumferential direction along the central axis L1. The shape of the flow path cross section of the heat source fluid flow path 672 is arbitrary. In addition, the angular interval of the plurality of fins 56 in the circumferential direction is not limited to 90 degrees, but may be arranged in a spiral shape at an angular interval of 30 degrees or more and 180 degrees or less in the circumferential direction.

[0047] Each fin 56 has a base end 56a connected to the partition wall 60. The base end 56a is connected to the partition wall 60 at a predetermined angle inclined with respect to a plane perpendicular to the central axis L1 so as to generate a spiral flow of the heat source fluid. Although the provision of the fins 56 increases the pressure loss of the heat source fluid flowing through the heat source fluid passage 672 compared to a case where the fins 56 are not provided, the degree of increase in pressure loss can be reduced by connecting each fin 56 to the partition wall 60 at a predetermined angle inclined. Furthermore, even if foreign matter enters the heat source fluid passage 672 together with the heat source fluid, the foreign matter is less likely to accumulate on the fins 56, so that clogging of the heat source fluid passage 672 can be suppressed.

[0048] The fins 56 adjacent to each other in the flow direction of the heat source fluid are provided at positions where they do not overlap in the flow direction. In other words, the downstream end 56b of the upstream fin 56 is provided to be located upstream of the upstream end 56c of the downstream fin 56. This can further reduce the degree of increase in pressure loss when the heat source fluid flows through the heat source fluid flow path 672. Furthermore, clogging of the heat source fluid flow path 672 due to the intrusion of foreign matter can be further suppressed.

[0049] 6(b), the heat source fluid flow path 672 has a through region 57 where no fins 56 are arranged, as viewed from the flow direction of the heat source fluid. In this embodiment, as viewed from the flow direction of the heat source fluid, a region including the central axis L1 of the heat source fluid flow path 672 becomes the through region 57. This makes it possible to further reduce the degree of increase in pressure loss when the heat source fluid flows through the heat source fluid flow path 672.

[0050] As described above, when the spiral flow generating part 55 is provided in the flow path, the heat transfer coefficient increases and the thermal resistance decreases. On the other hand, compared to when the spiral flow generating part 55 is not provided, the pressure loss of the fluid increases, which may affect the output performance of the Stirling engine 1. Therefore, it is preferable to determine whether or not to provide the spiral flow generating part 55 in the flow path, taking into consideration the balance between the effect of reducing the thermal resistance by providing the spiral flow generating part 55 in the flow path and the effect of increasing the pressure loss.

[0051] Of the working gas, heat source fluid, and cooling fluid flowing through the heat exchanger 6, the working gas and the cooling fluid have high thermal conductivity. In addition, the heat transfer coefficient when the working gas flows through the working gas passage 671 of the heater 67 and the working gas passage 681 of the cooler 68 described later, and the heat transfer coefficient when the cooling fluid flows through the cooling fluid passage 682 of the cooler 68 described later are both high. Therefore, the thermal resistance on the working gas side and the cooling fluid side is small. In this case, the effect of reducing the thermal resistance by providing the spiral flow generating unit 55 in the working gas passage 671 of the heater 67 and the working gas passage 681 and the cooling fluid passage 682 of the cooler 68 becomes relatively small. Therefore, in consideration of the effect of increasing the pressure loss, it is preferable not to provide the spiral flow generating unit 55 in the working gas passage 671 of the heater 67 and the working gas passage 681 and the cooling fluid passage 682 of the cooler 68.

[0052] On the other hand, as described above, the thermal resistance on the heat source fluid side is large, and the effect of reducing the thermal resistance is significant by providing the spiral flow generating part 55 in the heat source fluid flow path 672. Therefore, even taking into account the effect of increased pressure loss, it is preferable to provide the spiral flow generating part 55 in the heat source fluid flow path 672 to improve heat transfer performance.

[0053] Next, the heat source fluid introduction chamber 80 will be described with reference to Fig. 7(a) and (b). The heat source fluid introduction chamber 80 is provided outside the expansion chamber 21 (on the upper side in this embodiment), and the heat source fluid introduction chamber 80 and the expansion chamber 21 are partitioned by the ceiling wall 27 of the cylinder 2.

[0054] The heat source fluid introduction chamber 80 has an inlet 81 through which the heat source fluid is introduced into the heat source fluid introduction chamber 80 from the outside, and a guide port 82 which serves as an inlet for the heat source fluid from the heat source fluid introduction chamber 80 to the heat source fluid flow path 672. The inlet 81 is provided at the upper end of the heat source fluid introduction chamber 80, and the guide port 82 is provided in communication with the upper end of the heat source fluid flow path 672.

[0055] Since the heat source fluid introduction chamber 80 and the expansion chamber 21 are partitioned by the ceiling wall 27, the heat source fluid flowing through the heat source fluid introduction chamber 80 and the working gas flowing through the expansion chamber 21 exchange heat through the ceiling wall 27. As a result, the working gas on the expansion chamber 21 exchanges heat with the heat source fluid not only when it flows through the working gas flow passage 671 but also when it is present in the expansion chamber 21, so that it is possible to take in a lot of thermal energy from the heat source fluid.

[0056] A plurality of grooves 29 are provided on the ceiling wall 27 on the expansion chamber 21 side. The plurality of grooves 29 are not surface roughness formed during manufacturing, but are formed by design. Note that, although Fig. 7(b) shows an example in which the plurality of grooves 29 are provided on the expansion chamber 21 side, the plurality of grooves 29 may be provided on the outside of the expansion chamber 21, i.e., on the heat-source fluid introduction chamber 80 side, or may be provided on both the expansion chamber 21 side and the heat-source fluid introduction chamber 80 side.

[0057] The plurality of grooves 29 are provided over the entire area of ​​the ceiling wall 27, and extend from the center side of the ceiling wall 27 toward the outer periphery side (the heater 67 side).

[0058] Since the surface area of ​​the ceiling wall 27 is increased by forming the multiple grooves 29 in the ceiling wall 27, the working gas can take in more thermal energy from the heat source fluid, improving the efficiency of heat exchange between the working gas and the heat source fluid via the ceiling wall 27. As a result, it is possible to improve the thermal efficiency and output performance of the Stirling engine 1. Note that the multiple grooves 29 do not need to be provided over the entire area of ​​the ceiling wall 27, and may be provided partially.

[0059] In FIG. 7B, an example is shown in which the multiple grooves 29 extend linearly from the center side to the outer periphery side, but this is not limited thereto. The multiple grooves 29 may extend, for example, in a broken line shape (a shape in which the extension direction changes midway) from the center side to the outer periphery side, or may extend in a curved line shape from the center side to the outer periphery side. Furthermore, depending on the position of the ceiling wall 27, the multiple grooves 29 may be a combination of straight, broken, and curved grooves. In this way, by appropriately changing the shape of the multiple grooves 29, it is possible to take in more heat energy.

[0060] The ceiling wall 27 is provided with a protruding portion 28 having a substantially conical shape protruding toward the expansion chamber 21. The protruding portion 28 is formed by recessing a part of the ceiling wall 27 toward the expansion chamber 21, and is provided so that the central axis of the protruding portion 28 coincides with the central axis of the cylinder 2. Since the ceiling wall 27 is provided with the protruding portion 28, the surface area of ​​the ceiling wall 27 can be increased compared to the case where the ceiling wall 27 is formed in a flat plate shape. Therefore, the thermal energy taken in by the working gas can be further increased, and the efficiency of heat exchange between the working gas and the heat source fluid via the ceiling wall 27 is further improved. Furthermore, by providing the protruding portion 28, the pressure resistance of the ceiling wall 27 is also increased.

[0061] The heat source fluid introduction chamber 80 is provided with a guide portion 83 that guides the heat source fluid toward the top 28a of the protruding portion 28 of the ceiling wall 27. The guide portion 83 extends along the central axis of the protruding portion 28, and is extended to a position where it overlaps with the protruding portion 28 in the axial direction of the cylinder 2. As shown by the dashed line in (a) of FIG. 7, the guide portion 83 guides the heat source fluid that has flowed in from the introduction port 81 to the top 28a of the ceiling wall 27. The heat source fluid guided to the top 28a by the guide portion 83 flows radially outward along the protruding portion 28 that is substantially conical in shape, and is introduced into the heat source fluid flow path 672 from the guide port 82. This makes it easier for the heat source fluid to flow along the ceiling wall 27, and the heat exchange efficiency between the working gas and the heat source fluid via the ceiling wall 27 can be further improved.

[0062] Furthermore, since the multiple grooves 29 extend from the top 28a of the protruding portion 28 to the heater 67 side, the heat source fluid can flow smoothly from the top 28a to the heater 67 side.

[0063] (cooler) As shown in FIG. 8, the cooler 68, like the heater 67, has a plurality of first partition walls 60a extending in the radial direction and provided at predetermined intervals in the circumferential direction.

[0064] 2 and 8, in the cooler 68, working gas circulation layers 65 through which the working gas flows and cooling fluid circulation layers 66 through which the cooling fluid flows are alternately formed in the circumferential direction, with the first partition wall 60a between them. The cooler 68 is a plate-type heat exchanger in which the working gas and the cooling fluid exchange heat with each other via the first partition wall 60a. In this embodiment, since the cooling fluid has a lower temperature than the working gas, the cooler 68 cools the working gas that flows in and out of the compression chamber 22 via the second communication portion 23b of the first cylinder 23.

[0065] The second inlet / outlet portion 61b described above is provided at the lower end of the inner circumferential wall 61 where the working gas flow layer 65 is located. The second inlet / outlet portion 61b is formed in a slit shape having substantially the same shape as the corresponding second communication portion 23b, and is disposed opposite the corresponding second communication portion 23b of the first cylinder 23. In the heat exchanger 6, the second inlet / outlet portion 61b serves as an inlet / outlet to the compression chamber 22 of the cylinder 2.

[0066] The working gas flow layer 65 has a closed lower end 651 and an open upper end that communicates with a regenerator 69. The working gas flowing through the working gas flow layer 65 reverses its flow direction once per rotation of the crankshaft 10 due to the movement of the displacer piston 3.

[0067] The inner structures of the working gas flow layer 65 and the cooling fluid flow layer 66 will be described in more detail. The cooler 68 has a plurality of working gas flow paths 681 provided in the working gas flow layer 65 through which the working gas flows, and a plurality of cooling fluid flow paths 682 provided in the cooling fluid flow layer 66 through which the cooling fluid flows. In this embodiment, two cooling fluid flow paths 682 are provided in each cooling fluid flow layer 66 side by side in the circumferential direction, and each cooling fluid flow path 682 is partitioned by a third partition wall 60c extending in the radial direction. Each working gas flow path 681 is also partitioned by a first partition wall 60a and a second partition wall 60b, similar to each working gas flow path 671 and each heat source fluid flow path 672. The configuration of the working gas flow path 681 is the same as the configuration of the working gas flow path 671 provided in the heater 67, so a detailed description thereof will be omitted.

[0068] Fig. 9 is a diagram illustrating a working gas passage 681 and a cooling fluid passage 682 provided in the cooler 68. Note that in Fig. 9, the partition wall 60 is omitted from illustration.

[0069] The working gas flow passage 681 extends in the vertical direction, with its lower end communicating with the compression chamber 22 via a space 650 and a second inlet / outlet portion 61b (described later), and its upper end communicating with the regenerator 69. In each working gas flow layer 63, a plurality of working gas flow passages 681 are provided in parallel along the radial direction.

[0070] The lower end of the working gas flow passage 681 is located at a position farther from the closed lower end 651 of the working gas flow layer 65, as the working gas flow passage 681 is located closer to the second inlet / outlet portion 61b (i.e., closer to the inner periphery). That is, the working gas discharged from the working gas flow passage 681 located closer to the second inlet / outlet portion 61b is discharged at a position farther from the lower end 651 of the working gas flow layer 65.

[0071] In the working gas flow layer 63 of the cooler 68, a space 650 formed by the lower end 651 and lower ends of the multiple working gas flow paths 681 has a substantially triangular shape in side view. Similarly to the multiple working gas flow paths 671, the multiple working gas flow paths 681 are formed by separating a pair of first partition walls 60a with a second partition wall 60b. Therefore, the description of the working gas flow path 671 will be used and will not be repeated here.

[0072] Each cooling fluid flow path 682 is formed by folding back a radially extending tubular member at one radial end (e.g., outer circumferential end) and then folding back at the other radial end (e.g., inner circumferential end), and repeating this process. Each cooling fluid flow path 682 is formed in a so-called zigzag shape. By forming each cooling fluid flow path 682 not from a plurality of linear flow paths but from a single flow path in a folded state, the contact surface of the cooling fluid with the cooling fluid flow path 682 can be increased.

[0073] As shown in FIG. 1, the cooling fluid flow path 682 has an inlet 683 provided at the lower end side in the vertical direction and an outlet 684 provided at the upper end side, and is configured so that the cooling fluid flows upward overall.

[0074] When the working gas heated by the heater 67 flows from the upper end side to the lower end side, i.e., into the cooler 68, the working gas flowing through the working gas passage 681 has a temperature distribution in which the temperature decreases from the upper end side to the lower end side, i.e., from the expansion chamber 21 side to the compression chamber 22 side, and the cooling fluid flowing through the cooling fluid passage 682 has a temperature distribution in which the temperature increases from the lower end side to the upper end side. In other words, when the working gas flows from the upper end side to the lower end side, the working gas and the cooling fluid flow in the working gas passage 681 and the cooling fluid passage 682 have a counterflow temperature distribution as a whole, so that high heat exchange efficiency can be achieved in the cooler 68. Furthermore, the contact area between the working gas and the cooling fluid is increased by the cooling fluid passage 682 formed in a zigzag shape, so that the heat exchange efficiency in the cooler 68 is higher. When the working gas flows from the lower end side to the upper end side, the working gas and the cooling fluid flow through the working gas passage 681 and the cooling fluid passage 682 so as to achieve a parallel flow temperature distribution overall.

[0075] (Regenerator) When the working gas moves from the high-temperature expansion chamber 21 to the low-temperature compression chamber 22, the regenerator 69 cools the working gas by absorbing (i.e., storing) thermal energy of the working gas, and conversely, when the working gas moves from the low-temperature compression chamber 22 to the high-temperature expansion chamber 21, the regenerator 69 heats the working gas by providing (i.e., dissipating) the stored thermal energy to the working gas.

[0076] As shown in FIG. 2, the regenerator 69 has a heat storage body 71 capable of storing heat of the working gas, and a housing 70 surrounding the heat storage body 71.

[0077] The housing 70 is provided in a double cylindrical shape, and includes the above-mentioned inner peripheral wall 61 and outer peripheral wall 62. A heat storage body 71 is housed in the internal space of the housing 70.

[0078] In this embodiment, the heat storage body 71 and the housing 70 are continuously connected to each other and provided as an integral unit. To be more specific, the regenerator 69 is an additive manufacturing body in which metal powder is laminated, and the heat storage body 71 and the housing 70 are provided as an integral unit by metal additive manufacturing. With this configuration, it is possible to employ a complex structure having high heat exchange performance compared to conventional regenerators formed by incorporating a metal mesh, foam metal, or the like as a heat storage body in a housing. Furthermore, the number of assembly steps can be reduced.

[0079] The structure of the heat storage body 71 will be described below with reference to Figures 10 to 15. Note that the structure of the heat storage body 71 shown in Figures 10 to 15 is just an example, and the structure of the heat storage body 71 can take various shapes. In the following description, the vertical direction in the figures, i.e., the flow direction of the working gas, will also be referred to as a first direction, and the horizontal direction in the figures, i.e., the direction intersecting with the first direction, will also be referred to as a second direction.

[0080] The heat storage body 71 includes a plurality of side elements 73, which are three-dimensionally connected in series and integrally provided.

[0081] More specifically, the heat storage body 71 includes a unit structure 72 formed by connecting a plurality of side elements 73 to each other as shown in Fig. 10 and Fig. 11, and is configured by continuously arranging a plurality of unit structures 72 in the flow direction of the working gas and in the direction intersecting therewith. In the example shown in Fig. 10 and Fig. 11, the unit structure 72 has a three-dimensional shape formed by connecting atoms arranged at positions other than the vertices in a unit lattice of a diamond structure with the side elements 73. The unit structure 72 can have various structures, and may have a structure in which the vertices of a polyhedron such as a regular dodecahedron or a regular icosahedron are connected with the side elements 73.

[0082] The heat storage body 71 is constructed by a plurality of edge elements 73 which are continuously connected in a three-dimensional shape and integrally arranged, so that the dead volume, which is the volume within the housing 70 that is not involved in heat exchange, can be reduced, and the heat storage performance of the regenerator 69 can be improved.

[0083] Each side element 73 has a plate shape. The thickness of each side element 73 is, for example, 0.1 mm or less, and is configured finely. Each side element 73 needs to repeatedly store and release heat in a short period of time when transferring thermal energy to and from the working gas, so it is formed finely in this way to reduce its thermal capacity.

[0084] 12 and 13, each side element 73 has a face 731 with a maximum surface area that is provided along the first direction. That is, each side element 73 is provided so that a projected area S2 when viewed from the second direction is larger than a projected area S1 when viewed from the first direction.

[0085] Since the projected area S1 in the first direction is small, the side elements 73 are prevented from interfering with the flow of the working gas, and the pressure loss when the working gas flows in the first direction can be reduced. Furthermore, since the projected area S2 in the second direction is large, the contact surface along the flow of the working gas is increased, and the amount of heat stored in the heat storage body 71 can be increased. Therefore, each side element 73 can achieve both reduced pressure loss and improved heat exchange efficiency.

[0086] In each side element 73, an end 732 on the heater 67 side and an end 733 on the cooler 68 side are provided in a curved shape in a cross section cut along the first direction. Specifically, as shown in FIG. 12, a cross section 73s of each side element 73 cut along the first direction has an elliptical shape, and both ends of the major axis of the ellipse correspond to the ends 732, 733. This can reduce pressure loss when the working gas collides with the ends 732, 733 of each side element 73. Note that the cross-sectional shape of each side element 73 cut along the first direction is arbitrary and is not limited to an elliptical shape, and may be, for example, a rectangular shape, but it is preferable that the ends 732, 733 are provided in a curved shape or inclined shape.

[0087] 14 and 15 show a top view and a side view of the regenerator 69 in a state in which the heat storage body 71 is housed in the housing 70. Note that only a portion in the first direction is shown in Fig. 15. As shown in Fig. 14 and 15, the heat storage body 71 is uniformly arranged in the circumferential direction and the axial direction (first direction) within the housing 70, and as described above, the housing 70 and the heat storage body 71 are continuously connected to each other and provided integrally, so that the strength of the regenerator 69 is high.

[0088] 14, when the heat storage body 71 is viewed from the first direction, the heat storage body 71 has through-holes 74 that are regularly arranged and penetrate from the end on the heater 67 side to the end on the cooler 68 side. Specifically, each unit structure 72 has four through-holes that are partitioned into a lattice shape by a plurality of side elements 73 when viewed from the first direction, and by providing a plurality of unit structures 72 in succession in the first direction, the heat storage body 71 having through-holes 74 arranged in a lattice shape between the inner circumferential wall 61 and the outer circumferential wall 62 is formed.

[0089] In this way, since the heat storage body 71 has the through-holes 74 penetrating in the first direction, the working gas can smoothly pass through the internal space of the heat storage body 71. For example, when the heat storage body is configured by stacking a plurality of metal meshes or the like as in the conventional heat storage body, if the positions of the metal meshes are misaligned, a through-hole is not formed and clogging may occur inside the heat storage body, whereas in the heat storage body 71 of this embodiment, the through-holes 74 can be reliably provided.

[0090] In the first direction, the heat storage body 71 has a greater amount of heat exchange with the working gas at the position closer to the heater 67 where the working gas is at a higher temperature and at the position closer to the cooler 68 where the working gas is at a lower temperature, whereas the amount of heat exchange with the working gas is relatively small at the central position in the first direction.

[0091] Therefore, each side element 73 of the heat storage body 71 may be configured to have a different shape depending on the position in the first direction. For example, the side element 73 arranged in the center part in the first direction may have a smaller projected area S2 in the second direction than the side elements 73 arranged on both sides of the heat storage body 71 in the first direction.

[0092] In the heat exchanger 6 described above, the heater 67, the cooler 68, and the regenerator 69 are continuously connected to each other and provided as an integral unit. Specifically, the heater 67, the cooler 68, and the regenerator 69 are continuously connected to each other and provided as an integral unit by additive manufacturing of a metal powder material, which will be described later.

[0093] Since each vessel is provided integrally, there is no need to provide the heater, cooler, and regenerator separately and connect the vessels by brazing, welding, or the like, or to provide flanges on each vessel and connect them by bolting at the flanges. This makes it possible to shorten the manufacturing time and reduce the manufacturing costs of the heat exchanger 6. In addition, since no members are required for connection, the heat exchanger 6 can be made smaller and lighter.

[0094] Furthermore, in a heat exchanger constructed by combining a heater, regenerator, and cooler that are provided separately, leakage of working gas may occur at the connection points. However, in this embodiment, each device is provided integrally, so that leakage of working gas can be avoided.

[0095] [Heat exchanger manufacturing method] The heat exchanger 6 of this embodiment is formed by additive manufacturing technology (hereinafter also referred to as AM technology), which can manufacture parts with complex three-dimensional shapes by stacking and solidifying metal powder material one layer at a time. AM technology makes it possible to manufacture parts with fine and complex three-dimensional shapes that were difficult to manufacture using conventional manufacturing methods such as machining and casting.

[0096] Although the heater 67 and the cooler 68 each have flow paths with a fine and complicated three-dimensional shape (i.e., the working gas flow paths 671, 681, the heat source fluid flow path 672, and the cooling fluid flow path 682), they can be manufactured by the AM technology. In particular, the structure in which the spiral flow generating part 55 is provided in the fine heat source fluid flow path 672 is difficult to manufacture by the conventional manufacturing method that does not use the AM technology.

[0097] Conventional regenerators are not manufactured by AM technology, but are constructed by stacking metal meshes or the like inside a housing, but the regenerator 69 of this embodiment can be manufactured by AM technology by integrally forming the housing 70 and the heat storage body 71. In particular, the heat storage body 71 has a fine and complex three-dimensional shape realized by AM technology, and is difficult to manufacture by conventional manufacturing methods that do not use AM technology.

[0098] In this way, the heater 67, the cooler 68, and the regenerator 69 can each be manufactured by AM technology, and in this embodiment, they are integrally formed by AM technology. As a result, as described above, the process for joining the respective devices (such as brazing) is not required, and the manufacturing time and manufacturing costs of the heat exchanger 6 can be shortened.

[0099] In addition, the first cylinder 23 and its ceiling wall 27 provided on the inner periphery of the heat exchanger 6, the heater 67 and the heat source fluid introduction chamber 80 provided above the first cylinder 23, and the heat source fluid discharge passage 51 provided on the outer periphery of the heat exchanger 6 are integrally formed with the heat exchanger 6 by AM technology. Specifically, as shown in Fig. 16, for example, the metal powder material is layer-by-layer solidified upward from the flange portion 25 of the first cylinder 23 as the bottom surface to perform additive manufacturing. In particular, the multiple grooves 29 provided in the ceiling wall 27 of the first cylinder 23 have a fine shape, and are difficult to form by a conventional manufacturing method that does not use AM technology.

[0100] This eliminates the need to assemble the heat exchanger 6, the first cylinder 23, the heat source fluid inlet chamber 80, and the heat source fluid outlet passage 51, thereby shortening the manufacturing time and reducing the manufacturing costs of the Stirling engine 1. Note that the first cylinder 23, the heat source fluid inlet chamber 80, and the heat source fluid outlet passage 51 do not necessarily have to be formed integrally with the heat exchanger 6, and one or two of them may be formed integrally with the heat exchanger 6.

[0101] Furthermore, because AM technology makes it possible to manufacture fine flow paths and heat storage bodies 71, it is possible to miniaturize the heat exchanger 6. In a Stirling engine, if the heat exchanger is large, the dead volume of the space through which the working gas flows increases, and the compressibility of the working gas decreases, resulting in reduced thermal efficiency and output. In this embodiment, by miniaturizing the heat exchanger 6, the proportion of the dead volume in the volume of the heat exchanger 6 can be reduced, and the thermal efficiency and output of the Stirling engine 1 can be improved.

[0102] Incidentally, when additively manufacturing a part having a predetermined size, in order to laminate the metal powder material at an inclination angle less than a predetermined angle (e.g., less than 45 degrees) with respect to the plane intersecting with the lamination direction, it is necessary to simultaneously form a support material that supports the inclined portion from below by additive manufacturing. If a support material is formed, it is necessary to remove the support material, for example by manual labor, after manufacturing the part.

[0103] In this embodiment, the inclination angle of the heat exchanger 6, the first cylinder 23, the heat source fluid introduction chamber 80, and the heat source fluid discharge path 51, which are stacked at an angle upward, is appropriately set to the above-mentioned predetermined angle or more (for example, 45 degrees), making it unnecessary to form a support material during additive manufacturing. As shown in Fig. 16, for example, the inclination angle of the wall surface of the heat source fluid discharge path 51 and the discharge part 52 of the heat source fluid discharge path 51, which are stacked at an angle upward, is set to 45 degrees. This makes it possible to avoid the formation of a support material.

[0104] (Modification) In the above embodiment, the Stirling engine 1 has been described as an example of the Stirling engine of the present invention, but the present invention is not limited to this. For example, the Stirling engine of the present invention may be a heat pump that uses a reverse Stirling cycle. Specifically, the heat pump as the Stirling engine may be configured such that the generator 11 of the Stirling engine 1 described above functions as a motor that inputs power to the piston crank mechanism 5, and causes the displacer piston 3 and the power piston 4 to reciprocate.

[0105] When the heat exchanger 6 is applied to a heat pump as a Stirling engine, the generator 11 is made to function as a motor, so that the fluid flowing through the heater 67 receives heat from the working gas and becomes a high-temperature fluid, and the fluid flowing through the cooler 68 has heat absorbed by the working gas and becomes a low-temperature fluid. In this embodiment, the heat exchanger 6 has a high heat exchange performance with reduced dead volume due to its fine internal structure, so that the fluid can be heated to an ultra-high temperature or cooled to an extremely low temperature.

[0106] Although one embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. In addition, the components in the above embodiment may be arbitrarily combined within the scope of the invention.

[0107] For example, in the above embodiment, the β-type Stirling engine 1 has been described as an example of a Stirling engine to which the heat exchanger 6 is applied, but the present invention is not limited to this. The heat exchanger 6 may be applied to other types of Stirling engines, specifically, an α-type Stirling engine, a γ-type Stirling engine, or the like.

[0108] In the above embodiment, the regenerator 69 is applied to the Stirling engine 1, which is an example of a Stirling engine, but the regenerator 69 is not limited to this and can be applied to various heat engines.

[0109] In the above embodiment, the side elements 73 constituting the heat storage body 71 have a plate shape, but this is not limited thereto, and they may be linear bodies.

[0110] This specification describes at least the following items. In parentheses, components corresponding to the above-described embodiment are shown as examples, but the present invention is not limited to these.

[0111] (1) A heat exchanger (heat exchanger 6) for a Stirling engine (Stirling engine 1) including a heater (heater 67), a regenerator (regenerator 69), and a cooler (cooler 68) connected in series in the flow direction of a working fluid (working gas), and in which an expansion chamber (expansion chamber 21) and a compression chamber (compression chamber 22) are communicated with each other via the heater, the regenerator, and the cooler, The regenerator comprises: A heat storage body (heat storage body 71) capable of storing heat of the working fluid; A housing (housing 70) that surrounds the heat storage body, The heat storage body and the housing are continuously connected to each other and integrally provided. Stirling engine heat exchanger.

[0112] According to (1), the regenerator has a structure in which the heat storage body and the housing are continuously connected to each other and are integrally provided, so that a complex structure having high heat exchange performance can be adopted compared to a regenerator in which multiple metal meshes are incorporated into a housing as a heat storage body. Furthermore, the assembly man-hours for the regenerator can be reduced.

[0113] (2) A heat exchanger for a Stirling engine according to (1), The heat storage body is configured by a plurality of side elements that are continuously connected in a three-dimensional shape and integrally provided, Each side element has a plate shape in which a projected area (projected area S2) as viewed from a second direction intersecting with a first direction which is a flow direction of the working fluid is larger than a projected area (projected area S1) as viewed from the first direction. Stirling engine heat exchanger.

[0114] According to (2), each side element that constitutes the heat storage body is connected continuously in a three-dimensional manner and has a plate shape whose projected area as viewed from a second direction intersecting the first direction is larger than the projected area as viewed from the first direction. This reduces the pressure loss when the working fluid flows through the regenerator and increases the heat storage capacity of the heat storage body.

[0115] (3) A heat exchanger for a Stirling engine according to (2), In each side element, in a cross section (cross section 73s) cut along the first direction, the end portion (end portion 732) on the heater side and the end portion (end portion 733) on the cooler side are curved or inclined. Stirling engine heat exchanger.

[0116] According to (3), the pressure loss caused by the working fluid colliding with each side element can be reduced.

[0117] (4) A heat exchanger for a Stirling engine according to (2) or (3), The projected area of ​​each side element of the heat storage body in the first direction is larger than that of the central portion of the heat storage body in the first direction. Stirling engine heat exchanger.

[0118] Since both side portions of the heat storage body in the first direction are close to the heater and the cooler, the amount of heat exchange between the working fluid and the heat storage body is large. According to (4), the projected area of ​​each side element in the both side portions of the heat storage body as viewed from the second direction is increased, thereby improving the heat exchange efficiency in the areas where the amount of heat exchange is large.

[0119] (5) A heat exchanger for a Stirling engine according to any one of (1) to (4), The heat storage body has a through-hole (through-hole 74) that penetrates from the end on the heater side to the end on the cooler side when viewed from the flow direction of the working fluid and is regularly arranged. Stirling engine heat exchanger.

[0120] According to (5), a heat storage body that is not clogged along the flow direction of the working fluid can be obtained.

[0121] (6) A heat exchanger for a Stirling engine according to any one of (1) to (5), The regenerator is a layered product in which metal powder is layered. Stirling engine heat exchanger.

[0122] According to (6), a regenerator having a housing and a heat storage body that are continuously connected to each other and provided as an integral unit can be formed by additive manufacturing.

[0123] (7) A method for manufacturing a heat exchanger for a Stirling engine according to any one of (1) to (5), comprising the steps of: The heat storage body and the housing of the regenerator are integrally formed by layer-by-layer manufacturing of metal powder; A method for manufacturing a heat exchanger.

[0124] According to (7), a regenerator having a housing and a heat storage body that are continuously connected to each other and provided as an integral unit can be formed by additive manufacturing.

[0125] (8) A regenerator (regenerator 69) in which a fluid (working gas) flows through an internal space, A heat storage body (heat storage body 71) capable of storing heat of the fluid; A housing (housing 70) that surrounds the heat storage body, The heat storage body and the housing are continuously connected to each other and integrally provided, The heat storage body is configured by a plurality of side elements (side elements 73) that are continuously connected in a three-dimensional shape and integrally provided, Each side element has a plate shape in which a projected area (projected area S2) as viewed from a second direction intersecting with a first direction which is a flow direction of the working fluid is larger than a projected area (projected area S1) as viewed from the first direction. Regenerator.

[0126] According to (8), since the heat storage body and the housing are continuously connected to each other and integrally provided, a complex structure having high heat exchange performance can be adopted as the heat storage body, compared to a regenerator in which multiple metal meshes are incorporated into the housing. Also, each side element that is continuously connected in a three-dimensional shape constituting the heat storage body has a plate shape whose projected area as viewed from a second direction intersecting with the first direction is larger than the projected area as viewed from the first direction, so that the pressure loss when the working fluid flows through the regenerator can be reduced and the heat storage amount of the heat storage body can be increased. Furthermore, the man-hours required for assembling the regenerator can be reduced. [Explanation of symbols]

[0127] 1. Stirling engine 6 Heat exchanger 21 Expansion chamber 22 Compression chamber 67 Heater 68 Cooler 69 Regenerator 70 Case 71 Heat storage body 73 Edge elements 73s cross section 74 Penetration 732 End 733 End S1 Projected area S2 projected area

Claims

1. A heat exchanger for a Stirling engine, comprising a heater, a regenerator, and a cooler connected in series in a flow direction of a working fluid, and an expansion chamber and a compression chamber communicated with each other via the heater, the regenerator, and the cooler, The regenerator comprises: A heat storage body capable of storing heat of the working fluid; A housing that surrounds the heat storage body, The heat storage body and the housing are continuously connected to each other and integrally provided. Stirling engine heat exchanger.

2. 2. A heat exchanger for a Stirling engine according to claim 1, The heat storage body is configured by a plurality of side elements that are continuously connected in a three-dimensional shape and integrally provided, Each side element has a plate shape in which a projected area as viewed from a second direction intersecting with a first direction which is a flow direction of the working fluid is larger than a projected area as viewed from the first direction. Stirling engine heat exchanger.

3. 3. A heat exchanger for a Stirling engine according to claim 2, In each side element, in a cross section cut along the first direction, the end portion on the heater side and the end portion on the cooler side are provided in a curved or inclined shape. Stirling engine heat exchanger.

4. 3. A heat exchanger for a Stirling engine according to claim 2, The projected area of ​​each side element in the second direction of the heat storage body is larger than that of a central portion of the heat storage body in the first direction. Stirling engine heat exchanger.

5. A heat exchanger for a Stirling engine according to any one of claims 1 to 4, The heat storage body has a through-hole that penetrates from the end on the heater side to the end on the cooler side when viewed from the flow direction of the working fluid and is regularly arranged. Stirling engine heat exchanger.

6. A heat exchanger for a Stirling engine according to any one of claims 1 to 4, The regenerator is a layered product in which metal powder is layered. Stirling engine heat exchanger.

7. A method for manufacturing a heat exchanger according to any one of claims 1 to 4, comprising the steps of: The heat storage body and the housing of the regenerator are integrally formed by layer-by-layer manufacturing of metal powder; A method for manufacturing a heat exchanger.

8. A regenerator in which a fluid flows through an internal space, A heat storage body capable of storing heat of the fluid; A housing that surrounds the heat storage body, The heat storage body and the housing are continuously connected to each other and integrally provided, The heat storage body is configured by a plurality of side elements that are continuously connected in a three-dimensional shape and integrally provided, Each side element has a plate shape in which a projected area viewed from a second direction intersecting with a first direction which is a flow direction of the fluid is larger than a projected area viewed from the first direction. Regenerator.

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