JP2022126185A - Heat exchanger - Google Patents

Abstract

To provide a heat exchanger which achieves improvement of heat transfer performance.SOLUTION: A heat exchanger 6 includes: multiple heat transfer plates 60 which are disposed in a stacking manner while forming a predetermined space therebetween and in which a working gas circulation layers 63 for circulating a working gas and heat source gas circulation layers 64 for circulating a heat source gas are alternately formed in a stacking direction; and a passage formation part which forms multiple working gas passage 671 and multiple heat source gas passages 672, in which the working gas or the heat source gas flows, along a flow direction of the working gas or the heat source gas in the working gas circulation layers 63 and the heat source gas circulation layers 64. The passage formation part is formed by multiple heat transfer fins which form borders between the multiple working gas passages 671 and the multiple heat source gas passages 672 and are formed by integral molding with the multiple heat transfer plates 60.SELECTED DRAWING: Figure 2

Description

The present invention relates to heat exchangers.

2. Description of the Related Art Conventionally, heat exchangers for heat exchange of fluids include tube heat exchangers and plate heat exchangers. A plate-type heat exchanger alternately flows a cooling medium and a heating medium through a plurality of fluid layers provided between a plurality of stacked heat transfer plates, and performs heat exchange between the fluids through the heat transfer plates (for example, See Patent Document 1).

Japanese Unexamined Patent Application Publication No. 2016-1083

By the way, in order to improve the heat transfer performance of a plate-type heat exchanger, the interval between the heat transfer plates is narrowed to increase the number of heat transfer plates, or the partition walls provided between the heat transfer plates are made thinner. , increasing the surface area of the flow path contacted by the fluid. However, there is a limit to doing this by press working.

One aspect of the present invention is a heat exchanger that exchanges heat between a first fluid and a second fluid. The heat exchanger is arranged in a stacked state with a predetermined interval, and has a plurality of heat transfer layers alternately configured in the stacking direction of a first circulation layer for circulating the first fluid and a second circulation layer for circulating the second fluid. a plate, a flow path forming portion that forms a plurality of flow paths through which the first fluid or the second fluid flows in the first flow layer and the second flow layer along the flow direction of the first fluid or the second fluid; Prepare. The flow path forming portion forms boundaries between the plurality of flow paths, and is configured by a plurality of heat transfer fins integrally formed with a plurality of heat transfer plates.

ADVANTAGE OF THE INVENTION According to this invention, the heat exchanger which improved the heat-transfer performance can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the principal part structure of the Stirling engine to which the heat exchanger which concerns on embodiment of this invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the principal part structure of the heat exchanger which concerns on embodiment of this invention. FIG. 3 is a cross-sectional view of main parts of the heat exchanger taken along line III-III in FIG. 2; FIG. 4 is a diagram schematically showing working gas flow paths and heat source gas flow paths provided in the heating portion of the heat exchanger according to the embodiment of the present invention; FIG. 4 is a diagram schematically showing working gas flow paths provided in the heating section and the cooling section of the heat exchanger according to the embodiment of the present invention; FIG. 4 is a diagram schematically showing working gas flow paths and cooling water flow paths provided in the cooling portion of the heat exchanger according to the embodiment of the present invention;

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. FIG. The heat exchanger according to the present embodiment is a plate-type heat exchanger that exchanges heat by alternately circulating a cooling medium and a heating medium between heat transfer plates, and can be applied to various shapes. . For example, a substantially rectangular parallelepiped heat exchanger in which rectangular heat transfer plates are stacked at predetermined intervals, or a substantially cylindrical heat exchanger in which heat transfer plates are stacked at predetermined intervals in the circumferential direction It can be applied to vessels and the like. An example of a substantially cylindrical heat exchanger applied to a β-type Stirling engine will be described below.

FIG. 1 is a cross-sectional view showing the main structure of a Stirling engine 1 to which a heat exchanger according to an embodiment of the invention is applied. In addition, in FIG. 1, in order to explain the main part configuration of the heat exchanger 6 in an easy-to-understand manner, a working gas circulation layer (first circulation layer) 63 through which the working gas (first fluid) flows, a heat source gas (second fluid) ) through which the heat source gas flow layer (second flow layer) 64 and the cooling water flow path 682 through which the cooling water flows are shown simultaneously in the heat exchanger 6 of FIG.

As shown in FIG. 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 which are installed in the cylinder 2, and a piston connected to the displacer piston 3 and the power piston 4. It is composed of a crank mechanism 5 and a heat exchanger 6 that raises and lowers the temperature of the working gas in the cylinder 2 .

The Stirling engine 1 is a so-called hermetic type engine, and a generator 11 that takes out the shaft rotation output of the piston crank mechanism 5 as electric power is arranged inside the crankcase. By making the Stirling engine 1 a hermetic type engine, a rotating shaft for extracting shaft rotation output to the outside is not required, and a sealing member for sealing the rotating shaft which causes leakage of working gas is not required.

The cylinder 2 has a substantially cylindrical shape with one end closed and the other end open. In the cylinder 2, a displacer piston 3 is arranged on the closed side in the axial direction, and a power piston 4 is arranged on the opening side. Between the displacer piston 3 and the closed portion of the cylinder 2 arranged in this way, an expansion chamber 21 is formed in which the working gas is at a high temperature. The compression chamber 22 is configured as follows. The expansion chamber 21 and the compression chamber 22 within the cylinder 2 are hereinafter referred to as working space 20 .

The cylinder 2 includes a first cylinder 23 located on the closed portion side in the axial direction, and a second cylinder 24 located on the opening side and having the same diameter as the first cylinder 23 . The cylinder 23 and the second cylinder 24 are coaxially connected by flange portions 25 and 26 that they have.

A plurality of first communication portions 23a are provided on the outer peripheral surface of the upper end portion (closed portion) of the first cylinder 23 and communicate with each of a plurality of first entrance portions (entrance portions) 61a of the heat exchanger 6, which will be described later. be done. The first communicating portions 23a are provided in the same number as the first inlet/outlet portions 61a. Each first communicating portion 23a is formed in a slit shape having substantially the same shape as the corresponding first inlet/outlet portion 61a, and is arranged to face the corresponding first inlet/outlet portion 61a. serves as an entrance to the expansion chamber 21 .

A plurality of second communication portions 23b are provided on the outer peripheral surface of the lower end portion (opening portion) of the first cylinder 23 and communicate with a plurality of second entrance portions (entrance portion) 61b of the heat exchanger 6, which will be described later. be done. The second communicating portions 23b are provided in the same number as the second inlet/outlet portions 61b. Each second communicating portion 23b is formed in a slit shape having substantially the same shape as the corresponding second inlet/outlet portion 61b, and is arranged to face the corresponding second inlet/outlet portion 61b, and the second communicating portion 23b is compressed. It becomes the doorway of the chamber 22 .

Displacer piston 3 and power piston 4 are coaxially arranged within cylinder 2 . The displacer piston 3 vertically divides the space formed by the cylinder 2 and the power piston 4 into two. In other words, the displacer piston 3 comprises 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 (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 communicating portions 23a and a plurality of second communicating portions 23b. The internal pressure of 6 is approximately the same.

The displacer piston 3 and the power piston 4 are connected to the crankshaft 10 via different connecting rods 30 and 40, respectively, so that the power piston 4 is in phase (90 degrees phase difference). , and the power piston 4 outputs rotational force to the piston crank mechanism 5 via the connecting rod 40 . Crankshaft 10 is connected to output shaft 16 of recoil starter 15 via coupling 14 .

The displacer piston 3 is used to move the working gas inside the cylinder 2 and moves the working gas inside the cylinder 2 to change the volume ratio of the expansion chamber 21 and the compression chamber 22 . For example, when a large amount of hot gas exists in the expansion chamber 21, the internal pressure of the cylinder 2 increases, and when a large amount of low temperature gas exists in the compression chamber 22, the internal pressure of the cylinder 2 decreases. In accordance with the timing of this pressure fluctuation, the power piston 4 is pushed down from near the top dead center when the pressure is high to obtain shaft rotation force output to the piston crank mechanism 5, and when the pressure is low, the power piston 4 is pushed by the piston crank mechanism 5. It is pushed up, and by repeating this, it is possible to obtain continuous rotational force.

FIG. 2 is a cross-sectional view showing the essential configuration of the heat exchanger 6 according to the embodiment of the present invention, and FIG. 3 is a cross-sectional view of the essential parts of the heat exchanger 6 taken along line III-III in FIG. be. As in FIG. 1, FIG. 2 shows a working gas circulation layer 63 through which the working gas flows, a heat source gas circulation layer 64 through which the heat source gas flows, and cooling water, in order to explain the main configuration of the heat exchanger 6 in an easy-to-understand manner. are simultaneously shown in the heat exchanger 6 of FIG.

As shown in FIGS. 2 and 3, the heat exchanger 6 is a generally cylindrical plate-type heat exchanger in which a plurality of radially extending heat transfer plates 60 are laminated in the circumferential direction. is. Specifically, the heat exchangers 6 are arranged in a state of being laminated in the circumferential direction at predetermined intervals, and a working gas circulation layer 63 for circulating the working gas and a heat source gas circulation layer 64 for circulating the heat source gas are arranged in the stacking direction. A plurality of heat transfer plates 60 alternately configured, a working gas flow layer 63 and a heat source gas flow layer 64 are provided with a working gas flow path through which the working gas flows and a heat source gas flow path through which the heat source gas flows. , an inner peripheral wall 61 arranged on the inner peripheral side, and an outer peripheral wall 62 arranged on the outer peripheral side.

In the heat exchanger 6, a plurality of heat transfer plates 60 constitute a partition wall that partitions into a working gas circulation layer 63 and a heat source gas circulation layer 64, and each of the plurality of heat transfer fins 60a is a laminated heat transfer plate. It connects the opposing surfaces of 60 and extends in the flow direction of the working gas and the heat source gas. In the heat exchanger 6, the plurality of heat transfer fins 60a and the plurality of heat transfer plates 60 are formed by integral molding using metal additive manufacturing. By integrally molding the plurality of heat transfer fins 60a and the plurality of heat transfer plates 60 by metal additive manufacturing, it is possible to form the working gas flow path 671 and the heat source gas flow path 672 into fine capillaries. For this reason, a high pressure difference can be achieved with a small wall thickness due to the capillary effect, and weight reduction is possible while ensuring pressure resistance.

A first inlet/outlet portion 61 a is provided at a position corresponding to the first communication portion 23 a of the first cylinder 23 at the upper end portion of the inner peripheral wall 61 where the working gas circulation 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 communicating portion 23a, and is arranged to face the corresponding first communicating portion 23a. The entrance/exit portion 61 a serves as an entrance/exit to the expansion chamber 21 of the cylinder 2 .

A second inlet/outlet portion 61b is provided at a position corresponding to the second communication portion 23b of the first cylinder 23 at the lower end portion of the inner peripheral wall 61 where the working gas circulation layer 63 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 arranged to face the corresponding second communication portion 23b. The entrance/exit portion 61 b serves as an entrance/exit to the compression chamber 22 .

The outer peripheral wall 62 where the heat source gas circulation layer 64 is located is provided with an outlet portion 62a at the lower end portion where the later-described heat source gas flow path 672 is located. The outlet part 62a is formed in a slit shape and arranged to face the corresponding heat source gas circulation layer 64, so that the heat source gas flowing out from the heat source gas circulation layer 64 can be discharged to the outside of the heat source gas circulation layer 64. be.

The heat exchanger 6 has a structure in which both ends in the axial direction (both ends in the direction in which the working gas flows) where the working gas flow layers 63 are located are closed. On the other hand, the upper end in the axial direction where the heat source gas circulation layer 64 is located is open so that, for example, the heat source gas can flow in from above. The heat exchanger is provided with an abutment portion 66 at a position where the heat source gas circulation layer 64 is located and which corresponds to an end portion of a heating portion 67 which will be described later. The abutting portion 66 is provided along the lower end of the outlet portion 62a provided in the outer peripheral wall 62, and is configured to discharge the heat source gas to the outside of the heat source gas circulation layer 64 through the outlet portion 62a. The heat source gas circulation layer 64 is divided into a heating section 67 and a regeneration section 69 by an abutting section 66 .

As shown in FIG. 2, the heat exchanger 6 includes a heating section 67 that heats the working gas, a cooling section 68 that cools the working gas, and a regeneration section 69 that stores the heat of the working gas. be.

The heating portion 67 is positioned on the upper end portion (closed portion) side of the first cylinder 23 and heats the working gas entering and exiting the expansion chamber 21 via the first communication portion 23 a of the first cylinder 23 . Specifically, the heating unit 67 is provided in the working gas circulation layer 63, and is provided in a plurality of working gas flow paths (first flow paths) 671 through which the working gas flows, and in the heat source gas flow layer 64. and a plurality of heat source gas flow paths (second flow paths) 672 for circulating a heat source gas for heating. The working gas flowing through the working gas flow path 671 reverses its flow direction once per rotation due to the movement of the displacer piston 3 . Working gases include high-pressure air, helium, and hydrogen.

FIG. 4 is a diagram schematically showing a working gas channel 671 and a heat source gas channel 672 provided in the heating section 67 of the heat exchanger 6 according to this embodiment. Note that FIG. 4 omits specific descriptions of the heat transfer plate 60, the heat transfer fins 60a, the first inlet/outlet portion 61a, and the like, which constitute the working gas circulation layer 63 and the heat source gas circulation layer 64. As shown in FIG.

As shown in FIGS. 2 and 4, the working gas flow passages 671 are formed to extend in the axial direction of the heat exchanger 6, and the plurality of working gas flow passages 671 are formed so that the working gas flows parallel to the axial direction. The paths 671 are arranged in parallel along the heat transfer plate 60 toward the first inlet/outlet portion 61a. In the plurality of working gas flow paths 671, the closer the working gas flow path 671 is to the first inlet/outlet portion 61a, the farther the axial end position is from the axial end portion 65 of the heat exchanger 6. configured to be located. That is, the working gas discharged from the working gas flow path 671 positioned closer to the first inlet/outlet portion 61 a is discharged at a position farther from the axial end portion 65 of the heat exchanger 6 .

As shown in FIGS. 2 and 4, in the working gas flow layer 63 of the heating unit 67, the axial end 65 of the heat exchanger 6 and the axial ends of the plurality of working gas flow paths 671 form The space has a substantially triangular shape when viewed from the side. In this space, the acute-angled portion is located on the opposite side (outer peripheral side) of the first entrance/exit portion 61a, and the portion that becomes the base opposite to the acute angle is located on the first entrance/exit portion 61a side (inner peripheral side). In this space, the flow of the working gas flowing out of the working gas flow path 671 bends toward the first inlet/outlet portion 61a. Since the cross section of the flow channel is shaped to expand, the flow velocity at each position becomes equal, and the 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 plurality of working gas flow paths 671, the pressure loss of the heat exchanger 6 including the first inlet/outlet portion 61a can be minimized. can be

FIG. 5 is a diagram schematically showing a working gas flow path 671 (working gas flow path 681) provided in the heating section 67 (cooling section 68). As shown in FIG. 5, the plurality of working gas flow paths 671 (working gas flow paths 681) are formed by partitioning the pair of heat transfer plates 60, 60 with the heat transfer fins 60a. The heat transfer fins 60a are formed by integrally molding and connecting the opposing surfaces of the pair of heat transfer plates 60, 60 to each other. At this time, the working gas circulation layer 63 is partitioned by the heat transfer fins 60a so that the plurality of working gas flow paths 671 (working gas flow paths 681) formed by the heat transfer fins 60a have the same equivalent diameter. By making the equivalent diameters of the working gas flow paths 671 (working gas flow paths 681) equal, the pressure loss coefficient and heat transfer coefficient become equal, and the drift of the working gas flowing through each working gas flow path 671 (working gas flow path 681) is prevented. disappears. Since the working gas flowing through the working gas flow path 671 (working gas flow path 681) does not drift, the pressure loss as a whole is reduced and the heat transfer performance is improved.

A protrusion 60b is provided on the inner wall that forms the working gas flow path 671 (the working gas flow path 681). By providing the protrusion 60b on the inner wall, the flow of the working gas flowing in the working gas flow path 671 (working gas flow path 681) is agitated by the vertical vortex flow, and the heat transfer coefficient can be improved.

As shown in FIGS. 2 and 4, the heat source gas channel 672 in the heating unit 67 is formed to extend in the axial direction of the heat exchanger 6, and the plurality of heat source gas channels 672 are arranged parallel to the axial direction. The heat source gas flow paths 672 are arranged in parallel along the heat transfer plate 60 toward the outlet portion 62a. The plurality of heat source gas flow paths 672 are configured such that the end positions in the axial direction of the heat source gas flow paths 672 located closer to the outlet portion 62 a are positioned farther from the abutment portion 66 . That is, the heat source gas discharged from the heat source gas flow path 672 positioned closer to the outlet portion 62 a is discharged at a position farther from the abutting portion 66 .

As shown in FIG. 2, in the heat source gas circulation layer 64 of the heating unit 67, the space formed by the abutment portion 66 of the heat exchanger 6 and the axial ends of the plurality of heat source gas flow paths 672 is and becomes a substantially triangular shape. In this space, the acute-angled portion is located on the opposite side (inner peripheral side) of the outlet portion 62a, and the portion that becomes the base opposite to the acute-angled portion is located on the outlet portion 62a side (outer peripheral side). In this space, the flow of the heat source gas flowing out of the heat source gas channel 672 bends toward the outlet 62a. The expanding shape equalizes the flow velocity at each position, minimizing pressure loss. Also, by setting the maximum area of the outlet portion 62a to be equal to the sum of the cross-sectional areas of the plurality of heat source gas flow paths 672, the pressure loss of the heat exchanger 6 including the outlet portion 62a can be minimized. can.

A plurality of heat source gas flow paths 672 are formed by partitioning the pair of heat transfer plates 60, 60 located in the heating section 67 with the heat transfer fins 60a. The heat transfer fins 60a are formed by integrally molding and connecting the opposing surfaces of the pair of heat transfer plates 60, 60 to each other. At this time, the heat source gas circulation layer 64 located in the heating portion 67 is partitioned by the heat transfer fins 60a so that the equivalent diameters of the heat source gas flow paths 672 formed by the heat transfer fins 60a are equal. By equalizing the equivalent diameter of the heat source gas flow paths 672, the pressure loss coefficient and the heat transfer coefficient become equal, and the heat source gas flowing through each heat source gas flow path 672 is prevented from drifting. Since the heat source gas flowing through the heat source gas flow path 672 does not drift, the pressure loss as a whole is reduced and the heat transfer performance is improved.

The cooling section 68 is located on the lower end (opening) side of the first cylinder 23 and cools the working gas entering and exiting the compression chamber 22 via the second communication section 23 b of the first cylinder 23 . Specifically, the cooling part 68 is provided in the working gas circulation layer 63 and is provided corresponding to a plurality of working gas flow paths 681 through which the working gas flows and the heat source gas circulation layer 64 to cool the working gas. and a cooling water flow path 682 for circulating cooling water. The working gas flowing through the working gas flow path 681 reverses its flow direction once per rotation due to the movement of the displacer piston 3 .

FIG. 6 is a diagram schematically showing a working gas channel 681 and a cooling water channel 682 provided in the cooling section 68 of the heat exchanger 6 according to this embodiment. Note that FIG. 6 omits specific description of the heat transfer plate 60, the heat transfer fins 60a, the second inlet/outlet portion 61b, and the like, which constitute the working gas circulation layer 63. As shown in FIG.

As shown in FIGS. 2 and 6, the working gas passages 681 in the cooling portion 68 are formed to extend in the axial direction of the heat exchanger 6, and the plurality of working gas passages 681 are arranged parallel to the axial direction. working gas flow paths 681 are arranged in parallel along the heat transfer plate 60 toward the first inlet/outlet portion 61a. In the plurality of working gas flow paths 681, the closer the working gas flow path 681 is to the second inlet/outlet portion 61b, the farther the axial end position is from the axial end portion 65 of the heat exchanger 6. configured to be located. That is, the working gas discharged from the working gas flow path 681 positioned closer to the second inlet/outlet portion 61 b is discharged at a position farther from the axial end portion 65 of the heat exchanger 6 .

Also in the working gas circulation layer 63 of the cooling part 68, the space formed by the axial end 65 of the heat exchanger 6 and the axial ends of the plurality of working gas flow paths 681 is substantially triangular in side view. shape. Therefore, the description of the heating unit 67 is used, and the description thereof is omitted here. Similarly, the plurality of working gas flow paths 681 are formed by partitioning the pair of heat transfer plates 60, 60 with the heat transfer fins 60a, similar to the plurality of working gas flow paths 671. As shown in FIG. Therefore, the description of the working gas flow path 671 is used, and the description thereof is omitted here.

As shown in FIGS. 2 and 6, the cooling water flow path 682 is formed by extending a radially extending tubular member of the heat exchanger 6 at one end (for example, After folding at the outer end), the other end (for example, the inner end) is folded back, and this is repeated to form a shape. The cooling water flow path 682 is formed in a so-called serpentine shape. By forming the cooling water channel 682 not from a plurality of linear channels but by bending one channel, for example, the liquid can flow at a position corresponding to the heat source gas circulation layer 64 in the cooling section 68. Also when flowing, it is possible to suppress the flow velocity of the liquid from decreasing. In the present embodiment, the temperature of the working gas flowing through the working gas channel 681 becomes lower as it is positioned further downstream. , the heat exchange efficiency is improved.

The regeneration unit 69 is located between the heating unit 67 and the cooling unit 68 and stores the heat of the working gas moving from the heating unit 67 to the cooling unit 68 or the working gas moving from the cooling unit 68 to the heating unit 67 . Specifically, when the working gas moves from the high-temperature expansion chamber 21 to the low-temperature compression chamber 22, the regeneration unit 69 accumulates heat to cool the high-temperature working gas. Conversely, when the working gas moves from the low-temperature compression chamber 22 to the high-temperature expansion chamber 21 , the heat energy stored in the working gas is applied to the working gas, thereby performing the same function as the heating section 67 . As a result, the fuel efficiency of the Stirling engine 1 can be greatly improved. The regeneration part 69 is made of, for example, a matrix material such as metal fiber.

In the Stirling engine 1 configured as described above, the displacer piston 3 is reciprocated by the rotational power of the crankshaft 10 via the piston crank mechanism 5, and the working gas moves back and forth between the expansion chamber 21 and the compression chamber 22. At this time, the working gas entering the expansion chamber 21 is heated by the heat exchanger 6 and the working gas entering the compression chamber 22 is cooled by the heat exchanger 6 . As the working gas moves back and forth between the expansion chamber 21 and the compression chamber 22, the internal pressure of the working space 20 changes, and the power piston 4 reciprocates due to this pressure change. The reciprocating power rotates the crankshaft 10 of the piston crank mechanism 5, and the generator 11 generates electricity.

According to this embodiment, the following effects can be obtained.
(1) A heat exchanger 6 for exchanging heat between the working gas and the heat source gas. The heat exchanger 6 is arranged in a stacked state with a predetermined interval, and has a plurality of heat transfer layers alternately configured in the stacking direction of a working gas circulation layer 63 for circulating a working gas and a heat source gas circulation layer 64 for circulating a heat source gas. A plurality of working gas channels 671 and heat source gas channels 672 through which the working gas and the heat source gas flow are formed in the heat plate 60, the working gas circulation layer 63 and the heat source gas circulation layer 64 along the flow directions of the working gas and the heat source gas. and a flow path forming portion formed by the above (FIG. 3). The flow path forming portion constitutes boundaries between the plurality of working gas flow paths 671 and the heat source gas flow paths 672, and is composed of a plurality of heat transfer plates 60 and a plurality of heat transfer fins 60a integrally formed (Fig. 5).

This configuration enables the working gas flow path 671 and the heat source gas flow path 672 to have a fine capillary shape. For this reason, a high pressure difference can be achieved with a small wall thickness due to the capillary effect, and weight reduction is possible while ensuring pressure resistance. Further, for example, when metal plates are laminated by pressing, when heat transfer fins forming the boundary between the working gas flow path and the heat source gas flow path are attached between a pair of metal plates, the heat transfer fins work effectively. is said to be up to 10 times the thickness of the pressed heat transfer plate (metal plate). By integrally molding a plurality of heat transfer fins 60a and a plurality of heat transfer plates 60 by metal additive manufacturing, it is possible to make the thickness (width) of the heat transfer fins 10 times or less than the plate thickness of the heat transfer plates. , and the heat transfer fin can have higher heat transfer performance. In addition, since the number of parts and the number of assembling man-hours are reduced as compared with the case of forming by press working, cost reduction can be achieved.

(2) The heat transfer fins 60a are formed so that the equivalent diameters of the plurality of working gas flow paths 671 (heat source gas flow paths 672) formed in the working gas flow layer 63 (heat source gas flow layer 64) are equal to each other. (Fig. 5).

With this configuration, by equalizing the equivalent diameter of the working gas flow paths 671 (heat source gas flow paths 672), the pressure loss coefficients and heat transfer coefficients become equal, and each working gas flow path 671 (each heat source gas flow field 672) becomes There is no drift of the flowing working gas (heat source gas). Since the working gas (heat source gas) flowing through the working gas flow path 671 (heat source gas flow path 672) does not drift, the pressure loss as a whole is reduced and the heat transfer performance is improved.

(3) A plurality of working gas flow paths 671 (heat source gas flow paths 672 2.) A first inlet/outlet portion 61a (outlet portion 62a) configured to allow the working gas (heat source gas) entering and exiting from each flow direction end to enter and exit the heat exchanger 6 (FIG. 2). The first inlet/outlet portion 61a (outlet portion 62a) is provided in a direction intersecting with the flow direction of the working gas flow path 671 (heat source gas flow path 672), and is provided in the working gas circulation layer 63 (heat source gas circulation layer 64). In the plurality of working gas flow paths 671 (heat source gas flow paths 672) provided, the end positions of the working gas flow paths 671 (heat source gas flow paths 672) located closer to the first inlet/outlet portion 61a (outlet portion 62a) side. It is formed away from the axial end portion 65 (abutting portion 66) of the heat exchanger 6 (Fig. 4).

With this configuration, the working gas (heat source gas) discharged from the working gas flow path 671 (heat source gas flow path 672) located near the first inlet/outlet portion 61a (outlet portion 62a) moves in the axial direction of the heat exchanger 6. It is discharged at a position away from the end portion 65 (abutting portion 66). Therefore, the working gas (heat source gas) can be smoothly circulated toward the first inlet/outlet portion 61a (outlet portion 62a), and the heat exchange efficiency of the working gas (heat source gas) can be improved.

(4) The working gas flow path 671 (heat source gas flow path 672) has projections 60b projecting from the inner wall forming the working gas flow path 671 (heat source gas flow path 672) (FIG. 5). By providing the protrusion 60b on the inner wall, the flow of the working gas (heat source gas) flowing in the working gas flow path 671 (heat source gas flow path 672) is agitated by the vertical vortex flow, and the heat transfer coefficient can be improved. .

(5) The plurality of heat transfer fins 60a are integrally formed with the plurality of heat transfer plates 60 by metal additive manufacturing. With this configuration, the working gas flow path 671 and the heat source gas flow path 672 can be easily made into a fine capillary shape, and the number of parts and assembly man-hours are reduced as compared with the case of forming by press working. , the cost can be reduced.

In the above-described embodiment, by providing the protrusion 60b on the inner wall of the working gas flow path 671 (heat source gas flow path 672), the longitudinal vortex flow agitates and improves the heat transfer coefficient. By arranging a shaped member in the working gas channel 671 (heat source gas channel 672), the flow of the working gas (heat source gas) is disturbed and the heat transfer efficiency of the working gas (heat source gas) is improved. good. Similarly, a helical groove is provided in the working gas channel 671 (heat source gas channel 672) to disturb the flow of the working gas (heat source gas) and improve the heat transfer efficiency of the working gas (heat source gas). good too.

In the above embodiment, the plurality of working gas flow paths 671 and the heat source gas flow paths 672 are formed by partitioning them with the heat transfer fins 60a, but the present invention is not limited to this. For example, between a pair of heat transfer plates 60, 60, thin tubes extending in the axial direction may be arranged along opposing surfaces of the heat transfer plates 60, 60 to form the working gas flow path 671 and the heat source gas flow path 672. . The narrow tube is not limited to a circular tube, and may be a polygonal tube. By arranging the fine tubes between the pair of heat transfer plates 60 , 60 , the strength of the working gas flow path 671 or the heat source gas flow path 672 located in the heating section 67 can be improved.

In the above embodiment, the plurality of heat transfer fins 60a and the plurality of heat transfer plates 60 of the heat exchanger 6 are formed by integral molding using metal additive manufacturing, but the present invention is not limited to this. For example, the plurality of heat transfer fins 60a and the plurality of heat transfer plates 60 may be formed by laminating pressed metal plates.

The above description is merely an example, and the present invention is not limited by the above-described embodiments and modifications as long as the features of the present invention are not impaired. It is also possible to arbitrarily combine one or more of the above embodiments and modifications, and it is also possible to combine modifications with each other.

1 Stirling engine, 2 cylinder, 3 displacer piston, 4 power piston, 6 heat exchanger, 60 heat transfer plate, 60a heat transfer fin (flow passage forming part), 63 working gas flow layer (first flow layer), 671 operation Gas channel (channel), 64 heat source gas circulation layer (second circulation layer), 672 heat source gas channel (channel)

Claims (5)

A heat exchanger for exchanging heat between a first fluid and a second fluid,
a plurality of heat transfer plates which are arranged in a stacked state with a predetermined interval, and which alternately form a first circulation layer for circulating the first fluid and a second circulation layer for circulating the second fluid in the stacking direction;
Flow path formation in which a plurality of flow paths through which the first fluid or the second fluid flows are formed in the first flow layer and the second flow layer along the flow direction of the first fluid or the second fluid. and
The heat exchanger according to claim 1, wherein the flow passage forming portion constitutes a boundary between the plurality of flow passages and is composed of a plurality of heat transfer fins integrally formed with the plurality of heat transfer plates. The heat exchanger of claim 1, wherein
A heat exchanger, wherein the heat transfer fins are formed such that equivalent diameters of a plurality of flow paths formed in the first flow layer and the second flow layer are equal to each other. In the heat exchanger according to claim 1 or 2,
The first fluid, which is provided corresponding to the first flow layer and flows in and out of the flow direction end of each of the plurality of flow paths provided in the first flow layer, can flow in and out of the heat exchanger. further comprising an entrance and exit section,
The inlet/outlet part is provided in a direction intersecting with the flow direction of the first flow path,
The plurality of first flow passages provided in the first circulation layer are formed so that the end positions of the first flow passages located closer to the inlet/outlet portion are farther away from the end portions in the flow direction of the heat exchanger. A heat exchanger characterized by: In the heat exchanger according to any one of claims 1 to 3,
A heat exchanger according to claim 1, wherein the flow path is provided with a protrusion projecting from an inner wall forming the flow path. In the heat exchanger according to any one of claims 1 to 4,
A heat exchanger according to claim 1, wherein said plurality of heat transfer fins are integrally formed with said plurality of heat transfer plates by a metal additive manufacturing method.

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