JP2012047440A - Stack, manufacturing method thereof, and heat-acoustic device using the stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture, at low costs, a stack capable of executing efficient energy exchange between sound energy and heat energy.SOLUTION: A stack 4, for executing energy exchange between sound energy and heat energy in a loop tube 1, comprises an assembly of a plurality of thin-tube glasses G arranged in parallel along a tube axis in the loop tube 1. The plurality of thin-tube glasses G is held in the loop tube 1 in a contact state without being mutually welded.

Description

  The present invention relates to a stack used in a thermoacoustic device and the like and a manufacturing method thereof, and more particularly, to a stack for exchanging energy between thermal energy and sound energy and a manufacturing method thereof.

  As is well known, a thermoacoustic device is a device that converts energy between sound energy and heat energy, and for example, cools an object to be cooled using waste heat of a factory or an automobile. What has been constructed has been proposed and has attracted attention as a clean cooling mechanism.

  As shown in FIG. 1, this type of thermoacoustic apparatus includes a loop tube 1 in which a gas (fluid) such as helium or neon is enclosed, a high temperature side heat exchanger 2 a provided on one side of the loop tube 1, and a low temperature. The first stack 4a sandwiched between the side heat exchanger 3a and the second stack 4b disposed on the other side of the loop pipe 1 and sandwiched between the high temperature side heat exchanger 2b and the low temperature side heat exchanger 3b And. Both the stacks 2 a and 2 b have a plurality of flow paths communicating in the tube axis direction of the loop pipe 1.

  The operation principle of the thermoacoustic apparatus having such a configuration is as follows.

  First, the high temperature side heat exchanger 2a on the first stack 4a side is heated by inputting factory waste heat or automobile waste heat and the like, and a coolant (cooling water, liquid nitrogen, etc.) is supplied to the low temperature side heat exchanger 3a. Is circulated and cooled to form a temperature gradient between the high temperature side heat exchanger 2a and the low temperature side heat exchanger 3a. As a result, the fluid in the flow path of the first stack 4a sandwiched between the heat exchangers 2a and 3a (such as the enclosed helium) starts to fluctuate. Will occur. When the self-excited sound wave is generated in this way, the sound wave propagates along the loop tube 1 and is input as sound energy to the second stack 4b disposed on the other side of the loop tube 1. In the second stack 4b to which the sound energy is input, the fluid repeatedly expands and contracts in the flow path, and the heat accumulated in the fluid in the process is applied to the wall surface constituting the flow path of the second stack 4b. Released. The released heat is transferred in the direction opposite to the direction of sound energy transfer, that is, transferred from the low-temperature side heat exchanger 3b toward the high-temperature side heat exchanger 2b. 3b is cooled, and an external cooling object is cooled using the cooled low temperature side heat exchanger 3b.

  By the way, various stacks have been proposed for use in this type of thermoacoustic apparatus. For example, Patent Document 1 discloses a stack that is formed of a material having a large heat capacity such as ceramics, sintered metal, wire mesh, and metal nonwoven fabric, penetrates in the tube axis direction of the loop tube, and functions as a flow path. Etc. are disclosed.

JP 2005-274099 A

  However, among these stacks, metal stacks generally have high thermal conductivity, so when a self-excited sound wave is generated using the stack, the temperature gradient between both ends of the stack cannot be maintained large. There is a problem that self-excited sound waves cannot be generated quickly.

  Further, in both cases of generating self-excited sound waves using a stack and converting sound energy into heat energy, sound energy and heat energy are increased as the number of distribution channels in the stack is increased. However, in the case of stacks made of metal or ceramics, it is difficult to increase the number of distribution channels, and there is a problem that the manufacturing cost increases.

  In particular, ceramic stacks are typically formed with pores that function as distribution channels by injection molding, so it is technically difficult to form minute holes. That is, when trying to reduce the diameter of the porous holes formed in the stack, there is a possibility that the material extruded at a high temperature at the time of injection closely adheres within the holes, causing clogging and closing the flow path. In addition, even in the subsequent firing step, the flow path may be deformed by heat shrinkage, and the heat conversion efficiency in the stack may be reduced.

  In view of the above circumstances, an object of the present invention is to manufacture a stack capable of efficiently exchanging energy between sound energy and thermal energy at a low cost.

  The present invention created in order to solve the above problems is a stack arranged in a pipe and exchanging energy between sound energy and thermal energy in the pipe. It consists of the aggregate | assembly of the thin tube glass arranged in parallel, It is characterized by the said several thin tube glass being hold | maintained in the said tube in the state which contacted without mutually welding.

  According to such a configuration, since the stack is formed from an aggregate of thin tube glass, the thermal conductivity of the stack can be suppressed lower than when the stack is formed of metal or the like. Therefore, when a self-excited sound wave is generated using the stack, the temperature gradient between both ends of the stack can be maintained large, and the self-excited sound wave can be generated quickly.

  Moreover, since the manufacturing technology of thin tube glass is an established technology, in order to increase the number of distribution channels, it is technically easy to reduce the outer diameter and inner diameter of the thin tube glass. Therefore, if the stack is composed of an assembly of a plurality of thin tube glasses, the number of distribution channels communicating with both ends of the stack can be easily increased.

  Furthermore, since a plurality of capillary tubes constituting the stack are held in the tube in contact with each other without being welded to each other, after a capillary tube having a predetermined length is manufactured using existing technology, A stack can be produced simply by inserting into a tube without any special processing of the thin tube glass. Therefore, it is possible to reliably reduce the manufacturing cost of the stack. In addition, you may make it adhere | attach the outer peripheral surfaces of a thin tube glass using an adhesive agent, and it may insert in a pipe | tube.

Said structure WHEREIN: While the said several thin tube glass is arrange | positioned in the said tube in the ratio of 300 pieces / inch < ² > or more, the glass part of the said several thin tube glass in the axial orthogonal cross section of the inner hole of the said pipe | tube The occupation ratio is preferably less than 50%.

In other words, if a plurality of thin glass tubes are arranged at a rate of 300 / inch ² or more in the tube, the distribution channel of the stack is appropriately subdivided, and energy exchange between sound energy and heat energy is performed. It becomes possible to carry out efficiently. Even in this case, if the proportion of the glass portion is too large, the distribution path becomes too narrow and the energy conversion efficiency may be reduced. Therefore, the occupancy ratio of the glass portion of the plurality of thin tube glasses in the cross section perpendicular to the axis of the inner hole of the tube is preferably less than 50%. Since the size of the hole can be ensured without any problem, the energy exchange efficiency can be maintained satisfactorily.

  In the above configuration, a gap communicating in the tube axis direction of the tube may be formed between the non-contact portions of the outer peripheral surface of the plurality of thin tube glasses.

  In this way, the gap formed between the non-contact portions of the outer peripheral surface of the plurality of thin tube glasses functions as a flow path that communicates in the tube axis direction like the inner hole of each thin tube glass. it is conceivable that. Therefore, improvement in the efficiency of energy exchange between sound energy and heat energy can be expected. In this case, when the outer peripheral surfaces of the thin tube glass are bonded to each other using an adhesive as described above, the gap formed between the non-contact portions of the outer peripheral surface of the thin tube glass is not blocked with the adhesive. It is necessary to do so.

  You may comprise a thermoacoustic apparatus using the stack | stuck provided with said structure suitably. That is, a thermoacoustic apparatus in which two high-temperature side heat exchangers and low-temperature side heat exchangers are each provided with a stack having the above-described configuration appropriately sandwiched between two spaced locations in a loop tube, A self-excited sound wave is generated by applying a temperature gradient to the stack on the side, and cooling of the low-temperature side heat exchanger attached to the stack on the other side by the sound wave and the second high-temperature side heat exchanger It is good also as a structure which performs at least one of a heating.

  In order to solve the above-mentioned problems, the present invention provides a stack manufacturing method in which a plurality of thin glass tubes are disposed in a tube in a tube and in which energy is exchanged between sound energy and heat energy. It is characterized in that it is inserted in a posture along the tube axis and arranged in parallel in the tube, and the plurality of thin tube glasses in the tube are held in contact with each other without being welded to each other.

  According to such a method, it is possible to receive the same operational effects as the corresponding configuration already described.

  In the above method, it is preferable that the plurality of thin glass tubes are formed by a redraw method.

  In this way, a very thin capillary glass can be manufactured stably and accurately.

  As described above, according to the present invention, a stack capable of efficiently exchanging energy between sound energy and heat energy can be manufactured at low cost.

It is the schematic which shows the whole structure of a thermoacoustic apparatus. It is a perspective view which shows the stack which concerns on embodiment of this invention. It is the enlarged view to which the area | region shown with the code | symbol X of FIG. 2 was expanded. It is the schematic which shows the whole structure of another thermoacoustic apparatus.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The thermoacoustic apparatus according to this embodiment is different from the thermoacoustic apparatus described in the related art only in the structure of the stack 4 (4a, 4b). Detailed description of the overall configuration of the acoustic device is omitted.

  As shown in FIG. 2, the stack 4 applied to the thermoacoustic device according to the present embodiment is composed of an aggregate of thin tube glasses G in which a plurality of tubes are arranged in parallel along the tube axis in the loop tube 1.

  The individual thin glass tubes G constituting the aggregate are held in a tube constituting a part of the loop tube 1 in a state where they are in contact with each other without welding. In this case, firstly, the thermal conductivity can be suppressed lower than that in the case where the stack is formed of metal or the like, and therefore, when the stack 4 is used to generate self-excited sound waves (FIG. 1). When the first stack 4a is used, the temperature gradient between both ends of the stack 4 can be maintained large, and self-excited sound waves can be generated quickly. Second, since the manufacturing technology of the thin tube glass G is an established technology, it is technically easy to reduce the outer diameter and the inner diameter of the thin tube glass G in order to increase the number of distribution channels. Therefore, if the stack 4 is composed of an assembly of a plurality of thin glass tubes G, the number of distribution channels communicating with both ends of the stack 4 can be easily increased. Thirdly, since the plurality of thin glass tubes G constituting the stack 4 are held in the tube in a state where they are in contact with each other without being welded to each other, the thin tube glass G having a predetermined length using existing technology. After manufacturing the stack 4, the stack 4 can be manufactured simply by inserting the thin tube glass G into the loop tube 1 without any special processing. Accordingly, it is possible to reliably reduce the manufacturing cost of the stack 4.

A plurality of thin glass tubes G constituting the stack 4 are arranged in the loop tube 1 at a rate of 300 pieces / inch ² or more. In this way, the distribution path of the entire stack 4 is appropriately subdivided according to the number of inner holes of the thin tube glass G, and it is possible to efficiently exchange energy between sound energy and heat energy. Become. The thin glass tube G is preferably arranged in the loop tube 1 at a rate of 500 / inch ² or more, more preferably 1000 / inch ² or more, and 2000 Most preferably, they are arranged at a ratio of / inch ² or more.

Furthermore, in the cross section perpendicular to the axis of the inner hole of the loop tube 1 at the position where the stack 4 is disposed, the occupation ratio of the glass portions of the plurality of thin glass tubes G constituting the stack 4 is less than 50%. That is, even when the thin tube glass G is arranged in the loop tube 1 at a rate of 300 / inch ² or more, if the proportion of the glass portion is too large, the distribution channel becomes extremely narrow, and sound energy and heat energy are reduced. Loss can occur in energy conversion between the two. Therefore, in the cross section perpendicular to the inner hole of the loop tube 1 at the position where the stack 4 is disposed, the occupation ratio of the glass portions of the plurality of thin tube glasses G is preferably less than 50%. If it is within the range, the size of the inner hole of the glass tube that can serve as a distribution channel can be ensured without any problem, so that the energy exchange efficiency can be maintained satisfactorily. In addition, it is preferable that the occupation rate of the glass part of the thin tube glass G is less than 40%, and it is more preferable that it is less than 30%.

  Here, since the plurality of thin glass tubes G constituting the stack 4 are held in the loop tube 1 without being welded to each other as described above, the outer peripheral surfaces are in contact with each other as shown in FIG. Between the outer peripheral surfaces of the thin glass tubes G held in a state, a gap S whose periphery is closed by a non-contact portion of the outer peripheral surfaces of the three to five thin tube glasses G is formed. Since these voids S communicate with each other in the tube axis direction of the loop tube 1, it is considered that they function as a flow path like the inner hole of the thin tube glass G, and energy exchange between sound energy and heat energy is performed. It can contribute to the improvement of efficiency. The shape of the gap S varies depending on the combination of the thin tube glass G and exhibits a shape different from the circular shape of the inner hole of the thin tube glass G. Therefore, when the space | gap S functions as a distribution channel, it is comprised by the inner hole of the thin tube glass G, and the space | gap S from a thing with at least 2 or more types of different distribution channels.

  The strain point of the thin tube glass G constituting the stack 4 is 350 ° C. or higher. That is, if the thin glass tube G has a strain point of 350 ° C. or higher, a high-temperature heat source such as factory waste heat can be used as it is without being cooled. Therefore, since the input heat energy can be kept large, the sound energy obtained by converting this heat energy by the stack 4 can also be kept large, which is efficient. Specifically, as the glass composition of the thin tube glass G, soda lime glass, borosilicate glass, lead glass, or the like is used.

  The stack 4 configured as described above is manufactured as follows.

  First, a long glass tube is formed by stretching while heating the base glass by a redraw method. Next, this long thin tube glass is cut into a predetermined length to produce a plurality of thin tube glasses G constituting the stack 4. In this case, each thin tube glass G is formed of a fire-making surface in which the inner diameter and the outer diameter are substantially the same in the tube axis direction, and the inner and outer surfaces are smooth.

  Next, the plurality of cut thin glass tubes G are inserted into a tube constituting a part of the loop tube 1 in an independent state without being welded to each other so that the longitudinal direction is directed to the tube axis direction. Are arranged in parallel. And the stack 4 is manufactured by hold | maintaining in a pipe | tube in the state which mutually contacted the several thin tube glass G, without welding as it is.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above-described embodiment, the case where the stack 4 is held in the loop tube 1 has been described. However, the stack 4 is held in a non-loop tube (open tube) having an end, such as a straight tube, so that the thermoacoustic apparatus It may be configured.

  As examples 1 to 3, a stack constituted by contacting the thin tube glass without being welded to each other and being held in the loop tube is produced, and as a comparative example, a stack made of porous alumina is produced, The acoustic intensity when each stack was applied to the thermoacoustic apparatus shown in FIG. 1 was evaluated. The results are shown in Table 1 below. Note that the sound intensity is relatively represented by using a sound having a frequency of 523 Hz, and the result of the comparative example is 1.0.

  According to Table 1, it can be confirmed that in Examples 1 to 3, the sound intensity is greatly improved as compared with the comparative example constituted by alumina. In other words, it can be confirmed that a stack made of an aggregate of glass tubes can convert heat energy into sound energy more efficiently than an alumina stack.

  In addition, the stack used in Example 1 and the comparative example is arranged in the experimental system shown in FIG. The temperature before and after the stack was measured with a thermocouple arranged in advance, and the temperature difference before and after the stack was obtained from both values. The results are shown in Table 2.

  According to Table 2, regardless of the distance from the speaker of the stack, it can be confirmed that Example 1 has a larger temperature difference before and after the stack than the comparative example made of alumina. In other words, it can be confirmed that a stack made of an aggregate of glass tubes can convert heat energy into sound energy more efficiently than an alumina stack.

  Furthermore, the stack used in Example 1 and Example 3 is arranged in the experimental system shown in FIG. 4, the distance from the speaker of the stack is 185 mm, the sound of the frequency 105 Hz is emitted from the speaker, and the temperature before and after the stack is set. The temperature was measured with a thermocouple arranged in advance, and the temperature difference before and after the stack was determined from both values. The results are shown in Table 3.

  According to Table 3, it can be confirmed that Example 1 has a larger temperature difference before and after the stack than that of Example 3. In other words, it can be confirmed that a stack made of an aggregate of glass tubes with more distribution channels can efficiently convert heat energy into sound energy.

1 Loop tube 2a, 2b High temperature side heat exchanger 3a, 3b Low temperature side heat exchanger 4 (4a, 4b) Stack G Thin tube glass S Gap

Claims (6)

In a stack arranged in a tube and exchanging energy between sound energy and heat energy in the tube,
A plurality of thin tube glasses arranged in parallel along the tube axis in the tube, and the plurality of thin tube glasses are held in the tube in contact with each other without being welded to each other. Feature stack. The plurality of thin tube glasses are arranged in the tube at a rate of 300 / inch ² or more, and the occupancy ratio of the glass portions of the plurality of thin tube glasses in the cross section perpendicular to the axis of the inner hole of the tube is 50. The stack of claim 1, wherein the stack is less than%.   The stack according to claim 1 or 2, wherein a gap communicating in the tube axis direction of the tube is formed between non-contact portions of the outer peripheral surface of the plurality of thin tube glasses.   The stack according to any one of claims 1 to 3 is arranged in a state of being sandwiched between a high temperature side heat exchanger and a low temperature side heat exchanger at two spaced locations in the loop pipe, A self-excited sound wave is generated by applying a temperature gradient to the stack, and cooling of the low temperature side heat exchanger attached to the stack on the other side and heating of the second high temperature side heat exchanger are generated by the sound wave. A thermoacoustic apparatus that performs at least one of the following. In a manufacturing method of a stack which is arranged in a tube and performs energy exchange between sound energy and heat energy in the tube,
A plurality of thin tube glasses are inserted into the tube in a posture along the tube axis and arranged in parallel in the tube, and the plurality of thin tube glasses are held in contact with each other without being welded to each other. A manufacturing method of a stack characterized by the above.   6. The stack manufacturing method according to claim 5, wherein the plurality of thin glass tubes are formed by a redraw method.

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