JPH11337205A - Sound refrigerating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound refrigerating device to produce refrigeration efficiency higher than that of a conventional device. SOLUTION: First and second sound wave generating device 6 and 63 are mounted on the line of a hollow annular sound tube 1 having a peripheral length being integer times the wavelength of a sound wave in a state that the two device are separated away from each other by a distance an odd number times the 1/4 wavelength of a sound wave. Further, third and fourth sound generating devices 64 and 65 are mounted opposite to the first and second sound generating devices 6 and 63, respectively. Further, a cold storage apparatus 4 is mounted on the sound tube 1. The first - fourth sound generating devices 6, 63, 64, and 65 receive a signal from a drive source 5. A first sound wave outputted and first sound waves outputted from the first and third sound wave generating devices 6 and 63 form an iso-phase and second sound waves outputted from the second and fourth sound wave generating devices 63 and 65 form an iso-phase, and drive and control is effected such that the phases of the first and second sound waves are deviated from each other only by an amount being increased an odd number times 1/4 wavelength of the sound wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic refrigeration apparatus, and more particularly to an acoustic refrigeration apparatus capable of realizing a gas cycle close to a Carnot cycle.

[0002]

2. Description of the Related Art Conventionally, there is known an acoustic refrigeration apparatus for refrigeration using sound waves (see, for example, Japanese Patent Publication No. 3-46745). For example, an acoustic refrigerator (200) shown in FIG.
(A) is closed, and the other end (202B) is provided with a resonance tube (202) having an opening, and a speaker (201) for generating sound is provided facing the open end (202B) of the resonance tube (202). And resonance tube (202)
Inside, a regenerator (203) in which flat plates are arranged in a plurality of layers is provided.

Here, the frequency of the current applied to the speaker (201) is set to a value at which sound waves resonate in the resonance tube (202). From the speaker (203) to the closed end of the resonance tube (202)
When a sound wave is generated toward (202A), a pressure distribution P is formed in the resonance tube (202) as shown in FIG. And occur alternately. Further, as shown by an arrow W in the figure, the gas displacement also has an antinode and a node. As a result, the regenerator (20
3) Temperature difference occurs at both ends. Then, the low-temperature end and the high-temperature end of the regenerator (203) perform cooling of the object and heat radiation to the outside via a heat exchanger (not shown), respectively.

The above-described acoustic refrigeration apparatus (200) can be described by a Brayton cycle consisting of four steps of adiabatic compression, isobaric pressure change, adiabatic expansion, and isobaric pressure change of a minute gas mass. However, in the Brayton cycle constituted by the acoustic refrigerator (200),
Heat is absorbed by the difference between the temperature when the gas mass expands and the temperature of the regenerator (203), or is released by the difference between the temperature when the gas mass is compressed and the temperature of the regenerator (203). Therefore, the thermal transfer process is irreversible, and has a disadvantage that the thermal efficiency is lower than that of the Carnot cycle.

Therefore, the applicant has proposed an acoustic refrigeration apparatus in which the thermal transfer process is reversible and a gas cycle close to an ideal gas cycle, the Carnot cycle, can be realized (Japanese Patent Application No. Hei 9-1997). 134993). Based on FIGS. 2 to 7,
The basic structure and principle of the acoustic refrigerator will be described.

As shown in FIG. 2, an acoustic tube 1 through which a sound wave is to be transmitted forms a hollow annular closed loop conduit. The circumference of the acoustic tube (1) is set to be an integral multiple of the wavelength of the sound wave. In the following example, the length of the center line of the acoustic tube (1) is defined as the circumference. Speaker as sound wave generator
(2) and (3) are attached to the acoustic tube (1) so as to emit acoustic waves into the acoustic tube (1) while being separated from each other by a distance equal to an odd multiple of 音波 wavelength of the acoustic wave. Also, speaker (2)
A sound wave generation control device (50) is connected to (3), and a speaker
(2) The phases of the sound waves emitted from (3) are 1 /
Drive control is performed so as to shift by an odd multiple of four wavelengths.

Next, the operation principle of the acoustic refrigerator is described.
This will be described with reference to FIG. The sound waves radiated from the speakers (2) and (3) enter the acoustic tube (1), branch in two directions, and travel in the acoustic tube (1). And both speakers (2)
Two sound waves emitted from (3) and traveling in the acoustic tube (1) overlap each other. Here, from the relationship between the arrangement intervals of the speakers (2) and (3) and the phase difference between the sound waves, the sound waves 2L and 3L traveling to the left in the drawing have the same phase, are superimposed on each other and amplified, and The sound waves 2R and 3R traveling in the directions have opposite phases and cancel each other. As a result, only the sound wave traveling in one direction (left direction) remains, and the sound wave further goes around in the acoustic tube (1) and is superimposed with the sound wave of the same phase, so that the amplitude is increased similarly to the resonance. Will be.

Next, as shown in FIG. 4, the principle of refrigeration when a regenerative member (40) having good heat exchange and a small pressure loss is provided in an acoustic tube (1) of an acoustic refrigeration apparatus will be described with reference to FIG. This will be described with reference to FIG. The traveling sound wave passing through the cold storage member (40) has a phase shift depending on its position, and when focusing on a minute gas mass located at a certain position, an expansion stroke occurs in the traveling direction of the sound wave at the center position as a boundary. In the opposite direction, a compression stroke occurs. In the expansion step and the compression step, heat is absorbed and released using the cold storage member (40), so that heat is sequentially transferred in the direction opposite to the traveling direction of the sound wave. Since the heat transfer process is reversible, the heat efficiency is higher than that of the conventional acoustic refrigerator.

Further, a gas cycle of the acoustic refrigerator according to the present invention will be described with reference to FIGS. The Carnot cycle is composed of an isothermal process and an adiabatic process, and is shown as a rectangular cycle diagram of AHGD in the TS diagram as shown in FIG. Here, A → H indicates an adiabatic expansion stroke (constant entropy), H → G indicates an isothermal expansion stroke, G → D indicates an adiabatic compression stroke, and D → A indicates an isothermal expansion stroke.

As shown in FIG. 7, when a sound wave passes in one direction through a regenerative member having good heat conductivity as a gas mass, the minute gas mass reciprocates and changes pressure at the same time. The pressure change, when the gas mass has moved the most in the sound wave traveling direction,
The pressure rises quickly and is strongly compressed. Here, since the heat storage member has good heat conductivity, isothermal compression is performed. This isothermal compression stroke is indicated by D → A in FIGS. Next, when the gas mass moves in the direction opposite to the sound wave traveling direction, heat is released along the temperature gradient of the cold storage member,
The gas mass is cooled by a substantially equal volume change. This process is indicated by AB in FIGS.

Thereafter, at the end in the direction opposite to the traveling direction of the sound wave, the pressure decreases rapidly and expands strongly. At this time, an isothermal expansion process in which heat is absorbed from the cold storage member is performed.
This process is indicated by B → C in FIGS. 6 and 7.
Even when the gas moves in the direction in which the sound wave travels, there is an equal volume change that absorbs heat along the temperature gradient of the cold storage member. This process is indicated by C → D in FIGS. 6 and 7.

From the above, D → A → B → C → shown in FIG.
One cycle of D makes it possible to transfer heat in the direction opposite to the direction of sound wave travel. Thus, a cycle constituted by the isothermal process and the isostatic process is called a Stirling cycle, and the adiabatic process of the Carnot cycle is an isostatic process. Therefore, according to the acoustic refrigeration apparatus, efficiency equivalent to the Carnot cycle can be obtained.

[0013]

However, in the acoustic refrigerating apparatus shown in FIG. 2, sound waves emitted from the speakers (2) and (3) are first transmitted to the acoustic tubes (2) and (3). The light impinges perpendicularly on the inner wall of 1) and is reflected on the wall. Since this reflection hinders the formation of the traveling sound wave, there is a problem that the refrigeration efficiency of the acoustic refrigerator is lower than the efficiency to be obtained in the Carnot cycle. An object of the present invention is to provide an acoustic refrigeration apparatus that can achieve a higher refrigeration efficiency than before.

[0014]

According to the present invention, there is provided an acoustic refrigeration apparatus, comprising: a first sound wave generating means and a second sound wave generating means which face a hollow annular sound pipe whose circumference is an integral multiple of the wavelength of a sound wave; The sound wave generating means is arranged at an interval of an odd multiple of 1/4 wavelength of the sound wave, and a cool storage member is provided at a predetermined position in the acoustic tube. A sound wave generation control means is connected to the first sound wave generation means and the second sound wave generation means, and the phase of the first sound wave emitted from the first sound wave generation means and the phase of the second sound wave emitted from the second sound wave generation means are changed. The operation of both sound wave generating means is controlled so as to differ by an odd multiple of の wavelength. In the characteristic configuration of the present invention, each of the first sound wave generator and the second sound wave generator is constituted by a pair of sound wave generators opposed to each other across a pipe of the acoustic tube, and the pair of sound wave generators is Control is performed so as to generate sound waves of the same phase.

In the above-described acoustic refrigerator of the present invention, the first
When a sound wave is emitted from the sound wave generating means and the second sound wave generating means into the acoustic tube, the sound wave branches in two directions in the acoustic tube and proceeds. At this time, a pair of sound wave generators constituting each sound wave generator emits sound waves of the same phase. Then, these sound waves are combined with each other to generate a sound wave traveling along the acoustic tube.

Thereafter, the phase of the first sound wave emitted from the first sound wave generating means and the phase of the second sound wave emitted from the second sound wave generating means are determined in one direction based on the interval between the two sound wave generating means and the phase of the generated sound waves. The sound wave traveling to the other direction is superposed and amplified, and the sound wave traveling to the other direction is canceled. For this reason, only the sound wave traveling in one direction remains in the sound tube, and is further rotated by one turn in the sound tube and superimposed with the sound wave of the same phase, so that the amplitude is increased like resonance.

When the sound wave formed in this manner and traveling in only one direction passes through the regenerative member, the pressure and displacement of the minute gas mass located at each location causes a phase shift depending on the location. As a result, the gas mass located at each location expands when located in the traveling direction of the sound wave, and compresses when located in the opposite direction, from the center position of the displacement. In the expansion stroke and the compression stroke, heat is absorbed and released, so that heat is sequentially transferred in the direction opposite to the direction in which the sound wave travels. As a result, the heat transfer process is performed reversibly, and a heat cycle close to the Carnot cycle is realized.

[0018]

According to the acoustic refrigerator of the present invention,
Sound waves radiated from a pair of sound wave generators arranged opposite to each other are combined to generate a sound wave traveling along the acoustic tube, so that a refrigerating efficiency extremely close to the efficiency of the Carnot cycle can be obtained.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. As shown in FIG. 1, the acoustic refrigeration apparatus according to the present invention includes an acoustic tube (1) having a hollow annular closed-loop conduit, and a circumference of the acoustic tube (1) is
It is set to be an integral multiple of the wavelength of the sound wave.

A first sound generator (6) and a second sound generator (63) are attached to the acoustic tube (1) so as to be separated from each other by a distance equal to an odd multiple of 1/4 wavelength of the sound wave. I have.
Also, the sound tube (1) is opposed to the first sound wave generator (6) and the second sound wave generator (63), respectively, and the third sound wave generator (64) and the fourth sound wave generator (65). Is attached. Thus, the first sound wave generator (6) and the third sound wave generator (64) constitute the first sound wave generator, and the second sound wave generator (63) and the fourth sound wave generator (65). ) Constitute the second sound wave generating means. These sound wave generators (6) (63) (64) (65) are linear motors (6
A diaphragm (61) is connected to the output unit of (2), and a sound wave is emitted into the acoustic tube (1) by reciprocatingly driving the diaphragm (61) by driving the linear motor (62).

A regenerator (4) is mounted at an appropriate position on the acoustic tube (1). The regenerator (4) is a regenerative member composed of a wire mesh laminate or porous body made of a material having high thermal conductivity such as copper, copper alloy, iron, stainless steel, or a plurality of parallel plates. (Not shown).

The first to fourth sound wave generators (6), (63), (64)
(65) receives the drive control signal from the drive source (5), the sound waves (first sound waves) emitted from the first sound wave generator (6) and the third sound wave generator (64) have the same phase, Sound waves (second sound waves) emitted from the second sound wave generator (63) and the fourth sound wave generator (65) have the same phase, and the first sound wave generator
(6) and the phase of the first sound wave emitted from the third sound wave generator (64), and the second sound wave generator (63) and the fourth sound wave generator
Drive control is performed such that the phase of the second sound wave emitted from (65) is shifted from each other by an odd multiple of 1/4 wavelength of the sound wave.

In the above acoustic refrigerator, the first to fourth
When sound waves are emitted from the sound wave generators (6) (63) (64) (65) into the acoustic tube (1), the same sound waves are generated from the first sound wave generator (6) and the third sound wave generator (64). The sound waves in phase are combined with each other, thereby generating two sound waves (first sound waves) traveling in opposite directions along the acoustic tube. Also, the sound waves having the same phase emitted from the second sound wave generator (63) and the fourth sound wave generator (65) are combined with each other, so that they travel in opposite directions along the acoustic tube. Two sound waves (second sound waves) are generated.

After that, the first sound wave and the second sound wave are superposed and amplified by the sound waves traveling in one direction, and the sound waves traveling in the other direction are canceled out, so that only the sound waves traveling in one direction enter the acoustic tube. Remaining, further round the inside of the acoustic tube and superimposed with sound waves of the same phase, and the amplitude will be increased like resonance

The sound wave formed in this way, which travels in only one direction, passes through the regenerator (4).
The gas mass located at each location in (4) expands when it is located in the traveling direction of the sound wave, and compresses when it is located in the opposite direction from the center position of the displacement. In the expansion stroke and the compression stroke, heat absorption and heat release are performed, and a heat cycle close to a Carnot cycle is realized. As a result, higher refrigeration efficiency than the conventional acoustic refrigeration apparatus shown in FIG. 8 can be obtained.

In particular, in the acoustic refrigerator according to the present invention, the two sound waves emitted from the first sound wave generator (6) and the third sound wave generator (64) are combined with each other and the second sound wave traveling in two directions is obtained. One sound wave is generated, and two sound waves emitted from the second sound wave generator (63) and the fourth sound wave generator (65) are combined with each other to generate a second sound wave traveling in two directions. However, unlike the related art, there is no problem caused by the sound waves emitted from the sound wave generator being reflected on the facing wall surface. Therefore, higher refrigeration efficiency than the acoustic refrigeration apparatus shown in FIG. 2 is realized.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, a first sound wave generator constituted by a first sound wave generator (6) and a third sound wave generator (64), a second sound wave generator (63) and a fourth sound wave generator
The second sound wave generating means constituted by (65) can be disposed at a plurality of positions shifted by an odd multiple of 1/4 wavelength of the sound wave, thereby adding to each sound wave generating device. The load can be reduced, and the life of the acoustic refrigerator can be extended. The generation of sound waves is not limited to the sound wave generator driven by the linear motor as described above, but a loudspeaker driven by electromagnetic force, a vibration unit using a piezoelectric element as a vibration source, or the like can be employed. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a basic structure of an acoustic refrigerator according to the present invention.

FIG. 2 is a first diagram for explaining the operation principle of the acoustic refrigerator according to the proposal of the applicant.

FIG. 3 is a second diagram of the above.

FIG. 4 is a schematic diagram showing a basic structure of the acoustic refrigerator.

FIG. 5 is a diagram for explaining a heat transfer process of the acoustic refrigerator.

FIG. 6 shows a TS representing a refrigeration cycle of the acoustic refrigerator.
FIG.

FIG. 7 is a diagram for explaining the refrigeration cycle.

FIG. 8 is a sectional view of a conventional acoustic refrigerator.

[Explanation of symbols]

 (1) Acoustic tube (2) Speaker (3) Speaker (4) Cold storage (40) Cold storage member (5) Drive source (6) First sound wave generator (63) Second sound wave generator (64) Third sound wave Generator (65) Fourth sound generator (61) Diaphragm (62) Linear motor

Claims (2)

[Claims] 1. A first sound wave generating means and a second sound wave generating means, which face a pipe of a hollow annular acoustic tube whose circumference is an integral multiple of the wavelength of a sound wave.
The sound wave generating means is disposed at an interval of an odd multiple of 1/4 wavelength of the sound wave, and a cool storage member is provided at a predetermined position in the acoustic tube, and the first sound wave generating means and the second sound wave generating means are provided with sound waves. The generation control means is connected to generate both sound waves such that the phases of the first sound wave emitted from the first sound wave generation means and the second sound wave emitted from the second sound wave generation means differ by an odd number times 1/4 wavelength of the sound wave. An acoustic refrigerator for controlling the operation of the means, wherein each of the first sound wave generating means and the second sound wave generating means is constituted by a pair of sound wave generating apparatuses opposed to each other with a pipe of the acoustic tube interposed therebetween, and An acoustic refrigerator, wherein the sound wave generator is controlled so as to generate sound waves having the same phase. 2. The acoustic refrigerator according to claim 1, wherein the first sound wave generating means and the second sound wave generating means are arranged at a plurality of positions of the acoustic tube while being shifted by an odd multiple of １ ／ wavelength of the sound wave. apparatus.