JP2714155B2 - Cooling room - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention relates to a cooling box for cooling the inside of the box.

(Prior art) Conventionally, refrigerators and freezers (both are equivalent to refrigerators)
Uses a vapor compression refrigeration cycle using a chlorofluorocarbon-based refrigerant to cool the inside of the refrigerator.

(Problems to be Solved by the Invention) By the way, refrigerators and freezers are required to be small, low noise, low vibration, and high cooling efficiency.

However, since the vapor compression type refrigeration cycle includes a compressor having a driving source such as a motor, a condenser, an expansion valve (or a throttle device), and an evaporator as components, it is difficult to reduce the size of the refrigeration cycle. Particularly, it is not suitable for a small-sized device. In addition, since the refrigerant flows through a closed loop cycle in various states of liquid, gas, and two phases of liquid and gas, a large amount of airflow noise with a large sound pressure is generated. Specifically, airflow noise at a level higher than the noise of the compressor was sometimes generated.

In addition, Freon-based refrigerants mainly used in refrigerators and freezers have recently been subject to Freon regulations because they cause environmental pollution such as destruction of the ozone layer, and will not be used in the future. Manufacturers are actively developing new refrigerants, but they have a better coefficient of performance (cycle efficiency) than currently used refrigerants. It is said that it will still take quite a while.

Under these circumstances, a freezer and a refrigerator capable of satisfying the above demands are demanded.

This occurrence was made by paying attention to such circumstances, and the purpose is to perform a cooling operation without using a CFC-based refrigerant, and to reduce the size, reduce noise, reduce vibration, It is still another object of the present invention to provide a cooler excellent in high cooling efficiency.

[Configuration of the Invention] (Means for Solving the Problems) In order to achieve the above object, a refrigerator according to the present invention comprises:
A cooling chamber body including a housing section for housing the object to be cooled and a cool air passage serving as a passage for circulating cool air through the housing section, and a surface layer portion formed of a metal material; And a Stirling refrigerator provided with a low-temperature heat exchanger located in the cold air passage while connecting a high-temperature heat exchanger to the metal material forming the surface layer portion of And

The cooling box body has an opening / closing door on the front side and the housing section and the cold air passage in the depth direction from the opening / closing door in order, and the Stirling refrigerator has the cooling air passage and the cooling box body. It is preferably provided between the rear surface.

Further, the Stirling refrigerator includes a cylinder, a displacer and a piston arranged in this cylinder in order from the head side, a motor provided at the rear of the cylinder, and the displacer and the piston provided by an output of the motor. A reciprocating mechanism for reciprocating the cylinder with a predetermined phase difference, a low-temperature heat exchanger having one end communicating with a space between the head of the cylinder and the displacer, and one end including the displacer and the piston. A high-temperature-side heat exchanger communicating with a space therebetween, a regenerator connected between the other end of the high-temperature heat exchanger and the other end of the low-temperature heat exchanger, the displacer and the cylinder. Actuation filled in the space between the head, the cold side heat exchanger, the regenerator, the hot side heat exchanger and the space between the displacer and the piston What is configured in the body are preferred.

(Operation) When the Stirling refrigerating machine is started to drive, an inverse Stirling cycle that repeats the steps of isothermal compression, isovolume cooling, isothermal expansion, and isovolume expansion is configured. Then, the inside of the refrigerator is cooled by the cold heat of the low-temperature side heat exchanger generated in the reverse Stirling cycle.

Here, the reverse Stirling cycle does not use a fluorine-based refrigerant that is subject to Freon regulation, but is made up of a working fluid such as air or nitrogen gas or helium gas.
No need to worry about environmental pollution.

In addition, the reverse Stirling cycle can obtain substantially the same coefficient of performance as the conventional vapor compression refrigeration cycle.

In addition, the Stirling refrigerator has a simple one-cylinder structure in which a displacer, a piston, and a reciprocating mechanism are provided in a cylinder to which a motor is attached, and a low-temperature heat exchanger, a regenerator, and a high-temperature heat exchanger are provided outside the cylinder. In addition, the pressure of the working fluid is considerably smaller than the maximum pressure and the filling pressure of the conventional vapor compression refrigeration cycle, and the pressure resistance structure is simple, so that it is small and lightweight.

In addition, unlike a conventional evaporative compression type refrigeration cycle, a reverse Stirling cycle composed of a Stirling refrigerator has a low gas flow noise because it is always a gas without a phase change during a cycle process. Both noise and vibration are small.

That is, it is possible to realize a cooler satisfying various required conditions without using a CFC-based refrigerant.

Further, in the present invention, the surface portion of the refrigerator main body is formed of a metal material, and a Stirling refrigerator is provided so that the high-temperature side heat exchanger is connected to the metal material. The formed metal material can be effectively used as a heat radiating plate, and the configuration of the heat radiating system can be simplified.

(Embodiment) Hereinafter, the present invention will be described with reference to an embodiment shown in FIGS. 1 to 6.

FIG. 1 shows a refrigerator-freezer for home use (corresponding to a refrigerator) to which the present invention is applied, and 1 denotes a main body of the refrigerator-freezer. A freezing room 2 is provided in an upper part in the main body 1.
A refrigeration compartment 3 is provided from the center to the lower portion in the main body 1.

A Stirling refrigerator 5 is installed as a cooling device in a cool air supply passage 4 formed at the back of the freezing compartment 2. The structure of this Stirling refrigerator 5 is shown in FIG.

To describe the Stirling refrigerator 5, reference numeral 6 denotes a cylinder, and reference numeral 7 denotes a motor connected to an open end of the cylinder 6. The motor 7 has a structure in which a casing 8 is connected to an open end of a cylinder 6, and a stator 9 and a rotor 10 are provided in the casing 8 coaxially with the cylinder 6. The output shaft 10 connected to the rotor 10
The tip of a extends into the cylinder 6.

A displacer is placed in the cylinder 6 from the head side.
11 and a low temperature piston 12 are arranged in series in this order. These displacer 11 and low-temperature piston 12
Is a cylinder 6 engraved on the inner peripheral surface of the cylinder 6.
The guide groove 13 is restricted along the axis of the shaft so that it can reciprocate without rotating. The displacer 11 and the low-temperature piston 12 are connected to the distal end of the output shaft 10a via a reciprocating mechanism 14 having, for example, a cylindrical cam structure.

Here, the reciprocating mechanism 14 will be described. A cylindrical member 15 is coaxially and integrally connected to the tip of the output shaft 10a. A cam groove 16 is engraved on the outer peripheral surface of the cylindrical body 15 along a circumferential direction so as to draw a sine curve having two peaks and valleys. For example, cam rollers 17 are provided at two points in the cam groove 16 which are out of phase by “90 °”. Of the cam rollers 17, 17, for example, the cam roller 17 on the advancing side is connected to the displacer 11 via an axial arm 19 which slidably penetrates the cam lever 18 and the low temperature piston 12. The other cam roller 17 is connected to the low-temperature piston 12 via a cam lever 20. This allows the displacer 11 and the low-temperature piston 12 to reciprocate in synchronization with a predetermined phase difference with the rotation of the output shaft 10a.

On the other hand, a regenerator 21 is provided on the body part on the head side of the cylinder 6. A plurality of small-diameter heat exchange pipes 21a formed in a substantially J-shape are connected between the regenerator 21 and the head portion of the cylinder 6.
Constitutes a low-temperature-side heat exchanger 22 at the head. Further, between the space existing between the displacer 11 and the low-temperature piston 12 and the regenerator 21, a plurality of small-diameter heat exchange pipes 23a formed in a substantially U-shape are connected and connected. 6
A high-temperature side heat exchanger 23 is formed at the rear side of the heat exchanger. And
Cylinder space between the head of the cylinder 6 and the displacer 11, in the low-pressure heat exchanger 22, in the regenerator 21, in the high-temperature heat exchanger 23, and in the cylinder space between the displacer 11 and the low-temperature piston 12. The working space composed of is filled with a working fluid such as air, nitrogen gas, helium gas, etc., utilizing the reciprocating motion between the displacer 11 and the low-temperature piston 12,
A reverse Stirling cycle can be configured.
Of course, the working fluid is not Freon-based.

Incidentally, reference numeral 24 denotes refrigerating machine oil stored in the casing 8 of the motor 7.

The Stirling refrigerator 5 is installed so as to penetrate the back wall of the freezer 2, and the low-temperature side heat exchanger 22, which is the tip side, protrudes into the cool air supply passage 4. Thereby, the cold obtained by the reverse Stirling cycle can be supplied into the storage. More specifically, at the outlet side of the cool air supply passage 4, an in-compartment circulating fan 27 is provided, which is formed by directly connecting a propeller fan to a fan motor 26 embedded in the back wall of the freezing room 2 to cool the free air. It can be circulated inside. Reference numeral 25 denotes heat exchange fins provided in the cool air supply passage 4 in connection with the low-temperature side heat exchanger 22.

A passage 28 communicating with the cool air supply passage 4 is provided in an upper stage on the back side of the refrigerator compartment 3, and a damper device for controlling opening and closing of the passage 28.
It is provided with 29. Further, a passage 30 communicating with the cold air supply passage 4 is provided also on the upper wall of the refrigerator compartment 3 so that cold air can be circulated in the refrigerator compartment 3.

On the other hand, a V-shaped heat radiation path 31 having a lower side as an inlet and an upper side as an outlet is provided on the back wall of the freezing room 2 so as to expose the high-temperature side heat exchanger 23 of the Stirling refrigerator 5.
Is provided. The inlet side of the heat radiation path 31 is open to the rear of the main body 1. The outlet side of the heat radiating path 31 is opened above the main body 1 through a vertical passage 32 provided on the back wall of the freezing compartment 2. In the passage 32, a heat radiating fan 33, which is formed by directly connecting the cross flow fan to the fan motor 26, is arranged to release heat generated from the high temperature side heat exchanger 23 by air cooling. In the present embodiment, the outer surface of the main body 1 is made of a metal plate or the like having good heat conductivity, and the high-temperature side heat exchanger 23 is brought into contact with or connected to this outer surface, so that the heat radiation effect of the high-temperature side heat exchanger 23 is reduced. I also try to increase.

Further, a defrosting device 34 is provided in the passage 30. The structure of the defrosting device 34 is shown in FIG.

Explaining the defrosting device 34, reference numeral 35 denotes a plurality of circular through holes provided in a wall portion 36 separating the cold air supply passage 4 and the heat radiation passage 31 so as to communicate inside and outside. The through hole 35 is the cylinder 6
Are arranged at predetermined intervals on the same circle centered on the axis of the cylinder 6 around the penetrating portion 35a that penetrates. An annular plate 37 for ventilation control is rotatably supported on the body of the cylinder 6 so as to overlap with the group of through holes. The annular plate 37 has a through-hole 38 having the same shape and the same arrangement as the through-hole 35 on the plate surface, and has a gear portion 39 on the outer peripheral surface.

On the other hand, a motor 40 is embedded in the wall portion 36 corresponding to the position of the gear portion 39 of the annular plate 37. The output shaft of the motor 40 is provided with a gear 41 that meshes with the gear portion 39. Further, a control unit (both not shown) is connected to the motor 40 via a drive circuit. Under the control of the control unit, the position of the through hole 35 on the main body 1 side and the position of the through hole 38 of the annular plate 37 are made different at all times to shut off the inside and outside, and an operating unit (or a sensor for detecting frost formation) not shown , The annular plate 37 is rotated so that the two through holes 35 and 38 coincide with each other. That is, if they match, the heat of the high-temperature side heat exchanger 23 is guided to the low-temperature side heat exchanger 22, and the frost that has reached the low-temperature side heat exchanger 22 and the heat exchange fins 25 is melted.

In the figure, reference numeral 45 denotes a door for opening and closing the freezer compartment 2 and 46 denotes a refrigerator compartment 3.
The door that opens and closes.

Next, the operation of the refrigerator-freezer configured as described above will be described.

Insert a power plug (not shown) into the outlet and turn on the refrigerator. Thus, the motor 7 is excited, and the rotor 10 rotates together with the output shaft 10a.
Then, the cylindrical body 15 rotates. Then, this rotation is converted into reciprocating motion by the cam rollers 17, 17 at a predetermined position where the cam groove 16 moves.

This allows the displacer 11 and low-temperature piston
12 reciprocates in the cylinder 6 with a predetermined phase difference, and constitutes a reverse Stirling cycle as shown in FIGS.

That is, in the process of “A → B” in which the low-temperature piston 12 rises, the working fluid is compressed, and the heat generated by the compression is transferred to the high-temperature side heat exchanger 23 and the cooling chamber main body to which the heat exchanger 23 is connected. The heat is radiated to the atmosphere from the surface of the surface layer material of No. 1, that is, the metal material forming the surface layer (isothermal compression process).

Then, the next displacer 11 descends "B →
C, passes through the regenerator 21 and passes through the displacer 11
The working fluid at the bottom of moves upward. At this time, the working fluid is cooled by the cold stored in the regenerator 21 (equal volume cooling process).

Subsequently, the working fluid expands in the “C → D” stroke in which the low temperature piston 12 descends. That is, a refrigeration action occurs. At this time, the working fluid is kept isothermal by external heat (isothermal expansion process).

When the isothermal expansion process is completed, the cooled working fluid is guided to the low-temperature side heat exchanger 22 and the regenerator 21 in the “D → A” process in which the displacer 11 rises (equal volume heating). process).

As a result, the low-temperature side heat exchanger 22 absorbs heat in the isothermal expansion process, and the high-temperature side heat exchanger 23 releases heat in the isothermal compression process. That is, the cold heat of the low-temperature side heat exchanger 22 generated in the operation of the reverse Stirling cycle is supplied into the refrigerator. And this cold heat is circulated in the refrigerator 27
To the freezer compartment 2
Circulates in the refrigerator compartment 3.

The heat radiated from the high-temperature side heat exchanger 23 is discharged to the upper part of the main body 1 through the passage 32 by the blowing of the radiating fan 33. However, part of the heat is radiated from the outer surface of the main body 1 to the atmosphere.

Here, the bore of the displacer 11 and the low-temperature piston 12 is about 40 mm, the stroke is about 16 mm, and the working fluid is nitrogen gas with a filling pressure of 5 kgf / cm ^2. When the heat exchange wall temperature was set to “−30 ° C.” (temperature used for general refrigerators) and the high-temperature side exchange wall temperature was set to “+ 30 ° C.”, and the motor 7 was driven, the result is shown in FIG. As shown, "1500rpm" is about "60W", "3000rpm" is "100W"
A degree of endothermic capacity was obtained. Also, from the viewpoint of performance efficiency,
A coefficient of performance of "approximately 0.4 to 0.8", which is a value close to the coefficient of performance of the conventional compressor type refrigeration cycle, was obtained.

In addition, as a result of an experiment using air, helium gas, or the like as a working fluid (the low-temperature side heat exchange wall temperature was set to “−30 ° C., and the high-temperature side exchange wall temperature was set to“ + 30 ° C.)), the charging pressure was “0 1010 kgf / cm ² ”, and the same results as described above were obtained.

In other words, the Stirling refrigerator 5 uses air or nitrogen gas, helium gas, or the like, under the operating conditions in which the filling pressure at that time is set to “0 to 10 kg f / cm ² ” and the rotation speed is set to “3000 rpm or less”. It was found that by setting the heat absorption capacity to about "100W", it was possible to demonstrate the optimum capacity for use in freezers and refrigerators.

Thus, it is possible to realize a refrigerator-freezer that performs a cooling operation suitable for a freezer or a refrigerator without using a refrigerant based on the CFCs.

In addition, the Stirling refrigerator 5 is much smaller and lighter than a conventional evaporative compression type refrigeration cycle.

Specifically, the refrigeration cycle system used in conventional refrigerators requires large parts such as condensers, and even heavy parts, so it weighs about 10 kgf. The Stirling refrigerator 5 has a one-cylinder structure that does not require such parts, and has about half or less “3.5 kg
f "weight. Moreover, in the refrigeration cycle system, the maximum pressure of the cycle is "12 kg f / cm ² ",
Since the Stirling refrigerator 5 requires only half the pressure of “6 kg f / cm ² ”, the pressure resistance structure is simplified, and the size and weight can be reduced accordingly.

In addition, since the Stirling refrigerator 5 is always a gas without a phase change during a cycle process, the Stirling refrigerator 5 has low airflow noise, low noise and low vibration.

Further, since the surface portion of the cooling main body 1 is formed of a metal material and the Stirling refrigerator 5 is provided so that the high-temperature side heat exchanger 23 is connected to the metal material, the surface portion of the cooling main body 1 is formed. The formed metal material can be used effectively as a heat sink,
The configuration of the heat radiation system can be simplified.

In addition, if frost forms on the low-temperature side heat exchanger 22, the operation unit may be operated. That is, the annular plate 37 is
It rotates by a predetermined angle so as to communicate with 38 and the through hole 35 on the main body 1 side. As a result, the heat released from the warm side heat exchanger 23 is guided to the low temperature side heat exchanger 22 to melt the frost.

FIG. 7 and FIG. 8 show another embodiment of the present invention. In the present embodiment, the low-temperature side heat exchanger 22 is not constituted by a pipe, but is constituted by joining two plates. That is, plate members 51 and 5 having good heat conductivity such as a pair of aluminum plates formed with a recess 50 for a passage in the plate surface by press molding.
1 is formed by adhesive bonding or brazing so that the two concave portions 50 face each other. Such a structure increases the effective heat transfer area several to several tens of times while keeping the cross-sectional area and dead volume of the passage formed by the recesses 50 and 50 the same as the pipe-type heat exchanger of the previous embodiment. There are advantages that can be. Of course, this structure may be applied to the high-temperature side heat exchanger.

In the above embodiment, defrosting is performed using an annular plate having a plurality of through-holes formed on a plate surface. However, the present invention is not limited to this. May be transferred to the frosted low-temperature side heat exchanger and melted. Further, in the embodiment, the cylindrical cam structure is used for the reciprocating mechanism. However, another structure may be used to reciprocate the displacer and the low-temperature piston with a predetermined phase difference.

[Effects of the Invention] As described above, according to the present invention, a cooling operation can be performed without using a CFC-based refrigerant.

In addition, the Stirling refrigerator has a simple one-cylinder structure with a simple pressure-resistant structure, so that it is excellent in miniaturization and weight reduction.

In addition, the Stirling refrigerator has low noise and low vibration due to low airflow noise. It also has a good coefficient of performance and is excellent in high cooling efficiency.

Also, in particular, the surface portion of the refrigerator main body is formed of a metal material, and a Stirling refrigerator is provided so that the high-temperature side heat exchanger is connected to this metal material. Metal material can be used effectively as a heat sink, and the configuration of the heat dissipation system can be simplified.

[Brief description of the drawings]

1 to 6 show an embodiment of the present invention.
FIG. 2 is a side sectional view showing a refrigerator to which the present invention is applied, FIG. 2 is a side sectional view showing a Stirling refrigerator, FIG. 3 is an exploded perspective view showing a defroster, and FIG. And FIG. 5 shows the T-S
Diagram, FIG. 6 is a diagram showing the performance of the Stirling refrigerator,
FIG. 7 is a sectional side view showing the structure of a high-temperature side heat exchanger as a main part of another embodiment of the present invention, and FIG. 8 is a sectional view taken along the line XX. DESCRIPTION OF SYMBOLS 1 ... Main body, 2 ... Freezer room, 3 ... Refrigerator room, 5 ... Sterling refrigerator, 6 ... Cylinder, 7 ... Motor, 11 ...
... displacer, 12 ... low-temperature piston, 14 ... reciprocating mechanism, 16 ... cam groove, 17 ... cam roller, 21 ... regenerator, 22 ... low-temperature heat exchanger, 23 ... high-temperature heat exchanger .

Claims (3)

(57) [Claims] A cooling chamber body having a housing portion for housing an object to be cooled therein and a cool air passage serving as a passage for circulating cool air through the housing portion, and a surface layer portion formed of a metal material; A stirling refrigerator provided with a high-temperature side heat exchanger connected to the metal material forming the surface portion of the cooling box body and a low-temperature side heat exchanger positioned in the cool air passage. A cooling cabinet characterized by the following. 2. The cooling cabinet main body has an opening / closing door on a front portion thereof, and the housing portion and the cold air passage are formed in the depth direction from the opening / closing door in order. The cooling cabinet according to claim 1, wherein the cooling cabinet is provided between the cooling cabinet main body and a rear surface thereof. 3. The Stirling refrigerator includes a cylinder,
A displacer and a piston arranged in this cylinder in order from the head side, a motor provided at the rear of the cylinder, and a reciprocating motion for reciprocating the displacer and the piston with a predetermined phase difference by an output of the motor. A mechanism, a low-temperature heat exchanger having one end communicating with a space between the cylinder head and the displacer, and a high-temperature heat exchanger having one end communicating with a space between the displacer and the piston. A regenerator connected between the other end of the high-temperature heat exchanger and the other end of the low-temperature heat exchanger; a space between the displacer and the cylinder head; A heat exchanger, the regenerator, the high-temperature side heat exchanger, and a working fluid filled in a space between the displacer and the piston, and operated in a reverse Stirling cycle. Refrigerator according to claim 1 or 2, characterized in that it is.