JP3607837B2 - refrigerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small refrigerator that can be installed in a narrow installation space such as a side of a car seat and can be removed for portable use.
[0002]
[Prior art]
As a cooling means inside the wall, such as a refrigerator or freezer, a so-called Rankine cycle compressor refrigerator (hereinafter referred to as “cooling”) that cools the surroundings by causing an endothermic action in the process of compressing and expanding the refrigerant and exchanging the heat. "Rankine cycle") is known. In the Rankine cycle, a compressor, a condenser, and the like for compressing and expanding are provided outside a freezer or the like, and each of these cycles is performed by rotation of a motor.
[0003]
Rankine cycle refrigerators are difficult to install as on-vehicle refrigerators and have problems such as waste heat treatment. When there is a strong demand for installation in the car, it can be used only when installing in a troublesome place away from the seat such as a trunk room.
[0004]
Recently, Peltier elements have been applied to refrigeration means such as in-vehicle refrigerators and vending machines. Refrigerators that use Peltier elements do not need to be equipped with a compressor or condenser, and therefore do not use harmful substances such as fluorine gas, and are being miniaturized. Therefore, it is being adopted for a considerable number of passenger cars.
[0005]
Furthermore, the recently proposed chiller using the Stirling cooling system (hereinafter referred to as “Stirling chiller”) is a self-cooling type refrigeration system that is portable and does not have an external compressor, condenser, etc. Since it has low power consumption and high energy efficiency, it has been attracting attention as being mounted inside a car or can be used for refrigeration of fresh food outdoors for portable use.
[0006]
The cooling efficiency by the Stirling refrigerator is, for example, 5 W or less for a 30 liter portable refrigerator, and 8 W or less for a 200 liter single temperature unit. This can be used with small solar systems and battery power. Furthermore, since it uses only a small amount of helium (He) without using fluorine gas that is low in noise and harmful to the atmosphere as a refrigerant, it is friendly to the global environment. Here, the cooling effect of the Stirling refrigerator 1 is such that the inside of the cabinet is cooled through an aluminum material made of a metal having high thermal conductivity and low specific gravity.
[0007]
FIG. 3 shows the cooling principle of a refrigerator employing the above Stirling refrigerator. In the Stirling refrigerator 1, elements for circulating a refrigerant such as a piston, a displacer, and a linear motor are housed in a portion indicated by a small diameter, and a base portion thereof is a heat radiating portion 4 a. Here, fins 4b made of a copper plate are attached. The tip part (upper end) of the part shown by this small diameter is the heat absorption part 4c.
[0008]
The heat absorption part 4c of the Stirling refrigerator 1 is fixed to the center part of the cooling member 22 formed of aluminum casting so as to correspond to the bottom plate part of the cabinet 21. The heat absorbing portion 4c and the cooling member 22 are firmly coupled so as not to reduce the thermal conductivity. Further, the cooling member 22 is brought into contact with an aluminum plate 23 which also serves as a lining of the cabinet at the bottom plate portion of the cabinet to improve heat conduction efficiency. The cabinet exterior 24 is made of a lightweight and highly heat-insulating member such as polystyrene foam, and is further equipped with a band or the like necessary for mounting and carrying (not shown). The Stirling refrigerator 1 is provided with a fan at the lower end of the portion shown in a large diameter in order to enhance the cooling effect, but since the Stirling refrigerator itself is small, the ratio of the fan to the cabinet is Small and light weight overall. However, since the Stirling refrigerator is installed vertically at the bottom of the cabinet, there is a weak point that the overall height becomes high.
[0009]
On the other hand, as shown in FIG. 4, the Stirling refrigerator 1 can be attached horizontally to the bottom of the cabinet 31. In this case, a mounting portion 32a is provided by projecting the cooling member 32 downward from the bottom, and the heat absorbing portion 4c of the Stirling refrigerator 1 is fixed thereto. The cabinet lining 33 and exterior 34 are in accordance with FIG.
[0010]
[Problems to be solved by the invention]
Regarding the refrigerator using the Rankine cycle system described above, in consideration of the influence of the refrigerant on the environment, in addition to the above disadvantages in manufacturing, to further promote the adoption as a portable or in-vehicle refrigerator There is a limit.
[0011]
On the other hand, it can be said that a refrigerator using a Peltier element has advantages of miniaturization and clearing environmental problems. However, Peltier elements have low refrigeration efficiency in the current state of the art, and require a large amount of power even in refrigerators with a small internal volume, which increases the fuel consumption rate of automobiles and causes the battery to run out when the engine is stopped. There is. Further, in a so-called light vehicle having an engine cylinder volume of less than 1000 m1, there is a problem that such a refrigerator cannot be used because of its small power generation capacity.
[0012]
In addition, there are cases where cold beer or juice is required for outdoor barbecue etc. due to the spread of outdoor leisure. In such cases, it is required to carry a refrigerator and use it outdoors. Is done. However, a refrigerator using a Peltier element that consumes a large amount of power has a problem that it is difficult to supply such power because it is difficult to supply power.
[0013]
Therefore, the use of a Stirling refrigerator with low power consumption was studied, and in order to use this, a flow of air was created in the heat-absorbing section with a fan to send cold air into the cabinet, or direct conduction heat exchange such as aluminum Means are used.
[0014]
The above-described Stirling refrigerator is suitable for a refrigeration system for a portable or vehicle-mounted refrigerator because of its small size and high performance. However, when this is employed, the following problems arise. In other words, the Stirling refrigerator is configured to cool with a heat absorbing portion provided at one end portion and to dissipate heat with a heat radiating portion provided near the central portion of the apparatus main body. For this reason, it is required that the heat absorption part is located inside the cabinet and the heat radiation part is located outside the cabinet to increase the heat radiation effect using a fan or the like. However, it is difficult to attach the Stirling refrigerator to the cabinet so that the relationship between the two is actually satisfied.
[0015]
In addition, even in the case of adopting the configuration as shown in FIGS. 3 and 4, since the heat exchange action is insufficient, there is a disadvantage that sufficient cooling efficiency cannot be obtained. In addition, due to the structure of the Stirling refrigerator, the installation position must be the lower part of the cabinet, so that the overall height is increased and the heat dissipation is insufficient.
[0016]
SUMMARY OF THE INVENTION An object of the present invention is to provide a low-cost refrigerator that can be installed in a vehicle, portable, or in a narrow space, with a simple structure and high energy efficiency, so that a Stirling refrigerator can be used.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, the refrigerator of the present invention employs a thermal siphon composed of a heat transfer pipe through which fluid can circulate in order to extract cool air from the heat absorption part of the Stirling refrigerator and cool the inside of the cabinet. It is.
[0018]
A thermal siphon consists of a copper or aluminum tube connected substantially endlessly and filled with a refrigerant gas such as carbon dioxide (CO ₂ ) or butane (C ₄ H ₁₀ ). The pipe is tightly wound a plurality of times to form a condenser part, and the fluid in the pipe is changed from gas to liquid.
[0019]
One end of the condenser part moves to an evaporator part provided in the cabinet through a small-diameter liquid line, and the pipe is warmed by the warm temperature in the cabinet, and changes from liquid to gas. At this time, the inside of the cabinet is cooled by the endothermic effect caused by this phase change. Here, the fluid changed to gas passes through the evaporator section, and then returns to the condenser section through the gas line, and the cooling operation in the cabinet is continued by sequentially repeating the cycle of phase change to liquid again.
[0020]
When the Stirling refrigerator is mounted on the cabinet, it is mounted so that it is vertical and the heat absorption part is on top, so that the fluid liquefied in the condenser part easily flows out from a high place. Thereby, circulation of the liquid in the thermal siphon is promoted to promote the heat exchange action.
[0021]
In addition, the liquid line connects the lower end of the condenser section provided at a high place and the lower end of the evaporator section provided at a low place with a drop, and the fluid liquefied in the condenser section is The movement is facilitated by the action. At the same time, the flow area is reduced to make it difficult to reverse the gas evaporated in the evaporator section.
[0022]
The gas line connects the upper end of the lower evaporator section and the upper end of the upper condenser section so as to be an upward path for the fluid, and moves the vapor that is heated and vaporized in the evaporator section. To make it easier. In this way, fluid circulation in the thermal siphon is smoothly performed by both the above lines.
[0023]
According to this means, since it is not necessary to place the heat absorption part of the Stirling refrigerator in the cabinet, the Stirling refrigerator can be installed at any position outside the cabinet, and also for cooling the heat radiation part of the Stirling refrigerator. There will be no hindrance.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
First, the principle of the refrigeration system in the present invention will be described.
[0025]
FIG. 1 conceptually shows a refrigeration system according to the present invention. By providing a thermal siphon 2 in a Stirling refrigerator 1, the inside of a refrigerator (cabinet) 3 can be cooled.
[0026]
As described above, the Stirling refrigerator 1 is a small and light refrigeration system having high energy efficiency, and has a track record of power consumption of 5 W or less in a portable refrigerator that cools a volume of 30 liters.
[0027]
The Stirling refrigerator 1 is characterized by high energy efficiency, low noise, and light weight, and exhibits an extremely high performance compared to a conventional Rankine cycle type refrigeration system. The reason for realizing such high performance is that a refrigeration cycle for changing the refrigerant gas is performed in the cylinder, a small amount of helium (He) is used as the refrigerant gas, and a driving source for the reciprocating movement of the piston. As a result, a linear motor is used.
[0028]
Here, an outline of the configuration of the Stirling refrigerator 1 will be described. As shown in FIG. 1, the center part of the body 4 which consists of a step-shaped cylindrical body is the thermal radiation part 4a, and the copper fins 4b are provided in the circumference | surroundings. The upper end portion of the portion having a small diameter of the body is a heat absorbing portion 4c, and this heat absorbing portion can be cooled to about minus 20 ° C. in a short time. A cooling fan 4d is provided at the lower end of the body 4 so that a piston, a linear motor, etc., not shown, can be cooled.
[0029]
As described above, the Stirling refrigerator 1 does not require a compressor, a motor for driving the compressor, a condenser, and a heat exchanging unit, and therefore, a Rankine cycle is required to obtain the same cooling capacity. It will be in time with a fraction of the space and a small amount of power consumption.
[0030]
The thermal siphon 2 is formed by connecting a pipe made of copper or aluminum substantially endlessly and filling the pipe with carbon dioxide (CO ₂ ) or butane (C ₄ H ₁₀ ) as a refrigerant gas. The thermal siphon 2 is a liquid from the condenser part 2a that is wound tightly around the heat absorption part 4c of the Stirling refrigerator 1 and the evaporator part 2b that is meandered in the cabinet 3 and from the condenser part to the evaporator part. The liquid line 2c is a small-diameter pipe that transports the gas, and the gas line 2d is configured to return the gas from the evaporator section to the condenser section. As the refrigerant gas, in addition to the above, acetone, ethanol, or the like can be used.
[0031]
The condenser part 2a is cooled by the heat absorption part 4c, the refrigerant gas condenses and changes phase from gas to liquid, and the liquid whose volume is reduced by the phase change passes through the liquid line 2c of the thermal siphon and the evaporator part 2b. Move to.
[0032]
In the evaporator section 2b, the meandering portion of the pipe is heated from the outside by the temperature inside the cabinet, and the refrigerant changes phase from liquid to gas. Here, since a large amount of heat of vaporization is required for the phase change, an endothermic action occurs and the inside of the cabinet is cooled. The fluid (refrigerant) vaporized in the evaporator part 2b returns to the condenser part 2a through the gas line 2d. In the condenser part 2a, the refrigerant is cooled again, the volume is reduced by condensation, and a negative pressure is obtained. The fluid in the gas line 2d is sucked to give direction to the flow in the thermal siphon.
[0033]
Further, the liquid line 2c has a small diameter and a small flow path area, but this serves to make it difficult to back flow the gas vaporized in the evaporator section. Even if the diameter is small, in the condenser part 2a, the fluid is liquefied by cooling and the volume is reduced. The flow area of the liquid line 2c may be configured such that the entire thermal siphon is configured by a pipe having the same inner diameter, and the flow area is reduced by partially passing through a core in the pipe.
[0034]
Thus, the thermal siphon 2 is capable of lowering the temperature in the cabinet 3 by circulating the fluid by changing the temperature, pressure and volume of the fluid in the pipe and repeating the phase change cycle of condensation and evaporation. .
[0035]
FIG. 2 shows the appearance of the refrigerator according to the present invention. As shown in FIG. 2, the Stirling refrigerator 1 is attached to one side of the cabinet 3 so that the heat absorption part 4c is on the upper side by using attachment means such as a band. The storage unit 3a is provided with a thermometer (not shown) for measuring a temperature change by a change in current value, and temperature measurement data can be output to a control panel (not shown) provided on the outside of the cabinet. is there. This control panel is provided with a power switch, a temperature adjustment knob, and a cooling temperature display window, and can display the temperature in the storage portion 3a.
[0036]
The liquid line 2c and the gas line 2d of the thermal siphon 2 wound around the heat absorbing part 4c penetrate one side of the cabinet 3 and are disposed in the cabinet storage part 3a (FIG. 1). Reference). The gas line 2c introduced into the storage unit 3a is suspended near the bottom of the storage unit and connected to the evaporator unit 2b. The evaporator part 2b is connected to the lower end part of the gas line 2d after 2-3 rounds along the inner peripheral part of the cabinet. The gas line 2d is set up vertically, and as described above, the upper end of the gas line 2d passes through one side of the cabinet 3 and is connected to the condenser unit 2a.
[0037]
An inner lining 3b made of an aluminum thin plate is provided on the inner peripheral portion of the storage portion 3a, so that the thermal siphon can be prevented from being damaged and a hand or the like can be prevented from touching the juice when it is taken in or out. The storage portion 3a can be opened and closed by a lid 3c.
[0038]
When attaching a conventional refrigerator to a car for outdoor use, it was limited to the trunk and the rear baggage. It can be installed in a narrow space such as between the seats or between the driver seat and the passenger seat. Moreover, since the refrigerator in the present invention can achieve a sufficient cooling effect with low energy consumption, for example, 3 to 4 W in the case of normal on-vehicle use, the burden on the car battery can be remarkably reduced. Furthermore, the conventional refrigerator cannot be used for a small car due to its large power consumption, but the refrigerator of the present invention can be used sufficiently even for a light vehicle having a volume of less than 1000 m1.
[0039]
As described above, the refrigerator of the present invention is small and light and has low energy consumption, so that it has excellent properties for in-vehicle use, and is convenient for carrying in a small space. In addition, it can be sufficiently used for mounting on marine sports vessels and aircraft other than in-vehicle use. In addition, since it has such low energy consumption performance, it has good connectivity with solar cell-based solar systems and can be operated for a long time just by providing a small solar panel and voltage control device. Since it is easy to carry the power generation system at the same time, it can be expected to expand its use as an outdoor product.
[0040]
【The invention's effect】
According to the present invention, since the Stirling refrigerator having excellent performance as described above and the refrigerator cabinet are coupled by the thermal siphon, it is possible to provide a refrigerator with a simple structure and high cooling efficiency. Become.
[0041]
Since the present invention employs a small and light Stirling refrigerator that is excellent in energy efficiency as a refrigerator refrigeration system, it can be mounted on any vehicle body as a vehicle-mounted seat. It becomes very convenient because it can be installed in a narrow space.
[0042]
In addition, since it has low power consumption, it is also suitable for use with solar systems, so it is highly portable, and it is useful for outdoor parties such as taking it out of the car. It is.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the configuration of an example of an embodiment of the present invention.
FIG. 2 is a perspective view showing the overall appearance of the same.
FIG. 3 is a cross-sectional view showing a main part of a conventional example employing a Stirling refrigerator.
FIG. 4 is a cross-sectional view showing a main part of another conventional example employing a Stirling refrigerator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stirling refrigerator 2 Thermal siphon 2a Condenser part 2b Evaporator part 2c Liquid line 2d Gas line 3 Cabinet 4c Endothermic part

Claims (3)

A so-called Stirling refrigerator is fixed to one side of the freezing cabinet,
The endothermic part provided at one end of the Stirling refrigerator is provided with a condenser part in which a specific range of a thermal siphon consisting essentially of an endless pipe is wound a plurality of times,
Inside the refrigeration cabinet is provided with an evaporator portion that is arranged so that other specific ranges of the thermal siphon are rounded along the inner peripheral portion of the cabinet,
The condenser part and the evaporator part are connected via a liquid line that becomes a passage through which the fluid liquefied in the condenser part moves to the evaporator part,
The liquid line is provided so as to have a drop by connecting the lower end portion of the evaporator section provided at a low place from the lower end section of the condenser section provided at a high place ,
The evaporator part and the condenser part are connected via a gas line that serves as a passage for the fluid vaporized in the evaporator part to return to the condenser part,
The gas line is provided so that the fluid can rise from the upper end of the evaporator section at a low position to the upper end section of the condenser section at a high position ,
The refrigerator characterized in that the inside of the cabinet can be cooled by repeating a phase change cycle of the fluid circulating in the thermal siphon . 2. The refrigerator according to claim 1, wherein the Stirling refrigerator is mounted such that the Stirling refrigerator is perpendicular to one side portion of the cabinet and the heat absorbing portion is located above. 3. The refrigerator according to claim 1, wherein a flow passage area of the liquid line of the thermal siphon is smaller than a flow passage area of the evaporator section.

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