JPH04126973A - Electronic refrigerator - Google Patents

Abstract

PURPOSE:To improve a cooling efficiency in a refrigerator by a method method wherein some thermo-siphons having heat exchanging medium enclosed therein are disposed at a thermal absorption side and a thermal radiation side of a thermo-electrical element, an inside part of the refrigerator is cooled by the thermo-siphons at the heat absorption side and the heat is radiated by the thermo-siphon at the heat radiation side, CONSTITUTION:A thermo-electrical element 8 is buried at a thermal insulating wall 5 at a rear surface of a main body 1 of a refrigerator. Both ends of pipes 9b and 10b are connected to both upper and lower ends of heat exchanging parts 9a and 10a of the thermo-electrical element 8. Heat exchanging medium in the heat exchanging parts 9c and 10a at a high temperature side constituting the thermo-siphons 9 and 10 may absorb heat and be gasified to reduce its density. The heat exchanging medium ascends in the thermo-siphons 9 and 10, reaches the heat exchanging parts 9a and 10c and radiates heat and again the medium is liquified, the medium descends in the thermo-siphons 9 and 10 and reaches the heat exchanging parts 9c and 10a after absorbing heat at the heat exchanging part 9c in the refrigerator. The absorbed heat is transported to a heat absorbing surface 8a of the thermo-electrical element 8. The heat absorbed in the thermo-electrical element 8 is transmitted from the heat radiating surface 8b to the heat exchanging medium in the thermo-siphons 10 outside the refrigerator and then the heat is radiated from the heat exchanging part 10c out of the refrigerator.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to an electronic refrigerator using a thermoelectric element as a cooling source.

(Prior Art) In a conventional electronic refrigerator, as shown in, for example, Japanese Utility Model Application Publication No. 1-109771, a thermoelectric element is embedded in the back insulating wall of the refrigerator body, and the heat absorption surface of the thermoelectric element is used as a heat absorbing surface of the refrigerator. On the inside, the heat radiating surface faces the outside of the refrigerator, and aluminum heat exchangers are brought into contact with the heat absorbing surface and the heat radiating surface of the thermoelectric element, respectively. In this case, when a current is applied to the thermal lightning element, the Peltier effect causes a phenomenon in which heat is absorbed from the heat-absorbing surface and released from the heat-radiating surface, thereby transferring the heat inside the refrigerator to the aluminum heat exchanger inside the refrigerator. The inside of the refrigerator is cooled by absorption through the body from the heat absorption surface of the thermoelectric element, while the heat absorbed in the thermoelectric element is radiated outside the refrigerator from the heat radiating surface through the aluminum heat exchanger on the outside of the refrigerator.

(Problem to be solved by the invention) By the way, in order to improve the cooling efficiency inside the refrigerator, the air inside the refrigerator - the aluminum heat exchanger inside the refrigerator - the thermoelectric element → the aluminum heat exchanger outside the refrigerator → the heat to the outside air. It is necessary to efficiently transfer heat, but in the conventional configuration, there is a limit to heat transfer through the aluminum heat exchanger, and the cooling efficiency is inevitably kept low. For this reason, electronic refrigerators currently in practical use are limited to small refrigerators with small internal volumes, and it has been difficult to put large electronic refrigerators into practical use.

The present invention was made in consideration of these circumstances, and its purpose is to significantly improve the cooling efficiency inside the refrigerator.
To provide an electronic refrigerator whose internal volume can be expanded.

[Structure of the Invention (Means for Solving the Problem) The electronic refrigerator of the present invention uses a thermoelectric element as a cold heat source, and a heat exchange medium is sealed on the heat absorption side and the heat radiation side of the thermoelectric element, respectively. Thermosiphons are arranged to enable heat exchange, and the thermosiphon on the heat absorption side cools the inside of the refrigerator, while the thermosiphon on the heat radiation side radiates the heat of the thermoelectric element to the outside of the refrigerator.

In this case, the center position of the inside heat exchange part of the thermosiphon on the heat absorption side is set lower than the center position of the heat absorption surface of the thermoelectric element, and the center position of the outside heat exchange part of the thermosiphon on the heat radiation side is set lower than the center position of the heat exchange part of the heat absorption side of the thermoelectric element. It may be set higher than the center position of the surface.

Furthermore, the inner walls of the thermoelectric element-side heat exchange portions of both the heat-absorbing and heat-radiating thermosiphons may be formed into an uneven shape.

Moreover, the inside heat exchange part of the thermosyphon on the heat absorption side may be arranged so as to be attached to the back surface of the inner plate of the heat insulating wall of the refrigerator main body, and the inner plate may be used as the cooling surface.

(Function) When a thermoelectric element is energized, it absorbs heat from the heat absorption surface due to the Peltier effect and releases the heat from the heat radiation surface, causing a phase change in the heat exchange medium in the thermosiphons on both sides, which causes the gravity Use this to create natural circulation. As a result, the thermosyphon on the heat absorption side (inside the refrigerator) absorbs the heat inside the refrigerator in the refrigerator side heat exchange section to cool the refrigerator interior, and the heat absorbed from the refrigerator is transferred to the thermoelectric element by the circulation action of the heat exchange medium transport to the endothermic surface of The heat absorbed in the thermoelectric element is transferred from its heat radiation surface to the heat exchange medium in the thermosiphon on the heat radiation side (outside the refrigerator), and due to the circulation of this heat exchange medium, the heat exchanger on the outside of the thermosiphon is released outside the warehouse. In this way, the circulation of the heat exchange medium can promote the transfer of heat from the inside of the refrigerator to the outside of the refrigerator, making it possible to efficiently cool the interior of the refrigerator.

By the way, the principle of heat transport using a thermosiphon is that the heat exchange medium in the heat exchange section on the high temperature side absorbs heat from the outside and evaporates, so that the heat exchange medium with reduced density rises inside the thermosiphon. The heat exchange medium reaches the heat exchange section on the low temperature side, where it radiates heat and liquefies again, and the heat exchange medium, which has increased in density, descends inside the thermosiphon due to gravity and reaches the heat exchange section on the high temperature side, creating a cycle. It transports heat repeatedly, and is unique in that it uses phase change and gravity to naturally circulate the heat exchange medium.

Therefore, the center position of the inside heat exchange part of the thermosiphon on the heat absorption side is set lower than the center position of the heat absorption surface of the thermoelectric element, and the center position of the outside heat exchange part of the thermosiphon on the heat radiation side is set lower than the center position of the heat exchange part of the heat radiation side of the thermoelectric element. If the height is higher than the center position of the surface, the center position of the heat exchange part on the high temperature side of both thermosiphons (the part where the density of the heat exchange medium decreases due to vaporization) will be the center position of the heat exchange part on the low temperature side (the part where the density of the heat exchange medium becomes liquefied). Since the center position is lower than the center position of the larger part), natural circulation of the heat exchange medium using gravity is promoted, increasing heat transport efficiency.

Furthermore, if the inner walls of the heat exchange parts on the thermoelectric element side of both the thermosiphons on the heat absorption side and the heat radiation side are formed in an uneven shape, the contact area (heat exchange area) between the inner wall of the heat exchange parts on the thermoelectric element side and the heat exchange medium can be increased.
is expanded, increasing the heat transfer efficiency between the two.

In addition, if the heat exchange part inside the refrigerator of the thermosiphon on the heat absorption side is placed along the back side of the inner plate of the heat insulating wall of the refrigerator body, and the inner plate is used as the cooling surface, the thermosiphon is exposed inside the refrigerator. This makes it possible to improve the appearance of the inside of the refrigerator and expand the effective volume of the inside of the refrigerator.

(Example) Hereinafter, a first example of the present invention will be described based on FIGS. 1 and 2.

The refrigerator main body 1 is composed of a heat insulating wall 5 filled with a heat insulating material 4 between an outer box 2 and an inner box 3, and an internal space surrounded by the heat insulating wall 5 is defined as a cooling chamber 6.

The front side of this cooling chamber 6 is opened and closed by a door 7.

On the other hand, a thermoelectric element 8 is embedded in the heat insulating wall 5 on the back side of the refrigerator main body 1, and the heat absorption surface 8a of the thermoelectric element 8 is directed toward the inside of the refrigerator, and the heat radiation surface 8b is directed toward the outside of the refrigerator.

Closed-loop thermosiphons 9 and 10 each have a heat exchange medium sealed on the heat absorption side and the heat radiation side of the thermoelectric element 8.
is located. In each of these thermosiphons 9, 10, a heat exchange part 98.10g on the thermoelectric element 8 side is formed in a box shape larger than the thermoelectric element 8 (see Fig. 2), and the heat exchange part 98.10g on the thermoelectric element 8 side is formed in a box shape larger than the thermoelectric element 8 (see Fig. Closely attached. Pipes 9b, 1. A closed-loop thermosiphon 9.10 is configured by connecting both ends of Ob, and the thermosiphon 9 on the heat absorption side is exposed inside the cooling chamber 6 (inside the warehouse).
A large number of fins 11 are provided in the heat exchange section 9c on the inside of the refrigerator. On the other hand, the thermosiphon 10 on the heat radiation side is projected outside the refrigerator, and a large number of fins 12 are also provided on the heat exchange section 10c outside the refrigerator.

In this case, both thermosiphons 9 and 10 are arranged on the endothermic side (
The center position C1 of the inside heat exchange part 9C of the thermosiphon 9 on the inside of the refrigerator is set lower than the center position Co of the heat absorption surface 8a of the thermoelectric element 8, and the outside heat exchanger of the thermosiphon 10 on the heat radiation side (outside the refrigerator) The center position C2 of the portion 10c is set higher than the center position C8 of the heat radiation surface 8b of the thermoelectric cable 8.

Furthermore, in order to improve the heat transfer efficiency between the heat exchange medium and the thermoelectric element 8, heat exchange parts 9a and 10a on the thermoelectric element 8 side are provided.
The inner walls of the heat exchange parts 9a and 10a are formed into an uneven shape.
The contact area (heat exchange area) between the inner wall of the heat exchange medium and the heat exchange medium is expanded.

In this embodiment, the pipes 9b and 10b constituting the thermosiphon 9.10 are thin refrigerant pipes with an inner diameter of about 3 to 10III11, which are commonly used in refrigerators, etc., to reduce costs. Even in this case, since the thermosiphons 9 and 10 are configured in a closed loop configuration, the circulation of the heat exchange medium (heat transport) is performed smoothly even if the pipes 9b and 10b are thin.

Next, the operation of the above configuration will be explained.

When the thermoelectric element 8 is energized to start cooling, a phenomenon occurs in which heat is absorbed from the heat absorbing surface 8a of the thermoelectric element 8 and released from the heat dissipating surface 8b due to the Bertier effect, thereby causing the thermosiphons 9 on both sides to The heat exchange medium in the chamber 10 is naturally circulated by phase change and the action of gravity to transport heat. The principle of heat transport by this thermosiphon 9.10 is that the heat exchange medium in the heat exchange parts 9c and 10a on the high temperature side absorbs heat from the outside and evaporates, so that the heat exchange medium with a reduced density becomes thermostatic. The heat exchange medium rises inside the siphon 9.10 and reaches the heat exchange parts 9a and 10c on the low-temperature side, where it radiates heat and liquefies again, so that the heat exchange medium, which has increased in density, is moved inside the thermosiphon 9.10 by gravity. The heat is transported by repeating the cycle of descending from the heat source to the heat exchange parts 9c and 10a on the high temperature side. Therefore, the thermosiphon 9 on the heat absorption side (inside the refrigerator) cools the interior of the refrigerator by absorbing the heat inside the refrigerator in the inside heat exchange part 9c, and converts the heat absorbed from the inside of the refrigerator into a thermoelectric converter by circulating the heat exchange medium. It is transported to the heat absorption surface 8a of the element 8. The heat absorbed in the thermoelectric cord 8 is transferred from the heat radiation surface 8b to the heat exchange medium in the thermosiphon 10 on the heat radiation side (outside the refrigerator), and due to the circulation of this heat exchange medium, the heat exchange medium in the thermosiphon 10 is heated. It is radiated to the outside of the refrigerator from the outside heat exchange section 10c. In this way, it is possible to promote the transport of heat from the inside of the refrigerator to the outside of the refrigerator by the circulation of the heat exchange medium using phase change and gravity.
It is possible to have a heat transport capacity of about 0 to 100 times, which makes it possible to efficiently cool the interior of the refrigerator, greatly improve the cooling efficiency of the interior of the refrigerator, and expand the internal volume of the refrigerator.

By the way, as mentioned above, heat transport by a thermosiphon is carried out by naturally circulating the heat exchange medium using gravity, so the heat transport efficiency (circulation efficiency of the heat exchange medium)
In order to increase this, it is important to use gravity effectively.

In this regard, in the embodiment, the center position C1 of the inside heat exchange part 9C of the thermosiphon 9 on the heat absorption side (inside the refrigerator) is set lower than the center position C6 of the heat absorption surface 8a of the thermoelectric element 8.
Since the center position C2 of the outside heat exchange part 10c of the thermosiphon 10 on the heat radiation side (outside the refrigerator) is set higher than the center position C6 of the heat radiation surface 8b of the thermoelectric cord 8, both thermosiphons 9
. ) is lower than the center position of
Gravity can be effectively used to promote natural circulation of the heat exchange medium, improving heat transport efficiency and improving cooling efficiency.

Moreover, since the inner walls of the heat exchange parts 9a and 10a on the thermoelectric element 8 side of the thermosiphons 9 and 1o on both sides are formed in an uneven shape, the contact area between the inner walls of the heat exchange parts 9a and 10a and the heat exchange medium (Heat exchange area) can be expanded, and heat transfer efficiency between the two can be improved, and this aspect can also contribute to improving cooling efficiency.

Furthermore, since the heat exchange parts 9a and 10a on the thermoelectric element 8 side of the thermosiphons 9 and 1o are formed into a box shape larger than the thermoelectric element 8, the heat exchange parts 9a and 10a are connected to the heat absorption surface 8a of the thermoelectric element 8. The heat exchange portion 9a can be completely brought into close contact with the entire heat radiation surface 8b.

Heat transfer efficiency between the thermoelectric element 10a and the thermoelectric element 8 can be improved.

Further, since the thermosiphons 9 and 10 are configured in a closed loop type, even if the pipes 9b, 10. Even if b is thin, circulation of the heat exchange medium (heat transport) can be performed smoothly, and sufficient heat transport efficiency can be ensured. In this case, the pipes 9b and 10b constituting the thermosiphons 9 and 10 are
Inner diameter 3~], O++ commonly used in refrigerators, etc.
Since it is possible to use a refrigerant pipe as thin as 100 nm, there is also the advantage that costs can be reduced.

On the other hand, FIGS. 3 to 5 show a second embodiment of the present invention. In this second embodiment, the inside heat exchange part 13c of the thermosiphon 13 on the heat absorption side (inside the refrigerator) is The metal inner plate 1 of the heat insulating wall 5 is
The inner plate 14 is arranged in a meandering manner along the back surface of the cooling device 4, and its inner plate 14 serves as a cooling surface, and has a structure similar to that of a so-called pipe-on-sheet type cooler. In order to improve heat transfer (adhesion) between the inside heat exchange part 13c and the inside plate 4, the inside heat exchange part 13c is bonded to the inside plate 14. In this case, the inner plate 14 constitutes the back surface and top surface of the cooling chamber 6, and the left and right side surfaces and bottom surface of the cooling chamber 6 constitute the first
It is composed of an inner box 15 as in the embodiment. Also,
The upper surface (inside plate 14) of the cooling chamber 6 is inclined diagonally upward toward the door 7 side. One of the reasons for this is to prevent as much as possible the upward flow of the heat exchange medium whose density has been reduced by vaporization within the inside heat exchange section 13c. Another reason is that depending on outside air conditions and load conditions, water droplets may condense on the lower surface of the inner plate 14, which is the cooling surface, so care must be taken to ensure that the water droplets flow down to the back side without falling onto the food. This is what I did.

On the other hand, the outside heat exchange part 16c of the thermosiphon 16 on the heat radiation side (outside the refrigerator) is bent in a meandering manner to enlarge the contact area (heat exchange area) with the air, as shown in FIG. There is. Similar to the first embodiment, the outer side heat exchange section 16c is provided with a large number of fins 17 to enhance heat dissipation. Other parts that are the same as those in the first embodiment described above are given the same reference numerals and their explanations will be omitted.

In the second embodiment, the inside heat exchange part 13c of the thermosiphon 13 on the heat absorption side (inside the refrigerator) is connected to the inside plate 1 of the heat insulating wall 5.
Since the thermosiphon 13 is arranged along the back surface of the cooling chamber 6, there is no need to expose the thermosiphon 13 inside the cooling chamber 6, which has the advantage of improving the appearance of the inside of the cooling chamber 6 and expanding the effective volume of the cooling chamber 6. .

In addition, in each of the above embodiments, the thermosiphon 9, 10.13
．． 16 thermoelectric element 8 side heat exchange part 9a.

In order to make the inner wall of 10a uneven, it was formed into a rectangular wave shape, but it could also be formed into a triangular wave shape, or the inner wall could be surface treated with a coarse mesh sander to form countless minute unevenness. Furthermore, a large number of protrusions (various shapes and arrangements are possible) may be formed on the inner wall.

In addition, the present invention can be modified in various ways, such as a configuration in which an electric fan for forcibly cooling the outside heat exchange parts 10c and 16c of the thermosiphon 10.16 on the heat radiation side (outside the refrigerator) is provided.

[Effects of the Invention] As is clear from the above description, the present invention includes thermosiphons each containing a heat exchange medium installed on the heat absorption side and the heat radiation side of a thermoelectric element so as to be able to exchange heat. While cooling the inside of the refrigerator, the thermosiphon on the heat dissipation side dissipates the heat of the thermoelectric element to the outside of the refrigerator, so that the heat exchange medium is circulated from the inside of the refrigerator to the outside of the refrigerator using phase change and gravity. It is possible to promote the transfer of heat, greatly improving the cooling efficiency inside the refrigerator, and making it possible to expand the internal volume of the refrigerator.

In this case, the center position of the inside heat exchange part of the thermosiphon on the heat absorption side is set lower than the center position of the heat absorption surface of the thermoelectric element, and the center position of the outside heat exchange part of the thermosiphon on the heat radiation side is set lower than the center position of the heat exchange part of the heat absorption side of the thermoelectric element. If it is set higher than the center position of the heat radiation surface, the center position of the heat exchange part on the high temperature side of both thermosiphons (the part where the density of the heat exchange medium decreases due to vaporization) will be higher than the center position of the heat exchange part on the low temperature side (the part where the density of the heat exchange medium decreases due to vaporization). Since it is lower than the center position of the portion (which becomes larger due to liquefaction), it is possible to effectively utilize gravity to promote natural circulation of the heat exchange medium, and improve heat transport efficiency.

Furthermore, if the inner walls of the heat exchange parts on the thermoelectric element side of both thermosiphons on the heat absorption side and the heat radiation side are formed in an uneven shape, the contact area (heat exchange area) between the inner wall of the heat exchange parts on the thermoelectric element side and the heat exchange medium can be increased.
can be expanded, and the heat transfer efficiency between the two can be improved.

In addition, if the heat exchange part inside the refrigerator of the thermosiphon on the heat absorption side is placed along the back side of the inner plate of the heat insulating wall of the refrigerator body, and the inner plate is used as the cooling surface, the thermosiphon is exposed inside the refrigerator. This makes it possible to improve the appearance of the inside of the refrigerator and expand the effective volume of the inside of the refrigerator.

[Brief explanation of the drawing]

Figures 1 and 2 show a first embodiment of the present invention, with Figure 1 being a longitudinal sectional side view of the whole, and Figure 2 being a perspective view of the heat exchanger on the thermosiphon side. . 3 to 5 show the second embodiment of the present invention, and the third embodiment shows the second embodiment of the present invention.
The figure is a longitudinal side view of the whole, Figure 4 is a perspective view showing the arrangement of thermosiphons on the heat absorption side (inside the refrigerator), and Figure 5 is a perspective view showing the arrangement of thermosiphons on the heat radiation side (outside the refrigerator). be. In the drawing, 1 is the refrigerator body, 2 is the outer box, 3 is the inner box, 4 is the insulation material, 5 is the insulation wall, 6 is the cooling chamber (inside the refrigerator), 8 is the thermoelectric element, 8a is the heat absorption surface, 8b is the heat radiation 9 is the thermosiphon on the heat absorption side, 10 is the heat exchanger on the heat radiation side, 10c is the outside heat exchanger, 11 and 12 are fins, 13 is the thermosiphon on the heat absorption side, 14 is the inner plate, 16 is the heat radiation side 17 is a fin.

Claims (1)

[Scope of Claims] 1. In an electronic refrigerator using a thermoelectric element as a cold heat source, thermosiphons each containing a heat exchange medium are disposed on the heat absorption side and the heat radiation side of the thermoelectric element to enable heat exchange, and the heat absorption side An electronic refrigerator characterized in that the inside of the refrigerator is cooled by a thermosiphon, and the heat of the thermoelectric element is radiated outside the refrigerator by a thermosiphon on the heat radiation side. 2. The center position of the inside heat exchange part of the thermosiphon on the heat absorption side is lower than the center position of the heat absorption surface of the thermoelectric element, and the center position of the outside heat exchange part of the thermosiphon on the heat radiation side is set lower than the center position of the heat exchange part of the outside side of the thermoelectric element. 2. The electronic refrigerator according to claim 1, wherein the electronic refrigerator is located higher than the center position of the electronic refrigerator. 3. The electronic refrigerator according to claim 1 or 2, characterized in that the inner walls of the thermoelectric element side heat exchange portions of both the thermosiphons on the heat absorption side and the heat radiation side are formed in an uneven shape. 4. Claim 1, characterized in that the inside heat exchange part of the thermosiphon on the heat absorption side is arranged so as to be aligned with the back surface of the inner plate of the heat insulating wall of the refrigerator main body, and the inner plate is used as the cooling surface.
4. The electronic refrigerator according to any one of 3 to 3.