JPH10318624A - Electronic cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive electronic cooler having high cooling effect which can be made compact while reducing the weight. SOLUTION: The electronic cooler comprises a Peltier element 4, a heat radiating fin 5 disposed on the heat radiating side of the Peltier element 4, a cooling liquid 13 touching a part of the heat radiating fin 5, and means 9 for supplying the air to the surface of the cooling liquid 13 and a part of the heat radiating fin 5 exposed therefrom. The heat radiating fin 5 is cooled through action of the evaporation latent heat incident to evaporation of the cooling liquid 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic cooling device used as a cooling plate unit or the like, and more particularly to an electronic cooling device using a cooling liquid such as water on a heat radiation side.

[0002]

2. Description of the Related Art As a heat radiation means of an electronic cooling device, an air cooling system combining a fan and fins and a water cooling system using water are generally used, and various proposals have been made so far.

[0003]

The air-cooling system has a feature that its structure is simple. However, the air-cooled system has a small thermal conductance between air and fins,
In order to perform sufficient cooling (extremely low-temperature cooling and / or rapid cooling) with an electronic cooling device, it is necessary to use a heat conductor having a large heat radiation area and to increase the air flow from a fan. For this reason, there is a problem that the size of the apparatus is increased, there is a problem such as noise caused by air blowing, and the use is limited.

[0004] On the other hand, the water cooling system has a large specific heat of water and a large thermal conductance, and thus is suitable for use for sufficiently cooling. However, the water cooling system requires a circulation system for circulating water, a pump, a radiator and a fan for radiating heat to the outside air, the structure is complicated, the device is large and heavy, and the cost and power consumption of the device are required. There are big economic problems.

An object of the present invention is to provide an inexpensive electronic cooling device which solves the above-mentioned drawbacks of the prior art, has a high cooling effect, can be made compact and lightweight, and is inexpensive.

[0006]

In order to achieve the above object, the present invention relates to a Peltier device, a radiating fin provided on a heat radiation side of the Peltier device, and water, for example, which contacts a part of the radiating fin. And a blower means such as a blower fan for sending air to the liquid surface of the cooling liquid and the radiating fins exposed from the cooling liquid. The heat radiation fin is configured to be cooled by the heat radiation from the surface of the heat radiation fin and the action of the latent heat of vaporization accompanying the evaporation of the cooling liquid.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 4 are views for explaining a first embodiment of the present invention. FIG. 1 is a plan view of an electronic cooling device, FIG. 2 is a cross-sectional view taken along the line XX of FIG. 1, and FIG. -Y
4 is a control block diagram.

[0008] This embodiment shows an example in which the present invention is used as a tabletop cooling plate unit for holding a cooling state of cakes, dishes, foodstuffs, samples, chemicals, and the like. A cooling plate 2 made of a metal having good heat conductivity, such as aluminum, stainless steel, or copper, is provided.

A Peltier element 4 is provided on the lower surface of the cooling plate 2 via a heat absorbing heat conductor 3 made of aluminum. Although not shown, the Peltier element 4 includes a heat absorption side electrode, a heat radiation side electrode, and a number of P-type semiconductor layers and N-type semiconductor layers arranged between the two electrodes. P
The type semiconductor layer and the N-type semiconductor layer are arranged structurally and thermally in parallel, but are electrically connected in series via the electrodes.

A radiating fin 5 is provided on the lower surface of the Peltier element 4.
Are in close contact. The radiating fins 5 include a fin base 6 and a number of thin fins 7 extending in parallel.
Is in contact with the bottom surface of the casing 1. A heat insulating layer 8 is provided between the cooling plate 2 and the radiation fins 5. Note that the heat insulating layer 8 can be raised up to the outer peripheral portion of the cooling plate 2 in order to ensure the heat retaining effect.

A small blower fan 9 and a self-supplying water supply tank 10 are provided adjacent to the cooling plate 2, and an intake port 11 (see FIG. 1) is provided at a position where the blower fan 9 is installed. The exhaust port 12 is on the opposite side of the port 11,
Each is formed. A predetermined amount of cooling water 13 is injected into the bottom of the casing 1, a part of the fins 7 is immersed in the water 11, and a ventilation space 14 is formed between the water surface and the fin base 6. 14 is divided into a large number of fins 7, and the intake port 11 and the exhaust port 1
2 is connected.

As shown in FIG. 2, a liquid level sensor 15 is provided on a side wall of the casing 1. As shown in FIG. 1, a rotary type adjustment switch 16 also serving as a main switch is provided on the upper surface of the casing 1 so that the cooling intensity (2) and the cooling intensity (1) can be adjusted. An indicator lamp 17 is provided adjacent to the adjustment switch 16.

As shown in FIG. 4, signals from the liquid level sensor 15 and the adjustment switch 16 are input to a control unit 18 comprising a CPU.
7, output to the element power supply section 19 and the fan power supply section 20.

Next, the operation of the cooling device will be described. When the adjustment switch 16 is turned to adjust the cooling intensity (2) or weakness (1), the Peltier element 4 and the blower fan 9 are energized accordingly. Then, the cooling plate 2 is cooled by the Peltier effect via the heat absorbing heat conductor 3, and the heat taken from the cooling plate 2 side is transferred to the radiation fin 5 side. By the rotation of the blower fan 9, air is sucked from the intake port 11 and flows between the fins 7 (the ventilation space 14) as shown by arrows in FIG. The fin 7 is efficiently and continuously cooled by both the heat radiation from the surface thereof and the latent heat of evaporation accompanying the evaporation of the water 13. The air that has passed through the ventilation space 14 is discharged outside through the exhaust port 12.

While the electronic cooling device has been used for a long time, the water 13 in the casing 1 evaporates and decreases, but the water 13 is automatically replenished from the water refilling tank 10. When the water supplement tank 10 becomes empty and the water 13 in the casing 1 becomes lower than a predetermined level, the liquid level sensor 15 detects this and outputs a detection signal to the control unit 18. Then, the display lamp 17 is turned on by a control signal from the control unit 18, and
The user is notified that the water refill tank 10 is empty and the water 13 in the casing 1 is insufficient, and the element power supply unit 19
The power supply to the fan power supply unit 20 is stopped to avoid wasteful power consumption.

FIG. 5 shows that the input power to the Peltier element (hereinafter referred to as element power) is constant (12 V × 4.5).
A), the electric power of the blower fan (corresponding to the air volume and wind speed.
When the fan power is changed, the relationship between the fan power and the temperature of the radiating fins (hereinafter referred to as the cooling surface temperature), the fan power and the total power (the sum of the element power and the power supplied to the blower fan) FIG. 6 is a characteristic diagram showing the relationship of FIG.

In the figure, line A is a line indicating the relationship between the fan power and the cooling surface temperature, line B is a line indicating the relationship between the fan power and the total power, and the points plotted by ○ indicate the case where there is no water (air cooling). )
Points indicating the relationship between the fan power and the cooling surface temperature, and the points plotted by the squares indicate the relationship between the fan power and the total power when there is no water (air cooling).

As can be seen from the figure, in the case of the present invention, the cooling surface temperature can be drastically reduced by slightly increasing the fan power (the total power is hardly changed), and the air cooling is performed with the same total power. In the present invention, when the cooling surface temperature is 4 ° C. (see the points marked with “○”), the present invention cools down to −1 ° C., and it can be proved that the cooling effect is very high.

FIG. 6 is a characteristic diagram showing the relationship between the device power and the cooling surface temperature, and the relationship between the device power and the total power when the fan power is kept constant and the device power is changed.
Line C is a line showing the relationship between the device power and the cooling surface temperature when the fan power is 6 V × 0.03 A, and line D is the device power and the cooling surface temperature when the fan power is 12 V × 0.08 A. Line E indicates the fan power is 6 V × 0.0
A line indicating the relationship between the element power and the total power at 3 A, a line F is a line indicating the relationship between the element power and the total power at a fan power of 12 V × 0.08 A, and points plotted with ○ marks Is a point indicating the relationship between the element power in the absence of water and the cooling surface temperature, and a point plotted by □ is a point indicating the relationship between the element power and the total power in the absence of water (air cooling).

As can be seen from this figure, comparing the present invention with the air-cooled one (marked with ○), it can be proved that there is a large difference in the cooling effect at the same total power (element power).

As is apparent from a comparison between FIG. 5 and FIG. 6, it is found that the cooling effect is more easily obtained by changing the fan power than by increasing the element power. This enables highly efficient electronic cooling with low power consumption.

FIG. 7 is a characteristic diagram showing the relationship between the fan power and the amount of water evaporation per hour. The line G in the figure is a line indicating the relationship between the fan power and the cooling surface temperature, and the line H is a line indicating the relationship between the fan power and the amount of water evaporation. As is evident from this figure, the cooling surface temperature decreases rapidly with the increase in fan power, but the amount of water evaporation increases with this, and the evaporation of water effectively acts to lower the temperature of the cooling surface. You can see that it is.

FIGS. 8 and 9 are views for explaining a second embodiment of the present invention. FIG. 8 is a plan view of the electronic cooling device, and FIG. 9 is a cross-sectional view taken along the line Z-Z in FIG. The difference between this embodiment and the above embodiment is that the cooling plate 2
Is a container shape, and a lid 21 is formed. Another difference is that a plurality of Peltier elements 4 are arranged at a predetermined distance from the cooling plate 2.

FIG. 10 is a view for explaining a third embodiment of the present invention. The surface of the fin 7 is treated with a hydrophilic polymer material such as an acrylic resin or a polyvinyl alcohol resin. Alternatively, the liquid retaining layer 22 is formed by adhering a water absorbing material such as a nonwoven fabric or a woven fabric.

FIG. 11 is a view for explaining a fourth embodiment of the present invention. The fin 23 has a wick 23 formed on the surface of the fin 7 having an extremely fine vertical groove or fine unevenness. By forming the liquid retaining layer 22 and the wick 23 on the surface of the fin 7 as described above, a thin liquid film is formed on the fin 7 and the water 1
3 can be promoted, and a higher cooling effect can be obtained.

FIG. 12 is a view for explaining a fifth embodiment of the present invention, in which the radiation fins 5 are in the shape of a container.
A predetermined amount of water 13 is injected therein. Radiation fins 5
A part of the side wall is cut out to form an exhaust port 12, and the upper opening of the radiation fin 5 is closed by a cover member 24, and a ventilation space 14 is formed between the water surface and the cover member 24.

A Peltier element 4 is provided on the lower surface of the radiation fin 5.
The cooling plate 2 is in close contact with the heat-absorbing heat conductor 3.

The air sent from a blower fan (not shown) passes between the fins 7 and is exhausted from an exhaust port 12. The fin 7 is provided with heat and water 13
Is efficiently and continuously cooled by the action of both of the latent heat of vaporization caused by the evaporation of water.

In the above embodiment, the case of a thin fin has been described. However, the present invention is not limited to this. For example, a fin having another shape such as a pin fin or a corrugated fin may be used. .

[0030]

According to the first aspect of the present invention, there is provided a Peltier device, a radiating fin provided on a radiating side of the Peltier device, a cooling liquid in contact with a part of the radiating fin, and a liquid of the cooling liquid. And a blower for sending air to a portion of the radiating fin exposed from the surface and the cooling liquid. The radiating fin is cooled by the action of heat radiation from the surface of the radiating fin and latent heat of vaporization accompanying evaporation of the cooling liquid. It is characterized by having such a configuration.

Therefore, there is no need to use a large heat conductor as in a simple air cooling system or to increase the air volume by a fan. Also, unlike the water-cooled system, there is no need for a circulation system for circulating liquid, a pump, a radiator, etc., providing a high cooling effect, making the device compact and lightweight, and providing a low-cost electronic cooling device can do.

If the cooling liquid replenishing means for replenishing the loss due to the evaporation of the cooling liquid is provided, a high cooling effect can be maintained for a long period of time.

According to a third aspect of the present invention, an element power supply section for driving the Peltier element, a blower power supply section for driving the blower, a liquid level sensor for monitoring the holding amount of the cooling liquid, and a signal from the liquid level sensor. A control unit that inputs a detection signal and outputs a control signal to the element power supply unit and the blower power supply unit, and the control unit controls the element power supply unit based on a liquid shortage detection signal from the liquid level sensor. And outputting a drive stop control signal to the blower power supply unit, it is possible to avoid wasteful power consumption when the cooling liquid runs short.

According to a fourth aspect of the present invention, a liquid retaining layer for absorbing and retaining the cooling liquid is provided on a surface of the radiating fin exposed from the cooling liquid. When the wick is provided on the surface in contact with the fin, the evaporation of the cooling liquid on the radiation fins is promoted, and a higher cooling effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of an electronic cooling device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken on line XX of FIG. 1;

FIG. 3 is a sectional view taken on line YY of FIG. 1;

FIG. 4 is a control block diagram of the electronic cooling device.

FIG. 5 is a characteristic diagram showing a relationship among fan power, cooling surface temperature, and total power.

FIG. 6 is a characteristic diagram showing a relationship among element power, cooling surface temperature, and total power.

FIG. 7 is a characteristic diagram showing a relationship among fan power, cooling surface temperature, and water evaporation.

FIG. 8 is a plan view of an electronic cooling device according to a second embodiment of the present invention.

FIG. 9 is a sectional view taken on line ZZ of FIG. 8;

FIG. 10 is a partially enlarged cross-sectional view of a radiation fin used in an electronic cooling device according to a third embodiment of the present invention.

FIG. 11 is a partially enlarged side view of a radiation fin used in an electronic cooling device according to a fourth embodiment of the present invention.

FIG. 12 is a sectional view of an electronic cooling device according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Cooling plate 3 Heat absorption side heat conductor 4 Peltier element 5 Radiation fin 6 Fin base 7 Fin 9 Ventilation fan 10 Water supplement tank 11 Intake port 12 Exhaust port 13 Water 14 Ventilation space 15 Liquid level sensor 16 Adjustment switch 17 Display lamp 18 Control Unit 19 Element power supply unit 20 Fan power supply unit 22 Liquid retention layer 23 Wick

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hideo Watanabe 1-7-7 Shiohama, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Thermobonic Co., Ltd.

Claims (7)

[Claims] 1. A Peltier device, a radiating fin provided on a heat radiation side of the Peltier device, a cooling liquid in contact with a part of the radiating fin, a liquid surface of the cooling liquid and exposed from the cooling liquid. Blowing means for sending wind to the radiating fin portion, and radiating heat from the surface of the radiating fin,
An electronic cooling device, wherein the cooling fin is configured to be cooled by the action of latent heat of evaporation accompanying the evaporation of the cooling liquid. 2. The electronic cooling device according to claim 1, further comprising cooling liquid replenishing means for replenishing a loss accompanying evaporation of the cooling liquid. 3. An element power supply section for driving the Peltier element, a blower power supply section for driving the blower, a liquid level sensor for monitoring the holding amount of the cooling liquid, and a liquid level thereof. A control unit for inputting a detection signal from a sensor and outputting a control signal to the element power supply unit and the blower power supply unit, based on a liquid shortage detection signal from the liquid level sensor, the control unit An electronic cooling device, which is configured to output a drive stop control signal to an element power supply unit and a blower power supply unit. 4. The electronic cooling device according to claim 1, wherein a liquid retaining layer for absorbing and retaining the cooling liquid is provided on a surface of the radiation fin exposed from the cooling liquid. 5. The electronic cooling device according to claim 1, wherein a wick is provided on a surface of the radiating fin in contact with the cooling liquid. 6. The electronic cooling device according to claim 1, wherein the radiating fin is formed in a container shape, and a predetermined amount of the cooling liquid is injected inside the radiating fin. 7. The electronic cooling device according to claim 1, wherein a cooling plate is provided on a heat absorbing side of the Peltier device.