EP0645593B1

EP0645593B1 - Electronic cooling type refrigerator

Info

Publication number: EP0645593B1
Application number: EP94115141A
Authority: EP
Inventors: Izumi C/O Fuji Electric Co. Ltd. Higashi; Riichi C/O Fuji Electric Co. Ltd. Sawano
Original assignee: Fuji Electric Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 1993-09-28
Filing date: 1994-09-26
Publication date: 1997-09-10
Anticipated expiration: 2014-09-26
Also published as: EP0645593A1; JPH0791796A; DE69405504T2; DE69405504D1

Description

Background of the Invention and Related Art Statement

The present invention relates to an electronic cooling type refrigerator directed to a portable cooler or cooling box for cooling the inside of the box by utilizing Peltier effect of an electronic type thermo-module using thermo-electric cooling elements.
An electronic cooling type refrigerator is known in Japanese Patent Publication (KOKOKU) No. 5-17469, wherein an electronic type thermo-module using thermo-electric cooling elements is assembled in a heat insulating housing or box of the refrigerator for cooling the inside of the housing by utilizing Peltier effect of the thermo-module.
Figs. 3 and 4 show a structure of a conventional electronic cooling type cooling box, wherein numeral 1 is a heat insulating housing and numeral 2 is a lid thereof. In a side wall of the heat insulating housing 1, an electronic type thermo-module 3 having a plain plate shape and formed of thermo-electric cooling elements is assembled such that a heat absorbing side of the thermo-module 3 is oriented inside the housing 1 and the heat radiating side thereof is oriented outside the housing 1.
The thermo-module 3 is a plain shape module, which is formed of a plurality of thermo-electric cooling elements assembled in series. Each cooling element is formed such that P type and N type semiconductor elements are connected between two ceramic base boards in the form of a small character pi in a Greek letter.
A heat absorbing member 4 with fins is heat-conductively fixed to the heat absorbing side of the thermoelectric module 3, and a heat radiating member 5 with fins is heat-conductively fixed to the heat radiating side thereof. A wind channel 6 is formed outside the housing 1 to surround the fins 5a of the heat radiating member 5, and an outside fan 7 is attached to the wind channel 6 to supply outer air to the fins 5a. Numeral 8 is a direct current electric source, such as a battery, to supply electricity to the thermo-module 3.
In the conventional electronic cooling type refrigerator as stated above, since heat exchange between air inside the housing 1 and the heat absorbing member 4 is made based on a natural air convection, heat exchange efficiency is low. Thus, the cooling efficiency of the thermo-electric module has not been sufficiently obtained.
DE-A-36 39 089 discloses an electronic cooling type refrigerator comprising a flat thermoelectric module installed in an insulated housing, a heat absorbing member with fins situated inside the housing and heat-conductively connected to a heat absorbing side of the module, and an inner fan situated inside the housing and forcibly supplying air in the housing towards the fins of the heat absorbing member. If required, a plurality of thermoelectric modules may be used either in series or parallel arrangement.
While such inner fan improves the air convenction inside the insulated housing, and thereby achieves better heat exchange, it requires substantial space, and the available space capacity inside the insulated housing for receiving articles to be cooled is thereby considerably reduced.
The present invention has been made with reference to the above drawbacks, and is to provide an electronic cooling type refrigerator, wherein the cooling efficiency inside the refrigerator is improved, while providing maximum space for the goods to be cooled, and the refrigerator can be used easily.

Summary of the Invention

In order to accomplish the above object, the electronic cooling type refrigerator of the envention has the following structures :

(1) the refrigerator includes at the inner side thereof a heat absorbing member with fins heat-conductively connected to a heat absorbing side of a thermoelectric module, and an inner fan for forcibly supplying air in the refrigerator to the fins of the heat absorbing member arranged in rows.
(2) According to the invention, in the structure as stated in the above pragraph (1), the inner fan is assembled inside the fins of the heat absorbing member arranged in rows.

In a preferred embodiment, the thermo-module is vertically arranged and is installed in a wall of a housing of the refrigerator, and the fins of the heat absorbing member connected to the heat absorbing side of the thermo-module are arranged vertically. Also, a drain receiver is provided at a lower side of the heat absorbing member for receiving dew dropping from the fins arranged in the rows and draining outside the housing.
Further, a plurality of thermoelectric modules heat-conductively laminated and assembled in the heat insulating housing may be provided.
In the above structure, air inside the housing is forcibly supplied by the inner fan to the rows of the fins of the heat absorbing member projecting into the housing, so that heat exchange rate between the heat absorbing member and air inside the housing is increased several times when comparing the natural convection system. Thus, it is possible to sufficiently exhibit the cooling ability of the electronic type thermo-module. Since the inner fan is installed inside the fins of the heat absorbing member arranged in the rows, the limited space inside the housing is effectively utilized.
Also, a plurality of thermoelectric modules is laminated and arranged together as the thermo-module, so that the difference of temperature between the heat absorbing side and the heat radiating side is effectively increased. Thus, the cooling ability can be increased. Also, the fins of the heat absorbing member is vertically arranged, and the drain receiver is provided at the lower side of the heat absorbing member for receiving the dew flowing along and dropping from the fins and discharging the dew outside the housing. Thus, it is possible to easily discharge the dew formed on the surfaces of the heat absorbing fins to the outside of the housing through the drain receiver.

Brief Description of the Drawings

Fig. 1 is a vertical section view for showing a structure of an embodiment of the invention;
Fig. 2 is a lateral section view of the embodiment shown in Fig. 1;
Fig. 3 is a vertical section view for showing a structure of a conventional electronic cooling type refrigerator; and
Fig. 4 is a lateral section view of the refrigerator shown in Fig. 3.

Detailed Description of a Preferred Embodiment

The embodiment of the invention is explained herein below with reference to Figs. 1 and 2. In the drawings, the same members as shown in Figs. 3 and 4 have the same numerals.
Namely, in the structure of the embodiment as shown in the drawings, a flat thermoelectric module 3, in a plain plate shape, is vertically built or installed in a side wall of a heat insulating housing 1 such that a heat absorbing side is directed inside the housing 1. A heat absorbing member 4 with fins 4a (aluminum extruded product) is heat-conductively fixed to the thermo-module 3 at the inside of the housing 1. An inner fan 9 is built in the fins 4a or the rows ofthe fins 4a of the heat absorbing member 4. Air inside the housing 1 is forcibly supplied to the fins 4a of the heat absorbing member 4 by the inner fan 9.
On the other hand, a heat radiating side of the thermo- module 3 is connected to a heat pipe 11 through a heat radiating block 10, and the heat pipe 11 extends to an inside of a wind channel 6. Radiating fins 11a of the heat pipe 11 are cooled by an outer fan 7. Further, the fins 4a of the heat absorbing member 4 are arranged vertically, and the lower portions thereof are cut diagonally. A drain receiver 12 is provided below the fins 4a, and a drain pipe 12a extending from the drain receiver 12 penetrates through the housing 1 and is drawn outside the housing.
In the above structure, when an electricity is supplied to the thermoelectric-module 3 in a predetermined direction from a direct current source 8, heat absorption occurs inside the housing and heat radiation occurs outside the housing to thereby cool the heat absorbing member 4 by Peltier effect known already. The heat generated from the thermo-module 3 is radiated to atmosphere through the heat pipe 11.
On the other hand, inside the housing air in the housing is forcibly circulated by the inner fan 9, which is operated by means of the direct current source 8, toward the fins 4a of the absorbing member 4, so that high energy exchange is made. Thus, the space inside the housing is effectively and equally cooled.
Dew formed on the surfaces of the fins of the heat absorbing member 4 due to cooling of the inside of the housing flows along the surfaces of the fins 4a and drops from the lower ends thereof diagonally cut to the drain receiver 12, which is then discharged outside the housing through the drain pipe 12a. Thus, inconveniences, such as accumulation of water in the housing 1, do not occur. plate
The thermoelectric module 3 in the plain plate shape generally sold in a market has a thickness of about 3.5-5 mm, and the heat absorbing side and the heat radiating side are electrically isolated by a ceramic plate with high heat- conductivity. The difference of the temperature between the heat absorbing side and the heat radiating side is slightly above ten degrees centigrade. Therefore, in a cooler or cooling box used outside a house with high atmospheric temperature in a summer time, sufficient cooling ability may not be obtained if one thermo-module is used, though it depends on the capacity of the cooler.
Therefore, in the present invention, a plurality (two or three) of thermo-modules is heat-conductively laminated together and assembled in the housing 1, so that the temperature difference between the inside and outside of the housing is effectively increased to thereby strengthen the cooling efficiency. In this case, it is preferable to reduce the heat conductive resistance by, for example, coating heat conductive grease between the contact surfaces of the respective thermo- modules.
Incidentally, the above example refers to a portable cooler or a cooling box, but the present invention may be used as a refrigerator with a small capacity fixed in a guest room of a hotel, or a cooling and heating box for cooling or heating the inside of the box by changing the direction of electricity supplied to the electronic thermo-module.
As explained above, in accordance with the structure of the invention, the following advantages are obtained:

The inner fan is installed inside the housing, and air inside the housing is forcibly supplied toward the heat absorbing member with the fins, which is heat-conductively attached to the thermoelectric module. Thus, it is possible to increase the heat exchange efficiency several times more than the conventional natural convection system to thereby efficiently cool the inside of the housing. Also, since the inner fan is built in the fins of the heat absorbing member arranged in the rows, the housing space can be effectively utilized.
(2) Also, since the drain receiver is provided under the heat absorbing member, it is convenient to drain dew formed on the surfaces of the fins outside the housing.
(3) Since a plurality of the electronic type thermo-modules is laminated in use, the temperature difference between the heat absorbing side and the heat radiating side is increased to thereby improve the cooling efficiency.

Claims

Electronic cooling type refrigerator comprising a flat thermo-electric module (3) installed in an insulating housing (1) to cool an inside of the housing by utilizing the Peltier effect of the thermoelectric module comprising
a heat absorbing member (4) with fins (4a) situated inside the housing and heat-conductively connected to a heat absorbing side of the module, and

an inner fan (9) situated inside the housing for forcibly supplying air in the housing toward the fins (4a) of the heat absorbing member arranged in rows,
characterized in that the inner fan (9) is built in the fins of the heat absorbing member (4) arranged in the rows.
Electronic cooling type refrigerator according to claim 1, wherein the module (3) is arranged vertically to be installed in a side wall of the housing (1), and the fins of the heat absorbing member (4) fixed to the heat absorbing side of the thermoelectric module (3) are arranged vertically, a drain receiver (12) being provided under the heat absorbing member (4) to receive dew dropping from the fins and to drain outside the housing (1).
Electronic cooling type refrigerator according to claim 1 or 2, wherein a plurality of modules (3) is heat-conductively laminated together and is built in the housing (1).