US20050173097A1

US20050173097A1 - Liquid circulation type cooling system

Info

Publication number: US20050173097A1
Application number: US10/885,005
Authority: US
Inventors: Hironori Kitajima; Hitoshi Sakayori; Tadasi Takahashi
Original assignee: Hitachi Cable Ltd
Current assignee: Hitachi Cable Ltd
Priority date: 2004-02-10
Filing date: 2004-07-07
Publication date: 2005-08-11
Also published as: TWI302980B; KR20050080722A; CN100559924C; JP3897024B2; TW200526913A; CN1655666A; KR100605422B1; JP2005228810A

Abstract

A liquid circulation type cooling system includes a circulating pump for circulating a liquid, a heat exchanger disposed in a heat radiation space and for radiating heat outside the system. The heat exchanger contains a core unit, a liquid reservoir for storing the liquid positioned on the upstream side of the core unit and having a liquid opening, another liquid reservoir for storing the liquid and positioned on the downstream side of the core unit, the other liquid reservoir having a liquid opening, a heat-receiving member, a piping, and a fan for supplying air to the heat exchanger to effect forced air-cooling.

Description

The present application is based on Japanese patent application No. 2004-033761, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a liquid circulation type cooling system wherein a liquid is circulated in the system to transfer heat generated from a heat-generating element to a heat radiation space by means of the liquid thereby to radiate the heat, and particularly to a liquid circulation type cooling system mounted on an electronic instrument which may be positioned in the upside-down postures as a result of mounting the cooling system.
2. Description of the Related Art
In recent years, high-performance electronic instruments have been developed, so that a heat-generating amount of, particularly, circuit parts such as CPU (Central Processing Unit) and electric power unit contained in a main body increases. In this connection, improvements in heat radiation to the outside are desired.
As a means for promoting heat radiation of a heat-generating element, a cooling device wherein a radiator made of a metal excellent in thermal conductivity is attached to a heat-generating element such as CPU, and the radiator is air-cooled is known. However, a cooling device of an air-cooling type requires a heat radiation area for a radiator in response to an amount of heat radiation, resulting in a disadvantage of increasing a size of the cooling device. Besides, there is recently such a tendency that a heat-generating amount of a CPU increases accompanied with high-speed processability and multifunctionality required for electronic instruments. In this respect, heat radiation performance reaches substantially a limit in a cooling device of an air-cooling type.
For improving such poor heat radiation, a liquid circulation type cooling system wherein a heat transfer medium such as a coolant is used is known (for example, see Japanese patent application laid-open No. 2003-209210 (FIG. 2)).
FIG. 1 is a schematic diagram showing a circuit of a conventional liquid circulation type cooling system wherein the liquid circulation type cooling system 50 includes a circulating pump 51 for circulating a liquid, a heat-receiving member 53 attached to an element to be cooled such as a heat-generating element, the heat-receiving member being served for transferring efficiently heat from the element to be cooled to the liquid, a radiator 52 for radiating heat outside a casing of an instrument and disposed in a heat-radiating space, a liquid reservoir 56 positioned at the upper part of the radiator 52 and storing the circulating liquid, a header 57 positioned at the bottom of the radiator 52, a piping 54 for connecting respective components with each other and made of a flexible tube or a fixed piping, and a fan 55 for supplying wind to the radiator 52 to perform forced air-cooling.
In the liquid circulation type cooling system 50, when the circulating pump 51 is driven, a liquid is circulated in the circulating circuit, whereby heat generated from an element to be cooled such as a heat-generating element is received by the heat-receiving member 53 to transfer the heat to the liquid. The heat thus transferred is delivered to the radiator 52 by means of the circulating liquid, and the heated liquid is forcibly air-cooled by the fan 55 to radiate the heat.
In the above-described liquid circulation type cooling system 50, the liquid reservoir 56 is provided for such a purpose that an amount of liquid is kept constant in the system with taking permeation of the liquid from connecting sections and surfaces of respective components into consideration. In this connection, the cooling system 50 is required to have a sealed structure for preventing leakage of the liquid in the case when the cooling system is positioned close to electronic instruments. However, pressure changes appear dependent upon temperature changes in the system, if the cooling system has a sealed structure. Particularly, since a pressure increases as a result of a temperature rise of the liquid, the liquid reservoir 56 contains not only the liquid 56A, but also an air layer 56B so as to be capable of responding to pressure increase. Furthermore, when air enters in the circulating pump 51, the radiator 52, or the heat-receiving member 53, performance of the cooling system decreases remarkably, and thus, a position of the liquid reservoir 56 is usually kept at the highest position of the system.
In this respect, however, when a setting condition of an electronic instrument in use is fixed, it is possible to maintain always a position of the liquid reservoir 56 at the highest position in the instrument. When a setting posture of an electronic instrument is changed due to usability in a user, in other words, when the electronic instrument is positioned upside-down, the liquid reservoir 56 is positioned at the lowest part of the instrument.
FIG. 2 is a schematic diagram showing a circuit in the case when the liquid circulation type cooling system 50 of FIG. 1 is positioned upside-down wherein the header 57 is positioned at the top of the radiator 52, and a liquid flows from the radiator 52 in a direction to the circulating pump 51 through the header 57. However, since the air layer 57B resides in the upper part of the liquid 57A in the header 57, the air flows also into the piping 54 when the liquid flows into the piping 54 positioned on the downstream side of the header 57. If the air enters into the piping 54, circulating performance of the liquid decreases, and as a result, a circulating function of the system decreases remarkably.
There is a “projector” as an example of a case where a setting position of an electronic instrument is positioned upside-down in use. As to such projector, there is either a case where it is used in a floorstanding position, or a case where it is mounted to a ceiling for use. Accordingly, when a liquid circulation type cooling system is mounted on a “projector”, it is required to respond to such changes in a posture (upside-down positions) of the projector applied.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a liquid circulation type cooling system which is mounted to an electronic instrument, whereby the electronic instrument can be positioned in the upside-down postures.
In order to achieve the above-described object, a liquid circulation type cooling system according to the present invention comprises a member for receiving heat from a heat-generating element such as a semiconductor element; a reservoir for containing liquid to transfer heat; a radiator for radiating heat which is transferred through the liquid from the member; and a system for circulating the liquid among the reservoir, the radiator and the member wherein the radiator comprises a heat exchanger and a fan for forcibly supplying air to the heat exchanger.
In the liquid circulation type cooling system of the present invention, the reservoir functions as a header for supplying the liquid to a core unit of the heat exchanger.
In the liquid circulation type cooling system of the present invention, the cooling system operates even in the upside-down installation posture.
Furthermore, a liquid circulation type cooling system according to the present invention comprises a heat radiation space for radiating heat of liquid heated by a heat-generating element; and a system for circulating the liquid through the heat radiation space; the heat radiation space comprising a first liquid reservoir on a first side thereof; a second liquid reservoir on a second side thereof to be in series with the first liquid reservoir; the first and second liquid reservoir being vertically arranged at different levels; and liquid openings provided on the first and second liquid reservoirs to be connected to the liquid-circulating system wherein the liquid opening of the first liquid reservoir is filled with the liquid, even if the first liquid reservoir is positioned at an upper place than that of the second liquid reservoir, while the liquid opening of the second liquid reservoir is filled with the liquid, even if the second liquid reservoir is positioned at the upper place than that of the first liquid reservoir.
In the liquid circulation type cooling system of the present invention, the heat radiation space comprises a core unit provided between the first and second liquid reservoirs to be connected therethrough, thereby providing a heat exchanger.
Moreover, a liquid circulation type cooling system according to the present invention comprises a heat radiation space for radiating heat of liquid heated by a heat-generating element; and a system for circulating the liquid through the heat radiation space; the heat radiation space comprising a first liquid reservoir on a first side thereof; a second liquid reservoir on a second side thereof to be in series with the first liquid reservoir; the first and second liquid reservoirs being horizontally arranged at the same level; and liquid openings provided on the first and second liquid reservoirs to be connected to the liquid-circulating system wherein the liquid openings of the first and second liquid reservoirs are filled with the liquid, even if the cooling system is installed in the upside-down postures.
In the liquid circulation type cooling system of the present invention, the heat radiation space comprises a core unit provided between the first and second liquid reservoirs to be connected therethrough, thereby providing a heat exchanger.
In the liquid circulation type cooling system of the present invention, the heat exchanger has “corrugated straight fin core” type structure which comprises tubes, fins, and headers, the headers being served for the liquid reservoirs.
In the liquid circulation type cooling system of the present invention, a fan for supplying air to forcibly cool the heat exchanger is disposed outside the heat exchanger.
In the liquid circulation type cooling system of the present invention, the liquid reservoir is provided with a liquid level sensor for generating a warning signal in case of shortage of the liquid.
According to the liquid circulation type cooling system of the present invention, the liquid reservoirs each for storing a liquid are disposed on the upstream and the downstream sides of the heat radiation space, respectively, and at least the liquid opening of the liquid reservoir positioned at the downstream side is filled always with the liquid. Thus, even if the liquid circulation type cooling system is positioned in the upside-down postures, it is possible to prevent that air flows into the system other than the liquid reservoir. As a result, electronic instruments may be positioned in the upside-down postures, so that an applicable scope for the liquid circulation type cooling system can be broadened.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be explained in more detail in conjunction with appended drawings, wherein:
FIG. 1 is a schematic diagram showing a circuit of a conventional liquid circulation type cooling system;
FIG. 2 is a schematic diagram showing a circuit of the conventional liquid circulation type cooling system which is positioned upside-down;
FIG. 3 is a schematic diagram showing a circuit of a liquid circulation type cooling system according to a first embodiment of the present invention;
FIG. 4A is an enlarged side view showing a heat exchanger used in the liquid circulation type cooling system according to the first embodiment of the present invention;
FIG. 4B is an enlarged front view showing the heat exchanger of FIG. 4A;
FIG. 5 is a schematic diagram showing a circuit of the liquid circulation type cooling system according to the first embodiment of the present invention which is positioned upside-down;
FIG. 6 is a schematic diagram showing a circuit of a liquid circulation type cooling system according to a second embodiment of the present invention;
FIG. 7A is an enlarged side view showing a heat exchanger used in the liquid circulation type cooling system according to the second embodiment of the present invention;
FIG. 7B is an enlarged front view showing the heat exchanger of FIG. 7A;
FIG. 8 is a schematic diagram showing a circuit of the liquid circulation type cooling system according to the second embodiment of the present invention which is positioned upside-down;
FIG. 9A is an enlarged side view showing a heat exchanger used in the liquid circulation type cooling system according to the third embodiment of the present invention; and
FIG. 9B is an enlarged plan view showing the heat exchanger of FIG. 9A

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described in detail hereinafter by referring to the accompanying drawings.

First Embodiment

FIG. 3 is a schematic diagram showing a circuit of a liquid circulation type cooling system according to a first embodiment of the present invention wherein the liquid circulation type cooling system 10 includes a circulating pump 11 for circulating a liquid such as water, a heat exchanger 12 for radiating heat outside a casing for the system, the heat exchanger being disposed in a heat radiation space, a heat-receiving member 13 attached to an element to be cooled such as a heat-generating element, the heat-receiving member being served for transferring efficiently heat from the element to be cooled to the liquid, a piping 14 for connecting the above-mentioned components with each other, the piping being composed of a flexible tube or a fixed piping, and a fan 15 for supplying air to the heat exchanger 12 to achieve forced-air cooling.
The heat exchanger 12 has a core unit 18, a liquid reservoir 16 formed at the top of the core unit 18 in the vertical direction in the drawing, and another liquid reservoir 17 formed at the bottom of the core unit 18 in the drawing. The core unit 18, and the liquid reservoirs 16 and 17 are incorporated into one member. The liquid reservoir 16 contains inside the tank a space of the same capacity as that of the liquid reservoir 17, and vice versa. The whole space inside the liquid reservoir 17 is filled with a liquid, while the liquid reservoir 16 contains a liquid layer 16A and an air layer 16B.
FIG. 4A is an enlarged side view showing the heat exchanger 12, and FIG. 4B is an enlarged front view showing the heat exchanger 12 wherein the heat exchanger 12 is the one having a “corrugated straight fin core” type structure, which is composed of a core unit 18, a liquid reservoir 16 positioned at the top of the core unit 18 in the drawing, and the other liquid reservoir 17 positioned at the bottom of the core unit 18.
The core unit 18 is in a “corrugated straight fin core” which is obtained by incorporation of frill-shaped fins 121 made from a metal such as aluminum excellent in heat radiation with flat tubes 122 made from a metal such as aluminum by means of brazing.
Furthermore, in a heat exchanger of “corrugated straight fin core” type structure, both upper and lower headers are used for serving the liquid reservoirs 16 and 17 each of which is formed into a size having a capacity required for functioning as a liquid reservoir.
The liquid reservoir 16 has inside the tank a space of the same capacity as that of the liquid reservoir 17, and vice versa. Furthermore, a liquid opening 123 into and from which a liquid may be introduced and discharged is provided on the bottom side of the liquid reservoir 16, while a same liquid opening 124 is also provided on the upper side of the liquid reservoir 17. The liquid opening 123 may be connected to the liquid opening 124 through the piping 14 shown in FIG. 3.
Moreover, the liquid reservoir 16 is provided with an injection/degasification nozzle 125 on a side thereof, the injection/degasification nozzle 125 being served for injecting a liquid into the liquid reservoir and regulating a pressure of air in the liquid reservoir 16.
An internal capacity of the liquid reservoir 16 and that of the liquid reservoir 17 are decided on the basis of a volume of the whole system, an amount of air for adjusting an amount of increasing internal pressure accompanied with an increasing volume in case of rising a liquid temperature, and a losing amount of a liquid component (a permeation amount of a liquid) in the whole system. It is to be noted that the injection/degasification nozzle 125 is closed except for the case where a liquid is injected.
In the following, operations of the liquid circulation type cooling system 10 will be described by referring to FIGS. 3, 4A, and 4B.
In FIG. 3, first, when the liquid circulating pump 11 is driven, a liquid filled in a liquid circulation system is forcibly delivered. The heat-receiving member 13 is served for transferring heat conducted thermally from a heat-generating element being an element to be cooled to the liquid. Then, the liquid is forcibly delivered to the heat exchanger 12 through the piping 14. As shown in FIG. 4A, when the liquid is introduced from the liquid opening 123 provided on the liquid reservoir 16 in the heat exchanger 12, the liquid passes through the core unit 18 from the liquid reservoir 16. In the core unit 18, heat is radiated from the fins 121 incorporated with the tubes 122 in the case where the liquid passes through the tubes 122 as shown in FIG. 4B. Air is introduced into the heat exchanger 12 by means of the fan 15 (see FIG. 3) to promote heat radiation in the fins 121.
On one hand, the liquid transferred to the liquid reservoir 17 goes out from the liquid opening 124, and is transferred to the liquid circulating pump 11 through the piping 14 (see FIG. 3). In such a series of flow, an internal pressure increases in the liquid circulation system due to a temperature rise in the case when the liquid receives a heat from the element to be cooled. In such a case, however, an amount of increasing pressure is absorbed by an air layer 16B in the liquid reservoir 16 as a bumper.
Then, operations of the liquid circulation type cooling system 10 in the case where the cooling system is positioned upside-down are described by referring to FIG. 5.
FIG. 5 is a schematic diagram showing a circuit of the liquid circulation type cooling system 10 according to the first embodiment of the present invention in the case where it is positioned in the upside-down posture. In this situation, when the liquid circulating pump 11 is driven, the liquid filled in the liquid circulation system is forcibly delivered in the directions indicated by the arrows, and heat derived from a heat-generating element being an element to be cooled is conducted thermally to the liquid in the heat-receiving member 13. The liquid is forcibly delivered to the liquid reservoir 16 in the heat exchanger 12 through the piping 14, the heat is radiated from the liquid, when the liquid passes through the core unit 18, and then, the liquid is transferred to the liquid circulating pump 11 from the liquid reservoir 17.
As mentioned above, in FIG. 5, the liquid reservoir 17 is positioned at the head of the core unit 18, and the liquid is introduced to the circulating pump 11 from the core unit 18 through the liquid reservoir 17. In this situation, an air layer 17B resides over a liquid layer 17A in the liquid reservoir 17. In this respect, since a discharge port (the liquid opening 124 in FIGS. 4A and 4B) for liquid is filled with the liquid, no air flows into the piping 14 in the case when the liquid flows into the piping 14 in the downstream side of the liquid reservoir 17. Accordingly, air does not put in the liquid in the piping 14, even if the liquid circulation type cooling system 10 is positioned upside-down, so that decrease in a flow rate, stoppage of a pump and the like due to decrease in circulation of liquid can be prevented.
According to the liquid circulation type cooling system 10 of the above-mentioned first embodiment, the following advantageous effects can be obtained.
(1) The liquid opening 123 is provided on the side to which the core unit 18 is connected in the liquid reservoir 16, while the liquid opening 124 is provided on the side to which the core unit 18 is connected in the liquid reservoir 17. In this situation, even when an electronic instrument on which the liquid circulation type cooling system is mounted is positioned in the upside-down postures, the liquid openings 123 and 124 are always filled with a liquid, so that no air enters in the liquid in the piping 14. Thus, decrease in a flow rate, stoppage of a pump and the like due to decrease in circulation of liquid can be prevented.
(2) A heat exchanger having a “corrugated straight fine core” type structure is used for the heat exchanger of the invention, so that the upper and lower header sections of which are served for liquid reservoirs, respectively. Accordingly, the tubes 122 are always filled with a coolant, even if a plurality of liquid reservoirs is not disposed in an individual opposed part. For this reason, a structure of a liquid circulation circuit can be simplified, whereby increase in parts to be provided and increase in a space for mounting a liquid circulation type cooling system can be suppressed, and thus, downsizing and cost reduction of electronic instruments can be realized while ensuring good heat radiation.
(3) Since the air layer 16B resides in the liquid reservoir 16 or the air layer 17B resides in the liquid reservoir 17 for canceling an increasing amount of pressure in the liquid circulation system, increase in pressure derived from temperature changes of a liquid contained in the liquid circulation system can be absorbed.

Second Embodiment

FIG. 6 is a schematic diagram showing a circuit of a liquid circulation type cooling system according to a second embodiment of the present invention wherein the liquid circulation type cooling system 20 includes a circulating pump 21, for circulating a liquid, a heat exchanger 22 for radiating heat outside a casing for the system, the heat exchanger being disposed in a heat radiation space, a heat-receiving member 23 attached to an element to be cooled such as a heat-generating element, the heat-receiving member being served for transferring efficiently heat from the element to be cooled to the liquid, a piping 24 for connecting the above-mentioned components with each other, the piping being composed of a flexible tube or a fixed piping, and a fan 25 for supplying wind to the heat exchanger 22 to achieve forced-air cooling.
The heat exchanger 22 has a core unit 18, a liquid reservoir 26 formed on the left side with respect to the core unit 18 in the drawing, and another liquid reservoir 27 formed on the right side to the core unit 18 in the drawing. The core unit 18, and the liquid reservoirs 26 and 27 are incorporated into one member. The liquid reservoir 26 contains inside the tank a space of the same capacity as that of the liquid reservoir 27, and vice versa. The liquid reservoir 26 contains a liquid layer 26A and an air layer 26B, while the liquid reservoir 27 contains a liquid layer 27A and an air layer 27B.
FIG. 7A is an enlarged side view showing the heat exchanger 22, and FIG. 7B is an enlarged plan view showing the heat exchanger 22 wherein the heat exchanger 22 is the one having a “corrugated straight fin core” type structure, which is composed of a core unit 18, a liquid reservoir 26 positioned on the left side to the core unit 18 in the drawing, and the other liquid reservoir 27 positioned on the right side to the core unit 18.
The core unit 18 is the one formed by the same manner as that of the liquid circulation type cooling system 10 in the first embodiment.
The liquid reservoir 26 has inside the tank a space of the same capacity as that of the liquid reservoir 27, and vice versa. Furthermore, a liquid opening 223 into and from which a liquid may be introduced and discharged is provided on the liquid reservoir 26 on the right side of the core unit 18, while a same liquid opening 224 is provided on the liquid reservoir 27 on the left side of the core unit 18. The liquid opening 223 may be connected to the liquid opening 224 through the piping 24 shown in FIG. 6.
Moreover, the liquid reservoir 26 is provided with an injection/degasification nozzle 225 on a side thereof, the injection/degasification nozzle 225 being served for injecting a liquid into the liquid reservoir 26 and regulating a pressure of air in the liquid reservoir 26.
In the following, operations of the liquid circulation type cooling system 20 will be described by referring to FIG. 6 and FIGS. 7A, 7B.
In FIG. 6, first, when the liquid circulating pump 21 is driven, a liquid filled in the liquid circulation system is forcibly delivered. The heat-receiving member 23 is served for transferring heat conducted thermally from a heat-generating element being an element to be cooled to the liquid. Then, the liquid is forcibly delivered to the heat exchanger 22 through the piping 14. As shown in FIG. 7A, when the liquid is introduced from the liquid opening 224 provided on the liquid reservoir 27 in the heat exchanger 22, the liquid passes through the core unit 18 from the liquid reservoir 27. In the core unit 18, heat is radiated from the fins 121 incorporated with the tubes 122, when the liquid passes through the tubes 122 as shown in FIG. 7B. Air is introduced into the heat exchanger 22 by means of the fan 25 (see FIG. 6) to promote heat radiation in the fins 121.
On one hand, the liquid transferred to the liquid reservoir 26 goes out from the liquid opening 223, and is transferred to the liquid circulating pump 21 through the piping 24 (see FIG. 6).
Then, operations of the liquid circulation type cooling system 20 in the case where the cooling system is positioned in the upside-down posture are described by referring to FIG. 8.
FIG. 8 is a schematic diagram showing a circuit of the liquid circulation type cooling system 20 according to the second embodiment of the present invention in the case where it is positioned upside-down. In this situation, when the liquid circulating pump 21 is driven, the liquid filled in the liquid circulation system is forcibly delivered in the directions indicated by the arrows, and heat derived from a heat-generating element being an element to be cooled is conducted thermally to the liquid in the heat-receiving member 23. The liquid is forcibly delivered to the liquid reservoir 27 in the heat exchanger 22 through the piping 24, the heat is radiated from the liquid, when the liquid passes through the core unit 18, and then, the liquid is transferred to the liquid circulating pump 21 from the liquid reservoir 26.
As mentioned above, the liquid is introduced to the circulating pump 21 from the core unit 18 through the liquid reservoir 26 in FIG. 8. In this situation, an air layer 26C resides over the liquid layer 26A in the liquid reservoir 26. In this respect, since a discharge port (the liquid opening 223 in FIGS. 7A and 7B) for liquid is filled with the liquid, no air flows into the piping 24 in the case when the liquid flows into the piping 24 in the downstream side of the liquid reservoir 26. Accordingly, air does not put in the liquid in the piping 24, even if the liquid circulation type cooling system 20 is positioned upside-down, so that decrease in a flow rate, stoppage of a pump and the like due to decrease in circulation of liquid can be prevented.
According to the above-mentioned liquid circulation type cooling system 20 of the second embodiment, the same advantageous effects as that of the liquid circulation type cooling system 10 of the first embodiment can be obtained.

Third Embodiment

FIG. 9A is a side view showing a structure of a heat exchanger 32 used in a liquid circulation type cooling system according to a third embodiment of the present invention, and FIG. 9B is a plan view showing the heat exchanger 32 wherein the heat exchanger 32 is the one having a “corrugated straight fin core” type structure, which is composed of a core unit 18, a liquid reservoir 36 positioned on the left side to the core unit 18 in the drawing, and another liquid reservoir 37 positioned on the right side to the core unit 18.
The heat exchanger 32 has the same structure as that of the heat exchanger 22 except that the liquid reservoir 36 has a liquid opening 323 into and from which a liquid may be introduced and discharged on a side of the liquid reservoir 36 perpendicular to the side to which the core unit 18 is connected, while a liquid opening 324 which is the same as the liquid opening 323 is provided on a side of the liquid reservoir 37 perpendicular to the side to which the core unit 18 is connected wherein the side of the liquid opening 324 is in a direction opposite to the liquid opening 323, and the liquid reservoir 36 is provided with an injection/degasification nozzle 325 on the top side thereof. The injection/degasification nozzle 325 is served for injecting a liquid into the liquid reservoir and regulating a pressure of air in the liquid reservoir 36.
When the heat exchanger 32 is used in place of the heat exchanger 22 in the liquid circulation type cooling system 20 shown in FIG. 6, the same advantageous effects as that of the liquid circulation type cooling system 20 according to the second embodiment can be achieved in the present embodiment.
While a heat exchanger contains two liquid reservoirs in the above-described embodiments, the heat exchanger may contain three or more liquid reservoirs. Furthermore, although a structure wherein a core unit 18 is formed into a single layer with respect to a direction along which air passes through has been described, two or more layers may be applied in response to an amount of heat radiation. Moreover, liquid reservoirs for a coolant have not been separately disposed in a liquid circulation system, but such liquid reservoirs may be individually disposed in a liquid circulation system.
In addition, it may be arranged in such that when a coolant in a liquid reservoir decreases, an alarm signal is given by attaching a liquid level sensor to the liquid reservoir.
It will be appreciated by those of ordinary skill in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof.
The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.

Claims

1. A liquid circulation type cooling system, comprising:

a member for receiving heat from a heat-generating element such as a semiconductor element;

a reservoir for containing liquid to transfer heat;

a radiator for radiating heat which is transferred through the liquid from the member; and

a system for circulating the liquid among the reservoir, the radiator and the member,

wherein the radiator comprises a heat exchanger and a fan for forcibly supplying air to the heat exchanger.

2. The liquid circulation type cooling system as defined in claim 1, wherein:

the reservoir functions as a header for supplying the liquid to a core unit of the heat exchanger.

3. The liquid circulation type cooling system as defined in claim 1, wherein:

the cooling system operates even in the upside-down installation posture.

4. A liquid circulation type cooling system, comprising:

a heat radiation space for radiating heat of liquid heated by a heat-generating element; and

a system for circulating the liquid through the heat radiation space;

the heat radiation space comprising a first liquid reservoir on a first side thereof; a second liquid reservoir on a second side thereof to be in series with the first liquid reservoir; the first and second liquid reservoir being vertically arranged at different levels; and liquid openings provided on the first and second liquid reservoirs to be connected to the-liquid-circulating system;

wherein the liquid opening of the first liquid reservoir is filled with the liquid, even if the first liquid reservoir is positioned at an upper place than that of the second liquid reservoir, while the liquid opening of the second liquid reservoir is filled with the liquid, even if the second liquid reservoir is positioned at the upper place than that of the first liquid reservoir.

5. The liquid circulation type cooling system as defined in claim 4, wherein:

the heat radiation space comprises a core unit provided between the first and second liquid reservoirs to be connected therethrough, thereby providing a heat exchanger.

6. A liquid circulation type cooling system, comprising:

a system for circulating the liquid through the heat radiation space;

the heat radiation space comprising a first liquid reservoir on a first side thereof; a second liquid reservoir on a second side thereof to be in series with the first liquid reservoir; the first and second liquid reservoirs being horizontally arranged at the same level; and liquid openings provided on the first and second liquid reservoirs to be connected to the liquid-circulating system;

wherein the liquid openings of the first and second liquid reservoirs are filled with the liquid, even if the cooling system is installed in the upside-down postures.

7. The liquid circulation type cooling system as defined in claim 6, wherein:

8. The liquid circulation type cooling system as defined in claim 5, wherein:

the heat exchanger has “corrugated straight fin core” type structure which comprises tubes, fins, and headers, the headers being served for the liquid reservoirs.

9. The liquid circulation type cooling system as defined in claim 7, wherein:

10. The liquid circulation type cooling system as defined in claim 5, wherein:

a fan for supplying air to forcibly cool the heat exchanger is disposed outside the heat exchanger.

11. The liquid circulation type cooling system as defined in claim 7, wherein:

12. The liquid circulation type cooling system as defined in claim 4, wherein:

the liquid reservoir is provided with a liquid level sensor for generating a warning signal in case of shortage of the liquid.

13. The liquid circulation type cooling system as defined in claim 6, wherein: