TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of cooling hot electronic components, such as Central Processing Units (CPU), Graphical Processing Units (GPU) and the like. More particuialy, the present invention relates to a cooling system for cooling such components.

DESCRIPTION OF RELATED ART

In computers and other electronic equipment the electronic components such as CPUs and GPUs have become more and more powerful and thus generate more heat. Traditionally a CPU and the like is provided with or connected to heat radiating fins that are used to cool the CPU by dissipating the heat there from. The heat generated by the CPU spreads from the contact surface of the CPU to the radiating fins, which are cooled by the ambient air. However, the heat capacity of such fins is limited and therefore usually a fan is provided to increase the airflow through the fins.

The problem with fans is that they are noisy, consume energy and tend to wear out with time. In a computing center, which is a room full of computers, servers and the like, the hot air disposed by the fans is mixed w.i th the air in the room in which the computers are placed. Large air-condition equipment is required to keep the temperature in that room at an acceptable level. The amount of energy needed to power the air-conditioning equipment is about the same as the amount of energy needed Lo operate the "useful" electronic components. Since this energy, in form of heated air, is mixed with the ambient air in the room it is very difficult to recuperate this energy. Furthermore, the noise in computing centers is very loud. This is not a big problem, since there seldom are any people working in such rooms. However, it would be nice if one was able to lower the noise for the people that have to visit the computing centre. Thus, as mentioned above the main problem with computing centers is all the energy that is needed to cool the room and all the energy in form of hot air in the room that is wasted.

U.S. patent 6,639,797 describes a cooling device that uses heat transport pipes and a liquid cooling system such that the cooling can take place remote from were the heat is generated. The purpose of the invention is to create a compact cooling system that does not take up a lot of space in a computer.

U.S. patent 7,392,836 describes a heat spreader containing a cycled two-phase vaporizable coolant. The coolant cycles inside a closed metal chamber, which also contains a wick layer that serves as an evaporator. The liquid coolant is vaporized by the heat from the heat-generating device and condenses on channel walls. The condensed coolant is collected by the wick and flows back to the wick evaporator by capillary action, thereby cycling the coolant.

Thus, there is a need for a cooling device or system that is energy efficient and preferably also silent. SUMMARY OF THE INVENTION

The present invention is directed towards creating a cooling system that is both quiet and more energy efficient compared to the cooling devices or systems that are in use today for cooling computer centers. It is furthermore desired to create a cooling system that is simple in its structure, having few parts and will be easy to install.

According to one aspect of the present invention there is provided a cooling system for cooling hot electronic components m a cooling center, which comprises a heat receiving structure having one end in direct contact with the electronic component for conducting the heat from said electronic component and having another end m direct contact with a confined cooling channe] adapted for receiving said heat and having a flow there through, wherein the confined cooling channel (8} comprises an inlet side (20) and an outlet side (18), which are connected to the outside of the computing center.

According to another aspect of the inventj on the heat receiving structure comprises an outer layer of thermal Iy isolating material for thermally isolating the heat receiving structure from the ambient air in the computing center.

According to a third aspect of the invention the heat receiving structure is solid and made of a material having high heat conductivity.

According to a forth aspect of the invention the heat receiving structure comprises heat pipes .

According to a fifth aspect of the invention there is provided at least one cooling structure inside of the cooling channel.

According to a sixth aspect of the invention the at least one cooling structure is provided spaced apart from the cooling channel walls by means of one or more spacers.

According to a seventh aspect of the invention the cooling cannel is provided in such a way that the flow there through is substantially vertical.

According to an eighth aspect of the invention at least one fan is provided to increase the flow through the cooling channel .

According to a ninth aspect of the invention the cooling channel comprises an outer layer of a thermaLly isolating material for thermally isolating it from the ambient air Ln the computing center.

According to a tenth aspect of the invention the flow inside the cooling channel consists of a gas such as air.

According to an eleventh aspect of the invention the flow inside of the cool ing channel consists of a fluid such as water .

Thus, the present invention reduces the need for air- conditioning. Furthermore, it will be easier Lo recuperate the energy produced by the electronic components, and thus substantial financial savings will be achieved.

Apart from the drastic reduction of air-conditioning also a reduction in noise will be achieved. Thus makes it possible to place units with large amount of electronic components in office environments, something which is not possible with the traditional way of cooling.

Tt should be noted that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The present invention will now be described .in more detail in relation to the enclosed drawings, in which:

Figure 1 schematically shows a side view of cooling system for cooling just one hot electronic component.

Figure 2 schematically shows a cross section of the cooling system in figure 1.

Figure 3 shows a cooling system having several internal cooling structures .

Figure 4 shows a cooling structure adapted for cooling several computes, typically for use in a computing center. DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows a side view of a cooling system for cooling one or a few hot components. In figure 1 reference numeral 2 denotes a hot electronic component such as a CPU or the like. In this embodiment the CPU 2 is provided on a regular main board 4. However, it should be understood that it does not necessarily have to be a CPU 2 that is to be cooled, but could be any hot electronic component 2 that needs to be cooled off.

As can be seen in figure 1, a heat receiving structure 6 is in contact with the CPU 2 for conducting the heat from said CPU 2. The other end of the heat receiving structure 6 is in direct contact with a confined cooling channel 8 having an inlet side 20 and an outlet side 18 (see figure 4) . The cooling channel 8 is adapted for receiving the heat. Thus, the purpose of the heat receiving structure 6 is to collect the excess heat of the hot electronic component 2 and transmit it to the cooling channel 8. By a confined cooling channel 8 is meant that the oniy openings that are provided in the channe L 8 are the inlet 20 and the outlet 18.

The heat receiving structure 6 may be solid and made of a material having high heat conductivity, such as copper or aluminum. In another embodiment the heat receiving structure 6 might consist of heat pipes, which work according to the principles described above in conjunction with U.S. patent 7,392,836, and is therefore not described in any more detail

In the embodiment of the present invention shown in figure 1 the cooling channel 8 comprises the channel 8 itself and an internal cooling structure 12, which in this case will result m two channels.

The internal cooling structure 12 is not necessary for carrying out the present invention. However, the use of the internal cooling structure 12 will increase the cooling capacity of the cooling system, since the cooling channel will be able to conduct more heat. The shape of the cooling channel 8 is m a preferred embodiment of the present invention defined by rectangular plates, which define the width and Lhe height of the channel 8, The depth of the channel 8 is defined by spacers 14 that separate the walls of the cooJ ing channel 8 and, when applicable, also the internal cooling structures 12 from the walls.

In figure 2 the cooling channel 8 is augmented with one j nternal cooling structure 12, which exhibits the same dimensions as the walls of the cooling channel 8. Thus, in this case the cooling channel 8 consists of three plates that arc separated by six spacers 14. The djmensions of the internal cooling structures 8 may vary depending on the cooling requirements and might be both smaller and larger. Also the number of internal cooling structures may vary depending on the cooling need. They might be placed along the whole cooling channel 8 or just be covering a part of the cooling channel 8. Figure 3 shows a side view of a cooling channel 8 having three internal cooling structures I?.

Jn a preferred embodiment of the present invention the heat receiving structure 6 is covered with a layer of thermal isolation. The Layer of thermal isolation is used to reduce the amount of heat dissipated from the heat receiving structure 6 to the ambient air and thus facilitates the transport of excess heat from the hot electronic component 2 to the cooling channel 8.

In another preferred embodiment of the present invention the cooling channel 8 is vertically oriented in order to let the gravity facilitate the flow through the cooling channel and thereby increase the cooling capacity of the cooling system.

The walls of the cooling channel 8, and if applicable the internal cooling structures 12, are preferably made of a material having high heat conductivity. Furthermore, it is preferred that the outer walls of the cooling channel 8 are covered with a layer of thermal isolation. Firstly, this will help to retain as much as possible of the generated heat inside the cooling channel 8. The benefit thereof is that it substantially will reduce the need for air-conditioning in the room of the equipment, since the outlet 18 and also the inlet 20, is connected to the outside of the room, i.e. outside the room of the computing center. Secondly, it will also make it easier, and more efficient, to recuperate the energy contained in the generated heat, for example by connecting a heat exchanger to bhe outlet 18. Thirdly, it will reduce the temperature on the side of the cooling channel 8 that is in contact with the hot component. This is an advantage if the main board 4 comprises other components that are heat sensitive. Fourthly, the thermal isolation also secures that as much as possible of the heat is conducted to the inside of the cooling channel 8, which increase the cooling efficiency and lowers the temperature of the hot components. These four aspects are all important for achieving the benefits mentioned above regarding the cooling of large amounts of hot electronic components, either placed m a computer center or m an office environment.

The hot boundary layer oi the walls of the cooling channel 8 will increase its thickness along the height of the cooling system. This will make the cooling less efficient towards the top of the channel. By providing internal cooling structures 12 distributed along the cooling channel 8 is it possible for the cooling channel 8 to transport away more heat. Figure 3 shows an example of how the internal cooling structures may be distributed along the cooling channel 8. [t is within the ability of a skilled person to adapt the number and size of internal cooling structures 12 to create a cooling system having the desired cooling capacity. For example, the internal cooling structures 12 might have rounded edges m order to facilitate the flow through the channel. Thus, it should be clear that the important thing is to create an even flow along all the cooling structures throughout the cooling channel in order to obtain an efficient cooling.

Lven if the cooling system according to the present invention is very efficient in conducLing heat wi Lhout the use of a fan, it might arise situations m which such a large number of hot electronic components need to be cooled, that it is necessary to increase the flow through the cooling channel 8 by means of one or several fans, depending on the cooling requirements. Such a situation wi 1 L be described now.

In figure 4 a cooling system is shown. For the sake of simplicity reference numeral 16 is used Lo denote both the CPU 2 and the heat receiving structure in figure 4, which components are shown Ln detail in figure 1. As is evident Ϊ O

from figure 4 there are 16 hot electronic components to be cooled. Each hot electronic component is arranged in direct contact with the heat receiving structure as is shown in figure 1. All 16 heat receiving structures are in direct contact with one and the same cooling channel 8.

The cooling channel 8 has an inlet side and an outlet side, thereby separating the air in the cooling channel 8 from the ambient air in the computing center. At least one fan 22 is connected to the inlet side 20 of the cooling channel 8 to create a flow through the cooling channel 8 and thereby increase the cooling capacity. It should be noted that it also is possible to arrange a fan 22 on the outlet side 18 of the cooling channel 8 to create a suction flow through the cooling channel 8. As is evident for a person skilled in the art there are a lot of possibilities to arrange a fan or fans in order to create a flow from the inlet 20 to the outlet 18 of the cooling channel 8.

Thus, compared to the traditional way of cooling a computing centre, where the air in the room is air-conditioned, the present invention separates the heated flow in the cool ing channel from the ambient air and preferably leads it out of the computing center room. By doing this the energy from the hot electronic components is to a large extent prevented from being mixed with the ambient air in the computing center room, and it is this feature of the invention that dramatically reduces the need for air-conditioning.

In a preferred embodiment of the present invention the hot flow that is lead to the outside of the computing center room is heat exchanged for recovering energy. This will lead to major energy savings compared with today. In another preferred embodiment of the invention, the outside walls of the cooling channel 8 are covered with a layer of thermal isolation .

It should be understood that the flow through the cooling channel 8 might consist of either a gas, such as air or of a fluid such as water. Tt lies within the ability of a skilled person to design the cooling system either for gas or fluid or both.

Thus, a novel cooling system has been described, which will be both energy efficient and very quiet compared with today's solutions. Furthermore, this cooling system will not only save energy traditionally used for cooling for example a computing centre, but it will also facilitate the recovery of the energy conducted from the hot electronic components.