JP5772315B2 - Electronic equipment cooling system - Google Patents

Description

  The present invention relates to a cooling system for electronic equipment.

  In recent years, with the advent of an advanced information society, the amount of data handled by computers has become enormous, and data maintenance has become increasingly important. For this reason, many racks (server racks) are installed in the same room in a facility such as a data center, and a plurality of computers (servers) are housed in each rack to collectively manage the computers.

  Under such circumstances, a large amount of heat is generated from the computer, causing malfunctions and failures. Therefore, it is important to sufficiently cool the computer. For this reason, in a normal data center, heat generated by a computer is discharged out of the rack by a fan (blower), and the indoor temperature is adjusted by using an air conditioner (air conditioner).

  By the way, in the data center, it is said that a large amount of power is consumed by the air conditioning equipment, which is comparable to the total power consumed by all computers. In order to reduce the power consumed in the data center, it has been proposed to introduce the outside air indoors when the temperature of the outside air is low.

JP 2010-232689 A Japanese Patent Laid-Open No. 10-206046 JP 2009-257730 A

Japan Heat Pipe Association, “Practical Heat Pipe, Second Edition”, Nikkan Kogyo Shimbun (2001), p38-39

  It is an object of the present invention to provide a cooling system that can efficiently cool an electronic device installed indoors using outside air, and can avoid occurrence of problems due to changes in indoor humidity and dust.

According to one aspect of the disclosed technology, a first area in which an electronic device is installed, a second area that is disposed adjacent to the first area and into which outside air is introduced, and the second area A third area that is disposed adjacent to the outside area, the first area separating the first area and the second area, the second area, and the third area. A second separation wall disposed between the first separation wall and an opening that communicates the second area and the third area; and through the first separation wall; There is provided an electronic device cooling system including a heat transport member for transporting generated heat to the second area.

  According to the electronic device cooling system of the above aspect, the electronic device installed in the first area can be efficiently cooled using outside air, and the humidity change in the first area and problems caused by dust Can be avoided.

FIG. 1 is a schematic diagram illustrating a cooling system for an electronic device according to an embodiment. FIG. 2 is a schematic diagram showing a system board stored in the rack. FIG. 3 is a diagram showing a result of simulating the flow of air flowing from the second cooling chamber to the first cooling chamber. FIG. 4 is a diagram showing the relationship between the angle of the heat pipe and the maximum heat transport amount. FIG. 5 is a diagram illustrating an example of a method of changing the opening area of the opening. 6A and 6B are diagrams showing another example of a method for changing the opening area of the opening. FIG. 7 is a diagram showing the relationship between the air volume and the static pressure when the voltage supplied to the fan (blower) is constant. FIG. 8 is a schematic diagram illustrating an example in which a wind speed sensor and a temperature sensor are installed in the first cooling chamber to control the rotational speed of the fan.

  As described above, in order to reduce power used for air conditioning in facilities such as a data center, it has been proposed to introduce outside air into the room when the temperature of the outside air is low.

  However, if the outside air is introduced into the room as it is, the humidity in the room changes greatly, and a problem may occur in the computer due to static electricity or condensation. In addition, dust may be introduced into the room and cause a failure of the computer.

  Therefore, in the following embodiments, a cooling system is disclosed that can efficiently cool an electronic device installed indoors by using outside air, and can avoid occurrence of problems due to changes in indoor humidity and dust.

(Embodiment)
FIG. 1 is a schematic diagram illustrating a cooling system for an electronic device according to an embodiment.

  As shown in FIG. 1, the computer room 10 is separated into an equipment installation area 21, a first cooling room 22, and a second cooling room 23 by separation walls 25 and 26. The device installation area 21 is an example of a first area, the first cooling chamber 22 is an example of a second area, and the second cooling chamber 23 is an example of a third area.

  In the device installation area 21, a rack 12 storing a plurality of system boards (computers) 13 is arranged. The rack 12 is provided with a fan (not shown) that introduces air from the air supply surface side (left side in FIG. 1) of the rack 12 and discharges air from the exhaust surface side (right side in FIG. 1).

  Although only one rack 12 is shown in FIG. 1, a large number of racks 12 are installed in the device installation area 21.

  A cold air flow path 31 is provided below the floor of the device installation area 21. Air (cold air) whose temperature and humidity are adjusted is supplied to the cold air passage 31 from a cold air supply port provided in the lower part of the air conditioner 11. The floor of the equipment installation area 21 is provided with a grill (ventilation opening) 35 that communicates between the equipment installation area 21 and the cold air passage 31. The rack 12 supplies the rack 12 through the grill 35. Cold air is supplied to the air side.

  On the other hand, a hot air flow path 32 is provided above the equipment installation area 21 (behind the ceiling), and an opening that communicates between the equipment installation area 21 and the hot air flow path 32 is provided on the ceiling on the exhaust surface side of the rack 12. A portion 32a is provided. On the exhaust surface side of the rack 12, air (hot air) whose temperature has been increased by cooling the system board 13 is discharged. The air discharged from the rack 12 enters the warm air channel 32 through the opening 32a, and is transferred to the air intake at the top of the air conditioner 11 through the warm air channel 32.

  In this embodiment, the area on the rack air supply surface side to which low-temperature air is supplied and the area on the rack exhaust surface side from which the air whose temperature has risen through the rack 12 is discharged are divided into partitions 24a and 24b. It is separated by. However, these partitions 24a and 24b are not essential, and may be installed as necessary. Hereinafter, the area on the rack air supply surface side to which low-temperature air is supplied is referred to as cold aisle, and the area on the rack exhaust surface side where air whose temperature has risen through the rack 12 is discharged is referred to as hot aisle.

  The first cooling chamber 22 is disposed adjacent to the device installation area 21, and a separation wall 25 is provided between the first cooling chamber 22 and the device installation area 21. The second cooling chamber 23 is disposed adjacent to the first cooling chamber 22, and a separation wall 26 is provided between the first cooling chamber 22 and the second cooling chamber 23.

  Under the floors of the first cooling chamber 22 and the second cooling chamber 23, an outside air introduction path 33 that communicates with the outdoors is provided. A grill 36 is disposed between the first cooling chamber 22 and the outside air introduction path 33, and a grill 37 is disposed between the second cooling chamber 23 and the outside air introduction path 33. Outside air is introduced into the first cooling chamber 22 and the second cooling chamber 23 through the outside air introduction path 33 and the grills 36 and 37.

  On the other hand, on the first cooling chamber 22 and the second cooling chamber 23 (back of the ceiling), an outside air discharge path 34 that communicates with the outdoors is provided. A fan (blower) 38 is provided between the first cooling chamber 22 and the outside air discharge path 34, and the air in the first cooling chamber 22 is discharged outside through the outside air discharge path 34 by the rotation of the fan 38. Is done. The separation wall 26 between the first cooling chamber 22 and the second cooling chamber 23 is provided with a plurality of openings 26a arranged in the height direction, and the second cooling is performed via these openings 26a. Air (outside air) is supplied from the chamber 23 to the first cooling chamber 22.

  FIG. 2 is a schematic diagram showing the system board 13 accommodated in the rack 12. A CPU 41 and other electronic components are mounted on the system board 13, and a heat sink 42 and a heat pipe 15 are attached to the electronic components that generate a large amount of heat. The electronic component that generates a large amount of heat is thermally connected to the heat sink 42 and the heat pipe 15. In the present embodiment, it is assumed that the electronic component to which the heat sink 42 and the heat pipe 15 are attached is the CPU 41. The heat pipe 15 is an example of a heat transport member.

  A plurality of heat radiation fins 16 are provided on the front end side of the heat pipe 15 (the side opposite to the heat sink 42), and the front end portion of the heat pipe 15 is cooled by the air passing between the heat radiation fins 16.

  The heat pipe 15 is made by sealing water or alcohol or the like as a working fluid in a metal pipe having high thermal conductivity such as copper, and a porous material called wick adheres to the inner surface of the heat pipe 15. On the high temperature side of the heat pipe 15, the working fluid is changed from a liquid phase to a gas phase by absorbing heat transmitted from the heat sink 42. Since the volume of the working fluid increases with the change from the liquid phase to the gas phase, the pressure increases on the high temperature side of the heat pipe 15. On the other hand, on the low temperature side of the heat pipe 15, the gas-phase working fluid is changed to a liquid phase by being cooled by air passing between the radiation fins 16. Since the volume of the working fluid decreases with the change from the gas phase to the liquid phase, the pressure decreases on the low temperature side.

  As described above, since a pressure difference is generated between the high temperature side and the low temperature side in the heat pipe 15, the working fluid that has changed into a gas phase on the high temperature side moves to the low temperature side. In addition, the working fluid that has changed to the liquid phase on the low temperature side moves to the high temperature side due to gravity or the capillary force of the wick.

  The heat pipe 15 transports heat from the high temperature side (heat sink side) to the low temperature side (radiation fin side) using such a change between the gas phase and the liquid phase of the working fluid. The heat transport efficiency of the heat pipe 15 increases as the temperature difference between the high temperature side and the low temperature side increases.

  In the present embodiment, as shown in FIG. 1, the heat pipe 15 is led out of the rack 12, and the tip portion thereof is disposed in the first cooling chamber 22 through a hole provided in the separation wall 26. Yes. A packing member 25 a is disposed in the hole provided in the separation wall 26 to prevent air leakage between the device installation area 21 and the first cooling chamber 22.

  Hereinafter, the operation of the electronic apparatus cooling system according to the above-described embodiment will be described.

  The air whose temperature and humidity are adjusted by the air conditioner 11 is supplied to the equipment installation area 21 (cold aisle) via the cold air flow path 31 and the grill 35. This air is taken into the rack 12 by a fan (not shown) provided in the rack 12 and cools the electronic components mounted on the system board 13. Then, the air whose temperature has risen by cooling the electronic components is discharged to the exhaust surface side (hot aisle) of the rack 12 and returns to the air conditioner 11 through the hot air flow path 32.

  On the other hand, the CPU 41 mounted on the system board 13 generates heat according to the operating state. Part of the heat generated by the CPU 41 is exchanged with the air passing through the rack 12 and discharged to the exhaust surface side (hot aisle) of the rack 12, but most of the heat is transferred to the heat pipe 15 via the heat sink 42. And transported to the front end side of the heat pipe 15. Then, the heat transported to the front end side of the heat pipe 15 is discharged into the first cooling chamber 22 through the radiation fins 16, and further discharged to the outdoors by outside air passing through the first cooling chamber 22.

  As described above, in the present embodiment, most of the heat generated by the CPU 41 is transported to the first cooling chamber 22 by the heat pipe 15 and discharged to the outdoors by the outside air passing through the first cooling chamber 22. Thereby, the amount of heat discharged from the rack 12 into the equipment installation area 21 is reduced, and the load on the air conditioner 11 is reduced. As a result, the power consumed by the air conditioner 11 is reduced. Further, since outside air is not introduced into the device installation area 21, it is possible to avoid a problem occurring in the system board 13 due to a change in humidity within the device installation area 21 and dust contained in the outside air.

  By the way, in this embodiment, the 2nd cooling chamber 23 is provided adjacent to the 1st cooling chamber 22, and external air is introduce | transduced into the 1st cooling chamber 22 from the 2nd cooling chamber 23 through the opening part 26a. If there is no second cooling chamber 23, each heat pipe 15 arranged in the first cooling chamber 22 is cooled by outside air flowing from the bottom to the top in the first cooling chamber 22. In this case, since the air heated by the lower heat pipe 15 is supplied to the heat pipe 15 arranged on the upper side, the heat transport efficiency is lowered as the heat pipe 15 is arranged on the upper side.

  On the other hand, in the present embodiment, the second cooling chamber 23 is provided next to the first cooling chamber 22 and is disposed above the first cooling chamber 22 through the opening 26a provided in the separation wall 26 therebetween. The low temperature outside air is also supplied to the heat pipe 15. Therefore, in this embodiment, the fall of the heat transport efficiency of the heat pipe 15 arrange | positioned at the upper side is avoided.

FIG. 3 is a diagram showing a result of simulating the flow of air flowing from the second cooling chamber 23 to the first cooling chamber 22. However, the flow rate of the air discharged from the upper part of the second cooling chamber 23 is set to 60 m ³ / min.

  As shown in FIG. 3, a certain distance in the height direction is required before the air introduced into the first cooling chamber 22 from the opening 26 a reaches the center of the first cooling chamber 22. When the width of the first cooling chamber 22 is d, and the distance in the height direction from the tip end portion (radiating fin 16) of the heat pipe 15 to the opening 26a is smaller than d / 2, the first cooling chamber 22 is set. It becomes impossible to sufficiently cool the tip of the heat pipe 15 arranged at the center of the heat pipe 15.

  On the other hand, if the distance in the height direction from the tip (radiating fin 16) of the heat pipe 15 to the opening 26a is greater than d, the distance between the heat pipes 15, in other words, the distance between the system boards 13 must be increased. There is. As a result, the number of system boards 13 that can be stored in the rack 12 is reduced.

  Therefore, it is preferable to arrange the opening 26a at a position spaced apart by d / 2 to d downward from the tip end portion (radiating fin 16) of the heat pipe 15.

  In addition, in this embodiment, since the space | interval of the heat pipe 15 arrange | positioned in the lowest stage and a floor surface is narrow, an opening part is set in the position which d / 2 away downward from the front-end | tip of the heat pipe 15 arrange | positioned in the lowest stage. Can not be provided. For this reason, in this embodiment, the lowermost heat pipe 15 is cooled by the air introduced from the grill 36 as shown in FIG.

  FIG. 4 is a diagram showing the relationship between the horizontal axis with the angle of the heat pipe 15 and the vertical axis with the maximum heat transport amount. The value on the vertical axis is a value obtained by normalizing the maximum heat transport efficiency at each angle with the maximum heat transport amount when the heat pipes are arranged vertically.

  From FIG. 4, it can be seen that the heat pipe can transport heat most efficiently when it is inclined by 50 ° to 60 ° with respect to the horizontal plane. Therefore, in the present embodiment, as shown in FIG. 2, the heat pipe 15 whose tip is curved at an angle of 50 degrees to 60 degrees with respect to the horizontal plane is used. Thereby, the heat pipe 15 can be used in a state with the highest heat transport efficiency.

  In this embodiment, when the heat pipe 15 arranged at the lowermost stage is curved, it is conceivable that the outside air rising from the grill 36 strikes the radiating fins 16 at an angle and the cooling efficiency is lowered. Therefore, as shown in FIG. 1, the lowermost heat pipe 15 is a straight one.

(Modification 1)
Since the temperature in the first cooling chamber 22 is considered to be higher as it goes upward, the opening area of the upper opening 26a may be increased. Further, the opening area of the opening 26 a may be changed according to the temperature of the tip portion of each heat pipe 15.

  FIG. 5 is a diagram illustrating an example of a method for changing the opening area of the opening 26a. In this example, a temperature sensor 51 is disposed at the tip of each heat pipe 15, and the temperature sensor 51 and the control unit 50 are connected. In addition, an electric shutter 52 is disposed in each opening 26 a of the separation wall 26 so that the electric shutter 52 can be individually driven by a signal from the control unit 50.

  When the temperature detected by the temperature sensor 51 is high, the control unit 50 drives the electric shutter 52 to increase the opening area of the opening 26a. When the temperature detected by the temperature sensor 51 is low, the control unit 50 drives the electric shutter 52 to reduce the opening area of the opening 26a. Thus, by adjusting the opening area of the opening 26a according to the temperature detected by the temperature sensor 51, each heat pipe 15 can be appropriately cooled.

  6A and 6B, a damper 53 and a louver 54 are attached to the opening 26a, and the angle of the damper 53 and the louver 54 is adjusted to change the opening area of the opening 26a. Also good.

  Further, instead of the temperature sensor 51 or together with the temperature sensor 51, an air volume sensor is attached to the tip of each heat pipe 15, and the opening area of the opening 26 a is adjusted by the electric shutter 52 or the like based on signals output from these sensors. You may adjust.

(Modification 2)
In the above-described embodiment, if the opening area of the opening 26a is changed while the rotation speed of the fan 38 is constant, it may be difficult to properly cool all the heat pipes 15. For example, if the opening area of the upper opening 26a is increased, the heat pipe 15 disposed on the lower side may have insufficient air volume and insufficient cooling. Conversely, when the opening area of the lower opening 26a is increased, the amount of outside air introduced into the first cooling chamber 22 from the upper opening 26a is reduced, and the heat pipe 15 disposed on the upper side is insufficiently cooled. May be.

  FIG. 7 is a graph showing the relationship between the air volume and static pressure when the voltage supplied to the fan (blower) is constant with the air volume on the horizontal axis and the static pressure on the vertical axis. Here, as schematically shown in FIG. 7, the relationship between the air volume and the static pressure in a box provided with a fan on one surface is shown. Here, the static pressure is the absolute value of the difference between the pressure in the box and the atmospheric pressure (static pressure = | pressure in the box−atmospheric pressure |).

  For example, when there is no opening other than the part where the fan is arranged, when the fan is rotated, air flows instantaneously by the fan, but the amount of air passing through the fan (air volume) becomes 0 after a certain period of time. Become. At this time, the static pressure in the box is maximized.

  If an opening is provided on a surface other than the surface where the fan is disposed, the amount of air passing through the fan increases according to the area of the opening, and the static pressure in the box decreases. If the rotational speed of the fan is the same, it can be said that the lower the static pressure, the slower the wind speed.

  For this reason, if the opening area of the opening 26a (the sum of the opening areas of the openings 26a) is increased while the rotational speed of the fan 38 is constant, the static pressure in the first cooling chamber 22 decreases, in other words, It turns out that the wind speed in 1 cooling chamber 22 becomes slow.

  In order to properly cool the tip of the heat pipe 15, a certain level of wind speed is required. Therefore, a wind speed sensor 61 is disposed in the first cooling chamber 22 where the wind speed is the slowest, that is, the lower portion of the first cooling chamber 22 as shown in FIG. 8, and the wind speed measured by the wind speed sensor 61 is equal to or greater than a predetermined value. Thus, it is preferable to control the rotation speed of the fan 38. When the rotation speed (supplied voltage) of the fan is increased, the curve indicating the relationship between the air volume and the static pressure moves upward as indicated by a broken line in FIG.

  Further, when the speed of the air flowing through the first cooling chamber 22 (wind speed) is decreased, the temperature of the air is increased. For this reason, the temperature sensor 62 is disposed in the portion where the temperature of the air is highest in the first cooling chamber 22, that is, the upper portion of the first cooling chamber 22, so that the temperature of the portion of the temperature sensor 62 becomes a predetermined temperature or less. Alternatively, the rotational speed of the fan 38 may be controlled.

  Thus, by measuring the temperature and wind speed in the first cooling chamber 22 and adjusting the rotational speed of the fan 38, it is possible to avoid a decrease in cooling efficiency.

  In addition, although the above-mentioned embodiment and the modifications 1 and 2 demonstrated the case where an electronic device was a computer (system board), the technique of indication can also be applied to cooling of electronic devices other than a computer. Moreover, although the heat pipe is used as the heat transport member in the above-described embodiment, the same effect can be obtained even if a heat medium circulation device or a heat transfer plate is used instead of the heat pipe.

  The following additional notes are disclosed with respect to the above embodiments.

(Appendix 1) a first area where electronic devices are installed;
A second area arranged adjacent to the first area and introduced with outside air;
A third area arranged adjacent to the second area and introduced with outside air;
A first separation wall separating the first area and the second area;
A second separation wall disposed between the second area and the third area, and provided with an opening that communicates the second area and the third area;
An electronic device cooling system, comprising: a heat transport member that penetrates the first separation wall and transports heat generated in the electronic device to the first area.

  (Additional remark 2) The said heat transport member is a heat pipe, The cooling system of the electronic device of Additional remark 1 characterized by the above-mentioned.

  (Supplementary note 3) A grill for introducing outside air is provided on the second area and the floor of the third area, and a blower for discharging the air of the second area to the ceiling on the second area. The cooling system for electronic equipment according to appendix 1 or 2, characterized in that is provided.

  (Supplementary Note 4) Any one of Supplementary Notes 1 to 3, wherein the opening of the second separation wall is disposed below the tip of the heat transport member in the second area. 2. A cooling system for electronic equipment according to item 1.

  (Supplementary note 5) The electronic device cooling system according to any one of supplementary notes 1 to 4, wherein an opening area of the opening of the second separation wall can be changed.

(Additional remark 6) It has a sensor which detects the temperature or the air volume of the front-end | tip part of the said heat transport member in the said 2nd area,
6. The electronic device cooling system according to appendix 5, wherein an opening area of the opening changes according to an output of the sensor.

  (Supplementary note 7) The electronic device cooling system according to any one of supplementary notes 1 to 6, wherein the electronic device is a computer housed in a rack.

  (Additional remark 8) It has an air conditioner which adjusts the temperature of said 1st area, The cooling system of the electronic device of any one of Additional remark 1 thru | or 7 characterized by the above-mentioned.

  (Supplementary note 9) The electronic device cooling system according to supplementary note 2, wherein the heat transport member is inclined by 50 degrees to 60 degrees with respect to a horizontal plane in the second area.

  (Additional remark 10) It has a sensor which detects the temperature in the said 2nd area, or a wind speed, The rotation speed of the said air blower changes according to the output of the said sensor, The electronic device of Additional remark 3 characterized by the above-mentioned Cooling system.

  DESCRIPTION OF SYMBOLS 10 ... Computer room, 12 ... Rack, 13 ... System board, 15 ... Heat pipe, 16 ... Radiation fin, 21 ... Equipment installation area, 22 ... First cooling room, 23 ... Second cooling room, 24, 25, 26 ... Separation wall 31 ... cold air flow path 32 ... warm air flow path 32a ... opening 33 ... outside air introduction path 34 ... outside air discharge path 35,36,37 ... grill, 38 ... fan 41 ... CPU 42 ... Heat sink, 50... Control unit, 51, 62... Temperature sensor, 61.

Claims (5)

A first area where electronic equipment is installed;
A second area arranged adjacent to the first area and introduced with outside air;
A third area arranged adjacent to the second area and introduced with outside air;
A first separation wall separating the first area and the second area;
A second separation wall disposed between the second area and the third area, and provided with an opening that communicates the second area and the third area;
An electronic machine cooling system comprising: a heat transporting member that passes through the first separation wall and transports heat generated by the electronic device to the second area.   The electronic device cooling system according to claim 1, wherein the heat transport member is a heat pipe.   Grills for introducing outside air are provided on the floors of the second area and the third area, and a blower for discharging the air of the second area to the outside is provided on the ceiling of the second area. The electronic apparatus cooling system according to claim 1, wherein the electronic apparatus cooling system is provided.   4. The electronic device cooling system according to claim 1, wherein an opening area of the opening of the second separation wall is changeable. 5.   The electronic device cooling system according to claim 1, wherein the electronic device is a computer stored in a rack.

Images