Server cooling system

Abstract

To provide a server cooling system capable of ensuring sufficient cooling performance.SOLUTION: A server cooling system includes a duct that forms a cylindrical shape extending vertically while an air exhaust port is formed in an upper section, an exhaust introduction section for introducing exhaust from a server room in a part below the air exhaust port in the duct, a fan that is provided in the duct and is rotated and driven such that air is exhausted from the air exhaust port, and a control device. The control device includes a fan operation section for rotating the fan from a stopped state when exhaust is introduced to the duct, and a fan stopping section for stopping the fan when a natural circulation condition is satisfied after the fan is rotated.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a server cooling system. [Background technology]

[0002] Servers are sensitive to heat, so if high temperatures continue in a server room, it can cause problems such as server breakdowns and a shortened lifespan. In order to safely manage servers, it is necessary to control the air conditioning in the server room where the servers are installed and cool the server room.

[0003] Patent Document 1 discloses an air conditioning duct system for central heating and cooling of a house. In this air conditioning duct system, a chimney is formed that penetrates from the first floor to the roof and has an upper end protruding onto the roof. Furthermore, a vertical duct is arranged inside the chimney. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-4732 Summary of the Invention [Problem to be solved by the invention]

[0005] When a vertical duct such as that disclosed in Patent Document 1 is used to exhaust air from within a server room, for example, the air inside the duct becomes hotter than the air outside the duct due to the high-temperature exhaust air from within the server room. This makes the air inside the duct lighter than the air outside the duct, and an upward flow occurs within the duct. The air outside the duct is drawn into the duct by the upward flow generated within the duct. This phenomenon is called the chimney effect. Due to this chimney effect, the high-temperature air within the server room is drawn into the duct and exhausted. However, the exhaust flow rate due to the chimney effect is small, and it was believed that the server room could not be sufficiently cooled.

[0006] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a server cooling system that can ensure sufficient cooling performance. [Means for solving the problem]

[0007] In order to solve the above problems, the server cooling system of the present disclosure includes a duct having a cylindrical shape extending in the vertical direction and with an air exhaust port formed at the upper part, an exhaust inlet section that introduces exhaust air from a server room into a section of the duct below the air exhaust port, a fan that is provided in the duct and driven to rotate so that air is exhausted from the air exhaust port, and a control device, wherein the control device has a fan operating section that rotates the fan from a stopped state when the exhaust air is introduced into the duct, and a fan stopping section that stops the fan when natural circulation conditions are satisfied after the fan has rotated.

[0008] The server cooling system of the present disclosure comprises a duct having a cylindrical shape extending in the vertical direction, with an air inlet formed at the bottom and an air exhaust formed at the top, a refrigerant inlet section that introduces circulating refrigerant from a server room between the air inlet and the air exhaust in the duct, a fan that is provided in the duct and driven to rotate so that air is exhausted from the air exhaust, and a control device, wherein the refrigerant inlet section has a heat exchange section that is disposed within the duct and performs heat exchange between the circulating refrigerant and the air in the duct, and the control device has a fan operating section that rotates the fan from a stopped state when the circulating refrigerant is introduced into the duct, and a fan stopping section that stops the fan when natural circulation conditions are satisfied after the fan has rotated. Effect of the Invention

[0009] According to the server cooling system of the present disclosure, sufficient cooling performance can be ensured. [Brief description of the drawings]

[0010] [Figure 1]1 is a configuration diagram of a server cooling system according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a perspective view illustrating the general shape of a duct according to the first embodiment of the present disclosure. [Diagram 3] FIG. 2 is a functional block diagram of a control device according to the first embodiment of the present disclosure. [Figure 4] 5 is a flowchart showing an operation procedure of the server cooling system according to the first embodiment of the present disclosure. [Diagram 5] FIG. 4 is a diagram showing the exhaust flow path and duct temperature changes over time according to the first embodiment of the present disclosure. [Figure 6] FIG. 11 is a configuration diagram of a server cooling system according to a second embodiment of the present disclosure. [Figure 7] FIG. 11 is a functional block diagram of a control device according to a second embodiment of the present disclosure. [Figure 8] 10 is a flowchart showing an operation procedure of the server cooling system according to the second embodiment of the present disclosure. [Figure 9] FIG. 11 is a configuration diagram of a refrigerant introduction section according to a modified example of the second embodiment of the present disclosure. [Figure 10] FIG. 11 is a configuration diagram of a server cooling system according to a third embodiment of the present disclosure. [Figure 11] 13 is a flowchart showing an operation procedure of the server cooling system according to the third embodiment of the present disclosure. [Figure 12] FIG. 13 is a configuration diagram of a server cooling system according to a modified example of the third embodiment of the present disclosure. [Figure 13] FIG. 13 is a configuration diagram of a server cooling system according to another embodiment of the present disclosure. [Figure 14] FIG. 13 is a configuration diagram of a server cooling system according to another embodiment of the present disclosure. [Figure 15] FIG. 13 is a cross-sectional view along a horizontal plane of a duct according to another embodiment of the present disclosure. [Figure 16] FIG. 13 is a configuration diagram of a server cooling system according to another embodiment of the present disclosure. [Figure 17] FIG. 2 is a hardware configuration diagram showing the configuration of a computer according to each embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First Embodiment (Server cooling system configuration) A server cooling system 100 according to a first embodiment of the present disclosure will be described below with reference to Figures 1 to 5. In Figures 1 and 2, the flow of air is indicated by arrows. A server 2 is installed in a server room 1. The server 2 generates heat during operation. The heat from the server 2 causes the temperature inside the server room 1 to become high. A server cooling system 100 is used to cool the server room 1. As shown in FIG. 1, the server cooling system 100 includes a duct 10, an exhaust air intake section 20, a fan 3, a damper 30, a temperature sensor 4, a control device 40, and a display section 5. An air intake 1b is formed in the server room 1. Air outside the server room 1 is supplied to the server room 1 through the air intake 1b. High-temperature air in the server room 1 that has been heated by the servers 2 is exhausted through an exhaust introduction section 20 and a duct 10, which will be described later.

[0012] (duct) The duct 10 has a cylindrical shape extending in the vertical direction Dv. The duct 10 is disposed along the side wall 1a of the server room 1 extending in the vertical direction Dv. The length of the duct 10 can be changed as appropriate. However, the length of the duct 10 is preferably, for example, 1 m or more and 500 m or less. In this embodiment, the lower end of the duct 10 is closed. An air exhaust port 11 is formed in the upper part of the duct 10. The duct 10 has a first cylindrical portion 10a and a second cylindrical portion 10b. The first cylindrical portion 10a extends in the vertical direction Dv along the side wall 1a of the server room 1. The second cylindrical portion 10b is provided at the upper end of the first cylindrical portion 10a. The second cylindrical portion 10b is connected to the first cylindrical portion 10a. The second cylindrical portion 10b extends upward from the upper end of the first cylindrical portion 10a. The second cylindrical portion 10b extends in such a way that it gradually faces in a horizontal direction away from the side wall 1a as it faces upward. The second cylindrical portion 10b has an opening at the end opposite to the first cylindrical portion 10a. This opening is the air exhaust port 11 of the duct 10. The air exhaust port 11 faces slightly downward. In other words, the opening direction of the air exhaust port 11 has a downward direction component.

[0013] The duct 10 has a fan exhaust port 12 in the second cylindrical portion 10b. The fan exhaust port 12 is provided in a direction facing the side wall 1a of the server room 1, separate from the air exhaust port 11. The fan exhaust port 12 is provided to penetrate the duct 10, and connects the inside and outside of the duct 10. Multiple fan exhaust ports 12 (four in this embodiment) are arranged in the horizontal direction.

[0014] (Exhaust intake) The exhaust introduction part 20 extends from the inside of the server room 1 to the first cylindrical part 10a of the duct 10. The exhaust introduction part 20 is a pipe penetrating the side wall 1a of the server room 1. The exhaust introduction part 20 introduces high-temperature exhaust air from the server room 1 to a part of the duct 10 below the air exhaust port 11. In this embodiment, the exhaust introduction part 20 is formed in a tubular shape extending in the horizontal direction. As shown in FIG. 2, multiple exhaust introduction parts 20 (four in this embodiment) are arranged in the horizontal direction. The exhaust introduction parts 20 are in communication with the duct 10.

[0015] (fan) The fan 3 is provided in the second cylindrical portion 10b of the duct 10. The fan 3 is arranged so as to face the side wall 1a of the server room 1. The fan 3 is attached to each fan exhaust port 12, and a plurality of fans (four in this embodiment) are arranged in the horizontal direction. The fan 3 is rotationally driven so as to exhaust air from the air exhaust port 11.

[0016] (Damper) Damper 30 is provided at air exhaust port 11 and opens and closes air exhaust port 11. Here, if a state in which damper 30 opens air exhaust port 11 is referred to as an open state, and a state in which damper 30 closes air exhaust port 11 is referred to as a closed state, in Fig. 1, the open state of damper 30 is illustrated by a solid line, and the closed state of damper 30 is illustrated by a dashed line.

[0017] (Temperature Sensor) The temperature sensor 4 detects the temperature inside the duct 10. The temperature sensor 4 is attached to the inner surface of the first cylindrical portion 10a of the duct 10.

[0018] (Control device) The control device 40 is electrically connected to the server 2, the fan 3, the damper 30, and the temperature sensor 4. As shown in Fig. 3, the control device 40 has each of functional units, an acquisition unit 41, a determination unit 42, a fan operation unit 43, a fan stopping unit 44, a damper closing unit 45, and a damper opening unit 46.

[0019] The acquisition unit 41 acquires information from the outside. For example, the acquisition unit 41 acquires information on whether the server 2 is in operation. The acquisition unit 41 also acquires the temperature inside the duct 10 detected by the temperature sensor 4.

[0020] The determination unit 42 determines whether or not the natural circulation condition is satisfied. The natural circulation condition is a condition in which air of a volume sufficient to cool the server 2 can naturally circulate inside the duct 10 only by the chimney effect caused by the inside of the duct 10 being hotter than the outside of the duct 10. The determination unit 42 in this embodiment determines that the natural circulation condition is satisfied when the temperature detected by the temperature sensor 4 exceeds a predetermined threshold value.

[0021] The fan operating unit 43 starts rotating the fan 3 from a stopped state when exhaust air is introduced into the duct 10. In addition, the fan operating unit 43 can adjust the rotation speed of the fan 3 to adjust the exhaust flow rate by the fan 3. The fan stop unit 44 stops the fan 3 when the natural circulation condition is satisfied after the fan 3 starts rotating.

[0022] The damper closing unit 45 operates the damper 30 to close the air exhaust port 11, for example, before the fan 3 starts rotating. The damper opening unit 46 operates the damper 30 to open the air exhaust port 11, for example, after the fan 3 has rotated.

[0023] (Display) The display unit 5 is connected to the control device 40. The display unit 5 displays the state of the server cooling system 100 in real time. Examples of information displayed on the display unit 5 include the temperature of the duct 10 detected by the temperature sensor 4 and the volume of air flowing through the duct 10. In this embodiment, the exhaust flow rate by the fan 3 and the exhaust flow rate by the chimney effect are displayed separately.

[0024] (Server cooling system operation) Next, the operation procedure of the server cooling system 100 will be described with reference to the flow of FIG. When the server 2 starts operating, the room temperature of the server room 1 rises due to the heat of the server 2. Then, high-temperature exhaust air is introduced from the server room 1 into the duct 10. The acquisition unit 41 acquires information that the server 2 has started operating (step S11). Immediately after step S11, or after a predetermined time has elapsed, the damper closing unit 45 operates the damper 30 to close the air exhaust port 11 (step S12). Immediately thereafter, the fan operation unit 43 rotates the fan 3 that is in a stopped state (step S13). The rotation of the fan 3 introduces high-temperature air in the server room 1 into the duct 10. The high-temperature exhaust air introduced into the duct 10 is exhausted to the outside of the server room 1 from the fan exhaust port 12. In this way, immediately after the server 2 starts operating, the high-temperature air in the server room 1 is forcibly exhausted by the forced exhaust by the fan 3.

[0025] Here, the time changes in the exhaust flow rate and temperature of the duct 10 from step S13 are as shown in Fig. 5. The horizontal axis of Fig. 5 is elapsed time, and the vertical axis of Fig. 5 is the temperature of the duct 10 or the exhaust flow rate of the duct 10. In Fig. 5, the temperature of the duct 10 is displayed by a solid line. Also in Fig. 5, the exhaust flow rate by the fan 3 is displayed by a dashed line, and the exhaust flow rate due to the chimney effect is displayed by a dashed line. The time changes in the exhaust flow rate and temperature of the duct 10 as shown in Fig. 5 are displayed on the display unit 5, for example.

[0026] In this embodiment, the exhaust flow rate by the fan 3 is controlled while monitoring the indoor temperature of the duct 10. When the fan 3 starts to rotate, the exhaust flow rate by the fan 3 increases rapidly, as shown in Fig. 5. This increases the exhaust flow rate sent from the server room 1 to the duct 10, and the temperature inside the duct 10 increases. When the temperature inside the duct 10 increases, an upward flow due to thermal convection occurs inside the duct 10, and the exhaust flow rate of the duct 10 increases (chimney effect).

[0027] When a predetermined time has elapsed since the fan 3 started rotating, the rotation speed of the fan 3 is reduced. As a result, the exhaust flow rate by the fan 3 gradually decreases. Furthermore, as the temperature rises, the damper opening unit 46 operates the damper 30 to gradually increase the opening of the air exhaust port 11 (step S14). As a result, the exhaust flow rate by the chimney effect gradually increases. In this way, forced exhaust by the fan 3 and natural exhaust by the chimney effect are used together, and the proportion of natural exhaust by the chimney effect increases over time.

[0028] Thereafter, the determination unit 42 determines whether or not the natural circulation condition is satisfied, in which an air volume sufficient to cool the server 2 can naturally circulate in the duct 10 by the chimney effect alone (step S15). In this embodiment, the temperature in the duct 10 becomes a substantially constant value (e.g., 40°C) over time. The determination unit 42 uses this constant temperature in the duct 10 as a threshold value, and It is determined that the natural circulation condition is satisfied when the temperature detected by the temperature sensor 4 exceeds a predetermined threshold value. This threshold value can be changed appropriately depending on the conditions.

[0029] If the natural circulation condition is met (step S15; YES), the damper opening unit 46 operates the damper 30 to completely open the air exhaust port 11 (step S16). After that, the fan stopping unit 44 stops the fan 3 (step S17). Step S17 completely switches from forced exhaust by the fan 3 to natural exhaust by the chimney effect. After step S17, the high-temperature air in the server room 1 is exhausted by the natural circulation of air in the duct 10 due to the chimney effect. This cools the server room 1, and the room temperature in the server room 1 is kept constant. Through the above steps, the cooling system is operated.

[0030] It is possible to appropriately change the operation procedure of the server cooling system 100. For example, steps S12 and S13 may be performed simultaneously. Also, steps S16 and S17 may be performed simultaneously.

[0031] (Action and effect) In this embodiment, the server cooling system 100 includes a duct 10, an exhaust air introduction section 20, a fan 3, and a control device 40. The duct 10 is cylindrical and extends in the vertical direction Dv. An air exhaust port 11 is formed in the upper part of the duct 10. The exhaust air introduction section 20 is provided in a portion of the duct 10 below the air exhaust port 11. The exhaust air introduction section 20 introduces exhaust air from the server room 1. The fan 3 is provided in the duct 10. The fan 3 is driven to rotate so that air is exhausted from the air exhaust port 11. The control device 40 includes a fan operating section 43 and a fan stopping section 44. The fan operating section 43 rotates the fan 3 from a stopped state when exhaust air from the server room 1 is introduced into the duct 10. The fan stopping section 44 stops the fan 3 when a natural circulation condition is satisfied after the fan 3 rotates.

[0032] According to the above configuration, when high-temperature exhaust air from the server room 1 is introduced into the duct 10, the control device 40 rotates the fan 3, which is in a stopped state. As a result, for a while after the start of exhaust, the air in the server room 1 is forcibly exhausted by the blowing force of the fan 3. Since high-temperature exhaust air from the server room 1 is supplied into the duct 10, the temperature inside the duct 10 becomes higher than the temperature outside the duct 10. As a result, an upward flow is generated in the duct 10. The air in the server room 1 is drawn into the duct 10 by this upward flow. This phenomenon is called the chimney effect. Immediately after the start of exhaust, the exhaust flow rate due to the chimney effect is small, but a large amount of high-temperature exhaust air is forcibly supplied into the duct 10 by the fan 3. As a result, the temperature of the duct 10 rises rapidly, and the exhaust flow rate due to the chimney effect increases. After that, the air is sufficiently exhausted from the server room 1 only by the exhaust flow rate due to the chimney effect. The condition under which this state occurs is called the natural circulation condition. In this embodiment, when this natural circulation condition is satisfied, the control device 40 stops the fan 3. As a result, the high-temperature air in the server room 1 is sufficiently exhausted only by the chimney effect, and the server room 1 is sufficiently cooled. Therefore, according to this embodiment, it is finally possible to ensure sufficient cooling performance by utilizing the natural circulation of air due to the chimney effect.

[0033] In this embodiment, the server cooling system 100 further includes a temperature sensor 4 that detects the temperature inside the duct 10. The control device 40 has a determination unit 42 that determines whether or not the natural circulation condition is satisfied. The determination unit 42 determines that the natural circulation condition is satisfied when the temperature detected by the temperature sensor 4 exceeds a predetermined threshold value.

[0034] This allows the determination unit 42 to determine whether or not the natural circulation condition is satisfied from the temperature of the duct 10. This allows the control device 40 to accurately determine whether or not the natural circulation condition is satisfied.

[0035] It is not necessary to provide the temperature sensor 4. In this case, for example, the determination unit 42 may determine that the natural circulation condition is satisfied when a predetermined time has elapsed since the fan 3 started to rotate.

[0036] In this case, the determination unit 42 can determine whether or not the natural circulation condition is satisfied from the time that has elapsed since the start of rotation of the fan 3. There is no need to provide a separate device for determining whether the natural circulation condition is satisfied, and the configuration of the server cooling system 100 can be simplified.

[0037] In this embodiment, the server cooling system 100 further includes a damper 30 that opens and closes the air exhaust port 11. The duct 10 further includes a fan exhaust port 12 that is provided separately from the air exhaust port 11. A fan 3 is attached to the fan exhaust port 12. The control device 40 further includes a damper closing unit 45 and a damper opening unit 46. The damper closing unit 45 operates the damper 30 to close the air exhaust port 11 before the fan 3 starts to rotate. The damper opening unit 46 operates the damper 30 to open the air exhaust port 11 after the fan 3 has rotated.

[0038] As a result, when the fan 3 rotates, the server cooling system 100 can exhaust air from inside the duct 10 using the fan exhaust port 12 where the fan 3 is installed as the main exhaust port. Therefore, the server cooling system 100 can efficiently exhaust air using the fan 3. Furthermore, after the exhaust flow rate due to the chimney effect has increased sufficiently, the fan 3 is stopped and the air exhaust port 11 is opened to exhaust the air inside the duct 10 from both the fan exhaust port 12 and the air exhaust port 11. Therefore, when the fan 3 is stopped, the server cooling system 100 can increase the opening area of ​​the exhaust port to increase the exhaust flow rate. Therefore, according to this embodiment, the server cooling system 100 can efficiently exhaust the air inside the duct 10 according to the timing, and the cooling efficiency of the server cooling system 100 is further improved.

[0039] In this embodiment, the duct 10 has a first cylindrical portion 10a extending in the vertical direction Dv, and a second cylindrical portion 10b provided at the upper end of the first cylindrical portion 10a and communicating with the first cylindrical portion 10a. The second cylindrical portion 10b extends so as to gradually face in a direction away from the side wall 1a in the horizontal direction as it goes upward. The second cylindrical portion 10b has an air exhaust port 11 at the end opposite to the first cylindrical portion 10a. The second cylindrical portion 10b is curved so that the air exhaust port 11 faces slightly downward. This prevents rainwater and the like from entering the duct 10 through the air exhaust port 11.

[0040] <Second embodiment> (Server cooling system configuration) A server cooling system 200 according to a second embodiment of the present disclosure will be described below with reference to Figs. 6 to 8. Configurations similar to those in the above-described embodiment will be given the same names and symbols, and descriptions thereof will be omitted as appropriate. In Fig. 6, in addition to the flow of air, the flow of a circulating refrigerant R, which will be described later, is illustrated by arrows.

[0041] In this embodiment, in addition to the intake port 1b, an exhaust port 1c is formed in the server room 1. The exhaust port 1c exhausts high-temperature air from within the server room 1 to the outside of the server room 1.

[0042] Furthermore, the duct 10 has an air inlet 13 formed at a lower portion in addition to the air outlet 11 formed at an upper portion. The air inlet 13 is provided at the lower end of the first cylindrical portion 10a of the duct 10. The air inlet 13 penetrates the first cylindrical portion 10a in the up-down direction Dv. The air inlet 13 supplies outside air into the duct 10. The air introduced into the duct 10 from the air inlet 13 is discharged to the outside of the duct 10 through the air outlet 11.

[0043] (Refrigerant introduction section) Moreover, the server cooling system 200 includes a refrigerant introduction section 50 instead of the exhaust air introduction section 20. The refrigerant introduction section 50 introduces the circulating refrigerant R from the server room 1 between the air inlet 13 and the air exhaust outlet 11 in the vertical direction Dv. The circulating refrigerant R absorbs heat in the server room 1 and is then supplied into the duct 10. The circulating refrigerant R is supplied into the duct 10 after directly exchanging heat with the servers 2, for example.

[0044] The refrigerant introduction section 50 has a heat exchange section 51 , a refrigerant supply pipe 52 , and a refrigerant discharge pipe 53 . The heat exchange unit 51 is disposed in the duct 10 to perform heat exchange between the circulating refrigerant R and the air in the duct 10. In this embodiment, the heat exchange unit 51 is disposed in the first cylindrical portion 10a of the duct 10.

[0045] The refrigerant supply pipe 52 extends horizontally from within the server room 1 and is connected to the heat exchange unit 51. The refrigerant supply pipe 52 penetrates the side wall 1a of the server room 1 and the first cylindrical portion 10a of the duct 10. The refrigerant supply pipe 52 supplies the circulating refrigerant R that has absorbed heat from the server room 1 to the heat exchange unit 51. The refrigerant discharge pipe 53 extends horizontally from the heat exchange unit 51 into the server room 1. The refrigerant discharge pipe 53 penetrates the side wall 1a of the server room 1 and the first cylindrical portion 10a of the duct 10. The refrigerant discharge pipe 53 returns the circulating refrigerant R that has been cooled by exchanging heat with the air in the servers 2 in the heat exchange unit 51 to the inside of the server room 1. The circulating refrigerant R returned from the refrigerant discharge pipe 53 to the inside of the server room 1 absorbs heat in the server room 1 again, and is then supplied to the heat exchange unit 51 through the refrigerant supply pipe 52.

[0046] (Control device) As shown in FIG. 7, the control device 40 further has a refrigerant operation unit 47 as a functional unit. The refrigerant operation unit 47 operates the refrigerant introduction unit 50 to introduce the circulating refrigerant R into the duct 10. Furthermore, when the circulating refrigerant R is introduced into the duct 10, the fan operating unit 43 of this embodiment starts rotating the fan 3 from a stopped state.

[0047] (Server cooling system operation) Next, the operation procedure of the server cooling system 200 will be described with reference to the flow of FIG. When the server 2 is operated, the temperature of the server room 1 rises due to the heat of the server 2. The acquisition unit 41 acquires information that the server 2 is operating (step S21). Immediately after step S21, the refrigerant operation unit 47 operates the refrigerant introduction unit 50 to introduce the circulating refrigerant R into the duct 10 (step S22). Immediately after that, or after a predetermined time has elapsed, the damper closing unit 45 operates the damper 30 to close the air exhaust port 11 (step S23). Immediately after that, the fan operation unit 43 rotates the fan 3 that is in a stopped state (step S24). The rotation of the fan 3 introduces outside air into the duct 10 from the air inlet port 13. The air introduced into the duct 10 is discharged from the fan exhaust port 12. In this way, immediately after the server 2 is operated, the air in the duct 10 is forcibly exhausted by the forced exhaust by the fan 3. The outside air introduced into the duct 10 cools the circulating refrigerant R introduced into the duct 10 by the refrigerant introduction part 50. The circulating refrigerant R cooled in the duct 10 is returned into the server room 1.

[0048] The heat transferred from the circulating refrigerant R increases the exhaust flow rate sent from the server room 1 to the duct 10, and the temperature inside the duct 10 rises. When the temperature inside the duct 10 rises, an upward flow due to thermal convection occurs inside the duct 10, and the exhaust flow rate of the duct 10 increases (chimney effect).

[0049] In this embodiment as well, the exhaust flow rate by the fan 3 is controlled while monitoring the indoor temperature of the duct 10. When a predetermined time has passed since the fan 3 started rotating, the rotation speed of the fan 3 is reduced. As a result, the exhaust flow rate by the fan 3 gradually decreases. Furthermore, as the temperature rises, the damper opening unit 46 operates the damper 30 to gradually increase the opening of the air exhaust port 11 (step S25). As a result, the exhaust flow rate by the chimney effect gradually increases. In this way, forced exhaust by the fan 3 and natural exhaust by the chimney effect are used together, and the proportion of natural exhaust by the chimney effect increases over time.

[0050] Thereafter, the determination unit 42 determines whether or not the natural circulation condition is satisfied, that is, the air volume sufficient to cool the server 2 is naturally circulated through the duct 10 by the chimney effect alone (step S26). In the present embodiment, as in the first embodiment, the determination unit 42 determines that the natural circulation condition is satisfied when the temperature detected by the temperature sensor 4 exceeds a predetermined threshold value.

[0051] If the natural conditions are met (step S26; YES), the damper opening unit 46 operates the damper 30 to completely open the air exhaust port 11 (step S27). After that, the fan stopping unit 44 stops the fan 3 (step S28). Step S28 completely switches from forced exhaust by the fan 3 to natural exhaust by the chimney effect. After step S28, fresh air continues to be supplied to the duct 10 due to the natural circulation of air in the duct 10 caused by the chimney effect. This allows the circulating refrigerant that has absorbed the heat of the server room 1 to be sufficiently cooled in the duct 10. The circulating refrigerant R cooled in the duct 10 is returned to the server room 1 and cools the server room 1. This keeps the room temperature in the server room 1 constant. Through the above steps, the cooling system is operated.

[0052] It is possible to appropriately change the operation procedure of the server cooling system 200. For example, steps S23 and S24 may be performed simultaneously. Also, steps S27 and S28 may be performed simultaneously.

[0053] (Action and effect) In this embodiment, the server cooling system 200 includes a duct 10, a refrigerant introduction section 50, a fan 3, and a control device 40. The duct 10 has a cylindrical shape extending in the vertical direction Dv. An air inlet 13 is formed at the bottom of the duct 10, and an air outlet 11 is formed at the top of the duct 10. The refrigerant introduction section 50 introduces the circulating refrigerant R from the server room 1 between the air inlet 13 and the air outlet 11 in the duct 10. The refrigerant introduction section 50 has a heat exchange section 51 that is disposed in the duct 10 and exchanges heat between the circulating refrigerant R and the air in the duct 10. The fan 3 is provided in the duct 10. The fan 3 is driven to rotate so that air is discharged from the air outlet 11. The control device 40 has a fan operation section 43 and a fan stop section 44. The fan operation section 43 rotates the fan 3 from a stopped state when the circulating refrigerant R is introduced into the duct 10. The fan stop unit 44 stops the fan 3 when the natural circulation condition is satisfied after the fan 3 starts rotating.

[0054] According to the above configuration, when high-temperature circulating refrigerant is introduced into the duct 10 from the server room 1, the control device 40 rotates the stopped fan 3. This makes it possible to forcibly exhaust air from the inside of the duct 10 by the blowing force of the fan 3 for a while after the start of exhaust. The circulating refrigerant R is supplied into the duct 10 after collecting heat from within the server room 1. The refrigerant supplied into the duct 10 supplies heat to the air in the duct 10 by the heat exchanger 51. The air in the duct 10 is heated by this heat, and the air in the duct 10 becomes hotter than the air outside the duct 10. This generates an upward flow in the duct 10. This upward flow draws the air in the server room 1 into the duct 10 (chimney effect). Immediately after the start of exhaust, the exhaust flow rate due to the chimney effect is small, but the heat of the circulating refrigerant R heats the inside of the duct 10, and the temperature of the duct 10 rises rapidly. This increases the exhaust flow rate due to the chimney effect. After that, the air is sufficiently exhausted from the inside of the duct 10 only by the exhaust flow rate due to the chimney effect, and the natural circulation condition is satisfied. In this embodiment, when this natural circulation condition is satisfied, the control device 40 stops the fan 3. This allows the air in the duct 10 to be sufficiently exhausted only by the chimney effect. Therefore, heat exchange between the circulating refrigerant R and the air is efficiently performed, and the inside of the server room 1 can be sufficiently cooled by the air flowing through the duct 10 via the circulating refrigerant R. Therefore, according to this embodiment, it is possible to ensure sufficient cooling performance by utilizing the natural circulation of air due to the chimney effect.

[0055] 9, the refrigerant introduction section 50 may further have fins 57 provided on the outer surface of the heat exchange section 51. Specifically, the refrigerant introduction section 50 has a supply side header 54, a discharge side header 55, a connecting pipe 56, and the fins 57.

[0056] The supply side header 54 is connected to the refrigerant supply pipe 52. The supply side header 54 is supplied with a circulating refrigerant. The discharge header 55 is connected to the refrigerant discharge pipe 53. The discharge header 55 discharges the circulating refrigerant R, which has been cooled by exchanging heat with the air in the duct 10 in the heat exchange section 51, to the refrigerant discharge pipe 53.

[0057] The connecting pipe 56 connects the supply side header 54 and the discharge side header 55. A plurality of connecting pipes 56 are provided. The fins 57 are attached so as to protrude from the outer circumferential surface of the connecting pipe 56. The fins 57 are formed in a plate shape. A plurality of fins 57 are provided. Each fin 57 is attached so as to be penetrated by a plurality of the connecting pipes 56.

[0058] As described above, in this modification, the refrigerant introduction section 50 further has the fins 57 provided on the outer surface of the heat exchange section 51.

[0059] As a result, the fins 57 increase the surface area of ​​the heat exchanger 51. This improves the heat exchange efficiency of the heat exchanger 51. This further improves the cooling performance of the server cooling system 100.

[0060] Also in this embodiment, similarly to the first embodiment, the temperature sensor 4 may not be provided. In this case, the determination unit 42 may determine that the natural circulation condition is satisfied when a predetermined time has elapsed since the fan 3 started to rotate.

[0061] <Third embodiment> (Server cooling system configuration) Hereinafter, a server cooling system 300 according to a third embodiment of the present disclosure will be described with reference to Figs. 10 and 11. Configurations similar to those in the above-described embodiments will be given the same names and symbols, and descriptions thereof will be omitted as appropriate. In Fig. 10, in addition to the flow of air, the flow of a circulating refrigerant R, which will be described later, is illustrated by arrows.

[0062] In this embodiment, as shown in FIG. 10, the lower end of the first cylindrical portion 10a of the duct 10 is closed, similarly to the first embodiment. Moreover, the server cooling system 300 of the present embodiment includes the exhaust gas introduction part 20 of the first embodiment and the refrigerant introduction part 50 of the second embodiment. The refrigerant introduction part 50 is provided below the exhaust gas introduction part 20. As in the second embodiment, the refrigerant introduction part 50 supplies the circulating refrigerant R that has absorbed heat from the server room 1 into the duct 10, and exchanges heat with the air in the duct 10 in the heat exchange part 51.

[0063] The circulating refrigerant R supplied into the duct 10 is cooled as heat is absorbed by the air in the duct 10. Thereafter, the circulating refrigerant R is returned to the server room 1 again. If the circulating refrigerant R is not sufficiently cooled within the duct 10, the circulating refrigerant R may be further cooled by connecting the refrigerant discharge pipe 53 to a separate heat exchanger (not shown) such as a chiller.

[0064] The fan operating unit 43 of the present embodiment rotates the fan 3 from a stopped state when exhaust air from the server room 1 is introduced into the duct 10 and the circulating refrigerant R is introduced into the duct 10.

[0065] (Server cooling system operation) Next, the operation procedure of the server cooling system 300 will be described with reference to the flow of FIG. When the server 2 is operated, the room temperature of the server room 1 rises due to the heat of the server 2. Then, high-temperature exhaust air is introduced from the server room 1 into the duct 10. The acquisition unit 41 acquires information that the server 2 is operating (step S31). Immediately after step S31, the refrigerant operation unit 47 operates the refrigerant introduction unit 50 to introduce the circulating refrigerant into the duct 10 (step S32). Immediately after that, or after a predetermined time has elapsed, the damper closing unit 45 operates the damper 30 to close the air exhaust port 11 (step S33). Immediately after that, the fan operation unit 43 rotates the fan 3 that is in a stopped state (step S34). The rotation of the fan 3 introduces high-temperature air in the server room 1 into the duct 10. The high-temperature exhaust air introduced into the duct 10 is exhausted to the outside of the server room 1 from the fan exhaust port 12. In this way, immediately after the server 2 is operated, the high-temperature air in the server room 1 is forcibly exhausted by the forced exhaust by the fan 3.

[0066] In this embodiment, the exhaust flow rate by the fan 3 is also controlled while monitoring the indoor temperature of the duct 10. When the fan 3 starts rotating, the exhaust flow rate sent from the server room 1 to the duct 10 increases, and the temperature inside the duct 10 rises. In addition, a circulating refrigerant R that has absorbed heat from the server room 1 is supplied into the duct 10. The air in the duct 10 is heated by the circulating refrigerant R from the server room 1, and the temperature in the duct 10 further increases.

[0067] When the temperature inside the duct 10 rises, an upward flow occurs inside the duct 10 due to thermal convection, and the exhaust flow rate of the duct 10 increases (chimney effect).

[0068] When a predetermined time has elapsed since the fan 3 started rotating, the rotation speed of the fan 3 is reduced. As a result, the exhaust flow rate by the fan 3 gradually decreases. Furthermore, as the temperature rises, the damper opening unit 46 operates the damper 30 to gradually increase the opening of the air exhaust port 11 (step S35). As a result, the exhaust flow rate by the chimney effect gradually increases. In this way, forced exhaust by the fan 3 and natural exhaust by the chimney effect are used together, and the proportion of natural exhaust by the chimney effect increases over time.

[0069] When a predetermined time has elapsed since the fan 3 started rotating, the rotation speed of the fan 3 is reduced. As a result, the exhaust flow rate by the fan 3 gradually decreases. Furthermore, as the temperature rises, the damper opening unit 46 operates the damper 30 to gradually increase the opening of the air exhaust port 11 (step S35). As a result, the exhaust flow rate by the chimney effect gradually increases. In this way, forced exhaust by the fan 3 and natural exhaust by the chimney effect are used together, and the proportion of natural exhaust by the chimney effect increases over time.

[0070] Thereafter, the determination unit 42 determines whether or not the natural circulation condition is satisfied, that is, the air volume sufficient to cool the server 2 is naturally circulated through the duct 10 by the chimney effect alone (step S37). In the present embodiment, as in the first embodiment, the determination unit 42 determines that the natural circulation condition is satisfied when the temperature detected by the temperature sensor 4 exceeds a predetermined threshold value.

[0071] If the natural conditions are met (step S37; YES), the damper opening unit 46 operates the damper 30 to completely open the air exhaust port 11 (step S37). Thereafter, the fan stopping unit 44 stops the fan 3 (step S38). Step S38 completely switches from forced exhaust by the fan 3 to natural exhaust by the chimney effect. After step S38, the high-temperature air in the server room 1 is exhausted by the natural circulation of air in the duct 10 due to the chimney effect. This cools the server room 1, and the room temperature in the server room 1 is kept constant. Through the above steps, the cooling system is operated.

[0072] It is possible to appropriately change the operation procedure of the server cooling system 300. For example, steps S33 and S34 may be performed simultaneously. Also, steps S37 and S38 may be performed simultaneously.

[0073] (Action and effect) In this embodiment, the server cooling system 300 further includes a refrigerant introduction unit 50. The refrigerant introduction unit 50 introduces the circulating refrigerant R from the server room 1 below the air exhaust port 11 in the duct 10. The refrigerant introduction unit 50 has a heat exchange unit 51. The heat exchange unit 51 is disposed in the duct 10 and performs heat exchange between the circulating refrigerant R and the air in the duct 10. The fan operation unit 43 rotates the fan 3 from a stopped state when exhaust air from the server room 1 is introduced into the duct 10 and the circulating refrigerant R is introduced into the duct 10.

[0074] As a result, the circulating refrigerant R is supplied into the duct 10 while collecting heat from within the server room 1. The circulating refrigerant R supplied into the duct 10 supplies heat to the air within the duct 10 via the heat exchanger 51. This heat further heats the air within the duct 10, increasing the exhaust flow rate due to the chimney effect. This makes it possible to exhaust a larger amount of high-temperature air from within the duct 10, further improving the cooling performance.

[0075] As shown in FIG. 12, the server cooling system 300 may further include a first earthquake-resistant member 6 and a second earthquake-resistant member 7.

[0076] The first earthquake-resistant member 6 is provided at the connection between the exhaust inlet 20 and the side wall 1a of the server room 1. The first earthquake-resistant member 6 is, for example, a rubber damper attached to the outer circumferential surface of the exhaust inlet 20. The first earthquake-resistant member 6 contracts to absorb vibrations transmitted to the duct 10 via the side wall 1a.

[0077] The second earthquake-resistant member 7 is provided at the connection between the refrigerant introduction part 50 and the side wall 1a of the server room 1. The second earthquake-resistant member 7 is, for example, a rubber damper attached to the outer circumferential surface of the refrigerant supply pipe 52 and the outer circumferential surface of the refrigerant discharge pipe 53. The second earthquake-resistant member 7 contracts, thereby absorbing vibrations transmitted to the duct 10 via, for example, the side wall 1a. In this way, even if the duct 10 is located away from the side wall 1a of the server room 1, the first earthquake-resistant member 6 and the second earthquake-resistant member 7 can absorb the vibrations of the duct 10, thereby ensuring the earthquake resistance of the duct 10. The first earthquake-resistant member 6 and the second earthquake-resistant member 7 are not limited to rubber dampers. For example, the first earthquake-resistant member 6 and the second earthquake-resistant member 7 may be configured to absorb vibrations by a bellows structure.

[0078] The above-mentioned first earthquake-resistant member 6 is applicable to the server cooling system 100 of the first embodiment. Moreover, the second earthquake-resistant member 7 is applicable to the server cooling system 200 of the second embodiment.

[0079] Also in this embodiment, similarly to the first embodiment, the temperature sensor 4 may not be provided. In this case, the determination unit 42 may determine that the natural circulation condition is satisfied when a predetermined time has elapsed since the fan 3 started to rotate.

[0080] Also in this embodiment, similarly to the second embodiment, the heat exchange section 51 of the refrigerant introduction section 50 may have fins 57 on the outer circumferential surface. That is, the heat exchange section 51 may have a supply side header 54, a discharge side header 55, a connecting pipe 56, and fins 57.

[0081] (Other embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the gist of the present disclosure are also included.

[0082] 13, the server cooling system 100 may further include a heat insulating material 8. The heat insulating material 8 is provided on a side surface 10c of the outer circumferential surface of the duct 10 that faces away from the side wall 1a of the server room 1.

[0083] The heat insulating material 8 prevents the air in the duct 10 from radiating heat to the outside of the duct 10. This prevents a decrease in the temperature of the air in the duct 10. Therefore, according to this embodiment, the server cooling system 100 can prevent a decrease in the exhaust flow rate due to the chimney effect.

[0084] The location of the heat insulating material 8 can be changed as appropriate. For example, the heat insulating material 8 may be provided on the entire outer periphery of the first cylindrical portion 10a of the duct 10. The heat insulating material 8 may also be provided on the inner surface of the duct 10.

[0085] 14, the server cooling system 100 may further include a heating mechanism 60. The heating mechanism 60 is provided on a side surface 10c of the outer circumferential surface of the duct 10 that faces away from the side wall 1a of the server room 1. The heating mechanism 60 heats the air inside the duct 10. The heating mechanism 60 is, for example, an absorbing material 61 that absorbs sunlight.

[0086] The heating mechanism 60 heats the air in the duct 10. This suppresses a decrease in the temperature of the air in the duct 10. Therefore, according to this embodiment, the server cooling system 100 can suppress a decrease in the exhaust flow rate due to the chimney effect. Moreover, the heating mechanism 60 of this modified example is an absorbing material 61 that absorbs sunlight. Therefore, the air in the duct 10 can be heated by the energy of sunlight.

[0087] 15, the side surface 10c of the duct 10 on which the absorbent 61 is installed is curved. This makes it possible to increase the surface area of ​​the absorbent 61 compared to when the side surface 10c is a flat surface. Thus, the absorbent 61 can absorb more sunlight.

[0088] It is possible to appropriately change the location where the absorbing material 61 is provided. For example, the absorbing material 61 may be provided on the entire outer circumferential surface of the first cylindrical portion 10a of the duct 10. Also, a heater may be provided as the heating mechanism 60 instead of the absorbing material 61. Also, this heater may be installed inside the duct 10, for example.

[0089] 16, the server cooling system 100 may further include a solar panel 9. The solar panel 9 is provided on a side surface 10c of the outer circumferential surface of the duct 10, the side surface 10c facing away from the side wall 1a of the server room 1. The solar panel 9 converts sunlight irradiated from outside the duct 10 into electricity, and supplies the electricity to the fan 3.

[0090] This allows the server cooling system 100 to cover at least a portion of the power required to operate the fans 3 through solar power generation.

[0091] Moreover, the side surface 10c of the duct 10 on which the solar panel 9 is installed may be curved as shown in Fig. 15. In this case, the surface area of ​​the solar panel 9 increases, so that the amount of power generated by the solar panel 9 can be increased. The location of the solar panel 9 can be changed as appropriate. For example, the solar panel 9 may be provided on the entire outer periphery of the first cylindrical portion 10a of the duct 10.

[0092] The above-mentioned heat insulating material 8, heating mechanism 60, and solar panel 9 can be applied not only to the server cooling system 100 of the first embodiment, but also to the server cooling systems 200, 300 of the second and third embodiments.

[0093] In the above embodiments, the server cooling systems 100, 200, and 300 are described as including the damper 30. However, the present invention is not limited to this. The server cooling systems 100, 200, and 300 do not necessarily have to include the damper 30.

[0094] (Hardware configuration) The control device 40 in each of the above-described embodiments and modifications is implemented in a computer 1100 shown in Fig. 17. The computer 1100 includes a processor 1110, a main memory 1120, a storage 1130, and an interface 1140.

[0095] The operations of the above-mentioned processing units of the control device 40 are stored in the storage 1130 in the form of a program. The processor 1110 reads the program from the storage 1130, loads it in the main memory 1120, and executes the above-mentioned processing in accordance with the program. The processor 1110 also secures storage areas in the main memory 1120 corresponding to the above-mentioned storage units in accordance with the program.

[0096] The program may be for realizing a part of the functions to be performed by the computer 1100. For example, the program may be for realizing the functions by combining with other programs already stored in the storage 1130 or by combining with other programs implemented in other devices. The computer 1100 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to the above configuration or instead of the above configuration. Examples of PLDs include a PAL (Programmable Array Logic), a GAL (Generic Array Logic), a CPLD (Complex Programmable Logic Device), and an FPGA (Field Programmable Gate Array). In this case, a part or all of the functions to be realized by the processor 1110 may be realized by the integrated circuit.

[0097] Examples of storage 1130 include a magnetic disk, a magneto-optical disk, and a semiconductor memory. Storage 1130 may be an internal medium directly connected to the bus of computer 1100, or an external medium connected to computer 1100 via interface 1140 or a communication line. In addition, when this program is distributed to computer 1100 via a communication line, computer 1100 that receives the program may load the program in main memory 1120 and execute the above-mentioned processing. Storage 1130 may be a non-transitory tangible storage medium.

[0098] Furthermore, the program may be for realizing a part of the above-mentioned functions. Furthermore, the program may be a so-called difference file (difference program) that realizes the above-mentioned functions in combination with another program already stored in the storage 1130.

[0099] <Additional Notes> The server cooling systems 100, 200, and 300 described in the respective embodiments can be understood, for example, as follows.

[0100] (1) The server cooling system 100, 300 according to the first embodiment includes a duct 10 having a cylindrical shape extending in the vertical direction Dv and having an air exhaust port 11 formed at the upper part, an exhaust inlet section 20 for introducing exhaust air from a server room 1 into a portion of the duct 10 below the air exhaust port 11, a fan 3 provided in the duct 10 and driven to rotate so that air is exhausted from the air exhaust port 11, and a control device 40, wherein the control device 40 has a fan operating section 43 for rotating the fan 3 from a stopped state when the exhaust air is introduced into the duct 10, and a fan stopping section 44 for stopping the fan 3 when a natural circulation condition is satisfied after the fan 3 has rotated.

[0101] According to the above configuration, when high-temperature exhaust air from the server room 1 is introduced into the duct 10, the control device 40 rotates the fan 3 that is in a stopped state. Since high-temperature exhaust air from the server room 1 is supplied into the duct 10, the temperature inside the duct 10 becomes higher than the temperature outside the duct 10. This generates an upward flow in the duct 10. This upward flow draws the air in the server room 1 into the duct 10. This phenomenon is called the chimney effect. Immediately after the start of exhaust, the exhaust flow rate due to the chimney effect is small, but the fan 3 forcibly supplies a large amount of high-temperature exhaust air into the duct 10. This causes the temperature of the duct 10 to rise rapidly, and the exhaust flow rate due to the chimney effect increases. After that, the server room 1 is sufficiently exhausted only by the exhaust flow rate due to the chimney effect. The condition under which this state occurs is called the natural circulation condition. In this embodiment, when this natural circulation condition is satisfied, the control device 40 stops the fan 3. This allows the high-temperature air in the server room 1 to be sufficiently exhausted only by the chimney effect, and the server room 1 is sufficiently cooled.

[0102] (2) The server cooling system 100, 300 of the second aspect may be the server cooling system 100, 300 of the first aspect, further comprising a first earthquake-resistant member 6 provided at the connection between the exhaust inlet 20 and the server room 1 and capable of absorbing vibrations.

[0103] This allows the first earthquake-resistant member 6 to absorb vibrations transmitted to the duct 10 when an earthquake occurs, for example.

[0104] (3) The server cooling system 300 of the third aspect is the server cooling system 300 of the first or second aspect, and further includes a refrigerant inlet section 50 below the air exhaust port 11 in the duct 10 for introducing circulating refrigerant R from the server room 1, the refrigerant inlet section 50 having a heat exchange section 51 disposed within the duct 10 for performing heat exchange between the circulating refrigerant R and the air within the duct 10, and the fan operating section 43 may rotate the fan 3 from a stopped state when the exhaust air is introduced into the duct 10 and the circulating refrigerant R is introduced into the duct 10.

[0105] As a result, the circulating refrigerant R is supplied into the duct 10 while collecting heat from within the server room 1. The circulating refrigerant R supplied into the duct 10 supplies heat to the air within the duct 10 via the heat exchanger 51. This heat further heats the air within the duct 10, increasing the exhaust flow rate due to the chimney effect.

[0106] (4) A server cooling system 200 according to a fourth aspect includes a duct 10 having a cylindrical shape extending in a vertical direction Dv, an air inlet 13 formed at a lower part and an air outlet 11 formed at an upper part, a refrigerant introduction section 50 for introducing a circulating refrigerant R from a server room 1 between the air inlet 13 and the air outlet 11 in the duct 10, a fan 3 provided in the duct 10 and driven to rotate so that air is discharged from the air outlet 11, and a control device 40, wherein the refrigerant introduction section 50 has a heat exchange section 51 disposed in the duct 10 for performing heat exchange between the circulating refrigerant R and the air in the duct 10, and the control device 40 has a fan operation section 43 for rotating the fan 3 from a stopped state when the circulating refrigerant R is introduced into the duct 10, and a fan stop section 44 for stopping the fan 3 when a natural circulation condition is satisfied after the fan 3 has rotated.

[0107] According to the above configuration, when high-temperature circulating refrigerant is introduced into the duct 10 from the server room 1, the control device 40 rotates the fan 3 that is in a stopped state. The circulating refrigerant R is supplied into the duct 10 after collecting heat from within the server room 1. The refrigerant supplied into the duct 10 supplies heat to the air in the duct 10 by the heat exchanger 51. The air in the duct 10 is heated by this heat, and the air in the duct 10 becomes hotter than the air outside the duct 10. This generates an upward flow in the duct 10. This upward flow draws the air in the server room 1 into the duct 10 (chimney effect). Immediately after the start of exhaust, the exhaust flow rate due to the chimney effect is small, but the heat of the circulating refrigerant R heats the inside of the duct 10, and the temperature of the duct 10 rises rapidly. This increases the exhaust flow rate due to the chimney effect. After that, the air is sufficiently exhausted from the inside of the duct 10 only by the exhaust flow rate due to the chimney effect, and the natural circulation condition is satisfied. In this embodiment, when this natural circulation condition is satisfied, the control device 40 stops the fan 3. This allows the air in the duct 10 to be sufficiently exhausted only by the chimney effect. Therefore, heat exchange between the circulating refrigerant R and the air is efficiently performed, and the inside of the server room 1 can be sufficiently cooled by the air flowing through the duct 10 via the circulating refrigerant R.

[0108] (5) The server cooling system 200, 300 of a fifth aspect is the server cooling system 200, 300 of the third or fourth aspect, wherein the refrigerant introduction section 50 may further have fins 57 provided on an outer surface of the heat exchange section 51.

[0109] As a result, the fins 57 increase the surface area of ​​the heat exchange section 51. Therefore, the heat exchange efficiency of the heat exchange section 51 is improved.

[0110] (6) The server cooling system 200, 300 of a sixth aspect may be any one of the server cooling systems 200, 300 of the third to fifth aspects, and may further include a second earthquake-resistant member 7 provided at the connection between the refrigerant introduction part 50 and the server room 1 and capable of absorbing vibrations.

[0111] This allows the second earthquake-resistant member 7 to absorb vibrations transmitted to the duct 10 when an earthquake occurs, for example.

[0112] (7) A seventh aspect of the server cooling system 100, 200, 300 is any one of the server cooling systems 100, 200, 300 of the first to sixth aspects, further comprising a temperature sensor 4 for detecting the temperature in the duct 10, and the control device 40 has a judgment unit 42 for judging whether the natural circulation condition is satisfied, and the judgment unit 42 may judge that the natural circulation condition is satisfied when the temperature detected by the temperature sensor 4 exceeds a predetermined threshold value.

[0113] This enables the determination unit 42 to determine, from the temperature of the duct 10, whether or not the natural circulation condition is satisfied.

[0114] (8) The server cooling system 100, 200, 300 of an eighth aspect is the server cooling system 100, 200, 300 of any one of the first to sixth aspects, wherein the control device 40 has a judgment unit 42 that judges whether the natural circulation condition is satisfied, and the judgment unit 42 may determine that the natural circulation condition is satisfied when a predetermined time has elapsed since the fan 3 started to rotate.

[0115] This enables the determination unit 42 to determine whether or not the natural circulation condition is satisfied based on the time that has elapsed since the fan 3 started to rotate.

[0116] (9) A ninth aspect of the server cooling system 100, 200, 300 is the server cooling system 100, 200, 300 of any one of the first to eighth aspects, further comprising a damper 30 for opening and closing the air exhaust port 11, the duct 10 further comprising a fan exhaust port 12 provided separately from the air exhaust port 11 and having the fan 3 attached thereto, and the control device 40 further comprising a damper closing unit 45 for operating the damper 30 to close the air exhaust port 11 before the fan 3 starts to rotate, and a damper opening unit 46 for operating the damper 30 to open the air exhaust port 11 after the fan 3 has rotated.

[0117] As a result, when the fan 3 rotates, the server cooling system 100 can exhaust air from inside the duct 10 using the fan exhaust port 12 where the fan 3 is installed as the main exhaust port. Therefore, the server cooling system 100 can efficiently exhaust air using the fan 3. Furthermore, after the exhaust flow rate due to the chimney effect has increased sufficiently, the fan 3 is stopped and the air exhaust port 11 is opened to exhaust the air inside the duct 10 from both the fan exhaust port 12 and the air exhaust port 11. Therefore, when the fan 3 is stopped, the server cooling system 100 can increase the opening area of ​​the exhaust port to increase the exhaust flow rate.

[0118] (10) The server cooling system 100, 200, 300 of a tenth aspect is the server cooling system 100, 200, 300 of any one of the first to ninth aspects, and may further include a heat insulating material 8 provided in the duct 10.

[0119] The heat insulating material 8 prevents the air inside the duct 10 from releasing heat to the outside of the duct 10. This prevents the temperature of the air inside the duct 10 from decreasing.

[0120] (11) The server cooling system 100, 200, 300 of an eleventh aspect may be any one of the server cooling systems 100, 200, 300 of the first to tenth aspects, and may further include a heating mechanism 60 provided in the duct 10 to heat the air in the duct 10.

[0121] The heating mechanism 60 heats the air in the duct 10. This prevents the temperature of the air in the duct 10 from decreasing.

[0122] (12) A server cooling system 100, 200, 300 according to a twelfth aspect is a server cooling system 100, 200, 300 according to any one of the first to eleventh aspects, further comprising a solar panel 9 provided in the duct 10 for converting sunlight irradiated from outside the duct 10 into electricity, and the solar panel 9 may supply electricity to the fan 3.

[0123] This allows the server cooling system 100 to cover at least a portion of the power required to operate the fans 3 through solar power generation. [Explanation of symbols]

[0124] 1...Server room 1a...Side wall 1b...Air intake 1c...Exhaust 2...Server 3...Fan 4...Temperature sensor 5...Display 6...First earthquake-resistant member 7...Second earthquake-resistant member 8...Insulating material 9...Solar panel 10...Duct 10a...First cylindrical portion 10b...Second cylindrical portion 10c...Side 11...Air exhaust port 12...Fan exhaust port 13...Air inlet 20...Exhaust inlet 30...Damper 40...Control device 41...Acquisition unit 42...Determination unit 43...Fan operation unit 44...Fan stop unit 45...Damper closing unit 46...Damper opening unit 47...Refrigerant operation unit 50...Refrigerant introduction unit 51...Heat exchange unit 52...Refrigerant supply pipe 53...Refrigerant discharge pipe 54...Supply side header 55...Discharge side header 56...Connecting pipe 57...Fin 60...Heating mechanism 61...absorbent material 100...server cooling system 200...server cooling system 300...server cooling system 1100...computer 1110...processor 1120...main memory 1130...storage 1140...interface Dv...vertical direction

Claims

1. A duct having a cylindrical shape extending in the vertical direction and an air exhaust port formed at an upper portion thereof; an exhaust inlet portion that introduces exhaust air from a server room into a portion of the duct below the air exhaust port; a fan provided in the duct and driven to rotate so as to exhaust air from the air exhaust port; A control device; Equipped with The control device includes: a fan operating unit that rotates the fan from a stopped state when the exhaust air is introduced into the duct; a fan stopping unit that stops the fan when a natural circulation condition is satisfied after the fan rotates; A server cooling system having:

2. The server cooling system according to claim 1 , further comprising a first earthquake-resistant member provided at a connection between the exhaust gas inlet and the server room and capable of absorbing vibrations.

3. a refrigerant introduction section for introducing a circulating refrigerant from the server room, the duct being disposed below the air exhaust port; the refrigerant introduction section has a heat exchange section disposed in the duct to perform heat exchange between the circulating refrigerant and the air in the duct, The server cooling system according to claim 1 , wherein the fan operating unit rotates the fan from a stopped state when the exhaust air is introduced into the duct and the circulating refrigerant is introduced into the duct.

4. a duct having a cylindrical shape extending in the vertical direction, an air inlet formed at a lower portion, and an air exhaust port formed at an upper portion; a refrigerant introduction section for introducing a circulating refrigerant from a server room between the air inlet and the air outlet in the duct; a fan provided in the duct and driven to rotate so as to exhaust air from the air exhaust port; A control device; Equipped with the refrigerant introduction section has a heat exchange section disposed in the duct to perform heat exchange between the circulating refrigerant and the air in the duct, The control device includes: a fan operating unit that rotates the fan from a stopped state when the circulating refrigerant is introduced into the duct; a fan stopping unit that stops the fan when a natural circulation condition is satisfied after the fan rotates; A server cooling system having:

5. 5. The server cooling system according to claim 3, wherein the coolant introduction section further comprises fins provided on an outer surface of the heat exchange section.

6. 5. The server cooling system according to claim 3, further comprising a second earthquake-resistant member provided at a connection between the coolant introduction section and the server room and capable of absorbing vibrations.

7. A temperature sensor for detecting a temperature inside the duct is further provided. The control device includes: a determination unit that determines whether the natural circulation condition is satisfied, 5. The server cooling system according to claim 1, wherein the determination unit determines that the natural circulation condition is satisfied when the temperature detected by the temperature sensor exceeds a predetermined threshold value.

8. The control device includes: a determination unit that determines whether the natural circulation condition is satisfied, 5. The server cooling system according to claim 1, wherein the determining unit determines that the natural circulation condition is satisfied when a predetermined time has elapsed since the fan started to rotate.

9. Further comprising a damper for opening and closing the air exhaust port, The duct further includes a fan exhaust port provided separately from the air exhaust port and to which the fan is attached, The control device includes: a damper closing unit that operates the damper to close the air exhaust port before the fan starts to rotate; a damper opening unit that operates the damper to open the air exhaust port after the fan rotates; The server cooling system according to claim 1 , further comprising:

10. The server cooling system according to claim 1 , further comprising a heat insulating material provided in the duct.

11. The server cooling system according to claim 1 , further comprising a heating mechanism provided in the duct for heating air within the duct.

12. The solar panel is provided in the duct and converts sunlight irradiated from outside the duct into electricity. The server cooling system according to claim 1 , wherein the solar panel supplies power to the fan.

Images