Cooling system

Abstract

To provide a cooling system which achieves a redundancy equivalent to a redundancy achieved when normal coil units are doubled while saving a space.SOLUTION: A cooling system for cooling a server room R includes a coil unit 50 which supplies cooling air A to the server room. The coil unit includes a first system coil 1 and a second system coil 2 which may be operated independently of each other. When one of the first system coil and the second system coil is operated, the other is stopped.SELECTED DRAWING: Figure 2

Description

Technical Field

[0004] ,

[0005] ,

[0001] The present disclosure relates to a cooling system, and more particularly to a cooling system for cooling a server room.

Background Art

[0002] In a server room in a data center or the like, a large number of servers are installed. When these servers are operating, heat is generated, and the temperature in the server room becomes high. Therefore, the server room is cooled by a cooling system to prevent the servers from failing due to heat.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, a cooling system includes one or more coil units that supply cooling air to a server room. Usually, a coil unit includes one coil. Here, if one of the plurality of coil units fails, the ability to cool the server room is insufficient, and there is a risk that the servers may fail due to heat. Since there is a risk that sufficient service cannot be provided to clients if the servers fail, it is fatal for a server system. Therefore, (N + M) coil units are installed, where N is the predetermined required number corresponding to the maximum heat generation amount of the servers (N is a natural number) and M is a spare number (M is a natural number), so that even if any one of the coil units fails, the spare coil unit can be operated during the repair to always ensure the necessary cooling performance. In this way, installing more units than the required number is called redundancy or redundancy implementation.

[0005] Typically, the number of spare coil units (M units) is less than the required number (N units). However, recently, in order to strengthen the backup system, there is consideration to making the number of spare coil units (M units) equal to the required number (N units), that is, to install a total of twice the number of coil units, or (2 × N) units.

[0006] However, installing this many coil units doubles the installation space required for the coil units. Therefore, more installation space is needed than usual, and doubling the number of units becomes impossible if there is not enough surplus space.

[0007] Therefore, this disclosure was conceived in view of these circumstances, and its purpose is to provide a cooling system that can achieve the same level of redundancy as when doubling a normal coil unit, while saving space. [Means for solving the problem]

[0008] According to one aspect of this disclosure, A cooling system for cooling a server room, The server room is equipped with a coil unit that supplies cooling air, The coil unit comprises a first system coil and a second system coil that can operate independently of each other. When either the first coil system or the second coil system is operating, the other is stopped. A cooling system characterized by the above is provided.

[0009] Preferably, the first coil system and the second coil system have equal capacity.

[0010] Preferably, the first system coil and the second system coil are each formed by a single coil.

[0011] Preferably, at least one of the first coil system and the second coil system is formed by a plurality of coils.

[0012] Preferably, the coil unit has a spare space for installing an additional coil.

[0013] Preferably, the first coil system and the second coil system are arranged in series.

[0014] Preferably, the first coil system and the second coil system are arranged in parallel.

[0015] Preferably, the coil unit includes a plurality of fans for blowing air cooled by the first coil system or the second coil system into the server room. The number of fans is one more than the number of fans required to match the maximum heat generation of the servers in the server room.

[0016] According to other aspects of this disclosure, A cooling method for supplying cooling air from a coil unit to a server room to cool the server room, The coil unit comprises a first system coil and a second system coil that can operate independently of each other. The cooling method includes a step of stopping the first coil system and the second coil system while one of them is operating. A cooling method characterized by the above is provided. [Effects of the Invention]

[0017] According to this disclosure, redundancy equivalent to that achieved by doubling a normal coil unit can be realized in a space-saving manner. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram showing the overall cooling system according to the first embodiment of this disclosure. [Figure 2] This is a schematic side cross-sectional view of the coil unit. [Figure 3] This is a schematic plan cross-sectional view of the first coil system and the second coil system. [Figure 4] It is a table showing the operating states of the pump and the valve during the operation of the first system coil and the second system coil. [Figure 5] It is a time chart showing a first example of the operating method of the first system coil and the second system coil. [Figure 6] It is a time chart showing a second example of the operating method of the first system coil and the second system coil. [Figure 7] It is a schematic side cross-sectional view showing a coil unit when an additional coil is installed. [Figure 8] It is a schematic side cross-sectional view of a coil unit according to the second embodiment. [Figure 9] It is a schematic plan cross-sectional view of a coil unit according to the second embodiment. [Figure 10] It is a schematic side cross-sectional view of a coil unit according to the third embodiment.

Mode for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that it should be noted that the present disclosure is not limited to the following embodiments.

[0020] [First Embodiment] FIG. 1 schematically shows the entirety of the cooling system of the first embodiment. The cooling system 100 is a system for cooling the server room R, and includes a coil unit 10 that supplies cooling air A to the server room R. The coil unit 10 includes a first system coil 1 and a second system coil 2 that can operate independently of each other. That is, one feature is that two systems of coils, namely the first system coil 1 and the second system coil 2, are provided in one coil unit 10.

[0021] Although only one is shown in the figure, the cooling system 100 includes a plurality of coil units 10 arranged in parallel. The flow of air A is indicated by a white arrow, and the flow of cold water (or coolant) W is indicated by a solid arrow.

[0022] The server room R is located in a room S inside a building Z, such as a building. The walls of the server room R are located inward from the outer wall of building Z, so as not to be exposed to the outside air. Multiple server racks 3 are installed in the server room R, and multiple servers (not shown) are installed in each of these server racks 3.

[0023] The coil unit 10 is adjacent to the server room R and supplies air A, cooled by heat exchange with chilled water W, into the server room R. The first coil system 1 and the second coil system 2, which act as water-cooled coils, are responsible for the heat exchange between air A and chilled water W.

[0024] The cooling system 100 includes a chilled water circulation device 4 for circulating chilled water W to the first coil 1 and the second coil 2 of the coil unit 10. The chilled water circulation device 4 includes a plurality of chillers 5 that produce chilled water W, a supply circuit 6 that supplies the chilled water W produced by the chillers 5 to the first coil 1 and the second coil 2, and a recirculation circuit 7 that returns the chilled water W, which has been heated by heat exchange with air A, back to the chillers 5.

[0025] As is well known, the chiller 5 is a device that uses a refrigerator to cool the chilled water W that has been returned. In this embodiment, a first chiller group 8 and a second chiller group 9 are provided, each containing five chillers 5 arranged in parallel. This ensures that even if a chiller 5 in one chiller group fails, the chilled water W can still be supplied by the other chiller group, thereby strengthening the backup system. In this embodiment, the first chiller group 8 and the second chiller group 9 are installed on the roof of building Z, and the chillers 5 are air-cooled. However, the first chiller group 8 and the second chiller group 9 may be installed in different locations inside or outside building Z, and the chillers 5 may be water-cooled.

[0026] The supply circuit 6 has a first supply pipe 11 that is commonly connected to the outlets of each chiller 5 in the first chiller group 8, and a second supply pipe 12 that is commonly connected to the outlets of each chiller 5 in the second chiller group 9. The downstream sides of these first supply pipes 11 and 2 supply pipes 12 are branched into two systems. That is, at the branching point 13, the upstream end of the first system supply pipe 14 is connected to the first supply pipe 11, and the downstream end of the first system supply pipe 14 is connected to the inlet 15 of the first system coil 1.

[0027] Furthermore, at branching point 13, the upstream end of the second system supply pipe 16 is connected to the first supply pipe 11, and the downstream end of the second system supply pipe 16 is connected to the inlet 17 of the second system coil 2.

[0028] On the other hand, at branching point 18, the upstream end of the first system connecting pipe 19 is connected to the second supply pipe 12, and the downstream end of the first system connecting pipe 19 is connected to the first system supply pipe 14 at confluence point 20.

[0029] Furthermore, at branching point 18, the upstream end of the second system connecting pipe 21 is connected to the second supply pipe 12, and the downstream end of the second system connecting pipe 21 is connected to the second system supply pipe 16 at confluence point 22.

[0030] A first system pump 23 is provided in the first system supply pipe 14 located downstream of the confluence point 20 to send chilled water W produced by the chiller 5 to the inlet 15 of the first system coil 1. Furthermore, a second system pump 24 is provided in the second system supply pipe 16 located downstream of the confluence point 22 to send chilled water W produced by the chiller 5 to the inlet 17 of the second system coil 1.

[0031] A first system valve 25 for opening and closing the pipeline is provided in the first system supply pipe 14 located downstream of the branching point 13 and upstream of the confluence point 20. Additionally, a first system connecting valve 26 is provided in the first system connecting pipe 14.

[0032] On the other hand, a second system valve 27 is provided in the second system supply pipe 16 located downstream of the branching point 13 and upstream of the confluence point 22. Furthermore, a second system connecting valve 28 is provided in the second system connecting pipe 21.

[0033] A configuration similar to that of the supply circuit 6 is also used in the recirculation circuit 7.

[0034] In other words, the recirculation circuit 7 has a first recirculation pipe 31 that is commonly connected to the inlet of each chiller 5 in the first chiller group 8, and a second recirculation pipe 32 that is commonly connected to the inlet of each chiller 5 in the second chiller group 9. The upstream sides of these first recirculation pipes 31 and 2nd recirculation pipes 32 are branched into two systems. That is, at the confluence point 33, the downstream end of the first system recirculation pipe 34 is connected to the first recirculation pipe 31, and the upstream end of the first system recirculation pipe 34 is connected to the outlet 35 of the first system coil 1.

[0035] Furthermore, at the confluence point 33, the downstream end of the second system return pipe 36 is connected to the first return pipe 31, and the upstream end of the second system return pipe 36 is connected to the outlet 37 of the second system coil 2.

[0036] On the other hand, at the confluence point 38, the downstream end of the second system connecting return pipe 39 is connected to the second return pipe 32, and the upstream end of the second system connecting return pipe 39 is connected to the second system return pipe 36 at the branching point 40.

[0037] Furthermore, at the confluence point 38, the downstream end of the first system connecting return pipe 41 is connected to the second return pipe 32, and the upstream end of the first system connecting return pipe 41 is connected to the first system return pipe 34 at the branching point 42.

[0038] A second system return valve 45 is provided in the second system return pipe 36 located upstream of the confluence point 33 and downstream of the branching point 40. Furthermore, a second system connecting return valve 46 is provided in the second system connecting return pipe 39.

[0039] On the other hand, a first system recirculation valve 47 is provided in the first system recirculation pipe 34 located upstream of the confluence point 33 and downstream of the branching point 42. Furthermore, a first system connecting recirculation valve 48 is provided in the first system connecting recirculation pipe 41.

[0040] Next, the coil unit 10 will be described with reference to Figures 2 and 3. The front, back, left, right, up, and down directions of the coil unit 10 are as shown in the figures. The front of the coil unit 10 is adjacent to the server room R, and cooling air A is blown into the server room R from the front.

[0041] The coil unit 10 comprises a rectangular parallelepiped casing 50, a first system coil 1, a second system coil 2, a filter 51, and a fan 52 housed within the casing 50.

[0042] The first system coil 1 and the second system coil 2 are each formed by a single coil. Furthermore, the first system coil 1 and the second system coil 2 are identical to each other and have the same capacity (cooling capacity). Therefore, only the first system coil 1 will be described as a representative example, and the description of the second system coil 2 will be omitted.

[0043] The first coil system 1 is formed from a general chilled water coil and has a width B in the left-right direction, a thickness T in the front-back direction, and a height H in the up-down direction. When viewed as a whole, the first coil system 1 has a roughly flat panel-like rectangular parallelepiped shape, and when viewed from the front, it has a rectangular shape, with a thickness T smaller than the width B and height H.

[0044] The first coil system 1 comprises the aforementioned inlet 15 and outlet 35, an inlet header 53 and an outlet header 54 connected to the inlet 15 and outlet 35, a bent tube 55 connecting the inlet header 53 and outlet header 54 to each other, fins (not shown) fixed to the bent tube 55, and a coil case 56 that houses and secures the bent tube 55 and fins.

[0045] The inlet 15 and outlet 35 are located at the lower and upper ends of the right sides of the inlet header 53 and outlet header 54, respectively, which extend in the height direction. Multiple bent tubes 55 are provided in the height direction, each bending in an S-shape as shown in Figure 3, from the inlet header 53 to the outlet header 54. The coil case 56 covers most of the bent tubes 55, excluding the folded-over portions at both the left and right ends. The coil case 56 is a rectangular tube shape that extends in the front-to-back direction with its front and rear ends open.

[0046] Chilled water W is introduced from the first system supply pipe 14 to the inlet 15, and then, after passing through the inlet header 53, the bent tube 55, and the outlet header 54, is discharged from the outlet 35 to the first system return pipe 34. Meanwhile, air A from room S is introduced into the coil case 56 from the rear end opening (air inlet surface) of the coil case 56. As the air A flows forward in the thickness T direction within the coil case 56, heat exchange occurs between the chilled water W flowing through the bent tube 55 and the air A, and the air A is cooled by the chilled water W. After cooling, the air A is discharged from the front end opening (air outlet surface) of the coil case 56, passes through the coil case 56 of the second system coil 2, and is then supplied into the server room R.

[0047] Here, the first coil 1 and the second coil 2 are arranged in series. In this context, "in series" means that the first coil 1 and the second coil 2 are aligned in the thickness T direction (i.e., the direction of air A flow through the coils), and the air A that passes through one coil is introduced directly into the other coil in a straight line (without bending). The direction of air A flow through one coil and the direction of air A flow through the other coil are parallel and in the same direction.

[0048] In this embodiment, the first coil 1 is positioned close to or adjacent to the second coil 2 on the upstream side in the direction of air A flow. Furthermore, the first coil 1 and the second coil 2 are arranged in a complete overlap state, where they completely overlap when viewed from the front. However, the first coil 1 and the second coil 2 may also be arranged in a partial overlap state, where they partially overlap when viewed from the front. In the overlapping portion, the air A that has passed through one coil continues to pass linearly through the other coil, so this partial overlap state is also a form of series arrangement.

[0049] Fan 52 is an electric fan located a predetermined distance in front of the second coil 2, and discharges air A drawn in from the rear toward the front. In this embodiment, multiple fans 52 are provided, specifically a total of six fans arranged in two rows vertically and three columns horizontally. However, the number and arrangement of fans 52 are arbitrary.

[0050] The filter 51 is for removing dust from the air. In this embodiment, the filter 51 is located directly upstream of the air inlet surface of the first coil 1, and is configured to remove dust just before the air A is drawn into the first coil 1. However, the position of the filter 51 is arbitrary; for example, it may be located downstream of the fan 52 to remove dust just before the cooling air A is blown into the server room R.

[0051] Although not shown in the diagram, the rear end surface of the casing 50 is provided with an opening (air inlet) for introducing air A, and the front end surface of the casing 50 is provided with an opening (air outlet) for discharging air A. Except for these openings, the casing 50 is sealed.

[0052] In this embodiment, the coil unit 10 has a spare space 61 within the casing 50 for installing an additional coil 60. The role of this additional coil 60 will be described in detail later. The spare space 61 is formed between the second system coil 2 and the fan 52, and allows an additional coil 60 identical (in particular, of the same capacity) to the first system coil 1 and the second system coil 2 to be placed in series with the second system coil 2, just as with the first system coil 1 and the second system coil 2.

[0053] In this embodiment, the number of coils required to correspond to the maximum heat generation of the servers in server room R is N (where N is a natural number). Furthermore, in order to strengthen the backup system, it is necessary to provide an equal number of spare coils (M) to the required number (N), so that the total number of coils is (2 × N).

[0054] Therefore, in this embodiment, a single coil unit 10 is provided with a first system coil 1 and a second system coil 2 that can operate independently of each other. When one of the first system coil 1 or the second system coil 2 is operating, the other is stopped. In other words, while one is operating, the other is merely a backup or reserve unit and is always stopped. This strengthens the backup system.

[0055] More specifically, the first system coil 1 and the second system coil 2 are separate coils, and either one can be activated or both can be activated simultaneously. However, in this embodiment, when the coil unit 10 is activated, only one of the coils is always activated, and the other coil, being redundant, is stopped. This provides redundancy.

[0056] In this embodiment, one coil unit 10 is provided with two coils, a first system coil 1 and a second system coil 2. Since N such coil units 10 are installed, the total number of coils is (2 × N), satisfying the above requirement regarding the number of coils.

[0057] Furthermore, since one coil unit 10 is equipped with two coils, the installation space required can be reduced by nearly half compared to installing (2 × N) conventional coil units, each equipped with only one coil. If the latter installation space is considered 100%, then in this embodiment, the installation space can be reduced to, for example, about 60%. Therefore, the same level of redundancy as when doubling conventional coil units can be achieved in a space-saving manner.

[0058] Figure 4 shows the operating states of pumps 23, 24 and valves 25-28, 45-48 when one of the first coil system 1 and the second coil system 2 is operating and the other is stopped. For pumps 23 and 24, ○ means on and × means off. For valves 25-28, 45-48, ○ means open and × means closed.

[0059] When the coil unit 10 is operating, for example, when the first coil 1 is operating and the second coil 2 is stopped (when only the first coil 1 is operating), pump 23 is turned ON (operating) and pump 24 is turned OFF (stopped). Also, valves 25, 26, 47, and 48 are opened, and valves 27, 28, 45, and 46 are closed.

[0060] As shown in Figure 1, the chilled water W from each chiller 5 flows only to the first system side of the supply circuit 6 and the recirculation circuit 7, and no longer flows to the second system side. It is then supplied only to the first system coil 1, and no longer to the second system coil 2. The state in which the coil is supplied with chilled water W is called the operating state, and the state in which the coil is not supplied with chilled water W is called the stopped state.

[0061] At this time, chilled water W supplied from each chiller 5 of the first chiller group 8 is supplied to the inlet 15 of the first system coil 1 through the first supply pipe 11 and the first system supply pipe 14 in sequence. Chilled water W supplied from each chiller 5 of the second chiller group 9 is supplied to the inlet 15 of the first system coil 1 through the second supply pipe 12, the first system connecting pipe 19 and the first system supply pipe 14 in sequence.

[0062] Meanwhile, the chilled water W, after heating and discharged from the outlet 35 of the first coil 1, is returned to each chiller 5 of the first chiller group 8 by passing through the first circulation pipe 34 and the first circulation pipe 31 in sequence, and also returned to each chiller 5 of the second chiller group 9 by passing through the first circulation pipe 34 and the second circulation pipe 32 in sequence.

[0063] This example shows a scenario where chilled water W is supplied from both the first chiller group 8 and the second chiller group 9, but it is also possible to supply chilled water W from only one of the chiller groups. In this case, the closed state of the valve is shown in Figure 4 with an (×).

[0064] For example, when only the first coil 1 is operating and chilled water W is supplied only from the first chiller group 8, pump 23 is turned on, pump 24 is turned off, valves 25 and 47 are opened, and valves 26, 27, 28, 45, 46, and 48 are closed.

[0065] As shown in Figure 1, the chilled water W supplied from each chiller 5 of the first chiller group 8 is supplied to the inlet 15 of the first system coil 1 via the first supply pipe 11 and the first system supply pipe 14 in the same manner as described above. However, the route from each chiller 5 of the second chiller group 9 to the inlet 15 of the first system coil 1 is blocked.

[0066] On the other hand, the chilled water W, after heating, discharged from the outlet 35 of the first coil 1 is returned to each chiller 5 of the first chiller group 8 by passing through the first circulation pipe 34 and the first circulation pipe 31 in sequence, as described above. However, the route from the outlet 35 of the first coil 1 to each chiller 5 of the second chiller group 9 is blocked.

[0067] The case where chilled water W is supplied only from the second chiller group 9 is clear from the above explanation and Figure 4, so the explanation will be omitted.

[0068] Furthermore, the situation when the second coil 2 is operating and the first coil 1 is stopped (when only the second coil 2 is operating) is clear from the above explanation and Figure 4, so the explanation will be omitted.

[0069] As shown in Figures 2 and 3, when the coil unit 10 is operating, the fan 52 is activated, generating a flow of air A (wind or airflow) that passes through the casing 50 from rear to front. At this time, the air A in the room S is introduced into the casing 50 through the rear end opening of the casing 50 and purified through the filter 51. It then passes through the first coil system 1 and the second coil system 2 in order, then through the spare space 61 and the fan 52 in order, and is blown out into the server room R through the front end opening of the casing 50.

[0070] For example, if only the first coil 1 is operating, the air A is cooled as it passes through the first coil 1, and the cooled air A passes straight through the second coil and is finally blown into the server room R. On the other hand, if only the second coil 2 is operating, the uncooled air A that has passed straight through the first coil 1 is introduced into the second coil 2, cooled by the second coil 2, and then finally blown into the server room R.

[0071] In this embodiment, the number of fans 52 is also made redundant. That is, the number of fans 52 required to correspond to the maximum heat generation of the servers in the server room R is n (where n is a natural number, and in this embodiment n=5). However, in this embodiment, one spare fan 52 is provided for backup purposes, bringing the total number of fans 52 to (n+1).

[0072] There are several ways to use these redundant fans 52. For example, when all (n+1) fans 52 are functioning normally, all fans 52 can be operated at a capacity of n / (n+1) or less of their maximum capacity. If one fan 52 fails, while it is being repaired, the remaining n functioning fans 52 can be operated at a capacity of less than or equal to their maximum capacity.

[0073] Alternatively, when all fans 52 are functioning normally, the n fans 52 are operated at or below their maximum capacity. If one fan 52 fails, while it is being repaired, the remaining n functioning fans 52 are operated at or below their maximum capacity.

[0074] Next, we will explain an example of how to operate the first coil system 1 and the second coil system 2. Figure 5 is a time chart showing the first example. In the figure, t1 to t7 indicate the start timing (e.g., time 0:00) of each period separated by a period τ (e.g., 24 hours). The first system coil 1 and the second system coil 2 are simply labeled "coil 1" and "coil 2," respectively, with hatching indicating the operating state and blank spaces indicating the stopped state.

[0075] In this first example, only the first coil 1 operates continuously over multiple cycles until it fails at point X. After the failure of the first coil 1 at point X, only the second coil 2 operates, during which time the first coil 1 is repaired or replaced.

[0076] On the other hand, Figure 6 shows a second example. In this example, at the start of each cycle, the operation of only the first coil 1 and the operation of only the second coil 2 are alternately switched. In the illustrated example, in the cycle starting at t5, only the first coil 1 was initially operating, but at point X, the first coil 1 failed, so from then on, only the second coil 2 operates. During this time, the first coil 1 is repaired or replaced.

[0077] This operating method ensures that even if one coil fails, the other coil can continue to operate, guaranteeing the necessary cooling performance at all times.

[0078] Incidentally, while using the coil unit 10, a change in the specifications of the servers in server room R may increase the server capacity, resulting in a situation where the existing coil unit 10 is insufficient for cooling.

[0079] Therefore, in this embodiment, the coil unit 10 is provided with a spare space 61 for installing an additional coil 60. This allows for the addition of an additional coil 60 to the coil unit 10 in the event of the above situation, making it possible to address the situation.

[0080] Figure 7 shows the coil unit 10 with the additional coil 60 actually installed in the spare space 61. As mentioned above, the additional coil 60 is identical to the first system coil 1 and the second system coil 2, and is arranged in series with the second system coil 2, just as with the first system coil 1 and the second system coil 2. The additional coil 60 is located downstream of the second system coil 2 in the direction of air A flow.

[0081] The upstream end of the first additional supply pipe 63 is connected to the branching point 62 of the first supply pipe 14, and the downstream end of the first additional supply pipe 63 is connected to the inlet 64 of the additional coil 60.

[0082] Furthermore, the upstream end of the second additional supply pipe 66 is connected to the branching point 65 of the second supply pipe 16, and the downstream end of the second additional supply pipe 66 is connected to the first additional supply pipe 63 at the confluence point 67.

[0083] On the other hand, the downstream end of the first additional return pipe 69 is connected to the confluence point 68 of the first return pipe 34, and the upstream end of the first additional return pipe 69 is connected to the outlet 70 of the additional coil 60.

[0084] Furthermore, the downstream end of the second additional return pipe 72 is connected to the confluence point 71 of the second return pipe 36, and the upstream end of the second additional return pipe 72 is connected to the first additional return pipe 69 at the branching point 73.

[0085] A first additional valve 74 is provided in the first additional supply pipe 63 located downstream of branching point 62 and upstream of confluence point 67. Furthermore, a second additional valve 75 is provided in the second additional supply pipe 66 located downstream of branching point 65 and upstream of confluence point 67.

[0086] On the other hand, a second system recirculation valve 76 is provided in the second system additional recirculation pipe 72 located upstream of the confluence point 71 and downstream of the branching point 73. Furthermore, a first system additional recirculation valve 77 is provided in the first system additional recirculation pipe 69 located upstream of the confluence point 68 and downstream of the branching point 73.

[0087] By switching these valves 74 to 77, chilled water W can be introduced to the inlet 64 of the additional coil 60 from either the first supply pipe 14 or the second supply pipe 16, and chilled water W can be discharged from the outlet 70 of the additional coil 60 to either the first return pipe 34 or the second return pipe 36.

[0088] The usage of this additional coil 60 will now be explained. Before the addition of the additional coil 60, only one of either the first system coil 1 or the second system coil 2 is operational. However, after the additional coil 60 is added due to the increase in server capacity, two of the first system coil 1, second system coil 2, and additional coil 60 will form a new first system coil, and one will form a new second system coil.

[0089] For example, if the combination of coil 1 and coil 2 of the first system is designated as the new first system coil, and the additional coil 60 is designated as the new second system coil, then only the new first system coil will be activated, and the additional coil 60 will be stopped. Since the new first system coil has twice the capacity of the original coil, it can handle an increase in server capacity.

[0090] In this case, it is preferable to operate either the first coil 1 or the second coil 2 when the server room R is relatively cold and under low load conditions, and to operate both when the server room R is relatively hot and under high load conditions.

[0091] On the other hand, if either the first coil 1 or the second coil 2, which make up the new first coil system, fails, the additional coil 60 is used in place of the failed one. This ensures that the necessary cooling capacity can be maintained even if one coil fails.

[0092] Since it is unlikely that two of the three coils will fail simultaneously, it is preferable to use only one additional coil 60 to minimize the size of the coil unit 10 and the space required for its installation.

[0093] The addition of the additional coil 60 may be done for all of the coil units 10, or for some of them. Similarly, the spare space 61 may be provided for all of the coil units 10, or for only some of them. Of course, a coil unit 10 without the spare space 61 is also possible.

[0094] [Second Embodiment] Next, a second embodiment of the present disclosure will be described. Parts identical to those in the first embodiment are denoted by the same reference numerals in the figures and their descriptions are omitted. The following description will primarily focus on the differences from the first embodiment.

[0095] In the first embodiment described above, as shown in Figure 2, the first system coil 1 and the second system coil 2 were arranged in series. In contrast, in this embodiment, as shown in Figures 8 and 9, the first system coil 1 and the second system coil 2 are arranged in parallel.

[0096] In this context, a parallel configuration refers to a configuration in which the first coil 1 and the second coil 2 are not aligned in the thickness T direction (i.e., the flow direction of air A passing through the coils), and air A passing through one coil is not introduced directly into the other coil in a straight line (without bending). In this embodiment, the flow direction of air A passing through one coil and the flow direction of air A passing through the other coil are non-parallel and in different directions.

[0097] In this embodiment, the first coil system 1 and the second coil system 2 are arranged along two different surfaces of the casing 50, with orientations that are 90° apart from each other.

[0098] The first coil system 1 is positioned at the rear end of the casing 50, along the rear end surface of the casing 50. The first coil system 1 is positioned such that its thickness T coincides with the front-to-back direction, its width B coincides with the left-to-right direction, and its height H coincides with the up-to-down direction. The first coil system 1 then allows air A to pass through from rear to front, as in the first embodiment.

[0099] The second coil system 2 is positioned at the right end of the casing 50, along the right side of the casing 50. The second coil system 1 is positioned such that its width B coincides with the front-to-back direction, its thickness T coincides with the left-to-right direction, and its height H coincides with the up-to-down direction. The second coil system 2 allows air A to pass through from right to left.

[0100] The second coil system 2 is positioned in front of the right end of the first coil system 1. The height H of the second coil system 2 is lower than the height H of the first coil system 1.

[0101] The rear end and right side of the casing 50, which faces the inlet surfaces (rear end and right side) of the first coil 1 and the second coil 2, are provided with openings (not shown) for allowing air A to pass through. Of these openings, those corresponding to the coil to be stopped are closed by openable / closable lids (not shown) to prevent air from flowing into that coil.

[0102] Furthermore, within the casing 50, a spare space 61 for installing an additional coil 60 is provided in front of the upper end of the first coil system 1, and above and to the left of the second coil system 2. If the additional coil 60 is installed in this spare space 61, the additional coil 60 will be positioned on its side such that its height H coincides with the front-to-back direction, its width B coincides with the left-to-right direction, and its thickness T coincides with the up-to-down direction. The additional coil 60 will then allow air A to pass through it from top to bottom.

[0103] In the illustrated example, with respect to the left-right direction, the width B of the additional coil 60 is smaller than the width B of the first system coil 1, and the sum of the width B of the additional coil 60 and the thickness T of the second system coil 2 is approximately equal to the width B of the first system coil 1. The position of the right side of the first system coil 1 is equal to the position of the right side of the second system coil 2, and the position of the left side of the first system coil 1 is equal to the position of the left side of the additional coil 60.

[0104] With respect to the front-to-back direction, the height H of the additional coil 60 is equal to the width B of the second coil system 2. The positions of the front and rear end faces of the additional coil 60 are equal to the positions of the front and rear end faces of the second coil system 2.

[0105] In the vertical direction, the sum of the thickness T of the additional coil 60 and the height H of the second system coil 2 is equal to the height H of the first system coil 1. The position of the upper end face of the additional coil 60 is equal to the position of the upper end face of the first system coil 1, and the position of the lower end face of the second system coil 2 is equal to the position of the lower end face of the first system coil 1.

[0106] The thickness T of the first coil 1, the second coil 2, and the additional coil 60 are equal. In this way, the three coils can be arranged compactly, contributing to space saving.

[0107] In the plan view (Figure 9), the area of ​​the spare space 61 is a space that extends the entire height of the casing 50. Here, the cooling air A discharged from the first coil system 1 travels in a straight line, while the cooling air A discharged from the second coil system 2 is bent forward. When the additional coil 60 is installed, the cooling air A discharged from the additional coil 60 is also bent forward.

[0108] Although their dimensions differ, the capabilities of the first system coil 1, the second system coil 2, and the additional coil 60 are identical.

[0109] Within the casing 50, multiple fans 52 (six in this embodiment) and filters 51 are provided in front of the second coil system 2 and the spare space 61, starting from the rear. In this embodiment, since the inlet surfaces of the first coil system 1 and the second coil system 2 face different surfaces of the casing 50, providing filters on the inlet side of each coil 1 and 2 would increase the number of filters and potentially increase costs. Therefore, in this embodiment, a common filter 51 is provided on the outlet side of each coil 1 and 2 to reduce the number of filters and suppress costs.

[0110] When the fan 52 is activated, air A inside room S is drawn into the casing 50. At this time, if only the first coil system 1 is operating, a flow of air A is created that passes through the first coil system 1 from rear to front, and the air A cooled by the first coil system 1 is blown out into the server room R at the front.

[0111] On the other hand, if only the second coil 2 is operating, a flow of air A is generated that passes through the second coil 2 from right to left. The air A cooled by the second coil 2 is then bent forward and blown out into the server room R.

[0112] Furthermore, when only the first coil 1 is operating, only the corresponding cover is opened, and when only the second coil 2 is operating, only the corresponding cover is opened.

[0113] On the other hand, before the addition of the additional coil 60, an opening (not shown) at the upper end surface of the casing 50, which is opposite the inlet surface (upper end surface) of the additional coil 60, is closed by a lid (not shown) that can be opened and closed. This lid is opened after the addition of the additional coil 60, when it is operating or in use. When the fan 52 is operated at this time, a flow of air A is generated that passes through the additional coil 60 from top to bottom, and the air A cooled by the additional coil 60 is bent forward and then blown out into the server room R.

[0114] In the first embodiment, when only one of the first coil 1 and the second coil 2 is operating, air A always passes through both coils, which can result in a relatively large pressure loss. However, in this embodiment, when only one is operating, air A can pass through only one coil and not the other, thus reducing the pressure loss.

[0115] There are various other possible arrangements for the first coil system 1, the second coil system 2, and the additional coil 60. For example, the second coil system 2 and the additional coil 60 may be arranged in the opposite direction from the illustrated example. At least two of the three coils may be arranged in parallel along any one surface of the casing 50. It is also possible to combine parallel and series arrangements. It is also possible to change the dimensions of at least one of the three coils. It is also possible to make all three coils the same size.

[0116] [Third Embodiment] Next, a third embodiment of this disclosure will be described.

[0117] As shown in Figure 10, this embodiment relates to an improvement on the coil unit 10 of the first embodiment. In the first embodiment, the first system coil 1 and the second system coil 2 were each formed by a single coil. However, in this embodiment, the first system coil 1 and the second system coil 2 are each formed by multiple coils. In other words, the first system coil 1 and the second system coil 2 are each divided into multiple coils. These divided coils are called the first system divided coil 1A and the second system divided coil 1B. The total capacity of the multiple first system divided coils 1A is equal to the capacity of the single first system coil 1 in the first embodiment. Similarly, the total capacity of the multiple second system divided coils 2A is equal to the capacity of the single second system coil 2 in the first embodiment.

[0118] In this embodiment, the first system coil 1 is divided into two equal parts vertically and formed by two identical first system division coils 1A arranged vertically. Similarly, the second system coil 2 is also divided into two equal parts vertically and formed by two identical second system division coils 2A arranged vertically.

[0119] Each divided coil 1A, 2A has inlets 15, 17 and outlets 35, 37. With respect to the first system, the upper and lower divided coils 1A are arranged in parallel. Here, "parallel arrangement" means that the inlets 15 of the upper and lower divided coils 1A are commonly connected to the first system supply pipe 14, and the outlets 35 of the upper and lower divided coils 1A are commonly connected to the first system return pipe 34.

[0120] However, the upper and lower split coils 1A may be arranged in series. Here, "series arrangement" means an arrangement in which one inlet 15 of the upper and lower split coils 1A is connected to the first system supply pipe 14, one outlet 35 is connected to the other inlet 15, and the other outlet 35 is connected to the first system return pipe 34.

[0121] The same applies to the second system, so I will omit the explanation.

[0122] In line with the above-mentioned division of the coil, the filter 51 and the additional coil 60 are also divided into two equal parts, upper and lower.

[0123] According to this embodiment, since the first system coil 1 and the second system coil 2 are each formed by multiple coils, the flexibility regarding the arrangement of coils is increased, and it may be possible to achieve even greater space savings. In addition, if either the first system coil 1 or the second system coil 2 fails, only the faulty split coil needs to be repaired or replaced, which may reduce running costs.

[0124] Furthermore, one of the first coil system 1 and the second coil system 2 may be formed from multiple coils. A partition plate may be provided between the upper coils and the lower coils to divide the space inside the casing 50 into upper and lower sections.

[0125] Although embodiments of this disclosure have been described in detail above, various other embodiments and modifications of this disclosure are conceivable.

[0126] (1) For example, the number of coil units 10 may be one. The number of chiller groups may also be one.

[0127] (2) In the first and third embodiments, a filter 51 may be provided downstream of the first coil 1 and the second coil 2 in the direction of air A flow, and a fan 52 may be provided upstream of the first coil 1 and the second coil 2 in the direction of air A flow.

[0128] The configurations of each embodiment and each variation described above can be combined in part or in whole, as long as there is no particular contradiction. The embodiments of this disclosure are not limited to those described above, but include any variations, applications, and equivalents that are encompassed within the spirit of this disclosure as defined by the claims. Therefore, this disclosure should not be constrained and may be applied to any other art that falls within the scope of the spirit of this disclosure. [Explanation of Symbols]

[0129] 1. First system coil 2. Second System Coil 1A First System Split Coil 2A Second System Split Coil 60 additional coils 61 Spare space 52 Fans 50 coil units 100 Cooling System A air R Server Room

Claims

1. A cooling system for cooling a server room, The server room is equipped with a coil unit that supplies cooling air, The coil unit comprises a casing and a first system coil and a second system coil housed within the casing and capable of operating independently of each other. When one of the first coil system and the second coil system is operating, the other is stopped. The first and second coil systems are not aligned in the direction of airflow through each coil, and are arranged in parallel such that air passing through one coil is not directly introduced linearly into the other coil. The first coil system and the second coil system are arranged such that the airflow directions passing through each coil are non-parallel and in different directions from each other. The first coil system and the second coil system are arranged along two different surfaces of the casing, in orientations that are 90° apart from each other. The first coil system is positioned along the rear end surface of the casing and allows air to pass from rear to front. The second coil system is arranged along one of the left or right sides of the casing, and allows air to pass from one side to the other. When only the first coil system is operating, the air that has passed through the first coil system travels straight through the casing and is blown out into the server room at the front. When only the second coil is operating, the air that has passed through the second coil is bent forward within the casing and then blown out into the server room at the front. A cooling system characterized by the following features.

2. The first system coil and the second system coil have equal capacity. The cooling system according to claim 1.

3. The first system coil and the second system coil are each formed by a single coil. The cooling system according to claim 1 or 2.

4. At least one of the first system coil and the second system coil is formed by a plurality of coils. The cooling system according to claim 1 or 2.

5. The coil unit has a spare space for installing additional coils. A cooling system according to any one of claims 1 to 4.

6. The coil unit includes a plurality of fans for blowing air cooled by the first coil system or the second coil system into the server room. The number of fans is one more than the number of fans required to handle the maximum heat generated by the servers in the server room. A cooling system according to any one of claims 1 to 5.

7. A cooling method for supplying cooling air from a coil unit to a server room to cool the server room, The coil unit comprises a casing and a first system coil and a second system coil housed within the casing and capable of operating independently of each other. The first and second coil systems are not aligned in the direction of airflow through each coil, and are arranged in parallel such that air passing through one coil is not directly introduced linearly into the other coil. The first coil system and the second coil system are arranged such that the airflow directions passing through each coil are non-parallel and in different directions from each other. The first coil system and the second coil system are arranged along two different surfaces of the casing, in orientations that are 90° apart from each other. The first coil system is positioned along the rear end surface of the casing and allows air to pass from rear to front. The second coil system is arranged along one of the left or right sides of the casing, and allows air to pass from one side to the other. When only the first coil system is operating, the air that has passed through the first coil system travels straight through the casing and is blown out into the server room at the front. When only the second coil is operating, the air that has passed through the second coil is bent forward within the casing and then blown out into the server room at the front. The cooling method includes the step of stopping the first coil system and the second coil system while one of them is operating. A cooling method characterized by the following features.

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