JP2018151094A - Air conditioning system - Google Patents

Abstract

To provide an air conditioning system capable of cooling a storage room to a desired temperature while suppressing power consumption throughout the year. An air conditioning system according to an embodiment includes a cooling tower, a cooling device, a heat exchanger, a pump, a blower, a detection unit, and a control unit. The cooling tower cools the first refrigerant by free cooling. The cooling device can cool the second refrigerant to a temperature lower than the temperature of the first refrigerant cooled by the cooling tower. In the heat exchanger, the first refrigerant cooled by the cooling tower and the second refrigerant cooled by the cooling device flow inside. The pump conveys the first refrigerant. The blower causes air to flow through the heat exchanger and then to the object to be cooled in the accommodation chamber. The said detection part detects the temperature of the said air before flowing into the said to-be-cooled body through the said heat exchanger. The control unit operates the cooling device when the temperature detected by the detection unit is equal to or higher than a predetermined first reference temperature. [Selection] Figure 1

Description

  Embodiments described herein relate generally to an air conditioning system.

  An accommodation room such as a data center accommodates ICT (Information and Communication Technology) equipment (cooled body) such as a server and storage that generate heat. When operating such an ICT device, it is necessary to cool the ICT device by an air conditioning system because the ICT device generates heat. The data center needs to be cooled with a stable temperature.

Generally, a cooling device that cools a refrigerant using a compressor or the like can generate a low-temperature refrigerant of about 5 to 10 ° C. regardless of the outside air temperature. For this reason, a cooling device is used in the data center. However, the high power consumption of the cooling device is a problem.
On the other hand, free cooling is known as an energy saving technique in an air conditioning system. Free cooling is a system that generates cold water for air conditioning using a cooling tower or the like that cools water with the heat of vaporization from outside air. Free cooling can significantly reduce power consumption compared to a cooling device.

  However, in free cooling, it is difficult to generate low-temperature water in summer or the like when the outside air temperature is high. For this reason, free cooling is rarely used in data centers.

JP 2011-129149 A

  The problem to be solved by the present invention is to provide an air conditioning system capable of cooling power to a desired temperature while suppressing power consumption throughout the year.

  The air conditioning system of the embodiment includes a cooling tower, a cooling device, a heat exchanger, a pump, a blower, a detection unit, and a control unit. The cooling tower cools the first refrigerant directly or indirectly by free cooling. The cooling device can cool the second refrigerant to a temperature lower than the temperature of the first refrigerant cooled by the cooling tower. In the heat exchanger, the first refrigerant cooled by the cooling tower and the second refrigerant cooled by the cooling device flow inside. The pump conveys the first refrigerant. The blower causes air to flow through the heat exchanger and then to the object to be cooled in the accommodation chamber. The detection unit detects the temperature of the first refrigerant flowing into the heat exchanger, or the temperature of the air before flowing through the heat exchanger to the cooled object. The control unit controls the pump and the cooling device. The control unit operates the cooling device when the temperature detected by the detection unit is equal to or higher than a predetermined first reference temperature while the pump is operating.

The schematic block diagram which shows the air conditioning system of one Embodiment. The figure explaining operation | movement of the air conditioning system of one Embodiment. The figure explaining operation | movement of the air conditioning system of one Embodiment. The sectional view of the plane of the data center which the air-conditioning system in the modification of one embodiment cools.

  Hereinafter, an air conditioning system according to an embodiment will be described with reference to the drawings.

  As shown in FIG. 1, in the data center (accommodating room) R1, an electronic device (cooled body) used as an ICT device is disposed on a floor surface (installation surface) R11 in a state of being accommodated in a rack W. . The air conditioning system 1 of this embodiment is used to cool the inside of the data center R1. The data center R1 shown in FIG. 1 is a side sectional view.

For example, the data center R1 includes a machine room R12, a low temperature room R13, and a high temperature room R14 arranged in this order along a horizontal plane. The rack W is disposed across the low temperature chamber R13 and the high temperature chamber R14. Portions other than the rack W at the boundary between the low greenhouse R13 and the high temperature chamber R14 are partitioned by a wall R16.
A main heat exchanger 36 and a main blower 46, which will be described later, in the air conditioning system 1 are disposed in the machine room R12 while being accommodated in the casing 61. The casing 61 is disposed at a position near the low temperature chamber R13 in the machine room R12. Portions other than the casing 61 at the boundary between the machine room R12 and the low temperature room R13 are partitioned by a wall R17.
A portion of the machine room R12 opposite to the low temperature room R13 and the high temperature room R14 are connected by a piping duct R18.

  The space in the low greenhouse R13 is a cold area in which the air temperature is controlled to be low by the air conditioning system 1. The air in the cold area flows toward the rack W as will be described later. The air passes through the rack W and exchanges heat with the electronic equipment accommodated in the rack W. The air exchanged heat with the electronic device flows out into the high temperature chamber R14. The space in the high greenhouse R14 is a hot area through which air whose temperature has increased due to heat exchange with electronic equipment flows.

The air conditioning system 1 includes a cooling tower 11, a cooling device 31, a main heat exchanger (heat exchanger) 36, a second pump (pump) 41, a main blower (blower) 46, and a temperature sensor (detection unit). 51 and a control unit 56.
For example, the cooling tower 11 includes an auxiliary blower 12 that sends wind to the first water flowing down in the cooling tower 11. When the auxiliary blower 12 is operated, the auxiliary blower 12 sends wind to the first water. When the operation of the auxiliary blower 12 is stopped, the auxiliary blower 12 does not send wind to the first water. In addition, it is preferable that the auxiliary blower 12 is a blower capable of changing the rotation speed.
The cooling tower 11 cools the first water by free cooling, for example, by bringing the first water and the atmosphere into contact with each other to take heat of vaporization from the first water. The cooling tower 11 passively cools the first water.

The cooling tower 11 is disposed on the annular first transport pipe 13. On this 1st conveyance piping 13, the 1st pump 14 and the 1st auxiliary heat exchanger 15 are arrange | positioned.
The first water is accommodated in the cooling tower 11, the first transfer pipe 13, and the first auxiliary heat exchanger 15. When the first pump 14 is operated, the first water flows into the cooling tower 11, the first transfer pipe 13, and the first auxiliary heat exchanger 15. When the operation of the first pump 14 is stopped, the flow of the first water stops. In addition, it is preferable that the 1st pump 14 is a pump which can change an operating frequency. As the operating frequency increases, the flow rate of the first water flowing through the cooling tower 11, the first transfer pipe 13, and the first auxiliary heat exchanger 15 increases.

The first auxiliary heat exchanger 15 exchanges heat with the second auxiliary heat exchanger 18 while being accommodated in the casing 17. As the auxiliary heat exchangers 15 and 18, known heat exchangers such as a coil type and a shell and coil type can be appropriately selected and used.
The second auxiliary heat exchanger 18 is disposed on the annular second transfer pipe 19. A cushion tank 20, a second pump 41, a first main heat exchanger (first heat exchanger) 37, and an on-off valve 21 are disposed on the second transfer pipe 19.
The cushion tank 20 stores a certain amount of second water therein. The cushion tank 20 is for flowing the cooled second water into the first main heat exchanger 37 when the cooling by the cooling tower 11 is temporarily impossible. The cushion tank 20 is not an essential component of the air conditioning system 1.
The second pump 41 conveys second water (first refrigerant).

The on-off valve 21 may be one that can be remotely operated by the control unit 56. When the on-off valve 21 is opened, the second water can flow through the second transfer pipe 19. When the on-off valve 21 is closed, the second water cannot flow through the second transfer pipe 19.
The ends of the bypass pipe 23 are connected to the second water inlet and outlet of the second auxiliary heat exchanger 18 in the second transfer pipe 19, respectively. An on-off valve 24 is disposed on the bypass pipe 23. The on-off valve 24 is configured in the same manner as the on-off valve 21.
The bypass pipe 23 and the on-off valve 24 are not essential components of the air conditioning system 1.

The second water is accommodated in the second auxiliary heat exchanger 18, the second transfer pipe 19, the cushion tank 20, and the first main heat exchanger 37. When the second pump 41 is operated, the second water flows into the second auxiliary heat exchanger 18, the second transfer pipe 19, the cushion tank 20, and the first main heat exchanger 37. When the operation of the second pump 41 is stopped, the flow of the second water is stopped. In addition, it is preferable that the 2nd pump 41 is a pump which can change an operating frequency.
As the first auxiliary heat exchanger 15 and the second auxiliary heat exchanger 18 exchange heat, the second water is indirectly cooled with the first water.
When the first water comes into contact with the atmosphere, dust and the like are easily contained inside and contaminated. Since the first water does not flow in the first main heat exchanger 37 and the second water indirectly cooled by the first water flows, the first main heat exchanger 37 is prevented from being clogged with dirt.

The cooling device 31 has a first refrigerator 32 and a second refrigerator 33. The refrigerators 32 and 33 are vapor compression refrigerators using a compressor, and are so-called PAC (package type) outdoor units. The refrigerators 32 and 33 cool the refrigerant (second refrigerant). For example, the refrigerant is R410A, but is not particularly limited thereto. The refrigerators 32 and 33 actively cool the refrigerant.
The cooling device 31 can cool the refrigerant to a temperature lower than the temperature of the second water cooled by the cooling tower 11. The power consumption of the cooling tower 11 required to take the predetermined amount of heat from the water in the cooling tower 11 is less than the power consumption of the cooling device 31 required to take the predetermined amount of heat from the refrigerant in the cooling device 31.
The compressors included in the refrigerators 32 and 33 may be capable of changing the operating frequency. However, in the present embodiment, description will be made assuming that the compressors included in the refrigerators 32 and 33 cannot change the operating frequency.
The refrigerators 32 and 33 are disposed on the third transfer pipe 34. In addition, the 3rd conveyance piping 34 has simplified and showed the structure. For example, the refrigerators 32 and 33 are connected to the third transfer pipe 34 in parallel. Note that the number of refrigerators included in the cooling device 31 is not limited to two, and may be one or three or more.

A second main heat exchanger (second heat exchanger) 38 is disposed on the third transfer pipe 34. The second main heat exchanger 38 and the first main heat exchanger 37 constitute a main heat exchanger 36. As the main heat exchangers 37 and 38, coil-type heat exchangers can be appropriately selected and used. In the main heat exchanger 36, the second water indirectly cooled by the cooling tower 11 and the refrigerant cooled by the cooling device 31 flow.
A refrigerant is accommodated in the refrigerators 32 and 33, the third transfer pipe 34, and the second main heat exchanger 38. When one of the first refrigerator 32 and the second refrigerator 33 is operated, the refrigerant flows in the third transfer pipe 34 and the second main heat exchanger 38. When both the first refrigerator 32 and the second refrigerator 33 are operated, the flow rate of the refrigerant increases. When the operation of the first refrigerator 32 and the second refrigerator 33 is stopped, the flow of the refrigerant is stopped.
The aforementioned first main heat exchanger 37 is arranged on the upstream side of the air flowing by the main blower 46 rather than the second main heat exchanger 38. That is, air that has passed through the first main heat exchanger 37 and is cooled by the first main heat exchanger 37 passes through the second main heat exchanger 38.

The main blower 46 includes a first axial fan 47 and a second axial fan 48.
The main heat exchangers 37 and 38 are disposed on the suction side of the axial fans 47 and 48 where the axial fans 47 and 48 suck in air. The axial fans 47 and 48 are arranged in parallel so as to face the second main heat exchanger 38. Air passing through the main heat exchanger 36 and the main blower 46 flows through a through hole 62 formed in the casing 61.
The blower 46 allows air to flow through the main heat exchanger 36 and then to the electronic equipment in the data center R1. At this time, the blower 46 causes the air that has passed through the main heat exchanger 36 to flow along the floor surface R11.

The main heat exchangers 37 and 38 may be disposed on the discharge side of the axial fans 47 and 48 where the axial fans 47 and 48 discharge air. One of the main heat exchangers 37 and 38 may be disposed on the suction side of the axial fans 47 and 48, and the other of the main heat exchangers 37 and 38 may be disposed on the discharge side of the axial fans 47 and 48.
The number of axial fans that the main blower has is not limited to two, but may be one or three or more. The main blower may include a centrifugal fan, a cross flow fan, or the like instead of the axial flow fan.

  For example, the temperature sensor 51 is attached to the ceiling of the low temperature chamber R13. The temperature sensor 51 detects the temperature of the air in the low temperature chamber R13, that is, the temperature of the air before flowing through the main heat exchanger 36 to the electronic device.

The control unit 56 includes an arithmetic circuit and a memory. The memory stores a control program for the arithmetic circuit, predetermined first reference temperature, second reference temperature, and the like that serve as a reference for temperature control.
The control unit 56 is connected to the auxiliary blower 12, the first pump 14, the on-off valves 21 and 24, the second pump 41, the cooling device 31, the main blower 46, and the temperature sensor 51.
The control unit 56 controls the auxiliary blower 12, the first pump 14, the on-off valves 21 and 24, the second pump 41, the cooling device 31, and the main blower 46 based on the detection result of the temperature sensor 51.

Next, the operation of the air conditioning system 1 configured as described above will be described.
First, the operation of the air conditioning system 1 in the process in which the outside air temperature increases with time from a state in which the outside air (atmosphere) temperature is relatively low will be described.

In FIG. 2, each temperature with respect to time and the change of the operation state of the pumps 14 and 41 and the refrigerators 32 and 33 are shown. A line L1 represented by a solid line (the same applies to the line L1a and the like) indicates the outside temperature. A line L2 represented by a dotted line (the same applies to the line L2a and the like) indicates the temperature of the second water. A line L3 represented by a one-dot chain line (the same applies to the line L3a and the like) indicates the temperature detected by the temperature sensor 51. Further, FIG. 2 shows whether the pumps 14 and 41 and the refrigerators 32 and 33 are operating or stopped.
It is assumed that the on-off valve 21 is opened in advance and the on-off valve 24 is closed.
As time elapses in the order of the periods P1, P2, and P3, the outside air temperature represented by the lines L1, L1a, and L1c increases. However, it is assumed that the outside air temperature is constant during each of the periods P1, P2, and P3. Such periods P1, P2, and P3 may be different periods in a certain day, or may be different periods in a year.
For example, it is assumed that the temperature that is the control target of the air in the low temperature chamber R13 is 25 ° C. In addition, each temperature in the above-mentioned and FIG. 2 is one example used for description, and is not restricted to these temperatures.

  As in the period P1, when the outside air temperature is relatively low, the initial condition is as follows. That is, the auxiliary blower 12 rotates at a relatively slow rotation speed. The pumps 14 and 41 are each operated at a relatively low operating frequency. The refrigerators 32 and 33 have stopped operating. The axial fans 47 and 48 are operating.

  For example, the first water having a temperature close to the outside air temperature is cooled by the heat of vaporization being deprived in the cooling tower 11 and the temperature is lowered. The second water is cooled by the first water in the auxiliary heat exchangers 15 and 18, and becomes a temperature represented by a line L2 lower than the outside air temperature. That is, the temperature of the second water decreases by ΔT1 with respect to the outside air temperature. The air flowing in the casing 61 by the operation of the axial fans 47 and 48 is cooled by the second water in the first main heat exchanger 37. The air cooled by the first main heat exchanger 37 flows into the low temperature chamber R13. As a result, the temperature detected by the temperature sensor 51 is 25 ° C. represented by the line L3.

  The cooled air flows along the floor surface R11 and cools the electronic equipment that generates heat in the rack W. Air heated by cooling the electronic device flows into the high temperature chamber R14. The heated air flows through the piping duct R18 and the machine room R12. The heated air is cooled again in the first main heat exchanger 37.

Next, as in the period P2, a case where the outside air temperature represented by the line L1a is higher than the outside air temperature in the period P1 will be described. In this case, the temperature of the second water rises to the temperature represented by the line L2a according to the outside air temperature. The temperature detected by the temperature sensor 51 rises to the temperature represented by the line L3a.
The controller 56 increases the operating frequency of the pumps 14 and 41 at time t1. The flow rate of the 1st water which flows through the inside of the cooling tower 11 etc. increases, and the cooling capacity which cools the 1st water in the cooling tower 11 increases. The cooling capacity as used herein means the amount of heat taken per unit time from a cooling target such as water.
When the second water is cooled by the first water, the temperature of the second water becomes the temperature represented by the line L2b. A temperature difference ΔT2 between the outside air temperature and the temperature of the second water is larger than the above-described temperature difference ΔT1. By cooling with the second water having the increased temperature difference ΔT2, the temperature detected by the temperature sensor 51 is maintained at 25 ° C. represented by the line L3b.

When the outside air temperature further rises, the rotational speed of the auxiliary blower 12 in the cooling tower 11 is increased. Thereby, the cooling capacity for cooling the first water in the cooling tower 11 is increased, and the temperature detected by the temperature sensor 51 is kept at 25 ° C.
In this way, first, the temperature sensor 51 detects by increasing the cooling capacity of the cooling tower 11 or increasing the operating frequency of the second pump 41 without operating the refrigerators 32 and 33. Keep temperature at 25 ° C.

When the outside air temperature further rises as indicated by the line L1c in the period P3, the temperature of the second water rises higher than the temperature indicated by the line L2b as indicated by the line L2c. As indicated by the line L3c, the temperature detected by the temperature sensor 51 is higher than the temperature indicated by the line L3b.
The control unit 56 operates the cooling device 31 at time t2 when the temperature detected by the temperature sensor 51 is equal to or higher than a predetermined first reference temperature. The first reference temperature is a temperature higher than the target temperature. In this example, the first refrigerator 32 of the two refrigerators 32 and 33 is operated.
When the first refrigerator 32 is operated, the refrigerant is cooled by the first refrigerator 32, and the cooled refrigerant flows in the second main heat exchanger 38 through the third transfer pipe 34. The air flowing in the casing 61 passes through the first main heat exchanger 37 in which the second water flows, and is cooled to some extent in advance. This air is further cooled through the second main heat exchanger 38 in which the refrigerant flows. Thereby, the temperature detected by the temperature sensor 51 is maintained at 25 ° C. represented by the line L3d.

When the first refrigerator 32 is operated, the operation of the auxiliary blower 12 and the pumps 14 and 41 may be stopped so that the cooled refrigerant does not flow through the first main heat exchanger 37. . The on-off valve 21 may be closed so that the cooled refrigerant does not flow through the first main heat exchanger 37.
When the outside air temperature further rises, the second refrigerator 33 may be operated.

Next, operation | movement of the air conditioning system 1 in the process in which outside temperature falls with time from the state where outside temperature is comparatively high is demonstrated.
Assume that the initial conditions are as follows. That is, the auxiliary blower 12 rotates at a relatively high rotational speed. The pumps 14 and 41 are each operated at a relatively large operating frequency. The refrigerators 32 and 33 and the axial fans 47 and 48 are operating.

In FIG. 3, each temperature with respect to time and the change of the driving | running state of the pumps 14 and 41 and the refrigerators 32 and 33 are shown. The vertical axis and horizontal axis in FIG. 3, the pumps 14 and 41, and the operating states of the refrigerators 32 and 33 are displayed in the same manner as in FIG. It seems that the outside air temperature is represented by a line L1e. The temperature of the second water is expressed by a line L2e, and the temperature detected by the temperature sensor 51 is expressed by a line L3e (the same applies to the line L3f and the like).
The control unit 56 stops the operation of the second refrigerator 33 at time t5 and reduces the cooling capacity of the cooling device 31. Even when the cooling capacity of the cooling device 31 is lowered, if the temperature detected by the temperature sensor 51 does not rise above the temperature represented by the line L3e as represented by the line L3f, the following control is performed. The reason why the temperature detected by the temperature sensor 51 does not increase is that the target temperature can be maintained even if the inside of the data center R1 is not cooled much by reducing the outside air temperature.
That is, the control unit 56 stops the operation of the cooling device 31 by stopping the operation of the first refrigerator 32 at time t6. However, the cooling of the first water by the cooling tower 11 is performed by continuing the operation of the pumps 14 and 41.

Note that the control unit 56 may maintain the cooling capacity of the cooling device 31 that has been reduced at time t5 without performing control for stopping the operation of the cooling device 31.
Further, the control unit 56 may stop the operation of the cooling device by stopping the operation of the refrigerators 32 and 33 at time t5. In this case, even if the operation of the cooling device 31 is stopped, the operation of the cooling device 31 may be stopped if the temperature detected by the temperature sensor 51 does not rise.
The control unit 56 may perform control so as to further reduce the cooling capacity of the cooling device 31 without stopping the operation of the first refrigerator 32 at time t6. Specifically, when the compressor of the first refrigerator 32 can change the operating frequency, the operating frequency of the compressor is decreased.

When the temperature detected by the temperature sensor 51 increases when the cooling capacity of the cooling device 31 is lowered, the cooling capacity of the cooling device 31 may be increased.
In addition, after stopping the operation of the cooling device, the rotational speed of the auxiliary blower 12 may be decreased. The operating frequency of the pumps 14 and 41 may be reduced.

Next, the operation of the air conditioning system 1 when the temperature detected by the temperature sensor 51 falls below a predetermined temperature will be described.
Assume that the initial conditions are as follows. That is, the auxiliary blower 12 is rotating. The pumps 14 and 41, the refrigerators 32 and 33, and the axial fans 47 and 48 are operating.
The controller 56 stops the operation of the pumps 14 and 41 and the cooling device 31 when the temperature detected by the temperature sensor 51 becomes equal to or lower than the second reference temperature. For example, the second reference temperature is about 15 ° C., which is a temperature at which condensation does not occur in the electronic devices in the rack W. Note that the second reference temperature may be a temperature lower than the first reference temperature described above.

  Even after the operation of the pumps 14 and 41 and the cooling device 31 is stopped, the operation of the axial fans 47 and 48 is continued. By causing the air heated by the waste heat of the electronic device to circulate in the data center R1, it is possible to suppress dew condensation in the electronic device.

  Thus, for example, in the spring and autumn when the outside air temperature is relatively low, the inside of the data center R1 is cooled only by the cooling tower 11, and in the summer when the outside air temperature is relatively high, the cooling device 31 is operated as necessary.

  As described above, according to the air conditioning system 1 of the present embodiment, when the outside air temperature is relatively low, the cooling tower 11 with relatively low power consumption is cooled and the operation of the cooling device 31 is stopped. When the outside air temperature is relatively high, the cooling device 31 is operated so that it can be cooled to the target temperature. Since only the cooling tower 11 may be operated, the power consumption can be suppressed throughout the year, and the inside of the data center R1 can be cooled to a desired temperature.

The main blower 46 flows the air that has passed through the main heat exchanger 36 to the electronic device along the floor surface R11. The air that has passed through the main heat exchanger 36 can be flowed from the main heat exchanger 36 to the electronic device through a short flow path, without passing through the floor once and then flowing to the electronic device on the floor surface R11. By shortening the air flow path, it is possible to prevent the temperature of the air from rising while flowing in the flow path. Furthermore, even if the temperature of the first water and the refrigerant is increased, the data center R1 can be cooled to a desired temperature. Thereby, the power consumption of the air conditioning system 1 can be suppressed. In one year, the period during which the inside of the data center R1 can be cooled to a desired temperature only by the cooling tower 11 becomes longer.
By shortening the air flow path, the power consumption of the main blower 46 necessary for flowing air can be suppressed. Since the air that has passed through the main heat exchanger 36 flows on the floor surface R11, a wide air flow path can be secured in the low temperature chamber R13, and the air flow rate can be increased. Therefore, more electronic devices can be mounted on the rack W.

  The 1st main heat exchanger 37 is arrange | positioned rather than the 2nd main heat exchanger 38 in the upstream of the air which flows with the main air blower 46. FIG. The air is cooled by the first main heat exchanger 37 and then further cooled by the second main heat exchanger 38. By using the 1st main heat exchanger 37 for the pre-cooling of the 2nd main heat exchanger 38, the cooling capacity required by the cooling device 31 can be suppressed, and the power consumption as the whole air conditioning system 1 can further be suppressed.

If the temperature detected by the temperature sensor 51 does not increase when the cooling capacity of the cooling device 31 is reduced, the control unit 56 maintains the reduced cooling capacity of the cooling device 31. By reducing the cooling capacity of the cooling device 31, the power consumption of the air conditioning system 1 as a whole can be suppressed.
The control unit 56 stops the operation of the cooling device 31 when the temperature detected by the temperature sensor 51 does not increase when the cooling capacity of the cooling device 31 is reduced. Therefore, the power consumption of the air conditioning system 1 as a whole can be further suppressed.

The controller 56 stops the operation of the pumps 14 and 41 and the cooling device 31 when the temperature detected by the temperature sensor 51 becomes equal to or lower than the second reference temperature. Thereby, it can suppress that dew condensation arises in an electronic device.
By using not only the cooling device 31 but also the cooling tower 11, the period during which the cooling device 31 is operated in one year is shortened. For this reason, the compressor used for the cooling device 31 can be used over a longer period, and the frequency of replacing this compressor can be suppressed.

The temperature sensor 51 may be configured to detect the temperature of the second water flowing into the first main heat exchanger 37. In this case, the temperature of the second water is controlled on the basis of 18 ° C.
When the operation of the pumps 14 and 41 is stopped when the cooling device 31 is operated, the first main heat exchanger 37 cannot be used for pre-cooling the second main heat exchanger 38. In such a case, the first main heat exchanger 37 may be disposed on the downstream side of the air from the second main heat exchanger 38.

As shown in FIG. 4, a data center R2 may be configured. In addition, about the structure of the air conditioning system 1 in the data center R2, only the principal part is shown.
In the data center R2, a plurality of racks W are arranged side by side in a predetermined direction (hereinafter referred to as the first direction X) with no gap therebetween. On the rack W at one end portion in the first direction X, casings 61 having an outer shape equivalent to the rack W in a plan view are arranged side by side without a gap. The casing 61 and the outer wall of the data center R2 are partitioned by a wall R21 extending in the first direction X.
Of the plurality of racks W, the rack W at the other end in the first direction X and the outer wall of the data center R2 are partitioned by a wall R22 extending in the first direction X.

In the casing 61, air flows in a direction orthogonal to the first direction X (hereinafter referred to as the second direction Y) by the main blower 46 and is cooled by the main heat exchangers 37 and 38. The air that has flowed out of the casing 61 flows in the first direction X and flows into each rack W. A room on the side where air flows into each rack W in the data center R2 is a low temperature room R24. A space in the low greenhouse R24 is a cold area in which the air temperature is controlled to be low by the air conditioning system 1.
The air flows in each rack W in the second direction Y, and exchanges heat with the electronic device. The air flowing out from each rack W flows in the first direction X. The room on the side where air flows out from each rack W is the high temperature chamber R25. The space in the high greenhouse R25 is a hot area through which air whose temperature has increased due to heat exchange with electronic equipment flows.
The air flowing through the high greenhouse R25 in the first direction X flows into the casing 61. The air flowing into the casing 61 is cooled again by the main heat exchangers 37 and 38.

In the present embodiment, the cooling device is a gas compression refrigerator. However, the cooling device is not limited to this, and may be an absorption refrigerator, a Peltier cooler, a magnetic refrigerator, or the like.
When the first main heat exchanger 37 is not easily clogged with dirt, the air conditioning system does not include the auxiliary heat exchangers 15 and 18, and the transfer pipes 13 and 19 are integrated to form one annular transfer pipe. May be. In this case, the first water and the second water are integrated to form a first refrigerant, and the first refrigerant flows in the transfer pipe. The first refrigerant is directly cooled by the cooling tower 11.
When the refrigerant cooled by the cooling device is water, the main heat exchanger 36 may be configured by one heat exchanger without being divided into the main heat exchangers 37 and 38. In this case, the water cooled by the cooling tower 11 and the water cooled by the cooling device 31 merge and flow in one heat exchanger. The water that has cooled the air by flowing in the heat exchanger is divided in flow, partly flowing toward the cooling tower 11, and the rest flowing toward the cooling device 31.

  According to at least one embodiment described above, by having the main heat exchanger 36, the temperature sensor 51, and the control unit 56, power consumption is suppressed regardless of the outside air temperature, and the data center R1 is brought to a desired temperature. Can be cooled.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Air conditioning system, 11 ... Cooling tower, 31 ... Cooling device, 36 ... Main heat exchanger (heat exchanger), 37 ... 1st main heat exchanger (1st heat exchanger), 38 ... 2nd main heat exchange (Second heat exchanger), 41 ... second pump (pump), 46 ... main blower (blower), 51 ... temperature sensor (detection unit), 56 ... control unit, R1, R2 ... data center (accommodation chamber) , R11 ... Floor (installation surface)

Claims (6)

A cooling tower for directly or indirectly cooling the first refrigerant by free cooling;
A cooling device capable of cooling the second refrigerant to a temperature lower than the temperature of the first refrigerant cooled in the cooling tower;
A heat exchanger in which the first refrigerant cooled by the cooling tower and the second refrigerant cooled by the cooling device flow;
A pump for conveying the first refrigerant;
A blower that causes air to flow through the heat exchanger and then to the object to be cooled in the accommodation chamber;
A detector that detects the temperature of the first refrigerant flowing into the heat exchanger, or the temperature of the air before flowing through the heat exchanger to the cooled object;
A control unit for controlling the pump and the cooling device;
With
The controller is
An air conditioning system that operates the cooling device when the temperature detected by the detection unit is equal to or higher than a predetermined first reference temperature in a state where the pump is operating. The object to be cooled is disposed on an installation surface of the object to be cooled in the storage chamber,
The air conditioning system according to claim 1, wherein the blower causes the air that has passed through the heat exchanger to flow along the installation surface. The heat exchanger has a first heat exchanger and a second heat exchanger,
The first refrigerant flows in the first heat exchanger,
The second refrigerant flows in the second heat exchanger,
The air conditioning system according to claim 1 or 2, wherein the first heat exchanger is disposed on an upstream side of the air flowing by the blower from the second heat exchanger. When the temperature detected by the detection unit does not increase when the control unit reduces the cooling capacity of the cooling device or stops the operation of the cooling device, the control unit decreases the cooling capability. The air conditioning system according to any one of claims 1 to 3, wherein the cooling capacity of the cooling device is maintained or the operation of the cooling device is kept stopped. When the temperature detected by the detection unit does not increase when the cooling capacity of the cooling device is reduced, the control unit further reduces the cooling capacity of the cooling device or operates the cooling device. The air conditioning system according to claim 1, wherein the air conditioning system is stopped. The control unit stops the operation of the pump and the cooling device when a temperature detected by the detection unit becomes equal to or lower than a predetermined second reference temperature lower than the first reference temperature. The air conditioning system according to any one of 1 to 5.

Images