JP5243092B2 - Rack type air conditioner - Google Patents

Description

  The present invention relates to a rack type air conditioner including a rack type air conditioner, and more particularly to a rack type air conditioner suitable for an air conditioning system of an information communication machine room that uses both ambient air conditioning and local air conditioning.

In recent years, information communication (ICT) devices are rapidly increasing in speed, capacity, and density. These devices are generally stored in a 19-inch server rack conforming to the US IEA standard and housed in an information communication machine room (data center). Server racks often take in cool air from the front and exhaust from the top or back, and each rack is arranged in a horizontal row in the same direction. A plurality of such rack rows are arranged in the machine room, the intake surfaces and the intake surfaces of adjacent rows, and the exhaust surfaces and the exhaust surfaces are opposed to each other. Here, the passage between the intake surfaces is called cold aisle because cold air is supplied from the double floor. On the other hand, the passage between the exhaust surfaces is called hot aisle because the temperature rises due to exhaust from the rack.
In this case, in the conventional method (ambient air conditioning method) that uniformly air-conditions the entire room only by supplying cold air from the double floor, a local high temperature area is generated in the cold aisle due to uneven distribution of heat from the rack, and information communication equipment・ The problem of high-temperature failure of the equipment occurs. In order to solve such a problem, a technique for installing an air conditioner above a cold aisle for local cooling has been proposed (for example, Patent Document 1).

FIG. 12 shows a rack air-conditioning system 100 according to this system. A local air conditioner 102 is installed above a cold aisle 105 formed between server rack rows 104a and 104b in a machine room 101. FIG. Thus, each server rack is cooled by the cold air supplied from the ambient air conditioner 107 through the double floor space 106 and the cold air supplied from above by the local air conditioner 102.
On the other hand, there is a system in which local air conditioners are arranged in a rack row. In particular, a rack type air conditioner having the same module as a server rack has been put into practical use in order to improve space efficiency. The rack type air conditioner is disposed so that the direction of intake and exhaust is opposite to that of the server rack 2, that is, sucks high temperature exhaust in the hot aisle space and blows out cooling air to the cold aisle side.
JP 2003-166729 A

However, in the air conditioning system of the information communication machine room, in order to always balance the air volume supplied to the cold aisle space and the total air volume sucked by the server rack, only the refrigerant circulation is stopped when the local air conditioner is thermo-OFF, Generally, the blower fan does not stop. For this reason, since the local air conditioner sucks hot exhaust on the hot aisle side and blows it out directly while the thermo is off, the cold aisle side temperature may rise rapidly and deviate from the allowable upper limit temperature of the information communication equipment / device. There is.
Even with rack type air conditioners that shut off the blower fan when the thermo is turned off, air is always sent from the cold aisle side to the hot aisle side by the fan built in the ICT equipment, so the air pressure on the hot aisle side is the cold aisle side. Often higher. In this case, even if the fan of the rack type air conditioner is stopped due to the pressure difference, an air flow is generated from the hot aisle side to the cold aisle side through the inside of the air conditioner, thereby deteriorating the cold aisle environment. In particular, when aisle capping is performed, the pressure difference becomes large, so the influence is great.
The present invention is intended to solve such a problem, and provides a rack-type air conditioner that can avoid the occurrence of a high-temperature failure of information communication equipment and devices when the capacity of the rack-type air conditioner is reduced. It is.

The gist of the present invention is as follows. That is, the rack-type air conditioner according to the present invention is
(1) Used in an air conditioning system that uses double floor blow-off air conditioning with an ambient air conditioner and local air conditioning with a rack type air conditioner in a room where a cold aisle and hot aisle are formed by a plurality of server rack rows. A rack-type air conditioner that sucks in hot aisle exhaust on the hot aisle side and blows out cooling air to the cold aisle side, and an exhaust inflow control that controls inflow or shut-off of high temperature exhaust in conjunction with predetermined operating conditions And means.
In the present invention, cold aisle and hot aisle include both those that are partitioned by capping and those that are not partitioned.
(2) The predetermined operating condition is one or both of circulating or stopping the circulation of the refrigerant, and operating or stopping the blowing fan.
By shutting off the exhaust inflow in conjunction with the refrigerant circulation stop, the inflow of high-temperature exhaust to the cold aisle side can be prevented, thereby preventing a rapid temperature rise of the cold aisle. Further, even when the blower fan stops due to a failure or the like in the refrigerant circulation state, it is possible to prevent drain generation due to a decrease in the refrigerant evaporation temperature due to a decrease in the air volume by blocking the exhaust inflow.
(3) The exhaust inflow control means includes a high-temperature exhaust inflow shut-off shutter and the shutter opening / closing means.
(4) The shutter opening / closing means is configured to be opened by the suction force during the operation of the blower fan and closed by gravity or a spring mechanism when the operation is stopped.

(5) The air conditioning system is a refrigerant direct expansion system, and the shutter opening / closing means utilizes a differential pressure across the expansion valve provided in the refrigerant piping path.
(6) The exhaust inflow control means includes airflow sensing means for sensing the flow direction of the airflow in the aircraft, and means for operating the blower fan in a direction opposite to the airflow direction sensed by the airflow sensing means. It is characterized by comprising.
(7) The airflow sensing means is an anemometer arranged in the aircraft.
(8) The rack type air conditioner according to claim 6, wherein the air flow sensing means is means for detecting a differential pressure between the front side and the back side of the machine body.
(9) The rack-type air conditioner is characterized in that
By using a rack-type air conditioner configured in the same module as the 19-inch server rack, the server rack mount can be used as it is, so that construction is easy and the degree of freedom in arrangement is increased. In addition, there is an advantage that it is possible to improve the space efficiency because of the good fit in the rack row.
(10) In each of the above-described inventions, a system that uses a double floor blow-off air conditioning by an ambient air conditioner and a local air conditioning by a rack type air conditioner can be used as the air conditioning system.

According to each of the above-mentioned inventions, it is possible to prevent the generation of airflow passing through the inside of the airframe when the thermo is OFF, and it is possible to prevent inflow of high-temperature air to the cold aisle side. Thereby, it is possible to prevent the occurrence of a high-temperature failure in a nearby ICT device.
Moreover, energy saving of the machine room air conditioning can be achieved by preventing mixing of cold air and warm air.

  Hereinafter, an embodiment of a rack type air conditioner according to the present invention will be described in more detail with reference to FIGS. In the drawings, the same components are denoted by the same reference numerals, and redundant description is omitted. Needless to say, the scope of the present invention is described in the claims and is not limited to the following embodiments.

(First embodiment)
FIG. 1 is a diagram showing a configuration of a rack-type air conditioner 20 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a cross-sectional configuration of the air conditioning system 1 using the rack-type air conditioner 20. FIG. 3 is a diagram illustrating a planar configuration of the air conditioning system 1. FIG. 4 is a diagram showing a high-temperature exhaust suction control flow of the rack-type air conditioner 20.

2 and 3, an air conditioning system 1 is accommodated in an information communication machine room 5, and a server rack 2 constituting a rack row 3 is divided into an air conditioner 4 that is an ambient air conditioner and a rack that is a local air conditioner. This is a system that is cooled by the mold air conditioner 20.
The air conditioner 4 which is an ambient air conditioner includes an indoor unit 4a having an evaporator 4e and a blower 4c, an outdoor unit 4b mainly composed of a compressor, a condenser (all not shown), and a refrigerant connecting them. A pipe 4d is provided. With this configuration, the cold generated by the refrigeration cycle operation is cooled by exchanging heat with the indoor air introduced into the indoor unit 4a, and supplied to the machine room by the blower 4c.

The interior of the machine room 5 is divided into three spaces by a floor panel 5d and a ceiling panel 5e. A double floor space 5c is formed in the lower part of the floor panel 5d, and a ceiling space 5b is formed in the upper part of the ceiling panel 5e. ing. The indoor unit 4a of the air conditioner 4 and the double floor space 5c are connected via a forward duct 7a. The ceiling space 5b and the indoor unit 4a are connected via a return duct 7b.
The rack row 3 is formed by a plurality of server racks 2 of the same module arranged in a horizontal row. The server rack 2 stores a plurality of rack mount servers 2a, and heat generated from each server is exhausted to the back together with air sucked from the front by a cooling fan (not shown) mounted on each server. The As a result, the entire rack is configured to suck in cool air from the front and exhaust from the back.

Each server rack 2 is arranged so that the intake surface and the intake surface of the adjacent rows face each other, and the exhaust surface and the exhaust surface face each other, so that the cold aisle 6a is provided on the intake surface side and hot air is provided on the exhaust surface side. An aisle 6b is formed. A part of the floor surface of the cold aisle 6a is formed by a perforated panel 5f, and the cool air sent from the air conditioner 4 is blown out to the cold aisle space via the perforated panel 5f.
On one end side of each rack row 3, a switchboard unit (PDU) 9 for supplying power to the in-row rack is disposed. The PDU 9 is also configured in the same module as the server rack 2.
In each rack row 3, an indoor unit 21 of a rack type air conditioner 20 is arranged as a local air conditioner in the vicinity of a server having a large internal heat generation. The indoor unit 21 is the same module as the server rack, and the intake / exhaust direction is opposite to that of the server rack 2. In other words, the hot aisle space is arranged so as to suck in high-temperature exhaust air and blow out cooling air to the cold aisle side.
In the present embodiment, the cold aisle 6a and the hot aisle 6b are open to each other, but one aisle may be capped to partition the two.

With reference to FIG. 1, the rack-type air conditioner 20 includes an indoor unit 21, an outdoor unit 22, and a refrigerant pipe 28 that connects them. The indoor unit 21 includes an evaporator 23, a blower fan 24, a control unit 27, and an electronic expansion valve 26 on the forward side of the refrigerant pipe 28 inside the housing 21 a. The outdoor unit 22 includes a condenser 22c, a blower fan 22d, and a compressor 22b as main components inside a housing 22a. With this configuration, the high-pressure refrigerant liquid condensed in the condenser 22 c is guided to the indoor unit 21 via the refrigerant pipe 28, and is in a low-pressure gas-liquid mixed state in the electronic expansion valve 26 and reaches the evaporator 23. The refrigerant exchanges heat with the high-temperature exhaust sucked from the hot aisle 6b in the evaporator 23, and vaporizes itself to become refrigerant vapor and returns to the compressor 22b. On the other hand, the high temperature exhaust gas becomes cold air and is blown out to the cold aisle side by the blower fan 24.
A shutter 25 is attached to the exhaust suction portion on the back side of the housing 21a. The shutter 25 includes a shutter box 25a, a plurality of slats 25c, and left and right chains 25c as main components. The slats 25b and the chain 25c are connected so as to be swingable. By operating an electric drive unit (not shown) built in the shutter box 25a, the left and right chains 25c are swung to freely open and close each slat. It is configured. The slat 25c is configured so as to shield the entire exhaust suction portion in the closed state and prevent high-temperature exhaust from flowing in.

  The rack air-conditioning system 1 is configured as described above, and next, cooling of each server rack 2 during steady operation will be described with reference to FIGS. In this case, it is assumed that the shutter 25 of the air conditioner 20 is in an open state. The room air introduced into the air conditioner 4 exchanges heat in the evaporator 4e to become cold air, and is sent to the double floor space 5c by the blower 4c through the forward duct 7a. The cold air passes through the perforated panel 5f, is supplied to the cold aisle 6a, is further introduced into each server rack, and is cooled to the hot aisle 6b as high-temperature exhaust after cooling the server 2a. A part of the hot exhaust gas rises as it is in the hot aisle 6b, is led to the ceiling space 5b from the ceiling suction port 5h, and is returned to the air conditioner 4 through the return side duct 7b. A part of the high-temperature exhaust is taken into the indoor unit 21 through the open shutter 25 of the rack-type air conditioner 20, cooled by the evaporator 23 in the machine to become cold air, and then blown into the cold aisle 6 a by the blower fan 24. It is blown out, mixed with the cold air from the air conditioner 4, and sucked into each server rack as described above. Each server rack is cooled by the circulation of indoor air as described above.

Next, a high-temperature exhaust suction control flow of the rack type air conditioner 20 will be described with reference to FIG. The following control is performed by a command from the control unit 27 of each rack type air conditioner 20. In the thermo-ON operation state, the compressor 22b and the blower fan 24 are operating, and the shutter 25 is open (S101). As a result, high temperature exhaust gas is sucked into the indoor unit 21 from the hot aisle 6 b side, cooled by the evaporator 23, and then blown out to the cold aisle 6 a side by the blower fan 24 as cool air.
During this time, when the refrigerant circulation is stopped due to the thermo OFF or the failure of the refrigerant system (YES in S102), the operation of the blower fan 24 is stopped (S103), and the shutter 25 is further closed (S105). Thereby, the rapid temperature rise of the cold aisle 6a due to the introduction of the hot aisle 6b at high temperature exhaust can be avoided. Note that even if NO in S102, that is, the thermostat is ON and the refrigerant is circulating, the shutter 25 is also closed when the blower fan 24 is stopped due to a failure or the like (S104, S105). If the refrigerant evaporating temperature decreases with a decrease in the air volume, drainage may occur, but this can be prevented by closing the shutter. Thereafter, when the thermostat is turned on or returns from a failure, the compressor 22b and the blower fan 24 are operated and the shutter 25 is opened (S101).

In this embodiment, the shutter is opened / closed by electric drive, but may be opened / closed by spring drive. FIG. 5 shows such a form. FIG. 5A shows the operating state of the blower fan 24, and FIG. 5B shows the spatial position of the slat 71 in the stopped state. The slats 71 constituting the shutter 70 are pivotally connected to support rods 74 provided at both ends of the main body, and rods 74a passed to the 74. One end of a spring 72 is swingably connected to the upper portion of the slat 71. The other end of the spring 72 is swingably connected to a bracket 72 a provided on the main body back member 73. When the blower fan 24 is in the operating state, the slat 71 overcomes the pulling force of the spring by the fan suction force and is opened as shown in FIG. When the blower fan 24 is stopped, the slat 71 is closed by the pulling force of the spring as shown in FIG.
Furthermore, it is also possible to adopt a form that opens and closes by the weight of the slat without using a spring.
In this embodiment, an example in which the shutter is provided on the exhaust suction side has been described. However, the present invention is not limited to this, and the shutter may be provided on the cold air blowing side or inside the indoor unit (regardless of the front and rear of the evaporator).

(Second embodiment)
Furthermore, another embodiment of the present invention will be described. In this embodiment, a shutter is not used as the airflow blocking means, but the airflow from the hot aisle to the cold aisle is canceled by rotating the blower fan in the reverse direction.
FIG. 6 is a diagram illustrating a configuration of the rack-type air conditioner 30 according to the present embodiment. FIG. 7 is a diagram illustrating high-temperature exhaust air suction control of the rack-type air conditioner 30. FIG. 8 is a diagram showing the airflow direction in the thermo OFF state.
The configuration of the rack-type air conditioner 30 is different from the above-described rack-type air conditioner 20 in that the rear side of the indoor unit 31 is not provided with a shutter, and instead of this, an ultra-high air flow detection is provided in the vicinity of the exhaust suction portion 34. A sonic wind direction wind speed sensor 32 is provided. Further, the blower fan 33 is configured to be able to control the rotation direction in a freely reversible manner. Since other configurations are the same as those of the above-described embodiment, a duplicate description is omitted.

Next, a high-temperature exhaust suction control flow of the rack type air conditioner 30 will be described with reference to FIG. At the start of operation, in the thermo-ON state (compressor 22b operation) (S201), the blower fan 33 is operated in the forward rotation (S202). During this time, when the circulation of the refrigerant is stopped due to the thermo OFF or the failure of the refrigerant system (YES in S203), the wind direction wind speed in the vicinity of the suction portion 34 is measured by the wind direction wind speed sensor 32 (S204). When the measured value of the sensor 32 still indicates the airflow value from the hot aisle side to the cold aisle side (YES in S205), the blower fan 33 is operated in the reverse direction rotation (S206). In this case, the fan rotation speed is set to an air flow rate enough to cancel the airflow from the hot aisle side to the cold aisle side. FIG. 8 is a diagram schematically showing this state. Thereby, it is possible to avoid a rapid temperature rise of the cold aisle without sucking the hot exhaust gas of the hot aisle 6b. Thereafter, when the thermo-ON state is reached (YES in S207), the blower fan 33 is returned to the forward rotation (S202).
In the present embodiment, an ultrasonic sensor is used as the wind direction and wind speed sensor, but other sensors having the same functions as the ultrasonic type, such as a hot wire type and a propeller type, can be used.

(Third embodiment)
Furthermore, another embodiment of the present invention will be described. In the present embodiment, the differential pressure between the two aisles is used as a means for detecting the airflow from the hot aisle to the cold aisle side.
FIG. 9 is a diagram illustrating a configuration of the rack-type air conditioner 40 according to the embodiment. The configuration of the rack-type air conditioner 40 is different from the above-described rack-type air conditioner 30 in that the front side (cold aisle side) and the back side (hot aisle side) of the indoor unit 41 are replaced with the wind direction / air velocity sensor 32 for airflow detection. Are provided with pressure sensors 42 and 43, respectively. The detection values P1 and P2 of both pressure sensors are configured to be output to the control unit 27. Since other configurations are the same as those of the above-described embodiment, a duplicate description is omitted.

  Next, a high-temperature exhaust suction control flow of the rack type air conditioner 40 will be described with reference to FIG. At the start of operation, in the thermo-ON state (compressor 22b operation) (S301), the blower fan 44 is operated in the forward rotation (S302). During this control, when the refrigerant circulation stops due to the thermo OFF or the failure of the refrigerant system (YES in S303), the pressure sensors 42, 43 cause the front side (cold aisle side) and the back side (hot aisle side) of the indoor unit 41. The pressures P1 and P2 are measured (S304). When P2> P1 (YES in S305), it is determined that the hot aisle side pressure is high and the high temperature exhaust gas may flow into the cold aisle side. In this case, the blower fan 44 is operated in reverse rotation (S306). The fan rotation speed in this case is set to an air blowing amount that cancels out the airflow from the hot aisle side to the cold aisle side as in the second embodiment. Thereafter, when the thermo-ON state is reached (YES in S307), the blower fan 44 is returned to the forward rotation (S302).

(Fourth embodiment)
Furthermore, another embodiment of the present invention will be described. In this embodiment, the shutter is opened and closed by using a change in the differential pressure across the electronic expansion valve.
FIG. 11 is a diagram illustrating a main configuration of the indoor unit 51 of the rack-type air conditioner according to the embodiment. The configuration of the indoor unit 51 of the rack type air conditioner 50 is different from the indoor unit 21 according to the first embodiment in that a piston cylinder 59 is provided in parallel with the electronic expansion valve 56 between the refrigerant pipes 58a and 59b. It is. A link mechanism 59b is attached to the cylinder head 59a. Further, the link mechanism 59b and the shutter 55 are connected via a rod 55b so that the slat 55a can swing up and down. Since other configurations are the same as those of the above-described embodiment, a duplicate description is omitted.
With the above configuration, since P3> P4 in the thermo-ON state (during refrigerant circulation), the cylinder head 59a is pushed upward as shown in FIG. It becomes. On the other hand, in the thermo OFF state (when the refrigerant circulation is stopped), P3≈P4, so the cylinder head 59a is pushed downward and the slat 55a is closed as shown in FIG. In this way, the shutter 55 is closed when the thermo is OFF, and the inflow of high-temperature exhaust can be blocked.

  The present invention is widely applicable to an air conditioning system using a rack type air conditioner regardless of the type of heat source, refrigerant, air conditioning system, building structure, and the like.

It is a figure which shows the structure of the rack type air conditioner 20 which concerns on 1st embodiment. It is a figure which shows the cross-sectional structure of the air conditioning system 1 using the rack type air conditioner. 1 is a diagram illustrating a planar configuration of an air conditioning system 1. FIG. It is a figure which shows the high temperature exhaust_gas | exhaustion suction control flow of the rack type air conditioner. It is a figure which shows the form of shutter opening and closing by a spring drive. It is a figure which shows the structure of the rack type air conditioner 30 which concerns on 2nd embodiment. It is a figure which shows the high temperature exhaust_gas | exhaustion suction control flow of the rack type air conditioner. It is a figure which shows the airflow direction when the ventilation fan 33 is drive | operated by reverse direction rotation. It is a figure which shows the structure of the rack type air conditioner 40 which concerns on 3rd embodiment. It is a figure which shows the high temperature exhaust_gas | exhaustion suction control flow of the rack type air conditioner. It is a figure which shows the principal part structure of the indoor unit 51 of the rack type air conditioner 50 which concerns on 4th embodiment. 1 is a diagram showing a conventional rack air conditioning system 100. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rack air conditioning system 2 ... Server rack 3 ... Rack row 4 ... Ambient air conditioner 5 ... Information communication machine room 5b ... Ceiling space 5c ... Two Heavy floor space 5d ... floor panel 5e ... ceiling panel 5f ... perforated panel 6a ... cold aisle 6b ... hot aisle 20, 30, 40, 50 ... rack type air conditioner 24, 33, 44, 54 ... Blower fans 25, 55, 70 ... Shutter 25a ... Shutter box 25b, 55a, 71 ... Slats 26, 56 ... Electronic expansion valve 32 ... Ultrasonic wind direction wind speed sensor 42, 43 ... Pressure sensor

Claims (8)

A rack type air conditioner used in an indoor air conditioning system in which a cold aisle and a hot aisle are formed by a plurality of server rack rows,
A blower fan that sucks in hot exhaust on the hot aisle side and blows out cooling air to the cold aisle side;
An exhaust inflow control means for controlling inflow or shut-off of high temperature exhaust in conjunction with predetermined operating conditions ,
The predetermined operating condition is one or both of circulation or suspension of refrigerant, or operation or shutdown of the blower fan,
The exhaust inflow control means includes a high-temperature exhaust inflow shut-off shutter and the shutter opening / closing means.
A rack type air conditioner characterized by that. The rack type air conditioner according to claim 1 , wherein the shutter opening / closing means is configured to be opened by the suction force when the blower fan is operated and closed by gravity or a spring mechanism when the operation is stopped. Air Conditioning System is a refrigerant straight膨方formula, and the shutter opening and closing means, rack according to claim 1, characterized in that utilizes a differential pressure across the expansion valve provided in the refrigerant pipe passage air conditioner. The exhaust inflow control means comprises:
Airflow sensing means for sensing the direction of airflow in the aircraft;
Means for operating the blower fan in a direction opposite to the airflow direction sensed by the airflow sensing means;
Rack air conditioner according to claim 1, characterized in that it comprises a. The rack type air conditioner according to claim 4 , wherein the airflow sensing means is an anemometer arranged in the machine. The rack type air conditioner according to claim 4 , wherein the airflow sensing means is means for detecting a differential pressure between the front side and the back side of the machine body. The rack type air conditioner according to any one of claims 1 to 6, wherein the rack type air conditioner is configured in the same module as a 19-inch server rack. The rack-type air conditioner according to any one of claims 1 to 7, wherein the air-conditioning system uses a double floor blow-off air conditioner with an ambient air conditioner and a local air conditioner with a rack-type air conditioner. Machine.

Images