JP2011108022A - Air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for supplying cold air to each information processing apparatus stored in a rack in just proportion so that the cold air reaches the upper part of the rack at a temperature required for cooling the information processing apparatuses. <P>SOLUTION: This air conditioning system 1 includes an air conditioning unit 3 supplying cold air to an information processing apparatus chamber 6, a blowing port 9 blowing cold air, a generation amount adjusting means 5 adjusting the airflow of the cold air generated by the air conditioning unit 3 based on the temperature difference of the rack 2 having the largest temperature difference between the air flowing into the upper part and the air flowing into the lower part, of the racks 2 aligned in the information processing apparatus chamber 6 or based on the temperature difference and the temperature of the air flowing into the upper part of the rack 2 having the largest temperature difference, and a generation temperature adjusting means 5 adjusting the temperature of the cold air generated by air conditioning unit 3 based on the temperature of the air flowing into the upper part of the rack 2 having the largest temperature difference and the air flow of the cold air generated by air conditioning unit 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an air conditioning system.

  With the development of IT (Information Technology), the amount of heat generated by IT equipment is steadily increasing. Along with this, the power consumption of the air conditioning system for cooling the IT equipment is also increasing, and the development of air conditioning technology capable of efficiently cooling the IT equipment is being carried out.

  For example, Patent Document 1 discloses a technique for controlling the air volume of an exhaust fan attached to a rack according to the exhaust temperature of the server in order to reliably exhaust the heat of the server. Patent Document 2 discloses a technique for performing thermal management of a computer room by installing a plurality of temperature sensors in a machine room and controlling a floor fan (fan tile). Patent Document 3 discloses a rack management device that detects the temperature in the rack and controls the fan. Patent Document 4 discloses a technique for controlling the fan speed using the temperature in the unit, the equipment rack, or the enclosure. In Patent Document 5, the air volume of each server is calculated from the rotation speeds of a plurality of fans of the server, the air flow is detected together with the server position information, and the cooling in the data center is performed according to the air flow. An air flow distribution device and a ventilation system having a controller for controlling the air flow are disclosed. Patent Document 6 discloses a technique for controlling air recirculation by increasing / decreasing the amount of supplied air.

JP 2009-140421 A Special table 2008-538406 gazette JP 2002-319082 A Special table 2009-524253 gazette JP 2006-208000 A Special table 2007-505285 Japanese Patent No. 4294560

  In a large-scale information processing facility such as a data center, a large number of racks accommodating IT devices are arranged in an information processing device room. From the viewpoint of air conditioning efficiency, it is desirable that cool air is supplied to the IT equipment accommodated in these racks without excess or deficiency, and the energy consumption of the entire air conditioning system is kept to a minimum. However, since the flow of cool air in an air conditioning system that cools information processing equipment is easily affected by the installation state and operating state of IT equipment, to supply the cool air supplied to each IT equipment to the minimum necessary for each equipment. Advanced control is required. For this reason, many methods are used to prevent devices exceeding the allowable temperature from being generated by excessively supplying cool air against the energy saving and circulating in the information processing device room in the entire air conditioning system.

  The present invention has been made in view of such a problem, and the information processing equipment accommodated in the rack reaches the upper part of the rack at a temperature necessary for cooling the information processing equipment without excess or deficiency. It is an object of the present invention to provide a technique for supplying the product.

  In order to solve the above-described problems, in the present invention, among racks arranged in the information processing equipment room, the temperature difference of the rack having the largest temperature difference between the air flowing into the upper portion and the air flowing into the lower portion, or The amount of cool air generated by the air conditioning unit is adjusted based on the temperature difference and the temperature of the air flowing into the upper portion of the rack having the largest temperature difference.

  Specifically, the air conditioning system performs air conditioning in an information processing equipment room in which racks that contain information processing equipment are aligned, and includes an air conditioning unit that supplies cold air to the information processing equipment room, and a floor side of the information processing equipment room Alternatively, a temperature difference between an air outlet provided on the ceiling side through which cool air supplied by the air conditioning unit blows out and air flowing into the upper part and air flowing into the lower part of the racks arranged in the information processing equipment room Generation amount adjusting means for adjusting the air volume of the cold air generated by the air conditioning unit based on the temperature difference of the largest rack or the temperature difference and the temperature of the air flowing into the upper portion of the rack having the largest temperature difference And the cold air generated by the air conditioning unit based on the temperature of the air flowing into the upper part of the rack having the largest temperature difference and the air volume of the cold air generated by the air conditioning unit. Comprising a generation temperature adjusting means for adjusting the temperature, the.

  The air conditioning system is premised on air conditioning in an information processing equipment room in which racks whose airflow changes according to the load state and suction temperature of the information processing equipment are arranged. The rack accommodates information processing equipment, and the amount of cooling air changes according to the load state of the equipment. Air that cools these devices passes through the rack from the periphery of the rack and flows to the opposite side. For example, the air is sucked from the front of the rack and discharged to the back. The air passing through the rack flows by a cooling fan provided in the information processing apparatus main body or a cooling fan attached inside or outside the rack. Of the four side surfaces of the rack, the surface on the intake side of the rack row (in other words, the surface on the intake side of the IT equipment installed in the rack) and the surface on the exhaust side, which is the opposite side, are all over. It may be open and the other surface may be opened or closed by a plate-like member or the like, or may have a specific intake / exhaust port or the like. In the information processing equipment room, such racks are aligned so that at least one of the intake surface and the exhaust surface of the cooling air is aligned. The information processing equipment room is provided with a path for flowing cool air to at least one of the floor side and the ceiling side, and the cool air is blown out to each rack through this path.

  The air conditioning system is provided with an outlet from which cool air supplied from the air conditioning unit blows. Such an outlet is provided on the floor side or the ceiling side of the information processing equipment room, and cool air is provided to the intake surface of the rack. Therefore, depending on the amount of cool air blown out from this blow-out port, a temperature difference may occur between the air flowing into the upper portion of the rack and the air flowing into the lower portion. For example, when rack rows in which racks are arranged are arranged in parallel across a plurality of rows, the outlet is provided on the floor side or ceiling side of a passage formed between a pair of rack rows. To do.

  In the air conditioning system, the air volume of the cold air generated by the air conditioning unit is set to the maximum value of the temperature difference between the air flowing into the upper portion of each rack and the air flowing into the lower portion by the generated amount adjusting means, or the maximum value. And the temperature of the air flowing into the upper portion of the maximum rack. Further, in the air conditioning system, the temperature of the cold air generated by the air conditioning unit is determined by the generated temperature adjusting means, the temperature of the air flowing into the upper portion of the rack having the maximum temperature difference, and the air volume of the cold air generated by the air conditioning unit. Adjusted based on. For example, if the maximum temperature difference is reduced, the air volume is decreased, and if the temperature difference is widened, the air volume is increased. Furthermore, when the temperature of the air flowing into the upper part of the rack is low and the amount of cool air is small due to control, the cooling capacity is excessive, so the temperature of the cool air is raised.

  In this air conditioning system, since the air volume of the cool air of the air conditioning unit is adjusted based on the temperature difference between the air flowing into the upper part of the rack and the air flowing into the lower part, There is no shortage of cool air supplied to information processing equipment.

  The cool air supplied to each information processing device accommodated in the rack can be supplied so as to reach the upper part of the rack at a temperature necessary for cooling the information processing device without excess or deficiency. Furthermore, the supply of cold air eliminates the need for a shielding plate that prevents hot air from wrapping around the intake surface of the rack, reduces material costs and construction costs, eliminates the feeling of pressure on maintenance personnel, and increases the degree of freedom of work. be able to.

It is a block diagram of an air conditioning system. It is equipment arrangement drawing of an air-conditioning system. It is a figure which shows the positional relationship of a rack and a blower outlet. It is a flowchart of rotation speed control. It is a flowchart of temperature control. It is a figure which shows the change at the time of reducing the rotation speed of an electric fan. It is a figure which shows the change at the time of increasing the rotation speed of an electric fan. It is a state figure when a part of warm air is circulating. The graph which shows temperature distribution when a part of warm air is circulating. It is a state figure when the amount of blowing is excessive. It is a figure which shows the example of application of the air conditioning system in case a rack row | line | column is two rows. It is a block diagram of the air conditioning system in the case of supplying cold air from a ceiling.

  FIG. 1 is a configuration diagram of an air conditioning system 1. As shown in FIG. 1, the air conditioning system 1 is connected to a rack 2 in which IT devices (corresponding to information processing devices in the present invention) such as servers and communication devices for performing various arithmetic processes and database management are accommodated. An air conditioning unit 3 that generates cool air to be supplied, and a control device 5 that adjusts the rotational speed of the electric fan of the air conditioning unit 3 according to the temperature of the cold air flowing into the upper part and the lower part of the rack 2 are provided. The air conditioning unit 3 supplies cold air to the entire rack row.

  FIG. 2 is a device layout diagram of the air conditioning system 1. As shown in FIG. 2, the air conditioning system 1 is provided in a server room 6 in which a number of racks 2 are arranged. The air conditioning unit 3 installed on the floor 7 of the server room 6 is configured to send the air taken from the server room 6 into a space under the floor provided between the floor 7 and the concrete slab 8. .

  The air-conditioning unit 3 is a package cooler that incorporates a cooling coil and an electric fan. The air-conditioning unit 3 cools the air in the server room 6 by sucking air from an opening provided on the upper surface, and sends it to the space under the floor from the bottom outlet. The air conditioning unit 3 may be one in which a coil and a fan are housed in separate casings, and both are connected by a duct.

  FIG. 3 is a diagram showing the positional relationship between the rack 2 and the cold air outlet 9. As shown in FIG. 3, blowout ports 9 are provided on the floor surface in front of each rack 2. The blowout port 9 is an opening provided in the floor 7 of the server room 6 and is provided with a net-like grating so that a person or the like can pass through the air. In addition, each rack 2 is provided with a suction surface 10 for taking in air for cooling the IT equipment accommodated in the rack, and a discharge surface for discharging the taken-in air is provided on the back. . As described above, the passage having the air outlet 9 provided on the floor and the suction surface 10 of the rack 2 through which the cool air supplied to the rack 2 flows is called a cold aisle. Further, a passage adjacent to the cool air passage, in other words, a passage having the discharge surface of the rack 2 and flowing warm air exhausted from the rack 2 is referred to as hot aisle.

  Each rack 2 is provided with a cooling fan for cooling the IT equipment, and the intake / exhaust amount of each rack changes from moment to moment according to the load state and suction temperature of the IT equipment accommodated. In other words, the number of rotations of the cooling fan built in or attached to each IT device or the cooling fan mounted inside or outside the rack 2 changes according to the load state of the IT device, etc. The amount of air that is drawn into the suction surface 10 or discharged from the discharge surface changes. For this reason, the intake and exhaust amount of each rack may be different from each other. Therefore, it is necessary to adjust the blowout amount of the blowout port 9 appropriately without excess or deficiency according to the operating state of the IT device.

  Therefore, in the air conditioning system 1, the control device 5 performs the following control. FIG. 4 shows a flowchart of control performed by the control device 5 on the air conditioning unit 3. Hereinafter, the control performed by the control device 5 will be described based on the flowchart shown in FIG.

The control device 5 uses the upper temperature sensor 11 provided at the upper part of the suction surface 10 of each rack 2 and the lower temperature sensor 12 provided at the lower part to allow air to flow into the upper part and the lower part of each rack 2. Detect the temperature of The upper temperature sensor 11 and the lower temperature sensor 12 are provided at least on a flow path through which cool air for cooling the equipment in the rack passes and when a temperature difference is likely to occur between the two sensors when intake into the rack is insufficient. For example, it is installed around 100 mm from the upper end and the lower end of the intake mesh of the rack 2. Then, for each rack 2, a temperature difference ΔT (i) between the temperature of the air flowing into the upper portion and the temperature of the air flowing into the lower portion is calculated. Assuming that the temperature detected by each upper temperature sensor 11 is Tu (i) and the temperature detected by the lower temperature sensor 12 is Td (i), the temperature difference ΔT (i) is expressed by the following formula (1).
Formula (1): ΔT (i) = Tu (i) −Td (i)

  Here, i corresponds to the number of temperature sensors. In this embodiment, it is assumed that one upper temperature sensor 11 and one lower temperature sensor 12 are attached to each of eight racks. Is a natural number from 1 to 8. The upper limit value of i is appropriately determined according to the number of upper temperature sensors and lower temperature sensors.

  When the air conditioning system 1 is activated, the control device 5 compares the temperature difference ΔT (i) between the upper temperature and the lower temperature of each rack, as shown in FIG. 4A, and determines the maximum value of the temperature difference ΔT (i). A certain ΔT-max is determined (S101). In other words, ΔT-max is a temperature difference in a rack having the largest temperature difference ΔT in the rack row. Next, the control device 5 detects whether or not ΔT-max is equal to or less than the C value −α (S102). This C value is such that the air blown from the floor does not reach the suction surface 10 of the rack 2, and warm air from the other (for example, a part of the exhaust gas exhausted to the rear surface of the rack) on the suction surface 10 of the rack 2. This is a temperature difference that occurs when flowing into the upper part of each rack 2. In this embodiment, the control allowable value is 3 ° C., for example, in the allowable range of set value ± 3 ° C. Further, the α value is a dead zone in consideration of control stability, and is set to 1 ° C. in this embodiment. These values differ depending on the IT equipment accommodated in the rack.

  When it is determined in the process of S101 that the temperature difference ΔT-max is equal to or lower than (C−α), the control device 5 detects whether the upper temperature is equal to or lower than the Tsp value (S103). This Tsp value is a value close to the set value of the suction temperature of the IT equipment. When the IT equipment changes the air flow rate according to the suction temperature, the air volume of the cool air is adjusted according to this to the rack. Cool air is supplied without excess or deficiency. In this embodiment, the temperature is 25 ° C. This value varies depending on the type and manufacturer of the IT equipment accommodated in the rack.

When the upper temperature Tu (i) is equal to or lower than Tsp, the control device 5 determines that the cooling air to the rack is excessive, and decreases the rotational speed (rotational speed) per unit time of the electric fan of the air conditioning unit 3 by δ. (S106). The rotational speed of the electric fan is adjusted by changing the frequency of the inverter that supplies power to the electric motor that drives the fan. As a result, as shown in FIG. 5A, the amount of cool air blown out from the blowout port 9, which is generally excessive in air volume, is reduced. Further, if ΔT-max is not (C−α) or less (S102) and is (C + α) or more (S104) and the upper temperature Tu (i) is Tsp or more (S105), the air flow to the rack is insufficient. Therefore, the rotational speed N of the electric fan of the air conditioning unit 3 is increased by δ (S108). If it is determined to be false in S103, S104, and S105, it is determined that the airflow to each rack is appropriate, and the rotational speed N of the electric fan is left as it is (S107). Thus, from ΔT-max and Tu (i), the rotational speed of the electric fan decreases when overcooling is determined, and the rotational speed of the electric fan is increased when insufficient cooling is determined. Thus, the number of revolutions is sufficient for the electric fan to cool the IT equipment in each rack. When the electric fan is driven by a DC motor, the number of rotations can be controlled by adjusting the applied voltage or voltage pulse.

Further, as shown in FIG. 4B, the control device 5 detects whether or not the upper temperature Tu (i) of the rack having the maximum value of the temperature difference is equal to or lower than the T− _L value (S201). The _TL value is a temperature at which it is determined that the cold air necessary for cooling the IT equipment is too cold. If the temperature is equal to or lower than this temperature, the air conditioning unit 3 determines that excessive energy is consumed to generate the cold air. . In this embodiment, the temperature is set to 16 ° C. This value differs depending on the IT equipment accommodated in the rack.

When the upper temperature Tu (i) is equal to or lower than the T- _L value (a value for determining that cooling is still required after exceeding the limit of the fan of the air conditioning unit 3), the rotational speed N of the electric fan of the air conditioning unit 3 is D It is detected whether the value is equal to or less than the value (S202). This D value is a value for determining the excessive amount of cold air generated by the air conditioning unit 3, and is 20% in this embodiment. When the rotational speed of the electric fan is equal to or less than the D value, it is determined that the capacity of the cool air is excessive, and the control device 5 increases the temperature of the cool air generated by the air conditioning unit 3 by θ (S205). Further, the rack upper temperature Tu (i) is equal to or higher than the _TH value (a value for determining that the supply air is still excessive even if the supply amount to the rack 2 is the minimum, for example, 27 ° C.). (S203), and the rotational speed of the electric fan of the air conditioning unit 3 is equal to or higher than the E value (for example, 20%) (S204), the control device 5 has a cooling capacity of the cold air generated by the air conditioning unit 3. It is determined that the temperature is insufficient, and the temperature of the generated cold air is lowered by θ (S207). If these determinations are false, it is determined that the cooling capacity of the cold air is appropriate, and the temperature of the cold air is left as it is (S206).

Note that ΔT (i), Tu (i), ΔT-max, T- _L value, and T- _H value fluctuate depending on the operating status of the information processing device even if the air volume and supply temperature of the air conditioning unit are the same, that is, high In the case of a load, the temperature of the hot exhaust gas is high and the amount is large, whereas in the case of a low load, they are low and low.

According to the air conditioning system 1 configured in this manner, the number of rotations of the electric fan of the air conditioning unit 3 can be minimized without running out of cool air supplied to the IT equipment accommodated in each rack. It is possible to increase the air conditioning efficiency by suppressing the energy consumption of the entire air conditioning system. That is, when trying to minimize the number of revolutions of the electric fan of the air conditioning unit 3 without being based on the temperature of the air flowing into the upper part of the rack and the temperature of the air flowing into the lower part as in the air conditioning system 1, for example, As shown in FIG. 6A, there is a possibility that a part of the warm air exhausted from the rack may circulate to the intake side due to insufficient amount of cool air from the air outlet 9. FIG. 6B is a graph showing the suction temperature of the rack when the amount of cool air blown from the floor is insufficient. As shown in FIG. 6B, it can be seen that when the amount of cool air blown from the floor is insufficient, the suction temperature of the upper portion is higher than that of the lower portion of the rack. In order to prevent such warm air from flowing in, the rotational speed of the electric fan of the air conditioning unit 3 is controlled based on the temperature of the air flowing into the upper part of the rack and the temperature of the air flowing into the lower part. As shown, it is unavoidably necessary to set the overall blowing amount excessively. Setting the overall blowout amount in this way can prevent a specific IT device from overheating, but causes a reduction in the air conditioning efficiency of the entire air conditioning system. However, if the rotational speed of the electric fan of the air conditioning unit 3 is controlled based on the temperature of the air flowing into the upper part of the rack and the temperature of the air flowing into the lower part as in the air conditioning system 1, There is no shortage of cold supplied. Furthermore, if the number of rotations of the electric fan of the air conditioning unit 3 is controlled based on the temperature flowing into the upper part of the rack, the cool air can be supplied to the rack without any excess or deficiency. Also, if the temperature of the cool air generated by the air conditioning unit is adjusted according to the temperature flowing into the upper part of the rack and the rotation speed of the electric fan of the air conditioning unit, the cool air with excessive cooling capacity can be generated and supplied. Can prevent the loss of energy required.

  In order to reliably catch such a lack of cool air in the rack with the upper temperature sensor 11 and the lower temperature sensor 12, a blank panel is installed in the gap in the rack, and the backflow of warm air does not occur in the gap in the rack. It is more preferable to do so. If the wraparound of warm air in the rack is sealed with a blank panel, the route in which the warm air flows back will go from the back of the rack to the upper side, and the temperature of the cold air sucked into the upper part of the rack and the cold air sucked into the lower part This is because the difference becomes prominent.

  Moreover, in the process of step S106 mentioned above, you may make it restrict | limit the lower limit of the rotation speed of an electric fan so that it may not fall below predetermined minimum air volume. The predetermined minimum air volume is the minimum air volume to be supplied to each rack even when there is no temperature difference between the air flowing into the upper part of each rack and the air flowing into the lower part. The air volume is such that the heat generation amount of the operating equipment among all the IT equipment accommodated in each rack can be removed at a minimum. Such air volume may be determined at any time by sensing, for example, the power consumption and room temperature of all IT devices, the temperature of the air flowing into the air conditioning unit 3, or the like, and is determined in advance that does not vary depending on these parameters. It may be a fixed value.

  By the way, the air conditioning system 1 can be modified as follows. For example, the air conditioning system 1 may be applied not only to the case where the rack row is one row, but also to the two rows as shown in FIG. . As shown in FIG. 8, when there are two rack rows, the air intake surfaces of the rack rows face each other so that a cold aisle is formed between the two rack rows. Then, a grating is installed on the floor of the cold aisle to serve as a blowout port. The air conditioning system disclosed in the present application can be applied to a server room having a plurality of rack rows as described above, and the rotational speed of the electric fan of the air conditioning unit 3 and the generation temperature of the cold air are shown in the flowcharts of FIGS. 4A and 4B. By controlling in this way, a sufficient amount of cold air necessary for cooling the IT equipment in the rack is supplied from the air conditioning unit, and air conditioning efficiency is increased.

  Moreover, in the said air conditioning system 1, although cold air was supplied from under the floor, it can also be supplied from a ceiling, for example. FIG. 9 is a configuration diagram of the air conditioning system 1 in the case of supplying cold air from the ceiling. As shown in FIG. 9, when the cold air is blown out from the ceiling, the duct 13 in which the cold air flows (the interior of the ceiling may be a so-called ceiling chamber and the duct may be omitted) and the duct 14 in which the warm air flows (see FIG. 2). Similarly, the space in the server room may be omitted as a return air path). The control method described in FIG. 4A to FIG. 4B can be implemented as a ceiling blow-out type air conditioning system by applying the knowledge of those skilled in the art by replacing “upper part” with “lower part”. Even in the air conditioning system 1 configured as described above, a sufficient amount of cold air necessary to cool the IT equipment in the rack is supplied from the air conditioning unit, and air conditioning efficiency is improved.

The air conditioning system 1 can be realized not only as a newly installed facility but also by modifying an existing air conditioning system. For example, when an air conditioning system in which only the air conditioning unit 3 is provided is provided, the air conditioning system 1 can be realized only by newly providing the upper temperature sensor 11, the lower temperature sensor 12, and the control device 5. Therefore, versatility and practicality are extremely high.

DESCRIPTION OF SYMBOLS 1 ... Air conditioning system 2 ... Rack 3 ... Air conditioning unit 5 ... Control device 6 ... Server room 7 ... Floor 8 ... Concrete slab 9 ... Outlet 10 ... Suction Surface 11 .. Upper temperature sensor 12 .. Lower temperature sensor 13, 14 .. Duct

Claims (3)

An air conditioning system for air conditioning an information processing equipment room in which racks containing information processing equipment are arranged,
An air conditioning unit for supplying cold air to the information processing equipment room;
A blow-out port from which cool air supplied by the air-conditioning unit is provided on the floor side or ceiling side of the information processing equipment room;
Of the racks arranged in the information processing equipment room, the temperature difference of the rack having the largest temperature difference between the air flowing into the upper portion and the air flowing into the lower portion, or the rack having the largest temperature difference and the temperature difference. Generation amount adjusting means for adjusting the air volume of the cold air generated by the air conditioning unit based on the temperature of the air flowing into the upper portion of
Generated temperature adjusting means for adjusting the temperature of the cold air generated by the air conditioning unit based on the temperature of the air flowing into the upper part of the rack having the largest temperature difference and the air volume of the cold air generated by the air conditioning unit. ,
Air conditioning system. When the temperature difference of the rack having the largest temperature difference between the air flowing into the upper portion and the air flowing into the lower portion of the racks arranged in the information processing equipment room is widened, the generation amount adjusting means Increases the air volume of the cool air generated by the air conditioning unit, and reduces the air volume of the cool air generated by the air conditioning unit when the temperature difference is reduced.
The air conditioning system according to claim 1. In the information processing equipment room, rack rows in which racks are arranged are arranged in parallel over a plurality of rows,
The outlet is provided on the floor side or ceiling side of a passage formed between a pair of rack rows.
The air conditioning system according to claim 1 or 2.

Images