JP2002061911A - Method for cooling computer room - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the volume of circulating air and, at the same time, the quantity of refrigerant used by a refrigerating machine at the time of cooling a high-density computer room by circulating the air. SOLUTION: Air-conditioned air from an air-conditioner 3 is blown into the computer room R at a low speed from a space under the floor through a supply air duct 4. The exhaust air from the room R is collected from the ceiling section of the room R and its vicinity through a return air duct 9 and returned to the air conditioner 9. The exhaust air returned to the air conditioner 3 is again supplied as air-conditioned air after the air is successively cooled by means of cooling coils 11 and 12. The temperature of the air-conditioned air is adjusted so that the temperature difference between the outlet temperature of the supply air duct 4 and the inlet temperature of the return air duct 9 becomes 15-25 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cooling a computer room, particularly a computer room having a high density and a high load, which is called a computer center. is there.

[0002]

2. Description of the Related Art Computers, that is, electronic computers (computer devices) are installed in a room (so-called computer room) maintained at a constant temperature in order to operate stably. In this case, since the computer generates high heat, the computer room is operated for cooling throughout the four seasons. However, since the computer center operates continuously for 24 hours,
Large amounts of energy are consumed. Therefore, cooling methods and cooling apparatuses aiming at energy saving effects have been proposed.

[0003] For example, Japanese Patent No. 1979061 discloses that
A two-stage heat exchanger is installed in the indoor unit, the rear heat exchanger is always operated by the refrigerator, and the front heat exchanger is operated by the refrigerator or the cooling tower so that the water circulation system can be switched. A formed natural cooling air conditioner has been proposed. Thus, when the temperature of the outside air is lower than that of the indoor air, energy is saved by the action of the gas-liquid contact between the outside air and the cooling water.

[0004]

However, the conventional method has a very large circulating air flow from the viewpoint of computer protection.
In addition, the difference in the outlet temperature between the supply air and the return air used for the return air is very small. For example, conventionally, the temperature of the supply air (the outlet temperature of the supply air duct) is 18 ° C. to 20 ° C., and the temperature of the return air (the inlet temperature of the return air duct) is about 23 ° C. to 25 ° C. The temperature difference is about 7 ° C. For this reason, the return air volume is also set large, for example, about 300 m ³ /
H · m ² .

In recent high-density computer rooms, that is, rooms in which a large number of computers are installed in a space, the ceiling height is designed to be about 4 m, which is 30% or more higher than in the past. 2. Description of the Related Art Computer devices having a high overall height and computer devices configured to be stacked in multiple stages on racks are arranged at high density.

Therefore, if it is attempted to cool the high-density computer room by the conventional method, the conditioned air must be supplied and returned with an extremely large amount of air, and as a result, the amount of circulating air increases. As a result, the air conditioning equipment had to be enlarged. The temperature of the air discharged from the computer room is at most about 25 ° C., which is lower than the outside air in summer, so that the heat generated in the room cannot be discharged into the outside air. There was a problem that the outside air cooling effect using the outside air in the season and winter was small, and the application period was short.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and focuses on the serviceable temperature characteristics of recent computer devices, thereby greatly reducing the amount of circulating air and reducing the size of cooling air circulation equipment and the like. It is intended for.

[0008]

According to a first aspect of the present invention, a room in which a computer is installed is supplied with conditioned air from an air conditioner, and return air from the room is supplied to the air conditioner. A method for cooling a computer room, comprising a cooling air circulation system for returning to an apparatus and treating the air again,
The temperature is set to 15 ° C. to 25 ° C. lower than the service temperature of the computer, and the blowing speed of the conditioned air is set to a low speed to blow out from the lower part of the room into the room, and further from the vicinity of the ceiling of the room. A method for cooling a computer room is provided, wherein air is returned.

[0009] The durable temperature of recent computer devices is about 40 ° C. A so-called stratified air conditioner, in which supply air is blown into the room from below at a low speed and air is returned from the ceiling, is suitable as an air conditioning method for suppressing the amount of circulating air when air conditioning a room with a large amount of heat. According to the knowledge of the above, if the highest temperature portion in the computer room, that is, the temperature near the ceiling is suppressed to a maximum of about 40 ° C. to 45 ° C., there is no hindrance to the operation of the computer. For a high-density computer room having a height of about 4 m, for example, 0.1 m / s to
The conditioned air is blown from below at a low speed of 0.6 m / s, for example, from the floor (when blown from below the side of the room, it is blown from the floor at 0.1 m / s to 0.6 m / s). 0.25 m / s or less in this case), and a temperature 15 ° C. to 25 ° C. lower than the service temperature, that is,
It has been found that if the temperature of the supply air is set to about 25 ° C. to 25 ° C. and supplied to the computer room, the temperature of the return air from the ceiling can be suppressed to 40 ° C. This temperature is higher than the outside air temperature in summer. Therefore, the generated heat can be radiated to the outside air without hindering the operation of the computer and even in the summer. Also, as described above, the so-called stratified air conditioning can be performed on the computer room by setting the blowing air velocity of the conditioned air to a low speed of, for example, 0.1 m / s to 0.6 m / s. It is possible to perform air-conditioning without unevenness as a whole without causing local stagnation of high-temperature air. And the ventilation rate is 100
The number of times per hour was about 20 times / h to about 50 times / h, which also confirms the energy saving effect.

According to another aspect of the present invention, as described in claim 2, conditioned air from an air conditioner is supplied to a room in which a computer is installed, and return air from the room is supplied to the air conditioner. A cooling method for a computer room, comprising a cooling air circulation system for returning to a room and processing again, wherein an outlet temperature of an air supply duct for supplying air-conditioned air to the room and stagnant air near a ceiling of the room are discharged. Temperature difference from the return air duct inlet temperature is 1
A method for cooling a computer room is provided, wherein the temperature of the air-conditioned air is adjusted to be 5 ° C. to 25 ° C.

As described above, conventionally, the cooling of the computer room was performed in a state where the temperature difference between the supply air and the return air was small.
It required a large amount of cooling air circulation. Therefore,
By making such a temperature difference as large as 15 ° C. to 25 ° C., the supply air volume, return air volume,
That is, the amount of air circulation air can be significantly reduced.

In the cooling method, the cooling air circulating system may be provided with a pollutant regulated by law except during the daytime in summer (usually when other ordinary living rooms are being cooled). Outside air may be introduced in excess of the outside air introduction amount necessary to achieve the allowable concentration of the substance. According to a fourth aspect of the present invention, during the daytime in summer, outside air may be introduced into the cooling air circulation system in excess of the outside air introduction amount necessary to achieve the allowable concentration of pollutants specified by laws and regulations. . The permissible concentration of pollutants specified by laws and regulations here refers to those listed in Article 2 of the Ordinance for Enforcement of the Law Concerning Sanitary Environment in Buildings (so-called Building Management Law). As mentioned above, since the return air from the computer room is about 40 ° C, the temperature is higher than the outside air, and conversely, the outside air should be more actively taken into the circulation system than required by law. ， It is possible to actively use the outside air for cooling. Therefore, the outside air cooling usage period is possible throughout the four seasons, and effective use of energy can be achieved.

[0013] The configuration of the air conditioner for performing the above cooling method has a cooling coil using a refrigerant from a refrigerator, and the condenser of the refrigerator is a cooling tower. In the cooling air circulation system, heat is exchanged between the return air from the chamber and a cooler provided for pre-cooling using cooling water from a cooling tower. After that, if the processing is performed by the cooling coil, it is possible to reduce the capacity of the refrigerator and the operating cost. Note that the refrigerant includes not only cold water but also a phase-change refrigerant such as CFC-based gas. The cooling water used in the cooler provided for pre-cooling using the cooling water from the cooling tower may be the same as the cooling water for cooling the condenser of the refrigerator, It may be cooling water from another cooling tower.

According to a sixth aspect of the present invention, in the cooling air circulation system, the return air from the chamber is brought into contact with one end of a heat pipe, then returned to the air conditioner, and then cooled by a cooling coil or the like. By arranging the other end of the heat pipe in a cooling section in a cooling tower for cooling, the capacity of the cooling coil and the like can be reduced. In this case, for example, an evaporative cooling tower can be used.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described. FIG. 1 shows an outline of a system of an air conditioner for performing a cooling method according to a first embodiment of the present invention. High-density computer room R to be cooled
Inside, a large number of computer devices 1 are arranged in multiple stages. An underfloor chamber 2 is provided under the floor of the computer room R, and the conditioned air supplied from the air conditioner 3 through the air supply duct 4 into the underfloor chamber 2 from the air supply port 5 is supplied to the floor formed on the floor surface. The air is blown from the outlet 6 into the computer room R at a low speed.

On the other hand, on the ceiling of the computer room R, a ceiling chamber 7 is provided between a ceiling board having an opening such as a slit and a frame ceiling, and air near the ceiling is returned to a return air duct 9.
, And is returned from the return air duct 9 to the air conditioner 3 as return air. Therefore,
The air conditioner 3, the air supply duct 4, the computer room R and the return air duct 9 constitute a cooling air circulation system.

The air conditioner 3 is provided with a first
The cooling coil 11 (corresponding to the cooler in claim 4) which is the heat exchanger of the first embodiment, and the cooling coil 1 which is the second heat exchanger
2, and an air blower 13, and after the air primarily cooled by the cooling coil 11 is secondarily cooled by the cooling coil 12, the air-conditioned air purified by the blower 13 through an appropriate filter (not shown) To the air supply duct 4. The outside air is introduced into the air conditioner 3 from the outside air intake duct 14 together with the return air from the computer room R returned through the return air duct 9, and the air is exhausted (exhausted from the exhaust duct (not shown) to the outside of the building). After being supplemented and mixed with the return air, the cooling air is processed by the cooling coils 11 and 12. Although illustration is omitted, for workers working in the computer room, the introduction of fresh outside air and the discharge of contaminated air are regulated by laws and regulations, and exhaust ducts, exhaust fans, motor dampers, etc. A displacement adjusting mechanism is separately provided.

The cooling coil 12 in the latter stage is connected to the air that has been primarily cooled by the cooling coil 11 and the refrigerator 21.
Heat is exchanged with the refrigerant (cold water or chlorofluorocarbon-based refrigerant). Cooling of the condenser of the refrigerator 21 is performed by cooling water from the cooling tower 31. That is, the heated cooling water from the refrigerator 21 is sent to the cooling tower 31 through the outgoing pipe 32, cooled by the cooling tower 31, and then returned to the refrigerator 2 through the return pipe 34 by the pump 33.
It is returned to 1 to cool the condenser.

The cooling coil 11 on the front stage side is provided with a return air from the computer room R introduced into the air conditioner 3 and a mixed air with the outside air to make up for the loss and the cooling water from the cooling tower 31. It has a configuration that cools the introduced air by exchanging heat between them. That is, in the cooling tower 31, the latent heat of evaporation is deprived by spraying the cooling water, and the cooling water is cooled to a temperature lower than the air temperature. Therefore, the outgoing pipe 34 is connected to the cooling coil 11.
And a branch return pipe 36 connected to the return pipe 32, and the cooling water heated by the heat exchange in the cooling coil 11 is supplied to the branch return pipe 36, the return pipe. 3
The cooling water sent to the cooling tower 31 through the cooling pipe 2 and cooled in the cooling tower 31 is returned to the cooling coil 11 through the forward pipe 34 and the branch forward pipe 35. Although the cooling coil 11 in the former stage and the cooling coil 12 in the latter stage are both housed in one air conditioner, each may be housed in a coil casing and they may be connected in series. The same applies to the blower, and it may be located on the upstream side of the preceding coil. That is, the air-conditioning equipment does not necessarily have to be housed in one unit, and it is sufficient that the air-conditioning equipment functions as one air-conditioning apparatus as a whole even if it is apparently dispersed in many units. Therefore, they are referred to as air conditioners in this specification.

Main equipment for carrying out the method for cooling a computer room according to the first embodiment is configured as described above. Next, the operation method will be described. For example, when the service temperature of the computer device 1 installed in the computer room R is 40 ° C., the temperature of the conditioned air supplied into the underfloor chamber 2 through the air supply duct 4 is discharged from the return air duct 9. For example, 20 ° C. is set so that the return air temperature of the computer room R is 45 ° C.

The inlet temperature of the return air duct 9 and the supply air duct 4
If the temperature difference from the outlet temperature is set to be as large as 20 ° C., the supply air volume is about 100 m ³ / H · m ² ,
Only about 1/3 of the conventional size is required. At this time, even if the effective blowing area is 1/2, the blowing wind speed from the floor surface is 0.
This is 1 m / s or less, whereby an air layer is formed from the low temperature to the high temperature gradually from the floor to the ceiling of the computer room R, and so-called stratified air conditioning is performed. By the way, in the case of a full opening on the floor surface, it may be 0.55 m / s or less, and eventually the blowing wind speed is reduced or increased depending on the width of the effective blowing area.

From the above, the amount of air flowing through the air circulation system and the like is greatly reduced as compared with the conventional case, and the air supply duct 4, the return air duct 9, the blower 13 and the like can be downsized. is there. A cooling coil 11 for performing primary cooling;
The use amount of the refrigerant can be reduced by the pre-cooling of the circulating air, and the refrigerator 31 can be of a small size, and the operating cost can be reduced.

In the above-described embodiment, the outside air introduced into the air conditioner 3 is only a supplement for the loss (the amount exhausted from the exhaust duct (not shown) to the outside of the building).
Although it was a pure circulation type cooling operation that was sufficient to achieve the allowable concentration specified in the Building Management Law, the temperature of the air flowing through the return air duct 9 was 40 ° C., which is significantly higher than before. In summer, it can be proposed to release this gas to the outside air as it is, while taking in the outside air and performing operation using outside air cooling.

FIG. 2 shows an outline of a system of an air conditioner for performing the method for cooling a computer room according to the second embodiment. Compared with the configuration of FIG. Points have been added. In the system examples shown in FIG. 2 and subsequent figures, the same members and devices are denoted by the same reference numerals, and redundant description is omitted.

That is, in the example shown in FIG. 2, a discharge duct 41 that branches off in the middle of the return air duct 9 is connected, and the discharge duct 41 is connected to the variable damper D ₁ and the return air duct 9 downstream from the branch.
Variable damper D _2, is provided with a variable damper D ₃ to the outside air intake duct 14 for drawing outside air to the air conditioner 3 in. Reference numeral 42 denotes a return air blower interposed in the return air duct 9.

When the cooling operation is performed, the variable dampers D ₁ , D ₂ , D ₃ are operated to compensate for the amount of air discharged from the discharge duct 41 to the outside air through the outside air intake duct 14 so that the air circulation is performed. Introduce fresh air into the system. In this case, as described above, since the temperature of the air flowing through the return air duct 9 is about 40 ° C., even in the summer, the air is discharged directly to the outside air through the discharge duct 41, and a corresponding amount of the outside air is discharged. Intake through duct 14. As described above, the cooling operation using the outside air can be performed not only in the winter season but also in the middle season and also in the summer season, and it is possible to perform the cooling operation in which the outside air cooling effect is large and the application period is long.

In the first embodiment, the cooling coil 11 for exchanging heat with the cooling water from the cooling tower 31 is used when the processing air is primarily cooled in the air conditioner 3. Instead, as in the third embodiment using the system shown in FIG. 3, cooling may be performed by the heat pipe 51 in the cooling tower 52 provided with the heat pipe 51.

That is, the cooling tower 52 has therein a processing space 54 partitioned by a partition wall 53 and a cooling space 55 as a cooling unit. The heat pipe 51 includes the processing space 54 and the cooling space 55. And straddling it. In the cooling space 55, the cooling water circulated by the pump 56 is sprayed on the upper part of the heat pipe 51, and cools the target processing air in the processing space 54 to form the heat pipe 5.
The refrigerant evaporated in 1 is cooled by the outside air and the latent heat of vaporization of the spray water and condensed again.

The high-temperature return air sent through the return air duct 9 contacts the heat pipe 51 in the processing space 54 of the cooling tower 52 to be cooled, and then is introduced into the air conditioner 3 through the duct 57. , And secondary cooling by the cooling coil 12.

As described above, when the high-temperature return air (exhaust) from the return air duct 9 is primarily cooled by the heat pipe 51 in the processing space 54 of the cooling tower 52, the load carried by the refrigerant supplied to the cooling coil 12 is reduced. Can be reduced. Therefore,
It is possible to reduce the operating cost by reducing the size of the refrigerator that supplies the refrigerant, shortening the operation time, and cooling only the shortage in the cooler.

In such a case, as in the fourth embodiment using the system shown in FIG. 4, a discharge duct 41 for discharging return air into the outside air is provided in the air circulation system, and the outdoor duct is actively used. To the outside air intake duct 14
You may make it take in outside air from.

That is, a branched discharge duct 41 is provided in the middle of the return air duct 9, and the variable damper D ₁ is provided in the discharge duct 41 and the variable damper D is provided in the return air duct 9 downstream from the branch portion.
_2, the variable damper _{D 3} provided in the outside air intake duct 14 for drawing outside air to the air conditioner 3, optionally with operating the variable damper _{D 1,} D 2, _{D 3,} blower 4
2 is operated, and a part of the return air from the return air duct 9 is directly discharged from the discharge duct 41 into the outside air. On the other hand, the discharged amount is introduced into the air conditioner 3 from the outside air intake duct 14. According to the cooling operation, as in the second embodiment described above, the cooling operation using the outside air by always taking in the outside air into the circulation system can be performed even in the summer season.

[0033]

According to the present invention, in particular, when cooling a high-density, high-load computer room by the air circulation system, the cooling can be performed with a smaller air volume than in the past. Accordingly, the necessary equipment can be reduced in size accordingly. In particular, in the case of claim 3, the outside air can be effectively used throughout the four seasons. In the case of claims 4 and 5, the amount of chilled water and refrigerant used can be reduced, and the size of the refrigerator can be reduced. Can be driven with

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing the configuration of a system for implementing a cooling method according to a first embodiment of the present invention.

FIG. 2 is an explanatory view schematically showing a configuration of a system for performing a cooling method according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram schematically showing the configuration of a system for performing a cooling method according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram schematically showing a configuration of a system for performing a cooling method according to a fourth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 computer device 3 air conditioner 4 air supply duct 9 return air duct 11, 12 cooling coil 21 refrigerator 31 cooling tower

Claims (6)

[Claims] 1. A computer room having a cooling air circulation system for supplying air-conditioned air from an air conditioner to a room in which a computer is installed and returning return air from the room to the air conditioner for processing again. A cooling method, wherein the blow-out temperature of the conditioned air is set to a temperature 15 ° C. to 25 ° C. lower than the service temperature of the computer, and the blow-out wind speed of the conditioned air is set to a low speed from below the chamber. A method for cooling a computer room, comprising: blowing air into the room; and removing air from the vicinity of a ceiling of the room. 2. A computer room having a cooling air circulation system for supplying air-conditioned air from an air conditioner to a room in which a computer is installed and returning return air from the room to the air conditioner for processing again. A cooling method, wherein a temperature difference between an outlet temperature of an air supply duct for supplying conditioned air to the room and an inlet temperature of a return air duct for discharging stagnant air near a ceiling of the room is 1
A method for cooling a computer room, comprising adjusting the temperature of the air-conditioned air to be in the range of 5 ° C to 25 ° C. 3. Except during the daytime in summer, outside air is introduced into the cooling air circulation system in excess of the amount of outside air required to achieve an allowable concentration of pollutants specified by laws and regulations. The method for cooling a computer room according to claim 1. 4. The cooling air circulation system according to claim 1, wherein outside air is introduced into said cooling air circulation system in an amount exceeding an outside air introduction amount required to achieve an allowable concentration of pollutants specified by regulations. 3. The method for cooling a computer room according to 1 or 2. 5. The air conditioner has a cooling coil that uses a refrigerant from a refrigerator, a condenser of the refrigerator is cooled by cooling water from a cooling tower, and the cooling air circulation 2. The system according to claim 1, wherein the return air from the chamber is heat-exchanged by a cooler provided for pre-cooling using cooling water from a cooling tower, and then processed by the cooling coil. , 2, 3 or 4. 6. In the cooling air circulation system, the return air from the chamber is brought into contact with one end of a heat pipe and then returned to the air conditioner for processing, and the other end of the heat pipe is used for cooling the cooling tower. The method for cooling a computer room according to any one of claims 1, 2, 3, and 4, wherein the method is arranged inside a computer.