JP4914800B2 - Electronic equipment cooling device - Google Patents

Description

  The present invention relates to an electronic device cooling apparatus that cools air blown by a fan attached to an electronic device housed in a cabinet.

2. Description of the Related Art Conventionally, there is known an electronic device cooling device that cools air blown by a fan attached to an electronic device housed in a cabinet with cooling water and returns the air to the room (for example, see Patent Document 1). Generally, this electronic device cooling apparatus is installed in a computer room, and cools a server or a network device installed in the computer room. In this type of electronic device cooling apparatus, a device provided with a heater for controlling humidity in the cabinet and a moisture absorbing / releasing material has been proposed (for example, see Patent Document 2).
US Patent Application Publication No. 2006/0232945 JP-A-8-316676

  By the way, the computer room is generally managed at a constant humidity and a constant temperature, and it is also necessary to prevent dew condensation because electronic devices dislike water. However, since the conventional electronic device cooling apparatus is provided with a heater for controlling humidity and a moisture absorbing / releasing material, the number of components increases. In addition, since the conventional device uses cooling water in the vicinity of the electronic device, strict measures against water leakage are required.

  Therefore, an object of the present invention is to provide an electronic device cooling apparatus capable of preventing condensation with a simple configuration.

In order to solve the above-described problems, the present invention is connected to a heat source unit having a compressor and a condenser, and a refrigerant pipe extending from the heat source unit, and closes an opening of a cabinet containing a fan-equipped electronic device. A refrigerating cycle is constituted by an evaporator disposed on a rear door, the cabinet is disposed in a computer room, and air blown by a fan attached to the electronic device is cooled by the evaporator of the rear door to be a computer The computer room includes a means for detecting a room temperature of the computer room and a waste heat temperature detecting means for detecting a waste heat temperature of the electronic device, and the room temperature of the computer room is defined by the computer room. If set exhaust heat temperature below the evaporator no condensation, close the expansion valve of the evaporator, the indoor temperature is the set exhaust heat Above the degrees, to compare the set exhaust heat temperature threshold plus server exhaust heat shift value and said exhaust heat temperature, the exhaust heat temperature is higher than the threshold value, the evaporator expansion valve And a control means for closing the expansion valve of the evaporator when the exhaust heat temperature is lower than the threshold value .

  According to the present invention, when the exhaust heat temperature of the electronic device is equal to or lower than the set exhaust heat temperature at which the evaporator specified in the computer room does not condense, the refrigerant supply to the evaporator is stopped and the exhaust heat temperature is set to the set exhaust heat temperature. When the temperature exceeds the heat temperature, supply of the refrigerant to the evaporator is started, so that the condensation of the evaporator can be prevented with a simple configuration without providing a heater for controlling the humidity and a moisture absorbing / releasing material.

In the above configuration, the refrigerant temperature detecting means for detecting the temperature of the refrigerant passing through the evaporator, and the compressor so that the refrigerant temperature does not fall below the set refrigerant temperature at which the evaporator defined in the computer room does not condense. It is preferable to include an operation control means for controlling the operation. According to the present invention, since the operation of the compressor is controlled so that the refrigerant temperature passing through the evaporator does not fall below the set refrigerant temperature that does not cause condensation in the evaporator specified in the computer room, Without providing a moisture release material, condensation of the evaporator can be prevented with a simple configuration.

Further, in the above configuration, the evaporator includes a plurality of evaporation units and is configured to selectively allow a refrigerant to flow through each evaporation unit, and an expansion valve is provided in each refrigerant pipe connected to each evaporation unit, The exhaust heat temperature detection means detects the exhaust heat temperature of the electronic equipment upstream of each evaporation unit, and the control means does not condense the evaporator defined in the computer room for each exhaust heat temperature. It is determined whether or not the exhaust heat temperature is lower than the set exhaust heat temperature, the refrigerant supply to the evaporation unit arranged downstream of the electronic device whose exhaust heat temperature is lower than the set exhaust heat temperature is stopped, and the exhaust heat temperature is less than the set exhaust heat temperature. If it exceeds, it is preferable to start supply of the refrigerant to the evaporation section.

  In the above configuration, the refrigerant temperature detection means detects an inlet refrigerant temperature and an outlet refrigerant temperature of the evaporator, and the operation control means determines that the minimum value of the inlet refrigerant temperature and the outlet refrigerant temperature is the set refrigerant temperature. It is preferable to control the operation of the compressor so as not to fall below.

  Further, in the above configuration, the evaporator includes a plurality of evaporation units and is configured to selectively allow a refrigerant to flow through each evaporation unit, and an expansion valve is provided in each refrigerant pipe connected to each evaporation unit, The refrigerant temperature detection means detects an inlet refrigerant temperature and an outlet refrigerant temperature of each evaporation section, and the operation control means determines that the minimum value of the inlet refrigerant temperature and the outlet refrigerant temperature of each evaporation section is the set refrigerant. It is preferable to control the operation of the compressor so as not to fall below the temperature.

  The present invention stops the supply of refrigerant to the evaporator when the exhaust heat temperature of the electronic device is equal to or lower than the set exhaust heat temperature at which the evaporator specified in the computer room does not condense, and the exhaust heat temperature is the set exhaust heat temperature. If it exceeds the upper limit, the refrigerant supply to the evaporator is started, so that the condensation of the evaporator can be prevented with a simple configuration.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an electronic device cooling system according to an embodiment of the present invention.
The electronic device cooling system 1 is a system that cools a plurality of electronic devices 3 (see FIG. 2) disposed in a computer room 2. The computer room 2 has a double floor, and the server rack 10 is placed on the double floor.

  FIG. 2 is a diagram showing the server rack 10. The server rack 10 includes a cabinet 11 whose front and rear surfaces are open, and partition plates (not shown) are disposed in the cabinet 11 with a space therebetween in the vertical direction. 11 A plurality of electronic devices 3 are stacked in the vertical direction in the cabinet 11 by being arranged toward the rear surface. In addition, a rear door 12 is provided on the rear surface of the cabinet 11 so as to open and close the rear opening so as to be closed. The rear door 12 is configured to be freely ventilated, and an electronic device cooling unit 20 is configured therein. Further, a caster 13 is provided at the bottom of the server rack 10 so that the server rack 10 can be easily moved.

  The electronic device 3 is a server or a network device. Generally, this type of electronic device is a fan-equipped electronic device provided with a cooling fan 4, and the fan 4 is driven when the temperature in the device exceeds a predetermined temperature. In addition, it has a forced air cooling function that introduces outside air into the equipment and discharges it from the back of the equipment. For this reason, by arranging the electronic device 3 with the rear surface thereof facing the rear surface of the cabinet, the indoor air is opened to the front of the cabinet by the fan 4 attached to the electronic device 3 as shown in FIG. The electronic device 3 is cooled, passes through the rear door 12, and returns to the room. Further, by opening the rear door 12, access to the electronic device 3 in the cabinet 11 is facilitated.

  The electronic device cooling unit 20 is configured integrally with the rear door 12 of the server rack 10, and the electronic device cooling units 20 provided in a plurality (three in this example) of the server racks 10 are combined into one heat source unit 30 (see FIG. 1) is connected in parallel to a main refrigerant pipe 31 (see FIG. 1) extending from the main refrigerant pipe 31 (see FIG. 1). That is, the plurality of (three) electronic device cooling units 20 and the heat source device 30 to which these units 20 are connected by piping constitute an electronic device cooling device 40. In the example shown in FIG. 1, 12 server racks 10 are arranged in the computer room 2, and the electronic device cooling unit 20 in the three server racks 10 is connected to one heat source unit 30. The case where the electronic device cooling device 40 is arrange | positioned 4 systems is shown.

  The electronic device cooling unit 20 is a unit that constitutes a refrigeration circuit that performs a refrigeration cycle by being connected to the heat source unit 30 by piping, and includes an evaporator 21 and is discharged from the electronic device 3 as shown in FIG. When air flows through the evaporator 21 in the rear door 12, the air is cooled by the evaporator 21 and returned to the room. The evaporator 21 extends over the rear door 12 and is divided into an upper evaporation section 22 and a lower evaporation section 23 at a substantially middle portion between the upper and lower sides, and cools the electronic device 3 in the upper half of the cabinet 11. The upper evaporation unit 22 is in charge, and the lower evaporation unit 23 is in charge of cooling the lower half of the electronic device 3.

  FIG. 3 is a diagram showing a circuit configuration of the electronic device cooling apparatus 40. As shown in this figure, the electronic device cooling unit 20 is connected to the main liquid pipe 31A and the main gas pipe 31B constituting the main refrigerant pipe 31 extending from the heat source unit 30 via the flexible liquid pipe 25 and the flexible gas pipe 26. Connected in parallel. As the flexible liquid pipe 25 and the flexible gas pipe 26, a flexible tube having flexibility and refrigerant impermeability is applied. As the flexible liquid pipe 25, a relatively small diameter tube is applied, and the flexible gas pipe 26 has a relatively large diameter. A tube is applied.

  The main liquid pipe 31A and the main gas pipe 31B extending from the heat source device 30 are provided with a plurality of (five in this example) connection ports P1A to P5A and P1B to P5B for connecting the flexible liquid pipe and the flexible gas pipe, respectively. In this configuration, one end of the flexible liquid pipe 25 and the flexible gas pipe 26 is connected to three sets of the connection ports P1A to P5A and P1B to P5B, thereby three electronic device cooling units 20 (evaporators 21). ) And the remaining two sets of connection ports P4A, P5A, P4B and P5B are used as connection ports for expansion used when the electronic device cooling unit 20 or the heat source unit 30 is expanded. That is, the remaining two sets of connection ports P4A, P5A, P4B, and P5B are used as connection ports for connecting the electronic device cooling unit 20 added when the server rack 10 is added or as connection ports for connecting the additional heat source unit 30. .

The other end of the flexible liquid pipe 25 is connected to the liquid pipe connection part PIN of the electronic device cooling unit 20. The refrigerant pipe 27 extending from the liquid pipe connection portion PIN is branched into two, one branch pipe 27A is connected to the inlet of the upper evaporation section 22 via the expansion valve 28A, and the other branch pipe 27B is connected to the expansion valve 28B. To the inlet of the lower evaporator 23.
The outlets of the evaporating units 22 and 23 are connected to one merging refrigerant pipe (gas pipe) 29, and the flexible gas pipe 26 is connected to the gas pipe connecting part POUT provided at the end of the merging refrigerant pipe 29. . Thus, the refrigerant pipe is connected to the evaporation units 22 and 23 in the electronic device cooling unit 20 so that the refrigerant can be selectively circulated.
Thus, since the evaporator 21 of the electronic device cooling unit 20 is connected via the flexible liquid pipe 25 and the flexible gas pipe 26, the flexible pipes 25, 26 are opened when the rear door 12 in which the evaporator 21 is built is opened and closed. Does not hinder the opening and closing of the rear door 12. Further, the position of the server rack 10 can be finely adjusted even when these pipes are connected.

  Here, as shown in FIG. 1, the main liquid pipe 31A and the main gas pipe 31B are routed in the underfloor space between the upper floor 2A and the lower floor 2B of the computer room 2, and the main liquid pipe 31A and the main gas pipe 31B. The flexible liquid pipe 25 and the flexible gas pipe 26 connected to the connection ports P1A to P5A and P1B to P5B of the gas pipe 31B are connected to the evaporator 21 in the rear door 12 through the opening hole 2C (see FIG. 2) of the upper floor 2A. For this reason, as shown in FIG. 2, the flexible liquid pipe 25 and the flexible gas pipe 26 extend downward from the evaporator 21 and then are routed so as to bend gently in the underfloor space. By providing a sufficient margin, only the flexible pipes 25 and 26 move in accordance with the movement of the rear door 12 when the rear door 12 is opened and closed. Accordingly, no force is applied to the other pipes when the rear door 12 is opened and closed, and the steel pipes can be applied to the other pipes, for example, the main liquid pipe 31A and the main gas pipe 31B.

  In the electronic device cooling unit 20, an electrical unit 51 and a remote controller 52 connected to the electrical unit 51 are provided below the evaporator 21. The electrical unit 51 includes four temperature sensors (refrigerant temperature detection means) for the inlet refrigerant temperature L1 and the outlet refrigerant temperature G1 of the upper evaporator 22, and the inlet refrigerant temperature L2 and the outlet refrigerant temperature G2 of the lower evaporator 23. Each of the expansion valves 28A and 28B is controlled so as to have an appropriate degree of superheat based on the temperature difference (L1-G1, L2-G2) of each of the evaporators 22 and 23. And a function of communicating with the heat source device 30.

  In addition, as shown in FIG. 2, the electronic device cooling unit 20 is disposed on the upstream side of the upper evaporation unit 22 and the lower evaporation unit 23, and is discharged from the electronic device 3 accommodated on the upper and lower sides. Exhaust heat temperature sensors (exhaust heat temperature detecting means) 29E and 29F that detect the temperature (exhaust heat temperature) TX1 and TX2 of the air to be output, and outputs of these sensors 29E and 29F are input to the electrical unit 51.

  The remote controller 52 is disposed on the side surface or the back surface of the server rack 10 in the computer room 2 and connected to the electrical unit 51 in the rear door 12 by wire or wirelessly. Although not shown, the remote controller 52 is provided with an indoor temperature sensor, an operation button, a display unit, a buzzer (sounding unit), and the like. Stop, change of set temperature T0, notification of various error messages (display and buzzer sound output), etc. are performed. Here, the set temperature T0 is the target temperature of the electronic device cooling unit 20, and normally the indoor target temperature of the computer room 2 is set. And in this electronic device cooling device 40, control of each part is performed so that the temperature of the air which entered from the front side opening of the cabinet 11, or the air which passed the evaporator 21 becomes this preset temperature T0.

The heat source device 30 is installed outside the room, and generally includes a compressor 32 that compresses the refrigerant, an oil separator 33, a four-way valve 34, a heat source side heat exchanger (condenser) 35, an expansion valve 36, and a receiver tank 37. The main liquid pipe 31 </ b> A is connected to the receiver tank 37 in order, and the main gas pipe 31 </ b> B is connected to the low-pressure side pipe 41 connected to the compressor 32 inlet via the accumulator 38.
The compressor 32 has an AC compressor (constant capacity type compressor) 32A for constant speed operation and an inverter compressor (variable capacity type compressor) 32B for variable frequency operation, which are in parallel. The cooling capacity of the entire heat source apparatus 30 is configured to be variable by connecting and controlling the on / off control of the compressors 32A and 32B and the operation frequency of the compressor 32B in accordance with the cooling load.

More specifically, check valves 42A and 42B are provided on the discharge sides of the compressors 32A and 32B, respectively, and the oil separator 33 is connected to the high-pressure side pipe 42 that merges downstream of the check valves 42A and 42B. The check valve 43, the four-way valve 34, the heat source side heat exchanger 35, the expansion valve 36, and the receiver tank 37 are sequentially connected. The low-pressure side pipe 41 connected to the suction side of each compressor 32A, 32B is connected downstream of the accumulator 38, connected to the four-way valve 34 upstream of the accumulator 38, and connected to the main gas pipe 31B via the four-way valve 34. Connected. The four-way valve 34 is not switched and is fixed to the state shown in FIG.
Further, a check valve 44 is connected to the high-pressure side pipe 42 in parallel with the expansion valve 36, and the check valve 44 allows a flow from the heat source side heat exchanger 35 to the receiver tank 37 and a reverse flow. Is prohibited. A refrigerant return pipe 45 is connected between the check valves 42A and 42B and the oil separator 33, and the tip of the refrigerant return pipe 45 is connected to the suction side of the compressors 32A and 32B. The refrigerant return pipe 45 is provided with an opening / closing valve 46, and by opening the opening / closing valve 46, a part of the refrigerant discharged from the compressors 32A, 32B can be returned to the suction side of the compressors 32A, 32B. The discharge capacity of the compressors 32A and 32B can be reduced.

  The high pressure side pipe 42 is connected to the main liquid pipe 31A via the liquid side service valve 47, and the low pressure side pipe 41 is connected to the main gas pipe 31B via the gas side service valve 48. The oil separated by the oil separator 33 is returned to the suction side of the compressors 32A and 32B through the oil return pipe 49. In addition, the high pressure side of one compressor 32A, 32B and the low pressure side of the other compressor 32B, 32A are connected to each other by oil return pipes 32C, 32D, and the oil amount in each compressor 32A, 32B is adjusted appropriately. Is done. Further, high pressure switches 5A and 5B are respectively provided on the discharge side of the compressors 32A and 32B. When the discharge pressure of the compressors 32A and 32B exceeds the upper limit of the allowable range by the high pressure switches 5 and 6, each compressor The operation of 32A and 32B is stopped.

  The heat source unit 30 includes an electrical unit 61, and the electrical unit 61 is communicably connected to the electrical unit 51 of the electronic device cooling unit 20 connected to the heat source unit 30 via an internal / external communication line 62. The The electrical unit 61 transmits and receives control signals and operation signals to and from the electrical unit 51 of each electronic device cooling unit 20, and inputs the operation of the remote controller 52 provided on the electronic device cooling unit 20 side. Thus, each part of the electronic device cooling apparatus 40 is controlled.

In the electronic device cooling apparatus 40, the compressors 32A and 32B are operated under the control of the electrical unit 51 of the heat source unit 30. In this case, the electrical unit 51 operates the compressors 32A and 32B based on the difference between the outdoor temperature T2 detected by a temperature sensor (not shown) and the indoor temperature T1 detected by the remote controller 52. The temperature of the expansion valve 36 is controlled so that the temperature difference between the entrance and exit of the heat source side heat exchanger 35 is detected by a temperature sensor (not shown). Control.
In this case, the high-temperature and high-pressure refrigerant discharged from the compressors 32 </ b> A and 32 </ b> B is condensed and liquefied by the heat source side heat exchanger 35, and then passes through the main liquid pipe 31 </ b> A extending from the heat source device 30 to It is supplied to the equipment cooling unit 20.

In each electronic device cooling unit 20, the liquid refrigerant flowing through the main liquid pipe 31A flows through the flexible liquid pipe 25 and flows through the refrigerant pipe 27, where it is divided into two systems, one of which passes through the expansion valve 28A and passes through the upper evaporation section. 22, and the other flows through the lower evaporation section 23 through the expansion valve 28 </ b> B, evaporates and gasifies in each evaporation section 22, 23, and each evaporation section 22 is generated by the refrigerant evaporation heat in each evaporation section 22, 23. , 23 is cooled.
Then, the refrigerant gasified in each of the evaporation units 22 and 23 merges in the merged refrigerant pipe 29, then flows through the flexible gas pipe 26 to the main gas pipe 31 </ b> B, and returns to the heat source unit 30. The refrigeration cycle is performed as described above.

  Here, the computer room 2 is generally managed at a constant humidity and a constant temperature, and a set exhaust heat temperature (for example, 25 ° C.) that does not condense is determined according to the humidity condition and the temperature condition. In this configuration, the set exhaust heat temperature is set in the remote controller 52 as the set temperature T0. In the computer room 2, the plurality of electronic devices 3 are basically operated in a 24-hour system, the unmanned time is long, and it is necessary to avoid the occurrence of condensation in the computer room 2 as much as possible.

Therefore, in the present embodiment, in order to avoid dew condensation in the electronic device cooling device 40, the first dew condensation prevention control for managing the exhaust heat temperature after passing through the evaporator 21 and the second refrigerant temperature for managing the refrigerant temperature passing through the evaporator 21. Condensation prevention control is performed.
FIG. 4 is a flowchart showing the first dew condensation prevention control. The electrical unit (control means) 51 of the electronic device cooling unit 20 acquires the room temperature T1 detected by the remote controller 52 (step S1), and determines whether or not the room temperature T1 is higher than the set temperature T0. (Step S2) When the room temperature T1 is equal to or lower than the set temperature T0 (Step S2: NO), since the computer room 2 is too cooled, the electrical unit 51 is forbidden (OFF) by the evaporator 21. An OFF flag corresponding to each of the expansion valves 28A and 28B is set in a predetermined area of the memory (not shown) (step S3).

  In the above determination, when the indoor temperature T1 exceeds the set temperature T0, the electrical unit 51 acquires the exhaust heat temperature TX1 of the upper evaporation section 22 (step S4), and this exhaust heat temperature TX1 is a threshold value (set by the remote controller 52). It is determined whether or not the temperature T0 + the server exhaust heat shift value α) is exceeded (step S5). Here, the server exhaust heat shift value α is a margin value for determining whether or not the exhaust heat temperature TX1 is sufficiently higher than the set temperature T0, and is a value within a range of zero to tens of degrees Celsius (for example, 5 ° C) is set. The server exhaust heat shift value α may be set to zero. In this case, it is determined whether or not the exhaust heat temperature TX1 exceeds the set temperature T0.

If an affirmative result is obtained in the determination of step S5 (step S5: YES), that is, if the exhaust heat temperature TX1 exceeds the threshold value (set temperature T0 + α), the electrical unit 51 allows cooling by the upper evaporation unit 22. In order to turn on (ON), an ON flag of the expansion valve 28A is set in a predetermined area of a memory (not shown) in the electrical unit 51 (step S6).
On the other hand, if a negative result is obtained in the determination in step S5 (step S5: NO), that is, if the exhaust heat temperature TX1 is equal to or lower than the threshold (set temperature T0 + α), the electrical unit 51 performs cooling by the upper evaporation unit 22. In order to prohibit (OFF), the OFF flag of the expansion valve 28A is set (step S7).

  Subsequently, the electrical unit 51 acquires the exhaust heat temperature TX2 of the lower evaporator 23 (step S8), and the exhaust heat temperature TX2 exceeds the threshold value (set temperature T0 of the remote controller 52 + server exhaust heat shift value α). It is determined whether or not there is (step S9). If an affirmative result is obtained in the determination of step S9 (step S9: YES), that is, if the exhaust heat temperature TX2 exceeds the threshold value (set temperature T0 + α), the ON flag of the expansion valve 28B is set (step) S10). On the other hand, when a positive result is obtained in the determination of step S9 (step S9: NO), that is, when the exhaust heat temperature TX2 is equal to or lower than the threshold value (set temperature T0 + α), the electrical unit 51 sets the OFF flag of the expansion valve 28B. Is set (step S11). The flag setting process described above is repeatedly executed during operation, and is rewritten according to the exhaust heat temperatures TX1 and TX2.

The flag information is appropriately referred to by a control unit (not shown) in the electrical unit 51. If the ON flag (permission flag) is set, the expansion valve 28A or 28B corresponding to the ON flag is opened as described above. Valve control is executed, and cooling is continued by the evaporation section 22 or 23 connected to the expansion valve 28A or 28B. On the other hand, if the OFF flag (prohibition flag) is set, the expansion valve 28A or 28B corresponding to the OFF flag is closed, and the cooling by the corresponding evaporation unit 22 or 23 is prohibited. For this reason, when both of the expansion valves 28A and 28B are OFF flags, the thermostat is turned off and the operation of the compressor 32 (32A and 32B) is stopped.
For this reason, when the exhaust heat temperatures TX1 and TX2 are equal to or lower than the set exhaust heat temperature T0 at which the evaporator 21 defined in the computer room 2 does not condense, the refrigerant supply to the evaporator 21 is stopped to avoid dew condensation. When the exhaust heat temperatures TX1 and TX2 surely exceed the set exhaust heat temperature T0, the refrigerant supply to the evaporator 21 is started, and cooling can be performed while preventing condensation.

FIG. 5 is a flowchart showing the second dew condensation prevention control.
The electrical unit (operation control means) 61 of the heat source device 30 acquires the inlet refrigerant temperature and the outlet refrigerant temperature of the evaporator 21 in order to acquire the refrigerant temperature passing through the evaporator 21 from each electronic device cooling unit 20 (step S1A). ). In this embodiment, as shown in FIG. 3, since the evaporator 21 is composed of an upper evaporator 22 and a lower evaporator 23, the inlet refrigerant temperatures L1, L2 and the outlet refrigerant temperatures of the evaporators 22, 23 are used. G1 and G2 are acquired.
Next, the electrical unit 61 obtains a value H1 (= min (L1, G1)) which is a minimum value of the inlet / outlet temperatures L1 and G1 of the upper evaporation unit 22 and specifies the minimum value of the refrigerant temperature, A value H2 (= min (L2, G2)) which is a minimum value of the inlet / outlet temperatures L1 and G1 of the evaporator 23 is obtained (step S2A).

Subsequently, the electrical unit 61 obtains a value HA (= min (H1, H2)) that is the minimum value of the values H1 and H2 (step S3A), and this value HA is defined in the computer room 2 as the evaporator 21. The compressors 32A and 32B are controlled so as not to fall below a set refrigerant temperature TH (for example, 18 ° C.) at which no condensation occurs (step S4A). Here, as the set refrigerant temperature TH, the lower limit value of the refrigerant temperature specified by the humidity condition and the temperature condition of the computer room 2 and at which the evaporator 21 does not condense is applied.
In this case, the compressors 32A and 32B are controlled when the value HA approaches the set refrigerant temperature TH and when both the compressors 32A and 32B are operating, the operating frequency of the variable capacity compressor 32B is operated. If the value HA is likely to fall below the set refrigerant temperature TH, the operation of the compressor 32B or the constant capacity type compressor 32A is stopped, and if it still falls below the set refrigerant temperature TH, both Feedback control and the like for stopping the operation of the compressors 32A and 32B are executed. That is, the operation control of the compressors 32A and 32B is performed so that the value HA does not fall below the set refrigerant temperature TH.
As a result, a situation in which the refrigerant temperature passing through the evaporator 21 falls below the set refrigerant temperature TH can be avoided, and condensation can be prevented.

  Further, in this configuration, temperature sensors 29G and 29H (see FIG. 2) are provided in the vicinity of the front surface of the cabinet 11 that sucks indoor air into the electronic device 3, and the intake air temperature is detected by the temperature sensors 29G and 29H. When the temperature becomes equal to or lower than the set temperature T0 of the remote controller 52, the thermostat is turned off, the operation of the compressor 32 (32A, 32B) is stopped, and when the temperature exceeds the set temperature T0 of the remote controller 52, the thermostat is turned on. Perform the process. According to this, it is possible to avoid overcooling the room by the electronic device cooling device 40, and this also makes it possible to prevent condensation of the evaporator 21.

As described above, according to this embodiment, the exhaust heat temperatures TX1 and TX2 of the electronic device 3 in the cabinet 11 are detected, and the evaporator 21 in which the exhaust heat temperatures TX1 and TX2 are defined in the computer room 2 is condensed. When the exhaust heat temperature becomes lower than the set exhaust heat temperature T0, the refrigerant supply to the evaporator 21 is stopped, and when the exhaust heat temperatures TX1 and TX2 surely exceed the set exhaust heat temperature T0, the refrigerant supply to the evaporator 21 is started. Therefore, cooling can be performed while preventing condensation in the evaporator 21.
In addition, in this configuration, since the above-described control is performed for each of the upper evaporation section 22 and the lower evaporation section 23 of the evaporator 21, the prevention of condensation in each of the evaporation sections 22 and 23 can be controlled independently, and condensation occurs. It is possible to stop the supply of the refrigerant only for the evaporating part 22 or 23 that has become, and to continue the cooling for the other evaporating part 23 or 22 to continue the cooling.

Further, in the present embodiment, the refrigerant temperature passing through the evaporator 21 is detected, and the refrigerant temperature of the compressors 32A and 32B is prevented so that the refrigerant temperature does not fall below the set refrigerant temperature TH at which the evaporator 21 defined in the computer room does not condense. Since the operation is controlled, it is possible to avoid a situation where the refrigerant temperature becomes too low and the evaporator 21 is condensed. In addition, in this configuration, the minimum refrigerant temperature is also detected for each of the upper evaporation unit 22 and the lower evaporation unit 23 of the evaporator 21, and the compressor 32 </ b> A is configured so as not to fall below the set refrigerant temperature TH based on the minimum refrigerant temperature. Since the operation of 32B is controlled, the dew condensation of both the evaporation units 22 and 23 can be reliably prevented.
Therefore, in this configuration, it is possible to prevent condensation with a simple configuration as compared with the conventional configuration in which a heater for controlling humidity and a moisture absorbing / releasing material are provided.

The best mode for carrying out the present invention has been described above, but the present invention is not limited to the above-described embodiment, and various modifications and changes can be made based on the technical idea of the present invention. For example, in the above-described embodiment, the case where the evaporator 21 is divided into the upper evaporation unit 22 and the lower evaporation unit 23 has been described. However, the present invention is not limited to this, and may be divided into three or more. It is possible to divide and perform the above-described condensation prevention control for each evaporation unit.
In the above-described embodiment, a relative humidity sensor and a dry bulb temperature sensor are further provided in the vicinity of the front surface of the cabinet 11 that sucks indoor air into the electronic device 3, and the dew point temperature of the sucked air is calculated from these detected temperatures, Operation control of the compressors 32A and 32B may be performed so that the air does not fall below the dew point temperature.

Further, in the above-described embodiment, the electronic apparatus 3 can be vertically placed by vertically arranging the partition plates that partition the inside of the cabinet 11 with a space left and right apart from each other. It may be configured. In this case, the evaporator is divided into a plurality of evaporators vertically and horizontally with these partition plates as a boundary, and an expansion valve is provided in each evaporator, and the heat radiation is cooled according to the heat radiation of each stage of electronic equipment. In addition, each expansion valve may be individually controlled, and a plurality of evaporation units are provided vertically or horizontally in one stage, and an expansion valve is provided in each evaporation part, and the same stage is different for each region. Each expansion valve may be individually controlled so as to cool the heat radiation.
In the above-described embodiment, the case where the air-cooled heat source device 30 is used has been described. However, the present invention is not limited to this, and a water-cooled heat source device 30X may be used as shown in FIG. When the water-cooled heat source unit 30X is used, since the heat source unit 30X is connected to the water pipes 101 and 102 extending from a cooling tower (not shown), a plurality of heat source units 30X can be arranged to overlap each other. 30X placement space is reduced. The present invention may also be applied to an electronic device cooling system in which an air conditioner is connected to the main refrigerant pipe 31 extending from the heat source units 30 and 30X, and the computer room 2 is air-conditioned by the air conditioner.
The heat source units 30 and 30X may be configured as a dedicated cooling (cooling) cycle machine that does not have a four-way valve. The compressor 32 included in the heat source devices 30 and 30X is of a type driven by an electric motor, that is, a so-called EHP (electric heat pump) type, but is not limited thereto, and is compressed by driving a gas engine. It is good also as a GHP (gas heat pump) type heat source machine which drives a machine.

It is a figure which shows the electronic device cooling system which concerns on one Embodiment of this invention. It is a figure which shows a server rack. It is a figure which shows the circuit structure of an electronic device cooling device. It is a flowchart which shows 1st dew condensation prevention control. It is a flowchart which shows 2nd dew condensation prevention control. It is a figure which shows the electronic device cooling system using a water-cooling type heat source machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic device cooling system 2 Computer room 3 Electronic device 4 Fan 10 Server rack 11 Cabinet 12 Rear door 20 Electronic device cooling unit 21 Evaporator 22 Upper evaporation part 23 Lower evaporation part 25 Flexible liquid pipe 26 Flexible gas pipe 28A, 28B, 36 Expansion valve 30, 30X Heat source machine 31 Main refrigerant pipe 31A Main liquid pipe 31B Main gas pipe 32 Compressor 32A Constant capacity compressor 32B Variable capacity compressor 40 Electronic equipment cooling device 51 Electrical unit (control means)
52 Remote controller 61 Electrical unit (operation control means)
P1A to P5A and P1B to P5B connection ports

Claims (5)

A heat source machine having a compressor and a condenser;
An evaporator connected to a refrigerant pipe extending from the heat source unit and disposed in a rear door that closes an opening of a cabinet that houses an electronic device with a fan;
The refrigeration cycle is configured by
Arranging the cabinet in a computer room,
The air blown by a fan attached to the electronic device is cooled by the evaporator of the rear door and returned to the computer room,
Means for detecting an indoor temperature of the computer room;
And a exhaust heat temperature detecting unit for detecting exhaust heat temperature of the electronic device,
When the indoor temperature of the computer room is equal to or lower than the set exhaust heat temperature at which the evaporator is not condensed as defined in the computer room, the expansion valve of the evaporator is closed, and the indoor temperature exceeds the set exhaust heat temperature , Comparing the exhaust heat temperature with a threshold value obtained by adding a server exhaust heat shift value to the set exhaust heat temperature, and when the exhaust heat temperature is higher than the threshold , open the expansion valve of the evaporator , An electronic device cooling apparatus comprising: control means for closing an expansion valve of the evaporator when an exhaust heat temperature is lower than the threshold value . The electronic device cooling device according to claim 1,
Refrigerant temperature detecting means for detecting the refrigerant temperature passing through the evaporator;
An electronic device cooling apparatus comprising: operation control means for controlling the operation of the compressor so that the refrigerant temperature does not fall below a set refrigerant temperature at which the evaporator defined in the computer room does not condense. . In the electronic device cooling device according to claim 1 or 2,
The evaporator is composed of a plurality of evaporation units, and is configured to selectively allow a refrigerant to flow through each evaporation unit, and an expansion valve is provided in each refrigerant pipe connected to each evaporation unit,
The exhaust heat temperature detection means detects the exhaust heat temperature of the electronic equipment upstream of each evaporation unit,
The control means determines, for each exhaust heat temperature, whether or not the evaporator specified in the computer room is below a set exhaust heat temperature at which condensation does not occur, and an exhaust heat temperature of an electronic device having a set exhaust heat temperature or less. An electronic device cooling apparatus characterized by stopping supply of refrigerant to an evaporator disposed downstream and starting supply of refrigerant to the evaporator when the exhaust heat temperature exceeds a set exhaust heat temperature. In the electronic device cooling device according to claim 2 ,
The refrigerant temperature detection means detects an inlet refrigerant temperature and an outlet refrigerant temperature of the evaporator,
The electronic device cooling apparatus according to claim 1, wherein the operation control means controls the operation of the compressor so that a minimum value of the inlet refrigerant temperature and the outlet refrigerant temperature does not fall below the set refrigerant temperature. In the electronic device cooling device according to claim 2 or 4 ,
The evaporator is composed of a plurality of evaporation units, and is configured to selectively allow a refrigerant to flow through each evaporation unit, and an expansion valve is provided in each refrigerant pipe connected to each evaporation unit,
The refrigerant temperature detection means detects an inlet refrigerant temperature and an outlet refrigerant temperature of each evaporation unit,
The operation control means controls the operation of the compressor so that the minimum value of the inlet refrigerant temperature and the outlet refrigerant temperature of each evaporation section does not fall below the set refrigerant temperature. apparatus.

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