JP2651717B2 - Air cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention mainly relates to an air cooling device for conditioning air in a computer room or a dust-free room, and more particularly to an air cooling device with reduced power consumption.

2. Description of the Related Art In a computer room, a dust-free room, a sterile room, and the like, it is necessary to cool air that has risen to about 28 ° C. to about 18 ° C. regardless of the four seasons. FIG. 6 shows an example of a conventional air cooling device for harmony of the indoor air. The air cooling device cools the air in the indoor 6 by passing it through an evaporator 14 by a blower 4 to cool the indoor air. The refrigerant is circulated in the order of the compressor 11, the water-cooled condenser 12, the expansion valve 13, and the evaporator 14 to exchange heat with air in the evaporator 14, and the sealed cooling tower 20 and the water-cooled condenser A cooling device in which cooling water is circulated between the cooling tower 12 and the water-cooled condenser 12 to exchange heat with the refrigerant and radiate heat from the cooling tower 20.

[Problems to be Solved by the Invention] In the above-mentioned conventional air cooling device, when an air-cooling type cooling tower is used as the cooling tower 20, for example, cooling of the cooling water by the air-cooling type cooling tower because the outside air temperature is high in summer. Is limited to about 30 ° C., and the specifications of the cooling device are determined on the condition of the cooling water temperature. However, when the outside air temperature in winter falls, it is necessary to maintain the temperature of the cooling water at the outlet of the cooling tower 20 at about 20 ° C. or higher in order to prevent the refrigerant circulation amount from excessively decreasing. The cooling tower 20 is used in combination with a thermostat 43 attached to the cooling water pipe 41 at the
Has been used to control the outlet water temperature to a predetermined temperature.

Therefore, the compressor 11 operates all year round, and has a drawback that the power cost is enormous, and the situation is the same even if the cooling tower 20 is a closed evaporative cooling tower.

In the same manner as above, a compression refrigerator is installed indoors, and a cooling tower is installed outside the room.The compressor is always operated to avoid sudden changes in room temperature due to starting and stopping of the compressor of the compression refrigerator, and electric heating etc. There are those that re-heat the air to adjust the room temperature, those that send cold water obtained by an outdoor refrigerator to the room, and adjust the room temperature by controlling the amount of the cold water that passes through the room, and the like. However, since these compressors are operated throughout the year, power consumption is increased.

The present invention has been made in view of the above-described drawbacks, and has as its object to provide an air cooling device with reduced power consumption.

[Means for Solving the Problems] Since dehumidification is required in ordinary air conditioning equipment, the dew point temperature of the device should be 15 ° C or less to achieve comfortable indoor air conditions, for example, a temperature of 25 ° C and a relative humidity of about 55%. It is necessary to use a cold source temperature of 10 ° C to cool the air.
Degree is required.

On the other hand, in the air conditioning equipment in the computer room, the dehumidification load is extremely low because the number of occupants is small and the amount of outside air intake is small compared to the power consumption of the computer body and peripheral devices. In a dust-free room, a sterile room, or the like, a large air volume is required in order to maintain cleanliness. As a result, the range of the air temperature to be cooled and lowered is small. Therefore, in both cases, a device dew point temperature of 17 ° C. or more is sufficient, and for this purpose, a cooling source temperature for cooling air needs to be 15 ° C. or more.

Thus, the only way to obtain 10 ° C. cold water is with a refrigerator, but if it is sufficient to use about 15 ° C. cold water, the cooling tower can sufficiently obtain the cold water at least in winter.

The present invention has been made by paying attention to this fact, that is, the air to be cooled is passed through the air cooler and the evaporator in order, and the refrigerant is cooled in the order of the compressor, the water-cooled condenser, the expansion valve, and the evaporator. An air cooling device that circulates (hereinafter, this system is referred to as an intermediate cycle), and circulates cooling water in the order of a closed cooling tower, a compression chiller, the air cooler, and the water-cooled condenser. The closed cooling tower may be a closed air-cooled cooling tower or a closed evaporative cooling tower.

Here, an air reheater is disposed in series with the cooling water pipe at the outlet or inlet of the water-cooled condenser, or in parallel with the cooling water pipe of the water-cooled condenser, and the air to be cooled is further cooled after the evaporator. It can be passed through this air reheater.

In the above, at least one of the intermediate cycle compressor and the water-cooled condenser, an air cooler and an evaporator,
In addition, when an air reheater is installed, it can be installed at a distance from the air reheater, and the compressor, water-cooled condenser and compression chiller of the intermediate cycle must be incorporated inside the closed cooling tower. Alternatively, a plurality of air coolers and intermediate cycle evaporators may be arranged.

[Action] When the outside air temperature is low in winter, the temperature of the cooling water that can cool the air to the required device dew point temperature, that is, to cool the cooling water to approximately 15 ° C. or less, requires only the operation of the cooling tower. It is enough. Therefore, when the operation of the compression chiller and the compressor of the intermediate cycle is stopped and only the cooling tower is operated to send the cooling water to the air cooler, the heat of the air is transmitted to the cooling water in the air cooler, and the cooling water is cooled. Is radiated to the outside air in the cooling tower, and thus the air can be cooled to a predetermined temperature.

When the temperature of the outside air rises in the spring and autumn, and the cooling water of about 15 ° C. cannot be obtained by the operation of only the cooling tower, the operation of the compression chiller is stopped, and the cooling tower and other intermediate cycles are further stopped. When the compressor is operated, the heat of the air is transmitted to the cooling water in the air cooler, and further transmitted to the refrigerant in the evaporator of the intermediate cycle, and the heat of the refrigerant is transmitted to the cooling water in the water-cooled condenser of the intermediate cycle. The heat of the water is radiated to the outside air in the cooling tower, so that the air can be cooled to a predetermined temperature.

During the spring and fall seasons, the operation of the compressor in the intermediate cycle was stopped, and by operating the cooling tower and the compression chiller, the heat of the air was transmitted to the cooling water in the air cooler, and the heat of the cooling water was compressed by the cooling tower. In the chiller, heat can be radiated to the outside air.

In summer, operation of the cooling tower and the compressor of the intermediate cycle,
Or, when the air cannot be sufficiently cooled by the operation of the cooling tower and the compression chiller, when the cooling tower, the compression chiller and the intermediate cycle are all operated, the heat of the air is transferred to the cooling water in the air cooler. Further, the refrigerant is transmitted to the refrigerant in the evaporator of the intermediate cycle, the heat of the refrigerant is transmitted to the cooling water in the water-cooled condenser of the intermediate cycle, and the heat of the cooling water is radiated to the outside air in the cooling tower and the compression chiller, Thus, the air can be cooled to a predetermined temperature.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of an air cooling device showing one embodiment of the present invention. In an indoor unit 1, an air filter 2, an air cooler 3, and a blower 4 are provided. 10 compressors
11, a water-cooled condenser 12, an expansion valve 13, and an evaporator 14 are provided, and the air in the room 6 is supplied with an air filter 2, an air cooler 3,
It is configured to return to the room 6 through the duct 5 by the blower 4 after passing through the evaporator 14 of the intermediate cycle.

Intermediate cycle 10 compressor 11, water-cooled condenser 12, expansion valve
The refrigerant is circulated in the evaporator 14 and the evaporator 14 in that order, the refrigerant evaporates and absorbs heat in the evaporator 14 via the expansion valve 13, and is compressed in the compressor 11 to have a high temperature,
The cycle of liquefaction and heat release in the water-cooled condenser 12 is repeated.

Reference numeral 20 denotes a closed cooling tower. In this embodiment, the cooling tower 20 is constituted by a closed evaporative cooling tower.
The cooling water in the cooling coil 21 is cooled by blowing air to the cooling coil 21 and spraying the water in the water spray tank 23 from the watering header 25 to the cooling coil 21 by the watering pump 24.

Reference numeral 30 denotes a compression chiller, and the compression chiller 30 is a compressor.
31, a condenser 32, an expansion valve 33, an evaporator 34 and a refrigerant circulating through the refrigerant, the refrigerant evaporates in the evaporator 34 via the expansion valve 33 to cool the cooling water, and in the compressor 31 The cycle of compression to high temperature, liquefaction and heat release in the condenser 32 is repeated.

The cooling water at the evaporator 34 outlet of the compression chiller 30 is
The air is cooled by the cooling pipe 21 through the inlet pipe 41, reaches the indoor unit 1, passes through the air cooler 3 and the water-cooled condenser 12 of the intermediate cycle, passes through the outlet pipe 42, and reaches the outdoor. And returns to the evaporator 34 of the compression chiller.

Next, the operation of this embodiment will be described. In the winter season, when the outside air temperature is about 10 ° C., the cooling water of about 15 ° C. can be taken out only by the capacity of the cooling tower 20 alone. Is stopped, and only the cooling tower 20 is operated. At this time, the air at about 28 ° C. in the room 6 is cooled to about 18 ° C. by passing through the air cooler 3 and returns to the room 6. On the other hand, the cooling water of about 15 ° C. in the inlet pipe 41 is heated to about 26 ° C. by passing through the air cooler 3, enters the outlet pipe 42, and cooled to about 15 ° C. by passing through the cooling tower 20. Return to the inlet pipe 41.

The adjustment relating to the fluctuation of the cooling load or the outside air temperature is performed as follows. That is, for the adjustment of the cooling capacity of each chamber, the opening of the air cooler bypass valve 8 composed of the electric mixing three-way valve is adjusted based on the temperature detected by the thermostat 7 provided for each chamber. As for the adjustment of the cooling capacity of the entire apparatus in accordance with the fluctuation of the outside air temperature, the cooling tower fan 22 and / or the water spray flow rate are adjusted based on the temperature detected by the thermostat 43 provided in the inlet pipe 41. However, the cooling capacity of the entire apparatus may be adjusted by adjusting the opening degree of the outdoor unit bypass valve 44 that connects the inlet pipe 41 and the outlet pipe 42, or may be adjusted only by this.

As described above, in the winter season, the required cooling effect can be obtained while the intermediate cycle 10 and the compression chiller 30 consuming a large amount of power are stopped.

Next, during the spring and autumn seasons, even if the air cooler bypass valve 8 is fully closed and the cooling tower 20 is operated at full output,
When the sufficient cooling effect cannot be obtained in the room 6, the intermediate cycle 10 in the room 6 is operated,
Degree of air is passed through the air cooler 3
After cooling to about 18 ° C., it is further cooled to about 18 ° C. by passing through the evaporator 14 of the intermediate cycle and returns to the room 6.
In the intermediate cycle 10, the heat absorbed by the evaporator 14 is radiated by the water-cooled condenser 12. On the other hand, the cooling water of about 21 ° C. of the inlet pipe 41 is
It is heated to about 25 ° C. by passing through the air cooler 3 and further heated to about 29 ° C. by passing through the water-cooled condenser 12 of the intermediate cycle, and reaches the outlet pipe 42,
Inlet pipe cooled to about 21 ° C by passing through 20
Return to 41.

In this case, as for the adjustment relating to the fluctuation of the cooling load or the outside air temperature, the adjustment of the cooling capacity of the intermediate cycle 10 can be performed in addition to the adjustment in the winter. Further, since the air is cooled by the two stages of the air cooler 3 and the evaporator 14 of the intermediate cycle, the influence of the start / stop of the intermediate cycle 10 is small, that is, the excessive air temperature accompanying the start / stop. The change is small compared to a conventional cooling device. Further, with regard to the mitigation of the transient change, the air cooler bypass valve 8 is adjusted in synchronism with the start of the intermediate cycle 10 to slightly reduce the flow rate of the cooling water to the air cooler 3. This can be easily performed by adjusting the air cooler bypass valve 8 in synchronism with this to slightly increase the flow rate of the cooling water to the air cooler 3.

When the number of the indoor units 1 is one, or when there is no significant difference in the cooling load of each room 6, the operation of the intermediate cycle 10 is stopped as the operation method in the spring and autumn, and the cooling tower 20 and the compression chiller 30 are stopped. You can also drive. In this case, since the cooling water is cooled by the two stages of the cooling tower 10 and the compression chiller 30, the transient change of the cooling water temperature due to the start / stop of the compression chiller 30 is small. Regarding the mitigation of the transient change, when the compression chiller 30 is started, the amount of air blown or sprayed from the cooling tower 20 is slightly reduced in synchronization therewith, and when the compression chiller 30 is stopped, the cooling tower 20 is synchronized therewith. This can be easily performed by slightly increasing the amount of air blown or the amount of water sprayed. In addition, the transient change caused by the start / stop of the compression chiller 30 may be alleviated by adjusting the opening degree of the outdoor unit bypass valve 44 in synchronization with this or by using only this.

Next, when a sufficient cooling effect cannot be obtained by the operation of the cooling tower 20 and the intermediate cycle 10 or the operation of the cooling tower 20 and the compression chiller 30 in summer, the cooling tower 20 and the intermediate cycle 10 When you run everything with the chiller 30,
The air at about 28 ° C. in the room 6 is cooled down to about 23 ° C. by passing through the air cooler 3, and the evaporator of the intermediate cycle is
By passing through, it is further cooled to about 18 ° C. and returns to the room 6. In the intermediate cycle 10, the heat absorbed by the evaporator 14 is radiated by the water-cooled condenser 12. On the other hand, the cooling water of about 21 ° C. of the inlet pipe 41 passes through the air cooler 3 to be cooled to 26 ° C.
After passing through the water-cooled condenser 12 of the intermediate cycle, it is further heated to about 32 ° C. and reaches the outlet pipe 42. Next, in the cooling tower 20, outside air having a wet bulb temperature of about 26 ° C. is blown by the fan 22, and spray water having a spray temperature of about 28 ° C. is sprayed from the spray header 25.The cooling water passes through the cooling coil 21 of the cooling tower 20. Is cooled to about 28 ° C., and further cooled to about 21 ° C. by passing through the compression chiller 20, and returns to the inlet pipe 41.

The adjustment relating to the fluctuation of the cooling load or the outside air temperature can be performed in the same manner as in winter or spring and autumn, and the cooling capacity of the compression chiller can also be adjusted. The transient change accompanying the start / stop of the compression chiller can be mitigated by adjusting the amount of air blown or sprinkled by the cooling tower in synchronization with this, or by adjusting the opening of the outdoor unit bypass valve. The transient change caused by the start / stop of the air cooler can be mitigated by adjusting the opening of the air cooler bypass valve in synchronization with the start / stop.

As described above, it is only in summer that the intermediate cycle 10 having a large power consumption and the compression chiller 30 are operated together,
There is no need to operate either the intermediate cycle or the compression chiller during spring and autumn, and there is no need to operate both the intermediate cycle and the compression chiller during winter. Further, since the cooling water is heated by the air cooler 3 and the intermediate cycle water-cooled condenser 12, the thermal efficiency of the cooling tower 20 is increased, and as a result, the necessity of operating the compression chiller is reduced. As a result, the power consumption of the cooling device throughout the year can be reduced by about 50% compared to the conventional method.

In addition, since both air cooling and cooling water cooling are performed in two stages, the start-up of the intermediate cycle 10 or the compression chiller 30
The degree of influence due to the stop is small, and the transient change due to the start / stop can be easily mitigated. Further, if the air cooler 3 and the intermediate cycle 10 are provided for each of the plurality of chambers 6, it is possible to easily cope with the difference in heat load between the respective chambers 6, and as described above, the cooling tower 10 Since the heat efficiency of the cooling water pipes 41 and 42 is high, the diameters of the cooling water pipes 41 and 42 can be reduced, so that the power of the circulating pump 40 can be saved and the cost of piping work can be reduced.

Next, FIGS. 2 to 4 are main part system diagrams of another embodiment of the air cooling device of the present invention, after dehumidification by the air cooler 3 or the intermediate cycle evaporator 14 or both. ,
Regarding a reheat device for reheating air to a predetermined temperature, an air reheater is provided after the air flow of the evaporator 14 in the intermediate cycle.
50 is provided. 2 shows the cooling water at the outlet of the water-cooled condenser 12 of the intermediate cycle through the air reheater 50 to the outlet pipe 42, and the air reheater bypass valve 51 that bypasses the air reheater 50. The highest temperature that can be used as cooling water of the present apparatus is used as a heat source, and the amount of the heat source is adjustable.

Fig. 3 shows the cooling water at the outlet of the air cooler 3
The heat source is guided to the water-cooled condenser 12 through the air inlet 50, and an air reheater bypass valve 51 is provided. During the operation of the intermediate cycle 10 in the summer / spring / autumn season, the heat source in the configuration of FIG. In the case where is not required, the configuration shown in FIG. 3 can be adopted.

FIG. 4 shows the case where the cooling water at the outlet of the air cooler 3 is branched, guided to the air reheater 50, and joined to the outlet pipe 42 via the regulating valve 52, and when the intermediate cycle 10 is not operated in winter. When dehumidification is necessary only for such a case, the pressure loss caused by passing through the water-cooled condenser 12 can be avoided by such a configuration. In the configuration of FIG. 4, since the water-cooled condenser 12 and the air reheater 50 are arranged in parallel, when the former pressure loss is sufficiently larger than the latter, the regulating valve 52 Alternatively, a flow control valve may be arranged in series with the air reheater 50.

When the air reheater 50 is arranged as described above, the adjustment of the cooling capacity of each room and the mitigation of the transient change caused by the start / stop of the intermediate cycle 10 are performed by adjusting the opening of the air cooler bypass valve 8. Alternatively, or together with this, the opening degree of the air reheater bypass valve 51 or the regulating valve 52 may be adjusted.

As for the heat source of the air reheater 50, in addition to the above, the cooling water of the inlet pipe 41 can be guided to the air reheater 50 via the regulating valve and merged with the outlet pipe 42. In addition, when the compressor 11 of the intermediate cycle is operating in the spring or autumn or summer, the refrigerant at the outlet of the compressor 11 is guided to the air reheater 50 through the regulating valve as in the related art, and the water at the outlet of the water-cooled condenser 12 is provided. The heat can be combined with the refrigerant, and electric heat can also be used as a heat source of the air reheater 50.

With respect to the arrangement of the present cooling device, the operation noise of the indoor unit 1 can be reduced by arranging the compressor 11 of the intermediate cycle outdoors, and the indoor unit can be reduced by arranging the water-cooled condenser 12 outdoors. 1 becomes compact. If the compression chiller 30 is incorporated in the cooling tower 20, the installation area of the outdoor unit can be reduced. As an example of these, FIG.
Compression chiller 30 in cooling tower 20 and intermediate cycle compressor
1 shows a structure incorporating a water-cooled condenser 11 and 11.

Further, any or all of the above-described systems may be provided in plural. For example, for the indoor unit 1, the air cooler 3 and the evaporator
In addition, the air reheater 50 can be disposed if necessary, and as for the outdoor unit, one or both of the cooling tower 20 and the compression chiller 30 can be disposed.

[Effect of the Invention] As described above, the present invention cools not only the water-cooled condenser of the intermediate cycle but also the air cooler by the cooling tower, and the cooling tower is provided with a compression chiller. The operation time of the cycle and the compression chiller can be greatly reduced, and the power consumption of the cooling device per year can be significantly reduced.

[Brief description of the drawings]

FIGS. 1 and 5 are system diagrams showing one embodiment of the present invention, and FIG.
FIG. 4 to FIG. 4 are system diagrams showing main parts of another embodiment of the present invention, and FIG. 6 is a system diagram of a conventional cooling system. 1 ... indoor unit, 2 ... air filter, 3 ... air cooler 4 ... blower, 5 ... duct, 6 ... indoor 7 ... thermostat, 8 ... air cooler bypass valve 10 ... intermediate Cycle, 11 Compressor 12 Water-cooled condenser 13 Expansion valve 14 Evaporator 20 Closed cooling tower 21 Cooling coil 22 Fan 23 Sprinkler tank 24 ... watering pump, 25 ... watering header 30 ... compression chiller, 31 ... compressor, 32 ... condenser 33 ... expansion valve, 34 ... evaporator, 40 ... circulation pump 41 ... inlet Pipe, 42… Outlet pipe, 43… Thermostat 44… Outdoor unit bypass valve, 50… Air reheater 51… Air reheater bypass valve, 52… Adjustment valve

Claims (7)

(57) [Claims] 1. An air cooling device for circulating a refrigerant in the order of a compressor, a water-cooled condenser, an expansion valve and an evaporator to exchange heat with air in the evaporator to cool the air. An air cooler is attached to the upstream side of the passing air flow, and cooling water is circulated in the order of a closed cooling tower, a compression chiller, the air cooler, and the water-cooled condenser, and the air is cooled by the air cooler. An air cooling device, wherein heat is exchanged, heat exchange is performed with the refrigerant in the water-cooled condenser, and heat is radiated in the closed cooling tower and the compression chiller. 2. An air reheater is provided on a downstream side of an air flow passing through the air cooler and the evaporator, and the cooling water at the outlet of the water-cooled condenser is supplied to the air reheater via the air reheater. The air cooling device according to claim 1, wherein the air cooling device is led to a closed cooling tower. 3. An air reheater is provided on a downstream side of an air flow passing through the air cooler and the evaporator, and the cooling water at the outlet of the air cooler is cooled by the water cooling through the air reheater. 2. The air cooling device according to claim 1, wherein the air cooling device is led to a condenser. 4. An air reheater is provided on the downstream side of an air flow passing through the air cooler and the evaporator, and the cooling water branched from the air cooler outlet passes through the air reheater. The air cooling device according to claim 1, wherein the cooling water is joined to the cooling water at the outlet of the water-cooled condenser after the cooling. 5. The air cooling device according to claim 1, wherein at least one of the compressor and the water-cooled condenser is disposed apart from the air cooler and the evaporator. 6. The air cooling device according to claim 1, wherein the compressor, the water-cooled condenser and the compression chiller are incorporated in the closed cooling tower. 7. The air cooling device according to claim 1, wherein a plurality of the air coolers and the evaporators are arranged.