JPH0774717B2 - Cooling system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device that cools a cooled fluid returning from a device to be cooled and then sends the cooled fluid to the device, and more specifically, a cooled fluid sent to the device. The present invention relates to a cooling device that alleviates transient changes in temperature.

[Prior Art] Production lines and research facilities for precision equipment require cooling water that is close to the room temperature and has a stable temperature. However, by cooling the fluid to be cooled returning from the equipment to be cooled, Conventionally, a closed cooling tower or a compression chiller has been used as a cooling device for sending out to equipment. With these cooling devices, for example, in a closed cooling tower, it is impossible to cool the temperature to about 30 ° C at most in summer, etc., and it is impossible to cool the fluid to be cooled to a medium or lower temperature than required by precision equipment. There was a problem. In addition, the compression chiller is cooled to about 7 to 17 ° C and is liable to cause dew condensation due to overcooling, which is not preferable for quality control, and it is difficult to maintain a constant temperature of the fluid to be cooled and there is a problem in maintaining dimensional accuracy. .

Therefore, as a cooling device capable of maintaining a constant temperature in the middle-low temperature range of about 18 to 29 ° C., an air-cooling type cooling tower having a heat transfer pipe and a fan for blowing air to the heat transfer pipe, a compressor and a condenser. A cooling device provided with a chiller having an expansion valve, an evaporator, and a refrigerant that circulates these, and a pipeline for guiding a fluid to be cooled returning from a device to be cooled to the cooling tower and an evaporator and then sending the fluid to the device. Also, a cooling device has been proposed in which the above cooling tower is an evaporation type cooling tower having a water sprinkling mechanism (Actual No. 61-84480).

[Problems to be Solved by the Invention] The cooling device described above is a cooling device that can maintain a constant temperature in the middle to low temperature range of about 18 to 29 ° C. and that prevents unnecessary overcooling. Although the amount of water sprayed is continuously controlled, the compressor is controlled to start / stop one unit or to control the number of units by multiple units, so the transient change at the time of starting / stopping the compressor is large. There is a problem that the temperature of the fluid delivered to the device becomes transiently too low immediately after the start-up, and the temperature of the fluid delivered to the device becomes transiently too high immediately after the compressor is stopped.

Therefore, it is an object of the present invention to provide a cooling device that alleviates the transient change in the temperature of the fluid to be cooled sent to the equipment at the time of starting and stopping the compressor.

[Means for Solving the Problems] The present invention has been made to solve the above problems, that is, claim 1 of the present invention has a heat transfer pipe and a fan for blowing air to the heat transfer pipe. A cooling tower, a chiller having a compressor, a condenser, an expansion valve, an evaporator, and a refrigerant that circulates them, and a cooled fluid returning from a device to be cooled is guided to the cooling tower and the evaporator in this order and then to the device. In a cooling device provided with a duct for sending out, a cooling device that temporarily reduces the air flow of the fan when starting the compressor and temporarily increases the air flow of the fan when stopping the compressor. is there. At that time, the cooling tower may be either an air cooling type or an evaporation type, and the condenser may be an air cooling type or a water cooling type.

According to a second aspect of the present invention, the cooling tower in the cooling device is an evaporative cooling tower having a water sprinkling mechanism for the electric heating pipe, and when the compressor is started, the amount of water sprinkling on the heat transfer pipe is temporarily reduced,
This is a cooling device that temporarily increases the amount of water sprayed to the heat transfer pipe when the compressor is stopped.

[Operation] When the compressor is started in order to increase the cooling capacity, the temperature of the fluid sent to the equipment temporarily drops, but the air flow rate of the fan or the dispersion to the heat transfer pipe is interlocked with the start of the compressor. Since the amount of water is temporarily reduced, the transient characteristic at the time of starting the compressor is improved. Similarly, if the compressor is stopped to reduce the cooling capacity, the temperature of the fluid sent to the equipment will temporarily rise, but the air flow of the fan or the amount of water sprayed to the heat transfer pipe will be linked to the stop of the compressor. Is temporarily increased, the transient characteristic when the compressor is stopped is improved.

[Embodiment] An embodiment of the present invention will be described with reference to the accompanying drawings. Second
The present invention is a system diagram of one embodiment of a cooling device. A cooling tower 1 has a plurality of layers of heat transfer pipes 2 and a fan 3, the fan 3 is driven by a motor 4, and an air intake port 5 is provided. The air sucked from the air is sent to the heat transfer pipe 2 to cool it. The chiller 10 includes a compressor 11, a condenser 12, an expansion valve 13 and an evaporator.
The refrigerant is circulated in the chiller 10, the refrigerant is compressed in the compressor 11, liquefied in the condenser 12 to radiate heat, and is evaporated in the evaporator 14 via the expansion valve 13 to absorb heat. Repeat the cycle. On the other hand, the fluid to be cooled returned from the device 20 to be cooled is guided to the booster pump 21, the heat transfer pipe 2 of the cooling tower 1 and the evaporator 14 in this order, and finally sent out to the device 20 via the circulation pump 22. Although the drawing shows only one system for the inflow and outflow piping to the cooling tower 1, the chiller 10, and the equipment 20, all or a part of these may be composed of a plurality of systems.

Regarding the operation of the cooling tower 1 and the chiller 10, when the temperature of the temperature detector 23 attached to the outlet of the evaporator 14 for the fluid to be cooled becomes higher than the set temperature range, first, the air flow rate of the fan 3 is increased. When the temperature of the temperature detector 23 becomes higher than the set temperature range, the number of operating compressors 11 is further increased, and when the temperature of the temperature detector 23 becomes lower than the set temperature range, On the contrary, first, the number of operating compressors 11 is reduced, and when the temperature of the temperature detector 23 is still lower than the set temperature range, the amount of air blown by the fan 3 is further reduced.

Then, when the compressor 11 is started, the temperature of the temperature detector 23 transiently drops significantly as shown by the dotted line in FIG. 1, and conversely, when the compressor 11 is stopped, the temperature of the temperature detector 23 becomes transient. It greatly rises and is inconvenient when cooling precision equipment.

Therefore, in the present embodiment, as shown in FIG. 1, when the compressor 11 is started, the air flow rate of the fan 3 is temporarily reduced in conjunction with this, and when the compressor 11 is stopped, it is interlocked with this. The fan 3 is controlled to temporarily increase the amount of air blown. As a result, as shown by the solid line in FIG. 1,
The temperature transient characteristic of the temperature detector 23 when the compressor 11 is started is improved, and similarly, the temperature transient characteristic of the temperature detector 23 when the compressor 11 is stopped is improved.

Note that the reduction in the air flow rate of the fan 3 that is interlocked when the compressor 11 is activated can be reduced by a certain amount for a certain period of time as shown by the solid line in FIG. 1, or can be made constant as shown by the dotted line in FIG. It is also possible to gradually return after reducing the amount by a certain amount of time. The same applies to the increase in the air flow rate of the fan 3 that is interlocked when the compressor 11 is stopped. The cooling tower 1 may be an evaporative cooling tower as long as it has a continuously controllable fan that blows air to the heat transfer pipe.

Next, as shown in FIG. 3, in addition to the heat transfer pipe 2 and the fan 3, the cooling tower 1 is provided with a water sprinkling header 6 installed above the heat transfer pipe 2 and a receiver installed below the heat transfer pipe 2. Aquarium 7
And a sprinkling mechanism having a sprinkling pump 8 for supplying the water in the water receiving tank 7 to the sprinkling header 6, the evaporative cooling tower is provided, and the transients at the time of starting and stopping the compressor 11 are the same as in the above embodiment. If the amount of water sprayed to the heat transfer pipe 2 is adjusted as a means for compensating for the change, the transient characteristics at the time of starting / stopping the compressor 11 are improved as in the above-described embodiment. As a means for compensating for a transient change at the time of starting / stopping the compressor, both the air flow rate of the fan and the water spray rate to the heat transfer pipe can be adjusted.

In the above embodiment, if the condenser 12 is cooled in the cooling tower 1, the entire apparatus is compactly formed. FIG. 3 shows such a structure.

Further, as shown in FIG. 4, the condenser 12 is constituted by a water-cooled condenser, and the fluid to be cooled returning from the equipment 20 to be cooled is guided to the water-cooled condenser, the cooling tower 1, and the evaporator 14 and then the equipment. May be sent to 20. In this case, by using the water-cooled condenser, the compression chiller unit can be made compact.

[Effects of the Invention] The cooling device according to claim 1 or 2 is a cooling device in which a closed cooling tower and a compression chiller are efficiently combined, in order to compensate for transient changes when starting and stopping the compressor. Since the fan air flow rate or the amount of water sprayed to the heat transfer pipe is adjusted, the transient characteristics of the temperature of the water to be cooled when starting and stopping the compressor are improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method for adjusting the fan air flow rate or the water sprinkling amount to the heat transfer pipe of the cooling device of the present invention, and a transient change in the temperature of the fluid to be cooled when the compressor is started and stopped.
4 to 4 are system diagrams of an embodiment of the cooling device of the present invention. 1 ... Cooling tower, 2 ... Heat transfer pipe, 3 ... Fan 4 ... Motor, 5 ... Air inlet 6 ... Sprinkler header, 7 ... Water receiving tank, 8 ... Sprinkler pump 10 ... Chiller, 11 …… Compressor, 12 …… Condenser 13 …… Expansion valve, 14 …… Evaporator, 20 …… Device 21 …… Booster pump, 22 …… Circulation pump 23 …… Temperature detector

Claims (2)

[Claims] 1. A cooling tower having a heat transfer pipe and a fan for blowing air to the heat transfer pipe, a chiller having a compressor, a condenser, an expansion valve, an evaporator, and a refrigerant circulating these, and a chiller to be cooled. In a cooling device provided with a pipe for guiding a cooled fluid returning from a device to the cooling tower and an evaporator in this order, and then supplying the pipe to the device, when the compressor is started, the amount of air blown by the fan is temporarily reduced. The cooling device is characterized by temporarily increasing the amount of air blown by the fan when the compressor is stopped. 2. A cooling tower having a heat transfer pipe and a water sprinkling mechanism for watering the heat transfer pipe, a chiller having a compressor, a condenser, an expansion valve, an evaporator, and a refrigerant circulating therein, and a cooling device. In the cooling device provided with the cooling tower returning the cooling target fluid from the device to the cooling tower, and a pipe for sending to the device in the order of the evaporator, when the compressor is started, the amount of water sprayed to the heat transfer pipe is changed. A cooling device characterized by temporarily reducing the amount of water sprayed to the heat transfer pipe when the compressor is stopped.