JPH08145597A - Cooling tower and operating method thereof - Google Patents

Abstract

PURPOSE: To provide a cooling tower and the operating method thereof, which are capable of preventing the generation of white smoke effectively while preventing the overcooling of a refrigerating machine. CONSTITUTION: A hot-water bypassing route 21, introducing the hot-water of a hot-water pipeline into a cold water pipeline 15 to increase the temperature of cold water when the temperature of the cold water of the cold water pipeline 15 is lowered than a predetermined temperature, and a cold water bypassing route 22, introducing the cold water of the cold water pipeline 15 into the hot-water pipeline to lower the temperature of hot-water when a relative humidity is elevated than a predetermined relative humidity, are provided between the inlet channel of cooling water for a cooling tower or the hot-water pipeline and the outlet channel of the cooling water for the same tower or the cold water pipeline 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling tower and a method of operating the same, and more specifically, it prevents white smoke from being generated from the cooling tower and prevents overcooling of a refrigerator or the like. The present invention relates to a cooling tower and its operating method.

[0002]

2. Description of the Related Art Conventionally, cooling towers used for computer rooms, district heating and cooling, etc. are often operated even in winter, and the white smoke that tends to be generated at that time is falsely recognized as contaminating the outside air. Or there is a risk of being mistaken for a fire,
In recent years, various measures have been taken so as not to generate white smoke from the cooling tower. For example, in a cross flow type cooling tower, the air discharged from the cooling tower is used by using a dry-wet mixing type filler having a dedicated air passage (dry part) in a part of the laminated filler in which a large number of gas-liquid contact plates are laminated. It is known that the generation of white smoke can be prevented by lowering the humidity of.

Further, in order to prevent the refrigerating machine or the like in which the cooling water cooled in the cooling tower circulates from overcooling, the blower of the cooling tower is stopped according to the temperature of the cooling water, or a part of the hot water in the cooling water inlet system. Is mixed with the cold water in the cooling water outlet system (see Japanese Patent Laid-Open No. 6-123591).

[0004]

Generally, in order to prevent the refrigerator from overcooling, the temperature of the cold water supplied to the refrigerator is kept at 22 ° C. or higher. Water (hot water) that exchanges heat with and is returned to the cooling tower
Temperature of 27 ° C or higher.

On the other hand, the ability to prevent white smoke in the cooling tower is largely affected by the inlet water temperature (warm water temperature). For example, a dry-wet mixing type filler having a wet part to dry part ratio of 3: 1 was used. In the case of a cooling tower, the relationship is as shown in FIG. FIG. 3 shows the white smoke generation limit in the relationship between the outside air temperature and relative humidity and the inlet water temperature. For example, when the outside air temperature is 0 ° C. and the inlet water temperature is 27 ° C., the relative humidity is about 55. If the outside air temperature is 0 ° C and the inlet water temperature is 22 ° C, it means that white smoke is not generated until the relative humidity rises to about 80%. There is.

Therefore, when the outside air temperature is 0 ° C. and the temperature of the hot water returning from the refrigerator to the cooling tower is about 27 ° C. as described above, generation of white smoke can be prevented up to a relative humidity of about 55%. However, the relative humidity is 55% under the weather conditions such as rain and snow.
If it exceeds the limit, white smoke will be generated.

Therefore, an object of the present invention is to provide a cooling tower and an operating method thereof which can effectively prevent white smoke from being generated while preventing the refrigerator from overcooling.

[0008]

In order to achieve the above-mentioned object, the cooling tower of the present invention has a cooling water temperature of the cooling water outlet system between the cooling water inlet system and the cooling water outlet system of the cooling tower. While providing a hot water bypass path for introducing hot water of the cooling water inlet system to the cooling water outlet system when the temperature falls below a predetermined temperature, when the relative humidity rises above a predetermined relative humidity,
A feature is that a chilled water bypass path for introducing chilled water from the chilled water outlet system to the chilled water inlet system is provided.

Further, the cooling tower operating method of the present invention detects the hot water temperature of the cooling water inlet system of the cooling tower, the cold water temperature of the cooling water outlet system of the cooling tower, the outside air temperature and the relative humidity, and detects the cooling tower outlet side. When a temperature of cold water in the cooling water falls below a predetermined temperature, a part of the hot water in the cooling water inlet system is introduced into the cooling water in the cooling water outlet system, and when the relative humidity rises and the white smoke generation limit of the cooling tower is exceeded, cooling is performed. The feature is that a part of the cold water of the water outlet system is introduced into the hot water of the cooling water inlet system.

[0010]

[Operation] According to the above configuration, the temperature of the cold water supplied to the refrigerator or the like can be maintained at a predetermined temperature or higher by introducing a part of the hot water into the cold water and mixing them. By introducing the parts into warm water and mixing them, it is possible to lower the inlet water temperature of the cooling tower and prevent the generation of white smoke.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail based on an embodiment shown in the drawings. FIG. 1 is a system diagram showing an embodiment of a cooling tower of the present invention, and FIG. 2 is a flow chart showing an embodiment of an operating method.

First, in FIG. 1, the cooling tower 1 causes the cooling water circulating in the refrigerator 2 to flow down from the cooling water inlet portion 11 at the upper part of the main body to the filler 12, and the cooling water and the air inlet on the side of the main body portion. Cooling water sucked from the portion 13 is brought into contact with the filling material 12 to cool it. Cooled cooling water (cold water)
Passes through the cooling water outlet (water receiving tank) 14 at the bottom of the main body through the cooling water piping 15 of the cooling water outlet system, the pump 15a, the valve 15
The cooling water (hot water) supplied to the refrigerator 2 via b and heated by heat exchange in the refrigerator 2 (hot water) passes through the hot water pipe 16 of the cooling water inlet system having the check valve 16a, and the cooling tower 1 Returned to. On the other hand, the cooling air whose temperature and humidity have risen by cooling the cooling water is sucked and discharged by the blower 18 provided in the exhaust port 17 at the top of the main body.

Between the cold water pipe 15 and the hot water pipe 16, a hot water bypass route 21 for introducing a part of the hot water in the hot water pipe 16 into the cold water pipe 15 and a part of the cold water in the cold water pipe 15 are provided. And a cold water bypass route 22 for introducing the hot water to the hot water pipe 16.
The valve 21a and the check valve 21b are installed in the cold water bypass route 2
The pump 2 has a pump 22a, a valve 22b, and a check valve 22c.

A chilled water thermometer 23 for detecting the temperature of chilled water to be supplied to the chiller 2 is provided at the inlet of the chiller 2 which is the end of the chilled water pipe 15. In the vicinity of the inlet portion 11, hot water thermometers 24 for detecting the temperature of hot water are provided, respectively, and further, a thermometer and a hygrometer for detecting the outside air temperature and relative humidity are provided (Fig. (Not shown). These thermometers and hygrometers are respectively connected to control means (not shown), and based on these detected values, the opening / closing of each valve and the operating state of the blower or pump are directly or indirectly via the control means. Controlled by.

The configuration of the pipes and the like can be appropriately selected according to the capacity of the cooling tower and the like.
In the above configuration, the mixing location of the cold water passing through the cold water bypass path 22 and the hot water returning to the cooling tower 1 may be on the downstream side of the branch portion of the hot water bypass path 21, and may be in the hot water pipe 16 as described above. However, the cold water may directly flow into the cooling water inlet portion 11 of the cooling tower 1. The cold water bypass path 22 may be directly connected to the cooling water outlet section 14 at the bottom of the main body as described above, but may be branched from the cold water pipe 15 upstream of the confluence of the hot water bypass path 21. Furthermore, the pump 2 of the cold water bypass route 22
2a may be fixed to the cooling tower main body.

Next, a method of operating the cooling tower having the above structure will be described with reference to the flow chart shown in FIG. First, with each thermometer and hygrometer, from the refrigerator 2 to the cooling tower 1
Temperature of hot water (inlet water temperature) Tw1 [℃], cooling tower 1
Temperature (outlet water temperature) Tw of cold water supplied from the refrigerator to the refrigerator 2
2 [° C.], the temperature of the air sucked from the air inlet portion 13 (inlet air dry bulb temperature) DB [° C.] and its relative humidity (inlet air relative humidity) RH [%] are measured (step 10).
1).

Then, the set maximum value of the outlet water temperature, for example, 3
2 ° C. and the outlet water temperature Tw2 are compared (step 102),
When the outlet water temperature Tw2 exceeds 32 ° C. in summer or the like, the valves 21a and 22b of the hot water bypass path 21 and the cold water bypass path 22 are closed (step 10).
3), all fans are operated (step 104). As a result, the entire amount of the cooling water flows through the cooling tower 1, and the cooling capacity of the cooling tower is brought to 100%. In this case, the outside air temperature is considerably high, for example, the outside air temperature is 30 ° C.
In this case, as is clear from FIG. 3, the relative humidity is 100%.
White smoke does not occur even if the inlet water temperature rises to 44 ° C in a state close to%.

When the outlet water temperature Tw2 is 32 ° C. or less, the limit value (white smoke generation limit temperature) T of the inlet water temperature Tw1 is calculated from the inlet air dry bulb temperature DB and the inlet air relative humidity RH.
Calculate w1max. This white smoke generation limit temperature Tw1m
Although ax varies depending on the configuration of the cooling tower 1, the ratio of the dry part of the dry-wet mixing type filler, and the like, for example, it is obtained by the following formula 1 and has the relationship shown in FIG. 3 (step 1
05). It should be noted that this calculation may be performed immediately after measuring each temperature and humidity, or may be performed immediately before the stage where this value is required.

[0019]

(Equation 1)

Next, the set minimum value of the outlet water temperature corresponding to the refrigerator 2, for example, 22 ° C. is compared with the outlet water temperature Tw2 (step 106), and when the outlet water temperature Tw2 is less than 22 ° C., the outlet water temperature Tw2. The valve 21a of the hot water bypass path 21 is opened until the temperature becomes 22 ° C. or higher (step 107). As a result, the temperature of the cold water supplied to the refrigerator 2 can be maintained at 22 ° C. or higher, and the refrigerator 2 can be prevented from overcooling.

In step 106, the outlet water temperature T
When w2 is 22 ° C. or higher, or after the outlet water temperature Tw2 is adjusted to 22 ° C. or higher in step 107, the inlet water temperature Tw
1 is compared with the white smoke generation limit temperature Tw1max (step 108), and the inlet water temperature Tw1 is the white smoke generation limit temperature T.
When it is lower than w1max, the cold water bypass route 22
The valve 22b is closed (step 109), and the operating state of the blower 18 is adjusted by the temperature of the outlet water temperature Tw2 (step 110).

On the other hand, in step 108, if the inlet water temperature Tw1 is equal to or higher than the white smoke generation limit temperature Tw1max,
The valve 22b of the cold water bypass path 22 is opened (step 111), and all the blowers are operated (step 10).
4).

As described above, when the temperature of the outlet water temperature Tw2 is equal to or lower than the set maximum value of 32 ° C., the cold water bypass is performed based on the result of comparing the inlet water temperature Tw1 with the white smoke generation limit temperature Tw1max in step 108. Valve 2 of path 22
By opening and closing 2b, efficient operation can be performed while preventing the generation of white smoke. This step 10
8 is the case where the outlet water temperature Tw2 is 22 ° C. or higher in step 106, or the outlet water temperature Tw2 is set to 22 in step 107.
Since it is a step that is performed after the temperature is adjusted to ℃ or higher, the temperature of the cold water supplied to the refrigerator 2 is naturally maintained at 22 ℃ or higher. As mentioned above, the temperature is 27 ° C. or higher. The inlet water temperature Tw1 is 27 ° C. and the outside air temperature is 0.
When the relative humidity is 55% or more, white smoke is generated when the relative humidity is about 55% or less from the formula 1 or FIG. However, as described above, the temperature of the hot water returning to the cooling tower 1 is set to, for example, 22 ° C. by opening the valve 22b of the cold water bypass path 22 and mixing a part of the cold water with the hot water of the hot water pipe 16. Can be lowered to 80% relative humidity
It will be possible to prevent the generation of white smoke until it rises to about%.

That is, when the temperature of the outlet water temperature Tw2 exceeds the set maximum value, such as in the summer, both bypass routes 21,
By closing the valves 21a and 22b of 22 and operating all the blowers, 100% of the cooling capacity of the cooling tower is exhibited.

Further, when the temperature of the outlet water temperature Tw2 is between the set maximum value and the set minimum value, the refrigerator 2 is not overcooled, so the valve 21a of the cold water bypass path 21 is kept closed to prevent rain. When the relative humidity rises above the white smoke prevention limit due to the start of rain, the cold water bypass route 2
By opening the second valve 22b and mixing a part of the cold water in the cold water pipe 15 with the hot water in the hot water pipe 16, the temperature of the hot water returning to the cooling tower 1 is lowered to prevent the generation of white smoke.

Further, when the temperature of the outlet water temperature Tw2 falls below the set minimum value in winter, etc., the hot water bypass route 21
The valve 21a is opened to mix a part of the hot water in the hot water pipe 16 with the cold water in the cold water pipe 15 to raise the temperature of the cold water supplied to the refrigerator 2 and prevent the refrigerator 2 from overcooling. At the same time, when the relative humidity rises above the white smoke prevention limit due to rain or snow, the cooling tower is opened by opening the valve 22b of the cold water bypass path 22 and mixing a part of the cold water with the hot water. Return to 1 Lower the temperature of hot water to prevent white smoke. In addition, the cold water is introduced by the valve 22.
Instead of opening / closing b, the pump 22a may be started / stopped.

The adjustment of the operating condition of the blower 18 in step 110 in the above-mentioned flowchart is carried out by adjusting the inlet water temperature Tw1 when white smoke does not occur even if the inlet water temperature Tw1 becomes considerably high due to the weather conditions of the day. It is possible to adopt a method such as stopping the blower until it reaches the limit at which white smoke does not occur.In addition, adjust the capacity of the blower, and if there are multiple blowers, increase or decrease the number of operating Or you can do it.

[0028]

As described above, according to the present invention,
Depending on the temperature of the cooling water, the temperature of the outside air, and the relative humidity, the hot water at the cooling tower inlet side is mixed with the cold water at the cooling tower outlet side, or the cold water at the cooling tower outlet side is mixed with the hot water at the cooling tower inlet side. Therefore, with a simple structure, it is possible to prevent overcooling of the refrigerator or the like while preventing the generation of white smoke, and improve the efficiency of the cooling tower, so that the cooling tower can be downsized.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a cooling tower of the present invention.

FIG. 2 is a flowchart showing an example of a driving method.

FIG. 3 is a diagram showing a relationship among an outside air temperature, a relative humidity, an inlet water temperature and a white smoke generation limit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cooling tower, 2 ... Refrigerator, 15 ... Cold water piping, 16 ... Hot water piping, 18 ... Blower, 21 ... Hot water bypass path, 22 ...
Cold water bypass route

Claims (2)

[Claims] 1. The hot water of the cooling water inlet system is supplied to the cooling water outlet system between the cooling water inlet system and the cooling water outlet system of the cooling tower when the temperature of the cooling water of the cooling water outlet system falls below a predetermined temperature. A cooling tower characterized in that a hot water bypass path for introducing is provided and a cold water bypass path for introducing cold water of a cooling water outlet system to a cooling water inlet system when the relative humidity rises above a predetermined relative humidity. 2. When the hot water temperature of the cooling water inlet system of the cooling tower, the cold water temperature of the cooling water outlet system of the cooling tower, the outside air temperature and the relative humidity are detected, and the cold water temperature at the cooling tower outlet side falls below a predetermined temperature. Part of the hot water from the cooling water inlet system is introduced into the cold water from the cooling water outlet system, and part of the cold water from the cooling water outlet system is cooled when the white smoke generation limit of the cooling tower is exceeded due to the increase in relative humidity. A method for operating a cooling tower, which is characterized in that the cooling tower is introduced into hot water of a water inlet system.