JP3256940B2 - Water level control method and water level control device for cooling tower water tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of cooling tower blocks each including a plurality of cooling towers and a common water tank, which are connected in parallel via a header and heat source equipment such as a refrigerator. The present invention relates to a method and an apparatus for controlling the water level (liquid level) of a water tank of a cooling tower block in a system connected to a circulation pipe, that is, a district cooling / heating system or the like.

[0002]

2. Description of the Related Art District heating / cooling is an effective energy supply means in urban areas, but is characterized by a large fluctuation in heat load between day / night and summer / winter. Therefore, it is necessary to consider the configuration of the district heating and cooling system so as to efficiently and smoothly cope with such a change in the heat load.

In general, a district cooling / heating system includes a so-called individual integrated system in which a plurality of individual combinations of a cooling tower 11 and a heat source device 41 are arranged as shown in FIG. 5 and a header 20 or the like as shown in FIG. A plurality of cooling towers 11 and heat source devices 4
1 and a so-called common header system (pump 25
May be provided on the side of the cooling tower 11 differently from the figure). In the individual integrated system, each combination is independent of each other, so that the number of water-passing units (that is, the number of operating units) can be easily changed according to fluctuations in heat load and the like. Is unnecessary. However, the circulation pipe 30 is required for the number of the cooling towers 11 and the like, and the piping is complicated in a large-scale system, and the construction cost is enormous. Would.

On the other hand, in the common header system, a plurality of cooling towers 11 are connected in parallel via a header 20 as shown in FIG. A set of circulation lines 30 is provided. Since the circulation line 30 is one set, the piping is simple as a whole,
Even when the cooling tower 11 and the heat source device 41 are far apart, the construction cost of the piping can be reduced. In addition, in a large-scale system of this type, since the number of cooling towers 11 is increased by a plurality of units in accordance with the development of the region, for example, as shown in FIG. The water tank 12 is commonly used, and a plurality of cooling tower blocks 10 are often configured.

However, in the case of the common header system as shown in the figure, there is a water tank 12 in which the water overflows because the water level varies among the water tanks 12 of each cooling tower block 10 and it is difficult to control the water level. Conversely, water tends to run out and there is a water tank 12 that causes air to be trapped in the pipe (in this case, the pump 25 and the heat source device 41 tend to be adversely affected mechanically). Aquarium 12
As shown in FIG. 6 (b), the water level differs for each water tank 12 (or a water tank through which more cooling towers are passed) than the water tank 12. Pressure loss (pressure loss) ΔP in pipeline 15 etc. to header 20
Is large, the balance of hydrostatic pressure with other water tanks 12
This is because the water level becomes higher by an amount corresponding to the pressure loss ΔP. In particular, when the cooling tower block 10 that does not pass water through one of the cooling towers 11 and the block 10 that passes all (for example, three) cooling towers 11 coexist, etc., each water tank 12
The water level difference between them also becomes considerably large. Therefore, the water level meter 50
(It is preferable that the water tanks 12 are provided on the header 20 in communication with the water tanks 12 as shown in the figure. This indicates a water level almost equal to that of the water tanks 12 in which the number of water supply units of the cooling tower 11 is zero.) Even if the replenishing water amount is controlled (for example, by the adjustment valve 52 in the figure) to achieve the appropriate level, appropriate water level control is not performed.

Means for achieving proper water level control in a common header system are shown in FIG. 7 or FIG. FIG. 7 shows a configuration in which a water level control device such as a water level gauge 56 and a water replenishing device 57 is provided for each of the water tanks 12 of the cooling tower block 10. It is attached to the conduit 15 between them. An example similar to FIG.
No. 79 gazette and magazine "Heating / Piping / Air Conditionin
g (Jan. 1988) ”pp.131-134“ Cooling tower system i
On the other hand, in the example of FIG. 8, the water tanks 12 are connected by a large-diameter communication pipe 17, and a water level difference between the water tanks 12 can be eliminated by such a communication pipe 17.

[0007]

The conventional means shown in FIGS. 7 and 8 have the effect of preventing overflow and entrapment of air in each water tank 12, but have the following disadvantages.

First, the means of FIG. 7 requires a large number of water level control devices, so that the equipment cost is high. The shut-off valve 16 also requires considerable cost due to its large size (diameter) and needs to be provided in a narrow space between the water tank 12 and the header 20. It is.

In the means shown in FIG. 8, unless a communication pipe 17 having a considerably large diameter is used, a pressure loss occurs and the difference in water level between the water tanks 12 cannot be sufficiently eliminated. The above problems also accompany. In addition, when the system is operated with the communication pipe 17 shut off for maintenance or the like, there is a disadvantage that the water level difference cannot be completely eliminated in some of the water tanks 12.

[0010] It is an object of the present invention to provide a control means capable of keeping the water levels of all the water tanks adequately without substantially increasing the equipment cost.

[0011]

According to a first aspect of the present invention, there is provided a cooling tower water tank having a plurality of cooling tower blocks each including a plurality of cooling towers and a common water tank. A water level control method for a water tank of a cooling tower block in a system (for example, a district cooling and heating system shown in FIG. 6) connected in parallel via a circulation pipe to a heat source device such as a refrigerator or the like, 1) In order to keep the difference in the number of cooling tower water units between each cooling tower block within the allowable limit, select the cooling tower through which water flows, and 2) set the water level (control (The above target value) is adjusted to adjust the amount of water in the system.

The set water level is preferably determined by a water level gauge attached to the header and connected to the water tank of each cooling tower block.

According to the third aspect of the present invention, the allowable limit of the above item a) regarding the difference in the number of cooling tower water passage units between the respective cooling tower blocks is set to 1 (one unit). It is particularly preferable to change the set water level in b) so that the water level in the water tank in the cooling tower block having a large number of water passage units is substantially constant (the target value thereof).

[0014] The water level control device of the present invention (claim 4) is a water level control device for a water tank of a cooling tower block in the same system as in claim 1, comprising: a) attached to each cooling tower; Water flow detection means (for example, a flow meter) that indicates whether or not water is flowing through each of them; b) The total number of water flow units in the cooling tower and the number of water flow units in each cooling tower block are determined by signals from the water flow detection means Based on them, the cooling means through which water is passed is selected and changed, and the calculating means for indicating the set water level to the following water level gauge (there is no need to be the calculating means of 1. The same function is shared and exerted. 2
C) a water level gauge attached to the header and communicating with the water tank of each cooling tower block, and d) replenishment to supply water into the system according to a signal from the water level gauge. And a water amount control means (for example, a control valve for makeup water).

[0015]

According to the water level control method of the cooling tower water tank of the present invention,
The water level in the water tank of each cooling tower block is controlled as follows, and overflow from the water tank and air entrainment are prevented.

In the method of the present invention, first, by selecting a cooling tower through which water flows, the difference in the number of cooling tower water flow units between the respective cooling tower blocks as described in 1) above is kept within an allowable limit. That is, the difference in the water level between the water tanks is reduced so that the number of water flow units of the cooling towers in each cooling tower block does not vary more than a certain value. If one cooling tower block does not pass water to one of the cooling towers but another cooling tower block passes water to many cooling towers, a large water level Although it is unavoidable that a difference occurs, if the method of the present invention reduces the variation in the number of water passage groups between the blocks, the water level difference between the water tanks falls within a certain range. When the water levels are equalized in this way, the so-called relative water levels between the water tanks are controlled, so that it is naturally easy to prevent overflow and the like in all the water tanks. The above-mentioned permissible limit for the difference in the number of water passage units is related to the pressure loss in the pipeline, the water level fluctuation amount of the water tank caused by the passage and stoppage of the cooling tower,
This value is specific to the system and is determined by the depth of the water tank.

In the method of the present invention, the absolute water level of each water tank is controlled by adjusting the amount of water in the system as described in 2) above. In other words, the total number of cooling towers in the cooling tower (that is, the number of cooling towers that are in a flowing state in the entire system)
Adjust the amount of water in the system to change the set water level in accordance with. If the set water level is changed in this way, even if the number of cooling towers in each cooling tower block increases or decreases as the total number of cooling towers increases or decreases, the absolute water level of each water tank based on that increases or decreases. Can be suppressed, and occurrence of inconvenience such as overflow can be avoided. Since water evaporates with the passage of water in each cooling tower, the amount of water in the system can usually be increased or decreased by adjusting the amount of makeup water.

It is preferable to set the above-mentioned set water level to the water level of a water level meter attached to the header and connected to the water tank of each cooling tower block as described in claim 2 in the following point. That is, first, such a water level gauge consists of simply attaching a single tube or cylinder-shaped container to the header so as to be a communicating tube for each water tank, and the water level is determined by the water level of the tube or container. It is easily measured as height.
Secondly, according to such a water level gauge, the water level of a water tank having no cooling tower water flow units (a water tank in a cooling tower block through which no cooling tower flows) is always accurately indicated. Therefore, setting the above-mentioned set water level based on such a water level gauge is naturally convenient for control.

Incidentally, the water level control method of the present invention is generally most preferably in accordance with the mode described in claim 3. First, setting the permissible limit in 1) above to 1 is nothing less than minimizing the difference in the number of cooling tower water flow units between each cooling tower block, and therefore the relative water level difference between the water tanks. Is the smallest. At the same time, the required depth of each water tank is minimized, so that when a new water tank or the like is manufactured, the effect of cost reduction is brought about. Also, during operation, regarding the absolute water level of each water tank, the water level of the water tank in the cooling tower block with a large number of cooling tower water supply units (since the above permissible limit is 1, the same number as the others or one more than the others) is the target. Value (constant value). That is, the set water level is appropriately lowered as the total number of water flow units in the cooling tower increases, and the fluctuation of the water level is suppressed in the water tank having a high water level. From these points, the upper limit of the water level is set in each water tank to prevent overflow, and the difference in water level between the water tanks is kept small, so that entrainment of air into the pipe is also prevented.

According to the water level control device for a cooling tower water tank of the present invention (claim 4), the above control method is realized as follows.

When the flow of water to one or more cooling towers is started, each of the water flow detecting means of the above a) detects whether or not water is passed through each cooling tower, and b ).

Based on a signal from each water flow detecting means,
The calculation means of b) grasps the total number of water passage units and the number of water passage units of the cooling tower for each cooling tower block.

The calculating means determines whether there is no large variation in the number of water passage units for each cooling tower block, that is, whether or not the difference in the number of water passage units between the cooling tower blocks is within an allowable limit. In addition, if it is not within the limit, the cooling tower through which water flows is selected and changed so as to keep within the limit.

At the same time, the calculating means determines the set water level of the water level meter in c) in correspondence with the total number of water flow units, and instructs the water level level to the water level meter.

The water level gauge of c) is attached to the header and communicates with each water tank, so that the water level gauge indicates the water level of the water tank with zero water flow, but emits a signal in accordance with the set water level specified by the arithmetic means.

The replenishing water amount control means d) controls the absolute water level of the water tank by adjusting the amount of water in the system according to the signal of the water level gauge, so that an overflow or the like does not occur.

[0027]

1 to 4 show an embodiment of the present invention.
FIG. 1 is a system diagram of water in a district heating and cooling system,
FIG. 2 shows each cooling tower block 10 in the system of FIG.
FIG. 2 is a schematic diagram for explaining an outline of a water tank 12 and the like and water level control thereof. 3 and 4 are a functional block diagram and a flowchart, respectively, relating to water level control in the system of FIG.

The system shown in FIG. 1 employs a so-called common header system, in which a large-diameter header 20 in which almost no pressure loss occurs and a set of circulation lines 30 (outgoing line 31 and return line 32). A plurality of cooling towers 11 and a refrigerator (or another heat source device such as a heat pump) 41 are connected via the cooling tower 11. The cooling towers 11 are arranged on a common water tank 12 for every three cooling towers 11 to constitute a cooling tower block 10, and four sets of these blocks 10 are connected in parallel to the header 20 as shown in the figure. The cooling water cooled in each cooling tower 11 accumulates in a common water tank 12 for each block 10,
After gathering from each water tank 12 to the header 20, the water is sent through the outgoing pipe 31 by a plurality of pumps 25 and enters one of the refrigerators 41, and reaches the cooling towers 11 again via the return pipe 32 and the on-off valve 14. . Outgoing pipe 31 and return pipe 32 of circulation line 30
Before and after, a collecting pipe similar to the header 20 is connected. Since water is evaporated in the cooling tower 11 during the passage of water, a makeup water supply pipe 53 having a control valve 52 is connected to the header 20, and on the header 20 for the purpose of grasping the required amount of makeup water, A vertical cylindrical water level gauge 50 is attached so as to communicate with the water tank 12.

In the system shown in FIG. 1, similarly to the example of FIG. 6 described above, if the number n (n _{1 to} n ₄ ) of water flowing through the cooling tower 11 in each of the cooling tower blocks 10 is different, the pipe 15 And the like, so that each water tank 12
(See FIG. 2). Therefore, in this system, the water level is controlled as described below in order to prevent overflow from the water tank 12 and air entrainment into the pipe 15 and beyond.

The content of the water level control is as follows. First, the number of cooling tower water flowing units in each of the four cooling tower blocks 10-that is, the cooling towers in the water flowing (operating) state in each block 10 (water tank 12). 11 numbers n _{1 to} n ₄ −
In addition, a cooling tower 11 through which water flows is selected so that a difference exceeding 1 (that is, 2 or more) does not occur. Block 1
0 When seems water passing cardinality n ₁ ~n ₄ your he says are significantly different, but also increases the difference in level between the water tank 12 by the difference in pressure loss is increased in the conduits 15 or the like, thus water passing cardinality n ₁ ~ N
If the difference is suppressed to 1 or less by leveling ₄ , the above-described pressure loss difference is reduced, and the water level between the water tanks 12 is also leveled.

As the so-called leveling, specifically, three patterns are provided according to the total number N of water passing units of the cooling tower 11, and the maximum value and the minimum value of each of the number of passing water units n _{1 to} n ₄ are determined for each pattern. It is determined as follows. That is, when 1 ≦ N ≦ 4, the minimum value of n _{1 to} n ₄ is 0, and the maximum value is 1 (pattern 1). When 5 ≦ N ≦ 8, the minimum value of n _{1 to} n ₄ is 1, and the maximum value is 1. 2 (pattern 2) When 9 ≦ N ≦ 12 The minimum value of n _{1 to} n ₄ is 2, and the maximum value is 3 (pattern 3). However, N = n ₁ + n ₂ + n ₃ + n ₄ . Regarding n _{1 to} n ₄ thus determined, the difference is naturally 1 or less (1 or 0) when any two are compared, so that the minimum water level is not generated between the four water tanks 12.

As a means for achieving such leveling, a control device shown in FIG. 3 is arranged in this system. In the figure, reference numeral 1 denotes arithmetic means which is a center of water level control for the water tank 12, and reference numeral 11a denotes a flow meter (flow switch) built in each cooling tower 11, that is, each cooling tower 11
Is a water flow detecting means for notifying whether or not water is flowing. When each flow meter 11a detects whether or not water flows through each cooling tower 11 and inputs a signal to the calculating means 1, the calculating means 1 calculates the total number N of water flowing through the cooling tower 11 and the cooling tower block 10 together. calculating the water flow cardinality n ₁ ~n ₄ of. Radix n ₁ ~
There is a difference of more than 1 between n ₄ (ie, the radix N
When the radixes n _{1 to} n ₄ do not follow the above-mentioned pattern), the arithmetic means 1 sets the cooling tower 11 through which the water flows so that the difference is 1 or less (that is, matches the above-mentioned pattern). The selected cooling tower 11 is instructed to change its operation (flow or stop). The operation means 1
The above control contents by the cooling tower 11 and the flow meter 11a are as follows.
In the flowchart of FIG. 4, the upper half (step S1
To S4). In the system of the embodiment, the flow of FIG. 4 is executed every 30 seconds.

As a second control for the water level, in this system, the amount of water supplied into the system is adjusted as follows. First, the makeup water supply pipe 53 and the control valve 5 shown in FIG.
The replenishment of water by 2 is performed so that the water level in the water level gauge 50 is maintained at the set water level specified by the calculating means 1 (FIG. 3). Since the water level of the water level gauge 50 is not passed through any of the cooling towers 11 (that is, n = 0), the water level of the water tank 12 in the block 10 in which the pressure loss in the pipe 15 is 0 always coincides with the water level of the water level gauge 50. A control signal is issued to a control valve 52 by a level controller 51 attached to 50. For the set water level of the water level gauge 50, the calculating means 1
Water level meter 50
And instruct the controller 51.

More specifically, the set water level of the water level gauge 50 is determined as follows in accordance with the above-mentioned pattern corresponding to the total number N of water flow units. That is, when 1 ≦ N ≦ 4, set water level P = P ₀ (pattern 1) When 5 ≦ N ≦ 8, set water level P = P ₀ − (α ₂ −α ₁ ) (pattern 2) 9 ≦ N ≦ At 12 Set water level P = P ₀ − (α ₃ −α ₁ ) (pattern 3). Here, P ₀ is the reference water level, α ₁ is the number of water passage groups n is 0
Represents the height (water level difference) at which the water level of the water tank 12 in the block 10 having the radix n = 1 is higher than that of the water tank 12 of the block 10. Similarly, α ₂ and α ₃ each represent a base n
= 2, n = 3 means the water level difference between the water tank 12 of the block 10 and the n = 0 block 10.

After setting the set water level in this way, the water level meter 5
If the water level of 0 is adjusted to this, the number of water-passing groups n is large
Side (n = 1 for pattern 1; for pattern 2
Block 1 on n = 2 side, n = 3 side for pattern 3)
The water level of the water tank 12 at 0 becomes a constant target value,
Bar flow can be easily prevented. That is, first putter
In case 1, the water tank 12 of the block 10 of n = 0 is a water level meter.
Since the water level matches the water level of 50, the water level is the set water level P = P
₀ Is maintained in the water tank 12 of the block 10 where n = 1.
The water level is P + α₁= P₀+ Α₁ become. Also putter
In case 2, the block 10 with n = 1 and the block with n = 2
10 and the water level in each tank 12 is P + α₁= P₀− (Α_Two−α₁) + Α₁= P₀+ 2α₁−α_Two P + α_Two= P₀− (Α_Two−α₁) + Α_Two= P₀+ Α₁ And the latter (the water level P of the water tank 12 where n = 2)₀+ Α₁) Is pa
It is equal to the water level of the water tank 12 for n = 1 in the case of turn 1. Pa
Also in the case of turn 3, the water tanks 12 of n = 2 and n = 3 are
Water level is P + α_Two= P₀− (Α_Three−α₁) + Α_Two= P₀+ Α₁+ Α_Two−α
_Three P + α_Three= P₀− (Α_Three−α₁) + Α_Three= P₀+ Α₁  And the latter (the water level P of the water tank 12 with n = 3)₀+ Α₁)
Of the block 10 with the larger n in the patterns 1 and 2.
It is also equal to the water level of the water tank 12. Thus, which puta
The water level is also high and the water level is high
Set the water level so that the water level in the
That the overflow is effectively prevented
Is natural.

FIG. 2 shows the case where the total number N of water flowing through the cooling tower 11 is 2 (only two open valves of the on-off valve 14 are shown in white) and the set water level is set as described above. FIG. 5 is a schematic diagram showing the water level of each water tank 12 and the water level gauge 50 when the control for adjusting the amount of replenishment water is performed by determining the water level. The water level of the water tank 12 in which the number n of water passing units is 0 is the set water level P in the water level meter 50.
(= P ₀ ), but the water level of the water tank 12 where n = 1 becomes P ₀ + α ₁ higher than that by α ₁ . According to the above control, the water level P ₀ + α ₁ is always constant irrespective of the total number N of water passing units. Therefore, in the specific design of the system, the reference water level P ₀ is set to a level higher than the 0 level of the water tank 12, and the water level rise α ₁ and the water level increase α ₁ when the number of flowing water units n = 1 are set in the water tank 12. The overflow pipe 12a may be provided so that the overflow port comes further upward by an appropriate height β as a margin.

In the functional block diagram of FIG. 3, the adjustment of the make-up water amount as described above as the second part for water level control is performed by the water level meter 50, the level controller 51, and the make-up water control valve centering on the operation means 1. 52. Further, in this embodiment, an alarm 50a is incorporated in the water level gauge 50, and it is monitored whether or not the actual water level is largely separated from the set water level upward or downward (alarm is performed when an abnormality occurs).

In this system of the embodiment, the adjustment of the makeup water amount by the makeup water supply line 53 (FIG. 1) and the control valve 52 (same) and the monitoring by the alarm 50a (FIG. 3) are continuously performed. The control of determining whether the set water level P is appropriate and changing it if necessary is performed every 30 seconds according to FIG. That is, after the number n of cooling tower water-passing units of each cooling tower block 10 is leveled (step S3), a pattern determined by the total number N of water passing towers of the cooling tower 11 is identified (step S5), and if the pattern is changed. If the time has not elapsed (step S6) and a sufficient time has elapsed since the previous change (step S9), the alarm 50a is activated (step S10). If the pattern is changed (step S6), Once the alarm 50a
Is canceled (step S7), and the set water level and alarm value (abnormal level) are changed (step S8).

By comprehensively performing the above control, in this system, the upper limit of the water level in each water tank 12 is determined to prevent overflow, and at the same time, each water tank 12
The water level difference between them is kept small, so that the entrainment of air into the pipe 15 and beyond is also prevented. In this sense, this system
It can be said that it is possible to smoothly cope with fluctuations in the heat load during the night and between summer and winter.

Although an embodiment has been described above, the present invention is not limited to this. For example, it goes without saying that the number of cooling towers in the cooling tower block or the number of cooling tower blocks 10 in the system is not limited to the example. There is no reason why the arrangement of the pump for water supply is limited to the example of FIG.

[0041]

According to the method for controlling the water level of the cooling tower water tank according to the present invention (claim 1), the water level difference between the water tanks falls within a certain range, and the absolute value of the water level of each water tank is controlled by the water flow of the cooling tower. Since the set water level is changed so that the influence of the increase / decrease of the radix is small, the overflow is prevented in each water tank and the entrainment of air into a pipe or the like is also avoided. Therefore, this method is extremely effective in a district cooling and heating system in which the number of water passages in the cooling tower changes with a change in heat load. As the control device, for example, a set of water level gauge and a control valve for the amount of make-up water may be used, and particularly expensive devices and large members are required as compared with the conventional system (such as FIG. 6). This is advantageous in terms of cost and layout.

According to the control method of the second aspect, the water level gauge is simply constructed, and the required water level is easily measured. Moreover, the water level gauge does not need to be provided for each water tank, and only needs to be attached to the header. Further, it is also advantageous in that the water level of the water tank having the number of cooling towers of zero which is suitable for setting the water level in the control method of claim 1 is always accurately indicated.

In particular, according to the method of the third aspect, the water level of the cooling tower water tank is most effectively controlled, and there is a great advantage that the manufacturing cost can be reduced by making the water tank shallow. In other words, the difference in the number of cooling tower water flow units between each cooling tower block is minimized, the relative water level difference between the water tanks is also minimized, and the fluctuation of the water level is suppressed for the water tank with a high water level. Item 1 can be implemented most ideally.

According to the water level control device of the present invention (claim 4), the control methods of claims 1 to 3 can be specifically implemented with the above advantages.

[Brief description of the drawings]

FIG. 1 is a system diagram of water in a district cooling / heating system shown as one embodiment of water level control according to the present invention.

FIG. 2 is a schematic diagram for explaining an outline of a water tank and the like of each cooling tower block and its water level control in the system of FIG. 1;

FIG. 3 is a functional block diagram relating to water level control of a water tank in the system of FIG. 1;

FIG. 4 is a flowchart relating to water level control of a water tank in the system of FIG. 1;

FIG. 5 is a system diagram showing a so-called individual integrated type conventional district heating and cooling system.

FIG. 6A is a system diagram showing an outline of a conventional district heating / cooling system of a so-called common header system.
(b) is an explanatory view showing that a water level difference occurs between water tanks in the system.

FIG. 7 is a schematic diagram showing water level control means conventionally employed in a common header system.

FIG. 8 is a schematic diagram showing another water level control means conventionally employed in a common header system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Calculation means 10 Cooling tower block 11 Cooling tower 11a Flow meter (flow detection means) 12 Water tank 20 Header 30 Circulation line 41 Refrigerator (heat source equipment) 50 Water level gauge 52 Control valve (supply water amount control means)

Claims (4)

(57) [Claims] 1. A plurality of cooling tower blocks each including a plurality of cooling towers and a common water tank, which are connected in parallel via a header and connected to a heat source device such as a refrigerator by a circulation pipe. A water level control method for a water tank of a cooling tower block in a cooling system, comprising selecting a cooling tower through which water flows so as to keep the difference in the number of cooling tower water units between the cooling tower blocks within an allowable limit,
A water level control method for a cooling tower water tank, comprising adjusting an amount of water in a system so as to change a set water level according to the total number of water flow units of the cooling tower. 2. The cooling tower water tank water level control method according to claim 1, wherein the set water level is determined by a water level meter attached to the header and connected to the water tank of each cooling tower block. 3. The above-mentioned permissible limit on the difference in the number of cooling tower water units between the respective cooling tower blocks is set to 1, and the water level of the water tank of the cooling tower block having a large number of cooling water blocks is set to a target value. 3. The method according to claim 1, wherein the set water level is changed.
The water level control method of the cooling tower water tank according to 4. 4. A plurality of cooling tower blocks each including a plurality of cooling towers and a common water tank, which are connected in parallel via a header and connected to a heat source device such as a refrigerator by a circulation line. A water level control device for a water tank of a cooling tower block in a cooling system, comprising: a) a water flow detecting means attached to each cooling tower to notify whether or not each of the cooling towers is flowing water; Based on the signal from the water detection means, the total number of water flow units in the cooling tower and the number of water flow units in each cooling tower block are grasped, and based on them, the cooling tower through which water flows is selected and changed. C) a water level gauge attached to the header, which communicates with the water tank of each cooling tower block and emits a signal according to the set water level, and d) water in the system according to the signal from the water level meter. Means for controlling the amount of water to be replenished Water level control device of the cooling tower water tank, characterized in that it comprises.