JP7108503B2 - Control device, heat source system, method and program for determining number of fans to start - Google Patents

Description

The present invention relates to a cooling tower control device, a heat source system, a method for determining the number of fans to be activated, and a program.

Some cooling towers that supply cooling water to refrigerators are provided with a plurality of fans. The cooling water exchanges heat with outside air blown by the fan of the cooling tower, is cooled to a desired temperature, and is supplied to the refrigerator. It is desirable that the number of fans to be activated when the cooling tower starts operating is appropriately determined in consideration of the temperature of the cooling water at that time, the outside air conditions, and the like. For example, when the number of activated fans is small, the cooling water temperature rises due to insufficient cooling capacity. Conversely, when the number of fans to be activated is large, power is required to drive the extra fans. In addition, for example, in winter in cold regions, there is a possibility that the refrigerator cannot be started due to an excessive drop in the cooling water temperature.

Patent Documents 1 and 2 disclose a method of determining the number of fans or the like to be activated according to the load. For example, in Patent Document 1, when the load is low, the bypass valve of the bypass pipe that connects the outward and return passages of the cooling water flow path in the pipe between the cooling tower and the refrigerator is fully opened, the fan is stopped, and the load is reduced. A control is disclosed in which the bypass valve is closed and the number of fans to be activated is increased as the air pressure rises.

Further, Patent Literature 2 discloses a method for appropriately controlling the number of activated cooling towers in a heat source system having a plurality of cooling towers commonly connected to a plurality of refrigerators.

Japanese Patent No. 3313934 Japanese Patent No. 5404132

The control methods described in Patent Literatures 1 and 2 control the number of fans and the like according to the load during operation of the cooling tower. However, these controls cannot be applied because the magnitude of the load is unknown when the cooling tower is started. Further, the control method described in Patent Document 2 is a control for an integrated cooling tower facility in which a plurality of cooling towers are assigned to a plurality of refrigerators as a whole, and one cooling tower is assigned to one refrigerator. It cannot be used for the paired cooling tower installations assigned to it. To date, no method has been provided for determining the appropriate number of fans to start at the start-up of a cooling tower.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a control device, a heat source system, a method for determining the number of fans to be activated, and a program that can solve the above-described problems.

According to one aspect of the present invention, there is provided a control device for a cooling tower to which a plurality of fans are connected, wherein the control device controls the values taken by parameters of the operating environment of the cooling tower that affect cooling water temperature control. Based on the range, the number of fans, and the value of the parameter at the start of operation of the cooling tower, the number of fans to be initially activated at the start of operation of the cooling tower is determined.

According to one aspect of the present invention, the control device sets a value obtained by dividing the range of values taken by the parameter by the number of the fans as an operating point threshold, and when the number of initially activated numbers is P, the number of the cooling tower Regarding the value Q of the parameter at the start of operation, the initial startup is performed when the lower limit value of the range + operating point threshold value × (P-1) ≤ Q < the lower limit value of the range + operating point threshold value × (P). Let P be the number of units.

According to one aspect of the present invention, the parameter is the temperature of the cooling water at the inlet of the refrigerator to which the cooling water is supplied, and the upper limit of the value taken by the parameter is a predetermined rated cooling water inlet The temperature is set, and the lower limit value of the parameter is set to the lower limit value of the cooling water on the inlet side of the refrigerator, which is determined in the refrigerator.

According to one aspect of the present invention, the parameter is the outside air wet-bulb temperature, the upper limit of the value taken by the parameter is set to the outside air wet-bulb temperature at a predetermined high temperature, and the value taken by the parameter is set to a value obtained by subtracting a predetermined approach temperature from the lower limit value of the cooling water on the inlet side of the cooling machine determined in the cooling machine to which the cooling water is supplied.

According to one aspect of the invention, the fan is a fixed speed fan.

According to one aspect of the present invention, after starting the number of the fans by the number of the fans to be initially started and starting the operation of the cooling tower, the target temperature of the cooling water and the temperature of the cooling water The number of fans to be activated is adjusted by feedback control based on the deviation from the measured value.

According to one aspect of the present invention, a heat source system includes a cooling tower to which a plurality of fans are connected, and any of the controllers described above.

According to one aspect of the present invention, the method for determining the number of fans to be activated includes a range of values taken by a parameter of the operating environment of the cooling tower in which a control device of a cooling tower to which a plurality of fans are connected affects temperature control of the cooling water. and determining the initial number of fans to be activated when the cooling tower is started, based on the number of fans and the value of the parameter when the cooling tower is started.

According to one aspect of the present invention, a program instructs a computer controlling a cooling tower to which a plurality of fans are connected to have ranges of values taken by parameters of the operating environment of the cooling tower that affect cooling water temperature control, It functions as means for determining the initial number of fans to be activated when the cooling tower starts operating, based on the number of fans and the value of the parameter when the cooling tower starts operating.

According to the control device, heat source system, method and program for determining the number of activated fans, an appropriate initial number of cooling tower fans to be activated can be determined.

It is a figure which shows the structural example of the heat-source system which concerns on 1st embodiment and 2nd embodiment. 7 is a flow chart showing an example of processing for determining the number of fans to be initially activated in the first embodiment. It is a figure explaining the process which determines the initial starting number of fans in 1st embodiment. 7 is a flow chart showing an example of control of the number of activated fans in the first embodiment. 9 is a flow chart showing an example of processing for determining the number of fans to be initially activated in the second embodiment. It is a figure which shows the other structural example of the heat-source system which concerns on 1st embodiment and 2nd embodiment. It is a figure which shows an example of the hardware constitutions of the control apparatus in 1st embodiment and 2nd embodiment.

<Configuration of heat source system>
Hereinafter, heat source systems according to the first embodiment and the second embodiment will be described.
FIG. 1 is a diagram showing a configuration example of a heat source system according to a first embodiment and a second embodiment.
The cooling system 1 includes a control device 10, N cooling towers 201 to 20N, N cooling water pumps 301 to 30N, pipes 311a to 31Na, pipes 311b to 31Nb, and N refrigerators 401 to 40N. The cooling tower 201 has four fans, fans 211a to 211d. The fans 211a to 211d are fans for guiding outside air used for cooling the cooling water into the cooling tower.
Similarly, the cooling tower 202 has fans 212a to 212d, and the cooling tower 20N has fans 21Na to 21Nd. Fans 211a to 211d, fans 212a to 212d, and fans 21Na to 21Nd are all fixed-speed fans.

In the cooling system 1, one cooling tower is configured to supply cooling water to one refrigerator. For example, the refrigerator 401, the pipe 311a, the cooling tower 201, the pipe 311b, etc. constitute one cooling subsystem. The cooling tower 201 and the refrigerator 401 are connected by pipes 311a and 311b, and a cooling water pump 301 is provided in the pipe 311b. Cooling water circulates through this cooling subsystem. For example, by driving the cooling water pump 301 , the cooling water cooled in the cooling tower 201 is sucked into the cooling water pump 301 via 311 b and sent to the refrigerator 401 . The cooling water is used in refrigerator 401 to raise its temperature. The cooling water after use is returned to the cooling tower 201 via the pipe 311a. The control device 10 controls the rotation speed of the cooling water pump 301 according to the magnitude of the load and the like. This adjusts the flow rate of the circulating cooling water.

The pipes 311a and 311b are provided with a bypass pipe line 321 that connects the pipes 311a and 311b. The bypass pipe 321 is provided with a bypass valve 331 that adjusts the flow rate of cooling water flowing through the bypass pipe 321 . By adjusting the opening degree of the bypass valve 331 by the control device 10, part of the used cooling water sent from the refrigerator 401 does not return to the cooling tower 201. is sent to the upstream side of

Further, a temperature sensor 341 for measuring the temperature of the cooling water after being used in the refrigerator 401 is provided on the pipe 311a. The temperature measured by the temperature sensor 341 is called a cooling water outlet temperature To1. A temperature sensor 351 that measures the temperature of the cooling water supplied to the refrigerator 401 is provided in the pipe 311b. The temperature measured by the temperature sensor 351 is called a cooling water inlet temperature Ti1. Temperature sensors 341 and 351 output the measured temperatures to control device 10 .
The cooling system 1 is also provided with a temperature/humidity sensor 361 capable of measuring the outside air wet-bulb temperature. The temperature/humidity sensor 361 outputs the measured outside air wet-bulb temperature to the control device 10 .

As shown in FIG. 1, the configuration of the cooling subsystem including the cooling tower 202 and the refrigerator 402 that supply cooling water to the refrigerator 402, the cooling tower 20N that supplies cooling water to the refrigerator 40N, and the cooling sub system including the refrigerator 40N The configuration of the system is the same as that of the cooling subsystem in which the cooling tower 201 supplies cooling water to the refrigerator 401 described above.

A bypass pipe line 322 is also provided for the pipes 312 a and 312 b provided between the cooling tower 202 and the refrigerator 402 , and the bypass pipe line 322 is provided with a bypass valve 332 . A bypass pipeline 32N is provided to connect the pipes 31Na and 31Nb, and the bypass pipeline 32N is provided with a bypass valve 33N. Further, the pipe 312a is provided with a temperature sensor 342 for measuring the cooling water outlet temperature To2, and the pipe 312b is provided with a temperature sensor 352 for measuring the cooling water inlet temperature Ti2. The pipe 31Na is provided with a temperature sensor 34N for measuring the cooling water outlet temperature ToN, and the pipe 31Nb is provided with a temperature sensor 35N for measuring the cooling water inlet temperature TiN. Each of these temperature sensors 342 and the like outputs the measured temperature to the control device 10 .

The control in the cooling subsystem including the cooling tower 201 and the refrigerator 401 will be described below as an example, but the same applies to other cooling subsystems. Fans 211a to 211d connected to cooling tower 201 may be collectively referred to as fan 211. FIG.

The control device 10 controls operations of the cooling tower 201 , the cooling water pump 301 and the bypass valve 331 . For example, the control device 10 controls starting and stopping of each of the cooling towers 201 to 20N. In addition, the control device 10 determines how many of the fans 211a to 211d provided in the cooling tower 201 should be activated, and activates the determined number of fans 211. FIG. Particularly in this embodiment, the control device 10 determines how many fans 211 to start when the cooling tower 201 starts operating.

The control device 10 is composed of a computer such as a PLC (Programmable Logic Controller) or a microcomputer. The control device 10 includes a sensor information acquisition unit 11 , an initial activation number determination unit 12 , a fan control unit 13 , and a storage unit 14 . The control device 10 may have various other functions, but the description of the functions unrelated to the control of the number of operating fans 211 will be omitted.

The sensor information acquisition unit 11 acquires measured values measured by each sensor from the temperature sensors 341 and 351 and the temperature/humidity sensor 361 .
The initially activated number determining unit 12 determines the number of fans 211 to be activated when the cooling tower 201 starts operating (hereinafter referred to as the initially activated number). Specifically, the initially activated number determining unit 12 determines the value range of a predetermined parameter that affects cooling water temperature control among the parameters of the operating environment of the cooling tower 201 and the values of the fans 211 connected to the cooling tower 201 , and the value of the parameter when the cooling tower 201 is started, the number of fans 211 to be initially started is determined. As will be described later, the parameters that affect the temperature control of the cooling water are, for example, the temperature of the cooling water and the outside air wet-bulb temperature of the location where the cooling system 1 is operated.

Since the fan 211 is a fixed-speed fan, the cooling capacity increases as the number of the fans 211 activated increases. For example, if the cooling water temperature is high, a relatively large number of fans 211 need to be activated to supply cooling water at the target temperature, and if the cooling water temperature is low, a relatively small number of fans 211 need to be activated. In the case of the outside air wet-bulb temperature, in order to supply cooling water at the target temperature, if the outside air wet-bulb temperature is high, a relatively large number of fans 211 need to be started, and if the outside air wet-bulb temperature is low, a relatively small number of fans 211 must be started. It is sufficient to start the fan 211 of .

The fan control unit 13 controls the starting and stopping of the fan 211 . For example, the fan control unit 13 starts the fans 211 by the number of fans 211 determined by the initial activation number determination unit 12 when the cooling tower 201 starts operating.
The storage unit 14 stores various information such as various thresholds.

<First embodiment>
Next, a method for determining the initial number of fans 211 to be activated in the first embodiment will be described.
FIG. 2 is a flowchart showing an example of processing for determining the number of fans to be initially activated in the first embodiment.
For example, assume that the operation of the cooling tower 201 is started in order to start supplying cooling water to the refrigerator 401 .
A rated cooling water inlet temperature T1 is set in the refrigerator 401, and the cooling water inlet temperature Ti1 measured by the temperature sensor 341 is controlled to a predetermined target temperature Tα. A lower limit value TL is set for the cooling water inlet temperature Ti1 in order to operate the refrigerating cycle of the refrigerator 401 normally. These rated cooling water inlet temperature T1 and cooling water inlet temperature lower limit value TL are registered in the storage unit 14 in advance. The control device 10 performs start/stop control of the fans 211a to 211d of the cooling tower 201 so that the cooling water inlet temperature Ti1 becomes the target temperature Tα.
Further, the sensor information acquisition unit 11 acquires the temperature of the cooling water measured by each sensor at predetermined time intervals from the temperature sensors 341 and 351, and records it in the storage unit 14 together with the acquired time.

First, the initially activated number determining unit 12 calculates the range of cooling water temperature (step S11). Specifically, the initially activated number determination unit 12 calculates the difference between the upper limit value Tmax and the lower limit value Tmin of the cooling water temperature, and defines the calculated difference as the range of the cooling water temperature. Here, the upper limit value Tmax of the coolant temperature is set to the rated coolant inlet temperature T1 of the refrigerator 401 . In addition, the lower limit value Tmin of the cooling water temperature is set to the cooling water inlet temperature lower limit value TL of the refrigerator 401 . The initially activated number determination unit 12 reads the rated cooling water inlet temperature T1 and the cooling water inlet temperature lower limit value TL from the storage unit 14, and determines the cooling water inlet temperature lower limit value TL from the cooling water inlet temperature T1 (upper limit value Tmax). (lower limit value Tmin) is subtracted to calculate the range of cooling water temperature.

Next, the initially activated number determination unit 12 calculates a threshold value for determining the number of initially activated fans (step S12). Specifically, (1) first, the initially activated number determining unit 12 divides the cooling water temperature range calculated in step S11 by the number of fans 211 connected to the cooling tower 201 (formula A).
Fan operating point threshold ΔT [°C/point] = (Tmax-Tmin)/number of fans 211 connected to cooling tower 201 to start operation (A)

(2) Next, the initially activated number determining unit 12 calculates a threshold corresponding to the number of initially activated fans by adding the fan operating point threshold value ΔT stepwise to the lower limit value Tmin. For example, since the cooling tower 201 has four fans 211a to 211d, each threshold is determined as follows according to the number of fans to be activated.
Threshold value T0 = lower limit value Tmin
Threshold T1 = lower limit Tmin + fan operating point threshold ΔT x (2-1)
Threshold value T2 = lower limit value Tmin + fan operating point threshold value ΔT x (3-1)
Threshold value T3 = lower limit value Tmin + fan operating point threshold value ΔT x (4-1)
Threshold value T4 = upper limit value Tmax
The initially activated number determination unit 12 records the thresholds T0 to T4 in the storage unit.

Here, the relationship between the thresholds T0 to T3 and the number of fans 211 that are initially activated will be described with reference to FIG. FIG. 3 is a diagram illustrating processing for determining the initial number of fans to be activated in the first embodiment.
The vertical axis of the graph shown in FIG. 3 indicates the number of initially activated fans 211, and the horizontal axis indicates the cooling water inlet temperature. A graph L1 shows the relationship between the cooling water inlet temperature Ti1 and the number of vehicles initially started. Specifically, in graph L1, the range of cooling water inlet temperature Ti1 and the number of initially activated fans 211 are associated. For example, based on the graph L1, if the value of the cooling water inlet temperature Ti1 is Ta°C, the number of fans 211 that are initially activated is 1, if Tb°C, 2, if Tc°C, 3, and if Td°C. If there is, it will be like 4 units. That is, in this example, the relationship between the cooling water inlet temperature Ti and the number of fans 211 that are initially activated is as follows.
Threshold T0 ≤ Cooling water inlet temperature Ti < Threshold T1, 1 unit Threshold T1 ≤ Cooling water inlet temperature Ti < Threshold T2, 2 units Threshold T2 ≤ Cooling water inlet temperature Ti < Threshold T3, 3 units Threshold T3 ≤ cooling water inlet temperature Ti ≤ threshold value T4, 4 units

After calculating the threshold corresponding to each number of initially activated units, the initially activated number determining unit 12 acquires the cooling water inlet temperature Ti at the start of operation of the cooling tower 201 (step S13). The initially activated number determining unit 12 acquires the cooling water inlet temperature Ti1 measured by the temperature sensor 341 when the cooling tower 201 starts operating, from the sensor information acquiring unit 11 .

Next, the initially activated number determining unit 12 determines the initially activated number of fans 211 based on the cooling water inlet temperature Ti1 at the start of operation of the cooling tower 201 acquired in step S13 and the threshold calculated in step S12. The initially activated number determining unit 12 determines the initially activated number of fans 211 based on the cooling water inlet temperature Ti1 and the threshold values T0 to T4, as described with reference to FIG. 3 (step S14). The fan control unit 13 activates the number of fans 211 determined by the initial activation number determination unit 12 .
As described above, according to the present embodiment, cooling is performed based on the range of possible values of the cooling water inlet temperature, the number of fans 211 connected to the cooling tower 201, and the cooling water inlet temperature at the start of the cooling tower operation. The initial number of tower fans to start can be determined. As a result, it is possible to prevent excess or deficiency in the cooling capacity from the initial start-up of the cooling tower.

Next, the start/stop control of the fan 211 in operation will be described using the cooling tower 201 as an example.
FIG. 4 is a flowchart showing an example of control of the number of activated fans according to the first embodiment.
As a premise, it is assumed that the operation of the cooling tower 201 is started by activating the initial number of fans 211 determined by the processing described with reference to FIG.
First, the fan control unit 13 acquires the current cooling water inlet temperature Ti1 measured by the temperature sensor 341 from the sensor information acquiring unit 11 (step S21).
Next, the fan control unit 13 calculates the deviation between the target temperature Tα of the cooling water inlet temperature and the current cooling water inlet temperature Ti1 obtained in step S21 (step S22). Next, the fan control unit 13 controls the number of activated fans 211 based on the deviation calculated in step S22 (step S23). For example, if the deviation is within a predetermined allowable range, the fan control unit 13 maintains the current number of activated fans. For example, if the current cooling water inlet temperature Ti1 is higher than the target temperature Tα beyond the allowable range, the fan control unit 13 increases the number of fans 211 to be activated by one. Conversely, if the current cooling water inlet temperature Ti1 is lower than the target temperature Tα beyond the allowable range, the fan controller 13 reduces the number of fans 211 to be activated by one.
During operation of the cooling tower 201, the fan control unit 13 repeats the processing of steps S21 to S23 at a predetermined control cycle. Feedback control such as PID control, for example, can be used for the processing of steps S22 to S23.

By such feedback control, the value of the cooling water inlet temperature Ti1 can be quickly controlled to reach the target temperature Tα, and operation can be performed with the optimum number of fans to be activated. The control of the number of activated fans illustrated in FIG. 4 is a control that can efficiently and quickly bring the cooling water inlet temperature Ti1 to the target temperature Tα. is controlled to the target temperature Tα, and there is a possibility that the fan 211 may start and stop unnecessarily. 2 and 3, the appropriate number of fans 211 can be started. can drive.

<Second embodiment>
In the first embodiment, the initial number of fans 211 to be activated is determined based on the cooling water inlet temperature. In the second embodiment, the number of fans to be initially activated is determined based on the outside air wet-bulb temperature.
FIG. 5 is a flowchart showing an example of processing for determining the number of fans to be initially activated in the second embodiment.
Assume that the operation of the cooling tower 201 is started as in the case of FIG. In the storage unit 14, an upper limit value Wmax and a lower limit value Wmin of the outside air wet-bulb temperature are registered. The upper limit Wmax of the outside air wet-bulb temperature is, for example, the outside air wet-bulb temperature measured at the highest time such as summer in the place where the cooling system 1 is operated, or the upper limit set when the cooling tower 201 is designed. set. A value obtained by subtracting the cooling tower approach temperature from the cooling water inlet temperature lower limit TL is set as the lower limit Wmin of the outside air wet-bulb temperature. The cooling tower approach temperature indicates the difference between the cooling water outlet temperature (eg, a given lower limit) and the outside air wet-bulb temperature (eg, the above upper limit).
The sensor information acquisition unit 11 acquires the outside air wet-bulb temperature Wi measured by the temperature/humidity sensor 361 at predetermined time intervals from the temperature/humidity sensor 361, and records it in the storage unit 14 together with the acquired time.

First, the initially activated number determining unit 12 calculates the range of outside air wet-bulb temperature (step S31). Specifically, the initially activated number determination unit 12 reads the upper limit value Wmax and the lower limit value Wmin of the outside air wet bulb temperature from the storage unit 14, calculates the difference between them (Wmax−Wmin), and uses the calculated value as the outside air humidity. Sphere temperature range.

Next, the initially activated number determination unit 12 calculates a threshold for determining the number of initially activated fans (step S32). Specifically, (1) first, the initially activated number determining unit 12 divides the range of values taken by the outside air wet-bulb temperature calculated in step S31 by the number of fans connected to the cooling tower 201 (formula B ).
Fan operating point threshold ΔW [°CWB/point] = (Wmax-Wmin)/number of fans 211 connected to cooling tower 201 to start operation (B)

(2) Next, the initially activated number determining unit 12 calculates a threshold corresponding to the number of initially activated fans by adding the fan operating point threshold value ΔW to the lower limit value Wmin step by step. For example, since the cooling tower 201 has four fans 211a to 211d, each threshold is determined as follows according to the number of fans to be activated.
Threshold value W0 = lower limit value Wmin
Threshold value W1 = lower limit value Wmin + fan operating point threshold value ΔW × (2-1)
Threshold value W2 = lower limit value Wmin + fan operating point threshold value ΔW × (3-1)
Threshold value W3 = lower limit value Wmin + fan operating point threshold value ΔW × (4-1)
Threshold value W4 = upper limit value Wmax
The initially activated number determination unit 12 records the thresholds W0 to W4 in the storage unit.

Similarly to the first embodiment, the relationship between the outside air wet-bulb temperature Wi measured by the temperature and humidity sensor 361 and the number of fans in operation is as follows.
Threshold W0 ≤ Outside air wet-bulb temperature Wi < Threshold W1, 1 unit Threshold W1 ≤ Outside air wet-bulb temperature Wi < Threshold W2, 2 units Threshold W2 ≤ Outside air wet-bulb temperature Wi < Threshold W3, 3 units Threshold W3 ≤ outside air wet bulb temperature Wi ≤ threshold value W4, 4 units

After calculating the threshold value corresponding to each number of initially activated units, the initially activated number determining unit 12 acquires the outside air wet-bulb temperature Wi at the start of operation of the cooling tower 201 (step S33). The initially activated number determination unit 12 acquires the outside air wet-bulb temperature Wi measured by the temperature/humidity sensor 361 when the cooling tower 201 starts operating from the sensor information acquisition unit 11 .

Next, the initially activated number determination unit 12 determines the first embodiment based on the outside air wet-bulb temperature Wi at the start of operation of the cooling tower 201 acquired in step S33 and the threshold value corresponding to the initially activated number calculated in step S32. 3, the number of fans 211 to be initially activated is determined (step S34). The fan control unit 13 activates the number of fans 211 determined by the initial activation number determination unit 12 .
As described above, according to the present embodiment, the number of fans 211 to be initially activated can be determined based on the outside air wet-bulb temperature Wi measured near the cooling tower 201 and the refrigerator 401 when the cooling tower starts operating. .

Further, the method of determining the number of fans to be initially activated in the first and second embodiments is not limited to the paired cooling system 1 illustrated in FIG. It is also possible to apply to
FIG. 6 is a diagram showing another configuration example of the heat source system according to the first embodiment and the second embodiment.
The cooling system 2 includes a control device 10a, cooling towers 21-23, cooling water pumps 31-3N, refrigerators 41-4N, a header 61 and a header 62. The cooling tower 21 includes fans 21a to 21d. The cooling tower 22 has fans 22a to 22d, and the cooling tower 23 has fans 23a to 23d. The fans 21a to 21d, the fans 22a to 22d, and the fans 23a to 23d are all fixed-speed fans.

In the cooling system 2, a plurality of cooling towers 21-23 are configured to supply cooling water to a plurality of refrigerators 41-4N. For example, pipes for supplying cooling water from the cooling towers 21 to 23 are connected to the header 62 , and the cooling water cooled by the cooling towers 21 to 23 is concentrated in the header 62 . The cooling water pumps 31-3N suck cooling water from the header 62 and discharge it to the refrigerators 41-4N, respectively. Cooling water that has undergone heat exchange with cold water supplied to external loads by the refrigerators 41 to 4N is sent out from the refrigerators 41 to 4N and reaches the header 61 . The used cooling water collected by the header 61 is sent to the cooling towers 21 to 23 and cooled again. A bypass line connecting the forward line and the return line through which cooling water supplied to the refrigerator 41 passes is provided, and a bypass valve 51 is provided in the bypass line. Bypass pipes are similarly provided for the incoming pipes and the return pipes of the refrigerator 42 and the refrigerator 4N, and bypass valves 52 and 5N are provided in the respective bypass pipes. The control device 10a activates and operates the number of cooling towers among the cooling towers 21 to 23 corresponding to the load required by the refrigerators 41 to 4N. The control device 10a has the functions of the control device 10 described in the first embodiment or the second embodiment. Then, for example, when starting the operation of the cooling tower 21, the control device 10a starts up the required number of the fans 21a to 21d (the number of initially activated fans calculated by the method of the first embodiment or the second embodiment). After that, for example, the number of fans 21a to 21d is adjusted by feedback control illustrated in FIG.

According to the first embodiment and the second embodiment, for the cooling towers included in the paired cooling system illustrated in FIG. 1 and the integrated cooling system illustrated in FIG. can determine the number of initial activations. If time is taken, the number of operating fans can be set to an appropriate number during operation of the cooling tower by a predetermined control. However, if the initial number of fans to be started at the start of operation of the cooling tower is inappropriate, the cooling capacity will be insufficient and the necessary cooling capacity cannot be obtained, or if the cooling capacity is excessive, energy will be wasted. If it is necessary, or if the cooling water temperature drops too much, problems such as the refrigerator not being able to start may occur. According to the first embodiment and the second embodiment, an appropriate number of fans can be activated from the start of operation of the cooling tower, thereby preventing problems and wasting energy.
Although the number of fans connected to the cooling tower 201 varies, the operating point threshold value obtained by dividing by the number of fans 211 connected to the cooling tower 201 is used as shown in Equations A and B. The methods for determining the number of activated fans according to the first embodiment and the second embodiment can be applied to the cooling tower 201 having any number of fans.

FIG. 7 is a diagram showing an example of the hardware configuration of the control device in the first embodiment and the second embodiment.
A computer 900 includes a CPU 901 , a main memory device 902 , an auxiliary memory device 903 , an input/output interface 904 and a communication interface 905 .
The control device 10 described above is implemented in a computer 900 . Each function described above is stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads out the program from the auxiliary storage device 903, develops it in the main storage device 902, and executes the above processing according to the program. Also, the CPU 901 secures a storage area in the main storage device 902 according to the program. In addition, the CPU 901 secures a storage area for storing data being processed in the auxiliary storage device 903 according to the program.

A program for realizing all or part of the functions of the control device 10 is recorded on a computer-readable recording medium, and the program recorded on this recording medium is read by a computer system and executed. Processing by the functional unit may be performed. The "computer system" here includes hardware such as an OS and peripheral devices. The "computer system" also includes the home page providing environment (or display environment) if the WWW system is used. The term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, and storage devices such as hard disks incorporated in computer systems. Further, when this program is distributed to the computer 900 via a communication line, the computer 900 receiving the distribution may develop the program in the main storage device 902 and execute the above process. Further, the above program may be for realizing a part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in the computer system. . Note that the control device 10 may be configured by a plurality of computers 900 .

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

For example, the number of initially activated fans 211 may be calculated by both the methods of the first embodiment and the second embodiment, and the weighted average of the respective initially activated numbers may be used as the final initially activated number.
Also, the number of fans connected to one cooling tower is not limited to four. It may be 2 or 3, or 5 or more. Further, the control of the number of fans to be activated after the operation is started with the number of fans to be activated in the initial stage is not limited to the feedback control shown in FIG. Even in the case of other control methods, the method of determining the number of initially activated machines according to this embodiment is effective.
The cooling systems 1 and 2 are examples of heat source systems.

Reference Signs List 1, 2 Cooling system 10, 10a Control device 11 Sensor information acquisition unit 12 Initial startup number determination unit 13 Fan control unit 14 Storage unit 21, 22, 23, 201, 202, 20N Cooling tower 31, 32, 3N, 301, 302, 301N Cooling water pump 311a-31Na, 311b-31Nb Piping 41-4N, 401-401N Refrigerators 21a to 21d, 22a to 22d, 23a to 23d Fans 211a to 211d, 212a to 212d, 21Na to 21Nd Fans 51, 52, 5N, 331, 332, 33N Bypass valves 321, 322, 32N Bypass pipeline 341, 351, 342, 352, 34N, 35N Temperature sensor 361 Temperature and humidity sensor 61, 62 Header 900 Computer 901 CPU
902 Main storage device 903 Auxiliary storage device 904 Input/output interface 905 Communication interface

Claims (9)

A control device for a cooling tower to which a plurality of fans are connected,
Based on the range of values taken by parameters of the operating environment of the cooling tower that affect cooling water temperature control, the number of fans, and the values of the parameters at start-up of the cooling tower,
Determining the initial number of fans to be started when the cooling tower starts operating;
Control device. When the value obtained by dividing the value range of the parameter by the number of fans is set as the operating point threshold, and the number of initially activated fans is P,
Regarding the value Q of the parameter at the start of operation of the cooling tower,
When the lower limit value of the range + the operating point threshold value x (P-1) ≤ Q < the lower limit value of the range + the operating point threshold value x (P) is established, the number of initially activated vehicles is determined to be P.
A control device according to claim 1 . The cooling water temperature at the inlet of the refrigerator to which the cooling water is supplied, the upper limit of the value taken by the parameter is set to a predetermined rated cooling water inlet temperature, and the lower limit of the value taken by the parameter. is set to the lower limit value of the cooling water on the inlet side of the refrigerator determined in the refrigerator,
The control device according to claim 1 or 2. The parameter is the outside air wet-bulb temperature, the upper limit of the value taken by the parameter is set to the outside air wet-bulb temperature at a predetermined high temperature, and the lower limit of the value taken by the parameter is the cooling water A value obtained by subtracting a predetermined approach temperature from the lower limit value of the cooling water on the inlet side of the cooling water of the refrigerator determined in the refrigerator to which the cooling water is supplied is set.
The control device according to claim 1 or 2. wherein the fan is a fixed speed fan;
The control device according to any one of claims 1 to 4. After starting the operation of the cooling tower by activating the number of the fans by the initial activation number,
adjusting the number of fans to be activated by feedback control based on the deviation between the target temperature of the cooling water and the measured value of the temperature of the cooling water;
The control device according to any one of claims 1 to 5. a cooling tower to which a plurality of fans are connected; a control device according to any one of claims 1 to 6;
Heat source system including. A control device for a cooling tower with multiple fans connected to it,
the cooling tower based on the range of values taken by parameters of the operating environment of the cooling tower that affect cooling water temperature control, the number of fans, and the values of the parameters at the start of operation of the cooling tower; Determining the initial number of fans to be activated at the start of operation of
A method for determining the number of activated fans. A computer controlling a cooling tower with multiple fans connected
Based on the range of values taken by parameters of the operating environment of the cooling tower that affect cooling water temperature control, the number of fans, and the values of the parameters at start-up of the cooling tower,
means for determining the initial number of fans to be started when the cooling tower starts operating;
A program to function as

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