JP6599182B2 - Cooling tower control device, cooling tower control method, and heat source system - Google Patents

Description

  The present invention relates to a heat source system, and more particularly to a cooling tower control apparatus and method for controlling a cooling tower included in the heat source system.

  Conventionally, a method disclosed in Patent Document 1 below is known as a method for controlling a cooling tower in a heat source system. Patent Document 1 discloses a method of preventing a high condensing pressure failure caused by an increase in refrigerant temperature by increasing the coolant flow rate for a predetermined time after starting the turbo refrigerator.

JP2012-229823A

  However, in the method of Patent Document 1, when the control is started from a state where the chilled water load is high, the cooling water temperature starts to rise slightly after the performance of the refrigerator, and the fan frequency of the cooling tower is proportional to it. It rises. For this reason, there is a delay in raising the fan frequency of the cooling tower with respect to the performance of the refrigerator. As a result, if the coolant temperature rises and the coolant flow rate only increases, the cooling of the refrigerant will not be in time, and a high condenser pressure may occur, and the problem of preventing the condenser high pressure cannot be solved. It was.

  This invention is made in view of such a situation, Comprising: The delay in cooling of cooling water is made as small as possible, the condenser pressure height of a refrigerator is prevented, and a refrigerator trip can be prevented. It aims at providing a cooling tower control device, a cooling tower control method, and a heat source system.

In order to solve the above problems, the present invention employs the following means.
The present invention is a cooling applied to a heat source system including a refrigerator having a condenser that cools a refrigerant with cooling water, and a cooling tower that is connected to the refrigerator and rotates a fan to cool the cooling water. In the tower control device, the first target temperature is a target temperature when the cooling water is cooled by normal control, and the cooling water inlet at the inlet of the refrigerator for a first predetermined period from the start of the refrigerator. set than the preset first target temperature the target temperature to the first predetermined temperature lower second target temperature, set the fan frequency of the cooling tower, and / or fans start number based on the second target temperature A cooling tower control device is provided.

According to the present invention, during the first predetermined period from the start of the refrigerator, the cooling water inlet target temperature at the refrigerator inlet is set to the second target temperature that is lower than the preset first target temperature by the first predetermined temperature. Based on the second target temperature, the fan frequency of the cooling tower and / or the number of fans started is set.
That is, during the first predetermined period from the time of starting the refrigerator, the cooling water inlet target temperature is offset to the second target temperature, so that the fan frequency of the cooling tower is increased in advance and / or the number of fans started As the air volume is increased, the cooling capacity of the cooling water is increased. Thus, by controlling the fan frequency and / or the number of fans started in advance with the start of the refrigerator, the cooling delay of the cooling water in the cooling tower is made as small as possible and the refrigerator is condensed. Refrigerator tripping can be avoided. The outside air temperature is preferably measured by an outside air wet bulb thermometer. The first target temperature set in advance is a temperature set in a normal usage mode, for example, a target temperature set according to the outside air temperature.

  In the cooling tower control device, the cooling water inlet target temperature may be changed from the second target temperature to the first target temperature after the first predetermined period has elapsed since the start of the refrigerator.

  Thereby, the offset of the cooling water inlet target temperature can be canceled easily and the cooling water inlet target temperature can be returned to the first target temperature.

  In the cooling tower control device, the cooling water inlet target temperature may be set to the first target temperature when the temperature change of the cooling water inlet temperature at the inlet of the refrigerator is not more than a predetermined range.

When changing to the first target temperature depending on whether or not the first predetermined period has elapsed, the target temperature of the cooling water inlet is set to the first target although the performance of the refrigerator is not manifested in the cooling water temperature. Despite the possibility of returning to the temperature and the ability of the refrigerator to be manifested in the cooling water temperature, the cooling tower is operated at an excessive fan frequency and / or the number of fans started to consume extra power. There is a possibility that.
According to the present invention, the cooling water inlet target temperature is set to a preset first target temperature after it is determined that the temperature change of the cooling water inlet temperature is not more than the predetermined range, that is, the cooling water inlet temperature is stable. Therefore, the target temperature is prevented from changing too early or too late, the target temperature is changed at an appropriate timing, and the condenser pressure is prevented from increasing, thereby preventing an increase in the refrigerator trip and power consumption.

  The present invention is a cooling applied to a heat source system including a refrigerator having a condenser that cools a refrigerant with cooling water, and a cooling tower that is connected to the refrigerator and rotates a fan to cool the cooling water. In the tower control device, the fan frequency of the cooling tower is set to a frequency higher than a predetermined frequency when cooling water is normally cooled for a second predetermined period from the start of the refrigerator, and / or the cooling There is provided a cooling tower control apparatus in which the number of startup fans of the tower is set to be larger than the startup number of the fans when cooling water is normally cooled.

  According to the configuration of the present invention, the fan frequency of the cooling tower is set to a frequency higher than the predetermined frequency when the cooling water is normally cooled and / or cooled for the second predetermined period from the start of the refrigerator. The number of fan startups in the tower is set to be greater than the number of fan startups when cooling water is normally cooled. Since the output of the cooling tower is output later in accordance with the output of the refrigerator, the cooling water temperature rises with the start of the refrigerator. According to the present invention, the fan frequency is maintained for the second predetermined period from the start of the refrigerator. By setting a higher frequency and / or setting a larger number of fans to be activated, it is possible to cool the cooling water in advance and to prepare for a rise in the cooling water temperature that occurs late.

The cooling tower control device may change the fan frequency of the cooling tower from a frequency higher than the predetermined frequency to the predetermined frequency after the second predetermined period has elapsed since the start of the refrigerator.
Thereby, the offset of the fan frequency can be canceled easily.

The cooling tower control device changes the startup number of fans of the cooling tower to the startup number of the fans when cooling water is normally cooled after the second predetermined period has elapsed since the startup of the refrigerator. Also good.
Thereby, the starting number of fans can be easily restored.

  The cooling tower control device sets the fan frequency of the cooling tower from a frequency higher than the predetermined frequency to the predetermined frequency when the temperature change of the cooling water inlet temperature at the inlet of the refrigerator is below a predetermined range. May be.

When it is determined that the fan frequency is to be changed depending on whether or not the second predetermined period has elapsed, it is returned to the predetermined frequency at an early stage even though the ability of the refrigerator is not manifested in the cooling water temperature. In spite of the fact that the capacity of the refrigerator is manifested in the cooling water temperature, the cooling tower is operated at an excessive fan frequency and / or more than the required number of fan startups, thereby generating excess power. There is a possibility of consumption.
According to the present invention, since it is determined that the cooling water inlet temperature is stable, the fan frequency of the cooling tower is set from a frequency higher than the predetermined frequency to the predetermined frequency, so that the frequency change is too early or too late. This can be carried out at an appropriate timing, and a refrigerator trip and an increase in power consumption can be prevented by preventing a high condenser pressure.

  In the cooling tower control device, when the temperature change of the cooling water inlet temperature at the inlet of the refrigerator is equal to or less than a predetermined range, the number of fans of the cooling tower is started, and the fans are started when the cooling water is normally cooled. The number may be changed.

  According to the present invention, after it is determined that the cooling water inlet temperature is stable, the fan frequency of the cooling tower is changed from the number of cooling tower fans started to the number of fans started when the cooling water is normally cooled. Therefore, it is possible to change the number of starting units at an appropriate timing without being too early or too late, and it is possible to prevent a refrigerator trip and an increase in power consumption due to prevention of a high condenser pressure.

  The present invention provides a heat source system comprising a refrigerator, a cooling tower connected to the refrigerator, and the cooling tower control device described above.

The present invention is a cooling applied to a heat source system including a refrigerator having a condenser that cools a refrigerant with cooling water, and a cooling tower that is connected to the refrigerator and rotates a fan to cool the cooling water. In the tower control method, the first target temperature is a target temperature when the cooling water is cooled by normal control, and the cooling water inlet at the inlet of the refrigerator for a first predetermined period from the start of the refrigerator. set than the preset first target temperature the target temperature to the first predetermined temperature lower second target temperature, set the fan frequency of the cooling tower, and / or fans start number based on the second target temperature A cooling tower control method is provided.

  The present invention is a cooling applied to a heat source system including a refrigerator having a condenser that cools a refrigerant with cooling water, and a cooling tower that is connected to the refrigerator and rotates a fan to cool the cooling water. A tower control method, wherein a fan frequency of the cooling tower is set to a frequency higher than a predetermined frequency when cooling water is normally cooled for a second predetermined period from the start of the refrigerator, and / or the cooling A cooling tower control method is provided in which the number of startup fans of the tower is set to be larger than the startup number of the fans when cooling water is normally cooled.

  The present invention has the effect that the cooling delay of cooling water can be made as small as possible and the condenser pressure high trip of the refrigerator can be prevented.

It is the figure which showed roughly the structure of the heat source system which concerns on the 1st Embodiment of this invention. It is a functional block diagram of the cooling tower control apparatus which concerns on the 1st Embodiment of this invention. It is the figure which showed roughly the structure of the control system of the heat-source system which concerns on the 1st Embodiment of this invention. It is an operation | movement flow of the cooling tower control apparatus which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the condenser pressure high trip which arises when not using the cooling tower control apparatus which concerns on the 1st Embodiment of this invention. It is an example of the figure which showed the time tendency (simulation result) of the fan frequency of the cooling tower when not using the cooling tower control apparatus which concerns on the 1st Embodiment of this invention. It is an example of the figure which showed the time tendency (simulation result) of the fan frequency of a cooling tower in the case of using the cooling tower control apparatus which concerns on the 1st Embodiment of this invention. It is an operation | movement flow of the cooling tower control apparatus which concerns on the modification of the 1st Embodiment of this invention. It is the figure which showed schematically the structure of the control system of the heat-source system which concerns on the 2nd Embodiment of this invention. It is an operation | movement flow of the cooling tower control apparatus which concerns on the 2nd Embodiment of this invention. It is the figure which showed schematically the structure of the heat-source system which concerns on the 3rd Embodiment of this invention. It is an operation | movement flow of the cooling tower control apparatus which concerns on the 3rd Embodiment of this invention.

Hereinafter, a cooling tower control device, a cooling tower control method, and a heat source system according to an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a diagram schematically showing a configuration of a heat source system according to the first embodiment of the present invention. As shown in FIG. 1, a heat source system 1 includes a refrigerator 2, three cooling towers 3 a, 3 b, 3 c that are connected in parallel with the refrigerator 2, and are cooled by cooling by a fan, and cooling towers 3 a, 3 b. , 3c, a cooling tower control device 4 is provided. Although FIG. 1 illustrates a case where three cooling towers are provided, the number of cooling towers is not limited. Note that the cooling tower is described as the cooling tower 3 unless otherwise specified.

The refrigerator 2 includes a condenser 21 and an evaporator 22.
The condenser 21 is connected to the cooling water piping of the outgoing piping 6 and the return piping 7, and the cooling water W <b> 1 cooled by the cooling towers 3 a, 3 b, 3 c is supplied via the cooling water piping, To cool the refrigerant.
The evaporator 22 is connected to cold water pipes 51 and 52, and cold water W2 is supplied from the external load 50 via the cold water pipes 51 and 52, and heat is exchanged between the cold water W2 and the refrigerant to evaporate. The cold water W2 cooled by the evaporator 22 is supplied to the external load 50.

Each cooling tower 3a, 3b, 3c cools the cooling water by the rotation of the fan. Each of the cooling towers 3a, 3b, 3c is connected to the refrigerator 2 via the forward piping 6, supplied with the cooling water used in the refrigerator 2, and returns the cooling water cooled by the cooling tower 3 to the piping 7 It supplies to the refrigerator 2 connected via.
The forward pipe 6 is provided with a water supply header 8, and the return pipe 7 is provided with a return water header 9. A cooling water pump 10 is provided downstream of the return water header 9 in the return pipe 7 in the cooling water flow. By adjusting the output of the cooling water pump 10, the cooling water W1 is circulated between the cooling towers 3a, 3b, 3c and the condenser 21. A bypass pipe 12 is provided between the water supply header 8 and the return water header 9. The bypass pipe 12 is provided with a cooling water bypass valve (bypass valve) 13. By adjusting the opening degree of the cooling water bypass valve 13, the flow rate of bypassing from the water supply header 8 to the return water header 9 is adjusted.

In the return pipe 7, on the downstream side of the coolant flow from the return water header 9, the temperature of the coolant that is cooled in the cooling towers 3 a, 3 b, 3 c and flows into the refrigerator 2 (hereinafter referred to as “cooling water inlet temperature T 3”). The temperature sensor 17 is provided for measuring. Information of the cooling water inlet temperature T3 measured by the temperature sensor 17 is output to the cooling tower control device 4.
The heat source system 1 includes wet bulb thermometers 23a, 23b, and 23c corresponding to the cooling towers 3a, 3b, and 3c. The wet bulb thermometers 23a, 23b, and 23c measure the wet bulb temperature of the outside air, and output information on the measured wet bulb temperatures to the cooling tower controller 4.

  The cooling tower control device 4 acquires information on the cooling water inlet temperature T3 detected by the temperature sensor 17, and information on the outside air wet bulb temperature measured by the wet bulb thermometers 23a, 23b, and 23c.

The cooling tower control device 4 is, for example, a computer, and exchanges information by communicating with a main storage device such as a CPU (Central Processing Unit), a RAM (Random Access Memory), an auxiliary storage device, and an external device. It has a communication device to perform.
The auxiliary storage device is a computer-readable recording medium, such as a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, or a semiconductor memory. Various programs are stored in the auxiliary storage device, and various processes are realized by the CPU reading and executing the program from the auxiliary storage device to the main storage device.

FIG. 2 is a functional block diagram showing an electrical configuration of the cooling tower control device 4.
The cooling tower control device 4 sets the cooling water inlet target temperature at the inlet of the refrigerator 2 to a second target temperature that is lower than the preset first target temperature by a first predetermined temperature for a first predetermined period from the start of the refrigerator 2. The fan frequency of the cooling towers 3a, 3b, 3c is set based on the second target temperature. The first target temperature set in advance is a temperature set in a normal usage mode, for example, a target temperature set according to the outside air temperature. In this embodiment, the target temperature set according to the outside air temperature will be described as the first target temperature.
Note that the cooling water inlet target temperature is set to the second target temperature in this way, for example, in Japan only when the outdoor wet bulb temperature is high, such as in summer. This is because when the outside air wet bulb temperature is high, the heat load is high and the cooling water temperature of the cooling tower tends to be high.

The cooling water inlet target temperature is generally determined by {(outside air wet bulb temperature) + (predetermined value α [° C.])}. However, in the present embodiment, {(outside air wet bulb temperature) + (predetermined value) Value α [° C.]) − (First predetermined temperature)}.
Thus, when the refrigerator 2 is started, the cooling water inlet target temperature is set lower than when cooling water is cooled by normal control (described later), so the fan frequency of the cooling tower 3 is set higher. It becomes.
In addition, the first predetermined period is considered as the time until the effect of the freezing capacity of the freezer is reflected in the temperature of the cooling water, taking into account that it takes time until the freezing capacity is exhibited after the start of the freezer. It shall be set based on.

Specifically, the cooling tower control device 4 includes a timer 41, a target temperature setting unit 42, a control unit 43, and a storage unit 44.
The storage unit 44 stores correspondence information in which the outside air temperature is associated with the first target temperature that is the cooling water inlet target temperature at the inlet of the refrigerator 2 that is set according to the outside air temperature. In addition, information on the first predetermined temperature is stored. The first predetermined temperature is an offset value (for example, 2 [° C.]) for lowering the temperature from the first target temperature to the second target temperature.
The first predetermined temperature is, for example, set to ± 0 ° C. until the wet bulb temperature exceeds the threshold, and increases at a constant rate as the wet bulb temperature increases after the threshold.

The timer 41 measures a predetermined period from the start of the refrigerator 2.
The target temperature setting unit 42 reads out the first target temperature corresponding to the acquired information about the outside wet bulb temperature (outside air temperature) based on the correspondence information in the storage unit 44, and uses the first predetermined temperature from the first target temperature. A small second target temperature is calculated and output to the control unit 43.
The control unit 43 sets the fan frequency of the cooling tower 3 based on the second target temperature acquired from the target temperature setting unit 42.

FIG. 3 shows a control system for controlling the fan frequency of the cooling tower 3.
The target temperature setting unit 42 selects the first target temperature as the cooling water inlet target temperature, and the second target after subtracting the offset value (first predetermined temperature) from the first target temperature as the cooling water inlet target temperature. It has the switching part 42a which switches the point B which selects temperature. For example, the switching unit 42a is connected to the point B side until the first predetermined period elapses from the time when the refrigerator 2 is started, and the period measured by the timer 41 is the refrigerator. 2 is connected to the point A side after the first predetermined period has elapsed from the time of activation.

The subtractor 45 calculates a difference between the first target temperature or the second target temperature selected by the switching unit 42 a and the cooling water inlet temperature T3 detected by the temperature sensor 17 and outputs the difference to the PI control unit 46.
The PI control unit 46 determines a fan frequency command value for the cooling tower 3 so as to reduce the deviation calculated by the subtracter 45, and outputs it to the control unit 43. In the present embodiment, the normal control means a case where the switching unit 42a is connected to the point A and PI control is performed.
The control unit 43 controls the cooling tower 3 based on the acquired fan frequency command value.

Processing executed by the cooling tower control device 4 according to the present embodiment will be described with reference to FIG. In the following description, the case where the fan frequency is used for controlling the cooling tower 3 will be described as an example.
It is determined whether or not the external wet bulb temperature detected by the wet bulb thermometers 23a, 23b, and 23c is equal to or higher than a second predetermined temperature (step SA1 in FIG. 4). When it is determined that the external wet bulb temperature is lower than the second predetermined temperature (No in step SA1 in FIG. 4), the switching unit 42a is connected to the A side, the cooling water inlet target temperature is set as the first target temperature, 1 A fan frequency command value is obtained as a control amount for PI control of the fan frequency so that the deviation between the target temperature and the cooling water inlet temperature T3 is reduced, and the cooling tower 3 is controlled based on the fan frequency command value (FIG. 4). Step SA7), returning to step SA1.
When it is determined that the external wet bulb temperature is equal to or higher than the second predetermined temperature (Yes in step SA1 in FIG. 4), it is determined whether or not a new refrigerator 2 has been started (step in FIG. 4). SA2).

When the new refrigerator 2 is not activated (No in step SA2 in FIG. 4), the process proceeds to step SA7. When the new refrigerator 2 is activated (Yes in step SA2 in FIG. 4), the switching unit 42a is connected to the B side, and the first target temperature is subtracted from the first target temperature as the cooling water inlet target temperature. 2 Calculate the target temperature (step SA3 in FIG. 4). A fan frequency command value is obtained as a control amount for PI control of the fan frequency so as to reduce the deviation between the second target temperature and the cooling water inlet temperature T3, and the cooling tower 3 is controlled based on the fan frequency command value. Since the second target temperature is lower than the first target temperature, the fan frequency of the cooling tower 3 is higher than when the first target temperature is selected as the cooling water inlet target temperature. Thereby, when the 2nd target temperature is selected, cooling of cooling water W1 progresses rather than the case where the 1st target temperature is selected. Further, since the fan frequency is increased in advance with the start of the refrigerator 2, there is no delay in cooling the cooling water W1.
Further, when the new refrigerator 2 is activated, the timer 41 is activated, and the period after the new refrigerator 2 is activated is measured (step SA4 in FIG. 4).

It is determined whether or not the first predetermined period has elapsed since the start of the new refrigerator 2 (step SA5 in FIG. 4). If the first predetermined period has not elapsed (No in step SA5 in FIG. 4), it is determined whether or not a refrigerator trip has occurred (step SA6 in FIG. 4). If a refrigerator trip has occurred (Yes in step SA6 in FIG. 4), the process proceeds to step SA7. If a refrigerator trip has not occurred (No in step SA6 in FIG. 4), the process returns to step SA5. The determination whether or not the first predetermined period has elapsed is repeated.
On the other hand, when the first predetermined period has elapsed in Step SA5 (Yes in Step SA5 in FIG. 4), the process proceeds to Step SA7, where the switching unit 42a is connected to the A side and the first target temperature is set as the cooling water inlet target temperature. The temperature is selected and the process returns to step SA1.

As described above, according to the cooling tower control device 4, the cooling tower control method, and the heat source system 1 according to this embodiment, the cooling water at the inlet of the refrigerator is the first predetermined period from the start of the refrigerator 2. The inlet target temperature is set to a second target temperature that is a first predetermined temperature lower than the first target temperature that is set according to the outdoor wet bulb temperature, and the fan frequency of the cooling tower 3 is set based on the second target temperature. .
That is, since the cooling water inlet target temperature is multiplied by the offset value and set to the second target temperature during the first predetermined period from the start of the refrigerator 2, the fan frequency of the cooling tower 3 is increased in advance to increase the air volume. The cooling capacity of the cooling water W1 is increased. Thus, by controlling the fan frequency of the cooling tower 3 in advance with the start-up of the refrigerator 2, there is no delay in cooling the cooling water W1 in the cooling tower 3, preventing the condenser pressure high, Trip of the refrigerator 2 can be avoided.

FIG. 5 is a diagram for explaining a condenser pressure high trip that occurs when the cooling tower control device 4 according to the present embodiment is not used. The solid line in FIG. 5 indicates the cooling water inlet temperature, the dotted line indicates the condenser pressure, the broken line indicates the cooling tower frequency command, the one-dot chain line indicates the cooling tower target temperature, and the two-dot chain line indicates the refrigerator load factor. Yes.
At time t1, the load factor of the refrigerator starts to increase, a new refrigerator is started, and accordingly, the cooling water inlet temperature gradually increases from time t2. Further, since the target temperature of the cooling tower is set to be substantially constant, the fan frequency command for the cooling tower is raised as the cooling water inlet temperature rises in order to lower the increased cooling water inlet temperature. However, even if the fan frequency of the cooling tower is increased after time t2, the cooling water temperature continues to rise, the cooling water cannot be cooled in time, the condenser pressure reaches a predetermined pressure, and a trip occurs at time t3. It has occurred.

As described above, when the load factor of the refrigerator is increased and a new refrigerator is started, the cooling water inlet temperature is increased until the output of the refrigerator is stabilized. However, when the cooling tower control device 4 is not used, Since cooling water cooling is started after the rise in the inlet temperature is detected, cooling water cooling is not in time, and the condenser pressure high trip cannot be prevented.
Therefore, in the cooling tower control device 4 of the present embodiment, when a new refrigerator is started, the cooling water inlet target temperature is lowered for the first predetermined period, thereby setting the fan frequency of the cooling tower to be high and cooling water. Promotes cooling.

FIG. 6 is an example of a diagram showing a time trend (simulation result) of the fan frequency of the cooling tower when the cooling tower control device 4 according to the present embodiment is not used. In FIG. 6, the predetermined value α [° C.] is 4 [° C.], and the cooling water inlet target temperature is the outside wet bulb temperature +4 [° C.].
FIG. 7 is an example of a diagram showing a time trend (simulation result) of the fan frequency of the cooling tower when the cooling tower control device 4 according to the present embodiment is used. In FIG. 7, the predetermined value α [° C.] is set to 4 [° C.], and the first predetermined temperature is set to 2 [° C.], so that the cooling water inlet target temperature is {(outside air wet bulb temperature) +4 [° C.] − 2 [C]} = (outside wet bulb temperature) +2 [C].
6 and 7, the solid line indicates the temperature set value, the broken line indicates the cooling water inlet temperature, the alternate long and short dash line indicates the outside wet bulb temperature, and the alternate long and two short dashes line indicates the fan frequency.

In FIG. 6, since the cooling water temperature rise is delayed with respect to the performance of the refrigerator, the rise of the cooling tower fan frequency is also delayed, and the fan frequency is very unstable.
On the other hand, in FIG. 7, since the cooling water inlet temperature target value is set to a low temperature in advance, the fan rotation speed of the cooling tower increases from an early time. As a result, the fan frequency of the cooling tower was very stable.
By operating the cooling tower with a higher fan frequency in this way, the fan can be operated without a sudden increase when the fan frequency needs to be increased. The instrument will not trip.

[Modification]
In addition, although the refrigeration control apparatus 4 in the above embodiment has been described by taking the example of using the fan frequency for the control of the cooling tower 3, instead of controlling the fan frequency, the number of fans started in the cooling tower 3 is started. May be controlled.
Specifically, the cooling tower control device 4 of the present modification includes the timer 41, the target temperature setting unit 42, the control unit 43, and the storage unit 44 described above, but the first embodiment described above. The main difference from the embodiment is that the control unit 43 sets the number of fans to be started based on the second target temperature acquired from the target temperature setting unit 42.

As described in the first embodiment, the second target temperature as the cooling water inlet target temperature is set to a temperature that is lower than the first target temperature by a first predetermined temperature, and therefore, when the second target temperature is used. The fan startup number X2 is set to be larger than the fan startup number X1 when the first target temperature is used. That is, when the second target temperature is used, the air volume by the fan of the cooling tower 3 increases, and the cooling of the cooling water W1 is promoted.
In this modification, in the case of normal control, the switching unit 42a is connected to the point A, and a fan is used to perform PI control so as to reduce the deviation between the first target temperature and the cooling water inlet temperature T3. This means that the number of activated units is determined.

Processing executed by the cooling tower control device 4 according to this modification will be described with reference to FIG.
It is determined whether or not the external wet bulb temperature detected by the wet bulb thermometers 23a, 23b, and 23c is equal to or higher than a second predetermined temperature (step SB1 in FIG. 8). When it is determined that the external wet bulb temperature is equal to or higher than the second predetermined temperature (Yes in step SB1 in FIG. 8), it is determined whether or not a new refrigerator 2 has been started (step SB2 in FIG. 8). ). When it is determined that the external wet bulb temperature is lower than the second predetermined temperature (No in step SB1 in FIG. 8), the switching unit 42a is connected to the point A for normal control (step SB9 in FIG. 8). Return to SB1.

  When the new refrigerator 2 is not started (No in step SB2 in FIG. 8), the process proceeds to step SB9. When a new refrigerator 2 is activated (Yes in step SB2 in FIG. 8), the cooling tower 3 of the activated number X1 required for normal control according to the wet bulb temperature by the control logic of the heat source system 1 Are activated (step SB3 in FIG. 8). Furthermore, the switching unit 42a is connected to the point B, and cooling of β (= X2−X1) [units] for the shortage number so that the number of fan startups X2 determined based on the second target temperature of the cooling water is reached. The tower 3 is additionally activated (step SB4 in FIG. 8). A second target temperature obtained by subtracting the offset value from the first target temperature is calculated as the cooling water inlet target temperature (step SB5 in FIG. 8).

  The number of fans that start the cooling tower 3 that reduces the deviation between the second target temperature and the cooling water inlet temperature T3 is determined, and the number of fans that start the cooling tower 3 is controlled. Since the second target temperature is lower than the first target temperature, the number of fans activated in the cooling tower 3 is greater when the second target temperature is selected than when the first target temperature is selected. Become. Thus, when the second target temperature is selected, the cooling of the cooling water W1 proceeds more than when the first target temperature is selected. Moreover, since the number of fan activations is increased in advance with the activation of the refrigerator 2, there is no delay in cooling the cooling water W1.

  When the new refrigerator 2 is activated, the timer 41 is activated, and the period after the new refrigerator 2 is activated is measured (step SB6 in FIG. 8). It is determined whether or not the first predetermined period has elapsed since the start of the new refrigerator 2 (step SB7 in FIG. 8). If the first predetermined period has not elapsed (No in step SB7 in FIG. 8), it is determined whether or not a refrigerator trip has occurred (step SB8 in FIG. 8). If a refrigerator trip has occurred (Yes in step SB8 in FIG. 8), the process proceeds to step SB9. If a refrigerator trip has not occurred (No in step SB8 in FIG. 8), the process returns to step SB7. The determination whether or not the first predetermined period has elapsed is repeated.

  On the other hand, if the first predetermined period has elapsed in step SB7 (Yes in step SB7 in FIG. 8), the process proceeds to step SB9, where the switching unit 42a is connected to point A and changed to normal control, and the fan is started. The number is set to the startup number X1, and the process returns to step SB1. Note that the cooling tower step-down process included in the normal control is not performed until the period (start-up mode) from the start of the refrigerator 2 to the first predetermined period is completed.

As described above, according to the present modified example, the number of fan startups corresponding to the second target temperature is set to be larger than the number of fan startups in the case of the first target temperature, thereby reducing the air volume of the cooling tower 3. It is possible to increase the cooling water W1 quickly.
In addition, this modification may be used in place of the setting of the fan frequency of the cooling tower of the first embodiment, or may be used in combination with the setting of the fan frequency of the cooling tower of the first embodiment. May be.
In this modification, when the number of fans started is increased, the number of operating cooling towers may be increased. When a plurality of fans are provided in one cooling tower, one cooling tower is provided. It is also possible to increase the number of fans operating in

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described. The cooling tower control device provided in the present embodiment is different from the first embodiment in that the cooling tower is operated at a frequency where the fan frequency of the cooling tower is higher than a predetermined value. About the heat source system of this embodiment, description is abbreviate | omitted about the point which is common in 1st Embodiment, and a different point is mainly demonstrated using FIG. 1, FIG.

The predetermined value of the cooling tower fan frequency is a predetermined frequency when the cooling water W1 is normally cooled (normally controlled).
As shown in FIG. 9, the cooling water control device 4 according to the present embodiment includes a target temperature setting unit 42 ′.
The target temperature setting unit 42 'has a frequency at which the fan frequency of the cooling tower 3 is higher than the point C for selecting a predetermined frequency when the cooling water W1 is normally cooled and a predetermined frequency when the cooling water W1 is normally controlled. A switching unit 42a ′ having a point D to be selected is provided. In the present embodiment, the normal control means a case where the switching unit 42a is connected to the point C and the fan frequency command value is controlled by PI control. That is, the predetermined frequency when the cooling water W1 of the cooling tower 3 is normally cooled is a control based on a deviation between the target cooling water inlet temperature at the inlet of the refrigerator 2 and the cooling water inlet temperature at the inlet of the refrigerator 2 (for example, , The frequency determined by the PI control in FIG.

For example, the switching unit 42a ′ is connected to the point D until the second predetermined period elapses from the time when the refrigerator 2 is started, and the period measured by the timer 41 is the freezing time. After the second predetermined period has elapsed since the start-up of the machine 2, it is connected to the point C side.
Note that the frequency higher than the predetermined frequency is, for example, a rated frequency, and a frequency stored in advance in the storage unit 44 or the like may be read, or may be appropriately determined by an input device (for example, a keyboard) not illustrated. It may be specified by input.
For example, if the fan frequency command value on the D side of the switching unit 42a ′ is set to the rated frequency, and the switching unit 42a ′ is connected to the D side, the fan frequency of the cooling tower 3 is set to 100 [%. ], And there is no delay due to PI control.

Processing executed by the cooling tower control device 4 according to the present embodiment will be described with reference to FIG.
It is determined whether or not the external wet bulb temperature detected by the wet bulb thermometers 23a, 23b, and 23c is equal to or higher than a second predetermined temperature (step SC1 in FIG. 10). When it is determined that the external wet bulb temperature is lower than the second predetermined temperature (No in step SC1 in FIG. 10), the switching unit 42a ′ is connected to the C side, and the fan frequency of the cooling tower 3 is controlled by PI control. Input (step SC7 in FIG. 10), the process returns to step SC1.
When it is determined that the external wet bulb temperature is equal to or higher than the second predetermined temperature (Yes in step SC1 in FIG. 10), it is determined whether or not a new refrigerator 2 has been started (step in FIG. 10). SC2).

  When the new refrigerator 2 is not activated (No in step SC2 in FIG. 10), the process proceeds to step SC7. When the new refrigerator 2 is activated (Yes in step SC2 in FIG. 10), the switching unit 42a ′ is switched to the D side, and the fan frequency of the cooling tower 3 is set to a frequency higher than a predetermined frequency (for example, a rated frequency). ) And switching to direct input of the fan frequency set on the D side (step SC3 in FIG. 10). Thus, the cooling tower 3 is controlled by a frequency (for example, a rated frequency) that is higher than a predetermined frequency that is used for cooling under normal control. By controlling the fan frequency of the cooling tower 3 at a frequency higher than the predetermined frequency, the air volume increases and the cooling of the cooling water W1 proceeds more than in the case where it is controlled at the predetermined frequency used by the normal control cooling. Further, since the cooling tower 3 is controlled at a high fan frequency in advance with the start of the refrigerator 2, there is no delay in cooling.

Further, when the new refrigerator 2 is activated, the timer 41 is activated, and the period after the new refrigerator 2 is activated is measured (step SC4 in FIG. 10).
It is determined whether or not the second predetermined period has elapsed since the start of the new refrigerator 2 (step SC5 in FIG. 10). If the second predetermined period has not elapsed (No in step SC5 in FIG. 10), it is determined whether a refrigerator trip has occurred (step SC6 in FIG. 10). If a refrigerator trip occurs (Yes in step SC6 in FIG. 10), the process proceeds to step SC7, the switching unit 42a 'is connected to the C side, and the fan frequency of the cooling tower 3 is switched to the input by PI control. Return to SC1. When the refrigerator trip has not occurred (No in step SC6 in FIG. 10), the process returns to step SC5, and the determination as to whether or not the second predetermined period has elapsed is repeated.

  On the other hand, when the second predetermined period has elapsed in step SC5 (Yes in step SC5 in FIG. 10), the process proceeds to step SC7, where the switching unit 42a ′ is connected to the C side and the fan frequency of the cooling tower 3 is set to PI. The input is switched to control, and the process returns to step SC1.

  Thus, according to the cooling tower control device, the cooling tower control method, and the heat source system according to the present embodiment, when the refrigerator 2 is started, the fan frequency command value of the cooling tower 3 can be directly input. Therefore, it is possible to quickly prepare for a rise in the coolant temperature that occurs late.

[Modification]
In the refrigerator control device according to the present embodiment, the description has been given by using the fan frequency for controlling the cooling tower 3 as an example. However, instead of controlling the fan frequency, the fan of the cooling tower 3 is activated. The number of units may be controlled.
Specifically, the cooling tower control device 4 of the present modification includes the timer 41, the target temperature setting unit 42 ′, the control unit 43, and the storage unit 44 of the second embodiment. The main difference from the second embodiment is that the controller 43 starts the cooling unit 3 during the second predetermined period from the time when the refrigerator 2 is started. The point is to set more than the number of fans started.

For example, the switching unit 42a ′ is connected to the point D until the second predetermined period elapses from the time when the refrigerator 2 is started up, and the period measured by the timer 41 is frozen. After the second predetermined period has elapsed since the start-up of the machine 2, the connection is made to the point C side.
The point C side is the number of fans started when the cooling water is cooled by normal control. In this modification, the normal control means a case where the number of fans started is determined and controlled by PI control.
The point D side is a setting for starting more fans than the number of fan startups activated by normal control.

Thus, the cooling capacity of the cooling tower 3 can be easily increased by designating the number of fans to be started by direct input.
The present modification may be used in place of the setting of the fan frequency of the cooling tower of the second embodiment, or may be used in combination with the setting of the fan frequency of the cooling tower of the second embodiment. May be.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described. The cooling tower control device provided in the present embodiment is different from the first embodiment and the second embodiment in that the switching unit 42a or the switching unit 42a ′ is switched based on the temperature change of the cooling water inlet temperature. About the heat source system of this embodiment, description is abbreviate | omitted about the point which is common in 1st Embodiment and 2nd Embodiment, and a different point is mainly demonstrated.

  In the first and second embodiments described above, the switching units 42a and 42a 'are switched based on the elapse of a predetermined period measured by the timer 41 after the refrigerator is started. Thus, if switching part 42a, 42a 'is switched based on progress of the predetermined period by the timer 41, it will switch in cooling water temperature by switching in a shorter time than the refrigerating capacity display of a refrigerator is reflected in cooling water temperature. , And a refrigerator trip may occur due to the high condenser pressure. Or, despite the fact that the refrigeration capacity of the refrigerator is already reflected in the cooling water temperature, it is possible to increase the power consumption by operating the cooling tower at an excessive fan frequency or an excessive number of fan starts. There is a case.

Therefore, in the present embodiment, the trend of the cooling water inlet temperature is monitored, and the switching units 42a and 42a ′ are switched when the temperature change of the cooling water inlet temperature is below a predetermined range.
Specifically, the flag is turned ON when the difference between the chilled water outlet temperature output from the refrigerator and the chilled water outlet target temperature is less than a certain value and a predetermined period or more has elapsed. After that, when the cooling water inlet temperature flowing into the refrigerator from the cooling tower has exceeded a predetermined period, the cooling water inlet temperature target temperature is restored (switching the switching unit 42a to the A side, or switching the switching unit 42a ′ Switch to C side).
This is because the cooling water inlet temperature is stabilized after the cooling water outlet temperature is stabilized, that is, the output of the refrigerator is stabilized before the cooling tower, and the cooling water output is stabilized.

FIG. 11 shows a schematic configuration of the heat source system 1 ′ according to the present embodiment, and description of portions common to FIG. 1 is omitted, and mainly different points will be described.
The evaporator 22 is connected to cold water pipes 51 and 52, and cold water W2 is supplied from the external load 50 via the cold water pipes 51 and 52, and heat is exchanged between the cold water W2 and the refrigerant to evaporate. The cold water W2 cooled by the evaporator 22 is supplied to the external load 50.

The cold water pipe 51 is a pipe through which the cold water W2 flows into the evaporator 22 from the external load 50, and the temperature sensor 15 that measures the temperature of the cold water W2 flowing into the refrigerator 2 (hereinafter referred to as “cold water inlet temperature T1”). Is provided. Information of the cold water inlet temperature T 1 detected by the temperature sensor 15 is output to the cooling tower control device 4.
The cold water pipe 52 is a pipe through which the cold water W2 flows from the evaporator 22 to the external load 50, and the temperature sensor 16 measures the temperature of the cold water W2 flowing out from the refrigerator 2 (hereinafter referred to as “cold water outlet temperature T2”). Is provided. Information on the cold water outlet temperature T2 detected by the temperature sensor 16 is output to the cooling tower control device 4.

  The cooling tower control device 4 includes information on the cold water inlet temperature T1 detected by the temperature sensor 15, information on the cold water outlet temperature T2 detected by the temperature sensor 16, information on the cooling water inlet temperature T3 detected by the temperature sensor 17, And the information on the outside air wet bulb temperature measured by the wet bulb thermometers 23a, 23b, and 23c is acquired.

Below, the operation | movement flow of the refrigerator control apparatus which concerns on this embodiment is demonstrated using FIG. Here, the case where it uses in combination with 1st Embodiment is mentioned as an example.
It is determined whether or not the external wet bulb temperature detected by the wet bulb thermometers 23a, 23b, and 23c is equal to or higher than a second predetermined temperature (step SD1 in FIG. 12). When it is determined that the external wet bulb temperature is lower than the second predetermined temperature (No in step SD1 in FIG. 12), the switching unit 42a is connected to the A side, and the cooling water inlet target temperature is set as the first target temperature (FIG. 12 step SD6), a fan frequency command value is obtained as a controlled variable for PI control of the fan frequency so as to reduce the deviation between the first target temperature and the cooling water inlet temperature T3, and the cooling tower 3 is determined based on the fan frequency command value. And return to step SD1.

  When it is determined that the external wet bulb temperature is equal to or higher than the second predetermined temperature (Yes in step SD1 in FIG. 12), it is determined whether or not a new refrigerator 2 has been started (step in FIG. 12). SD2). When the new refrigerator 2 is not activated (No in step SD2 in FIG. 12), the process proceeds to step SD6. When the new refrigerator 2 is started (Yes in step SD2 in FIG. 12), the switching unit 42a is connected to the B side, and the first target temperature is subtracted from the first target temperature as the cooling water inlet target temperature. 2 Calculate the target temperature (step SD3 in FIG. 12).

  It is determined whether or not the difference between the chilled water outlet temperature T2 detected by the temperature sensor 16 and the chilled water outlet target temperature set as a target for the chilled water outlet temperature is equal to or lower than the third predetermined temperature and the third predetermined period has elapsed. (Step SD4 in FIG. 12). If the third predetermined period has not elapsed, step SD4 is repeated. If the third predetermined period has elapsed, it is determined whether or not the change amount of the cooling water inlet temperature T3 detected by the temperature sensor 17 is equal to or less than the set value and the fourth predetermined period has elapsed (FIG. 12). Step SD5). When the change amount of the cooling water inlet temperature T3 is equal to or less than the set value and the determination as to whether or not the fourth predetermined period has elapsed is No, step SD5 is repeated, and when this determination is Yes, Proceeding to step SD6, the switching unit 42a is connected to the A side, the cooling water inlet target temperature is set to the first target temperature, and the process returns to step SD1.

In addition to the condition of the chilled water outlet temperature T2, regarding the above-mentioned flag ON condition, if the change amount of the chilled water inlet temperature T1 is equal to or less than the fifth predetermined period, the flag ON condition further increases the reliability.
Further, depending on the situation, there is a possibility that the difference between the chilled water outlet temperature T2 and the chilled water outlet target temperature may not be equal to or lower than the third predetermined temperature. May be set, and when the maximum time is exceeded, it may be forcibly returned to the state without offset.

  In addition, although this embodiment was demonstrated as combining with 1st Embodiment, it is not limited to this, You may combine with 2nd Embodiment.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

DESCRIPTION OF SYMBOLS 1, 1 'Heat source system 2 Refrigerator 3a, 3b, 3c Cooling tower 4 Cooling tower control apparatus 10 Cooling water pump 15, 16, 17 Temperature sensor 23a, 23b, 23c Wet bulb thermometer 50 External load W1 Cooling water W2 Cold water

Claims (11)

A cooling tower control device applied to a heat source system including a refrigerator including a condenser that cools a refrigerant with cooling water, and a cooling tower that is connected to the refrigerator and rotates a fan to cool the cooling water. There,
The first target temperature is a target temperature when the cooling water is cooled by normal control,
Wherein the first predetermined time period from the start of the refrigerator, set at the refrigerator first predetermined temperature lower second target temperature than the set cooling water inlet target temperature previously been the first target temperature at the inlet of the second A cooling tower control device that sets a fan frequency of the cooling tower and / or a startup number of fans based on a target temperature.   2. The cooling tower control device according to claim 1, wherein the cooling water inlet target temperature is changed from the second target temperature to the first target temperature after the first predetermined period has elapsed since the start of the refrigerator.   2. The cooling tower control device according to claim 1, wherein when the temperature change of the cooling water inlet temperature at the inlet of the refrigerator is equal to or less than a predetermined range, the cooling water inlet target temperature is set to the first target temperature. A cooling tower control device applied to a heat source system including a refrigerator including a condenser that cools a refrigerant with cooling water, and a cooling tower that is connected to the refrigerator and rotates a fan to cool the cooling water. There,
The fan frequency of the cooling tower is set to a frequency higher than the predetermined frequency when cooling water is normally cooled during the second predetermined period from the start of the refrigerator, and / or The cooling tower control device that sets more than the number of the fans started when the cooling water is normally cooled.   The cooling tower control device according to claim 4, wherein the fan frequency of the cooling tower is changed from a frequency higher than the predetermined frequency to the predetermined frequency after the second predetermined period has elapsed since the start of the refrigerator.   The cooling tower according to claim 4, wherein after the second predetermined period has elapsed since the start of the refrigerator, the number of fans started in the cooling tower is changed to the number of fans started when the cooling water is normally cooled. Control device.   The said fan frequency of the said cooling tower is set to the said predetermined frequency from the frequency higher than the said predetermined frequency when the temperature change of the cooling water inlet temperature in the said refrigerator inlet is below a predetermined range. Cooling tower control device.   5. When the temperature change of the cooling water inlet temperature at the inlet of the refrigerator is below a predetermined range, the number of fans started in the cooling tower is changed to the number of fans started when the cooling water is normally cooled. The cooling tower control device described in 1. A refrigerator,
A cooling tower connected to the refrigerator;
A heat source system comprising the cooling tower control device according to any one of claims 1 to 8. A cooling tower control method applied to a heat source system including a refrigerator having a condenser that cools a refrigerant with cooling water, and a cooling tower that is connected to the refrigerator and rotates a fan to cool the cooling water. There,
The first target temperature is a target temperature when the cooling water is cooled by normal control,
Wherein the first predetermined time period from the start of the refrigerator, set at the refrigerator first predetermined temperature lower second target temperature than the set cooling water inlet target temperature previously been the first target temperature at the inlet of the second The cooling tower control method which sets the fan frequency of the said cooling tower and / or the starting number of fans based on target temperature. A cooling tower control method applied to a heat source system including a refrigerator having a condenser that cools a refrigerant with cooling water, and a cooling tower that is connected to the refrigerator and rotates a fan to cool the cooling water. There,
The fan frequency of the cooling tower is set to a frequency higher than the predetermined frequency when cooling water is normally cooled during the second predetermined period from the start of the refrigerator, and / or The cooling tower control method which sets more than the starting number of the said fans when cooling water is normally cooled.

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