JP5336882B2 - Cooling tower fan control apparatus and method - Google Patents

Description

  The present invention relates to a cooling tower fan control apparatus and method for controlling the operation of a cooling tower fan that supplies cooling water to an absorption refrigerator.

  Conventionally, in air conditioning control in a facility such as a building, an absorption refrigerator is used as a device for obtaining cold water for cooling. The absorption refrigerator is well known as a refrigerator that obtains cold water by absorbing refrigerant vapor in an absorbing liquid. For this absorption chiller, cooling water is supplied from a cooling tower, and waste heat in the absorption chiller is placed on the cooling water, returned to the cooling tower, and released to the outside air (for example, Patent Documents). 1).

  FIG. 7 shows a main part of an air conditioning control system in which cooling water is supplied from a cooling tower to an absorption refrigerator. In the figure, 1 is an absorption refrigerator, 2 is a cooling tower, and cooling water from the cooling tower 2 is supplied to the absorption refrigerator 1 via a cooling water forward pipe 3 and via a cooling water return pipe 4. Then, the absorption refrigerator 1 returns to the cooling tower 2. The cooling water outgoing pipe 3 is provided with a cooling water pump 5 for circulating cooling water from the cooling tower 2 to the absorption refrigerator 1.

  In the absorption refrigerator 1, water is used as a refrigerant, and lithium bromide is used as an absorbing solution. Also, as its basic cycle, the refrigerant is evaporated by a low-temperature and low-pressure evaporator to produce cold water, the evaporated refrigerant is absorbed by the absorbing liquid by the absorber, and the absorbing liquid that has absorbed the refrigerant is sent to the regenerator, where the absorbing liquid is Heat is applied to the refrigerant to evaporate and separate the refrigerant, and the absorption liquid obtained by evaporating and separating the refrigerant is returned to the absorber.On the other hand, the refrigerant evaporatively separated from the absorption liquid is cooled by a condenser and liquefied. Repeat the action of using.

  During operation of the absorption chiller 1, the cooling water pump 5 is turned on to circulate the cooling water from the cooling tower 2, and the fan (cooling tower fan) 2-1 of the cooling tower 2 is rotated to produce cooling water. The waste heat that has been put back is released to the outside air. In this air conditioning control system, the operation of the cooling tower fan 2-1 is controlled by the cooling tower fan control device 6. Note that an inverter is attached to the cooling tower fan 2-1, and the rotational speed of the cooling tower fan 2-1 is adjusted by sending a command to the inverter.

(Control of cooling tower fan during operation of absorption refrigerator)
When the start of operation is instructed, the absorption refrigerator 1 turns on the cooling water pump 5 and sends an operation start command for the cooling tower fan to the cooling tower fan control device 6. The cooling tower fan control device 6 receives the operation start command from the absorption refrigerator 1 and starts the operation of the cooling tower fan 2-1.

  In this case, the cooling tower fan control device 6 takes in the temperature of the cooling water from the cooling tower 2 to the absorption refrigerator 1 as the cooling tower outlet temperature TCpv through the temperature sensor 7, and uses this cooling tower outlet temperature TCpv as the cooling tower The rotational speed of the cooling tower fan 2-1 is controlled so that the outlet temperature set value TCsp is set (TCpv = TCsp).

  In this example, only one cooling tower 2 is shown, but a plurality of cooling towers 2 may be provided. In such a case, not only the number of rotations of the cooling tower fan 2-1 but also the number of operating cooling tower fans 2-1 is controlled. When the cooling tower fan 2-1 is not provided with an inverter for controlling the rotation speed, the cooling tower fan 2-1 is controlled to be turned on / off, or the cooling tower fan 2-1 is operated. By controlling the number, the cooling tower outlet temperature TCpv is made to coincide with the cooling tower outlet temperature set value TCsp.

  The cooling tower outlet temperature set value TCsp is set to, for example, 20 to 22 ° C. for the purpose of improving the operation efficiency of the absorption chiller 1. The cooling tower outlet temperature set value TCsp is almost always a fixed value, but an upper limit value and a lower limit value are determined and may be adjusted within the range.

[When absorption chiller is shut down]
When an instruction to stop the operation is given, the absorption refrigerator 1 sends an operation stop command to the cooling pump 5 and the cooling tower fan control device 6 after a predetermined time T has elapsed. Thereby, the absorption refrigerator 1 stops the operation of the basic cycle described above when the stop of the operation is instructed. Hereinafter, the stop of the operation of the basic cycle is also referred to as the stop of the operation of the absorption refrigerator 1.

  After the operation of the absorption refrigerator 1 is stopped, the cooling pump 5 and the cooling tower fan 2-1 are continuously operated until a predetermined time T elapses. That is, the cooling pump 5 continues to be on, and the cooling tower fan control device 6 continues to control the rotation speed of the cooling tower fan 2-1 using the cooling tower outlet temperature set value TCsp.

  In the absorption refrigerator, when the operation of the basic cycle is stopped, the high-concentration absorption liquid produced by the regenerator may become crystals and adhere due to a decrease in the internal temperature after the stop. In order to prevent this, at the same time as the operation of the absorption refrigerator is stopped, the refrigerant (water) on the evaporator side is sent to the absorber side to reduce the concentration of the absorbing liquid. This is called dilution operation. During the dilution operation, it is necessary to continue supplying the cooling water from the cooling tower to the absorption refrigerator.

  For this reason, in the above-described air conditioning control system, the cooling pump 5 and the cooling tower fan 2- are kept until the predetermined time T elapses after the operation of the absorption refrigerator 1 is stopped (until the dilution operation ends). 1 is continued, and cooling water is supplied to the absorption refrigerator 1.

JP 2000-337729 A

  During the operation of the absorption refrigeration machine 1, that is, during the normal operation in which the absorption refrigeration machine 1 continues the operation of the basic cycle, in order to improve the operation efficiency of the absorption refrigeration machine 1, it is supplied from the cooling tower 2 It is desirable that the cooling water used has a low value. On the other hand, since the operation of the basic cycle is stopped during the dilution operation when the absorption chiller 1 is stopped, there is no need to aim at improving the operation efficiency of the absorption chiller 1. The temperature of the cooling water may be high.

  However, conventionally, during the dilution operation when the absorption chiller 1 is stopped, the cooling tower outlet temperature TCpv is set so that the cooling tower outlet temperature setting value TCsp is the same as that during the normal operation of the absorption chiller 1. Therefore, power consumption in the cooling tower fan 2-1 increases.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a cooling tower fan control device that can save energy during a dilution operation when the absorption refrigerator is stopped, and It is to provide a method.

  In order to achieve such an object, the present invention provides an absorption refrigerator that absorbs refrigerant vapor into an absorption liquid to obtain cold water, a cooling tower that supplies cooling water to the absorption refrigerator, and the cooling tower A cooling water pump that circulates cooling water from the chiller to the absorption chiller and dilutes the concentration of the absorption liquid in the absorption chiller while the cooling water pump continues to operate when the absorption chiller is stopped. Is a cooling system that controls the operation of the cooling tower fan so that the temperature of the cooling water from the cooling tower to the absorption refrigerator is set to the cooling tower outlet temperature set value determined for the cooling water. In the tower fan control device, a dilution operation determining means for determining whether or not the dilution operation has been started, and a cooling tower that changes the cooling tower outlet temperature set value to a higher value when it is determined that the dilution operation has been started. Outlet temperature set value It is provided with a a further means. Note that the present invention can be realized not as a cooling tower fan control device but as a cooling tower fan control method.

According to this invention, when the operation of the absorption refrigerator is stopped and the dilution operation is started, the cooling tower outlet temperature set value is changed to a higher value than before. That is, in the diluted operation upon stopping of the absorption refrigerating machine, rather than the same cooling tower outlet temperature set value during normal operation of the absorption type refrigerator, the cooling tower outlet temperature is changed to a value higher than that A set value is used. Thereby, for example, if the number of rotations of the cooling tower fan is controlled, the number of rotations of the cooling tower fan is reduced and the power consumption is reduced. In addition, if the on / off of the cooling tower fan is controlled, the cooling tower fan off period is increased, and the power consumption is reduced. In addition, if the number of operating cooling tower fans is controlled, the number of operating cooling tower fans is reduced, and power consumption is reduced.

  In the present invention, when it is determined that the dilution operation has been started, the cooling tower outlet temperature setting value is changed to a higher value than before, but the predetermined value is set as the changed cooling tower outlet temperature setting value (TCup). Alternatively, a predetermined temperature range (ΔTup) determined in advance may be added to the cooling tower outlet temperature setting value (TCsp) so far to obtain a changed cooling tower outlet temperature setting value (TCup = TCsp + ΔTup). In addition, the changed cooling tower outlet temperature setting value (TCup = TCsp + ΔTup) is compared with a predetermined upper limit value (TCmax), and when the changed cooling tower outlet temperature setting value exceeds the upper limit value, You may make it make it the cooling tower exit temperature setting value (TCup = TCmax) after changing a value.

  In the present invention, the operation state of the absorption chiller and the cooling water pump is monitored, and when the operation of the absorption chiller is stopped and the cooling water pump is operating, it is determined that the dilution operation is being performed. Also good. In this case, when it is confirmed that the operation of the absorption refrigerator is stopped and the cooling water pump is confirmed to be operating, it is determined that the dilution operation has been started. Note that only the operation state of the absorption chiller may be monitored, and it may be determined that the dilution operation has been started when the operation of the absorption chiller is stopped.

  According to the present invention, it is determined whether or not the dilution operation has been started. When it is determined that the dilution operation has been started, the cooling tower outlet temperature setting value is changed to a higher value than before. During operation, the outlet temperature of the cooling tower is made higher than during normal operation, so that power consumption by the cooling tower fan can be reduced and energy can be saved.

It is a figure which shows the principal part of one Embodiment (Embodiment 1) of the air-conditioning control system to which the cooling tower fan control apparatus which concerns on this invention was attached. 6 is a flowchart for explaining an operation of changing the cooling tower outlet temperature set value during the dilution operation in the cooling tower fan control device in the first embodiment. 3 is a functional block diagram of a main part of the cooling tower fan control device in Embodiment 1. FIG. It is a figure which shows the principal part of other embodiment (Embodiment 2) of the air-conditioning control system to which the cooling tower fan control apparatus which concerns on this invention was attached. 6 is a flowchart for explaining a changing operation of a cooling tower outlet temperature set value during a dilution operation in the cooling tower fan control device in the second embodiment. 6 is a functional block diagram of a main part of a cooling tower fan control device in Embodiment 2. FIG. It is a figure which shows the principal part of the air-conditioning control system to which the conventional cooling tower fan control apparatus was attached.

Hereinafter, the present invention will be described in detail with reference to the drawings.
[Embodiment 1]
FIG. 1 is a diagram showing a main part of an embodiment of an air conditioning control system provided with a cooling tower fan control device according to the present invention. In this figure, the same reference numerals as those in FIG. 7 denote the same or equivalent components as those described with reference to FIG.

  In this air conditioning control system, the cooling tower fan control device that controls the operation of the cooling tower fan 2-1 is denoted by reference numeral 8 to be distinguished from the conventional cooling tower fan control device 6 shown in FIG. .

  In this embodiment, the cooling tower fan control device 8 is realized by hardware including a processor and a memory, and a program for realizing various functions as a control device in cooperation with these hardware. A cooling tower fan speed control function is provided as a form-specific function.

  In this embodiment, the memory of the cooling tower fan control device 8 has a cooling tower outlet temperature setting value (hereinafter referred to as a first cooling tower outlet temperature setting value) used during normal operation of the absorption chiller 1. TCsp and a cooling tower outlet temperature setting value (hereinafter referred to as a second cooling tower outlet temperature setting value) TCup used during the dilution operation when the absorption refrigerator 1 is stopped is stored. .

  In this embodiment, the first cooling tower outlet temperature set value TCsp is 20 ° C. The second cooling tower outlet temperature set value TCup is determined as a value higher than the first cooling tower outlet temperature set value TCsp. In this example, the second cooling tower outlet temperature set value TCup is set to 32 ° C.

(Control of cooling tower fan during operation of absorption refrigerator)
When the start of operation is instructed, the absorption refrigerator 1 turns on the cooling water pump 5 and sends an operation start command for the cooling tower fan to the cooling tower fan control device 8. The cooling tower fan control device 8 receives the operation start command from the absorption refrigerator 1 and starts the operation of the cooling tower fan 2-1.

  In this case, the cooling tower fan control device 8 takes in the temperature of the cooling water from the cooling tower 2 to the absorption refrigerator 1 as the cooling water outlet temperature TCpv through the temperature sensor 7, and uses this cooling tower outlet temperature TCpv as the first temperature. The number of revolutions of the cooling tower fan 2-1 is controlled so that the cooling tower outlet temperature set value TCsp (20 ° C.) is 1 (TCpv = TCsp).

  The cooling tower fan control device 8 monitors the operating states of the absorption chiller 1 and the cooling water pump 5 during the control of the rotation speed of the cooling tower fan 2-1. Here, if the absorption refrigerator 1 is in operation (FIG. 2: NO in step S101), the cooling tower fan 2-1 using the first cooling tower outlet temperature set value TCsp (20 ° C.) is used. The control of the rotational speed is continued (step S102).

[When absorption chiller is shut down]
When the absorption chiller 1 is instructed to stop its operation, the absorption refrigerator 1 stops its operation, that is, the operation of the basic cycle. The cooling tower fan control device 8 monitors the operation state of the absorption chiller 1 and the cooling water pump 5, confirms that the operation of the absorption chiller 1 is stopped (YES in step S101), and the cooling water pump. When it is confirmed that 5 is in operation (YES in step S103), it is determined that the dilution operation is started (step S104).

  When it is determined that the cooling tower fan control device 8 has entered the dilution operation, the first cooling tower outlet temperature setting value TCsp (20 ° C.) that has been used is changed to the second cooling tower outlet temperature setting value TCup (32 ° C.). ) And the rotational speed of the cooling tower fan 2-1 is controlled using the changed second cooling tower outlet temperature set value TCup (32 ° C.) (step S105).

  When the predetermined time T elapses after the absorption chiller 1 is stopped, the absorption chiller turns off the cooling water pump 5 and sends a cooling tower fan operation stop command to the cooling tower fan control device 8. Thereby, both the operation of the cooling water pump 5 and the cooling tower fan 2-1 are stopped.

  In the first embodiment, during the dilution operation when the absorption chiller 1 is stopped, the cooling tower outlet temperature setting value TCsp (20 ° C.) is not the same as that during the normal operation of the absorption chiller 1, but Also, the cooling tower outlet temperature set value TCup (32 ° C.) changed to a higher value is used. Thereby, the rotation speed of the cooling tower fan 2-1 decreases, power consumption is reduced, and energy saving during the dilution operation is achieved.

  FIG. 3 shows a functional block diagram of a main part of the cooling tower fan control device 8 according to the first embodiment. The cooling tower fan control device 8 includes a refrigerator operation monitoring unit 8A1 that monitors the operation state of the absorption chiller 1, a cooling water pump operation monitoring unit 8A2 that monitors the operation state of the cooling water pump 5, and a first cooling. Tower outlet temperature setting value (cooling tower outlet temperature setting value used during normal operation) TCsp, first cooling tower outlet temperature setting value storage unit 8A3, and second cooling tower outlet temperature setting value (dilution operation) Cooling tower outlet temperature setting value used in the second cooling tower outlet temperature setting value storage unit 8A4 for storing TCup, dilution operation determination unit 8A5, cooling tower outlet temperature setting value change unit 8A6, cooling tower fan And a control unit 8A7.

  The dilution operation determination unit 8A5 receives the monitoring state from the refrigerator operation monitoring unit 8A1 and the cooling water pump operation monitoring unit 8A2, and confirms that the operation of the absorption refrigerator 1 is stopped, and the cooling water pump 5 is operating. When it is confirmed that the dilution operation is started, a change command for the cooling tower outlet temperature setting value is sent to the cooling tower outlet temperature setting value changing unit 8A6.

  When the cooling tower outlet temperature setting value change command is sent from the dilution operation determining unit 8A5, the cooling tower outlet temperature setting value changing unit 8A6 outputs the first cooling to the cooling tower fan control unit 8A7 until then. Instead of the tower outlet temperature setting value TCsp, the second cooling tower outlet temperature setting value TCup stored in the second cooling tower outlet temperature setting value storage unit 8A3 is output to the cooling tower fan control unit 8A7.

  When the second cooling tower outlet temperature setting value TCup is sent from the cooling tower outlet temperature setting value changing part 8A6, the cooling tower fan control unit 8A7 sets the cooling tower outlet temperature TCpv to the second cooling tower outlet temperature setting value. The number of revolutions of the cooling tower fan 2-1 is controlled so as to be TCup (TCpv = TCup).

[Embodiment 2]
In the first embodiment, the cooling tower outlet temperature set value TCsp used during normal operation is set as a fixed value, but an upper limit value and a lower limit value may be determined and adjusted within the range. In the second embodiment, for example, the upper limit value TCmax is set to 32 ° C., the lower limit value TCmin is set to 20 ° C., and the cooling tower outlet temperature set value TCsp used during normal operation between the upper limit value TCmax and the lower limit value TCmin. Can be adjusted.

  In this case, as shown in FIG. 4, the upper limit value TCmax and the lower limit value TCmin are stored in the memory of the cooling tower fan control device 8, and the values are within the range between the upper limit value TCmax and the lower limit value TCmin. The adjusted cooling tower outlet temperature setting value (first cooling tower outlet temperature setting value) TCsp is stored in a memory and used. The memory of the cooling tower fan control device 8 stores a predetermined temperature range ΔTup for determining the cooling tower outlet temperature setting value (second cooling tower outlet temperature setting value) TCup used during the dilution operation. Keep it. In this example, the predetermined temperature width ΔTup is set to 5 ° C.

(Control of cooling tower fan during operation of absorption refrigerator)
When the start of operation is instructed, the absorption refrigerator 1 turns on the cooling water pump 5 and sends an operation start command for the cooling tower fan to the cooling tower fan control device 8. The cooling tower fan control device 8 receives the operation start command from the absorption refrigerator 1 and starts the operation of the cooling tower fan 2-1.

  In this case, the cooling tower fan control device 8 takes in the temperature of the cooling water from the cooling tower 2 to the absorption refrigerator 1 as the cooling water outlet temperature TCpv through the temperature sensor 7, and uses this cooling tower outlet temperature TCpv as the first temperature. The number of revolutions of the cooling tower fan 2-1 is controlled so that the cooling tower outlet temperature set value TCsp is 1 (TCpv = TCsp).

  Note that the first cooling tower outlet temperature set value TCsp is adjusted as a value within the range between the upper limit value TCmax and the lower limit value TCmin, as described above, and stored in the memory. Hereinafter, for the sake of explanation, it is assumed that the first cooling tower outlet temperature set value TCsp is adjusted to 20 ° C.

  The cooling tower fan control device 8 monitors the operating states of the absorption chiller 1 and the cooling water pump 5 during the control of the rotation speed of the cooling tower fan 2-1. Here, if the absorption refrigeration machine 1 is in operation (FIG. 5: NO in step S201), the cooling tower fan 2-1 using the first cooling tower outlet temperature set value TCsp (20 ° C.) is used. Control of the rotational speed is continued (step S202).

[When absorption chiller is shut down]
When the absorption chiller 1 is instructed to stop its operation, the absorption refrigerator 1 stops its operation, that is, the operation of the basic cycle. The cooling tower fan control device 8 monitors the operation state of the absorption chiller 1 and the cooling water pump 5, confirms that the operation of the absorption chiller 1 is stopped (YES in step S201), and the cooling water pump. If it is confirmed that 5 is in operation (YES in step S203), it is determined that the dilution operation has been started (step S204).

  When the cooling tower fan control device 8 determines that the dilution operation has been started, the cooling tower fan control device 8 adds a predetermined temperature range ΔTup (5 ° C.) to the first cooling tower outlet temperature setting value TCsp (20 ° C.) used so far. A second cooling tower outlet temperature set value TCup (25 ° C.) is obtained (step S205).

  Then, the obtained second cooling tower outlet temperature set value TCup (25 ° C.) is compared with the upper limit value TCmax (32 ° C.) (step S206). If TCup ≦ TCmax (NO in step S206), step S208 is performed. If TCup> TCmax (YES in step S206), the process proceeds to step S208 via step 207.

  In this example, TCup is 25 ° C. and TCmax is 32 ° C. Since it is determined in step S206 that TCup ≦ TCmax, the process immediately proceeds to step S208. In step S208, the cooling tower fan control device 8 changes the first cooling tower outlet temperature setting value TCsp (20 ° C.) used so far to the second cooling tower outlet temperature setting value TCup (25 ° C.). Then, the rotation number of the cooling tower fan 2-1 is controlled using the changed second cooling tower outlet temperature set value TCup (25 ° C.).

  When the predetermined time T elapses after the absorption chiller 1 is stopped, the absorption chiller turns off the cooling water pump 5 and sends a cooling tower fan operation stop command to the cooling tower fan control device 8. Thereby, both the operation of the cooling water pump 5 and the cooling tower fan 2-1 are stopped.

  In the second embodiment, during the dilution operation when the absorption chiller 1 is stopped, the cooling tower outlet temperature set value TCsp is not the same as that during the normal operation of the absorption chiller 1, but a predetermined temperature is set. A cooling tower outlet temperature set value TCup that is changed to a value higher by the width ΔTup is used. Thereby, the rotation speed of the cooling tower fan 2-1 decreases, power consumption is reduced, and energy saving during the dilution operation is achieved.

  In the above description, the first cooling tower outlet temperature set value TCsp is set to 20 ° C. However, when the first cooling tower outlet temperature set value TCsp is, for example, 28 ° C., the second value obtained in step S205 is used. The cooling tower outlet temperature set value TCup is 33 ° C. In this case, since it is determined in step S206 that TCup> TCmax, the process proceeds to step S208 via step 207.

  In step S207, the second cooling tower outlet temperature set value TCup is replaced with the upper limit value TCmax. That is, the second cooling tower outlet temperature set value TCup is replaced with 33 ° C. calculated in step S205 by 32 ° C. which is the upper limit value TCmax.

  Thereby, in step S208, the cooling tower fan control device 8 uses the first cooling tower outlet temperature setting value TCsp (28 ° C.) used so far as the second cooling tower outlet temperature setting value TCup (32 ° C.). The number of revolutions of the cooling tower fan 2-1 is controlled using the changed second cooling tower outlet temperature set value TCup (32 ° C.).

  Thus, in the second embodiment, when the changed cooling tower outlet temperature set value TCup exceeds the upper limit value TCmax, the upper limit value TCmax is set to the changed cooling tower outlet temperature set value TCup, that is, the upper limit. Since the cooling tower outlet temperature setting value TCup is regulated by the value TCmax, the temperature of the cooling water to the absorption chiller 1 during the dilution operation is prevented from becoming too high.

  FIG. 6 shows a functional block diagram of the main part of the cooling tower fan control device 8 according to the second embodiment. The cooling tower fan control device 8 includes a refrigerator operation monitoring unit 8B1 that monitors the operation state of the absorption chiller 1, a cooling water pump operation monitoring unit 8B2 that monitors the operation state of the cooling water pump 5, and an upper limit value TCmax. Upper limit value storage unit 8B3 for storing, lower limit value storage unit 8B4 for storing lower limit value TCmin, and first cooling tower outlet temperature setting value adjusted as a value within a range between upper limit value TCmax and lower limit value TCmin (Cooling tower outlet temperature setting value used during normal operation) First cooling tower outlet temperature setting value storage unit 8B5 that stores TCsp, temperature width storage unit 8B6 that stores a predetermined temperature width ΔTup, and dilution operation Judgment unit 8B7, second cooling tower outlet temperature setting value (cooling tower outlet temperature setting value used during dilution operation) TCup, second cooling tower outlet temperature setting value calculation part 8B8, and cooling tower outlet temperature A setting value changing portion 8B9, and a cooling tower fan control unit 8B10.

  The dilution operation determination unit 8B7 receives the monitoring state from the refrigerator operation monitoring unit 8B1 and the cooling water pump operation monitoring unit 8B2, and confirms that the operation of the absorption refrigerator 1 is stopped and the cooling water pump 5 is operating. When it is confirmed that the dilution operation is started, a change instruction for the cooling tower outlet temperature setting value is sent to the second cooling tower outlet temperature setting value calculation unit 8B8.

  The second cooling tower outlet temperature set value calculation unit 8B8 stores the first cooling tower outlet temperature set value storage unit 8B5 when a command to change the cooling tower outlet temperature set value is sent from the dilution operation determination unit 8B5. The first cooling tower outlet temperature setting value TCsp is read, the temperature width ΔTup stored in the temperature width storage unit 8B6 is read, and the temperature width ΔTup is added to the first cooling tower outlet temperature setting value TCsp. Then, the second cooling tower outlet temperature setting value TCup is obtained, and a cooling tower outlet temperature setting value change command to which the second cooling tower outlet temperature setting value TCup is added is sent to the cooling tower outlet temperature setting value changing unit 8B9.

  When the cooling tower outlet temperature setting value change command is transferred from the second cooling tower outlet temperature setting value calculation unit 8B8, the cooling tower outlet temperature setting value changing unit 8B9 outputs to the cooling tower fan control unit 8B10 until then. Instead of the first cooling tower outlet temperature setting value TCsp, the second cooling tower added to the cooling tower outlet temperature setting value change command from the second cooling tower outlet temperature setting value calculation unit 8B8 The outlet temperature set value TCup is output to the cooling tower fan control unit 8B10.

  When the second cooling tower outlet temperature setting value TCup is sent from the cooling tower outlet temperature setting value changing part 8B9, the cooling tower fan control unit 8B10 sets the cooling tower outlet temperature TCpv to the second cooling tower outlet temperature setting value. The number of revolutions of the cooling tower fan 2-1 is controlled so as to be TCup (TCpv = TCup).

  In the first and second embodiments described above, the rotational speed of the cooling tower fan 2-1 is controlled. However, on / off of the cooling tower fan 2-1 may be controlled. When controlling on / off of the cooling tower fan 2-1, during the dilution operation, the off period of the cooling tower fan 2-1 is increased, power consumption is reduced, and energy saving is achieved.

  In the first and second embodiments described above, only one cooling tower 2 is shown. However, when a plurality of cooling towers 2 are provided, only the number of rotations of the cooling tower fan 2-1 is used. Instead, the number of operating cooling tower fans 2-1 may be controlled. In this case, during the dilution operation, the number of operating cooling tower fans 2-1 is reduced, power consumption is reduced, and energy saving is achieved.

  Further, in the first and second embodiments described above, the operating states of the absorption chiller 1 and the cooling water pump 5 are monitored, the stoppage of the operation of the absorption chiller 1 is confirmed, and the cooling water pump 5 is in operation. When it is confirmed that the dilution operation is started, only the operation state of the absorption chiller 1 is monitored, and when the operation of the absorption chiller 1 is confirmed to be stopped. It may be determined that the dilution operation has been started.

  In Embodiments 1 and 2 described above, during the dilution operation when the absorption chiller 1 is stopped, the cooling tower outlet temperature set value TCsp during normal operation of the absorption chiller 1 is set to a higher value. Although the changed cooling tower outlet temperature setting value TCup is used, the operation of the cooling tower fan 2-1 may be stopped without changing the cooling tower outlet temperature setting value.

  When the operation of the cooling tower fan 2-1 is stopped, an operation state signal indicating that the operation of the absorption chiller 1 is stopped is directly sent from the absorption refrigeration machine 1 to the cooling tower fan 2-1. The operation of the fan 2-1 may be stopped.

  The cooling tower fan control device and method of the present invention is used for an air conditioning control system in various facilities such as buildings as a device and method for controlling the operation of a cooling tower fan that supplies cooling water to an absorption chiller. Is possible.

  DESCRIPTION OF SYMBOLS 1 ... Absorption type refrigerator, 2 ... Cooling tower, 2-1 ... Cooling tower fan, 3 ... Cooling water outgoing pipe, 4 ... Cooling water return pipe, 5 ... Cooling water pump, 7 ... Temperature sensor, 8 ... Cooling tower fan Control device, 8A ... refrigerator operation monitoring unit, 8A2 ... cooling water pump operation monitoring unit, 8A3 ... first cooling tower outlet temperature set value storage unit, 8A4 ... second cooling tower outlet temperature set value storage unit, 8A5 ... Dilution operation determination unit, 8A6 ... cooling tower outlet temperature set value changing unit, 8A7 ... cooling tower fan control unit, 8B1 ... refrigerator operation monitoring unit, 8B2 ... cooling water pump operation monitoring unit, 8B3 ... upper limit value storage unit, 8B4 ... Lower limit value storage unit, 8B5 ... first cooling tower outlet temperature set value storage unit, 8B6 ... temperature range storage unit, 8B7 ... dilution operation determination unit, 8B8 ... second cooling tower outlet temperature set value calculation unit, 8B8 ... cooling Tower outlet temperature set value change unit, 8B10 ... Cooling tower fan control .

Claims (10)

An absorption chiller that absorbs refrigerant vapor into the absorption liquid to obtain cold water, a cooling tower that supplies cooling water to the absorption chiller, and circulating cooling water from the cooling tower to the absorption chiller A cooling water pump, and attached to a system for performing a dilution operation for reducing the concentration of the absorption liquid in the absorption chiller while continuing the operation of the cooling water pump when the absorption chiller is stopped. In the cooling tower fan control device for controlling the operation of the cooling tower fan so that the temperature of the cooling water from the tower to the absorption refrigerator is a cooling tower outlet temperature set value determined for the cooling water,
Dilution operation judging means for judging whether or not the dilution operation has been started;
A cooling tower fan control device comprising: cooling tower outlet temperature setting value changing means for changing the cooling tower outlet temperature setting value to a higher value than before when it is determined that the dilution operation has been started. In the cooling tower fan control device according to claim 1,
The cooling tower outlet temperature set value changing means is
When it is determined that the dilution operation has been started, the cooling tower outlet temperature setting value after changing is obtained by adding a predetermined temperature range to the cooling tower outlet temperature setting value up to that point. Cooling tower fan control device. In the cooling tower fan control device according to claim 2,
The cooling tower outlet temperature set value changing means is
The cooling tower outlet temperature setting value after the change is compared with a predetermined upper limit value, and if the cooling tower outlet temperature setting value after the change exceeds the upper limit value, the cooling tower outlet after the change of the upper limit value A cooling tower fan control device characterized by having a temperature set value. In the cooling tower fan control device according to any one of claims 1 to 3,
The dilution operation determination means includes
The cooling tower fan control device characterized in that when the operation of the absorption chiller is stopped and the cooling water pump is in operation, it is determined that the dilution operation is being performed. An absorption chiller that absorbs refrigerant vapor into the absorption liquid to obtain cold water, a cooling tower that supplies cooling water to the absorption chiller, and circulating cooling water from the cooling tower to the absorption chiller A cooling water pump, applied to a system for performing a dilution operation for reducing the concentration of the absorbing liquid in the absorption chiller while continuing the operation of the cooling water pump when the absorption chiller is stopped. In the cooling tower fan control method for controlling the operation of the cooling tower fan so that the temperature of the cooling water from the tower to the absorption refrigerator is a cooling tower outlet temperature set value determined for the cooling water,
A dilution operation determining step for determining whether or not the dilution operation has been entered, and a cooling tower outlet temperature setting value for changing the cooling tower outlet temperature setting value to a higher value than before when it is determined that the dilution operation has been entered A cooling tower fan control method comprising: a changing step. In the cooling tower fan control method according to claim 5,
The cooling tower outlet temperature setting value changing step includes:
When it is determined that the dilution operation has been started, the cooling tower outlet temperature setting value after changing is obtained by adding a predetermined temperature range to the cooling tower outlet temperature setting value up to that point. Cooling tower fan control method. In the cooling tower fan control method according to claim 6,
The cooling tower outlet temperature setting value changing step includes:
The cooling tower outlet temperature setting value after the change is compared with a predetermined upper limit value, and if the cooling tower outlet temperature setting value after the change exceeds the upper limit value, the cooling tower outlet after the change of the upper limit value A cooling tower fan control method, characterized in that the temperature set value is used. In the cooling tower fan control method according to any one of claims 5 to 7,
The dilution operation determining step includes:
A cooling tower fan control method characterized in that when the operation of the absorption chiller is stopped and the cooling water pump is operating, it is determined that the dilution operation is being performed. An absorption chiller that absorbs refrigerant vapor into the absorption liquid to obtain cold water, a cooling tower that supplies cooling water to the absorption chiller, and circulating cooling water from the cooling tower to the absorption chiller A cooling water pump, and attached to a system for performing a dilution operation for reducing the concentration of the absorption liquid in the absorption chiller while continuing the operation of the cooling water pump when the absorption chiller is stopped. In the cooling tower fan control device for controlling the operation of the cooling tower fan so that the temperature of the cooling water from the tower to the absorption refrigerator is a cooling tower outlet temperature set value determined for the cooling water,
A cooling tower fan control device comprising cooling tower fan stopping means for stopping the operation of the cooling tower fan when entering the dilution operation. An absorption chiller that absorbs refrigerant vapor into the absorption liquid to obtain cold water, a cooling tower that supplies cooling water to the absorption chiller, and circulating cooling water from the cooling tower to the absorption chiller A cooling water pump, applied to a system for performing a dilution operation for reducing the concentration of the absorbing liquid in the absorption chiller while continuing the operation of the cooling water pump when the absorption chiller is stopped. In the cooling tower fan control method for controlling the operation of the cooling tower fan so that the temperature of the cooling water from the tower to the absorption refrigerator is a cooling tower outlet temperature set value determined for the cooling water,
A cooling tower fan control method comprising: a cooling tower fan stop step for stopping the operation of the cooling tower fan when the dilution operation is started.

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