Control device for water cooling cycle for air conditioning and control method therefor

Abstract

To provide a control device for a water cooling cycle for air conditioning capable of efficiently attaining energy saving in simple configuration, and a control method therefor.SOLUTION: A control device for a water cooling system A for air conditioning comprises: load acquisition means for acquiring loads of heat sources 1, 1...; outbound cooling water passage flow rate control means for comparing a value of the load of each heat source acquired by the load acquisition means with a preset threshold and controlling a flow rate of cooling water flowing from the heat sources 1, 1... to an outbound cooling water passage 4; operation count selection means for selecting cooling towers 5, 5... to be operated based on a total of the values of the loads of the heat sources 1, 1... acquired by the load acquisition means; fan air volume control means for controlling rotation of a fan 5a corresponding to burdens of the cooling towers to be operated; and inbound cooling water passage flow rate control means for automatically controlling a flow rate of an inbound cooling water passage 6. Sequence control is performed on the load acquisition means, the outbound cooling water passage flow rate control means, the operation count selection means, the fan air volume control means and the inbound cooling water passage flow rate control means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control device and a control method for an air-conditioning water-cooling cycle in an air-conditioning facility equipped with a plurality of heat sources. [Background technology]

[0002] 2. Description of the Related Art Conventionally, air conditioning equipment configured with an air conditioning water-cooling cycle including an air conditioning indoor unit and a cooling tower has been widely used in large buildings such as factories and commercial facilities.

[0003] Since the energy consumed by this type of air conditioning equipment accounts for a large proportion of the total energy consumed by a building, energy conservation in air conditioning equipment has become an important issue.

[0004] Measures for reducing energy consumption in air conditioning equipment include, for example, performing a simulation to calculate the amount of energy consumed by the entire heat source system using many operating condition parameters such as the outside air wet-bulb temperature and the cooling water temperature, and then reviewing the system based on the results to reduce energy (see, for example, Patent Document 1), and variably controlling the rotation speed of the cooling water pump motor using a linear equation that shows the relationship between a predetermined load factor of the chiller (heat source) and the temperature difference between the return and return cooling water (see, for example, Patent Document 2).

[0005] Also, among this type of air conditioning equipment, there are known systems that control the number of cooling towers in operation (see, for example, Patent Document 3) and systems that control the air volume of the cooling towers (see, for example, Patent Document 4). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2011-002111 A [Patent Document 2] Patent Publication No. 2021-055975 [Patent Document 3] JP 2020-041767 A [Patent Document 4] JP 2009-250578 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the conventional techniques such as those shown in the above-mentioned Patent Documents 1 and 2, calculations using complex formulas must be performed, which makes the processing cumbersome and requires expensive equipment to perform the complex calculation processing.

[0008] Furthermore, in the conventional technologies such as those shown in the above-mentioned Patent Documents 3 and 4, the number of operating cooling towers and the air volume are merely controlled individually, and the number of operating cooling towers, the air volume, the flow rate of cooling water, etc. are not controlled in a comprehensive manner with the aim of saving energy in the entire system.

[0009] In view of the above-mentioned problems, the present invention has been made with an object to provide a control device and a control method for an air-conditioning water-cooling cycle that can efficiently achieve energy savings with a simple configuration. [Means for solving the problem]

[0010] The feature of the invention described in claim 1 for solving the above-mentioned conventional problems is a control device for an air-conditioning water-cooling cycle in which cooling water is sent from multiple heat sources connected to an air-conditioning indoor unit through a forward cooling water channel to multiple cooling towers, and which has been heat exchanged in the cooling towers and circulated to the multiple heat sources through a return cooling water channel, the control device comprising: a load acquisition means for acquiring the load of each of the heat sources; a forward cooling water channel flow rate control means for comparing the load value of each heat source acquired by the load acquisition means with a preset threshold value to control the flow rate of the cooling water flowing from each of the heat sources into the forward cooling water channel; an operating number selection means for selecting a cooling tower to be operated based on the sum of the load values ​​of each heat source acquired by the load acquisition means; a fan airflow control means for controlling the rotation of the fan in accordance with the load of each operating cooling tower; and a return cooling water channel flow rate control means for automatically controlling the flow rate of the return cooling water channel, and the load acquisition means, the forward cooling water channel flow rate control means, the operating number selection means, the fan airflow control means, and the return cooling water channel flow rate control means are sequentially controlled.

[0011] The feature of the invention described in claim 2 is that, in addition to the configuration of claim 1, the load acquisition means is provided for each heat source with an inflow temperature measurement means for measuring the temperature of the inflow water flowing from the heat source into the return cooling water channel, and a power measurement means for measuring power consumption, and calculates the load of each heat source based on the measured inflow water temperature and the power consumption.

[0012] The invention described in claim 3 is characterized in that, in addition to the configuration of claim 1, the recirculation cooling water channel flow rate control means comprises an end pressure measuring means for measuring a change in water pressure in the piping at the end of the recirculation cooling water channel, and a pump control means for controlling the output of the cooling water pump so that the water pressure in the piping becomes a preset threshold value, and the flow rate of the recirculation cooling water channel is controlled.

[0013] The invention described in claim 4 is characterized in that, in addition to the configuration of claim 1, the cooling tower is configured as a closed cooling tower and is equipped with a sprinkler pump control means for sprinkling water supplied from the outside onto the outside of the cooling tower's internal piping.

[0014] The feature of the invention described in claim 5 is that in a control method for an air-conditioning water-cooling cycle in which cooling water is sent from multiple heat sources connected to an air-conditioning indoor unit through a forward cooling water passage to multiple cooling towers and circulated through a return cooling water passage to the multiple heat sources after heat exchange in the multiple cooling towers, the control method continuously performs the following steps: acquiring the load of each heat source; comparing the acquired load value of each heat source with a preset threshold value to control the flow rate of the cooling water flowing from each heat source to the forward cooling water passage; selecting a cooling tower to be operated based on the sum of the acquired load values ​​of each heat source; controlling the rotation of a fan in accordance with the load of each operating cooling tower; and automatically controlling the flow rate of the return cooling water passage.

[0015] The feature of the invention described in claim 6 is that, in addition to the configuration of claim 5, the temperature of the inflow water flowing from the heat source into the return cooling water channel and the power consumption are measured for each heat source, and the load of each heat source is calculated based on the measured temperature of the inflow water and the power consumption.

[0016] The invention described in claim 7 is characterized in that, in addition to the configuration of claim 5, the cooling water pump control means measures the change in water pressure in the piping using an end pressure measuring means installed at the end of the recirculation cooling water passage, controls the output of the cooling water pump so that the water pressure in the piping becomes a preset threshold value, and controls the flow rate of the recirculation cooling water passage.

[0017] The invention described in claim 8 is characterized in that, in addition to the configuration of claim 5, a closed cooling tower is used as the cooling tower, and water supplied from outside is sprayed on the outside of the internal piping of the cooling tower. Effect of the Invention

[0018] The control device for an air-conditioning water-cooling cycle according to the present invention is provided with the configuration recited in claim 1, and thus can efficiently achieve energy savings in an air-conditioning facility in a comprehensive manner with a simple configuration that does not require complex calculations.

[0019] Furthermore, by being provided with the configuration recited in claim 2, the present invention makes it possible to easily calculate the load of each heat source.

[0020] Furthermore, in the present invention, by providing the configuration recited in claim 3, the cooling water pump can be controlled accurately.

[0021] Furthermore, in the present invention, by providing the configuration recited in claim 4, the sprinkler pump can be controlled accurately.

[0022] The method for controlling an air-conditioning water-cooling cycle according to the present invention is provided with the configuration recited in claim 5, thereby making it possible to efficiently achieve energy conservation in an air-conditioning facility without using complex calculations.

[0023] In addition, in the present invention, by providing the configuration recited in claim 6, the load of each heat source can be calculated easily.

[0024] Furthermore, in the present invention, by providing the configuration recited in claim 7, the cooling water pump can be controlled accurately.

[0025] Furthermore, in the present invention, by providing the configuration recited in claim 8, the sprinkler pump can be controlled accurately. [Brief description of the drawings]

[0026] [Figure 1] 1 is a block diagram showing an outline of an air conditioning facility using a control device for an air conditioning water-cooling cycle according to the present invention; [Diagram 2] 3 is a flowchart showing a method for controlling an air-conditioning water-cooling cycle according to the present invention. [Diagram 3] 3 is a sub-flowchart of the heat source load acquisition step in FIG. 2. [Figure 4] 4 is a sub-flowchart of the supply cooling water channel inflow amount control according to the embodiment of the present invention. [Diagram 5] 13 is a sub-flowchart of the process of selecting the number of cooling towers in operation according to the embodiment of the present invention. [Figure 6] 1 is a sub-flowchart of the above-mentioned cooling tower fan air volume control and recirculation cooling water channel flow rate control process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Next, an embodiment of a control device for an air-conditioning water-cooling cycle and a control method thereof according to the present invention will be described with reference to the examples shown in Figures 1 to 6. Figure 1 is a block diagram showing an outline of an air-conditioning facility.

[0028] This air conditioning equipment is equipped with an air conditioning water cooling cycle A in which cooling water is sent from multiple heat sources 1, 1... connected to air conditioning indoor units through a supply cooling water passage 4 to multiple cooling towers 5, 5... and which circulates the cooling water that has been heat exchanged in the cooling towers 5, 5... to the multiple heat sources 1, 1... through a return cooling water passage 6, and the air conditioning water cooling cycle A is controlled by a control device to achieve energy conservation.

[0029] Each heat source 1, 1... is composed of a heat exchanger such as a condenser that exchanges exhaust heat from an air conditioning indoor unit (not shown), and one end of the heat exchanger is connected to the outgoing cooling water passage 4 and the other end is connected to the return cooling water passage 6. Note that the N (in this embodiment, N=3) heat sources 1, 1... will be described by appropriately assigning numbers n=1 to N according to the order of processing. The number N of heat sources 1, 1... is not limited to N=3 and can be freely set according to the scale of the air conditioning equipment.

[0030] Then, from each heat source 1, 1..., the cooling water whose temperature has increased due to heat exchange is sent through the forward cooling water passage 4 by the conveying force of the cooling water pump 7 to the cooling towers 5, 5..., where the cooling water exchanges heat with the outside air in the cooling towers 5, 5..., releasing heat to lower the temperature of the cooling water, and the cooling water is sent from the cooling towers 5, 5... to each heat source 1, 1.... Note that the reference numeral 8 in the figure denotes a check valve.

[0031] The flow rate of the cooling water pump 7 can be adjusted by control of an inverter 9, and a pressure gauge 10 is provided at the downstream end of the cooling water pump 7.

[0032] The cooling towers 5, 5... are equipped with fans 5a that blow air toward the main body trunk, and by blowing air toward the cooling water circulating inside the main body trunk, heat is exchanged between the cooling water and the outside air, thereby cooling the cooling water.

[0033] The fan 5a is capable of controlling the amount of air blown by adjusting the rotation speed of a motor that drives the fan 5a using an inverter 11.

[0034] The cooling towers 5, 5 . . . may be either an open type cooling tower or a closed type cooling tower.

[0035] The open type cooling tower has a simple structure in which cooling water flowing in through the supply cooling water passage 4 is sprayed inside the main body, and the sprayed cooling water is directly exposed to the outside air taken in by the fan 5a.

[0036] On the other hand, a closed cooling tower circulates cooling water through internal piping installed inside the main body of the cooling tower 5, 5..., and sprays water supplied from the outside through a spray pump control means onto this internal piping, while also exposing it to outside air taken in by a fan 5a.

[0037] The control device for this air-conditioning water-cooling cycle A comprises a load acquisition means for acquiring the load of each heat source 1, 1..., a forward cooling water channel flow rate control means for controlling the flow rate of cooling water flowing from each heat source 1, 1... into the forward cooling water channel 4, an operating number selection means for selecting the cooling towers 5, 5... to be operated, a fan air volume control means for controlling the rotation of the fan 5a in accordance with the load of each operating cooling tower 5, 5..., and a return cooling water channel flow rate control means for automatically controlling the flow rate of the return cooling water channel 6, and the forward cooling water channel flow rate control means, the operating number selection means, the fan air volume control means and the return cooling water channel flow rate control means are sequence-controlled by a control device main body 12 consisting of a control panel or the like based on information acquired from the load acquisition means.

[0038] The control device main body 12 is composed of a control panel consisting of computer equipment equipped with an arithmetic device, storage media, etc., and is connected to devices constituting a load acquisition means, a forward cooling water channel flow control means, a fan air volume control means, a return cooling water channel flow control means, etc., and stores programs for controlling the load acquisition means, the forward cooling water channel flow control means, the number of operating units selection means, the fan air volume control means, and the return cooling water channel flow control means.

[0039] The load acquisition means is provided for each heat source 1, 1... with a thermometer (not shown) that measures the temperature of the inflow water flowing from the heat sources 1, 1... into the supply cooling water channel 4, and a power measurement means (not shown) that measures the power consumption of the heat sources 1, 1..., and data is transmitted from the inflow temperature measurement means and the power measurement means to the control device main body 12 at any time, and the load of each heat source 1, 1... is calculated based on the inflow water temperature and power consumption measured in the control device main body 12.

[0040] The power consumption of the heat sources 1, 1... is calculated by measuring the voltage and current consumption of each heat source 1, 1... using a voltmeter and ammeter installed in each heat source 1, 1..., and calculating the product of these values, i.e., power consumption = voltage x current.

[0041] The forward cooling water channel flow rate control means controls the flow rate of cooling water flowing from each heat source 1, 1... into the forward cooling water channel 4 by comparing the load value of each heat source 1, 1... obtained by the load acquisition means with a preset threshold value stored in the database of the control device main body 12.

[0042] This return cooling water channel flow rate control means is provided with on-off valves 13, 13... between each heat source 1, 1... and the return cooling water channel 4, each of which can adjust the flow rate by changing the degree of opening and closing, and by controlling the on-off valves 13, 13..., it is possible to control the flow rate of cooling water flowing from each heat source 1, 1... into the return cooling water channel 4.

[0043] The operating number selection means is constituted by a program stored in the control device main body 12, and calculates the sum of the thermal load values ​​of the heat sources 1, 1..., and based on that, divides the total thermal load by the maximum processable load per cooling tower, thereby calculating the number of operating cooling towers 5, 5... required for heat treatment.

[0044] The fan airflow control means determines the fan airflow required for heat exchange by comparing the load on each operating cooling tower 5, 5... with a preset threshold value stored in the database of the control device main body 12, and controls the rotation of the fan 5a by the inverter 11.

[0045] The recirculation cooling water channel flow control means is configured to automatically control the output of the cooling water pump 7 using an end pressure measuring means consisting of a pressure gauge 10 that measures the water pressure change in the piping at the end, and an inverter 9, which is a pump control means, so that the water pressure in the piping becomes a preset threshold value.

[0046] In addition, the return cooling water channel flow rate control means is provided with on-off valves 14, 14... that can be opened and closed between the supply cooling water channel 4 and each cooling tower 5, 5..., and is configured to open the on-off valves 14, 14 of the cooling tower 5 that is operating based on the selection of the number of operating units, thereby controlling the return cooling water channel flow rate.

[0047] Next, a specific control method performed by this control device will be described with reference to the flowcharts shown in FIGS.

[0048] As shown in Figure 2, when operation is started, the control method for this air-conditioning water-cooling cycle A first involves a process (load acquisition process S1) of acquiring the load related to each heat source 1, 1... using a load acquisition means in order starting from heat source 1 (n=1), and a process (forward cooling water channel flow rate control process S2) of controlling the flow rate flowing from each heat source 1, 1... into the forward cooling water channel 4 based on the load of each heat source 1, 1..., which are repeated (L1) the number N of heat sources 1, 1... (N=3 in this embodiment), outputting thermal load data for each heat source 1, 1..., and causing cooling water to flow from each heat source 1, 1... into the forward cooling water channel 4.

[0049] As shown in FIG. 3, the load acquisition process S1 first measures the voltage and current consumption of heat source 1 (n=1) (s11), and the measurement data is output to the control device main body 12. The voltage and current consumption are multiplied together to calculate the power consumption of heat source 1 (n=1) = voltage consumption x current consumption (s12).

[0050] Next, the calculated power consumption is compared with the standby power (s13). If the power consumption is less than the standby power, the thermal load of heat source 1 (n=1) is output as 0 (s14). If the power consumption is greater than the standby power, measurement of the inflow water temperature from heat source 1 (n=1) to the supply cooling water channel 4 is started (s15), and the calculated power consumption value is output (s16).

[0051] Furthermore, when the inflow water temperature from the heat source 1 (n=1) to the supply cooling water passage 4 is measured, the inflow water temperature of the heat source 1 (n=1) is output (s17) and calculation of the rated load is started.

[0052] When the inflow water temperature from the heat source 1 (n=1) to the supply cooling water channel 4 is output, a list of capacity correction values ​​corresponding to the preset inflow water temperatures is called up from the database A-2 (s18), a threshold value for the capacity correction value appropriate to the inflow water temperature is selected from the list, and it is output as the capacity correction value (s19).

[0053] The list of performance correction values ​​stored in the database A-2 is obtained from the catalog data of the heat source 1, experimental results, etc.

[0054] On the other hand, the rated load is calculated immediately after starting operation, that is, by checking whether this is the first time the loop in the flowchart is being executed (s110). If this is the first time, there is a risk that the cooling water temperature may be high, so to be safe, the rated maximum load is output as the thermal load of heat source 1 (n=1) (s111).

[0055] Then, once operation has stabilized (the loop is running for the second or subsequent time), the inflow water temperature is compared with a preset value (s112), and if the inflow water temperature exceeds the set value, the rated maximum load is output as the thermal load of heat source 1 (n=1) (s111), and if the inflow water temperature is below the set value, a list of input correction values ​​corresponding to the water temperature is called up from database A-1, and a threshold value appropriate for the input correction value corresponding to the water temperature is selected from the list (s113), and this is output as the input correction value (s114).

[0056] The list of input correction values ​​stored in the database A-1 is obtained from catalog data of the heat source 1, experimental results, and the like.

[0057] Then, the output power consumption value of heat source 1 (n=1) is divided by the input correction value to calculate the converted power consumption value=power consumption value / input correction value (s115), and the data is output (s116).

[0058] Furthermore, the heat load curve is retrieved from the database B-1, and the rated heat load corresponding to the converted power consumption value output from the heat load curve is derived (s117), and is output (s118).

[0059] The heat load curves stored in the database B-1 are obtained from catalog data of the heat sources 1, 1 . . . , experimental results, and the like.

[0060] Next, the outputted rated thermal load is divided by the outputted capacity correction value (s119), and the thermal load of heat source 1 (n=1)=rated thermal load / capacity correction value is output (s120).

[0061] The last acquired heat load is output to the supply cooling water channel flow rate control means and is stored as heat load information of the heat source 1 (n=1) (s121).

[0062] Then, this series of heat load acquisition steps S1 is repeated the number of times N (N=3 in this embodiment) for the heat sources, and the heat loads of the heat sources 1, 1... are output to the forward cooling water channel flow control means and stored as heat load information for the heat sources 1, 1... (S3).

[0063] As shown in Figure 4, the forward cooling water channel flow rate control process S2 repeats the process of opening and closing valves interposed between each heat source 1, 1... and the forward cooling water channel 4 to control the amount of cooling water flowing into the forward cooling water channel 4 in accordance with the thermal load of each heat source 1, 1... up to the number N of heat sources 1, 1... (N = 3 in this embodiment).

[0064] Specifically, the output thermal load of heat source 1 (n=1) is checked (s21, s22), and if 0 is output as the thermal load (s14), valve 13 of heat source 1 (n=1) is closed to prevent operation (s23), and if the rated maximum load is output as the thermal load of heat source 1 (n=1) (s111), the valve of heat source 1 (n=1) is fully opened (s24).

[0065] On the other hand, when the value of the heat load of heat source 1 (n=1) calculated as the heat load of heat source 1 (n=1) is output (s120), a list of required flow rate values ​​corresponding to the heat load is called up from database B-2, a threshold value of the required flow rate value appropriate for the heat load is selected from the list (s25), and that value is output (s26).

[0066] The list of required flow rates adapted to the heat loads stored in the database B-2 is obtained from catalog data of the heat sources 1, 1 . . . , experimental results, etc.

[0067] Then, based on the required flow rate value that has been output, a list of opening and closing data for the valve 13 in relation to the flow rate is called up from database C (s27), and based on that data, the valve is repeatedly controlled to open and close (s28) until the opening and closing degree corresponding to the flow rate is reached (s29).

[0068] The list of valve opening / closing data for flow rates stored in database C uses data obtained from valve catalog data, experimental results, etc.

[0069] This series of steps S2 for controlling the flow rate of the forward cooling water passage is repeated a number of times equal to the number N of the heat sources 1 (N=3 in this embodiment), and cooling water is caused to flow into the forward cooling water passage 4 from each of the heat sources 1, 1 . . .

[0070] Next, when the heat load data of each heat source 1, 1... is output (S3), the heat load values ​​of each heat source 1, 1... are added up based on the heat load data of each heat source 1, 1... and the total heat load value is output (S4). Based on this, the number of operating cooling towers is selected (operating cooling tower number selection process S5), and a process of controlling the rotation of the fans 5a of the operating cooling towers 5, 5... (operating cooling tower air volume control process) and a process of automatically controlling the flow rate of the supply cooling water channel 4 (return cooling water channel flow rate control process) are executed (S6).

[0071] Specifically, the heat load values ​​of each heat source 1, 1 ... are added up based on the heat load data of each heat source 1, 1 ... output initially, and the total heat load value is output (S3), after which the process proceeds to the step S5 of selecting the number of operating cooling towers.

[0072] In the process S5 for selecting the number of operating cooling towers, first, the total heat loads are compared (s51). If the total heat load value is 0, the number of operating cooling towers is output as 0 (s52). If the total heat load value is greater than 0, the maximum heat load that can be processed per cooling tower is retrieved from database D, and the total heat load value is divided by the maximum heat load that can be processed per cooling tower to calculate the required number of operating cooling towers = total heat load value / maximum heat load that can be processed per cooling tower (s53).

[0073] The maximum heat load that can be processed per cooling tower stored in the database D is obtained from the catalog data, experimental results, etc. of the cooling towers 5, 5 . . .

[0074] Next, immediately after the start of operation, the cooling towers 5, 5... are not in operation and the time since the cooling towers 5, 5... started operating does not exceed the set time (s54). Therefore, if the calculated number of operating cooling towers exceeds the set initial number of operating cooling towers (s55), the calculated number of operating cooling towers is output as the number of operating cooling towers (s56), and if the calculated number of operating cooling towers is below the set initial number of operating cooling towers, the initial number is output as the number of operating cooling towers (s57).

[0075] Here, the initial number of operating units refers to a number that is set in advance to be larger than the number of units so that when the cooling towers 5, 5... start operation, the cooling water that has flowed into the cooling towers 5, 5... from the forward cooling water passage 4 has moved to the return cooling water passage 6 side. By setting this initial number of operating units, it is possible to obtain the same effect as "initially opening the on-off valves 14, 14... of all cooling towers 5, 5...".

[0076] Furthermore, when the calculated number of operating cooling towers exceeds the set initial number of operating cooling towers, such a problem does not occur, and the calculated number of operating cooling towers can be output as the number of operating cooling towers as is.

[0077] Next, as shown in FIG. 6, in the operating cooling tower air volume control process and the return cooling water channel flow rate control process S7, first, the calculated total heat load value is checked (s71), and if the total heat load value is 0, the cooling water pump 7 is stopped (s72), the fans 5a of the cooling towers 5, 5... are not operated either (s73), the time since the cooling water pump 7 was stopped is measured in this state (s74), and after a certain time has elapsed (s75), the opening / closing valves 14, 14... on the return cooling water channel 6 side of the cooling towers 5, 5... are fully opened (s76).

[0078] The on-off valves 14, 14 . . . of the cooling towers 5, 5 .

[0079] On the other hand, if the calculated total heat load value exceeds 0, the cooling water pump 7 is started (s77), the water pressure at the end of the cooling water pump 7 is measured (s79), and the inverter is controlled until the water pressure reaches the set water pressure (s78, s710).

[0080] Then, when the water pressure at the end of the cooling water pump 7 reaches the set water pressure, the total heat load value is divided by the number of operating cooling towers for which the output is given, and the heat processing capacity per cooling tower = the number of operating cooling towers for which the total heat load value is given is calculated (s711), and this is output (s712).

[0081] Next, a list of fan airflow rates corresponding to the heat treatment capacity per cooling tower is called up from database E, a threshold value that is appropriate for the heat treatment capacity per cooling tower calculated from the list is selected (s713), and this is output as the heat treatment capacity per cooling tower (s714).

[0082] Furthermore, a list of inverter frequencies corresponding to the fan airflow is called up from database F (s715), and a threshold value of the inverter frequency adapted to the fan airflow is output from the list (s716). The fans 5a of the operating cooling towers 5, 5... are inverter-controlled (s717), and the cooling water on-off valves 14, 14... of the operating cooling towers 5, 5... are opened (s718).

[0083] As a result, the heat source load acquisition process S1, the forward cooling water channel flow rate control process S2, the process S5 of selecting the number of operating cooling towers, the operating cooling tower air volume control process and the return cooling water channel flow rate control process are processed in sequence, and the time since operation started is measured (S7). After a certain time has elapsed (S8), if operation is to be continued, the heat source load acquisition process S1, the forward cooling water channel flow rate control process S2, the process S5 of selecting the number of operating cooling towers, the operating cooling tower air volume control process and the return cooling water channel flow rate control process are repeated in sequence again to perform sequence control (L2), and if operation is not to be continued, operation is terminated (S9).

[0084] The control of the air conditioning water-cooling cycle A configured in this manner can comprehensively minimize the energy consumption of the entire air conditioning facility by performing sequence control with a minimum number of parameters without the need for complex calculations. [Explanation of symbols]

[0085] 1 heat source 4 Outward cooling waterway 5 cooling tower 6 Re-cooling waterway 7. Cooling Water Pump 8. Check valve 9. Inverter 10. Water pressure gauge 11 Inverter 12 Control device main body 13. On-off valve 14 On-off valve

Claims

1. A control device for an air-conditioning water-cooling cycle in which cooling water is sent from a plurality of heat sources connected to an air-conditioning indoor unit through a forward cooling water passage to a plurality of cooling towers, and the cooling water that has been heat-exchanged in the cooling towers is circulated to the plurality of heat sources through a return cooling water passage, A load acquisition means for acquiring a load of each of the heat sources; a forward cooling water passage flow rate control means for controlling a flow rate of the cooling water flowing from each heat source to the forward cooling water passage by comparing a value of the load of each heat source acquired by the load acquisition means with a preset threshold value; an operating number selection means for selecting a cooling tower to be operated based on the total load value of each heat source acquired by the load acquisition means; A fan air volume control means for controlling the rotation of the fan in accordance with the load of each operating cooling tower; a re-cooling water passage flow rate control means for automatically controlling a flow rate of the re-cooling water passage, A control device for an air-conditioning water-cooling cycle, characterized in that the load acquisition means, the forward cooling water channel flow rate control means, the operating number selection means, the fan air volume control means, and the return cooling water channel flow rate control means are sequence controlled.

2. 2. The control device for an air-conditioning water-cooling cycle as described in claim 1, wherein the load acquisition means includes, for each heat source, an inflow temperature measurement means for measuring the temperature of inflow water flowing from the heat source into the return cooling water channel, and a power measurement means for measuring power consumption, and calculates the load of each heat source based on the measured inflow water temperature and the power consumption.

3. The control device for an air-conditioning water-cooling cycle as described in claim 1, characterized in that the recirculation cooling water channel flow rate control means includes an end pressure measuring means for measuring a change in water pressure in the piping at the end of the recirculation cooling water channel, and a pump control means for controlling the output of the cooling water pump so that the water pressure in the piping becomes a preset threshold value, and the flow rate of the recirculation cooling water channel is controlled.

4. 2. The control device for an air-conditioning water-cooling cycle according to claim 1, wherein the cooling tower is a closed cooling tower, and further comprises a sprinkling pump control means for sprinkling water supplied from the outside onto the outside of the internal piping of the cooling tower.

5. A control method for an air-conditioning water-cooling cycle in which cooling water is sent from a plurality of heat sources connected to an air-conditioning indoor unit through a forward cooling water passage to a plurality of cooling towers, and cooled water that has been heat-exchanged in the plurality of cooling towers is circulated to the plurality of heat sources through a return cooling water passage, obtaining a load for each of the heat sources; a step of comparing the acquired load value of each heat source with a preset threshold value to control a flow rate of the cooling water flowing from each heat source into the supply cooling water passage; A step of selecting a cooling tower to be operated based on a sum of the load values ​​of each heat source obtained; Controlling the rotation of the fan according to the load of each operating cooling tower; and automatically controlling the flow rate of the re-cooling water passage. A method for controlling a water-cooling cycle for air conditioning, characterized in that the method is carried out continuously.

6. 6. A method for controlling an air-conditioning water-cooling cycle as described in claim 5, further comprising the steps of: measuring the temperature of inflow water flowing from the heat source into the return cooling water channel and the power consumption for each heat source; and calculating the load of each heat source based on the measured temperature of the inflow water and the power consumption.

7. The control method for an air-conditioning water-cooling cycle according to claim 5, characterized in that the cooling water pump control means measures a change in water pressure in the piping using an end pressure measuring means installed at the end of the recirculation cooling water passage, controls the output of the cooling water pump so that the water pressure in the piping reaches a preset threshold value, and controls the flow rate of the recirculation cooling water passage.

8. 6. The method for controlling a water-cooling cycle for air conditioning according to claim 5, wherein a closed cooling tower is used as the cooling tower, and water supplied from outside is sprayed onto the outside of an internal piping of the cooling tower.

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