Control device, control method and control program for air conditioning system and air conditioning system

Abstract

To provide an air conditioning control technique capable of appropriately determining a control target value of an air conditioning system in the air conditioning system in which a space having a heat source is set as an air conditioning target.SOLUTION: An air conditioning system executes: first processing for acquiring a value correlated with heat quantity generated in a heat source from the heat source or an apparatus connected to the heat source as an input value; second processing for performing, with respect to each of a plurality of alternated virtual control target values, processing for calculating a virtual temperature of a space when an air conditioning apparatus is operated at a specific control target value from the input value and characteristic data, after acquisition of the input value through the first processing; and third processing for determining a virtual control target value that enables the virtual temperature calculated in the second processing to satisfy a temperature condition specified in the space and minimizes electric power consumption of an entire system at least including the air conditioning system, out of the plurality of the virtual control target values, as a control target value of the air conditioning apparatus.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control device, a control method, a control program, and an air conditioning system. [Background technology]

[0002] In recent years, computers have been used to control air conditioning systems (see, for example, Patent Documents 1 to 5). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-031536 [Patent Document 2] Japanese Patent Application Publication No. 2018-031538 [Patent Document 3] Japanese Patent Application Publication No. 2018-031537 [Patent Document 4] Japanese Patent Application Publication No. 2018-031534 [Patent Document 5] Japanese Patent Application Publication No. 2018-031535 Summary of the Invention [Problem to be solved by the invention]

[0004] To efficiently operate an air conditioning system that includes components such as chillers, cooling towers, blower fans, and pumps, various control target values, such as the set temperature of the chilled water cooled by the chiller and the set temperature of the cooling water cooled by the cooling tower, must be determined to appropriate values ​​according to the space being air-conditioned and the outside air conditions.

[0005] In the case of rooms where people stay, such as offices, commercial facilities, and homes, there are no heat sources that can suddenly change the temperature in the space, so it is relatively difficult to identify the optimal control target value used for feedback control using a PLC (Programmable Logic Controller) in an air conditioning system. On the other hand, in spaces where various heat sources exist, such as data centers with many information processing devices or factories where various machines such as semiconductor manufacturing equipment are in operation, the optimal control target value used in feedback control is not uniform because it depends on the state of the heat source. For this reason, it is desirable to use feedforward control, which dynamically changes the control target value depending on the state of the heat source, but because the state of the heat source changes from moment to moment, it is not easy to continue to dynamically change the control target value to an optimal value in an air conditioning system in a space where a heat source is located.

[0006] Therefore, the present application discloses an air conditioning control technology that can appropriately determine a control target value of an air conditioning system that targets air conditioning of a space where a heat source is present. [Means for solving the problem]

[0007] In order to solve the above problem, in the present invention, when a value correlating with the amount of heat generated by the heat source is obtained, a process of calculating the virtual temperature of the space when the air conditioning equipment is operated at a specific control target value is performed for each of multiple virtual control target values ​​with alternating values, and the virtual control target value among the multiple virtual control target values ​​that satisfies the temperature conditions and minimizes power consumption is determined as the control target value for the air conditioning equipment.

[0008] In detail, the present invention is a control device for an air conditioning system that conditions a space in which a heat source is located, and includes a storage unit that stores characteristic data of air conditioning equipment of the air conditioning system, and a processing unit that determines a control target value for the air conditioning equipment based on the data in the storage unit. The processing unit acquires a value correlated with the amount of heat generated by the heat source as an input value from the heat source or equipment connected to the heat source. a first process for calculating a virtual temperature of the space when the air conditioning equipment is operated at a specific control target value from the input values ​​and characteristic data when the input values ​​are obtained by the first process, a second process for calculating a virtual temperature of the space when the air conditioning equipment is operated at a specific control target value from the input values ​​and characteristic data for each of a plurality of virtual control target values ​​with alternating values; and a third process for determining, as the control target value of the air conditioning equipment, a virtual control target value among the plurality of virtual control target values ​​such that the virtual temperature calculated by the second process satisfies a temperature condition specified for the space and that minimizes the power consumption of the entire system including at least the air conditioning system.

[0009] Here, a heat source is a source of heat that requires cooling by an air conditioning system, and examples include various machines such as servers, communication equipment, and semiconductor manufacturing equipment, as well as various other heat sources.

[0010] Furthermore, characteristic data is data that indicates the performance of the air conditioning equipment of the air conditioning system, and includes, for example, data that indicates the correlation between capacity and power consumption.

[0011] The virtual temperature of a space is a calculated temperature at one or more measurement points set within the space, and in the case of a data center, for example, the temperature of a hot aisle.

[0012] Furthermore, the entire system refers to a group of devices related to the power consumption value that the air conditioning system's control device is trying to minimize. For example, if the control device is trying to minimize the power consumption of the air conditioning system, it refers to all of the air conditioning devices that make up the air conditioning system.

[0013] According to the above-described air conditioning system, the control target value of the air conditioning equipment is determined using a value correlated with the amount of heat generated by the heat source. This control target value is calculated using characteristic data of the air conditioning equipment, and is a value that satisfies the specified temperature conditions for the space and minimizes the power consumption of the entire system, including the air conditioning system. Therefore, if such a control target value is set as the control target value of the air conditioning equipment, the air conditioning system can minimize power consumption by cooling the heat source located in the space to be air-conditioned just enough.

[0014] The heat source may be information processing equipment, the air conditioning system may be configured to condition a space in a data center where multiple rows of racks containing information processing equipment are arranged, and the input value may be the power consumption of the information processing equipment. In this way, the air conditioning system can minimize power consumption by determining a control target value for the air conditioning equipment according to the heat generation amount of the information processing equipment in the data center.

[0015] The air conditioning system may include a first process for acquiring, as an input value, the total power consumption of the information processing devices housed in the rack corresponding to a specific air conditioning unit for each air conditioning unit, a second process for calculating, from the input value and characteristic data, a virtual temperature when the air conditioning devices including the air conditioning units are operated at specific control target values ​​for each of a plurality of virtual control target values ​​with alternating values, and a third process for determining, for each air conditioning unit, the minimum virtual control target value as the control target value for the air conditioning unit. This allows the air conditioning system to minimize power consumption by determining, for each rack, the control target values ​​for the air conditioning devices according to the heat generation amounts of the information processing devices.

[0016] The virtual temperature may also include the temperature of the space on the exhaust side of the rack. Typically, in a data center, the space on the exhaust side of the rack housing the information processing equipment becomes the hottest, so if the virtual temperature in that space satisfies the specified temperature conditions, it is possible to prevent the occurrence of locations in the air-conditioned space becoming excessively hot.

[0017] The virtual control target value may also include at least one of the temperature of the supply air to be supplied to the space and the temperature of the chilled water that cools the air to be supplied to the space. These are dominant control parameters in the air conditioning system, so if these are determined to values ​​corresponding to the heat quantity of the heat source, the entire air conditioning system can be brought into an optimal operating state.

[0018] Furthermore, the power consumption of the entire system may be the power consumption of the entire air conditioning system, or the power consumption of the entire air conditioning system combined with the heat source. For example, if the operating efficiency of the heat source correlates with the operating state of the air conditioning system, the entire air conditioning system can be brought into an optimal operating state by determining a control target value that minimizes the overall power consumption including the heat source.

[0019] In the second process, the processing unit may calculate a virtual temperature from the input value and the characteristic data for each of a plurality of virtual control target values ​​whose values ​​are staggered by a predetermined difference. This makes it possible to identify the virtual control target values ​​through stepwise calculation processes.

[0020] The present invention can also be viewed as a method. For example, the present invention may be a control method for an air conditioning system, in which a control device of the air conditioning system, which targets a space in which a heat source is located, executes the following steps: a first process in which a value correlating with the amount of heat generated by the heat source is acquired as an input value from the heat source or an apparatus connected to the heat source; a second process in which, upon acquiring the input value through the first process, a process in which a virtual temperature of the space when the air conditioning apparatus of the air conditioning system is operated at a specific control target value is calculated from the input value and characteristic data of the air conditioning apparatus, the process being performed for each of a plurality of virtual control target values ​​with alternating values; and a third process in which, among the plurality of virtual control target values, a virtual control target value that satisfies a temperature condition specified for the space and minimizes power consumption of the entire system including at least the air conditioning system is determined as the control target value for the air conditioning apparatus.

[0021] The present invention can also be understood from the aspect of a program. For example, the present invention may be a control program for an air conditioning system that causes a computer of the air conditioning system, which targets a space in which a heat source is located, to execute the following steps: a first process of acquiring, as an input value, a value correlated to the amount of heat generated by the heat source from the heat source or an apparatus connected to the heat source; a second process of calculating, upon acquiring the input value by the first process, a virtual temperature of the space when the air conditioning apparatus of the air conditioning system is operated at a specific control target value from the input value and characteristic data of the air conditioning apparatus, the virtual temperature being calculated for each of a plurality of virtual control target values ​​with alternating values; and a third process of determining, as the control target value for the air conditioning apparatus, a virtual control target value at which the virtual temperature calculated by the second process satisfies a specified temperature condition for the space and minimizes the power consumption of the entire system including at least the air conditioning system.

[0022] The present invention can also be viewed from the perspective of a system. For example, the present invention may be an air conditioning system that conditions a space in which a heat source is located, and includes a control device having an air conditioning device, a memory unit that stores characteristic data of the air conditioning device, and a processing unit that determines a control target value of the air conditioning device based on the data in the memory, wherein the processing unit executes: a first process that acquires a value correlated to the amount of heat generated by the heat source as an input value from the heat source or a device connected to the heat source; a second process that, upon acquiring the input value by the first process, calculates a virtual temperature of the space when the air conditioning device is operated at a specific control target value from the input value and the characteristic data, the second process performing this process for each of a plurality of virtual control target values ​​with alternating values; and a third process that determines, as the control target value of the air conditioning device, a virtual control target value at which the virtual temperature calculated by the second process satisfies a specified temperature condition for the space and minimizes the power consumption of the entire system including at least the air conditioning system. [Effects of the Invention]

[0023] The above-described air conditioning system control device, control method, control program, and air conditioning system make it possible to appropriately determine the control target value of an air conditioning system that targets air conditioning in a space where a heat source is present. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a diagram showing an example of an air conditioning system. [Figure 2] FIG. 2 is a diagram showing an example of an information processing equipment room. [Figure 3] FIG. 3 is a flowchart showing an outline of the process executed by the control device. [Figure 4] FIG. 4 is a diagram supplementing the above series of processing contents. [Figure 5] FIG. 5 is a flowchart showing the processing performed before the air conditioning system starts operating. [Figure 6] FIG. 6 is a flowchart showing the processing performed after the air conditioning system starts operating. [Figure 7] FIG. 7 is an image diagram of data relating to the characteristics of each air conditioning device that constitutes the air conditioning system. [Figure 8] FIG. 8 is a diagram showing an example of the results of creating an operation design sheet. [Figure 9] FIG. 9 is a diagram showing an example of the evaluation results of the indoor environment. [Figure 10] FIG. 10 is a diagram showing an image of the process for identifying the optimal operating conditions. [Figure 11] Figure 11 is a conceptual diagram of the calculation flow in optimization control. DETAILED DESCRIPTION OF THE INVENTION

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes embodiments of the present invention. The embodiments described below are merely examples of the present invention, and the technical scope of the present invention is not limited to the following aspects.

[0026] <System configuration> FIG. 1 is a diagram showing an example of an air conditioning system. The air conditioning system 1 is a system that controls the air conditioning of an information processing equipment room 2 installed in a data center building, and includes an air conditioning unit 11, a heat source device 12, and a return air duct 13. A typical example of the heat source device 12 included in the air conditioning system 1 is, but is not limited to, a heat pump using an air-cooled condenser. The heat source device 12 may be, for example, a heat source device having a turbo chiller, a cooling tower, and a cooling water circulation path, a chiller that cools the condenser with well water, or various other types of heat source devices. The cold energy from the heat source device 12 is transported to an air conditioning coil 17 of the air conditioning unit 11 via a chilled water circulation path formed by a chilled water pump 18, piping, etc. The air blown by the blower fan 16 of the air conditioning unit 11 is then cooled in the air conditioning coil 17. The air cooled by the air conditioning coils 17 is supplied from the air conditioning unit 11 to the information processing equipment room 2, and flows from the cold aisle 23 in the information processing equipment room 2 through the racks 22 to the hot aisle 21. The air flowing from the racks 22 to the hot aisle 21 is hot due to the exhaust heat from the information processing equipment in the racks 22. The hot air that has flowed into the hot aisle 21 flows from the return air duct 13 to the blower fan 16 of the air conditioning unit 11 as return air. It is then cooled by the air conditioning coils 17 and flows again as supply air to the information processing equipment room 2. In addition, some of the air circulating through the air conditioning system 1 is replaced with outside air through the exhaust vent 14 and the outside air inlet 15.

[0027] The air conditioning unit 11 may be a unit in which the blower fan 16 and the air conditioning coil 17 are integrated, or the blower fan 16 and the air conditioning coil 17 may be installed in an air conditioning equipment room partitioned within a building in which the information processing equipment room 2 is installed. In addition, the chilled water circulation path connecting the heat source unit 12 and the air conditioning coil 17 may carry a liquid such as brine instead of water. In addition, the air conditioning coil 17 may form an evaporator of a refrigeration cycle, and a refrigerant circulation path in which refrigerant gas circulates may be provided instead of the chilled water circulation path.

[0028] The air conditioning system 1 also includes a central controller (an example of the "controller" referred to herein) that is a host device that sends instructions to controllers included in air conditioning equipment such as the heat source unit 12, the chilled water pump 18, and the blower fan 16. The central controller may be located either inside the building in which the information processing equipment room 2 is located or at a remote location from the building. The central controller receives information from the controllers of the heat source unit 12 and other air conditioning equipment, information from various sensors included in the air conditioning system 1, the temperature conditions of the information processing equipment room 2, and various other information via a communication network or the like. Based on this information, the central controller determines control target values ​​and the like for the controllers of each air conditioning equipment in the air conditioning system 1. The controllers included in the heat source unit 12, the chilled water pump 18, the blower fan 16, and other air conditioning equipment perform feedback control to achieve the control target values ​​specified by the central controller, adjusting the motor rotation speed, valve opening, and the like.

[0029] FIG. 2 is a diagram showing an example of an information processing equipment room 2. As shown in FIG. 2, a large number of racks 22 are lined up in the information processing equipment room 2. The racks 22 house information processing equipment such as servers and communication devices that perform various types of calculation processing and database management. The racks 22 are equipped with cooling fans that cool the information processing equipment, and are configured so that the front of the rack is the intake side and the back is the exhaust side. Although FIG. 2 shows only one row of racks 22 lined up in a row, the information processing equipment room 2 has multiple such rows lined up.

[0030] In the information processing equipment room 2, the intake and exhaust sides of each rack 22 constituting one rack row are aligned so that cool air can be efficiently supplied from the cold aisle 23 to each rack 22. The racks 22 are installed in the information processing equipment room 2 so that the intake side of the rack 22 is in the cold aisle 23 and the exhaust side of the rack 22 is in the hot aisle 21. By installing each rack 22 in the information processing equipment room 2 in this manner, cool air supplied from the air conditioning unit 11 to the cold aisle 23 flows to the intake side of each cold aisle 23, is sucked into each rack 22, and is exhausted to the hot aisle 21.

[0031] The cooling fans for the information processing equipment in each rack 22 may be controlled so that their rotation speed changes from moment to moment depending on the load state of the information processing equipment housed in the rack and the intake temperature, or they may operate at a constant rotation speed. Furthermore, if there is a gap within the rack 22 or between adjacent racks 22 because no information processing equipment is installed in the rack 22, it is preferable that a panel or the like be installed in the gap to prevent warm air from the hot aisle 21 from flowing around to the cold aisle 23.

[0032] In the case of a wall-type air conditioning unit 11 installed on the side of a rack 22, if the air outlet faces the cold aisle 23, cool air can be efficiently circulated to the intake surface of each rack 22. Therefore, for example, if there are multiple cold aisles 23 in the information processing equipment room 2, the system configuration is simplified and control is facilitated if the air conditioning units 11 are installed in positions corresponding to each cold aisle 23. However, this positional relationship is not limited to this, and the air conditioning units 11 may be arranged in an appropriate positional relationship, for example, taking into account installation costs. Furthermore, the air conditioning system 1 is not limited to a configuration in which the air conditioning units 11 are installed on the side of the rack 22. For example, if the information processing equipment room 2 has a double-layered floor, the air conditioning system 1 may be configured such that cool air blown out from the air conditioning unit 11 passes under the floor of the information processing equipment room 2 and rises to the cold aisle 23 through a breathable member, such as a grating, that forms the floor surface of the cold aisle 23.

[0033] Various sensors are provided in the air conditioning system 1. For example, as shown in FIG. 2, the sensors provided in the air conditioning system 1 include a temperature sensor Ts that measures the temperature of the supply air blown out from the air conditioning unit 11, one or more temperature sensors that measure the temperatures of each part of the cold aisle 23, and These include a sensor Tc, one or more temperature sensors Th that measure the temperature of the hot aisle 21, and a differential pressure sensor dP that measures the differential pressure between the cold aisle 23 and the hot aisle 21. The air conditioning system 1 is also equipped with, for example, a sensor that measures the air volume of the blower fan 16, a sensor that measures the flow rate of the chilled water pump 18, a sensor that measures the temperature of the chilled water coming from the heat source unit 12, and a sensor that measures the temperature of the chilled water coming from the air conditioning coil 17. The air conditioning system 1 is also equipped with a wattmeter or ammeter that measures the power consumption of the blower fan 16, the chilled water pump 18, the heat source unit 12, and the information processing equipment installed in the rack 22. The power consumption of the information processing equipment may be information provided as data from the information processing equipment instead of being measured by a wattmeter or ammeter provided in the air conditioning system 1. Information from these sensors is provided to a central controller or the controllers of each air conditioning device, and, for example, the blower fan 16 blows air so that a certain degree of pressure difference is created between the cold aisle 23 and the hot aisle 21, thereby ensuring airflow from the cold aisle 23 to the hot aisle 21.

[0034] <Processing Overview> The following is an outline of the processing executed by the central controller. Fig. 3 is a flowchart showing an outline of the processing executed by the central controller. The central controller is equipped with a storage device that stores characteristic data of each air conditioning device, a CPU (Central Processing Unit) that determines the load distribution of each heat source device based on the data in the storage device, an input / output interface, etc. The CPU executes the computer program stored in the memory, thereby achieving the following processing:

[0035] That is, the central controller performs a process (S1) of measuring the power consumption of the information processing devices housed in the racks 22, and then uses a search engine to search for air conditioning conditions (such as supply air temperature and volume, and supply water temperature) (S2). Next, the central controller narrows down the searched air conditioning conditions to those that meet the conditions and constraints (S3). The central controller then extracts the narrowed down air conditioning conditions as the control target values ​​(hereinafter sometimes referred to as "operation set values") for the air conditioning devices (S4). The central controller performs these processes for each rack row consisting of a row of racks 22, and determines the supply air volume and supply air temperature of the air conditioning units 11 on a zone-by-zone basis (the area served by one air conditioning unit 11).

[0036] In the processing of step S1, the central controller calculates the power consumption of the information processing equipment housed in rack 22 constituting the rack row, for example, by multiplying the sum of the currents of each power cable supplying power to the information processing equipment by the voltage. Essentially, all of the power consumed by the information processing equipment in rack 22 is converted into thermal energy and dissipated from the surfaces of the electronic components. Therefore, it can be said that the power consumption of the information processing equipment has a specific relationship with the intake temperature and the amount of heat generated by the processing load related to information processing. Therefore, the power consumption of the information processing equipment is useful information for determining the optimal operating settings of each air conditioning device.

[0037] In the process of step S2, the central controller searches for various combinations of air conditioning conditions, and calculates the results (e.g., expected hot aisle temperature, power consumption of the air conditioning equipment, etc.) when each air conditioning equipment of the air conditioning system 1 operates under each combination based on the power consumption of the information processing equipment and characteristic data of the air conditioning equipment. Examples of combinations of air conditioning conditions include the following. That is, for example, for the supply air temperature, a stepwise assumption within a predetermined temperature range can be made (e.g., 20 to 25°C in increments of 0.2°C). For example, for the supply air volume, a stepwise assumption within a predetermined air volume range can be made (e.g., 20 to 100% in increments of 2%). For example, for the supply water temperature, a stepwise assumption within a range from the lower limit to the upper limit of the chilled water temperature that the heat source unit 12 can supply can be made (e.g., 13 to 17°C in increments of 0.5°C). For example, for the temperature of the outside air introduced from the outside air inlet 15, a stepwise assumption within a range from the lower limit to the upper limit of the outside temperature expected in the area where the building is located can be made. (For example, 0 to 26°C in 2°C increments). The central controller calculates the results when the air conditioning system 1 is operated under each of these various combinations of air conditioning conditions.

[0038] In step S3, the central controller compares the calculation results of step S2 with the conditions (conditions to be satisfied and constraints), comprehensively searches for air conditioning conditions that meet the conditions, and narrows down the optimal air conditioning conditions. The conditions to be satisfied are essential conditions required of the air conditioning system 1, such as an upper limit on the expected hot aisle temperature. Constraints are arbitrary conditions that can be changed as needed, such as priorities given by the administrator operating the air conditioning system 1. Examples of constraints include "maximizing the expected hot aisle temperature," "minimizing the supply air volume (fan power consumption)," "keeping the temperature deviation in each cold aisle section below a specified value," and "keeping the temperature deviation in each hot aisle section below a specified value."

[0039] In the processing of step S4, the central controller extracts the air conditioning conditions narrowed down in step S3 as operation set values ​​for each air conditioning device. That is, the central controller instructs (sends a control signal to) the controllers provided in each air conditioning device of the air conditioning system 1 to set operation set values ​​so that the control parameters (supply air temperature, supply air volume, supply water temperature, etc.) of each part of the air conditioning system 1 become parameters in the air conditioning conditions narrowed down in the processing of step S3.

[0040] The above is an overview of the processing executed by the central controller. Figure 4 is a diagram that supplements the above series of processing details. In the case of a data center where racks 22 containing information processing equipment are lined up, the power consumption of the entire air conditioning system 1 can normally be reduced as much as possible by operating the air conditioning system 1 so that the temperature of the hot aisle 21 is maximized within the allowable range required to cool the information processing equipment. Therefore, Figure 4 is an image diagram that assumes that the constraint condition in step S3 is set to "maximize the expected hot aisle temperature."

[0041] In the example shown in Figure 4, the estimated hot aisle temperature is calculated in 0.5°C increments within a range of 20.0°C to 27.0°C when the supply water temperature is 16°C and the supply air volume is 60% of the rated air volume. Figure 4 also shows the results of comparison with various constraints. As can be seen from Figure 4, if the supply air temperature is increased while the supply water temperature and supply air volume are kept constant, the estimated hot aisle temperature also increases. For example, if the upper limit for the hot aisle temperature is set to 32°C as a condition for fulfillment, the air conditioning condition is fulfilled if the estimated hot aisle temperature is lower than this value. Note that Figure 4 only illustrates some conditions, but similar calculations are performed for various conditions, such as when the supply water temperature is other than 16.0°C or when the supply air volume is other than 60% of the rated air volume. For example, the supply air volume is calculated in 5% increments within a range of 20% to 100% of the rated air volume.

[0042] In the example shown in Figure 4, the central controller of air conditioning system 1 extracts, from among the air conditioning conditions that satisfy the constraint "maximize the expected hot aisle temperature," the following air conditioning conditions: a water supply temperature of 16°C, an intake air volume of 60% of the rated volume, and an intake air temperature of 27.0°C. The operation setpoints indicated by these air conditioning conditions are sent from the central controller to the controllers of each air conditioner, so that the entire air conditioning system 1 operates in a state that cools the information processing equipment housed in rack 22 neither excessively nor insufficiently. By performing this calculation process for each zone of each air conditioning unit 11, the air conditioning system 1 operates at a capacity that matches the heat generation of the information processing equipment housed in rack 22, minimizing the power consumption of the air conditioning system 1.

[0043] The central controller of the air conditioning system 1 repeatedly executes the above series of processes shown in steps S1 to S4, for example, every 10 minutes. Therefore, the air conditioning system 1 can continue to cool the information processing devices almost without excess or deficiency, except in cases where the amount of heat generated by the information processing devices housed in the rack 22 suddenly changes. The central controller of the air conditioning system 1 The cycle for repeatedly executing steps S1 to S4 is not limited to every 10 minutes, and may be changed as appropriate depending on the content of the processing performed by the information processing device, the scale of the data center, etc. Furthermore, the central controller of the air conditioning system 1 may execute the processing of steps S2 to S4 when it detects in step S1 that the power consumption of the information processing device has fluctuated to or exceeds a predetermined value.

[0044] The processing executed by the central controller will be described in detail below. Fig. 5 is a flowchart showing the processing executed before the air conditioning system 1 starts operating. Fig. 6 is a flowchart showing the processing executed after the air conditioning system 1 starts operating. The processing executed by the central controller will be described in detail with reference to the flowcharts of Figs. 5 and 6.

[0045] <Processing before operation starts> To realize the processing of steps S1 to S4 above in the central controller of the air conditioning system 1, it is necessary to create an operation design sheet based on the characteristics of each air conditioning device and to define the rules necessary for optimizing the air conditioning system 1. Therefore, in the air conditioning system 1, before operation begins, the following pre-processing is performed as shown in the flowchart in Figure 5.

[0046] That is, first, data relating to the characteristics of each air conditioning device that constitutes the air conditioning system 1 is registered (S101). Fig. 7 is an image diagram of data relating to the characteristics of each air conditioning device that constitutes the air conditioning system 1. In the graph of Fig. 7, the horizontal axis represents the capacity of the device, such as the amount of heat produced, flow rate, and air volume, and the vertical axis represents the individual COP (Coefficient of Performance) and power consumption. In the case of the heat source device 12, the COP varies greatly depending on the outside temperature, so there is a characteristic graph showing the relationship between the COP and the amount of heat produced for each outside temperature.

[0047] Next, an operation design sheet for each operating condition of the air conditioning system 1 is created (S102). This operation design sheet calculates the relationship between the amount of heat produced and one or more evaluation items to be optimized, such as the system COP and power consumption of the air conditioning system 1, and defines various parameters such as chilled water temperature and cooling water temperature. FIG. 8 shows an example of the results of creating an operation design sheet. For example, FIG. 8 shows the relationship between the amount of heat produced and the system COP for each temperature of chilled water produced by the heat source unit 12 when the outdoor air intake rate is 20% and the outdoor temperature is 10°C. By creating various operation design sheets with alternating operating conditions in advance based on the characteristic data of each air conditioning device and storing them in a database, the central controller of the air conditioning system 1 can determine the expected hot aisle temperature, power consumption, etc. when the air conditioning system 1 is operated according to the specified air conditioning conditions.

[0048] Next, a basic rule base necessary for optimizing the operation of the air conditioning system 1 is constructed (S103). The basic rule base defines calculation rules and control rules for various parameters related to the air conditioning system 1, such as the amount of heat produced by the heat source equipment, the number of pumps in operation, the amount of heat processed by the air conditioners, the amount of humidification, and whether or not outdoor air cooling is possible. By setting basic rules for operating the air conditioning system 1, it becomes possible to optimize the number of operating air conditioners and the start / stop frequency, even if the air conditioning conditions of the air conditioning system 1 change in various ways. The central controller of the air conditioning system 1 extracts optimal operating conditions using a search engine and rule base, and can therefore be considered a type of artificial intelligence.

[0049] The central controller of the air conditioning system 1 realizes the operation of the air conditioning system 1 as described below by referring to the data and rules created by the processing of steps S101 to S103 above and stored in the storage device.

[0050] <Processing after operation starts> When the operation of the data center in which the air conditioning system 1 is installed starts, the central controller of the air conditioning system 1 executes the following processing (optimization control) shown in the flowchart of FIG.

[0051] That is, the central controller selects an item to be optimized from among the evaluation items related to the air conditioning system 1 (S201). As described above, the evaluation items related to the air conditioning system 1 include several items such as the system COP and power consumption of the air conditioning system 1, but for data center managers, the power consumption of the air conditioning system 1 is one of the evaluation items that they are most interested in. Therefore, the evaluation item selected in this step may be an item determined by a selection operation by the manager of the air conditioning system 1, or may be a predetermined item.

[0052] Next, the central controller refers to measurement data from sensors such as outdoor temperature, room temperature, and humidity provided in the air conditioning system 1 to grasp conditions related to the outdoor air and indoor loads (S202). The central controller then calculates an air state point based on the referenced measurement data (S203). By calculating the air state point from the referenced measurement data, the central controller identifies the location of the air state point on the psychrometric chart. The central controller then evaluates the indoor environment based on the calculated air state point (S204). FIG. 9 is a diagram showing an example of an indoor environment evaluation result. The grayscale range in FIG. 9 indicates an area where the indoor environment is acceptable. If the air state point calculated based on the measurement data is within the acceptable area, as shown in FIG. 9, for example, the central controller determines that the indoor environment is good. If the air state point calculated based on the measurement data is outside the acceptable area, the central controller determines that the indoor environment is poor.

[0053] Next, the central controller refers to data from the thermometers, flow meters, controllers, etc. of each air conditioning device provided in the air conditioning system 1 to grasp the operating status of the air conditioning equipment (S205). The central controller also obtains the power consumption of the information processing devices housed in each row of the rack 22 from ammeters, etc., to grasp the status of the information processing devices (S206). Then, the central controller performs processing to identify the optimal operating conditions for the air conditioning system 1 (S207).

[0054] Figure 10 is a diagram illustrating the process of identifying optimal operating conditions. The central controller calculates the heat quantity of the air conditioning load that the air conditioning system 1 must process based on the power consumption of the information processing equipment and the amount of outside air introduced. The central controller then searches for various air conditioning conditions using characteristic data for each air conditioning device, such as the heat source unit, pump, and fan, and narrows down the searched air conditioning conditions to those that meet the establishment conditions and constraints based on whether the expected air state point is within a range that does not cause problems for the indoor environment.

[0055] The central controller outputs the control parameters (supply air volume, supply air temperature, humidity, etc.) of each air conditioning device under the optimal operating conditions identified by this processing as operation set values ​​to each air conditioning device (S208). By updating the operation set values ​​of each air conditioning device to these control parameters, the entire air conditioning system 1 will be in an operating state that matches the power consumption of the information processing device. The central controller repeatedly executes the series of processes from steps S201 to S208 until, for example, a request to stop optimization control is made (S209). Requests to stop optimization control can be made for various reasons, such as a shutdown of the air conditioning system 1, an operation by the administrator of the air conditioning system 1 to stop optimization control, or a forced start of operation of the air conditioning system 1 due to a malfunction of some air conditioning devices.

[0056] Incidentally, the power consumption of the air conditioning system 1 is considered to be one of the evaluation items of greatest interest to the manager of the data center. The condition is the air conditioning condition when the temperature of the hot aisle 21 is the highest among various air conditioning conditions that satisfy the establishment conditions and constraints. Although the information processing equipment room 2 is shown simply in FIGS. 1 and 2, the actual configuration of the information processing equipment room 2 is more complex, and the temperature of the hot aisle 21 and the correspondence between the hot aisle 21 and the air conditioning unit 11 vary widely. For example, in some data centers, one rack row is made up of approximately 10 to 15 racks, while in others, one rack row is made up of approximately 10 to 20 racks. Some data centers have only a few rack rows, while others have several dozen rack rows. A zone that is conditioned by one air conditioning unit may have only one or two rack rows, or it may have three or more rack rows. These variations depend on the spacing between the pillars that make up the building, the relative positions of the pillars and the racks, the size of the air conditioning unit, and other factors. Therefore, when performing the above-mentioned optimization control, the central controller of the air conditioning system 1 performs optimization using the following logic.

[0057] Figure 11 is a conceptual diagram of the calculation flow in optimization control. The correspondence between the information processing equipment cooled by the air conditioning unit 11 is largely determined by the relative positions of the air conditioning unit 11 and the racks. Therefore, in the logic for identifying the optimal operating conditions for the air conditioning system 1, the various elements related to the air conditioning system 1 are organized into three categories: the system related to the information processing equipment (hereinafter, the "server system"), the system related to the air conditioning unit 11 (hereinafter, the "air conditioning system"), and the system related to the heat source unit 12 (hereinafter, the "heat source system"), as shown in Figure 11. The dominant control parameters for optimizing the overall operation of the air conditioning system 1—the "supply air temperature," "reference supply air volume," and "chilled water outlet temperature"—are defined as "optimization variable 1," "optimization variable 2," and "optimization variable 3," respectively. For each hypothetical operating condition in which these values ​​are alternated, the operating condition that minimizes the overall power consumption of the air conditioning system 1 is identified. The "supply air temperature" refers to the temperature of the supply air blown out of the air conditioning unit 11. Furthermore, the "reference supply air volume" is the volume of supply air blown out from the air conditioning unit 11. Furthermore, the "chilled water outlet temperature" is the temperature of the chilled water flowing from the heat source equipment 12 to the air conditioning coil 17. The central controller of the air conditioning system 1 handles these three control parameters as variables to be identified in optimization control, and performs calculations for each rack row and each zone to identify the operation set values ​​of each air conditioning unit 11 and each heat source equipment 12. The identified operation set values ​​are then set in the controller of each air conditioning equipment, thereby enabling the entire air conditioning system 1 to achieve feedforward control according to the heat generation amount of the information processing equipment.

[0058] According to the air conditioning system 1, as described above, the operational settings of each air conditioning device are determined using the power consumption of the information processing device. Therefore, various control target values ​​of the air conditioning system 1 are set to appropriate values, enabling the air conditioning system 1 to operate in a state commensurate with the power consumption of the information processing device. Setting the control target value of the supply airflow rate appropriately in accordance with the state of the information processing device in this manner reduces the airflow power required by reducing the pressure difference between the cold aisle and the hot aisle, and improves heat removal efficiency by increasing the temperature difference between the cold aisle and the hot aisle. Therefore, the power consumption of the air conditioning system 1 is minimized compared to operating the air conditioning system 1 with an excessively low temperature for the supply air to the cold aisle 23, an excessively low temperature for the chilled water to the air conditioning coil 17, or an excessively high volume of supply air blown from the air conditioning unit 11, even when the amount of calculation performed by the information processing device is low and the air conditioning load to be processed by the air conditioning system 1 is small.

[0059] Although the above embodiment has been described as being applied to a data center, the air conditioning system 1 can also be applied to places other than data centers, as long as the heat value of a heat source present in the space to be air-conditioned can be obtained directly from the heat source or indirectly from equipment connected to the heat source. For example, the air conditioning system 1 can be applied to factories where various machines such as semiconductor manufacturing equipment are in operation. The heat value of such machines can be obtained, for example, from the power consumption and operation of the machines. Since it is possible to grasp the operating conditions, it is suitable as an application location for the air conditioning system 1.

[0060] Furthermore, in the above embodiment, the operating conditions were specified to minimize the power consumption of the air conditioning system 1, but it is also possible to specify, for example, an operating state that minimizes the power consumption of the entire data center including the information processing equipment and the air conditioning system 1, and determine the operating setting values ​​of each air conditioning device.

[0061] Furthermore, in the above embodiment, the operating conditions were specified to minimize the power consumption of the entire air conditioning system 1 including the heat source unit 12, but when using a natural energy cold source such as well water or cold water from a river, for example, it is also possible to specify operating conditions to minimize the power consumption of the entire air conditioning system excluding the heat source unit.

[0062] Furthermore, in the above embodiment, feedforward control was performed based on the actual measured value of the power consumption of the information processing device, but for example, in cases where the processing to be performed by the information processing device is scheduled in advance, feedforward control may be performed based on the predicted value of the power consumption of the information processing device estimated from the schedule. [Explanation of symbols]

[0063] 1. Air conditioning system 2. Information Processing Equipment Room 11. Air conditioning unit 12...Heat source machine 13 Return air duct 14. Exhaust port 15. Fresh air intake 16. Blower fan 17··Air conditioning coil 18. Chilled water pump 21. Hot Aisle 22 racks 23 Cold Aisle

Claims

1. A control device for an air conditioning system that targets air conditioning of a space in which a heat source is located, a storage unit in which characteristic data of air conditioning equipment included in the air conditioning system is stored; a processing unit that determines a control target value of the air conditioning device based on the data in the storage unit, The processing unit a first process of acquiring a value correlated to the amount of heat generated by the heat source as an input value from the heat source or a device connected to the heat source; a second process in which, when the input value is acquired by the first process, a process of calculating a virtual temperature of the space when the air conditioning equipment is operated at a specific control target value from the input value and the characteristic data is performed for each of a plurality of virtual control target values ​​whose values ​​are staggered; and executing a third process of determining, as the control target value of the air conditioning equipment, a virtual control target value among the plurality of virtual control target values, such that the virtual temperature calculated by the second process satisfies a temperature condition specified for the space and the power consumption of the entire system including at least the air conditioning system is minimized. Air conditioning system control device.

2. the heat source is an information processing device, the air conditioning system is intended to air-condition a space in a data center where multiple rows of racks containing information processing equipment are arranged, The input value is the power consumption of the information processing device. The control device for an air conditioning system according to claim 1 .

3. the air conditioning system has a plurality of air conditioning units that blow out cool air to rack rows in which the racks are lined up, and the air conditioning units are positioned so as to correspond to one or more rack rows, The processing unit In the first process, the total power consumption of the information processing devices housed in the rack corresponding to the specific air conditioning unit is acquired for each air conditioning unit as the input value; In the second process, a process of calculating the virtual temperature when the air conditioning equipment including the air conditioning unit is operated at a specific control target value from the input value and the characteristic data is performed for each air conditioning unit for each of a plurality of virtual control target values ​​whose values ​​are staggered, the third process includes a process of determining the minimum virtual control target value as the control target value for each air conditioning unit, The control device for an air conditioning system according to claim 2 .

4. The virtual temperature includes the temperature of the space on the exhaust surface side of the rack. The control device for an air conditioning system according to claim 2 or 3.

5. the virtual control target value includes at least one of a temperature of supply air to be supplied to the space and a temperature of cold water that cools the air to be supplied to the space; The control device for an air conditioning system according to any one of claims 1 to 4.

6. The power consumption of the entire system is the power consumption of the entire air conditioning system or the power consumption of the entire air conditioning system combined with the heat source. The control device for an air conditioning system according to any one of claims 1 to 5.

7. The processing unit In the second process, the process of calculating the virtual temperature from the input value and the characteristic data is performed for each of the plurality of virtual control target values ​​whose values ​​are alternated by a predetermined difference. Do this The control device for an air conditioning system according to any one of claims 1 to 6.

8. The characteristic data is data representing a correlation between capacity and power consumption. The control device for an air conditioning system according to any one of claims 1 to 7.

9. A control device for an air conditioning system that targets air conditioning of a space in which a heat source is located, a first process of acquiring a value correlated to the amount of heat generated by the heat source as an input value from the heat source or a device connected to the heat source; a second process for calculating a virtual temperature of the space when the air conditioning equipment of the air conditioning system is operated at a specific control target value from the input value and characteristic data of the air conditioning equipment, the second process being performed for each of a plurality of virtual control target values ​​whose values ​​are staggered, when the input value is acquired by the first process; and executing a third process of determining, as the control target value of the air conditioning equipment, a virtual control target value among the plurality of virtual control target values, such that the virtual temperature calculated by the second process satisfies a temperature condition specified for the space and the power consumption of the entire system including at least the air conditioning system is minimized. How to control an air conditioning system.

10. The computer of the air conditioning system that targets the space where the heat source is located is a first process of acquiring a value correlated to the amount of heat generated by the heat source as an input value from the heat source or a device connected to the heat source; a second process for calculating a virtual temperature of the space when the air conditioning equipment of the air conditioning system is operated at a specific control target value from the input value and characteristic data of the air conditioning equipment, the second process being performed for each of a plurality of virtual control target values ​​whose values ​​are staggered, when the input value is acquired by the first process; and a third process of determining, as the control target value of the air conditioning equipment, a virtual control target value among the plurality of virtual control target values, such that the virtual temperature calculated by the second process satisfies a temperature condition specified for the space and the power consumption of the entire system including at least the air conditioning system is minimized. Air conditioning system control program.

11. An air conditioning system that conditions a space in which a heat source is located, Air conditioning equipment and a control device including a storage unit in which characteristic data of the air conditioning equipment is stored, and a processing unit that determines a control target value of the air conditioning equipment based on the data in the storage unit; The processing unit a first process of acquiring a value correlated to the amount of heat generated by the heat source as an input value from the heat source or a device connected to the heat source; a second process in which, when the input value is acquired by the first process, a process of calculating a virtual temperature of the space when the air conditioning equipment is operated at a specific control target value from the input value and the characteristic data is performed for each of a plurality of virtual control target values ​​whose values ​​are staggered; and executing a third process of determining, as the control target value of the air conditioning equipment, a virtual control target value among the plurality of virtual control target values, such that the virtual temperature calculated by the second process satisfies a temperature condition specified for the space and the power consumption of the entire system including at least the air conditioning system is minimized. Air conditioning system.

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