JP6982146B2 - Air conditioning system controls, control methods, control programs and air conditioning systems - Google Patents

Description

The present invention relates to a control device, a control method, a control program and an air conditioning system for an air conditioning system.

In recent years, computers have been used to control air conditioning systems (see, for example, Patent Documents 1 to 5 and Non-Patent Documents 1).

Japanese Unexamined Patent Publication No. 2005-257221 JP-A-2015-197236 Japanese Unexamined Patent Publication No. 2008-134013 Japanese Unexamined Patent Publication No. 2006-275397

Masanori Kurata, "Facilities Operation System Utilizing Artificial Intelligence (AI) / Wireless Sensors", Building Equipment and Plumbing, Nippon Kogyo Publishing Co., Ltd., May 5, 2016, Vol. 54, No. 6 (Vol. 726), p.35-39

In an air conditioning system equipped with a heat source unit such as a refrigerator, in order to maximize the COP (Coefficient Of Performance) of the entire system, after understanding the characteristics of the heat source unit and the cold heat production capacity, the outside air conditions and heat load, etc. It is necessary to control the operation of each device according to the situation. However, in an air conditioning system equipped with various devices such as a refrigerator, a cooling tower, and a pump, various control parameters such as the temperature and flow rate of cooling water, the air volume of the cooling tower fan, and the operating conditions of each device are complicatedly combined, which is enormous. It is not easy to continue to specify the operating conditions that maximize the COP of the entire system from among the calculation results while following the ever-changing outside air conditions and heat load.

Furthermore, the air conditioning system includes not only a new air conditioning system installed in a newly constructed building but also an existing air conditioning system installed in an existing building, and the efficiency of such an existing air conditioning system is also high. Although it is desirable to realize standard operation control, in the case of an existing air conditioning system, it may be difficult to install instruments for electronic control that are easy to install in the new air conditioning system, so the optimum operating conditions It may not be possible to obtain the information necessary to identify the system.

Therefore, the present application discloses a control technology for air conditioning that can maximize the COP of the entire air conditioning system based on a limited amount of information, such as information from instrumentation normally provided in an existing air conditioning system. do.

In order to solve the above problems, in the present invention, the chilled water temperature is estimated based on the information of the outside air and the heat load, and the estimated chilled water temperature can be produced based on the information of each device of the air conditioning system. I decided to estimate.

Specifically, it is a control device of an air conditioning system having a heat source unit and a cooling tower, and estimates the chilled water temperature at which the air conditioner can controlly satisfy the indoor conditions based on at least the information of the outside air and the heat load. Based on the information of each device of the air conditioning system, the cooling water temperature that reduces the energy consumption of the entire air conditioning system is estimated, the estimated cold water temperature is set as the control target value of the heat source machine, and the estimated cooling water temperature is cooled. Set to the control target value of the tower.

In the above control device, the heat source machine has a reasonable chilled water temperature estimated based on the information on the outside air that has an external effect on the room to be air-conditioned and the information on the heat load that represents the thermal state of the room. Since the control target value is set, the energy consumed by the heat source unit can be suppressed as compared with the case where the heat source unit is continuously operated at a constant cold water temperature regardless of changes in the outside air or the like. Since the control target value of the cooling water temperature is also set to a reasonable value, the energy consumption of the cooling tower can be suppressed as compared with the case where the cooling tower fan is continuously operated at the rated value, for example. As a result, the energy consumption of the entire air conditioning system is suppressed.

Further, in the above control device, each value is estimated based on the information of each device of the air conditioning system prepared in advance, so that the air conditioning system required when there is no information of each device prepared in advance. It is not necessary to acquire enormous process values for each part, and it is possible to reduce the energy consumption of the entire air conditioning system even with information from instruments that are normally provided in existing air conditioning systems.

In estimating the cold water temperature, a high value may be adopted as long as the air conditioner can control the indoor conditions. The higher the temperature of the cold water to be produced, the smaller the energy consumption of the heat source machine. Therefore, if such a cold water temperature is adopted as the control target value, the energy consumption of the entire air conditioning system will be suppressed.

In estimating the cooling water temperature, the energy consumption of the entire air conditioning system at each of several cooling water temperatures assuming that the estimated cold water temperature is within the range that the heat source machine can manufacture is calculated and the calculated energy. A cooling water temperature that reduces consumption may be adopted. If the cooling water temperature is estimated in this way, the amount of calculation required for the estimation is reduced as compared with the case where the calculation process is performed regardless of whether or not it is within the range of the cooling water temperature that can be cooled by the cooling tower, for example. be able to.

Further, the heat load information may be information on the operating state acquired from the heat source machine. The heat processed by the air conditioner is basically transferred to the cooling tower via the heat source machine. Therefore, if the information on the heat load processed by the air conditioning system is acquired from the heat source machine, the information can be easily acquired.

The present invention can also be grasped from the aspect of the method. For example, the present invention is a control method for an air conditioning system having a heat source unit and a cooling tower, and estimates the cold water temperature at which the air conditioner can control indoor conditions based on at least information on outside air and heat load. Then, based on the information of each device of the air conditioning system, the cooling water temperature that reduces the energy consumption of the entire air conditioning system is estimated, the estimated cold water temperature is set as the control target value of the heat source machine, and the estimated cooling water temperature. May be set to the control target value of the cooling tower.

The present invention can also be understood from the aspect of a program that can be executed by a computer. For example, the present invention is a control program for an air conditioning system having a heat source unit and a cooling tower, wherein the air conditioning system controls the indoor conditions based on at least information on the outside air and heat load in the control device of the air conditioning system. The process of estimating the chilled water temperature that can be used, the process of estimating the cooling water temperature that reduces the energy consumption of the entire air conditioning system based on the information of each device of the air conditioning system, and the control of the estimated chilled water temperature of the heat source machine. The process of setting the target value and the process of setting the estimated cooling water temperature as the control target value of the cooling tower may be executed.

The present invention can also be grasped from the aspect of the system. For example, the present invention includes a heat source unit, a cooling tower, and a control device, and the control device is cold water in which an air conditioner can control indoor conditions based on at least information on outside air and heat load. Estimate the temperature, estimate the cooling water temperature that reduces the energy consumption of the entire air conditioning system based on the information of each device of the air conditioning system, set the estimated cold water temperature as the control target value of the heat source machine, and estimate it. It may be an air conditioning system that sets the cooling water temperature to the control target value of the cooling tower.

In the case of the above-mentioned air-conditioning system control device, control method, control program, and air-conditioning system, the air-conditioning system is based on a limited amount of information, such as information from instruments normally provided in existing air-conditioning systems. The overall COP can be maximized.

FIG. 1 is a diagram showing an example of an air conditioning system. FIG. 2 is an image of an outline of the control performed by the central controller. FIG. 3 is a flowchart of control performed by the central controller. FIG. 4 is a first diagram illustrating an inference flow of the refrigerator chilled water outlet temperature by the central controller. FIG. 5 is a diagram showing an example of a psychrometric chart. FIG. 6 is an example of a table for determining the refrigerator chilled water outlet temperature based on the calculated change amount of the chiller chilled water outlet temperature. FIG. 7 is a second diagram illustrating an inference flow of the refrigerator chilled water outlet temperature by the central controller. FIG. 8 is a diagram illustrating items used for inferring the cooling tower and the cooling water temperature. FIG. 9 is a graph illustrating the range of the cooling water outlet temperature based on the outside air wet-bulb temperature and the approach temperature. FIG. 10 is a flowchart illustrating the flow of the inference processing of the cooling water temperature. FIG. 11 is a diagram illustrating the calculation of the power consumption of the refrigerator for each operating condition. FIG. 12 is a diagram illustrating the calculation of the power consumption of the auxiliary machine for each load factor of the refrigerator. FIG. 13 is a diagram illustrating complementation of performance characteristic data. FIG. 14 is a diagram illustrating the operation priority of the refrigerator. FIG. 15 is a diagram illustrating an operation design sheet. FIG. 16 is a graph illustrating an increase in the number of heat source operations. FIG. 17 is a graph showing an example of the correlation between the load factor of the entire heat source and the COP of the entire system. FIG. 18 is a flowchart illustrating a process of creating an operation design sheet.

Hereinafter, embodiments of the present invention will be described. The embodiments shown below are examples of embodiments of the present invention, and the technical scope of the present invention is not limited to the following embodiments.

FIG. 1 is a diagram showing an example of an air conditioning system. As shown in FIG. 1, the air conditioning system 1 includes an air conditioner 10 through which air in the room 4 passes, a refrigerator 20 for cooling cold water sent to the air conditioner 10, (an example of a "heat source machine" in the present application), and an air conditioner. A cooling tower 30 for cooling the cooling water for cooling the 10 by the principle of heat of vaporization is provided. The air conditioner 10 has a built-in coil 11 through which cold water passes through the pipe and an electric fan 12 controlled by an inverter, and sends temperature-controlled air to the room 4 when passing through the coil 11. The cold water passing through the coil 11 of the air conditioner 10 is carried by the cold water circulation system 40 forming a circulation path of the cold water between the air conditioner 10 and the refrigerator 20. Further, the cooling water that cools the refrigerator 20 is carried by the cooling water circulation system 50 that forms a cooling water circulation path between the cooling tower 30 and the refrigerator 20. In FIG. 1, one air conditioner 10, two cooling towers 30, and two refrigerators 20 are shown, but the number of air conditioners 10, the cooling tower 30, and the refrigerator 20 is the number of indoors 4. It is appropriately determined based on the size, the amount of heat generated in the room 4, the climate of the area where the air conditioning system 1 is installed, and various other design factors.

The air conditioner 10 is provided with an air conditioner controller 14. The air conditioner controller 14 includes control information sent from the host device via the network 2, a set temperature input through the operation panel of the room 4, and a temperature sensor and a humidity sensor installed in the return air (RA) path from the room 4. Information, and information on the temperature sensor and humidity sensor installed in the room 4 are input. Based on this information, the air conditioner controller 14 adjusts the opening degree of the air conditioner chilled water flow rate adjusting valve 13 for adjusting the flow rate of chilled water passing through the coil 11 and the rotation speed of the electric fan 12. The air conditioner controller 14 not only has a function of outputting control signals of the air conditioner chilled water flow rate adjusting valve 13 and the electric fan 12, but also has various information such as a measured value of a temperature sensor and an operating state of the electric fan 12. It also has a function of transmitting to the device.

The chilled water circulation system 40 includes a chilled water primary pump 41 installed on the inlet side of the refrigerator 20 and a chilled water secondary pump 42 installed on the inlet side of a header for branching cold water to each air conditioner 10. , Cold water is forcibly circulated by the cold water primary pump 41 and the cold water secondary pump 42. The cold water primary pump 41 is a turbo pump installed for the purpose of ensuring the flow velocity of cold water passing through the pipe side of the evaporator of the refrigerator 20, and is driven by an inverter-controlled motor whose rotation speed can be changed. One cold water primary pump 41 is prepared for one refrigerator 20. Therefore, the cold water circulation system 40 is provided with the same number of cold water primary pumps 41 as the refrigerator 20. The cold water secondary pump 42 is a turbo pump installed for the purpose of ensuring the flow velocity of cold water passing through the pipe of the coil 11 of the air conditioner 10, and like the cold water primary pump 41, it has an inverter control that can change the rotation speed. It is driven by a motor. The number of cold water secondary pumps 42 provided in the cold water circulation system 40 is determined according to the capacity of a single pump, the number and size of air conditioners 10, and the like.

The cold water secondary pump 42 is provided with a secondary pump controller 44. The control information sent from the host device via the network 2 and the information of the flow rate sensor and the temperature sensor provided in each part of the cold water circulation system 40 are input to the secondary pump controller 44. Based on this information, the secondary pump controller 44 determines the operating number and rotation speed of the cold water secondary pump 42, and the opening degree of the minimum flow valve 43 in the path connecting the outlet side to the inlet side of the cold water secondary pump 42. adjust. Further, the secondary pump controller 44 also has a function of transmitting various information such as the measured value of the flow rate sensor and the operating state of the cold water secondary pump 42 to the host device.

The cooling water circulation system 50 includes a cooling water circulation pump 51 installed on the inlet side of the refrigerator 20, and the cooling water circulation pump 51 forcibly circulates the cooling water. The cooling water circulation pump 51 is a turbo pump installed for the purpose of ensuring the flow velocity of the cooling water passing through the pipe side of the condenser of the refrigerator 20, and is driven by an inverter-controlled motor whose rotation speed can be changed. One cooling water circulation pump 51 is prepared for one refrigerator 20. Therefore, the cooling water circulation system 50 is provided with the same number of cooling water circulation pumps 51 as the refrigerator 20. Since the ball tap type make-up water valve for maintaining the water level of the cooling water is provided inside the cooling tower 30, the suction pressure of the cooling water circulation pump 51 is kept substantially constant.

The refrigerator 20 is provided with a heat source controller 21. The heat source controller 21 has control information sent from the host device via the network 2, information on a flow sensor that measures the flow rate of cooling water and cold water passing through the refrigerator 20, and temperature for measuring the temperature of cooling water and cold water passing through the refrigerator 20. Sensor information is input. Based on this information, the heat source controller 21 adjusts the rotation speed of the cooling water circulation pump 51, the rotation speed of the cold water primary pump 41, the rotation speed of the compressor that influences the capacity of the refrigerator 20, and the vane opening. .. Further, the heat source controller 21 transfers various information such as the measured value of the temperature sensor, the measured value of the flow rate sensor, the operating state of the cooling water circulation pump 51, the operating state of the cold water primary pump 41, and the operating state of the refrigerator 20 to the higher-level device. It also has a function to send.

The cooling tower 30 is provided with a cooling tower controller 32. The cooling tower controller 32 has control information sent from the host device via the network 2, information on a temperature sensor that measures the temperature of the outside air, information on a humidity sensor that measures the humidity of the outside air, and the temperature of the cooling water on the outlet side of the cooling tower 30. The information of the temperature sensor to measure is input. Based on this information, the cooling tower controller 32 adjusts the rotation speed of the motor that drives the cooling tower fan 31 provided in the cooling tower 30. Further, the cooling tower controller 32 also has a function of transmitting various information such as measured values of the temperature sensor and the humidity sensor and the operating state of the cooling tower fan 31 to the host device.

In the air conditioning system 1 configured as described above, the following controls are basically performed during the cooling operation. That is, the air conditioner controller 14 increases the opening degree of the air conditioner chilled water flow rate adjusting valve 13 when the temperature of the room 4 is higher than the set temperature, and increases the opening degree of the air conditioner chilled water flow rate adjusting valve 13 when the temperature of the room 4 is lower than the set temperature. Reduce the opening. Further, in the heat source controller 21, the temperature of the chilled water on the outlet side of the chiller 20 (hereinafter, referred to as “refrigerator chilled water outlet temperature” and may be simply referred to as “cold water temperature”) is a predetermined control target value (for example, 7). Adjust the capacity of the refrigerator 20 so that it is kept at ° C). Further, in the cooling tower controller 32, the temperature of the cooling water on the outlet side of the cooling tower 30 (hereinafter, referred to as “cooling tower cooling water outlet temperature” and may be simply referred to as “cooling water temperature”) is the same as that of the refrigerator 20. The cooling tower fan 31 is rotated so that the condenser is below a predetermined set temperature at which the condenser can exert its condensing capacity. Since each controller basically performs such control, even if the amount of heat transported by the cold water or the cooling water changes due to a sudden change in the thermal environment of the room 4, the temperature of the room 4 is the air conditioner. The temperature of the chilled water outlet of the chiller is kept substantially constant by the chiller 20, and the temperature of the chilled water outlet of the chiller is kept within a range that does not interfere with the operation of the chiller 20, and the entire system is stable. Good driving is maintained.

The basic control contents of the air conditioning system 1 are as described above. In the air conditioning system 1 of the present embodiment, GDoc (GDoc is Takasago Thermal Engineering Co., Ltd.), which is a higher-level device for maximizing the COP of the entire system. Since it is a registered trademark of the company, it is provided with (hereinafter referred to as "central controller") 3 for convenience. The central controller 3 takes in the minimum parameters required for control by a general refrigerator, cooling tower, and air conditioner as input points, and based on those minimum required information, the COP of the entire system is maximum. The control target value of each device is calculated, and the calculated control target value is set in the controller of each device. Therefore, the central controller 3 can be attached not only to the newly installed air-conditioning equipment installed in the newly constructed building but also to the existing air-conditioning equipment. Here, the power consumption considered in the calculation of the COP of the entire air conditioning system is the power of the cooling water circulation pump 51, the power of the cooling tower fan 31, the power consumption of the refrigerator 20, and the power of the cold water primary pump 41. Maximizing the COP of the entire system corresponds to minimizing the total value of these power and power consumption. Needless to say, the power of the cold water secondary pump 42 may be included.

FIG. 2 is an image of an outline of the control performed by the central controller 3. The central controller 3 is a computer having a CPU (Central Processing Unit), a memory, an input / output interface, and the like, and controls the entire air conditioning system 1 by executing a computer program. That is, when the central controller 3 executes a computer program, for example, in real time (every 10 minutes), outside air conditions (outside air temperature and humidity), indoor conditions (indoor temperature and humidity), and heat source load conditions (manufacturing of a refrigerator). The operating status and device specificity of each air-conditioning device such as the refrigerator 20, auxiliary equipment (cooling water pump, cold water pump, etc.), and air-conditioner 10 created in advance by acquiring the values such as (calorific value, etc.) from the controller of each device. The characteristic data showing the correlation with the COP of the above is read out, and the optimization process of the control target value of each device is executed according to a predetermined rule engine. Then, the central controller 3 outputs the control target value of each device that has been optimized so that the COP of the entire air conditioning system 1 is maximized to the controller of each device. The controller of each device adjusts the control amount so that the parameter to be controlled becomes a new control target value that has been optimized. The controller of each device adjusts the control amount toward the optimized control target value, and as a result, the COP of the entire air conditioning system 1 is maximized.

FIG. 3 is a flowchart of control performed by the central controller 3. When the central controller 3 executes a computer program, it reads a setting file (information such as the type and number of devices provided in the air conditioning system 1) stored in a recording medium such as a hard disk (S101). Next, the central controller 3 acquires values such as the outside air condition measured by the cooling tower controller 32, the indoor condition measured by the air conditioner controller 14, the heat source load condition used by the heat source controller 21, and the like from each controller. (S102). Next, the central controller 3 infers the refrigerator chilled water outlet temperature (heat source chilled water temperature) (S103). Further, the central controller 3 infers the cooling water outlet temperature (cooling water temperature) of the cooling tower (S104). Further, the central controller 3 infers the operating number (heat source operating number) of the refrigerator 20 (S105). Further, the central controller 3 outputs the refrigerator chilled water outlet temperature inferred in the process of step S103 and the operating number of the chiller 20 inferred in the process of step S105 to the heat source controller 21, and the cooling tower inferred in the process of step S104. The cooling water outlet temperature is output to the cooling tower controller 32 (S106). Next, the central controller 3 determines whether or not the air conditioning system 1 is stopped, stops the control of the air conditioning system 1 when a positive determination is made, and steps when a negative determination is made. The processing after S102 is executed again (S107).

The details of each inference process will be described below.

<Step S103>
In step S103, the central controller 3 infers the refrigerator chilled water outlet temperature as described above. In this inference, when the central controller 3 cannot acquire the indoor conditions, the central controller 3 infers the refrigerator chilled water outlet temperature based on the virtual indoor design conditions and the virtual air conditioner design. Further, when the information on the indoor temperature and the relative humidity can be acquired, the central controller 3 infers the refrigerator chilled water outlet temperature based on the change state of the indoor temperature and the relative humidity. In the inference of step S103, the central controller 3 determines the necessity of dehumidifying the outside air. When it is not necessary to dehumidify the outside air and it is determined that the air conditioning load is small, the air conditioner 10 can ignore the latent heat load in the room, so it is sufficient if the sensible heat load in the room can be treated. Therefore, the central controller 3 optimizes the temperature of the chilled water outlet of the refrigerator by determining the operating conditions of the air conditioner 10 capable of processing the sensible heat load in the room. By optimizing the temperature of the chilled water outlet of the chiller, the operating efficiency of the chiller 20 is improved, and the COP of the entire air conditioning system 1 can be expected to be improved. The central controller 3 performs the inference processing in step S103 in real time (for example, every 10 minutes). When estimating the cooling water temperature in step S104, the central controller 3 selects the cooling water temperature that minimizes the total power consumption based on the estimated cooling water temperature.

(When indoor conditions cannot be obtained)
FIG. 4 is a first diagram illustrating an inference flow of the refrigerator chilled water outlet temperature by the central controller 3. FIG. 4 illustrates a processing flow for inferring the temperature of the chilled water outlet of the refrigerator by the central controller 3 when the indoor conditions cannot be obtained. FIG. 4 is a diagram showing an example of details of the process of step S103 of FIG. Hereinafter, with reference to FIG. 4, a processing flow for inferring the temperature of the chilled water outlet of the refrigerator by the central controller 3 when the indoor conditions cannot be obtained will be described.

In step S201, the central controller 3 determines whether or not the outside air needs to be dehumidified. In the determination in step S201, the central controller 3 refers to the heat source load condition acquired from the heat source controller 21 and the outside air condition acquired from the cooling tower controller 32. The central controller 3 further refers to the design information of the virtual air conditioner determined based on the heat source design. The central controller 3 controls the indoor temperature and relative humidity set as control target values based on the heat source load condition, the outside air condition, and the capacity of the virtual air conditioner. The room temperature and relative humidity set as control target values are referred to as virtual room design conditions in the present specification.

(Determination of design information for virtual air conditioners)
The central controller 3 uses coil inlet water temperature t _w1 , coil outlet water temperature t _w2 , coil water flow amount L, coil water flow heat amount q _w , coil inlet air temperature t _a1 , and coil outlet air temperature t _{a2 as design information for the virtual air conditioner.} And the air supply air volume G is determined as follows. The central controller 3 reads the setting file and reads the coil inlet water temperature t _w1 , the coil outlet water temperature t _w2 , the number of refrigerators 20, and the rated flow rate of the cold water secondary pump 42 of the coil 11 of the air conditioner 10 registered by the initial setting. get. Here, for example, the coil inlet water temperature t _w1 is 7 ° C., the coil outlet water temperature t _w2 12 ° C., the number of refrigerators 20 is 3, and the rated flow rate of the cold water secondary pump 42 is 4,030 L / min. And. Further, it is assumed that the air conditioning system 1 includes 100 virtual air conditioners.

The coil water flow amount L, which is the water flow amount of cold water flowing through the coil 11 per minute, is calculated by, for example, the following mathematical formula.

The coil 11 is passed based on the rated flow rate (4030 L / min) of the cold water secondary pump 42, the number of refrigerators 20 (3 units), and the number of virtual air conditioners (100 units) registered in the setting file at the time of initial setting. The water volume L is calculated to be 121 L / min. _{Further, the coil water passage heat amount q w} , which is the heat amount of the cold water flowing through the coil 11, is calculated by, for example, the following mathematical formula.

According to Equation 2, the coil water flow heat amount q _w is calculated to be 42.21 kW based on the coil outlet water temperature t _w2 , the coil inlet water temperature t _{w1, and the coil water flow amount L. The central controller 3 acquires the coil inlet air temperature t a1} which is the temperature of the air flowing into the _{coil 11 and the coil outlet air temperature t a 2} which is the temperature of the air flowing out of the coil 11 from the air conditioner controller 14. However,
When air has not yet flowed through the coil 11, as in the case of operating the air conditioning system 1, the initial setting values registered in the setting file as _{the coil inlet air temperature t a1} and the coil outlet air temperature t _{a2 are adopted.} Will be done. Here, for example, 2 is set as the _{coil inlet air temperature t a1.}
It is assumed that 6 ° C. and 17.5 ° C. are registered as the coil outlet air temperature t _a2. Moreover,
It is assumed that the relative humidity of the air flowing into the coil 11 is 50% RH.

FIG. 5 is a diagram showing an example of a psychrometric chart. In the air diagram, state values indicating various air conditions including absolute humidity, relative humidity, dry-bulb temperature, and wet-bulb temperature are entered, and two state values are selected from these to indicate the air state. It is a figure created so that can be grasped. The data related to the psychrometric chart illustrated in FIG. 5 is held, for example, in the memory of the central controller 3. Referring to the psychrometric chart of FIG. 5, the coil inlet air temperature _ta1 is 26 ° C. and the relative humidity is 50%.
When the RH air is cooled to 17.5 ° C, which is the coil outlet air temperature t _{a2, the relative humidity is 8.}
It can be seen that it is 5% RH. Based on such an assumption, the air supply air volume G of the virtual air conditioner is calculated by, for example, the following mathematical formula.

Cp in Equation 3 is the constant pressure specific heat of the dry air, and ρ is the density of the dry air. According to Equation 3, the air supply air volume G of the virtual air conditioner is calculated to be ^{15,291 m 3 / h.} Through the above processing, the central controller 3 can determine the design information of the virtual air conditioner.

(Virtual room design conditions)
Further, the central controller 3 determines the virtual room design conditions. In determining the virtual room design conditions, the temperature inside the room, which is the control target, is _{assumed to be the coil outlet air temperature t a2} described above, and the relative humidity inside the room is assumed to be 85% RH, which is the relative humidity of the coil outlet air.

With the above processing, the central controller 3 that has completed the design of the virtual air conditioner and the hypothetical processing of the virtual room design conditions makes the dehumidification determination in step S201. In this determination, the central controller 3 compares the absolute humidity of the outside air acquired from the heat source controller 21 of the cooling tower 30 with the absolute humidity of the room under the virtual room design conditions. First, the central controller 3 calculates the absolute humidity in the room from the measured values of the room temperature and humidity with reference to the psychrometric chart of FIG. The central controller 3 compares the calculated absolute humidity of the indoor air with the absolute humidity of the outside air. When the absolute humidity of the indoor air is larger than the absolute humidity of the outside air, the central controller 3 determines that dehumidification is unnecessary (dehumidification is unnecessary in S201), and the process proceeds to step S202. When the absolute humidity of the indoor air is equal to or higher than the absolute humidity of the outside air, the central controller 3 determines that dehumidification is necessary (dehumidification is necessary in S201), and the process proceeds to step S205.

When dehumidification of the outside air is not necessary in step S201, and when it is determined that the air conditioning load is small, the virtual air conditioner can ignore the latent heat load in the room, so that it is not necessary to process the latent heat load, and the sensible heat in the room is not required. It is only necessary to be able to handle the load. Therefore, in step S202, the central controller 3 calculates the refrigerator chilled water outlet temperature (in the figure, the chilled water temperature) capable of processing the sensible heat load in the room. The central controller 3 assumes the items described in 1 to 6 below in calculating the rational refrigerator chilled water outlet temperature at which the COP of the entire system is maximized.
1. 1. The amount of heat passed through the coil q _w and the amount of indoor heat load processing q _{a are equal.}
2. 2. The coil water flow amount L is equal to the measured value.
3. 3. The coil water inlet / outlet temperature difference (t _w2 −t _w1 ) is equal to the measured value.
4. The supply air volume G is reduced according to the load. The lower limit value α of the supply air volume G is 20% of the rated value. The lower limit value α of the air supply air volume G can be changed by changing the value registered in the setting file.
5. When the supply air volume G reaches the lower limit and the load is small, the coil inlet water temperature t _{w 1} is increased.
6. The upper limit of the coil inlet water temperature t _w1 is determined by the following equation 4.

_{CS Lim in} Equation 4 is the upper limit of the coil inlet temperature (° C), t'is the outside air wet-bulb temperature (° C), _tap is the cooling tower approach temperature (° C), and Δt _CDS-CS is the refrigerator cooling water inlet and cold water. The temperature difference (° C) at the outlet. Δt _CDS-CS is determined, for example, based on the capacity of the refrigerator 20, and in the present embodiment, it is 5 ° C.
It is supposed to be. In Equation 4, the cooling tower cooling water outlet temperature is calculated by the sum of the outside air wet-bulb temperature (t') and the cooling tower approach temperature (t _ap). Since the cooling water is supplied from the cooling tower 30 to the refrigerator 20, the cooling tower cooling water outlet temperature is equal to the refrigerator cooling water inlet temperature. Therefore, the central controller 3 has a coil inlet water temperature t _{w1 based on the temperature difference (Δt CDS-CS} ) between the refrigerator cooling water inlet and the chilled water outlet in consideration of the capacity of the refrigerator 20 with respect to the refrigerator cooling water inlet temperature. _{CS Lim} which is the upper limit
Can be decided. As the lower limit of the coil inlet water temperature t _w1 , for example, the value registered in the setting file at the time of initial setting can be adopted.

Based on the above assumptions, the refrigerator chilled water outlet temperature capable of processing the sensible heat load in the room is determined by, for example, the following equation 5.

In Equation _5, t w1new refrigerator coolant outlet temperature (coil inlet water temperature) to be calculated this time, t _w1 current refrigerator coolant outlet temperature (coil inlet water temperature), t _a1 coil inlet air temperature, t _a2 coil outlet The air temperature. Further, Δt ₁ is the minimum air volume temperature change indicating the temperature change of the air passing through the coil when the virtual air conditioner is operated at the minimum air volume α. That is, according to Equation 5, the coil inlet water temperature t _{w1 new} calculated this time is the value obtained by subtracting the _{minimum air volume temperature change Δt 1} from the temperature change of the air passing through the coil to the current coil inlet water temperature t w1. It is calculated by being done. The minimum air volume temperature change Δt ₁ is determined by, for example, the following equation 6.

In Equation 6, qw is the amount of heat passed through the coil, α is the minimum amount of air supplied by the virtual air conditioner, G is the amount of air supplied by the virtual air conditioner, ρ is the density of dry air, and Cp is the constant pressure specific heat of the dry air.

In step S203, the central controller 3 determines whether or not to change the refrigerator chilled water outlet temperature. In the determination of step S203, the central controller 3 determines the refrigerator chilled water based on the amount of change between the refrigerator chilled water outlet temperature calculated in the process of step S202 and the refrigerator chilled water outlet temperature calculated last time (for example, 10 minutes ago). Determine whether to change the outlet temperature. That is, when the calculated temperature of the chilled water tends to rise, the central controller 3 changes the set value of the memory of the chilled water outlet temperature of the refrigerator output to the heat source controller 21 in step S106 so that the temperature of the chilled water rises. Further, when the calculated temperature of the chilled water tends to decrease, the central controller 3 changes the set value of the memory of the chilled water outlet temperature of the refrigerator output to the heat source controller 21 in step S106 so that the temperature of the chilled water decreases. FIG. 6 is an example of a table for determining the refrigerator chilled water outlet temperature based on the calculated change amount of the chiller chilled water outlet temperature. In FIG. 6, the calculated change amount of the chilled water outlet temperature of the chiller, whether or not the chilled water outlet temperature of the chiller can be changed, and the determined chilled water outlet temperature of the chiller (cold water temperature in the figure) are associated with each other. _{T w1 new in} FIG. 6 is the refrigerator chilled water outlet temperature calculated this time. t _w1old is the refrigerator cold water outlet temperature calculated last time. For example, in FIG. 6, when _{the difference between t w1 new} and t w 1 old is minus 1.0 or more and less than minus 0.5 occurs twice in a row (in the case of No. 4 in FIG. 6), the central controller 3 _{Determines the temperature obtained by subtracting} 1.0 ° C from the previously calculated temperature (t w1old) of the chilled water outlet temperature of the chiller as the chilled water outlet temperature of the chiller. The table illustrated in FIG. 6 is held, for example, in the memory of the central controller 3. When changing the refrigerator chilled water outlet temperature (change permission in S203), the process proceeds to step S204. If the refrigerator chilled water outlet temperature is not changed (change not permitted in S203), the process proceeds to step S206.

In step S204, the central controller 3 changes the value of its own memory so that the temperature determined in step S202 is output to the heat source controller 21 as a new set value of the refrigerator chilled water outlet temperature in the process of step S106. do.

In step S205, the central controller 3 returns the set value of the refrigerator chilled water outlet temperature to the rated value (default value). That is, the central controller 3 has its own memory value so that the rated value of the refrigerator chilled water outlet temperature is output to the heat source controller 21 as a new set value of the refrigerator chilled water outlet temperature in the process of step S106. To change.

In step S206, the central controller 3 does not change the refrigerator chilled water outlet temperature.

When the indoor condition could not be acquired, the central controller 3 determined the design information of the virtual air conditioner, and determined the virtual indoor design condition based on the determined design information. The central controller 3 determines whether or not dehumidification of the outside air is necessary based on the virtual room design conditions and the outside air conditions acquired from the cooling tower controller 32. When it is not necessary to dehumidify the outside air and when it is determined that the air conditioning load is small, the latent heat load in the room can be ignored. Try to optimize. That is, the central controller 3 can set the refrigerator chilled water outlet temperature higher by the amount that does not process the latent heat load. By setting the temperature of the chilled water outlet of the chiller high, the operating efficiency of the chiller 20 can be improved. As a result, even if the central controller 3 cannot acquire the indoor conditions, the COP of the entire air conditioning system 1 can be expected to be improved.

(If indoor conditions can be obtained)
FIG. 7 is a second diagram illustrating an inference flow of the refrigerator chilled water outlet temperature by the central controller 3. FIG. 7 illustrates a processing flow for inferring the temperature of the chilled water outlet of the refrigerator by the central controller 3 when the indoor conditions can be acquired. FIG. 7 is a diagram showing an example of details of the process of step S103 of FIG. In the process of FIG. 7, the central controller 3 acquires information on the indoor temperature and relative humidity from the air conditioner controller 14. The central controller 3 determines whether or not to change the refrigerator chilled water outlet temperature according to the amount of change between the indoor temperature and relative humidity acquired this time and the indoor temperature and relative humidity acquired last time. The central controller 3 changes the memory setting value of the refrigerator chilled water outlet temperature output to the heat source controller 21 in step S106 so that the temperature of the chilled water decreases when the acquired indoor temperature or relative humidity tends to increase. do. Further, the central controller 3 sets a memory setting value of the refrigerator chilled water outlet temperature output to the heat source controller 21 in step S106 so that the temperature of the chilled water rises when the acquired indoor temperature or relative humidity tends to decrease. To change. Hereinafter, with reference to FIG. 7, a processing flow for inferring the temperature of the chilled water outlet of the refrigerator by the central controller 3 when indoor conditions can be obtained will be described.

In FIG. 7, n (n is an integer of 1 or more) is a number that identifies each room to be air-conditioned by the air-conditioning system 1. The central controller 3 repeatedly executes the processes from step S301 to step S307 for each room. In step S301, the central controller 3 adds 1 to the value of n.

In step S302, the central controller 3 determines whether or not the air conditioner 10 for the nth room is operating. If it is operating (YES in S302), the process proceeds to step S303. If it is not operating (NO in S302), the process is returned to step S301.

In step S303, the central controller 3 sets room temperature and relative humidity tolerances. The permissible range is determined, for example, by the following equations 7-14.

In equations 7 to 14, t _{RM_SP_LL} (n) is the second lower limit of the room temperature permissible in the nth room. t _{RM_SP} (n) is the set temperature set in the nth room. t% (n) is the temperature tolerance applied to the nth chamber. t _{RM_SP_L} (n) is the first lower limit of the allowable indoor temperature in the nth room. t _α is a correction value in an allowable range related to temperature, and the initial value is 0.5 in this embodiment. t _{RM_SP_H} (n) is the first upper limit of the room temperature permissible in the nth room. t _{RM_SP_HH} (n) is the second upper limit of the room temperature permissible in the nth room. φ _{RM_SP_LL} (n) is the second lower limit of indoor humidity permissible in the nth room. φ _{RM_SP_L} (n) is the first lower limit of the allowable indoor humidity in the nth room. φ% (n) is the permissible range of relative humidity applied to the nth room. The phi _alpha, a correction value of the allowable range of the relative humidity, the initial value is a 0.5. φ _{RM_SP_H} (n) is the first upper limit of indoor humidity permissible in the nth room. φ _{RM_SP_HH} (n) is the second upper limit of indoor humidity permissible in the nth room. The lower limit and the upper limit are set in the first and second stages in this way to suppress the transient fluctuation of the indoor environment due to the temperature change of cold water and to generate the heat in the room. This is to suppress deviation from the control range of the indoor environment due to changes in outside air conditions.

In step S304, the central controller 3 _acquires the temperature t RM_PV (n) and the relative humidity φ _{RM_PV} (n) in the nth room from the air conditioner controller 14.

In step S305, the central controller 3 determines whether or not the temperature and relative humidity in the nth room acquired in step S304 are within the permissible range with respect to the set temperature. In step S305 of FIG. 7, an indoor air conditioning state determination table used for this determination is exemplified. In the indoor air-conditioning state determination table, a matrix is formed in which the allowable value of temperature determined in step S303 is on the horizontal axis and the allowable value of relative humidity is on the vertical axis. By referring to the indoor air conditioning state determination table, the central controller 3 can determine whether or not to change the refrigerator chilled water outlet temperature based on the indoor temperature and relative humidity and the allowable range determined in S303. In the indoor air-conditioning state determination table, "1 ↓" is described in the area of _{t RM_PV} (n)> t _{RM_SP_HH} (n) and the area of φ _{RM_PV} (n)> φ _{RM_SP_HH (n).} t _{RM_PV} (n) <t _{RM_SP_L} (n) and φ _{RM_PV} (n) <φ _{RM_SP_LL} (n) region, t _{RM_PV} (n) <t _{RM_SP_LL} (n) and φ _{RM_PV} (n) <φ _{RM_SP_L} (n) In the area, it is described as "1 ↑". t _{RM_SP_H} (n) <t _{RM_PV} (n) <t _{RM_SP_HH} (n) and φ _{RM_PV} (n) <φ _{RM_SP_H} (n) region, t _{RM_PV} (n) <t _{RM_SP_HH} (n) and φ _{RM_SP_H} (n) < In _{the region of φ RM_PV} (n) <φ _{RM_SP_HH} (n), it is described as “2 ↓”. t _{RM_SP_L} (n) <t _{RM_PV} (n) <t _{RM_SP_H} (n) and φ _{RM_PV} (n) <φ _{RM_SP_L} (n) area, t _{RM_SP_LL} (n) <t _{RM_PV} (n) <t _{RM_SP_L} (n) and φ _{RM_SP_LL} (n) <φ _{RM_PV} (n) <φ _{RM_SP_H} (n) region, t _{RM_PV} (n) <t _{RM_SP_L} (n) and φ _{RM_SP_L} (n) <φ _{RM_PV} (n) <φ _{RM_SP_H} (n) In the area, it is described as "2 ↑". In the area of t _{RM_SP_L} (n) <t _{RM_PV} (n) <t _{RM_SP_H} (n) and φ _{RM_SP_L} (n) <φ _{RM_PV} (n) <φ _{RM_SP_H} (n), it is described as “none”. The indoor air conditioning state determination table is held, for example, in the memory of the central controller 3.

In step S306, the central controller 3 stores the determination result for the temperature and relative humidity in the nth room performed in step S305. In step S307, when the determination of all the rooms targeted by the air conditioning system 1 is completed (YES in S307), the process proceeds to step S308. If the determination of all the rooms to be air-conditioned by the air-conditioning system 1 is not completed (NO in S307), the process is returned to step S301.

From step S308 to step S314, the central controller 3 determines whether or not to change the refrigerator chilled water outlet temperature based on the determination results for the temperature and relative humidity in each room stored in the process of step S306.

In step S308, the central controller 3 determines whether or not there is a room belonging to the area in which "1 ↓" of the indoor air conditioning state determination table is described in the determination result saved in step S306. If there is a room belonging to the area in which the determination result is "1 ↓" (YES in S308), the process proceeds to step S308A. If there is no room belonging to the area in which the determination result is "1 ↓" (NO in S308), the process proceeds to step S309.

In step S308A, the central controller 3 changes the memory setting value of the refrigerator chilled water outlet temperature output to the heat source controller 21 in step S106 so that the refrigerator chilled water outlet temperature drops by 0.5 ° C. However, if the temperature of the chilled water outlet of the chiller falls below the lower limit of the chilled water outlet temperature of the chiller registered in the setting file when the temperature is lowered by 0.5 ° C, the central controller 3 changes the setting of the chilled water outlet temperature of the chiller to the lower limit. .. After that, the process is terminated.

In step S309, the central controller 3 determines whether or not there is a room that belongs to the area described as "2 ↓" in the indoor air conditioning state determination table twice in a row in the determination result saved in step S306. To judge. If there is a room belonging to the area described as "2 ↓" twice in a row (YES in S309), the process proceeds to S309A. If there is no room belonging to the area described as "2 ↓" twice in a row (YES in S309), the process proceeds to S310.

In step S309A, the central controller 3 changes the memory setting value of the refrigerator chilled water outlet temperature output to the heat source controller 21 in step S106 so that the refrigerator chilled water outlet temperature drops by 0.5 ° C. However, if the temperature of the chilled water outlet of the chiller falls below the lower limit of the chilled water outlet temperature of the chiller registered in the setting file when the temperature is lowered by 0.5 ° C, the central controller 3 changes the setting of the chilled water outlet temperature of the chiller to the lower limit. .. After that, the process is terminated.

In step S310, the central controller 3 determines whether or not there is a room belonging to the area described as "2 ↓" in the indoor air conditioning state determination table in the determination result saved in S306. If there is a room belonging to the area described as "2 ↓" (YES in S310), the process proceeds to step S310A. If there is no room belonging to the area described as "2 ↓" (NO in S310), the process proceeds to S311.

In step S310A, the central controller 3 does not change the refrigerator chilled water outlet temperature. After that, the process is terminated.

In step S311, the central controller 3 determines whether or not there is a room belonging to the area described as “none” in the indoor air conditioning state determination table in the determination result saved in step S306. If there is a room belonging to the area described as "None" (YES in S311), the process proceeds to step S311A. If there is no room belonging to the area described as "None" (NO in S311), the process proceeds to step S312.

In step S311A, the central controller 3 does not change the refrigerator chilled water outlet temperature. After that, the process is terminated.

In step S312, the central controller 3 determines whether or not there is a room belonging to the area described as "1 ↑" in the indoor air conditioning state determination table in the determination result saved in step S306. If there is a room belonging to the area described as "1 ↑" (YES in S312), the process proceeds to step S312A. If there is no room belonging to the area described as "1 ↑" (NO in S312), the process proceeds to step S313.

In step S312A, the central controller 3 changes the memory setting value of the refrigerator chilled water outlet temperature output to the heat source controller 21 in step S106 so that the refrigerator chilled water outlet temperature rises by 0.5 ° C. However, if the refrigerator chilled water outlet temperature raised by 0.5 ° C _{exceeds the upper limit of the chiller chilled water outlet temperature (CS Lim} ), the central controller 3 changes the setting of the chiller chilled water outlet temperature to the upper limit. After that, the process is terminated.

In step S313, the central controller 3 belongs to the area described as "2 ↑" in the indoor air conditioning state determination table and belongs to the area described as "2 ↑" in the determination result saved in step S306. Determines if there is a room that is not twice in a row. If there is a room that belongs to the area described as "2 ↑" and does not belong to it twice in a row (YES in S313), the process proceeds to step S313A. If there is no room that belongs to the area described as "2 ↑" and does not belong to it twice in a row (NO in S313), the process proceeds to step S314.

In step S313A, the central controller 3 does not change the refrigerator chilled water outlet temperature. After that, the process is terminated.

In step S314, in the determination result saved in step S306, all the rooms to be air-conditioned belong to the area described as "2 ↑" in the indoor air-conditioning state determination table twice in a row. Determine if it has become. If all the rooms to be air-conditioned belong to the area described as "2 ↑" twice in a row (YES in S314), the process proceeds to step S314A. If there is a room that does not belong to the area described as "2 ↑" twice in a row (NO in S314), the process ends.

In step S314A, the central controller 3 changes the memory setting value of the refrigerator chilled water outlet temperature output to the heat source controller 21 in step S106 so that the refrigerator chilled water outlet temperature rises by 0.5 ° C. However, if the refrigerator chilled water outlet temperature raised by 0.5 ° C _{exceeds the upper limit of the chiller chilled water outlet temperature (CS Lim} ), the central controller 3 changes the setting of the chiller chilled water outlet temperature to the upper limit. After that, the process is terminated.

The central controller 3 determines whether or not to change the refrigerator chilled water outlet temperature based on the indoor conditions acquired from the air conditioner controller 14 and the allowable range set in step S303 of FIG. Therefore, the central controller 3 can optimize the temperature of the chilled water outlet of the refrigerator in a more realistic manner than when controlling based on the virtual room design conditions, and can be expected to improve the COP of the entire air conditioning system 1. ..

<Step S104>
In step S104, the central controller 3 infers the cooling tower cooling water outlet temperature (cooling water temperature). The central controller 3 assumes an approach temperature, which is a parameter for determining the cooling water temperature, within a predetermined range. The central controller 3 calculates the energy consumption of the air conditioning system 1 from the cooling water temperature determined according to the outside air condition for each assumed approach temperature, and determines the cooling water temperature at which the energy consumption is minimized. The central controller 3 changes the setting value of the cooling water temperature memory output to the cooling tower controller 32 in step S106 so as to be controlled by the determined cooling water temperature.

In the inference of step S104, the central controller 3 assumes the approach temperature within a predetermined range, and optimizes the cooling water temperature while suppressing the amount of calculation. If the cooling water temperature is optimized, the operating efficiency of the cooling tower 30 will increase, and the COP of the entire air conditioning system 1 can be expected to improve.

8 to 10 are diagrams for explaining the inference of the cooling water temperature based on the approach temperature. FIG. 8 is a diagram illustrating items used for inferring the cooling tower and the cooling water temperature. The parameter for inferring the cooling water temperature of the cooling tower is the cooling tower approach temperature _TAP (° C). The input items are the outside air wet-bulb temperature T _WB (° C), the cooling tower heat dissipation amount q _CT (kW), and the cooling water inlet temperature T _CDR (° C). Central controller 3 based on the input fields, to optimize the cooling water flow rate _Q CD (L / min) and cooling tower fan air flow G ^(m 3 / h). During optimization, the cooling water flow rate _{Q CD} is controlled in the range of 50-100%. Further, the cooling tower fan air volume G is controlled in the range of 20 to 100%. Central controller 3, the cooling water flow rate Q _CD and from the cooling tower fan air volume G, to calculate the power and energy consumption of the power or the like of the cooling tower fan 31 of the cooling water circulation pump 51, a heat source system (air conditioning system 1 is an evaluation item ) Evaluate the COP. _{The cooling water temperature TCDS} (° C.) when the energy consumption of the air conditioning system 1 is the minimum, that is, the COP of the air conditioning system 1 is the maximum is output as an output item.

FIG. 9 is a graph illustrating the range of the cooling water temperature based on the outside air wet-bulb temperature and the approach temperature. In the graph of FIG. 9, the vertical axis is the cooling water temperature and the horizontal axis is the outside air wet-bulb temperature. The approach temperature is assumed to be in the range of 2 ° C to 5 ° C. The cooling water temperature is calculated as the temperature obtained by adding the approach temperature to the outside air wet-bulb temperature. The operating flow rate load factor of the cooling tower 30 is assumed to be 40% to 100%.

In the example of FIG. 9, the optimum operating range for the cooling water temperature of the cooling tower 30 is the range obtained by adding the approach temperature of 2 ° C. to 5 ° C. to the outside air wet-bulb temperature. When the outside air wet-bulb temperature changes in the range of 10 ° C. to 27 ° C., the cooling water temperature is set in the range of 12 ° C. to 32 ° C. depending on the approach temperature, and the control target value of the cooling water temperature is set. For example, when the outside air wet-bulb temperature is 16 ° C., the control target value of the cooling water temperature is in the range of 18 ° C. to 21 ° C. If the approach temperature is assumed to be in the range of 2 ° C to 5 ° C, for example in 0.5 ° C increments, the control target values for the cooling water temperature are 18 ° C, 18.5 ° C, ..., 21 ° C and 0.5 ° C increments. Is the value of. The central controller 3 calculates the energy consumption of the air conditioning system 1 for each control target value, and determines the control target value when the calculated energy consumption is the minimum as the cooling water temperature to be set.

FIG. 10 is a flowchart illustrating the flow of the inference processing of the cooling water temperature. FIG. 10 is a diagram showing an example of details of the processing of S104. The cooling water temperature inference process is executed by the central controller 3 at predetermined intervals, for example, at 10-minute intervals. Further, the inference process of the cooling water temperature may be started when the central controller 3 detects a change in the outside air condition.

In step S401, the central controller 3 calculates the outside air wet-bulb temperature from the measured outside air dry-bulb temperature and outside air relative humidity. The outside air wet-bulb temperature can be calculated from the saturated water vapor pressure, the partial pressure of water vapor, the absolute temperature, and the enthalpy obtained from the outside air dry-bulb temperature and the outside air relative humidity.

In step S402, the central controller 3 assumes an approach temperature, which is a parameter for inferring the cooling water temperature of the cooling tower 30. The approach temperature is assumed at intervals of 0.5 ° C., for example, in the range of 2 ° C. to 5 ° C., and the energy consumption of the air conditioning system 1 is calculated for each approach temperature.

In step S403, the central controller 3 calculates the cooling water temperature as the control target value from the outside air wet-bulb temperature calculated in step S401 and the approach temperature assumed in step S402.

Steps S404 to S407 are processes for calculating the power of the cooling water circulation pump 51 of the refrigerator 20. In step S404, the central controller 3 calculates the heat dissipation amount of the entire system (hereinafter, simply referred to as “heat dissipation amount”) to be dissipated by the cooling tower 30 from the operating load factor of each of the refrigerators 20 in operation.

In step S405, the central controller 3 obtains the cooling water inlet / outlet temperature difference of the refrigerator 20 from the heat radiation amount calculated in step S404. The cooling water inlet / outlet temperature difference changes depending on the cooling water flow rate, and when the cooling water flow rate decreases, the cooling water staying time in the condenser of the refrigerator 20 becomes longer, so that the cooling water inlet / outlet temperature difference of the refrigerator 20 becomes large. .. Therefore, the central controller 3 calculates the cooling water inlet / outlet temperature difference, which affects the calculation of the cooling water flow rate, from the heat radiation amount calculated in step S404, in consideration of the influence on the COP due to the increase / decrease in the cooling water flow rate. ..

In step S406, the central controller 3 calculates the cooling water flow rate. The cooling water flow rate is calculated from the heat radiation amount calculated in step S404 and the cooling water inlet / outlet temperature difference obtained in step S405.

In step S407, the central controller 3 calculates the power of the cooling water circulation pump 51 of the refrigerator 20 from the cooling water flow rate calculated in step S406.

Steps S408 to S411 are processes for calculating the air volume of the cooling tower fan 31. In step S408, the central controller 3 calculates the cooling water inlet temperature of the cooling tower 30 from the cooling water temperature calculated in step S403 and the cooling water inlet / outlet temperature difference of the refrigerator 20 obtained in step S405.

In step S409, the central controller 3 calculates the inlet air enthalpy of the cooling tower 30 from the cooling water inlet temperature calculated in step S408. In step S410, the central controller 3 calculates the outlet air enthalpy of the cooling tower 30 from the cooling water temperature calculated in step S403.

In step S411, the central controller 3 calculates the air volume of the cooling tower fan 31 from the heat dissipation amount calculated in step S404, the inlet air enthalpy calculated in step S409, and the outlet air enthalpy calculated in step S410.

In step S412, the central controller 3 verifies whether or not the air volume G of the cooling tower fan 31 calculated in step S411 is equal to or less than _{the rated air volume G 0 of the cooling tower 30.} The rated air volume G ₀ is an air volume calculated based on the flow rate of the cooling water, the amount of heat released, and the like. The central controller 3 calculates the energy consumption of the air conditioning system 1 when the air volume G of the cooling tower fan 31 _{is equal to or less than the rated air volume G 0.} On the other hand, when the air volume G of the cooling tower fan 31 _{is larger than the rated air volume G 0} , the central controller 3 returns to step S402, assumes the next approach temperature, and repeats the processes after step S403. The central controller 3, by air volume G of the cooling tower fan 31 does not execute the arithmetic processing is larger than the rated air volume G _0, it is possible to suppress the amount of calculation.

In step S413, the central controller 3 calculates the power of the cooling tower fan 31 from the air volume of the cooling tower fan 31 calculated in step S411.

In step S414, the central controller 3 uses the power of the cooling water circulation pump 51 calculated in step S407, the power of the cooling tower fan 31 calculated in step S413, the power consumption of the refrigerator 20, and the refrigerator 20 to circulate the cold water. The total value of the power consumption of the pumps (cold water primary pump 41) provided in the above is calculated as the power consumption of the air conditioning system 1. The central controller 3 repeats the process of calculating the power consumption of the air conditioning system 1 only under the condition that step S412 is satisfied for each approach temperature assumed in step S402, and saves the power consumption of the air conditioning system 1 in the memory. .. Then, the central controller 3 selects the approach temperature at which the power consumption of the air conditioning system 1 is minimized from the power consumption stored in the memory. At that time, the central controller 3 uses the chilled water temperature estimated in step S103, and selects the approach temperature at which the power consumption of the air conditioning system 1 is minimized in the case of the estimated chilled water temperature. Then, the central controller 3 obtains a value obtained by adding this approach temperature to the outside air wet-bulb temperature as the cooling water temperature, and determines this value as the control value. The central controller 3 changes the setting value of the cooling water temperature memory output to the cooling tower controller 32 in step S106 so as to be controlled by the determined cooling water temperature. As a result, the approach temperature in the case of the estimated cold water temperature is selected, so that the amount of calculation is suppressed as compared with the case where the calculation process is performed regardless of whether or not it is within the range of the cooling water temperature that can be cooled by the cooling tower. To. The cooling tower controller 32 controls so that the cooling water temperature, which reduces the energy consumption of the entire air conditioning system even when the outside air temperature is high and the heat load is high, is the control value sent from the central controller 3. Will be.

<Step S105>
In step S105, the central controller 3 infers the number of operating units of the refrigerator 20.
The central controller 3 infers the number of operating units of the refrigerator 20 based on the operation design sheet prepared in advance. The operation design sheet includes operation information that specifies the number of operations of the refrigerator 20 that minimizes the energy consumption of the air conditioning system 1 for each operation condition (refrigerator chilled water outlet temperature and cooling tower cooling water outlet temperature). Yes, it is created in advance based on the performance data of the refrigerator 20 according to the operating conditions and the characteristic data of each device such as a pump and a fan. The characteristic data is data showing the power for the performance of each device such as the discharge amount of the pump. The refrigerator 20 is an example of a “heat source machine”. The operation design sheet is an example of "operation information".

The central controller 3 is a refrigerator 20 that minimizes the energy consumption of the air conditioning system 1 from the operation design sheet prepared in advance based on the refrigerator chilled water outlet temperature and the cooling water temperature inferred in steps S103 and S104. Get the number of operating units. The central controller 3 changes the setting value of the memory of the operating number of the refrigerator 20 output to the heat source controller 21 in step S106 so as to be controlled by the acquired operating number of the refrigerator 20.

In the inference of step S105, the central controller 3 tries to optimize the number of operating units of the refrigerator 20 by acquiring the operation information according to the operation conditions from the operation design sheet created in advance. If the number of operating units of the refrigerator 20 is optimized, the operating efficiency of the refrigerator 20 can be improved, and the COP of the entire air conditioning system 1 can be expected to be improved.

The operation design sheet referred to by the central controller 3 in this step S105 is created, for example, as follows. 11 to 17 are diagrams for explaining the creation of an operation design sheet for inferring the number of operating units of the refrigerator 20. FIG. 11 is a diagram illustrating the calculation of the power consumption of the refrigerator for each operating condition. The partial load characteristic diagram (hereinafter, also referred to as performance data) according to the model and capacity of the refrigerator 20 (heat source) is given by the manufacturer of the refrigerator 20 or by actual measurement. The performance data is a diagram showing changes in the COP of the refrigerator 20 with respect to the load factor of the refrigerator 20 for each refrigerator 20, chilled water temperature, and cooling water temperature. The performance data of the type of the refrigerator 20 to which the performance data is not given in advance can be supplemented based on the performance data prepared in advance as the reference data. Further, the performance data for the chilled water temperature and the cooling water temperature for which the performance data is not given in advance can be interpolated based on the performance data for the temperatures before and after. By complementing or interpolating the insufficient performance data with respect to the existing performance data, for each refrigerator 20, for example, the cooling water temperature is in 1 ° C increments and the chilled water temperature is in 0.5 ° C increments. Be prepared. The central controller 3 or other computers used to create the operation design sheet can calculate the power consumption of each refrigerator 20 for each operating condition from the prepared performance data. The calculated power consumption of each refrigerator 20 is used to specify the number of operating units of the refrigerator 20.

FIG. 12 is a diagram illustrating the calculation of the power consumption of the auxiliary machine for each load factor of the refrigerator. For auxiliary equipment such as various pumps and various fans included in the cooling tower 30 and the refrigerator 20, each auxiliary equipment is used for each load factor of the refrigerator 20 based on the control method and characteristic diagram (characteristic data) of each auxiliary equipment. Calculate the power consumption of the machine and create a list of power consumption. The created list of power consumption of auxiliary equipment is used to identify the number of operating units of the refrigerator 20.

FIG. 13 is a diagram illustrating complementation of performance characteristic data. Hereinafter, the performance characteristic data is also simply referred to as performance data. When creating the operation design sheet, the performance data for each operating condition of the refrigerator 20 as a reference is registered in advance in the computer used for creating the operation design sheet (hereinafter, simply referred to as "computer") as the reference data. .. When the performance data for the refrigerator 20 to be evaluated is insufficient, the computer compares the existing performance data for the refrigerator 20 to be evaluated with the reference data under the same operating conditions to grasp the difference. The computer complements the performance data of the refrigerator 20 to be evaluated under the operating conditions based on the grasped difference from the reference data under the operating conditions in which the performance data does not exist for the refrigerator 20 to be evaluated. By complementing the performance data, the computer can infer the power consumption of the refrigerator 20 for each operating condition and specify the number of operating units of the refrigerator 20 that minimizes the energy consumption of the air conditioning system 1.

FIG. 14 is a diagram illustrating the operation priority of the refrigerator. The operation priority of the refrigerator 20 is changed periodically by the equipment manager, or is automatically changed by the central controller 3 or its management device according to the operating time of the air conditioning system 1. Since the performance is different for each of the refrigerators 20, the number of refrigerators 20 that minimizes the energy consumption of the air conditioning system 1 differs depending on the operation priority. Therefore, the operation design sheet is created for each combination of operation priorities.

FIG. 14 shows in a table format an example of a combination of operation priorities for three refrigerators 20 (heat source 1, heat source 2, and heat source 3). When there are three refrigerators 20, there are six combinations of operation priorities. In the table of FIG. 14, the left column is a name for identifying the operation design sheet. For example, in the operation design sheet TR_MAP_132 described in the second row, the operation priority is in the order of heat source 1, heat source 3, and heat source 2. It is an operation design sheet in a certain case. The central controller 3 monitors the operation priority of the refrigerator 20, and when the priority is changed due to rotation or maintenance of the refrigerator 20, the central controller 3 refers to the corresponding operation design sheet and refers to the refrigerator 20. Infer the number of units in operation.

FIG. 15 is a diagram illustrating an operation design sheet. In the example of FIG. 15, the operation design sheet is created for each chilled water temperature, and the number of operating units according to the load factor of the heat source (refrigerator 20) is specified for each cooling water temperature. Specifically, when the cold water temperature is 7 ° C and the cooling water temperature is 24 ° C, the number of operating refrigerators 20 that minimizes the energy consumption of the air conditioning system 1 is two when the heat source load factor is 33% or more. There are 3 units at 55% or more. By defining the number of operating refrigerators 20 having the highest COP of the entire air conditioning system 1 from the chilled water temperature and the chilled water temperature in such an operation design sheet prepared in advance, the central controller 3 can be used. It is possible to control the number of operating units of the refrigerator 20 based on the information of the chilled water temperature and the chilled water temperature obtained from the heat source controller 21 and the like.

FIG. 16 is a graph illustrating an increase in the number of heat source operations. The vertical axis is the number of heat source operations, and the horizontal axis is the heat source load factor. FIG. 16 is a graph showing an example in the case of the cold water temperature of 7 ° C. and the cooling water temperature of 24 ° C. shown in FIG. Further, the operation priority of the heat source is the order of the heat source 1, the heat source 2, and the heat source 3, and the number of heat source operations is controlled based on the corresponding operation design sheet. P1 shown on the horizontal axis is a threshold value of the heat source load factor when the number of heat source operating units is increased from one to two. In the example of FIG. 16, P1 is 33%, the number of operating units is increased from 1 to 2 when the heat source load factor is 33% or more, and the number of operating units is increased from 2 when the heat source load factor is smaller than 33%. The stage is reduced to one. Similarly, P2 shown on the horizontal axis is a threshold value of the heat source load factor when the number of heat source operating units is increased from two to three. In the example of FIG. 16, P2 is 55%, the number of operating units is increased from 2 to 3 when the heat source load factor is 55% or more, and the number of operating units is increased from 3 when the heat source load factor is smaller than 55%. The stage is reduced to two. The threshold values of the heat source load factor (hereinafter, also referred to as increase / decrease stage points) P1 and P2 that control the number of operating units are based on the measurement data of the heat source load factor and the conditions such as whether the heat source load factor is on an upward trend or a downward trend. Be identified.

FIG. 17 is a graph showing an example of the correlation between the load factor of the entire heat source and the COP of the entire system. The vertical axis is the COP of the heat source system, and the horizontal axis is the load factor of the entire heat source. The equipment assumed in the creation of the graph in FIG. 17 is an inverter type, and is a turbo chiller, a chilled water pump, a cooling water pump, and two integrated cooling towers each. The cold water temperature is assumed to be 7 ° C. The values indicated by the arrows in the figure indicate the points of increase / decrease of the heat source. As can be seen from the graph of FIG. 17, as the temperature of the cooling water decreases, the increase / decrease stage point shifts to the low load factor side. This is because the performance diagram of the heat source alone shifts the maximum efficiency point to the low load factor side as the cooling water temperature decreases. Therefore, in the operation design sheet used for the central controller 3, as shown in the graph shown in FIG. 17, the points for increasing / decreasing the heat source are set at slightly different positions for each cooling water temperature.

FIG. 18 is a flowchart illustrating a process of creating an operation design sheet. The computer used to create the operation design sheet performs the following processing before starting the operation of the air conditioning system 1 to create the operation design sheet. The computer also executes the following processing when recreating the operation design sheet when the configurations of the refrigerator 20, the cooling tower 30, and the auxiliary equipment included in the air conditioning system 1 are changed. The created operation design sheet is stored in a computer or an auxiliary storage device included in the central controller 3. The auxiliary storage device included in the central controller 3 is an example of a “storage unit”.

In step S501, the computer reads the configuration of the heat source system (air conditioning system 1). Specifically, the computer reads information such as the number of auxiliary machines such as the refrigerator 20, the cooling tower 30, various pumps, and various fans constituting the air conditioning system 1.

In step S502, the computer repeats the process from step S503 to step S507 within the range of the chilled water temperature (refrigerator chilled water outlet temperature) of 5 ° C. to 12 ° C., for example, at intervals of 0.5 ° C. That is, an operation design sheet is created for each cold water temperature in increments of 0.5 ° C. The operation design sheet is not limited to the case where the cold water temperature is prepared every 0.5 ° C. By creating the operation design sheet at narrower temperature intervals, the accuracy of inferring the number of operating units of the heat source (refrigerator 20) is improved. Further, the computer may create an operation design sheet not only for each chilled water temperature at equal intervals but also for each preset chilled water temperature. This makes it possible to create a flexible operation design sheet according to the configuration of the air conditioning system 1.

In step S503, the computer repeats the processes from step S504 to step S506 within the range of the cooling water temperature (cooling tower cooling water outlet temperature) of 12 ° C. to 34 ° C., for example, at intervals of 1 ° C. That is, the computer repeats the process of inferring the number of heat source operations according to the heat source load factor for each cooling water temperature at 1 ° C. intervals. The inference of the number of heat source operations is not limited to every 1 ° C. for the cooling water temperature, and may be inferred for each preset cooling water temperature. As can be seen from FIG. 17, in the case of the heat source alone, the highest efficiency point (the highest point of the convex portion on the left side of the graph) shifts to the low load factor side as the cooling water temperature decreases. The cooling water temperature that infers the number of operating heat source units can be set in consideration of the deviation.

In step S504, the computer calculates the number of operating heat sources that minimizes the energy consumption of the air conditioning system 1 in the range of the heat source load factor of 20% to 100%, for example, for each heat source load factor at 10% intervals. Repeat the process. The calculation of the number of operating heat sources is not limited to 10% intervals, and the computer calculates the number of operating heat sources at 1% intervals, for example, within the range of the heat source load factor before and after the calculated number of operating heat sources is switched. May be good.

In step S505, the computer uses the cold water temperature (5 ° C to 12 ° C) set in step S502, the cooling water temperature (12 ° C to 34 ° C) set in step S503, and the total heat source load set in step S504. Based on the rate (20% to 100%), that is, using these values as parameters, the number of operating heat sources that minimizes the energy consumption of the air conditioning system 1 is calculated under the combination conditions of these values. Specifically, first, the device information (characteristic data as shown in FIGS. 11 and 12) read in step S501 is referred to, and the set cold water temperature, cooling water temperature, and total heat source load factor are set. Read the corresponding COP value of the refrigerator alone and the power consumption value of the pump and fan. The power consumption of the refrigerator is calculated based on the COP of the refrigerator alone and the heat source load factor. Then, the value of the power consumption of the refrigerator alone and the total value of the power consumption of the pump and the fan are calculated as the energy consumption. The computer performs the above-mentioned calculation process for all the combined conditions of the chilled water temperature, the chilled water temperature, and the total load factor of the heat source. Then, the computer stores the energy consumption calculated for each combination condition in the auxiliary storage device as the calculation result under the combination condition. Next, when there are two or more heat sources, the power consumption value of the heat source is calculated individually based on the value obtained by dividing the total load factor of the heat source by the number of heat sources. The value of the power consumption of the plurality of heat sources is added to the power consumption of the pump and the fan to obtain the energy consumption. If the priority of the heat source is set, such as when the performance of the heat source is different, the power consumption of the heat source is calculated individually according to the priority. When there are two or more heat sources, the energy of the air conditioning system 1 when there are two or more heat sources described above for all of the combination patterns of multiple heat sources (when there is one heat source or when there are two or more heat sources). Calculate the amount of consumption. Then, for all the combination conditions of the chilled water temperature, the cooling water temperature, and the total load factor of the heat source, the energy consumption in all the combination patterns of the plurality of heat sources is compared with each other, and the operation of the heat source when the energy consumption is minimized is performed. The number of units is selected as the number of operating units of the heat source under the combined condition of the chilled water temperature, the cooling water temperature, and the total load factor of the heat source, and the number of operating units is stored in the auxiliary storage device. In this way, for each chilled water temperature, the number of operating heat sources corresponding to the cooling water temperature and the total load factor of the heat source is obtained, and the obtained number of operating units is stored in a table, that is, an operation design sheet as shown in FIG. .. The power consumption of the cooling water circulation pump 51, the power of the cooling tower fan 31, and the load factor of the cold water primary pump 41 are obtained on the assumption that they are the same as the overall load factor of the heat source of the refrigerator 20.

In step S506, the computer determines whether or not the calculation for calculating the number of operating units has been completed for each heat source load factor within the range specified in step S504. When the calculation for calculating the number of operating units for each heat source load factor is completed (S506; YES), the process proceeds to step S507. If the calculation for calculating the number of operating units for each heat source load factor is not completed (S506; NO), the process returns to S504, and the process of S505 is executed for the next heat source load factor.

In step S507, the computer determines whether or not the calculation for calculating the number of operating units for each heat source load factor has been completed for each cooling water temperature within the range specified in step S503. When the calculation for each cooling water temperature is completed (S507; YES), the process proceeds to step S508. If the calculation for each cooling water temperature is not completed (S507; NO), the process returns to S503, and the processes from S504 to S506 are executed for the next cooling water temperature.

In step S508, the computer determines whether or not the calculation for calculating the number of operating units for each cooling water temperature and each heat source load factor has been completed for each chilled water temperature within the range specified in step S502. When the calculation for each cold water temperature is completed (S508; YES), the process proceeds to step S509. If the calculation for each cooling water temperature is not completed (S508; NO), the processing returns to S502, and the processing from S503 to S507 is executed for the next cooling water temperature.

In step S509, the computer completes the operation design sheet of the air conditioning system 1 for each heat source operation priority pattern. Specifically, the computer specifically identifies the increase / decrease stage point for controlling the number of operating units from the information on the number of operating units of the heat source calculated in step S505, based on the measured value of the heat source load factor, and prepares the operation design sheet. Finalize. In this way, the number of operating refrigerators 20 as a heat source can be obtained based on the information of the equipment constituting the air conditioning system 1 even if the outside air condition which is an environment variable is not given, and the operation of the air conditioning system 1 can be obtained. It is possible to calculate and save in advance before the start.

When the amount of reduction in power consumption is estimated, it depends on the equipment configuration and conditions of the entire system,
By adjusting the set value of the refrigerator chilled water outlet temperature and adjusting the number of operating units of the refrigerator 20 as described above by the central controller 3, the power consumption is ten compared to the case where such adjustment is not performed. Estimated results show that it can be reduced by a few percent.

1 ・ ・ Air conditioning system: 2 ・ ・ Network: 3 ・ ・ Central controller: 4 ・ ・ Indoor: 10 ・ ・ Air conditioner: 11 ・ ・ Coil: 12 ・ ・ Electric fan: 13 ・ ・ Air conditioner chilled water flow control valve: 14・ ・ Air conditioner controller: 20 ・ ・ Refrigerator: 21 ・ ・ Heat source controller: 30 ・ ・ Cooling tower: 31 ・ ・ Cooling tower fan: 32 ・ ・ Cooling tower controller: 40 ・ ・ Cold water circulation system: 41 ・ ・ Cold water 1 Secondary pump: 42 ... Cold water secondary pump: 43 ... Minimum flow valve: 44 ... Secondary pump controller: 50 ... Cooling water circulation system: 51 ... Cooling water circulation pump

Claims (10)

The acquisition unit that acquires the setting information of the air conditioner,
A first determination unit that determines the capacity of the air conditioner based on the setting information acquired by the acquisition unit.
A second determination unit that determines a control target value of the chilled water outlet temperature of the heat source machine based on the capacity of the air conditioner determined by the first determination unit.
A first determination unit for determining whether or not to execute the determination of the control target value based on the capacity of the air conditioner, the outside air condition, and the heat source load condition is provided.
Control device for air conditioning system. The first determination unit determines the design conditions of the air-conditioned space of the air conditioner, and determines the necessity of dehumidifying the air-conditioned space based on the comparison between the design conditions and the outside air condition.
The control device for the air conditioning system according to claim 1. The acquisition unit that acquires the setting information of the air conditioner,
A first determination unit that determines the capacity of the air conditioner based on the setting information acquired by the acquisition unit.
A second determination unit for determining a control target value of the chilled water outlet temperature of the heat source machine based on the capacity of the air conditioner determined by the first determination unit is provided.
The capacity of the air conditioner includes the amount of heat absorbed by the cold water by passing the cold water through the coil of the air conditioner and the amount of air supply air of the air conditioner.
The second determination unit is new based on the cold water outlet temperature of the heat source machine, the temperature of the supply air before and after heat exchange with the cold water in the air conditioner, the heat amount, and the supply air amount. The control target value is determined, and the control target value is determined.
The air supply air volume is reduced according to the heat load in the air-conditioned space of the air conditioner.
When the reduced air supply air volume reaches a predetermined value, the set value of the cold water inlet temperature of the coil of the air conditioner is increased.
The control device of the air-conditioning system. Further, a second determination unit for determining whether or not to execute the determination of the control target value is provided.
The second determination unit determines the design conditions of the air-conditioned space, and determines the necessity of dehumidifying the air-conditioned space based on the comparison between the design conditions and the outside air condition.
The control device for the air conditioning system according to claim 3. The acquisition step in which the control device of the air conditioning system acquires the setting information of the air conditioner,
The first determination step of determining the capacity of the air conditioner based on the setting information acquired in the acquisition step, and
The second determination step of determining the control target value of the chilled water outlet temperature of the heat source machine based on the capacity of the air conditioner determined in the first determination step,
A determination step for determining whether or not to execute the determination of the control target value based on the capacity of the air conditioner, the outside air condition, and the heat source load condition is included.
How to control the air conditioning system. In the determination step, the design conditions of the air-conditioned space of the air conditioner are determined, and the necessity of dehumidifying the air-conditioned space based on the comparison between the design conditions and the outside air condition is determined.
The control method for an air conditioning system according to claim 5. For the control device of the air conditioning system
The acquisition process to acquire the setting information of the air conditioner and
The first determination process for determining the capacity of the air conditioner based on the setting information acquired in the acquisition process, and
The second determination process of determining the control target value of the chilled water outlet temperature of the heat source machine based on the capacity of the air conditioner determined in the first determination process.
A determination process of whether or not to execute the determination of the control target value based on the capacity of the air conditioner, the outside air condition, and the heat source load condition is executed.
Air conditioning system control program. The determination process includes determining the design condition of the air-conditioned space of the air conditioner, and determining the necessity of dehumidifying the air-conditioned space based on the comparison between the design condition and the outside air condition.
The control program for the air conditioning system according to claim 7. With a heat source machine
With an air conditioner
The heat source machine and the control device for controlling the air conditioner are provided.
The control device is
The acquisition unit that acquires the setting information of the air conditioner and
A first determination unit that determines the capacity of the air conditioner based on the setting information acquired by the acquisition unit.
A second determination unit that determines a control target value of the chilled water outlet temperature of the heat source machine based on the capacity of the air conditioner determined by the first determination unit.
It has a third determination unit for determining whether or not to execute the determination of the control target value based on the capacity of the air conditioner, the outside air condition, and the heat source load condition .
Air conditioning system. The third determination unit determines the design conditions of the air conditioning target space of the air conditioner, to determine the dehumidification of the need for the air conditioning target space based on a comparison with the design conditions and ambient conditions,
Air-conditioning system according to claim 9.

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