JP2009198021A - Air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning system for reducing energy consumption while compensating air adjusting performance in an air conditioner. <P>SOLUTION: This air conditioning system 1 includes: the air conditioner 2; a heat source machine 3 for supplying the cold or heat to the air conditioner; a control target value deciding means 13 deciding a control target value; and a heat medium controlling means 12C for controlling a state quantity of a heat medium so that the state quantity of the heat medium pressure-fed to the air conditioner 2 reaches the control target value decided by the control target value deciding means 13. The control target value deciding means 13 estimates the required state quantity as the state quantity of the heat medium needed by the air conditioner 2, decides the estimated required state quantity as the control target value when the estimated required state quantity satisfies prescribed conditions, and decides the predetermined state quantity satisfying the prescribed conditions as the control target value when the estimated required state quantity does not satisfy the prescribed conditions. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an air conditioning system.

In buildings, etc., a centralized system that distributes cold water and hot water generated by cold heat source equipment such as refrigerators and boilers, and the above-mentioned heat medium such as ice water slurry to air handling units, fan coil units, etc. in buildings, factories, underground malls, etc. Many air conditioning systems are used. In the air conditioning system, in order to increase the operating efficiency of each air conditioning device constituting the system, a technique for optimizing the temperature and flow rate of the refrigerant circulation system according to the change in the heat balance has been developed (for example, Patent Documents 1 and 2). See).
Japanese Patent No. 2527643 JP 2007-205604 A

  An air conditioning system is desired to increase the operating efficiency of each air conditioner constituting the system and reduce the power consumption of the entire system. Here, in the case of a centralized air conditioning system, heat transport from a heat source that produces cold or warm heat to an air conditioner installed in each room or the like is performed by sending a heat medium. Since the energy consumed for transporting such a heat medium does not directly contribute to the adjustment of air, it is preferably reduced as much as possible. That is, it is preferable that the amount of heat transported from the heat source to the air conditioner is the minimum necessary amount. However, since the minimum amount of heat necessary for air cooling, heating and other adjustments is transported, control of the air conditioner may be reduced if the pressure or temperature of the heat medium is reduced to the minimum amount. .

  In view of the above-described problems, an object of the present invention is to provide an air conditioning system that reduces energy consumption while compensating for air adjustment capability in an air conditioner.

  In order to solve the above problems, the present invention is such that the control target value of the state quantity of the heat medium sent to the air conditioner satisfies the condition set in advance from the viewpoint of ensuring the air adjustment capability of the air conditioner.

  Specifically, it is an air conditioning system that regulates indoor air, and an air conditioner that regulates the indoor air, and a cooling medium or a heat source that is used to regulate the indoor air by pumping a heat medium to the air conditioner. A heat source device to be supplied to the air conditioner; a control target value determining means for determining a control target value of a state quantity of the heat medium pumped to the air conditioner based on a state quantity of air adjusted by the air conditioner; A heat medium control means for controlling a state quantity of the heat medium to be pressure-fed to the air conditioner so that a state quantity of the heat medium to be pressure-fed to the machine becomes the control target value determined by the control target value determination means. And the control target value determining means estimates a required state quantity that is a state quantity of the heat medium necessary for the air conditioner to adjust the air based on an air state quantity adjusted by the air conditioner. The estimated required state quantity indicates the air conditioning capacity of the air conditioner. When the predetermined condition set in advance is maintained, the estimated required state quantity is determined as the control target value, and when the estimated required state quantity does not satisfy the predetermined condition, the predetermined condition A predetermined state quantity satisfying is determined as the control target value.

  The present invention is premised on heat transport by sending a heat medium from a heat source to an air conditioner. The heat medium for heat transport only needs to be able to transport the cold or warm heat produced by the heat source to the air conditioner, and examples thereof include water and brine. The air conditioning system is configured by combining one or a plurality of air conditioners and heat source machines.

  The amount of heat of the heat medium that the air conditioner uses to adjust the indoor air varies depending on the amount of air condition that the air conditioner adjusts. For example, the temperature of indoor air is extremely high during cooling, and a large amount of cooling is required when it is desired to greatly reduce the temperature. Therefore, the control target value determining means determines the control target value of the state quantity of the heat medium to be pumped to the air conditioner based on the air state quantity. That is, based on the state quantity of the air to be adjusted, a required state quantity that is a state quantity of the heat medium necessary for the air conditioner to adjust the air is estimated, and a control target value is determined based on the estimation result. Here, the air state quantity is a parameter indicating the physical state quantity of air related to air conditioning control, and is, for example, air temperature or humidity. By controlling the control target value of the state quantity of the heat medium pumped to the air conditioner in this way, the state quantity of the heat medium pumped from the heat source machine to the air conditioner is reduced to the amount necessary for air conditioning in the air conditioner. Can do. Further, the indoor air adjusted by the air conditioner is a concept that includes not only adjusting indoor air directly but also adjusting indirectly, for example, directly changing indoor air (return air). And those that indirectly adjust the indoor air by adjusting the mixture of the outside air and the return air or the outside air taken into the room.

  Here, when the estimation result of the requested state quantity estimated by the control target value determining means is used as it is for the control target value of the heat medium, the controllability of the air conditioner may be adversely affected. For example, if the amount of required heat, which is an example of the required state quantity, is an extremely large value, it is desirable to increase the temperature of the heat medium that is pumped to the air conditioner, but the heat medium that is too hot is pumped to the air conditioner. Then, the flow rate adjustment valve on the air conditioner side is narrowed down to the fully closed state, the flow rate of the heat medium is reduced, the amount of heat exchange between the air and the heat medium is reduced, and the controllability (response speed) of the temperature control is reduced. There is concern about a decline. In addition, for example, when the amount of required cold heat, which is an example of the required state amount, is a very small value, it is desirable to reduce the pressure loss by opening the flow rate adjustment valve on the air conditioner side to a state close to full open. If the water supply pressure is too low, the flow of the heat medium does not reach, and the amount of heat exchange between the air and the heat medium is reduced, and there is a concern that the controllability is lowered. Further, it is needless to say that the water supply pressure is excessive, and power costs are wasted. For example, if the water supply temperature is too high during cooling, dehumidification cannot be performed. In the case of an air conditioning system having a large number of air conditioners, since the amount of state of the heat medium required by each air conditioner is different, such a decrease in controllability is particularly a concern. Therefore, the control target value determining means checks whether the estimation result of the requested state quantity satisfies a predetermined condition and determines the control target value. The predetermined condition is a state quantity of the heat medium determined from the viewpoint of ensuring controllability of the air conditioner. For example, the pressure required for the heat medium to maintain controllability of temperature control in the air conditioner And a threshold value of a state quantity such as temperature. The predetermined physical quantity is a control target value that the control target value determining means indicates to the heat medium control means when the estimation result of the requested state quantity does not satisfy the predetermined condition. For example, the predetermined physical quantity is the state quantity indicated by the predetermined condition. It is the same value as the threshold value.

  According to the air conditioning system, since the control target value is determined from the viewpoint of ensuring controllability of the air conditioner, it is possible to reduce energy consumption while compensating for the air adjustment capability of the air conditioner.

In addition, the air conditioning system includes a flow rate detection unit that detects a flow rate of the heating medium, the flow rate of which is adjusted by the air conditioner, and a heat amount that is used by the air conditioner to adjust the indoor air. A flow rate adjusting means for adjusting the flow rate of the heat medium sent to the air conditioner, wherein the control target value determining means adjusts the air based on a detection result of the flow rate detecting means. Estimated as a required state quantity of the heat medium feed pressure required for the above, and a predetermined lower limit feed pressure set in advance to ensure the heat medium flow rate adjustment capability in the air conditioner as the predetermined condition If the feed pressure is equal to or greater than the predetermined lower limit feed pressure, the estimated feed pressure is determined as the control target value, and if the estimated feed pressure is less than the predetermined lower limit feed pressure, Predetermined A predetermined feed pressure equal to or higher than a limit feed pressure is determined as the control target value, and the heating medium control means sets the feed pressure of the heating medium to be fed to the air conditioner to the control target value determined by the control target value determination means. As such, the feed pressure of the heat medium fed to the air conditioner may be controlled.

  The pressure of the heat medium that the heat source machine should supply to the air conditioner is determined by the flow rate of the heat medium that the air conditioner side needs. Therefore, by detecting the flow rate of the heat medium adjusted by the flow rate adjusting means, the feed pressure of the heat medium can be lowered to the necessary minimum amount. By reducing the feed pressure to the minimum required amount, flow control (throttle flow rate) on the air conditioner side is relaxed and pressure loss is reduced. Here, as described above, when the estimation result of the feed pressure is low, there is a concern that the controllability of the flow rate adjusting unit may be affected. Therefore, the control target value determining means checks the estimation result of the feed pressure, and when it is significantly lower than the predetermined lower limit feed pressure, determines the default feed pressure as the control target value. Here, the predetermined lower limit feed pressure is a lower limit value of the feed pressure of the heat medium determined from the viewpoint of ensuring controllability of the air conditioner and corresponds to the above predetermined condition. This is a threshold value of pressure required for the heat medium to maintain controllability. The predetermined feed pressure is a control target value of the feed pressure that the control target value determining means indicates to the heat medium control means when the estimated result of the feed pressure falls below a predetermined lower limit feed pressure, and is equal to the predetermined physical quantity. For example, it is the same value as the predetermined lower limit feed pressure.

  According to this air conditioning system, since the control target value of the feed pressure is determined from the viewpoint of ensuring the controllability of the air conditioner, the heat medium is supplied with the minimum necessary pressure while compensating for the air adjustment capability of the air conditioner. It becomes possible to send.

  The predetermined lower limit feed pressure is estimated from the heat balance in the room where the air conditioner adjusts the air, and is used to ensure the flow rate of the heat medium required for the air conditioner to adjust the indoor air. It may be pressure. When the indoor load increases, for example, when a large amount of heat enters the indoor air to be adjusted due to solar radiation or an increase in people, or when a large amount of heat is generated from the indoor air due to solar radiation or a decrease in people, The amount of heat to be transported to the air conditioner increases. In this case, the flow rate of the heat medium required by the air conditioner increases. Therefore, it is possible to compensate the air adjustment capability in the air conditioner by determining the predetermined lower limit feed pressure with a parameter estimated from the heat balance amount.

  Further, the control target value determining means estimates, based on the state quantity of air adjusted by the air conditioner, the heating medium feed temperature required for the air conditioner to adjust the air as the required state quantity. If the predetermined temperature condition set in advance to ensure the air adjustment capability of the air conditioner is the predetermined condition, and the estimated feed temperature satisfies the predetermined temperature condition, the estimated feed temperature is When the estimated feed temperature determined as the control target value does not satisfy the predetermined temperature condition, a predetermined feed temperature satisfying the predetermined temperature condition is determined as the control target value, and the heating medium control means May control the feed temperature of the heat medium fed to the air conditioner so that the feed temperature of the heat medium fed to the air conditioner becomes the control target value determined by the control target value determining means. Good.

The temperature of the heat medium that the heat source machine should supply to the air conditioner varies depending on the amount of air state adjusted by the air conditioner. Therefore, it is possible to reduce the temperature of the heat medium supplied by the heat source unit to the minimum amount necessary for adjusting the air of the air conditioner by estimating the feed temperature of the heat medium based on the air state quantity adjusted by the air conditioner. it can. Here, as described above, if the estimation result of the feed temperature is too high during heating, for example, if a heat medium having a too high temperature is pumped to the air conditioner, there is a concern that the controllability of the air conditioner may be affected. . In addition, when the estimation result of the feed temperature is too low, for example, during cooling, there is a concern that if the heat medium having a too low temperature is pumped to the air conditioner, the controllability of the air conditioner will be affected. Therefore, the control target value determining means checks the estimated result of the feed temperature, and when this does not satisfy the predetermined temperature condition, determines the specified feed temperature as the control target value. Here, the predetermined temperature condition is an upper limit value and a lower limit value of the feed temperature of the heat medium determined from the viewpoint of ensuring controllability of the air conditioner and corresponds to the predetermined condition, for example, the temperature in the air conditioner It is the upper and lower thresholds of the temperature required for the heat medium to maintain controllability (for example, control capability by dehumidification capability or valve opening adjustment). The upper limit value of the feed temperature indicated by the predetermined temperature condition is, for example, a temperature necessary for ensuring the dehumidifying capacity in the air conditioner in the case of cooling. The predetermined feed temperature is the control target value of the feed temperature indicated by the control target value determining means to the heat medium control means when the estimated result of the feed temperature does not satisfy a predetermined temperature condition. For example, it is the same value as the upper and lower thresholds of the temperature indicated by the predetermined temperature condition.

  According to this air conditioning system, since the control target value of the feed temperature is determined from the viewpoint of ensuring controllability of the air conditioner, it is possible to send the minimum amount of heat while compensating for the air adjustment capability of the air conditioner. It becomes possible.

  The predetermined temperature condition is estimated from the amount of heat balance in the room where the air conditioner adjusts the air, and the amount of cold or warm heat required for the air conditioner to adjust the air in the room. It may be a temperature for securing As described above, the amount of heat to be transported from the heat source unit to the air conditioner changes as the amount of heat balance in the room to be adjusted changes. Therefore, it is possible to compensate for the air adjustment capability in the air conditioner by determining the predetermined temperature condition with a parameter estimated from the heat balance.

  In addition, the heat balance amount in the room includes the outside air temperature, the outside air humidity, the pressure of the heat medium, the flow rate of the heat medium, the temperature of the heat medium, the control parameters in the air conditioner, and the heat medium discharged from the air conditioner. It may be a physical quantity including any of these temperatures. The change in the indoor heat balance affects the required heat of the air conditioner, so the air conditioning capacity of the air conditioner can be compensated by setting the condition of the heat medium state based on the heat balance. Is possible. Here, the heat balance amount can be directly detected from the outside air temperature and humidity. For example, the heat balance amount is calculated from the difference between the outside air temperature and the indoor temperature setting value. In addition, since the room temperature is adjusted in the air conditioner, the change in the amount of heat balance in the room is caused by the pressure of the heat medium flowing from the heat source unit to the air conditioner, the flow rate of the heat medium, the temperature of the heat medium, It is also possible to detect indirectly by the temperature of the heat medium coming out of the air conditioner. By acquiring the indoor heat balance amount using such a physical quantity, it becomes possible to compensate for the air adjustment capability of the air conditioner.

  It is possible to provide an air conditioning system that reduces the energy consumption while compensating for the air conditioning capability of the air conditioner.

  Hereinafter, an embodiment of the present invention will be exemplarily described. Embodiment shown below is an illustration and this invention is not limited to these.

<Configuration of air conditioning system>
FIG. 1 is a configuration diagram of an air conditioning system 1 according to an embodiment of the present invention. As shown in FIG. 1, the air conditioning system 1 includes a secondary equipment 2 (corresponding to an air conditioner in the present invention) such as a fan coil unit installed in each room that is a target for air adjustment, and A cold heat source device 3 (corresponding to a heat source device in the present invention) such as a refrigerator that supplies cold energy to the secondary side equipment 2 via a heat medium is provided. A plurality of cold heat source devices 3 and secondary side facilities 2 are provided according to the number of rooms and the amount of required cold heat, respectively, and between the cold heat source device 3 and the secondary side facilities 2 is water carrying cold heat. A certain heat medium is configured to circulate. A return header 4 is provided in the middle of the pipe connecting the downstream side of the secondary side equipment 2 and the upstream side of the cold heat source equipment 3, and the heat medium returning from the plurality of secondary side equipments 2 is sent to the return header 4. After being collected, it is sent to the evaporator of the cold heat source device 3. A primary pump 5 is provided between the return header 4 and each cold heat source device 3, and feeds water to the cold heat source device 3. The heat medium cooled by each cold heat source device 3 is collected in the pump inlet header 6, then pressurized by a plurality of secondary pumps 7, and sent to the secondary equipment 2. The secondary pump 7 is driven by a variable speed motor using an inverter. A pump outlet header 8 is also provided on the outlet side of the secondary pump 7 so that the heat medium boosted by each secondary pump 7 is once collected in the header and then sent to the cold heat source device 3. It is configured. Further, the condenser of the cold heat source device 3 is provided with a cooling water circulation system including a cooling water circulation pump 9 and a cooling tower 10 in order to release heat recovered from the heat medium to the outside air by the action of vaporization heat. Further, a bypass pipe 11 for correcting a flow rate mismatch between the primary pump 5 and the secondary pump 7 is provided between the return header 4 and the pump inlet header 6.

  The air conditioning system 1 also includes an on-site controller 12 that processes the operation and measurement data of each device that constitutes the system, and an integrated controller 13 (corresponding to a control target value determining means in the present invention). A plurality of controllers 12 are installed near the devices and members to be controlled by the air conditioning system 1, provide measurement data to the integrated controller 13, which is a higher-level device, and receive instructions from the integrated controller 13 to receive on-site devices To control the operation. The controller 12 and the integrated controller 13 are computers including a CPU, a ROM, an input / output interface, and the like. The input data is subjected to numerical calculation processing, and the calculation result is output as a control signal or measurement data.

  Here, the secondary equipment 2 includes a heat exchange coil in which fins are attached to a pipe through which a heat medium (for example, cold water, hot water, steam, ice water slurry, etc.) flows, an electric fan that sends indoor air to the coil, A so-called air handling unit or fan coil unit. The secondary side equipment 2 is installed in a building, a factory, an underground mall, etc., and an electric fan exchanges heat with the coil while circulating indoor air. Thereby, while the temperature of indoor air is adjusted, dehumidification is performed. The secondary equipment 2 adjusts the indoor air indirectly by adjusting the mixture of the outside air and the return air, or adjusting the outside air to be taken into the room in addition to adjusting the return air in the room (so-called Or all fresh). In addition, the secondary equipment 2 is provided with an outside air intake duct having a damper that can be opened and closed in response to a command from the controller 12, so that the outside air can be taken into the room according to the command from the controller 12. It is configured. The outside air intake duct is disposed on the suction side of the electric fan, and is configured to take in outside air by the suction force of the electric fan when the damper is opened. In addition to maintaining the indoor air quality, the damper opens greatly when the outside air temperature is lower than the room temperature when the air conditioning system 1 is in the cooling mode. Thereby, the heat load of a refrigerator is reduced and the power consumption of the air conditioning system 1 is reduced.

  The cold heat source device 3 is a so-called refrigerator including an evaporator, a condenser, an expansion valve, and a compressor. However, it goes without saying that the present invention can be applied even if the principle and form are different, such as an absorption refrigerator. The cold heat source device 3 removes the heat of the heat medium flowing from the secondary side equipment 2 with an evaporator as a heat medium cooler. The heat removed by the evaporator is finally radiated from the cooling tower 10. The cold heat source device 3 can generate a heat medium having a temperature capable of sufficiently cooling indoor air.

  The integrated controller 13 is connected to the controllers 12A to 12C installed in the field by instrumentation signals such as communication, and controls the overall control of the air conditioning system based on measurement data sent from each controller. That is, the integrated controller 13 calculates optimal operating conditions and the like of the air conditioning system 1 based on measurement data and the like sent from each controller installed on the site, and notifies each controller of the calculated control target value and the like. As will be described later, the integrated controller 13 holds data such as a map necessary for calculating an optimum operating condition in a storage medium such as a hard disk.

The controller 12A is connected to a sensor capable of measuring the temperature of the outside air and the absolute humidity of the outside air, and notifies the integrated controller 13 of the measured temperature and humidity data. The controller 12B is connected to a two-way valve 14 (flow rate adjustment valve) disposed on the downstream side of the secondary side equipment 2 and capable of adjusting the opening degree by an instrumentation signal such as communication. By transmitting to the valve 14, the flow rate of the heat medium flowing in the coil of the secondary equipment 2 is controlled in accordance with the command from the integrated controller 13 or the like, and the room temperature is adjusted. The controller 12C is connected to the flow rate sensor 15 and the temperature sensor 16 arranged on the upstream side of the return header 4 by instrumentation signals such as communication, and receives the instrumentation signals from these sensors, so that the secondary equipment The flow rate and temperature of the heat medium (return water) flowing from 2 to the cold heat source device 3 can be measured. Further, the controller 12C (corresponding to the heat medium control means in the present invention) is connected to the pressure sensor 17 disposed in the pump outlet header 8 by an instrumentation signal such as communication, and the instrumentation from these sensors. By receiving the signal, the outlet pressure (water supply pressure) of the secondary pump 7 can be measured. The controller 12C connects the inverter that controls the rotational speed of the secondary pump 7, the control unit of the cold heat source device 3, the pump inlet header 6 and the pump outlet header 8, and the pressure difference of the heat medium between the headers. Is connected to the pressure regulating valve 18 for adjusting the instrument by an instrumentation signal such as communication, and the operation of these instruments is controlled by transmitting the instrumentation signal to these instruments. The pressure adjusting valve 18 is used when the pressure of the pump outlet header 8 cannot be adjusted even by controlling the rotational speed of the secondary pump 7.

<Operation flow of air conditioning system>
Next, an operation flow of the air conditioning system 1 will be described. FIG. 2 is an operation flow diagram of the air conditioning system 1. Hereinafter, the operation of the air conditioning system 1 will be described with reference to the flowchart of FIG. In the following operation flow, the description will be made on the assumption that the operation is in the cooling mode unless otherwise specified. As shown in FIG. 2, the operation flow of the air conditioning system 1 is roughly composed of a water supply pressure calculation step and a water supply temperature calculation step.

  (Step S101: Data Collection) When the air conditioning system 1 is activated, the integrated controller 13 collects operation data from each controller 12. That is, the integrated controller 13 collects the data of the outside air temperature and the outside absolute humidity from the controller 12A, collects the data of the opening degree of the two-way valve 14 from the controller 12B, and the flow rate and pressure of the return water and the water supply from the controller 12C. Collect pressure data.

(Step S102: Calculation of Required Lift) Next, the integrated controller 13 calculates the required lift of the heat medium from the current operating state of each device by the following formula. That is, the integrated controller 13 divides the flow rate of the return water by the rated flow rate of the secondary pump 7 and calculates the load factor of the pump. Next, the required head P0 is obtained by adding the head pressure of the heat medium circulation system (pressure by a head tank not shown) to the pump head calculated based on the minimum head, the rated head, and the load factor of the secondary pump 7. (An example of a parameter corresponding to the required state quantity in the present invention) is calculated.
(Formula-1) Pump load factor = Load flow rate / Pump rated load flow rate (Formula-2) Required lift P0 = Pump lift + Head pressure
= Minimum head + (Rated head-Minimum head) x Load factor ² + Head pressure

(Step S103: Correction with Opening of Two-Way Valve) Next, the integrated controller 13 sets the required head P0 calculated in step S102 in order to prevent excess or deficiency in the heat medium flowing to the secondary side equipment 2. Correction is made based on the opening of the two-way valve 14. That is, when the opening degree of the most open valve out of the three two-way valves 14 exceeds the upper limit value, the integrated controller 13 adds the correction value to the required lift P0 and corrects the required lift P1. And This process is provided in order to prevent the flow rate of the heat medium from increasing even if the opening degree of the two-way valve 14 is increased and the room temperature becoming uncontrollable. This is a process provided to compensate the head required for the flow rate control. Therefore, the upper limit here is the minimum lift required for the two-way valve 14 to control the flow rate of the heat medium. For example, an empirical rule or the like when the air conditioning system 1 is installed on the site or after a trial run. This is a value (field adjustment value) determined and set by. If the opening degree of the most opened valve does not exceed the upper limit value, the integrated controller 13 sets the required lift P0 calculated in step S102 as the required lift P1. Further, the correction value is appropriately adjusted based on an empirical rule or the like.
(Conditional expression) If (maximum value of the two-way valve opening> upper limit value) is true, the required lift P1 = required lift P0 + correction value

  (Step S104: Outside Air Temperature Check) Next, the integrated controller 13 determines that the required head P1 determined in step S103 is the minimum required head (the predetermined lower limit feed in the present invention) determined based on the outside air temperature. This is an example of a parameter corresponding to the pressure). If it is lower, the minimum required head is set as the required head P1 (S104 ′). Usually, when the outside air temperature becomes high, the heat input to the room also increases, so the flow rate of the heat medium required by the secondary side equipment 2 increases. Therefore, the minimum required head here is the minimum required determined based on the design specifications of the equipment in order to secure the required heat medium flow rate of the secondary equipment 2 estimated from the outside air temperature in advance. The head is a value set in advance in the integrated controller 13.

  (Step S105: Outside Air Absolute Humidity Check) Next, the integrated controller 13 determines that the required head P1 determined in Step S104 is the minimum required head (determined according to the present invention) determined based on the outside air absolute humidity. This is an example of a parameter corresponding to the lower limit feed pressure). If it is lower, the minimum required lift is set as the required lift P1 (S105 ′). The minimum required head here is determined based on the design specifications of the equipment in order to secure in advance the estimated heat medium flow rate required to dehumidify the room when outside air is taken in from the outside air intake duct. This is the minimum required head and is a value preset in the integrated controller 13. This lift is defined by a map as shown in FIG. 3 set in advance in the integrated controller 13, and when checking whether or not the required lift P1 determined in step S104 satisfies the map conditions. It becomes the standard. The map in Fig. 3 is set so that the water supply pressure decreases when the outside air's absolute humidity increases. When the outside air's absolute humidity is 0.012kg / kg or more, the water supply pressure is Px1, and the outside air's absolute humidity is 0.015kg / kg. In the above case, Px2 where the water supply pressure is lower than Px1 is shown. This is because, when the outdoor air absolute humidity is high, the water pressure is lowered and the flow rate of the heat medium is lowered so that more heat is exchanged in the coil of the secondary equipment 2 and the evaporator of the cold heat source equipment 3. Based on the technical idea of

  (Step S106: Return Water Temperature Check) Next, the integrated controller 13 determines that the necessary head P1 determined in the above step S105 is the minimum required head determined based on the return water temperature (predetermined in the present invention). This is an example of a parameter corresponding to the lower limit feed pressure). If it is lower, the minimum required lift is set as the required lift P1 (S106 ′). If the pump head is low, the circulation of the heat medium is delayed, the return water temperature becomes high, and the outlet temperature of the refrigerator is prevented from becoming higher than the target value. That is, since there is little heat load, if the pump head is lowered to lower the flow rate of the heat medium, the flow of the heat medium flowing through the coil becomes slower, and the temperature of the return water becomes higher. When the temperature of the return water increases, the outlet temperature of the refrigerator cannot maintain the target value if the water supply flow rate of the primary pump 5 is constant. If the flow rate of the heat medium is too slow, the amount of heat that can be transported decreases, and the amount of heat that should be transported from the secondary equipment 2 to the cold heat source device 3 cannot be transported sufficiently. Therefore, the minimum necessary head mentioned here is the minimum necessary head determined based on the design specifications of the equipment in order to secure the necessary heat transport amount estimated from the return water temperature in advance. This value is preset in the integrated controller 13.

(Step S107: Determination of Water Supply Pressure) The integrated controller 13 sets the necessary head P1 finally determined through a series of processes from Step S102 to Step S106 as the water supply pressure P. Which of the lower limit values 1 to 3 is adopted as the water supply pressure is selected according to the equipment characteristics as the parameter most effective for the load of the air-conditioning target facility. In addition, there is a parameter whose importance changes depending on the season such as the absolute humidity of the outside air, and the priority order of the lower limit values 1 to 3 may be reviewed every time. The water supply pressure P is a control target value for the outlet pressure of the secondary pump 7. In addition, in the process of steps S104 to 106, the necessary head P1 is checked in the order of the outside air temperature, the outside air humidity, and the return water temperature in order to preferentially check the parameters with high importance of the air conditioning load. .

(Step S108: Calculation based on outside air temperature) Next, the integrated controller 13 determines the temperature of the heat medium (water supply temperature) from the current operation state of each device by the following steps. That is, the integrated controller 13 determines the water supply temperature T1 (a parameter corresponding to the required state quantity in the present invention) from the map shown in the following table stored in advance in the storage device based on the outside air temperature data notified from the controller 12A. Is an example). The limit value indicated by the map corresponds to a predetermined temperature condition in the present invention.
(Conditional Expression) If (outside air temperature> limit value n1) is true, the water supply temperature when the water supply temperature T1 = the limit value n1

(Step S109: Calculation with absolute outside air humidity) Next, the integrated controller 13 uses a map shown in the following table stored in advance in the storage device based on the outside air absolute humidity data notified from the controller 12A. To decide.
(Conditional Expression) If (absolute air humidity> limit value n2) is true, the water supply temperature when the water supply temperature T2 = the limit value n2

  As shown in the table above, the water supply temperature is set to decrease as the outside air absolute humidity increases. This is based on the technical idea that the dehumidifying ability of the coil of the secondary side equipment 2 is increased by lowering the water supply temperature and lowering the temperature of the heat medium when the outdoor air absolute humidity is high.

(Step S110: Calculation with load flow rate) Next, the integrated controller 13 calculates the water supply temperature T3 from the map shown in the following table stored in advance in the storage device based on the data of the return water flow rate notified from the controller 12C. decide.
(Conditional expression) If (Load flow rate> Limit value n3) is true, the water supply temperature when T3 = Limit value n3

(Step S111: Calculation based on the two-way valve opening degree) Next, the integrated controller 13 uses the following table stored in advance in the storage device based on the valve opening degree data of the two-way valve 14 notified from the controller 12B. The water supply temperature T4 is determined from the map shown in FIG.
(Conditional Expression) If (two-way valve opening> limit value n4) is true, the water supply temperature when the water supply temperature T4 = the limit value n4

(Step S112: Calculated with the return water temperature) Next, the integrated controller 13 based on the return water temperature data notified from the controller 12C, the water supply temperature T5 from the map shown in the following table stored in advance in the storage device. To decide. In the map shown in the following table, there is a one-to-one correspondence between the return water temperature and the water supply temperature, but a plurality of correspondence relationships between the return water temperature and the water supply temperature are defined according to the water supply pressure P. It depends on the value of the water supply pressure P determined in step S107.
(Conditional Expression) If (absolute air humidity> limit value n5) is true, the water supply temperature when T5 = limit value n5

  (Step S113: Determination of Water Supply Temperature) The integrated controller 13 sets the minimum value among the five water supply temperatures (T1 to T5) determined through the processing from Step S108 to Step S112 as the water supply temperature T. The water supply temperature T is a control target value for the outlet temperature of the cold heat source device 3. In addition, when the cold heat source apparatus 3 is a boiler etc. and warm heat is supplied to the secondary side equipment 2 (that is, when an air-conditioning system is in heating mode), the water supply temperature T is the water supply temperature (T1 to T5). To the maximum value.

  (Step S114: Check Lower Limit at Water Supply Temperature) Next, the integrated controller 13 determines the lowest water supply pressure P determined at Step S107 based on the final water supply temperature T determined at Step S113. It is checked whether or not it is below the minimum necessary head, and if it is below, the minimum head is set as the necessary head P1 (step S114 ′), and then the processing from step S107 to step S113 is performed again. . The minimum required head mentioned here is the minimum pump head required for efficient heat exchange of the heat medium at the temperature T between the secondary equipment 2 and the cold heat source equipment 3, and the design of the equipment. The value is determined based on the specification and the like, and is preset in the integrated controller 13.

(Step S115: Determination of water supply pressure P and water supply temperature T) When the integrated controller 13 confirms that the water supply pressure P does not fall below the required head determined based on the water supply temperature T in Step S114, Step S107 is performed. And the water supply pressure P and the water supply temperature T determined by the process of step S113 are finally determined as the control target values of each device, and notified to the controller 12C. The controller 12C notified of the control target value from the integrated controller 13 adjusts the rotation speed of the pump by controlling the inverter of the secondary pump 7 so that the pressure of the pump outlet header 8 becomes the water supply pressure P. In addition, the controller 12C notifies the cooling heat source device 3 of the water supply temperature T as a control target value. The cold heat source device 3 notified of the water supply temperature T from the controller 12C controls the heat medium so that the heat medium temperature at the evaporator outlet becomes the water supply temperature T by adjusting the vane opening degree and the like.

<Effect of air conditioning system>
As mentioned above, according to the said air conditioning system 1, since the heat medium of the minimum flow volume which the secondary side installation 2 requires is supplied with the secondary pump 7, it is possible to reduce the power consumption of a pump. is there. When the flow rate of the heat medium required by the secondary side equipment 2 is small, such as in spring or autumn, the pump discharge flow rate tends to be excessive, but the rotation speed of the pump according to the required heat medium flow rate of the secondary side equipment 2 Therefore, the power consumption can be greatly reduced. Further, according to the air conditioning system 1, since the minimum required pressure and temperature of the heat medium determined based on parameters such as the outside air temperature are checked, the rotational speed of the pump for the purpose of reducing power consumption. Even if it is reduced, it is possible to avoid a situation where the flow of the heat medium is insufficient. That is, according to the air conditioning system 1, since the control target value of the water supply pressure and the water supply temperature of the cold / hot heat source water is variably controlled based on the operation state on the load side, the heat load of each room is appropriately processed. Thus, it is possible to reduce the energy consumption of the facility while keeping the indoor environment in an appropriate state.

  Here, the operation of the damper of the outside air intake duct will be supplementarily described. FIG. 4 is an air diagram showing conditions when the damper of the outside air intake duct is opened in the outside air cooling. Even when the outside air is taken in for the purpose of reducing the cooling load, it is necessary to perform dehumidification if the absolute humidity of the outside air is too high, and humidification if it is too low. Since a new amount of air-conditioning heat is required to perform humidification and dehumidification, the air-conditioning system 1 according to the present embodiment can take in outside air when the outside air temperature and humidity are within the area indicated by the oblique lines in FIG. Increases thermal efficiency.

  The air conditioning system 1 has a system configuration in which the integrated controller 13 supervises the plurality of controllers 12. However, the present invention is not limited to such an embodiment, and one control device is used for all the controllers. The devices may be controlled collectively.

The block diagram of an air-conditioning system. The operation | movement flowchart of an air conditioning system. A map showing the relationship between the absolute humidity of outside air and the required head. Air line diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Air conditioning system 2 ... Secondary side equipment 3 ... Cold heat source equipment 4 ... Return header 5 ... Primary pump 6 ... Pump inlet header 7 ... Secondary pump 8 ... · Pump outlet header 9 ··· Cooling water circulation pump 10 · · Cooling tower 11 · · Bypass piping 12A, B, C · · Controller 13 · · Integrated controller 14 · · Two-way valve 15 · · Flow sensor 16 · · Temperature sensor 17. Pressure sensor 18 Pressure adjusting valve

Claims (6)

An air conditioning system that regulates indoor air,
An air conditioner for adjusting the indoor air;
A heat source unit that supplies cold air or hot air to the air conditioner by adjusting the air in the room by pumping a heat medium to the air conditioner;
Control target value determining means for determining a control target value of a state quantity of the heat medium pumped to the air conditioner based on an air state quantity adjusted by the air conditioner;
Heat medium control means for controlling the state quantity of the heat medium pressure-fed to the air conditioner so that the state quantity of the heat medium pressure-fed to the air conditioner becomes the control target value determined by the control target value determination means; With
The control target value determining means includes
Based on the state quantity of air adjusted by the air conditioner, estimate a required state quantity that is a state quantity of the heat medium required for the air conditioner to adjust the air,
When the estimated required state quantity satisfies a predetermined condition set in advance to ensure the air conditioning capability of the air conditioner, the estimated required state quantity is determined as the control target value,
When the estimated required state quantity does not satisfy the predetermined condition, a predetermined state quantity that satisfies the predetermined condition is determined as the control target value.
Air conditioning system. A flow rate detecting means for detecting a flow rate of the heat medium whose flow rate is adjusted by the air conditioner;
A flow rate adjusting means for adjusting the flow rate of the heat medium sent from the heat source unit to the air conditioner according to the amount of heat used by the air conditioner to adjust the indoor air;
The control target value determining means includes
Based on the detection result of the flow rate detecting means, the feeding pressure of the heat medium required for the air conditioner to adjust the air is estimated as the required state quantity,
A predetermined lower limit feed pressure set in advance to ensure the flow rate adjustment capability of the heat medium in the air conditioner is set as the predetermined condition, and the estimated when the estimated feed pressure is equal to or greater than the predetermined lower limit feed pressure Determining the feed pressure as the control target value;
When the estimated feed pressure is less than the predetermined lower limit feed pressure, a predetermined feed pressure equal to or higher than the predetermined lower limit feed pressure is determined as the control target value,
The heating medium control means controls the feeding pressure of the heating medium to be fed to the air conditioner so that the feeding pressure of the heating medium to be fed to the air conditioner becomes the control target value determined by the control target value determining means. To
The air conditioning system according to claim 1. The predetermined lower limit feed pressure is estimated from the heat balance in the room where the air conditioner adjusts the air, and ensures the flow rate of the heat medium required for the air conditioner to adjust the air in the room. Is the pressure to
The air conditioning system according to claim 2. The control target value determining means includes
Based on the state quantity of air adjusted by the air conditioner, the heating medium feed temperature required for the air conditioner to adjust the air is estimated as the required state quantity,
The predetermined temperature condition set in advance to ensure the air conditioning capability of the air conditioner is set as the predetermined condition, and when the estimated feed temperature satisfies the predetermined temperature condition, the estimated feed temperature is Determine as the control target value,
If the estimated feed temperature does not satisfy the predetermined temperature condition, a predetermined feed temperature satisfying the predetermined temperature condition is determined as the control target value,
The heating medium control means controls the feeding temperature of the heat medium pressure-fed to the air conditioner so that the feed temperature of the heat medium pressure-fed to the air conditioner becomes the control target value determined by the control target value determination means. To
The air conditioning system according to any one of claims 1 to 3. The predetermined temperature condition is estimated from the heat balance amount of the room where the air conditioner adjusts the air, and secures the amount of cold or hot heat required for the air conditioner to adjust the air in the room. Is the temperature to do,
The air conditioning system according to claim 4. The amount of heat balance in the room is the outside air temperature, the outside air humidity, the pressure of the heat medium, the flow rate of the heat medium, the temperature of the heat medium, the control parameters in the air conditioner, and the temperature of the heat medium emitted from the air conditioner. A physical quantity including any of the following:
The air conditioning system according to claim 3 or 5.

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