JP2014035100A - Air conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly keep a flow rate of a heat medium in a heat medium circuit at a proper flow rate by properly controlling rotational frequencies of secondary side pumps.SOLUTION: Primary side pumps 44a-44c are respectively connected between an outlet side of each of utilization units 30a-30c and an inlet side of each of chiller units 20a-20c, and distribute water flowing out from utilization-side heat exchangers 33a-33c to the chiller units 20a-30c. Invertor drive-type secondary pumps 46 and 47 are respectively connected between an outlet side of each of the chiller units 20a-20c and an inlet side of each of the utilization units 30a-30c, and distribute the water from the chiller units 20a-20c to utilization-side heat exchangers 33a-33c. A memory 81 memorizes a feed water pressure model 81a of the secondary side pumps 46 and 47. A CPU 82 controls rotational frequencies of the secondary side pumps 46 and 47 by using the feed water pressure model 81a so that a feed water pressure of the secondary side pumps 46 and 47 becomes equal to a target pressure, and corrects the feed water pressure model 81a on the basis of a value of the total flow rate Q of the water after the change of the target pressure.

Description

  The present invention relates to an air conditioning system.

  As a system for heating or cooling air in an air-conditioning target space, for example, a system disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-106731) is known. In the system according to Patent Document 1, a heat medium circuit is configured by sequentially connecting a primary side pump, a refrigerator, a secondary side pump, a flow control valve, a heat exchanger, and the like. In this heat medium circuit, water as a heat medium circulates. The air is heated or cooled by heat exchange between water as a heat medium in the heat medium circuit and air in the air-conditioning target space in the heat exchanger.

  In the system according to Patent Document 1, the water supply pressure of the secondary pump is determined by calculation using a function having the flow rate of water in the heat medium circuit as a variable. The rotation speed control of the secondary pump is performed using the determined water supply pressure of the secondary pump. For this reason, if the calculation of the water supply pressure of the secondary pump is not performed appropriately, the rotational speed control of the secondary pump will be adversely affected.

  Accordingly, an object of the present invention is to appropriately control the rotational speed of the secondary side pump and maintain the flow rate of the heat medium in the heat medium circuit at an appropriate flow rate.

  An air conditioning system according to a first aspect of the present invention includes a heat source device, a plurality of utilization units, a primary side pump, a secondary side pump, a storage unit, and a control unit. The heat source machine heats or cools the heat medium. Each of the plurality of utilization units has a heat exchanger and a fan. The heat exchanger causes heat exchange between the heat medium and air to heat or cool the air. The fan supplies heated or cooled air to the air-conditioning target space. The primary side pump is connected on the first pipe and sends the heat medium flowing out from each heat exchanger to the heat source unit. The 1st piping is piping which connects the exit side of each utilization unit, and the entrance side of a heat source machine. The secondary pump is an inverter-driven pump, is connected on the second pipe, and sends the heat medium flowing out from the heat source unit to each heat exchanger. The 2nd piping is piping which connects the exit side of a heat source machine, and the entrance side of each utilization unit. The storage unit stores a water supply pressure model of the secondary pump. The water supply pressure model of the secondary pump is a model represented by a function having the total flow rate of the heat medium flowing out from each utilization unit as a variable. A control part controls the rotation speed of a secondary side pump using a water supply pressure model so that the water supply pressure of a secondary side pump turns into target pressure. Then, the control unit changes the target pressure and corrects the water supply pressure model based on the value of the total flow rate of the heat medium after the change of the target pressure.

  According to this air conditioning system, the water supply pressure model used for controlling the rotational speed of the secondary pump is corrected based on the value of the total flow rate of the heat medium after the target pressure is changed. For this reason, the rotational speed control of the secondary pump is performed using a water supply pressure model suitable for an actual heat medium circuit. Therefore, the rotational speed control of the secondary pump can be performed more appropriately, and the flow rate of the heat medium in the heat medium circuit can be maintained at an appropriate flow rate.

  The air conditioning system which concerns on the 2nd viewpoint of this invention is an air conditioning system which concerns on a 1st viewpoint, Comprising: The control part is a heat medium before and behind the change of the value of the total flow volume of the heat medium before the change of a target pressure, and a target pressure. The ratio with the amount of change in the total flow rate is obtained. And a control part correct | amends a water supply pressure model, when a ratio is higher than predetermined value.

  Ideally, the value of the total flow rate of the heat medium before the change of the target pressure is substantially equal to the value of the total flow rate of the heat medium after the change of the target pressure. Therefore, ideally, the ratio between the value of the total flow rate of the heat medium before the change of the target pressure and the change amount of the value of the total flow rate of the heat medium before and after the change of the target pressure is equal to or less than a predetermined value. However, if the water supply pressure model does not conform to the actual heat medium circuit, appropriate rotation speed control will not be performed for the secondary pump, so the total flow rate value of the heat medium before the target pressure change and the target The ratio with the amount of change in the value of the total flow rate of the heat medium before and after the pressure change becomes higher than a predetermined value. However, this air conditioning system corrects the water supply pressure model when the ratio is higher than a predetermined value. Therefore, the air conditioning system can appropriately determine whether or not the water supply pressure model is corrected, and can perform correction of the model when necessary.

  The air conditioning system according to the third aspect of the present invention is the air conditioning system according to the first aspect or the second aspect, and the function representing the water supply pressure model includes a plurality of parameters in addition to the total flow rate of the heat medium. . Then, the control unit corrects at least one of the parameters included in the water supply pressure model based on the value of the total flow rate of the heat medium after the change of the target pressure.

  The parameters included in the water supply pressure model affect the rotational speed control of the secondary pump. Since this air conditioning system corrects at least one of these parameters, the rotational speed control of the secondary pump can be performed more accurately.

  An air conditioning system according to a fourth aspect of the present invention is the air conditioning system according to the third aspect, and the storage unit stores a plurality of water supply pressure models. The water supply pressure model is a model in which at least one of the parameters is different from each other. The correction of the water supply pressure model by the control unit is performed by selecting one of the plurality of water supply pressure models based on the value of the total flow rate of the heat medium after the change of the target pressure.

  Thereby, correction of a water supply pressure model is easily performed.

  The air conditioning system which concerns on the 5th viewpoint of this invention is an air conditioning system which concerns on either of the 1st viewpoint to the 4th viewpoint, Comprising: When a 1st predetermined time passes since a control part changed target pressure. The value of the total flow rate of the heat medium is used to correct the water supply pressure model.

  Although the value of the total flow rate of the heat medium changes by changing the target pressure, it eventually becomes a stable value. Therefore, when the value of the total flow rate of the heat medium immediately after changing the target pressure is used for correction of the water supply pressure model, the model is corrected using the value of the total flow rate of the unstable heat medium. . However, in this air conditioning system, the value of the total flow rate of the heat medium when the first predetermined time has elapsed since the target pressure was changed is used for correction of the water supply pressure model. Therefore, the value of the stable total flow rate of the heat medium is used for correcting the water supply pressure model. Therefore, since a more appropriate correction of the water supply pressure model is made, more accurate control of the rotational speed of the secondary pump and the like is performed.

  The air conditioning system which concerns on the 6th viewpoint of this invention is an air conditioning system which concerns on either of the 1st viewpoint to the 5th viewpoint, Comprising: A control part changes a target pressure for every 2nd predetermined time interval.

  As described above, the value of the total flow rate of the heat medium changes by changing the target pressure, but eventually becomes a stable value. Therefore, if the target pressure is further changed while the value of the total flow rate of the heat medium is not yet stable, the value of the total flow rate of the heat medium may be hunted. However, in this air conditioning system, the operation for changing the target pressure is performed at a sufficient time interval, so that it is possible to prevent the value of the total flow rate of the heat medium from hunting. Therefore, more accurate control of the rotation speed of the secondary pump is performed.

  According to the air conditioning system according to the first aspect of the present invention, the rotational speed control of the secondary pump can be performed more appropriately, and the flow rate of the heat medium in the heat medium circuit can be maintained at an appropriate flow rate.

  According to the air conditioning system according to the second aspect of the present invention, whether or not the water supply pressure model is corrected is appropriately determined, and the model is corrected when necessary.

  According to the air conditioning system according to the third aspect of the present invention, the rotational speed control of the secondary pump is more accurately performed.

  According to the air conditioning system according to the fourth aspect of the present invention, the correction of the water supply pressure model is easily performed.

  According to the air conditioning system according to the fifth aspect of the present invention, more appropriate water supply pressure model correction is performed, so that more accurate control of the rotation speed of the secondary pump and the like is performed.

  According to the air conditioning system according to the sixth aspect of the present invention, the target pressure changing operation is performed at a sufficient time interval, so that the value of the total flow rate of the heat medium can be prevented from hunting. Therefore, more accurate control of the rotation speed of the secondary pump is performed.

1 is a schematic configuration diagram of an air conditioning system according to an embodiment of the present invention. The schematic block diagram of a chiller unit. The wet air diagram which shows air cooling and dehumidification at the time of air_conditioning | cooling dehumidification driving | operation. The humid air line figure which shows air cooling and humidification at the time of air_conditioning | cooling humidification driving | operation. The humid air line figure which shows the heating and dehumidification of air at the time of a dehumidification heating driving | operation. The humid air line figure which shows the heating and humidification of the air at the time of humidification heating operation. The block diagram which shows typically the various apparatuses connected to the air-conditioning system controller, and the inside of this controller. The graph showing a water supply pressure model. The conceptual diagram showing the some water supply pressure model memorize | stored in memory. The graph showing the characteristic of a secondary side pump. The graph for demonstrating how water supply pressure and the valve opening degree of a use side valve are determined. The graph for demonstrating the process of the change of various control and the flow volume of water at the time of changing a target pressure. The graph which represented the time-dependent change of the total flow rate of the water when a target pressure changes for every elapse of 2nd predetermined time divided into the case where a water supply pressure model is adapted, and the case of nonconformity. The figure for demonstrating correction | amendment operation | movement of the water supply pressure model which concerns on this embodiment.

  Hereinafter, an air conditioning system according to the present invention will be described in detail with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.

(1) Overall Configuration of Air Conditioning System FIG. 1 is a schematic configuration diagram of an air conditioning system 10 according to an embodiment of the present invention. The air conditioning system 10 can supply air adjusted to an optimum temperature into the air conditioning target space while performing an optimal control operation that minimizes power consumption of the entire system 10. The air conditioning system 10 is mainly installed in relatively large buildings such as buildings, factories, hospitals, and hotels.

  Such an air conditioning system 10 mainly includes a chiller unit group 20, a utilization unit group 30, primary side pumps 44a to 44c, secondary side pumps 46 and 47, and an air conditioning system controller, as shown in FIGS. 80. A refrigerant circuit 21 shown in FIG. 2 is formed inside the plurality of chiller units 20a, 20b, and 20c constituting the chiller unit group 20. Further, as shown in FIG. 1, the chiller unit group 20 is also connected to a cooling tower 70, and a heat dissipation circuit 60 is configured by these. As shown in FIG. 1, the heat medium circuit 40 is configured by the primary pumps 44a and 44c, the chiller unit group 20, the secondary pumps 46 and 47, the utilization unit group 30, and the like.

(2) Detailed configuration of air conditioning system (2-1) Chiller unit group and refrigerant circuit The chiller unit group 20 according to the present embodiment includes a plurality of chiller units 20a to 20c (corresponding to heat source devices). Each chiller unit 20a-20c is mutually connected in parallel, and contains the refrigerant circuit 21 shown in FIG.

  The refrigerant circuit 21 is configured by sequentially connecting a compressor 22, a radiator 23, a chiller side expansion valve 24, an evaporator 25, and the like. The refrigerant circuit 21 is filled with a refrigerant.

  The compressor 22 can adjust the operating capacity. Electric power is supplied to the motor of the compressor 22 via an inverter. When the output frequency of the inverter is changed, the rotational speed of the motor, that is, the rotational speed is changed, and the operating capacity of the compressor 22 changes.

  The radiator 23 has a first heat transfer tube connected to the refrigerant circuit 21 and a second heat transfer tube connected to the heat dissipation circuit 60. The radiator 23 exchanges heat between the refrigerant flowing in the first heat transfer tube on the refrigerant circuit 21 side and the heat medium flowing in the second heat transfer tube on the heat dissipation circuit 60 side.

  The chiller side expansion valve 24 is for depressurizing the refrigerant in the refrigerant circuit 21 and flowing out the depressurized refrigerant, and is constituted by an electric expansion valve.

  The evaporator 25 has a first heat transfer tube connected to the refrigerant circuit 21 and a second heat transfer tube connected to the heat medium circuit 40. The evaporator 25 exchanges heat between the refrigerant flowing in the first heat transfer tube on the refrigerant circuit 21 side and the heat medium flowing in the second heat transfer tube on the heat medium circuit 40 side.

  Each chiller unit 20a-20c including such a refrigerant circuit 21 cools or heats water as a heat medium.

(2-2) Heat Dissipation Circuit The heat dissipation circuit 60 is filled with water as a heat medium. The heat dissipation circuit 60 is mainly configured by sequentially connecting the radiator 23, the water pump 61, and the cooling tower 70 in each of the chiller units 20 a to 20 c. The water pump 61 can adjust the discharge flow rate and circulates the water in the heat dissipation circuit 60. In the cooling tower 70, water circulating in the heat dissipation circuit 60 is cooled.

  In FIG. 1, the arrow attached to the water pump 61 represents the direction of water flow in the heat dissipation circuit 60.

(2-3) Heat medium circuit The heat medium circuit 40 constitutes a closed circuit filled with water as a heat medium. The heat medium circuit 40 mainly includes primary side pumps 44a, 44b, and 44c, an evaporator 25 in each of the chiller units 20a to 20c, a flow rate adjusting valve 45, secondary side pumps 46 and 47, and a use unit group. The use side valves 32a, 32b, and 32c and the use side heat exchangers 33a, 33b, and 33c (corresponding to heat exchangers) in the use units 30a, 30b, and 30c constituting the structure 30 are sequentially connected. Has been.

  The primary side pumps 44a to 44c are connected on a pipe L1 (corresponding to a first pipe) that connects the outlet side of each of the utilization units 30a to 30c and the inlet side of each of the chiller units 20a to 20c. More specifically, the pipe L1 connects the outlet side of each usage side valve 32a to 32c, which is the outlet side of each usage unit 30a to 30c, to the return header 41 in a state of being joined once, and the header 41 It is connected to each chiller unit 20a-20c via. Three primary pumps 44a to 44c are provided between the return header 41 and each chiller unit 20a to 20c, corresponding to each chiller unit 20a to 20c. The primary pumps 44a to 44c are metering pumps, and are driven and controlled by an air conditioning system controller 80 described later. Such primary side pumps 44a to 44c, as shown by the arrows attached to the primary side pumps 44a to 44c in FIG. 1, receive water as a heat medium flowing out from the respective use side heat exchangers 33a to 33c. The water in the heat medium circuit 40 is circulated by sending it to the chiller units 20a to 20c.

  In the evaporator 25, the water circulating in the heat medium circuit 40 is cooled, for example.

  The flow rate adjustment valve 45 adjusts the flow rate of water flowing through the chiller unit 20a. That is, the flow rate of water flowing through the chiller unit 20 a is determined by the opening degree of the flow rate control valve 45.

  The secondary pumps 46 and 47 are connected to a pipe L2 (corresponding to a second pipe) that connects the outlet side of each chiller unit 20a to 20c and the inlet side of each usage unit 30a to 30c. More specifically, the pipe L2 connects the outlet side of each chiller unit 20b, 20c via the first feed header 42 and the second feed header 43 to the usage side heat exchangers 33a to 33c in the usage units 30a to 30c. It is connected to the entrance side. Two secondary pumps 46 and 47 are provided on the pipe L2 and between the first feed header 42 and the second feed header 43, corresponding to the chiller units 20b and 20c. Unlike the primary side pumps 44 a to 44 c, the secondary side pumps 46 and 47 are variable capacity type pumps capable of adjusting the capacity and adjusting the discharge capacity, and are driven by an inverter by the air conditioning system controller 80. Is done. Such secondary pumps 46 and 47, as shown by the arrows attached to the secondary pumps 46 and 47 in FIG. 1, water as a heat medium flowing out from the chiller units 20b and 20c, The water in the heat medium circuit 40 is circulated by sending it to each use side heat exchanger 33a-33c.

  The usage side valves 32a to 32c and the usage side heat exchangers 33a to 33c in the usage units 30a, 30b, and 30c will be described in “(2-4) Usage unit group”.

  Furthermore, one flow meter 48 is attached to the heat medium circuit 40 according to the present embodiment. The flow meter 48 is a part of the pipe L1 on which water that has flowed out from the use units 30a to 30c flows and is attached to the front side of the return header 41. That is, the flow meter 48 measures the total flow rate Q of water circulating in the heat medium circuit 40.

(2-4) Utilization unit group The utilization unit group 30 is comprised by several utilization unit 30a, 30b, 30c. Each utilization unit 30a, 30b, 30c is installed in the same or different air conditioning target space.

  Each utilization unit 30a-30c has a substantially rectangular parallelepiped casing 31a-31c. Air passages through which air flows are formed in the respective casings 31a to 31c. One end of a suction duct (not shown) is connected to the inflow end of the air passage, and one end of an air supply duct (not shown) is connected to the outflow end of the air passage. The other ends of the suction duct and the air supply duct are each connected to the air-conditioning target space.

  Inside each casing 31a-31c, in addition to the use side valves 32a-32c and the use side heat exchangers 33a-33c constituting the heat medium circuit 40, electric heaters 34a, 34b, 34c, watering type humidifiers 35a, 35b , 35c and blower fans 36a, 36b, 36c (corresponding to fans) are provided. In particular, in the air passages in the respective casings 31a to 31c, the use side heat exchangers 33a to 33b, the electric heaters 34a, 34b, and 34c, and the watering humidifiers 35a, 35b, and 35c are sequentially arranged from the upstream side toward the downstream side. And ventilation fans 36a, 36b, and 36c are provided.

  The use side valves 32a to 32c adjust the amount of water flowing to the use side heat exchangers 33a to 33c, respectively. That is, the flow rate of water in the use side heat exchangers 33a to 33c is determined by the opening degree of each of the use side valves 32a to 32c.

  The use side heat exchangers 33a to 33c heat or cool the air by exchanging heat between water and air. Specifically, the use side heat exchangers 33a to 33c are fin-and-tube heat exchangers having a plurality of heat transfer fins and a heat transfer tube penetrating the heat transfer fins. Water that circulates through the heat medium circuit 40 flows through the heat transfer tubes of the use side heat exchangers 33a to 33c, and the heat of the water is supplied to the air through the heat transfer tubes and the heat transfer fins, thereby heating the air. Or it is supposed to be cooled.

  The electric heaters 34a to 34c are devices for raising the temperature of the air. The electric heaters 34a to 34c can change the output stepwise, and can adjust the amount of heating of air.

  The watering type humidifiers 35a to 35c are connected to a tank (not shown) installed outside the casings 31a to 31c. The watering type humidifiers 35a to 35c humidify the air flowing in the casings 31a to 31c by spraying the water in the tank from the nozzles into the air. That is, the watering type humidifiers 35a to 35c are devices for increasing the humidity of the air and can adjust the amount of humidification to the air.

  The blower fans 36a to 36c are blowers that can change the rotational speed stepwise by inverter control and can adjust the blown amount of heated or cooled air. The blower fans 36a to 36c generate a flow of air that is blown into the air-conditioning target space through the use side heat exchangers 33a to 33c, the electric heaters 34a to 34c, and the watering type humidifiers 35a to 35c.

(2-5) Air Conditioning System Controller The air conditioning system controller 80 is for controlling the air conditioning system 10 in an integrated manner. The air conditioning system controller 80 will be described in detail later.

(3) Basic operation of the air conditioning system Next, the operation of the air conditioning system 10 will be described. The air conditioning system 10 includes a cooling and dehumidifying operation for cooling and dehumidifying air (FIG. 3), a cooling and humidifying operation for cooling and humidifying air (FIG. 4), and a heating and dehumidifying operation for dehumidifying and heating air (FIG. 3). 5) and heating / humidifying operation (FIG. 6) for heating and humidifying air can be performed. Thereby, the air conditioning system 10 can perform an air conditioning operation so that the temperature and humidity in the air-conditioning target space become 23 ° C. which is the set temperature and 50% which is the set humidity, for example.

(3-1) Cooling and Dehumidifying Operation In the cooling and dehumidifying operation shown in FIG. 3, the compressor 22, the various pumps 44a to 44c, 46, 47, 61, and the blower fans 36a to 36c are operated.

  In the cooling and dehumidifying operation, basically, the electric heaters 34a to 34c are stopped, and the watering of the watering humidifiers 35a to 35c is also stopped. In the cooling and dehumidifying operation, a refrigeration cycle is performed in the refrigerant circuit 21. Specifically, the refrigerant compressed by the compressor 22 dissipates heat into the water flowing through the heat dissipation circuit 60 and condenses in the radiator 23. The refrigerant cooled by the radiator 23 is depressurized by the chiller side expansion valve 24 and then evaporates by absorbing heat from the water flowing through the heat medium circuit 40 in the evaporator 25. The refrigerant evaporated in the evaporator 25 is sucked into the compressor 22 and compressed. The water flowing through the heat dissipation circuit 60 heated by the radiator 23 radiates heat to the outdoor air in the cooling tower 70. In the heat medium circuit 40, the water cooled by the evaporator 25 of the refrigerant circuit 21 cools the air flowing through the air passages in the casings 31a to 31c in the use side heat exchangers 33a to 33c. The water that has passed through the use side heat exchangers 33a to 33c returns to the evaporator 25 of the refrigerant circuit 21 and is cooled again. In the heat medium circuit 40, the cold heat obtained by the water from the refrigerant in the evaporator 25 is conveyed to the use side heat exchangers 33a to 33c and supplied to the air.

  In each utilization unit 30a-30c, as already stated, the indoor air taken in from indoor space by the suction duct (not shown) flows through the air passage in the casings 31a-31c. This air is cooled and dehumidified by the water in the heat medium circuit 40 in each of the use side heat exchangers 33a to 33c. The air cooled and / or dehumidified by each use side heat exchanger 33a to 33c is supplied to the indoor space as supply air via an air supply duct (not shown).

(3-2) Cooling / humidifying operation The cooling / humidifying operation shown in FIG. 4 is an operation in which humidification is performed by watering the watering-type humidifiers 35a to 35c in addition to the dehumidifying / cooling operation. Until the air is cooled and dehumidified by the water of the heat medium circuit 40 in each of the use side heat exchangers 33a to 33c, it is the same as the above-described cooling and dehumidifying operation, and each of the sprinkled water is supplied to the cooled and / or dehumidified air. Watering by the type humidifiers 35a to 35c is performed.

  With cooling and / or dehumidification by each of the use side heat exchangers 33a to 33c, the temperature of the supply air can reach a desired set temperature. However, this cooling / humidifying operation is performed when the humidity in the air-conditioning target space falls below a desired set humidity due to the dehumidifying effect accompanying cooling.

(3-3) Heating / Dehumidifying Operation The heating / dehumidifying operation shown in FIG. 5 is an operation called a reheat dehumidifying operation. In the dehumidification and / or cooling by the use side heat exchangers 33a to 33c, the humidity of the supply air can reach a desired set humidity. However, this heating and dehumidifying operation is performed when the temperature in the air-conditioning target space falls below a desired set temperature due to the cooling effect accompanying dehumidification.

  In the dehumidifying and heating operation, when the amount of cold supplied to the air for dehumidification is large in each of the use side heat exchangers 33a to 33c and the air is cooled more than necessary, the electric heaters 34a to 34c are activated. Reheat the air.

(3-4) Heating / humidifying operation In the heating / humidifying operation shown in FIG. 6, the electric heaters 34a to 34c, the watering humidifiers 35a to 35c, and the blower fans 36a to 36c are operated. On the other hand, the operation of the compressor 22 and the various pumps 44a to 44c, 46, 47, 61 is stopped.

  In the heating and humidifying operation, in each of the usage units 30a to 30c, the air taken in from the air-conditioning target space is first heated by the electric heaters 34a to 34c, and then heated by the watering humidifiers 35a to 35c. The air is supplied into the air-conditioned space.

(4) Detailed description about an air-conditioning system controller FIG. 7: is a block diagram which represents typically the internal structure of the air-conditioning system controller 80 which concerns on this embodiment, and the various apparatuses connected to this controller 80. As shown in FIG. As shown in FIG. 7, the air conditioning system controller 80 mainly includes a memory 81 (corresponding to a storage unit) and a CPU 82 (corresponding to a control unit), and includes chiller units 20a to 20c, use units 30a to 30c, Various pumps 44 a to 44 c, 46, 47, 61, a flow control valve 45 and a flow meter 48 are connected. The air conditioning system controller 80 controls the connected devices to perform the basic operation of the air conditioning system 10 described above.

  Note that the memory 81 includes a ROM and a RAM, and various programs read and executed by the CPU 82 are stored in the ROM. The RAM functions as a work memory for the CPU 82 and stores information that can be rewritten by the CPU 82.

  In particular, as shown in FIG. 1, the air conditioning system 10 of the present embodiment includes a plurality of usage units 30 a to 30 c. Therefore, the air conditioning system controller 80 controls the supply of water at a flow rate suitable for the use units 30a to 30c (that is, the end use units 30a to 30c) located farthest from the chiller unit group 20 side. Terminal differential pressure control is performed.

  For example, it is assumed that the individual usage units 30a to 30c are installed at different levels in a building, while the chiller unit group 20 is installed at the lowest level. It is assumed that the use unit (for example, use unit 30a) installed in the uppermost layer is a unit installed farthest from the chiller unit group 20. In this case, in the use unit 30a located at the farthest position, even if the opening of the use side valve 32a is fully opened, the pressure difference between the inlet side and the outlet side of the unit 30a (that is, water supply pressure) is insufficient. If it does, the appropriate quantity of water will not be supplied to the utilization unit 30a. Therefore, in this embodiment, terminal differential pressure control is performed as control for reliably sending water to each of the usage units 30a to 30c by keeping the water supply pressure appropriately. Further, in this terminal differential pressure control, control is also performed so that the power consumption of the secondary pumps 46 and 47 when the flow rate of water is small is also suppressed.

  Furthermore, in this embodiment, a method is adopted in which the water supply pressure required in the terminal differential pressure control is obtained by estimation without measuring with a pressure gauge or the like. For estimation of the water supply pressure, the water supply pressure model 81a described below is used, but if this water supply pressure model 81a is not a model that matches the actual air conditioning system 10, each of the usage units 30a to 30b has an appropriate flow rate of water. May not be supplied.

  Therefore, the air conditioning system controller 80 of the present embodiment performs the terminal differential pressure control using the water supply pressure model 81a that matches the actual air conditioning system 10. Below, the water supply pressure model 81a required when such operation | movement is performed and the various control operation | movement which CPU82 performs are explained in full detail.

(4-1) Water Supply Pressure Model The water supply pressure model 81a is stored in the memory 81. The water supply pressure model 81a is a model of the water supply pressure H expressed by a function having the total flow rate Q of the water flowing out from each of the usage units 30a to 30c as a variable. For example, the water supply pressure model 81a is represented by the following equation.

  In the above equation (1), “a”, “b”, and “c” in the first, second, and third terms on the right side are parameters. “N” is an integer of 1 or more. That is, the function representing the water supply pressure model 81a has, as a variable, the total flow rate Q of the water that has flowed out of each of the utilization units 30a to 30c, that is, the total flow rate Q of the water circulating in the heat medium circuit 40, a to c. The value of the flow meter 48 according to FIG. 1 is used for the total flow rate Q of the above equation (1).

  FIG. 8 is a graph showing the water supply pressure model 81a as an example, where the horizontal axis represents the total water flow rate Q and the vertical axis represents the water supply pressure H (that is, the pressure head). FIG. 8 shows the case of “n = 2”. In the case of “n = 2”, the water supply pressure H is expressed by a quadratic expression regarding the total water flow rate Q. Further, the water supply pressure H is shifted according to the valve opening degree of the use side valves 32a to 32c in the use units 30a to 30c, as shown in the graphs g1 and g2 of FIG. When the valve openings of the use side valves 32a to 32c are large, the graph of the water supply pressure H is shifted in the direction of the graph g1. Conversely, when the valve openings of the use side valves 32a to 32c are small, the graph of the water supply pressure H shifts in the direction of the graph g2.

  As shown in FIG. 8, in order to draw the graphs g1 and g2 of the water supply pressure H, it is assumed that the values of the parameters a, b, and c of the water supply pressure model 81a have been determined. That is, the shape of the curve drawn by the water supply pressure H with the change in the total water flow rate Q also depends on the parameters a, b, and c. The parameters a, b, and c are preferably determined in advance according to various conditions of the actual air conditioning system 10, but in the present embodiment, they are correction targets in order to match the actual air conditioning system 10.

  In this embodiment, as shown in FIG. 9, the memory 81 stores a plurality of water supply pressure models 81a in which at least one of the parameters a, b, and c is different from each other (the water supply pressure models 81aa, 81ab, 81ac, 81ad). Since a plurality of water supply pressure models 81a are stored in the memory 81, the correction of the parameters a, b, and c can be easily performed by selecting the water supply pressure model 81a having suitable parameters. In FIG. 9, the record number is associated with the function representing the water supply pressure model 81a. As an example, all three parameters a, b, and c of the water supply pressure models 81aa to 81ad are different from each other. Represents the case. In FIG. 9, different parameters are represented as “a1”, “b1”, “c2”, and the like. The parameters “a”, “b”, and “c” of the plurality of water supply pressure models 81aa to 81ad are, for example, various devices included in the air conditioning system 10 (specifically, the secondary pumps 46 and 47, the chiller units 20a to 20a, It is determined in advance appropriately according to the specifications of the various devices constituting the computer 20c and the various devices constituting the use units 30a to 30c, variations thereof, and the like.

(4-2) Terminal differential pressure control using water supply pressure model The CPU 82 mainly controls the secondary side pumps 46 and 47 and the usage side valves 32a to 32c in the usage units 30a to 30c.

  Specifically, the CPU 82 determines the target value of the water supply pressure of the secondary pumps 46 and 47 as the target pressure, and makes the above described so that the actual water supply pressure of the secondary pumps 46 and 47 becomes the target pressure. The inverter frequency of the secondary pumps 46 and 47 is increased or decreased using the water supply pressure model 81a. That is, the CPU 82 performs PID control on the rotational speed of the secondary pumps 46 and 47 based on the target pressure and water supply pressure model 81a, and varies the capacity of the secondary pumps 46 and 47. And CPU82 performs PID control with respect to the temperature in the air-conditioning object space, and increases or decreases the valve opening degree of each use side valve 32a to 32c, thereby causing resistance components (hereinafter referred to as pipe resistance) of the pipes L1 and L2. And the flow rate of water circulating in the pipes L1 and L2, that is, in the heat medium circuit 40, is adjusted.

  FIG. 10 is a graph showing the characteristics of the secondary pumps 46 and 47. In FIG. 10, as in FIG. 8, the horizontal axis represents the total water flow rate Q and the vertical axis represents the water supply pressure H, and the relationship between the total water flow rate Q and the water supply pressure H when the inverter frequency is constant. Is graphed. When the inverter frequency of the secondary pumps 46 and 47 is constant, the water supply pressure H is small when the total water flow rate Q is large, and conversely the water supply pressure H is large when the total water flow rate Q is small. In addition, the total water flow rate Q and the water supply pressure H draw a curve as shown in FIG. 10 (graphs j1, j2). As the frequency of the inverter increases, the curve drawn by the total water flow rate Q and the water supply pressure H shifts so that the total flow rate Q and the water supply pressure H increase as a whole (graph j2). The smaller the frequency, the more the curve shifts so that the total flow rate Q and the water supply pressure H become smaller overall (graph j1).

  In addition, the characteristic of each utilization side valve 32a-32c is as above-mentioned FIG. 8 already demonstrated.

  FIG. 11 is a graph obtained by superimposing the graph of FIG. 10 and the graph of FIG. As shown in FIG. 11, for example, when a graph g2 representing the characteristics of the use side valves 32a to 32c and a graph j2 representing the characteristics of the secondary pumps 46 and 47 are superimposed, an intersection A of each graph appears. Therefore, the CPU 82 determines the intersection point A for each of the secondary pumps 46 and 47, and determines the flow rate q of water at the intersection point A as the flow rate of each of the secondary pumps 46 and 47.

  However, when it is desired to suppress the power consumption of each secondary pump 46, 47, it is preferable that the inverter frequency of each secondary pump 46, 47 is small. When trying to reduce the inverter frequency of each of the secondary pumps 46 and 47, it is inevitably desired to decrease the water supply pressure H and increase the valve openings of the use side valves 32a to 32c. That is, in FIG. 11, even when the same water flow rate q is secured, the inverters of the secondary pumps 46 and 47 are more than the intersection A if the power consumption of the secondary pumps 46 and 47 is further suppressed. It is preferable that the control based on the intersection B between the graph j1 representing the characteristic of the frequency “small” and the graph g1 representing the characteristic of the valve opening “large” of the use side valves 32a to 32c is performed. Therefore, as shown in FIG. 11, the CPU 82 obtains the intersection B when the inverter frequency of the secondary pumps 46 and 47 becomes small while keeping the flow rate q of the intersection A, and the valves of the use side valves 32a to 32c. While changing the opening to the valve opening at the intersection B, the inverter frequency of the secondary pumps 46 and 47 is changed to the inverter frequency at the intersection B. Thereby, the power consumption q of each secondary side pump 46 and 47 can be suppressed more, ensuring the same flow rate q of water as the intersection A.

  Next, the operation for changing the water supply pressure H will be described with reference to FIGS.

  When the target pressure value is decreased from “H1” by “ΔH” (that is, target pressure “H1−ΔH”), the CPU 82 first sets the inverter frequency of each of the secondary pumps 46 and 47 to the target pressure “ Frequency control, that is, rotation speed control is performed so that the value corresponds to H1-ΔH ″. Specifically, as shown in FIG. 12A, the CPU 82 obtains an intersection C when the water supply pressure H becomes the target pressure H1, assuming that the valve openings of the use side valves 32a to 32c are constant. When the target pressure changes from “H1” to “H1−ΔH” from this state, first, the water supply pressure H decreases while the valve openings of the use side valves 32a to 32c remain constant. 47, the intersection D having a small inverter frequency is obtained. At this time, since the valve openings of the use side valves 32a to 32c are constant, that is, the pipe resistance itself is constant, the flow rate of the water flowing in the heat medium circuit 40 (that is, the water flowing through the use units 30a to 30c). The total flow rate Q) decreases from “q1” to “q2”. Then, the flow rate of low-temperature water flowing through the use side heat exchangers 33a to 33c decreases, and as a result, the temperature in the air-conditioning target space increases.

Therefore, the CPU 82 that performs PID control on the temperature in the air-conditioning target space increases the flow rate of water by increasing the valve openings of the use side valves 32a to 32c, as shown in FIG. Take control. That is, since the use side valves 32a to 32c are increased in valve opening, the resistance pipe itself is reduced, and as a result, the water supply pressure H (that is, the pressure head) itself is reduced. The CPU 82 controls the inverter frequency of each of the secondary pumps 46 and 47 so that the water supply pressure H becomes the target pressure “H1 − ΔH”. By this control operation, as shown at the intersection E in FIG. 12B, when the water supply pressure H reaches the target pressure “H1 − ΔH”, the flow rate of water flowing in the heat medium circuit 40 (that is, water The total flow rate Q) returns to the flow rate q1 before changing the water supply pressure H. As described above, in this control operation, the water supply pressure model 81a represented by the graphs of FIG. 8 and FIGS. 12A and 12B described above is used.

  In addition, although the case where the target pressure was decreased was exemplarily described here, the operation of changing the water supply pressure H includes the case where the target pressure is increased. The detailed operation when the target pressure is increased is the reverse of the above case, but is the same in that the flow returns to the flow rate q1 before the water supply pressure H is changed as a result. When the target pressure is decreased and the target pressure is too low, in FIG. 12B, some valve openings of the use side valves 32a to 32c have reached nearly fully open. Therefore, the curve of the valve resistance (that is, the curve corresponding to the magnitude of the valve opening) is not sufficiently lowered, and the flow rate Q of the water flowing in the heat medium circuit 40 is higher than the flow rate q1 before the water supply pressure H is changed. Small flow rate. Accordingly, the air-conditioning target space is in a state where the temperature remains high, which is not suitable as the target pressure.

  In the terminal differential pressure control described above, as shown in FIGS. 13 and 14, the CPU 82 performs the above-described operation of changing the water supply pressure H, that is, the target pressure change control for a predetermined time t2 (hereinafter referred to as a second predetermined time). ) Perform every time. The second predetermined time t2 is not a few seconds but may be “5 minutes”, for example. When the operation of changing the water supply pressure H is continuously performed in units of several seconds, the target pressure is changed before the total water flow rate Q returns before the change of the target pressure, and instead the increase of the water supply pressure H and the total water flow rate Q This is because a so-called hunting phenomenon that promotes an increase in the risk of occurrence may occur. Therefore, the second predetermined time t2 is determined in consideration of the time from when the operation of changing the water supply pressure H is performed until the value of the total water flow rate Q returns to the value before the change of the target pressure. It is preferable. The second predetermined time t2 can be appropriately determined by simulation, experiment, desktop calculation, or the like according to the specifications of various devices constituting the heat medium circuit 40, for example.

(4-3) Correcting Operation of Water Supply Pressure Model If the water supply pressure model 81a is suitable for the actual heat medium circuit 40, as described above, after the second predetermined time t2 has elapsed since the target pressure was changed. The total water flow rate Q should always be the flow rate q1 (see FIG. 13A). However, when the water supply pressure model 81a is incompatible with the actual heat medium circuit 40, as shown in FIG. 13B, after the second predetermined time t2 has elapsed since the target pressure was changed, The total flow rate Q is not the flow rate q1. Therefore, the total water flow rate Q is not properly controlled.

  Therefore, the CPU 82 according to the present embodiment corrects the water supply pressure model 81a so as to be adapted to the heat medium circuit 40. Specifically, the CPU 82 performs a parameter correction operation for correcting at least one of the parameters a to c included in the water supply pressure model 81a based on the value “qb” of the total water flow rate Q after the change of the target pressure. Do.

  Hereinafter, the parameter correction operation according to this embodiment will be described in detail with reference to FIG. The CPU 82 sets the value of the total water flow rate Q before the change of the target pressure to “qa” and the value of the total water flow rate Q after the change of the target pressure as “qb”. The absolute value of the ratio “(qb−qa) / qa” between the Q value “qa” and the change amount “qb−qa” of the total water flow rate Q before and after the change of the target pressure is obtained. Then, the CPU 82 compares this ratio “(qb−qa) / qa” with a predetermined value. When the absolute value of the ratio “(qb−qa) / qa” is lower than the predetermined value, the CPU 82 determines that the parameters ac included in the water supply pressure model 81a are suitable for the actual heat medium circuit 40. Judgment is made and the parameters a to c are not corrected. However, when the absolute value of the ratio “(qb−qa) / qa” is higher than the predetermined value, the CPU 82 indicates that the parameters a to c included in the water supply pressure model 81a are incompatible with the actual heat medium circuit 40. It is determined that there is, and the parameters a to c are corrected.

  That is, if the parameters a to c included in the water supply pressure model 81a are adapted, ideally, the value “qb” of the total water flow Q after the change of the target pressure is the water before the change of the target pressure. Should be approximately equal to the value “qa” of the total flow rate Q. Therefore, ideally, the absolute value of the ratio “(qb−qa) / qa” is infinitely close to “0”. However, if the parameters ac included in the water supply pressure model 81a are incompatible, the value “qb” of the total water flow Q after the change of the target pressure is the value of the total water flow Q before the change of the target pressure. It is not equal to “qa”. In this case, the absolute value of the ratio “(qb−qa) / qa” is not “0”. In particular, the larger the difference between the value “qb” of the total water flow Q after the change of the target pressure and the value “qa” of the total water flow Q before the change of the target pressure, the larger the ratio “(qb−qa)”. The absolute value of / qa "increases. Therefore, the CPU 82 according to the present embodiment obtains the absolute value of the ratio “(qb−qa) / qa”, and sets the parameters a to c included in the water supply pressure model 81a according to the comparison result between the absolute value and the predetermined value. Determine whether correction is necessary.

  In this embodiment, the value “qb” of the total water flow Q after the change of the target pressure is the value of the total water flow Q when the first predetermined time t1 has elapsed since the target pressure was changed. Is used. This is because the value of the total water flow rate Q temporarily changes due to the target pressure changing operation, but eventually converges to one value and becomes almost stable. By using the total flow rate Q of the water when it is stable for the calculation of the ratio, it is possible to determine whether or not the parameters a to c included in the water supply pressure model 81a are corrected more accurately.

  Here, the first predetermined time t1 is shorter than the second predetermined time t2, and can be determined to be “2 minutes”, for example. Similarly to the second predetermined time t2, the first predetermined time t1 also takes into account the time from when the water supply pressure H is changed until the value of the total water flow Q returns to the value before the change of the target pressure. It is preferable that it is determined. The first predetermined time t1 can be appropriately determined by simulation, experiment, desktop calculation, or the like according to, for example, specifications of various devices constituting the heat medium circuit 40.

  Next, correction of the actual water supply pressure model 81a will be described. The memory 81 of the present embodiment stores a plurality of water supply pressure models 81aa to 81ad as already described with reference to FIG. Therefore, when correcting the water supply pressure model 81a, the CPU 82 selects one of the plurality of water supply pressure models 81aa to 81ad according to the ratio “(qb−qa) / qa”. And CPU82 overwrites the selected water supply pressure model 81aa-81ad with respect to the water supply pressure model 81a currently used by the terminal differential pressure | voltage control. The selected water supply pressure models 81aa to 81ad are used when the target pressure is changed next time.

  In addition, although it is about which water supply pressure model 81aa-81ad is selected according to the said ratio "(qb-qa) / qa", the following methods are mentioned, for example. The CPU 82 obtains a difference between the ratio “(qb−qa) / qa” and a predetermined value. Water supply pressure models 81aa to 81ad to be selected are determined according to the degree of the difference. For example, the currently used water pressure model is a record No. in FIG. It is assumed that the water supply pressure model 81aa corresponds to “001”. If the difference between the ratio “(qb−qa) / qa” and the predetermined value is within the range of “5% to 10%”, the CPU 82 records the record No. in FIG. The water pressure model 81ab in the record next to “001” is selected. If the difference is within the range of “11% to 20%”, the CPU 82 records nos. The water supply pressure model 81ac in the record two lower than "001" is selected. If the difference is within the range of “21% to 30%”, the CPU 82 records nos. The water supply pressure model 81ad in the record three lower than "001" is selected.

  By performing the correction operation of the water supply pressure model 81a, the air conditioning system 10 according to the present embodiment is always appropriate even if various conditions in various devices of the heat medium circuit 40 change during operation. Terminal differential pressure control can be performed. Therefore, the air conditioning system 10 not only always monitors whether the water supply pressure model 81a is an appropriate model, but also uses the appropriate water supply pressure model 81a to control the opening degree of the use side valves 32a to 32c and the secondary side. The inverter frequency control of the pumps 46 and 47 can be performed, and the flow rate of water circulating in the heat medium circuit 40 can be maintained at an appropriate amount.

  In FIG. 14, “qa1, qb1, qb2, qb2, qa3, qb3” is used to distinguish the value “qa, qb” of the total water flow measured by the flowmeter 48 at every second predetermined time t2. It is described.

(5) Features of air conditioning system (5-1)
In the present embodiment, the water supply pressure model 81 a of the secondary pumps 46 and 47, represented by a function having the total flow rate Q of the water that is the heat medium flowing out from each of the usage units 30 a to 30 c as a variable, is stored in the memory 81. It is remembered. The CPU 82 controls the rotational speed of the secondary pumps 46 and 47 using the water supply pressure model 81a so that the water supply pressure H of the secondary pumps 46 and 47 becomes the target pressure. Then, the CPU 82 changes the target pressure, and corrects the water supply pressure model 81a based on the value “qb” of the total water flow rate Q after the change of the target pressure. Thereby, the rotational speed control of the secondary pumps 46 and 47 is performed using the water supply pressure model 81a suitable for the actual heat medium circuit 40. Therefore, the rotational speed control of the secondary pumps 46 and 47 can be performed more appropriately, and the flow rate of the heat medium in the heat medium circuit 40 can be maintained at an appropriate flow rate.

(5-2)
Ideally, the value “qa” of the total water flow rate Q before the change of the target pressure is substantially equal to the value “qb” of the total water flow rate Q after the change of the target pressure. Therefore, ideally, the ratio “(qa) of the value“ qa ”of the total water flow Q before the change of the target pressure and the change“ qb−qa ”of the value of the total water flow Q before and after the change of the target pressure. qb−qa) / qa ″ is equal to or less than a predetermined value. However, if the water supply pressure model 81a is not adapted to the actual heat medium circuit 40, the appropriate rotation speed control is not performed on the secondary pumps 46 and 47, and therefore the total flow rate of water before the target pressure is changed. The ratio “(qb−qa) / qa” between the value “qa” of Q and the amount of change “qb−qa” of the total water flow rate Q before and after the change of the target pressure becomes higher than a predetermined value. .

  However, in the air conditioning system 10 according to the present embodiment, when the ratio “(qb−qa) / qa” is higher than a predetermined value, the water supply pressure model 81a is corrected. Therefore, the air conditioning system 10 can appropriately determine whether or not the water supply pressure model 81a is corrected, and can perform the correction of the model 81a when necessary.

(5-3)
In addition to the total water flow rate Q, the function representing the water supply pressure model 81a includes a plurality of parameters ac. These parameters a to c affect the rotational speed control of the secondary pumps 46 and 47. However, since the air conditioning system 10 according to the present embodiment corrects the parameters a to c, the rotational speed control of the secondary pumps 46 and 47 can be performed more accurately.

(5-4)
The memory 81 of the air conditioning system 10 according to the present embodiment stores a plurality of water supply pressure models 81aa to 81ad in which at least one of the parameters a to c is different from each other. The CPU 82 selects one of the plurality of water supply pressure models 81aa to 81ad based on the value “qb” of the total water flow rate Q after the change of the target pressure, and selects the selected water supply pressure models 81aa to 81ad on the secondary side. Used for controlling the rotational speed of the pumps 46 and 47. That is, in the present embodiment, the correction of the water supply pressure model 81a is performed by selecting one of the plurality of water supply pressure models 81aa to 81ad. Thereby, the correction of the water supply pressure model 81a is easily performed.

(5-5)
The value of the total water flow Q is changed by changing the target pressure, but eventually becomes a stable value. Therefore, when the value of the total water flow rate Q immediately after the target pressure is changed is used to correct the water supply pressure model 81a, the model 81a is corrected using the value of the unstable total water flow rate Q. It becomes. However, in the air conditioning system 10 according to the present embodiment, the value of the total water flow rate Q when the first predetermined time t1 has elapsed since the target pressure was changed is used for the correction of the water supply pressure model 81a. Therefore, the value of the stable total flow rate Q of water is used for correction of the water supply pressure model 81a. Accordingly, since the more appropriate correction of the water supply pressure model 81a is performed, the rotational speed control of the secondary pumps 46 and 47 and the like can be performed more accurately.

(5-6)
As described above, the value of the total water flow rate Q changes by changing the target pressure, but eventually becomes a stable value. Therefore, if the target pressure is further changed while the value of the total water flow rate Q is not yet stable, the value of the total water flow rate Q may be hunted. However, in the air conditioning system 10 according to the present embodiment, the target pressure changing operation is performed at a sufficient time interval (that is, the second predetermined time t2), so that the value of the total water flow rate Q is hunted. Can be prevented. Therefore, more accurate control of the rotational speed of the secondary pumps 46 and 47 is performed.

(6) Modification (6-1) Modification A
In the above embodiment, the ratio “(qb) between the value“ qa ”of the total water flow Q before the change of the target pressure and the amount of change“ qb−qa ”of the total water flow Q before and after the change of the target pressure. The case where -qa) / qa "is obtained and the water supply pressure model 81a is corrected according to the ratio" (qb-qa) / qa "has been described.

  However, the correction of the water supply pressure model 81a may be performed based on the value “qb” of the total water flow rate Q after the change of the target pressure. Therefore, the correction of the water supply pressure model 81a may be performed using only the value “qb” of the total water flow rate Q after the change of the target pressure. For example, if the value “qb” of the total water flow Q after the change of the target pressure is more than a predetermined value from the value “qa” of the total water flow Q before the change of the target pressure, the CPU 82 81a may be corrected. In this case, the CPU 82 does not correct the water supply pressure model 81a unless the value “qb” is more than a predetermined value from the value “qa” of the total water flow rate Q before the change of the target pressure.

(6-2) Modification B
In the above embodiment, the case where all the parameters a to c included in the water supply pressure model 81a are corrected has been described. However, the number of parameters to be corrected may be one or two.

  Moreover, in the said embodiment, the case where parameters ac other than the total water flow rate Q were correct | amended was demonstrated. However, the correction target may not be the numerical values themselves of the parameters a to c, but may be a function expression including the parameters.

(6-3) Modification C
In the above-described embodiment, the case where one water supply pressure model is selected from the plurality of water supply pressure models 81aa to 81ad illustrated in FIG. 9 to correct the water supply pressure model 81a has been described. However, the air conditioning system 10 may not store the plurality of water supply pressure models 81aa to 81ad. In this case, the correction of the water supply pressure model 81a may be performed by calculating parameters using various conditions, correction functions, and the like, and rewriting the calculation results with the parameters in the water supply pressure model 81a.

(6-4) Modification D
In the above embodiment, the case where the value of the total water flow rate Q when the first predetermined time t1 has elapsed since the target pressure was changed is used for the correction of the water supply pressure model 81a has been described. However, even if the target pressure is changed, if the value of the total water flow Q is instantaneously stabilized, the target pressure is changed instead of the total water flow Q when the first predetermined time t1 has elapsed. The value of the total water flow rate Q immediately after the correction may be used to correct the water supply pressure model 81a.

(6-5) Modification E
In the above-described embodiment, the case where the target pressure is changed every second predetermined time t2 has been described. However, since the target pressure may be changed a plurality of times at time intervals, the target pressure need not be changed at the same time intervals.

(6-6) Modification F
In the above embodiment, the case where the total flow rate Q of the water circulating in the heat medium circuit 40 is obtained by measurement with the flow meter 48 has been described. However, the total flow rate Q of the water circulating in the heat medium circuit 40 may not be actually measured but may be obtained by estimation. As a method of estimating the total flow rate Q of the water circulating in the heat medium circuit 40, for example, a method determined by the inverter frequency of the secondary pumps 46 and 47, or the like can be given. In this case, the heat medium circuit 40 need not be provided with the flow meter 48.

  Further, the heat medium circulating in the heat medium circuit 40 may be other than water.

(6-7) Modification G
In the embodiment described above, the primary pumps 44a to 44c are metering pumps, and the secondary pumps 46 and 47 are variable displacement pumps. However, both the primary pumps 44a to 44c and the secondary pumps 46 and 47 may be variable displacement pumps.

(6-8) Modification H
In the said embodiment, as shown in FIG. 1, the case where the air-conditioning system 10 was equipped with several chiller units 20a-20c was demonstrated. However, one chiller unit may be used. In this case, one primary pump and one secondary pump are also provided.

DESCRIPTION OF SYMBOLS 10 Air-conditioning system 20 Chiller unit group 20a-20c Chiller unit (heat source machine)
21 refrigerant circuit 22 compressor 23 radiator 24 chiller side expansion valve 25 evaporator 30 use unit group 30a-30c use unit 31a-31c casing 32a-32c use side valve 33a-33c use side heat exchanger (heat exchanger)
34a-34c Electric heater 35a-35c Watering type humidifier 36a-36c Blower fan (fan)
40 Heat medium circuit 41 Return header 42 First feed header 43 Second feed header 44a to 44c Primary pump 45 Flow control valves 46, 47 Secondary pump 48 Flow meter 60 Heat radiation circuit 61 Water pump 70 Cooling tower 80 Air conditioning system controller 81 Memory (storage unit)
82 CPU (control unit)
a, b, c Parameter H Water supply pressure t1 First predetermined time t2 Second predetermined time Q Total flow rate of water (heat medium) H Water supply pressure

JP 2003-106731 A

Claims (6)

A heat source device (20a to 20c) for heating or cooling the heat medium;
Heat exchangers (33a to 33c) that heat or cool the air by performing heat exchange between the heat medium and air, and fans (36a to 36a) that supply the heated or cooled air to the air-conditioning target space 36c), a plurality of usage units (30a-30c) each having
A primary pump connected to a first pipe (L1) that connects an outlet side of each of the utilization units and an inlet side of the heat source unit, and sends the heat medium flowing out from each of the heat exchangers to the heat source unit ( 44a-44c),
It is connected to the second pipe (L2) that connects the outlet side of the heat source unit and the inlet side of each of the utilization units, and is an inverter-driven type that sends the heat medium flowing out from the heat source unit to each heat exchanger A secondary pump (46, 47);
A storage unit (81) for storing a water supply pressure model of the secondary pump represented by a function having a variable of a total flow rate of the heat medium flowing out from each of the utilization units;
A control unit (82) for controlling the rotational speed of the secondary pump using the water supply pressure model so that the water supply pressure of the secondary pump becomes a target pressure;
With
The control unit (82) changes the target pressure and corrects the water supply pressure model based on a value of a total flow rate of the heat medium after the change of the target pressure.
Air conditioning system (10). The control unit (82)
Obtaining a ratio between a value of the total flow rate of the heat medium before the change of the target pressure and a change amount of the value of the total flow rate of the heat medium before and after the change of the target pressure;
When the ratio is higher than a predetermined value, the water pressure model is corrected.
The air conditioning system (10) according to claim 1. The function representing the water supply pressure model includes a plurality of parameters in addition to the total flow rate of the heat medium,
The controller (82) corrects at least one of the parameters included in the water supply pressure model based on a value of the total flow rate of the heat medium after the change of the target pressure.
The air conditioning system (10) according to claim 1 or 2. The storage unit (81) stores a plurality of the water supply pressure models in which at least one of the parameters is different from each other,
The correction of the water supply pressure model by the control unit (82) is performed by selecting one of the plurality of water supply pressure models based on the value of the total flow rate of the heat medium after the change of the target pressure.
The air conditioning system (10) according to claim 3. The controller (82) uses the value of the total flow rate of the heat medium when the first predetermined time has elapsed since the change of the target pressure, for correction of the water supply pressure model.
The air conditioning system (10) according to any one of claims 1 to 4. The control unit (82) changes the target pressure every second predetermined time interval.
The air conditioning system (10) according to any one of claims 1 to 5.

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