Abnormality diagnostic device, air conditioning system, and abnormality diagnostic method

Abstract

To provide an abnormality diagnostic device which can diagnose an abnormality of a conveyance path of air in a VAV system.SOLUTION: An abnormality diagnostic device 8 diagnoses an abnormality of a conveyance path of air in an air conditioning system including a plurality of VAV units. The abnormality diagnostic device includes: an opening fixing instruction section 83 which instructs that an opening of the VAV unit of a diagnostic object of the plurality of VAV units is fixed to a first opening; a blow instruction section 84 which instructs that the number of rotation of a blowing fan of an air conditioner is made constant; and a diagnosis execution section 86 which instructs that the opening of the VAV unit of the diagnostic object is changed to a second opening after the number of rotation of the blowing fan is made constant and the opening of the VAV unit of the diagnostic object is fixed to the first opening and diagnoses the abnormality of the conveyance path of air from the air conditioner to the VAV unit of the diagnostic object on the basis of change amount of air quantity or pressure in the conveyance path before and after the change to the second opening on the basis of the instruction.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to an abnormality diagnosis device, an air conditioning system, and an abnormality diagnosis method. [Background technology]

[0002] Conventionally, a central air conditioning system has been proposed that uses one air conditioner (air conditioning device) to condition multiple rooms. One of these central air conditioning systems is a system (hereinafter also referred to as a "VAV system") that adjusts the volume of conditioned air (hereinafter also referred to as "air") sent from an air conditioner to each room via a duct while adjusting the volume with a variable air volume device (VAV unit). In a VAV system, for example, if there is incorrect wiring of the VAV unit during construction, or if there is a problem with the installation of the duct connecting the air conditioner and the VAV unit, such as twisting or coming loose, it may happen that the air sent from the air conditioner cannot reach each room. Therefore, in a VAV system, there is a demand for a simple diagnosis of an abnormality in the air transport path caused by the above-mentioned problems.

[0003] In relation to abnormality diagnosis in air conditioning equipment, for example, Patent Document 1 discloses a technology (hereinafter also referred to as "prior art") for detecting incorrect wiring of indoor units in so-called multi-type air conditioners that can operate air conditioning by connecting multiple indoor units to one outdoor unit. In this prior art, during a test run after installation work, a mis-piping and mis-wiring detection means 14a or 24a reads a certain temperature change in the detected temperature of the first indoor pipe temperature detection unit 11 or the second indoor pipe temperature detection unit 21 in the indoor unit 1 or 2 that is stopped and has not been instructed to operate air conditioning, and determines that there is incorrect piping or wiring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-221348 A Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, in a VAV system, it is possible to diagnose an abnormality in the air transport path by applying the above-mentioned conventional technology to, for example, detecting incorrect wiring of a VAV unit. However, in the above-mentioned conventional technology, a temperature detection unit individually reads the temperature changes of the first indoor heat exchanger to which the first indoor piping is connected, or the second indoor heat exchanger to which the second indoor piping is connected, to determine incorrect wiring, whereas in a VAV system, it is difficult to send air from an air conditioner to only one VAV unit. Also, in a VAV system, even a closed VAV unit does not completely block air, but allows a small amount of air to pass through in order to ensure ventilation air volume. Therefore, in a VAV system, heat from the air is transmitted to all VAV units. Therefore, in a VAV system, it is difficult to diagnose an abnormality in the air transport path by applying the above-mentioned conventional technology to detecting incorrect wiring of a VAV unit.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an abnormality diagnosis device capable of diagnosing abnormalities related to the air transport path in a VAV system. [Means for solving the problem]

[0007] The abnormality diagnosis device disclosed herein is an abnormality diagnosis device that diagnoses abnormalities related to the transport path of air blown out from an air conditioner in an air conditioning system that is provided for each of a plurality of air-conditioned spaces and has a VAV unit that adjusts the volume of air blown out into the corresponding air-conditioned space in response to the air blown out by the air conditioner, and is characterized in that it is equipped with an opening fixation instruction unit that instructs the opening degree of a VAV unit to be diagnosed among the plurality of VAV units to be fixed to a first opening degree, an air blow instruction unit that instructs the rotation speed of the air conditioner's blower fan to be constant, and a diagnosis execution unit that instructs the opening degree of the VAV unit to be diagnosed to be changed to a second opening degree after the rotation speed of the blower fan is kept constant based on an instruction from the air blow instruction unit and the opening degree of the VAV unit to be diagnosed is fixed to the first opening degree based on an instruction from the opening fixation instruction unit, and diagnoses abnormalities related to the air transport path from the air conditioner to the VAV unit to be diagnosed based on the change in air volume or pressure in the transport path before and after the change to the second opening degree based on the instruction. Effect of the Invention

[0008] According to the present disclosure, with the above-mentioned configuration, it becomes possible to diagnose abnormalities related to the air transport path in a VAV system. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing a configuration example of an air conditioning system equipped with an abnormality diagnostic device according to a first embodiment. [Diagram 2] 1 is a diagram showing an overview of control performed by a VAV unit control device in the first embodiment. [Diagram 3] 1 is a graph illustrating how to determine the opening degree-air resistance characteristics of a VAV unit. [Figure 4] 4 is a flowchart showing the processing of the VAV unit control device in the first embodiment. [Diagram 5] 2 is a diagram showing the processing of the VAV unit control device in the first embodiment in the form of an equivalent circuit. FIG. [Figure 6] 1 is a diagram illustrating an example of the configuration of an abnormality diagnostic device according to a first embodiment. [Figure 7] 1 is a configuration diagram of an air conditioning system for explaining an example of the operation of the abnormality diagnostic device according to the first embodiment. FIG. [Figure 8] FIG. 8 is a diagram in which the configuration diagram shown in FIG. 7 is simulated as an electric circuit. [Figure 9] FIG. 2 is a diagram for explaining an installation example (installation example 1) of the pressure sensor in the first embodiment. [Figure 10] 4 is a diagram for explaining an installation example (installation example 2) of the pressure sensor in the first embodiment. FIG. [Figure 11] 2A to 2C are diagrams for explaining installation examples (installation examples 1 and 2) of the pressure sensor in the first embodiment. [Figure 12] 11 is a flowchart showing an example of the operation of the abnormality diagnostic device when the pressure sensor is installed as in Installation Example 1. [Figure 13] 4 is a graph showing the relationship between the static pressure-air volume characteristics of the blower fan and the combined resistance of the VAV unit in the first embodiment. [Figure 14] 13 is a flowchart showing an example of the operation of the abnormality diagnostic device when the pressure sensor is installed as in Installation Example 2. [Figure 15] FIG. 2 is a diagram for explaining an installation example (installation example 1) of the air flow sensor in the first embodiment. [Figure 16] 6 is a diagram for explaining an installation example (installation example 2) of the air flow sensor in the first embodiment. FIG. [Figure 17] 2A to 2C are diagrams for explaining installation examples (installation examples 1 and 2) of the air flow sensor in the first embodiment. [Figure 18] 11 is a flowchart showing an example of the operation of the abnormality diagnostic device when the air flow sensor is installed as in Installation Example 1. [Figure 19] 13 is a flowchart showing an example of the operation of the abnormality diagnostic device when the air flow sensor is installed as in Installation Example 2. [Figure 20] FIG. 20A is a graph showing the relationship between the number of VAV units that are "fully open" and the combined resistance, and FIG. 20B is a graph showing the relationship between the number of VAV units that are "fully open" and the air volume and upstream static pressure.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Embodiment 1. FIG. 1 is a diagram showing an air conditioning system 100 including an abnormality diagnosis device 8 according to Embodiment 1. The air conditioning system 100 performs air conditioning for a plurality of rooms. In FIG. 1, cases where rooms A to C are air conditioning target spaces are shown.

[0011] The air conditioning system 100 includes a VAV unit control device 1, an air conditioner 2, a duct 3, VAV units 4A to 4C, an outdoor unit 5, a building-wide air conditioning controller 6, a branch chamber 7, an abnormality diagnosis device 8, and sensors (pressure sensor 9a or air volume sensor 9b), etc.

[0012] Among these, the VAV unit control device 1 that controls the VAV units 4A to 4C has already been the subject of a patent application by the applicant of the present application and has been patented as Patent No. 6877213. And the abnormality diagnosis device 8 according to Embodiment 1 is assumed to be additionally installed in the air conditioning system 100 including this VAV unit control device 1. Therefore, in the following description, first, the air conditioning system 100 including the VAV unit control device 1 will be described, and then the abnormality diagnosis device 8 additionally installed in this air conditioning system 100 will be described.

[0013] <VAV Unit Control Device 1> The VAV unit control device 1 controls the VAV units 4A to 4C. Specifically, the VAV unit control device 1 controls the opening degrees of dampers 41A to 41C included in the VAV units 4A to 4C. Hereinafter, the "opening degrees of the dampers 41A to 41C" will also be appropriately referred to as the "opening degrees of the VAV units 4A to 4C".

[0014] The air conditioner 2 creates and sends out air (conditioned air) such as cold air or hot air. The air conditioner 2 is installed on the ceiling of a building or the like, and includes a heat exchanger 21 and a blower fan 22. The air conditioner 2 circulates a refrigerant between the outdoor unit 5, and the air that has exchanged heat with the refrigerant in the heat exchanger 21 is sent out as cold air or hot air by the blower fan 22.

[0015] The duct 3 is provided between the air conditioner 2 and the rooms A to C, and guides the cool air or hot air sent out by the air conditioner 2 to the rooms A to C.

[0016] The VAV units 4A to 4C are provided for each of the rooms A to C. The VAV units 4A to 4C include dampers 41A to 41C, etc. The VAV units 4A to 4C are provided between the duct 3 and the air outlets of the rooms A to C, and the dampers 41A to 41C adjust the volume of air blown into the corresponding rooms.

[0017] The outdoor unit 5 includes a compressor 51 and a heat exchanger 52, and is provided outside the room. Due to the actions of the compressor 51 and the heat exchanger 52, the refrigerant is heated during heating and cooled during cooling.

[0018] The central air-conditioning controller 6 cooperates with the VAV unit control device 1 to control the operations of the air conditioner 2, the outdoor unit 5, and the VAV units 4A to 4C. The central air-conditioning controller 6 has a blower fan output setting unit 61 and an opening degree setting unit 62.

[0019] The blower fan output setting unit 61 calculates the rotation speed of the blower fan 22 to correspond to the total air volume obtained by adding up the requested air volumes of the rooms calculated by the VAV unit control device 1, that is, the rotation speed at which the total air volume can be supplied. Then, the blower fan output setting unit 61 outputs a control signal to set the blower fan 22 to the calculated rotation speed.

[0020] The opening setting unit 62 acquires the openings of the VAV units 4A to 4C calculated by the VAV unit control device 1, and outputs a control signal to set the acquired openings in the VAV units 4A to 4C.

[0021] The branch chamber 7 is provided between the air conditioner 2 and the rooms A to C, and receives the cold air or hot air sent out by the air conditioner 2. The cold air or hot air introduced into the branch chamber 7 is branched via the duct 3 to the VAV units corresponding to each room.

[0022] When it is desired to blow a certain amount of cool or hot air from VAV unit 4A into room A, if the primary side static pressure of VAV unit 4A is known, the opening degree of damper 41A of VAV unit 4A is uniquely determined. This is similar for VAV units 4B and 4C other than VAV unit 4A. The primary side of a VAV unit refers to the side where the air conditioner 2 is located as viewed from the VAV unit, and corresponds to the upstream side. However, there are several factors that cause fluctuations in this primary side static pressure. Fluctuations in the primary side static pressure become disturbances when controlling VAV units 4A to 4C.

[0023] An example of a disturbance in controlling the VAV units 4A to 4C is a change in the air volume in other rooms. The cool or warm air sent out by the air conditioner 2 is branched in the branch chamber 7 and sent to each room by the duct 3. That is, the air outlets of each of the rooms A to C are connected via the branch chamber 7. For this reason, the air volumes of the rooms A to C interfere with each other, and if there is a change in the air volume blown into one room due to a change in the heat load or a change in the set temperature, it affects the air volumes blown into the other rooms.

[0024] Another example of a disturbance in controlling the VAV units 4A to 4C is a change in the air volume setting of the air conditioner 2. When the rotation speed of the blower fan 22 is changed to increase or decrease the volume of air sent out by the air conditioner 2, changing the air volume setting of the air conditioner 2 changes the static pressure-air volume characteristic of the blower fan 22, which affects the volume of air sent out to all of the rooms A to C.

[0025] In order to reduce the influence of such disturbances, the VAV unit control device 1 has an air volume calculation unit 11, a fan static pressure calculation unit 12, a primary side static pressure calculation unit 13, a resistance calculation unit 14, an opening calculation unit 15, and a correction unit 16. Fig. 2 is a diagram showing an overview of the control by the VAV unit control device 1.

[0026] The airflow calculation unit 11 calculates the required airflow to be blown into each room A to C by a feedback calculation, for example, a PID (Proportional Integral Differential) calculation, in which the target value is the set temperature of the room and the control amount is the indoor temperature of the room. The airflow calculation unit 11 obtains the set temperature of the room, for example, from a remote control (not shown). The remote control is placed, for example, for each room, and the user can operate the remote control to instruct the air conditioning system 100 to the desired set temperature. The airflow calculation unit 11 also obtains the indoor temperature of the room from a temperature sensor (not shown) provided in the room. The temperature sensor is, for example, built into the remote control (not shown) for the user to instruct the set temperature. The airflow calculation unit 11 outputs the calculated required airflow of each room to the fan static pressure calculation unit 12, the primary side static pressure calculation unit 13, the resistance calculation unit 14, and the correction unit 16.

[0027] The fan static pressure calculation unit 12 calculates the total air volume by summing up the required air volumes of each room calculated by the air volume calculation unit 11, and in the first embodiment, summing up the required air volumes of the rooms A to C. The fan static pressure calculation unit 12 then calculates the outlet static pressure of the blower fan 22 using the total air volume and the static pressure-air volume characteristic of the blower fan 22 of the air conditioner 2. Since the static pressure-air volume characteristic of the blower fan 22 for each air volume setting is known as the specifications of the blower fan, once the blowing air volume of the blower fan 22 is determined, the outlet static pressure of the blower fan 22 can be calculated from the static pressure-air volume characteristic of the blower fan 22 corresponding to that air volume. The fan static pressure calculation unit 12 assumes that the total air volume obtained by summing up the required air volumes of the rooms A to C is blown out from the blower fan 22, and estimates the outlet static pressure of the blower fan 22 at that time using the total air volume, that is, the air volume setting of the blower fan 22, and the static pressure-air volume characteristic of the blower fan 22. The static pressure-air volume characteristic of the blower fan 22 for each air volume setting is stored in advance in a storage unit (not shown). The fan static pressure calculation unit 12 outputs the calculated outlet static pressure of the blower fan 22 to the primary side static pressure calculation unit 13.

[0028] In this way, under the assumption that the total air volume obtained by adding up the required air volumes of rooms A to C is blown out from the blower fan 22, the VAV unit control device 1 calculates the outlet static pressure of the blower fan 22 as described above in the fan static pressure calculation section 12, thereby reflecting the influence of external disturbances such as fluctuations in the air volume in other rooms and changes to the air volume setting of the air conditioner 2 in calculations subsequent to the calculation of the outlet static pressure of the blower fan 22.

[0029] The primary static pressure calculation unit 13 calculates the primary static pressure for each of the VAV units 4A to 4C. In the case of the primary static pressure of the VAV unit 4A, the primary static pressure calculation unit 13 calculates the primary static pressure of the VAV unit 4A using the required air volume of the room A calculated by the air volume calculation unit 11, the outlet static pressure of the blower fan 22 calculated by the fan static pressure calculation unit 12, and the air resistance of the duct 3 provided between the blower fan 22 and the VAV unit 4A. The calculation of the primary static pressure of the VAV units 4B and 4C is similar. Note that the amount of air resistance received from the duct 3 from the blower fan 22 to the VAV unit 4A is previously obtained by actual measurement or numerical calculation, etc., and is stored in a storage unit (not shown). The primary static pressure calculation unit 13 outputs the calculated primary static pressure of the VAV units 4A to 4C to the resistance calculation unit 14.

[0030] Resistance calculation unit 14 calculates the required air resistance for each of VAV units 4A to 4C. In the case of the air resistance of VAV unit 4A, resistance calculation unit 14 calculates the air resistance required for VAV unit 4A using the required air volume for room A calculated by air volume calculation unit 11 and the primary side static pressure of VAV unit 4A calculated by primary side static pressure calculation unit 13. The same is true for calculating the air resistance required for VAV units 4B and 4C. Resistance calculation unit 14 outputs the calculated air resistance required for VAV units 4A to 4C to opening calculation unit 15.

[0031] The opening degree calculation unit 15 calculates the opening degree for each of the VAV units 4A to 4C. In the case of the opening degree of the VAV unit 4A, the opening degree calculation unit 15 calculates the opening degree of the VAV unit 4A using the air resistance required for the VAV unit 4A calculated by the resistance calculation unit 14 and the opening degree-air resistance characteristic of the VAV unit 4A. The air volume-differential pressure characteristic at each opening degree of the VAV unit 4A is known. The differential pressure of the VAV unit 4A is the differential pressure between the primary side and the secondary side of the VAV unit 4A. The opening degree-air resistance characteristic of the VAV unit 4A can be obtained by linearly approximating the air volume-differential pressure characteristic of the VAV unit 4A for each opening degree. For example, the air volume-differential pressure characteristic at the opening degree α of the VAV unit 4A is the curve S shown in FIG. 3. The air resistance at the opening degree α is obtained from the slope of the straight line L that is a linear approximation of this curve S. Several air resistances for each opening degree are obtained to determine the opening degree-air resistance characteristic. In this way, the opening degree-air resistance characteristic is determined in advance and stored in a storage unit (not shown). The calculation of the opening degrees of the VAV units 4B and 4C is performed in the same manner.

[0032] The correction unit 16 is configured to perform a correction to lower the total air volume when the total air volume calculated by the air volume calculation unit 11 by adding up the required air volumes of each room exceeds the blowing capacity of the blower fan 22 and the required air volumes of all rooms A to C cannot be achieved simultaneously.

[0033] Correction unit 16, for example, relaxes the set temperature of a room with a low priority and outputs it to air volume calculation unit 11, and air volume calculation unit 11 recalculates the required air volume of the room using the relaxed set temperature output by correction unit 16. The priorities of rooms A to C are set in advance. Relaxing the set temperature means lowering the set temperature during heating and raising the set temperature during cooling. For example, the set temperature is lowered by 2°C during heating and raised by 1°C during cooling.

[0034] The correction unit 16 may relax the set temperatures of multiple rooms, for example, relaxing the set temperatures of not only the room with the lowest priority but also the room with the next lowest priority. The correction unit 16 may also relax the set temperatures of all rooms regardless of priority. In addition, the correction unit 16 may instruct the air volume calculation unit 11 to directly reduce the required air volume for each room calculated by the air volume calculation unit 11 so that the total air volume falls within a value that does not exceed the blowing capacity of the blower fan 22, and to output the reduced value to the fan static pressure calculation unit 12, the primary side static pressure calculation unit 13, and the resistance calculation unit 14.

[0035] The correction unit 16 may also use the actual air volume setting of the blower fan 22 at that time to determine whether to relax the set temperature of a room with a low priority. For example, when the blower fan 22 is operating at the maximum air volume setting at that time, and the VAV unit corresponding to a room other than the low-priority room for which the set temperature is to be relaxed is open to 100% at that time, and the indoor temperature of the room in which the VAV unit is open to 100% is lower than the set temperature by a threshold value or more, the set temperature of the room with a low priority is relaxed. The threshold value is set to, for example, about 1.5°C. The actual air volume setting of the blower fan 22 at that time can be obtained from the central air-conditioning controller 6 that controls the air conditioner 2 and the outdoor unit 5.

[0036] The air volume calculation unit 11, the fan static pressure calculation unit 12, the primary side static pressure calculation unit 13, the resistance calculation unit 14, the opening degree calculation unit 15, and the correction unit 16 are realized, for example, by a processor (not shown) executing a program stored in a memory (not shown). Also, they may be realized by linking multiple processors and multiple memories.

[0037] Next, an example of processing by the VAV unit control device 1 configured as above will be described with reference to the flowchart shown in FIG.

[0038] The VAV unit control device 1 acquires the set temperature designated by the user by operating a remote control (not shown), etc. The VAV unit control device 1 also periodically acquires the room temperature from a temperature sensor (not shown) installed in each room. In a state in which the VAV unit control device 1 acquires the set temperature and the room temperature, the flowchart shown in Fig. 4 is executed periodically, for example, every time the room temperature is acquired.

[0039] The airflow calculation unit 11 calculates the required airflow to be blown into each of the rooms A to C by feedback calculation with the target value being the set temperature of the room and the control amount being the indoor temperature of the room (step ST1). The airflow calculation unit 11 outputs the calculated required airflow to the correction unit 16.

[0040] Next, the correction unit 16 determines whether the total air volume, which is the sum of the required air volumes of the rooms calculated by the air volume calculation unit 11, exceeds the air blowing capacity of the blower fan 22 (step ST2). For example, when the total air volume exceeds the maximum air volume of the blower fan 22, the correction unit 16 determines that the air blowing capacity of the blower fan 22 is exceeded.

[0041] If the correction unit 16 determines that the total air volume exceeds the air blowing capacity of the blower fan 22 (step ST2; YES), the correction unit 16 relaxes the set temperature of the room with the low priority and outputs it to the air volume calculation unit 11 (step ST3).

[0042] Next, the air volume calculation unit 11 recalculates the required air volume for the room whose set temperature has been relaxed by feedback calculation using the relaxed set temperature (step ST4). After the process of step ST4, the process returns to step ST2, and the processes of steps ST3 and ST4 are repeated until the total air volume does not exceed the blowing capacity of the blower fan 22.

[0043] If the correction unit 16 determines that the total air volume does not exceed the blowing capacity of the blower fan 22 (step ST2; NO), the air volume calculation unit 11 outputs the calculated required air volume for each room to the fan static pressure calculation unit 12, the primary side static pressure calculation unit 13, and the resistance calculation unit 14, and the fan static pressure calculation unit 12 calculates the outlet static pressure of the blower fan 22 using the total air volume obtained by adding up the required air volumes for each room calculated by the air volume calculation unit 11 and the static pressure-air volume characteristics of the blower fan 22 of the air conditioner 2 (step ST5). The fan static pressure calculation unit 12 outputs the calculated outlet static pressure of the blower fan 22 to the primary side static pressure calculation unit 13.

[0044] Next, the primary side static pressure calculation unit 13 calculates the primary side static pressure for each of the VAV units 4A to 4C (step ST6). As already described, for example, in the case of the primary side static pressure of the VAV unit 4A, the primary side static pressure calculation unit 13 calculates the primary side static pressure of the VAV unit 4A using the required air volume of the room A calculated by the air volume calculation unit 11, the outlet static pressure of the blower fan 22 calculated by the fan static pressure calculation unit 12, and the air resistance of the duct 3 provided between the blower fan 22 and the VAV unit 4A. The primary side static pressure calculation unit 13 outputs the calculated primary side static pressures of the VAV units 4A to 4C to the resistance calculation unit 14.

[0045] Next, resistance calculation unit 14 calculates the required air resistance for each of VAV units 4A to 4C (step ST7). As already described, for example, in the case of the air resistance of VAV unit 4A, resistance calculation unit 14 calculates the air resistance required for VAV unit 4A using the required air volume for room A calculated by air volume calculation unit 11 and the primary static pressure of VAV unit 4A calculated by primary static pressure calculation unit 13. Resistance calculation unit 14 outputs the calculated air resistance required for VAV units 4A to 4C to opening degree calculation unit 15.

[0046] Next, the opening degree calculation unit 15 calculates the opening degree for each of the VAV units 4A to 4C (step ST8). As already described, for example, in the case of the opening degree of the VAV unit 4A, the opening degree calculation unit 15 calculates the opening degree of the VAV unit 4A using the air resistance required for the VAV unit 4A calculated by the resistance calculation unit 14 and the opening degree-air resistance characteristic of the VAV unit 4A.

[0047] In this manner, the opening degrees of the VAV units 4A-4C are calculated by the VAV unit control device 1. The calculated opening degrees are output to the opening degree setting section 62 of the central building air-conditioning controller 6, and the opening degree setting section 62 outputs control signals indicating these opening degrees to the corresponding VAV units 4A-4C. Upon receiving these control signals, the VAV units 4A-4C rotate the dampers 41A-41C by a drive mechanism (not shown) equipped with a motor or the like so that the opening degrees are the ones calculated by the VAV unit control device 1.

[0048] The required air volume of each room calculated by the air volume calculation unit 11 is output to the central air-conditioning controller 6, and the air conditioner 2 controlled by the central air-conditioning controller 6 sends out cool air or hot air of a total air volume obtained by adding up the required air volumes of each room. Specifically, the central air-conditioning controller 6 is provided with a blower fan output setting unit 61 that calculates the rotation speed of the blower fan 22, which is a rotation speed that can accommodate the total air volume obtained by adding up the required air volumes of each room, that is, a rotation speed that can supply the total air volume. If the specifications of the air conditioner 2 allow the blower fan 22 to be set in stages, for example, in three stages of low, medium, and high, the blower fan output setting unit 61 selects one of the three stages, low, medium, and high, according to the total air volume, thereby substantially calculating the rotation speed that can accommodate the total air volume. In other words, in this case, selecting a stage means calculating the rotation speed. Then, the blower fan output setting unit 61 outputs a control signal to set the calculated rotation speed to the blower fan 22. The VAV unit control device 1 has such an air blower fan output setting section 61 in the central air conditioning controller 6.

[0049] In this way, the VAV unit control device 1 performs control by incorporating feedforward correction that takes into account disturbances such as fluctuations in the air volumes of other rooms and changes in the air volume setting of the air conditioner 2, using the required air volume of each room calculated by the air volume calculation unit 11. This makes it possible to perform control that reduces the influence of disturbances without using an air volume sensor that measures the air volume sent out by the VAV units 4A to 4C or a pressure sensor that measures the air pressure. In contrast, as already mentioned, conventionally, feedback control has been performed in which an air volume sensor or pressure sensor is essential to remove the influence of disturbances such as those described above.

[0050] Fig. 5 uses an equivalent circuit to explain how the above-mentioned VAV unit control device 1 calculates the opening degrees of the VAV units 4A to 4C. In the equivalent circuit of Fig. 5, the blower fan 22, the duct 3, the VAV units 4A to 4C, etc. are replaced with a voltage source and resistors.

[0051] In Figure 5, air resistance Ri is the sum of the air resistance inside the air conditioner 2 after the speed, i.e., the rotational speed, of the blower fan 22 is selected, and air resistance R0. Air resistance R0 is the air resistance from the air conditioner 2 to the outlet of the branch chamber 7. Air volume I0 is the total air volume sent out by the air conditioner 2, and is the sum of air volumes I1, I2, and I3. Air resistances R1 to R3 are the air resistances of the duct 3 from the outlet of the branch chamber 7 to the VAV units 4A to 4C. Air resistance R V1 ~R V3 is the air resistance of VAV units 4A to 4C.

[0052] The pressure loss Vrs from the blower fan 22 to the outlet of the branch chamber 7 is expressed by the formula (1). Vrs=R i ×I0(1) Therefore, the air pressure Vc at the outlet of the branch chamber 7 is expressed by the formula (2). Vc=E i -Vrs (2)

[0053] If you want to blow air into room A with a volume of I1, the air resistance R required for VAV unit 4A is V1 is expressed as equation (3). R V1 = Vc / I1-R1(3) Similarly, the air resistance R required for VAV unit 4B is V2 is expressed as equation (4), and the air resistance R required for the VAV unit 4C is V3 is expressed as equation (5). R V2 = Vc / I2-R2(4) R V3 = Vc / I3-R3(5)

[0054] Air resistance R calculated using equation (3) V1 The opening degree A1 of the VAV unit 4A required to obtain is calculated using the opening degree-air resistance characteristic. If the function for calculating the opening degree from the air resistance of the VAV unit 4A is fra(), the opening degree A1 is expressed as in formula (6). A1 = fra(R V1) (6) Similarly, air resistance R V2 The opening degree A2 of the VAV unit 4B required to obtain the above is expressed as in equation (7), and the air resistance R V3 The opening degree A3 of the VAV unit 4C required to obtain the above is expressed as in equation (8). A2 = fra(R V2 ) (7) A3 = fra(R V3 ) (8)

[0055] In FIG. 5, not only the air resistance due to duct 3 is taken into account, but also the pressure loss from blower fan 22 to the outlet of branch chamber 7, i.e., the air resistance due to branch chamber 7, as in equations (1) and (2). However, in cases where air conditioning system 100 is configured in a way that is less affected by branch chamber 7, the primary side static pressure of VAV units 4A to 4C may be calculated without taking into account the air resistance due to branch chamber 7.

[0056] In the above explanation, some error occurs due to the linear approximation of the relationship between the flow rate and pressure loss of the entire duct system. However, this error is eliminated by feedback calculation in the air volume calculation unit 11, and does not affect the accuracy of the indoor temperature that each room ultimately reaches.

[0057] As described above, according to the first embodiment of the present invention, the VAV unit control device 1 can control the VAV units 4A-4C by using the required air volume for each room calculated by the air volume calculation section 11, taking into consideration disturbances such as fluctuations in the air volumes in other rooms and changes to the air volume setting of the air conditioner 2. This allows control with reduced influence of disturbances to be performed without providing an air volume sensor that measures the air volume sent out by the VAV units 4A-4C or a pressure sensor that measures air pressure. Furthermore, the VAV unit control device 1's ability to reduce the influence of disturbances during control also leads to improved response speed until the indoor temperature reaches the set temperature.

[0058] Furthermore, the VAV unit control device 1 includes a correction unit 16 that relaxes the set temperature of a conditioned space with a low priority, and the air volume calculation unit 11 calculates the required air volume using the set temperature relaxed by the correction unit 16. This enables the VAV unit control device 1 to perform air conditioning so that the set temperature is preferentially achieved in a room with a high priority.

[0059] <Abnormality diagnosis device 8> Next, an explanation will be given of the abnormality diagnostic device 8 according to the embodiment 1. The abnormality diagnostic device 8 diagnoses abnormalities in the air transport path from the air conditioner 2 through the duct 3 and branch chamber 7 to the VAV units 4A to 4C in the air conditioning system 100 equipped with the VAV unit control device 1.

[0060] The abnormality diagnostic device 8 includes an interface unit 81, a diagnostic mode instructing unit 82, an opening degree fixing instructing unit 83, an airflow instructing unit 84, a threshold calculation unit 85, and a diagnostic execution unit 86, as shown in FIG.

[0061] The interface unit 81 is a functional unit that realizes an interface function with a user. The interface unit 81 is configured to include, for example, a display unit such as a display and an input unit such as a keyboard, and receives instructions from the user to start or end a diagnosis, and presents the diagnosis result to the user.

[0062] When the interface unit 81 receives an instruction from the user to start diagnosis, it outputs information indicating the instruction (hereinafter also referred to as "diagnosis start information") to the diagnosis mode instructing unit 82. When the interface unit 81 receives an instruction from the user to end diagnosis, it outputs information indicating the instruction (hereinafter also referred to as "diagnosis end information") to the diagnosis mode instructing unit 82.

[0063] The diagnostic mode instructing unit 82 acquires diagnostic start information or diagnostic end information from the interface unit 81. When the diagnostic mode instructing unit 82 acquires diagnostic start information from the interface unit 81, it instructs the central building air-conditioning controller 6 to stop temperature control of the central building air-conditioning in order to make a diagnosis. When the central building air-conditioning controller 6 receives this instruction, it stops the circulation of refrigerant between the air conditioners 2 and the outdoor units 5, and stops the temperature control of the central building air-conditioning.

[0064] When the diagnostic mode instructing unit 82 acquires the diagnosis end information from the interface unit 81, it instructs the central building air-conditioning controller 6 to resume temperature control of the central building air-conditioning. Upon receiving this instruction, the central building air-conditioning controller 6 resumes the circulation of refrigerant between the air conditioners 2 and the outdoor units 5, and resumes temperature control of the central building air-conditioning.

[0065] When diagnosis start information is output from the interface unit 81 and the temperature control of the central building air conditioning is stopped by the central building air conditioning controller 6, the opening fixation instruction unit 83 instructs the central building air conditioning controller 6 to fix the opening degrees of the VAV units 4A to 4C to the first opening degree. When the central building air conditioning controller 6 receives this instruction, the opening setting unit 62 outputs a control signal to fix the opening degrees of the VAV units 4A to 4C to the first opening degree. The VAV units 4A to 4C include the VAV unit to be diagnosed.

[0066] In the above description, the opening degree fixing instruction unit 83 is a functional unit separate from the opening degree setting unit 62 of the central building air conditioning controller 6. However, the opening degree fixing instruction unit 83 may be configured to be able to execute the function of the opening degree setting unit 62 of the central building air conditioning controller 6. In other words, when diagnosis start information is output from the interface unit 81 and the temperature control of the central building air conditioning is stopped by the central building air conditioning controller 6, the opening degree fixing instruction unit 83 may output a control signal itself to fix the opening degrees of the VAV units 4A to 4C to the first opening degree. In this case, the opening degree fixing instruction unit 83 functions as an opening degree fixing unit that fixes the opening degrees of each of the VAV units 4A to 4C to the first opening degree.

[0067] When the opening degrees of the VAV units 4A to 4C are fixed to the first opening degrees as described above, the air blowing instruction unit 84 instructs the central building air-conditioning controller 6 to maintain a constant rotation speed of the blower fan 22 of the air conditioner 2. When the central building air-conditioning controller 6 receives this instruction, the blower fan output setting unit 61 outputs a control signal to set the rotation speed of the blower fan 22 to a constant speed.

[0068] In the above description, the air blow instruction unit 84 is a functional unit separate from the air blower fan output setting unit 61 of the central air-conditioning controller 6. However, the air blow instruction unit 84 may be configured to be able to execute the function of the air blower fan output setting unit 61 of the central air-conditioning controller 6. In other words, when the opening degrees of the VAV units 4A to 4C are fixed to the first opening degree as described above, the air blow instruction unit 84 may output a control signal itself to set the rotation speed of the air blower fan 22 to a constant value. In this case, the air blow instruction unit 84 functions as an air blow setting unit that keeps the rotation speed of the air blower fan 22 of the air conditioner 2 constant.

[0069] The threshold calculation unit 85 calculates a threshold used for abnormality diagnosis by the diagnosis execution unit 86, which will be described later. An example of the calculation of the threshold by the threshold calculation unit 85 will be described later.

[0070] When the openings of the VAV units 4A to 4C are fixed to the first opening and the rotation speed of the blower fan 22 is set constant as described above, the diagnosis execution unit 86 instructs the central building air-conditioning controller 6 to change the opening of the VAV unit to be diagnosed among the VAV units 4A to 4C to the second opening. When the central building air-conditioning controller 6 receives this instruction, the opening setting unit 62 outputs a control signal to change the opening of the VAV unit to be diagnosed to the second opening. Note that which VAV unit is to be diagnosed is designated, for example, by the user.

[0071] In the above description, the diagnosis execution unit 86 has been described as a functional unit separate from the opening setting unit 62 of the central air-conditioning controller 6. However, the diagnosis execution unit 86 may be configured to be able to execute the functions of the opening setting unit 62 of the central air-conditioning controller 6. In other words, when the openings of the VAV units 4A-4C are fixed to the first opening and the rotation speed of the blower fan 22 is set to a constant as described above, the diagnosis execution unit 86 may itself output a control signal to change the openings of the VAV units 4A-4C to the second opening.

[0072] The diagnosis execution unit 86 then diagnoses an abnormality in the air transport path from the air conditioner 2 to the VAV unit to be diagnosed based on the amount of change in the air volume or pressure in the air transport path before and after changing the opening of the VAV unit to be diagnosed to the second opening. Specifically, the diagnosis execution unit 86 compares the amount of change in the air volume or pressure in the air transport path before and after changing the opening of the VAV unit to be diagnosed to the second opening with the threshold calculated by the threshold calculation unit 85, and diagnoses an abnormality in the air transport path from the air conditioner 2 to the VAV unit to be diagnosed based on the comparison result. The diagnosis execution unit 86 then presents the diagnosis result to the user via the interface unit 81.

[0073] The diagnosis execution unit 86 may perform the above diagnosis on one VAV unit designated by the user as the VAV unit to be diagnosed by changing the opening degree, or may perform the above diagnosis on any one or more VAV units by changing the opening degree of each of them. For example, when performing the above diagnosis on all VAV units, the diagnosis execution unit 86 diagnoses abnormalities in the air transport path from the air conditioner 2 to each VAV unit by repeating the above diagnosis while sequentially changing the VAV unit to be diagnosed.

[0074] In the above description, the interface unit 81 realizes an interface function between the user and the abnormality diagnosis device 8. However, the interface function between the user and the abnormality diagnosis device 8 is not limited to the interface unit 81, and may be realized by, for example, an operation terminal (not shown) attached to the air conditioning system 100. This operation terminal is basically a terminal for the user to give a predetermined operation instruction to the air conditioning system 100 or the central air conditioning controller 6, and is composed of, for example, a remote control attached to a wall of the building in which the air conditioning system 100 is installed, or a dedicated tablet on which a predetermined application is installed. For example, the user may input an instruction to start or end the diagnosis to this operation terminal, and in that case, this operation terminal may output the above-mentioned diagnosis start information or diagnosis end information to the diagnosis mode instruction unit 82. In that case, the diagnosis execution unit 86 may present the diagnosis result to the user via this operation terminal.

[0075] The diagnostic mode instructing unit 82, the opening degree fixing instructing unit 83, the airflow instructing unit 84, the threshold calculation unit 85, and the diagnostic execution unit 86 are realized, for example, by a processor (not shown) executing a program stored in a memory (not shown). Also, they may be realized by linking a plurality of processors and a plurality of memories.

[0076] Next, an operation example of the abnormality diagnosis device 8 according to the embodiment 1 will be described. For convenience of explanation, the following description will be given of an operation example in an air conditioning system 100 configured as shown in the configuration diagram of FIG.

[0077] In the air conditioning system 100 shown in Fig. 7, the air conditioner 2 (blower fan 22), the duct 3, and the branch chamber 7 correspond to the air conditioner 2 (blower fan 22), the duct 3, and the branch chamber 7 in the air conditioning system 100 shown in Fig. 1, respectively. Also, in the air conditioning system 100 shown in Fig. 7, unlike the air conditioning system 100 shown in Fig. 1, four VAV units (4A to 4D) are provided for two rooms (rooms AB and CD).

[0078] In order to make the explanation easier to understand, in Figure 7, the duct connecting the blower fan 22 and the branch chamber 7 is represented as 3z, the duct connecting the branch chamber 7 and the VAV unit 4A is represented as 3a, the duct connecting the branch chamber 7 and the VAV unit 4B is represented as 3b, the duct connecting the branch chamber 7 and the VAV unit 4C is represented as 3c, and the duct connecting the branch chamber 7 and the VAV unit 4D is represented as 3d.

[0079] That is, in the air conditioning system 100 shown in Fig. 7, the VAV unit 4A is provided between the duct 3a and the outlet of the room AB, and the VAV unit 4B is provided between the duct 3b and the outlet of the room AB. Similarly, in the air conditioning system 100 shown in Fig. 7, the VAV unit 4C is provided between the duct 3c and the outlet of the room CD, and the VAV unit 4D is provided between the duct 3d and the outlet of the room CD.

[0080] The VAV units 4A to 4D have dampers 41A to 41D, respectively. The dampers 41A to 41D are plate-shaped members having an opening angle ranging from 0 degrees to 90 degrees, for example. The VAV units 4A to 4D adjust the opening angle of the dampers 41A to 41D to adjust the pressure loss, thereby adjusting the amount of air blown out to the corresponding rooms.

[0081] In order to ensure sufficient ventilation air volume even when the dampers 41A to 41D are fully closed, they are not completely closed but are slightly open. For example, the opening degree of the dampers 41A to 41D when fully closed is 5 degrees, with the opening degree when fully closed being 0 degrees. The VAV units 4A to 4D increase the amount of air blown into the corresponding rooms by increasing the opening degree of the dampers 41A to 41D as necessary. In addition, the opening degree of the dampers 41A to 41D when fully open is, for example, 75 degrees.

[0082] In the air conditioning system 100 shown in FIG. 7, the rooms AB and CD communicate with the corridor in which the air conditioner 2 is installed so that air can circulate. For example, the air blown out from the VAV units 4A to 4D into the rooms AB and CD passes through the corridor from the rooms AB and CD and returns to the inside of the air conditioner 2 through the air intake port of the air conditioner 2. The arrows shown in FIG. 7 indicate the flow of air. In FIG. 7, the thickness of the arrow indicates the amount of air (air volume), and the thicker the arrow, the greater the air volume. For example, in the example of FIG. 7, of the four VAV units, the VAV units 4A to 4C are fully closed, and only the VAV unit 4D is fully open. Therefore, in the example of FIG. 7, the amount of air blown out to the room CD via the transport path from the air conditioner 2 (blower fan 22) to the branch chamber 7, the duct 3d, and the VAV unit 4D is greater than the amount of air blown out to each room via the other transport paths.

[0083] FIG. 8 is a diagram simulating the configuration diagram of the air conditioning system 100 shown in FIG. 7 as an electric circuit similar to FIG. 5, with the air volume replaced with a current and the air pressure replaced with a voltage.

[0084] The blower fan 22 outputs air volume and pressure, and can be regarded as a power source. The VAV units 4A to 4D change the air resistance (pressure loss) by changing the opening degree, and can be regarded as variable resistance. In addition, the ducts 3 (3a to 3d and 3z) have a non-negligible air resistance, and can be regarded as resistance.

[0085] As examples of the operation of the abnormality diagnostic device 8 according to the first embodiment, the following two typical examples of operation are given. (Operation Example 1) The opening degree of all VAV units is fixed to the first opening degree, "fully closed (5 degrees)," and the opening degree of the VAV unit to be diagnosed is changed to the second opening degree, "fully open (75 degrees)," and diagnosis is performed using the pressure sensor 9a. (Operation Example 2) The opening degrees of all VAV units are fixed to the first opening degree, "fully open (75 degrees)," and the opening degree of the VAV unit to be diagnosed is changed to the second opening degree, "fully closed (5 degrees)," and diagnosis is performed using the air flow sensor 9b. Each operation example will be described below.

[0086] <Example 1> In the first operational example, the diagnosis is performed using the pressure sensor 9a. At this time, the pressure sensor 9a is installed at a location where the change in the upstream static pressure can be measured. Here, the upstream static pressure refers to a pressure including the primary side static pressure of the VAV unit and the outlet static pressure of the blower fan 22.

[0087] An example of the installation location of the pressure sensor 9a is shown in Figures 9 and 10. Figures 9 and 10 are diagrams showing an example of the installation location of the pressure sensor 9a on Figure 8. As shown in Figures 9 and 10, the pressure sensor 9a is installed in, for example, the following locations. (Installation Example 1) Between the outlet of the blower fan 22 and the outlet of the branch chamber 7 (the gray area shown in FIG. 9). (Installation example 2) Between the outlet of the branch chamber 7 and any of the VAV units that are fully closed (the gray area shown in Figure 10).

[0088] In the case of installation example 1, when the opening degree of the VAV unit to be diagnosed is changed to full opening (second opening degree), the pressure sensor 9a can measure, as a change in the upstream static pressure, in particular a change in the outlet static pressure of the blower fan 22. Also, in the case of installation example 2, when the opening degree of the VAV unit to be diagnosed is changed to full opening (second opening degree), the pressure sensor 9a can measure, as a change in the upstream static pressure, in particular a change in the primary side static pressure of the VAV unit on the conveying path on which the pressure sensor 9a is installed. However, in the case of installation example 2, the pressure measured by the pressure sensor 9a drops to a certain degree due to pressure loss (resistance) caused by the duct connecting the branch chamber 7 and the VAV unit on the conveying path on which the pressure sensor 9a is installed. In the following description, the VAV unit on the conveying path on which the pressure sensor 9a is installed is also referred to as a "specific VAV unit."

[0089] An example of the installation location of the pressure sensor 9a in Installation Example 1 and Installation Example 2 is shown in the configuration diagram of the air conditioning system 100 shown in Fig. 7, as shown in Fig. 11. The pressure sensor 9a is installed in the gray part shown in Fig. 11, for example.

[0090] (Example of operation in case of installation example 1) Next, an example of the operation of the abnormality diagnostic device 8 when the pressure sensor 9a is installed as in Installation Example 1 will be described with reference to the flowchart of FIG.

[0091] In the following explanation, it is assumed that prior to the processing shown in the flowchart of Fig. 12, the interface unit 81 receives an instruction from the user to start diagnosis, the diagnosis mode instruction unit 82 instructs the central air-conditioning controller 6 to stop temperature control of the central air-conditioning for diagnosis, and the central air-conditioning controller 6 stops circulation of refrigerant between the air conditioners 2 and the outdoor units 5, thereby stopping the temperature control of the central air-conditioning. Also, in the following explanation, a case will be described in which the abnormality diagnosis device 8 diagnoses all four VAV units as VAV units to be diagnosed.

[0092] First, the opening degree fixation instruction unit 83 instructs the central building air-conditioning controller 6 to fix the opening degrees of the VAV units 4A to 4D, including the VAV unit to be diagnosed, to the first opening degree, "fully closed." When the central building air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to fix the opening degrees of the VAV units 4A to 4D to "fully closed" (step ST11).

[0093] Next, the air blowing instruction unit 84 instructs the central building air-conditioning controller 6 to maintain a constant rotation speed of the blower fan 22 of the air conditioner 2. When the central building air-conditioning controller 6 receives this instruction, the blower fan output setting unit 61 outputs a control signal to set the rotation speed of the blower fan 22 to a constant speed (step ST12).

[0094] Next, the threshold calculation unit 85 calculates a threshold used by the diagnosis execution unit 86 to diagnose an abnormality (step ST13).

[0095] For example, the threshold calculation unit 85 calculates the threshold based on the static pressure-air volume characteristics of the blower fan 22 and the opening degree-air resistance characteristics of the VAV unit.

[0096] To be more specific, for example, if the outlet static pressure of blower fan 22 is P, the air volume passing through the VAV unit is Fn, the opening degree of the VAV unit is An, the opening degree-air resistance characteristic of the VAV unit is R(An), and other air resistances are Cn, then the following equation (9) holds for each VAV unit. Air volume Fn = static pressure P / (resistance R(An) + resistance Cn) (9)

[0097] Furthermore, the total volume of air sent out by the air conditioner 2 is the sum of the volumes of air Fn passing through all the VAV units, and is therefore calculated using the following formula (10). Total air volume = Σ Air volume Fn = Static pressure P × Σ (1 / (Resistance R(An) + Resistance Cn)) (10)

[0098] Furthermore, if the static pressure-air volume characteristic of the blower fan 22 is P(F), then the relationship between the total air volume and the static pressure can be obtained from this P(F) as shown in the following formula (11). Static pressure P = static pressure - air volume characteristic P (total air volume) (11)

[0099] The other air resistances Cn in formula (9) are set parameters in the VAV unit, or may be replaced with appropriate representative values.

[0100] Then, the static pressure and total air volume when all VAV units are "fully closed" and when only one VAV unit is "fully open" are uniquely determined from the above formulas (10) and (11). This allows the threshold calculation unit 85 to calculate the difference (amount of change) in static pressure and total air volume when the opening of all VAV units is changed from "fully closed" to "fully open" for only one VAV unit. Here, since the diagnosis is performed using pressure sensor 9a, the threshold calculation unit 85 takes various errors into consideration and sets the threshold value to, for example, about half the value of the difference in static pressure.

[0101] Here, the static pressure-air volume characteristic P(F) of the blower fan 22 is expressed, for example, by the following formula (12): In the following formula (12), A, B, and C are predetermined coefficients. P(F)=AF 2 +BF+C (12)

[0102] If the combined resistance of all VAV units is 1, then equations (9) and (12) will result in a graph like that shown in Fig. 13. In Fig. 13, the intersection of the horizontal and vertical axes is the origin, with the air volume of the blower fan increasing to the right on the horizontal axis and the static pressure of the blower fan increasing upward on the vertical axis. The intersection of these two graphs represents the total air volume and static pressure delivered from blower fan 22 when the combined resistance is 1.

[0103] Next, the diagnosis execution unit 86 instructs the central air-conditioning controller 6 to change the opening degree of any one of the VAV units 4A to 4D that is to be diagnosed (shown as VAVn in FIG. 12) to the second opening degree, that is, "fully open". When the central air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to change the opening degree of the VAV unit to be diagnosed to "fully open" (step ST14). Note that prior to the above instruction, the diagnosis execution unit 86 acquires the measurement value by the pressure sensor 9a before the opening degree is changed to the second opening degree, that is, "fully open".

[0104] Next, the diagnosis execution unit 86 acquires the measurement value by the pressure sensor 9a after the opening degree is changed to the second opening degree, i.e., "fully open," and calculates the amount of change in the measurement value by the pressure sensor 9a before and after the change to the second opening degree. Then, the diagnosis execution unit 86 determines whether the calculated amount of change is equal to or greater than the threshold calculated in step ST13 (step ST15).

[0105] As a result, if the calculated amount of change is equal to or greater than the threshold (step ST15; YES), the diagnosis execution unit 86 diagnoses that there is no abnormality (normal) in the air transport path from the air conditioner 2 to the VAV unit being diagnosed (step ST16). On the other hand, if the calculated amount of change is not equal to or greater than the threshold (step ST15; NO), the diagnosis execution unit 86 diagnoses that there is an abnormality in the air transport path from the air conditioner 2 to the VAV unit being diagnosed (step ST17). For example, if the VAV unit being diagnosed is the VAV unit 4A, the diagnosis execution unit 86 diagnoses that there is an abnormality in the air transport path from the air conditioner 2 through the blower fan 22, duct 3z, branch chamber 7, and duct 3a to the VAV unit 4A.

[0106] Next, the diagnosis execution unit 86 instructs the central building air-conditioning controller 6 to change the opening degree of the VAV unit (VAVn) to be diagnosed to the first opening degree, which is "fully closed." When the central building air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to change the opening degree of the VAV unit to be diagnosed to "fully closed" (step ST18).

[0107] Next, the diagnosis execution unit 86 judges whether or not all VAV units have been diagnosed (step ST19). As a result, if all VAV units have been diagnosed (step ST19; YES), the process ends. On the other hand, if all VAV units have not been diagnosed (step ST19; NO), the process returns to step ST14, and the diagnosis execution unit 86 changes the VAV unit to be diagnosed to another VAV unit, and performs the process of step ST14. Thereafter, the diagnosis execution unit 86 repeats the processes of steps ST14 to ST19 until all VAV units have been diagnosed.

[0108] In the above description, an example has been described in which the threshold calculation unit 85 calculates the threshold based on the static pressure-air volume characteristics of the blower fan 22 and the opening degree-air resistance characteristics of the VAV unit. However, the threshold calculation unit 85 is not limited to this, and may calculate the threshold by another method.

[0109] For example, in a state where the opening degrees of the VAV units 4A to 4D including the VAV unit to be diagnosed are fixed to the first opening degree, i.e., "fully closed", and the rotation speed of the blower fan 22 is set to a constant value, the threshold calculation unit 85 measures the variation in the measurement values ​​of the pressure sensor 9a in the above-mentioned step ST13, and calculates the standard deviation σ of the measurement values ​​based on the measurement results. Then, the threshold calculation unit 85 may calculate a 3σ interval from the calculated standard deviation σ of the measurement values, and set the upper and lower limits of the 3σ interval as the thresholds. In this case, the diagnosis execution unit 86 acquires the pressure measured by the pressure sensor 9a after changing the opening degree of the VAV unit to be diagnosed to the second opening degree, i.e., "fully open", in the above-mentioned step ST14. Then, in the above-mentioned step ST15, when the acquired pressure is outside the range of the upper and lower limits, the diagnosis execution unit 86 may diagnose that there is no abnormality (is normal) in the air transport path from the air conditioner 2 to the VAV unit to be diagnosed. The reason is that if the acquired pressure is outside the range between the upper and lower limits, this means that there has been a certain change in pressure due to a change in the opening degree of the VAV unit being diagnosed.

[0110] (Example of operation in case of installation example 2) Next, an example of the operation of the abnormality diagnostic device 8 in the case where the pressure sensor 9a is installed as in the installation example 2 will be described with reference to the flowchart of FIG.

[0111] When pressure sensor 9a is installed as in installation example 2, abnormality diagnostic device 8 first diagnoses whether a specific VAV unit, i.e., the VAV unit on the conveying route on which pressure sensor 9a is installed, is normal or not. Then, when abnormality diagnostic device 8 diagnoses that the specific VAV unit is normal, it performs diagnosis while sequentially changing the VAV unit to be diagnosed, as in installation example 1.

[0112] First, the opening degree fixation instruction unit 83 instructs the central building air-conditioning controller 6 to fix the opening degree of the specific VAV unit to a first opening degree, "fully open", and to fix the opening degrees of the other VAV units to a second opening degree, "fully closed". When the central building air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to fix the opening degree of the specific VAV unit to "fully open", and to fix the opening degrees of the other VAV units to "fully closed" (step ST21). In the case of installation example 2, the first opening degree is set to "fully open" and the second opening degree is set to "fully closed" only when diagnosing whether this specific VAV unit is normal or not.

[0113] Next, the air blowing instruction unit 84 instructs the central building air-conditioning controller 6 to maintain a constant rotation speed of the blower fan 22 of the air conditioner 2. When the central building air-conditioning controller 6 receives this instruction, the blower fan output setting unit 61 outputs a control signal to set the rotation speed of the blower fan 22 to a constant speed (step ST22).

[0114] Next, the threshold calculation unit 85 calculates a threshold used by the diagnosis execution unit 86 to diagnose an abnormality (step ST23). At this time, the threshold calculation unit 85 calculates a threshold in the same manner as in step ST13 of Fig. 12 described above, and also calculates a threshold for diagnosing whether or not a specific VAV unit is normal.

[0115] For example, the threshold calculation unit 85 calculates the difference (amount of change) in static pressure when the opening of only one VAV unit is changed from "fully open" to "fully closed" using the above equations (10) and (11), and sets a value approximately half of that difference as the threshold for diagnosing whether a specific VAV unit is normal or not.

[0116] Next, the diagnosis execution unit 86 instructs the central building air conditioning controller 6 to change the opening degree of the specific VAV unit to the second opening degree, "fully closed". When the central building air conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to change the opening degree of the specific VAV unit to "fully closed" (step ST24). Note that prior to the above instruction, the diagnosis execution unit 86 acquires the measurement value by the pressure sensor 9a before the opening degree was changed.

[0117] Next, the diagnosis execution unit 86 acquires the measurement value by the pressure sensor 9a after the opening degree is changed, and calculates the amount of change in the measurement value by the pressure sensor 9a before and after the change in the opening degree. Then, the diagnosis execution unit 86 determines whether the calculated amount of change is equal to or greater than the threshold calculated in step ST23 (step ST25).

[0118] As a result, if the calculated amount of change is not equal to or greater than the threshold value (step ST25; NO), the diagnosis execution unit 86 diagnoses that there is an abnormality in the air transport path from the air conditioner 2 to the specific VAV unit (step ST26). In this case, the abnormality diagnosis device 8 cannot continue the diagnosis, and so notifies the user, for example via the interface unit 81, that there is an abnormality in the air transport path from the air conditioner 2 to the specific VAV unit, and ends the process. Upon receiving this notification, the user performs a prescribed operation to eliminate the abnormality, and after eliminating the abnormality, instructs the abnormality diagnosis device 8 to start diagnosis again.

[0119] On the other hand, if the calculated amount of change is equal to or greater than the threshold value (step ST25; YES), the diagnosis execution section 86 diagnoses that there is no abnormality (is normal) in the air transport path from the air conditioner 2 to the specific VAV unit (step ST27).

[0120] Next, the opening degree fixation instruction unit 83 instructs the central building air conditioning controller 6 to fix the opening degree of the specific VAV unit to "fully closed". When the central building air conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to fix the opening degree of the specific VAV unit to "fully closed" (step ST28).

[0121] Thereafter, abnormality diagnosis device 8 performs the processes of steps ST29 to ST34. Note that the process contents of steps ST29 to ST34 are similar to the process contents of steps ST14 to ST19 described in Fig. 12, and therefore repeated description will be omitted. Note that in this case, diagnosis execution unit 86 performs diagnosis on all VAV units except for a specific VAV unit as VAV units to be diagnosed.

[0122] Thus, in the case of installation example 2, the abnormality diagnosis device 8 must first diagnose whether a specific VAV unit is normal or not, but if the specific VAV unit is diagnosed as normal as a result, diagnosis can be performed in the same manner as in installation example 1.

[0123] Next, a second operational example will be described. <Example 2> In the operation example 2, the diagnosis is performed using the air volume sensor 9b. At this time, the air volume sensor 9b is installed in a location where the change in the total volume of air sent out from the air conditioner 2 or the change in the upstream static pressure can be measured.

[0124] An example of the installation location of the air flow sensor 9b is shown in Figures 15 and 16. Figures 15 and 16 are diagrams showing an example of the installation location of the air flow sensor 9b in Figure 8. As shown in Figures 15 and 16, the air flow sensor 9b is installed in, for example, the following locations. (Installation example 1) Between the air intake of the air conditioner 2 and the inlet of the branch chamber 7 (the gray area shown in FIG. 15). (Installation Example 2) Between the outlet of the branch chamber 7 and any of the VAV units that are fully open (the gray area shown in Figure 16).

[0125] In the case of installation example 1, the air flow sensor 9b can measure the change in the total air flow rate of the air sent out from the air conditioner 2 when the opening degree of the VAV unit to be diagnosed is changed to fully closed (second opening degree). Also, in the case of installation example 2, when the opening degree of the VAV unit to be diagnosed is changed to fully closed (second opening degree), the air flow sensor 9b can indirectly measure, from the change in air flow rate, the change in the upstream static pressure caused by the change in the opening degree of the VAV unit to be diagnosed, particularly the change in the primary side static pressure of the VAV unit on the transport path on which the air flow sensor 9b is installed. In the following description, the VAV unit on the transport path on which the air flow sensor 9b is installed is also referred to as a "specific VAV unit."

[0126] An example of the installation location of the air flow sensor in Installation Example 1 and Installation Example 2 is shown in the configuration diagram of the air conditioning system 100 shown in Fig. 7, as shown in Fig. 17. The air flow sensor is installed in the gray area shown in Fig. 17, for example.

[0127] (Example of operation in case of installation example 1) Next, an example of the operation of the abnormality diagnostic device 8 in the case where the air flow sensor 9b is installed as in the installation example 1 will be described with reference to the flowchart of FIG.

[0128] In the following explanation, it is assumed that prior to the processing shown in the flowchart of Figure 18, the interface unit 81 receives an instruction from the user to start diagnosis, the diagnosis mode instruction unit 82 instructs the central air conditioning controller 6 to stop the temperature control of the central air conditioning for diagnosis, and the central air conditioning controller 6 stops the circulation of refrigerant between the air conditioner 2 and the outdoor unit 5, thereby stopping the temperature control of the central air conditioning.

[0129] In the following description, the case will be described where abnormality diagnostic device 8 performs diagnosis on all four VAV units as VAV units to be diagnosed.

[0130] First, the opening degree fixation instruction unit 83 instructs the central building air-conditioning controller 6 to fix the opening degrees of the VAV units 4A to 4D, including the VAV unit to be diagnosed, to the first opening degree, "fully open." When the central building air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to fix the opening degrees of the VAV units 4A to 4D to "fully open" (step ST41).

[0131] Next, the air blowing instruction unit 84 instructs the central building air-conditioning controller 6 to maintain a constant rotation speed of the blower fan 22 of the air conditioner 2. When the central building air-conditioning controller 6 receives this instruction, the blower fan output setting unit 61 outputs a control signal to set the rotation speed of the blower fan 22 to a constant speed (step ST42).

[0132] Next, the threshold calculation unit 85 calculates a threshold used by the diagnosis execution unit 86 for diagnosing an abnormality (step ST43). Note that an example of the calculation of the threshold by the threshold calculation unit 85 is similar to the calculation example described in the first operation example.

[0133] That is, the static pressure and total air volume when all VAV units are "fully open" and when only one VAV unit is "fully closed" are uniquely determined from the above formulas (10) and (11). This allows the threshold calculation unit 85 to calculate the difference (amount of change) in static pressure and total air volume when the opening of all VAV units is changed from "fully open" to "fully closed" for only one VAV unit. Here, because the diagnosis is performed using air volume sensor 9b, the threshold calculation unit 85 takes various errors into consideration and sets the threshold to, for example, about half the difference in the total air volume.

[0134] Next, the diagnosis execution unit 86 instructs the central building air-conditioning controller 6 to change the opening degree of the VAV unit to be diagnosed (shown as VAVn in FIG. 18) among the VAV units 4A to 4D to the second opening degree, which is "fully closed". When the central building air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to change the opening degree of the VAV unit to be diagnosed to "fully closed" (step ST44). Note that prior to the above instruction, the diagnosis execution unit 86 acquires the measurement value by the air volume sensor 9b before the opening degree was changed.

[0135] Next, the diagnosis execution unit 86 acquires the measurement value of the air flow sensor 9b after the opening degree is changed to the second opening degree, i.e., "fully closed," and calculates the amount of change in the measurement value of the air flow sensor 9b before and after the change to the second opening degree. Then, the diagnosis execution unit 86 determines whether the calculated amount of change is equal to or greater than the threshold calculated in step ST43 (step ST45).

[0136] As a result, if the calculated amount of change is equal to or greater than the threshold (step ST45; YES), the diagnosis execution unit 86 diagnoses that there is no abnormality (normal) in the air transport path from the air conditioner 2 to the VAV unit being diagnosed (step ST46). On the other hand, if the calculated amount of change is not equal to or greater than the threshold (step ST45; NO), the diagnosis execution unit 86 diagnoses that there is an abnormality in the air transport path from the air conditioner 2 to the VAV unit being diagnosed (step ST47). For example, if the VAV unit being diagnosed is the VAV unit 4A, the diagnosis execution unit 86 diagnoses that there is an abnormality in the air transport path from the air conditioner 2 through the blower fan 22, duct 3z, branch chamber 7, and duct 3a to the VAV unit 4A.

[0137] Next, the diagnosis execution unit 86 instructs the central air-conditioning controller 6 to change the opening degree of the VAV unit (VAVn) to be diagnosed to the first opening degree, which is "fully open." When the central air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to change the opening degree of the VAV unit to be diagnosed to "fully open" (step ST48).

[0138] Next, the diagnosis execution unit 86 judges whether or not all VAV units have been diagnosed (step ST49). As a result, if all VAV units have been diagnosed (step ST49; YES), the process ends. On the other hand, if all VAV units have not been diagnosed (step ST49; NO), the process returns to step ST44, and the diagnosis execution unit 86 changes the VAV unit to be diagnosed to another VAV unit, and performs the process of step ST44. Thereafter, the diagnosis execution unit 86 repeats the processes of steps ST44 to ST49 until all VAV units have been diagnosed.

[0139] In the above description, an example has been described in which the threshold calculation unit 85 calculates the threshold based on the static pressure-air volume characteristics of the blower fan 22 and the opening degree-air resistance characteristics of the VAV unit. However, the threshold calculation unit 85 is not limited to this, and may calculate the threshold by another method.

[0140] For example, in a state where the opening degree of the VAV units 4A to 4D including the VAV unit to be diagnosed is fixed to the first opening degree, i.e., "fully open", and the rotation speed of the blower fan 22 is set to a constant value, the threshold calculation unit 85 measures the variation in the measurement value of the air volume sensor 9b in the above-mentioned step ST43, and calculates the standard deviation σ of the measurement value based on the measurement result. Then, the threshold calculation unit 85 may calculate a 3σ interval from the calculated standard deviation σ of the measurement value, and set the upper and lower limits of the 3σ interval as the threshold value. In this case, the diagnosis execution unit 86 acquires the air volume measured by the air volume sensor 9b after changing the opening degree of the VAV unit to be diagnosed to the second opening degree, i.e., "fully closed", in the above-mentioned step ST44. Then, in the above-mentioned step ST45, when the acquired air volume is outside the range of the upper and lower limits, the diagnosis execution unit 86 may diagnose that there is no abnormality (is normal) in the air transport path from the air conditioner 2 to the VAV unit to be diagnosed. The reason is that if the acquired air volume falls outside the range of the upper and lower limits, this means that there has been a certain change in the air volume due to a change in the opening degree of the VAV unit being diagnosed.

[0141] (Example of operation in case of installation example 2) Next, an example of the operation of the abnormality diagnostic device 8 in the case where the air flow sensor 9b is installed as in the installation example 2 will be described with reference to the flowchart of FIG.

[0142] When air flow sensor 9b is installed as in installation example 2, abnormality diagnostic device 8 first diagnoses whether a specific VAV unit, i.e., the VAV unit on the transport path where air flow sensor 9b is installed, is normal or not. Then, when abnormality diagnostic device 8 diagnoses that the specific VAV unit is normal, it performs diagnosis while sequentially changing the VAV unit to be diagnosed, as in installation example 1.

[0143] First, the opening degree fixation instruction unit 83 instructs the central building air-conditioning controller 6 to fix the opening degree of the specific VAV unit to the first opening degree, "fully closed", and to fix the opening degrees of the other VAV units to the second opening degree, "fully open". When the central building air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to fix the opening degree of the specific VAV unit to "fully closed", and to fix the opening degrees of the other VAV units to "fully open" (step ST51). In the case of installation example 2, the first opening degree is set to "fully closed" and the second opening degree is set to "fully open" only when diagnosing whether this specific VAV unit is normal or not.

[0144] Next, the air blowing instruction unit 84 instructs the central building air-conditioning controller 6 to maintain a constant rotation speed of the blower fan 22 of the air conditioner 2. When the central building air-conditioning controller 6 receives this instruction, the blower fan output setting unit 61 outputs a control signal to set the rotation speed of the blower fan 22 to a constant speed (step ST52).

[0145] Next, the threshold calculation unit 85 calculates a threshold used by the diagnosis execution unit 86 to diagnose an abnormality (step ST53). At this time, the threshold calculation unit 85 calculates a threshold in the same manner as in step ST43 of Fig. 18 described above, and also calculates a threshold for diagnosing whether a specific VAV unit is normal or not.

[0146] For example, the threshold calculation unit 85 calculates the difference (change) in the total air volume when the opening degree of all VAV units is changed from a state in which the opening degree of only one VAV unit is "fully closed" to a state in which the opening degree of all VAV units is "fully open" using the above equations (10) and (11), and sets a value approximately half of that difference as the threshold value for diagnosing whether a particular VAV unit is normal or not.

[0147] Next, the diagnosis execution unit 86 instructs the central building air conditioning controller 6 to change the opening degree of the specific VAV unit to "fully open", which is the second opening degree. When the central building air conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to change the opening degree of the specific VAV unit to "fully open" (step ST54). Note that, prior to the above instruction, the diagnosis execution unit 86 acquires the measurement value by the air volume sensor 9b before the opening degree was changed.

[0148] Next, the diagnosis execution unit 86 acquires the measurement value by the air flow sensor 9b after the opening degree is changed, and calculates the amount of change in the measurement value by the air flow sensor 9b before and after the change in the opening degree. Then, the diagnosis execution unit 86 determines whether the calculated amount of change is equal to or greater than the threshold calculated in step ST53 (step ST55).

[0149] As a result, if the calculated amount of change is not equal to or greater than the threshold value (step ST55; NO), the diagnosis execution unit 86 diagnoses that there is an abnormality in the air transport path from the air conditioner 2 to the specific VAV unit (step ST56). In this case, the abnormality diagnosis device 8 cannot continue the diagnosis, and therefore notifies the user, for example via the interface unit 81, that there is an abnormality in the air transport path from the air conditioner 2 to the specific VAV unit, and ends the process. Upon receiving this notification, the user performs a prescribed operation to eliminate the abnormality, and after eliminating the abnormality, instructs the abnormality diagnosis device 8 to start diagnosis again.

[0150] On the other hand, if the calculated amount of change is equal to or greater than the threshold value (step ST55; YES), the diagnosis execution section 86 diagnoses that there is no abnormality (is normal) in the air transport path from the air conditioner 2 to the specific VAV unit (step ST57).

[0151] Next, the opening degree fixation instruction unit 83 instructs the central building air conditioning controller 6 to fix the opening degree of the specific VAV unit to "fully open". When the central building air conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to fix the opening degree of the specific VAV unit to "fully open" (step ST58).

[0152] Thereafter, abnormality diagnosis device 8 performs the processes of steps ST59 to ST64. Note that the process contents of steps ST59 to ST64 are similar to the process contents of steps ST44 to ST49 described in Fig. 18, and therefore repeated description will be omitted. Note that in this case, diagnosis execution unit 86 performs diagnosis on all VAV units except for a specific VAV unit as VAV units to be diagnosed.

[0153] Thus, in the case of installation example 2, the abnormality diagnosis device 8 must first diagnose whether a specific VAV unit is normal or not, but if the specific VAV unit is diagnosed as normal as a result, diagnosis can be performed in the same manner as in installation example 1.

[0154] As described above, the abnormality diagnostic device 8 can perform diagnosis using the pressure sensor 9a as shown in the first operational example, or diagnosis using the air volume sensor 9b as shown in the second operational example.

[0155] In the operation example 1, an example is described in which the opening degree of the VAV unit to be diagnosed is changed from the first opening degree "fully closed (5 degrees)" to the second opening degree "fully open (75 degrees)", and in the operation example 2, an example is described in which the opening degree of the VAV unit to be diagnosed is changed from the first opening degree "fully open (75 degrees)" to the second opening degree "fully closed (5 degrees)". However, the opening degree of the VAV unit to be diagnosed is not necessarily limited to being changed between "fully open" and "fully closed". For example, the opening degree of the VAV unit to be diagnosed may be changed between "fully open" and "fully closed" (hereinafter also referred to as "intermediate opening degree").

[0156] However, when the opening of the VAV unit to be diagnosed is changed to an intermediate opening, the pressure loss in the VAV unit before and after the opening change may not change much depending on the difference in the opening. In that case, the diagnosis execution unit 86 may have difficulty in diagnosing the amount of change in pressure measured by the pressure sensor 9a or the amount of change in air volume measured by the air volume sensor 9b.

[0157] Therefore, when the diagnostic execution unit 86 changes the opening of the VAV unit to be diagnosed to an intermediate opening, it is desirable to change the opening of the VAV unit so that the change in pressure loss in the VAV unit when the opening of the VAV unit is changed is 10 times or more or 1 / 10 or less.

[0158] When the opening degree of the VAV unit to be diagnosed is changed to satisfy the above conditions, it is expected that the pressure or air volume will change to at least an extent that makes diagnosis by the diagnosis execution unit 86 possible, although this will depend on various conditions such as the actual specifications of the VAV unit and the installation manner of the VAV unit (for example, how far the VAV unit is installed from the air conditioner 2).

[0159] Also, in operation example 1, an example was described in which the opening degrees of all VAV units other than the diagnosis target were fixed to "fully closed (5 degrees)," and in operation example 2, an example was described in which the opening degrees of all VAV units other than the diagnosis target were fixed to "fully open (75 degrees)." However, the opening degrees of all VAV units other than the diagnosis target do not necessarily have to be fixed to "fully closed" or "fully open" for all VAV units.

[0160] To add to this point, the inventor of the abnormality diagnosis device 8 according to the present disclosure performed the following calculations regarding the relationship between the number of VAV units whose opening degree is "fully open" and the combined resistance, air volume, and upstream static pressure when the total number of VAV units is "24", for example.

[0161] For example, FIG. 20A is a graph showing the relationship between the number of VAV units whose opening degree is "fully open" and the combined resistance, and FIG. 20B is a graph showing the relationship between the number of VAV units whose opening degree is "fully open" and the air volume and the upstream static pressure. In FIG. 20A, the number of VAV units whose opening degree is "fully open" is shown on the horizontal axis, and the combined resistance is shown on the vertical axis, with the number of VAV units whose opening degree is "fully open" increasing toward the right on the horizontal axis, and the combined resistance increasing toward the upper direction of the vertical axis. In FIG. 20B, the number of VAV units whose opening degree is "fully open" is shown on the horizontal axis, the air volume is shown on the left vertical axis, and the static pressure is shown on the right vertical axis, with the number of VAV units whose opening degree is "fully open" increasing toward the right on the horizontal axis, and the air volume and static pressure increasing toward the upper direction of the left and right vertical axes.

[0162] For example, the graph in Fig. 20A shows that the fewer the number of VAV units that are "fully open", the greater the combined resistance, and the greater the number of VAV units that are "fully open", the smaller the combined resistance. This graph also shows that the fewer the number of VAV units that are "fully open", the greater the change in combined resistance when the number of VAV units that are "fully open" changes. This can also be seen from the fact that the shape of the graph in Fig. 20A changes more gently toward the right on the horizontal axis.

[0163] For example, the graph in Fig. 20B shows that the fewer the number of VAV units that are "fully open", the smaller the air volume and the higher the upstream static pressure, and the more the number of VAV units that are "fully open", the larger the air volume and the lower the upstream static pressure. This graph also shows that the fewer the number of VAV units that are "fully open", the larger the change in air volume and upstream static pressure when the number of VAV units that are "fully open" changes. This can also be seen from the fact that the shapes of the two graphs in Fig. 20B change more gently toward the right on the horizontal axis.

[0164] From the above, in embodiment 1, it can be said that diagnosis is easier if the openings of as many VAV units as possible other than the one to be diagnosed are fixed to "fully closed," because the amount of change in each of the combined resistance, air volume, and upstream static pressure when the opening of the VAV unit to be diagnosed is changed is greater. However, conversely, even if the openings of all VAV units other than the one to be diagnosed are fixed to "fully open," a certain amount of change occurs in the combined resistance, air volume, and upstream static pressure when the opening of the VAV unit to be diagnosed is changed, and it is possible to perform diagnosis by capturing this amount of change.

[0165] The previously described operation example 1 is an example in which diagnosis is performed based on the amount of change (amount of change in upstream static pressure) at the portion indicated by reference character U1 in Fig. 20B, and the previously described operation example 2 is an example in which diagnosis is performed based on the amount of change (amount of change in air volume) at the portion indicated by reference character U2 in Fig. 20B. However, in the first embodiment, diagnosis can be performed based on the difference (amount of change) between two adjacent points on each graph shown in Fig. 20B other than the points indicated by reference characters U1 and U2.

[0166] Next, a description will be given of the effects of the abnormality diagnostic device 8 according to embodiment 1. By being configured as described above, the abnormality diagnostic device 8 is capable of detecting an abnormality related to the air transport path in the VAV system.

[0167] As already explained, the abnormality diagnosis device 8 diagnoses that there is an abnormality in the air transport path when, for example, the change in the measurement value by the pressure sensor 9a or the air volume sensor 9b before and after the opening degree of the VAV unit being diagnosed is changed to the second opening degree is not greater than a threshold value. Possible causes of this include, for example, the following:

[0168] (1) Wiring error in the VAV unit As mentioned above, the VAV units are placed near the air outlets of each room, which are installed in the ceiling of the building. When installing the VAV units, workers work near these air outlets or inside the ceiling, and connect all the VAV units in a daisy chain with daisy chain wiring. Since all the VAV units are connected in a daisy chain with daisy chain wiring, if there is any wiring error in any of the VAV units, not only the VAV unit with the wiring error but also all the VAV units connected behind it will stop working. In this case, the opening degree cannot be changed in the VAV units that are not working, so the change in the sensor measurement value will not exceed the threshold value.

[0169] (2) Duct abnormality If there is an abnormality (such as twisting or coming loose) in the duct 3 connecting the branch chamber 7 and the VAV unit to be diagnosed, even if the opening of the VAV unit to be diagnosed is changed, the air does not pass through the VAV unit to be diagnosed, so the measurement value by the sensor does not change. Therefore, the change in the measurement value by the sensor before and after the change in the opening does not exceed the threshold value.

[0170] (3) Communication error in the VAV unit The VAV unit is equipped with a board for communicating with external devices such as the central air conditioning controller 6. If there is some abnormality in this board, the VAV unit to be diagnosed cannot acquire the control signal output from the opening setting unit 62, and cannot change the opening. Therefore, the change in the measurement value by the sensor does not exceed the threshold value.

[0171] (4) Wiring error between the VAV unit board and the motor The circuit board of the VAV unit is connected to a motor for controlling the opening of the damper. If there is an abnormality (e.g., a break) in the wiring connecting this circuit board and the motor, the VAV unit to be diagnosed cannot change the opening even if it receives a control signal output from the opening setting unit 62. Therefore, the change in the measurement value by the sensor does not exceed the threshold value.

[0172] In other words, when an event such as those described above in (1) to (4) occurs in the VAV unit or duct to be diagnosed, the abnormality diagnostic device 8 can diagnose that there is an abnormality in the air transport path from the air conditioner 2 to the VAV unit to be diagnosed. Therefore, the user can understand that an event such as those described above in (1) to (4) has occurred by actually checking the transport path that has been diagnosed as having an abnormality.

[0173] Also, for example, with regard to (2) above, in the past, after construction, the user had to go around to each air outlet in each room and use an air flow meter to check whether air was coming out of the air outlet, thereby checking for duct abnormalities, which was very cumbersome for the user. In this regard, in the first embodiment, the abnormality diagnosis device 8 can also diagnose abnormalities in the air transport path caused by duct abnormalities, so that the user no longer needs to go around to each air outlet in each room after construction, eliminating the need for cumbersomeness.

[0174] Furthermore, in the first embodiment, the abnormality diagnostic device 8 can perform the above-mentioned diagnosis as long as one pressure sensor 9a or one air volume sensor 9b is provided in the air conditioning system 100. As a result, in the first embodiment, the addition of configuration to the air conditioning system 100 can be kept to a minimum.

[0175] For example, as already described, in the air conditioning system 100, even if an air volume sensor for measuring the volume of air sent out by the VAV units 4A to 4C or a pressure sensor for measuring the air pressure is not provided, the VAV unit control device 1 can realize control with reduced influence of disturbance. On the other hand, in the air conditioning system 100, in order to perform diagnosis by the abnormality diagnosis device 8, it is sufficient to provide one pressure sensor 9a or one air volume sensor 9b. That is, in the first embodiment, the air conditioning system 100 can easily and at low cost achieve both the effect of the VAV unit control device 1 and the effect of the abnormality diagnosis device 8 by providing only one pressure sensor 9a or one air volume sensor 9b. However, the abnormality diagnosis device 8 does not necessarily need to be provided in the air conditioning system 100 together with the VAV unit control device 1, and may be provided alone in the air conditioning system 100.

[0176] <Modification> Finally, a modified example of the abnormality diagnosis device 8 according to the first embodiment will be described. In the above description, an example has been described in which the diagnosis execution unit 86 diagnoses an abnormality based on the amount of change in air volume or pressure in the transport path before and after a change in the opening degree of the VAV unit to be diagnosed. On the other hand, the diagnosis execution unit 86 may diagnose an abnormality based on the amount of change in the number of rotations of the blower fan 22 before and after a change in the opening degree of the VAV unit to be diagnosed.

[0177] In this case, for example, the opening degree fixation instruction unit 83 instructs the central building air-conditioning controller 6 to fix the opening degrees of the VAV units 4A to 4D including the VAV unit to be diagnosed to the first opening degree. When the central building air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to fix the opening degrees of the VAV units 4A to 4D to the first opening degree.

[0178] The airflow instruction unit 84 also instructs the central air-conditioning controller 6 to control the rotation speed of the blower fan 22 of the air conditioner 2 so that the air volume or pressure in the transport path is constant. The target value of the air volume or pressure in the transport path is given by, for example, the user.

[0179] When the central air-conditioning controller 6 receives this instruction, the blower fan output setting unit 61 outputs a control signal to control the rotation speed of the blower fan 22 so that the air volume or pressure in the transport path is constant. Note that, for example, feedback control is used for this control, in which the air volume or pressure in the transport path is set as a target value and the rotation speed of the blower fan 22 is set as a control variable.

[0180] After the rotation speed of the blower fan 22 is controlled and the opening degree of the VAV unit to be diagnosed is fixed to the first opening degree, the diagnosis execution unit 86 instructs the central building air-conditioning controller 6 to change the opening degree of the VAV unit to be diagnosed among the VAV units 4A to 4D to the second opening degree. When the central building air-conditioning controller 6 receives this instruction, the opening degree setting unit 62 outputs a control signal to change the opening degree of the VAV unit to be diagnosed to the second opening degree. At this time, if there is no abnormality in the air transport path from the air conditioner 2 to the VAV unit to be diagnosed, the change in the opening degree causes the air volume or pressure to deviate from the target value in the transport path. At this time, since the rotation speed of the blower fan 22 is under the above control, the rotation speed of the blower fan 22 is changed to return the air volume or pressure deviated from the target value to the target value. The diagnosis execution unit 86 acquires the amount of change in the rotation speed of the blower fan 22 at this time.

[0181] In addition, the change in the rotation speed of the blower fan 22 may be calculated, for example, by the blower fan output setting unit 61, and in that case, the diagnosis execution unit 86 may obtain the change in the rotation speed of the blower fan 22 from the blower fan output setting unit 61.

[0182] Then, the diagnosis execution section 86 diagnoses an abnormality in the air transport path from the air conditioner 2 to the VAV unit being diagnosed, based on the acquired amount of change in the rotation speed of the blower fan 22.

[0183] For example, the diagnosis execution unit 86 determines whether the acquired amount of change in the rotation speed of the blower fan 22 is equal to or greater than a threshold, and if the amount of change is equal to or greater than the threshold, diagnoses that there is no abnormality in the air transport path from the air conditioner 2 to the VAV unit being diagnosed (is normal). On the other hand, if the acquired amount of change in the rotation speed of the blower fan 22 is less than the threshold, the diagnosis execution unit 86 diagnoses that there is an abnormality in the air transport path from the air conditioner 2 to the VAV unit being diagnosed.

[0184] The threshold value may be calculated by, for example, the threshold value calculation unit 85. For example, the threshold value calculation unit 85 may calculate, by simulation, an amount of change in the rotation speed of the blower fan 22 when the opening degree of any of the VAV units is changed while the rotation speed of the blower fan 22 is under the above-mentioned control, and may set a value that is about half of the calculated amount of change as the threshold value, taking various errors into consideration.

[0185] In this way, the diagnosis execution unit 86 may diagnose an abnormality based on the amount of change in the rotation speed of the blower fan 22 before and after a change in the opening degree of the VAV unit to be diagnosed. Even in this case, the diagnosis execution unit 86 can perform a diagnosis similar to the diagnosis based on the amount of change in the air volume or pressure in the transport path described above.

[0186] As described above, according to the first embodiment, the abnormality diagnostic device 8 is provided for each of a plurality of air conditioned spaces, and in an air conditioning system 100 having VAV units that adjust the volume of air blown out from the air conditioner 2 to the corresponding air conditioned space, the abnormality diagnostic device 8 is an abnormality diagnostic device that diagnoses an abnormality related to the transport path of the air blown out from the air conditioner 2, and includes an opening degree fixation instruction unit 83 that instructs the opening degree of a VAV unit to be diagnosed among the plurality of VAV units to be fixed to a first opening degree, and an instruction unit that instructs the rotation speed of the blower fan 22 of the air conditioner 2 to be kept constant. and a diagnosis execution unit 86 that issues an instruction to change the opening of the VAV unit to be diagnosed to a second opening after the rotation speed of the blower fan 22 is kept constant based on an instruction from the blower instruction unit 84 and the opening of the VAV unit to be diagnosed is fixed to a first opening based on an instruction from the opening fixation instruction unit 83, and that diagnoses an abnormality related to the air transport path from the air conditioner 2 to the VAV unit to be diagnosed based on an amount of change in air volume or pressure in the transport path before and after the change to the second opening based on the instruction. This makes it possible for the abnormality diagnosis device 8 according to the first embodiment to diagnose an abnormality related to the air transport path in the VAV system.

[0187] Furthermore, the diagnosis execution unit 86 diagnoses abnormalities in the air transport paths from the air conditioner 2 to each of the multiple VAV units by repeating the diagnosis while sequentially changing the VAV unit to be diagnosed. This allows the abnormality diagnosis device 8 according to embodiment 1 to diagnose abnormalities in each of the multiple VAV units.

[0188] Furthermore, the abnormality diagnosis device 8 includes a threshold calculation unit 85 that calculates a threshold used for diagnosis by the diagnosis execution unit 86, and the diagnosis execution unit 86 performs diagnosis based on a comparison result between the threshold calculated by the threshold calculation unit 85 and the amount of change in air volume or pressure in the transport path before and after changing the opening degree of the VAV unit to be diagnosed. This allows the abnormality diagnosis device 8 according to the first embodiment to accurately diagnose abnormalities related to the air transport path.

[0189] Furthermore, the threshold calculation unit 85 calculates the threshold using the air volume-static pressure characteristics of the blower fan 22 of the air conditioner 2 and the opening-air resistance characteristics of each of the multiple VAV units. This allows the abnormality diagnosis device 8 according to the first embodiment to appropriately calculate the threshold used for diagnosing an abnormality.

[0190] Furthermore, threshold calculation unit 85 measures the variation in the measurement value of the air volume or pressure in the conveying path after the opening of the VAV unit to be diagnosed is fixed to the first opening based on an instruction from opening fixation instruction unit 83 and the rotation speed of blower fan 22 is made constant based on an instruction from air blow instruction unit 84, and calculates a threshold based on the standard deviation of the measurement value obtained based on the measurement result. This allows abnormality diagnosis device 8 according to embodiment 1 to appropriately calculate the threshold value used in diagnosing an abnormality.

[0191] Furthermore, diagnosis execution unit 86 changes the opening of the VAV unit to be diagnosed so that the amount of change in pressure loss in the VAV unit when the opening of the VAV unit to be diagnosed is 10 times or more, or 1 / 10 or less. This allows abnormality diagnosis device 8 according to embodiment 1 to perform diagnosis based on the amount of change in pressure or air volume before and after the opening is changed.

[0192] Furthermore, opening degree fixation instruction unit 83 issues an instruction to fix the opening degree of each of the multiple VAV units to fully closed, and diagnosis execution unit 86 issues an instruction to change the opening degree of a VAV unit to be diagnosed among the multiple VAV units to fully open, and diagnoses an abnormality in the air transport path from the air conditioner 2 to the VAV unit to be diagnosed based on the amount of change in pressure in the transport path before and after the opening degree is changed based on the instruction. This allows abnormality diagnosis device 8 according to embodiment 1 to easily diagnose an abnormality in the air transport path in a VAV system based on the amount of change in pressure.

[0193] Furthermore, opening degree fixation instruction unit 83 issues an instruction to fix the opening degree of each of the multiple VAV units to fully open, and diagnosis execution unit 86 issues an instruction to change the opening degree of a VAV unit to be diagnosed among the multiple VAV units to fully closed, and diagnoses an abnormality in the air transport path from the air conditioner 2 to the VAV unit to be diagnosed based on the amount of change in air volume in the transport path before and after the opening degree is changed based on the instruction. This allows abnormality diagnosis device 8 according to embodiment 1 to easily diagnose an abnormality in the air transport path in the VAV system based on the amount of change in air volume.

[0194] The abnormality diagnosis device 8 also includes an opening degree fixing instruction unit 83 that instructs the opening degree of the VAV unit to be diagnosed among the multiple VAV units to be fixed to a first opening degree, an airflow instruction unit 84 that instructs the rotation speed of the blower fan 22 of the air conditioner 2 to be controlled so that the air volume or pressure in the conveying path is constant, and a diagnosis execution unit 86 that instructs the opening degree of the VAV unit to be diagnosed to be changed to a second opening degree after the rotation speed of the blower fan 22 is controlled based on the instruction from the airflow instruction unit 84 and the opening degree of the VAV unit to be diagnosed is fixed to the first opening degree based on the instruction from the opening degree fixing instruction unit 83, and diagnoses an abnormality related to the conveying path of air from the air conditioner 2 to the VAV unit to be diagnosed based on the change in the rotation speed of the blower fan 22 before and after the change to the second opening degree based on the instruction. As a result, the abnormality diagnosis device 8 according to the first embodiment can diagnose an abnormality related to the conveying path of air in a VAV system.

[0195] According to the first embodiment, the air conditioning system 100 includes an abnormality diagnostic device 8, an air conditioner 2, a plurality of VAV units, and a pressure sensor 9a that measures the pressure in the transport path or an air volume sensor 9b that measures the air volume in the transport path. This makes it possible for the air conditioning system 100 according to the first embodiment to diagnose abnormalities related to the air transport path in the VAV system.

[0196] In addition, within the scope of the present disclosure, any of the components of the embodiments may be modified or any of the components of the embodiments may be omitted. For example, the numbers of VAV units and the numbers of air-conditioned spaces in the air-conditioning system 100 described above are merely examples, and numbers other than those described above may be used. [Explanation of symbols]

[0197] 1 VAV unit control device 2 Air conditioner 3 Duct 3a Duct 3b Duct 3c Duct 3d duct 3z Duct 4A VAV unit 4B VAV unit 4C VAV unit 4D VAV unit 5 Outdoor unit 6. Central air conditioning controller 7 Branching chamber 8. Abnormality diagnosis device 9a Pressure sensor 9b Air flow sensor 11 Air volume calculation section 12 Fan static pressure calculation section 13 Primary static pressure calculation section 14 Resistance calculation section 15 Opening degree calculation section 16 Correction section 21 Heat exchanger 22 Blower fan 41A Damper 41B Damper 41C Damper 41D Damper 51 Compressor 52 Heat exchanger 61 Blower fan output setting section 62 Opening degree setting section 81 Interface section 82 Diagnostic mode indicator 83 Opening degree fixed indication part (opening degree fixed part) 84 Airflow instruction unit (airflow setting unit) 85 Threshold calculation unit 86 Diagnostic Execution Unit 100 Air Conditioning System

Claims

1. An abnormality diagnosis device for diagnosing an abnormality related to a transport path of air sent out from an air conditioner in an air conditioning system including a VAV unit provided for each of a plurality of air-conditioned spaces and adjusting an air volume of air sent out from the air conditioner to the corresponding air-conditioned space, comprising: an opening degree fixing instruction unit that instructs to fix an opening degree of a VAV unit to be diagnosed among the plurality of VAV units to a first opening degree; An airflow instruction unit that instructs the air conditioner to keep the rotation speed of the air blower fan constant; a diagnosis execution unit that instructs to change the opening of the VAV unit to be diagnosed to a second opening after the rotation speed of the blower fan is kept constant based on an instruction from the air blowing instruction unit and the opening of the VAV unit to be diagnosed is fixed to a first opening based on an instruction from the opening fixation instruction unit, and diagnoses an abnormality related to the air transport path from the air conditioner to the VAV unit to be diagnosed based on an amount of change in air volume or pressure in the transport path before and after the change to the second opening based on the instruction; An abnormality diagnosis device comprising:

2. The diagnosis execution unit is The diagnosis is repeated while sequentially changing the VAV unit to be diagnosed, Diagnosing an abnormality in an air transport path from the air conditioner to each of the plurality of VAV units 2. The abnormality diagnosis device according to claim 1.

3. a threshold calculation unit that calculates a threshold used in the diagnosis by the diagnosis execution unit; The diagnosis execution unit is The diagnosis is performed based on a comparison result between the threshold calculated by the threshold calculation unit and the amount of change in air volume or pressure in the transport path before and after the opening degree of the VAV unit to be diagnosed is changed.

3. The abnormality diagnosis device according to claim 1 or 2.

4. The threshold calculation unit The threshold value is calculated using the air volume-static pressure characteristics of the blower fan of the air conditioner and the opening degree-air resistance characteristics of each of the plurality of VAV units.

4. The abnormality diagnosis device according to claim 3.

5. The threshold calculation unit The opening degree of the VAV unit to be diagnosed is fixed to a first opening degree based on an instruction from the opening degree fixing instruction unit, and the rotation speed of the blower fan is made constant based on an instruction from the air blowing instruction unit. After that, a variation in a measurement value of an air volume or a pressure in the conveying path is measured, and the threshold value is calculated based on a standard deviation of the measurement value obtained based on the measurement result.

4. The abnormality diagnosis device according to claim 3.

6. The diagnosis execution unit is The opening degree of the VAV unit to be diagnosed is changed so that the change amount of the pressure loss in the VAV unit when the opening degree of the VAV unit to be diagnosed is 10 times or more or 1 / 10 or less.

3. The abnormality diagnosis device according to claim 1 or 2.

7. The opening degree fixing instruction unit is Instructing each of the plurality of VAV units to be fixed at a fully closed position; The diagnosis execution unit issues an instruction to change the opening degree of a VAV unit to be diagnosed among the plurality of VAV units to full open, and diagnoses an abnormality in an air transport path from the air conditioner to the VAV unit to be diagnosed based on an amount of change in pressure in the transport path before and after the change in opening degree based on the instruction.

3. The abnormality diagnosis device according to claim 1 or 2.

8. The opening degree fixing instruction unit is instructing that the opening degree of each of the plurality of VAV units be fixed to a fully open state; The diagnosis execution unit issues an instruction to change the opening degree of a VAV unit to be diagnosed among the plurality of VAV units to a fully closed state, and diagnoses an abnormality in an air transport path from the air conditioner to the VAV unit to be diagnosed based on an amount of change in air volume in the transport path before and after the change in opening degree based on the instruction.

3. The abnormality diagnosis device according to claim 1 or 2.

9. An abnormality diagnosis device for diagnosing an abnormality related to a transport path of air sent out from an air conditioner in an air conditioning system including a VAV unit provided for each of a plurality of air-conditioned spaces and adjusting an air volume of air sent out from the air conditioner to the corresponding air-conditioned space, comprising: an opening degree fixing instruction unit that instructs to fix an opening degree of a VAV unit to be diagnosed among the plurality of VAV units to a first opening degree; an airflow instruction unit that instructs to control the rotation speed of the blower fan of the air conditioner so that the air volume or pressure in the conveying path is constant; a diagnosis execution unit that instructs to change the opening of the VAV unit to be diagnosed to a second opening after the rotation speed of the blower fan is controlled based on an instruction from the air blowing instruction unit and the opening of the VAV unit to be diagnosed is fixed to a first opening based on an instruction from the opening fixation instruction unit, and diagnoses an abnormality in an air transport path from the air conditioner to the VAV unit to be diagnosed based on an amount of change in the rotation speed of the blower fan before and after the change to the second opening based on the instruction; An abnormality diagnosis device comprising:

10. The abnormality diagnosis device according to claim 1 or 2, The air conditioner; The plurality of VAV units; a pressure sensor that measures a pressure in the conveying path, or an air volume sensor that measures an air volume in the conveying path; An air conditioning system comprising:

11. In an air conditioning system including a VAV unit provided for each of a plurality of air-conditioned spaces, the VAV unit adjusting the volume of air blown out from an air conditioner provided for each of the plurality of air-conditioned spaces to a corresponding air-conditioned space, the VAV unit comprising: an opening degree fixing instruction unit instructing to fix an opening degree of a VAV unit to be diagnosed among the plurality of VAV units to a first opening degree; a step of an air blowing instruction unit instructing to keep the rotation speed of the air blowing fan of the air conditioner constant; a step of: after the rotation speed of the blower fan is kept constant based on an instruction from the air blowing instruction unit and the opening degree of the VAV unit to be diagnosed is fixed to a first opening degree based on an instruction from the opening degree fixing instruction unit, a diagnosis execution unit issues an instruction to change the opening degree of the VAV unit to be diagnosed to a second opening degree, and diagnosing an abnormality related to the air transport path from the air conditioner to the VAV unit to be diagnosed based on an amount of change in air volume or pressure in the transport path before and after the change to the second opening degree based on the instruction; The abnormality diagnosis method includes the steps of:

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