JPH0510573B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a duct type air conditioner that employs a variable air volume control method that independently adjusts the room temperature of each room, and particularly relates to its control. .

[Conventional technology]

In air conditioners, air ducts are used to
Variable air volume control (hereinafter referred to as VAV) is added to the central air conditioning system that performs air conditioning (hereinafter referred to as air conditioning) by distributing temperature-controlled air to each room.
A variety of systems have been developed to which the control system is applied. Here, VAV control means to keep the air temperature constant and adjust the damper opening degree of each room according to the heat load status of each room, thereby varying the air volume and keeping the room temperature constant at the set value. It is something. Buildings that employ this type of air conditioning control are offices and other buildings, and in most cases, all the rooms are air-conditioned, and the hours of the day are constant. In addition, since the indoor environment is determined by law, ventilation is always performed, and even if there is an air conditioning load, there is at least a heat load associated with ventilation, and an air volume is required for ventilation.

There is a method of using a diaphragm type damper and a bypass type damper to adjust the air flow rate in VAV control, but the conventional technology that uses a diaphragm type damper is
Figure 2.10a of Publication No. 196029 and the Refrigeration and Air Conditioning Handbook (New Edition, 4th Edition, Advanced Edition) published by the Japan Refrigeration Association are known. Figure 5 is a characteristic diagram showing the relationship between the air flow rate and the air temperature for the cooling load shown in Figure 2.14 of the Refrigeration and Air Conditioning Handbook.As the load decreases, the air flow rate remains constant. However, when the load falls below a certain value, the amount of air blown is fixed, and only the temperature of the air blown is varied to balance it with the heat load. This type of control ensures the minimum amount of air flow (ventilation amount) even under constant load. However, if there is a large difference in the heat load between rooms, it is not possible to accurately control the room temperature unless a reheating coil or the like is installed in each room. Note that control in which the air blowing temperature is varied while keeping the air blowing amount constant is called constant air volume control (hereinafter referred to as CAV control).

[Problem that the invention seeks to solve]

Conventional building air conditioners were controlled as described above, but when VAV control is used for residential air conditioning, the usage method is different from building air conditioning. First, in the case of houses, the number of rooms that require air conditioning varies greatly depending on the time of day, ranging from a minimum of one room to a maximum of all rooms, and the number of rooms is also small. In addition, since ventilation is often not performed, the amount of air blown into each room is greatly reduced (down to 0% damper opening). Therefore, the total heat load varies greatly depending on the time of day and other factors.
Now, as a heat source device for an air conditioner, it is possible to use a variable capacity heat pump using an imperter or the like, or a variable capacity gas furnace, but the range in which the capacity can be controlled is limited. In addition, even if the heat load is small, the capacity cannot be lowered to the minimum value in order to maintain a constant air temperature, and for this reason, VAV
When only one room is air-conditioned by control, there is a problem in that the heat source equipment starts and stops frequently.

The object of the present invention is to provide an air conditioner that can optimally control the amount of air blown and the temperature of air blown depending on the number of rooms to be air-conditioned.

[Means for solving problems]

An air conditioner according to the present invention includes a variable capacity heat source device, a variable capacity blower, a plurality of dampers inserted in a duct, a pressure detector and a temperature detector provided in the duct, and a room A number detection means for detecting the number of air conditioned rooms based on a detection signal from a thermostat or the like, and a control method selection means for selecting control between variable air volume and constant air volume based on the output of the air conditioned room number detection means. It is something that

[Effect]

In this invention, the air-conditioned room number detection means detects the current number of air-conditioned rooms from the operation and stop state of the air conditioning in each room set by a room thermostat, etc., and the control method selection means detects the output of the air-conditioned room number detection means. In the case of one room, the control of the damper, blower, and heat source device is set to constant air volume control, and in the case of multiple rooms, variable air volume control is selected.

〔Example〕

FIG. 1 is an overall configuration diagram showing an embodiment of an air conditioner according to the present invention. As is clear from FIG. 1, this embodiment includes a variable capacity heat source device 1 such as a heat pump that generates cold and hot air, a variable capacity blower 2 connected to this heat source device 1, and a variable capacity blower 2 that distributes the cold and hot air. a duct 3, a plurality of dampers 4a to 4d provided in this duct, a pressure detector 5 for detecting the pressure inside the duct 3, a temperature detector 6 for detecting the temperature, and a plurality of room thermostats 7a to 7d.
and the room thermostats 7a to 7d.
The number of rooms that are currently being air-conditioned is detected by the air-conditioned room number detection means 8 based on the output signal such as, and the damper 4, blower 2, and heat source device 1 are controlled based on the output of the detection means 8 to perform variable air volume control. It is constituted by control method selection means 9 which selects either constant air volume control or constant air volume control.

FIG. 2 is a system configuration diagram of an air conditioner used in the embodiment of FIG. 1. In the figure, reference numeral 10 denotes an indoor unit 12 which is installed in the ceiling of a building and includes a heat exchanger 11 connected to the heat source device 1 and the blower 2.
A to 12d are four branch ducts of the duct 3 connected to the indoor unit 10, and the dampers 4a to 4d are installed in the middle. 13a~
13d is an air outlet attached to the ceiling surface at the end of the branch ducts 12a to 12d, 14a to 14d are ring air vents provided at the bottom of each room's door, 15 is a main ring air vent provided on the ceiling surface of the corridor, 16 is a return air duct connecting the main ring air outlet 15 with the indoor unit 10; 17;
is a control device that controls the entire air conditioner. Although not shown, the room thermostats 7a to 7d installed in each room include an operation switch for selecting whether or not to air condition the room, a room temperature detector for detecting the room temperature, and a room temperature for inputting the set room temperature. A setting device is provided. Further, the pressure detector 5 and the temperature detector 6 are installed inside the duct 3.

FIG. 3 is a circuit diagram showing the electrical connections of the entire system, most of which are housed in the control device 17. 18 is a microcomputer provided in the control device 17, and is a microcomputer provided in the input circuit 1.
9, CPU 20, memory 21, timer 22,
An output circuit 23 is provided. Reference numeral 24 denotes an analog multiplexer to which the room thermostats 7a to 7d, the pressure detector 5, and the temperature detector 6 are connected, and is connected to the input circuit 19 via the A/D converter 25.

Reference numeral 26 denotes a heat source device controller for controlling the capacity of the heat source device 1, and is connected to the output circuit 23 via a photocoupler 27a. A blower controller 28 controls the capacity of the blower 2, and is connected to the output circuit 23 via a photocoupler 27b. A damper controller 29 controls the opening degree of the damper 4, and is connected to the output circuit via a photocoupler 27c. 30 is the heat source controller 26, the blower controller 28, and the damper controller 2.
This is a power source that supplies power to 9.

Next, the operation of the above embodiment will be explained with reference to the control flowchart shown in FIG. First, in step 31, a signal indicating whether or not each room is being air-conditioned is input from each room thermostat 7a to 7d to the microcomputer 18 via the analog multiplexer 24 and A/D converter 25. At the same time, in step 32, each room thermostat 7a to 7b outputs the set temperature T _O of each room.
and the current room temperature T _R value is microcomputer 1
8. In the next step 33, the number of air-conditioned rooms is determined, and if two or more rooms are being air-conditioned, the process moves to step 34. In step 34, the opening degree of the dampers 4a to 4d in the room being air-conditioned is controlled based on the difference between T _O and T _R. Control signals for the dampers 4a to 4d are transmitted from the microcomputer 18 to the damper control device via the photocoupler 27c to change the opening degrees of the dampers 4a to 4d. In step 35, the pressure sensor 5 and the temperature sensor 6 detect the duct 3 after controlling the dampers 4a to 4d.
Signals of internal pressure and air temperature are input to the microcomputer 18. Then, in the next step 36, the capacity of the blower 2 is changed by the blower controller 28 so that the pressure inside the duct 3 is maintained at the set pressure. In step 37, the number of air-conditioned rooms is judged again, and if two or more rooms are being air-conditioned, the process moves to step 38, where the heat source equipment controller 2
6, the capacity of the heat source device 1 is changed so that the air blowing temperature in the duct 3 is maintained at the set temperature. The above control becomes VAV control. If the number of air-conditioned rooms is determined to be one in steps 33 and 37, steps 39 and 40 are executed. In step 39, the dampers 4a~ of the room being air-conditioned are
4d is fully opened, and dampers 4a to 4 in other rooms
d is fully closed. In step 40, the T _O and T _R of the room being air-conditioned that were input in step 32 above are input.
The capacity of the heat source device 1 is controlled based on the difference. In other words, when the temperature difference is large, the capacity is controlled to be large, and when it is small, the capacity is controlled to be small. In addition, in this case, the control of the blower 2 is controlled by the previous VAV.
The pressure is controlled to the same set pressure as during control.
CAV control is performed.

Through the above control, the capacity of the heat source device 1 is controlled according to the heat load, and the blowing temperature is varied during air conditioning of one room. As a result, the heat source unit 1 is operated at a capacity that is balanced with the heat load, and in order to maintain the air blowing temperature as in the past, it is operated at a capacity that is greater than the heat load, causing the room temperature to exceed the set value. This prevents the heat source device 1 from frequently turning on and off. Furthermore, when one room is being air-conditioned, the dampers 4a to 4d of the room being air-conditioned are fully opened, so the pressure loss in the blower system is small, and the power of the blower 2 is also saved.

In the above embodiment, signals from the room thermostats 7a to 7d are used to detect the number of rooms being air-conditioned, but these may also be signals from a controller (not shown).

In addition, in the above embodiment, the number of operation switches set by the user using a room thermostat etc. was used to determine the number of air conditioned rooms, but the heat load is small and as a result, the damper is fully closed or close to fully closed. Rooms with high temperatures may also be treated as non-air conditioned rooms.

Further, in the above embodiment, the set pressure and temperature within the duct 3 are controlled to be constant, but the present invention may be applied to control in which these are varied within a fixed range due to heat load or the like.

Further, in the above embodiment, the pressure detector 5 is provided in the duct 3 to control the pressure at a constant level, but if the pressure can be controlled at a substantially constant level by other means, the pressure detector 5 may not be used.

〔Effect of the invention〕

As described above, according to the present invention, since variable air volume control and constant air volume control are used depending on the number of rooms being air-conditioned, the number of turns on and off of the heat source unit when air-conditioning a single room is reduced, and stable operation is achieved. I can do it.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an embodiment of an air conditioner according to the present invention, Fig. 2 is a system configuration diagram using the air conditioner shown in Fig. 1, and Fig. 3 shows the electrical system of Fig. 2. FIG. 4 is a flowchart showing the control operations shown in FIGS. 1 to 3, and FIG. 5 is a characteristic diagram showing the relationship between cooling load and air volume of a conventional air conditioner. 1 is a heat source machine, 2 is a blower, 3 is a duct, 4a~
4d is a damper, 5 is a pressure detector, 6 is a temperature detector, 7a to 7d are room thermostats, 8 is air conditioned room number detection means, and 9 is control method selection means. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A variable capacity heat source device that generates hot or cold air, a variable capacity blower connected to this heat source device, a duct that distributes the cold and hot air supplied from this blower, and each branch of this duct. a damper for adjusting air volume placed in each room; a pressure detector for detecting air blowing pressure in the duct; a temperature detector for detecting air blowing temperature in the duct; and a room thermostat placed in each room. In an air conditioner equipped with the above-mentioned room thermostat or the like, the number of air conditioned rooms detecting means detects the operating and stopping state of the air conditioning in each room set by the room thermostat etc., and control method selection means for selecting either constant air volume control or variable air volume control for damper, blower, and heat source equipment, and when only one room is being air-conditioned, the damper for that room is fully opened. An air conditioner characterized by completely closing dampers in other rooms and controlling the air volume at a constant rate.