JPH03186137A - Duct type air conditioner - Google Patents

Abstract

PURPOSE:To carry out air conditioning for an individual room to be air conditioned at thermal load which fails to exceed the capacity control limit for heat supply equipment by installing an air volume set point station setter which sets a specified small air volume when air conditioning is suspended while a too small air volume signal is being transmitted from a total air volume detection means. CONSTITUTION:In the case when the thermal load of a room 8 to be air conditioned is small and a supply air volume is small, it is detected by a total air volume detection means 23 so that a too small air volume signal may be output. Responding with the output of the too small air volume signal, an air volume set point station setter 21 of the air conditioned room 8, which has suspended its air conditioning operation, sets a target air volume to a very small value. Therefore, the supply air volume is increased so that excess heating value generated by the lack of capacity control of heating supply equipment 4 may be dispersed to the air conditioned room 8 which has suspended its air conditioning operation and hence requires no air conditioning operation, thereby continuing the air conditioning operation within a capacity control range of the heating supply equipment 4. This construction makes it possible to provide a duct type air conditioner capable of performing separate air conditioning operation even for the air conditioned room 8 whose thermal load is small and below the control limit of the heating supply equipment 4.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention employs a variable air volume control system that blows cold and hot air to each room through a duct, and adjusts the airflow volume for each room to individually condition the air. This invention relates to duct type air conditioners, and particularly to improvements in control during low capacity operation.

[Prior art] A variable air volume control type air conditioning system uses a blower to supply cold or hot air to each room through a duct, and then controls the damper and blower installed in the middle of the duct to distribute the air to each room. This system air-conditions each room individually by adjusting the amount of air supplied.

Many air conditioning systems and control methods of this type have been proposed, and a representative example is the Refrigeration and Air Conditioning Handbook (New Edition/4th Edition Applied Edition) published by the Japan Refrigeration Association, Chapter 2, Air Conditioning Systems, page 41. There is an air conditioning system shown in Figure 2.10(a).

Figure 5 is a configuration diagram showing a conventional duct type air conditioner using this air conditioning system. In Figure 1, (1) is the capacity +-kk.
The indoor unit (4) has a built-in Df modified air blower fi (2) and an indoor heat exchanger (3).
5) A variable capacity heat source machine that is an outdoor unit that is connected to this via a heat pump refrigerant circuit and forms a heat pump refrigerant circuit.

(6) is a main duct that communicates with the air outlet of the indoor unit (1), (7) is a branch duct that branches from this main duct (6) according to the number of each air-conditioned room (8), (9) is a throttle-type air volume control unit that is attached to each branch duct (7) and adjusts the amount of air blown to each air-conditioned room (8), and (io) is rotatably attached within the air volume control unit (9). A damper that adjusts the passing air volume, (11) an air outlet opening into the conditioned room (8), and (12) an indoor setting device installed in each conditioned room (8) that has room temperature detection and room temperature setting functions. , (1
3) is an air inlet located below the door of the air-conditioned room (8), (14) is a ceiling air inlet located on the ceiling of the hallway outside the air-conditioned room (8), ( 15) is the ceiling inlet (1
4) and a suction duct that communicates with the suction port of the indoor unit (1);
(16) is an air temperature detector that detects the air temperature from the blower (2) in the main duct (6), and (17) also detects the air blow pressure from the indoor fan (2) in the main duct (6). It is a pressure sensor that

Next, its operation will be explained. Each indoor setting device (12)
, the opening degree of the damper (10) is adjusted to an arbitrary position depending on the temperature difference between the set temperature set by the user and the detected current room temperature. The line pressure in the main duct (6) changes depending on the opening degree of this damper (lO), and this change in pressure is detected by the pressure detector (17), which becomes the preset set pressure. Indoor blower (2)
) is controlled. Along with this change in air flow rate, the air temperature at the outlet side of the indoor heat exchanger (3) also changes, and this temperature change is detected by the temperature detector (16), and the outdoor unit (4) ability is controlled. In this way, the air adjusted to a substantially constant temperature is blown out from the air outlet (11) into the air-conditioned room (8) at an air volume that corresponds to the size of the indoor heat load, and flows inside each air-conditioned room (8). The conditioned air is sucked in [flows out from D (13) into the hallway, etc.
It returns to the indoor unit (1) from the ceiling suction port (14) via the suction duct (15).

In the case of the conventional example L, the capacity of the indoor fan (2) is controlled to keep the air blowing pressure in the main duct constant, and
The opening degree of the damper (10) is adjusted according to the heat load of the air-conditioned room (8), and the blowout air volume changes, and the blowout temperature is approximately controlled by controlling the capacity of the heat source device (4), which is an outdoor unit. Air conditioning is performed to maintain a constant temperature. Therefore, the air volume is increased in conditioned rooms with a high heat load, and the air volume is decreased in air conditioned rooms with a low heat load, and air conditioning is performed individually.

Another conventional example is the one described in Japanese Patent Publication No. 60-47497. In this method, a wind speed sensor is installed in the air volume control unit of each outlet, and the blower is controlled so that at least one of the dampers of each air volume control unit is fully open and all the air volume control units satisfy the air volume. The control method for the blower is different from the conventional example described above, but the air conditioning method is one in which the temperature of the air is kept constant and the volume of air blown into each air-conditioned room is adjusted individually. This is basically the same as the conventional example described above.

[Problem to be solved by the invention] Since the conventional duct type air conditioner with variable air volume is configured as described above, the air volume can be controlled according to the heat load of the air-conditioned room while keeping the air temperature constant. For example, if all the air-conditioned rooms are operating, the heat load will be maximum and the airflow will be the highest, but if only one room is operating, the heat load will be the minimum and the airflow will be the highest. becomes extremely small. Since the capacity of the heat source device is also controlled to keep the blowing temperature constant according to the change in air volume, a very wide capacity control range is required. In particular, when using a proportional type thermostat as an indoor setting device, that is, when the set room temperature approaches the room temperature, the blowout air volume is proportionally reduced to balance the heat load in the air-conditioned room. Compared to the design air volume set based on the maximum heat load of , the range of change in air volume is further widened because the air volume is throttled down for operation under light loads, and the range of required capacity control of the heat source equipment is similarly widened. However, there is a limit to the capacity control width of a heat source device.For example, in a heat pump type heat source device, when the capacity of a variable capacity compressor is controlled using an inverter,
Capacity control can only be performed to about 20% of the normal rated (maximum) capacity, and therefore the variable range of air volume is limited to 20%.If it is less than 20%, high pressure will increase during heating operation, and cooling During operation, the evaporation pressure decreases and the heat exchanger freezes, making continuous operation impossible in either case. Therefore, the variable air volume limits the range that can be individually air-conditioned, making it impossible to accommodate rooms with small heat loads. However, with recent air conditioning systems, for example, in tenant buildings etc., multiple outlets with small capacity are installed to accommodate future partition changes, and in residential buildings, rooms such as toilets and washrooms with small air conditioning areas and small heat loads are installed. As air conditioning is becoming more widespread, the minimum capacity of individual air conditioning is becoming smaller and smaller, and there is a problem that conventional variable air volume type duct type air conditioners cannot be used for such applications. Ta.

This invention was made to solve the above-mentioned problems, and it is a duct-type air conditioner that can individually air-condition even small rooms to be air-conditioned whose heat load is less than the capacity control limit of the heat source equipment. The purpose is to obtain.

[Means for Solving the Problems] The duct type air conditioner according to the present invention calculates the sum of target air volumes of each branch duct air volume control unit, and outputs an air volume insufficient signal when this sum is less than or equal to a predetermined value. The air volume detection means and each air conditioned room set the target air volume of the air volume control unit controller to the air conditioned room to the air volume according to the difference between the room temperature in the air conditioned room and the set temperature during air conditioning operation. An air volume setting device is provided which sets the air volume to zero at all times when the air conditioning is stopped, and to a predetermined minute air volume when the air conditioning is stopped and the total air volume detecting means is outputting an air volume insufficient signal.

[Function] In the duct type air conditioner according to the present invention, when the heat load in the air-conditioned room is low and the supplied air volume is small, this is detected by the total air volume detection means and an air volume insufficient signal is output, and the air volume insufficient signal is output. Depending on the output, the air volume setting device in the conditioned room when the air conditioning is stopped sets the target air volume to a minute air volume, increasing the total air volume supplied, and the excess heat generated due to insufficient capacity control of the heat source equipment causes the need for air conditioning. The air conditioning is distributed to the air-conditioned rooms where the air conditioning is not in operation, and air conditioning operation continues within the capacity control range of the heat source equipment.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a system configuration diagram showing an embodiment of this invention.
In the figure, (1) is an indoor unit with a built-in variable capacity blower (2) and an indoor heat exchanger (3), (4) is a variable capacity heat source unit, (5) is a refrigerant pipe, and (6) is a main unit. duct, (7) is branch duct, (8) is air-conditioned room, (9) is air volume control unit, 00 is damper, (11) is air outlet, (12)
1 is an indoor setting device, and 16 is an air temperature detector, which is the same as the conventional example shown in FIG. (18) is arranged in the air volume control unit (9) and is connected to the branch duct (7).
An airflow detector (19) detects the passing airflow of the room temperature Tr of the air-conditioned room (8), which constitutes a part of the indoor setting device (12).
The room temperature detector (20) is also an indoor setting device (
(12) is a room temperature setting device with an operation switch that sets the required room temperature Ts, (21) is also an indoor setting device (1).
2), an air volume setting device that calculates the air volume necessary for this air-conditioned room (8) from signals from the room temperature detector (19) and the room temperature setting device (20), and determines a target air volume; (22)
(23) is a heat source machine capacity control means for controlling the capacity of the heat source machine (4) according to the temperature signal from the air temperature detector (16), for example, by changing the frequency of the heat source machine inverter; The total sum of the target air volume set by the air volume setting device (21) of the air conditioner room (8) is calculated, and when the sum is less than a predetermined value, the air volume under-signal (24) is sent to each air volume setting device (21).
), the total air volume detection means (25) detects whether the air volume passing through each branch duct h (7) detected by the air volume detector (18) is equal to the target air volume set by the air volume setting device (21). (26) is an air volume control unit controller (26) that controls the damper (lO) so that
5) is a blower capacity control means that controls the amount of air blown by the variable capacity blower (2) in response to a signal from the variable capacity blower (2).

Next, its operation will be explained. First, the air-conditioned room (8)
When the air conditioning operation is started by operating the operation switch of the room temperature setting device (20) in A target air volume is set according to the heat load of the air-conditioned room (8). Details regarding setting of this target air volume will be described later. This setting 11 is manually input to the Hoju control unit control device (25), where the air flow detector (18
) is the amount of air passing through the branch duct detected by
The damper (10) is actively adjusted to match the 11 standard air volume set by the setting device (21). That is, when the 1-pass air volume is larger than the target air volume, the damper (10) is controlled to move in the closing direction, and conversely, when the 1-pass air volume is smaller than the 1141-air flow volume, the damper (10) is controlled to move in the open direction. If the air volume is insufficient even when the damper is fully open, the capacity of the variable capacity blower (2) is insufficient, so the damper (10) full open signal and The air volume matching signal is sent to the blower capacity control means (26), where at least one air volume control unit (26)
The high-power air volume of the variable capacity blower (2) is controlled so that the damper (10) of 9) is fully open and the sum of the air volumes passing through all the air volume control units i (9) matches the target air volume,
Appropriate air flow is always ensured. On the other hand, when the air flow rate changes, the temperature of the air blowing out changes, so this is the temperature detector (1
6), and based on the temperature detector, the heat source device capacity control means (22) controls the capacity of the heat source device (4) so that the temperature of the blown air is kept constant.

Next, the detailed operation of the total air volume detection means (23) will be explained with reference to FIG. Figure 2 shows the total air volume detection means (23)
In the flowchart showing the operation, first, when air conditioning control is started, in step (27), the [j standard wind velocity Qj of each air volume control unit h (9) set with each air volume setting device (21) is The total air volume QT of all the air volume control units (9) is calculated in step (28). Then, in step (29), it is determined whether the total air volume Q1 is smaller than a predetermined air flow JiQmin, and if it is determined to be smaller, in step (30), the air volume insufficiency (it) is set, and the process proceeds to step (33).

On the other hand, in step (29), the total air volume is determined as the predetermined air volume Q w
If it is determined that it is larger than in, the process proceeds to step (31), where it is determined whether this total wind M Q T is greater than or equal to the predetermined air volume Q1, and if it is determined that it is greater than or equal to the predetermined air volume, the process proceeds to step (
The low air volume signal is reset in step 32) and step 33
), and if it is determined that the total air volume Qt is less than or equal to the predetermined air volume 01, the process directly advances to step (33).

Then, in step (33), an insufficient air volume signal is output to each air volume setting device (21), and the operation of the total air volume detection means (23) is completed. Here, the predetermined wind JtQmin is set to the lower limit air volume that can keep the blowing air temperature constant within the capacity control range of the variable capacity heat source device (4), and if the air volume is higher than this, the heat source device (4) ) The capacity control means (22) allows the temperature of the blown air to be controlled to be constant. Further, the predetermined weight Q1 is set to a value larger than the lower limit air volume Qmin by an appropriate predetermined value. In this way, in the total air volume detection means (23), the sum of the target air volumes is the lower limit air volume Qmj
, n, an i-quantity insufficient signal is set, and when the total target air volume becomes equal to or greater than a predetermined air volume Q1, the air-volume insufficient signal is reset.

Next, details of the setting operation of the target scenery by the air volume setting device (21) will be explained with reference to FIG. FIG. 3 is a flowchart showing the operation of the air volume setting device (21). First,
When air conditioning control is started, it is determined in step (34) whether or not the operation switch of the room temperature setting device (20) is on. If the operation switch is on, the process proceeds to step (35), and the operation is performed from the room temperature detector (19). The current room temperature Tr of the air-conditioned room (8) and the set room temperature Ts from the room temperature setting device (20) are respectively read out, and in step (36) a deviation temperature, which is the temperature difference between them, is calculated, and in step (37) ), the target landscape for the calculated deviation temperature is set from the relationship shown in FIG.
) is output.

That is, Fig. 4 shows the relationship between the temperature deviation of the room 1iITr and the set room temperature Ts and the 11 standard airflow rate, where the solid line shows the relationship between the deviation temperature and the target airflow rate during heating, and the dashed-dotted line shows the relationship between the deviation temperature and the target airflow rate during cooling. As is clear from the figure, when the deviation temperature is large, the target air volume is set to a large constant value and the system is operated at maximum capacity, and as the deviation decreases, the target air volume decreases proportionally and the capacity also decreases. . If the deviation between the room temperature and the set room temperature is reversed, for example during heating, if the room temperature exceeds the set room temperature by a certain temperature or more, the target air volume is set to a certain small value and air conditioning operation continues at the minimum capacity.

On the other hand, if it is determined in step (34) that the air conditioning operation is stopped, the process proceeds to step (38), where the low capacity signal (24) from the total air volume detection means (23) is ON, that is, in the set state. It is determined whether the airflow is in the OFF state, that is, in the reset state, and if it is in the OFF state, that is, the air volume is not insufficient, the process proceeds to step (39), where the target air volume is set to zero, and the process proceeds to step (41). , the zero target air volume is output to the air volume control unit control device (25), and at step 9 (38), the air volume control unit (9) continues to be stopped while the air conditioning operation is stopped. ) is ON, that is, the air volume is determined to be too low, the process proceeds to step (40), where the target air volume is set to a micro air volume, and the process proceeds to step (41), where the target air volume of the micro air volume is set to the air volume control unit controller (25). is output, and the air volume control unit (9), which is currently not operating the air conditioner, is switched to operating the air conditioner with a small air volume.

As mentioned above, the air volume control unit (9
), the damper (10) is activated depending on the deviation between the room temperature and the set room temperature.
is opened and closed to control the amount of air blown into the air-conditioned room (8), and the amount of heat supplied and the air-conditioned room (8) are proportional to the amount of air blown out.
Stable operation is achieved at a point where the heat load is balanced, and the room temperature is controlled around the set room temperature.

In addition, when the air conditioning operation is stopped, the air volume control unit (9) has a damper (10
) is fully opened and the air-conditioned room (8) is not air-conditioned, but the sum of target air volumes of each air volume control unit (9) detected by the air volume sum detection means (23) is determined by the heat source equipment capacity control means ( 22), when the air volume falls below the minimum air volume that is the limit for capacity control of the heat source device (4), the air volume control unit (9) during air conditioning operation is set to a very small air volume, and the air flow from the air outlet (11) is A very small amount of wind is blown out. However, if this minute air volume is set to be sufficiently smaller than the maximum air volume, the fluctuations in room temperature will not become so large that there will be no practical problem at all.

In this way, when the total target air volume of the air volume control units falls below the predetermined minimum air volume, air is sent to the air volume control units whose air conditioning operation is stopped, so the total air volume increases, and the heat source equipment capacity control means (22) It becomes possible to escape from the capacity control limit. In addition, after the total target air velocity is small and the air volume control unit is switched to micro air volume operation while the air conditioning operation is stopped, the total air volume increases significantly when the air volume control unit is switched to air conditioning operation again. When the total air volume exceeds a predetermined air volume that is larger than the minimum air volume, the low air volume signal is reset.
The breeze operation to the air conditioner operation stop unit is canceled and normal operation can be resumed.

Next, the range of capacity control of the duct type air conditioner according to the present invention will be explained using a specific example in comparison with a conventional system. For example, the rated (maximum) capacity of the heat source device (4) is 1000
At 0Kcal/h, its capacity control range is 20% to 1
Assume that it is 00%. In the conventional system, the lower limit of capacity control with the air volume control unit I- is the lower limit of capacity control of the heat source equipment, which is 20%, that is, 10,000 Kcal/h.
X 0 , 2=2000 Kcal/h. However, since the air volume control unit performs capacity control by changing the air volume, if the range of change in the target air volume shown in Figure 4 of the air volume control unit is from 100% (design air volume) to 40%,
When the air volume of the air volume control unit is reduced to 40%, the capacity needs to be 2000 Kcal/h, which is the capacity control limit of the heat source equipment, and the capacity at the rated air volume is 2000 Kcal/h.
h10.4=5000Kcal/h. Therefore, only an air volume control unit with a capacity of 172 of the capacity of the heat source device can be connected.In contrast, in this invention, the air volume control unit that is stopped due to the low air volume signal is operated at a very small air volume. 17 of the capacity of the heat source machine
It is possible to connect up to 4 air volume control units. For example, the rated capacity of the air volume control unit is 2500Kcal/h.
Assume that four devices are connected. When the air volume is reduced to 40%, it is 2500Kcal/h x 0.4 = 1000K
cal/h, and if only one air volume control unit is operated, the minimum capacity of the heat source equipment is 2000Kc.
al/h, resulting in a surplus capacity of 1000 Kcal/h. However, if the target total air volume of the operating air volume control unit is small and falls below the air volume that is the capacity control limit of the heat source equipment, as in this case, an air volume insufficient signal will cause the stopped air volume control unit to operate at a very small air volume. Since the system operates to process surplus capacity, the total air volume increases and stable operation can be achieved. The surplus capacity that can be processed by the air volume control unit when air conditioning is stopped is 1000 Kcal/h/3 = 333 Kcal/h per unit, which is about 13% of the capacity of the air volume control unit, which is sufficiently small, so it can be used in rooms that do not require air conditioning. Problems such as temperature changes rarely occur.

In this way, it is possible to connect up to an air volume control unit whose capacity is sufficiently small for the capacity control range of the heat source device.

[Effects of the Invention] As described above, according to the present invention, the total air volume detection means calculates the sum of target air volumes of each branch duct air volume control unit, and outputs an air volume insufficient signal when this sum is equal to or less than a predetermined value. For each air-conditioned room, the target air volume of the air volume control unit controller for this air-conditioned room is set to the air volume according to the difference between the room temperature in this air-conditioned room and the set temperature when the air conditioning is in operation, and when the air conditioning is stopped. We have installed an air volume setting device that sets the air volume to zero at all times, and to a predetermined minute air volume when the air conditioning is stopped and the total air volume detection means is outputting a low air volume signal. This has the effect of providing a duct type air conditioner that can perform individual air conditioning even in air-conditioned rooms.

[Brief explanation of drawings]

Fig. 2 is a system configuration diagram showing an embodiment of the present invention, Fig. 2 is a flowchart showing the operation of the total air volume detection means of this embodiment, and Fig. 3 is a flowchart showing the operation of the air volume setting device of this embodiment. , FIG. 4 is a diagram showing the relationship between temperature deviation and target air volume, and FIG. 5 is a configuration diagram showing an air conditioner using a conventional variable air volume method. In the figure, (1) is an indoor unit, (2) is a variable capacity blower, (3) is an indoor heat exchanger, (4) is a heat source device, (5) is a refrigerant pipe, (6) is a main duct, ( 7) is a branch duct, (
8) is the air conditioned room, (9) is the air volume control unit, (16)
(19) is a room temperature detector, (20) is a room temperature setting device, (21) is an air volume setting device, (22) is a heat source device capacity control means, (23) is a total air volume detection means, ( 24) is an air volume insufficient signal, (25) is an air volume control unit control device, and (2G) is a blower capacity control means. The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A variable capacity heat source device, an indoor unit that has a built-in indoor heat exchanger connected to this heat source device via refrigerant piping, and a variable capacity blower that blows air heated or cooled by this heat exchanger; A main duct that communicates with the air outlet of the machine and branch ducts to the plurality of air-conditioned rooms, an air volume control unit that is installed in each of the branch ducts and adjusts the amount of air blown to the air-conditioned rooms, and adjustment of this air volume control unit. an air volume control unit control device that controls the air volume to a target air volume that corresponds to the room temperature in the air-conditioned room; a blower capacity control means that controls the capacity of the variable capacity blower according to the air volume that is blown to the air-conditioned room; and the indoor heat In a duct type air conditioner equipped with a heat source device capacity control means that controls the capacity of the variable capacity heat source device so as to keep the air blowing temperature on the exchanger outlet side substantially constant, the target air volume of each of the branch duct air volume control units is controlled. A total air volume detection means that calculates the total sum and outputs an air volume insufficient signal when this sum is less than a predetermined value, and a total air volume detection means that calculates the target air volume of the air volume control unit controller for each air conditioned room, During operation, the air volume is adjusted to the difference between the room temperature in the air-conditioned room and the set temperature, when the air conditioning is stopped the air volume is always zero, and when the air conditioning is stopped and the total air volume detecting means is outputting an air volume insufficient signal, the air volume is set to a predetermined minute amount. A duct type air conditioner characterized by being equipped with an air volume setting device for setting the air volume.