JPH023104B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of operating an air conditioner, and more particularly to a control method for adjusting the capacity of an air conditioner depending on the amount of heat load in a room.

Technical Background of the Invention Now, a fixed air volume type air conditioning system is represented by a system diagram as illustrated in FIG.

In other words, the air is exhausted from the living room 10 by the return fan 20, part of it is released to the outside air by the outside air dampers 21 and 22, and the rest is mixed with outside air taken in from the outside air intake damper 23. In this method, cooling and heating are carried out by a hot/cold water coil 40 whose flow rate is controlled by 41 and 42, and air is supplied to the living room 10 by a blower 50, and the load in the living room is handled by the difference in calorific value between the exhaust air and the supplied air. . Further, when the humidity is insufficient, the spray 52 is controlled by the humidifying valve 51 to perform humidification.

These controls are performed by the air conditioner control device 60 mainly by proportional control of the room temperature setting difference. A part of the control device 60 is mechanically controlled by central monitoring, and its functional block diagram is shown in FIG. 2 and will be explained.

First, the outside air cooling determination unit 61 determines whether or not cooling with outside air is possible from the outside air temperature sensor 31, outside air humidity sensor 32, living room temperature sensor 11, and living room humidity sensor 12, and the outside air intake damper control unit 64
Make a permission signal. On the other hand, the outside air temperature is taken in from the outside air temperature sensor 31, and the living room temperature set value is passed from the outside air compensation control section 62 to the room temperature deviation proportional control mechanism 63, and the proportional control output based on the difference with the temperature sensor 11 of the living room 10 is applied to the outside air intake damper. This is performed for the control section 64 and the cold/hot water valve control section 65. The outside air intake damper control unit 64 and the cold/hot water valve control unit 65 perform operations such as reversing the opening/closing direction of the output and operate the outside air intake dampers 21, 22, 23 and the cold/hot water valves 41, 42 according to the air conditioning load. Controls the opening of dampers and valves. On the other hand, the humidifying valve control section 66 also controls the humidifying valve 51 based on the humidity from the humidity sensor 12 in the living room.

Problems with the Background Art Although the air conditioner 30 is controlled in this manner, when considering the selection of air conditioning equipment and energy consumption in the building, this air supply and exhaust system is operated throughout the year. It is a power facility, and it is a facility that accounts for a considerable amount of energy consumption in a building. Furthermore, the selection of the air blowing capacity of the blowers (air supply fan 50 and air return fan 20) is made based on the peak load, so when considering the entire year, a large amount of conveying power is operated for the peak load of only a few percent. It turns out.

Possible means for reducing this power include intermittent operation of the blower and operation with a reduced blowing capacity by controlling the rotational speed of the blower.

Among these methods, the method of intermittent operation has already been implemented, and this method determines the difference from the set temperature at regular time intervals from the room temperature sensor 11 shown in the block of Fig. 2, and determines the difference between the starting and stopping times. This is a method in which the controller 67 calculates and controls the air supply fan 50 and air return fan 20.

By the way, considering the performance characteristics of the blower, the amount of air blown is proportional to the number of rotations, and the shaft power is proportional to the cube of the number of rotations, so it is better to control the number of rotations than to use intermittent operation to reduce power energy. The effect is great,
In addition, as the wind speed decreases, noise also decreases, making it even more effective.

OBJECTS OF THE INVENTION An object of the present invention is to provide a control method for converting the above-mentioned excess capacity of a blower into a proper capacity by controlling the rotational speed.

Summary of the Invention The present invention is a method for adjusting the air volume of an air supply fan and a return fan by controlling the rotation speed of each drive mechanism in a fixed air volume air conditioner having water system proportional control based on room temperature and settings. An air volume adjustment mechanism (air conditioning function power determination unit, fan air volume control unit) is added, and the valve opening degree of water volume is integrated over a certain period of time, and the maximum air blowing capacity Q _MAX and minimum air blowing capacity Q _MIN of the fan are calculated as the throttling rate ( 100, 0%)
The average valve opening degree β% is regarded as the throttling rate of the water amount L, and α×
This is a method in which β is the aperture rate of the overall capacity of the device, and the new air volume is determined so that this device aperture rate becomes constant.If necessary, the drive mechanism is operated intermittently as the air volume conversion decreases. be.

Embodiment of the Invention The configuration of an embodiment of the present invention is shown in FIG. This corresponds to the functional block diagram in FIG. 2 of the control device 60 in FIG. 1, and the configuration in which the present invention differs from the conventional one is as follows.

B. The output of the outside air compensation control section 62 is output to a newly provided air conditioning function power determination section 68, and fine adjustment of the outside air compensation is controlled by the fan air volume. That is, the rotational speeds of the air supply fan 50 and the air return fan 20 are controlled via the fan air volume control section 69.

○B The start/stop control unit 67 is the air conditioning function power determination unit 68
The air volume set in is determined and processed by the fan air volume control unit 69 for subsequent control (intermittent control).

(c) If the required air volume is smaller than the air volume variable range, the fan air volume control unit 69 outputs an output to the fan start/stop control mechanism 67.

○D Since the outside air intake amount changes depending on the airflow rate, in order to compensate for the absolute amount of outside air intake, the damper opening degree that takes into account the airflow amount is output to the outside air intake damper control section 64.

Now, the operation of the present invention will be explained with reference to FIG.

First, in the air conditioning functional power determination unit 68, the heat exchange amount of the air conditioning coil (cold/hot water coil 40) is determined as the water supply amount,
Wind supply amount, water inlet enthalpy (Kcal/Kg),
It is determined by the enthalpy of the air inlet (Kcal/KgDA), and approximately (water volume reduction ratio) x (air volume reduction ratio) = constant for minute changes in water volume and air volume.
...It can be regarded as (1 formula).

Therefore, assuming that the water system is controlled proportionally using the conventional method of controlling the setting difference from room temperature,
The value obtained by multiplying the water volume throttling rate obtained from the opening degrees of the valves 41 and 42 by the throttling rate of the air volume at that time can be regarded as the throttling rate for the equipment capacity, and by increasing the water volume, Air volume can be reduced.

However, since the valve opening degree constantly changes, the integral value for a certain period of time is calculated and the cold and hot water valves 41, 42 are
The most desirable opening control response is
50 to 80%) is the operating point that takes into account the equipment capacity.

Therefore, the air volume control during the valve opening degree integration at this time continues on a zero-order hold, that is, at a constant air volume. Thereby, it is possible to grasp the load fluctuation in the room by integrating the valve opening degree which is proportionally controlled based on the difference in set room temperature.

Note that the set room temperature compensated for outside air to obtain the room temperature setting difference may be outputted to the air conditioning function power determination section 68 instead of being outputted from the outside air compensation control section 62 to the room temperature deviation proportional control mechanism 63 as in the conventional case. outside air compensation control is possible.

The fan air volume control unit 69 determines whether or not the specified air volume can be output (if the air volume is lowered, the air cannot be blown below a certain level due to duct resistance), and if possible, the air return fan 20 and the air supply fan 20 The rotation speed corresponding to the designated air volume is determined from a rotation speed-air volume correlation table created in advance, and a set output is output.

On the other hand, in general, other exhaust fans of the air conditioner 25
Therefore, if the outside air volume is not maintained at a constant value, the air volume will be unbalanced and the heat load due to drafts will increase. Therefore, it is necessary to secure an air volume equivalent to this outside air volume. ~
23 and calculates the opening degree of the outside air intake damper control unit 6.
4 to ensure the absolute intake of outside air. FIG. 4 is an explanatory diagram of a method for determining the new air volume so that the device aperture ratio is constant according to the present invention.

As shown in Figure 4, the maximum blowing capacity of the fan
Q _MAX and the minimum air blowing capacity Q _MIN are considered as the throttling rate of the air flow rate (100, 0%). The air throttling rate α% and the average valve opening β% are regarded as the throttling rate of the water volume L, and α×β is the capacity of the entire device. The aperture ratio is set to .

A disturbance occurs at the ideal point A (α1, β2) of a certain balance point, for example, the load in the living room increases, the proportionally controlled water amount (valve opening degree) β increases from (β1 → β2), and the point B (α1, β2) increases. β2), the transition itself is not an issue.

However, if the valve opening degree β2 at point B is close to the upper limit or is at a point where the control system is poor, control is performed to bring the ventilation throttling rate (air volume) β close to the ideal point β1. .

That is, point B (α1, β2) is moved to the balance point D point (α2, β3), and control is performed under the condition that α·β=constant.

in this case, α1・β2=α2・β3=α1・β2/β1・β3 and β1=β3 So that the condition holds, that is, α2=α1β2/β1 And it is sufficient.

Therefore, the calculation assumes that this load increase is covered by an increase in air volume, and the new air volume is calculated using α2=(α1・β2)·β1, and air is blown at α2.

As a result, heat supply to the living room is promoted, the valve opening decreases to (β2→β3), and converges to the next balance point (β3, β2) where the air volume increases.

In this way, the new air volume is determined so that the device aperture rate remains constant.

In addition, theoretically, in a minute interval Air volume Δα∝ Heat amount ΔQ However, the conversion efficiency of the heat exchanger is not necessarily Air volume Δα ∝ Heat amount ΔQ ∝ Valve opening Δβ Therefore, in general, α2=α1β2/β1 When the air volume is β3＞α1 becomes.

The goal of the control in the present invention is to bring the valve opening close to the valve opening β1 with good control, so the air volume α2 is changed so that the valve opening β3=valve opening β1.

This change in air volume is sufficient.

In conclusion, we can say the following.

The present invention provides the ideal excuse level A point before the occurrence of disturbance;
When comparing the balance point D point after dealing with the disturbance, α and β≠ are constant.

However, in the present invention, from point A, which is an ideal point, to point B, which is a balance point corresponding to disturbance, to point C, which is a transient state point,
This is a control means that determines the air flow rate α2 under a constant condition of α and β so as to bring the air flow rate to point D, which is a desired balance point in a disturbance state, via the above point.

A curve C2 with constant α and β passing through points B and D is
It is natural that it is larger than the curve C1 with constant α and β at point A before the load increase, and the curve C3 with constant α and β at point C is considered as a transient state. greater than the constant curve C2.

If the air volume is below the lower limit and output is not possible, reduce the air volume to the minimum and then reduce the air volume reduction by the following (2)
A signal to stop the fan for the intermittent operation time calculated by the formula) is output to the start/stop control section 67 to perform intermittent operation.

Intermittent stop time = (minimum air volume - required air volume) / (minimum air volume) × control period ... (2 equations) Effects of the Invention Thus, according to the present invention, in a fixed air volume air system, the valve can be closed while the device throttling rate remains constant. By converting the air volume so that the air flow rate becomes the set throttling ratio, the air volume of the blower and return fan is controlled by the fan rotation speed, and the valve opening is brought to a value close to the valve opening that provides good controllability. This allows for reduction of conveyance power,
In addition, by reducing the wind speed, duct resistance is reduced, thermal efficiency around the hot and cold water coils is increased, and noise can be expected to be reduced.

Furthermore, since drastic changes in the amount of air blown into the living room due to intermittent operation can be suppressed, discomfort caused by cold drift, etc. can also be reduced.

[Brief explanation of drawings]

Fig. 1 is a system diagram around the air conditioner, Fig. 2 is a conventional control function block diagram, Fig. 3 is a block diagram of an embodiment of the present invention, and Fig. 4 is a system diagram in which the device aperture rate is constant in the present invention. FIG. 10... Room, 11... Room temperature sensor, 12...
... Room humidity sensor, 20 ... Air return fan, 25 ... Exhaust fan, 50 ... Air supply fan, 21, 22, 23 ... Outside air intake damper, 30 ... Air conditioner, 31 ... Outside air temperature sensor, 32 ...Outside air humidity sensor, 4
0...Cold/hot water coil, 41...Cold water control valve, 42
... Hot water control valve, 60 ... Air conditioner control device, 61
...Outside air cooling determination section, 62...Outside air compensation control section,
63...Room temperature deviation proportional control mechanism, 64...Outside air intake damper control unit, 65...Cold/hot water valve control unit, 6
6... Humidification valve control section, 67... Start/stop control section,
68... Air conditioning function power determination section, 69... Fan air volume control section.

Claims (1)

[Claims] 1. In a fixed air volume air conditioner that has proportional control of the water system based on room temperature and settings, an air volume adjustment mechanism is added, and the valve opening degree of the water volume is integrated for a certain period of time while maintaining a constant air volume. The maximum air blowing capacity Q _MAX and the minimum air blowing capacity Q _MIN are regarded as the throttling rate of the air blowing volume (100, 0%).The throttling rate α% of the air blowing volume and the average valve opening degree β% are regarded as the throttling ratio of the water volume L.α× β
As the throttling rate of the overall capacity of the equipment, by converting the air volume to the air volume such that the valve opening becomes the set throttling ratio while keeping this equipment throttling ratio constant, the air volume of the air supply fan and air return fan can be adjusted respectively. An air volume control method for an air conditioner, characterized in that the rotation of the drive mechanism of the air conditioner is controlled to bring the valve opening close to a valve opening with good controllability. 2. The air volume control method for an air conditioner according to claim 1, wherein the drive mechanism is operated intermittently as the air volume conversion decreases.