JP2536234B2 - Air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air conditioner having a main duct and a branch duct that employs a variable air volume control system capable of independently adjusting the room temperature of each room.

[Conventional technology]

2. Description of the Related Art As an air conditioner that employs a conventional variable air volume control system that controls the air volume of a blower, there is an air conditioner that distributes cold air or hot air to each room via a duct. However, the branch ducts branched into each room usually have different lengths from the branch point to each room, and the branch ducts have different blow resistances. Further, the blow resistance of each duct is also affected by a defect in the duct installation work, for example, a deformation of the duct cross-sectional shape due to distortion or the like, or the inclusion of foreign matter in the duct.

In such a state, in particular, in the latter case, if the drive of the blower is controlled by detecting the pressure of the common blower air duct portion, that is, the root portion of the main duct, the difference in the pressure loss on the downstream side is ignored. As a result, it is impossible to control the air flow in each room with high accuracy, and thus to control the room temperature.

In the conventional example shown below, the pressure at the root of the main duct before being blown into each room is detected to control the drive of the blower.

As a concrete example that represents these conventional examples, refer to Chapter 2 of the Refrigeration and Air Conditioning Handbook published by the Japan Refrigeration Association (new edition, 4th edition, application), page 41 of the air conditioning system.
The example of (a) is selected and its operation will be described below.

FIG. 6 is a configuration diagram showing a conventional air conditioner described in the Refrigeration and Air Conditioning Handbook.

In the figure, 1 is an air-conditioned room to be air-conditioned,
In this figure, the case of four rooms is shown. 2 is a centralized air-blowing means that is an indoor unit that is disposed in the ceiling of the air-conditioned room 1 or the like and functions as a blast source of cold air or warm air. 3 is an air filter that removes dust in the air and purifies the air. Reference numeral 4 is a heat exchanger for cooling or heating air, and 5 is a blower for blowing cold air or warm air. The indoor unit 2 is composed of an air filter 3, a heat exchanger 4, and a blower 5. 6 is a main duct communicating with the air outlet of the indoor unit 2, 7 is a branch duct branched from the main duct 6 according to the number of each air-conditioned room 1, and 8 is each air-conditioner installed in each branch duct 7 part. A throttle type air blow adjusting unit for adjusting the amount of air blown into the chamber 1, a damper 9 rotatably mounted in the throttle type air blow adjusting unit 8, and a blower outlet 10 located at the end of the branch duct 7. , 11 is a suction port arranged below the door of the air-conditioned room 1, 12 is a ceiling suction port arranged on the ceiling surface of the corridor outside the air-conditioned room 1, and 13 is a ceiling suction port 12. It is a suction duct that communicates with the suction port of the indoor unit 2. 14 is a room thermostat for setting and detecting room temperature installed in each air-conditioned room 1,
Reference numeral 15 is a temperature detector that detects the temperature of air blown from the blower 5 in the main duct 6, 16 is a pressure detector that also detects air pressure from the blower 5 in the main duct 6, and 17 is a heat exchanger 4
Is a heat source device such as a heat pump that is connected to the heat exchanger 4 and controls the heat conversion operation in the heat exchanger 4.

The conventional duct-type air conditioner for centralized heating and cooling is configured as described above, and the air cooled or heated by the heat exchanger 4 is used as cool air or warm air by the blower 5 and the main duct 6 and / or the branch duct 7 are used. A centralized blower 2 for distributing and blowing air into each of the plurality of air-conditioned rooms 1 via the air-conditioner, and a damper 9 mounted on each of the branch ducts 7 for supplying cold air or warm air to the air-conditioned room 1. It has a diaphragm type air blow adjusting unit 8 which is an air blow adjusting means for adjusting by opening and closing.

Next, the operation of the conventional air conditioner having the above configuration will be described.

First, according to the temperature difference between the set temperature set by the user or the like in each room thermostat 14 and the detected actual room temperature, the opening degree of the damper 9 of the throttle type air flow adjusting unit 8 is set to an arbitrary position. Adjust. The pressure in the main duct 6 also changes according to the opening degree of the damper 9. This change in pressure is detected by the pressure detector 16, and the blower capacity by the blower 5 is adjusted so that the preset pressure is obtained. Further, since the temperature of the air blown on the outlet side of the heat exchanger 4 also changes with the change in the amount of air blow, the temperature detector 15 detects this change and controls the capacity of the heat source unit 17 so that the air temperature reaches a preset air flow temperature. To do.

By such a series of control, an appropriate amount and temperature of air, which is adjusted to a substantially constant temperature, is blown into the air-conditioned room 1 from the air outlet 10. That is, the air volume is blown out according to the magnitude of the heat load in each air-conditioned room 1. Further, the air conditioned in the air-conditioned room 1 flows into the ceiling suction port 12 from the suction outlet 11 through a space such as a corridor, and returns to the indoor unit 2 again via the suction duct 13. Then, the same flow is repeated again according to the above operation.

As described above, in the duct type air conditioner for centralized cooling and heating using the conventional general throttle type air blow adjusting unit 8, the air blow temperature and the air blow according to the fluctuation of the heat load in each air-conditioned room 1. The optimum values for the pressure are determined, and the capacities of the heat source unit 17 and the blower 5 are controlled so that these values are substantially constant.

A device that does not use the pressure change in the main duct 6 as a control index is disclosed in Japanese Patent Publication No. 60-47497. In this, the terminal air volume control unit at each outlet has a function as a wind speed sensor to control the blower 5 and the like. Further, in this device, when the damper 9 is fully opened and the blower adjusting unit having the most inferior blower condition outputs an output of the set airflow or less, the blower 5 increases the airflow of the blower 5 based on this output. , The blower 5 is always controlled to the minimum required capacity.

[Problems to be Solved by the Invention]

In the conventional air conditioner as described above, in order to make the root pressure of the main duct 6 constant, in controlling the air blowing capacity of the blower 5 using the root pressure as a control index, the air blowing resistance of each branch duct is different. Therefore, the amount of air passing through each branch duct, that is, the amount of air supplied to each air-conditioned room 1 cannot be properly controlled.

Further, in the case where there is a blower obstruction in the branch duct due to a defect in the duct installation work, such as deformation due to distortion of the duct cross-sectional shape, or the inclusion of foreign matter in the duct, supply to each of the above-mentioned air-conditioned rooms 1 It was especially difficult to maintain the proper air volume.

In addition, in the device as disclosed in Japanese Patent Publication No. 60-47497, although it is possible to obtain the proper air volume by measuring the air velocity at the air outlet in each room, the wind velocity of each terminal Since a sensor is required, it is a large-scale facility and extremely expensive. Usually, there are about 5 to 15 terminals of this type of air conditioner, and the high and low prices are extremely important.

The present invention has been made to solve the above problems, and an air conditioner capable of appropriately controlling the capacity of a blower and appropriately controlling the amount of ventilation to each air-conditioned room by a simple configuration and means. The purpose is to provide a device.

[Means for solving the problem]

Therefore, the air conditioner according to the present invention has a blower and a heat exchanger, and blows the air that has exchanged heat with the heat exchanger to a plurality of air-conditioned rooms via a main duct and a branch duct connected to the blower. Centralized air blowing means, air blowing adjusting means mounted on each of the branch ducts to adjust the air blowing amount of cold air or warm air to the air-conditioned room by opening and closing a damper, and a damper for controlling the opening and closing of the damper of the air blowing adjusting means. Control means, blower control means for setting the power supplied to the blower to a predetermined frequency, air volume measuring means for measuring the actual air flow rate by detecting the air flow rate from the blower with an air flow rate detector, and the blower By the outputs of the control means, the air volume measuring means, and the damper control means, the ventilation loss characteristics of each branch duct are obtained from the air volume and the air pressure difference at the set frequency of the air blower when the air adjustment means are fully opened. , The maximum value of the blast pressure difference required for each blast adjusting means during the air-conditioning operation based on the ventilation loss characteristic and the ventilation loss characteristic of the damper with respect to the known opening / closing degree of the damper, and the blast pressure difference At the maximum value, each air blow adjusting means controls the damper control means to the degree of opening and closing of each damper to obtain the required air volume, and controls the blower control means to the frequency at which the air blow pressure difference has the maximum value with respect to the sum of the air volume required by the air blow adjusting means. The above-described object is achieved by a configuration characterized by including an arithmetic processing means for performing the above.

[Work]

The air conditioner according to the present invention has the above configuration.
First, the damper control means performs control to fully open one of the dampers of the air flow adjusting means and fully close the other.

Then, the blower control means inputs electric power of a preset predetermined frequency to the blower. further,
The air flow rate of the blower at this time is detected by the air flow rate detector and measured by the air flow rate measuring means. Then, the calculation processing means from the damper opening / closing information by the damper control means, the operation frequency information of the blower by the blower control means, the measured value of the air flow rate by the air volume measuring means, and the ventilation loss characteristic information for the known opening / closing angle of the damper, These relationships are calculated and tabulated or formulated.

This series of operations is performed by the number of blower adjusting means, and in order to blow a predetermined air volume to each branch duct, information on how to control the operating frequency of the blower and the opening / closing degree of the damper of the blower adjusting means is accumulated. .

Then, during the actual air conditioning operation, the arithmetic processing means controls the operating frequency of the blower and the opening / closing degree of the damper of the blower adjusting means on the basis of the above-mentioned accumulated information to control the operation of the blower to a necessary and sufficient capacity. In addition, an appropriate amount of cold air or warm air is appropriately supplied to each air-conditioned room according to the set air volume.

〔Example〕

The air conditioner according to the present invention will be described below with reference to embodiments.

FIG. 1 is a configuration diagram showing an air volume control system of an air conditioner according to an embodiment of the present invention. In the figure, the parts indicated by reference numerals 2, 4 to 9 and 14 are the same as or correspond to the constituent parts of the above-mentioned conventional example, and the duplicated description will be omitted.

In this air conditioner, as in the conventional example, the air cooled or heated by the heat exchanger 4 connected to the heat source unit (not shown) is blown by the blower 5 as cold air or hot air through the main duct 6 and the branch duct 7. Centralized air-blowing means 2 for blowing air into each of the plurality of air-conditioned rooms 1, and the branch ducts 7 installed to adjust the amount of cold air or warm air to the air-conditioned rooms 1 by opening and closing a damper 9. It has a blower adjusting means 8. Also,
Each air-conditioned room 1 is provided with a room thermostat 14 for setting and detecting room temperature, and is connected to the arithmetic processing means 23. In addition, the normal air conditioning operation of this air conditioner conforms to the conventionally known operation, and the temperature / heat generation amount control of the heat source unit (not shown) also conforms to the conventional example, so description thereof is omitted. The air volume control, which is a feature of the invention, will be described below.

First, the test operation mode of this air conditioner will be described.

In FIG. 1, reference numeral 19 denotes an air flow detector arranged at the base of the main duct 6 for detecting the air flow from the concentrated air blowing means 2. Reference numeral 20 is a damper control means for controlling the opening degree of the damper 9 of each air flow adjusting means 8. A drive mechanism (not shown) that individually opens and closes each damper 9 is connected to the damper 9, and each drive mechanism is operated in response to an opening signal from the damper control means 20 to respond to it. The opening degree of the damper 9 is controlled. Reference numeral 21 is an air volume measuring means for measuring the actual air volume based on the detection signal of the air volume detector 19. Reference numeral 22 is a blower control means for setting the power supplied to the blower to a predetermined frequency. 23 is the blower control means 22 and the air volume measuring means 21
The output of the damper control means 20 and the known information of the ventilation loss characteristics depending on the opening degree of the damper are used to calculate the relationship between the air flow rate of the blower adjusting means 8, the opening / closing degree of the damper 9, and the power supply frequency of the blower 5 to control the damper. It is an arithmetic processing means for controlling the means 20 and the blower control means 22. The arithmetic processing means 23 includes a measured air volume output from the air volume measuring means 21, an output of the blower operating frequency from the blower control means 22, an output of the damper opening / closing degree information from the damper control means 20, a known damper opening degree and its ventilation. By inputting the loss characteristic information, these relations are arithmetically evaluated and tabulated or formulated to calculate the ventilation resistance in each duct.

Next, an example of the function and operation of the arithmetic processing means 23 of the air conditioner configured as described above will be described with reference to FIG. FIG. 2 is a blast characteristic diagram showing the relationship between the operating frequency, the air volume, and the pressure of the blower 5 used in the air conditioner of one embodiment of the present invention.

In FIG. 2, the vertical axis is the static pressure P by the blower 5, the horizontal axis is the air volume Q, the solid line is the characteristic curve of the blower 5, and the broken line is the resistance curve showing the blow resistance of the branch duct 7 or the like reaching the predetermined damper 9. . The parameter of the characteristic curve shown by the solid line is the operating frequency R of the blower 5. Note that Q for the normal parameter R
The -P relationship is known.

That is, assuming that one damper 9 is fully opened, all the other dampers are fully closed, and the operating frequency of the blower 5 at this time is R1, the actual blow rate is Q1.
The pressure loss (that is, the blast pressure difference) P1 is obtained from the above known Q-P-R relationship. Generally, the blowing pressure difference P and the air volume Q have the following relationship.

P = C × Q ² Here, C: loss coefficient Therefore, if the blast pressure difference P1 at which the blast volume becomes Q1 when the operating frequency of the blower 5 is R1, the unknown coefficient C is determined. The blast resistance curve (broken line) of the branch duct of the system of the damper 9 is known, and the loss coefficient C (damper fully open) of the branch duct itself can be obtained.

Further, as shown in the characteristic diagram of the damper opening / closing angle and the ventilation loss coefficient in FIG. 3, the damper 9 is
The ventilation loss coefficient C _D changes. The relationship between the opening / closing angle Di and the ventilation loss coefficient C _D can be known in advance in the following functional form for the damper 9 to be used.

C _D = F [Di] The ventilation resistance due to the opening / closing degree of the damper 9 and the ventilation resistance of the branch duct are considered to be series resistance. Therefore, the total ventilation resistance of the branch duct including the change in the opening of the damper 9
C _T can be given as the sum of both (C _T = C + C _D ). From the above, the relationship between the blower pressure difference P, the air flow Qi, and the damper opening Di in the blower system of the branch duct is determined as follows.

P = (C + F [Di]) Qi ² Then, the operating frequency R corresponding to P and Qi can be obtained from the description of FIG.

By performing the same operation as described above on the damper 9 of the other blower adjusting means 8, the relation between the blower operating frequency R, the air volume Qi, and the damper opening Di can be tabulated or formulated for each blower system. Become. And by using the result of this table or formulation,
If the amount of air passing through each blower adjusting means 8 is set in advance, the damper opening Di of each blower adjusting means 8 when the blower operating frequency R of the centralized blower means 2 is determined can be calculated and made into a table or a mathematical expression.

Therefore, the arithmetic processing means for executing the arithmetic processing as described above and controlling the damper control means 20 and the blower control means 22.
By configuring the air conditioner using 23, the highly accurate air blowing control for each air-conditioned room 1, which has been conventionally required, is input to the blower 5 of the centralized air blowing means 2 and the air blowing adjusting means 8 is provided. This is possible by controlling the opening of the damper 9.

Further, it is not necessary to provide each air-conditioned room with a conventional air volume detection sensor function using an expensive air velocity sensor as disclosed in Japanese Patent Publication No. 60-47497.

 Next, the operation of the air conditioner of this embodiment will be described.

FIG. 4 is a flow chart showing an example of control operation at the time of test operation of the air conditioner of one embodiment of the present invention. It should be noted that this control operation is carried out by utilizing the function of the microcomputer provided in the arithmetic processing unit 23.

This control operation during the trial run is performed during the trial run of the air conditioner, when changing the equipment or equipment, and during regular inspections, as well as fluctuations in the ventilation load of the air-conditioned room that require the maximum ventilation, and other necessary operations. It is desirable to carry out when the change of the maximum blowing pressure occurs.

First, in step S1 in FIG. 4, it is determined whether the operation mode is the trial operation mode. When not in the trial run mode, the series of control operations described below are not performed. In the trial operation mode, the operation of the heat source unit (not shown) is stopped in step S2, and the operation of the blower 5 is started in step S3. Then, in step S4, the number N of the dampers 9 of the blower adjusting means 8 connected to the branch duct 7 is set, and in step S5, the first (I = 1) damper 9 is set to full open, and the remaining dampers 9 are set. Fully closed. The opening / closing control of the damper 9 is performed by the damper control means 20. In step S6, the blower control means 22 controls the operating frequency of the blower 5 to a predetermined value.

In step S7, the air flow rate at that time is measured by the air flow rate measuring means 21. Then, in step S8, the opening degree of the damper 9 and its ventilation loss characteristic information are read into the arithmetic processing means 23.

In step S9, it is determined whether or not the damper 9 that has performed the above procedure is the Nth damper 9. If it is not N-th, I = I + 1 is set in step S10, and the process returns to step S5 to repeat the above operation. Therefore, the above operation is I = 1
All of the dampers 9 to I = N are sequentially performed, and a total of N times are repeated. Then, when it is confirmed in step S9 that the I = Nth damper 9 is obtained, in step S11, the opening of each damper 9, the drive frequency of the blower 5, and the blown air amount obtained in the above series of operations are set. These relationships are calculated from the data, and a table or formulation is created for each blower adjusting means 8. This arithmetic operation is performed by the arithmetic processing means 23.

Next, each of the dampers 9 formed into the above table or formulated
An example of control operation at the time of actual operation of the damper 9 and the blower 5, which is performed by using the relationship among the opening degree, the drive frequency of the blower 5, and the blow rate, will be described.

FIG. 5 is a flow chart showing an example of control operation during air conditioning operation of the air conditioning apparatus of one embodiment of the present invention.

First, in step S21, for each air blow adjusting means 8, the air volume, the damper opening, the drive frequency R of the blower 5 and the known R which are formulated or tabulated for each air blow adjusting means 8 by the arithmetic processing means 23 described above. And QP, when the air volume in each air blow adjusting means 8 is set as the set air volume,
Calculate the pressure loss Pi when the damper opening is fully opened. Next, in step S22, the maximum value Pimax of the pressure loss Pi of each air flow adjusting means 8 is selected. In step S23, the damper opening degrees that give the respective set air volumes when the pressure loss Pi is Pimax for each of the air flow adjusting means 8 are obtained from the above relationship. At this time, the opening degree of the damper 9 of the air flow adjusting means 8 whose pressure loss Pi was Pimax in step S21 is naturally in the fully open state. Then, in step S24, the damper opening degree obtained in step S23 is instructed to each blower adjusting means 8 via the damper control means 20, and the damper 9 is operated. Then, in step S25, the power supply frequency R that gives the maximum value Pimax of the pressure loss to the sum ΣQ of the required air volumes of the respective air blow adjusting means 8 is set, and the blower control means 22 sets the centralized air blow based on this set value. The drive of the blower 5 of the means 2 is controlled.

By performing such control operation, it is possible to more easily realize the operation control for minimizing the blowing power as disclosed in Japanese Patent Publication No. 60-47497.

As described above, in this embodiment, when in the test operation mode, the damper control means 20 sets the damper 9 of the blower adjusting means 8 to one.
Control to fully open the platform and close the others.

Next, the blower control means 22 controls the blower control means 22 so that the predetermined frequency is set in advance. Further, the amount of air blown by the centralized air blower 2 at this time is detected by the air flow detector 19 and measured by the air flow measuring means 21. Then, the opening / closing information of the damper 9 by the damper control means 20, the frequency information of the blower 5 by the blower control means 22, the measured value of the air flow rate by the air volume measuring means 21, and the ventilation loss characteristic information for the known opening / closing angle of the damper 9. From this, the arithmetic processing means 23 calculates these relations to form a table or a formulation. This series of operations is performed by the number of the air blow adjusting means 8, and how to control the frequency of the blower 5 and the opening / closing degree of the damper 9 of the air blow adjusting means 8 in order to blow a predetermined air volume to each branch duct 7. Accumulate information.

As described above, the air passage resistance of each branch duct 7 is detected in advance, and the air volume of each air blow adjusting means 8 is indirectly estimated,
An appropriate opening / closing degree of the damper 9 and an operating frequency of the blower 5 with respect to the set air volume are obtained.

Then, during the actual air conditioning operation, by controlling the operating frequency of the blower 5 and the opening / closing degree of the damper of the blower adjusting means 8 based on the above information, each air-conditioned room 1
It is possible to stably supply an appropriate amount of cold air or warm air.

Therefore, in this embodiment, it is possible to extremely easily distribute an appropriate air volume and reduce the air blowing power according to the air blowing resistance of each duct, and it is possible to appropriately maintain the air volume supplied to each air-conditioned room 1. Moreover, these controls can be achieved with a simple configuration without using a special terminal air volume control unit having a wind speed sensor function for each air-conditioned room. As a result,
With an inexpensive structure, an efficient air conditioning effect can be realized.

〔The invention's effect〕

As described above, the air conditioning apparatus according to the present invention, during the test operation, the opening / closing information of the damper by the damper control means, the control information of the blower by the blower control means, the air volume information by the air volume measuring means, and the known damper. The calculation processing means calculates each of these relations from the opening degree and the ventilation loss characteristic information, and forms a table or a formula to detect the air passage resistance of each duct in advance, and the air volume to each air-conditioned room. Can be indirectly estimated to determine the appropriate opening and closing degree of the damper and the operating frequency of the blower drive power source with respect to the set air volume. And in the actual air conditioning operation,
Based on the above information, by controlling the power supply frequency of the blower and the opening / closing degree of the damper of the blower adjusting means by the arithmetic processing means, it is possible to reduce the blower power and to reduce the supply air volume to each air-conditioned room. Can be maintained properly. Moreover, since these controls can be achieved with a simple structure without providing a special terminal air volume measuring unit equipped with a wind speed sensor or the like in each air-conditioned room, it is possible to provide an economical and efficient air conditioner. You can

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an air volume control system of an embodiment of an air conditioner according to the present invention, FIG. 2 is an air blowing characteristic diagram showing a relation between air volume and pressure of a fan used in the same embodiment, and FIG.
The figure is a characteristic diagram showing the relationship between the damper opening and the ventilation loss coefficient.
FIG. 4 is a flow chart showing an example of control operation in the trial operation mode of the above embodiment, FIG. 5 is a flow chart showing an example of control operation during the air conditioning operation of the above embodiment, and FIG. 6 is a configuration showing a conventional air conditioner. It is a figure. 1 is an air-conditioned room, 2 is a centralized blower, 4 is a heat exchanger, 5 is a blower, 6 is a main duct, 7 is a branch duct, 8 is a blower adjusting means, 9 is a damper, 14 is a room thermostat, 19 is an air volume A detector, 20 is a damper control means, 21 is an air volume measuring means, 22 is a blower control means, and 23 is an arithmetic processing means. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A centralized blower for blowing air to a plurality of air-conditioned rooms through a main duct and a branch duct connected to the blower, the blower having a heat exchanger and the heat exchanged by the heat exchanger.
Blower adjusting means attached to each of the branch ducts for adjusting the amount of cool air or warm air to the air-conditioned room by opening and closing a damper, damper control means for controlling the opening and closing of the damper of the air blow adjusting means, and the blower. Blower control means for setting the power supply to a predetermined frequency to a predetermined frequency, air volume measuring means for measuring the actual air volume by detecting the air volume from the blower by an air volume detector, the air blower control means and the air volume measuring means And each output of the damper control means, the ventilation loss characteristic of each branch duct is obtained from the amount of blown air and the difference in blowing pressure at the set frequency of the blower when the blower adjusting means is fully opened. Based on the ventilation loss characteristics of the damper, the maximum value of the blast pressure difference necessary for each blast adjusting means is obtained during the air conditioning operation, and the maximum value of the blast pressure difference is calculated. An arithmetic processing unit that controls the damper control unit according to the degree of opening and closing of each damper having the required air flow rate by each air flow adjustment unit, and controls the blower control unit to a frequency that has the maximum value of the air flow pressure difference with respect to the sum of the required air flow amounts of the air flow adjustment unit An air conditioner comprising: