JP6052271B2 - Fan speed determination method and air conditioner - Google Patents

Description

  The present invention relates to a method for determining the number of rotations of a fan when an air conditioner having a fan that blows air using a duct is installed on site.

  An air conditioner having a fan that blows air using a duct has different ventilation resistance and different external static pressure depending on the form of the duct (for example, length and bending). If the fan speed is constant, the actual air flow varies depending on the external static pressure. In order to keep the air volume constant regardless of the static pressure outside the machine, it is necessary to set the fan speed according to the static pressure outside the machine at the time of installation.

  The air volume can be estimated based on the fan speed and the operating power at the fan speed without actually measuring the air volume itself. Therefore, for example, a duct-type air conditioner that controls to provide an operating power or a fan speed necessary to obtain a rated airflow based on the operating power when the fan is operated at a constant fan speed has been proposed ( For example, see Patent Document 1.)

  In addition, typically as an airflow level, there are H tap, M tap, and L tap (for example, refer patent document 2). When setting the fan speed at the time of installation, the fan speed is set to satisfy the rated air volume at the H tap.

Japanese Patent Laid-Open No. 10-141747 JP-A-8-261548

  However, the voltage of the commercial power supply may be lower than the rated voltage due to local circumstances. Even in Japan where the power supply quality is stable, for example, indoor wiring for an air conditioner may not be a single wiring, and in such a case, a voltage drop occurs. In some foreign countries where power conditions are not stable, the voltage of the commercial power supply itself may be lower than the rated voltage.

In such a situation, even if the fan speed is increased to try to obtain the rated airflow, the necessary fan speed will not be sufficient, and as a result, the inconvenience will occur that the fan speed cannot be determined by repeating the retry. There is a case.
In addition to the voltage problem, if the temperature is abnormally low, the air density may increase and the external static pressure may increase. Even in such a case, it may be difficult to search for the fan speed for obtaining the rated air volume.

  In view of such a conventional problem, an object of the present invention is to make it possible to determine the fan rotation speed even if the installation situation is inconvenient for the determination of the fan rotation speed.

  (1) The present invention relates to a fan rotational speed determination method executed by the air conditioner to output a predetermined rated air volume from the duct in an air conditioner with constant air volume control having a fan that blows air using a duct. Assuming that the highest airflow level is the first tap and the lower airflow level is the second tap, (i) the fan is driven by the first tap, and the fan rotation speed at which the airflow of the fan becomes the rated airflow. (Ii) If the fan speed can be searched with the first tap, the fan speed is determined as the fan speed of the first tap, and the state where the rated air volume is not reached continues. (Iii) the fan is driven by the second tap, and the fan air volume becomes the air volume of the second tap. Explore the rotational speed, a (iv) determining the fan rotation speed of searching by the second tap as a fan rotation speed of the second tap, the fan rotation speed determining method.

  According to such a fan rotation speed determination method, for example, when a duct-type air conditioner is installed, for example, an appropriate voltage for driving the fan can be obtained, the fan rotation speed can be determined with the first tap. The fan rotation speed of the second tap can be determined based on the fan rotation speed of the first tap. On the other hand, for example, when the voltage for driving the fan is insufficient, the rated air volume may not be reached at the first tap for some reason. In that case, the fan rotation speed can be determined by the second tap by lowering to the second tap regardless of the first tap. The fan rotation speed of the first tap can be determined based on the fan rotation speed of the second tap.

  (2) Also, in the fan speed determination method of (1), during the search for the fan speed at the first tap, the correction of the fan speed reaches a predetermined number of times, and the fan at the first tap You may make it detect that the state which does not reach the said rated air volume continues by trying to drive the said fan with the fan rotation speed exceeding the upper limit of rotation speed.

  For example, when the voltage for driving the fan is lower than an appropriate voltage, the rated air volume is not reached even at a fan speed at which the rated air volume can be obtained if the voltage is appropriate. If it will be in this state, the operation | movement which corrects (increases) fan rotation speed and tries to obtain a rated air volume will be performed. However, if the rated air volume cannot be obtained even after the correction, an operation is performed in which the fan speed is further corrected (increased) to obtain the rated air volume. Similarly, the number of times of fan rotation speed correction increases. Therefore, the state in which the rated air volume is not reached continues by trying to drive the fan at a fan speed exceeding the upper limit value of the fan speed at the first tap after the fan speed has been corrected a predetermined number of times. Can be detected.

  (3) Also, in the fan rotation speed determination method of (1), during the search for the fan rotation speed at the first tap, the correction of the fan rotation speed reaches a predetermined number of times, and the operating power of the fan is You may make it detect that the state which does not reach the said rated airflow is continuing by being in the state where it is less than the lower limit of the driving power in a 1st tap.

  When the operating power is small (the air volume is small) relative to the fan speed, an operation is performed to correct (increase) the fan speed to reach a predetermined power. However, if the predetermined power is not reached even after the correction, an operation for further correcting (increasing) the fan rotational speed to reach the predetermined power is performed. Similarly, the number of times of fan rotation speed correction increases. Therefore, when the fan speed has been corrected a predetermined number of times and the operating power of the fan is less than the lower limit value of the operating power at the first tap, the state where the rated air volume is not reached continues. Can be detected.

(4) On the other hand, the air conditioner of the present invention is an air conditioner of constant air volume control including a fan that blows air using a duct and a control unit having a function of performing drive control of the fan. If the air volume level is the first tap and the lower air volume level is the second tap,
The control unit drives the fan with the first tap, searches for the fan speed at which the air volume of the fan becomes the rated air volume, and if the fan speed can be searched for with the first tap, the fan speed is set. When the fan speed of the first tap is determined, and when it is detected that the rated air volume is not reached, switching to the second tap is performed, and the fan is turned on by the second tap. The fan is driven to search for the fan speed at which the air volume of the fan becomes the air volume of the second tap, and the fan speed searched with the second tap is determined as the fan speed of the second tap.

  In such a duct-type air conditioner, for example, when an appropriate voltage for driving the fan is obtained at the time of installation, the fan rotation speed can be determined by the first tap. The fan rotation speed of the second tap can be determined based on the fan rotation speed of the first tap. On the other hand, for example, when the voltage for driving the fan is insufficient, the rated air volume may not be reached at the first tap for some reason. In that case, the fan rotation speed can be determined by the second tap by lowering to the second tap regardless of the first tap. The fan rotation speed of the first tap can be determined based on the fan rotation speed of the second tap.

  According to the present invention, it is possible to determine the fan rotation speed even when the installation situation is inconvenient for the determination of the fan rotation speed.

It is a side view which shows an example of a duct type air conditioner which has a fan which ventilates using a duct. It is sectional drawing which shows an example of the internal structure of an indoor unit. It is a characteristic view which shows an example of the relationship between a fan rotation speed and an air volume. It is a block diagram of an indoor unit of an air conditioner that focuses only on the function of determining the number of fan rotations during installation. It is a flowchart which shows the fan speed determination method performed by the control part.

《Overall configuration as an air conditioner (only main part)》
FIG. 1 is a side view showing an example of a duct-type air conditioner 1 having a fan that blows air using a duct. The duct type air conditioner 1 is attached to the back of a ceiling, for example. The air conditioner 1 is for sending air to a suction side duct 1b for sucking indoor air from an air inlet 1a provided on the ceiling 2, an indoor unit 1c, and an air outlet 1e provided on the ceiling 2. And a blowout side duct 1d. A filter chamber 1f that removes dust is provided between the indoor unit 1c and the suction duct 1b.

  FIG. 2 is a cross-sectional view showing an example of the internal structure of the indoor unit 1c. The indoor unit 1c includes a fan 11 that sucks and blows air and a heat exchanger 12 as main structural components in a housing 10. The indoor unit 1c is connected to an outdoor unit (not shown) through a refrigerant pipe. The air sucked by the fan 11 exchanges heat with the heat exchanger 12, becomes cold air or warm air, and is blown out into the room.

<Example of characteristics>
FIG. 3 is a characteristic diagram showing an example of the relationship between the fan speed and the air volume. After installing the duct-type air conditioner 1 as described above, it is necessary to determine the number of fan rotations according to the external static pressure depending on the form of the duct. Here, when the voltage supplied from the commercial power supply is an appropriate value and there is no other special circumstances (for example, extremely low temperature), it is assumed that the characteristic indicated by the solid line is obtained. That is, when the fan rotation speed is increased, the air volume is increased accordingly.

In the fan rotational speed N _H, obtained H taps air volume (Teikakufuryou) is, the fan rotational speed N _M, the air volume of the M taps obtained, the fan rotational speed N _L, the air volume of the L taps can be obtained .
In other words, here, the highest air volume among the plurality of air volumes is H tap (first tap), the lower air volume is M tap (second tap), and the lower air volume is L tap (third tap). In an air conditioner that performs constant air volume control regardless of the external static pressure, the determination tap for determining the fan rotation speed for obtaining the rated air volume is normally an H tap, but in this embodiment, an M tap is also used.

Here, for example, assuming that the voltage has fallen into an appropriate value, even if the fan speed is increased, no power is generated and no air volume is generated. Therefore, for example, the characteristic is as indicated by a dotted line. In this case, in order to obtain the rated air volume with the H tap, the fan rotation speed must be increased to N _HX, but the voltage is low and cannot be increased to that level. Therefore, no matter how many attempts are made to obtain the rated air volume with the H tap, the fan rotation speed cannot be determined without being achieved. If the number of fan rotations is not determined, the setting work at the time of installation is once completed. This is very inconvenient for the installation side. Therefore, the fan rotational speed is determined by the following hardware configuration and functions realized by software using the hardware configuration.

<Hardware configuration for determining fan speed>
FIG. 4 is a block diagram of the indoor unit 1c of the air conditioner that focuses only on the function of determining the number of fan rotations during installation. The indoor unit 1 c includes a fan (including a motor) 11 and a control unit 13. The control unit 13 includes a drive unit 13a for driving the fan, and a fan rotation speed determination unit 13b as a functional unit. The fan 11 incorporates a fan rotation speed sensor (not shown), and provides information on the fan rotation speed to the fan rotation speed determination unit 13b. Further, the fan rotation speed determination unit 13b receives information on the operating power provided to the fan 11 from the drive unit 13a. The fan rotation speed determination unit 13b instructs the drive unit 13a to select a tap to be selected and to instruct the fan rotation speed.

<Method for determining fan speed>
Next, a description will be given of a fan rotation speed determination method mainly at the time of installation.
FIG. 5 is a flowchart showing a fan rotation speed determination method executed by the control unit 13 (fan rotation speed determination unit 13b).
In the figure, when the operator performs an operation to determine the fan rotation speed for the first time after installing the air conditioner on site, the control unit 13 first determines whether or not the condition that requires tap switching is satisfied. Is performed (step S1).

Specifically, the control unit 13 determines whether the following four conditions (a) to (d) are all satisfied as AND conditions. That is,
(A) H tap is selected,
(B) The fan rotational speed instructed to the drive unit 13a is higher than the H-tap fan rotational speed upper limit,
(C) The number of corrections of the fan speed has already reached the predetermined number Nh1, and
(D) It is permitted to switch to the M tap and search for the fan speed (the flag for switching to the M tap is “1”).
An appropriate natural number can be set for Nh1 according to the model of the air conditioner.

  Here, (a) is a precondition for switching to M taps. (B) is that a higher fan speed is instructed to a level higher than the upper limit of the H-tap fan speed, that is, such a fan speed does not occur even if an instruction is given. (C) is that the fan speed has already been corrected a predetermined number of times or more in order to search for the fan speed. In other words, (d) is, for example, that the power is sufficient and it is not an unnecessary model such as switching to an M tap.

The case of “Yes” in step S1 will be described later.
If the voltage provided from the commercial power supply is an appropriate value, for example, the conditions (b) and (c) are not satisfied, so the determination in step S1 is “No”, and the control unit 13 determines that the operating power is predetermined. It is determined whether it is within the range (step S2). That is, the average power P _AV per unit time, where P _{min is} the lower limit value of the normally assumed operating power and P _max is the upper limit value,
P _min ≤ P _AV ≤ P _max
If “Yes”, “Yes” is set, and the control unit 13 determines the fan speed for obtaining the rated air volume (step S8).

On the other hand, in the case of “No” in step S2, the control unit 13 determines whether or not it is appropriate to determine the fan rotation speed with the H tap (step S3). Here, the control unit 13 determines whether or not the following conditions (e), (f), and (g) are all satisfied as AND conditions. That is,
(E) The number of rotations correction is a predetermined number Nh0 or more,
(F) currently being an H tap, and
(G) There is no need to switch to M taps.
An appropriate natural number can be set for Nh0 according to the model of the air conditioner.

The above (e) is a condition that time is wasted even if the number of fan rotations has already been corrected a sufficient number of times. (F) is a precondition. More specifically, (g) corresponds to one of the following conditions (OR). That is,
(G1) For example, a model with power and a flag for switching to an M tap is “0”, or (g2) a model capable of switching to an M tap (the switching flag is “1”). driving power _{P AV} is that it exceeds the upper limit value _{P max,} is. (G2) is, in other words, if the operating power does not reach the assumed upper limit value, there is a possibility of a voltage drop and should be switched to M taps, but the operating power exceeds the upper limit value. If so, there is no need to try M taps.

If “Yes” in step S3, the control unit 13 determines the number of fan rotations for obtaining the H-tap air volume (step S8).
On the other hand, if “No” is determined in the step S3, the control unit 13 determines whether or not the rotation speed correction is performed a predetermined number of times with M taps (step S4). Specifically, the AND condition that the M tap is selected and the number of corrections of the fan rotation speed has reached Nm times needs to be satisfied. If “Yes” in step S4, the control unit 13 determines the fan rotation speed for obtaining the M-tap air volume (step S8).
An appropriate natural number can be set for Nm according to the model of the air conditioner.

  If “No” in step S4, the control unit 13 performs “switching determination 2” to determine whether the condition for tap switching is satisfied (step S5).

Specifically, the control unit 13 determines whether the following four conditions (h) to (k) are all satisfied as AND conditions. That is,
(H) the average value P _AV of the unit time of the operating power is smaller than the assumed lower limit value P _min ;
(I) The number of corrections of the fan rotational speed has already reached the predetermined number Nh2,
(J) H tap is selected,
(K) It is permitted to switch to the M tap and search for the fan speed (the flag for switching to the M tap is “1”).
An appropriate natural number can be set for Nh2 according to the model of the air conditioner.

The case of “Yes” in step S5 will be described later.
If “No” in step S5, the control unit 13 corrects the instruction rotational speed of the fan rotational speed (step S7), returns to step S1, and repeats the same processing. The number of corrections is counted cumulatively.

  If the determination at step S2 or S3 at the H tap is “Yes” while correcting the fan rotation speed, the control unit 13 determines the fan rotation speed for obtaining the air volume of the H tap (step S1). S8).

  For example, when the voltage for driving the fan 11 is lower than an appropriate voltage, the rated air volume is not reached even if the fan speed is such that the rated air volume can be obtained if the voltage is appropriate. If it will be in this state, the operation | movement which corrects (increases) fan rotation speed and tries to obtain a rated air volume will be performed. However, if the rated air volume cannot be obtained even after the correction, an operation is performed in which the fan speed is further corrected (increased) to obtain the rated air volume. Similarly, the number of times of fan rotation speed correction increases. Therefore, the state in which the rated air volume is not reached continues by trying to drive the fan 11 at a fan speed exceeding the upper limit value of the fan speed at the H tap when the correction of the fan speed reaches a predetermined number of times. Can be detected. In this case, “Yes” is determined in step S1.

If “Yes” in step S1, the control unit 13 performs switching from the H tap to the M tap (step S6). Thus, the fan speed is searched based on the M-tap fan speed. Further, the target operating power is calculated with an M tap target. Further, the fan rotation speed correction count is reset to zero. And the control part 13 performs the instruction | indication rotation speed correction (step S7) of the first, and returns to step S1.
As a result, if any of the determinations in steps S2 and S4 is "Yes", the control unit 13 determines the fan rotation speed for obtaining the M tap air volume corresponding to the H tap rated air volume (step S8). ).

Further, when the operating power is small (the air volume is small) relative to the fan rotation speed, an operation for correcting (increasing) the fan rotation speed to reach a predetermined power is performed. However, if the predetermined power is not reached even after the correction, an operation for further correcting (increasing) the fan rotational speed to reach the predetermined power is performed. Similarly, the number of times of fan rotation speed correction increases. Therefore, during the search for the fan speed with H tap, the fan speed has been corrected a predetermined number of times (Nh2), and the operating power of the fan is less than the lower limit value (P _min ) of the operating power with H tap. Therefore, it can be detected that the state where the rated airflow is not reached continues. In this case, “Yes” is determined in step S5.

If “Yes” in step S5, the control unit 13 performs switching from the H tap to the M tap (step S6). Thus, the fan speed is searched based on the M-tap fan speed. Further, the target operating power is calculated with an M tap target. Further, the fan rotation speed correction count is reset to zero. And the control part 13 performs the instruction | indication rotation speed correction (step S7) of the first, and returns to step S1.
As a result, if any of the determinations in steps S2 and S4 is "Yes", the control unit 13 determines the fan rotation speed for obtaining the M tap air volume corresponding to the H tap rated air volume (step S8). ).

  According to the fan rotational speed determination method as described above, the fan rotational speed can be determined with an H tap if an appropriate voltage for driving the fan is obtained when the duct-type air conditioner is installed. The fan rotation speed of the M tap can be determined based on the fan rotation speed of the H tap. On the other hand, for example, when the voltage for driving the fan is insufficient, the rated air volume may not be reached with the H tap for some reason. In that case, the fan rotation speed can be determined by M taps by lowering to M taps, not sticking to H taps. The fan rotation speed of the H tap can be determined based on the fan rotation speed of the M tap.

  Further, even if the fan rotation speed and the operating power corresponding to the air volume at the H tap or M tap cannot be reached by the processing of steps S3 and S4, in other words, even if there is some shortage, the fan rotation speed is determined. Thus, it is possible to prevent the fan rotation speed from being determined. That is, the process shown in the flowchart of FIG. 5 always reaches step S8 and ends.

<Others>
The above fan speed determination method is mainly used when installing a duct-type air conditioner. However, the ventilation resistance may change due to dirt on the duct due to long-term use. May be.

  Moreover, although the said embodiment demonstrated switching from H tap to M tap supposing that a voltage fell from a rated voltage, For example, it is the same also when the temperature at the time of installation is abnormally low In addition, the load is heavy for the fans. Accordingly, even in such a case, if the rated air volume does not appear with the H tap, the fan rotation speed can be determined with the M tap.

  In the above-described embodiment, switching from the H tap to the M tap has been described. However, when the fan rotation speed cannot be determined even with the M tap, the fan rotation speed is further determined with the L tap after switching to the L tap. This is basically possible, regardless of practicality.

DESCRIPTION OF SYMBOLS 1 Air conditioner 1a Intake port 1b Suction side duct 1c Indoor unit 1d Outlet side duct 1e Outlet 1f Filter chamber 2 Ceiling 10 Case 11 Fan 12 Heat exchanger 13 Control part 13a Drive part 13b Fan rotation speed determination part

Claims (4)

In an air conditioner (1) with constant air volume control having a fan (11) that blows air using a duct (1b, 1d), the air conditioner is used to output a predetermined rated air volume from the duct (1b, 1d). Is the method for determining the fan speed, and if the highest airflow level is the first tap and the lower airflow level is the second tap,
The fan (11) is driven by the first tap, and the fan rotation speed at which the air volume of the fan (11) becomes the rated air volume is searched.
If it is possible to search the fan rotation speed with the first tap, the fan rotation speed is determined as the fan rotation speed of the first tap, and when it is detected that the state where the rated air volume is not reached continues, Switch to the second tap,
The fan (11) is driven by the second tap, and the fan rotation speed at which the air volume of the fan (11) becomes the air volume of the second tap is searched.
The fan rotation speed searched with the second tap is determined as the fan rotation speed of the second tap.
How to determine fan speed.   During the search of the fan rotation speed at the first tap, the fan (11) has a fan rotation speed that has reached a predetermined number of times and exceeds the upper limit of the fan rotation speed at the first tap. The fan rotational speed determination method according to claim 1, wherein the state where the rated air volume is not reached is detected by trying to drive the fan.   During the search for the fan speed at the first tap, the fan speed has been corrected a predetermined number of times, and the operating power of the fan (11) is less than the lower limit value of the operating power at the first tap Therefore, the fan rotational speed determination method according to claim 1, wherein it is detected that the state where the rated air volume is not reached continues. A fan (11) for blowing air using ducts (1b, 1d);
A control unit (13) having a function of performing drive control of the fan (11), and an air conditioner (1) of constant air volume control,
If the highest airflow level is the first tap and the lower airflow level is the second tap,
The control unit (13) drives the fan (11) with the first tap, searches for the fan speed at which the air volume of the fan (11) becomes the rated air volume, and sets the fan speed with the first tap. If the search can be performed, the fan rotation speed is determined as the fan rotation speed of the first tap, and when it is detected that the rated air volume is not reached, switching to the second tap is executed. The fan (11) is driven by the second tap, the fan rotation speed at which the air volume of the fan (11) becomes the air volume of the second tap is searched, and the fan rotation speed searched by the second tap is An air conditioner that is determined as the fan rotation speed of the second tap.

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