JPH11325632A - Method for controlling air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately sense an abnormal stop of an outdoor blower without using a current detecting sensor by detecting a temperature of an outdoor heat exchanger at each predetermined time until a predetermined time is elapsed after a heating operation is started, and obtaining a difference between the temperature detected at the last and a lowest value of the detected temperatures. SOLUTION: After about 10 sec is elapsed at the time of starting a heating operation, a temperature Tn of an outdoor heat exchanger is detected by a temperature sensor 16, and stored in a memory 14a. After a series of operations are conducted until about 15 min is elapsed, a temperature Ta of the exchanger is once again detected, and whether a difference between a lowest value of the temperature Tn detected so far and the temperature Ta detected at the last is 5 deg.C or more or not is decided. If the decision indicates NO, a compressor is stopped while an outdoor blower 13 remains operating, and whether a difference between a temperature Ta' of the exchanger 5 after a predetermined time and the lowest value of the temperature Tn is 5 deg.C or more or not is decided. If the decision is NO, it is decided that the blower 13 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control technique for a heating operation of an air conditioner, and more particularly, to a control method of an air conditioner which enables an abnormal stop of an outdoor blower to be estimated from a temperature state of an outdoor heat exchanger. About.

[0002]

2. Description of the Related Art A refrigeration cycle of an air conditioner is shown in FIG.
As shown in FIG. 1, the compressor 1 is composed of a compressor 1, a four-way valve 2, an indoor heat exchanger 3, a pressure reducing device 4 such as a capillary tube, and an outdoor heat exchanger 5, and discharged from the compressor 1 during the heating operation. The high-temperature and high-pressure refrigerant flows through the four-way valve 2, the indoor heat exchanger 3, the pressure reducing device 4, and the outdoor heat exchanger 5 in this order.
Through the compressor 1.

FIG. 5 shows a control system of an air conditioner. An indoor unit A includes an indoor heat exchanger 3 and an indoor heat exchanger 3.
An indoor blower 6 for sending out the heat exchanged air into the room,
A wind direction adjusting device 7 for adjusting the wind direction into the room, an indoor unit control unit 8 for controlling these units, a notifying unit 9 for notifying the occurrence of an abnormality in the equipment, and the like are provided. Information on the temperature of the indoor heat exchanger 3 detected at
Information on room temperature detected by temperature sensor 11, remote control
Signals and the like from 12 are input, and the air exchanged by the outdoor heat exchanger 5 in addition to the compressor 1, the four-way valve 2, the pressure reducing device 4, and the outdoor heat exchanger 5 is sent to one outdoor unit B. An outdoor blower 13 for sending out to the outside, an outdoor unit control unit 14 for controlling the compressor 1, the four-way valve 2, the outdoor blower 13 and the like are provided, and a temperature sensor for detecting the temperature is provided in a discharge pipe of the compressor 1. 15 is
The outdoor heat exchanger 5 has a temperature sensor 16 for detecting the temperature of the outdoor heat exchanger 5, and the power line of the compressor 1 has a current sensor 17.
However, a current sensor 18 is provided on a power supply line of the outdoor blower (using an AC motor) 12, and an abnormal stop of the outdoor blower 13 is estimated from a change in a current detected by the current sensor 18. .

[0004]

By the way, during the cooling operation, the temperature of the outdoor heat exchanger 5 becomes high and high, and when the outdoor blower 13 stops abnormally, the pressure (in-pipe pressure) and the temperature of the outdoor heat exchanger 5 rise rapidly. Therefore, the abnormality of the outdoor blower 13 can be estimated from the temperature of the outdoor heat exchanger 5 detected by the temperature sensor 16, and the current sensor 18 is not always necessary. However, during the heating operation, the outdoor heat exchanger 5 side has low temperature and low pressure. Therefore, even if the outdoor blower 13 stops abnormally, the temperature rise of the outdoor heat exchanger 5 is small, and it is said that it is difficult to estimate the abnormal stop of the outdoor blower 13 from this amount of temperature change, and the current sensor 18 has been used. However, the use of the current sensor 18 has a problem in terms of labor and cost required for its installation. Therefore, an object of the present invention is to provide a control method of an air conditioner that can accurately detect an abnormal stop of an outdoor blower without using a current detection sensor.

[0005]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and comprises an indoor heat exchanger, an indoor blower for sending air heat exchanged by the indoor heat exchanger to a room, An indoor unit having an indoor unit control unit for controlling the indoor blower, etc., an outdoor heat exchanger, a temperature sensor for detecting the temperature of the outdoor heat exchanger, a compressor, a four-way valve, a pressure reducing device, and an outdoor blower In an air conditioner including an outdoor unit having an outdoor unit control unit and the like for controlling these, the temperature of the outdoor heat exchanger is detected at regular intervals until a predetermined time has elapsed since the start of the heating operation. When the difference between the detected temperature and the minimum value of the temperatures detected so far is equal to or more than a predetermined value, the normal heating operation is performed, and when the difference is less than the predetermined value, the operation of the compressor is stopped for a predetermined time. Later, the temperature of the outdoor heat exchanger was detected again, And degree, the difference between the minimum value when the predetermined value or more performs the normal heating operation, and when less than a predetermined value and to perform control so as to stop the power supply to the outdoor blower. Further, the power supply to the outdoor blower is stopped, and the notification unit notifies that the outdoor blower is abnormal. Further, the predetermined value of the temperature difference was set to 5 ° C.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. In FIG. 1, the same and corresponding parts as those in FIG. See FIG. 4 for the refrigeration cycle of the air conditioner.

FIG. 1 schematically shows a control system of an air conditioner, in which A is an indoor unit having an indoor unit control section 8, a notifying section 9 and the like, and B is a compressor 1, a four-way valve 2, an outdoor blower. An outdoor unit provided with an outdoor unit control unit 14 for controlling 13 and the like.
Is provided with a storage section 14a for storing the temperature of the outdoor heat exchanger 5 detected by the temperature sensor 16, a temperature comparison section 14b for performing a temperature comparison operation described later, and the like. The indoor unit controller 8 drives the indoor blower 6 and the like in accordance with a signal from the remote controller 12, detects the room temperature, compares the detected room temperature with the temperature set by the remote controller, and issues a command such as an operating frequency code of the compressor 1 in accordance with the comparison result. Is transferred to the outdoor unit control unit 14. The outdoor unit control unit 14 controls the compressor 1 according to the command (including the operation start command), drives the outdoor blower 13 and controls the four-way valve 2.

By the way, if the heating operation is started and the compressor 1, the outdoor blower 13 and the like are operating normally, the temperature of the outdoor heat exchanger 5 draws a curve shown by a solid line in FIG. Although the so-called pull-down characteristic of the refrigerant, which turns down and then rises, is detected, when the outdoor blower 13 is in the abnormal stop state, the temperature of the outdoor heat exchanger 5 remains lowered as shown by the broken line. In the present invention, such a temperature change of the outdoor heat exchanger 5 at the time of starting the heating operation is monitored, and when the pull-down characteristic of the refrigerant is detected, the outdoor blower 13 is determined to be normal and not detected. In case of outdoor blower 13
Is determined to have stopped abnormally, and control such as stopping the operation of the compressor 1 is performed. Hereinafter, the control method will be specifically described.

FIG. 3 shows an example of a control operation after the heating operation is started. When the heating operation is started, 1 is set in step ST1.
After waiting for 0 seconds, the temperature Tn of the outdoor heat exchanger 5 is detected in step ST2, and the detected temperature Tn is stored in the storage unit 14a in step ST3.
After repeated 15 minutes shown in FIG. 4, the temperature Ta of the outdoor heat exchanger 5 is detected again in step ST5, and in step ST6, the minimum value of the temperature Tn detected so far (see FIG. 2). And the last detected temperature T
It is determined whether or not the difference from “a” is 5 ° C. or more.

If the conditions are satisfied, it is assumed that the compressor 1 and the outdoor blower 13 are operating normally.
The process proceeds to step ST7 to shift to normal heating operation. If the determination condition is not satisfied, step ST8 is performed.
The operation of the compressor 1 is stopped while energizing the outdoor blower 13 is continued, and this state is maintained for 10 minutes in step ST9, and then the operation proceeds to step ST10, where the outdoor heat exchanger 5
Is detected again, and this is set as Ta '.
And whether the difference between the minimum value of the temperature Tn of the outdoor heat exchanger 5 detected so far (see FIG. 2) and the temperature Ta ′ of the outdoor heat exchanger 5 detected again is 5 ° C. or more. Is determined.

The reason is that the pull-down characteristic shown in FIG. 2 is not always constant, but also becomes a characteristic shown by a broken line (thick line) depending on the operating conditions and the like, and even if there is no abnormality in the outdoor blower 6. The difference between the minimum value of Tn and Ta is determined in step ST6.
In such a case, the operation of the compressor 1 may be stopped for a long time, or the immediate notification that the outdoor blower 13 is abnormal may be inconvenient for the user. It is because it will be applied.

Therefore, in implementing the present invention, the temperature of the outdoor heat exchanger 5 is determined twice as described above, and if the determination conditions are satisfied in step ST11, the compressor 1 and the outdoor blower 13 are activated. It is assumed that the air conditioner is operating normally, and the process proceeds to step ST7 to shift to the normal heating operation. If the determination condition is not satisfied, it is determined that the outdoor blower 13 has stopped abnormally, and ST
The process proceeds to step 12 to stop energization of the outdoor blower 13, while the process proceeds to step ST13 to notify the abnormality of the outdoor blower 13 by the notification unit 9 provided on the indoor unit side.

[0013]

According to the air conditioner having the above-described control function, it is possible to detect an abnormal stop of the outdoor blower without providing a current sensor on the power supply line of the outdoor blower. In addition to helping to prevent the destruction of electrical components,
Since a current sensor is not required, it contributes to cost reduction.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control system of an air conditioner showing an application example of a control method of the present invention.

FIG. 2 is a temperature characteristic diagram of an outdoor heat exchanger at the beginning of a heating operation of an air conditioner.

FIG. 3 is a flowchart showing an outline of a control operation of the present invention.

FIG. 4 is a schematic diagram of a refrigeration cycle of an air conditioner according to the present invention and a conventional example.

FIG. 5 is a block diagram of a control system of an air conditioner showing a conventional example.

[Explanation of symbols]

 A indoor unit B outdoor unit 1 compressor 2 four-way valve 3 indoor heat exchanger 4 decompression device 5 outdoor heat exchanger 8 indoor unit control unit 9 notification unit 12 remote controller 13 outdoor blower 14 outdoor unit control unit 16 temperature sensor (outdoor heat exchange) Dexterous)

Claims (3)

[Claims] 1. An indoor heat exchanger, an indoor blower for sending air heat exchanged by the indoor heat exchanger into a room, an indoor unit control unit for controlling the indoor blower, and a notification for notifying an abnormality of a device. Unit, an outdoor heat exchanger, a temperature sensor for detecting the temperature of the outdoor heat exchanger, a compressor, a four-way valve, a pressure reducing device, an outdoor blower, and an outdoor unit control unit for controlling these units In an air conditioner comprising an outdoor unit equipped with the like, the temperature of the outdoor heat exchanger is detected at regular intervals until a predetermined time has elapsed after the start of the heating operation, and the temperature detected last and the When the difference between the detected temperature and the minimum value is equal to or greater than a predetermined value, the normal heating operation is performed, and when the difference is less than the predetermined value, the operation of the compressor is stopped for a predetermined time and then the temperature of the outdoor heat exchanger is reset. Detected, and the difference between this temperature and the minimum value is a predetermined value. In the above case, the normal heating operation is performed, and when it is less than a predetermined value, control is performed so as to stop energizing the outdoor blower. 2. The control of the air conditioner according to claim 1, wherein the power supply to the outdoor blower is stopped, and the notification unit notifies that the outdoor blower is abnormal. Method. 3. The method according to claim 1, wherein the predetermined value of the temperature difference is 5 ° C.