JPH0735391A - Control device for air conditioner - Google Patents

Abstract

PURPOSE:To provide a control device for an air conditioner which is capable of controlling the operation such that when there does not reach a predermined value temperature rise, after the lapse of a predermined time upon weak or fine operation of a fan air amount of an indoor machine, an operation frequency limit is released to permit room temperature to rapidly reach set temperature. CONSTITUTION:A control device for an air conditioner including an inverter portion 10 which controls the operation frequency of a compressor 11 in response to air-conditioned load upon heating operation comprises an indoor heat exchanger temperature sensor 2 for detecting the temperature of the indoor heat exchanger, an outdoor heat exchanger temperature sensor 9 for detecting the temperature of an outdoor heat exchanger, and control means for controlling the operation frequency of the compressor 11. When the temperatures of the temperature sensors 2, 9 are predetermined values or lower, and when the operation of the compressor 11 by control means continues at an allowable maximum operation frequency wuithin a frequency limit over a predermined time interval, the frequency limit is released and the compressor 11 is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an air conditioner equipped with an inverter. The air conditioner is designed so that the fan air volume of the indoor unit can be switched in steps such as strong, weak, and fine by a remote control.In recent years, in order to reduce the operating noise of the air conditioner, the fan motor of the indoor unit is reduced. The number of rotations of is becoming low.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of a conventional air conditioner, FIG. 4 is a flow chart showing control of heating operation of a conventional air conditioner, and FIG. 5 is an operating frequency of a compressor. It is explanatory drawing which shows the code. Hereinafter, a conventional example will be described with reference to FIGS. 3, 4, and 5. In step S1, the indoor unit control unit 21 determines whether the set air volume of the indoor fan motor 3 operated using the operation unit 5 is weak or slight. If it is neither weak nor slight, in step S5, the indoor unit control unit 21 is determined. Is controlled by selecting an H code signal from 0 to E shown in FIG. 5 according to the difference between the desired room temperature set in the temperature setting unit 6 using the operation unit 5 and the room temperature detected by the indoor sensor 4. The signal is output as a signal and input to the outdoor unit control unit 28, and the outdoor unit control unit 28 controls the inverter unit 10 so that the operating frequency corresponds to the input H code signal, and the compressor 11 causes the so-called normal frequency. I was in a driving state.

When the air conditioning load is light, that is, when the difference between the desired room temperature set in the temperature setting section 6 and the room temperature detected by the indoor sensor 4 is small, or the indoor fan motor 3 is used.
If the set air volume is low or low, the indoor unit control unit 21 uses the operation unit 5 to set the temperature setting unit 6 in step S2.
In accordance with the difference between the desired room temperature set in step 1 and the room temperature detected by the indoor sensor 4, the H code signals 0 to 6 shown in FIG. 5 are selected and output as control signals and input to the outdoor unit controller 28. Then, the outdoor unit control unit 28 controls the inverter unit 10 to perform the frequency limited operation.

In step S3, the indoor unit control unit 21 compares the room temperature set in the temperature setting unit 6 using the operation unit 5 with the temperature detected by the room temperature sensor 4, and determines whether the room temperature has reached the set temperature, If the temperature has not reached the set temperature, the process returns to step S2 to perform the frequency limiting operation of H code 6 or less,
If the set temperature is reached, in step S4, a control signal is output from the indoor unit control unit 21 and input to the outdoor unit control unit 28, and the outdoor unit control unit 28 controls the inverter unit 10 to operate at the operating frequency. Is lowered to a lower limit, for example, H code 1, or the operation is stopped, the process returns to step S3 to determine whether the room temperature has reached the set temperature, and the procedure from step S3 is repeated. As described above, when the air conditioning load is light, that is, when the difference between the desired room temperature set in the temperature setting unit 6 and the room temperature detected by the indoor sensor 4 is small, or the set air volume of the indoor fan motor 3 is weak or very small. In such a case, the operating frequency of the compressor 11 is limited in order to prevent the high pressure of the compressor 11 from rising too much in the overload state.

[0005]

Accordingly, when the set air volume of the indoor fan motor 3 is set to be weak or minute, the compressor 11 is in the frequency limited operation state. Therefore, when the outside air temperature is low, the air conditioning capacity is low. There was a problem that the room temperature became insufficient and it took too long for the room temperature to reach the set temperature. The present invention releases the operating frequency limitation and quickly sets the room temperature when the temperature rise does not reach the predetermined value after the predetermined time even when the fan air volume of the indoor unit is set to weak or slight. An object of the present invention is to provide a control device capable of controlling so as to reach the temperature.

[0006]

A control device for an air conditioner according to the present invention is an air conditioner control device having an inverter for controlling an operating frequency of a compressor according to an air conditioning load during heating operation. First temperature detecting means for detecting the temperature of the heat exchanger, second temperature detecting means for detecting the temperature of the indoor heat exchanger, and control means for controlling the operating frequency of the compressor are provided. When the temperature of the second temperature detecting means is equal to or lower than a predetermined value and the operation of the compressor by the control means continues at the maximum allowable operating frequency within the frequency limit for a predetermined period or more, the frequency limit is canceled to operate. It is a feature.

[0007]

According to the present invention, the control means for controlling the operating frequency of the compressor has the above-mentioned configuration, and the operation of the compressor is continued for a predetermined period or more by the maximum allowable operating frequency within the frequency limit, that is, H code 6 in FIG. If the values detected by the first temperature detecting means for detecting the outdoor heat exchanger temperature and the second temperature detecting means for detecting the indoor heat exchanger temperature do not exceed the predetermined value, the air conditioning capacity is insufficient. It is decided that the frequency limit is released, and in FIG. 5, the operation is performed in any selected state from H code 7 to E so that the room temperature quickly reaches the set temperature. It is possible to control the compressor.

[0008]

1 is a block diagram showing an embodiment of a control device for an air conditioner according to the present invention, in which the same components as those shown in FIG. 3 are designated by the same symbols. . Operation part 5
By operating the, the operation signal is input to the indoor unit control unit 1, and the indoor unit control unit 1 executes a command according to the input operation signal, and, for example, the indoor fan motor 3 is stepped into strong, weak, and fine. The temperature setting unit 6 can set a desired room temperature. An indoor heat exchanger temperature sensor 2 and a room temperature sensor 4 for detecting the indoor heat exchanger temperature are connected to the indoor unit controller 1, and further, an outdoor heat exchanger temperature is detected for the outdoor unit controller 8. The temperature sensor 9 for the outdoor heat exchanger is connected, and the detection signal detected by the temperature sensor 9 for the outdoor heat exchanger is input to the indoor unit control unit 1 via the outdoor unit control unit 8 so that the indoor unit control unit 1 performs indoor operation. A detection signal input from the heat exchanger temperature sensor 2 and the room temperature sensor 4 and a setting signal input from the temperature setting unit 6 are compared, and a control signal is input to the outdoor unit control unit 8. The outdoor unit control unit 8 is connected to the compressor 11 via the inverter unit 10, and changes the frequency of the inverter unit 10 according to the input control signal to change the operating frequency of the compressor 11.

FIG. 2 is a flowchart showing the control of the heating operation of the control device for an air conditioner according to the present invention. In step S1, the indoor unit control unit 1 determines whether the set air volume is weak or slight, and if it is neither weak nor slight, the indoor unit control unit 1 sets the temperature setting unit 6 using the operation unit 5 in step S9. According to the difference between the desired room temperature and the room temperature detected by the indoor sensor 4, the H code signals from 0 to E shown in FIG. 5 are selected and output as a control signal and input to the outdoor unit controller 8. The outdoor unit control unit 8 controls the inverter unit 10 so that the operating frequency corresponds to the input H code signal so that the compressor 11 enters the so-called normal frequency operating state. If it is weak or slight, in step S2, the indoor unit control unit 1 determines whether the desired room temperature set in the temperature setting unit 6 using the operation unit 5 is different from the room temperature detected by the indoor sensor 4. , The H code signals 0 to 6 shown in FIG. 5 are selected and output as a control signal and input to the outdoor unit control unit 8, and the outdoor unit control unit 8 controls the inverter unit 10 to perform the frequency limiting operation. In this way, the operation of the compressor 11 is suppressed so that the high pressure of the compressor 11 does not become too high when the overload condition occurs.

When the outside air temperature is low and therefore the difference between the room temperature and the desired room temperature set in the temperature setting section 6 is large, the compressor 1
1 is the maximum allowable operating frequency within the frequency limit, which is operated by the H code 6 in FIG. 5, but in step S3, the counter 7 provided in the outdoor unit control unit 8 operates at the maximum allowable operating frequency within the frequency limit. It counts whether the driving has exceeded a predetermined period, for example, 20 minutes, and if not, returns to step S2,
The frequency limited operation H code 6 and below is continued. If it exceeds, the process proceeds to step S4, the detection signal detected by the outdoor heat exchanger temperature sensor 9 is input to the indoor unit control unit 1 via the outdoor unit control unit 8, and is preset in the temperature setting unit 6. Compare with the reference temperature, determine if it is less than B (eg -2 ° C),
If it exceeds B, the process returns to step S2 to continue the frequency limiting operation H code 6 and below.

When the temperature does not exceed B, the process proceeds to step S5, the detection signal detected by the indoor heat exchanger temperature sensor 2 is input to the indoor unit control section 1, and is set in the temperature setting section 6 in advance to set the reference temperature. It is compared and it is determined whether the temperature is lower than C (for example, 40 ° C.). If the temperature is higher than C, the process returns to step S2 to continue the frequency limiting operation H code 6 or lower. When the temperature does not exceed C, the process proceeds to step S6, and the indoor unit control unit 1 shows in FIG. 5 according to the difference between the desired room temperature set in the temperature setting unit 6 and the room temperature detected by the indoor sensor 4. H from 7 to E
The code signal is selected and output as a control signal and input to the outdoor unit control unit 8. The outdoor unit control unit 8 controls the inverter unit 10 so that the operating frequency corresponds to the input H code signal.
Is controlled to bring the compressor 11 into a normal frequency operation state.

Further, in step S7, the detection signal detected by the outdoor heat exchanger temperature sensor 9 is input to the indoor unit control unit 1 via the outdoor unit control unit 8 and set in the temperature setting unit 6 in advance to be a reference. The temperature is compared and it is determined whether it is D (for example, 4 ° C.) or more. If it is D or more, the process returns to step S2 to perform the frequency limiting operation H code 6 or less, and if it is less than D, the process proceeds to step S8. The detection signal detected by the indoor heat exchanger temperature sensor 2 is input to the indoor unit control unit 1, which is set in advance in the temperature setting unit 6 and compared with the reference temperature, and E (for example, 5
6 ° C) or higher, and if E or higher, the process returns to step S2 to perform the frequency limiting operation H code 6 or lower,
When it is less than E, the compressor 11 is continuously operated at the normal operation frequency, the process returns to step S7, and the procedure after step S7 is repeated.

Therefore, when the air conditioner is operated for heating, the fan air volume of the indoor unit is set to be weak or minute,
When the air conditioning load is light, the compressor 11 is operated for a predetermined period at the maximum allowable operating frequency H code 6 within the frequency limit, and the temperatures of the outdoor heat exchanger and the indoor heat exchanger do not reach the predetermined values. Is determined to be insufficient, the frequency limitation is released, and the compressor 11 can be operated with the H code of 7 or more. Therefore, it is possible to control so that the room temperature quickly reaches the set temperature. . Further, when the temperature of the outdoor heat exchanger and the temperature of the indoor heat exchanger reach a predetermined value, the frequency limit operation H code 6 or less is set.
It is possible to suppress an increase in the high pressure of the compressor 11 in the overload state, and to perform the frequency limited operation or cancel according to the air conditioning load, so that the air conditioning capacity of the air conditioner can be fully exerted. It becomes possible.

In step S3, a microcomputer is used as the indoor unit control section 1 and a counter built in the microcomputer is used instead of the counter 7, and the outdoor unit control section 8 operates the compressor 11. A signal may be input to the indoor unit control unit 1 and the indoor unit control unit 1 may count the operation period of the compressor 11 at the maximum allowable operation frequency. FIG. 5 is an example showing the codes of the operating frequency of the compressor, and the number of H-codes may be increased or decreased and another value may be used as the numerical value of the operating frequency.

[0015]

As described above, according to the present invention,
When the fan air volume of the indoor unit is set to weak or slight and the temperature rise does not reach the predetermined value after the lapse of the predetermined time, the operating frequency limit of the compressor is released and the room temperature is quickly set to the set temperature. When the temperature rise reaches a predetermined value, the frequency limit operation is performed, so it is possible to suppress the rise of the high pressure of the compressor in the overload state, and to limit the frequency according to the air conditioning load. Since the air conditioner can be operated and canceled, it is possible to provide a control device for an air conditioner that can fully exert the air conditioning capacity of the air conditioner.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a control device for an air conditioner of the present invention.

FIG. 2 is a flow diagram showing control of heating operation of the control device for an air conditioner of the present invention.

FIG. 3 is a block diagram of a conventional air conditioner.

FIG. 4 is a flow chart showing control of heating operation of a conventional air conditioner.

FIG. 5 is an explanatory diagram showing codes of operating frequencies of the compressor.

[Explanation of symbols]

 1 Indoor Unit Control Unit 2 Indoor Heat Exchanger Temperature Sensor 3 Indoor Fan Motor 4 Room Temperature Sensor 5 Operation Unit 6 Temperature Setting Unit 7 Counter 8 Outdoor Unit Control Unit 9 Outdoor Heat Exchanger Temperature Sensor 10 Inverter Unit 11 Compressor 21 Indoor Unit Control Unit 28 Outdoor unit control unit

Claims (1)

[Claims] 1. A first temperature detecting means for detecting an outdoor heat exchanger temperature in an air conditioner control device comprising an inverter for controlling an operating frequency of a compressor in accordance with an air conditioning load during heating operation. Second temperature detecting means for detecting the temperature of the indoor heat exchanger and control means for controlling the operating frequency of the compressor are provided, and the temperatures of the first and second temperature detecting means are equal to or lower than a predetermined value. A control device for an air conditioner, wherein when the operation of the compressor by the control means continues at a maximum allowable operating frequency within the frequency limit for a predetermined period or longer, the frequency limit is released and the compressor is operated.