JPH10122674A - Method for controlling air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently perform a heating capacity by enhancing a first set value from a second time overload protecting operation after a first time overload protecting operation based on a first set value is finished. SOLUTION: High temperature and high pressure refrigerant discharged from a compressor 1 at the time of heating operation is fed through an indoor heat exchanger 3, a pressure reducing unit 4 utilizing a capillary tube, and an outdoor heat exchanger 5 in this order via a four-way valve 2, and circulated to the compressor 1 again via the valve 2. The controlling method comprises the steps of first overload protecting based on a first set value set to a lower value after a heating operation is started, and second overload protecting based on the other one set value set higher than the first set value even when the ambient temperature is, for example, 24 deg.C or higher. When the atmospheric temperature after the heating operation is started is, for example, 24 deg.C or lower, the first set value is raised from the first time. Thus, heating capacity can be sufficiently performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a control method for a heating operation of an air conditioner.

[0002]

2. Description of the Related Art An air conditioner is composed of an indoor unit and an outdoor unit. The indoor unit includes an indoor heat exchanger, an indoor blower for sending out the air heat exchanged by the indoor heat exchanger, and an indoor heat exchanger. Two temperature sensors and the like for detecting the intermediate temperature and the room temperature of the exchanger are provided, and one of the outdoor units has an outdoor heat exchanger and an outdoor blower that sends out the air exchanged by the outdoor heat exchanger to the outside. And a non-variable speed compressor and the like.
By the way, in the heating operation of the air conditioner configured as described above, when the outside air temperature increases or the room temperature increases, the temperature of the indoor heat exchanger increases, and the high pressure of the refrigeration cycle and the input current of the compressor. Rises beyond the specified value, and a so-called overload state is caused.

Therefore, in a conventional air conditioner, as shown in FIG.
When the temperature rises to 0 ° C. (this is a first set value), the operation of the outdoor blower is stopped (steps ST1 and ST2), and the temperature rises to a second set value (eg, 60 ° C.) higher than the first set value Then, the compressor is stopped for 3 minutes (steps ST3 and S3).
T4), and protects the compressor from an overload condition. Further, when the intermediate temperature of the indoor heat exchanger becomes lower than the first set value, for example, 48 ° C. or lower, the operation of the outdoor blower is restarted (steps ST5 and ST6).

[0004]

However, since the above-mentioned temperature sensor cannot quickly follow a sudden change in temperature on the other side, the intermediate temperature of the indoor heat exchanger which rapidly rises at the start of the heating operation can be quickly and quickly measured. It cannot be detected accurately, and the detected value becomes lower than the actual temperature, and the operation of overload protection is delayed. Therefore, in the conventional air conditioner, the above-described first set value (overload protection operation start temperature) is set to be lower. However, in the air conditioner in which the overload protection operation start temperature is set at such a low value, even if the air conditioner is effective for overload protection at the time of starting the heating operation, the overload protection operation is performed more quickly than necessary in the subsequent operation. Therefore, there is a problem that the room temperature is stabilized at a low level and the heating capacity cannot be sufficiently exhibited. Therefore, an object of the present invention is to provide a control method of an air conditioner that can solve this problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an indoor heat exchanger and an indoor blower for sending air heat-exchanged by the indoor heat exchanger to a room. And an indoor unit having a plurality of temperature sensors and the like for detecting an intermediate temperature and a room temperature of the indoor heat exchanger, an outdoor heat exchanger, and an outdoor unit including a non-variable speed compressor and an outdoor blower. When the intermediate temperature of the indoor heat exchanger during the heating operation rises to the first set value, the operation of the outdoor blower is stopped, and when the intermediate temperature rises to the second set value higher than the first set value, the operation of the compressor starts. In the air conditioner in which the operation is stopped for a predetermined time to protect the compressor from an overload state, after the heating operation is started, after the first overload protection operation based on the first set value is completed. From the second overload protection operation to the first setting It will be to increase the value.

[0006] When the room temperature at the start of the heating operation is equal to or lower than a predetermined value, the first set value is set higher from the beginning. Further, the first overload protection operation is stored until the end of the heating operation. Further, when the intermediate temperature of the indoor heat exchanger falls below a predetermined value by the overload protection operation based on the first set value, the operation of the outdoor blower is restarted. In the overload protection operation when the first set value is set higher, the intermediate temperature of the indoor heat exchanger, which is a reference temperature for restarting the operation of the outdoor blower, is set higher.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the control method of the present invention,
In the first overload protection after the heating operation is started, the first overload protection is performed based on the first set value which is set lower as in the related art, and 2
From the first time, even if the room temperature is, for example, 24 ° C. or more, it is performed based on another set value higher than the first set value,
In addition, when the room temperature at the start of the heating operation is, for example, 24 ° C. or lower, the first set value is set to be high from the beginning, so that the heating capacity can be sufficiently exhibited. Also, the first
When the intermediate temperature of the indoor heat exchanger falls to, for example, 48 ° C. or less by the overload protection operation based on the set value of the above, the operation of the outdoor blower is restarted, but the overload protection when the first set value is set higher In operation, the intermediate temperature of the indoor heat exchanger, which is the reference temperature for restarting the operation of the outdoor blower, is set higher. When the intermediate temperature of the indoor heat exchanger exceeds a second set value (for example, 60 ° C.), the compressor is stopped for a predetermined time (for example, 3 minutes) as in the related art.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a basic refrigeration cycle of an air conditioner and a part related to the present invention in a control system thereof. In the heating operation, a high-temperature and high-pressure refrigerant discharged from a compressor 1 passes through a four-way valve 2 in a room. The heat flows through the heat exchanger 3, the pressure reducing device 4 using a capillary tube or the like, and the outdoor heat exchanger 5, and circulates again to the compressor 1 via the four-way valve 2. The outdoor unit is provided with an outdoor unit control unit 7 for controlling the compressor 1, the four-way valve 2, the outdoor blower 6, etc. The other indoor unit includes an indoor blower 8 and a wind direction adjusting device (not shown). An indoor unit controller 9 for controlling is provided. The indoor unit controller 9 includes information on the room temperature detected by the temperature sensor 10 and information on the intermediate temperature of the indoor heat exchanger 3 detected by the temperature sensor 11. Is input, and the overload protection of the compressor 1 described below is performed based on the information.

Hereinafter, the control operation of overload protection during the heating operation will be described with reference to the flowchart of FIG. When the heating operation is started, in step ST1, it is determined whether or not there is stored information of the stop of the outdoor blower 6 due to the first overload protection. If there is no stored information, the process proceeds to step ST2, and if there is stored information, the process proceeds to step ST9. In step ST2, the room temperature is determined. If the room temperature is 24 ° C. or higher, the process proceeds to step ST3. If the room temperature is 24 ° C. or lower, the process proceeds to step ST9. In step ST3, it is determined whether or not the intermediate temperature of the indoor heat exchanger 3 has become equal to or higher than the first set value of 50 ° C.
If the temperature exceeds ° C, the process proceeds to step ST4, and the operation of the outdoor blower 6 is stopped. In step ST5, it is determined whether or not the intermediate temperature of the indoor heat exchanger 3 has become equal to or higher than the second set value of 60 ° C.

If it is determined in step ST5 that the intermediate temperature of the indoor heat exchanger 3 exceeds 60 ° C., the operation of the compressor 1 is reduced to 3 in order to protect the compressor 1 from overload in step ST6. However, if it is determined in step ST5 that the intermediate temperature of the indoor heat exchanger 3 is 60 ° C. or less, the intermediate temperature of the indoor heat exchanger 3 is determined again in step ST7. If the intermediate temperature has dropped to 48 ° C. or lower, the operation of the outdoor blower 6 is restarted in step ST8;
The stopped state of the outdoor blower 6 is continued until the temperature becomes lower than or equal to ° C.

Also, as described at the beginning, step S
In the determination at T1, when stop information of the outdoor blower 6 due to the first overload protection is recognized, or when the room temperature is equal to or lower than 24 ° C. even if the stop information is not recognized, step ST is performed.
In step ST9, the intermediate temperature of the indoor heat exchanger 3 is determined using another set value (56 ° C.) higher than the first set value (50 ° C.) used in step ST3. When the intermediate temperature exceeds 56 ° C., the process proceeds to step ST10, and the operation of the outdoor blower 6 is stopped to protect the compressor 1 from an overload state.
In the next step ST11, the same determination as in step ST5 is made, and if the intermediate temperature of the indoor heat exchanger 3 exceeds 60 ° C., the process proceeds to step ST6, and the operation of the compressor 1 is switched to 3
Stopped for a minute. If it is determined in step ST12 that the intermediate temperature of the indoor heat exchanger 3 has dropped to 52 ° C. or lower, the process proceeds to step ST8, and the operation of the outdoor blower 6 is restarted.

As described above, in this embodiment, the overload protection temperature at the start of the heating operation is set to be low as in the conventional case, and the intermediate value of the indoor heat exchanger 3 when the outdoor blower is stopped once by this set value. Since the temperature sensor 11 for detecting the temperature is also warm, the temperature can be detected following a slight temperature change. In the present embodiment, such a characteristic of the temperature sensor 11 is used to increase the set value in the second and subsequent overload protections. If the room temperature at the start of the heating operation is equal to or less than a predetermined value, Since the set value of the overload protection is increased from the beginning, the heating capacity can be sufficiently exhibited.

[0013]

According to the air conditioner having the control function as described above, the heating capacity of the air conditioner can be reduced without replacing the temperature sensor with a more expensive one having a higher performance. It is possible to make full use of it, and it is possible to keep the input current within the specified value even without the input current detecting means, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a refrigeration cycle of an air conditioner according to the present invention and a control system thereof.

FIG. 2 is a flowchart illustrating an example of a control operation according to the present invention.

FIG. 3 is a flowchart showing a conventional control operation example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Decompression device 5 Outdoor heat exchanger 6 Outdoor blower 7 Outdoor unit control unit 8 Indoor blower 9 Indoor unit control unit 10 Temperature sensor 11 Temperature sensor

Claims (5)

[Claims] 1. An indoor heat exchanger, an indoor blower for sending air exchanged by the indoor heat exchanger into a room, a plurality of temperature sensors for detecting an intermediate temperature and a room temperature of the indoor heat exchanger, and the like. An indoor unit equipped with an outdoor heat exchanger, an outdoor unit equipped with a non-variable speed compressor and an outdoor blower, etc., and the intermediate temperature of the indoor heat exchanger during the heating operation reaches a first set value. When it rises, the operation of the outdoor blower is stopped, and when it rises to a second set value higher than the first set value, the operation of the compressor is stopped for a predetermined time to protect the compressor from an overload state. In the air conditioner, after the heating operation is started, the first overload protection operation based on the first set value is completed, and then the first set value is increased from the second overload protection operation. A method for controlling an air conditioner, comprising: 2. The control method for an air conditioner according to claim 1, wherein when the room temperature at the start of the heating operation is equal to or lower than a predetermined value, the first set value is set higher from the beginning. 3. The air conditioner control method according to claim 1, wherein the first overload protection operation is stored until the end of the heating operation. 4. The operation of the outdoor blower is resumed when the intermediate temperature of the indoor heat exchanger falls below a predetermined value by an overload protection operation based on the first set value. 2. The method for controlling an air conditioner according to claim 1. 5. In the overload protection operation when the first set value is set higher, an intermediate temperature of the indoor heat exchanger, which is a reference temperature for restarting the operation of the outdoor blower, is set higher. The method for controlling an air conditioner according to claim 1.