KR100697411B1 - Control method of the invert compressor of a multi-type air conditioner - Google Patents

Abstract

The present invention relates to a method for controlling preheating operation of an inverter compressor of a multi-type air conditioner. The method includes: determining whether an environment in which the inverter compressor is to be preheated, and dividing the measured outdoor temperature by sections, and then changing the time for each section. To perform the preheating operation at a low frequency. According to this, the preheating operation time is varied according to the outdoor temperature, and the inverter compressor operates at a low frequency during the preheating operation so that the preheating operation time can be adjusted appropriately according to the change of the outdoor temperature, and the abnormal noise generated during the preheating operation can be removed. have.

Air conditioner, inverter compressor, preheating operation, cryogenic, oil viscosity

Description

Control method of the invert compressor of a multi-type air conditioner

1 is a configuration diagram of a refrigerant cycle of a general multi-type air conditioner.

2 is a schematic configuration diagram for controlling the preheating operation of the inverter compressor of the air conditioner.

3 is a flowchart illustrating a method for controlling preheating operation of an inverter compressor of a multi-type air conditioner according to the present invention.

4 is a chart showing the preheating operation time according to the outdoor temperature.

5 is a graph showing a frequency change of the inverter compressor with time during the preheating operation.

6 is a graph showing a change in the opening degree of the electromagnetic expansion valve with time during preheating operation.

* Explanation of symbols for main parts of drawings *

100: control unit 110: heat sink temperature sensor

120: compressor discharge pipe temperature sensor 130: outdoor temperature sensor

140: inverter compressor 150: constant speed compressor

The present invention relates to a control method of a multi-type air conditioner, and more particularly, to a preheating operation control method of an inverter compressor of a multi-type air conditioner that preheats first to a low frequency for a predetermined time when the inverter compressor is to be driven in a state where the outdoor temperature is extremely low. It is about.

An air conditioner is a device that is arranged in a room, living room, office, or business store to adjust the temperature, humidity, cleanliness, and airflow of the air to maintain a comfortable indoor environment. It is divided into (seperate type or split type).

The integrated type and the separated type are functionally the same, but the integrated type integrates the functions of cooling and heat dissipation to install a hole in the wall of the house or hang the device on the window, and the separate type installs an indoor unit that performs cooling / heating on the indoor side. In addition, the outdoor unit installed the outdoor unit that performs the heat dissipation and compression function, and then connected the two separate devices by the refrigerant pipe.

In general, one outdoor unit is installed in correspondence with one indoor unit. However, in the case of a building having several rooms, several outdoor units must be purchased to correspond to the indoor unit installed in each room. Since each outdoor unit must have a certain area of space, it is not efficient in terms of space usage.

Therefore, the development of a multi-type air conditioner capable of cooling and heating several rooms at once by connecting several indoor units to one outdoor unit is actively progressing.

1 is a configuration diagram of a refrigerant cycle of a general multi-type air conditioner.

The multi-type air conditioner includes an indoor unit (10) having a plurality of indoor heat exchangers (11a, 11b, 11c) arranged in the room and performing cooling / heating functions, and an outdoor unit (1) arranged outdoors. .

The outdoor unit (1) has an inverter compressor (2) and a constant speed compressor (3) for compressing the refrigerant, an outdoor heat exchanger (5) for dissipating the compressed refrigerant, and the outdoor heat exchanger (5). And a cooling fan 6 arranged at the rear of the pump to promote heat dissipation of the refrigerant.

In the cooling operation, a main electromagnetic expansion valve 12 is provided downstream of the outdoor heat exchanger 5 along the flow direction of the refrigerant, and a refrigerant is provided at a downstream side of the main electromagnetic expansion valve 12. Sub solenoid expansion valves 13a, 13b, and 13c are provided to allow expansion under reduced pressure before they are introduced into 11b and 11c, respectively. First temperature sensors 15a, 15b, and 15c are provided to detect the temperature of the refrigerant discharged from 11a, 11b, and 11c.

Meanwhile, the constant speed compressor 3 and the inverter compressor 2 each have a compression capacity corresponding to half (50%) of the maximum air-conditioning load of the indoor unit 1, and each discharge side has a refrigerant having an outdoor heat exchanger 5. The second temperature sensing sensor 4 is joined to each other prior to the introduction of the second temperature sensor, and a second temperature sensor 4 is provided in the joining region so as to sense the temperature of the refrigerant compressed and discharged from the compressors 2 and 3.

Next, the cooling process of the multi-type air conditioner will be described.

The high temperature and high pressure gas refrigerant compressed by the compressors 2 and 3 is guided to the outdoor heat exchanger 5 by four sides (not shown), and then condensed in the process of passing through the outdoor heat exchanger 5 to obtain a high temperature and high pressure. Phase is changed by liquid refrigerant. The high temperature and high pressure liquid refrigerant from the outdoor heat exchanger (5) flows into the main electromagnetic expansion valve (12), and then passes through the sub solenoid expansion valves (13a, 13b, 13c) to a state of low temperature and low pressure, and then indoors. It flows into the heat exchangers 11a, 11b, 11c. At this time, the introduced refrigerant is converted into a gaseous refrigerant by evaporation, and guided to the suction side of the compressors 2 and 3 by four sides (not shown).

At this time, the refrigerant passing through the indoor heat exchangers (11a, 11b, 11c) takes heat away from the air in the room and evaporates, and thus the air conditioning space is repeatedly cooled and the temperature thereof decreases.

Compared to a general air conditioner using only one indoor unit connected to one outdoor unit, the above-described multi-type air conditioner can cool / heat several rooms at the same time by using one outdoor unit. It is advantageous.

On the other hand, when the multi-type air conditioner mentioned above is operated in a state where the outdoor temperature is extremely low, the rotor of the motor rotates while the viscosity of the oil inside the compressor is low, so that the frictional force inside the compressor is increased and frictional wear occurs. This may cause burnout of the compressor, which may result in the compressor becoming locked and not starting. Therefore, when the outdoor temperature is cryogenic, it is necessary to preheat the compressor to improve the oil viscosity therein before the compressor is normally driven.

In general, the preheating of the compressor is a process of controlling the AC power supplied to the coil of the compressor so that only the coil generates heat while the rotor of the compressor does not rotate. That is, by flowing an alternating current through the coil of the compressor so that the rotor of the inverter compressor does not rotate, only the coil generates heat in a state in which the compressor does not discharge the high temperature and high pressure refrigerant. Thus, the heat dissipated in the coil can increase the oil viscosity inside the compressor and consequently reduce friction to prevent wear.

However, in the above-described conventional case, since the compressor is preheated by driving the compressor at a high frequency, abnormal noise occurs due to the high frequency switching of the switching element driven by the inverter unit, which causes a problem of discomfort to the user.

SUMMARY OF THE INVENTION The present invention relates to a method for controlling preheating operation of an inverter compressor of a multi-type air conditioner capable of performing preheating of a compressor under appropriate conditions without generating noise due to high frequency switching.

In order to achieve the above object, a method for controlling preheating operation of an inverter compressor of a multi-type air conditioner according to the present invention includes an outdoor temperature sensor for measuring an outdoor temperature, a temperature sensor installed in a compressor discharge pipe, and a heat sink temperature sensor. The first step of measuring the outdoor temperature, the compressor discharge pipe temperature, and the heat sink temperature, and determining that the compressor preheating operation should be performed when each of the measured values is less than the temperature preset in the controller, and the determination of the first step. In the case of preheating operation by dividing the measured outdoor temperature by sections, the preheating operation is performed on the inverter compressor at a predetermined low frequency to reduce the noise generated during the preheating operation by varying the time for each section. It characterized in that it comprises a second step.

In the case of the present invention, in the second step, as the temperature section to which the measured outdoor temperature belongs is lowered, the preheating time for the inverter compressor is increased.
In addition, the present invention is characterized in that, during the preheating operation in the second step, the opening degree of the electromagnetic expansion valve for delivering the refrigerant discharged from the inverter compressor to the indoor unit is maintained at 70% of the target opening degree.
In the present invention, the low frequency is characterized in that about 15Hz.

Therefore, according to the present invention, the preheating operation time is changed according to the outdoor temperature, and the inverter compressor operates at a low frequency during the preheating operation so that the preheating operation time can be appropriately adjusted according to the change of the outdoor temperature, and abnormality occurred during the preheating operation. Noise can also be removed.

Hereinafter, with reference to the accompanying drawings, it will be described in detail the preheating operation control method of the inverter compressor of the multi-type air conditioner according to the present invention.

2 is a schematic configuration diagram for controlling the preheating operation of the inverter compressor of the air conditioner, and FIG. 3 is a flowchart illustrating a method of controlling the preheating operation of the inverter compressor of the multi-type air conditioner according to the present invention.

The air conditioner according to the present invention is an outdoor temperature sensor 130, a compressor discharge pipe temperature sensor 120, and a heat sink temperature sensor as a check means for determining whether to perform a preheating operation of the initial driving compressor. 110. At this time, the outdoor temperature sensor 130, the compressor discharge pipe temperature sensor 120 and the heat sink temperature sensor 110 is electrically connected to the control unit 100 of the air conditioner. The controller 100 controls the driving of the inverter compressor 140 and the constant speed compressor 150 after analyzing the values read from the temperature sensors.

On the other hand, when the outdoor temperature is cryogenic, a process of preheating the compressor is necessary to improve the oil viscosity therein before the compressor is normally driven.

According to the present invention, after measuring the outdoor temperature, the compressor discharge pipe temperature, and the heat sink temperature before operating the compressor normally, if each of the measured values is less than the temperature preset in the controller, the preheating operation is first performed before the normal compressor operation. It is determined that the environment should be driven to drive the compressor in the preheating operation mode (mode).

At this time, after dividing the measured outdoor temperature by sections, the preheating operation time is adjusted differently for each section. For example, when the outdoor temperature is a "ga" section of more than -5 ℃ and less than 0 ℃, "A" minutes, for example about If the preheating operation is performed for about 1 minute and 30 seconds, and the "I" section having an outdoor temperature of more than -10 ° C and less than -5 ° C, perform a "B" minute, for example, about 3 minutes, and the outdoor temperature is-. In the case of the "multi" section that is less than 10 DEG C, preheating operation is performed for "C" minutes, for example, about 5 minutes. This is because the oil viscosity inside the compressor is lower as the outdoor temperature becomes a cryogenic state, and thus, it is necessary to perform more preheating operation in order to improve the oil viscosity to perform the normal operation of the compressor without difficulty.

On the other hand, the frequency of the inverter compressor during the preheating operation is controlled to a low frequency of about 15 Hz, for example. This is to remove the conventional noise generated during the preheating operation, and the present invention can remove the conventional abnormal noise caused by switching the switching element driven in the inverter at high frequency by preheating the inverter compressor at low frequency. have.

At this time, in the conventional case, there was no refrigerant discharged from the compressor during the preheating operation by performing the preheating operation in a state in which the rotor of the compressor was not moved, but in the case of the present invention, the preheating operation was performed by slowly moving the rotor of the compressor. By performing, a small amount of refrigerant is discharged unlike in the prior art. Therefore, in the present invention, the electromagnetic expansion valve LEV is smaller than the target opening degree, for example, about 70% (ie, the target opening degree * 0.7) to open the small amount of refrigerant discharged during the preheating operation to the indoor unit.

Next, with reference to FIG. 3, the preheating operation control method of the compressor by this invention is demonstrated in more detail.

When the air conditioner starts operation by the user operating the key input unit (not shown) of the air conditioner (step S100), the controller of the air conditioner (100 in FIG. 2) is an outdoor temperature sensor (130 in FIG. 2) and the compressor. The values measured by the discharge pipe temperature sensor (120 in FIG. 2) and the heat sink temperature sensor (110 in FIG. 2) are started to be read.

Subsequently, the controller (100 of FIG. 2) checks whether the temperature values read from the temperature sensors are less than the predetermined temperature values T1 ° C, T2 ° C and T3 ° C, respectively, and then the outdoor temperature, the compressor discharge pipe temperature, and the like. When it is confirmed that the heat sink temperature is less than T1 ° C, T2 ° C and T3 ° C, respectively, it is determined that the air conditioner is an environment in which the air conditioner should perform a preheating operation, and the compressor is placed in a preheating operation mode (step S110). At this time, according to one embodiment of the present invention, the T1 ℃, T2 ℃ and T3 ℃ are each 0 ℃.

Subsequently, the controller (100 in FIG. 2) determines that the outdoor temperature value measured by the outdoor temperature sensor is in the "ga" section, for example, a range of -5 ° C or more and less than 0 ° C (step S120), and the inverter compressor (Fig. 2). 140) is preheated to a low frequency such as 15 Hz for "A" minute, for example, 1 minute 30 seconds (step S130). At this time, while the inverter compressor is preheated to the low frequency, the electromagnetic expansion valve (LEV) is opened to an opening degree lower than the target opening degree, for example, 'target opening degree * 0.7'. This is to introduce a smaller amount of refrigerant into the indoor unit than the target amount discharged during the preheating operation.

Subsequently, when the preheating operation is performed for “A” minutes in step S130, the controller (100 of FIG. 2) performs the start operation for normal driving after finishing the preheating operation of the compressor (S140).

On the other hand, if it is determined in step S120 that the outdoor temperature value is not in the "A" section, the control unit (100 in Figure 2) again the outdoor temperature value is "B" section, for example, -10 ℃ or more-less than -5 ℃. After confirming that it is in the section, if it is determined that it is within the "B" section (step S150), the inverter compressor is preheated to a low frequency, such as 15Hz for "B" minutes, for example 3 minutes (step S160). At this time, during the preheating operation, the electronic expansion valve (LEV) is opened at an opening degree lower than the target opening degree as in step S130.

Subsequently, if it is determined in step S150 that the outdoor temperature value is not in the "I" section, the controller (100 in FIG. 2) indicates that the outdoor temperature value is in a "multi" section, for example, a section below -10 ° C. In operation S170, the inverter compressor is preheated to a low frequency for "C" minute, for example, 5 minutes (step S180). At this time, the low frequency is about 15Hz as in the steps S130 and S160, the opening degree of the electronic expansion valve (LEV) during the preheating operation is also lower than the target opening as described above.

Finally, when the preheating operation is performed for "B" minute and "C" minute in step S160 and step S180, respectively, the controller (100 of FIG. 2) ends the preheating operation of the compressor and starts the start operation for normal driving. Perform (S140 step).

Therefore, according to the present invention, the preheating operation time is changed according to the outdoor temperature, and the inverter compressor operates at a low frequency during the preheating operation so that the preheating operation time can be appropriately adjusted according to the change of the outdoor temperature, and abnormality occurred during the preheating operation. Noise can also be removed.

4 is a diagram illustrating preheating operation time according to outdoor temperature, FIG. 5 is a graph illustrating a frequency change of an inverter compressor according to time during preheating operation, and FIG. 6 is a change in opening degree of an electronic expansion valve according to time during preheating operation. Is a graph.

According to FIG. 4, the preheating operation of the inverter compressor according to the present invention is performed for 1 minute and 30 seconds when the outdoor temperature is in the "ga" section of -5 ° C. or more and less than 0 ° C., and is -10 ° C. or more and less than -5 ° C. It can be seen that it is performed for 3 minutes when in the "B" section, and 5 minutes when in the "C" section below -10 ° C.

Meanwhile, in FIG. 5, the graphs (a), (b) and (c) show the frequency change of the inverter compressor according to the time when the outdoor temperature is in the "a" section, the "b" section, and the "multi" section, respectively. 6, the graphs (a), (b) and (c) show the electronic expansion with time when the outdoor temperature is in the "a" section, the "b" section, and the "multi" section, respectively. The opening degree of the valve is shown.

5 and 6, the operating frequency of the inverter compressor is a low frequency of about 15 Hz at the time of preheating operation, but after the end of the preheating operation, the operating frequency is changed to a frequency suitable for the starting operation. The opening degree is about 70% of the target opening degree (target opening degree * 0.7) during the preheating operation, but the opening degree is changed to the opening degree suitable for the starting operation from the start operation after the end of the preheating operation. The opening degree of the electromagnetic expansion valve is smaller than the target opening degree because the amount of refrigerant discharged from the compressor during the preheating operation is significantly smaller than that of the normal operation of the compressor. Therefore, the opening degree of the electromagnetic expansion valve is not fixed to the value of the mentioned target opening degree * 0.7, of course, can be appropriately changed according to the amount of the refrigerant discharged from the compressor.

According to the method of controlling the preheating operation of the inverter compressor of the multi-type air conditioner according to the present invention, the inverter compressor operates at a low frequency during the preheating operation. Noise can be removed.

In addition, by dividing the outdoor temperature by sections, the preheating operation time may be appropriately adjusted according to the change of the outdoor temperature by changing the preheating operation time according to each section.

Claims (4)

After measuring the outdoor temperature, the compressor discharge pipe temperature and the heat sink temperature by using the outdoor temperature sensor for measuring the outdoor temperature, the temperature sensor installed in the compressor discharge pipe, and the heat sink temperature sensor, the respective measured values were controlled. The first step of determining that the compressor needs to be preheated when the temperature is lower than the preset temperature. In the preheating operation according to the determination of the first step, after dividing the measured outdoor temperature by sections, the inverter compressor is operated at a predetermined low frequency to reduce the noise generated during the preheating operation by varying the time for each section. Preheating operation control method of the inverter compressor of the multi-type air conditioner, characterized in that it comprises a second step of performing a preheating operation. The method of claim 1, In the second step, the preheating operation control method of the inverter compressor of the multi-type air conditioner, characterized in that the lower the temperature range to which the measured outdoor temperature belongs. The method of claim 1, During the preheating operation in the second step, the opening degree of the electromagnetic expansion valve for delivering the refrigerant discharged from the inverter compressor to the indoor unit is opened and maintained at 70% of the target opening degree of the inverter compressor of the multi-type air conditioner Preheating operation control method. The method according to any one of claims 1 to 3, The low frequency is a pre-heating operation control method of the inverter compressor of the multi-type air conditioner, characterized in that about 15Hz.

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