JP2020085316A - Control device for air conditioner, air conditioner, control method for air conditioner, and control program for air conditioner - Google Patents

Abstract

To provide a control device for an air conditioner which performs control for changing a current value to flow to a motor coil on the basis of an outside air temperature, the air conditioner, a control method for the air conditioner, and a control program for the air conditioner.SOLUTION: The present invention relates to a control device 70 for an air conditioner 1 comprising an outdoor unit 2 including a compressor 10. The outdoor unit 2 includes an outside air temperature sensor 50 which is provided therein and detects an outside air temperature. The compressor 10 includes a motor coil 40 of a motor for driving the compressor 10 therein. The control device performs current control for controlling a current value in such a manner that the current value to flow to the motor coil 40 is made into a first current value in a case where the outside air temperature detected by the outside air temperature sensor 50 is equal to or lower than -2°C and higher than a first outside air temperature threshold during stop of the air conditioner 1, and that the current value to flow to the motor coil 40 is made into a second current value which is greater than the first current value in a case where the outside air temperature is equal to or lower than the first outside air temperature threshold.SELECTED DRAWING: Figure 1

Description

The present invention relates to an air conditioner control device, an air conditioner, an air conditioner control method, and an air conditioner control program.

In the refrigeration cycle of the air conditioner, refrigerant and lubricating oil are enclosed in a closed circuit. For example, if the compressor is stopped when the outside air temperature is low, the temperature of the compressor arranged in the outdoor unit will drop and the refrigerant will be in a liquid state (liquid stagnation), and the refrigerant will dissolve in the lubricating oil inside the compressor. The viscosity of the lubricating oil decreases. If the compressor is started in this state, the lubricating oil is discharged together with the refrigerant, the lubricating oil becomes insufficient, and the viscosity of the lubricating oil decreases, resulting in defective formation of the oil film or liquid compression, which damages the compressor. There is a risk.

In order to prevent this, before the heating operation is started while the operation of the air conditioner is stopped, a current is passed from the inverter to the motor coil of the compressor to preheat the inside of the compressor. By preheating the inside of the compressor to evaporate the refrigerant dissolved in the lubricating oil, it is possible to improve the startup performance of the heating operation at low temperatures.
For example, Patent Documents 1 to 6 disclose that an electric current is passed through a motor coil when the outside air temperature is lower than a predetermined temperature.

JP-A-62-33242 JP-A-63-294461 JP-A-3-59358 JP-A-5-34024 JP, 11-83208, A JP-A-2000-292014

However, in the inventions disclosed in the above Patent Documents 1 to 6, the predetermined temperature of the outside air temperature that triggers the control is one value, and therefore the current flowing through the motor coil even when the outside air temperature is lower than expected. Was constant, and there was a problem that preheating might be insufficient. Further, if the current flowing through the motor coil is increased on the assumption that the outside air temperature is low, when the outside air temperature is higher than expected, excess preheating is performed, an unnecessary current flows, and the amount of electric power increases. If the surplus current continues to flow, the motor coil may exceed the usage limit temperature, which may lead to damage to the motor coil and damage to the compressor.

The present disclosure has been made in view of such circumstances, and is a control device for an air conditioner, an air conditioner, and a control for an air conditioner that performs control for changing a current value flowing to a motor coil based on an outside air temperature. An object of the present invention is to provide a method and a control program for an air conditioner.

In order to solve the above-mentioned problems, the control device for an air conditioner, the air conditioner, the method for controlling an air conditioner, and the control program for an air conditioner according to the present disclosure employ the following means.
A control device for an air conditioner according to an aspect of some embodiments of the present disclosure is a control device for an air conditioner including an outdoor unit including a compressor, and the outdoor unit is provided inside thereof. An outside air temperature sensor for detecting an outside air temperature is provided, the compressor is provided with a motor coil of a motor for driving the compressor, and the outside air temperature sensor detects the outside air temperature while the air conditioner is stopped. When the temperature is less than or equal to minus 2° C. and higher than the first outside air temperature threshold, the current value to be passed through the motor coil is the first current value, and when the outside air temperature is below the first outside air temperature threshold, the current is passed through the motor coil. The current control for controlling the current value is performed so that the current value becomes the second current value larger than the first current value.

According to this aspect, based on the outside air temperature detected by the outside air temperature sensor provided inside the outdoor unit, the current control for controlling the value of the current flowing to the motor coil provided inside the compressor is performed. The temperature of the motor coil can be changed according to the change.

While the air conditioner is stopped, if the outdoor temperature in which the outdoor unit is installed is low, the liquefied refrigerant may dissolve and accumulate in the lubricating oil. Therefore, based on the outside air temperature detected by the outside air temperature sensor, a current is supplied to the motor coil provided inside the compressor, and when the outside air temperature is low, the current value to the motor coil is increased to preheat the refrigerant. It can be evaporated, and when the outside air temperature is high, the current value to the motor coil can be lowered so as to prevent extra preheating. In this way, appropriate preheating can be performed without excess or deficiency, and the start-up during heating operation can be improved. Further, since proper preheating is performed, an unnecessary current does not flow, so it is possible to suppress the amount of electric power, save energy, and reduce cost.

When the outside air temperature detected by the outside air temperature sensor is less than or equal to −2° C. and greater than the first outside air temperature threshold value, the current value flowing to the motor coil is the first current value, and the outside air temperature is less than or equal to the first outside air temperature threshold value. Since the current value is set to the second current value which is larger than the first current value, the current value matched to the outside air temperature can be passed. Further, when the outside air temperature is equal to or lower than the first outside air temperature threshold value, the current value is further increased. Therefore, when the outside air temperature is low, it is possible to prevent insufficient preheating and prevent refrigerant stagnation.

In the above aspect, when the current value is the second current value, when the outside air temperature detected by the outside air temperature sensor exceeds a temperature obtained by adding 2° C. to the first outside air temperature threshold value, the current value is set to the first current value. It may be changed to a current value.

According to this aspect, when the current value is the second current value and the outside air temperature detected by the outside air temperature sensor exceeds the first outside air temperature threshold value +2° C., the current value passed to the motor coil is changed to the first current value. Therefore, even if the outside air temperature is initially equal to or lower than the first outside air temperature threshold value, preheating may be small when the outside air temperature rises, so that the current value can be set according to the outside air temperature. Further, since the control is performed with hysteresis, the current value does not cause hunting even if the outside air temperature is near the boundary value of the first outside air temperature threshold value.

In the above aspect, when the outside air temperature detected by the outside air temperature sensor is equal to or less than a second outside air temperature threshold value lower than the first outside air temperature threshold value, the current value is set to a third current value larger than the second current value value. You may.

According to this aspect, when the outside air temperature detected by the outside air temperature sensor is equal to or less than the second outside air temperature threshold value lower than the first outside air temperature threshold value, the current value is set to the third current value larger than the second current value value. When the outside air temperature is equal to or lower than the second lower outside air temperature threshold value, it is possible to prevent insufficient preheating and prevent refrigerant stagnation.

In the above aspect, when the current value is the third current value, and when the outside air temperature detected by the outside air temperature sensor exceeds a temperature obtained by adding 2° C. to the second outside air temperature threshold value, the current value is set to the second value. It may be changed to a current value.

According to this aspect, when the current value is the third current value and the outside air temperature detected by the outside air temperature sensor exceeds the second outside air temperature threshold value +2° C., the current value to be passed to the motor coil is changed to the second current value. Therefore, even if the outside air temperature is initially equal to or lower than the second outside air temperature threshold value, the preheating may be small when the outside air temperature rises, so that the current value can be set according to the outside air temperature. Further, since the control is performed with hysteresis, the current value does not cause hunting even when the outside air temperature is near the boundary value of the second outside air temperature threshold value.

In the above aspect, a temperature sensor that detects the discharge temperature of the refrigerant may be provided on the discharge side of the compressor, and the current control may be stopped when the discharge temperature is equal to or higher than the first discharge temperature threshold.

According to this aspect, the temperature sensor that detects the discharge temperature of the refrigerant is provided on the discharge side of the compressor, and when the discharge temperature is equal to or higher than the first discharge temperature threshold value, the current control is stopped. It is possible to prevent the temperature of the motor coil from rising excessively and prevent the motor coil and the compressor from being damaged due to excessive temperature rise. Further, since the control is performed based on the actual temperature of the refrigerant, the control can be performed in accordance with the actual situation, and the labor can be saved and the cost can be reduced without supplying an extra current.
Here, it is assumed that the first discharge temperature threshold corresponds to a temperature set so as not to exceed the use limit temperature of the motor coil, and is a refrigerant discharge temperature that protects the compressor.

In the above aspect, the current control may be started when the discharge temperature becomes equal to or lower than the second discharge temperature threshold value lower than the first discharge temperature threshold value while the current control is stopped.

According to this aspect, when the discharge temperature becomes equal to or lower than the second discharge temperature threshold value lower than the first discharge temperature threshold value while the current control is stopped, the current control is started, so that the current is supplied to the motor coil where the current control is stopped. If the refrigerant does not flow and the refrigerant is not heated, refrigerant stagnation may occur, but the refrigerant can be heated again while protecting the motor coil and the compressor. As a result, it is possible to prevent insufficient preheating, suppress the supply of the sleeping refrigerant, and prevent the compressor from being damaged. Moreover, the rise of the heat exchanger of the indoor unit can be improved.

In the above aspect, when the current value is the third current value and the discharge temperature is equal to or higher than the third discharge temperature threshold value lower than the second discharge temperature threshold value, the current value is set to the second current value. May be

According to this aspect, when the discharge temperature is equal to or higher than the third discharge temperature threshold value, the current value is set to the second current value. Therefore, based on the discharge temperature of the refrigerant increased by the preheating by the motor coil provided in the compressor, The current value can be changed. Since the control is performed based on the actual temperature of the refrigerant, the control can be performed according to the actual situation, and the labor can be saved and the cost can be reduced without supplying an extra current. Further, it is possible to improve the rise of the heat exchanger of the indoor unit during heating.
Here, it is assumed that the third discharge temperature threshold value is a discharge temperature threshold value that can be expected to improve at the time of startup of the heat exchanger of the indoor unit during the heating operation.

In the above aspect, when the current value is the second current value, the current value may be the first current value if the discharge temperature is equal to or higher than the second discharge temperature threshold.

According to this aspect, when the discharge temperature is equal to or higher than the second discharge temperature threshold, the current value of the motor coil is set to the first current value. Therefore, when the discharge temperature of the refrigerant further rises due to preheating by the motor coil, the current value Can be lowered to prevent excess current from flowing.

An air conditioner according to an aspect of some embodiments of the present disclosure includes the control device described in any of the above.

A method for controlling an air conditioner according to an aspect of some embodiments of the present disclosure is a method for controlling an air conditioner including an outdoor unit including a compressor, wherein the outdoor unit is provided inside thereof. An outside air temperature sensor for detecting an outside air temperature is provided, the compressor is provided with a motor coil of a motor for driving the compressor, and the outside air temperature sensor detects the outside air temperature while the air conditioner is stopped. When the temperature is less than or equal to minus 2° C. and higher than the first outside air temperature threshold, the current value to be passed through the motor coil is the first current value, and when the outside air temperature is below the first outside air temperature threshold, the current is passed through the motor coil. The method includes a step of controlling the current value so that the current value becomes a second current value larger than the first current value.

A control program applied to an air conditioner according to an aspect of some embodiments of the present disclosure is a control program applied to an air conditioner including an outdoor unit including a compressor, wherein the outdoor unit is An air temperature sensor provided inside the air temperature sensor for detecting the air temperature, the compressor having a motor coil of a motor for driving the compressor therein, and the air temperature is maintained while the air conditioner is stopped. When the outside air temperature detected by the sensor is −2° C. or less and is larger than the first outside air temperature threshold value, the current value flowing to the motor coil is set as a first current value, and when the outside air temperature is less than or equal to the first outside air temperature threshold value, There is a step of controlling the current value so that the current value flowing to the motor coil becomes a second current value larger than the first current value.

According to the present disclosure, when the outside air temperature is higher than the threshold value, the current value to be passed to the motor coil is set to the first current value, and when the outside air temperature is below the threshold value, the second current value is set to be larger than the first current value. The appropriate current value can be passed to perform appropriate preheating.

It is the schematic block diagram which showed the one aspect at the time of heating operation of the air conditioning apparatus which concerns on some embodiment. It is a graph which showed the relationship between the outside air temperature and the current value in the air harmony device concerning some embodiments. It is a graph which showed the relationship between the outside air temperature and the current value in the air harmony device concerning some embodiments.

Hereinafter, each embodiment of a control device for an air conditioner, an air conditioner, a method for controlling an air conditioner, and a control program for an air conditioner according to some embodiments of the present disclosure will be described with reference to the drawings. ..
FIG. 1 illustrates a schematic configuration of an aspect during a heating operation of a control device for an air conditioner, an air conditioner, a control method for an air conditioner, and a control program for an air conditioner according to some embodiments of the present disclosure. It is shown.
The air conditioner 1 has one outdoor unit 2 and one indoor unit 3 connected thereto.

The outdoor unit 2 includes an inverter-driven compressor 10 that compresses a refrigerant, an accumulator 19 that separates a liquid component from a refrigerant gas that is sucked into the compressor 10, and a gas component that is sucked into the compressor 10 side. An outdoor four-way switching valve 12 that switches the circulation direction and an outdoor heat exchanger 20 that exchanges heat between the refrigerant and the outside air are provided.
The above-described devices on the outdoor unit 2 side are sequentially connected via a refrigerant pipe 22 to form a known outdoor refrigerant circuit 23. Further, the outdoor unit 2 is provided with an outdoor fan (not shown) that blows outside air to the outdoor heat exchanger 20.

The outdoor unit 2 is provided with an outside air temperature sensor 50 that detects the outside air temperature inside. The outdoor air temperature sensor 50 is installed inside the outdoor unit 2 so as not to be affected by the temperature from each device of the outdoor unit 2 described above.

Inside the compressor 10 of the outdoor unit 2, a motor coil 40 of a motor that drives the compressor 10 is provided. Current is supplied to the motor coil 40 from the inverter.

The indoor unit 3 cools or heats the indoor air by exchanging heat with the refrigerant to provide indoor air conditioning, and an indoor fan (not shown) that circulates the indoor air through the indoor heat exchanger 30. ) And an indoor controller (not shown), and is connected to the outdoor unit 2.

Although FIG. 1 illustrates the case where one indoor unit 3 is installed, the number of installed units can be arbitrarily determined.

The control device 70 acquires the set temperature set by the indoor controller and the like, the indoor temperature, the outside air temperature detected by the outside air temperature sensor 50 installed in the outdoor unit 2, and the like, and determines the value of the current flowing through the motor coil 40. Control, switching control of the outdoor four-way switching valve 12, and the like are performed.
The control device 70 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions are stored in a storage medium or the like in the form of a program as an example, and the CPU reads the program into a RAM or the like to execute information processing/arithmetic processing. As a result, various functions are realized. The program is installed in a ROM or other storage medium in advance, provided in a state of being stored in a computer-readable storage medium, or delivered via wired or wireless communication means. Etc. may be applied. The computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

In the air conditioner 1 described above, the heating operation is performed as follows.
The high-temperature and high-pressure refrigerant gas compressed and discharged by the compressor 10 is circulated to the indoor unit 3 side via the outdoor four-way switching valve 12. This high-pressure gas refrigerant is led out from the outdoor unit 2 and introduced into the indoor unit 3 via the refrigerant pipe.

The high-temperature and high-pressure refrigerant gas introduced into the indoor unit 3 is heat-exchanged with the indoor air circulated by the indoor heat exchanger 30 via an indoor fan (not shown), and the indoor air heated thereby is indoors. It is blown out and used for heating. On the other hand, the refrigerant condensed and liquefied in the indoor heat exchanger 30 returns to the outdoor unit 2 through the refrigerant pipe.

The refrigerant returned to the outdoor unit 2 flows into the outdoor heat exchanger 20.
In the outdoor heat exchanger 20, the outside air blown from the outdoor fan and the refrigerant exchange heat with each other, and the refrigerant absorbs heat from the outside air to be evaporated and gasified. This refrigerant is introduced into the accumulator 19 from the outdoor heat exchanger 20 through the outdoor four-way switching valve 12. In the accumulator 19, the liquid component contained in the refrigerant gas is separated, and only the gas component is sucked into the compressor 10 and compressed again in the compressor 10. Heating operation is performed by repeating the above cycle.

When the air conditioner 1 stops operating when the outside air temperature is low, the compressor 10 also stops. The temperature of the compressor 10 arranged in the outdoor unit 2 decreases, the refrigerant becomes a liquid state (liquid stagnation), and the refrigerant dissolves in the lubricating oil inside the compressor 10, so that the viscosity of the lubricating oil decreases. When the air conditioner 1 starts operating and the compressor 10 is started in this state, the lubricating oil is discharged together with the refrigerant. There is a risk that the compressor 10 may be damaged due to insufficient oil film formation or liquid compression due to lack of lubricating oil in the compressor 10 and decrease in viscosity.

Therefore, in the present embodiment, the outside air temperature sensor 50 installed in the outdoor unit 2 detects the outside air temperature, and the current value to the motor coil 40 provided inside the compressor 10 is controlled based on the outside air temperature. The motor coil 40 generates heat when a current flows, and the amount of heat generation increases in proportion to the magnitude of the current. Preheating is applied to the compressor 10 by the heat generation of the motor coil 40. The refrigerant is heated, and the refrigerant that has been in the liquid state can be evaporated.

FIG. 2 is a graph showing the relationship between the outside air temperature and the current value in the air conditioner according to some embodiments of the present disclosure.
In the graph of FIG. 2, the vertical axis represents the current value (A) flowing through the motor coil 40, and the horizontal axis represents the outside air temperature (° C.) detected by the outside air temperature sensor 50.

As shown in FIG. 2, when the outside air temperature detected by the outside air temperature sensor 50 is higher than the first outside air temperature threshold value T1 (T1<−4° C.) and is −2° C. or less, the current value flowing to the motor coil 40. Is controlled to the first current value I1.

Further, when the outside air temperature is low and the outside air temperature detected by the outside air temperature sensor 50 is less than or equal to the first outside air temperature threshold value T1, the current value flowing to the motor coil 40 is controlled to the second current value I2 larger than the first current value. It

Here, when the outside air temperature further decreases, such as when installed in a cold region, the second outside air temperature threshold value T2 may be provided. In that case, the second outside air temperature threshold value T2 is set to a value lower than T1-2 (° C.). When the outside air temperature detected by the outside air temperature sensor 50 is higher than the second outside air temperature threshold value T2 and equal to or less than the first outside air temperature threshold value T1, the current value flowing to the motor coil 40 is controlled to the second current value I2. When the outside air temperature is equal to or lower than the second outside air temperature threshold value T2, the current value flowing through the motor coil 40 is controlled to the third current value I3 which is larger than the second current value I2.

The outside temperature fluctuates due to changes in the weather. Therefore, the value of the current flowing to the motor coil 40 is changed according to the outside air temperature detected by the outside air temperature sensor 50. When the outside air temperature falls, the above control is performed. If the same threshold value is used for control even when the outside air temperature rises, if the outside air temperature fluctuates near the first outside air temperature threshold value T1, for example, the current value is the first current value I1 and the second current value I2. May cause hunting between.
Therefore, T1+2 (° C.), which is a value larger than the first outside air temperature threshold value T1, is set, and when the current value is the second current value I2, the current value is switched from the second current value I2 to the first current value I1. In this case, it is used as a threshold. T1+2 (° C.) is a value set in consideration of the temperature change so that the current value does not switch even when the outside air temperature slightly changes and exceeds the first outside air temperature threshold value T1.
Similarly, for the second outside air temperature threshold value T2, T2+2 (° C.), which is a value larger than the second outside air temperature threshold value T2, is set, and when the current value is the third current value I3, the current value is set to the third current value. It is used as a threshold when switching from the value I3 to the second current value I2.

When the current value is the second current value I2, even if the outside air temperature detected by the outside air temperature sensor 50 becomes equal to or higher than the first outside air temperature threshold value T1, the current value remains the second current value I2.
Further, when the outside air temperature fluctuates and becomes T1+2 or more, control is performed to switch the current value from the second current value I2 to the first current value I1.

In the current control in which a current is supplied to the motor coil 40 to preheat the air conditioner 1 while the operation of the air conditioner 1 is stopped, the time from the stop of the operation of the air conditioner 1 to the start of the next operation is a predetermined time (for example, 48 hours). ) Is exceeded, control is stopped. Current control improves the startup at the start of the next heating operation, but if it stops for more than 48 hours, it may be a long-term stop (season change, etc.), and unnecessary preheating is performed. You can avoid it.

As described above, according to the air conditioner control device, the air conditioner, the air conditioner control method, and the air conditioner control program according to the present embodiment, the following operational effects are achieved.
Based on the outside air temperature detected by the outside air temperature sensor 50 provided inside the outdoor unit 2, the current control for controlling the value of the current flowing to the motor coil 40 provided inside the compressor 10 is performed. In addition, the temperature of the motor coil 40 can be changed.

While the air conditioner 1 is stopped, if the outdoor temperature in which the outdoor unit 2 is installed is low, the liquefied refrigerant may be dissolved and accumulated in the lubricating oil. Therefore, based on the outside air temperature detected by the outside air temperature sensor 50, a current is supplied to the motor coil 40 provided inside the compressor 10 to increase the current value to the motor coil 40 to preheat when the outside air temperature is low. It is possible to evaporate the refrigerant by performing the operation, and when the outside air temperature is high, it is possible to reduce the current value to the motor coil 40 and perform control so as not to perform extra preheating. In this way, appropriate preheating can be performed without excess or deficiency, and the start-up during heating operation can be improved. Further, since proper preheating is performed, unnecessary electric current does not flow, so it is possible to suppress the amount of electric power, save energy, and reduce cost.

When the outside air temperature detected by the outside air temperature sensor 50 is −2° C. or less and is larger than the first outside air temperature threshold value, the current value flowing to the motor coil 40 is set as the first current value, and the outside air temperature is below the first outside air temperature threshold value. In this case, the current value is set to the second current value that is larger than the first current value, so that the current value that matches the outside air temperature can be passed. Further, when the outside air temperature is equal to or lower than the first outside air temperature threshold value, the current value is further increased. Therefore, when the outside air temperature is low, it is possible to prevent insufficient preheating and prevent refrigerant stagnation.

Further, according to the present embodiment, when the current value is the second current value and the outside air temperature detected by the outside air temperature sensor 50 exceeds the first outside air temperature threshold value +2° C., the current value passed to the motor coil 40 is set to the first current value. Since the value is changed to a value, even if the outside air temperature is initially equal to or lower than the first outside air temperature threshold value, preheating may be small when the outside air temperature rises, so that the current value can be set according to the outside air temperature. Further, since the control is performed with hysteresis, the current value does not cause hunting even if the outside air temperature is near the boundary value of the first outside air temperature threshold value.

Further, according to the present embodiment, when the outside air temperature detected by the outside air temperature sensor 50 is equal to or lower than the second outside air temperature threshold value lower than the first outside air temperature, the current value is set to the third current value larger than the second current value. Therefore, when the outside air temperature is equal to or lower than the second lower outside air temperature threshold value, it is possible to prevent insufficient preheating and prevent refrigerant stagnation.

Further, according to the present embodiment, when the current value is the third current value and the outside air temperature detected by the outside air temperature sensor 50 exceeds the second outside air temperature threshold value +2° C., the current value passed to the motor coil 40 is changed to the second current value. Since the value is changed to a value, even if the outside air temperature is initially equal to or lower than the second outside air temperature threshold value, preheating may be small when the outside air temperature rises, so that the current value can be set according to the outside air temperature. Further, since the control is performed with hysteresis, the current value does not cause hunting even when the outside air temperature is near the boundary value of the second outside air temperature threshold value.

In the above-described embodiment, the current value is controlled based on the outside air temperature, but in the present embodiment, the current value is controlled based on the discharge temperature of the refrigerant of the compressor in addition to this. Since the other points are the same as those of the above-described embodiment, the same components are designated by the same reference numerals and the description thereof will be omitted.

FIG. 3 is a graph showing the relationship between the outside air temperature and the current value in the air conditioner according to some embodiments of the present disclosure.
In the graph of FIG. 3, the vertical axis represents the current value (A) flowing through the motor coil 40, and the horizontal axis represents the outside air temperature (° C.) detected by the outside air temperature sensor 50.

A temperature sensor 60 (see FIG. 1) that detects the discharge temperature of the refrigerant is provided on the discharge side of the compressor 10.
Since the temperature sensor 60 detects the discharge temperature of the refrigerant heated by the preheating of the motor coil 40, the temperature of the motor coil 40 can be estimated from the discharge temperature of the refrigerant.
The inventors have found that when the discharge temperature of the refrigerant is 25° C., the temperature of the motor coil 40 is about 100° C., which is close to the usage limit temperature at which the coil deteriorates. Further, it has been found that when the discharge temperature of the refrigerant is 10° C. or higher, the rise of the indoor heat exchanger 30 of the indoor unit 3 during heating is improved, and even if the discharge temperature exceeds 10° C., the improvement is almost the same. Obtained.
Therefore, the temperature for protecting the compressor 10 without exceeding the usage limit temperature at which the motor coil 40 deteriorates is set to the first discharge temperature threshold value Td1, and the lower limit value of the temperature at which the rise of the indoor heat exchanger 30 of the indoor unit 3 is improved. An arbitrary temperature that is higher than the third discharge temperature threshold Td3 and the third discharge temperature threshold Td3 and lower than the first discharge temperature threshold Td1 is set as the second discharge temperature threshold Td2.
In the case of the compressor 10 used in this embodiment, when the first discharge temperature threshold Td1 is 25° C. and the third discharge temperature threshold Td3 is 10° C., the second discharge temperature threshold Td2 is, for example, 15° C. .. The respective discharge temperature thresholds have different values depending on the model and performance of the compressor 10.

When the discharge temperature of the refrigerant detected by the temperature sensor 60 is equal to or higher than the first discharge temperature threshold value Td1, the motor coil 40 exceeds the usage limit temperature and the motor coil 40 is damaged when the current is continuously supplied to the motor coil 40 any more. As a result, the compressor 10 may be damaged, and in order to prevent the damage, the current control is stopped and the current to the motor coil 40 is stopped.

If the current does not flow to the motor coil 40 and the preheating is not performed, the temperature of the refrigerant may decrease and the refrigerant may stagnate. Further, at the start of the operation of the air conditioner 1, the preheated refrigerant does not flow into the indoor heat exchanger 30 of the indoor unit 3, and the heating capacity rises slowly when the heating operation is started from the stopped state.
Therefore, if the discharge temperature of the refrigerant becomes equal to or lower than the second discharge temperature threshold value while the current control is stopped, the current control is restarted so that the discharge temperature of the refrigerant does not drop too much.

Further, as described above, when the discharge temperature of the refrigerant from the compressor 10 detected by the temperature sensor 60 exceeds the third discharge temperature threshold Td3, the improvement in the rise of the indoor heat exchanger 30 of the indoor unit 3 is almost the same. Further, since it is considered that the refrigerant has been sufficiently warmed by the preheating of the motor coil 40, the value of the current flowing to the motor coil 40 will be reduced.
In the present embodiment, when the current value flowing to the motor coil 40 is the third current value I3 and the refrigerant discharge temperature is equal to or higher than the third discharge temperature threshold Td3, the current value is set to the second value regardless of the value of the outside air temperature. The current value is switched to I2.
Further, when the current value flowing to the motor coil 40 is the second current value I2 and the discharge temperature of the refrigerant is equal to or higher than the second discharge temperature threshold Td2 which is higher than the third discharge temperature threshold, the refrigerant is warmer. Therefore, the current value is switched to the first current value I1 regardless of the value of the outside air temperature.

As described above, according to the air conditioner control device, the air conditioner, the air conditioner control method, and the air conditioner control program according to the present embodiment, the following operational effects are achieved.
When the discharge temperature of the refrigerant detected by the temperature sensor 60 is equal to or higher than the first discharge temperature threshold value, the current control is stopped. Therefore, the temperature of the motor coil 40 is monitored based on the discharge temperature of the refrigerant to determine the temperature of the motor coil 40. It is possible to prevent the motor coil 40 and the compressor 10 from being damaged due to excessive rise in the temperature.
Here, it is assumed that the first discharge temperature threshold corresponds to a temperature set so as not to exceed the usage limit temperature of the motor coil 40 and is a refrigerant discharge temperature that protects the compressor 10.

Further, according to the present embodiment, when the discharge temperature of the refrigerant detected by the temperature sensor 60 while the current control is stopped becomes equal to or lower than the second discharge temperature threshold value lower than the first discharge temperature threshold value, the current control is started. Refrigerant stagnation may occur if current does not flow in the motor coil 40 for which current control is stopped and the refrigerant is not heated, but the refrigerant is heated again while protecting the motor coil 40 and the compressor 10. It can be performed. As a result, it is possible to prevent insufficient preheating, suppress the supply of the sleeping refrigerant, and prevent the compressor 10 from being damaged. Moreover, the rising of the indoor heat exchanger 30 of the indoor unit 3 can be improved.

Further, according to the present embodiment, when the refrigerant discharge temperature detected by the temperature sensor 60 is equal to or higher than the third discharge temperature threshold value, the current value is set to the second current value. The current value can be changed based on the discharge temperature of the refrigerant increased by the preheating by 40. Since the control is performed based on the actual temperature of the refrigerant, the control can be performed according to the actual situation, and the labor can be saved and the cost can be reduced without supplying an extra current. Further, the rising of the indoor heat exchanger 30 of the indoor unit 3 during heating can be improved.
Here, it is assumed that the third discharge temperature threshold value is a discharge temperature threshold value that can be expected to improve when the indoor heat exchanger 30 of the indoor unit 3 starts up during heating operation.

Further, according to the present embodiment, when the discharge temperature of the refrigerant detected by the temperature sensor 60 is equal to or higher than the second discharge temperature threshold, the current value of the motor coil 40 is set to the first current value, so that the preheating by the motor coil 40 is performed. When the discharge temperature of the refrigerant further rises, the current value can be reduced to prevent excess current from flowing.

As described above, some embodiments of the present disclosure have been described in detail with reference to the drawings, but a specific configuration is not limited to this embodiment. For example, in each of the above-described embodiments, two outside air temperature thresholds are set and three discharge temperature thresholds are set, but three or more may be set respectively. In that case, four or more current values may be set.

Further, in some embodiments of the present disclosure, the air conditioner 1 is configured to include one outdoor unit 2 and one indoor unit 3, but a multi-type air conditioner including a plurality of indoor units 3 is described. It may be applied to a device.

Further, the control device 70 may be provided outside the air conditioner 1, and may be provided inside the outdoor unit 2 or inside the indoor unit 3.

1 Air Conditioner 2 Outdoor Unit 3 Indoor Unit 10 Compressor 12 Outdoor Four-way Switching Valve 19 Accumulator 20 Outdoor Heat Exchanger 30 Indoor Heat Exchanger 40 Motor Coil 50 Outdoor Air Temperature Sensor 60 Temperature Sensor 70 Control Device

Claims (11)

A control device for an air conditioner equipped with an outdoor unit equipped with a compressor,
The outdoor unit includes an outside air temperature sensor provided inside the outdoor unit to detect an outside air temperature,
The compressor is provided with a motor coil of a motor for driving the compressor therein.
When the outside air temperature detected by the outside air temperature sensor is −2° C. or less and greater than the first outside air temperature threshold value while the air conditioner is stopped, the current value to be passed to the motor coil is set to the first current value, When the air temperature is equal to or lower than the first outside air temperature threshold value, an air conditioner that performs current control for controlling the current value so that the current value flowing to the motor coil becomes a second current value larger than the first current value. The control device of the device. If the current value is the second current value and the outside air temperature detected by the outside air temperature sensor exceeds a temperature obtained by adding 2° C. to the first outside air temperature threshold, the current value is changed to the first current value. The control device for an air conditioner according to claim 1. The current value is set to a third current value larger than the second current value when the outside air temperature detected by the outside air temperature sensor is equal to or less than a second outside air temperature threshold value lower than the first outside air temperature threshold value. A control device for an air conditioner according to. When the current value is the third current value and the outside air temperature detected by the outside air temperature sensor exceeds a temperature obtained by adding 2° C. to the second outside air temperature threshold value, the current value is changed to the second current value. The control device for the air conditioner according to claim 3. A temperature sensor for detecting the discharge temperature of the refrigerant is provided on the discharge side of the compressor,
The control device for an air conditioner according to any one of claims 1 to 4, wherein the current control is stopped when the discharge temperature is equal to or higher than a first discharge temperature threshold. The control device of the air conditioner according to claim 5, wherein the current control is started when the discharge temperature becomes equal to or lower than a second discharge temperature threshold value lower than the first discharge temperature threshold value while the current control is stopped. When the current value is the third current value, and if the discharge temperature is equal to or higher than a third discharge temperature threshold value lower than the second discharge temperature threshold value, the current value is set to the second current value value. A control device for the air conditioner described. The air conditioner according to claim 6 or 7, wherein when the current value is the second current value and the discharge temperature is equal to or higher than the second discharge temperature threshold value, the current value is set to the first current value. The control device of the device. An air conditioner comprising the control device according to any one of claims 1 to 8. A method for controlling an air conditioner equipped with an outdoor unit equipped with a compressor,
The outdoor unit includes an outside air temperature sensor provided inside the outdoor unit to detect an outside air temperature,
The compressor is provided with a motor coil of a motor for driving the compressor therein.
When the outside air temperature detected by the outside air temperature sensor is −2° C. or less and greater than the first outside air temperature threshold value while the air conditioner is stopped, the current value to be passed to the motor coil is set to the first current value, An air conditioner including a step of controlling the current value so that the current value flowing to the motor coil is a second current value larger than the first current value when the temperature is equal to or lower than the first outside air temperature threshold value. Control method. A control program applied to an air conditioner including an outdoor unit including a compressor,
The outdoor unit includes an outside air temperature sensor provided inside the outdoor unit to detect an outside air temperature,
The compressor is provided with a motor coil of a motor for driving the compressor therein.
When the outside air temperature detected by the outside air temperature sensor is −2° C. or less and greater than the first outside air temperature threshold value while the air conditioner is stopped, the current value to be passed to the motor coil is set to the first current value, An air conditioner including a step of controlling the current value such that the current value flowing to the motor coil is a second current value larger than the first current value when the temperature is equal to or lower than the first outside air temperature threshold value. Control program applied to.

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