WO2019163346A1

WO2019163346A1 - Air conditioner

Info

Publication number: WO2019163346A1
Application number: PCT/JP2019/001444
Authority: WO
Inventors: 裕記藤岡; 智彦堤; 晃宏中野
Original assignee: ダイキン工業株式会社
Priority date: 2018-02-23
Filing date: 2019-01-18
Publication date: 2019-08-29
Also published as: JP2019143950A

Abstract

A control device (100) for an air conditioner, having: a determining unit (100b) for determining whether or not the indoor air conditioning load is equal to or below a prescribed air conditioning load, if, after a cooling operation is temporarily stopped by a first operation control unit (100a), the indoor temperature (T₁) detected by an indoor temperature sensor (16c) is higher than an indoor temperature (T₀) set by a user, or if, after a heating operation is temporarily stopped by a first operation control unit (100a), the indoor temperature (T₁) detected by an indoor temperature sensor (16c) is lower than an indoor temperature (T₀) set by a user; and a second operation control unit (100c) which, when it is determined by the determining unit (100b) that the indoor air conditioning load is equal to or below the prescribed air conditioning load, restarts the cooling operation or the heating operation under a condition in which a compressor (1) drives at a prescribed frequency and an indoor fan (5c) rotates at a rotation speed lower than the rotation speed that the user can set manually.

Description

Air conditioner

This disclosure relates to air conditioners.

Conventionally, as an air conditioner, there is one disclosed in JP-A-5-10625 (Patent Document 1). When the temperature reading value of the room temperature sensor is lower than the room temperature set value, the air conditioner starts the compressor and sets the blower in the indoor unit (hereinafter referred to as “indoor blower”) to the high wind mode to perform the heating operation. do.

JP-A-5-10625

In the conventional air conditioner described above, since the indoor fan operates in the strong wind mode, the temperature reading value of the room temperature sensor exceeds the room temperature set value in a shorter time than when the indoor fan does not operate in the strong wind mode. At this time, when the heating operation is temporarily stopped and the temperature reading value of the room temperature sensor is lower than the room temperature setting value again, the heating operation is resumed, and thus the problem of frequent start / stop occurs.

This disclosure provides an air conditioner that can suppress an increase in the number of starts and stops.

The air conditioner of this disclosure is
A refrigerant circuit having a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger, in which the refrigerant circulates;
An indoor fan for blowing air to the indoor heat exchanger;
An indoor temperature sensor for detecting the indoor temperature;
A control device,
The control device
During cooling operation, when the room temperature detected by the room temperature sensor is equal to or lower than the room temperature set by the user, the cooling operation is temporarily stopped, while during heating operation, the room temperature detected by the room temperature sensor is A first operation control unit for temporarily stopping the heating operation when the temperature is equal to or higher than the indoor temperature set by the user;
After the cooling operation is temporarily stopped by the first operation control unit, when the room temperature detected by the room temperature sensor is higher than the room temperature set by the user, or the heating operation is performed by the first operation control unit When the indoor temperature detected by the indoor temperature sensor is lower than the indoor temperature set by the user after the suspension is stopped, the determination unit determines whether the indoor air conditioning load is equal to or lower than a predetermined air conditioning load. When,
When the determination unit determines that the indoor air conditioning load is equal to or less than the predetermined air conditioning load, the indoor fan rotates at a rotational speed lower than the rotational speed that can be manually set by the user, and the compressor A second operation control unit that restarts the cooling operation or the heating operation under a condition of driving at a predetermined frequency.

According to the above configuration, after the cooling operation and the heating operation are stopped by the first operation control unit, the cooling operation or the heating operation is restarted by the second operation control unit according to the determination result of the determination unit. At this time, since the cooling operation or the heating operation is restarted under the condition that the indoor fan rotates at a rotation speed lower than the rotation speed that can be manually set by the user, an increase in the number of start / stop times can be suppressed.

In the air conditioner according to one aspect of the present disclosure,
The control device is configured to restart the cooling operation or the heating operation temporarily stopped by the first operation control unit when the determination unit determines that the indoor air conditioning load exceeds a predetermined air conditioning load. Have
The predetermined frequency is equal to or lower than a frequency used for driving the compressor in the cooling operation or the heating operation restarted by the third operation control unit.

According to the above aspect, when the cooling operation or the heating operation is restarted by the second operation control unit, the frequency used for driving the compressor in the cooling operation or the heating operation restarted by the third operation control unit. In the following, the compressor is driven. Therefore, the occurrence of dew can be suppressed during the cooling operation, while the occurrence of a short circuit can be suppressed during the heating operation.

In the air conditioner according to one aspect of the present disclosure,
The predetermined frequency is the lowest frequency among the frequencies for operating the compressor.

According to the above aspect, when the cooling operation or the heating operation is resumed by the second operation control unit, the compressor is driven at the lowest frequency among the frequencies for operating the compressor. The effect which suppresses generation | occurrence | production of a circuit can be heightened.

In the air conditioner according to one aspect of the present disclosure,
The cooling operation or heating operation that is temporarily stopped by the first operation control unit is an automatic cooling operation or automatic heating operation that automatically changes the rotation speed of the indoor fan according to the indoor temperature detected by the indoor temperature sensor. is there.

According to the above aspect, the first cooling unit can surely temporarily stop the automatic cooling operation or the automatic heating operation.

In the air conditioner according to one aspect of the present disclosure,
After the cooling operation is restarted by the second operation control unit, the control device is configured such that the room temperature detected by the room temperature sensor is higher than the room temperature set by the user, or the second operation control. When the indoor temperature detected by the indoor temperature sensor is lower than the indoor temperature set by the user after the heating operation is restarted at the section, the control mode of the rotational speed of the indoor fan and the frequency of the compressor is set. And a control mode changing unit for changing to the control mode of the cooling operation or the heating operation temporarily stopped by the first operation control unit.

According to the above aspect, the control mode changing unit can suppress an increase in the difference between the room temperature and the set temperature after the cooling operation is restarted by the second operation control unit.

In the air conditioner according to one aspect of the present disclosure,
The rated cooling output is less than 2.2 kW.

According to the above aspect, since the rated cooling capacity is less than 2.2 kW, air conditioning suitable for a narrow space such as a washroom or a kitchen can be performed.

It is a lineblock diagram of a multi type air harmony machine provided with the low capacity indoor unit of one embodiment of this indication. It is the external view seen from the diagonally lower side of the said low capacity indoor unit. It is a block diagram of the indoor control apparatus of the said low capacity indoor unit. It is a flowchart for demonstrating the control which the said indoor control apparatus performs at the time of automatic cooling operation. It is a flowchart for demonstrating the control which the said indoor control apparatus performs at the time of automatic heating operation.

Hereinafter, embodiments of the air conditioner will be described. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is a configuration diagram of a multi-type air conditioner including a low-capacity indoor unit 20C according to an embodiment of the present disclosure.

As shown in FIG. 1, the multi-type air conditioner includes an indoor unit 20A having an indoor heat exchanger 4A and an indoor fan 5A, an indoor unit 20B having an indoor heat exchanger 4B and an indoor fan 5B, and indoor heat exchange. A low-capacity indoor unit 20C having a unit 4C and an indoor fan 5C, and an outdoor unit 10 connected to the

indoor units

20A and 20B and the low-capacity indoor unit 20C via a refrigerant pipe. The indoor fans 5A, 5B, 5C send air to the indoor heat exchangers 4A, 4B, 4C.

The outdoor unit 10 corresponds to a multi-type air conditioner to which a plurality of indoor units can be connected, and the low-capacity indoor unit 20C can operate as an indoor unit of the multi-type air conditioner.

In FIG. 1, 1 is a compressor, 2 is a four-way switching valve with one end connected to the discharge side of the compressor 1, 3 is an outdoor heat exchanger with one end connected to the other end of the four-way switching valve 2, EVA , EVB, EVC are electric expansion valves having one end connected to the other end of the outdoor heat exchanger 3, respectively. An exchanger 6 is an accumulator in which one end is connected to the other end of the indoor heat exchangers 4A, 4B, and 4C via the four-way switching valve 2 and the other end is connected to the suction side of the compressor 1. Indoor fans 5A, 5B, 5C are arranged in the vicinity of the indoor heat exchangers 4A, 4B, 4C, respectively. The electric expansion valve EVC is an example of an expansion mechanism.

Also, a plurality of refrigerant pipe connection portions 7A, 7B, 7C are connected to the other ends of the electric expansion valves EVA, EVB, EVC, and the plurality of refrigerant pipe connection portions 7A, 7B, 7C are connected to the other refrigerant piping connection ports (refrigerant pipes). One end of each of the indoor heat exchangers 4A, 4B, 4C is connected. A plurality of refrigerant

pipe connection portions

8A, 8B, and 8C are connected to the other ends of the indoor heat exchangers 4A, 4B, and 4C through connection pipes (refrigerant pipes).

The compressor 1, the four-way switching valve 2, the outdoor heat exchanger 3, the electric expansion valves EVA, EVB, EVC, the indoor heat exchangers 4A, 4B, 4C, and the accumulator 6 constitute a refrigerant circuit. This refrigerant circuit is filled with, for example, a slightly flammable R32 refrigerant.

Further, a discharge pipe temperature sensor 11 is provided on the discharge side of the compressor 1. The outdoor heat exchanger 3 is provided with an outdoor heat exchanger temperature sensor 12 for detecting the outdoor heat exchanger temperature, and an outdoor temperature sensor 13 for detecting the outdoor temperature is provided in the vicinity of the outdoor heat exchanger 3.

Also, the indoor heat exchanger 4A is provided with an indoor heat exchanger temperature sensor 15A that detects the temperature of the indoor heat exchanger, and an indoor temperature sensor 16A that detects the indoor temperature is provided near the indoor heat exchanger 4A. The indoor heat exchanger 4B is provided with an indoor heat exchanger temperature sensor 15B that detects the temperature of the indoor heat exchanger, and an indoor temperature sensor 16B that detects the indoor temperature is provided near the indoor heat exchanger 4B. The indoor heat exchanger 4C is provided with an indoor heat exchanger temperature sensor 15C that detects the temperature of the indoor heat exchanger, and an indoor temperature sensor 16C that detects the indoor temperature is provided near the indoor heat exchanger 4C.

The outdoor unit 10 includes an outdoor control device 18 including a microcomputer and an input / output circuit. The

indoor units

20A and 20B are each provided with an indoor control device (not shown), and the low-capacity indoor unit 20C is provided with an indoor control device 100 (shown in FIG. 3). The indoor control device 100 is an example of a control device.

The indoor control devices of the

indoor units

20A and 20B and the indoor control device 100 of the low capacity indoor unit 20C communicate with the outdoor control device 18 of the outdoor unit 10 via a communication line (not shown), thereby The control device 18, the indoor control devices of the

indoor units

20A and 20B, and the indoor control device 100 of the low-capacity indoor unit 20C operate in cooperation, thereby operating as a multi-type air conditioner.

In the above-described multi-type air conditioner, when the cooling operation is performed by the

indoor units

20A and 20B and the low-capacity indoor unit 20C, the four-way switching valve 2 is switched to the dotted line position and the operation of the compressor 1 is started. Then, the electric expansion valves EVA, EVB, EVC are each opened to a predetermined opening degree. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 is condensed by a heat exchange with the outdoor air by operating an outdoor fan (not shown) in the outdoor heat exchanger 3 to become a liquid refrigerant. Next, the liquid refrigerant from the indoor heat exchangers 4A, 4B, 4C is decompressed by the electric expansion valves EVA, EVB, EVC, and then the indoor fans 5A, 5B, 5C are operated to operate the indoor heat exchanger 4A, At 4B and 4C, it evaporates by heat exchange with room air to become a gas refrigerant, and returns to the suction side of the compressor 1.

Here, the rated cooling capacity of the

indoor units

20A and 20B is 2.2 kW, and the rated cooling capacity of the low capacity indoor unit 20C is 0.8 kW. That is, the low-capacity indoor unit 20C has a lower capacity than the

indoor units

20A and 20B.

On the other hand, when heating operation is performed with the

indoor units

20A and 20B and the low-capacity indoor unit 20C, the four-way switching valve 2 is switched to the position of the solid line, and the operation of the compressor 1 is started. Then, the electric expansion valves EVA, EVB, EVC are each opened to a predetermined opening degree. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 is condensed by heat exchange with indoor air in the indoor heat exchangers 4A, 4B, and 4C by operating the indoor fans 5A, 5B, and 5C. Become. Next, the liquid refrigerant from the indoor heat exchangers 4A, 4B, 4C is decompressed by the electric expansion valves EVA, EVB, EVC, and then an outdoor fan (not shown) is operated by the outdoor heat exchanger 3. It evaporates by heat exchange with the outdoor air to become a gas refrigerant and returns to the suction side of the compressor 1.

FIG. 2 is an external view of the low-capacity indoor unit 20C viewed obliquely from below. This indoor unit is a ceiling-embedded indoor unit.

As shown in FIG. 2, the low-capacity indoor unit 20C includes a casing main body 101, a rectangular panel 102 attached to the lower side of the casing main body 101, and a grill 103 detachably attached to the panel 102. ing.

The blower outlet 110 is provided along the short side of the panel 102 on one side in the longitudinal direction of the panel 102. A flap 120 is rotatably attached to the panel 102. FIG. 2 shows a state in which the air outlet 110 is closed by the flap 120.

Further, a drain socket 107 is provided so as to protrude from the side wall of the casing body 101. A drain hose (not shown) is connected to the drain socket 107 from the outside. Further, the

pipe connecting portions

105 and 106 are provided so as to protrude from the side wall of the casing main body 101. A refrigerant pipe (not shown) is connected to the

pipe connecting portions

105 and 106 from the outside.

In FIG. 2, reference numeral 108 denotes an electrical component part, and reference numerals 111 to 113 denote suspension fittings provided so as to protrude laterally from the casing main body 101, respectively.

FIG. 3 is a block diagram of the indoor control device 100 of the low-capacity indoor unit 20C.

The low-capacity indoor unit 20C includes an indoor control device 100 including a microcomputer and an input / output circuit as shown in FIG. In the indoor control device 100, an indoor heat exchanger temperature sensor 15C, an indoor temperature sensor 16C, a fan motor 21, a flap drive unit 22, and a display unit 23 are connected. In addition, the indoor control device 100 includes a first operation control unit 100a, a determination unit 100b, a second operation control unit 100c, and a control mode change unit 100e. Moreover, the indoor control device 100 can grasp the outdoor temperature detected by the outdoor temperature sensor 13 by communicating with the outdoor control device 18.

When the room temperature detected by the room temperature sensor 16C is equal to or lower than the room temperature set by the user during the automatic cooling operation, the first operation control unit 100a temporarily stops the automatic cooling operation, while during the automatic heating operation, When the room temperature detected by the room temperature sensor 16C is equal to or higher than the room temperature set by the user, the automatic heating operation is temporarily stopped.

Here, the automatic cooling operation means a cooling operation in which the rotation speed of the indoor fan 5C is automatically changed according to the room temperature detected by the room temperature sensor 16C. The automatic heating operation means a heating operation in which the rotational speed of the indoor fan 5C is automatically changed according to the indoor temperature detected by the indoor temperature sensor 16C.

After the automatic cooling operation is temporarily stopped by the first operation control unit 100a, the determination unit 100b is configured such that the room temperature detected by the room temperature sensor 16C is higher than the room temperature set by the user, or the first operation. If the indoor temperature detected by the indoor temperature sensor 16C is lower than the indoor temperature set by the user after the automatic heating operation is temporarily stopped by the control unit 100a, is the indoor air conditioning load equal to or lower than the predetermined air conditioning load? Determine whether or not.

When the determination unit 100b determines that the indoor air conditioning load is equal to or lower than the predetermined air conditioning load, the second operation control unit 100c rotates the indoor fan 5C at a rotation speed lower than the rotation speed that can be manually set by the user. In addition, the automatic cooling operation or the automatic heating operation is restarted under the condition that the compressor 1 is driven at a predetermined frequency.

When the determination unit 100b determines that the indoor air conditioning load exceeds the predetermined air conditioning load, the third operation control unit 100d resumes the automatic cooling operation or the automatic heating operation temporarily stopped by the first operation control unit 100a. .

The control mode changing unit 100e is configured to start the second operation when the indoor temperature detected by the indoor temperature sensor 16C is higher than the indoor temperature set by the user after the automatic cooling operation is resumed by the second operation control unit. After the automatic heating operation is resumed by the control unit, when the indoor temperature detected by the indoor temperature sensor 16C is lower than the indoor temperature set by the user, the rotational speed of the indoor fan 5C and the frequency of the compressor 1 are controlled. The mode is changed to the control mode of automatic cooling operation or automatic heating operation temporarily stopped by the first operation control unit 100a.

FIG. 4 is a flowchart for explaining the control performed by the indoor control device 100 during the automatic cooling operation. This control starts in response to the start of automatic cooling operation.

When the above control starts, as shown in FIG. 4, first, in step S1, the room temperature T ₁ detected by the room temperature sensor 16C is a temperature obtained by subtracting a predetermined temperature (eg, 2 ° C.) from the set temperature T _0. (Hereinafter, it is referred to as “first reference temperature T _0-2 ”). In this step S1, if it is determined that the indoor temperature _{T 1} is equal to or less than the first reference temperature _{T 0-2,} the process proceeds to the next step S2. On the other hand, in step S1, the indoor temperature _{T 1} is is determined not to be less than the first reference temperature _{T 0-2,} the step S1 again. Note that the set temperature T ₀ means, for example, a temperature set by a user with a remote controller (not shown).

Next, in step S2, the automatic cooling operation is thermo-OFF. That is, the compressor 1 and the indoor fan 5C are stopped, and the automatic cooling operation is temporarily stopped.

Next, in step S3, the indoor temperature T ₁ is the set temperature T ₀ at a predetermined temperature (for example, 1 ° C.) and the mixture was temperature (hereinafter, referred to as "second reference temperature T _{0 + 1".)} Or more or is not Determine whether. In this step S3, when determining the indoor temperature _{T 1} of that the second reference temperature _{T 0 + 1} or more, the process proceeds to the next step S4. On the other hand, in step S3, performed when the indoor temperature _{T 1} of the determined not second reference temperature _{T 0 + 1} or more, the step S3 again.

Next, in step S4, it is determined whether the indoor air conditioning load is equal to or less than a predetermined standard air conditioning load. More specifically, in step S4, the indoor temperature T ₁ is predetermined indoor temperature (e.g. 27 ° C.) or less, and the outdoor temperature T ₂ detected by the outdoor temperature sensor 13 is a predetermined outdoor temperature (e.g. 35 ° C. ) It is determined whether the following is true. In this step S4, the indoor temperature T ₁ is less than the predetermined indoor temperature, and when the outdoor temperature T ₂ is determined to be equal to or less than a predetermined outdoor temperature, the flow proceeds to the next step S5. On the other hand, in step S4, the indoor temperature T ₁ is less than the predetermined indoor temperature, and when the outdoor temperature T ₂ is determined not to become below a predetermined outdoor temperature, in step S11, and restarts the automatic cooling operation Return to step S1.

Next, in step S5, the small capacity cooling operation is started. The rotation speed of the indoor fan 5C in the small capacity cooling operation is set to a rotation speed (for example, 650 rpm) smaller than the rotation speed corresponding to the minimum air volume that can be manually set in the low capacity indoor unit 20C during the cooling operation. . At this time, the air volume of the low-capacity indoor unit 20C is, for example, 1 m ³ / min. Further, the frequency of the compressor 1 in the small capacity cooling operation is set to a frequency (6 Hz) lower than the frequency (for example, 10 Hz) of the compressor 1 for the automatic cooling operation restarted in step S11. Further, during the small capacity cooling operation, the rotation speed of the indoor fan 5C and the frequency of the compressor 1 are kept constant.

Here, the air volume of the low-capacity indoor unit 20C is, for example, six levels of “large air volume”, “first intermediate air volume”, “medium air volume”, “second intermediate air volume”, “small air volume”, and “micro air volume”. It is possible to set manually. The “first intermediate air volume” is smaller than the “large air volume” and larger than the “medium air volume”. Further, the “second intermediate air volume” is an air volume that is smaller than the “medium air volume” and larger than the “small air volume”. The “large air volume” is an air volume larger than the “medium air volume”, and the “small air volume” is an air volume smaller than the “medium air volume”. That is, the “minute air volume” corresponds to the minimum air volume that can be manually set in the low-capacity indoor unit 20C. Further, when the “minute air volume” is manually set, the rotational speed of the indoor fan 5C is, for example, 1000 rpm.

Next, in step S6, it is determined whether the indoor temperature T ₁ is exceeds the set temperature T _0. In this step S6, when the indoor temperature T ₁ is is determined to exceed the set temperature T _0, in step S7, and ends the small capacity cooling operation, the process proceeds to step S11. On the other hand, in step S6, when the indoor temperature T ₁ is is determined not to exceed the set temperature T _0, is performed again step S6.

Here, the first operation control unit 100a executes step S2, the determination unit 100b executes step S4, and the second operation control unit 100c executes step S5. Further, when the process proceeds from step S4 to step S11, the third operation control unit 100d executes step S11. When the process proceeds from step S6 to step S11, the control mode changing unit 100e executes steps S7 and S11.

As described above, when the low-capacity indoor unit 20C performs thermo-return and performs the automatic cooling operation, the second operation control unit 100c executes step S5. Therefore, the rotation speed is lower than the rotation speed that can be manually set by the user. The indoor fan 5C rotates. Therefore, since no indoor temperature T ₁ is below the set temperature T ₀ in a short time, when cooling the room, it is possible to suppress the increase of the start-stop number.

Further, when the low-capacity indoor unit 20C performs thermo-return and performs automatic cooling operation, the second operation control unit 100c executes step S5, so that the frequency is lower than the frequency of the compressor 1 for automatic cooling operation restarted in step S11. The compressor 1 is driven at a low frequency. Therefore, condensation is less likely to occur at the flap 120. That is, the occurrence of dew can be suppressed in the low-capacity indoor unit 20C.

In addition, since the first operation control unit 100a executes Step S2, the automatic cooling operation can be surely temporarily stopped.

In addition, since the third operation control unit 100d and the control mode change unit 100e execute S11, the user does not need to set the air volume of the low-capacity indoor unit 20C again.

Further, since the control mode changing unit 100e executes the step S7, S11, it is possible to suppress after small capacity cooling operation is started, that the difference between the indoor temperature T ₁ of the set temperature T ₀ increases.

Moreover, since the rated cooling capacity of the low-capacity indoor unit 20C is less than 2.2 kW, it is possible to perform cooling suitable for a narrow space such as a washroom or a kitchen.

FIG. 5 is a flowchart for explaining the control performed by the indoor control device 100 during the automatic heating operation. This control starts in response to the start of automatic heating operation.

When the control is started, as shown in FIG. 5, first, in step S21, the temperature of the room temperature T ₁ of which is detected by the indoor temperature sensor 16C is, by adding a predetermined temperature (for example, 2 ° C.) from the set temperature T ₀ (Hereinafter, referred to as “third reference temperature T _{0 + 2} ”). In this step S21, if it is determined that the indoor temperature _{T 1} is at the third reference temperature _{T 0 + 2} or more, the process proceeds to the next step S22. On the other hand, in step S21, performs the indoor temperature _{T 1} is is determined not to be the third reference temperature _{T 0 + 2} or more, the step S21 again. Note that the set temperature T ₀ means, for example, a temperature set by a user with a remote controller (not shown).

Next, in step S22, the automatic heating operation is thermo-off. That is, the compressor 1 and the indoor fan 5C are stopped, and the automatic heating operation is temporarily stopped.

Next, in step S23, the indoor temperature _{T 1} is the set temperature _{T 0} at a predetermined temperature (for example, 1 ° C.) and the mixture was temperature (hereinafter, referred to as "second reference temperature _{T 0 + 1".)} Or more or is not Determine whether. In this step S23, when determining the indoor temperature _{T 1} of that the second reference temperature _{T 0 + 1} or more, the process proceeds to the next step S24. On the other hand, in step S23, it performs the indoor temperature _{T 1} of the determined not second reference temperature _{T 0 + 1} or more, the step S23 again.

Next, in step S24, it is determined whether the indoor air conditioning load is equal to or less than a predetermined standard air conditioning load. More specifically, in step S24, the indoor temperature T ₁ is predetermined indoor temperature (e.g. 20 ° C.) or less, and the outdoor temperature T ₂ detected by the outdoor temperature sensor 13 is a predetermined outdoor temperature (e.g. 7 ° C. ) It is determined whether it is above. In this step S24, the indoor temperature T ₁ is less than the predetermined indoor temperature, and when the outdoor temperature T ₂ is determined to be equal to or greater than the predetermined outdoor temperature, the flow proceeds to the next step S25. On the other hand, in step S24, the indoor temperature T ₁ is less than the predetermined indoor temperature, and when the outdoor temperature T ₂ is determined not to become higher than a predetermined outdoor temperature, in step S31, and restarts the automatic heating operation Return to step S21.

Next, in step S25, the small capacity heating operation is started. The rotation speed of the indoor fan 5C in the small capacity heating operation is set to a rotation speed (for example, 800 rpm) smaller than the rotation speed corresponding to the minimum air volume that can be manually set in the low capacity indoor unit 20C, that is, the “micro air volume”. The At this time, the air volume of the low-capacity indoor unit 20C is, for example, 1.5 m ³ / min. Further, the frequency of the compressor 1 in the small capacity heating operation is set to a frequency (10 Hz) lower than the frequency (for example, 14 Hz) of the compressor 1 for the automatic heating operation restarted in step S31. Further, during the small capacity heating operation, the rotation speed of the indoor fan 5C and the frequency of the compressor 1 are kept constant.

Next, in step S26, it is determined whether the indoor temperature _{T 1} is less than the set temperature _{T 0.} In this step S26, when the indoor temperature T ₁ is is determined to be less than the set temperature T _0, in step S27, and terminates the small capacity heating operation, the flow proceeds to step S31. On the other hand, in step S26, when the indoor temperature _{T 1} is is determined not to be less than the set temperature _{T 0,} is performed again step S26.

Here, the first operation control unit 100a executes step S22, the determination unit 100b executes step S24, and the second operation control unit 100c executes step S25. Further, when the process proceeds from step S24 to step S31, the third operation control unit 100d executes step S31. Further, when the process proceeds from step S26 to step S31, the control mode changing unit 100e executes steps S27 and S31.

As described above, when the low-capacity indoor unit 20C performs the automatic heating operation after returning to the thermo state, the second operation control unit 100c executes Step S25, so that the rotation speed is lower than the rotation speed that can be manually set by the user. The indoor fan 5C rotates. Therefore, since no indoor temperature T ₁ is higher than the set temperature T ₀ in a short time, when heating the room, it is possible to suppress the increase of the start-stop number.

Further, when the low-capacity indoor unit 20C returns to the thermo state and performs the automatic heating operation, since the second operation control unit 100c executes step S25, the frequency of the compressor 1 for the automatic heating operation restarted in step S31 is exceeded. The compressor 1 is driven at a low frequency. Therefore, the phenomenon that the warm air blown from the low-capacity indoor unit 20C rises without passing through the lower part of the indoor space and is sucked into the low-capacity indoor unit 20C is less likely to occur. That is, the occurrence of a short circuit can be suppressed.

Moreover, since the 1st operation control part 100a performs Step S22, automatic heating operation can be stopped temporarily reliably.

In addition, since the third operation control unit 100d and the control mode change unit 100e execute S31, the user does not need to set the air volume of the low-capacity indoor unit 20C again.

Further, since the control mode changing unit 100e executes the steps S27, S31, it is possible to suppress after small capacity heating operation is started, that the difference between the indoor temperature T ₁ of the set temperature T ₀ increases.

Moreover, since the rated cooling capacity of the low-capacity indoor unit 20C is less than 2.2 kW, heating suitable for a narrow space such as a washroom or a kitchen can be performed.

In the above embodiment, the rated cooling capacity of the low-capacity indoor unit 20C is 0.8 kW, but may be other than 0.8 kW. In this case, the low-capacity indoor unit 20C is installed from the viewpoint of air-conditioning the low-capacity indoor unit 20C in a space such as a washroom (for example, a room area of 3.3 m ² × ceiling height of 2.4 m). The rated cooling capacity is preferably less than 2.2 kW.

In the above embodiment, when the automatic cooling operation is turned off in step S2, the control in steps S2 to S7 and S11 is performed. However, the cooling operation other than the automatic cooling operation (for example, the cooling in which the air flow rate is fixed). When the operation is turned off, the same control as in steps S2 to S7 and S11 may be performed.

In the above-described embodiment, when it is determined in step S4 that the indoor air conditioning load is not equal to or less than the predetermined standard air conditioning load, the automatic cooling operation temporarily stopped with the thermo OFF is resumed in step S11. However, an operation other than the automatic cooling operation (for example, a cooling operation in which the air flow rate is fixed) may be started.

In the above embodiment, the frequency of the compressor 1 during the small capacity cooling operation is set to be lower than the frequency of the compressor 1 for the automatic cooling operation restarted in step S11. It may be the same as the frequency or the same as the lowest frequency among the frequencies for operating the compressor.

In the above embodiment, when the automatic heating operation is turned off in step S22, the control in steps S22 to S27 and S31 is performed. However, the heating operation other than the automatic heating operation (for example, heating in which the air flow rate is fixed) is performed. When the operation is turned off, the same control as in steps S22 to S27 and S31 may be performed.

In the above embodiment, when it is determined in step S24 that the indoor air conditioning load is not equal to or less than the predetermined standard air conditioning load, the automatic heating operation temporarily stopped with the thermo-OFF is resumed in step S31. However, an operation other than the automatic heating operation (for example, a heating operation in which the air flow rate is fixed) may be started.

In the said embodiment, although the frequency of the compressor 1 at the time of small capacity heating operation was made to become lower than the frequency of the compressor 1 of automatic heating operation restarted by step S31, It may be the same as the frequency or the same as the lowest frequency among the frequencies for operating the compressor.

In the above embodiment, at least one of the first operation control unit 100a, the determination unit 100b, the second operation control unit 100c, and the control mode change unit 100e may be configured by software or by hardware. It may be configured.

Although specific embodiments of the present disclosure have been described, the present disclosure is not limited to the first and second embodiments described above, and various modifications can be made within the scope of the present disclosure.

1 Compressor 2 Four-way selector valve,
3 outdoor heat exchanger,
4A, 4B, 4C Indoor heat exchanger 5A, 5B, 5C Indoor fan 6 Accumulator 7A, 7B, 7C Refrigerant

pipe connection part

8A, 8B, 8C Refrigerant pipe connection part 10 Outdoor unit 11 Discharge pipe temperature sensor 12 Outdoor heat exchanger temperature Sensor 13

Outdoor temperature sensor

15A, 15B, 15C Indoor heat

exchanger temperature sensor

16A, 16B, 16C Indoor temperature sensor 18

Outdoor controller

20A, 20B ... Indoor unit 20C Low-capacity indoor unit 100 Indoor controller 100a First operation controller 100b Determination unit 100c Second operation control unit 100d Third operation control unit 100e Control mode change unit EVA, EVB, EVC Electric expansion valve

Claims

A refrigerant circuit having a compressor (1), an outdoor heat exchanger (3), an expansion mechanism (EVC), and an indoor heat exchanger (4C), wherein the refrigerant circulates;
An indoor fan (5c) for blowing air to the indoor heat exchanger (4C);
An indoor temperature sensor (16c) for detecting the indoor temperature;
A control device (100),
The control device (100)
During the cooling operation, when the indoor temperature (T 1 ) detected by the indoor temperature sensor (16c) is equal to or lower than the indoor temperature (T 0 ) set by the user, the cooling operation is temporarily stopped, while during the heating operation, A first operation control unit (100a) for temporarily stopping the heating operation when the indoor temperature (T 1 ) detected by the indoor temperature sensor (16c) is equal to or higher than the indoor temperature (T 0 ) set by the user;
After the cooling operation is temporarily stopped by the first operation control unit (100a), the room temperature (T 1 ) detected by the room temperature sensor (16c) is higher than the room temperature (T 0 ) set by the user. When the temperature is high, or after the heating operation is temporarily stopped by the first operation control unit (100a), the room temperature (T 1 ) detected by the room temperature sensor (16c) is the room temperature set by the user ( A determination unit (100b) that determines whether or not the air conditioning load in the room is equal to or lower than a predetermined air conditioning load when lower than T 0 );
When it is determined by the determination unit (100b) that the indoor air conditioning load is equal to or less than the predetermined air conditioning load, the indoor fan (5c) rotates at a rotational speed lower than the rotational speed that can be manually set by the user, And the air conditioner characterized by having a 2nd operation control part (100c) which restarts air_conditionaing | cooling operation or heating operation on the conditions which drive the said compressor (1) with a predetermined frequency.
In the air conditioner according to claim 1,
When the determination unit 100b determines that the indoor air conditioning load exceeds a predetermined air conditioning load, the control device (100) performs the cooling operation or the heating operation temporarily stopped by the first operation control unit (100a). Having a third operation control unit (100d) to resume,
The air conditioner characterized in that the predetermined frequency is equal to or lower than a frequency used for driving the compressor (1) in the cooling operation or the heating operation restarted by the third operation control unit (100d). .
In the air conditioner according to claim 1 or 2,
The air conditioner is characterized in that the predetermined frequency is a lowest frequency among frequencies for operating the compressor (1).
In the air conditioner according to any one of claims 1 to 3,
The cooling operation or heating operation temporarily stopped by the first operation control unit (100a) is performed by the indoor fan (5c) according to the indoor temperature (T 1 ) detected by the indoor temperature sensors (16c) and (16c). An air conditioner characterized in that it is an automatic cooling operation or an automatic heating operation in which the rotation speed is automatically changed.
In the air conditioner according to any one of claims 1 to 4,
After the cooling operation is resumed by the second operation control unit (100c), the control device (100) has an indoor temperature (T 1 ) detected by the indoor temperature sensor (16c) determined by the user. When the temperature is higher than the temperature (T 0 ), or after the heating operation is restarted by the second operation control unit (100c), the indoor temperature (T 1 ) detected by the indoor temperature sensor (16c) is the user Is lower than the set indoor temperature (T 0 ), the control mode of the rotational speed of the indoor fan (5c) and the frequency of the compressor (1) is temporarily stopped by the first operation control unit (100a). An air conditioner having a control mode change unit (100e) for changing to a control mode of the cooling operation or heating operation.
In the air conditioner according to any one of claims 1 to 5,
An air conditioner having a rated cooling output of less than 2.2 kW.