JPH0921556A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner, in which blowing of hot wind is accelerated after termination of defrosting to provide a favorable startup of heating. SOLUTION: An indoor fan is switched over from a set air quantity operation set by a remote controller 61 to a gentle wind operation in response to reduction in a temperature Tc of an indoor heat exchanger caused by defrosting, and is stopped in response to further reduction in the temperature Tc. The indoor fan is switched over from stoppage to the gentle wind operation in response to rise in the temperature Tc caused by completion of defrosting, and simultaneously with such switch-over, a flowrate regulating valve 32 is fully opened. The indoor fan is switched over to the set air quantity operation in response to further rise in the temperature Tc, and simultaneously with such switch-over, the flowrate regulating valve 32 is returned to a normal opening degree.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-type air conditioner capable of air conditioning a plurality of rooms.

[0002]

2. Description of the Related Art A multi-type air conditioner in which a plurality of indoor units are connected to an outdoor unit can air-condition a plurality of rooms and is installed, for example, in a building with a large number of rooms.

The outdoor unit is provided with a compressor, a four-way valve, and an outdoor heat exchanger. A flow control valve and an indoor heat exchanger are provided in each of the plurality of indoor units. The compressor, the four-way valve, the outdoor heat exchanger, each flow rate adjusting valve, and each indoor heat exchanger are sequentially pipe-connected to form a heat pump refrigeration cycle.

In each indoor unit, the opening of the flow rate adjusting valve is controlled according to the difference between the temperature of the indoor air and a preset value. By this opening degree control, the refrigerant flow rate to each indoor heat exchanger is adjusted. Further, a command corresponding to the difference between the temperature of the indoor air and the set value is sent from each indoor unit to the outdoor unit. The outdoor unit controls the capacity of the compressor according to a command sent from each indoor unit.

During heating operation, frost gradually adheres to the surface of the outdoor heat exchanger functioning as an evaporator, and if it remains as it is, the amount of heat exchange in the outdoor heat exchanger decreases and the heating capacity deteriorates. Defrosting is performed on the outdoor heat exchanger according to the above.

In this defrosting, the refrigerant discharged from the compressor is supplied to the outdoor heat exchanger as it is, and the frost adhering to the outdoor heat exchanger is removed by the heat of the high temperature refrigerant, and the same cycle as during cooling is formed. There is so-called reverse cycle defrosting, or bypass defrosting that opens a bypass provided between the discharge side of the compressor and the outdoor heat exchanger.

During defrosting, the heat of the refrigerant is used for defrosting, so that the temperature of the indoor heat exchanger decreases.
If the indoor fan was operated with the air volume set by the remote control, cold air would be blown into the room, causing discomfort to the inhabitants.

Therefore, the temperature of the indoor heat exchanger is detected during defrosting, and the indoor fan is stopped in response to the decrease in the detected temperature to prevent cold air from blowing out. Then, when the defrosting ends and the temperature of the indoor heat exchanger recovers, the indoor fan is returned to the operation of the set air volume.

[0009]

When the defrosting ends and the temperature of the indoor heat exchanger recovers, the indoor fan is returned to the operation of the set air volume, but the heat exchanger temperature does not recover immediately. Is the actual situation. Therefore, there is a problem that it takes time until the hot air is blown out and the rise of the heating is deteriorated.

Particularly, when the piping length between the outdoor unit and the indoor unit is long, or when the indoor unit is at a position considerably higher than the outdoor unit, the temperature rise of the indoor heat exchanger is further delayed.

The present invention takes the above circumstances into consideration,
The air conditioner of the first aspect of the present invention has an object to accelerate the blowing of warm air after the completion of defrosting so that heating can be favorably started up.

The air conditioner of the second aspect of the present invention is intended to enable early blowing of warm air at the start of heating operation as well as after completion of defrosting, thereby enabling a good start-up of heating. An air conditioner according to a third aspect of the present invention is, in the first or second aspect, an object of the present invention is to enable the warm air to be blown out early and the heating to be excellently started even after the heating operation is interrupted based on the indoor temperature control. .

An air conditioner according to a fourth aspect of the present invention includes a first air conditioner, a second air conditioner, and
And in any of the third invention, regardless of the pipe length or height position between the outdoor unit and the indoor unit,
The purpose is to ensure a good start of heating.

[0014]

An air conditioner of a first invention is a refrigeration cycle in which a compressor, an outdoor heat exchanger, a plurality of flow rate adjusting valves, and a plurality of indoor heat exchangers are connected to circulate a refrigerant. A plurality of indoor fans that circulate the indoor air through the indoor heat exchangers, a plurality of temperature detecting means that detect the temperature of each indoor heat exchanger, and the refrigerant discharged from the compressor for each indoor heat exchanger and each flow rate. A means for performing heating operation by returning to the compressor through the adjustment valve and the outdoor heat exchanger, and frost adhering to the outdoor heat exchanger by directly supplying the refrigerant discharged from the compressor to the outdoor heat exchanger during the heating operation. The indoor fan is switched from the set air volume operation to the breeze operation when the temperature detected by each temperature detection means decreases due to defrost, and the indoor fan stops when the detected temperature further decreases. With the provision of the first control means , Switched to breeze operation from stopping the indoor fan in response to an increase in the temperature detected by the respective temperature sensing means by defrosting completion, fully open the flow control valve at the same time as this switching,
There is provided second control means for switching each indoor fan to the set air volume operation in accordance with a further increase in the detected temperature, and at the same time as switching this, returning each flow rate adjusting valve to the normal opening degree.

The air conditioner of the second invention is the air conditioner of the first invention, further, when the heating operation is started, each indoor fan is switched from the stop to the breeze operation in accordance with an increase in the temperature detected by each temperature detecting means, Simultaneously with this switching, open each flow rate adjustment valve,
A third control means is provided in which each indoor fan is switched to a set air volume operation in response to a further increase in the detected temperature, and at the same time as this switching, each flow rate adjusting valve is returned to the normal opening degree.

The air conditioner of a third invention is the air conditioner of the first or second invention, further, after the heating operation is interrupted based on the indoor temperature control, each indoor fan is turned on in response to an increase in the temperature detected by each temperature detecting means. Switch from stop to breeze operation, at the same time as this switching, open each flow rate adjustment valve fully, switch each indoor fan to set air volume operation according to the further rise in detected temperature, and at the same time, switch each flow rate adjustment valve to the normal opening. A fourth control means for returning is provided.

The air conditioner of the fourth invention comprises the first, second, and
Further, in any one of the third aspect of the invention, when the stop of each indoor fan continues for a certain period of time or more without a sufficient increase in the temperature detected by each temperature detecting means due to the completion of defrosting, the control of the second control means is involved. Instead, a fifth control means for fully opening the flow rate adjusting valves is provided.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 2, a plurality of indoor units Y are pipe-connected to the outdoor unit X. The outdoor unit X includes compressors 1 and 2. These compressors 1 and 2 are housed in a common closed case, and each sucks, compresses, and discharges a refrigerant. The compressor 1 is an inverter-driven variable capacity compressor. Compressor 2
Is a fixed-capacity compressor driven by a commercial power source.

High-pressure side tubes 4 are connected to the discharge ports of the compressors 1 and 2, respectively. A check valve 3 is provided on the high-pressure side pipe 4 connected to the discharge port of the compressor 2. The low-pressure side tubes 5 are connected to the suction ports of the compressors 1 and 2, respectively.

An outdoor heat exchanger 8 is connected to the high pressure side pipe 4 via an oil separator 6 and a four-way valve 7. A dryer 11 is connected to the outdoor heat exchanger 8 via a check valve 9 and a liquid tank 10. An expansion valve 12 for heating is connected in parallel with the check valve 9. An outdoor fan 13 is provided near the outdoor heat exchanger 8.

An accumulator 14 is attached to the low pressure side pipe 5.
And the strainer 15 is connected via the four-way valve 7. The oil separator 6 extracts the lubricating oil contained in the refrigerant discharged from the compressors 1 and 2. From the oil separator 6 to the low-pressure side pipe 5, an oil return pipe 1
6 is connected.

One end of the cooling bypass 17 is connected to the pipe between the check valve 9 and the liquid tank 10. The other end of the cooling bypass 17 is connected to the low pressure side pipe between the four-way valve 7 and the accumulator 14. Then, a variable opening valve 18 is provided in the cooling bypass 17.

A high pressure switch 21 and a temperature sensor 25 are attached to a pipe extending from the discharge port of the compressor 1 to the high pressure side pipe 4. High-pressure side pipe 4 between the discharge port of the compressor 2 and the check valve 3
Then, the high-voltage switch 22 and the temperature sensor 26 are mounted. The high-pressure switches 21 and 22 operate when the pressure of the refrigerant abnormally increases and reaches a predetermined value.

A pressure sensor 23 is attached to the high pressure side tube 4. The pressure sensor 24 and the temperature sensor 2 are attached to the low-pressure side pipe 5.
7 is installed. The heat exchanger temperature sensor 28 is attached to the outdoor heat exchanger 8. An outdoor air temperature sensor 29 is attached to a predetermined location of the outdoor unit X.

An indoor heat exchanger 33 is connected between the dryer 11 and the strainer 15 via a strainer 31 and a flow rate adjusting valve 32. An indoor fan 34 is provided near the indoor heat exchanger 33.

The flow rate adjusting valve 32 is a so-called pulse motor valve (PMV) whose opening continuously changes according to the number of input drive pulses, and the flow rate of the refrigerant can be adjusted by changing the opening. it can. The variable opening valve 18 is also
It is a similar pulse motor valve.

A pressure sensor 35 and a temperature sensor 37 are attached to a pipe between the flow rate adjusting valve 32 and the indoor heat exchanger 33. In particular, the temperature sensor 37 is attached near the indoor heat exchanger 33. At the position between the indoor heat exchanger 33 and the strainer 15 near the indoor heat exchanger 33, the pressure sensor 3
6 and the temperature sensor 38 are attached. In particular, the temperature sensor 38 is attached near the indoor heat exchanger 33. An indoor temperature sensor 39 is provided in the flow path of the indoor air sucked by the operation of the indoor fan 34.

The construction from the strainer 31 to the indoor temperature sensor 39 is the same for all indoor units Y. A pipe connection from the outdoor unit X to each indoor unit Y constitutes a heat pump type refrigeration cycle.

During cooling, a cooling cycle is formed in which the refrigerant discharged from the compressors 1 and 2 flows in the direction of the solid arrow in the figure, and the outdoor heat exchanger 8 serves as a condenser and each indoor heat exchanger 33 serves as an evaporator. Make it work.

During heating, the flow path of the four-way valve 7 is switched to form a heating cycle in which the refrigerant discharged from the compressors 1 and 2 flows in the direction of the broken line arrow in the drawing, and each indoor heat exchanger 33 is condensed. The vessel and the outdoor heat exchanger 8 function as an evaporator.

On the other hand, the control circuit is shown in FIG. An outdoor control unit 50 is provided in the outdoor unit X. An indoor control unit 60 is provided in each indoor unit Y. Then, the outdoor control unit 50 and each indoor control unit 60 are connected by wiring.

The outdoor controller 50 comprises a microcomputer and its peripheral circuits. In this outdoor control unit 50,
Four-way valve 7, outdoor fan motor 13M, variable opening valve 18,
High-voltage switches 21 and 22, pressure sensors 23 and 24, temperature sensors 25, 26 and 27, heat exchanger temperature sensor 28, outside air temperature sensor 29, commercial AC power supply 51, inverter 5
2 and the switch 53 are connected.

The inverter 52 rectifies the voltage of the commercial AC power supply 51 and switches it to switch the outdoor control unit 5
The voltage is converted into a voltage having a frequency according to the command from 0 and is output. This output is the driving power for the compressor motor 1M.

The switch 53 is, for example, a contact of an electromagnetic contactor. The compressor motor 2M is connected to the AC power supply line in the outdoor control unit 50 via the switch 53. The indoor control unit 60 is composed of a microcomputer and its peripheral circuits. The indoor control unit 60 is provided with a flow rate adjusting valve 3
2, the pressure sensors 35 and 36, the temperature sensors 37 and 38, the room temperature sensor 39, a remote control type operation device (hereinafter referred to as a remote controller) 61, and a speed control circuit 62 are connected. The speed control circuit 62 controls the speed of the indoor fan motor 34M, and the air volume of the indoor fan 34 can be adjusted by this speed control.

Each indoor control unit 60 has the following functional means. [1] A means for sending an operation mode command, an operation start command, an operation stop command, etc. to the outdoor unit X based on the operation of the remote controller 61.

[2] The difference ΔT between the temperature Ta detected by the indoor temperature sensor 39 (temperature of the intake air) Ta and the set value Ts determined by the operation of the remote controller 61 is obtained, and the frequency command corresponding to the temperature difference ΔT is determined. , Means to send it to the outdoor unit X.

The frequency command is the number of operating compressors 1 and 2,
And for setting the capacity of the compressor 1. [3] A means for controlling the opening of the flow rate adjusting valve 32 according to the frequency command (that is, the temperature difference ΔT).

[4] The indoor fan 34 is switched from the set air volume operation by the remote controller 61 to the slight air operation according to the decrease in the temperature Tc (corresponding to the temperature of the indoor heat exchanger 33) Tc detected by the defrosting described later. , Further detection temperature Tc
Control means for stopping the indoor fan 34 in response to the decrease of the temperature.

[5] The indoor fan 34 is switched from the stop mode to the breeze operation in accordance with the rise in the detected temperature Tc due to the completion of defrosting.
Simultaneously with this switching, the flow rate adjusting valve 32 is fully opened, and the indoor fan 34 is controlled by the remote controller 6 as the detected temperature Tc further rises.
Second control means for switching to the set air volume operation by 1 and returning the flow rate adjusting valve 32 to the normal opening degree according to the frequency command at the same time as this switching.

[6] At the start of the heating operation, the indoor fan 34 is switched from the stop to the breeze operation according to the rise of the detected temperature Tc, and at the same time as this switching, the flow rate adjusting valve 32 is fully opened to further increase the detected temperature Tc. In response, the indoor fan 34 is switched to the set air volume operation by the remote controller 61, and at the same time as this switching, the flow control valve 32 is returned to the normal opening degree according to the frequency command.

[7] After the heating operation is interrupted based on the indoor temperature control, the indoor fan 34 is switched from the stop to the breeze operation in accordance with the rise in the detected temperature Tc, and at the same time as this switching, the flow rate adjusting valve 3
2 is fully opened, the indoor fan 34 is switched to a set air volume operation by the remote controller 61 in accordance with a further increase in the detected temperature Tc, and at the same time as this switching, the flow rate control valve 32 is returned to the normal opening degree according to the frequency command. .

[8] When the detection temperature Tc has not risen sufficiently due to the completion of defrosting and the indoor fan 34 is stopped for a certain period of time or more, the flow rate adjusting valve 32 is fully opened regardless of the control of the second control means. Control means.

On the other hand, the outdoor control unit 50 of the outdoor unit X
Has the following functional means. [1] The refrigerant discharged from the compressor 1 (and 2) is the four-way valve 7, the outdoor heat exchanger 8, each flow rate adjusting valve 32, each indoor heat exchanger 3
3, a cooling operation means for performing a cooling operation by forming a cooling cycle that returns to the compressor 1 (and 2) through the four-way valve 7.

[2] The flow path of the four-way valve 7 is switched so that the refrigerant discharged from the compressor 1 (and 2) has the four-way valve 7, the indoor heat exchangers 33, the flow rate adjusting valves 32, the outdoor heat exchanger 8, Heating operation means for performing a heating operation by forming a heating cycle that returns to the compressor 1 (and 2) through the four-way valve 7.

[3] Capacity of compressors 1 and 2, that is, number of operating compressors 1 and 2 and capacity of compressor 1 (inverter 5
A means for setting the output frequency F of 2 according to the frequency command sent from each indoor unit Y.

[4] Heat exchanger temperature sensor 2 during heating operation
8 detection temperature (temperature of the outdoor heat exchanger 8) Te,
A means for determining that the outdoor heat exchanger 8 has frosted when the detected temperature Te becomes equal to or lower than 0 ° C., and then determines the defrosting completion when the detected temperature Te rises to a temperature higher by a predetermined value than 0 ° C.

[5] During heating operation, the refrigerant discharged from the compressor 1 (and 2) flows to the outdoor heat exchanger 8 as it is from the judgment of frost formation to the judgment of defrost completion. A defrosting unit that forms a cycle (same as a cooling cycle) and removes frost attached to the outdoor heat exchanger 8.

[6] When the pressure Pd detected by the pressure sensor 23 abnormally rises and reaches the set value Pdx (lower than the operating points of the high pressure switches 21 and 22), the capacity of the compressor 1 (the output frequency F of the inverter 52). A first protection means for reducing a predetermined value.

[7] A second protection means for stopping the operation of the compressor 1 when the high pressure switch 21 is activated and stopping the operation of the compressor 2 when the high pressure switch 22 is activated. [8] Temperature detected by temperature sensor 25 (discharged refrigerant temperature) T _d1
And the temperature detected by the temperature sensor 26 (discharged refrigerant temperature) T _d2
When either one of the above increases to the set value Tdx, the opening degree variable valve 18 of the cooling bypass 17 is opened and the opening degree is set to Tdx.
A means for controlling the higher of _d1 and T _d2 .

Next, the operation of the above configuration will be described with reference to FIGS.
This will be described with reference to FIGS. 5 and 6. FIG. 3 shows the operation of the outdoor unit X. FIG. 4 shows indoor fan control conditions in each indoor unit Y. 5 and 6 show the operation of each indoor unit Y.

When the occupant sets a desired operation mode and set value Ts with the remote controller 61 of any indoor unit Y and further performs an operation to start the operation, at least the compressor 1 of the compressors 1 and 2 is started, The operation is started.

In the cooling operation mode, the cooling medium is caused to flow in the direction of the solid line arrow to form a cooling cycle. As a result, the outdoor heat exchanger 8 functions as a condenser and the indoor heat exchanger 33 functions as an evaporator. In the heating operation mode, the flow path of the four-way valve 7 is switched to allow the refrigerant to flow in the direction of the broken arrow in FIG. 2 to form the heating cycle. As a result, the indoor heat exchanger 33 functions as a condenser and the outdoor heat exchanger 8 functions as an evaporator.

In the indoor unit Y, the indoor temperature sensor 39
The difference ΔT between the detected temperature (intake air temperature) Ta and the set value Ts determined by the remote controller 61 is obtained, and the frequency command corresponding to the temperature difference ΔT is sent to the outdoor unit X. further,
The opening degree of the flow rate adjusting valve 32 is set to an opening degree according to the frequency command (hereinafter, the opening degree according to the frequency command is referred to as a normal opening degree).

In the outdoor unit X, the capacities of the compressors 1 and 2 (the number of operating compressors 1 and 2 and the capacity of the compressor 1) are
It is set for a predetermined time, for example, every 2 minutes according to the frequency command sent from each indoor unit Y.

For example, when the content of the frequency command, that is, the required capacity is small, the output frequency F of the inverter 52 is controlled to execute the capacity variable operation by the compressor 1 alone.
When the required capacity increases, the output frequency F of the inverter 52 is controlled, the switch 53 is turned on, and the capacity variable operation of the compressor 1 and the capacity fixed operation of the compressor 2 are executed.

When the heating operation is executed, frost gradually adheres to the surface of the outdoor heat exchanger 8 functioning as an evaporator, and if it is left as it is, the amount of heat exchange in the outdoor heat exchanger 8 decreases and the heating capacity decreases. Becomes

As a countermeasure, during the heating operation, the temperature detected by the heat exchanger temperature sensor 28 (the temperature of the outdoor heat exchanger 8) Te is monitored in the outdoor unit X, and the detected temperature Te falls below 0 ° C. Then, it is determined that the outdoor heat exchanger 8 has frosted. Based on this determination, the flow path switching of the four-way valve 7 is released, and so-called reverse cycle defrosting for the outdoor heat exchanger 8 is started.

In the reverse cycle defrost, the refrigerant discharged from the compressor 1 (and 2) directly flows into the outdoor heat exchanger 8,
Frost attached to the outdoor heat exchanger 8 is removed by the heat of the high-temperature refrigerant.

After that, when the detected temperature Te rises to a temperature higher than 0 ° C. by a predetermined value, it is determined that the defrosting is completed. Based on this determination, the flow path of the four-way valve 7 is switched, the reverse cycle defrosting is finished, and the original heating operation is restored.

However, during defrosting, the heat of the refrigerant is used for defrosting, so that in each indoor unit Y, the temperature Tc of the indoor heat exchanger 33 decreases, and the indoor fan 3
If 4 is operated with the air volume set by the remote controller 61, cold air will be blown into the room, which will give discomfort to the inhabitants.

Therefore, in each indoor unit Y, the temperature Tc of the indoor heat exchanger 33 is detected by the temperature sensor 37, and the following control is performed by comparing the detected temperature Tc with the indoor fan control conditions shown in FIG.

That is, when the detected temperature Tc drops to the B zone below the set value T ₃ due to defrosting, the indoor fan 3
4 is switched from the set air volume operation by the remote controller 61 to the slight air operation. When the detected temperature Tc further decreases to the C zone below the set value T ₁ (<T ₃ ), the indoor fan 34 is stopped. By this stop, the blowing of cold air into the room is prevented.

After that, when the defrosting ends and the normal heating operation is restored, the detected temperature Tc starts to rise. When the detected temperature Tc rises to the B zone above the set value T ₂ (> T ₁ , <T ₃ ), the indoor fan 34 is switched from the stop to the breeze operation. Simultaneously with this switching, the flow rate adjusting valve 32 is fully opened. This full opening is to increase the flow rate of the refrigerant to the indoor heat exchanger 33 and promote the temperature rise of the indoor heat exchanger 33.

For control purposes, the flag f is used as a means for knowing whether or not the indoor fan 34 is in a stopped state. f = “0” indicates that the indoor fan 34 has not stopped yet, and f = “1” indicates that the indoor fan 34 has stopped.

The detected temperature Tc is further set value T ₄ (> T
₃ ) When the temperature rises to the zone A above, the indoor fan 34 is switched to the set air volume operation by the remote controller 61. Simultaneously with this switching, the flow rate adjusting valve 32 is returned to the normal opening degree.

As described above, by fully opening the flow rate adjusting valve 32 in time with the end of defrosting, the temperature rise of the indoor heat exchanger 33 can be promoted, and the indoor fan 34 is set from the breeze operation. It is possible to quickly switch to air volume operation. Therefore. After the defrosting is finished, warm air can be blown out faster, and the heating can be started up better.

If the pipe length between the outdoor unit X and the indoor unit Y is long, or if the indoor unit Y is at a position considerably higher than the outdoor unit X, the indoor heat exchanger 33 after defrosting is completed. The temperature rise slows considerably.

Therefore, when the detected temperature Tc remains in the C zone (the indoor fan 34 is stopped) for a predetermined time or more, the flow rate adjusting valve 32 is forcibly fully opened there. By this fully opening, the outdoor unit X and the indoor unit Y
A good rise of heating is ensured regardless of the pipe length and height position between and.

By the way, among the indoor units Y, the temperature of the indoor heat exchanger 33 in the indoor unit Y in which the operation is stopped or in the indoor unit Y in which the operation is interrupted (thermo-off) based on the indoor temperature control is performed. It is in a lowered state. Also in these indoor units Y, the temperature sensor 37
The following control is performed by comparing the detected temperature Tc of No. 2 with the indoor fan control condition shown in FIG.

If the detected temperature Tc is in the C zone below the set value T ₂ , the indoor fan 34 is stopped. By this stop, the blowing of cold air into the room is prevented. When the heating operation is started or the heating operation is restarted after the operation is interrupted, the detected temperature Tc
Is raised to the B zone of the set value T ₂ or more, the indoor fan 34 is switched from the stop to the breeze operation. Simultaneously with this switching, the flow rate adjusting valve 32 is fully opened. This full opening is to increase the flow rate of the refrigerant to the indoor heat exchanger 33 and promote the temperature rise of the indoor heat exchanger 33.

If the detected temperature Tc is more than the set value T ₄ A
When rising to the zone, the indoor fan 34 is switched from the light breeze operation to the set air volume operation by the remote controller 61. Simultaneously with this switching, the flow rate adjusting valve 32 is returned to the normal opening degree.

Therefore, the temperature rise of the indoor heat exchanger 33 can be promoted even when the heating operation is started and the heating operation is restarted after the operation is interrupted, and the indoor fan 34 is quickly switched from the breeze operation to the set air volume operation. be able to. Therefore, warm air is blown out faster, and the rise of heating is improved. The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

[0073]

As described above, according to the present invention, in the air conditioner of the first invention, the indoor fans are operated from the set air volume operation according to the decrease in the temperature detected by the temperature detecting means due to defrosting. Switching to operation, the indoor fan is stopped in response to a further decrease in the detected temperature, and each indoor fan is switched from stop to a breeze operation in response to the increase in the detected temperature of each temperature detection means due to the completion of defrosting. Since each flow rate adjustment valve is fully opened and each indoor fan is switched to the set air volume operation in response to a further rise in the detected temperature, and this flow rate adjustment valve is returned to the normal opening at the same time as this switching, after defrosting is completed The hot air can be blown out earlier, and the heating can be started up better.

The air conditioner of the second invention is the air conditioner of the first invention, further, at the start of the heating operation, each indoor fan is switched from the stop to the breeze operation in accordance with an increase in the temperature detected by each temperature detecting means, Simultaneously with this switching, open each flow rate adjustment valve,
Each indoor fan is switched to the set air volume operation in response to a further increase in the detected temperature, and at the same time as this switching, each flow rate adjustment valve is returned to the normal opening degree, so the temperature at the start of heating operation is not only after defrosting has ended. The blowing of air can be accelerated and good heating can be achieved.

The air conditioner of the third invention is the air conditioner of the first or second invention, further, after the heating operation is interrupted based on the indoor temperature control, each indoor fan is turned on in response to an increase in the temperature detected by each temperature detecting means. Switch from stop to breeze operation, at the same time as this switching, open each flow rate adjustment valve fully, switch each indoor fan to set air volume operation according to the further rise in detected temperature, and at the same time, switch each flow rate adjustment valve to the normal opening. Since it is configured to return, even after heating operation interruption based on indoor temperature control,
It is possible to speed up the blowing of warm air and achieve good heating.

The air conditioner of the fourth invention comprises the first, second, and
Further, in any one of the third aspect of the invention, when the stop of each indoor fan continues for a certain period of time or more without a sufficient increase in the temperature detected by each temperature detecting means due to the completion of defrosting, the control of the second control means is involved. Instead, since each of the flow rate adjusting valves is fully opened, good heating can be reliably started regardless of the pipe length and height position between the outdoor unit and the indoor unit.

[Brief description of drawings]

FIG. 1 is a block diagram of a control circuit according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a refrigeration cycle of the same embodiment.

FIG. 3 is a flowchart for explaining the operation of the outdoor unit of the same embodiment.

FIG. 4 is a diagram showing an indoor fan control condition of the embodiment.

FIG. 5 is a flowchart for explaining the operation of each indoor unit of the same embodiment.

FIG. 6 is a flowchart following FIG. 5;

[Explanation of symbols]

X ... Outdoor unit, Y ... Indoor unit, 1,2 ... Compressor, 8 ... Outdoor heat exchanger, 32 ... Flow control valve, 33 ... Indoor heat exchanger, 34 ... Indoor fan, 37 ... Temperature sensor (temperature detection means ), 50 ... Outdoor control unit, 60 ... Indoor control unit, 6
1 ... remote control.

Claims (4)

[Claims] 1. A refrigeration cycle in which a refrigerant is circulated by connecting a compressor, an outdoor heat exchanger, a plurality of flow rate control valves, and a plurality of indoor heat exchangers, and indoor air is circulated through each of the indoor heat exchangers. A plurality of indoor fans, a plurality of temperature detecting means for detecting the temperature of each of the indoor heat exchangers, the refrigerant discharged from the compressor to the indoor heat exchangers, the flow rate adjustment valve, the outdoor heat exchanger And a defrosting means for supplying the refrigerant discharged from the compressor to the outdoor heat exchanger as it is during heating operation to remove frost adhering to the outdoor heat exchanger. And first control means for switching the indoor fans from the set air volume operation to the breeze operation in response to a decrease in the temperature detected by the temperature detecting means due to defrosting and stopping the indoor fan in accordance with a further decrease in the detected temperature. Due to the end of defrosting In accordance with an increase in the temperature detected by each of the temperature detecting means, the indoor fans are switched from stop to breeze operation,
Simultaneously with this switching, each flow rate adjusting valve is fully opened, each indoor fan is switched to the set air volume operation according to a further increase in the detected temperature, and at the same time as this switching, the second flow control valve is returned to the normal opening degree. An air conditioner characterized by comprising: 2. The air conditioner according to claim 1, wherein
Further, at the start of the heating operation, each indoor fan is switched from the stop to the breeze operation in response to the increase in the temperature detected by each of the temperature detecting means,
Simultaneously with this switching, each flow rate adjusting valve is fully opened, each indoor fan is switched to the set air volume operation in response to a further increase in the detected temperature, and at the same time as this switching, the third flow control valve is returned to the normal opening degree. An air conditioner characterized by being provided with. 3. The air conditioner according to claim 1 or 2, further, after the heating operation is interrupted based on indoor temperature control, each indoor fan is stopped in response to an increase in the temperature detected by each temperature detecting means. To light breeze operation, and at the same time, the flow rate adjustment valves are fully opened at the same time, and the indoor fans are switched to the set air volume operation in response to a further increase in the detected temperature. An air conditioner characterized by being provided with a fourth control means for returning. 4. The air conditioner according to any one of claims 1, 2, and 3, further, in which the temperature detected by each of the temperature detecting means due to the completion of defrosting is insufficient to increase the temperature in each room. An air conditioner comprising: fifth control means for fully opening the flow rate adjusting valves regardless of the control of the second control means when the fan is stopped for a certain period of time or longer.