JP2000234789A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner capable of realizing the correct freezing- preventive control. SOLUTION: An air conditioner is provided with heat exchange temperature sensors 36, 37 to detect the temperature of each user side heat exchanger, and a controller 33 to control the number of revolution of a compressor and each blower based on the output of the heat exchange temperature sensors 36, 37, the controller 33 performs the freezing-preventive control to limit or stop the operation of the compressor when the temperature of the user side heat exchanger is dropped below a specified value in a cooling mode or a dry operating mode, and changes the specified value according to the total of the number of revolution of each blower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which air exchanged with a plurality of use-side heat exchangers is blown into a conditioned room by a plurality of blowers to air-condition.

[0002]

2. Description of the Related Art A conventional air conditioner of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 10-122592 as a ceiling-mounted air conditioner. That is, in this case, the unit (indoor unit) of the air conditioner is housed inside the ceiling of the room to be conditioned, and the use side heat exchanger and the blower are mounted in this unit.

The use side heat exchanger constitutes a predetermined refrigerant circuit with a compressor of a unit installed outside (outdoor unit), a four-way switching valve, a heat source side heat exchanger, and the like, and is used for cooling / drying / heating. Exhibits the effects of Then, the air in the conditioned room is sucked by the blower and exchanged with the use-side heat exchanger, and then blown out from the outlet into the conditioned room to be air-conditioned. And the blowing direction of the air blown out from the outlet is controlled by the flap.

If the temperature of the use side heat exchanger drops abnormally during the cooling / dry operation, the use side heat exchanger freezes. In this case, when the temperature decreases to a predetermined value (temperature). The anti-freezing control for limiting the operation speed of the compressor and finally stopping the operation has been executed.

[0005]

As described above, in the air conditioner, the freeze prevention control during the cooling / drying operation has been conventionally performed. However, the air conditioner is provided with a plurality of use-side heat exchangers and air-conditioned. When air is blown out to the conditioned room by the blowers, the temperature data detected by the heat exchange temperature sensor differs depending on the operating speed of each blower.

That is, the temperature data based on the temperature of the use side heat exchanger detected by the heat exchange temperature sensor differs depending on the work of each blower, that is, the rotation speed of the motor that drives them. Therefore, when the blower is working, that is, when the rotation speed of the motor is high, the danger of icing of the use side heat exchanger is reduced, but conversely, when the blower is not working, that is, On the other hand, when the rotation speed of the motor is low, the danger of freezing of the use side heat exchanger increases.

For this reason, when the anti-freezing control is executed at a predetermined set value, the capacity of the compressor is limited without the necessity of such control, and conversely, the capacity of the compressor is notwithstanding the fact that it freezes immediately. There was a problem that inconvenience such as rising was caused.

The present invention has been made to solve the above-mentioned conventional technical problem, and an object of the present invention is to provide an air conditioner capable of realizing accurate freeze prevention control.

[0009]

An air conditioner according to the present invention comprises:
It is composed of a compressor, a heat source side heat exchanger, a plurality of use side heat exchangers, etc., and air is blown into the conditioned room by a plurality of blowers, respectively, for air exchanged with each use side heat exchanger, for air conditioning. A heat exchange temperature sensor for detecting the temperature of the use side heat exchanger; and a control device for controlling the operation speed of the compressor and each blower based on the output of the heat exchange temperature sensor. If, during cooling or dry operation, the temperature of the use side heat exchanger falls below a predetermined value,
The present invention is characterized in that the operation speed of the compressor is restricted, or anti-freeze control for stopping the operation is executed, and a predetermined value is changed according to the sum of the operation speed of each blower.

[0010] According to the present invention, a compressor, a heat source side heat exchanger, a plurality of use side heat exchangers and the like are provided, and air exchanged with each use side heat exchanger is covered by a plurality of blowers. In an air conditioner that blows air into a conditioned room and air-conditions, a heat exchange temperature sensor that detects a temperature of a use side heat exchanger, and an operation speed of a compressor and each blower is controlled based on an output of the heat exchange temperature sensor. A control device, wherein the control device limits the operating speed of the compressor or stops the operation when the temperature of the use side heat exchanger falls below a predetermined value during cooling or dry operation. Since the control is executed and the predetermined value is changed in accordance with the sum of the operation speeds of the blowers, for example, the predetermined value is reduced when the sum of the speeds is large, and the reverse is performed when the sum is small. Raised to It allows maintaining the cooling effect of the air conditioner, it is possible to reliably prevent icing of the use-side heat exchanger.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an air conditioner A to which the present invention is applied.
2 is a sectional view of the use side unit (indoor unit) A of C, FIG.
Is a refrigerant circuit diagram of the air conditioner AC, FIG. 3 is an electric circuit diagram of the use side unit A, and FIG. 7 shows the conditioned room 1 in which the use side unit A is installed.

In FIG. 1 and FIG.
Has two built-in heat exchangers (indoor heat exchangers) 3 and 4 and two blowers 6 and 7 each composed of a cross flow fan in a main body 2 made of sheet metal. The harmony room 1 is fitted inside the ceiling so as to cover the ceiling surface 8. A suction port 9 is formed in the center of the lower surface of the main body 2 which is substantially flush with the ceiling surface 8, and an air outlet 11 is provided on both sides thereof.
12 are formed. In addition, the filter 1 is
0 is attached. The use side heat exchangers 3 and 4
Are arranged so that their lower ends are located on both sides of the suction port 9 and their upper ends are inclined so as to be closer to the upper center of the suction port 9, and the blowers 6, 7 are connected to the respective use-side heat exchangers 3, 3. 4 and each outlet 11, 12. When the blowers 6 and 7 are operated, the air in the conditioned room 1 is sucked from the suction port 9 and flows into the use-side heat exchangers 3 and 4.

The conditioned air that has flowed into the use side heat exchanger 3 and exchanged heat is accelerated by the blower 6 and
Is blown out into the harmonized room 1. The conditioned air that has flowed into the use-side heat exchanger 4 and exchanged heat is accelerated by the blower 7 and blown out of the outlet 12 into the conditioned room 1.

In this case, flaps 13 and 14 as wind direction plates are respectively attached to the air outlets 11 and 12, and the blowing direction of the conditioned air is adjusted up and down in a plurality of steps by the angles of the flaps 13 and 14. You. Also,
An infrared receiver 16 from a remote controller to be described later is attached to the lower surface of the use side unit A.

In the embodiment, the use side unit A is installed substantially at the center of the ceiling surface 8 of the room 1 to be harmonized, and a zone (region) on the left side from the center of the room 1 as shown by a broken line in FIG. The outlet 11 is located in the living) Z1, and the outlet 12 is located in the right zone (area; dining, for example) Z2.
Is located.

Next, referring to FIG. 2, the air conditioner A of the embodiment will be described.
C comprises the ceiling-mounted use-side unit A installed indoors as described above, and the heat-source-side unit (outdoor unit) B installed outdoors, and both are connected by the refrigerant pipe 21.

In this figure, reference numeral 22 denotes a so-called inverter compressor (variable capacity type compressor, hereinafter referred to as a compressor) whose frequency (Hz) is controlled by an inverter. As means for varying the capacity of the compressor, there are other methods such as voltage control when a DC motor is used or discharge amount control when a capacity variable valve is used. 23 is a four-way switching valve for switching the flow of the refrigerant during the cooling / heating operation, 24 is a heat source side heat exchanger (outdoor heat exchanger), 25 is an electric expansion valve, 26 and 27 are electric expansion valves for branching, 3 and 4 are the use side heat exchangers, 28
Is an accumulator.

In this case, the use-side heat exchanger 3 is connected in series with the diverting electric expansion valve 26, the consuming-side heat exchanger 4 is connected in series with the diverting electric expansion valve 27, and each series circuit is The configuration is such that they are connected to each other in parallel.

In this configuration, the direction of the refrigerant discharged from the compressor 22 is determined according to the three modes of the cooling operation, the heating operation, and the dry operation in accordance with the switching position of the four-way switching valve 23.

That is, during the cooling operation, the high-temperature and high-pressure refrigerant discharged from the compressor 22 passes through the four-way switching valve 23, the heat source side heat exchanger 24, and the electric expansion valve 25, and is divided into two parts. The fluid flows through the expansion valve 26 to the use-side heat exchanger 3, and the other flows to the use-side heat exchanger 4 through the flow-dividing electric expansion valve 27. And the refrigerant | coolants which came out of each use side heat exchanger 3 and 4 join and circulate in the order of the four-way switching valve 23 and the accumulator 28. At this time, the heat source side heat exchanger 24 functions as a condenser, and the utilization side heat exchangers 3 and 4 function as evaporators.

Next, during the heating operation, the high-temperature and high-pressure refrigerant discharged from the compressor 22 exits the four-way switching valve 23,
One is flowed to the flow-dividing electric expansion valve 26 via the use-side heat exchanger 3, and the other is flowed to the flow-dividing electric expansion valve 27 via the use-side heat exchanger 4. Then, the electric expansion valve 25, the heat source side heat exchanger 24, the four-way switching valve 23, the accumulator 2
Cycle in the order of 8. At this time, each use side heat exchanger 3,
4 functions as a condenser, and the heat source side heat exchanger 24 functions as an evaporator.

In the dry operation, the flow is the same as that in the cooling operation. However, the electric expansion valve 25 is fully opened, and the front stage of each of the use side heat exchangers 3 and 4 is a condenser, and then the pressure is reduced and the rear stage is operated. Is configured to function as an evaporator to provide a dehumidifying effect.

Next, in FIG. 3, reference numeral 33 denotes a controller (control board) composed of a general-purpose microcomputer. The controller 33 includes a use side unit A for detecting the temperature in the conditioned room 1. Room temperature sensor 30 attached to the
5, heat exchange temperature sensors 36 and 37, and outlet temperature sensor 3
8, 39 are connected.

As shown in FIG. 2, the inlet temperature sensor 34 is attached to a pipe on the refrigerant inlet side of the use side heat exchanger 3 during the cooling operation, and the inlet temperature sensor 35 is also used during the cooling operation. It is attached to a pipe on the refrigerant inlet side of the heat exchanger 4 and detects the temperature of the pipe. The heat exchange temperature sensor 36 is attached to a pipe in the use side heat exchanger 3 to detect the temperature of the use side heat exchanger 3, and the heat exchange temperature sensor 37 is connected to the inside of the use side heat exchanger 4. Attached to the pipe, the temperature of the use side heat exchanger 4 is detected. Further, an outlet temperature sensor 38 is attached to a pipe that is a refrigerant outlet side of the use side heat exchanger 3 during the cooling operation, and an outlet temperature sensor 39 is also a refrigerant outlet side of the use side heat exchanger 4 during the cooling operation. And the temperature of each pipe is detected.

The controller 33 has flap motors 41, 4 comprising stepping motors for driving the flaps 13 and 14 to adjust the angle (wind direction).
2 is connected, and D for driving the blowers 6 and 7 is connected.
Fan motors 43 and 44 composed of C motors are connected,
Further, a sensor board 46 is also connected. This sensor substrate 4
6, the receiver 16 is provided, and various lamps 46A to 46D made of LEDs are also provided.

Further, the controller 33 drives the flow-dividing electric expansion valves 26 and 27 to drive the respective use-side heat exchangers 3,
The valve motors 47 and 48, which are stepping motors for adjusting the flow rate (opening) of the refrigerant to 4, are also connected. The controller 33 is electrically connected to a control board (controller) (not shown) of the heat source side unit B from the terminal plate 49 via a cable.

Next, the operation of the air conditioner AC will be described while explaining the structures of the main remote controller 51 and the sub remote controller 52 used in the embodiment with reference to FIGS. The main remote controller 51 is made of a hard synthetic resin as shown in FIGS. 4 and 5, and a liquid crystal display unit 54 as a display unit is provided on an upper front part of a main body 53 thereof.

The main body 53 is covered by a cover 56 which can be freely opened and closed, and a part of the liquid crystal display section 54 is configured to be visible through a window hole 57 of the cover 56.
A temperature setting switch 58 and a run / stop switch 59 are attached below the window hole 57 of the cover 56, and a human sensor 61 composed of a Fresnel lens F and a pyroelectric sensor (not shown) is provided below the temperature setting switch 58 and the run / stop switch 59. Is attached.

A set temperature and the like are displayed on the liquid crystal display section 54, and the set temperature is indicated by the temperature setting switch 58.
Can be set up / down by the operation. Based on the operation of the run / stop switch 59, the controller 33
Starts and stops the air conditioner AC. Incidentally, reference numeral 62 denotes an infrared light emitting section provided at the upper end of the main body 54. The controller 33 receives the infrared signal from the main remote controller 51 with the receiver 16 of the sensor board 46,
Data such as a set temperature based on the received signal, or set data by a switch or the like provided in the use side unit A itself, a temperature sensor (room temperature sensor) provided inside the main remote controller 51, the room temperature sensor 30 and Based on the outputs of the temperature sensors 34 to 39, the operation (drive) of the fan motors 43 and 44 and the flap motors 41 and 42 of the blower 6 and the blower 7 is controlled,
By transmitting a control signal from the terminal plate 49 to the heat source side unit B to control the compressor 22, the four-way switching valve 23, and the like, the room temperature is adjusted to the set temperature.

On the other hand, various switches for setting the operating state of the air conditioner AC in detail are provided below the liquid crystal display 54 on the front of the main body 53 of the main remote controller 51. In FIG. 5, reference numeral 63 denotes an operation changeover switch.
Is switched to the cooling operation, the heating operation, and the dry operation. The display of each operation state is performed on the liquid crystal display unit 54. 64 and 66 are the flap motors 41 and 4
2 is a wind direction switch for adjusting the angles of the flaps 13 and 14 respectively.
66, "Auto", "Select", "Swing"
The setting is switched by the position. Controller 33
Is set to “automatic”, the flaps 13 and 14
Is controlled to an angle set in advance according to each of the operating states. In “select”, the angle can be adjusted to a desired angle. Furthermore, in the "swing", the flaps 13, 1
4 is made to swing. This display is also displayed on the liquid crystal display unit 54.

Reference numeral 67 denotes a fan motor 4 of the blowers 6 and 7
An air volume switch for setting the air volume blown out of the air outlets 11 and 12 according to the number of rotations of 3, 44. The air volume switch 64 allows the air volume to be “automatic”, “strong”, “medium”,
Can be switched to "weak". The amount of air is also displayed on the liquid crystal display unit 54. Reference numeral 68 denotes a zone switch for executing a zone control operation described later.
Further, reference numeral 69 denotes a switch group for setting a timer reservation operation.

The main remote controller 5 having such a configuration
Numeral 1 is attached to the wall surface of the zone Z1 of the to-be-harmed room 1 (FIG. 7), and transmits data of a temperature sensor incorporated therein and data of each switch to the receiver 16 of the use side unit A by infrared rays.

The human sensor 61 detects a human body motion in the zone Z1 of the room 1 to be conditioned. The main remote controller 51 similarly transmits the detection data of the motion sensor 61 to the receiver 16 by infrared rays.

On the other hand, the sub-remote controller 52 is made of a hard synthetic resin as shown in FIG. 6, and the front thereof has a human sensor 71 having the same structure as described above and whether or not the sub-remote controller 52 is used. An on / off switch 72 for setting is provided, and an infrared light emitting section 73 is provided at the upper end thereof.

The sub remote controller 52 having such a configuration
Is attached to the wall surface of the zone Z2 of the conditioned room 1 (FIG. 7). The human sensor 71 is located in the zone Z of the harmonized room 1.
2, the sub remote controller 52 transmits the detection data of the human sensor 71 to the receiver 16 by infrared rays.

Here, the receiver 16 has two built-in receiving sections, each of which is directed toward the main remote controller 51 and the sub remote controller 52. Then, the controller 33 determines from which remote controller the data is from the difference in the infrared receiving sensitivity.

The present invention is not limited to such a configuration, and one receiving unit may be operated by a stepping motor to identify a remote controller based on a difference in receiving sensitivity.

Next, the zone control operation executed when the zone switch 68 is operated will be described.
By operating the zone switch 68, the zone control operation is executed by the controller 33 in three positions of "zone 1", "zone 2", and "automatic".

Then, when set in "Zone 1",
The controller 33 raises the priority of the air conditioning in the zone Z1, sets the fan motor 43 of the blower 6 to operate at a normal rotation speed, and sets the rotation speed of the fan motor 44 of the blower 7 to low speed (L). As a result, the conditioned air is preferentially blown out mainly from the air outlet 11 toward the zone Z1 of the conditioned room 1, so that when the user is present only in the zone Z1 (living room), it is comfortable. Efficient zone Z1
Air conditioning becomes possible.

When the zone is set to "zone 2", the controller 33 sets the priority of the air conditioning in the zone Z2 to high,
The fan motor 44 of the blower 7 operates at a normal rotation speed, and the rotation speed of the fan motor 43 of the blower 6 is low (L). As a result, the conditioned air is mainly discharged from the outlet 1
2, the air is blown out toward the zone Z2 of the harmonized room 1, so that when the user exists only in the zone Z2 (kitchen), comfortable and efficient air conditioning can be performed.

Further, when "automatic" is set, the controller 33 operates the zones Z1, Z2 by detecting the motion sensors 61, 71 of the remote controllers 51, 52.
The priority of the second air conditioner is determined. That is, the motion sensor 61 of the main remote controller 51 detects a human body motion, and the motion sensor 71 of the sub remote controller 52
When the human body motion is not detected, the priority of the air conditioning in the zone Z1 is increased.

On the other hand, if the motion sensor 61 of the main remote controller 51 does not detect a human body motion and the motion sensor 71 of the sub remote controller 52 detects a human body motion, the air conditioning of the zone Z2 is performed. Higher priority.

Then, both remote controllers 5
When the human motion sensors 61 and 71 of 1 and 52 are detecting a human body motion, no priority is set.

Thus, when one user moves from the zone Z1 to the zone Z2 in the conditioned room 1, air conditioning is automatically preferentially performed toward the zone where the user exists. As a result, the zone where the user is present can be preferentially air-conditioned without setting the zones one by one, and the operability is improved. In addition, when the user exists in both the zone Z1 and the zone Z2 of the harmonized room 1, the priority is automatically canceled, so that the comfort can be further improved.

Next, a protection operation in the air conditioner AC will be described with reference to FIG. The controller 33 of the air conditioner AC of the embodiment executes the freeze prevention control during the cooling operation and the dry operation. During heating operation, heating high load prevention control and fan cold air prevention control,
And the flap heating initial control is executed.

First, the freeze prevention control will be described. That is, the controller 33 takes in the temperature data output by the heat exchange temperature sensors 36 and 37 that detect the temperatures of the use side heat exchangers 3 and 4 during the cooling operation and the dry operation. When the temperature decreases to + 8 ° C., the increase in the capacity (operating frequency Hz) of the compressor 2 is prohibited.
z) is forcibly reduced. When the temperature drops to, for example, + 2 ° C., the compressor 2 is forcibly stopped. Then, when the temperature rises to + 8 ° C. or more, it is released. This prevents the inconvenience that the use-side heat exchangers 3 and 4 are frozen beforehand. In this case, the controller 33 executes the above determination by using the temperature data of the lower temperature. That is, when the temperature of the use side heat exchanger 3 or the use side heat exchanger 4 is lower than that of the use side heat exchanger 4, the temperature data of the heat exchange temperature sensor 36 is adopted. If the temperature is lower than that of the use side heat exchanger 3, the temperature data of the heat exchange temperature sensor 37 is adopted.

Here, the temperature data based on the temperatures of the use side heat exchangers 3 and 4 detected by the heat exchange temperature sensors 36 and 37 are based on the work of each of the blowers 6 and 7, that is, the fan motors for driving them. It depends on the number of rotations of 43 and 44. That is, when the blowers 6 and 7 are working, that is,
When the rotation speeds of the fan motors 43 and 44 are high, the danger of freezing of the use side heat exchangers 3 and 4 is reduced. On the contrary, when the blowers 6 and 7 are not working, that is, the fan motors When the rotation speed of 43 and 44 is low, the danger of freezing of the use side heat exchangers 3 and 4 increases.

Therefore, the controller 33 determines the amount of work of each of the blowers 6, 7 from the sum of the rotation speeds of the two fan motors 43, 44, and when the work is performed, that is, when the sum of the rotation speeds is large. As described above, the temperature + 8 ° C. at which the increase in the capacity of the compressor 2 is prohibited is reduced to, for example, 6 ° C.

On the contrary, when the total number of rotations is small, as described above, the temperature at which the increase in the capacity of the compressor 2 is prohibited is + 8 ° C.
Is reduced, for example, to 10 ° C. The release temperature is also changed to the same value.

With this protection operation, freezing of the use side heat exchangers 3 and 4 can be reliably prevented while the cooling operation of the air conditioner AC is maintained.

Next, the heating high load prevention control will be described. That is, the controller 33 takes in temperature data output from the heat exchange temperature sensors 36 and 37 that detect the temperatures of the use side heat exchangers 3 and 4 during the heating operation. +6 due to clogging
When the temperature rises to 0 ° C, the capacity of the compressor 2 (operating frequency Hz)
Forcefully lower. When the temperature drops below + 60 ° C., the increase in the capacity (Hz) of the compressor 2 is prohibited, and the compressor 2 is released when the temperature further drops.

In this way, the deformation of the resin parts around the use side heat exchangers 3 and 4 is prevented beforehand. In this case, the controller 33 uses the temperature data of the higher temperature to make the above judgment. Execute. That is, the use side heat exchanger 3
If the temperature is higher than that of the use side heat exchanger 4, the temperature data of the heat exchange temperature sensor 36 is adopted, and conversely, the use side heat exchanger 4 or the use side heat exchanger 3 If the temperature is higher than the temperature, the temperature data of the heat exchange temperature sensor 37 is adopted.

With such a protection operation, it is possible to reliably prevent the equipment from being damaged due to the abnormal temperature rise of the use side heat exchangers 3 and 4.

Next, the fan cool air prevention control will be described. That is, the controller 33 captures the temperature data output from the heat exchange temperature sensors 36 and 37 that detect the temperatures of the use side heat exchangers 3 and 4 during the heating operation. In this case, the rotation speeds of the fan motors 43 and 44 of the blowers 6 and 7 are forcibly set to low speed (L). Then, for example, when the temperature reaches + 45 ° C. or higher, it is released. This prevents the cool air from being fed into the conditioned room 1. In this case, the controller 33 performs the above determination by using the temperature data of the higher temperature. That is, when the temperature of the use-side heat exchanger 3 or the use-side heat exchanger 4 is higher than that of the use-side heat exchanger 4, the temperature data of the heat exchange temperature sensor 36 is adopted. If the temperature is higher than that of the use side heat exchanger 3, the temperature data of the heat exchange temperature sensor 37 is adopted.

With this control, it is possible to cancel the fan cool air prevention control when the temperature of any one of the use side heat exchangers 3 and 4 reaches + 45 ° C., and the heating air is sent to the conditioned room 1. Pay can be started earlier to improve comfort.

Next, the flap heating initial control will be described. That is, at the start of the heating operation, the controller 33 takes in the temperature data output from the heat exchange temperature sensors 36 and 37 that detect the temperatures of the use side heat exchangers 3 and 4, for example, when the temperature is +35. If the temperature is lower than 0 ° C., the flap motors 41 and 42 are driven to
The angle of 14 is adjusted, and its tip is pulled up to forcibly increase the air blowing direction.

Then, it is released when the temperature reaches + 35 ° C. This prevents the cool air from being sent around the user. In this case as well, the controller 33 performs the above determination by using the temperature data of the higher temperature. That is, when the temperature of the use-side heat exchanger 3 or the use-side heat exchanger 4 is higher than that of the use-side heat exchanger 4, the temperature data of the heat exchange temperature sensor 36 is adopted.
If the temperature is higher than that of the use side heat exchanger 3, the temperature data of the heat exchange temperature sensor 37 is adopted.

With this control, the flap heating initial control can be canceled when the temperature of any one of the use side heat exchangers 3 and 4 reaches + 35 ° C., and the surroundings of the user in the conditioned room 1 can be released. The supply of heating air to the heater can be started at an earlier point in time to improve comfort.

In the embodiment, two use-side heat exchangers 3,
4 and the case where the blowers 6 and 7 are used have been described,
The same applies to the case where air conditioning is performed using three or more use-side heat exchangers and blowers.

[0060]

As described in detail above, according to the present invention, the compressor, the heat source side heat exchanger, the plurality of use side heat exchangers, etc., and the air which has exchanged heat with each use side heat exchanger are provided. In the air conditioner, each of which blows air into the conditioned room by a plurality of blowers, the air conditioner detects a temperature of the use side heat exchanger, and a compressor and each blower based on an output of the heat exchange temperature sensor. A control device for controlling the operating speed of the compressor, the control device limits the operating speed of the compressor when the temperature of the use side heat exchanger falls below a predetermined value during cooling or dry operation, or The anti-freeze control for stopping the operation is executed, and the predetermined value is changed in accordance with the sum of the operating rotation speeds of the blowers.For example, when the sum of the rotation speeds is large, the predetermined value is changed. Pull down, small place By raising the contrary, while maintaining the cooling effect of the air conditioner, it is possible to reliably prevent icing of the use-side heat exchanger.

[Brief description of the drawings]

FIG. 1 is a sectional view of a use side unit of an air conditioner of the present invention.

FIG. 2 is a refrigerant circuit diagram of the air conditioner of the present invention.

FIG. 3 is an electric circuit diagram of a use side unit of the air conditioner of the present invention.

FIG. 4 is a front view of a main remote controller of the air conditioner of the present invention.

FIG. 5 is a front view of the main controller of FIG. 4 with a cover removed.

FIG. 6 is a front view of a sub remote controller of the air conditioner of the present invention.

FIG. 7 is a diagram showing a conditioned room to which a use side unit of the air conditioner of the present invention is attached.

FIG. 8 is a diagram illustrating a selection operation of a heat exchange temperature sensor in control by the air conditioner of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Harmonized room 3, 4 Use side heat exchanger 6, 7 Blower 9 Suction port 11, 12 Outlet 13, 14, Flap 22 Compressor 24 Heat source side heat exchanger 33 Controller 34, 35 Inlet temperature sensor 36, 37 Heat exchange Temperature sensor 38, 39 Outlet temperature sensor 41, 42 Flap motor 43, 44 Fan motor 46 Sensor board 47, 48 Valve motor 51 Main remote controller 52 Sub remote controller 61, 71 Human sensor A User side unit AC air conditioner B Heat source Side unit F Fresnel lens Z1, Z2 zone

Claims (1)

[Claims] 1. A compressor, a heat source side heat exchanger, a plurality of use side heat exchangers, and the like, wherein air exchanged with each of the use side heat exchangers is introduced into a conditioned room by a plurality of blowers. In an air conditioner that blows out and air-conditions, a heat exchange temperature sensor that detects a temperature of the use side heat exchanger, and a control that controls an operation speed of the compressor and each blower based on an output of the heat exchange temperature sensor. A control unit that limits the operating speed of the compressor or stops the operation when the temperature of the use side heat exchanger falls below a predetermined value during cooling or dry operation. An air conditioner which executes prevention control and changes the predetermined value in accordance with the sum of the operating speeds of the respective blowers.