JP6727312B2 - Air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air conditioner, and more particularly, to blow control of an indoor unit.

In the heating operation of the air conditioner, warm air has a low specific gravity and moves upward, so that the temperature of the floor tends to decrease. Therefore, in the heating operation of the air conditioner up to now, the comfort is enhanced by carrying warm air to the feet by using the fan. Further, in order to further improve comfort during heating, for example, an air conditioner as described in JP 2010-60250 A (Patent Document 1) has been proposed.

The air conditioner described in JP 2010-60250 A controls a blowing direction and a blowing amount at that time according to a position of a person in a room and a user's intention to provide a more efficient and comfortable air-conditioned space. doing.

JP, 2010-60250, A

At present, the air-tightness and heat insulation of houses have advanced, and the heating load tends to decrease. When the heating load is small, the heating capacity is also limited. The air conditioner described in JP 2010-60250 A has the following problems.
(1) When the heating capacity of the indoor heat exchanger is small, the temperature of the blown air decreases when the amount of blown air is secured, so the temperature of the air conveyed to the feet decreases.
(2) When the amount of blown air is reduced, the temperature of the blown air rises, but since the amount of air is small, the cool air at the feet with a high specific gravity blows up the blown air (warm air) with a low specific gravity, and hot air cannot be conveyed to the feet.

The present invention has been made to solve the above problems. An object of the present invention is to provide an air conditioner capable of supplying warm air to the feet by controlling a fan of an air conditioner in order to make the indoor air temperature uniform during a heating operation under a low load. ..

An air conditioner according to the present invention includes a refrigerant circuit, a condensation temperature detection unit, a blower, an air conditioning load detection unit, and a control device. In the refrigerant circuit, the refrigerant circulates in the order of the compressor, the condenser, the expansion mechanism, and the evaporator. The condensing temperature detection unit is configured to detect the condensing temperature that is the refrigerant temperature in the condenser. The blower is configured to regulate the amount of air blown to the condenser. The air conditioning load detection unit is configured to detect the air conditioning load of the air conditioning space. The control device has a first mode and a second mode different from the first mode as operation modes, and is configured to control the amount of air blown by the blower. In the second mode, the control device is configured to operate the blower so as to change the air volume between the first air volume and the second air volume larger than the first air volume according to the change in the condensation temperature. The control device is configured to change the first mode to the second mode when the air conditioning load detected by the air conditioning load detection unit falls below the first threshold value during the first mode.

According to the present invention, a fan intermittent operation (FIO: Fan Intermittent Operation) is performed during a low-load heating operation, thereby destroying a temperature boundary layer formed near the floor and preventing warm air from rising. It can supply warm air to your feet. As a result, it is possible to reduce temperature vibrations at the feet and improve indoor comfort.

It is a figure which shows an example of the air conditioning apparatus 101 in Embodiment 1. It is a figure which shows an example of arrangement|positioning of the structural element of the indoor unit 103. It is a figure which shows an example of the indoor air flow in FIO control in heating operation. 6 is a flowchart showing an example of a control flow in the first embodiment. It is a figure for demonstrating operation mode switching of step S2. It is a figure for demonstrating the change of the operating frequency of the compressor of step S3. FIG. 5 is a diagram showing an example of an operating state of the indoor blower 113 in the first embodiment. It is a figure for explaining change of condensation temperature during fan intermittent operation (FIO). It is the figure which expanded and showed a part of FIG. FIG. 7 is a diagram showing an example of an operation of each unit before and after entering a second mode (FIO) in the first embodiment. FIG. 7 is a diagram showing an example of a control system in the second embodiment. FIG. 16 is a diagram showing an example of an operation of each unit before and after entering a second mode (FIO) in the second embodiment. It is a figure which shows the difference in the timing which enters a 2nd mode (FIO).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Although a plurality of embodiments will be described below, it is planned from the beginning of the application to appropriately combine the configurations described in the embodiments. In the drawings, the same or corresponding parts will be denoted by the same reference symbols and description thereof will not be repeated.

[Embodiment 1]
(Structure of the air conditioner 101)
FIG. 1 is a diagram showing an example of an air conditioning apparatus 101 according to Embodiment 1 of the present invention. As shown in FIG. 1, the air conditioning apparatus 101 includes an indoor unit 103, an outdoor unit 104, and a control device 130.

The indoor unit 103 includes an indoor blower 113, an indoor heat exchanger 115, an infrared sensor 110, a pipe temperature sensor 111, and an indoor temperature sensor 121. The outdoor unit 104 includes an outdoor blower 114, an outdoor heat exchanger 116, an expansion valve 117, a four-way valve 118, and a compressor 119. The outdoor heat exchanger 116, the expansion valve 117, the four-way valve 118, the compressor 119, and the indoor heat exchanger 115 are annularly connected by the refrigerant pipe 120, so that the refrigerant circuit 102 is configured. A heat pump is formed by the refrigerant circulating inside the refrigerant circuit 102 while repeating compression and expansion. The control device 130 controls the four-way valve 118, the compressor 119, the blowers 113 and 114, and the like, so that the air conditioner 101 air-conditions the room in operation modes such as cooling/heating/blowing.

FIG. 1 shows a state in which the four-way valve 118 is set to heating. In this case, in the four-way valve 118, the port H and the port G communicate with each other, and the port E and the port F communicate with each other. The refrigerant flows from the discharge port B of the compressor 119 in the order of the indoor heat exchanger 115, the expansion valve 117, and the outdoor heat exchanger 116, and reaches the suction port A of the compressor 119.

Although not shown, at the time of cooling, in the four-way valve 118, the port H and the port E are in communication, and the port G and the port F are in communication. The refrigerant flows from the discharge port B of the compressor 119 to the outdoor heat exchanger 116, the expansion valve 117, and the indoor heat exchanger 115 in this order, and reaches the suction port A of the compressor 119.

(Structure of indoor unit 103)
FIG. 2 is a diagram showing an example of an arrangement of constituent elements of the indoor unit 103 according to the first embodiment. The indoor unit 103 has an indoor heat exchanger 115, an indoor blower 113, a pipe temperature sensor 111, an infrared sensor 110, and a wind direction plate (louver) 112 arranged inside the main body thereof. The indoor heat exchanger 115 is arranged upstream of the air flow of the indoor blower 113.

The air outlet forms a ventilation path on the downstream side of the indoor blower 113. The direction of the airflow can be adjusted by changing the angle of the wind direction plate (louver) 112 attached to the air outlet.

(Device operation during heating operation)
The indoor space 103 of the air conditioner 101 cools and heats the indoor space by the cool air and warm air. The air conditioning apparatus 101 is equipped with a vapor compression refrigeration cycle, and the indoor unit 103 and the outdoor unit 104 are connected by a refrigerant pipe 120.

The compressor 119 compresses the low temperature/low pressure refrigerant and discharges the high temperature/high pressure refrigerant from the discharge port B. The compressor 119 is driven by an inverter (not shown), and its operating capacity is controlled according to the air conditioning status.

The outdoor heat exchanger 116 performs heat exchange between the cold heat supplied from the refrigerant flowing through the refrigeration cycle and the outdoor air. As described above, the outdoor heat exchanger 116 is supplied with the outdoor air by the outdoor blower 114. The expansion valve 117 is connected between the indoor heat exchanger 115 and the outdoor heat exchanger 116, and decompresses and expands the refrigerant. The expansion valve 117 is composed of a valve whose opening can be variably controlled, such as an electronic expansion valve. The four-way valve 118 is connected to the discharge port B and the suction port A of the compressor 119, and switches the flow of the refrigerant according to the operation (cooling operation, heating operation) of the air conditioning apparatus 101.

(Indoor blower 113, outdoor blower 114)
The outdoor blower 114 is a fan capable of varying the flow rate of air supplied to the outdoor heat exchanger 116, and the indoor blower 113 is capable of varying the flow rate of air supplied to the indoor heat exchanger 115. As these fans, a centrifugal fan or a multi-blade fan driven by a motor such as a DC fan motor can be used.

<Device operation>
In the present embodiment, FIO (Fan Intermittent Operation) control is performed in order to improve comfort at the feet when the heating load is small. The FIO control is control in which a fan generates an air flow that delivers warm air to the feet. In the following description, the operation mode in which the air volume is determined by the user's settings such as the remote control is referred to as the normal operation mode (hereinafter referred to as the first mode (FCO: Fan Common Operation)), and when the air conditioning load is low, The operation mode in which the fan is operated intermittently is referred to as an intermittent operation mode (hereinafter, second mode (FIO)).

FIG. 3 is a diagram showing an example of an indoor air flow under FIO control in the heating operation according to the first embodiment. Referring to FIGS. 1 to 3, when the heating load in air-conditioned space R is small, control device 130 changes the angle of wind direction plate (louver) 112 to make the blowing direction of indoor unit 103 downward. ..

When the condensation temperature CT detected by the pipe temperature sensor 111 installed in the indoor heat exchanger 115 is equal to or higher than a certain value (T1), the control device 130 starts the operation of the indoor blower 113 at the fan rotation speed (N2). .. When the condensation temperature CT detected by the pipe temperature sensor 111 becomes lower than a certain value (T2), the control device 130 stops the indoor blower 113 or operates with a low air volume. At this time, the control device 130 continues the operation of the compressor 119 regardless of the operation of the indoor blower 113.

Therefore, if the surface temperature of the indoor heat exchanger 115 rises and the condensation temperature detected by the pipe temperature sensor 111 reaches a certain value (T1) or more again while the indoor blower 113 is stopped or is operating at a low air volume, The indoor blower 113 restarts the operation at the rotation speed (N2).

<Control operation>
The operation of the air conditioner configured as described above will be described using a flowchart. FIG. 4 is a flowchart showing an example of a control flow in the first embodiment of the present invention. The control device 130 that executes the processing of this flowchart can be realized by hardware such as a circuit device that realizes these functions, or can be read from a memory by an arithmetic device such as a microcomputer or a CPU and executed by the arithmetic device. It can also be implemented as software.

Referring to FIG. 4, when the process of this flowchart is started, first, in step S1, control device 130 detects air conditioning load Q (kW). For example, when determining whether the air conditioning load Q is lower than a predetermined value Q2, the surface temperature of an object (wall, floor, person, etc.) existing in the air conditioned space can be used as a standard.

The air conditioning load detection unit 125 detects the surface temperature (radiation temperature Tr) of an object existing in the air conditioned space by the infrared sensor 110. Control device 130 changes the first mode (FCO) to the second mode (FIO) when the surface temperature is lower than the first threshold value (YES in S2).

In another example, the air conditioning load Q is estimated based on the indoor radiation temperature Tr detected by the infrared sensor 110 shown in FIG. The infrared sensor 110 may detect the radiation temperatures Tr at a plurality of places in the room, and in such a case, a weighted average value can be used. For example, the relationship between the radiation temperature Tr and the air conditioning load Q may be set in a predetermined map, and the air conditioning load Q may be obtained from the radiation temperature Tr by referring to the map in step S1.

Furthermore, when estimating the air conditioning load Q, the temperature difference between the outside air temperature and the room temperature, the difference between the floor surface temperature or the room temperature and the set temperature, the amount of solar radiation, the room temperature, etc. may be taken into consideration.

Subsequently, in step S2, the control device 130 determines whether or not the air conditioning load Q is lower than the predetermined value Q2 (Q<Q2). When Q<Q2 is satisfied in step S2 (YES in S2), the process proceeds to step S3, and when not satisfied (NO in S2), the process proceeds to step S14.

FIG. 5 is a diagram for explaining the operation mode switching in step S2. Referring to FIG. 5, the air conditioning apparatus 101 enters the second mode (FIO) under the condition that the air conditioning load Q estimated using the radiation temperature by the infrared sensor 110 is lower than the predetermined value Q2 (Q<Q2). It is a condition. The condition that the air conditioning load Q is lower than the predetermined value Q1 (Q< Q1 ) is a condition for stopping the compressor.

In this way, by comparing the air conditioning load Q with the predetermined value Q2 that is the determination value, the control device 130 switches the operation mode between the second mode (FIO) and the first mode (FCO) as appropriate.

In addition, in the example of FIG. 1, the air conditioning load detection unit 125 determines the air conditioning load based on the surface temperature or the radiation temperature in the room, but the air conditioning load may be determined based on the rotation speed of the compressor 119. good. In this case, the air conditioning load detection unit 125 detects the rotation speed of the compressor 119, and the control device 130 determines that the rotation speed of the compressor 119 is lower than the first threshold value (the lower limit set value F1 for normal operation). Then, the first mode (FCO) is changed to the second mode (FIO).

When the process proceeds from step S2 to step S3, control device 130 also changes the operating frequency of compressor 119. FIG. 6 is a diagram for explaining changes in the operating frequency of the compressor in step S3. With reference to FIGS. 4 and 6, in step S3, control device 130 sets the operating frequency of the compressor to operating frequency F2 that is approximately half the lower limit frequency F1 in normal operation. That is, when the first mode (FCO) is changed to the second mode (FIO) at time t1, the operating frequency of the compressor 119 is from the frequency F1 which is the lower limit set value in the normal operation to the frequency F2 which is about half of the frequency F1. Changes to. Further, if the air conditioning load Q is equal to or more than the predetermined value Q2 in step S2, the operation mode shifts to the first mode (FCO), so that the operating frequency returns to the frequency F1 at time t2.

Further, in step S3, the control device 130 changes the blowing direction of the indoor blower 113 at the same time as changing the operating frequency of the compressor 119. In order to change the blowing direction, the air conditioning apparatus 101 includes a wind direction plate (louver) 112. Then, when the mode is the second mode (FIO), control device 130 controls airflow direction plate 112 such that the airflow direction is a predetermined airflow direction (corresponding to angle θ2).

The control device 130 sets the angle θ of the wind direction plate (louver) 112 to the arbitrary angle θ1 set by the user in the first mode (FCO), but changes it to the angle θ2 in the second mode (FIO). Here, as shown in FIG. 2, if the angle θ of the wind direction plate (louver) 112 is 90° in the vertical direction with respect to the floor surface and 0° in the horizontal direction, the angle θ2 indicating a predetermined wind direction is 45° or more. Is. Preferably, the angle θ2 is in the range of 60 to 85°.

After step S3, a process of intermittently operating the indoor blower 113 is executed in steps S4 to S10.

7: is a figure which shows an example of the operating state of the indoor blower 113 in Embodiment 1. FIG. During the heating low capacity operation of the air conditioner, the angle θ of the wind direction plate (louver) 112 is set downward, and the air volume is intermittently increased or decreased between the first air volume and the second air volume as shown from time t1 to t2. The fan rotation speed is set to the rotation speed N2 and 0 (rpm), and the timing of switching the rotation speed from N2 to 0 and the timing of switching from 0 to N2 are determined based on the condensation temperature CT of the indoor heat exchanger 115. To be done.

In the example shown in FIG. 7, the second air volume is the air volume corresponding to the rotation speed N2, and the first air volume is the air volume (air volume=0) corresponding to the state where the indoor blower 113 is stopped. However, the first air volume may be smaller than the second air volume, and may not necessarily be zero.

FIG. 8 is a diagram for explaining changes in the condensation temperature during the second mode (FIO). Two types of temperature T1 and temperature T2 are set as the determination value of the condensation temperature CT for operating/stopping the indoor blower 113. During the second mode (FIO), the condensation temperature CT changes up and down between the temperature T1 and the temperature T2. The indoor blower 113 stops at the rising time tr, and the indoor blower 113 operates at the falling time tf.

FIG. 9 is an enlarged view of a part of FIG. 8. While the indoor blower 113 is stopped, the condensation temperature CT of the indoor heat exchanger 115 rises from T2 to T1.

At time t3, when the condensation temperature CT reaches the temperature T1, the indoor blower 113 starts operating. During the operation of the indoor blower 113 from time t3 to t4, the indoor heat exchanger 115 is cooled by the air blow, so the condensation temperature CT decreases from T1 to T2. At time t4, when the condensation temperature CT drops to the temperature T2, the indoor blower 113 stops. After that, the operation start and the operation stop of the indoor blower 113 are repeated at times t5 and t6.

As shown in FIG. 9, in the second mode (FIO), when the condensation temperature CT becomes higher than the first temperature T1, the control device 130 changes the blowing amount of the indoor blower 113 from the first blowing amount (fan rotation speed= 0 ) to the first blowing amount. Change to 2 air volume (fan rotation speed = N2 ). Further, when the condensing temperature CT becomes lower than the second temperature T2 (<T1), the control device 130 changes the air flow rate of the indoor blower 113 from the second air flow rate (fan rotation speed= N2 ) to the first air flow rate (fan rotation speed= 0 ). change.

The blower fan ON/OFF control based on the condensation temperature is executed in steps S4 to S10 in FIG. Hereinafter, returning to FIG. 4 again, the control will be described.

In step S4 following step S3, the control device 130 detects the condensation temperature CT by the pipe temperature sensor 111.

Subsequently, in step S5, the control device 130 determines whether or not the indoor blower 113 is in operation (=ON). In step S5, if the indoor blower 113 is ON (YES in S5), the process proceeds to step S6, and if the indoor blower 113 is OFF (NO in S5), the process proceeds to step S8. ..

In step S6, control device 130 determines whether or not condensation temperature CT measured using pipe temperature sensor 111 is lower than predetermined value T2. When CT<T2 is satisfied in step S6 (YES in S6), the control device 130 stops the indoor blower 113 in step S7 and advances the process to step S10. When CT<T2 is not satisfied in step S6 (NO in S6), control device 130 advances the process to step S10 without executing the process of step S7.

On the other hand, in step S8, the control device 130 determines whether or not the condensation temperature CT measured using the pipe temperature sensor 111 is higher than the predetermined value T1. When CT>T1 is satisfied in step S8 (YES in S8), the control device 130 operates the indoor blower 113 in step S9 and advances the process to step S10. When CT>T1 is not satisfied in step S8 (NO in S8), control device 130 advances the process to step S10 without executing the process of step S9.

In step S10, the control device 130 detects the room temperature Ta by the indoor temperature sensor 121. When the room temperature Ta is higher than the predetermined value Ta_min (YES in S11), the control device 130 advances the process to step S12. When the room temperature Ta is lower than the predetermined value Ta_min (NO in S11), the control device 130 advances the process to step S14.

In step S12, the control device 130 detects the sensible temperature Ta_t of the human body. As a measure of the sensible temperature, it is possible to measure the surface temperature in the room using the infrared sensor 110 and use this as the sensible temperature Ta_t.

When the sensible temperature Ta_t is higher than the predetermined value Ta_set (YES in S13), the control device 130 returns the process to step S1 and repeats the above-described operation. When the sensible temperature Ta_t is lower than the predetermined value Ta_set (NO in S13), the control device 130 advances the process to step S14. In step S14, the control device 130 sets the operation mode to the first mode (FCO) and causes the air conditioner 101 to operate normally.

The normal operation executed in the first mode may be different from the indoor fan intermittent operation in which the processes of steps S3 to S13 are repeated, and various processes can be performed as long as the process controls the air volume and the room temperature. Driving is assumed.

In steps S11 and S13, it is determined whether the operation mode is switched from the second mode to the first mode. That is, the air conditioning load detection unit 125 of FIG. 1 includes the infrared sensor 110 that detects the surface temperature of an object existing in the air conditioned space, and the indoor temperature sensor 121 that detects the indoor temperature. The controller 130 operates under the first condition that the indoor temperature Ta is lower than the second threshold value Ta_min and the surface temperature (sensible temperature Ta_t) is lower than the third threshold value Ta_set during the operation in the second mode (FIO). When at least one of the second condition of being low is satisfied, the operation mode is changed from the second mode (FIO) to the first mode (FCO).

FIG. 10 is a diagram showing an example of the operation of each part before and after entering the second mode (FIO) in the first embodiment. At times t0 to t1, the normal operation (FCO) during heating is executed. At this time, the rotation speed of the indoor blower 113 is the rotation speed N1 determined by the user's setting.

When the normal operation (FCO) is changed to the low load operation (FIO) at time t1, the rotation speed N of the indoor blower 113 is intermittently switched between 0 and N2, and the wind direction plate (louver) 112 is set to a normally set arbitrary value. The angle θ1 changes to a predetermined angle θ2 (=60 to 85°), and the operating frequency of the compressor 119 becomes approximately half the frequency F2 from the frequency F1 corresponding to the lower limit value of the normal operation.

In this way, by controlling the indoor blower 113 intermittently while fixing the operating frequency of the compressor 119, the intrinsic temperature boundary layer of air formed near the floor is destroyed, and warm air is prevented from rising. , Reduce the vibration of the foot temperature.

The air conditioner 101 according to Embodiment 1 will be summarized with reference to FIG. 1 and the like again. The air conditioning apparatus 101 includes a refrigerant circuit 102, a pipe temperature sensor 111, an indoor blower 113, an air conditioning load detection unit 125, and a control device 130. During heating in the refrigerant circuit 102, the refrigerant circulates in the order of the compressor 119, the indoor heat exchanger 115 acting as a condenser, the expansion valve 117, and the outdoor heat exchanger 116 acting as an evaporator. The pipe temperature sensor 111 is configured to detect the condensation temperature CT that is the refrigerant temperature in the indoor heat exchanger 115. The indoor blower 113 is configured to adjust the heat radiation amount of the indoor heat exchanger 115. The air conditioning load detection unit 125 is configured to detect the air conditioning load of the air conditioning space.

As represented by the flowchart of FIG. 4 and the waveform diagram of FIG. 10, the control device 130 has a first mode (FCO) and a second mode (FIO) different from the first mode as operation modes, It is configured to control the amount of air blown from the indoor blower 113. In the second mode, the control device 130 controls the indoor blower 113 to change the air volume between the first air volume (zero) and the second air volume (N2) larger than the first air volume in accordance with the change of the condensation temperature CT. Configured to drive. As shown in FIG. 5, when the air conditioning load Q detected by the air conditioning load detecting unit 125 is lower than the first threshold value Q2 during the first mode, the control device 130 is in the first mode (FCO). To a second mode (FIO).

The following effects (1) to (3) are obtained by the air conditioning apparatus 101 according to the first embodiment.
(1) By stopping the fan and raising the condensing temperature, it is possible to raise the blow-out temperature even at low frequency operation of the compressor. Also, warm air can be supplied to the feet when the fan is restarted.
(2) By directing the wind direction plate downward, it is possible to make the blowing direction of warm air at the feet. Further, due to the temperature difference between the blown warm air and the air in the room, the warm air is sent to the feet and then moves from the bottom to the top. Therefore, the indoor temperature can be made uniform even when the compressor is operated at a low frequency.
(3) Even if the operating frequency of the compressor is low, the room temperature can be kept uniform, so that start/stop of repeating the operation/stop of the compressor is suppressed, and an energy saving effect can be expected.

[Second Embodiment]
The second embodiment of the present invention will be described below. The air conditioner according to Embodiment 2 includes a control device that controls a plurality of indoor units 103 to set the indoor temperature of the air-conditioned space R to the target temperature. The control of the load detection means, the temperature detection means, the air flow control means, and the wind direction control means of each indoor unit 103 is the same as that in the first embodiment, and therefore illustration and description thereof are omitted.

FIG. 11 is a diagram showing an example of the control system in the second embodiment. The indoor units 103A, 103B, 103C are connected to the central control device 230 by communication devices 203, 204, 205, respectively. It is possible to control the indoor units 103A, 103B, 103C from the centralized control device 230. The connection between the indoor units 103A, 103B, 103C and the communication devices 203, 204, 205 and the connection between the communication devices 203, 204, 205 and the central control device 230 may be wired or wireless, and control commands and device information are mutually exchanged. You can send it to.

FIG. 12 is a diagram showing an example of the operation of each part before and after entering the second mode (FIO) in the second embodiment. Control of the load detection means, the temperature detection means, the air flow control means, and the wind direction control means of the indoor units 103A, 103B, and 103C is the same as that of the first embodiment, as shown in FIG. However, the second embodiment is characterized in that the indoor units 103A, 103B, 103C enter the second mode (FIO) at slightly different timings.

FIG. 13 is a diagram showing a difference in timing of entering the second mode (FIO). As shown in FIG. 13, the timing at which the indoor unit 103B enters the second mode (FIO) is delayed by the time difference FIOΔT from the timing at which the indoor unit 103A enters the second mode (FIO). When the time difference, the fan rotation speed, and the settings of the temperatures T1 and T2 are adjusted, warm air is blown out from the other indoor units 103B or 103C during the fan stop time of the indoor unit 103A.

That is, in the second embodiment, as schematically shown in FIG. 11, indoor heat exchanger 115 includes a first condenser 115A and a second condenser 115B that are connected in parallel with each other in the refrigerant circuit. The indoor blower 113 includes a first blower 113A and a second blower 113B provided corresponding to the first condenser 115A and the second condenser 115B, respectively. As shown in FIG. 13, in the central control device 230, in the second mode (FIO), the period in which the first blower 113A blows the first air amount (fan rotation speed N2A) and the second blower 113B outputs the second air amount (fan). The first blower 113A and the second blower 113B are controlled so that the period for blowing the rotation speed N2B) does not overlap. Although not shown, the indoor unit 103C is also provided with a condenser and a blower.

By controlling in this way, air is blown alternately from the blowers of the plurality of indoor units, so that warm air is constantly supplied to the feet, and temperature vibration near the floor surface can be suppressed.

It should be considered that the embodiments disclosed this time are exemplifications in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

101 air conditioner, 103, 103A, 103B, 103C indoor unit, 104 outdoor unit, 110 infrared sensor, 111 piping temperature sensor, 113 indoor blower, 114 outdoor blower, 115 indoor heat exchanger, 116 outdoor heat exchanger, 117 expansion Valves, 118 four-way valves, 119 compressors, 120 refrigerant pipes, 121 indoor temperature sensors, 130 control devices, 230 centralized control devices, 203 communication devices.

Claims (7)

The refrigerant, a refrigerant circuit that circulates in the order of the compressor, the condenser, the expansion mechanism, and the evaporator,
A condensing temperature detector configured to detect a condensing temperature that is a refrigerant temperature in the condenser;
A blower configured to adjust the amount of air blown to the condenser,
An air conditioning load detector configured to detect the air conditioning load,
A first mode and a second mode different from the first mode as operation modes during heating operation , and a control device configured to control the air flow rate of the blower,
In the second mode, the control device is configured to operate the blower so as to change the air volume between the first air volume and the second air volume larger than the first air volume according to the change in the condensation temperature. Is
The control device changes the operation mode from the first mode to the second mode when the air conditioning load detected by the air conditioning load detection unit falls below a threshold value during the first mode. Is configured to
In the second mode, when the condensation temperature becomes higher than a first temperature, the control device changes the air flow rate of the blower from the first air flow rate to the second air flow rate, which is lower than the second temperature lower than the first temperature. Also, when the condensation temperature becomes low, the air conditioner that changes the air flow rate of the blower from the second air flow rate to the first air flow rate. The air conditioning load detection unit,
A surface temperature detection unit for detecting the surface temperature of an object existing in the air-conditioned space,
Including an indoor temperature detection unit that detects the indoor temperature,
The controller has at least a first condition that the room temperature is lower than a first threshold value and a second condition that the surface temperature is lower than a second threshold value during the operation in the second mode. The air conditioner according to claim 1, wherein when one of the conditions is established, the operation mode is changed from the second mode to the first mode. The air conditioning load detection unit detects the rotation speed of the compressor,
The air conditioner according to claim 1, wherein the control device changes the operation mode from the first mode to the second mode when the rotation speed of the compressor is lower than a first threshold value. .. An air flow direction changing unit that changes the air flow direction of the blower is provided,
The air conditioner according to claim 1, wherein the control device controls the airflow direction changing unit so that the airflow direction becomes a predetermined airflow direction when the operation mode is the second mode. The air conditioner according to claim 4, wherein the angle indicating the predetermined wind direction is 45° or more when the angle indicating the vertical direction is 90° and the angle indicating the horizontal direction is 0° with respect to the floor surface. apparatus. The air conditioner,
An additional condenser connected in parallel to the condenser in the refrigerant circuit,
And an additional blower provided corresponding to the additional condenser,
In the second mode, the control device includes the blower and the additional blower so that a period in which the blower blows the second air amount does not overlap with a period in which the additional blower blows the second air amount. The air conditioner according to claim 1, which controls the air conditioner. The air conditioner according to claim 1, wherein the first air volume is an air volume corresponding to a state in which the blower is stopped.

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