WO2003083377A1

WO2003083377A1 - Air conditioner

Info

Publication number: WO2003083377A1
Application number: PCT/JP2003/002609
Authority: WO
Inventors: Hidehiko Kataoka; Mitsuaki Nagamine
Original assignee: Daikin Industries, Ltd.
Priority date: 2002-03-28
Filing date: 2003-03-05
Publication date: 2003-10-09
Also published as: AU2003211720B2; AU2003211720A1; EP1491826B1; CN1643305A; JP3778117B2; EP1491826A4; EP1491826A1; JP2003287258A; CN1284951C; ES2598355T3

Abstract

An air conditioner (1) in which indoor temperature can be detected accurately even in the case of an indoor unit in a thermostat-off state while suppressing abrupt lowering of supply air temperature in an operating room. The air conditioner (1) comprises a plurality of indoor units (3a-3d), an outdoor unit (2), and an outdoor control section (25). Each indoor unit (3a-3d) comprises a room temperature thermistor (33a-33d), an indoor heat exchanger, an indoor fan (32a-32d) and an indoor control section (34a-34d). The outdoor unit (2) comprises an outdoor heat exchanger and constitutes a refrigerant circuit with the plurality of indoor units (3a-3d). The indoor control section (34a-34d) makes a decision whether the conditions for starting room temperature monitoring by the room temperature thermistor (33a-33d) are satisfied or not and drives the indoor fan (32a-32d) if room temperature is monitored at the time of thermostat-off of heating operation. The outdoor control section (25) selects a specified indoor unit from among the plurality of indoor units (3a-3d) and transmits a signal concerning permission of room temperature monitoring to the indoor control section of a selected indoor unit. Furthermore, the indoor control section (34a-34d) makes a decision whether the room temperature monitoring is performed or not based on that signal and the conditions for starting room temperature monitoring.

Description

Description Air conditioner (Technical field)

The present invention relates to an air conditioner, particularly to a multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit.

(Background technology)

There is a so-called multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit. A multi-room air conditioner can perform air conditioning in a plurality of rooms by arranging indoor units in a plurality of rooms. In this multi-room air conditioner, not all of the indoor units are always operating, and some of the indoor units are operating and other indoor units are not operating, or It may be in the thermo-off state. In this case, it is considered that there is no need to circulate the refrigerant in the indoor unit that is stopped or in the thermo-off state. However, in indoor units in which the heating operation is stopped or the thermostat is off, a very small amount of refrigerant is often flowed in order to suppress the occurrence of problems due to liquid pools.

By the way, many air conditioners are equipped with a room temperature sensor and have a room temperature monitoring function for detecting the room temperature. As a result, the components of the air conditioner can be controlled, and the room can be controlled to a comfortable temperature. When this room temperature monitoring is performed, the room temperature may be detected by taking indoor air into the indoor unit to prevent the room temperature sensor of the indoor unit in the thermo-off state from being affected by the temperature of the indoor heat exchanger. Therefore, when monitoring the room temperature, the indoor fan is driven even in the indoor unit in the thermo-off state. As a result, the room temperature can be detected more accurately. Here, in the multi-room air conditioner described above, each indoor unit often determines the start of room temperature monitoring independently. For example, each indoor unit measures the time with a timer and monitors the room temperature at regular time intervals, such as once every 5 minutes. In such a multi-room air conditioner, the indoor fans may be simultaneously driven in a plurality of indoor units in a thermo-off state. In this case, there is a problem that the blow-out temperature drops sharply in the cab for the following reasons. That is, in the above-described multi-room air conditioner, since the refrigerant flows even in the thermo-off state, when the indoor fan is driven, the refrigerant condenses. If this occurs simultaneously in multiple indoor units, a sharp drop in pressure will occur in the cab. For this reason, a phenomenon in which the blow-out temperature drops rapidly in the operator's room is likely to occur. Also, in a refrigerant circuit that circulates at a fixed refrigerant amount, when the indoor fans suddenly start to be driven by a plurality of indoor units, the amount of heat dissipated increases as a whole. As a result, the amount of heat dissipated in the cab is reduced, and the outlet temperature is reduced.

(Disclosure of the Invention)

An object of the present invention is to provide an air conditioner that can accurately detect the indoor temperature even in an indoor unit in a thermo-off state while suppressing a sharp drop in the blowout temperature in an operating room.

The air conditioner according to claim 1 includes a plurality of indoor units, an outdoor unit, and a room temperature monitoring control unit. Each indoor unit has a room temperature sensor, an indoor heat exchanger, an indoor fan, and an indoor control unit. The outdoor unit has an outdoor heat exchanger, and forms a refrigerant circuit with a plurality of indoor units. The indoor control unit determines whether or not the start condition of the room temperature monitoring by the room temperature sensor is satisfied, and drives the indoor fan when the room temperature monitoring is performed when the heating operation is turned off. The room temperature monitoring controller selects a predetermined indoor unit from the plurality of indoor units, and transmits a signal regarding permission of room temperature monitoring to the indoor controller of the selected indoor unit. In addition, the indoor control unit determines whether or not to perform room temperature monitoring based on both the above signal and the room temperature monitoring start condition.

In this air conditioner, the indoor control unit determines whether to perform room temperature monitoring based on both the signal received from the room temperature monitoring control unit and the start condition of room temperature monitoring. For this reason, this air conditioner can limit the number of indoor units that perform room temperature monitoring simultaneously from the room temperature monitoring control unit. Therefore, at the same time , The number of indoor fans to be driven can be limited. As a result, in this air conditioner, it is possible to accurately detect the indoor temperature even in the thermo-off state indoor unit while suppressing a sharp drop in the outlet temperature in the operating room.

The invention according to claim 2 is the air conditioner according to claim 1, wherein the signal is a room temperature monitoring permission signal that permits room temperature monitoring. Then, the indoor control unit performs room temperature monitoring when the room temperature monitoring permission signal is received and the start condition of the room temperature monitoring is satisfied.

In this air conditioner, the indoor control unit receives the room temperature monitoring permission signal, and performs room temperature monitoring when the start condition of the room temperature monitoring is satisfied. Therefore, even if a certain indoor control unit determines that the conditions for starting room temperature monitoring are satisfied based on the conditions inside the indoor unit, room temperature monitoring is performed until the room temperature monitoring control unit permits room temperature monitoring. Absent. Therefore, the number of indoor units that perform room temperature monitoring at the same time can be limited by the room temperature monitoring control unit. As a result, in this air conditioner, it is possible to accurately detect the indoor temperature even in the indoor unit in the thermo-off state while suppressing a sharp decrease in the outlet temperature in the operating room.

The invention according to claim 3 is the air conditioner according to claim 2, wherein the room temperature monitoring control unit transmits a room temperature monitoring permission signal at a different time for each indoor control unit.

In this air conditioner, the room temperature monitoring permission signal is transmitted to each indoor control unit with a time lag, so that two or more indoor units do not perform room temperature monitoring at the same time. For this reason, in this air conditioner, it is possible to further suppress a sharp drop in the outlet temperature in the operating room.

The invention according to claim 4 is the air conditioner according to any one of claims 1 to 3, wherein the room temperature monitoring control unit transmits the signal at an equal timing to each of the indoor control units. To send.

In this air conditioner, the room temperature monitoring control unit transmits a signal to each of the indoor control units at an equal timing. This gives each indoor unit an opportunity to perform room temperature monitoring evenly. This enables monitoring of the room temperature of each indoor unit The occurrence of bias in the number of rings can be suppressed.

The invention according to claim 5 is the air conditioner according to any one of claims 1 to 4, wherein the room temperature monitoring control unit is an air conditioner of the indoor unit that is in a thermo-off state of the heating operation among the plurality of indoor units. The above signal is transmitted only to the indoor control unit.

In this air conditioner, the room temperature monitoring control unit transmits a signal only to the indoor control unit of the indoor unit that is in the thermo-off state of the heating operation. For this reason, the probability that the indoor unit loses the opportunity for monitoring is lower than when the signal is transmitted to the indoor control units of all the indoor units.

The invention according to claim 6 is the air conditioner according to any one of claims 1 to 4, wherein the room temperature monitoring control unit transmits a signal to all indoor units. In this air conditioner, the room temperature monitoring control unit transmits a signal to all indoor units. For this reason, the room temperature monitoring control unit does not need to determine whether the indoor unit is in the thermo-off state. This simplifies the control and reduces the load on the room temperature monitoring controller.

(Brief description of drawings)

Fig. 1 is an external view of the air conditioner.

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

FIG. 3 is a control block diagram of the air conditioner.

FIG. 4 is a diagram showing the relationship between the timers.

FIG. 5 is a diagram showing a specific example of each timer.

FIG. 6 is a diagram showing a timer when one of the indoor units is turned off.

(Best mode for carrying out the invention)

FIG. 1 shows an air conditioner 1 employing an embodiment of the present invention.

The air conditioner 1 is a so-called multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit. ·

This air conditioner 1 has four indoor units 3 a, 3 b, 3 c, and one outdoor unit 2. 3d is connected by refrigerant pipes 4a, 4b, 4c and 4d, respectively. These four indoor units 3a, 3b, 3c, 3d are arranged in separate rooms. FIG. 2 schematically shows the refrigerant circuit of the air conditioner 1.

The refrigerant circuit includes one outdoor unit 2 and four indoor units 3 a, 3 b, 3 c, and 3 d connected in parallel to the outdoor unit 2.

The indoor unit 3a includes an indoor heat exchanger 30a, an electric valve 31a, an indoor fan 32a, a room temperature thermistor 33a, and an indoor control unit 34a (see Fig. 3). ing. The indoor heat exchanger 30a and the electric valve 31a are connected in series, and constitute a refrigerant circuit with the outdoor unit 2. The motor-operated valve 31a is provided on the outlet side of the indoor heat exchanger 30a and adjusts the amount of refrigerant flowing through the indoor heat exchanger 30a.

The room fan 32a is provided in the indoor unit 3a, and is driven by the indoor control unit 34a. The indoor fan 32a takes in the indoor air in which the indoor unit 3a is arranged into the interior of the indoor unit 3a, and sends the air subjected to the heat exchange by the indoor heat exchanger 30a to the indoor.

The room temperature thermistor 33a is provided inside the indoor unit 3a, detects the indoor temperature, and transmits a detection signal to the indoor control unit 34a.

The indoor control unit 34a includes a microprocessor, a ROM, a RAM, various interfaces, and the like. As shown in Fig. 3, the indoor control section 34a is connected to the electric valve 31a, the indoor fan 32a, and the room temperature thermistor 33a, and receives the detection signal of the room temperature thermistor 33a. You. The indoor control unit 34a transmits a control signal to the motor-operated valve 31a to adjust the opening. Further, the indoor control unit 34a drives the indoor fan 32a when performing room temperature monitoring described later in a state where the thermostat is off.

The outdoor unit 2 includes a compressor 20, a four-way switching valve 21, an outdoor heat exchanger 22, an accumulator 23, a discharge pipe thermistor 24, an outdoor control unit 25 (see FIG. 3), and the like. The compressor 20, the four-way switching valve 21, the outdoor heat exchanger 22, and the accumulator 23 constitute a refrigerant circuit between the indoor unit and the four-way switching valve 21. The flow of the refrigerant is switched at different times. The discharge pipe thermistor is mounted on the discharge side of the compressor 20 and detects the temperature of the discharge pipe on the discharge side of the compressor 20.

The outdoor control unit 25 includes a microprocessor, a ROM, a RAM, various interfaces, and the like. As shown in FIG. 3, the outdoor control unit 25 is connected to a discharge pipe thermistor 24, and receives a detection signal of the discharge pipe thermistor 24. Further, the outdoor control unit 25 controls the air conditioning operation by controlling the operation frequency of the compressor 20 according to various conditions during operation. In addition, the outdoor control unit 25 determines the opening degree based on the discharge pipe temperature for the electrically operated valve of the indoor unit that is operating, and determines the opening of the electrically operated valve of the indoor unit that is not operating. The opening is determined to a value proportional to the opening of the motor-operated valve of the machine.

A transmission line 40a is provided between the outdoor control unit 25 and the indoor control unit 34a, and a control signal for the motor-operated valve 31a is transmitted through the transmission line 40a. It is possible to transmit and receive various signals such as signals related to permission to monitor room temperature.

The other indoor units 3b, 3c, 3d have the same configuration as the indoor unit 3a, and are connected to the outdoor unit 2. In FIGS. 2 and 3, the same components are shown with the symbols replaced. For example, the motorized valve 31a of the indoor unit 3b is expressed as the motorized valve 31b of the indoor unit 3b.

In this air conditioner 1, the room temperature monitor detects the room temperature periodically by the room temperature thermistors 33a, 33b, 33c, 33d in the indoor units 3a, 3b, 3c, 3d. A ring is performed. For example, the air conditioner 1 monitors the room temperature of the indoor unit in a thermo-off state, and detects the room temperature of the room where the indoor unit is arranged. When determining that the room temperature has dropped to a certain value, the indoor control unit 25 performs control to turn on the thermostat.

In the air conditioner 1, when the heating operation is being performed, and when monitoring the room temperature in the indoor unit in the thermo-off state, the indoor control unit of the indoor unit drives the indoor fan to control the room temperature. Is detected. In this way, when the indoor fan is driven during room temperature monitoring, room temperature monitoring is performed on the air taken in from the room. Therefore, the room temperature thermistor is affected by the heat of the indoor heat exchanger. Can be reduced. This enables accurate room temperature detection.

When the indoor fan is driven by the indoor unit in the thermo-off state at the same time in multiple indoor units, the pressure drop due to refrigerant condensation occurs rapidly, and the blowout temperature of the indoor unit in the operating room sharply increases. A phenomenon of decline occurs.

In the air conditioner 1, in order to suppress the occurrence of such a phenomenon, the room temperature monitoring is controlled so that the room temperature monitoring by the indoor unit in the thermo-off state does not start simultaneously in a plurality of indoor units. The following describes this control. <Room temperature monitoring control>

First, the outline of the room temperature monitoring control will be described.

The outdoor control unit 25 selects an indoor unit for performing room temperature monitoring, and transmits a room temperature monitoring permission signal to the indoor control unit of the selected indoor unit. At this time, the outdoor control unit 25 transmits the room temperature monitoring permission signal with a time lag between the indoor control units 34a, 34b, 34c, and 34d.

Each of the indoor control units 34a, 34b, 34c, 34d determines whether or not the conditions for starting room temperature monitoring are satisfied. The conditions for starting this room temperature monitoring are determined independently by each indoor unit 3a, 3b, 3c, 3d. The indoor control units 34a, 34b, 34c, and 34d receive the room temperature monitoring permission signal from the outdoor control unit 25 and perform room temperature monitoring when the start condition of the room temperature monitoring is satisfied. I do.

Next, the room temperature monitoring control of the outdoor control unit 25 will be described in detail.

[Control start conditions]

First, the outdoor control unit 25 determines whether to start room temperature monitoring control on the outdoor unit 2 side.

The outdoor control unit 25 starts the room temperature monitoring control when both of the following two conditions are satisfied.

(1) Air conditioner 1 is in heating operation.

(2) Air conditioner 1 is not defrosting. [Start setting of room temperature monitoring timer for each indoor unit]

Next, as shown in Fig. 4, various room temperature monitoring timers are set and started for each indoor unit 3a, 3b, 3c, 3d. Here, Tm2 (A) represents a room temperature monitoring permission timer that counts the time during which the indoor unit 3a is permitted to monitor the room temperature. The other indoor units 3b, 3c, and 3d are shown by replacing the symbols in parentheses. For example, the monitoring permission timer for indoor unit 3b is expressed as Tm2 (B). Hereinafter, the same notation is used for other timers.

TmO 1 (B) represents the first prohibition timer of the indoor unit 3b. The first prohibition timer is a timer that counts a time during which each indoor unit is initially prohibited from monitoring the room temperature after the outdoor control unit 25 starts the room temperature monitoring control. Note that the first-time prohibition timer TmO 1 (A) of the indoor unit 3a is set to zero as described later, and is not shown in FIG.

The outdoor control unit 25 sets the timer value of each timer as follows.

First, the time during which the indoor units 3a, 3b, 3c, and 3d are prohibited from monitoring the room temperature is the room temperature monitoring inhibition time T1, and the indoor units 3a, 3b, 3c, and 3d are the room temperature monitoring times, respectively. The time permitted for monitoring is referred to as the room temperature monitoring permitted time T2. The room temperature monitoring prohibited time T1 and the room temperature monitoring permitted time T2 are the same for each indoor unit 3a, 3b, 3c, 3d. Accordingly, the timer values of the monitoring permission timers Tm2 (A), Tm2 (B), Tm2 (C), and Tm2 (D) of the indoor units 3a, 3b, 3c, and 3d are all T2. Further, the monitoring prohibition timers Tm 1 (A), Tml (B), Tm 1 (C), and Tml (D) of the indoor units 3 a, 3 b, 3 c, and 3 d are all Tl. Here, the monitoring prohibition timer is a timer that counts the time during which each of the indoor units 3a, 3b, 3c, and 3d is prohibited from monitoring the room temperature. Count down monitoring prohibition time.

The timer value of the first prohibition timer of each indoor unit 3a, 3b, 3c, 3d is set as follows.

First, assuming that the number of indoor units performing room temperature monitoring is N, each indoor unit 3a, 3 The monitoring interval ΔΤ for b, 3c, 3d can be obtained by the following equation.

ΔΤ = (T1 + T2) ÷ Ν-Τ 2

The monitoring interval of each indoor unit means the time from the end of the permission of monitoring of the room temperature of a certain indoor unit to the start of the permission of monitoring of the room temperature of the next indoor unit.

Assuming that room temperature monitoring is performed in the order of indoor unit 3a, indoor unit 3b, indoor unit 3c, and indoor unit 3d, the timer value of the first prohibition timer of each indoor unit is given by the following equation, respectively.

TmO 1 (A) = (ΔΤ + Τ 2) X 0

TmO 1 (B) = (m T + T2) X I

TmO 1 (C) = (ΔΤ + Τ 2) X 2

TmO 1 (D) = (ΔΤ + Τ2) X 3

When starting the room temperature monitoring control, the outdoor control unit 25 sets and starts the initial prohibition timer of each of the indoor units 3a, 3b, 3c3d.

Thereafter, when the initial prohibition timer of each of the indoor units 3a, 3b, 3c, and 3d reaches the count-over, the outdoor control unit 25 permits monitoring of each of the indoor units 3a, 3b, 3c, and 3d. Set and start the timer. Thereafter, as long as the conditions for starting room temperature monitoring are satisfied, the set start of the monitoring disable timer and the monitoring enable timer for each indoor unit 3a, 3b, 3c, 3d is cyclically performed. .

Next, a specific example of the count of each timer will be described.

Room temperature monitoring prohibited time T 1 == 270 s, room temperature monitoring permitted time T 2 = 90 s, N = 4.

Under this condition, the monitoring interval ΔΤ = 0. This means that if the monitoring permission timer of a certain indoor unit counts over, the monitoring permission timer of another indoor unit is set and started immediately without any time delay. The initial prohibition timer for each indoor unit 3a, 3b, 3c, 3d is as follows. ·

TmO 1 (A) = 0 s TmO 1 (B) = 90 s

TmO 1 (C) = 180 s

TmO 1 (D) = 270 s

The monitoring enable timers Tm2 (A), Tm2 (B), Tm2 (C), Tm2 (D) = 90 s for each indoor unit 3a, 3b, 3c, 3d, the monitoring disable timer one Tml (A), FIG. ₅ shows the relationship among the timers where Tml (B), Tml (C), and Tml (C) = 270 s.

When the outdoor control unit 25 starts the room temperature monitoring control, the initial inhibition timer TmO 1 (A) = O s, TmO 1 (B) = 90 s, TmO of each of the indoor units 3 a, 3 b, 3 c, and 3 d. Set start with 1 (C) = 180 s and TmO 1 (D) = 270 s.

Since the first timer TmO 1 (A) = 0 s for the indoor unit 3a, the monitoring enable timer one Tm 2 (A) = 90 for the indoor unit 3a is set and started immediately.

Since the initial prohibition timer of indoor unit 3b is TmO l (B) = 90 s, the timer Tm2 (A) for indoor unit 3a counts over and the timer for initial prohibition of indoor unit 3b TmO at the same time. 1 (B) counts over. Then, the monitoring permission timer Tm2 (B) of the indoor unit 3b is set and started. At the same time as Tm2 (A) counts over, the monitoring prohibition timer Tml (A) = 270 (not shown) of the indoor unit 3a is set and started.

At the same time as the monitoring permission timer Tm 2 (B) of the indoor unit 3 b is over, the timer TmO 1 (C) for the first time of the indoor unit 3 c is over counting. At the same time, the monitoring permission timer Tm2 (C) of the indoor unit 3c is set and started. Hereinafter, the same applies to the indoor unit 3d.

When the monitoring permission timer Tm 2 (D) of the indoor unit 3 d is over, the monitoring prohibition timer Tml (A) (not shown) of the indoor unit 3 a is over, and the monitoring of the indoor unit 3 a is performed. The permission timer Tm2 (A) is reset and started. Thereafter, this control is repeated.

Regardless of whether the indoor units 3a, 3b, 3c, 3d are in the thermo-off state, all When the outdoor control unit transmits a monitoring permission signal to all of the indoor units 3 a, 3 b, 3 c, and 3 d, the outdoor control unit 25 has the monitoring permission timer described above. During this time, a monitoring permission signal is sent to the target indoor unit. This makes it possible to transmit the monitoring permission signal to each of the indoor units 3a, 3b, 3c, and 3d with a simple control at a time interval.

[Control when transmitting a monitoring permission signal only to indoor units in the thermo-off state]

When the monitoring permission signal is transmitted only to the indoor unit that is in the thermo-off state of the heating operation, the following control is performed in addition to the above control. When a certain indoor unit that has been in the thermo-on state is thermo-offed, the first thermo-off prohibition timer of the indoor unit is set and started. The timer value of the thermo-off initial prohibition timer is the room temperature monitoring prohibition time T1. Hereinafter, as illustrated in FIG. 6, a description will be given assuming that the indoor unit 3d is thermo-off during the count of the monitoring permission timer Tm2 (A) of the indoor unit 3a.

In this control, the monitoring permission flag f (D) is determined as follows.

(3) The thermo-off initial prohibition timer Tm 3 (D) has counted over.

(4) The monitoring enable timer Tm 2 (D) is not counting.

When both of the above conditions (3) and (4) are satisfied, the monitoring permission flag f (D) is set to f (D) = 1. Also,

(5) The thermo-off initial prohibition timer Tm 3 (D) is counting.

(6) The monitoring permission timer Tm 2 (D) is not counting.

If the above conditions (5) and (6) are both satisfied, the monitoring permission flag f (D) is set to 0.

The monitoring permission flag of each indoor unit is set to zero when monitoring control starts.

Next, when all of the following conditions (7) to (10) are satisfied, a monitoring permission signal is transmitted to the indoor unit 3d.

(7) The thermostat first off timer Tm 3 (D) of indoor unit 3 d is not counting. (8) Indoor unit 3d is in the heating thermo-off state.

(9) The monitoring permission timer Tm2 (D) of indoor unit 3d is counting.

(10) The monitoring permission flag f (D) of indoor unit 3 d is = 1.

In addition, each of the indoor units 3a, 3b, 3c, and 3d, the first thermo-off prohibition timer Tm3 (a), Tm3 (b), Tm3 (c), and Tm3 (d) start room temperature monitoring control. When you clear.

With the above control, it is possible to limit the number of indoor units that perform room temperature monitoring at the same time only for the indoor units in the thermo-off state. For this reason, the number of restricted indoor units is smaller than when room temperature monitoring permission signals are transmitted for all indoor units 3a, 3b, 3c, and 3d. That is, it is possible to lengthen the time during which the monitoring permission signal is transmitted to each indoor unit. Therefore, in the air conditioner 1, the indoor unit has a low probability of losing the monitoring opportunity.

In this air conditioner 1, the indoor control units 34a, 34b, 34c, and 34d perform room temperature monitoring when the room temperature monitoring permission signal is received and the room temperature monitoring start condition is satisfied. For this reason, even if a certain indoor control unit determines that the conditions for starting room temperature monitoring are satisfied from the conditions inside the indoor unit, the room temperature monitoring is not performed until the outdoor control unit 25 permits the room temperature monitoring. . Then, the outdoor control unit 25 does not transmit a monitoring permission signal to two or more indoor units at the same time, and monitors the indoor control units 34a, 34b, 34c, and 34d at staggered times. Send the permission signal. Therefore, two or more indoor units do not perform room temperature monitoring at the same time. For this reason, the indoor fans of two or more indoor units are not driven at the same time, and there is no sudden influence on the refrigerant. As a result, in the air conditioner 1, a sharp decrease in the outlet temperature in the operating room can be suppressed. During room temperature monitoring, the indoor fans 32a, 32b, 32c, and 32d are driven to take indoor air into the indoor units 3a, 3b, 3c, and 3d. In the air conditioner, the indoor unit in the thermo-off state However, the room temperature can be accurately detected.

Further, the timer values of the monitoring permission timer and the monitoring prohibition timer of each indoor unit 3a, 3b, 3c, 3d are the same. That is, the outdoor control unit 25 transmits a monitoring permission signal to each of the indoor control units 34a, 34b, 34c, and 34d at an equal timing. For this reason, the room temperature monitoring permission signal is transmitted to the indoor units 3a, 3b, 3c, and 3d in the same cycle with a delay. For this reason, each indoor unit 3a, 3b, 3c, 3d is given an even opportunity to perform room temperature monitoring. Thereby, it is possible to suppress the occurrence of bias in the number of room temperature monitoring of the indoor units 3a, 3b, 3c, 3d.

The number of indoor units connected to the outdoor unit 2 is not limited to the number described in the above embodiment, but may be two or three, or five or more.

In the above embodiment, the monitoring permission timer is not counted for two or more indoor units at the same time.However, if the effect on the refrigerant is small, monitoring permission for two or more indoor units at the same time is permitted. In the above embodiment, the monitoring permission signal is transmitted from the outdoor control unit 25, and the monitoring start conditions of the indoor units 3a, 3b, 3c, and 3d are satisfied, and the monitoring permission signal is transmitted. Room temperature monitoring is performed when both receiving a signal are satisfied. However, the signal transmitted by the outdoor control unit 25 is not limited to the monitoring permission signal, and a monitoring prohibition signal may be transmitted. In this case, room temperature monitoring is performed when both the monitoring start conditions of the indoor units 3a, 3b, 3c, and 3d are satisfied and the monitoring prohibition signal is not received.

(Industrial applicability)

By using the air conditioner according to the present invention, it is possible to accurately detect the indoor temperature even in an indoor unit in a thermo-off state while suppressing a sharp drop in the outlet temperature in the operating room.

Claims

The scope of the claims

Room temperature sensor (33a, 33b, 33c, 33d), indoor heat exchanger (30a, 30b, 30c, 30d) and indoor fan (32a, 32d , 32c, 32d) and the room temperature sensor (33a, 33b, 33c, 33d) to determine whether the conditions for starting room temperature monitoring are satisfied, and to perform heating operation. When monitoring the room temperature when the thermostat is turned off, the indoor control units (34a, 34b, 34c, 34d) that drive the indoor fans (32a, 32d, 32c, 32d) A plurality of indoor units (3a, 3b, 3c, 3d) each having

An outdoor unit (2) having an outdoor heat exchanger (22) and forming a refrigerant circuit with the plurality of indoor units (3a, 3b, 3c, 3d);

Room temperature monitoring for selecting a predetermined indoor unit from the plurality of indoor units (3a, 3b, 3c, 3d) and transmitting a signal regarding permission for room temperature monitoring to the indoor control unit of the selected indoor unit. Control unit (25),

With

The indoor control unit (34a, 34b, 34c, 34d) determines whether to perform room temperature monitoring based on both the signal and the start condition of the room temperature monitoring.

Air conditioner.

2.

The signal is a room temperature monitoring permission signal that permits performing room temperature monitoring,

The room controller (34a, 34b, 34c, 34d) receives the room temperature monitoring permission signal, and performs room temperature monitoring when the room temperature monitoring start condition is satisfied.

The air conditioner according to claim 1.

3.

The room temperature monitoring control unit (25) transmits the room temperature monitoring permission signal The transmission is performed with a time lag for each of the indoor control units (34a, 34b, 34c, 34d).

3. The air conditioner according to claim 2.

Four.

The room temperature monitoring control unit (25) transmits the signal to each of the indoor control units (34a, 34b, 34c, 34d) at an even timing. The air conditioner described in Crab.

Five.

The room temperature monitoring control unit transmits the signal only to the indoor control unit of the indoor unit in the thermo-off state of the heating operation among the plurality of indoor units (34a, 34b, 34c, 34d). ,

The air conditioner according to any one of claims 1 to 4.

6.

The room temperature monitoring control unit transmits the signal to all the indoor units (34a, 34b, -34c, 34d),

The air conditioner according to any one of claims 1 to 4.