AIR-CONDITIONING SYSTEM

Abstract

 Disclosed herein is an air-conditioning system including air conditioners (10). Each of the air conditioners (10) that has been deactivated under a rotation operation remains inactive even if a human detection sensor (51) senses the presence of a human in a room. This may prevent excessive operation of the air conditioners, reduce power consumption, and extend the life of the entire system.

Description

TECHNICAL FIELD

[0001] The present invention relates to an air conditioning system, and more particularly relates to an air conditioning system performing a rotation operation in which at least one, but not all, of a plurality of air conditioners is deactivated sequentially.

BACKGROUND ART

[0002] A rotation operation technique has been known in the art. According to the rotation operation technique, a plurality of air conditioners are provided to air-condition the same target space, and at least one, but not all, of the plurality of air conditioners is deactivated sequentially. An air-conditioning system of Patent Document 1 includes six air conditioners provided to air-condition the same target space and controlled by a single centralized controller. This air conditioning system performs a rotation operation in which, for example, one of the six air conditioners is deactivated sequentially, while the other five air conditioners are activated. The rotation operation is performed on the premise that the target space is air-conditioned sufficiently by the activated air conditioner only.

[0003] A technique for switching the operational state of an air conditioner depending on whether or not there is any human in the target space has also been known in the art. An air conditioning system of Patent Document 2 includes a human detection sensor and allows the air conditioner to operate normally while the human detection sensor is sensing the presence of a human. If the human detection sensor does not sense the presence of a human and if the other predetermined conditions are met, the power consumed by the air conditioner is reduced. For example, the power consumption may be reduced by deactivating the air conditioner.

CITATION LIST

PATENT DOCUMENTS

[0004] 

[Patent Document 1] Japanese Unexamined Patent Publication No. 2006-275458

[Patent Document 2] Japanese Unexamined Patent Publication No. 2013-108693

SUMMARY OF THE INVENTION

TECHNICAL PROBLEM

[0005] Thus, an air-conditioning system provided with a plurality of air conditioners for air-conditioning the same target space may be configured to perform the rotation operation and the control based on the human detection in combination.

[0006] However, if the rotation operation and the control based on the human detection are combined, the target space may be air-conditioned excessively. That is, during the rotation operation, the target space is air-conditioned sufficiently as described above by the activated air conditioner. If one of the other air conditioners that has been deactivated under the rotation operation is activated because the human detection sensor has sensed the presence of a human, the air conditioner which needs not to be activated to air-condition the target space sufficiently is activated unnecessarily (hereinafter referred to as an "excessive operation"). If the excessive operation is performed, the power is wasted and the life of the entire air-conditioning system is shortened.

[0007] In view of the foregoing, it is therefore an object of the present invention to reduce the power consumed by, and eventually extend the life of, an air conditioning system which is configured to perform a rotation operation and control based on human detection by substantially preventing the system from performing such an excessive operation.

SOLUTION TO THE PROBLEM

[0008] A first aspect of the present disclosure is directed to an air-conditioning system including: a plurality of air conditioners (10) each having an indoor unit (12) and an outdoor unit (11); and a human detection sensor (51) provided for the indoor unit (12) of each of the air conditioners (10) to sense the presence/absence of a human in a room, wherein the air-conditioning system (1) is configured to be able to perform a rotation operation in which at least one, but not all, of the plurality of air conditioners (10) is deactivated sequentially, and an absence operation in which each of the air conditioners (10) is deactivated as long as the human detection sensor (51) associated with the air conditioner (10) senses the absence of a human in the room.

[0009] The air-conditioning system (1) according to the first aspect of the present disclosure is configured such that each of the air conditioners (10) that has been deactivated under the rotation operation remains inactive even if the human detection sensor (51) senses the presence of a human in the room.

[0010] According to the first aspect of the present disclosure, the air conditioning system (1) is configured to be able to perform a rotation operation and an absence operation. During the rotation operation, at least one, but not all, of the plurality of air conditioners (10) is deactivated sequentially. During the absence operation, as long as the human detection sensor (51) senses the absence of a human, the air conditioner (10) associated with this human detection sensor (51) is deactivated.

[0011] Note that as long as the human detection sensor (51) senses the presence of a human in the room, the absence operation is not performed on the air conditioner (10) provided with this human detection sensor (51). That is, as long as the human detection sensor (51) senses the presence of a human in the room, the air conditioner (10) provided with this human detection sensor (51) is ready to be activated. Suppose that the human detection sensor (51) associated with the air conditioner (10) deactivated under the rotation operation has sensed the presence of a human in the room. In that case, if this air conditioner (10) were activated independently of the rotation operation, the excessive operation would be performed.

[0012] In the air-conditioning system (1) according to the first aspect, however, each of the air conditioners (10) that has been deactivated under the rotation operation remains inactive even if the human detection sensor (51) senses the presence of a human in the room. That is, the air conditioner (10) that has been deactivated under the rotation operation is not activated independently of the rotation operation. Thus, the air conditioning system (1) of the present invention does not perform the excessive operation.

[0013] A second aspect of the present disclosure is an embodiment of the first aspect of the present disclosure. The air conditioning system (1) according to the second aspect is configured to selectively turn ON and OFF the absence operation.

[0014] According to the second aspect, the absence operation is selectively turned ON and OFF depending on the situation. Thus, the absence operation may be performed if the air conditioner (10) needs to be selectively activated and deactivated depending on the presence/absence of a human. On the other hand, the absence operation may be stopped if the air conditioner (10) that has been activated under the rotation operation needs to be kept active irrespective of the presence/absence of a human.

[0015] A third aspect of the present disclosure is an embodiment of the first or second aspect of the present disclosure. According to the third aspect, each of the air conditioners (10) is configured such that the duration of its deactivation period under the rotation operation does not change depending on whether the air conditioner (10) is deactivated under the absence operation or not.

[0016] According to the third aspect, the duration of the deactivation period of each of the air conditioners (10) under the rotation operation does not change depending on whether the air conditioner is deactivated under the absence operation or not. Thus, there is no need to change the deactivation period depending on whether the absence operation is performed or not. This facilitates the control for performing the rotation operation.

ADVANTAGES OF THE INVENTION

[0017] According to the first aspect of the present disclosure, each of the air conditioners (10) that has been deactivated under the rotation operation remains inactive even if the human detection sensor (51) senses the presence of a human in a room. Thus, the excessive operation is not performed, and thus the power consumption may be reduced, and the life of the entire air conditioning system (1) may be extended.

[0018] Further, according to the second aspect described above, a determination is made, on an application basis, whether or not the air conditioner (10) should be selectively activated and deactivated depending on the presence/absence of a human, and thus the air conditioning system (1) optimized for respective applications may be provided.

[0019] Moreover, according to the third aspect described above, each of the air conditioners (10) does not have to change the duration of its deactivation period under the rotation operation depending on whether the absence operation is performed or not. This facilitates the control for performing the rotation operation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 

[FIG. 1] FIG. 1 is a schematic view illustrating a general configuration for an air-conditioning system.

[FIG. 2] FIG. 2 is a refrigerant circuit diagram illustrating a general configuration for an air conditioner.

[FIG. 3] FIG. 3 is a flowchart illustrating a rotation operation performed by the air-conditioning system.

[FIG. 4] FIG. 4 is a timing chart illustrating the rotation operation performed by the air-conditioning system.

[FIG. 5] FIG. 5 is a flowchart illustrating human detection control performed by the air-conditioning system.

[FIG. 6] FIG. 6 is a timing chart illustrating the human detection control performed by the air-conditioning system.

[FIG. 7] FIG. 7 is a timing chart illustrating a situation where the human detection control by the air-conditioning system is turned OFF.

DESCRIPTION OF EMBODIMENTS

[0021] Embodiments of the present invention will be described in detail below with reference to the drawings. The embodiments to be described below are merely exemplary ones in nature, and do not intend to limit the scope of the present invention or applications or uses thereof.

-Air Conditioning System-

[0022] FIG. 1 shows an exemplary configuration of an air-conditioning system (1) according to an embodiment. The air-conditioning system (1) includes a plurality of air conditioners (10) conditioning the air in a room and a remote controller (20). In this example, the plurality of air conditioners (10) is comprised of first to third air conditioners (10a-10c), which are arranged in the same room. This air-conditioning system (1) performs a rotation operation in which at least one, but not all, of the first to third air conditioners (10a-10c) is deactivated sequentially, and human detection control in which the operational states of the air conditioners (10) are switched according to the presence/absence of a human in the room. The rotation operation and the human detection control will be described in detail later.

<Remote Controller>

[0023] The remote controller (20) includes a display section (21), an operating section (22), and a control section (23).

[0024] The display section (21) displays various types of information such as information about the operational state of the air-conditioning system (1), and information about the indoor environment (e.g., indoor temperature and any other characteristic values). A user operates the operating section (22) to allow the air-conditioning system (1) to perform various types of operations. The operating section (22) may be comprised of, for example, an operation button to be pressed by a user.

[0025] The control section (23) may be comprised of a CPU, a memory, and any other suitable elements, and is electrically connected to, and communicates with, the first to third air conditioners (10a-10c) through electric wires. The control section (23) controls the first to third air conditioners (10a-10c) in response to a manipulation done on the operating section (22). The control section (23) has a rotation control portion performing the rotation operation.

<Air Conditioner>

[0026] FIG. 2 shows an exemplary configuration of an air conditioner (10). The air conditioner (10) includes an outdoor unit (11) and an indoor unit (12). The outdoor and indoor units (11) and (12) are connected to each other through a liquid communication pipe (13) and a gas communication pipe (14). In the air conditioner (10), the outdoor and indoor units (11) and (12), the liquid communication pipe (13), and the gas communication pipe (14) form a refrigerant circuit (30).

«Refrigerant Circuit»

[0027] The refrigerant circuit (30) is a closed circuit filled with a refrigerant, and includes a compressor (31), a four-way switching valve (32), an outdoor heat exchanger (33), an expansion valve (34) and an indoor heat exchanger (35). The outdoor unit (11) includes the compressor (31), the four-way switching valve (32), the outdoor heat exchanger (33), and the expansion valve (34), while the indoor unit (12) includes an indoor heat exchanger (35). Further, the outdoor unit (11) includes an outdoor fan (36) and an outdoor controller (41), while the indoor unit (12) includes an indoor fan (37), an indoor controller (42), an indoor temperature sensor (50), and a human detection sensor (51).

[0028] In the refrigerant circuit (30), the compressor (31) has its discharge end connected to a first port of the four-way switching valve (32), and its suction end connected to a second port of the four-way switching valve (32), respectively. Further, in the refrigerant circuit (30), the outdoor heat exchanger (33), the expansion valve (34), and the indoor heat exchanger (35) are arranged in this order between a third port and a fourth port of the four-way switching valve (32). The outdoor fan (36) is arranged near the outdoor heat exchanger (33), and the indoor fan (37) is arranged near the indoor heat exchanger (35).

[0029] The compressor (31) is configured to compress and discharge the refrigerant, and may have its capacity varied. For example, the compressor (31) is a hermetic scroll or rotary compressor.

[0030] The four-way switching valve (32) is switchable between a first state (indicated by the solid curves in FIG. 2) where the first port communicates with the third port and the second port communicates with the fourth port, and a second state (indicated by the broken curves in FIG. 2) where the first port communicates with the fourth port and the second port communicates with the third port.

[0031] The outdoor fan (36) supplies outdoor air to the outdoor heat exchanger (33). The outdoor heat exchanger (33) allows the outdoor air transported by the outdoor fan (36) to exchange heat with the refrigerant. For example, the outdoor heat exchanger (33) is configured as a cross-fin type fin-and-tube heat exchanger.

[0032] The expansion valve (34) is configured to adjust the pressure of the refrigerant, and have its degree of opening adjustable. For example, the expansion valve (34) is configured as an electronic expansion valve.

[0033] The indoor fan (37) supplies indoor air to the indoor heat exchanger (35). The indoor heat exchanger (35) allows the indoor air transported by the indoor fan (37) to exchange heat with the refrigerant. For example, the indoor heat exchanger (35) is configured as a cross-fin type fin-and-tube heat exchanger.

«Indoor Temperature Sensor»

[0034] The indoor temperature sensor (50) is arranged in the indoor unit (12) upstream of the indoor heat exchanger (35) (upstream in the flow direction of the air), and thus the temperature detected by the indoor temperature sensor (50) is substantially equal to the indoor air temperature. The indoor air temperature detected by the indoor temperature sensor (50) is transmitted to the indoor controller (42).

«Human Detection Sensor»

[0035] The human detection sensor (51) is provided for the indoor unit (12). In the present embodiment, the human detection sensor (51) is comprised of first to third human detection sensors (51a-51c), each of which senses the presence/absence of a human in the room. More specifically, each of the human detection sensors (51) senses the presence/absence of a human around the indoor unit (12) in which the human detection sensor (51) is provided. For example, the first human detection sensor (51a) provided in the indoor unit (12) of the first air conditioner (10a) senses the presence/absence of a human around the indoor unit (12) of the first air conditioner (10a). Information about the presence/absence of a human sensed by the human detection sensor (51) is transmitted to the indoor controller (42).

«Indoor and Outdoor Controllers»

[0036] Each of the outdoor and indoor controllers (41) and (42) is comprised of a CPU, a memory and any other suitable elements, and these controllers are electrically connected to each other through wires to communicate with each other. Further, the outdoor and indoor controllers (41) and (42) are also connected electrically to, and communicate with, the control section (23) of the remote controller (20) through wires. The outdoor controller (41) controls the operation of the compressor (31), the four-way switching valve (32), the expansion valve (34), and the outdoor fan (36) that are provided in the outdoor unit (11). The indoor controller (42) controls the operation of the indoor fan (37) provided in the indoor unit (12). In this way, the operation of the refrigerant circuit (30), the outdoor fan (36), and the indoor fan (37) is controlled to control the operation of the air conditioner (10).

[0037] The memory (not shown) of the indoor controller (42) stores a target temperature which is set in advance with respect to the indoor air temperature. The indoor controller (42) includes a human detection controller which performs human detection control to be described later.

<Operation Mechanism of Air Conditioner>

[0038] A fundamental operation mechanism of each of the air conditioners (10) will be described below. The air conditioner (10) conditions the indoor air such that the indoor air temperature detected by the indoor temperature sensor (50) becomes as close to the preset target temperature as possible. Specifically, the air conditioner (10) performs cooling and heating operations.

«Cooling Operation»

[0039] During the cooling operation, the outdoor and indoor controllers (41) and (42) set the four-way switching valve (32) to be the first state (indicated by the solid curves in FIG. 2), and drives the compressor (31), the outdoor fan (36), and the indoor fan (37). Thus, in the refrigerant circuit (30), the outdoor heat exchanger (33) functions as a condenser and the indoor heat exchanger (35) functions as an evaporator. Specifically, a high-pressure refrigerant compressed by the compressor (31) flows into the outdoor heat exchanger (33) and dissipates heat to the outdoor air in the outdoor heat exchanger (33) to condense. The refrigerant condensed in the outdoor heat exchanger (33) has its pressure reduced by the expansion valve (34), flows into the indoor heat exchanger (35), and then absorbs heat from the indoor air in the indoor heat exchanger (35) to evaporate. Thus, the indoor air is cooled. The refrigerant evaporated in the indoor heat exchanger (35) is sucked into, and compressed again by, the compressor (31).

«Heating Operation»

[0040] During the heating operation, the outdoor and indoor controllers (41) and (42) set the four-the way switching valve (32) to be the second state (indicated by broken curves in FIG. 2), and drives the compressor (31), the outdoor fan (36), and the indoor fan (37). Thus, in the refrigerant circuit (30), the indoor heat exchanger (35) functions as a condenser and the outdoor heat exchanger (33) functions as an evaporator. Specifically, a high-pressure refrigerant compressed by the compressor (31) flows into the indoor heat exchanger (35) and dissipates heat to the indoor air in the indoor heat exchanger (35) to condense. Thus, the indoor air is heated. The refrigerant condensed in the indoor heat exchanger (35) has its pressure reduced by the expansion valve (34), flows into the outdoor heat exchanger (33), and then absorbs heat from the outdoor air in the outdoor heat exchanger (33) to evaporate. The refrigerant evaporated in the outdoor heat exchanger (33) is sucked into, and compressed again by, the compressor (31).

<Inactive/Active Air Conditioners>

[0041] In this air-conditioning system (1), each of the air conditioners (10) is either inactive or active. Specifically, the memory (not shown) of the indoor controller (42) of the air conditioner (10) stores a deactivation bit value indicating whether the air conditioner (10) is inactive or not. The deactivation bit value is "1" if the air conditioner (10) is inactive, or is "0" if the air conditioner (10) is not inactive (i.e., if the air conditioner (10) is active).

[0042] In the currently inactive air conditioner (10), the outdoor and indoor controllers (41) and (42) turn OFF the compressor (31), the outdoor fan (36), and the indoor fan (37). On the other hand, in the currently active air conditioner (10), basically, the outdoor and indoor controllers (41) and (42) turn ON the compressor (31), the outdoor fan (36), and the indoor fan (37). However, even in the currently active air conditioner (10), the compressor (31) and the fans (36, 37) may be turned OFF when the indoor air temperature reaches a target temperature range (a so-called "thermo-off" operation may be performed).

[0043] Further, in this example, the control section (23) of the remote controller (20) sets the air conditioner (10) to be either inactive or active.

[0044] Specifically, the control section (23) transmits a deactivate command (e.g., an instruction code including the deactivation bit value of "1") to the air conditioner (10) to be selected as an inactive one among the plurality of air conditioners (10). In the air conditioner (10) to which the deactivate command is transmitted, the CPU (not shown) of the indoor controller (42) sets the deactivation bit value stored in the memory (not shown) of the indoor controller (42) to be "1" upon receiving the deactivate command from the control section (23). In this way, the air conditioner (10) is selected as an inactive one.

[0045] Further, the control section (23) transmits a cancel deactivation command (e.g., an instruction code including the deactivation bit value of "0") to the air conditioner (10) to be selected as an active one among the plurality of air conditioners (10). In the air conditioner (10) to which the cancel deactivation command is transmitted, the CPU of the indoor controller (42) sets the deactivation bit value stored in the memory of the indoor controller (42) to be "0" upon receiving the cancel deactivation command from the control section (23). In this way, the air conditioner (10) is selected as an active one.

<Rotation Operation>

[0046] The rotation operation will be described with reference to FIG. 3. If a rotation start manipulation (a manipulation to instruct the start of the rotation operation) is done on the operating section (22) of the remote controller (20), the air-conditioning system (1) performs the following processing (an initial operation, a partial deactivation operation, and a transitional operation).

[0047] In this example, the memory (not shown) of the control section (23) of the remote controller (20) stores information about the order of operation of the air conditioners (10) during the rotation operation (such as the number of the air conditioners to be deactivated and the order of selection of the air conditioners to be deactivated). The memory of the control section (23) also stores information about the duration of operation during the rotation operation (such as an initial operation duration (T0), a partial deactivation duration (T1) and a transitional operation duration (T2)). For example, the initial operation duration (T0) and the transitional operation duration (T2) may be set to be 0.5 hours, and the partial deactivation duration (T1) may be set as appropriate in the range of 2.5 to 95.5 hours.

<<Step (ST11)>>

[0048] First, an initial operation is performed. During the initial operation, a predetermined number of air conditioners (10), selected from among the plurality of air conditioners (10), condition the indoor air. Note that the number of the air conditioners (10) activated during the initial operation is larger than the number of the air conditioners (10) activated during the partial deactivation operation. Specifically, the control section (23) selects the air conditioner (10) to be activated from among the plurality of air conditioners (10) based on the predetermined order of operation. Each of the air conditioners (10) selected as the ones to be activated performs the cooling and heating operations (which will be hereinafter collectively referred to as "air-conditioning operations").

<<Step (ST12)>>

[0049] Then, the control section (23) determines whether or not the predetermined initial operation duration (T0) has passed since the start of the initial operation. Specifically, the control section (23) starts to measure the amount of time passed when the air conditioner (10) to be activated is selected in Step (ST11), and then determines whether or not the amount of time passed has reached the initial operation duration (T0). If the initial operation duration (T0) has passed, the process proceeds to Step (ST13).

<<Step (ST13)>>

[0050] Then, the partial deactivation operation is performed. During the partial deactivation operation, at least one (but not all) predetermined air conditioner (10), selected from among the plurality of air conditioners (10), is deactivated, while the other air conditioners (10) condition the indoor air. Specifically, the control section (23) selects the air conditioner (10) to be deactivated from the active ones (10) of the plurality of air conditioners (10) based on the predetermined order of operation. The air conditioner (10) selected as the one to be deactivated stops the air conditioning operation.

<<Step (ST14)>>

[0051] Then, the control section (23) determines whether or not the predetermined partial deactivation duration (T1) has passed since the start of the partial deactivation operation. Specifically, the control section (23) starts to measure the amount of time passed when the air conditioner (10) to be deactivated is selected in Step (ST13), and then determines whether or not the amount of time passed has reached the partial deactivation duration (T1). If the partial deactivation duration (T1) has passed, the process proceeds to Step (ST15).

<<Step (ST15)>>

[0052] Then, the transitional operation is performed. During the transitional operation, the air conditioner (10) which will be deactivated next among the plurality of air conditioners (10) continues the air-conditioning operation, while at least one, or all, of the currently inactive air conditioners (10) resume the air-conditioning operation. Specifically, the control section (23) selects an air conditioner (10) to be activated from the inactive ones (10) of the plurality of air conditioners (10) based on the predetermined order of operation. The air conditioner (10) selected as the one to be activated resumes the air-conditioning operation.

<<Step (ST16)>>

[0053] Then, the control section (23) determines whether or not the predetermined transitional operation duration (T2) has passed since the start of the transitional operation. Specifically, the control section (23) starts to measure the amount of time passed when the air conditioner (10) to be activated is selected in Step (ST15), and then determines whether or not the amount of time passed has reached the transitional operation duration (T2). If the transitional operation duration (T2) has passed, the process proceeds to Step (ST13).

[0054] By repeatedly performing this series of processing steps, at least one, but not all, of the plurality of air conditioners (10) is deactivated sequentially. Further, if a rotation end manipulation (a manipulation instructing the system to end the rotation operation) is done on the operating section (22) of the remote controller (20), the control section (23) of the remote controller (20) selects all of the plurality of air conditioners (10) as those to be activated, and ends the processing for the rotation operation. In this manner, the rotation operation ends.

<Specific Examples of Rotation Operation>

[0055] Referring to FIG. 4, the rotation operation will be described more specifically below. In this example, one of the first to third air conditioners (10a-10c) is selected as the one to be deactivated during the partial deactivation operation so that the first to third air conditioners (10a-10c) are sequentially deactivated one by one by beginning with the first air conditioner (10a). Further, during the initial operation, all of the first to third air conditioners (10a-10c) are selected as those to be activated.

[0056] At Time (t0), a rotation start manipulation is done on the operating section (22) of the remote controller (20) to activate all of the first to third air conditioners (10a-10c). For example, the control section (23) of the remote controller (20) transmits the cancel deactivation command to all of the first to third air conditioners (10a-10c). In accordance with this command, the three air conditioners (10a-10c) condition the indoor air during the initial operation.

[0057] Then, when the initial operation duration (T0) passes, the first air conditioner (10a) is selected at Time (t1) as the one to be deactivated from the first to third air conditioners (10a-10c) that are currently activated. For example, the control section (23) transmits the deactivate command to the first air conditioner (10a). In accordance with this command, during the first partial deactivation operation, the two air conditioners (10b, 10c) other than the first air conditioner (10a) condition the indoor air.

[0058] Then, at Time (t2) when the partial deactivation duration (T1) passes, the first air conditioner (10a) that has been inactive is selected as the one to be activated. For example, the control section (23) transmits the cancel deactivation command to the first air conditioner (10a). In accordance with this command, during the first transitional operation, the second air conditioner (10b) which will be deactivated next continues the air-conditioning operation, and the first air conditioner (10a) that has been inactive resumes the air-conditioning operation. The third air conditioner (10c) also continues the air-conditioning operation. Thus, the three air conditioners (10a-10c) condition the indoor air.

[0059] Then, at Time (t3) when the transitional operation duration (T2) passes, the second air conditioner (10b) is selected as the one to be deactivated from the first to third air conditioners (10a-10c) that are currently active. Thus, during the second partial deactivation operation, the two air conditioners (10a, 10c) other than the second air conditioner (10b) condition the indoor air.

[0060] Then, at Time (t4) when the partial deactivation duration (T1) passes, the second air conditioner (10b) that has been inactive is selected as the one to be activated. Thus, during the second transitional operation, the third air conditioner (10c) which will be deactivated next continues the air-conditioning operation, and the second air conditioner (10b) that has been inactive resumes the air-conditioning operation. The first air conditioner (10a) also continues the air-conditioning operation. Thus, the three air conditioners (10a-10c) condition the indoor air.

[0061] Then, at Time (t5) when the transitional operation duration (T2) passes, the third air conditioner (10c) is selected as the one to be deactivated from the first to third air conditioners (10a-10c) that are currently active. Thus, during the third partial deactivation operation, the two air conditioners (10a, 10b) other than the third air conditioner (10c) condition the indoor air.

[0062] Then, at Time (t6) when the partial deactivation duration (T1) passes, the third air conditioner (10c) that has been inactive is selected as the one to be activated. Thus, during the third transitional operation, the first air conditioner (10a) which will be deactivated next continues the air-conditioning operation, and the third air conditioner (10c) that has been inactive resumes the air-conditioning operation. The second air conditioner (10b) also continues the air-conditioning operation. Thus, the three air conditioners (10a-10c) condition the indoor air.

[0063] Then, at Time (t7) when the transitional operation duration (T2) passes, the first air conditioner (10a) is selected again as the one to be deactivated from the first to third air conditioners (10a-10c) that are currently active. Thus, during the fourth partial deactivation operation, the two air conditioners (10b, 10c) other than the first air conditioner (10a) condition the indoor air.

[0064] As can be seen from the foregoing, at least one, but not all, of the plurality of air conditioners (10) is deactivated sequentially, and therefore, the operating durations of the plurality of air conditioners (10) may be leveled with each other. Further, a decrease in the air-conditioning capacity of the air-conditioning system (1) in the beginning of the rotation operation may be minimized by performing the initial operation in the beginning of the rotation operation. In addition, by performing the transitional operation between the partial deactivation operations during the rotation operation, the active air conditioner (10) which will be deactivated next may be turned from the active one into the inactive one after the inactive air conditioner (10) has been switched into be active one. This may minimize a decrease in the air-conditioning capacity of the air-conditioning system (1) due to the switch of the air conditioner (10) from the inactive state to the active state.

<Human Detection Control>

[0065] Referring to FIG. 5, human detection control will be described. If a human detection start manipulation (a manipulation instructing the system to start the human detection control) is done on the operating section (22) of the remote controller (20), the air-conditioning system (1) performs the following processing. The following processing is performed in the respective indoor units (12). That is, the indoor controller (42) provided in the indoor unit (12) of the first air conditioner (10a) performs the processing steps (ST21)-(ST23) based on the output of the first human detection sensor (51 a). The same is applied to the second and third air conditioners (10b) and (10c).

<<Step (ST21)>>

[0066] First, the indoor controller (42) determines whether the human detection sensor (51) of the indoor unit (12) has sensed the presence or absence of a human in the room. Then, if the human detection sensor (51) has sensed the presence of a human, the process proceeds to Step (ST22). On the other hand, if the human detection sensor (51) has sensed the absence of a human, the process proceeds to Step (ST23).

<<Step (ST22)>>

[0067] If the human detection sensor (51) has sensed the presence of a human in the room, the indoor controller (42) makes the air conditioner (10) associated with this human detection sensor (51) perform the air-conditioning operation. Thus, the air conditioner (10) around which there is a human performs the air-conditioning operation. Note that the air conditioner (10) selected as an inactive machine under the rotation operation is not selected as the machine to be activated even if the human detection sensor (51) associated with that air conditioner (10) senses the presence of a human in the room. Then, the process goes back to Step (ST21) again.

<<Step (ST23)>>

[0068] On the other hand, if the human detection sensor (51) has sensed the absence of a human, the indoor controller (42) performs an absence operation. Specifically, the indoor controller (42) selects the air conditioner (10) associated with the human detection sensor (51) which has sensed the absence of a human as an inactive air conditioner. Thus, the air conditioner (10) around which no human is present remains inactive. Then, the process goes back to Step (ST21) again.

[0069] By repeatedly performing this series of processing steps, the operational states of the air conditioners (10) are switched depending on the presence/absence of a human in the room. Then, when a human detection end manipulation (a manipulation instructing the system to end the human detection control) is done on the operating section (22) of the remote controller (20), the human detection control ends.

<Specific Examples of Human Detection Control>

[0070] Then, referring to FIGS. 6 and 7, the human detection control will be described in detail. In this example, the air-conditioning system (1) performs the human detection control during the rotation operation. The human detection control including the absence operation may be selectively turned ON and OFF. Now, a situation where the human detection control is executed (see FIG. 6) will be described first, and then a situation where the human detection control is aborted (see FIG. 7) will be described next.

«When Human Detection Control is Executed»

[0071] As shown in FIG. 6, at Time (t0), a rotation start manipulation and a human detection start manipulation are done on the operating section (22) of the remote controller (20). In response to these manipulations, the above-described rotation operation is started, and the human detection control is performed. That is, the air-conditioning system is ready to perform the absence operation if the human detection sensor (51) senses the absence of a human.

[0072] During the period from Time (t0) to Time (t8), all of the first to third human detection sensors (51a-51c) sense the presence of a human in the room. Thus, not all of the first to third air conditioners (10a-10c) are deactivated under the absence operation. Therefore, during that period from Time (t0) to Time (t8), the operational states of the first to third air conditioners (10a-10c) are switched under the rotation operation.

[0073] Then, at Time (t8) when a predetermined amount of time passes, for example, the third human detection sensor (51c) senses the absence of a human. At this Time (t8), the third air conditioner (10c), which has been selected as an active machine under the rotation operation, stops the air conditioning operation under the absence operation. Further, at Time (t8), the first air conditioner (10a) has been selected as an active machine, and the second air conditioner (10b) has been selected as an inactive machine under the rotation operation. Thus, among the three air conditioners (10a-10c), only the first air conditioner (10a) conditions the indoor air.

[0074] Then, at Time (t9) when a predetermined amount of time passes, the third human detection sensor (51 c) senses again the presence of a human in the room. Then, the absence operation is not performed any more, and the third air conditioner (10c) is selected as an active machine again. Thus, the third air conditioner (10c) performs the air conditioning operation. Further, at Time (t9), the first air conditioner (10a) has been selected as an active machine, and the second air conditioner (10b) has been selected as an inactive machine under the rotation operation. Thus, the two air conditioners (10a, 10c) other than the second air conditioner (10b) condition the indoor air.

[0075] During the period from Time (t1) to Time (t2), the first air conditioner (10a) has been selected as an inactive machine under the rotation operation. On the other hand, the first human detection sensor (51a) of the first air conditioner (10a) senses the presence of a human during the same period. Under these conditions, the first air conditioner (10a) does not perform the air-conditioning operation during the same period. That is, the first air conditioner (10a) that has been selected as an inactive machine under the rotation operation remains inactive even if the first human detection sensor (51 a) senses the presence of a human in the room. This is applied to all of the first to third air conditioners (10a-10c) as is apparent from the fact that the second air conditioner (10b) is inactive during the period from Time (t3) to Time (t4), and the third air conditioner (10c) is inactive during the period from Time (t5) to Time (t6). That is, each of the air conditioners (10a-10c) that has been deactivated under the rotation operation remains inactive even if the associated human detection sensor (51a-51c) senses the presence of a human in the room. Thus, the excessive operation is not performed, and thus, the power consumption may be reduced, and the life of the air-conditioning system (1) may be extended.

[0076] Further, as shown in FIG. 6, the first to third air conditioners (10a-10c) are inactive for the partial deactivation duration (T1) when they are deactivated under the rotation operation. In particular, the third air conditioner (10c) which has been inactive during the period from Time (t8) to Time (t9) under the absence operation is also inactive during the subsequent period from Time (t5) to Time (t6) (i.e., for the partial deactivation duration (T1)). Thus, the duration of the deactivation period (the partial deactivation duration (T1)) of the first to third air conditioners (10a-10c) under the rotation operation does not change depending on whether the air conditioners are deactivated under the absence operation or not. Therefore, it is not necessary to change the duration of the deactivation period under the rotation operation depending on whether the absence operation is performed or not. This facilitates the control during the rotation operation.

<When Human Detection Control is Aborted>

[0077] Referring to FIG. 7, the difference between the situation where the human detection control is aborted and the situation where the human detection control is executed will now be described.

[0078] At Time (t0), a rotation start manipulation is done on the operating section (22) of the remote controller (20), but a human detection start manipulation is not. Then, the above-described rotation operation is started, while the human detection control is not performed. That is, the absence operation is not performed even if the human detection sensor (51) senses the absence of a human.

[0079] Then, at Time (t8) when a predetermined amount of time passes, for example, the third human detection sensor (51c) senses the absence of a human. At this time, the third air conditioner (10c) has been selected as an active machine under the rotation operation. Since the absence operation is not performed even if the third human detection sensor (51c) senses the absence of a human, the third air conditioner (10c) remains active. Thus, the third air conditioner (10c) performs the air-conditioning operation without a break during the period from Time (t8) to Time (t9). Further, at Time (t8), the first air conditioner (10a) has been selected as an active machine, and the second air conditioner (10b) has been selected as an inactive machine, under the rotation operation. Thus, the two air conditioners (10a, 10c) other than the second air conditioner (10b) condition the indoor air.

[0080] Other operations are the same as in the situation where the human detection control is executed. Note that FIG. 7 illustrates the detection states of the human detection sensors (51) to show the relationship between the presence/absence of a human and the operational states of the air conditioners (10). However, the detection function of the human detection sensors (51) may be disabled when the human detection control is aborted.

[0081] In view of the foregoing, when the human detection control is aborted, the operational states of the air conditioners (10) do not change depending on the presence/absence of a human in the room. This is particularly advantageous when the air conditioning by a certain number of air conditioners (10) is required even in the absence of a human in the room (e.g., at a data center).

[0082] -Advantages of Embodiment-

[0083] According to the air conditioning system (1) of the present embodiment, the air conditioner (10) that has been deactivated under the rotation operation remains inactive even if the human detection sensor (51) senses the presence of a human in a room. Thus, the excessive operation is not performed, and thus, the power consumption may be reduced, and the life of the entire air conditioning system (1) may be extended.

[0084] Further, the human detection control including the absence operation may be selectively turned ON and OFF. This makes it possible to determine, on an application basis, whether or not the air conditioner (10) should be switched between the active and inactive states depending on the presence/absence of a human, and thus, an air-conditioning system (1) optimized for respective applications may be provided.

[0085] In addition, each of the air conditioners (10) does not have the duration of its deactivation period under the rotation operation changed depending on whether the air conditioner is deactivated under the absence operation or not. Thus, it is not necessary to change the duration of the deactivation period of each of the air conditioners (10) under the rotation operation depending on whether the absence operation is performed or not. This facilitates the control for performing the rotation operation.

«Other Embodiments»

[0086] In the above-described embodiment, the deactivate command and the cancel deactivation command are transmitted from the control section (23) of the remote controller (20) to each of the plurality of air conditioners (10). However, this configuration is not a limiting one, but the deactivate command may be circulated among the plurality of air conditioners (10). That is, the air-conditioning system may be configured such that each of the plurality of air conditioners (10) sets the other air conditioners (10) to be inactive or active. For example, the air-conditioning system may be configured such that the air conditioner (10) is set to be inactive upon receiving the deactivate command, switches itself from the inactive state to the active state when the partial deactivation duration (T1) passes since the point in time when it was set to be inactive, and then transmits the deactivate command to a predetermined one of the air conditioners (10) when the transition operation duration (T2) passes. Even with this configuration, the control section (23) of the remote controller (20) may transmit the deactivate command to any one of the plurality of air conditioners (10) to start the rotation operation. That is, the control section (23) of the remote controller (20) allows at least one, but not all, of the plurality of air conditioners (10) to be deactivated sequentially.

[0087] Further, in the above-described embodiment, the indoor controller (42) of each of the air conditioners (10) is supposed to perform the processing of the human detection control. However, the processing of the human detection control does not have to be performed by the indoor controller (42), but may also be performed by the control section (23) of the remote controller (20), for example.

[0088] Moreover, in the above-described embodiment, the air conditioner (10) is supposed to have a single outdoor unit (11) and a single indoor unit (12). However, the numbers of the outdoor and indoor units are not limiting ones, but the air conditioner (10) may have a single outdoor unit (11) and two or more indoor units (12).

INDUSTRIAL APPLICABILITY

[0089] As can be seen from the foregoing, the present invention is useful for an air-conditioning system performing a rotation operation.

DESCRIPTION OF REFERENCE CHARACTERS

[0090] 

1

Air-Conditioning System

10a-10c

First to Third Air Conditioners (Air Conditioners)

11

Outdoor Unit

12

Indoor Unit

51a-51c

First to Third Human Detection Sensors (Human Detection Sensors)

Claims

1. An air-conditioning system (1) comprising:

a plurality of air conditioners (10) each having an indoor unit (12) and an outdoor unit (11); and

a human detection sensor (51) provided for the indoor unit (12) of each of the air conditioners (10) to sense the presence/absence of a human in a room, wherein

the air conditioning system (1) is configured to be able to perform a rotation operation in which at least one, but not all, of the plurality of air conditioners (10) is deactivated sequentially, and an absence operation in which each of the air conditioners (10) is deactivated as long as the human detection sensor (51) associated with the air conditioner (10) senses the absence of a human in the room, and

each of the air conditioners (10) that has been deactivated under the rotation operation remains inactive even if the human detection sensor (51) senses the presence of a human in the room.

2. The air-conditioning system of claim 1, wherein
the system is configured to selectively turn ON or OFF the absence operation.

3. The air-conditioning system of claim 1 or 2, wherein
each of the air conditioners (10) is configured such that the duration of its deactivation period under the rotation operation does not change depending on whether or not the air conditioner (10) is deactivated under the absence operation or not.

Drawing