Air conditioning system

Abstract

An air conditioning system has an outdoor unit, a plurality of indoor units, and one or more refrigerant leakage sensors. The outdoor unit exchanges heat between outdoor air and refrigerant circulating in a refrigerant circuit. The plurality of indoor units exchange heat between indoor air and the refrigerant circulating in the refrigerant circuit to adjust the indoor air. The one or more refrigerant leakage sensors detect leakage of the refrigerant from the refrigerant circuit. The refrigerant leakage sensors are provided separately from the outdoor unit and the plurality of indoor units.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an air conditioning system having a plurality of indoor units and circulating a refrigerant to perform air conditioning. BACKGROUND

[0002] In recent years, as a refrigerant for an air conditioner, a flammable refrigerant such as R32 having a small global warming potential is proposed instead of R410A having a high global warming potential. However, the flammable refrigerant can leak from the inside of an indoor unit or a portion connected to the indoor unit. The flammable refrigerant is mostly heavier than air, so if it leaks, it is likely to stay around the floor of the room or the inside of the indoor unit, and it is difficult to diffuse.

[0003] In this regard, in Patent Literature 1, an air conditioning system in which an outdoor unit and a plurality of indoor units are communicably connected, and a refrigerant leakage sensor that detects a refrigerant leakage is provided at each indoor unit is described. The air conditioning system stops operation in the case where the refrigerant leakage sensor detects a refrigerant leakage. Thus, further leakage of the refrigerant is suppressed.

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2017-053509

[0005] However, in the case where the refrigerant leakage sensor is mounted on the indoor unit, the following problem can occur. First, the refrigerant leakage sensor in the air conditioning system needs to be changed in the case where the kind of refrigerant is changed, the characteristics of the refrigerant leakage sensor are changed, or the refrigerant leakage sensor needs to be replaced due to aging, and the like. However, if the number of indoor units in the air conditioning system increases, the burden of the change work of the refrigerant leakage sensor with respect to each indoor unit increases. SUMMARY

[0006] The present disclosure is made to solve the above problem, and aims to provide an air conditioning system that reduces the burden of change work of a refrigerant leakage sensor.

[0007] The air conditioning system of the present disclosure has: an outdoor unit that exchanges heat between outdoor air and a refrigerant in a refrigerant circuit in which the refrigerant is circulated; a plurality of indoor units that exchange heat between the refrigerant and indoor air in the refrigerant circuit to perform air conditioning of the indoor air; and one or more refrigerant leakage sensors that detect a leakage of the refrigerant from the refrigerant circuit, the refrigerant leakage sensors being provided separately from the outdoor unit and the plurality of indoor units.

[0008] According to the air conditioning system of the present disclosure, by separately arranging one or more refrigerant leakage sensors from the outdoor unit and the indoor unit, the burden of changing the refrigerant leakage sensor can be reduced without the need for changing the operation of the outdoor unit and the indoor unit. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic view showing one example of an air conditioning system of an embodiment.

[0010] Figure 2 is a schematic view for explaining the operation of an air conditioning system in a case where one or more indoor units are provided in each room.

[0011] Figure 3 is a timing chart showing one example of a processing flow based on one or more indoor units, an outdoor unit, and a stop valve unit in a case where refrigerant is detected in a room.

[0012] Figure 4 is a schematic view showing one example of a conventional air conditioning system. DETAILED DESCRIPTION

[0013] Hereinafter, an embodiment will be described based on the drawings. Note that in the following drawings, there are cases where the size relationship of each component is different from reality.

[0014] EMBODIMENT

[0015] Figure 1 is a schematic view showing one example of an air conditioning system of an embodiment. The air conditioning system 100 of the embodiment has an outdoor unit 1, a plurality of indoor units 2, and one or more stop valve units 3. The outdoor unit 1, the plurality of indoor units 2, and the stop valve unit 3 are connected via a refrigerant pipe 7 for circulating refrigerant inside. Thus, refrigerant circulates in the outdoor unit 1 and each indoor unit 2. The circuit in which refrigerant circulates like this is referred to as a refrigerant circuit 4.

[0016] Refrigerant is filled in the outdoor unit 1, but depending on the number of indoor units 2 connected to the outdoor unit 1 and the length of the refrigerant pipe 7, and the like, it can sometimes be further increased. Therefore, there are cases where refrigerant filled in an amount equal to or more than the outdoor unit 1 is enclosed in the refrigerant circuit 4.

[0017] The refrigerant in the embodiment is, for example, a refrigerant based on HFO-1234yf alone, a refrigerant mixed with HFO-1234yf, or a hydrocarbon-based refrigerant such as propane, or the like.

[0018] The outdoor unit 1 is provided with a compressor 10, a flow path switching device 11, an outdoor heat exchanger 12, an outdoor blower 13, and an outdoor flow rate adjusting valve 14. The compressor 10, the flow path switching device 11, the outdoor heat exchanger 12, and the outdoor flow rate adjusting valve 14 are connected in series by a refrigerant pipe 7.

[0019] The compressor 10 compresses the refrigerant taken in from the suction side and discharges the refrigerant as a high-temperature and high-pressure gas refrigerant from the discharge side. The flow path switching device 11 includes, for example, a four-way valve and switches the direction of the flow path of the refrigerant. The flow path of the refrigerant is switched by the flow path switching device 11, and switching between cooling and heating is performed. In Figure 1 the flow path switching device 11, the solid line portion indicates the flow path of the refrigerant at the time of cooling operation. In addition, the dashed line portion indicates the flow path of the refrigerant at the time of heating operation. Similarly, Figure 1 the arrows indicated by the solid lines indicate the direction in which the refrigerant flows at the time of cooling operation, and the arrows indicated by the dashed lines indicate the direction in which the refrigerant flows at the time of heating operation.

[0020] The outdoor heat exchanger 12 performs heat exchange between the refrigerant and the air outside. The outdoor heat exchanger 12 functions as a condenser of the refrigerant at the time of cooling operation and functions as an evaporator of the refrigerant at the time of heating operation. The outdoor blower 13 includes a propeller fan driven by a driving source such as a fan motor, which is not shown, guides the air outside to the outdoor heat exchanger 12 inside the outdoor unit 1, and sends the air, which has been heat-exchanged with the refrigerant, to the outside.

[0021] The outdoor flow rate adjusting valve 14, which is also called an expansion valve, adjusts the flow rate of the refrigerant circulating between the outdoor unit 1 and the indoor unit 2 by a change in the opening degree or decompresses the refrigerant compressed in the compressor 10. The outdoor flow rate adjusting valve 14 in the embodiment adjusts the opening degree in accordance with the operation state of the indoor unit 2. In addition, the outdoor flow rate adjusting valve 14 can be provided in the cut-off valve unit 3 described later instead of the outdoor unit 1. Alternatively, the outdoor flow rate adjusting valve 14 can be included in the outdoor unit 1 and the cut-off valve unit 3, respectively.

[0022] The indoor unit 2 is provided with an indoor heat exchanger 20, an indoor blower 21, an indoor flow rate adjusting valve 22, a notification portion 23, and an indoor control portion 24. In addition, the notification portion 23 can be included in a remote controller, which is not shown, of the indoor unit 2.

[0023] The indoor heat exchanger 20 performs heat exchange between the refrigerant from the outdoor unit 1 and the air inside. The indoor heat exchanger 20 heat-exchanges the air inside the indoor unit 2, which is sent from the inside of the room to the inside of the indoor unit 2 by the indoor blower 21, with the refrigerant.

[0024] The indoor blower fan 21 includes a propeller fan driven by a fan motor not shown, which guides the air in the room toward the indoor heat exchanger 20 in the indoor unit 2, and sends the air after heat exchange with the refrigerant toward the room. The indoor flow rate adjustment valve 22, like the outdoor flow rate adjustment valve 14, is also called an expansion valve, and adjusts the flow rate of the refrigerant circulating between the outdoor unit 1 and the indoor unit 2 by the change in the opening degree. The notification portion 23 performs notification according to the instruction of the indoor control portion 24 described later, for example, in the case of refrigerant leakage or the like.

[0025] The indoor control portion 24 controls the indoor blower fan 21, the indoor flow rate adjustment valve 22, the notification portion 23, and the like. The indoor control portion 24 causes the outdoor unit 1, the indoor unit 2, and the like to perform the air conditioning operation desired by the user according to the instruction received from a remote controller not shown. Hereinafter, the signal transmitted by the indoor control portion 24 to the outdoor unit 1 and other constituent elements of the indoor unit 2 including the indoor control portion 24 in order to perform the air conditioning operation desired by the user is referred to as a control signal.

[0026] The cut-off valve unit 3 in the embodiment is a unit provided to the refrigerant circuit 4 of each of the one or more indoor units 2 including the same room. The cut-off valve unit 3 is provided in the refrigerant circuit 4 between the outdoor unit 1 and the one or more indoor units 2.

[0027] The cut-off valve unit 3 has a plurality of cut-off valves 30 and an information processing portion 31. The cut-off valve unit 3 in the embodiment houses the plurality of cut-off valves 30 and the information processing portion 31 in the inside of a housing.

[0028] The cut-off valve 30 is provided to the refrigerant circuit 4 between the outdoor unit 1 and the indoor unit 2. The cut-off valve 30 causes the refrigerant to circulate in the refrigerant circuit 4 between the outdoor unit 1 and the indoor unit 2 by the opening operation. In addition, the cut-off valve 30 cuts off the circulation of the refrigerant in the refrigerant circuit 4 between the outdoor unit 1 and the indoor unit 2 by the closing operation. The cut-off valve unit 3 in the embodiment includes a plurality of cut-off valves 30 provided between the outdoor unit 1 and the one or more indoor units 2 of one room. However, the cut-off valve unit 3 can include a plurality of cut-off valves 30 provided between a plurality of indoor units 2 of a plurality of rooms and the outdoor unit 1.

[0029] The information processing portion 31 performs transmission and reception of data with the one or more refrigerant leakage sensors 5. In addition, the one or more refrigerant leakage sensors 5 are provided in the same room as the indoor unit 2 connected to the stop valve unit 3. In addition, the information processing portion 31 communicates with the indoor control portion 24 of each of the one or more indoor units 2 and communicates with the outdoor unit 1. The refrigerant leakage sensor 5 can also be included in the stop valve unit 3. In this case, the stop valve unit 3 is provided in the same room as the one or more indoor units 2. In addition, in the embodiment, the indoor unit 2 and the refrigerant leakage sensor 5 provided in one room and the stop valve 30 provided between the indoor unit 2 and the outdoor unit 1 are grouped into one group. Also, in the embodiment, the stop valve 30 in one group is housed in the stop valve unit 3.

[0030] The information processing portion 31 can communicate with the one or more refrigerant leakage sensors 5 through a wire, respectively, or can communicate wirelessly. In addition, in the embodiment, the information processing portion 31 communicates wirelessly with the indoor control portion 24 and the outdoor unit 1, but can communicate through a wire.

[0031] The refrigerant leakage sensor 5 is a sensor that detects the occurrence of an event in which refrigerant leaks from the refrigerant circuit 4. As the refrigerant leakage sensor 5, for example, a sensor such as an oxygen concentration type and a flammable gas detection type can be cited.

[0032] The information processing portion 31 receives a signal indicating the leakage of refrigerant from the refrigerant leakage sensor 5 in the case where the refrigerant leakage sensor 5 detects the leakage of refrigerant. The information processing portion 31 that has received the signal transmits a signal instructing a predetermined action and an action at the time of leakage of refrigerant to the plurality of stop valves 30 in the stop valve unit 3, the outdoor unit 1, and the one or more indoor units 2 connected to the stop valve unit 3. Hereinafter, the signal instructing the predetermined action at the time of leakage of refrigerant will be described as an instruction signal. The information processing portion 31 transmits the instruction signal to all of the stop valves 30 in the stop valve unit 3, all of the indoor units 2 connected to the stop valve unit 3, and the outdoor unit 1 in the case where the signal indicating the leakage of refrigerant is received from at least one refrigerant leakage sensor 5.

[0033] In addition, in a case where the plurality of shutoff valves 30 are included in one shutoff valve unit 3, which are provided between the outdoor unit 1 and the plurality of indoor units 2, the information processing portion 31 communicates with the refrigerant leakage sensor 5 of each of the plurality of indoor units. In this case, the information processing portion 31 stores the refrigerant leakage sensor 5, the indoor unit 2, and the shutoff valve 30 in groups for each indoor unit, or a plurality of indoor units adjacent to each other. Further, in a case where a signal indicating leakage of refrigerant is received from the refrigerant leakage sensor 5 provided in an arbitrary indoor unit, the information processing portion 31 transmits an instruction signal to all of the indoor units 2 and all of the shutoff valves 30 of the same group as the refrigerant leakage sensor 5, and the outdoor unit 1.

[0034] The shutoff valve 30 closes the valve to shut off the flow of refrigerant in a case where the instruction signal is received. Thereby, the inflow of refrigerant to the indoor unit 2 is suppressed. On the other hand, the shutoff valve 30 opens and closes the valve in accordance with the control signal during a period in which the instruction signal is not received. The refrigerant flows through the opening operation of the shutoff valve 30, and the flow is shut off by the closing operation.

[0035] The indoor control portion 24 in the indoor unit 2 that has received the instruction signal causes the indoor blower fan 21 in the indoor unit 2 to perform a process for diffusing the leaked refrigerant in accordance with the instruction signal. Specifically, the indoor control portion 24 controls the indoor blower fan 21 to start operation in a case where the indoor blower fan 21 is not operating before the instruction signal is received. On the other hand, the indoor control portion 24 controls the indoor blower fan 21 to increase the air volume, for example, in a case where the indoor blower fan 21 is operating before the instruction signal is received. The refrigerant is diffused by the operation of the indoor blower fan 21.

[0036] Further, the indoor control portion 24 that has received the instruction signal controls the notification portion 23 in the indoor unit 2 including the indoor control portion 24 to issue an alarm. In addition, the indoor control portion 24 that has received the instruction signal controls the indoor flow adjustment valve 22 in the indoor unit 2 to close the valve. In the embodiment, the indoor control portion 24 that has received the instruction signal does not transmit a control signal to the outdoor unit 1.

[0037] In the embodiment, the outdoor unit 1 controls the compressor 10 to stop operation and controls the outdoor flow adjustment valve 14 to close the valve in order not to cause the refrigerant to flow to the indoor unit 2 side in accordance with the instruction signal in a case where the instruction signal is received. In addition, the outdoor unit 1 in the embodiment preferentially performs an operation based on the instruction signal in a case where a control signal is received from the indoor unit 2 together with the instruction signal. That is, the outdoor unit 1 stops the operation of the compressor 10 and closes the outdoor flow adjustment valve 14 in a case where at least one instruction signal is received.

[0038] Hereinafter, the operation of the air conditioning system 100 according to the embodiment will be described with reference to the flowchart of FIG. 6. Figure 2 The specific operation example of the air conditioning system 100 according to the embodiment will be described.Figure 2 is a diagram for explaining the operation of an air conditioning system in a case where one or more indoor units are provided in each room. In Figure 2 , an example is shown in which three indoor units 2 are provided in indoor A and one indoor unit 2 is provided in indoor B. In this one example, the stop valves 30 in the refrigerant circuits 4 containing each of the one or more indoor units 2 in one room are grouped. Therefore, the stop valves 30 in the refrigerant circuits 4 containing each of the three indoor units 2 in indoor A belong to a different group from the stop valves 30 in the refrigerant circuits 4 containing the one indoor unit 2 in indoor B. Further, in the one example shown in Figure 2 , the stop valves 30 and the refrigerant leakage sensors 5 are contained in one stop valve unit 3 for each group. Therefore, the stop valves 30 in the refrigerant circuits 4 containing each of the three indoor units 2 in indoor A are housed in one stop valve unit 3, and the stop valves 30 in the refrigerant circuits 4 containing the one indoor unit 2 in indoor B are housed in another stop valve unit 3. However, a plurality of groups of stop valves 30 and refrigerant leakage sensors 5 can also be contained in one stop valve unit 3.

[0039] Hereinafter, the stop valve unit 3 containing the stop valves 30 in the refrigerant circuits 4 containing each of the three indoor units 2 in indoor A is described as stop valve unit 3A. Also, the stop valve unit 3 containing the stop valves 30 in the refrigerant circuits 4 containing the one indoor unit 2 in indoor B is described as stop valve unit 3B.

[0040] A refrigerant leakage sensor 5 is provided in indoor A. This refrigerant leakage sensor 5 can also be housed in the stop valve unit 3A. Hereinafter, this refrigerant leakage sensor 5 provided in indoor A is sometimes described as refrigerant leakage sensor 5A. The refrigerant leakage sensor 5A communicates with the information processing portion 31 contained in the stop valve unit 3A. Hereinafter, the information processing portion 31 contained in the stop valve unit 3A is sometimes described as information processing portion 31A.

[0041] A refrigerant leakage sensor 5 is provided in indoor B. This refrigerant leakage sensor 5 can also be housed in the stop valve unit 3B. Hereinafter, this refrigerant leakage sensor 5 provided in indoor B is sometimes described as refrigerant leakage sensor 5B. The refrigerant leakage sensor 5B communicates with the information processing portion 31 contained in the stop valve unit 3B. Hereinafter, the information processing portion 31 contained in the stop valve unit 3B is sometimes described as information processing portion 31B.

[0042] The information processing portion 31A communicates with each of the indoor control portions 24 of the three indoor units 2 provided in indoor A. The information processing portion 31B communicates with the indoor control portion 24 of the one indoor unit 2 provided in indoor B.

[0043] If the refrigerant leakage sensor 5A detects a leakage of refrigerant, the refrigerant leakage sensor 5A sends a signal indicating the leakage of refrigerant to the information processing portion 31A. The information processing portion 31A, which receives the signal, sends an instruction signal to the shutoff valve 30 included in the shutoff valve unit 3A so as to close the valve. The shutoff valve 30 included in the shutoff valve unit 3A closes the valve in accordance with the instruction signal. In addition, in the case where the above-mentioned outdoor flow adjustment valve 14 is provided in the shutoff valve unit 3A, the information processing portion 31A sends an instruction signal to the outdoor flow adjustment valve 14 so as to close the valve. In this case, the outdoor flow adjustment valve 14 closes the valve in accordance with the instruction signal. In addition, the information processing portion 31A sends an instruction signal to each of the indoor control portions 24 of the three indoor units 2 provided in the indoor A. The indoor control portion 24, which receives the instruction signal, controls the notification portion 23 to issue an alarm, controls the indoor blower fan 21 to perform air blowing for diffusing the leaked refrigerant, and controls the indoor flow adjustment valve 22 so as to close the valve.

[0044] On the other hand, if the refrigerant leakage sensor 5B detects a leakage of refrigerant, the refrigerant leakage sensor 5B sends a signal indicating the leakage of refrigerant to the information processing portion 31B. The information processing portion 31B, which receives the signal, sends an instruction signal to the shutoff valve 30 included in the shutoff valve unit 3B so as to close the valve. The shutoff valve 30 included in the shutoff valve unit 3B closes the valve in accordance with the instruction signal. In addition, in the case where the outdoor flow adjustment valve 14 is provided in the shutoff valve unit 3B, the information processing portion 31B sends an instruction signal to the outdoor flow adjustment valve 14 so as to close the valve. In this case, the outdoor flow adjustment valve 14 closes the valve in accordance with the instruction signal. In addition, the information processing portion 31B sends an instruction signal to each of the indoor control portions 24 of the one indoor unit 2 provided in the indoor B. The indoor control portion 24, which receives the instruction signal, controls the notification portion 23 so as to issue an alarm, controls the indoor blower fan 21 for performing air blowing for diffusing the leaked refrigerant, and controls the indoor flow adjustment valve 22 so as to close the valve.

[0045] If the information processing portion 31A and the information processing portion 31B receive the signal indicating the leakage of refrigerant, an instruction signal is sent to the outdoor unit 1. The outdoor unit 1, in accordance with the received instruction signal, controls the compressor 10 to stop the operation, and controls the outdoor flow adjustment valve 14 so as to close the valve.

[0046] In addition, when the stop valve unit 3 includes the stop valve 30 in the refrigerant circuit 4 including the indoor units 2 in the indoor A and the indoor B, the information processing portion 31 included in the stop valve unit 3 communicates with the indoor control portion 24 provided in the indoor units 2 in the indoor A and the indoor B. Also, if the information processing portion 31 receives a signal indicating a leakage of refrigerant from the refrigerant leakage sensor 5A, the information processing portion 31 transmits an instruction signal to the outdoor unit 1 and the indoor units 2 and the stop valve 30 in the same group as the refrigerant leakage sensor 5A. Similarly, if the information processing portion 31 receives a signal indicating a leakage of refrigerant from the refrigerant leakage sensor 5B, the information processing portion 31 transmits an instruction signal to the outdoor unit 1 and the indoor units 2 and the stop valve 30 in the same group as the refrigerant leakage sensor 5B.

[0047] Hereinafter, the hardware structure of the air conditioning system 100 according to the embodiment will be described. In addition, the structures of the outdoor unit 1, the indoor heat exchanger 20, the indoor blower 21, the indoor flow rate adjustment valve 22, the stop valve 30, and the refrigerant leakage sensor 5 are the same as those of the conventional ones, and thus the description thereof will be omitted. Each function of the information processing portion 31 and the indoor control portion 24 can be implemented by a structure including a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and a communication interface circuit, for example. Each communication function of the information processing portion 31 and the indoor control portion 24 can be implemented by the communication interface circuit. The functions of the information processing portion 31 other than the communication function can be implemented by the processor reading various programs stored in the memory and executing the programs. Similarly, the functions of the indoor control portion 24 other than the communication function can be implemented by the processor reading various programs stored in the memory and executing the programs. Each function of the information processing portion 31 and the indoor control portion 24 can also be implemented by a dedicated hardware, all or a part of which.

[0048] Hereinafter, the hardware structure of the air conditioning system 100 according to the embodiment will be described. In addition, the structures of the outdoor unit 1, the indoor heat exchanger 20, the indoor blower 21, the indoor flow rate adjustment valve 22, the stop valve 30, and the refrigerant leakage sensor 5 are the same as those of the conventional ones, and thus the description thereof will be omitted. Each function of the information processing portion 31 and the indoor control portion 24 can be implemented by a structure including a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and a communication interface circuit, for example. Each communication function of the information processing portion 31 and the indoor control portion 24 can be implemented by the communication interface circuit. The functions of the information processing portion 31 other than the communication function can be implemented by the processor reading various programs stored in the memory and executing the programs. Similarly, the functions of the indoor control portion 24 other than the communication function can be implemented by the processor reading various programs stored in the memory and executing the programs. Each function of the information processing portion 31 and the indoor control portion 24 can also be implemented by a dedicated hardware, all or a part of which. Figure 3 The processing flow based on the stop valve unit 3, the outdoor unit 1, and the indoor unit 2 in a case where refrigerant is detected in the indoor will be described. Figure 3 is a timing chart indicating one example of the processing flow in the air conditioning system in a case where refrigerant is detected in the indoor. In addition, the indoor unit 2 and the refrigerant leakage sensor 5 that detects a leakage of refrigerant belong to the same group.

[0049] In step S1, the information processing portion 31 receives a signal indicating a leakage of refrigerant from the refrigerant leakage sensor 5. In step S2, the information processing portion 31 sends an instruction signal to the stop valve 30 in the same group as the refrigerant leakage sensor 5. In step S3, the stop valve 30 that received the instruction signal closes the valve in accordance with the instruction signal. In step S4, the information processing portion 31 sends an instruction signal to the indoor unit 2 in the same group as the refrigerant leakage sensor 5. In step S5, the indoor control portion 24 that received the instruction signal controls the notification portion 23 to issue an alarm. In correspondence therewith, the notification portion 23 issues an alarm. In addition, the indoor control portion 24 controls the indoor air blower 21 to perform air blowing for diffusing the leaked refrigerant. In correspondence therewith, the indoor air blower 21 performs air blowing for diffusing the leaked refrigerant. In addition, the indoor control portion 24 controls the indoor flow rate adjusting valve 22 to close the valve. In correspondence therewith, the indoor flow rate adjusting valve 22 closes the valve.

[0050] In step S6, the information processing portion 31 sends an instruction signal to the outdoor unit 1. In step S7, the outdoor unit 1 that received the instruction signal controls the compressor 10 to stop the operation, and controls the outdoor flow rate adjusting valve 14 to close the valve. In addition, each of the processes in step S2, step S4, and step S6 can be performed in parallel, or can be executed in any order. Each of the processes in step S3, step S5, and step S7 can be performed in parallel after receiving the instruction signal, or can be performed in any order.

[0051] Next, differences between the air conditioning system 100 of the embodiment and a conventional air conditioning system 101 will be described. Figure 4 is a schematic view showing one example of a conventional air conditioning system. The conventional air conditioning system 101 has the outdoor unit 1 and a plurality of indoor units 6, but does not have the stop valve unit 3. In the air conditioning system 101, the stop valve 30 is provided inside or outside each of the indoor units 6 instead of the above-described stop valve unit 3. In addition, in the air conditioning system 101, the refrigerant leakage sensor 5 is provided inside or outside each of the indoor units 6. The indoor unit 6 has the above-described indoor heat exchanger 20, the above-described indoor air blower 21, the indoor flow rate adjusting valve 22, and the notification portion 23, like the above-described indoor unit 2. In addition, the indoor unit 6 has the indoor control portion 60 corresponding to the combination of the above-described information processing portion 31 and the above-described indoor control portion 24. That is, the indoor control portion 60 in the conventional indoor unit 6 also has the function based on the above-described information processing portion 31.

[0052] In the past, if the refrigerant leakage sensor 5 in the indoor unit 6 detects a leakage of refrigerant, the refrigerant leakage sensor 5 sends a signal indicating the leakage of refrigerant to the indoor control section 60 in the indoor unit 6. The indoor control section 60 in the indoor unit 6 that has detected the leakage of refrigerant controls the notification section 23 to issue an alarm and controls to close the stop valve 30 and the indoor flow rate adjustment valve 22 in the indoor unit 6. In addition, the indoor control section 60 in the indoor unit 6 sends an instruction signal in the case where a leakage of refrigerant has occurred to the outdoor unit 1.

[0053] On the other hand, in the case where the refrigerant leakage sensor 5 in the indoor unit 6 has not detected a leakage of refrigerant, the indoor control section 60 in the indoor unit 6 performs the same processing as the above-mentioned indoor control section 24. Therefore, the indoor control section 60 in the indoor unit 6 that has not detected a leakage of refrigerant sends a control signal in the case where a leakage of refrigerant has not been detected to the outdoor unit 1.

[0054] The outdoor unit 1 performs processing using the instruction signal or the control signal from each of the plurality of indoor units 6. However, if the number of indoor units 6 in the air conditioning system 101 increases, the data amount of the signals that the outdoor unit 1 should process increases. In addition, the communication amount based on the transmission and reception of signals between the outdoor unit 1 and each of the indoor units 6 increases.

[0055] In addition, the existing outdoor unit 1, even if it receives an instruction signal from an indoor unit 6 that has detected a leakage of refrigerant, in the case where it receives a control signal from another indoor unit 6 that warns of the outflow of refrigerant, there is a case where refrigerant flows out to the indoor unit 6 side. However, in the case where a plurality of indoor units 6 are provided in the same room, the following problem can occur. For example, it is possible that the refrigerant leakage sensor 5 in an indoor unit 6 where refrigerant has leaked does not detect a leakage of refrigerant, and the refrigerant leakage sensor 5 in another indoor unit 6 detects a leakage of refrigerant. In this case, the indoor unit 6 where a leakage of refrigerant has not been detected can not close the stop valve 30, and send a control signal to the outdoor unit 1 that warns of the outflow of refrigerant. Then, by the processing of the outdoor unit 1 corresponding to this control signal, it is possible that refrigerant flows into the indoor unit 6 and causes further leakage of refrigerant.

[0056] Further, in the conventional air conditioning system 101, the notification section 23 in the indoor unit 6 provided only with the refrigerant leakage sensor 5 that detects the leakage of the refrigerant issues an alarm against the leakage of the refrigerant. However, in fact, the leakage of the refrigerant sometimes occurs in other indoor units 6, and in the case where the refrigerant leakage sensor 5 in the other indoor unit 6 does not detect the leakage of the refrigerant, the user of the other indoor unit 6 cannot be sufficiently warned. Further, the indoor blower 21 of the indoor unit 6 provided with the refrigerant leakage sensor 5 that does not detect the leakage of the refrigerant does not perform the blowing process for reducing the concentration of the leaked refrigerant. Therefore, in the case where the refrigerant leakage sensor 5 of the indoor unit 6 from which the refrigerant leaks does not detect the leakage of the refrigerant, the refrigerant can remain to increase the concentration of the refrigerant.

[0057] Further, in the conventional air conditioning system 101, the notification section 23 in the indoor unit 6 provided only with the refrigerant leakage sensor 5 that detects the leakage of the refrigerant issues an alarm against the leakage of the refrigerant. However, in fact, the leakage of the refrigerant sometimes occurs in other indoor units 6, and in the case where the refrigerant leakage sensor 5 in the other indoor unit 6 does not detect the leakage of the refrigerant, the user of the other indoor unit 6 cannot be sufficiently warned. Further, the indoor blower 21 of the indoor unit 6 provided with the refrigerant leakage sensor 5 that does not detect the leakage of the refrigerant does not perform the blowing process for reducing the concentration of the leaked refrigerant. Therefore, in the case where the refrigerant leakage sensor 5 of the indoor unit 6 from which the refrigerant leaks does not detect the leakage of the refrigerant, the refrigerant can remain to increase the concentration of the refrigerant.

[0058] The air conditioning system 100 of the embodiment has the following advantages with respect to such conventional air conditioning system 101. First, in the embodiment, the shutoff valves 30 for cutting off the inflow of the refrigerant to one or more indoor units 2 in an indoor are gathered in the shutoff valve unit 3. In the case where the refrigerant leakage sensor 5 provided in the indoor detects the leakage of the refrigerant, the information processing section 31 in the shutoff valve unit 3 receives a signal indicating the leakage of the refrigerant from the refrigerant leakage sensor 5. The information processing section 31 that receives the signal transmits an instruction signal instructing the execution of a predetermined process at the time of the leakage of the refrigerant to the outdoor unit 1, the one or more indoor units 2, the shutoff valves 30, and the like. At this time, the one or more indoor units 2 that receive the instruction signal do not transmit a control signal to the outdoor unit 1. Thus, the reduction of the communication amount in the air conditioning system 100 can be achieved. Further, the outdoor unit 1 performs a process corresponding to the instruction signal in the case where at least one instruction signal is received, and thus the amount of data processing can be reduced as compared to the case where a process that also uses a control signal is performed.

[0059] If the outdoor unit 1 stops operation according to the command signal, the inflow of refrigerant to the indoor unit 2 side is suppressed. All the shutoff valves 30 that have received the command signal perform closing operation according to the command signal. In the case where the outdoor flow rate adjustment valve 14 is included in the shutoff valve unit 3, the information processing portion 31 transmits a command signal instructing closing to the outdoor flow rate adjustment valve 14, and the outdoor flow rate adjustment valve 14 closes according to the command signal. Thus, the inflow of refrigerant to all the indoor units 2 of the room is suppressed. Thereby, the case where refrigerant flows into the indoor unit 2 in which refrigerant leaks is suppressed, and further leakage of refrigerant is suppressed.

[0060] In the embodiment, all the indoor units 2 in the same room issue an alarm indicating leakage of refrigerant according to the command signal. Thus, sufficient notification can be made to the user of the same room. In addition, since each indoor blower fan 21 of all the indoor units 2 in the same room performs blower operation for diffusing refrigerant, the refrigerant is more diffused compared with the past, and further rise in the concentration of refrigerant is suppressed.

[0061] In the embodiment, the refrigerant leakage sensor 5 is not provided for each indoor unit 2 but is provided with respect to a group of indoor units 2 of the same room. Further, the refrigerant leakage sensor 5 can be provided one or plural with respect to the group of indoor units 2. One or more refrigerant leakage sensors 5 with respect to the group of indoor units 2 of the same room can also be housed in the shutoff valve unit 3. Thereby, in the case where the number of indoor units 2 in the air conditioning system 100 is large, etc., reduction in the burden of change processing of the refrigerant leakage sensor 5 can be achieved.

[0062] In the above, the air conditioning system 100 of the embodiment is provided with the outdoor unit 1, the plurality of indoor units 2, and the one or more refrigerant leakage sensors 5. The outdoor unit 1 performs heat exchange between air outside and refrigerant in the refrigerant circuit 4 in which refrigerant circulates. The plurality of indoor units 2 each perform heat exchange between refrigerant and air inside in the refrigerant circuit 4 to perform air conditioning of the inside. The one or more refrigerant leakage sensors 5 each detect leakage of refrigerant from the refrigerant circuit 4. Further, each refrigerant leakage sensor 5 is disposed separately from the outdoor unit 1 and the plurality of indoor units 2. Thereby, in the change of the refrigerant leakage sensor 5, no work is required with respect to the outdoor unit 1 and the plurality of indoor units 2. Thus, the burden of change work of the refrigerant leakage sensor 5 is reduced.

[0063] In the embodiment, the number of refrigerant leakage sensors 5 in the room is equal to or less than the number of indoor units 2 in the room. Thereby, the burden of change work of the refrigerant leakage sensor 5 is further reduced.

[0064] The air conditioning system 100 in the embodiment also has a plurality of shutoff valves 30 that shut off inflow of refrigerant to the plurality of indoor units 2 in the event of refrigerant leakage. The plurality of shutoff valves 30 are disposed separately from the outdoor unit 1 and the indoor units 2. Thus, when servicing the shutoff valves 30, servicing of each of the outdoor unit 1 and the indoor units 2 is not required, and the burden of servicing the shutoff valves 30 is reduced.

[0065] The air conditioning system 100 of the embodiment also has one or more shutoff valve units 3. The one or more shutoff valve units 3 house the plurality of shutoff valves 30 within a housing to include the plurality of shutoff valves 30. Thus, the burden of servicing the shutoff valves 30 is further reduced.

[0066] The shutoff valve unit 3 in the embodiment includes one or more refrigerant leakage sensors 5. Thus, the burden of servicing the refrigerant leakage sensors 5 is further reduced.

[0067] The shutoff valve unit 3 in the embodiment also includes an information processing portion that controls the plurality of shutoff valves 30 included in the shutoff valve unit 3. The refrigerant leakage sensor 5, in the event that refrigerant leakage is detected in an indoor unit, transmits a signal indicating the refrigerant leakage to the information processing portion 31. The information processing portion 31 controls the plurality of shutoff valves 30 that shut off inflow of refrigerant to one or more indoor units 2 provided in each indoor unit as a group. The information processing portion 31, in the event that a signal indicating refrigerant leakage in an indoor unit is received from the refrigerant leakage sensor 5, transmits an instruction signal for performing a predetermined action in the event of refrigerant leakage to the plurality of shutoff valves 30 included in the group that includes the shutoff valves 30 that shut off inflow of refrigerant to the one or more indoor units 2 in the indoor unit. The shutoff valves 30, in the event that the instruction signal is received, close the valves in accordance with the instruction signal to shut off the flow of refrigerant. Thus, in the event that refrigerant leakage is detected in an indoor unit, refrigerant leakage from the one or more indoor units 2 in the indoor unit is suppressed.

[0068] In the embodiment, the plurality of shutoff valves 30 that shut off inflow of refrigerant to the one or more indoor units 2 provided in each indoor unit are included as a group in one shutoff valve unit 3. Thus, the burden of servicing the shutoff valves 30 that shut off inflow of refrigerant to the one or more indoor units 2 in each indoor unit is reduced.

[0069] In the embodiment, the one or more refrigerant leakage sensors 5 provided in each indoor unit are grouped as a group and included in one shutoff valve unit 3. Thus, the burden of servicing the refrigerant leakage sensors 5 that detect refrigerant leakage for each indoor unit is reduced.

[0070] The shutoff valve unit 3 in the embodiment further has an information processing section 31. The information processing section 31 controls the plurality of shutoff valves 30 included in the shutoff valve unit 3. The refrigerant leakage sensor 5 transmits a signal indicating leakage of refrigerant to the information processing section 31 in a case where leakage of refrigerant is detected in the room. The information processing section 31 transmits an instruction signal for performing a predetermined action in a case where refrigerant leaks to the plurality of shutoff valves 30 included in the shutoff valve unit 3 in a case where the signal indicating leakage of refrigerant is received. The shutoff valve 30 closes the valve to shut off the flow of refrigerant in accordance with the instruction signal in a case where the instruction signal is received. Thus, the air conditioning system 100 of the embodiment can shut off the inflow of refrigerant to one or more indoor units 2 in the room where refrigerant leaks, and can reliably suppress leakage of refrigerant.

[0071] The information processing section 31 in the embodiment transmits an instruction signal for performing a predetermined action in a case where refrigerant leaks to the outdoor unit 1 in a case where the signal indicating leakage of refrigerant is received. The outdoor unit 1 stops the action in accordance with the instruction signal in a case where the instruction signal is received. In a case where leakage of refrigerant is detected, since the outdoor unit 1 stops the action in accordance with the instruction signal from the information processing section 31, the inflow of refrigerant to the indoor unit 2 side can be suppressed, and further leakage of refrigerant can be suppressed.

[0072] The indoor unit 2 in the embodiment transmits a control signal for controlling the outdoor unit 1 to the outdoor unit 1. Thus, the indoor unit 2 can reflect an air conditioning action desired by a user to the outdoor unit 1. In addition, the outdoor unit 1 in the embodiment stops the action in accordance with the instruction signal in a case where the instruction signal is received, even in a case where a control signal is received. The outdoor unit 1 suppresses the inflow of refrigerant to the indoor unit 2 side where refrigerant leaks, since the action is stopped in accordance with the instruction signal even in a case where a control signal for prompting outflow of refrigerant is received from another indoor unit 2. Thus, further leakage of refrigerant can be suppressed. In addition, the outdoor unit 1 stops the action in accordance with the instruction signal instead of processing using the instruction signal and the control signal, and thus the load of data processing based on the outdoor unit 1 can be reduced.

[0073] The information processing section 31 in the embodiment transmits an instruction signal to one or more indoor units 2 in a case where the signal indicating leakage of refrigerant is received from the refrigerant leakage sensor 5 that detects leakage of refrigerant in the room. The indoor unit 2 does not transmit a control signal for controlling the outdoor unit 1 to the outdoor unit 1 in accordance with the instruction signal in a case where the instruction signal is received. Thus, reduction of the amount of communication in the air conditioning system 100 can be achieved. In addition, the outdoor unit 1 does not need to perform reception processing of the control signal and processing using the control signal, and thus the amount of processing based on the outdoor unit 1 can be reduced.

[0074] The information processing portion 31 in the embodiment transmits an instruction signal for executing a predetermined action in the case of a refrigerant leakage to one or more indoor units 2 of the indoor in which a leakage of a refrigerant is detected from the refrigerant leakage sensor 5 that detects a leakage of a refrigerant in the indoor. The indoor unit 2 is provided with an indoor blower 21 that blows air into the indoor, and an indoor control portion 24 that controls the indoor blower 21. The indoor control portion 24 controls the indoor blower 21 to perform a blowing process for diffusing a leaked refrigerant in accordance with the instruction signal in the case of receiving the instruction signal from the information processing portion 31. In the case of detecting a leakage of a refrigerant in the indoor, the information processing portion 31 transmits the instruction signal to one or more indoor units 2 of the indoor collectively, and the indoor blowers 21 of the respective indoor units 2 perform the blowing process in accordance with the instruction signal, so that the diffusion of a refrigerant in the indoor is promoted more. Thus, the concentration of a refrigerant in the indoor is suppressed from rising.

[0075] The information processing portion 31 in the embodiment transmits an instruction signal for executing a predetermined action in the case of a refrigerant leakage to one or more indoor units 2 of the indoor in which a leakage of a refrigerant is detected from the refrigerant leakage sensor 5 that detects a leakage of a refrigerant in the indoor. The indoor unit 2 is provided with an indoor blower 21 that blows air into the indoor, and an indoor control portion 24 that controls the indoor blower 21. The indoor control portion 24 controls the indoor blower 21 to perform a blowing process for diffusing a leaked refrigerant in accordance with the instruction signal in the case of receiving the instruction signal from the information processing portion 31. In the case of detecting a leakage of a refrigerant in the indoor, the information processing portion 31 transmits the instruction signal to one or more indoor units 2 of the indoor collectively, and the indoor blowers 21 of the respective indoor units 2 perform the blowing process in accordance with the instruction signal, so that the diffusion of a refrigerant in the indoor is promoted more. Thus, the concentration of a refrigerant in the indoor is suppressed from rising.

[0076] BRIEF DESCRIPTION OF DRAWINGS

[0077] 1…outdoor unit; 2, 6…indoor unit; 3…shut-off valve unit; 4…refrigerant circuit; 5…refrigerant leakage sensor; 7…refrigerant piping; 10…compressor; 11…flow path switching device; 12…outdoor heat exchanger; 13…outdoor blower; 14…outdoor flow rate adjustment valve; 20…indoor heat exchanger; 21…indoor blower; 22…indoor flow rate adjustment valve; 23…notification portion; 24, 60…indoor control portion; 30…shut-off valve; 31…information processing portion; 100, 101…air conditioning system.

Claims

1. An air conditioning system, characterized by, Having: an outdoor unit that exchanges heat between air outside and a refrigerant circulating in a refrigerant circuit in which the refrigerant circulates; a plurality of indoor units that exchange heat between the refrigerant and air in a room in the refrigerant circuit to perform air conditioning in the room; one or more refrigerant leakage sensors that detect leakage of the refrigerant from the refrigerant circuit; and one or more shutoff valve units that are provided in the refrigerant circuit between the outdoor unit and one or more of the indoor units, contain a plurality of shutoff valves that shut off inflow of the refrigerant to the plurality of indoor units in the event of leakage of the refrigerant, and house the plurality of shutoff valves in a housing, the refrigerant leakage sensors are provided separately from the outdoor unit and the plurality of indoor units, the shutoff valve units include an information processing portion that controls the plurality of shutoff valves contained in the shutoff valve units, and house the information processing portion inside the housing, the refrigerant leakage sensors transmit a signal indicating leakage of the refrigerant to the information processing portion in the event of detection of leakage of the refrigerant in the room, the information processing portion controls the plurality of shutoff valves that shut off inflow of the refrigerant to one or more of the indoor units provided in each room as one group, transmits an instruction signal for performing a predetermined action in the event of leakage of the refrigerant to the plurality of shutoff valves contained in the group including the shutoff valves that shut off inflow of the refrigerant to one or more of the indoor units in the room in the event of reception of the signal indicating leakage of the refrigerant from the refrigerant leakage sensor that detected leakage of the refrigerant in the room, and transmits the instruction signal for performing a predetermined action in the event of leakage of the refrigerant to the outdoor unit, the indoor units include: a notification portion that notifies of leakage of the refrigerant; and an indoor control portion that controls the notification portion, the indoor units transmit a control signal for controlling the outdoor unit to the outdoor unit, the indoor units do not transmit the control signal for controlling the outdoor unit to the outdoor unit in the event of reception of the instruction signal according to the instruction signal, the outdoor unit stops an action according to the instruction signal in the event of reception of the instruction signal even in the event of reception of the control signal, the indoor control portion controls the notification portion according to the instruction signal in the event of reception of the instruction signal from the information processing portion so as to notify of leakage of the refrigerant.

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