air conditioner

Abstract

To provide an air conditioner capable of improving the safety when restarting the operation.SOLUTION: An air conditioner 10 includes a refrigeration cycle 320, a control part 310, and a communication part 140. The refrigeration cycle 320 circulates refrigerant between an indoor unit 100 and an outdoor unit 200. The control part 310 controls the operation of the refrigeration cycle 320. The communication part 140 receives a danger information signal. When the communication part 140 receives the danger information signal, the control part 310 allows the refrigeration cycle 320 to perform pump-down operation to seal refrigerant into the outdoor unit 200, and then performs refrigerant leakage detecting operation to detect whether the refrigerant leaks or not from the refrigeration cycle 320, before the control part 310 allows the operation of the refrigeration cycle 320 to be restarted.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an air conditioner. [Background technology]

[0002] The air conditioner control device described in Patent Document 1, upon receiving an earthquake early warning signal, fully closes the expansion valve and performs pump-down operation to seal the refrigerant in the outdoor unit. If the seismic intensity is high, the control device stops the compressor and closes the four-way valve. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-144991 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology of Patent Document 1 does not provide sufficient safety measures when restarting operations.

[0005] An object of the present invention is to provide an air conditioner that can improve safety when restarting operation. [Means for solving the problem]

[0006] The air conditioner of the present invention comprises a refrigeration cycle, a control unit, and a communication unit. The refrigeration cycle circulates a refrigerant between an indoor unit and an outdoor unit. The control unit controls the operation of the refrigeration cycle. The communication unit receives a danger notification signal. When the communication unit receives the danger notification signal, the control unit causes the refrigeration cycle to perform a pump-down operation to seal the refrigerant in the outdoor unit, and further performs a refrigerant leak detection operation to detect whether or not there is a leak of the refrigerant from the refrigeration cycle before the control unit resumes operation of the refrigeration cycle. [Effects of the Invention]

[0007] According to the present invention, an air conditioner is provided that can improve safety when restarting operation. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of the configuration of an air conditioner according to an embodiment. [Figure 2] FIG. 1 is a diagram showing an example of the configuration of a refrigeration cycle. [Figure 3] 10 is a flowchart illustrating an example of the operation of a control unit. [Figure 4] This is a flowchart continuing from Figure 3. [Figure 5] 10 is a flowchart showing the flow of processing for pump-down operation. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings, in which the same or corresponding parts are designated by the same reference numerals and will not be described repeatedly.

[0010] First, the configuration of an air conditioner 10 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example of the configuration of the air conditioner 10.

[0011] As shown in FIG. 1, the air conditioner 10 includes an indoor unit 100, a remote control 105, and an outdoor unit 200.

[0012] The indoor unit 100 includes an indoor control unit 110, a remote control transmitting / receiving unit 120, an indoor fan motor 130, a communication unit 140, and an indoor environment detection unit 150. The outdoor unit 200 includes an outdoor control unit 210, an outdoor fan motor 220, a compressor 230, an expansion valve 240, a four-way valve 250, a suction solenoid valve 260, and an outdoor environment detection unit 270. Of these, the indoor fan motor 130, the outdoor fan motor 220, the compressor 230, the expansion valve 240, the four-way valve 250, and the suction solenoid valve 260 constitute part of a refrigeration cycle 320 that circulates a refrigerant between the indoor unit 100 and the outdoor unit 200.

[0013] The indoor control unit 110 has an indoor operation control unit 111 and an indoor command transmission unit 112. The outdoor control unit 210 has an outdoor operation control unit 211 and an outdoor command transmission unit 212. The indoor command transmission unit 112 transmits control commands to the indoor fan motor 130. The outdoor command transmission unit 212 transmits control commands to each of the outdoor fan motor 220, the compressor 230, the expansion valve 240, the four-way valve 250, and the suction solenoid valve 260.

[0014] The indoor control unit 110 and the outdoor control unit 210 cooperate with each other to operate as a single control unit 310. The control unit 310 includes a processor such as a CPU (Central Processing Unit) and a storage unit. The storage unit of the control unit 310 includes a storage device such as a semiconductor memory, and stores data and computer programs. The processor of the control unit 310 controls each component of the air conditioner 10, including the refrigeration cycle 320, by executing the computer program stored in the storage unit.

[0015] The remote control 105 displays the operation mode of the air conditioner 10 and accepts operation instructions. The remote control transmitter / receiver 120 controls the exchange of signals between the indoor operation control unit 111 and the remote control 105.

[0016] The communication unit 140 is responsible for transmitting and receiving signals between the indoor operation control unit 111 and the communication network. The communication unit 140 receives, for example, an earthquake early warning signal or a fire alarm signal. When the communication unit 140 receives an earthquake early warning signal, the communication unit 140 also receives a seismic intensity information signal. The earthquake early warning signal or the fire alarm signal is an example of a "danger notification signal."

[0017] The indoor environment detection unit 150 includes a room temperature sensor 151 and an indoor heat exchanger temperature sensor 152. The outdoor environment detection unit 270 includes an outside air temperature sensor 271, an outdoor heat exchanger temperature sensor 272, a discharge temperature sensor 273, a suction temperature sensor 274, and a two-way valve temperature sensor 275.

[0018] Next, the overall configuration of the refrigeration cycle 320 will be described with reference to Figures 1 and 2. Figure 2 is a diagram showing an example of the configuration of the refrigeration cycle 320.

[0019] 2, the refrigeration cycle 320 further includes an indoor heat exchanger 160, an outdoor heat exchanger 280, a two-way valve 291, and a three-way valve 292. Arrow D1 indicates the direction in which the refrigerant flows in the cooling cycle. The refrigerant flow path, along arrow D1, runs from the compressor 230 through the four-way valve 250, the outdoor heat exchanger 280, the expansion valve 240, the two-way valve 291, the indoor heat exchanger 160, the three-way valve 292, the suction solenoid valve 260, and the four-way valve 250, before returning to the compressor 230. The refrigerant flows in the heating cycle in the opposite direction to the arrow D1.

[0020] The two-way valve 291 and the three-way valve 292 are arranged at the refrigerant inlet and outlet of the outdoor unit 200. The two-way valve 291 and the three-way valve 292 are both manually opened when the air conditioner 10 is installed.

[0021] Next, the operation of control unit 310 will be described with reference to Figures 1 to 4. Figure 3 is a flowchart showing an example of the operation of control unit 310. Figure 4 is a flowchart following Figure 3.

[0022] 3, the control unit 310 determines whether the communication unit 140 has received a danger notification signal. If the control unit 310 determines that the communication unit 140 has received a danger notification signal (Yes in step S101), the process of the control unit 310 proceeds to step S103. If the control unit 310 determines that the communication unit 140 has not received a danger notification signal (No in step S101), the process of the control unit 310 remains at step S101.

[0023] Step S103: The control unit 310 determines whether the state of the air conditioner 10 satisfies a first condition. The first condition is, for example, that the air conditioner 10 has been "stopped" and the "indoor temperature > outdoor temperature" has continued for 12 hours or more. The indoor temperature is detected by the room temperature sensor 151. The outdoor temperature is detected by the outdoor air temperature sensor 271. If the control unit 310 determines that the state of the air conditioner 10 satisfies the first condition (Yes in step S103), the processing of the control unit 310 proceeds to step S113. If the control unit 310 determines that the state of the air conditioner 10 does not satisfy the first condition (No in step S103), the processing of the control unit 310 proceeds to step S105.

[0024] When the air conditioner 10 is stopped, the refrigerant accumulates in either the indoor unit 100 or the outdoor unit 200, whichever unit has a lower ambient temperature. If the outdoor temperature is lower than the indoor temperature, the refrigerant accumulates in the outdoor unit 200. If the stopped state has continued for 12 hours or more, a large amount of refrigerant has already accumulated in the outdoor unit 200, so there is no need to perform pump-down operation, and the processing of the control unit 310 proceeds to step S113.

[0025] Step S105: The control unit 310 determines whether the air conditioner 10 is in heating operation. If the control unit 310 determines that the air conditioner 10 is in heating operation (Yes in step S105), the processing by the control unit 310 proceeds to step S107. If the control unit 310 determines that the air conditioner 10 is not in heating operation (No in step S105), the processing by the control unit 310 proceeds to step S111.

[0026] Step S107: The control unit 310 fully opens the expansion valve 240 for a predetermined time. During heating operation, a large amount of refrigerant accumulates in the indoor unit 100, and the refrigerant pressure on the indoor unit 100 side is higher than on the outdoor unit 200 side. Therefore, simply by fully opening the expansion valve 240, the refrigerant flows from the indoor unit 100 to the outdoor unit 200. At this time, the control unit 310 may control the rotation speed of the outdoor fan motor 220 to the maximum for, for example, 10 seconds. This further cools the liquid refrigerant sent to the outdoor unit 200, making it easier to maintain a liquid phase state. When the processing of step S107 is completed, the processing of the control unit 310 proceeds to step S109.

[0027] Step S109: The control unit 310 switches the refrigeration cycle 320 from the heating cycle to the cooling cycle. In step S107, the control unit 310 opens the expansion valve 240 to reduce the pressure difference between the indoor unit 100 and the outdoor unit 200, and then in step S109, switches the four-way valve 250 to the cooling side. If the four-way valve 250 is suddenly switched to the cooling side from the heating cycle when the rotation speed of the compressor 230 is high, the compressor 230 may become overloaded, causing an error such as an overcurrent. Therefore, it is preferable that the control unit 310 reduces the rotation speed of the compressor 230 to a predetermined rotation speed before switching the four-way valve 250 to the cooling side. When the processing of step S109 is completed, the processing of the control unit 310 proceeds to step S111.

[0028] Step S111: The control unit 310 causes the refrigeration cycle 320 to perform a pump-down operation (see the subroutine shown in FIG. 5). When the process of step S111 is completed, the process of the control unit 310 proceeds to step S115.

[0029] Step S113: The control unit 310 fully closes the expansion valve 240. The control unit 310 also fully closes the suction solenoid valve 260 to stop operation of the air conditioner 10. When the processing of step S113 is completed, the processing of the control unit 310 proceeds to step S115.

[0030] Step S115: After carrying out the protective operation corresponding to the danger notification signal or more, the control unit 310 determines whether the environment of the air conditioner 10 satisfies the protection cancellation conditions. If the danger notification signal is an earthquake early warning signal, the protection cancellation condition is that the communication unit 140 has further received a seismic intensity information signal. If the danger notification signal is a fire alarm signal, the protection cancellation condition is that the fire alarm has stopped. If the control unit 310 determines that the environment of the air conditioner 10 satisfies the protection cancellation conditions (Yes in step S115), the processing of the control unit 310 proceeds to step S117. If the control unit 310 determines that the environment of the air conditioner 10 does not satisfy the protection cancellation conditions (No in step S115), the processing of the control unit 310 remains at step S115.

[0031] Step S117: The control unit 310 starts the protection cancellation operation described below. When the process of step S117 is completed, the process of the control unit 310 proceeds to step S119 (see FIG. 4).

[0032] Step S119: As shown in FIG. 4, the control unit 310 determines whether the danger level is low. If the danger notification signal is an earthquake early warning signal, for example, a seismic intensity of 5 or higher is determined to be a high level of danger, a seismic intensity of 3 to 4 is determined to be a medium level of danger, and a seismic intensity of 2 or lower is determined to be a low level of danger. If the danger notification signal is a fire alarm signal, for example, heat detection is determined to be a high level of danger, smoke detection is determined to be a medium level of danger, and no heat or smoke detection is determined to be a low level of danger. If the control unit 310 determines that the danger level is low (Yes in step S119), the processing of the control unit 310 proceeds to step S131. If the control unit 310 determines that the danger level is not low (No in step S119), the processing of the control unit 310 proceeds to step S121.

[0033] Step S121: The control unit 310 performs a refrigerant leak detection operation to detect the presence or absence of a refrigerant leak from the refrigeration cycle 320. At this time, the control unit 310 operates the refrigeration cycle 320 in the same cycle (cooling or heating) as when the communication unit 140 received the danger notification signal, but under operation setting conditions that are less stringent than the operation setting conditions as when the communication unit 140 received the danger notification signal. Specifically, the control unit 310 fixes the rotation speeds of the compressor 230, the indoor fan motor 130, and the outdoor fan motor 220 to reduced predetermined rotation speeds in the same operation mode as the original operation mode. While the control unit 310 is performing the refrigerant leak detection operation, it does not accept an operation restart command from the remote control 105. When the processing of step S121 is completed, the processing of the control unit 310 proceeds to step S123.

[0034] Step S123: Control unit 310 determines whether a refrigerant leak has been detected. If control unit 310 determines that a refrigerant leak has been detected (Yes in step S123), the process by control unit 310 proceeds to step S133. If control unit 310 determines that a refrigerant leak has not been detected (No in step S123), the process by control unit 310 proceeds to step S125.

[0035] For example, the control unit 310 determines that a refrigerant leak has occurred if the expansion valve 240 has opened 50 steps or more in the five minutes between 30 minutes and 35 minutes after the start of the refrigerant leak detection operation. Alternatively, in the cooling mode, the control unit 310 may determine that a refrigerant leak has occurred when the condition "temperature detected by the outdoor heat exchanger temperature sensor 272 - temperature detected by the outdoor air temperature sensor 271" > 5°C is met. In the heating mode, the control unit 310 may determine that a refrigerant leak has occurred when the condition "temperature detected by the indoor heat exchanger temperature sensor 152 - temperature detected by the two-way valve temperature sensor 275" < 5°C is met.

[0036] Step S125: Control unit 310 determines whether the risk level is high. If control unit 310 determines that the risk level is high (Yes in step S125), the process by control unit 310 proceeds to step S127. If control unit 310 determines that the risk level is not high (No in step S125), the process by control unit 310 proceeds to step S131.

[0037] Step S127: The control unit 310 notifies the administrator of the confirmation of the protection release. When the process of step S127 is completed, the process of the control unit 310 proceeds to step S129.

[0038] Step S129: Control unit 310 determines whether or not the administrator has permitted removal of protection. If control unit 310 determines that removal of protection has been permitted (Yes in step S129), the process by control unit 310 proceeds to step S131. If control unit 310 determines that removal of protection has not been permitted (No in step S129), the process by control unit 310 proceeds to step S135.

[0039] Step S131: The control unit 310 notifies the administrator that operation has resumed, and returns the air conditioner 10 to the state it was in before protective operation. That is, the control unit 310 resumes operation in the same operation mode as when the communication unit 140 received the danger notification signal. When the processing of step S131 is completed, the processing of the control unit 310 ends.

[0040] Step S133: The control unit 310 notifies the administrator of the refrigerant leak. When the process of step S133 is completed, the process of the control unit 310 proceeds to step S135.

[0041] Step S135: The control unit 310 stops the operation of the air conditioner 10. When the process of step S135 is completed, the process of the control unit 310 ends.

[0042] Next, the pump-down operation will be described with reference to Figures 1 to 5. Figure 5 is a flowchart showing the flow of processing in the pump-down operation.

[0043] Step S201: As shown in Fig. 5, the control unit 310 fully closes the expansion valve 240. When the process of step S201 is completed, the process of the control unit 310 proceeds to step S203.

[0044] Step S203: The control unit 310 performs pump-down promotion operation. The pump-down promotion operation is an operation that promotes pump-down operation in order to quickly complete pump-down operation, which is normally performed under medium load conditions when the air conditioner 10 is relocated. To this end, the control unit 310 increases the rotation speed of the compressor 230 to its maximum rotation speed. The control unit 310 also stops the indoor fan motor 130, while increasing the rotation speed of the outdoor fan motor 220 to its maximum rotation speed. When the processing of step S203 is completed, the processing of the control unit 310 proceeds to step S205.

[0045] Step S205: Control unit 310 determines whether a predetermined time has elapsed. If control unit 310 determines that the predetermined time has elapsed (Yes in step S205), the process of control unit 310 proceeds to step S207. If control unit 310 determines that the predetermined time has not elapsed (No in step S205), the process of control unit 310 remains at step S205.

[0046] Step S207: The control unit 310 fully closes the suction electromagnetic valve 260 to stop operation of the air conditioner 10. When the processing of step S207 is completed, the processing of the control unit 310 ends.

[0047] According to the embodiment, when the communication unit 140 receives the danger notification signal, the control unit 310 causes the refrigeration cycle 320 to perform a pump-down operation to seal a refrigerant in the outdoor unit 200. Furthermore, before the control unit 310 resumes operation of the refrigeration cycle 320, it performs a refrigerant leak detection operation to detect whether or not there is a refrigerant leak from the refrigeration cycle 320. Therefore, according to the embodiment, an air conditioner 10 is provided that can improve safety when operation is resumed.

[0048] In particular, even if the refrigerant leak detection operation detects that there is no refrigerant leak, if the danger level is determined to be high in relation to the danger notification signal, the control unit 310 will not resume operation of the air conditioner 10. However, if the danger level is determined to be high, the control unit 310 will resume operation of the air conditioner 10 if the refrigerant leak detection operation detects that there is no refrigerant leak and permission to resume operation is obtained.

[0049] The above-described embodiments are preferred embodiments of the present invention, and therefore may include various technically preferable limitations. However, the technical scope of the present invention is not limited to these aspects unless otherwise specified. In other words, the components in the above-described embodiments can be appropriately replaced with existing components, and various variations, including combinations with other existing components, are possible. The description of the above-described embodiments does not limit the content of the invention described in the claims. [Industrial Applicability]

[0050] The present invention can be used in the field of air conditioners. [Explanation of symbols]

[0051] 10 Air conditioner 100 Indoor unit 140 Communications Department 200 outdoor unit 240 Expansion valve 310 Control Unit 320 Refrigeration Cycle

Claims

1. A refrigeration cycle that circulates a refrigerant between an indoor unit and an outdoor unit; a control unit for controlling the operation of the refrigeration cycle; a communication unit that receives a danger notification signal; Equipped with When the communication unit receives the danger notification signal, the control unit causes the refrigeration cycle to perform a pump-down operation to seal the refrigerant in the outdoor unit, and further performs a refrigerant leak detection operation to detect whether or not the refrigerant is leaking from the refrigeration cycle before the control unit resumes operation of the refrigeration cycle. The control unit does not resume operation of the air conditioner if the danger level is determined to be high in relation to the danger notification signal, even if the refrigerant leak detection operation detects that there is no refrigerant leak.

2. A refrigeration cycle that circulates a refrigerant between an indoor unit and an outdoor unit; a control unit for controlling the operation of the refrigeration cycle; a communication unit that receives a danger notification signal; Equipped with When the communication unit receives the danger notification signal, the control unit causes the refrigeration cycle to perform a pump-down operation to seal the refrigerant in the outdoor unit, and further performs a refrigerant leak detection operation to detect whether or not the refrigerant is leaking from the refrigeration cycle before the control unit resumes operation of the refrigeration cycle. When the control unit determines that the level of danger is high in relation to the danger notification signal, the control unit resumes operation when the refrigerant leak detection operation detects that there is no refrigerant leak and permission to resume operation is obtained.

3. A refrigeration cycle that circulates a refrigerant between an indoor unit and an outdoor unit; a control unit for controlling the operation of the refrigeration cycle; a communication unit that receives a danger notification signal; Equipped with When the communication unit receives the danger notification signal, the control unit causes the refrigeration cycle to perform a pump-down operation to seal the refrigerant in the outdoor unit, and further performs a refrigerant leak detection operation to detect whether or not the refrigerant is leaking from the refrigeration cycle before the control unit resumes operation of the refrigeration cycle. When the communication unit receives the danger warning signal while the refrigeration cycle is operating in the heating cycle, the control unit fully opens an expansion valve of the refrigeration cycle for a predetermined period of time while the refrigeration cycle is operating in the heating cycle, and then switches the refrigeration cycle to a cooling cycle and performs the pump-down operation.

4. The air conditioner according to any one of claims 1 to 3, wherein the danger notification signal is an emergency earthquake warning signal or a fire alarm signal.

5. 5. The air conditioner according to claim 1, wherein, during the refrigerant leak detection operation, the control unit operates the refrigeration cycle in the same cycle as when the communication unit received the danger notification signal.

6. The air conditioner according to claim 5, wherein the control unit operates the refrigeration cycle under operation setting conditions that are more relaxed than the operation setting conditions of the refrigeration cycle when the communication unit received the danger notification signal during the refrigerant leak detection operation.

7. The air conditioner according to claim 1 , wherein the control unit does not accept an instruction to restart operation while the refrigerant leak detection operation is being performed.

8. 8. The air conditioner according to claim 1, wherein, when the refrigerant leak detection operation detects that there is no refrigerant leak, the control unit resumes operation in the same operating mode as when the communication unit received the danger notification signal.

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