air conditioner

Abstract

This air conditioner provides a system that enables air conditioning operation using both the outdoor unit and a functioning indoor unit, even when an abnormality is detected in the indoor unit. [Solution] The air conditioner 10 comprises an outdoor unit 2, a plurality of indoor units 1,1', and a control device 9 that controls the outdoor unit 2 and the plurality of indoor units 1,1'. The indoor units 1,1' are equipped with indoor control valves 6 that adjust the flow rate of refrigerant flowing through the indoor units 1,1'. The control device 9 comprises an abnormality detection unit that detects abnormalities in at least the indoor units 1,1', a function restriction unit that restricts the functions of the outdoor unit 2 and / or the plurality of indoor units 1,1' when a predetermined abnormality is detected by the abnormality detection unit, and a restriction release unit that determines whether pump-down operation is possible and, if it is determined that pump-down operation is possible, releases the function restriction by the function restriction unit. The control device 9 performs control related to pump-down operation, and thereafter performs control to close the indoor control valve 6 of the indoor unit 1' in which an abnormality was detected.

Description

Technical Field

[0001] This disclosure relates to an air conditioner.

Background Art

[0002] For store air conditioners, multiple indoor units can be connected according to the capacity of the outdoor unit. Since this type of air conditioner operates multiple indoor units simultaneously, if any one or more indoor units fail or an alarm (abnormality detection) associated with it is reported, the air conditioning operation becomes impossible.

[0003] Patent Document 1 discloses an air conditioner capable of performing a refrigerant recovery operation (pump-down operation) in a state where a control valve is closed to stop the circulation of refrigerant gas from the outdoor unit to the indoor unit upon receiving a signal from a refrigerant gas sensor when refrigerant gas leaks from an indoor unit. Thereby, the pump-down operation can be carried out when the air conditioning operation is impossible, preventing the release of refrigerant gas into the atmosphere.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the air conditioning operation becomes impossible, the air conditioning operation cannot be used unless the failed indoor unit is restored or the abnormality detection is resolved, resulting in a significant reduction in comfort. Therefore, it is desired to enable the air conditioning operation between the outdoor unit and normal indoor units even when an abnormality in an indoor unit is detected.

[0006] An object of this disclosure is to provide an air conditioner that enables the air conditioning operation between the outdoor unit and normal indoor units even when an abnormality in an indoor unit is detected.

Means for Solving the Problems

[0007] The air conditioner disclosed herein is Outdoor unit and Multiple indoor units, The system comprises the outdoor unit and the control device for controlling the plurality of indoor units, The indoor unit is equipped with an indoor control valve that adjusts the flow rate of the refrigerant flowing through the indoor unit. The control device is At least an abnormality detection unit that detects an abnormality in the indoor unit, A function limiting unit that restricts the functions of the outdoor unit and the plurality of indoor units when a predetermined abnormality is detected by the abnormality detection unit, The system includes a function release unit that determines whether pump-down operation is possible and, if it determines that pump-down operation is possible, releases the function restriction imposed by the function limiting unit, The control device performs control related to the pump-down operation, and then performs control to close the indoor control valve of the indoor unit where an abnormality has been detected. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram showing the refrigeration cycle of an air conditioner according to one embodiment. [Figure 2] Figure 2 is a flowchart showing the operation of the air conditioner up to the backup operation according to the same embodiment. [Modes for carrying out the invention]

[0009] An air conditioner (refrigeration cycle device) according to one embodiment will be described with reference to Figure 1. Note that the dimensional ratios in Figure 1 do not necessarily match the actual dimensional ratios. Figure 1 is a configuration diagram showing the refrigeration cycle of the air conditioner 10.

[0010] As shown in Figure 1, the air conditioner 10 is, for example, a packaged air conditioner or a multi-split air conditioner for buildings. Figure 1 shows an example where the air conditioner 10 is a packaged air conditioner. The arrows shown in Figure 1 indicate the flow of refrigerant during pump-down operation (cooling operation).

[0011] The air conditioner 10 comprises an outdoor unit 2 and multiple indoor units 1,1'. Figure 1 shows an example where multiple indoor units 1,1' are connected to one outdoor unit 2, but it is not limited to this. For example, multiple outdoor units may be connected to multiple indoor units. Also, Figure 1 shows an example where one of the multiple indoor units 1,1' has failed, but it is not limited to this. For example, even if two or more of the multiple indoor units have failed, the air conditioner 10 can perform backup operation as described later.

[0012] The outdoor unit 2 and the multiple indoor units 1,1' are connected by refrigerant piping (liquid connection pipe 12 and gas connection pipe 13). A liquid-side shut-off valve (not shown) is provided on the outdoor unit 2 side of the liquid connection pipe 12, and a gas-side shut-off valve (not shown) is provided on the outdoor unit 2 side of the gas connection pipe 13. The liquid-side shut-off valve and the gas-side shut-off valve are, for example, manual valves, and when they are opened after the installation of the air conditioner 10, the refrigerant that was sealed in the outdoor unit 2 at the time of shipment is filled into the indoor units 1,1'.

[0013] The outdoor unit 2 includes a four-way valve (not shown), a compressor 3, an outdoor heat exchanger 4, an outdoor fan 14, and an outdoor control valve 5. The compressor 3 is, for example, a scroll compressor, a rotary compressor, or a swing compressor. Each of the indoor units 1,1' includes an indoor heat exchanger 7, an indoor fan 15, and an indoor control valve 6.

[0014] The four-way valve switches the refrigerant flow path according to the operating mode of the air conditioner 10. Switching the four-way valve results in a refrigeration cycle during cooling operation in the order of compressor 3, outdoor heat exchanger 4 (condenser), outdoor control valve 5, indoor control valve 6, and indoor heat exchanger 7 (evaporator), as shown by the solid arrows. Switching the four-way valve also results in a refrigeration cycle during heating operation in the order of compressor 3, indoor heat exchanger 7 (condenser), indoor control valve 6, outdoor control valve 5, and outdoor heat exchanger 4 (evaporator).

[0015] The outdoor heat exchanger 4 performs heat exchange between the refrigerant and the outside air using the outdoor fan 14, and acts as a condenser during cooling operation and as an evaporator during heating operation. The outdoor control valve 5 is an expansion valve or refrigerant shut-off valve, and is composed of, for example, an electronically controlled valve or a temperature-controlled valve, and is a valve that adjusts the flow rate of refrigerant flowing to the indoor heat exchanger 7 and the outdoor heat exchanger 4. The outdoor control valve 5 acts as a pressure reducer during cooling operation.

[0016] The indoor heat exchanger 7 performs heat exchange between the refrigerant and the indoor air using the indoor fan 15, and acts as an evaporator during cooling operation and as a condenser during heating operation. The indoor control valve 6 is an expansion valve or refrigerant shut-off valve, and is composed of, for example, an electronically controlled valve or a temperature-controlled valve, and is a valve that adjusts the flow rate of the refrigerant flowing through the indoor heat exchanger 7. The indoor control valve 6 acts as a pressure reducer during heating operation.

[0017] The cooling operation of the air conditioner 10 is carried out according to the following principle: The high-temperature, high-pressure refrigerant gas compressed by the compressor 3 is sent to the outdoor heat exchanger 4 through a four-way valve. The refrigerant gas is then cooled by heat exchange with the outside air in the outdoor heat exchanger 4, which acts as a condenser, and becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is depressurized and expanded by the outdoor control valve 5, becoming a gas-liquid two-phase refrigerant (a low-temperature, low-pressure liquid refrigerant containing a small amount of refrigerant gas).

[0018] The gas-liquid two-phase refrigerant depressurized by the outdoor control valve 5 is sent to each indoor heat exchanger 7. Then, in the indoor heat exchanger 7 acting as an evaporator, it evaporates by exchanging heat with the indoor air,夺取heat and becomes a low-temperature and low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant returns to the compressor 3 through the four-way valve. Thereafter, the same cycle is repeated to continue the cooling operation.

[0019] The heating operation by the air conditioner 10 is performed in a cycle opposite to that during the cooling operation. The high-temperature and high-pressure refrigerant gas compressed by the compressor 3 is sent to each indoor heat exchanger 7 by switching the four-way valve. Then, in the indoor heat exchanger 7 acting as a condenser, heat is given to the indoor air, and thereafter, heat is夺取from the outside air by the outdoor heat exchanger 4 acting as an evaporator. Such a similar cycle is repeated to continue the heating operation.

[0020] The pump-down operation by the air conditioner 10 is an operation to collect the refrigerant on the side of all the indoor units 1, 1' on the side of the outdoor unit 2. The pump-down operation is an operation in which the above-described cooling operation is performed with the outdoor control valve 5 (which may also be a liquid-side blocking valve) closed. The flow of the refrigerant during the pump-down operation is the same as the flow of the refrigerant during the cooling operation (the arrow in FIG. 1). The refrigerant liquefied by the outdoor heat exchanger 4 acting as a condenser is stored on the side of the outdoor unit 2 without being supplied to the indoor units 1, 1' because the outdoor control valve 5 is closed.

[0021] Each of the indoor units 1, 1' includes an indoor pressure sensor (not shown) for measuring the pressure of the refrigerant in the indoor unit 1, 1', an indoor suction temperature sensor (not shown) for measuring the indoor temperature, an indoor blown temperature sensor (not shown) for measuring the temperature blown out from the indoor unit 1, 1', and a remote control 11 for operating the indoor unit 1, 1'.

[0022] The air conditioner 10 includes a control device 9 for controlling the outdoor unit 2 and the plurality of indoor units 1, 1'. The air conditioner 10 can perform a cooling operation, a heating operation, and a pump-down operation by controlling the outdoor unit 2 and the plurality of indoor units 1, 1' with the control device 9. The control device 9 is provided in the outdoor unit 2 and / or each of the indoor units 1, 1'.

[0023] The control device 9 is equipped with an abnormality detection unit that detects abnormalities in at least the indoor units 1,1'. The abnormality detection unit can detect, for example, insufficient capacity of the indoor units 1,1', errors in the electrical wiring on the indoor unit 1,1' side, abnormalities in the transmission of control signals, failure of the indoor fan 15, failure of the indoor control valve 6, refrigerant leakage in the indoor units 1,1', failure of the control board, failure of the temperature sensor, failure of the pressure sensor, etc.

[0024] The abnormality detection unit detects abnormalities in the indoor units 1 and 1' based on the measured values ​​of indoor temperature sensors (indoor intake temperature sensor and indoor outlet temperature sensor) and / or indoor pressure sensors provided on the indoor units 1 and 1'. A malfunction of the indoor fan 15 can be detected, for example, by the temperature measured by the indoor intake temperature sensor and indoor outlet temperature sensor. A malfunction of the indoor control valve 6 can be detected, for example, by the pressure measured by the indoor pressure sensor.

[0025] The control device 9 includes a function restriction unit that restricts the functions of the outdoor unit 2 and the multiple indoor units 1,1' when a predetermined abnormality is detected by the abnormality detection unit. The function restriction unit restricts the functions of the outdoor unit 2 and the multiple indoor units 1,1' so that, for example, cooling operation, heating operation and pump-down operation cannot be performed. The predetermined abnormality is a malfunction of the indoor fan 15, indoor intake temperature sensor, indoor discharge temperature sensor, etc., which is an abnormality that interferes with air conditioning operation.

[0026] The control device 9 determines whether a pump-down operation is possible and, if it determines that a pump-down operation is possible, includes a restriction release unit that releases the restriction on the function by the function restriction unit. This makes it possible to perform a pump-down operation even if the function of the air conditioner 10 is restricted when an abnormality occurs. As a result, by performing a pump-down operation and returning all refrigerant, including the refrigerant in the indoor unit 1' where the abnormality was detected, to the outdoor unit 2, a refrigerant shortage during backup operation can be prevented.

[0027] The restriction release unit, for example, identifies the fault location and determines that pump-down operation is possible if the fault is of a predetermined severity that will not damage any of the components of the air conditioner 10 (excluding components where an abnormality has been detected) by pump-down operation. The predetermined faults include failures of the indoor fan 15, the indoor intake temperature sensor, the indoor discharge temperature sensor, and so on.

[0028] When the function restriction by the function limiting unit is released, the control device 9 preferably controls the outdoor unit 2 and the multiple indoor units 1,1' within a predetermined limit range. This allows the pump-down operation to be performed within a range where no components are damaged by controlling the outdoor unit 2 and the multiple indoor units 1,1'.

[0029] Controlling the outdoor unit 2 and the multiple indoor units 1,1' within a predetermined limit range means controlling the load on each component of the outdoor unit 2 and the multiple indoor units 1,1' to be less than during normal operation. For example, the control device 9 controls the frequency of the compressor 3 to be lower than during normal operation, controls the opening of the outdoor control valve 5 and / or indoor control valve 6 to be smaller (or larger) than during normal operation, and controls the rotational speed of the outdoor fan 14 and / or indoor fan 15 to be lower than during normal operation.

[0030] When the restriction on the function by the restriction release unit is released, the control device 9 closes (fully closes) the outdoor control valve 5 (or liquid side blocking valve) and performs control related to pump-down operation (cooling operation).

[0031] After the pump-down operation, the control device 9 opens the outdoor control valve 5 and closes the indoor control valve 6 of the indoor unit 1' in which an abnormality was detected. With this configuration, even when an abnormality is detected in the indoor unit 1', air conditioning operation (backup operation) is possible with the normal indoor unit 1 and the outdoor unit 2, excluding the indoor unit 1' in which the abnormality was detected.

[0032] In this embodiment, backup operation refers to air conditioning operation (cooling or heating operation) performed by the normal indoor unit 1 and outdoor unit 2, excluding the indoor unit 1' in which an abnormality has been detected. During backup operation, the control device 9 performs cycle control considering the capacity change due to the exclusion of the indoor unit 1' in which an abnormality has been detected. The control device 9 can perform cycle control, for example, by controlling the refrigerant flow rate and compressor frequency according to the number of rooms and the indoor / outdoor capacity ratio.

[0033] It is preferable that pump-down and backup operations can be performed by operating the remote control 11 (or an information terminal). This allows occupants to perform pump-down and backup operations, improving comfort.

[0034] The remote control 11 preferably includes a display unit (not shown) that indicates that backup operation is in progress. With such a configuration, it is possible to inform occupants that backup operation is in progress.

[0035] The control device 9 preferably includes a storage unit (not shown) for storing abnormalities detected by the abnormality detection unit. The air conditioner 10 preferably includes a notification unit (not shown) for notifying the abnormality detected by the abnormality detection unit. The notification unit notifies (displays) the details of the abnormality (alarm) on a display unit such as the remote control 11 or an information terminal. The notification unit may also be a buzzer that sounds a warning.

[0036] Next, we will explain an example of the operation of an air conditioner up to backup operation, referring to Figure 2. Figure 2 is a flowchart showing the operation of an air conditioner up to backup operation.

[0037] As shown in Figure 2, first, an abnormality in the indoor unit is detected based on the temperature and pressure measured by the temperature and pressure sensors (Step 20). If an abnormality in the indoor unit is detected, the functions of the outdoor unit and multiple indoor units are restricted, rendering the air conditioner inoperable (Step 21). Next, a decision is made as to whether a pump-down operation is possible based on the detected abnormality (Step 22). If it is determined that a pump-down operation is not possible, the air conditioner is rendered inoperable (Step 23).

[0038] If it is determined in step 22 that pump-down operation is possible, the user can select backup operation via remote control or other means (step 24). If backup operation is selected, the abnormality detection state is disabled and the restrictions on the functions in step 21 are released (step 25). Next, the indoor control valve of the indoor unit where the abnormality was detected is fully opened and the outdoor control valve is fully closed, and the pump-down operation is performed (step 26).

[0039] After the pump-down operation is performed, the outdoor control valve is opened, and the indoor control valve of the indoor unit where the abnormality was detected is fully closed, and the refrigerant circuit of the indoor unit where the abnormality was detected is shut off (Step 27). Then, backup operation is performed with the normal indoor unit and the outdoor unit (Step 28).

[0040] [1] As described above, the air conditioner 10 comprises an outdoor unit 2, a plurality of indoor units 1,1', and a control device 9 that controls the outdoor unit 2 and the plurality of indoor units 1,1'. The indoor units 1,1' are equipped with indoor control valves 6 that adjust the flow rate of refrigerant flowing through the indoor units 1,1'. The control device 9 comprises an abnormality detection unit that detects abnormalities in at least the indoor units 1,1', a function restriction unit that restricts the functions of the outdoor unit 2 and / or the plurality of indoor units 1,1' when a predetermined abnormality is detected by the abnormality detection unit, and a restriction release unit that determines whether pump-down operation is possible and, if it is determined that pump-down operation is possible, releases the function restriction by the function restriction unit. The control device 9 performs control related to pump-down operation and then performs control to close the indoor control valve 6 of the indoor unit 1' in which the abnormality was detected.

[0041] With this configuration, even when an abnormality is detected in indoor unit 1', air conditioning operation is possible using the normal indoor unit 1 and outdoor unit 2, excluding the indoor unit 1' in which the abnormality was detected.

[0042] [2] In the air conditioner 10 described in [1] above, the abnormality detection unit may be configured to detect abnormalities in the indoor units 1,1' from the measured values ​​of temperature sensors and / or pressure sensors provided in the indoor units 1,1'.

[0043] [3] In the air conditioner 10 described in [1] or [2] above, it is preferable that the air conditioner 10 is equipped with a remote control 11 for operating indoor units 1,1', and the remote control 11 is equipped with a display unit that indicates at least that backup operation is in progress.

[0044] With this configuration, it is possible to inform occupants that backup operation is in progress.

[0045] It should be noted that the air conditioner is not limited to the configuration of the embodiment described above, nor is it limited to the effects and benefits described above. Furthermore, it goes without saying that the air conditioner can be modified in various ways without departing from the spirit of the present invention. For example, one or more of the various modifications described above may be arbitrarily selected and adopted in the configuration or method described in the embodiment described above. [Explanation of symbols]

[0046] 1, 1': Indoor unit, 2: Outdoor unit, 3: Compressor, 4: Outdoor heat exchanger, 5: Outdoor control valve, 6: Indoor control valve, 7: Indoor heat exchanger, 9: Control device, 10: Air conditioner, 11: Remote control, 12: Liquid connection pipe, 13: Gas connection pipe, 14: Outdoor fan, 15: Indoor fan

Claims

1. Outdoor unit and Multiple indoor units, The system comprises the outdoor unit and the control device for controlling the plurality of indoor units, The indoor unit is equipped with an indoor control valve that adjusts the flow rate of the refrigerant flowing through the indoor unit. The control device is At least an abnormality detection unit that detects an abnormality in the indoor unit, A function limiting unit that restricts the functions of the outdoor unit and the plurality of indoor units when a predetermined abnormality is detected by the abnormality detection unit, The system includes a function release unit that determines whether pump-down operation is possible and, if it determines that pump-down operation is possible, releases the function restriction imposed by the function limiting unit, The control device performs control related to pump-down operation, and then controls the indoor control valve of the indoor unit where an abnormality has been detected, in an air conditioner.

2. The air conditioner according to claim 1, wherein the abnormality detection unit detects an abnormality from the measured values ​​of a temperature sensor and / or pressure sensor provided in the indoor unit.

3. The indoor unit is equipped with a remote control for operating the indoor unit. The air conditioner according to claim 1 or 2, wherein the remote control includes a display unit that indicates at least that backup operation is in progress.

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