EP3869122B1

EP3869122B1 - Air conditioning apparatus

Info

Publication number: EP3869122B1
Application number: EP21153668.5A
Authority: EP
Inventors: Masanobu Hirota; Hideki Ito
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2020-02-20
Filing date: 2021-01-27
Publication date: 2022-11-23
Anticipated expiration: 2041-01-27
Also published as: JP7403079B2; JP2021131200A; JP2024009283A; EP3869122A1

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an air conditioning apparatus.

Description of the Related Art

An air conditioning apparatus has been conventionally known in which, in order to prevent a refrigerant from leaking indoors, a refrigerant pipe between an indoor unit and an outdoor unit is closed (see, for example, Japanese Patent Laid-Open No. 2000-28238 and Japanese Patent Laid-Open No. 2009-144991 ).
An air conditioning apparatus disclosed in Japanese Patent Laid-Open No. 2000-28238 includes a vibration sensing device that senses vibrations. When the vibration sensing device senses vibrations, a blocking mechanism closes a refrigerant pipe between an indoor unit and an outdoor unit in preparation for damage to the refrigerant pipe due to an earthquake.
An air conditioning apparatus disclosed in Japanese Patent Laid-Open No. 2009-144991 includes a vibration sensing device. When the vibration sensing device senses vibrations, a space between an indoor unit and an outdoor unit is closed, and a pump down operation is performed according to the seismic intensity to reduce the refrigerant amount on the indoor unit side.
Meanwhile, a refrigerant blocking valve is also closed by stop of the commercial power source, namely, a power failure. When the refrigerant blocking valve is closed, a worker who performs operation recovery or maintenance work after a power failure cannot determine whether the refrigerant blocking valve is closed by stop of the commercial power source or due to refrigerant leakage. Thus, in the conventional case, even though refrigerant leakage has occurred due to damage to the refrigerant pipe, the refrigerant blocking valve is opened after recovery of the commercial power source and a normal operation is executed; accordingly, the refrigerant may be supplied to the indoor space.
EP patent application 2 589 900 A forming the prior art from which the present invention starts, discloses an air conditioner which includes, inter alia, refrigerant leakage detecting means for detecting refrigerant leakage, air-blowing means, air-blowing control means for controlling air-blowing means, and wind-direction control means for controlling a wind direction of the air-blowing means. When the refrigerant leakage detecting means detects refrigerant leakage, the air-blowing control means and/or the wind-direction control means disperses a leaked refrigerant in a direction different from inhabitants and a heat source apparatus detected by the temperature distribution detecting means thereby enhancing the energy efficiency and safety when a flammable refrigerant is used as a refrigerant.
Moreover, EP patent application 3 534 087 A describes a refrigeration cycle device which is capable of performing pump down operation while suppressing degradation in performance. The refrigeration cycle apparatus includes an outdoor heat exchanger, a compressor including an inlet side and an outlet side, at least one indoor heat exchanger, a four-way valve, a check valve including an inlet side and an outlet side, a pipe serving as a first flow path connecting the outlet side of the check valve to the inlet side of the compressor, a first on-off valve, and a refrigerant leak detection device. The refrigeration cycle apparatus is configured such that, when a refrigerant leak is detected by the refrigerant leak detection device, pump down operation is performed as refrigerant transfer operation of transferring the refrigerant from the indoor heat exchanger to the outdoor heat exchanger.
Further, JP patent application 2016-191506 A discloses a refrigerant circuit in which an inflammable refrigerant is circulated. A compressor receives power supply from the outside for circulating the refrigerant in the refrigerant circuit. A refrigerant gas sensor and an outdoor side control device, and a refrigerant gas sensor and an indoor side control device receive power supply from the outside for detecting refrigerant leakage from the refrigerant circuit. A liquid crystal display device of a remote controller visibly displays transmission information that it is impossible to detect the refrigerant leakage when power supply is stopped.
The present invention has been made in view of the above-described circumstances and has an object to provide an air conditioning apparatus capable of safely implementing determination of a necessity of operation recovery or maintenance work in the case of recovery from a power failure.

SUMMARY OF THE INVENTION

In order to solve the problem, the present invention, as defined in claim 1, is an air conditioning apparatus including an outdoor unit comprising a compressor, an indoor unit, a refrigerant piping system passing through the indoor unit and connecting the outdoor unit and the indoor unit, a refrigerant detection unit that detects a refrigerant, the refrigerant detection unit being provided in the indoor unit or disposed at a position at which leakage of a refrigerant pipe passing through between the outdoor unit and the indoor unit can be detected, and a controller, the controller including a commercial power source supply detection unit configured to detect a presence or absence of supply of a commercial power source, input signal storage means, and refrigerant leakage detection means. The controller, when detecting recovery after stop of the commercial power source based on a detection result of the commercial power source supply detection unit, executes refrigerant leakage confirmation control in which a presence or absence of refrigerant leakage is confirmed, and when the refrigerant leakage confirmation control confirms that a refrigerant is not leaking, enables the air conditioning apparatus to resume a normal operation of the compressor.
According to this, after recovery from a power failure, before the normal operation of the air conditioning apparatus is resumed, the refrigerant leakage confirmation control is executed.

Advantageous Effect of Invention

According to the present invention, after recovery from a power failure, before the normal operation of the air conditioning apparatus is resumed, the refrigerant leakage confirmation control is executed, so that it can be determined whether refrigerant leakage has occurred due to damage to the refrigerant piping system before or after the power failure. Thus, determination of a necessity of operation recovery or maintenance work can be implemented safely. Furthermore, it can be avoided to resume the normal operation of the air conditioning apparatus in a state where refrigerant leakage has occurred due to damage to the refrigerant piping system after the power failure. Therefore, recovery of the normal operation of the air conditioning apparatus can be handled while the safety is secured.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a view illustrating a configuration of an air conditioning apparatus according to an embodiment;
Fig. 2 is a block diagram of a controller of the air conditioning apparatus according to the embodiment;
Fig. 3 is a flowchart illustrating a refrigerant leakage handling action for a power failure which is performed by the air conditioning apparatus according to the embodiment; and
Fig. 4 is a flowchart illustrating an operation return action during a power failure which is performed by the air conditioning apparatus according to the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention concerns an air conditioning apparatus including an outdoor unit including a compressor, an indoor unit, a refrigerant piping system passing through the indoor unit and connecting the outdoor unit and the indoor unit, a refrigerant detection unit that detects a refrigerant, the refrigerant detection unit being provided in the indoor unit or disposed at a position at which leakage of a refrigerant pipe passing through between the outdoor unit and the indoor unit can be detected, and a controller, the controller including a commercial power source supply detection unit configured to detect a presence or absence of supply of a commercial power source, input signal storage means, and refrigerant leakage detection means, wherein the controller, when detecting recovery after stop of the commercial power source based on a detection result of the commercial power source supply detection unit, executes refrigerant leakage confirmation control in which a presence or absence of refrigerant leakage is confirmed, and when the refrigerant leakage confirmation control confirms that a refrigerant is not leaking, enables the air conditioning apparatus to resume a normal operation of the compressor.
Thus, after recovery from a power failure, before the normal operation of the air conditioning apparatus is resumed, the refrigerant leakage confirmation control is executed, so that it can be confirmed whether refrigerant leakage has occurred due to damage to the refrigerant piping system before or after the power failure. This enables to handle recovery of the normal operation of the air conditioning apparatus while securing the safety.
As an option, provided is a refrigerant blocking valve that closes the refrigerant piping system during stop of the commercial power source.
This enables to confirm a presence or absence of damage to the refrigerant piping system before or after a power failure, so that it can be determined whether the refrigerant blocking valve is closed by the power failure or by damage to the refrigerant piping system.
As a further option, the indoor unit is provided with a blower fan and the refrigerant detection unit, and, in the refrigerant leakage confirmation control, the controller drives the blower fan and determines based on a detection result of the refrigerant detection unit whether refrigerant leakage has occurred.
Thus, in the refrigerant leakage confirmation control, the blower fan is driven, so that even when the refrigerant piping system is damaged before or after a power failure and the refrigerant leaks to the indoor space, the refrigerant remaining below the indoor space is stirred and can be detected by the refrigerant detection unit. This enables to confirm a presence or absence of damage to the pipe in a state where the refrigerant blocking valve is closed, so that the safety can be enhanced.
As an option, in the refrigerant leakage confirmation control, the controller opens the refrigerant blocking valve and determines based on a detection result of the refrigerant detection unit whether refrigerant leakage has occurred.
Thus, in the refrigerant leakage confirmation control, the refrigerant blocking valve is opened in a state where the compressor is not driven, so that refrigerant leakage easily occurs when the refrigerant piping system is damaged, thereby easily detecting the refrigerant leakage.
As a further option, the indoor unit includes a wind direction plate that adjusts a wind direction of air blown out from an air outlet, and, in the refrigerant leakage confirmation control, the controller moves the wind direction plate to a position at which the air outlet is closed, and the controller determines based on a detection result of the refrigerant detection unit whether refrigerant leakage has occurred.
Thus, in the refrigerant leakage confirmation control, the air outlet is closed by the wind direction plate, so that when the refrigerant piping system is damaged, the indoor unit can be filled with the refrigerant. This enables the refrigerant detection unit to quickly detect refrigerant leakage, and the safety can be enhanced.
As a yet further option, in the refrigerant leakage confirmation control, the controller drives the blower fan.
Thus, in the refrigerant leakage confirmation control, the blower fan is driven, so that even when the refrigerant piping system is damaged, the refrigerant concentration can be diluted, thereby enhancing the safety.
As another option, in the refrigerant leakage confirmation control, the controller drives the compressor to execute a heating operation, and the controller determines based on a detection result of the refrigerant detection unit whether refrigerant leakage has occurred.
Thus, in the refrigerant leakage confirmation control, executing the heating operation increases a refrigerant pressure of the refrigerant piping system of the indoor unit, so that even a slow leak of the refrigerant can be detected as refrigerant leakage.
As an option, provided is a watch that measures time, and, in the refrigerant leakage confirmation control, the controller calculates a power failure time of the commercial power source based on the time measured by the watch, and the controller, when the power failure time is equal to or more than a predetermined value, determines based on a detection result of the refrigerant detection unit whether refrigerant leakage has occurred.
Thus, when the power failure time is equal to or more than the predetermined time, the power failure is assumed to be due to a disaster such as an earthquake, and it is determined whether refrigerant leakage has occurred. When the power failure time is less than the predetermined time, the power failure is assumed to be not due to a disaster, and determination of whether refrigerant leakage has occurred can be omitted. Accordingly, while determination of refrigerant leakage which is less likely to have occurred is omitted and comfort of a user is maintained, operation recovery can be handled safely.
As an option, provided is a storage unit that stores information on a presence or absence of refrigerant leakage, wherein in the refrigerant leakage confirmation control, the controller refers to the storage unit, the controller, when information that refrigerant leakage has occurred is stored in the storage unit, notifies that a refrigerant is leaking, and the controller, when the information that refrigerant leakage has occurred is not stored in the storage unit, determines based on a detection result of the refrigerant detection unit whether refrigerant leakage has occurred.
Thus, the storage unit stores the information on a presence or absence of refrigerant leakage, so that even when whether refrigerant leakage has occurred is not determined after recovery from a power failure, it can be determined whether the refrigerant has leaked before the power failure, and the presence or absence of refrigerant leakage can be determined quickly.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[1. First Embodiment]

Fig. 1 is a view illustrating a configuration of an air conditioning apparatus 100 according to a first embodiment.
The air conditioning apparatus 100 includes an outdoor unit 1 and an indoor unit 2. The indoor unit 2 is connected to the outdoor unit 1 in parallel by a refrigerant pipe 17. The air conditioning apparatus 100 causes a refrigerant compressed in the outdoor unit 1 to flow between the outdoor unit 1 and the indoor unit 2 and air-conditions an inside of a room in which the indoor unit 2 is installed (conditioning target space). In the present embodiment, as an example of the refrigerant, a low flammable (A2L) refrigerant is used.
The outdoor unit 1 includes a compressor 3 that compresses the refrigerant, an outdoor heat exchanger 4, an outdoor fan 5, a switching valve 6, and an accumulator 10.
The compressor 3 draws the refrigerant from the entry side and compresses and discharges the refrigerant from the exit side.
The outdoor heat exchanger 4 exchanges heat between the refrigerant and outdoor air in the outdoor unit 1.
The outdoor fan 5 sends air to the outdoor heat exchanger 4.
The switching valve 6 is configured by, for example, a four-way valve. The switching valve 6 switches flows of the discharged refrigerant of the compressor 3 and a refrigerant returning to the compressor 3. The switching valve 6 switches a cooling operation mode and a heating operation mode of the air conditioning apparatus 100.
The accumulator 10 separates a liquid refrigerant and a gas refrigerant and stores the refrigerant.
The indoor unit 2 includes an indoor heat exchanger 7, an indoor fan 8, an expansion valve 9, and a refrigerant detection sensor 11.
The indoor heat exchanger 7 exchanges heat between a refrigerant supplied through the refrigerant pipe 17 from the outdoor unit 1 and indoor air. Note that the refrigerant pipe 17 also includes a pipe passing through the indoor unit 2. For example, the refrigerant pipe 17 includes a pipe passing through the indoor heat exchanger 7.
The indoor fan 8 sends air to the indoor heat exchanger 7. The indoor fan 8 corresponds to an example of a blower fan.
The expansion valve 9 decompresses and expands a high-pressure refrigerant. The expansion valve 9 is configured so that an opening degree thereof is adjustable. The opening degree of the expansion valve 9 is controlled by a controller 16. The expansion valve 9 may be a valve whose opening degree is adjustable and which can block the refrigerant.
The refrigerant detection sensor 11 is disposed in the vicinity of the indoor heat exchanger 7. The refrigerant detection sensor 11 detects a refrigerant concentration and inputs a detection signal to the controller 16.
Each of both sides of the indoor heat exchanger 7 of the indoor unit 2 is provided with a refrigerant blocking valve 12 that adjusts the refrigerant flow rate to the indoor unit 2. The refrigerant blocking valve 12 is configured by an opening and closing valve such as an electric valve or an electromagnetic valve. The refrigerant blocking valve 12 is switchable between an opened state in which the refrigerant flows and a closed state in which the refrigerant flow is blocked. The refrigerant blocking valve 12 is configured so that the opening and closing can be controlled by the controller 16. The refrigerant blocking valve 12 is configured to be closed when not supplied with power, namely, during a power failure. Note that the refrigerant blocking valve 12 may be a valve which can set a state between the opened state and the closed state or may be configured so that an opening degree of the refrigerant blocking valve 12 is controlled by the controller 16.
The air conditioning apparatus 100 includes the controller 16.
The controller 16 is electrically connected to an operation unit 13 configured by a remote control, an operation panel, or the like. The operation unit 13 is provided with alarm means 13a configured by a display unit, a sound source unit, or the like.
The controller 16 executes operation control of the compressor 3, control of the opening degree and opening and closing of the expansion valve 9, control of switching of a flow path of the switching valve 6, control of an operation and stop of the indoor fan 8, control of opening and closing of the refrigerant blocking valve 12, and the like.
The controller 16 operates the switching valve 6 and the expansion valve 9 to switch the cooling operation mode and the heating operation mode of the air conditioning apparatus 100. In the cooling operation mode of the air conditioning apparatus 100, the refrigerant flows through the compressor 3, the switching valve 6, the outdoor heat exchanger 4, the refrigerant blocking valve 12, the expansion valve 9, the indoor heat exchanger 7, the refrigerant blocking valve 12, the switching valve 6, and the accumulator 10 in this order, and returns to the compressor 3. In the heating operation mode of the air conditioning apparatus 100, the refrigerant flows through the compressor 3, the switching valve 6, the refrigerant blocking valve 12, the indoor heat exchanger 7, the expansion valve 9, the refrigerant blocking valve 12, the outdoor heat exchanger 4, the switching valve 6, and the accumulator 10 in this order, and returns to the compressor 3.
Furthermore, the controller 16, in accordance with a target temperature set by an operation on the operation unit 13, executes control of an operation frequency and an operation and/or stop of the compressor 3, and control of the outdoor fan 5 and the indoor fan 8 to air-condition the conditioning target space in accordance with the target temperature.
Fig. 2 is a block diagram of the controller 16 of the air conditioning apparatus 100 according to the embodiment.
The controller 16 includes processing means, storage means, and the like and realizes various functions of the air conditioning apparatus 100.
The controller 16 is electrically connected to the refrigerant detection sensor 11, a commercial power source 14, and a watch 18 as elements for inputting a detection signal to the controller 16.
The refrigerant detection sensor 11 detects the refrigerant to detect the refrigerant amount, namely, a concentration Mref of the refrigerant. When the concentration Mref of the refrigerant is equal to or more than a predetermined value, the controller 16 determines that refrigerant leakage has occurred. The refrigerant detection sensor 11 corresponds to an example of a refrigerant detection unit.
The commercial power source 14 supplies commercial power to the air conditioning apparatus 100. Although in the present embodiment, the commercial power source 14 is connected to the outdoor unit 1, the commercial power source 14 may be connected to the indoor unit 2 instead of the outdoor unit 1. Furthermore, the commercial power source 14 may be configured to be connected to both the outdoor unit 1 and the indoor unit 2.
The watch 18 measures time.
The controller 16 is electrically connected to the compressor 3, the switching valve 6, the refrigerant blocking valve 12, a wind direction plate 15, the indoor fan 8, and the alarm means 13a in a controllable manner as elements to which the controller 16 outputs a control signal.
The wind direction plate 15 is supported so as to be movable between a position at which an air outlet of the indoor unit 2 is closed and a position at which the air outlet of the indoor unit 2 is opened. The controller 16 controls the position of the wind direction plate 15 to adjust a wind direction of air blown out from the air outlet of the indoor unit 2.
The controller 16 includes a commercial power source supply detection unit 16a, input signal storage means 16b, and refrigerant leakage detection means 16c.
The commercial power source supply detection unit 16a detects supply of the commercial power source 14. Thus, when the supply of the commercial power source 14 is brought into a detected state from an undetected state, the controller 16 determines that the commercial power source 14 is recovered (power recovery). Furthermore, when the supply of the commercial power source 14 becomes undetected from the detected state, the controller 16 determines that the commercial power source 14 is stopped (power failure). Note that when the commercial power source is stopped, the controller 16 is configured to be operable by using a battery, which is not illustrated.
The input signal storage means 16b, when refrigerant leakage occurs, records (stores) the occurrence of the refrigerant leakage. The input signal storage means 16b corresponds to an example of a storage unit that stores information on a presence or absence of refrigerant leakage.
The refrigerant leakage detection means 16c determines whether refrigerant leakage has occurred, based on whether the concentration Mref detected by the refrigerant detection sensor 11 is larger than a threshold LFL. Here, when a low flammable or flammable refrigerant leaks, suppression of the amount of refrigerant leakage is required so that a refrigerant concentration of the conditioning target space of the indoor unit 2 does not reach a lower flammability limit (LFL). In particular, it is desirable to suppress the amount of refrigerant leakage from the indoor unit 2 installed in the conditioning target space or in the vicinity thereof. When the detected concentration Mref is larger than the threshold LFL, the refrigerant leakage detection means 16c determines that refrigerant leakage has occurred. Furthermore, when the detected concentration Mref is not larger than the threshold LFL, the refrigerant leakage detection means 16c determines that refrigerant leakage has not occurred.
Fig. 3 is a flowchart illustrating a refrigerant leakage handling action for a power failure which is performed by the air conditioning apparatus 100 according to the embodiment. Fig. 4 is a flowchart illustrating an operation return action during a power failure. The actions of Figs. 3 and 4 are executed by the controller 16 controlling each unit of the air conditioning apparatus 100.
As illustrated in Fig. 3, upon starting processing of the refrigerant leakage handling action for a power failure, the controller 16 determines whether refrigerant leakage has occurred (step ST11).
When determining that refrigerant leakage has not occurred, namely, when refrigerant leakage is not detected (NO in step ST11), the controller 16 continues the processing of step ST11.
When determining that refrigerant leakage has occurred, namely, when refrigerant leakage is detected (YES in step ST11), the controller 16 records (stores) the occurrence of the refrigerant leakage (step ST12). Thus, whether there has been refrigerant leakage before the power failure can be referred to after recovery from the power failure.
The controller 16 closes the refrigerant blocking valve 12 (step ST13). This blocks the refrigerant flow in the refrigerant pipe 17.
The controller 16 activates the alarm means 13a (step ST14). This makes it easier for a worker to recognize that refrigerant leakage has occurred and the refrigerant blocking valve 12 is closed. The worker, by recognizing the occurrence of the refrigerant leakage, can perform maintenance work such as exchange or repair of a refrigerant piping system such as the refrigerant pipe 17.
Then, the controller 16 ends the processing of the refrigerant leakage handling action for a power failure.
Note that the order of step ST13 and step ST14 may be reversed or may be executed simultaneously. Furthermore, the processing of the refrigerant leakage handling action for a power failure which is illustrated in Fig. 3 ends halfway, during the power failure.
As illustrated in Fig. 4, upon starting the operation return action during a power failure, the controller 16 determines whether the commercial power source is stopped (step ST21).
When determining that the commercial power source is not stopped (NO in step ST21), the controller 16 continues the processing of step ST21.
When determining that the commercial power source is stopped (YES in step ST21), the controller 16 closes the refrigerant blocking valve 12 (step ST22). This blocks the refrigerant flow.
The controller 16 acquires a time at which the power failure occurred (time of power failure) (step ST23).
The controller 16 determines whether the commercial power source has recovered (step ST24).
When determining that the commercial power source has not recovered (NO in step ST24), the controller 16 continues the processing of step ST24.
When determining that the commercial power source has recovered (YES in step ST24), the controller 16 acquires a time at which the commercial power source recovered (time of power recovery) (step ST25).
The controller 16 determines whether there is a record of leakage occurrence (leakage history) (step ST26). Namely, in step ST26, it is determined whether refrigerant leakage has occurred before the power failure.
When determining that there is a record of leakage occurrence (YES in step ST26), the controller 16 activates the alarm means 13a (step ST27).
Then, the controller 16 ends the processing of the operation return action during a power failure.
When determining that there is no record of leakage occurrence (NO in step ST26), the controller 16 determines whether a power failure time (a difference between the time of power recovery and the time of power failure) is shorter than a predetermined time (step ST28). This determines whether the power failure is a short-term power failure such as an instantaneous interruption caused by a lightning strike or a long-term power failure caused by an earthquake or the like. The predetermined time is a time as a threshold for determining either one of the short-term power failure and the long-term power failure. In the present embodiment, as an example, ten minutes is set.
When determining that the power failure time is not shorter than the predetermined time (YES in step ST28), the controller 16 activates the indoor fan 8 (step ST31). Here, in the case of the long-term power failure, the power failure may have been caused by an earthquake. When the power failure is caused by an earthquake, for example, a connection joint portion between the indoor unit 2 and the refrigerant pipe 17 may be damaged by earthquake shaking, and thus it is possible that the refrigerant pipe 17 is damaged. Thus, in step ST31, the indoor fan 8 is activated so that the refrigerant can be stirred in preparation for a case where the refrigerant is leaking from the refrigerant piping system such as the refrigerant pipe 17, thereby allowing the refrigerant detection sensor 11 to easily detect the refrigerant. Furthermore, the refrigerant which has leaked and may remain indoors is easily diluted. Furthermore, even if the refrigerant remains on the indoor floor, the refrigerant remaining on the indoor floor is stirred, so that the refrigerant easily flows to the indoor unit 2 and can be detected by the refrigerant detection sensor 11.
The controller 16 determines whether refrigerant leakage has occurred (step ST32). Step ST32 is the same as step ST11. In step ST32, it is determined whether refrigerant leakage has occurred, based on a detection result of the refrigerant detection sensor 11 in a state where the indoor fan 8 is activated. Here, when the indoor fan 8 is activated, even if the refrigerant remains on the indoor floor, the refrigerant remaining on the indoor floor easily flows to the indoor unit 2. Accordingly, the activation of the indoor fan 8 makes it easier for the refrigerant detection sensor 11 to detect the refrigerant remaining on the indoor floor.
When determining that refrigerant leakage has occurred (YES in step ST32), the controller 16 activates the alarm means 13a (step ST27) and ends the processing of the operation return action during a power failure.
When determining that refrigerant leakage has not occurred (NO in step ST32), the controller 16 opens the refrigerant blocking valve 12 (step ST33). Thus, the refrigerant easily flows through the indoor unit 2, so that when the indoor unit 2 is damaged, the refrigerant easily leaks. Namely, the controller 16 can easily detect the refrigerant leakage.
The controller 16 moves the wind direction plate 15 of the indoor unit 2 to the position at which the air outlet is closed (step ST34). Thus, when the refrigerant is leaking into the indoor unit 2, the refrigerant concentration in the indoor unit 2 is easily increased. Namely, when refrigerant leakage occurs, the controller 16 can easily detect the refrigerant leakage.
The controller 16 determines whether refrigerant leakage has occurred (step ST35). Step ST33 is the same as step ST11.
When determining that refrigerant leakage has occurred (YES in step ST35), the controller 16 activates the alarm means 13a (step ST27) and ends the processing of the operation return action during a power failure.
When determining that refrigerant leakage has not occurred (NO in step ST35), the controller 16 operates the compressor 3 in the heating mode (step ST36). Thus, the refrigerant amount on the indoor unit 2 side is increased compared with the outdoor unit 1 to increase a refrigerant pressure of the refrigerant piping system on the indoor unit 2 side, so that a slow leak of the refrigerant can be detected.
The controller 16 determines whether refrigerant leakage has occurred (step ST37). Step ST37 is the same as step ST11.
When determining that refrigerant leakage has occurred (YES in step ST37), the controller 16 activates the alarm means 13a (step ST27) and ends the processing of the operation return action during a power failure.
When determining that refrigerant leakage has not occurred (NO in step ST37), the controller 16 enables to resume a normal operation of the compressor 3 (step ST38). Thus, normal operations of the heating mode and the cooling mode of the air conditioning apparatus 100 can be executed by, for example, an operation of the operation unit 13.
Then, the controller 16 ends the processing of the operation return action during a power failure.
Generally, in the air conditioning apparatus, the refrigerant blocking valve is also closed by stop of the commercial power source. Thus, when the refrigerant blocking valve is closed, the worker cannot determine whether the refrigerant blocking valve is closed by stop of the commercial power source or due to refrigerant leakage. Thus, in the conventional case, even though refrigerant leakage has occurred, the refrigerant blocking valve is opened after recovery of the commercial power source and a normal operation is executed; accordingly, the refrigerant may be supplied to the indoor space. In particular, when a power failure occurs due to an earthquake, damage to the refrigerant piping system may also be facilitated by earthquake shaking, and a large amount of refrigerant may leak to the indoor space.
In contrast, the air conditioning apparatus 100 of the present embodiment executes the refrigerant leakage handling action for a power failure and the operation return action during a power failure.
In the refrigerant leakage handling action for a power failure, when refrigerant leakage occurs, the occurrence of the refrigerant leakage is recorded. Thus, even when a power failure occurs, whether refrigerant leakage has occurred before the power failure can be referred to after the power failure, namely, after the power recovery.
In the operation return action during a power failure, the record of leakage occurrence is referred to by step ST26. Although when a power failure occurs, the refrigerant blocking valve 12 is closed regardless of a presence or absence of refrigerant leakage, referring to the record of leakage occurrence during the power recovery enables to immediately determine whether the refrigerant blocking valve 12 is closed by refrigerant leakage.
Furthermore, even when the refrigerant blocking valve 12 is closed by a power failure, after the power failure, the refrigerant piping system may be damaged by, for example, earthquake shaking. Namely, after the power failure, the refrigerant piping system such as the refrigerant pipe 17 at an indoor space disposition region portion connecting the outdoor unit 1 and the indoor unit 2, the refrigerant pipe 17 at a portion within the indoor unit 2, the indoor heat exchanger 7 (including a brazed portion), and the expansion valve (valve component) 9 may be damaged. Thus, in the operation return action during a power failure, even when refrigerant leakage does not occur before the power failure, the control in steps ST31 to ST32, steps ST33 to ST35, and steps ST36 to ST37 to determine whether refrigerant leakage has occurred is executed. By these, even when refrigerant leakage occurs due to damage to the refrigerant piping system after the power failure, the refrigerant leakage can be detected, and the normal operation of the air conditioning apparatus 100 can be resumed safely.
However, when the power failure time is short, it is highly possible that the power failure is caused by other than an earthquake, for example, by an instantaneous interruption due to a lightning strike, and the refrigerant piping system is unlikely to be damaged. Thus, in the operation return action during a power failure, as illustrated in step ST28, when the power failure time is shorter than the predetermined time, execution of the control of the refrigerant leakage determination is omitted, and the normal operation of the compressor 3 is resumed. Accordingly, it becomes easier to effectively achieve a safe operation return of the air conditioning apparatus 100.
In the present embodiment, as an example of refrigerant leakage confirmation control, the controller 16 executes the control of the processing of step ST26 and steps ST31 to ST37.
Here, although in the above-described operation return action during a power failure, the configuration has been described in which step ST34 is executed, step ST34 may be omitted. Namely, the controller 16 may be configured to execute step ST35 after executing step ST33.
As described above, the air conditioning apparatus 100 of the present embodiment is the air conditioning apparatus 100 including the outdoor unit 1 including the compressor 3, the indoor unit 2, the refrigerant piping system passing through the indoor unit 2 and connecting the outdoor unit 1 and the indoor unit 2, the commercial power source supply detection unit 16a that detects a presence or absence of supply of the commercial power source 14, the refrigerant detection sensor 11 that detects the refrigerant, and the controller 16, wherein the controller 16, when detecting recovery after stop of the commercial power source 14 based on a detection result of the commercial power source supply detection unit 16a, executes the refrigerant leakage confirmation control in which a presence or absence of refrigerant leakage is confirmed, and the controller 16, when the refrigerant leakage confirmation control confirms that the refrigerant is not leaking, enables to resume the normal operation of the air conditioning apparatus 100.
Thus, after recovery from a power failure, before the normal operation of the air conditioning apparatus 100 is resumed, the refrigerant leakage confirmation control is executed, so that it can be confirmed whether refrigerant leakage has occurred due to damage to the refrigerant piping system before or after the power failure. This enables to handle recovery of the normal operation of the air conditioning apparatus 100 while securing the safety.
In the present embodiment, provided is the refrigerant blocking valve 12 that closes the refrigerant piping system during stop of the commercial power source 14.
This enables to confirm a presence or absence of damage to the refrigerant piping system before or after a power failure, so that it can be determined whether the refrigerant blocking valve 12 is closed by the power failure or by damage to the refrigerant piping system.
In the present embodiment, the indoor unit 2 is provided with the blower fan 8 and the refrigerant detection sensor 11, and, in the refrigerant leakage confirmation control, the controller 16 drives the indoor fan 8 and determines based on a detection result of the refrigerant detection sensor 11 whether refrigerant leakage has occurred.
Thus, in the refrigerant leakage confirmation control, the indoor fan 8 is driven, so that even when the refrigerant piping system is damaged before or after a power failure and the refrigerant leaks to the indoor space, the refrigerant remaining below the indoor space is stirred and can be detected by the refrigerant detection sensor 11. This enables to confirm a presence or absence of damage to the pipe in a state where the refrigerant blocking valve 12 is closed, so that the safety can be enhanced.
In the present embodiment, in the refrigerant leakage confirmation control, the controller 16 opens the refrigerant blocking valve 12 and determines based on a detection result of the refrigerant detection sensor 11 whether refrigerant leakage has occurred.
Thus, in the refrigerant leakage confirmation control, the refrigerant blocking valve 12 is opened in a state where the compressor 3 is not driven, so that refrigerant leakage easily occurs when the refrigerant piping system is damaged, thereby easily detecting the refrigerant leakage.
In the present embodiment, the indoor unit 2 includes the wind direction plate 15 that adjusts the wind direction of the air blown out from the air outlet, and, in the refrigerant leakage confirmation control, the controller 16 moves the wind direction plate 15 to the position at which the air outlet is closed, and determines based on a detection result of the refrigerant detection sensor 11 whether refrigerant leakage has occurred.
Thus, in the refrigerant leakage confirmation control, the air outlet is closed by the wind direction plate 15, so that when the refrigerant piping system is damaged, the indoor unit 2 can be filled with the refrigerant. This enables the refrigerant detection sensor 11 to quickly detect refrigerant leakage, and the safety can be enhanced.
In the present embodiment, in the refrigerant leakage confirmation control, the controller 16 drives the indoor fan 8.
Thus, in the refrigerant leakage confirmation control, the indoor fan 8 is driven, so that even when the refrigerant piping system is damaged, the refrigerant concentration can be diluted, thereby enhancing the safety.
In the present embodiment, in the refrigerant leakage confirmation control, the controller 16 drives the compressor 3 to execute the heating operation and determines based on a detection result of the refrigerant detection sensor 11 whether refrigerant leakage has occurred.
Thus, in the refrigerant leakage confirmation control, executing the heating operation increases the refrigerant pressure of the refrigerant piping system of the indoor unit 2, so that even a slow leak of the refrigerant can be detected as refrigerant leakage.
In the present embodiment, provided is the watch 18 that measures time, and, in the refrigerant leakage confirmation control, the controller 16 calculates the power failure time of the commercial power source 14 based on the time measured by the watch 18 and, when the power failure time is equal to or more than the predetermined value, determines based on a detection result of the refrigerant detection sensor 11 whether refrigerant leakage has occurred.
Thus, when the power failure time is equal to or more than the predetermined time, the power failure is assumed to be due to a disaster such as an earthquake, and it is determined whether refrigerant leakage has occurred. When the power failure time is less than the predetermined time, the power failure is assumed to be not due to a disaster, and determination of whether refrigerant leakage has occurred can be omitted. Accordingly, while determination of refrigerant leakage which is less likely to have occurred is omitted and comfort of a user is maintained, operation recovery can be handled safely.
In the present embodiment, provided is the input signal storage means 16b that stores the information on a presence or absence of refrigerant leakage, and, in the refrigerant leakage confirmation control, the controller 16 refers to the input signal storage means 16b, the controller 16, when information that refrigerant leakage has occurred is stored in the input signal storage means 16b, notifies that the refrigerant is leaking, and the controller 16, when the information that refrigerant leakage has occurred is not stored in the input signal storage means 16b, determines based on a detection result of the refrigerant detection sensor 11 whether refrigerant leakage has occurred.
Thus, the input signal storage means 16b stores the information on a presence or absence of refrigerant leakage, so that even when whether refrigerant leakage has occurred is not determined after recovery from a power failure, it can be determined whether the refrigerant has leaked before the power failure, and the presence or absence of refrigerant leakage can be determined quickly.

[2. Other Embodiments]

Although the present invention has been described based on the embodiment, the present invention is not limited to the present embodiment. Since the present embodiment is given to merely exemplify an embodiment of the present invention, any changes and applications are possible without departing from the gist of the present invention.
In the embodiment, the configuration has been described in which the refrigerant detection sensor 11 is provided in the indoor unit 2. However, the refrigerant detection sensor 11 may be disposed at a position at which leakage of the refrigerant pipe 17 passing through between the outdoor unit 1 and the indoor unit 2 can be detected. For example, the refrigerant detection sensor 11 may be provided outside a housing of the indoor unit 2. Furthermore, the refrigerant detection sensor 11 may be provided above the ceiling outside the indoor unit 2 or on the indoor wall within 30 cm from the floor.
Although in the embodiment, an example has been described in which the air conditioning apparatus 100 has a configuration of a room air conditioner including one outdoor unit 1 and one indoor unit 2, the present invention is not limited to this. For example, the present invention may be applied to a configuration of a packaged air conditioner including one outdoor unit 1 and a plurality of the indoor units 2, a packaged air conditioner in which a plurality of the indoor units 2 is connected to a plurality of the outdoor units 1, or a multi-air-conditioner for building. The invention is defined in the appended claims.

[Industrial Applicability]

As described above, the air conditioning apparatus according to the present invention can be preferably used as an air conditioning apparatus capable of safely implementing determination of a necessity of operation recovery or maintenance work in the case of recovery from a power failure.

Reference Signs List

1: outdoor unit
2: indoor unit
3: compressor
8: indoor fan (blower fan)
11: refrigerant detection sensor (refrigerant detection unit)
12: refrigerant blocking valve
14: commercial power source
15: wind direction plate
16: controller
16a: commercial power source supply detection unit
16b: input signal storage means (storage unit)
17: refrigerant pipe
18: watch
100: air conditioning apparatus

Claims

An air conditioning apparatus (100) comprising:
an outdoor unit (1) comprising a compressor (3);

an indoor unit (2);

a refrigerant piping system passing through the indoor unit (2) and connecting the outdoor unit (1) and the indoor unit (2);

a refrigerant detection unit (11) configured to detect a refrigerant, the refrigerant detection unit (11) being provided in the indoor unit (2) or disposed at a position at which leakage of a refrigerant pipe (17) passing through between the outdoor unit (1) and the indoor unit (2) can be detected; and

a controller (16), the controller (16) including a commercial power source supply detection unit (16a) configured to detect a presence or absence of supply of a commercial power source (14), input signal storage means (16b), and refrigerant leakage detection means (16c),

characterized in that the controller (16) is configured to, when detecting recovery after stop of the commercial power source (14) based on a detection result of the commercial power source supply detection unit (16a), execute refrigerant leakage confirmation control in which a presence or absence of refrigerant leakage is confirmed, and when the refrigerant leakage confirmation control confirms that a refrigerant is not leaking, enable the air conditioning apparatus (100) to resume a normal operation of the compressor (3).
The air conditioning apparatus (100) according to claim 1, comprising a refrigerant blocking valve (12) configured to close the refrigerant piping system during stop of the commercial power source (14).
The air conditioning apparatus (100) according to claim 2,
wherein the indoor unit (2) is provided with a blower fan (8) and the refrigerant detection unit (11), and

in the refrigerant leakage confirmation control, the controller (16) is configured to drive the blowerfan (8) and determine based on a detection result of the refrigerant detection unit (11) whether refrigerant leakage has occurred.
The air conditioning apparatus (100) according to claim 2,
wherein in the refrigerant leakage confirmation control, the controller (16) is configured to open the refrigerant blocking valve (12) and determine based on a detection result of the refrigerant detection unit (11) whether refrigerant leakage has occurred.
The air conditioning apparatus (100) according to claim 4,
wherein the indoor unit (2) comprises a wind direction plate (15) configured to adjust a wind direction of air blown out from an air outlet, and

in the refrigerant leakage confirmation control, the controller (16) is configured to move the wind direction plate (15) to a position at which the air outlet is closed, and determine based on a detection result of the refrigerant detection unit (11) whether refrigerant leakage has occurred.
The air conditioning apparatus (100) according to claim 5,
wherein in the refrigerant leakage confirmation control, the controller (16) is configured to drive a blower fan (8).
The air conditioning apparatus (100) according to claim 1,
wherein in the refrigerant leakage confirmation control, the controller (16) is configured to drive the compressor (3) to execute a heating operation, and determine based on a detection result of the refrigerant detection unit (11) whether refrigerant leakage has occurred.
The air conditioning apparatus (100) according to claim 1, comprising a watch (18) configured to measure time,
wherein in the refrigerant leakage confirmation control, the controller (16) is configured to calculate a power failure time of the commercial power source (14) based on the time measured by the watch (18), and when the power failure time is equal to or more than a predetermined value, determine based on a detection result of the refrigerant detection unit (11) whether refrigerant leakage has occurred.
The air conditioning apparatus (100) according to claim 1, comprising a storage unit (16b) configured to store information on a presence or absence of refrigerant leakage,
wherein in the refrigerant leakage confirmation control, the controller (16) is configured to refer to the storage unit (16b), when information that refrigerant leakage has occurred is stored in the storage unit (16b), notify that a refrigerant is leaking, and when the information that refrigerant leakage has occurred is not stored in the storage unit (16b), determine based on a detection result of the refrigerant detection unit (11) whether refrigerant leakage has occurred.