Patent Description:
<CIT> discloses an indoor unit that maximizes a detectable time when a detection sensor is activated by a power storage unit for use as an emergency power source during power failure. This indoor unit includes a casing, a heat exchanger through which a flammable refrigerant flows, the power storage unit for use as the emergency power source when power supply from a commercial power source is not available, the detection sensor that detects leakage of the refrigerant, and a controller that controls energization from the commercial power source or the power storage unit to the detection sensor. The controller controls the energization from the power storage unit to the detection sensor to intermittently activate the detection sensor.

<CIT> describes an air conditioner that includes temperature distribution detecting means for detecting a temperature distribution in a room, refrigerant leakage detecting means for detecting refrigerant leakage, air-blowing means, air-blowing control means for controlling the 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 any 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.

The present invention provides an air conditioning system capable of efficiently driving a device for a countermeasure against refrigerant leakage by use of power of a power storage unit, when power supply from a commercial power source is not available.

An air conditioning system <NUM> in the present invention includes a refrigeration cycle to circulate a slightly flammable refrigerant or a flammable refrigerant, an indoor unit including a heat exchanger connected to the refrigeration cycle, the indoor unit being installed in an indoor space, a refrigerant sensor that detects the refrigerant leaking from the indoor unit, a ventilation device that ventilates the indoor space, a power storage unit that is charged by a commercial power source, and a controller, wherein the refrigerant sensor and the ventilation device are operated by the commercial power source. The controller operates the ventilation device with power of the power storage unit, in a case where the controller detects that a power supply from the commercial power source is stopped, regardless of whether or not the refrigerant leaking is detected by the refrigerant sensor. Further, when the power supply from the commercial power source does not recover from the power failure after operating the ventilation device, the controller operates the refrigerant sensor with power of the power storage unit and determines whether or not the refrigerant sensor normally functions. In a case where the controller determines that the refrigerant sensor normally functions, the controller executes a first ventilation operation to operate the ventilation device with power of the power storage unit for a predetermined ventilation time that is calculated based on a remaining amount of power in the power storage unit, a volume in the indoor space, and a ventilation amount of the ventilation device per unit time.

According to the present invention, a device for a countermeasure against refrigerant leakage can be efficiently driven by using power of a power storage unit, when power supply from a commercial power source is not available.

(Fundamental Knowledge of present invention) At the time when the inventors came up with the present invention, there was a technology of maximizing a detectable time, when activating a detection sensor with a power storage unit for use as an emergency power source, for a countermeasure against refrigerant leakage during power failure in an indoor unit of an air conditioning system <NUM>.

This indoor unit includes a heat exchanger through which a flammable refrigerant flows, a battery that is the power storage unit for use as the emergency power source when power supply from a commercial power source is not available, a detection sensor that detects leakage of the flammable refrigerant, and a control device corresponding to a controller that controls energization from the commercial power source or the battery to the detection sensor. The control device controls the energization from the battery to the detection sensor to intermittently activate the detection sensor.

Additionally, in a case where the commercial power source is stopped (in a state of so-called power failure) due to earthquake or the like, a refrigerant might leak from a refrigerant pipe due to damages on the pipe. Therefore, in the case where the commercial power source is stopped, it is highly necessary to drive a refrigerant sensor and a ventilation device with an external power source. However, power consumption of the ventilation device is larger than that of the refrigerant sensor, and hence these devices for the countermeasure against the refrigerant leakage could not be operated with the external power source for a long time.

To solve the problem, the present invention provides an air conditioning system <NUM> capable of efficiently driving a ventilation device with power of a power storage unit, when power supply from a commercial power source is stopped.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, an unnecessarily detailed description may not be made. For example, a detailed description of already well known matter or a redundant description of about the same configuration may not be made. This avoids making the following description unnecessarily redundant, and facilitates understanding of a person skilled in the art.

Note that the accompanying drawings and the following description are provided for the person skilled in the art to sufficiently understand the present invention. The scope of the invention is defined in the claims.

Hereinafter, Embodiment <NUM> will be described with reference to <FIG>.

<FIG> is a block diagram showing a configuration of an air conditioning system <NUM> according to the present embodiment.

<FIG> is a diagram showing a configuration of the air conditioning system <NUM> in an indoor space <NUM>.

The air conditioning system <NUM> includes a refrigeration cycle formed by an indoor heat exchanger <NUM> and a decompression device that are housed in an indoor unit <NUM>, and a compressor, a decompression device, an outdoor heat exchanger and others that are housed in an outdoor unit <NUM>. Furthermore, the air conditioning system <NUM> performs air conditioning of the indoor space <NUM> by circulating a refrigerant in this refrigeration cycle, the indoor space being a space to be conditioned that is provided with the indoor unit <NUM>.

In the present embodiment, R32 that is a slightly flammable refrigerant is for use as the refrigerant of the air conditioning system <NUM>. Note that the refrigerant is not limited to this example, and various alternative chlorofluorocarbons such as hydrocarbons and ammonias may be used in the refrigerant of the air conditioning system <NUM>.

As shown in <FIG> and <FIG>, the air conditioning system <NUM> of the present embodiment includes the outdoor unit <NUM> and the indoor unit <NUM>, and the system is configured by connecting the outdoor unit <NUM> and the indoor unit <NUM> by refrigerant pipes <NUM> and <NUM>.

The outdoor unit <NUM> includes the compressor, a heat source side heat exchanger, an expansion valve, and a switching valve that switches a heating operation and a cooling operation. In addition, the outdoor unit <NUM> may include an accumulator, a pressure sensor or the like.

The indoor unit <NUM> is installed in the indoor space <NUM>, and performs the air conditioning of the indoor space <NUM>. That is, the indoor space <NUM> is the space to be conditioned in the indoor unit <NUM>.

The air conditioning system <NUM> performs the cooling operation or the heating operation to the indoor space <NUM>. For this purpose, the refrigerant flows through two refrigerant pipes <NUM> and <NUM> between the outdoor unit <NUM> and the indoor unit <NUM>. A high pressure gas refrigerant flows through one of the refrigerant pipes <NUM> and <NUM>, and a low pressure gas or liquid refrigerant flows through the other refrigerant pipe. The refrigerant pipes <NUM> and <NUM> branch from each other and are connected to a refrigerant circuit <NUM> included in the indoor unit <NUM>. A direction in which the refrigerant flows through the refrigerant pipes <NUM> and <NUM> during the cooling operation is reverse to that during the heating operation in the air conditioning system <NUM>.

The air conditioning system <NUM> includes a refrigerant leakage detection sensor <NUM> corresponding to a detection sensor that detects the refrigerant. The refrigerant leakage detection sensor <NUM> detects the refrigerant leaking from the refrigerant circuit <NUM>, a connected part of the refrigerant circuit <NUM> to the refrigerant pipe <NUM> or <NUM>, and the like.

In the present embodiment, the refrigerant leakage detection sensor <NUM> is installed in the indoor space <NUM>. In a case where the refrigerant for use in the air conditioning system <NUM> is a gas with a specific gravity larger than that of air, it is desirable that the refrigerant leakage detection sensor <NUM> is installed in a lower part of the indoor space <NUM>.

Alternatively, the refrigerant leakage detection sensor <NUM> may be disposed in a housing of the indoor unit <NUM>.

The air conditioning system <NUM> includes a ventilation device <NUM>. In the ventilation device <NUM>, a blower including any type of fan such as an axial fan or a centrifugal fan is used, and the device is a so-called mechanical ventilation device that ventilates, with the fan, the indoor space where the device is installed.

The ventilation device <NUM> of the present embodiment discharges the refrigerant that leaks into the indoor space <NUM> to outside of the indoor space <NUM>.

The ventilation device <NUM> is connected to a commercial alternating current power source <NUM> as a commercial power source via a feed line <NUM>. The commercial AC power source <NUM> is a power source connected to the ventilation device <NUM> in the indoor space <NUM>. Consequently, power of AC 200V is supplied from the commercial AC power source <NUM> to the ventilation device <NUM>. The ventilation device <NUM> can be driven with this power.

The air conditioning system <NUM> of the present embodiment is provided with an external power source kit <NUM> that is disposed in the indoor space.

The external power source kit <NUM> includes a power storage unit <NUM> that stores a supplied current. The external power source kit <NUM> discharges and supplies power stored in each part of the air conditioning system <NUM>, when the supply of the current is stopped.

The air conditioning system <NUM> includes an alarm device <NUM>. The alarm device <NUM> issues an alarm to the outside, and notifies a management center of various types of information depending on a state of the air conditioning system <NUM> in the present embodiment. For example, in a case where driving of the refrigerant leakage detection sensor <NUM> or the ventilation device <NUM> cannot be confirmed, the alarm device <NUM> notifies the management center that it is necessary to repair these units.

Note that the alarm device <NUM> may issue an alarm not only to the outside but also to those who are in the indoor space <NUM>. Also, in this case, the alarm device may be disposed integrally in a remote control device or the like that is capable of operating the air conditioning system <NUM>.

The air conditioning system <NUM> includes a control device <NUM>. The control device <NUM> controls an operation of the air conditioning system <NUM>. The control device <NUM> executes, for example, control of operation start and operation stop of the outdoor unit <NUM>, control of operations of the compressor and the switching valve included in the outdoor unit <NUM>, and detection of an operating state of each of the outdoor unit <NUM> and the indoor unit <NUM>.

As shown in <FIG>, the indoor unit <NUM> includes an indoor heat exchanger <NUM> that forms the refrigerant circuit <NUM>, and an indoor fan <NUM> that blows air to the indoor heat exchanger <NUM>.

The indoor unit <NUM> includes the refrigerant circuit <NUM> in which the refrigerant supplied from the outdoor unit <NUM> circulates. The refrigerant circuit <NUM> includes, for example, the indoor heat exchanger <NUM> that is a user side heat exchanger, and another pipe.

The indoor unit <NUM> is connected to the commercial AC power source <NUM> as the commercial power source via a feed line <NUM>. The commercial AC power source <NUM> is a power source connected to the indoor unit <NUM> in the indoor space <NUM>. The commercial AC power source <NUM> is a common power source that is also connected to the ventilation device <NUM> as described above. Consequently, the power of AC 200V is supplied from the commercial AC power source <NUM> to the indoor unit <NUM>.

Note that in the present embodiment, an example where the commercial AC power source <NUM> of AC 200V is connected to the indoor unit <NUM> is described, but the present invention is not limited to this example. For example, another power source of AC 100V or the like may be connected to the indoor unit <NUM>. Similarly, the power source connected to the ventilation device <NUM> as described above is not limited to the power source of AC 200V, and may be, for example, another power source of AC 100V or the like.

The indoor unit <NUM> includes an indoor unit controller <NUM>. The indoor unit controller <NUM> includes a computer including a processor such as a CPU or MPU and a memory device such as a ROM, RAM or the like, and the controller functions as a controller that controls each part of the air conditioning system <NUM>. Alternatively, the indoor unit controller <NUM> may include a plurality of processors, or semiconductor chips.

The indoor unit controller <NUM> includes a printed circuit board (PCB) <NUM>. The PCB <NUM> is a so-called printed circuit board, and the PCB <NUM> is a circuit board on which a microcomputer and the processor forming the indoor unit controller <NUM>, a power source circuit and others are mounted.

The indoor unit controller <NUM> controls an operation of the indoor unit <NUM>, and controls each electrically connected part of the air conditioning system <NUM>. For example, the indoor unit controller <NUM> operates a fan motor of the indoor fan <NUM> with the power supplied through the feed line <NUM>.

The PCB <NUM> may be connected to a remote control light receiving unit or an operation panel. In this case, the indoor unit controller <NUM> performs, for example, change of a target temperature based on an operation of a remote controller or the operation panel, and controls the operation of the indoor unit <NUM> at the target temperature. Furthermore, the indoor unit controller <NUM> may include a function of transmitting data concerning the operating state to the control device <NUM>.

A feed line <NUM> is disposed between the PCB <NUM> and the refrigerant leakage detection sensor <NUM>. The feed line <NUM> branches and outputs power fed through the feed line <NUM> to the refrigerant leakage detection sensor <NUM>. Therefore, the power of AC 200V is supplied to the refrigerant leakage detection sensor <NUM>.

The feed line <NUM> is connected to the PCB <NUM>. Consequently, for example, the power of AC 200V is supplied from the commercial AC power source <NUM> to the PCB <NUM>.

The refrigerant leakage detection sensor <NUM> is connected to the PCB <NUM> through a signal line <NUM>.

A control signal generated by the PCB <NUM> is transmitted to the refrigerant leakage detection sensor <NUM> via the signal line <NUM>. A specific form of the signal line <NUM> is arbitrary, and may be, for example, a line electrically connecting the PCB <NUM> and the refrigerant leakage detection sensor <NUM>, or a communication line via which the control signal is transmitted based on a predetermined communication protocol. Alternatively, the connection may be performed via a wireless communication circuit. Note that in the present embodiment, a form of another signal line to be described later is the same as in the signal line <NUM>.

Alternatively, the refrigerant leakage detection sensor <NUM> may be connected to the commercial AC power source <NUM> without being connected via the PCB <NUM>. In this case, the refrigerant leakage detection sensor <NUM> is connected to the PCB <NUM> in a wireless or wired manner, and the refrigerant leakage detection sensor <NUM> may be controlled by the PCB <NUM>.

Further, in this case, a controller may be mounted in the refrigerant leakage detection sensor <NUM>, and the refrigerant leakage detection sensor <NUM> may be controlled by this controller.

The control signal is a signal to instruct driving or stopping of the refrigerant leakage detection sensor <NUM> via the signal line <NUM>. Upon receiving this control signal, the refrigerant leakage detection sensor <NUM> is driven to detect refrigerant leakage, or stops the driving.

Also, the indoor unit controller <NUM> monitors a detecting state of the refrigerant leakage detection sensor <NUM> via the signal line <NUM>, and detects the leakage of the refrigerant by use of the refrigerant leakage detection sensor <NUM>. Furthermore, the indoor unit controller <NUM> determines, via the signal line <NUM>, whether or not the refrigerant leakage detection sensor <NUM> can normally detect the leakage of the refrigerant.

The PCB <NUM> is connected to the ventilation device <NUM> through a signal line <NUM>. The signal line <NUM> transmits, to the ventilation device <NUM>, a control signal generated by the indoor unit controller <NUM>. This control signal is a signal for the indoor unit controller <NUM> to instruct the ventilation device <NUM> to start or stop driving. Upon receiving this control signal, the ventilation device <NUM> is driven to perform ventilation of the indoor space <NUM>, or stops the ventilation of the indoor space <NUM>.

A feed line <NUM> is disposed between the PCB <NUM> and the external power source kit <NUM>. The feed line <NUM> branches and outputs power fed through the feed line <NUM> to the external power source kit <NUM>. Therefore, power of AC 200V is supplied to the external power source kit <NUM>.

The PCB <NUM> is connected to the external power source kit <NUM> through a signal line <NUM>. The indoor unit controller <NUM> transmits a control signal via the signal line <NUM> to control the external power source kit <NUM>.

The indoor unit controller <NUM> includes a storage unit <NUM> that stores various types of data concerning an operation of each part of the air conditioning system <NUM>, and the operation of the indoor unit <NUM>.

As shown in <FIG>, the external power source kit <NUM> includes an external power source controller <NUM>, the power storage unit <NUM>, and a charging port <NUM>.

The power storage unit <NUM> is charged with a current supplied from the PCB <NUM> through the feed line <NUM>. The power storage unit <NUM> stores power, and maintains a charged state, while the current is supplied from the commercial AC power source <NUM> via the PCB <NUM>.

Also, the power storage unit <NUM> discharges in a case where the supplied current is stopped, and feeds, via a plurality of feed lines <NUM>, power to each part connected to the external power source kit <NUM>. The case where the supplied current is stopped corresponds to a case where output of the PCB <NUM> is stopped, for example, a case where power failure of the commercial AC power source <NUM> occurs.

In the present embodiment, the external power source kit <NUM> is connected to the refrigerant leakage detection sensor <NUM>, the ventilation device <NUM>, and the alarm device <NUM> via the respective feed lines <NUM>. For example, in the case where the power failure of the commercial AC power source <NUM> occurs, the power storage unit <NUM> of the external power source kit <NUM> supplies power to these devices. Consequently, in the air conditioning system <NUM>, even in the case where the power failure of the commercial AC power source <NUM> occurs, the refrigerant leakage detection sensor <NUM>, the ventilation device <NUM> and the alarm device <NUM> can be driven with the power from the external power source kit <NUM>.

The power storage unit <NUM> stores power in a secondary battery or a capacitor. In a configuration where the power storage unit <NUM> includes the secondary battery, such as a metallic hydrogen battery, a lithium battery or a lithium ion battery, a power storage capacity can be increased. Also, in a configuration where the power storage unit <NUM> includes the capacitor, immediate charging and discharging are possible. Further, a complicated circuit configuration such as a charging and discharging control circuit required for the secondary battery can be omitted, which is advantageous in terms of cost. It is desirable that the secondary battery or capacitor of the power storage unit <NUM> can store an amount of power that can operate, for a predetermined time, the respective devices connected to the power storage unit <NUM> via the feed lines <NUM>.

The charging port <NUM> included in the external power source kit <NUM> can be connected to an external battery, a power generator or the like to supply power to the power storage unit <NUM>. In the present embodiment, for example, in a case where the power failure of the commercial AC power source <NUM> continues for a long time, the power can be supplied to the power storage unit <NUM> by connecting, to the charging port <NUM>, a power source other than the commercial AC power source <NUM>, for example, a battery.

As described above, the external power source kit <NUM> includes the external power source controller <NUM>. The external power source controller <NUM> includes a computer including a processor such as a CPU or MPU, and a memory device such as a ROM or RAM in the same manner as in the indoor unit controller <NUM>. Alternatively, the external power source controller <NUM> may include a plurality of processors or semiconductor chips.

The external power source controller <NUM> functions as a controller that controls each part of the external power source kit <NUM>, for example, the power storage unit <NUM>.

Also, as described above, the external power source kit <NUM> is connected to the PCB <NUM> via the signal line <NUM>. The external power source controller <NUM> functions as a determination unit that determines, by acquiring a predetermined signal via the signal line <NUM>, whether or not the commercial AC power source <NUM> is in a power supply available state, that is, whether or not the commercial power source is in a power failure state.

In the present embodiment, the external power source kit <NUM> is connected to the refrigerant leakage detection sensor <NUM>, the ventilation device <NUM>, and the alarm device <NUM> via respective signal lines <NUM>.

Then, the external power source controller <NUM> functions as a controller that controls each part connected to the external power source kit <NUM> via each signal line <NUM>, in a case where the current supplied from the commercial AC power source <NUM> is stopped, the power storage unit <NUM> discharges, and the power is supplied to each part connected to the external power source kit <NUM> via a plurality of feed lines <NUM>.

Specifically, the external power source controller <NUM> transmits a control signal generated by the external power source controller <NUM> to the refrigerant leakage detection sensor <NUM> via the signal line <NUM>.

The control signal is a signal to instruct driving or stopping of the refrigerant leakage detection sensor <NUM> via the signal line <NUM>. Upon receiving this control signal, the refrigerant leakage detection sensor <NUM> is driven to perform detection of refrigerant leakage, or stops the driving.

In the present embodiment, the external power source controller <NUM> drives the refrigerant leakage detection sensor <NUM> in a case where the driving of the ventilation device <NUM> is stopped, and stops the refrigerant leakage detection sensor <NUM> in a case where the ventilation device <NUM> is driven.

In the case where the ventilation device <NUM> is driven, the leaked refrigerant is diffused in the indoor space <NUM> by the ventilation device <NUM>. Consequently, a concentration of refrigerant in the indoor space <NUM> is diluted. Therefore, the driving of the refrigerant leakage detection sensor <NUM> can be stopped, and power consumption of the power storage unit <NUM> can be effectively reduced.

Also, the external power source controller <NUM> intermittently drives the refrigerant leakage detection sensor <NUM>, in a case where a predetermined time or more elapses after start of power supply of the power storage unit <NUM> to the refrigerant leakage detection sensor <NUM>.

In detail, for a predetermined time after the driving of the ventilation device <NUM> is stopped, the concentration of the refrigerant in the indoor space <NUM> indicates a diluted state. Therefore, in the air conditioning system <NUM>, the driving of the refrigerant leakage detection sensor <NUM> can be stopped for the predetermined time after the driving of the ventilation device <NUM> is stopped. Then, in the air conditioning system <NUM>, the driving of the refrigerant leakage detection sensor <NUM> is stopped for the predetermined time, so that the power consumption of the power storage unit <NUM> can be effectively reduced.

Furthermore, it is further preferable that the external power source controller <NUM> intermittently drives the refrigerant leakage detection sensor <NUM>, in a case where a predetermined time or more elapses after the start of the power supply of the power storage unit <NUM> to the refrigerant leakage detection sensor <NUM>. Consequently, in the air conditioning system <NUM>, the power consumption of the power storage unit <NUM> can be effectively reduced.

In addition, in the case of intermittently driving the refrigerant leakage detection sensor <NUM>, the external power source controller <NUM> controls the refrigerant leakage detection sensor <NUM> such that a ratio of a stop time to a drive time in the refrigerant leakage detection sensor <NUM> increases as a predetermined time elapses after start of the intermittent driving.

In detail, as time elapses long after stop of the power supply from the commercial AC power source <NUM>, the refrigerant is less likely to leak into the indoor space <NUM>. Thus, in the air conditioning system <NUM>, as time elapses after the commercial power source is stopped, control is performed to increase the ratio of the stop time of the refrigerant leakage detection sensor <NUM> with the above elapse of time, so that the power consumption of the power storage unit <NUM> can be effectively reduced.

Furthermore, the external power source controller <NUM> monitors the detecting state of the refrigerant leakage detection sensor <NUM> via the signal line <NUM>, to detect the leakage of the refrigerant by use of the refrigerant leakage detection sensor <NUM>. Additionally, the external power source controller <NUM> determines, via the signal line <NUM>, whether or not the refrigerant leakage detection sensor <NUM> can normally detect the leakage of the refrigerant.

The external power source controller <NUM> is connected to the ventilation device <NUM> through the signal line <NUM>. Via the signal line <NUM>, a control signal generated by the external power source controller <NUM> is transmitted to the ventilation device <NUM>. This control signal is a signal for the external power source controller <NUM> to instruct the ventilation device <NUM> to start or stop driving. Upon receiving this control signal, the ventilation device <NUM> is driven to ventilate the indoor space <NUM>, or stops the ventilation of the indoor space <NUM>. That is, the external power source controller <NUM> controls the driving of the ventilation device <NUM> via the signal line <NUM>.

The external power source controller <NUM> is connected to the alarm device <NUM> through the signal line <NUM>. Via the signal line <NUM>, a control signal generated by the external power source controller <NUM> is transmitted to the alarm device <NUM>. This control signal is a signal to instruct the alarm device <NUM> to notify the management center that it is necessary to repair the refrigerant leakage detection sensor <NUM> or the ventilation device <NUM>, in a case where the driving of the sensor or the device cannot be confirmed. Upon receiving this control signal, the alarm device <NUM> notifies the management center that it is necessary to repair the sensor or the device.

Also, the external power source controller <NUM> transmits, via the signal line <NUM> to the alarm device <NUM>, a control signal to instruct the alarm device <NUM> to notify the management center that the refrigerant leakage detection sensor <NUM> detects the refrigerant. Upon receiving this control signal, the alarm device <NUM> notifies the management center that the refrigerant leakage detection sensor <NUM> detects the refrigerant.

The external power source controller <NUM> includes a storage unit <NUM> that stores various types of data concerning each part of the external power source kit <NUM>, and control of each part connected to the external power source kit <NUM>. For example, the storage unit <NUM> stores a floor area S (m<NUM>), leakage height H (m), LFL (vol%) and the like, and the external power source controller <NUM> acquires these values from the storage unit <NUM>.

Note that in the present embodiment, various numeric values of the floor area S (m<NUM>), leakage height H (m), LFL (vol%) and the like are inputted into the storage unit <NUM> by an operator when installing the air conditioning system <NUM>.

Hereinafter, the operation of the air conditioning system <NUM> including the above configuration will be described.

<FIG> and <FIG> are flowcharts showing the operation of the air conditioning system <NUM> in a case where the commercial AC power source <NUM> is in the power failure state.

As described above, in the air conditioning system <NUM>, power of AC 200V from the commercial AC power source <NUM> is supplied from the commercial AC power source <NUM> to the indoor unit <NUM>, the refrigerant leakage detection sensor <NUM>, the ventilation device <NUM>, the external power source kit <NUM>, and the alarm device <NUM>.

However, for example, power failure due to lightning strike occurs, and the power supply from the commercial AC power source <NUM> to the air conditioning system <NUM> stops. Thus, so-called power failure might occur.

In the case where the commercial AC power source <NUM> is in the power failure state, the external power source controller <NUM> detects that the power supply from the PCB <NUM> to the external power source kit <NUM> is stopped. Then, the external power source controller <NUM> controls the power storage unit <NUM> to start the power supply to the ventilation device <NUM>, and drives the ventilation device <NUM> to perform ventilation with a predetermined ventilation amount (step SA1).

Thus, during the power failure, the ventilation device <NUM> is immediately driven regardless of whether or not the refrigerant is detected by the refrigerant leakage detection sensor <NUM>, so that the air conditioning system <NUM> can reliably respond to the refrigerant leakage without delay, if the refrigerant leaks with the occurrence of the power failure. Consequently, the air conditioning system <NUM> can suppress increase in concentration of the refrigerant that leaks into the indoor space <NUM>.

Afterward, the external power source controller <NUM> determines whether or not the commercial AC power source <NUM> recovers from the power failure (step SA2). Specifically, the external power source controller <NUM> acquires a predetermined signal via the signal line <NUM> connected to the PCB <NUM>, to determine whether or not the commercial AC power source <NUM> is in the power failure state.

Note that in the step SA2, the external power source controller <NUM> may temporarily stop the ventilation device <NUM>.

When the external power source controller <NUM> determines that the commercial AC power source <NUM> recovers from the power failure (YES in step SA2), the external power source controller <NUM> stops the power supply from the power storage unit <NUM> to the ventilation device <NUM>, and also restarts the power supply from the commercial AC power source <NUM> to each part.

Next, the external power source controller <NUM> determines whether or not the refrigerant leakage detection sensor <NUM> normally functions (step SA3).

Specifically, the external power source controller <NUM> communicates with the refrigerant leakage detection sensor <NUM> via the signal line <NUM>, and determines whether or not a normal signal can be received from the refrigerant leakage detection sensor <NUM>.

In a case where it is determined that the refrigerant leakage detection sensor <NUM> normally functions (YES in step SA3), that is, in a case where the normal signal can be received from the refrigerant leakage detection sensor <NUM>, the external power source controller <NUM> drives the refrigerant leakage detection sensor <NUM>, and determines whether or not the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant (step SA4). Specifically, the external power source controller <NUM> acquires the detection result of the refrigerant leakage detection sensor <NUM> via the signal line <NUM>, to determine whether or not the refrigerant leakage detection sensor <NUM> detects the refrigerant.

When the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant (YES in step SA4), the external power source controller <NUM> continues driving the ventilation device <NUM>, and also drives the alarm device <NUM> (step SA5). The alarm device <NUM> notifies the management center that the refrigerant leakage detection sensor <NUM> detects the refrigerant.

Then, an operator is instructed by the management center to repair a refrigerant leakage portion (step SA6).

When the refrigerant leakage detection sensor <NUM> does not detect the leakage of the refrigerant in the step SA4 (NO in step SA4), the external power source controller <NUM> stops the ventilation device <NUM> (step SA7), and then the external power source controller <NUM> returns each part of the air conditioning system <NUM> to a usual operation (step SA8).

When it is determined in the step SA3 that the refrigerant leakage detection sensor <NUM> does not function normally (NO in step SA3), the external power source controller <NUM> continues driving the ventilation device <NUM>, and also drives the alarm device <NUM> (step SA5). The alarm device <NUM> notifies the management center that the refrigerant leakage detection sensor <NUM> detects the refrigerant.

Then, the operator is instructed by the management center to repair the refrigerant leakage portion (step SA6).

Note that in the case where the external power source controller <NUM> determines in the step SA2 that the commercial AC power source <NUM> recovers from the power failure (YES in step SA2), the control of each part of the air conditioning system <NUM> may be switched from the external power source controller <NUM> to the PCB <NUM>.

When the external power source controller <NUM> determines in the step SA2 that the commercial AC power source <NUM> does not recover from the power failure (NO in step SA <NUM>), the external power source controller <NUM> determines whether or not the refrigerant leakage detection sensor <NUM> normally functions (step SA9).

In a case where it is determined that the refrigerant leakage detection sensor <NUM> normally functions (YES in step SA9), that is, in a case where the normal signal can be received from the refrigerant leakage detection sensor <NUM>, the external power source controller <NUM> continues the operation of the ventilation device <NUM> for a predetermined time (step SA10).

Here, description is made as to a ventilation time that is the predetermined time for which the external power source controller <NUM> continues the operation of the ventilation device <NUM> in the step SA10.

In a case where the external power source controller <NUM> determines that the power failure of the commercial AC power source <NUM> occurs and that the refrigerant leakage detection sensor <NUM> can normally detect the leakage of the refrigerant, a time to drive the ventilation device <NUM>, that is, the ventilation time (predetermined time) is determined by using a remaining amount of power in the power storage unit <NUM>, and set time T1 or T2.

The set time T1 is calculated by using the following equation (<NUM>).

In Equation (<NUM>), T1 (s) is the ventilation time, Vr (m<NUM>) is a predetermined volume in the indoor space <NUM>, and M (m<NUM>/s) is a ventilation amount of the ventilation device <NUM> per unit time.

In detail, T1 is a time when the ventilation device <NUM> can ventilate an indoor volume or air that is a volume of the indoor space <NUM> (time required for the ventilation of the indoor volume of air).

In the present embodiment, the volume Vr (m<NUM>) is determined by a product of the floor area S (m<NUM>) and the leakage height H (m). Note that the leakage height H is a height from a floor surface of the indoor space <NUM> to a portion into which the refrigerant is assumed to leak.

The set time T2 is a ventilation time by the ventilation device <NUM> until a concentration of the indoor space <NUM> reaches a concentration (<NUM>/<NUM> LFL) of a half of a lower flammability limit (LFL).

Note that the set time T2 is calculated as a time to reach <NUM>/<NUM> LFL in the indoor volume, but the present invention is not limited to this example. For example, in a case where it is supposed that the refrigerant leaks into the indoor space <NUM> during the power failure of the commercial AC power source <NUM>, the ventilation may be performed until the refrigerant concentration of the indoor space <NUM> reaches a predetermined concentration or less. The time required until the refrigerant concentration of the indoor space <NUM> reaches the predetermined concentration or less may be, for example, a ventilation time required until the concentration decreases to be less than <NUM>/<NUM> LFL in the indoor volume.

Furthermore, a lower limit value of the ventilation time required by the ventilation device <NUM> is not limited to the above T2, and may be acquired, for example, from a necessity determination tool disposed in the indoor space <NUM> or the like. With the necessity determination tool, it is determined whether or not an R32 safety device is necessary.

The external power source controller <NUM> sets the set time T1 as an upper limit value of the ventilation time by the ventilation device <NUM>, and sets the set time T2 as a lower limit value of the ventilation time by the ventilation device <NUM>. Then, the external power source controller <NUM> determines the ventilation time between the set time T1 and the set time T2 depending on the remaining amount of power in the power storage unit <NUM>, and the controller drives the ventilation device <NUM> for the ventilation time.

Note that the set time T1 or T2 may be calculated in consideration of a refrigerant leakage speed.

Also, the external power source controller <NUM> intermittently drives the ventilation device <NUM>, in a case where the predetermined time or more elapses after the start of the power supply from the power storage unit <NUM> to the ventilation device <NUM>. Specifically, the external power source controller <NUM> intermittently supplies the power of the power storage unit <NUM> to the ventilation device <NUM>, in the case where the predetermined time or more elapses after the start of the power supply from the power storage unit <NUM> to the ventilation device <NUM>.

Additionally, in the case of intermittently driving the ventilation device <NUM>, the external power source controller <NUM> stops the ventilation device <NUM> for a longer time as time elapses. Specifically, the external power source controller <NUM> lengthens a time to stop the power supply from the power storage unit <NUM> to the ventilation device <NUM>, with increase in operation times of the ventilation device <NUM>.

Alternatively, in the case of intermittently driving the ventilation device <NUM>, the external power source controller <NUM> may decrease the ventilation amount of the ventilation device <NUM> as time elapses.

As shown in <FIG>, the external power source controller <NUM> stops the ventilation device <NUM>, when the above ventilation time elapses (step SA11). Furthermore, the external power source controller <NUM> drives the refrigerant leakage detection sensor <NUM>, when the predetermined time elapses after the stop of the ventilation device <NUM> (step SA12).

In detail, the refrigerant concentration of the indoor space <NUM> is diluted immediately after the stop of the operation of the ventilation device <NUM>, and hence the refrigerant leakage detection sensor <NUM> is less likely to be driven. Therefore, in the air conditioning system <NUM>, in the step SA12, the refrigerant leakage detection sensor <NUM> is not energized immediately after the stop of the operation of the ventilation device <NUM>, so that a power amount to energize the refrigerant leakage detection sensor <NUM> can be reduced.

Furthermore, the refrigerant leakage detection sensor <NUM> is driven when the predetermined time elapses after the ventilation is performed by the ventilation device <NUM>, and the refrigerant leakage detection sensor <NUM> performs the detection in a state where a predetermined amount of refrigerant is retained in a case where the leakage of the refrigerant occurs. Consequently, in the air conditioning system <NUM>, missing detection by the refrigerant leakage detection sensor <NUM> can be inhibited, the drive time of the refrigerant leakage detection sensor <NUM> can be shortened, and decrease in amount of power stored in the power storage unit <NUM> can be suppressed.

Note that in the present embodiment, the predetermined time required until the refrigerant leakage detection sensor <NUM> is driven after the stop of the ventilation device <NUM> is a time calculated from the leakage speed and LFL, the leakage speed of the refrigerant being set to <NUM>/h.

As shown in <FIG>, the external power source controller <NUM> drives the refrigerant leakage detection sensor <NUM>, and then determines whether or not the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant (step SA13).

In a case where the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant (YES in step SA13), the external power source controller <NUM> stops the driving of the refrigerant leakage detection sensor <NUM>, and drives the ventilation device <NUM> and the alarm device <NUM> (step SA14). The alarm device <NUM> notifies the management center that the refrigerant leakage detection sensor <NUM> detects the refrigerant.

In the case where the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant, the external power source controller <NUM> drives the ventilation device <NUM> as in the step SA14, so that in the air conditioning system <NUM>, the refrigerant that leaks into the indoor space <NUM> is diffused, and the concentration of the refrigerant can be effectively diluted.

Hereinafter, continuously driving the ventilation device <NUM> over a predetermined time as in the step SA14 will be referred to as a first ventilating operation of the ventilation device <NUM>.

Further, in the step SA14, the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> are inhibited from being simultaneously driven. Consequently, in the air conditioning system <NUM>, decrease in amount of power stored in the power storage unit <NUM> can be suppressed.

The external power source controller <NUM> controls the ventilation device <NUM> to perform a so-called intermittent operation of alternately repeating driving and stopping of the ventilation device <NUM>, when a predetermined time elapses after the first ventilating operation of the ventilation device <NUM> is executed (step SA15).

Consequently, in the air conditioning system <NUM>, the decrease in amount of power stored in the power storage unit <NUM> can be suppressed more than in a case of continuously driving the ventilation device <NUM>.

Hereinafter, the intermittent operation of the ventilation device <NUM> to be performed when the predetermined time elapses after the first ventilating operation of the ventilation device <NUM> is executed will be referred to as a second ventilating operation of the ventilation device <NUM>.

In the case where the refrigerant leakage occurs, an amount of the refrigerant that leaks decreases with elapse of time. Specifically, in the air conditioning system <NUM>, a required ventilation amount decreases with elapse of time.

Consequently, in the step SA15, the external power source controller <NUM> more relatively extends a stop time than a drive time in the intermittent operation of the ventilation device <NUM>, with elapse of time after the ventilation device <NUM> is driven. In other words, the external power source controller <NUM> extends the stop time of the ventilation device <NUM> more than in the second ventilating operation, while continuing the intermittent operation of the ventilation device <NUM>, when the predetermined time elapses after the second ventilating operation of the ventilation device <NUM> is executed.

Thus, in the air conditioning system <NUM>, the drive time of the ventilation device <NUM> can be shortened, and the decrease in amount of power stored in the power storage unit <NUM> can be suppressed, before the refrigerant leakage portion is repaired.

Hereinafter, driving the ventilation device <NUM> to extend the stop time of the ventilation device <NUM> more than in the second ventilating operation while continuing the intermittent operation of the ventilation device <NUM> when the predetermined time elapses after the second ventilating operation of the ventilation device <NUM> is executed will be referred to as a third ventilating operation of the ventilation device <NUM>.

Note that instead of extending the stop time of the ventilation device <NUM> with the above elapse of time, the external power source controller <NUM> may decrease the ventilation amount in the case of driving the ventilation device <NUM> with the elapse of time. In this case, power consumption of the ventilation device <NUM> can be reduced, and the decrease in amount of power stored in the power storage unit <NUM> can be suppressed.

Hereinafter, driving the ventilation device <NUM> to decrease the ventilation amount with the elapse of time will be referred to as a fourth ventilating operation of the ventilation device <NUM>.

Furthermore, the external power source controller <NUM> may control the ventilation device <NUM> both to more relatively extend the stop time of the ventilation device <NUM> than the drive time and to decrease the ventilation amount of the ventilation device <NUM>, with elapse of time. In other words, the external power source controller <NUM> may control the ventilation device <NUM> to simultaneously execute the third ventilating operation and the fourth ventilating operation.

Afterward, the operator is instructed by the management center to perform the repair of the refrigerant leakage portion (step SA16). Upon completing the repair of the refrigerant leakage portion by the operator, the ventilation device <NUM> is stopped, for example, by the operator.

In the step SA13, even in a case where the refrigerant leakage detection sensor <NUM> does not detect the leakage of the refrigerant (NO in step SA13), the refrigerant leakage speed is low, that is, so-called slow leak might occur.

To solve this problem, in the present embodiment, in a case where the slow leak of the refrigerant occurs, when the refrigerant leakage detection sensor <NUM> does not detect the leakage of the refrigerant (YES in step SA17 and NO in step SA18) even with elapse of time required until the concentration of the refrigerant in the indoor space <NUM> decreases to the concentration of a half of LFL (<NUM>/<NUM> LFL) due to the slow leak, the refrigerant leakage detection sensor <NUM> is intermittently driven (step SA19). Consequently, in the air conditioning system <NUM>, the decrease in amount of power stored in the power storage unit <NUM> can be suppressed more than in the case of continuously driving the refrigerant leakage detection sensor <NUM>.

Note that in the present embodiment, when time elapses to obtain <NUM>/<NUM> LFL, the refrigerant leakage detection sensor <NUM> is intermittently driven, but the present invention is not limited to this example. Specifically, in the case where the slow leak of the refrigerant occurs in the indoor space <NUM>, time may elapse such that the refrigerant leakage detection sensor <NUM> can detect the refrigerant.

Further, in the step SA19, the external power source controller <NUM> may extend the stop time of the refrigerant leakage detection sensor <NUM>, with elapse of time. Consequently, in the air conditioning system <NUM>, the time to drive the refrigerant leakage detection sensor <NUM> can be shortened, and the decrease in amount of power stored in the power storage unit <NUM> can be suppressed, before the commercial AC power source <NUM> recovers.

In a case where the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant (YES in step SA18), the external power source controller <NUM> controls each part of the air conditioning system <NUM> to perform the above steps SA14 to SA16.

In a case where it is determined in the step SA9 that the refrigerant leakage detection sensor <NUM> does not function normally (NO in step SA9), the external power source controller <NUM> controls the ventilation device <NUM> to perform the same driving as in the step SA15. That is, the second ventilating operation by the ventilation device <NUM> is executed. Also, the external power source controller <NUM> drives the alarm device <NUM> (step SA21). The alarm device <NUM> notifies the management center that the refrigerant leakage detection sensor <NUM> detects the refrigerant.

Note that the present invention is not limited to this example, and the first ventilating operation of the ventilation device <NUM> may be executed in the step SA21 in the same manner as in the step SA14.

Consequently, in the air conditioning system <NUM>, the drive time of the ventilation device <NUM> can be shortened, and the decrease in amount of power stored in the power storage unit <NUM> can be suppressed, before the refrigerant leakage portion is repaired.

Then, the operator is instructed by the management center to perform the repair of the refrigerant leakage portion (step SA22).

As described above, in the present embodiment, the air conditioning system <NUM> includes the refrigeration cycle to circulate the refrigerant, the indoor unit <NUM> including the indoor heat exchanger <NUM> connected to the refrigeration cycle, the indoor unit being installed in the indoor space <NUM>, the refrigerant leakage detection sensor <NUM> that detects the refrigerant leaking from the indoor unit <NUM>, the ventilation device <NUM> that ventilates the indoor space, the power storage unit <NUM> that is charged by the external power source kit <NUM>, and the external power source controller <NUM>. The refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> are operated by the commercial AC power source <NUM>, and the external power source controller <NUM> operates the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> with the power of the power storage unit <NUM> depending on the remaining amount of power in the power storage unit <NUM>, in the case where the supply from the commercial AC power source <NUM> is stopped.

Consequently, in the air conditioning system <NUM>, the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> are driven depending on the remaining amount of power in the power storage unit <NUM> in the case where the commercial AC power source <NUM> is in the power failure state.

Therefore, in the air conditioning system <NUM>, a plurality of devices for the countermeasures against the refrigerant leakage can be driven for a predetermined time, even if the commercial AC power source <NUM> is in the power failure state.

As in the present embodiment, the external power source controller <NUM> may operate the ventilation device <NUM> with the power of the power storage unit <NUM>, to ventilate an indoor volume of air in the indoor space <NUM>, in the case where the supply from the commercial AC power source <NUM> is stopped.

Consequently, in the air conditioning system <NUM>, the ventilation device <NUM> is driven with the amount of the power in the power storage unit <NUM> in the case where the commercial AC power source <NUM> is in the power failure state.

Therefore, in the air conditioning system <NUM>, even if the commercial AC power source <NUM> is in the power failure state, the ventilation device <NUM> is driven to diffuse the refrigerant that leaks into the indoor space <NUM>, and the concentration of the refrigerant can be effectively diluted.

As in the present embodiment, the external power source controller <NUM> may operate the ventilation device <NUM> for a predetermined time, depending on the remaining amount of power in the power storage unit <NUM> and a ventilation amount of the ventilation device <NUM>, when operating the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> with the power of the power storage unit <NUM>.

Consequently, in the air conditioning system <NUM>, the drive time of the ventilation device <NUM> is determined depending on the concentration of the refrigerant and the ventilation amount of the ventilation device <NUM> in the indoor space <NUM> provided with the indoor unit <NUM>, and the remaining amount of power in the power storage unit <NUM>.

Therefore, in the air conditioning system <NUM> can suppress the decrease in amount of power in the power storage unit <NUM>, while driving the ventilation device <NUM> with the ventilation amount that can sufficiently decrease the concentration of the refrigerant that leaks into the indoor space <NUM> provided with the indoor unit <NUM>.

As in the present embodiment, the external power source controller <NUM> may operate the ventilation device <NUM> for a time or more when a refrigerant concentration in the indoor space <NUM> decreases to the predetermined value or less, in the case where it is supposed that the refrigerant leaks into the indoor space <NUM> during power failure.

Consequently, in the air conditioning system <NUM>, in the case where the commercial AC power source <NUM> is in the power failure state and the refrigerant leaks into the indoor space <NUM>, the ventilation device <NUM> is driven with the power of the power storage unit <NUM> over the time or more when the refrigerant concentration in the indoor space can decrease.

Therefore, in the air conditioning system <NUM>, even if the commercial AC power source <NUM> is in the power failure state, the ventilation device <NUM> can be driven to diffuse the refrigerant that leaks into the indoor space <NUM>, and the concentration of the refrigerant can be more reliably diluted.

As in the present embodiment, the time when the refrigerant concentration in the indoor space <NUM> decreases to the predetermined value or less may be equal to or less than a time required for the ventilation device <NUM> to ventilate the indoor volume of air.

Consequently, in the air conditioning system <NUM>, in the case where the refrigerant leaks into the indoor space <NUM>, the ventilation device <NUM> is driven in the drive time equal to or less than the time required to ventilate the whole indoor volume that is the volume of the indoor space.

Therefore, in the air conditioning system <NUM>, the ventilation device <NUM> is driven to diffuse the refrigerant that leaks into the indoor space <NUM> while suppressing the decrease in amount of power stored in the power storage unit <NUM>, so that the refrigeration concentration in the indoor space <NUM> can be diluted to the predetermined value or less.

As in the present embodiment, the external power source controller <NUM> may operate the refrigerant leakage detection sensor <NUM> with the power of the power storage unit <NUM>, in the case where the supply from the commercial AC power source <NUM> is stopped and may execute a first ventilating operation, the first ventilating operation including operating the ventilation device <NUM> with the power of the power storage unit <NUM>, in at least one of a case where the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant and the case where it is determined that the refrigerant leakage detection sensor <NUM> does not function normally.

Consequently, in the air conditioning system <NUM>, the ventilation device <NUM> is driven depending on the detection result or the detecting state of the refrigerant leakage detection sensor <NUM>, in the case where the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> are driven with the power of the power storage unit <NUM>. Therefore, in the air conditioning system <NUM>, the ventilation device <NUM> is driven, while suppressing the decrease in amount of power stored in the power storage unit <NUM>, so that the refrigerant that leaks into the indoor space <NUM> can be more reliably diffused.

As in the present embodiment, the external power source controller <NUM> may execute a second ventilating operation, the second ventilating operation including alternately repeating driving and stopping of the ventilation device <NUM>, when a predetermined time elapses after the first ventilating operation is started.

Consequently, in the air conditioning system <NUM>, the time to drive the ventilation device <NUM> in the predetermined time can be shortened, and the decrease in amount of power stored in the power storage unit <NUM> can be suppressed.

Therefore, in the air conditioning system <NUM>, the ventilation device <NUM> can be driven over a long period.

As in the present embodiment, the external power source controller <NUM> may execute a third ventilating operation, the third ventilating operation including alternately repeating the driving and stopping of the ventilation device <NUM>, and lengthening the stop time of the ventilation device <NUM> more than in the second ventilating operation, when the predetermined time elapses after the second ventilating operation is executed.

Consequently, in the air conditioning system <NUM>, the time to drive the ventilation device <NUM> in the predetermined time can be shortened more, and the decrease in amount of power stored in the power storage unit <NUM> can be suppressed.

Therefore, in the air conditioning system <NUM>, the ventilation device <NUM> can be driven over a longer period.

As in the present embodiment, the external power source controller <NUM> may execute a fourth ventilating operation, the fourth ventilating operation including decreasing a ventilation amount of the ventilation device <NUM>, when a predetermined time elapses after the first ventilating operation is started.

Consequently, in the air conditioning system <NUM>, a drive amount of the ventilation device <NUM> in the predetermined time can be reduced, and the consumption of the power stored in the power storage unit <NUM> can be reduced.

As in the present embodiment, the external power source controller <NUM> may operate the ventilation device <NUM>, in a state where supply of power to the refrigerant leakage detection sensor <NUM> is stopped, in a case of operating the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> with the power of the power storage unit <NUM>.

Consequently, the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> are inhibited from being simultaneously driven.

Therefore, in the air conditioning system <NUM>, the decrease in amount of power stored in the power storage unit <NUM> can be suppressed.

As in the present embodiment, the external power source controller <NUM> may operate the refrigerant leakage detection sensor <NUM> when a predetermined time elapses after the ventilation device <NUM> is stopped, in a case of operating the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> with the power of the power storage unit <NUM>.

Consequently, the refrigerant leakage detection sensor <NUM> performs detection in the state where the predetermined amount of refrigerant is retained, in the case where the leakage of the refrigerant occurs. Therefore, in the air conditioning system <NUM>, the missing detection by the refrigerant leakage detection sensor <NUM> can be inhibited, the drive time of the refrigerant leakage detection sensor <NUM> can be shortened, and the decrease in amount of power stored in the power storage unit <NUM> can be suppressed.

As in the present embodiment, the external power source controller <NUM> may intermittently operate the refrigerant leakage detection sensor <NUM>, when a time elapses until the refrigerant reaches a predetermined concentration, after one of stop of the ventilation device <NUM> and start of the operation of the refrigerant leakage detection sensor <NUM>, in the case where the supply from the commercial AC power source <NUM> is stopped.

Consequently, in the air conditioning system <NUM>, the time to drive the refrigerant leakage detection sensor <NUM> in the predetermined time can be shortened, and the decrease in amount of power stored in the power storage unit <NUM> can be suppressed.

Therefore, in the air conditioning system <NUM>, the refrigerant leakage detection sensor <NUM> can be driven over a longer period.

<FIG> is a block diagram showing a configuration of an air conditioning system <NUM> according to Embodiment <NUM>.

In <FIG>, the same part as in <FIG> is denoted with the same reference sign and description thereof is omitted.

The air conditioning system <NUM> according to Embodiment <NUM> is different from the air conditioning system <NUM> according to Embodiment <NUM> in that at least a heat source sensing sensor <NUM> is disposed. The heat source sensing sensor <NUM> is an example of a device that detects whether or not a person or a thing that may be affected by a refrigerant that leaks into an indoor space <NUM> provided with indoor unit <NUM> of the air conditioning system <NUM>.

In the present embodiment, the heat source sensing sensor <NUM> is disposed in the indoor space <NUM>. The heat source sensing sensor <NUM> may be disposed integrally with the indoor unit <NUM>.

The heat source sensing sensor <NUM> is a heat sensor that senses a heat source emitting a predetermined or more temperature in the indoor space, for example, an infrared detector or a thermistor. The heat source sensing sensor <NUM> of the present embodiment senses the heat source at a temperature equal to or more than a temperature at which the heat source can be an ignition source of a refrigerant for use in the air conditioning system <NUM>. Examples of this heat source include fire of a lighter, and an electric heater.

Note that the air conditioning system <NUM> is not limited to the heat sensor, and the heat source may be detected with a camera or the like.

The heat source sensing sensor <NUM> is configured to communicate with each of an indoor unit controller <NUM> and an external power source controller <NUM>. Each of the indoor unit controller <NUM> and the external power source controller <NUM> can acquire the detection result of the heat source sensing sensor <NUM>.

Hereinafter, an operation of the air conditioning system <NUM> including the above configuration will be described.

<FIG> is a flowchart showing the operation of the air conditioning system <NUM> in a case where a commercial AC power source <NUM> is in a power failure state.

As described above, in the air conditioning system <NUM>, in the case where the commercial AC power source <NUM> is in the power failure state, the external power source controller <NUM> detects that power supply from a PCB <NUM> to an external power source kit <NUM> is stopped. Then, the external power source controller <NUM> drives a refrigerant leakage detection sensor <NUM>, and determines whether or not the refrigerant leakage detection sensor <NUM> detects leakage of the refrigerant (step SB1).

In a case where it is determined that the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant (YES in step SB1), the external power source controller <NUM> drives a ventilation device <NUM>, stops the driving of the refrigerant leakage detection sensor <NUM>, and drives an alarm device <NUM> (step SB2). The alarm device <NUM> notifies a management center that the refrigerant leakage detection sensor <NUM> detects the refrigerant.

Also, the refrigerant leakage detection sensor <NUM> and the ventilation device <NUM> are inhibited from being simultaneously driven, and decrease in amount of power stored in a power storage unit <NUM> is accordingly suppressed.

Then, an operator is instructed by the management center to repair a refrigerant leakage portion (step SB3).

In a case where it is determined in the step SB1 that the refrigerant leakage detection sensor <NUM> does not detect the leakage of the refrigerant (NO in step SB1), the external power source controller <NUM> drives the heat source sensing sensor <NUM>, to detect from the detection result of the heat source sensing sensor <NUM> whether or not the heat source at the temperature equal to or more than the temperature at which the heat source can be the ignition source of the refrigerant is present (step SB4).

In a case where it is determined that the heat source is present (YES in step SB4), the external power source controller <NUM> drives the ventilation device <NUM>, and stops the driving of the refrigerant leakage detection sensor <NUM> (step SB5).

Then, the external power source controller <NUM> operates the ventilation device <NUM> for a predetermined time, and then stops the ventilation device (step SB6). Here, this predetermined time is a ventilation time between a set time T1 that is an upper limit value and a set time T2 that is a lower limit value as described in Embodiment <NUM>, the ventilation time being determined by the external power source controller <NUM> depending on a remaining amount of power in the power storage unit <NUM>.

The external power source controller <NUM> stops the ventilation device <NUM>, and then drives the refrigerant leakage detection sensor <NUM>, to determine whether or not the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant (step SB7).

In a case where it is determined that the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant (YES in step SB7), the external power source controller <NUM> controls each part of the air conditioning system <NUM>, to perform the steps SB2 and SB3.

In a case where it is determined in the step SB7 that the refrigerant leakage detection sensor <NUM> does not detect the leakage of the refrigerant (NO in step SB7), the external power source controller <NUM> stops the driving of the refrigerant leakage detection sensor <NUM> (step SB8). Then, it is determined whether or not the commercial AC power source <NUM> recovers from the power failure state (step SB9). In a case where it is determined that the commercial AC power source <NUM> recovers from the power failure state, the external power source controller <NUM> returns the air conditioning system <NUM> to a usual operation (step SB10).

In a case where it is determined in the step SB4 that the heat source is present in the indoor space <NUM> (NO in step SB11), the external power source controller <NUM> continuously stops the ventilation device <NUM>, and drives the refrigerant leakage detection sensor <NUM> (step SB11). Then, the refrigerant leakage detection sensor <NUM> performs the step SB7 to determine whether or not the refrigerant leakage detection sensor <NUM> detects the leakage of the refrigerant.

Note that in Embodiment <NUM>, the air conditioning system <NUM> is controlled by determining whether or not the heat source is present in the indoor space <NUM> by use of the heat source sensing sensor <NUM>. However, the present disclosure is not limited to this example. For example, the air conditioning system <NUM> may be controlled depending on a detection result obtained by detecting whether or not and how many persons are present in the indoor space <NUM>, by use of a camera, an objective sensor, a human detection sensor or the like. Furthermore, when making these determinations, the predetermined volume Vr in the indoor space <NUM>, the volume of the whole indoor space <NUM> or the like may be reflected.

As above, Embodiments <NUM> and <NUM> have been described as illustration of a technology disclosed in the present application. However, the technology in the present invention is not limited to this illustration, and is also applicable to an embodiment subjected to change, replacement, addition, omission or the like. Also, respective constituent elements described above in Embodiments <NUM> and <NUM> may be combined, to form a new embodiment.

Then, the other embodiment will be illustrated hereinafter.

In the above embodiments, there are not restrictions on the numbers of units of the outdoor unit <NUM> and the indoor unit <NUM> included in the air conditioning systems <NUM> and <NUM>. For example, the air conditioning system <NUM> may include a configuration where one unit of the outdoor unit <NUM> is connected to one unit of the indoor unit <NUM>.

In the above embodiments, in the configurations of <FIG> and <FIG>, power is supplied from the common commercial AC power source <NUM> to the device to which commercial power supply is available, but the present disclosure is not limited to this example, and the commercial AC power sources <NUM> may be provided independently to some or all of the devices, respectively. That is, a plurality of commercial AC power sources <NUM> may be connected to each of the air conditioning systems <NUM> and <NUM>.

The refrigerant leakage detection sensor <NUM> may be disposed in the housing of the indoor unit <NUM>. In this case, in the above step SA12, the refrigerant leakage detection sensor <NUM> may be driven immediately after the ventilation device <NUM> is stopped. Further, in this case, the step SA17 may be omitted.

Claim 1:
An air conditioning system (<NUM>; <NUM>) comprising:
a refrigeration cycle to circulate a slightly flammable refrigerant or a flammable refrigerant, and
an indoor unit (<NUM>) including a heat exchanger (<NUM>) connected to the refrigeration cycle, the indoor unit (<NUM>) being installed in an indoor space (<NUM>), the air conditioning system (<NUM>; <NUM>) comprising:
a refrigerant sensor (<NUM>) that detects the refrigerant leaking from the indoor unit (<NUM>),
a ventilation device (<NUM>) that ventilates the indoor space,
a power storage unit (<NUM>) that is charged by a commercial power source (<NUM>), and
a controller (<NUM>), wherein the refrigerant sensor (<NUM>) and the ventilation device (<NUM>) are operated by the commercial power source (<NUM>),
characterized in that
the controller (<NUM>) operates the ventilation device (<NUM>) with power of the power storage unit (<NUM>), regardless of whether or not the refrigerant leaking is detected by the refrigerant sensor (<NUM>), in a case where the controller (<NUM>) detects that a power supply from the commercial power source (<NUM>) is stopped;
the controller (<NUM>) operates the refrigerant sensor (<NUM>) with power of the power storage unit (<NUM>) and determines whether or not the refrigerant sensor (<NUM>) normally functions when the power supply from the commercial power source (<NUM>) does not recover from the power failure after operating the ventilation device (<NUM>); and
the controller (<NUM>) executes a first ventilation operation to operate the ventilation device (<NUM>) with power of the power storage unit (<NUM>) for a predetermined ventilation time that is calculated based on a remaining amount of power in the power storage unit (<NUM>), a volume in the indoor space, and a ventilation amount of the ventilation device (<NUM>) per unit time in a case where the controller (<NUM>) determines that the refrigerant sensor (<NUM>) normally functions.