Refrigerant Leak Detection System

This US Non-Provisional Patent Application relies on and claims priority to Japanese Patent Application No. 2024-098111, filed on Jun. 18, 2024, the entire contents of which are incorporated herein by reference.

An embodiment of the invention relates to a refrigerant leak detection system for detecting refrigerant leaks from an air conditioning system.

For example, as disclosed in Japanese Patent No. 7466061, a system configured such that a leakage of refrigerant used in a refrigeration cycle of an air conditioning system into the interior can be detected has been considered.

In this type of system, the refrigerant detection sensor that detects leaking refrigerant may be integrated with an alarm that gives an alarm when a leak is detected and placed outside the air conditioner, or it may be placed inside the air conditioner. In either form of arrangement, the refrigerant detection sensor is operated by power supplied from a commercial power source. However, with this conventional configuration, the refrigerant detection sensor cannot operate in the event of a power failure.

The embodiment relates to a refrigerant leak detection system that detects a refrigerant leak from an air conditioning system and provides a technical proposal that enables detection of leaking refrigerant even in the event of a power failure.

A refrigerant leak detection system according to an embodiment is a system that detects a refrigerant leak from an air conditioning system, the system including a detection alarm having a detection unit that detects leaking refrigerant and an alarm unit that alerts when the detection unit detects a refrigerant leak, a power feed adapter having a main power feed unit that supplies power to the detection alarm, and a sub power supply unit that is connected to the power feed adapter, wherein the power feed adapter supplies power to the detection alarm from the sub power supply unit if the main power supply unit becomes unable to supply power to the detection alarm.

An embodiment relating to a refrigerant leak detection system is described hereinafter with reference to drawings. A refrigerant leak detection systemillustrated inis a system that detects a refrigerant leak from an air conditioning systemand includes a detection alarmand a power feed adapter. The detection alarmand the power feed adapterare communicably connected to each other by a communication line L. The concept of communication in the present disclosure includes not only transmission and reception of various signals and data but also transmission and reception of power.

The detection alarmincludes a sensor boardand an alarm boardin a housingthat forms its outline. The sensor boardand the alarm boardare communicably connected to each other by a communication line L.

The sensor boardincludes a refrigerant detection sensorfor detecting refrigerant leaking from the air conditioning system. The refrigerant detection sensoris an example of a detection unit. The refrigerant detection sensoris configured by, for example, a refrigerant gas sensor capable of detecting gaseous refrigerant leaking into the air.

The alarm boardincludes an optical alarm unitand an audible alarm unit. The optical alarm unitand the audible alarm unitare both examples of an alarm unit. The optical alarm unitincludes an element capable of emitting light such as a light emitting diode (LED), for example, and is capable of alarming in a visual manner by outputting light. The audible alarm unitincludes an element capable of emitting sound such as a buzzer, for example, and is capable of alarming in an auditory manner by outputting sound.

The detection alarmincludes a control circuit, not shown, that controls overall operations of the detection alarm. The detection alarmis configured to alert through at least one of the optical alarm unitand the audible alarm unitwhen the refrigerant detection sensordetects a refrigerant leak.

The power feed adapterincludes a power supply boardwithin the housingthat forms its outline. The power supply boardincludes a commercial power supply unitand a battery power supply unitfor supplying power to the detection alarm. The commercial power supply unitcan supply power obtained from, for example, a commercial power sourceto the detection alarm. The commercial power sourceis an example of a main power supply unit.

A battery kitis removably connected to the battery power supply unit. The battery kitis an example of a sub power supply unit. The battery kitincludes, for example, a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery, or a capacitor, and is capable of storing and discharging electricity. The battery kitmay be located outside the housingor inside the housing.

The power feed adapterincludes a control circuit, not shown, that controls overall operations of the power feed adapter. The power feed adapteris configured to supply power to the detection alarmfrom the battery kitby the battery power supply unitwhen the commercial power supply unitis unable to supply power from the commercial power sourceto the detection alarmdue to, for example, power failure.

As illustrated in, the air conditioning systemis configured with a plurality of indoor units[A],[B] for one outdoor unit. The air conditioning systemincludes a refrigeration cycle that includes an outdoor heat exchanger, not shown, included in the outdoor unit, an indoor heat exchanger, not shown, included in each of the plurality of indoor units[A],[B], refrigerant pipes, not shown, that circulate refrigerant, a compressor, not shown, that compresses refrigerant, and an expansion valve, not shown, that expands the refrigerant.

The air conditioning systemfurther includes a shutoff device[A] that shuts off supply of refrigerant to the indoor unit[A] and a shutoff device[C] that shuts off supply of refrigerant to the indoor unit[B]. The shutoff device[A] and shutoff device[C] are interposed in a portion of the refrigerant piping that constitutes the refrigeration cycle between the outdoor unitand the indoor units[A],[B], not shown.

In the configuration example shown in, the indoor unit[A] and the shutoff device[A] are located in a room R [A]. The indoor unit[B] is located in a room R [B]. The shutoff device[C] is located in a room R [C].

A plurality of refrigerant leak detection systems[B],[C] are connected to the air conditioning system. The refrigerant leak detection systems[B] and[C] are both connected to the indoor unit[B]. However, the detection alarm[B] of the refrigerant leak detection system[B] is located in the room R [B]. On the other hand, the detection alarm[C] of the refrigerant leak detection system[C] is located in the room R [C].

The refrigerant leak detection system[B], in which the detection alarm[B] is located in the room R [B], has a predetermined association, or linkage, to the indoor unit[B]. On the other hand, the refrigerant leak detection system[C], in which the detection alarm[C] is located in room the room R [C], does not have a predetermined linkage to the indoor unit[B].

The predetermined linkage can be achieved, for example, by operating a link setting switch, not shown, provided on the power feed adapter[B] of the refrigerant leak detection system[B]. That is, in The embodiment, the link setting switch, not shown, provided on the power feed adapter[B] of the refrigerant leak detection system[B] is operated, but the link setting switch, not shown, provided on the power feed adapter[C] of the refrigerant leak detection system[C] is not operated. Therefore, the refrigerant leak detection system[B] is linked to the indoor unit[B], but the refrigerant leak detection system[C] is not linked to the indoor unit[B].

The refrigerant leak detection system[B], which has a predetermined linkage to the indoor unit[B], closes the shutoff device[C] that shuts off the supply of refrigerant to the indoor unit[B] when a refrigerant leak from the linked indoor unit[B] is detected by the detection alarm[B]. This stops the supply of refrigerant to the indoor unit[B] and can suppress refrigerant leak in the room R [B]. The detection alarm[B] also provides optical and audible alarms to report that a refrigerant leak is occurring in the room R [B].

The refrigerant leak detection system[C], which does not have a predetermined linkage to the indoor unit[B] stops operation of the entire air conditioning systemwhen a refrigerant leak from a component other than the indoor unit[B] linked to the refrigerant leak detection system[B], in this case, from the shutoff device[C], is detected by the detection alarm[C]. This stops the circulation of refrigerant in the air conditioning systemand can prevent a refrigerant leak in the room R [C]. The detection alarm[C] also provides optical and audible alarms to report that a refrigerant leak is occurring in the room R [C].

A central alarmis also connected to the air conditioning system. The central alarmis located in a central control room R [D], which is different from rooms R [A], R [B], and R [C]. The central alarm, like the detection alarm, is equipped with a light alarm section capable of alarming in a visual manner and a sound alarm section capable of alarming in an auditory manner. The central alarmis connected to the outdoor unitof the air conditioning systemvia an adapter.

When a refrigerant leak is detected by the detection alarm[B], the refrigerant leak detection system[B] transmits a leak occurrence signal indicating that a refrigerant leak is occurring in the room R [B] to the central alarmvia the indoor unit[B], indoor unit[A] and outdoor unit. This allows the central alarmto report that a refrigerant leak is occurring in the room R [B].

When a refrigerant leak is detected by the detection alarm[C], the refrigerant leak detection system[C] transmits a leak occurrence signal indicating that a refrigerant leak is occurring in the room R [C] to the central alarmvia the indoor unit[B], indoor unit[A] and outdoor unit. This allows the central alarmto report that a refrigerant leak is occurring in the room R [C].

According to the refrigerant leak detection systemillustrated above, the power feed adaptersupplies power to the detection alarmfrom the battery kitby the battery power supply unitwhen power supply from the commercial power sourceto the detection alarmis disabled. According to this configuration example, even if, for example, a power failure occurs and the supply of power from the commercial power sourceto the detection alarmis disabled, the power supplied from the battery kitcan operate the refrigerant detection sensorand maintain the state in which the refrigerant leaking from the air conditioning systemcan be detected.

According to the refrigerant leak detection system, when a refrigerant leak from the indoor unitto which a predetermined linkage is made is detected by the detection alarm, the shutoff devicethat shuts off the supply of refrigerant to the indoor unitis closed. According to this configuration example, it is possible to shut off the supply of refrigerant to the indoor unitthat has a high possibility of a refrigerant leak, that is, to pinpoint the supply of refrigerant to the indoor unitthat is likely to be the cause of the refrigerant leak.

According to the refrigerant leak detection system, if a refrigerant leak from one other than the indoor unithaving a predetermined linkage, in this case, from the shutoff deviceis detected by the detection alarm, the entire air conditioning systemwill stop operating.

Here, even if a refrigerant leak from the shutoff devicecould be detected, it is difficult to determine whether the leak is occurring upstream or downstream of the shutoff device. If a refrigerant leak is occurring upstream of the shutoff device, closing that shutoff devicewill not stop the refrigerant leak. Therefore, if a refrigerant leak from one other than the indoor unithaving a predetermined linkage is detected by the detection alarm, the entire air conditioning systemcan be stopped so as to prevent further refrigerant leakage, no matter at which position the refrigerant leak is occurring.

If the indoor unit[B] and the shutoff device[C] are located relatively close to each other, the single refrigerant leak detection systemmay be used to detect refrigerant leaks from these indoor units[B] and shutoff device[C].

According to the refrigerant leak detection system, the detection alarmand power feed adapterare provided as separate and independent components, which allows for improved flexibility in the installation of the detection alarmand power feed adapter. It also allows improved freedom in design of the detection alarmand power feed adapter, making each of them smaller and lighter. The refrigerant leak detection systemmay be configured with the detection alarmand the power feed adapterin the same housing.

According to the refrigerant leak detection system, the system can be operated by a power supply system different from the power supply system of the air conditioning systembecause it includes a dedicated power feed adapter. Therefore, even if an abnormality occurs in the power supply system of the air conditioning system, power can continue to be supplied to the refrigerant leak detection system, and the system will remain capable of detecting refrigerant leaks and providing alarms.

It should be noted that the embodiment is not limited to the aforementioned one embodiment, and various changes, extensions and so on can be made thereto without departing from the spirit and scope of the present invention. For example, communication between the refrigerant leak detection systemand the air conditioning systemand between the refrigerant leak detection systemand the shutoff devicemay be wired or wireless communication.

The link setting switch that links the refrigerant leak detection systemand the indoor unitmay be provided in the detection alarm, in the power feed adapter, or in the indoor unitinstead of the refrigerant leak detection system.

How the refrigerant leak detection systemand the indoor unitare linked may be set in such a way that, for example, a remote control unit or the like, which is provided so as to be capable of remotely operating the refrigerant leak detection system, is operated to make a setting. How the refrigerant leak detection systemand the indoor unitare linked may be set in such a way that, for example, the same address number or an associated address number is assigned to the refrigerant leak detection systemand the indoor unit.

How the refrigerant leak detection systemand indoor unitare linked may, for example, be achieved in such a way that different wiring configurations are used between the case of making a link and the case of not making a link. To be more specific, for example, it is conceivable to set in such a way that in a wiring configuration with which the refrigerant leak detection systemand the indoor unitare directly connected without other components therebetween, they are linked, and, in a wiring configuration with which the refrigerant leak detection systemand indoor unitare indirectly connected through other components, they are not linked.

The refrigerant leak detection systemdoes not necessarily have to be linked to the indoor unit. Also, for indoor unitsthat are not linked to the refrigerant leak detection system, a safety device separate from the refrigerant leak detection systemmay be installed, for example.

Also, the detection alarmmay further be configured to alarm by the optical alarm unitor the audible alarm unitwhen an abnormality occurs in the communication between the air conditioning systemand the power feed adapter. According to this configuration example, when an abnormality occurs in the operation of the air conditioning systemfor some reason, for example, when the power supply to the air conditioning systemis disabled due to a power failure or when the communication line connecting the air conditioning systemand the power feed adapteris disconnected, the detection alarmcan report that an abnormality has occurred in the operation of the air conditioning system.

Also, the detection alarmmay further be configured to alert by the optical alarm unitand the audible alarm unitwhen the power supply from the commercial power sourceis disabled, for example, due to a power failure. That is, according to the refrigerant leak detection systemof the present disclosure, the detection alarmcan be operated by power supply from the battery kitwhen the power supply from the commercial power sourceis disabled. Therefore, for example, if an abnormality occurs in the power supply system from the commercial power sourcefor some reason, the detection alarmcan report it.

Also, the detection alarmmay further be configured to alarm by the optical alarm unitor the audible alarm unitwhen an abnormality occurs in communication with the refrigerant detection sensor. According to this configuration example, if an abnormality occurs in the refrigerant detection sensorfor some reason, for example, if the refrigerant detection sensorfails or if the communication line Lis disconnected, the detection alarmcan report that an abnormality has occurred through the refrigerant detection sensor.

Also, the detection alarmmay further be configured to alarm by the optical alarm unitor the audible alarm unitwhen a failure signal is received as a predetermined signal from the refrigerant detection sensor. According to this configuration example, for example, if a failure occurs in the refrigerant detection sensorfor some reason, it can be reported by the detection alarm.

The refrigerant leak detection systemmay further be configured to perform a lifetime determination to determine whether the refrigerant detection sensoris normal or not based on the total energized time to the refrigerant detection sensor. According to this configuration example, it is possible to indicate when to inspect or replace the refrigerant detection sensoraccording to the age of use and deterioration of the refrigerant detection sensor, thereby avoiding the continued use of a refrigerant detection sensorthat is not working properly.

The refrigerant leak detection systemmay further be equipped with a monitoring function that monitors the communication status with the air conditioning system, and may be configured to switch the monitoring function between enabled and disabled states. According to the refrigerant leak detection systemwith the monitoring function switched to the enabled state, if an abnormality occurs in the operation of the air conditioning systemfor some reason, it can be reported. On the other hand, according to the refrigerant leak detection systemwith the monitoring function switched to the disabled state, there is no processing load to monitor the communication status with the air conditioning system, so resources can be concentrated on handling refrigerant leak detection and alarms. In other words, the refrigerant leak detection systemcan be operated in a so-called “stand-alone” form, allowing the system to specialize in handling refrigerant leak detection and alarms.

How the monitoring function is switched between the enabled and disabled states may be, for example, by operating a dip switch provided in the detection alarmor power feed adapter, or may be in any other way.

Also, the detection alarmmay be configured to change its voltage state between alarming and non-alarming states, and to transmit the voltage state to the air conditioning systemor the central alarmvia an output line, not shown. According to this configuration example, even when the refrigerant leak detection systemis operated in a so-called “stand-alone” configuration, it can inform the air conditioning systemor central alarmwhether or not it is alarming, in other words, whether or not a refrigerant leak is occurring.

The refrigerant leak detection systemmay be configured with a backup power system instead of or in addition to the battery kit.

One shutoff devicemay be provided for one indoor unit, or one may be provided for a plurality of indoor units. In a configuration with one shutoff devicefor a plurality of indoor units, the shutoff deviceshould be closed when a refrigerant leak is detected from any one of the plurality of indoor units.

The air conditioning systemmay have a configuration in which the outdoor unitand the indoor unitare connected by three pipes and heat can be recovered and reused, referred to as a “heat recovery system,” or a configuration in which the outdoor unitand the indoor unitare connected by two pipes, referred to as a “heat pump system.

While embodiments of the present invention have been described above, these embodiments have been presented only for illustration purpose and are not intended to limit the scope of the invention herein. These inventive embodiments can be implemented in other various forms, and various omission, replacement, changes and so on can be performed without departing from the spirit of the present invention. These embodiments and variations are encompassed in the scope and spirit of the invention and are encompassed in the invention recited in claims and the scope of the equivalents.