Fire alarm signal management method, fire alarm signal detection and management device enabling the implementation of said method

Abstract

Method for managing fire alarm signals, device for detecting and managing fire alarm signals enabling the implementation of said method. The invention relates to a method for managing fire alarm signals originating from at least one fire detector configured to generate at least one fire alarm signal (S1) when overheating is detected, and a fault signal (S2) being generated when the fire detector malfunctions. According to the invention, the management method comprises a step for determining a transient duration between the end of the fire alarm signal (S1) and the beginning of the fault signal (S2), as well as a step for emitting an alarm signal (S3) when the transient duration is less than or equal to an alarm threshold duration. This solution makes it possible to reliably determine whether the end of the fire alarm signal (S1) results from the extinguishing of the fire or from a malfunction of the fire detector.The invention also relates to a device for implementing said method. Figure 5.

Description

Title of the invention: Method for managing fire alarm signals, device for detecting and managing fire alarm signals enabling the implementation of said method

[0001] This application relates to a method for managing fire alarm signals, to a device for detecting and managing fire alarm signals enabling the implementation of said method, and to an aircraft comprising said device.

[0002] According to an embodiment of the prior art visible in [Fig. 1], an aircraft 10 includes a fire alarm signal detection and management device 12 which comprises various fire detectors 14 configured to generate a fire alarm signal each, positioned in the main power units 16 and the auxiliary power unit 18 of the aircraft 10, and a processing system 20 configured to process the fire alarm signals and, depending on the signals received, emit an alarm signal transmitted to audible and / or visual alarms 22 located in the cockpit of the aircraft 10 or transcribed onto a display system located in the cockpit.

[0003] According to an embodiment visible in [Fig.2], a main power unit 16 comprises, among other things, a reactor core 16.1, a fan and a fan casing 16.2. The fire alarm signal detection and management device 12 comprises, at each main power unit 16, fire detectors 14.1 to 14.4 positioned for example at a compartment located around the reactor core 16.1 and a compartment located around the fan casing 16.2. In addition, the fire alarm signal detection and management system 12 includes a processing system 20, two detection channels 24.1, 24.2 configured to transmit fire alarm signals emitted by fire detectors 14.1 to 14.4 to the processing system 20, as well as various audible and visual alarms 22.1, 22.2. The presence of two detection channels 24.1, 24.2 allows the transmission of fire alarm signals to the processing system 20 even if one of them is damaged.

[0004] According to an operating mode shown in [Fig. 3], each fire detector 14 is configured to emit a fire alarm signal SI, via one of the detection channels 24.1, 24.2, which has a first reference value VL0 in the absence of fire and a first detection value Vi, i when the fire detector 14 detects overheating exceeding a threshold level. Each fire detector 14 is designed to operate during a fire for at least a minimum duration The operating time is approximately 5 minutes. Therefore, the fire alarm signal SI displays a value equal to the first detection value Vi.1 as long as the overheating detected by fire detector 14 is greater than or equal to the threshold level and fire detector 14 is functioning. When the overheating falls below the threshold level (corresponding to the end of the fire) or when fire detector 14 or its detection channel 24.1, 24.2 is no longer functioning, the fire alarm signal SI displays a value equal to the first reference value Vi.0, or fire detector 14 no longer transmits a fire alarm signal SI, which corresponds to a value of 0.

[0005] In addition, each fire detector 14 is associated with a fault detector 28.1 to 28.4 configured to emit a fault signal S2 which has a second reference value V2.0 when the fire detector 14 is functioning correctly and a second malfunction value V2.i when the fire detector 14 is malfunctioning.

[0006] According to one mode of operation, the processing system 20 is configured to receive the fire alarm signals from each detection channel 24.1, 24.2 and combine them logically in order to emit an alarm signal.

[0007] When a first engine fire occurs in a first main power unit, a first fire detector 14.x among the fire detectors 14.1 to 14.4 detects abnormal overheating and emits a fire alarm signal SI with a value equal to the first detection value Vi j. If this first fire lasts more than five minutes, the first fire detector 14.x may be damaged. In this case, the fault detector 28.x associated with the first fire detector 14.x emits a fault signal S2 with a value equal to the second malfunction value V2 ,i.

[0008] Insofar as the first fire detector 14.x is no longer functioning, the crew of the aircraft 10 no longer has reliable and direct information to determine whether the first fire persists or whether a second fire has reignited after the first fire has been extinguished.

[0009] The crew may attempt to verify whether the main power unit 16 is on fire by viewing it through a cockpit or passenger cabin window. However, this visual check is not always possible or reliable.

[0010] Information relating to the parameters of the main and auxiliary power units 16, 18 available in the cockpit can help the pilot determine whether the fire is still burning or whether a new fire has started. However, this information is scattered throughout the cockpit and is not easy to interpret.

[0011] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0012] To this end, the invention relates to a method for managing fire alarm signals from at least one fire detector configured to generate at least one fire alarm signal when overheating is detected, a fault signal being generated when the fire detector malfunctions; the fire alarm signal having an end, the fault signal having a beginning.

[0013] According to the invention, the management method includes a step of determining a transient duration between the end of the fire alarm signal and the beginning of the fault signal, a step of comparing the transient duration and an alert threshold duration, and a step of emitting an alert signal when the transient duration is less than or equal to the alert threshold duration.

[0014] Determining a transitional time between the end of the fire alarm signal emitted by a fire detector and the beginning of the fault signal associated with that fire detector, and comparing it to a threshold alert time, makes it possible to determine reliably and objectively whether the end of the fire alarm signal results from the extinguishing of the fire or from the malfunction of the fire detector.

[0015] According to another characteristic, the alert threshold duration is less than or equal to one minute.

[0016] According to another feature, the management process includes, beforehand, a step of determining an operating time of the fire alarm signal as well as a step of triggering the steps of determining the transient time, comparing the transient time and the alert threshold time then, depending on the comparison step, a step of issuing an alert signal if the operating time of the fire alarm signal is greater than or equal to an operating threshold time.

[0017] According to another characteristic, the fire detector has a minimum operating time. In addition, the threshold operating time is between 60% and 90% of the minimum operating time of the fire detector.

[0018] According to another feature, the management process includes a step of triggering a visual and / or audible alarm or of transcribing onto a display system when the alert signal is emitted.

[0019] The invention also relates to a device for detecting and managing fire alarm signals, enabling the implementation of a method for managing fire alarm signals according to one of the preceding characteristics.

[0020] According to the invention, the device comprises at least one fire detector configured to generate at least one fire alarm signal when overheating is detected, and at least one processing system configured to process each alarm signal. fire alarm system, and, for at least the fire detector, a malfunction detection system configured to issue a fault signal when the fire detector malfunctions; the fire alarm signal having an end point, the fault signal having a beginning point. Additionally, the processing system is configured to compare an alert threshold duration and a transient duration between the end of the fire alarm signal and the beginning of the fault signal, and to issue an alert signal if the transient duration is less than the alert threshold duration.

[0021] According to another characteristic, the alert threshold duration is less than or equal to one minute.

[0022] According to another feature, the processing system is configured to determine an operating time of the fire alarm signal of the fire detector and, if the operating time of the fire alarm signal is greater than or equal to an operating threshold time, to trigger steps of determining the transient time, comparing the transient time with the alert threshold time and, depending on the comparison step, issuing an alert signal.

[0023] According to another characteristic, the fire detector has a minimum operating time. In addition, the threshold operating time is between 60 and 90% of the minimum operating time of the fire detector.

[0024] According to another feature, the processing system is configured to execute a program which includes the following instructions: a. Determining the operating time of the fire detector, b. comparison of the determined operating time with a threshold operating time associated with the fire detector, c. If the operating time is greater than or equal to the threshold operating time, then the program continues; otherwise, it is stopped. d. determination of a transitional period between the end of the fire alarm signal emitted by the fire detector and the beginning of the fault signal associated with that fire detector, e. if the transient duration is less than the alert threshold duration then an alert signal is issued, otherwise the program is stopped.

[0025] The invention also relates to an aircraft comprising a device for detecting and managing fire alarm signals according to one of the preceding characteristics.

[0026] Other features and advantages will become apparent from the following description of the invention, given by way of example only, with reference to the accompanying drawings, among which:

[0027] [Fig. 1] is a perspective view of an aircraft,

[0028] [Fig.2] is a schematic representation of a main power unit and of a motor fire detection and extinguishing device illustrating an embodiment of the prior art,

[0029] [Fig.3] is a schematic representation of fire alarm and fault signals illustrating a method of realizing earlier art,

[0030] [Fig.4] is a schematic representation of a detection and management device fire alarm signals illustrating one embodiment of the invention,

[0031] [Fig.5] is a schematic representation of fire alarm, fault and an alert illustrating one embodiment of the invention.

[0032] According to an embodiment shown in [Fig. 4], a fire alarm signal detection and management device 30 comprises at least one fire detector 32 configured to generate at least one fire alarm signal SI when overheating (caused by a fire, for example) is detected, and at least one processing system 34 configured to process each fire alarm signal SI and, depending on the signal(s) received, emit an alarm signal Sa. This alarm signal is transmitted to audible and / or visual alarms 36 and / or displayed on a display system 36'.

[0033] The fire alarm signal detection and management device 30 includes, for each fire detector 32, at least one detection channel 38.1 linking the fire detector 32 to the processing system 34.

[0034] According to a configuration visible in [Fig.4], for each detection zone, the fire detection and alarm management device 30 comprises two fire detectors 32, 32' connected to the processing system 34 by two detection channels 38.1, 38.2, one for each fire detector 32, 32'. According to this configuration, each pair of fire detector 32, 32' and detection channel 38.1, 38.2 is doubled.

[0035] Of course, the invention is not limited to this configuration. According to another configuration, each fire detector 32 could be connected to the processing system 34 by two detection channels 38.1, 38.2

[0036] According to one mode of operation, the fire alarm signal SI has a first reference value VL0 (possibly zero) in the absence of fire and a first detection value Vi ,i when the fire detector 32 detects a temperature greater than or equal to a threshold level.

[0037] Each fire detector 32 is designed to operate for at least a minimum operating time in the event of a fire, on the order of 5 minutes. This minimum operating time is guaranteed by the manufacturer of the fire detector 32. In practice, the fire detector 32 may have an operating time exceeding the minimum operating time.

[0038] According to one embodiment, the fire alarm signal SI displays a value equal to the first detection value Vu as long as the temperature detected by the fire detector 32 is greater than or equal to the threshold level and the fire detector 32 is functioning. When the temperature falls below the threshold level (corresponding to the end of the fire) or when it is no longer functioning, the fire alarm signal Sla displays a value equal to the first reference value Vi.o or the fire detector 32 no longer transmits a fire alarm signal SI.

[0039] In operation, the fire alarm signal SI has a start at a first trigger instant ID1, in particular when the value of the fire alarm signal SI changes from the first reference value VL0 to the first detection value Vi,i, and an end at an end instant IF, in particular when the value of the fire alarm signal SI changes from the first detection value Vi,i to the first reference value V L0.

[0040] The processing system 34 is configured to execute a program. According to one operating mode, this program is configured to logically combine the warning signals from the detection channels 38.1, 38.2 and generate an alarm signal Sa if at least one of the fire alarm signals SI is equal to the reference value VL0.

[0041] The fire alarm signal detection and management device 30 includes, for at least one fire detector 32, a malfunction detection system 40 configured to emit a fault signal S2 when the fire detector 32 is no longer functioning or is not functioning correctly. Depending on one operating mode, this fault signal S2 has a second reference value V2.0 (possibly zero) when the fire detector 32 is functioning correctly and a second detection value V2j when the fire detector 32 is malfunctioning. During operation, the fault signal S2 has a start at a second trigger instant ID2, in particular when the fault signal S2 changes from the second reference value V2.0 to the second detection value V2i.

[0042] According to a first embodiment, a malfunction detection system 40 is integrated into the fire detector 32. In this case, the fire detector 32 is configured to emit the fault signal S2 when it malfunctions.

[0043] According to a second embodiment, the malfunction detection system 40 and the fire detector 32 are two separate elements. In this case, the malfunction detection system 40 may include, for each fire detector 32, at least one configured fault detector to generate a fault signal S2 when the associated fire detector 32 malfunctions.

[0044] Regardless of the embodiment, a fault signal S2 is generated when the fire detector 32 malfunctions. This fault signal S2 can be displayed on a display system.

[0045] Generally, the fire alarm signal detection and management device 30 comprises several fire detectors 32, 32' located in different areas, a processing system 34, detection channels 38.1, 38.2, each of them linking one of the fire detectors 32 to the processing system 34, as well as at least one malfunction determination system 40.

[0046] The fire detectors 32, 32', the processing system 34, the alarms 36, 36', the detection channels 38.1, 38.2 and the system for determining a malfunction 40 are not further described as they may be identical to those of the prior art.

[0047] According to a particular feature of the invention, a method for managing fire alarm signals includes a step of determining a transient duration DT between the end IF of the fire alarm signal SI and the beginning ID2 of the fault signal S2, a step of comparing the transient duration DT and an alert threshold duration, and a step of emitting an alert signal S3 when the transient duration DT is less than or equal to the alert threshold duration.

[0048] The step of determining the transient duration consists of determining the end time IF of the fire alarm signal SI, in particular when its value changes from the first detection value Vi,i to the first reference value V10, as well as the second triggering time ID2, in particular when the fault signal S2 changes from the second reference value V2.0 to the second detection value V2 i, and then determining the duration between the two times IF and ID2 which corresponds to the transient duration DT.

[0049] According to one embodiment, the alert threshold duration is less than or equal to one minute, preferably less than or equal to 30 seconds.

[0050] According to a configuration, the alert signal S3 has a third reference value V30 (possibly zero) when all fire alarm signals SI are inactive and / or when the transient duration is greater than the alert threshold duration and a third detection value V3 i, different from my third reference value V30, in particular when the transient duration DT is less than or equal to the alert threshold duration.

[0051] According to one embodiment, the fire alarm signal management method includes a step of triggering a visual and / or audible alarm or of transcription on a display system when the alert signal S3 has a value different from the third reference value V3 0 and presents the third detection value V3 j.

[0052] According to one mode of operation, the fire alarm signal management process includes, firstly, a step of determining an operating time of the fire alarm signal SI when the latter has a value equal to the first detection value Vi .1 and, if the operating time of the fire alarm signal SI is long, namely if this operating time is greater than or equal to an operating threshold time, a step of triggering the steps of determining the transient time DT from the end times IF of the fire alarm signal SI and the start times ID2 of the fault signal S2, of comparing the transient time DT and the alert threshold time and then, depending on the comparison step, a step of emitting an alert signal S3.

[0053] Depending on a configuration, for a given fire detector, the threshold operating time is greater than 60%, preferably between 60 and 90% of the minimum operating time. Thus, the operating time of the fire alarm signal SI is considered long if the operating time of the fire alarm signal SI is greater than 60% of the minimum operating time of the fire detector 32.

[0054] According to one embodiment, the processing system 34 is configured to compare an alert threshold duration and a transient duration DT and then issue an alert signal if the transient duration DT is less than the alert threshold duration.

[0055] According to one configuration, the processing system 34 is also configured to determine the transient duration DT and an operating time of the fire alarm signal SI of the fire detector 32 as well as to compare the operating time with a threshold operating time.

[0056] According to one embodiment, the processing system 34 is configured to execute a program which includes the following instructions: a. Determination of the operating time of fire detector 32, b. Comparison of the determined operating time with a threshold operating time associated with fire detector 32. c. If the operating time is greater than or equal to the threshold operating time, then the program continues; otherwise, it is stopped. d. Determination of a transitional duration DT between the end IF of the fire alarm signal SI emitted by the fire detector 32 and the start ID2 of the fault signal S2 associated with this fire detector 32, e. If the transient duration DT is less than the alert threshold duration then an alert signal is issued, otherwise the program is stopped.

[0057] According to one application, an aircraft engine fire detection and suppression system comprises at least one fire alarm signal detection and management device 30. In this case, several fire detectors 32 are distributed throughout the aircraft's main and auxiliary power units. Of course, the invention is not limited to this application. Thus, it can be incorporated into any installations or vehicles equipped with a fire detection system.

[0058] Determining a transitional time between the end of the fire alarm signal SI emitted by a fire detector 32 and the beginning of the fault signal S2 associated with this fire detector 32, and comparing it to an alert threshold time, makes it possible to determine reliably and objectively whether the end of the fire alarm signal SI results from the extinguishing of the fire or from a malfunction of the fire detector 32. The fire alarm signal management method according to the invention makes it possible to give the crew clear and unambiguous information concerning the presence or absence of a fire, even in the case of a malfunction of the detection system caused by the fire.

Claims

Demands

1. A method for managing fire alarm signals from at least one fire detector (32) configured to generate at least one fire alarm signal (SI) when overheating is detected, a fault signal (S2) being generated when the fire detector (32) malfunctions, the fire alarm signal (SI) having an end (IF), the fault signal (S2) having a start (ID2); characterized in that the management method comprises a step of determining a transient duration (DT) between the end (IF) of the fire alarm signal (SI) and the start (ID2) of the fault signal (S2), a step of comparing the transient duration (DT) and an alert threshold duration, and a step of emitting an alarm signal (S3) when the transient duration (DT) is less than or equal to the alert threshold duration.

2. A method for managing fire alarm signals according to the preceding claim, characterized in that the alert threshold duration is less than or equal to one minute.

3. A method for managing fire alarm signals according to any one of the preceding claims, characterized in that the management method includes, prior to that, a step of determining an operating time of the fire alarm signal (SI) as well as a step of triggering the steps of determining the transient duration (DT), of comparing the transient duration (DT) and the alert threshold duration and then, depending on the comparison step, a step of emitting an alert signal (S3) if the operating time of the fire alarm signal (SI) is greater than or equal to an operating threshold duration.

4. A method for managing fire alarm signals according to the preceding claim, characterized in that the fire detector (32) has a minimum operating time and in that the threshold operating time is between 60 and 90% of the minimum operating time of the fire detector (32).

5. Fire alarm management method according to any one of the preceding claims, characterized in that the management method includes a step of triggering a visual and / or audible alarm or of transcribing onto a display system when the alarm signal (S3) is emitted.

6. A fire alarm signal detection and management device for implementing a fire alarm signal management method according to any one of the preceding claims, said device comprising at least one fire detector (32) configured to generate at least one fire alarm signal (SI) when overheating is detected, at least one processing system (34) configured to process each fire alarm signal (SI) and, for at least the fire detector (32), a malfunction detection system (40) configured to emit a fault signal (S2) when the fire detector (32) malfunctions, the fire alarm signal (SI) having an end (IF), the fault signal (S2) having a start (ID2);characterized in that the processing system (34) is configured to compare an alert threshold duration and a transient duration (DT) between the end (IF) of the fire alarm signal (SI) and the beginning (ID2) of the fault signal (S2) and to issue an alert signal (S3) if the transient duration (DT) is less than the alert threshold duration.;

7. Fire alarm signal detection and management device according to the preceding claim, characterized in that the alert threshold duration is less than or equal to one minute.

8. A fire alarm signal detection and management device according to any one of claims 6 to 7, characterized in that the processing system (34) is configured to determine an operating time of the fire alarm signal (SI) of the fire detector (32), and, if the operating time of the fire alarm signal (SI) is greater than or equal to an operating threshold time, trigger steps of determining the transient duration (DT), comparing the transient duration (DT) with the alert threshold time and, depending on the comparison step, emitting an alarm signal.

9. Fire alarm signal detection and management device according to the preceding claim, characterized in that the fire detector (32) has a minimum operating time and in that the threshold operating time is between 60 and 90% of the minimum operating time of the fire detector.

10. A fire alarm signal detection and management device according to any one of claims 8 to 9, characterized in that the system

11. processing unit (34) is configured to execute a program that includes the following instructions: a. determination of the operating time of the fire detector (32), b. comparison of the determined operating time with a threshold operating time associated with the fire detector (32), c. If the operating time is greater than or equal to the threshold operating time, then the program continues; otherwise, it is stopped. d. determination of a transitional duration between the end of the fire alarm signal (SI) emitted by the fire detector (32) and the beginning of the fault signal (S2) associated with this fire detector (32), e. if the transient duration is less than the alert threshold duration then an alert signal is issued, otherwise the program is stopped. Aircraft comprising a device for detecting and managing fire alarm signals according to any one of claims 6 to 10.

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