Device and test method for evaluating the safety of an installation using hydrogen
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- PROMETHYS ENGINEERING
- Filing Date
- 2024-11-19
- Publication Date
- 2026-07-17
Abstract
Description
Title of the invention: Device and test method for evaluating the safety of an installation using hydrogen Technical field
[0001] The present invention relates to the field of safety equipment relating to the detection of a gas leak in an enclosure. It relates more particularly to a device configured to be deployed in an installation using or producing hydrogen, in order to test the leak detection efficiency of the safety system of the installation. STATE OF THE ART
[0002] The production and consumption of hydrogen in industry is considerable. In order to reduce the risks associated with the use of hydrogen, particularly in the event of a leak within the installation, safety systems comprising detection and ventilation functions are generally used. These systems typically comprise, for leak detection, one or more hydrogen detectors distributed throughout the enclosure or building housing the installation. The position of the detectors in the building is a first essential aspect of the effectiveness of the safety system. When a hydrogen leak is detected, the safety system generally aims to cut off the hydrogen source and / or ventilate the building. Ventilation of the building is a second essential aspect of the effectiveness of the safety system.
[0003] Hydrogen, which has a very low density compared to air, disperses in the upper parts of the building and can form pockets of extremely flammable gas. To minimize the risk of retaining residual gas pockets after ventilation, numerical simulations in fluid dynamics are generally carried out. The complexity of a real system is however difficult to reproduce. An experimental campaign is generally required to validate the absence of a hydrogen accumulation zone which could create an explosive atmosphere.
[0004] The document "Hydrogen dispersion in a closed environment, M. de Stefano et al, International Journal of Hydrogen Energy (2019)" presents experimental results on the dispersion of hydrogen in a closed volume. General, empirical rules can be deduced from this type of study. Here again, the specificities of a real installation must be taken into account in order to best position the hydrogen detectors and / or the ventilation system of the safety system.
[0005] Existing solutions do not allow for the actual effectiveness of a safety system to be precisely assessed in the event of a hydrogen or gas leak within a given installation. An object of the present invention is to meet this need.
[0006] In particular, an object of the present invention is to provide a device and a test method for evaluating the effectiveness of a leak detection and / or ventilation system of a given installation. Another object of the invention is to provide a device and a test method for determining an optimal position of the gas detectors for a leak detection system within the enclosure of a given installation.
[0007] Other objects, features and advantages of the present invention will become apparent from a consideration of the following description and accompanying drawings. It is understood that other advantages may be incorporated. SUMMARY
[0008] To achieve this objective, according to one embodiment, a test device is provided for testing a security system of an installation comprising an enclosure, said security system comprising: • at least one sensor called a host sensor configured to detect a hydrogen leak in said enclosure, and • a mechanism intended to secure the installation, configured to be triggered in response to a detection of a hydrogen leak by the at least one host sensor.
[0009] The test device comprises: • a dispersion device configured to disperse gas in the enclosure, • at least one sensor called a guest sensor, independent of the security system, configured to measure a concentration [G]m of said gas in the enclosure, for example a concentration of helium [He]m or hydrogen, • a central unit comprising an acquisition module configured to process gas concentration measurements [G]m acquired by the at least one guest sensor.
[0010] Advantageously, the central unit of the test device comprises a control module configured to: • be connected to the facility's security system, and • trigger the safety system mechanism in response to a gas concentration [G]m, measured by at least one guest sensor in the enclosure, greater than a predefined threshold [G]crit.
[0011] Thus, the device according to the invention makes it possible to simulate the entirety of a gas leak scenario in the particular environment of the installation. Helium, which has dispersion properties similar to those of hydrogen without being flammable, is preferably used for safety reasons.
[0012] The dispersion device simulates the source of the gas leak. This dispersion device can advantageously be moved to different locations in the enclosure, typically to the most at-risk locations in the installation, for example at circuit connections. The gas flow rate of the dispersion device can be controlled. Different leak situations can thus be simulated.
[0013] The guest sensor(s) are typically used as a replacement for the host sensors. They may be placed at the host sensors to simulate the detection portion of the facility's security system. The existing detection mesh may be replicated. The guest sensors may also be deployed at other locations within the enclosure to track changes in gas concentration over time. A detection mesh different from the existing mesh may be created.
[0014] The central unit of the test device, which processes the gas concentration measurements acquired by the guest sensors, is advantageously configured to be interfaced with the safety system of the installation. In particular, it is configured to take partial control of the safety system in order to trigger the mechanism of the safety system when the gas concentration measured by the guest sensors becomes higher than the predefined critical threshold. This makes it possible to simulate the reaction of the safety system in the context of the leak scenario that has been chosen.
[0015] The evolution of the gas concentrations measured by the guest sensors can be monitored via the central unit after triggering of the safety system mechanism, in order to evaluate the effectiveness of the safety system in limiting the consequences of the leak. This makes it possible to verify the proper functioning of the safety system, and to validate, if necessary, the compliance of the safety system with the safety standards in force. The test device according to the invention can thus be advantageously deployed in the context of certification of a safety system of a given installation. An overall evaluation of the safety system, for different leak scenarios in a given real installation, can be advantageously carried out by the test device according to the invention.
[0016] Another aspect of the invention relates to a testing method implementing this testing device. The method comprises: • placement of the dispersion device at the level of a potential source of gas leakage within the installation enclosure, • placement of the guest sensor(s) at least at the level of the host sensor(s), • a disconnection of the host sensor(s) from the security system of the installation to be tested, • a connection of the control module to the safety system of the installation to be tested, so as to control a triggering of the safety system mechanism, • triggering of the dispersion device so as to generate a gas leak within the installation enclosure, • an acquisition of gas concentration measurements from the guest sensor(s), as a function of time, • triggering of the safety system mechanism in response to a gas concentration [G]m measured by the guest sensor(s) above the predefined threshold [G]crit.
[0017] The test device and the test method can be advantageously deployed on different real installations. The analysis of the test results, according to the number of leak scenarios envisaged and / or the detection mesh set up, makes it possible to evaluate the effectiveness of the security system in a complete and detailed manner. The evaluation is carried out almost in real conditions. This makes it possible to avoid resorting to simplification hypotheses which are generally made in numerical models. Specific recommendations, directly linked to the specificities of the installation, can thus be established reliably. BRIEF DESCRIPTION OF THE FIGURES
[0018] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which:
[0019] [Fig.l] [Fig.l] schematically represents a test device according to an embodiment of the present invention.
[0020] [Fig.2] [Fig.2] corresponds to a flowchart of a part of a test method according to a particular embodiment of the present invention.
[0021] [Fig.3] [Fig.3] schematically illustrates a variation in helium concentration as a function of time when implementing the test method according to an embodiment of the present invention.
[0022] [Fig.4] [Fig.4] schematically illustrates variations in helium concentration as a function of time measured by different guest sensors placed in the installation during the implementation of the test method according to an embodiment of the present invention.
[0023] The drawings are given as examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily on the scale of practical applications. In particular the different modules and the different connections are illustrated by diagrams which are not representative of reality. DETAILED DESCRIPTION
[0024] Before beginning a detailed review of embodiments of the invention, optional features which may possibly be used in combination or alternatively are set out below:
[0025] According to one example, the at least one guest sensor has a response time tdet that is lower than the response time tinstau of the at least one host sensor. This allows for a wider operating range and / or more detailed analysis. It is also advantageous to have guest sensors capable of reproducing at least the same performance as the host sensors. The guest sensors can thus be used in place of different host sensors having varying performances, in different types of installations. The intrinsic performance of the guest sensors is not a limiting factor for testing different security systems.
[0026] According to one example, the at least one guest sensor has a response time tdet less than or equal to 500 ms, preferably less than or equal to 200 ms.
[0027] According to one example, the central unit comprises a parameterization module configured to parameterize the response time tdet + At of the at least one guest sensor, so as to reproduce the response time tinstau of the at least one host sensor. The guest sensors can advantageously be parameterized so as to reproduce the response time of the host sensors. This makes it possible to precisely simulate the detection part of the security system.
[0028] According to one example, the dispersed gas is helium or hydrogen.
[0029] According to one example, the central unit comprises a dispersion module configured to control the dispersion device. The control for leak generation, for leak detection and for triggering the mechanism of the safety system can thus be advantageously centralized at the central unit.
[0030] According to one example, the test device comprises a plurality of guest sensors, said plurality comprising at least two guest sensors, preferably at least ten guest sensors. The higher the number of guest sensors, the finer the detection mesh. This makes it possible to faithfully supplement all of the host sensors. This also makes it possible to add guest sensors dedicated to monitoring the evolution of gas concentrations at different secondary locations in the installation.
[0031] According to one example, the dispersion device, the at least one guest sensor and the central unit are configured to be arranged in a portable suitcase. The test device is advantageously portable or transportable. It can thus be easily deployed in different geographically distinct installations.
[0032] According to one example, the central unit comprises a monitoring module configured to monitor an operation of the mechanism of the security system. This additional function makes it possible to detect a possible failure of the mechanism of the security system, after triggering of the latter.
[0033] According to an example, the mechanism of the security system comprises a ventilation system and the monitoring module is configured to determine an operating state of said ventilation system. The monitoring module may for example comprise optical sensors detecting the rotation of the blades of a fan, or acoustic sensors detecting the vibrations of the fan, or electrical sensors measuring the electrical consumption of the fan, or mechanical sensors such as accelerometers or gyrometers. Other types of sensors may be envisaged to determine the operating state of the ventilation system.
[0034] According to one example, the testing method further comprises setting the response time tdet + At of the guest sensor(s) to reproduce the response time tinstau of the host sensor(s).
[0035] According to one example, the testing method further comprises determining an operating state of the mechanism of the security system.
[0036] According to one example, the mechanism of the security system comprises a ventilation system and the operating state of said ventilation system is determined via at least one of: an optical sensor, an acoustic sensor, an electrical sensor, a mechanical sensor.
[0037] According to one example, the testing method further comprises placing at least one so-called complementary guest sensor at a secondary location of the installation without a host sensor. This complementary guest sensor is typically dedicated solely to monitoring the evolution of the gas concentration at said secondary location.
[0038] According to one example, only the measurements of the guest sensor(s) placed at the host sensor(s) are taken into account for triggering the safety system mechanism, the measurements of the complementary guest sensor(s) being processed only to map the gas concentration in the installation, as a function of time. The complementary guest sensors make it possible to refine the detection mesh. It may appear at the end of a test that an additional host sensor is required at a secondary location of the installation, and / or that additional ventilation is required at this secondary location.
[0039] Unless incompatibility exists, technical features described in detail for a given embodiment may be combined with technical features described in the context of other embodiments described by way of example and not limitation. In particular, elements described or illustrated for certain embodiments of the test device and its method may be combined so as to form another embodiment which is not necessarily illustrated or described. Such an embodiment is obviously not excluded from the invention.
[0040] In the context of the present invention, the term "enclosure" means a closed or semi-closed enclosure housing at least one element for transporting, storing or producing gas, typically hydrogen. Such an enclosure may designate a building or a room in a building, or a container or an engine compartment. The terms "enclosure of an installation" are therefore not limited to particular size characteristics. The enclosure may be mobile or fixed. It may have a volume of a few cubic decimeters to several cubic meters. Different fields of application are envisaged, from industrial buildings using hydrogen to hydrogen vehicles, for example.
[0041] In the present invention, the sensors of the test device are the “guest” sensors. The sensors of the installation are the “host” sensors.
[0042] “Disconnection” of the host sensor(s) from the safety system of the installation means an action aimed at suppressing the triggering of the safety system by the host sensors. This disconnection may correspond to a power-down of the host sensors, or a software disconnection for example.
[0043] The mechanism intended to secure the installation may act physically on the installation, such as a stop valve or a fan, or may correspond to the emission of a signal, for example an alarm.
[0044] Gas concentrations, typically helium or hydrogen, can be measured relative to the surrounding air, for example in volume %.
[0045] The terms "substantially", "approximately", "of the order of" mean to within 10%, and preferably to within 5%. Furthermore, the terms "between ... and ..." and equivalents mean that the limits are included, unless otherwise stated.
[0046] In the following examples, the various functions of the test device are preferably partly centralized within the central unit. It is nevertheless perfectly possible to implement these functions differently, without departing from the general principle explained below. The various dispersion, parameterization, acquisition, control and monitoring modules can be arranged together or separately.
[0047] The original idea implemented in the context of the development of the present invention consists in particular in reproducing a real leak scenario via the test device, to observe the reaction of the safety system and record the evolution of the gas concentrations within the installation. This makes it possible to evaluate the effectiveness of the safety system of the installation in the face of a leak situation.
[0048] The test device therefore comprises at least one gas dispersion means for simulating the leak, gas sensors for measuring the local gas concentrations, and a central unit connected to the safety system and capable of triggering the mechanism of the safety system. In the following, the test device is described for an embodiment in which the gas is helium or hydrogen. Other gases are perfectly conceivable.
[0049] [Fig.l] schematically illustrates a test device D according to a particular embodiment of the invention. As indicated previously, this test device D is intended to test the effectiveness of the safety system of the installation in the event of a leak. Such a safety system typically comprises host sensors placed within the installation, and at least one mechanism intended to secure the installation.
[0050] The host sensors can deliver an analog signal proportional to the gas concentration (hydrogen or helium). They can alternatively be of the “all or nothing” type and send a constant signal beyond a detection threshold.
[0051] The safety mechanism may include a ventilation system for evacuating gases from the leak. It may also include one or more shut-off valves for isolating the leak. It is triggered when the host sensors transmit a detection signal corresponding to the detection of a gas concentration greater than the predefined threshold for the installation.
[0052] The test device D may in particular comprise: • A dispersion device 10. This device has the function of dispersing gas, in particular helium, according to a controlled flow rate at an orifice 111. The dispersion device 10 may be, for example, a gas cylinder and its pressure regulator. A flow controller connected to the gas cylinder may be added in order to regulate the gas flow rate. The orifice 111 may be formed by the end of a flexible pipe 110 connected to the gas cylinder. The flexible pipe 110 typically has a length of between a few tens of centimeters and a few meters. This makes it possible to place the orifice 111 as close as possible to the potential sources of leakage in the installation. The leak simulation is thus made more faithful to a real leak situation. In the diagram illustrated in [Fig.l], the dispersion device 10 is offset from the central unit 30. It can be connected to the central unit 30 by a cable 310, typically when the central unit 30 comprises a dispersion module 31 configured to control the triggering of the dispersion device 10 and / or the gas flow rate of the dispersion device 10. The dispersion device 10 can alternatively be integrated with the central unit 30 within a common housing. The length of flexible pipe 110 is then typically increased. Gas sensors 21, 22, 23, 24. These sensors 21, 22, 23, 24 are configured to measure a gas concentration, in particular a helium [He]m concentration. They are typically more efficient than the host sensors installed by default in the installation. The sensors 21, 22, 23, 24 have in particular a very short response time, for example of the order of 200 ms. Their sensitivity to helium is of the order of a few ppm, which ensures an excellent level of detection. They preferably also have excellent precision, with an uncertainty for example of less than 1%. The test device D is not limited by the performance of its sensors 21, 22, 23, 24. This offers increased detection possibilities with respect to the host sensors. The sensors 21, 22, 23, 24 are intended in particular to temporarily replace the host sensors during testing.According to one possibility, the performances of the sensors 21, 22, 23, 24 are adjusted so as to reproduce the performances of the host sensors. This makes it possible to precisely simulate the behavior of the host sensors in a leak detection situation. Some of the sensors 21, 22, 23, 24 can also be placed at locations in the installation without host sensors. This makes it possible to provide additional data during the test. The sensors 21, 22, 23, 24 are typically connected to an acquisition module 20. This acquisition module 20 receives the helium concentration measurements [He]m acquired by the sensors 21, 22, 23, 24. It records the measurements as a function of time and processes them, in particular by comparison with a critical threshold value [He]crit. This critical threshold value [He]crit is typically predefined according to a standard or a safety data sheet, or even a specificity of the installation.It can correspond to the detection threshold of the host sensors. The acquisition module 20 can be remote from the central unit 30 and connected by a cable 302, as illustrated in [Fig.l], or directly integrated with the central unit 30, for example within a common housing. The connection between the sensors 21, 22, 23, 24 and the . acquisition module 20 can be done wired, as illustrated by cables 201, 202, 203, 204 in [Fig.l], or wirelessly. • A central unit 30. The central unit 30 typically comprises at least one control module 33 intended to partially control the safety system of the installation. It notably comprises an electrical interface 330 with various connections, for example analog connections, “all or nothing” type connections, digital connections. The electrical interface 330 can comprise up to sixteen electrical contacts operating for example on current ranges between 4 mA and 20 mA, and / or voltage ranges between 0 V and 10 V, and configured according to different machine language architectures, for example according to the BUS, CAN (Controller Area Network), CANopen communication protocols. This makes it possible to connect the control module 33 of the central unit 30 to different safety systems. The test device D is advantageously versatile.When the central unit 30 is interfaced with the safety system of the installation, the control module 33 makes it possible in particular to trigger the mechanism of the safety system in response to a leak detection. The leak detection during the test is done via the sensors 21, 22, 23, 24 and the acquisition module 20. The control module 33 and the acquisition module 20 are connected so that a detection signal can be transmitted from the acquisition module 20 to the control module 33, so that the control module 33 can trigger the mechanism of the safety system. This detection signal is typically emitted when [He]m > [He]crit. .
[0053] The central unit 30 may also optionally comprise a dispersion module 31, a parameterization module 32, and / or a monitoring module 34.
[0054] The dispersion module 31 typically makes it possible to control the dispersion device 10. It can make it possible to trigger the opening and closing of the gas cylinder, and / or to regulate the gas flow rate directly at the central unit 30. It can be connected to the control module 33 so as to simulate the actuation of a gas cut-off valve by the safety system, typically by controlling the closing of the gas cylinder. It can be connected to the acquisition module 20, for example to send a leak start signal triggering the recording of the concentration measurements.
[0055] The parameterization module 32 advantageously makes it possible to adjust the response time of the sensors 21, 22, 23, 24 so that it is identical to the response time of the host sensors. This makes it possible to simulate more realistically the actual detection capabilities of the security system. The parameterization module 32 can be connected to the module control 33 so as to delay the triggering of the safety system mechanism.
[0056] The monitoring module 34 typically makes it possible to determine an operating state of the mechanism of the safety system, after it has been triggered. It can use different sensors, for example optical, acoustic, electrical sensors, to determine this operating state. When the mechanism of the safety system includes mechanical ventilation via fans, the optical sensor(s) can be used as counters of the number of revolutions of the rotating blades. The acoustic sensors can be used to measure the vibrations emitted by the fans. The electrical sensors can measure the electrical consumption of the fans. It is thus possible to determine an operating state of the fans. This function of monitoring the operation of the mechanism of the safety system makes it possible to quickly determine whether the latter is faulty or not.In the event of an inconclusive test, this allows a rapid decision to be made, in the analysis of the causes of failure, on the correct functioning of the safety system mechanism.
[0057] [Fig.2] shows a flowchart of a part of the test method according to a particular embodiment. In this method, the parameterization module 32 is used to delay the detection by the sensors of the test device. It is implemented so as to verify the following condition:
[0058] [Math.l] ^det + A / > tinstall
[0059] Where ^det is the time when the sensor of the test device detects a helium concentration [He]m greater than the threshold [He]crit. At corresponds to a time offset, and hnstail corresponds to the time when the sensor of the installation detects a helium concentration [He]m greater than the threshold [He]crit.
[0060] A time delay is introduced here so that the response time of the sensor of the test device simulates the response time of the sensor of the installation. This time delay function is typically a software function.
[0061] During initialization 320 of the parameterization module 32, the time offset A t is reset to zero. The response time tinstall is entered 321 in the parameterization module 32, and the test method can be launched.
[0062] When a sensor of the test device measures 120 a helium concentration [He]m greater than the threshold [He]crit after the response time het, the parameterization module 32 verifies 322 that the detection time tJa + A t is greater than or equal to the response time tinstall-
[0063] If this condition is verified, a detection signal is sent to the control module 33 to trigger 332 the mechanism of the safety system. If the condition is not verified, the parameterization module 32 increases 323 the time offset A / to adjust the detection time + A t with respect to the response time ^install- A feedback loop makes it possible to check and adjust the time offset so that the condition [Mathl] is verified.
[0064] Figure 3 schematically illustrates a variation in helium concentration as a function of time during the implementation of the test method. The helium leak is generated by the dispersion device at time tb. The helium concentration [He] in the installation increases progressively. One or more detectors of the test device measure a helium concentration reaching the critical threshold [He]crit at time 6 / ^. When the test device is configured to take into account the response time of the sensors of the installation, the triggering of the safety system mechanism occurs at time tdet + At. The helium concentration [He] continues to increase between het and At. After triggering of the safety system mechanism, the helium concentration [He] stabilizes and then decreases. The use of sensors in the test device that are more efficient than the sensors of the installation advantageously makes it possible to envisage several scenarios in the event of a leak.The timer function allows you to reproduce the behavior of the installation's sensors. This is the main test scenario. It allows you to evaluate the effectiveness of the security system as it is.
[0065] According to another scenario, the safety system mechanism is triggered at het, without a time delay. Early detection can influence the dynamics of the evolution of gas concentrations within the installation. This scenario can alert on the need to change the sensors of the installation for more efficient models, in particular with a shorter response time.
[0066] As illustrated in [Fig.4], several guest sensors are typically deployed within the facility. The variation in helium concentration measured by a given sensor typically depends on its location. In the test method, the sensors of the test device, called guest sensors, are placed at the level of the sensors of the facility, called host sensors. The host sensors are deactivated. The guest sensors placed at the level of the host sensors are those used for triggering the safety system mechanism. This makes it possible to reproduce the real situation of the facility. Other guest sensors can be added at other locations of the facility. These sensors are typically used for local monitoring of the helium concentration. This makes it possible to map the dispersion of helium within the facility according to a fine detection grid.
[0067] In [Fig.4], it is the sensors 21, 22 which record the curves C2i, C22 having the highest helium concentrations. These sensors 21, 22 are therefore preferred for controlling the triggering of the safety system mechanism. If these sensors 21, 22 are located in locations already occupied by host sensors, the positioning of the host sensors is correct. If these sensors 21, 22 have been placed in locations without host sensors, it appears that the host sensors have not been correctly positioned. This alerts the need to provide host sensors at these locations.
[0068] Through the examples previously described, it appears clearly that the test device and the test method according to the invention make it possible to reliably and precisely evaluate the effectiveness of the safety system of an installation when a leak occurs. They also make it possible to provide an enriched analysis within the framework of different previously established scenarios. The invention is not limited to the embodiments previously described. Other scenarios can also be envisaged, by implementing the test device according to the present invention.
Claims
Claims
1. Test device (D) intended to test a safety system of an installation comprising an enclosure, said safety system comprising: • at least one sensor called a host sensor configured to detect a gas leak in said enclosure, and • a mechanism intended to secure the installation, configured to be triggered in response to a gas leak detection by the at least one host sensor, the test device (D) comprising: • a dispersion device (10) configured to disperse gas in the enclosure of the installation, • at least one sensor (21, 22, 23, 24) called a guest sensor, independent of the safety system, configured to measure a concentration [G]m of said gas in the enclosure, • a central unit (30) comprising an acquisition module (20) configured to process gas concentration measurements [G]m acquired by the at least one guest sensor (21, 22, 23, 24),the test device (D) being characterized in that the central unit (30) comprises a control module (33) configured to • be connected to the safety system of the installation, and • trigger the mechanism of the safety system in response to a gas concentration [G]m, measured by the at least one guest sensor in the enclosure, greater than a predefined threshold [G]crit.,
2. Device (D) according to the preceding claim in which the at least one guest sensor (21, 22, 23, 24) has a response time tdet less than the response time tinstau of the at least one host sensor.
3. Device (D) according to the preceding claim in which the at least one guest sensor (21, 22, 23, 24) has a response time tdet less than or equal to 500 ms, preferably less than or equal to 200
4. ms. Device (D) according to any one of the two preceding claims in which the central unit (30) comprises a module parameter setting (32) configured to parameterize the response time tdet + At of the at least one guest sensor (21, 22, 23, 24), so as to reproduce the response time tinstau of the at least one host sensor.
5. Device (D) according to any one of the preceding claims in which the dispersed gas is helium or hydrogen.
6. Device (D) according to any one of the preceding claims wherein the central unit (30) comprises a dispersion module (31) configured to control the dispersion device (10).
7. Device (D) according to any one of the preceding claims comprising a plurality of guest sensors (21, 22, 23, 24), said plurality comprising at least two guest sensors, preferably at least ten guest sensors.
8. Device (D) according to any one of the preceding claims wherein the dispersion device (10), the at least one guest sensor (21, 22, 23, 24) and the central unit (30) are configured to be arranged in a portable suitcase.
9. Device (D) according to any one of the preceding claims wherein the central unit (30) comprises a monitoring module (34) configured to monitor an operation of the mechanism of the security system.
10. Device (D) according to the preceding claim in which the mechanism of the security system comprises a ventilation system and in which the monitoring module (34) is configured to determine an operating state of said ventilation system.
11. Test method implementing a test device (D) according to any one of the preceding claims, said method comprising: • a placement of the dispersion device (10) at a potential source of gas leakage in the enclosure of the installation, • a placement of the guest sensor(s) (21, 22, 23, 24) at least at the level of the host sensor(s), • a disconnection of the host sensor(s) from the safety system of the installation to be tested, • a connection of the control module (33) to the safety system of the installation to be tested, so as to control a triggering of the mechanism of the safety system, • a triggering of the dispersion device (10) so as to generate a gas leak in the enclosure of the installation, • an acquisition of the gas concentration measurements coming from the guest sensor(s) (21, 22, 23, 24), as a function of time, • the triggering of the mechanism of the safety system in response to a gas concentration [G]m measured by the guest sensor(s) (21, 22, 23, 24) greater than the predefined threshold [G]crit.
12. Method according to the preceding claim further comprising a parameterization of the response time tdet + At of the guest sensor(s) (21, 22, 23, 24) to reproduce the response time tinstau of the host sensor(s).
13. A method according to any one of claims 11 to 12 further comprising determining an operating state of the safety system mechanism.
14. Method according to the preceding claim in which the mechanism of the security system comprises a ventilation system and in which the operating state of said ventilation system is determined by means of at least one of: an optical sensor, an acoustic sensor, an electrical sensor, a mechanical sensor.
15. Method according to any one of claims 11 to 14 further comprising a placement of at least one so-called complementary guest sensor at a secondary location of the installation devoid of a host sensor.
16. Method according to the preceding claim in which only the measurements of the guest sensor(s) (21, 22, 23, 24) placed at the host sensor(s) are taken into account for triggering the mechanism of the safety system, the measurements of the complementary guest sensor(s) being processed only to map the gas concentration in the installation, as a function of time.