Versatile liquid leak detection and location system.

Abstract

Liquid leak detection system, comprising a control unit (8) and a plurality of linear sensors (500), each of said linear sensors (500) comprising at least one communication element comprising at least one electronic communication module (410) and at least one linear conductor connected together to form a communication bus, characterized in that the plurality of linear sensors is arranged so that the communication elements of said plurality of linear sensors form a first linear interrogation bus having two ends, said first linear interrogation bus being connected to the control unit by at least one of its ends (51, 52), and in that the control unit polls the plurality of linear sensors by emitting interrogation signals (E1, E2) and receiving response signals (R1, R2) by the two ends of said first linear interrogation bus.Figure for the abridged version: Fig. 4.

Description

Description of the invention: Multipurpose installation for detection and loca- liquid leak detection. Technical field The present invention relates to a liquid leak detection system. It also relates to a method for detecting liquid leaks. State of the prior art To detect liquid leaks, over long lengths such as oil or water pipelines or over large areas such as industrial premises or computer rooms, it is known to install linear sensors connected together in series to form a detection line. In such a detection line, each sensor comprises an elongated portion which includes over all or part of its length a means sensitive to the liquid(s) to be detected. The sensors also comprise in their elongated portion a communication bus, which are connected together to form an interrogation bus running the entire length of the detection line. The end of the detection line is connected to a management unit. Such a detection line, in a version sensitive to hydrocarbons, is described in document EP3066443. Other detection modes are known, for example with sensitivity to conductive liquids such as water as described in documents FR2773613 and EP09306176. It remains desirable to improve this type of detectors and installations, particularly in terms of reliability, cost and performance, to enable them to cover larger, more varied areas, and to be more flexible in their implementation, maintenance, management or replacement. An objective of the invention is to overcome in whole or in part the disadvantages of the state of the art, in particular by improving their performance on these different points or the compromises between these different performances. Statement of the invention This objective is achieved with a liquid leak detection system, comprising a management unit and a plurality of linear sensors each comprising a first end and a second end and which are connected to each other in series. According to the invention, the plurality of linear sensors, connected to each other, form a linear interrogation bus having a first and a second end, said linear interrogation bus being connected to the management center by at least one of its ends. The management center is arranged for, at least one end of the linear interrogation bus: - sending at least one interrogation signal through the linear interrogation bus and receiving at least one response signal by the plurality of linear sensors via said end, communication between the linear interrogation bus and the management center is then two-way. The liquid leak detection system may comprise several control units, said control units being connected to each other via a wireless network (e.g. Wifi) or via a wired connection (e.g. Ethernet or Modbus). The advantage of this system is that communication between the linear interrogation bus and the central management unit is two-way. "Two-way" means that interrogation signals and response signals are received by the same end of said linear interrogation bus and this for both ends of said linear interrogation bus. The central management unit sends the interrogation signals to both ends of the linear interrogation bus one end after the other. In fact, the central management unit waits to receive the response signals from the first end of the linear interrogation bus to send the interrogation signals to the second end of the linear interrogation bus. Communication between the management center and the linear interrogation bus is advantageously carried out via a communication element included in each linear sensor. The communication element comprises at least one electronic communication module and one or more linear conductors, the linear sensors connected together forming a communication bus. The linear interrogation bus can also form a detection line which can be functionally connected to said management center directly or indirectly. The system may also include at least one accessory corresponding to a branch and / or a plug and / or a neutral cable. A "bypass" is an element that allows the addition of at least one second element, typically a linear sensor. A "stopper" is an end-of-line element indicating the end of a series wiring of linear sensors in order to distinguish it from a break or discontinuity in a linear sensor. A “neutral cable” means a cable that allows two remote sensors / derivations to be connected without adding functionality. An "element" means either a branch, a plug, or a neutral cable. Accessories are not limited to the list previously described. There are several types of derivation such as a straight derivation, a loop derivation and / or a length derivation. A "straight bypass" is a bypass that allows the addition of linear sensors and accessories in series without return. A "loop bypass" is a bypass that allows the addition of linear sensors and / or accessories in loop bypass (wiring with return to the bypass). A "length bypass" is a bypass that allows the addition of a linear sensor of non-predefined length in series without feedback. This accessory allows linear sensors of non-predefined length to be integrated into the system. The bypass then measures the length of the linear sensor. The bypass sends the information back to the control unit. These accessories allow you to create unique systems or networks adapted to the detection zone. The network can then be adapted according to your needs. The linear polling bus can be connected at both ends to the management center. The management center may also be arranged to compare at least a first series of response signals obtained by the first end of the linear interrogation bus with: a second series of response signals obtained by the second end of the linear polling bus, a list of data characterizing the plurality of linear sensors, said list being stored by said management center, the management center by deducing the presence or absence of a break in one of the linear sensors of the linear interrogation bus. The advantage of this system is then to define via the communication between the linear interrogation bus and the management center whether one of the linear sensors of said linear interrogation bus has a break or not. This break is identified by the management center by comparing the response signals received by each end of the linear interrogation bus. The response signals advantageously comprise a unique identifier enabling the management center to identify each sensor and / or accessory and consequently to determine which linear sensor is broken or not. The response signals may also comprise data characterizing each linear sensor and / or accessory. The management center may be arranged to compare a first series of response signals obtained comprising data from a first end of said linear interrogation bus and / or accessories with: - a list of data characterizing the plurality of linear sensors and / or accessories stored by said management center, and / or - a second series of response signals obtained by the second end of the linear interrogation bus comprising data characterizing said linear sensors and / or the accessories. A position of said break of one of the linear sensors of the linear interrogation bus can be defined by the management center if the latter deduces the presence of a break of one of the linear sensors of the linear interrogation bus based on the first and second series of response signals received. In fact, depending on the data included in a response signal sent by a linear sensor and / or a bypass to the management center, the management center is arranged to define the position of the break in the linear interrogation bus. The management center compares the response signals received by each end of the linear interrogation bus to define the position of the break. The system may also comprise at least two branches, the at least two branches being connected to the linear interrogation bus, a second linear interrogation bus being formed by a second plurality of linear sensors connected in series with each other, said second linear interrogation bus having a first and a second end and being connected to the at least two branches by its two ends. For each end of the second linear polling bus, each branch can be arranged to: - sending at least one interrogation signal through the second linear interrogation bus and receiving at least one response signal by the second plurality of linear sensors via said end, each branch also being arranged to transmit the at least one response signal received from the second plurality of linear sensors to the management center via the linear interrogation bus. The at least one response signal may also include data corresponding to the bypass or any other accessory present in the system. The number of branches is not limiting. Here, the linear interrogation bus is considered to correspond to a rank-one loop. When branches are integrated into this rank-one loop, the second linear interrogation bus connected to said branches forms a rank-two loop. Several rank-two loops can be integrated on a rank-one loop. Here, each branch plays the same role as the management center. The advantage of the bypass is that it is configured to transmit the data received from the higher-ranking loop(s) to the lower-ranking loop(s) or to the central management unit directly, as well as the data relating to it. The branch then sends the response signals from the second polling bus and its response signal through the linear polling bus, i.e. the rank-one loop, so that said response signals reach the end of the central management unit that sent the polling signal. A second-order loop can also be carried by a single linear sensor line which is connected and interrogated by only one of its ends by the management center. In the case of a single line, the management center does not perform a comparison of response signals to determine whether or not there is a break within this line. The management center is able to determine from which linear sensor there is a break, the response signals stopping at the last functional linear sensor. A "functional linear sensor" means a sensor that is powered from its first end to its second end without a break. A linear sensor with a break and / or break may be powered from only one end. In this case, the powered end can send a response signal in response to the interrogation signal. The user can then determine which linear sensor has suffered a break and / or break and / or damage, for example. The at least one accessory of the system can be arranged to transmit at least one response signal also comprising data specific to said accessory. Each linear sensor may include a liquid-sensitive sensing member, said sensing member having a change in resistivity when in contact with said liquid. For the detection of a conductive liquid, such as water / acid / base detection, the resistivity of the detection member decreases upon contact with the liquid. For the detection of a non-conductive liquid, such as a hydrocarbon or solvent, the resistivity of the detection member increases upon contact with the liquid. Linear return conductors can typically correspond to a measurement return wire and a continuity wire. The plurality of linear sensors of the linear interrogation bus may correspond to a plurality of linear sensors sensitive to conductive liquids and / or sensitive to non-conductive liquids and / or sensitive to hydrocarbons. The same applies to the second linear interrogation bus. Linear sensor types can be mixed depending on the installation area and the detection requirement. Depending on the data included in a response signal sent by a linear sensor and / or an accessory to the management center, the management center is arranged to define the position of the fluid detection by a linear sensor in the linear interrogation bus. The management center compares the response signals received by each end of the linear interrogation bus and / or by each accessory to define the position of the sensor in question. According to yet another aspect of the invention, there is provided a method for detecting liquid leaks in a system, the system comprising a management unit and a plurality of linear sensors each comprising a first end and a second end and which are connected together in series. According to the invention, the plurality of linear sensors, connected to each other, form a linear interrogation bus having a first and a second end, said linear interrogation bus being connected to the management center by at least one of its ends, for at least one end of the linear polling bus, the method comprising the following steps: - sending at least one interrogation signal through the linear interrogation bus and receiving at least one response signal by the plurality of linear sensors via said end, the communication of the first linear interrogation bus through the plurality of linear sensors then being two-way. The linear polling bus can be connected at both ends. The method may also include the following steps: - comparison by the management center of at least a first series of response signals obtained by the first end of the first linear interrogation bus with a second series of responses obtained from the plurality of linear sensors by the second end of the first linear polling bus, and / or, a list of data characterizing the plurality of linear sensors, said list being stored by said management center, - deduction by the management center of the presence or absence of a break in the first linear interrogation bus. The system may also comprise at least one accessory corresponding to a branch and / or a plug and / or a neutral cable, the method may also comprise the following steps: -comparison by the management center of at least a first series of response signals obtained comprising data from a first end of said linear interrogation bus and / or accessories with: a list of data characterizing the plurality of linear sensors and / or accessories stored by said management center, and / or a second series of response signals obtained by the second end of the linear interrogation bus comprising data characterizing said linear sensors and / or accessories. The method may also include the following step: - determination of a position of said break of one of the linear sensors of the linear interrogation bus by the management center if the latter deduces the presence of a break of one of the linear sensors of the linear interrogation bus as a function of the first and second series of response signals received. The system may also comprise at least two branches, the at least two branches being connected to the linear interrogation bus, a second linear interrogation bus being formed by a second plurality of linear sensors connected in series with each other, said second linear interrogation bus having a first and a second end and being connected to the at least two branches by its two ends, for each end of the second linear interrogation bus and for each branch, the method may comprise the following steps: - sending at least one interrogation signal through the second linear interrogation bus and receiving at least one response signal by the second plurality of linear sensors via said end, - transmission of the at least one response signal received from the second plurality of linear sensors to the management center via the linear interrogation bus. The method may also include the following step: - transmission of at least one response signal also comprising data specific to said accessory by said accessory. According to yet another aspect of the invention, there is provided a computer program product comprising instructions which, when the program is executed by a computer, cause the latter to implement the steps of the method according to the invention. Description of figures and embodiments Other advantages and particularities of the invention will appear on reading the detailed description of implementations and embodiments which are in no way limiting, and the following appended drawings: [Fig.1]: [Fig.1] is a symbolic diagram which illustrates an example of a detection element of a linear sensor which can be used in the context of the invention, here of the water / acid detection type; [Fig.2]: [Fig.2] is a symbolic diagram that illustrates an example of a sensor linear usable within the framework of the invention, and including a detection element of [Fig.1], of the same type or operating according to another detection mode; [Fig.3]: [Fig.3] is a symbolic diagram illustrating an example of a detection line, including the linear sensor of [Fig.2], here connected in a single line and without a downstream circuit: [Fig.4]: [Fig.4] is a symbolic diagram which illustrates a first exemplary embodiment of the invention, using for example linear sensors such as that of [Fig.2], forming a simple loop; [Fig.5]: [Fig.5] is a symbolic diagram illustrating a second exemplary embodiment of the invention, in which the loop of [Fig.4] comprises branch nodes which carry two secondary loops; [Fig.6]: [Fig.6] is a symbolic diagram which illustrates a third exemplary embodiment of the invention, in which the secondary loops of [Fig.5] themselves carry downstream circuits, comprising a loop of rank 3 and two simple lines of rank 3, one of which itself carries two loops of rank 4 downstream. [Fig.1] and [Fig.2] illustrate an example of the construction of a linear sensor that can be used within the framework of the invention. However, other types of linear sensors connected in series can be used within the scope of the invention, with all types of detection modes, and all types of communication and / or power supply buses. Different linear sensors can also be used together within the framework of the invention, provided that their communication buses are compatible with each other and with the management center. In this example, each linear sensor comprises a detector element 200, illustrated in [Fig. 1]. This detector element comprises an electronic management module 210, which is connected to the so-called proximal end of a detection member 208 elongated over the entire length of the linear sensor 500. This detection member 208 forms a bundle which comprises two metal conductors 106 and 110 and two detection conductors 114, which are electrically connected together at the opposite, so-called distal, end. This detector element is applicable in water / acid base detection for example. In other types of detection such as hydrocarbon detection for example, the detector element differs. As illustrated in [Fig.2], in addition to the detector element 200, the linear sensor 500 comprises a communication element which includes on the one hand at least one communication conductor 416 and two power supply conductors 424 running along the entire length of the linear sensor 500. At the end of the linear sensor 500, a connector 430 contains the electronic management module 210. It also comprises a communication module 410 and a power supply module 420, which are connected to the communication conductors 416 and power supply conductors 424 and together form a powered communication bus. This powered communication bus comprises two communication conductors 416 (one of the two being shown here in dotted lines and the other not being shown), each of which is used for communication in both directions. Each linear sensor 500 carries at its distal end a connector 440. This comprises connection ports 444 and 446 which make it possible to connect the distal end of its power supply conductors 424 and respectively communication conductors 416 to the proximal end of another linear sensor of the same type. The positions of the connectors 430 and 440 are not limiting. In certain embodiments, the connector 440 is positioned on the proximal end of the linear sensor 500 and the connector 430 on the distal end of the linear sensor 500 for example. According to Figures 2 and 3, in each linear sensor, the communication module 410 receives the interrogation signal from the management center positioned upstream, via a communication port 436 of its proximal connector 430. It then interrogates its management module 210 to determine the possible presence of a break. It returns this response signal upstream to the management center, and transmits an interrogation signal to the next linear sensor. When it receives a response signal from downstream from one of the following linear sensors, it transmits it upstream to the management center. The control unit thus interrogates all the sensors in the detection line, and receives their response signals through its communication port or interrogation port 51. As also illustrated in [Fig.3], several sensors 500(1) to 500(n) of this type can be connected in series to form a detection line LI. In this example, the detection line L1 is connected by its proximal end 430(1) to a communication port 51 of the management center 5, and receives at its distal end 440n a plug LIT. In this configuration, here called "single line", the management center 5 sends to all the linear sensors of the single line as well as to the accessories (here the plug), an interrogation signal, which is received by each communication module 410 of each proximal connector and by each accessory. If no break exists on the single line, all the linear sensors and accessories respond to the interrogation signal by sending a response signal to the management center. If a break exists on the single line, all the correctly powered linear sensors respond to the interrogation signal sent by the center. Indeed, if for example a break exists on the sensor 500(7), all the linear sensors positioned before said linear sensor 500(7) respond to the interrogation signal from the management center. If the sensor 500(7) is powered on its distal end 430(7), then said linear sensor 500(7) also responds to the interrogation signal. No response signal can be sent by the linear sensors following said linear sensor 500(7). The management center then determines that the break is located on the linear sensor 500(7). It should be noted that the linear sensors presented here as an example carry their electronic modules at one end. But their structure can also be different or even varied, for example with the electronics in the middle of the length, or at both ends. The detection conductors 114 are presented here as an example as being present along the entire length of the linear sensor, but it can also have a different or even varied shape or distribution, without departing from the scope of the invention. In [Fig.4] is illustrated a first example of an embodiment of the invention, in which a set of sensors 5001 to 5006 (here six as an example but this number is not limited) are connected together in series, to form a loop, here called a simple loop which is connected by its two ends 4301 and 4406 to the management center 8. This loop corresponds to a level one loop. This loop also forms a linear interrogation bus. This loop uses, for example, linear sensors such as the one in [Fig.2], without this being in any way limiting the types of linear sensors that can be implemented. The management center 8 carries a first interrogation port or communication port 81 and a second interrogation port or communication port 82. On the first interrogation port 81 is connected the first linear sensor 5001 of the linear interrogation bus, by means of its proximal connector 4301. The last linear sensor 5006 is connected by its distal connector 4406 to the second interrogation port 82. The first interrogation port 81 of the management center 8 interrogates all the linear sensors of the loop B1 by emitting a first interrogation signal El. It receives a first series of response signals R1 returned by all the linear sensors, in response to this first interrogation signal El. Once all the response signals are received by the interrogation port 81, the second interrogation port 82 of the management center 8 also interrogates all the sensors of the loop BI by emitting a second interrogation signal E2. It receives a second series of response signals R2 returned by all the linear sensors of the loop B1, in response to this interrogation signal E2. The interrogation signals E1, E2 and response signals R1, R2 are transmitted by each of the linear sensors of loop B1 independently of each other. Loop B1 is traversed by two interrogations / responses: on the one hand E1-R1, and on the other hand E2-R2. The management unit 8 then compares the response signals from both ends. In the case where no break or failure is present on the linear interrogation bus, the unit finds no difference when comparing the response signals. In the case where a break 900 or a failure occurs on one of the linear sensors (here 5002) of the linear interrogation bus, the linear sensor in question 5002 is capable of responding either upstream or downstream, the management module thereof remaining powered by the upstream or downstream of the loop (case of a single break). The first interrogation port 81 therefore receives a response signal from the linear sensors located upstream, here the response signal from the linear sensor 5001 and, if the linear sensor 5002 is powered by the upstream according to the direction of the interrogation El, the response signal from the linear sensor 5002. The following ones do not receive the first interrogation signal El, and cannot respond to it.Once all the response signals are received by the interrogation port 81, the second interrogation port 82 interrogates from the other end of the loop B1 the linear sensors of the linear interrogation bus, and receives the response signals from the linear sensors which are upstream of the break / failure 900 with respect to the direction of the interrogation signal E2. It therefore receives response signals from all the other linear sensors following 5006, 5005, 5004, and 5003 of this same loop BI. And if the linear sensor 5002 is powered from upstream according to the direction of interrogation E2, the response signal from the linear sensor 5002. The power bus is configured so that each module 4301 to 4306 is powered both from upstream and downstream. Thus, unlike the embodiment of [Fig.3], the management unit 8 which interrogates the linear interrogation bus which it sees downstream receives response signals from all the linear sensors still in working order. Furthermore, the dual interrogation bus E1-RI (solid arrows) and E2-R2 (hollow arrows) is organized so that the management unit 8 can identify the linear sensor at the origin of each response. For example, regardless of the interrogation signal E1 or E2 that the management unit receives, the communication modules of the linear sensors 5001 to 5006 are arranged to transmit their response signals with at least one identification data, which allows the control unit 8 to identify the sensor at the origin of each response. In the case of a break or failure, for example deduced by the management center 8 from the fact that it does not receive enough response signals or that it only receives one from each linear sensor instead of two, the management center 8 will identify which response signals arrive via each of its interrogation ports 81 and 82. In the example of the break 900 of [Fig. 4], the first interrogation port 81 receives the response signal from the first linear sensor 5001, if the linear sensor 5002 is supplied from upstream according to the direction of interrogation El, the response signal from linear sensor 5002. The second interrogation port 82 receives the response signals from linear sensors 5003 to 5006 and if linear sensor 5002 is supplied from upstream according to the direction of interrogation E2, the response signal from linear sensor 5002. The management unit 8 compares the response signals received by each interrogation port of the management unit and deduces that the faulty linear sensor is the linear sensor located between the last linear sensor of the first bus El-R] and the last linear sensor of the second bus E2-R2, and therefore that it is linear sensor 5002. In the event of multiple breaks or failures, the management unit 8 determines which portion of loop B1 is not responding on the same principle. In [Fig.5] a second exemplary embodiment of the invention is illustrated, which will only be described in its differences. In this example, the linear interrogation bus connected to the management center 8 by its two interrogation ports or communication ports 81, 82 comprises three branch type accessories B1N2, B1N3 and B1N6, which receive two secondary loops. These derivations B1N2, B1N3 and B1N6 are formed by an electronic derivation module, which is arranged to receive a connection from one or more other linear sensors, potentially of the same type but not necessarily. In this example, each of these leads are connected to one end of a linear sensor. Connector 4302 is thus connected to a B1N2 lead, connector 4303 to a B1N3 lead, and connector 4306 to a BIN6 lead. Within a linear sensor, each of the branch module(s) is operatively connected to the communication module 410, which transmits to it the interrogation signals E1, E2 that it receives, in addition to transmitting them to the adjacent linear sensor. The branch module is arranged to transmit the interrogation signal to a branch linear sensor via a branch box. Thus, the linear interrogation bus (called loop of rank one or loop B1) carries a so-called simple derivation B1N2, equipped with a derivation box 821 on which is connected one of the ends of a second linear interrogation bus (called loop of rank two or loop B2). The primary loop B1 also carries a second simple derivation B1N3, equipped with a second derivation box 822 on which is connected the second end of the secondary loop B2. Each derivation and / or accessory of the network sends a response signal comprising data specific to said derivation and / or accessory at the same time as the latter and / or the latter transfers the response signals from the second linear interrogation bus to the central management. Via this junction box 821, the junction module of the junction B1N2 relays in the form of first interrogation signals E21 in the loop B2, the first interrogation signals El received in the connector 4302 sent by the interrogation port 81. The junction B1N2 is also arranged to receive via its junction box 821 the response signals R21 sent by the linear sensors of the loop B2 in response to the interrogation signals E21, and to relay them in the primary loop B1 in the form of response signals R1. The response signals R21 are transmitted to the interrogation port 81 of the management unit which issued the interrogation signals. Via this junction box 822, the junction module of the junction B1N3 relays in the form of first interrogation signals E22 in the loop B2, the first interrogation signals E2 received in the connector 4303 sent by the interrogation port 82. The junction B1N3 is also arranged to receive via its junction box 822 the response signals R22 sent by the linear sensors of the loop B2 in response to the interrogation signals E22, and to relay them in the primary loop B1 in the form of response signals R2. The response signals R22 are transmitted to the interrogation port 82 of the management unit which issued the interrogation signals. This primary loop B1 also carries a third branch B1N6, called double. The latter operates in the same way as the single branches, except that it combines and manages both a first branch box 831 and a second branch box 832 to which the two ends of a second secondary loop B3 (itself also of rank two) are connected. Each of these branch boxes 831, 832 transmits first and second interrogation signals E31 and E32 to it, and receives first and second response signals R31 and R32 from it. As understood, the first and second junction boxes of said junction B1N6 of loop B1 are seen by loops B2, B3 in a similar manner to the interrogation ports 81, 82 of the management center 8. The branch B1N6 is therefore arranged to receive, via its branch box 831, the response signals R31 sent by the linear sensors of the loop B3 in response to the interrogation signals E31, and to pass them on to the primary loop B1 in the form of response signals RI. The response signals R31 are transmitted to the interrogation port 81 of the management unit which sent the interrogation signals. The B1N6 branch is also arranged to receive through its branch box 822 the response signals R32 sent by the linear sensors of the B3 loop in response to the E32 interrogation signals, and to pass them on to the primary B1 loop. in the form of response signals R1. The response signals R32 are transmitted to the polling port 82 of the management center which issued the polling signals. We see that it is thus possible to create numerous topologies, combining loops of different ranks, in a very flexible way, both with regard to the areas to be monitored and from the point of view of modifications to the installation during its lifetime. These advantages are obtained while benefiting from the redundancy and fault location that the individual operation of each loop allows, all the information of which ultimately goes back to the management center 8. Indeed, the detection of faults or breaks works on the principle presented in the embodiment of [Fig.4]. If a break is for example detected in the secondary loop B3, this is located via the responses to the various interrogations sent by the center 8. In [Fig.6] a third exemplary embodiment of the invention is illustrated, which will only be described in its differences. In this example, the secondary loop B2 itself carries another level three loop B22, called rank three, at a double branch node B2N4 and which operates in the same way with respect to its upstream loop B2 as the latter operates with respect to its own upstream loop B1. In addition, this secondary loop B2 carries, on a simple derivation B2N3, a detection line L21. This has the form of a simple line, terminated by a plug L21T, for example in a similar way to that of [Fig.3]. The other secondary loop B3 itself carries two detection lines L31 and L32, also called third-order. Detection line L32 is a single line including a plug L32T as shown in [Fig.3]. The other detection line L31 is also called a single line here because it is only connected to one branch port B3N3 of loop B3. At its downstream end, this single detection line L31 on loop B3, however, carries a double branch L31N4, to which the two ends of a loop B312 of rank four are connected, and which operates in a similar way to loops B3 and B22. This single detection line L31 of loop B3 also carries two single branches L31N2 and L31N3, to which another loop B311 is connected. As can be understood, each of the higher-ranking structures, whether loop or single line, receives the interrogation signals from its lower-ranking structure and transmits them to its still higher-ranking structure(s), and so on up to the lowest-ranking structures. In the opposite direction, it receives the corresponding response signals from its higher-ranking structure(s) and transmits them to its lower-ranking structure, and so on until these responses reach the central management 8. Note that the 'ranks' are defined here in increasing order from central management 8. In the case of a lower-rank structure formed by a single detection line, such as the single detection line L31 of rank three, its branches (single or double) are arranged to transmit to the higher-rank structure the interrogation signals in a split manner when they are connected to a loop, such as for example the double branch L31N4 which carries the loop B312 of rank four. Similarly, the single branches L31N2 and L31N3 are arranged to receive the interrogation signals which travel along the single detection line L31, and transmit it to the higher-rank structure in a split manner at both ends of the loop B311 of rank four. The detection of failures or breaks operates on the principle presented in the embodiment of [Fig.4]. If a break is detected, for example, in the secondary loop B3, this is located via the response signals in response to the various interrogation signals sent by the management center 8. Thus, we see that it is possible to vary the topologies even more, for example by mixing loops and single lines within the same installation managed by the same control unit. This makes it possible to better adapt the installation to the shape of the area to be monitored, and also to limit the costs and complexity of the installations. In [Fig.6], it will be noted that the management center 8 (in dotted lines) is formed by two sub-units 8A and 8B, each of which carries a first and second interrogation port or communication port 81, 82. These two sub-units are connected together and / or with a central unit 80, for example by a digital network of a known type, through which the two sub-units transmit their information and / or synchronizations. It is thus possible to produce a primary loop B1 whose two ends are more or less distant from each other, while maintaining the redundancy and fault location specific to the detection loop. Since these embodiments are in no way limiting, it is possible in particular to consider variants of the invention comprising only a selection of characteristics described or illustrated subsequently isolated from the other characteristics described or illustrated (even if this selection is isolated within a sentence comprising these other characteristics), if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection comprises at least one preferably functional characteristic without structural details, and / or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. Typically at least one of the means of the system according to the invention previously described, preferably each of the means of the system according to the invention previously described are technical means. Typically, each of the means of the system according to the invention previously described may comprise at least one computer, a central or computing unit, an analog electronic circuit (preferably dedicated), a digital electronic circuit (preferably dedicated), and / or a microprocessor (preferably dedicated), and / or software means. Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention. Of course, the various characteristics, forms, variants and embodiments of the invention can be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described above can be combined with each other.

Claims

Demands

1. Liquid leak detection system, including a central unit management (8) and a plurality of linear sensors (500) including each has a first end and a second end, and which are connected together in series, characterized in that the plurality of linear sensors (5001 to 5006), connected to each other, they form a linear polling bus presenting a first and a second end, the said interrogation bus linear being connected to the central management system by at least one of its ends (51, 52), and in that the central management system is arranged for, at least one end of the linear polling bus: - send at least one interrogation signal (E1, E2) through the bus linear interrogation and receive at least one response signal (RI1, R2) by the plurality of linear sensors (5001 to 5006) via said end, communication between the linear interrogation bus and the central unit management then being two-way.

2. System according to claim 1, characterized in that the bus The linear interrogation is connected at its two ends (51,52) to the central management.

3. System according to any one of the preceding claims, ca- characterized in that the system also includes at least one ac- accessory corresponding to a branch and / or a plug and / or a cable neutral.

4. System according to claim 2, characterized in that the central unit of management is also arranged to compare at least a first series of response signals obtained by the first end of the bus linear query with: a second series of response signals obtained by the second end of the linear polling bus, and / or, a list of data characterizing the plurality of sensors linear, the said list being stored by the said central unit management, the central management system by deducing the presence or absence of a disruption in a linear sensors of the linear polling bus.

5. A system according to any one of claims 3 to 4, characterized in what the central management system is set up to compare a first series of response signals obtained comprising data from a first end of said linear polling bus and / or ac- accessories with: - a list of data characterizing the plurality of linear sensors and / or accessories stored by said control unit, and / or - a second series of response signals obtained by the second end of the linear polling bus including characteristic data protecting said linear sensors and / or accessories.

6. System according to claim 4, characterized in that a position of said break in one of the linear sensors of the linear interrogation bus is defined by the central management system if it infers the presence of a failure of one of the linear sensors of the linear interrogation bus in function of the first and second series of response signals TEÇUES.

7. A system according to any one of claims 3 to 6, characterized in The system also includes at least two derivations. {(B1N2, B1N3, B1N6), the at least two derivations (B1N2, B1N3, B1N6) being connected to the linear polling bus, a second linear polling bus (B2, B3) being formed by a second plurality of linear sensors connected in series with each other, said second linear interrogation bus presenting a first and a second ex- terminals and being connected to at least two derivations (B1N2, B1N3, B1N6) by its two ends, for each end of the second linear polling bus, each The bypass is arranged to: - send at least one interrogation signal (E1, E2) through the second linear polling bus and receive at least one response signal (R1, R2) by the second plurality of linear sensors via said end, each branch also being arranged to transmit at least a response signal received from the second plurality of linear sensors at the central management unit (8) via the linear polling bus (B1).

8. A system according to any one of claims 2 to 7, characterized in that at least one accessory of the system is arranged to transmit at least one response signal also including its own data ancillary audit.

9. System according to any one of the preceding claims, ca- characterized in that each linear sensor comprises a member of liquid-sensitive detection (208), said detection member having a change in resistivity when it is in contact with said liquid.

10. System according to any one of the preceding claims, ca- characterized in that the plurality of linear sensors of the bus Linear interrogation corresponds to a plurality of linear sensors sensitive to conductive liquids and / or sensitive to non-conductive liquids drivers and / or those sensitive to hydrocarbons.

11. | Method for detecting liquid leaks in a system, the system including a control unit (8) and a plurality of sensors linear (500) each comprising a first end and a second end and which are connected together in series, characterized in that the plurality of linear sensors (5001 to 5006), connected to each other, they form a linear polling bus presenting a first and a second end, the said interrogation bus linear being connected to the central management system by at least one of its ends (51, 52), for at least one end of the linear polling bus, the process including the following steps: - sending at least one interrogation signal (El, E2) through the bus linear interrogation and reception of at least one response signal (R1, R2) by the plurality of linear sensors via said end, linear polling bus communication across the plurality of linear sensors are therefore bidirectional.

12. Method for detecting liquid leaks in a system according to the re- demand 11, characterized in that the linear polling bus is connected at its two ends (51, 52) to the control unit.

13. | Method according to claim 12, characterized in that the method also includes the following steps: -comparison by the central management system of at least a first series of response signals obtained by the first end of the bus linear query with: a second set of responses obtained from the plurality of linear sensors via the second end of the bus linear querying, and / or, a list of data characterizing the plurality of sensors linear, the said list being stored by the said central unit management, - deduction by the central management system of the presence or absence of a linear polling bus failure.

14. A method according to any one of claims 11 to 13, characterized in that the system also includes at least one accessory cor- corresponding to a branch and / or a plug and / or a neutral cable, the a process that also includes the following steps: -comparison by the central management system of at least a first series of response signals obtained including data from a first end of said linear polling bus and / or accessories with: a list of data characterizing the plurality of sensors linear and / or accessory data stored by said central unit management, and / or a second series of response signals obtained by the second end of the linear polling bus comprising data characterizing said linear sensors and / or the ac- CEessoires.

15. A method according to claim 13, characterized in that the method also includes the following step: - determination of the position of said rupture of one of the sensors linear of the linear interrogation bus by the management unit if This deduces the presence of a break in one of the linear sensors of the linear polling bus based on the first and second series of response signals received.

16. A method according to any one of claims 11 to 15, characterized in that the system also includes at least two de- derivations (B1N2, B1N3, B1N6). at least two derivations (B1N2, B1N3, B1N6) being connected to the linear polling bus, a second linear polling bus (B2, B3) being formed by a second plurality of linear sensors connected in series with each other, said second linear interrogation bus presenting a first and a second ends and being connected to at least two branches (B1N2, B1N3, B1N6) by its two ends, for each end of the second linear polling bus and for For each derivation, the process includes the following steps: - sending at least one interrogation signal (E1, E2) through the second linear polling bus and reception of at least one response signal (R1, R2) by the second plurality of linear sensors via said end, - transmission of at least one response signal received from the second plurality of linear sensors to the control unit (8) via the linear polling bus (B1).

17. | Product computer program comprising instructions which, when the program is executed by a computer, they drive it to implement the steps of the process according to any one of the re- demands 11 to 16