EP4042125A1

EP4042125A1 - Method for leakage detection

Info

Publication number: EP4042125A1
Application number: EP20792343.4A
Authority: EP
Inventors: Hermann Rosen
Original assignee: Rosen Swiss AG
Current assignee: Rosen 2 Holding Ag
Priority date: 2019-10-11
Filing date: 2020-10-12
Publication date: 2022-08-17
Also published as: CA3156834A1; US20230221206A1; DE102019127409A1; WO2021069735A1; JP2022552498A

Abstract

The invention relates to a method for leakage detection on an object flown through by a medium, in particular a pipe or a pipeline. According to the invention, a pattern is identified in the determined values for the change of the flow rate and the pressure of the medium and for a temperature change, and a probability for the presence of a leak is determined based on the identified pattern and due to self-learning systems.

Description

Leak detection method

The invention relates to a method for leak detection according to the preamble of claim 1 and a computer program product according to the preamble of claim 12.

If leaks occur in pipelines, it is often of great economic importance to identify, find and close the leak quickly and safely. Particularly in the case of pipeline systems, which - typically divided into pipeline segments - sometimes extend intercontinental and transport large quantities of potentially environmentally harmful products, such as crude oil, it is generally also of great ecological importance to quickly close a leak that occurs.

With known methods for leak detection, a mass flow balance is generally formed on the basis of the principle of mass conservation. In principle, the amount of a transported fluid that enters a pipe section should also exit completely again at the end of the pipe section, provided there is no leak in the section in question. Under idealized conditions, a disproportion between the inlet mass flow and the outlet mass flow indicates the presence of a leak.

However, the exact position of the leak along the relevant pipe section cannot easily be determined in this way. In addition, this idealized principle cannot be adequately transferred to real pipeline systems. The influence of various environmental factors is particularly problematic. Due to the sometimes considerable length of the pipelines or pipeline segments of several thousand kilometers, large pipelines, for example, often run through several climatic zones in sections. Above all, regionally different and also temporally changing temperatures along the pipeline represent, depending on the transported product, a sometimes considerable disturbance variable for the determination of a mass flow balance.

Due to the thermal expansion of the transported fluid, which depends on the individual product, the mass flow balance can be negative or even positive even without a leak being present. The pipeline's own volume ensures a certain buffer effect. If a pipeline runs through colder regions nen, the transported fluid will contract in these areas. Short-term local changes in the ambient temperature of the pipeline have a corresponding effect, for example due to precipitation or due to varying degrees of shielding of the ground from sunlight as a result of the cultivation and harvesting of fields in agricultural land use above the pipeline. If this effect is not taken into account when determining the mass flow balance, a loss of the transported fluid is registered although there is no leak.

From an economic point of view, it is almost impossible to completely monitor, for example, a pipeline network with a long total pipeline length and a complex branch structure with regard to all relevant factors. A leak that occurs is therefore rarely detected directly by sensors. Furthermore, as a rule, environmental factors and the thermodynamic properties of the medium cannot be recorded to a sufficient extent in order to be able to make exact statements about the correction of the mass flow balance determined for a measurement section. For this reason, various approaches are known to take into account or to compensate for fluctuations that occur through statistical treatment of determined data. This is intended to improve the identification of leaks under real conditions.

In order to take into account thermodynamic changes along the pipeline or the transported fluid, for example, the approach followed is to map occurring processes and relevant influencing factors using a real-time model. Corresponding methods are known for example under the name "Real Time Transient Model" (RTTM). In some cases, known methods also allow the leak to be located in a specific area, for example by detecting propagating pressure waves that occur when the leak occurs.

However, it is always a disadvantage here that the reliability of the results determined in a statistical manner is often low. This is especially true if only a comparatively small amount of data is available or a single measurement has to be evaluated. Due to the high economic, ecological and safety-relevant risk in the event of an incorrectly undetected leak, in case of doubt it is usually decided to carry out a manual inspection of the pipe section in question. It is not uncommon for a team of service technicians to have to advance long distances into impassable areas, for example to check an overland pipeline. It is understandably desirable worth avoiding the associated dangers for people and the environment and, in some cases, considerable costs.

Against this background, the object of the present invention is to improve the reliability of the leak detection on the basis of determined data.

The aforementioned object is achieved by a method according to claim 1 and by a computer program product according to claim 12. Advantageous further developments are each the subject of the dependent claims.

According to the proposed method, a series of values is first determined, which form the basis for the subsequent evaluation. The values include at least a change in the flow rate and a change in pressure of the product or medium transported through an object through which the flow passes, as well as a change in temperature value. Structurally, the through-flow object, which is in particular a pipe or a pipeline, is divided into one or more measurement sections. According to the method, a plurality of measuring points is now defined at each measuring section. Preferably, one measuring point each is arranged in the starting area and in the end area of the measuring section. At each of the measuring points, values are now determined for the aforementioned and, if applicable, for further physical quantities.

The desired values can be determined by direct and / or indirect measurement of the physical quantities. The highest possible resolution of the acquisition, in particular a temporal resolution, is advantageous here. As an alternative or in addition, however, data generated, in particular simulated, in a different way can also be used as a basis for the method according to the invention or assigned to a measuring point.

It goes without saying that according to the invention, as an alternative or in addition to determining an absolute value for the relevant variables, a relative value and the change in the corresponding variables can also be determined. The change over time, in particular, provides information about the dynamics of occurring processes and is therefore of greater importance in the context of the method than the mere absolute value of a variable.

Preferably, the assessment of whether or not there is an undesired loss of volume of the medium is essentially not based on static considerations Based on the current state. Rather, the method according to the invention is based in particular on the use of a dynamic model. For this reason, the change in the determined variables, in particular over time, is of great importance.

The change in the flow rate of the medium, i.e. H. of the fluid transported in the object through which the flow passes, is in particular related to mass, but can also be understood as related to volume. Furthermore, the change in pressure can relate to the hydrostatic and / or the dynamic pressure. The underlying temperature value or its change relates in particular to the ambient temperature at the measuring point, but can alternatively or additionally also directly reflect the change in the temperature of the medium at the measuring point. The detection of pressure and temperature changes is of comparatively great importance, since the flow of the medium usually changes strongly depending on an existing temperature and / or pressure gradient.

In addition to the physical quantities mentioned, values for other quantities can also be determined, for example for the flow velocity of the medium or its density or for the external ambient pressure in the area of a measuring point.

If actual measured values are not available or in too small a quantity, values for the desired quantities can be interpolated based on measured values from the adjacent or neighboring measuring points.

As an alternative or in addition to an actual measurement, the values at the measurement points can also be determined in particular by means of modeling. In particular, the flowed through object is modeled, preferably including the flowing medium. In this way, for example, the occurrence of certain values for the physical quantities of interest can be simulated, so that their effects on the object and / or the medium through which the flow is flowing can be determined using the underlying model.

Usually, both measured values and values determined by modeling or simulation can in principle be subject to an uncertainty, ie a random and / or systematic error. For this reason, statements can be made with the aid of the method according to the invention, in particular in the form of probabilities. Instead of or in addition to a real-time model, values can also be generated by means of forward modeling. For this purpose, an iterative method is used in particular, by means of which the values present at a measuring point and their effects are predicted. The number of iteration steps can in principle be selected according to the requirements placed on the accuracy of the calculation in the individual case.

In a preferred embodiment of the modeling used, a possible development of the overall system and / or individual parameters can be approximated, among other things, by determining conditional probability values. In this context, in particular methods of Bayesian statistics and / or estimation methods, such as a maximum likelihood approach, can be included.

In particular, determined, modeled and / or simulated data can be mapped in a simplified manner in a one-dimensional model of the object through which the flow passes, preferably a pipeline or a pipeline system. This can go hand in hand with a particularly selective reduction of data to a certain extent and / or take place through targeted aggregation of data. A weighting can also be used as a basis here in order to determine the extent to which the data used are included in the model or influence the modeled result. In general, a corresponding simplification towards a one-dimensional model allows the critical effects to be observed to be found in a significantly simplified and thus more reliable manner.

It goes without saying that a higher-dimensional model and / or a combination of several one-dimensional and / or higher-dimensional models can also be used in a comparable manner. In principle, the reproduction or utilization of the usually extensive, available data in the context of a largely simplified model is advantageous with regard to the method according to the invention. A correspondingly reduced representation of the current situation or its probable future development allows a user in particular a highly reliable detection or evaluation of irregularities with regard to the condition and / or the operation of a pipeline system. Which degree of simplification is sought in the result can be determined in each individual case, in particular depending on the specific application situation. Using a real-time model and / or a forward modeling of the state of the object under consideration, an optimal value for the spatial and / or temporal density of the measuring points for recording the data to be taken into account can preferably be determined. The measuring point density is in particular inhomogeneously distributed over the entire object under consideration or over a specific measuring section. By determining an optimal density, a sufficient amount of data can be collected locally and / or event-related in terms of time for the assessment of the current and / or future state, without generating an overhang of data volume through unnecessary redundant recording, whose transmission, storage and processing takes time. and is costly. If, for example, due to the particular need for a reliable assessment of potentially critical situations in high-risk areas, a higher density of measuring points is provided locally, the modeling allows an economically optimal level to be determined in each case, at which sufficient data is collected.

If values for the underlying physical quantities are determined at different measuring points of the measuring section, then according to the method at least one value group is formed from these values. The value group can ultimately comprise the total amount of the recorded or otherwise determined values or be formed by a subgroup of these values.

The determined values are fed to a data processing device for evaluation. The data processing device can be a computer present locally in the vicinity of the measuring section. Central processing of the data from different measuring points and / or measuring sections by a common data processing device is particularly preferred, however. The data processing device can also be a network of several interacting computers. In particular, it is preferred to provide the data processing device spatially remote from the measuring sections to be monitored, for example in a central computer center. The data processing can thus also take place, for example, according to the principle of a cloud service.

The value group is examined by means of the data processing device to determine whether the values of the value group form a pattern or whether a pattern is formed within the value group. Is by means of the data processing device a Identified pattern in the value group, a probability can be determined on the basis of the pattern, in particular on the basis of its type and the strength of its expression, with which a leak is present in the measurement section of the object flowed through. In this way, in particular, heuristic leak detection is possible, so that leaks occurring in the measurement section under consideration can also be detected if an evaluation of the existing data using known statistical methods does not provide reliable results.

In particular, the method according to the invention can be used to distinguish patterns from one another which, on the one hand, are based on a change in flow and / or a change in temperature of the medium due to environmental influences or which, on the other hand, are associated with an unwanted volume loss due to a leak or illegal removal. The aim here is to be able to react as quickly as possible to the respective situation in order to keep the loss of the transported medium as low as possible.

A classification algorithm is preferably applied to the value group or to a pattern identified in the value group. An existing pattern can thus not only be identified, but also evaluated with regard to the division into different pattern classes. The classes are particularly related to the relevance of the pattern with regard to the possible presence of a leak.

Alternatively or additionally, a pattern analysis algorithm can also be applied to the pattern, which - similar to a method for image recognition - interprets or interprets the pattern based on its nature, in particular to determine which event is represented by the pattern with which probability.

The data processing device is preferably designed accordingly in order to be able to execute such a classification algorithm and / or pattern analysis algorithm.

It is advisable to save the determined values as a data record in a database. Such a data record can in particular be formed by a value group, on the basis of which the evaluation with regard to a pattern identification is also carried out. Alternatively or additionally, it is preferred to store and / or such an identified pattern as a data record in a database Assign pattern to a previously or parallel saved data record. This allows such a pattern and / or the underlying values to be accessed again in a later analysis. In particular, a further analysis can be verified in this way.

If, during an evaluation of the values of a value group formed, a pattern is identified and one or more patterns are already stored in a database, the patterns can be compared with one another. A number of stored patterns in particular form a type of look-up table. A classification algorithm, which may be used, can preferably be used to determine with which of the stored patterns a newly identified pattern is to be compared. In the case of a sufficiently large amount of patterns stored in the database, which are preferably assigned to specific events, the present event can be identified quickly and reliably in this way according to the principle of a fingerprint comparison.

In addition to an overall pattern comparison, only individual characteristics of a specific pattern defined as characteristic can alternatively or additionally also be compared with a newly identified pattern. Here, the characteristic pattern serves as a criterion for the presence of a leak in the measurement section of the object through which the fluid flows. The characteristic pattern can be based, in particular, on averaged measured values that are related to the presence of a leak. In addition, generated, i. H. Data modeled and / or simulated by calculation can be used to generate the characteristic pattern. In this case, the characteristic pattern preferably corresponds to a pattern which ideally develops when there is a leak in the determined values. Depending on the degree of correspondence between the newly identified pattern and the characteristic pattern, the data processing device can be used to make a statement about the probability of a leak in the relevant measurement section. If a defined threshold value is exceeded, this can in particular be used as a hard criterion for the presence of a leak, so that appropriate measures, such as a manual check or an emergency shutdown, can be initiated.

A particularly preferred embodiment of the method according to the invention provides that, by means of the data processing device, a learning algorithm is applied to the determined values or to the value group formed from them becomes. With an adaptive algorithm, the method becomes more meaningful not only in the context of the current application, possibly with each iteration, as is already the case with current statistical methods. Rather, the learning algorithm is trained by every application and every processing of new data. Due to evolutionary effects, the reliability of such a self-learning system increases over time. This reduces the error rate in the identification and, in particular, the interpretation of patterns in the determined values.

Current statistical methods for data analysis with regard to leak detection are usually based on the compensation of occurring fluctuations in order to be able to read out the desired information from the appropriately adjusted data. The method according to the invention enables leak detection on the basis of the occurrence of corresponding patterns in the determined values even under conditions under which known methods fail, particularly if a self-learning algorithm is used as the basis for the data analysis. This can be the case, for example, if the underlying values have strong outliers, as a result of which approximations made in the statistical treatment fail. In contrast, the method according to the invention is based on the systematic application of empirical data to newly determined values. In particular, through the use of an adaptive algorithm, events can also be identified on the basis of the pattern developing in the values, which events are not recorded by the respectively rigidly applied statistical algorithms.

In a particularly preferred embodiment of the method, the values determined or the value group formed are evaluated using an artificial neural network. The data processing device is preferably designed accordingly for this purpose.

The learning algorithm is preferably trained before being used on the determined values or the value group with stored values that are related to real events, in particular the actual presence of a leak, or were recorded in this connection. As an alternative or in addition, the learning algorithm can also be trained on the basis of simulated values. Such simulated values have preferably been determined by simulating a leak on the object through which the fluid flows. By training in the aforementioned manner, the learning algorithm is trained to use certain value constellations or patterns in value groups with certain events To bring connection. It is thus possible after suitable training to identify a pattern in unknown or new values that is related to a certain type of event, in particular indicates the presence of a leak in the measurement section under consideration, by means of the adaptive algorithm by appropriate configuration of a query .

From a constructive point of view, it is preferred to determine the values used for the method according to the invention, in particular for the change in the flow rate of the medium, the pressure of the medium and / or the temperature, in each case non-invasively. This prevents a measuring device, such as a sensor, from being introduced into the interior of the object through which the flow passes, thereby influencing the flow of the medium in the interior. This would run the risk of the measurement itself and thus also the subsequent data evaluation being falsified. A corresponding measurement of the data is preferably carried out by means of a measuring device which is arranged on or in a shell of the object through which the flow passes, for example the wall of a pipeline. In the case of the flow rate, a so-called clamp-on flow meter is particularly suitable, which can detect the change in flow of the medium inside the object through which the flow is flowing from outside.

The measurement of the change in flow rate is particularly preferably carried out by means of an acoustic method. Here, the flow rate or its change is determined on the basis of the propagation behavior of external acoustic signals in the flowing medium. An ultrasound-based method has proven to be particularly suitable, in which the coupled acoustic signals have a correspondingly high frequency. In particular, the acoustic signals are coupled in contact-free, i. H. without a mechanical transducer acting from the outside on the wall of the object being flowed through.

The value group that is examined according to the method to identify a pattern is formed from the values determined at the measuring points, but is not necessarily limited to these values alone. In addition, further, in particular generally available, data can be included or added to the value group, for example with regard to the current and / or forecast weather in the vicinity of the object flowed through. Under certain circumstances, this can further increase the informative value of the results of the method according to the invention. In a preferred embodiment of the method, determined values of various measuring points are transmitted to a central data processing device. The transmission is preferably wireless.

The invention also includes a computer program product, by means of which a probability can be determined that there is a leak in an object through which a medium flows. The computer program product is designed in particular to carry out the method according to the invention for leak detection or for use in the context of the method according to the invention. It therefore includes instructions for recognizing a pattern in a group of values, the group of values being formed by values that are determined on a measurement section of the flowed object and at least relate to a change in the flow rate of the medium, a change in pressure of the medium and / or a change in temperature Respectively.

The invention is explained in more detail below on the basis of exemplary embodiments. All of the features described and / or shown in the drawings each form independent aspects of the invention, regardless of their combination in the exemplary embodiments or the references to the claims.

It shows

1 shows a schematic representation of an exemplary application of the method according to the invention,

2 shows a schematic representation of a further application of the method according to the invention and

3 shows a schematic illustration of the data processing in the method according to the invention.

1 shows a typical application situation for the method according to the invention. An object 1 with a flow through it in the form of a pipeline or a pipeline section for conveying a product in the form of an in particular fluid medium is laid in the outer area partly above ground and partly below ground.

The section shown represents a measuring section 2 of the considerably longer object 1 through which the air flows. The measuring section 2 is Appropriate leak detection procedures are monitored. For this purpose, a value for different physical parameters is determined at two measuring points 3.

In contrast to the two measurement points 3 shown, a larger number of measurement points 3 can also be assigned to a measurement section 2. In addition, although it is preferred, according to the invention, it is not absolutely necessary for the measuring points 3 to be arranged at the same positions along the measuring section 2 of the object 1 through which the fluid flows, for different physical quantities.

In general, the object 1 through which the flow passes is to be understood as an object which is basically provided for a medium to flow through. Within the scope of the invention it is in principle also possible to determine values for a measuring section 2 through which the medium does not flow continuously. A determination and / or prediction of environmental parameters, such as a change in the ambient temperature, can be of interest, for example, with regard to an imminent transport of the medium through the measuring section 2.

In principle, it is preferred for all relevant physical parameters to determine the corresponding values as non-invasively as possible, i. H. without the flowing medium being influenced by components introduced into the object 1 through which the flow passes, or the flow being otherwise disrupted.

A value for the change in the flow rate of the medium is determined. This is done in particular by a flow meter 4. In the example shown here, the preferred embodiment of the flow meter 4 is shown as a so-called clamp-on flow meter, which is applied from the outside to the object 1 through which the flow is flowing. The flow rate of the medium or its change can thus be determined non-invasively. It goes without saying that, in principle, any other type of flow measurement can also be useful for determining the value. The flow rate can be understood as related to the mass and / or the volume.

In the example shown, the flow meter 4 is based on an acoustic principle for measuring the change in flow rate of the medium. In this case, acoustic signals, in particular in the ultrasonic range, are introduced into the medium through the wall of the object 1 through which the flow passes, and their propagation speed is measured in order to draw conclusions about the flow properties of the medium. The coupling of the acoustic signal and / or the reading of the propagated signal is preferably carried out without contact, ie without one mechanical coupling of a transducer of the flow meter 4 to the wall of the object 1 through which the fluid flows.

Furthermore, a value for the pressure change of the medium is determined at each measuring point 3. The pressure change is measured in particular by a corresponding pressure sensor 5.

Furthermore, a temperature change is determined in particular by means of a temperature sensor 6. This is in particular a value for the ambient temperature or its change at the location of the measuring point 3. Alternatively or additionally, a value away from the measuring point 3, for example between two measuring points 3 of a measuring section 2, can also be recorded. In this context, such a value can be determined for the air temperature, the floor temperature, the temperature of the object 1 through which the flow passes or of the flowing medium itself. In particular, the influence of the ambient temperature on the medium in the object 1 flowing through along the route can thus be taken into account.

The values determined in particular by measurement for the named and possibly other physical parameters are transmitted to a data processing device 7 in order to be further evaluated subsequently. The transmission is preferably carried out wirelessly. It goes without saying that, as an alternative or in addition, wired transmission can also take place.

As indicated in the illustration in FIG. 1, the data processing device 7 can be a central data processing device 7 which is positioned at a location remote from the measuring section 2. The data processing device 7 can be designed as a single computer, but also as a network of several interacting computers. In addition, the data processing device 7 can also be designed as a complex system with several computing units operating in parallel and / or hierarchically linked.

The data transmission from the measuring points 3 to the data processing device 7 can in particular take place in accordance with common transmission standards, such as Bluetooth or WiFi, and / or via a cellular network. Satellite-based communication is also possible between the measuring points 3 or the devices for determining values provided at the measuring points 3, and the data processing device 7.

Furthermore, communication can take place between corresponding communication devices at the measuring points 3. This allows, for example, to provide a high-performance transmitter system only at one measuring point 3 or at least at a few measuring points 3 in order to transmit the determined values to the data processing device 7. The data at the individual measuring points 3 of the measuring section 2 are initially transmitted over comparatively short distances to such a central measuring point 3 and are transmitted from there to the data processing device 7. A corresponding structure can also be implemented by a separate relay station 10 that is not assigned to a specific measuring point 3, but is located in the vicinity of the relevant measuring section 2 and thus within range of the communication devices of all relevant measuring points 3.

A particular embodiment of the method is based at least essentially exclusively on data relating to the flow rate of the medium or its change. These data are preferably supplied by flow meters 4 and / or determined as part of a modeling.

Furthermore, a network of measuring points 3 or flow meters 4 is particularly preferably used, which extends at least over part of the object 1 through which there is flow or of the measuring section 2. Here, the individual measuring points 3 or flow meters 4 communicate preferably wirelessly with one another and / or with a data processing device 7, optionally using an interposed relay station 10. Alternatively or additionally, as in other embodiments of the method, use can also be made of conventional mobile radio technologies and / or a satellite-based communication may be provided.

As will be explained in more detail below, the transmitted data are evaluated within the scope of the method according to the invention by means of the data processing device 7 and examined for the presence of a pattern that indicates the presence of a leak 8 in the examined measuring section 2. If such a leak 8 is detected or if a sufficient probability of the presence of a leak 8 is determined, appropriate measures can be initiated in a short time to remedy the situation. In the illustration of FIG. 1, such a leak 8 is indicated in the subterranean section of the object 1 through which the flow passes. The transported medium, which can be petroleum, for example, penetrates uncontrollably into the ground 9 at the location of the leak 8 and can contaminate the groundwater there, for example. In addition to the economic importance of a loss of the transported medium, such a leak 8 can have serious ecological consequences. Extensive damage to the environment occurs not only in the case of catastrophic leaks 8, in which a large amount of the transported medium escapes in a short time. Rather, even small leaks 8, which only cause the medium to escape slowly over time, can already represent a great ecological danger.

In FIG. 2, a further application situation for the method according to the invention is shown by way of example. The object 1 through which the air flows is formed there by a comparatively complex pipe network. The section shown is intended to represent, purely symbolically, a widely branched network of pipelines, some of which are of great length. Apart from branched networks of supply lines, some of which span large distances between different regions of the world, a larger industrial plant, for example a refinery, can also have a comparatively complex pipe network. Various measurement sections 2 can be defined in such a strongly branched through-flow object 1. A measuring section 2 is not necessarily only defined by the distance of the object 1 through which the air flows between two measuring points 3, but can also include further areas in which, in particular, more than two measuring points 3 are provided. The definition of a measurement section 2 ultimately depends on the values obtained from which measurement points 3 or for which measurement points 3 determined values are used as the basis for the evaluation by the data processing device 7.

In the case of a correspondingly high branching complexity of the object 1 through which flow occurs, it can only be monitored directly with corresponding sensors with difficulty. Similar to a pipeline with a very long length, complete control of the system ultimately fails because of the costs that would arise for a corresponding number of sensors. In addition, the partial volumes that are in fluidic connection with one another result in interactions in the various branches of the object 1 through which flow occurs Buffer effects when the transported medium spreads in the pipe network. This also complicates the evaluation of a mass flow balance.

The method according to the invention has an advantageous effect here in that disturbance events, such as the occurrence of a leak 8, in a specific measurement section 2 are recognized by the identification of patterns in the determined values.

The influence of different temperatures on the behavior of the transported medium does not only occur when passing through different climatic zones or due to different weather conditions along a pipeline. In the example of an industrial plant, too, it usually happens that pipelines run along structures of different temperatures. For this reason, the temperature of the medium usually changes when it flows through the pipeline or the pipeline network. The associated expansion or contraction of the medium disrupts the collection of a mass flow balance considerably and makes it more difficult to detect an actual loss of mass, for example due to a leak 8 or due to illegal removal on the transport route.

In the method according to the invention, it is particularly taken into account in this context that various influencing factors usually affect the transported medium on different time scales, in particular the prevailing pressure and / or flow rate ratios. Changes in climatic or weather-related influences usually affect the medium in pipelines running underground, in particular, with a time delay, which is associated with a certain inertia in the reaction of the system. In contrast, intentional withdrawals of the medium, for example by end users, lead to short-term and above all locally occurring fluctuations, which must also be taken into account accordingly.

In particular, intentional but unplanned withdrawals of the medium in a measuring section 2, for example by end users, can be mapped by corresponding local consumption measurements and included in the method according to the invention. For this purpose, one or more measuring points 3, in particular having a flow meter 4, can be suitably positioned in the vicinity of the known extraction point.

The aim of the method according to the invention is to differentiate between patterns in the values determined, which are due to temperature and volume fluctuations of the Medium take place due to external and internal influences, of patterns that are related to the actual loss of the medium from the object 1 flowing through it on the transport route. The natural influences on the medium are diverse and therefore difficult to fully take into account within the framework of current statistical methods.

Any fluctuations that occur are primarily related to a temporal and spatial change in the temperature of the transported medium, in particular along the object 1 through which the air flows. Although this depends heavily on the ambient temperature, it is influenced by numerous other factors. Air and soil temperatures are dependent on solar radiation to different degrees and have a corresponding effect on the temperature of the medium. Rain and clouds, on the other hand, have a short-term cooling effect. In addition, especially in the case of underground pipelines, the biomass on the surface can have an effect on the temperature of the medium in the pipeline, for example in the form of an insulating effect or by shielding the ground from sunlight. This factor is also subject to short-term changes, for example through cultivation and harvesting on agricultural land.

In the case of a sufficiently extensive or correspondingly complex branched through object 1, such as a pipeline or a network of pipelines, thermodynamic changes in the flow properties of the transported medium usually also inevitably occur due to internal effects. The reasons for this are, for example, the fluctuation or change in the flow resistance due to the shape of the line. In particular, if the transported medium is composed of different substances, a change in the composition can also occur. This can also affect the flow behavior of the medium.

Large pipelines or pipe networks can also have a considerable intrinsic volume, which is first filled in so-called "line packing", ie when the line is charged with the medium and the operating pressure is built up, before the medium exits or is removed at a certain point becomes. A sufficiently large internal volume of the object 1 flowing through also leads to buffer effects during operation, through which volume-related changes in the medium can only be registered indirectly. Without further consideration of internal and / or external parameters, a Comparative measurement of the flow rate or its change at the inlet and at the outlet of a measuring section 2 of the object 1 through which the flow passes, hardly any meaningful conclusions can be drawn.

In extensive tests it was surprisingly found that different types of patterns can form in the determined values. In some cases, natural fluctuations cannot be completely eliminated using common statistical methods, even after the environmental parameters have been taken into account, but they do lead to patterns in the data. These differ from those patterns that can be observed in the event of an actual loss of mass, for example due to a leak 8, a line break or an illegal removal of medium on the transport route.

This is where the invention comes in by identifying and distinguishing between these two types of patterns. As already mentioned, according to the method, the data processing device 7 searches for a pattern in these values during or after the evaluation of the determined values for the change in the flow rate, the pressure and the temperature and possibly other physical variables.

The representation according to FIG. 3 illustrates the basic sequence in the evaluation of determined values by the data processing device 7 for leak detection. From the determined values, a value group 11 is first formed, which is analyzed by the data processing device 7 for the presence of a pattern. The value group 11 can include the entirety of the values determined at the measuring points 3 of a measuring section 2 or represent a subset thereof.

If a pattern is identified in the value group 11, the data processing device 7 can use this pattern to determine the probability of the presence of a leak 8 in the relevant measurement section 2 of the object 1 through which the flow occurs. The identification of such a pattern in the data of the value group 11 takes place in particular by a corresponding algorithm of a recognition routine, similar to the case of digital image recognition.

The data processing device 7 is preferably designed to execute a classification algorithm and applies such a classification algorithm to the value group 11 at. An identified pattern is thus classified with regard to its type, quality and / or characteristics.

As an alternative or in addition to such a classification algorithm, a pattern analysis algorithm can also be used by the data processing device 7 on the value group 11. With such a pattern analysis algorithm, the identified pattern can be interpreted with regard to its meaning. This allows a statement to be made as to which real event is represented by the pattern occurring in the determined values.

In a preferred embodiment, the data processing device 7 accesses a database in which an identified pattern can be stored as a data record 12. The same applies to the determined values or the value group 11. In particular, the identified pattern, the value group 11 and / or a specific real event, for example the presence of a leak 8, can be linked to one another and as data records 12 or as a common data record 12 stored in the database.

By comparing the pattern stored in the analyzed value group 11 with one or more patterns stored in data records 12 of the database, in the simplest case the identified pattern can be quickly assigned to an event group. Such a fingerprint-like comparison is possible in particular if the data processing device 7 has access to data records 12 which are classified with regard to the stored patterns and / or the associated events, and the characteristics of the identified pattern can be clearly assigned to one of these classes.

Alternatively or additionally, a characteristic or idealized pattern can also be used as a criterion, on the basis of which the probability of the presence of a leak 8 in the measurement section 2 under consideration is determined by a comparison with the pattern identified in the value group 11. Such a characteristic pattern can be based on measured values from one or more measurements in connection with a real event or else be based on simulated values.

If there is a sufficient degree of agreement between the identified pattern and the characteristic pattern, ie when a defined pattern is exceeded Threshold value, the criterion for the presence of a leak 8 can be assessed as fulfilled, so that appropriate measures can be initiated.

An embodiment of the method according to the invention is particularly preferred in which the data processing device 7 applies a learning algorithm to the determined values or the value group 11 in order to identify a pattern. Alternatively or additionally, an algorithm capable of learning can also be used to serve as a classification algorithm and / or as a pattern analysis algorithm. Compared to the previously described identification and evaluation of a pattern in the value group 11 according to essentially fixed criteria, a learning algorithm has the advantage that it becomes more efficient and reliable over time through appropriate training with suitable data. The susceptibility to errors with regard to the incorrect interpretation of a pattern as an indicator for a leak 8 (false positive) and with regard to the non-detection of an existing leak 8 on the basis of the determined values (false negative) thus decreases.

Such a learning algorithm is preferably trained by data sets 12 which are related to real events, in particular the presence of a leak 8, or which were measured when the relevant event occurred. Such data ultimately represent reality in the best possible way, so that the result of the trained learning algorithm is tailored to the specific patterns that can occur in the determined values in individual cases under real conditions.

Alternatively or additionally, the learning algorithm can also be trained with simulated values or model data. This allows components to be added to the algorithm that relate to idealized conditions.

For an optimal recognition performance with regard to the identification, classification and / or interpretation of patterns in a value group 11, training the algorithm with a combination of real and simulated or ideal data can be particularly expedient under certain circumstances.

In a further preferred embodiment, the data processing device 7 can use a particularly iterative method for modeling values. In particular, a method for forward modeling is used to determine values that are to be expected under certain working and / or environmental conditions. The values determined by means of such a modeling method can be used in different ways within the scope of the method according to the invention. For example, the parallel application of such a modeling method enables an independent verification of the measured values and / or of a pattern formed in the values.

Data obtained by way of forward modeling are also suitable for training a learning algorithm.

By comparing the evaluation of real data with the modeling of a specific development of the system, possible artifacts of the pattern identification can preferably be determined and, in particular, corrected. In this way, inadequacies in the learning algorithm can preferably be compensated for, which are expressed in this context and can be caused, among other things, by a non-optimal focus on the training of the algorithm. Repeated application of this approach thus continuously improves the reliability of the pattern identification.

Furthermore, a serial linking of the method according to the invention on the basis of pattern recognition with a corresponding method for modeling data on the basis of measured values is possible. In this way, for example, a future development can be modeled on the basis of known or measured starting parameters and the risk of an imminent structural failure of the object 1 through which the flow is flowing can be assessed in the results obtained by identifying occurring patterns.

In addition to taking into account data records 12 of a database in the manner explained above, data from external sources, in particular generally available data, can also be included in various ways. In particular, these data are added to the value group 11 and / or linked to the value group 11 in order to be taken into account in the evaluation. Such external data can, however, also be used in the context of modeling and / or for training a learning algorithm. The data can, for example, relate to the weather, the geological nature of the soil, which in particular relate to agricultural land use or the like. As part of the evaluation of the determined values or the value group 11 formed therefrom, a pattern is identified in the value group 11 and, if necessary, an interpretation of the pattern or some other assignment to a specific event or an event probability takes place. The data processing device 7 then preferably generates a corresponding output 13 which reproduces the result of the previous analysis or of the method used for a user.

The output 13 can take place in different ways, preferably optically, acoustically and / or in text form. In particular, the output 13, as shown in FIG. 3, can include a warning message about the presence of a leak 8. A status report can also be generated, for example.

With regard to an automatically operating system, remedial measures can alternatively or additionally also be initiated directly in connection with the output 13, for example an alarm can be given to maintenance and / or service personnel.

It goes without saying that, in principle, a combination of different outputs 13 or reactions to the result of the procedural analysis can also take place.

List of reference symbols:

Object flowed through Measuring section Measuring point flow meter

Pressure sensor 20

Temperature sensor

Data processing device

leak

soil

Relay station 25

Value group

record

output

Claims

Patent claims:

1. A method for leak detection on an object (1) through which a medium flows, in particular a pipe or a pipeline, with a value for a change each at a plurality of measurement points (3) on a measurement section (2) of the object (1) through which the medium flows the flow rate of the medium is determined for a change in pressure of the medium and a change in temperature value, and wherein the determined values are recorded by a data processing device (7) and statistically evaluated, characterized in that a value group (11) is formed from the determined values and by means of the data processing device (7) a pattern is identified in the value group (11) and a probability of the presence of a leak (8) in the measuring section (2) of the flowed object (1) is determined on the basis of the identified pattern.

2. The method according to claim 1, characterized in that a classification algorithm and / or a pattern analysis algorithm is applied to the identified pattern.

3. The method according to claim 1 or 2, characterized in that the identified pattern is stored as a data record (12) in a database and / or is assigned to a data record (12) stored in a database.

4. The method according to any one of the preceding claims, characterized in that the identified pattern is compared with one or more stored patterns.

5. The method according to any one of the preceding claims, characterized in that a characteristic pattern is used as the criterion for the presence of a leak

(8) in the measuring section (2) of the object (1) through which the air flows.

6. The method according to any one of the preceding claims, characterized in that the data processing device (7) applies a learning algorithm to the determined values and / or the value group (11).

7. The method according to claim 6, characterized in that the learning algorithm is trained with stored and / or simulated values prior to application to the determined values or the value group (11), the stored or simulated values being an actual and / or a simulated presence of a leak (8) on an object (1) through which a medium flows.

8. The method according to any one of the preceding claims, characterized in that the value for the change in the flow rate of the medium, the value for the change in the pressure of the medium and / or the change in temperature value are each determined non-invasively.

9. The method according to any one of the preceding claims, characterized in that the measurement of the change in the flow rate is carried out by means of an acoustic, preferably ultrasound-based method.

10. The method according to any one of the preceding claims, characterized in that data from an external source, in particular the weather in the vicinity of the measuring section (2) and / or a measuring point (3), processed by the data processing device (7), in particular with linked to the value group (11) and / or added to the value group (11).

11. The method according to any one of the preceding claims, characterized in that the determined values of various measuring points (3) are transmitted to a central data processing device (7), preferably wirelessly.

12. Computer program product for determining a probability of the presence of a leak (8) on an object (1) through which a medium flows, in particular a pipe or a pipeline, characterized by

Instructions for recognizing a pattern in a value group (11), the value group (11) using values for a change in the flow rate of the medium, for a pressure change in the medium and / or a Temperature change is formed.