Method and device to preserve the integrity of a pipeline

Abstract

A method to preserve integrity of a pipeline transporting a gas (100), wherein the pipeline (100) is connected to an integrity preservation device (200) comprising a compressor (220) and a tank (230), the method comprising: • Detecting (E1) or predicting a first situation in which a gas input in the pipeline (100) is above a gas output out of the pipeline (100); • When the first situation is detected or predicted, injecting (E2) gas from the pipeline (100) to the compressor (220); • Compressing or liquefying the injected gas with the compressor (220); • Storing (E2-1) the compressed or liquefied gas in the tank (230) as a stored gas.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method and device to preserve the integrity of a pipeline.BACKGROUND

[0002] A pipeline is a system of pipes for long-distance transportation of a fluid such as a gas, typically from a storage or generation area to a market area for consumption. For example, EP0011329 discloses a process and device for automatically detecting leaks in a pipeline. However, this process and device cannot prevent or reduce occurrence of leaks.SUMMARY OF THE DISCLOSURE

[0003] Pipelines are costly equipment requiring constant monitoring and maintenance. In particular, pipelines may be submitted to pressure variation, for example when a misbalance between gas injection at the generation area and gas consumption at the market area. Such a misbalance may occur due to technical problems, due to the weather affecting cooling and liquid loads, due to a non-predicted level of consumption or due to a non-predicted surge in production.

[0004] Such a misbalance or imbalance may result in important pressure or flow rate variations in the pipeline, thus resulting in important mechanical tensions in the pipeline walls. Such mechanical tensions or fatigue may finally result in leakages or premature replacement of pipeline sections, thus decreasing safety and economic effectiveness of the pipeline.

[0005] An aspect of the disclosure relates to a method to preserve integrity of a pipeline transporting a gas, wherein the pipeline is connected to an integrity preservation device comprising a compressor and a tank, the method comprising: Detecting or predicting a first situation in which a gas input in the pipeline is above a gas output out of the pipeline; When the first situation is detected or predicted, injecting gas from the pipeline to the compressor; Compressing or liquefying the injected gas with the compressor; Storing the compressed or liquefied gas in the tank as a stored gas.

[0006] With the above method, a gas pressure or flow in the pipeline may be decreased in order to preserve the pipeline from mechanical stress, without impacting the complex processes of gas generation and distribution. For example, the first situation relates to a situation in which the pressure or flow rate inside the pipeline is above a first threshold value, and / or a situation in which a planned, computed, or measured consumption rate is below a planned, computed or measured gas production rate or a gas injection rate in the pipeline. The pipeline of the above method is not necessarily the full pipeline but may be a pipeline section, such as a part of the pipeline between two points of interest such as between two pumping stations, or between the pipeline input or output and a pumping station. The stored gas may be liquefied gas and / or compressed gas, i.e. a gas under a pressure higher than the atmospheric pressure.

[0007] The integrity preservation method thus allows to increase a lifetime of a pipeline or pipeline section by actively limiting fatigue of the pipeline wall and also reducing the risks of sudden breakage. The present integrity device does not relate to an emergency method to prevent or mitigate a leak or an overpressure.

[0008] Advantageously, the integrity preservation device includes a heat energy storage, the method comprising: Recovering heat from the compressed or liquefied gas, for example through a first heat exchanger or by direct exchange with the heat energy storage; Storing the recovered heat in the heat energy storage.

[0009] With these additional steps and features, heat generated during compression or liquefaction may be saved and / or used, thus increasing the overall yield of the method. For example, heat may be stored under the form of a hot fluid, such as hot water, a hot solid or a mixture of hot solid and hot fluid.

[0010] Advantageously, the integrity preservation device includes a turbine, the method comprising: Detecting or predicting a second situation in which a gas input in the pipeline is below a gas output out of the pipeline; When the second situation is detected or predicted, decompressing the stored gas from the tank in the turbine, Generating electrical power with the turbine, Injecting the decompressed gas into the pipeline.

[0011] Due to the turbine and the above additional steps, a scenario in which the gas pressure or flow in the pipeline is too limited may be addressed. With this method, the gas pressure or flow in the pipeline may be kept under a limited operating range and the mechanical stress of the pipeline may be limited. For example, the second situation relates to a situation in which the pressure or flow rate inside the pipeline is below a second threshold value, and / or a situation in which a predicted (i.e. planned), computed, or measured consumption rate is above a predicted, computed or measured gas production rate or a gas injection rate in the pipeline.

[0012] Preferably, the heat stored in the heat energy storage may be used to heat the stored gas during or before decompression, thus limiting gas volume variation. The overall yield of the method may be increased with saving and reusing heat in the steps of compression and decompression, thus limiting power consumption. Heating can be performed though a second heat exchanger, though the first heats exchanger or by circulating the stored gas through the heat storage.

[0013] Another aspect of the disclosure relates to an integrity preservation device adapted to preserve integrity of a pipeline transporting a gas, the integrity preservation device being adapted to be connected to the pipeline, the integrity preservation device comprising: a compressor, a tank and a controller controlling the compressor and the connection of the integrity preservation device with the pipeline, wherein the controller is configured to compress or liquefy gas from the pipeline with the compressor and to store it in the tank as a stored gas, in a first situation in which a gas input in the pipeline is above a gas output out of the pipeline. Such an integrity preservation device relies on simple elements and may be easily connected to a pipeline to actively limit fatigue. This integrity preservation device is not an emergency device but rather a prevention device.

[0014] Advantageously, the gas transportation system may comprise a pipeline monitoring device configured to detect or predict the first situation. For example, the pipeline monitoring device detects or predicts a mismatch between a gas production rate and a gas consumption rate. The pipeline monitoring device can include one or more pressure sensor, gas flow sensor, temperature sensor or include acquisition of gas production and consumption data. The pipeline monitoring device may be part of the controller or may be connected to the controller.

[0015] Advantageously, the integrity preservation device comprises a heat energy storage and the controller is configured to recover heat from the compressed or liquefied gas circulating though a first heat exchanger and / or by circulating the compressed or liquefied gas though the heat energy storage and to store heat in the heat energy storage. The heat energy storage may comprise a solid and / or a fluid adapted to receive and store heat energy.

[0016] Advantageously, the integrity preservation device comprises a turbine controlled by the controller, and the controller is configured to decompress the stored gas in the turbine, to generate electrical power with the turbine and to inject the decompressed gas into the pipeline, in a second situation in which a gas input in the pipeline is detected or predicted below a gas output out of the pipeline.

[0017] Advantageously, the pipeline monitoring device is configured to detect or predict the second situation, preferably as described in regards of the first situation.

[0018] Advantageously, the controller is configured to heat the stored gas with the heat or thermal energy stored in the heat energy storage, for example before decompressing the stored gas in the turbine. This may be performed by circulating the stored gas through the first heat exchanger, through a second heat exchanger and / or through the heat energy storage.

[0019] Another aspect of the present disclosure is a gas transportation system including a pipeline transporting a gas and the integrity preservation device described above.

[0020] Another aspect of the present disclosure is a method to preserve integrity of a pipeline transporting hydrogen, wherein an integrity preservation device including a fuel cell is connected to the pipeline, the method comprising: Detecting or predicting a third situation in which a hydrogen input in the pipeline is above a hydrogen output out of the pipeline; When the third situation is detected or predicted, injecting hydrogen from the pipeline to the fuel cell; Consuming the injected hydrogen with the fuel cell to generate electrical power.

[0021] In the case of an overflow of hydrogen in the pipeline, some hydrogen may be consumed to generate electrical power, for example for local consumption or injection on the power grid. Consequently, mechanical stress of the pipeline may be limited while limiting the costs and preventing any waste flow of hydrogen. The third situation may be similar to the first situation, i.e. may be a situation in which the pressure or flow rate inside the pipeline is above a third threshold value, and / or a situation in which a planned, computed, or measured consumption rate is below a planned, computed or measured gas production rate or a gas injection rate in the pipeline.

[0022] Advantageously, the fuel cell is a regenerative fuel cell and / or the integrity preservation device includes an electrolyser, the method comprising: Detecting or predicting a fourth situation in which a hydrogen input in the pipeline is below a hydrogen output out of the pipeline; When the fourth situation is detected or predicted, generating hydrogen, for example from water or any proton-rich fluid, by the regenerative fuel cell and / or the electrolyser; Injecting the generated hydrogen into the pipeline.

[0023] In the case of low pressure or gas flow in the pipeline, hydrogen can be quickly generated and inserted in the pipeline, thus limiting mechanical stress on the pipeline wall caused by cyclic or non-cyclic loads due to internal pressure oscillations. The fourth situation may be similar to the second situation, i.e. may be a situation in which the pressure or flow rate inside the pipeline is below a fourth threshold value, and / or a situation in which a planned, computed, or measured consumption rate is above a planned, computed or measured gas production rate or a gas injection rate in the pipeline.

[0024] Advantageously, the integrity preservation device includes a reformer, the method comprising: Detecting or predicting a fourth situation in which a hydrogen input in the pipeline is below a hydrogen output out of the pipeline; Generating hydrogen by the reformer, for example from methane, ammonia or another source of proton; Injecting the generated hydrogen into the pipeline.

[0025] Another aspect of the disclosure relates to an integrity preservation device adapted to preserve integrity of a pipeline transporting hydrogen and connected to the pipeline, the integrity preservation device being adapted to be connected to the pipeline, the integrity preservation device including: A fuel cell connected to the pipeline, A controller controlling the fuel cell and the connection of the integrity preservation device with the pipeline; wherein the controller is configured to inject hydrogen from the pipeline into the fuel cell to generate electrical power with the fuel cell, in a third situation in which a hydrogen input in the pipeline is predicted or detected above a hydrogen output out of the pipeline.

[0026] Advantageously, the fuel cell is a regenerative fuel cell and / or the integrity preservation device includes an electrolyser controlled by the controller, and wherein the controller is configured to generate hydrogen by the regenerative fuel cell and / or the electrolyser in a fourth situation in which a hydrogen input in the pipeline is predicted or detected below a hydrogen output out of the pipeline.

[0027] Advantageously, the integrity preservation device includes a reformer controlled by the controller, and wherein the controller is configured to generate hydrogen with the reformer, from methane or ammonia in a fourth situation in which a hydrogen input in the pipeline is below a hydrogen output out of the pipeline. For example, methane or ammonia can be stored nearby the pipeline and / or a methane or ammonia pipeline nearby the hydrogen pipeline may be used.

[0028] Advantageously, the integrity preservation device includes a pipeline monitoring device configured to detect or predict the third situation and / or the fourth situation. The pipeline monitoring device may be as described above.

[0029] Another aspect of the present disclosure is a gas transportation system including a pipeline transporting hydrogen and the integrity preservation device described above.

[0030] Another aspect of the disclosure relates to a computer program comprising instructions to perform the steps of one of the above methods. Preferably, the computer program is intended to be used by a controller as described above.

[0031] Another aspect of the disclosure relates to a computer-readable medium storing instructions to cause a processor to perform operations comprising the method steps of one of the above methods.BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Further advantages and preferred embodiments of the present disclosure will become apparent from the following detailed description and drawings, in which: Figure 1 is a diagram of a general method according to the disclosure. Figure 2 is a schematic view of a gas transportation system according to the disclosure. Figure 3 is a diagram of a specific method according to the disclosure. Figure 4 is a schematic view of a hydrogen transportation system according to the disclosure. Figure 5 is a diagram of another specific method according to the disclosure. DETAILED DESCRIPTION

[0033] In the present disclosure, a pipeline is classically defined as a tubing system connecting a gas production or storage area to a gas consumption or storage area. The pipeline thus comprises tubing extending over 1 km, 10 km or more, at the surface, underground and / or underwater and adapted to transport a fluid such as a liquid and / or preferably a gas. The pipeline may be provided with the usual safety and monitoring system, such as sensors, valves, leak detection systems, emergency systems, compression stations, etc.

[0034] The present methods and devices have the general purpose of actively maintaining the pipeline walls in the best condition overtime in order to increase the lifetime of the pipeline elements, thus improving safety, preserving environment from leakages and reducing the needs for maintenance. The present methods and devices do not relate to an emergency method or device to mitigate or control risks or incidents on a pipeline or pipeline section.

[0035] Sudden changes in weather, economic conditions, or other factors could lead to a rapid decrease or increase in demand for gas, causing an unexpected drop or an unexpected peak in demand. If the input cannot be adjusted quickly enough, it could temporarily exceed the output or fall short of the input. In the case where the pipeline is connected to an industrial facility, the industrial facility that uses gas from the pipeline may experience an unplanned outage, reducing or stopping gas consumption. Alternatively, the industrial facility may have an unexpected rise in activity, leading to a non-anticipated rise in gas consumption.

[0036] Problems with equipment or processes at the gas input or output points could also lead to an imbalance. For example, a malfunctioning valve might allow too much or too few gas to enter the pipeline. Then, if there are physical constraints in the pipeline, such as a blockage or a section of pipeline that cannot handle high volumes, the input or output could be reduced regardless of the gas demand and consumption. Finally, disruptions elsewhere in the gas supply chain, such as issues with transportation or storage, could lead to more gas being input or output into the pipeline.

[0037] All these scenarios may lead to fatigue of the pipeline, as by cyclic or non-cyclic loads due to internal pressure oscillations results in mechanical constraints in the pipeline walls. Here, several scenarios may occur at the same time in different section of a same pipeline.General Method

[0038] Fig. 1 shows an overview of a method according to the disclosure. In a first step E1, a mismatch between input and output of the pipeline or of at least one pipeline section may be detected or predicted. For example, this mismatch detection may occur through a pipeline monitoring device including at least one gas sensor and / or at least one flow rate sensor. Additional or in combination, a mismatch prediction may occur through a computed, planned or expected difference between the input and the output of the pipeline and / or through a computed, measured or expected difference between a gas production rate and a gas consumption rate or gas injection rate into the pipeline, the input and output of the pipeline being flow rates and / or pressures.

[0039] After the mismatch is detected or predicted in step E1, if the mismatch results from a gas input greater than a gas output, some gas is removed from the pipeline in a second step E2. For example, this gas may be stored, in step E2-1 preferably in a compressed or liquefied form (i.e as stored gas). If compression occurs, the gas overflow may be compressed or liquefied and stored in a gas storage. In this case, heat energy generated by the compression is preferably stored and / or reused. If the gas is hydrogen, it may be used to generate electrical power by reaction with oxygen or air in step E2-2, or be recombined with another reactant.

[0040] Alternatively or in combination, if the mismatch results from a gas output greater than a gas input, gas is injected in the pipeline from storage or from generation, in a third step E3. For example, the injected gas may be the gas stored in step E2-1 which is then decompressed in step E3-1. If the decompression step occurs, the heat stored in step E2-1 may be reused, at least partially. Preferably, electrical power may be produced during decompression. Alternatively, if the gas is hydrogen, hydrogen can be generated in step E3-2 from water, methane, ammonia and / or an hydrogencontaining electrolyte such as HBR and injected in the pipeline.First Embodiment

[0041] A first embodiment of the above general method may be applied in the case of a pipeline 100 transporting any gas. For example, the gas may be carbon dioxide, oxygen, methane, nitrogen or argon. Fig. 2 shows an integrity preservation device 200 connected to a pipeline 100 transportation a gas such as carbon dioxide. The integrity preservation device 200 may comprise a controller 210, a compressor 220, a tank 230 for storing liquid or compressed gas and a decompressor unit or turbine 240 or alternatively a pressure relief valve. Preferably, the integrity preservation device 200 comprises a first heat exchanger 250, a heat energy storage 260 and a second heat exchanger 270.

[0042] The controller 210 may comprise one or several processors, memories, wired or wireless interfaces, input devices and / or displays and may control or at least monitor the above elements of the integrity preservation device 200 (not shown in Fig. 2). The controller 210 may run a controller program, for example loaded on a computer-readable medium. The controller 210 may include or command several controllers connected to each of the above elements. The controller 210 may be connected to or include a pipeline monitoring device monitoring one or several of a pressure inside the pipeline or inside a pipeline section, a pressure at the pipeline input, a pressure at the pipeline output, a flow rate inside the pipeline or inside a pipeline section, a pressure at the pipeline input, a pressure at the pipeline output, an inside temperature of the pipeline or of a pipeline section, an outside temperature in an area of the pipeline.

[0043] Alternatively or in combination, the pipeline monitoring device may receive data from an expected, planned, computed or measure gas production, gas storage, gas injection rate into the pipeline and data from an expected, planned, computed or measure gas consumption at the output of the pipeline. Finally, the pipeline monitoring device may receive atmospheric pressure values in an area of the pipeline and / or weather forecast. The pipeline monitoring device may include one or several processors and one or several algorithms or machine leaning models dedicated at predicting the mismatch situation. Here, machine learning models may be trained on numerous past data including the factors cited above.

[0044] An exemplary method of the present disclosure is shown in Fig. 3. According to the carbon dioxide or gas pressure P. measured in the pipeline 100 by the controller 210, different scenarios are possible. If the gas pressure P. is equal to a nominal pressure value or within a nominal pressure range, for example between a first pressure value P1 and a second pressure value P2, the integrity preservation device may remain inactive.

[0045] Then, if the gas pressure P. is detected or predicted above the first pressure value P1 (first scenario), carbon dioxide may be removed from the pipeline 100 and compressed or liquefied by the compressor 220, for example using power coming from a power source or the power grid. The compressed or liquid carbon dioxide may then be stored in the liquid storage or tank 230 under liquid and / or gaseous pressure.

[0046] Preferably, heat produced during compression is recovered by the first heat exchanger 250 and stored in the heat energy storage 260. The heat energy may be stored in the form of a hot fluid and / or hot solid and may include sensible and / or latent heat. A hot fluid may be hot water or any heat-transfer fluid. The heat energy storage 260 may thus be a liquid tank, preferably with insulated walls. Alternatively or in combination, the heat energy storage 260 may comprise a hot solid. The hot solid may be heated directly by the compressed or liquefied gas circulating through it, and in this case the first heat exchanger 250 may not be used. The hot solid may change phase. The hot solid may also be heated by a hot fluid receiving heat from the first heat exchange 250.

[0047] For example, a hot fluid may be water, ethylene glycol, propylene glycol, one or more mineral oils, one or more silicon oils, a synthetic heat transfer fluid (e.g. Dowtherm ™< or Therminol ®< ), a gycol-water mixture, a refrigerant (e.g. R-134a, R-410A), an anionic liquid, a nanofluid, a molten salt or a liquid metal. A hot solid may comprise or consist in concrete, brick, stone, sand, a Phase Change Materials (PCMs - e.g. paraffin wax, fatty acids, salt hydrates, eutectic mixtures), one or several metals (e.g. aluminum, copper, iron), refractory materials (e.g. fine bricks, refractory concrete, ceramics), graphite, cast iron or a molten salt (when solidified).

[0048] To compress or liquefy carbon dioxide, the controller 210 may open appropriate valves and start the compressor 220 with an appropriate pressure and / or flow rate setpoint. The controller 210 may further control the first heat exchanger 250 to recover heat from the compressed gas, with an appropriate temperature setpoint for the compressed or liquefied gas output from the first heat exchanger 250. The controller 210 may control the compressor 220 until the pressure or flow rate in the pipeline 100 reaches the first value, according to the gas level of the tank 230 and / or according to a price of electrical power.

[0049] In contrast, if the gas pressure P. is detected or predicted below the second pressure value P2 (second scenario), the compressed or liquefied carbon dioxide may be decompressed or regasified and reinjected in the pipeline 300 by a decompressor or the pressure relief valve. Preferably, the decompressed gas is introduced through the turbine 240 allowing to produce electrical power and the gas may be decompressed in the turbine. The produced electrical power can then be injected on the power grid, be stored or be used in other devices linked to the pipeline 300 or to nearby electrical systems. The stored gas from the tank 230 can be heated through the second heat exchanger 270, for example using the heat energy stored in the heat energy storage 260 and / or by circulating the stored gas through the hot solid of the heat energy storage.

[0050] For example, the controller 210 may open appropriate valves and start the second heat exchanger 270. The flow rate or pressure of the gas introduced in the turbine 240 can be controlled by the controller 210 according to the pressure P. in the pipeline 100, a gas or liquid level in the tank 230, a heat storage level in the heat energy storage 260, and / or a power demand on the power grid.

[0051] Both scenarios may be performed by the integrity preservation device 200. Alternatively, a first integrity preservation device may perform the first scenario of reducing the gas pressure P. inside the pipeline and a second integrity preservation device may perform the second scenario of increasing the gas pressure P. inside the pipeline 100. In this case, the liquefied carbon dioxide may be stored in bottles for further use or transported through a second pipeline and the heat recovered from the first heat exchanger 250 may be used for heating households or nearby industrial installations.

[0052] The first integrity preservation device and the second integrity preservation device may be integrated in the same facilities and share some tubing and control devices. The pipeline transporting a gas and the integrity preservation device may form a gas transportation system.Second Embodiment

[0053] A second embodiment of the above general method may be applied in the case of a pipeline 300 transporting hydrogen. Fig. 4 shows a pipeline 300 transporting hydrogen and connected to an integrity preservation device 400. The integrity preservation device 400 is fluidly connected with the pipeline 100 through valves and tubing. It may include at least a controller 410 and a fuel cell 420, and optionally a pressure-reducing valve 430 and / or a compressor 440. The controller 410 may include one or several processors, memories, wired or wireless interfaces, input devices and / or displays and may control or at least monitor the above elements of the integrity preservation device 400. The controller 410 may be substantially similar to the controller 210 of the first embodiment.

[0054] An exemplary method of the present disclosure is shown in Fig. 4. According to the hydrogen or gas pressure or flow rate measured, predicted or estimated in the pipeline, different scenarios are possible. If the gas pressure P. is equal to a nominal pressure value or in a nominal range for example between a third pressure value P3 and a fourth pressure value P4, the integrity preservation device 400 may remain inactive.

[0055] Then, if the gas pressure P. is detected or predicted above the fourth pressure value P4 (first scenario), hydrogen may be removed from the pipeline and power may be generated by the fuel cell 420. For example, the fuel cell 420 may recombine hydrogen with oxygen from an oxygen storage or ambient air. Alternatively, the fuel cell may combine hydrogen with an electrolyte (such as bromine, chlorine, fluorine, lithium carbonate, potassium carbonate, alkoxide, carboxylate or derivatives) or an organic compound (such as carbon dioxide, NOx, peroxide...) in a closed circuit and the fuel cell 420 can thus be part of a redox flow battery.

[0056] The produced electrical power may for example be used to power other systems of the pipeline or reinjected in the power grid. Pure water is also produced by the fuel cell 420 and may be stored, used and / or released in the environment. Due to this hydrogen removal, the gas pressure P. in the pipeline may decrease, for example down to the fourth pressure value P4, the third pressure value P3 or any intermediary pressure value while contributing to generate energy.

[0057] For example, appropriate valves may be opened by the controller 410 and the fuel cell 420 may be progressively started and supplied with hydrogen from the pipeline 300. The hydrogen pressure injected in the fuel cell 420 may be regulated by the pressure-reducing valve 430 in order to correspond to an acceptable pressure of the fuel cell 420. The fuel cell 420 may be controlled by the controller 410 to produce electrical power as long as the gas pressure P. in the pipeline 300 does not reach the fourth pressure value P4, the third pressure value P3, another predetermined pressure value and / or according to power demand on the power grid, as described with regard to the first embodiment.

[0058] In contrast, the gas pressure P. in the pipeline 300 may be below a third pressure value P3 (second scenario). The fuel cell 420 may be a regenerative fuel cell and hydrogen can be produced from electrical power of the power grid, of a renewable source or of a power storage and water, electrolyte or an organic solvent, and reintroduced in the pipeline, in order to increase gas pressure P. in the pipeline 100. The gas pressure P. may thus be increased, for example up to the third pressure P3.

[0059] For example, the regenerative fuel cell 420 may be provided with power and water and / or a proton-rich electrolyte such as HBR, HCl, HF, or an organic compound by the controller 410 and may start generating hydrogen. This hydrogen may be compressed by the compressor 440 in order to reach a pressure equal or higher than the pressure P. in the pipeline 300 and / or the third pressure value P3.

[0060] Both scenarios may be performed by the integrity preservation device 400. Alternatively, an integrity preservation device may perform the first scenario of reducing the gas pressure P. inside the pipeline and another integrity preservation device may perform the second scenario. In this case, the integrity preservation device may include a normal fuel cell and the another integrity preservation device may have a hydrogen producer different from a regenerative fuel cell, such as a water electrolyser, a methane reformer or an ammonia reformer.

[0061] Both integrity preservation devices may be integrated in the same facilities and share some tubing and control device. The pipeline transporting hydrogen and the integrity preservation device may form a hydrogen transportation system.

[0062] The first embodiment and the second embodiment described above both contribute to preserving integrity of a pipeline by actively limiting wall fatigue, with an improved efficiency and a small footprint. The first and second embodiments do not relate to emergency devices and methods but relate to a smart pipeline operating method and smart pipeline management device increasing the lifetime of a pipeline or pipeline section.

[0063] Although the present disclosure has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitations, the scope of the present disclosure being limited only by the terms of the appended claims.

Examples

first embodiment

[0041]A first embodiment of the above general method may be applied in the case of a pipeline 100 transporting any gas. For example, the gas may be carbon dioxide, oxygen, methane, nitrogen or argon. Fig. 2 shows an integrity preservation device 200 connected to a pipeline 100 transportation a gas such as carbon dioxide. The integrity preservation device 200 may comprise a controller 210, a compressor 220, a tank 230 for storing liquid or compressed gas and a decompressor unit or turbine 240 or alternatively a pressure relief valve. Preferably, the integrity preservation device 200 comprises a first heat exchanger 250, a heat energy storage 260 and a second heat exchanger 270.

[0042]The controller 210 may comprise one or several processors, memories, wired or wireless interfaces, input devices and / or displays and may control or at least monitor the above elements of the integrity preservation device 200 (not shown in Fig. 2). The controller 210 may run a controller program, for examp...

second embodiment

[0053]A second embodiment of the above general method may be applied in the case of a pipeline 300 transporting hydrogen. Fig. 4 shows a pipeline 300 transporting hydrogen and connected to an integrity preservation device 400. The integrity preservation device 400 is fluidly connected with the pipeline 100 through valves and tubing. It may include at least a controller 410 and a fuel cell 420, and optionally a pressure-reducing valve 430 and / or a compressor 440. The controller 410 may include one or several processors, memories, wired or wireless interfaces, input devices and / or displays and may control or at least monitor the above elements of the integrity preservation device 400. The controller 410 may be substantially similar to the controller 210 of the first embodiment.

[0054]An exemplary method of the present disclosure is shown in Fig. 4. According to the hydrogen or gas pressure or flow rate measured, predicted or estimated in the pipeline, different scenarios are possible. ...

TECHNICAL FIELD

[0001] The present disclosure relates to a method and device to preserve the integrity of a pipeline.BACKGROUND

[0002] A pipeline is a system of pipes for long-distance transportation of a fluid such as a gas, typically from a storage or generation area to a market area for consumption. For example, EP0011329 discloses a process and device for automatically detecting leaks in a pipeline. However, this process and device cannot prevent or reduce occurrence of leaks.SUMMARY OF THE DISCLOSURE

[0003] Pipelines are costly equipment requiring constant monitoring and maintenance. In particular, pipelines may be submitted to pressure variation, for example when a misbalance between gas injection at the generation area and gas consumption at the market area. Such a misbalance may occur due to technical problems, due to the weather affecting cooling and liquid loads, due to a non-predicted level of consumption or due to a non-predicted surge in production.

[0004] Such a misbalance or imbalance may result in important pressure or flow rate variations in the pipeline, thus resulting in important mechanical tensions in the pipeline walls. Such mechanical tensions or fatigue may finally result in leakages or premature replacement of pipeline sections, thus decreasing safety and economic effectiveness of the pipeline.

[0005] An aspect of the disclosure relates to a method to preserve integrity of a pipeline transporting a gas, wherein the pipeline is connected to an integrity preservation device comprising a compressor and a tank, the method comprising: Detecting or predicting a first situation in which a gas input in the pipeline is above a gas output out of the pipeline; When the first situation is detected or predicted, injecting gas from the pipeline to the compressor; Compressing or liquefying the injected gas with the compressor; Storing the compressed or liquefied gas in the tank as a stored gas.

[0006] With the above method, a gas pressure or flow in the pipeline may be decreased in order to preserve the pipeline from mechanical stress, without impacting the complex processes of gas generation and distribution. For example, the first situation relates to a situation in which the pressure or flow rate inside the pipeline is above a first threshold value, and / or a situation in which a planned, computed, or measured consumption rate is below a planned, computed or measured gas production rate or a gas injection rate in the pipeline. The pipeline of the above method is not necessarily the full pipeline but may be a pipeline section, such as a part of the pipeline between two points of interest such as between two pumping stations, or between the pipeline input or output and a pumping station. The stored gas may be liquefied gas and / or compressed gas, i.e. a gas under a pressure higher than the atmospheric pressure.

[0007] The integrity preservation method thus allows to increase a lifetime of a pipeline or pipeline section by actively limiting fatigue of the pipeline wall and also reducing the risks of sudden breakage. The present integrity device does not relate to an emergency method to prevent or mitigate a leak or an overpressure.

[0008] Advantageously, the integrity preservation device includes a heat energy storage, the method comprising: Recovering heat from the compressed or liquefied gas, for example through a first heat exchanger or by direct exchange with the heat energy storage; Storing the recovered heat in the heat energy storage.

[0009] With these additional steps and features, heat generated during compression or liquefaction may be saved and / or used, thus increasing the overall yield of the method. For example, heat may be stored under the form of a hot fluid, such as hot water, a hot solid or a mixture of hot solid and hot fluid.

[0010] Advantageously, the integrity preservation device includes a turbine, the method comprising: Detecting or predicting a second situation in which a gas input in the pipeline is below a gas output out of the pipeline; When the second situation is detected or predicted, decompressing the stored gas from the tank in the turbine, Generating electrical power with the turbine, Injecting the decompressed gas into the pipeline.

[0011] Due to the turbine and the above additional steps, a scenario in which the gas pressure or flow in the pipeline is too limited may be addressed. With this method, the gas pressure or flow in the pipeline may be kept under a limited operating range and the mechanical stress of the pipeline may be limited. For example, the second situation relates to a situation in which the pressure or flow rate inside the pipeline is below a second threshold value, and / or a situation in which a predicted (i.e. planned), computed, or measured consumption rate is above a predicted, computed or measured gas production rate or a gas injection rate in the pipeline.

[0012] Preferably, the heat stored in the heat energy storage may be used to heat the stored gas during or before decompression, thus limiting gas volume variation. The overall yield of the method may be increased with saving and reusing heat in the steps of compression and decompression, thus limiting power consumption. Heating can be performed though a second heat exchanger, though the first heats exchanger or by circulating the stored gas through the heat storage.

[0013] Another aspect of the disclosure relates to an integrity preservation device adapted to preserve integrity of a pipeline transporting a gas, the integrity preservation device being adapted to be connected to the pipeline, the integrity preservation device comprising: a compressor, a tank and a controller controlling the compressor and the connection of the integrity preservation device with the pipeline, wherein the controller is configured to compress or liquefy gas from the pipeline with the compressor and to store it in the tank as a stored gas, in a first situation in which a gas input in the pipeline is above a gas output out of the pipeline. Such an integrity preservation device relies on simple elements and may be easily connected to a pipeline to actively limit fatigue. This integrity preservation device is not an emergency device but rather a prevention device.

[0014] Advantageously, the gas transportation system may comprise a pipeline monitoring device configured to detect or predict the first situation. For example, the pipeline monitoring device detects or predicts a mismatch between a gas production rate and a gas consumption rate. The pipeline monitoring device can include one or more pressure sensor, gas flow sensor, temperature sensor or include acquisition of gas production and consumption data. The pipeline monitoring device may be part of the controller or may be connected to the controller.

[0015] Advantageously, the integrity preservation device comprises a heat energy storage and the controller is configured to recover heat from the compressed or liquefied gas circulating though a first heat exchanger and / or by circulating the compressed or liquefied gas though the heat energy storage and to store heat in the heat energy storage. The heat energy storage may comprise a solid and / or a fluid adapted to receive and store heat energy.

[0016] Advantageously, the integrity preservation device comprises a turbine controlled by the controller, and the controller is configured to decompress the stored gas in the turbine, to generate electrical power with the turbine and to inject the decompressed gas into the pipeline, in a second situation in which a gas input in the pipeline is detected or predicted below a gas output out of the pipeline.

[0017] Advantageously, the pipeline monitoring device is configured to detect or predict the second situation, preferably as described in regards of the first situation.

[0018] Advantageously, the controller is configured to heat the stored gas with the heat or thermal energy stored in the heat energy storage, for example before decompressing the stored gas in the turbine. This may be performed by circulating the stored gas through the first heat exchanger, through a second heat exchanger and / or through the heat energy storage.

[0019] Another aspect of the present disclosure is a gas transportation system including a pipeline transporting a gas and the integrity preservation device described above.

[0020] Another aspect of the present disclosure is a method to preserve integrity of a pipeline transporting hydrogen, wherein an integrity preservation device including a fuel cell is connected to the pipeline, the method comprising: Detecting or predicting a third situation in which a hydrogen input in the pipeline is above a hydrogen output out of the pipeline; When the third situation is detected or predicted, injecting hydrogen from the pipeline to the fuel cell; Consuming the injected hydrogen with the fuel cell to generate electrical power.

[0021] In the case of an overflow of hydrogen in the pipeline, some hydrogen may be consumed to generate electrical power, for example for local consumption or injection on the power grid. Consequently, mechanical stress of the pipeline may be limited while limiting the costs and preventing any waste flow of hydrogen. The third situation may be similar to the first situation, i.e. may be a situation in which the pressure or flow rate inside the pipeline is above a third threshold value, and / or a situation in which a planned, computed, or measured consumption rate is below a planned, computed or measured gas production rate or a gas injection rate in the pipeline.

[0022] Advantageously, the fuel cell is a regenerative fuel cell and / or the integrity preservation device includes an electrolyser, the method comprising: Detecting or predicting a fourth situation in which a hydrogen input in the pipeline is below a hydrogen output out of the pipeline; When the fourth situation is detected or predicted, generating hydrogen, for example from water or any proton-rich fluid, by the regenerative fuel cell and / or the electrolyser; Injecting the generated hydrogen into the pipeline.

[0023] In the case of low pressure or gas flow in the pipeline, hydrogen can be quickly generated and inserted in the pipeline, thus limiting mechanical stress on the pipeline wall caused by cyclic or non-cyclic loads due to internal pressure oscillations. The fourth situation may be similar to the second situation, i.e. may be a situation in which the pressure or flow rate inside the pipeline is below a fourth threshold value, and / or a situation in which a planned, computed, or measured consumption rate is above a planned, computed or measured gas production rate or a gas injection rate in the pipeline.

[0024] Advantageously, the integrity preservation device includes a reformer, the method comprising: Detecting or predicting a fourth situation in which a hydrogen input in the pipeline is below a hydrogen output out of the pipeline; Generating hydrogen by the reformer, for example from methane, ammonia or another source of proton; Injecting the generated hydrogen into the pipeline.

[0025] Another aspect of the disclosure relates to an integrity preservation device adapted to preserve integrity of a pipeline transporting hydrogen and connected to the pipeline, the integrity preservation device being adapted to be connected to the pipeline, the integrity preservation device including: A fuel cell connected to the pipeline, A controller controlling the fuel cell and the connection of the integrity preservation device with the pipeline; wherein the controller is configured to inject hydrogen from the pipeline into the fuel cell to generate electrical power with the fuel cell, in a third situation in which a hydrogen input in the pipeline is predicted or detected above a hydrogen output out of the pipeline.

[0026] Advantageously, the fuel cell is a regenerative fuel cell and / or the integrity preservation device includes an electrolyser controlled by the controller, and wherein the controller is configured to generate hydrogen by the regenerative fuel cell and / or the electrolyser in a fourth situation in which a hydrogen input in the pipeline is predicted or detected below a hydrogen output out of the pipeline.

[0027] Advantageously, the integrity preservation device includes a reformer controlled by the controller, and wherein the controller is configured to generate hydrogen with the reformer, from methane or ammonia in a fourth situation in which a hydrogen input in the pipeline is below a hydrogen output out of the pipeline. For example, methane or ammonia can be stored nearby the pipeline and / or a methane or ammonia pipeline nearby the hydrogen pipeline may be used.

[0028] Advantageously, the integrity preservation device includes a pipeline monitoring device configured to detect or predict the third situation and / or the fourth situation. The pipeline monitoring device may be as described above.

[0029] Another aspect of the present disclosure is a gas transportation system including a pipeline transporting hydrogen and the integrity preservation device described above.

[0030] Another aspect of the disclosure relates to a computer program comprising instructions to perform the steps of one of the above methods. Preferably, the computer program is intended to be used by a controller as described above.

[0031] Another aspect of the disclosure relates to a computer-readable medium storing instructions to cause a processor to perform operations comprising the method steps of one of the above methods.BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Further advantages and preferred embodiments of the present disclosure will become apparent from the following detailed description and drawings, in which: Figure 1 is a diagram of a general method according to the disclosure. Figure 2 is a schematic view of a gas transportation system according to the disclosure. Figure 3 is a diagram of a specific method according to the disclosure. Figure 4 is a schematic view of a hydrogen transportation system according to the disclosure. Figure 5 is a diagram of another specific method according to the disclosure. DETAILED DESCRIPTION

[0033] In the present disclosure, a pipeline is classically defined as a tubing system connecting a gas production or storage area to a gas consumption or storage area. The pipeline thus comprises tubing extending over 1 km, 10 km or more, at the surface, underground and / or underwater and adapted to transport a fluid such as a liquid and / or preferably a gas. The pipeline may be provided with the usual safety and monitoring system, such as sensors, valves, leak detection systems, emergency systems, compression stations, etc.

[0034] The present methods and devices have the general purpose of actively maintaining the pipeline walls in the best condition overtime in order to increase the lifetime of the pipeline elements, thus improving safety, preserving environment from leakages and reducing the needs for maintenance. The present methods and devices do not relate to an emergency method or device to mitigate or control risks or incidents on a pipeline or pipeline section.

[0035] Sudden changes in weather, economic conditions, or other factors could lead to a rapid decrease or increase in demand for gas, causing an unexpected drop or an unexpected peak in demand. If the input cannot be adjusted quickly enough, it could temporarily exceed the output or fall short of the input. In the case where the pipeline is connected to an industrial facility, the industrial facility that uses gas from the pipeline may experience an unplanned outage, reducing or stopping gas consumption. Alternatively, the industrial facility may have an unexpected rise in activity, leading to a non-anticipated rise in gas consumption.

[0036] Problems with equipment or processes at the gas input or output points could also lead to an imbalance. For example, a malfunctioning valve might allow too much or too few gas to enter the pipeline. Then, if there are physical constraints in the pipeline, such as a blockage or a section of pipeline that cannot handle high volumes, the input or output could be reduced regardless of the gas demand and consumption. Finally, disruptions elsewhere in the gas supply chain, such as issues with transportation or storage, could lead to more gas being input or output into the pipeline.

[0037] All these scenarios may lead to fatigue of the pipeline, as by cyclic or non-cyclic loads due to internal pressure oscillations results in mechanical constraints in the pipeline walls. Here, several scenarios may occur at the same time in different section of a same pipeline.General Method

[0038] Fig. 1 shows an overview of a method according to the disclosure. In a first step E1, a mismatch between input and output of the pipeline or of at least one pipeline section may be detected or predicted. For example, this mismatch detection may occur through a pipeline monitoring device including at least one gas sensor and / or at least one flow rate sensor. Additional or in combination, a mismatch prediction may occur through a computed, planned or expected difference between the input and the output of the pipeline and / or through a computed, measured or expected difference between a gas production rate and a gas consumption rate or gas injection rate into the pipeline, the input and output of the pipeline being flow rates and / or pressures.

[0039] After the mismatch is detected or predicted in step E1, if the mismatch results from a gas input greater than a gas output, some gas is removed from the pipeline in a second step E2. For example, this gas may be stored, in step E2-1 preferably in a compressed or liquefied form (i.e as stored gas). If compression occurs, the gas overflow may be compressed or liquefied and stored in a gas storage. In this case, heat energy generated by the compression is preferably stored and / or reused. If the gas is hydrogen, it may be used to generate electrical power by reaction with oxygen or air in step E2-2, or be recombined with another reactant.

[0040] Alternatively or in combination, if the mismatch results from a gas output greater than a gas input, gas is injected in the pipeline from storage or from generation, in a third step E3. For example, the injected gas may be the gas stored in step E2-1 which is then decompressed in step E3-1. If the decompression step occurs, the heat stored in step E2-1 may be reused, at least partially. Preferably, electrical power may be produced during decompression. Alternatively, if the gas is hydrogen, hydrogen can be generated in step E3-2 from water, methane, ammonia and / or an hydrogencontaining electrolyte such as HBR and injected in the pipeline.First Embodiment

[0041] A first embodiment of the above general method may be applied in the case of a pipeline 100 transporting any gas. For example, the gas may be carbon dioxide, oxygen, methane, nitrogen or argon. Fig. 2 shows an integrity preservation device 200 connected to a pipeline 100 transportation a gas such as carbon dioxide. The integrity preservation device 200 may comprise a controller 210, a compressor 220, a tank 230 for storing liquid or compressed gas and a decompressor unit or turbine 240 or alternatively a pressure relief valve. Preferably, the integrity preservation device 200 comprises a first heat exchanger 250, a heat energy storage 260 and a second heat exchanger 270.

[0042] The controller 210 may comprise one or several processors, memories, wired or wireless interfaces, input devices and / or displays and may control or at least monitor the above elements of the integrity preservation device 200 (not shown in Fig. 2). The controller 210 may run a controller program, for example loaded on a computer-readable medium. The controller 210 may include or command several controllers connected to each of the above elements. The controller 210 may be connected to or include a pipeline monitoring device monitoring one or several of a pressure inside the pipeline or inside a pipeline section, a pressure at the pipeline input, a pressure at the pipeline output, a flow rate inside the pipeline or inside a pipeline section, a pressure at the pipeline input, a pressure at the pipeline output, an inside temperature of the pipeline or of a pipeline section, an outside temperature in an area of the pipeline.

[0043] Alternatively or in combination, the pipeline monitoring device may receive data from an expected, planned, computed or measure gas production, gas storage, gas injection rate into the pipeline and data from an expected, planned, computed or measure gas consumption at the output of the pipeline. Finally, the pipeline monitoring device may receive atmospheric pressure values in an area of the pipeline and / or weather forecast. The pipeline monitoring device may include one or several processors and one or several algorithms or machine leaning models dedicated at predicting the mismatch situation. Here, machine learning models may be trained on numerous past data including the factors cited above.

[0044] An exemplary method of the present disclosure is shown in Fig. 3. According to the carbon dioxide or gas pressure P. measured in the pipeline 100 by the controller 210, different scenarios are possible. If the gas pressure P. is equal to a nominal pressure value or within a nominal pressure range, for example between a first pressure value P1 and a second pressure value P2, the integrity preservation device may remain inactive.

[0045] Then, if the gas pressure P. is detected or predicted above the first pressure value P1 (first scenario), carbon dioxide may be removed from the pipeline 100 and compressed or liquefied by the compressor 220, for example using power coming from a power source or the power grid. The compressed or liquid carbon dioxide may then be stored in the liquid storage or tank 230 under liquid and / or gaseous pressure.

[0046] Preferably, heat produced during compression is recovered by the first heat exchanger 250 and stored in the heat energy storage 260. The heat energy may be stored in the form of a hot fluid and / or hot solid and may include sensible and / or latent heat. A hot fluid may be hot water or any heat-transfer fluid. The heat energy storage 260 may thus be a liquid tank, preferably with insulated walls. Alternatively or in combination, the heat energy storage 260 may comprise a hot solid. The hot solid may be heated directly by the compressed or liquefied gas circulating through it, and in this case the first heat exchanger 250 may not be used. The hot solid may change phase. The hot solid may also be heated by a hot fluid receiving heat from the first heat exchange 250.

[0047] For example, a hot fluid may be water, ethylene glycol, propylene glycol, one or more mineral oils, one or more silicon oils, a synthetic heat transfer fluid (e.g. Dowtherm ™< or Therminol ®< ), a gycol-water mixture, a refrigerant (e.g. R-134a, R-410A), an anionic liquid, a nanofluid, a molten salt or a liquid metal. A hot solid may comprise or consist in concrete, brick, stone, sand, a Phase Change Materials (PCMs - e.g. paraffin wax, fatty acids, salt hydrates, eutectic mixtures), one or several metals (e.g. aluminum, copper, iron), refractory materials (e.g. fine bricks, refractory concrete, ceramics), graphite, cast iron or a molten salt (when solidified).

[0048] To compress or liquefy carbon dioxide, the controller 210 may open appropriate valves and start the compressor 220 with an appropriate pressure and / or flow rate setpoint. The controller 210 may further control the first heat exchanger 250 to recover heat from the compressed gas, with an appropriate temperature setpoint for the compressed or liquefied gas output from the first heat exchanger 250. The controller 210 may control the compressor 220 until the pressure or flow rate in the pipeline 100 reaches the first value, according to the gas level of the tank 230 and / or according to a price of electrical power.

[0049] In contrast, if the gas pressure P. is detected or predicted below the second pressure value P2 (second scenario), the compressed or liquefied carbon dioxide may be decompressed or regasified and reinjected in the pipeline 300 by a decompressor or the pressure relief valve. Preferably, the decompressed gas is introduced through the turbine 240 allowing to produce electrical power and the gas may be decompressed in the turbine. The produced electrical power can then be injected on the power grid, be stored or be used in other devices linked to the pipeline 300 or to nearby electrical systems. The stored gas from the tank 230 can be heated through the second heat exchanger 270, for example using the heat energy stored in the heat energy storage 260 and / or by circulating the stored gas through the hot solid of the heat energy storage.

[0050] For example, the controller 210 may open appropriate valves and start the second heat exchanger 270. The flow rate or pressure of the gas introduced in the turbine 240 can be controlled by the controller 210 according to the pressure P. in the pipeline 100, a gas or liquid level in the tank 230, a heat storage level in the heat energy storage 260, and / or a power demand on the power grid.

[0051] Both scenarios may be performed by the integrity preservation device 200. Alternatively, a first integrity preservation device may perform the first scenario of reducing the gas pressure P. inside the pipeline and a second integrity preservation device may perform the second scenario of increasing the gas pressure P. inside the pipeline 100. In this case, the liquefied carbon dioxide may be stored in bottles for further use or transported through a second pipeline and the heat recovered from the first heat exchanger 250 may be used for heating households or nearby industrial installations.

[0052] The first integrity preservation device and the second integrity preservation device may be integrated in the same facilities and share some tubing and control devices. The pipeline transporting a gas and the integrity preservation device may form a gas transportation system.Second Embodiment

[0053] A second embodiment of the above general method may be applied in the case of a pipeline 300 transporting hydrogen. Fig. 4 shows a pipeline 300 transporting hydrogen and connected to an integrity preservation device 400. The integrity preservation device 400 is fluidly connected with the pipeline 100 through valves and tubing. It may include at least a controller 410 and a fuel cell 420, and optionally a pressure-reducing valve 430 and / or a compressor 440. The controller 410 may include one or several processors, memories, wired or wireless interfaces, input devices and / or displays and may control or at least monitor the above elements of the integrity preservation device 400. The controller 410 may be substantially similar to the controller 210 of the first embodiment.

[0054] An exemplary method of the present disclosure is shown in Fig. 4. According to the hydrogen or gas pressure or flow rate measured, predicted or estimated in the pipeline, different scenarios are possible. If the gas pressure P. is equal to a nominal pressure value or in a nominal range for example between a third pressure value P3 and a fourth pressure value P4, the integrity preservation device 400 may remain inactive.

[0055] Then, if the gas pressure P. is detected or predicted above the fourth pressure value P4 (first scenario), hydrogen may be removed from the pipeline and power may be generated by the fuel cell 420. For example, the fuel cell 420 may recombine hydrogen with oxygen from an oxygen storage or ambient air. Alternatively, the fuel cell may combine hydrogen with an electrolyte (such as bromine, chlorine, fluorine, lithium carbonate, potassium carbonate, alkoxide, carboxylate or derivatives) or an organic compound (such as carbon dioxide, NOx, peroxide...) in a closed circuit and the fuel cell 420 can thus be part of a redox flow battery.

[0056] The produced electrical power may for example be used to power other systems of the pipeline or reinjected in the power grid. Pure water is also produced by the fuel cell 420 and may be stored, used and / or released in the environment. Due to this hydrogen removal, the gas pressure P. in the pipeline may decrease, for example down to the fourth pressure value P4, the third pressure value P3 or any intermediary pressure value while contributing to generate energy.

[0057] For example, appropriate valves may be opened by the controller 410 and the fuel cell 420 may be progressively started and supplied with hydrogen from the pipeline 300. The hydrogen pressure injected in the fuel cell 420 may be regulated by the pressure-reducing valve 430 in order to correspond to an acceptable pressure of the fuel cell 420. The fuel cell 420 may be controlled by the controller 410 to produce electrical power as long as the gas pressure P. in the pipeline 300 does not reach the fourth pressure value P4, the third pressure value P3, another predetermined pressure value and / or according to power demand on the power grid, as described with regard to the first embodiment.

[0058] In contrast, the gas pressure P. in the pipeline 300 may be below a third pressure value P3 (second scenario). The fuel cell 420 may be a regenerative fuel cell and hydrogen can be produced from electrical power of the power grid, of a renewable source or of a power storage and water, electrolyte or an organic solvent, and reintroduced in the pipeline, in order to increase gas pressure P. in the pipeline 100. The gas pressure P. may thus be increased, for example up to the third pressure P3.

[0059] For example, the regenerative fuel cell 420 may be provided with power and water and / or a proton-rich electrolyte such as HBR, HCl, HF, or an organic compound by the controller 410 and may start generating hydrogen. This hydrogen may be compressed by the compressor 440 in order to reach a pressure equal or higher than the pressure P. in the pipeline 300 and / or the third pressure value P3.

[0060] Both scenarios may be performed by the integrity preservation device 400. Alternatively, an integrity preservation device may perform the first scenario of reducing the gas pressure P. inside the pipeline and another integrity preservation device may perform the second scenario. In this case, the integrity preservation device may include a normal fuel cell and the another integrity preservation device may have a hydrogen producer different from a regenerative fuel cell, such as a water electrolyser, a methane reformer or an ammonia reformer.

[0061] Both integrity preservation devices may be integrated in the same facilities and share some tubing and control device. The pipeline transporting hydrogen and the integrity preservation device may form a hydrogen transportation system.

[0062] The first embodiment and the second embodiment described above both contribute to preserving integrity of a pipeline by actively limiting wall fatigue, with an improved efficiency and a small footprint. The first and second embodiments do not relate to emergency devices and methods but relate to a smart pipeline operating method and smart pipeline management device increasing the lifetime of a pipeline or pipeline section.

[0063] Although the present disclosure has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitations, the scope of the present disclosure being limited only by the terms of the appended claims.

Examples

first embodiment

[0041]A first embodiment of the above general method may be applied in the case of a pipeline 100 transporting any gas. For example, the gas may be carbon dioxide, oxygen, methane, nitrogen or argon. Fig. 2 shows an integrity preservation device 200 connected to a pipeline 100 transportation a gas such as carbon dioxide. The integrity preservation device 200 may comprise a controller 210, a compressor 220, a tank 230 for storing liquid or compressed gas and a decompressor unit or turbine 240 or alternatively a pressure relief valve. Preferably, the integrity preservation device 200 comprises a first heat exchanger 250, a heat energy storage 260 and a second heat exchanger 270.

[0042]The controller 210 may comprise one or several processors, memories, wired or wireless interfaces, input devices and / or displays and may control or at least monitor the above elements of the integrity preservation device 200 (not shown in Fig. 2). The controller 210 may run a controller program, for examp...

second embodiment

[0053]A second embodiment of the above general method may be applied in the case of a pipeline 300 transporting hydrogen. Fig. 4 shows a pipeline 300 transporting hydrogen and connected to an integrity preservation device 400. The integrity preservation device 400 is fluidly connected with the pipeline 100 through valves and tubing. It may include at least a controller 410 and a fuel cell 420, and optionally a pressure-reducing valve 430 and / or a compressor 440. The controller 410 may include one or several processors, memories, wired or wireless interfaces, input devices and / or displays and may control or at least monitor the above elements of the integrity preservation device 400. The controller 410 may be substantially similar to the controller 210 of the first embodiment.

[0054]An exemplary method of the present disclosure is shown in Fig. 4. According to the hydrogen or gas pressure or flow rate measured, predicted or estimated in the pipeline, different scenarios are possible. ...

Claims

1. A method to preserve integrity of a pipeline transporting a gas (100), wherein the pipeline (100) is connected to an integrity preservation device (200) comprising a compressor (220) and a tank (230), the method comprising: • Detecting (E1) or predicting a first situation in which a gas input in at least one section of the pipeline (100) is above a gas output out of said section; • When the first situation is detected or predicted, injecting (E2) gas from the pipeline (100) to the compressor (220); • Compressing or liquefying the injected gas with the compressor (220); • Storing (E2-1) the compressed or liquefied gas in the tank (230) as a stored gas.

2. The method of claim 1, wherein the integrity preservation device (200) includes a heat energy storage (260), the method comprising: • Recovering heat from the compressed or liquefied gas; • Storing the recovered heat in the heat energy storage (260).

3. The method of claim 1 or claim 2, wherein the integrity preservation device (200) includes a turbine (240), the method comprising: • Detecting (E1) or predicting a second situation in which a gas input in the same or another at least one section of the pipeline (100) is below a gas output out of the pipeline (100); • When the second situation is detected or predicted, decompressing the stored gas from the tank (230) in the turbine (240), • Generating electrical power with the turbine (240), • Injecting (E3-1) the decompressed gas into the pipeline (100).

4. An integrity preservation device (200) adapted to preserve integrity of a pipeline (100) transporting a gas, the integrity preservation device (200) being adapted to be connected to the pipeline (100), the integrity preservation device (200) comprising: • a compressor (220), • a tank (230) and • a controller (210) controlling the compressor (220) and the connection of the integrity preservation device (200) with the pipeline (100), wherein the controller (210) is configured to compress or liquefy gas from the pipeline (100) with the compressor (220) and to store it in the tank (230) as a stored gas, in a first situation in which a gas input in the pipeline (100) is detected or predicted above a gas output out of the pipeline (100).

5. The integrity preservation device of claim 4, comprising a pipeline monitoring device configured to detect or predict the first situation.

6. The integrity preservation device (200) of claim 4 or 5, comprising a heat energy storage (260), wherein the controller (210) is configured to recover heat from the compressed or liquefied gas circulating through a first heat exchanger (250) and / or through the heat energy storage (260) and to store it in the heat energy storage (260).

7. The integrity preservation device (200) of any of claims 4 to 6, wherein the integrity preservation device (200) comprises a turbine (240) controlled by the controller (210), and wherein the controller (210) is configured to decompress the stored gas in the turbine (240), to generate electrical power with the turbine (240) and to inject the decompressed gas into the pipeline (100), in a second situation in which a gas input in the pipeline (100) is below a gas output out of the pipeline (100).

8. The integrity preservation device (200) of claim 7 when it depends on claim 5, wherein the pipeline monitoring device is configured to detect or predict the second situation.

9. The integrity preservation device (200) of any of claims 6 to 8, wherein the controller (210) is configured to heat the stored gas with the heat energy stored in the heat energy storage (260) before decompressing the stored gas in the turbine (240).

10. A method to preserve integrity of a pipeline (300) transporting hydrogen, wherein an integrity preservation device (400) including a fuel cell (420) is connected to the pipeline (300), the method comprising: • Detecting (E1) or predicting a third situation in which a hydrogen input in the pipeline (300) is above a hydrogen output out of the pipeline (300); • When the third situation is detected or predicted, injecting (E2) hydrogen from the pipeline (300) to the fuel cell (420); • Consuming (E2-2) the injected hydrogen with the fuel cell (420) to generate electrical power.

11. The method of claim 10, wherein the fuel cell (420) is a regenerative fuel cell and / or the integrity preservation device includes an electrolyser, the method comprising: • Detecting (E1) or predicting a fourth situation in which a hydrogen input in the pipeline (300) is below a hydrogen output out of the pipeline (300); • When the fourth situation is detected or predicted, generating (E3-2) hydrogen by the regenerative fuel cell (420) and / or the electrolyser; • Injecting (E3) the generated hydrogen into the pipeline (300).

12. The method of claim 10, wherein the integrity preservation device (400) includes a reformer, the method comprising: • Detecting or predicting a fourth situation in which a hydrogen input in the pipeline (100) is below a hydrogen output out of the pipeline (100); • Generating hydrogen by the reformer; • Injecting the generated hydrogen into the pipeline (300).

13. An integrity preservation device (400) adapted to preserve integrity of a pipeline (300) transporting hydrogen, the integrity preservation device (400) being adapted to be connected to the pipeline (300), the integrity preservation device (400) including: • A fuel cell (420) connected to the pipeline (300), • A controller (410) controlling the fuel cell (420) and the connection of the integrity preservation device (400) with the pipeline (300); wherein, the controller (410) is configured to inject hydrogen from the pipeline (300) into the fuel cell (420) to generate electrical power with the fuel cell (420), in a third situation in which a hydrogen input in the pipeline (300) is detected or predicted above a hydrogen output out of the pipeline (300).

14. The integrity preservation device (400) of claim 13, wherein the fuel cell (420) is a regenerative fuel cell and / or the integrity preservation device (400) includes an electrolyser controlled by the controller (410), and wherein the controller (410) is configured to generate hydrogen by the regenerative fuel cell (420) and / or the electrolyser in a fourth situation in which a hydrogen input in the pipeline (100) is detected or predicted below a hydrogen output out of the pipeline (100).

15. The integrity preservation device (400) of claim 13, including a methane reformer controlled by the controller, and wherein the controller (410) is configured to generate hydrogen with the methane reformer in a fourth situation in which a hydrogen input in the pipeline (100) is detected or predicted below a hydrogen output out of the pipeline (100).

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