Multi-channel sensing device and method for deep-sea deformation stress monitoring

Abstract

The present invention discloses a multi-channel sensing device and method for deep-sea deformation and stress monitoring. The sensing device includes a housing, a differential pressure sensor, multiple sensing probes, a connecting pipe, multiple solenoid valves, and a pressure-conducting main pipe. The beneficial technical effect of the present invention is that a multi-channel sensing device and method for deep-sea deformation and stress monitoring are proposed. This solution can eliminate the influence of the background static pressure caused by the deep-sea water body on the detection signal, enabling us to measure tiny deformation stress under high water pressure conditions in the deep sea, and a single sensing device can monitor multiple parts.

Description

Technical Field

[0001] The present invention relates to a deep-sea pipeline online monitoring technology, and in particular to a multi-channel sensing device and method for deep-sea deformation stress monitoring. Background Art

[0002] As marine economic development gradually moves deeper into the deep sea, the demand for deep-sea structure monitoring continues to increase. Dynamic and static deformation stresses are gaining increasing attention because they are directly related to structural health and fatigue failure. Typical application scenarios include deep-sea oil and gas pipelines, FPSO oil and gas production platforms and their steel catenary risers (SCRs), and underwater cables used in deep-sea or offshore wind power platforms.

[0003] Currently, two common methods for detecting structural deformation in deep-sea environments are regular ROV inspections and fiber optic sensing. While regular ROV inspections don't require infrastructure, they can't achieve online, real-time monitoring and incur high labor and maintenance costs. While fiber optic sensing can achieve online, real-time monitoring, it carries high construction and equipment costs. More importantly, fiber optic sensing systems are significantly affected by vibration, making them unable to accurately measure deformation stress in dynamic environments. They are also susceptible to the influence of underwater currents and internal waves, resulting in a high false alarm rate.

[0004] The deformation and deformation stress detection methods used on land are mainly based on piezoelectric materials or strain materials. However, in the deep sea with high static pressure, land-based detection methods will be affected by the background water pressure and cannot measure tiny deformation stress. Summary of the Invention

[0005] In response to the problems in the background technology, the present invention proposes a multi-channel sensing device for deep-sea deformation and stress monitoring. Its innovation lies in: the sensing device includes a housing, a differential pressure sensor, multiple sensing probes, a connecting pipe, multiple solenoid valves and a pressure guide pipe;

[0006] The differential pressure sensor and the solenoid valve are encapsulated in the housing;

[0007] The sensing probe is composed of a sensing hard tube and a pressure branch pipe; the sensing hard tube is a single-port tube, the port of the sensing hard tube is connected to the outer port of the pressure branch pipe, the inner port of the pressure branch pipe is connected to the pressure main pipe through an electromagnetic valve, and multiple pressure branch pipes correspond to multiple electromagnetic valves one by one; the pressure main pipe is connected to the first input port of the differential pressure sensor; the sensing hard tube is placed outside the shell, and the pressure main pipe is placed inside the shell; the sensing hard tube, the pressure branch pipe and the pressure main pipe are filled with liquid pressure medium; a through hole matching the pressure branch pipe is provided on the shell, and the middle part of the pressure branch pipe is connected to the through hole through a connector one; the multiple pressure branch pipes correspond to multiple connectors one respectively;

[0008] The inner port of the connecting tube is connected to the second input port of the differential pressure sensor, and the outer port of the connecting tube is placed outside the shell; a through hole matching the connecting tube is provided on the shell, and the middle part of the connecting tube is connected to the through hole through connector 2.

[0009] The role of the housing is to isolate the seawater, bear the deep sea pressure, and protect the differential pressure sensor. In specific implementation, it should be made of a material with a certain strength and resistance to seawater corrosion;

[0010] The sensor probe is fixed on the structure to sense the deformation of the structure. When the structure deforms, the sensor probe is also forced to deform, thereby changing the pressure of the internal liquid pressure-conducting medium.

[0011] The pressure guiding pipe is used to connect the sensing probe and the first input port of the differential pressure sensor;

[0012] The connecting pipe is used to connect the external environmental water body and the second input port of the differential pressure sensor;

[0013] The differential pressure sensor is used to obtain the pressure difference sensed by the first input port and the second input port.

[0014] The connector has the functions of sealing, connecting and supporting, and can be selected from the existing technologies.

[0015] The solenoid valve is used to control the on and off of the corresponding pressure-conducting main pipe, and the switching of multiple sensing probes is achieved through multiple solenoid valves; the solenoid valve is a normally closed solenoid valve that is opened only when power is turned on.

[0016] Preferably, the sensing hard tube is made of titanium-based metal, high silicon cast iron or vulcanized rubber.

[0017] Based on the above solution, the present invention also proposes a method for monitoring deformation stress of deep-sea pipelines. The hardware involved includes a sensing device and a processing device. The structure of the sensing device is as described above. The output of the differential pressure sensor is connected to the processing device via an electrical cable. The control unit of the solenoid valve is connected to the processing device via an electrical cable. The specific method includes:

[0018] A portion of the plurality of sensor probes is designated as first sensor probes, and another portion is designated as second sensor probes; the first sensor probes are arranged according to the first method, and the second sensor probes are arranged according to the second method; and the housing is fixed to the outer wall of the deep-sea pipeline;

[0019] After the sensor probe is put into operation, the processing device periodically connects one of the multiple pressure branch pipes to the first input port of the differential pressure sensor through the solenoid valve. Simultaneously, the processing device identifies the output signal of the differential pressure sensor. If the output signal of the differential pressure sensor exceeds a set threshold, it indicates that deformation has occurred in the corresponding part of the deep-sea pipeline.

[0020] The first method includes: the sensing rigid tube corresponding to the first sensing probe is recorded as the first rigid tube; the deep-sea pipeline is formed by connecting multiple pipelines; a first rigid tube is set at the connection between every two adjacent pipelines; when a single first rigid tube is set, the first rigid tube is set on the outer wall of the deep-sea pipeline corresponding to the interface between the two pipelines, the first rigid tube intersects with the plane where the interface between the two pipelines is located, the left section of the first rigid tube is fixed to the outer wall of the deep-sea pipeline by a first clamp, and the right section of the first rigid tube is fixed to the outer wall of the deep-sea pipeline by a second clamp, and the interface between the two pipelines is located between the first clamp and the second clamp;

[0021] The second method includes: the sensing rigid pipe corresponding to the second sensing probe is recorded as the second rigid pipe; the second rigid pipe is L-shaped; the deep-sea pipeline includes a main pipe and multiple branch pipes connected to the main pipe; the connection between the main pipe and the branch pipe forms a monitoring point, and a second rigid pipe is set at each monitoring point; when a single second rigid pipe is set, the vertical section of the second rigid pipe is fixed to the outer wall of the branch pipe by a first clamp, and the horizontal section of the second rigid pipe is fixed to the outer wall of the main pipe by a second clamp.

[0022] The principle of the above scheme is:

[0023] Traditional deformation and deformation stress detection methods mainly use piezoelectric materials or strain materials, which are not suitable for deep-sea conditions with great depth and high static pressure. The main reason is that under deep-sea conditions, the detection signals that can be obtained by traditional methods include the background static pressure caused by the deep-sea water body, sensor noise and the actual strain of the structure. Since the background static pressure caused by the deep-sea water body is much larger than the actual strain of the structure (usually, the deformation process of deep-sea pipelines is relatively slow, and the stress changes are also slow), and the sensor noise is proportional to the background static pressure, this will cause the sensor noise to be close to the actual strain of the structure, thereby seriously affecting the dynamic range and accuracy of the sensing device.

[0024] The idea of ​​the present invention is:

[0025] After the sensing device is put into operation, when the pressure branch pipe and differential pressure sensor corresponding to a certain sensing probe are selected, if the monitoring part corresponding to the sensing probe does not deform, the signal corresponding to the first input port measured by the differential pressure sensor is "background static pressure A + sensor noise A". At the same time, the signal corresponding to the second input port is "background static pressure B + sensor noise B". Since the sensing hard pipe, pressure pipe and connecting pipe are all at the same depth in the sea, the background static pressure caused by the water pressure is the same. Therefore, "background static pressure A = background static pressure B". Since it is the same differential pressure sensor, the sensor noise corresponding to the two input ports is the same, so "sensor noise A = sensor noise B". At this time, through the processing of the differential pressure sensor, the signals corresponding to the two input ports cancel each other out, and the final output signal is "0";

[0026] When the corresponding monitored part deforms, the two parts of the sensing tube, fixed to the outer wall of the deep-sea pipeline by two clamps, will move separately under the action of the two clamps, causing the sensing tube to deform and squeezing the liquid pressure-conducting medium within the sensing tube. At this time, the signal corresponding to the first input port measured by the differential pressure sensor is "background static pressure A + sensor noise A + sensing induced force" (the sensing induced force is the force generated by the squeezing of the liquid pressure-conducting medium). The signal corresponding to the second input port is still "background static pressure B + sensor noise B". As mentioned above, since the background static pressure and sensor noise corresponding to the two input ports can cancel each other out, the final output signal of the differential pressure sensor is the "sensing induced force". Based on the "sensing induced force" and its value, we can determine whether the corresponding part has deformed and the severity of the deformation, thereby realizing online real-time monitoring of the deep-sea pipeline. After adopting the solution of the present invention, the background static pressure and sensor noise caused by deep-sea high water pressure can be self-cancelled, solving the problem that the existing technology cannot measure tiny deformation stress under deep-sea high water pressure conditions.

[0027] The installation locations of the sensing rigid pipes mentioned in the aforementioned methods 1 and 2 are common structures on deep-sea pipelines. For method 1, when the deep-sea pipeline is deformed under external forces, due to the good structural strength of a single pipeline, the deformation usually first occurs at the connection between adjacent pipelines, so the sensing rigid pipe is set at the pipeline interface; for method 2, similar to the idea of ​​method 1, since the vertical section and horizontal section of the sensing rigid pipe are respectively fixed on the main pipe and branch pipe, when the connection between the main pipe and the branch pipe is bent, the vertical section and horizontal section of the sensing rigid pipe will move with the main pipe and branch pipe respectively, thereby causing the sensing rigid pipe to deform.

[0028] Together with the present application, the applicant has also separately proposed technical solutions for Method 1 and Method 2, and has filed separate applications. Unlike the separate applications, the present invention is equipped with multiple sensor probes on a single sensor device, and switches the multiple sensor probes through an electromagnetic valve. The application scenarios it targets are mainly situations where the pipelines are concentrated and complex. In this scenario, a single sensor device can monitor multiple parts.

[0029] The beneficial technical effect of the present invention is: a multi-channel sensing device and method for deep-sea deformation stress monitoring are proposed, which can eliminate the influence of the background static pressure caused by the deep-sea water body on the detection signal, so that we can measure tiny deformation stress under high water pressure conditions in the deep sea, and a single sensing device can monitor multiple parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 , schematic diagram of the structure of the multi-channel sensing device;

[0031] Figure 2 ,Schematic diagram of the arrangement structure of the sensing hard pipe under method 1 (the dotted line in the figure is the pipe interface);

[0032] Figure 3 , schematic diagram of the sensing tube in a deformed state under method 1;

[0033] Figure 4 , schematic diagram of the arrangement structure of the sensing hard tube in the second mode;

[0034] Figure 5 , schematic diagram of the sensing tube in a deformed state under the second method;

[0035] The names corresponding to the various marks in the figure are: housing 1, differential pressure sensor 2, sensing hard tube 3, pressure branch pipe 4, connecting pipe 5, solenoid valve 6, pressure main pipe 7. DETAILED DESCRIPTION

[0036] A multi-channel sensing device for deep-sea deformation and stress monitoring, the innovation of which is that: the sensing device includes a housing 1, a differential pressure sensor 2, multiple sensing probes, a connecting pipe 5, multiple solenoid valves 6 and a pressure guide pipe 7;

[0037] The differential pressure sensor 2 and the solenoid valve 6 are encapsulated in the housing 1;

[0038] The sensing probe is composed of a sensing hard tube 3 and a pressure-guiding branch tube 4; the sensing hard tube 3 is a single-port tube, the port of the sensing hard tube 3 is connected to the outer port of the pressure-guiding branch tube 4, the inner port of the pressure-guiding branch tube 4 is connected to the pressure-guiding main tube 7 through an electromagnetic valve 6, and multiple pressure-guiding branch tubes 4 correspond one to one with multiple electromagnetic valves 6; the pressure-guiding main tube 7 is connected to the first input port of the differential pressure sensor 2; the sensing hard tube 3 is placed outside the housing 1, and the pressure-guiding main tube 7 is placed inside the housing 1; the sensing hard tube 3, the pressure-guiding branch tube 4 and the pressure-guiding main tube 7 are filled with liquid pressure-guiding medium; a through hole matching the pressure-guiding branch tube 4 is provided on the housing 1, and the middle part of the pressure-guiding branch tube 4 is connected to the through hole through a connector 1; the multiple pressure-guiding branch tubes 4 correspond to multiple connectors 1 respectively;

[0039] The inner port of the connecting tube 5 is connected to the second input port of the differential pressure sensor 2, and the outer port of the connecting tube 5 is placed outside the shell 1; a through hole matching the connecting tube 5 is provided on the shell 1, and the middle part of the connecting tube 5 is connected to the through hole through connector 2.

[0040] Furthermore, the material of the sensing hard tube 3 is titanium-based metal, high silicon cast iron or vulcanized rubber.

[0041] A method for monitoring deformation stress of deep-sea pipelines, the hardware involved includes a sensing device and a processing device; the sensing device includes a housing 1, a differential pressure sensor 2, multiple sensing probes, a connecting pipe 5, multiple solenoid valves 6 and a pressure guide pipe 7;

[0042] The differential pressure sensor 2 and the solenoid valve 6 are encapsulated in the housing 1;

[0043] The sensing probe is composed of a sensing hard tube 3 and a pressure-guiding branch tube 4; the sensing hard tube 3 is a single-port tube, the port of the sensing hard tube 3 is connected to the outer port of the pressure-guiding branch tube 4, the inner port of the pressure-guiding branch tube 4 is connected to the pressure-guiding main tube 7 through an electromagnetic valve 6, and multiple pressure-guiding branch tubes 4 correspond one to one with multiple electromagnetic valves 6; the pressure-guiding main tube 7 is connected to the first input port of the differential pressure sensor 2; the sensing hard tube 3 is placed outside the housing 1, and the pressure-guiding main tube 7 is placed inside the housing 1; the sensing hard tube 3, the pressure-guiding branch tube 4 and the pressure-guiding main tube 7 are filled with liquid pressure-guiding medium; a through hole matching the pressure-guiding branch tube 4 is provided on the housing 1, and the middle part of the pressure-guiding branch tube 4 is connected to the through hole through a connector 1; the multiple pressure-guiding branch tubes 4 correspond to multiple connectors 1 respectively;

[0044] The inner port of the connecting tube 5 is connected to the second input port of the differential pressure sensor 2, and the outer port of the connecting tube 5 is placed outside the housing 1; the housing 1 is provided with a through hole matching the connecting tube 5, and the middle part of the connecting tube 5 is connected to the through hole through the second connector;

[0045] The output portion of the differential pressure sensor 2 is connected to the processing device via an electrical cable; the control portion of the solenoid valve 6 is connected to the processing device via an electrical cable;

[0046] Its innovation lies in that the method comprises:

[0047] A portion of the plurality of sensor probes is referred to as the first sensor probe, and another portion is referred to as the second sensor probe; the first sensor probes are arranged according to the first method, and the second sensor probes are arranged according to the second method; the housing 1 is fixed to the outer wall of the deep-sea pipeline;

[0048] After the sensor probe is put into operation, the processing device periodically connects one of the multiple pressure-guiding branches 4 to the first input port of the differential pressure sensor 2 through the solenoid valve 6. Simultaneously, the processing device identifies the output signal of the differential pressure sensor 2. If the output signal of the differential pressure sensor 2 exceeds the set threshold, it indicates that deformation has occurred in the corresponding part of the deep-sea pipeline.

[0049] The first method includes: the sensing rigid tube 3 corresponding to the first sensing probe is recorded as the first rigid tube; the deep-sea pipeline is formed by connecting multiple pipelines; a first rigid tube is set at the connection between every two adjacent pipelines; when a single first rigid tube is set, the first rigid tube is set on the outer wall of the deep-sea pipeline corresponding to the interface between the two pipelines, the first rigid tube intersects with the plane where the interface between the two pipelines is located, the left section of the first rigid tube is fixed to the outer wall of the deep-sea pipeline by a first clamp, and the right section of the first rigid tube is fixed to the outer wall of the deep-sea pipeline by a second clamp, and the interface between the two pipelines is located between the first clamp and the second clamp;

[0050] The second method includes: the sensing rigid tube 3 corresponding to the second sensing probe is recorded as the second rigid tube; the second rigid tube is L-shaped; the deep-sea pipeline includes a main tube and multiple branch tubes connected to the main tube; the connection between the main tube and the branch tube forms a monitoring point, and a second rigid tube is set at each monitoring point; when a single second rigid tube is set, the vertical section of the second rigid tube is fixed to the outer wall of the branch tube by a first clamp, and the horizontal section of the second rigid tube is fixed to the outer wall of the main tube by a second clamp.

Claims

1. A method for monitoring deformation stress of a deep-sea pipeline, the hardware involved comprising a sensing device and a processing device; the sensing device comprising a housing (1), a differential pressure sensor (2), a plurality of sensing probes, a connecting pipe (5), a plurality of solenoid valves (6) and a pressure guide pipe (7); The differential pressure sensor (2) and the solenoid valve (6) are encapsulated in the housing (1); The sensing probe is composed of a sensing hard tube (3) and a pressure branch tube (4); the sensing hard tube (3) is a single-port tube, the port of the sensing hard tube (3) is connected to the outer port of the pressure branch tube (4), the inner port of the pressure branch tube (4) is connected to the pressure main tube (7) through the electromagnetic valve (6), and the multiple pressure branch tubes (4) correspond to the multiple electromagnetic valves (6) one by one; the pressure main tube (7) is connected to the first input port of the differential pressure sensor (2); the sensing hard tube (3) is placed outside the shell (1), and the pressure main tube (7) is placed inside the shell (1); the sensing hard tube (3), the pressure branch tube (4) and the pressure main tube (7) are filled with liquid pressure medium; a through hole matching the pressure branch tube (4) is provided on the shell (1), and the middle part of the pressure branch tube (4) is connected to the through hole through a connector one; the multiple pressure branch tubes (4) correspond to the multiple connectors one respectively; The inner port of the connecting tube (5) is connected to the second input port of the differential pressure sensor (2), and the outer port of the connecting tube (5) is placed outside the housing (1); a through hole matching the connecting tube (5) is provided on the housing (1), and the middle portion of the connecting tube (5) is connected to the through hole via a second connector; The output portion of the differential pressure sensor (2) is connected to the processing device via an electrical cable; The control unit of the solenoid valve (6) is connected to the processing device via an electrical cable; Its characteristics are: The method comprises: A portion of the plurality of sensor probes is recorded as a first sensor probe, and another portion is recorded as a second sensor probe; the first sensor probes are arranged according to the first method, and the second sensor probes are arranged according to the second method; the housing (1) is fixed on the outer wall of the deep-sea pipeline; After the sensing probe is put into operation, the processing device periodically connects one of the plurality of pressure-guiding branches (4) to the first input port of the differential pressure sensor (2) through the electromagnetic valve (6). Synchronously, the processing device identifies the output signal of the differential pressure sensor (2). If the output signal of the differential pressure sensor (2) exceeds a set threshold, it indicates that deformation has occurred at the corresponding portion of the deep-sea pipeline. The method 1 includes: the sensing hard pipe (3) corresponding to the first sensing probe is recorded as the first hard pipe; the deep-sea pipeline is formed by connecting multiple pipelines; a first hard pipe is set at the connection between each two adjacent pipelines; when a single first hard pipe is set, the first hard pipe is set on the outer wall of the deep-sea pipeline corresponding to the position of the interface between the two pipelines, the first hard pipe intersects with the plane where the interface between the two pipelines is located, the left section of the first hard pipe is fixed to the outer wall of the deep-sea pipeline by a first clamp, and the right section of the first hard pipe is fixed to the outer wall of the deep-sea pipeline by a second clamp, and the interface between the two pipelines is located between the first clamp and the second clamp; The second method includes: the sensing hard pipe (3) corresponding to the second sensing probe is recorded as the second hard pipe; the second hard pipe is L-shaped; the deep-sea pipeline includes a main pipe and a plurality of branch pipes connected to the main pipe; the connection between the main pipe and the branch pipe forms a monitoring point, and a second hard pipe is set at each monitoring point; when a single second hard pipe is set, the vertical section of the second hard pipe is fixed to the outer wall of the branch pipe through the first clamp, and the horizontal section of the second hard pipe is fixed to the outer wall of the main pipe through the second clamp.

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