Monitoring and early warning system for scouring depth and scouring pit form of offshore wind turbine pile foundation

Abstract

The invention discloses an offshore wind turbine pile foundation scour depth and scour pit form monitoring and early warning system, and relates to the field of offshore wind power engineering, the system comprises a magnetic label stone, a magnetic gradiometer, a data processing analyzer and a scour early warning unit, the magnetic label stone is arranged on the seabed ground around a wind turbine pile foundation, and the magnetic gradiometer is arranged on the data processing analyzer; the magnetic gradiometer is used for monitoring the magnetic field gradient change of a scouring pit interface in real time, the data processing and analyzing device is used for receiving real-time magnetic field gradient information transmitted by the magnetic gradiometer, and the change of a three-dimensional displacement field of the magnetic label stone is inverted through the change of the magnetic field gradient, so that dynamic monitoring of local scouring of the pile foundation is achieved. The scouring early warning unit is used for monitoring and predicting the depth and the shape of a scouring pit and giving an alarm; the device is simple in structure, convenient to install and easy to operate, the influence of severe marine environment factors on scour monitoring is overcome, and large-range scour real-time monitoring around the fan foundation can be achieved by arranging the magnetic label stones on a large scale.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power engineering, and in particular to an offshore wind turbine pile foundation scour depth and scour pit morphology monitoring and early warning system. Background Art

[0002] Offshore wind power has developed rapidly in recent years due to its advantages such as high wind speed, long effective power generation hours, and no occupation of land resources. However, offshore wind turbine pile foundations are affected by the complex hydrodynamic environment of the ocean, and scour is easily generated around the pile foundation, resulting in reduced bearing capacity of the pile body, tilting of the foundation, and even serious consequences such as the overall collapse of the wind turbine. Therefore, monitoring and early warning of the local scour depth and scour pit morphology of offshore wind turbine pile foundations is crucial.

[0003] At present, the detection of pile foundation scour mainly adopts ship-borne multi-beam sonar system to conduct regular sea sweeping, which is expensive and cannot achieve real-time monitoring. The real-time changes of scour depth and the maximum scour depth monitored are limited, and the real-time performance and accuracy are poor. At the same time, when encountering extreme and harsh marine environments, scour detection operations cannot be carried out, and this is exactly when scour is the most serious. This leaves loopholes and hidden dangers for the safety of offshore wind turbine pile foundations. Summary of the invention

[0004] The present invention provides a monitoring and early warning system for the scour depth and scour pit morphology of offshore wind turbine pile foundations. The present invention has a simple structure, is easy to install, and is simple to operate. It overcomes the influence of harsh marine environmental factors on scour monitoring, and can achieve real-time monitoring of scour in a large area around the wind turbine foundation by large-scale deployment of magnetic label stones.

[0005] To achieve the above object, the present invention provides the following technical solutions: A monitoring and early warning system for the scour depth and scour pit morphology of an offshore wind turbine pile foundation, the system comprising magnetically tagged stones, a magnetic gradiometer, a data processing and analyzing instrument, and a scour early warning unit. The magnetically tagged stones can be evenly arranged in a grid on the seabed around the wind turbine pile foundation according to the scour detection resolution requirements. The magnetic gradiometer is arranged on the outer peripheral surface of the wind turbine pile foundation, receives magnetic field information from the scour pit interface, and is used to monitor the magnetic field gradient changes of the scour pit interface in real time. The data processing and analyzing instrument is installed on the wind turbine platform, and can receive the real-time magnetic field gradient information transmitted by the magnetic gradiometer, and invert the changes in the three-dimensional displacement field of the magnetically tagged stones through the changes in the magnetic field gradient, thereby realizing dynamic monitoring of local scour of the pile foundation. The scour early warning unit is used to monitor and predict the depth and shape of the scour pit and issue an alarm.

[0006] As a preferred embodiment of the present invention, the magnetically labeled stone comprises an internal ferromagnetic material sensing unit and an externally coated prefabricated concrete block.

[0007] As a preferred embodiment of the present invention, a plurality of magnetic label stones are provided, and the magnetic label stones are densely laid in a grid pattern around the wind turbine pile foundation pit. The vertical and horizontal spacing of the magnetic label stones is D. The length, width and height of each magnetic label stone is 18cm×18cm×18cm, and the magnetic field strength is marked as H.

[0008] As a preferred embodiment of the present invention, the magnetic field intensity monitored by the magnetic gradiometer is , and the magnetic field strength of any magnetic tag stone is , where k is a constant and h is the height position of the magnetically labeled stone; The magnetic gradiometer records the difference P in magnetic field strength between the highest magnetically tagged stone and the lowest magnetically tagged stone. The calculation formula for the difference P in magnetic field strength is as follows: , in is the height position of the lowest magnetic tag stone. It is the height position of the highest magnetic tag stone.

[0009] As a preferred embodiment of the present invention, the specific processing method of the data processing and analyzing instrument comprises the steps of: Calculate the rate of change β of magnetic field intensity under height difference, the calculation formula is as follows: , in, The initial magnetic field strength difference of the stone where the magnetic tag is placed. It is the difference in magnetic field strength after placing the magnetic tag stone for a period of time; Set the standard change value and calculate the difference between the standard change value and the change rate.

[0010] As a preferred solution of the present invention, the flushing warning unit includes a data receiving interface, a data processing interface, a PLC control module and an alarm. The data receiving interface receives the difference between the calculated standard change value and the change rate derived from the data processing analyzer, and compares the difference with the threshold of the PLC control module through the data processing interface. After exceeding the threshold, the PLC control module stimulates an electrical signal to control the alarm to turn on.

[0011] In summary, the beneficial technical effects of the present invention are as follows: the present invention sets a number of magnetic label stones, and when scour changes occur on the seabed surface, the spatial three-dimensional position of the magnetic label stones arranged on the seabed surface will change. The magnetic gradiometer can invert the changes in the three-dimensional displacement field of the magnetic label stones by monitoring the changes in the magnetic field gradient around the pile foundation, thereby realizing dynamic monitoring of local scour of the pile foundation. This method is simple to operate and has stable performance. It overcomes the influence of harsh marine environmental factors on scour monitoring. By deploying magnetic label stones on a large scale, large-scale scour monitoring around the wind turbine foundation can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of a scour depth and scour pit morphology monitoring and early warning system for offshore wind turbine pile foundations according to the present embodiment. DETAILED DESCRIPTION

[0013] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] See also Figure 1 The present invention provides a technical solution: a monitoring and early warning system for the scour depth and scour pit morphology of an offshore wind turbine pile foundation, the system comprising magnetic label stones, a magnetic gradiometer, a data processing and analysis instrument and a scour early warning unit, the magnetic label stones can be evenly arranged in a grid on the seabed around the wind turbine pile foundation according to the scour detection resolution requirements, the magnetic gradiometer is arranged on the outer peripheral surface of the wind turbine pile foundation, receives magnetic field information from the scour pit interface, and is used to monitor the magnetic field gradient changes of the scour pit interface in real time, the data processing and analysis instrument is installed on the wind turbine platform, and can receive the real-time magnetic field gradient information transmitted by the magnetic gradiometer, and invert the changes in the three-dimensional displacement field of the magnetic label stones through the changes in the magnetic field gradient, thereby realizing dynamic monitoring of local scour of the pile foundation, and the scour early warning unit is used to monitor and predict the depth and shape of the scour pit and issue an alarm.

[0016] The magnetic tag stone includes an internal ferromagnetic material sensor unit and an externally coated precast concrete block.

[0017] A number of magnetic label stones are set up and laid closely in a grid pattern around the wind turbine pile foundation pit. The vertical and horizontal spacing of the magnetic label stones is D. The length, width and height of each magnetic label stone is 18cm×18cm×18cm, and the magnetic field strength is marked as H.

[0018] The magnetic field intensity monitored by the magnetic gradiometer is , and the magnetic field strength of any magnetic tag stone is , where k is a constant and h is the height position of the magnetically labeled stone; The magnetic gradiometer records the difference P in magnetic field strength between the highest magnetically tagged stone and the lowest magnetically tagged stone. The calculation formula for the difference P in magnetic field strength is as follows: ,in is the height position of the lowest magnetic tag stone. It is the height position of the highest magnetic tag stone.

[0019] At the same time, the specific processing method of the data processing analyzer includes the following steps: To calculate the rate of change of magnetic field intensity under height difference, β, the following formula is used: ,in, The initial magnetic field strength difference of the stone where the magnetic tag is placed. It is the difference in magnetic field strength after placing the magnetic tag stone for a period of time; Set the standard change value A, and calculate the difference a between the standard change value A and the change rate β, where a=A-β.

[0020] The flushing warning unit includes a data receiving interface, a data processing interface, a PLC control module and an alarm. The data receiving interface receives the difference a between the calculated standard change value A and the change rate β derived from the data processing analyzer, and compares the difference with the threshold θ of the PLC control module through the data processing interface. After exceeding the threshold, the PLC control module stimulates an electrical signal to control the alarm to turn on.

[0021] In this embodiment, the magnetic label stone is based on the existing technology, which uses a sensor with self-sensing characteristics and uses ferromagnetic materials as sensor elements to be embedded in natural stones or prefabricated concrete blocks for packaging.

[0022] When the seabed surface is eroded, the spatial three-dimensional position of the magnetic tag stones arranged on the seabed surface will change. The magnetic gradiometer can invert the changes in the three-dimensional displacement field of the magnetic tag stones by monitoring the changes in the magnetic field gradient around the pile foundation, thereby realizing dynamic monitoring of local erosion of the pile foundation.

Claims

1. A monitoring and early warning system for the scour depth and scour pit morphology of offshore wind turbine pile foundations, characterized in that: The system includes magnetically tagged stones, a magnetic gradiometer, a data processing and analyzing instrument, and a scour warning unit. The magnetically tagged stones can be evenly arranged in a grid on the seabed around the wind turbine pile foundation according to the scour detection resolution requirements. The magnetic gradiometer is arranged on the outer peripheral surface of the wind turbine pile foundation to receive magnetic field information from the scour pit interface for real-time monitoring of the magnetic field gradient changes at the scour pit interface. The data processing and analyzing instrument is installed on the wind turbine platform and can receive the real-time magnetic field gradient information transmitted by the magnetic gradiometer. The changes in the three-dimensional displacement field of the magnetically tagged stones are inverted through the changes in the magnetic field gradient, thereby realizing dynamic monitoring of local scour of the pile foundation. The scour warning unit is used to monitor and predict the depth and shape of the scour pit and issue an alarm.

2. The offshore wind turbine pile foundation scour depth and scour pit morphology monitoring and early warning system according to claim 1 is characterized by: A plurality of magnetic label stones are provided, and the magnetic label stones are densely laid in a grid pattern around the wind turbine pile foundation pit. The vertical and horizontal spacing of the magnetic label stones is D. The length, width and height of each magnetic label stone is 18cm×18cm×18cm, and the magnetic field strength is marked as H.

3. The offshore wind turbine pile foundation scour depth and scour pit morphology monitoring and early warning system according to claim 2 is characterized by: The magnetic label stone comprises an internal ferromagnetic material sensing unit and an externally coated prefabricated concrete block.

4. The offshore wind turbine pile foundation scour depth and scour pit morphology monitoring and early warning system according to claim 3 is characterized by: The magnetic field strength monitored by the magnetic gradiometer is , and the magnetic field strength of any magnetic tag stone is , where k is a constant and h is the height position of the magnetically tagged stone.

5. The offshore wind turbine pile foundation scour depth and scour pit morphology monitoring and early warning system according to claim 4 is characterized by: The magnetic gradiometer records the difference P of the magnetic field strength between the highest magnetically tagged stone and the lowest magnetically tagged stone. The calculation formula of the magnetic field strength difference P is as follows: ,in, is the height position of the lowest magnetic tag stone. It is the height position of the highest magnetic tag stone.

6. The offshore wind turbine pile foundation scour depth and scour pit morphology monitoring and early warning system according to claim 5 is characterized by: The specific processing method of the data processing and analyzing instrument comprises the following steps: Calculate the rate of change β of magnetic field intensity under height difference, the calculation formula is as follows: ,in, The initial magnetic field strength difference of the stone where the magnetic tag is placed. It is the difference in magnetic field strength after placing the magnetic tag stone for a period of time; Set the standard change value A, and calculate the difference a between the standard change value A and the change rate β, where a=A-β.

7. The offshore wind turbine pile foundation scour depth and scour pit morphology monitoring and early warning system according to claim 6 is characterized by: The flushing warning unit includes a data receiving interface, a data processing interface, a PLC control module and an alarm. The data receiving interface receives the difference a between the calculated standard change value A and the change rate β derived from the data processing analyzer, and compares the difference with the threshold θ of the PLC control module through the data processing interface. After exceeding the threshold, the PLC control module excites an electrical signal to control the alarm to turn on.

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