Spar platform parameter resonance prediction device and method based on analog circuit

Abstract

The present invention discloses a Spar platform parameter resonance prediction device and method based on analog circuits, which solve the problem that irregular wave impacts easily cause platform pitch shaking, which in turn leads to safety accidents. The key points of the technical solution are that it includes a device body, an external sensor system for collecting heaving motion information, and an analog operation circuit arranged inside the device body for simulating parameters. The device body is provided with a plurality of parameter input terminals for inputting platform inherent parameters and heaving motion information parameters collected by the sensor system, a plurality of adjustment knobs for adjusting the platform inherent parameters, a display screen for displaying the processing output results, and a warning module for warning when resonant motion is predicted. The Spar platform parameter resonance prediction device and method based on analog circuits of the present invention can perform real-time monitoring and prediction, improve the dynamic performance and response of the Spar platform, and increase the overall safety and stability.

Description

Technical Field

[0001] The invention relates to a deep sea platform device, and in particular to a Spar platform parameter resonance prediction device based on an analog circuit and a method thereof. Background Art

[0002] With the further improvement of production technology and the further development of production equipment, the exploration of global marine oil and gas resources has gradually shifted from shallow waters to deep seas. After long-term exploration and development on land and shallow seas around the world, the possibility of discovering major oil fields has become smaller and smaller, and the scale has gradually decreased. Deep waters have become an important successor area for global resources, and going to the deep sea has become an inevitable national strategy.

[0003] In deep-sea oilfield exploitation, Spar platforms can be used as the main floating structure for operation. Spar platforms are easy to install and reuse, and their buoyancy center is higher than their gravity center. Compared with other platforms, their pitching motion is smaller. However, when subjected to long-term impact of irregular waves, Spar platforms will also produce large pitching motions, causing instability of the platform, resulting in damage to equipment and casualties of workers, and overall there are safety hazards. Summary of the invention

[0004] The purpose of the present invention is to provide a Spar platform parameter resonance prediction device and method based on analog circuits, which can perform real-time monitoring and prediction, improve the dynamic performance and response of the Spar platform, and increase overall safety and stability.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A Spar platform parameter resonance prediction device based on analog circuits, comprising a device body, an external sensor system for collecting heave motion information, and an analog operation circuit arranged inside the device body for analog processing of parameters;

[0007] The device body is provided with a plurality of parameter input terminals for inputting the platform inherent parameters and the heave motion information parameters collected by the sensor system, a plurality of adjustment knobs for adjusting the platform inherent parameters, a display screen for displaying the processing output results, and a warning module for issuing a warning when resonant motion is predicted to occur.

[0008] Preferably, the platform inherent parameters include a damping coefficient and a natural frequency of pitch motion; the heave motion information includes heave motion and heave motion frequency; the parameter input terminal is provided with four terminals for inputting the natural frequency of pitch motion, heave motion, heave motion frequency and platform damping coefficient respectively.

[0009] As a preferred embodiment, the pitch motion expression under irregular waves is:

[0010]

[0011] Among them, u5 represents the amplitude of the pitch angle changing with time τ, c5 represents the damping during the pitch motion, represents the pitch restoring force, where ω 50 is the natural frequency of pitch motion, represents the heave motion, ω i is the heaving motion frequency.

[0012] Preferably, the analog operation circuit includes a first multiplication unit, a second multiplication unit, a first division unit, a second division unit, a first proportional amplifier, a second proportional amplifier, a third multiplication unit, a fourth multiplication unit, an addition unit, a first first integration unit, a second first integration unit, and a third proportional amplifier;

[0013] The first multiplication unit is coupled to the parameter input terminal to receive the input natural frequency of the pitch motion, the second multiplication unit is coupled to the parameter input terminal to receive the input frequency of the heave motion, the first division unit is coupled to the output ends of the first multiplication unit and the second multiplication unit, the second division unit is coupled to the parameter input terminal for receiving the heave motion and the output end of the second multiplication unit, the first proportional amplifier is coupled to the first division unit, and the second proportional amplifier is coupled to the second division unit;

[0014] One of the input terminals of the third multiplication unit is coupled to the output terminal of the first proportional amplifier, and the other input terminal is coupled to the output terminal of the second first-time integration unit; one of the input terminals of the fourth multiplication unit is coupled to the output terminal of the second proportional amplifier, and the other input terminal is coupled to the output terminal of the second first-time integration unit;

[0015] The addition unit is coupled to the output end of the third multiplication unit, the fourth multiplication unit and the third proportional amplifier, the first first-time integration unit is coupled to the output end of the addition unit, and the second first-time integration unit is coupled to the output end of the first first-time integration unit; the third proportional amplifier is coupled to the output end of the first first-time integration unit, and the second first-time integration unit outputs the final simulation operation result.

[0016] Preferably, the adjusting knob includes a first adjusting knob and a second adjusting knob, the adjustment amount of the first adjusting knob corresponds to the amplification factor of the first proportional amplifier, the adjustment amount of the second adjusting knob corresponds to the amplification factor of the second proportional amplifier, and the damping coefficient input by the input terminal corresponds to the amplification factor of the third proportional amplifier.

[0017] A method for predicting the resonance of Spar platform parameters based on analog circuits includes the following steps:

[0018] The sensor system detects the heave motion and heave motion frequency of the platform and inputs them into the corresponding parameter input terminal of the device body;

[0019] Input the damping coefficient of the platform and the natural frequency of the pitch motion into the corresponding parameter input terminals of the device body;

[0020] The amplification factor is obtained by calculation and processing based on the pitch motion expression under irregular waves and the platform structural parameters, and the proportional amplification adjustment is completed by controlling the adjustment knob;

[0021] The device is started to perform real-time calculation processing through an analog calculation circuit, output the prediction result of the next moment to the display screen for display, and issue a warning reminder when resonant movement occurs.

[0022] In summary, the present invention has the following beneficial effects:

[0023] The sensor system collects the vertical swing motion information of the Spar platform in real time, inputs it through the parameter input terminal set on the prediction device, and performs calculation processing through the analog operation circuit combined with the vertical swing motion to obtain the predicted platform vertical swing information in real time. The display screen of the device body can display it in real time for real-time observation, and the warning module can give timely warning after the prediction, which is convenient for the operator to deal with and avoid it in time, reduce the occurrence of safety accidents, and improve the overall stability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the device body;

[0025] Figure 2 It is a schematic block diagram of the structure of the prediction device;

[0026] Figure 3 This is the circuit principle block diagram of the analog operation circuit.

[0027] In the figure: 1. Device body; 11. Display screen; 12. Parameter input terminal; 13. Adjustment knob; 14. Warning module; 2. Sensor system; 3. Analog operation circuit. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0029] In deep-sea oilfield exploitation, the Spar platform stands out among many deep-water operating platforms due to its deep draft, good stability, and high flexibility. The deep-sea environmental conditions in the South my country Sea are harsh, and the Spar platform can be used as the main floating structure for oil and gas development in the South China Sea in the future. The Spar platform is easy to install and reuse, and the center of buoyancy is higher than the center of gravity. Compared with other platforms, the pitch motion is smaller.

[0030] According to one or more embodiments, a Spar platform parameter resonance prediction device based on analog circuit is disclosed, such as Figure 1 and Figure 2 As shown, it includes a device body, a sensor system and an analog computing circuit.

[0031] like Figure 1 As shown, the device body includes several parameter input terminals for inputting the platform inherent parameters and the heave motion information parameters collected by the sensor system, several adjustment knobs for adjusting the platform inherent parameters, a display screen for displaying the processing output results, and a warning module for warning when resonant motion is predicted to occur. The device body is connected to the sensor system through the parameter input terminal, and the analog operation circuit is installed inside the device body. There are four parameter input terminals, which are respectively used to receive the input of the natural frequency of the pitch motion, the heave motion, the heave motion frequency and the platform damping coefficient. There are two adjustment knobs for adjusting the platform inherent parameters, which are divided into the first adjustment knob and the second adjustment knob. The platform inherent parameters include the damping coefficient and the natural frequency of the pitch motion; the heave motion information includes the heave motion and the heave motion frequency. The device body structure has no welding interface and is only made of a whole piece of aluminum alloy through cutting, grinding and other steps.

[0032] The sensor system collects the vertical swing motion information, including displacement sensors, accelerometers and gyroscopes for collecting the vertical swing motion of the Spar platform.

[0033] According to the pitch motion expression under irregular waves, it can be rewritten as the pitch motion under actual sea conditions:

[0034]

[0035] Among them, u5 represents the amplitude of the pitch angle changing with time τ, c5 represents the damping during the pitch motion, represents the pitch restoring force, where ω 50 is the natural frequency of pitch motion, represents the heave motion, ω i is the heave frequency.

[0036] like Figure 3As shown, the analog operation circuit includes a first multiplication unit, a second multiplication unit, a first division unit, a second division unit, a first proportional amplifier, a second proportional amplifier, a third multiplication unit, a fourth multiplication unit, an addition unit, a first first integration unit, a second first integration unit, and a third proportional amplifier. The analog operation circuit refers to establishing a dynamic circuit model of pitch motion through electromechanical analogy, and the corresponding circuit equation corresponds to the pitch motion equation after dimensionless transformation. Therefore, each term in the motion equation corresponds to each term in the circuit equation.

[0037] The first multiplication unit is coupled to the parameter input terminal to receive the input natural frequency of the pitch motion, the second multiplication unit is coupled to the parameter input terminal to receive the input heave motion frequency, the first division unit is coupled to the output ends of the first multiplication unit and the second multiplication unit, the second division unit is coupled to receive the parameter input terminal of the heave motion and the output end of the second multiplication unit, the first proportional amplifier is coupled to the first division unit, and the second proportional amplifier is coupled to the second division unit.

[0038] One input terminal of the third multiplication unit is coupled to the output terminal of the first proportional amplifier, and the other input terminal is coupled to the output terminal of the second first-time integration unit; one input terminal of the fourth multiplication unit is coupled to the output terminal of the second proportional amplifier, and the other input terminal is coupled to the output terminal of the second first-time integration unit.

[0039] The adding unit is coupled to the output end of the third multiplying unit, the fourth multiplying unit and the third proportional amplifier, the first first-time integrating unit is coupled to the output end of the adding unit, the second first-time integrating unit is coupled to the output end of the first first-time integrating unit; the third proportional amplifier is coupled to the output end of the first first-time integrating unit, and the second first-time integrating unit outputs the final simulation operation result. The simulation operation circuit is a circuit model established by writing circuit equations according to the pitch motion equation, and the model contains a closed-loop structure.

[0040] Natural frequency of pitch motion ω 50 Input to the two input ports of the first multiplication unit to realize the square term of the natural frequency of the pitch motion Heave frequencyω i Input into the two input terminals of the second multiplication unit to realize the square term of the heave motion frequency The output end of the first multiplication unit and the output end of the second multiplication unit are respectively connected to the input port of the first division unit to implement the division operation and obtain the parameter In addition, the output of the second multiplication unit is related to the heave motion As the input of the second division unit, the parameter The outputs of the first division unit and the second division unit are respectively used as the inputs of the first proportional amplifier and the second proportional amplifier to achieve parameter amplification, and the obtained and The former corresponds to the parameter a in the pitch motion equation, and the latter corresponds to the parameter One input end of the third multiplication unit is connected to the output end of the first proportional amplifier, and the other input end is connected to the output u5(τ). Similarly, one input end of the fourth multiplication unit is connected to the output end of the second proportional amplifier, and the other input end is connected to the output u5(τ). The outputs of the third multiplication unit, the fourth multiplication unit and the third proportional amplifier are all used as inputs of the addition unit. The addition unit uses an inverse adder, so that its output is Right now The output of the addition unit is connected to two first-order integration units in sequence, namely the first first-order integration unit and the second first-order integration unit, that is, the output result of the addition unit is subjected to a second-order integration operation, and the output end of the second first-order integration unit is used as the input of the multiplication unit, forming a closed-loop structure internally, and the normalized circuit equation is consistent with the pitch motion equation in form. The output unit is the output result u5(τ) of the second first-order integration unit.

[0041] The adjustment knob includes a first adjustment knob and a second adjustment knob, respectively: the adjustment amount of the first adjustment knob corresponds to the amplification factor of the first proportional amplifier, the adjustment amount of the second adjustment knob corresponds to the amplification factor of the second proportional amplifier, and the damping coefficient input by the input terminal corresponds to the amplification factor of the third proportional amplifier. It is used to adjust the inherent parameters of the platform, and the adjustable precision is 0.1.

[0042] The sensor system inputs the measured heave motion and heave motion frequency into the corresponding parameter input terminals respectively, and at the same time, inputs the natural frequency and damping coefficient of the platform's pitch motion into the corresponding parameter input terminals. According to the formula Combined with the platform structural parameters: pitch motion natural period, water plane area, pitch motion moment of inertia, attached water mass, displacement and initial stability, the magnification is obtained through calculation and processing. Adjust the first proportional amplification knob according to the amplification factor; similarly, through the formula Calculate the magnification Adjust the second proportional amplification knob accordingly. After the device is started, the analog operation circuit performs operation processing on the input parameters, displays the output pitch motion waveform on the display screen of the device body, and displays its amplitude and frequency information in digital form.

[0043] The display screen will display the output result of the analog operation circuit and cooperate with the warning module to give an early warning. The warning module includes a warning light and a buzzer set on the device body. When the device is used to predict the pitch movement of the Spar platform, if the platform is unstable, the warning light flashes and sounds.

[0044] The Spar platform parameter resonance prediction device is used to predict the parameter resonance of the platform in service, analyze the heave motion information collected by the external sensor system, and observe the pitch response under the corresponding conditions, make a judgment on the stability of the Spar platform and divide it into corresponding intervals, and use the analog circuit method to predict the motion state of the platform at the next moment according to the pitch waveform at the current moment, and monitor whether it will undergo resonant motion.

[0045] According to one or more embodiments, a method for predicting resonance of a Spar platform parameter based on an analog circuit is disclosed, comprising the following steps:

[0046] The sensor system detects the heave motion and heave motion frequency of the platform and inputs them into the corresponding parameter input terminal of the device body;

[0047] Input the natural frequency and damping coefficient of the pitch motion of the platform into the corresponding parameter input terminal of the device body;

[0048] The amplification factor is obtained by calculation and processing based on the pitch motion expression under irregular waves and the platform structural parameters, and the proportional amplification adjustment is completed by controlling the adjustment knob;

[0049] The device is started to perform real-time calculation processing through an analog calculation circuit, output the prediction result of the next moment to the display screen for display, and issue a warning reminder when resonant movement occurs.

[0050] In the early design stage, the platform can output a stable pitch waveform in actual sea conditions by changing the input parameters of the prediction device to determine its stable range. At the same time, record the input of each parameter of the platform in a stable state, correspond the motion equation to the platform parameters one by one, and rationalize the design of the Spar platform in combination with the change range of the corresponding parameters. The data measured under actual sea conditions are true and valid, providing reference value for the design of the Spar platform. The platform's inherent parameters specifically include: the inherent period of pitch motion, waterplane area, moment of inertia of pitch motion, attached water mass, displacement, initial stability height and damping.

[0051] At the same time, in order to make the Spar platform better adapt to sea conditions, the real-time pitch motion data displayed by the device can be used to change the inherent structure of the Spar platform in order to change its pitch, heave inherent period, initial stability height, waterplane area and other parameters, and design a more stable Spar platform to meet sea conditions.

[0052] When predicting the parameters of the pitch motion of the Spar platform in later service, the collected heave motion information is analyzed, and the pitch response under the corresponding conditions is observed. The stability of the Spar platform is judged and divided into corresponding intervals. The motion state of the platform at the next moment is predicted according to the pitch waveform at the current moment through analog circuits, and it is detected whether it will undergo resonant motion.

[0053] The present invention can be used in the initial design stage and stability prediction stage of the Spar platform. When nonlinear damping is ignored, the pitch / heave coupled motion equation of the platform is a variable coefficient differential equation. As far as the existing technology and processing methods are concerned, it is impossible to find its analytical solution, and its dynamic response can only be described by numerical analysis. Obviously, numerical simulation cannot monitor and accurately measure the platform response in real time. Therefore, based on the continuity and real-time characteristics of analog circuits, a new research method is provided for the early design, parameter pitch prediction and hydrodynamic response of the Spar platform.

[0054] (1) The present invention corresponds the pitch motion equation of the Spar platform to the circuit equation established by the internal analog circuit, obtains real-time monitored heave motion information based on the input, and then displays the pitch motion in real time and determines the platform motion response, providing a new research method for the hydrodynamic response of the Spar platform.

[0055] (2) The present invention monitors the response of the heave / pitch coupling motion by means of an analog circuit. Since the analog signal has the advantage of continuity, the description of the pitch motion is more accurate than the process of solving the approximate analytical solution, and the structure and external conditions of the platform can be further analyzed according to its dynamic response. At the same time, compared with the numerical solution of the pitch motion, it has a real-time effect and can directly simulate the response of the Spar platform at each moment.

[0056] (3) The present invention makes reasonable suggestions for the preliminary design of the Spar platform by changing the input parameters of the device.

[0057] (4) The present invention has the characteristic of real-time monitoring, and can predict the stable state of the Spar platform at the next moment through the existing data information, and prompt the staff to take corresponding security measures through the early warning function to improve the overall safety of the platform.

[0058] (5) The device of the present invention is small in size, simple in structure, easy to operate, moisture-proof and has good sealing performance.

[0059] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A Spar platform parameter resonance prediction device based on analog circuit, characterized in that: It includes a device body, an external sensor system for collecting heaving motion information, and an analog operation circuit arranged inside the device body for analog processing of parameters. The sensor system collects heaving motion information, including a displacement sensor, an accelerometer and a gyroscope for collecting heaving motion of a Spar platform. The analog operation circuit includes a first multiplication unit, a second multiplication unit, a first division unit, a second division unit, a first proportional amplifier, a second proportional amplifier, a third multiplication unit, a fourth multiplication unit, an addition unit, a first primary integration unit, a second primary integration unit, and a third proportional amplifier. The first multiplication unit is coupled to the parameter input terminal to receive the input natural frequency of the pitch motion, the second multiplication unit is coupled to the parameter input terminal to receive the input frequency of the heave motion, the first division unit is coupled to the output ends of the first multiplication unit and the second multiplication unit, the second division unit is coupled to the parameter input terminal for receiving the heave motion and the output end of the second multiplication unit, the first proportional amplifier is coupled to the first division unit, and the second proportional amplifier is coupled to the second division unit; One of the input terminals of the third multiplication unit is coupled to the output terminal of the first proportional amplifier, and the other input terminal is coupled to the output terminal of the second first-integration unit; One of the input terminals of the fourth multiplication unit is coupled to the output terminal of the second proportional amplifier, and the other input terminal is coupled to the output terminal of the second first-integration unit; The adding unit is coupled to the output ends of the third multiplying unit, the fourth multiplying unit and the third proportional amplifier, the first first-time integrating unit is coupled to the output end of the adding unit, and the second first-time integrating unit is coupled to the output end of the first first-time integrating unit; The third proportional amplifier is coupled to the output end of the first first-time integration unit, and the second first-time integration unit outputs the final simulation operation result; The device body is provided with a plurality of parameter input terminals for inputting the platform inherent parameters and the heaving motion information parameters collected by the sensor system, a plurality of adjustment knobs for adjusting the platform inherent parameters, a display screen for displaying the processing output results, and a warning module for issuing a warning when a resonant motion is predicted to occur. The platform inherent parameters include a damping coefficient and a natural frequency of the pitch motion; the heaving motion information includes heaving motion and heaving motion frequency; the parameter input terminal is provided with four terminals for inputting the natural frequency of the pitch motion, the heaving motion, the heaving motion frequency and the platform damping coefficient, respectively.

2. The Spar platform parameter resonance prediction device based on analog circuit according to claim 1, characterized in that: The expression of pitch motion under irregular waves is: Among them, u5 represents the amplitude of the pitch angle changing with time τ, c5 represents the damping during the pitch motion, represents the pitch restoring force, where ω 50 is the natural frequency of pitch motion, represents the heave motion, ω i is the heaving motion frequency.

3. The Spar platform parameter resonance prediction device based on analog circuit according to claim 1, characterized in that: The adjusting knob includes a first adjusting knob and a second adjusting knob, the adjusting amount of the first adjusting knob corresponds to the amplification factor of the first proportional amplifier, the adjusting amount of the second adjusting knob corresponds to the amplification factor of the second proportional amplifier, and the damping coefficient input by the input terminal corresponds to the amplification factor of the third proportional amplifier.

4. A Spar platform parameter resonance prediction method based on analog circuit, characterized in that: The Spar platform parameter resonance prediction device based on the analog circuit according to claim 2 comprises the following steps: The sensor system detects the heave motion and heave motion frequency of the platform and inputs them into the corresponding parameter input terminal of the device body; Input the natural frequency and damping coefficient of the pitch motion of the platform into the corresponding parameter input terminal of the device body; The amplification factor is obtained by calculation and processing based on the pitch motion expression under irregular waves and the platform structural parameters, and the proportional amplification adjustment is completed by controlling the adjustment knob; The device is started to perform real-time calculation processing through an analog calculation circuit, output the prediction result of the next moment to the display screen for display, and issue a warning reminder when resonant movement occurs.

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