CN-122021033-A - Modelica-based multi-domain coupling modeling method for FPSO complex equipment

CN122021033ACN 122021033 ACN122021033 ACN 122021033ACN-122021033-A

Abstract

The invention relates to the field of digital design of marine equipment, in particular to a model-based FPSO complex equipment multi-field coupling modeling method, which comprises the steps of carrying out top-down hierarchical decomposition on a vertical support system and designing a unified model library architecture and interface specification; the method comprises the steps of developing a modularized model component library of a control system, a hydraulic system and a mechanical system based on Modelica, designing three types of coupling interfaces of mechanical-hydraulic energy, control-hydraulic signals and control-mechanical feedback, integrating a multi-field equation into a unified differential algebra system by utilizing the non-causal modeling characteristic of Modelica, processing multiple time scales and discrete events, integrating model components in each field to construct a system digital prototype, and performing full-coupling simulation verification of typical working conditions. The invention realizes unified description and seamless coupling of the multi-field models of the FPSO complex equipment, improves the design cooperativity and model reusability, and greatly reduces the design verification cost.

Inventors

FU QIANG
You Hexin
WANG BO
ZHANG HAODONG
WANG BOWEN
QU BO
GUO LIJUAN
Kong Yonghan
ZHANG KEXIN
LI HUIJUAN

Assignees

中集海洋工程研究院有限公司
深圳智能海洋工程创新中心有限公司

Dates

Publication Date: 20260512
Application Date: 20260203

Claims (10)

1. A Modelica-based FPSO complex equipment multi-domain coupling modeling method is characterized by comprising the following steps: s1, decomposing a vertical pipe supporting system into control, hydraulic and mechanical subsystems and defining standardized interface specifications of each model component; S2, developing multi-field components, namely respectively developing corresponding control system model components, hydraulic system model components and mechanical system model components by using Modelica language based on the standardized interface specification; s3, the coupling mechanism is realized by designing mechanical-hydraulic, control-hydraulic and control-mechanical coupling interfaces based on the model component, integrating component equations into a unified differential algebraic equation set system, and processing the problem of multiple time scales; s4, integrating the model components through a coupling interface, constructing a system digital prototype, and performing full-coupling simulation to verify system performance.
2. The modeling method for multi-domain coupling of FPSO complex equipment based on Modelica according to claim 1, wherein the decomposing the riser support system into control, hydraulic and mechanical subsystems and defining standardized interface specifications of each model component specifically comprises: Aiming at the FPSO vertical pipe supporting system, a top-down method is adopted to conduct layering decomposition, the whole system is decomposed into three main subsystems of a control system, a hydraulic system and a mechanical system, and each subsystem is further decomposed into functional modules; Based on MWORKS platform, unified hierarchical model library architecture is designed, and standardized interfaces and parameter specifications of each model component are defined.
3. The modeling method for multi-domain coupling of FPSO complex equipment based on Modelica according to claim 2, wherein the unified hierarchical model library architecture is characterized in that the top layer is a riser supporting system assembly model, the middle layer is a control system, a hydraulic system and a mechanical system, the bottom layer is a basic model component corresponding to each functional module, and all components conform to the unified physical port and signal port interface specification.
4. The model-based FPSO complex equipment multi-domain coupling modeling method according to claim 1, wherein the control system model component at least comprises a hydraulic controller model and a PID controller model; the hydraulic controller model is realized by adopting a tracking differentiator algorithm, the discrete form of the hydraulic controller model is used for rapidly tracking an input signal and extracting a differentiated signal, and the tracking speed is controlled by setting a speed factor so as to inhibit the noise amplification effect.
5. The model-based FPSO complex equipment multi-domain coupling modeling method according to claim 4, wherein the hydraulic system model components at least comprise TSUDL system model components for top support and lateral pushing, and BSDL system model components for bottom support; The TSUDL system model component comprises a tip cone loop and a transverse pushing loop, wherein the tip cone loop model is described by a pressure reducing valve pressure regulation equation, a control valve flow equation, a hydraulic cylinder force balance equation and a flow continuity equation and is used for simulating the driving and controlling of a rotating ring; The BSDL system model component is described by an equation set comprising a valve port flow equation, an oil cylinder force balance equation and a flow continuity equation and is used for simulating the dynamic action process of the bottom support oil cylinder.
6. The model-based multi-domain coupling modeling method of FPSO complex equipment according to claim 5, wherein the mechanical system model component at least comprises a frame model, a rotating ring model, a wedge model, a locking mechanism model, a transverse pushing piston model and an actuating mechanism model; the mechanical system model assembly is built based on a multi-body dynamics theory, wherein a rotating ring model is built based on a dynamics equation of rigid body rotation around a fixed shaft, a wedge model is built based on a dynamics equation of constraint rigid body linear motion, a locking mechanism model is built based on a Newton-Euler equation comprising a nonlinear contact force model, and a transverse pushing piston model and an actuating mechanism model are built based on a piston dynamics equation.
7. The FPSO complex equipment multi-domain coupling modeling method based on Modelica according to claim 1, wherein mechanical-hydraulic, control-hydraulic and control-mechanical coupling interfaces are designed based on the model components, component equations are integrated into a unified differential algebraic equation set system, and a multi-time scale problem is processed, and the method specifically comprises the following steps: the cross-domain coupling interface is designed and realized based on the model component developed in the step S2, and comprises the steps of establishing an energy coupling interface of a mechanical system and a hydraulic system through the mapping relation between the piston displacement of the hydraulic cylinder and the hydraulic pressure and flow, establishing a signal coupling interface of the control system and the hydraulic system through the relation between a control signal and the opening degree of a hydraulic valve, and establishing a feedback coupling interface of the control system and the mechanical system through a sensor feedback signal; By utilizing the non-causal modeling characteristic of Modelica, the physical equations in all fields are integrated into a unified differential algebraic equation system, and a symbol processing, BLT transformation and self-adaptive variable step length solving strategy is adopted to process a multi-time scale problem and discrete events.
8. The modeling method for multi-domain coupling of FPSO complex equipment based on Modelica according to claim 7, wherein the integration of the physical equations of each domain into a unified system of differential algebraic equations comprises the following steps: The force balance equation, the kinematics equation, the hydrodynamic equation, the flow continuity equation and the control algorithm equation of the control system of the mechanical system are uniformly expressed as Modelica equations in a non-causal form, and a compiler automatically generates a differential algebraic equation set of the whole system.
9. The modeling method for multi-domain coupling of FPSO complex equipment based on Modelica according to claim 7, wherein the adaptive variable step size solving strategy specifically comprises the following steps: according to different dynamic response time scales of the control system, the hydraulic system and the mechanical system, the integral step length is dynamically adjusted in the simulation solving process, and an event detection mechanism is introduced for discrete events of hydraulic valve switching and mechanical contact collision.
10. The FPSO complex equipment multi-domain coupling modeling method based on Modelica according to claim 1, wherein the model components are integrated through a coupling interface to construct a system digital prototype, and full-coupling simulation is performed to verify system performance, and specifically comprises the following steps: Carrying out full system integration on the model component developed in the step S2 through the coupling interface realized in the step S3, and connecting a control system model, a hydraulic system model and a mechanical system model with an information flow interface through standardized energy flows to form a closed-loop simulation system comprising complete physical effects and logic control, so as to construct a digital prototype of the FPSO vertical pipe supporting system; and in a unified simulation environment, performing full-coupling dynamic simulation on typical locking and releasing conditions of the three pipes, acquiring and analyzing the action sequence, displacement, speed, pressure and flow performance indexes of the system, and completing the function and performance verification of the system design scheme.

Description

Modelica-based multi-domain coupling modeling method for FPSO complex equipment Technical Field The invention relates to the technical field of digital design of marine equipment, in particular to a Modelica-based multi-field coupling modeling method for FPSO complex equipment. Background The FPSO (floating production, storage and offloading unit, floating Production Storage and Offloading) is an offshore floating unit integrating oil and gas production, storage and offloading functions, and is widely used for oil and gas field development in all sea areas worldwide as core equipment for deep-sea oil and gas development. FPSOs are typically composed of a hull, an upper module, a mooring system and a riser system, etc., wherein the riser system is responsible for connecting the subsea wellhead with the FPSO deck facilities for oil and gas transportation. As a major equipment in the field of ocean engineering, the safety and reliability of FPSOs are directly related to continuity of offshore oil and gas production and personnel and equipment safety. Among the many critical systems of FPSOs, riser locking systems, for example, are typically multi-domain complex systems that take on the critical functions of supporting riser weight, absorbing wave loads, keeping risers stable, etc. The system is highly integrated by a plurality of subsystems such as a mechanical structure, hydraulic drive, electric control and the like, and relates to a plurality of disciplines such as mechanical dynamics, hydrodynamics, control theory and the like, and complex energy flow, information flow and material flow interaction exist among the subsystems. For example, deformation of the mechanical structure may affect the pressure distribution of the hydraulic system, while commands from the control system may change the operating state of the hydraulic system, thereby affecting the force and displacement of the entire mechanical structure. This multi-physical field coupling and multi-time scale nature makes design verification of riser support systems a significant challenge. The traditional locking system design mainly depends on a simplified model or physical prototype test in a single field, and has the following problems: the field splitting is that modeling is carried out by adopting independent tools and methods in different professional fields such as machinery, hydraulic pressure, control and the like, so that system-level coupling analysis is difficult to realize, and design defects are difficult to discover early; The model reusability is poor, the existing modeling method lacks a unified architecture design, model components are difficult to reuse among different projects, and a large number of repeated works are needed for each new design; The verification cost is high, the test is excessively dependent on a physical prototype, the cycle is long, the cost is high, various extreme working conditions are difficult to cover, and potential safety hazards exist; The multi-physical field coupling effect is difficult to accurately describe, the riser locking system relates to multi-field coupling such as mechanical dynamics, hydrodynamics, control theory and the like, and the traditional method is difficult to accurately capture the interaction relation among the fields; The design iteration efficiency is low, the digital model support is lacked, the design modification and verification process is complex, and the quick response to the design requirement change is difficult. These problems severely limit the design quality and development efficiency of the complex equipment of the FPSO. The method is based on the fact that the traditional method fundamentally lacks a unified multi-domain physical modeling language and system architecture support supporting non-causal modeling, so that multi-domain collaboration, model multiplexing and efficient verification in the true sense are difficult to realize. Therefore, there is a need for a digital modeling method that can realize multi-domain collaboration, support model reuse, and reduce verification cost based on such unified architecture to systematically solve the above engineering challenges. Disclosure of Invention The invention aims to solve the problems of multi-field fracturing, poor model reusability, high verification cost, difficult accurate description of multi-physical field coupling effect and the like in the prior art, and provides a Modelica-based FPSO complex equipment multi-field coupling modeling method. The method utilizes the non-causal, object-oriented and multi-domain unified modeling characteristics of Modelica language, combines the strong simulation integration capability of MWORKS platforms to construct a reusable and extensible multi-domain unified model library of ocean engineering complex equipment, realizes the digital design, integration and verification from a component level to a system level, and finally realizes the digital design and verification of