Research On Design Of DP Thruster System Of Deepwater Semi-submersible Platform

The design of DP thruster system challenges engineers to new requirements including sorts of analysis and design methodology, which are different from that of traditional ship thrusters. Through designing the DP thruster system for a specific deepwater semi-submersible platform (Semi), this thesis searches for a reasonable way of DP thruster system design. Several problems faced in design are pointed out and discussed firstly, such as selection of thruster type, characteristics of hydrodynamic interaction, consideration of redundancy etc. In order to obtain accurate information of DP environmental loads, DP environmental loads on Semi are calculated and some tests are finished to prove the calculation; the wave drift force is mainly discussed, in which the calculation is based on the theory of near field integration and a new suit of measurement system is designed to fit for Semi. Two methods for DP capability analysis, i.e. DP Capability Polar Plot and DP Dynamic Simulation, are introduced, calculation models of them are developed, and calculation and result analysis are carried out in some specific examples. Based on two methods introduced above and some other factors like failure model and economic performance, primary design of DP thruster system is conducted and then a final design scheme is decided. Analysis and evaluation about the final scheme are made further. All these work provides valuable reference for practical engineering application and technical methodology for DP capability analysis and evaluation as well.