Research On An Energy-Saving Active Heave Compensation System Applied To Deep Water Lifting Operation

Heave compensation system can reduce the impact of waves on the motion of a ship. Because of the flourishing of marine engineering field in recent years, the applications of heave compensation system are becoming increasingly widespread. Active heave compensation is the most advanced compensation technology. Its high compensation precision and little time lag make it necessary to ensure that the offshore operations such as lifting can be carried out safely. However an active heave compensation system consumes a lot of energy and is not conducive to saving energy and protecting the environment, and domestic scholars mostly focused on the control algorithm and the hydraulic actuator design while researching active heave compensation systems. So the research on energy-saving active heave compensation and its control method has a very important practical significance.Firstly, researched heave compensation and hydraulic energy saving technology deeply, designed an energy-saving winch active heave compensation system which can recover the potential energy of the weight on the basis of the characteristics of heave compensation system, then made a calculation of the parameters of each unit. Secondly, established the model of the compensation system with AMESim software, then made simulation of a typical case to research the compensation performance and energy recovery efficiency while compensating. Finally put forward the control method to improve the compensation performance.The main research contents and achievements of this paper are as follows:(1) Analyzed the impact of waves on the motion of a ship, principle and characteristics of the heave compensation system, then made a simulation to verify that the potential energy of the load can be recovered in the active heave compensation system without energy-saving equipment;(2) Designed an energy-saving active heave compensation system. Analyzed the application of various energy storage element with the system and calculated the recyclable energy of the system and parameters of the element, then selected the suitable ones to consist the system;(3) Established the models of secondary unit, variable displacement pump, motor used in the system with AMESim software HCD library and verify its correctness;(4) Established the whole model of energy-saving active heave compensation system, made simulation of 50t, analyzed compensation performance and energy recovery efficiency, and discuss the impact of the accumulator and the motor on the performance of the system;(5) Analyzed the merit of fuzzy PID, then made it the control method of the system, and using SIMULINK software to build their model, co-simulation with AMESim, and analyzed the results.