Ji Yulong

Study on Integrated Hydraulic Propulsion Vessel

A ship propulsion method, integrated hydraulic propulsion (IHP), was put forward and its characteristic was discussed. After that, dynamic mathematic model of IHP vessel was developed. Based on the model, dynamic response character of the system and the influences of four parameters (oil bulk modulus, rotary inertia, seawater density and oil temperature) upon the system were discussed. The simulation results show that IHP method is feasible. Oil bulk modulus and rotary inertia will influence the system dynamic behavior significantly. Seawater density and oil temperature will not only influence the dynamic behavior but also the steady state, so these parameters should be taken into account when an IHP system is to be designed. IHP method offers a new idea for ship design.

Study on Control Strategy of Integrated Hydraulic Propulsion Ship

A control strategy, constant power and variable power combination control (CVCC), was put forward for integrated hydraulic propulsion (IHP) ship against its characteristics. Theoretical analysis was conducted through working condition matching characteristic charts to evaluate the effect of this control strategy. Modeling and simulation of IHP ship was researched, and the theoretical analysis results were proved by the simulation results. These results show that CVCC is suitable for IHP ship, the diesel engine can always works under design working condition independent to the ship working conditions, put out rated power and run at rated rotation speed. This solve the problem that diesel engine on Direct Propulsion ship can not put out rated power when the ship works under off-design working conditions. CVCC is more applicable on those ships with various working conditions, such as: mud drag vessel, tugboat and fire ship.

Working condition matching characteristic analysis of IHP system in several working modes

Aimed to be used in engineering ships, war ships and other special ships, integrated hydraulic propulsion (IHP) system is proposed. This system has a unified power source, can easily switch between several working modes, and can recover the stopping energy produced by propeller etc. The matching parts of the system mainly contain engines, propellers, pumps and motors. This paper focuses on the working condition matching characteristic of the system. Only consider the following two working modes: single engine single propeller and double engines double propellers. The matching characteristic of the system in these two modes is studied through the working condition matching characteristic chart. The results show that IHP system has a good matching characteristic. The operating range is wide, so IHP system is suitable for special ships.