EFFECT OF ENERGY RECOVERY ON THE HOISTING CRANE ADAPTING CLOSED LOOP HYDRAULIC HOISTING SYSTEM

The purpose of this project is to research and study the effect of energy recovery from closed loop hydraulic hoisting system. The project is specifically involving various types of hoisting cranes such as tower cranes, crawler cranes and offshore cranes. In some cases, closed loop hydraulic hoisting circuit is said to have pump „back driving‟ during lowering the load. The winch is the spool of the crane and its function is to adjust the tension of the wire rope, on in the case of lowering load, to let out the tension of wire rope so the load will be lowered. But, when the load is of sufficient weight, the hydraulic motor at the winch will behave like a hydraulic pump instead of pushing flow back to the actual hydraulic pump. This phenomenon is what needed to be study and find if there will be some effect to the prime mover (for example diesel motor and electric motor). However, the solution for this problem is said to be introducing a heat loading in the system. Heat loading means is to maintain a power resistance so that there will be a countering effect equivalent to the lowering power generated by the hydraulic motor at the winch. Energy recovery methods are essential so that crane system can recover and reutilize energy, save pump supply energy and improve energy utilization of the crane system. To conduct this project, several experiments will be done using the assistant systems to recover the energy that was wasted during the crane operation.