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, a method of using the assistant systems and ELS system will be used to
recover the energy that was wasted during the crane operation. Thus, the effect on
the equipments that are involved in inducing back driving phenomenon will be
determine.