Research On The System Of Boom Energy Regeneration Based On Hybrid Excavators

Hydraulic excavator is the one of the most widely used engineering machinery, because of its efficiency, durable and strong adaptability, and plays a pivotal role in economic construction.But at the same time, hydraulic excavator is also a kind of high fuel consumption,poor emission and serious environmental pollution engineering machinery. As the number of hydraulic excavator are more and more, its energy conservation and environmental protection issues are becoming increasingly urgent and serious. As hybrid energy saving and energy recycling technology have been successful in automobile industry,people show an keen interest about the technology been applicatied in engineering machinery.The dissertation, tied with the projects of "11th five-year 863 plan" on new hybrid power engineering mechanical key technology and engineering machinery hybrid system energy recovery requirements of comprehensive experimental research and development, has studied the boom potential energy recovery system in hybrid hydraulic excavators.For traditional hydraulic excavator,there are some problems such as energy loss and heating caused by boom frequenly falling.To solve these problems and improve work efficiency,a novel system, which consists a hydraulic,accumulator and variable motor, is proposed based on the hydraulic excavator of CLG922LC.In order to study the energy recovery system better, the author builds the model of the system by Matlab in this paper and compares the system performances between the system with a accumulator and the system without a accumulator,also compares the system performances in different parameters to get a set of optimal matching parameters.The chapters of this dissertation are organized as follows: In Chapter 1, this part analyzes the necessity and urgency of the energy saving technology study of hydraulic excavator, and summarizes the developmen process of energy technology in hudraulic excavator at home and abroad.The research content and methods are puted forward.In Chapter 2, the author establishs the motion model about the working device of hudraulic excavator by means of D-H coordinate method,and obtains the barycenter coordinates relationship of each link. In the end, the dynamics equation and the bearing model of hydraulic cylinder loader of each link is deduced by using Lagrange method.In Chapter 3, this paper compared the advantages and disadvantages of several boom energy saving methods mentioned in the literature. On that basis, a new boom potential energy recovery system is designed. And the mathematical model of energy recovery system is established by using Laplace transform method.In the end, the author calculated the inherent frequency of energy recovery system.In Chapter 4, the mathematical model of energy recovery system is simulated by the software of Simulink In different conditions, including the system with a accumulator and the system without a accumulator, different accumulator inflatable pressure, different boom hydraulic cylinder load and different displacement of the motor.ln addition to this, the author studies the change of the performance after joining the PID control in the system energy recovery system.In Chapter 5, In order to research the performance of energy recovery sysyem better, we establish the experimental stage, And compare the difference between the system of non-accumulator and accumulator.Using three performance of the inlet pressure of the motor, super capacitor voltage and system energy recovery value to analyze the recycling effect of the energy recovery system.In Chapter 6, All the work and conclusions of the paper and the shortage of articles are summarized. The future research direction is proposed.