Research On Energy Saving Technology Of Hydraulic Truck Crane

Hydraulic truck cranes are often used for hoisting,dismounting and transporting in infrastructure construction.The energy loss of the hoisting system is the largest proportion of energy consumption of all systems.In order to achieve energy saving and emission reduction,a hydraulic-electric hybrid hoisting power system is designed in this paper.Firstly,it is analyzed that the power transmission,hydraulic principle,energy flow direction and loss of the traditional hoisting system of hydraulic truck cranes.It is found that the throttling loss and overflow loss of the original hydraulic system are the main ways of energy loss of the hydraulic system,and the waste potential energy wasted when the load is decreased is also considerable.Therefore,in order to eliminate the throttling and overflow losses,It is proposed to replace the original throttling speed control system with a pump-controlled closed-loop system in this paper;in order to reduce the waste of potential energy,according to the development of hybrid technology and energy storage components,a potential energy recovery and reuse system is designed.A supercapacitor with a large capacity that can be charged and discharge at a large current is selected as an energy storage component.And a DC motor having less energy conversion is used as a working motor.Install the energy recovery system in the counterweight position of the crane and reasonably constrain its quality to maintain the performance of the original car.By establishing a hybrid hoisting system simulation model in AMESim,simulation analysis of each working element and hoisting and going down conditions is carried out to formulate a reasonable control strategy.By analyzing the actual working requirements of the hybrid hoisting system,the system function positioning of “hydraulic-based,motor-assisted” is proposed.Through the analysis of the actual control requirements,the basic control mode of "hydraulic system control speed,motor control torque" is proposed.Simulation analysis of the charge and discharge characteristics of the supercapacitor during the load rising and going down process: As the charging and discharging processes proceeds,the changing of the terminal voltage of the supercapacitor causes the charge and discharge current to gradually decrease,thereby reducing the charge and discharge efficiency.Therefore,a control strategy that supercapacitor is charged and discharge at constant power is proposed to improve the efficiency.Through the analysis of the hydraulic system,the hydraulic system speed control strategy is formulated,and the motor control strategy for a constant torque is established by simulating the motor feedback braking and drag characteristics.Analysis of the hydraulic-electric hybrid hoisting system under typical conditions shows that the system can achieve energy savings of about 60%.This study has guiding significance for the energy-saving design of hydraulic truck cranes.