| Extruder is the key equipment of aluminum extrusion production line,combining mechanical, electrical, hydraulic and computer technology. It has a high operating power and the equipment performance directly affects the yield of aluminum products. But the requirement of extrusion process is strict. Traditional variable pump volumetric speed control extruder,limited by the hydraulic control system of the machine,causing the low yield, severe energy loss, low efficiency of extrusion and other problems. While the loss of energy was converted into heat energy and affects the life of hydraulic components. With the development of industrial control technology and production processes,the reduction of the hardware costs and the promotion of national policies to energy conservation. A lot of domestic research institutions and companies have done lots of researchs to the hydraulic control system of extruder. Energy saving has been an important topic in the field of hydraulic pressure,in the case of satisfing the requirements of the extrusion process and ensuring the yield, dropping energy consumption of hydraulic system for the extruder is important.The energy consumption of extruder was affected by factors of the equipment status,requirements of process and working conditions. There is a certain interaction between various factors,there are also a lot of association between different factors and energy consumption. Therefore,it is necessary to explore and analyze the relationship between energy consumption and other factors,and to carry out energy analysis and energy saving research.This thesis starts from the view of extrusion equipment and extrusion process. Analysis of energy consumption of the traditional variable pump volumetric speed control extruder was studied in depth. Analyzing the energy transfer, conversion, consumption and loss of the hydraulic system for extrusion process. Pump controlled hydraulic servo system extruder was analyzed and designed. Quantitative research and energy saving system simulation research was based on AMESim simulation model. The main research contents are as follows:1. Analyzing factors of extruder hydraulic system,operation process,working principle,system energy consumption characteristics,hydraulic components, the load and control method etc. According to the energy transfer, conversion and loss form of each components of the hydraulic system, energy flow diagram and the energy equation of system was received,the energy balance equation and the power loss equation of each component was established.2. Analyzing the force balance, flow rate, pressure and power characteristics of the hydraulic components. Establishing the mathematical model about the relevant physical quantities of the hydraulic components. Using HCD library of AMESim simulation software to build the components model, setting parameters and simulation to analyze dynamic characteristics of component model and verify the correctness of the model.3. Simulation model of variable pump volumetric speed control of extrusion process for extruder was built.According to the process flow,extrusion process parameters were set. The nonloaded forward moving,forward extrusion and backward fast moving were achieved. Simulation and verification of each stage compared with the experimental data, analysis of displacement, speed, energy consumption and other characteristics of the system verifies the correctness of system model. Simulating the model of related factors of energy consumption of each element. Quantizing input and output power of the element model, energy consumption and loss. Finally summing up the energy consumption distribution,input and output power, the energy loss distribution of system and other key findings. And the influence of different extrusion speed on the energy consumption was analyzed and some relevant measures of saving and reducing energy consumption was proposed.4. Based on the servo direct drive pump control technology, the hydraulic system of the hydraulic system was reformed. Introducing its principle,composition and energy consumption. The direct drive pump-contrlled servo hydraulic system for extruder and the pressure velocity switching control strategy were designed. The AMESim simulation model of system was built. From the perspective of simulation,dynamic characteristic of the system were researched and the energy consumption of two kinds of hydraulic system was compared. The results show that the energy saving effect of the system was significant, which has reference value for the further study of direct drive pump-contrlled servo hydraulic system for extruder. |
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