| With the rapid development of industrial technology around the world, greenhouse effect and energy crisis become growing global threats. Low-carbon manufacturing that aims for low energy consumption and low pollution have been an inevitable demand of manufacturing industry development. Meanwhile, how to improve the energy efficiency of hydraulic press industry, which is characteristic for large scale?wide range, and high energy consumption, plays an important role in Low-carbon Manufacturing. In order to reveal why energy dissipation is occurring, how to qualify energy dissipation distribution, how to control energy dissipation process, the related research work supported by the Key Project of National Natural Science Foundation is carried out in this dissertation The research contents and achievements of this article are mainly represented in the following aspects:On the basis of analyzing the non-equivalence existed in energy conversation process and the limitation of traditional concept of "exergy", the concept of "special exergy" is proposed. It can reveal the essence of energy loss in the area of heat engine. Accoding to the analysis method of classical heat engine system's theoretical efficiency in thermodynamics, generalized computing equation of general energy system's max efficiency is built.Simultaneously, analysis methods of energy system and promotion strategy of energy efficiency which are based on thermodynamics theory are proposed.Based on the energy system analytical method of thermodynamic theory, the energy elements of hydraulic press system are selected, the method of energy elements classification are presented according to the characteristics of energy transform. The energy dissipation characteristics of hydraulic press system in units are investigated, particularly for three-phase asynchronous motor and piston pump. The validity of the models has been verified by comparisons between experimental data supplied by factories and theoretical results calculated by the developed models. It makes up the blank in technical manual. Energy flow model for the service process of hydraulic press is established and analytical procedure for energy flow of hydraulic press is proposed based on the analytical foundation above. This method is not only used to evaluate the present situation of energy system, but also used to assess the energy-saving potential of hydraulic press system.Load characteristics of forming and driving characteristics of hydraulic press system have been studied in this paper. Global and local energy matching control methods are presented according to promotion strategies of energy efficiency which are based on thermodynamic theory. They are respectively used for solving the problems that load is not matching with rating power of hydraulic system (installed power which is well beyond the required loading power, high proportion of standby time), and the problems that the loading is not matching with rating power of motors and pumps units (surplus flow and press, as well as running in the regional of Low efficiency), which are caused by time series load applying on hydraulic press.A case for rapid sheet metal forming with RZU2000 hydraulic press is presented. The energy dissipation distribution for its main drive system during service time is obtained based on qualification method for energy dissipation characteristics of hydraulic pres. The energy consumption of this hydraulic press is evaluated. Physical format model and working time coordination mechanism of six hydraulic presses are investigated to discuss the energy-saving potential of energy matching control for time loading in hydraulic press system, which provide a new idea for the design of hydraulic pressure system and optimization of energy efficiency in the future. |
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