This paper discusses a design method for the control system of a weigh feeder that supplies powder and granular material at a constant rate. Most weigh feeders employed in industry are controlled by proportional and i...This paper discusses a design method for the control system of a weigh feeder that supplies powder and granular material at a constant rate. Most weigh feeders employed in industry are controlled by proportional and integral （PI） compensation, and the control performance is decided by the selection of parameters. To attain advanced control performance by PI control, the PI parameters are designed on the basis of generalized minimum variance control （GMVC）. In this study, to achieve user-specified control performance by GMVC-based PI control, the design parameters of GMVC are automatically adjusted using a performance-adaptive method. The control performance discussed in this study consists of the variance of the control error and that of the difference in the control input. In a conventional performance-adaptive method, the variance of the control error is reduced. In this study, to reduce energy consumption and to achieve user-specified control performance, the variance of the difference in the control input is specified and the design parameter is determined. To demonstrate its effectiveness, the proposed method is applied to an actual weigh feeder.展开更多
Korea imports about 97% of its energy resources as its available energy resources are extremely limited. Thus, the role of nuclear power in electricity generation is expected to become more important in future years. ...Korea imports about 97% of its energy resources as its available energy resources are extremely limited. Thus, the role of nuclear power in electricity generation is expected to become more important in future years. A fast reactor system is one of the most promising options for electricity generation with an efficient utilization of uranium resources and a reduction of radioactive wastes. Based on the experiences gained during the development of the conceptual designs for KALIMER （Korea advanced liquid metal reactor）, the KAERI （Korea Atomic Energy Research Institute） is currently developing advanced SFR （sodium cooled fast reactor） design concepts that can better meet the Gen IV （Generation IV） technology goals. The long-term advanced SFR development plan will be carried out toward the construction of an advanced SFR demonstration plant by 2028. Advanced concept design studies and the development of the advanced SFR technologies necessary for its commercialization and basic key technologies carried out by KAERI are included in this paper.展开更多
Preliminary design and simulation of a free piston engine suitable for small-scale energy production in distributed energy systems is presented in this paper.The properties,particularly the properties of gas seals of ...Preliminary design and simulation of a free piston engine suitable for small-scale energy production in distributed energy systems is presented in this paper.The properties,particularly the properties of gas seals of the engine are simulated using a simulation program developed for this case,and the results are utilized in preliminary main design parameter selection.The engine simulation program was developed by combining and modifying the source codes of the simulation and calculation programs obtained from Helsinki University of Technology,Tampere University of Technology,and Lappeenranta University of Technology.Because of the contact-free labyrinth seal used in the piston,the efficiency of the motor is lower than the efficiency of a conventional motor with oil lubricated piston rings.On the other hand,the lack of bearing losses,and the lack of losses associated with a crankshaft system and a gearbox,as well as the lack of lubrication oil expenses,compensates this effect.As a net result,this new motor would perform slightly better than the conventional one.Being completely oil-free,it is very environmentally friendly,and its exhaust gases are completely free of oil residuals which are causing problems in normal gas motors.展开更多
文摘This paper discusses a design method for the control system of a weigh feeder that supplies powder and granular material at a constant rate. Most weigh feeders employed in industry are controlled by proportional and integral （PI） compensation, and the control performance is decided by the selection of parameters. To attain advanced control performance by PI control, the PI parameters are designed on the basis of generalized minimum variance control （GMVC）. In this study, to achieve user-specified control performance by GMVC-based PI control, the design parameters of GMVC are automatically adjusted using a performance-adaptive method. The control performance discussed in this study consists of the variance of the control error and that of the difference in the control input. In a conventional performance-adaptive method, the variance of the control error is reduced. In this study, to reduce energy consumption and to achieve user-specified control performance, the variance of the difference in the control input is specified and the design parameter is determined. To demonstrate its effectiveness, the proposed method is applied to an actual weigh feeder.
文摘Korea imports about 97% of its energy resources as its available energy resources are extremely limited. Thus, the role of nuclear power in electricity generation is expected to become more important in future years. A fast reactor system is one of the most promising options for electricity generation with an efficient utilization of uranium resources and a reduction of radioactive wastes. Based on the experiences gained during the development of the conceptual designs for KALIMER （Korea advanced liquid metal reactor）, the KAERI （Korea Atomic Energy Research Institute） is currently developing advanced SFR （sodium cooled fast reactor） design concepts that can better meet the Gen IV （Generation IV） technology goals. The long-term advanced SFR development plan will be carried out toward the construction of an advanced SFR demonstration plant by 2028. Advanced concept design studies and the development of the advanced SFR technologies necessary for its commercialization and basic key technologies carried out by KAERI are included in this paper.
基金Project is financed by the Technology Development Center of Finland (Tekes)
文摘Preliminary design and simulation of a free piston engine suitable for small-scale energy production in distributed energy systems is presented in this paper.The properties,particularly the properties of gas seals of the engine are simulated using a simulation program developed for this case,and the results are utilized in preliminary main design parameter selection.The engine simulation program was developed by combining and modifying the source codes of the simulation and calculation programs obtained from Helsinki University of Technology,Tampere University of Technology,and Lappeenranta University of Technology.Because of the contact-free labyrinth seal used in the piston,the efficiency of the motor is lower than the efficiency of a conventional motor with oil lubricated piston rings.On the other hand,the lack of bearing losses,and the lack of losses associated with a crankshaft system and a gearbox,as well as the lack of lubrication oil expenses,compensates this effect.As a net result,this new motor would perform slightly better than the conventional one.Being completely oil-free,it is very environmentally friendly,and its exhaust gases are completely free of oil residuals which are causing problems in normal gas motors.
