The program of the plate crown optimal prediction applied in the plate mill of Wuhan Iron and Steel(Group) Co. Ltd. is described. Optimal prediction is programmed in ALPHA 4000. The original profile, wear, expansion ...The program of the plate crown optimal prediction applied in the plate mill of Wuhan Iron and Steel(Group) Co. Ltd. is described. Optimal prediction is programmed in ALPHA 4000. The original profile, wear, expansion and deformation of work rolls are introduced into the program. The plate crown is controlled by the original profile of work rolls and the draft whose objective is the optimal plate crown. The run schedule is also optimized through the optimal prediction of the plate crown.展开更多
Hot-box is a device used widely in the world for studying thermodynamic properties of architecture material and types of walls. It can run both static and dynamic experiments, and its demand for controlling is high. B...Hot-box is a device used widely in the world for studying thermodynamic properties of architecture material and types of walls. It can run both static and dynamic experiments, and its demand for controlling is high. Because it adopts traditional PI control presently, and is mainly used for static experiments, its dynamic response is bad. Therefore, this paper applies adaptive fuzzy control, which follows dynamic movement quite well to the hotbox device. At the same time, considering the characteristic that the stable state quality is high within little error of traditional PI control, it combines the adaptive fuzzy control with quantity factor and proportion factor serf-adjusting online and PI control to be a new double mode control using different control models at different conditions. The results of hotbox controlling experiments indicate that this control system is better than PI control or single fuzzy control both at response and precision.展开更多
Precise temperature control to decrease movements in positions due to thermal expansion of work pieces is required in the manufacturing processes to achieve nanometer-order accuracy. We analytically examined the effec...Precise temperature control to decrease movements in positions due to thermal expansion of work pieces is required in the manufacturing processes to achieve nanometer-order accuracy. We analytically examined the effect of a method of minimizing movements in positions on a plate with varying generation of noise-heat. Control by monitoring temperature changes caused larger movements in positions than that without control because maximum change in temperature occurred at non-monitoring positions. The best method of minimizing movements in positions due to thermal expansion of a plate with varying generation of noise-heat was model predictive control by the monitoring movements and distributed temperature changes in the control heater according to the effects of the generation of noise-heat. The maximum movement in positions was 6 nm, which was 1/4 times of that without control.展开更多
The previous paper Ref. [1] showed how to calculate activation energies for ideal gas reactions from the CDF （cumulative distribution function） of the MBD （Maxwell Boltzmann Distribution） and the heat capacity dat...The previous paper Ref. [1] showed how to calculate activation energies for ideal gas reactions from the CDF （cumulative distribution function） of the MBD （Maxwell Boltzmann Distribution） and the heat capacity data of the components. The results presented here show comparisons of activation energies of four ideal gases calculated in that way with those calculated from the ND （Normal Distribution） and its CDF. The evaluation of the CDF for the MBD in Ref. [1] required extensive numerical integrations for each substance. In this paper this method of calculating activation energies is generalised, by showing the CDF is a unique function, independent of temperature and composition, enabling the CDF to be presented graphically or in tabular form. These activation energies are compared to those calculated from the ND and its CDF. The MBD is related to the ND because it has a generating function which is shown here to have the simple form （1-kT）-1.5. The activation energies obtained from the CDF of the ND are shown to agree ca. 5-7% with those obtained directly from the MBD. Because existing thermodynamic treatments are based on average properties, they cannot give either a complete account of thermodynamic controlled and kinetic controlled equilibrium states or explain transitions between them. Complete treatments must include effects from the MBD which are the causes of kinetic controlled equilibrium. The basis for a complete treatment is outlined, which includes the standard deviations and activation energies.展开更多
As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temp...As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temperature control loop heat pipe(TCLHP) is designed,which highly meets the thermal control requirements of CCD components.In order to study the dynamic behaviors of heat and mass transfer of TCLHP,particularly in the orbital flight case,a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling.The temperature control principle and details of mathematical model are presented.The model is used to study operating state,flow and heat characteristics based upon the analyses of variations of temperature,pressure and quality under different operating modes and external heat flux variations.The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well,and always ensure good temperature stability and uniformity.By comparison between flight data and simulated results,it is found that the model is to be accurate to within 1℃.The model can be better used for predicting and understanding the transient performance of TCLHP.展开更多
In many heat recovery processes,temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment.In addition,the management of recovered heat is important for the ...In many heat recovery processes,temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment.In addition,the management of recovered heat is important for the proper use of waste heat.To this aim,the concept of thermal management controller(TMC),which can vary heat transfer rate via the volume variation of non-condensable gas,was presented.Theoretical model and experimental prototype were established.Investigation shows that the prototype is effective in temperature control With water as the working fluid,the vapor temperature variation is only 1.3℃when the heating power varies from 2.5 to 10.0 kW.In variable working conditions,this TMC can automatically adjust thermal allocation to the heat consumer.展开更多
文摘The program of the plate crown optimal prediction applied in the plate mill of Wuhan Iron and Steel(Group) Co. Ltd. is described. Optimal prediction is programmed in ALPHA 4000. The original profile, wear, expansion and deformation of work rolls are introduced into the program. The plate crown is controlled by the original profile of work rolls and the draft whose objective is the optimal plate crown. The run schedule is also optimized through the optimal prediction of the plate crown.
文摘Hot-box is a device used widely in the world for studying thermodynamic properties of architecture material and types of walls. It can run both static and dynamic experiments, and its demand for controlling is high. Because it adopts traditional PI control presently, and is mainly used for static experiments, its dynamic response is bad. Therefore, this paper applies adaptive fuzzy control, which follows dynamic movement quite well to the hotbox device. At the same time, considering the characteristic that the stable state quality is high within little error of traditional PI control, it combines the adaptive fuzzy control with quantity factor and proportion factor serf-adjusting online and PI control to be a new double mode control using different control models at different conditions. The results of hotbox controlling experiments indicate that this control system is better than PI control or single fuzzy control both at response and precision.
文摘Precise temperature control to decrease movements in positions due to thermal expansion of work pieces is required in the manufacturing processes to achieve nanometer-order accuracy. We analytically examined the effect of a method of minimizing movements in positions on a plate with varying generation of noise-heat. Control by monitoring temperature changes caused larger movements in positions than that without control because maximum change in temperature occurred at non-monitoring positions. The best method of minimizing movements in positions due to thermal expansion of a plate with varying generation of noise-heat was model predictive control by the monitoring movements and distributed temperature changes in the control heater according to the effects of the generation of noise-heat. The maximum movement in positions was 6 nm, which was 1/4 times of that without control.
文摘The previous paper Ref. [1] showed how to calculate activation energies for ideal gas reactions from the CDF （cumulative distribution function） of the MBD （Maxwell Boltzmann Distribution） and the heat capacity data of the components. The results presented here show comparisons of activation energies of four ideal gases calculated in that way with those calculated from the ND （Normal Distribution） and its CDF. The evaluation of the CDF for the MBD in Ref. [1] required extensive numerical integrations for each substance. In this paper this method of calculating activation energies is generalised, by showing the CDF is a unique function, independent of temperature and composition, enabling the CDF to be presented graphically or in tabular form. These activation energies are compared to those calculated from the ND and its CDF. The MBD is related to the ND because it has a generating function which is shown here to have the simple form （1-kT）-1.5. The activation energies obtained from the CDF of the ND are shown to agree ca. 5-7% with those obtained directly from the MBD. Because existing thermodynamic treatments are based on average properties, they cannot give either a complete account of thermodynamic controlled and kinetic controlled equilibrium states or explain transitions between them. Complete treatments must include effects from the MBD which are the causes of kinetic controlled equilibrium. The basis for a complete treatment is outlined, which includes the standard deviations and activation energies.
文摘As one of the key units of space CCD camera,the temperature range and stability of CCD components affect the image's indexes.Reasonable thermal design and robust thermal control devices are needed.One kind of temperature control loop heat pipe(TCLHP) is designed,which highly meets the thermal control requirements of CCD components.In order to study the dynamic behaviors of heat and mass transfer of TCLHP,particularly in the orbital flight case,a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling.The temperature control principle and details of mathematical model are presented.The model is used to study operating state,flow and heat characteristics based upon the analyses of variations of temperature,pressure and quality under different operating modes and external heat flux variations.The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well,and always ensure good temperature stability and uniformity.By comparison between flight data and simulated results,it is found that the model is to be accurate to within 1℃.The model can be better used for predicting and understanding the transient performance of TCLHP.
基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20040248055)the Education Ministry Key Investigation Project of Science and Technology(No.306004)
文摘In many heat recovery processes,temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment.In addition,the management of recovered heat is important for the proper use of waste heat.To this aim,the concept of thermal management controller(TMC),which can vary heat transfer rate via the volume variation of non-condensable gas,was presented.Theoretical model and experimental prototype were established.Investigation shows that the prototype is effective in temperature control With water as the working fluid,the vapor temperature variation is only 1.3℃when the heating power varies from 2.5 to 10.0 kW.In variable working conditions,this TMC can automatically adjust thermal allocation to the heat consumer.
