针对变电站建设工期因受各种因素影响而产生的不确定性问题,分析了传统计划评审技术(program evaluation and reviewtechnique,PERT)模型的优缺点,提出了基于模糊网络计划模型,即将模糊隶属度函数引入到网络进度计划中,建立模糊关键线...针对变电站建设工期因受各种因素影响而产生的不确定性问题,分析了传统计划评审技术(program evaluation and reviewtechnique,PERT)模型的优缺点,提出了基于模糊网络计划模型,即将模糊隶属度函数引入到网络进度计划中,建立模糊关键线路模型及其时间参数计算方法,实际应用证明,该模型具有较高的应用价值。展开更多
An experimental model of maldistribution was established and grey correlation analysis method was employed to describe quantitatively the maldistribution phenomenon in the feeding device of copper flash smelting.Parti...An experimental model of maldistribution was established and grey correlation analysis method was employed to describe quantitatively the maldistribution phenomenon in the feeding device of copper flash smelting.Particle motion in the feeding device was separated into uniform flow in chute and restricted slanting parabolic motion in distributor channel.Factors affecting particle velocity at the chute outlet and particle moving distance in the distributor channel,which also cause the maldistribution,were analyzed based on the assumption of pseudo fluid.Experiments were conducted to study the maldistribution using river sand.The results indicate obvious mass maldistribution and an even higher degree with the increase of feeding mass rate;meanwhile,size maldistribution is negligible.Also,feeding intensity has a larger impact on circumferential maldistribution than on radial maldistribution.Based on the experimental results of the eight factors impacting the maldistribution,grey relation of each factor was calculated using grey correlation analysis.The importances of these factors were sequenced.The results show that a proper adjustment of the structure will ameliorate the maldistribution phenomenon in the feeding device of copper flash smelting.展开更多
A heat transfer model of furnace roller cooling process was established based on analysis of furnace roller＇s structure. The complicated model was solved with iteration planning algorithm based on Newton search. The ...A heat transfer model of furnace roller cooling process was established based on analysis of furnace roller＇s structure. The complicated model was solved with iteration planning algorithm based on Newton search. The model is proved logical and credible by comparing calculated results and measured data. Then, the relationship between water flow velocity, inlet water temperature, furnace temperature and roller cross section temperature, outlet water temperature, water temperature rise, cooling water heat absorption was studied. The conclusions and recommendations are mainly as follows： l） Cooling water temperature rise decreases with the increase of water flow velocity, but it has small relationship with inlet water temperature; 2） In order to get little water scale, inlet water temperature should be controlled below 30 ℃. 3） The cooling water flow velocity should be greater than critical velocity. The critical velocity is 0.07 m/s and water flow velocity should be controlled within 0.4-0.8 m/s. Within this velocity range, water cooling efficiency is high and water temperature rise is little. If cooling water velocity increases again, heat loss will increase, leading to energy wasting.展开更多
文摘针对变电站建设工期因受各种因素影响而产生的不确定性问题,分析了传统计划评审技术(program evaluation and reviewtechnique,PERT)模型的优缺点,提出了基于模糊网络计划模型,即将模糊隶属度函数引入到网络进度计划中,建立模糊关键线路模型及其时间参数计算方法,实际应用证明,该模型具有较高的应用价值。
基金Project(2010AA065201) supported by the National High Technology Research and Development Program of China
文摘An experimental model of maldistribution was established and grey correlation analysis method was employed to describe quantitatively the maldistribution phenomenon in the feeding device of copper flash smelting.Particle motion in the feeding device was separated into uniform flow in chute and restricted slanting parabolic motion in distributor channel.Factors affecting particle velocity at the chute outlet and particle moving distance in the distributor channel,which also cause the maldistribution,were analyzed based on the assumption of pseudo fluid.Experiments were conducted to study the maldistribution using river sand.The results indicate obvious mass maldistribution and an even higher degree with the increase of feeding mass rate;meanwhile,size maldistribution is negligible.Also,feeding intensity has a larger impact on circumferential maldistribution than on radial maldistribution.Based on the experimental results of the eight factors impacting the maldistribution,grey relation of each factor was calculated using grey correlation analysis.The importances of these factors were sequenced.The results show that a proper adjustment of the structure will ameliorate the maldistribution phenomenon in the feeding device of copper flash smelting.
基金Project(2010CB630800) supported by the National Basic Research Program of China
文摘A heat transfer model of furnace roller cooling process was established based on analysis of furnace roller＇s structure. The complicated model was solved with iteration planning algorithm based on Newton search. The model is proved logical and credible by comparing calculated results and measured data. Then, the relationship between water flow velocity, inlet water temperature, furnace temperature and roller cross section temperature, outlet water temperature, water temperature rise, cooling water heat absorption was studied. The conclusions and recommendations are mainly as follows： l） Cooling water temperature rise decreases with the increase of water flow velocity, but it has small relationship with inlet water temperature; 2） In order to get little water scale, inlet water temperature should be controlled below 30 ℃. 3） The cooling water flow velocity should be greater than critical velocity. The critical velocity is 0.07 m/s and water flow velocity should be controlled within 0.4-0.8 m/s. Within this velocity range, water cooling efficiency is high and water temperature rise is little. If cooling water velocity increases again, heat loss will increase, leading to energy wasting.
