Reducing raw materials consumption(RMC)in electric arc furnace(EAF)steelmaking process is beneficial to the reduction in resource and energy consumption.The conventional indicator of evaluating RMC only focuses on EAF...Reducing raw materials consumption(RMC)in electric arc furnace(EAF)steelmaking process is beneficial to the reduction in resource and energy consumption.The conventional indicator of evaluating RMC only focuses on EAF inputs and outputs,neglecting the associations between smelting operations and RMC.Traditional methods of reducing RMC rely on manual experience and lack a standard operation guidance.A method based on association rules mining and metallurgical mechanism(ARM-MM)was proposed.ARM-MM proposed an improved evaluation indicator of RMC and the indicator independently showed the associations between smelting operations and RMC.On the basis,1265 heats of real EAF data were used to obtain the operation guidance for RMC reduction.According to the ratio of hot metal(HM)in charge metals,data were divided into all dataset,low HM ratio dataset,medium HM ratio dataset,and high HM ratio dataset.ARM algorithm was used in each dataset to obtain specific operation guidance.The real average RMC under all dataset,medium HM ratio dataset,and high HM ratio dataset was reduced by 279,486,and 252 kg/heat,respectively,when obtained operation guidance was applied.展开更多
1. RE Permanent Materials Chinese demand for RE permanent magnets increases at 20% per year. The output of sintered NdFeB magnets will reach 70,000 tons in 2010, 75% of the world total, with sales value of RMB $26 bil...1. RE Permanent Materials Chinese demand for RE permanent magnets increases at 20% per year. The output of sintered NdFeB magnets will reach 70,000 tons in 2010, 75% of the world total, with sales value of RMB $26 billion. 2. RE Catalyst展开更多
Base on the framework of material flow analsis （MFA） proposed by Eurostat, this paper collected related data and conducted a regional MFA for the Chengyang Districgt in Qingdao. The indicators such as Direct Materia...Base on the framework of material flow analsis （MFA） proposed by Eurostat, this paper collected related data and conducted a regional MFA for the Chengyang Districgt in Qingdao. The indicators such as Direct Material Input（DMI）, Direct Material Consumption （DMC） and Exports are calculated or estimated for the period of year 1995 through 2004. Several derivable iudicators defining direct material productivity and material intenstiy are also evaluated and some valuable conclusions were drawn. DMI in absolute number increased from about 1645.9 kilotons in 1995to about 8052.5 kilotons in 2004. Imports contribute to about 47 to 69% of DMI, and the biggest component of imports is fossil fuel that approximatley accounts far 50% of imnports. DMI per capita of Chengyang District increased rapidly and reached 17. 4 tons in 2004. Compared with other five economies studied by WRI, material consumption intensity of Chengyang District is significantly lower than developed countries, which indicates that Chengyang District is still in a development stage The direct material productivity （actual GDP per DMI） increased 59.1% from 1995 to 2004 and has been higher than either of stadies in China, which indicates efficiency of resources utilization has improved obviously in Chengyang District. But there was significant increase in material input in the last decade, which shows that rapid increase of economy is highly dependent on requirement and consumption of natural resources. Therefore, in order to promote the sustainahility, it is essential to develop circular economy and improve utilization efficiency of resources.展开更多
The filler-bitumen interaction mechanism is one of the most essential phases for comprehending the asphalt mixture's performance.However,despite numerous studies,in-depth knowledge of filler-bitumen reciprocity at...The filler-bitumen interaction mechanism is one of the most essential phases for comprehending the asphalt mixture's performance.However,despite numerous studies,in-depth knowledge of filler-bitumen reciprocity at a microscale level is yet to be ascertained.The goal of this research is to gain a better understanding of the fillerbitumen microscale interaction in terms of the synergy and coaction between the physicochemical and rheological performance of mastics due to filler inclusions.The rheological properties of two sustainable mastics,dolomite powder(DP)and lime kiln dust(LKD),together with a neat PEN 60/70 binder,were analysed based on a temperature sweep at elevated temperature conditions.Meanwhile,frequency sweep and multiple stress creep recovery(MSCR)tests were also conducted at pavement serviceability temperature using the dynamic shear rheometer(DSR).Physicochemical tests using a scanning electron microscope(SEM)and energy dispersive X-rays(EDX)were conducted to analyse the impact of parameters such as particle shape,grain size,texture,and chemical compositions.The DSR test results showcased how the incorporation of fillers in asphalt binder considerably improved the performance of the binder in terms of rutting and fatigue.Likewise,its strain and nonrecoverable compliance parameters were substantially reduced at higher filler and binder concentrations.Physical filler attributes of low rigden voids(R.V),high fineness modulus(FM),and high specific surface area(SSA)led to greater interfacial stiffness and elasticity in LKD mastics compared to DP mastics at different loading frequencies and temperature levels.The SEM/EDX results also indicated that the elemental calcium and carbon composition of each filler component,together with its grain morphology,strongly influenced its rheological performance.展开更多
In this paper, the influence of different external wall insulation materials on the energy consumption of a newly built apartment in Germany is investigated. Three types of insulation materials commonly used in German...In this paper, the influence of different external wall insulation materials on the energy consumption of a newly built apartment in Germany is investigated. Three types of insulation materials commonly used in Germany including mineral fiber, polyurethane, and vacuum insula- tion panel are chosen for the case studies. An energy analysis model is established to clarify the primary energy use for production of the insulation materials and for building space heating. The calculation results show that the energy consumption for insulation material production increases with the insulation thickness, whereas the energy use for space heating decreases with the insulation thickness. Thus, there exists an optimum thickness to get the lowest total energy consumption for each kind of insulation material. The ascending order of the total energy consumption of the three materials is mineral fiber, polyurethane, and vacuum insulation panel. However, the optimum insulation thicknesses for the three insulation materials show a verse order at a certain heat transfer coefficient of the base envelope. The energy payback time （EPT） is proposed to calculate the payback time of the primary energy use for insulation material production. Mineral fiber has the shortest time, followed by poly- urethane and vacuum insulation panel. The EPTS is 10, 19 and 21 years, respectively when the heat transfer coefficient of the base envelope is 0.2 W/（m2.K）. In addition, the simulated results show that the theoretical value and the simulated value are basically identical.展开更多
This paper presents the parameter estimation methods of weighting coefficients in generalized weighted mean combining forecasting, and uses this forecasting model to forecast air materials consumption. Finially, the e...This paper presents the parameter estimation methods of weighting coefficients in generalized weighted mean combining forecasting, and uses this forecasting model to forecast air materials consumption. Finially, the efficiency of generalized weighted mean combining forecasting has been demonstrated by an example.展开更多
基金supported by National Natural Science Foundation of China(Nos.52174328 and 52474368)Fundamental Research Funds for Central Universities of Central South University(Nos.2022ZZTS0084 and 2024ZZTS0062).
文摘Reducing raw materials consumption(RMC)in electric arc furnace(EAF)steelmaking process is beneficial to the reduction in resource and energy consumption.The conventional indicator of evaluating RMC only focuses on EAF inputs and outputs,neglecting the associations between smelting operations and RMC.Traditional methods of reducing RMC rely on manual experience and lack a standard operation guidance.A method based on association rules mining and metallurgical mechanism(ARM-MM)was proposed.ARM-MM proposed an improved evaluation indicator of RMC and the indicator independently showed the associations between smelting operations and RMC.On the basis,1265 heats of real EAF data were used to obtain the operation guidance for RMC reduction.According to the ratio of hot metal(HM)in charge metals,data were divided into all dataset,low HM ratio dataset,medium HM ratio dataset,and high HM ratio dataset.ARM algorithm was used in each dataset to obtain specific operation guidance.The real average RMC under all dataset,medium HM ratio dataset,and high HM ratio dataset was reduced by 279,486,and 252 kg/heat,respectively,when obtained operation guidance was applied.
文摘1. RE Permanent Materials Chinese demand for RE permanent magnets increases at 20% per year. The output of sintered NdFeB magnets will reach 70,000 tons in 2010, 75% of the world total, with sales value of RMB $26 billion. 2. RE Catalyst
文摘Base on the framework of material flow analsis （MFA） proposed by Eurostat, this paper collected related data and conducted a regional MFA for the Chengyang Districgt in Qingdao. The indicators such as Direct Material Input（DMI）, Direct Material Consumption （DMC） and Exports are calculated or estimated for the period of year 1995 through 2004. Several derivable iudicators defining direct material productivity and material intenstiy are also evaluated and some valuable conclusions were drawn. DMI in absolute number increased from about 1645.9 kilotons in 1995to about 8052.5 kilotons in 2004. Imports contribute to about 47 to 69% of DMI, and the biggest component of imports is fossil fuel that approximatley accounts far 50% of imnports. DMI per capita of Chengyang District increased rapidly and reached 17. 4 tons in 2004. Compared with other five economies studied by WRI, material consumption intensity of Chengyang District is significantly lower than developed countries, which indicates that Chengyang District is still in a development stage The direct material productivity （actual GDP per DMI） increased 59.1% from 1995 to 2004 and has been higher than either of stadies in China, which indicates efficiency of resources utilization has improved obviously in Chengyang District. But there was significant increase in material input in the last decade, which shows that rapid increase of economy is highly dependent on requirement and consumption of natural resources. Therefore, in order to promote the sustainahility, it is essential to develop circular economy and improve utilization efficiency of resources.
文摘The filler-bitumen interaction mechanism is one of the most essential phases for comprehending the asphalt mixture's performance.However,despite numerous studies,in-depth knowledge of filler-bitumen reciprocity at a microscale level is yet to be ascertained.The goal of this research is to gain a better understanding of the fillerbitumen microscale interaction in terms of the synergy and coaction between the physicochemical and rheological performance of mastics due to filler inclusions.The rheological properties of two sustainable mastics,dolomite powder(DP)and lime kiln dust(LKD),together with a neat PEN 60/70 binder,were analysed based on a temperature sweep at elevated temperature conditions.Meanwhile,frequency sweep and multiple stress creep recovery(MSCR)tests were also conducted at pavement serviceability temperature using the dynamic shear rheometer(DSR).Physicochemical tests using a scanning electron microscope(SEM)and energy dispersive X-rays(EDX)were conducted to analyse the impact of parameters such as particle shape,grain size,texture,and chemical compositions.The DSR test results showcased how the incorporation of fillers in asphalt binder considerably improved the performance of the binder in terms of rutting and fatigue.Likewise,its strain and nonrecoverable compliance parameters were substantially reduced at higher filler and binder concentrations.Physical filler attributes of low rigden voids(R.V),high fineness modulus(FM),and high specific surface area(SSA)led to greater interfacial stiffness and elasticity in LKD mastics compared to DP mastics at different loading frequencies and temperature levels.The SEM/EDX results also indicated that the elemental calcium and carbon composition of each filler component,together with its grain morphology,strongly influenced its rheological performance.
基金This work was supported by the Natural Science Foundation of Tianjin, China （Grant No. 17JCZDJC31400） and the Scientific Special Commissioner of Tianjin, China （16JCTPJC52800）.
文摘In this paper, the influence of different external wall insulation materials on the energy consumption of a newly built apartment in Germany is investigated. Three types of insulation materials commonly used in Germany including mineral fiber, polyurethane, and vacuum insula- tion panel are chosen for the case studies. An energy analysis model is established to clarify the primary energy use for production of the insulation materials and for building space heating. The calculation results show that the energy consumption for insulation material production increases with the insulation thickness, whereas the energy use for space heating decreases with the insulation thickness. Thus, there exists an optimum thickness to get the lowest total energy consumption for each kind of insulation material. The ascending order of the total energy consumption of the three materials is mineral fiber, polyurethane, and vacuum insulation panel. However, the optimum insulation thicknesses for the three insulation materials show a verse order at a certain heat transfer coefficient of the base envelope. The energy payback time （EPT） is proposed to calculate the payback time of the primary energy use for insulation material production. Mineral fiber has the shortest time, followed by poly- urethane and vacuum insulation panel. The EPTS is 10, 19 and 21 years, respectively when the heat transfer coefficient of the base envelope is 0.2 W/（m2.K）. In addition, the simulated results show that the theoretical value and the simulated value are basically identical.
文摘This paper presents the parameter estimation methods of weighting coefficients in generalized weighted mean combining forecasting, and uses this forecasting model to forecast air materials consumption. Finially, the efficiency of generalized weighted mean combining forecasting has been demonstrated by an example.
