Analytic hierarchy process(Group AHP) is combined with two different methods of assigning experts' priority to weight indicators in building energy efficiency assessment.One is to assign the experts' priority ...Analytic hierarchy process(Group AHP) is combined with two different methods of assigning experts' priority to weight indicators in building energy efficiency assessment.One is to assign the experts' priority averagely,and the other is to use cluster analysis to assign experts' priority.The results show that,1) Different expert's priority assigns result in great different weights of indicators in building energy efficiency assessment,therefore,the method of assigning experts' priority should be taken into account carefully while weighting indicators of building energy efficiency assessment using Group AHP;2) Three indicators are found to be overwhelmingly important in residential building energy efficiency assessment in the hot summer and cold winter zone in China.They are 'Outdoor & indoor shadow','Heating & air-conditioning facilities' and 'Insulation of envelope';3) The method combining cluster analysis with Group AHP to weight indicator of building energy efficiency assessment has the advantage of finding overwhelming important indicator,whereas,some less important indicators have a tendency to be ignored.A useful reference is provided for building energy conservation including policy revision and energy efficient residential building design.展开更多
At present,the proportion of new energy in the power grid is increasing,and the random fluctuations in power output increase the risk of cascading failures in the power grid.In this paper,we propose a method for ident...At present,the proportion of new energy in the power grid is increasing,and the random fluctuations in power output increase the risk of cascading failures in the power grid.In this paper,we propose a method for identifying high-risk scenarios of interlocking faults in new energy power grids based on a deep embedding clustering(DEC)algorithm and apply it in a risk assessment of cascading failures in different operating scenarios for new energy power grids.First,considering the real-time operation status and system structure of new energy power grids,the scenario cascading failure risk indicator is established.Based on this indicator,the risk of cascading failure is calculated for the scenario set,the scenarios are clustered based on the DEC algorithm,and the scenarios with the highest indicators are selected as the significant risk scenario set.The results of simulations with an example power grid show that our method can effectively identify scenarios with a high risk of cascading failures from a large number of scenarios.展开更多
为提高相变屋面的性能,本文提出了一种冷却塔-内嵌管式相变屋面复合降温系统。基于焓法,建立了系统的数值计算传热模型,数值研究了该系统在福州地区的热性能及节能潜力,探讨了相变材料相变温度、相变材料导热系数以及内嵌管间距的影响,...为提高相变屋面的性能,本文提出了一种冷却塔-内嵌管式相变屋面复合降温系统。基于焓法,建立了系统的数值计算传热模型,数值研究了该系统在福州地区的热性能及节能潜力,探讨了相变材料相变温度、相变材料导热系数以及内嵌管间距的影响,并与传统的无内嵌管相变屋面进行了对比分析。研究发现,相变温度越高,复合降温系统的相变材料越容易完成凝固,但潜热利用率随相变温度的升高呈现先增加后降低的趋势。当相变温度由35℃升高到41℃时,屋面的累计冷负荷由383 k J/m^(2)增大到400 k J/m^(2),增加了4.4%。相变材料导热系数越高、内嵌管间距越小,复合降温系统相比于传统无内嵌管相变屋面的潜热利用优势越显著。当导热系数由0.2 W/(m·K)增加到0.8 W/(m·K)时,复合降温系统的潜热利用率和屋面累计冷负荷分别增加了36.3%和5.1%,而无内嵌管相变屋面的潜热利用率和屋面累计冷负荷分别升高了33.1%和6.3%。当内嵌管间距由500 mm减少到100 mm时,复合降温系统比传统无内嵌管相变屋面的潜热利用提高率由2.7%增大到16.3%,累计冷负荷降低率由3.8%升高到10.9%。研究结果可促进建筑节能和双碳目标的实现。展开更多
The investigation is generalized to clusters with sizes up to 3000 atoms, covering this way the range of sizes experimentally available for low energy cluster beam deposition. The atomic scale modeling is carried on b...The investigation is generalized to clusters with sizes up to 3000 atoms, covering this way the range of sizes experimentally available for low energy cluster beam deposition. The atomic scale modeling is carried on by both Molecular Dynamics and Metropolis Monte Carlo. This represents a huge series of simulations (175 cases) to which further calculations are added by spot when finer tuning of the parameters is necessary. Analyzing the results is a major task which is still in progress. This way, not only a realistic range of sizes is covered, but also the whole range of compositions and the temperature range relevant to the solid and the liquid states.展开更多
基金Project(2010R10036) supported by the Science and Technology Department of Zhejiang Province, China
文摘Analytic hierarchy process(Group AHP) is combined with two different methods of assigning experts' priority to weight indicators in building energy efficiency assessment.One is to assign the experts' priority averagely,and the other is to use cluster analysis to assign experts' priority.The results show that,1) Different expert's priority assigns result in great different weights of indicators in building energy efficiency assessment,therefore,the method of assigning experts' priority should be taken into account carefully while weighting indicators of building energy efficiency assessment using Group AHP;2) Three indicators are found to be overwhelmingly important in residential building energy efficiency assessment in the hot summer and cold winter zone in China.They are 'Outdoor & indoor shadow','Heating & air-conditioning facilities' and 'Insulation of envelope';3) The method combining cluster analysis with Group AHP to weight indicator of building energy efficiency assessment has the advantage of finding overwhelming important indicator,whereas,some less important indicators have a tendency to be ignored.A useful reference is provided for building energy conservation including policy revision and energy efficient residential building design.
基金funded by the State Grid Limited Science and Technology Project of China,Grant Number SGSXDK00DJJS2200144.
文摘At present,the proportion of new energy in the power grid is increasing,and the random fluctuations in power output increase the risk of cascading failures in the power grid.In this paper,we propose a method for identifying high-risk scenarios of interlocking faults in new energy power grids based on a deep embedding clustering(DEC)algorithm and apply it in a risk assessment of cascading failures in different operating scenarios for new energy power grids.First,considering the real-time operation status and system structure of new energy power grids,the scenario cascading failure risk indicator is established.Based on this indicator,the risk of cascading failure is calculated for the scenario set,the scenarios are clustered based on the DEC algorithm,and the scenarios with the highest indicators are selected as the significant risk scenario set.The results of simulations with an example power grid show that our method can effectively identify scenarios with a high risk of cascading failures from a large number of scenarios.
文摘为提高相变屋面的性能,本文提出了一种冷却塔-内嵌管式相变屋面复合降温系统。基于焓法,建立了系统的数值计算传热模型,数值研究了该系统在福州地区的热性能及节能潜力,探讨了相变材料相变温度、相变材料导热系数以及内嵌管间距的影响,并与传统的无内嵌管相变屋面进行了对比分析。研究发现,相变温度越高,复合降温系统的相变材料越容易完成凝固,但潜热利用率随相变温度的升高呈现先增加后降低的趋势。当相变温度由35℃升高到41℃时,屋面的累计冷负荷由383 k J/m^(2)增大到400 k J/m^(2),增加了4.4%。相变材料导热系数越高、内嵌管间距越小,复合降温系统相比于传统无内嵌管相变屋面的潜热利用优势越显著。当导热系数由0.2 W/(m·K)增加到0.8 W/(m·K)时,复合降温系统的潜热利用率和屋面累计冷负荷分别增加了36.3%和5.1%,而无内嵌管相变屋面的潜热利用率和屋面累计冷负荷分别升高了33.1%和6.3%。当内嵌管间距由500 mm减少到100 mm时,复合降温系统比传统无内嵌管相变屋面的潜热利用提高率由2.7%增大到16.3%,累计冷负荷降低率由3.8%升高到10.9%。研究结果可促进建筑节能和双碳目标的实现。
文摘The investigation is generalized to clusters with sizes up to 3000 atoms, covering this way the range of sizes experimentally available for low energy cluster beam deposition. The atomic scale modeling is carried on by both Molecular Dynamics and Metropolis Monte Carlo. This represents a huge series of simulations (175 cases) to which further calculations are added by spot when finer tuning of the parameters is necessary. Analyzing the results is a major task which is still in progress. This way, not only a realistic range of sizes is covered, but also the whole range of compositions and the temperature range relevant to the solid and the liquid states.
