Based on the analysis of actual energy consumptions during stevia sugar production,practical measures were proposed to save energy( gas,water and powder) consumption and reduce cost through waste heat recycle and ut...Based on the analysis of actual energy consumptions during stevia sugar production,practical measures were proposed to save energy( gas,water and powder) consumption and reduce cost through waste heat recycle and utilization,process improvement,equipment operation efficiency,application of newly energysaving equipment,and some project applications were provided as case study for some techniques and methods adopted in the production.展开更多
The rapid development of urban rail transit brings convenience to the public,but its huge energy consumption problem cannot be ignored.A microgrid composed of photovoltaic power generation unit,regenerative braking en...The rapid development of urban rail transit brings convenience to the public,but its huge energy consumption problem cannot be ignored.A microgrid composed of photovoltaic power generation unit,regenerative braking energy feedback unit and battery energy storage unit is proposed,which provides green power for the station.In order to suppress the fluctuation of photovoltaic power generation and the intermittence of regenerative braking feedback energy,the energy management mode of microgrid is designed according to the illumination situation,braking energy feedback situation,battery state of charge and so on.In addition,a coordination control method based on virtual synchronous generator(VSG)is proposed to realize smooth switching among modes.Finally,the proposed energy management and coordination control method for elevated station microgrid is verified by Matlab/Simulink.The results show that the elevated station microgrid can operate safely and reliably under various energy management modes and realize smooth switching among modes.展开更多
The Yangtze River Basin in China is characterised by hot-and cold-humid climates in summer and winter, respectively. Thus, increased demand for heating and cooling energy according to the season, as well as poor indoo...The Yangtze River Basin in China is characterised by hot-and cold-humid climates in summer and winter, respectively. Thus, increased demand for heating and cooling energy according to the season, as well as poor indoor thermal comfort, are inevitable. To overcome this problem, this study focused on the influence of passive design and heating, ventilation, and air conditioning equipment performance on the energy performance of residential buildings, and explored potential energy-saving technology paths involving passive design and improved coefficient of performance through a multi-objective and multi-parameter optimisation technique. A large-scale questionnaire survey covering a typical city was first conducted to identify family lifestyle patterns regarding time spent at home, family type, air conditioner use habits, indoor thermal comfort, etc. Then, the actual heating and cooling energy consumption and information of model building were determined for this region. Subsequently, the design parameters of an individual building were simulated using Energyplus to investigate the cooling and heating energy consumption for a typical residential building with an air conditioner. The results indicated an improvement of approximately 30% in energy efficiency through optimisation of the external-wall insulation thickness and the external-window and shading performance, and through use of appropriate ventilation technology. Thus, a multi-objective and multi-parameter optimisation model was developed to achieve comprehensive optimisation of several design parameters. Experimental results showed that comprehensive optimisation could not only reduce cooling and heating energy consumption, but also improve the thermal comfort level achieved with a non-artificial cooling and heating source. Finally, three energy-saving technology paths were formulated to achieve a balance between indoor thermal comfort improvement and the target energy efficiency(20 kWh/(m2?a)). The findings of this study have implications for the future design of buildings in the Yangtze River Basin, and for modification of existing buildings for improved energy efficiency.展开更多
针对混合关键级系统中的固定优先级任务节能问题,文中提出了基于概率性分析的混合关键级系统节能调度算法。混合关键级系统的实时性要求使得系统建模和分析偏向于较坏的情况。该类系统中出现任务超限的情况相对较少,易存在资源配置过度...针对混合关键级系统中的固定优先级任务节能问题,文中提出了基于概率性分析的混合关键级系统节能调度算法。混合关键级系统的实时性要求使得系统建模和分析偏向于较坏的情况。该类系统中出现任务超限的情况相对较少,易存在资源配置过度问题。通过DVFS(Dynamic Voltage Frequency Scaling)技术和混合关键级系统调度算法相结合的方式挖掘空闲时间,从而在保证系统实时性的前提下降低系统的能耗。利用MCSIMU仿真软件对所提算法进行了仿真验证,实验结果表明,对于固定优先级任务与未使用节能调度算法相比,固定优先级节能调度算法的节能率可达45%。展开更多
文摘Based on the analysis of actual energy consumptions during stevia sugar production,practical measures were proposed to save energy( gas,water and powder) consumption and reduce cost through waste heat recycle and utilization,process improvement,equipment operation efficiency,application of newly energysaving equipment,and some project applications were provided as case study for some techniques and methods adopted in the production.
基金National Natural Science Foundation of China(No.51367010)Science and Technology Program of Gansu Province(No.17JR5RA083)Program for Excellent Team of Scientific Research in Lanzhou Jiaotong University(No.201701)
文摘The rapid development of urban rail transit brings convenience to the public,but its huge energy consumption problem cannot be ignored.A microgrid composed of photovoltaic power generation unit,regenerative braking energy feedback unit and battery energy storage unit is proposed,which provides green power for the station.In order to suppress the fluctuation of photovoltaic power generation and the intermittence of regenerative braking feedback energy,the energy management mode of microgrid is designed according to the illumination situation,braking energy feedback situation,battery state of charge and so on.In addition,a coordination control method based on virtual synchronous generator(VSG)is proposed to realize smooth switching among modes.Finally,the proposed energy management and coordination control method for elevated station microgrid is verified by Matlab/Simulink.The results show that the elevated station microgrid can operate safely and reliably under various energy management modes and realize smooth switching among modes.
基金supported by the National Key R&D Programme “Solutions to Heating and Cooling of Buildings in the Yangtze River Region” (Grant No: 2016YFC0700301)the UK-China collaborative research project “Low carbon climate-responsive Heating and Cooling of Cities (LoHCool)” supported by the National Natural Science Foundation of China (NSFC Grant No. 51561135002)+1 种基金UK Engineering and Physical Sciences Research Council (EPSRC Grant No. EP/N009797/1)the China Scholarship Council (CSC) for one-year study at the University of Cambridge
文摘The Yangtze River Basin in China is characterised by hot-and cold-humid climates in summer and winter, respectively. Thus, increased demand for heating and cooling energy according to the season, as well as poor indoor thermal comfort, are inevitable. To overcome this problem, this study focused on the influence of passive design and heating, ventilation, and air conditioning equipment performance on the energy performance of residential buildings, and explored potential energy-saving technology paths involving passive design and improved coefficient of performance through a multi-objective and multi-parameter optimisation technique. A large-scale questionnaire survey covering a typical city was first conducted to identify family lifestyle patterns regarding time spent at home, family type, air conditioner use habits, indoor thermal comfort, etc. Then, the actual heating and cooling energy consumption and information of model building were determined for this region. Subsequently, the design parameters of an individual building were simulated using Energyplus to investigate the cooling and heating energy consumption for a typical residential building with an air conditioner. The results indicated an improvement of approximately 30% in energy efficiency through optimisation of the external-wall insulation thickness and the external-window and shading performance, and through use of appropriate ventilation technology. Thus, a multi-objective and multi-parameter optimisation model was developed to achieve comprehensive optimisation of several design parameters. Experimental results showed that comprehensive optimisation could not only reduce cooling and heating energy consumption, but also improve the thermal comfort level achieved with a non-artificial cooling and heating source. Finally, three energy-saving technology paths were formulated to achieve a balance between indoor thermal comfort improvement and the target energy efficiency(20 kWh/(m2?a)). The findings of this study have implications for the future design of buildings in the Yangtze River Basin, and for modification of existing buildings for improved energy efficiency.
文摘针对混合关键级系统中的固定优先级任务节能问题,文中提出了基于概率性分析的混合关键级系统节能调度算法。混合关键级系统的实时性要求使得系统建模和分析偏向于较坏的情况。该类系统中出现任务超限的情况相对较少,易存在资源配置过度问题。通过DVFS(Dynamic Voltage Frequency Scaling)技术和混合关键级系统调度算法相结合的方式挖掘空闲时间,从而在保证系统实时性的前提下降低系统的能耗。利用MCSIMU仿真软件对所提算法进行了仿真验证,实验结果表明,对于固定优先级任务与未使用节能调度算法相比,固定优先级节能调度算法的节能率可达45%。