In district heating(DH) system with gas-fired peak load regulating boiler in the secondary network,by prolonging run time of base load plants under rated condition,the mean energy efficiency could be increased. The fu...In district heating(DH) system with gas-fired peak load regulating boiler in the secondary network,by prolonging run time of base load plants under rated condition,the mean energy efficiency could be increased. The fuels of the system,including coal and gas,would cause different environmental impacts. Meanwhile,the reliability of the heating networks would be changed because the peak load regulating boiler could work as a standby heat source. A model for assessment of heating system was established by value analysis to optimize this kind of system. Energy consumption,greenhouse gas emission,pollution emission and system reliability were selected as functional assessment indexes in the model. Weights of each function were determined by analytical hierarchy process (AHP) and experts consultation. Life cycle cost was used as the cost in the model. A real case as an example was discussed to obtain the optimal base load ratio. The result shows that the optimal base load ratio of the case is 0.77.展开更多
As the greenway construction grows popular,the concept and type of greenway is clarified in this study,research progresses and prospects of greenway planning are summarized.Greenway planning of Shunde District is take...As the greenway construction grows popular,the concept and type of greenway is clarified in this study,research progresses and prospects of greenway planning are summarized.Greenway planning of Shunde District is taken for an example to elaborate properties,types,origination and tasks of greenway,moreover,construction background,ecological,human-centered and characteristic design principles were analyzed,especially the design of its buffer zone,corridor system,width of crawl lane,node system,identification system and service area.Greenway construction of Shunde District is to build a greenway network of multiple types and functions in 3 levels:region,city and community;a recreational landscaping system with regional greenland as the background,greennet and greenway as the framework,to promote a new "ecological,green and low-carbon" lifestyle,and create the new image of Shunde as "a livable riverfront region full of sunshine".展开更多
Groundwater environment evolution can comprehensively reflect groundwater dynamics. Based on the relationship between the groundwater system and the external environment in Jinghuiqu irrigation district, adopting the ...Groundwater environment evolution can comprehensively reflect groundwater dynamics. Based on the relationship between the groundwater system and the external environment in Jinghuiqu irrigation district, adopting the Principal Component Analysis method, variation characteristics of environmental factors including climate and human activity and their impact on groundwater were systematically analyzed. The results show that groundwater level in Jinghuiqu irrigation district has been significantly dropped in nearly 34 years;the reduction of surface water irrigation use, which reduced the amounts of groundwater recharge and destroyed the water balance, is considered as the most direct cause for falling of regional groundwater level. Besides, reduction in precipitation, increase of evaporation also accelerated the declining of the groundwater level at some extent. Finally, a predicting method of groundwater depth based on BP neural network is developed. The experimental results show that the predicting model can reasonablely predict the groundwater level in Jinghuiqu irrigation district with a high precision.展开更多
电力和热力系统的耦合能促进可再生能源消纳、提升能源系统综合效率。先进绝热压缩空气储能(advanced adiabatic compressed air energy storage,AA-CAES)是一种大规模的清洁储能技术,具有多能联储、联供的潜力,可以作为集成电力和热力...电力和热力系统的耦合能促进可再生能源消纳、提升能源系统综合效率。先进绝热压缩空气储能(advanced adiabatic compressed air energy storage,AA-CAES)是一种大规模的清洁储能技术,具有多能联储、联供的潜力,可以作为集成电力和热力系统的能源枢纽。但当前其作为独立主体参与电力与热力市场的竞标机制尚未明确,且传统建模多采用类似电池储电模型,导致经济效益难以精准衡量。为此,提出了一种考虑热电联供的AA-CAES主从博弈竞标策略。首先,建立考虑各组件运行特性的AA-CAES热电联供数学模型;其次,建立单领导者-双追随者的主从博弈框架,上层以AA-CAES收益最大化为目标优化竞标标的,下层以社会福利最大化为目标实现市场出清;针对双层非线性模型的求解难题,采用Karush-Kuhn-Tucker(KKT)最优性条件和二进制扩展线性化方法转化为单层混合整数规划;最后,算例仿真表明,AA-CAES参与双重市场比参与电力市场收益提升了30.6%,其自身组件参数对收益影响明显,尤其是透平机等熵效率提升10%可使总收益增长28%,为AA-CAES的市场运营与参数优化提供关键参考。展开更多
文摘In district heating(DH) system with gas-fired peak load regulating boiler in the secondary network,by prolonging run time of base load plants under rated condition,the mean energy efficiency could be increased. The fuels of the system,including coal and gas,would cause different environmental impacts. Meanwhile,the reliability of the heating networks would be changed because the peak load regulating boiler could work as a standby heat source. A model for assessment of heating system was established by value analysis to optimize this kind of system. Energy consumption,greenhouse gas emission,pollution emission and system reliability were selected as functional assessment indexes in the model. Weights of each function were determined by analytical hierarchy process (AHP) and experts consultation. Life cycle cost was used as the cost in the model. A real case as an example was discussed to obtain the optimal base load ratio. The result shows that the optimal base load ratio of the case is 0.77.
文摘As the greenway construction grows popular,the concept and type of greenway is clarified in this study,research progresses and prospects of greenway planning are summarized.Greenway planning of Shunde District is taken for an example to elaborate properties,types,origination and tasks of greenway,moreover,construction background,ecological,human-centered and characteristic design principles were analyzed,especially the design of its buffer zone,corridor system,width of crawl lane,node system,identification system and service area.Greenway construction of Shunde District is to build a greenway network of multiple types and functions in 3 levels:region,city and community;a recreational landscaping system with regional greenland as the background,greennet and greenway as the framework,to promote a new "ecological,green and low-carbon" lifestyle,and create the new image of Shunde as "a livable riverfront region full of sunshine".
文摘Groundwater environment evolution can comprehensively reflect groundwater dynamics. Based on the relationship between the groundwater system and the external environment in Jinghuiqu irrigation district, adopting the Principal Component Analysis method, variation characteristics of environmental factors including climate and human activity and their impact on groundwater were systematically analyzed. The results show that groundwater level in Jinghuiqu irrigation district has been significantly dropped in nearly 34 years;the reduction of surface water irrigation use, which reduced the amounts of groundwater recharge and destroyed the water balance, is considered as the most direct cause for falling of regional groundwater level. Besides, reduction in precipitation, increase of evaporation also accelerated the declining of the groundwater level at some extent. Finally, a predicting method of groundwater depth based on BP neural network is developed. The experimental results show that the predicting model can reasonablely predict the groundwater level in Jinghuiqu irrigation district with a high precision.
文摘电力和热力系统的耦合能促进可再生能源消纳、提升能源系统综合效率。先进绝热压缩空气储能(advanced adiabatic compressed air energy storage,AA-CAES)是一种大规模的清洁储能技术,具有多能联储、联供的潜力,可以作为集成电力和热力系统的能源枢纽。但当前其作为独立主体参与电力与热力市场的竞标机制尚未明确,且传统建模多采用类似电池储电模型,导致经济效益难以精准衡量。为此,提出了一种考虑热电联供的AA-CAES主从博弈竞标策略。首先,建立考虑各组件运行特性的AA-CAES热电联供数学模型;其次,建立单领导者-双追随者的主从博弈框架,上层以AA-CAES收益最大化为目标优化竞标标的,下层以社会福利最大化为目标实现市场出清;针对双层非线性模型的求解难题,采用Karush-Kuhn-Tucker(KKT)最优性条件和二进制扩展线性化方法转化为单层混合整数规划;最后,算例仿真表明,AA-CAES参与双重市场比参与电力市场收益提升了30.6%,其自身组件参数对收益影响明显,尤其是透平机等熵效率提升10%可使总收益增长28%,为AA-CAES的市场运营与参数优化提供关键参考。
