The surge in demand for renewable energy to combat the ever-escalating climate crisis promotes development of the energy-saving,carbon saving and reduction technologies.Shallow ground-source heat pump(GSHP)system is a...The surge in demand for renewable energy to combat the ever-escalating climate crisis promotes development of the energy-saving,carbon saving and reduction technologies.Shallow ground-source heat pump(GSHP)system is a promising carbon reduction technology that can stably and effectively exploit subsurface geothermal energy by taking advantage of load-bearing structural elements as heat transfer medium.However,the transformation of conventional geo-structures(e.g.piles)into heat exchangers between the ground and superstructures can potentially induce variable thermal axial stresses and displacements in piles.Traditional energy pile analysis methods often rely on deterministic and homogeneous soil parameter profiles for investigating thermo-mechanical soil-structure interaction,without consideration of soil spatial variability,model uncertainty or statistical uncertainty associated with interpolation of soil parameter profiles from limited site-specific measurements.In this study,a random finite difference model(FDM)is proposed to investigate the thermo-mechanical load-transfer mechanism of energy piles in granular soils.Spatially varying soil parameter profile is interpreted from limited site-specific measurements using Bayesian compressive sensing(BCS)with proper considering of soil spatial variability and other uncertainties in the framework of Monte Carlo simulation(MCS).Performance of the proposed method is demonstrated using an illustrative example.Results indicate that the proposed method enables an accurate evaluation of thermally induced axial stress/displacement and variation in null point(NP)location with quantified uncertainty.A series of sensitivity analyses are also carried out to assess effects of the pile-superstructure stiffness and measurement data number on the performance of the proposed method,leading to useful insights.展开更多
为减少高层装配式住宅的竖向变形,满足工程的实际使用功能,以山东省山东大学某26层装配整体式混凝土剪力墙住宅项目为研究对象,通过对变形情况进行模拟并对比实际施工情况,分析其变形发展变化的内在原因,包括:地基沉降、混凝土收缩徐变、...为减少高层装配式住宅的竖向变形,满足工程的实际使用功能,以山东省山东大学某26层装配整体式混凝土剪力墙住宅项目为研究对象,通过对变形情况进行模拟并对比实际施工情况,分析其变形发展变化的内在原因,包括:地基沉降、混凝土收缩徐变、预制构件连接工艺缺陷、短期施工荷载过早施加及温度应力等因素。采用建筑信息模型(building information modeling,BIM)+激光扫描实施纠偏技术、施工准备阶段三维可视化交底、施工阶段双重精度检测对比纠偏,结合沉降观测、施工预抛高等辅助措施,使竖向变形量降至10 mm,满足规范要求,并缩短了工期、降低了成本,验证了控制措施的有效性。展开更多
提出了一种高效可行的一次侧控制方法,用于混合型储能(hybrid energy storage system,HESS)与无线电能传输(wireless power transfer,WPT)系统,该方法能够使系统在混合储能单元不同充电状态下动态维持最大功率传输以及E类功率放大器(cla...提出了一种高效可行的一次侧控制方法,用于混合型储能(hybrid energy storage system,HESS)与无线电能传输(wireless power transfer,WPT)系统,该方法能够使系统在混合储能单元不同充电状态下动态维持最大功率传输以及E类功率放大器(class E power amplifier,Eop)的开关管处于软开关工作状态,确保混合型储能稳定高效地进行无线能量补充。系统拓扑由Eop、串联-串联(S-S)型WPT电路和HESS构成,基于对HESS不同充电模式下无线电能传输特性及Eop软开关特性的分析,提出了针对HESS无线充电的Eop最优频率追踪控制及Eop软开关占空比控制策略。该控制策略的优势是所有控制机构均位于发射侧,这样可有效减少接收侧储能单元的附加电路体积,提升系统的体积能量密度。最后,基于ZYNQ处理器搭建了实验样机,实验结果表明,该系统能够在混合储能不同充电状态及耦合条件下实现高效稳定的无线电能传输。展开更多
城市电网在发生N-1故障后,极可能新增运行风险,导致N-1-1时出现大面积停电事故。为管控城市电网N-1后运行风险,该文提出一种改进双智能体竞争双深度Q网络(dueling double deep Q network,D3QN)的城市电网N-1风险管控转供策略。根据风险...城市电网在发生N-1故障后,极可能新增运行风险,导致N-1-1时出现大面积停电事故。为管控城市电网N-1后运行风险,该文提出一种改进双智能体竞争双深度Q网络(dueling double deep Q network,D3QN)的城市电网N-1风险管控转供策略。根据风险管控原则,提出一种无需额外历史数据、考虑备自投装置、单供变电站风险和单供负荷母线风险的N-1场景指标;建立计及动作次序、指标间关系的负荷转供三阶段求解模型。以含预动作-变化探索值选择策略的改进双智能体D3QN方法,将负荷转供分为多个子转供环节学习,使转供思路清晰化,对动作空间进行降维,提高训练寻优效果,得到管控N-1风险的负荷转供策略。通过城市电网多场景算例分析,验证该文模型和方法的有效性。展开更多
基金The work described in this paper was supported by grants from the Research Grant Council of Hong Kong Special Administrative Region,China(Grants Nos.CityU 11213119 and CityU 11202121).The financial support is gratefully acknowledged.
文摘The surge in demand for renewable energy to combat the ever-escalating climate crisis promotes development of the energy-saving,carbon saving and reduction technologies.Shallow ground-source heat pump(GSHP)system is a promising carbon reduction technology that can stably and effectively exploit subsurface geothermal energy by taking advantage of load-bearing structural elements as heat transfer medium.However,the transformation of conventional geo-structures(e.g.piles)into heat exchangers between the ground and superstructures can potentially induce variable thermal axial stresses and displacements in piles.Traditional energy pile analysis methods often rely on deterministic and homogeneous soil parameter profiles for investigating thermo-mechanical soil-structure interaction,without consideration of soil spatial variability,model uncertainty or statistical uncertainty associated with interpolation of soil parameter profiles from limited site-specific measurements.In this study,a random finite difference model(FDM)is proposed to investigate the thermo-mechanical load-transfer mechanism of energy piles in granular soils.Spatially varying soil parameter profile is interpreted from limited site-specific measurements using Bayesian compressive sensing(BCS)with proper considering of soil spatial variability and other uncertainties in the framework of Monte Carlo simulation(MCS).Performance of the proposed method is demonstrated using an illustrative example.Results indicate that the proposed method enables an accurate evaluation of thermally induced axial stress/displacement and variation in null point(NP)location with quantified uncertainty.A series of sensitivity analyses are also carried out to assess effects of the pile-superstructure stiffness and measurement data number on the performance of the proposed method,leading to useful insights.
文摘为减少高层装配式住宅的竖向变形,满足工程的实际使用功能,以山东省山东大学某26层装配整体式混凝土剪力墙住宅项目为研究对象,通过对变形情况进行模拟并对比实际施工情况,分析其变形发展变化的内在原因,包括:地基沉降、混凝土收缩徐变、预制构件连接工艺缺陷、短期施工荷载过早施加及温度应力等因素。采用建筑信息模型(building information modeling,BIM)+激光扫描实施纠偏技术、施工准备阶段三维可视化交底、施工阶段双重精度检测对比纠偏,结合沉降观测、施工预抛高等辅助措施,使竖向变形量降至10 mm,满足规范要求,并缩短了工期、降低了成本,验证了控制措施的有效性。
文摘提出了一种高效可行的一次侧控制方法,用于混合型储能(hybrid energy storage system,HESS)与无线电能传输(wireless power transfer,WPT)系统,该方法能够使系统在混合储能单元不同充电状态下动态维持最大功率传输以及E类功率放大器(class E power amplifier,Eop)的开关管处于软开关工作状态,确保混合型储能稳定高效地进行无线能量补充。系统拓扑由Eop、串联-串联(S-S)型WPT电路和HESS构成,基于对HESS不同充电模式下无线电能传输特性及Eop软开关特性的分析,提出了针对HESS无线充电的Eop最优频率追踪控制及Eop软开关占空比控制策略。该控制策略的优势是所有控制机构均位于发射侧,这样可有效减少接收侧储能单元的附加电路体积,提升系统的体积能量密度。最后,基于ZYNQ处理器搭建了实验样机,实验结果表明,该系统能够在混合储能不同充电状态及耦合条件下实现高效稳定的无线电能传输。
文摘城市电网在发生N-1故障后,极可能新增运行风险,导致N-1-1时出现大面积停电事故。为管控城市电网N-1后运行风险,该文提出一种改进双智能体竞争双深度Q网络(dueling double deep Q network,D3QN)的城市电网N-1风险管控转供策略。根据风险管控原则,提出一种无需额外历史数据、考虑备自投装置、单供变电站风险和单供负荷母线风险的N-1场景指标;建立计及动作次序、指标间关系的负荷转供三阶段求解模型。以含预动作-变化探索值选择策略的改进双智能体D3QN方法,将负荷转供分为多个子转供环节学习,使转供思路清晰化,对动作空间进行降维,提高训练寻优效果,得到管控N-1风险的负荷转供策略。通过城市电网多场景算例分析,验证该文模型和方法的有效性。
