Controlled blasting techniques are used to control overbreak and to aid in the stability of the remaining rock formation. Presplitting is one of the most common methods which is used in many open pit mining and surfac...Controlled blasting techniques are used to control overbreak and to aid in the stability of the remaining rock formation. Presplitting is one of the most common methods which is used in many open pit mining and surface blast design. The purpose of presplitting is to form a fracture plane across which the radial cracks from the production blast cannot travel. The purpose of this study is to investigate of effect of presplitting on the generation of a smooth wall in continuum and jointed rock mass. The 2D distinct element code was used to simulate the presplitting in a rock slope. The blast load history as a function of time was applied to the inner wall of each blasthole. Important parameters that were considered in the analysis were stress tensor and fracturing pattern. The blast loading magnitude and blasthole spacing and jointing pattern were found to be very significant in the final results.展开更多
提出了一种考虑人员占用影响的集成楼宇暖通空调(heating,ventilation and air conditioning,HVAC)负荷群配电电网优化方法。首先,依据建筑围护热阻热容网络和配电网支路潮流方程构建了集成暖通空调负荷群配电网数学模型。其次,利用梯...提出了一种考虑人员占用影响的集成楼宇暖通空调(heating,ventilation and air conditioning,HVAC)负荷群配电电网优化方法。首先,依据建筑围护热阻热容网络和配电网支路潮流方程构建了集成暖通空调负荷群配电网数学模型。其次,利用梯形隶属度函数模糊化占用人数并考虑其对暖通空调负荷温度调控的影响,形成包含占用松弛函数约束的暖通空调负荷群与配电网联合优化方法。最后,通过模型预测控制方法实现了集成楼宇暖通空调负荷群配电网的滚动优化控制。改进的IEEE33节点配电网系统仿真结果表明,所提出的计及占用影响的联合优化模型,在楼宇侧能够满足人员热舒适性,同时减少楼宇暖通空调负荷能耗,在电网侧则减少配电网线路损耗和节点电压的波动,有效提高楼宇侧和电网侧整体的节能水平。展开更多
文摘Controlled blasting techniques are used to control overbreak and to aid in the stability of the remaining rock formation. Presplitting is one of the most common methods which is used in many open pit mining and surface blast design. The purpose of presplitting is to form a fracture plane across which the radial cracks from the production blast cannot travel. The purpose of this study is to investigate of effect of presplitting on the generation of a smooth wall in continuum and jointed rock mass. The 2D distinct element code was used to simulate the presplitting in a rock slope. The blast load history as a function of time was applied to the inner wall of each blasthole. Important parameters that were considered in the analysis were stress tensor and fracturing pattern. The blast loading magnitude and blasthole spacing and jointing pattern were found to be very significant in the final results.
文摘提出了一种考虑人员占用影响的集成楼宇暖通空调(heating,ventilation and air conditioning,HVAC)负荷群配电电网优化方法。首先,依据建筑围护热阻热容网络和配电网支路潮流方程构建了集成暖通空调负荷群配电网数学模型。其次,利用梯形隶属度函数模糊化占用人数并考虑其对暖通空调负荷温度调控的影响,形成包含占用松弛函数约束的暖通空调负荷群与配电网联合优化方法。最后,通过模型预测控制方法实现了集成楼宇暖通空调负荷群配电网的滚动优化控制。改进的IEEE33节点配电网系统仿真结果表明,所提出的计及占用影响的联合优化模型,在楼宇侧能够满足人员热舒适性,同时减少楼宇暖通空调负荷能耗,在电网侧则减少配电网线路损耗和节点电压的波动,有效提高楼宇侧和电网侧整体的节能水平。
