期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
金家庄特长螺旋隧道施工通风方案优化分析 被引量:15
1
作者 罗燕平 韩景科 +2 位作者 文展 骆阳 刘甫 《隧道建设(中英文)》 北大核心 2019年第A01期385-391,共7页
为加快长大隧道施工进度,多采用开挖斜井增加工作面,而多工作面同时施工时,通风成为影响掘进速度的重要因素。以金家庄螺旋隧道斜井工区工程为依托,针对左线现有压入式通风方案工作面风量较小、通风效果较差的问题,提出风仓式通风方案... 为加快长大隧道施工进度,多采用开挖斜井增加工作面,而多工作面同时施工时,通风成为影响掘进速度的重要因素。以金家庄螺旋隧道斜井工区工程为依托,针对左线现有压入式通风方案工作面风量较小、通风效果较差的问题,提出风仓式通风方案。采用三维数值模型对2种方案的"风机-风管-隧道"系统进行计算分析,并将数值计算所得测点风速与现测数据进行校验。计算结果表明:1)现有压入式通风,风管供风量和洞内风速均不能满足隧道施工通风要求;2)采用风仓式通风方案后,能较好地控制工作面风管出口风量,使各工作面风量满足要求;3)风仓式通风具有灵活性,可随着隧道开挖进尺的增加,调节风仓内风机,控制工作面风量;4)风仓式通风能减少风管长度和转角,从而减少漏风量和风压损失,较好地为工作面提供风量。本文研究成果可为类似工程提供参考,具有实际工程意义。 展开更多
关键词 隧道 施工通风 风仓方案 数值计算 风管风量
下载PDF
基于大断面高铁隧道的施工通风时间理论预测方法研究 被引量:6
2
作者 王明年 邓涛 于丽 《隧道建设(中英文)》 北大核心 2018年第8期1279-1285,共7页
为了获得隧道施工中风管出口到掌子面的距离(以下简称"风管距离")以及风管出口风量对施工通风时间的影响规律,以郑万线机械配套施工的大断面高速铁路隧道为工程依托,采用CFD数值模拟和多项式拟合数值分析方法对1D、2D、3D、4... 为了获得隧道施工中风管出口到掌子面的距离(以下简称"风管距离")以及风管出口风量对施工通风时间的影响规律,以郑万线机械配套施工的大断面高速铁路隧道为工程依托,采用CFD数值模拟和多项式拟合数值分析方法对1D、2D、3D、4D(D为断面当量直径)的风管距离搭配2 000、2 500、3 000、3 500 m^3/min 4种风管出口风量作用下的最少通风时间进行研究。研究结果表明,施工通风时间受风管距离与风管出口风量2个因素的影响,通风时间t与风管距离x之间关系可以表示为t=ax^2+bx+c的形式,且式中各项系数均可以通过多项式拟合表达为风管出口风量Q的函数,故研究可得出通风时间t与风管距离、风管出口风量间的函数关系式为t=f(Q)x^2+g(Q)x+h(Q),同时运用该公式对向家湾隧道工程实例的通风时间进行预测。研究成果为郑万线隧道机械化快速施工通风时间的确定提供了理论指导,研究揭示的规律及所采用方法对类似隧道工程施工通风时间的确定具有一定的参考价值。 展开更多
关键词 高速铁路隧道 大断面隧道 施工通风 通风时间 风管出口风量 风管距离 CFD数值模拟
下载PDF
汽车滚装处所通风的数值计算及设计优化 被引量:3
3
作者 刘镇剑 东之杰 +1 位作者 郭轩 顾峰 《广东造船》 2019年第3期33-36,共4页
汽车滚装处所是汽车滚装船装载车辆的主要场所和危险区域,其通风设计非常关键。但常规的设计方法多依赖于设计经验或定性分析,对于大尺度、高复杂的滚装处所通风设计不够精确。本文采用CFD数值计算方法,对某型汽车滚装船的滚装处所进行... 汽车滚装处所是汽车滚装船装载车辆的主要场所和危险区域,其通风设计非常关键。但常规的设计方法多依赖于设计经验或定性分析,对于大尺度、高复杂的滚装处所通风设计不够精确。本文采用CFD数值计算方法,对某型汽车滚装船的滚装处所进行了数值计算和分析。针对单根风管,分析其压力损失和风量分配;针对整个滚装处所,分析其流场特性。根据计算分析的结果,对滚装处所的通风设计进行优化,达到提高通风效率的目的。 展开更多
关键词 汽车滚装处所 CFD数值计算 风管风量平衡分配 滚装处所流场特性 通风优化
下载PDF
Climate Change Risk Research: A Case Study on Flood Disaster Risk in China 被引量:4
4
作者 WU Shao-Hong PAN Tao HE Shan-Feng 《Advances in Climate Change Research》 SCIE 2012年第2期92-98,共7页
This paper discusses theories and methods of climate change risk studies for the research expansion in China. Climate change risks consist of three basic components including sensitivity, exposure, and possibility. Un... This paper discusses theories and methods of climate change risk studies for the research expansion in China. Climate change risks consist of three basic components including sensitivity, exposure, and possibility. Uncertainty, future events, damages, and relativity are the major features of climate change risk. Climate change risk research includes two key steps: risk assessment and risk management, the former is the process, and the latter is the ultimate goal which is the basis for actions to address climate change. We present the main framework and methods for climate change risk research. A case study on China's floods risk is taken as an example of climate change risk study. Finally, we point out main aspects of climate change risk research, including ensemble-based probabilistic projection, quantitative risk assessment, risk zoning and mapping, and risk management. 展开更多
关键词 climate change risk assessment risk management UNCERTAINTY
下载PDF
The FAHP-based Risk Assessment in the Conclusion of Equipment Procurement Contract
5
《International English Education Research》 2014年第10期14-16,共3页
The risk assessment of contract conclusion is the primary and key part of equipment purchase contract risk management. In this paper, based on the fuzzy characteristics of contract risks, and overcoming the traditiona... The risk assessment of contract conclusion is the primary and key part of equipment purchase contract risk management. In this paper, based on the fuzzy characteristics of contract risks, and overcoming the traditional disadvantages of analytic hierarchy process (AHP), the fuzzy analytic hierarchy process (FAHP) of contract conclusion is proposed for meeting the actual need of equipment procurement contract risk assessment, and implementing the risk factors qualitative and quantitative assessments of different working nodes in contract conclusion. Thus, a scientific and reliable important basis is provided for the risk management of equipment procurement contract. 展开更多
关键词 Equipment Procurement Contract CONCLUSION Risk Assessment FAHP
下载PDF
DYNAMIC CVAR WITH MULTI-PERIOD RISK PROBLEMS 被引量:1
6
作者 Zhiqing MENG Min JIANG Qiying HU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2011年第5期907-918,共12页
This paper studies multi-period risk management problems by presenting a dynamic risk measure. This risk measure is the sum of conditional value-at-risk of each period. The authors model it by Markov decision processe... This paper studies multi-period risk management problems by presenting a dynamic risk measure. This risk measure is the sum of conditional value-at-risk of each period. The authors model it by Markov decision processes and derive its optimality equation. This equation is further transformed equivalently to an analytically tractable one. The authors then use the model and its results to a multi-period portfolio optimization when the return rate vectors at each period form a Markov chain. 展开更多
关键词 α-CVaR MULTI-PERIOD optimality equation optimal policy.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部