南京地铁一号线南京站车站隧道设计

地铁南京站采用双洞式隧道过站,隧道埋深浅,控制因素多,先前国内没有类似工程经验,文章通过对设计方案、结构计算及铁路线路防护措施等介绍,为今后类似工程提供设计参考.     

既有地下结构安全性鉴定研究

上世纪70年代初哈尔滨市按照当时地铁限界标准修建了一条地下人防工程(即7381工程),隧道穿越粉质粘土、细砂土层,埋深10～20 m.为了评价7381工程现在用于地铁运营的安全性,从结构承载能力、构造、变形和裂缝等方面进行了详细检测,主要内容包括混凝土强度、混凝土碳化、混凝土表面裂缝、钢筋强度及锈蚀、隧道衬砌拱顶厚度等.在检测结果基础上,对主洞衬砌和车站三联拱的承载能力进行了计算.通过多种力学模型讨论衬砌所承受的围岩压力,并依据比较结果,推荐泰沙基模型.计算结果表明衬砌结构承载能力满足现行有关规范要求.对衬砌存在的损伤和劣化进行了机理分析,并提出了有针对性的治理方法.结合地质勘查结果和衬砌结构使用寿命评估结果得出:哈尔滨7381工程经整治后可以用于地铁运营,其剩余使用寿命估算为80年.     

基于变基增量动态规划梯级水电站短期优化调度研究

为提高梯级水电站整体效益,以松江河梯级水电站为例,建立了耗水量最小和耗水能量最小梯级 水电站短期优化调度数学模型,应用变基增量动态规划法,以总耗水量最小和总耗水能量最小为最优化 准则计算分析了两个计划日的梯级水电站短期优化调度。结果表明,耗水能量最小数学模型作为梯级水 电站短期优化调度的最优化准则更为准确;变基增量动态规划法求解时间短、精度高。     

The impact of hydrogen refueling station subsidy strategy on China's hydrogen fuel cell vehicle market diffusion

Lack of hydrogen refueling stations (HRSs) has hindered the diffusion of hydrogen fuel cell vehicles (HFCVs) in the Chinese transport market. By combining the agent-based model (ABM) and the experience weighted attraction (EWA) learning algorithm, this paper explores the impact of government subsidy strategy for HRSs on the market diffusion of HFCVs. The actions of the parties (government, HRS planning department and consumers) and their interactions are taken into account. The new model suggests dynamic subsidy mode based on EWA algorithm yields better results than static subsidy mode: HFCV purchases, HRS construction effort, total number of HRSs and expected HRS planning department profits all outperform static data by around 27%. In addition, choosing an appropriate initial subsidy strategy can increase the sales of HFCVs by nearly 40%. Early investment from government to establish initial HRSs can also increase market diffusion efficiency by more than 76.7%.     

Two-stage stochastic-based scheduling of multi-energy microgrids with electric and hydrogen vehicles charging stations,considering transactions through pool market and bilateral contracts

In order to mitigate greenhouse gas emissions and improve energy efficiency, sustainable energy systems such as multi-energy microgrids (MEMGs) with the high penetration of renewable energy resources (RES) and satisfying different energy needs of consumers have received significant attention in recent years. MEMGs, by relying on renewable resources and energy storage systems along with energy conversion systems, play an essential role in sustainability of energy supply. However, renewable energies are uncertain due to the intermittent nature of solar and wind energy sources. Thus, optimal operation of the MEMGs with the consideration of the uncertainties of RES is necessary to achieve sustainability. In this paper, risk constrained scheduling of a MEMG is carried out with the presence of the PV, wind, biomass, electric vehicles (EVs) and hydrogen vehicles (HVs) charging stations, combined heat and power (CHP), boiler, hydrogen electrolyzer (HE), cryptocurrency miners (CMs), electrical, thermal and hydrogen storage systems, responsive demands. From the trading and business model side, the proposed MEMG optimized operation relies on bilateral contracts between producers and consumers and pool electricity markets. A two-stage stochastic programming method is used for considering the uncertainties of electrical, thermal and hydrogen demands, EV and HV charging stations load, CM load, PV and wind power, and the price of electricity purchased from the pool market. The proposed mixed integer linear programming (MILP) model is solved using the CPLEX solver in GAMS which guarantees to achieve a globally optimal solution. The results show that due to the certain prices of bilateral contracts, the possibility of transaction by bilateral contracts decreases the risk metric CVaR by 50.42%. The simulation results demonstrate that risk of high operation costs while considering flexibility sources, such as storages and demand response (DR) programs, is decreased by 5.45% and 4.6%, respectively. As far as operation costs are concerned, results reveal that using renewable resources decreases operation costs by 34.47%. Moreover, the operation cost is reduced by 5.94% and 4.57% in the presence of storage units and DR programs, respectively. In the same way, storages and DR programs decrease cost of purchased electricity by 13.47% and 14.46%, respectively.     

Research on Combined Construction Technology for Cross-Subway Tunnels in Underground Spaces

Given the increasingly notable segmentation of underground space by existing subway tunnels, it is difficult to effectively and adequately develop and utilize underground space in busy parts of a city. This study presents a combined construction technology that has been developed for use in underground spaces; it includes a deformation buffer layer, a special grouting technique, jump excavation by compartment, back-pressure portal frame technology, a reinforcement technique, and the technology of a steel portioning drum or plate. These technologies have been successfully used in practical engineering. The combined construction technology presented in this paper provides a new method of solving key technical problems in underground spaces in effectively used cross-subway tunnels. As this technology has achieved significant economic and social benefits, it has valuable future applications.     

Active–reactive power approaches for optimal placement of charge stations in power systems

Electric Vehicles (EVs) have been suggested as alternatives to conventional vehicles for reducing petrol consumption and carbon dioxide (CO₂) emissions. When a large number of EVs connect to the grid, they can cause a large amount of power loss. Where to install multiple charge stations in the grid, so as to mitigate losses caused by EVs when providing energy to those EVs, is becoming vitally important. In this paper, a distribution test-network model is described. A new analytical method is proposed, using the stations’ cooperation in terms of optimal active and reactive power dispatch as well as power flow analysis for locating the optimal placement of charge stations, so as to reduce power losses. This method is compared with the previously developed current density method for single charge stations using system simulation results. It was demonstrated that the methods proposed in this paper are more accurate than the current density method, and that 17% of the average active power loss can be saved for three different types of load profile. In addition, 27% of the average active power loss was saved by installing two charge stations rather than no charge stations in the test-line. It is shown that this could represent a 2.6% annual yield above inflation for investing in installing and running such charge stations.     

某地区盾构施工引起的土层沉降变形分析

为研究盾构施工引起的地面沉降,选取宁波地区有代表性的典型土层,运用经验公式与数值模拟相结合的方法,定性分析了盾构施工扰动引起的各土层沉降曲线形态。提出了初始敏感因子和深度敏感因子的概念,推导得出了各典型土层的敏感因子的初步建议值,详细阐述了地面沉降与盾构埋深的线形相关性。为盾构近距离穿越重大管线或建、构筑物等风险点时穿越土层的选择提供了理论参考,对地铁线路平、纵断面确定具有指导意义。     

Development of strategic hydrogen refueling station deployment plan for Korea

The Republic of Korea government has set yearly targets of hydrogen cars and buses and plans to install hydrogen refueling stations nationwide. This paper proposes a methodology for developing a strategic deployment plan with three mathematical models. For a given target, future refueling demand locations and amount from general road and expressway are systematically estimated. First, the required number of refueling stations to satisfy the target covering ratio of the total demand set by the government is determined by the Station number determination model. Next, the locations of the capacitated stations and the allocation of demand to the stations are determined by the second Max cover and the third p-median models. Since the max covering is more important than minimizing the travel time, the two models are used sequentially. The nationwide hydrogen station deployment plan for the years 2022–2040 obtained by the proposed methodology is reported.     

不同本构模型下建筑荷载对近邻地铁的沉降影响分析

针对高层建筑施工对近邻地铁隧道产生的影响,采用MC模型及CY模型两种土体本构模型,预测分析新建高层建筑荷载对紧邻地铁区间隧道及周边地表的沉降影响。结果显示,在计算参数均相同的条件下,两种本构模型得到的建筑荷载对周边土体的影响范围是一致的,但是该影响范围内的地表及隧道结构竖向沉降差异较大;根据工程经验,认为CY模型更符合真实情况。