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Green electricity hydrogen production(GEHP) is fundamental support for developing new-type power system (NPS) and achieving the green and low-carbon transformation in the transportation sector. It is key issue to build a hydrogen refueling facility network(HRFN) to link hydrogen production and consumption. Firstly, the framework of HRFN is proposed including hydrogen production points(HPP), hydrogen refueling stations(HRS) and hydrogen demand points(HDP). Secondly, a two-stage model is built. In the first stage, the siting model of HRS cluster is constructed considering the service capacity, service radius, and construction, operation and penalty costs. In the second stage, the bi-objective planning model of HRFN is constructed considering network stability, hydrogen storage and transportation forms and producing total costs. Finally, the Beijing-Tianjin-Hebei region of China(BTH) is taken as case study to verify the effectiveness. Sensitivity analyses are conducted on four factors:HRSs' service radius, service capacity, GEHP's efficiency and HDPs' scope. The key findings are: 1)the service radius and capacity of HRSs and HDPs' scope all affect the layout of HRSs, with HDPs' scope further influencing HPPs' number; 2)the construction and operation costs are more impacted by changes in GEHP's efficiency compared to network stability; 3)the network should be strengthened to cover the whole processes from hydrogen production to consumption. [ABSTRACT FROM AUTHOR]

In the context of rural revitalization, the needs of rural residents' travel and the theoretical construction of rural road network layout are extremely important. In order to improve the efficiency of rural road network, an algorithm based on topology theory was designed. The method is considered through the topology of the radial network and calculated with the characteristics of urban and rural traffic. According to the feature results, the target weight of the importance index of the traffic node was calculated by the gray correlation analysis method. Combined with the dynamic clustering results of traffic nodes, a rural road layout planning model was constructed, and this model was solved with the travel time as the goal to complete the design of this algorithm. The results show that on the basis of improving the efficiency, this algorithm can effectively improve the equilibrium and connectivity of urban and rural road distribution, compared with the traditional spline method and GIS-TransCAD method. [ABSTRACT FROM AUTHOR]

The layout of microseismic monitoring (MSM) station networks is very important to ensure the effectiveness of source location inversion; however, it is difficult to meet the complexity and mobility requirements of the technology in this new era. This paper proposes a network optimization method based on the geometric parameters of the proposed sensor-point database. First, according to the monitoring requirements and mine-working conditions, the overall proposed point database and model are built. Second, through the developed model, the proposed coverage area, envelope volume, effective coverage radius, and minimum energy level induction value are comprehensively calculated, and the evaluation reference index is constructed. Third, the effective maximum envelope volume is determined by taking the analyzed limit of monitoring induction energy level as the limit. Finally, the optimal design method is identified and applied to provide a sensor station layout network with the maximum energy efficiency. The method, defined as the S-V-E-R-V model, is verified by a comparison with the existing layout scheme and numerical simulation. The results show that the optimization method has strong practicability and efficiency, compared with the mine's layout following the current method. Simulation experiments show that the optimization effect of this method meets the mine's engineering requirements for the variability, intelligence, and high efficiency of the microseismic monitoring station network layout, and satisfies the needs of event identification and location dependent on the station network. [ABSTRACT FROM AUTHOR]

A reasonable regional integrated energy system (RIES) structure is the key to achieving its economic and efficient operation. However, in actual engineering construction, only the maximum load is considered as a prerequisite for energy design, which leads to waste of energy allocation. In view of this, this article proposes an electricity-thermal-cooling RIES energy stations and networks planning model that coordinates the operation of multiple-user loads, energy networks, and energy stations based on the idea of load clustering. Firstly, an average peak valley difference rate covering electricity, thermal, and cooling loads was proposed to evaluate the load characteristics of the RIES. Secondly, based on the load cluster characteristics and network costs of RIES, a RIES planning optimization framework is proposed, which includes load cluster division, RIES site selection and network planning, and RIES capacity planning. Thirdly, based on the P-median model and load cluster characteristics, establish an RIES location and network layout model. Fourthly, establish an RIES capacity planning model with the goal of annual total cost and carbon emissions. Finally, Dijkstra, improved particle swarm optimization, and VIKOR were used to solve the model. The results showed that the proposed model reduced the annual total cost by 7.13 % and the annual carbon emissions by 3.72 %. • Establish an average load peak valley difference index. • Establish a RIES planning framework includes network layout and capacity planning. • Establish an IES planning model with the goal of cost and carbon emissions. • Total annual cost decreased by 7.13 % and CO 2 emissions decreased by 2.77 %. [ABSTRACT FROM AUTHOR]

The understanding of complex biological networks often relies on both a dedicated layout and a topology. Currently, there are three major competing layout-aware systems biology formats, but there are no software tools or software libraries supporting all of them. This complicates the management of molecular network layouts and hinders their reuse and extension. In this paper, we present a high-level overview of the layout formats in systems biology, focusing on their commonalities and differences, review their support in existing software tools, libraries and repositories and finally introduce a new conversion module within the MINERVA platform. The module is available via a REST API and offers, besides the ability to convert between layout-aware systems biology formats, the possibility to export layouts into several graphical formats. The module enables conversion of very large networks with thousands of elements, such as disease maps or metabolic reconstructions, rendering it widely applicable in systems biology. [ABSTRACT FROM AUTHOR]

We undertake a sturdy body seismogenic model study along the northern margin of the West Qinling fault zone, China, to address some existing problems of neglecting scientific layout based on certain prediction theory and observation facts surrounding underground fluid monitoring networks across faults. A combination of high-density underground fluid measurements and vertical crustal deformation and seismological observations were used to elucidate the interplay between fluid dynamics, crustal deformation, and seismic activity and to comprehensively analyze the fault segment characteristics along the fault zone. We found correspondence between these parameters along the northern margin of the West Qinling fault zone. All parameters showed higher values in the Wu Shan (WS) segment than in the western Xia He–Huang Xiang Gou–Zhang Xian (XH-HXG-ZX) segment and eastern Tian Shui (TS) area. The 222Rn concentration reached 5.0942 at BZC, and the Hg concentration reached 3.4398 at LJG in WS. Similarly, the vertical crustal deformation and seismic activity in this area were both stronger than those in the western XH–HXG–ZX and TS area. Based on the sturdy body seismogenic model, we found that the ZX and TS segments exhibited weaker activity than the surrounding areas and may be in a deep locked state under the corresponding regional stress. Compared with existing monitoring network for background value detection and comprehensive research results, we propose a technical underground flow monitoring network prototype that includes two grade I and five grade II survey sites along the northern margin of the West Qinling fault zone based on the sturdy body seismogenic model. This prototype will provide a more reliable basis for earthquake prediction, tracking and mitigation, and disaster risk reduction. The presented scheme can be used as a guideline for deploying fault soil gas monitoring networks in China. • Seismogenic model validates soil gas monitoring network layout along a fault zone. • Soil gas observations effectively delineate inferred earthquake mechanisms. • Soil gas monitoring network can potentially capture evolution of a fault zone. [ABSTRACT FROM AUTHOR]

In network system design, it becomes more difficult to find the best network layout due to rapidly enhanced complexity. Because edges are costly and the budget is limited, the number of edges to connect target nodes is restricted to a narrow range, with the number of target nodes is given. Considering such a network system design problem that the number of nodes is given and the number of edges is fixed to a certain value, this paper identifies the best network layout based on factoring theory. We firstly enumerate all network layouts based on the concept of neighboring circle, secondly propose three propositions to logically classify these network layouts into different types, and finally compare the reliabilities of all types via factoring to identify the best network layout, which possesses the greatest reliability. Our best network layout identification approach is applicable to the reliability-constrained cost minimization problem and is expected to be very conducive to the efficiency improvement of the optimization problem. [ABSTRACT FROM AUTHOR]

Distributed and decentralised energy systems coupled with district heating networks are promising concepts for achieving less carbon-intensive urban energy systems. This paper investigates the optimal design and operation of distributed energy systems as well as optimal heating network layouts for different economic and environmental objectives. A mixed integer linear programming model was used for multi-objective optimisation to minimize total cost and carbon emissions. Improvements include the coupling of equipment and network modelling across many buildings, detailed CHP operational constraints, the inclusion of network heat losses, and improved modelling of thermal storage. The model was used on a case study consisting of eleven residential buildings and one commercial building for various design scenarios (available technologies, network layout limitations, operating constraints). Design results (capacities, network layouts) and operational results (energy supply breakdowns) are presented. The results show that district heating can deliver emissions savings of 23% over a standard solution for the same cost. The optimal number of heating network links increases as more stringent carbon emissions targets are implemented. Limits on possible network routes have significant impacts on the optimal technology capacities and on operational schedules. Also, commonly neglected constraints on CHP operation cause noticeably more reliance on district heating networks. [ABSTRACT FROM AUTHOR]

Optimal design of a natural gas network, which is supposed to convey natural gas from a supply point in south of Iran to some delivery points in north and northwest of Iran, is presented in this paper. Sum of investment and operating costs constitutes the objective function of the present study. A wide range of design parameters, including the network layout, diameter of each pipeline, pressure value at each supply or delivery node, as well as number and locations of compressor stations (CSs) on each pipeline, were considered in the optimization problem. A Genetic Algorithm (GA) which exploits "optimal properties of single pipelines" was presented and used as the optimization tool. Short computation time and repeatability of results ensures achieving the global optimum solution and are positive features of the proposed optimization algorithm. The optimal network design obtained from the optimization procedure consisted of 2660 km of pipelines and 26 CSs. It required a total annual cost of about 366.15 M$/year. The results explain why the layout with the shortest total length is not the optimal choice. [ABSTRACT FROM AUTHOR]

The paper presents a method for the design of a low-energy district heating (DH) system, concerning the studies of different pipe dimensioning methods, substation types and network layouts. Computations were carried out separately on each of the pipe segments of which the DH network consisted. A simultaneity factor was taken account in connection with each of these pipe segments. The applicability of the developed optimization method was investigated with outcomes of its being highly useful in the pipe dimensioning and of its being superior in respect to traditional dimensioning methods. It was shown that an appreciable reduction in heat loss from the DH network could be achieved. The optimal pipe dimensions found were evaluated by use of the commercial software Termis with input of several randomly generated heat demand scenarios involving peak winter conditions. The effects of the network type on the pipe dimensions were investigated for substations of different types containing buffer tanks and heat exchangers and for booster pumps installed at the DH network. Two types of network layouts were compared in terms of satisfaction of customers concerning the supply temperatures and heat loss within the DH network to prevent excessive drops in supply temperature during the summer months. [Copyright &y& Elsevier]

This paper presents an integrated approach to planning wellbore trajectory, submarine pipeline networks, routes and production for offshore shallow-water oil and gas fields. The method integrates the optimization of realistic drilling well paths, platform location and well allocation using a combination of Constrained Optimization by Linear Approximation (COBYLA) and Mixed Integer Linear Programming (MILP). It also optimizes the pipeline network layout using a separate MILP routine that compares and combines three types of pipeline connections, namely: star connections from multiple wellhead platforms to a central facility; subsea connections from platforms to a subsea tie-in point; or piggyback connections between the wellhead platforms themselves. Specific pipeline paths are found using a global graph-search method that is coupled with a local refinement to find the least-cost path. We demonstrate this pipeline path optimization by considering shallow-water offshore fields that include the presence of obstacles along the route. The pipeline network layout and route optimization steps are further integrated with techniques to estimate the production flow rate and optimal operating pressure across the resulting pipeline network. A case study is provided based on real conditions of Gulf of Mexico to test and validate the model, and to highlight the importance of the subsurface and surface integration for field development planning. [ABSTRACT FROM AUTHOR]

With the significant attention on global climate change, regional integrated energy systems (RIES) in low-carbon city planning has become one of the most important ways for global cities to achieve the goal of energy conservation and emission reduction. However, the planning strategy used in the primary stage of RIES establishment will greatly affect the system economy and environment. In view of the lack of planning guidance mechanisms for the large-scale RIES in China, a method for RIES preliminary overall planning, focused on energy types and use, is proposed in this paper. A graph theory-based mathematical optimal model was established with the lifetime costs of the whole system as the economic goal, and an improved Prim algorithm was put forward to solve the costs of the transmission and distribution network with the dynamic weight set of pipeline flow. The model was solved by an algorithm based on the idea of a dynamic minimum spanning tree and optimal path planning. The model and method were applied in a China–U.S. low-carbon demonstration city to verify feasibility and validity. The results could help us to comprehensively integrate regional energy and accurately plan future cities. [ABSTRACT FROM AUTHOR]