scholarly journals A Gas Distribution Network Hydraulic Problem from Practice

2017 ◽  
Author(s):  
D. Brikić
Keyword(s):  
Natural Gas ◽  
Friction Factor ◽  
Gas Flow ◽  
Optimization Problem ◽  
Distribution Network ◽  
Gas Distribution ◽  
Pipeline Network ◽  
Hardy Cross ◽  
Selection Of

Accent is on determination of appropriate friction factor, and on selection of representative equation for natural gas flow under presented conditions in the network. Calculation of presented looped gas-pipeline network is done according to principles of Hardy Cross method. The final flows were calculated, for known pipes diameters and nodes consumptions while the flow velocities through pipes have to stand below certain values. In optimization problem flows are treated as constant, while the diameters are variables.

scholarly journals Similarities and Differences in Optimization of Water- and Gas- Distribution Pipeline Networks

2018 ◽  
Author(s):  
Dejan Brkić
Keyword(s):  
Natural Gas ◽  
Friction Factor ◽  
Gas Flow ◽  
Flow Equations ◽  
Water Pipelines ◽  
Pipeline Networks ◽  
Hardy Cross ◽  
Simple Network ◽  
Selection Of

Accent is on determination of appropriate friction factor of the pipes and on selection of the representative equation for water or natural gas flow which is valuable for existing conditions in the looped network of pipelines. Note that in a municipal gas pipeline, natural gas can be treated as incompressible fluid (liquid) i.e. as water or oil. Even under this circumstance, calculation of water pipelines cannot be literary copied and applied for calculation of gas pipelines. Inappropriate friction factor, equally as e.g. inappropriate usage of water flow equations for calculation of gas networks can lead to inaccurate final results. Few iterative methods for determining the optimal hydraulic solution of water- and gas- looped pipeline networks, such as, Hardy Cross, modified Hardy Cross, node-loop method, node and M.M. Andrijashev method, will be shown. Speed of convergence will be compared and discussed using a simple network with three loops.

scholarly journals Influence of Friction Factor and Flow Equation on Calculation of Gas-Distribution Pipeline Networks

2018 ◽  
Author(s):  
Dejan Brkić
Keyword(s):  
Friction Factor ◽  
Gas Flow ◽  
Flow Equation ◽  
Gas Distribution ◽  
Pipeline Networks ◽  
Hardy Cross ◽  
Accurate Procedure ◽  
Selection Of

Here is shown method for the hydraulic solution of a looped gas-pipeline networks. Calculation of presented network is done according to principles of Hardy Cross method. The optimization was carried out by iteration of the pipes diameters, node consumptions are known and flow velocities through pipes have to stand below certain values. Accent is on determination of appropriate friction factor, and on selection of representative equation for natural gas flow under presented conditions in the network. Inappropriate usage of friction factor, equally as inappropriate usage of gas flow equation can lead to inaccurate final results. Here is shown new facts in comparison to previous calculation of gas distribution network in Kragujevac, Serbia which is done in 1994. After the implementation, measurements in situ have performed, and real measured values deviate from calculated. Causes for these errors are investigated, and improved and more accurate procedure is shown.

scholarly journals Gas distribution network topology problem

2017 ◽  
Author(s):  
Dejan Brkić
Keyword(s):  
Nonlinear Problem ◽  
Network Topology ◽  
Iterative Procedure ◽  
Gas Flow ◽  
Distribution Network ◽  
Gas Pipeline ◽  
Gas Distribution ◽  
Pipeline Network ◽  
Loop Matrix ◽  
Looped Network

Problem of gas flow in looped network is nonlinear problem and these kind of problemshave to be solved using some kind of iterative procedure. For the pipeline network, two topologymatrices can be written; i.e. loop matrix and node matrix. The node matrix is related to therst Kirchho's law while the loop matrix is related to second Kirchho's law. Here will beshown ecient method in which both matrices, i.e. the node and the loop matrix are unitedin one coherent procedure for solution of looped gas pipeline problem.

scholarly journals ЩОДО ВЕРИФІКАЦІЇ ЕКОНОМІЧНОЇ МОДЕЛІ ТАРИФУ НА РОЗПОДІЛ ГАЗУ ПРИНЦИПАМ СТИМУЛЮВАННЯ

2020 ◽  
pp. 24-28
Author(s):  
Столяр О. О.
Keyword(s):  
Natural Gas ◽  
Current Model ◽  
Incentive Regulation ◽  
Gas Distribution ◽  
Advantages And Disadvantages ◽  
The World ◽  
Selection Of

The purpose of this study is to determine the conformity (verification) of the current model of tariff formation for gas distribution service of gas companies to the principle of incentive regulation based on the selection of model elements and their comparison with the world successful experience. The method of verification based on the selection of model elements, the determination of the advantages and disadvantages of such a model, and the comparison of the latter, introduced at domestic gas companies on natural gas distribution, with the world's successful experience in regulating this issue. It is presented that this model does not fully comply with the principles based on long-term incentive regulation, which show its effectiveness in the world, which will be continued in the following studies.

SERVICEABILITY OF NATURAL GAS DISTRIBUTION NETWORKS AFTER EARTHQUAKES

2013 ◽  
Vol 07 (02) ◽  
pp. 1350005 ◽  
Author(s):  
GIAN PAOLO CIMELLARO ◽  
ALESSANDRO DE STEFANO ◽  
OMAR VILLA
Keyword(s):  
Natural Gas ◽  
Distribution Network ◽  
Distribution Networks ◽  
Small Towns ◽  
Disaster Resilience ◽  
Gas Distribution ◽  
Gas Network ◽  
Resilience Index ◽  
Entire Network

The concept of disaster resilience has received considerable attention in recent years and it is increasingly used as an approach for understanding the dynamics of natural disaster systems. No models are available in literature to measure the performance of natural gas network, therefore, in this paper, a new performance index measuring functionality of gas distribution network have been proposed to evaluate the resilience index of the entire network. It can be used for any type of natural or manmade hazard which might lead to the disruption of the system. The gas distribution network of the municipalities of Introdacqua and Sulmona, two small towns in the center of Italy which were affected by 2009 earthquake have been used as case study. Together the pipeline network covers an area of 136 km2, with 3 M/R stations and 16 regulation groups. The software SynerGEE has been used to simulate different scenario events. The numerical results showed that, during emergency, to ensure an acceptable delivery service, it is crucial to guarantee the functionality of the medium pressure gas distribution network. Instead to improve resilience of the entire network the best retrofit strategy is to include emergency shutoff valves along the pipes.

scholarly journals An improvement of Hardy Cross method applied on looped spatial natural gas distribution networks

2017 ◽  
Author(s):  
Dejan Brkic
Keyword(s):  
Gas Flow ◽  
Solution Method ◽  
Distribution Networks ◽  
Original Method ◽  
Gas Distribution ◽  
Gas Network ◽  
Hardy Cross ◽  
Successive Substitution ◽  
Newton Raphson ◽  
Looped Network

Hardy Cross method is common for calculation of loops-like gas distribution networks with known node gas consumptions. This method is given in two forms: original Hardy Cross method-successive substitution methods and improved-simultaneous solution method (Newton-Raphson group of methods). Problem of gas flow in looped network is nonlinear problem; i.e. relation between flow and pressure drop is not linear while relation between electric current and voltage is. Improvement of original method is done by introduction of influence of adjacent contours in Yacobian matrix which is used in calculation and which is in original method strictly diagonal with all zeros in non-diagonal terms. In that way necessary number of iteration in calculations is decreased. If during the design of gas network with loops is anticipated that some of conduits are crossing each other without connection, this sort of network became, so there has to be introduced corrections of third or higher order.

Cost saving allocation of horizontal cooperation in restructured natural gas distribution network

Kybernetes ◽  
2018 ◽  
Vol 47 (6) ◽  
pp. 1217-1241 ◽  
Author(s):  
Jafar Razmi ◽  
Anis Hassani ◽  
Ashkan Hafezalkotob
Keyword(s):  
Natural Gas ◽  
Cooperative Game ◽  
Distribution Network ◽  
Cost Savings ◽  
Gas Distribution ◽  
Content Type ◽  
Horizontal Cooperation ◽  
Gas Market ◽  
Yazd City ◽  
The Cost

Purpose Over the past two decades, in developed countries a trend towards the liberalization and restructuring of the gas market has been observed. Today, restructuring is an ongoing process. In this study, a restructured natural gas market has been considered in which several regional distribution companies have ownership of the network and are competing against each other to gain more benefits. The main purpose of this study is to achieve efficiency and economic rationality in such a market through horizontal cooperation. Design/methodology/approach A restructured natural gas distribution network is modeled as a cooperative game to estimate the potential cost savings for various collaboration scenarios. In addition, the cost savings’ allocation among collaborating companies is evaluated using the cooperative game theory. Findings The results reveal validity and efficiency of the solution of the proposed model and capabilities of the cooperative game theory for reduction in gas distribution costs and improvement in the service level. Research limitations/implications This study is limited to natural gas in one region of Yazd City in Iran. Moreover, one segment of the natural gas network (i.e. distribution network) is modeled. Moreover, long-term cooperation between companies relies on fair distribution of cooperation benefits to the participants. Practical implications For the purpose of comparison and to get an insight into properties of the cost savings game, the real case study of one region of Yazd city in Iran is implemented. Originality/value This study contributes to the competitive models in the restructured gas market, particularly, in gas distribution network. The main contribution is to provide potential benefits for the participants via the horizontal cooperation.

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