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 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 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 Iterative Methods for Looped Network Pipeline Calculation

2017 ◽  
Author(s):  
Dejan Brkić
Keyword(s):  
Natural Gas ◽  
Iterative Methods ◽  
Flow Distribution ◽  
Convergence Properties ◽  
Two Fluids ◽  
Water Pipelines ◽  
Pipeline Networks ◽  
Hardy Cross ◽  
Simple Network ◽  
Looped Network

Since the value of the hydraulic resistance depends on flow rate, problem of flow distribution per pipes in a gas or water distributive looped pipelines has to be solved using iterative procedure. A number of iterative methods for determining of hydraulic solution of pipeline networks, such as, Hardy Cross, Modified Hardy Cross, Node-Loop method, Modified Node method and M.M. Andrijašev method are shown in this paper. Convergence properties are compared and discussed using a simple network with three loops. In a municipal gas pipeline, natural gas can be treated as incompressible fluid. Even under this circumstance, calculation of water pipelines cannot be literary copied and applied for calculation of gas pipelines. Some diferences in calculations of networks for distribution of these two fluids, i.e. water apropos natural gas are also noted.

scholarly journals Applications of Accurate Isentropic Exponent Determination for Fuel Gas Measurement

1995 ◽  
Author(s):  
David J. Pack ◽  
Terry J. Edwards ◽  
Derek Fawcett
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Precise Measurement ◽  
Gas Flows ◽  
Fuel Gas ◽  
Isentropic Exponent ◽  
Natural Gas Transmission ◽  
Gas Measurement ◽  
Cost Penalty

This paper discusses the determination and application of the isentropic exponent to the various thermodynamic processes found in a high pressure natural gas transmission system. Increasing demands for more precise measurement of natural gas, coupled with the need for greater efficiency and accountability of transportation and processing operations had led to our research and development efforts into the more precise measurement of gas flow, and the determination of gas thermodynamic properties including isentropic exponent. The isentropic exponent has many applications, some of which include: • the determination of the expansion factor ϵ, for calcuation of flow using an orifice or venturi type meter; • the volumetric efficiency in a reciprocating compressor; • the determination of the compression head for a centrigual compressor; • the engine power required for the set given conditions for gas compressor; • the calculation of discharge temperatures for compressors; and • the direct measurement of gas density. As can be appreciated, the application of an incorrect value for the isentropic exponent represents an error in the parameter determined. For large volume gas flows, this can translate into a significant cost penalty.

scholarly journals A Tight Linear Program for Feasibility Check and Solutions to Natural Gas Flow Equations

2019 ◽  
Vol 34 (3) ◽  
pp. 2441-2444 ◽  
Author(s):  
Tao Ding ◽  
Yiting Xu ◽  
Yongheng Yang ◽  
Zhenbang Li ◽  
Xiongwen Zhang ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Linear Program ◽  
Flow Equations ◽  
Natural Gas Flow

Determination of Pipe Roughness and Heat Transfer Coefficient in Pipeline Networks Using Multidomain Solution Method

1998 ◽  
Author(s):  
Jaroslaw Jelen ◽  
Hossein Golshan ◽  
Sandy Rizopoulos
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Parameter Identification ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Gas Flow ◽  
Solution Method ◽  
Accurate Determination ◽  
Pipeline System

In the development of new pipeline projects, all too often assumptions that are made in the initial stages of the business development opportunity are, for the most part, overly conservative. This inaccuracy is carried out through to the operation of the pipeline system and most assumptions do not change with subsequent expansions in the future until a conscious effort is made to determine and monitor those significant parameters that impact the pipeline’s overall performance. In highly complex systems such as NOVA Gas Transmission Ltd.’s (NGTL’s) pipeline network, with over 21400 Km of pipe segments of different sizes and ages, for an accurate determination of pressure drop while 12 BCF of gas, on average, is flowing through our network, we need a technique to precisely assess the values of friction factor and heat transfer coefficient. These values have a profound impact on the accuracy of the hydraulic simulations. The calculated values of pressure, flow rate, and temperature may be distorted by imprecise values of some parameters, such as friction factor or heat transfer coefficient. Thus, a proper estimation of these parameters is of great importance to the successful numerical flow simulation. Both friction factor and heat transfer coefficient are very difficult to measure; therefore, their values can only be assessed by solving an inverse problem (i.e. parameter identification process). Since the parameter estimation procedure reported in this paper requires multiple solution of inviscid gasdynamics differential equations, describing the gas flow through the pipeline system, a multidomain solution method has been applied to effectively solve the parameter identification 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.

Applications of Accurate Isentropic Exponent Determination for Fuel Gas Measurement

1996 ◽  
Vol 118 (3) ◽  
pp. 541-546
Author(s):  
D. J. Pack ◽  
T. J. Edwards ◽  
D. Fawcett
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Precise Measurement ◽  
Gas Flows ◽  
Fuel Gas ◽  
Isentropic Exponent ◽  
Natural Gas Transmission ◽  
Gas Measurement ◽  
Cost Penalty

This paper discusses the determination and application of the isentropic exponent to the various thermodynamic processes found in a high-pressure natural gas transmission system. Increasing demands for more precise measurement of natural gas, coupled with the need for greater efficiency and accountability of transportation and processing operations, had led to our research and development efforts into the more precise measurement of gas flow, and the determination of gas thermodynamic properties including isentropic exponent. The isentropic exponent has many applications, some of which include: • the determination of the expansion factor ε, for calculation of flow using an orifice or venturi-type meter; • the volumetric efficiency in a reciprocating compressor; • the determination of the compression head for a centrifugal compressor; • the engine power required for the given conditions for a gas compressor; • the calculation of discharge temperatures for compressors; and • the direct measurement of gas density. As can be appreciated, the application of an incorrect value for the isentropic exponent represents an error in the parameter determined. For large volume gas flows, this can translate into a significant cost penalty.

Sign in / Sign up

Export Citation Format

Share Document