scholarly journals Steady-state non-isothermal flow model for natural gas transmission in pipes

2016 ◽  
Vol 40 (23-24) ◽  
pp. 10020-10037 ◽  
Author(s):  
Alfredo López-Benito ◽  
Francisco J. Elorza Tenreiro ◽  
Luis C. Gutiérrez-Pérez
Author(s):  
D. S. Kalabukhov

Abstract Turboexpanders for gas industry are used for various purposes, for example, for generating electricity at gas distribution and compressor stations of the natural gas transmission system. Considering the initially high gas pressures, in many cases it is advisable to use a system of successively located turbine drives. This makes it possible to convert the energy of gas pressure into electrical energy to consumers of different capacities. To date, theoretical work on the optimization of regime and geometric parameters of such systems at initial stages of design is absent. In this paper, parametric studies were conducted on the effect of initial project data on the energy efficiency of a system of two turbo-generators with a power of up to 50 kW. As initial data, the thermodynamic parameters at the input and output from the turbine drive system and the operating parameters of the turbine drives are considered. To carry out the research, a mathematical flow model in the system of series connected axial small-sized turbines is implemented in the Matlab software package. Rational ranges of thermodynamic and regime relationships are found, which allows to significantly increase the design efficiency of a system of axial small-sized turbogenerators in comparison with the case of its design without taking into account the received information.


2020 ◽  
Vol 32 (3) ◽  
pp. 697-713
Author(s):  
Shixuan Zhang ◽  
Sheng Liu ◽  
Tianhu Deng ◽  
Zuo-Jun Max Shen

We study the energy consumption minimization problems of natural gas transmission in gunbarrel structured networks. In particular, we consider the transient-state dynamics of natural gas and the compressor’s nonlinear working domain and min-up-and-down constraints. We formulate the problem as a two-level dynamic program (DP), where the upper-level DP problem models each compressor station as a decision stage and each station’s optimization problem is further formulated as a lower-level DP by setting each time period as a stage. The upper-level DP faces the curse of high dimensionality. We propose an approximate dynamic programming (ADP) approach for the upper-level DP using appropriate basis functions and an exact approach for the lower-level DP by exploiting the structure of the problem. We validate the superior performance of the proposed ADP approach on both synthetic and real networks compared with the benchmark simulated annealing (SA) heuristic and the commonly used myopic policy and steady-state policy. On the synthetic networks (SNs), the ADP reduces the energy consumption by 5.8%–6.7% from the SA and 12% from the myopic policy. On the test gunbarrel network with 21 compressor stations and 28 pipes calibrated from China National Petroleum Corporation, the ADP saves 4.8%–5.1% (with an average of 5.0%) energy consumption compared with the SA and the currently deployed steady-state policy, which translates to cost savings of millions of dollars a year. Moreover, the proposed ADP algorithm requires 18.4%–61.0% less computation time than the SA. The advantages in both solution quality and computation time strongly support the proposed ADP algorithm in practice.


2011 ◽  
Vol 121-126 ◽  
pp. 2426-2430
Author(s):  
Yun You ◽  
Lin Li ◽  
Long Zhu Gao

Based on the network node model and with the help of MATLAB program, we calculated normal and accident hydraulic conditions in urban natural gas transmission and distribution network. In particular, we analyzed and discussed the corresponding measures under accident conditions. It can provide the basis for remote controlling, pressure regulating and steady-state analysis in transmission and distribution network.


Author(s):  
Paul Cousens ◽  
Chas Jandu

As part of an important project to reinforce the natural gas transmission network, a new pipeline has been constructed to transport natural gas from a major UK LNG storage facility into the national transmission system. The project involved the installation of several sections by trenchless methods, namely auger boring for a number of road crossings and significant lengths of horizontal directional drilling (HDD) beneath railroads, canals and marshland. The installation of pipelines using trenchless techniques such as HDD continues to increase in popularity. The various methods available offer advantages over traditional open cut techniques, in particular much reduced disruption during the construction of road and rail crossings. Furthermore, increased awareness and responsibility towards the environment leads us to seek installation methods that cause the least disruption at the surface and have the least impact to the environment. It was required to assess the proposed crossing designs against acceptable stress limits set out in company specifications and against the requirements of UK design code IGE/TD/1 Edition 4 [1], which requires that ‘additional loads’ such as soil loadings, thermal loads, settlement and traffic loading are accounted for within the stress calculations. However, it does not stipulate the sources of such equations and the pipeline engineer must rely on other methods and published sources of information. This paper presents the method used to analyse those sections of the new pipeline installed by auger boring and HDD focusing on the methods and formulae used to calculate the stresses in the pipeline from all loading sources.


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