scholarly journals Numerical Simulation of Natural Gas Pipeline Transients

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Abdoalmonaim S. M. Alghlam ◽  
Vladimir D. Stevanovic ◽  
Elmukhtar A. Elgazdori ◽  
Milos Banjac

Simulations of natural gas pipeline transients provide an insight into a pipeline capacity to deliver gas to consumers or to accumulate gas from source wells during various abnormal conditions and under variable consumption rates. This information is used for the control of gas pressure and for planning repairs in a timely manner. Therefore, a numerical model and a computer code have been developed for the simulation of natural gas transients in pipelines. The developed approach is validated by simulations of test cases from the open literature. Detailed analyses of both slow and fast gas flow transients are presented. Afterward, the code is applied to the simulation of transients in a long natural gas transmission pipeline. The simulated scenarios cover common operating conditions and abrupt disturbances. The simulations of the abnormal conditions show a significant accumulation capacity and inertia of the gas within the pipeline, which enables gas packing and consumers supply during the day time period. Since the numerical results are obtained under isothermal gas transient conditions, an analytical method for the evaluation of the difference between isothermal and nonisothermal predictions is derived. It is concluded that the nonisothermal transient effects can be neglected in engineering predictions of natural gas packing in long pipelines during several hours. The prescribed isothermal temperature should be a few degrees higher than the soil temperature due to the heat generation by friction on the pipelines wall and heat transfer from the gas to the surrounding soil.


Author(s):  
Jill Gilmour

A software package which optimizes natural gas pipeline operation for minimum fuel consumption is in use on a commercial transmission pipeline. This Optimization Program has resulted in pipeline fuel savings in daily pipeline operation. In addition, the effect of a new compressor/turbine unit on the pipeline system as a whole can be accurately and easily quantified through use of the Optimization Program before the unit is even installed. The results from one turbine replacement study showed the total system fuel consumption and operating hours predicted for each unit were not directly related to a high turbine efficiency. This paper describes the simulation techniques used for the gas turbine and compressor modeling. The methodology behind the system-wide optimization is also provided, along with a detailed discussion of the program application to gas turbine and compressor replacement studies.



2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Shaohua Dong ◽  
Yinuo Chen ◽  
Xuan Sun ◽  
Hang Zhang

As developments in natural gas pipelines increasingly incorporate higher grades of steel, larger diameters, and higher pressures, the consequences of an accident caused by leakage, explosion, or ignition become progressively more severe. Currently, major technical obstacles include the quantification of the impact of an explosion shock wave of a high-strength, large-diameter natural gas pipeline, and the selection of a reasonable shock wave overpressure model appropriate to the operating conditions. In this paper, six models of shock wave overpressure theories, namely, the TNT equivalent method, the TNO method, the multienergy method, the British Gas method, the Shell method, and the Lee formula, were compared and analyzed to determine their applicability. A shock wave model adapted to the characteristics of a full-scale test was proposed, and the model verification of a full-scale blasting test was conducted on pipelines with diameters of 1422 mm and 1219 mm, respectively. Subsequent results indicated that the modifications to the TNT equivalent and the test parameters correlated with changes in the suitability of the model. Henrych’s formula calculation model of the British Gas method was found to correspond strongly with the measured value, in which the absolute value of the relative error was less than 30% and the absolute error within the range of 78 m to 800 m was no more than 0.05 MPa. Thus, the Henrych formula was adopted as the primary model formula for the shock wave overpressure calculations in this study. To further correct the error of the model, the trend between the curve obtained by the Henrych formula and the fitting curve of the measured value was compared and analyzed. The positive and negative compensations of the shaded area before and after the intersection point were carried out, and the new error correction overpressure model formula was obtained by fitting, with the error controlled within 15%.



2018 ◽  
Vol 13 (3) ◽  
Author(s):  
Dr. Adarsh Kumar Arya ◽  
Dr. Shrihari Honwad

Abstract Transportation of natural gas from gathering station to consumption centers is done through complex gas pipeline network system. The huge cost involved in transporting natural gas has made pipeline optimization of increased interest in natural gas pipeline industries. In the present work a lesser known application of Ant Colony in pipeline optimization, has been implemented in a real gas pipeline network. The objective chosen is to minimize the fuel consumption in a gas pipeline network consisting of seven compressors. Pressures at forty-five nodes are chosen as the decision variables. Results of Ant Colony Optimization (ACO) have been compared with those of GAMS that utilizes ‘Generalized gradient principles’ for optimization. Our results utilizing ACO show significant improvement in fuel consumption reductions. Similar procedures can be adopted by researchers and pipeline managers to help pipeline operators in fixing up the pressures at different nodes so as the fuel consumption in compressors gets minimized.



Author(s):  
Sandeep Vyas

Reliance Gas Pipelines Limited (RGPL) is currently implementing a gas pipeline project from Shahdol, Madhya Pradesh to Phulpur, Uttar Pradesh for evacuation of gas produced from Coal Bed Methane (CBM) blocks owned by Reliance Industries Ltd. This pipeline will be hooked up with GAIL’s HVJ Pipeline at Phulpur. Over all Pipeline system includes 312 km (approx.) long trunk line, and associated facilities such as Compressor Station at Shahdol, Intermediate Pigging facilities, Metering & Regulating facilities at Phulpur and 12 No. Mainline valve stations. Gas produced from CBM blocks will be dehydrated within Gas Gathering Station facilities of CBM Project located upstream of pipeline Compressor station at Shahdol. Gas received at pipeline battery limit is dry and non-corrosive gas in nature, Internal corrosion is not expected in normal course of operation, however internal corrosion of the natural gas pipeline can occur when the pipe wall is exposed to moisture and other contaminants either under process upset conditions or under particular operating conditions. Even though internal corrosion is not expected during normal course of operations, to take care of any eventuality, it is proposed to implement Internal Corrosion Monitoring (ICMS) system in this project. ICMS will provide an efficient and reliable means of continuous monitoring internal corrosion. Internal Corrosion Monitoring (ICMS) system is used as a part of overall integrity management framework; to achieve two objectives viz., verify the corrosive behaviour of gas and to verify the efficacy of applied preventive actions. Philosophy involved in evaluating a suitable CM technique would include : • Applicable corrosion damage mechanisms, anticipated corrosion rates and probable locations. • Suitable CM technique and location based on process condition, system corrosivity, water content, pigging facilities, available corrosion allowance, design life, maintenance etc., • Measurement frequency. Some of the Corrosion Monitoring techniques used for pipeline and of relevance are: • Weight-loss Corrosion Coupons (CC), • Electrical Resistance probes (ER), • Linear Polarization Resistance Probe (LPR) • Ultrasonic Thickness Measurement (UT) • Sampling Points (SP) This paper discusses the merits / demerits of these corrosion monitoring techniques, considerations for selecting a specific technique for the Shahdol – Phulpur Gas Pipeline Project and highlights the implementation of the internal corrosion monitoring system.



2012 ◽  
Vol 268-270 ◽  
pp. 1244-1248
Author(s):  
Shan Bi Peng ◽  
En Bin Liu ◽  
Xiao Chun Du ◽  
Rong Lin Hong

With the growth of the natural gas market, the long distance natural gas pipeline system is getting more and more important in nowadays. As a united and enclosed hydraulic system, the operation conditions of the whole line will be changed by the influence of the condition change in one station. On the one hand, the condition change made people analyze operation scheme more difficult, on the other hand, pipeline system operating conditions directly affect the relationship between the production and the sales of natural gas. Therefore, the operation of the gas pipeline must be optimized, which brings huge economic and social benefits. This paper constructed a simulation model of a long distance natural gas pipeline by TG.net, and then analyzed the change of the operating condition of the pipeline after a compressor station shut down, found out the regularity.



CivilEng ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 87-119
Author(s):  
Sk Kafi Ahmed ◽  
Dr. Golam Kabir

The main aim of this study is to identify the most important natural gas pipeline failure causes and interrelation analysis. In this research, the rough analytic hierarchy process (Rough-AHP) is used to identify the natural gas pipeline failure causes rank order. Then a combination of rough decision-making trial and evaluation laboratory (DEMATEL) and interpretive structural modeling (ISM) method is applied to generate the level of importance. The comparison of traditional DEMATEL and Rough-DEMATEL are also performed to establish the cause-effect interrelation diagram. Finally, the Bayesian Belief Network (BBN) is combined with Rough DEMATEL and ISM to identify the interrelation analysis among the most crucial failure causes. As a result, the energy supply company and government policymaker can take necessary safety plan and improve the operation. The main outcome of this study is to improve the security management and reduce the potential failure risks.



2021 ◽  
Vol 353 ◽  
pp. 01001
Author(s):  
Yan Xu ◽  
Yinglai Liu ◽  
Zhenjun Feng ◽  
Xianghui Nie ◽  
Chao Zhang ◽  
...  

When the natural gas pipeline is welding in service, the fast flowing medium with pressure in the pipe will take away a lot of heat, and the preheating temperature is not easy to be guaranteed, so it is easy to appear hydrogen-induced crack. In this paper, the in-service welding preheating temperature field of natural gas pipeline under the limit condition of unreduced volume was studied, and the pre-welding preheating test was carried out by using the medium frequency heating method. It is found that the temperature below the heating belt increases gradually with the increase of the intermediate frequency heating power, and the fitting shows a quadratic polynomial gradient. There are differences in preheating temperatures on the same circumference. The highest temperature mostly appears in the direction of 3 point of the pipeline, while the lowest temperature mostly appears in the direction of 0 point, which is related to the tightness of the heating belt, sunshine, blowing and other factors. In addition, the preheating temperature field of the pipeline in service is related to the gas flow in the pipeline. At the same heating power, the downstream temperature of the heating belt is higher than the upstream temperature at the same location, and the closer to the heating belt, the higher the temperature is. When the gas flow rate reaches 9.37m/s and the heating power is 160kW, the average measured temperature at 50mm upstream and downstream of the heating belt of Φ1016 pipeline is 107℃, and the average measured temperature at 50mm upstream of the heating belt is 71℃. When the gas flow rate reaches 8.91m/s and the heating power is 200kW, the average measured temperature at the downstream 50mm of the heating belt of Φ1219 pipeline is 72℃, the average measured temperature at the upstream 50mm of the heating belt is 52℃and the average measured temperature at the upstream 30mm of the heating belt is 71℃..



Author(s):  
Augusto Garcia-Hernandez ◽  
Klaus Brun

Energy required to transport the fluid is an important parameter to be analyzed and minimized in pipeline applications. However, the pipeline system requirements and equipment could impose different constraints for operating pipelines in the best manner possible. One of the critical parameters that it is looked at closely, is the machines’ efficiency to avoid unfavorable operating conditions and to save energy costs. However, a compression-transport system includes more than one machine and more than one station working together at different conditions. Therefore, a detailed analysis of the entire compression system should be conducted to obtain a real power usage optimization. This paper presents a case study that is focused on analyzing natural gas transport system flow maximization while optimizing the usage of the available compression power. Various operating scenarios and machine spare philosophies are considered to identify the most suitable conditions for an optimum operation of the entire system. Modeling of pipeline networks has increased in the past decade due to the use of powerful computational tools that provide good quality representation of the real pipeline conditions. Therefore, a computational pipeline model was developed and used to simulate the gas transmission system. All the compressors’ performance maps and their driver data such as heat rate curves for the fuel consumption, site data, and running speed correction curves for the power were loaded in the model for each machine. The pipeline system covers 218 miles of hilly terrain with two looped pipelines of 38″ and 36″ in diameter. The entire system includes three compressor stations along its path with different configurations and equipment. For the optimization, various factors such as good efficiency over a wide range of operating conditions, maximum flexibility of configuration, fuel consumption and high power available were analyzed. The flow rate was maximized by using instantaneous maximum compression capacity at each station while maintaining fixed boundary conditions. This paper presents typical parameters that affect the energy usage in natural gas pipeline applications and discusses a case study that covers an entire pipeline. A modeling approach and basic considerations are presented as well as the results obtained for the optimization.



Author(s):  
Augusto Garcia-Hernandez ◽  
Klaus Brun

Energy required to transport the fluid is an important parameter to be analyzed and minimized in pipeline applications. However, the pipeline system requirements and equipment could impose different constraints for operating pipelines in the best manner possible. One of the critical parameters that is looked at closely, is the machines’ efficiency to avoid unfavorable operating conditions and to save energy costs. However, a compression-transport system includes more than one machine and more than one station working together at different conditions. Therefore, a detailed analysis of the entire compression system should be conducted to obtain a real power usage optimization. This paper presents a case study that is focused on analyzing natural gas transport system flow maximization while optimizing the usage of the available compression power. Various operating scenarios and machine spare philosophies are considered to identify the most suitable conditions for an optimum operation of the entire system. Modeling of pipeline networks has increased in the past decade due to the use of powerful computational tools that provide good quality representation of the real pipeline conditions. Therefore, a computational pipeline model was developed and used to simulate the gas transmission system. All the compressors’ performance maps and their driver data such as heat rate curves for the fuel consumption, site data, and running speed correction curves for the power were loaded in the model for each machine. The pipeline system covers 218 miles of hilly terrain with two looped pipelines of 38″ and 36″ in diameter. The entire system includes three compressor stations along its path with different configurations and equipment. For the optimization, various factors such as good efficiency over a wide range of operating conditions, maximum flexibility of configuration, fuel consumption and high power available were analyzed. The flow rate was maximized by using instantaneous maximum compression capacity at each station while maintaining fixed boundary conditions. This paper presents typical parameters that affect the energy usage in natural gas pipeline applications and discusses a case study that covers an entire pipeline. A modeling approach and basic considerations are presented as well as the results obtained for the optimization.



Author(s):  
Francis Bainier ◽  
Rainer Kurz ◽  
Philippe Bass

Abstract Gas Transmission System Operators (TSO1) are considering injecting hydrogen gas into their networks. Blending hydrogen into the existing natural gas pipeline network appears to be a strategy for storing and delivering renewable energy to markets [1], [2], [3]. In the paper GT2019-90348 [4], the authors have explored the efficiency of H2-blending in a natural gas pipeline network. The conclusion of the paper is: the energy transmission capacity and the efficiency decrease with the introduction of H2, nevertheless, the authors conclude that it is not an obstacle, but the way of using transmission natural gas networks should be closely studied to find an economic optimum, based both on capital and operating expenses. To establish the comparison, the paper did not take into account the limits of the equipment; all equipment was considered as compatible with any load of hydrogen blending. In the current paper, the idea is to consider the hypothesis that the only factor which has impact on the infrastructure is the partial pressure of H2. The idea is not new, in 1802, Dalton published a law called Dalton’s Law of Partial Pressures [5]. Dalton established empirically that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual component gases. The partial pressure is the pressure that each gas would exert when it alone occupied the volume of the mixture at the same temperature. Independent of the limits of the equipment, the authors explore the relationships between a network capacity and its associated pressures in regards to the H2 partial pressure. Within the partial pressure constraint, the goal is to find the maximum H2 flowrate. This flowrate is then compared with a flowrate which is a function of % H2. Nevertheless, steel is subjected to hydrogen invasion while being exposed to hydrogen containing environments during mechanical loading: resulting in hydrogen embrittlement (HE). HE also depends on the textured microstructure. In the final results [6] [7], the measured fatigue data reveals that the fatigue life of steel pipeline is degraded by the added hydrogen. The H2 has an effect on the steel fatigue which is not simply due to the partial pressure. The idea of the authors through the results of their 2 papers is to give the key points to help to find the optimum points for introducing H2 into a natural gas network, because, for them, the idea is that partial pressure is a factor in the equilibrium between H2 capacity and the remaining lifetime of the equipment. This paper shows the interest of the pressure management. With this management, it is possible to reach a constant H2 injection flow independently of the natural gas flow in the pipeline. In conclusion, to optimize the H2 capacity in their current network, a proposal to the TSOs is to adjust their dispatching methodology and their Pipeline Integrity Management (PIM) [8] [9].



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