Transient Modeling of Surge Pressures Within Injection Terminal Facilities

2014 ◽  
Author(s):  
Emma Perez ◽  
Leanne Thomson
Keyword(s):  
Computational Models ◽  
Fluid Velocity ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Modeling Tools ◽  
Worst Case ◽  
Petroleum Systems ◽  
Piping Systems ◽  
Abnormal Operating Conditions ◽  
Oil Injection

Pressure transients in piping systems occur whenever there is a change in fluid velocity. If this change is large enough, the pressure wave produced can exceed the Maximum Operating Pressure (MOP) of the system. Canadian and US regulations allow liquid petroleum systems to exceed the MOP under abnormal operating conditions however these surges cannot exceed 110% of MOP even for short periods of time. As part of meeting these regulations, the authors have applied complex computational modeling tools, developed methodologies, and company standards to identify sources of pressure surges, with the ultimate purpose of providing protection solutions useful for mitigating overpressures in oil injection facilities with low rated piping. These computational models and identification methodologies are based on a) abnormal operating conditions recorded in the past, b) potential worst case scenarios of terminal transients, and c) are particularly sensitive to input data such as piping characteristics, fluid types, and the initial states of the operating system. Our paper discusses the above mentioned transient simulation methodologies and their importance in meeting regulations.

A Rational Methodology for Detailed Pipeline Transient Hydraulic Analysis

2012 ◽  
Author(s):  
Gabriela Rodriguez ◽  
Bogdan Pavel
Keyword(s):  
Fluid Velocity ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Hydraulic Analysis ◽  
Initial State ◽  
Worst Case ◽  
Oil Pipeline ◽  
Control Centre ◽  
Standards And Regulations ◽  
Abnormal Operating Conditions

Pressure waves in pipelines develop any time there is a change in fluid velocity. If the change in velocity is large enough, the magnitude of a travelling pressure wave can exceed the Maximum Operating Pressure (MOP) of the piping. It is a violation of the Canadian and US regulations for petroleum pipelines (Canada – CSA Z662 4.18 and United States – ASME B31.4) to operate a pipeline at pressures in excess of 110% MOP even for short periods of time. In order to meet standards and regulations, transient analyses are undertaken to verify whether the pipeline MOP profile is susceptible to overpressures and to recommend solutions for such cases. This paper presents the results of a working group on developing a standard for the suite of transient scenarios and methodology to be used for detailed transient hydraulic analysis. The work consisted of reviewing and analyzing historical transient studies and, abnormal operating conditions / overpressure events recorded by Control Centre; as well as, incorporating new learning from operational lines. Methodology standardization focused on four areas: selection of inputs, model scope and criticality of pipeline sections, pipeline initial state, and worst-case upset scenarios. As a result, this paper describes the most prudent approach for each area or step of a pipeline transient analysis; including the evaluation of mitigation options if required. Finally, the use of this methodology is illustrated on a crude oil pipeline.

Morphological Adaptation for Speed Control of Pipeline Inspection Gauges MC-PIG

2021 ◽  
Author(s):  
Sujet Phodapol ◽  
Tachadol Suthisomboon ◽  
Pong Kosanunt ◽  
Ravipas Vongasemjit ◽  
Petch Janbanjong ◽  
...  
Keyword(s):  
Fluid Velocity ◽  
Operating Conditions ◽  
Pi Control ◽  
Operating Pressure ◽  
Acceptable Error ◽  
Valve Unit ◽  
Pipeline Inspection ◽  
Flow Adjustment ◽  
Valve Angle ◽  
Moving Speed

Abstract Passive and active hybrid pipeline inspection gauges (PIGs) have been used for in-pipe inspection. While a passive PIG cannot control its speed, the hybrid version can achieve this by using an integrated valve specifically designed and embedded in the PIG. This study proposes a generic new method for speed adaptation in PIGs (called MC-PIG) by introducing a generic, modular, controllable, external valve unit add-on for attaching to existing conventional (passive) PIGs with minimal change. The MC-PIG method is based on the principle of morphological computation with closed-loop control. It is achieved by regulating/computing the PIG's morphology (i.e., a modular rotary valve unit add-on) to control bypass flow. Adjustment of the valve angle can affect the flow rate passing through the PIG, resulting in speed regulation ability. We use numerical simulation with computational fluid dynamics (CFD) to investigate and analyze the speed of a simulated PIG with the valve unit adjusted by proportional-integral (PI) control under various in-pipe pressure conditions. Our simulation experiments are performed under different operating conditions in three pipe sizes (16″, 18″, and 22″ in diameter) to manifest the speed adaptation of the PIG with the modular valve unit add-on and PI control. Our results show that the PIG can effectively perform real-time adaptation (i.e., adjusting its valve angle) to maintain the desired speed. The valve design can be adjusted from 5 degrees (closed valve, resulting in high moving speed) to a maximum of 45 degrees (fully open valve, resulting in low moving speed). The speed of the PIG can be regulated from 0.59 m/s to 3.88 m/s in a 16″ pipe at 4.38 m/s (in-pipe fluid velocity), 2500 kPa (operating pressure), and 62 °C (operating temperature). Finally, the MC-PIG method is validated using a 3D-printed prototype in a 6″ pipe. Through the investigation, we observed that two factors influence speed adaptation; the pressure drop coefficient and friction of the PIG and pipeline. In conclusion, the results from the simulation and prototype show close characteristics with an acceptable error.

scholarly journals NUMERICAL STUDY ON THE INHIBITION OF CAVITATION IN PIPING SYSTEMS

2012 ◽  
Vol 19 ◽  
pp. 374-380
Author(s):  
SUN SEOK BYEON ◽  
SANG JUN LEE ◽  
YOUN-JEA KIM
Keyword(s):  
Vapor Pressure ◽  
Volume Fraction ◽  
Numerical Study ◽  
Fluid Velocity ◽  
Working Fluid ◽  
Operating Pressure ◽  
Butterfly Valve ◽  
Saturation Vapor Pressure ◽  
Piping Systems ◽  
Saturation Vapor

Abrupt closing valve in piping systems is sometimes resulted in cavitation due to the occurrence of high pressure difference. The bubbles generating by cavitation influence operating pressure and then those generate shock wave and vibration. These phenomena can consequentially cause to corrosion and erosion. So, the cavitation is the important factor to consider reliability of piping systems and mechanical lifetime. This paper investigated the various inhibition methods of cavitation in piping systems in which butterfly valves are installed. To prevent cavitation occurrence, it is desirable to analyze its characteristics between the upstream and downstream of process valve. Results show that the fluid velocity is fast when a working fluid passed through butterfly valve. The pressure of these areas was not only under saturation vapor pressure of water, but also cavitation was continuously occurred. We confirmed that the effect of existence of inserted orifice and influence to break condition under saturation vapor pressure of water. Results were graphically depicted by pressure distribution, velocity distribution, and vapor volume fraction.

Computer modeling as tools to estimate the impact of fuel type on the capacity rating of lime kilns

TAPPI Journal ◽  
2015 ◽  
Vol 14 (7) ◽  
pp. 461-473
Author(s):  
J. PETER GOROG ◽  
W. RAY LEARY ◽  
DAVID WANG ◽  
KEVIN DAVIS
Keyword(s):  
Natural Gas ◽  
Paper Industry ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Fuel Type ◽  
Case Scenario ◽  
Modeling Tools ◽  
Worst Case ◽  
The Impact ◽  
Capacity Rating

In response to the drop in the price of natural gas, the U.S. pulp and paper industry has switched from using fuel oil to natural gas to fire kilns used to regenerate lime in the kraft process. While being financially attractive, replacing fuel oil with natural gas can be challenging. This is particularity true when the capacity rating is constrained by the temperatures of the gas exiting the kiln. In the worst case scenario, the increase in flue gas temperatures associated with switching from fuel oil to natural gas can significantly de-rate the capacity of the kiln. This paper describes a range of computational modeling tools that can be used to estimate the impacts of kiln geometry, fuel type, operating conditions, and burner design on kiln performance. Data taken from operating kilns is presented, which validates the use of these models. A detailed case study is presented showing how small amounts of torrefied wood can be co-fired with natural gas as a replacement for fuel oil without de-rating the capacity of the kiln. The visualization of the flow fields, temperature distributions, and species concentrations provided by computer models are critical to optimizing kiln operations as new fuels are being considered as replacements for more expensive, carbon intensive fuel oil.

The onset of transverse recirculations during flow of gases in horizontal ducts with differentially heated lower walls

1994 ◽  
Vol 277 ◽  
pp. 249-269 ◽  
Author(s):  
N. K. Ingle ◽  
T. J. Mountziaris
Keyword(s):  
Heat Transfer ◽  
Computational Study ◽  
Chemical Vapour ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Case Scenario ◽  
Worst Case ◽  
Layer Structures ◽  
Fluid Properties ◽  
Inlet Conditions

A computational study has been performed to identify the onset of transverse buoyancy-driven recirculations during laminar flow of hydrogen and nitrogen in horizontal ducts with cool upper walls, and lower walls consisting of three sections: a cool upstream section, a heated middle section and a cool downstream section. The motivation for this work stems from the need to identify operating conditions maximizing the thickness uniformity, the interface abruptness and the precursor utilization during growth of thin films and multi-layer structures of semiconductors by metalorganic chemical vapour deposition (MOCVD). A mathematical model describing the flow and heat transfer along the vertical midplane of MOCVD reactors with the above geometry has been developed and computer simulations were performed for a variety of operating conditions using the Galerkin finite-element method. At atmospheric pressure and low inlet velocities, transverse recirculations form near the upstream and downstream edges of the heated section. These can be suppressed either by increasing the inlet velocity of the gas, so that forced convection dominates natural convection, or by decreasing the operating pressure to reduce the effects of buoyancy. The onset of transverse recirculations has been determined for Grashof (Gr) and Reynolds (Re) numbers covering the following ranges: 10−3 < Re < 100 and 1 < Gr < 106, with Gr and Re computed using fluid properties at the inlet conditions. The computations indicate that, for abrupt temperature changes along the lower wall (worst-case scenario), transverse recirculations are always absent if the following criteria are satisfied: \[(Gr/Re) < 100\quad {\rm for}\quad 10^{-3} < Re \leqslant 4\quad {\rm and}\quad (Gr/Re^2) < 25\quad {\rm for}\quad 4 \leqslant Re < 100.\]The predicted critical values of Re, which correspond to the onset of transverse recirculations, agree well with reported experimental observations. The above criteria can be used for optimal design and operation of horizontal MOCVD reactors and may also be useful for heat transfer studies in horizontal ducts with differentially heated lower walls.

Effect of operating conditions on rejection of anionic pollutants in the water environment by nanofiltration especially in very low pressure range

1996 ◽  
Vol 34 (9) ◽  
pp. 149-156 ◽  
Author(s):  
C. Ratanatamskul ◽  
K. Yamamoto ◽  
T. Urase ◽  
S. Ohgaki
Keyword(s):  
Water Environment ◽  
Chloride Ions ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Operating Pressure ◽  
Nanofiltration Membranes ◽  
Single Solution ◽  
Crossflow Velocity ◽  
Membrane Type ◽  
New Generation

The recent development of new generation LPRO or nanofiltration membranes have received attraction for application in the field of wastewater and water treatment through an increasingly stringent regulation for drinking purpose and water reclamation. In this research, the application on treatment of anionic pollutants (nitrate, nitrite, phosphate, sulfate and chloride ions) have been investigated as functions of transmembrane pressure, crossflow velocity and temperature under very much lower pressure operation range (0.49 to 0.03 MPa) than any other previous research used to do. Negative rejection was also observed under very much low range of operating pressure in the case of membrane type NTR-7250. Moreover, the extended Nernst-Planck model was used for analysis of the experimental data of the rejection of nitrate, nitrite and chloride ions in single solution by considering effective charged density of the membranes.

Efficient Analysis of a Catenary Riser

2006 ◽  
Author(s):  
Elizabeth Passano ◽  
Carl M. Larsen
Keyword(s):  
Operating Conditions ◽  
Stochastic Simulations ◽  
Worst Case ◽  
Nonlinear Structure ◽  
Tension Response ◽  
Extreme Response ◽  
Analysis Strategies ◽  
Low Tension ◽  
Term Response

The paper deals with the challenge of predicting the extreme response of catenary risers, a topic of both industry and academic interest. Large heave motions introduced at the upper end of a catenary riser can lead to compression and large bending moments in the region immediately above the touch down area. In the worst case, dynamic beam buckling may occur. The focus of the paper will be on understanding the riser behaviour in extreme, low-tension response and in establishing suitable analysis strategies to predict the extreme response. Results from long nonlinear stochastic simulations of many sea states with varying environmental and operating conditions may be combined to describe the long-term response of a nonlinear structure such as a catenary riser. However, this theoretically straight-forward approach is very demanding computationally and ways to limit the extent of nonlinear stochastic simulations are therefore sought. The usefulness of simpler methods such as regular wave analysis to improve understanding of the physical behaviour and to aid in concentrating the nonlinear simulations to where they are most useful, will be demonstrated.

Compressible Flowfield Characteristics of Butterfly Valves

1989 ◽  
Vol 111 (4) ◽  
pp. 400-407 ◽  
Author(s):  
M. J. Morris ◽  
J. C. Dutton
Keyword(s):  
Flow Separation ◽  
Pressure Ratio ◽  
Disk Surface ◽  
Surface Flow ◽  
Operating Conditions ◽  
Local Geometry ◽  
Operating Pressure ◽  
Butterfly Valve ◽  
Pressure Distributions ◽  
Flow Separation And Reattachment

The results of an experimental investigation into the flowfield characteristics of butterfly valves under compressible flow operating conditions are reported. The experimental results include Schlieren and surface flow visualizations and flowfield static pressure distributions. Two valve disk shapes have been studied in a planar, two-dimensional test section: a generic biconvex circular arc profile and the midplane cross-section of a prototype butterfly valve. The valve disk angle and operating pressure ratio have also been varied in these experiments. The results demonstrate that under certain conditions of operation the butterfly valve flowfield can be extremely complex with oblique shock waves, expansion fans, and regions of flow separation and reattachment. In addition, the sensitivity of the valve disk surface pressure distributions to the local geometry near the leading and trailing edges and the relation of the aerodynamic torque to flow separation and reattachment on the disk are shown.

Designing CO2 Transmission Pipelines Without Crack Arrestors

2010 ◽  
Author(s):  
Graeme G. King ◽  
Satish Kumar
Keyword(s):  
Wall Thickness ◽  
Carbon Capture ◽  
Power Plants ◽  
Oil And Gas ◽  
Cost Optimization ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Design Work ◽  
Industrial Facilities ◽  
Pipeline Network

Masdar is developing several carbon capture projects from power plants, smelters, steel works, industrial facilities and oil and gas processing plants in Abu Dhabi in a phased series of projects. Captured CO2 will be transported in a new national CO2 pipeline network with a nominal capacity of 20×106 T/y to oil reservoirs where it will be injected for reservoir management and sequestration. Design of the pipeline network considered three primary factors in the selection of wall thickness and toughness, (a) steady and transient operating conditions, (b) prevention of longitudinal ductile fractures and (c) optimization of total project owning and operating costs. The paper explains how the three factors affect wall thickness and toughness. It sets out code requirements that must be satisfied when choosing wall thickness and gives details of how to calculate toughness to prevent propagation of long ductile fracture in CO2 pipelines. It then uses cost optimization to resolve contention between the different requirements and arrive at a safe and economical pipeline design. The design work selected a design pressure of 24.5 MPa, well above the critical point for CO2 and much higher than is normally seen in conventional oil and gas pipelines. Despite its high operating pressure, the proposed network will be one of the safest pipeline systems in the world today.

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