bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress Analysis of a Gas Pipeline Installed Using HDD and Auger Bore Techniques
Authors: Cousens Paul , Jandu Chas
Published: July 2009

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.
Alarm Management for Pipelines
Authors: McTavish Mark K.
Published: July 2009

In 2005 the National Transportation Safety Board, concluded that an effective alarm review/audit system will increase the likelihood of controllers appropriately responding to alarms associated with pipeline leaks. This paper looks at the pipeline industry in the broader context of process industry alarm management and how the best practices of the process industry apply to the pipeline industry.
Sizing Stress Corrosion Cracking Using Laser Ultrasonics
Authors: Klein Marvin , Portzgen Niels , Tomar Munendra S. , Fingerhut Martin , Ansari Homayoon
Published: July 2009

Managing Stress Corrosion Cracking (SCC) damaged pipe has been a formidable challenge to the pipeline industry. Development of a practical solution for measurement and evaluation of SCC has been marred by the complexity of crack shapes, their distribution within a crack colony, and the lack of non-destructive technology capable of reliably measuring the crack depths. Laser Ultrasonics is an inspection technology wherein lasers are used for generation and detection of ultrasonic waves in the pipeline steel to be inspected. Unlike conventional ultrasonic testing, Laser Ultrasonics has a large frequency bandwidth and a tiny (∼0.5mm) footprint. These characteristics make it ideally suited for application as a depth sizing tool for closely-spaced cracks in a colony. It has been conclusively proved that laser ultrasonic inspection using the time of flight diffraction (TOFD) technique can reliably and accurately measure the depth of naturally occurring SCC and potentially other cracks and seam weld anomalies. This presentation describes the results of this co-sponsored project, including recent full scale demonstrations where a laser ultrasonic measurement subsystem has been built onto a prototype scanner.
Further Large-Scale Implementation of Advanced Pipeline Technologies
Authors: Zhou Joe , Taylor David , Hodgkinson David
Published: July 2009

TransCanada PipeLines Limited (TransCanada) has continued its leading effort in developing and implementing pipeline technologies. With a well structured and large-scale technology implementation program and collaboration of many partners over a period of three years, TransCanada has successfully implemented a number of technologies in a 38 km long NPS 42 pipeline construction project. The technology implementation program included installation of 7.3 km Grade 690 (X100) pipe supplied by two manufacturers, deployment of tandem welding system, field trial of a phased array automated ultrasonic testing (AUT) system, the application of high performance composite coating (HPCC) and Alternative Integrity Validation (AIV) process that led to first ever construction hydrostatic test waiver from National Energy Board. The paper provides an overview of the technology implementation program and the experience gained in applying a wide range of advanced pipeline technologies.
Pig-Mounted Experimental Measurement of In-Situ Absolute Biaxial Stress in Pipelines
Authors: Allan Gordon , Russell David A. , Buttle David J. , Baker Greg , McCarthy John C.
Published: July 2009

This paper describes recent experimental work on the measurement of absolute levels of biaxial stress in ferromagnetic pipeline materials. A prototype in-line inspection tool has been constructed and has subsequently undergone evaluation in a series of pigging trials to determine its accuracy in recording of stress values. Recently attention has been raised by a number of groups working on the development of techniques intended to utilize the dependence of the magnetic response of ferrous materials to applied stress in order to directly measure stress. Most of these techniques have been based on the Barkhausen effect. This paper discusses the use of an alternative technique based on other magnetic properties that have been shown to allow derivation of a quantifiable relation between the level of stress present in material and the magnetic response. This technique, named MAPS by its developers, MAPS Technology, has been employed with considerable success out-with the pipeline industry. An earlier paper described the technique used to make the measurements. The response of pipe-wall materials to an applied alternating magnetic field is measured, and knowledge of the variation of magnetic properties of the material used to determine stress values. In order to prove the suitability of this technique to pipeline applications, a prototype inspection pig has been designed and constructed, and a series of tests performed in a 24″ test facility, constructed specifically for the purpose. The test facility design allowed for two modes of operation. The first of these allowed pigging through the 50m of test pipe, with an arrangement that allowed bending stresses to be applied to the pipe. The second mode of operation enabled internal pressure to be applied as the tool was pulled through the test section. The pig based system successfully gathered stress measurements in both axial and hoop directions. The pig measurements were subsequently compared to theoretical values of stress and to measurements taken with strain gauges and other instrumentation fitted to the test facility.
Elements of an Engineering-Based Integrity Management Program
Authors: Scrivner Ron , Alexander Chris
Published: July 2009

Establishing pipeline integrity requires an understanding of the specific threats, their relationship to the overall condition of the pipeline, and the mitigating measures required to assure safe operation. In the past, the pipeline industry relied on years of research and experience to develop a set of tools to analyze these threats and apply conservative solutions to ensure pipeline integrity. With the implementation of the Integrity Management Program (IMP) in 2004 by the Pipeline and Hazardous Material Safety Administration (PHMSA), pipeline integrity must be addressed by operators where the analysis methods and results must be documented and defendable. This paper presents a detailed discussion of how existing knowledge, advances in analytical techniques, experimental methods, and engineering rigor are combined to develop field-friendly tools to characterize and ensure pipeline integrity. Two case studies are included, the first, to demonstrate how the proposed method was used to assess the integrity of a corroded elbow, the second, provides the reader with an example of how to develop a tool for evaluating the severity of dents in pipelines using available public-domain research. It is the hope of the authors that the approach presented in this paper will foster further developments and advanced pipeline integrity management.
Mass Production and Installation of X100 Linepipe for Strain-Based Design Application
Authors: Ishikawa Nobuyuki , Okatsu Mitsuhiro , Endo Shigeru , Kondo Joe , Zhou Joe , Taylor David
Published: July 2009

Continuous efforts have been made for the realization of strain-based design pipeline using high grade linepipe materials. Two demonstrative constructions of the pipelines using X100 linepipe proved sufficient materials properties for strain-based design and high quality field welding with good productivity. In order to verify further applicability of high strain X100 linepipe for long distance transmission, large scale installation of X100 pipeline was accomplished. Mass production of X100 linepipe of about 2,000 metric tons with the size of 42″OD and 14.3mm wall thick was successfully conducted by applying recent developed TMCP process including accelerated cooling and online heat treatment process and UOE pipe forming. Field girth welding was safely completed by the dual tandem pulsed GMAW, and sufficient girth weld properties were demonstrated. This paper will describe material development and mass production results of X100 linepipe for strain-based design which specifying longitudinal tensile properties such as Y/T ratio and uniform elongation. In order to securely specify the shape of stress-strain curve without Luders elongation, material parameter “stress ratio” was introduced for the material specification for compressive strain capacity. Stringent base metal requirements were imposed for base metal material properties in this project. One of the most challenging aspects in developing high strain linepipe is to balance uniform elongation and Charpy absorbed energy. Dual phase microstructure is essential to improve strain capacity, but this may lead to lower Charpy absorbed energy. Therefore, precise control of microstructure by controlling plate manufacturing parameter was required. In addition, on-line heating process subsequently after accelerated cooling enabled increase of Charpy energy without deteriorating uniform elongation. Girth weld properties were closely evaluated using the X100 pipe in as UOE condition and after external coating. All the material properties of base metal and girth weldment of the X100 linepipes used for this project fulfill the stringent requirement for strain-based design consideration to prevent buckling and weld fracture.
Engineering and Ultrasonic Tool Run in a Natural Gas Pipeline to Detect SCC
Authors: Steinhubl Shani M. , Mann Derrick R.
Published: July 2009

Stress Corrosion Cracking (SCC) is a major integrity threat for many gas and oil pipeline operators. Once SCC is detected on a pipeline, if the severity of the SCC is determined to be class III or IV, it is the operator’s responsibility to ensure that the risk of a SCC failure is adequately mitigated. This paper discusses several design strategies implemented by TransGas for the purpose of this UT ILI run including: designing a custom launcher to facilitate easy insertion of batching pigs, UT ILI tool, and batching liquid; development and use of a flow / speed control system utilizing pressure differential readings from orifice meters, as well as many of the logistical challenges associated with the project.
Analytical Approach to Determine Hydrotest Intervals
Authors: Sen Millan , Kariyawasam Shahani
Published: July 2009

Many gas pipeline operators use hydrotesting as a means of managing stress corrosion cracking in pipelines. Historically the interval at which the pipelines are hydrotested is largely empirical. If for instance a failure occurred on a pipeline section four years after a hydrotest, then four years would become the baseline interval. As failures are rare, these worst-case intervals are often applied across the system with little consideration to the many factors that would affect the relevant interval for different pipelines. This can result in an overly conservative frequency of hydrotests. In IPC 2006 an analytical method of determining hydrotest intervals, based on a time vs. pressure plot, was developed and published by Fessler et al. The study conducted herein examines this method, its assumptions, applicability, and limitations, with regards to an in-service pipeline system. It also discusses how this method was adapted to account for variable crack growth rates and failures. Application of this adapted method to the pipeline system and its results are discussed. It was found that this method could be used to predict hydrotest intervals for in-service pipelines. An additional method of using crack assessments with certain growth characteristics to develop hydrotest intervals is also presented. This method incorporated crack failure prediction calculations, and estimated crack growth rates, to predict hydrotest intervals. The results and the limitations are critically examined. Practical ways of improving the methods and ongoing work to improve the method are also explained.
The Benefits and Limitations of Using Risk Based Probabilistic and Deterministic Analysis for Monitoring and Mitigation Planning
Authors: Bott Steven , Sporns Ryan
Published: July 2009

The benefits and limitations of using both deterministic and probabilistic analysis are demonstrated using two case studies. The incorporation of High Consequence Area (HCA) data with deterministic and probabilistic analysis is an effective way to track the corrosion risk of a pipeline through time. Both types of analysis of high-resolution in line inspection corrosion data can be used to plan excavation and repair programs and set safe re-assessment intervals. Back to back high resolution corrosion inspections are presented to validate the use of these techniques along with a discussion on how to properly allocate resources to manage corrosion uncertainty.
Pipeline Construction Practices Risk Assessment Methodology
Authors: Lazor Robert
Published: July 2009

This paper examines how changes to pipeline construction specifications/practices can impact both technical and economic considerations of the overall project. The main topics of concern fall under the general headings of joining design, welding, and nondestructive examination (NDE). The different options for the project-specific construction specifications include a discussion of recommended construction practices, and includes an assessment of the risks associated with the different construction alternatives. The following six specific issues were considered significant to the risk of construction-related issues and these were the focus of this scope of work: • Assess the design requirements for joining pipe with different wall thickness, and specifically the use of counterbored and tapered transition pieces; • Examine the impact of specific welding-related construction activities such as release of internal line-up clamps used for welding; • Examine the need for hot pass deposition before removing the internal line-up clamp; • Examine the delay time between weld passes and the total time to complete each weld; • Investigate delay time before completion of weld NDE; • Consider the differences between the use of gamma and x-ray NDE, and the likelihood of detecting weld flaws. A semi-quantitative risk assessment methodology has been developed to calculate the likelihood of failure from planar defects in girth welds. The failure frequencies of girth welds have been based on industry experience, and combined with the likelihood of detection using nondestructive examination techniques, it is possible to show the likelihood of failure during either hydrostatic testing or subsequent service of the pipeline. The results of such an analysis can be used to evaluate the risks associated with changes to construction practices along the pipeline right-of-way.
A Risk Assessment Tool for Evaluating Geohazards and Fisheries Sensitivity at Pipeline Water Crossings
Authors: Rempel Laura L. , Porter Michael
Published: July 2009

The Fisheries Act legislates Fisheries & Oceans Canada (DFO) to regulate all development activities affecting fish-bearing waters to ensure no net loss in habitat productivity. To meet the increasing regulatory demands of oil and gas development, DFO is developing a Fisheries Risk Assessment Tool (FRAT). The current focus is along the Mackenzie River Valley, Northwest Territories. The FRAT is applied to proposed pipeline stream crossings and evaluates the risk to fisheries resources from geohazards causing sedimentation impacts. Ultimately, the FRAT may be applied across Canada to streamline DFO’s regulatory process for pipeline stream crossings. The FRAT consists of a Geophysical Database that characterizes physical attributes of the river valley and channel in the vicinity of a crossing, plus a Fisheries Database that characterizes the fisheries resources and habitat of the stream. Algorithms have been developed to quantitatively estimate sedimentation hazard likelihood and fisheries sensitivity, which are coupled in a qualitative risk matrix that assigns an overall risk rating to each stream crossing. The overall risk rating then designates the level of regulatory review and authorization process carried out by DFO under the Fisheries Act. Geohazard algorithms are being calibrated and tested using field data and stream crossing construction scenarios are being incorporated into the risk assessment tool. This paper describes the FRAT and its application in the Mackenzie Valley, and presents preliminary results from risk analysis of pipeline stream crossings.
Best Practices for Third Party Pipeline Damage Risk Management With Social and Environment Responsibility: Transpetro—Petrobras Transporte S.A.
Authors: Boszczowski Eduardo Bomfim , Aragonez de Vasconcellos Carlos Renato , da Cruz Kleber Vini´cius , Pereira Filho Ozias , Cartagena Sarah Marcela C.
Published: July 2009

The present paper describes the tasks developed along 550 kilometers of PETROBRAS TRANSPORTE South Region right-of-way where there are more than 1000 kilometers of onshore pipelines. This work was based on the company Integrity Management Program, with focus on risk reduction due to third party damage, promoting social accountability and environment preservation. On the Introduction there are presented pipeline failures stats in USA and Europe. It’s visible in the stats that third party damage is one of the most common pipeline failures responsibleness. In the next topics we list the mitigation methods based on the Integrity Management Program that involves risk analysis; inspection plans based on risk; plan check and program audits. On the Detailed Plan we present standards and normal requirement for pipeline integrity; the Company GIS — Geographic Information System — where you find the pipeline data with its position and depth from ground level; the action plan to correct anomalies found during inspections; and the awareness programs performed through the Communication System to answer the solicitations registered at TRANSPETRO Call Center. We also present the social and environment Responsibility Program that includes the Identification of the communities around our right-of-way, the social and environment classification and the projects development to guaranty the installation integrity that contribute to the communities quality life raise. The Communication Plan for the stakeholders is based on API 1162 – Public Awareness Programs for Pipeline Operators. This plan is accomplished by a team of different professionals such as communication and social service professionals and others. They visit Public Officials (City Hall, Civil Defense, Fire Department, Road Police and Public Services Providers), Excavators, land owners and communities with the objective to guide and publicize safe and co-responsible manners to pipeline installations. It’s remarkable the creation of especial projects in the communities along the right-of-way, such as Communitarian vegetable fields, mobile movie theaters and educational effort in high schools. We also present the results from the Integrity Program to prevent third party damage, the improvement promoted and the recommendations to make it better. At the end we present the costs involved in all actions to prevent third party damage by Brazil South Region Pipeline Operator.
Evaluation of Pipeline Stresses During Line Lowering
Authors: Sen Millan , Zhou Joe
Published: July 2009

The stresses induced to a pipe during line lowering are the maximum stresses that the pipeline will experience during its lifetime, in regions where there are no excessive environmental loads. During the installation of the TransCanada pipeline at Stittsville, Ontario, it was critical to limit the pipeline stresses that occurred during line lowering. This was required in order to fulfill the requirements of ECA-based flaw acceptance criteria applicable to mainline welding. However, the construction of the pipeline involved numerous challenges with regards to moving equipment during the pipeline installation, regions of deep cover requirements, and spatial restrictions on the right of way. These conditions introduced complicated loading scenarios, which made it difficult to ascertain the resulting stresses that the line lowering would apply to the pipeline. These stresses were evaluated herein using the finite element analysis program PIPLIN, with consideration of the actual in-situ installation conditions. Each loading condition was modeled individually, and the forces in the sidebooms were considered in addition to the pipeline stresses. It was determined that all the stresses in the pipeline during the line lowering were acceptable, so long as the specified boom locations remained within limits.
The Australian Approach to Pipeline Safety Management
Authors: Tuft Peter
Published: July 2009

The Australian approach to management of pipeline safety and risk differs from that used in most other parts of the world. There is a strong focus on identifying causes of failure and designing against them using a cause/control model of risk management, and little use of quantitative risk assessment. Oil and gas pipelines in Australia are designed, constructed and operated in accordance with AS 2885. Since a major revision in 1997 this has been a risk-based standard. While it does contain numerous design rules, their application is flexible and to some extent dependent on the outcomes of a mandatory safety management study. Key elements of the standard include separation of wall thickness selection from pressure design factor, mandatory protection against external interference, special requirements for high consequence areas, and a safety management study process including qualitative assessment of residual risks. The AS 2885 process has been shown to be workable and effective. It results in a design which is optimised for safety at every point along the pipeline while not incurring costs for features that do not reduce risk. The process is oriented principally to design of new pipelines but is equally applicable to management of older pipelines which are suffering degradation or subject to changed conditions such as urban encroachment.
Performing a Comprehensive Single Pass Multiple Pipeline Survey
Authors: McDonnell Shamus , Ukiwe Chijioke , McMinn Mark , Purcell Jennifer
Published: July 2009

This paper presents a discussion of the methodologies and technologies implemented to complete a comprehensive and efficient close interval (CI), depth of cover (DOC) and current attenuation surveys over a new NPS 36 fusion bond epoxy (FBE) coated pipeline influenced by telluric and high frequency AC interference. The DOC and current attenuation survey interval was set to be the same as the CI survey interval (5′) to facilitate detailed profile of the pipeline, and to identify any area where marginal cover or geometric anomalies may exist. By completing both surveys in one pass, there was assurance that the CI readings were taken over the target pipeline. The DOC survey was completed with a continuous data stream from an electromagnetic pipe locator utilizing omni-directional antenna coils. All survey readings were recorded with highly accurate real time GPS to allow time synchronization and geographic information system (GIS) implementation of the survey data. GPS synchronization of the stationary, mobile data loggers and rectifiers were verified with multiple daily waveform analysis. Rectifiers were fitted with SCADA communications and GPS RMUs for remote monitoring and operation. Telluric and high frequency interferences were compensated for through waveform logging at both stationary data log and the remote surveyor points. Optimal readings were determined through advanced statistical analysis of the survey data.
Results of Field Trials of Realsens™, An Airborne Natural Gas Leak Detection Technology
Authors: Banica Adrian , Miller Doug , Tolton Boyd T.
Published: July 2009

Detecting natural gas leaks from the worlds nearly 5 million kilometers of underground pipelines is a difficult and costly challenge. Existing technologies are limited to ground deployment and have a number of limitations such as slow response, false leak readings and high costs. Various remote sensing solutions have been proposed in the past and a few are currently being developed. This paper starts by describing the remote sensing concept and then will focus on a new technology developed by Synodon scientists. This airborne instrument is a passive Gas Filter Correlation Radiometer (GFCR) that is tuned to measure ethane in the 3.3 microns near-infrared band. The paper will then present the results of the first airborne field tests and conclude with a description of the service which Synodon will be offering to the transmission and distribution pipeline operators using the new technology.
Enhanced Pipeline Leak Detection Using Airborne Differential Absorption LIDAR
Authors: Brake Daniel E. , Stearns Steven V. , Ronsky N. Daryl
Published: July 2009

Aerial leak detection by use of Differential Absorption LIDAR (DIAL) technology has become a viable technique for detecting, quantifying and pinpointing methane emissions from underground pipelines and operating facilities. This paper describes a number of leak detection survey projects performed throughout North America using the DIAL technology from a fixed wing aircraft. The technology was deployed: • In test situations designed to measure the detection capability and lower detection threshold; • In long distance, large diameter, high pressure natural gas transmission pipelines traversing extremely rugged terrain; • In medium pressure pipelines in populated, higher consequence areas. Results from each of the airborne DIAL leakage survey mission scenarios will be described.
Specification and Manufacturing of Pipes for the X100 Operational Trial
Authors: Johnson James , Hudson Mark , Takahashi Nobuaki , Nagase Makoto , Yamamoto Akio
Published: July 2009

Over the past decade BP and Sumitomo have been developing and promoting the use of X100 grade steel pipe for large diameter high pressure onshore gas pipelines. In 2006, Sumitomo supplied 0.5km of X100 linepipe to BP’s X100 Operational Trial. The X100 Operational Trial is a 48-inch, 180barg X100 pipeline situated in Northumbria, UK, built specifically to advance industry acceptance of the use of X100 in onshore gas pipelines and to demonstrate the long term operational performance of the material under normal and adverse conditions and at higher design factors. In this paper the mechanical properties of the X100 pipes supplied are summarised and background to the linepipe specification and manufacturing process provided. In addition, the effect of specimen type and external coating on mechanical properties is also discussed.
A Novel Alloying Concept for Thermo-Mechanical Hot-Rolled Strip for Large Diameter HTS (Helical Two Step) Line Pipe
Authors: Bremer Sandrine , Flaxa Volker , Knoop Franz M.
Published: July 2009

One of the major priorities of the research and development department of the Salzgitter Group is placed on the product and process optimisation of both approved conventional steel grades for line pipe application and novel high strength alloying concepts. With respect to reduced wall-thicknesses and higher operating pressures for gas transportation pipelines, the requirements for hot wide strip material are steadily increasing. Material strength can be increased either by grain refinement of the ferritic-pearlitic phase in combination with precipitation hardening or by replacing the ferrite-pearlite by an intermediate microstructure, so-called acicular ferrite. A low carbon content supports the formation of the microstructure desired and results in an improvement of the carbon equivalent. This acicular ferrite does not only raise the material strength but also improve low temperature toughness, weldability and workability. New processing routes based on the demands of novel alloying concepts have been developed in order to achieve the intermediate microstructure. In the following paper, two different alloying and processing strategies and the resulting mechanical properties and microstructures are described and illustrated.
Fuel Air Ratio With Accurate Primary and Tempering Air Measurement in a Pulverized Coal Fired Utility
Authors: Brandt Robert O.
Published: July 2009

Fuel/Air balance is the key to clean combustion. Coal-fired public utilities are under constant pressure to meet environmental air quality standards in reducing NOx emissions. Reduction of NOx is critically dependent on controlled combustion conditions. Accurate measurement of the Primary and Tempering Air provides the capability for an improved control scheme. Measuring the Primary and Tempering Air separately avoids the need to measure the mass air flow in the mixed duct where large temperature variations exist. Such variations cause inaccurate, non-repeatable measurements. Very often, when measuring total air flow in a mixed air duct, a change in the Tempering Air damper will cause more of a temperature distribution change than a mass rate change. Erroneous mass flow rate indications and even wrong air flow direction indications are possible. In addition to the Fuel/Air ratio errors that result, unstable control can lead to an operational change from automatic to manual control.
The Nuclear Renaissance: Materials of Choice for Surface Condensers and BOP Heat Exchangers
Authors: Schumerth Dennis J.
Published: July 2009

Amidst the clamor and increasing world demand for energy, the continued use of fossil fuels for electric power generation has recently emerged as the bane of the industry. Green power is being championed as the new fuel de jour kid on the block. Environmentalists and other global warming advocates are successfully lobbying their political agendas for emission caps, carbon sequestration, NOx and SOx and other greenhouse gas limits. In many cases, these efforts have resulted in the outright cancellation, delay or unit reductions of new coal-fired plants. Similarly, simple and combined cycle gas turbine (CCGT) units, popularized during the Enron “gas bubble” era are at the mercy of unstable fuel prices which have, in large part, relegated this generation type from base load to load follow. Wind, biomass, hydro, photovoltaic and other renewables continue to produce an increased percentage of the power base but total contribution remains costly, inefficient and pitifully low. Enter the nuclear renaissance. A dramatic paradigm shift, even by the green power advocates, has allowed the nuclear phoenix to rise with the promise of emission-free power, generation efficiencies, increasing ROI revenues and demonstrating an enviable safety record since TMI and Chernobyl. Assuming this energy source conceives and bears the gestated fruit of a renaissance, the next decade will be telling in terms of the challenges brought forward by licensing, design, financing, construction and operation of a new generation of nuclear power reactors. Paramount among these is a new, time-tested generation of construction materials that will be evaluated to insure a 40 to 60 or even 80 year operational life of these new plants. Consider the problematic copper materials that were chosen during the early 70’s for their high thermal conductivity, competitive cost and ease of fabrication. Contrast these past lessons-learned to current-day, state-of-the-art generation fleet construction standards where demonstrated long-term sustainability coupled with state-of-the-art designs & materials must emerge as the prominent industry players of choice. The paper will examine these and other relevant aspects of the technical and commercial supply chain that is predicted to both challenge and reward designers and material suppliers well into the next decade.
Sensitivity Analysis and Application of Natural Frequency of Torsional Vibration of Rotor System
Authors: He Qing , Du Dongmei
Published: July 2009

The disturbance of electric power system makes large-scale turbine-generator shafts generate torsional vibration. A available method to restrain the torsional vibration of turbine-generator shafts is that all the natural frequencies of torsional vibration of turbine-generator shafts must keep away from the working frequency and its harmonic frequencies as well as all the frequencies that possibly bring on interaction between turbine-generator and electric power system so that the torsional resonation of shafts may not occur. A dynamic design method for natural frequencies of torsional vibration of rotor system based on sensitivity analysis is presented. The sensitivities of natural frequency of torsional vibration to structure parameters of rotor system are obtained by means of the theory of sensitivity. After calculated the torsional vibration dynamic characteristics of original shafts of a torsional vibration stand that simulates the real shafts of 300MW turbine-generator, the dynamic modification for the torsional vibration natural frequency is carried out by the sensitivity analysis method, which makes the first-five natural frequencies of torsional vibration of the stand is very close to the design object. It is proved that the sensitivity analysis method can be used to the dynamic adjustment and optimal design of real shafts of turbine-generator.
AEP’s Crack History: Design Modifications and Lessons Learned on Deaerators and Storage Tanks
Authors: Cashner Bob
Published: July 2009

There are a total of 85 deaerators and their associated 85 storage tanks on American Electric Power’s (AEP) generating system. Two new replacement deaerators were fabricated and installed in 2007 and 2008, otherwise all the remaining vessels were manufactured from 1943 to 1989. The known manufacturers, fabricators and design basis of these vessels will be presented. A total of 158 leak, crack or flow accelerated corrosion (FAC) events to the vessels pressure boundary have been documented on many of AEP’s deaerators and storage tanks over the last 34 years. A majority of the leak or crack events occur on the super-critical deaerators, and eight vessels are responsible for almost 50% of the documented events. The failure mechanisms and initiation sites will also be discussed. An overview will be provided on several design modifications AEP has implemented on the deaerators over the last 20 years. A “Lessons Learned” for specifying new deaerators will be presented for two new replacement deaerators which were fabricated and installed in 2007 and 2008 on AEP’s system.
Analysis of Cycling Impacts on Combined Cycle Heat Recovery Steam Generators and Evaluating Future Costs of Countermeasures to Reduce Impacts
Authors: Lefton Steven A. , Besuner Philip M. , Grimsrud G. Paul , Agan Dwight D. , Grover Jeffrey L.
Published: July 2009

This paper will discuss cycling heat recovery steam generators (HRSG) at combined cycle plants and observed damaging tube temperature transients in the HRSG. APTECH’s cost of cycling methodology is discussed. HRSG transients are selected and the HRSG tube stresses are analyzed using a computerized model to show the effects of cycling on fatigue life of the tubing. Then selected cycling countermeasures to reduce the effect of these transients will be discussed. A method that calculates the benefits of reducing the cyclic cost of the HRSG component damage will be presented along with a benefit-cost analysis.
Evaluation of the Thermal Shock Induced to a Steam Header During Shutdown Conditions
Authors: Bley Steven J. , Karloff Jeffrey A.
Published: July 2009

It is a practice of some utilities to pressurize (hydro) a boiler shortly after the beginning of an outage to check for the presence of boiler tube leaks. If the boiler is drained during shutdown in order to expedite cooling for personnel entry, then the boiler must be filled with relatively cold water in order to perform the hydro. There is a concern that as the cold water contacts the hot metal of the main steam header there is a risk that the thermal shock could cause a crack to form. Numerical and finite element analyses were used to determine the amount of thermal stress induced when varying temperatures of water are applied to the inside surface of a typical main steam header at elevated temperature. The results of the analyses were used to assess the risk of quench cracking and crack propagation.
Incremental Heat Rate and Optimization: New Applications for ASME PTC-PM Performance Monitoring Guideline
Authors: Toburen Tina , Korellis Sam , Milton Joe
Published: July 2009

The ASME Performance Test Code on Performance Monitoring (PTC-PM) provides non-mandatory guidelines for monitoring and optimizing the performance of power generation plants. Plant types covered in the guideline include traditional fossil fired steam cycle plants, simple gas turbines, combined cycle gas turbine based plants, and the steam cycle and balance of plant equipment of nuclear fueled plants. PTC-PM is a comprehensive document, covering such topics as instrumentation selection, monitoring software implementation and containing case studies to explicitly show how performance monitoring can be used to identify and resolve the sources of lost performance. This paper will deal with the new information in one of the updated sections included in the latest version of PTC-PM: Incremental Heat Rate. Incremental heat rate is the ratio of the heat input required for a step change in net power output for a power plant. Incremental heat rates are normally given in units of Btu/kWh or kJ/kWh. Knowing how the incremental heat rate changes from one operating point to another is essential planning the most economical dispatch schedule for a plant. This paper will cover the various aspects of incremental heat rate and its applications, as well as methods for determining incremental heat rate at different facilities in accordance with PTC-PM. Examples of estimated incremental heat rates for a variety of power generation facilities are also provided.
Proposed Otto Cycle/Stirling Cycle Hybrid Engine Based Power Generation System
Authors: Cullen Barry , McGovern Jim
Published: July 2009

The generation of electrical and thermal power is a matter of critical importance to the modern world. Considerable quantities of both power types are required in all sectors of society; industrial, domestic and leisure, with the future prosperity of both developed and developing societies being dependant on generation of both a sufficient quantity and quality of power. Central to this discussion on the international front is the topic of fossil fuel usage. Despite considerable advances in renewable energy conversion technologies, the human race remains dependant on fossil fuels as a primary energy source. With increasing demand for these finite resources giving rise to strained international relations and economic uncertainty, emphasis has fallen on optimization of usage patterns. The area of power plant efficiency is essential to this optimization. This paper proposes a method for increasing the efficiency of an Otto cycle engine based plant as is typically used in CHP and other Distributed Generation scenarios. The method proposed is to utilise a Stirling cycle engine as a heat recovery device on the exhaust stream of the Otto engine. Thermal energy that may otherwise be lost would thereby be recovered and used to generate additional electrical power. In this manner energy is effectively diverted from the exhaust flow of the engine and converted to mechanical work by way of the Stirling cycle engine. It is postulated that this combined cycle will yield higher plant efficiency than the Otto engine alone. This paper introduces work completed to date and an experimental plan for the project. The project was initiated at undergraduate level as a feasibility study for application of the hybrid engine in automotive circumstances. The study suggested that the combination of the engines in the proposed manner was indeed feasible, with significant power gains possible. However, it proved unlikely that automotive application was the best use of the system unless certain constraints were addressed. Therefore, it was decided to pursue the concept in terms of a stationary generation system. The advantages of the stationary system over the automotive system are addressed briefly, with the constraints of the automotive scenario analysed and their relevance to the stationary generation situation examined. The central areas under investigation are detailed, including thermodynamic theory pertaining to the Otto cycle and Stirling cycle engines, and the combined cycles. Possible limiting factors to the design are discussed also.
A Visualizing System for Realtime Display and Adjustment of Cold Air Flow Field in Boiler Furnaces
Authors: Chen Donglin , Li Huiyong , Yuan Jun
Published: July 2009

There are shortages of the currently used methods for measuring and adjusting coal air flow field in a boiler furnace. A tracer-based, image visualizing system is being proposed to provide realtime display, analysis and adjustment of coal air flow. The paper discusses the hardware configuration and function of the proposed system including geometric parameters characterizing the air flow at different location in a boiler furnace. Then, a C++ based software and method, which are used to calculate air flow images’ geometric parameters such as the boundary line, centerline and deflected angle of an air jet from a burner nozzle are introduced. Finally, methods for adjusting the cold air flow field in furnaces with the visualizing system and coupled equations used to optimize the air flow rate of each burner nozzle of a boiler are described.
Experimental Investigation on the Characteristics of Co-Combustion of Rice Straw With Stone Coal
Authors: Pei Xiaochong , Chen Donglin , Wu Li
Published: July 2009

Co-firing rice straw with stone coal, which is a low rank coal with ash content 50–80% and calorific value 3.2–12.93MJ/kg ( on air dry basis), is considered to be a potential method for utilizing 61.87 billions tons of stone coal in China in the near future. In order to understand co-combustion characteristics of rice straw/stone coal blends under different conditions, some experiments were conducted in a thermogravimeter under atmosphere and parameters describing combustion dynamics of the blends, such as activation energy, ignition temperature, burnout characteristics, maximum weight loss rate etc. were obtained. The results show that both of ignition temperature and burnout temperature of the blends decrease promptly when the ratio of rice straw to stone coal increases from 10% to 40%. This implies that co-firing rice straw with stone coal can remarkably improve ignition and burnout performance of stone coals.
Effect of the Power Generation Unit Size on the Energy Performance of Cooling, Heating, and Power Systems
Authors: Fumo N. , Mago P. J. , Chamra L. M.
Published: July 2009

Cooling, Heating, and Power (CHP) systems are a form of distributed generation that can provide electricity while recovering waste heat to be used for space and water heating, and for space cooling by means of an absorption chiller. CHP systems improve the overall thermal energy efficiency of a building, while reducing energy consumption. Since energy conservation has implications on energy resources and environment, CHP systems energy performance should be evaluated based on building primary energy consumption. Primary energy consumption includes the energy consumed at the building itself (site energy) plus the energy used to generate, transmit, and distribute the site energy. The objective of this investigation is to determine the effect of the power generation unit (PGU) size on the energy performance of CHP systems. Since CHP systems energy performance varies with the building energy profiles, in this study the same building is evaluated for three different cities with different climate conditions. This paper includes simulation results for the cases when a CHP system operates with and without a primary energy strategy. Results show that for any PGU size energy savings are guaranteed only when the primary energy strategy is applied. Since CHP system energy performance depends on the building energy use profiles, which depend on climate conditions and other factors such as building characteristic and operation, each case requires a particular analysis in order to define the optimum size of the power generation unit.
Greenhouse Gas Emissions Calculation Methodology in Thermal Power Plants: Case Study of Iran and Comparison With Canada
Authors: Zabihian Farshid , Fung Alan S.
Published: July 2009

Nowadays, the global climate change has been a worldwide concern and the greenhouse gases (GHG) emissions are considered as the primary cause of that. The United Nations Conference on Environment and Development (UNCED) divided countries into two groups: Annex I Parties and Non-Annex I Parties. Since Iran and all other countries in the Middle East are among Non-Annex I Parties, they are not required to submit annual GHG inventory report. However, the global climate change is a worldwide phenomenon so Middle Eastern countries should be involved and it is necessary to prepare such a report at least unofficially. In this paper the terminology and the methods to calculate GHG emissions will first be explained and then GHG emissions estimates for the Iranian power plants will be presented. Finally the results will be compared with GHG emissions from the Canadian electricity generation sector. The results for the Iranian power plants show that in 2005 greenhouse gas intensity for steam power plants, gas turbines and combined cycle power plants were 617, 773, and 462 g CO2eq/kWh, respectively with the overall intensity of 610 g CO2eq/kWh for all thermal power plants. This GHG intensity is directly depend on efficiency of power plants. Whereas, in 2004 GHG intensity for electricity generation sector in Canada for different fuels were as follows: Coal 1010, refined petroleum products 640, and natural gas 523 g CO2eq/kWh, which are comparable with same data for Iran. For average GHG intensity in the whole electricity generation sector the difference is much higher: Canada 222 vs. Iran 610g CO2eq/kWh. The reason is that in Canada a considerable portion of electricity is generated by hydro-electric and nuclear power plants in which they do not emit significant amount of GHG emissions. The average GHG intensity in electricity generation sector in Iran between 1995 and 2005 experienced 13% reduction. While in Canada at the same period of time there was 21% increase. However, the results demonstrate that still there are great potentials for GHG emissions reduction in Iran’s electricity generation sector.