Advanced Compressor Engine Controls to Enhance Operation, Reliability and Integrity
Gary Bourn & Jack Smith - Southwest Research Institute; Warren Lawler – Cooper Compression
This paper presents results from an investigation into methods to enhance operation of integral engine compressors in gas transmission service through application of advanced controls and sensors. The project is funded by the Department of Energy's (DOE) Office of Fossil Energy and managed by the National Energy Technology Laboratory (NETL) as part of their Natural Gas Infrastructure Reliability Program, with co-funding from Cooper Energy Services (CES). A laboratory GMVH-6 turbocharged engine was utilized to provide baseline data in both open-chamber and pre-combustion chamber configurations. Various 'open-loop' control strategies were evaluated with this dataset to determine the robustness of each. Algorithms for 'closed-loop' feedback and adaptive control were developed to enhance the open-loop strategies for more precise control to improve efficiency and integrity at a given emissions level. As part of this process, several sensors were evaluated for their potential use in commercial systems. Of particular focus was a combined fast-response NOX and universal exhaust gas oxygen (UEGO) sensor.
Subjects: Contaminants, Integrity, Reliability
Advanced Empirical Modeling Software Provides Early Warning of Gas Compression Machinery Failure
Patrick Pittman - Panhandle Energy Co./Tim Holtan – SmartSignal
Case studies from the Panhandle Eastern pipeline illustrate the efficacy of the empirical modeling technique in the gas compression industry. First, the engine exhaust gas temperature model normalizes individual power cylinder exhaust temperatures for key independent variables such as engine speed and timing. A case study showing early warning of a fuel injector gasket lead will be presented. Second, the compressor efficiency model detects early signs of compressor cylinder failures. The compressor model analyses the compressor cylinder performance to detect early signs of valve failure, liquid accumulation, and bad pocket operation. A case study showing early detection of a leaking compressor valve will be presented. Finally, the engine efficiency model normalizes engine brake specific fuel consumption for key independent variables to provide early warning of loss of engine or compressor efficiency
Subjects: Failures
Basic Engine & Compressor Analysis Techniques
Ben Boutin, P.Eng. & Bob Webber - Dynalco
Reciprocating compressors and engines have many predictable failure modes which can be detected and corrected before they significantly affect the machine's performance or availability. This short course introduces data collection and analysis techniques that can be used to detect compressor rod failures, valve leaks, ring leaks, and valve dynamics problems; compressor horsepower and capacity inefficiencies from valve leaks, ring leaks, and pulsation; engine mechanical failures like liner scoring, valve train condition, wrist pin knocks and piston slap; engine combustion inefficiencies from ignition timing and firing problems, power cylinder unbalance, and port and valve dynamics. The course focuses on the scientific and physical principles at play rather than on a specific tool. Using the problem-solving techniques outlined in this course, participants will be able to determine what measurements to take, where and how to take them, and how to convert the data into intelligence about their machine's condition and performance.
Subjects: Analysis, Tracer Gas
Basic Thermodynamics of Reciprocating Compression
Greg Phillippi - Ariel Corporation
This short course is intended to provide the attendee a review of the basic thermodynamic principles of compression utilizing a reciprocating compressor. This will include discussions of the pressure-volume diagram, volumetric efficiency, capacity, and adiabatic valve loss and friction horsepower. In addition, the topics of varying conditions, gas analysis, temperature, pulsation, staging and end deactivation horsepower are reviewed.
Subjects: Compression, Thermodynamics
Calculating Reliable Impact Velocity by Mapping Instantaneous Flow in a Reciprocating Compressor
Gunther Machu - Hoerbiger Compression Technology
Calculated impact valve velocities can be twice that of measured impact valve velocities depending on the gas composition and compressor design. An inability to accurately model impact velocities can lead to dramatic consequences in valve design. Current methods for calculating impact velocities assume that cylinder pressure is homogeneous throughout the compression cycle. In this research, the pressure waves that are developed in the cylinder of a reciprocating compressor are mapped It is demonstrated how these pressure fluctuations reduce the differential pressure across the valve and reduce sealing element impact velocities so low that in some cases actually prevent the valve from opening. The effect of dynamic flow inside the cylinder is most significant for large-bore, short-stroke compressors, high-speed compressors and for heavy gas applications.
Robert Goodenough & Dean Huntley - El Paso Corp.; Paul Glandt – Wartsila NA
Gas transmission companies often look to replace antiquated and/or inefficient compressor drivers along their system. This paper presents a case study of the actual performance of engine drives installed at main-line transmission stations to replace antiquated engine/compressors. In this case, the chosen option was a large horsepower (typically 8,000 HP each) four-strong lean burn natural gas engine driving a separable reciprocating compressor. The project involves six engine drive compressor units with site ratings from 7525 to 7700 horsepower that have been in operation since 2001. The paper will review the expected performance and reliability that was considered in the selection of the equipment. Actual performance of the units will be presented along with Operations approach to achieving and maintaining performance and reliability. The importance of effective vendor support in achieving the expected performance is also covered.
Subjects: Performance, Reliability
Case Study: The Revamp of Four 7,000 HP Reciprocating Compressors
Bryan Lettman & Martin Hinchliff - Dresser-Rand
Mechanical failures with reciprocating compressors are both a financial burden and a risk to safety. Occidental Permian LTD has four 20-year old 7,000 horsepower six-throw reciprocating compressors which had routinely been experiencing mechanical failures. These failures were in the form of broken crossheads, distance piece stud failures and excessive vibration. By the way of re-cylindering three throws using modern designs, Dresser-Rand and Occidental Permian LTD were able to eliminate the mechanical failures that had plagued these compressors for years. As a result of this project, these compressors are not only more reliable but also compressing an additional 15% more gas. This project is a perfect example of how a good end user/OEM relationship can result in improved reliability and increased productivity.
Subjects: Failures, Reliability
Compressor Station Ancillary Equipment: Know What You Are Buying, Part I
Michael A. Smith, PE -Texas Gas Transmission, Inc./Fred Mueller - Mueller Environmental Designs
Compressor station design engineers and other design professionals are usually “systems” designers. These professionals design, specify and procure equipment that is engineered and fabricated by others. This course will address the basics of some of the ancillary equipment required to create a natural gas compressor station. This will help the designer to make more informed decisions. The equipment covered in Part 1 will be Natural Gas Separation Equipment, Aerial Coolers and Intake Air Systems. The basic areas covered for each type of equipment are the following: What (is in the pipeline; are you cooling; is in the air), types and/or designs available and their applications, fabrication parameters, specifying your equipment, and analyzing your options. Successful completion of the course will allow design personnel to create more detailed specification sheets and to better analyze the proposals received from suppliers.
Subjects: Design, Equipment, Optimization
Compressor Station Optimization Using Simulation-Based Optimization
Prakash Kirishnaswami, Kirby Chapman & Mohammad Abbaspour – National Gas Machinery Laboratory, Kansas State University
Mathematical modeling is one of the most cost-effective tools that can be used to aid in design, operation and optimization studies. The systems under consideration actually operate in a unsteady nature, and although much effort has been and continues to be spent on unsteady mathematical models, many over-simplifications are introduced that bring into question the simulation results. One of the primary concerns in the operation of a compressor station is minimization of fuel consumption while maintaining the desired throughput of natural gas. In practice, the station operator tries to achieve this by shutting down units or controlling individual unit speeds based on experience. This is generally a train-and-error process without any guarantee of optimality. In this paper, we present a robust structured solution process for tackling this problem using simulation-based optimization.
Subjects: Modeling
Continuous Pressure Monitoring Based Control Systems for Gas Engines
Greg Beshouri - Advanced Engineering Technology Corp./Bryan Willson - Colorado State University/Thomas Walter – Kistler Instrument Corporation
The objective of this short course is to improve knowledge about the technology and application of basic components and to highlight opportunities of pressure based engine monitoring and control systems within the gas machinery industry The following topics and areas will be described in detail: basics of pressure based combustion analysis; determination of efficiency, heat release and relation to emissions; technology and design of piezoelectric pressure sensors; application and installation of piezoelectric pressure sensors in engines; signal conditioning; data acquisition and evaluation software; opportunities for engine monitoring and control; benefits for engine operators.
Subjects: Contaminants, Modeling, Pressure Monitoring
The Contribution of Base Movement in Large Integral Compressors to Frame Cracks
Charles Stanford, P.E. & Keith Schafer – Columbia Gas Transmission
Movement in mils of displacement at various points in the horizontal direction along the side of several large integral compressors has been recorded. These movements have been compared using a fixed crank angle as a common reference point. The reference point used for this data collection is when the number one compressor is at the head end position. This information gives us a picture of how the engine frame is actually flexing when all internal components are in the same position. By comparing plots of movement along the side of the engine, we can observe the relative flexing of the frame at any point in the engine/compressor cycle. It was observed that a reverse bending of the frame is occurring on some types of engine frames which are known to have “typical” frame cracking in the same area that the reverse bending is taking place. Similar plots of movement are also compared between different engine types. The paper will explore the methods of collecting data, the comparison of data on individual engines, and a comparison between different engine frame types. Correlations are drawn between frame movement and cracks in the frame of some engine types. This work lays the foundation for future data collection and testing that could lead to modifications which could reduce frame cracks.
Subjects: Engine Frame, Frames
Deploying Next Generation Two-Stroke Cycle Pipeline Engine Controls Today: A Case Study
Heathcliff Howland & Gavin Goolsbee - Advanced Engine Technology Corporation
This case study describes the successful deployment of industry funded “Next Generation Two-Stroke Cycle Pipeline Engine Control Strategies” at a representative pipeline compressor station on a typical pipeline compressor engine. The Advanced Two-Stroke Cycle Specification previously developed by AETC for the PRCI was used as a template for developing a control system upgrade at Southern California Gas Company's Newberry Springs compressor station. The project discussed in this case study demonstrates that these innovative control strategies can be intelligently integrated into a robust stand along engine automation and control platform that cost effectively maintains emissions compliance while maximizing engine efficiency. This case study will review the project history and then highlight pertinent control and monitoring software detail as well as hardware, installation, and commissioning specifics. Finally, this paper will summarize the emissions control effectiveness of the technology by presenting “before and after” snapshots of the subject engine exhaust emissions.
Subjects: Contaminants
Design Case Study: Foundation for an 8100 HP High-Speed Reciprocating Compressor
Pete Harrell, PE - Southwest Research Institute
This paper presents the process of designing a concrete foundation for an 8,100 HP reciprocating compressor, driven by a natural gas-fueled four-cycle engine at 750 RPM. Such high-speed compressors are typically skid-mounted, but to provide the lowest possible vibration and increase machinery reliability, the decision was made to mount this large compressor directly on a concrete block. The relationship among soil properties, pile sizing, block size, geometry, and foundation dynamics is discussed as are foundation block details, concrete strength, rebar placement, anchor bolt detail, compressor mounting and alignment considerations. The predicted response of the compressor and engine to anticipated dynamic forces is presented.
Subjects: Foundations
John Bartos & Bruce Chrisman - Cooper Compression
New national and local environmental clean air regulations mandate a reduction in CO and formaldehyde (H2CO) emissions from stationary lean burn internal combustion engines greater than 250 horsepower. Oxidizing catalysts have been proven to be effective at reducing these emissions over reasonably long time periods with four-stroke engines, provided there is adequate oxygen in the exhaust for the oxidation process (>1% 02 works best). However, there are several reasons why oxidizing catalysts have not successfully demonstrated high conversion efficiencies over long time periods with two-stroke engines. The reasons for the problems associated with the application of oxidizing converters to two-stroke, lean burn (2SLB) engines include: products from the combustion of the oil that is force fed to the power cylinders of 2SLB engines carry over into the exhaust and degrade the removal efficiency of the oxidizing catalyst; relatively low exhaust temperatures for these engines reduce the oxidizing efficiency; occasional firing in the exhaust during the starting and stopping os 2SLB engines can damage the catalyst element. The Ajax product line of Cooper Compression has completed an oxidizing converter program with the goal of resolving all of the above issues. The research and development program was completed in January of 2004 with limited field testing underway. The end result of the development program is a catalyst and converter housing which will provide satisfactory long term reduction of CO and H2CO for two-stroke lean burn gas engines. The catalyst and converter have been tested extensively at the design rating for the engine, and the oxidizing efficiencies measured at the conclusion of the test program remained nearly equal to the efficiencies recorded at the start of the tests. This paper documents the methodology used to develop the patent pending technology used in the catalytic converter, as well as a presentation of testing results.
Subjects: Catalysts, Emissions, Nox
John Bartos & Bruce Chrisman - Cooper Compression
New national and local environmental clean air regulations mandate a reduction in NOx emissions from stationary lean burn internal combustion engines. The Ajax expansion chamber uses exhaust pulsations to optimize the scavenging of the power cylinders while providing substantial increases in the mass of fresh air that is trapped inside the cylinders. This configuration results in improved performance, cooler combustion, and reduced NOx levels. This tuned exhaust system features diverging and converging sections of pipe. The system produces a negative “rapid scavenging” pulse (vacuum) to facilitate the removal of residual gases from the power cylinders, followed by a large reflected positive pressure pulse to maximize the amount of fresh air that is trapped in the power cylinders. A further benefit of this apparatus is an increase in available horsepower from the engine. The control of scavenging and trapping fresh air is accomplished strictly by the shapes and lengths of the sections of the tuned exhaust system. This method of exhaust emissions reduction does not rely on any moving mechanical devices nor does it require system adjustments and maintenance to achieve the emissions reduction. This paper documents the methodology used to develop the patent pending technology used in the expansion chamber, as well as a presentation of testing results.
Subjects: Emissions
Jeff LaCosse, Ph.D. - Spectral Insights, LLC
With the establishment of EPA Method 320 for both engine and turbine stack testing requirements on regulated IC engines and combustion turbines, the regulatory demand (also via Compliance Assurance Monitoring or CAM) for continuous monitoring of HAP species is expected to grow. This paper reports development of a FTIR CEM system for engines and turbines that meets or exceeds the U.S. EPA's Performance Specification 15 for FTIR CEMs of stationary sources. Some of the advantages of FTIR CEMs, such as significantly reduced calibration gas requirements, no on-site calibration requirement, multiple species monitoring with one instrument, high accuracy measurement of conventional species, spectral data archival for later analysis or other species among others will be discussed. Related topics will include reported problems with conventional NOx analyzers and concerns with calibration gas standard calibration with such instrumentation, and remote system control and data access via various communication protocols.
Subjects: Emissions, Monitoring
Electric Motor Driven Compressors: Basic Principles & Operation
Charles Ely, PE - ACTT, div. of CECO
Electric motors are now considered a valid alternative to reciprocating engines for gas transportation service. In areas where environmental permits are hard to get and electricity is readily available and reasonably prices, operators are installing electric motors as the prime movers for their gas compressors. Electric motors are being used to drive both reciprocating and centrifugal compressors. Electric motors are a relatively new and unusual for traditional operators and field personnel who grew up with reciprocating engines. This short course will provide an introduction to the basic principles and operation of electric motor driven compressors. Discussion topics will include basic construction and principles of electric motors, principles of synchronizing the motor with the electric grid, electric substation basics, fixed speed versus variable speed motor operation, reciprocating compressor configuration and basic operation, and centrifugal compressor configuration and basic operation.
Subjects: Electric Motor Drives
Enhancing Operation of the Existing Natural Gas Compression Infrastructure: Phase I
Tony Smalley, Ralph Harris & Gary Bourn - Southwest Research Institute
This paper presents the results from the first phase of an investigation into methods to enhance operation of integral engine compressors in gas transmission service. The project is funded by the Department of Energy's (DOE) Office of Fossil Energy and managed by the National Energy Technology Laboratory (NETL) as part of their Natural Gas Infrastructure Reliability Program, with co-funding from GMRC and PRCI. A number of technologies and methods have been evaluated and compared with baseline data, including global air fuel ratio control, knock detection for timing control, oil temperature control, high pressure fuel injection, automated combustion balancing, rod load monitoring, and new procedures for combustion balancing in automated or manual systems. Field tests have been performed on an HBA-6T and two GMW10s in active pipeline service, with a suite of instrumentation (including fuel flow, dynamic pressure from all cylinders, lateral and torsional vibration, manifold dynamic pressures, crankshaft dynamic strain, and rod load). A number of evaluations are presented, including the influence on heat rate, compressor thermal efficiency, overall system efficiency, combustion stability, crankshaft integrity, frame vibration, and torsional vibration. Some promising methods are demonstrated and some significant performance benchmarks are set.
Subjects: Horsepower, Infrastructure, Rod Load
Failure Investigation of Large Mainline Compression Equipment: Conclusions of Several Investigations
Charles Stanford, P.E. - Columbia Gas Transmission
This paper will be a brief overview of several failure investigations spanning a twenty-five ear period. The root cause and corrective measures of these failures will be presented. For the past twenty-five years, I have been directly involved in the investigation of many types of failure investigations. This paper will be a compilation of many of the more interesting and somewhat unusual failures, their cause, and an explanation of what was done to keep the failure from reoccurring. This is a case study of several cases, not a training session on how to conduct failure investigations, although some techniques and methods used in these failure investigations will be included.
Subjects: Failures
Field Experience with Rod Load Monitor
Doug Stover – Metrix/PMC Beta/Randy Raymer – El Paso Corp.
This paper reveals practical details in the application of the Southwest Research Institute designed Rod Load Monitor (RLM), for reciprocating compressors in the field, on line, and in operation. The RLM development was funded and directed by GMRC and is unique in that it is self-powered wireless technology measuring rod load directly on reciprocating machinery. The rod load measurement can be used to indicate horsepower and reversal. While the RLM can operate on a variety of reciprocating machines, this paper is confined to reciprocating compressors. The rod load measurement is accomplished with strain gages mounted directly on the compressor rod. The strain signal is amplified and transmitted from a single moving module is generated with a built in, moving linear alternator and stationary magnetic array. Field testing has already begun with some success and some new challenges. The linear alternator on long stroke, slow speed (250 RPM) compressors may need modification or power reduction incorporated in the amplifier transmitter and/or the strain gates. The paper will be based on test results conducted and witnessed by the authors over the Spring and Summer.
Subjects: Rod Load
Fuel Consumption Minimization Under Non-Isothermal Condition at Compressor Stations
Prakash Kirishnaswami, Kirby Chapman & Mohammad Abbaspour – National Gas Machinery Laboratory, Kansas State University
Arguably, the natural gas transmission pipeline infrastructure in the U.S. represents one of the larges and most complex mechanical systems in the world. This system delivers about 0.623 tcm (22 tcf) of natural gas per year and is mad up of over 4.828x105 km (300,000 miles) of pipe driven by 8,000 engines and 1,000 gas turbines with 2.983x105 MW (40 million horsepower) of compression capacity. The system produces over 1.86x109 MW-hrs (250 billion hp-hrs) of compression power every year. One of the goals of operation of this huge system is to find the minimum fuel consumption while maintaining the desired throughput of natural gas. In this paper, we present a systematic approach for operation the units of a compressor station to meet a specified throughput profile. The first step in developing this approach is the derivation of a numerical method for analyzing the flow through the pipeline under transient on-isothermal conditions. We have developed and verified a fully implicit finite difference formulation that provides this analysis capability. Next the optimization of the compressor stations is formulated as a standard nonlinear programming problem (NLP). The minimum acceptable throughput is imposed as a constraint. This NLP is solved numerically by a sequential unconstrained minimization technique, using the mathematical model of the system for the required function evaluations. The results show that this approach is very effective in reducing the fuel consumption. An application of this methodology for selecting the number of compressors to be shutdown for most fuel-efficient operation is also presented. Our results further indicate that station level optimization produces results comparable to those obtained by network level optimization. This is very significant because it implies that the optimization can be done locally at the station level which is computationally much easier.
Subjects: Fuel Control
Fundamentals of Gas Solid/Liquid Separation
Fred Mueller - Mueller Environmental Designs
This paper is an in-depth review of particle physics of gas solid/liquid separation. Topics to be covered include Fundamentals of Gas Solids/Liquids Separation, Particle Formation, Particle Physics, Particle Size, and Particle Motion.
Subjects: Separators
Gas Turbine Fuel Considerations
Rainer Kurz - Solar Turbines Incorporated
Industrial gas turbines allow operation with a wide variety of gaseous and liquid fuels. To determine the suitability for operation with a gas fuel system, various physical parameters of the proposed fuel need to be determined: heating value, dew point, Joule-Thompson coefficient, Wobbe Index and others. However, fuel borne contaminants can also cause engine degradation. Special focus is given to the problem of determining the dew point of the potential fuel gas at various pressure levels. In particular, the treatment of heavier hydrocarbons and water is addressed and recommendations about the necessary data input are made. Since any fuel gas system causes pressure drops in the fuel gas, the temperature reduction due to the Joule-Thompson effect has to be considered and quantified. Suggestions about how to approach fuel suitability questions during the project development and construction phase, as well as in operation are made.
Getting Reliability Through Better Practices on Old Recips
Javier Beret - Skanska Latin America Compression Services
Since most Latin American countries have carried out their former government companies privatization projects, the hardest challenge for the field operations management of compression services suppliers had become how to deal with the gap between the basic equipment condition settled in the contract versus the actual equipment situation. Previous maintenance records policies, historical evolution of preventive and predictive tasks performed, corrective events known (with their causes and solutions), personnel skills levels and external workshop qualification features are crucial factors in order to set up the most suitable strategy. Meanwhile, the labor, spare part and service cost figures will be always mandatory. In addition, each new company could apply different philosophies in the compression service bid terms and contents, not always in concordance with the former owner. The paper shows a successful experience in regard to a current service contract where many of the issues listed were obviously registrable, describing how the changes in the practices improved the performance of the critical and sub-critical equipment involved.
Subjects: Reliability
Grouting Large Skid Mounted Compressor Units
Jack Leary - Reynolds-French & Co./Richard O'Malley - ITW Philadelphia Resins
This short course will provide end users and contractors guidelines and recommendations to follow when grouting large skid units in remote areas. The site location may be 20 to 60 miles from a service source with limited supplies ad services available. Weather is another factor that comes into the mix as installations are carried out year around. Topics to be discussed: Foundation (preparation for grouting), Equipment (mortar mixers, propane heaters, tarps, etc.; provided/leased/source/commitment dates), Pre-Condition Epoxy Material (resin, hardener, aggregate), Epoxy grout (flow vs. clearance), Preparing Forms (header board design, mortar mixers, set up), and Mixing/Pouring Procedures.
Subjects: Foundations, Grouting
How Can I Design an NSCR System That Will Work and How Can I Confirm It?
Greg Beshouri - Advanced Engine Technology Corp./Jon Tice - El Paso Corp./Gregg Arney - Southern California Gas Co.
Rich burn engines fitted with NSCR have become the de facto prime mover of choice for new engine applications in power ranges up to ~1,500 BHP. This is based on their presumed ability to satisfy even the most stringent BACT NOx emissions levels. Concurrently, many currently installed rich burn engine-generators operated by the natural gas pipeline must be converted to NSCR control as part of MACT and/or Title V. But how much do we know about NSCR? How does it work, who offers good technology, what emissions levels can it achieve and maintain, and how can they be simply and cost effectively monitored? This short course will begin to answer those questions and possibly raise just as many.
Subjects: Catalysts, Emissions, NSCR Systems
IEMDC – In-Line Electric Motor Driven Compressor
Michael Crowley, J. Jeffrey Moore & Harry Miller - Dresser-Rand; Prem Bansal & John Tessaro – Curtiss-Wright Corp.
The Inline Electric Motor Drive Compressor (IEMDC) compression system is a uniquely integrated electric motor and compressor combination designed for natural gas pipeline service. The system will be driven by a high-speed, 10 MW induction motor supported on magnetic bearings and powered by a 200 Hz variable frequency drive. A single stage centrifugal compressor impeller is attached to the motor shaft resulting in an integrated compression system. This compression system is highly flexible and efficient and provides low capital expenditure and life cycle cost. It can be quickly ramped up on the pipeline to supply gas during times of peak demands or on a continuous basis. In addition to the low cost, the proposed IEMDC design will also mitigate critical concerns to the gas industry such as environmental, regulatory, and maintenance that are associated with gas fueled driven compression equipment. The IEMDC concept discussed represents a revolutionary advance in electric compression system that addresses the primary requirements of the natural gas industry for an efficient, reliable, and cost effective package. This paper discusses these merits along with a description of the development process of the motor and compressor.
Subjects: Electric Motor Drives
Improvement to Pipeline Compressor Engine Reliability through Retrofit Micro-Pilot Ignition
Bryan Willson – Engine & Energy Conversion Laboratory, Colorado State University
This investigation assesses the benefits of retrofitting a diesel micro-pilot ignition system on low BMEP natural gas pipeline engines. Micro-pilot ignition systems hold promise for being highly reliable, thus maintaining pipeline throughput for prolonged operation, and without a fuel or emissions penalty. The pilot fuel injectors are mounted through an adaptor in one of the spark plug holes in a set of dual-spark plug heads. A high pressure, common-rail, diesel fuel delivery system is employed and customizable power electronics control the current signal to the pilot injectors. Pilot fuel is supplied by a variable displacement, high pressure pump that is driven with an electric motor. Software is developed that interfaces with the pump and controls and monitors the fuel rail pressure. The micro-pilot ignition system program is a 3-year research effort, and Year 2 results will be presented. This research builds upon the first year's efforts, which demonstrated the feasibility of retrofit micro-pilot injection. The demonstration system was optimized using redesigned pilot injectors and evaluated using a “design of experiments” method. Three independent variables: pilot ignition timing, pilot fuel quantity, and pilot fuel rail pressure, are manipulated in order to determine this. Also, overall system design criteria and components specifications were refined. Year 3 involves the field demonstration of the system at two operating compressor stations, and current progress will be reported.
Subjects: Mirco-Pilot Ignition Systems, Reliability
Increased Flexibility of Turbo-Compressors in Natural Gas Transmission through Direct Surge Control
Robert J. McKee & Danny Deffenbaugh - Southwest Research Institute
Surge is a dramatic collapse of flow within a centrifugal compressor which results in reverse flows and potential damage to bearings and other compressor components. The traditional approach to avoiding surge is to recycle flow to maintain a selected minimum rate. However, current external surge control systems result in opening the recycle valve sooner and maintaining a higher flow rate than necessary, which reduces the efficient operating range, wastes fuel, and significantly increases the cost of compressor operation. If an improved surge control system that senses the approach of surge can be implemented, then compressors can be controlled close to surge while avoiding damage. Such a Direct Surge Control System will increase operating range and flexibility and reduce the operating costs of avoiding surge. The Direct Surge Control System described in this paper results from a multi-year research project that is funded by the Department of Energy's (DOE) Office of Fossil Energy and managed by the National Energy Technology Laboratory (NETL) as part of their Natural Gas Infrastructure Reliability Program. The project is co-funded by GMRC and Siemens Energy and Automation, who is participating in the overall project s the surge controller developer and the commercialization partner. This paper presents a brief background, some laboratory test results, and a complete description of the Direct Surge Control System that is being developed and prototype tested at this time. This paper explains the step-by-step process for implementing Direct Surge Control in modern centrifugal compressors. In order to retrofit a field compressor with the current state of this technology, the impeller needs to be of a modern 3D geometry, a drag probe has to be designed (Sized) and fabricated for the gas velocity and density range, a drag probe has to be installed close to the impeller inlet within the compressor with wiring securely mounted and penetrating the compressor's pressure boundary, and the signal needs to be connected to a surge controller designed to use the resulting internal flow recirculation signals. Implementing this improved surge control, that results from this GMRC/DOE research, is not trivial but it has the potential to be cost effective and worthwhile.
Subjects: Surge Control
The Ins & Outs of Sizing a Reciprocating Compressor
David Pearsall - Dresser-Rand
In any compression application there are two conditions that are the most important. They are the “inlet” and the “discharge” conditions. These two conditions can be viewed as “where we are coming from” and “where we need to go”. The process required to determine how to get from one condition to another is similar to a road map. It must get us there in the most efficient and reliable manner. The first step in the selection process is to select the type of compressor. There are many types of compressors, the three main types being screw, centrifugal, and reciprocating. Each compressor type has its' own unique advantages and disadvantages, depending on the application. The goal of this paper is to go through the steps required to size a reciprocating compressor after it has been decided that this is a favorable option. The process includes utilizing fundamental compressor thermodynamics and a basic list of frames and cylinders that are available. The process accounts for the manner in which different gases affect the selection and includes adding sidestreams (positive or negative). The process also includes the comparison of the selection against all equipment limitations and the steps required to ensue that the component design limitations are not exceeded. Current technology allows us to use a manufacturer's program to size a reciprocating compressor and predict performance. Ideally, the program user can expect to input certain key operation parameters, run the program and obtain a correctly sized compressor with properly selected components. However, certain methods can be employed to modify the program output, thus improving the selection.
Subjects: Compressor Sizing
Integrated Design Approach for Reciprocating Compressor Installation
Christine Scrivner & Ralph Harris - Southwest Research Institute
This short course will present the components of an integrated design process for reciprocating compressor installations. Several interrelated analyses will be examined in detail including acoustic analysis, cylinder performance analysis and load prediction, mechanical manifold analysis, piping layout and support review, thermal analysis, torsional analysis and skid/foundation analysis. Guidelines will be discussed that will assist with determining when a particular analysis is appropriate and how it would best be performed. A detailed description of the design methodologies and major concerns associated with each type of analysis will be presented. Case histories will be used to illustrate the key components and potential pitfalls of designing for modern high-speed installations as well as upgrading existing units.
The Intelligent Engine: The Core Building Block for the Intelligent Pipeline
Chad Fletcher & Bryan McCarty – Enginuity
According to projections by the Energy Information Administration (EIA), natural gas demand will grow at an unparalleled rate over the next 20 years. These projections indicate growth from the current level of 22 TCF to over 30 TCF by the year 2013 and 35 TCF by 2020 This comes at a time when the industry's prime mover infrastructure boasts an average age of over 40 years – an infrastructure that struggles to meet peak gas demands today. It is interesting to note that both the marketing/planning and the operational sides of the natural gas industry have both made significant progress over the past ten years, introducing technology and business processes to effectively meet many of the challenges presented by the changing landscape. From a marketing and planning standpoint, these include real-time nomination systems, forward looking demand and systems planning models, and real-time pipeline simulation and scenario models. From an operational standpoint, these include asset management programs, condition based and/or reliability centered maintenance programs, real or near real-time gas control, and advanced diagnostic and early warning systems. However, it would appear that the industry has significant (untapped) opportunities to exploit the synergies of both sides of the business to create what the authors define as the “Intelligent Pipeline”. Furthermore, the authors suggest that the core building block in creating the Intelligent Pipeline is the Intelligent Engine. It should be noted that in many of the advances mentioned above, when outlining needs and opportunities to more fully leverage the technology and business processes, site the lack of accurate and timely information regarding the actual transmission system and its key components. The Intelligent Engine addresses both the need for accurate and real-time information for marketing and planning systems, as well as the advanced controls, monitoring, diagnostics/prognostics needs of advanced asset (productivity and life) management.
Subjects: Contaminants
Introduction to Strategic Sourcing
Donna Sterrick - Duke Energy
This paper will describe how to apply the six-step methodology as a framework to proactively identify opportunities and execute initiatives to achieve sustainable and measurable savings while ensuring safety and reliability across a pipeline system.
Subjects: Strategic Sourcing
Laser Spark Ignition for Natural Gas Fueled Reciprocating Engines
Mike McMillian, Steven Richardson, Steve Woodruff & Dustin McIntyre - National Energy Technology Laboratory
Advancing the state of the art of ignition systems for lean-burn stationary natural gas fueled engines is critical to meeting increased performance requirements. Severely reduced spark plug performance and durability is an unfortunate consequence as engines are simultaneously being pushed to higher power densities and leaner stoichiometry in order to improve efficiency. In order to offset power density losses due to leaner operation high turbo charger boost is used to increase in-cylinder pressure at time of combustion. Fuel lean and high pressure conditions require significant increases in ignition energy to ignite these mixtures when using conventional spark plug technology. Providing the necessary spark energy to operate these engines significantly reduces the service life of present-day spark plugs. The lack of durable spark plugs is a limiting factor in the further development of high efficiency lean burn natural gas reciprocating engines. NETL is working with the DOE-NETL, Natural Gas Infrastructure program and DOE's Office of Energy Efficiency, Advanced Reciprocating Engine Systems (ARES) program with the goal of developing a laser based ignition system. In laser spark ignition, high rates of energetic photons are focused to a point to create a plasma breakdown. Such laser-induced sparks can create instantaneous temperatures and pressures approaching 105 K and 103 atm, respectively with a sudden release of large quantities of reactive and excited chemical species. The laser spark can be positioned at a considerable distance from cylinder boundaries thus eliminating distortions due to wall effects and flame kernel heat loss common in spark plugs. These extreme local conditions relative to the surrounding gas give rise to rapid, supersonic expansion and dissipation of energy leading to ignition even under conditions that would be unignitable for a typical spark ignition system. NETL is currently working to compare a laser spark ignition system with a conventional spark ignition system in a single cylinder natural gas fueled engine as well as bench scale studies into some fundamental issues surrounding the laser spark phenomena. Testing has demonstrated that reductions in emissions and widening of engine misfire margin are simultaneously achievable. In conjunction with studies of the ignition and combustion in engines using laser spark, NETL is developing a prototype low-cost laser spark ignition system. A prototype laser system has been constructed and tested. The results are discussed and solutions provided for improving the laser system output pulse energy and pulse characteristics.
Subjects: Laser
Meeting Regulatory Challenges through Advances in Gas Turbine Emissions Control
Anthony Jones - Solar Turbines Incorporated
The trend to lower gas turbine emission levels over the last 25 years has been driven by regulation, competition, and customer requests. Regulatory requirements are ever-changing and vary significantly around the world. Despite the significant improvement in gas turbine emissions over the last decade, regulatory agencies continue to consider and implement more stringent emission regulations. In the last five years, mid-range gas turbine users in the U.S. have witnessed a large step-change reduction in required emission levels for gas turbines due to the application of NOx add-on control technologies such as Selective Catalytic Reduction (SCR) and CO oxidation catalyst. Emission regulations for industrial gas turbines continue to drive reductions in NOx, CO and UHC. In attempt to avoid the mandate for add-on control gas turbine manufacturers strive to develop DLE gas turbines that will meet the lower levels while increasing the operating range and fuel flexibility. In addition, regulatory pressures are increasing to monitor and control emissions of other species including particulate matter (PM), Sox, and hazardous air pollutants (HAPs) such as formaldehyde. Manufacturers continue DLE gas turbine combustion development work as the preferred approach to meet future requirements. Preventing pollutant formation has been shown to be more cost effective than exhaust clean-up from a life cycle cost perspective. Work is in progress using the latest experimental and analytical development tools to improve emissions and operating flexibility of lean premixed combustion systems The paper will discuss many of the advanced DLE technologies making their way to full commercialization and summarize field experience with the advanced technologies. Operational issues such as cold ambient operation will also be discussed.
Subjects: Emissions
Methodology & Investigation for Determining Start-Up Emissions From Gas Compressor Engines
Michael A. Guerra & Jon K. Tice - El Paso Corp.
In 2003, El Paso sought to quantity emissions of NOx, CO and VOC during startup and shutdown. This paper details many of the challenges encountered in defining terms such as “Startup” and adapting procedures to capture a limited transient event. This work leads us to develop a comprehensive methodology for collecting accurate and repeatable results for these events and implements the test plan on five engines along Tennessee Gas Pipeline. This paper will detail results from a Worthington UTC-168 and a Worthington UTC-168T with tabular and graphical data presented. Results from all five engines will be used to develop LB/hp factors that can be utilized as a tool to estimate the emissions from other natural gas engines.
Subjects: Emissions
Mixing & Combustion Investigations in a Large Bore Optical Engine
Joel Lentz, Jeff Hoss, Daniel Olsen & Bryan Willson, Engines & Engine Conversion Laboratory, Colorado State University
Reduced emissions and increased efficiencies of natural gas pipeline compressor engines are becoming increasingly important. Response to these needs requires detailed understanding of in-cylinder phenomena. The large bore optically accessible engine at Colorado State University was developed for this purpose. That is, to facilitate the study of in-cylinder phenomena in large bore natural gas engines in support of the development of retrofit technologies. This work is comprised of two separate investigations: (1) the study of mixing in a 4-stroke KVS-DT configuration optical engine with high pressure fuel injection and (2) visualization of combustion in a 2-stroke cycle optical engine with GMV cylinder geometry. Necessary optical engine modifications to accommodate 4-stroke operation and combustion are described. Planar laser induced fluorescence is utilized to image mixing for the first investigation; optimum timing for high pressure fuel injection in 4-stroke large bore engines is evaluated. To study combustion, direct imaging of ignition and flame propagation is carried out with a color Kodak Motion-Quarter Ultra high speed video camera.
Subjects: Efficiency, Emissions
Kirby Chapman, Ryan Keller, Ali Keshavarz – National Gas Machinery Laboratory, Kansas State University
A mathematical model of a lean-premixed combustor was developed to determine NOx emissions based on easily measured parameters. These parameters can include ambient pressure/temperature, specific humidity, compressor discharge pressure/temperature, gas generator turbine inlet temperature, and air/fuel mass flow rate. All parameters of interest were modifiable within the model so their effects on NOx production could be studied. The combustor was modeled as several one-dimensional well-stirred gas zones. One-dimensional heat conduction was considered through the combustor wall, with convection on the inside and outside due to the combustion gases and cooling air respectively. Radiation heat transfer between the combustion gases and the combustor wall was also considered using Hottel's zone method. A four-gray gas model was used to handle the nongray characteristics of the combustion gases and treat them as a radiatively participating medium. NOx production was modeled using the extended Zeldovich mechanism along with the N2O-intermediate mechanism, which is important in lean-premixed combustion systems. The resulting determination of NOx production was used to develop relationships between the input parameters and NOx production. In addition, NOx emission and operating parameter data was collected on gas turbines operating in the field. This data was used to determine the values of tunable constants that must be inserted into the NOx relationship for individual gas turbines.
Subjects: Emissions, Modeling, Nox
New Air Regulations Impacting the Natural Gas Industry
Linda Flynn Coerr & Jim McCarthy – Coerr Environmental Corp.
This course will cover the status, content, and potential impact of new U.S. EPA and State Air Regulations affecting gas industry facilities. The course material will include review of rules that have become final in 2004, including Phase II of the NOx SIP Call, the IC Engine MACT Standards, and the Turbine MACT Standard. The course will also look at rules that are under development including the Turbine NSPS Revision, the IC Engine NSPS, implementation of the 8-hour ozone standard, and plans for extending MACT standards to area sources.
Subjects: Emissions
Numerical & Experimental Investigation of Performance Losses in a Clark Turbocharger Compressor
Kirby Chapman, PE & Damian Kuiper - Kansas State University
Common measurements of compressor inlet and outlet air parameters during operation rarely help to understand turbocharger performance. This is due to the fact that the pressure ratio can remain almost constant at different air flow rates through the compressor for a substantial range of turbocharger operation. Measurement of airflow through the compressor helps to get a clear picture of turbocharger operation and degradation. A simple and modified mass flow meter has been tested which works on the principle of a hot wire anemometer and measures local velocity at its placement. Since local velocity inside turbocharger compressor varies with mass flow rate, the indicative velocity can be correlated to the flow rate. To determine proper location of this sensor inside the turbocharger, the flow field inside the compressor was studied by numerical simulation. Behavior of stream-wise and swirl velocity components were identified at different sections of the volume in order to pin-point a location where the flow field is well behaved, i.e., a relatively low degree of swirl and free form dynamic pulses from impeller rotation. The sensor was tested by placing it inside the turbocharger at the NGML test facility. Suitable algorithms were developed to correlate the readings of local velocity with flow rate through the compressor. The sensor readings were found to be an accurate representation of the compressor flow rate. Hence this flow meter may be used in compressor stations to monitor turbocharger performance.
Subjects: Performance
Optimized Compressor Efficiency & Performance Through Thermography
Mark Sproull - Enogex Inc.
This paper will include brief descriptions of thermography as it applies to compression, methods to quantify efficiency and loss, a thermograph program, and compressor fleet and use. It will also describe and give examples of packing leakages, compressor valve leakage, compressor by-pass leakage, dump and drain valve leakage, relief valve leakage, variable volume clearance pocket ring or packing leakage, unintended added compressor cylinder clearance, compressor cooler efficiency, and costs and pay-out.
Subjects: Efficiency, Performance, Thermography
Overview of Compressor Lubricants & Compressor Lubrication
Clint Lingel & Rob Hooley - Ariel Corporation
There are two distinctly different forms of lubrication on a compressor: the gram and the compression cylinders. The frame requires a constant pressurized supply of oil for the rotating drive train. The cylinders require injections of small amounts of oil on a regular basis to lubricate the reciprocating piston rings. The lubricant in each of these applications may be different. Commonly, operators will use engine oil because they have a ready supply of it for the engine. However, this may not be acceptable oil for the compressor. Cylinder and packing oil selection is based on the operating conditions and the type of gas being compressed. Injection rates are based on simple calculations that serve as a starting point. Periodic inspections and operating philosophy should dictate the actual amount of lubrication that is required. In addition, there are applications where synthetic oil is preferred over mineral oil for both the frame and the cylinders.
Subjects: Lubricants, Lubrication
A Physical Interpretation of the Principles & Application of Rotor Dynamics
Krish Ramesh, Ph.D. - Dresser-Rand
The aim of this paper is to provide a physical understanding to rotor dynamics. Rotor dynamics basically deals with the vibration characteristics of rotating machinery. This course covers the principles of lateral vibration of the turbomachinery. Since most of these machines operate in critical services in the oil and gas industries, one has to ensure that the machines operate with a high degree of reliability. The dynamic characteristics of the turbomachinery need to be completely understood before the machine is placed in service. A basic knowledge of the underlying principles of the rotor dynamics will help in a better understanding of the behavior of the rotating machinery.
Subjects: Rotor Dynamics
Reduced Operational Costs via Effective On-Site Storm Water Treatment
Traci Brentano, P.E. - ACTT, div. of CECO
This paper describes how a novel on-site storm water treatment process can be used to dramatically lower monthly expenses associated with oil-contaminated storm water disposal. In areas of the US that experience a lot of rainfall, the costs associated with the disposal of oil contaminated storm water can be a large monthly expense. The treatment process discussed here utilizes collection tanks, skimmers, pumps, an oil water separator, and polysulfone film membranes. The polished water exiting the membranes is clean enough for discharge to the ground or receiving stream whereas the concentrated and dewatered oil can be stored for off-site disposal.
Subjects: Efficiency, Storm Water
Speed Variation: A Study on Torque Made and Consumed
Randy Anderson - ACTT, a div. of CECO
This paper is a case study of the effects of crankshaft configuration and crank referenced unloading devices on engine speed variations. Specifically, the paper focuses on a severe engine speed variation (+/-50 rpm) problem on an Ingersoll-Rand KVSR-412 fitted with a Hoerbiger HydroCOM unloading system. The case study discussed the troubleshooting process used to identify the problems, symptoms, and remedies applied in an effort to eliminate or reduce the speed variation problem. Several basic tests and remedies were applied but none satisfactorily resolved the problem. After further investigation, two primary problems were identified for further investigation and testing. Hoerbiger addressed both of these problems and the speed variation problems were corrected. The most interesting part of this problem was not the solution but whether similar problems exist on high-speed tandem mounted compressor and the angles at which they are coupled to an engine.
Torsional Case Studies on High Speed Separable Reciprocating Compressors
Tom Stephens, P.E. - Ariel Corporation
High alternating torque levels associated with reciprocating compressors can adversely affect the system integrity, especially if the responses are amplified by a torsional resonance. Auxiliary driven equipment failures, coupling failures, and even drive shaft failures have been the result of torsional resonance interference. Most systems usually have a sound torsional design, but there have been some unique situations encountered over the last few years that are worthy of discussion. Several short case studies based on field measurements are presented to show some unique issues concerning the torsional response of different separable compressor systems.
Subjects: Torsional Analysis
Torsional Vibration: The Value of the Field Verification
Rodney Varty, E.I.T. & John Harvey, P.Eng. - Beta Machinery Analysis, Ltd.
Torsional modeling of reciprocating machinery systems is critical to the reliability of the installation. Differences in construction, error in manufacturer information or other variables can, and occasionally do, prevent the prediction from matching reality. This has lead to major failures and lost production. This paper examines the variables that can affect the accuracy of torsional modeling: differences in crankshaft data when calculated with industry-related standard techniques and finite element analysis, electric motor rotor stiffness, coupling installation, and reciprocating compressor loading and performance. Finally, a case history where “twin” units have distinctively different torsional vibration is presented. One unit had electric motor rotor and shaft failures, while the other unit has not had any torsional failures. Did the “good twin” have a failure that prevented catastrophic shut down?
Subjects: Torsional Vibration
Robert J. McKee - Southwest Research Institute
Surge in centrifugal compressors cannot, in general, be avoided when a unit trip or a major upset occurs, but the energy of surge should be minimized. Surge is a dramatic collapse of flow within a centrifugal compressor, which results in reverse flows within the machine and attached piping and can cause damage to bearings and other components. During normal and slowly changing operations, surge can be avoided by recycling gas through the surge control valve to maintain a minimum flow. However, when a trip or major upset occurs, flow rate drops and the primary means by which surge energy can be reduced is to lower the head (suction to discharge pressure difference) at which the compressor reaches the surge (minimum stable) flow condition. The head across a compressor during a trip or upset is dependent on the response of the entire system including changing performance of the compressor, transient flows within the piping, control system responses, and capacity and opening rate of surge and other automatic valves, such as vent or blow down valves, and check valves. This paper describes tools and techniques that can and have been used to model transient flows and performance, mechanical and control responses, and time dependent head in compressor systems. The tools used by SwRI include a method of characteristic transient flow analysis routine and finite time step programs that simulate control systems, valve actuators, and the opening (or closing) rate of valves with the resulting flows. The effects of volumes and lengths of station piping, scrubbers, and coolers including temperature effects are accounted for. Computer models also track the performance of centrifugal compressors at different speeds, account for the rotation inertia of compressor trains, and evaluate the thermophysical properties of gas streams. These computer routines have been integrated into a computer process that evaluates the design of entire compressor systems including recycle and other valves, valve actuators, and control logic for the ability to minimize surge energy in the event of unit trips or major compressor upsets. This paper provides examples of the factors in centrifugal compressor designs that provide the best trip or upset performance.
Subjects: Contaminants, Flow, Surge Control
Turbocharger Reliability Issues on Caterpillar G3600 Series Engines
William Couch, PE - El Paso Corp./ Mitch Opat - Universal Compression
Since the introduction of the natural gas Caterpillar 3600 Series Engines in the nineties, operators of these engines have been plagued with chronic turbocharger failures resulting from deposit buildup (fouling) on the turbine blades. This paper will include at a minimum the following sections: investigate the casual factors surrounding turbocharger fouling; investigate methods of preventing the deposit buildup on the turbine parts; delve into the statistic regarding the number and types of turbochargers affected by the fouling buildup; discuss the actual costs involved in the repair/replacement of both ailing and failed turbochargers; look into the economics of repairing or replacing turbochargers prior to catastrophic failure; review methods of detecting eminent failure, thus allowing the turbochargers to be removed from service before a catastrophic failure; investigate the root cause of the deposit buildup on the turbine parts and review possible methods of preventing catastrophic failures of the turbochargers.
Subjects: Reliability, Turbochargers
Understanding the Pulsation & Vibration Control Concepts in the New API 618 (Fifth Edition)
Ken Atkins & Jim Tison - Engineering Dynamics, Inc./Alan Pyle - Shell Global Solutions (US)
The new Fifth Edition of API 618 has recently been published. Significant changes have been incorporated in the section concerning pulsation and vibration control. Guidelines are included for when to perform certain analyses (that were optional in the Fourth Edition) based on pressure pulsation and shaking force levels determined from the acoustical simulation. This eliminates the confusion concerning when piping forced mechanical response calculations should be performed. The purpose of the short course is to provide the user with a working knowledge of good engineering practices for pulsation and vibration control in reciprocating machinery commonly used in the natural gas industry. An in-depth explanation of the changes in API 618 and the differing design philosophies will be presented. Several examples cases illustrating design concepts will be used.
Subjects: API 618, Pulsation, Vibration
Kirby Chapman – National Gas Machinery Laboratory, Kansas State University/Hans Mathews - Hoerbiger Gas Engine Systems Div./Greg Beshouri - Advanced Engine Technology Corp.
This short course focuses on using a set of normalized engine parameters to determine engine emissions performance under a wide variety of operating conditions. The modeling techniques presented have been successfully used to determine the air requirements for many different engine models and to explain the differences in performance observed within engine families. This short course considers in detail the effects of scavenging and trapping on engine emissions. This short course will introduce a series of mathematical equations that are solved to determine the air manifold conditions that are necessary to achieve a specific emissions level from an engine. A Sample model will be created for the Cooper GMW series of engines that not only can be used to predict emissions, but also demonstrates the effects of trapping and scavenging on emissions. Considered in the example are the GMWA, GMWC and GMWH (C models converted to pure turbocharged) engines. Differences in emissions performance based on the scavenging configuration are fully explored. The authors intend to teach the methods that have been developed and then illustrate how these methods are used when modeling for emissions. The purpose of the course is to document ad demonstrate the science that underlies the art of creating emissions based air specifications.
Subjects: Emissions, Scavenging
Carol Palynchuk - Beta Machinery Analysis, Ltd.
A typical gas storage facility is a long-term investment that relies heavily on the efficient and reliable operation of multiple high horsepower reciprocating compressors. The compressors must be capable of operating at a very wide range of operating conditions and flows. An additional factor is that gas control demands may dictate that a unit starts and stops a number of times in a single day. This paper looks at a number of the vibration and performance design aspects of a multi-recip compressor storage facility and provides suggestions for initial layout and goals for the necessary design studies. Some of the issues discussed are common sense approaches to pulsation filtering considering of extremes in compressor loading and unit and piping layout and support strategies to avoid vibration interaction between units and with operators and instrumentation.
Subjects: Design, Performance, Vibration
