This document summarizes three case studies that demonstrate how simulation of reciprocating compressor valve dynamics can help optimize valve design and troubleshoot problems. Case 1 shows that reducing valve lift can increase compressor capacity while decreasing impact velocities and improving valve life. Case 2 illustrates that inadequate valve flow area leads to late valve closure and failure, and increasing flow area is needed. Case 3 demonstrates that considering cylinder flow area in simulations, in addition to valve design, is important, as insufficient cylinder area was constricting gas flow and wasting horsepower. Overall, valve simulation allows comprehensive evaluation of designs and selection of solutions that perform well over all operating conditions.
Design Considerations for Antisurge Valve SizingVijay Sarathy
This document provides guidelines for sizing an anti-surge valve for a centrifugal compressor. It begins with definitions of surge and how it can damage compressors. It then outlines the methodology for sizing an anti-surge valve, which involves calculating the valve coefficient based on parameters like mass flow rate, pressure ratio, piping geometry, and gas properties. The document provides a case study applying this methodology to size a 4" anti-surge valve for a gas compressor system operating between 11.61 and 30.13 bara.
Production optimization using gas lift techniqueJarjis Mohammed
After completed the drilling, set the tubing and completed the well successfully, Petroleum engineers realize that the hydrocarbon fluid won't lift up from bottom hole to the surface by its reservoir drives which are mainly gas cap or water drive. Simply the gas lift technique is to reduce the density of hydrocarbon fluid inside the well to lift it to the surface by injecting compressed gas.
Artificial lift technology uses mechanical devices like pumps or velocity strings to increase the flow of liquids like oil or water from production wells. Artificial lift is needed when reservoir pressure is insufficient to lift fluids to the surface. Common artificial lift systems include reciprocating rod lift, progressing cavity pumping, hydraulic lift, gas lift, plunger lift, and electric submersible pumping. The appropriate system depends on factors like well characteristics, reservoir properties, fluids, surface constraints, and economics. Key components include pumping units, motors, sucker rods, pumps and accessories. Benefits include flexibility and ability to optimize production levels. Limitations depend on the specific system but may include depth rating, temperature sensitivity, fluid properties, or need for a
Oil & Gas Pipelines are often subjected to an operation called ‘Pigging’ for maintenance purposes (For e.g., cleaning the pipeline of accumulated liquids or waxes). A pig is launched from a pig launcher that scrapes out the remnant contents of the pipeline into a vessel known as a ‘Slug catcher’. The term slug catcher is used since pigging operations produces a Slug flow regime characterized by the alternating columns of liquids & gases. Slug catcher’s are popularly of two types – Horizontal Vessel Type & Finger Type Slug catcher. However irrespective of the type used, the determination of the slug catcher volume becomes the primary step before choosing the slug catcher type.
Production Optimization using nodal analysis. The nodal systems analysis approach is a very flexible method
that can be used to improve the performance of many well
systems. The nodal systems analysis approach may be used to analyze
many producing oil and gas well problems. The procedure can
be applied to both flowing and artificial
Design Considerations for Antisurge Valve SizingVijay Sarathy
This document provides guidelines for sizing an anti-surge valve for a centrifugal compressor. It begins with definitions of surge and how it can damage compressors. It then outlines the methodology for sizing an anti-surge valve, which involves calculating the valve coefficient based on parameters like mass flow rate, pressure ratio, piping geometry, and gas properties. The document provides a case study applying this methodology to size a 4" anti-surge valve for a gas compressor system operating between 11.61 and 30.13 bara.
Production optimization using gas lift techniqueJarjis Mohammed
After completed the drilling, set the tubing and completed the well successfully, Petroleum engineers realize that the hydrocarbon fluid won't lift up from bottom hole to the surface by its reservoir drives which are mainly gas cap or water drive. Simply the gas lift technique is to reduce the density of hydrocarbon fluid inside the well to lift it to the surface by injecting compressed gas.
Artificial lift technology uses mechanical devices like pumps or velocity strings to increase the flow of liquids like oil or water from production wells. Artificial lift is needed when reservoir pressure is insufficient to lift fluids to the surface. Common artificial lift systems include reciprocating rod lift, progressing cavity pumping, hydraulic lift, gas lift, plunger lift, and electric submersible pumping. The appropriate system depends on factors like well characteristics, reservoir properties, fluids, surface constraints, and economics. Key components include pumping units, motors, sucker rods, pumps and accessories. Benefits include flexibility and ability to optimize production levels. Limitations depend on the specific system but may include depth rating, temperature sensitivity, fluid properties, or need for a
Oil & Gas Pipelines are often subjected to an operation called ‘Pigging’ for maintenance purposes (For e.g., cleaning the pipeline of accumulated liquids or waxes). A pig is launched from a pig launcher that scrapes out the remnant contents of the pipeline into a vessel known as a ‘Slug catcher’. The term slug catcher is used since pigging operations produces a Slug flow regime characterized by the alternating columns of liquids & gases. Slug catcher’s are popularly of two types – Horizontal Vessel Type & Finger Type Slug catcher. However irrespective of the type used, the determination of the slug catcher volume becomes the primary step before choosing the slug catcher type.
Production Optimization using nodal analysis. The nodal systems analysis approach is a very flexible method
that can be used to improve the performance of many well
systems. The nodal systems analysis approach may be used to analyze
many producing oil and gas well problems. The procedure can
be applied to both flowing and artificial
Wrong Sizing of a Reciprocating CompressorLuis Infante
Performance mapping has become a key analytical tool for the diagnostic and optimization of recip compressors, together with electronic performance analyzers. This analysis case illustrates how difficult is to operate a thermodynamically unbalanced multistage integral compressor in a borderline application. An in-house plotting routine in MS Excel (R) was used to map the basic performance (power and flow) of the individual stages across the operating range, and also to produce special-purpose maps in order to graphically depict other mechanical limits, thus helping the field operators to find (and avoid) the root cause of major troubles, including a catastrophic crankshaft failure. Mitigation and remedial cases are explored.
This document describes an experiment conducted to demonstrate and measure fluid flow rates using different flow meter types. The experiment utilized a hydraulic bench unit with a volumetric measuring tank and submersible pump. Three common flow meters were tested: a rotameter, venture meter, and orifice plate. Readings were taken from each meter and calculations were performed to determine flow rates and discharge coefficients. Plots were made comparing actual flow rates to measured rates from each meter. The results showed the relationships between variables and effectiveness of different flow meter designs.
This document outlines the syllabus for the CC303 Hydraulics 1 course offered at a Malaysian polytechnic. The 15-week course introduces students to fluid behavior and applications in civil engineering. Students will study fluid characteristics, pressure, Bernoulli's theorem, energy losses, pipe flow, and open channel flow. They will also conduct hands-on laboratory experiments. The course aims to help students apply fluid mechanics principles to solve problems and demonstrate teamwork skills through collaborative lab work. Assessment includes tests, quizzes, practical skills evaluations, and a final exam.
This document provides information on gas lift valve mechanics, including the three basic types of gas lift valves, how they operate, and the forces involved in opening and closing them. It discusses unloading valves, orifice valves, and how gas lift valves close in sequence from the bottom of the well upward. Diagrams show the components of different gas lift valve designs and the formulas used to calculate valve opening and closing pressures.
This document summarizes a parametric study evaluating design parameters for pulsation dampeners on plunger pumps. The study uses a pulsation model to examine the effects of:
1) Pump system configuration, finding that complex piping can significantly impact pulsations compared to just the pump package.
2) Dampener location, finding pulsations generally increase as the dampener moves farther from the pump, and are still high when located next to the pump due to quarter-wave resonances.
3) Dampener neck geometry, finding pulsations decrease with a larger neck diameter and shorter neck length to maximize the dampener's effect.
The study also examines the impacts of fluid compressibility and
Horizontal Well Performance Optimization AnalysisMahmood Ghazi
The document discusses optimization of production from horizontal wells using nodal analysis and the PROSPER software. It outlines factors that affect pressure losses in horizontal and inclined well sections and describes how nodal analysis can be used to model well deliverability and optimize parameters like well length. Results from PROSPER simulations show how inlet pressure, pressure drop, and flowrate increase with longer well lengths up to an optimal value. The document concludes horizontal wells can be optimized for production using nodal analysis and PROSPER to evaluate factors affecting pressure losses and choose well parameters.
The document provides information on production optimization through system analysis using nodal analysis. It discusses key components of the production system including reservoir fluid properties, inflow performance, tubing performance, and how to analyze the combined system. The objectives are to understand inflow, vertical lift, and combined performance. Nodal analysis is introduced as a technique to simulate fluid flow by breaking the system into nodes and ensuring pressure continuity. An example application optimizes a well's production rate by analyzing effects of tubing size, wellhead pressure, water cut, and skin on the combined inflow and outflow curves. The optimized design achieves a production rate of 114 MMscf/d with a 6.18" tubing and 2,000 psi
A hydraulic ram can be assembled from standard plumbing parts to pump water to higher elevations. The document provides instructions on assembling the ram from fittings like pipes, tees, valves, and a pressure tank. It also provides guidance on adjusting the ram for proper pumping by tweaking the swing check valve angle or drive pipe length.
This document outlines technical requirements for positive displacement pumps used in the petroleum, chemical, and gas industries according to API 675 standards. It covers hydraulic diaphragm and packed plunger pump designs, excluding rotary pumps. Requirements include materials of construction, pressure containment, liquid end connections, flanges, check valves, diaphragms, relief valves, gears, bearings, lubrication, capacity control, and accessories like drivers, motors, couplings and guards.
This document summarizes experimental work characterizing the performance of a two-phase flow pump. It describes the experimental loop used to test the pump under single-phase and two-phase flow conditions. The document also outlines instrumentation used to measure pump parameters like pressure, void fraction, and flow rates. Charts show experimental data on the pump's pressure distribution and performance at varying flow rates, pressures, and void fractions, along with comparisons to predictive models of single-phase and two-phase pump behavior. The conclusion calls for more experiments to develop more accurate predictive models of two-phase pump performance.
This document provides information about gas lift optimization. It discusses the need for gas lift when wells are not producing through natural flow. Gas lift involves injecting natural gas into the well to lift fluids to the surface. The document outlines the basic principles of gas lift and gas lift systems. It describes how gas lift valves work and the process of unloading a well using multiple unloading valves. The goal of optimization is to find the optimal injection point and amount of gas injected to maximize oil production rates. Charts are provided showing well performance curves with injection rate versus oil rate.
The document provides guidance on testing the water tightness of pipes before final backfilling. It recommends testing the entire system, including connections, manholes, and inspection chambers. Two methods of testing are described: testing with air, which is only suitable for pipelines, and testing with water, which can test the entire system. The water testing method involves filling the test section with water up to a maximum pressure of 50 kPa and maintaining the pressure for 30 minutes, adding no more than a specified volume of water during that time for the test to pass. Individual joints over DN1000 can also be tested instead of the whole pipeline. Visual inspection and as-built documentation are also required before finalizing the tests.
Home Made Hydraulic Ram Pump - Part 1
`
For more information, Please see websites below:
`
Organic Edible Schoolyards & Gardening with Children =
http://scribd.com/doc/239851214 ~
`
Double Food Production from your School Garden with Organic Tech =
http://scribd.com/doc/239851079 ~
`
Free School Gardening Art Posters =
http://scribd.com/doc/239851159 ~
`
Increase Food Production with Companion Planting in your School Garden =
http://scribd.com/doc/239851159 ~
`
Healthy Foods Dramatically Improves Student Academic Success =
http://scribd.com/doc/239851348 ~
`
City Chickens for your Organic School Garden =
http://scribd.com/doc/239850440 ~
`
Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica
http://scribd.com/doc/239850233
`
Simple Square Foot Gardening for Schools - Teacher Guide =
http://scribd.com/doc/239851110 ~
Surge Pressure Prediction for Running Linerspvisoftware
This white paper will review the engineering analysis behind trip operations for different pipe end conditions. The author will discuss the controlling parameters affecting surge pressure using SurgeMOD. There are 2 aspects of the surge and swab pressure analysis: one is to predict surge and swab pressure for a given running speed (analysis mode), while the other one is to calculate optimal trip speeds at different string depths without breaking down formations or causing a kick at weak zone (design mode). This article will address both issues. Examples of running liners in tight tolerance wellbore will be analyzed.
This document contains 15 fluid mechanics assignment problems related to flow rate, pressure, head loss, and pipe sizing calculations for various pipe configurations and flow conditions. The problems involve liquids like water, oil, and gasoline flowing through pipes, ducts, and between reservoirs. The student is asked to use principles of fluid mechanics to analyze the systems and calculate unknown parameters like flow rate, pressure, power required, and pipe diameter.
When altitude increases, water's boiling point decreases as pressure drops. For every 27mmHg increase in pressure, boiling point rises 1°C. Water vaporizes based on temperature and pressure. NPSHa is the available positive suction head, calculated as total suction head minus vapor pressure. NPSHR is the required positive suction head to avoid cavitation. Cavitation can damage pumps when NPSHa is less than NPSHR. Engineers must ensure sufficient margin between liquid and vapor states.
The document provides information about the boiler feed water pump system used in a power plant, including its purpose, components, technical specifications, maintenance procedures, and troubleshooting guidelines. The system consists of a booster pump and larger feed water pump coupled together and driven by a single electric motor. Key components are described in detail, such as the pumps, turbo coupling, motor, and balancing device. Periodic maintenance tasks and clearances are outlined. Common issues that may arise are identified along with recommended solutions.
This paper investigates excessive fuel consumption of
compressor drivers caused by common compressor faults.
Pressure versus volume (PV) analysis techniques will identify
deficiencies, quantify fault severity, and will be used to
estimate the resulting excessive fuel consumption. Empirical
fuel measurements of the drivers are analyzed before and
after the fault correction and are used to calculate immediate
economic savings from repairs. Performance and capacity
improvements are also analyzed, providing a complete economic
picture of maintenance and operational payback.
This document provides an overview of Module 5 of a Process Engineering Training Program on fan measurement and testing. The module covers topics such as fan pressure, fan curves, fan laws, controlling fan output, unsatisfactory fan performance, series fans, parallel fans, blade types, fan noise, and other gas pumping equipment. It includes definitions of key fan terms, equations, diagrams of fan setups and performance, and factors that affect fan operation. The module aims to teach trainees how to measure, analyze, and optimize the performance of industrial fans used in chemical processes.
Wrong Sizing of a Reciprocating CompressorLuis Infante
Performance mapping has become a key analytical tool for the diagnostic and optimization of recip compressors, together with electronic performance analyzers. This analysis case illustrates how difficult is to operate a thermodynamically unbalanced multistage integral compressor in a borderline application. An in-house plotting routine in MS Excel (R) was used to map the basic performance (power and flow) of the individual stages across the operating range, and also to produce special-purpose maps in order to graphically depict other mechanical limits, thus helping the field operators to find (and avoid) the root cause of major troubles, including a catastrophic crankshaft failure. Mitigation and remedial cases are explored.
This document describes an experiment conducted to demonstrate and measure fluid flow rates using different flow meter types. The experiment utilized a hydraulic bench unit with a volumetric measuring tank and submersible pump. Three common flow meters were tested: a rotameter, venture meter, and orifice plate. Readings were taken from each meter and calculations were performed to determine flow rates and discharge coefficients. Plots were made comparing actual flow rates to measured rates from each meter. The results showed the relationships between variables and effectiveness of different flow meter designs.
This document outlines the syllabus for the CC303 Hydraulics 1 course offered at a Malaysian polytechnic. The 15-week course introduces students to fluid behavior and applications in civil engineering. Students will study fluid characteristics, pressure, Bernoulli's theorem, energy losses, pipe flow, and open channel flow. They will also conduct hands-on laboratory experiments. The course aims to help students apply fluid mechanics principles to solve problems and demonstrate teamwork skills through collaborative lab work. Assessment includes tests, quizzes, practical skills evaluations, and a final exam.
This document provides information on gas lift valve mechanics, including the three basic types of gas lift valves, how they operate, and the forces involved in opening and closing them. It discusses unloading valves, orifice valves, and how gas lift valves close in sequence from the bottom of the well upward. Diagrams show the components of different gas lift valve designs and the formulas used to calculate valve opening and closing pressures.
This document summarizes a parametric study evaluating design parameters for pulsation dampeners on plunger pumps. The study uses a pulsation model to examine the effects of:
1) Pump system configuration, finding that complex piping can significantly impact pulsations compared to just the pump package.
2) Dampener location, finding pulsations generally increase as the dampener moves farther from the pump, and are still high when located next to the pump due to quarter-wave resonances.
3) Dampener neck geometry, finding pulsations decrease with a larger neck diameter and shorter neck length to maximize the dampener's effect.
The study also examines the impacts of fluid compressibility and
Horizontal Well Performance Optimization AnalysisMahmood Ghazi
The document discusses optimization of production from horizontal wells using nodal analysis and the PROSPER software. It outlines factors that affect pressure losses in horizontal and inclined well sections and describes how nodal analysis can be used to model well deliverability and optimize parameters like well length. Results from PROSPER simulations show how inlet pressure, pressure drop, and flowrate increase with longer well lengths up to an optimal value. The document concludes horizontal wells can be optimized for production using nodal analysis and PROSPER to evaluate factors affecting pressure losses and choose well parameters.
The document provides information on production optimization through system analysis using nodal analysis. It discusses key components of the production system including reservoir fluid properties, inflow performance, tubing performance, and how to analyze the combined system. The objectives are to understand inflow, vertical lift, and combined performance. Nodal analysis is introduced as a technique to simulate fluid flow by breaking the system into nodes and ensuring pressure continuity. An example application optimizes a well's production rate by analyzing effects of tubing size, wellhead pressure, water cut, and skin on the combined inflow and outflow curves. The optimized design achieves a production rate of 114 MMscf/d with a 6.18" tubing and 2,000 psi
A hydraulic ram can be assembled from standard plumbing parts to pump water to higher elevations. The document provides instructions on assembling the ram from fittings like pipes, tees, valves, and a pressure tank. It also provides guidance on adjusting the ram for proper pumping by tweaking the swing check valve angle or drive pipe length.
This document outlines technical requirements for positive displacement pumps used in the petroleum, chemical, and gas industries according to API 675 standards. It covers hydraulic diaphragm and packed plunger pump designs, excluding rotary pumps. Requirements include materials of construction, pressure containment, liquid end connections, flanges, check valves, diaphragms, relief valves, gears, bearings, lubrication, capacity control, and accessories like drivers, motors, couplings and guards.
This document summarizes experimental work characterizing the performance of a two-phase flow pump. It describes the experimental loop used to test the pump under single-phase and two-phase flow conditions. The document also outlines instrumentation used to measure pump parameters like pressure, void fraction, and flow rates. Charts show experimental data on the pump's pressure distribution and performance at varying flow rates, pressures, and void fractions, along with comparisons to predictive models of single-phase and two-phase pump behavior. The conclusion calls for more experiments to develop more accurate predictive models of two-phase pump performance.
This document provides information about gas lift optimization. It discusses the need for gas lift when wells are not producing through natural flow. Gas lift involves injecting natural gas into the well to lift fluids to the surface. The document outlines the basic principles of gas lift and gas lift systems. It describes how gas lift valves work and the process of unloading a well using multiple unloading valves. The goal of optimization is to find the optimal injection point and amount of gas injected to maximize oil production rates. Charts are provided showing well performance curves with injection rate versus oil rate.
The document provides guidance on testing the water tightness of pipes before final backfilling. It recommends testing the entire system, including connections, manholes, and inspection chambers. Two methods of testing are described: testing with air, which is only suitable for pipelines, and testing with water, which can test the entire system. The water testing method involves filling the test section with water up to a maximum pressure of 50 kPa and maintaining the pressure for 30 minutes, adding no more than a specified volume of water during that time for the test to pass. Individual joints over DN1000 can also be tested instead of the whole pipeline. Visual inspection and as-built documentation are also required before finalizing the tests.
Home Made Hydraulic Ram Pump - Part 1
`
For more information, Please see websites below:
`
Organic Edible Schoolyards & Gardening with Children =
http://scribd.com/doc/239851214 ~
`
Double Food Production from your School Garden with Organic Tech =
http://scribd.com/doc/239851079 ~
`
Free School Gardening Art Posters =
http://scribd.com/doc/239851159 ~
`
Increase Food Production with Companion Planting in your School Garden =
http://scribd.com/doc/239851159 ~
`
Healthy Foods Dramatically Improves Student Academic Success =
http://scribd.com/doc/239851348 ~
`
City Chickens for your Organic School Garden =
http://scribd.com/doc/239850440 ~
`
Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica
http://scribd.com/doc/239850233
`
Simple Square Foot Gardening for Schools - Teacher Guide =
http://scribd.com/doc/239851110 ~
Surge Pressure Prediction for Running Linerspvisoftware
This white paper will review the engineering analysis behind trip operations for different pipe end conditions. The author will discuss the controlling parameters affecting surge pressure using SurgeMOD. There are 2 aspects of the surge and swab pressure analysis: one is to predict surge and swab pressure for a given running speed (analysis mode), while the other one is to calculate optimal trip speeds at different string depths without breaking down formations or causing a kick at weak zone (design mode). This article will address both issues. Examples of running liners in tight tolerance wellbore will be analyzed.
This document contains 15 fluid mechanics assignment problems related to flow rate, pressure, head loss, and pipe sizing calculations for various pipe configurations and flow conditions. The problems involve liquids like water, oil, and gasoline flowing through pipes, ducts, and between reservoirs. The student is asked to use principles of fluid mechanics to analyze the systems and calculate unknown parameters like flow rate, pressure, power required, and pipe diameter.
When altitude increases, water's boiling point decreases as pressure drops. For every 27mmHg increase in pressure, boiling point rises 1°C. Water vaporizes based on temperature and pressure. NPSHa is the available positive suction head, calculated as total suction head minus vapor pressure. NPSHR is the required positive suction head to avoid cavitation. Cavitation can damage pumps when NPSHa is less than NPSHR. Engineers must ensure sufficient margin between liquid and vapor states.
The document provides information about the boiler feed water pump system used in a power plant, including its purpose, components, technical specifications, maintenance procedures, and troubleshooting guidelines. The system consists of a booster pump and larger feed water pump coupled together and driven by a single electric motor. Key components are described in detail, such as the pumps, turbo coupling, motor, and balancing device. Periodic maintenance tasks and clearances are outlined. Common issues that may arise are identified along with recommended solutions.
This paper investigates excessive fuel consumption of
compressor drivers caused by common compressor faults.
Pressure versus volume (PV) analysis techniques will identify
deficiencies, quantify fault severity, and will be used to
estimate the resulting excessive fuel consumption. Empirical
fuel measurements of the drivers are analyzed before and
after the fault correction and are used to calculate immediate
economic savings from repairs. Performance and capacity
improvements are also analyzed, providing a complete economic
picture of maintenance and operational payback.
This document provides an overview of Module 5 of a Process Engineering Training Program on fan measurement and testing. The module covers topics such as fan pressure, fan curves, fan laws, controlling fan output, unsatisfactory fan performance, series fans, parallel fans, blade types, fan noise, and other gas pumping equipment. It includes definitions of key fan terms, equations, diagrams of fan setups and performance, and factors that affect fan operation. The module aims to teach trainees how to measure, analyze, and optimize the performance of industrial fans used in chemical processes.
The document discusses the benefits of standby time in adsorption dehydration processes. It describes how molecular sieves are used to dehydrate natural gas and how their capacity declines over cycles due to loss of structure. Having excess regeneration capacity, or standby time, allows operators to reduce cycle times and extend the life of molecular sieves. The document presents a case study where performance testing revealed capacity would decline faster than designed. Using standby time by reducing cycle times allowed the unit to operate for longer than the planned 3 years before recharge.
The report analyzes valve failure in the 2nd stage of a compressor. Simulation shows the large cylinder size was causing high valve impact, pressure drops, and losses. Reducing the cylinder bore from 5.75" to 4.25" would significantly improve valve performance and life by lowering impact, pressure drops, and losses. Modifying the cylinders would also increase suction pressure, reduce power requirements by 1,057 HP (26%), and lower costs compared to replacing cylinders and valves.
IRJET- A Review on Improving Performance and Development of Two Stage Recipro...IRJET Journal
This document reviews improving the performance of two-stage reciprocating air compressors. It discusses how parameters like clearance between head and piston, stroke length, friction losses, runtime, background working conditions, and air leakage can impact compressor performance. The effects of these parameters are compared to baseline performance conditions. Optimal timing for starting each compressor stage is also examined. The results provide insights that can help optimize compressor design parameters and efficiency.
Generation of Air Swirl through Inlet Poppet Valve Modification and To Enhanc...iosrjce
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
The document summarizes research into modifying inlet poppet valves on a diesel engine to generate air swirl and improve combustion efficiency. Three modified valve designs were simulated using CFD: 1) 5 straight grooves on the valve head, 2) 3 masks and 3 straight grooves, and 3) 5 straight grooves with 3 fins. CFD analysis found the 5-grooved and 5-grooved with 3-fin designs generated the highest swirl ratios and turbulent kinetic energy. Physical models of these designs were then tested on a single cylinder diesel engine, finding improvements in brake thermal efficiency up to 36.9%, reductions in specific fuel consumption and exhaust emissions of CO and HC compared to the base valve design.
1. The document describes an experiment to calculate the loss coefficient (K) for different pipe components, including pipe bends, branches, and changes in cross-section.
2. Tests were conducted to measure the minor losses through pipe elbows at various angles, double elbows, and a single elbow.
3. The loss coefficients were calculated based on measurements of pressure difference, flow velocity, and component geometry. Loss coefficients ranged from 0.548 to 2.345 depending on the pipe component.
Variable Speed Drives for Gas compressor OperationsVijay Sarathy
To understand the effects of Variable Speed Drive (VSD) and Fixed Speed Drive (FSD) mode of operation on gas compressor start-up, a case study is made.
Air flow and charge motion study of engine intake portTunAnh309
1) A study was conducted using CFD to simulate experimental flow bench tests of an engine intake port design. CFD simulations were run at different valve lifts to calculate air flow rate and emulate the flow bench.
2) Flow coefficient and swirl ratio results from CFD showed good agreement with experimental flow bench measurements, though CFD overpredicted swirl ratio, especially at lower lifts.
3) CFD provides additional insight into flow patterns and velocities not obtainable from flow bench testing alone, allowing designers to more efficiently evaluate intake port designs.
The document discusses gas exchange processes in internal combustion engines. It covers topics like supercharging, turbocharging, scavenging processes, compressors, turbines, and factors that influence the residual gas fraction. It provides details on different scavenging configurations for 2-stroke engines and the intake and exhaust processes in a 4-stroke engine. Diagrams are included to illustrate the various concepts.
A computer simulation of compressor valve dynamics can help improve performance and reduce costs. The simulation solves issues like broken plates and springs by optimizing valve lift and type. This leads to longer valve life, reduced horsepower needs, increased capacity, and lower rod loads and discharge temperatures. The simulation allows testing different configurations to find the best balance of efficiency and lifespan.
CFD Analysis on theEect of Intake Valve Design on the In-Cylinder Flow.pptxameeraffan97
This document summarizes a CFD analysis on the effect of intake valve design on in-cylinder flow. The study aims to determine the swirl air flow strength inside the cylinder during intake stroke by modifying conventional intake valves with blades using SOLIDWORKS. Previous studies showed that enhancing swirl flow improves combustion and engine performance by promoting air-fuel mixing. The document reviews various intake valve and manifold designs that generated swirl, and their effects on parameters like pressure, velocity and emissions. It also defines key terms like swirl, valves and combustion chamber.
This document summarizes a numerical analysis of the flow through a mixed flow compressor stage designed for a small gas turbine engine. The analysis found that the stage achieved a total pressure ratio of 4.3 and isentropic efficiency of 73.85% at its design speed, lower than the targeted values of 5 and 80% respectively. Reasons for the lower performance include higher than expected flow angles and Mach numbers at the impeller inlet causing shocks, as well as flow separation in the diffuser due to its high curvature. Modifications to the geometry are recommended to improve the stage's performance and stability.
This document summarizes the development of piston rod seals for Stirling engines in Sweden over the past 40 years. It describes how earlier Stirling engines operated at near-atmospheric pressures but modern designs require pressures of 10-20 MPa. This necessitates a rod seal between the high-pressure working space and low-pressure crankcase. Early Swedish designs included the "Leningrader" and "Pumping Leningrader" seals, which Cleanergy still uses. The document outlines Cleanergy's efforts to analyze operating conditions, improve materials, and increase seal service life from the original 1980s design. Measurements of pressure, temperature, and friction help characterize the environment and guide simulations. The goal is to
The document provides explanations of various components of internal combustion engines including connecting rods, crankshafts, piston rings, glow plugs and camshafts. It also lists differences between SI and CI engines and discusses factors that affect engine performance such as compression ratio, thermal efficiency, valve timing and residual gas fraction.
This document compares screw compressor and centrifugal compressor options for a chlorine gas compressor. Centrifugal compressors generally have higher efficiencies but lower turndown capability compared to screw compressors. For this application, a centrifugal compressor could provide annual electricity savings of $147,000 due to its lower power requirement. However, screw compressors are better suited if large swings in gas composition are expected, as centrifugal performance is more sensitive to changes in gas properties. Maintenance is easier for options with vertically-split casings. The document provides detailed technical considerations and specifications from multiple compressor vendors for each compressor type.
The document discusses thermodynamic optimization of screw compressors. It describes using a numerical model of fluid flow and thermodynamic processes combined with a rotor profile generation algorithm to optimize a screw compressor design for a given application and fluid. Some key points:
- The optimization considers variables like rotor profile, compressor speed, oil flow rate, temperature to maximize efficiency and minimize size depending on the compressed gas/vapor and whether the compressor is oil-free or oil-flooded.
- A constrained simplex method called the Box complex method is used to find local minima which are then used to estimate a global minimum.
- The numerical model solves conservation equations for properties like internal energy and mass flow using a Runge
This document discusses hydraulic pumps, including:
- Pumps are not continuous flow devices and have discrete chambers that collect and discharge flow through valve plates. The design of these components affects pressure variation.
- Actual pump flow is determined by displacement, speed, efficiency terms accounting for volumetric (leakage) efficiency and mechanical (friction loss) efficiency.
- Volumetric efficiency depends on manufacturing tolerances while mechanical efficiency depends on bearing friction and fluid turbulence.
- Formulas are provided to calculate theoretical flow, actual flow accounting for efficiencies, torque required to drive the pump, and power delivered versus power input accounting for overall efficiency.
- Factors like fluid properties, speed, foreign particles,
1. EXPERIENCES WITH SIMULATION OF RECIPROCATING COMPRESSOR VALVE
DYNAMICS
Brian Howes, M.Sc., P.Eng.
Leonard Lin, M.Sc.M.E. Val Zacharias, M.A.
Beta Machinery Analysis Ltd.
Calgary, Canada
ABSTRACT
Experience with compressor valve modelling has
shown that reciprocating compressor performance can
sometimes be improved by subtle changes in valve
design. Modelling has led to a better understanding of
the physical behaviour of valves and of the
compression process. Three compressor valve studies
presented here demonstrate the benefits of valve
modelling.
Case 1 challenges the commonly held assumption that
reducing the lift of a compressor valve will reduce the
efficiency of the compressor. The capacity of this
compressor is increased by reducing the valve lift. A
plot of BHP/MMSCFD versus valve lift shows an
inflection point that assists the analyst in optimizing
the design.
Case 1 also presents a method of calculating the
economic effect of improvements in valve
performance.
Case 2 demonstrates the effect of inadequate flow area
through the valve. Pressure in the clearance volume
cannot decrease fast enough if flow areas are
inadequate; the result is late valve closure, and
therefore decreased valve life.
Case 3 shows the importance of considering the design
of the cylinder casting in addition to that of the valves.
Here, insufficient cylinder flow area constricted gas
flow.
Since these cases were simulated, the analyst had the
opportunity to evaluate the proposed solution over the
entire range of operating conditions. He was able to
select a valve which solved the immediate problem
and be confident that it would perform adequately
throughout the specified range of conditions.
INTRODUCTION: BENEFITS OF VALVE
SIMULATION
The main advantage of valve simulation is that it
replaces trial and error as a means to solve valve
problems, and thus saves a considerable amount of
time and expense. Although trial and error has been
used successfully in some cases, it is time-consuming
and problematic. Some quantities such as valve
displacements and impact velocities are very difficult
to measure in an operating compressor. Moreover, it is
often impossible to measure results over the range of
operating conditions, or to “measure” increases in
valve life (in a timely manner) for different trials. The
use of simulation as a valve design and trouble-
shooting tool overcomes these problems.
A normal valve in a gas compressor system should last
more than one year. Short valve life results in lost
revenue as well as high valve repair costs and
potential consequential damage. Sometimes, a valve’s
efficiency is more important than its life because a
valve with high loss or leakage will directly increase
compressor horsepower and decrease compressor
capacity. Good valve design is the practical balancing
between maximum efficiency and unlimited valve life.
This paper presents the results of valve dynamics
simulation for analyzing compressor and valve
performance. The simulation was developed based on
three previous models [4,8,10]. Some of the important
ideas in the work came from manufacturers [3,6,9,12].
Case studies show how to solve valve failure and
compressor efficiency problems by reducing valve lift
or increasing valve effective flow area.
CASE STUDIES ILLUSTRATE THE USES OF COMPRESSOR VALVE SIMULATION
1
2. Case 1 -- Valve lift affects compressor performance
The Problem
Crestar Energy Inc. operates a reciprocating
compressor at its Cessford Station in Alberta. During
its first month of operation, the first stage valves failed
“several times” (75% of the time on the discharge side
and 25% on the suction side), most often with broken
outer rings (spalled patches in area of contact with
seat).
The Unit
The compressor is a six throw two stage unit with
variable volume pockets, compressing 0.6 specific
gravity natural gas from 38 psig to 370 psig. It has
three 19.5" bore cylinders in the first stage and three
13.75" bore cylinders in the second stage, with three
suction and three discharge valves per end. It is driven
by a 3,000 HP motor running at 885 rpm at full load.
The original multi-ring valves in the first stage had
0.150" lift. Detailed valve characteristics and
dimensions may be obtained from the authors on
request.
The Simulation
Valve simulation, shown in Figure A-1, indicates that
the first stage valves close prematurely, and then
rebound and close about 20 degrees after dead center.
The reversed gas flow after dead centre produces a
violent impact, which leads to premature failure and
therefore should be avoided. The simulation showed
that stiffer springs had little effect on valve late
closing, and might result in valve fluttering.
2
3. Figure A-2 shows that the closing angle can be
controlled to less than 10 degrees after dead center
(DC) if the lift is reduced to 0.080".
Although reducing lift will cause higher valve loss, the
simulation showed in this case that compressor
capacity would increase while the ratio of horsepower
to capacity (BHP/MMSCFD) stayed within an
acceptable range. This increase is because backflow
(gas reversing through the cylinder after dead centre)
is much less when the closing angle is near dead
centre.
Figure A-3 shows that a lift of 0.080" is a good
compromise between maximizing capacity and
minimizing BHP/MMSCFD. In this case, decreasing
the lift to 0.080" produces only a gradual decrease in
efficiency (BHP/MMSCFD) but significant increases
in capacity. Crestar reduced the lift and no failures
have occurred in six months.
In addition to increasing compressor capacity,
reducing lift will improve valve dynamics. Figures A-4
and A-5 indicate maximum plate impact velocities.
For the discharge side, when lift was reduced from
0.150" to 0.080", impact velocity dropped by 52 % on
the valve seat and by 25% on the valve guard.
Although the impact velocity on the seat is much less
than on the guard, the seat contact area is also much
smaller, so the stress is still significant.
The reduction in impact velocity means that reducing
lift in this case will improve valve life. A compressor
valve manufacturer [12] has reported that a valve
should be reliable for about 109
cycles. That is, if a
compressor runs constantly at 885 RPM, its valves
should last more than one year. Svenzon [11] showed
that the number of cycles to failure will increase as the
impact velocity decreases.
This case shows that wide variations in both valve life
3
4. and performance are associated with variations in lift.
Valve simulation helps identify an optiumum balance
among the various factors; precise installation and
adjustment is also important.
Economic Effect of Valve Improvement
Savings can be made in two areas: improved capacity
(and therefore sales) and reduced cost of parts and
labour. Figure A-6 compares horsepower and capacity,
assuming that the company can sell all the gas it can
produce, that the cost of sales gas equals the cost of
fuel gas, and that the driver has some excess
horsepower.
In this case, improved valve performance increases
capacity, horsepower and also BHP/MM.
Ignoring factors which do not change with lift, such as
wages, then
income ($/yr) = [P Q (365 - t f)]
and
expenses ($/yr) per end due to repairs and fuel
= [ P C Q B (365 -t f)] + Z f
..where..
P = gas selling price ($)
C = fuel consumption rate ( MMSCF/BHP-day)
Z = valve repair cost ($)
B = BHP/MMSCFD
Q = capacity (MMSCFD)
f = frequency of repairs per year
t = days lost due to a valve change.
For this example, lift is initially set at 0.150", and then
is reduced to 0.080". Assume
P = $1.30 per MSCF = $1300 per MMSCF
C = .2 MMSCF/BHP-day, based on
35% thermal efficiency,
85% mechanical efficiency and
1000 BTU/SCF
Z = [$100(parts) + $100 (labour)]/ each cylinder
end
f = 12/year if lift is 0.150" and 1 if lift is 0.080"
t = 1/3 day
Q and B for the different lifts are shown in Table A-
1.
Table A-1. Predicted Cylinder Performance
Lift Q per end B per end
0.150" 3.61 56.0
0.080" 3.76 57.6
Table A-2. Valve Economics for 6 Ends
Lift Income Expenses
0.150" $10,165,038/
yr-stage
$128,248/
yr-stage
0.080" $10,704,720/
yr-stage
$124,180/
yr-stage
Benefit $539,682 $4,067
4
5. Table A-2 and Figure A-7 show income and expenses
for two lifts, for six cylinder ends. Income is higher
and operations and maintenance costs are slightly
lower when lift is 0.080". Actual profit must be
calculated taking into account wages and all other
costs. Profit also varies depending on whether or not a
valve retrofit is required. These figures highlight the
differences that can be achieved when valves are
designed appropriately.
Case 2 -- Valve Losses Affect Valve Life
The Problem
The purpose of this study was to determine the cause
of and solutions to premature valve failures in a
compressor unit in which the valves had been failing
approximately every 3 weeks for a period of 18
months.
The owner wanted to find the cause of the failure, and
also to evaluate the performance of valves with
different designs, specifically a two port valve from
one manufacturer and a four port valve from another.
The Unit
The compressor has four throws and three stages, and
compresses gas from 170 psig to 920 psig.
The third stage has one cylinder with 6.5" bore × 6.0"
stroke running at 991 rpm and compressing natural
gas of 0.7 specific gravity. Two 4.25" mass damping
valves (four port type) were installed on the third stage
head end suction and discharge during the
measurement.
The Simulation
Figure B-1 shows the measured and predicted head
end pressure-volume (PV) diagrams for the third stage
of the compressor. The measured curve is for the four
port type; the predicted curves are for the four port
type, the two port type, and a cylinder modified to
hold extra valves. The measured and predicted curves
for the four port type coincide very well; minor
discrepancies are likely due to measurement error or
the effect of pulsation.
Figure B-1 shows that the four port valve has less
valve loss than the two port valve, and is therefore
preferable. However, valve loss is excessive for both
types.
The simulation found that the maximum pressure drop
even across the four port valve was as high as 18% of
absolute line pressure for suction, and 22% for
discharge. Normal values are about 6%.
The conclusion: the valves failed due to the high valve
losses and pressure drops, which cause very late valve
closure and thus very high impacts. Reducing valve
lift would not have solved this problem; it would have
increased valve loss and therefore made valve
performance worse.
Solutions
The recommendation was to increase the valve
effective flow area. One approach is to install a
different cylinder, designed to hold one or two extra
suction and discharge valves for each end. Figure B-1
shows that the average valve loss with two extra valves
installed would be 7%, compared to the original
average valve loss of 20% in the four port valve case.
Figure B-2 compares the impact velocity for the
different cases. Installing the extra valves, and
therefore doubling the flow areas, makes a dramatic
improvement.
This case indicates that valve simulation can help
manufacturers improve their compressor and valve
design so that compressor users can obtain optimum
performance.
5
6. Case 3 -- Insufficient Cylinder Flow Area Constricts Gas Flow
Problem
NGTL’s Princess Compressor Station, in Alberta, has
a compressor which in the past experienced occasional
valve failures. Damaged valves, for this unit, were
characterized by two or three broken poppets and
sporadically broken poppet springs. The frequency of
valve failures depended on flow conditions and
compressor operating regimes.
The worst failure frequency was observed when certain
valves were damaged almost monthly, requiring
immediate repairs. Since the unit has 24 identical
suction and 24 similar discharge double deck poppet
valves, each with 30 plastic poppets, the potential for
down-time was high. To prevent further failures, the
following valve study was launched.
The Unit
The compressor is a one stage, double-acting unit with
variable volume pockets. It has four 17.5" cylinders
and a 19" stroke. It is driven by a 6,000 HP integral
engine running at 300 rpm and compressing 0.6 SG
pipeline natural gas from 630 psig to 790 psig.
The Simulation
Figure C-1 compares three PV diagrams in a head end
cylinder: measured, simulated with valve pocket and
simulated without pocket. The predicted PV curve is
much closer to the measured curve if the simulation
considers valve pocket loss (which is defined as the
pressure drop between the valve and cylinder bore).
Cheema [2] has reported that in some cases the
resistance offered to flow by the cylinder casting can
be equal to the resistance offered by the valves.
Constricted flow areas adjacent to a valve contribute a
significant amount of pressure loss because they
impose changes in velocity and direction.
Figure C-2 indicates the installation of the valve in the
compressor. Dimension a = 0.3" and b = 0.5". These
distances, which are influenced by the thickness of the
valve yokes, are too small; the valve pocket loss factor
was calculated to be between 1.9 and 2.4. Therefore,
flow resistance and pressure loss are high [1].
The simulated valve motions shown in Figure C-3
indicate that the valves flutter in the originally
modelled operating condition. During a valve opening
event, a good valve should be fully open more than
70% of its open period. If the forward gas force is not
strong enough to push the plate against its guard, the
valve will flutter. This is harmful to valve life because
it increases the number of impacts. Valve flutter
occurs when valve flow area is too large or springs are
too stiff.
500
600
700
800
900
0 20 40 60 80 100
measured
valve loss only
pocket included
Ps
Pd
Percent Swept Volume
CylinderPressure(psig)
Fig. C-1 Comparison of PV for 3H, NOVA PRINCESS UNIT4A
6
7. The recommendations based on the above simulation
results were:
1. Reduce valve lift from 0.28" to 0.15" to stop valve
fluttering.
2. Increase yoke thickness so that the valve pocket
flow area has less resistance.
3. Pressure tap the valve caps so that future
measurements will exclude the effect of pulsation.
Recommendation 1 will reduce valve flow area,
increase gas force on the poppet, and keep the poppet
against its guard most of the time.
Recommendation 2 will reduce the total horsepower
consumed by the valve by about 18%. Table C-1 shows
the total horsepower consumed by the original and
modified valves.
Table C-1. Comparison of Indicated HP - Cylinder 3
Original
HP
HP-Rec. 1
Reduced lift
HP - Rec. 2
Increased yoke
Head End 375 385 312
Crank End 478 496 387
Totals 853 881 699
Fuel cost can be calculated based on Table C-1. The
difference between cylinder horsepower with and
without valve pocket loss is 154 hp for cylinder 3; for
the four cylinder unit, the total difference is 616 HP.
Using a range of values from 20 to 80 cents per
horsepower per day, the fuel cost wasted on the valve
pocket loss is about $45,000 to $180,000 per year.
This case shows that cylinder flow area should be
considered during valve modelling, especially if the
model does not otherwise coincide with field
measurements. Accurate valve modelling can be useful
not only for valve trouble-shooting but also for saving
fuel costs.
CONCLUSIONS
Efficient performance and reasonable valve life
demands optimum valve design. Valves in a
compressor can work optimally only in a small range
of operating conditions (gas composition, temperature,
suction and discharge pressure, etc.) If such conditions
are changed, the valve flow area, springs and lift must
be reconsidered in order to keep the compressor and
valves working well.
Some manufacturers use a comparison method to
choose valves. They may assume that if a valve
worked successfully in one case, then the same valve
should work well in a similar case. This assumption is
not necessarily accurate, since valve performance is
affected by so many variables.
This valve simulation accurately accounts for valve
losses due to back flow, because it predicts real mass
flows across valves (instead of assuming zero at dead
centers). Therefore, it predicts compressor capacity,
horsepower and rod load more accurately than
traditional methods [5,7].
Computerized valve performance analysis, in the
hands of an experienced analyst, is a tool that enables
precise specification of valves for any combination of
conditions. A valve dynamics simulation can give
valuable information about valve losses, valve opening
and closing angles and impact velocities.
Ultimately, simulation can enable optimum designs for
maximizing profit.
7
8. ADDITIONAL WORK
The economics of valve improvement appear to vary
depending on whether the company can sell all the gas
it can produce, and on whether the engine has excess
capacity. This is an important area for further
research.
ACKNOWLEDGMENTS
The authors are very grateful to Dr. R.J. Rogers and
Dr. G. Holloway of the University of New Brunswick
for their guidance in the mathematical models and for
the experiment to verify gas flow and force models in
the simulation.
The authors wish to acknowledge the following
organizations for their support and permission to
publish the results: Crestar Energy Inc. and NGTL
(NOVA Gas Transmission Ltd.) Facility Provision
Platforms (Mechanical & Materials Engineering).
REFERENCES
1. Bauer, F. 1988 Proceedings of International
Compressor Engineering Conference at
Purdue. Valve Losses in Reciprocating
Compressor.
2 . Cheema, Gurmeet S. & McDonald, Kriss
1993 "Measurement of Internal Cylinder
Equivalent Flow Areas and Effect of Piston
Masking of Valves", 8th International
Reciprocating Machinery Conference,
Technical Paper No. 2, Denver, Colorado,
Sept. 20-23, 1993.
3. Davis, H. 1970 Industrial Reciprocating and
Rotary Compressor Design and Operation
Problems I.MECH.E. Conference, London,
Paper no. 2, 9-23. Effects of reciprocating
compressor valve design on performance and
reliability.
4. Fleming, J.S. 1983 PhD thesis, University of
Strathclyde, Scotland. Gas force effects on
compressor valves in the early stages of valve
opening.
5. Gas Processors Supplies Association. 1987
"Engineering Data Book: Volume I", 10th
edition.
6. Hoerbiger Corporation of America, Inc. 1989
Valve Theory and Design.
7. Pipeline and Compressor Research Council
1990 "Field Measurement Guidelines
Compressor Cylinder Performance
Summary", 3rd Revision.
8. Rogers, R.J. and Lu, Y. 1991 Computer
Simulation Program for Reciprocating
Compressor Valve Dynamics Department of
Mechanical Engineering, University of new
Brunswick.
9. Singh, P.J. 1984 Proceedings of Purdue
Compressor Technology Conference 129-138.
A digital reciprocating compressor simulation
program including suction and discharge
piping.
10. Soedel, W. 1972 Introduction to Computer
Simulation of Positive Displacement Type
Compressor Course notes, School of
Mechanical Engineering, Purdue University.
11. Svenzon, M. 1976 Proceedings of Purdue
Compressor Technology Conference 65-73.
Impact Fatigue of valve Steels.
12. Woollant,D. 1995 Advanced Compressor
Valves Analysis and Design Short course note
of Dresser-Rand Co., presented on 10th Gas
Machinery Conf. Corpus Christi, Texas.
THE AUTHORS
All three authors work for Beta Machinery Analysis
Ltd., which has been consulting since 1967 in the
areas of field trouble-shooting and computer
modelling for high end equipment.
Brian Howes obtained his M.Sc. in Mechanical
Engineering in 1972. His experience includes trouble-
shooting on a wide variety of high end equipment,
research and development in pulsation and vibration
of piping systems, and analysis of mechanical and
structural systems so as to ensure acceptable static
strength and dynamic response. He is Chief Engineer.
Leonard Lin received his M.Sc.ME degree in 1994.
His M.Sc. thesis was titled “Simulation of Valve
Dynamics in a Large Reciprocating Compressor.” He
is a researcher and project engineer, specializing in
valve and reciprocating machinery modelling and
analysis.
Valerie Zacharias obtained her M.A. in
Communications in 1978, and did a postgraduate year
in Computer Science in 1979. Her experience
includes acoustical modelling of reciprocating
compressors, and ten years in the predictive
maintenance business, primarily in customer service,
training, and communications. She handles Customer
Services.
8