Comprehensive investigation into historical pipeline construction costs and engineering economic analysis of Alaska in-state gas pipeline

NASA Astrophysics Data System (ADS)

Rui, Zhenhua

This study analyzes historical cost data of 412 pipelines and 220 compressor stations. On the basis of this analysis, the study also evaluates the feasibility of an Alaska in-state gas pipeline using Monte Carlo simulation techniques. Analysis of pipeline construction costs shows that component costs, shares of cost components, and learning rates for material and labor costs vary by diameter, length, volume, year, and location. Overall average learning rates for pipeline material and labor costs are 6.1% and 12.4%, respectively. Overall average cost shares for pipeline material, labor, miscellaneous, and right of way (ROW) are 31%, 40%, 23%, and 7%, respectively. Regression models are developed to estimate pipeline component costs for different lengths, cross-sectional areas, and locations. An analysis of inaccuracy in pipeline cost estimation demonstrates that the cost estimation of pipeline cost components is biased except for in the case of total costs. Overall overrun rates for pipeline material, labor, miscellaneous, ROW, and total costs are 4.9%, 22.4%, -0.9%, 9.1%, and 6.5%, respectively, and project size, capacity, diameter, location, and year of completion have different degrees of impacts on cost overruns of pipeline cost components. Analysis of compressor station costs shows that component costs, shares of cost components, and learning rates for material and labor costs vary in terms of capacity, year, and location. Average learning rates for compressor station material and labor costs are 12.1% and 7.48%, respectively. Overall average cost shares of material, labor, miscellaneous, and ROW are 50.6%, 27.2%, 21.5%, and 0.8%, respectively. Regression models are developed to estimate compressor station component costs in different capacities and locations. An investigation into inaccuracies in compressor station cost estimation demonstrates that the cost estimation for compressor stations is biased except for in the case of material costs. Overall average overrun rates for compressor station material, labor, miscellaneous, land, and total costs are 3%, 60%, 2%, -14%, and 11%, respectively, and cost overruns for cost components are influenced by location and year of completion to different degrees. Monte Carlo models are developed and simulated to evaluate the feasibility of an Alaska in-state gas pipeline by assigning triangular distribution of the values of economic parameters. Simulated results show that the construction of an Alaska in-state natural gas pipeline is feasible at three scenarios: 500 million cubic feet per day (mmcfd), 750 mmcfd, and 1000 mmcfd.

Optimal design of a gas transmission network: A case study of the Turkish natural gas pipeline network system

NASA Astrophysics Data System (ADS)

Gunes, Ersin Fatih

Turkey is located between Europe, which has increasing demand for natural gas and the geographies of Middle East, Asia and Russia, which have rich and strong natural gas supply. Because of the geographical location, Turkey has strategic importance according to energy sources. To supply this demand, a pipeline network configuration with the optimal and efficient lengths, pressures, diameters and number of compressor stations is extremely needed. Because, Turkey has a currently working and constructed network topology, obtaining an optimal configuration of the pipelines, including an optimal number of compressor stations with optimal locations, is the focus of this study. Identifying a network design with lowest costs is important because of the high maintenance and set-up costs. The quantity of compressor stations, the pipeline segments' lengths, the diameter sizes and pressures at compressor stations, are considered to be decision variables in this study. Two existing optimization models were selected and applied to the case study of Turkey. Because of the fixed cost of investment, both models are formulated as mixed integer nonlinear programs, which require branch and bound combined with the nonlinear programming solution methods. The differences between these two models are related to some factors that can affect the network system of natural gas such as wall thickness, material balance compressor isentropic head and amount of gas to be delivered. The results obtained by these two techniques are compared with each other and with the current system. Major differences between results are costs, pressures and flow rates. These solution techniques are able to find a solution with minimum cost for each model both of which are less than the current cost of the system while satisfying all the constraints on diameter, length, flow rate and pressure. These results give the big picture of an ideal configuration for the future state network for the country of Turkey.

Synthetic Minor NSR Permit: Dominion Energy Questar Pipeline, LLC - Fidlar Compressor Station

EPA Pesticide Factsheets

This page contains documents related to the synthetic minor NSR permit for the Questar Pipeline Company Fidlar Compressor Station, located on the Uintah and Ouray Indian Reservation in Uintah County, UT.

77 FR 42719 - Alliance Pipeline, L.P.; Notice of Availability of the Environmental Assessment for the Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-20

... existing Alliance mainline in Renville County; One pig \\1\\ launcher at the proposed compressor station site and one pig receiver at the pressure regulating station site; and \\1\\ A ``pig'' is a tool that is...

Synthetic Minor NSR Permit: Northern Border Pipeline Company - Compressor Station #2

EPA Pesticide Factsheets

This page contains the response to public comments and the final synthetic minor NSR permit for the Northern Border Pipeline Company Compressor Station #2, located on the Fort Peck Indian Reservation in Roosevelt County, Montana.

Fluid-structure interaction analysis and lifetime estimation of a natural gas pipeline centrifugal compressor under near-choke and near-surge conditions

NASA Astrophysics Data System (ADS)

Ju, Yaping; Liu, Hui; Yao, Ziyun; Xing, Peng; Zhang, Chuhua

2015-11-01

Up to present, there have been no studies concerning the application of fluid-structure interaction (FSI) analysis to the lifetime estimation of multi-stage centrifugal compressors under dangerous unsteady aerodynamic excitations. In this paper, computational fluid dynamics (CFD) simulations of a three-stage natural gas pipeline centrifugal compressor are performed under near-choke and near-surge conditions, and the unsteady aerodynamic pressure acting on impeller blades are obtained. Then computational structural dynamics (CSD) analysis is conducted through a one-way coupling FSI model to predict alternating stresses in impeller blades. Finally, the compressor lifetime is estimated using the nominal stress approach. The FSI results show that the impellers of latter stages suffer larger fluctuation stresses but smaller mean stresses than those at preceding stages under near-choke and near-surge conditions. The most dangerous position in the compressor is found to be located near the leading edge of the last-stage impeller blade. Compressor lifetime estimation shows that the investigated compressor can run up to 102.7 h under the near-choke condition and 200.2 h under the near-surge condition. This study is expected to provide a scientific guidance for the operation safety of natural gas pipeline centrifugal compressors.

78 FR 65639 - Questar Pipeline Company; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP14-6-000] Questar Pipeline... appurtenant facilities located in Moffat County, Colorado. Specifically, Questar proposes to abandon one Solar Saturn 1200 compressor, a compressor building, two generators and a generator building, a liquids storage...

76 FR 46285 - Columbia Gas Transmission, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-02

... transmission pipeline and an associated meter and regulation (M&R) station in Warren County, Virginia. In addition, the project involves the installation of minor station piping and appurtenance modifications at existing compressor stations in northern Virginia and eastern West Virginia, and abandonment and...

ENVIRONMENTAL TECHNOLOGY REPORT, MIRATECH CORPORATION, GECO(TM) 3001 AIR/FUEL RATIO CONTROLLER (MANUFACTURED BY WOODWARD GOVERNOR COMPANY) PHASE II REPORT

EPA Science Inventory

In the natural gas industry, transmission pipeline operators use internal combustion (IC) gas-fired engines to provide the mechanical energy needed to drive pipeline gas compressors. As such, owners and operators of compressor stations are interested in the performance of these e...

76 FR 52652 - National Fuel Gas Supply Corporation; Tennessee Gas Pipeline Company; Notice of Availability of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-23

... gas-fired turbines for compressor units A2 and A3 and restaging of centrifugal compressors for units.... CP11-133-000] National Fuel Gas Supply Corporation; Tennessee Gas Pipeline Company; Notice of... assessment (EA) for National Fuel Gas Supply Corporation's (National Fuel) proposed Northern Access Project...

49 CFR 192.171 - Compressor stations: Additional safety equipment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Compressor stations: Additional safety equipment... Pipeline Components § 192.171 Compressor stations: Additional safety equipment. (a) Each compressor station must have adequate fire protection facilities. If fire pumps are a part of these facilities, their...

49 CFR 192.163 - Compressor stations: Design and construction.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of... building. Except for a compressor building on a platform located offshore or in inland navigable waters, each main compressor building of a compressor station must be located on property under the control of...

Axial inlet conversion to a centrifugal compressor with magnetic bearings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novecosky, T.

1994-01-01

NOVA's Alberta Gas Transmission Division transports natural gas via pipeline throughout the province of Alberta, Canada, exporting it to eastern Canada, US, and British Columbia. There is a continuing effort to operate the facilities and pipeline at the highest possible efficiency. One area being addressed to improve efficiency is compression of the gas. By improving compressor efficiency, fuel consumption and hence operating costs can be reduced. One method of improving compressor efficiency is by converting the compressor to an axial inlet configuration, a conversion that has been carried out more frequently in the past years. Concurrently, conventional hydrodynamic bearings havemore » been replaced with magnetic bearings on many centrifugal compressors. This paper discusses the design and installation for converting a radial overhung unit to an axial inlet configuration, having both magnetic bearings and a thrust reducer. The thrust reducer is required to reduce axial compressor shaft loads, to a level that allows the practical installation of magnetic bearings within the space limitations of the compressor (Bear and Gibson, 1992).« less

76 FR 69717 - Natural Gas Pipeline Company of America, LLC; Notice of Intent To Prepare an Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-09

... proposed Project would consist of the following: Compressor Station 205--Washington County, Iowa Construct and operate a new 3,550 hp gas-fired compressor unit at Natural's Compressor Station 205 located near... Natural's Compressor Station 205. Install new 10-inch-diameter meter. [[Page 69718

77 FR 14010 - Millennium Pipeline Company, LLC; Notice of Availability of the Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

... emergency electrical power generator. Pipeline facilities required for the project include approximately 545 feet of new 36-inch- diameter suction and discharge pipelines which would connect the compressor... pipeline located between the new suction and discharge pipelines. The FERC staff mailed copies of the EA to...

Mathematical modeling of non-stationary gas flow in gas pipeline

NASA Astrophysics Data System (ADS)

Fetisov, V. G.; Nikolaev, A. K.; Lykov, Y. V.; Duchnevich, L. N.

2018-03-01

An analysis of the operation of the gas transportation system shows that for a considerable part of time pipelines operate in an unsettled regime of gas movement. Its pressure and flow rate vary along the length of pipeline and over time as a result of uneven consumption and selection, switching on and off compressor units, shutting off stop valves, emergence of emergency leaks. The operational management of such regimes is associated with difficulty of reconciling the operating modes of individual sections of gas pipeline with each other, as well as with compressor stations. Determining the grounds that cause change in the operating mode of the pipeline system and revealing patterns of these changes determine the choice of its parameters. Therefore, knowledge of the laws of changing the main technological parameters of gas pumping through pipelines in conditions of non-stationary motion is of great importance for practice.

77 FR 70429 - Gulf South Pipeline Company, LP; Notice of Intent To Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

... compressor stations in Mississippi and Alabama. The SEME Project would provide about 450 million standard... station, five mainline valves, two pig \\1\\ launchers, two pig receivers, and overpressure protection... three new compressor stations, including: [ssquf] The Forrest Compressor Station, which would be located...

49 CFR 192.735 - Compressor stations: Storage of combustible materials.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance... buildings, must be stored a safe distance from the compressor building. (b) Aboveground oil or gasoline...

78 FR 26352 - Gulf South Pipeline Company, LP; Supplemental Notice of Intent To Prepare an Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-06

... change in location of the Moss Point Compressor Station made after the initial scoping period. This... South would construct 3 new compressor stations located in Forrest County, Jasper County, and Jackson... about 2,000 feet to the south; and A change in location of the Moss Point Compressor Station site from...

Argentine gas system underway for Gas del Estado

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bosch, H.

Gas del Estado's giant 1074-mile Centro-Oeste pipeline project - designed to ultimately transport over 350 million CF/day of natural gas from the Neuquen basin to the Campo Duran-Buenos Aires pipeline system - is now underway. The COGASCO consortium of Dutch and Argentine companies awarded the construction project will also operate and maintain the system for 15 years after its completion. In addition to the 30-in. pipelines, the agreement calls for a major compressor station at the gas field, three intermediate compressor stations, a gas-treatment plant, liquids-recovery facilities, and the metering, control, communications, and maintenance equipment for the system. Fabricated inmore » Holland, the internally and externally coated pipe will be double-jointed to 80-ft lengths after shipment to Argentina; welders will use conventional manual-arc techniques to weld the pipeline in the field.« less

76 FR 537 - Eurasian Oil and Gas Suppliers Mission to Almaty, Kazakhstan Ankara and Istanbul Turkey

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-05

... gas drilling and production equipment and services; Turbines, compressors and pumps for pipeline...,300 km NABUCCO natural gas pipeline will link Caspian and Middle Eastern suppliers through Turkey to... Interconnector (ITGI) and Trans Adriatic Pipeline (TAP). In addition to oil and gas exploration and production...

77 FR 3763 - Questar Pipeline Company; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-25

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-43-000] Questar... application pursuant to sections 157.205, 157.208 and 157.210 of the Federal Energy Regulatory Commission's...-000, to construct, own and operate the upgraded compressor engine at the Blind Canyon Compressor...

49 CFR 192.171 - Compressor stations: Additional safety equipment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of... must have adequate fire protection facilities. If fire pumps are a part of these facilities, their... event of inadequate cooling or lubrication of the unit. (d) Each compressor station gas engine that...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, C. LEE COOK DIV., DOVER CORP., STATIC PAC SYSTEM, PHASE I REPORT

EPA Science Inventory

The Static Pac was verified at a natural gas compressor station operated by ANR Pipeline Company. The test was carried out on two engines (8-cylinder, 2000 hp), each with two reciprocating compressors operating in parallel (4 in. rods). The evaluation focused on two shutdown proc...

Monitoring of energy efficiency of technological modes of gas transport using modern gas-turbine equipment

NASA Astrophysics Data System (ADS)

Golik, V. V.; Zemenkova, M. Yu; Shipovalov, A. N.; Akulov, K. A.

2018-05-01

The paper presents calculations and an example of energy efficiency justification of the regimes of the equipment used. The engineering design of the gas pipeline in the part of monitoring the energy efficiency of a gas compressor unit (GCU) is considered. The results of the GCU characteristics and its components evaluation are described. The evaluation results of the energy efficiency indicators of the gas pipeline are presented. As an example of the result of the analysis, it is proposed to use gas compressor unit GCU-32 "Ladoga" because of its efficiency and cost effectiveness, in comparison with analogues.

78 FR 14787 - Millennium Pipeline Company, L.L.C.; Notice of Availability of the Environmental Assessment for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-07

... quality of the human environment. The U.S. Environmental Protection Agency participated as a cooperating... with respect to resources potentially affected by the proposal and participate in the NEPA analysis... natural gas-fired compressor unit at the new Hancock Compressor Station; About 320 feet of 30-inch...

78 FR 13663 - Southern Star Central Gas Pipeline, Inc.; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-28

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-76-000] Southern Star..., 2013, Southern Star Central Gas Pipeline, Inc. (Southern Star), 4700 Highway 56, P.O. Box 20010... public inspection. Specifically, Southern Star proposes to construct a new compressor site gas and...

Magnetic bearing design and control optimization for a four-stage centrifugal compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinckney, F.D.; Keesee, J.M.

1992-07-01

A four-stage centrifugal pipeline compressor with a flexible rotor was equipped with magnetic bearings. Magnetic bearing sizing, shaft rotor dynamics, and controller/bearing design are discussed. Controller changes during shop and field tuning and the resulting rotor dynamic effects are also presented. Results of the field operation of this compressor indicate no vibration-related problems, despite the shaft second and third undamped modes being within the operating speed range. During the first 14 months after field commissioning, 9900 operating hours had been accumulated, indicating a 97 percent unit availability. 6 refs.

Novel concepts for the compression of large volumes of carbon dioxide-phase III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, J. Jeffrey; Allison, Timothy C.; Evans, Neal D.

In the effort to reduce the release of CO 2 greenhouse gases to the atmosphere, sequestration of CO 2 from Integrated Gasification Combined Cycle (IGCC) and Oxy-Fuel power plants is being pursued. This approach, however, requires significant compression power to boost the pressure to typical pipeline levels. The penalty can be as high as 8-12% on a typical IGCC plant. The goal of this research is to reduce this penalty through novel compression concepts and integration with existing IGCC processes. The primary objective of the study of novel CO 2 compression concepts is to reliably boost the pressure of COmore » 2 to pipeline pressures with the minimal amount of energy required. Fundamental thermodynamics were studied to explore pressure rise in both liquid and gaseous states. For gaseous compression, the project investigated novel methods to compress CO 2 while removing the heat of compression internal to the compressor. The highpressure ratio, due to the delivery pressure of the CO 2 for enhanced oil recovery, results in significant heat of compression. Since less energy is required to boost the pressure of a cooler gas stream, both upstream and inter-stage cooling is desirable. While isothermal compression has been utilized in some services, it has not been optimized for the IGCC environment. Phase I of this project determined the optimum compressor configuration and developed technology concepts for internal heat removal. Other compression options using liquefied CO 2 and cryogenic pumping were explored as well. Preliminary analysis indicated up to a 35% reduction in power is possible with the new concepts being considered. In the Phase II program, two experimental test rigs were developed to investigate the two concepts further. A new pump loop facility was constructed to qualify a cryogenic turbopump for use on liquid CO 2 . Also, an internally cooled compressor diaphragm was developed and tested in a closed loop compressor facility using CO 2 . Both test programs successfully demonstrated good performance and mechanical behavior. In Phase III, a pilot compression plant consisting of a multi-stage centrifugal compressor with cooled diaphragm technology has been designed, constructed, and tested. Comparative testing of adiabatic and cooled tests at equivalent inlet conditions shows that the cooled diaphragms reduce power consumption by 3-8% when the compressor is operated as a back-to-back unit and by up to 9% when operated as a straight-though compressor with no intercooler. The power savings, heat exchanger effectiveness, and temperature drops for the cooled diaphragm were all slightly higher than predicted values but showed the same trends.« less

78 FR 55072 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-09

... Project Transco proposes to add a new compressor unit to its existing Compressor Station 85 in Choctaw County, Alabama and up-rate an existing compressor unit at its existing Compressor Station 83 in Mobile... 225,000 dekatherms per day (dth/d) from Compressor Station 85 Receipt Points southward to the...

NALE-IT

EPA Pesticide Factsheets

Technical product bulletin: this surface washing agent for oil spill cleanups is applied by pressure sprayer to pit closures, surface hydrocarbon spills, compressor stations, pipeline and flow line leaks, well head and tank farm leaks, and highway spills

78 FR 42062 - Columbia Gas Transmission, LLC; Notice of Intent to Prepare an Environmental Assessment and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-15

... facilities: New compressor station (Redd Farm Compressor Station) on Columbia's existing Line 1570 in... setting; Modifications to the Smithfield Compressor Station consisting of upgrades to the existing... coolers; Modifications to the Glenville Compressor Station by installing two gas-fired turbines, each...

75 FR 5312 - ETC Tiger Pipeline Company, LLC; Notice of Availability of the Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-02

... quality of the human environment. This EA was prepared in cooperation with U.S. Army Corps of Engineers, U... Three pig launcher/receiver facilities associated with the Carthage and Bienville Compressor Stations...

75 FR 51455 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-20

... loops,\\1\\ construct one new compressor station, add compression at two existing compressor stations, and perform other modifications to five compressor stations. The MSEP would provide about 451 million standard... Mobile Bay Lateral, down to existing Compressor Station 85. According to Transco, its project would...

76 FR 13177 - Questar Pipeline Company; Notice of Availability of the Environmental Assessment for the Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-10

... constitute a major federal action significantly affecting the quality of the human environment. The U.S... mileposts (MP) 8.5, 14.5, and 24.6; One pig launcher/receiver at the Fidlar Compressor Station; Eight...

Organic Rankine Cycle for Residual Heat to Power Conversion in Natural Gas Compressor Station. Part I: Modelling and Optimisation Framework

NASA Astrophysics Data System (ADS)

Chaczykowski, Maciej

2016-06-01

Basic organic Rankine cycle (ORC), and two variants of regenerative ORC have been considered for the recovery of exhaust heat from natural gas compressor station. The modelling framework for ORC systems has been presented and the optimisation of the systems was carried out with turbine power output as the variable to be maximized. The determination of ORC system design parameters was accomplished by means of the genetic algorithm. The study was aimed at estimating the thermodynamic potential of different ORC configurations with several working fluids employed. The first part of this paper describes the ORC equipment models which are employed to build a NLP formulation to tackle design problems representative for waste energy recovery on gas turbines driving natural gas pipeline compressors.

29 CFR 1910.402 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... performing any tasks usually associated with commercial diving such as: Placing or removing heavy objects underwater; inspection of pipelines and similar objects; construction; demolition; cutting or welding; or the... pressure vessel connected to the outlet of a compressor and used as an air reservoir. Working pressure: The...

Centrifugal compressor surge detecting method based on wavelet analysis of unsteady pressure fluctuations in typical stages

NASA Astrophysics Data System (ADS)

Izmaylov, R.; Lebedev, A.

2015-08-01

Centrifugal compressors are complex energy equipment. Automotive control and protection system should meet the requirements: of operation reliability and durability. In turbocompressors there are at least two dangerous areas: surge and rotating stall. Antisurge protecting systems usually use parametric or feature methods. As a rule industrial system are parametric. The main disadvantages of anti-surge parametric systems are difficulties in mass flow measurements in natural gas pipeline compressor. The principal idea of feature method is based on the experimental fact: as a rule just before the onset of surge rotating or precursor stall established in compressor. In this case the problem consists in detecting of unsteady pressure or velocity fluctuations characteristic signals. Wavelet analysis is the best method for detecting onset of rotating stall in spite of high level of spurious signals (rotating wakes, turbulence, etc.). This method is compatible with state of the art DSP systems of industrial control. Examples of wavelet analysis application for detecting onset of rotating stall in typical stages centrifugal compressor are presented. Experimental investigations include unsteady pressure measurement and sophisticated data acquisition system. Wavelet transforms used biorthogonal wavelets in Mathlab systems.

76 FR 24473 - Transwestern Pipeline Company, LLC; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-02

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP11-191-000] Transwestern...,000 HP reciprocating gas engines, compressors, and ancillary facilities (Project Facilities) at its... to access the document. For assistance, contact FERC at [email protected] or call toll-free...

76 FR 56191 - Notice of Application; ANR Pipeline Company

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-12

... Project (MRP), comprised of a new 6,300 horsepower compressor station in Portage County, Wisconsin, all as... TTY, (202) 502-8659. Located in Portage County, Wisconsin, north of Stevens Point, Wisconsin, the MRP... service commitments of ANR's shippers in Wisconsin. ANR states that the MRP will increase the reliability...

76 FR 1146 - Notice of Intent To Prepare an Environmental Assessment for the Proposed Northeast Supply...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-07

... meter station and compressor station, and other appurtenant facilities. The Northeast Supply... modifications at existing Compressor Station 230C in Niagara County, New York; A new pig \\2\\ receiver at existing Compressor Station 317 in Bradford County, Pennsylvania; \\2\\ A ``pig'' is a tool that is inserted...

Helium compressors for closed-cycle, 4.5-Kelvin refrigerators

NASA Technical Reports Server (NTRS)

Hanson, T. R.

1992-01-01

An improved helium compressor for traveling-wave maser and closed-cycle refrigerator systems was developed and is currently being supplied to the DSN. This new 5-hp compressor package is designed to replace the current 3-hp DSN compressors. The new compressor package was designed to retrofit into the existing 3-hp compressor frame and reuse many of the same components, therefore saving the cost of documenting and fabricating these components when implementing a new 5-hp compressor.

76 FR 18751 - National Fuel Gas Supply Corporation; Tennessee Gas Pipeline Company; Notice of Intent To Prepare...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-05

... Prepare an Environmental Assessment for the Proposed Northern Access Project and Station 230c Project... County, Pennsylvania. TGP's Station 230C Project would involve construction and operation of facilities... conduct two onsite environmental reviews of National Fuel's proposed East Aurora Compressor Station site...

77 FR 58824 - Gulf Shore Energy Partners, LP; Notice of Intent To Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-24

... Booster Station Project and Request for Comments on Environmental Issues The staff of the Federal Energy... the environmental impacts of the Markham Booster Station Project involving construction and operation... operate a booster compressor station. The pipeline segment currently interconnects with the systems of...

Optimal Energy Consumption Analysis of Natural Gas Pipeline

PubMed Central

Liu, Enbin; Li, Changjun; Yang, Yi

2014-01-01

There are many compressor stations along long-distance natural gas pipelines. Natural gas can be transported using different boot programs and import pressures, combined with temperature control parameters. Moreover, different transport methods have correspondingly different energy consumptions. At present, the operating parameters of many pipelines are determined empirically by dispatchers, resulting in high energy consumption. This practice does not abide by energy reduction policies. Therefore, based on a full understanding of the actual needs of pipeline companies, we introduce production unit consumption indicators to establish an objective function for achieving the goal of lowering energy consumption. By using a dynamic programming method for solving the model and preparing calculation software, we can ensure that the solution process is quick and efficient. Using established optimization methods, we analyzed the energy savings for the XQ gas pipeline. By optimizing the boot program, the import station pressure, and the temperature parameters, we achieved the optimal energy consumption. By comparison with the measured energy consumption, the pipeline now has the potential to reduce energy consumption by 11 to 16 percent. PMID:24955410

77 FR 71585 - Eastern Shore Natural Gas Company; Notice of Intent To Prepare an Environmental Assessment for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-03

... Compressor Station Upgrade Project and Request for Comments on Environmental Issues The staff of the Federal... discuss the environmental impacts of the Daleville Compressor Station Upgrade Project (Project) involving... compressor engines at its existing Daleville Compressor Station in Chester County, Pennsylvania. One...

Pipeline bottoming cycle study. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-06-01

The technical and economic feasibility of applying bottoming cycles to the prime movers that drive the compressors of natural gas pipelines was studied. These bottoming cycles convert some of the waste heat from the exhaust gas of the prime movers into shaft power and conserve gas. Three typical compressor station sites were selected, each on a different pipeline. Although the prime movers were different, they were similar enough in exhaust gas flow rate and temperature that a single bottoming cycle system could be designed, with some modifications, for all three sites. Preliminary design included selection of the bottoming cycle workingmore » fluid, optimization of the cycle, and design of the components, such as turbine, vapor generator and condensers. Installation drawings were made and hardware and installation costs were estimated. The results of the economic assessment of retrofitting bottoming cycle systems on the three selected sites indicated that profitability was strongly dependent upon the site-specific installation costs, how the energy was used and the yearly utilization of the apparatus. The study indicated that the bottoming cycles are a competitive investment alternative for certain applications for the pipeline industry. Bottoming cycles are technically feasible. It was concluded that proper design and operating practices would reduce the environmental and safety hazards to acceptable levels. The amount of gas that could be saved through the year 2000 by the adoption of bottoming cycles for two different supply projections was estimated as from 0.296 trillion ft/sup 3/ for a low supply projection to 0.734 trillion ft/sup 3/ for a high supply projection. The potential market for bottoming cycle equipment for the two supply projections varied from 170 to 500 units of varying size. Finally, a demonstration program plan was developed.« less

75 FR 38805 - Central New York Oil and Gas Company, LLC; Notice of Intent To Prepare an Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-06

... station locations in Bradford County, Pennsylvania and Tioga County, New York. All interested parties... locations: FERC Environmental Site Reviews North-South Project Compressor Station NS2--Bradford County, Pennsylvania July 14, 2010, at 2 p.m. Tennessee Gas Pipeline's Station 319 (driveway) Turkey Path Road (State...

76 FR 59678 - Notice of Intent To Prepare an Environmental Assessment for the Proposed Marshfield Reduction...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-27

... compressor unit; An 8,400 gallon condensate tank; A 2 million British Thermal Unit per hour natural gas... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP11-539-000] Notice of... for Comments on Environmental Issues; ANR Pipeline Company The staff of the Federal Energy Regulatory...

78 FR 20133 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Bull Mountain Unit...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-03

... associated pads, access roads, gas and water pipelines, screw compressors and overhead electric lines. This... projected air quality impacts. The project was initially scoped from October 29 to December 12, 2008, for 55..., the BLM has identified the following preliminary issues: Air quality; water quality and supply...

Four-Spot Time-Of-Flight Laser Anemometer For Turbomachinery

NASA Technical Reports Server (NTRS)

Wernet, Mark P.; Skoch, Gary J.

1995-01-01

Two-color, four-spot time-of-flight laser anemometer designed for measuring flow velocity within narrow confines of small centrifugal compressor. Apparatus well suited for measuring fast (typical speeds 160 to 700 m/s), highly turbulent gas flows in turbomachinery. Other potential applications include measurement of gas flows in pipelines and in flows from explosions.

75 FR 42740 - Ryckman Creek Resources, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-22

.... Create a central gas/liquids separation facility (Ryckman Plant) where all of the gas pipelines meet. It would contain a small electric-driven compressor to compress casing head gas, liquids separation... Convenience and Necessity under section 7 of the Natural Gas Act. The Bureau of Land Management (BLM) is...

78 FR 35627 - Columbia Gas Transmission, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-13

... plans to modify one interconnect in New York, three compressor stations in Pennsylvania and one compressor station in Maryland. The Commission will use this EA in its decision-making process to determine... Compressor Station (Milford, Pennsylvania): Abandon the existing compressors and replace them with two Solar...

Putting the environment into the NPV calculation -- Quantifying pipeline environmental costs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dott, D.R.; Wirasinghe, S.C.; Chakma, A.

1996-12-31

Pipeline projects impact the environment through soil and habitat disturbance, noise during construction and compressor operation, river crossing disturbance and the risk of rupture. Assigning monetary value to these negative project consequences enables the environment to be represented in the project cost-benefit analysis. This paper presents the mechanics and implications of two environmental valuation techniques: (1) the contingent valuation method and (2) the stated preference method. The use of environmental value at the project economic-evaluation stage is explained. A summary of research done on relevant environmental attribute valuation is presented and discussed. Recommendations for further research in the field aremore » made.« less

Pipeline scada upgrade uses satellite terminal system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conrad, W.; Skovrinski, J.R.

In the recent automation of its supervisory control and data acquisition (scada) system, Transwestern Pipeline Co. has become the first to use very small aperture satellite terminals (VSAT's) for scada. A subsidiary of Enron Interstate Pipeline, Houston, Transwestern moves natural gas through a 4,400-mile system from West Texas, New Mexico, and Oklahoma to southern California markets. Transwestern's modernization, begun in November 1985, addressed problems associated with its aging control equipment which had been installed when the compressor stations were built in 1960. Over the years a combination of three different systems had been added. All were cumbersome to maintain andmore » utilized outdated technology. Problems with reliability, high maintenance time, and difficulty in getting new parts were determining factors in Transwestern's decision to modernize its scada system. In addition, the pipeline was anticipating moving its control center from Roswell, N.M., to Houston and believed it would be impossible to marry the old system with the new computer equipment in Houston.« less

77 FR 1674 - Tennessee Gas Pipeline Company, L.L.C.; Notice of Intent To Prepare an Environmental Assessment...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-11

... stations to provide bi-directional natural gas flow: a. Station 219, in Mercer County; b. Station 303, in Venango County; c. Station 310, in McKean County; and d. Station 313, in Potter County. The general... yards, compressor stations, and access roads). Our EA for this project will document our findings on the...

78 FR 15364 - Gulf Crossing Pipeline Company LLC; Notice of Intent To Prepare an Environmental Assessment for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-11

... Sherman Compressor Station located 10 miles northeast of Sherman, Texas, to Panda Sherman Power, LLC's... barrel and meter station consisting of a 16-inch receiver barrel and associated piping and valves at MP... control station to be built, owned, and operated by ETP. The general location of the project facilities is...

76 FR 54758 - Alliance Pipeline L.P.; Notice of Intent To Prepare an Environmental Assessment for the Planned...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-02

... Counties, North Dakota; A 4,500 horsepower compressor station containing two natural gas-driven engines... included in the User's Guide under the ``e-filing'' link on the Commission's Web site. Please note that the... on ``General Search'' and enter the docket number, excluding the last three digits in the Docket...

An experimental and computational investigation of flow in a radial inlet of an industrial pipeline centrifugal compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flathers, M.B.; Bache, G.E.; Rainsberger, R.

1996-04-01

The flow field of a complex three-dimensional radial inlet for an industrial pipeline centrifugal compressor has been experimentally determined on a half-scale model. Based on the experimental results, inlet guide vanes have been designed to correct pressure and swirl angle distribution deficiencies. The unvaned and vaned inlets are analyzed with a commercially available fully three-dimensional viscous Navier-Stokes code. Since experimental results were available prior to the numerical study, the unvaned analysis is considered a postdiction while the vaned analysis is considered a prediction. The computational results of the unvaned inlet have been compared to the previously obtained experimental results. Themore » experimental method utilized for the unvaned inlet is repeated for the vaned inlet and the data have been used to verify the computational results. The paper will discuss experimental, design, and computational procedures, grid generation, boundary conditions, and experimental versus computational methods. Agreement between experimental and computational results is very good, both in prediction and postdiction modes. The results of this investigation indicate that CFD offers a measurable advantage in design, schedule, and cost and can be applied to complex, three-dimensional radial inlets.« less

76 FR 2365 - Dominion Transmission, Inc.; Notice of Intent To Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-13

... installed at three existing compressor stations, a new meter station, and an upgrade at an existing regulator station, all located at existing DTI facilities in Pennsylvania. This EA will be used by the... Compressor Station in Jefferson/Indiana, Elk, and Clinton Counties, Pennsylvania. All construction would take...

10 CFR Appendix D to Part 110 - Illustrative List of Aerodynamic Enrichment Plant Equipment and Components Under NRC Export...

Code of Federal Regulations, 2010 CFR

2010-01-01

... equipment, pipeline and instrumentation surfaces (that come in contact with the gas) must be made of materials that remain stable in contact with UF6. All surfaces which come into contact with the process gas... compressors or gas blowers made of or protected by materials resistant to UF6 corrosion and with a suction...

Aerodynamic Design of Axial-flow Compressors. Volume III

NASA Technical Reports Server (NTRS)

Johnson, Irving A; Bullock, Robert O; Graham, Robert W; Costilow, Eleanor L; Huppert, Merle C; Benser, William A; Herzig, Howard Z; Hansen, Arthur G; Jackson, Robert J; Yohner, Peggy L;

Gas pipeline relief valves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bright, G.F.

1974-01-01

A discussion of the increasing activity of natural gas pipeline companies in the analysis of the overpressure protection methods for complying with the provisions of Part 192, Title 49, Code of Federal Regulations ''Transportation of Natural and Other Gas by Pipelines; Minimum Federal Safety Standards'' and with the USAS B31.8 Code covers the basic requirements for protection against accidental overpressure as being essentially the same in both documents, i.e., at the maximum allowable operating overpressure in a gas system can be exceeded either at a compressor station or downstream of a pressure control valve; mandatory use of overpressure protection devicesmore » in these situations, except for those cases which exempt some service regulators because the distribution system pressure is less than 60 psig and six other requirements of design, performance, and size are met; and basic design requirements of a pressure relief or limiting station and the components used.« less

Tumor-specific frequencies and ocular melanoma.

PubMed

Milham, Samuel; Stetzer, David

2017-01-01

Specific kilohertz frequencies in the environment from variable frequency drives on electric motors at a liquid natural gas compressor and storage station on a natural gas pipeline seem to be associated with the development of a very rare cancer, ocular melanoma, at a high school and in individuals living or working in a neighborhood near the plant. Primary neutral-to-earth oscilloscope voltage waveforms and spectra measured near the high school were nearly identical to the ground voltage 2.3 miles away at the gas pipeline. Peak frequencies of 7440 and 19,980 Hz were found at both places. The electric utility practice of using the earth as a conduit for return currents facilitated this exposure.

Active identification and control of aerodynamic instabilities in axial and centrifugal compressors

NASA Astrophysics Data System (ADS)

Krichene, Assad

In this thesis, it is experimentally shown that dynamic cursors to stall and surge exist in both axial and centrifugal compressors using the experimental axial and centrifugal compressor rigs located in the School of Aerospace Engineering at the Georgia Institute of Technology. Further, it is shown that the dynamic cursors to stall and surge can be identified in real-time and they can be used in a simple control scheme to avoid the occurrence of stall and surge instabilities altogether. For the centrifugal compressor, a previously developed real-time observer is used in order to detect dynamic cursors to surge in real-time. An off-line analysis using the Fast Fourier Transform (FFT) of the open loop experimental data from the centrifugal compressor rig is carried out to establish the influence of compressor speed on the dynamic cursor frequency. The variation of the amplitude of dynamic cursors with compressor operating condition from experimental data is qualitatively compared with simulation results obtained using a generic compression system model subjected to white noise excitation. Using off-line analysis results, a simple control scheme based on fuzzy logic is synthesized for surge avoidance and recovery. The control scheme is implemented in the centrifugal compressor rig using compressor bleed as well as fuel flow to the combustor. Closed loop experimental results are obtained to demonstrate the effectiveness of the controller for both surge avoidance and surge recovery. The existence of stall cursors in an axial compression system is established using the observer scheme from off-line analysis of an existing database of a commercial gas turbine engine. However, the observer scheme is found to be ineffective in detecting stall cursors in the experimental axial compressor rig in the School of Aerospace Engineering at the Georgia Institute of Technology. An alternate scheme based on the amplitude of pressure data content at the blade passage frequency obtained using a pressure sensor located (in the casing) over the blade row is developed and used in the axial compressor rig for stall and surge avoidance and recovery. (Abstract shortened by UMI.)

Dry-running gas seals save $200,000/yr in retrofit hydrogen recycle compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pennacchi, R.P.; Germain, A.

1987-10-01

Texaco Chemical Company was using three drums of oil per day in the seal oil system of a hydrogen recycle compressor, resulting in maintenance and operational expenses of more than $160,000 per year. Running 24 hours/day, 365 days/yr, the 26-yr-old compressor is the heart of the benzene manufacturing process unit at the Port Arthur, Texas plant. In the event of an unscheduled shutdown, the important aromatics unit process would halt and cause production losses of thousands of dollars per day. In addition, the close monitoring and minimization of leakage are essential since the gas consists of over 75% hydrogen, withmore » methane, ethane, propane, isobutane, N-butane and pentanes. Texaco Chemical Company decided that retrofit of the hydrogen recycle compressor should be undertaken if the system could be developed to sharply reduce operations and maintenance costs, and increase efficiencies. Texaco engineers selected a dry running-type gas sealing system developed for pipeline compressors in the United States, Canada, and overseas. A tandem-type sealing system was designed to meet specific needs of a hydrogen recycle compressor. The retrofit was scheduled for August 1986 to coincide with the plant's preventative maintenance program. The seal system installation required five days. The retrofit progressed according to schedule, with no problems experienced at the first and several startups since the initial installation. Oil consumption has been eliminated, along with seal support and parasitic energy requirements. With the savings in seal oil, energy, operations and maintenance, payback period for the retrofit sealing system was just over six months. Savings are expected to continue at an annual rate of over $200,000.« less

78 FR 42516 - Iroquois Gas Transmission System, L.P.; Notice of Intent To Prepare an Environmental Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-16

... Public Scoping Meetings. At that time, Constitution proposed to construct a new compressor station as... has since identified that the objectives of the new compressor station could be met by making modifications at Iroquois' existing Wright Compressor Station in Schoharie County, New York. The other aspects...

Computational Assessment of a 3-Stage Axial Compressor Which Provides Airflow to the NASA 11- by 11-Foot Transonic Wind Tunnel, Including Design Changes for Increased Performance

NASA Technical Reports Server (NTRS)

Kulkarni, Sameer; Beach, Timothy A.; Jorgenson, Philip C.; Veres, Joseph P.

2017-01-01

A 24 foot diameter 3-stage axial compressor powered by variable-speed induction motors provides the airflow in the closed-return 11- by 11-Foot Transonic Wind Tunnel (11-Foot TWT) Facility at NASA Ames Research Center at Moffett Field, California. The facility is part of the Unitary Plan Wind Tunnel, which was completed in 1955. Since then, upgrades made to the 11-Foot TWT such as flow conditioning devices and instrumentation have increased blockage and pressure loss in the tunnel, somewhat reducing the peak Mach number capability of the test section. Due to erosion effects on the existing aluminum alloy rotor blades, fabrication of new steel rotor blades is planned. This presents an opportunity to increase the Mach number capability of the tunnel by redesigning the compressor for increased pressure ratio. Challenging design constraints exist for any proposed design, demanding the use of the existing driveline, rotor disks, stator vanes, and hub and casing flow paths, so as to minimize cost and installation time. The current effort was undertaken to characterize the performance of the existing compressor design using available design tools and computational fluid dynamics (CFD) codes and subsequently recommend a new compressor design to achieve higher pressure ratio, which directly correlates with increased test section Mach number. The constant cross-sectional area of the compressor leads to highly diffusion factors, which presents a challenge in simulating the existing design. The CFD code APNASA was used to simulate the aerodynamic performance of the existing compressor. The simulations were compared to performance predictions from the HT0300 turbomachinery design and analysis code, and to compressor performance data taken during a 1997 facility test. It was found that the CFD simulations were sensitive to endwall leakages associated with stator buttons, and to a lesser degree, under-stator-platform flow recirculation at the hub. When stator button leakages were modeled, pumping capability increased by over 20 of pressure rise at design point due to a large reduction in aerodynamic blockage at the hub. Incorporating the stator button leakages was crucial to matching test data. Under-stator-platform flow recirculation was thought to be large due to a lack of seals. The effect of this recirculation was assessed with APNASA simulations recirculating 0.5, 1, and 2 of inlet flow about stators 1 and 2, modeled as axisymmetric mass flux boundary conditions on the hub before and after the vanes. The injection of flow ahead of the stators tended to re-energize the boundary layer and reduce hub separations, resulting in about 3 increased stall margin per 1 of inlet flow recirculated. In order to assess the value of the flow recirculation, a mixing plane simulation of the compressor which gridded the under-stator cavities was generated using the ADPAC CFD code. This simulation indicated that about 0.65 of the inlet flow is recirculated around each shrouded stator. This collective information was applied during the redesign of the compressor. A potential design was identified using HT0300 which improved overall pressure ratio by removing pre-swirl into rotor 1, replacing existing NASA 65 series rotors with double circular arc sections, and re-staggering rotors and the existing stators. The performance of the new design predicted by APNASA and HT0300 is compared to the existing design.

Hydraulic accumulator-compressor for geopressured enhanced oil recovery

DOEpatents

Goldsberry, Fred L.

1988-01-01

A hydraulic accumulator-compressor vessel using geothermal brine under pressure as a piston to compress waste (CO.sub.2 rich) gas is used in a system having a plurality of gas separators in tandem to recover pipeline quality gas from geothermal brine. A first high pressure separator feeds gas to a membrance separator which separates low pressure waste gas from high pressure quality gas. A second separator produces low pressure waste gas. Waste gas from both separators is combined and fed into the vessel through a port at the top as the vessel is drained for another compression cycle. High pressure brine is then admitted into the vessel through a port at the bottom of the vessel. Check valves control the flow of low pressure waste gas into the vessel and high pressure waste gas out of the vessel.

Coordinates for a High Performance 4:1 Pressure Ratio Centrifugal Compressor

NASA Technical Reports Server (NTRS)

McKain, Ted F.; Holbrook, Greg J.

1997-01-01

The objective of this program was to define the aerodynamic design and manufacturing coordinates for an advanced 4:1 pressure ratio, single stage centrifugal compressor at a 10 lbm/sec flow size. The approach taken was to perform an exact scale of an existing DDA compressor originally designed at a flow size of 3.655 lbm/sec.

Development of a linear compressor for compact 2 K Gifford- McMahon cryocoolers

NASA Astrophysics Data System (ADS)

Hiratsuka, Y.

2015-12-01

Recently, a new, compact Gifford-McMahon (GM) cryocooler for cooling superconducting single photon detectors (SSPD) has been developed at Sumitomo Heavy Industries, Ltd. (SHI) [1, 2]. The objective is to reduce the total height of the expander by 33% relative to the existing RDK-101 GM expander and to reduce the total volume of the compressor unit by 50% relative to the existing CNA-11 compressor. In addition, considering the targeted cooling application, we set the design temperature targets of the first and the second stages to 1 W and 20 mW of heat load at 60 K and 2.3 K, respectively. Although optimization of the internal components is one way to miniaturize the volume of the compressor unit, major design changes are required because the volume of the adsorber and the oil separator is almost the same as the volume of the compressor capsule. Thus, one approach is to develop a non-lubricated compressor, such as a valved linear compressor. An experimental unit of a valved linear compressor was designed and built, and preliminary experiments were conducted. Under no-load condition, a low temperature of 2.19 K has been achieved. With 1 W and 14 mW heat load, the temperature is 48 K at the first stage and 2.3 K at the second stage, with an input power of about 1.2 KW. The detailed experimental results will be discussed in this paper.

Metal Hydride Compression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Terry A.; Bowman, Robert; Smith, Barton

Conventional hydrogen compressors often contribute over half of the cost of hydrogen stations, have poor reliability, and have insufficient flow rates for a mature FCEV market. Fatigue associated with their moving parts including cracking of diaphragms and failure of seal leads to failure in conventional compressors, which is exacerbated by the repeated starts and stops expected at fueling stations. Furthermore, the conventional lubrication of these compressors with oil is generally unacceptable at fueling stations due to potential fuel contamination. Metal hydride (MH) technology offers a very good alternative to both conventional (mechanical) and newly developed (electrochemical, ionic liquid pistons) methodsmore » of hydrogen compression. Advantages of MH compression include simplicity in design and operation, absence of moving parts, compactness, safety and reliability, and the possibility to utilize waste industrial heat to power the compressor. Beyond conventional H2 supplies of pipelines or tanker trucks, another attractive scenario is the on-site generating, pressuring and delivering pure H 2 at pressure (≥ 875 bar) for refueling vehicles at electrolysis, wind, or solar generating production facilities in distributed locations that are too remote or widely distributed for cost effective bulk transport. MH hydrogen compression utilizes a reversible heat-driven interaction of a hydride-forming metal alloy with hydrogen gas to form the MH phase and is a promising process for hydrogen energy applications [1,2]. To deliver hydrogen continuously, each stage of the compressor must consist of multiple MH beds with synchronized hydrogenation & dehydrogenation cycles. Multistage pressurization allows achievement of greater compression ratios using reduced temperature swings compared to single stage compressors. The objectives of this project are to investigate and demonstrate on a laboratory scale a two-stage MH hydrogen (H 2) gas compressor with a feed pressure of >50 bar and a delivery pressure ≥ 875 bar of high purity H 2 gas using the scheme shown in Figure 1. Progress to date includes the selection of two candidate metal hydrides for each compressor stage, supplier engagement and synthesis of small samples, and the beginning of in-depth characterization of their thermodynamics, kinetics, and hydrogen capacities for optimal performance with respect to energy requirements and efficiency. Additionally, bed design trade studies are underway and will be finalized in FY18. Subsequently, the prototype two-stage compressor will be fabricated, assembled and experimentally evaluated in FY19.« less

Effect of Rotor- and Stator-Blade Modifications on Surge Performance of an 11-Stage Axial-Flow Compressor. I - Original Production Compressor of XJ40-WE-6 Engine

NASA Technical Reports Server (NTRS)

Finger, Harold B.; Essig, Robert H.; Conrad, E. William

1952-01-01

An investigation to increase the compressor surge-limit pressure ratio of the XJ40-WE-6 turbojet engine at high equivalent speeds was conducted at the NACA Lewis altitude wind tunnel. This report evaluates the compressor modifications which were restricted to (1) twisting rotor blades (in place) to change blade section angles and (2) inserting new stator diaphragms with different blade angles. Such configuration changes could be incorporated quickly and easily in existing engines at overhaul depots. It was found that slight improvements in the compressor surge limit were possible by compressor blade adjustment. However, some of the modifications also reduced the engine air flow and hence penalized the thrust. The use of a mixer assembly at the compressor outlet improved the surge limit with no appreciable thrust penalty.

Analysis and optimization of indicators of energy and resource consumption of gas turbine and electric drives for transportation of hydrocarbons

NASA Astrophysics Data System (ADS)

Golik, V. V.; Zemenkova, M. Yu; Seroshtanov, I. V.; Begalko, Z. V.

2018-05-01

The paper presents the results of the analysis of statistical indicators of energy and resource consumption in oil and gas transportation by the example of one of the regions of Russia. The article analyzes engineering characteristics of compressor station drives. Official statistical bulletins on the fuel and energy resources of the region in the pipeline oil and gas transportation system were used as the initial data.

Apparatus for the liquefaction of a gas and methods relating to same

DOEpatents

Turner, Terry D [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID

2009-12-29

Apparatuses and methods are provided for producing liquefied gas, such as liquefied natural gas. In one embodiment, a liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream may be sequentially pass through a compressor and an expander. The process stream may also pass through a compressor. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. A portion of the liquid gas may be used for additional cooling. Gas produced within the system may be recompressed for reintroduction into a receiving line.

Experimental/analytical approach to understanding mistuning in a transonic wind tunnel compressor

NASA Technical Reports Server (NTRS)

Kaiser, Teri; Hansen, Reed S.; Nguyen, Nhan; Hampton, Roy W.; Muzzio, Doug; Chargin, Mladen K.; Guist, Roy; Hamm, Ken; Walker, Len

1994-01-01

This paper will briefly set forth some of the basic tenets of mistuned rotating bladed-disk assemblies. The experience with an existing three stage compressor in a transonic wind tunnel will be documented. The manner in which the theoretical properties manifest themselves in this non-ideal compressor will be described. A description of mistuning behaviors that can and cannot be accurately substantiated will be discussed.

Analysis and identification of subsynchronous vibration for a high pressure parallel flow centrifugal compressor

NASA Technical Reports Server (NTRS)

Kirk, R. G.; Nicholas, J. C.; Donald, G. H.; Murphy, R. C.

1980-01-01

The summary of a complete analytical design evaluation of an existing parallel flow compressor is presented and a field vibration problem that manifested itself as a subsynchronous vibration that tracked at approximately 2/3 of compressor speed is reviewed. The comparison of predicted and observed peak response speeds, frequency spectrum content, and the performance of the bearing-seal systems are presented as the events of the field problem are reviewed. Conclusions and recommendations are made as to the degree of accuracy of the analytical techniques used to evaluate the compressor design.

Rotating stall investigation of 0.72 hub-tip ratio single-stage compressor

NASA Technical Reports Server (NTRS)

Graham, Robert W; Prian, Vasily D

1954-01-01

The rotating stall characteristics of a 0.72 hub-tip ratio, single-stage compressor were investigated. The stage was a 14-inch-diameter replica of the fourth stage of an experimental multistage compressor. No similarity existed between the frequency and propagation rate of the stall patterns observed in the single-stage replica and those observed in the multistage compressor after the fourth stage. A fatigue failure of the rotor blades occurred during the testing which was attributed to a resonance between the stall frequency and the natural bending frequency of the blades.

Performance Measurements and Mapping of a R-407C Vapor Injection Scroll Compressor

NASA Astrophysics Data System (ADS)

Lumpkin, Domenique; Spielbauer, Niklas; Groll, Eckhard

2017-08-01

Environmental conditions significantly define the performance of HVAC&R systems. Vapor compression systems in hot climates tend to operate at higher pressure ratios, leading to increased discharge temperatures. Higher discharge temperatures can lead to higher irreversibilities in the compression process, lower specific enthalpies differences across the evaporator, and possibly a reduction in the compressor life due to the breakdown of the oil used for lubrication. To counter these effects, the use of economized, vapor injection compressors is proposed for vapor compression systems in high temperature climates. Such compressors are commercially available for refrigeration applications, in particular, supermarket refrigeration systems. However, compressor maps for vapor injection compressors are limited and none exist for R-407C. Through calorimeter testing, a compressor map for a single-port vapor injection compressor using R-407C was developed. A standard correlation for mapping single-port vapor injection compressors is proposed and validated using the compressor test results. The system and compressor performance with and without vapor injection was considered. As expected, with vapor injection there was a reduction in compressor discharge temperatures and an increase in the system coefficient of performance. The proposed dimensionless correlation is more accurate than the AHRI polynomial for mapping the injection ratio, discharge temperature, and compressor heat loss. The predicted volumetric efficiency values from the dimensionless correlation is within 1% of the measured valued. Similarly, the predicted isentropic efficiency values are within 2% of the measured values.

Feasibility study for the construction of a new LNG receiving terminal, turkey. Volume 2. Appendix. Export trade information. [LNG (liquified natural gas)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-06-01

The report was prepared by The M. W. Kellogg Co. for BOTAS Petroleum Pipeline Corporation of Ankara, Turkey. The study was undertaken to evaluate the cost and economics of constructing a second liquified natural gas (LNG) terminal in Turkey to meet future requirements for natural gas. Volume 2 contains the following appendices: LNG Storage Tanks; Vaporizers; Compressors; Pumps; Loading Arms; Marine Installations; Shipping; and Seismic Study.

Centrifugal Compressor Aeroelastic Analysis Code

NASA Astrophysics Data System (ADS)

Keith, Theo G., Jr.; Srivastava, Rakesh

2002-01-01

Centrifugal compressors are very widely used in the turbomachine industry where low mass flow rates are required. Gas turbine engines for tanks, rotorcraft and small jets rely extensively on centrifugal compressors for rugged and compact design. These compressors experience problems related with unsteadiness of flowfields, such as stall flutter, separation at the trailing edge over diffuser guide vanes, tip vortex unsteadiness, etc., leading to rotating stall and surge. Considerable interest exists in small gas turbine engine manufacturers to understand and eventually eliminate the problems related to centrifugal compressors. The geometric complexity of centrifugal compressor blades and the twisting of the blade passages makes the linear methods inapplicable. Advanced computational fluid dynamics (CFD) methods are needed for accurate unsteady aerodynamic and aeroelastic analysis of centrifugal compressors. Most of the current day industrial turbomachines and small aircraft engines are designed with a centrifugal compressor. With such a large customer base and NASA Glenn Research Center being, the lead center for turbomachines, it is important that adequate emphasis be placed on this area as well. Currently, this activity is not supported under any project at NASA Glenn.

Development of Carbon Dioxide Hermitic Compressor

NASA Astrophysics Data System (ADS)

Imai, Satoshi; Oda, Atsushi; Ebara, Toshiyuki

Because of global environmental problems, the existing refrigerants are to be replaced with natural refrigerants. CO2 is one of the natural refrigerants and environmentally safe, inflammable and non-toxic refrigerant. Therefore high efficiency compressor that can operate with natural refrigerants, especially CO2, needs to be developed. We developed a prototype CO2 hermetic compressor, which is able to use in carbon dioxide refrigerating systems for practical use. The compressor has two rolling pistons, and it leads to low vibrations, low noise. In additions, two-stage compression with two cylinders is adopted, because pressure difference is too large to compress in one stage. And inner pressure of the shell case is intermediate pressure to minimize gas leakage between compressing rooms and inner space of shell case. Intermediate pressure design enabled to make the compressor smaller in size and lighter in weight. As a result, the compressor achieved high efficiency and high reliability by these technology. We plan to study heat pump water heater, cup vending machine and various applications with CO2 compressor.

Temperature factors effect on occurrence of stress corrosion cracking of main gas pipeline

NASA Astrophysics Data System (ADS)

Nazarova, M. N.; Akhmetov, R. R.; Krainov, S. A.

2017-10-01

The purpose of the article is to analyze and compare the data in order to contribute to the formation of an objective opinion on the issue of the growth of stress corrosion defects of the main gas pipeline. According to available data, a histogram of the dependence of defects due to stress corrosion on the distance from the compressor station was constructed, and graphs of the dependence of the accident density due to stress corrosion in the winter and summer were also plotted. Data on activation energy were collected and analyzed in which occurrence of stress corrosion is most likely constructed, a plot of activation energy versus temperature is plotted, and the process of occurrence of stress corrosion by the example of two different grades of steels under the action of different temperatures was analyzed.

PC-based automation system streamlines operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowman, J.

1995-10-01

The continued emergence of PC-based automation systems in the modern compressor station is driving the need for personnel who have the special skills need to support them. However, the dilemma is that operating budget restraints limit the overall number of people available to operate and maintain compressor stations. An ideal solution is to deploy automation systems which can be easily understood and supported by existing compressor station personnel. This paper reviews such a system developed by Waukesha-Pearce Industries, Inc.

Performance estimation of an oil-free linear compressor unit for a new compact 2K Gifford-McMahon cryocooler

NASA Astrophysics Data System (ADS)

Hiratsuka, Y.; Bao, Q.; Y Xu, M.

2017-12-01

Since 2012, a new, compact Gifford-McMahon (GM) cryocooler for cooling superconducting single photon detectors (SSPD) has been developed and reported by Sumitomo Heavy Industries, Ltd. (SHI). Also, it was reported that National Institute of Information and Communications Technology (NICT) developed a multi-channel, conduction-cooled SSPD system. However, the size and power consumption reduction becomes indispensable to apply such a system to the optical communication of AdHoc for a mobile system installed in a vehicle. The objective is to reduce the total height of the expander by 33% relative to the existing RDK-101 GM expander and to reduce the total volume of the compressor unit by 50% relative to the existing CNA-11 compressor. In addition, considering the targeted cooling application, we set the design cooling capacity targets of the first and the second stages 1 W at 60 K and 20 mW at 2.3 K respectively. In 2016, Hiratsuka et al. reported that an oil-free compressor was developed for a 2K GM cryocooler. The cooling performance of a 2K GM expander driven by an experimental unit of the linear compressor was measured. No-load temperature less than 2.1 K and the cooling capacity of 20 mW at 2.3 K were successfully achieved with an electric input power of only 1.1 kW. After that, the compressor capsule and the heat exchanger, etc. were assembled into one enclosure as a compressor unit. The total volume of the compressor unit and electrical box was significantly reduced to about 38 L, which was close to the target of 35 L. Also, the sound noise, vibration characteristics, the effect of the compressor unit inclination and the ambient temperature on the cooling performance, were evaluated. The detailed experimental results are discussed in this paper.

Energy efficient engine low-pressure compressor component test hardware detailed design report

NASA Technical Reports Server (NTRS)

Michael, C. J.; Halle, J. E.

1981-01-01

The aerodynamic and mechanical design description of the low pressure compressor component of the Energy Efficient Engine were used. The component was designed to meet the requirements of the Flight Propulsion System while maintaining a low cost approach in providing a low pressure compressor design for the Integrated Core/Low Spool test required in the Energy Efficient Engine Program. The resulting low pressure compressor component design meets or exceeds all design goals with the exception of surge margin. In addition, the expense of hardware fabrication for the Integrated Core/Low Spool test has been minimized through the use of existing minor part hardware.

Pulsation damping of the reciprocating compressor with Helmholtz resonator

NASA Astrophysics Data System (ADS)

Wang, W.; Zhang, Y.; Zhou, Q.; Peng, X.; Feng, J.; Jia, X.

2017-08-01

Research presented in this paper investigated the mounting of a Helmholtz resonator near the valve chamber of a reciprocating compressor to attenuate the gas pulsation in the valve chamber as well as the pipeline downstream. Its attenuation characteristics were simulated with the plane wave theory together with the transfer matrix method, and the damping effect was checked by comparing the pressure pulsation levels before and after mounting the resonator. The results show that the Helmholtz resonator was effective in attenuating the gas pulsation in the valve chamber and piping downstream, and the pulsation level was decreased by 40% in the valve chamber and 30% at maximum in the piping downstream. The damping effect of the resonator was sensitive to its resonant frequency, and various resonators working simultaneously didn’t interfere with each other. When two resonators were mounted in parallel, with resonant frequencies equal to the second and fourth harmonic frequencies, the pressure pulsation components corresponding to the resonant frequencies were remarkably decreased at the same time, while the pulsation levels at other harmonic frequencies kept almost unchanged. After a series of simulations and experiments a design criterion of chock tube and volume parameter has been proposed for the targeted frequencies to be damped. Furthermore, the frequency-adjustable Helmholtz resonator which was applied to the variable speed compressor was investigated.

UNDERSTANDING METHANE EMISSIONS SOURCES AND VIABLE MITIGATION MEASURES IN THE NATURAL GAS TRANSMISSION SYSTEMS: RUSSIAN AND U.S. EXPERIENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishkov, A.; Akopova, Gretta; Evans, Meredydd

This article will compare the natural gas transmission systems in the U.S. and Russia and review experience with methane mitigation technologies in the two countries. Russia and the United States (U.S.) are the world's largest consumers and producers of natural gas, and consequently, have some of the largest natural gas infrastructure. This paper compares the natural gas transmission systems in Russia and the U.S., their methane emissions and experiences in implementing methane mitigation technologies. Given the scale of the two systems, many international oil and natural gas companies have expressed interest in better understanding the methane emission volumes and trendsmore » as well as the methane mitigation options. This paper compares the two transmission systems and documents experiences in Russia and the U.S. in implementing technologies and programs for methane mitigation. The systems are inherently different. For instance, while the U.S. natural gas transmission system is represented by many companies, which operate pipelines with various characteristics, in Russia predominately one company, Gazprom, operates the gas transmission system. However, companies in both countries found that reducing methane emissions can be feasible and profitable. Examples of technologies in use include replacing wet seals with dry seals, implementing Directed Inspection and Maintenance (DI&M) programs, performing pipeline pump-down, applying composite wrap for non-leaking pipeline defects and installing low-bleed pneumatics. The research methodology for this paper involved a review of information on methane emissions trends and mitigation measures, analytical and statistical data collection; accumulation and analysis of operational data on compressor seals and other emission sources; and analysis of technologies used in both countries to mitigate methane emissions in the transmission sector. Operators of natural gas transmission systems have many options to reduce natural gas losses. Depending on the value of gas, simple, low-cost measures, such as adjusting leaking equipment components, or larger-scale measures, such as installing dry seals on compressors, can be applied.« less

CO2 Compressor Requirements for Integration of Space Station Carbon Dioxide Removal and Carbon Dioxide Reduction Assemblies

NASA Technical Reports Server (NTRS)

Jeng, Frank F.; Lewis, John F.; Graf, John; LaFuse, Sharon; Nicholson, Leonard S. (Technical Monitor)

1999-01-01

This paper describes the analysis on integration requirements, CO2 compressor in particular, for integration of Carbon Dioxide Removal Assembly (CDRA) and CO2 Reduction Assembly (CRA) as a part of the Node 3 project previously conducted at JSC/NASA. A system analysis on the volume and operation pressure range of the CO2 accumulator was conducted. The hardware and operational configurations of the CO2 compressor were developed. The performance and interface requirements of the compressor were specified. An existing Four-Bed Molecular Sieve CO2 removal computer model was modified into a CDRA model and used in analyzing the requirements of the CDRA CO2 compressor. This CDRA model was also used in analyzing CDRA operation parameters that dictate CO2 pump sizing. Strategy for the pump activation was also analyzed.

Assessing fugitive emissions of CH4 from high-pressure gas pipelines in the UK

NASA Astrophysics Data System (ADS)

Clancy, S.; Worrall, F.; Davies, R. J.; Almond, S.; Boothroyd, I.

2016-12-01

Concern over the greenhouse gas impact of the exploitation of unconventional natural gas from shale deposits has caused a spotlight to be shone on to the entire hydrocarbon industry. Numerous studies have developed life-cycle emissions inventories to assess the impact that hydraulic fracturing has upon greenhouse gas emissions. Incorporated within life-cycle assessments are transmission and distribution losses, including infrastructure such as pipelines and compressor stations that pressurise natural gas for transport along pipelines. Estimates of fugitive emissions from transmission, storage and distribution have been criticized for reliance on old data from inappropriate sources (1970s Russian gas pipelines). In this study, we investigate fugitive emissions of CH4 from the UK high pressure national transmission system. The study took two approaches. Firstly, CH4 concentration is detected by driving along roads bisecting high pressure gas pipelines and also along an equivalent distance along a route where no high pressure gas pipeline was nearby. Five pipelines and five equivalent control routes were driven and the test was that CH4 measurements, when adjusted for distance and wind speed, should be greater on any route with a pipe than any route without a pipe. Secondly, 5 km of a high pressure gas pipeline and 5 km of equivalent farmland, were walked and soil gas (above the pipeline where present) was analysed every 7 m using a tunable diode laser. When wind adjusted 92 km of high pressure pipeline and 72 km of control route were drive over a 10 day period. When wind and distance adjusted CH4 fluxes were significantly greater on routes with a pipeline than those without. The smallest leak detectable was 3% above ambient (1.03 relative concentration) with any leaks below 3% above ambient assumed ambient. The number of leaks detected along the pipelines correlate to the estimated length of pipe joints, inferring that there are constant fugitive CH4 emissions from these joints. When scaled up to the UK's National Transmission System pipeline length of 7600 km gives a fugitive CH4 flux of 62.6 kt CH4/yr with a CO2 equivalent of 1570 kt CO2eq/yr - this fugitive emission from high pressure pipelines is 0.14% of the annual gas supply.

Available pressure amplitude of linear compressor based on phasor triangle model

NASA Astrophysics Data System (ADS)

Duan, C. X.; Jiang, X.; Zhi, X. Q.; You, X. K.; Qiu, L. M.

2017-12-01

The linear compressor for cryocoolers possess the advantages of long-life operation, high efficiency, low vibration and compact structure. It is significant to study the match mechanisms between the compressor and the cold finger, which determines the working efficiency of the cryocooler. However, the output characteristics of linear compressor are complicated since it is affected by many interacting parameters. The existing matching methods are simplified and mainly focus on the compressor efficiency and output acoustic power, while neglecting the important output parameter of pressure amplitude. In this study, a phasor triangle model basing on analyzing the forces of the piston is proposed. It can be used to predict not only the output acoustic power, the efficiency, but also the pressure amplitude of the linear compressor. Calculated results agree well with the measurement results of the experiment. By this phasor triangle model, the theoretical maximum output pressure amplitude of the linear compressor can be calculated simply based on a known charging pressure and operating frequency. Compared with the mechanical and electrical model of the linear compressor, the new model can provide an intuitionistic understanding on the match mechanism with faster computational process. The model can also explain the experimental phenomenon of the proportional relationship between the output pressure amplitude and the piston displacement in experiments. By further model analysis, such phenomenon is confirmed as an expression of the unmatched design of the compressor. The phasor triangle model may provide an alternative method for the compressor design and matching with the cold finger.

Analysis of rig test data for an axial/centrifugal compressor in the 12 kg/sec

NASA Technical Reports Server (NTRS)

Owen, A. K.

1994-01-01

Extensive testing was done on a T55-L-712 turboshaft engine compressor in a compressor test rig at TEXTRON/Lycoming. These rig tests will be followed by a series of engine tests to occur at the NASA Lewis Research Center beginning in the last quarter of 1993. The goals of the rig testing were: (1) map the steady state compressor operation from 20 percent to 100 percent design speed, (2) quantify the effects of compressor bleed on the operation of the compressor, and (3) explore and measure the operation of the compressor in the flow ranges 'beyond' the normal compressor stall line. Instrumentation consisted of 497 steady state pressure sensors, 153 temperature sensors and 34 high response transducers for transient analysis in the pre- and post-stall operating regime. These measurements allow for generation of detailed stage characteristics as well as overall mapping. Transient data is being analyzed for the existence of modal disturbances at the front face of the compression system ('stall precursors'). This paper presents some preliminary results of the ongoing analysis and a description of the current and future program plans. It will primarily address the unsteady events at the front face of the compression system that occur as the system transitions from steady state to unsteady (stall/surge) operation.

Dynamic model including piping acoustics of a centrifugal compression system

NASA Astrophysics Data System (ADS)

van Helvoirt, Jan; de Jager, Bram

2007-04-01

This paper deals with low-frequency pulsation phenomena in full-scale centrifugal compression systems associated with compressor surge. The Greitzer lumped parameter model is applied to describe the dynamic behavior of an industrial compressor test rig and experimental evidence is provided for the presence of acoustic pulsations in the compression system under study. It is argued that these acoustic phenomena are common for full-scale compression systems where pipe system dynamics have a significant influence on the overall system behavior. The main objective of this paper is to extend the basic compressor model in order to include the relevant pipe system dynamics. For this purpose a pipeline model is proposed, based on previous developments for fluid transmission lines. The connection of this model to the lumped parameter model is accomplished via the selection of appropriate boundary conditions. Validation results will be presented, showing a good agreement between simulation and measurement data. The results indicate that the damping of piping transients depends on the nominal, time-varying pressure and flow velocity. Therefore, model parameters are made dependent on the momentary pressure and a switching nonlinearity is introduced into the model to vary the acoustic damping as a function of flow velocity. These modifications have limited success and the results indicate that a more sophisticated model is required to fully describe all (nonlinear) acoustic effects. However, the very good qualitative results show that the model adequately combines compressor and pipe system dynamics. Therefore, the proposed model forms a step forward in the analysis and modeling of surge in full-scale centrifugal compression systems and opens the path for further developments in this field.

Blending Hydrogen into Natural Gas Pipeline Networks. A Review of Key Issues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melaina, M. W.; Antonia, O.; Penev, M.

2013-03-01

This study assesses the potential to deliver hydrogen through the existing natural gas pipeline network as a hydrogen and natural gas mixture to defray the cost of building dedicated hydrogen pipelines. Blending hydrogen into the existing natural gas pipeline network has also been proposed as a means of increasing the output of renewable energy systems such as large wind farms.

75 FR 13644 - TORP Terminal LP, Bienville Offshore Energy Terminal Liquefied Natural Gas Deepwater Port License...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-22

... interconnect pipelines to four existing offshore pipelines (Dauphin Natural Gas Pipeline, Williams Natural Gas Pipeline, Destin Natural Gas Pipeline, and Viosca Knoll Gathering System [VKGS] Gas Pipeline) that connect to the onshore natural gas transmission pipeline system. Natural gas would be delivered to customers...

New Compressor Added to Glenn's 450- psig Combustion Air System

NASA Technical Reports Server (NTRS)

Swan, Jeffrey A.

2000-01-01

In September 1999, the Central Process Systems Engineering Branch and the Maintenance and the Central Process Systems Operations Branch, released for service a new high pressure compressor to supplement the 450-psig Combustion Air System at the NASA Glenn Research Center at Lewis Field. The new compressor, designated C-18, is located in Glenn s Central Air Equipment Building and is remotely operated from the Central Control Building. C-18 can provide 40 pounds per second (pps) of airflow at pressure to our research customers. This capability augments our existing system capacity (compressors C 4 at 38 pps and C-5 at 32 pps), which is generated from Glenn's Engine Research Building. The C-18 compressor was originally part of Glenn's 21-Inch Hypersonic Tunnel, which was transferred from the Jet Propulsion Laboratory to Glenn in the mid-1980's. With the investment of construction of facilities funding, the compressor was modified, new mechanical and electrical support equipment were purchased, and the unit was installed in the basement of the Central Air Equipment Building. After several weeks of checkout and troubleshooting, the new compressor was ready for long-term, reliable operations. With a total of 110 pps in airflow now available, Glenn is well positioned to support the high-pressure air test requirements of our research customers.

Investigation of CO2 release pressures in pipeline cracks

NASA Astrophysics Data System (ADS)

Gorenz, Paul; Herzog, Nicoleta; Egbers, Christoph

2013-04-01

The CCS (Carbon Capture and Storage) technology can prevent or reduce the emissions of carbon dioxide. The main idea of this technology is the segregation and collection of CO2 from facilities with a high emission of that greenhouse gas, i.e. power plants which burn fossil fuels. To segregate CO2 from the exhaust gas the power plant must be upgraded. Up to now there are three possible procedures to segregate the carbon dioxide with different advantages and disadvantages. After segregation the carbon dioxide will be transported by pipeline to a subsurface storage location. As CO2 is at normal conditions (1013,25 Pa; 20 °C) in a gaseous phase state it must be set under high pressure to enter denser phase states to make a more efficient pipeline transport possible. Normally the carbon dioxide is set into the liquid or supercritical phase state by compressor stations which compress the gas up to 15 MPa. The pressure drop makes booster stations along the pipeline necessary which keep the CO2 in a dens phase state. Depending on the compression pressure CO2 can be transported over 300km without any booster station. The goal of this work is the investigation of release pressures in pipeline cracks. The high pressurised pipeline system consists of different parts with different failure probabilities. In most cases corrosion or obsolescence is the reason for pipeline damages. In case of a crack CO2 will escape from the pipeline and disperse into the atmosphere. Due to its nature CO2 can remain unattended for a long time. There are some studies of the CO2 dispersion process, e.g. Mazzoldi et al. (2007, 2008 and 2011) and Wang et al. (2008), but with different assumptions concerning the pipeline release pressures. To give an idea of realistic release pressures investigations with the CFD tool OpenFOAM were carried out and are presented within this work. To cover such a scenario with an accidental release of carbon dioxide a pipeline section with different diameters and leakage release holes were modelled. This pipeline section is 10m long with the leakage hole in the middle. Additionally a small environment subdomain is simulated around the crack. For computation a multiphase solver was utilised. In a first step incompressible and isothermal fluids with no phase change were assumed.

Operator splitting method for simulation of dynamic flows in natural gas pipeline networks

DOE PAGES

Dyachenko, Sergey A.; Zlotnik, Anatoly; Korotkevich, Alexander O.; ...

2017-09-19

Here, we develop an operator splitting method to simulate flows of isothermal compressible natural gas over transmission pipelines. The method solves a system of nonlinear hyperbolic partial differential equations (PDEs) of hydrodynamic type for mass flow and pressure on a metric graph, where turbulent losses of momentum are modeled by phenomenological Darcy-Weisbach friction. Mass flow balance is maintained through the boundary conditions at the network nodes, where natural gas is injected or withdrawn from the system. Gas flow through the network is controlled by compressors boosting pressure at the inlet of the adjoint pipe. Our operator splitting numerical scheme ismore » unconditionally stable and it is second order accurate in space and time. The scheme is explicit, and it is formulated to work with general networks with loops. We test the scheme over range of regimes and network configurations, also comparing its performance with performance of two other state of the art implicit schemes.« less

Oil-free centrifugal hydrogen compression technology demonstration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heshmat, Hooshang

2014-05-31

One of the key elements in realizing a mature market for hydrogen vehicles is the deployment of a safe and efficient hydrogen production and delivery infrastructure on a scale that can compete economically with current fuels. The challenge, however, is that hydrogen, being the lightest and smallest of gases with a lower viscosity and density than natural gas, readily migrates through small spaces and is difficult to compresses efficiently. While efficient and cost effective compression technology is crucial to effective pipeline delivery of hydrogen, the compression methods used currently rely on oil lubricated positive displacement (PD) machines. PD compression technologymore » is very costly, has poor reliability and durability, especially for components subjected to wear (e.g., valves, rider bands and piston rings) and contaminates hydrogen with lubricating fluid. Even so called “oil-free” machines use oil lubricants that migrate into and contaminate the gas path. Due to the poor reliability of PD compressors, current hydrogen producers often install duplicate units in order to maintain on-line times of 98-99%. Such machine redundancy adds substantially to system capital costs. As such, DOE deemed that low capital cost, reliable, efficient and oil-free advanced compressor technologies are needed. MiTi’s solution is a completely oil-free, multi-stage, high-speed, centrifugal compressor designed for flow capacity of 500,000 kg/day with a discharge pressure of 1200 psig. The design employs oil-free compliant foil bearings and seals to allow for very high operating speeds, totally contamination free operation, long life and reliability. This design meets the DOE’s performance targets and achieves an extremely aggressive, specific power metric of 0.48 kW-hr/kg and provides significant improvements in reliability/durability, energy efficiency, sealing and freedom from contamination. The multi-stage compressor system concept has been validated through full scale performance testing of a single stage with helium similitude gas at full speed in accordance with ASME PTC-10. The experimental results indicated that aerodynamic performance, with respect to compressor discharge pressure, flow, power and efficiency exceeded theoretical prediction. Dynamic testing of a simulated multistage centrifugal compressor was also completed under a parallel program to validate the integrity and viability of the system concept. The results give strong confidence in the feasibility of the multi-stage design for use in hydrogen gas transportation and delivery from production locations to point of use.« less

Research on Aero-Thermodynamic Distortion Induced Structural Dynamic Response of Multi-Stage Compressor Blading.

DTIC Science & Technology

1988-01-15

However. only very engineering limited experimental data exists to assess the Director, Thermal Sciences and range of validity and to direct the... experimental results of Goldstein et. al. "A 1111 and also the Navier Stokes numerical solutions of Morihara 1121. Diffuser The predicted stream function...Unsteady Aerodynamic Interactions in a Multistage Compressor............................................................ 53 I APPENDIX VI. Experimental

Active magnetic bearings applied to industrial compressors

NASA Technical Reports Server (NTRS)

Kirk, R. G.; Hustak, J. F.; Schoeneck, K. A.

1993-01-01

The design and shop test results are given for a high-speed eight-stage centrifugal compressor supported by active magnetic bearings. A brief summary of the basic operation of active magnetic bearings and the required rotor dynamics analysis are presented with specific attention given to design considerations for optimum rotor stability. The concerns for retrofits of magnetic bearings in existing machinery are discussed with supporting analysis of a four-stage centrifugal compressor. The current status of industrial machinery in North America using this new support system is presented and recommendations are given on design and analysis requirements for successful machinery operation of either retrofit or new design turbomachinery.

78 FR 66355 - Pleasant Grove City, UT; Notice of Preliminary Determination of a Qualifying Conduit Hydropower...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-05

... intake pipe off the existing 12-inch diameter water supply pipeline; (2) a new powerhouse containing one... water into an existing 12-inch water supply pipeline; and (4) appurtenant facilities. The proposed...--Project Blue Energy would utilize Pleasant Grove's water intake pipeline that delivers water to its water...

Accident Prevention and Diagnostics of Underground Pipeline Systems

NASA Astrophysics Data System (ADS)

Trokhimchuk, M.; Bakhracheva, Y.

2017-11-01

Up to forty thousand accidents occur annually with underground pipelines due to corrosion. The comparison of the methods for assessing the quality of anti-corrosion coating is provided. It is proposed to use the device to be tied-in to existing pipeline which has a higher functionality in comparison with other types of the devices due to the possibility of tie-in to the pipelines with different diameters. The existing technologies and applied materials allow us to organize industrial production of the proposed device.

Shock wave boundary layer interaction on suction side of compressor profile in single passage test section

NASA Astrophysics Data System (ADS)

Flaszynski, Pawel; Doerffer, Piotr; Szwaba, Ryszard; Kaczynski, Piotr; Piotrowicz, Michal

2015-11-01

The shock wave boundary layer interaction on the suction side of transonic compressor blade is one of the main objectives of TFAST project (Transition Location Effect on Shock Wave Boundary Layer Interaction). In order to investigate the flow structure on the suction side of a profile, a design of a generic test section in linear transonic wind tunnel was proposed. The experimental and numerical results for the flow structure investigations are shown for the flow conditions as the existing ones on the suction side of the compressor profile. Near the sidewalls the suction slots are applied for the corner flow structure control. It allows to control the Axial Velocity Density Ratio (AVDR), important parameter for compressor cascade investigations. Numerical results for Explicit Algebraic Reynolds Stress Model with transition modeling are compared with oil flow visualization, schlieren and Pressure Sensitive Paint. Boundary layer transition location is detected by Temperature Sensitive Paint.

15 KW Small Turboelectric Power Generation System

DTIC Science & Technology

2006-08-18

1 hour per response, including the time for reviewing instnlctions, searching existing data sources, gathering and maintaining the data needed, and...pressure rise is consistent with data from the baseline compressor and a large body of published diffuser data . Table 1 LTS22 Compressor Preliminary... data on designs of 150 HP, 60 HP, and 5 HP engine size class, and in subsequent engine testing. The design methodology encompasses basic sizing

DSRC 2--Industry-oriented compression of FASTQ files.

PubMed

Roguski, Lukasz; Deorowicz, Sebastian

2014-08-01

Modern sequencing platforms produce huge amounts of data. Archiving them raises major problems but is crucial for reproducibility of results, one of the most fundamental principles of science. The widely used gzip compressor, used for reduction of storage and transfer costs, is not a perfect solution, so a few specialized FASTQ compressors were proposed recently. Unfortunately, they are often impractical because of slow processing, lack of support for some variants of FASTQ files or instability. We propose DSRC 2 that offers compression ratios comparable with the best existing solutions, while being a few times faster and more flexible. DSRC 2 is freely available at http://sun.aei.polsl.pl/dsrc. The package contains command-line compressor, C and Python libraries for easy integration with existing software and technical documentation with examples of usage. sebastian.deorowicz@polsl.pl Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Development of a valved non-lubricated linear compressor for compact 2K Gifford-McMahon cryocoolers

NASA Astrophysics Data System (ADS)

Hiratsuka, Y.; Bao, Q.; Xu, M.

2017-02-01

Recently, a new, compact Gifford-McMahon (GM) cryocooler for cooling superconducting single photon detectors (SSPD) has been developed and reported by Sumitomo Heavy Industries, Ltd. (SHI) [1]. It was reported that National Institute of Information and Communications Technology (NICT) developed a multi-channel SSPD system in which two or more channels were mounted on a GM cryocooler, and achieved a world-top-class performance [2]. However, the applications of such SSPD system were restricted due to its relatively large size and power consumption compared with a semiconductor system. Owing to the development of an SSPD system with a portable cryocooler system which can be installed in a vehicle, it is possible to apply such system to the optical communication of AdHoc [3], and to flexibly construct a large capacity optical line in a time of disaster. For such system, the size and power consumption reduction becomes indispensable. The objective is to reduce the total height of the expander by 33% relative to the existing RDK-101 GM expander and to reduce the total volume of the compressor unit by 50% relative to the existing CNA-11 compressor. In addition, considering the targeted cooling application, we set the design temperature targets of the first and the second stages to 1 W and 20 mW of heat load at 60 K and 2.3 K, respectively. In 2015, Hiratsuka reported that a new valved non-lubricated compressor was developed for a 2K GM cryocooler [4]. The cooling performance of a 2K GM expander operated by an experimental unit of the linear compressor was measured, and preliminary experiments were conducted. No-load temperature was 2.19 K, with 1 W and 14 mW heat load, the temperature was 48 K at the first stage and 2.3 K at the second stage, with an input power of about 1.2 kW. After that, the compressor efficiency has been improved by reducing losses, and the compressor input power has been reduced by 25%. The detailed experimental results are discussed in this paper.

Experimental Investigation on The Electromagnetic Clutch Water pump and Pneumatic Compressor for Improving the Efficiency of an Engine

NASA Astrophysics Data System (ADS)

Kumarasubramanian, R.; Xavier, Goldwin; Nishanthi, W. Mary; Rajasekar, R.

2017-05-01

Considering the fuel crises today many work and research were conducted to reduce the fuel consumption of the internal combustion engine. The fuel consumption of an internal combustion engine can be relatively reduced by use of the electromagnetic clutch water pump and pneumatic compressor. Normally in an engine, the water pump is driven by the crankshaft, with an aid of belt, for the circulation of the water for the cooling process. The circulation of coolant is resisted by the thermostat valve, while the temperature inside the coolant jacket of the engine is below 375K the thermostat is closed only above 375K it tends to open. But water pump run continuously even when thermostat is closed. In pneumatic braking system, pneumatic or air compressor purpose is to compress the air and stored into the storage tank for the brake operation. When the air pressure of the storage tanks gets increases above its storage capacity pressure is regulated by governor, by passing them to atmosphere. Such unnecessary work of this water pump and air compressor can be minimized by use of the electromagnetic clutch water pump and air compressor. The European Driving Cycle is used to evaluate the performance of this water pump and air compressor when used in an engine. The result shows that the fuel economy of the engine while using electromagnetic water pump and pneumatic compressor were improved by 8.0% compared with conventional types which already exist. The application of these electromagnetic water pump and pneumatic compressor are expected to contribute for the improvement of engine performance because of their effect in reduction of the rate of fuel consumption.

Comparisons of sediment losses from a newly constructed cross-country natural gas pipeline and an existing in-road pipeline

Treesearch

Pamela J. Edwards; Bridget M. Harrison; Daniel J. Holz; Karl W.J. Williard; Jon E. Schoonover

2014-01-01

Sediment loads were measured for about one year from natural gas pipelines in two studies in north central West Virginia. One study involved a 1-year-old pipeline buried within the bed of a 25-year-old skid road, and the other involved a newly constructed cross-country pipeline. Both pipelines were the same diameter and were installed using similar trenching and...

75 FR 63462 - Central New York Oil and Gas Company, LLC; Notice of Intent To Prepare an Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

... pipeline infrastructure to receive natural gas produced from Marcellus Shale production areas for delivery to existing interstate pipeline systems of Tennessee Gas Pipeline Company (TGP), CNYOG, and Transcontinental Gas Pipeline Corporation (Transco). It would also provide for bi-directional transportation...

Toward a Real-Time Measurement-Based System for Estimation of Helicopter Engine Degradation Due to Compressor Erosion

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Simo, Donald L.

2007-01-01

This paper presents a preliminary demonstration of an automated health assessment tool, capable of real-time on-board operation using existing engine control hardware. The tool allows operators to discern how rapidly individual turboshaft engines are degrading. As the compressor erodes, performance is lost, and with it the ability to generate power. Thus, such a tool would provide an instant assessment of the engine s fitness to perform a mission, and would help to pinpoint any abnormal wear or performance anomalies before they became serious, thereby decreasing uncertainty and enabling improved maintenance scheduling. The research described in the paper utilized test stand data from a T700-GE-401 turboshaft engine that underwent sand-ingestion testing to scale a model-based compressor efficiency degradation estimation algorithm. This algorithm was then applied to real-time Health Usage and Monitoring System (HUMS) data from a T700-GE-701C to track compressor efficiency on-line. The approach uses an optimal estimator called a Kalman filter. The filter is designed to estimate the compressor efficiency using only data from the engine s sensors as input.

Surge-Inception Study in a Two-Spool Turbojet Engine. Revised

NASA Technical Reports Server (NTRS)

Wallner, Lewis E.; Lubick, Robert J.; Saari, Martin J.

1957-01-01

A two-spool turbojet engine was operated in the Lewis altitude wind tunnel to study the inception of compressor surge. In addition to the usual steady-state pressure and temperature measurements, the compressors were extensively instrumented with fast-response interstage pressure transducers. Thus it was possible to obtain maps for both compressors, pressure oscillations during rotating stall, effects of stall on efficiency, and stage-loading curves. In addition, with the transient measurements, it was possible to record interstage pressures and then compute stage performance during accelerations to the stall limit. Rotating stall was found to exist at low speeds in the outer spool. Although the stall arose from poor flow conditions at the inlet-stage blade tips, the low-energy air moved through the machine from the tip at the inlet to the outer spool to the hub at the inlet to the inner spool. This tip stall ultimately resulted in compressor surge in the mid-speed region, and necessitated inter-compressor air bleed. Interstage pressure measurements during acceleration to the compressor stall limit indicated that rotating stall was not a necessary condition for compressor surge and that, at the critical stall point, the circumferential interstage pressure distribution was uniform. The exit-stage group of the inner spool was first t o stall; then, the stages upstream stalled in succession until the inlet stage of the outer spool was stalled. With a sufficiently high fuel rate, the process repeated with a cycle time of about 0.1 second. It was possible to construct reproducible stage stall lines as a function of compressor speed from the stage stall points of several such compressor surges. This transient stall line was checked by computing the stall line from a steady-state stage-loading curve. Good agreement between the stage stall lines was obtained by these two methods.

Scaled centrifugal compressor, collector and running gear program

NASA Technical Reports Server (NTRS)

Kenehan, J. G.

1983-01-01

The Scaled Centrifugal Compressor, Collector and Running gear Program was conducted in support of an overall NASA strategy to improve small-compressor performance, durability, and reliability while reducing initial and life-cycle costs. Accordingly, Garrett designed and provided a test rig, gearbox coupling, and facility collector for a new NASA facility, and provided a scaled model of an existing, high-performance impeller for evaluation scaling effects on aerodynamic performance and for obtaining other performance data. Test-rig shafting was designed to operate smoothly throughout a speed range up to 60,000 rpm. Pressurized components were designed to operate at pressures up to 300 psia and at temperatures to 1000 F. Nonrotating components were designed to provide a margin-of-safety of 0.05 or greater; rotating components, for a margin-of-safety based on allowable yield and ultimate strengths. Design activities were supported by complete design analysis, and the finished hardware was subjected to check-runs to confirm proper operation. The test rig will support a wide range of compressor tests and evaluations.

Numerical investigation of a centrifugal compressor with circumferential grooves in vane diffuser

NASA Astrophysics Data System (ADS)

Chen, X. F.; Qin, G. L.; Ai, Z. J.

2015-08-01

Enhancing stall and surge margin has a great importance for the development of turbo compressors. The application of casing treatment is an effective measure to expand the stall margin and stable operation range. Numerical investigations were conducted to predict the performance of a low flow rate centrifugal compressor with circumferential groove casing treatment in vane diffuser. Numerical cases with different radial location, radial width and axial depth of a circumferential single groove and different numbers of circumferential grooves were carried out to compare the results. The CFD analyses results show that the centrifugal compressor with circumferential grooves in diffuser can extend stable range by about 9% while the efficiency over the whole operating range decreases by 0.2 to 1.7%. The evaluation based on stall margin improvement showed the optimal position for the groove to be located was indicated to exist near the leading edge of the diffuser, and a combination of position, width, depth and numbers of circumferential grooves that will maximize both surge margin range and efficiency.

78 FR 75557 - CE FLNG, LLC, CE Pipeline, LLC; Notice of Intent To Prepare an Environmental Impact Statement for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-12

... acquisition of an easement to construct, operate, and maintain the natural gas transmission pipeline...-diameter natural gas transmission pipeline in Plaquemines Parish, Louisiana. The LNG terminal would be... port. The planned transmission pipeline would connect the terminal to existing natural gas...

78 FR 15715 - Excelerate Liquefaction Solutions I, LLC; Lavaca Bay Pipeline System, LLC; Notice of Intent To...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-12

... natural gas from existing pipeline systems to the LNG terminal facilities. The Project would be... room, warehouse, and shop. Pipeline Header System: A 29-mile-long, 42-inch-diameter natural gas pipeline extending northward from the shoreside facilities to nine natural gas interconnects southwest of...

49 CFR 195.11 - What is a regulated rural gathering line and what requirements apply?

Code of Federal Regulations, 2011 CFR

2011-10-01

... subpart H of this part, except corrosion control is not required for pipelines existing on July 3, 2008... (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE General § 195.11 What is a regulated rural...

49 CFR 195.11 - What is a regulated rural gathering line and what requirements apply?

Code of Federal Regulations, 2010 CFR

2010-10-01

... subpart H of this part, except corrosion control is not required for pipelines existing on July 3, 2008... (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE General § 195.11 What is a regulated rural...

Subsynchronous instability of a geared centrifugal compressor of overhung design

NASA Technical Reports Server (NTRS)

Hudson, J. H.; Wittman, L. J.

1980-01-01

The original design analysis and shop test data are presented for a three stage (poster) air compressor with impellers mounted on the extensions of a twin pinion gear, and driven by an 8000 hp synchronous motor. Also included are field test data, subsequent rotor dynamics analysis, modifications, and final rotor behavior. A subsynchronous instability existed on a geared, overhung rotor. State-of-the-art rotor dynamics analysis techniques provided a reasonable analytical model of the rotor. A bearing modification arrived at analytically eliminated the instability.

Active control of surge in centrifugal compressors using magnetic thrust bearing actuation

NASA Astrophysics Data System (ADS)

Sanadgol, Dorsa

This research presents a new method for active surge control in centrifugal compressors with unshrouded impellers using a magnetic thrust bearing to modulate the impeller tip clearance. Magnetic bearings offer the potential for active control of flow instabilities. This capability is highly dependent on the sensitivity of the compressor characteristics to blade tip clearance. If the position of the shaft can be actuated with sufficient authority and speed, the induced pressure modulation makes control of surge promising. The active nature of the magnetic bearing system makes the real-time static and dynamic positioning of the rotor and therefore modulation of the impeller tip clearance possible. A theoretical model is first established that describes the sensitivity of the centrifugal compressor characteristic curve to tip clearance variations induced by axial motion of the rotor. Results from simulation of the nonlinear model for a single stage high-speed centrifugal compressor show that using the proposed control method, mass flow and pressure oscillations associated with compressor surge are quickly suppressed with acceptable tip clearance excursions, typically less than 20% of the available clearance. It is shown that it is possible to produce adequate axial excursions in the clearance between the impeller blades and the adjacent stationary shroud using a magnetic thrust bearing with practical levels of drive voltage. This surge control method would allow centrifugal compressors to reliably and safely operate with a wider range than is currently done in the field. The principal advantage of the proposed approach over conventional surge control methods lies in that, in machines already equipped with magnetic bearing, the method can potentially be implemented by simply modifying controller software. This dispenses with the need to introduce additional hardware, permitting adaptation of existing machinery at virtually no cost. In addition, since the controller is designed with the objective of keeping the trajectories on the compressor characteristic curve, the compressor performance and efficiency are no longer sacrificed by excessive recycling to achieve stability. In order to explore these conjectures experimentally, a high speed centrifugal compressor test facility with active magnetic bearings is developed. The test facility can be used for implementing the proposed surge control method and also for assessing the impeller and bearing loads at off-design conditions. This data can then be used to verify and refine analytical models used in compressor design. (Abstract shortened by UMI.)

Pipeline systems - safety for assets and transport regularity

DOT National Transportation Integrated Search

1997-01-01

This review regarding safety for assets and financial interests for pipeline systems has showed how this aspect has been taken care of in the existing petroleum legislation. It has been demonstrated that the integrity of pipeline systems with the res...

Developpement dune methode de simulation de pompage au sein d'un compresseur multi-etage

NASA Astrophysics Data System (ADS)

Dumas, Martial

Surge is an unsteady phenomenon which appears when a compressor operates at a mass flow that is too low relative to its design point. This aerodynamic instability is characterized by large oscillations in pressure and mass flow, resulting in a sudden drop in power delivered by a gas turbine engine and possibly important damage to engine components. The methodology developed in this thesis allows for the simulations of the flow behavior inside a multi-stage compressor during surge and, by extension, predict at the design phase the time variation of aerodynamic forces on the blades and of the pressure and temperature at bleed locations inside the compressors for turbine cooling. While the compressor is the component of interest and the trigger for surge, the flow behavior during this event is also dependent on other engine components (combustion chamber, turbine, ducts). However, the simulation of the entire gas turbine engine cannot be carried out in a practical manner with existing computational technologies. The approach taken consists of coupling 3-D RANS CFD simulations of the compressor with 1-D equations modeling the behavior of the other components applied as dynamic boundary conditions. The method was put into practice in a commercial RANS CFD code (ANSYS CFX) whose integrated options facilitated the implementation of the 1-D equations into the dynamic boundary conditions of the computational domain. In addition, in order to limit computational time, only one blade passage was simulated per blade row to capture surge which is essentially a one-dimensional phenomenon. This methodology was applied to several compressor geometries with distinct features. Simulations on a low-speed (incompressible) three-stage axial compressor allowed for a validation with experimental data, which showed that the pressure and mass flow oscillations are captured well. This comparison also highlighted the strong dependence of the oscillation frequency on the volume of the downstream plenum (combustion chamber). The simulations of the second compressor demonstrated the adaptability of the approach to a multi-stage compressor with an axial-centrifugal configuration. Finally, application of the method to a transonic compressor geometry from Pratt & Whitney Canada demonstrated the tool on a mixed flow-centrifugal compressor configuration operating in a highly compressible regime. These last simulations highlighted certain limitations of the tool, namely the numerical robustness associated with the use of multiple stator/rotor interfaces in a high-speed compressor with high rates of change of mass flow, and the computational time required to a simulate several surge cycles.

Determine the Requirements for Existing Pipeline, Tank and Terminal Systems to Transport Ethanol without Cracking

DOT National Transportation Integrated Search

2010-06-18

The potential exists for stress corrosion cracking (SCC) of carbon steel pipelines transporting fuel grade ethanol (FGE) and FGE- gasoline blends. The objectives of SCC 4-4 were to: 1. Develop data necessary to make engineering assessments of the fea...

Computational analysis of stall and separation control in centrifugal compressors

NASA Astrophysics Data System (ADS)

Stein, Alexander

2000-10-01

A numerical technique for simulating unsteady viscous fluid flow in turbomachinery components has been developed. In this technique, the three-dimensional form of the Reynolds averaged Navier-Stokes equations is solved in a time-accurate manner. The flow solver is used to study fluid dynamic phenomena that lead to instabilities in centrifugal compressors. The results indicate that large flow incidence angles, at reduced flow rates, can cause boundary layer separation near the blade leading edge. This mechanism is identified as the primary factor in the stall inception process. High-pressure jets upstream of the compressor face are studied as a means of controlling compressor instabilities. Steady jets are found to alter the leading edge flow pattern and effectively suppress compressor instabilities. Yawed jets are more effective than parallel jets and an optimum yaw angle exists for each compression system. Numerical simulations utilizing pulsed jets have also been done. Pulsed jets are found to yield additional performance enhancements and lead to a reduction in external air requirements for operating the jets. Jets pulsed at higher frequencies perform better than low-frequency jets. These findings suggest that air injection is a viable means of alleviating compressor instabilities and could impact gas turbine technology. Results concerning the optimization of practical air injection systems and implications for future research are discussed. The flow solver developed in this work, along with the postprocessing tools developed to interpret the results, provide a rational framework for analyzing and controlling current and next generation compression systems.

The Integration of an API619 Screw Compressor Package into the Industrial Internet of Things

NASA Astrophysics Data System (ADS)

Milligan, W. J.; Poli, G.; Harrison, D. K.

2017-08-01

The Industrial Internet of Things (IIoT) is the industrial subset of the Internet of Things (IoT). IIoT incorporates big data technology, harnessing the instrumentation data, machine to machine communication and automation technologies that have existed in industrial settings for years. As industry in general trends towards the IIoT and as the screw compressor packages developed by Howden Compressors are designed with a minimum design life of 25 years, it is imperative this technology is embedded immediately. This paper provides the reader with a description on the Industrial Internet of Things before moving onto describing the scope of the problem for an organisation like Howden Compressors who deploy multiple compressor technologies across multiple locations and focuses on the critical measurements particular to high specification screw compressor packages. A brief analysis of how this differs from high volume package manufacturers deploying similar systems is offered. Then follows a description on how the measured information gets from the tip of the instrument in the process pipework or drive train through the different layers, with a description of each layer, into the final presentation layer. The functions available within the presentation layer are taken in turn and the benefits analysed with specific focus on efficiency and availability. The paper concludes with how packagers adopting the IIoT can not only optimise their package but by utilising the machine learning technology and pattern detection applications can adopt completely new business models.

The MEMS Knudsen Compressor as a Vacuum Pump for Space Exploration Applications

NASA Technical Reports Server (NTRS)

Vargo, S. E.; Muntz, E. P.; Tang, W. C.

2000-01-01

Several lander, probe and rover missions currently under study at the Jet Propulsion Laboratory (JPL) and especially in the Microdevices Laboratory (MDL) Center for Space Microelectronics Technology, focus on utilizing microelectromechanical systems (MEMS) based instruments for science data gathering. These small instruments and NASA's commitment to "faster, better, cheaper" type missions has brought about the need for novel approaches to satisfying mission requirements. Existing in-situ instrument systems clearly lack novel and integrated methods for satisfying their vacuum needs. One attractive candidate for a MEMS vacuum pump is the Knudsen Compressor, which operates based on thermal transpiration. Thermal transpiration describes gas flows induced by temperature differences maintained across orifices, porous membranes or capillary tubes under rarefied conditions. This device has two overwhelmingly attractive features as a MEMS vacuum pump - no moving parts and no fluids. An initial estimate of a Knudsen Compressor's pumping power requirements for a surface atmospheric sampling task on Mars is less than 80 mW, significantly below than alternative pumps. Due to the relatively low energy use for this task and the applicability of the Knudsen Compressor to other applications, the development of a Knudsen Compressor utilizing MEMS fabrication techniques has been initiated. This paper discusses the initial fabrication of a single-stage MEMS Knudsen Compressor vacuum pump, provides performance criteria such as pumping speed, size, energy use and ultimate pressure and details vacuum pump applications in several MDL related in-situ instruments.

Large eddy simulation of flows in industrial compressors: a path from 2015 to 2035

PubMed Central

Gourdain, N.; Sicot, F.; Duchaine, F.; Gicquel, L.

2014-01-01

A better understanding of turbulent unsteady flows is a necessary step towards a breakthrough in the design of modern compressors. Owing to high Reynolds numbers and very complex geometry, the flow that develops in such industrial machines is extremely hard to predict. At this time, the most popular method to simulate these flows is still based on a Reynolds-averaged Navier–Stokes approach. However, there is some evidence that this formalism is not accurate for these components, especially when a description of time-dependent turbulent flows is desired. With the increase in computing power, large eddy simulation (LES) emerges as a promising technique to improve both knowledge of complex physics and reliability of flow solver predictions. The objective of the paper is thus to give an overview of the current status of LES for industrial compressor flows as well as to propose future research axes regarding the use of LES for compressor design. While the use of wall-resolved LES for industrial multistage compressors at realistic Reynolds number should not be ready before 2035, some possibilities exist to reduce the cost of LES, such as wall modelling and the adaptation of the phase-lag condition. This paper also points out the necessity to combine LES to techniques able to tackle complex geometries. Indeed LES alone, i.e. without prior knowledge of such flows for grid construction or the prohibitive yet ideal use of fully homogeneous meshes to predict compressor flows, is quite limited today. PMID:25024422

Smart actuation of inlet guide vanes for small turbine engine

NASA Astrophysics Data System (ADS)

Rusovici, Razvan; Kwok Choon, Stephen T.; Sepri, Paavo; Feys, Joshuo

2011-04-01

Unmanned Aerial Vehicles (UAVs) have gained popularity over the past few years to become an indispensable part of aerial missions that include reconnaissance, surveillance, and communication [1]. As a result, advancements in small jet-engine performance are needed to increase the performance (range, payload and efficiency) of the UAV. These jet engines designed especially for UAV's are characterized by thrust force on the order of 100N and due to their size and weight limitations, may lack advanced flow control devices such as IGV [2]. The goal of the current study was to present a conceptual design of an IGV smart-material based actuation mechanism that would be simple, compact and lightweight. The compressor section of an engine increases the pressure and conditions the flow before the air enters the combustion chamber [3]. The airflow entering the compressor is often turbulent due to the high angle of incidence between engine inlet and free-stream velocity, or existing atmospheric turbulence. Actuated IGV are used to help control the relative angle of incidence of the flow that enters the engine compressor, thereby preventing flow separation, compressor stall and thus extending the compressor's operating envelope [4]. Turbine jet- engines which employ variable IGV were developed by Rolls Royce (Trent DR-900) and General Electric (J79).

Discrete pre-processing step effects in registration-based pipelines, a preliminary volumetric study on T1-weighted images.

PubMed

Muncy, Nathan M; Hedges-Muncy, Ariana M; Kirwan, C Brock

2017-01-01

Pre-processing MRI scans prior to performing volumetric analyses is common practice in MRI studies. As pre-processing steps adjust the voxel intensities, the space in which the scan exists, and the amount of data in the scan, it is possible that the steps have an effect on the volumetric output. To date, studies have compared between and not within pipelines, and so the impact of each step is unknown. This study aims to quantify the effects of pre-processing steps on volumetric measures in T1-weighted scans within a single pipeline. It was our hypothesis that pre-processing steps would significantly impact ROI volume estimations. One hundred fifteen participants from the OASIS dataset were used, where each participant contributed three scans. All scans were then pre-processed using a step-wise pipeline. Bilateral hippocampus, putamen, and middle temporal gyrus volume estimations were assessed following each successive step, and all data were processed by the same pipeline 5 times. Repeated-measures analyses tested for a main effects of pipeline step, scan-rescan (for MRI scanner consistency) and repeated pipeline runs (for algorithmic consistency). A main effect of pipeline step was detected, and interestingly an interaction between pipeline step and ROI exists. No effect for either scan-rescan or repeated pipeline run was detected. We then supply a correction for noise in the data resulting from pre-processing.

Pipeline corridors through wetlands - impacts on plant communities: Bayou Pointe Aux Chenes, Terrebonne Parish, Louisiana. Topical report, August 1991--April 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Dyke, G.D.; Shem, L.M.; Zimmerman, R.E.

1994-12-01

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipelines on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and night- of-way management practices. This report presents the results of a survey conducted on August 22, 1991, in an emergent intertidal estuarine wetland in Terrebonne Parish, Louisiana. The site includes three pipelines installed between 1958 and 1969. Vegetation within the site comprises three native tidal marsh grasses: Spartina alterniflora, Spartina patens, and Distichlismore » spicata. All three species occurred over the pipelines, within the right-of-way and in both natural areas. Vegetative differences attributable to the installation or presence of the pipelines were not obvious over the pipelines or in the habitat east of the pipelines. However, because of the presence of a canal west of the 1969 pipeline, vegetation was less abundant in that area, and D. spicata was absent from all but the most distant plots of the transacts. Data obtained in the study indicate that when rights-of-way through brackish marsh are restored to their original elevations, they are revegetated with native vegetation similar to that in surrounding areas.« less

75 FR 17825 - Request for Public Comments and OMB Approval of Existing Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No...: Pipeline and Hazardous Materials Safety Administration. ACTION: Request for Public Comments and OMB... Reduction Act of 1995, the Pipeline and Hazardous Materials Safety Administration (PHMSA) published a notice...

A pilot study to assess residential noise exposure near natural gas compressor stations.

PubMed

Boyle, Meleah D; Soneja, Sutyajeet; Quirós-Alcalá, Lesliam; Dalemarre, Laura; Sapkota, Amy R; Sangaramoorthy, Thurka; Wilson, Sacoby; Milton, Donald; Sapkota, Amir

2017-01-01

U.S. natural gas production increased 40% from 2000 to 2015. This growth is largely related to technological advances in horizontal drilling and high-volume hydraulic fracturing. Environmental exposures upon impacted communities are a significant public health concern. Noise associated with natural gas compressor stations has been identified as a major concern for nearby residents, though limited studies exist. We conducted a pilot study to characterize noise levels in 11 homes located in Doddridge County, West Virginia, and determined whether these levels differed based on time of day, indoors vs. outdoors, and proximity of homes to natural gas compressor stations. We also compared noise levels at increasing distances from compressor stations to available noise guidelines, and evaluated low frequency noise presence. We collected indoor and outdoor 24-hour measurements (Leq, 24hr) in eight homes located within 750 meters (m) of the nearest compressor station and three control homes located >1000m. We then evaluated how A-weighted decibel (dBA) exposure levels differed based on factors outlined above. The geometric mean (GM) for 24-hour outdoor noise levels at homes located <300m (Leq,24hr: 60.3 dBA; geometric standard deviation (GSD): 1.0) from the nearest compressor station was nearly 9 dBA higher than control homes (Leq,24hr: 51.6 dBA; GSD: 1.1). GM for 24 hour indoor noise for homes <300m (Leq,24hr: 53.4 dBA; GSD: 1.2) from the nearest compressor station was 11.2 dBA higher than control homes (Leq,24hr: 42.2 dBA; GSD: 1.1). Indoor average daytime noise for homes <300m of the nearest compressor stations were 13.1 dBA higher than control homes, while indoor nighttime readings were 9.4 dBA higher. Findings indicate that living near a natural gas compressor station could potentially result in high environmental noise exposures. Larger studies are needed to confirm these findings and evaluate potential health impacts and protection measures.

A pilot study to assess residential noise exposure near natural gas compressor stations

PubMed Central

Boyle, Meleah D.; Quirós-Alcalá, Lesliam; Dalemarre, Laura; Sapkota, Amy R.; Sangaramoorthy, Thurka; Wilson, Sacoby; Milton, Donald; Sapkota, Amir

2017-01-01

Background U.S. natural gas production increased 40% from 2000 to 2015. This growth is largely related to technological advances in horizontal drilling and high-volume hydraulic fracturing. Environmental exposures upon impacted communities are a significant public health concern. Noise associated with natural gas compressor stations has been identified as a major concern for nearby residents, though limited studies exist. Objectives We conducted a pilot study to characterize noise levels in 11 homes located in Doddridge County, West Virginia, and determined whether these levels differed based on time of day, indoors vs. outdoors, and proximity of homes to natural gas compressor stations. We also compared noise levels at increasing distances from compressor stations to available noise guidelines, and evaluated low frequency noise presence. Methods We collected indoor and outdoor 24-hour measurements (Leq, 24hr) in eight homes located within 750 meters (m) of the nearest compressor station and three control homes located >1000m. We then evaluated how A-weighted decibel (dBA) exposure levels differed based on factors outlined above. Results The geometric mean (GM) for 24-hour outdoor noise levels at homes located <300m (Leq,24hr: 60.3 dBA; geometric standard deviation (GSD): 1.0) from the nearest compressor station was nearly 9 dBA higher than control homes (Leq,24hr: 51.6 dBA; GSD: 1.1). GM for 24 hour indoor noise for homes <300m (Leq,24hr: 53.4 dBA; GSD: 1.2) from the nearest compressor station was 11.2 dBA higher than control homes (Leq,24hr: 42.2 dBA; GSD: 1.1). Indoor average daytime noise for homes <300m of the nearest compressor stations were 13.1 dBA higher than control homes, while indoor nighttime readings were 9.4 dBA higher. Conclusions Findings indicate that living near a natural gas compressor station could potentially result in high environmental noise exposures. Larger studies are needed to confirm these findings and evaluate potential health impacts and protection measures. PMID:28369113

A theory of rotating stall of multistage axial compressors

NASA Technical Reports Server (NTRS)

Moore, F. K.

1983-01-01

A theoretical analysis was made of rotating stall in axial compressors of many stages, finding conditions for a permanent, straight-through traveling disturbance, with the steady compressor characteristic assumed known, and with simple lag processes ascribed to the flows in the inlet, blade passages, and exit regions. For weak disturbances, predicted stall propagation speeds agree well with experimental results. For a locally-parabolic compressor characteristic, an exact nonlinear solution is found and discussed. For deep stall, the stall-zone boundary is most abrupt at the trailing edge, as expected. When a complete characteristic having unstalling and reverse-flow features is adopted, limit cycles governed by a Lienard's equation are found. Analysis of these cycles yields predictions of recovery from rotating stall; a relaxation oscillation is found at some limiting flow coefficient, above which no solution exists. Recovery is apparently independent of lag processes in the blade passages, but instead depends on the lags originating in the inlet and exit flows, and also on the shape of the given characteristic diagram. Small external lags and tall diagrams favor early recovery. Implications for future research are discussed.

Blending Hydrogen into Natural Gas Pipeline Networks: A Review of Key Issues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melaina, M. W.; Antonia, O.; Penev, M.

2013-03-01

The United States has 11 distinct natural gas pipeline corridors: five originate in the Southwest, four deliver natural gas from Canada, and two extend from the Rocky Mountain region. This study assesses the potential to deliver hydrogen through the existing natural gas pipeline network as a hydrogen and natural gas mixture to defray the cost of building dedicated hydrogen pipelines.

Manifold Coal-Slurry Transport System

NASA Technical Reports Server (NTRS)

Liddle, S. G.; Estus, J. M.; Lavin, M. L.

1986-01-01

Feeding several slurry pipes into main pipeline reduces congestion in coal mines. System based on manifold concept: feeder pipelines from each working entry joined to main pipeline that carries coal slurry out of panel and onto surface. Manifold concept makes coal-slurry haulage much simpler than existing slurry systems.

75 FR 39230 - Combined Notice of Filings

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-08

.... Take notice that the Commission has received the following Natural Gas Pipeline Rate and Refund Report..., July 12, 2010. Docket Numbers: RP10-908-000. Applicants: Natural Gas Pipeline Company of America. Description: Natural Gas Pipeline Company of America LLC submits an existing negotiated rate agreement. Filed...

Laminar-turbulent transition tripped by step on transonic compressor profile

NASA Astrophysics Data System (ADS)

Flaszynski, Pawel; Doerffer, Piotr; Szwaba, Ryszard; Piotrowicz, Michal; Kaczynski, Piotr

2018-02-01

The shock wave boundary layer interaction on the suction side of transonic compressor blade is one of the main objectives of TFAST project (Transition Location Effect on Shock Wave Boundary Layer Interaction). The experimental and numerical results for the flow structure investigations are shown for the flow conditions as the existing ones on the suction side of the compressor profile. The two cases are investigated: without and with boundary layer tripping device. In the first case, boundary layer is laminar up to the shock wave, while in the second case the boundary layer is tripped by the step. Numerical results carried out by means of Fine/Turbo Numeca with Explicit Algebraic Reynolds Stress Model including transition modeling are compared with schlieren, Temperature Sensitive Paint and wake measurements. Boundary layer transition location is detected by Temperature Sensitive Paint.

Comparisons of Rig and Engine Dynamic Events in the Compressor of an Axi-Centrifugal Turboshaft Engine

NASA Technical Reports Server (NTRS)

Owen, A. Karl; Mattern, Duane L.; Le, Dzu K.

1996-01-01

Steady state and dynamic data were acquired in a T55-L-712 compressor rig. In addition, a T55-L-12 engine was instrumented and similar data were acquired. Rig and engine stall/surge data were analyzed using modal techniques. This paper compares rig and engine preliminary results for the ground idle (approximately 60% of design speed) point. The results of these analyses indicate both rig and engine dynamic event are preceded by indications of traveling wave energy in front of the compressor face. For both rig and engine, the traveling wave energy contains broad band energy with some prominent narrow peaks and, while the events are similar in many ways, some noticeable differences exist between the results of the analyses of rig data and engine data.

Multiple pure tone noise generated by fans at supersonic tip speeds

NASA Technical Reports Server (NTRS)

Sofrin, T. G.; Pickett, G. F.

1974-01-01

The existence of clusters of pure tones at integral multiples of shaft speed has been noted for supersonic-tip-speed operation of fans and compressors. A continuing program to explore this phenomenon, often called combination-tone noise, has been in effect for several years. This paper reviews the research program, which involves a wide range of engines, compressor rigs, and special apparatus. Elements of the aerodynamics of the blade-associated shock waves are outlined and causes of blade-to-blade shock inequalities, responsible for the multiple tones, are described.

78 FR 18970 - Trunkline LNG Company, LLC; Trunkline LNG Export, LLC; Trunkline Gas Company, LLC; Supplemental...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-28

... include plans to construct and modify certain pipeline facilities to supply natural gas to the..., Louisiana to supply natural gas to the liquefaction facility from existing gas transmission pipelines... greenfield natural gas pipeline (Mainline Connector) in Jefferson Davis and Calcasieu Parishes, Louisiana...

The SCUBA Data Reduction Pipeline: ORAC-DR at the JCMT

NASA Astrophysics Data System (ADS)

Jenness, Tim; Economou, Frossie

The ORAC data reduction pipeline, developed for UKIRT, has been designed to be a completely general approach to writing data reduction pipelines. This generality has enabled the JCMT to adapt the system for use with SCUBA with minimal development time using the existing SCUBA data reduction algorithms (Surf).

Discrete pre-processing step effects in registration-based pipelines, a preliminary volumetric study on T1-weighted images

PubMed Central

2017-01-01

Pre-processing MRI scans prior to performing volumetric analyses is common practice in MRI studies. As pre-processing steps adjust the voxel intensities, the space in which the scan exists, and the amount of data in the scan, it is possible that the steps have an effect on the volumetric output. To date, studies have compared between and not within pipelines, and so the impact of each step is unknown. This study aims to quantify the effects of pre-processing steps on volumetric measures in T1-weighted scans within a single pipeline. It was our hypothesis that pre-processing steps would significantly impact ROI volume estimations. One hundred fifteen participants from the OASIS dataset were used, where each participant contributed three scans. All scans were then pre-processed using a step-wise pipeline. Bilateral hippocampus, putamen, and middle temporal gyrus volume estimations were assessed following each successive step, and all data were processed by the same pipeline 5 times. Repeated-measures analyses tested for a main effects of pipeline step, scan-rescan (for MRI scanner consistency) and repeated pipeline runs (for algorithmic consistency). A main effect of pipeline step was detected, and interestingly an interaction between pipeline step and ROI exists. No effect for either scan-rescan or repeated pipeline run was detected. We then supply a correction for noise in the data resulting from pre-processing. PMID:29023597

Pipeline corridors through wetlands -- Impacts on plant communities: Little Timber Creek Crossing, Gloucester County, New Jersey. Topical report, August 1991--January 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shem, L.M.; Zimmerman, R.E.; Alsum, S.K.

1994-12-01

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipelines on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and right-of-way (ROW) management practices. This report presents results of a survey conducted over the period of August 5--7, 1991, at the Little Timber Creek crossing in Gloucester County, New Jersey, where three pipelines, constructed in 1950, 1960, and 1990, cross the creek and associated wetlands. The old side of the ROW, created bymore » the installation of the 1960 pipeline, was designed to contain a raised peat bed over the 1950 pipeline and an open-water ditch over the 1960 pipeline. The new portion of the ROW, created by installation of the 1990 pipeline, has an open-water ditch over the pipeline (resulting from settling of the backfill) and a raised peat bed (resulting from rebound of compacted peat). Both the old and new ROWs contain dense stands of herbs; the vegetation on the old ROW was more similar to that in the adjacent natural area than was vegetation in the new ROW. The ROW increased species and habitat diversity in the wetlands. It may contribute to the spread of purple loosestrife and affect species sensitive to habitat fragmentation.« less

Optimization problems in natural gas transportation systems. A state-of-the-art review

DOE PAGES

Ríos-Mercado, Roger Z.; Borraz-Sánchez, Conrado

2015-03-24

Our paper provides a review on the most relevant research works conducted to solve natural gas transportation problems via pipeline systems. The literature reveals three major groups of gas pipeline systems, namely gathering, transmission, and distribution systems. In this work, we aim at presenting a detailed discussion of the efforts made in optimizing natural gas transmission lines.There is certainly a vast amount of research done over the past few years on many decision-making problems in the natural gas industry and, specifically, in pipeline network optimization. In this work, we present a state-of-the-art survey focusing on specific categories that include short-termmore » basis storage (line-packing problems), gas quality satisfaction (pooling problems), and compressor station modeling (fuel cost minimization problems). We also discuss both steady-state and transient optimization models highlighting the modeling aspects and the most relevant solution approaches known to date. Although the literature on natural gas transmission system problems is quite extensive, this is, to the best of our knowledge, the first comprehensive review or survey covering this specific research area on natural gas transmission from an operations research perspective. Furthermore, this paper includes a discussion of the most important and promising research areas in this field. Hence, our paper can serve as a useful tool to gain insight into the evolution of the many real-life applications and most recent advances in solution methodologies arising from this exciting and challenging research area of decision-making problems.« less

Optimization problems in natural gas transportation systems. A state-of-the-art review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ríos-Mercado, Roger Z.; Borraz-Sánchez, Conrado

Our paper provides a review on the most relevant research works conducted to solve natural gas transportation problems via pipeline systems. The literature reveals three major groups of gas pipeline systems, namely gathering, transmission, and distribution systems. In this work, we aim at presenting a detailed discussion of the efforts made in optimizing natural gas transmission lines.There is certainly a vast amount of research done over the past few years on many decision-making problems in the natural gas industry and, specifically, in pipeline network optimization. In this work, we present a state-of-the-art survey focusing on specific categories that include short-termmore » basis storage (line-packing problems), gas quality satisfaction (pooling problems), and compressor station modeling (fuel cost minimization problems). We also discuss both steady-state and transient optimization models highlighting the modeling aspects and the most relevant solution approaches known to date. Although the literature on natural gas transmission system problems is quite extensive, this is, to the best of our knowledge, the first comprehensive review or survey covering this specific research area on natural gas transmission from an operations research perspective. Furthermore, this paper includes a discussion of the most important and promising research areas in this field. Hence, our paper can serve as a useful tool to gain insight into the evolution of the many real-life applications and most recent advances in solution methodologies arising from this exciting and challenging research area of decision-making problems.« less

Users manual for updated computer code for axial-flow compressor conceptual design

NASA Technical Reports Server (NTRS)

Glassman, Arthur J.

1992-01-01

An existing computer code that determines the flow path for an axial-flow compressor either for a given number of stages or for a given overall pressure ratio was modified for use in air-breathing engine conceptual design studies. This code uses a rapid approximate design methodology that is based on isentropic simple radial equilibrium. Calculations are performed at constant-span-fraction locations from tip to hub. Energy addition per stage is controlled by specifying the maximum allowable values for several aerodynamic design parameters. New modeling was introduced to the code to overcome perceived limitations. Specific changes included variable rather than constant tip radius, flow path inclination added to the continuity equation, input of mass flow rate directly rather than indirectly as inlet axial velocity, solution for the exact value of overall pressure ratio rather than for any value that met or exceeded it, and internal computation of efficiency rather than the use of input values. The modified code was shown to be capable of computing efficiencies that are compatible with those of five multistage compressors and one fan that were tested experimentally. This report serves as a users manual for the revised code, Compressor Spanline Analysis (CSPAN). The modeling modifications, including two internal loss correlations, are presented. Program input and output are described. A sample case for a multistage compressor is included.

76 FR 60478 - Record of Decision, Texas Clean Energy Project

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-29

... the plant with one or both of the nearby power grids; process water supply pipelines; a natural gas... per year. The CO 2 will be delivered through a regional pipeline network to existing oil fields in the... proposed Fort Stockton Holdings water supply pipeline; Possible changes in discharges to Monahans Draw and...

77 FR 4803 - Dominion Transmission, Inc.; Notice of Intent to Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-31

...) existing Sabinsville Meter Station and running south across portions of Clymer, Gaines, and Elk Townships..., Pennsylvania; Replacement of regulators and upgrade of monitor controls at the existing Boom Compressor Station... Station in Stewardson Township, Potter County, Pennsylvania; Installation of about 900 feet of new 24-inch...

United States petroleum pipelines: An empirical analysis of pipeline sizing

NASA Astrophysics Data System (ADS)

Coburn, L. L.

1980-12-01

The undersizing theory hypothesizes that integrated oil companies have a strong economic incentive to size the petroleum pipelines they own and ship over in a way that means that some of the demand must utilize higher cost alternatives. The DOJ theory posits that excess or monopoly profits are earned due to the natural monopoly characteristics of petroleum pipelines and the existence of market power in some pipelines at either the upstream or downstream market. The theory holds that independent petroleum pipelines owned by companies not otherwise affiliated with the petroleum industry (independent pipelines) do not have these incentives and all the efficiencies of pipeline transportation are passed to the ultimate consumer. Integrated oil companies on the other hand, keep these cost efficiencies for themselves in the form of excess profits.

Experimental Investigation of Inlet Distortion in a Multistage Axial Compressor

NASA Astrophysics Data System (ADS)

Rusu, Razvan

The primary objective of this research is to present results and methodologies used to study total pressure inlet distortion in a multi-stage axial compressor environment. The study was performed at the Purdue 3-Stage Axial Compressor Facility (P3S) which models the final three stages of a production turbofan engine's high-pressure compressor (HPC). The goal of this study was twofold; first, to design, implement, and validate a circumferentially traversable total pressure inlet distortion generation system, and second, to demonstrate data acquisition methods to characterize the inter-stage total pressure flow fields to study the propagation and attenuation of a one-per-rev total pressure distortion. The datasets acquired for this study are intended to support the development and validation of novel computational tools and flow physics models for turbomachinery flow analysis. Total pressure inlet distortion was generated using a series of low-porosity wire gauze screens placed upstream of the compressor in the inlet duct. The screens are mounted to a rotatable duct section that can be precisely controlled. The P3S compressor features fixed instrumentation stations located at the aerodynamic interface plane (AIP) and downstream and upstream of each vane row. Furthermore, the compressor features individually indexable stator vanes which can be traverse by up to two vane passages. Using a series of coordinated distortion and vane traverses, the total pressure flow field at the AIP and subsequent inter-stage stations was characterized with a high circumferential resolution. The uniformity of the honeycomb carrier was demonstrated by characterizing the flow field at the AIP while no distortion screens where installed. Next, the distortion screen used for this study was selected following three iterations of porosity reduction. The selected screen consisted of a series of layered screens with a 100% radial extent and a 120° circumferential extent. A detailed total pressure flow field characterization of the AIP was performed using the selected screen at nominal, low, and high compressor loading. Thermal anemometry was used to characterize the spatial variation in turbulence intensity at the AIP in an effort to further define inlet boundary conditions for future computational investigations. Two data acquisition methods for the study of distortion propagation and attenuation were utilized in this study. The first method approximated the bulk flow through each vane passage using a single rake measurement positioned near the center of the passage. All vane passages were measured virtually by rotating the distortion upstream by an increment equal to one vane passage. This method proved successful in tracking the distortion propagation and attenuation from the AIP up until the compressor exit. A second, more detailed, inter-stage flow field characterization method was used that generated a total pressure field with a circumferential resolution of 880 increments, or one every 0.41°. The resulting fields demonstrated the importance of secondary flows in the propagation of a total pressure distortion at the different loading conditions investigated. A second objective of this research was to document proposals and design efforts to outfit the existing P3S research compressor with a strain gage telemetry system. The purpose of this system is to validate and supplement existing blade tip timing data on the embedded rotor stage to support the development and validation of novel aeromechanical analysis tools. Integration strategies and telemetry considerations are discussed based on proposals and consultation provided by suppliers.

A Concept for the One Degree Imager (ODI) Data Reduction Pipeline and Archiving System

NASA Astrophysics Data System (ADS)

Knezek, Patricia; Stobie, B.; Michael, S.; Valdes, F.; Marru, S.; Henschel, R.; Pierce, M.

2010-05-01

The One Degree Imager (ODI), currently being built by the WIYN Observatory, will provide tremendous possibilities for conducting diverse scientific programs. ODI will be a complex instrument, using non-conventional Orthogonal Transfer Array (OTA) detectors. Due to its large field of view, small pixel size, use of OTA technology, and expected frequent use, ODI will produce vast amounts of astronomical data. If ODI is to achieve its full potential, a data reduction pipeline must be developed. Long-term archiving must also be incorporated into the pipeline system to ensure the continued value of ODI data. This paper presents a concept for an ODI data reduction pipeline and archiving system. To limit costs and development time, our plan leverages existing software and hardware, including existing pipeline software, Science Gateways, Computational Grid & Cloud Technology, Indiana University's Data Capacitor and Massive Data Storage System, and TeraGrid compute resources. Existing pipeline software will be augmented to add functionality required to meet challenges specific to ODI, enhance end-user control, and enable the execution of the pipeline on grid resources including national grid resources such as the TeraGrid and Open Science Grid. The planned system offers consistent standard reductions and end-user flexibility when working with images beyond the initial instrument signature removal. It also gives end-users access to computational and storage resources far beyond what are typically available at most institutions. Overall, the proposed system provides a wide array of software tools and the necessary hardware resources to use them effectively.

Pipeline corridors through wetlands -- Impacts on plant communities: Norris Brook Crossing Peabody, Massachusetts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shem, L.M.; Van Dyke, G.D.; Zimmerman, R.E.

1994-12-01

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipelines on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and right-of-way (ROW) management practices. This report presents the results of a survey conducted August 17--19, 1992, at the Norris Brook crossing in the town of Peabody, Essex County, Massachusetts. The pipeline at this site was installed during September and October 1990. A backhoe was used to install the pipeline. The pipe was assembledmore » on the adjacent upland and slid into the trench, after which the backhoe was used again to fill the trench and cover the pipeline. Within two years after pipeline construction, a dense vegetative community, composed predominantly of native perennial species, had become established on the ROW. Compared with adjacent natural areas undisturbed by pipeline installation, there was an increase in purple loosestrife and cattail within the ROW, while large woody species were excluded from the ROW. As a result of the ROW`s presence, habitat diversity, edge-type habitat, and species diversity increased within the site. Crooked-stem aster, Aster prenanthoides (a species on the Massasschusetts list of plants of special concern), occurred in low numbers in the adjacent natural areas and had reinvaded the ROW in low numbers.« less

Wall boundary layer development near the tip region of an IGV of an axial flow compressor

NASA Technical Reports Server (NTRS)

Lakshminarayana, B.; Sitaram, N.

1983-01-01

The annulus wall boundary layer inside the blade passage of the inlet guide vane (IGV) passage of a low-speed axial compressor stage was measured with a miniature five-hole probe. The three-dimensional velocity and pressure fields were measured at various axial and tangential locations. Limiting streamline angles and static pressures were also measured on the casing of the IGV passage. Strong secondary vorticity was developed. The data were analyzed and correlated with the existing velocity profile correlations. The end wall losses were also derived from these data.

Near-blade flow structure modification

NASA Astrophysics Data System (ADS)

Kura, T.; Fornalik-Wajs, E.

2016-10-01

In this paper, the importance of near-blade flow structure influence on the performance of a centrifugal compressor was discussed. The negative effects of eddies and secondary flows appearance were described, together with the proposal of their reduction. Three-dimensional analyses were performed for the rotors. Focus was placed on the blade's 3D curvature impact on the efficiency of compression, and the influence of blade-shroud tip existence. A few design proposals were investigated - their performance maps were the basis of further analysis. Proposed modification of blade shape changed the near-blade flow structure and improved the compressor performance.

Optimization of Error-Bounded Lossy Compression for Hard-to-Compress HPC Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Di, Sheng; Cappello, Franck

Since today’s scientific applications are producing vast amounts of data, compressing them before storage/transmission is critical. Results of existing compressors show two types of HPC data sets: highly compressible and hard to compress. In this work, we carefully design and optimize the error-bounded lossy compression for hard-tocompress scientific data. We propose an optimized algorithm that can adaptively partition the HPC data into best-fit consecutive segments each having mutually close data values, such that the compression condition can be optimized. Another significant contribution is the optimization of shifting offset such that the XOR-leading-zero length between two consecutive unpredictable data points canmore » be maximized. We finally devise an adaptive method to select the best-fit compressor at runtime for maximizing the compression factor. We evaluate our solution using 13 benchmarks based on real-world scientific problems, and we compare it with 9 other state-of-the-art compressors. Experiments show that our compressor can always guarantee the compression errors within the user-specified error bounds. Most importantly, our optimization can improve the compression factor effectively, by up to 49% for hard-tocompress data sets with similar compression/decompression time cost.« less

77 FR 73649 - Dominion Transmission Inc.; Notice of Availability of the Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-11

...-inch-diameter pipeline (TL-610-Extension 1), associated with a new valve at DTI's existing Elk Run Gate...-inch-diameter pipeline (TL-614) in Potter County, Pennsylvania; Installation of about 900 feet of new 24-inch-diameter pipeline (TL-615) and a new meter station in Greene County, Pennsylvania; Upgrades...

77 FR 26353 - Notice of Availability of the Environmental Assessment and Request for Comments on Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-03

... a liquid form at an existing natural gas facility in North Dakota. The ethane that would be... maintenance of pipeline facilities of natural gas liquids and also evaluates reasonable alternatives to the... Pipeline Project would be an underground high vapor pressure pipeline that would carry liquid ethane from...

77 FR 68115 - Millennium Pipeline Company, L.L.C.; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

...] Millennium Pipeline Company, L.L.C.; Notice of Application Take notice that on November 1, 2012, Millennium Pipeline Company, L.L.C. (Millennium), One Blue Hill Plaza, Seventh Floor, P.O. Box 1565, Pearl River, New... system to the existing interconnection with Algonquin Gas Transmission, L.L.C. in Ramapo, New York and...

78 FR 67358 - Columbia Gas Transmission, LLC; Notice of Availability of the Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-12

.... Columbia would also construct miscellaneous aboveground equipment including the installation of a pig launcher,\\2\\ pig receiver, mainline valve, and a gas heater. \\1\\ A pipeline loop is a segment of pipe constructed parallel to an existing pipeline to increase capacity. \\2\\ A ``pig'' is a tool that the pipeline...

U. S. National Transportation Safety Board (NTSB) reports, recommendations, and responses availability. [Evaluation of fillet-welded reinforcement sleeves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-10-09

Following the ignition of crude oil that leaked from a fractured 22 in. oil pipeline at a levee crossing at Berwick, Louisiana, on 1/2/80, NTSB has recommended that Texaco Pipeline Co., the line owner, review the practice of using fillet-welded reinforcement sleeves for tie-in welds to determine if these sleeves have caused any pipeline failures in its system; notify the pipeline patrol of the location of such existing sleeves and instruct it to examine the areas around these sleeves for signs of leakage; and evaluate existing procdures for leak detection to make these procedures more effective. The American Petroleum Institutemore » has also been urged to notify its member companies of the Berwick accident and the aforementioned recommendations. These pipeline and other safety recommendation letters and reports of accidents, including the determination of the cause of the explosion, burning, and sinking of the Liberian tanker Seatige.« less

CoGI: Towards Compressing Genomes as an Image.

PubMed

Xie, Xiaojing; Zhou, Shuigeng; Guan, Jihong

2015-01-01

Genomic science is now facing an explosive increase of data thanks to the fast development of sequencing technology. This situation poses serious challenges to genomic data storage and transferring. It is desirable to compress data to reduce storage and transferring cost, and thus to boost data distribution and utilization efficiency. Up to now, a number of algorithms / tools have been developed for compressing genomic sequences. Unlike the existing algorithms, most of which treat genomes as one-dimensional text strings and compress them based on dictionaries or probability models, this paper proposes a novel approach called CoGI (the abbreviation of Compressing Genomes as an Image) for genome compression, which transforms the genomic sequences to a two-dimensional binary image (or bitmap), then applies a rectangular partition coding algorithm to compress the binary image. CoGI can be used as either a reference-based compressor or a reference-free compressor. For the former, we develop two entropy-based algorithms to select a proper reference genome. Performance evaluation is conducted on various genomes. Experimental results show that the reference-based CoGI significantly outperforms two state-of-the-art reference-based genome compressors GReEn and RLZ-opt in both compression ratio and compression efficiency. It also achieves comparable compression ratio but two orders of magnitude higher compression efficiency in comparison with XM--one state-of-the-art reference-free genome compressor. Furthermore, our approach performs much better than Gzip--a general-purpose and widely-used compressor, in both compression speed and compression ratio. So, CoGI can serve as an effective and practical genome compressor. The source code and other related documents of CoGI are available at: http://admis.fudan.edu.cn/projects/cogi.htm.

77 FR 33213 - Transcontinental Gas Pipe Line Company, LLC; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... certificate issued in Docket No. CP82-426, for authorization to replace two existing Ansaldo electric motors with two new electric motors at Transco's existing Compressor Station 205 in Princeton, New Jersey... motors and associated variable frequency drives for units 1 and 2 with two new Siemens electric motors...

30 CFR 250.1003 - Installation, testing, and repair requirements for DOI pipelines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... installed in water depths of less than 200 feet shall be buried to a depth of at least 3 feet unless they... damage potential exists. (b)(1) Pipelines shall be pressure tested with water at a stabilized pressure of... repair, the pipeline shall be pressure tested with water or processed natural gas at a minimum stabilized...

76 FR 10348 - Northwest Pipeline, GP; Notice of Intent To Prepare an Environmental Assessment for the Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-24

... approximately 15 miles of 16-inch- diameter pipeline; Relocate an existing pig \\1\\ receiver from MP 41.02 to MP 48.04 and remove aboveground facilities, including a pig launcher, piping, and valves, to accommodate... ``pig'' is a tool that is inserted into and moves through the pipeline, and is used for cleaning the...

Methodology for the assessment of oxygen as an energy carrier

NASA Astrophysics Data System (ADS)

Yang, Ming Wei

Due to the energy intensity of the oxygen generating process, the electric power grid would benefit if the oxygen generating process was consumed electric power only during low demand periods. Thus, the question to be addressed in this study is whether oxygen production and/or usage can be modified to achieve energy storage and/or transmission objectives at lower cost. The specific benefit to grid would be a leveling, over time, of the demand profile and thus would require less installation capacity. In order to track the availability of electricity, a compressed air storage unit is installed between the cryogenic distillation section and the main air compressor of air separation unit. A profit maximizing scheme for sizing storage inventory and related equipments is developed. The optimum scheme is capable of market responsiveness. Profits of steel maker, oxy-combustion, and IGCC plants with storage facilities can be higher than those plants without storage facilities, especially, at high-price market. Price tracking feature of air storage integration will certainly increase profit margins of the plants. The integration may push oxy-combustion and integrated gasification combined cycle process into economic viability. Since oxygen is used in consumer sites, it may generate at remote locations and transport to the place needed. Energy losses and costs analysis of oxygen transportation is conducted for various applications. Energy consumptions of large capacity and long distance GOX and LOX pipelines are lower than small capacity pipelines. However, transportation losses and costs of GOX and LOX pipelines are still higher than electricity transmission.

Development of Protective Coatings for Co-Sequestration Processes and Pipelines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bierwagen, Gordon; Huang, Yaping

2011-11-30

The program, entitled Development of Protective Coatings for Co-Sequestration Processes and Pipelines, examined the sensitivity of existing coating systems to supercritical carbon dioxide (SCCO2) exposure and developed new coating system to protect pipelines from their corrosion under SCCO2 exposure. A literature review was also conducted regarding pipeline corrosion sensors to monitor pipes used in handling co-sequestration fluids. Research was to ensure safety and reliability for a pipeline involving transport of SCCO2 from the power plant to the sequestration site to mitigate the greenhouse gas effect. Results showed that one commercial coating and one designed formulation can both be supplied asmore » potential candidates for internal pipeline coating to transport SCCO2.« less

Miniature Pulse Tube Cooler

NASA Astrophysics Data System (ADS)

Tward, E.; Nguyen, T.; Godden, J.; Toma, G.

2004-06-01

A high capacity miniature pulse tube cooler for space that is scaled from the High Efficiency Cryocooler (HEC) is being developed. The low mass (1.5 kg) integral pulse tube cryocooler can provide large cooling power over a wide temperature range (e.g., 5 W at 95 K). The cooler is designed to be compatible with the existing HEC flight electronics. A small back-to-back flexure compressor drives a pulse tube cold head which is integrated with the compressor. The cooler has been tested with both linear and coaxial cold heads. A description of the cooler and its performance in both linear and coaxial cold head versions is presented.

Single shaft automotive gas turbine engine characterization test

NASA Technical Reports Server (NTRS)

Johnson, R. A.

1979-01-01

An automotive gas turbine incorporating a single stage centrifugal compressor and a single stage radial inflow turbine is described. Among the engine's features is the use of wide range variable geometry at the inlet guide vanes, the compressor diffuser vanes, and the turbine inlet vanes to achieve improved part load fuel economy. The engine was tested to determine its performance in both the variable geometry and equivalent fixed geometry modes. Testing was conducted without the originally designed recuperator. Test results were compared with the predicted performance of the nonrecuperative engine based on existing component rig test maps. Agreement between test results and the computer model was achieved.

Boosting devices with integral features for recirculating exhaust gas

DOEpatents

Wu, Ko -Jen

2015-09-15

According to one embodiment of the invention, a compressor housing includes a compressor inlet in fluid communication with a compressor volute configured to house a compressor wheel, the compressor inlet configured to provide a first air flow to the compressor wheel and a compressor outlet in fluid communication with the compressor volute, the compressor outlet configured to direct a compressed gas to an intake manifold. The compressor housing further includes an exhaust gas recirculation inlet port in fluid communication with the compressor volute, the exhaust gas recirculation inlet port being configured to combine an exhaust gas flow with the air flow to the compressor wheel.

PipelineDog: a simple and flexible graphic pipeline construction and maintenance tool.

PubMed

Zhou, Anbo; Zhang, Yeting; Sun, Yazhou; Xing, Jinchuan

2018-05-01

Analysis pipelines are an essential part of bioinformatics research, and ad hoc pipelines are frequently created by researchers for prototyping and proof-of-concept purposes. However, most existing pipeline management system or workflow engines are too complex for rapid prototyping or learning the pipeline concept. A lightweight, user-friendly and flexible solution is thus desirable. In this study, we developed a new pipeline construction and maintenance tool, PipelineDog. This is a web-based integrated development environment with a modern web graphical user interface. It offers cross-platform compatibility, project management capabilities, code formatting and error checking functions and an online repository. It uses an easy-to-read/write script system that encourages code reuse. With the online repository, it also encourages sharing of pipelines, which enhances analysis reproducibility and accountability. For most users, PipelineDog requires no software installation. Overall, this web application provides a way to rapidly create and easily manage pipelines. PipelineDog web app is freely available at http://web.pipeline.dog. The command line version is available at http://www.npmjs.com/package/pipelinedog and online repository at http://repo.pipeline.dog. ysun@kean.edu or xing@biology.rutgers.edu or ysun@diagnoa.com. Supplementary data are available at Bioinformatics online.

Pipeline corridors through wetlands - impacts on plant communities: Deep Creek and Brandy Branch crossings, Nassau County, Florida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shem, L.M.; Van Dyke, G.D.; Zimmerman, R.E.

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipelines on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and right-of-way (ROW) management practices. This report presents the results of surveys conducted July 14-18, 1992, at the Deep Creek and the Brandy Branch crossings of a pipeline installed during May 1991 in Nassau County, Florida. Both floodplains supported bottomland hardwood forests. The pipeline at the Deep Creek crossing was installed by means ofmore » horizontal directional drilling after the ROW had been clear-cut, while the pipeline at the Brandy Branch crossing was installed by means of conventional open trenching. Neither site was seeded or fertilized. At the time of sampling, a dense vegetative community, made up primarily of native perennial herbaceous species, occupied the ROW within the Deep Creek floodplain. The Brandy Branch ROW was vegetated by a less dense stand of primarily native perennial herbaceous plants. Plant diversity was also lower at the Brandy Branch crossing than at the Deep Creek crossing. The results suggest that some of the differences in plant communities are related to the more hydric conditions at the Brandy Branch floodplain.« less

Review on stress corrosion and corrosion fatigue failure of centrifugal compressor impeller

NASA Astrophysics Data System (ADS)

Sun, Jiao; Chen, Songying; Qu, Yanpeng; Li, Jianfeng

2015-03-01

Corrosion failure, especially stress corrosion cracking and corrosion fatigue, is the main cause of centrifugal compressor impeller failure. And it is concealed and destructive. This paper summarizes the main theories of stress corrosion cracking and corrosion fatigue and its latest developments, and it also points out that existing stress corrosion cracking theories can be reduced to the anodic dissolution (AD), the hydrogen-induced cracking (HIC), and the combined AD and HIC mechanisms. The corrosion behavior and the mechanism of corrosion fatigue in the crack propagation stage are similar to stress corrosion cracking. The effects of stress ratio, loading frequency, and corrosive medium on the corrosion fatigue crack propagation rate are analyzed and summarized. The corrosion behavior and the mechanism of stress corrosion cracking and corrosion fatigue in corrosive environments, which contain sulfide, chlorides, and carbonate, are analyzed. The working environments of the centrifugal compressor impeller show the behavior and the mechanism of stress corrosion cracking and corrosion fatigue in different corrosive environments. The current research methods for centrifugal compressor impeller corrosion failure are analyzed. Physical analysis, numerical simulation, and the fluid-structure interaction method play an increasingly important role in the research on impeller deformation and stress distribution caused by the joint action of aerodynamic load and centrifugal load.

Effect of Ethanol Chemistry on SCC of Carbon Steel

DOT National Transportation Integrated Search

2011-02-22

Pipeline companies have a keen interest in assessing the feasibility of transporting fuel grade ethanol (FGE) and ethanol blends in existing pipelines. Previous field experience and laboratory research, funded by PRCI and API, has shown that steel ca...

A 400,000 lb crude oil storage tank was moved on an 11 in. air blanket

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-03-01

The British patented-system used to move the 55,000 bbl tank at the Cushing, Okla., tank farm of Getty Oil Co. uses the same airlift principle employed by various hovercraft. Representatives from 20 pipeline and oil companies watched the move, which placed the tank 22 ft higher and 600 ft away from its former location, to improve its gravity flow rate, an improvement spurred by greater crude demands placed on Cushing Terminal. Two 425 hp air compressors were attached to the tank's shell and produced 130,000 cu ft/min of air. The airflow was directed beneath the tank through a segmented skirtmore » fixed to the circumference of the tank's base. Less than 0.5 psi air pressure across the tank floor was needed to lift the tank. Four large D-7 tractors pulled and guided the tank up the incline onto its new pad, where the vessel was rotated into alignment for piping connections. Preliminary rig-up, grading, and pad preparation took six days, but actual tank relocation required only two hours. Getty's Cushing terminal feeds to the 20 in. dia Osage pipeline that serves Getty's El Dorado, Kans., refinery as well as other carriers.« less

Coordinated Scheduling for Interdependent Electric Power and Natural Gas Infrastructures

DOE PAGES

Zlotnik, Anatoly; Roald, Line; Backhaus, Scott; ...

2016-03-24

The extensive installation of gas-fired power plants in many parts of the world has led electric systems to depend heavily on reliable gas supplies. The use of gas-fired generators for peak load and reserve provision causes high intraday variability in withdrawals from high-pressure gas transmission systems. Such variability can lead to gas price fluctuations and supply disruptions that affect electric generator dispatch, electricity prices, and threaten the security of power systems and gas pipelines. These infrastructures function on vastly different spatio-temporal scales, which prevents current practices for separate operations and market clearing from being coordinated. Here in this article, wemore » apply new techniques for control of dynamic gas flows on pipeline networks to examine day-ahead scheduling of electric generator dispatch and gas compressor operation for different levels of integration, spanning from separate forecasting, and simulation to combined optimal control. We formulate multiple coordination scenarios and develop tractable physically accurate computational implementations. These scenarios are compared using an integrated model of test networks for power and gas systems with 24 nodes and 24 pipes, respectively, which are coupled through gas-fired generators. The analysis quantifies the economic efficiency and security benefits of gas-electric coordination and dynamic gas system operation.« less

California crude-pipeline plans detailed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronco, M.J.

1986-06-09

California and the U.S. West have recently become a center for crude-oil pipeline activity. That activity includes existing and proposed lines, offshore and onshore terminals, and some unusual permitting and construction requirements. Operation of existing pipelines is influenced by the varying gravities of crudes in the area. California has three distinct producing areas from which pipelines deliver crude to refineries or marines terminals: 1. The inland Los Angeles basin and coast from Orange County to Ventura County. 2. The San Joaquin Valley in central California which is between the coastal mountains and the Sierras. 3. That portion of the Outermore » Continental Shelf (OCS) located primarily in federal waters off Santa Barbara and San Luis Obispo counties on the central coast. The Los Angeles coastal and inland basin crude-oil pipeline system consists of gathering lines to move crude from the many wells throughout Ventura, Orange, and Los Angeles counties to operating refineries in the greater Los Angeles area. Major refineries include ARCO at Carson, Chevron at El Segundo, Mobil at Torrance, and Shell, Texaco, and Unical at Wilmington. The many different crude-oil pipelines serving these refineries from Ventura County and Orange County and from the many sites around Los Angeles County are too numerous to list.« less

Low Base-Substitution Mutation Rate in the Germline Genome of the Ciliate Tetrahymena thermophila

DTIC Science & Technology

2016-09-15

generations of mutation accumulation (MA). We applied an existing mutation-calling pipeline and developed a new probabilistic mutation detection approach...noise introduced by mismapped reads. We used both our new method and an existing mutation-calling pipeline (Sung, Tucker, et al. 2012) to analyse the...and larger MA experiments will be required to confidently estimate the mutational spectrum of a species with such a low mutation rate. Materials and

A case of industrial safety appraisal for extension of service life of GTK-10-4 gas turbines used at gas transmission stations

NASA Astrophysics Data System (ADS)

Rybnikov, A. I.; Kovalev, A. G.; Kryukov, I. I.; Leont'ev, S. A.; Moshnikov, A. V.

2017-04-01

It is shown that the extended life and enhanced operational reliability of parts and subassemblies of the most popular GTK-10-4 gas transmission plants are determined by the enhanced efficiency of the control over technical condition and operational safety of turbine plants in conformity with industrial safety requirements imposed on gas pipeline compressor stations. It has been established that the materials of parts and subassemblies of gas turbine plants with different, especially with maximal operating time, shall be exposed to NDT for the purpose of determining the actual mechanical characteristics of these materials with different operating time and calculating residual life. The analysis of damageability and operating conditions has helped to identify parts and subassemblies for repair or replacement with the highest frequency of unacceptable defects. These parts and subassemblies have been shown to include base members of the axial compressor (AC), a turbine housing, an axial compressor rotor, high- and low-pressure turbine (HPT and LPT) discs, a 12-part holder, the housing of the holder of HPT and LPT guiding blades, a sealed baffler, and working and guiding AC, LPT and HPT blades. The most typical operational defects have been enumerated and analyzed. It has been determined that the primary task of the industrial safety appraisal for extending the life of GTK-10-4 with limit-exceeding operating time is to thoroughly examine HPT and LPT discs with more than 130,000 hours of operating time and establish by DT methods characteristics of materials for evaluation, taking account of their degradation, and residual life of critical turbine elements. In addition, it has been shown that the service life of HP turbine discs can be extended by replacing the disc material (EP-428 12% chromium steel) with a material with a higher linear expansion factor that somewhat exceeds the expansion factor of EI-893 nickel alloy used to melt out working blades.

Landslide and Land Subsidence Hazards to Pipelines

USGS Publications Warehouse

Baum, Rex L.; Galloway, Devin L.; Harp, Edwin L.

2008-01-01

Landslides and land subsidence pose serious hazards to pipelines throughout the world. Many existing pipeline corridors and more and more new pipelines cross terrain that is affected by either landslides, land subsidence, or both. Consequently the pipeline industry recognizes a need for increased awareness of methods for identifying and evaluating landslide and subsidence hazard for pipeline corridors. This report was prepared in cooperation with the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration, and Pipeline Research Council International through a cooperative research and development agreement (CRADA) with DGH Consulting, Inc., to address the need for up-to-date information about current methods to identify and assess these hazards. Chapters in this report (1) describe methods for evaluating landslide hazard on a regional basis, (2) describe the various types of land subsidence hazard in the United States and available methods for identifying and quantifying subsidence, and (3) summarize current methods for investigating individual landslides. In addition to the descriptions, this report provides information about the relative costs, limitations and reliability of various methods.

A hybrid method of estimating pulsating flow parameters in the space-time domain

NASA Astrophysics Data System (ADS)

Pałczyński, Tomasz

2017-05-01

This paper presents a method for estimating pulsating flow parameters in partially open pipes, such as pipelines, internal combustion engine inlets, exhaust pipes and piston compressors. The procedure is based on the method of characteristics, and employs a combination of measurements and simulations. An experimental test rig is described, which enables pressure, temperature and mass flow rate to be measured within a defined cross section. The second part of the paper discusses the main assumptions of a simulation algorithm elaborated in the Matlab/Simulink environment. The simulation results are shown as 3D plots in the space-time domain, and compared with proposed models of phenomena relating to wave propagation, boundary conditions, acoustics and fluid mechanics. The simulation results are finally compared with acoustic phenomena, with an emphasis on the identification of resonant frequencies.

Supplement B to compilation of air pollutant emission factors, volume 1. Stationary point and area sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This document contains emission factors and process information for more than 200 air pollution source categories. This Supplement to AP-42 addresses pollutant-generating activity from Bituminous And Subbituminous Coal Combustion, Anthracite Coal Combustion, Fuel Oil Combustion, Natural Gas Combustion, Liquefied Petroleum Gas Combustion, Wood Waste Combustion In Boilers, Lignite Combustion, Bagasse Combustion In Sugar Mills, Residential Fireplaces, Residential Wood Stoves, Waste Oil Combustion, Stationary Gas Turbines For Electricity Generation, Heavy-duty Natural Gas-fired Pipeline Compressor Engines And Turbines, Gasoline and Diesel Industrial Engines, Large Stationary Diesel And All Stationary Dual-fuel Engines, Adipic Acid, Cotton Ginning, Alfafalfa Dehydrating, Malt Beverages, Ceramic Products Manufacturing,more » Electroplating, Wildfires And Prescribed Burning, Emissions From Soils-Greenhouse Gases, Termites-Greenhouse Gases, and Lightning Emissions-Greenhouse Gases.« less

Supplement a to compilation of air pollutant emission factors. Volume 1. Stationary point and area sources. Fifth edition

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-02-01

This Supplement to AP-42 addresses pollutant-generating activity from Bituminous and Subbituminous Coal Combustion; Anthracite Coal Combustion; Fuel Oil Combustion; Natural Gas Combustion; Wood Waste Combustion in Boilers; Lignite Combustion; Waste Oil Combustion: Stationary Gas Turbines for Electricity Generation; Heavy-duty Natural Gas-fired Pipeline Compressor Engines; Large Stationary Diesel and all Stationary Dual-fuel engines; Natural Gas Processing; Organic Liquid Storage Tanks; Meat Smokehouses; Meat Rendering Plants; Canned Fruits and Vegetables; Dehydrated Fruits and Vegetables; Pickles, Sauces and Salad Dressing; Grain Elevators and Processes; Cereal Breakfast Foods; Pasta Manufacturing; Vegetable Oil Processing; Wines and Brandy; Coffee Roasting; Charcoal; Coal Cleaning; Frit Manufacturing; Sandmore » and Gravel Processing; Diatomite Processing; Talc Processing; Vermiculite Processing; paved Roads; and Unpaved Roads. Also included is information on Generalized Particle Size Distributions.« less

Pipeline corridors through wetlands - impacts on plant communities: Cassadaga Creek Tributary Crossing, Gerry Township, Chautauqua County, New York. Topical report, August 1992--November 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shem, L.M.; Van Dyke, G.D.; Zimmerman, R.E.

1994-12-01

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipelines on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and right-of-way (ROW) management practices. This report presents the results of a survey conducted over the period of August 3-4, 1992, at the Cassadaga wetlands crossing in Gerry Township, Chautauqua County, New York. The pipeline at this site was installed during February and March 1981. After completion of pipeline installation, the ROW was fertilized,more » mulched, and seeded with annual ryegrass. Two adjacent sites were surveyed in this study: a forested wetland and an emergent wetlands Eleven years after pipeline installation, the ROW at both sites supported diverse vegetative communities. Although devoid of large woody species, the ROW within the forested wetland had a dense vegetative cover. The ROW within the emergent wetland had a slightly less dense and more diverse vegetative community compared with that in the adjacent natural areas (NAs). The ROW within the emergent wetland also had a large number of introduced species that were not present in the adjacent NAs. The ROW, with its emergent marsh plant community, provided habitat diversity within the forested wetlands Because the ROW contained species not found within the adjacent NAs, overall species diversity was increased.« less

Guidelines for Constructing Natural Gas and Liquid Hydrocarbon Pipelines Through Areas Prone to Landslide and Subsidence Hazards

DOT National Transportation Integrated Search

2009-01-01

These guidelines provide recommendations for the assessment of new and existing natural gas and liquid hydrocarbon pipelines subjected to potential ground displacements resulting from landslides and subsidence. The process of defining landslide and s...

High ratio recirculating gas compressor

DOEpatents

Weinbrecht, J.F.

1989-08-22

A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.

Corrosivity Sensor for Exposed Pipelines Based on Wireless Energy Transfer.

PubMed

Lawand, Lydia; Shiryayev, Oleg; Al Handawi, Khalil; Vahdati, Nader; Rostron, Paul

2017-05-30

External corrosion was identified as one of the main causes of pipeline failures worldwide. A solution that addresses the issue of detecting and quantifying corrosivity of environment for application to existing exposed pipelines has been developed. It consists of a sensing array made of an assembly of thin strips of pipeline steel and a circuit that provides a visual sensor reading to the operator. The proposed sensor is passive and does not require a constant power supply. Circuit design was validated through simulations and lab experiments. Accelerated corrosion experiment was conducted to confirm the feasibility of the proposed corrosivity sensor design.

Compact Graphical Representation of Phylogenetic Data and Metadata with GraPh1An

DTIC Science & Technology

2016-09-12

pipelines . This allows for a higher degree of analysis reproducibility, but the software must correspondingly be available for local installation and callable...these operations are available in the GraPhlAn software repository). Reproducible integration with existing analysis tools and pipelines Graphical...from different analysis pipelines , generating the necessary input files for GraPhlAn. Export2graphlan directly supports MetaPhlAn2, LEfSe, and HUMAnN

A design study of a reaction control system for a V/STOL fighter/attack aircraft

NASA Technical Reports Server (NTRS)

Beard, B. B.; Foley, W. H.

1983-01-01

Attention is given to a short takeoff vertical landing (STOVL) aircraft reaction control system (RCS) design study. The STOVL fighter/attack aircraft employs an existing turbofan engine, and its hover requirement places a premium on weight reduction, which eliminates prospective nonairbreathing RCSs. A simple engine compressor bleed RCS degrades overall performance to an unacceptable degree, and the supersonic requirement precludes the large volume alternatives of thermal or ejector thrust augmentation systems as well as the ducting of engine exhaust gases and the use of a dedicated turbojet. The only system which addressed performance criteria without requiring major engine modifications was a dedicated load compressor driven by an auxilliary power unit.

Accounting for the Confound of Meninges in Segmenting Entorhinal and Perirhinal Cortices in T1-Weighted MRI.

PubMed

Xie, Long; Wisse, Laura E M; Das, Sandhitsu R; Wang, Hongzhi; Wolk, David A; Manjón, Jose V; Yushkevich, Paul A

2016-10-01

Quantification of medial temporal lobe (MTL) cortices, including entorhinal cortex (ERC) and perirhinal cortex (PRC), from in vivo MRI is desirable for studying the human memory system as well as in early diagnosis and monitoring of Alzheimer's disease. However, ERC and PRC are commonly over-segmented in T1-weighted (T1w) MRI because of the adjacent meninges that have similar intensity to gray matter in T1 contrast. This introduces errors in the quantification and could potentially confound imaging studies of ERC/PRC. In this paper, we propose to segment MTL cortices along with the adjacent meninges in T1w MRI using an established multi-atlas segmentation framework together with super-resolution technique. Experimental results comparing the proposed pipeline with existing pipelines support the notion that a large portion of meninges is segmented as gray matter by existing algorithms but not by our algorithm. Cross-validation experiments demonstrate promising segmentation accuracy. Further, agreement between the volume and thickness measures from the proposed pipeline and those from the manual segmentations increase dramatically as a result of accounting for the confound of meninges. Evaluated in the context of group discrimination between patients with amnestic mild cognitive impairment and normal controls, the proposed pipeline generates more biologically plausible results and improves the statistical power in discriminating groups in absolute terms comparing to other techniques using T1w MRI. Although the performance of the proposed pipeline is inferior to that using T2-weighted MRI, which is optimized to image MTL sub-structures, the proposed pipeline could still provide important utilities in analyzing many existing large datasets that only have T1w MRI available.

Incorporation of Electrical Systems Models Into an Existing Thermodynamic Cycle Code

NASA Technical Reports Server (NTRS)

Freeh, Josh

2003-01-01

Integration of entire system includes: Fuel cells, motors, propulsors, thermal/power management, compressors, etc. Use of existing, pre-developed NPSS capabilities includes: 1) Optimization tools; 2) Gas turbine models for hybrid systems; 3) Increased interplay between subsystems; 4) Off-design modeling capabilities; 5) Altitude effects; and 6) Existing transient modeling architecture. Other factors inclde: 1) Easier transfer between users and groups of users; 2) General aerospace industry acceptance and familiarity; and 3) Flexible analysis tool that can also be used for ground power applications.

Gas from Mexico: the brightest prospect for interim relief for U. S. consumers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Falck, E.

1977-08-04

The U. S. natural gas industry is experiencing its greatest shortage and prices are continuing to advance to new highs. The regulated price for ''new'' gas has increased from 50 cents to $1.42 per Mcf plus escalations, and the Carter energy plan would increase this price further to $1.75 per Mcf. However, assuming the most optimistic results from conservation and new discoveries of gas, there remains an urgent need for additional sources of supply. The new government of Mexico is showing great interest in developing its natural gas and oil resources and also showing a new cordial atmosphere towards themore » U. S. This new atmosphere opens up the possibility for the U. S. to provide finance-capital, steel, compressors, and drilling equipment in exchange for Mexican natural gas. The transportation facilities for natural gas from Mexico will be less costly than from Alaska's North Slope. Equally important, gas can be brought in from Mexico at a much earlier date than from the North Slope. Pemex (Petroleos Mexicanos) has announced plans to construct a 780-mile, 48-inch pipeline to transport natural gas from the Reforma sweetening plant at Cardenas, Chiapas, to Reynosa where it can connect with U. S. pipelines at McAllen, Texas. Shipments of gas could begin within two or three years if satisfactory gas purchase contracts, financing, and government approval can be completed promptly. This pipeline is estimatedto cost in the neighborhood of $1 billion and could be completed by 1979. Methods of delivering natural gas to the U. S. from the North Slope, Mexican oil and gas reserves, and the economics of the Pemex gasoline and possible U. S. financing are discussed. (MCW)« less

49 CFR 190.239 - Safety orders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... pipeline integrity risk to public safety, property, or the environment, the Associate Administrator may... existence of a condition that poses a pipeline integrity risk to public safety, property, or the environment... public safety, property, or the environment. (5) Post-hearing action. Following a hearing under this...

A computational analysis of the aerodynamic and aeromechanical behavior of the purdue multistage compressor

NASA Astrophysics Data System (ADS)

Monk, David James Winchester

Compressor design programs are becoming more reliant on computational tools to predict and optimize aerodynamic and aeromechanical behavior within a compressor. Recent trends in compressor development continue to push for more efficient, lighter weight, and higher performance machines. To meet these demands, designers must better understand the complex nature of the inherently unsteady flow physics inside of a compressor. As physical testing can be costly and time prohibitive, CFD and other computational tools have become the workhorse during design programs. The objectives of this research were to investigate the aerodynamic and aeromechanical behavior of the Purdue multistage compressor, as well as analyze novel concepts for reducing rotor resonant responses in compressors. Advanced computational tools were utilized to allow an in-depth analysis of the flow physics and structural characteristics of the Purdue compressor, and complement to existing experimental datasets. To analyze the aerodynamic behavior of the compressor a Rolls-Royce CFD code, developed specifically for multistage turbomachinery flows, was utilized. Steady-state computations were performed using the RANS solver on a single-passage mesh. Facility specific boundary conditions were applied to the model, increasing the model fidelity and overall accuracy of the predictions. Detailed investigations into the overall compressor performance, stage performance, and individual blade row performance were completed. Additionally, separation patterns on stator vanes at different loading conditions were investigated by plotting pathlines near the stator suction surfaces. Stator cavity leakage flows were determined to influence the size and extent of stator hub separations. In addition to the aerodynamic analysis, a Rolls-Royce aeroelastic CFD solver was utilized to predict the forced response behavior of Rotor 2, operating at the 1T mode crossing of the Campbell Diagram. This computational tool couples aerodynamic predictions with structural models to determine maximum Rotor 2 vibration amplitudes excited by both vortical and potential disturbances. A multi-bladerow, full-annulus unsteady simulation was performed to capture the aerodynamic forcing functions and understand the influence of bladerow interactions on these flow disturbances. The strength and frequency content of the S1 vortical field and S2 potential field were examined to quantify the aerodynamic forces exciting resonant vibrations. Detailed comparisons were made to experimental datasets acquired on the Purdue compressor which characterize the forced response behavior at the 1T mode crossing. Lastly, stator asymmetry was examined as a means of reducing forced response vibration amplitudes. For this study, a new Stator 1 ring was designed with a reduced vane count, creating the ability to isolate the relative contribution of the S1 wakes on R2 vibrational amplitudes. A second Stator 1 ring was then designed with asymmetric vane spacing such that two stator half-sectors of different vane counts were joined together to form a full stator ring. By joining two stator half-sectors with different vane counts, the energy of the wakes is spread into additional frequencies, thereby reducing the overall amplitudes. The aeroelastic CFD solver was again used to perform steady-state and unsteady simulations, capturing the effect of the stator asymmetry on resonant vibrational amplitudes. The resulting blade deflection amplitudes are presented and discussed in detail.

Integrated Heat Exchange For Recuperation In Gas Turbine Engines

DTIC Science & Technology

2016-12-01

exchange system within the engine using existing blade surfaces to extract and insert heat. Due to the highly turbulent and transient flow, heat...transfer coefficients in turbomachinery are extremely high, making this possible. Heat transfer between the turbine and compressor blade surfaces could be...exchange system within the engine using existing blade surfaces to extract and insert heat. Due to the highly turbulent and transient flow, heat transfer

Use of CFD Analyses to Predict Disk Friction Loss of Centrifugal Compressor Impellers

NASA Astrophysics Data System (ADS)

Cho, Leesang; Lee, Seawook; Cho, Jinsoo

To improve the total efficiency of centrifugal compressors, it is necessary to reduce disk friction loss, which is expressed as the power loss. In this study, to reduce the disk friction loss due to the effect of axial clearance and surface roughness is analyzed and methods to reduce disk friction loss are proposed. The rotating reference frame technique using a commercial CFD tool (FLUENT) is used for steady-state analysis of the centrifugal compressor. Numerical results of the CFD analysis are compared with theoretical results using established experimental empirical equations. The disk friction loss of the impeller is decreased in line with increments in axial clearance until the axial clearance between the impeller disk and the casing is smaller than the boundary layer thickness. In addition, the disk friction loss of the impeller is increased in line with the increments in surface roughness in a similar pattern as that of existing experimental empirical formulas. The disk friction loss of the impeller is more affected by the surface roughness than the change of the axial clearance. To minimize disk friction loss on the centrifugal compressor impeller, the axial clearance and the theoretical boundary layer thickness should be designed to be the same. The design of the impeller requires careful consideration in order to optimize axial clearance and minimize surface roughness.

Underground pipeline laying using the pipe-in-pipe system

NASA Astrophysics Data System (ADS)

Antropova, N.; Krets, V.; Pavlov, M.

2016-09-01

The problems of resource saving and environmental safety during the installation and operation of the underwater crossings are always relevant. The paper describes the existing methods of trenchless pipeline technology, the structure of multi-channel pipelines, the types of supporting and guiding systems. The rational design is suggested for the pipe-in-pipe system. The finite element model is presented for the most dangerous sections of the inner pipes, the optimum distance is detected between the roller supports.

Pipeline corridors through wetlands - impacts on plant communities: Bayou Grand Cane, De Soto Parish, Louisiana. Topical report, August 1991--July 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shem, L.M.; Zimmerman, R.E.; Hayes, D.

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipeline on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and night of-way (ROW) management practices. This report presents the results of a survey conducted over the period of August 12-13, 1991, at the Bayou Grand Cane crossing in De Soto Parish, Louisiana, where a pipeline constructed three years prior to the survey crosses the bayou through mature bottomland hardwoods. The sit was notmore » seeded or fertilized after construction activities. At the time of sampling, a dense herb stratum (composed of mostly native species) covered the 20-m-wide ROW, except within drainage channels. As a result of the creation of the ROW, new habitat was created, plant diversity increased, and forest habitat became fragmented. The ROW must be maintained at an early stage of succession to allow access to the pipeline however, impacts to the wetland were minimized by decreasing the width of the ROW to 20 m and recreating the drainage channels across the ROW. The canopy trees on the ROW`s edge shaded part of the ROW, which helped to minimize the effects of the ROW.« less

Study of a Wake Recovery Mechanism in a High-Speed Axial Compressor Stage

NASA Technical Reports Server (NTRS)

VanZante, Dale E.

1998-01-01

This work addresses the significant differences in compressor rotor wake mixing loss which exist in a stage environment relative to a rotor in isolation. The wake decay for a rotor in isolation is due solely to viscous dissipation which is an irreversible process and thus leads to a loss in both total pressure and efficiency. Rotor wake decay in the stage environment is due to both viscous mixing and the inviscid strain imposed on the wake fluid particles by the stator velocity field. This straining process, referred to by Smith (1993) as recovery, is reversible and for a 2D rotor wake leads to an inviscid reduction of the velocity deficit of the wake. A model for the rotor wake decay process is developed and used to quantify the viscous dissipation effects relative to those of inviscid wake stretching. The model is verified using laser anemometer measurements acquired in the wake of a transonic rotor operated in isolation and in a stage configuration at near peak efficiency and near stall operating conditions. Additional insight is provided by a time-accurate 3D Navier-Stokes simulation of the compressor stator flow field at the corresponding stage loading levels. Results from the wake decay model exhibit good agreement with the experimental data. Data from the model, laser anemometer measurements, and numerical simulations indicate that for the rotor/stator spacing used in this work, which is typical of core compressors, rotor wake straining (stretching) is the primary decay process in the stator passage with viscous mixing playing only a minor role. The implications of these results on compressor stage design are discussed.

75 FR 62533 - Destin Pipeline Company, L.L.C.; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-12

... existing 36-inch pipeline and Gulf LNG's Destin Meter Station that will consist of a new 36-inch hot tap..., protests, and interventions via the Internet in lieu of paper. See 18 CFR 385.2001(a)(1)(iii) and the...

78 FR 26350 - Columbia Gas Transmission, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-06

... installation of a pig launcher \\2\\, a pig receiver, and a mainline valve. According to Columbia, its project is... constructed parallel to an existing pipeline to increase capacity. \\2\\ A ``pig'' is a tool that the pipeline...

Computer models of complex multiloop branched pipeline systems

NASA Astrophysics Data System (ADS)

Kudinov, I. V.; Kolesnikov, S. V.; Eremin, A. V.; Branfileva, A. N.

2013-11-01

This paper describes the principal theoretical concepts of the method used for constructing computer models of complex multiloop branched pipeline networks, and this method is based on the theory of graphs and two Kirchhoff's laws applied to electrical circuits. The models make it possible to calculate velocities, flow rates, and pressures of a fluid medium in any section of pipeline networks, when the latter are considered as single hydraulic systems. On the basis of multivariant calculations the reasons for existing problems can be identified, the least costly methods of their elimination can be proposed, and recommendations for planning the modernization of pipeline systems and construction of their new sections can be made. The results obtained can be applied to complex pipeline systems intended for various purposes (water pipelines, petroleum pipelines, etc.). The operability of the model has been verified on an example of designing a unified computer model of the heat network for centralized heat supply of the city of Samara.

External corrosion and leakage detection of oil and gas pipeline using FBG fiber optics and a trigger

NASA Astrophysics Data System (ADS)

Ge, Yaomou

Oil and gas pipelines play a critical role in delivering the energy resources from producing fields to power communities around the world. However, there are many threats to pipeline integrity, which may lead to significant incidents, causing safety, environmental and economic problems. Corrosion has been a big threat to oil and gas pipelines for a long time, which has attributed to approximately 18% of the significant incidents in oil and gas pipelines. In addition, external corrosion of pipelines accounts for a significant portion (more than 25%) of pipeline failure. External corrosion detection is the research area of this thesis. In this thesis, a review of existing corrosion detection or monitoring methods is presented, and optical fiber sensors show a great promise in corrosion detection of oil and gas pipelines. Several scenarios of optical fiber corrosion sensors are discussed, and two of them are selected for future research. A new corrosion and leakage detection sensor, consisting of a custom designed trigger and a FBG optical fiber, will be presented. This new device has been experimentally tested and it shows great promise.

Modelling the pressurization induced by solar radiation on above ground installations of LPG pipeline systems

NASA Astrophysics Data System (ADS)

Leporini, M.; Terenzi, A.; Marchetti, B.; Giacchetta, G.; Polonara, F.; Corvaro, F.; Cocci Grifoni, R.

2017-11-01

Pipelining Liquefied Petroleum Gas (LPG) is a mode of LPG transportation more environmentally-friendly than others due to the lower energy consumption and exhaust emissions. Worldwide, there are over 20000 kilometers of LPG pipelines. There are a number of codes that industry follows for the design, fabrication, construction and operation of liquid LPG pipelines. However, no standards exist to modelling particular critical phenomena which can occur on these lines due to external environmental conditions like the solar radiation pressurization. In fact, the solar radiation can expose above ground pipeline sections at pressure values above the maximum Design Pressure with resulting risks and problems. The present work presents an innovative practice suitable for the Oil & Gas industry to modelling the pressurization induced by the solar radiation on above ground LPG pipeline sections with the application to a real case.

Viability of using different types of main oil pipelines pump drives

NASA Astrophysics Data System (ADS)

Zakirzakov, A. G.; Zemenkov, Yu D.; Akulov, K. A.

2018-05-01

The choice of the pumping units' drive of main oil pipelines is of great importance both for design of pipelines and for modernization of existing ones. At the beginning of oil pipeline transport development, due to the limited number and types of energy sources, the choice was not difficult. The combustion energy of the pumped product was often the only available energy resource for its transportation. In this regard, the pipelines that had autonomous energy sources favorably differed from other energy consumers in the sector. With the passage of time, with the development of the country's electricity supply system, the electric drive for power-line equipment of oil pipelines becomes the dominant type of a pumping station drive. Nowadays, the traditional component is an essential factor when choosing some type of the drive. For many years, oil companies have been using electric drives for pumps, while gas transport enterprises prefer self-contained gas turbines.

Modeling and Prototyping of Automatic Clutch System for Light Vehicles

NASA Astrophysics Data System (ADS)

Murali, S.; Jothi Prakash, V. M.; Vishal, S.

2017-03-01

Nowadays, recycling or regenerating the waste in to something useful is appreciated all around the globe. It reduces greenhouse gas emissions that contribute to global climate change. This study deals with provision of the automatic clutch mechanism in vehicles to facilitate the smooth changing of gears. This study proposed to use the exhaust gases which are normally expelled out as a waste from the turbocharger to actuate the clutch mechanism in vehicles to facilitate the smooth changing of gears. At present, clutches are operated automatically by using an air compressor in the four wheelers. In this study, a conceptual design is proposed in which the clutch is operated by the exhaust gas from the turbocharger and this will remove the usage of air compressor in the existing system. With this system, usage of air compressor is eliminated and the riders need not to operate the clutch manually. This work involved in development, analysation and validation of the conceptual design through simulation software. Then the developed conceptual design of an automatic pneumatic clutch system is tested with proto type.

Numerical simulation of compressor endwall and casing treatment flow phenomena

NASA Technical Reports Server (NTRS)

Crook, A. J.; Greitzer, E. M.; Tan, C. S.; Adamczyk, J. J.

1992-01-01

A numerical study is presented of the flow in the endwall region of a compressor blade row, in conditions of operation with both smooth and grooved endwalls. The computations are first compared to velocity field measurements in a cantilevered stator/rotating hub configuration to confirm that the salient features are captured. Computations are then interrogated to examine the tip leakage flow structure since this is a dominant feature of the endwall region. In particular, the high blockage that can exist near the endwalls at the rear of a compressor blade passage appears to be directly linked to low total pressure fluid associated with the leakage flow. The fluid dynamic action of the grooved endwall, representative of the casing treatments that have been most successful in suppressing stall, is then simulated computationally and two principal effects are identified. One is suction of the low total pressure, high blockage fluid at the rear of the passage. The second is energizing of the tip leakage flow, most notably in the core of the leakage vortex, thereby suppressing the blockage at its source.

Performance Charts for a Turbojet System

NASA Technical Reports Server (NTRS)

Karp, Irving M.

1947-01-01

Convenient charts are presented for computing the thrust, fuel consumption, and other performance values of a turbojet system. These charts take into account the effects of ram pressure, compressor pressure ratio, ratio of combustion-chamber-outlet temperature to atmospheric temperature, compressor efficiency, turbine efficiency, combustion efficiency, discharge-nozzle coefficient, losses in total pressure in the inlet to the jet-propulsion unit and in the combustion chamber, and variation in specific heats with temperature. The principal performance charts show clearly the effects of the primary variables and correction charts provide the effects of the secondary variables. The performance of illustrative cases of turbojet systems is given. It is shown that maximum thrust per unit mass rate of air flow occurs at a lower compressor pressure ratio than minimum specific fuel consumption. The thrust per unit mass rate of air flow increases as the combustion-chamber discharge temperature increases. For minimum specific fuel consumption, however, an optimum combustion-chamber discharge temperature exists, which in some cases may be less than the limiting temperature imposed by the strength temperature characteristics of present materials.

Early-type galaxies: Automated reduction and analysis of ROSAT PSPC data

NASA Technical Reports Server (NTRS)

Mackie, G.; Fabbiano, G.; Harnden, F. R., Jr.; Kim, D.-W.; Maggio, A.; Micela, G.; Sciortino, S.; Ciliegi, P.

1996-01-01

Preliminary results of early-type galaxies that will be part of a galaxy catalog to be derived from the complete Rosat data base are presented. The stored data were reduced and analyzed by an automatic pipeline. This pipeline is based on a command language scrip. The important features of the pipeline include new data time screening in order to maximize the signal to noise ratio of faint point-like sources, source detection via a wavelet algorithm, and the identification of sources with objects from existing catalogs. The pipeline outputs include reduced images, contour maps, surface brightness profiles, spectra, color and hardness ratios.

Corrosivity Sensor for Exposed Pipelines Based on Wireless Energy Transfer

PubMed Central

Lawand, Lydia; Shiryayev, Oleg; Al Handawi, Khalil; Vahdati, Nader; Rostron, Paul

2017-01-01

External corrosion was identified as one of the main causes of pipeline failures worldwide. A solution that addresses the issue of detecting and quantifying corrosivity of environment for application to existing exposed pipelines has been developed. It consists of a sensing array made of an assembly of thin strips of pipeline steel and a circuit that provides a visual sensor reading to the operator. The proposed sensor is passive and does not require a constant power supply. Circuit design was validated through simulations and lab experiments. Accelerated corrosion experiment was conducted to confirm the feasibility of the proposed corrosivity sensor design. PMID:28556805

Counterrotatable booster compressor assembly for a gas turbine engine

NASA Technical Reports Server (NTRS)

Moniz, Thomas Ory (Inventor); Orlando, Robert Joseph (Inventor)

2004-01-01

A counterrotatable booster compressor assembly for a gas turbine engine having a counterrotatable fan section with a first fan blade row connected to a first drive shaft and a second fan blade row axially spaced from the first fan blade row and connected to a second drive shaft, the counterrotatable booster compressor assembly including a first compressor blade row connected to the first drive shaft and a second compressor blade row interdigitated with the first compressor blade row and connected to the second drive shaft. A portion of each fan blade of the second fan blade row extends through a flowpath of the counterrotatable booster compressor so as to function as a compressor blade in the second compressor blade row. The counterrotatable booster compressor further includes a first platform member integral with each fan blade of the second fan blade row at a first location so as to form an inner flowpath for the counterrotatable booster compressor and a second platform member integral with each fan blade of the second fan blade row at a second location so as to form an outer flowpath for the counterrotatable booster compressor.

49 CFR 192.245 - Repair or removal of defects.

Code of Federal Regulations, 2013 CFR

2013-10-01

... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192... be preheated if conditions exist which would adversely affect the quality of the weld repair. After... minimum mechanical properties specified for the welding procedure used to make the original weld are met...

49 CFR 192.245 - Repair or removal of defects.

Code of Federal Regulations, 2011 CFR

2011-10-01

... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192... be preheated if conditions exist which would adversely affect the quality of the weld repair. After... minimum mechanical properties specified for the welding procedure used to make the original weld are met...

49 CFR 192.245 - Repair or removal of defects.

Code of Federal Regulations, 2014 CFR

2014-10-01

... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192... be preheated if conditions exist which would adversely affect the quality of the weld repair. After... minimum mechanical properties specified for the welding procedure used to make the original weld are met...

49 CFR 192.245 - Repair or removal of defects.

Code of Federal Regulations, 2012 CFR

2012-10-01

... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192... be preheated if conditions exist which would adversely affect the quality of the weld repair. After... minimum mechanical properties specified for the welding procedure used to make the original weld are met...

49 CFR 192.245 - Repair or removal of defects.

Code of Federal Regulations, 2010 CFR

2010-10-01

... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192... be preheated if conditions exist which would adversely affect the quality of the weld repair. After... minimum mechanical properties specified for the welding procedure used to make the original weld are met...

ORAC-DR: Pipelining With Other People's Code

NASA Astrophysics Data System (ADS)

Economou, Frossie; Bridger, Alan; Wright, Gillian S.; Jenness, Tim; Currie, Malcolm J.; Adamson, Andy

As part of the UKIRT ORAC project, we have developed a pipeline (orac-dr) for driving on-line data reduction using existing astronomical packages as algorithm engines and display tools. The design is modular and extensible on several levels, allowing it to be easily adapted to a wide variety of instruments. Here we briefly review the design, discuss the robustness and speed of execution issues inherent in such pipelines, and address what constitutes a desirable (in terms of ``buy-in'' effort) engine or tool.

Using industry ROV videos to assess fish associations with subsea pipelines

NASA Astrophysics Data System (ADS)

McLean, D. L.; Partridge, J. C.; Bond, T.; Birt, M. J.; Bornt, K. R.; Langlois, T. J.

2017-06-01

Remote Operated Vehicles are routinely used to undertake inspection and maintenance activities of underwater pipelines in north-west Australia. In doing so, many terabytes of geo-referenced underwater video are collected at depths, and on a scale usually unobtainable for ecological research. We assessed fish diversity and abundance from existing ROV videos collected along 2-3 km sections of two pipelines in north-west Australia, one at 60-80 m water depth and the other at 120-130 m. A total of 5962 individual fish from 92 species and 42 families were observed. Both pipelines were characterised by a high abundance of commercially important fishes including: snappers (Lutjanidae) and groupers (Epinephelidae). The presence of thousands of unidentifiable larval fish, in addition to juveniles, sub-adults and adults suggests that the pipelines may be enhancing, rather than simply attracting, fish stocks. The prevalence and high complexity of sponges on the shallower pipeline and of deepwater corals on the deeper pipeline had a strong positive correlation with the fish abundance. These habitats likely offer a significant food source and refuge for fish, but also for invertebrates upon which fish feed. A greater diversity on the shallower pipeline, and a higher abundance of fishes on both pipelines, were associated with unsupported pipeline sections (spans) and many species appeared to be utilising pipeline spans as refuges. This study is a first look at the potential value of subsea pipelines for fishes on the north-west shelf. While the results suggest that these sections of pipeline appear to offer significant habitat that supports diverse and important commercially fished species, further work, including off-pipeline surveys on the natural seafloor, are required to determine conclusively the ecological value of pipelines and thereby inform discussions regarding the ecological implications of pipeline decommissioning.

The measurement of boundary layers on a compressor blade in cascade. Volume 2: Data tables

NASA Technical Reports Server (NTRS)

Zierke, William C.; Deutsch, Steven

1989-01-01

Measurements were made of the boundary layers and wakes about a highly loaded, double-circular-arc compressor blade in cascade. These laser Doppler velocimetry measurements have yielded a very detailed and precise data base with which to test the application of viscous computational codes to turbomachinery. In order to test the computational codes at off-design conditions, the data have been acquired at a chord Reynolds number of 500,000 and at three incidence angles. Average values and 95 percent confidence bands were tabularized for the velocity, local turbulence intensity, skewness, kurtosis, and percent backflow. Tables also exist for the blade static-pressure distributions and boundary layer velocity profiles reconstructed to account for the normal pressure gradient.

Development of an Experimental Data Base to Validate Compressor-Face Boundary Conditions Used in Unsteady Inlet Flow Computations

NASA Technical Reports Server (NTRS)

Sajben, Miklos; Freund, Donald D.

1998-01-01

The ability to predict the dynamics of integrated inlet/compressor systems is an important part of designing high-speed propulsion systems. The boundaries of the performance envelope are often defined by undesirable transient phenomena in the inlet (unstart, buzz, etc.) in response to disturbances originated either in the engine or in the atmosphere. Stability margins used to compensate for the inability to accurately predict such processes lead to weight and performance penalties, which translate into a reduction in vehicle range. The prediction of transients in an inlet/compressor system requires either the coupling of two complex, unsteady codes (one for the inlet and one for the engine) or else a reliable characterization of the inlet/compressor interface, by specifying a boundary condition. In the context of engineering development programs, only the second option is viable economically. Computations of unsteady inlet flows invariably rely on simple compressor-face boundary conditions (CFBC's). Currently, customary conditions include choked flow, constant static pressure, constant axial velocity, constant Mach number or constant mass flow per unit area. These conditions are straightforward extensions of practices that are valid for and work well with steady inlet flows. Unfortunately, it is not at all likely that any flow property would stay constant during a complex system transient. At the start of this effort, no experimental observation existed that could be used to formulate of verify any of the CFBC'S. This lack of hard information represented a risk for a development program that has been recognized to be unacceptably large. The goal of the present effort was to generate such data. Disturbances reaching the compressor face in flight may have complex spatial structures and temporal histories. Small amplitude disturbances may be decomposed into acoustic, vorticity and entropy contributions that are uncoupled if the undisturbed flow is uniform. This study is focused on the response of an inlet/compressor system to acoustic disturbances. From the viewpoint of inlet computations, acoustic disturbances are clearly the most important, since they are the only ones capable of moving upstream. Convective and entropy disturbances may also produce upstream-moving acoustic waves, but such processes are outside the scope of the present study.

Study Improving Performance of Centrifugal Compressor In Paiton Coal Fired Power Plant Unit 1 And 2

NASA Astrophysics Data System (ADS)

Kusuma, Yuriadi; Permana, Dadang S.

2018-03-01

The compressed air system becomes part of a very important utility system in a Plant, including the Steam Power Plant. In PLN’S coal fired power plant, Paiton units 1 and 2, there are four Centrifugal air compressor types, which produce compressed air as much as 5.652 cfm and with electric power capacity of 1200 kW. Electricity consumption to operate centrifugal compressor is 7.104.117 kWh per year. This study aims to measure the performance of Centrifugal Compressors operating in Paiton’s coal fired power plant units 1 and 2. Performance Compressor is expressed by Specific Power Consumption (SPC) in kW/100 cfm. For this purpose, we measure the compressed air flow rate generated by each compressor and the power consumed by each compressor. The result is as follows Air Compressor SAC 2B : 15.1 kW/100 cfm, Air Compressor SAC 1B : 15.31 kW/100 cfm,Air Compressor SAC 1A : 16.3 kW/100 cfm and air Compressor SAC 2C : 18.19 kW/100 cfm. From the measurement result, air compressor SAC 2B has the best performance that is 15.1 kW / 100 cfm. In this study we analyze efforts to improve the performance of other compressors to at least match the performance of the SAC 2B air compressor. By increasing the Specific Power Consumption from others Compressor, it will get energy saving up to 284,165 kWh per year.

The impact analysis of the connecting pipe length and diameter on the operation of a piston hybrid power machine of positive displacement with gas suction capacity

NASA Astrophysics Data System (ADS)

Shcherba, V. E.; Grigoriev, A. V.; Averyanov, G. S.; Surikov, V. I.; Vedruchenko, V. P.; Galdin, N. S.; Trukhanova, D. A.

2017-08-01

The article analyzes the impact of the connecting liquid pipe length and diameter on consumables and power characteristics of the piston hybrid power machine with gas suction capacity. The following operating characteristics of the machine were constructed and analyzed: the average height of the liquid column in the jacket space; instantaneous velocity and height of the liquid column in the jacket space; the relative height of the liquid column in the jacket space; volumetric efficiency; indicator isothermal efficiency; flowrate in the pump section; relative pressure losses during suction; relative flowrate. The dependence of the instantaneous pressure in the work space and the suction space of the compressor section on the rotation angle of the crankshaft is determined for different values of the length and diameter of the connecting pipeline.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dyachenko, Sergey A.; Zlotnik, Anatoly; Korotkevich, Alexander O.

Here, we develop an operator splitting method to simulate flows of isothermal compressible natural gas over transmission pipelines. The method solves a system of nonlinear hyperbolic partial differential equations (PDEs) of hydrodynamic type for mass flow and pressure on a metric graph, where turbulent losses of momentum are modeled by phenomenological Darcy-Weisbach friction. Mass flow balance is maintained through the boundary conditions at the network nodes, where natural gas is injected or withdrawn from the system. Gas flow through the network is controlled by compressors boosting pressure at the inlet of the adjoint pipe. Our operator splitting numerical scheme ismore » unconditionally stable and it is second order accurate in space and time. The scheme is explicit, and it is formulated to work with general networks with loops. We test the scheme over range of regimes and network configurations, also comparing its performance with performance of two other state of the art implicit schemes.« less

Apparatus for the liquefaction of natural gas and methods relating to same

DOEpatents

Wilding, Bruce M [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID; Turner, Terry D [Ammon, ID; Carney, Francis H [Idaho Falls, ID

2009-09-29

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work output. A compressor may be driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream.

New Colombian gas line overcomes desert, marshland, hilly terrain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1977-02-28

Wind-swept deserts, rock hills, and tricky swamps are some of the main obstacles being faced in the construction of a major Colombian pipeline for Promigas, a Colombian gas-marketing firm. The 236-mile (380-km), 20 and 12-in. transmission system will link the onshore and offshore Guajira Peninsula fields with the industrial cities of Barranquilla and Cartagena as part of an ambitious gas-utilization program aimed at substituting imported fuel oil in industrial operations at these cities and creating a sizable gas-processing and liquefaction complex at Palomino. Scheduled for completion in October 1977, the $60 million gas line will deliver up to 900 millionmore » cf/day of untreated, 98 mol % methane gas without the use of compressor stations because of the 1400-psi reservoir pressure. The estimated potential of the field is expected to support this production rate for at least 15 years.« less

Field tests prove microscale NRU to upgrade low-btu gas

USGS Publications Warehouse

Bhattacharya, Saibal; Newell, K. David; Watney, W. Lynn; Sigel, Micael

2009-01-01

The Kansas Geological Survey (University of Kansas) and the American Energies Corp., Wichita, have conducted field tests of a scalable, microscale, N2-rejection unit (NRU) to demonstrate its effectiveness to upgrade low-pressure ((<100 psig) and low-volume (=100 Mcfd) low-btu gas to pipeline quality. The tests aim to develop inexpensive NRU technology, which is designed for low- volume, low-pressure gas wells, to significantly increase the contribution of marginal low-btu gas to the gas supply of the US. The NRU uses two towers and uses three stages, namely, adsorption under pressure, venting to 2 psig, and desorption under vacuum. The modular design allows additional sets of towers to be added or removed to handle increases or decreases in feed volumes. The field tests also reveal that a strong compressor, which is capable of evacuating the tower (volume) as quickly as possible, should be employed to reduce process cycle time and increase plant throughput.

Apparatus for the liquefaction of natural gas and methods relating to same

DOEpatents

Turner, Terry D [Ammon, ID; Wilding, Bruce M [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID

2009-09-22

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through an expander creating work output. A compressor may be driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates a vapor from the liquid natural gas. A portion of the liquid gas is used for additional cooling. Gas produced within the system may be recompressed for reintroduction into a receiving line or recirculation within the system for further processing.

St. Fergus terminal gets turboexpanders for critical service

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lillard, J.K.; Nicol, G.

1994-09-05

To expand the St. Fergus gas-reception terminal for the Scottish Area Gas Evacuation (SAGE) system, Mobil North Sea Ltd. is adding a second separation train and two treatment trains. To meet pipeline-gas specifications over a wide range of low rates and feed-gas compositions, single-stage turboexpander chilling was selected over Joule-Thomson valve expansion. Four turboexpanders (two per process train) will operate in parallel to achieve the required performance over the entire flow range of 90--575 MMscfd per process train. Unusual operating conditions for the turboexpanders include dense-phase inlet gas, expansion near the cricondenbar, and high equilibrium liquid content at the exhaustmore » (up to 50 wt %). The two turboexpanders in each train share common suction and discharge facilities as do their associated brake compressor. Details of the more than 400 million pounds Sterling Phase B discussed here include commissioning, start-up, and operation.« less

Unconventional oil and gas extraction and animal health.

PubMed

Bamberger, M; Oswald, R E

2014-08-01

The extraction of hydrocarbons from shale formations using horizontal drilling with high volume hydraulic fracturing (unconventional shale gas and tight oil extraction), while derived from methods that have been used for decades, is a relatively new innovation that was introduced first in the United States and has more recently spread worldwide. Although this has led to the availability of new sources of fossil fuels for domestic consumption and export, important issues have been raised concerning the safety of the process relative to public health, animal health, and our food supply. Because of the multiple toxicants used and generated, and because of the complexity of the drilling, hydraulic fracturing, and completion processes including associated infrastructure such as pipelines, compressor stations and processing plants, impacts on the health of humans and animals are difficult to assess definitively. We discuss here findings concerning the safety of unconventional oil and gas extraction from the perspectives of public health, veterinary medicine, and food safety.

Energy stores and switches for rail-launcher systems

NASA Technical Reports Server (NTRS)

Weldon, W. F.; Zowarka, R. C.; Marshall, R. A.

1983-01-01

An overview of existing switch and power supply technology applicable to space launch, a new candidate pulsed power supply for Earth-to-space rail launcher duty, the inverse railgun flux compressor, and a set of switching experiments to study further the feasibility of Earth-to-space launch are discussed.

77 FR 26543 - UGI Storage Company; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-04

... approximately 3,450 horsepower (hp) of gas fired compression at its existing Palmer Station in Tioga County... compressor units and one 690 hp unit at the Palmer Station located at the downstream terminus of the TL-94...-3-12; 8:45 am] BILLING CODE 6717-01-P ...

77 FR 16865 - Proposed Extension of Existing Information Collection; Occupational Noise Exposure

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-22

..., administrative controls, and personal protective equipment to protect miners from harmful levels of noise that..., compressors, conveyors, trucks, loaders, and other heavy-duty equipment for the excavation, haulage, and processing of material. This equipment creates high sound levels, exposing machine operators as well as...

Energy stores and switches for rail-launcher systems

NASA Astrophysics Data System (ADS)

Weldon, W. F.; Zowarka, R. C.; Marshall, R. A.

An overview of existing switch and power supply technology applicable to space launch, a new candidate pulsed power supply for Earth-to-space rail launcher duty, the inverse railgun flux compressor, and a set of switching experiments to study further the feasibility of Earth-to-space launch are discussed.

Turbo-alternator-compressor design for supercritical high density working fluids

DOEpatents

Wright, Steven A.; Fuller, Robert L.

2013-03-19

Techniques for generating power are provided. Such techniques involve a thermodynamic system including a housing, a turbine positioned in a turbine cavity of the housing, a compressor positioned in a compressor cavity of the housing, and an alternator positioned in a rotor cavity between the turbine and compressor cavities. The compressor has a high-pressure face facing an inlet of the compressor cavity and a low-pressure face on an opposite side thereof. The alternator has a rotor shaft operatively connected to the turbine and compressor, and is supported in the housing by bearings. Ridges extending from the low-pressure face of the compressor may be provided for balancing thrust across the compressor. Seals may be positioned about the alternator for selectively leaking fluid into the rotor cavity to reduce the temperature therein.

Numerical research on the lateral global buckling characteristics of a high temperature and pressure pipeline with two initial imperfections

PubMed Central

Liu, Wenbin; Liu, Aimin

2018-01-01

With the exploitation of offshore oil and gas gradually moving to deep water, higher temperature differences and pressure differences are applied to the pipeline system, making the global buckling of the pipeline more serious. For unburied deep-water pipelines, the lateral buckling is the major buckling form. The initial imperfections widely exist in the pipeline system due to manufacture defects or the influence of uneven seabed, and the distribution and geometry features of initial imperfections are random. They can be divided into two kinds based on shape: single-arch imperfections and double-arch imperfections. This paper analyzed the global buckling process of a pipeline with 2 initial imperfections by using a numerical simulation method and revealed how the ratio of the initial imperfection’s space length to the imperfection’s wavelength and the combination of imperfections affects the buckling process. The results show that a pipeline with 2 initial imperfections may suffer the superposition of global buckling. The growth ratios of buckling displacement, axial force and bending moment in the superposition zone are several times larger than no buckling superposition pipeline. The ratio of the initial imperfection’s space length to the imperfection’s wavelength decides whether a pipeline suffers buckling superposition. The potential failure point of pipeline exhibiting buckling superposition is as same as the no buckling superposition pipeline, but the failure risk of pipeline exhibiting buckling superposition is much higher. The shape and direction of two nearby imperfections also affects the failure risk of pipeline exhibiting global buckling superposition. The failure risk of pipeline with two double-arch imperfections is higher than pipeline with two single-arch imperfections. PMID:29554123

Aerodynamic Design of Axial Flow Compressors

NASA Technical Reports Server (NTRS)

Bullock, R. O. (Editor); Johnsen, I. A.

1965-01-01

An overview of 'Aerodynamic systems design of axial flow compressors' is presented. Numerous chapters cover topics such as compressor design, ptotential and viscous flow in two dimensional cascades, compressor stall and blade vibration, and compressor flow theory. Theoretical aspects of flow are also covered.

Near-term deployment of carbon capture and sequestration from biorefineries in the United States.

PubMed

Sanchez, Daniel L; Johnson, Nils; McCoy, Sean T; Turner, Peter A; Mach, Katharine J

2018-05-08

Capture and permanent geologic sequestration of biogenic CO 2 emissions may provide critical flexibility in ambitious climate change mitigation. However, most bioenergy with carbon capture and sequestration (BECCS) technologies are technically immature or commercially unavailable. Here, we evaluate low-cost, commercially ready CO 2 capture opportunities for existing ethanol biorefineries in the United States. The analysis combines process engineering, spatial optimization, and lifecycle assessment to consider the technical, economic, and institutional feasibility of near-term carbon capture and sequestration (CCS). Our modeling framework evaluates least cost source-sink relationships and aggregation opportunities for pipeline transport, which can cost-effectively transport small CO 2 volumes to suitable sequestration sites; 216 existing US biorefineries emit 45 Mt CO 2 annually from fermentation, of which 60% could be captured and compressed for pipeline transport for under $25/tCO 2 A sequestration credit, analogous to existing CCS tax credits, of $60/tCO 2 could incent 30 Mt of sequestration and 6,900 km of pipeline infrastructure across the United States. Similarly, a carbon abatement credit, analogous to existing tradeable CO 2 credits, of $90/tCO 2 can incent 38 Mt of abatement. Aggregation of CO 2 sources enables cost-effective long-distance pipeline transport to distant sequestration sites. Financial incentives under the low-carbon fuel standard in California and recent revisions to existing federal tax credits suggest a substantial near-term opportunity to permanently sequester biogenic CO 2 This financial opportunity could catalyze the growth of carbon capture, transport, and sequestration; improve the lifecycle impacts of conventional biofuels; support development of carbon-negative fuels; and help fulfill the mandates of low-carbon fuel policies across the United States. Copyright © 2018 the Author(s). Published by PNAS.

Near-term deployment of carbon capture and sequestration from biorefineries in the United States

PubMed Central

Johnson, Nils; McCoy, Sean T.; Turner, Peter A.; Mach, Katharine J.

2018-01-01

Capture and permanent geologic sequestration of biogenic CO2 emissions may provide critical flexibility in ambitious climate change mitigation. However, most bioenergy with carbon capture and sequestration (BECCS) technologies are technically immature or commercially unavailable. Here, we evaluate low-cost, commercially ready CO2 capture opportunities for existing ethanol biorefineries in the United States. The analysis combines process engineering, spatial optimization, and lifecycle assessment to consider the technical, economic, and institutional feasibility of near-term carbon capture and sequestration (CCS). Our modeling framework evaluates least cost source–sink relationships and aggregation opportunities for pipeline transport, which can cost-effectively transport small CO2 volumes to suitable sequestration sites; 216 existing US biorefineries emit 45 Mt CO2 annually from fermentation, of which 60% could be captured and compressed for pipeline transport for under $25/tCO2. A sequestration credit, analogous to existing CCS tax credits, of $60/tCO2 could incent 30 Mt of sequestration and 6,900 km of pipeline infrastructure across the United States. Similarly, a carbon abatement credit, analogous to existing tradeable CO2 credits, of $90/tCO2 can incent 38 Mt of abatement. Aggregation of CO2 sources enables cost-effective long-distance pipeline transport to distant sequestration sites. Financial incentives under the low-carbon fuel standard in California and recent revisions to existing federal tax credits suggest a substantial near-term opportunity to permanently sequester biogenic CO2. This financial opportunity could catalyze the growth of carbon capture, transport, and sequestration; improve the lifecycle impacts of conventional biofuels; support development of carbon-negative fuels; and help fulfill the mandates of low-carbon fuel policies across the United States. PMID:29686063

Beyond School-to-Prison Pipeline and toward an Educational and Penal Realism

ERIC Educational Resources Information Center

Fasching-Varner, Kenneth J.; Mitchell, Roland W.; Martin, Lori L.; Bennett-Haron, Karen P.

2014-01-01

Much scholarly attention has been paid to the school-to-prison pipeline and the sanitized discourse of "death by education," called the achievement gap. Additionally, there exists a longstanding discourse surrounding the alleged crisis of educational failure. This article offers no solutions to the crisis and suggests instead that the…

78 FR 63176 - Notice of Preliminary Determination of a Qualifying Conduit Hydropower Facility and Soliciting...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-23

... new ``y'' pipe intake off the existing 10-inch diameter water supply pipeline; (2) a new 12-foot-long... water supply pipeline; and (5) appurtenant facilities. The proposed project would have an estimated... 22 kW Orchard City Water Treatment Plant Hydroelectric Project would utilize Orchard City's water...

Simulation of pipeline in the area of the underwater crossing

NASA Astrophysics Data System (ADS)

Burkov, P.; Chernyavskiy, D.; Burkova, S.; Konan, E. C.

2014-08-01

The article studies stress-strain behavior of the main oil-pipeline section Alexandrovskoye-Anzhero-Sudzhensk using software system Ansys. This method of examination and assessment of technical conditions of objects of pipeline transport studies the objects and the processes that affect the technical condition of these facilities, including the research on the basis of computer simulation. Such approach allows to develop the theory, methods of calculations and designing of objects of pipeline transport, units and parts of machines, regardless of their industry and destination with a view to improve the existing constructions and create new structures, machines of high performance, durability and reliability, maintainability, low material capacity and cost, which have competitiveness on the world market.

iGAS: A framework for using electronic intraoperative medical records for genomic discovery.

PubMed

Levin, Matthew A; Joseph, Thomas T; Jeff, Janina M; Nadukuru, Rajiv; Ellis, Stephen B; Bottinger, Erwin P; Kenny, Eimear E

2017-03-01

Design and implement a HIPAA and Integrating the Healthcare Enterprise (IHE) profile compliant automated pipeline, the integrated Genomics Anesthesia System (iGAS), linking genomic data from the Mount Sinai Health System (MSHS) BioMe biobank to electronic anesthesia records, including physiological data collected during the perioperative period. The resulting repository of multi-dimensional data can be used for precision medicine analysis of physiological readouts, acute medical conditions, and adverse events that can occur during surgery. A structured pipeline was developed atop our existing anesthesia data warehouse using open-source tools. The pipeline is automated using scheduled tasks. The pipeline runs weekly, and finds and identifies all new and existing anesthetic records for BioMe participants. The pipeline went live in June 2015 with 49.2% (n=15,673) of BioMe participants linked to 40,947 anesthetics. The pipeline runs weekly in minimal time. After eighteen months, an additional 3671 participants were enrolled in BioMe and the number of matched anesthetic records grew 21% to 49,545. Overall percentage of BioMe patients with anesthetics remained similar at 51.1% (n=18,128). Seven patients opted out during this time. The median number of anesthetics per participant was 2 (range 1-144). Collectively, there were over 35 million physiologic data points and 480,000 medication administrations linked to genomic data. To date, two projects are using the pipeline at MSHS. Automated integration of biobank and anesthetic data sources is feasible and practical. This integration enables large-scale genomic analyses that might inform variable physiological response to anesthetic and surgical stress, and examine genetic factors underlying adverse outcomes during and after surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

A Comparison Between PSRK and GERG-2004 Equation of State for Simulation of Non-Isothermal Compressible Natural Gases Mixed with Hydrogen in Pipelines / Porównanie równań stanu opracowanych według metody PSRK oraz GERG-2004 wykorzystanych do symulacji zachowania ściśliwych mieszanin gazu ziemnego i wodoru w rurociągach, w warunkach przepływów nie-izotermicznych

NASA Astrophysics Data System (ADS)

Uilhoorn, Frits E.

2013-06-01

In this work, the GERG-2004 equation of state based on a multi-fluid approximation explicit in the reduced Helmholtz energy is compared with the predictive Soave-Redlich-Kwong group contribution method. In the analysis, both equations of state are compared by simulating a non-isothermal transient flow of natural gas and mixed hydrogen-natural gas in pipelines. Besides the flow conditions also linepack-energy and energy consumption of the compressor station are computed. The gas flow is described by a set of partial differential equations resulting from the conservation of mass, momentum and energy. A pipeline section of the Yamal-Europe gas pipeline on Polish territory has been selected for the case study. W artykule dokonano porównania wyników uzyskanych przy wykorzystaniu równania stanu GERG- 2004 opartego na jawnym przybliżeniu wyników dla wielu cieczy w oparciu o zredukowaną energię Helmhotza oraz wyników uzyskanych w oparciu o metodę Soave-Redlich Kwonga. Obydwa równania stanu porównano poprzez przeprowadzenie symulacji stanów przejściowych przepływów gazu ziemnego oraz mieszanin gazu ziemnego i wodoru w rurociągach w warunkach przepływów nie-izotermicznych. Oprócz warunków przepływu, określono energię w napełnionym układzie oraz zużycie energii przez stację kompresora. Przepływ gazu opisano zbiorem równań różniczkowych cząstkowych, wyprowadzonych w oparciu o prawa zachowania masy, pędu i energii. Jako studium przypadku wybrano fragment rurociągu jamalskiego (Yamal- Europa) przebiegającego przez terytorium Polski.

Design and Analysis of an Axial Bypass Compressor Blade in a Supercritical CO2 Gas Turbine

NASA Astrophysics Data System (ADS)

Ishizuka, Takao; Muto, Yasushi; Aritomi, Masanori; Tsuzuki, Nobuyoshi; Kikura, Hiroshige

A supercritical carbon dioxide gas turbine can generate power at a high cycle thermal efficiency, even at modest temperatures of 500-550°C. Consequently, a more reliable and economically advantageous power generation system is achieved by coupling with a Na-cooled fast reactor. This paper mainly describes the bypass compressor (a key component) design and thermal hydraulic analysis using CFD (with FLUENT code). Fluid conditions of the bypass compressor are determined by the cycle calculation of this system. Aerodynamic design was conducted using the loss model described by Cohen et al., which enables the use of several stages while providing total adiabatic efficiency of 21 and 87%, respectivly. Blade shapes were prepared based on flow angles and chord length obtained for the aerodynamic design. In the CFD analysis, the calculated value of the mass flow rate for each stage was adjusted to that of the design. The value of the design outlet pressure was reached at stage No. 16, which is fewer stages than that for design, No. 21. The difference between these stage numbers is attributed to the three-dimensional effect in design. If these effects are eliminated, then the design calculation yields an almost identical number of stages. Therefore, it was concluded that the existing design method is applicable to the supercritical CO2 bypass compressor. Furthermore, CFD analysis appears to be an effective aerodynamic design tool, but these conclusions should be verified experimentally.

Compact high-efficiency linear cryocooler in single-piston moving magnet design for HOT detectors

NASA Astrophysics Data System (ADS)

Rühlich, I.; Mai, M.; Rosenhagen, C.; Withopf, A.; Zehner, S.

2012-06-01

State of the art Mid Wave IR-technology has the potential to rise the FPA temperature from 77K to 130-150K (High Operation Temperature, HOT). Using a HOT FPA will significantly lower SWaP and keep those parameters finally dominated by the employed cryocooler. Therefore, compact high performance cryocoolers are mandatory. AIM has developed the SX040 cooler, optimized for FPA temperatures of about 95K (presented at SPIE 2010). The SX040 cooler incorporates a high efficient dual piston driving mechanism resulting in a very compact compressor of less than 100mm length. Higher compactness - especially shorter compressors - can be achieved by change from dual to single piston design. The new SX030 compressor has such a single piston Moving Magnet driving mechanism resulting in a compressor length of about 60mm. Common for SX040 and SX030 family is a Moving Magnet driving mechanism with coils placed outside the helium vessel. In combination with high performance plastics for the piston surfaces this design enables lifetimes in excess of 20,000h MTTF. Because of the higher FPA temperature and a higher operating frequency also a new displacer needs to be developed. Based on the existing 1/4" coldfinger interface AIM developed a new displacer optimized for an FPA temperature of 140K and above. This paper gives an overview on the development of this new compact single piston cryocooler. Technical details and performance data will be shown.

Rotor-generated unsteady aerodynamic interactions in a 1½ stage compressor

NASA Astrophysics Data System (ADS)

Papalia, John J.

Because High Cycle Fatigue (HCF) remains the predominant surprise failure mode in gas turbine engines, HCF avoidance design systems are utilized to identify possible failures early in the engine development process. A key requirement of these analyses is accurate determination of the aerodynamic forcing function and corresponding airfoil unsteady response. The current study expands the limited experimental database of blade row interactions necessary for calibration of predictive HCF analyses, with transonic axial-flow compressors of particular interest due to the presence of rotor leading edge shocks. The majority of HCF failures in aircraft engines occur at off-design operating conditions. Therefore, experiments focused on rotor-IGV interactions at off-design are conducted in the Purdue Transonic Research Compressor. The rotor-generated IGV unsteady aerodynamics are quantified when the IGV reset angle causes the vane trailing edge to be nearly aligned with the rotor leading edge shocks. A significant vane response to the impulsive static pressure perturbation associated with a shock is evident in the point measurements at 90% span, with details of this complex interaction revealed in the corresponding time-variant vane-to-vane flow field data. Industry wide implementation of Controlled Diffusion Airfoils (CDA) in modern compressors motivated an investigation of upstream propagating CDA rotor-generated forcing functions. Whole field velocity measurements in the reconfigured Purdue Transonic Research Compressor along the design speedline reveal steady loading had a considerable effect on the rotor shock structure. A detached rotor leading edge shock exists at low loading, with an attached leading edge and mid-chord suction surface normal shock present at nominal loading. These CDA forcing functions are 3--4 times smaller than those generated by the baseline NACA 65 rotor at their respective operating points. However, the IGV unsteady aerodynamic response to the CDA forcing functions remains significant. The intra-vane transport of NACA 65 and CDA rotor wakes is also observed within the time-variant passage velocity data. In general, the wake width and decay rate increase with rotor speed and compressor steady loading respectively.

30 CFR 57.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors rated...

30 CFR 57.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors rated...

49 CFR 192.736 - Compressor stations: Gas detection.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Compressor stations: Gas detection. 192.736... Compressor stations: Gas detection. (a) Not later than September 16, 1996, each compressor building in a compressor station must have a fixed gas detection and alarm system, unless the building is— (1) Constructed...

49 CFR 192.736 - Compressor stations: Gas detection.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Compressor stations: Gas detection. 192.736... Compressor stations: Gas detection. (a) Not later than September 16, 1996, each compressor building in a compressor station must have a fixed gas detection and alarm system, unless the building is— (1) Constructed...

49 CFR 192.736 - Compressor stations: Gas detection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Compressor stations: Gas detection. 192.736... Compressor stations: Gas detection. (a) Not later than September 16, 1996, each compressor building in a compressor station must have a fixed gas detection and alarm system, unless the building is— (1) Constructed...

49 CFR 192.736 - Compressor stations: Gas detection.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Compressor stations: Gas detection. 192.736... Compressor stations: Gas detection. (a) Not later than September 16, 1996, each compressor building in a compressor station must have a fixed gas detection and alarm system, unless the building is— (1) Constructed...

33 CFR 154.826 - Vapor compressors and blowers.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Excessive shaft bearing temperature. (d) If a centrifugal compressor, fan, or lobe blower handles vapor in... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vapor compressors and blowers....826 Vapor compressors and blowers. (a) Each inlet and outlet to a compressor or blower which handles...

Compressor bleed cooling fluid feed system

DOEpatents

Donahoo, Eric E; Ross, Christopher W

2014-11-25

A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.

Increase of Gas-Turbine Plant Efficiency by Optimizing Operation of Compressors

NASA Astrophysics Data System (ADS)

Matveev, V.; Goriachkin, E.; Volkov, A.

2018-01-01

The article presents optimization method for improving of the working process of axial compressors of gas turbine engines. Developed method allows to perform search for the best geometry of compressor blades automatically by using optimization software IOSO and CFD software NUMECA Fine/Turbo. The calculation of the compressor parameters was performed for work and stall point of its performance map on each optimization step. Study was carried out for seven-stage high-pressure compressor and three-stage low-pressure compressors. As a result of optimization, improvement of efficiency was achieved for all investigated compressors.

23. Station Compressor Room 1 with Air Compressors and Accumulator ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. Station Compressor Room 1 with Air Compressors and Accumulator Tanks, view to the south. One of the two large station air compressor units used for depressing the draft tube water level is visible atop a concrete pedestal on the left side of photograph (the second identical compressor is located in an adjacent room). Two of the six station air accumulator tanks are visible in the background. The smaller station service air compressor is visible in right foreground of the photograph was installed in the early 1980s, and replaced the original station service air compressor. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

Control means for a gas turbine engine

NASA Technical Reports Server (NTRS)

Beitler, R. S.; Sellers, F. J.; Bennett, G. W. (Inventor)

1982-01-01

A means is provided for developing a signal representative of the actual compressor casing temperature, a second signal representative of compressor inlet gas temperature, and a third signal representative of compressor speed. Another means is provided for receiving the gas temperature and compressor speed signals and developing a schedule output signal which is a representative of a reference casing temperature at which a predetermined compressor blade stabilized clearance is provided. A means is also provided for comparing the actual compressor casing temperature signal and the reference casing temperature signal and developing a clearance control system representative of the difference. The clearance control signal is coupled to a control valve which controls a flow of air to the compressor casing to control the clearance between the compressor blades and the compressor casing. The clearance control signal can be modified to accommodate transient characteristics. Other embodiments are disclosed.

Stage effects on stalling and recovery of a high-speed 10-stage axial-flow compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Copenhaver, W.W.

1988-01-01

Results of a high-speed 10-stage axial-flow compressor test involving overall compressor and individual stage performance while stalling and operating in quasi-steady rotating stall are described. Test procedures and data-acquisition methods used to obtain the dynamic stalling and quasi-steady in-stall data are explained. Unstalled and in-stall time-averaged data obtained from the compressor operating at five different shaft speeds and one off-schedule variable vane condition are presented. Effects of compressor speed and variable geometry on overall compressor in-stall pressure rise and hysteresis extent are illustrated through the use of quasi-steady-stage temperature rise and pressure-rise characteristics. Results indicate that individual stage performance duringmore » overall compressor rotating stall operation varies considerably throughout the length of the compressor. The measured high-speed 10-stage test compressor individual stage pressure and temperature characteristics were input into a stage-by-stage dynamic compressor performance model. Comparison of the model results and measured pressures provided the additional validation necessary to demonstrate the model's ability to predict high-speed multistage compressor stalling and in-stall performance.« less

Investigation of Performance of Axial-Flow Compressor of XT-46 Turbine-Propeller Engine. II - Performance of Revised Compressor at Design Equivalent Speed. II; Performance of Revised Compressor at Design Equivalent Speed

NASA Technical Reports Server (NTRS)

Creagh, John W. R.

1950-01-01

The compressor from the XT-46 turbine-propeller engine was revised by removing the last two rows of stator blades and by eliminating the interstage leakage paths described in a previous report. With the revised compressor, the flow choking point shifted upstream into the last rotor-blade row but the maximum weight flow was not increased over that of the original compressor. The flow range of the revised compressor was reduced to about two-thirds that obtained with the original compressor. The later stages of the compressor did not produce the design static-pressure increase probably because of excessive boundary-layer build-up in this region. Measurements obtained in the ninth-stage stator showed that the performance up to this station was promising but that the last three stages of the compressor were limiting the useful operating range of the preceding stages. Some modifications in flow-passage geometry and blade settings are believed to be necessary, however, before any major improvements in over-all compressor performance can be obtained.

Natural Gas Imports and Exports. Third Quarter Report 1999

DOE Office of Scientific and Technical Information (OSTI.GOV)

none

1999-10-01

The second quarter 1997 Quarterly Report of Natural Gas Imports and Exports featured a Quarterly Focus report on cross-border natural gas trade between the United States and Mexico. This Quarterly Focus article is a follow-up to the 1997 report. This report revisits and updates the status of some of the pipeline projects discussed in 1997, and examines a number of other planned cross-border pipeline facilities which were proposed subsequent to our 1997 report. A few of the existing and proposed pipelines are bidirectional and thus have the capability of serving either Mexico, or the United States, depending on market conditionsmore » and gas supply availability. These new projects, if completed, would greatly enhance the pipeline infrastructure on the U.S.-Mexico border and would increase gas pipeline throughput capacity for cross-border trade by more than 1 billion cubic feet (Bcf) per day. The Quarterly Focus is comprised of five sections. Section I includes the introduction as well as a brief historic overview of U.S./Mexican natural gas trade; a discussion of Mexico's energy regulatory structure; and a review of trade agreements and a 1992 legislative change which allows for her cross-border gas trade in North America. Section II looks at initiatives that have been taken by the Mexican Government since 1995to open its energy markets to greater competition and privatization. Section III reviews Mexican gas demand forecasts and looks at future opportunities for U.S. gas producers to supplement Mexico's indigenous supplies in order to meet the anticipated rapid growth in demand. Section IV examines the U.S.-Mexico natural gas trade in recent years. It also looks specifically at monthly import and export volumes and prices and identifies short-term trends in this trade. Finally, Section V reviews the existing and planned cross-border gas pipeline infrastructure. The section also specifically describes six planned pipelines intended to expand this pipeline network and their planned in-service dates.« less

Three-dimensional Aerodynamic Instability in Multi-stage Axial Compressors

NASA Technical Reports Server (NTRS)

Suder, Kenneth (Technical Monitor); Tan, Choon-Sooi

2003-01-01

Four separate tasks are reported. The first task: A Computational Model for Short Wavelength Stall Inception and Development In Multi-Stage Compressors; the second task: Three-dimensional Rotating Stall Inception and Effects of Rotating Tip Clearance Asymmetry in Axial Compressors; the third task:Development of an Effective Computational Methodology for Body Force Representation of High-speed Rotor 37; and the fourth task:Development of Circumferential Inlet Distortion through a Representative Eleven Stage High-speed axial compressor. The common theme that threaded throughout these four tasks is the conceptual framework that consists of quantifying flow processes at the fadcompressor blade passage level to define the compressor performance characteristics needed for addressing physical phenomena such compressor aerodynamic instability and compressor response to flow distoriton with length scales larger than compressor blade-to-blade spacing at the system level. The results from these two levels can be synthesized to: (1) simulate compressor aerodynamic instability inception local to a blade rotor tip and its development from a local flow event into the nonlinear limit cycle instability that involves the entire compressor as was demonstrated in the first task; (2) determine the conditions under which compressor stability assessment based on two-dimensional model may not be adequate and the effects of self-induced flow distortion on compressor stability limit as in the second task; (3) quantify multistage compressor response to inlet distortion in stagnation pressure as illustrated in the fourth task; and (4) elucidate its potential applicability for compressor map generation under uniform as well as non-uniform inlet flow given three-dimensional Navier-Stokes solution for each individual blade row as was demonstrated in the third task.

Flow Range of Centrifugal Compressor Being Extended

NASA Technical Reports Server (NTRS)

Skoch, Gary J.

2001-01-01

General Aviation will benefit from turbine engines that are both fuel-efficient and reliable. Current engines fall short of their potential to achieve these attributes. The reason is compressor surge, which is a flow stability problem that develops when the compressor is subjected to conditions that are outside of its operating range. Compressor surge can occur when fuel flow to the engine is increased, temporarily back pressuring the compressor and pushing it past its stability limit, or when the compressor is subjected to inlet flow-field distortions that may occur during takeoff and landing. Compressor surge can result in the loss of an aircraft. As a result, engine designers include a margin of safety between the operating line of the engine and the stability limit line of the compressor. Unfortunately, the most efficient operating line for the compressor is usually closer to its stability limit line than it is to the line that provides an adequate margin of safety. A wider stable flow range will permit operation along the most efficient operating line of the compressor, improving the specific fuel consumption of the engine and reducing emissions. The NASA Glenn Research Center is working to extend the stable flow range of the compressor. Significant extension has been achieved in axial compressors by injecting air upstream of the compressor blade rows. Recently, the technique was successfully applied to a 4:1 pressure ratio centrifugal compressor by injecting streams of air into the diffuser. Both steady and controlled unsteady injection were used to inject air through the diffuser shroud surface and extend the range. Future work will evaluate the effect of air injection through the diffuser hub surface and diffuser vanes with the goal of maximizing the range extension while minimizing the amount of injected air that is required.

14 CFR 25.1103 - Induction system ducts and air duct systems.

Code of Federal Regulations, 2013 CFR

2013-01-01

... between which relative motion could exist must have means for flexibility. (d) For turbine engine and... stage of the engine supercharger and of the auxiliary power unit compressor must have a drain to prevent... compartment to prevent hot gas reverse flow from burning through auxiliary power unit ducts and entering any...

77 FR 26216 - Airworthiness Directives; Rolls-Royce plc Turbofan Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-03

... Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking..., RB211- Trent 892-17, RB211-Trent 892B-17, and RB211-Trent 895-17 turbofan engines. The existing AD...-Trent 895-17 turbofan engines. That AD requires initial and repetitive UIs of certain LP compressor...

77 FR 34380 - CenterPoint Energy Gas Transmission Company, LLC; Notice of Request Under Blanket Authorization

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-11

... injection and since CenterPoint can no longer purchase replacement parts for the existing compressor unit... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-467-000] CenterPoint... May 22, 2012, CenterPoint Energy Gas Transmission Company, LLC (CenterPoint), 1111 Louisiana Street...

78 FR 24190 - Transcontinental Gas Pipe Line Company, LLC; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-24

... Northeast Connector Project (Project) in New York. The Project is an expansion of Transco's existing... Rockaway Delivery Lateral. The Project will include compressor unit modifications and the net addition of... required. In addition to the firm service to be provided by the Project, National Grid NY can use its...

Electron-Beam Switches For A High Peak Power Sled-II Pulse Compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirshfield, Jay, L.

2015-12-02

Omega-P demonstrated triggered electron-beam switches on the L=2 m dual-delay-line X-band pulse compressor at Naval Research Laboratory (NRL). In those experiments, with input pulses of up to 9 MW from the Omega-P/NRL X-band magnicon, output pulses having peak powers of 140-165 MW and durations of 16-20 ns were produced, with record peak power gains M of 18-20. Switch designs are described based on the successful results that should be suitable for use with the existing SLAC SLED-II delay line system, to demonstrate C=9, M=7, and n>>78%, yielding 173ns compressed pulses with peak powers up to 350MW with input of amore » single 50-MW.« less

Power recovery from waste heat in modern turboexpander plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mafi, S.; Drake, C.

1981-01-01

The object of this study is to determine the feasibility and cost of installing a power recovery system in an existing gas processing plant. The power generated by the system is to be used to drive a residue gas compressor, a refrigeration compressor and the heat medium circulating pump, each having its own expander driver. For this purpose the heat from the exhaust of a number of gas turbines is to be combined to provide a total 75 MM Btu/hr. heat energy. Because of safety reasons, Freon 12 has been chosen for the working fluid. The condensing media is watermore » at a design temperature of 80 degrees F. The process conditions for the cycle and the duties of the major equipments are described.« less

30 CFR 285.912 - After I remove a facility, cable, or pipeline, what information must I submit?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false After I remove a facility, cable, or pipeline, what information must I submit? 285.912 Section 285.912 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER...

18 CFR 157.21 - Pre-filing procedures and review process for LNG terminal facilities and other natural gas...

Code of Federal Regulations, 2010 CFR

2010-04-01

... the pre-filing review of any pipeline or other natural gas facilities, including facilities not... from the subject LNG terminal facilities to the existing natural gas pipeline infrastructure. (b) Other... and review process for LNG terminal facilities and other natural gas facilities prior to filing of...

75 FR 77000 - South Coast Conduit/Upper Reach Reliability Project, Santa Barbara County, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-10

... pipeline for improving water supply reliability to Cachuma Project (CP) and State Water Project (SWP... percent of the water supply for communities along the South Coast of Santa Barbara County. Reclamation... demands it is not able to provide the water needed. No redundant supply or pipeline exists to convey CVP...

Closing the Gaps and Filling the STEM Pipeline: A Multidisciplinary Approach

ERIC Educational Resources Information Center

Doerschuk, Peggy; Bahrim, Cristian; Daniel, Jennifer; Kruger, Joseph; Mann, Judith; Martin, Cristopher

2016-01-01

There is a growing demand for degreed science, technology, engineering and mathematics (STEM) professionals, but the production of degreed STEM students is not keeping pace. Problems exist at every juncture along the pipeline. Too few students choose to major in STEM disciplines. Many of those who do major in STEM drop out or change majors.…

Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Cheng-Hsien; Department of Water Resources and Environmental Engineering, Tamkang University, New Taipei City 25137, Taiwan; Low, Ying Min, E-mail: ceelowym@nus.edu.sg

2016-05-15

Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained traction; however, there are still many limitations in these models. For example, several existing two-phase models are confined to one-dimensional problems; in addition, the existing two-dimensional models simulate only the region outside the sand bed. This paper develops a new three-dimensional two-phase model for simulating sediment transport in the sheet flow condition, incorporating recently published rheological characteristics of sediments. The enduring-contact, inertial,more » and fluid viscosity effects are considered in determining sediment pressure and stresses, enabling the model to be applicable to a wide range of particle Reynolds number. A k − ε turbulence model is adopted to compute the Reynolds stresses. In addition, a novel numerical scheme is proposed, thus avoiding numerical instability caused by high sediment concentration and allowing the sediment dynamics to be computed both within and outside the sand bed. The present model is applied to two classical problems, namely, sheet flow and scour under a pipeline with favorable results. For sheet flow, the computed velocity is consistent with measured data reported in the literature. For pipeline scour, the computed scour rate beneath the pipeline agrees with previous experimental observations. However, the present model is unable to capture vortex shedding; consequently, the sediment deposition behind the pipeline is overestimated. Sensitivity analyses reveal that model parameters associated with turbulence have strong influence on the computed results.« less

Thunder Energy Inc. applications to modify an existing sweet gas processing facility to a sour gas processing facility and increase the hydrogen sulfide concentration of existing pipelines, Kelsey area: Examiner report 98-2, application numbers 1007719 and 1013399

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Thunder Energy Inc. received approval from the Alberta Energy and Utilities Board for modification of an existing gas plant to process sour gas, and also applied for permission to increase the hydrogen sulfide content of its existing pipelines in the Kelsey area. This report presents the views of Thunder Energy, the Board, and various intervenors at a hearing held to consider objections to the plant approval and matters related to the application. Issues considered include the need for sour gas processing, the need for the plant modification as opposed to the feasibility of using existing sour gas processing facilities, environmentalmore » impacts, and the requirements for notification of industry in the area. The report concludes with the Board`s decision.« less

Preliminary compressor design study for an advanced multistage axial flow compressor

NASA Technical Reports Server (NTRS)

Marman, H. V.; Marchant, R. D.

1976-01-01

An optimum, axial flow, high pressure ratio compressor for a turbofan engine was defined for commercial subsonic transport service starting in the late 1980's. Projected 1985 technologies were used and applied to compressors with an 18:1 pressure ratio having 6 to 12 stages. A matrix of 49 compressors was developed by statistical techniques. The compressors were evaluated by means of computer programs in terms of various airline economic figures of merit such as return on investment and direct-operating cost. The optimum configuration was determined to be a high speed, 8-stage compressor with an average blading aspect ratio of 1.15.

Design of a CO2 Twin Rotary Compressor for a Heat Pump Water Heater

NASA Astrophysics Data System (ADS)

Ahn, Jong Min; Kim, Woo Young; Kim, Hyun Jin; Cho, Sung Oug; Seo, Jong Cheun

2010-06-01

For a CO2 heat pump water heater, one-stage twin rotary compressor has been designed. As a design tool, computer simulation program for the compressor performance has been made. Validation of the simulation program has been carried out for a bench model compressor in a compressor calorimeter. Cooling capacity and the compressor input power were reasonably well compared between the simulation and the calorimeter test. Good agreement on P-V diagram between the simulation and the test was also obtained. With this validated compressor simulation program, parametric study has been performed to arrive at optimum dimensions for the compression chamber.

An Approach to Detect and Mitigate Ice Particle Accretion in Aircraft Engine Compression Systems

NASA Technical Reports Server (NTRS)

May, Ryan D.; Guo, Ten-Huei; Simon, Donald L.

2013-01-01

The accretion of ice in the compression system of commercial gas turbine engines operating in high ice water content conditions is a safety issue being studied by the aviation sector. While most of the research focuses on the underlying physics of ice accretion and the meteorological conditions in which accretion can occur, a systems-level perspective on the topic lends itself to potential near-term operational improvements. This work focuses on developing an accurate and reliable algorithm for detecting the accretion of ice in the low pressure compressor of a generic 40,000 lbf thrust class engine. The algorithm uses only the two shaft speed sensors and works regardless of engine age, operating condition, and power level. In a 10,000-case Monte Carlo simulation, the detection approach was found to have excellent capability at determining ice accretion from sensor noise with detection occurring when ice blocks an average of 6.8 percent of the low pressure compressor area. Finally, an initial study highlights a potential mitigation strategy that uses the existing engine actuators to raise the temperature in the low pressure compressor in an effort to reduce the rate at which ice accretes.

An Approach to Detect and Mitigate Ice Particle Accretion in Aircraft Engine Compression Systems

NASA Technical Reports Server (NTRS)

May, Ryan D.; Guo, Ten-Huei; Simon, Donald L.

2013-01-01

The accretion of ice in the compression system of commercial gas turbine engines operating in high ice water content conditions is a safety issue being studied by the aviation sector. While most of the research focuses on the underlying physics of ice accretion and the meteorological conditions in which accretion can occur, a systems-level perspective on the topic lends itself to potential near-term operational improvements. This work focuses on developing an accurate and reliable algorithm for detecting the accretion of ice in the low pressure compressor of a generic 40,000 lbf thrust class engine. The algorithm uses only the two shaft speed sensors and works regardless of engine age, operating condition, and power level. In a 10,000-case Monte Carlo simulation, the detection approach was found to have excellent capability at determining ice accretion from sensor noise with detection occurring when ice blocks an average of 6.8% of the low pressure compressor area. Finally, an initial study highlights a potential mitigation strategy that uses the existing engine actuators to raise the temperature in the low pressure compressor in an effort to reduce the rate at which ice accretes.

A Systems-Level Perspective on Engine Ice Accretion

NASA Technical Reports Server (NTRS)

May, Ryan D.; Guo, Ten-Huei; Simon, Donald L.

2013-01-01

The accretion of ice in the compression system of commercial gas turbine engines operating in high ice water content conditions is a safety issue being studied by the aviation sector. While most of the research focuses on the underlying physics of ice accretion and the meteorological conditions in which accretion can occur, a systems-level perspective on the topic lends itself to potential near-term operational improvements. This work focuses on developing an accurate and reliable algorithm for detecting the accretion of ice in the low pressure compressor of a generic 40,000 lbf thrust class engine. The algorithm uses only the two shaft speed sensors and works regardless of engine age, operating condition, and power level. In a 10,000-case Monte Carlo simulation, the detection approach was found to have excellent capability at determining ice accretion from sensor noise with detection occurring when ice blocks an average of 6.8% of the low pressure compressor area. Finally, an initial study highlights a potential mitigation strategy that uses the existing engine actuators to raise the temperature in the low pressure compressor in an effort to reduce the rate at which ice accretes.

Flow and Performance Calculations of Axial Compressor near Stall Margin

NASA Astrophysics Data System (ADS)

Hwang, Yoojun; Kang, Shin-Hyoung

2010-06-01

Three-dimensional flows through a Low Speed Research Axial Compressor were numerically conducted in order to estimate the performance through unsteady and steady-state simulations. The first stage with the inlet guide vane was investigated at the design point to confirm that the rotor blade induced periodicity exists. Special attention was paid to the flow near the stall condition to inspect the flow behavior in the vicinity of the stall margin. The performance predicted under the steady-state assumption is in good agreement with the measured data. However, the steady-state calculations induce more blockage through the blade passage. Flow separations on the blade surface and end-walls are reduced when unsteady simulation is conducted. The negative jet due to the wake of the rotor blade periodically distorts the boundary layer on the surface of the stator blade and improves the performance of the compressor in terms of the pressure rise. The advantage of the unsteadiness increases as the flow rate reduces. In addition, the rotor tip leakage flow is forced downstream by the unsteadiness. Consequently, the behavior contributes to extending the range of operation by preventing the leakage flow from proceeding upstream near the stall margin.

A Bunch Compression Method for Free Electron Lasers that Avoids Parasitic Compressions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, Stephen V.; Douglas, David R.; Tennant, Christopher D.

2015-09-01

Virtually all existing high energy (>few MeV) linac-driven FELs compress the electron bunch length though the use of off-crest acceleration on the rising side of the RF waveform followed by transport through a magnetic chicane. This approach has at least three flaws: 1) it is difficult to correct aberrations--particularly RF curvature, 2) rising side acceleration exacerbates space charge-induced distortion of the longitudinal phase space, and 3) all achromatic "negative compaction" compressors create parasitic compression during the final compression process, increasing the CSR-induced emittance growth. One can avoid these deficiencies by using acceleration on the falling side of the RF waveformmore » and a compressor with M 56>0. This approach offers multiple advantages: 1) It is readily achieved in beam lines supporting simple schemes for aberration compensation, 2) Longitudinal space charge (LSC)-induced phase space distortion tends, on the falling side of the RF waveform, to enhance the chirp, and 3) Compressors with M 56>0 can be configured to avoid spurious over-compression. We will discuss this bunch compression scheme in detail and give results of a successful beam test in April 2012 using the JLab UV Demo FEL« less

The design of a small linear-resonant, split Stirling cryogenic refrigerator compressor

NASA Technical Reports Server (NTRS)

Ackermann, R. A.

1985-01-01

The development of a small linear-resonant compressor for use in a 1/4-watt, 78K, split Stirling cryogenic refrigerator is discussed. The compressor contains the following special features: (1) a permanent-magnet linear motor; (2) resonant dynamics; (3) dynamic balancing; and (4) a close-clearance seal between the compressor piston and cylinder. This paper describes the design of the compressor, and presents component test data and system test data for the compressor driving a 1/4-watt expander.

Centrifugal compressor modifications and their effect on high-frequency pipe wall vibration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Motriuk, R.W.; Harvey, D.P.

1998-08-01

High-frequency pulsation generated by centrifugal compressors, with pressure wave-lengths much smaller than the attached pipe diameter, can cause fatigue failures of the compressor internals, impair compressor performance, and damage the attached compressor piping. There are numerous sources producing pulsation in centrifugal compressors. Some of them are discussed in literature at large (Japikse, 1995; Niese, 1976). NGTL has experienced extreme high-frequency discharge pulsation and pipe wall vibration on many of its radial inlet high-flow centrifugal gas compressor facilities. These pulsations led to several piping attachment failures and compressor internal component failures while the compressor operated within the design envelope. This papermore » considers several pulsation conditions at an NGTL compression facility which resulted in unacceptable piping vibration. Significant vibration attenuation was achieved by modifying the compressor (pulsation source) through removal of the diffuser vanes and partial removal of the inlet guide vanes (IGV). Direct comparison of the changes in vibration, pulsation, and performance are made for each of the modifications. The vibration problem, probable causes, options available to address the problem, and the results of implementation are reviewed. The effects of diffuser vane removal on discharge pipe wall vibration as well as changes in compressor performance are described.« less

Performance Investigations of a Large Centrifugal Compressor from an Experimental Turbojet Engine

NASA Technical Reports Server (NTRS)

Ginsburg, Ambrose; Creagh, John W. R.; Ritter, William K.

1948-01-01

An investigation was conducted on a large centrifugal compressor from an experimental turbojet engine to determine the performance of the compressor and to obtain fundamental information on the aerodynamic problems associated with large centrifugal-type compressors. The results of the research conducted on the compressor indicated that the compressor would not meet the desired engine-design air-flow requirements (78 lb/sec) because of an air-flow restriction in the vaned collector (diffuser). Revision of the vaned collector resulted in an increased air-flow capacity over the speed range and showed improved matching of the impeller and diffuser components. At maximum flow, the original compressor utilized approximately 90 percent of the available geometric throat area at the vaned-collector inlet and the revised compressor utilized approximately 94 percent, regardless of impeller speed. The ratio of the maximum weight flows of the revised and original compressors were less than the ratio of effective critical throat areas of the two compressors because of the large pressure losses in the impeller near the impeller inelt and the difference increased with an increase in impeller speed. In order to further increase the pressure ratio and maximum weight flow of the compressor, the impeller must be modified to eliminate the pressure losses therein.

A real-time coherent dedispersion pipeline for the giant metrewave radio telescope

NASA Astrophysics Data System (ADS)

De, Kishalay; Gupta, Yashwant

2016-02-01

A fully real-time coherent dedispersion system has been developed for the pulsar back-end at the Giant Metrewave Radio Telescope (GMRT). The dedispersion pipeline uses the single phased array voltage beam produced by the existing GMRT software back-end (GSB) to produce coherently dedispersed intensity output in real time, for the currently operational bandwidths of 16 MHz and 32 MHz. Provision has also been made to coherently dedisperse voltage beam data from observations recorded on disk. We discuss the design and implementation of the real-time coherent dedispersion system, describing the steps carried out to optimise the performance of the pipeline. Presently functioning on an Intel Xeon X5550 CPU equipped with a NVIDIA Tesla C2075 GPU, the pipeline allows dispersion free, high time resolution data to be obtained in real-time. We illustrate the significant improvements over the existing incoherent dedispersion system at the GMRT, and present some preliminary results obtained from studies of pulsars using this system, demonstrating its potential as a useful tool for low frequency pulsar observations. We describe the salient features of our implementation, comparing it with other recently developed real-time coherent dedispersion systems. This implementation of a real-time coherent dedispersion pipeline for a large, low frequency array instrument like the GMRT, will enable long-term observing programs using coherent dedispersion to be carried out routinely at the observatory. We also outline the possible improvements for such a pipeline, including prospects for the upgraded GMRT which will have bandwidths about ten times larger than at present.

Experimental Studies on a Single Stage Stirling Type Pulse Tube Cryocooler Driven by Oil-Lubricated Compressor

NASA Astrophysics Data System (ADS)

Jia, Ren; Jianying, Hu; Ercang, Luo; Xiaotao, Wang

2010-04-01

Because lubricating oil for moving parts is not allowed to go into the pulse tube cryocooler, Stirling type pulse tube cryocoolers are generally driven by oil-free compressors although oil-lubricated compressors are much cheaper and facile. Recently, it was proposed that an acoustic transparent and oil blocking diaphragm could be employed to separate the compressor and the cryocooler. Thus, the cryocooler can be driven by oil-lubricated compressors. In this paper, a pulse tube cryocooler is designed to match a crankcase compressor. Although the efficiency of the crankcase compressor is lower compared with the oil-free linear compressor, the crankcase compressor can easily work at lower frequency which results in higher efficiency for the cryocooler. So the relative high performance of the whole system can be maintained. In this system, the cryocooler delivers 28.5 W of cooling at 80 K with 680 W of electrical input power and operates at 15 Hz. The corresponding Carnot efficiency is 11.52%.

Performance of Compressor of XJ-41-V Turbojet Engine. 4; Performance Analysis Over Range of Compressor Speeds from 5000 to 10,000 RPM

NASA Technical Reports Server (NTRS)

Creagh, John W. R.; Ginsburg, Ambrose

1948-01-01

An investigation of the XJ-41-V turbojet-engine compressor was conducted to determine the performance of the compressor and to obtain fundamental information on the aerodynamic problems associated with large centrifugal-type compressors. The results of the research conducted on the original compressor indicated the compressor would not meet the desired engine-design air-flow requirements because of an air-flow restriction in the vaned collector. The compressor air-flow choking point occurred near the entrance to the vaned-collector passage and was instigated by a poor mass-flow distribution at the vane entrance and from relatively large negative angles of attack of the air stream along the entrance edges of the vanes at the outer passage wall and large positive angles of attack at the inner passage wall. As a result of the analysis, a design change of the vaned collector entrance is recommended for improving the maximum flow capacity of the compressor.

Consideration of Sludge Formation in HFC-134a / Polyol Ester oil Refrigeration System

NASA Astrophysics Data System (ADS)

Yamamoto, Tsutomu; Yamamoto, Tethuya; Simizu, Yasuhiko; Nakayama, Yoshinori; Takizawa, Kikuo

A refrigeration test employing HFC-134a and polyol ester oil was carried out in order to make clear the causes of the sludge formation in the capillary tube. Compressors used were two types: a hermetic reciprocating compressor and a rotary compressor. Installed dryer contained desiccant of the compound zeolite type. The results showed that the amount of capillary sludge increased as the compressor temperature rose. The capillary sludge was determined to consist of desiccant and metal dust for the reciprocating compressor, and of tar-like substance for the rotary compressor. Thermal stability test which was used to check the degree of deterioration of the ester oil, suggested that the presence of desiccant and high compressor temperature might produce tar-like substance by the break down and polymerization of the ester oil. In addition, it was confirmed that factors affecting the sludge formation were the dirtiness of the refrigeration circuit for the reciprocating compressor, and the presence of desiccant, for the rotary compressor.

Comprehensive model of a hermetic reciprocating compressor

NASA Astrophysics Data System (ADS)

Yang, B.; Ziviani, D.; Groll, E. A.

2017-08-01

A comprehensive simulation model is presented to predict the performance of a hermetic reciprocating compressor and to reveal the underlying mechanisms when the compressor is running. The presented model is composed of sub-models simulating the in-cylinder compression process, piston ring/journal bearing frictional power loss, single phase induction motor and the overall compressor energy balance among different compressor components. The valve model, leakage through piston ring model and in-cylinder heat transfer model are also incorporated into the in-cylinder compression process model. A numerical algorithm solving the model is introduced. The predicted results of the compressor mass flow rate and input power consumption are compared to the published compressor map values. Future work will focus on detailed experimental validation of the model and parametric studies investigating the effects of structural parameters, including the stroke-to-bore ratio, on the compressor performance.

Effect of a curved duct upstream on performance of small centrifugal compressors for automobile turbochargers

NASA Astrophysics Data System (ADS)

Kikuchi, Shigeta; Yamasaki, Nobuhiko; Yamagata, Akihiro

2013-02-01

Since the automobile turbochargers are installed in an engine compartment with limited space, the ducts upstream of the turbocharger compressor may be curved in a complex manner. In the present paper, the effect of a curved duct upstream on performance of small centrifugal compressors for automobile turbochargers is discussed. The computational fluid dynamics (CFD) analysis of a turbocharger compressor validated for the compressor model with the straight pipe applied to the compressor with the curved pipe are executed, and the deterioration of the performance for the curved pipe is confirmed. It is also found that the deterioration of compressor performance is caused by the interaction of the secondary flow and the impeller.

Three-stage sorption type cryogenic refrigeration systems and methods employing heat regeneration

NASA Technical Reports Server (NTRS)

Bard, Steven (Inventor); Jones, Jack A. (Inventor)

1992-01-01

A three-stage sorption type cryogenic refrigeration system, each stage containing a fluid having a respectively different boiling point, is presented. Each stage includes a compressor in which a respective fluid is heated to be placed in a high pressure gaseous state. The compressor for that fluid which is heated to the highest temperature is enclosed by the other two compressors to permit heat to be transferred from the inner compressor to the surrounding compressors. The system may include two sets of compressors, each having the structure described above, with the interior compressors of the two sets coupled together to permit selective heat transfer therebetween, resulting in more efficient utilization of input power.

Temperature Swing Adsorption Compressor Development

NASA Technical Reports Server (NTRS)

Finn, John E.; Mulloth, Lila M.; Affleck, Dave L.

2001-01-01

Closing the oxygen loop in an air revitalization system based on four-bed molecular sieve and Sabatier reactor technology requires a vacuum pump-compressor that can take the low-pressure CO, from the 4BMS and compress and store for use by a Sabatier reactor. NASA Ames Research Center proposed a solid-state temperature-swing adsorption (TSA) compressor that appears to meet performance requirements, be quiet and reliable, and consume less power than a comparable mechanical compressor/accumulator combination. Under this task, TSA compressor technology is being advanced through development of a complete prototype system. A liquid-cooled TSA compressor has been partially tested, and the rest of the system is being fabricated. An air-cooled TSA compressor is also being designed.

Water injected fuel cell system compressor

DOEpatents

Siepierski, James S.; Moore, Barbara S.; Hoch, Martin Monroe

2001-01-01

A fuel cell system including a dry compressor for pressurizing air supplied to the cathode side of the fuel cell. An injector sprays a controlled amount of water on to the compressor's rotor(s) to improve the energy efficiency of the compressor. The amount of water sprayed out the rotor(s) is controlled relative to the mass flow rate of air inputted to the compressor.

Compressor Performance Scaling in the Presence of Non-Uniform Flow

NASA Astrophysics Data System (ADS)

Hill, David Jarrod

Fuselage-embedded engines in future aircraft will see increased flow distortions due to the ingestion of airframe boundary layers. This reduces the required propulsive power compared to podded engines. Inlet flow distortions mean that localized regions of flow within the fan and first stage compressor are operating at off-design conditions. It is important to weigh the benefit of increased vehicle propulsive efficiency against the resultant reduction in engine efficiency. High computational cost has limited most past research to single distortion studies. The objective of this thesis is to extract scaling laws for transonic compressor performance in the presence of various distortion patterns and intensities. The machine studied is the NASA R67 transonic compressor. Volumetric source terms are used to model rotor and stator blade rows. The modelling approach is an innovative combination of existing flow turning and loss models, combined with a compressible flow correction. This approach allows for a steady calculation to capture distortion transfer; as a result, the computational cost is reduced by two orders of magnitude. At peak efficiency, the rotor work coefficient and isentropic efficiency are matched within 1.4% of previously published experimental results. A key finding of this thesis is that, in non-uniform flow, the state-of-the-art loss model employed is unable to capture the impact of variations in local flow coefficient, limiting the analysis of local entropy generation. New insight explains the mechanism governing the interaction between a total temperature distortion and a compressor rotor. A parametric study comprising 16 inlet distortions reveals that for total temperature distortions, upstream flow redistribution and rotor diffusion factor changes are shown to scale linearly with distortion severity. Linear diffusion factor scaling does not hold true for total pressure distortions. For combined total temperature and total pressure distortions, the changes in rotor diffusion factor are predicted by the summation of the individual distortions, within 3.65%.

2012 Ground Testing Highlights

NASA Technical Reports Server (NTRS)

Buchholz, Steven J.

2012-01-01

As part of the Fundamental Aeronautics Program and a collaborative effort with Boeing, and Lockheed Martin this past year a series of sonic boom test were completed in the NASA Ames Unitary Plan Wind Tunnel (UPWT). One of the goals was to develop new test techniques and hardware for measuring sonic boom signatures in the transonic and supersonic regimes. Data for various model designs and configurations were collected and will be used to validate CFD predictions of sonic boom signatures. Reactivation of the NASA Ames Mitsubishi compressor system was completed this past year. The compressor is intended to replace and augment the existing UPWT Clark Compressor as the primary Make Up Air (MUA) source. The MUA system provides air and vacuum pumping capability to the Ames UPWT. It will improve productivity and reliability of the UPWT as a vital testing and research facility for the U.S. aerospace industry and NASA. Funding for this task was provided from the American Recovery Investment Act (ARRA). Installation and validation of a Noncontact Stress Monitoring System (NSMS) for the 3-stage compressor was completed at the 11-foot Transonic Wind Tunnel. The system, originally developed at AEDC, consists of 36 pairs of LED light sources with optic beam send and receive probes along a 1-per rev signal. The new system allows for continuous monitoring and recording of compressor blade bending and torsion stress during normal test operations. A very unusual test was completed in the 11 FT TWT to acquire aerodynamic and flow field data for the Crew Exploration Vehicle (CEV) Parachute Assembly System (CPAS) to validate CFD methods and tools. Surface pressure distribution measurements and velocity measurements in the wake of the command module back to the drogues parachute location were acquired. Testing methods included Particle Image Velocimetry (PIV), Pressure Sensitive Paint (PSP), Schlieren Infrared Imaging (IR) and boundary layer survey and skin friction.

78 FR 62012 - Transcontinental Gas Pipeline Company; Notice of Availability of the Draft Environmental Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-11

... 647 thousand dekatherms per day (Mdth/d) of natural gas to National Grid's distribution system in New... incremental natural gas supply to National Grid, as part of the 647 Mdth/d to be provided by the Rockaway...: Approximately 3.2 miles of new 26-inch-diameter pipeline to deliver natural gas from Transco's existing Lower...

Reframing the School-to-Prison Pipeline: The Experiences of Latina/o Youth and Families

ERIC Educational Resources Information Center

Pantoja, Alicia

2013-01-01

In this paper, I argue that school-to-prison pipeline (SPP) research on Latina/os shows the existence of an interconnected system of policies and social practices, in and out of schools, punitive and non-punitive in nature, which together work to criminalize Latina/o students and their families. This intersection (Crenshaw, 1991) and multiplicity…

Data Reduction of Jittered Infrared Images Using the ORAC Pipeline

NASA Astrophysics Data System (ADS)

Currie, Malcolm; Wright, Gillian; Bridger, Alan; Economou, Frossie

We relate our experiences using the ORAC data reduction pipeline for jittered images of stars and galaxies. The reduction recipes currently combine applications from several Starlink packages with intelligent Perl recipes to cater to UKIRT data. We describe the recipes and some of the algorithms used, and compare the quality of the resultant mosaics and photometry with the existing facilities.

Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system

NASA Astrophysics Data System (ADS)

Azizi, Mohammad Ali; Brouwer, Jacob

2017-10-01

A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design. The multi-stage radial design of the compressor enhances the ability of the compressor to maintain air flow rate during transient step-load changes. These transient step-load changes are exhibited in many potential applications for SOFC/GT systems. The compressor provides sustained air flow rate during the mild stall/surge event that occurs due to the transient step-load change that is applied, indicating that this type of compressor is well-suited for this hybrid application.

The application of Mike Urban model in drainage and waterlogging in Lincheng county, China

NASA Astrophysics Data System (ADS)

Luan, Qinghua; Zhang, Kun; Liu, Jiahong; Wang, Dong; Ma, Jun

2018-06-01

Recently, the water disaster in cities especially in Chinese mountainous cities is more serious, due to the coupling influences of waterlogging and regional floods. It is necessary to study the surface runoff process of mountainous cities and examine the regional drainage pipeline network. In this study, the runoff processes of Lincheng county (located in Hebei province, China) in different scenarios were simulated through Mike Urban model. The results show that all of the runoff process of the old town and the new residential area with larger slope, is significant and full flow of these above zones exists in the part of the drainage pipeline network; and the overflow exists in part of the drainage pipeline network when the return period is ten years or twenty years, which illuminates that the waterlogging risk in this zone of Lincheng is higher. Therefore, remodeling drainage pipeline network in the old town of Lincheng and adding water storage ponds in the new residential areas were suggested. This research provides both technical support and decision-making reference to local storm flood management, also give the experiences for the study on the runoff process of similar cities.

Development of an optical character recognition pipeline for handwritten form fields from an electronic health record.

PubMed

Rasmussen, Luke V; Peissig, Peggy L; McCarty, Catherine A; Starren, Justin

2012-06-01

Although the penetration of electronic health records is increasing rapidly, much of the historical medical record is only available in handwritten notes and forms, which require labor-intensive, human chart abstraction for some clinical research. The few previous studies on automated extraction of data from these handwritten notes have focused on monolithic, custom-developed recognition systems or third-party systems that require proprietary forms. We present an optical character recognition processing pipeline, which leverages the capabilities of existing third-party optical character recognition engines, and provides the flexibility offered by a modular custom-developed system. The system was configured and run on a selected set of form fields extracted from a corpus of handwritten ophthalmology forms. The processing pipeline allowed multiple configurations to be run, with the optimal configuration consisting of the Nuance and LEADTOOLS engines running in parallel with a positive predictive value of 94.6% and a sensitivity of 13.5%. While limitations exist, preliminary experience from this project yielded insights on the generalizability and applicability of integrating multiple, inexpensive general-purpose third-party optical character recognition engines in a modular pipeline.

Development of an optical character recognition pipeline for handwritten form fields from an electronic health record

PubMed Central

Peissig, Peggy L; McCarty, Catherine A; Starren, Justin

2011-01-01

Background Although the penetration of electronic health records is increasing rapidly, much of the historical medical record is only available in handwritten notes and forms, which require labor-intensive, human chart abstraction for some clinical research. The few previous studies on automated extraction of data from these handwritten notes have focused on monolithic, custom-developed recognition systems or third-party systems that require proprietary forms. Methods We present an optical character recognition processing pipeline, which leverages the capabilities of existing third-party optical character recognition engines, and provides the flexibility offered by a modular custom-developed system. The system was configured and run on a selected set of form fields extracted from a corpus of handwritten ophthalmology forms. Observations The processing pipeline allowed multiple configurations to be run, with the optimal configuration consisting of the Nuance and LEADTOOLS engines running in parallel with a positive predictive value of 94.6% and a sensitivity of 13.5%. Discussion While limitations exist, preliminary experience from this project yielded insights on the generalizability and applicability of integrating multiple, inexpensive general-purpose third-party optical character recognition engines in a modular pipeline. PMID:21890871

CLAMP - a toolkit for efficiently building customized clinical natural language processing pipelines.

PubMed

Soysal, Ergin; Wang, Jingqi; Jiang, Min; Wu, Yonghui; Pakhomov, Serguei; Liu, Hongfang; Xu, Hua

2017-11-24

Existing general clinical natural language processing (NLP) systems such as MetaMap and Clinical Text Analysis and Knowledge Extraction System have been successfully applied to information extraction from clinical text. However, end users often have to customize existing systems for their individual tasks, which can require substantial NLP skills. Here we present CLAMP (Clinical Language Annotation, Modeling, and Processing), a newly developed clinical NLP toolkit that provides not only state-of-the-art NLP components, but also a user-friendly graphic user interface that can help users quickly build customized NLP pipelines for their individual applications. Our evaluation shows that the CLAMP default pipeline achieved good performance on named entity recognition and concept encoding. We also demonstrate the efficiency of the CLAMP graphic user interface in building customized, high-performance NLP pipelines with 2 use cases, extracting smoking status and lab test values. CLAMP is publicly available for research use, and we believe it is a unique asset for the clinical NLP community. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

MetaStorm: A Public Resource for Customizable Metagenomics Annotation

PubMed Central

Arango-Argoty, Gustavo; Singh, Gargi; Heath, Lenwood S.; Pruden, Amy; Xiao, Weidong; Zhang, Liqing

2016-01-01

Metagenomics is a trending research area, calling for the need to analyze large quantities of data generated from next generation DNA sequencing technologies. The need to store, retrieve, analyze, share, and visualize such data challenges current online computational systems. Interpretation and annotation of specific information is especially a challenge for metagenomic data sets derived from environmental samples, because current annotation systems only offer broad classification of microbial diversity and function. Moreover, existing resources are not configured to readily address common questions relevant to environmental systems. Here we developed a new online user-friendly metagenomic analysis server called MetaStorm (http://bench.cs.vt.edu/MetaStorm/), which facilitates customization of computational analysis for metagenomic data sets. Users can upload their own reference databases to tailor the metagenomics annotation to focus on various taxonomic and functional gene markers of interest. MetaStorm offers two major analysis pipelines: an assembly-based annotation pipeline and the standard read annotation pipeline used by existing web servers. These pipelines can be selected individually or together. Overall, MetaStorm provides enhanced interactive visualization to allow researchers to explore and manipulate taxonomy and functional annotation at various levels of resolution. PMID:27632579

MetaStorm: A Public Resource for Customizable Metagenomics Annotation.

PubMed

Arango-Argoty, Gustavo; Singh, Gargi; Heath, Lenwood S; Pruden, Amy; Xiao, Weidong; Zhang, Liqing

2016-01-01

Metagenomics is a trending research area, calling for the need to analyze large quantities of data generated from next generation DNA sequencing technologies. The need to store, retrieve, analyze, share, and visualize such data challenges current online computational systems. Interpretation and annotation of specific information is especially a challenge for metagenomic data sets derived from environmental samples, because current annotation systems only offer broad classification of microbial diversity and function. Moreover, existing resources are not configured to readily address common questions relevant to environmental systems. Here we developed a new online user-friendly metagenomic analysis server called MetaStorm (http://bench.cs.vt.edu/MetaStorm/), which facilitates customization of computational analysis for metagenomic data sets. Users can upload their own reference databases to tailor the metagenomics annotation to focus on various taxonomic and functional gene markers of interest. MetaStorm offers two major analysis pipelines: an assembly-based annotation pipeline and the standard read annotation pipeline used by existing web servers. These pipelines can be selected individually or together. Overall, MetaStorm provides enhanced interactive visualization to allow researchers to explore and manipulate taxonomy and functional annotation at various levels of resolution.

Dimension Determination of Precursive Stall Events in a Single Stage High Speed Compressor

NASA Technical Reports Server (NTRS)

Bright, Michelle M.; Qammar, Helen K.; Hartley, Tom T.

1996-01-01

This paper presents a study of the dynamics for a single-stage, axial-flow, high speed compressor core, specifically, the NASA Lewis rotor stage 37. Due to the overall blading design for this advanced core compressor, each stage has considerable tip loading and higher speed than most compressor designs, thus, the compressor operates closer to the stall margin. The onset of rotating stall is explained as bifurcations in the dynamics of axial compressors. Data taken from the compressor during a rotating stall event is analyzed. Through the use of a box-assisted correlation dimension methodology, the attractor dimension is determined during the bifurcations leading to rotating stall. The intent of this study is to examine the behavior of precursive stall events so as to predict the entrance into rotating stall. This information may provide a better means to identify, avoid or control the undesirable event of rotating stall formation in high speed compressor cores.

A modeling study of a centrifugal compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popovic, P.; Shapiro, H.N.

1998-12-31

A centrifugal compressor, which is part of a chlorofluorocarbon R-114 chiller installation, was investigated, operating with a new refrigerant, hydrofluorocarbon R-236ea, a proposed alternative to R-114. A large set of R-236ea operating data, as well as a limited amount of R-114 data, were available for this study. A relatively simple analytical compressor model was developed to describe compressor performance. The model was built upon a thorough literature search, experimental data, and some compressor design parameters. Two original empirical relations were developed, providing a new approach to the compressor modeling. The model was developed in a format that would permit itmore » to be easily incorporated into a complete chiller simulation. The model was found to improve somewhat on the quantitative and physical aspects of a compressor model of the same format found in the literature. It was found that the compressor model is specific to the particular refrigerant.« less

Fault detection and diagnosis for refrigerator from compressor sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keres, Stephen L.; Gomes, Alberto Regio; Litch, Andrew D.

A refrigerator, a sealed refrigerant system, and method are provided where the refrigerator includes at least a refrigerated compartment and a sealed refrigerant system including an evaporator, a compressor, a condenser, a controller, an evaporator fan, and a condenser fan. The method includes monitoring a frequency of the compressor, and identifying a fault condition in the at least one component of the refrigerant sealed system in response to the compressor frequency. The method may further comprise calculating a compressor frequency rate based upon the rate of change of the compressor frequency, wherein a fault in the condenser fan is identifiedmore » if the compressor frequency rate is positive and exceeds a condenser fan fault threshold rate, and wherein a fault in the evaporator fan is identified if the compressor frequency rate is negative and exceeds an evaporator fan fault threshold rate.« less

Impact of the electric compressor for automotive air conditioning system on fuel consumption and performance analysis

NASA Astrophysics Data System (ADS)

Zulkifli, A. A.; Dahlan, A. A.; Zulkifli, A. H.; Nasution, H.; Aziz, A. A.; Perang, M. R. M.; Jamil, H. M.; Misseri, M. N.

2015-12-01

Air conditioning system is the biggest auxiliary load in a vehicle where the compressor consumed the largest. Problem with conventional compressor is the cooling capacity cannot be control directly to fulfill the demand of thermal load inside vehicle cabin. This study is conducted experimentally to analyze the difference of fuel usage and air conditioning performance between conventional compressor and electric compressor of the air conditioning system in automobile. The electric compressor is powered by the car battery in non-electric vehicle which the alternator will recharge the battery. The car is setup on a roller dynamometer and the vehicle speed is varied at 0, 30, 60, 90 and 110 km/h at cabin temperature of 25°C and internal heat load of 100 and 400 Watt. The results shows electric compressor has better fuel consumption and coefficient of performance compared to the conventional compressor.

Core compressor exit stage study. 1: Aerodynamic and mechanical design

NASA Technical Reports Server (NTRS)

Burdsall, E. A.; Canal, E., Jr.; Lyons, K. A.

1979-01-01

The effect of aspect ratio on the performance of core compressor exit stages was demonstrated using two three stage, highly loaded, core compressors. Aspect ratio was identified as having a strong influence on compressors endwall loss. Both compressors simulated the last three stages of an advanced eight stage core compressor and were designed with the same 0.915 hub/tip ratio, 4.30 kg/sec (9.47 1bm/sec) inlet corrected flow, and 167 m/sec (547 ft/sec) corrected mean wheel speed. The first compressor had an aspect ratio of 0.81 and an overall pressure ratio of 1.357 at a design adiabatic efficiency of 88.3% with an average diffusion factor or 0.529. The aspect ratio of the second compressor was 1.22 with an overall pressure ratio of 1.324 at a design adiabatic efficiency of 88.7% with an average diffusion factor of 0.491.

Leak detection by mass balance effective for Norman Wells line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liou, J.C.P.

Mass-balance calculations for leak detection have been shown as effective as a leading software system, in a comparison based on a major Canadian crude-oil pipeline. The calculations and NovaCorp`s Leakstop software each detected 4% (approximately) or greater leaks on Interprovincial Pipe Line (IPL) Inc.`s Norman Wells pipeline. Insufficient data exist to assess performances of the two methods for leaks smaller than 4%. Pipeline leak detection using such software-based systems are common. Their effectiveness is measured by how small and how quickly a leak can be detected. Algorithms used and measurement uncertainties determine leak detectability.

High pressure air compressor valve fault diagnosis using feedforward neural networks

NASA Astrophysics Data System (ADS)

James Li, C.; Yu, Xueli

1995-09-01

Feedforward neural networks (FNNs) are developed and implemented to classify a four-stage high pressure air compressor into one of the following conditions: baseline, suction or exhaust valve faults. These FNNs are used for the compressor's automatic condition monitoring and fault diagnosis. Measurements of 39 variables are obtained under different baseline conditions and third-stage suction and exhaust valve faults. These variables include pressures and temperatures at all stages, voltage between phase aand phase b, voltage between phase band phase c, total three-phase real power, cooling water flow rate, etc. To reduce the number of variables, the amount of their discriminatory information is quantified by scattering matrices to identify statistical significant ones. Measurements of the selected variables are then used by a fully automatic structural and weight learning algorithm to construct three-layer FNNs to classify the compressor's condition. This learning algorithm requires neither guesses of initial weight values nor number of neurons in the hidden layer of an FNN. It takes an incremental approach in which a hidden neuron is trained by exemplars and then augmented to the existing network. These exemplars are then made orthogonal to the newly identified hidden neuron. They are subsequently used for the training of the next hidden neuron. The betterment continues until a desired accuracy is reached. After the neural networks are established, novel measurements from various conditions that haven't been previously seen by the FNNs are then used to evaluate their ability in fault diagnosis. The trained neural networks provide very accurate diagnosis for suction and discharge valve defects.

Design of compressors for FEL pulses using deformable gratings

NASA Astrophysics Data System (ADS)

Bonora, Stefano; Fabris, Nicola; Frassetto, Fabio; Giovine, Ennio; Miotti, Paolo; Quintavalla, Martino; Poletto, Luca

2017-06-01

We present the optical layout of soft X-rays compressors using reflective grating specifically designed to give both positive or negative group-delay dispersion (GDD). They are tailored for chirped-pulse-amplification experiments with FEL sources. The optical design originates from an existing compressor with plane gratings already realized and tested at FERMI, that has been demonstrated capable to introduce tunable negative GDD. Here, we discuss two novel designs for compressors using deformable gratings capable to give both negative and positive GDD. Two novel designs are discussed: 1) a design with two deformable gratings and an intermediate focus between the twos, that is demonstrated capable to introduce positive GDD; 2) a design with one deformable grating giving an intermediate focus, followed by a concave mirror and a plane grating, that is capable to give both positive and negative GDD depending on the distance between the second mirror and the second grating. Both the designs are tunable in wavelength and GDD, by acting on the deformable gratings, that are rotated to tune the wavelength and the GDD and deformed to introduce the radius required to keep the spectral focus. The deformable gratings have a laminar profile and are ruled on a thin silicon plane substrate. A piezoelectric actuator is glued on the back of the substrate and is actuated to give a radius of curvature that is varying from infinite (plane) to few meters. The ruling procedure, the piezoelectric actuator and the efficiency measurements in the soft X-rays will be presented. Some test cases are discussed for wavelengths shorter than 12 nm.

Preliminary design study of advanced multistage axial flow core compressors

NASA Technical Reports Server (NTRS)

Wisler, D. C.; Koch, C. C.; Smith, L. H., Jr.

1977-01-01

A preliminary design study was conducted to identify an advanced core compressor for use in new high-bypass-ratio turbofan engines to be introduced into commercial service in the 1980's. An evaluation of anticipated compressor and related component 1985 state-of-the-art technology was conducted. A parametric screening study covering a large number of compressor designs was conducted to determine the influence of the major compressor design features on efficiency, weight, cost, blade life, aircraft direct operating cost, and fuel usage. The trends observed in the parametric screening study were used to develop three high-efficiency, high-economic-payoff compressor designs. These three compressors were studied in greater detail to better evaluate their aerodynamic and mechanical feasibility.

Stage-by-Stage and Parallel Flow Path Compressor Modeling for a Variable Cycle Engine

NASA Technical Reports Server (NTRS)

Kopasakis, George; Connolly, Joseph W.; Cheng, Larry

2015-01-01

This paper covers the development of stage-by-stage and parallel flow path compressor modeling approaches for a Variable Cycle Engine. The stage-by-stage compressor modeling approach is an extension of a technique for lumped volume dynamics and performance characteristic modeling. It was developed to improve the accuracy of axial compressor dynamics over lumped volume dynamics modeling. The stage-by-stage compressor model presented here is formulated into a parallel flow path model that includes both axial and rotational dynamics. This is done to enable the study of compressor and propulsion system dynamic performance under flow distortion conditions. The approaches utilized here are generic and should be applicable for the modeling of any axial flow compressor design.

Field testing energy-saving hermetic compressors in residential refrigerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sauber, R.S.; Middleton, M.G.

The design of an energy-saving compressor for low back pressure applications is reviewed. Calorimeter performance results are stated for two sizes of the efficient design and compared with performance test results for a standard compressor. Power consumption of a refrigerator-freezer is given with a standard compressor and with the energy-saving compressor. The preparation of the refrigerators used in the field test is discussed, along with the criteria used in selecting the instrumentation for the project. Results of the energy-saving compressor in the field test, along with a comparison to a standard production compressor, are presented. Some conclusions are drawn, basedmore » on the data, in relation to important factors in residential refrigerator power consumption.« less

Field testing energy-saving hermetic compressors in residential refrigerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sauber, R.S.; Middleton, M.G.

The design of an energy saving compressor for low back pressure applications is reviewed. Calorimeter performance results are stated for two sizes of the efficient design and compared with performance test results for a standard compressor. Power consumption of a refrigerator-freezer is given with a standard compressor and with the energy saving compressor. The preparation of the refrigerators used in the field test are discussed along with the criteria used in selecting the instrumentation for the project. Results of the energy saving compressor in the field test along with a comparison to a standard production compressor are presented. Some conclusionsmore » are drawn, based on the data, in relation to important factors in residential refrigerator power consumption.« less

Trends in high performance compressors for petrochemical and natural gas industry in China

NASA Astrophysics Data System (ADS)

Zhao, Yuanyang; Li, Liansheng

2015-08-01

Compressors are the key equipment in the petrochemical and natural gas industry system. The performance and reliability of them are very important for the process system. The application status of petrochemical & natural gas compressors in China is presented in this paper. The present status of design and operating technologies of compressors in China are mentioned in this paper. The turbo, reciprocating and twin screw compressors are discussed. The market demands for different structure compressors in process gas industries are analysed. This paper also introduces the research and developments for high performance compressors in China. The recent research results on efficiency improvement methods, stability improvement, online monitor and fault diagnosis will also be presented in details.

46 CFR 154.1415 - Air compressor.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Air compressor. 154.1415 Section 154.1415 Shipping COAST... Equipment § 154.1415 Air compressor. Each vessel must have an air compressor to recharge the bottles for the air-breathing apparatus. ...

46 CFR 154.1415 - Air compressor.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Air compressor. 154.1415 Section 154.1415 Shipping COAST... Equipment § 154.1415 Air compressor. Each vessel must have an air compressor to recharge the bottles for the air-breathing apparatus. ...

46 CFR 154.1415 - Air compressor.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Air compressor. 154.1415 Section 154.1415 Shipping COAST... Equipment § 154.1415 Air compressor. Each vessel must have an air compressor to recharge the bottles for the air-breathing apparatus. ...

46 CFR 154.1415 - Air compressor.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Air compressor. 154.1415 Section 154.1415 Shipping COAST... Equipment § 154.1415 Air compressor. Each vessel must have an air compressor to recharge the bottles for the air-breathing apparatus. ...

46 CFR 154.1415 - Air compressor.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Air compressor. 154.1415 Section 154.1415 Shipping COAST... Equipment § 154.1415 Air compressor. Each vessel must have an air compressor to recharge the bottles for the air-breathing apparatus. ...

Compressor Study to Meet Large Civil Tilt Rotor Engine Requirements

NASA Technical Reports Server (NTRS)

Veres, Joseph P.

2009-01-01

A vehicle concept study has been made to meet the requirements of the Large Civil Tilt Rotorcraft vehicle mission. A vehicle concept was determined, and a notional turboshaft engine system study was conducted. The engine study defined requirements for the major engine components, including the compressor. The compressor design-point goal was to deliver a pressure ratio of 31:1 at an inlet weight flow of 28.4 lbm/sec. To perform a conceptual design of two potential compressor configurations to meet the design requirement, a mean-line compressor flow analysis and design code were used. The first configuration is an eight-stage axial compressor. Some challenges of the all-axial compressor are the small blade spans of the rear-block stages being 0.28 in., resulting in the last-stage blade tip clearance-to-span ratio of 2.4%. The second configuration is a seven-stage axial compressor, with a centrifugal stage having a 0.28-in. impeller-exit blade span. The compressors conceptual designs helped estimate the flow path dimensions, rotor leading and trailing edge blade angles, flow conditions, and velocity triangles for each stage.

Compressor Study to Meet Large Civil Tilt Rotor Engine Requirements

NASA Technical Reports Server (NTRS)

Veres, Joseph P.

2009-01-01

A vehicle concept study has been made to meet the requirements of the Large Civil Tilt Rotorcraft vehicle mission. A vehicle concept was determined, and a notional turboshaft engine system study was conducted. The engine study defined requirements for the major engine components, including the compressor. The compressor design-point goal was to deliver a pressure ratio of 31:1 at an inlet weight flow of 28.4 lbm/sec. To perform a conceptual design of two potential compressor configurations to meet the design requirement, a mean-line compressor flow analysis and design code were used. The first configuration is an eight-stage axial compressor. Some challenges of the all-axial compressor are the small blade spans of the rear-block stages being 0.28 in., resulting in the last-stage blade tip clearance-to-span ratio of 2.4 percent. The second configuration is a seven-stage axial compressor, with a centrifugal stage having a 0.28-in. impeller-exit blade span. The compressors conceptual designs helped estimate the flow path dimensions, rotor leading and trailing edge blade angles, flow conditions, and velocity triangles for each stage.

An Analysis of Multiple Configurations of Next-Generation Cathodes in a Low Power Hall Thruster

DTIC Science & Technology

2009-03-01

compressor, the roughing pump , and the cryo-head temperature indicators. Figure 6. SPASS lab vacuum chamber and associated components. To measure...in progress to add additional cryo- pumps to the existing vacuum chamber that may allow higher propellant flow rates without exceeding ~1x10-5 torr... Vacuum Facility .........................................................................................................45 Test Assembly

An investigation of rotor tip leakage flows in the rear-block of a multistage compressor

NASA Astrophysics Data System (ADS)

Brossman, John Richard

An effective method to improve gas turbine propulsive efficiency is to increase the bypass ratio. With fan diameter reaching a practical limit, increases in bypass ratio can be obtained from reduced core engine size. Decreasing the engine core, results in small, high pressure compressor blading, and large relative tip clearances. At general rule of 1% reduction in compressor efficiency with a 1% increase in tip clearance, a 0.66% change in SFC indicates the entire engine is sensitive to high pressure compressor tip leakage flows. Therefore, further investigations and understanding of the rotor tip leakage flows can help to improve gas turbine engine efficiency. The objectives of this research were to investigate tip leakage flows through computational modeling, examine the baseline experimental steady-stage performance, and acquire unsteady static pressure, over-the rotor to observe the tip leakage flow structure. While tip leakage flows have been investigated in the past, there have been no facilities capable of matching engine representative Reynolds number and Mach number while maintaining blade row interactions, presenting a unique and original flow field to investigate at the Purdue 3-stage axial compressor facility. To aid the design of experimental hardware and determine the influence of clearance geometry on compressor performance, a computational model of the Purdue 3-stage compressor was investigated using a steady RANS CFD analysis. A cropped rotor and casing recess design was investigated to increase the rotor tip clearance. While there were small performance differences between the geometries, the tip leakage flow field was found independent of the design therefore designing future experimental hardware around a casing recess is valid. The largest clearance with flow margin past the design point was 4% tip clearance based on the computational model. The Purdue 3-stage axial compressor facility was rebuilt and setup for high quality, detailed flow measurements during this investigation. A detailed investigation and sensitivity analysis of the inlet flow field found the influence by the inlet total temperature profile was important to performance calculations. This finding was significant and original as previous investigations have been conducted on low-speed machines where there is minimal temperature rise. The steady state performance of the baseline 1.5% tip clearance case was outlined at design speed and three off-design speeds. The leakage flow from the rear seal, the inlet flow field and a thermal boundary condition over the casing was recorded at each operating point. Stage 1 was found to be the limiting stage independent of speed. Few datasets exist on multistage compressor performance with full boundary condition definitions, especially with off-design operating points presenting this as a unique dataset for CFD comparison. The detailed unsteady pressure measurements were conducted over Rotor 1 at design and a near-stall operating condition to characterize the leakage trajectory and position. The leakage flow initial point closer to the leading edge and trajectory angle increased at the higher loading condition. The over-the-rotor static pressure field on Rotor 1 indicated similar trends between the computational model and the leakage trajectory.

Investigation of TESCOM Driveshaft Assembly Failure

DTIC Science & Technology

1998-10-01

ratio, two-stage axial -flow compressor with a corrected tip speed of 1250 ft/sec at design . The flowpath casing diameter downstream of the inlet... Design of a 1250 ft/sec. Low-Aspect-Ratio, Single-Stage Axial -Flow Compressor , AFAPL-TR-79-2096, Air Force Aero Propulsion Laboratory, Wright...The TESCOM compressor described in this report is a 2.5-stage, low aspect ratio, axial -flow compressor . The performance objectives of this compressor

Development of a J-T Micro Compressor

NASA Astrophysics Data System (ADS)

Champagne, P.; Olson, J. R.; Nast, T.; Roth, E.; Collaco, A.; Kaldas, G.; Saito, E.; Loung, V.

2015-12-01

Lockheed Martin has developed and tested a space-quality compressor capable of delivering closed-loop gas flow with a high pressure ratio, suitable for driving a Joule- Thomson cold head. The compressor is based on a traditional “Oxford style” dual-opposed piston compressor with linear drive motors and flexure-bearing clearance-seal technology for high reliability and long life. This J-T compressor retains the approximate size, weight, and cost of the ultra-compact, 200 gram Lockheed Martin Pulse Tube Micro Compressor, despite the addition of a flow-rectifying system to convert the AC pressure wave into a steady flow.

Extended range heat pump system and centrifugal compressor for use therewith

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shoemaker, J.F.

1988-04-26

Improvements in heat pump systems having indoor and outdoor heat exchangers and at least two compressors for supplying a refrigerant medium under pressure thereto, and means for circulating the medium through the heat exchangers, the improvement is described comprising a selector valve associated with each of the compressors. The selector valves provide that any combination and any one or more of the compressors can be selected for operation, each of the selector valves having a first operating condition placing the associated compressor in series with the heat exchangers and a second operating condition whereby the associated compressor is bypassed, whenmore » the selector valves for at least two of the compressors are simultaneously in their first positions a flow path is established through the associated compressors and through the heat exchangers all in series, a two position changeover valve and associated conduit means. The changeover valve has a first position wherein at least one of the compressors is connected in series with the first and second heat exchangers to produce flow of the medium in one direction therethrough and a second position whereby at least one compressor is connected to produce flow of the medium in the opposite direction through the heat exchangers.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

SADE is a software package for rapidly assembling analytic pipelines to manipulate data. The packages consists of the engine that manages the data and coordinates the movement of data between the tasks performing a function? a set of core libraries consisting of plugins that perform common tasks? and a framework to extend the system supporting the development of new plugins. Currently through configuration files, a pipeline can be defined that maps the routing of data through a series of plugins. Pipelines can be run in a batch mode or can process streaming data? they can be executed from the commandmore » line or run through a Windows background service. There currently exists over a hundred plugins, over fifty pipeline configurations? and the software is now being used by about a half-dozen projects.« less

Modelling of non-equilibrium flow in the branched pipeline systems

NASA Astrophysics Data System (ADS)

Sumskoi, S. I.; Sverchkov, A. M.; Lisanov, M. V.; Egorov, A. F.

2016-09-01

This article presents a mathematical model and a numerical method for solving the task of water hammer in the branched pipeline system. The task is considered in the onedimensional non-stationary formulation taking into account the realities such as the change in the diameter of the pipeline and its branches. By comparison with the existing analytic solution it has been shown that the proposed method possesses good accuracy. With the help of the developed model and numerical method the task has been solved concerning the transmission of the compression waves complex in the branching pipeline system when several shut down valves operate. It should be noted that the offered model and method may be easily introduced to a number of other tasks, for example, to describe the flow of blood in the vessels.

An analytical study of hybrid ejector/internal combustion engine-driven heat pumps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, R.W.

1988-01-01

Because ejectors can combine high reliability with low maintenance cost in a package requiring little capital investment, they may provide attractive heat pumping capability in situations where the importance of their inefficiencies is minimized. One such concept, a hybrid system in which an ejector driven by engine reject heat is used to increase the performance of an internal combustion engine-driven heat pump, was analyzed by modifying an existing ejector heat pump model and combining it with generic compressor and internal combustion engine models. Under the model assumptions for nominal cooling mode conditions, the results showed that hybrid systems could providemore » substantial performance augmentation/emdash/up to 17/percent/ increase in system coefficient of performance for a parallel arrangement of an enhanced ejector with the engine-driven compressor. 4 refs., 4 figs., 4 tabs.« less

Estimate for interstage water injection in air compressor incorporated into gas-turbine cycles and combined power plants cycles

NASA Astrophysics Data System (ADS)

Kler, A. M.; Zakharov, Yu. B.; Potanina, Yu. M.

2017-05-01

The objects of study are the gas turbine (GT) plant and combined cycle power plant (CCPP) with opportunity for injection between the stages of air compressor. The objective of this paper is technical and economy optimization calculations for these classes of plants with water interstage injection. The integrated development environment "System of machine building program" was a tool for creating the mathematic models for these classes of power plants. Optimization calculations with the criterion of minimum for specific capital investment as a function of the unit efficiency have been carried out. For a gas-turbine plant, the economic gain from water injection exists for entire range of power efficiency. For the combined cycle plant, the economic benefit was observed only for a certain range of plant's power efficiency.

Vapor cycle cooling system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Midolo, L.

1980-07-08

A description is given of a rotary vane cooling system including a two phase coolant, comprising: a vaporizable liquid working medium within said cooling system; an evaporator having an inlet and an outlet; a condenser having an inlet and an outlet; a two stage rotary vane compressor, including means for connecting the outlet of a first compressor stage to the inlet of a second compressor stage; said two stage rotary vane compressor being connected between the outlet of said evaporator and the inlet at said condenser; an expansion device connected between the outlet of said condenser and the inlet ofmore » said evaporator; said two stage compressor including a housing having a chamber therein, a rotor on a rotatable shaft; said rotor being positioned within said chamber; said rotor having a plurality of slidable vanes which form a plurality of cells, within said chamber, which change in volume as the rotor rotates; said plurality of cells including a pluraity of cells on one side of said rotor which corresponds to said first compressor stage and a plurality of cells on the other side of said rotor which corresponds to said second compressor stage; said cells corresponding to said first compressor stage having a greater maximum volume than the cells corresponding to said second compressor stage; and means for supplying at least a portion of the vapor resulting from the expansion in said expansion device to the inlet of the second compressor stage for providing cooling in the inlet of said second compressor stage.« less

Novel Long Stroke Reciprocating Compressor for Energy Efficient Jaggery Making

NASA Astrophysics Data System (ADS)

Rane, M. V.; Uphade, D. B.

2017-08-01

Novel Long Stroke Reciprocating Compressor is analysed for jaggery making while avoiding burning of bagasse for concentrating juice. Heat of evaporated water vapour along with small compressor work is recycled to enable boiling of juice. Condensate formed during heating of juice is pure water, as oil-less compressor is used. Superheat of compressor is suppressed by flow of superheated vapours through condensate. It limits heating surface temperature and avoids caramelization of sugar. Thereby improves quality of jaggery and eliminates need to use chemicals for colour improvement. Stroke to bore ratio is 0.6 to 1.2 in conventional reciprocating drives. Long stroke in reciprocating compressors enhances heat dissipation to surrounding by providing large surface area and increases isentropic efficiency by reducing compressor outlet temperature. Longer stroke increases inlet and exit valve operation timings, which reduces inertial effects substantially. Thereby allowing use of sturdier valves. This enables handling liquid along with vapour in compressors. Thereby supressing the superheat and reducing compressor power input. Longer stroke increases stroke to clearance ratios which increases volumetric efficiency and ability of compressor to compress through higher pressure ratios efficiently. Stress-strain simulation is performed in SolidWorks for gear drive. Long Stroke Reciprocating Compressor is developed at Heat Pump Laboratory, stroke/bore 292 mm/32 mm. It is operated and tested successfully at different speeds for operational stability of components. Theoretical volumetric efficiency is 93.9% at pressure ratio 2.0. Specific energy consumption is 108.3 kWhe/m3 separated water, considering free run power.

40 CFR 204.55-3 - Configuration identification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS NOISE EMISSION STANDARDS FOR CONSTRUCTION EQUIPMENT Portable Air Compressors § 204.55-3... the following parameters: (1) The compressor type (screw, sliding vane, etc.). (2) Number of compressor stages. (3) Maximum pressure (psi). (4) Air intake system of compressor: (i) Number of filters...

ETR COMPRESSOR BUILDING, TRA643. COMPRESSORS AND OTHER EQUIPMENT INSTALLED. METAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR COMPRESSOR BUILDING, TRA-643. COMPRESSORS AND OTHER EQUIPMENT INSTALLED. METAL ROOF AND CONCRETE BLOCK WALLS. INL NEGATIVE NO. 61-4536. Unknown Photographer, ca. 1961. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Stator Indexing in Multistage Compressors

NASA Technical Reports Server (NTRS)

Barankiewicz, Wendy S.

1997-01-01

The relative circumferential location of stator rows (stator indexing) is an aspect of multistage compressor design that has not yet been explored for its potential impact on compressor aerodynamic performance. Although the inlet stages of multistage compressors usually have differing stator blade counts, the aft stages of core compressors can often have stage blocks with equal stator blade counts in successive stages. The potential impact of stator indexing is likely greatest in these stages. To assess the performance impact of stator indexing, researchers at the NASA Lewis Research Center used the 4 ft diameter, four-stage NASA Low Speed Axial Compressor for detailed experiments. This compressor has geometrically identical stages that can circumferentially index stator rows relative to each other in a controlled manner; thus it is an ideal test rig for such investigations.

Research and development of energy-efficient high back-pressure compressor

NASA Astrophysics Data System (ADS)

1983-09-01

Improved-efficiency compressors were developed in four capacity sizes. Changes to the baseline compressor were made to the motors, valve plates, and mufflers. The adoption of a slower running speed compressor required larger displacements to maintain the desired capacity. This involved both bore and stroke modifications. All changes that were made to the compressor are readily adaptable to manufacture. Prototype compressors were built and tested. The largest capacity size (4000 Btu/h) was selected for testing in a vending machine. Additional testing was performed on the prototype compressors in order to rate them on an alternate refrigerant. A market analysis was performed to determine the potential acceptance of the improved-efficiency machines by a vending machine manufacturer, who supplies a retail sales system of a major soft drink company.

Recirculating rotary gas compressor

DOEpatents

Weinbrecht, John F.

1992-01-01

A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

New concept single screw compressors and their manufacture technology

NASA Astrophysics Data System (ADS)

Feng, Q.; Liu, F.; Chang, L.; Feng, C.; Peng, C.; Xie, J.; van den Broek, M.

2017-08-01

Single screw compressors were generally acknowledged as one of the nearly perfect machines by compressor researchers and manufacturers. However the rapid wear of the star-wheel in a single screw compressor during operation is a key reason why it hasn’t previously joined the main current compressors’ market. After more than ten years of effective work, the authors of this paper have proposed a new concept single screw compressor whose mesh-couple profile is enveloped with multi-column. Also a new design method and manufacture equipment for this kind of compressor have been developed and are described in this paper. A lot of prototype tests and a long period of industrial operations under full loading conditions have shown that the mesh-couple profiles of the new concept single compressors have excellent anti-wearness.

Recirculating rotary gas compressor

DOEpatents

Weinbrecht, J.F.

1992-02-25

A positive displacement, recirculating Roots-type rotary gas compressor is described which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits which return compressed discharge gas to the compressor housing, where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor. 12 figs.

Centrifugal Compressor Surge Controlled

NASA Technical Reports Server (NTRS)

Skoch, Gary J.

2003-01-01

It shows the variation in compressor mass flow with time as the mass flow is throttled to drive the compressor into surge. Surge begins where wide variations in mass flow occur. Air injection is then turned on to bring about a recovery from the initial surge condition and stabilize the compressor. The throttle is closed further until surge is again initiated. Air injection is increased to again recover from the surge condition and stabilize the compressor.

Three-Dimensional Aerodynamic Instabilities In Multi-Stage Axial Compressors

NASA Technical Reports Server (NTRS)

Tan, Choon S.; Gong, Yifang; Suder, Kenneth L. (Technical Monitor)

2001-01-01

This thesis presents the conceptualization and development of a computational model for describing three-dimensional non-linear disturbances associated with instability and inlet distortion in multistage compressors. Specifically, the model is aimed at simulating the non-linear aspects of short wavelength stall inception, part span stall cells, and compressor response to three-dimensional inlet distortions. The computed results demonstrated the first-of-a-kind capability for simulating short wavelength stall inception in multistage compressors. The adequacy of the model is demonstrated by its application to reproduce the following phenomena: (1) response of a compressor to a square-wave total pressure inlet distortion; (2) behavior of long wavelength small amplitude disturbances in compressors; (3) short wavelength stall inception in a multistage compressor and the occurrence of rotating stall inception on the negatively sloped portion of the compressor characteristic; (4) progressive stalling behavior in the first stage in a mismatched multistage compressor; (5) change of stall inception type (from modal to spike and vice versa) due to IGV stagger angle variation, and "unique rotor tip incidence" at these points where the compressor stalls through short wavelength disturbances. The model has been applied to determine the parametric dependence of instability inception behavior in terms of amplitude and spatial distribution of initial disturbance, and intra-blade-row gaps. It is found that reducing the inter-blade row gaps suppresses the growth of short wavelength disturbances. It is also concluded from these parametric investigations that each local component group (rotor and its two adjacent stators) has its own instability point (i.e. conditions at which disturbances are sustained) for short wavelength disturbances, with the instability point for the compressor set by the most unstable component group. For completeness, the methodology has been extended to describe finite amplitude disturbances in high-speed compressors. Results are presented for the response of a transonic compressor subjected to inlet distortions.

Changes in the Arctic: Background and Issues for Congress

DTIC Science & Technology

2016-05-12

discovery of new oil and gas deposits far from existing storage, pipelines , and shipping facilities cannot be developed until infrastructure is built...markets. Other questions in need of answers include the status of port, pipeline , and liquid natural gas infrastructure; whether methane hydrates...Changes to the Arctic brought about by warming temperatures will likely allow more exploration for oil, gas , and minerals. Warming that causes

49 CFR 192.167 - Compressor stations: Emergency shutdown.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Components § 192.167 Compressor stations: Emergency shutdown. (a) Except for unattended field compressor... fires, and electrical facilities in the vicinity of gas headers and in the compressor building, except that: (i) Electrical circuits that supply emergency lighting required to assist station personnel in...

49 CFR 192.167 - Compressor stations: Emergency shutdown.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Components § 192.167 Compressor stations: Emergency shutdown. (a) Except for unattended field compressor... fires, and electrical facilities in the vicinity of gas headers and in the compressor building, except that: (i) Electrical circuits that supply emergency lighting required to assist station personnel in...

Oil flow at the scroll compressor discharge: visualization and CFD simulation

NASA Astrophysics Data System (ADS)

Xu, Jiu; Hrnjak, Pega

2017-08-01

Oil is important to the compressor but has other side effect on the refrigeration system performance. Discharge valves located in the compressor plenum are the gateway for the oil when leaving the compressor and circulate in the system. The space in between: the compressor discharge plenum has the potential to separate the oil mist and reduce the oil circulation ratio (OCR) in the system. In order to provide information for building incorporated separation feature for the oil flow near the compressor discharge, video processing method is used to quantify the oil droplets movement and distribution. Also, CFD discrete phase model gives the numerical approach to study the oil flow inside compressor plenum. Oil droplet size distributions are given by visualization and simulation and the results show a good agreement. The mass balance and spatial distribution are also discussed and compared with experimental results. The verification shows that discrete phase model has the potential to simulate the oil droplet flow inside the compressor.

Technology’s present situation and the development prospects of energy efficiency monitoring as well as performance testing & analysis for process flow compressors

NASA Astrophysics Data System (ADS)

Li, L.; Zhao, Y.; Wang, L.; Yang, Q.; Liu, G.; Tang, B.; Xiao, J.

2017-08-01

In this paper, the background of performance testing of in-service process flow compressors set in user field are introduced, the main technique barriers faced in the field test are summarized, and the factors that result in real efficiencies of most process flow compressors being lower than the guaranteed by manufacturer are analysed. The authors investigated the present operational situation of process flow compressors in China and found that low efficiency operation of flow compressors is because the compressed gas is generally forced to flow back into the inlet pipe for adapting to the process parameters variety. For example, the anti-surge valve is always opened for centrifugal compressor. To improve the operation efficiency of process compressors the energy efficiency monitoring technology was overviewed and some suggestions are proposed in the paper, which is the basis of research on energy efficiency evaluation and/or labelling of process compressors.

Basic overview towards the assessment of landslide and subsidence risks along a geothermal pipeline network

NASA Astrophysics Data System (ADS)

Astisiasari; Van Westen, Cees; Jetten, Victor; van der Meer, Freek; Rahmawati Hizbaron, Dyah

2017-12-01

An operating geothermal power plant consists of installation units that work systematically in a network. The pipeline network connects various engineering structures, e.g. well pads, separator, scrubber, and power station, in the process of transferring geothermal fluids to generate electricity. Besides, a pipeline infrastructure also delivers the brine back to earth, through the injection well-pads. Despite of its important functions, a geothermal pipeline may bear a threat to its vicinity through a pipeline failure. The pipeline can be impacted by perilous events like landslides, earthquakes, and subsidence. The pipeline failure itself may relate to physical deterioration over time, e.g. due to corrosion and fatigue. The geothermal reservoirs are usually located in mountainous areas that are associated with steep slopes, complex geology, and weathered soil. Geothermal areas record a noteworthy number of disasters, especially due to landslide and subsidence. Therefore, a proper multi-risk assessment along the geothermal pipeline is required, particularly for these two types of hazard. This is also to mention that the impact on human fatality and injury is not presently discussed here. This paper aims to give a basic overview on the existing approaches for the assessment of multi-risk assessment along geothermal pipelines. It delivers basic principles on the analysis of risks and its contributing variables, in order to model the loss consequences. By considering the loss consequences, as well as the alternatives for mitigation measures, the environmental safety in geothermal working area could be enforced.

A computational genomics pipeline for prokaryotic sequencing projects.

PubMed

Kislyuk, Andrey O; Katz, Lee S; Agrawal, Sonia; Hagen, Matthew S; Conley, Andrew B; Jayaraman, Pushkala; Nelakuditi, Viswateja; Humphrey, Jay C; Sammons, Scott A; Govil, Dhwani; Mair, Raydel D; Tatti, Kathleen M; Tondella, Maria L; Harcourt, Brian H; Mayer, Leonard W; Jordan, I King

2010-08-01

New sequencing technologies have accelerated research on prokaryotic genomes and have made genome sequencing operations outside major genome sequencing centers routine. However, no off-the-shelf solution exists for the combined assembly, gene prediction, genome annotation and data presentation necessary to interpret sequencing data. The resulting requirement to invest significant resources into custom informatics support for genome sequencing projects remains a major impediment to the accessibility of high-throughput sequence data. We present a self-contained, automated high-throughput open source genome sequencing and computational genomics pipeline suitable for prokaryotic sequencing projects. The pipeline has been used at the Georgia Institute of Technology and the Centers for Disease Control and Prevention for the analysis of Neisseria meningitidis and Bordetella bronchiseptica genomes. The pipeline is capable of enhanced or manually assisted reference-based assembly using multiple assemblers and modes; gene predictor combining; and functional annotation of genes and gene products. Because every component of the pipeline is executed on a local machine with no need to access resources over the Internet, the pipeline is suitable for projects of a sensitive nature. Annotation of virulence-related features makes the pipeline particularly useful for projects working with pathogenic prokaryotes. The pipeline is licensed under the open-source GNU General Public License and available at the Georgia Tech Neisseria Base (http://nbase.biology.gatech.edu/). The pipeline is implemented with a combination of Perl, Bourne Shell and MySQL and is compatible with Linux and other Unix systems.

Physics based modeling of axial compressor stall

NASA Astrophysics Data System (ADS)

Zaki, Mina Adel

2009-12-01

Axial compressors are used in a wide variety of aerodynamic applications and are one of the most important components in aero-engines. However, the operability of compressors is limited at low-mass flow rates by fluid dynamic instabilities such as stall and surge. These instabilities can lead to engine failure and loss of engine power which can compromise the aircraft safety and reliability. Thus, a better understanding of how stall occurs and the causes behind its inception is extremely important. In the vicinity of the stall line, the flow field is inherently unsteady due to the interactions between adjacent rows of blades, formation of separation cells, and the viscous effects including shock-boundary layer interactions. Accurate modeling of these phenomena requires a proper set of stable and accurate boundary conditions at the rotor-stator interface that conserve mass, momentum, and energy, while eliminating false reflections. As a part of this research effort, an existing 3-D Navier-Stokes analysis for modeling single stage compressors has been modified to model multi-stage axial compressors and turbines. Several rotor-stator interface boundary conditions have been implemented. These conditions have been evaluated for the first stage (a stator and a rotor) of the two-stage fuel turbine on the space shuttle main engine (SSME). Their effectiveness in conserving global properties such as mass, momentum, and energy across the interface while yielding good performance predictions has been evaluated. While all the methods gave satisfactory results, a characteristic based approach and an unsteady sliding mesh approach are found to work best. Accurate modeling of the formation of stall cells requires the use of advanced turbulence models. As a part of this effort, a new advanced turbulence model called the Hybrid RANS/KES (HRKES) model has been developed and implemented. This model solves the Menter's k-o-SST model near walls and switches to the Kinetic Eddy Simulation (KES) model away from walls. The KES model solves directly for local turbulent kinetic energy and local turbulent length scales, alleviating the grid spacing dependency of the length scales found in other Detached Eddy Simulation (DES) and Hybrid RANS/LES (HRLES) models. Within the HRKES model, combinations of two different blending functions have been evaluated for integrating the near wall model with the KES model. The use of realizability constraints to bound the KES model parameters has also been studied for several internal and external flows. The current methodology is used in the prediction of the performance map for the NASA Stage 35 compressor configuration as a representative of a modern compressor stage. The present approach is found to effectively predict the onset of stall. It is found that the rotor blade tip leakage vortex and its interaction with the shock wave is mainly the reason behind the stall inception in this compressor stage.

Linear infrastructure drives habitat conversion and forest fragmentation associated with Marcellus shale gas development in a forested landscape.

PubMed

Langlois, Lillie A; Drohan, Patrick J; Brittingham, Margaret C

2017-07-15

Large, continuous forest provides critical habitat for some species of forest dependent wildlife. The rapid expansion of shale gas development within the northern Appalachians results in direct loss of such habitat at well sites, pipelines, and access roads; however the resulting habitat fragmentation surrounding such areas may be of greater importance. Previous research has suggested that infrastructure supporting gas development is the driver for habitat loss, but knowledge of what specific infrastructure affects habitat is limited by a lack of spatial tracking of infrastructure development in different land uses. We used high-resolution aerial imagery, land cover data, and well point data to quantify shale gas development across four time periods (2010, 2012, 2014, 2016), including: the number of wells permitted, drilled, and producing gas (a measure of pipeline development); land use change; and forest fragmentation on both private and public land. As of April 2016, the majority of shale gas development was located on private land (74% of constructed well pads); however, the number of wells drilled per pad was lower on private compared to public land (3.5 and 5.4, respectively). Loss of core forest was more than double on private than public land (4.3 and 2.0%, respectively), which likely results from better management practices implemented on public land. Pipelines were by far the largest contributor to the fragmentation of core forest due to shale gas development. Forecasting future land use change resulting from gas development suggests that the greatest loss of core forest will occur with pads constructed farthest from pre-existing pipelines (new pipelines must be built to connect pads) and in areas with greater amounts of core forest. To reduce future fragmentation, our results suggest new pads should be placed near pre-existing pipelines and methods to consolidate pipelines with other infrastructure should be used. Without these mitigation practices, we will continue to lose core forest as a result of new pipelines and infrastructure particularly on private land. Copyright © 2017 Elsevier Ltd. All rights reserved.

Layout of bunch compressor for Beijing XFEL test facility

NASA Astrophysics Data System (ADS)

Zhu, Xiongwei; Du, Yingchao; He, Xiaozhong; Yang, Yufeng

2006-10-01

In this paper, we describe the layout of the bunch compressor for the Beijing XFEL test facility (BTF). Our bunch compressor setup is different from the usual one due to the space limit. The compensation X-BAND cavity and the first bunch compressor are separate in distance. The electron bunch is decelerated first and then accelerated to enter the first bunch compressor. The simulation result shows that our setup works well, and the nonlinear term is well compensated. Also, we present the result about the CSR emittance dilution study. Finally, we develop a program to study microbunch instability in the second BTF bunch compressor.

Three-wheel air turbocompressor for PEM fuel cell systems

DOEpatents

Rehg, Tim; Gee, Mark; Emerson, Terence P.; Ferrall, Joe; Sokolov, Pavel

2003-08-19

A fuel cell system comprises a compressor and a fuel processor downstream of the compressor. A fuel cell stack is in communication with the fuel processor and compressor. A combustor is downstream of the fuel cell stack. First and second turbines are downstream of the fuel processor and in parallel flow communication with one another. A distribution valve is in communication with the first and second turbines. The first and second turbines are mechanically engaged to the compressor. A bypass valve is intermediate the compressor and the second turbine, with the bypass valve enabling a compressed gas from the compressor to bypass the fuel processor.

Multiple volume compressor for hot gas engine

DOEpatents

Stotts, Robert E.

1986-01-01

A multiple volume compressor for use in a hot gas (Stirling) engine having a plurality of different volume chambers arranged to pump down the engine when decreased power is called for and return the working gas to a storage tank or reservoir. A valve actuated bypass loop is placed over each chamber which can be opened to return gas discharged from the chamber back to the inlet thereto. By selectively actuating the bypass valves, a number of different compressor capacities can be attained without changing compressor speed whereby the capacity of the compressor can be matched to the power available from the engine which is used to drive the compressor.

Performance of J-33-A-21 and J-33-A-23 Compressors with and without Water Injection

NASA Technical Reports Server (NTRS)

Beede, William L.

1948-01-01

In an investigation of the J-33-A-21 and the J-33-A-23 compressors with and without water injection, it was discovered that the compressors reacted differently to water injection although they were physically similar. An analysis of the effect of water injection on compressor performance and the consequent effect on matching of the compressor and turbine components in the turbojet engine was made. The analysis of component matching is based on a turbine flow function defined as the product of the equivalent weight flow and the reciprocal of the compressor pressure ratio.

CF6 Jet Engine Diagnostics Program: High pressure compressor clearance investigation

NASA Technical Reports Server (NTRS)

Radomski, M. A.

1982-01-01

The effects of high pressure compressor clearance changes on engine performance were experimentally determined on a CF6 core engine. The results indicate that a one percent reduction in normalized average clearance, expressed as a fraction of airfoil length, improves compressor efficiency by one percent. Compressor clearances are reduced by the application of rotor bore cooling, insulation of the stator casing, and use of a low coefficient of expansion material in the aft stages. This improvement amounts to a reduction of normalized average clearance of 0.78 percent, relative to CF6-60 compressor, which is equivalent to an improvement in compressor efficiency of 0.78 percent.

A Stability Enhancement Method for Centrifugal Compressors using Active Control Casing Treatment System

NASA Astrophysics Data System (ADS)

Zhao, Yuanyang; Xiao, Jun; Li, Liansheng; Yang, Qichao; Liu, Guangbin; Wang, Le

2015-08-01

The centrifugal compressors are widely used in many fields. When the centrifugal compressors operate at the edge of the surge line, the compressor will be unstable. In addition, if the centrifugal compressor runs at this situation long time, the damage will be occurred on compressor. There are some kinds of method to improve and enlarge the range of the centrifugal compressors, such as inlet guide vane, and casing treatment. For casing treatment method, some structures have been researched, such as holed recirculation, basic slot casing treatment and groove casing treatment. All these researches are the passive methods. This paper present a new stability enhancement method based Active Control Casing Treatment (ACCT). All parts of this new method are introduced in detail. The control strategy of the system is mentioned in the paper. As a research sample, a centrifugal compressor having this system is researched using CFD method. The study focuses on the effect of the active control system on the impeller flow. The vortex in impeller is changed by the active control system. And this leads to the suppression of the extension of vortex blockage in impeller and to contribute to the enhancement of the compressor operating range.

30 CFR 56.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors...

30 CFR 56.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors...

30 CFR 56.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors...

30 CFR 56.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Reciprocating-type air compressors. 56.13010...

30 CFR 57.13010 - Reciprocating-type air compressors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Reciprocating-type air compressors. 57.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors...

Performance of Compressor of XJ-41-V Turbojet Engine. 1 - Preliminary Investigation at Equivalent Compressor Speed of 8000 rpm

DTIC Science & Technology

1949-01-01

Aircraft Engine Research Laboratory Cleveland, Ohio Restriction Cancelled ^mmmmmmmm ^Md’^| 5;-;» <^~ k NATIONAL ADVISORY COMMTTErUf0...AEEONAUTICS RESEARCH MEMORANDUM for the Air Materiel Command’, Army Air Forces PERFORMANCE OF COMPRESSOR OF XJ-41-V TURBOJET ENGINE I - PRELIMINARY...of the XJ-41-V turbojet - engine compressor. . .’ The complete compressor was amounted on a collecting chamber having an annular air-flow

Economics of water injected air screw compressor systems

NASA Astrophysics Data System (ADS)

Venu Madhav, K.; Kovačević, A.

2015-08-01

There is a growing need for compressed air free of entrained oil to be used in industry. In many cases it can be supplied by oil flooded screw compressors with multi stage filtration systems, or by oil free screw compressors. However, if water injected screw compressors can be made to operate reliably, they could be more efficient and therefore cheaper to operate. Unfortunately, to date, such machines have proved to be insufficiently reliable and not cost effective. This paper describes an investigation carried out to determine the current limitations of water injected screw compressor systems and how these could be overcome in the 15-315 kW power range and delivery pressures of 6-10 bar. Modern rotor profiles and approach to sealing and cooling allow reasonably inexpensive air end design. The prototype of the water injected screw compressor air system was built and tested for performance and reliability. The water injected compressor system was compared with the oil injected and oil free compressor systems of the equivalent size including the economic analysis based on the lifecycle costs. Based on the obtained results, it was concluded that water injected screw compressor systems could be designed to deliver clean air free of oil contamination with a better user value proposition than the oil injected or oil free screw compressor systems over the considered range of operations.

SUPRA: open-source software-defined ultrasound processing for real-time applications : A 2D and 3D pipeline from beamforming to B-mode.

PubMed

Göbl, Rüdiger; Navab, Nassir; Hennersperger, Christoph

2018-06-01

Research in ultrasound imaging is limited in reproducibility by two factors: First, many existing ultrasound pipelines are protected by intellectual property, rendering exchange of code difficult. Second, most pipelines are implemented in special hardware, resulting in limited flexibility of implemented processing steps on such platforms. With SUPRA, we propose an open-source pipeline for fully software-defined ultrasound processing for real-time applications to alleviate these problems. Covering all steps from beamforming to output of B-mode images, SUPRA can help improve the reproducibility of results and make modifications to the image acquisition mode accessible to the research community. We evaluate the pipeline qualitatively, quantitatively, and regarding its run time. The pipeline shows image quality comparable to a clinical system and backed by point spread function measurements a comparable resolution. Including all processing stages of a usual ultrasound pipeline, the run-time analysis shows that it can be executed in 2D and 3D on consumer GPUs in real time. Our software ultrasound pipeline opens up the research in image acquisition. Given access to ultrasound data from early stages (raw channel data, radiofrequency data), it simplifies the development in imaging. Furthermore, it tackles the reproducibility of research results, as code can be shared easily and even be executed without dedicated ultrasound hardware.

Cathodic protection - Coating and river profile survey of a 20 year old remote onshore crude pipeline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simon, P.

1984-02-01

This paper presents test data, evaluation and recommendations resulting from an investigative cathodic protection and coating integrity survey of a twenty year old, onshore crude oil pipeline. The pipeline discussed is 20 inches (508 mm) in diameter, 233 kilometers long and originates at a pumping facility in an inland oil field. The pipeline runs through mountainous terrain, low lying marshland and terminates at a twin 16 inch submarine crossing. The pipeline is located in Southern Kalimantan, Indonesia and is part of the Pertamina Unit IV installation. The field testing was performed by Norton Corrosion Limited (NCL) during the months ofmore » March and April, 1983 and was done concurrently with river crossing profile work by Sterling Energy and Resource Technologies, Limited. The purpose of the survey was to determine the condition of the pipeline and the condition and effectiveness of existing corrosion control measures. The pipeline had experienced an increasing number of leaks in recent years and it was necessary to know the physical condition of the line and what could be done to extend its useful life. The present and future integrity of the pipeline was critical to the clients' planning in that this particular line is the only onshore connection between the field and new refinery which was nearing completion.« less

Improving of the working process of axial compressors of gas turbine engines by using an optimization method

NASA Astrophysics Data System (ADS)

Marchukov, E.; Egorov, I.; Popov, G.; Baturin, O.; Goriachkin, E.; Novikova, Y.; Kolmakova, D.

2017-08-01

The article presents one optimization method for improving of the working process of an axial compressor of gas turbine engine. Developed method allows to perform search for the best geometry of compressor blades automatically by using optimization software IOSO and CFD software NUMECA Fine/Turbo. Optimization was performed by changing the form of the middle line in the three sections of each blade and shifts of three sections of the guide vanes in the circumferential and axial directions. The calculation of the compressor parameters was performed for work and stall point of its performance map on each optimization step. Study was carried out for seven-stage high-pressure compressor and three-stage low-pressure compressors. As a result of optimization, improvement of efficiency was achieved for all investigated compressors.

Application of Risk-Based Inspection method for gas compressor station

NASA Astrophysics Data System (ADS)

Zhang, Meng; Liang, Wei; Qiu, Zeyang; Lin, Yang

2017-05-01

According to the complex process and lots of equipment, there are risks in gas compressor station. At present, research on integrity management of gas compressor station is insufficient. In this paper, the basic principle of Risk Based Inspection (RBI) and the RBI methodology are studied; the process of RBI in the gas compressor station is developed. The corrosion loop and logistics loop of the gas compressor station are determined through the study of corrosion mechanism and process of the gas compressor station. The probability of failure is calculated by using the modified coefficient, and the consequence of failure is calculated by the quantitative method. In particular, we addressed the application of a RBI methodology in a gas compressor station. The risk ranking is helpful to find the best preventive plan for inspection in the case study.

Guidelines for riser splash zone design and repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-02-01

The many years of offshore oil and gas development has established the subsea pipeline as a reliable and cost effective means of transportation for produced hydrocarbons. The requirement for subsea pipeline systems will continue to move into deeper water and more remote locations with the future development of oil and gas exploration. The integrity of subsea pipeline and riser systems, throughout their operating lifetime, is an important area for operators to consider in maximizing reliability and serviceability for economic, contractual and environmental reasons. Adequate design and installation are the basis for ensuring the integrity of any subsea pipeline and risermore » systems. In the event of system damage, from any source, quick and accurate repair and reinstatement of the pipeline system is essential. This report has been developed to provide guidelines for riser and splash zone design, to perform a detailed overview of existing riser repair techniques and products, and to prepare comprehensive guidelines identifying the capabilities and limits of riser reinstatement systems.« less

Reclamation of the Wahsatch gathering system pipeline in southwestern Wyoming and northeastern Utah

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strickland, D.; Dern, G.; Johnson, G.

1996-12-31

The Union Pacific Resources Company (UPRC) constructed a 40.4 mile pipeline in 1993 in Summit and Rich Countries, Utah and Uinta County, Wyoming. The pipeline collects and delivers natural gas from six existing wells to the Whitney Canyon Processing Plant north of Evanston, Wyoming. We describe reclamation of the pipeline, the cooperation received from landowners along the right-of-way, and mitigation measures implemented by UPRC to minimize impacts to wildlife. The reclamation procedure combines a 2 step topsoil separation, mulching with natural vegetation, native seed mixes, and measures designed to reduce the visual impacts of the pipeline. Topsoil is separated intomore » the top 4 inches of soil material, when present. The resulting top dressing is rich in native seed and rhizomes allowing a reduced seeding rate. The borders of the right-of-way are mowed in a curvilinear pattern to reduce the straight line effects of landowner cooperation on revegetation. Specifically, following 2 years of monitoring, significant differences in plant cover (0.01« less

Pipeline enhances Norman Wells potential

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Approval of an oil pipeline from halfway down Canada's MacKenzie River Valley at Norman Wells to N. Alberta has raised the potential for development of large reserves along with controversy over native claims. The project involves 2 closely related proposals. One, by Esso Resources, the exploration and production unit of Imperial Oil, will increase oil production from the Norman Wells field from 3000 bpd currently to 25,000 bpd. The other proposal, by Interprovincial Pipeline (N.W) Ltd., calls for construction of an underground pipeline to transport the additional production from Norman Wells to Alberta. The 560-mile, 12-in. pipeline will extend frommore » Norman Wells, which is 90 miles south of the Arctic Circle on the north shore of the Mackenzie River, south to the end of an existing line at Zama in N. Alberta. There will be 3 pumping stations en route. This work also discusses recovery, potential, drilling limitations, the processing plant, positive impact, and further development of the Norman Wells project.« less

78 FR 18331 - East Tennessee Natural Gas, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... Glade Spring Compressor Station and Fordtown Compressor Station. The Kingsport Expansion Project would...; and modifications at the Fordtown Compressor Station. Washington County, Virginia construction of... increase capacity. modifications at the Glade Spring Compressor Station. Washington and Smyth Counties...

21 CFR 868.6250 - Portable air compressor.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Portable air compressor. 868.6250 Section 868.6250...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6250 Portable air compressor. (a) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes, e...

30 CFR 56.13012 - Compressor air intakes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Compressor air intakes. 56.13012 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure that only...

30 CFR 57.13012 - Compressor air intakes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Compressor air intakes. 57.13012 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure...

30 CFR 56.13012 - Compressor air intakes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Compressor air intakes. 56.13012 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure that only...

30 CFR 57.13012 - Compressor air intakes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Compressor air intakes. 57.13012 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure...

30 CFR 56.13012 - Compressor air intakes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Compressor air intakes. 56.13012 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure that only...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, FRANCE COMPRESSOR PRODUCTS EMISSIONS PACKING, PHASE I REPORT

EPA Science Inventory

The report presents results of a Phase I test of emissions packing technology offered by France Compressor Products which is designed to reduce methane leaks from compressor rod packing when a compressor is in a standby and pressurized state. This Phase I test was executed betwee...

30 CFR 56.13012 - Compressor air intakes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure that only... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressor air intakes. 56.13012 Section 56...

30 CFR 57.13012 - Compressor air intakes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressor air intakes. 57.13012 Section 57...

Compressor Modeling for Engine Control and Maintenance

DTIC Science & Technology

2011-07-01

four compressor stages, while the high pressure compressor (HPC) consists of a set of variable pitch inlet guide vanes ( IGVs ) and 12 compressor...bleed valves at stages 5, 14 and 17, along with the variable IGVs and stators within the engine, are used to relieve the pressure and prevent

21 CFR 868.6250 - Portable air compressor.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Portable air compressor. 868.6250 Section 868.6250...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6250 Portable air compressor. (a) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes, e...

21 CFR 868.6250 - Portable air compressor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Portable air compressor. 868.6250 Section 868.6250...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6250 Portable air compressor. (a) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes, e...

Miniature Centrifugal Compressor

NASA Technical Reports Server (NTRS)

Sixsmith, Herbert

1989-01-01

Miniature turbocompressor designed for reliability and long life. Cryogenic system includes compressor, turboexpander, and heat exchanger provides 5 W of refrigeration at 70 K from 150 W input power. Design speed of machine 510,000 rpm. Compressor has gas-lubricated journal bearings and magnetic thrust bearing. When compressor runs no bearing contact and no wear.

40 CFR 86.1868-12 - CO2 credits for improving the efficiency of air conditioning systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Creditvalue (g/mi) Reduced reheat, with externally-controlled, variable-displacement compressor (e.g. a compressor that controls displacement based on temperature setpoint and/or cooling demand of the air...-controlled, fixed-displacement or pneumatic variable displacement compressor (e.g. a compressor that controls...

VPipe: Virtual Pipelining for Scheduling of DAG Stream Query Plans

NASA Astrophysics Data System (ADS)

Wang, Song; Gupta, Chetan; Mehta, Abhay

There are data streams all around us that can be harnessed for tremendous business and personal advantage. For an enterprise-level stream processing system such as CHAOS [1] (Continuous, Heterogeneous Analytic Over Streams), handling of complex query plans with resource constraints is challenging. While several scheduling strategies exist for stream processing, efficient scheduling of complex DAG query plans is still largely unsolved. In this paper, we propose a novel execution scheme for scheduling complex directed acyclic graph (DAG) query plans with meta-data enriched stream tuples. Our solution, called Virtual Pipelined Chain (or VPipe Chain for short), effectively extends the "Chain" pipelining scheduling approach to complex DAG query plans.

The application of magnetic gradiometry and electromagnetic induction at a former radioactive waste disposal site.

PubMed

Rucker, Dale Franklin

2010-04-01

A former radioactive waste disposal site is surveyed with two non-intrusive geophysical techniques, including magnetic gradiometry and electromagnetic induction. Data were gathered over the site by towing the geophysical equipment mounted to a non-electrically conductive and non-magnetic fibre-glass cart. Magnetic gradiometry, which detects the location of ferromagnetic material, including iron and steel, was used to map the existence of a previously unknown buried pipeline formerly used in the delivery of liquid waste to a number of surface disposal trenches and concrete vaults. The existence of a possible pipeline is reinforced by historical engineering drawing and photographs. The electromagnetic induction (EMI) technique was used to map areas of high and low electrical conductivity, which coincide with the magnetic gradiometry data. The EMI also provided information on areas of high electrical conductivity unrelated to a pipeline network. Both data sets demonstrate the usefulness of surface geophysical surveillance techniques to minimize the risk of exposure in the event of future remediation efforts.

A hydrogen energy carrier. Volume 2: Systems analysis

NASA Technical Reports Server (NTRS)

Savage, R. L. (Editor); Blank, L. (Editor); Cady, T. (Editor); Cox, K. (Editor); Murray, R. (Editor); Williams, R. D. (Editor)

1973-01-01

A systems analysis of hydrogen as an energy carrier in the United States indicated that it is feasible to use hydrogen in all energy use areas, except some types of transportation. These use areas are industrial, residential and commercial, and electric power generation. Saturation concept and conservation concept forecasts of future total energy demands were made. Projected costs of producing hydrogen from coal or from nuclear heat combined with thermochemical decomposition of water are in the range $1.00 to $1.50 per million Btu of hydrogen produced. Other methods are estimated to be more costly. The use of hydrogen as a fuel will require the development of large-scale transmission and storage systems. A pipeline system similar to the existing natural gas pipeline system appears practical, if design factors are included to avoid hydrogen environment embrittlement of pipeline metals. Conclusions from the examination of the safety, legal, environmental, economic, political and societal aspects of hydrogen fuel are that a hydrogen energy carrier system would be compatible with American values and the existing energy system.

Hal: an automated pipeline for phylogenetic analyses of genomic data.

PubMed

Robbertse, Barbara; Yoder, Ryan J; Boyd, Alex; Reeves, John; Spatafora, Joseph W

2011-02-07

The rapid increase in genomic and genome-scale data is resulting in unprecedented levels of discrete sequence data available for phylogenetic analyses. Major analytical impasses exist, however, prior to analyzing these data with existing phylogenetic software. Obstacles include the management of large data sets without standardized naming conventions, identification and filtering of orthologous clusters of proteins or genes, and the assembly of alignments of orthologous sequence data into individual and concatenated super alignments. Here we report the production of an automated pipeline, Hal that produces multiple alignments and trees from genomic data. These alignments can be produced by a choice of four alignment programs and analyzed by a variety of phylogenetic programs. In short, the Hal pipeline connects the programs BLASTP, MCL, user specified alignment programs, GBlocks, ProtTest and user specified phylogenetic programs to produce species trees. The script is available at sourceforge (http://sourceforge.net/projects/bio-hal/). The results from an example analysis of Kingdom Fungi are briefly discussed.

Universal route to optimal few- to single-cycle pulse generation in hollow-core fiber compressors.

PubMed

Conejero Jarque, E; San Roman, J; Silva, F; Romero, R; Holgado, W; Gonzalez-Galicia, M A; Alonso, B; Sola, I J; Crespo, H

2018-02-02

Gas-filled hollow-core fiber (HCF) pulse post-compressors generating few- to single-cycle pulses are a key enabling tool for attosecond science and ultrafast spectroscopy. Achieving optimum performance in this regime can be extremely challenging due to the ultra-broad bandwidth of the pulses and the need of an adequate temporal diagnostic. These difficulties have hindered the full exploitation of HCF post-compressors, namely the generation of stable and high-quality near-Fourier-transform-limited pulses. Here we show that, independently of conditions such as the type of gas or the laser system used, there is a universal route to obtain the shortest stable output pulse down to the single-cycle regime. Numerical simulations and experimental measurements performed with the dispersion-scan technique reveal that, in quite general conditions, post-compressed pulses exhibit a residual third-order dispersion intrinsic to optimum nonlinear propagation within the fiber, in agreement with measurements independently performed in several laboratories around the world. The understanding of this effect and its adequate correction, e.g. using simple transparent optical media, enables achieving high-quality post-compressed pulses with only minor changes in existing setups. These optimized sources have impact in many fields of science and technology and should enable new and exciting applications in the few- to single-cycle pulse regime.

Unsteady behavior of leading-edge vortex and diffuser stall in a centrifugal compressor with vaned diffuser

NASA Astrophysics Data System (ADS)

Fujisawa, Nobumichi; Hara, Shotaro; Ohta, Yutaka

2016-02-01

The characteristics of a rotating stall of an impeller and diffuser and the evolution of a vortex generated at the diffuser leading-edge (i.e., the leading-edge vortex (LEV)) in a centrifugal compressor were investigated by experiments and numerical analysis. The results of the experiments revealed that both the impeller and diffuser rotating stalls occurred at 55 and 25 Hz during off-design flow operation. For both, stall cells existed only on the shroud side of the flow passages, which is very close to the source location of the LEV. According to the CFD results, the LEV is made up of multiple vortices. The LEV is a combination of a separated vortex near the leading- edge and a longitudinal vortex generated by the extended tip-leakage flow from the impeller. Therefore, the LEV is generated by the accumulation of vorticity caused by the velocity gradient of the impeller discharge flow. In partial-flow operation, the spanwise extent and the position of the LEV origin are temporarily transmuted. The LEV develops with a drop in the velocity in the diffuser passage and forms a significant blockage within the diffuser passage. Therefore, the LEV may be regarded as being one of the causes of a diffuser stall in a centrifugal compressor.

Chaotic Time Series Analysis Method Developed for Stall Precursor Identification in High-Speed Compressors

NASA Technical Reports Server (NTRS)

1997-01-01

A new technique for rotating stall precursor identification in high-speed compressors has been developed at the NASA Lewis Research Center. This pseudo correlation integral method uses a mathematical algorithm based on chaos theory to identify nonlinear dynamic changes in the compressor. Through a study of four various configurations of a high-speed compressor stage, a multistage compressor rig, and an axi-centrifugal engine test, this algorithm, using only a single pressure sensor, has consistently predicted the onset of rotating stall.

High frequency-heated air turbojet

NASA Technical Reports Server (NTRS)

Miron, J. H. D.

1986-01-01

A description is given of a method to heat air coming from a turbojet compressor to a temperature necessary to produce required expansion without requiring fuel. This is done by high frequency heating, which heats the walls corresponding to the combustion chamber in existing jets, by mounting high frequency coils in them. The current transformer and high frequency generator to be used are discussed.

77 FR 49489 - Oil and Natural Gas Sector: New Source Performance Standards and National Emission Standards for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-16

...This action finalizes the review of new source performance standards for the listed oil and natural gas source category. In this action the EPA revised the new source performance standards for volatile organic compounds from leaking components at onshore natural gas processing plants and new source performance standards for sulfur dioxide emissions from natural gas processing plants. The EPA also established standards for certain oil and gas operations not covered by the existing standards. In addition to the operations covered by the existing standards, the newly established standards will regulate volatile organic compound emissions from gas wells, centrifugal compressors, reciprocating compressors, pneumatic controllers and storage vessels. This action also finalizes the residual risk and technology review for the Oil and Natural Gas Production source category and the Natural Gas Transmission and Storage source category. This action includes revisions to the existing leak detection and repair requirements. In addition, the EPA has established in this action emission limits reflecting maximum achievable control technology for certain currently uncontrolled emission sources in these source categories. This action also includes modification and addition of testing and monitoring and related notification, recordkeeping and reporting requirements, as well as other minor technical revisions to the national emission standards for hazardous air pollutants. This action finalizes revisions to the regulatory provisions related to emissions during periods of startup, shutdown and malfunction.

Analyses of the Integration of Carbon Dioxide Removal Assembly, Compressor, Accumulator and Sabatier Carbon Dioxide Reduction Assembly

NASA Technical Reports Server (NTRS)

Jeng, Frank F.; Lafuse, Sharon; Smith, Frederick D.; Lu, Sao-Dung; Knox, James C.; Campbell, Mellssa L.; Scull, Timothy D.; Green Steve

2010-01-01

A tool has been developed by the Sabatier Team for analyzing/optimizing CO2 removal assembly, CO2 compressor size, its operation logic, water generation from Sabatier, utilization of CO2 from crew metabolic output, and Hz from oxygen generation assembly. Tests had been conducted using CDRA/Simulation compressor set-up at MSFC in 2003. Analysis of test data has validated CO2 desorption rate profile, CO2 compressor performance, CO2 recovery and CO2 vacuum vent in CDRA desorption. Optimizing the compressor size and compressor operation logic for an integrated closed air revitalization system Is being conducted by the Sabatier Team.

Thermal modelling of a dry revolving vane compressor

NASA Astrophysics Data System (ADS)

Ooi, K. T.; Aw, K. T.

2017-08-01

The lubricant used in compressors serves to lubricate, to seal the gaps to reduce internal leakage and to a certain extent, to cool. However, a lubricant free compressor is attractive if lubricants become a source of contaminant, or in areas where the compressor needs be placed under any orientation, such as those in military or portable computing. In this paper, a thermal model for a dry revolving vane compressor is presented. This thermal model sets out to predict the steady-state operating temperatures of the compressor components. The lumped thermal conductance method was employed. The results of the components temperature will be presented and discussed. A high potential for overheating is observed at the shaft bearings.

Practical experience with unstable compressors

NASA Technical Reports Server (NTRS)

Malanoski, S. B.

1980-01-01

Using analytical mathematical modeling techniques for the system components, an attempt is made to gauge the destabilizing effects in a number of compressor designs. In particular the overhung (or cantilevered) compressor designs and the straddle-mounted (or simply supported) compressor designs are examined. Recommendations are made, based on experiences with stable and unstable compressors, which can be used as guides in future designs. High and low pressure compressors which operate well above their fundamental rotor-bearing lateral natural frequencies can suffer from destructive subsynchronous vibration. Usually the elements in the system design which contribute to this vibration, other than the shafting and the bearings, are the seals (both gas labyrinth and oil breakdown bushings) and the aerodynamic components.

Apparatus for the liquefaction of natural gas and methods relating to same

DOEpatents

Wilding, Bruce M [Idaho Falls, ID; Bingham, Dennis N [Idaho Falls, ID; McKellar, Michael G [Idaho Falls, ID; Turner, Terry D [Ammon, ID; Raterman, Kevin T [Idaho Falls, ID; Palmer, Gary L [Shelley, ID; Klingler, Kerry M [Idaho Falls, ID; Vranicar, John J [Concord, CA

2007-05-22

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO.sub.2) clean-up cycle.

Apparatus For The Liquefaaction Of Natural Gas And Methods Relating To Same

DOEpatents

Wilding, Bruce M.; Bingham, Dennis N.; McKellar, Michael G.; Turner, Terry D.; Rateman, Kevin T.; Palmer, Gary L.; Klinger, Kerry M.; Vranicar, John J.

2005-11-08

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO2) clean-up cycle.

Apparatus For The Liquefaaction Of Natural Gas And Methods Relating To Same

DOEpatents

Wilding, Bruce M.; Bingham, Dennis N.; McKellar, Michael G.; Turner, Terry D.; Raterman, Kevin T.; Palmer, Gary L.; Klingler, Kerry M.; Vranicar, John J.

2005-05-03

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO2) clean-up cycle.

Apparatus For The Liquefaaction Of Natural Gas And Methods Relating To Same

DOEpatents

Wilding, Bruce M.; Bingham, Dennis N.; McKellar, Michael G.; Turner, Terry D.; Raterman, Kevin T.; Palmer, Gary L.; Klingler, Kerry M.; Vranicar, John J.

2003-06-24

An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO.sub.2) clean-up cycle.

NOAA Mobile Laboratory Measures Oil and Gas Emissions

NASA Astrophysics Data System (ADS)

Kofler, J. D.; Petron, G.; Dube, W. P.; Edwards, P. M.; Brown, S. S.; Geiger, F.; Patrick, L.; Crepinsek, S.; Chen, H.; Miller, B. R.; Montzka, S. A.; Lang, P. M.; Newberger, T.; Higgs, J. A.; Sweeney, C.; Guenther, D.; Karion, A.; Wolter, S.; Williams, J.; Jordan, A.; Tans, P. P.; Schnell, R. C.

2012-12-01

A van capable of continuous real time measurements of CH4 , CO2, CO, Water Vapor, Ozone, NO, NO2, Volatile Organic Compounds VOCs including aromatics and other traces gases was driven in the oil and gas fields of the Uintah Basin in northeastern Utah. Compressor Stations, processing plants, oil and gas well heads. Separators, condensate tanks, evaporation pond disposal facilities, holding tanks, hydraulic fracturing sites, gas pipelines and more were studied using the van. The mobile measurements provide a powerful tool to get to the source of the emissions and reveal the unique chemical signature of each of the stages and components of oil and gas production as well as the overall basin and background gas concentrations. In addition to a suite of gas analyzers, the van includes a meteorological system (temperature, humidity, and wind speed and direction), GPS tracking, flask sampling system and a batter power system. Aspects of the vans hardware, sampling methods and operations are discussed along with a few highlights of the measurements.

Preliminary Results of Altitude-Wind-Tunnel Investigation of X24C-4B Turbojet Engine. IV - Performance of Modified Compressor. Part 4; Performance of Modified Compressor

NASA Technical Reports Server (NTRS)

Thorman, H. Carl; Dupree, David T.

1947-01-01

The performance of the 11-stage axial-flow compressor, modified to improve the compressor-outlet velocity, in a revised X24C-4B turbojet engine is presented and compared with the performance of the compressor in the original engine. Performance data were obtained from an investigation of the revised engine in the MACA Cleveland altitude wind tunnel. Compressor performance data were obtained for engine operation with four exhaust nozzles of different outlet area at simulated altitudes from 15,OOO to 45,000 feet, simulated flight Mach numbers from 0.24 to 1.07, and engine speeds from 4000 to 12,500 rpm. The data cover a range of corrected engine speeds from 4100 to 13,500 rpm, which correspond to compressor Mach numbers from 0.30 to 1.00.

Development of a turbine-compressor for 10 kW class neon turbo-Brayton refrigerator

NASA Astrophysics Data System (ADS)

Hirai, Hirokazu; Hirokawa, Masaki; Yoshida, Shigeru; Sano, Tomonobu; Ozaki, Shinsuke

2014-01-01

We are developing 10 kW class turbo-Brayton refrigerator whose working fluid is neon gas. Its high pressure value is 1 MPa and its low pressure value is 0.5 MPa. The refrigerator consists of two turbine-compressors and a heat exchanger. The turbine-compressor has a turbo-expander on one side of its shaft and a turbo-compressor on the other side of the shaft. Two turbo-compressors are connected in series and two turbo-expanders are set in parallel. So, all amount of neon gas is compressed by two stages and each half a mount of neon gas is expanded by one stage. Two turbinecompressors are the same machines and development cost and time are minimized. In this stage, we made one prototype turbine-compressor and installed it in a performance test facility. This paper shows details of the turbine-compressor and refrigerator cooling power simulation results.

An evaluation of 1D loss model collections for the off-design performance prediction of automotive turbocharger compressors

NASA Astrophysics Data System (ADS)

Harley, P.; Spence, S.; Early, J.; Filsinger, D.; Dietrich, M.

2013-12-01

Single-zone modelling is used to assess different collections of impeller 1D loss models. Three collections of loss models have been identified in literature, and the background to each of these collections is discussed. Each collection is evaluated using three modern automotive turbocharger style centrifugal compressors; comparisons of performance for each of the collections are made. An empirical data set taken from standard hot gas stand tests for each turbocharger is used as a baseline for comparison. Compressor range is predicted in this study; impeller diffusion ratio is shown to be a useful method of predicting compressor surge in 1D, and choke is predicted using basic compressible flow theory. The compressor designer can use this as a guide to identify the most compatible collection of losses for turbocharger compressor design applications. The analysis indicates the most appropriate collection for the design of automotive turbocharger centrifugal compressors.

Performance characteristics of the Cooper PC-9 centrifugal compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foster, R.E.; Neely, R.F.

1988-06-30

Mathematical performance modeling of the PC-9 centrifugal compressor has been completed. Performance characteristics curves have never been obtained for them in test loops with the same degree of accuracy as for the uprated axial compressors and, consequently, computer modeling of the top cascade and purge cascades has been very difficult and of limited value. This compressor modeling work has been carried out in an attempt to generate data which would more accurately define the compressor's performance and would permit more accurate cascade modeling. A computer code, COMPAL, was used to mathematically model the PC-9 performance with variations in gas composition,more » flow ratios, pressure ratios, speed and temperature. The results of this effort, in the form of graphs, with information about the compressor and the code, are the subject of this report. Compressor characteristic curves are featured. 13 figs.« less

Comprehensive 3D-elastohydrodynamic simulation of hermetic compressor crank drive

NASA Astrophysics Data System (ADS)

Posch, S.; Hopfgartner, J.; Berger, E.; Zuber, B.; Almbauer, R.; Schöllauf, P.

2017-08-01

Mechanical, electrical and thermodynamic losses form the major loss mechanisms of hermetic compressors for refrigeration application. The present work deals with the investigation of the mechanical losses of a hermetic compressor crank drive. Focus is on 3d-elastohydrodynamic (EHD) modelling of the journal bearings, piston-liner contact and piston secondary motion in combination with multi-body and structural dynamics of the crank drive elements. A detailed description of the model development within the commercial software AVL EXCITE Power Unit is given in the work. The model is used to create a comprehensive analysis of the mechanical losses of a hermetic compressor. Further on, a parametric study concerning oil viscosity and compressor speed is carried out which shows the possibilities of the usage of the model in the development process of hermetic compressors for refrigeration application. Additionally, the usage of the results in an overall thermal network for the determination of the thermal compressor behaviour is discussed.

Algorithm for Controlling a Centrifugal Compressor

NASA Technical Reports Server (NTRS)

Benedict, Scott M.

2004-01-01

An algorithm has been developed for controlling a centrifugal compressor that serves as the prime mover in a heatpump system. Experimental studies have shown that the operating conditions for maximum compressor efficiency are close to the boundary beyond which surge occurs. Compressor surge is a destructive condition in which there are instantaneous reversals of flow associated with a high outlet-to-inlet pressure differential. For a given cooling load, the algorithm sets the compressor speed at the lowest possible value while adjusting the inlet guide vane angle and diffuser vane angle to maximize efficiency, subject to an overriding requirement to prevent surge. The onset of surge is detected via the onset of oscillations of the electric current supplied to the compressor motor, associated with surge-induced oscillations of the torque exerted by and on the compressor rotor. The algorithm can be implemented in any of several computer languages.

Study on the CO2 electric driven fixed swash plate type compressor for eco-friendly vehicles

NASA Astrophysics Data System (ADS)

Nam, Donglim; Kim, Kitae; Lee, Jehie; Kwon, Yunki; Lee, Geonho

2017-08-01

The purpose of this study is to experiment and to performance analysis about the electric-driven fixed swash plate compressor using alternate refrigerant(R744). Comprehensive simulation model for an electric driven compressor using CO2 for eco-friendly vehicle is presented. This model consists of compression model and dynamic model. The compression model included valve dynamics, leakage, and heat transfer models. And the dynamic model included frictional loss between piston ring and cylinder wall, frictional loss between shoe and swash plate, frictional loss of bearings, and electric efficiency. Especially, because the efficiency of an electric parts(motor and inverter) in the compressor affects the loss of the compressor, the dynamo test was performed. We made the designed compressor, and tested the performance of the compressor about the variety pressure conditions. Also we compared the performance analysis result and performance test result.

Performance analysis of underwater pump for water-air dual-use engine

NASA Astrophysics Data System (ADS)

Xia, Jun; Wang, Yun; Chen, Yu

2017-10-01

To make water-air dual-use engine work both in air and under water, the compressor of the engine should not only meet the requirements of air flight, but also must have the ability to work underwater. To verify the performance of the compressor when the water-air dual-use engine underwater propulsion mode, the underwater pumping water model of the air compressor is simulated by commercial CFD software, and the flow field analysis is carried out. The results show that conventional air compressors have a certain ability to work in the water environment, however, the blade has a great influence on the flow, and the compressor structure also affects the pump performance. Compressor can initially take into account the two modes of water and air. In order to obtain better performance, the structure of the compressor needs further improvement and optimization.

46 CFR 197.310 - Air compressor system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Air compressor system. 197.310 Section 197.310 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.310 Air compressor system. A compressor used to supply breathing air to a diver must have— (a) A volume tank that is— (1) Built and stamped in...

46 CFR 197.310 - Air compressor system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Air compressor system. 197.310 Section 197.310 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.310 Air compressor system. A compressor used to supply breathing air to a diver must have— (a) A volume tank that is— (1) Built and stamped in...

46 CFR 197.310 - Air compressor system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Air compressor system. 197.310 Section 197.310 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.310 Air compressor system. A compressor used to supply breathing air to a diver must have— (a) A volume tank that is— (1) Built and stamped in...

46 CFR 197.310 - Air compressor system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Air compressor system. 197.310 Section 197.310 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.310 Air compressor system. A compressor used to supply breathing air to a diver must have— (a) A volume tank that is— (1) Built and stamped in...

VIEW OF COMPRESSOR ROOM AT GROUND LEVEL SHOWING COMPRESSOR EQUIPMENT. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF COMPRESSOR ROOM AT GROUND LEVEL SHOWING COMPRESSOR EQUIPMENT. VIEW FACING SOUTH - U.S. Naval Base, Pearl Harbor, Ford Island Polaris Missile Lab & U.S. Fleet Ballistic Missile Submarine Training Center, Between Lexington Boulvevard and the sea plane ramps on the southwest side of Ford Island, Pearl City, Honolulu County, HI

75 FR 61461 - Central New York Oil and Gas Company, LLC; Notice of Availability of the Environmental Assessment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-05

... electric-driven 13,400-horsepower (hp) centrifugal compressor; One new compressor station in Bradford County, Pennsylvania (the NS2 Compressor Station) with an electric-driven 15,300-hp centrifugal... construct, operate, and maintain two new compressor stations in Tioga County, New York and Bradford County...

30 CFR 72.501 - Emission limits for nonpermissible heavy-duty diesel-powered equipment, generators and compressors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... diesel-powered equipment, generators and compressors. 72.501 Section 72.501 Mineral Resources MINE SAFETY... nonpermissible heavy-duty diesel-powered equipment, generators and compressors. (a) Each piece of nonpermissible heavy-duty diesel-powered equipment (as defined by § 75.1908(a) of this part), generator or compressor...

30 CFR 72.501 - Emission limits for nonpermissible heavy-duty diesel-powered equipment, generators and compressors.

Code of Federal Regulations, 2011 CFR

2011-07-01

... diesel-powered equipment, generators and compressors. 72.501 Section 72.501 Mineral Resources MINE SAFETY... nonpermissible heavy-duty diesel-powered equipment, generators and compressors. (a) Each piece of nonpermissible heavy-duty diesel-powered equipment (as defined by § 75.1908(a) of this part), generator or compressor...

Methodology for the determination of criticality codes and recertification intervals for Tank Mounted Air Compressors (TMAC) and Base Mounted Air Compressors (BMAC)

NASA Technical Reports Server (NTRS)

Hargrove, William T.

1991-01-01

This methodology is used to determine inspection procedures and intervals for components contained within tank mounted air compressor systems (TMAC) and base mounted air compressor systems (BMAC). These systems are included in the Pressure Vessel and System Recertification inventory at GSFC.

A Parallel Pipelined Renderer for the Time-Varying Volume Data

NASA Technical Reports Server (NTRS)

Chiueh, Tzi-Cker; Ma, Kwan-Liu

1997-01-01

This paper presents a strategy for efficiently rendering time-varying volume data sets on a distributed-memory parallel computer. Time-varying volume data take large storage space and visualizing them requires reading large files continuously or periodically throughout the course of the visualization process. Instead of using all the processors to collectively render one volume at a time, a pipelined rendering process is formed by partitioning processors into groups to render multiple volumes concurrently. In this way, the overall rendering time may be greatly reduced because the pipelined rendering tasks are overlapped with the I/O required to load each volume into a group of processors; moreover, parallelization overhead may be reduced as a result of partitioning the processors. We modify an existing parallel volume renderer to exploit various levels of rendering parallelism and to study how the partitioning of processors may lead to optimal rendering performance. Two factors which are important to the overall execution time are re-source utilization efficiency and pipeline startup latency. The optimal partitioning configuration is the one that balances these two factors. Tests on Intel Paragon computers show that in general optimal partitionings do exist for a given rendering task and result in 40-50% saving in overall rendering time.

East Spar: Alliance approach for offshore gasfield development

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-04-01

East spar is a gas/condensate field 25 miles west of Barrow Island, offshore Western Australia. Proved plus probable reserves at the time of development were estimated at 430 Bcf gas and 28 million bbl of condensate. The field was discovered in early 1993 when the Western Australia gas market was deregulated and the concept of a gas pipeline to the gold fields was proposed. This created a window of opportunity for East Spar, but only if plans could be established quickly. A base-case development plan was established to support gas marketing while alternative plans could be developed in parallel. Themore » completed East Spar facilities comprise two subsea wells, a subsea gathering system, and a multiphase (gas/condensate/water) pipeline to new gas-processing facilities. The subsea facilities are controlled through a navigation, communication, and control (NCC) buoy. The control room and gas-processing plant are 39 miles east of the field on Varanus Island. Sales gas is exported through a pre-existing gas-sales pipeline to the Dampier-Bunbury and Goldfields Gas Transmission pipelines. Condensate is stored in and exported by use of pre-existing facilities on Varanus Island. Field development from approval to first production took 22 months. The paper describes its field development.« less

IN13B-1660: Analytics and Visualization Pipelines for Big Data on the NASA Earth Exchange (NEX) and OpenNEX

NASA Technical Reports Server (NTRS)

Chaudhary, Aashish; Votava, Petr; Nemani, Ramakrishna R.; Michaelis, Andrew; Kotfila, Chris

2016-01-01

We are developing capabilities for an integrated petabyte-scale Earth science collaborative analysis and visualization environment. The ultimate goal is to deploy this environment within the NASA Earth Exchange (NEX) and OpenNEX in order to enhance existing science data production pipelines in both high-performance computing (HPC) and cloud environments. Bridging of HPC and cloud is a fairly new concept under active research and this system significantly enhances the ability of the scientific community to accelerate analysis and visualization of Earth science data from NASA missions, model outputs and other sources. We have developed a web-based system that seamlessly interfaces with both high-performance computing (HPC) and cloud environments, providing tools that enable science teams to develop and deploy large-scale analysis, visualization and QA pipelines of both the production process and the data products, and enable sharing results with the community. Our project is developed in several stages each addressing separate challenge - workflow integration, parallel execution in either cloud or HPC environments and big-data analytics or visualization. This work benefits a number of existing and upcoming projects supported by NEX, such as the Web Enabled Landsat Data (WELD), where we are developing a new QA pipeline for the 25PB system.

Analytics and Visualization Pipelines for Big ­Data on the NASA Earth Exchange (NEX) and OpenNEX

NASA Astrophysics Data System (ADS)

Chaudhary, A.; Votava, P.; Nemani, R. R.; Michaelis, A.; Kotfila, C.

2016-12-01

We are developing capabilities for an integrated petabyte-scale Earth science collaborative analysis and visualization environment. The ultimate goal is to deploy this environment within the NASA Earth Exchange (NEX) and OpenNEX in order to enhance existing science data production pipelines in both high-performance computing (HPC) and cloud environments. Bridging of HPC and cloud is a fairly new concept under active research and this system significantly enhances the ability of the scientific community to accelerate analysis and visualization of Earth science data from NASA missions, model outputs and other sources. We have developed a web-based system that seamlessly interfaces with both high-performance computing (HPC) and cloud environments, providing tools that enable science teams to develop and deploy large-scale analysis, visualization and QA pipelines of both the production process and the data products, and enable sharing results with the community. Our project is developed in several stages each addressing separate challenge - workflow integration, parallel execution in either cloud or HPC environments and big-data analytics or visualization. This work benefits a number of existing and upcoming projects supported by NEX, such as the Web Enabled Landsat Data (WELD), where we are developing a new QA pipeline for the 25PB system.

Sound reduction of air compressors using a systematic approach

NASA Astrophysics Data System (ADS)

Moylan, Justin Tharp

The noise emitted by portable electric air compressors can often be a nuisance or potentially hazardous to the operator or others nearby. Therefore, reducing the noise of these air compressors is desired. This research focuses on compressors with a reciprocating piston design as this is the most common type of pump design for portable compressors. An experimental setup was developed to measure the sound and vibration of the air compressors, including testing inside a semi-anechoic chamber. The design of a quiet air compressor was performed in four stages: 1) Teardown and benchmarking of air compressors, 2) Identification and isolation of noise sources, 3) Development of individual means to quiet noise sources, 4) Selection and testing of integrated solutions. The systematic approach and results for each of these stages will be discussed. Two redesigned solutions were developed and measured to be approximately 65% quieter than the previous unmodified compressor. An additional analysis was performed on the solutions selected by the participants involved in the selection process. This analysis involved determining which of the design criteria each participant considered most important when selecting solutions. The results from each participant were then compared to their educational background and experience and correlations were identified. The correlations discovered suggest that educational background and experience may be key determinants for the preference models developed.

Method for evaluating the reliability of compressor impeller of turbocharger for vehicle application in plateau area

NASA Astrophysics Data System (ADS)

Wang, Zheng; Wang, Zengquan; Wang, A.-na; Zhuang, Li; Wang, Jinwei

2016-10-01

As turbocharging diesel engines for vehicle application are applied in plateau area, the environmental adaptability of engines has drawn more attention. For the environmental adaptability problem of turbocharging diesel engines for vehicle application, the present studies almost focus on the optimization of performance match between turbocharger and engine, and the reliability problem of turbocharger is almost ignored. The reliability problem of compressor impeller of turbocharger for vehicle application when diesel engines operate in plateau area is studied. Firstly, the rule that the rotational speed of turbocharger changes with the altitude height is presented, and the potential failure modes of compressor impeller are analyzed. Then, the failure behavior models of compressor impeller are built, and the reliability models of compressor impeller operating in plateau area are developed. Finally, the rule that the reliability of compressor impeller changes with the altitude height is studied, the measurements for improving the reliability of the compressor impellers of turbocharger operating in plateau area are given. The results indicate that when the operating speed of diesel engine is certain, the rotational speed of turbocharger increases with the increase of altitude height, and the failure risk of compressor impeller with the failure modes of hub fatigue and blade resonance increases. The reliability of compressor impeller decreases with the increase of altitude height, and it also decreases as the increase of number of the mission profile cycle of engine. The method proposed can not only be used to evaluating the reliability of compressor impeller when diesel engines operate in plateau area but also be applied to direct the structural optimization of compressor impeller.

A Cabin Air Separator for EVA Oxygen

NASA Technical Reports Server (NTRS)

Graf, John C.

2011-01-01

Presently, the Extra-Vehicular Activities (EVAs) conducted from the Quest Joint Airlock on the International Space Station use high pressure, high purity oxygen that is delivered to the Space Station by the Space Shuttle. When the Space Shuttle retires, a new method of delivering high pressure, high purity oxygen to the High Pressure Gas Tanks (HPGTs) is needed. One method is to use a cabin air separator to sweep oxygen from the cabin air, generate a low pressure/high purity oxygen stream, and compress the oxygen with a multistage mechanical compressor. A main advantage to this type of system is that the existing low pressure oxygen supply infrastructure can be used as the source of cabin oxygen. ISS has two water electrolysis systems that deliver low pressure oxygen to the cabin, as well as chlorate candles and compressed gas tanks on cargo vehicles. Each of these systems can feed low pressure oxygen into the cabin, and any low pressure oxygen source can be used as an on-board source of oxygen. Three different oxygen separator systems were evaluated, and a two stage Pressure Swing Adsorption system was selected for reasons of technical maturity. Two different compressor designs were subjected to long term testing, and the compressor with better life performance and more favorable oxygen safety characteristics was selected. These technologies have been used as the basis of a design for a flight system located in Equipment Lock, and taken to Preliminary Design Review level of maturity. This paper describes the Cabin Air Separator for EVA Oxygen (CASEO) concept, describes the separator and compressor technology trades, highlights key technology risks, and describes the flight hardware concept as presented at Preliminary Design Review (PDR)

Comparative assessment of water use and environmental implications of coal slurry pipelines

USGS Publications Warehouse

Palmer, Richard N.; James II, I. C.; Hirsch, R.M.

1977-01-01

With other studies conducted by the U.S. Geological Survey of water use in the conversion and transportation of the West 's coal, an analysis of water use and environmental implications of coal-slurry pipeline transport is presented. Simulations of a hypothetical slurry pipeline of 1000-mile length transporting 12.5 million tons per year indicate that pipeline costs and energy requirements are quite sensitive to the coal-to-water ratio. For realistic water prices, the optimal ratio will not vary far from the 50/50 ratio by weight. In comparison to other methods of energy conversion and transport, coal-slurry pipeline utilize about 1/3 the amount of water required for coal gasification, and about 1/5 the amount required for on-site electrical generation. An analysis of net energy output from operating alternative energy transportation systems for the assumed conditions indicates that both slurry pipeline and rail shipment require approximately 4.5 percent of the potential electrical energy output of the coal transported, and high-voltage, direct-current transportation requires approximately 6.5 percent. The environmental impacts of the different transports options are so substantially different that a common basis for comparison does not exist. (Woodard-USGS)

High-throughput bioinformatics with the Cyrille2 pipeline system

PubMed Central

Fiers, Mark WEJ; van der Burgt, Ate; Datema, Erwin; de Groot, Joost CW; van Ham, Roeland CHJ

2008-01-01

Background Modern omics research involves the application of high-throughput technologies that generate vast volumes of data. These data need to be pre-processed, analyzed and integrated with existing knowledge through the use of diverse sets of software tools, models and databases. The analyses are often interdependent and chained together to form complex workflows or pipelines. Given the volume of the data used and the multitude of computational resources available, specialized pipeline software is required to make high-throughput analysis of large-scale omics datasets feasible. Results We have developed a generic pipeline system called Cyrille2. The system is modular in design and consists of three functionally distinct parts: 1) a web based, graphical user interface (GUI) that enables a pipeline operator to manage the system; 2) the Scheduler, which forms the functional core of the system and which tracks what data enters the system and determines what jobs must be scheduled for execution, and; 3) the Executor, which searches for scheduled jobs and executes these on a compute cluster. Conclusion The Cyrille2 system is an extensible, modular system, implementing the stated requirements. Cyrille2 enables easy creation and execution of high throughput, flexible bioinformatics pipelines. PMID:18269742

High Energy Vibration for Gas Piping

NASA Astrophysics Data System (ADS)

Lee, Gary Y. H.; Chan, K. B.; Lee, Aylwin Y. S.; Jia, ShengXiang

2017-07-01

In September 2016, a gas compressor in offshore Sarawak has its rotor changed out. Prior to this change-out, pipe vibration study was carried-out by the project team to evaluate any potential high energy pipe vibration problems at the compressor’s existing relief valve downstream pipes due to process condition changes after rotor change out. This paper covers high frequency acoustic excitation (HFAE) vibration also known as acoustic induced vibration (AIV) study and discusses detailed methodologies as a companion to the Energy Institute Guidelines for the avoidance of vibration induced fatigue failure, which is a common industry practice to assess and mitigate for AIV induced fatigue failure. Such detailed theoretical studies can help to minimize or totally avoid physical pipe modification, leading to reduce offshore plant shutdown days to plant shutdowns only being required to accommodate gas compressor upgrades, reducing cost without compromising process safety.

Centrifugal reciprocating compressor

NASA Technical Reports Server (NTRS)

High, W. H.

1980-01-01

Efficient compressor uses centrifugal force to compress gas. System incorporates two coupled dc motors, each driving separate centrifugal reciprocating-compressor assembly. Motors are synchronized to accelerate and decelerate alternately.

Development of a High Efficiency Compressor/Expander for an Air Cycle Air Conditioning System.

DTIC Science & Technology

1982-11-15

bearing, lb PHUB - Hub pressure (initial guess), psia RLG - Rotor length 1 ’B-2 RPM - Rotational speed, RPM R - Gas constant, lb -ft/lb - R CP - Specific...Compressor discharge port pressure ratio (PCD/PC2).:- CDP - Compressor pressure change, PCD-PCl PHUB - Pressure in compressor hub (acting on base of vanes

R-189 (C-620) air compressor control logic software documentation. Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter, K.E.

1995-06-08

This relates to FFTF plant air compressors. Purpose of this document is to provide an updated Computer Software Description for the software to be used on R-189 (C-620-C) air compressor programmable controllers. Logic software design changes were required to allow automatic starting of a compressor that had not been previously started.

Fast 4-2 Compressor of Booth Multiplier Circuits for High-Speed RISC Processor

NASA Astrophysics Data System (ADS)

Yuan, S. C.

2008-11-01

We use different XOR circuits to optimize the XOR structure 4-2 compressor, and design the transmission gates(TG) 4-2 compressor use single to dual rail circuit configurations. The maximum propagation delay, the power consumption and the layout area of the designed 4-2 compressors are simulated with 0.35μm and 0.25μm CMOS process parameters and compared with results of the synthesized 4-2 circuits, and show that the designed 4-2 compressors are faster and area smaller than the synthesized one.

Determination of Pressure Fluctuations in Rotor Bundle of Centrifugal Compressor at Critical Conditions of Operation

NASA Astrophysics Data System (ADS)

Levashov, V. A.; Lyubchenko, K. Yu

2017-08-01

This article describes the physical processes that occur in the stage flow part of the compressor while it is operating and can create conditions for the occurrence of forced vibrations, which in turn can lead to the destruction of the impellers. Critical conditions of compressor operation are determined. To understand that critical condition of operation is cause of the destruction of the impellers, transient CFD analysis was carried for test stage of compressor. The obtained pressure fluctuation amplitudes allow to evaluate the critical conditions of compressor operation.

Possibility of Thermomechanical Compressor Application in Desalination Plants

NASA Astrophysics Data System (ADS)

Blagin, E. V.; Shimanov, A. A.; Uglanov, D. A.; Korneev, S. S.

2018-01-01

This article deals with estimation of thermocompressor operating possibility in desalination plant with mechanical vapour compressor. In this plant thermocompressor is used instead of commonly used centrifugal compressor. Preliminary analysis shows that such plant is able to operate, however, power consumption is 3.5-6.5 higher in comparison with traditional MVC plant. In turn, utilization of thermocompressor allows avoiding usual high-frequency drive of centrifugal compressor. Drives with frequency of 50 Hz are enough for thermocompressor when centrifugal compressor requires drives with frequency up to 500 Hz and higher. Approximate thermocompressor dimensions are estimated.

NASA Environmentally Responsible Aviation High Overall Pressure Ratio Compressor Research Pre-Test CFD

NASA Technical Reports Server (NTRS)

Celestina, Mark L.; Fabian, John C.; Kulkarni, Sameer

2012-01-01

This paper describes a collaborative and cost-shared approach to reducing fuel burn under the NASA Environmentally Responsible Aviation project. NASA and General Electric (GE) Aviation are working together aa an integrated team to obtain compressor aerodynamic data that is mutually beneficial to both NASA and GE Aviation. The objective of the High OPR Compressor Task is to test a single stage then two stages of an advanced GE core compressor using state-of-the-art research instrumentation to investigate the loss mechanisms and interaction effects of embedded transonic highly-loaded compressor stages. This paper presents preliminary results from NASA's in-house multistage computational code, APNASA, in preparation for this advanced transonic compressor rig test.

A computational genomics pipeline for prokaryotic sequencing projects

PubMed Central

Kislyuk, Andrey O.; Katz, Lee S.; Agrawal, Sonia; Hagen, Matthew S.; Conley, Andrew B.; Jayaraman, Pushkala; Nelakuditi, Viswateja; Humphrey, Jay C.; Sammons, Scott A.; Govil, Dhwani; Mair, Raydel D.; Tatti, Kathleen M.; Tondella, Maria L.; Harcourt, Brian H.; Mayer, Leonard W.; Jordan, I. King

2010-01-01

Motivation: New sequencing technologies have accelerated research on prokaryotic genomes and have made genome sequencing operations outside major genome sequencing centers routine. However, no off-the-shelf solution exists for the combined assembly, gene prediction, genome annotation and data presentation necessary to interpret sequencing data. The resulting requirement to invest significant resources into custom informatics support for genome sequencing projects remains a major impediment to the accessibility of high-throughput sequence data. Results: We present a self-contained, automated high-throughput open source genome sequencing and computational genomics pipeline suitable for prokaryotic sequencing projects. The pipeline has been used at the Georgia Institute of Technology and the Centers for Disease Control and Prevention for the analysis of Neisseria meningitidis and Bordetella bronchiseptica genomes. The pipeline is capable of enhanced or manually assisted reference-based assembly using multiple assemblers and modes; gene predictor combining; and functional annotation of genes and gene products. Because every component of the pipeline is executed on a local machine with no need to access resources over the Internet, the pipeline is suitable for projects of a sensitive nature. Annotation of virulence-related features makes the pipeline particularly useful for projects working with pathogenic prokaryotes. Availability and implementation: The pipeline is licensed under the open-source GNU General Public License and available at the Georgia Tech Neisseria Base (http://nbase.biology.gatech.edu/). The pipeline is implemented with a combination of Perl, Bourne Shell and MySQL and is compatible with Linux and other Unix systems. Contact: king.jordan@biology.gatech.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20519285

Optimizing power cylinder lubrication on a large bore natural gas engine

NASA Astrophysics Data System (ADS)

Luedeman, Matthew R.

More than 6000 integral compressors, located along America's natural gas pipelines, pump natural gas across the United States. These compressors are powered by 2-stroke, large bore natural gas burning engines. Lowering the operating costs, reducing the emissions, and ensuring that these engines remain compliant with future emission regulations are the drivers for this study. Substantial research has focused on optimizing efficiency and reducing the fuel derived emissions on this class of engine. However, significantly less research has focused on the effect and reduction of lubricating oil derived emissions. This study evaluates the impact of power cylinder lubricating oil on overall engine emissions with an emphasis on reducing oxidation catalyst poisoning. A traditional power cylinder lubricator was analyzed; power cylinder lubricating oil was found to significantly impact exhaust emissions. Lubricating oil was identified as the primary contributor of particulate matter production in a large bore natural gas engine. The particulate matter was determined to be primarily organic carbon, and most likely direct oil carryover of small oil droplets. The particulate matter production equated to 25% of the injected oil at a nominal power cylinder lubrication rate. In addition, power cylinder friction is considered the primary contributor to friction loss in the internal combustion engine. This study investigates the potential for optimizing power cylinder lubrication by controlling power cylinder injection to occur at the optimal time in the piston cycle. By injecting oil directly into the ring pack, it is believed that emissions, catalyst poisoning, friction, and wear can all be reduced. This report outlines the design and theory of two electronically controlled lubrication systems. Experimental results and evaluation of one of the systems is included.

TOKAMAK-15 modernization and an analysis of cryogenic system operation for the period from 1988 to 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duzhev, V.E.; Zhulkin, V.F.; Ugrovatov, A.E.

1996-12-31

The T-15 cryogenics system has been designed for cooling down, cryostatting, warming up of superconducting, cryoresistive and cryogenics T-15 objects. Maintenance of the cryogenics system has been on going since 1988. For the mentioned period, in the cryogenics T-15 system. The capacity of screw compressor was increased from 0.181 kg/s to 0.236 kg/s (third stage compressors with increased capacity were developed and manufactured), their reliability was also enhanced. The capacity of liquefiers was increased from 0.0833 - 0.0972 L/s (300-350 L/h) to 0.222 L/s (800 L/h) due to replacement of turboexpanders by more effective ones and due to introduction ofmore » an end-stage turboexpander into maintenance. The heat influxes to the cryogenics pipelines were reduced by 50%. For the same period some technological regimes of cryogenics system have been developed to produce the maximal output of cold. The cooling down from 110 K to 15 K is done, when one or two liquefiers are in operation under refrigerating conditions with the reverse flow splitting. The further cooling is performed under joint operation of two liquefiers; one of them operates in the liquefying mode, another, in the refrigerating one with excess reverse flow. A change in the operating conditions was necessary because of the impossibility of regulating the distribution of the reverse helium flow between two liquefiers at the temperature below 15K. The main regime at the level of 4.5 K is a two-loop operating diagram, when one liquefier and a passive refrigerator with excessive reverse flow are in operation, the refrigerating capacity is about 3 kW.« less

A new segmentation strategy for processing magnetic anomaly detection data of shallow depth ferromagnetic pipeline

NASA Astrophysics Data System (ADS)

Feng, Shuo; Liu, Dejun; Cheng, Xing; Fang, Huafeng; Li, Caifang

2017-04-01

Magnetic anomalies produced by underground ferromagnetic pipelines because of the polarization of earth's magnetic field are used to obtain the information on the location, buried depth and other parameters of pipelines. In order to achieve a fast inversion and interpretation of measured data, it is necessary to develop a fast and stable forward method. Magnetic dipole reconstruction (MDR), as a kind of integration numerical method, is well suited for simulating a thin pipeline anomaly. In MDR the pipeline model must be cut into small magnetic dipoles through different segmentation methods. The segmentation method has an impact on the stability and speed of forward calculation. Rapid and accurate simulation of deep-buried pipelines has been achieved by exciting segmentation method. However, in practical measurement, the depth of underground pipe is uncertain. When it comes to the shallow-buried pipeline, the present segmentation may generate significant errors. This paper aims at solving this problem in three stages. First, the cause of inaccuracy is analyzed by simulation experiment. Secondly, new variable interval section segmentation is proposed based on the existing segmentation. It can help MDR method to obtain simulation results in a fast way under the premise of ensuring the accuracy of different depth models. Finally, the measured data is inversed based on new segmentation method. The result proves that the inversion based on the new segmentation can achieve fast and accurate inversion of depth parameters of underground pipes without being limited by pipeline depth.

Performance of the active sidewall boundary-layer removal system for the Langley 0.3-meter Transonic Cryogenic Tunnel

NASA Technical Reports Server (NTRS)

Balakrishna, S.; Kilgore, W. Allen; Murthy, A. V.

1989-01-01

A performance evaluation of an active sidewall boundary-layer removal system for the Langley 0.3-m Transonic Cryogenic Tunnel (TCT) was evaluated in 1988. This system uses a compressor and two throttling digital valves to control the boundary-layer mass flow removal from the tunnel. The compressor operates near the maximum pressure ratio for all conditions. The system uses a surge prevention and flow recirculation scheme. A microprocessor based controller is used to provide the necessary mass flow and compressor pressure ratio control. Initial tests on the system indicated problems in realizing smooth mass flow control while running the compressor at high speed and high pressure ratios. An alternate method has been conceived to realize boundary-layer mass flow control which avoids the recirculation of the compressor mass flow and operation near the compressor surge point. This scheme is based on varying the speed of the compressor for a sufficient pressure ratio to provide needed mass flow removal. The system has a mass flow removal capability of about 10 percent of test section flow at M = 0.3 and 4 percent at M = 0.8. The system performance has been evaluated in the form of the compressor map, and compressor tunnel interface characteristics covering most of the 0.3-m TCT operational envelope.

Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

DOE PAGES

Knudsen, P.; Ganni, V.; Dixon, K.; ...

2015-08-10

Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore » be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knudsen, P.; Ganni, V.; Dixon, K.

Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore » be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

Axial and Centrifugal Compressor Mean Line Flow Analysis Method

NASA Technical Reports Server (NTRS)

Veres, Joseph P.

2009-01-01

This paper describes a method to estimate key aerodynamic parameters of single and multistage axial and centrifugal compressors. This mean-line compressor code COMDES provides the capability of sizing single and multistage compressors quickly during the conceptual design process. Based on the compressible fluid flow equations and the Euler equation, the code can estimate rotor inlet and exit blade angles when run in the design mode. The design point rotor efficiency and stator losses are inputs to the code, and are modeled at off design. When run in the off-design analysis mode, it can be used to generate performance maps based on simple models for losses due to rotor incidence and inlet guide vane reset angle. The code can provide an improved understanding of basic aerodynamic parameters such as diffusion factor, loading levels and incidence, when matching multistage compressor blade rows at design and at part-speed operation. Rotor loading levels and relative velocity ratio are correlated to the onset of compressor surge. NASA Stage 37 and the three-stage NASA 74-A axial compressors were analyzed and the results compared to test data. The code has been used to generate the performance map for the NASA 76-B three-stage axial compressor featuring variable geometry. The compressor stages were aerodynamically matched at off-design speeds by adjusting the variable inlet guide vane and variable stator geometry angles to control the rotor diffusion factor and incidence angles.

Elastohydrodynamic Lubrication with Polyolester Lubricants and HFC Refrigerants, Final Report, Volume 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gunsel, Selda; Pozebanchuk, Michael

1999-04-01

Lubrication properties of refrigeration lubricants were investigated in high pressure nonconforming contacts under different conditions of temperature, rolling speed, and refrigerant concentration. The program was based upon the recognition that the lubrication regime in refrigeration compressors is generally elastohydrodynamic or hydrodynamic, as determined by the operating conditions of the compressor and the properties of the lubricant. Depending on the compressor design, elastohydrodynamic lubrication conditions exist in many rolling and sliding elements of refrigeration compressors such as roller element bearings, gears, and rotors. The formation of an elastohydrodynamic film separating rubbing surfaces is important in preventing the wear and failure ofmore » compressor elements. It is, therefore, important to predict the elastohydrodynamic (EHD) performance of lubricants under realistic tribocontact renditions. This is, however, difficult as the lubricant properties that control film formation are critically dependent upon pressure and shear, and cannot be evaluated using conventional laboratory instruments. In this study, the elastohydrodynamic behavior of refrigeration lubricants with and without the presence of refrigerants was investigated using the ultrathin film EHD interferometry technique. This technique enables very thin films, down to less than 5 nm, to be measured accurately within an EHD contact under realistic conditions of temperature, shear, and pressure. The technique was adapted to the study of lubricant refrigerant mixtures. Film thickness measurements were obtained on refrigeration lubricants as a function of speed, temperature, and refrigerant concentration. The effects of lubricant viscosity, temperature, rolling speed, and refrigerant concentration on EHD film formation were investigated. From the film thickness measurements, effective pressure-viscosity coefficients were calculated. The lubricants studied in this project included two naphthenic mineral oils (NMO), four polyolesters (POE), and two polyvinyl ether (PVE) fluids. These fluids represented viscosity grades of ISO 32 and ISO 68 and are shown in a table. Refrigerants studied included R-22, R-134a, and R-410A. Film thickness measurements were conducted at 23 C, 45 C, and 65 C with refrigerant concentrations ranging from zero to 60% by weight.« less

Investigation of H2 Diaphragm Compressors to Enable Low-Cost Long-Life Operation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rohatgi, Aashish; Johnson, Kenneth I.

2013-12-01

This is a “short” annual report to DOE Fuel Cell Technology Office describing the research on modeling and materials analysis of diaphragms in a diaphragm-type hydrogen compressor. The compressor design details and diaphragm materials were provided by PDC Machines, Inc., a commercial manufacturer of diaphragm-type hydrogen compressors that PNNL is partnering with in this project

Experimental Investigation of Diffuser Hub Injection to Improve Centrifugal Compressor Stability

NASA Technical Reports Server (NTRS)

Skoch, Gary J.

2004-01-01

Results from a series of experiments to investigate whether centrifugal compressor stability could be improved by injecting air through the diffuser hub surface are reported. The research was conducted in a 4:1 pressure ratio centrifugal compressor configured with a vane-island diffuser. Injector nozzles were located just upstream of the leading edge of the diffuser vanes. Nozzle orientations were set to produce injected streams angled at 8, 0 and +8 degrees relative to the vane mean camber line. Several injection flow rates were tested using both an external air supply and recirculation from the diffuser exit. Compressor flow range did not improve at any injection flow rate that was tested. Compressor flow range did improve slightly at zero injection due to the flow resistance created by injector openings on the hub surface. Leading edge loading and semi-vaneless space diffusion showed trends similar to those reported earlier from shroud surface experiments that did improve compressor flow range. Opposite trends are seen for hub injection cases where compressor flow range decreased. The hub injection data further explain the range improvement provided by shroud-side injection and suggest that different hub-side techniques may produce range improvement in centrifugal compressors.

The results of pre-design studies on the development of a new design of gas turbine compressor package of GPA-C-16 type

NASA Astrophysics Data System (ADS)

Smirnov, A. V.; Chobenko, V. M.; Shcherbakov, O. M.; Ushakov, S. M.; Parafiynyk, V. P.; Sereda, R. M.

2017-08-01

The article summarizes the results of analysis of data concerning the operation of turbocompressor packages at compressor stations for the natural gas transmission system of Ukraine. The basic requirements for gas turbine compressor packages used for modernization and reconstruction of compressor stations are considered. Using a 16 MW gas turbine package GPA-C-16S/76-1,44M1 as an example, the results of pre-design studies and some technical solutions that improve the energy efficiency of gas turbine compressor packages and their reliability, as well as its environmental performance are given. In particular, the article deals with the matching of performance characteristics of a centrifugal compressor (hereinafter compressor) and gas turbine drive to reduce fuel gas consumption; as well as application of energy efficient technologies, in particular, exhaust gas heat recovery units and gas-oil heat exchangers in turbocompressor packages oil system; as well as reducing emissions of carbon monoxide into the atmosphere using a catalytic exhaust system. Described technical solutions can be used for development of other types of gas turbine compressor packages.

U. K. to resume natural gas imports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-02-17

This paper reports that the U.K. government has opened the way for resuming gas imports into Britain by approving a contract signed by U.K. electric power utility National Power to buy gas from Norway. A new joint marketing venture of BP Exploration, Den norske stats oljeselskap AS (Statoil), and Norsk Hydro AS also will be allowed to import gas for electric power plant fuel once it has a contract. National Power and the BP/Statoil/Norsk Hydro group will use the Frigg pipeline from Norwegian waters into St. Fergus, north of Aberdeen, the only existing link between the British transmission system andmore » foreign supplies of gas. Meantime, progress is under way toward a second pipeline to link the U.K. with foreign natural gas supplies, calling for a pipeline across the English Channel joining the continental European pipeline system to the U.K. network.« less

Prediction of active control of subsonic centrifugal compressor rotating stall

NASA Technical Reports Server (NTRS)

Lawless, Patrick B.; Fleeter, Sanford

1993-01-01

A mathematical model is developed to predict the suppression of rotating stall in a centrifugal compressor with a vaned diffuser. This model is based on the employment of a control vortical waveform generated upstream of the impeller inlet to damp weak potential disturbances that are the early stages of rotating stall. The control system is analyzed by matching the perturbation pressure in the compressor inlet and exit flow fields with a model for the unsteady behavior of the compressor. The model was effective at predicting the stalling behavior of the Purdue Low Speed Centrifugal Compressor for two distinctly different stall patterns. Predictions made for the effect of a controlled inlet vorticity wave on the stability of the compressor show that for minimum control wave magnitudes, on the order of the total inlet disturbance magnitude, significant damping of the instability can be achieved. For control waves of sufficient amplitude, the control phase angle appears to be the most important factor in maintaining a stable condition in the compressor.

Core compressor exit stage study, 2

NASA Technical Reports Server (NTRS)

Behlke, R. F.; Burdsall, E. A.; Canal, E., Jr.; Korn, N. D.

1979-01-01

A total of two three-stage compressors were designed and tested to determine the effects of aspect ratio on compressor performance. The first compressor was designed with an aspect ratio of 0.81; the other, with an aspect ratio of 1.22. Both compressors had a hub-tip ratio of 0.915, representative of the rear stages of a core compressor, and both were designed to achieve a 15.0% surge margin at design pressure ratios of 1.357 and 1.324, respectively, at a mean wheel speed of 167 m/sec. At design speed the 0.81 aspect ratio compressor achieved a pressure ratio of 1.346 at a corrected flow of 4.28 kg/sec and an adiabatic efficiency of 86.1%. The 1.22 aspect ratio design achieved a pressure ratio of 1.314 at 4.35 kg/sec flow and 87.0% adiabatic efficiency. Surge margin to peak efficiency was 24.0% with the lower aspect ratio blading, compared with 12.4% with the higher aspect ratio blading.

Impact of inlet coherent motions on compressor performance

NASA Astrophysics Data System (ADS)

Forlese, Jacopo; Spoleti, Giovanni

2017-08-01

Automotive engine induction systems may be characterized by significant flow angularity and total pressure distortion at the compressor inlet. The impact of the swirl on compressor performance should be quantified to guide the design of the induction systems. In diesel engines, the presence of a valve for flow reduction and control of low pressure EGR recirculation could generate coherent motion and influence the performance of the compressor. Starting from experimental map, the compressor speed-lines have been simulated using a 3D CFD commercial code imposing different concept motion at the inlet. The swirl intensity, the direction and the number of vortices have been imposed in order to taking into account some combinations. Finally, a merit function has been defined to evaluate the performance of the compressor with the defined swirl concepts. The aim of the current work is to obtain an indication on the effect of a swirling motion at the compressor inlet on the engine performance and provide a guideline to the induction system design.

The Supersonic Axial-Flow Compressor

NASA Technical Reports Server (NTRS)

Kantrowitz, Arthur

1950-01-01

An investigation has been made to explore the possibilities of axial-flow compressors operating with supersonic velocities into the blade rows. Preliminary calculations showed that very high pressure ratios across a stage, together with somewhat increased mass flows, were apparently possible with compressors which decelerated air through the speed of sound in their blading. The first phase of the investigation was the development of efficient supersonic diffusers to decelerate air through the speed of sound. The present report is largely a general discussion of some of the essential aerodynamics of single-stage supersonic axial-flow compressors. As an approach to the study of supersonic compressors, three possible velocity diagrams are discussed briefly. Because of the encouraging results of this study, an experimental single-stage supersonic compressor has been constructed and tested in Freon-12. In this compressor, air decelerates through the speed of sound in the rotor blading and enters the stators at subsonic speeds. A pressure ratio of about 1.8 at an efficiency of about 80 percent has been obtained.

Aerodynamic Design of a Four-Stage Low-Speed Axial Compressor for Cantilevered Stator Research

NASA Astrophysics Data System (ADS)

Wallace, James N.

This research is focused on the baseline aerodynamic design of a four-stage low-speed axial compressor with the intent to achieve similarity of cantilevered stator hub leakage flows with those in the rear stages of Siemens large gas turbine compressors. The baseline airfoil design is to act as a comparison for all future research completed in the low speed compressor and, therefore, will not include possible future research topics such as 3-D airfoil geometry or end-wall contouring. Following the design of the airfoils is the aerodynamic design of the facility including the inlet and exhaust. These components were designed to eliminate interactions of the compressor with the facility and to accommodate instrumentation. A baseline set of aerodynamic instrumentation is then suggested to characterize compressor performance. Fully 3-D steady CFD was used extensively during the design of both the facility and the compressor, as well as determining the locations and types of instrumentation.

High Dynamic Range Spectral Imaging Pipeline For Multispectral Filter Array Cameras.

PubMed

Lapray, Pierre-Jean; Thomas, Jean-Baptiste; Gouton, Pierre

2017-06-03

Spectral filter arrays imaging exhibits a strong similarity with color filter arrays. This permits us to embed this technology in practical vision systems with little adaptation of the existing solutions. In this communication, we define an imaging pipeline that permits high dynamic range (HDR)-spectral imaging, which is extended from color filter arrays. We propose an implementation of this pipeline on a prototype sensor and evaluate the quality of our implementation results on real data with objective metrics and visual examples. We demonstrate that we reduce noise, and, in particular we solve the problem of noise generated by the lack of energy balance. Data are provided to the community in an image database for further research.

Employing Machine-Learning Methods to Study Young Stellar Objects

NASA Astrophysics Data System (ADS)

Moore, Nicholas

2018-01-01

Vast amounts of data exist in the astronomical data archives, and yet a large number of sources remain unclassified. We developed a multi-wavelength pipeline to classify infrared sources. The pipeline uses supervised machine learning methods to classify objects into the appropriate categories. The program is fed data that is already classified to train it, and is then applied to unknown catalogues. The primary use for such a pipeline is the rapid classification and cataloging of data that would take a much longer time to classify otherwise. While our primary goal is to study young stellar objects (YSOs), the applications extend beyond the scope of this project. We present preliminary results from our analysis and discuss future applications.

ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF ROTATING STALL PHENOMENA IN TURBINE ENGINE COMPRESSORS.

DTIC Science & Technology

AXIAL FLOW COMPRESSORS, STALLING), TURBOJET ENGINES , AXIAL FLOW COMPRESSOR BLADES , LIFT, HYSTERESIS, TURBULENCE, INLET GUIDE VANES , RINGS, STABILITY, THREE DIMENSIONAL FLOW, VISCOSITY, VORTICES, FLUIDICS.

Development of a test rig for a helium twin-screw compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, B. M.; Hu, Z. J.; Zhang, P.

2014-01-29

A large helium cryogenic system is being developed for use in great science projects, such as the International Thermonuclear Experimental Reactor (ITER), Large Helical Device (LHD), and the Experimental Advanced Superconducting Tokamak (EAST). In this cryogenic system, a twin-screw compressor is a key component. Therefore, it is necessary to obtain the compressor performance. To obtain the performance characteristics, a test rig for the compressor has been built. All the important performance parameters, including adiabatic efficiency, volumetric efficiency, oil injection characteristic, and noise characteristic can be acquired with the rig when sensors are installed in the test system. With the testmore » performance, the helium twin-screw compressor can be evaluated. Using these results, the design of the compressor can be improved.« less

Unsteady Loss in the Stator Due to the Incoming Rotor Wake in a Highly-Loaded Transonic Compressor

NASA Technical Reports Server (NTRS)

Hah, Chunill

2015-01-01

The present paper reports an investigation of unsteady loss generation in the stator due to the incoming rotor wake in an advanced GE transonic compressor design with a high-fidelity numerical method. This advanced compressor with high reaction and high stage loading has been investigated both experimentally and analytically in the past. The measured efficiency in this advanced compressor is significantly lower than the design intention goal. The general understanding is that the current generation of compressor design analysis tools miss some important flow physics in this modern compressor design. To pinpoint the source of the efficiency miss, an advanced test with a detailed flow traverse was performed for the front one and a half stage at the NASA Glenn Research Center.

Refrigeration system having standing wave compressor

DOEpatents

Lucas, Timothy S.

1992-01-01

A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

Compressor discharge bleed air circuit in gas turbine plants and related method

DOEpatents

Anand, Ashok Kumar; Berrahou, Philip Fadhel; Jandrisevits, Michael

2002-01-01

A gas turbine system that includes a compressor, a turbine component and a load, wherein fuel and compressor discharge bleed air are supplied to a combustor and gaseous products of combustion are introduced into the turbine component and subsequently exhausted to atmosphere. A compressor discharge bleed air circuit removes bleed air from the compressor and supplies one portion of the bleed air to the combustor and another portion of the compressor discharge bleed air to an exhaust stack of the turbine component in a single cycle system, or to a heat recovery steam generator in a combined cycle system. In both systems, the bleed air diverted from the combustor may be expanded in an air expander to reduce pressure upstream of the exhaust stack or heat recovery steam generator.

Compressor discharge bleed air circuit in gas turbine plants and related method

DOEpatents

Anand, Ashok Kumar [Niskayuna, NY; Berrahou, Philip Fadhel [Latham, NY; Jandrisevits, Michael [Clifton Park, NY

2003-04-08

A gas turbine system that includes a compressor, a turbine component and a load, wherein fuel and compressor discharge bleed air are supplied to a combustor and gaseous products of combustion are introduced into the turbine component and subsequently exhausted to atmosphere. A compressor discharge bleed air circuit removes bleed air from the compressor and supplies one portion of the bleed air to the combustor and another portion of the compressor discharge bleed air to an exhaust stack of the turbine component in a single cycle system, or to a heat recovery steam generator in a combined cycle system. In both systems, the bleed air diverted from the combustor may be expanded in an air expander to reduce pressure upstream of the exhaust stack or heat recovery steam generator.

Heat shield manifold system for a midframe case of a gas turbine engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayer, Clinton A.; Eng, Jesse; Schopf, Cheryl A.

A heat shield manifold system for an inner casing between a compressor and turbine assembly is disclosed. The heat shield manifold system protects the outer case from high temperature compressor discharge air, thereby enabling the outer case extending between a compressor and a turbine assembly to be formed from less expensive materials than otherwise would be required. In addition, the heat shield manifold system may be configured such that compressor bleed air is passed from the compressor into the heat shield manifold system without passing through a conventional flange to flange joint that is susceptible to leakage.

Experimental on-stream elimination of resonant whirl in a large centrifugal compressor

NASA Technical Reports Server (NTRS)

Bhat, G. I.; Eierman, R. G.

1984-01-01

Resonant whirl condition during operation of a multi-stage centrifugal compressor at higher than anticipated speeds and loads was reported. The condition was diagnosed by a large scale computerized Machinery Condition Monitoring System (MACMOS). This computerized system verified that the predominant subsynchronous whirl frequency locked in on the first resonant frequency of the compressor rotor and did not vary with compressor speed. Compressor stability calculations showed the rotor system had excessive hearing stiffness and inadequate effective damping. An optimum bearing design which was developed to minimize the unbalance response and to maximize the stability threshold is presented.

Thermodynamic properties of UF sub 6 measured with a ballistic piston compressor

NASA Technical Reports Server (NTRS)

Sterritt, D. E.; Lalos, G. T.; Schneider, R. T.

1973-01-01

From experiments performed with a ballistic piston compressor, certain thermodynamic properties of uranium hexafluoride were investigated. Difficulties presented by the nonideal processes encountered in ballistic compressors are discussed and a computer code BCCC (Ballistic Compressor Computer Code) is developed to analyze the experimental data. The BCCC unfolds the thermodynamic properties of uranium hexafluoride from the helium-uranium hexafluoride mixture used as the test gas in the ballistic compressor. The thermodynamic properties deduced include the specific heat at constant volume, the ratio of specific heats for UF6, and the viscous coupling constant of helium-uranium hexafluoride mixtures.

Rotating stall simulation for axial and centrifugal compressors

NASA Astrophysics Data System (ADS)

Halawa, Taher; Gadala, Mohamed S.

2017-05-01

This study presents a numerical simulation of the rotating stall phenomenon in axial and centrifugal compressors with detailed descriptions of stall precursors and its development with time. Results showed that the vaneless region of the centrifugal compressor is the most critical location affected by stall. It was found that the tip leakage flow and the back flow impingement are the main cause of the stall development at the impeller exit area for centrifugal compressors. The results of the axial compressor simulations indicated that the early separated flow combined with the tip leakage flow can block the impeller passages during stall.

Improved heat switch for gas sorption compressor

NASA Technical Reports Server (NTRS)

Chan, C. K.

1985-01-01

Thermal conductivities of the charcoal bed and the copper matrix for the gas adsorption compressor were measured by the concentric-cylinder method. The presence of the copper matrix in the charcoal bed enhanced the bed conductance by at least an order of magnitude. Thermal capacities of the adsorbent cell and the heat leaks to two compressor designs were measured by the transient method. The new gas adsorption compressor had a heat switch that could transfer eight times more heat than the previous one. The cycle time for the new prototype compressor is also improved by a factor of eight to within the minute range.

Advanced two-stage compressor program design of inlet stage

NASA Technical Reports Server (NTRS)

Bryce, C. A.; Paine, C. J.; Mccutcheon, A. R. S.; Tu, R. K.; Perrone, G. L.

1973-01-01

The aerodynamic design of an inlet stage for a two-stage, 10/1 pressure ratio, 2 lb/sec flow rate compressor is discussed. Initially a performance comparison was conducted for an axial, mixed flow and centrifugal second stage. A modified mixed flow configuration with tandem rotors and tandem stators was selected for the inlet stage. The term conical flow compressor was coined to describe a particular type of mixed flow compressor configuration which utilizes axial flow type blading and an increase in radius to increase the work input potential. Design details of the conical flow compressor are described.

Quantitative risk assessment of CO2 transport by pipelines--a review of uncertainties and their impacts.

PubMed

Koornneef, Joris; Spruijt, Mark; Molag, Menso; Ramírez, Andrea; Turkenburg, Wim; Faaij, André

2010-05-15

A systematic assessment, based on an extensive literature review, of the impact of gaps and uncertainties on the results of quantitative risk assessments (QRAs) for CO(2) pipelines is presented. Sources of uncertainties that have been assessed are: failure rates, pipeline pressure, temperature, section length, diameter, orifice size, type and direction of release, meteorological conditions, jet diameter, vapour mass fraction in the release and the dose-effect relationship for CO(2). A sensitivity analysis with these parameters is performed using release, dispersion and impact models. The results show that the knowledge gaps and uncertainties have a large effect on the accuracy of the assessed risks of CO(2) pipelines. In this study it is found that the individual risk contour can vary between 0 and 204 m from the pipeline depending on assumptions made. In existing studies this range is found to be between <1m and 7.2 km. Mitigating the relevant risks is part of current practice, making them controllable. It is concluded that QRA for CO(2) pipelines can be improved by validation of release and dispersion models for high-pressure CO(2) releases, definition and adoption of a universal dose-effect relationship and development of a good practice guide for QRAs for CO(2) pipelines. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Flow Characterization and Dynamic Analysis of a Radial Compressor with Passive Method of Surge Control

NASA Astrophysics Data System (ADS)

Guillou, Erwann

Due to recent emission regulations, the use of turbochargers for force induction of internal combustion engines has increased. Actually, the trend in diesel engines is to downsize the engine by use of turbochargers that operate at higher pressure ratio. Unfortunately, increasing the rotational speed tends to reduce the turbocharger radial compressor range of operation which is limited at low mass flow rate by the occurrence of surge. In order to extent the operability of turbochargers, compressor housings can be equipped with a passive surge control device also known as ported shroud. This specific casing treatment has been demonstrated to enhance surge margin with minor negative impact on the compressor efficiency. However, the actual working mechanisms of the bypass system remain not well understood. In order to optimize the design of the ported shroud, it is then crucial to identify the dynamic flow changes induced by the implementation of the device to control instabilities. Experimental methods were used to assess the development of instabilities from stable, stall and eventually surge regimes of a ported shroud centrifugal compressor. Systematic comparison was conducted with the same compressor design without ported shroud. Hence, the full pressure dynamic survey of both compressors' performance characteristics converged toward two different and probably interrelated driving mechanisms to the development and/or propagation of unsteadiness within each compressor. One related the pressure disturbances at the compressor inlet, and notably the more apparent development of perturbations in the non-ported compressor impeller, whereas the other was attributed to the pressure distortions induced by the presence of the tongue in the asymmetric design of the compressor volute. Specific points of operation were selected to carry out planar flow measurements. At normal working, both standard and stereoscopic particle imaging velocimetry (PIV) measurements were performed to calculate the instantaneous and mean velocity fields at the inlet of the compressor. At incipient and full surge, phase-locked PIV measurements were added. In this work, satisfying characterization of the compressor inlet flow instabilities was obtained at different operational speeds. Combining transient pressure data and PIV measurements, the time evolution of the complex flow patterns occurring at surge was reconstructed and a better insight into the bypass mechanisms was achieved.

Lubrication free centrifugal compressor. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gottschlich, J.M.; Scaringe, R.P.; Gui, F.

1994-04-22

This paper describes an effort to demonstrate the benefits of an innovative, lightweight, lubrication free centrifugal compressor that allows the use of environmentally sale alternate refrigerants with improved system efficiencies over current state-of-the-art technology. This effort couples the recently developed 3-D high efficiency centrifugal compressor and fabrication technologies with magnetic bearing technology and will then prove the performance, life and reliability of the compressor.

Transonic Fan/Compressor Rotor Design Study. Volume 4

DTIC Science & Technology

1982-02-01

amd Identify by block number) Fan Aircraft Engines Compressor Blade Thickness Rotor Camber Distribution Aerodesign Throat Margin Aerodynamics 20...COMPRESSOR ROTOR DESIGN STUDY Volume IV D.E. Parker and M.R. Simonson General Electric Company Aircraft Engine Business Group Advanced Technology...Compressor Research Group Chief, Technology Branch FOR THE COMMANDER H. IVAN BUS Director, Turbine Engine Division If your address has changed, if you

Prediction of wax buildup in 24 inch cold, deep sea oil loading line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asperger, R.G.; Sattler, R.E.; Tolonen, W.J.

1981-10-01

When designing pipelines for cold environments, it is important to know how to predict potential problems due to wax deposition on the pipeline's inner surface. The goal of this work was to determine the rate of wax buildup and the maximum, equlibrium wax thickness for a North Sea field loading line. The experimental techniques and results used to evaluate the waxing potential of the crude oil (B) are described. Also, the theoretic model which was used for predicting the maximum wax deposit thickness in the crude oil (B) loading pipeline at controlled temperatures of 40 F (4.4 C) and 100more » F (38 C), is illustrated. Included is a recommendation of a procedure for using hot oil at the end of a tanker loading period in order to dewax the crude oil (B) line. This technique would give maximum heating of the pipeline and should be followed by shutting the hot oil into the pipeline at the end of the loading cycle which will provide a hot oil soaking to help soften existing wax. 14 references.« less

Peering into the pharmaceutical "pipeline": investigational drugs, clinical trials, and industry priorities.

PubMed

Fisher, Jill A; Cottingham, Marci D; Kalbaugh, Corey A

2015-04-01

In spite of a growing literature on pharmaceuticalization, little is known about the pharmaceutical industry's investments in research and development (R&D). Information about the drugs being developed can provide important context for existing case studies detailing the expanding--and often problematic--role of pharmaceuticals in society. To access the pharmaceutical industry's pipeline, we constructed a database of drugs for which pharmaceutical companies reported initiating clinical trials over a five-year period (July 2006-June 2011), capturing 2477 different drugs in 4182 clinical trials. Comparing drugs in the pipeline that target diseases in high-income and low-income countries, we found that the number of drugs for diseases prevalent in high-income countries was 3.46 times higher than drugs for diseases prevalent in low-income countries. We also found that the plurality of drugs in the pipeline was being developed to treat cancers (26.2%). Interpreting our findings through the lens of pharmaceuticalization, we illustrate how investigating the entire drug development pipeline provides important information about patterns of pharmaceuticalization that are invisible when only marketed drugs are considered. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reliability evaluation of oil pipelines operating in aggressive environment

NASA Astrophysics Data System (ADS)

Magomedov, R. M.; Paizulaev, M. M.; Gebel, E. S.

2017-08-01

In connection with modern increased requirements for ecology and safety, the development of diagnostic services complex is obligatory and necessary enabling to ensure the reliable operation of the gas transportation infrastructure. Estimation of oil pipelines technical condition should be carried out not only to establish the current values of the equipment technological parameters in operation, but also to predict the dynamics of changes in the physical and mechanical characteristics of the material, the appearance of defects, etc. to ensure reliable and safe operation. In the paper, existing Russian and foreign methods for evaluation of the oil pipelines reliability are considered, taking into account one of the main factors leading to the appearance of crevice in the pipeline material, i.e. change the shape of its cross-section, - corrosion. Without compromising the generality of the reasoning, the assumption of uniform corrosion wear for the initial rectangular cross section has been made. As a result a formula for calculation the probability of failure-free operation was formulated. The proposed mathematical model makes it possible to predict emergency situations, as well as to determine optimal operating conditions for oil pipelines.

Applying Diversity Management Concepts to Improve the Minority Educational Pipeline

ERIC Educational Resources Information Center

Oguntebi, Joy; Shcherbakova, Maria; Wooten, Lynn P.

2012-01-01

The objective of this conceptual article is to investigate existing diversity management paradigms and extend their implications toward the goal of increasing minority representation in management education. We suggest that the existing learning-and-effectiveness diversity management paradigm (Thomas & Ely, 1996, "Harvard Business…