Sample records for ep866sh steel compressor

  1. Research on Fatigue Damage of Compressor Blade Steel KMN-I Using Nonlinear Ultrasonic Testing

    Directory of Open Access Journals (Sweden)

    Pengfei Wang


    Full Text Available The fatigue damage of compressor blade steel KMN-I was investigated using nonlinear ultrasonic testing and the relation curve between the material nonlinearity parameter β and the fatigue life was obtained. The results showed that the nonlinearity parameter increased first and then decreased with the increase of the fatigue cycles. The microstructures were observed by scanning electron microscopy (SEM. It was found that some small defects like holes and pits appeared in the material matrix with the increase of the fatigue cycles, and the nonlinearity parameter increased correspondingly. The nonlinearity parameter reached the peak value when the microcracks initiated, and the nonlinearity parameter began to decrease when the microcracks further propagated to macrocracks. Therefore, it is proved that the nonlinearity parameter can be used to characterize the initiation of microcracks at the early stage of fatigue, and a method of evaluating the fatigue life of materials by nonlinear ultrasonic testing is proposed.

  2. Corrosion-resistant coating for GTE compressor parts made of steels with low tempering temperatures (United States)

    Muboyadzhyan, S. A.; Egorova, L. P.; Gorlov, D. S.; Bulavintseva, E. E.


    The corrosion resistance of an Ni-Co-Cr-Al-Si-Y + SPh (SPh is silicophosphate impregnation) alloy coating on 30Kh13, 38Kh2MYuA, VKS5, and VKS7 structural steels with low tempering temperatures has been studied. The steel-coating compositions have been tested to determine the accelerated cyclic corrosion resistance, the corrosion resistance under tropic climate chamber conditions and in salt fog, the stress corrosion resistance, and the corrosion resistance in an industrial atmosphere. The heat stability of coated samples is studied, metallographic studies of the samples before and after the tests are performed, and the influence of the coating on the strength characteristics of the structural steels is studied.

  3. Mitigation of FOD and Corrosion Fatigue Damage in 17-4 PH Stainless Steel Compressor Blades With Surface Treatment

    National Research Council Canada - National Science Library

    Prevey, Paul S; Jayaraman, N; Ravindranath, Ravi


    ... the geometrical conditions of thick section and blade leading edges of compressor blades. The FOD tolerance and corrosion fatigue performance of 17-4PH prepared by low plasticity burnishing (LPB), shot peening (SP...

  4. High Speed Compressor Study (United States)


    Davey G. The Design and Testing of a Stirling Cycle Domestic Freezer. Proc. of Conference on Applications for Natural Refrigerants , held in Aarhus...carried out on a relatively old design of compressor, initially developed for use with a Stirling cycle domestic freezer12, and subsequently used in a...limit’, and is suitable for high cycle fatigue. Beryllium copper has been largely superseded by stainless steel, which is more readily available

  5. On Refrigerant Compressors


    McGovern, Jim


    The purpose of the work was to critically re-examine and investigate the evaluation of refrigerant compressors and to determine and discriminate between the factors which influence their characteristics. The objectives also included the investigation of techniques by which the characteristics can be established and the suggestion of ways in which compressor performance can be described and quantified. The particular compressor which was tested was of the reciprocating open type. Existing theo...

  6. Compressors selection and sizing

    CERN Document Server

    Brown, Royce N


    This practical reference provides in-depth information required to understand and properly estimate compressor capabilities and to select the proper designs. Engineers and students will gain a thorough understanding of compression principles, equipment, applications, selection, sizing, installation, and maintenance. The many examples clearly illustrate key aspects to help readers understand the ""real world"" of compressor technology.Compressors: Selection and Sizing, third edition is completely updated with new API standards. Additions requested by readers include a new section on di

  7. Gravity Independent Compressor Project (United States)

    National Aeronautics and Space Administration — We propose to develop and demonstrate a small, gravity independent, vapor compression refrigeration system using a linear motor compressor which effectively...

  8. Displacement compressors - acceptance tests

    CERN Document Server

    International Organization for Standardization. Geneva


    ISO 1217:2009 specifies methods for acceptance tests regarding volume rate of flow and power requirements of displacement compressors. It also specifies methods for testing liquid-ring type compressors and the operating and testing conditions which apply when a full performance test is specified.

  9. Electrochemical Hydrogen Compressor

    Energy Technology Data Exchange (ETDEWEB)

    David P. Bloomfield; Brian S. MacKenzie


    The Electrochemical Hydrogen Compressor EHC was evaluated against DOE applications for compressing hydrogen at automobile filling stations, in future hydrogen pipelines and as a commercial replacement for conventional diaphragm hydrogen compressors. It was also evaluated as a modular replacement for the compressors used in petrochemical refineries. If the EHC can be made inexpensive, reliable and long lived then it can satisfy all these applications save pipelines where the requirements for platinum catalyst exceeds the annual world production. The research performed did not completely investigate Molybdenum as a hydrogen anode or cathode, it did show that photoetched 316 stainless steel is inadequate for an EHC. It also showed that: molybdenum bipolar plates, photochemical etching processes, and Gortex Teflon seals are too costly for a commercial EHC. The use of carbon paper in combination with a perforated thin metal electrode demonstrated adequate anode support strength, but is suspect in promoting galvanic corrosion. The nature of the corrosion mechanisms are not well understood, but locally high potentials within the unit cell package are probably involved. The program produced a design with an extraordinary high cell pitch, and a very low part count. This is one of the promising aspects of the redesigned EHC. The development and successful demonstration of the hydraulic cathode is also important. The problem of corrosion resistant metal bipolar plates is vital to the development of an inexpensive, commercial PEM fuel cell. Our research suggests that there is more to the corrosion process in fuel cells and electrochemical compressors than simple, steady state, galvanic stability. It is an important area for scientific investigation. The experiments and analysis conducted lead to several recommended future research directions. First, we need a better understanding of the corrosion mechanisms involved. The diagnosis of experimental cells with titration to

  10. Electrochemical Hydrogen Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Lipp, Ludwig [FuelCell Energy, Inc., Torrington, CT (United States)


    Conventional compressors have not been able to meet DOE targets for hydrogen refueling stations. They suffer from high capital cost, poor reliability and pose a risk of fuel contamination from lubricant oils. This project has significantly advanced the development of solid state hydrogen compressor technology for multiple applications. The project has achieved all of its major objectives. It has demonstrated capability of Electrochemical Hydrogen Compression (EHC) technology to potentially meet the DOE targets for small compressors for refueling sites. It has quantified EHC cell performance and durability, including single stage hydrogen compression from near-atmospheric pressure to 12,800 psi and operation of EHC for more than 22,000 hours. Capital cost of EHC was reduced by 60%, enabling a path to meeting the DOE cost targets for hydrogen compression, storage and delivery ($2.00-2.15/gge by 2020).

  11. Transonic compressor technology advancements (United States)

    Benser, W. A.


    The highlights of the NASA program on transonic compressors are presented. Effects of blade shape and throat area on losses and flow range are discussed. Some effects of casing treatment on stall margin are presented. Results of tests with varying solidity are also presented. High Mach number, highly loaded stators are discussed and some results of stator hub slit suction are presented.

  12. Compressor reliability survey

    NARCIS (Netherlands)

    Eijk, A.; Lier, L.J. van


    The increasing demand for economic plant operation has led to a critical discussion of the equipment as to selection, design, maintenance and automation. The well-known advantages of the reciprocating compressor such as high efficiency under many different operating conditions, comparatively easy

  13. Centrifugal Compressor Aeroelastic Analysis Code (United States)

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


    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.

  14. Compressor performance aerodynamics for the user

    CERN Document Server

    Gresh, Theodore


    Compressor Performance is a reference book and CD-ROM for compressor design engineers and compressor maintenance engineers, as well as engineering students. The book covers the full spectrum of information needed for an individual to select, operate, test and maintain axial or centrifugal compressors. It includes basic aerodynamic theory to provide the user with the ""how's"" and ""why's"" of compressor design. Maintenance engineers will especially appreciate the troubleshooting guidelines offered. Includes many example problems and reference data such as gas propert

  15. Suction muffler for refrigeration compressor (United States)

    Nelson, Richard T.; Middleton, Marc G.


    A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell.

  16. Positive Displacement Compressor Technology for Refrigeration (United States)

    Nagatomo, Shigemi

    Trends of compressor technologies for refrigerators, freezers and condensing units are presented in this paper. HFC refrigerants such as R134a and R404C are promising candidates as an altemative for R12. Performance of reciprocating and rotary compressors in the operation with R134A is described. In addition, compressor technologies such as efficiency improvement are described in the cases of reciprocating, rotary and scroll compressors.

  17. Water injected fuel cell system compressor (United States)

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


    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.

  18. Comprehensive model of a hermetic reciprocating compressor (United States)

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


    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.

  19. Meridional Considerations of the Centrifugal Compressor Development

    Directory of Open Access Journals (Sweden)

    C. Xu


    Full Text Available Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some recent studies of meridional impacts of the compressor. Studies indicated that the meridional profiles of the impeller impact the overall compressor efficiency and pressure ratio at the same rotational speed. Proper meridional profiles can improve the compressor efficiency and increase the overall pressure ratio at the same blade back curvature.

  20. Pulse compressor with aberration correction

    Energy Technology Data Exchange (ETDEWEB)

    Mankos, Marian [Electron Optica, Inc., Palo Alto, CA (United States)


    In this SBIR project, Electron Optica, Inc. (EOI) is developing an electron mirror-based pulse compressor attachment to new and retrofitted dynamic transmission electron microscopes (DTEMs) and ultrafast electron diffraction (UED) cameras for improving the temporal resolution of these instruments from the characteristic range of a few picoseconds to a few nanoseconds and beyond, into the sub-100 femtosecond range. The improvement will enable electron microscopes and diffraction cameras to better resolve the dynamics of reactions in the areas of solid state physics, chemistry, and biology. EOI’s pulse compressor technology utilizes the combination of electron mirror optics and a magnetic beam separator to compress the electron pulse. The design exploits the symmetry inherent in reversing the electron trajectory in the mirror in order to compress the temporally broadened beam. This system also simultaneously corrects the chromatic and spherical aberration of the objective lens for improved spatial resolution. This correction will be found valuable as the source size is reduced with laser-triggered point source emitters. With such emitters, it might be possible to significantly reduce the illuminated area and carry out ultrafast diffraction experiments from small regions of the sample, e.g. from individual grains or nanoparticles. During phase I, EOI drafted a set of candidate pulse compressor architectures and evaluated the trade-offs between temporal resolution and electron bunch size to achieve the optimum design for two particular applications with market potential: increasing the temporal and spatial resolution of UEDs, and increasing the temporal and spatial resolution of DTEMs. Specialized software packages that have been developed by MEBS, Ltd. were used to calculate the electron optical properties of the key pulse compressor components: namely, the magnetic prism, the electron mirror, and the electron lenses. In the final step, these results were folded

  1. Corrosion behavior of construction materials for ionic liquid hydrogen compressor

    DEFF Research Database (Denmark)

    Arjomand Kermani, Nasrin; Petrushina, Irina; Nikiforov, Aleksey Valerievich


    The corrosion behavior of various commercially available stainless steels and nickel-based alloys as possible construction materials for components which are in direct contact with one of five different ionic liquids was evaluated. The ionic liquids, namely: 1-ethyl-3-methylimidazolium triflate, 1...... liquid hydrogen compressor. An electrochemical cell was specially designed, and steady-state cyclic voltammetry was used to measure the corrosion resistance of the alloys in the ionic liquids at 23 °C, under atmospheric pressure. The results showed a very high corrosion resistance and high stability...... for all the alloys tested. The two stainless steels, AISI 316L and AISI 347 showed higher corrosion resistance compared to AISI 321 in all the ionic liquids tested. It was observed that small addition of molybdenum, tantalum, and niobium to the alloys increased the corrosion stability in the ionic liquids...

  2. Centrifugal and axial compressor control

    CERN Document Server

    McMillan, Gregory K


    Control engineers, mechanical engineers and mechanical technicians will learn how to select the proper control systems for axial and centrifugal compressors for proper throughput and surge control, with a particular emphasis on surge control. Readers will learn to understand the importance of transmitter speed, digital controller sample time, and control valve stroking time in helping to prevent surge. Engineers and technicians will find this book to be a highly valuable guide on compressor control schemes and the importance of mitigating costly and sometimes catastrophic surge problems. It can be used as a self-tutorial guide or in the classroom with the book's helpful end-of-chapter questions and exercises and sections for keeping notes.

  3. Screw Compressor Characteristics for Helium Refrigeration Systems (United States)

    Ganni, V.; Knudsen, P.; Creel, J.; Arenius, D.; Casagrande, F.; Howell, M.


    The oil injected screw compressors have practically replaced all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, minimal vibration, reliability and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium systems, typically two-thirds of the lost input power is due to the compression system. Therefore it is important to understand the isothermal and volumetric efficiencies of these machines to help properly design these compression systems to match the refrigeration process. This presentation summarizes separate tests that have been conducted on Sullair compressors at the Superconducting Super-Collider Laboratory (SSCL) in 1993, Howden compressors at Jefferson Lab (JLab) in 2006 and Howden compressors at the Spallation Neutron Source (SNS) in 2006. This work is part of an ongoing study at JLab to understand the theoretical basis for these efficiencies and their loss mechanisms, as well as to implement practical solutions.

  4. Modelling fluid flow in a reciprocating compressor

    Directory of Open Access Journals (Sweden)

    Tuhovcak Jan


    Full Text Available Efficiency of reciprocating compressor is strongly dependent on the valves characteristics, which affects the flow through the suction and discharge line. Understanding the phenomenon inside the compressor is necessary step in development process. Commercial CFD tools offer wide capabilities to simulate the flow inside the reciprocating compressor, however they are too complicated in terms of computational time and mesh creation. Several parameters describing compressor could be therefore examined without the CFD analysis, such is valve characteristic, flow through the cycle and heat transfer. The aim of this paper is to show a numerical tool for reciprocating compressor based on the energy balance through the cycle, which provides valve characteristics, flow through the cycle and heat losses from the cylinder. Spring-damping-mass model was used for the valve description. Boundary conditions were extracted from the performance test of 4-cylinder semihermetic compressor and numerical tool validation was performed with indicated p-V diagram comparison.

  5. Oil cooled, hermetic refrigerant compressor (United States)

    English, W.A.; Young, R.R.


    A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler and is then delivered through the shell to the top of the motor rotor where most of it is flung radially outwardly within the confined space provided by the cap which channels the flow of most of the oil around the top of the stator and then out to a multiplicity of holes to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator from which the suction gas passes by a confined path in pipe to the suction plenum and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum. 3 figs.

  6. Consider multishaft compressors for hazardous applications

    Energy Technology Data Exchange (ETDEWEB)

    Roy, G.K. [Pt. Indo-Rama Synthetics, West Java (Indonesia)


    API specifies two types of centrifugal compressors: single-shaft (inline) and integrally geared. The latter are mainly air compressors, and API 672, which specifies the design, manufacturing and testing of these compressors, recommends that they may be used for gas services other than air that are nonhazardous and non-toxic. These compressors offer high efficiency, high control range, lower mechanical losses, lower investment and extremely compact design. Advances in gear making technology and design make API 672 compressors highly competitive in certain applications. The single-shaft compressor is used for general refinery services, is governed by API 617, and applicable for air or gas. There is no restriction on the type of gas. Therefore, this compressor is universally applicable for any gas--hazardous or nonhazardous. A large variety of integrally-geared multishaft compressors are available with respect to the number of stages, type of gas, type of drive and pressure range. These compressors have enormous range in terms of volumetric flows, pressure ratios, allowable inlet and discharge pressures, and attainable drive speeds. API 672 compressors find large applications in process, plant and instrument air service, air separation plants, etc. Apart from air, the gases handled by API 672 compressors had been for other nonhazardous applications such as nitrogen, steam, etc. Contrary to API 672 stipulations, multishaft compressors have been used for along time in hazardous applications like refinery offgas, CH{sub 4}, oxygen, or mixtures of NH{sub 3} and CO{sub 2}, CO, HCN, etc., or even dry chlorine.

  7. Aspirated Compressors for High Altitude Engines Project (United States)

    National Aeronautics and Space Administration — Aurora Flight Sciences proposes to incorporate aspirated compressor technology into a high altitude, long endurance (HALE) concept engine. Aspiration has been proven...

  8. Regenerative sorption compressors for cryogenic refrigeration (United States)

    Bard, Steven; Jones, Jack A.

    Dramatic efficiency improvements for sorption coolers appear possible with use of compressor heat regeneration techniques. The general theory of sorption compressor heat regeneration is discussed in this paper, and several design concepts are presented. These designs result in long-life, low-vibration cryocoolers that potentially have efficiencies comparable to Stirling refrigerators for 65 to 90 K spacecraft instrument cooling applications.


    Directory of Open Access Journals (Sweden)

    M. V. Tsabenko


    Full Text Available The article investigates the anti-surge protection systems and mathematical modeling of systems of gas compressor units on the basis of centrifugal compressors with anti-surge valve or baypass, and a mixed protection system. The review of existing systems, surge protection of gas compressor units, which revealed a number of shortcomings when using antisurge valve or baypass system. The proposed mixed system of surge protection with simultaneous use of surge valve and baypass system. The proposed sequence of the mixed system of surge protection. The above block diagram of an electromechanical system centrifugal compressor – anti-surge valve - direct current motor with an automatic control system. Obtained by use of transient surge valve baypass and mixed anti-surge system. These conclusions underline the relevance of the research and energy efficiency centrifugal compressor anti-surge protection system.

  10. Centrifugal compressor design for electrically assisted boost (United States)

    Y Yang, M.; Martinez-Botas, R. F.; Zhuge, W. L.; Qureshi, U.; Richards, B.


    Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically.

  11. NG compressors play role in success story

    Energy Technology Data Exchange (ETDEWEB)



    In early 1993, Con Edison and Brooklyn Union Gas began offering rebates to manufacturers that replaced electric motor-driven air compressors with natural gas engine-driven air compressors. These rebates covered significant portions of the costs of installation. After carefully considering all options, Ultra Creative decided to order two Quincy QSS-750-NG, 220-HP units from scales Air Compressor Crop. Scales is a full-service air compressor distribution which offers complete turnkey installation service on all types of stationary air compressors, plus maintenance and repairs. The complete Quincy QSS Series of natural gas engine-driven air compressors is available in sizes from 370 to 1500 cfm. An optical heat recovery system can boost energy efficiencies over 80%. For example, heat recovered from the engine cooling water and exhaust, combined with the heat recovered from the air compressor oil cooler and aftercooler, can be used for heating boiler and laundry process water, plastics thermoforming, unit heaters for space heating, plating tanks, and a variety of other applications to displace conventional fuels.

  12. Compressor Properties in Sucking Two Phase Refrigerant (United States)

    Inoue, Seiji; Nakayama, Masahiro; Matsuoka, Fumio

    A simulation model is proposed to analyze refrigerant properties in suction,compression and discharge process in rotary compressors,and compressor performance is analyzed by the calculations and the experiments in this paper. Heat transfer coefficients between the cylinder and refrigerant both in sucking two phase and superheated gas refrigerant have been evaluated by the calculations performed under the condition of the experiments since the validity of the simulation model has been proved by the agreement of the calculation results with the experimental ones. Linear relationship of discharge and cylinder temperature to compressor frequency and suction quality has been clarified by the experimental results. Mechanisms of the compressor performance have also analyzed by the refrigerant properties in the compression mechanism calculated every angle of the rolling piston in detail.

  13. High Speed Compressor for Subcooling Propellants Project (United States)

    National Aeronautics and Space Administration — Propellant densification systems for LH2 require compression systems that develop significant head. In the past this has required multiple stages of compressors...

  14. Virtual Training of Compressor Control Room Project (United States)

    National Aeronautics and Space Administration — MYMIC will analyze, design, develop and evaluate the Virtual Control Room – Compressor Station (VCoR-CS) training system. VCoR-CS will provide procedural...

  15. Refrigeration system having dual suction port compressor (United States)

    Wu, Guolian


    A cooling system for appliances, air conditioners, and other spaces includes a compressor, and a condenser that receives refrigerant from the compressor. The system also includes an evaporator that receives refrigerant from the condenser. Refrigerant received from the condenser flows through an upstream portion of the evaporator. A first portion of the refrigerant flows to the compressor without passing through a downstream portion of the evaporator, and a second portion of the refrigerant from the upstream portion of the condenser flows through the downstream portion of the evaporator after passing through the upstream portion of the evaporator. The second portion of the refrigerant flows to the compressor after passing through the downstream portion of the evaporator. The refrigeration system may be configured to cool an appliance such as a refrigerator and/or freezer, or it may be utilized in air conditioners for buildings, motor vehicles, or other such spaces.

  16. Cooling system having dual suction port compressor (United States)

    Wu, Guolian


    A cooling system for appliances, air conditioners, and other spaces includes a compressor, and a condenser that receives refrigerant from the compressor. The system also includes an evaporator that receives refrigerant from the condenser. Refrigerant received from the condenser flows through an upstream portion of the evaporator. A first portion of the refrigerant flows to the compressor without passing through a downstream portion of the evaporator, and a second portion of the refrigerant from the upstream portion of the condenser flows through the downstream portion of the evaporator after passing through the upstream portion of the evaporator. The second portion of the refrigerant flows to the compressor after passing through the downstream portion of the evaporator. The refrigeration system may be configured to cool an appliance such as a refrigerator and/or freezer, or it may be utilized in air conditioners for buildings, motor vehicles, or other such spaces.

  17. Alternatives to compressor cooling in California climates

    Energy Technology Data Exchange (ETDEWEB)

    Feustel, H. (Lawrence Berkeley Lab., CA (United States)); de Almeida, A. (Coimbra Univ. (Portugal). Dept. of Electrical Engineering); Blumstein, C. (California Univ., Berkeley, CA (United States). Universitywide Energy Research Group)


    This review and discussion has been prepared for the California Institute for Energy Efficiency (CIEE) to examine research on alternatives to compressor cooling. The report focuses on strategies for eliminating compressors in California's transition climates -- moderately warm areas located between the cool coastal regions and the hot central regions. Many of these strategies could also help reduce compressor use in hotter climates. Compressor-driven cooling of residences in California's transition climate regions is an undesirable load for California's electric utilities because load factor is poor and usage is typically high during periods of system peak demand. We review a number of alternatives to compressors, including low-energy strategies: evaporative cooling, natural and induced ventilation, reflective coatings, shading with vegetation and improved glazing, thermal storage, and radiative cooling. Also included are two energy-intensive strategies: absorption cooling and desiccant cooling. Our literature survey leads us to conclude that many of these strategies, used either singly or in combination, are technically and economically feasible alternatives to compressor-driven cooling. 78 refs., 8 figs.

  18. Performance of Screw Compressor for Small-Capacity Helium Refrigerators (United States)

    Urashin, Masayuki; Matsubara, Katsumi; Izunaga, Yasushi

    A helium compressor is one of the important components comprising a cryogenic refrigerator. The purpous of this investigation is to develop a new small-capacity helium screw compressor. The performance of a single-stage compressor at high compression ratio and the cooling performance of the compressor are investigated. A semi-hermetic screw compressor with new profile screw rotors, with which high performance can be obtained, is utilized in this investigation. Lubricating oil is applied to cool the compressor motor and the compressed gas. As a result, an overall isentropic efficiency of 80% is obtained when helium is compressed to a compression ratio of 19.8 with a single-stage screw compressor. At the same time, the temperature of a compressor motor and discharge gas can be maintained at low levels. Therefore, it is found that a single-stage screw compressor can compress helium to high compression ratio.

  19. Laser cleaning of sulfide scale on compressor impeller blade

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Q.H., E-mail: [School of Mechanical and Automotive Engineering, Hefei University of Technology, Heifei 230009 (China); Institute of Green Design and Manufacturing Engineering, Hefei University of Technology, Heifei 230009 (China); Zhou, D. [School of Mechanical and Automotive Engineering, Hefei University of Technology, Heifei 230009 (China); Institute of Green Design and Manufacturing Engineering, Hefei University of Technology, Heifei 230009 (China); Wang, Y.L.; Liu, G.F. [Institute of Green Design and Manufacturing Engineering, Hefei University of Technology, Heifei 230009 (China)


    Highlights: • The effects of sulfide layers and fluence values on the mechanism of laser cleaning were experimentally established. • The specimen surface with sulfide scale becomes slightly smoother than that before laser cleaning. • The mechanism of laser cleaning the sulfide scale of stainless steel is spallation without oxidization. • It would avoid chemical waste and dust pollution using a fiber laser instead of using nitric acids or sandblasting. - Abstract: Sulfide scale on the surface of a compressor impeller blade can considerably reduce the impeller performance and its service life. To prepare for subsequent remanufacturing, such as plasma spraying, it needs to be removed completely. In the corrosion process on an FV(520)B stainless steel, sulfide scale is divided into two layers because of different outward diffusion rates of Cr, Ni and Fe. In this paper, the cleaning threshold values of the upper and inner layers and the damage threshold value of the substrate were investigated using a pulsed fiber laser. To obtain experimental evidence, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and 3D surface profilometry were employed to investigate the two kinds of sulfide layers on specimens before, during, and after laser cleaning.

  20. A guide to turbocharger compressor characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Casey, M.V. [Inst. fuer Thermische Stroemungsmaschinen, Univ. Stuttgart (Germany); Robinson, C.J. [PCA Engineers Ltd., Lincoln (United Kingdom)


    The key features of the global performance characteristics of radial compressor stages in turbochargers are reviewed on the basis of elementary 1D compressible flow equations and appropriate non-dimensional flow parameters. The background to the relevant equations is provided and these are then used to explain some features of the shape and form of radial compressor performance characteristics. The discussion explains the different forms of non-dimensional compressor characteristics, the change in performance with rotational speed, the matching between impeller and diffuser at different speeds and the effect of elementary design changes on the performance of a typical stage. Examples are provided using a simple mean-line prediction tool, Vista-CC. Some insight is also given on special issues such as variable geometry, two-stage compression, installation effects and off-design excursions due to the operation of the compressor in the unsteady flow from a engine. The paper is intended as a detailed introduction to turbocharger compressor characteristics for automotive engineers who may not be particularly familiar with turbomachinery technology. (orig.)

  1. Identifying lubricant options for compressor bearing designs (United States)

    Karnaz, J.; Seeton, C.; Dixon, L.


    Today’s refrigeration and air conditioning market is not only driven by the environmental aspects of the refrigerants, but also by the energy efficiency and reliability of system operation. Numerous types of compressor designs are used in refrigeration and air conditioning applications which means that different bearings are used; and in some cases, multiple bearing types within a single compressor. Since only one lubricant is used, it is important to try to optimize the lubricant to meet the various demands and requirements for operation. This optimization entails investigating different types of lubricant chemistries, viscosities, and various formulation options. What makes evaluating these options more challenging is the refrigerant which changes the properties of the lubricant delivered to the bearing. Once the lubricant and refrigerant interaction are understood, through various test methods, then work can start on collaborating with compressor engineers on identifying the lubricant chemistry and formulation options. These interaction properties are important to the design engineer to make decisions on the adequacy of the lubricant before compressor tests are started. This paper will discuss the process to evaluate lubricants for various types of compressors and bearing design with focus on what’s needed for current refrigerant trends. In addition, the paper will show how the lubricant chemistry choice can be manipulated through understanding of the bearing design and knowledge of interaction with the refrigerant to maximize performance. Emphasis will be placed on evaluation of synthetic lubricants for both natural and synthetic low GWP refrigerants.

  2. Novel Compressor Blade Design Study (United States)

    Srinivas, Abhay

    Jet engine efficiency goals are driving compressors to higher pressure ratios and engines to higher bypass ratios, each one driving to smaller cores. This is leading to larger tip gaps relative to the blade height. These larger relative tip clearances would negate some of the cycle improvements, and ways to mitigate this effect must be found. A novel split tip blade geometry has been created which helps improve the efficiency at large clearances while also improving operating range. Two identical blades are leaned in opposite directions starting at 85% span. They are cut at mid chord and the 2 halves then merged together so a split tip is created. The result is similar to the alula feathers on a soaring bird. The concept is that the split tip will energize the tip flow and increase range. For higher relative tip clearance, this will also improve efficiency. The 6th rotor of a highly loaded 10 stage machine was chosen as the baseline for this study. Three dimensional CFD simulations were performed using CD Adapco's Star-CCM+ at 5 clearances for the baseline and split tip geometry. The choking flow and stall margin of the split tip blade was higher than that of the baseline blade for all tip clearances. The pressure ratio of the novel blade was higher than that of the baseline blade near choke, but closer to stall it decreased. The sensitivity of peak efficiency to clearance was improved. At tight clearances of 0.62% of blade height, the maximum efficiency of the new design was less than the baseline blade, but as the tip clearance was increased above 2.5%, the maximum efficiency increased. Structural analysis was also performed to ascertain the feasibility of the design.

  3. Axial Compressor Stall and Surge Prediction by Measurements

    Directory of Open Access Journals (Sweden)

    H. Hönen


    Full Text Available The paper deals with experimental investigations and analyses of unsteady pressure distributions in different axial compressors. Based on measurements in a single stage research compressor the influence of increasing aerodynamic load onto the pressure and velocity fluctuations is demonstrated. Detailed measurements in a 14-stage and a 17-stage gas turbine compressor are reported. For both compressors parameters could be found which are clearly influenced by the aerodynamic load.

  4. Compressor airfoil tip clearance optimization system (United States)

    Little, David A.; Pu, Zhengxiang


    A compressor airfoil tip clearance optimization system for reducing a gap between a tip of a compressor airfoil and a radially adjacent component of a turbine engine is disclosed. The turbine engine may include ID and OD flowpath boundaries configured to minimize compressor airfoil tip clearances during turbine engine operation in cooperation with one or more clearance reduction systems that are configured to move the rotor assembly axially to reduce tip clearance. The configurations of the ID and OD flowpath boundaries enhance the effectiveness of the axial movement of the rotor assembly, which includes movement of the ID flowpath boundary. During operation of the turbine engine, the rotor assembly may be moved axially to increase the efficiency of the turbine engine.

  5. Cost-effective and detailed modelling of compressor manifold vibrations

    NARCIS (Netherlands)

    Eijk, A.; Egas, G.; Smeulers, J.P.M.


    In systems with large reciprocating compressors, so-called compressor manifold vibrations can contribute to fatigue failure of the pipe system. These vibrations are excited by pulsation-induced forces and by forces generated by the compressor. This paper describes an advanced and accurate method for

  6. Cold Climate Heat Pumps Using Tandem Compressors

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Abdelaziz, Omar [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL


    In cold climate zones, e.g. ASHRAE climate regions IV and V, conventional electric air-source heat pumps (ASHP) do not work well, due to high compressor discharge temperatures, large pressure ratios and inadequate heating capacities at low ambient temperatures. Consequently, significant use of auxiliary strip heating is required to meet the building heating load. We introduce innovative ASHP technologies as part of continuing efforts to eliminate auxiliary strip heat use and maximize heating COP with acceptable cost-effectiveness and reliability. These innovative ASHP were developed using tandem compressors, which are capable of augmenting heating capacity at low temperatures and maintain superior part-load operation efficiency at moderate temperatures. Two options of tandem compressors were studied; the first employs two identical, single-speed compressors, and the second employs two identical, vapor-injection compressors. The investigations were based on system modeling and laboratory evaluation. Both designs have successfully met the performance criteria. Laboratory evaluation showed that the tandem, single-speed compressor ASHP system is able to achieve heating COP = 4.2 at 47 F (8.3 C), COP = 2.9 at 17 F (-8.3 C), and 76% rated capacity and COP = 1.9 at -13 F (-25 C). This yields a HSPF = 11.0 (per AHRI 210/240). The tandem, vapor-injection ASHP is able to reach heating COP = 4.4 at 47 F, COP = 3.1 at 17 F, and 88% rated capacity and COP = 2.0 at -13 F. This yields a HSPF = 12.0. The system modeling and further laboratory evaluation are presented in the paper.

  7. Compressor Lattice Design for SPL Beam

    CERN Document Server

    Aiba, M


    A compressor ring providing very short proton bunches of a few ns has been designed as a component of a proton driver in the neutrino factory. Proton beams accelerated with the SPL (Superconducting Proton Linac) are stored in an accumulator ring before being transported to a compressor ring. The bunch compression is then performed with longitudinal phase rotation. For the neutrino factory, a special pulse structure of the primary proton beam is required. In the SPL based proton driver, the specification imposes that six (or five) bunches of a few ns length and about 12μs bunch spacing are formed in one cycle.

  8. Design and prototyping of micro centrifugal compressor (United States)

    Mizuki, Shimpei; Minorikawa, Gaku; Hirano, Toshiyuki; Asaga, Yuichiro; Yamaguchi, Naoki; Ohta, Yutaka; Outa, Eisuke


    In order to establish the design methodology of ultra micro centrifugal compressor, which is the most important component of ultra micro gas turbine unit, a 10 times of the final target size model was designed, prototyped and tested. The problems to be solved for downsizing were examined and 2-dimensional impeller was chosen as the first model due to its productivity. The conventional 1D prediction method, CFD and the inverse design were attempted. The prototyped compressor was driven by using a turbocharger and the performance characteristics were measured.

  9. Development of a J-T Micro Compressor (United States)

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


    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.

  10. Cathode discontinuity in a magnetoplasma compressor (MPC)

    Energy Technology Data Exchange (ETDEWEB)

    Brushlinskii, K.V.; Vinogradova, A.K.; Morozov, A.I.; Savel' ev, V.V.


    A theoretical analysis predicts the possibility of obtaining, with the aid of stationary plasma accelerators and magnetoplasma compressors (MPC), plasma streams having very high parameters at relatively modest energy levels. However, the realization of this possibility encounters many complicated problems connected with the electromagnetic sheaths at the electrodes.

  11. Operating modes of magnetoplasma compressor. II

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradova, A.K.; Morozov, A.I.


    A ''pinch'' description of the flow is derived for regime B of the operation of a magnetoplasma compressor. The derivation is based on the two-fluid dissipationless model in the approximation of a slowly varying stream. The potential and current distributions of the theoretical models are compared with experiment.

  12. Energy saving screw compressor technology; Energiebesparende schroefcompressortechnologie

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, A. [RefComp, Lonigo (Italy); Neus, M. [Delta Technics Engineering, Breda (Netherlands)


    Smart solutions to reduce the energy consumption are continuously part of investigation in the refrigeration technology. This article subscribed the technology on which way energy can be saved at the operation of screw compressors which are used in air conditioners and refrigerating machinery. The combination of frequency control and Vi-control (intrinsic volumetric ratio) such as researched in the laboratory of RefComp is for the user attractive because the energy efficiency during part load operation is much better. Smart uses of thermodynamics, electric technology and electronic control are the basics of these applications. According to the manufacturer's information it is possible with these new generation screw compressors to save approx. 26% energy in comparison with the standard screw compressor. [Dutch] In dit artikel wordt de technologie omschreven waarmee veel energie bespaard kan worden bij schroefcompressoren die worden gebruikt in airconditioningsystemen en koel- en vriesinstallaties. De combinatie van frequentieregeling en Vi- regeling (Vi is de intrinsieke volumetrische verhouding) zoals onderzocht in het laboratorium van RefComp biedt de gebruiker veel voordelen doordat de energie-efficintie van de compressor tijdens deellast enorm wordt verbeterd. Slim gebruik van thermodynamika, elektrotechniek en elektronica vormen de basis van deze toepassing. Volgens de fabrikant kan met deze nieuwe generatie schroefcompressoren circa 26 procent op het energiegebruik tijdens deellast worden bespaard in vergelijking met de standaard serie schroefcompressoren.

  13. Positive feedback stabilization of centrifugal compressor surge

    NARCIS (Netherlands)

    Willems, Frank; Heemels, W.P.M.H.; de Jager, Bram; Stoorvogel, Antonie Arij

    Stable operation of axial and centrifugal compressors is limited towards low mass flows due to the occurrence of surge. The stable operating region can be enlarged by active control. In this study, we use a control valve which is fully closed in the desired operating point and only opens to

  14. Compressor Foundation Analysis Tool(COFANTO)

    NARCIS (Netherlands)

    Eijk, A.; Lentzen, S.S.K; Zuada Coelho, B.E.; Galanti, F.M.B.


    Reciprocating compressors are generally supported on a heavy concrete foundation. In spite of the large inertia and stiffness of the foundation, problems can occur due to interaction between the mechanical installation and the foundation. Two types of problems may occur. In the first type, the

  15. Fault detection and diagnosis for refrigerator from compressor sensor (United States)

    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 identified 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.

  16. Experimental validation of mathematical model for small air compressor

    Directory of Open Access Journals (Sweden)

    Tuhovčák Ján


    Full Text Available Development process of reciprocating compressors can be simplified by using simulation tools. Modelling of a compressor requires a trade-off between computational effort and accuracy of desired results. This paper presents experimental validation of the simulation tool, which can be used to predict compressor behaviour under different working conditions. The mathematical model provides fast results with very good accuracy, however the model must be calibrated for a certain type of compressor. Small air compressor was used to validate an in-house simulation tool, which is based on mass and energy conservation in a control volume. The simulation tool calculates pressure and temperature history inside the cylinder, valve characteristics, mass flow and heat losses during the cycle of the compressor. A test bench for the compressor consisted of pressure sensors on both discharge and suction side, temperature sensor on discharge side and flow meter with calorimetric principle sensor.

  17. High Sensitive Methods for Health Monitoring of Compressor Blades and Fatigue Detection

    Directory of Open Access Journals (Sweden)

    Mirosław Witoś


    Full Text Available The diagnostic and research aspects of compressor blade fatigue detection have been elaborated in the paper. The real maintenance and overhaul problems and characteristic of different modes of metal blade fatigue (LCF, HCF, and VHCF have been presented. The polycrystalline defects and impurities influencing the fatigue, along with their related surface finish techniques, are taken into account. The three experimental methods of structural health assessment are considered. The metal magnetic memory (MMM, experimental modal analysis (EMA and tip timing (TTM methods provide information on the damage of diagnosed objects, for example, compressor blades. Early damage symptoms, that is, magnetic and modal properties of material strengthening and weakening phases (change of local dislocation density and grain diameter, increase of structural and magnetic anisotropy, have been described. It has been proven that the shape of resonance characteristic gives abilities to determine if fatigue or a blade crack is concerned. The capabilities of the methods for steel and titanium alloy blades have been illustrated in examples from active and passive experiments. In the conclusion, the MMM, EMA, and TTM have been verified, and the potential for reliable diagnosis of the compressor blades using this method has been confirmed.

  18. A theoretical and experimental study of a novel refrigerant compressor (United States)

    Eames, I. W.

    A refrigerant compressor concept was envisaged consisting of a small scale centrifugal compressor driven by a high frequency induction motor on a common shaft with an impeller supported in aerodynamic bearings. The combination of state-of-the-art compressor, bearing and motor technologies potentially provides refrigerator designers with improved system performance and better compressor reliability with significant reductions in weight and physical size at reduced capital and running costs. A detailed description of the prototype compressor unit is included. The concept is compared with conventional compressor systems, and key areas of research requiring detailed investigation are identified. The following are described and/or evaluated: (1) the results of a literature survey into performance of centrifugal compressors; (2) the electric motor; (3) an investigation into the design of the drive shaft and bearing assemblies; (4) external and internal sources of machine vibration; (5) the manufacture of the prototype compressor unit; (6) testing of the compressor unit; (7) development problems encountered during testing; and (8) a computer simulation study of the behavior of a refrigeration system incorporating the prototype compressor. Aspects of the manufacture considered include surface finishes, tolerancing, heat treatments, and balancing processes.

  19. Modification of a compressor performance test bench for liquid slugging observation in refrigeration compressors (United States)

    Ola, Max; Thomas, Christiane; Hesse, Ullrich


    Compressor performance test procedures are defined by the standard DIN EN 13771, wherein a variety of possible calorimeter and flow rate measurement methods are suggested. One option is the selection of two independent measurement methods. The accuracies of both selected measurement methods are essential. The second option requires only one method. However the measurement accuracy of the used device has to be verified and recalibrated on a regular basis. The compressor performance test facility at the Technische Universitaet Dresden uses a calibrated flow measurement sensor, a hot gas bypass and a mixed flow heat exchanger. The test bench can easily be modified for tests of various compressor types at different operating ranges and with various refrigerants. In addition, the modified test setup enables the investigation of long term liquid slug and its effects on the compressor. The modification comprises observational components, adjustments of the control system, safety measures and a customized oil recirculation system for compressors which do not contain an integrated oil sump or oil level regulation system. This paper describes the setup of the test bench, its functional principle, the key modifications, first test results and an evaluation of the energy balance.

  20. Properties of Refrigerant Affect Compressor Design


    Bukac, Hubert


    The paper examines selected thermodynamic properties of commonly used refrigerants and how they may affect design of a compressor. Among those properties are volumetric capacity, system pressure difference, system compression ratio, isentropic coefficient of performance, gas density, temperature of discharge gas, velocity of sound etc. The is made on the scale of evaporating temperatures from –40 oC to 30 oC, and condensing temperature 40.5 oC. The temperature of gas entering suction port is ...

  1. Combined cold compressor/ejector helium refrigerator (United States)

    Brown, Donald P.


    A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

  2. New concept single screw compressors and their manufacture technology (United States)

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


    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.

  3. Small variable speed hermetic reciprocating compressors for domestic refrigerators

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.


    This paper contains both a theoretical and experimental investigation of some of the fundamental characteristics of a smal variable speed hermetic reciprocating compressor intended for application in domestic refrigeration. The results of a previously published simulation model for variable speed...... compressors are compared with experimental results obtained in a compressor test bench. The influence of speed on compressor performance is discussed with focus on valve modelling and internal thermal phenomena. Further plans for development and validation of the model as well as experimental investigations...

  4. Development of an adsorption compressor for use in cryogenic refrigeration (United States)

    Schember, Helen R.


    A new compressor with no moving parts has been developed which is able to supply a source of high-pressure gas to a Joule-Thompson based cryogenic refrigerator. The compressor relies on a newly implemented combination of high-surface-area Saran carbon (sorbent) and krypton gas (working fluid). In addition, an integral gas-gap heat switch is used to provide improved overall efficiency. A prototype compressor has been designed, built, and tested as a part of the Jet Propulsion Laboratory effort in sorption refrigeration. Performance data from the prototype unit described here demonstrate successful compressor performance and good agreement with theoretical predictions.

  5. Critical Speed Measurements in the Tevatron Cold Compressors (United States)

    DeGraff, B.; Bossert, R.; Martinez, A.; Soyars, W. M.


    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high energy operations. Nominal operating range for these compressors is 43,000 to 85,000 rpm. Past foil bearing failures prompted investigation to determine if critical speeds for operating compressors fall within operating range. Data acquisition hardware and software settings will be discussed for measuring liftoff, first critical and second critical speeds. Several tests provided comparisons between an optical displacement probe and accelerometer measurements. Vibration data and analysis of the 20 Tevatron ring cold compressors will be presented.

  6. Steel making

    CERN Document Server

    Chakrabarti, A K


    "Steel Making" is designed to give students a strong grounding in the theory and state-of-the-art practice of production of steels. This book is primarily focused to meet the needs of undergraduate metallurgical students and candidates for associate membership examinations of professional bodies (AMIIM, AMIE). Besides, for all engineering professionals working in steel plants who need to understand the basic principles of steel making, the text provides a sound introduction to the subject.Beginning with a brief introduction to the historical perspective and current status of steel making together with the reasons for obsolescence of Bessemer converter and open hearth processes, the book moves on to: elaborate the physiochemical principles involved in steel making; explain the operational principles and practices of the modern processes of primary steel making (LD converter, Q-BOP process, and electric furnace process); provide a summary of the developments in secondary refining of steels; discuss principles a...

  7. Physics based modeling of axial compressor stall (United States)

    Zaki, Mina Adel


    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

  8. Helium compressors for closed-cycle, 4.5-Kelvin refrigerators (United States)

    Hanson, T. R.


    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.

  9. Air Compressor Driving with Synchronous Motors at Optimal Parameters

    Directory of Open Access Journals (Sweden)

    Iuliu Petrica


    Full Text Available In this paper a method of optimal compensation of the reactive load by the synchronous motors, driving the air compressors, used in mining enterprises is presented, taking into account that in this case, the great majority of the equipment (compressors, pumps are generally working a constant load.

  10. Compressor Study to Meet Large Civil Tilt Rotor Engine Requirements (United States)

    Veres, Joseph P.


    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.

  11. High Efficiency Pneumatic Systems Compressors Hydrodynamics and Termodynamics Process Research

    Directory of Open Access Journals (Sweden)

    Paulius Bogdevičius


    Full Text Available The paper analyzes pneumatic system, which consists of three piston compressors, pipes and reciever. Designed two cylinder piston compressor with an asynchronous electric motor mathematical model. In the mathematical model has been estimated rod mechanism geometry and kinematic parameters also hudrodynamics and thermodynamic processes going in the cylinders. Also there were made mathematical experiment and presented the results of it.

  12. Design and Construction of a Scroll Compressor of an Automobile ...

    African Journals Online (AJOL)


    Design and Construction of a Scroll Compressor of an Automobile Air Conditioning. System. AKPOBI, JA; AJAYI, O I. Production Engineering Department, University of Benin, Benin City, Nigeria. ABSTRACT: This work focuses on the design and manufacture of a scroll compressor used in an automobile air conditioning ...

  13. Centrifugal Compressors, Flow Phenomena and Performance. (United States)


    compressors". February 1977. 39 PAPAILIOU K.D., VOUILLARMET A. & BOIS G. "Analyse monodimensionnelle d’un 6tage de compresseur centrifuge". Contrat Creusot...mouvemant at d’Anargie s𔄀crivent (2)ew + a Co travail a Mt .1 fectul scue contrat DET. 5-2 avec D. *temps, fmasse volumique du fluide, ~,vitesse relative A...12)) n’eat plus enti~irement inatationnaire, d’oi lIa d~no- mination de pseudo-instationnaire. Cette modification implique une diminution du noinbre

  14. Maisotsenko cycle applications for multistage compressors cooling (United States)

    Levchenko, D.; Yurko, I.; Artyukhov, A.; Baga, V.


    The present study provides the overview of Maisotsenko Cycle (M-Cycle) applications for gas cooling in compressor systems. Various schemes of gas cooling systems are considered regarding to their thermal efficiency and cooling capacity. Preliminary calculation of M-cycle HMX has been conducted. It is found that M-cycle HMX scheme allows to brake the limit of the ambient wet bulb temperature for evaporative cooling. It has demonstrated that a compact integrated heat and moisture exchange process can cool product fluid to the level below the ambient wet bulb temperature, even to the level of dew point temperature of the incoming air with substantially lower water and energy consumption requirements.

  15. Development of Refrigeration Hermetic Compressors Adapt to Starting Performance (United States)

    Matsushima, Masatoshi; Nomura, Tomohiro; Murata, Mitsuru

    Motors that occupy the most part of refrigerating hermetic compressors must be small sized, lightened, high efficient and reducted costs. To achieve these objects, we need to investigate torque of compressors at the starting time and develop new motors with torque adapt to it. In this report, we research on high temperature reciprocating compressors that begin to rotate in the condition of pressure balanced and that torque of one rotation sharply fluctuates. We measure pressure fluctuation inside the cylinder and rotational speed of motors from beginning to rotate to full speed. After that we calculate torque of compressors that is, torque necessary to motors. As a result, we put to use condenser run motors useless starting condenser and voltage relay. Eventually we could develop compressors with better starting performance, high efficiency, small size, light weight and cost reduction.

  16. Numerical Investigation of Flow in a Centrifugal Compressor (United States)

    Grishin, Yu. A.; Bakulin, V. N.


    With the use of the domestic software suite of computational hydrodynamics Flow Vision based on application of the method of control volumes, numerical simulation of air composition and delivery by a centrifugal compressor employed for supercharging a piston engine has been carried out. The head-flow characteristics of the compressor, as well as the 3D fields of flow velocity and pressure distributions in the elements of the compressor flow passage, including the interblade channels of the impeller, have been obtained for various regimes. In the regimes of diminished air flow rate, surging phenomena are identified, characterized by a return flow. The application of the technique of numerical experiment will make it possible from here on to carry out design optimization of the compressor flow passage profile and thus to improve its basic characteristics — the degree of pressure increase, compressed air flow rate, and the efficiency — as well as to reduce the costs of the development and production of compressors.

  17. A conjugate heat transfer analysis of a hermetic reciprocating compressor (United States)



    Thermodynamic efficiency of a household refrigeration compressor is considerably affected by superheating that occurs inside the compressor. This phenomenon can be defined as the temperature increment of the refrigerant before entering the compression volume. On its flow path; refrigerant gains heat from suction pipe, suction muffler, suction chamber and related compressor components, which are at higher temperatures. In purpose of investigating conjugated heat transfer mechanism inside a hermetic reciprocating compressor a detailed numerical model is presented. The numerical conjugate heat and flow model is formed both with fluid domain (refrigerant) and solid domain (compressor components). Effects of using different materials on temperature distribution of some key components such as the crankcase, cylinder head and the valve plate are investigated. In addition to steady state analysis, transient CFD analysis is performed in order to understand fluid flow characteristics and its influence on superheating of the refrigerant.

  18. Heat Transfer Simulation for Reciprocating Compressor with Experimental Validation (United States)

    Zhou, Ruixin; Guo, Bei; Chen, Xiaole; Tuo, Jinliang; Wu, Rui; Fagotti, Fabian; Zhao, Yali; Yang, Song; Xu, Bo


    The efficiency of reciprocating compressor can be influenced by heat transfer and the reliability can be also affected by the temperature distribution in compressor. In consideration of the complex relationship of heat transfer, the compressor is divided into six control volumes including the suction muffler, the cylinder, the discharge chamber, the discharge muffler, the discharge line and the compressor shell. The steady state energy balance equations of the open system for each control volume are built up after the crankshaft rotates one cycle. The heat flux of the cylinder is calculated by the existing correlation. The heat transfer coefficient correlations in energy equations are chosen in references and revised by experimental results. Three same type reciprocating compressors used in R290 system installed with themocouples are tested under some planed conditions in order to ensure accuracy. The simulation results are compared with the experimental results. It shows that the simplified method presented in this paper is effective.

  19. Small oil-free CO{sub 2}-compressor

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, H.


    This report for the Swiss Federal Office of Energy (SFOE) describes a project that was to prove the feasibility of constructing a small, oil-free, semi-hermetic, piston-type CO{sub 2} compressor for use in supercritical heat pump applications with large temperature spans. The design and manufacture of a functional model of such a compressor for use in domestic hot water heating applications is described. The results of performance tests made on the compressor, including tests over the full range of speed and pressure, are presented. Estimates are made of the costs for the series-manufacture of a modified design. The author proposes this CO{sub 2} compressor technology as a possible alternative to oil-lubricated compressors in the automotive air-conditioning and domestic hot water areas as well as in industrial applications where oil-free compression is a must.


    Directory of Open Access Journals (Sweden)

    Adhimoulame Kalaisselvane


    Full Text Available Supercharging is a process which is used to improve the performance of an engine by increasing the specific power output whereas exhaust gas recirculation reduces the NOx produced by engine because of supercharging. In a conventional engine, supercharger functions as a compressor for the forced induction of the charge taking mechanical power from the engine crankshaft. In this study, supercharging is achieved using a jet compressor. In the jet compressor, the exhaust gas is used as the motive stream and the atmospheric air as the propelled stream. When high pressure motive stream from the engine exhaust is expanded in the nozzle, a low pressure is created at the nozzle exit. Due to this low pressure, atmospheric air is sucked into the expansion chamber of the compressor, where it is mixed and pressurized with the motive stream. The pressure of the mixed stream is further increased in the diverging section of the jet compressor. A percentage volume of the pressurized air mixture is then inducted back into the engine as supercharged air and the balance is let out as exhaust. This process not only saves the mechanical power required for supercharging but also dilutes the constituents of the engine exhaust gas thereby reducing the emission and the noise level generated from the engine exhaust. The geometrical design parameters of the jet compressor were obtained by solving the governing equations using the method of constant rate of momentum change. Using the theoretical design parameters of the jet compressor, a computational fluid dinamics analysis using FLUENT software was made to evaluate the performance of the jet compressor for the application of supercharging an IC engine. This evaluation turned out to be an efficient diagnostic tool for determining performance optimization and design of the jet compressor. A jet compressor was also fabricated for the application of supercharging and its performance was studied.

  1. Novel Long Stroke Reciprocating Compressor for Energy Efficient Jaggery Making (United States)

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


    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.

  2. Factory acceptance of the compressor skids at Samifi-Babcock. All pictures show the second stage compressor skid.

    CERN Multimedia

    G. Perinic


    Most recent pictures taken during the factory acceptance of the compressor skids at Samifi-Babcock. All pictures show the second stage compressor skid. Picture two was taken during the leak tests and shows all the pockets around flanges and valves.

  3. High Efficiency Centrifugal Compressor for Rotorcraft Applications (United States)

    Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.


    The report "High Efficiency Centrifugal Compressor for Rotorcraft Applications" documents the work conducted at UTRC under the NRA Contract NNC08CB03C, with cost share 2/3 NASA, and 1/3 UTRC, that has been extended to 4.5 years. The purpose of this effort was to identify key technical barriers to advancing the state-of-the-art of small centrifugal compressor stages; to delineate the measurements required to provide insight into the flow physics of the technical barriers; to design, fabricate, install, and test a state-of-the-art research compressor that is representative of the rear stage of an axial-centrifugal aero-engine; and to acquire detailed aerodynamic performance and research quality data to clarify flow physics and to establish detailed data sets for future application. The design activity centered on meeting the goal set outlined in the NASA solicitation-the design target was to increase efficiency at higher work factor, while also reducing the maximum diameter of the stage. To fit within the existing Small Engine Components Test Facility at NASA Glenn Research Center (GRC) and to facilitate component re-use, certain key design parameters were fixed by UTRC, including impeller tip diameter, impeller rotational speed, and impeller inlet hub and shroud radii. This report describes the design effort of the High Efficiency Centrifugal Compressor stage (HECC) and delineation of measurements, fabrication of the compressor, and the initial tests that were performed. A new High-Efficiency Centrifugal Compressor stage with a very challenging reduction in radius ratio was successfully designed, fabricated and installed at GRC. The testing was successful, with no mechanical problems and the running clearances were achieved without impeller rubs. Overall, measured pressure ratio of 4.68, work factor of 0.81, and at design exit corrected flow rate of 3 lbm/s met the target requirements. Polytropic efficiency of 85.5 percent and stall margin of 7.5 percent were

  4. Compressor Stability Enhancement Using Discrete Tip Injection (United States)

    Suder, Kenneth L.; Hathaway, Michael D.; Thorp, Scott A.; Strazisar, Anthony J.; Bright, Michelle B.


    Mass injection upstream of the tip of a high-speed axial compressor rotor is a stability enhancement approach known to be effective in suppressing small in tip-critical rotors. This process is examined in a transonic axial compressor rotor through experiments and time-averaged Navier-Stokes CFD simulations. Measurements and simulations for discrete injection are presented for a range of injection rates and distributions of injectors around the annulus. The simulations indicate that tip injection increases stability by unloading the rotor tip and that increasing injection velocity improves the effectiveness of tip injection. For the tested rotor, experimental results demonstrate that at 70 percent speed the stalling flow coefficient can be reduced by 30 percent using an injected mass- flow equivalent to 1 percent of the annulus flow. At design speed, the stalling flow coefficient was reduced by 6 percent using an injected mass-fiow equivalent to 2 percent of the annulus flow. The experiments show that stability enhancement is related to the mass-averaged axial velocity at the tip. For a given injected mass-flow, the mass-averaged axial velocity at the tip is increased by injecting flow over discrete portions of the circumference as opposed to full-annular injection. The implications of these results on the design of recirculating casing treatments and other methods to enhance stability will be discussed.

  5. 14 CFR 33.27 - Turbine, compressor, fan, and turbosupercharger rotors. (United States)


    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine, compressor, fan, and... Turbine, compressor, fan, and turbosupercharger rotors. (a) Turbine, compressor, fan, and... affect turbine, compressor, fan, and turbosupercharger rotor structural integrity will not be exceeded in...

  6. Modeling and control of surge and rotating stall in compressors

    Energy Technology Data Exchange (ETDEWEB)

    Gravdahl, Jan Tommy


    Compressors are used in power generation and a variety of other applications. This thesis contains new results in the field of modeling and control of rotating stall and surge in compressors. A close coupled valve is included in the Moore-Greitzer compression system model and controllers for both surge and rotating stall is derived using backstepping. Disturbances, constant and time varying, are then taken into account, and non-linear controllers are derived. Stability results are given. Then, passivity is used to derive a simple surge control law for the closed coupled valve. This propositional control law is shown to stabilize the system even in the presence of time varying disturbances in mass flow and pressure. A novel model for an axial compression system with non-constant compressor speed is derived by extending the Moore-Greitzer model. Rotating stall and surge is studied in connection with acceleration of the compressor. Finally, a model for a centrifugal compression system with time varying compressor speed is derived. The variable speed compressor characteristic is derived based on energy losses in the compressor components. Active control of surge in connection with varying speed is studied. Semi-global exponential stability of the compression system with both surge and speed control is proven. 103 refs., 38 figs., 5 tabs.

  7. Pressure field study of the Tevatron cold compressors

    Energy Technology Data Exchange (ETDEWEB)

    Klebaner, A.L.; Martinez, A.; Soyars, W.M.; Theilacker, J.C.; /Fermilab


    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. The compressor is designed to pump 60 g/sec of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/sec. Operating speeds are between 40 and 95 krpm, with a speed of 80 krpm at the design point. Different heat loads and magnet quench performance of each of the twenty-four satellite refrigerators dictates different process pressure and flow rates of the cold compressors. Reducing the process flow rate can cause the centrifugal cold compressor to stop pumping and subsequently surge. Tests have been conducted at the Cryogenic Test Facility at Fermilab to map the pressure field and appropriate efficiency of the IHI hydrodynamic cold compressor. The information allows tuning of each of the twenty-four Tevatron satellite refrigerators to avoid cold compressor operation near the surge and choke lines. A new impeller has also been tested. The Tevatron cold compressor pressure field and efficiency data with the new impeller are presented in this paper.

  8. Pressure Field Study of the Tevatron Cold Compressors (United States)

    Klebaner, A. L.; Martinez, A.; Soyars, W. M.; Theilacker, J. C.


    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations. The compressor is designed to pump 60 g/sec of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/sec. Operating speeds are between 40,000 and 95,000 rpm, with a speed of 80,000 rpm at the design point. Different heat loads and magnet quench performance of each of the twenty-four satellite refrigerators dictates different process pressure and flow rates of the cold compressors. Reducing the process flow rate can cause the centrifugal cold compressor to stop pumping and subsequently surge. Tests have been conducted at the Cryogenic Test Facility at Fermilab to map the pressure field and appropriate efficiency of the IHI hydrodynamic cold compressor. The information allows tuning of each of the twenty-four Tevatron satellite refrigerators to avoid cold compressor operation near the surge and choke lines. A new impeller has also been tested. The Tevatron cold compressor pressure field and efficiency data with the new impeller are presented in this paper.

  9. Surge Recovery Techniques for the Tevatron Cold Compressors (United States)

    Martinez, A.; Klebaner, A. L.; Makara, J. N.; Theilacker, J. C.


    The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, made by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations. The compressor is designed to pump 60 g/s of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/s and operating speeds between 40 and 95 krpm. Since initial commissioning in 1993, Tevatron transient conditions such as quench recovery have led to multiple-location machine trips as a result of the cold compressors entering the surge regime. Historically, compressors operating at lower inlet pressures and higher speeds have been especially susceptible to these machine trips and it was not uncommon to have multiple compressor trips during large multiple-house quenches. In order to cope with these events and limit accelerator down time, surge recovery techniques have been implemented in an attempt to prevent the compressors from tripping once the machine entered this surge regime. This paper discusses the different methods of surge recovery that have been employed. Data from tests performed at the Cryogenic Test Facility at Fermilab as well as actual Tevatron operational data were utilized. In order to aid in the determination of the surge region, a full mapping study was undertaken to characterize the entire pressure field of the cold compressor. These techniques were then implemented and tested at several locations in the Tevatron with some success.

  10. Design Method for Channel Diffusers of Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    Mykola Kalinkevych


    Full Text Available The design method for channel diffusers of centrifugal compressors, which is based on the solving of the inverse problem of gas dynamics, is presented in the paper. The concept of the design is to provide high pressure recovery of the diffuser by assuming the preseparation condition of the boundary layer along one of the channel surfaces. The channel diffuser was designed with the use of developed method to replace the vaned diffuser of the centrifugal compressor model stage. The numerical simulation of the diffusers was implemented by means of CFD software. Obtained gas dynamic characteristics of the designed diffuser were compared to the base vaned diffuser of the compressor stage.

  11. Turbine Engine with Differential Gear Driven Fan and Compressor (United States)

    Suciu, Gabriel L. (Inventor); Pagluica, Gino J. (Inventor); Duong, Loc Quang (Inventor); Portlock, Lawrence E. (Inventor)


    A gas turbine engine provides a differential gear system coupling the turbine to the bypass fan and the compressor. In this manner, the power/speed split between the bypass fan and the compressor can be optimized under all conditions. In the example shown, the turbine drives a sun gear, which drives a planet carrier and a ring gear in a differential manner. One of the planet carrier and the ring gear is coupled to the bypass fan, while the other is coupled to the compressor.

  12. Expert system for compressor maintenance support; Sistema especialista para apoio a manutencao de compressores

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jonny Carlos da [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica; Caletti, Luciano [KEOHPS - Knowledge Engineering on Hydraulic and Pneumatic System, SC (Brazil); Luna, Paulo de T.M. [Universidade Regional de Blumenau - FURB, SC (Brazil)


    The performance of critical machines in industrial processes, such as compressors used in industrial plants, is fundamental for overall company operation. In this context, it becomes strategic the application of methods and tools to support the operation and maintenance of the most relevant process equipment. Among these computational tools are the Expert Systems, which aim to emulate the decision making process of human experts in a specific knowledge domain. In Oil and Gas domain, an example of such tools is the SEGRED project, which combines expert system techniques with dynamic simulation of transport and distribution natural gas networks. The SECOMP project, Expert System for Compressor Maintenance, is considered a spin-off of the SEGRED. Its objective is to develop an expert system to support maintenance activities, aiming to increase reliability, improve performance and reduce maintenance and operational costs. This article presents the first phase of the SECOMP project, which is related to the development of an expert system prototype for corrective maintenance of natural gas reciprocating compressors. The paper discusses the context of this knowledge domain, the prototype development and its potential contribution in an industrial environment. (author)

  13. Performance Characteristics of a Refrigerator-Freezer with Parallel Evaporators using a Linear Compressor


    Min, Byungchae; Song, Sangjin; Noh, Kiyoul; Kim, Geonwoo; Yoon, Teaseung; Na, Sangkyung; Song, Sanghoon; Yang, Jangsik; Choi, Gyungmin; Kim, Duckjool


    A linear compressor for a domestic refrigerator-freezer has energy saving potential compared with a reciprocating compressor because of a low friction loss and free piston system. A linear compressor can control the piston stroke since it does not have mechanical restriction of piston movement. Therefore, the energy consumption of a domestic refrigerator-freezer using a linear compressor can be reduced by changing the cooling capacity of the compressor. In order to investigate the performance...

  14. Repulsive Interaction of Sulfide Layers on Compressor Impeller Blades Remanufactured Through Plasma Spray Welding (United States)

    Chang, Y.; Zhou, D.; Wang, Y. L.; Huang, H. H.


    This study investigated the repulsive interaction of sulfide layers on compressor impeller blades remanufactured through plasma spray welding (PSW). Sulfide layers on the blades made of FV(520)B steel were prepared through multifarious corrosion experiments, and PSW was utilized to remanufacture blade specimens. The specimens were evaluated through optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy, 3D surface topography, x-ray diffraction, ImageJ software analysis, Vicker's micro-hardness test and tensile tests. Results showed a large number of sulfide inclusions in the fusion zone generated by sulfide layers embodied into the molten pool during PSW. These sulfide inclusions seriously degraded the mechanical performance of the blades remanufactured through PSW.

  15. Gas turbine engine with supersonic compressor (United States)

    Roberts, II, William Byron; Lawlor, Shawn P.


    A gas turbine engine having a compressor section using blades on a rotor to deliver a gas at supersonic conditions to a stator. The stator includes one or more of aerodynamic ducts that have converging and diverging portions for deceleration of the gas to subsonic conditions and to deliver a high pressure gas to combustors. The aerodynamic ducts include structures for changing the effective contraction ratio to enable starting even when designed for high pressure ratios, and structures for boundary layer control. In an embodiment, aerodynamic ducts are provided having an aspect ratio of two to one (2:1) or more, when viewed in cross-section orthogonal to flow direction at an entrance to the aerodynamic duct.

  16. A theoretical and experimental study of a novel refrigerant compressor


    I. W. Eames


    The aim of this thesis is to evaluate the findings of research undertaken into the design manufacture and testing of a novel refrigeration compressor for use in packaged air conditioner units of the type used in railway passenger transport systems.

  17. Development Of A Centrifugal Hydrogen Pipeline Gas Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Di Bella, Francis A. [Concepts NREC, White River Junction, VY (United States)


    Concepts NREC (CN) has completed a Department of Energy (DOE) sponsored project to analyze, design, and fabricate a pipeline capacity hydrogen compressor. The pipeline compressor is a critical component in the DOE strategy to provide sufficient quantities of hydrogen to support the expected shift in transportation fuels from liquid and natural gas to hydrogen. The hydrogen would be generated by renewable energy (solar, wind, and perhaps even tidal or ocean), and would be electrolyzed from water. The hydrogen would then be transported to the population centers in the U.S., where fuel-cell vehicles are expected to become popular and necessary to relieve dependency on fossil fuels. The specifications for the required pipeline hydrogen compressor indicates a need for a small package that is efficient, less costly, and more reliable than what is available in the form of a multi-cylinder, reciprocating (positive displacement) compressor for compressing hydrogen in the gas industry.

  18. Vapor Compressor Driven Hybrid Two-Phase Loop Project (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will demonstrate a vapor compressor driven hybrid two-phase loop technology. The hybrid two-phase loop...

  19. Coatings for Fuel Cell Propulsion Compressor Bearings Project (United States)

    National Aeronautics and Space Administration — Fuel cell air handling systems require clean and contaminant-free inlet air, which dictates that oil-free, motorized, compressor/expander systems should be used....

  20. EFRC guidelines for vibrations in reciprocating compressor systems

    NARCIS (Netherlands)

    Eijk, A.


    One of the disadvantages of a reciprocating compressor is that it generates pulsations and vibrations, which, without limitation and proper attention during design, manufacturing, installation and operation, can lead to fatigue failures, inefficiency, capacity limitations and unsafe situations. To

  1. A Novel Plasma-Based Compressor Stall Control System Project (United States)

    National Aeronautics and Space Administration — Modern aircraft gas turbine engines utilize highly loaded airfoils in both the compressor and turbine to maximize performance while minimizing weight, cost, and...

  2. 49 CFR 178.338-17 - Pumps and compressors. (United States)


    ... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.338-17 Pumps and compressors... suction to the tank. (b) A valve or fitting made of aluminum with internal rubbing or abrading aluminum...

  3. Optimization of refrigeration system with gas-injected scroll compressor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Baolong; Shi, Wenxing; Han, Linjun; Li, Xianting [Department of Building Science, Tsinghua University, Beijing 100084 (China)


    Gas refrigerant injection has been proven as an effective method to improve the performance of the scroll compressor and its refrigeration system under high compression ratio working conditions. Much research on the injected scroll compressor and its system has been conducted, but the universal control and design method is still lacking. A model of the refrigeration system with a gas-injected scroll compressor is developed in this paper. With this model, the effects of gas injection on the system and component parameters are investigated. Based on the identified evaporator characteristics and thermodynamic analysis, a set of general principles for the design and operation of the refrigeration or heat pump system with a gas-injected scroll compressor is proposed. (author)

  4. 33 CFR 154.826 - Vapor compressors and blowers. (United States)


    ... be fitted with: (1) A detonation arrester; (2) A flame arrester; or (3) An explosion suppression...) Excessive shaft bearing temperature. (d) If a centrifugal compressor, fan, or lobe blower handles vapor in...

  5. The Study of Vibration Processes in Oil Flooded Screw Compressors

    Directory of Open Access Journals (Sweden)

    I. V. Filippov


    Full Text Available Vibration processes that accompany most of machines and mechanisms are of interest to the researcher, as a source of information about the technical condition and the nature of the business processes flow. Vibration-based diagnostics of oil flooded screw compressors allows us to estimate the deviation of their operation from the main mode in accordance with changing the settings of vibration processes.The oil flooded screw compressor transition from the main mode of operation to the abnormal one is accompanied by complex gas-dynamic phenomena i.e. the initial gaps and their decays. This leads to changes in the nature of vibration processes, prompting suggestions that there is a relationship to a change of vibration parameters and mode of compressor operation.Studies were conducted by combined method using an analytical calculation of the decay parameters of the initial discontinuity and an experimental one based on the measurement of acceleration on the body of the real oil flooded screw compressor. A virtually adequate reaction of the decay parameters of the initial gap and the peak values of vibration acceleration to the change of operation mode of oil flooded screw compressor has been received. The peak value of the vibration acceleration was selected by the method of Gating being time-coinciding with the beginning discharge phase of the oil flooded screw compressor, and therefore, with the decay time of the initial discontinuity.This indicates a large degree of hypothesis likelihood on an existing initial break in oil flooded screw compressor when operating in abnormal conditions. This work contains the study results of vibration processes and their relationship to the operating mode of the oil flooded screw compressor, which distinguish it from the other works studied vibration processes in reciprocating compressors. The vibration parameters control of operating oil flooded screw compressor allows us to create an automatic capacity control


    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Bourn; Jess W. Gingrich; Jack A. Smith


    This document is the final report for the ''Advanced Compressor Engine Controls to Enhance Operation, Reliability, and Integrity'' project. SwRI conducted this project for DOE in conjunction with Cooper Compression, under DOE contract number DE-FC26-03NT41859. This report addresses an investigation of engine controls for integral compressor engines and the development of control strategies that implement closed-loop NOX emissions feedback.

  7. Internal combustion engine for natural gas compressor operation (United States)

    Hagen, Christopher; Babbitt, Guy


    This application concerns systems and methods for compressing natural gas with an internal combustion engine. In a representative embodiment, a method is featured which includes placing a first cylinder of an internal combustion engine in a compressor mode, and compressing a gas within the first cylinder, using the cylinder as a reciprocating compressor. In some embodiments a compression check valve system is used to regulate pressure and flow within cylinders of the engine during a compression process.

  8. Multi-Temperature Heat Pump with Cascade Compressor Connection

    Directory of Open Access Journals (Sweden)

    Sit M.L.


    Full Text Available The object of the study is a multifunctional heat pump with several evaporators and condensers designed for simultaneous provision of technological processes with heat and cold. The aim of the work is the development and study of the scheme for this type of heat pumps, which ensures minimum irreversibility in the "compressor-gas coolers" chain, without the use of adjustable ejectors installed after evaporators and used as flow mixers. The obtained technical solution ensures the stabilization of the heat pump coefficient of performance (COP and prescribed thermal regimes of heat exchangers at a variable flow rate of the refrigerant. The novelty of the elaboration is inclusion a compressor of the first stage with a serially connected intermediate heat exchanger and a control valve that are located before the compressor inlet of the second stage of the heat pump, which allows to establish a rational pressure after the first stage of the compressors. A scheme is proposed for regulating the temperature at the inlet of the first stage compressors by regulating the flow through the primary circuits of the recuperative heat exchangers. The first stage compressor control system allows providing the required modes of operation of the heat pump. It is established, because of the exergetic analysis of the sections of the hydraulic circuit of heat pump located between the evaporators and gas coolers that the reduction of irreversible losses in the heat pump is ensured due to the optimal choice of the superheat value of the gas after the evaporators.

  9. Experimental performance of carbon dioxide compressor with parallel compression

    Energy Technology Data Exchange (ETDEWEB)

    Bella, Bachir; Kaemmer, Norbert [Emerson Climate Technologies GmbH, Aachen (Germany)


    Carbon dioxide (CO2) was proposed in the recent years as a natural fluid to replace the HFCs in refrigeration applications. Its implementation in refrigeration, first in subcritical and recently in transcritical systems is becoming a technology of increasing importance. Trans-critical CO2 system presents lower COP compared to HFCs systems when the ambient temperature is high. Reciprocating compressors with two compression stages having a vapor injection port (VI) have been proposed for parallel compression to improve the efficiency of the system. Many publications have been presented to explain the application advantage but experimental data are lacking to support the theoretical analysis. The work presented here highlight the advantage of the parallel compresion and explains the experimental tests carried-out on a reciprocating prototype with carbon dioxide working with two compression stages (parallel compression) and finally discusses the experimental results. The compressor is a semi-hermetic four cylinders compressor with one compression chamber (cylinder) dedicated to the parallel compression. The tests was performed on hot gas by-pass cycle at -10 C evaporating temperature varying the intermediate and discharge pressures. The experimental result shows the performance at different operating conditions varying the intermediate pressure. It highlights the influence of the intermediate pressure on the efficiency of the compressor and the system. The intermediate pressure influences the volumetric efficiency of the compressor and consequently the COP of the system. Finally, a system efficiency comparison between this configuration and dedicated compressor for parallel compression have been evaluated.

  10. The New Performance Calculation Method of Fouled Axial Flow Compressor

    Directory of Open Access Journals (Sweden)

    Huadong Yang


    Full Text Available Fouling is the most important performance degradation factor, so it is necessary to accurately predict the effect of fouling on engine performance. In the previous research, it is very difficult to accurately model the fouled axial flow compressor. This paper develops a new performance calculation method of fouled multistage axial flow compressor based on experiment result and operating data. For multistage compressor, the whole compressor is decomposed into two sections. The first section includes the first 50% stages which reflect the fouling level, and the second section includes the last 50% stages which are viewed as the clean stage because of less deposits. In this model, the performance of the first section is obtained by combining scaling law method and linear progression model with traditional stage stacking method; simultaneously ambient conditions and engine configurations are considered. On the other hand, the performance of the second section is calculated by averaged infinitesimal stage method which is based on Reynolds’ law of similarity. Finally, the model is successfully applied to predict the 8-stage axial flow compressor and 16-stage LM2500-30 compressor. The change of thermodynamic parameters such as pressure ratio, efficiency with the operating time, and stage number is analyzed in detail.

  11. Impact of inlet coherent motions on compressor performance (United States)

    Forlese, Jacopo; Spoleti, Giovanni


    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.

  12. Crack Propagation in Compressor Rotor Blade (United States)


    following equation, see Reshetov and Levina (1965)  (28) where c = 0.0014 for ground/ground steel surfaces and m = 0.5 for most metallic...D. N and Levina Z. M., Machine Design for Contact Stiffness, Machines and Tooling, vol. 36, 1965, p. 15 Rao, J. S., Fracture Mechanics Analysis of

  13. Tool steels

    DEFF Research Database (Denmark)

    Højerslev, C.


    On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness andtoughness, the primary carbides provide...... resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...... serves primarily two purpose (i) to improve the hardenabillity and (ii) to provide harder and thermally more stable carbides than cementite. Assuming proper heattreatment, the properties of a tool steel depends on the which alloying elements are added and their respective concentrations....

  14. Phase-coded pulse expander-compressor (United States)

    Lewis, B. L.


    A pulse expansion and compression system, especially useful for radar ranging, comprising a pulse coder for expanding an input pulse and a pulse compressor of the matched-filter type. The coder consists of a plurality of delay stages into which the input pulse is fed, a discrete Fourier transform (DFT) circuit to which the output signals of the delay stages are fed by way of respective phase weights and for which every other frequency port is inverted prior to entry to a time-dispersion-means (TDM) comprising an arrangement of adders interconnected by delay stages for differently delaying the output signals from the DFT. The adders are connected in N/2-fold cyclically permutated order to the frequency ports, where N is the number of frequency ports if that number is even, and N is the number of frequency ports less one if that number is odd. The TDM output is fed to a phase modulator and then to the transmitter. The echo signals are conjugated, time-inverted, and passed through the same DFT as the input pulse signal by way of the phase weights. The outputs of the DFT are then inverted at every other frequency port and passed through the TDM, but this time in time-inverted order. The outputs of the TDM are fed through an envelope detector to provide a cross-correlated facsimile of the original input pulse.

  15. P2 polyphase code expander-compressor (United States)

    Kretschmer, F. F.


    A pulse expansion and compression system, especially useful for radar ranging, comprising a pulse coder for expanding an input pulse and a pulse compressor of the matched-filter type. The coder consists of a plurality of delay stages into which the input pulse is fed, a discrete Fourier transform (DFT) circuit to which the output signals of the delay stages are fed by way of respective phase weights and for which every frequency port is phase-shifted prior to entry to a time-dispersion-means (TDM) comprising an arrangement of delay stages for differently delaying the output signals from the DFT. The TDM output is fed to a phase modulator and then to the transmitter. The echo signals are conjugated, time-inverted, and passed through the same DFT as the input pulse signal by way of the phase weights. The outputs of the DFT are then phase-shifted at every frequency port and passed through the TDM, but this time in time-inverted order. The outputs of the TDM are fed through an envelope detector to provide a cross-correlated facsimile of the original input pulse.

  16. P1 polyphase code expander-compressor (United States)

    Kretschmer, F. F.


    A pulse expansion and compression system, especially useful for radar ranging, comprising a pulse coder for expanding and input pulse and a pulse compressor of the matched-filter type. The coder consists of a plurality of delay stages into which the input pulse is fed, a discrete Fourier transform (DFT) circuit to which the output signals of the delay stages are fed by way of respective phase weights and for which every other frequency port is inverted prior to entry to a time-dispersion-means (TDM) comprising an arrangement of adders interconnected by delay stages for differently delaying the output signals from the DFT. The TDM output is fed to a phase modulator and then to the transmitter. The echo signals are conjugated, time-inverted, and passed through the same DFT as the input pulse signal by way of the phase weights. The outputs of the DFT are then inverted at every other frequency port and passed through the TDM, but this tme in time-inverted order. The outputs of the TDM are fed through an envelope detector to provide a cross-correlated facsimile of the original input pulse.

  17. Phase coded pulse expander-compressor (United States)

    Lewis, B. L.


    A pulse expansion and compression system, especially useful for radar ranging, comprising a pulse coder for expanding an input pulse and a pulse compressor of the matched-filter type. The coder consists of a plurality of delay stages into which the input pulse is fed, a discrete Fourier transform (DFT) circuit to which the output signals of the delay stages are fed by way of respective phase weights and for which every other frequency port is inverted prior to entry to a time-dispersion means (TDM) comprising an arrangement of adders interconnected by delay stages for differently delaying the output signals from the DFT. The TDM output is fed to a phase modulator and then to the transmitter. The echo signals are conjugated, time-inverted, and passed through the same DFT as the input pulse signal by way of the phase weights. The outputs of the DFT are then inverted at every other frequency port and passed through the TDM, but this time in time-inverted order. The outputs of the TDM are fed through an envelope detector to provide a cross-correlated facsimile of the original input pulse.

  18. Sensitization to Corrosion as Initiator of Fatigue Fracture in Compressor Blades

    Directory of Open Access Journals (Sweden)

    Vladimír CIHAL


    Full Text Available Certain failures of stainless steels interpreted purely in terms of fracture mechanisms may in fact be closely associated with previous damage caused by localized corrosion. The closeness of the link between fatigue and corrosion is documented by the case history of compressor blades made of grade 14Cr17Ni2 (X14CrNi17-2 stainless steel. Fatigue fracturing observed in areas near the blade root tended to follow intergranular pathways, indicating that some additional mechanism other than fatigue might be involved. This suspicion was confirmed by electrochemical potentiokinetic reactivation (EPR measurements in situ, which revealed sensitization to intergranular corrosion. It has been found that at the transition between the blade root and the blade proper the surfaces had been ground and polished too vigorously, heating the subcutaneous layers to within the danger zone of 400-600°C. Preferential integranular attack in these locations was the initiation mechanism that provoked a subsequent failure of the blades by fatigue fracture.

  19. NASA Glenn's Single-Stage Axial Compressor Facility Upgraded (United States)

    Brokopp, Richard A.


    NASA Glenn Research Center's Single-Stage Axial Compressor Facility was upgraded in fiscal year 2003 to expand and improve its research capabilities for testing high-speed fans and compressors. The old 3000-hp drive motor and gearbox were removed and replaced with a refurbished 7000-hp drive motor and gearbox, with a maximum output speed of 21,240 rpm. The higher horsepower rating permits testing of fans and compressors with higher pressure ratio or higher flow. A new inline torquemeter was installed to provide an alternate measurement of fan and compressor efficiency, along with the standard pressure and temperature measurements. A refurbished compressor bearing housing was also installed with bidirectional rotation capability, so that a variety of existing hardware could be tested. Four new lubrication modules with backup capability were installed for the motor, gearbox, torquemeter, and compressor bearing housing, so that in case the primary pump fails, the backup will prevent damage to the rotating hardware. The combustion air supply line for the facility inlet air system was activated to provide dry air for repeatable inlet conditions. New flow conditioning hardware was installed in the facility inlet plenum tank, which greatly reduced the inlet turbulence. The new inlet can also be easily modified to accommodate 20- or 22-in.-diameter fans and compressors, so a variety of existing hardware from other facilities (such as Glenn's 9- by 15-Foot Low-Speed Wind Tunnel) can be tested in the Single-Stage Axial Compressor Facility. An exhaust line was also installed to provide bleed capability to remove the inlet boundary layer. To improve the operation and control of the facility, a new programmable logic controller (PLC) was installed to upgrade from hardwired relay logic to software logic. The PLC also enabled the usage of human-machine interface software to allow for easier operation of the facility and easier reconfiguration of the facility controls when

  20. Measures to Control Forming of Oil in a Refrigerant Compressor (United States)

    Yanagisawa, Tadashi; Shimizu, Takashi; Fukuta, Mitsuhiro; Mizuno, Yoshihito

    Foaming of lubricating oil in a rotary compressor induces flowing out of the oil from the compressor, which deteriorates reliability of the compressor. This study investigates foaming characteristics of oil-refrigerant mixture by using an experimental apparatus which models foaming in the compressor. The experiments reveal that the foaming caused by blade rotation can be controlled by a plate which prevents a vortex from swallowing up the vapor and that the foaming caused by vapor blow can be depressed by a blow pipe extending above the mixture. Based on these results, measures to control foaming in a practical rotary compressor are investigated by using an experimental refrigerating cycle. From measurement of the foaming, it is proved that a simple cover which separates discharge blow from the mixture under a motor has a great effect of defoaming. Collection of oil which is pumped up through a shaft is also effective in decreasing the foaming. In addition, improvement of transient performance of the cycle is obtained by controlling the foaming.

  1. CFD analysis of linear compressors considering load conditions (United States)

    Bae, Sanghyun; Oh, Wonsik


    This paper is a study on computational fluid dynamics (CFD) analysis of linear compressor considering load conditions. In the conventional CFD analysis of the linear compressor, the load condition was not considered in the behaviour of the piston. In some papers, behaviour of piston is assumed as sinusoidal motion provided by user defined function (UDF). In the reciprocating type compressor, the stroke of the piston is restrained by the rod, while the stroke of the linear compressor is not restrained, and the stroke changes depending on the load condition. The greater the pressure difference between the discharge refrigerant and the suction refrigerant, the more the centre point of the stroke is pushed backward. And the behaviour of the piston is not a complete sine wave. For this reason, when the load condition changes in the CFD analysis of the linear compressor, it may happen that the ANSYS code is changed or unfortunately the modelling is changed. In addition, a separate analysis or calculation is required to find a stroke that meets the load condition, which may contain errors. In this study, the coupled mechanical equations and electrical equations are solved using the UDF, and the behaviour of the piston is solved considering the pressure difference across the piston. Using the above method, the stroke of the piston with respect to the motor specification of the analytical model can be calculated according to the input voltage, and the piston behaviour can be realized considering the thrust amount due to the pressure difference.

  2. A CFD study of Screw Compressor Motor Cooling Analysis (United States)

    Branch, S.


    Screw compressors use electric motors to drive the male screw rotor. They are cooled by the suction refrigerant vapor that flows around the motor. The thermal conditions of the motor can dramatically influence the performance and reliability of the compressor. The more optimized this flow path is, the better the motor performance. For that reason it is important to understand the flow characteristics around the motor and the motor temperatures. Computational fluid dynamics (CFD) can be used to provide a detailed analysis of the refrigerant’s flow behavior and motor temperatures to identify the undesirable hot spots in the motor. CFD analysis can be used further to optimize the flow path and determine the reduction of hot spots and cooling effect. This study compares the CFD solutions of a motor cooling model to a motor installed with thermocouples measured in the lab. The compressor considered for this study is an R134a screw compressor. The CFD simulation of the motor consists of a detailed breakdown of the stator and rotor components. Orthotropic thermal conductivity material properties are used to represent the simplified motor geometry. In addition, the analysis includes the motor casings of the compressor to draw heat away from the motor by conduction. The study will look at different operating conditions and motor speeds. Finally, the CFD study will investigate the predicted motor temperature change by varying the vapor mass flow rates and motor speed. Recommendations for CFD modeling of such intricate heat transfer phenomenon have thus been proposed.

  3. Noise evaluation of automotive A/C compressor

    Energy Technology Data Exchange (ETDEWEB)

    Metwally, Sameh M.; Khalil, Mohamed I.; Abouel-seoud, Shawki A. [Automotive and Tractors Dept., Faculty of Engineering, Helwan University, Cairo (Egypt)


    Passenger compartment's interior noise and thermal performance are essential criteria for the driving comfort of vehicles. The air-conditioning system influences both field of comfort. It creates comfortable thermal conditions. On the other hand, the noise radiation of the air-condition system's components can be annoying. The blower, the air distribution ducts and the registers affect air rush noise. In some cases, the refrigerant flow creates hissing noise. Such noise has a great influence on vehicle acoustical comfort and on overall quality perception of a vehicle Therefore, the acoustic performance of air-condition compressors become more important for passenger comfort. At engine idling and at extreme temperatures the air-condition compressor can be audible as the significant sound source. However, the aim of this paper is to quantify air-borne noise characteristics of vehicle air-condition compressor. A simulated experimental model comprises a small wooden box with dimensions of 0.5 x 0.5 x 0.5 m represented the principle of hemi-anechoic room was designed and acoustic characteristics of the sound field inside the box were determined. The air-condition compressor characteristics parameters considered in this paper are fan position and electric motor speed. In addition, a single number of the air column natural frequency is calculated. The results indicate that significant information can be obtained in order to investigate the vehicle air-condition compressor and consequently improve the vehicle interior quietness.

  4. Downhole steam generator having a downhole oxidant compressor (United States)

    Fox, Ronald L.


    Apparatus and method for generation of steam in a borehole for penetration into an earth formation wherein a downhole oxidant compressor is used to compress relatively low pressure (atmospheric) oxidant, such as air, to a relatively high pressure prior to mixing with fuel for combustion. The multi-stage compressor receives motive power through a shaft driven by a gas turbine powered by the hot expanding combustion gases. The main flow of compressed oxidant passes through a velocity increasing nozzle formed by a reduced central section of the compressor housing. An oxidant bypass feedpipe leading to peripheral oxidant injection nozzles of the combustion chamber are also provided. The downhole compressor allows effective steam generation in deep wells without need for high pressure surface compressors. Feedback preheater means are provided for preheating fuel in a preheat chamber. Preheating of the water occurs in both a water feed line running from aboveground and in a countercurrent water flow channel surrounding the combustor assembly. The countercurrent water flow channels advantageously serve to cool the combustion chamber wall. The water is injected through slotted inlets along the combustion chamber wall to provide an unstable boundary layer and stripping of the water from the wall for efficient steam generation. Pressure responsive doors are provided at the steam outlet for closing and sealing the combustion chamber from entry of reservoir fluids in the event of a flameout.

  5. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal


    Full Text Available The objective of this research work is to study the behaviour of flow at the inlet, within the blade passage and at the exit of a compressor cascade. For this purpose, a cascade with six numbers of aerofoil blades was designed and constructed. The cascade was fitted on the cascade test tunnel. Out of six blades two were instrumented for measuring the pressure distribution on the pressure and suction surface. The blades had a parabolic camber line, with a maximum camber position at 40% of the chord from the leading edge of the blade. The profile of the blade was C4, height of the blade was 160 mm, chord length was 80 mm, camber angle was 45° and stagger angle was 30°. Similarly, the length of the cascade was 300 mm, span was 160 mm, pitch was 60 mm, the actual chord of the cascade was 80 mm, the axial chord of the cascade was 70 mm, the stagger angle of the cascade was 30° and the pitch-chord ratio was 0.75. The data was taken and analyzed at −500% of the axial chord before the cascade, −25% of the axial chord before the leading edge, 25%, 50%, 75% and 150% of the axial chord from the leading edge of the blade. The readings were taken from the cascade wall to the mid span position along the pitch wise direction. The angle of incidence was also changed during the experiment and varied from i=−50°, −30°, −10° to 5°.

  6. Diagnostics of magnetoplasma compressor of compact geometry (United States)

    Purić, J.; Dojčinović, I. P.; Astashynski, V. M.; Kuraica, M. M.


    Quasistationary plasma accelerator of magnetoplasma compressor type with semitransparent electrodes operating in an ion current transfer regime has been constructed and studied. Main discharge and compression plasma flow parameters have been measured. It has been found that the current cut off limiting the increase of the parameters in the case of classical plasma accelerators operating in the electron current transfer can be avoided by switching to the ion current transfer. It was made achievable by an especially designed electrode system shielded by the magnetic field, and therefore protected of the erosion as a main reason for energy losses leading to the current crisis. Due to the electrode transparency in two stage quasistationary plasma accelerator there is no limit in the maximal current value depending only on the condenser bank input energy used in the experiment. Consequently, the compression plasma flow velocity, electron density and temperature depend only on the energy transfer efficiency from supply source to plasma. It has been concluded that the efficiency is maximal when operating in the hydrogen in comparison with other working gases (argon, nitrogen etc.). It was found that, for an imput energy of 6.4 kJ the maximal values of plasma flow velocity and electron density are of the order of ~100 km/s and ~1017cm-3, respectively. These accelerating systems are of special interest for development of new plasma technologies such as plasma solid surface modification and obtaining new materials including nano sized ones. Finally, these accelerators can be used for construction of plasma injectors to fusion devices.

  7. The change of the inlet geometry of a centrifugal compressor stage and its influence on the compressor performance (United States)

    Wang, Leilei; Yang, Ce; Zhao, Ben; Lao, Dazhong; Ma, Chaochen; Li, Du


    The impact on the compressor performance is important for designing the inlet pipe of the centrifugal compressor of a vehicle turbocharger with different inlet pipes. First, an experiment was performed to determine the compressor performance from three cases: a straight inlet pipe, a long bent inlet pipe and a short bent inlet pipe. Next, dynamic sensors were installed in key positions to collect the sign of the unsteady pressure of the centrifugal compressor. Combined with the results of numerical simulations, the total pressure distortion in the pipes, the pressure distributions on the blades and the pressure variability in the diffuser are studied in detail. The results can be summarized as follows: a bent pipe results in an inlet distortion to the compressor, which leads to performance degradation, and the effect is more apparent as the mass flow rate increases. The distortion induced by the bent inlet is not only influenced by the distance between the outlet of the bent section and the leading edge of the impeller but also by the impeller rotation. The flow fields in the centrifugal impeller and the diffuser are influenced by a coupling effect produced by the upstream inlet distortion and the downstream blocking effect from the volute tongue. If the inlet geometry is changed, the distributions and the fluctuation intensities of the static pressure on the main blade surface of the centrifugal impeller and in the diffuser are changed accordingly.

  8. A cryogenic axial-centrifugal compressor for superfluid helium refrigeration

    CERN Document Server

    Decker, L; Schustr, P; Vins, M; Brunovsky, I; Lebrun, P; Tavian, L


    CERN's new project, the Large Hadron Collider (LHC), will use superfluid helium as coolant for its high-field superconducting magnets and therefore require large capacity refrigeration at 1.8 K. This may only be achieved by subatmospheric compression of gaseous helium at cryogenic temperature. To stimulate development of this technology, CERN has procured from industry prototype Cold Compressor Units (CCU). This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating under low-pressure helium at ambient temperature. The machine has been commissioned and is now in operation. After describing basic constructional features of the compressor, we report on measured performance.

  9. Fault detection in reciprocating compressor valves under varying load conditions (United States)

    Pichler, Kurt; Lughofer, Edwin; Pichler, Markus; Buchegger, Thomas; Klement, Erich Peter; Huschenbett, Matthias


    This paper presents a novel approach for detecting cracked or broken reciprocating compressor valves under varying load conditions. The main idea is that the time frequency representation of vibration measurement data will show typical patterns depending on the fault state. The problem is to detect these patterns reliably. For the detection task, we make a detour via the two dimensional autocorrelation. The autocorrelation emphasizes the patterns and reduces noise effects. This makes it easier to define appropriate features. After feature extraction, classification is done using logistic regression and support vector machines. The method's performance is validated by analyzing real world measurement data. The results will show a very high detection accuracy while keeping the false alarm rates at a very low level for different compressor loads, thus achieving a load-independent method. The proposed approach is, to our best knowledge, the first automated method for reciprocating compressor valve fault detection that can handle varying load conditions.

  10. Effect of piping systems on surge in centrifugal compressors

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Hideaki [Products Development Center, Yokohama (Japan)


    There is a possibility that the exchange of the piping system may change the surge characteristic of a compressor. The piping system of a plant is not always the same as that of a test site. Then it is important to evaluate the effect of piping systems on surge characteristics in centrifugal compressors. Several turbochargers combined with different piping systems were tested. The lumped parameter model which was simplified to be solved easily was applied for the prediction of surge point. Surge lines were calculated with the linearlized lumped parameter model. The difference between the test and calculated results was within 10 %. Trajectory of surge cycle was also examined by solving the lumped parameter model. Mild surge and deep surge were successfully predicted. This study confirmed that the lumped parameter model was a very useful tool to predict the effect of piping systems on surge characteristics in centrifugal compressors, even though that was a simple model

  11. Genetic Algorithm Optimization of the Volute Shape of a Centrifugal Compressor

    National Research Council Canada - National Science Library

    Heinrich, Martin; Schwarze, Rüdiger


    ... is the turbocharger which helps to reduce the engine size, increase efficiency, and lower the emissions. A typical compressor of a turbocharger for passenger cars and light commercial vehicles consists of an inlet port, the compressor wheel, and the volute with an exit pipe. The compressor wheel is well understood and investigated intensively throughou...

  12. Development of a High Efficiency Compressor/Expander for an Air Cycle Air Conditioning System. (United States)


    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

  13. Compressors for turbojet engines; Verdichter fuer Turbo-Flugtriebwerke

    Energy Technology Data Exchange (ETDEWEB)

    Grieb, Hubert


    Turbocompressors for aircraft engines have many specific characteristics which have practical effects on development, design, and construction. This knowledge is presented in this book. For a better understanding of the constraints imposed on the compressor design by the aircraft engine in general and of the compressor operating conditions imposed by the jet engine in different flight conditions and operating conditions, the development of the major design and operating parameters, their interdependences and recommended combinations of design parameters are gone into. The information is based on extensive data collections of industrial development. The book discusses all compressor components and designs encountered in aircraft engines, including single-stage fans of civil auxiliary current drives, high-pressure compressors of dual-circuit, multishaft drives to two-stage radial compressors of gas generators of small shaft propulsion systems. Particular attention is given to the analytical treatment of aerodynamically or mechanically induced blade vibrations and the available analytical methods, which as a result of constant development of axial and radial compressors are getting increasingly complex. (orig.) [German] Turboverdichter fuer Flugtriebwerke haben viele spezielle Eigenschaften, die fuer die praktische technische Entwicklung, Auslegung und Konstruktion von Bedeutung sind. Diese Kenntnisse werden in diesem Buch zusammengestellt. Fuer das Verstaendnis der vom Gesamttriebwerk ausgehenden Beschraenkungen der Verdichter-Auslegungsparameter und der vom Triebwerk aufgepraegten Arbeitsbedingungen der Verdichter unter verschiedenen Flug- bzw. Betriebsbedingungen werden die Entwicklung der wichtigen Auslegungs- und Betriebsparameter, die dabei zu beachtenden gegenseitigen Abhaengigkeiten und die zu empfehlenden Kombinationen der Auslegungsparameter behandelt. Grundlage dafuer sind umfassende Datensammlungen aus der industriellen Entwicklung. Behandelt werden alle

  14. Molecular iodine laser with wide-band optical pumping by polychannel cumulative discharge of magnetoplasma compressor

    Energy Technology Data Exchange (ETDEWEB)

    Kamrukov, A.S.; Kashnikov, G.N.; Kozlov, N.P.; Kuznetsov, S.G.; Orlov, V.K.; Protasov, Yu.S.


    Lasing is achieved in iodine vapor in experiments with wide-band optical pumping by the emission of a polychannel cumulative discharge of a magnetoplasma compressor. The active medium was excited by radiation from a shock-heated plasma formed by collision and accumulation of high-velocity head-on plasma streams produced by six magnetoplasma compressors 1 arranged in groups of three on each side of discharge chamber 2. The inside diameter of the chamber was 120 mm, and length was 300 mm. Two identical cells 3 containing the active substance were placed inside the chamber parallel to its axis. The cells were made of stainless steel with three flat windows of MgF/sub 2/ through which the pumping radiation was coupled into the active medium. On the end flanges of the cells were either quartz windows for studying luminescence characteristics, or adjustable quartz mirrors to form an optical cavity (laser cells). Brightness of the shock-compressed plasma in the iodine absorption band was enhanced by a xenon atmosphere of 1 to 3 torr in the discharge chamber. The use of a cumulative discharge in low-pressure gas instead of a vacuum discharge enabled effective tuning of the plasma emission spectrum. The buffer gas in the working cells was perfluoromethane. Lasing was observed on 342.0 and 342.4 nm corresponding to transitions with vibrational numbers of 1 to 14 and 2 to 15. Lasing pulse duration at half-amplitude was 1 to 1.5

  15. Hegelian Steel

    DEFF Research Database (Denmark)

    Kjær, Poul F.


    . Developing a Hegelian inspired historical-sociological approach this paper however argues that national and transnational societies emerged simultaneously and in a co-evolutionary and mutually supportive fashion. In most European settings national societies did not become the central horizon of individuals...... of the European steel industry....

  16. Performance of Oil-Injected Scroll Compressors for Helium Refrigerators (United States)

    Shiibayashi, Masao; Izunaga, Yasushi; Sado, Shintaro

    In recent years there arises growing demand of helium liquefaction refrigerators for the magnetic resonance imaging systems, magnetically levitated vehicles and other systems using superconducting magnet. From this background, a small size, scroll type of hermetic helium compressor capable of compressing helium gas to the pressure ratio of 20 in a single stage is developed. Main features of this compressor are as follows. 1) Discharge capacity can be varied from 7 to 20 Nm3/h by changing driving motor frequency from 30 to 80 Hz. 2) The overall adiabatic efficiency showed 72%∼79% under the pressure ratio range of 11∼20 at 60 Hz using oil injection cooling device.

  17. Hermetic compressor and block expansion valve in refrigeration performance (United States)

    Santoso, Budi; Susilo, Didik Djoko; Tjahjana, D. D. D. P.


    Vehicle cabin in tropical countries requires the cooling during the day for comfort of passengers. Air conditioning machine is commonly driven by an internal combustion engine having a great power, which the conventional compressor is connected to crank shaft. The stage of research done is driving the hermetic compressor with an electric motor, and using block expansion valve. The HFC-134a was used as refrigerant working. The primary parameters observed during the experiment are pressure, temperature, and power consumption for different cooling capacities. The results show that the highest coefficient of performance (COP) and the electric power of system are 6.3 and 638 Watt, respectively.

  18. Modern controls increase compressor efficiency; Moderne Steuerungskonzepte steigern den Kompressorwirkungsgrad

    Energy Technology Data Exchange (ETDEWEB)

    Ruppelt, E. [Kaeser Kompressoren GmbH, Coburg (Germany)


    As there are various ways of controlling compressor systems it is essential to do a careful analysis before changes or new plans for a compressed air unit are executed. Such an analysis enables high-performance design of compressors, i.e. large output at low energy consumption.(orig.). [German] Angesichts der unterschiedlichen Moeglichkeiten, Kompressorensysteme zu steuern, ist es besonders wichtig, vor jeder Aenderung oder Neuplanung einer Druckluftstation eine Analyse durchzufuehren. Mit ihrer Hilfe lassen sich Druckluftstationen auf hoechste Leistung hin auslegen, also grosse Liefermenge bei niedrigem Energieverbrauch. (orig.)

  19. Theory and Simulation of CSR Microbunching in Bunch Compressors

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhirong


    CSR microbunching instability in bunch compressors is studied both analytically and numerically. The iterative solutions of the integral equation for the instability provide approximate expressions of CSR microbunching due to initial density and energy modulation, and can be applied to a series of bending systems consisting of multiple compressor chicanes and transport lines. Two similar but independent simulation methods are developed and are compared to each other as well as with theory. We determine the total gain in density modulation for all bend systems of the Linac Coherent Light Source and discuss initial conditions that start the unstable process.

  20. Statistical energy analysis for a compact refrigeration compressor (United States)

    Lim, Ji Min; Bolton, J. Stuart; Park, Sung-Un; Hwang, Seon-Woong


    Traditionally the prediction of the vibrational energy level of the components in a compressor is accomplished by using a deterministic model such as a finite element model. While a deterministic approach requires much detail and computational time for a complete dynamic analysis, statistical energy analysis (SEA) requires much less information and computing time. All of these benefits can be obtained by using data averaged over the frequency and spatial domains instead of the direct use of deterministic data. In this paper, SEA will be applied to a compact refrigeration compressor for the prediction of dynamic behavior of each subsystem. Since the compressor used in this application is compact and stiff, the modal densities of its various components are low, especially in the low frequency ranges, and most energy transfers in these ranges are achieved through the indirect coupling paths instead of via direct coupling. For this reason, experimental SEA (ESEA), a good tool for the consideration of the indirect coupling, was used to derive an SEA formulation. Direct comparison of SEA results and experimental data for an operating compressor will be introduced. The power transfer path analysis at certain frequencies made possible by using SEA will be also described to show the advantage of SEA in this application.

  1. Robust Stabilization of Jet Engine Compressor In The Presence of ...

    African Journals Online (AJOL)

    Compressors for jet engines in operation experience disturbances such as variations in the states of the system, mass flow, and pressure. These disturbances sometimes result in instabilities due to surge and stall, which adversely affect performance. In this work, first we modify the Moore and Grietzer three-state model for ...

  2. An experimental method for validating compressor valve vibration theory

    NARCIS (Netherlands)

    Habing, R.A.; Peters, M.C.A.M.


    This paper presents an experimental method for validating traditional compressor valve theory for unsteady flow conditions. Traditional valve theory considers the flow force acting on the plate and the flow rate as quasi-steady variables. These variables are related via semi-empirical coefficients

  3. Numerical Study of Unsteady Flow in Centrifugal Cold Compressor (United States)

    Zhang, Ning; Zhang, Peng; Wu, Jihao; Li, Qing

    In helium refrigeration system, high-speed centrifugal cold compressor is utilized to pumped gaseous helium from saturated liquid helium tank at low temperature and low pressure for producing superfluid helium or sub-cooled helium. Stall and surge are common unsteady flow phenomena in centrifugal cold compressors which severely limit operation range and impact efficiency reliability. In order to obtain the installed range of cold compressor, unsteady flow in the case of low mass flow or high pressure ratio is investigated by the CFD. From the results of the numerical analysis, it can be deduced that the pressure ratio increases with the decrease in reduced mass flow. With the decrease of the reduced mass flow, backflow and vortex are intensified near the shroud of impeller. The unsteady flow will not only increase the flow loss, but also damage the compressor. It provided a numerical foundation of analyzing the effect of unsteady flow field and reducing the flow loss, and it is helpful for the further study and able to instruct the designing.

  4. Cathode potential drop in the channel of a magnetoplasma compressor

    Energy Technology Data Exchange (ETDEWEB)

    Shubin, A.P.


    Calculations are carried out for the dissipationless plasma flow in the channel of a magnetoplasma compressor when there is a potential drop near the cathode. This drop appears when the current is carried by ions as the result of the disappearance of ions at the cathode.

  5. Dynamics of Xenon Plasma Streams Generated by Magnetoplasma Compressor (United States)

    Garkusha, I. E.; Chebotarev, V. V.; Hassanein, A.; Ladygina, M. S.; Marchenko, A. K.; Petrov, Yu. V.; Solyakov, D. G.; Tereshin, V. I.; Trubchaninov, S. A.; Byrka, O. V.


    The paper presents the investigations of parameters of xenon plasma streams generated by magnetoplasma compressor (MPC) of compact geometry with conical-shaped electrodes and pulsed gas supply. Discharge characteristics and dynamics of the plasma streams, generated by MPC in different operation modes are analyzed. First results of Xe plasma radiation measurements in EUV wave range, obtained with AXUV diodes are presented.

  6. Structure of compression region in a magnetoplasma compressor

    Energy Technology Data Exchange (ETDEWEB)

    Kovrov, P.E.; Morozov, A.I.


    A small-scale structure is detected in the region of the compression of the plasma stream emerging from a magnetoplasma compressor. This structure typically persists approx.10/sup -7/ sec. There are fine filamentary formations (''pinches'') in which the density is much higher than the typical density in the stream.

  7. On the design of lubricant free piston compressors

    NARCIS (Netherlands)

    Owczarek, P.


    This thesis describes the development on long lifetime and an efficient piston compressor operating in a clean environment where oil lubrication must be excluded. Particularly in cooling systems including cryocoolers the presence of oil is a well known problem. A growing number of applications of

  8. 78 FR 1162 - Cardiovascular Devices; Reclassification of External Cardiac Compressor (United States)


    ..., including cardiopulmonary resuscitation (CPR) aids, from class III devices into class II (special controls.... Automated external cardiac compressor devices are used as an adjunct to manual cardiopulmonary resuscitation... assure the safety and effectiveness of the device. II. Regulatory History of the Device On March 9, 1979...

  9. Non-traditional vibration mitigation methods for reciprocating compressor system

    NARCIS (Netherlands)

    Eijk, A.; Lange, T.J. de; Vreugd, J. de; Slis, E.J.P.


    Reciprocating compressors generate vibrations caused by pulsation-induced forces, mechanical (unbalanced) free forces and moments, crosshead guide forces and cylinder stretch forces. The traditional way of mitigating the vibration and cyclic stress levels to avoid fatigue failure of parts of the

  10. Design of new silencers for a screw compressor

    NARCIS (Netherlands)

    Lier, L.J. van; Korst, H.J.C.; Smeulers, J.P.M.


    Two screw compressors used for the recycling of waste gas showed high vibration in the discharge piping. To mitigate the vibration problems new silencers had to be designed. A great challenge was the large variation in operating conditions, especially the variation of the molecular weight of the

  11. Numerical analysis on centrifugal compressor with membrane type dryer (United States)

    Razali, M. A.; Zulkafli, M. F.; Mat Isa, N.; Subari, Z.


    Moisture content is a common phenomenon in industrial processes especially in oil and gas industries. This contaminant has a lot of disadvantages which can lead to mechanical failure DEC (Deposition, Erosion & Corrosion) problems. To overcome DEC problem, this study proposed to design a centrifugal compressor with a membrane type dryer to reduce moisture content of a gas. The effectiveness of such design has been analyzed in this study using Computational Fluid Dynamics (CFD) approach. Numerical scheme based on multiphase flow technique is used in ANSYS Fluent software to evaluate the moisture content of the gas. Through this technique, two kind of centrifugal compressor, with and without membrane type dryer has been tested. The results show that the effects of pressure on dew point temperature of the gas change the composition of its moisture content, where high value lead more condensation to occur. However, with the injection of cool dry gas through membrane type dryer in the centrifugal compressor, the pressure and temperature of moisture content as well as mass fraction of H2O in centrifugal compressor show significant reduction.

  12. On the compressor ring for the JAERI neutron science project

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Isao [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)


    (1), As long as a 1.5 GeV-8 MW linear accelerator is constructed in the JAERI neutron science center, it is quite reasonable to construct a 5 MW compressor ring as a driver of a high intensity spallation neutron source to generate pulsed neutron beams. (2), Suppression of beam loss around the compressor ring to an acceptable level is the most crucial subject to be coped with in designing a MW-class compressor ring. This subject should be successfully cleared by carefully studying and designing the overall system of accelerator and tunnel. (3), The `PSR instability` was comprehensively discussed in the NSNS workshop held at Santa Fe in March, 1997, as a remaining problem of a high intensity proton compressor ring. People of Los Alamos attributed it to an e-p instability. But some questions like the cause that makes some part of protons leak away from a beam bunch to a bunch gap are yet left open. (4), A new scheme of two step H{sup 0} injection is proposed to remove defects of the conventional one of Los Alamos PSR. (author)

  13. Dynamic analysis of the reciprocating compressor package on the offshore platform (United States)

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


    Reciprocating compressor packages are key equipment for the offshore platforms which are used for the pressurization and transportation of natural gas. Dynamic analyses of high-speed and flexible supported offshore compressor packages are more complex than that of compressors on land. The dynamic analysis techniques of the offshore reciprocating compressor package were studied including numerical modelling, excitation forces calculation, support boundary determination of the compressor package and load transmission between the compressor package and the offshore platform. The finite element model of the compressor package with multiple types of elements such as the pipe, beam and shell elements were established. Excitation forces mainly including gas forces inside cylinders, crosshead forces, acoustic shaking forces and unbalanced inertia forces were calculated. In order to investigate the influence of the flexibility of the platform on dynamic characteristics of the compressor package and set reasonable boundaries for the support structure, three kinds of support boundaries were compared. The support points of columns and vertical beams on the layer of deck where the compressor package is installed were determined to be the most suitable ones. Super-element method was applied to implement the load transmission from the compressor package to the platform. The analysis techniques herein were successfully applied to the dynamic analysis of an offshore reciprocating compressor package in an engineering project.

  14. Machine characteristics, system arrangement, driver and operation effects on surge of dynamic compressor in oil and gas plants

    Energy Technology Data Exchange (ETDEWEB)

    Almasi, Amin


    Working in the surge area will result in an unstable compressor operation, exposing the dynamic compressor (centrifugal compressor or axial compressor) to destructive stress, high vibration and other damaging effects. The destructive power of the surge is enormous, ranging from changes in clearances, which result in a penalty in the compressor efficiency, to destruction of parts leading to bearing, rotor or seal replacements. The effects of compressor characteristics, driver type, compressor accessories, vent valve, check valve, trip delay and operation details on surge events and anti-surge system designs are studied. A case study is also discussed. (orig.)

  15. Comparison of energy-efficiency and size of portable oil-free screw and scroll compressors (United States)

    Dmitriev, Olly; MacDonald Arbon, Ian, Prof.


    This paper presents test data and evaluates if conical screw compressors can become a preferred alternative to scroll compressors in small oil-free duties from 0.04 to 15kW. The conical screw compressor is a new modification of the conventional screw compressor. A 2kW water-injected conical compressor demonstrated a 34% better energy efficiency than a scroll compressor of similar capacity. At 8 bar(g) load, the conical machine used 13% more energy and produced 42% more flow. Size of the conical screw package is 46% of the scroll package. The miniature conical screw package, at 40W rated power, achieved a pressure of 8 bar(g) in water-injected operation. It can be concluded that the conical screw compressor would be an attractive alternative in micro and small oil-free applications.

  16. Impact of the electric compressor for automotive air conditioning system on fuel consumption and performance analysis (United States)

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


    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.

  17. Oil flow at the scroll compressor discharge: visualization and CFD simulation (United States)

    Xu, Jiu; Hrnjak, Pega


    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.

  18. Technological advances of compressors in refrigerating machines. Evolutions technologiques des compresseurs de machines frigorifiques

    Energy Technology Data Exchange (ETDEWEB)

    Sartre, V.; Lallemand, M. (Centre National de la Recherche Scientifique, 69 - Villleurbanne (France)); Chiaffi, M. (Societe Bertin et Compagnie, 78 - Plaisir (France))


    The present study is related to the development of compressors for heat pumps and refrigerating machines. For a given application, various compressor technologies are possible. The choice is often dictated by the experience acquired on a compressor type, ensuring good reliability and a reasonable cost of the plant. In our study, we examine the limits of various compressor types: piston, screw, scroll, rotary vane, rolling piston and centrifugal. A comparison of the theoretical and practical limits of the compressors' operating ranges shows the necessity of better adaptation of the compressor type to each application. Finally, we suggest the main research focus for the development of future compressors. The new technologies should evolve towards a variable-speed operation, without lubricating oil or with refrigerant lubrication. Acoustic comfort is also an important criterion. (author)

  19. Recent developments of axial flow compressors under transonic flow conditions (United States)

    Srinivas, G.; Raghunandana, K.; Satish Shenoy, B.


    The objective of this paper is to give a holistic view of the most advanced technology and procedures that are practiced in the field of turbomachinery design. Compressor flow solver is the turbulence model used in the CFD to solve viscous problems. The popular techniques like Jameson’s rotated difference scheme was used to solve potential flow equation in transonic condition for two dimensional aero foils and later three dimensional wings. The gradient base method is also a popular method especially for compressor blade shape optimization. Various other types of optimization techniques available are Evolutionary algorithms (EAs) and Response surface methodology (RSM). It is observed that in order to improve compressor flow solver and to get agreeable results careful attention need to be paid towards viscous relations, grid resolution, turbulent modeling and artificial viscosity, in CFD. The advanced techniques like Jameson’s rotated difference had most substantial impact on wing design and aero foil. For compressor blade shape optimization, Evolutionary algorithm is quite simple than gradient based technique because it can solve the parameters simultaneously by searching from multiple points in the given design space. Response surface methodology (RSM) is a method basically used to design empirical models of the response that were observed and to study systematically the experimental data. This methodology analyses the correct relationship between expected responses (output) and design variables (input). RSM solves the function systematically in a series of mathematical and statistical processes. For turbomachinery blade optimization recently RSM has been implemented successfully. The well-designed high performance axial flow compressors finds its application in any air-breathing jet engines.

  20. Approach to novel design of CO2 based centrifugal compressor

    Directory of Open Access Journals (Sweden)

    Kura Tomasz


    Full Text Available Even though turbomachinery design issues have been investigated almost since the beginning of engineering, its optimization process is still important. With the development of refrigeration devices and ORC based distributed generation facilities, a need for efficient and low-energy compressors and turbines became even more demanding. Such machines working with typical fluid, like air, are well described, but there is a room regarding the fluids like CO2, vapour of organic fluids, etc. The main objective of present studies is to propose a numerical model of the centrifugal compressor, with CO2 as the working fluid. Such unit may be a part of refrigeration cycle. Commonly, the scroll or piston compressors are used in such cases, however some discussed disadvantages show that the novel designs should be looked for. Properly designed centrifugal compressors can have higher efficiency than the presently used. Three dimensional analyses of proposed geometries were conducted – using a model including heat, mass and momentum conservation laws as well as ideal gas law. Verification of the proposed mesh and results was performed in the basis of values obtained using theoretical and empirical equations. With about 700 000 control volumes in the validated model, error of the results was no higher than 5%, with only about 1% in regards to the thermal parameters. Two design proposals were analysed, with performance maps as the main comparison factor. Apart from performance characteristics, the pressure and velocity fields were presented, showing the process of flow structure optimization. The main goal was to reduce negative effects of pressure and velocity gradients on the performance. Proposed precursory design might be a good starting point for further development of compressors. The results of numerical analysis were promising and shows the possibility of proposed design usage in practical applications, however to obtain deep understanding of the

  1. Compressor Calorimeter Test of R-410A Alternative: R-32/134a Mixture Using a Scroll Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S [ORNL; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL


    As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares the performance of lower-GWP alternative refrigerant R-32 + R-134a mixture, to that of refrigerant R-410A (baseline) in a scroll compressor designed for air-conditioning and heat pump applications. These comparisons were carried out via compressor calorimeter tests performed on a compressor designed for refrigerant R-410A and having a nominal rated capacity of 21,300 Btu/hr. Tests were conducted over a suction dew point temperature range of 10 F to 55 F in 5 F increments and a discharge dew point temperature range of 70 F to 140 F in 10 F increments. All the tests were performed with 20 F superheat, 40 F superheat, and 65 F suction temperature. A liquid subcooling level of 15 F was maintained for all the test conditions. The tests showed that the discharge temperature of the alternative refrigerant was higher than that of R-410A at all test conditions. Also, the energy efficiency ratio (EER) and cooling capacity of compressor using the alternative refrigerant were slightly lower in comparison to that of R-410A.

  2. Numerical study of a high-speed miniature centrifugal compressor (United States)

    Li, Xiaoyi

    A miniature centrifugal compressor is a key component of reverse Brayton cycle cryogenic cooling system. The system is commonly used to generate a low cryogenic temperature environment for electronics to increase their efficiency, or generate, store and transport cryogenic liquids, such as liquid hydrogen and oxygen, where space limit is also an issue. Because of space limitation, the compressor is composed of a radial IGV, a radial impeller and an axial-direction diffuser (which reduces the radial size because of smaller diameter). As a result of reduction in size, rotating speed of the impeller is as high as 313,000 rpm, and Helium is used as the working fluid, in order to obtain the required static pressure ratio/rise. Two main characteristics of the compressor---miniature and high-speed, make it distinct from conventional compressors. Higher compressor efficiency is required to obtain a higher COP (coefficient of performance) system. Even though miniature centrifugal compressors start to draw researchers' attention in recent years, understanding of the performance and loss mechanism is still lacking. Since current experimental techniques are not advanced enough to capture details of flow at miniature scale, numerical methods dominate miniature turbomachinery study. This work numerically studied a high speed miniature centrifugal compressor with commercial CFD code. The overall performance of the compressor was predicted with consideration of interaction between blade rows by using sliding mesh model. The law of similarity of turbomachinery was validated for small scale machines. It was found that the specific ratio effect needs to be considered when similarity law is applied. But Reynolds number effect can be neglected. The loss mechanism of each component was analyzed. Loss due to turning bend was significant in each component. Tip leakage loss of small scale turbomachines has more impact on the impeller performance than that of large scale ones. Because the


    Energy Technology Data Exchange (ETDEWEB)

    Michael J. Crowley; Prem N. Bansal


    This report contains the final project summary and deliverables required by the award for the development of an In-line Electric Motor Driven Compressor (IEMDC). Extensive work was undertaken during the course of the project to develop the motor and the compressor section of the IEMDC unit. Multiple design iterations were performed to design an electric motor for operation in a natural gas environment and to successfully integrate the motor with a compressor. During the project execution, many challenges were successfully overcome in order to achieve the project goals and to maintain the system design integrity. Some of the challenges included limiting the magnitude of the compressor aerodynamic loading for appropriate sizing of the magnetic bearings, achieving a compact motor rotor size to meet the rotor dynamic requirements of API standards, devising a motor cooling scheme using high pressure natural gas, minimizing the impact of cooling on system efficiency, and balancing the system thrust loads for the magnetic thrust bearing. Design methods that were used on the project included validated state-of-the-art techniques such as finite element analysis and computational fluid dynamics along with the combined expertise of both Curtiss-Wright Electro-Mechanical Corporation and Dresser-Rand Company. One of the most significant areas of work undertaken on the project was the development of the unit configuration for the system. Determining the configuration of the unit was a significant step in achieving integration of the electric motor into a totally enclosed compression system. Product review of the IEMDC unit configuration was performed during the course of the development process; this led to an alternate design configuration. The alternate configuration is a modular design with the electric motor and compressor section each being primarily contained in its own pressure containing case. This new concept resolved the previous conflict between the aerodynamic flow

  4. 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 (United States)

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


    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

  5. Experimental study on neon refrigeration system using commercial helium compressor (United States)

    Ko, Junseok; Kim, Hyobong; Hong, Yong-Ju; Yeom, Hankil; Koh, Deuk-Yong; Park, Seong-Je


    In this study, we developed neon refrigeration system using commercial helium compressor which was originally designed for GM cryocooler. We performed this research as precedent study before developing neon refrigeration system for small-scale hydrogen liquefaction system. The developed system is based on precooled Linde-Hampson system with liquid nitrogen as precoolant. Design parameters of heat exchangers are determined from thermodynamic cycle analysis with operating pressure of 2 MPa and 0.4 MPa. Heat exchangers have concentric-tube heat exchanger configuration and orifice is used as Joule- Thomson expansion device. In experiments, pressure, temperature, mass flow rate and compressor input power are measured as charging pressure. With experimental results, the characteristics of heat exchanger, Joule-Thomson expansion and refrigeration effect are discussed. The developed neon refrigeration system shows the lowest temperature of 43.9 K.

  6. Variable speed hermetic reciprocating compressors for domestic refrigerators

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.


    This article describes the results of a both theoretical and experimental investigation of the performance of variable speed hermetic reciprocating compressors for domestic refrigerators. The investigation was performed as a part of a larger research project with the objective of reducing...... the energy consumption of domestic refrigerators by increasing the efficiency of the refrigeration system. The improvement of the system efficiency was to be obtained by introducing continuous operation and use variable speed compressors for controlling the capacity of the refrigeration system....... It was the aim of the project to double the efficiency of the refrigeration system and thereby reduce the energy consumption of the refrigerator by 50% compared to a standard refrigerator available on the market to day....

  7. Quasi-Optical 34-GHz Rf Pulse Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L


    Designs have been carried out on non-high-vacuum, low-power versions of three- and four-mirror quasi-optical passive and active Ka-band pulse compressors, and prototypes built and tested based on these designs. The active element is a quasi-optical grating employing gas discharge tubes in the gratings. Power gains of about 3:1 were observed experimentally for the passive designs, and about 7:1 with the active designs. High-power, high-vacuum versions of the three-and four-mirror quasi-optical pulse compressors were built and tested at low power. These now await installation and testing using multi-MW power from the 34-GHz magnicon.

  8. SKIP A Pulse Compressor for SuperKEKB

    CERN Document Server

    Sugimura, T; Kakihara, K; Kamitani, T; Ohsawa, S; Yokoyama, K


    An upgrade of KEKB injector linac is planned. A main purpose of this upgrade is to increase injection energy of positrons from 3.5 GeV to 8.0 GeV for the SuperKEKB project. By a limitation of land area, our choice is to double an acceleration field utilizing a C-band accelerator structures instead of present S-band structures. Last year we developed C-band components such as accelerator structure, dummy load, 3 dB hybrid coupler, RF window, sub booster, modulator system, and so on. These components were assembled at a test stand and processed. This accelerator unit was installed in the beam line of injector linac and has been under operation. This summer we will install an RF pulse compressor system to the C-band accelerator unit. This paper reports the status of development of the RF pulse compressor system.

  9. Small, high pressure ratio compressor: Aerodynamic and mechanical design (United States)

    Bryce, C. A.; Erwin, J. R.; Perrone, G. L.; Nelson, E. L.; Tu, R. K.; Bosco, A.


    The Small, High-Pressure-Ratio Compressor Program was directed toward the analysis, design, and fabrication of a centrifugal compressor providing a 6:1 pressure ratio and an airflow rate of 2.0 pounds per second. The program consists of preliminary design, detailed areodynamic design, mechanical design, and mechanical acceptance tests. The preliminary design evaluate radial- and backward-curved blades, tandem bladed impellers, impeller-and diffuser-passage boundary-layer control, and vane, pipe, and multiple-stage diffusers. Based on this evaluation, a configuration was selected for detailed aerodynamic and mechanical design. Mechanical acceptance test was performed to demonstrate that mechanical design objectives of the research package were met.

  10. A High Reliability Gas-driven Helium Cryogenic Centrifugal Compressor

    CERN Document Server

    Bonneton, M; Gistau-Baguer, Guy M; Turcat, F; Viennot, P


    A helium cryogenic compressor was developed and tested in real conditions in 1996. The achieved objective was to compress 0.018 kg/s Helium at 4 K @ 1000 Pa (10 mbar) up to 3000 Pa (30 mbar). This project was an opportunity to develop and test an interesting new concept in view of future needs. The main features of this new specific technology are described. Particular attention is paid to the gas bearing supported rotor and to the pneumatic driver. Trade off between existing technologies and the present work are presented with special stress on the bearing system and the driver. The advantages are discussed, essentially focused on life time and high reliability without maintenance as well as non pollution characteristic. Practical operational modes are also described together with the experimental performances of the compressor. The article concludes with a brief outlook of future work.

  11. Active surge control for variable speed axial compressors. (United States)

    Lin, Shu; Yang, Chunjie; Wu, Ping; Song, Zhihuan


    This paper discusses active surge control in variable speed axial compressors. A compression system equipped with a variable area throttle is investigated. Based on a given compressor model, a fuzzy logic controller is designed for surge control and a proportional speed controller is used for speed control. The fuzzy controller uses measurements of the change of pressure rise as well as the change of mass flow to determine the throttle opening. The presented approach does not require the knowledge of system equilibrium or the surge line. Numerical simulations show promising results. The proposed fuzzy logic controller performs better than a backstepping controller and is capable to suppress surge at different operating points. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  12. Noise Reduction Design of the Volute for a Centrifugal Compressor (United States)

    Song, Zhen; Wen, Huabing; Hong, Liangxing; Jin, Yudong


    In order to effectively control the aerodynamic noise of a compressor, this paper takes into consideration a marine exhaust turbocharger compressor as a research object. According to the different design concept of volute section, tongue and exit cone, six different volute models were established. The finite volume method is used to calculate the flow field, whiles the finite element method is used for the acoustic calculation. Comparison and analysis of different structure designs from three aspects: noise level, isentropic efficiency and Static pressure recovery coefficient. The results showed that under the concept of volute section model 1 yielded the best result, under the concept of tongue analysis model 3 yielded the best result and finally under exit cone analysis model 6 yielded the best results.

  13. Numerical Simulation and Performance Analysis of Twin Screw Air Compressors

    Directory of Open Access Journals (Sweden)

    W. S. Lee


    Full Text Available A theoretical model is proposed in this paper in order to study the performance of oil-less and oil-injected twin screw air compressors. Based on this model, a computer simulation program is developed and the effects of different design parameters including rotor profile, geometric clearance, oil-injected angle, oil temperature, oil flow rate, built-in volume ratio and other operation conditions on the performance of twin screw air compressors are investigated. The simulation program gives us output variables such as specific power, compression ratio, compression efficiency, volumetric efficiency, and discharge temperature. Some of the above results are then compared with experimentally measured data and good agreement is found between the simulation results and the measured data.

  14. Application of Risk-Based Inspection method for gas compressor station (United States)

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


    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.

  15. Dynamic Model of Centrifugal Compressor for Prediction of Surge Evolution and Performance Variations

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Mooncheong; Han, Jaeyoung; Yu, Sangseok [Chungnam National Univ., Daejeon (Korea, Republic of)


    When a control algorithm is developed to protect automotive compressor surges, the simulation model typically selects an empirically determined look-up table. However, it is difficult for a control oriented empirical model to show surge characteristics of the super charger. In this study, a dynamic supercharger model is developed to predict the performance of a centrifugal compressor under dynamic load follow-up. The model is developed using Simulink® environment, and is composed of a compressor, throttle body, valves, and chamber. Greitzer’s compressor model is used, and the geometric parameters are achieved by the actual supercharger. The simulation model is validated with experimental data. It is shown that compressor surge is effectively predicted by this dynamic compressor model under various operating conditions.

  16. Characterization and Performance Testing of Natural Gas Compressors for Residential and Commercial Applications (United States)

    Zhang, Xinye; Groll, Eckhard A.; Bethel, Dylan


    Relatively little information is available in the literature with respect to the performance of compressors used during the dynamic charging process of a tank. Therefore, work presented in this paper shows the measurement results of performance testing of a natural gas compressor and analyses the compressor characterization based on the experimental data. Initial tests were conducted using air and carbon dioxide given the thermodynamic similarities between these fluids and natural gas. Finally, a new test stand was specifically designed and built for compressor dynamic testing using pipeline natural gas (NG) and the compressor reliability has been evaluated inside an explosion-proof engine test cell. Reliability tests at standard operating conditions monitored the performance consistency of the compressors over the testing period and the testing consisted of a series of tank charges aimed at evaluating the maximum operating temperature as well as the mass flow rate in the system.

  17. Stage-by-Stage and Parallel Flow Path Compressor Modeling for a Variable Cycle Engine (United States)

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


    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.

  18. Comprehensive 3D-elastohydrodynamic simulation of hermetic compressor crank drive (United States)

    Posch, S.; Hopfgartner, J.; Berger, E.; Zuber, B.; Almbauer, R.; Schöllauf, P.


    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.

  19. Centrifugal compressor shape modification using a proposed inverse design method

    Energy Technology Data Exchange (ETDEWEB)

    Niliahmadabadi, Mahdi [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Poursadegh, Farzad [Sharif University of Technology, Tehran (Iran, Islamic Republic of)


    This paper is concerned with a quasi-3D design method for the radial and axial diffusers of a centrifugal compressor on the meridional plane. The method integrates a novel inverse design algorithm, called ball-spine algorithm (BSA), and a quasi-3D analysis code. The Euler equation is solved on the meridional plane for a numerical domain, of which unknown boundaries (hub and shroud) are iteratively modified under the BSA until a prescribed pressure distribution is reached. In BSA, unknown walls are composed of a set of virtual balls that move freely along specified directions called spines. The difference between target and current pressure distributions causes the flexible boundary to deform at each modification step. In validating the quasi-3D analysis code, a full 3D Navier-Stokes code is used to analyze the existing and designed compressors numerically. Comparison of the quasi-3D analysis results with full 3D analysis results shows viable agreement. The 3D numerical analysis of the current compressor shows a huge total pressure loss on the 90 .deg. bend between the radial and axial diffusers. Geometric modification of the meridional plane causes the efficiency to improve by about 10%.

  20. Efficiency of liquid-jet high-pressure booster compressors (United States)

    Mikheev, N. I.; Davletshin, I. A.; Mikheev, A. N.; Kratirov, D. V.; Fafurin, V. A.


    There are almost no experimental data on the head-capacity curves for liquid-jet compressors with the inlet gas pressure of liquid-jet apparatus more than 1 MPa. Meanwhile, this range is important for many engineering applications in which relatively low compressor ratio is required for the pumping of gas under high pressure. This is mostly the case when gas circulation is to be provided in a closed or almost closed circuit. A head-capacity curve of a liquid-jet apparatus has been estimated experimentally for the air pumping at up to 2.5 MPa by a water jet. To obtain this curve, a new original technique has been submitted and verified which is based on an inverse unsteady problem of gas pumping and allows derivation of the whole curve instead of one operating point, which is the case for conventional methods. The experiments have demonstrated that the relative head of the liquid-jet compressor grows with the apparatus inlet air pressure in the middle part of the curve.

  1. A new Wankel-type compressor and vacuum pump (United States)

    Garside, D. W.


    When the Wankel principles were first published in the early 1950s most of the initial work was aimed at developing a compressor . At that time many of the characteristics appeared to promise a superior machine than hitherto known. However, all the early designs resulted in a high value for the minimum clearance volume (CV) and this problem was never overcome. Knowledge now gained from the development and manufacture of the Wankel engine has enabled the evolution of a new compressor concept where the rotor flank, radially very close-fitting over its central area, provides gas sealing with the housing bore. The rotor has an increased radial clearance towards the apices which makes the machine practical to manufacture. The ‘nesting’ of the rotor flank with the housing bore at the end of the exhaust stroke results in an extremely small CV. This machine promises to possess an exceptional combination of all the attributes which are important in achieving high energy efficiency in positive-displacement compressors and vacuum pumps: - near-zero CV - low mechanical friction losses - low internal gas leakage (assisted via oil flooding) - high volumetric efficiency. In addition it is compact, lightweight, vibration-free, consists of few components, and can be built in any chamber size. The Paper discusses the features and characteristics of the design.

  2. Avoiding compressor surge during emergency shutdown hybridturbine systems

    Energy Technology Data Exchange (ETDEWEB)

    Pezzini, Paolo [University of Genova, Italy; Tucker, David [U.S. DOE; Traverso, Alberto [University of Genova, Italy


    A new emergency shutdown procedure for a direct-fired fuel cell turbine hybrid power system was evaluated using a hardware-based simulation of an integrated gasifier/fuel cell/turbine hybrid cycle (IGFC), implemented through the Hybrid Performance (Hyper) project at the National Energy Technology Laboratory, U.S. Department of Energy (NETL). The Hyper facility is designed to explore dynamic operation of hybrid systems and quantitatively characterize such transient behavior. It is possible to model, test, and evaluate the effects of different parameters on the design and operation of a gasifier/fuel cell/gas turbine hybrid system and provide a means of quantifying risk mitigation strategies. An open-loop system analysis regarding the dynamic effect of bleed air, cold air bypass, and load bank is presented in order to evaluate the combination of these three main actuators during emergency shutdown. In the previous Hybrid control system architecture, catastrophic compressor failures were observed when the fuel and load bank were cut off during emergency shutdown strategy. Improvements were achieved using a nonlinear fuel valve ramp down when the load bank was not operating. Experiments in load bank operation show compressor surge and stall after emergency shutdown activation. The difficulties in finding an optimal compressor and cathode mass flow for mitigation of surge and stall using these actuators are illustrated.

  3. Thirty years of screw compressors for helium; Dreissig Jahre Schraubenkompressoren fuer Helium

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, H. [Kaeser Kompressoren GmbH, Coburg (Germany). Technisches Buero/Auftragskonstruktion


    KAESER helium compressors, as well as their other industrial compressors, will be further developed with the intention to improve the availability and reliability of helium liquefaction systems. Further improvement of compressor and control system efficiency will ensure a low and sustainable operating cost. Fast supply of replacement parts with several years of warranty is ensured by a world-wide distribution system and is also worked on continuously. (orig.)

  4. Plasma nitriding of steels

    CERN Document Server

    Aghajani, Hossein


    This book focuses on the effect of plasma nitriding on the properties of steels. Parameters of different grades of steels are considered, such as structural and constructional steels, stainless steels and tools steels. The reader will find within the text an introduction to nitriding treatment, the basis of plasma and its roll in nitriding. The authors also address the advantages and disadvantages of plasma nitriding in comparison with other nitriding methods. .

  5. Operating Characteristics of Expander/Compressor Combination for Carbon Dioxide Refrigeration Cycle (United States)

    Fukuta, Mitsuhiro; Yanagisawa, Tadashi; Nakaya, Seiji

    An expander can improve the performance of CO2 refrigeration cycles by recovering a throttling loss. One way to utilize the recovered work is to drive an additional compressor by the expander, and it is effective to use an intercooler between a first-stage compressor and a second-stage compressor. An expander/compressor combination, in which the second-stage compressor is driven by the expander autonomously, is developed and the operating characteristics of the achine are discussed. It is operated at a balance point of mass flow rate and shaft torque between the compressor and the expander, and the balance point can be estimated using performance data of the compressor and expander. Although the expander/compressor combination improves the cycle performance, a heat rejection pressure is not maintained at an optimum pressure under off-design operating conditions. A control that keeps the heat rejection pressure optimum by a pre-expansion or a bypass is effective to obtain good performance of the CO2 refrigeration cycle with the expander/compressor combination.

  6. Study on the dynamic characteristics, refrigerant and lubricating oil in the high-pressure hermetic compressor. (United States)

    Okada, Tetsuji

    The dynamics characteristics and refrigerant and lubricating oil in the high-pressure hermeti compressor has been studied. The compressor is 1 HP for the air conditioner of home use. The experiment and the analytic simulation have been researched. As a result, the theoretic compressor model was proposed. This model has three processes inside of compressor. They are the suction process, the compression process, and the discharge process. In each process, mass equations and energy equations are considered. Also, the inlet refrigerant conditions (2-phase refrigerant) were simulated and the dynamic characteristics of refrigerant and refrigerant and lubricating oil at starting was obtaied.

  7. The design and development of an oil-free compressor for Spacelab Refrigerator/Freezer (United States)

    Hye, A.


    Design features and test results of an oil-free compressor developed for Spacelab Mission-4 Refrigerator/Freezer are detailed. The compressor has four identical pistons activated by a common eccentric shaft, operated by a brushless dc motor at 1300 rpm. The stroke of each piston is 0.28 cm, with the piston ends connected to the shaft by means of sealed needle bearings, eliminating the ned for oil. The mass flow rates produced by the compressor are by over 100 percent higher compared to the original Amfridge unit. Test results show that the compressor can meet the Spacelab refrigerator/freezer requirements.

  8. Dynamic modelling and PID loop control of an oil-injected screw compressor package (United States)

    Poli, G. W.; Milligan, W. J.; McKenna, P.


    A significant amount of time is spent tuning the PID (Proportional, Integral and Derivative) control loops of a screw compressor package due to the unique characteristics of the system. Common mistakes incurred during the tuning of a PID control loop include improper PID algorithm selection and unsuitable tuning parameters of the system resulting in erratic and inefficient operation. This paper details the design and development of software that aims to dynamically model the operation of a single stage oil injected screw compressor package deployed in upstream oil and gas applications. The developed software will be used to assess and accurately tune PID control loops present on the screw compressor package employed in controlling the oil pressures, temperatures and gas pressures, in a bid to improve control of the operation of the screw compressor package. Other applications of the modelling software will include its use as an evaluation tool that can estimate compressor package performance during start up, shutdown and emergency shutdown processes. The paper first details the study into the fundamental operational characteristics of each of the components present on the API 619 screw compressor package and then discusses the creation of a dynamic screw compressor model within the MATLAB/Simulink software suite. The paper concludes by verifying and assessing the accuracy of the created compressor model using data collected from physical screw compressor packages.

  9. Design of low energy bunch compressors with space charge effects

    Directory of Open Access Journals (Sweden)

    A. He


    Full Text Available In this paper, we explore a method to manipulate low energy electron bunches in a space charge dominated regime, and we use this method to design low energy linac bunch compressors to compress electron bunches in a space charge dominated regime. In the method, we use the space charge effects instead of avoiding them; i.e., we use the space charge forces to generate the required energy chirp instead of the ordinary method which uses the rf accelerating system to generate the chirp. We redefine the concepts of the dispersion function and beta functions in a space charge dominated regime to guide the optimization. Using this method, we study the low energy (5–22 MeV linac bunch compressor design to produce short (∼150  fs and small size (∼30  μm bunches for the electron beam slicing project. The low energy linac bunch compressors work in a space charge dominated regime, and the bunches at the downstream of the gun have a negative energy chirp due to the space charge effects. To provide compression for the negative energy chirped bunch, we design a positive R_{56} dispersive section using a four-dipole chicane with several quadrupole magnets. We have designed low energy linac bunch compressors with different photocathode rf guns. For example, one linac bunch compressor with the BNL photocathode electron rf gun has achieved a low energy bunch with the 166 fs rms bunch length, 28 and 31  μm rms beam size in the vertical and horizontal directions, respectively, at 5 MeV with 50 pC charge. Another example with LBNL’s very-high frequency gun has achieved a low energy bunch with the 128 fs rms bunch length, 42 and 25  μm rms beam size in the vertical and horizontal directions, respectively, at 22 MeV with 200 pC charge.

  10. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Energy Technology Data Exchange (ETDEWEB)

    Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)


    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  11. Improved flow performance of a centrifugal compressor based on pit formation on the notum of the whirligig beetle (Gyrinidae Latreille)


    Limei Tian; Ziyuan Li; Jin, E.; Qingpeng Ke; Shiyun Dong; Yunhai Ma


    Many studies have shown that bionic forms reduce drag through the control fluid medium. In this study, the evenly aligned pits of the whirligig beetle (Gyrinidae Latreille) notum were selected as the bionic form to be studied. They were used in centrifugal compressor impellers, called bionic centrifugal compressors, and the flow characteristics were simulated and compared to the prototype compressor. The simulation results show that compared to the prototype compressor, the pressure drag of b...

  12. Design of compressors for FEL pulses using deformable gratings (United States)

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


    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.

  13. Metal alloys for the new generation of compressors at hydrogen stations: Parametric study of corrosion behavior

    DEFF Research Database (Denmark)

    Arjomand Kermani, Nasrin; Petrushina, Irina; Nikiforov, Aleksey Valerievich


    Compressors are one of the most costly components at hydrogen stations, which leads to the high price of hydrogen production. The substitution of a solid piston with ionic liquid is a promising option that may solve some of the challenges related to conventional reciprocating compressors and, con...

  14. Comparative study of the noise generated by the moto-compressor ...

    African Journals Online (AJOL)

    The fundamental aim of this study is to compare between the noise generated by the moto-compressor and the noise generated by the turbo-compressor operating 24H/24H on the continuous function mode; these two machines make part of the equipment of the GP1Z, a factory of hydrocarbon treatment. To attain the ...

  15. A Stability Enhancement Method for Centrifugal Compressors using Active Control Casing Treatment System (United States)

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


    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.

  16. Effective combination of on-site measurements and simulations for a reciprocating compressor system

    NARCIS (Netherlands)

    Eijk, A.; Egas, G.


    The capacity of two parallel operating BORSIG reciprocating compressors, installed at the OMV refinery in Vienna, had to be increased. TNO TPD was ordered to investigate the dynamic effects on compressors and pipe work due to the increased flow to avoid vibration and fatigue problems afterwards. For

  17. Development of an Improvised Manual Airbrush Compressor for Students Artist in Nigeria (United States)

    Kwasu, Isaac Ali


    The study was set to develop and pilot a manual airbrush compressor for artists use in art and design. In the design of the manual airbrush, three established technological systems were adopted which includes, compressor, pressure tank and bicycle operating system. The idea was skillfully translated into a working drawing and developed into a…

  18. Influence of heat transfer between turbine and compressor on the performance of small turbochargers (United States)

    Rautenberg, M.; Malobabic, M.; Mobarak, A.

    When operating a turbocharger with an engine the turbine transfers a considerable amount of heat to its environment and to the compressor. Therefore the flow processes in the turbine as well as in the compressor are strongly diabatic. The definition and the experimental determination of turbine and compressor efficiency require a clear distinction between adiabatic and diabatic efficiencies since the heat flux between turbine and compressor must be taken into account. The influence of the heat flux between turbine and compressor on the compression process was studied at two turbochargers for passenger cars of different design. The essential difference of the two turbochargers is the arrangement of turbine and compressor, because the type of bearing is different for each charger. While one turbocharger has sliding bearings, the other charger exhibits roller bearings. The experiments were performed with hot and cold operation of the chargers. The results of the measurements show that the heat flux transferred from the turbine to the compressor and thus the compressor exit temperature depends to a large extent on the mechanical design of the turbocharger.

  19. Development of High Efficiency Swing Compressor for R32 Refrigerant


    Yamamoto, Yuuichi; Kanayama, Takehiro; Yuasa, Kenichi; Matsuura, Hideki


    In the age of global warming, energy saving features and overall reduction of environmental impact are critical components that must be addressed when developing new HVAC units. We chose the R32 refrigerant, with its lower LCCP as a more sustainable choice than the R410A. However, R32 has its drawbacks. Due to its smaller molecular weight, internal leakage loss is higher for the R32. Moreover, high discharge gas temperature decrease the reliability of the compressor, and make a large overheat...

  20. Limits to compression with cascaded quadratic soliton compressors

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw


    We study cascaded quadratic soliton compressors and address the physical mechanisms that limit the compression. A nonlocal model is derived, and the nonlocal response is shown to have an additional oscillatory component in the nonstationary regime when the group-velocity mismatch (GVM) is strong....... This inhibits efficient compression. Raman-like perturbations from the cascaded nonlinearity, competing cubic nonlinearities, higher-order dispersion, and soliton energy may also limit compression, and through realistic numerical simulations we point out when each factor becomes important. We find...

  1. Miniature high speed compressor having embedded permanent magnet motor (United States)

    Zhou, Lei (Inventor); Zheng, Liping (Inventor); Chow, Louis (Inventor); Kapat, Jayanta S. (Inventor); Wu, Thomas X. (Inventor); Kota, Krishna M. (Inventor); Li, Xiaoyi (Inventor); Acharya, Dipjyoti (Inventor)


    A high speed centrifugal compressor for compressing fluids includes a permanent magnet synchronous motor (PMSM) having a hollow shaft, the being supported on its ends by ball bearing supports. A permanent magnet core is embedded inside the shaft. A stator with a winding is located radially outward of the shaft. The PMSM includes a rotor including at least one impeller secured to the shaft or integrated with the shaft as a single piece. The rotor is a high rigidity rotor providing a bending mode speed of at least 100,000 RPM which advantageously permits implementation of relatively low-cost ball bearing supports.

  2. DESIGN a solar hybrid air conditioning compressor system

    Directory of Open Access Journals (Sweden)

    Khalaji Assadi M.


    Full Text Available To develop and integrate solar hybrid system into conventional air conditioning system which provides the same cooling load with considerably less electricity demand. Solar evacuated tube and DC compressor are used for compressing the refrigerant in an air conditioning system, thus effectively reducing the air conditioning electricity consumption by up to 45%. For the flow through type selected geometry of the designed evacuated U-tube collector, a three dimensional simulation and analysis of the thermal performance was done, using the solar ray-tracing model provided by the ANSYS-FLUENT software.

  3. Gas-turbine expander power generating systems for internal needs of compressor stations of gas-main pipelines (United States)

    Shimanov, A. A.; Biryuk, V. V.; Sheludko, L. P.; Shabanov, K. Yu.


    In the framework of this paper, there have been analyzed power station building methods to construct a power station for utilities for gas-main pipelines compressor stations. The application efficiency of turbo expanders in them to expand the power gas of compressor stations' gas compressor units has been shown. New schemes for gas-turbine expander power generating systems have been proposed.

  4. Improvement of Reliability of Compressors for Domestics Refrigerators using HFC134a (United States)

    Iizuka, Tadashi; Hata, Hiroaki

    In concerning with the trend for the phase out of CFC's,we have developed the technology for the rolling piston type rotary compressors for refrigerators using HFC134a. It is known that the reliability of compressors is less when using HFC134a for conventional compressors without any modifications than that when using CFC12. We have estimated some kinds of refrigerating oil,materials for motors,mechanical parts, and their compatibility for HFC134a. The life test using the compressors with the new oil,motor materials,and modified mechanical parts was carried out and it has been found that the reliability equivalent to that of CFC12 system can be maintained. However,this test only could estimate there liability of compressors under a certain limited condition. So we are now continuing extend examination to adapt the above-mentioned technology to various actual use.

  5. Modeling and analysis of an open-drive Z-compressor (United States)

    Ziviani, Davide; Groll, Eckhard A.


    A rotary Z-compressor prototype for compressed air applications has been developed and tested. The Z-compressor working process resembles the one of a two-stage rolling piston compressor where the stages are phased by half rotation. In contrary to the traditional rolling piston design, the vane in a Z-compressor is positioned parallel to the main shaft and not perpendicular. In order to understand the impact of leakage and frictional losses and improve the design of such machine, a mechanistic model has been developed to include governing equations within the working chambers (i.e., two suction chambers and two compression chambers), leakage flow models, detailed mechanical analysis, one-degree of freedom valve model, in-chamber heat transfer and an overall energy balance of the compressor shell. The model has been validated with preliminary experimental data and then exercised to identify the potential performance improvements over a range of clearances and working conditions.

  6. Evaluation and analysis on the coupling performance of a high-speed turboexpander compressor (United States)

    Chen, Shuangtao; Fan, Yufeng; Yang, Shanju; Chen, Xingya; Hou, Yu


    A high-speed turboexpander compressor (TEC) for small reverse Brayton air refrigerator is tested and analyzed in the present work. A TEC consists of an expander and a compressor, which are coupled together and interact with each other directly. Meanwhile, the expander and compressor have different effects on the refrigerator. The TEC overall efficiency, which contains effects of the expander's expansion, the compressor's pre-compression, and the pressure drop between them, was proved. It unifies influences of both compression and expansion processes on the COP of refrigerator and could be used to evaluate the TEC overall performance. Then, the coupling parameters were analyzed, which shows that for a TEC, the expander efficiency should be fully utilized first, followed by the compressor pressure ratio. Experiments were carried out to test the TEC coupling performances. The results indicated that, the TEC overall efficiency could reach 67.2%, and meanwhile 22.3% of the energy output was recycled.

  7. NASA Environmentally Responsible Aviation High Overall Pressure Ratio Compressor Research Pre-Test CFD (United States)

    Celestina, Mark L.; Fabian, John C.; Kulkarni, Sameer


    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.

  8. Establishing a Ballistic Test Methodology for Documenting the Containment Capability of Small Gas Turbine Engine Compressors (United States)

    Heady, Joel; Pereira, J. Michael; Ruggeri, Charles R.; Bobula, George A.


    A test methodology currently employed for large engines was extended to quantify the ballistic containment capability of a small turboshaft engine compressor case. The approach involved impacting the inside of a compressor case with a compressor blade. A gas gun propelled the blade into the case at energy levels representative of failed compressor blades. The test target was a full compressor case. The aft flange was rigidly attached to a test stand and the forward flange was attached to a main frame to provide accurate boundary conditions. A window machined in the case allowed the projectile to pass through and impact the case wall from the inside with the orientation, direction and speed that would occur in a blade-out event. High-peed, digital-video cameras provided accurate velocity and orientation data. Calibrated cameras and digital image correlation software generated full field displacement and strain information at the back side of the impact point.

  9. Updating temperature monitoring on reciprocating compressor connecting rods to improve reliability

    Directory of Open Access Journals (Sweden)

    Jim Townsend


    The compressors are used to move CO2 and boost the gas to the required field pressure, usually around 2,200 psig. Reciprocating compressors are flexible and able to handle wide capacity and condition swings, offer an efficient method of compressing almost any gas composition in a wide range of pressures and have numerous applications and wide power ratings. This makes them a vital component in various industrial facilities. Condition monitoring of critical rotating machinery is widely accepted by operators of centrifugal compressors. However, condition monitoring of reciprocating machinery such as compressors and internal combustion engines has not received the same degree of acceptance. This paper examines the reliability impact as a result of upgrading the temperature monitoring devices on the connecting rods of electric driven reciprocating compressors. A cost analysis is also presented to demonstrate that the upgrade in hardware and software will eventually yield a saving in the operating cost.

  10. Resistance Torque Based Variable Duty-Cycle Control Method for a Stage II Compressor (United States)

    Zhong, Meipeng; Zheng, Shuiying


    The resistance torque of a piston stage II compressor generates strenuous fluctuations in a rotational period, and this can lead to negative influences on the working performance of the compressor. To restrain the strenuous fluctuations in the piston stage II compressor, a variable duty-cycle control method based on the resistance torque is proposed. A dynamic model of a stage II compressor is set up, and the resistance torque and other characteristic parameters are acquired as the control targets. Then, a variable duty-cycle control method is applied to track the resistance torque, thereby improving the working performance of the compressor. Simulated results show that the compressor, driven by the proposed method, requires lower current, while the rotating speed and the output torque remain comparable to the traditional variable-frequency control methods. A variable duty-cycle control system is developed, and the experimental results prove that the proposed method can help reduce the specific power, input power, and working noise of the compressor to 0.97 kW·m-3·min-1, 0.09 kW and 3.10 dB, respectively, under the same conditions of discharge pressure of 2.00 MPa and a discharge volume of 0.095 m3/min. The proposed variable duty-cycle control method tracks the resistance torque dynamically, and improves the working performance of a Stage II Compressor. The proposed variable duty-cycle control method can be applied to other compressors, and can provide theoretical guidance for the compressor.

  11. Characteristics of multi-cell compressors; Charakteristiken von Vielzellenkompressoren

    Energy Technology Data Exchange (ETDEWEB)

    Zingerli, A.; Ehrbar, M.


    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of tests and measurements made at the University of Applied Science in Buchs, Switzerland, on a variable-speed, multi-cell, sliding-vane rotary compressor. The work forms part of a project that is to provide technical support for the evaluation of components for the so-called Swiss Retrofit Heat Pump Project. This heat pump must produce temperatures that are higher than those normally encountered for heat pumps in order to be able to replace old heating systems with high flow temperatures. The loading-test rig for the air-water heat pump built at the University is described and the performance of the compressor tested is discussed. Possibilities of using an economiser to boost performance at low ambient temperatures and to increase heating capacity are discussed, as are the effects on the heat pump's efficiency by varying heat-exchanger surface area.

  12. Detector for flow abnormalities in gaseous diffusion plant compressors (United States)

    Smith, S.F.; Castleberry, K.N.


    A detector detects a flow abnormality in a plant compressor which outputs a motor current signal. The detector includes a demodulator/lowpass filter demodulating and filtering the motor current signal producing a demodulated signal, and first, second, third and fourth bandpass filters connected to the demodulator/lowpass filter, and filtering the demodulated signal in accordance with first, second, third and fourth bandpass frequencies generating first, second, third and fourth filtered signals having first, second, third and fourth amplitudes. The detector also includes first, second, third and fourth amplitude detectors connected to the first, second, third and fourth bandpass filters respectively, and detecting the first, second, third and fourth amplitudes, and first and second adders connected to the first and fourth amplitude detectors and the second and third amplitude detectors respectively, and adding the first and fourth amplitudes and the second and third amplitudes respectively generating first and second added signals. Finally, the detector includes a comparator, connected to the first and second adders, and comparing the first and second added signals and detecting the abnormal condition in the plant compressor when the second added signal exceeds the first added signal by a predetermined value. 6 figs.

  13. Hardened plungers and piston rods for high-pressure compressors

    Energy Technology Data Exchange (ETDEWEB)


    This report was a summary of information on dimensions, materials, and operating conditions, as well as experience in the use of piston rods and plungers at Gelsenkirchen. The surface hardening of these parts and their resulting life and wear were of prime importance. Nitriding hardening was one of the best processes for the production of wearproof surfaces. Case hardening and autogeneous hardening had been found satisfactory. Heat hardening had been found to be a cheap process in many applications. Surfaces could be obtained by hard chrome plating which would have the same or higher wear resistance as nitriding and excel in the depth of hardness. However, the heat hardening alone produced hard layers which had sufficiently good properties for plungers and piston rods of the booster compressors, gas-circulation pumps, paste presses, compressors and possibly pressure-release machines. This plant possessed a hardening installation which offered the advantage of production of most of the required equipment right at the works. This was particularly important if a grinding machine was available. This arrangement had to be supplemented with a shaft furnace in which parts could be heated to remove stresses before and after machining. 5 tables.

  14. Flow and Performance Calculations of Axial Compressor near Stall Margin (United States)

    Hwang, Yoojun; Kang, Shin-Hyoung


    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.

  15. Experimental study of a mixed refrigerant Joule-Thomson cryocooler using a commercial air-conditioning scroll compressor (United States)

    Lee, Jisung; Lee, Kyungsoo; Jeong, Sangkwon


    Mixed refrigerant Joule-Thomson (MR J-T) cryocoolers have been used to create cryogenic temperatures and are simple, efficient, cheap, and durable. However, compressors for MR J-T cryocoolers still require optimization. As the MR J-T cryocooler uses a commercial scroll compressor developed for air-conditioning systems, compressor overheating due to the use of less optimized refrigerants may not be negligible, and could cause compressor malfunction due to burn-out of scroll tip seals. Therefore, in the present study, the authors propose procedures to optimize compressor operation to avoid the overheating issue when the MR J-T cryocooler is used with a commercial oil lubricated scroll compressor, and the present experimental results obtained for a MR J-T cryocooler. A single stage 1.49 kW (2 HP) scroll compressor designed for R22 utilizing a mixture of nitrogen and hydrocarbons was used in the present study. As was expected, compressor overheating and irreversible high temperatures at a compressor discharge port were found at the beginning of compressor operation, which is critical, and hence, the authors used a water injection cooling system for the compressor to alleviate temperature overshooting. In addition, a portion of refrigerant in the high-pressure stream was by-passed into the compressor suction port. This allowed an adequate compression ratio, prevented excessive temperature increases at the compressor discharge, and eventually enabled the MR J-T cryocooler to operate stably at 121 K. The study shows that commercial oil lubricated scroll compressors can be used for MR J-T cryocooling systems if care is exercised to avoid compressor overheating.

  16. Evaluation of static mixer flow enhancements for cryogenic viscous compressor prototype for ITER vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, Robert C.; Baylor, Larry R.; Meitner, Steven J.; Combs, Stephen K.; Ha, Tam; Morrow, Michael; Biewer, T. [Fusion and Materials for Nuclear System Division, Oak Ridge National Laboratory, Oak Ridge (United States); Rasmussen, David A.; Hechler, Michael P. [U.S. ITER Project Office, Oak Ridge National Laboratory, Oak Ridge (United States); Pearce, Robert J. H.; Dremel, Mattias [ITER Organization, 13115 St. Paul-lez-Durance (France); Boissin, J.-C. [Consultant, Grenoble (France)


    As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (up to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype.

  17. Evaluation of static mixer flow enhancements for cryogenic viscous compressor prototype for ITER vacuum system (United States)

    Duckworth, Robert C.; Baylor, Larry R.; Meitner, Steven J.; Combs, Stephen K.; Ha, Tam; Morrow, Michael; Biewer, T.; Rasmussen, David A.; Hechler, Michael P.; Pearce, Robert J. H.; Dremel, Mattias; Boissin, J.-C.


    As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (up to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype.

  18. Evaluation of Static Mixer Flow Enhancements for Cryogenic Viscous Compressor Prototype for ITER Vacuum System

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, Robert C [ORNL; Baylor, Larry R [ORNL; Meitner, Steven J [ORNL; Combs, Stephen Kirk [ORNL; Ha, Tam T [ORNL; Morrow, Michael [ORNL; Biewer, Theodore M [ORNL; Rasmussen, David A [ORNL; Hechler, Michael P [ORNL; Pearce, R.J.H. [ITER Organization, Cadarache, France; Dremel, M. [ITER Organization, Cadarache, France; Boissin, Jean Claude [Consultant


    As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (50 to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype

  19. The steel scrap age. (United States)

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M


    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  20. Air Conditioning Compressor Air Leak Detection by Image Processing Techniques for Industrial Applications

    Directory of Open Access Journals (Sweden)

    Pookongchai Kritsada


    Full Text Available This paper presents method to detect air leakage of an air conditioning compressor using image processing techniques. Quality of air conditioning compressor should not have air leakage. To test an air conditioning compressor leak, air is pumped into a compressor and then submerged into the water tank. If air bubble occurs at surface of the air conditioning compressor, that leakage compressor must be returned for maintenance. In this work a new method to detect leakage and search leakage point with high accuracy, fast, and precise processes was proposed. In a preprocessing procedure to detect the air bubbles, threshold and median filter techniques have been used. Connected component labeling technique is used to detect the air bubbles while blob analysis is searching technique to analyze group of the air bubbles in sequential images. The experiments are tested with proposed algorithm to determine the leakage point of an air conditioning compressor. The location of the leakage point was presented as coordinated point. The results demonstrated that leakage point during process could be accurately detected. The estimation point had error less than 5% compared to the real leakage point.

  1. Theoretical study on the efficacy of the cold compressor based cryogenic cycles (United States)

    Jadhav, Mohananand; Chakravarty, A.; Atrey, M. D.


    Cold compressor based cycles have emerged as practical necessity for sub 4.5K (sub atmospheric) large scale cryogenic systems as used in most modern high energy accelerators and tokamaks. The concept of cold compressor can be applied in a generalized way for even atmospheric (high pressure) cycles, if justified. A rise in temperature is exhibited at the exit of the cold compressor due to pressurization and the inefficiency involved in the process. This rise in temperature results in gain of sensible heat, and acts like a refrigeration load at that temperature. This loss can only be acceptable if other advantages of cold compressors are substantial. In the present work, it is tried to explore the possibility of using the emerged cold compressor technology for medium scale cryogenics. One of the objectives of the study is to develop a cold compressor based refrigeration cycle which can be implemented using the present infrastructure at Cryo-Technology Division, Bhabha Atomic Research Centre (BARC). In this endeavour, a cryogenic cycle analysis tool is developed and is validated against the process data available for 2K cryogenic plant at LHC. Three cold compressor based modifications are proposed to the presently installed modified Claude cycle based helium liquefier. These three cases are analysed and compared.

  2. An intracooling system for a novel two-stage sliding-vane air compressor (United States)

    Murgia, Stefano; Valenti, Gianluca; Costanzo, Ida; Colletta, Daniele; Contaldi, Giulio


    Lube-oil injection is used in positive-displacement compressors and, among them, in sliding-vane machines to guarantee the correct lubrication of the moving parts and as sealing to prevent air leakage. Furthermore, lube-oil injection allows to exploit lubricant also as thermal ballast with a great thermal capacity to minimize the temperature increase during the compression. This study presents the design of a two-stage sliding-vane rotary compressor in which the air cooling is operated by high-pressure cold oil injection into a connection duct between the two stages. The heat exchange between the atomized oil jet and the air results in a decrease of the air temperature before the second stage, improving the overall system efficiency. This cooling system is named here intracooling, as opposed to intercooling. The oil injection is realized via pressure-swirl nozzles, both within the compressors and inside the intracooling duct. The design of the two-stage sliding-vane compressor is accomplished by way of a lumped parameter model. The model predicts an input power reduction as large as 10% for intercooled and intracooled two-stage compressors, the latter being slightly better, with respect to a conventional single-stage compressor for compressed air applications. An experimental campaign is conducted on a first prototype that comprises the low-pressure compressor and the intracooling duct, indicating that a significant temperature reduction is achieved in the duct.

  3. Study and Design of a Linear Compressor of Voice-Coil Typ

    Directory of Open Access Journals (Sweden)

    VADAN, I.


    Full Text Available The paper presents the design and Finite Element (FEM analysis of a Linear compressor of voice coil type (LCVCT. This kind of linear compressor will be used in a refrigerator equipment. It is well-known that the replacing of the rotating compressor from a classical refrigerator by a linear compressor leads to an efficiency improving wit about 5% by avoiding the piston side friction, which is very important because of the huge number of refrigerators in operation world-wide. The linear compressor refrigerator is already commercially available in South Korea, equipped with an electromagnetic (fix coil and moving permanent magnet linear compressor. This paper presents a new type of linear compressor - a voice-coil type (fixed permanent magnet and moving coil. The operation principle is the same as for electrodynamic vibrator or electro-dynamic loud-speaker. The designing with rare earth permanent magnet is not a simple problem, because of the nonlinear characteristic of rare earth magnets. A magneto-static FEM analysis has been performed in order to validate the design methodology proposed in the paper.

  4. Numerical investigation of diffuser solidity effect on turbulent airflow and performance of the turbocharger compressor

    Directory of Open Access Journals (Sweden)

    Chehhat A.


    Full Text Available Low solidity diffuser in centrifugal compressors can achieve both high efficiency and wide operating ranges which is of great importance for turbocharger compressor. Low solidity is achieved by using a low chord to pitch ratio. In this work, a CFD simulation is carried out to examine the effect of solidity on airflow field of a turbocharger centrifugal compressor which consists of a simple-splitter impeller and a vaned diffuser. By changing the number of diffuser vanes while keeping the number of impeller blades constant, the solidity value of the diffuser is varied. The characteristics of the compressor are evaluated for 6, 8, 10 and 12 stator vanes which correspond to solidity of: 0.78, 1.04, 1.29 and 1.55, respectively. The spatial distribution of the pressure, velocity and turbulent kinetic energy show that the diffuser solidity has significant effect on flow field and compressor performance map. The compressor with a 6 vanes diffuser has higher efficiency and operates at a wider range of flow rate relative to that obtained with larger vans number. However a non-uniform flow at the compressor exit was observed with relatively high turbulent kinetic energy.

  5. Numerical investigation of refrigeration machine compressor operation considering single-phase electric motor dynamic characteristics (United States)

    Baidak, Y.; Smyk, V.


    Using as the base the differential equations system which was presented in relative units for generalized electric motor of hermetic refrigeration compressor, mathematical model of the software for dynamic performance calculation of refrigeration machine compressors drive low-power asynchronous motors was developed. Performed on its ground calculations of the basic model of two-phase electric motor drive of hermetic compressor and the proposed newly developed model of the motor with single-phase stator winding, which is an alternative to the industrial motor winding, have confirmed the benefits of the motor with innovative stator winding over the base engine. Given calculations of the dynamic characteristics of compressor drive motor have permitted to determine the value of electromagnetic torque swinging for coordinating compressor and motor mechanical characteristics, and for taking them into consideration in choosing compressor elements construction materials. Developed and used in the process of investigation of refrigeration compressor drive asynchronous single-phase motor mathematical and software can be considered as an element of computer-aided design system for design of the aggregate of refrigeration compression unit refrigerating machine.

  6. Performance improvement of air source heat pump by using gas-injected rotary compressor (United States)

    Wang, B. L.; Liu, X. R.; Ding, Y. C.; Shi, W. X.


    Rotary compressor is most widely used in small capacity refrigeration and heat pump systems. For the air source heat pump, the heating capacity and the COP will be obviously degraded when it is utilized in low temperature ambient. Gas injection is an effective method to enhance its performance under those situations, which has been well applied in air source heat pump with scroll compressor. However, the development of the gas injection technology in rotary compressor is relatively slow due to limited performance improvement. In this research, the essential reason constraining the improvement of the gas injection on the rotary compressor and its heat pump system is identified. Two new injection structures for rotary compressors has been put forward to overcome the drawback of traditional injection structures. Based on a verified numerical model, the thermodynamic performance of air source heat pumps with the new gas-injected rotary compressor are investigated. The results indicate that, compared to the air source heat pump with the traditional gas injected rotary compressor, the new injection structures both can enhance heating capacity and COP of the air source heat pump obviously.

  7. Variable speed rotary compressor and adjustable speed drive efficiencies measured in the laboratory (United States)

    Miller, W. A.

    Two state-of-the-art variable-speed rotary compressors, of nominal one ton cooling capacity, were instrumented and tested in the laboratory. Both compressors were identical except for their respective variable-speed drive systems (i.e., motor and inverter). One compressor had an inverter driven induction motor (IDIM) drive, and the other had a permanent magnet electronically commutated motor drive (PM-ECM). The laboratory study evaluated the compressor's efficiency under representative variable-speed conditions. Testing was conducted as a function of compressor drive frequency and of refrigerant condensing and evaporating conditions. Saturated refrigerant conditions, inlet superheat, and subcooling were controlled using a secondary refrigerant calorimeter. Spectrum analysis was conducted on the current input to one phase of the three-phase drive systems to measure motor speed and characterize harmonic content of the inverters. An optimal volt per Hz ratio was determined at 120-, 90-, 60-, and 30-Hz drive frequencies and at different load conditions for the rotary with induction motor as driven by a PWM inverter and also by a motor generator set (ideal induction motor drive). Variation of voltage input to the compressor had the largest effect at the lowest drive frequency (30Hz). A 5 percent variation about the optimal voltage at 30 Hz frequency caused a roughly 5 percent drop in compressor isentropic efficiency. Calorimeter data were used to develop modulating compressor and drive system performance maps. Performances of the two compressors were compared and the rotary with PM-ECM drive showed better efficiency trends at 30-Hz drive frequency. Above the 30-Hz drive frequency no clear advantage was observed for the PM-ECM vs the IDIM, possibly due to oversizing of the PM-ECM inverter.

  8. Model analysis and nonlinear control of air compressors (United States)

    Sari, Gholam-Reza

    For decades, gas turbines have been important, widespread, and reliable devices in the field of power generation, petrochemical industry, and aeronautics. They employ centrifugal and axial compressors which suffer from aerodynamic instabilities, namely, surge and rotating stall. These performance limiting instabilities can cause component stress, lifespan reduction, noise, and vibration. Furthermore, in variable speed axial compressors (VSACs), speed variations affect the system stability and can lead to surge and rotating stall. This limits the rate of speed variations and results in important performance penalties. The present work firstly addresses the bifurcation analysis of VSACs' model to investigate the impact of speed dynamics on the stability of efficient operating points. Here, the rate of speed variations (acceleration rate) is defined as a new parameter of the model and a detailed numerical bifurcation analysis is provided. The results of time-domain simulations not only validate the results of bifurcation analysis, but also broaden our knowledge about the transient response of the model, which is a matter of importance as well. The analysis reveals that speed variations can lead to a fully developed rotating stall as well as the previously reported temporary stall developments. The results show that the developed instabilities depend to a great extent on the acceleration rate. The impact of other key issues such as throttle gain, viscosity factor, initial speed, final speed, and the contribution of stall modes are also explored. From the control point of view, despite reported achievements, robust control design for compression systems remains a challenging problem. In this work, at first, two nonlinear approaches are proposed to tackle the stability problem of constant-speed axial compressors (CSACs). The first approach is a robust passivity-based control and the second one is a second order sliding mode control. The approaches tackle the challenging

  9. Advanced industrial gas turbine technology readiness demonstration program. Phase II. Final report: compressor rig fabrication assembly and test

    Energy Technology Data Exchange (ETDEWEB)

    Schweitzer, J. K.; Smith, J. D.


    The results of a component technology demonstration program to fabricate, assemble and test an advanced axial/centrifugal compressor are presented. This work was conducted to demonstrate the utilization of advanced aircraft gas turbine cooling and high pressure compressor technology to improve the performance and reliability of future industrial gas turbines. Specific objectives of the compressor component testing were to demonstrate 18:1 pressure ratio on a single spool at 90% polytropic efficiency with 80% fewer airfoils as compared to current industrial gas turbine compressors. The compressor design configuration utilizes low aspect ratio/highly-loaded axial compressor blading combined with a centrifugal backend stage to achieve the 18:1 design pressure ratio in only 7 stages and 281 axial compressor airfoils. Initial testing of the compressor test rig was conducted with a vaneless centrifugal stage diffuser to allow documentation of the axial compressor performance. Peak design speed axial compressor performance demonstrated was 91.8% polytropic efficiency at 6.5:1 pressure ratio. Subsequent documentation of the combined axial/centrifugal performance with a centrifugal stage pipe diffuser resulted in the demonstration of 91.5% polytropic efficiency and 14% stall margin at the 18:1 overall compressor design pressure ratio. The demonstrated performance not only exceeded the contract performance goals, but also represents the highest known demonstrated compressor performance in this pressure ratio and flow class. The performance demonstrated is particularly significant in that it was accomplished at airfoil loading levels approximately 15% higher than that of current production engine compressor designs. The test results provide conclusive verification of the advanced low aspect ratio axial compressor and centrifugal stage technologies utilized.

  10. Flow Characterization and Dynamic Analysis of a Radial Compressor with Passive Method of Surge Control (United States)

    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

  11. The analysis of typical profile clearances formation in meshing rotors of the screw compressor (United States)

    Mustafin, T. N.; Yakupov, R. R.; Khamidullin, M. S.; Khisameev, I. G.; Alyaev, V. A.; Paranina, O. Yu.


    The improvement of screw compressor energetic characteristics is related to their working process enhancement. In many ways, it depends on the gas leakage between working chambers through the gaps. One of the main gaps in the screw compressor is the rotor profile clearances. They also generally determine the smoothness of meshing, partially influencing vibration levels. The rotor profile clearances occur due to the reduction of the real rotor profile in relation to the theoretical profile. It is done to compensate negative factors such as a rotor thermal deformation, manufacturing errors, etc. Their deep analysis may help to improve the real rotor profiling method and increase the screw compressor energetic characteristics.

  12. 241-U-701 new compressor building and instrument air piping analyses

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F.H.


    Building anchorage analysis is performed to qualify the design of the new compressor building foundation given in the ECN ``241-U-701 New Compressor Building.`` Recommendations for some changes in the ECN are made accordingly. Calculations show that the 6-in.-slab is capable of supporting the pipe supports, and that the building foundation, air compressor and dryer anchorage, and electric rack are adequate structurally. Analysis also shows that the instrument air piping and pipe supports for the compressed air system meet the applicable code requirements and are acceptable. The building is for the U-Farm instrument air systems.

  13. Deformation Control of Scroll Compressor for CO2 Refrigerant (United States)

    Hiwata, Akira; Sawai, Kiyoshi; Morimoto, Takashi; Murakami, Hideki

    The compressors for CO2 refrigerant have a lot of difficulties to achieve high efficiency and reliability because of its very high operating pressure, which causes the deformation for scroll element. The deformations of the fixed scroll during operation fall into the following four categories: (1) pressure deformation due to pressure differences; (2) thermal deformation due to temperature difference; (3) deformation caused by welding for fixing the frame to the shell; and (4) bolt tightening deformation of the compression mechanism. In this study, in order to minimize the deformation during operation, deformations (1) and (2) are grasped by numerical calculations and deformations (3) and (4) are controlled to cancel the deformations (1) and (2) by adjusting the stiffness of fixed scroll. In addition, we measured the deformation under the operation by using the strain gauge in order to confirm that the proper stiffness of fixed scroll can minimize its total amount of deformation.

  14. Aero-Mechanical Coupling in a High-Speed Compressor (United States)


    ISO - LATED COMPRESSOR BLADE 4.1 Introduction The aeroelastic behavior of a single cantilevered blade in a uniform subsonic and...55 2000 4000 6000 8000 10000 12000 14000 16000 10 −12 10 −10 10 −8 10 −6 10 −4 10 −2 Frequency [Hz] A u to sp ec tr a l d en si ty o f th e b la d e v...el o ci ty [m 2 / s2 / H z] 0 1.27 2.54 3.81 5.08 6.35 7.62 8.89 ω⋆ = πfcU∞ (a) M ≈ 0.4 2000 4000 6000 8000 10000 12000 14000 16000 10 −12 10 −10

  15. Thermodynamic Analysis of the Diabatic Efficiency of Turbines and Compressors

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyoung Kuhn [Kookmin Univ., Seoul (Korea, Republic of)


    Thermodynamic analysis is conducted on the first-order approximation model for turbines and compressors. It is shown that the adiabatic efficiency could be greater than unity, depending on the entropic mean temperature, entropy generation, thermal reservoir temperature, and heat transfer. Therefore, adiabatic efficiency applied to a diabatic control volume results in an error overestimating its performance. To resolve this overestimation, it is suggested that a reversible diabatic process be referred to as an ideal process to evaluate diabatic efficiency . The diabatic efficiency suggested in this work is proven to always be less than unity and it is smaller than the exergy efficiency in most cases. The diabatic efficiency could be used as a more general definition of efficiency, which would include adiabatic efficiency.

  16. CFD simulation of a screw compressor with oil injection (United States)

    Ding, Hui; Jiang, Yu


    In this paper, a full 3D transient CFD model of a twin screw compressor with oil injection will be described in detail. The Volume Of Fraction (VOF) approach was used for two phase flow of gas and liquid. The numeric method and simulation conditions will be explained. Simulation results will be presented with discussion. The cooling and sealing effects of oil injection will be evaluated by comparing the simulation results for the cases with and without oil. The imbalance of mass and energy of the compression system in simulation results will be rigorously checked to prove the methodologies used in the simulation are fully conservative and consistent. The efficiency, speed, and robustness of the proposed approach will also be demonstrated through the test case.

  17. Operational Experience with a Cryogenic Axial-Centrifugal Compressor

    CERN Document Server

    Decker, L; Löhlein, K; Purtschert, W; Ziegler, B L; Lebrun, P; Tavian, L; Brunovsky, I; Tucek, L


    The Large Hadron Collider (LHC), presently under construction at CERN, requires large refrigeration capacity at 1.8 K. Compression of gaseous helium at cryogenic temperatures is therefore inevitable. Together with subcontractors, Linde Kryotechnik has developed a prototype machine. This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating at ambient temperature. Integrated in a test facility for superconducting magnets the machine has been commissioned without major problems and successfully gone through the acceptance test in autumn 1995. Subsequent steps were initiated to improve efficiency of this prototype. This paper describes operating experience gained so far and reports on measured performance prior to and after constructional modifications.

  18. Effect of Mechanism Error on Input Torque of Scroll Compressor

    Directory of Open Access Journals (Sweden)

    Man Zhao


    Full Text Available Based on the fundamental principle of plane four-bar mechanism, the force on the equivalent parallel four-bar mechanism was analyzed for scroll compressor with mini-crank antirotation, and the formula of input torque was proposed. The change of input torque caused by the mechanism size error was analyzed and verified with an example. The calculation results show that the mechanism size error will cause large fluctuation in input torque at the drive rod and connecting rod collinear and the fluctuation extreme value increases with rotational speed. Decreasing of the crankshaft eccentricity errors is helpful for reducing the effects of dimension error on input torque but will increase the friction loss of orbiting and fixed scroll wrap. The influence of size error should be considered in design in order to select suitable machining accuracy and reduce the adverse effect caused by size error.

  19. Optimization of RF Compressor in the SPARX Injector

    CERN Document Server

    Ronsivalle, Concetta; Ferrario, Massimo; Serafini, Luca; Spataro, Bruno


    The SPARX photoinjector consists in a rf gun injecting into three SLAC accelerating sections, the first one operating in the RF compressor configuration in order to achieve higher peak current. A systematic study based on PARMELA simulations has been done in order to optimize the parameters that influence the compression also in view of the application of this system as injector of the so called SPARXINO 3-5 nm FEL test facility. The results of computations show that peak currents at the injector exit up to kA level are achievable with a good control of the transverse and longitudinal emittance by means of a short SW section operating at 11424 MHz placed before the first accelerating section. Some working points in different compression regimes suitable for FEL experiments have been selected. The stability of these points and the sensitivity to various types of random errors are discussed.

  20. Vibration analysis of the synchronous motor of a propane compressor

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, D.; Rangel Junior, J. de S. [Petroleo Brasileiro S.A. - PETROBRAS, Rio de Janeiro, RJ (Brazil)], Emails:,; Moreira, R.G. [Petroleo Brasileiro S.A. - PETROBRAS, Cabiunas, RJ (Brazil)], E-mail:


    This paper aims at describing the Analysis of a synchronous electric motor which presented high vibration levels (shaft displacement and bearing housing vibration) during the commissioning process, as well as propose the best practices for the solution of vibration problems in similar situations. This motor belongs to the propane centrifugal compressor installed at a Gas Compression Station. The methodology used in this study conducted an investigation of the problems presented in the motor through the execution of many types of tests and the analysis of the results. The main evaluations were performed, such as the vibration analysis and the rotor dynamic analysis. The electric motor was shipped back to the manufacturer's shop, where the manufacturer made certain modifications to the motor structure so as to improve the structure stiffness, such as the improvement of the support and the increase of the thickness of the structural plates. In addition to that, the dynamic balancing of the rotating set was checked. Finally, the excitation at a critical speed close to the rated speed was found after Rotor Dynamics Analysis was performed again, because of the increase in bearing clearances. The bearing shells were replaced so as to increase the separation margin between these frequencies. In order to verify the final condition of the motor, the manufacturer repeated the standard tests - FAT (Factory Acceptance Tests) - according to internal procedure and international standards. As a result of this work, it was possible to conclude that there was a significant increase in the vibration levels due to unbalance conditions. It was also possible to conclude that there are close relationships between high vibration levels and unbalance conditions, as well as between high vibration levels and the stiffness of the system and its support. Certain points of attention related to the manufacturing process of the motor compressor are described at the end of this paper, based

  1. Tool steels. 5. edition

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, G.; Krauss, G.; Kennedy, R.


    The revision of this authoritative work contains a significant amount of new information from the past nearly two decades presented in an entirely new outline, making this a must have reference for engineers involved in tool-steel production, as well as in the selection and use of tool steels in metalworking and other materials manufacturing industries. The chapter on tool-steel manufacturing includes new production processes, such as electroslag refining, vacuum arc remelting, spray deposition processes (Osprey and centrifugal spray), and powder metal processing. The seven chapters covering tool-steel types in the 4th Edition have been expanded to 11 chapters covering nine main groups of tool steels as well as other types of ultrahigh strength steels sometimes used for tooling. Each chapter discusses in detail processing, composition, and applications specific to the particular group. In addition, two chapters have been added covering surface modification and trouble shooting production and performance problems.



    ULUKÖY, Arzum; CAN, Ahmet Çetin


    Boride layer has many advantages in comparison with traditional hardening methods. The boride layer has high hardening value and keeps it's hardeness at high temperatures, and it also shows favorible properties, such as the resistance to wear, oxidation and corrosion. The process can be applied at variety of materials, for instance steel, cast iron, cast steel, nickel and cobalt alloys and cermets. In this rewiew, boronizing process properties, boride layer on steel surfaces and specification...

  3. Design and prototyping of an ionic liquid piston compressor as a new generation of compressors for hydrogen refueling stations

    DEFF Research Database (Denmark)

    Arjomand Kermani, Nasrin

    to investigate the heat transfer phenomena inside the compression chamber; the system performance is evaluated, followed by the design process. The model is developed based on the mass and energy balance of the hydrogen, and liquid bounded by the wall of the compression chamber. Therefore, at each time step...... that depending on the heat transfer correlation, the hydrogen temperature reduces slightly between 0.2 and 0.4% compared to the adiabatic case, at 500 bar. The main reasons for the small temperature reduction are the large wall resistance and the small contact area at the interface. Moreover, the results......) or at the wall (200 times), leads to 22 % or 33% reduction of the hydrogen temperature, compared to the adiabatic case, at 500 bar, during 3.5 seconds compression, respectively. A suitable ionic liquid is selected as the most reliable replacement for the solid piston in the conventional reciprocating compressors...

  4. Mathematical Model of Variable Speed Refrigerant Compressor to Predict its Transient Behavior (United States)

    Yanagisawa, Tadashi; Shimizu, Takashi; Fukuta, Mitsuhiro; Ikeda, Kiyoharu

    To predict performance of a refrigerating cycle it is effective to use a computer simulation program which employs mathematical models of the cycle components. This paper describes a mathematical model of a rotary compressor which can expersses transient behavior of the compressor with variable operting speed. The compressor is divided into two control volumes and two control bodies, and the model is expressed by six governing differential equations on specific enthalpies of refrigerant in the control volumes, mass flow rates of refrigerant delivered from the volumes and temperatures of the bodies. Simulation results and experimental data are favorably compared for transient behaviors of the compressor under wide operating speed range. The model developed will be effectively integrated into cycle simulation of dynamic responses of inverter driven heat pumps.

  5. Title V Operating Permit: QEP Field Services Company - Coyote Wash Compressor Station (United States)

    Response to public comments and the Title V Operating Permit for the QEP Field Services Company, Coyote Wash Compressor Station, located on the Uintah and Ouray Indian Reservation in Uintah County, Utah.

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

    National Research Council Canada - National Science Library

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


    .... 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...

  7. Analysis of resonant frequency of moving magnet linear compressor of stirling cryocooler

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Ming; Chen, Xiaoping [Kunming Institute of Physics, Kunming 650223 (China)


    This paper analyzes resonant frequency of the moving magnet linear compressor of Stirling cryocooler. The CFD (Computational Fluid Dynamics) and FEM (Finite Element Method) are used for the analysis of resonant frequency with FLUENT 6.2 and ANSYS 11.0 and an experiment is designed for testing the resonant frequency of moving magnet linear compressor. Results from simulations and experiments showed that the resonant frequency of the moving magnet linear compressors is affected by the machine spring, the gas spring, the magnet spring, and the mass of moving assembly, while the resonant frequency of the moving coil linear compressors is only affected by the machine spring, the gas spring, and the mass of moving assembly. (author)

  8. Cooling system with compressor bleed and ambient air for gas turbine engine

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, Jan H.; Marra, John J.


    A cooling system for a turbine engine for directing cooling fluids from a compressor to a turbine blade cooling fluid supply and from an ambient air source to the turbine blade cooling fluid supply to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The cooling system may include a compressor bleed conduit extending from a compressor to the turbine blade cooling fluid supply that provides cooling fluid to at least one turbine blade. The compressor bleed conduit may include an upstream section and a downstream section whereby the upstream section exhausts compressed bleed air through an outlet into the downstream section through which ambient air passes. The outlet of the upstream section may be generally aligned with a flow of ambient air flowing in the downstream section. As such, the compressed air increases the flow of ambient air to the turbine blade cooling fluid supply.

  9. Discharge characteristics and dynamics of compressive plasma streams generated by a compact magnetoplasma compressor

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I. E.; Tereshin, V. I.; Chebotarev, V. V.; Solyakov, D. G.; Petrov, Yu. V.; Ladygina, M. S.; Marchenko, A. K.; Staltsov, V. V.; Yelisyeyev, D. V. [National Academy of Sciences of Ukraine, Institute of Plasma Physics, National Science Center ' Kharkiv Institute of Physics and Technology,' (Ukraine)


    Results from experimental studies of a compact magnetoplasma compressor designed for operation with heavy gases are presented. The integral characteristics of the discharge and the energy contents and other parameters of the generated xenon plasma streams are determined.

  10. Dynamics of formation of the compression plasma flow in a miniature magnetoplasma compressor (United States)

    Astashinskii, V. M.; Kuz'mitskii, A. M.; Mishchuk, A. A.


    Results are presented of studying integral parameters of the developed miniature gas-discharge magnetoplasma compressor and dynamics of formation of the compression plasma flow. Energy parameters of the discharge in this system are determined.

  11. Control of Surge in Centrifugal Compressors by Active Magnetic Bearings Theory and Implementation

    CERN Document Server

    Yoon, Se Young; Allaire, Paul E


    Control of Surge in Centrifugal Compressors by Active Magnetic Bearings sets out the fundamentals of integrating the active magnetic bearing (AMB) rotor suspension technology in compressor systems, and describes how this relatively new bearing technology can be employed in the active control of compressor surge. The authors provide a self-contained and comprehensive review of rotordynamics and the fundamentals of the AMB technology. The active stabilization of compressor surge employing AMBs in a machine is fully explored, from the modeling of the instability and the design of feedback controllers, to the implementation and experimental testing of the control algorithms in a specially-constructed, industrial-size centrifugal compression system. The results of these tests demonstrate the great potential of the new surge control method developed in this text. This book will be useful for engineers in industries that involve turbocompressors and magnetic bearings, as well as for researchers and graduate students...

  12. Development of Axial Compressor Heat-Extraction Capability for Thermal Management Applications Project (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc. (ATA) proposes a small business innovation research (SBIR) program for a novel compressor heat-extraction development program in response to...

  13. The applicability of existing renovation methods in technology of screw compressors repairing (United States)

    Kosenko, P. V.


    The article deals with the basic methods of machine parts recovery. Advantages and disadvantages of these methods had been widely spoken. The effect of these methods on the surface properties had been analysed. The main reasons of the wear of screw compressor parts are described in short. The authors paid attention to the evaluation of the applicability of existing renovation methods in technology of screw compressors repairing. In choosing the optimal method of renovation the surfaces of screw compressor parts are guided by the criteria of RAMS: reliability, availability, maintainability and safety. Also, it is specially noted about the evaluation of the effect of renovation methods on the screw surface layer by the following criteria: adhesion, ecological safety, cost, wear resistance, hardness, roughness, layer thickness, capacity, hogging, porousness, surface preparation, changes in the structure and physical properties of the base metal and ease of use. The most appropriate method for the renovation of parts of screw compressors had been proposed.

  14. Pack of Applied Programs for Complex Analysis of Thermo-Compressors

    Directory of Open Access Journals (Sweden)

    S. V. Zditovetskaya


    Full Text Available The paper proposes a pack of applied programs intended for conjugate calculation of cycle parameters with heat exchangers of thermo-compressor loop and a calculation of irreversible losses in the loop binding including non-stationary operational  mode is added to the pack.The paper contains investigations of thermo-compressor operation in the system of forced and exhaust ventilation for reduction of heat consumption by a heater in the cold season of the year

  15. Cascade Testing and CFD Applied to Gas Turbine Performance Improvement with Compressor Cleaning


    Gannan, Aiad


    With the growing interest in life cycle costs for heavy-duty gas turbines, equipment operators are investigating the trade off between performance improvements and associated maintenance costs. One of the key factors leading to performance degradation during plant operation is compressor fouling especially in harsh environments. These results from the adherence of dust or sand particles mixed with small oil droplets to compressor blade surfaces. The result is a reduction in com...

  16. Numerical simulation of radial compressor stages with seals and technological holes

    Directory of Open Access Journals (Sweden)

    Syka Tomáš


    Full Text Available Article describes numerical simulations of an air flow in radial compressor stages in the NUMECA CFD software. Four different radial compressor stages were solved in this article. During the tasks evaluating the stepped and straight impeller seals and technological holes influence on working characteristics and the flow field was observed. Also the CFD results comparison with results from the empiric design tool is described.

  17. Effect of ionization energy loss on plasma focus formation in an erosion-type magnetoplasma compressor (United States)

    Kamrukov, A. S.; Kozlov, N. P.; Chuvashev, S. N.


    The equations of radiation magnetogasdynamics, together with the real flow pattern and experimental data, are used to analyze the processes taking place in the plasma focus of a magnetoplasma compressor. It is shown that the energy lost in multiple ionization plays a big role in the energy balance of the plasma in the compression region of an erosion-type magnetoplasma compressor. The mechanisms for energy conversion demonstrated here serve as a guide to ways of controlling the parameters of the plasma focus.

  18. Dynamics of the interaction between plasma flows generated by a miniature magnetoplasma compressor and a target (United States)

    Astashynski, V. M.; Kuzmitski, A. M.; Mishchuk, A. A.


    Spectroscopic studies of compression plasma flows generated by a miniature magnetoplasma compressor and of the shock compressed plasma layer formed near a target surface exposed to these flows are reported. The peak electron temperature and density are found to be 3 eV and 1.2ṡ1016 cm-3, respectively, in the compressor flow and 4.5 eV and 6.7ṡ1016 cm-3 in the shock compressed layer.

  19. Finalize field testing of cold climate heat pump (CCHP) based on tandem vapor injection compressors

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    This report describes the system diagram and control algorithm of a prototype air-source cold climate heat pump (CCHP) using tandem vapor injection (VI) compressors. The prototype was installed in Fairbanks, Alaska and underwent field testing starting in 09/2016. The field testing results of the past six months, including compressor run time fractions, measured COPs and heating capacities, etc., are presented as a function of the ambient temperature. Two lessons learned are also reported.

  20. Research on Noise Reduction of Reed Valves of a Hermetic Refrigerator Compressor (United States)

    He, Zhilong; Chen, Qian; Li, Dantong; Wang, Ju; Xia, Pu; Wang, Tao


    The noise level of the refrigerator compressor has received more and more attention in recent years. As the key component of a compressor, reed valve is its main noise source. In this paper, a new noise reduction technology of coating on reed valve surface is proposed and verified by experiments. Firstly, the reed valves were coated, and their surface characteristics were checked. Then, the refrigerator compressor p-V diagram test was carried out to investigate the influence of doped diamond-like carbon (DLC) coating on power consumption. Finally, the noise test rig for the refrigerator compressor was set up. Based on the standard test method, noise spectrum was measured in a semi-anechoic room under standard working condition. Research results showed that the compressor noise was significantly reduced by 1.8dB (A) after coating. Moreover, the effect of aerodynamic noise reduction at suction side is better than that at discharge side. However, the influence of the film thickness on noise reduction value is little. The COP was reduced by 0.6% as compared to the compressor with uncoated reed valves.

  1. Thermal Performance Analysis of Small Hermetic Refrigeration and Air-Conditioning Compressors (United States)

    Kim, Man-Hoe; Bullard, Clark W.

    A simple physical model for small hermetic reciprocating, rotary and scroll compressors has been developed based on thermodynamic principles and large data sets from the compressor calorimeter and in situ tests. Pressure losses along the refrigerant path are neglected and a compression process is assumed isentropic. A mass flow rate model reflects clearance volumetric efficiency and simulates suction gas heating using an effectiveness method. Compressor work is calculated using the compressor efficiency represented by only two empirical parameters. A linear relationship between the discharge and shell temperatures is extracted from the large data sets and applied to the model for calculating the discharge temperature. Another experimental observation indicates that the specific volumes at the suction and discharge ports of the cylinder have linear relationships with the specific volumes at the compressor suction and discharge. Those relationships can be used for the compressor model and the possibility is reported. The models developed using physical principles and experimental observations can predict the mass flow rate and power consumption within ±3.0% accuracy.

  2. Optimization analysis of the motor cooling method in semi-closed single screw refrigeration compressor (United States)

    Wang, Z. L.; Shen, Y. F.; Wang, Z. B.; Wang, J.


    Semi-closed single screw refrigeration compressors (SSRC) are widely used in refrigeration and air conditioning systems owing to the advantages of simple structure, balanced forces on the rotor, high volumetric efficiency and so on. In semi-closed SSRCs, motor is often cooled by suction gas or injected refrigerant liquid. Motor cooling method will changes the suction gas temperature, this to a certain extent, is an important factor influencing the thermal dynamic performance of a compressor. Thus the effects of motor cooling method on the performance of the compressor must be studied. In this paper mathematical models of motor cooling process by using these two methods were established. Influences of motor cooling parameters such as suction gas temperature, suction gas quantity, temperature of the injected refrigerant liquid and quantity of the injected refrigerant liquid on the thermal dynamic performance of the compressor were analyzed. The performances of the compressor using these two kinds of motor cooling methods were compared. The motor cooling capacity of the injected refrigerant liquid is proved to be better than the suction gas. All analysis results obtained can be useful for optimum design of the motor cooling process to improve the efficiency and the energy efficiency of the compressor.

  3. Development of High Speed Inverter Rotary Compressor for the Air-conditioning System (United States)

    Kang, Seoung-Min; Yang, Eun-soo; Shin, Jin-Ung; Park, Joon-Hong; Lee, Se-Dong; Ha, Jong-Hun; Son, Young-Boo; Lee, Byeong-Chul


    In order to meet the various operating loads of an air-conditioning system, an inverter compressor with a wide operational range is necessary. One of the ways to achieve a wide operation range is to drive a small capacity compressor at high speed. Moreover, it is possible to maximize the efficiency in part-load operation condition close to actual operating conditions and to reduce the cost by compact design of a small capacity compressor. In addition, the shortage of maximum capacity, due to the small rated capacity, is covered through high speed operation. However, in general, if the compressor operates at high speed, problems occurs such as reduced efficiency due to friction, increased noise, increased amount of oil discharge and decreased durability of the main components. In order to solve these problems the following have been investigated: optimized dimension parameters of the compression chamber, enhanced shaft design and the structure for the reduction of oil discharge and noise at high speed operation. Finally the high speed inverter rotary compressor with high efficiency and more compact size has been developed as compared with the conventional rotary compressor.

  4. Effect of compressor design on auditory function and a psychoacoustic Turing test (United States)

    Edwards, Brent W.


    Hearing aids incorporate multiband compression to compensate for the loudness recruitment that results from sensorineural hearing impairment. No consensus exists in the hearing-aid industry on the best compressor design or on what the design criteria should be. Differences exist in compressor time constants, number of bands, filter shapes, and fitting formula. Such design differences can result in different aided auditory ability as measured by psychoacoustic tests. This research investigated the effect of different compressor designs on fundamental psychoacoustic ability. Multiband compressors with different time constants and different analysis/synthesis filterbanks designs were simulated. Aided performance by the hearing impaired was calculated under each configuration for several psychoacoustic measures, including forward masking, loudness summation, and simultaneous off-frequency masking. Differences in aided performance in these tasks were found: some compressor designs produced aided psychoacoustic ability that resembled normal performance, while other compressor designs did not significantly alter performance from unaided impairment. A psychoacoustic Turing test is proposed that incorporates these aided performance measures as part of a hearing-aid design, a validation strategy, and a comparative technique for evaluating different hearing-aid designs.

  5. Acoustical contribution calculation and analysis of compressor shell based on acoustic transfer vector method (United States)

    Chen, Xiaol; Guo, Bei; Tuo, Jinliang; Zhou, Ruixin; Lu, Yang


    Nowadays, people are paying more and more attention to the noise reduction of household refrigerator compressor. This paper established a sound field bounded by compressor shell and ISO3744 standard field points. The Acoustic Transfer Vector (ATV) in the sound field radiated by a refrigerator compressor shell were calculated which fits the test result preferably. Then the compressor shell surface is divided into several parts. Based on Acoustic Transfer Vector approach, the sound pressure contribution to the field points and the sound power contribution to the sound field of each part were calculated. To obtain the noise radiation in the sound field, the sound pressure cloud charts were analyzed, and the contribution curves in different frequency of each part were acquired. Meanwhile, the sound power contribution of each part in different frequency was analyzed, to ensure those parts where contributes larger sound power. Through the analysis of acoustic contribution, those parts where radiate larger noise on the compressor shell were determined. This paper provides a credible and effective approach on the structure optimal design of refrigerator compressor shell, which is meaningful in the noise and vibration reduction.

  6. Compressor and Turbine Models of Brayton Units for Space Nuclear Power Systems (United States)

    Gallo, Bruno M.; El-Genk, Mohamed S.; Tournier, Jean-Michel


    Closed Brayton Cycles with centrifugal flow, single-shaft turbo-machines are being considered, with gas cooled nuclear reactors, to provide 10's to 100's of electrical power to support future space exploration missions and Lunar and Mars outposts. Such power system analysis is typically based on the cycle thermodynamics, for given operating pressures and temperatures and assumed polytropic efficiencies of the compressor and turbine of the Brayton energy conversion units. Thus the analysis results not suitable for modeling operation transients such as startup and changes in the electric load. To simulate these transients, accurate models of the turbine and compressor in the Brayton rotating unit, which calculate the changes in the compressor and turbine efficiencies with system operation are needed. This paper presents flow models that account for the design and dimensions of the compressor impeller and diffuser, and the turbine stator and rotor blades. These models calculate the various enthalpy losses and the polytropic efficiencies along with the pressure ratios of the turbine and compressor. The predictions of these models compare well with reported performance data of actual hardware. In addition, the results of a parametric analysis to map the operations of the compressor and turbine, as functions of the rotating shaft speed and inlet Mach number of the gas working fluid, are presented and discussed. The analysis used a binary mixture of He-Xe with a molecular weight of 40 g/mole as the working fluid.

  7. Determining of actual profile clearances and screw compressor rotor positions depending on working conditions (United States)

    Mustafin, T. N.; Yakupov, R. R.; Khamidullin, M. S.; Khisameev, I. G.; Uybekova, L. H.; Paranina, O. Y.


    In general, screw compressor characteristics depend on their working chamber clearances. One of the main of clearances in the working chamber of screw compressors are the clearances between rotors’ profiles, which are produced due to a reducing of theoretical rotor profiles. This reducing is made to compensate thermal deformation, manufacturing errors and other negative factors, which occur during the screw compressor working cycles and may cause a rotors’ teeth interference. This also may result in a transmission error, which increases the rotor profile clearance on one side of rotor tooth and reduces on other. A screw compressor rotor gearing mathematical model which can predict the actual rotor position and value of the transmission error was developed. An analysis of compressor working conditions influence on the transmission error value is done. Results of the presented work are used for working process mathematical models for improving their accuracy. They also may be used as basis for development of reducing theoretical profiles methods with the aim to reducing of the rotor profiles’ clearances and improve screw compressor characteristics.

  8. Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8 and 19XB-1 Jet- Propulsion Engines. 4; Analysis of Compressor Performance (United States)

    Dietz, Robert O.; Kuenzig, John K.


    Investigations were conducted in the Cleveland altitude wind tunnel to determine the performance and operational characteristics of the 19B-2, 19B-8, and 19XS-1 turbojet engines. One objective was to determine the effect of altitude, flight Mach number, and tail-pipe-nozzle area on the performance characteristics of the six-stage and ten-stage axial-flow compressors of the 19B-8 and 19XB-1 engines, respectively, The data were obtained over a range of simulated altitudes and flight Mach numbers. At each simulated flight condition the engine was run over its full operable range of speeds. Performance characteristics of the 19B-8 and 19XB-1 compressors for the range of operation obtainable in the turboJet-engine installation are presented. Compressor characteristics are presented as functions of air flow corrected to sea-level conditions, compressor Mach number, and compressor load coefficient. For the range of compressor operation investigated, changes in Reynolds number had no measurable effect on the relations among compressor Mach number, corrected air flow, compressor load coefficient, compressor pressure ratio, and compressor efficiency. The operating lines for the 19B-8 compressor lay on the low-air-flow side of the region of maximum compressor efficiency; the 19B-8 compressor operated at higher average pressure coefficients per stage and produced a lower over-all pressure ratio than did the 19XB-1 compressor.

  9. Development of a turbine-compressor for 10 kW class neon turbo-Brayton refrigerator (United States)

    Hirai, Hirokazu; Hirokawa, Masaki; Yoshida, Shigeru; Sano, Tomonobu; Ozaki, Shinsuke


    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.

  10. Modified A{sup ++}-standard refrigerator with 30% reduction of energy consumption. Higher efficiency by compressor modification - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Siegrist, M.; Stahl, S.; Ganz, J.


    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at how a modified refrigerator can be given a higher efficiency by modifying the compressor. The modified refrigerator was fitted with a variable-speed compressor. This compressor could be run at much lower speeds so that it was in operation for up to 90% of the time. It was shown that less electricity was consumed the more the compressor ran. The report discusses the aims of the work and presents details on the standard refrigerator used for the tests. The compressor normally used and the variable-speed compressor used in the test are described. Systems for temperature control and data acquisition during the tests are described. The results obtained are examined and the influence of various factors is discussed.

  11. Improvement of Performance Range of Centrifugal Compressors Gas by Surge Line Modification Using Active Controller Based on Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Pezhman Mohammadi


    Full Text Available In this work, surge of prevention is a critical problem in oil and gas industries, particularly when return gas flow or gas flow reduces in transportation of gas pipelines. This paper is illustrated new results about surge control of centrifugal compressors .surge phenomenon is flow unsteady state in compressors which causes damages seriously in compressor construction. Furthermore, it also demonstrates in comparison with anti surge control ،active surge control expands stability range.Active surge control which based on fuzzy logic،is the main idea that used in this investigation. Using fuzzy controller causes an improvement in compressor's condition and increase performance range of the compressor, in addition to prevention of any instability in compressor. The simulation results is also satisfactory.

  12. Improving of the working process of axial compressors of gas turbine engines by using an optimization method (United States)

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


    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.

  13. An evaluation of 1D loss model collections for the off-design performance prediction of automotive turbocharger compressors (United States)

    Harley, P.; Spence, S.; Early, J.; Filsinger, D.; Dietrich, M.


    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.

  14. Study on the CO2 electric driven fixed swash plate type compressor for eco-friendly vehicles (United States)

    Nam, Donglim; Kim, Kitae; Lee, Jehie; Kwon, Yunki; Lee, Geonho


    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.

  15. Modern Steel Framed Schools. (United States)

    American Inst. of Steel Construction, Inc., New York, NY.

    In view of the cost of structural framing for school buildings, ten steel-framed schools are examined to review the economical advantages of steel for school construction. These schools do not resemble each other in size, shape, arrangement or unit cost; some are original in concept and architecture, and others are conservative. Cost and…

  16. Design and Development of a Novel Knudsen Compressor as a Part of a Joule-Thomson Cryocooler (United States)

    Muthuvijayan, Indra; Antelius, Mikael; Björneklett, Are; Nilsson, Peter; Thorslund, Robert


    This paper presents the design and development of a novel Knudsen compressor, with no moving parts, as a part of a Joule-Thomson cryocooler. The compressor works by using the Knudsen diffusion principle and includes a combination of graphene-based layers and Knudsen membranes in a particular fashion to pressurize the fluid. The Knudsen membrane for this application was selected by testing several commercially available materials. Prototypes of single stage and a multistage compressors are presented together with experimental evaluations. Insights on a Tube-in-Tube heat exchanger, as another part a the Joule-Thomson cryocooler, intended to integrate with the Knudsen compressor, are also presented.

  17. Analytical expressions for group-delay dispersion and third-order dispersion of a reflection grism-pair compressor. (United States)

    Su, Juan; Feng, Guoying


    We provide a detailed analytical expression of group-delay dispersion (GDD) and third-order dispersion (TOD) for a reflection grism-pair compressor without the first-order approximation of grating diffraction. The analytical expressions can be used to design a grism-pair compressor for compensating the dispersive material without ray tracing. Furthermore, the dispersion performance of the grism pair compressor, depending on compressor parameters, is comprehensively analyzed. Results are shown that we can adjust several parameters to obtain a certain GDD and TOD, such as the incidence angle of the beam, refractive index of the prism, grating constant, and the separation of the grism pair.

  18. Compressor Calorimeter Test of R-404A Alternatives ARM-31a, D2Y-65, L-40, and R32 + R-134a Mixture using a Scroll Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S [ORNL; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL


    As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares the performance of four lower-GWP alternative refrigerants, ARM-31a, D2Y-65, L-40, and R-32 + R-134a mixture, to that of refrigerant R-404A (baseline) in a scroll compressor designed for medium temperature refrigeration applications. These comparisons were carried out via compressor calorimeter tests performed on a compressor designed for refrigerant R-404A and having a nominal rated capacity of 23,500 Btu/hr. Tests were conducted over a suction dew point temperature range of -10 F to 35 F in 5 F increments and a discharge dew point temperature range of 70 F to 140 F in 10 F increments. All the tests were performed with 20 F superheat, 40 F superheat, and 65 F suction temperature. A liquid subcooling level of 10 F to 15 F was maintained for all the test conditions. However, the cooling capacities reported in this study are normalized for 0 F subcooling. The tests showed that the compressor energy efficiency ratio (EER) and cooling capacity with all four alternative refrigerants tested are higher at higher saturation suction and saturation discharge temperature and lower at lower saturation suction and saturation discharge temperature, compared to that of R-404A. Discharge temperatures of all the alternative refrigerants were higher than that of R-404A at all test conditions.

  19. Interferometric study on the compression region of a magnetoplasma compressor

    Energy Technology Data Exchange (ETDEWEB)

    Astashinskij, V.M.; Kostyukevich, E.A. (AN Belorusskoj SSR, Minsk. Inst. Fiziki)

    High-rate interferometric filming of a compression area of a magnetoplasma compressor of gaseous type has been performed at 1 torr initial pressure of working gas (air) by means of two mirror autocollimation interferometer with visualization of interference field mated with a high-rate photodetector (HRP) operating in the frame-by-frame regime with time resolution not worse than 1 Frequency of interference picture filming amounted to 375000 frame/second. Space distribution of electron concentrations for different discharge stages have been obtained. Maximum value of electron concentration is achieved at the plasma flow axis and constitutes 2x10/sup 18/ cm/sup -3/. Velocity of plasma boundary motion to the discharge axis and electron concentration gradients in the compression area have been determined. The presented values of electron concentration are in good agreement with results obtained with the spectroscopic method which points to truth of the results and the achieved accuracy of measurements permits to qualitatively compare the theory and experiment.

  20. Optimization of plasma flow parameters of the magnetoplasma compressor (United States)

    Dojcinovic, I. P.; Kuraica, M. M.; Obradovc, B. M.; Cvetanovic, N.; Puric, J.


    Optimization of the working conditions of the magnetoplasma compressor (MPC) has been performed through analysing discharge and compression plasma flow parameters in hydrogen, nitrogen and argon at different pressures. Energy conversion rate, volt-ampere curve exponent and plasma flow velocities have been studied to optimize the efficiency of energy transfer from the supply source to the plasma. It has been found that the most effective energy transfer from the supply to the plasma is in hydrogen as a working gas at 1000 Pa pressure. It was found that the accelerating regime exists for hydrogen up to 3000 Pa pressures, in nitrogen up to 2000 Pa and in argon up to 1000 Pa pressure. At higher pressures MPC in all the gases works in the decelerating regime. At pressures lower than 200 Pa, high cathode erosion is observed. MPC plasma flow parameter optimization is very important because this plasma accelerating system may be of special interest for solid surface modification and other technology applications.

  1. An alternative method for centrifugal compressor loading factor modelling (United States)

    Galerkin, Y.; Drozdov, A.; Rekstin, A.; Soldatova, K.


    The loading factor at design point is calculated by one or other empirical formula in classical design methods. Performance modelling as a whole is out of consideration. Test data of compressor stages demonstrates that loading factor versus flow coefficient at the impeller exit has a linear character independent of compressibility. Known Universal Modelling Method exploits this fact. Two points define the function - loading factor at design point and at zero flow rate. The proper formulae include empirical coefficients. A good modelling result is possible if the choice of coefficients is based on experience and close analogs. Earlier Y. Galerkin and K. Soldatova had proposed to define loading factor performance by the angle of its inclination to the ordinate axis and by the loading factor at zero flow rate. Simple and definite equations with four geometry parameters were proposed for loading factor performance calculated for inviscid flow. The authors of this publication have studied the test performance of thirteen stages of different types. The equations are proposed with universal empirical coefficients. The calculation error lies in the range of plus to minus 1,5%. The alternative model of a loading factor performance modelling is included in new versions of the Universal Modelling Method.

  2. A Lossless Fuzzy Binary AND/OR Compressor

    CERN Document Server

    Alipour, Philip B


    In this report, a new fuzzy 2bit-AND parallel-to-OR, or simply, a fuzzy binary AND/OR (FBAR) text data compression model as an algorithm is suggested for bettering spatial locality limits on nodes during database transactions. The current model incorporates a four-layer application technique: string-to-AND/OR pairwise binary bit + fuzzy quantum with noise conversions. This technique promotes a lossless data compression ratio of 2:1 up to values approximately = 3:1, generating a spatially-efficient compressed data file compared to nowadays data compressors. Data decompression/specific data reconstruction initiates an AND/OR pattern match technique in respect of fuzzy quantum indicators in the binary function field. The reconstruction of data occurs in the 4th layer using encryption methods. It is hypothesized that significant data compression ratio of 2n:1 for n>3:1 ratios, e.g., 32~64:1 are achievable via fuzzy qubit indexing over classical byte blocks for every bit position fragmented into a (1/2 upper +1/2 ...

  3. An Efficient Image Compressor for Charge Coupled Devices Camera

    Directory of Open Access Journals (Sweden)

    Jin Li


    Full Text Available Recently, the discrete wavelet transforms- (DWT- based compressor, such as JPEG2000 and CCSDS-IDC, is widely seen as the state of the art compression scheme for charge coupled devices (CCD camera. However, CCD images project on the DWT basis to produce a large number of large amplitude high-frequency coefficients because these images have a large number of complex texture and contour information, which are disadvantage for the later coding. In this paper, we proposed a low-complexity posttransform coupled with compressing sensing (PT-CS compression approach for remote sensing image. First, the DWT is applied to the remote sensing image. Then, a pair base posttransform is applied to the DWT coefficients. The pair base are DCT base and Hadamard base, which can be used on the high and low bit-rate, respectively. The best posttransform is selected by the lp-norm-based approach. The posttransform is considered as the sparse representation stage of CS. The posttransform coefficients are resampled by sensing measurement matrix. Experimental results on on-board CCD camera images show that the proposed approach significantly outperforms the CCSDS-IDC-based coder, and its performance is comparable to that of the JPEG2000 at low bit rate and it does not have the high excessive implementation complexity of JPEG2000.

  4. Interaction of temperature, humidity, driver preferences, and refrigerant type on air conditioning compressor usage. (United States)

    Levine, C; Younglove, T; Barth, M


    Recent studies have shown large increases in vehicle emissions when the air conditioner (AC) compressor is engaged. Factors that affect the compressor-on percentage can have a significant impact on vehicle emissions and can also lead to prediction errors in current emissions models if not accounted for properly. During 1996 and 1997, the University of California, Riverside, College of Engineering-Center for Environmental Research and Technology (CE-CERT) conducted a vehicle activity study for the California Air Resources Board (CARB) in the Sacramento, CA, region. The vehicles were randomly selected from all registered vehicles in the region. As part of this study, ten vehicles were instrumented to collect AC compressor on/off data on a second-by-second basis in the summer of 1997. Temperature and humidity data were obtained and averaged on an hourly basis. The ten drivers were asked to complete a short survey about AC operational preferences. This paper examines the effects of temperature, humidity, refrigerant type, and driver preferences on air conditioning compressor activity. Overall, AC was in use in 69.1% of the trips monitored. The compressor was on an average of 64% of the time during the trips. The personal preference settings had a significant effect on the AC compressor-on percentage but did not interact with temperature. The refrigerant types, however, exhibited a differential response across temperature, which may necessitate separate modeling of the R12 refrigerant-equipped vehicles from the R134A-equipped vehicles. It should be noted that some older vehicles do get retrofitted with new compressors that use R134A; however, none of the vehicles in this study had been retrofitted.


    Directory of Open Access Journals (Sweden)

    Arzum ULUKÖY


    Full Text Available Boride layer has many advantages in comparison with traditional hardening methods. The boride layer has high hardening value and keeps it's hardeness at high temperatures, and it also shows favorible properties, such as the resistance to wear, oxidation and corrosion. The process can be applied at variety of materials, for instance steel, cast iron, cast steel, nickel and cobalt alloys and cermets. In this rewiew, boronizing process properties, boride layer on steel surfaces and specifications and the factors that effect boride layer are examined

  6. Investigation of several important phenomena associated with the development of Knudsen compressors (United States)

    Young, Marcus Paul

    The perceived utility of compact, power efficient sensor systems, coupled with recent advances in micro-electro-mechanical systems (MEMS) fabrication capabilities, have encouraged the construction of micro/meso-scale sensors. Viable micro/meso-scale sensors have been demonstrated; however, in many cases micro/meso-scale vacuum pumps are required to complete the sensor systems. The Knudsen Compressor, a micro/meso-scale gas pump based on thermal transpiration, is one proposed technology for a micro/meso-scale gas roughing pump. There are additional potential far term applications for Knudsen Compressors applied as high-pressure gas sources. Knudsen Compressors have important advantages over other proposed micro/meso-scale gas roughing pumps: no moving parts, no oils or other supplementary fluids, quiet and steady operation, easily scalable, and a range of potential heating activation techniques. The primary focus of this thesis is technological and scientific advancements leading to the development of radiantly driven micro/meso-scale Knudsen Compressors as roughing pumps. Considerations for operating Knudsen Compressors near a practical minimum operating pressure, 10 mTorr, and maximum operating pressure, 10 atm, are discussed. Initial experiments and modeling with glass microsphere beds, one possible low-pressure transpiration membrane, are discussed. Several potentially significant flow phenomena are predicted to appear at high pressures. The Knudsen Compressor Performance Model is updated to include: short tube effects, a generalized aerogel transpiration model, radiant heating capabilities, and outward transpiration membrane cooling effects. The model was also altered to provide time dependent pumping simulations. The Knudsen Compressor Performance Model was used to complete optimization studies and to construct several proposed designs for different applications. Transpiration membrane temperature and steady-state pressure measurements were taken for a variety

  7. Reliability and Maintainability Analysis of a High Air Pressure Compressor Facility (United States)

    Safie, Fayssal M.; Ring, Robert W.; Cole, Stuart K.


    This paper discusses a Reliability, Availability, and Maintainability (RAM) independent assessment conducted to support the refurbishment of the Compressor Station at the NASA Langley Research Center (LaRC). The paper discusses the methodologies used by the assessment team to derive the repair by replacement (RR) strategies to improve the reliability and availability of the Compressor Station (Ref.1). This includes a RAPTOR simulation model that was used to generate the statistical data analysis needed to derive a 15-year investment plan to support the refurbishment of the facility. To summarize, study results clearly indicate that the air compressors are well past their design life. The major failures of Compressors indicate that significant latent failure causes are present. Given the occurrence of these high-cost failures following compressor overhauls, future major failures should be anticipated if compressors are not replaced. Given the results from the RR analysis, the study team recommended a compressor replacement strategy. Based on the data analysis, the RR strategy will lead to sustainable operations through significant improvements in reliability, availability, and the probability of meeting the air demand with acceptable investment cost that should translate, in the long run, into major cost savings. For example, the probability of meeting air demand improved from 79.7 percent for the Base Case to 97.3 percent. Expressed in terms of a reduction in the probability of failing to meet demand (1 in 5 days to 1 in 37 days), the improvement is about 700 percent. Similarly, compressor replacement improved the operational availability of the facility from 97.5 percent to 99.8 percent. Expressed in terms of a reduction in system unavailability (1 in 40 to 1 in 500), the improvement is better than 1000 percent (an order of magnitude improvement). It is worthy to note that the methodologies, tools, and techniques used in the LaRC study can be used to evaluate

  8. Measurement of Oil Film Thickness between Bush and Blade in Swing Type Refrigerant Compressor (United States)

    Tanaka, Shinji; Zuo, Siyang; Hikam, Achmad; Toyama, Toshiyuki

    A swing type refrigerant compressor was developed in order to overcome problems related to lubrication of a rotary compressor. However, the lubrication condition of the swing compressor has not been measured quantitatively yet. This paper describes an application of an eddy current displacement sensor to measure oil film thickness of a sliding part between a suction side bush and a blade in the swing compressor, and examined lubrication condition of the sliding part and a motion of the bush against the blade under some operating conditions. The results indicate that the sliding part between the suction side bush and the blade forms a wedge shape in shaft angle from 0° to 180° and forms a negative wedge shape in shaft angle from 180° to 360°. In addition, the results show that the oil film thickness on an upper edge side of the bush and a slope angle of the bush against the blade decrease with an increase of discharge pressure and increase with an increase of operating frequency of the compressor.

  9. Wear-Reducing Technologies for Rotary Compressors Using CO2 Refrigerant (United States)

    Nakao, Hideto; Maeyama, Hideaki; Hattori, Naotaka; Takayama, Tomoo

    We have developed a CO2 heat pump water heater compressor with a single-stage rotary mechanism for the first time in the world. Because the rotary compressor has a simple mechanism, it has become the mainstream for air conditioning compressors using R410A. The two-stage rotary and scroll compressors using CO2 have been put into practical use, however the single-stage rotary compressor had not been put to practical use, because the operating pressure of CO2 is more than three times as high as R410A refrigerants. We have applied a processing the DLC-Si (diamond-like-carbon-silicon) to the vane. It is the film of the DLC containing the silicon with a method of the plasma C.V.D. (chemical vapor deposit). The DLC-Si coated vane is hardly worn-out, only the surface roughness is smoothed. This paper describes the relationship between the silicon concentration in the DLC-Si film and their characteristics. Especially the adhesion strength is secured and the internal fracture is prevented by optimizing of the silicon concentration. In applying DLC-Si for practical use of the vane, we controlled the silicon concentration and secured high adhesion strength of the film. We were able to achieve an excellent level of wear durability.

  10. Gas dynamic design of the pipe line compressor with 90% efficiency. Model test approval (United States)

    Galerkin, Y.; Rekstin, A.; Soldatova, K.


    Gas dynamic design of the pipe line compressor 32 MW was made for PAO SMPO (Sumy, Ukraine). The technical specification requires compressor efficiency of 90%. The customer offered favorable scheme - single-stage design with console impeller and axial inlet. The authors used the standard optimization methodology of 2D impellers. The original methodology of internal scroll profiling was used to minimize efficiency losses. Radically improved 5th version of the Universal modeling method computer programs was used for precise calculation of expected performances. The customer fulfilled model tests in a 1:2 scale. Tests confirmed the calculated parameters at the design point (maximum efficiency of 90%) and in the whole range of flow rates. As far as the authors know none of compressors have achieved such efficiency. The principles and methods of gas-dynamic design are presented below. The data of the 32 MW compressor presented by the customer in their report at the 16th International Compressor conference (September 2014, Saint- Petersburg) and later transferred to the authors.


    Energy Technology Data Exchange (ETDEWEB)

    Robert J. McKee; Shane P. Siebenaler; Danny M. Deffenbaugh


    The objective of this Direct Surge Control project was to develop a new internal method to avoid surge of pipeline compressors. This method will safely expand the range and flexibility of compressor operations, while minimizing wasteful recycle flow at the lower end of the operating envelope. The approach is to sense the onset of surge with a probe that directly measures re-circulation at the impeller inlet. The signals from the probe are used by a controller to allow operation at low flow conditions without resorting to a predictive method requiring excessive margin to activate a recycle valve. The sensor developed and demonstrated during this project was a simple, rugged, and sensitive drag probe. Experiments conducted in a laboratory compressor clearly showed the effectiveness of the technique. Subsequent field demonstrations indicated that the increase in range without the need to recycle flow was on the order of 19% to 25%. The cost benefit of applying the direct surge control technology appears to be as much as $120 per hour per compressor for operation without the current level of recycle flow. This could amount to approximately $85 million per year for the U.S. Natural Gas Transmission industry, if direct surge control systems are applied to most pipeline centrifugal compressors.

  12. An experimental description of the flow in a centrifugal compressor from alternate stall to surge (United States)

    Moënne-Loccoz, V.; Trébinjac, I.; Benichou, E.; Goguey, S.; Paoletti, B.; Laucher, P.


    The present paper gives the experimental results obtained in a centrifugal compressor stage designed and built by SAFRAN Helicopter Engines. The compressor is composed of inlet guide vanes, a backswept splittered unshrouded impeller, a splittered vaned radial diffuser and axial outlet guide vanes. Previous numerical simulations revealed a particular S-shape pressure rise characteristic at partial rotation speed and predicted an alternate flow pattern in the vaned radial diffuser at low mass flow rate. This alternate flow pattern involves two adjacent vane passages. One passage exhibits very low momentum and a low pressure recovery, whereas the adjacent passage has very high momentum in the passage inlet and diffuses efficiently. Experimental measurements confirm the S-shape of the pressure rise characteristic even if the stability limit experimentally occurs at higher mass flow than numerically predicted. At low mass flow the alternate stall pattern is confirmed thanks to the data obtained by high-frequency pressure sensors. As the compressor is throttled the path to instability has been registered and a first scenario of the surge inception is given. The compressor first experiences a steady alternate stall in the diffuser. As the mass flow decreases, the alternate stall amplifies and triggers the mild surge in the vaned diffuser. An unsteady behavior results from the interaction of the alternate stall and the mild surge. Finally, when the pressure gradient becomes too strong, the alternate stall blows away and the compressor enters into deep surge.

  13. Dynamic counterbalancing the single-piston linear compressor of a Stirling cryogenic cooler (United States)

    Veprik, A.; Nachman, I.; Pundak, N.


    Low vibration Stirling cryocoolers often rely on dual-piston linear compressors, the known disadvantages of which, as compared to their single-piston rivals, are: low reliability, increased power consumption, price, bulk, sensitivity to external vibration and g-forces. However, because of the inherently low level of vibration export, as required in numerous vibration sensitive electronic and electro-optic applications, the dual-piston approach has become prevalent in today's industrial practice. The authors report on the novel approach to the passive control of a fundamental component of a vibration export from a single-piston compressor down to the levels typical for the actively controlled dual-piston rival. The technique relies on the newly proposed principle of dynamic counterbalancing, where an auxiliary movable mass is flexibly attached to a movable piston assembly and to the stationary compressor casing using auxiliary mechanical springs. The proper design of such a "spring-mass-spring" counterbalancer yields zero vibration export at minimum electrical power and current consumed by the motor. Based on the theoretical analysis, the design of the single-piston compressor of 1 W@77 K Ricor model K529N Stirling cryocooler was enhanced by adding such a counterbalancer. The obtained experimental results are in full agreement with the theoretical prediction. From experiment, the vibration export at driving frequency was reduced 57-fold at practically the same electrical current and power consumed by the compressor actuator as compared with the basic cooler.

  14. The Integration of an API619 Screw Compressor Package into the Industrial Internet of Things (United States)

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


    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.

  15. Pipeline investigation report : natural gas compressor station occurrence : Gazoduc TQM Inc., December 2000

    Energy Technology Data Exchange (ETDEWEB)



    On December 28, 2000, a release of natural gas resulted in an explosion that destroyed the electrical and services building at the Gazoduc TQM East Hereford compressor station, damaging the compressor building. Before the occurrence, the station had been shut down due to a manual initiation of the station's emergency shutdown system. A maintenance person was sent to the station to reinitiate the electric motor-driven compressor unit. The on-site maintenance person was seriously injured. This report presents factual information about the accident, the injuries and the damage to equipment. It also reviews particulars of the pipeline system, the compressor station design, construction and operations. An analysis of the natural gas stream found an unknown product in the compressor station. A history of previous explosions, ruptures, leaks and fires was presented along with quality control programs. Findings as to the causes and contributing factors of the accident were revealed along with findings as to risk and safety actions. tabs., figs.

  16. Glass Stronger than Steel (United States)

    Yarris, Lynn


    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  17. Metallurgy: Printing steels (United States)

    Todd, Iain


    Additive manufacturing has been used to fabricate a common stainless steel, which imparts a unique microstructure to this material, making it stronger and more ductile than that produced with conventional methods.

  18. Life after Steel (United States)

    Mangan, Katherine


    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  19. About the problems and perspectives of making precision compressor blades

    Directory of Open Access Journals (Sweden)

    V. E. Galiev


    Full Text Available The problems of manufacturing blades with high precision profile geometry are considered in the article. The variant of the technology under development rules out the use of mechanical processing methods for blades airfoil. The article consists of an introduction and six small sections.The introduction sets out the requirements for modern aircraft engines, makes a list of problems arisen in the process of their manufacturing, and marks the relevance of the work.The first section analyzes the existing technology of precision blades. There is an illustration reflecting the stages of the process. Their advantages and disadvantages are marked.The second section provides an illustration, which shows the system-based blades used in the manufacturing process and a model of the work piece using the technology being developed. An analysis of each basing scheme is presented.In the third section we list the existing control methods of geometrical parameters of blades airfoil and present the measurement error data of devices. The special attention is paid to the impossibility to control the accuracy of geometrical parameters of precision blades.The fourth section presents the advantages of the electrochemical machining method with a consistent vibration of tool-electrode and with feeding the pulses of technology current over the traditional method. The article presents data accuracy and surface roughness of the blades airfoil reached owing to precision electrochemical machining. It illustrates machines that implement the given method of processing and components manufactured on them.The fifth section describes the steps of the developed process with justification for the use of the proposed operations.Based on the analysis, the author argues that the application of the proposed process to manufacture the precision compressor blades ensures producing the items that meet the requirements of the drawing.

  20. Measuring the electron beam energy in a magnetic bunch compressor

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Kirsten


    Within this thesis, work was carried out in and around the first bunch compressor chicane of the FLASH (Free-electron LASer in Hamburg) linear accelerator in which two distinct systems were developed for the measurement of an electron beams' position with sub-5 {mu}m precision over a 10 cm range. One of these two systems utilized RF techniques to measure the difference between the arrival-times of two broadband electrical pulses generated by the passage of the electron beam adjacent to a pickup antenna. The other system measured the arrival-times of the pulses from the pickup with an optical technique dependent on the delivery of laser pulses which are synchronized to the RF reference of the machine. The relative advantages and disadvantages of these two techniques are explored and compared to other available approaches to measure the same beam property, including a time-of-flight measurement with two beam arrival-time monitors and a synchrotron light monitor with two photomultiplier tubes. The electron beam position measurement is required as part of a measurement of the electron beam energy and could be used in an intra-bunch-train beam-based feedback system that would stabilize the amplitude of the accelerating field. By stabilizing the accelerating field amplitude, the arrival-time of the electron beam can be made more stable. By stabilizing the electron beam arrival-time relative to a stable reference, diagnostic, seeding, and beam-manipulation lasers can be synchronized to the beam. (orig.)

  1. Progress of High Efficiency Centrifugal Compressor Simulations Using TURBO (United States)

    Kulkarni, Sameer; Beach, Timothy A.


    Three-dimensional, time-accurate, and phase-lagged computational fluid dynamics (CFD) simulations of the High Efficiency Centrifugal Compressor (HECC) stage were generated using the TURBO solver. Changes to the TURBO Parallel Version 4 source code were made in order to properly model the no-slip boundary condition along the spinning hub region for centrifugal impellers. A startup procedure was developed to generate a converged flow field in TURBO. This procedure initialized computations on a coarsened mesh generated by the Turbomachinery Gridding System (TGS) and relied on a method of systematically increasing wheel speed and backpressure. Baseline design-speed TURBO results generally overpredicted total pressure ratio, adiabatic efficiency, and the choking flow rate of the HECC stage as compared with the design-intent CFD results of Code Leo. Including diffuser fillet geometry in the TURBO computation resulted in a 0.6 percent reduction in the choking flow rate and led to a better match with design-intent CFD. Diffuser fillets reduced annulus cross-sectional area but also reduced corner separation, and thus blockage, in the diffuser passage. It was found that the TURBO computations are somewhat insensitive to inlet total pressure changing from the TURBO default inlet pressure of 14.7 pounds per square inch (101.35 kilopascals) down to 11.0 pounds per square inch (75.83 kilopascals), the inlet pressure of the component test. Off-design tip clearance was modeled in TURBO in two computations: one in which the blade tip geometry was trimmed by 12 mils (0.3048 millimeters), and another in which the hub flow path was moved to reflect a 12-mil axial shift in the impeller hub, creating a step at the hub. The one-dimensional results of these two computations indicate non-negligible differences between the two modeling approaches.

  2. An approach to fault diagnosis of reciprocating compressor valves using Teager-Kaiser energy operator and deep belief networks

    NARCIS (Netherlands)

    Tran, V.T.; Thobiani, Faisal Al; Ball, Andrew David


    This paper presents an approach to implement vibration, pressure, and current signals for fault diagnosis of the valves in reciprocating compressors. Due to the complexity of structure and motion of such compressor, the acquired vibration signal normally involves transient impacts and noise. This

  3. Influences of flow loss and inlet distortions from radial inlets on the performances of centrifugal compressor stages

    Energy Technology Data Exchange (ETDEWEB)

    Han, Feng Hui; Mao, Yi Jun [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an (China); Tan, Ji Jian [Dept. of Research and Development, Shenyang Blower Works Group Co., Ltd., Shenyang (China)


    Radial inlets are typical upstream components of multistage centrifugal compressors. Unlike axial inlets, radial inlets generate additional flow loss and introduce flow distortions at impeller inlets. Such distortions negatively affect the aerodynamic performance of compressor stages. In this study, industrial centrifugal compressor stages with different radial inlets are investigated via numerical simulations. Two reference models were built, simulated, and compared with each original compressor stage to analyze the respective and coupling influences of flow loss and inlet distortions caused by radial inlets on the performances of the compressor stage and downstream components. Flow loss and inlet distortions are validated as the main factors through which radial inlets negatively affect compressor performance. Results indicate that flow loss inside radial inlets decreases the performance of the whole compressor stage but exerts minimal effect on downstream components. By contrast, inlet distortions induced by radial inlets negatively influence the performance of the whole compressor stage and exert significant effects on downstream components. Therefore, when optimizing radial inlets, the reduction of inlet distortions might be more effective than the reduction of flow loss. This research provides references and suggestions for the design and improvement of radial inlets.

  4. Study on scroll compressor behavior in case of liquid refrigerant injectio (United States)

    Hirano, Takahisa; Hagimoto, Kiyoshi; Matsuda, Susumu

    Scroll compressors have excellent fundamental features such as high efficiency, high reliability, low vibration and low noise, so scroll compressors have been recently used to heat pump and automotive air conditioners. Furthermore, the development to low temperature applications such as a refrigeration unit has been taken. In the low temperature applications, as the suction gas pressure is very low the compression ratio is very high, and as a result the discharge gas goes to very high temperature. In order to lower discharge gas temperature, refrigerant liquid has been injected into compression pockets. Further, in case of both low temperature usage and heat pump, in order to cool down the motor refrigerant liquid bypass operating system has been adopted. We have theoretically and experimentally studied the scroll compressor behavior in case of liquid refrigerant is existed in the compession pockets. In this paper, we describe these analytical and experimental results.

  5. Variable gas spring for matching power output from FPSE to load of refrigerant compressor (United States)

    Chen, G.; Beale, W.T.


    The power output of a free piston Stirling engine is matched to a gas compressor which it drives and its stroke amplitude is made relatively constant as a function of power by connecting a gas spring to the drive linkage from the engine to the compressor. The gas spring is connected to the compressor through a passageway in which a valve is interposed. The valve is linked to the drive linkage so it is opened when the stroke amplitude exceeds a selected limit. This allows compressed gas to enter the spring, increase its spring constant, thus opposing stroke increase and reducing the phase lead of the displacer ahead of the piston to reduce power output and match it to a reduced load power demand. 6 figs.

  6. Rotor Design for an Efficient Single-Phase Induction Motor for Refrigerator Compressors

    Directory of Open Access Journals (Sweden)

    Hyun-Jin Ahn


    Full Text Available This article describes a rotor making technology for the production of high-efficiency single-phase induction motors (SPIMs to be used in refrigerator compressors. Rotors can have different aluminum fill factors according to the fabrication method. In order to examine the association between the fill factor and the efficiency of the rotor, we analyzed the distribution of magnetic flux density using the finite element method (FEM. Next, we made prototype rotors by conventional casting methods and by the proposed casting method and compared their fill factors. In addition, SPIMs were made using the rotors, and their efficiencies were measured using a dynamometer. Moreover, the SPIMs were put to use in a compressor, for testing, and for each SPIM the refrigerating capacity of the compressor was measured with a calorimeter. Based on the results of the FEM analysis of the magnetic flux density and the experiments, the reliability and validity of the proposed method were proven.

  7. 3 GHz Barrel Open Cavity (BOC) RF pulse compressor for CTF3

    CERN Document Server

    Brown, Peter


    A prototype 3 GHz RF pulse compressor, based on a single 'Barrel shaped Open Cavity' (BOC), was designed, manufactured and successfully high power tested into a RF load. It is now planned to install five such devices in the CTF3 drive beam linac currently being built at CERN. A specific feature of the BOC is the so-called "whispering gallery" mode which has a high internal Q-factor. Contrary to other cavity-based pulse compressors, such as SLED or LIPS, with this mode one can operate in a resonant rotating wave regime. Consequently, when used as an RF pulse compressor a single BOC is sufficient, whereas the LIPS and SLED schemes require two cavities and a 3-dB hybrid. A short description of the BOC and the results of high power operation specific to the CTF3 drive beam linac are presented.

  8. Energy-optimal speed control of fans and compressor in a refrigeration system

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Rasmussen, Bjarne D.


    Use of variable speed compressors and variable speed fans for both the evaporator and the condenser makes the refrigeration system more flexible, adds to the degree of freedom of the control system and therefore makes it possible to (on-line) optimise the various speeds involved. Say, for example...... that the cooling capacity must be increased due to increased cooling load. This can be done by increasing the compressor speed and/or the evaporator fan speed and also to some extent by increasing the condenser fan speed. The general control problem is to obtain the desired temperature of the cooled air, while...... choosing the combination of compressor speed, evaporator fan and condenser fan speeds which minimises the total power consumption of the motors involved. A system and integrated control viewpoint is necessary as a “component-oriented” and “single-loop-control” approach will not lead to the discovery...

  9. CFD comparison with centrifugal compressor measurements on a wide operating range

    Directory of Open Access Journals (Sweden)

    Arnou D.


    Full Text Available Centrifugal compressors are widely used in industrial applications thanks to their high efficiency. They are able to provide a wide operating range before reaching the flow barrier or surge limits. Performances and range are described by compressor maps obtained experimentally. After a description of performance test rig, this article compares measured centrifugal compressor performances with computational fluid dynamics results. These computations are performed at steady conditions with R134a refrigerant as fluid. Navier-Stokes equations, coupled with k-ε turbulence model, are solved by the commercial software ANSYS-CFX by means of volume finite method. Input conditions are varied in order to calculate several speed lines. Theoretical isentropic efficiency and theoretical surge line are finally compared to experimental data.

  10. The Three-Dimensional Numerical Simulation and Experimental Research on Screw Compressor

    Directory of Open Access Journals (Sweden)

    He Xueming


    Full Text Available This paper presents the mathematical model of screw compressors’ working process, in which the internal flow domains are divided into three kinds of fluids—the inlet fluid, the primitive volume fluid, and outlet fluid. Grid interface method and dynamic mesh technique of Computational Fluid Dynamics (CFD theory were utilized to simulate the suction, compression, and discharge process in order to model the dynamic characteristics of the flow domains in a screw compressor. To verify that the model is numerically accurate and the simulation method is effective, experiments on the pressure-volume changes in screw compressor were carried out. The result has shown that the simulation data is in good agreement with the experimental data. Therefore, the numerical calculation model and the simulation method can be very useful for the screw compressor design and research.

  11. Integration of MACBETH and COPRAS methods to select air compressor for a textile company

    Directory of Open Access Journals (Sweden)

    Nilsen Kundakcı


    Full Text Available The selection of air compressor is a Multiple Criteria Decision Making (MCDM problem including conflicting criteria and various alternatives. Selecting the appropriate air compressor is an important decision for the company as it affects the energy consumption and operating cost. To aid the decision making process in the companies, MCDM methods are proposed in the literature. In all MCDM methods, the main goal is to select the best alternative or to rank a set of given alternatives. In this paper, the air compressor is selected for a spinning mill of a textile company with an integrated approach based on MACBETH (Measuring Attractiveness by a Categorical Based Evaluation TecHnique and COPRAS (COmplex PRoportional ASsessment methods. MACBETH method is utilized to determine the weights of the criteria. Then COPRAS method is used to determine the ranking of the alternatives and select the best one.

  12. Model Reference Adaptive Control of the Air Flow Rate of Centrifugal Compressor Using State Space Method

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jaeyoung; Jung, Mooncheong; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of); Yi, Sun [North Carolina A and T State Univ., Raleigh (United States)


    In this study, a model reference adaptive controller is developed to regulate the outlet air flow rate of centrifugal compressor for automotive supercharger. The centrifugal compressor is developed using the analytical based method to predict the transient behavior of operating and the designed model is validated with experimental data to confirm the system accuracy. The model reference adaptive control structure consists of a compressor model and a MRAC(model reference adaptive control) mechanism. The feedback control do not robust with variation of system parameter but the applied adaptive control is robust even if the system parameter is changed. As a result, the MRAC was regulated to reference air flow rate. Also MRAC was found to be more robust control compared with the feedback control even if the system parameter is changed.

  13. Measuring Surface Pressure on Rotating Compressor Blades Using Pressure Sensitive Paint

    Directory of Open Access Journals (Sweden)

    Markus Pastuhoff


    Full Text Available Pressure sensitive paint (PSP was used to measure pressure on the blades of a radial compressor with a 51 mm inlet diameter rotating at speeds up to 50 krpm using the so called lifetime method. A diode laser with a scanning-mirror system was used to illuminate the paint and the luminescent lifetime was registered using a photo multiplier. With the described technique the surface-pressure fields were acquired for eight points in the compressor map, useful for general understanding of the flow field and for CFD validation. The PSP was of so called fast type, which makes it possible to observe pressure variations with frequencies up to several kHz. Through frequency spectrum analysis we were able to detect the pulsating flow frequency when the compressor was driven to surge.

  14. Conceptual Design of Automotive Compressor for Integrated Portable Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Ishak Muhammad Ikman


    Full Text Available This study introduces a new concept of portable air conditioner which integrated with some available components in automotive air conditioning system. This new idea intends to solve the storage problems as well as to reduce the price of current portable air conditioner since some devices could directly be used from the automotive air conditioning system. The primary emphasis of this study was on the modification of automotive compressor design so as the system may alternately be operated. The length of conventional compressor shaft is extended to place an additional clutch pulley, a drive plate and a clutch coil. The new concept particularly the shaft and pulley were analysed through slope deflection and computational finite element analyses. The result of engineering analyses exhibited that the new design of compressor shaft and clutch pulleys promote a low risk of failure as the data values recorded are lower than the critical value for each criterion investigated.

  15. Application of S1BYL2 to the AGARD WG18 compressor test cases (United States)

    Calvert, W. J.


    S1BYL2 is an inviscid-viscous blade-to-blade method for calculating the detailed aerodynamics and overall performance of compressor blades. It may be applied either on its own to predict the flow for individual blade sections, such as the midspan of a linear cascade, or in conjunction with a throughflow calculation to predict the performance of a complete axial compressor. New predictions for the V2 and ARL SL19 cascades and for the high speed compressor cases are presented. It is hoped that this will be one of many sets of calculations for these cases, so that an improved understanding of each case may be obtained, together with an appreciation of the strengths and weaknesses of different computational approaches.

  16. Numerical investigation & comparison of a tandem-bladed turbocharger centrifugal compressor stage with conventional design (United States)

    Danish, Syed Noman; Qureshi, Shafiq Rehman; EL-Leathy, Abdelrahman; Khan, Salah Ud-Din; Umer, Usama; Ma, Chaochen


    Extensive numerical investigations of the performance and flow structure in an unshrouded tandem-bladed centrifugal compressor are presented in comparison to a conventional compressor. Stage characteristics are explored for various tip clearance levels, axial spacings and circumferential clockings. Conventional impeller was modified to tandem-bladed design with no modifications in backsweep angle, meridional gas passage and camber distributions in order to have a true comparison with conventional design. Performance degradation is observed for both the conventional and tandem designs with increase in tip clearance. Linear-equation models for correlating stage characteristics with tip clearance are proposed. Comparing two designs, it is clearly evident that the conventional design shows better performance at moderate flow rates. However; near choke flow, tandem design gives better results primarily because of the increase in throat area. Surge point flow rate also seems to drop for tandem compressor resulting in increased range of operation.

  17. Discussion on back-to-back two-stage centrifugal compressor compact design techniques (United States)

    Huo, Lei; Liu, Huoxing


    Design a small flow back-to-back two-stage centrifugal compressor in the aviation turbocharger, the compressor is compact structure, small axial length, light weighted. Stationary parts have a great influence on their overall performance decline. Therefore, the stationary part of the back-to-back two-stage centrifugal compressor should pay full attention to the diffuser, bend, return vane and volute design. Volute also impact downstream return vane, making the flow in circumferential direction is not uniformed, and several blade angle of attack is drastically changed in downstream of the volute with the airflow can not be rotated to required angle. Loading of high-pressure rotor blades change due to non-uniformed of flow in circumferential direction, which makes individual blade load distribution changed, and affected blade passage load decreased to reduce the capability of work, the tip low speed range increases.

  18. Wavelength scaling of optimal hollow-core fiber compressors in the single-cycle limit. (United States)

    Granados, Eduardo; Chen, Li-Jin; Lai, Chien-Jen; Hong, Kyung-Han; Kärtner, Franz X


    We systematically investigate supercontinuum generation using three-dimensional numerical simulations of nonlinear femtosecond pulse propagation in hollow-core fibers (HCF) at different pump wavelengths ranging from 400 nm to 2 μm. A general design strategy for HCF compressors is presented, maximizing the spectral broadening while preserving high beam quality for given pump pulse energy, duration and wavelength. We show close fitting of the modeled results with simple analytical formulas, enabling the construction of high-energy pulse compressors at the wavelength range of interest. Based on the presented wavelength scaling study, we propose an orthogonally polarized two-color pumping scheme in a single HCF compressor for the coherent synthesis of the electric fields in the sub-cycle regime with mJ level energies.

  19. RF design of a C-band compact spherical RF pulse compressor for SXFEL (United States)

    Li, Zongbin; Fang, Wencheng; Gu, Qiang; Zhao, Zhentang


    A new C-band (5712 MHz) compact spherical radio frequency (RF) pulse compressor was designed for the Soft X-ray Free Electron Laser facility (SXFEL) at the Shanghai Institute of Applied Physics (SINAP), Chinese Academy of Sciences (CAS). Using only one high Q0 spherical RF resonant cavity which works on two TE113 modes and a dual-mode polarized coupler, this pulse compressor could achieve an average power gain of 3.8. Associated with the C-band accelerator, an energy gain of 1.85 with the coupling coefficient of 4.9 could be achieved. Particularly it could make the output power stable. This paper presents the scheme of the C-band spherical pulse compressor, as well as the RF design and details of the frequency sensitivities and machining considerations.

  20. A Solid-State Compressor for Integration of CO2 Removal and Reduction Assemblies (United States)

    Mulloth, Lila M.; Finn, John E.; Lung, Bernadette (Technical Monitor)


    Integration of CO2 removal and reduction assemblies in a spacecraft air revitalization system requires an interface with the functionality of a vacuum pump/compressor and a buffer tank. The compressor must meet the vacuum needs of the CO2 removal unit and the pressure needs of the CO2 reduction device, and must also store sufficient CO2 to accommodate the differences in cycle times of the two processes. In this presentation, we describe the design and operation of an adsorption-based device sized for use on the International Space Station. The adsorption compressor functions at a power level approximately ten times lower than a comparable mechanical compression/buffer tank system. The unit is also smaller, lighter, and quieter than its mechanical counterpart.

  1. Thermodynamic Model and Experimental Study of Oil-free Scroll Compressor (United States)

    Peng, Bin; Zhao, Shengxian; Li, Yaohong


    In order to study the performance characteristics of oil-free scroll compressor, this paper is based on the basic equation of circle involute profile, and uses the differential geometry theory to calculate the variation law of pressure with volume. Based on the basic law of thermodynamics, the thermodynamic model of the oil-free scroll compressor is established by considering the heat transfer model and the gas leakage model, considering the mass, energy conservation equation and gas state equation. The change of the mass flow rate of the gas in each chamber is obtained by solving the established model by using the improved Euler method. The experiment results show that with the increase of frequency, the temperature, the displacement and the power show a clear upward trend. The thermodynamic model has some guidance and reference for the development and performance analysis of oil-free scroll compressors.

  2. Characterization of sorption compressor for mixed refrigerant J-T cryocooler (United States)

    Mehta, Rohitkumar; Bapat, Shridhar; Atrey, Milind


    The requirement of a cryocooler with minimum vibrations for space borne system and highly sophisticated electronic devices for ground application, has led to the development of sorption compressor type J-T cryocooler. The adsorption capacity of any adsorbent material increases with an increase in pressure and decreases with an increase in temperature. In a Sorption compressor, adsorbed gases are desorbed in a confined volume by raising temperature of the sorption bed which results in increase in pressure of gas. A uniform temperature across the sorption bed ensures maximum discharge from the compressor amounting to higher flow rates and longer cycle time on account of reduced residual loading. In addition, it is also very important to determine the adsorption capacity of any material with respect to the gas or gases to be adsorbed as this varies with source of the adsorbent. The present work reports the characterization of a fully operational two-cell sorption compressor developed. The sorption compressor is characterized for discharge pressure variation with cycle time; this is essentially a function of a) the amount of adsorbent, b) the adsorption capacity for respective gas or gases, c) desorption temperature and its uniformity, and d) system dead volume. The present paper analyses these aspects theoretically and the results are compared with the experimental data obtained for individual gases as well as for gas mixtures. The effect of gas distribution on temperature uniformity across the bed and of heater power on high pressure generated is also studied. The paper also discusses the pressure profile obtained for a given amount of adsorbent for different gas or gas mixture. The work, based on the results obtained so far is being further extended for a four cell sorption compressor.

  3. Optimization of operating conditions for compressor performance by means of neural network inverse

    Energy Technology Data Exchange (ETDEWEB)

    Cortes, O.; Urquiza, G.; Hernandez, J.A. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62209, Cuernavaca (Mexico)


    A way to optimize the parameters (i.e. operating conditions), related to compressor performance, based on artificial neural network and the Nelder-Mead simplex optimization method is proposed. It inverts the neural network to find the optimum parameter value under given conditions (artificial neural network inverse, ANNi). In order to do so, first an artificial neural network (ANN) was developed to predict: compressor pressure ratio, isentropic compressor efficiency, corrected speed, and finally corrected air mass flow rate. Input variables for this ANN include: ambient pressure, ambient temperature, wet bulb temperature, cooler temperature drop, filter pressure drop, outlet compressor temperature, outlet compressor pressure, gas turbine net power, exhaust gas temperature, and finally fuel flow mass rate. For the network, a feed-forward with one hidden layer, a Levenberg-Marquardt learning algorithm, a hyperbolic tangent sigmoid transfer-function and a linear transfer-function were used. The best fitting with the training database was obtained with 12 neurons in the hidden layer. For the validation of present database, simulation and experimental database were in good agreement (R{sup 2}>0.99). Thus, the obtained ANN model can be used to predict the operating conditions when input parameters are well-known. Second, results from the ANNi that was developed also show good agreement with experimental and target data (error <0.1%), in this case, cooler temperature was found for a required efficiency. Therefore, the proposed methodology of ANNi can be applied to optimize the performance of the compressor with an elapsed time minor to 0.5 s. (author)

  4. PIV investigation of the flow induced by a passive surge control method in a radial compressor

    Energy Technology Data Exchange (ETDEWEB)

    Guillou, Erwann; Gancedo, Matthieu; Gutmark, Ephraim [University of Cincinnati, Department of Aerospace Engineering, Cincinnati, OH (United States); Mohamed, Ashraf [Honeywell Turbo Technologies, Greater Los Angeles, CA (United States)


    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 ratios. Unfortunately, increasing the impeller rotational speed of turbocharger radial compressors tends to reduce their range of operation, which is limited at low mass flow rate by the occurrence of surge. In order to extend the operability of turbochargers, compressor housings can be equipped with a passive surge control device such as a ''ported shroud.'' This specific casing treatment has been demonstrated to enhance the surge margin with minor negative impact on the compressor efficiency. However, the actual working mechanisms of the system remain not well understood. Hence, in order to optimize the design of the ported shroud, it is crucial to identify the dynamic flow changes induced by the implementation of the device to control instabilities. From the full dynamic survey of the compressor performance characteristics obtained with and without ported shroud, specific points of operation were selected to carry out planar flow visualization. At normal working, both standard and stereoscopic particle imaging velocimetry (PIV) measurements were performed to evaluate instantaneous and mean velocity flow fields at the inlet of the compressor. At incipient and full surge, phase-locked PIV measurements were added. As a result, satisfying characterization of the compressor instabilities was provided 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 mechanism was achieved. (orig.)

  5. PIV investigation of the flow induced by a passive surge control method in a radial compressor (United States)

    Guillou, Erwann; Gancedo, Matthieu; Gutmark, Ephraim; Mohamed, Ashraf


    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 ratios. Unfortunately, increasing the impeller rotational speed of turbocharger radial compressors tends to reduce their range of operation, which is limited at low mass flow rate by the occurrence of surge. In order to extend the operability of turbochargers, compressor housings can be equipped with a passive surge control device such as a "ported shroud." This specific casing treatment has been demonstrated to enhance the surge margin with minor negative impact on the compressor efficiency. However, the actual working mechanisms of the system remain not well understood. Hence, in order to optimize the design of the ported shroud, it is crucial to identify the dynamic flow changes induced by the implementation of the device to control instabilities. From the full dynamic survey of the compressor performance characteristics obtained with and without ported shroud, specific points of operation were selected to carry out planar flow visualization. At normal working, both standard and stereoscopic particle imaging velocimetry (PIV) measurements were performed to evaluate instantaneous and mean velocity flow fields at the inlet of the compressor. At incipient and full surge, phase-locked PIV measurements were added. As a result, satisfying characterization of the compressor instabilities was provided 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 mechanism was achieved.

  6. Investigation on the variation of pressure in the cylinder of the refrigerator compressor based on FSI model (United States)

    He, Zhilong; Jian, Zhifang; Wang, Tao; Li, Dantong; Peng, Xueyuan


    The performance of refrigerator compressor has a significant influence on the coefficient of performance of the refrigerator. In order to find out the main cause for the variation of the performance, this paper presents a three-dimensional fluid structure interaction (FSI) model of the refrigerator compressor and an experimental investigation to verify the model. To record the p-V indicator diagram, a refrigerator compressor was modified and the pressure sensor was installed. Based on the FSI model, the variation of pressure in the cylinder that influenced the performance of compressor was identified by varying working condition, rotating speed and refrigerant. The FSI model and result could provide useful information for both performance testing and optimization of compressor performance.

  7. Optical design and studies of a tiled single grating pulse compressor for enhanced parametric space and compensation of tiling errors (United States)

    Daiya, D.; Patidar, R. K.; Sharma, J.; Joshi, A. S.; Naik, P. A.; Gupta, P. D.


    A new optical design of tiled single grating pulse compressor has been proposed, set-up and studied. The parametric space, i.e. the laser beam diameters that can be accommodated in the pulse compressor for the given range of compression lengths, has been calculated and shown to have up to two fold enhancement in comparison to our earlier proposed optical designs. The new optical design of the tiled single grating pulse compressor has an additional advantage of self compensation of various tiling errors like longitudinal and lateral piston, tip and groove density mismatch, compared to the earlier designs. Experiments have been carried out for temporal compression of 650 ps positively chirped laser pulses, at central wavelength 1054 nm, down to 235 fs in the tiled grating pulse compressor set up with the proposed design. Further, far field studies have been performed to show the desired compensation of the tiling errors takes place in the new compressor.

  8. Stability analysis and testing of a train of centrifugal compressors for high pressure gas injection

    Energy Technology Data Exchange (ETDEWEB)

    Memmott, E.A. [Dresser-Rand Co., Olean, NY (United States)


    This paper describes the rotor dynamic stability analysis and the PTC-10 Class 1 test of a three body centrifugal compressor train for high pressure natural gas injection services. This train had a full load full pressure string test on hydrocarbon gases to a final discharge pressure of 500 BAR (7250 PSIA). Each compressor is of the back to back configuration, and is equipped with tilting pad seals, damper bearings, and a honeycomb labyrinth at the division wall with shunt holes. The driver is a gas turbine.

  9. Effect of ionization energy loss on plasma focus formation in an erosion-type magnetoplasma compressor

    Energy Technology Data Exchange (ETDEWEB)

    Kamrukov, A.S.; Kozlov, N.P.; Chuvashev, S.N.


    The equations of radiation magnetogasdynamics, together with the real flow pattern and experimental data, are used to analyze the processes taking place in the plasma focus of a magnetoplasma compressor. It is shown that the energy lost in multiple ionization plays a big role in the energy balance of the plasma in the compression region of an erosion-type magnetoplasma compressor. The mechanisms for energy conversion demonstrated here serve as a guide to ways of controlling the parameters of the plasma focus. 14 references.

  10. Numerical flow analysis of axial flow compressor for steady and unsteady flow cases (United States)

    Prabhudev, B. M.; Satish kumar, S.; Rajanna, D.


    Performance of jet engine is dependent on the performance of compressor. This paper gives numerical study of performance characteristics for axial compressor. The test rig is present at CSIR LAB Bangalore. Flow domains are meshed and fluid dynamic equations are solved using ANSYS package. Analysis is done for six different speeds and for operating conditions like choke, maximum efficiency & before stall point. Different plots are compared and results are discussed. Shock displacement, vortex flows, leakage patterns are presented along with unsteady FFT plot and time step plot.

  11. Feasibility of using adaptive logic networks to predict compressor unit failure

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, W.W.; Chungying Chu; Thomas, M.M. [Dendronic Decisions Limited, Edmonton (Canada)] [and others


    In this feasibility study, an adaptive logic network (ALN) was trained to predict failures of turbine-driven compressor units using a large database of measurements. No expert knowledge about compressor systems was involved. The predictions used only the statistical properties of the measurements and the indications of failure types. A fuzzy set was used to model measurements typical of normal operation. It was constrained by a requirement imposed during ALN training, that it should have a shape similar to a Gaussian density, more precisely, that its logarithm should be convex-up. Initial results obtained using this approach to knowledge discovery in the database were encouraging.

  12. Retrofitting of a liquefaction compressor for LNG; Ueberholung eines Verfluessigungsverdichters fuer LNG

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Horst [RWE WWE NS GmbH, Nievenheim (Germany). Fluessigerdgasanlage; Hallermayer, Andreas [Hoerbiger Service Central Europe (Germany). Business Development


    RWE operates a LNG plant for peak shaving at Dormagen-Nievenheim as part of the RWE high-pressure gas supply grid. The natural gas is liquefied on site. This requires a complex liquefaction plant whose key elements are a tank, a heat exchanger, and the compressor. The plant was constructed and commissioned in 1975. After a longish standstill period, it was modernized recently, and several minor defects were repaired. The repair process is described in this contribution. It comprised damage detection and repair and was a time-consuming process. On the other hand, it illustrates that piston compressors function very reliably if regular servicing is ensured. (orig.)

  13. Сomputational and experimental researches of ice pieces impact against a plate-imitator of a blade airfoil of an aircraft engine axial compressor

    Directory of Open Access Journals (Sweden)

    B. F. Shorr


    Full Text Available Ingestion of hailstones and shedding ice in operating aircraft engine can lead to damage of compressor rotating blades, as well as to change of gas-dynamic characteristics, and loss of engine thrust.The paper presents a computational and experimental study results of an ice impact against a thin edge of the steel plate, which simulates a compressor blade.Impacts of the ice bricks against the plate with a velocity corresponding to the circumference rate of blades rotation were realized by the pneumatic gunshots. The trials were carried out under various angles attack between the direction of the ice flight and the plate plane. The experiments has shown that on impact the ice brick is covered by numerous cracks and collapsed just at the very beginning of the interaction with a plate. Thus, a leading edge of the plate has a smoothly bending form without appearing cracks.For modeling the ice an isotropic elastoplastic material was chosen. Its failure was based on shear and rupture criteria. Two models of ice with different size of the yield point were used.The test results and their comparison with the numerical ones have shown the following: 1. Calculations of brick impact against a thin edge of the plate-imitator with accepted ice characteristics yield a correct qualitative picture of the plate damage, but lead to some undersizes of its leading edge bending.2. The ice design model with a larger yield point well reflects a character of the ice brick impact destruction as a formation of numerous cracks in it and splitting the piece into small particles, which was observed in the experiments. The model with smaller yield point shows the ice brick cutting into two parts without cracking.3. The plate damage considerably increases with increasing ice brick attack angle. Under a direct impact against the plate edge, the ice brick is cut into two halves, with no plastic deformations of the plate observed.4. Available results give the grounds to use

  14. Thermochemical surface engineering of steels

    DEFF Research Database (Denmark)

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

  15. Continuous steel production and apparatus (United States)

    Peaslee, Kent D [Rolla, MO; Peter, Jorg J [McMinnville, OR; Robertson, David G. C. [Rolla, MO; Thomas, Brian G [Champaign, IL; Zhang, Lifeng [Trondheim, NO


    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  16. Brazing titanium to stainless steel (United States)

    Batista, R. I.


    Titanium and stainless-steel members are usually joined mechanically for lack of any other effective method. New approach using different brazing alloy and plating steel member with nickel resolves problem. Process must be carried out in inert atmosphere.

  17. A tale of Wootz steel

    National Research Council Canada - National Science Library

    Ranganathan, S; Srinivasan, Sharada


    The extraordinary romance and thrilling adventure associated with the tale of wootz steel shows how Indian metallurgists were the world leaders in antiquity in the manufacture of this legendary high-grade steel...

  18. Fatigue damage of steel components

    DEFF Research Database (Denmark)

    Fæster, Søren; Zhang, Xiaodan; Huang, Xiaoxu


    Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials......Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials...


    The report gives results of an investigation of the operation of a centrifugal compressor--part of a chlorofluorocarbon (CFC)-114 chiller installation--with the new refrigerant hydrofluorocarbon (HFC)-236ea, a proposed alternative to CFC-114. A large set of CFC-236ea operating da...

  20. Numerical analysis of the transient flow in a scroll refrigeration compressor (United States)

    Sun, Shuaihui; Wu, Kai; Guo, Pengcheng; Luo, Xingqi


    In the present paper, the CFD technology is adopted to simulate the working process of a scroll refrigeration compressor with R22 as working fluid. The structural grids in the scroll compressor were updated continually during the solving process to cope with the movement boundaries of the fluid domain. The radial meshing clearance was 0.008 mm which was the same with that in the real prototype. The pressure, velocity and temperature distribution in chambers of compressor were computed. Also, the transient mass flux diagrams were calculated out. The results indicated that the pressure was asymmetrical in the two symmetrical suction chambers, because the suction port and passage were not absolutely symmetrical. The gradient of temperature was great in each working chamber due to leakage flow. Velocity vector distribution was asymmetrical in each pair of working chamber owing to the movement of orbiting scroll; the flow was complicated in the central working chamber. The movement of the orbiting scroll had different influence on the vortexes formation in each pair of compression chamber. The inlet and outlet mass flux fluctuated with the crank angle obviously. Because of the ‘cut-off’ of the refrigeration fluid in the suction chamber when the crank angle was larger than 220°, the inlet mass flux decreased remarkably. Finally, some useful advices were given to improve the performance of the scroll refrigeration compressor.

  1. Stirling-type pulse tube refrigerator (PTR) with cold compression: Cold compressor, colder expander (United States)

    Park, Jiho; Ko, Junseok; Cha, Jeongmin; Jeong, Sangkwon


    This research paper focuses on the performance prediction and its validation via experimental investigation of a Stirling-type pulse tube refrigerator (PTR) equipped with a cold linear compressor. When the working gas is compressed at cryogenic temperature, the acoustic power (PV power) can be directly transmitted through the regenerator to the pulsating tube without experiencing unnecessary precooling process. The required PV power generated by the linear compressor, furthermore, can be significantly diminished due to the relatively small specific volume of the working gas at low temperature. The PTR can reach lower temperature efficiently with higher heat lift at the corresponding temperature than other typical single-stage Stirling-type PTRs. Utilizing a cryogenic reservoir as a warm end and regulating the entire operating temperature range of the PTR will enable a PTR to operate efficiently under space environment. In this research, the experimental validation as a proof of concept was carried out to demonstrate the capability of PTR operating between 80 K and 40 K. The linear compressor was submerged in a liquid nitrogen bath and the lowest temperature was measured as 38.5 K. The test results were analyzed to identify loss mechanisms with the simple numerical computation (linear model) which considers the dynamic characteristics of the cold linear compressor with thermo-hydraulic governing equations for each of sub components of the PTR. All the mass flows and pressure waves were assumed to be sinusoidal.

  2. Experimental Study of Linear Compressor Driven Traveling-wave Thermo Acoustic Refrigerator (United States)

    Wu, Z.; Luo, E.; Dai, W.; Yu, G.


    The investigation on the performance of a traveling-wave thermoacoustic refrigerator driven by a self-made linear compressor is presented in this paper. The linear compressor is of moving-coil type, which has a moving coil, a piston with about 100 square centimeters cross section area, and a flexure bearing unit for piston support. The operating frequency can be adjusted to achieve a resonant status in order that the compressor can work with high electroacoustic efficiency. The thermoacoustic refrigerator operates on traveling-wave mode with acoustic power recovery. In the experiments, influence of different working frequencies on electroacoustic efficiency, lowest temperature, cooling power and COP is investigated. So far in the experiment with helium as working fluid, a lowest temperature of -29 °C is obtained, when the mean and oscillating pressures are 1.0MPa and 0.042MPa respectively and the temperature of room-temperature heat exchanger is kept around 15°C. And a maximum cooling power of about 28.5W@0°C is achieved under 1.5MPa mean pressure and 0.049MPa oscillating pressure. Besides, the performance of the linear compressor itself is also investigated, which is important for a reasonable evaluation of the refrigerator performance.

  3. Air Compressor Pressure Control System Based On Gearshift Integral PID Controller

    Directory of Open Access Journals (Sweden)

    PAN Chunyue


    Full Text Available The application of gearshift integral PID controller to air compressor pressure control system is introduced, Its kernel is single chip microcomputer PIC16F877.The design of hardware and solfware are introduced too. Practical application shows that this system has many advantages.

  4. Characteristics of an activated carbon monolith for a helium adsorption compressor

    NARCIS (Netherlands)

    Lozano-Castello, D.; Jorda-Beneyto, M.; Cazorla-Amoros, D.; Linares-Solano, A.; Burger, Johannes Faas; ter Brake, Hermanus J.M.; Holland, Herman J.


    An activated carbon monolith (ACM) with a high helium adsorption/desorption capacity, high density, low pressure drop, low thermal expansion and good mechanical properties was prepared and applied successfully in a helium adsorption compressor as a part of a 4.5 K sorption cooler. The activated

  5. A numerical and experimental investigation of the thermal control performance of a spaceborne compressor assembly (United States)

    Oh, Hyun-Ung; Lee, Min-Kyu; Shin, Somin; Hong, Joo-Sung


    Spaceborne pulse tube type cryocoolers are widely used for providing cryogenic temperatures for sensitive infrared, gamma-ray and X-ray detectors. Thermal control for the compressor of the cryocooler is one of the important technologies for the cooling performance, mission life time, and jitter stability of the cooler. The thermal design of the compressor assembly proposed in this study is basically composed of a heat pipe, a radiator, and a heater. In the present work, a method for heat pipe implementation is proposed and investigated to ensure the jitter stability of the compressor under the condition that one heat pipe is not working. An optimal design of the radiator that uses ribs for effective use by minimizing the temperature gradient on the radiator and reducing its weight is introduced. The effectiveness of the thermal design of the compressor assembly is demonstrated by on-orbit thermal analysis using the correlated thermal model obtained from the thermal balance test that is performed under a space simulating environment.

  6. A Gas Turbine Compressor Simulation Model for Inclusion of Active Control Strategies (United States)


    simulation for aircraft propulsion systems", ASME Paper 97-GT-333, Orlando (FL); Giannattasio, P., 1999, " Analisi di stabilitO di un sistema di...Dugundji, J., Greitzer, E.M., Epstein, A.h, 1991, "Dynamic Control of Centrifugal Compressor Surge Using Tailored Structures ", ASME Journal of

  7. Investigation on the electromagnetic centring technique in compressor with labyrinth seal structure (United States)

    Zhang, W.; Feng, C.; Cheng, J.; Feng, Q.; Wu, W.


    At present, the piston of compressors with labyrinth seal structure generally runs eccentrically, which causes uneven radial clearance, serious leakages and lower volumetric efficiency. This has become an urgent problem in the development of labyrinth compressors. In this study, electromagnetic levitation technology was introduced to achieve concentric centering between the piston and cylinder, and the conventional cantilever structure for the piston centering was replaced by a simple support structure using the through-piston rod. Furthermore, the simulation model of the electromagnetic centering system was established and the experimental prototype was built. The mathematical simulation model was verified by comparing simulated and tested results. Then, the centering effect of the system was assessed and the variation of the leakage in the compressor was studied by models using dynamic mesh technology. The results showed that the radial clearance between piston and cylinder can be maintained in the range of -0.3 mm to 0.3 mm through the electromagnetic centering control. In addition, the inner leakage of the compressor was quite appreciable without the electromagnetic control. However, it was reduced by 1.8 times with the introduction of the electromagnetic control. Thus, it can be concluded that the precise centering between the piston and the cylinder can be achieved by the introduction of the electromagnetic centering technique.

  8. Predictability of rotating stall and surge in a centrifugal compressor stage with dynamic simulations

    NARCIS (Netherlands)

    González Díez, N.; Smeulers, J.P.M.; Tapinassi, L.; Scotti del Greco, A.; Toni, L.


    A testing campaign performed on a centrifugal compressor test-loop showed that multiple areas of stable operation existed that were not expected. It was shown during the tests that after a first region of instability at low flow rates, a second stable region would appear at even lower flow rates.

  9. Perspectives of Phase-Portraits in the Detection of Compressor Instabilities-Inception of Stall (United States)


    della teoria del caos Young eds. Springer, Berlin 1981, page 366. deterministo." PhD Thesis, Universita Degli Studi Di 36. Theiler J.; "Estimating...34, Funzionamento di un Compressore Assiale in Ann. Math. 37, page 645. Prossimita’ dello stallo rotante secondo le tecniche della Teoria dcl Caos

  10. Linearization of Optimal Compressor Function and Design of Piecewise Linear Compandor for Gaussian Source

    Directory of Open Access Journals (Sweden)

    ANTIC, D.


    Full Text Available The constraints on the quantizer model are usually related to how complex the model can be designed and implemented. For the given bit rate, it is desirable to provide the highest possible signal to quantization noise ratio (SQNR with reasonable complexity of a quantizer model. In order to avoid the influence of compressor function nonlinearity and the difficulties appearing in implementing and designing, especially in the Gaussian probability density function case, in this paper we linearize the optimal compressor function within the segments. We take advantage of piecewise linearization of the optimal compressor function, as a convenient solution for less complex designing compared to the asymptotically optimal compandor, and we provide performances close to the ones of the asymptotically optimal compandor. This makes our model useful in applications where the design and implementation complexity is a decisive factor. We propose a piecewise linear compandor (PLC with an equal number of reproduction levels per nonuniformly spaced segments, where the segment thresholds are allotted to the equidistant optimal compressor function values. We study how the number of segments affects SQNR of the PLC. Features of the proposed PLC indicate its theoretical and practical significance in quantization of Gaussian source signals.

  11. Statistical properties of the Stokes signal in stimulated Brillouin scattering pulse compressors

    NARCIS (Netherlands)

    Velchev, I.; Ubachs, W.M.G.


    Spontaneous scattering noise is incorporated as a build-up source in a fully transient stimulated Brillouin scattering (SBS) model. This powerful simulation tool is successfully applied for a quantitative investigation of the fluctuations in the output pulse duration of SBS pulse compressors. The

  12. Combined Numerical and Analytical Analysis of an Oil-free Twin Screw Compressor (United States)

    Kennedy, Stuart; Wilson, Maria; Rane, Sham


    The application of three-dimensional computational fluid dynamics in twin-screw compressors provides an outstanding opportunity for developers to gain an understanding of the complex internal flow phenomena occurring within the machine. Equipped with this knowledge, design parameters, such as clearances and port geometry, can be optimised, to enhance performance. However, as with all modelling, be it numerical or analytical, a high degree of certainty in the accuracy of the results is necessary. This paper presents the results of a study of oil-free twin screw compressor in which the results of two modelling techniques are compared. The modelling techniques used are an analytical non-dimensional thermodynamic chamber model and a numerical computational fluid dynamic model. The paper presents an overview of an oil-free twin screw compressor machine, before describing important operating characteristics and the modelling techniques used. To validate, both models are compared against historical test data, this validation indicated the chamber model is more accurate. Following this, the focus will be on the comparison of key performance indicators, including, volume flow rate, volumetric efficiency, indicated power, and discharge temperature at varying duty points. The paper concludes that the difference between both models decreases as the compressor operating speed increases, although the level of variance is dependent on pressure ratio.

  13. Centrifugal compressor fault diagnosis based on qualitative simulation and thermal parameters (United States)

    Lu, Yunsong; Wang, Fuli; Jia, Mingxing; Qi, Yuanchen


    This paper concerns fault diagnosis of centrifugal compressor based on thermal parameters. An improved qualitative simulation (QSIM) based fault diagnosis method is proposed to diagnose the faults of centrifugal compressor in a gas-steam combined-cycle power plant (CCPP). The qualitative models under normal and two faulty conditions have been built through the analysis of the principle of centrifugal compressor. To solve the problem of qualitative description of the observations of system variables, a qualitative trend extraction algorithm is applied to extract the trends of the observations. For qualitative states matching, a sliding window based matching strategy which consists of variables operating ranges constraints and qualitative constraints is proposed. The matching results are used to determine which QSIM model is more consistent with the running state of system. The correct diagnosis of two typical faults: seal leakage and valve stuck in the centrifugal compressor has validated the targeted performance of the proposed method, showing the advantages of fault roots containing in thermal parameters.

  14. The intrinsic equation of planar curves and the geometry of the scroll compressor

    DEFF Research Database (Denmark)

    Gravesen, Jens; Henriksen, Christian


    The scroll compressor is an ingenious machine used for compressing air or refrigerant, which was originally invented in 1905 by Léon Creux. The classical design consist of two nested identical scrolls given by circle involutes, one of which is rotated through 180° with respect to the other...

  15. A pilot study to assess residential noise exposure near natural gas compressor stations. (United States)

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


    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 noise for homes noise for homes noise exposures. Larger studies are needed to confirm these findings and evaluate potential health impacts and protection measures.

  16. Influence of the working gas composition on the Magnetoplasma Compressor properties (United States)

    Dojčinović, I. P.; Kuraica, M. M.; Astashynski, V. M.; Purić, J.


    Plasma compression flows from Magnetoplasma Compressor (MPC) operating in different gases (argon, nitrogen and hydrogen) were studied. Discharge current and the voltage between the MPC electrodes were measured using the Rogovski coil and the voltage RC-divider, respectively. Using IMACON 790 high speed camera operating in frame and streak mode, the development of breakdown and compression plasma flow, were determined.

  17. Pulse-periodic iodine photodissociation laser pumped with radiation from magnetoplasma compressors (United States)

    Kashnikov, G. N.; Orlov, V. K.; Panin, A. N.; Piskunov, A. K.; Reznikov, V. A.


    The design and operation of an iodine photodissociation laser, pumped by radiation from magnetoplasma compressors, are described. The laser uses a closed-circulation system with C3F7I as the working gas. Repetitive-pulse operation has been achieved with an interval between pulses of 1 minute, a lasing energy of 110 J, and a pulse duration of 30 microseconds.

  18. Calculation of the dynamics of compression plasma flows in a magnetoplasma compressor operating on air (United States)

    Ananin, S. I.


    A two-dimensional model for describing the dynamics of partially ionized air compression plasma flows, generated by a magnetoplasma compressor, is proposed. The model is based on the large-particle method together with the introduction of a magnetic field. The results of calculations of the dynamics and structure of compression plasma flows are studied and compared with experimental data.

  19. Calculation of the dynamics of compression plasma flows in a magnetoplasma compressor operating on air

    Energy Technology Data Exchange (ETDEWEB)

    Ananin, S.I.


    This paper presents a two-dimensional model for describing the dynamics of partially ionized air compression plasma flows, generated by a magnetoplasma compressor. The model is based on the large-particle method together with the introduction of a magnetic field. The results of calculations of the dynamics and structure of compression plasma flows are studied and compared with experimental data.

  20. The development of an air injection system for the forced response testing of axial compressors

    CSIR Research Space (South Africa)

    Wegman, Erik J


    Full Text Available of ASME Turbo Expo 2013: Power for Land, Sea and Air: GT2013, San Antonio, Texas, USA, 3-7 June 2013 THE DEVELOPMENT OF AN AIR INJECTION SYSTEM FOR THE FORCED RESPONSE TESTING OF AXIAL COMPRESSORS E Wegman and G Snedden CSIR, Pretoria, South...

  1. Title V Operating Permit: XTO Energy, Inc. - Little Canyon Unit Compressor Station (United States)

    Initial Title V Operating Permit (Permit Number: V-UO-000016-2006.00), Response to Public Comments and the Administrative Permit Record for the XTO Energy, Inc., Little Canyon Unit Compressor Station, located on the Uintah and Ouray Indian Reservation.


    Directory of Open Access Journals (Sweden)

    L. V. Dubynets


    Full Text Available The new scheme of protection of the engine DK 409 (DK406 of the compressor (EK 7B on electric trains of series ER2 is offered. Such a scheme provides accurate and reliable protection of the electric machine, unites in itself the protection functions both under overloads with long-term currents and in case of short-circuit.

  3. Compressibility and Turbulence Effects Due to Airfoil Clocking in Axial Compressors (United States)

    Dorney, Daniel J.; Sharma, Om P.; GundyBurlet, Karen L.; George, Michael W. (Technical Monitor)


    Axial compressors have inherently unsteady flow fields because of relative motion between rotor and stator airfoils. This relative motion leads to viscous and inviscid (potential) interactions between blade rows. As the number of stages increases in a turbomachine, the buildup of convected wakes can lead to progressively more complex wake/wake and wake/airfoil interactions. Variations in the relative circumferential positions of stators or rotors can change these interactions, leading to different unsteady forcing functions on airfoils and different compressor efficiencies. In addition, as the Mach number increases the interaction between blade rows is intensified due to potential effects. The current study uses an unsteady, two-dimensional Navier-Stokes approach to investigate the unsteady aerodynamics of stator clocking in a 1-1/2 stage compressor, typical of high-pressure compressors used in advanced commercial jet engines. The effects of turbulence are modeled with both algebraic and two-equation models. Results include surface pressures, efficiencies, boundary layer quantities and turbulence quantities. In addition, the growth of turbulence and the effects of compressibility on airfoil are discussed.

  4. Hub and shroud fillets influence on the radial compressor stage efficiency

    Directory of Open Access Journals (Sweden)

    Syka Tomáš


    Full Text Available Article describes numerical simulations of an air flow in the radial compressor stage in the NUMECA CFD software. During the tasks evaluating the stepped and straight impeller seals and hub and shroud fillets influence on working characteristics and flow field was observed. Also the CFD results comparison with results from the empiric design tool and the measurement is described.

  5. Design, Test, and Evaluation of a Transonic Axial Compressor Rotor with Splitter Blades (United States)


    produce inlet and outlet velocity triangles. From these velocity triangles, overall stage flow turning angles were calculated and used to guide the...Supersonic Axial Compressor Stage Incorporating Splitter Vanes ..............................................................1 2. Newer Developments...9 Figure 6. Rotor tip section inlet velocity triangle ............................................................10 Figure 7

  6. Study of High Efficiency Flow Regulation of VIGV in Centrifugal Compressor

    Directory of Open Access Journals (Sweden)

    Chunjun Ji


    Full Text Available Variable inlet guide vane (VIGV is used to control the mass flow and generate prewhirl in centrifugal compressors. Due to the tip clearance of the guide vanes and the defect of the traditional guide vane profiles, the mass flow regulation of VIGV is limited, resulting in a large waste of compressed gas. Two kinds of inlet flow channels were proposed to eliminate the influence of tip clearance. These structures were numerically investigated at different setting angles. The results show that the improved channels not only expand the range of mass flow regulation, but also reduce the power and increase the efficiency of the compressor. Ten kinds of guide vane profiles, including different thickness distribution, camber line profile, were selected to compare with the original one and with each other. In the premise of ensuring the performance of compressor, the best guide vane profile was selected. The results show that reducing the guide vane thickness, increasing the guide vane camber angle, and increasing the distance between the maximum camber position and the leading edge of guide vane can help expand the range of mass flow regulation. The achievement of this research can effectively improve the flow regulation ability of VIGV and the performance of compressor.

  7. On the effect of pulsating flow on surge margin of small centrifugal compressors for automotive engines

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, J.; Climent, H.; Guardiola, C.; Tiseira, A. [CMT-Motores Termicos, Universidad Politecnica de Valencia (Spain); Camino de Vera s/n, E 46022, Valencia (Spain)


    Surge is becoming a limiting factor in the design of boosting systems of downsized diesel engines. Although standard compressor flowcharts are used for the selection of those machines for a given application, on-engine conditions widely differ from steady flow conditions, thus affecting compressor behaviour and consequently surge phenomenon. In this paper the effect of pulsating flow is investigated by means of a steady gas-stand that has been modified to produce engine-like pulsating flow. The effect of pressure pulses' amplitude and frequency on the compressor surge line location has been checked. Results show that pulsating flow in the 40-67 Hz range (corresponding to characteristic pulsation when boosting an internal combustion engine) increases surge margin. This increased margin is similar for all the tested frequencies but depends on pulsation amplitude. In a further step, a non-steady compressor model is used for modelling the tests, thus allowing a deeper analysis of the involved phenomena. Model results widely agree with experimental results. (author)

  8. Geometric Optimization of Turbocharger Compressor and Its Influence on Engine Performance

    Directory of Open Access Journals (Sweden)

    Zhang Fangming


    Full Text Available This paper consists of two parts: aerodynamic and mechanical multi-objective optimization for centrifugal compressor impeller through combining the three dimensional fluid dynamic simulation module CFX 16.1, the static structure in the ANSYS Workbench and the optimization software optiSLang; and a comparison and analysis of the effects of the optimized compressor on the engine performance by the one dimensional simulation tool GT-Power. In the process of optimization, the compressor design point is regarded as the optimizing point, while impeller blades and hub line were parameterized through the Bezier curve. Pressure ratio, isentropic efficiency, quality and maximum deformation and maximum internal stress of the impeller were defined as the output conditions. MOP module was then adopted in optiSLang for the parameters sensitivity analysis and mapping relationship modeling between the impeller parameters and the objective functions. The genetic algorithm is applied to find out and validate the optimal design. Through 1D simulation tool GT-Power, the influence of the optimized compressor on rotational speed of the turbocharger, backpressure and pumping loss under different engine operating conditions is analyzed and compared.

  9. Single and combined fault diagnosis of reciprocating compressor valves using a hybrid deep belief network

    NARCIS (Netherlands)

    Tran, Van Tung; Thobiani, Faisal Al; Tinga, Tiedo; Ball, Andrew David; Niu, Gang


    In this paper, a hybrid deep belief network is proposed to diagnose single and combined faults of suction and discharge valves in a reciprocating compressor. This hybrid integrates the deep belief network structured by multiple stacked restricted Boltzmann machines for pre-training and simplified

  10. Extensive dynamic analyses to achieve stringent noise and vibration levels for an offshore reciprocating compressor system

    NARCIS (Netherlands)

    Eijk, A.; Elferink, H.


    During the lifetime of an existing gas well, located in the D15FA/FB field in the North Sea, the pressure has dropped and consequently production is reduced. A depletion compressor had to be added to this existing platform to increase the production. This sounds easy but has been very challenging

  11. Solutions developed to meet very stringent requirements for an offshore application of a reciprocating compressor system

    NARCIS (Netherlands)

    Elferink, H.; Eijk, A.


    During the lifetime of an existing gas well, located in the D15FA/FB field in the North Sea, the pressure has dropped and consequently production is reduced. A depletion compressor must be added therefore to this existing platform to increase the production. This sounds easy but has been very

  12. Rotary-Wing Relevant Compressor Aero Research and Technology Development Activities at Glenn Research Center (United States)

    Welch, Gerard E.; Hathaway, Michael D.; Skoch, Gary J.; Snyder, Christopher A.


    Technical challenges of compressors for future rotorcraft engines are driven by engine-level and component-level requirements. Cycle analyses are used to highlight the engine-level challenges for 3000, 7500, and 12000 SHP-class engines, which include retention of performance and stability margin at low corrected flows, and matching compressor type, axial-flow or centrifugal, to the low corrected flows and high temperatures in the aft stages. At the component level: power-to-weight and efficiency requirements impel designs with lower inherent aerodynamic stability margin; and, optimum engine overall pressure ratios lead to small blade heights and the associated challenges of scale, particularly increased clearance-to-span ratios. The technical challenges associated with the aerodynamics of low corrected flows and stability management impel the compressor aero research and development efforts reviewed herein. These activities include development of simple models for clearance sensitivities to improve cycle calculations, full-annulus, unsteady Navier-Stokes simulations used to elucidate stall, its inception, and the physics of stall control by discrete tip-injection, development of an actuator-duct-based model for rapid simulation of nonaxisymmetric flow fields (e.g., due inlet circumferential distortion), advanced centrifugal compressor stage development and experimentation, and application of stall control in a T700 engine.

  13. Operation Test of the Supercritical CO{sub 2} Compressor Supported with Active Magnetic Bearing

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jae Eun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Seong Kuk; Lee, Jeong IK [KAIST, Daejeon (Korea, Republic of)


    In this paper, the operation test status of the SCIEL sCO{sub 2} AMB Compressor is briefly described. The Supercritical CO{sub 2} Brayton Cycle Integral Experiment Loop (SCIEL) has been installed in Korea Atomic Energy Research Institute (KAERI) to develop the element technologies for the sCO{sub 2} cycle power generation system. The operation of the SCIEL has mainly focused on sCO{sub 2} compressor development and establishing sCO{sub 2} system control logic. The installation of the SCIEL low compression loop was finished in December 2014 and research team succeeded in generating electric power on the supercritical state of the CO{sub 2} in May 2015. The SCIEL has been built in KAERI to develop the element technologies and the system control logics for the sCO{sub 2} cycle power conversion unit of the next generation reactor. For the stable operation of the sCO{sub 2} compressor under high rotational speed, the AMB sCO{sub 2} compressor was developed and achieved the maximum 40,000 rpm.

  14. Thermally Stable Nanocrystalline Steel (United States)

    Hulme-Smith, Christopher Neil; Ooi, Shgh Woei; Bhadeshia, Harshad K. D. H.


    Two novel nanocrystalline steels were designed to withstand elevated temperatures without catastrophic microstructural changes. In the most successful alloy, a large quantity of nickel was added to stabilize austenite and allow a reduction in the carbon content. A 50 kg cast of the novel alloy was produced and used to verify the formation of nanocrystalline bainite. Synchrotron X-ray diffractometry using in situ heating showed that austenite was able to survive more than 1 hour at 773 K (500 °C) and subsequent cooling to ambient temperature. This is the first reported nanocrystalline steel with high-temperature capability.

  15. A-3 steel work completed (United States)


    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  16. Technology’s present situation and the development prospects of energy efficiency monitoring as well as performance testing & analysis for process flow compressors (United States)

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


    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.

  17. A computational analysis of the aerodynamic and aeromechanical behavior of the purdue multistage compressor (United States)

    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

  18. FOREWORD: 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF2013) (United States)

    Wu, Yulin; Wang, Zhengwei; Yuan, Shouqi; Shi, Weidong; Liu, Shuhong; Luo, Xingqi; Wang, Fujun


    The 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF 2013) was held in Beijing, China, 19-22 September 2013, which was jointly organized by Tsinghua University and Jiangsu University. The co-organizers were Zhejiang University, Zhejiang Sci-Tech University, The State Key Laboratory of Hydroscience and Engineering, The State Key Laboratory of Automotive Safety and Energy and Beijing International Science and Technology Cooperation Base for CO2 Utilization and Reduction. The sponsor of the conference was Concepts NREC. The First International Conference on Pumps and Systems (May 1992), the Second International Conference on Pumps and Fans (October 1995), the Third International Conference on Pumps and Fans (October 1998), and the Fourth International Conference on Pumps and Fans (26-29 August 2002) were all held in Beijing and were organized by the late famous Chinese professor on fluid machinery and engineering, Professor Zuyan Mei of Tsinghua University. The conference was interrupted by the death of Professor Mei in 2003. In order to commemorate Professor Mei, the organizing committee of ICPF decided to continue organizing the conference series. The Fifth Conference on Pumps and Systems (2010 ICPF) took place in Hangzhou, Zhejiang Province, China, 18-21 October 2010, and it was jointly organized by Zhejiang University and Tsinghua University. With the development of renewable energy and new energy in China and in the world, some small types of compressor and some types of pump, as well as wind turbines are developing very fast; therefore the ICPF2013 conference included compressors and wind turbines. The theme of the conference was the application of renewable energy of pumps, compressors, fans and blowers. The content of the conference was the basic study, design and experimental study of compressors, fans, blowers and pumps; the CFD application on pumps and fans, their transient behavior, unsteady flows and multi-phase flow

  19. Effect of self recirculation casing treatment on the performance of a turbocharger centrifugal compressor (United States)

    Gancedo, Matthieu

    Increase in emission regulations in the transport industry brings the need to have more efficient engines. A path followed by the automobile industry is to downsize the size of the internal combustion engine and increase the air density at the intake to keep the engine power when needed. Typically a centrifugal compressor is used to force the air into the engine, it can be powered from the engine shaft (superchargers) or extracting energy contained into the hot exhaust gases with a turbine (turbochargers). The flow range of the compressor needs to match the one of the engine. However compressors mass flow operating range is limited by choke on the high end and surge on the low end. In order to extend the operation at low mass flow rates, the use of passive devices for turbocharger centrifugal compressors was explored since the late 80's. Hence, casing treatments including flow recirculation from the inducer part of the compressor have been shown to move the surge limit to lower flows. Yet, the working mechanisms are still not well understood and thus, to optimize the design of this by-pass system, it is necessary to determine the nature of the changes induced by the device both on the dynamic stability of the pressure delivery and on the flow at the inlet. The compressor studied here features a self-recirculating casing treatment at the inlet. The recirculation passage could be blocked to carry a direct comparison between the cases with and without the flow feature. To grasp the effect on compressor stability, pressure measurements were taken in the different constituting elements of the compressor. The study of the mean pressure variations across the operating map showed that the tongue region is a limiting element. Dynamic pressure measurements revealed that the instabilities generated near the inducer when the recirculation is blocked increase the overall instability levels at the compressor outlet and propagating pressure waves starting at the tongue occurred

  20. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa (United States)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam


    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  1. Compressor calorimeter performance of refrigerant blends: Comparative methods and results for a refrigerator/freezer application (United States)

    Rice, C. K.; Sand, J. R.


    A protocol was developed to define calorimeter operating pressures for nonazeotropic refrigerant mixtures (NARM's) which corresponded with the saturated evaporator and condenser temperatures commonly used for pure refrigerants. Compressor calorimeter results were obtained using this equivalent-mean-temperature (EMT) approach and a generally applied Association of Home Appliance Manufacturers (AHAM) procedure at conditions characteristic of a domestic refrigerator-freezer application. Tests with R-12 and two NARM's indicate that compressor volumetric and isentropic efficiencies are nearly the same for refrigerants with similar capacities and pressure ratios. The liquid-line temperature conditions specified in the AHAM calorimeter rating procedure for refrigerator-freezer compressors were found to preferentially derate NARM performance relative to R-12. Conversion of calorimeter data taken with a fixed liquid-line temperature to a uniform minimal level of condenser subcooling is recommended as a fairer procedure when NARM's are involved. Compressor energy-efficiency-ratio (EER) and capacity data measured as a result of the EMT approach were compared to system performance calculated using an equivalent heat exchanger loading (EHXL) protocol based on a Lorenz-Meutzner (L-M) refrigerator-freezer modeling program. The EHXL protocol was used to transform the calorimeter results into a more relevant representation of potential L-M cycle performance. The EMT method used to set up the calorimeter tests and the AHAM liquid-line conditions combined to significantly understate the cycle potential of NARM's relative to that predicted at the more appropriate EHXL conditions. Compressor conditions representative of larger heat exchanger sizes were also found to give a smaller L-M cycle advantage relative to R-12.

  2. Technical analysis of utilization suitability of various wind rotor’s types for compressor’s power driving

    Directory of Open Access Journals (Sweden)

    Radim Rybár


    Full Text Available Conception is from the converting of wind energy, which flows across the wind turbine in mechanic work needed for compressor working. The wind motor one part of energy transform into mechanical work, part of energy is unused and part of energy of stead flow is transformed into eddy after wind rotor.The aim was rendering of technical analysis for equipment, which would use the wind with parameters for chosen area and whole unit would supply power in peak demand. Unit consists of wind turbine, which pushes compressor. Compressor pumps air into the compressed air storage. The air is used for power producing in time of peak demand.

  3. Hydrogen Compressor Reliability Investigation and Improvement. Cooperative Research and Development Final Report, CRADA Number CRD-13-514

    Energy Technology Data Exchange (ETDEWEB)

    Terlip, Danny [National Renewable Energy Lab. (NREL), Golden, CO (United States)


    Diaphragm compressors have become the primary source of on-site hydrogen compression for hydrogen fueling stations around the world. NREL and PDC have undertaken two studies aimed at improving hydrogen compressor operation and reducing the cost contribution to dispensed fuel. The first study identified the failure mechanisms associated with mechanical compression to reduce the maintenance and down-time. The second study will investigate novel station configurations to maximize hydrogen usage and compressor lifetime. This partnership will allow for the simulation of operations in the field and a thorough analysis of the component failure to improve the reliability of diaphragm compression.

  4. Guns, Germs and Steel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 1. Guns, Germs and Steel - A Short History of Everybody for the Last 13,000 years. Suri Venkatachalam. Book Review Volume 6 Issue 1 January 2001 pp 84-88. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Japan steel mill perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)


    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  6. Braze alloy spreading on steel (United States)

    Siewert, T. A.; Heine, R. W.; Lagally, M. G.


    Scanning electron microscopy (SEM) and Auger electron microscopy (AEM) were employed to observe elemental surface decomposition resulting from the brazing of a copper-treated steel. Two types of steel were used for the study, stainless steel (treated with a eutectic silver-copper alloy), and low-carbon steel (treated with pure copper). Attention is given to oxygen partial pressure during the processes; a low enough pressure (8 x 10 to the -5th torr) was found to totally inhibit the spreading of the filler material at a fixed heating cycle. With both types of steel, copper treatment enhanced even spreading at a decreased temperature.

  7. Comparison of nonwoven fiberglass and stainless steel microfiber media in aerosol coalescence filtration (United States)

    Manzo, Gabriel

    Coalescing filters are used to remove small liquid droplets from air streams. They have numerous industrial applications including dehumidification, cabin air filtration, compressed air filtration, metal working, CCV, and agriculture. In compressed air systems, oils used for lubrication of compressor parts can aerosolize into the main air stream causing potential contamination concerns for downstream applications. In many systems, humid air can present problems to sensitive equipment and sensors. As the humid air cools, small water drops condense and can disrupt components that need to be kept dry. Fibrous nonwoven filter media are commonly used to coalesce small drops into larger drops for easier removal. The coalescing performance of a medium is dependent upon several parameters including permeability, porosity, and wettability. In many coalescing filters, glass fibers are used. In this work, the properties of steel fiber media are measured to see how these properties compare to glass fiber media. Steel fiber media has different permeability, porosity and wettability to oil and water than fiber glass media. These differences can impact coalescence performance. The impact of these differences in properties on coalescence filtration performance was evaluated in a coalescence test apparatus. The overall coalescence performance of the steel and glass nonwoven fiber media are compared using a filtration efficiency and filtration index. In many cases, the stainless steel media performed comparably to fiber glass media with efficiencies near 90%. Since stainless steel media had lower pressure drops than fiber glass media, its filtration index values were significantly higher. Broader impact of this work is the use of stainless steel fiber media as an alternative to fiber glass media in applications where aerosol filtration is needed to protect the environment or sensitive equipment and sensors.

  8. Vibro-acoustic methods for the determination of the technical state of a refrigeration piston compressor. A check-up for the compressor. Vibroakustische Verfahren zur Bestimmung des technischen Zustandes eines Kaeltekolbenverdichters. Ein Check-up fuer den Verdichter

    Energy Technology Data Exchange (ETDEWEB)

    Milowanow, V.I.; Lopatinskaja, E.S.


    Independent of the kind of refrigeration plant the actual service life is limited by the service life of the compressor. In case of refrigeration machinery with small-type refrigeration compressors for refrigerated transport systems a periodical check of the system before setting out is particularly important. A spectral analysis process is recommended for the diagnosis. But due to the particularities of the plants this is only suited for systems for vibroacoustic diagnosis. This technique is presented using charts and diagrams. (BWI).

  9. 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 (United States)

    Azizi, Mohammad Ali; Brouwer, Jacob


    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.

  10. Control and performance improvements of a pulse compressor in use for testing accelerating structures at high power

    Directory of Open Access Journals (Sweden)

    Benjamin Woolley


    Full Text Available New developments relating to compact X-band, SLED-I type pulse compressors being developed at CERN for testing high gradient structures are described. Pulse compressors of interest take rf pulses from one or more high power klystrons with duration typically >1.5  μs and deliver up to 5 times the input power for a shorter duration <250  ns. Time domain models for pulse compressor operation with low level rf (LLRF control have been developed. Input drive amplitude and phase for each pulse is evolved with a control algorithm from the pulse compressor output for previous pulses. The goal is to deliver precise amplitude for pulses to test stands and precise amplitude and phase for pulses to accelerator systems. Control algorithms have been developed and validated experimentally.

  11. Phase Modulator Programming to Get Flat Pulses with Desired Length and Power from the CTF3 Pulse Compressors

    CERN Document Server

    Shaker, Seyd Hamed; Skowronski, Piotr; Syratchev, Igor; Tecker, Frank


    The pulse compressor is located after the klystron to increase the power peak by storing the energy at the beginning and releasing it near the end of klystron output pulse. In the CTF3 pulse compressors a doubling of the peak power is achieved according to our needs and the machine parameters. The magnitude of peak power, pulse length and flatness can be controlled by using a phase modulator for the input signal of klystrons. A C++ code is written to simulate the pulse compressor behaviour according to the klystron output pulse power. By manually changing the related parameters in the code for the best match, the quality factor and the filling time of pulse compressor cavities can be determined. This code also calculates and sends the suitable phase to the phase modulator according to the klystron output pulse power and the desired pulse length and peak power

  12. CO2 Compressor Requirements for Integration of Space Station Carbon Dioxide Removal and Carbon Dioxide Reduction Assemblies (United States)

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


    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.

  13. Characterization of Aerodynamic Forcing Functions for Embedded Rotor Resonant Response in a Multistage Compressor (United States)

    Kormanik, Nicholas J., III

    There are two main objectives associated with this research: The first portion examines the flow field within the embedded stage of the Purdue 3-Stage Axial Compressor and the aerodynamics responsible for exciting a forced response condition on an embedded rotor. The second portion focuses on the upgrades made to the facility to accommodate a new compressor design, as well as the basic performance characteristics that were acquired for the baseline model. With the first phase of this research endeavor, the first chord-wise bending vibratory mode was examined with a standard stator 1 (S1) blade-count configuration (44 vanes). Next, a reduced S1 blade-count configuration (38 vanes) was implemented to observe how a reduced vane count might impact the forced response at the first torsion vibratory mode. To capture these aerodynamic considerations, stagnation pressure and thermal anemometry probes were used throughout the embedded stage to provide a detailed picture of the influence associated with rotor and stator wakes. These data were also used to observe the potential field effects from the downstream blade-rows. The overall purpose of this campaign was to provide accurate and reliable dataset that could be used to further enhance and validate the computational aeromechanics tools used by the GUIde V consortium, the sponsors for this research. The second phase of this involves the redesign of the Purdue 3-Stage Axial Compressor Facility to accommodate a new compressor, designed by Rolls-Royce, that requires higher mass flow rates, pressure ratios, speeds, and temperatures. Along with many of the mechanical upgrades associated with an adaptation of the driveline and throttle system, health-monitoring upgrades were made to improve the safety and integrity of the compressor system, particularly with respect to temperature and vibrations. Instrumentation improvements include new pressure transducers to observe higher pressures and mass flow rates and the implementation

  14. History of ultrahigh carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J.; Sherby, O.D.


    The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and processing is of interest in understanding the role of carbon content in the development of modern steels. Although sporadic examples of UHCS compositions are found in steels examined in the early part of this century, it was not until the mid-1970s that the modern study began. This study had its origin in the development of superplastic behavior in steels and the recognition that increasing the carbon content was of importance in developing that property. The compositions that were optimal for superplasticity involved the development of steels that contained higher carbon contents than conventional modern steels. It was discovered, however, that the room temperature properties of these compositions were of interest in their own right. Following this discovery, a period of intense work began on understanding their manufacture, processing, and properties for both superplastic forming and room temperature applications. The development of superplastic cast irons and iron carbides, as well as those of laminated composites containing UHCS, was an important part of this history.

  15. Compression and radiation of high-power short rf pulses. I. Energy accumulation in direct-flow waveguide compressors

    KAUST Repository

    Sirenko, Kostyantyn


    Proper design of efficient requires precise understanding of the physics pertinent to energy accumulation and exhaust processes in resonant waveguide cavities. In this paper, practically for the first time these highly non-monotonic transient processes are studied in detail using a rigorous time-domain approach. Additionally, influence of the geometrical design and excitation parameters on the compressor\\'s performance is quantified in detail.

  16. Modelling Steel Behaviour


    Anderberg, Yngve


    When modelling material mechanical behaviour, an analytical description is required of the relationship between stresses and strains. A computer oriented mechanical behaviour model for steel is described. The model is based on the fact that the deformation process at transient high temperature conditions can be desribed by three strain components which are separately found in different steady state tests. It is shown that a behaviour model based on steady state data satisfactorily predicts be...

  17. Effect of CuO nanolubricant on compressor characteristics and performance of LPG based refrigeration cycle: experimental investigation (United States)

    Kumar, Ravinder; Singh, Jagdev; Kundal, Pankaj


    Refrigeration, Ventilation and Air Conditioning system is the largest reason behind the increasing demand of energy consumption in the world and saving that energy through some innovative methods becomes a large issue for the researchers. Compressor is a primary component of the refrigeration cycle. The application of nanoparticles in refrigeration cycle overcomes the energy consumption issue by improving the compressor suction and discharge characteristics. In this paper, an experimental study is carried out to investigate the effect of copper oxide (CuO) nanoparticles on different parameters of the refrigeration cycle. CuO particles are appended with the system refrigerant through lubricating oil of the compressor. Further, the viscosity measurements and friction coefficient analysis of compressor lubricant for different fractions of nanoparticles has been investigated. The results showed that both the suction and discharge characteristics of the compressor were enhanced with the utilization of nanolubricant in LPG based refrigeration cycle. Nanoparticles additive in lubricant increases the viscosity which lead to a significant decrease in friction coefficient. The COP of the cycle was improved by 46%, as the energy consumption of the compressor was decreased by 7%.

  18. Japanese and American competition in the development of scroll compressors and its impact on the American air conditioning industry

    Energy Technology Data Exchange (ETDEWEB)

    Ushimaru, Kenji (Energy International, Inc., Bellevue, WA (USA))


    This report examines the technological development of scroll compressors and its impact on the air conditioning equipment industry. Scroll compressors, although considered to be the compressors of the future for energy-efficient residential heat pumps and possibly for many other applications, are difficult to manufacture on a volume-production base. The manufacturing process requires computer-aided, numerically controlled tools for high-precision fabrication of major parts. Japan implemented a global strategy for dominating the technological world market in the 1970s, and scroll compressor technology benefited from the advent of new-generation machine tools. As a result, if American manufacturers of scroll compressors purchase or are essentially forced to purchase numerically controlled tools from Japan in the future, they will then become dependent on their own competitors because the same Japanese conglomerates that make numerically controlled tools also make scroll compressors. This study illustrates the importance of the basic machine tool industry to the health of the US economy. Without a strong machine tool industry, it is difficult for American manufacturers to put innovations, whether patented or not, into production. As we experience transformation in the air conditioning and refrigeration market, it will be critical to establish a consistent national policy to provide healthy competition among producers, to promote innovation within the industry, to enhance assimilation of new technology, and to eliminate practices that are incompatible with these goals. 72 refs., 8 figs., 1 tab.

  19. Wootz Damascus steel blades

    Energy Technology Data Exchange (ETDEWEB)

    Verhoeven, J.D.; Gibson, E.D. [Ames Lab., IA (United States); Pendray, A.H. [ABS Master Bladesmith, Williston, FL (United States)


    Wootz Damascus steel blades contain surface patterns produced by bands of cementite particles which are generated in situ as the blades are forged from small ingots. A process for making these blades has recently been developed which involves making ingots in a gas-fired furnace followed by forging to blade shapes. This study presents a series of additional experiments which provide strong evidence that the mechanism responsible for the formation of the aligned cementite bands is similar to the mechanism that produces banded hypoeutectoid steels. That mechanism attributes the selective formation of ferrite bands to microsegregated alloying elements. The results of this study show that the cementite bands will form in ultraclean hypereutectoid steels (P and S levels <0.003 wt. %) by the addition of small amounts of carbide-forming elements V, Cr, and Ti at a combined level of <0.02 wt. %. The results present strong evidence that the cementite bands are formed by a selective coarsening of cementite particles during the thermal cycling of the forging process. The particle coarsening is induced to occur preferentially in the interdendritic regions of the alloys by the very small additions of the carbide-forming elements.

  20. Analysis on the stirling-type pulse tube refrigerator in consideration of dynamics of linear compressor (United States)

    Ko, Junseok; Jeong, Sangkwon


    This paper describes the performance analysis of Stirling-type pulse tube refrigerator (PTR) in conjunction with the dynamics of the accompanied linear compressor. The dynamic behavior of the piston in the linear compressor is directly influenced by the load condition of the PTR. In this paper, the dynamic equation of the piston is simultaneously solved with the thermo-hydraulic governing equations of the PTR using linear analysis model and the performance of the PTR is predicted with the accompanied thermal losses. The developed analysis code is verified with the experimental results. The effect of the inertance tube length which plays an important role in the PTR is also specifically investigated from the experimental and simulation results. It clearly shows the effect of the flow impedance of the inertance tube on the dynamic response of the piston as well as the cooling performance of the PTR.

  1. A Study on Contact Force between Wraps of Scroll Compressor for CO2 Refrigerant (United States)

    Hiwata, Akira; Sawai, Kiyoshi; Sakuda, Atsushi; Morimoto, Takashi; Fukuta, Mitsuhiro; Yanagisawa, Tadashi

    The scroll compressor has two leakage passes, which are the gap in an axial direction at the tip of the wrap and the gap in a radial direction between the wraps. Many attempts to reduce the leakage through those gaps have been actively researched and developed. In this study, we grasped the characteristics of the contact force between the wraps of a CO2 scroll compressor with the fixed orbiting radius by measuring the oil-film pressure at the main bearing. In addition, we developed the analytical method to simulate the contact force considering the effect on the formation of oil-film at the bearings and move constrain of the orbiting scroll. As a result, we found that (1) there is a fluctuation of the contact force at one revolution, (2) the contact force increases with rotational speed, (3) the contact force has little change for operating condition and (4) contact force increases with decreasing the wrap clearance.

  2. Experimental studies on twin PTCs driven by dual piston head linear compressor (United States)

    Gour, Abhay S.; Joy, Joewin; Sagar, Pankaj; Sudharshan, H.; Mallappa, A.; Karunanithi, R.; Jacob, S.


    An experimental study on pulse tube cryocooler is presented with a twin pulse tube configuration. The study is conducted with a dual piston head linear compressor design which is developed indigenously. The two identical pulse tube cryocoolers are operated by a single linear motor which generates 1800 out of phase dual pressure waves. The advantages of the configuration being the reduction in fabrication cost and the increased cooling power. The compressor is driven at a frequency of 48 Hz using indigenously developed PWM based power supply. The CFD study of pulse tube cryocooler is discussed along with the experimental cool down results. A detailed experimental and FEM based studies on the fabrication procedure of heat exchangers is conducted to ensure better heat transfer in the same.

  3. Development of a stochastic dynamical model for hermetic compressor's components with experimental investigation (United States)

    Fontanela, F.; Silva, O. M.; Lenzi, A.; Ritto, T. G.


    The analysis of household compressor's components is typically evaluated by using mathematical-mechanical models, and many decisions are taken based on simulations. However, such an investigation is usually performed in a deterministic framework, which cannot consider manufacturing variabilities and epistemic uncertainties. In this paper, a stochastic structural model that considers data and model uncertainties is developed for a discharge pipe connected to a hermetic compressor's shell. An experimental test rig is constructed to test each part separately, and an identification strategy is proposed to fit the stochastic model to experimental results. Finally, the impact of the uncertainties in each structural component on the dynamical responses of the whole system is investigated. It turns out that: (1) the proposed stochastic dynamical model presented very good results when compared to the experimental responses, and (2) uncertainties in the discharge pipe model play an important role in the coupled system dynamics.

  4. A thermal network model for induction motors of hermetic reciprocating compressors (United States)

    Dutra, T.; Deschamps, C. J.


    This paper describes a simulation model for small reciprocating compressors with emphasis on the electrical motor modelling. Heat transfer is solved through algebraic equations derived from lumped thermal energy balances applied to the compressor components. Thermal conductances between the motor components are characterized via a thermal network model. The single-phase induction motor is modelled via an equivalent circuit, allowing predictions for the motor performance and distributed losses. The predicted temperature distribution is used to evaluate the stator and rotor windings resistances. The thermal and electric models are solved in a coupled manner with a model for the compression cycle. Predictions of temperature distribution, motor efficiency, as well as isentropic and volumetric efficiencies, are compared with experimental data at different operating conditions. The model is then applied to analyse the motor temperature as a function of input voltage and stator wire diameter.

  5. Tip-Clearance Measurement in the First Stage of the Compressor of an Aircraft Engine. (United States)

    García, Iker; Przysowa, Radosław; Amorebieta, Josu; Zubia, Joseba


    In this article, we report the design of a reflective intensity-modulated optical fiber sensor for blade tip-clearance measurement, and the experimental results for the first stage of a compressor of an aircraft engine operating in real conditions. The tests were performed in a ground test cell, where the engine completed four cycles from idling state to takeoff and back to idling state. During these tests, the rotational speed of the compressor ranged between 7000 and 15,600 rpm. The main component of the sensor is a tetrafurcated bundle of optical fibers, with which the resulting precision of the experimental measurements was 12 µm for a measurement range from 2 to 4 mm. To get this precision the effect of temperature on the optoelectronic components of the sensor was compensated by calibrating the sensor in a climate chamber. A custom-designed MATLAB program was employed to simulate the behavior of the sensor prior to its manufacture.

  6. A New Approach to Designing the S-Shaped Annular Duct for Industrial Centrifugal Compressor

    Directory of Open Access Journals (Sweden)

    Ivan Yurko


    Full Text Available The authors propose an analytical method for designing the inlet annular duct for an industrial centrifugal compressor using high-order Bezier curves. Using the design of experiments (DOE theory, the three-level full factorial design was developed for determination of influence of the dimensionless geometric parameters on the output criteria. Numerical research was carried out for determination of pressure loss coefficients and velocity swirl angles using the software system ANSYS CFX. Optimal values of the slope for a wide range of geometric parameters, allowing minimizing losses in the duct, have been found. The study has used modern computational fluid dynamics techniques to develop a generalized technique for future development of efficient variable inlet guide vane systems. Recommendations for design of the s-shaped annular duct for industrial centrifugal compressor have been given.

  7. Transient flow in a compressor blade row for a periodic vibration motion (United States)

    Idres, Moumen; Labanie, Mohamed; Okasha, Mohamed


    The goal of this work is to conduct a transient compressor blade row flow simulation as part of blade flutter modeling. An integral step of blade flutter modeling is the calculation of the aerodynamic damping factor as a function of the possible vibration mode shapes. Using Fourier method, the number of blade passages required for transient flow analysis is kept to a minimum of two for all vibration modes. In this work, a compressor rotor blade row is considered. The vibration modes are obtained using ANSYS mechanical, then, unsteady flow is obtained for vibrating blades with a harmonic motion. Work of the flow on the blade is calculated and hence the aerodynamic damping is obtained.

  8. Linguistic Modeling of Pressure Signal in Compressor and Application in Aerodynamic Instability Prediction

    Directory of Open Access Journals (Sweden)

    Hanlin Sheng


    Full Text Available Using conditional fuzzy clustering, a linguistic model for static pressure signal of compressor outlet in aeroengine was established. The modeling process and the validation result demonstrated unique advances of linguistic modeling in the analysis of complex systems. The linguistic model was used to predict the pressure signal before the engine entered instability. The prediction result showed that the linguistic model could effectively recognize the sudden changes of pressure signal features. The detected change of signal might not necessarily be the commonly considered initial disturbance of compressor instability; however, the pattern recognition ability of linguistic model was still very attractive. At last, it pointed out that setting up a database containing experiment data and historical experience about engine aerodynamic instability and utilizing advanced intelligent computing technology in the database to develop knowledge discovery provide a new idea for the solution to the problem of aerodynamic instability in aeroengine.

  9. Performance of a Low Speed Axial Compressor Rotor Blade Row under Different Inlet Distortions

    Directory of Open Access Journals (Sweden)

    R. Taghavi Zenouz


    Full Text Available Responses of an axial compressor isolated rotor blade row to various inlet distortions have been investigated utilizing computational fluid dynamic technique. Distortions have been imposed by five screens of different geometries, but with the same blockage ratio. These screens were embedded upstream of the rotor blade row. Flow fields are simulated in detail for compressor design point and near stall conditions. Performance curves for distorted cases are extracted and compared to the undisturbed case. Flow simulations and consequent performance characteristics show that the worst cases belong to non-symmetric blockages, i.e., those of partial circumferential configurations. These cases produce the largest wakes which can disturb the flow, considerably. Superior performances correspond to the inner and outer continuous circumferential distortion screens. Since, they produce no significant disturbances to the main flow in comparison to the non-symmetric screens.

  10. Fracture Mechanisms in Steel Castings

    Directory of Open Access Journals (Sweden)

    Stradomski Z.


    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  11. Adaptive fuzzy PID control of hydraulic servo control system for large axial flow compressor (United States)

    Wang, Yannian; Wu, Peizhi; Liu, Chengtao


    To improve the stability of the large axial compressor, an efficient and special intelligent hydraulic servo control system is designed and implemented. The adaptive fuzzy PID control algorithm is used to control the position of the hydraulic servo cylinder steadily, which overcomes the drawback that the PID parameters should be adjusted based on the different applications. The simulation and the test results show that the system has a better dynamic property and a stable state performance.

  12. Degree of compression and energy efficiency of a capillary compressor of femtosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Konyashchenko, Aleksandr V; Kostryukov, P V; Losev, Leonid L; Tenyakov, S Yu


    A relation between the degree of pulse compression and energy efficiency is derived for femtosecond laser pulse compressors that utilise spectral broadening of pulses in a gas-filled capillary. We show that the degree of compression has a maximum at an energy efficiency from 15% to 30%. A 15-fold compression of a 290-fs pulse with an energy efficiency of 24% is demonstrated.

  13. Efficiency Improvement of Rotary Compressor by Improving the Discharge path through Simulation


    Bolloju, Siva Rama Krishna; Tiruveedhula, Vamsi; Munnangi, Naveen; Vaddadi, Koteswara Rao; M, Pratap Reddy


    To help raise consumer awareness on saving energy and create more energy efficient appliances, the government is upgrading the requirements of star rating of air conditioners. The enhanced star rating in air conditioners will significantly support the energy conservation and protect the environment by reducing greenhouse gas emissions in the fight against climate change. The increasing demand for star rated air-conditioners is compelling the compressor designers to develop & optimize more ene...

  14. Preliminary design of a mini-Brayton Compressor-Alternator-Turbine (CAT) (United States)


    The preliminary design of a mini-Brayton compressor-alternator-turbine system is discussed. The program design goals are listed. The optimum system characteristics over the entire range of power output were determined by performing a wide-range parametric study. The ability to develop the required components to the degree necessary within the limitations of present technology is evaluated. The sensitivity of the system to various individual design parameters was analyzed.

  15. An Experimental and Numerical Analysis of Refrigerant Flow Inside the Suction Muffler of Hermetic Reciprocating Compressor


    Sarioglu, Dr. Kemal; Ozdemir, Ahmet Refik; Oguz, Emre; KAYA, Atilla


    In this study, detailed temperature and pressure measurements were performed at the inlet, outlet and outer boundaries of the suction muffler of a hermetic reciprocating compressor. The measurements were conducted without effecting real phenomena. After experimental studies, detailed computational fluid dynamic analysis of the refrigerant flow (isobutane) in the suction muffler was performed. Experimental pressure and temperature values at the inlet, outlet and outer boundaries of the suction...

  16. The analysis of the flow with water injection in a centrifugal compressor stage using CFD simulation (United States)

    Michal, Tomášek; Richard, Matas; Tomáš, Syka


    This text deals with the principle of direct cooling of the pressure gas in a centrifugal compressor based on evaporation of the additional fluid phase in a control domain. A decrease of the gas temperature is reached by taking the heat, which is required for evaporation of the fluid phase. The influence of additional fluid phase on the parameters of the multiphase flow is compared with the ideal gas simulation in the defined domain and with the same boundary conditions.

  17. BRIEF COMMUNICATIONS: Pulse-periodic iodine photodissociation laser pumped with radiation from magnetoplasma compressors (United States)

    Kashnikov, G. N.; Orlov, V. K.; Panin, A. N.; Piskunov, A. K.; Reznikov, Vladimir A.


    A study was made of the characteristics of an iodine photodissociation laser pumped by radiation emitted from magnetoplasma compressors. A closed system for circulating the working gas C3F7I was employed in this laser. Pulse-periodic operation with an interval of 1 min between the pulses was achieved; the output energy was 110 J and the pulse duration was 30 μ sec.

  18. Numerical modeling of the radiating plasmadynamic discharges of an erosion-type magnetoplasma compressor (United States)

    Ardelian, N. V.; Kamrukov, A. S.; Kozlov, N. P.; Kosmachevskii, K. V.; Popov, Iu. P.

    The vacuum discharges of magnetoplasma compressors are investigated by numerical modeling for flow velocities of 30-70 km/s, compression ratios up to 300, and currents up to 5 x 10 to the 5th A. The model allows for two-dimensional MHD effects, characteristics of erosion plasma formation, and the emission and thermodynamic properties of the erosion plasma. The results obtained are in good agreement with experimental data.

  19. Experimental and numerical study of tip injection in a subsonic axial flow compressor

    Directory of Open Access Journals (Sweden)

    Wei WANG


    Full Text Available Parametric study of tip injection was implemented experimentally on a subsonic axial flow compressor to understand the underlying flow mechanisms of stability improvement of the compressor with discrete tip injection. Injector throat height varied from 2 to 6 times the height of rotor tip clearance, and circumferential coverage percentage ranged from 8.3% to 25% of the annulus. Static pressure fluctuations over the rotor tip were measured with fast-response pressure transducers. Whole-passage time-accurate simulations were also carried out to help us understand the flow details. The combinations of tip injection with traditional casing treatments were experimentally studied to generate an engineering-acceptable method of compressor stall control. The results indicate that the maximum stability improvement is achieved when injectors are choked despite their different sizes. The effect of circumferential coverage percentage on compressor stability depends on the value of injector throat height for un-choked injectors, and vice versa. Tip blockage in the blade passage is greatly reduced by the choked injectors, which is the primary reason for stability enhancement. The accomplishment of blockage diminishment is maintained in the circumferential direction with the unsteady effect of tip injection, which manifests as a hysteresis between the recovery of tip blockage and the recovery of tip leakage vortex. The unsteady effect is primarily responsible for the effectiveness of tip injection with a partial circumferential coverage. Tip injection cannot enhance the stability of the rotor with axial slots significantly, but it can improve the stability of the rotor with circumferential grooves further. The combined structure of tip injection with circumferential grooves is an alternative for engineering application.

  20. A baseline expert control system for marine gas turbine compressor surge


    Davitt, James A.


    Approved for public release; distribution is unlimited United States Navy gas turbine ships are in need of casualty control system updating to reduce demanding conditions on engineering watch standers, to increase equipment longevity, and reduce operating costs. This thesis presents a baseline computer-based expert system controller concept developed for the critical casualty control problem of gas turbine compressor surge. The controller design rests on the building-block components of re...

  1. Environmental protection of titanium alloys in centrifugal compressors at 500°C in saline atmosphere


    Béguin, Jean-Denis; Faure, Pierre; Adrian, Denise; Alexis, Joël; Petit, Jacques-Alain; Belaygue, Philippe; Fournier, Dominique


    International audience; The use of the titanium alloy Ti-6246 (Ti-6Al-2Sn-4Zr-6Mo, wt-%) for gas turbine compressors allows an increase in working temperature and stress level. Under severe service conditions, the material experiences combined high temperature and high mechanical stress and, in saline atmospheres, stress corrosion cracking (SCC) can occur, leading to catastrophic mechanical failure. The present study was performed to evaluate the potential of several surface treatments to pro...

  2. Experimental investigation of a counter-rotating compressor with boundary layer suction

    Directory of Open Access Journals (Sweden)

    Shi Lei


    Full Text Available This paper presents the aspirated modification of a dual-stage counter-rotating compressor which contains inlet guide vanes (IGVs, two counter-rotating rotors (R1, R2, and outlet guide vanes (OGVs. Uniform circular holes are circumferentially distributed over the rotors’ tips on the shroud casing which are designed to remove the low-energy fluid near the shroud casing. OGVs are hollow blades with two slots designed on the suction side which can better control the flow on the suction surface through boundary layer suction. Related works about the experiments have been carried out since June 2012 and the effect of flow suction on the performance of the compressor is investigated in detail. Characteristic lines at a 70% corrected rotating speed are tested and those with higher rotating speeds will be studied in the near future. Experimental results indicate that boundary layer suction can improve the compressor characteristics and the best suction methodology varies along the operating line. At the near stall condition, suction from the R2 tip region can obviously increase the efficiency and the total pressure ratio, as well as improve the flow capacity. Isentropic efficiency can be maximally increased by 4.24% with an increase of 1.94% in massflow under a suction flow of 160 m3/h. Suction at the R1 position with a suction rate below 0.35% in a high flow situation can make the performance of the compressor better than others. Around the peak efficiency point, boundary layer suction from the slots of OGVs is the best choice in improving the efficiency, but it causes a 0.1% loss in the total pressure ratio.


    Directory of Open Access Journals (Sweden)

    Wojciech GÓRA


    Full Text Available In this paper a control system of air compressors in a university laboratory is presented. The control system, which is built using the Astraada RCC972 and the GE 90-20 drivers, is an extension of the two states’ inputs and outputs of Astraada. To visualize the work stand, the PC computer class and the Proficy Machine Edition (ME View software were applied. Selected results from the tests of the built control system are presented.

  4. Synthesis of thermit noncorrodible steels


    Жигуц, Юрій Юрійович


    The present paper the basic solutions to the problem of obtaining cavitation-resistant steels examined the use of thermite steels, the benefits of combining thermite steels with metallotermic methods of getting is showed. The advantages of metallotermic synthesis methods include: autonomy of processes, independence of energy sources, simplicity of equipment, high-performance process and easy transition from experimental research to industrial production. The need to developed the technology o...

  5. Case Study regarding the test of the new screw compressor with high delivery pressure - 45 bara - on the test bench (with air

    Directory of Open Access Journals (Sweden)

    Valentin PETRESCU


    Full Text Available Screw compressors, which are part of positive displacement compressors, can find an increasing use in gas industry and beyond due to their advantages. Maximal parameters of these devices, done by Comoti under GHH-Rand license stop at a maximum flow of 3000 Nm3/hour and 26 bara discharge pressure. The needs of potential beneficiaries have imposed the necessity to design and manufacture a new family of screw compressors and oil injection able to develop a discharge pressure of 45 bara with flow rates up to 5000 Nm3/hour. This paper presents the design and experimental test phases – for the first screw compressor with discharge of pressure up to 45 bara – CU90 HP. Continue research and development have allowed to this type of screw-compressor – to find a market position, diversifying its size range in the last decade in a manner more explosive, if we refer to other types of compressors.

  6. Test Report #33: Compressor Calorimeter Test of R-410A Alternative: R-32/R-134a Mixture Using a Scroll Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sharma, Vishaldeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    This report investigates the tested performance of lower - GWP candidate refrigerant, 94.07 wt% R - 32 + 5.93 wt % R - 134 a mixture (hereafter referred to as R - 32/134a), as an alternative to baseline refrigerant R - 410 A using a 36,000 Btu/hr compressor calorimeter located at the Heat Exchanger Advanced Testing Facility at Oak Ridge National Laboratory . These tests were conducted during May and August 2013. R - 410A is a near - azeotropic blend of R - 32 and R - 125 with 0.5/0.5 mass fraction and has a GWP 100 of 2100. R - 32 and R - 134a are pure refrigerants and have GWP 100 of 716 and 1370 1, respectively. Based on the GWP 100 values of pure refrigerants and their mass fraction in the blend, GWP 100 of R - 32/134a, which is under development by National Refrigerant, is 755. This report compares various performance parameters, such as cooling capacity, compressor power, refrigerant mass flow rate, EER, isentropic efficiency and discharge temperature of the alternative refrigerant to that of R - 410 A.

  7. Influence of Lubricant Additives on Friction and Wear Characteristics of Compressor parts under the Alternative Refrigerant (United States)

    Yamaguchi, Hidehiro; Imai, Hachiro; Yamamoto, Tetsuya; Yamamoto, Tsutomu; Ueki, Yutaka; Takizawa, Kikuo; Fukushima, Kiyoshi

    From the standpoint of lubricative deficit under the alternative refrigerant/lubricants coexistence, the influence of additives on friction and wear characteristics for compressor parts have been investigated by the wear tester reappeared on friction condition similarly to actual compressor. It has been shown that an ester type base oil containing TCP (tricresyl phosphate) as an extreme pressure agents indicates satisfactory lubrication because of its EP effect. However owning to the deterioration of base oil caused by a cresol which is a reactant of TCP, a hydrolysis inhibitor must be necessary. The results indicates that a hydrolysis inhibitor added to POE is able to not only prevent the base oil from deteriorating but also feed the strength into oil films. On the other hands, in such a case that TCP concentration added in an alkylbenzen type base oil is excess or wear track temperature is higher, wear amounts of compressor parts are increased on account of corrosion wear. The reactivity of TCP depends on wear track temperature and its concentration. Consequently, it is possible that EP effect of TCP has been considered in terms of its concentration and temperature to be appropriated.

  8. Numerical Investigation of Flow Losses through Discharge Line of Household Type Refrigerator Compressors (United States)

    Yesilaydin, I.; Erbay, L. B.


    The technological developments, competition and energy policies are forcing the refrigeration market to increase the efficiency of their products as never before. The component that determines the performance and efficiency of the refrigeration system is the compressor, which is the major energy consumer in a compression refrigeration system. One of the essential elements of the total compressor efficiency is the discharge line flow efficiency that is subjected to this study. In this paper, the effects of design parameters on flow loses at discharge line of a hermetic reciprocating compressor were investigated with numerical flow analysis. At this study, three conceptual designs were modelled based on the discharge line design parameters such as line diameter, resonator volumes and line length. The pressure drop regions are determined by CFD analyses and they compared against the base model. Analyses are carried out by using commercial CFD software. Furthermore, the obtained numerical results were compared to experimental data and presented a good agreement in terms of pressure drop and discharge line flow efficiency.

  9. Condition classification of small reciprocating compressor for refrigerators using artificial neural networks and support vector machines (United States)

    Yang, Bo-Suk; Hwang, Won-Woo; Kim, Dong-Jo; Chit Tan, Andy


    The need to increase machine reliability and decrease production loss due to faulty products in highly automated line requires accurate and reliable fault classification technique. Wavelet transform and statistical method are used to extract salient features from raw noise and vibration signals. The wavelet transform decomposes the raw time-waveform signals into two respective parts in the time space and frequency domain. With wavelet transform prominent features can be obtained easily than from time-waveform analysis. This paper focuses on the development of an advanced signal classifier for small reciprocating refrigerator compressors using noise and vibration signals. Three classifiers, self-organising feature map, learning vector quantisation and support vector machine (SVM) are applied in training and testing for feature extraction and the classification accuracies of the techniques are compared to determine the optimum fault classifier. The classification technique selected for detecting faulty reciprocating refrigerator compressors involves artificial neural networks and SVMs. The results confirm that the classification technique can differentiate faulty compressors from healthy ones and with high flexibility and reliability.

  10. Kaybob Revisited: What We Have Learned about Compressor Stability from Self-Excited Whirling

    Directory of Open Access Journals (Sweden)

    Edgar J. Gunter


    Full Text Available The Kaybob compressor failure of 1971 was an excellent historic example of rotordynamic instability and the design factors that affect this phenomenon. In the case of Kaybob, the use of poorly designed bearings produced unstable whirling in both the low and high pressure compressors. This required over five months of vibration troubleshooting and redesign along with over 100 million modern U.S. dollars in total costs and lost revenue. In this paper, the history of the Kaybob compressor failure is discussed in detail including a discussion of the ineffective bearing designs that were considered. Modern bearing and rotordynamic analysis tools are then employed to study both designs that were considered along with new designs for the bearings that could have ultimately restored stability to the machine. These designs include four-pad, load-between-pad bearings and squeeze film dampers with a central groove. Simple relationships based on the physics of the system are also used to show how the bearings could be tuned to produce optimum bearing stiffness and damping of the rotor vibration, producing insights which can inform the designers as they perform more comprehensive analyses of these systems.

  11. Semi-supervised vibration-based classification and condition monitoring of compressors (United States)

    Potočnik, Primož; Govekar, Edvard


    Semi-supervised vibration-based classification and condition monitoring of the reciprocating compressors installed in refrigeration appliances is proposed in this paper. The method addresses the problem of industrial condition monitoring where prior class definitions are often not available or difficult to obtain from local experts. The proposed method combines feature extraction, principal component analysis, and statistical analysis for the extraction of initial class representatives, and compares the capability of various classification methods, including discriminant analysis (DA), neural networks (NN), support vector machines (SVM), and extreme learning machines (ELM). The use of the method is demonstrated on a case study which was based on industrially acquired vibration measurements of reciprocating compressors during the production of refrigeration appliances. The paper presents a comparative qualitative analysis of the applied classifiers, confirming the good performance of several nonlinear classifiers. If the model parameters are properly selected, then very good classification performance can be obtained from NN trained by Bayesian regularization, SVM and ELM classifiers. The method can be effectively applied for the industrial condition monitoring of compressors.

  12. Near-Field Characterization of Methane Emission Variability from a Compressor Station Using a Model Aircraft. (United States)

    Nathan, Brian J; Golston, Levi M; O'Brien, Anthony S; Ross, Kevin; Harrison, William A; Tao, Lei; Lary, David J; Johnson, Derek R; Covington, April N; Clark, Nigel N; Zondlo, Mark A


    A model aircraft equipped with a custom laser-based, open-path methane sensor was deployed around a natural gas compressor station to quantify the methane leak rate and its variability at a compressor station in the Barnett Shale. The open-path, laser-based sensor provides fast (10 Hz) and precise (0.1 ppmv) measurements of methane in a compact package while the remote control aircraft provides nimble and safe operation around a local source. Emission rates were measured from 22 flights over a one-week period. Mean emission rates of 14 ± 8 g CH4 s(-1) (7.4 ± 4.2 g CH4 s(-1) median) from the station were observed or approximately 0.02% of the station throughput. Significant variability in emission rates (0.3-73 g CH4 s(-1) range) was observed on time scales of hours to days, and plumes showed high spatial variability in the horizontal and vertical dimensions. Given the high spatiotemporal variability of emissions, individual measurements taken over short durations and from ground-based platforms should be used with caution when examining compressor station emissions. More generally, our results demonstrate the unique advantages and challenges of platforms like small unmanned aerial vehicles for quantifying local emission sources to the atmosphere.

  13. [Which compressor should be used to deliver pentamidine aerosols with the Respirgard II?]. (United States)

    Landman, R; Faurisson, F; Becquemin, M H; Bouchikhi, A; Girard, P M


    Prophylaxis against pneumonia due to Pneumocystis carinii is most often carried out using pentamidine administered as an aerosol. For reasons both of comfort and cost this technique should be developed at home or at least in an extra-hospital environment. Using the Respirgard II as the nebuliser of reference this requires a compressor. We have assessed four different compressors and compared these to pressurised oxygen used in a hospital environment. During the course of nebulisation with a pentamidine aerosol two physical factors may coincide to limit their efficacy. First the deposition of some of the particles on the walls of the apparatus and secondly the production of a particle size which is incompatible with alveolar deposition. This study showed that according to the source of compressed air: 1) the fraction of the pentamidine solution found in an aerosol at the mouthpiece varies from 29 to 62%; 2) the fraction of the aerosol whose particle size is suitable for alveolar deposition (1 to 3 microns) varies from 35 to 48%. The product of these two fractions enables an assessment of the efficiency of each apparatus: 14 to 24% of the pentamidine solution may be deposited at the alveolar level. In addition to this efficiency the duration of the session (from 25 to 50 minutes) for each machine should be taken into consideration when considering the choice of the compressor to be coupled with the Respirgard II in order to improve the comfort and therefore the compliance to the treatment.

  14. Evaluation of noise propagation characteristics of compressors in tehran oil refinery center and presenting control methods. (United States)

    Golmohammadi, Rostam; Monazzam, Mohammad Reza; Nourollahi, Maryam; Nezafat, Ali; Momen Bellah Fard, Samaneh


    The adverse effects of noise are well known and noise problems due to industrialization of communities are increasing over the time. Oil industries due to the process and nature of production; contain many noise sources such as compressors, turbines, and pumps, which cause excessive noise exposure. The objective of this study was to evaluate the noise characteristics of compressors in Tehran Oil Refinery and study on visible control measures.  To get to the appropriate control method, procedures such as basic theories, measuring sound parameters, frequency analysis, related diagrams and noise propagation schemes due to the measurement results, equivalent noise exposure level (L(eq(8h))) and exposure noise dose and  technical specification of compressors are considered in this paper. Considering field and analytical re-sults, module enclosure with particular specifications (like absorbent layer, specific wall, window and door design etc.) is predicted to be the best control method.  Calculation results of multiple layer density of the enclosure (W = 16.5 kg/m(2)) and needed density for the dominant frequency of the source (W = 12 kg/m(2)) demonstrated that the designed enclosure satisfies the goal. RESULTS of designing sandwich layers' module demonstrated that install-ing the designed enclosure causes 20 dB(A) reduction in total sound pres-sure level of the source's dominant frequency.

  15. Single-shot lifetime-based PSP and TSP measurements on turbocharger compressor blades (United States)

    Peng, Di; Jiao, Lingrui; Yu, Yuelong; Liu, Yingzheng; Oshio, Tetsuya; Kawakubo, Tomoki; Yakushiji, Akimitsu


    Fast-responding pressure-sensitive paint (Fast PSP) and temperature-sensitive paint (TSP) measurements were conducted on two turbocharger compressors using a single-shot lifetime-based technique. The fast PSP and TSP were applied on separate blades of one compressor, and both paints were excited by a pulsed 532 nm Nd:YAG laser. The luminescent decay signals following the laser pulse were recorded by a CCD camera in a double-exposure mode. Instantaneous pressure and temperature fields on compressor blades were obtained simultaneously, for rotation speeds up to 150,000 rpm. The variations in pressure and temperature fields with rotation speed, flow rate and runtime were clearly visualized, showing the advantage of high spatial resolution. Severe image blurring problems and significant temperature-induced errors in the PSP results were found at high rotation speeds. The first issue was addressed by incorporating a deconvolution-based deblurring algorithm to recover the clear image from the blurred image using the combination of luminescent lifetime and rotation speed. The second issue was resolved by applying a pixel-by-pixel temperature correction based on the TSP results. The current technique has shown great capabilities in flow diagnostics of turbomachinery and can serve as a powerful tool for CFD validations and design optimizations.

  16. Detection of Rotor Forced Response Vibrations Using Stationary Pressure Transducers in a Multistage Axial Compressor

    Directory of Open Access Journals (Sweden)

    William L. Murray


    Full Text Available Blade row interactions in turbomachinery can lead to blade vibrations and even high cycle fatigue. Forced response conditions occur when a forcing function (such as impingement of stator wakes occurs at a frequency that matches the natural frequency of a blade. The objective of this research is to develop the data processing techniques needed to detect rotor blade vibration in a forced response condition from stationary fast-response pressure transducers to allow for detection of rotor vibration from transient data and lead to techniques for vibration monitoring in gas turbines. This paper marks the first time in the open literature that engine-order resonant response of an embedded bladed disk in a 3-stage intermediate-speed axial compressor was detected using stationary pressure transducers. Experiments were performed in a stage axial research compressor focusing on the embedded rotor of blisk construction. Fourier waterfall graphs from a laser tip timing system were used to detect the vibrations after applying signal processing methods to uncover these pressure waves associated with blade vibration. Individual blade response was investigated using cross covariance to compare blade passage pressure signatures through resonance. Both methods agree with NSMS data that provide a measure of the exact compressor speeds at which individual blades enter resonance.

  17. Usage and validation of a fluid structure interaction methodology for the study of different suction valve parameters of a hermetic reciprocating compressor


    LANG, W.; R Almbauer; D Jajcevic


    The dynamics of the flatter valves inside a hermetic reciprocating compressor used in household appliances is the most important factor concerning the gas dynamic behaviour of such a compressor. Hence for a good valve design and for a reliable simulation of the compressor the ability to predict the movement of the valves is indispensable. The present paper describes a methodology which allows the prediction of the valve dynamics. For the validation of the methodology the simulation results of...

  18. Numerical investigation of variable inlet guide vanes with trailing-edge dual slots to decrease the aerodynamic load on centrifugal compressor impeller


    Jianchi Xin; Xiaofang Wang; Haitao Liu


    In engineering practice, most centrifugal compressors use variable inlet guide vanes which can provide pre-whirl and control volume flow rates. As the impeller of a centrifugal compressor passes through the wakes created from the guide vanes, the aerodynamic parameters change significantly. The concept of adding dual slots at the trailing-edge of the guide vanes is proposed for reducing the aerodynamic load on the compressor impeller blades. In this article, the steady and unsteady performanc...

  19. A Study of the Effects of Gas Well Compressor Noise on Breeding Bird Populations of the Rattlesnake Canyon Habitat Management Area, San Juan County, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    LaGory, K.E.; Chang, Young-Soo; Chun, K.C.; Reeves, T.; Liebich, R.; Smith, K.


    This report, conducted from May through July 2000, addressed the potential effect of compressor noise on breeding birds in gas-production areas administered by the FFO, specifically in the Rattlesnake Canyon Habitat Management Area northeast of Farmington, New Mexico. The study was designed to quantify and characterize noise output from these compressors and to determine if compressor noise affected bird populations in adjacent habitat during the breeding season.

  20. Comparison of Turbulence Models in Simulation of Flow in Small-Size Centrifugal Compressor

    Directory of Open Access Journals (Sweden)

    B. B. Novickii


    Full Text Available The aim of the work is the choice of turbulence model for the closure of the Reynoldsaveraged Navier-Stokes equations for calculation of the characteristics of small-size centrifugal compressor. To this were built three-dimensional sectors (as the compressor axisymmetric blade impeller and the diffuser of the centrifugal compressor on the basis of which they were created two grid models. The dimension of the grid model for the calculation models of turbulence komega and SST was 1.4 million. Elements and the dimensionless parameter y + does not exceed 2. turbulence model family k-epsilon model grid was also 1.4 million. Elements, and the dimensionless parameter y + was greater than 20, which corresponds to recommended values. The next part of the work was the task of boundary conditions required for the correct ca lculation. When the impeller inlet pawned pressure working fluid and the total temperature at the outlet and the gas flow rate through the stage. On the side faces sectors pawned boundary cond ition «Periodic», allowing everything except the wheel, but only axisymmetric part, which significantly reduces the required computational time and resources. Accounting clearance in addition to the meridional geometry construction additionally taken into account boundary condition «Counter Rotating Wall», which allows you to leave the domain in the rotating disc fixed coa ting.The next step was to analyze the results of these calculations, which showed that the turbulence model k-epsilon and RNG does not show the velocity vectors in the boundary layer, and "pushes" the flow from the blade using wall functions. At the core of the flow turbulence model k-omega shown for the undisturbed flow, which is not typical for the compressor working on predpompazhnom mode. For viscous gas diffuser vane for turbulence models SST, k-omega, RNG k-epsilon and has a similar character.The paper compares the characteristics of pressure centrifugal compressor

  1. Steel designers' handbook

    CERN Document Server

    Gorenc, Branko; Tinyou, Ron


    The Revised 7th Edition of Steel Designers' Handbook is an invaluable tool for all practising structural, civil and mechanical engineers as well as engineering students at university and TAFE in Australia and New Zealand. It has been prepared in response to changes in the design Standard AS 4100, the structural Design Actions Standards, AS /ANZ 1170, other processing Standards such as welding and coatings, updated research as well as feedback from users. This edition is based on Australian Standard (AS) 4100: 1998 and subsequent amendments. The worked numerical examples in the book have been e

  2. Typhoon of Steel


    Hamamoto, Gena


    Typhoon of Steel is a short community-based documentary film that explores the lives of two Okinawan American Kibei Nisei who served in the U.S. military as linguists in the Battle of Okinawa during World War II. While Japanese Americans on the West Coast were incarcerated in camps, these men risked their lives to prove their loyalty to America. Born in the U.S. and raised in Okinawa, their cultural and linguistic skills were a tactical asset to the military. But emotions ran high as they ...

  3. Mechanics in Steels through Microscopy

    NARCIS (Netherlands)

    Zandbergen, H.W.; Tirumalasetty, G.K.

    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP

  4. corrosion inhibitor for carbon steels

    African Journals Online (AJOL)

    potentiodynamic polarisation techniques. It was found that. CNSL reduces the extent of the electrochemical processes taking place on carbon steel undergoing corrosion. The corrosion rate of the carbon steel was reduced by over 92 % when only 300 ppm of CNSL was applied. This indicates that. CNSL is a potential ...

  5. Mechanics in Steels through Microscopy

    NARCIS (Netherlands)

    Tirumalasetty, G.K.


    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP

  6. Steels from materials science to structural engineering

    CERN Document Server

    Sha, Wei


    Steels and computer-based modelling are fast growing fields in materials science as well as structural engineering, demonstrated by the large amount of recent literature. Steels: From Materials Science to Structural Engineering combines steels research and model development, including the application of modelling techniques in steels.  The latest research includes structural engineering modelling, and novel, prototype alloy steels such as heat-resistant steel, nitride-strengthened ferritic/martensitic steel and low nickel maraging steel.  Researchers studying steels will find the topics vital to their work.  Materials experts will be able to learn about steels used in structural engineering as well as modelling and apply this increasingly important technique in their steel materials research and development. 

  7. Numerical analysis of flow in a centrifugal compressor with circumferential grooves: influence of groove location and number on flow instability (United States)

    Chen, X.; Qin, G.; Ai, Z.; Ji, Y.


    As an effective and economic method for flow range enhancement, circumferential groove casing treatment (CGCT) is widely used to increase the stall margin of compressors. Different from traditional grooved casing treatments, in which the grooves are always located over the rotor in both axial and radial compressors, one or several circumferential grooves are located along the shroud side of the diffuser passage in this paper. Numerical investigations were conducted to predict the performance of a low flow rate centrifugal compressor with CGCT in diffuser. Computational fluid dynamics (CFD) analysis is performed under stage environment in order to find the optimum location of the circumferential casing groove in consideration of stall margin enhancement and efficiency gain at design point, and the impact of groove number to the effect of this grooved casing treatment configuration in enhancing the stall margin of the compressor stage is studied. The results indicate that the centrifugal compressor with circumferential groove in vaned diffuser can obtain obvious improvement in the stall margin with sacrificing design efficiency a little. Efforts were made to study blade level flow mechanisms to determine how the CGCT impacts the compressor’s stall margin (SM) and performance. The flow structures in the passage, the tip gap, and the grooves as well as their mutual interactions were plotted and analysed.

  8. Experimental Investigation of an Automobile Air-Conditioning System using Integrated Brushless Direct Current Motor Rotary Compressor

    Directory of Open Access Journals (Sweden)

    Sukri M.F.


    Full Text Available The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP. Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X. In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X, the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T5 (35ºC, or at T5 = 30ºC for constant X (4.96.

  9. Modeling and control of a proton exchange membrane fuel cell with the air compressor according to requested electrical current

    Directory of Open Access Journals (Sweden)

    Malekbala Mohammad Rahim


    Full Text Available The aim of this paper is to design and investigate the dynamic behavior of a PEM fuel cell system. Dynamic analysis of a PEM fuel cell system has been done in Matlab\\Simulink software according to electrical current that has been applied from hybrid system. In addition, dynamical fuel cell system has been explained according to oriented control that is started from air injection compressor model. Also hydrogen valve actuator has been controlled according to the compressor model. The results of the fuel cell dynamic model as well as the applied compressor model are fully validated based on the available results in the open literature. Finally, the effects of several operating parameters of the fuel cell system such as anode and cathode pressures, cell voltage, compressor voltage, compressor mass flow rate variation with respect to inlet pressure ratio, net and stack powers on the dynamic behavior of the hybrid system are investigated. The results show that the model can predict the dynamic behavior of the fuel cell system accurately and it can be used directly for any control purposes.

  10. Effects of bending-torsional duct-induced swirl distortion on aerodynamic performance of a centrifugal compressor (United States)

    Hou, Hongjuan; Wang, Leilei; Wang, Rui; Yang, Yanzhao


    A turbocharger compressor working in commercial vehicles, especially in some passenger cars, often works together with some pipes with complicated geometry as an air intake system, due to limit of available space in internal combustion engine compartments. These pipes may generate various distortions of physical parameters of the air at the inlet of the compressor and therefore the compressor aerodynamic performance deteriorates. Sometimes, the turbocharging engine fails to work at some operation points. This paper investigates the effects of various swirl distortions induced by different bending-torsional intake ducts on the aerodynamic performance of a turbocharger compressor by both 3D numerical simulations and experimental measurements. It was found that at the outlet of the pipes the different inlet ducts can generate different swirl distortions, twin vortices and bulk-like vortices with different rotating directions. Among them, the bulk-like vortices not only affect seriously the pressure distribution in the impeller domain, but also significantly deteriorate the compressor performance, especially at high flow rate region. And the rotating direction of the bulk-like vortices is also closely associated with the efficiency penalty. Besides the efficiency, the transient flow rate through a single impeller channel, or the asymmetric mass flow crossing the whole impeller, can be influenced by two disturbances. One is from the upstream bending-torsional ducts; other one is from the downstream volute.

  11. Investigation of a centrifugal compressor and study of the area ratio and TIP clearance effects on performance (United States)

    Nili-Ahmadabadi, Mahdi; Hajilouy-Benisi, Ali; Durali, Mohammad; Ghadak, Farhad


    In this research, the centrifugal compressor of a turbocharger is investigated experimentally and numerically. Performance characteristics of the compressor were obtained experimentally by measurements of rotor speed and flow parameters at the inlet and outlet of the compressor. Three dimensional flow field in the impeller and diffuser was analyzed numerically using a full Navier-Stokes program with SST turbulence model. The performance characteristics of the compressor were obtained numerically, which were then compared with the experimental results. The comparison shows good agreement. Furthermore, the effect of area ratio and tip clearance on the performance parameters and flow field was studied numerically. The impeller area ratio was changed by cutting the impeller exit axial width from an initial value of 4.1 mm to a final value of 5.1 mm, resulting in an area ratio from 0.792 to 0.965. For the rotor with exit axial width of 4.6 mm, performance was investigated for tip clearance of 0.0, 0.5 and 1.0 mm. Results of this simulation at design point showed that the compressor pressure ratio peaked at an area ratio of 0.792 while the efficiency peaked at a higher value of area ratio of 0.878. Also the increment of the tip clearance from 0 to 1 mm resulted in 20 percent efficiency decrease.

  12. Wet gas compression. Experimental investigation of the aerodynamics within a centrifugal compressor exposed to wet gas

    Energy Technology Data Exchange (ETDEWEB)

    Gruener, Trond Gammelsaeter


    The demand for more efficient oil and gas production requires improved technology to increase production rates and enhance profitable operation. The centrifugal compressor is the key elements in the compression system. Preliminary studies of wet gas compressor concepts have demonstrated the benefits of wet gas boosting. An open-loop test facility was designed for single-stage wet gas compressor testing. Experimental investigators have been performed to reveal the impact of liquid on the aerodynamics of centrifugal compressor. The investigation consisted of two test campaigns with different impeller/diffuser configurations. Atmospheric air and water were used as experimental fluids. The two configurations showed a different pressure ratio characteristics when liquid as present. The results from test campaign A demonstrated a pronounced pressure ratio decrease at high flow and a minor pressure ration increase pressure ratio with reducing gas mass fraction (GMF). The deviation in pressure ratio characteristic for the two test campaigns was attributed to the volute operating characteristic. Both impeller/diffuser configurations demonstrated a reduction in maximum volume flow with decreasing GMF. The impeller pressure ratio was related to the diffuser and/or the volute performance). Air and water are preferable experimental fluids for safety reasons and because a less extensive facility design is required. An evaluation of the air/water tests versus hydrocarbon tests was performed in order to reveal whether the results were representative. Air/water tests at atmospheric conditions reproduced the general performance trend of hydrocarbon wet gas compressor tests with an analogous impeller at high pressures. Aerodynamic instability limits the operating range because of feasible severe damage of the compressor and adverse influence on the performance. It is essential to establish the surge margin at different operating conditions. A delayed instability inception was

  13. 49 CFR 192.55 - Steel pipe. (United States)


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for use...

  14. Improving the toughness of ultrahigh strength steel

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Koji [Univ. of California, Berkeley, CA (United States)


    The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors.

  15. Effects of airfoil-probe tubes on the flow field of a compressor cascade (United States)

    Ma, Hongwei; Jin, Chao; Zhao, Lianpeng; Ma, Rong


    To explore the effects of airfoil-probe tubes and its installment position on the flow field of the compressor cascade, and find out the mechanism that how the airfoil-probes affect the aerodynamic characteristics of the compressor cascade, this paper performed both numerical and experimental works on the same compressor cascade. The experiment mainly focused on the cases of low Mach number (Ma = 0.1), and cases with different Mach numbers (0.1, 0.3, 0.7) and different incidence angles (-5, 0, 5) are investigated by the numerical method. The case without the airfoil-probe tube was referenced as the baseline, and other three cases with the airfoil-probe tubes installed in different chordwise positions (30%, 50%, 70% of the chord length) were studied. The diameter of the airfoil-probe tube is 3mm, which is configured as 300% amplification of some particular airfoil-probe according to the geometrical similarity principle. The results show that the airfoil-probe tubes have a negative influence on the flow capacity of the cascade at all investigation points. The separations and the large scale streamwise vortices that induced by the airfoil-probe tube on the pressure side cause most the losses at the high Mach number. The influence of the airfoil-probe tube on the flow field in the vicinity of the pressure side surface is local separation at the low Mach number. The airfoil-probe tubes also have a clearly effect on the leakage flow. It decreases the mass flow of the leakage flow and weakens the intensity of the leakage vortex, but enlarges the influence area. The total pressure loss of the case that the tube is installed at the half chordwise position is generally lower than other cases especially at the high Mach number, it can even decrease the losses compared with the basic case.

  16. Comparison between the environmental damages of two axial air compressors manufactured by the firm Fini Compressori (United States)

    Neri, Paolo; Bernardi, Giuseppe; Buttol, Patrizia; Naldi, Giovanni; Saric, Miroslav; Tani, Giovanni


    This study was performed jointly by ENEA (Italian National Agency for New Technologies, Energy and Environment), Bologna and Florence Universities and the firm FINI COMPRESSORI. A comparison is carried out between the environmental damages of two models (MK10 and MK94) of air axial compressors manufactured by FINI COMPRESSORI, with a volume of intaken air of 226 l/min, a power of 1.8 kW and a maximum pressure of 10 bar. The comparison is obtained by using LCA calculated by SimaPro 3.1 code and two methods: Eco-indicator 95 and a new method obtained by adding to the Eco-indicator 95 method other damage categories such as some raw material depletion, solid and energy. The system boundaries include raw material extraction and the end of life of the components and some special tools for manufacturing such as dies, moulds and shells. All metallic materials have the recycling as waste scenario. For LCA study we have considered the three components crankshaft, crankcase and valve plate for both the models, the air cooling conveyor for the MK94 and the surplus of consumed energy for the MK10. The conveyor decreases the temperature of air and therefore increases the compressor efficiency and reduces the electrical energy consumption during the use. From the LCA results, we can conclude that the introduction of the conveyor reduces the damage of MK10 model of 114.07 mPt and that the other modifications of the design increase the damage of MK10 model of 11 mPt. The damage of air compressor can be diminished by reusing crankshaft and crankcase. A design modification of the blades of the ventilator is proposed to avoid the conveyor.

  17. Methods of making bainitic steel materials

    Energy Technology Data Exchange (ETDEWEB)

    Bakas, Michael Paul; Chu, Henry Shiu-Hung; Zagula, Thomas Andrew; Langhorst, Benjamin Robert


    Methods of making bainitic steels may involve austenitizing a quantity of steel by exposing the quantity of steel to a first temperature. A composition of the quantity of steel may be configured to impede formation of non-bainite ferrite, pearlite, and Widmanstatten ferrite. The quantity of steel may be heat-treated to form bainite by exposing the quantity of steel to a second, lower temperature. The second, lower temperature may be stabilized by exposing the quantity of steel to the second, lower temperature in the presence of a thermal ballast.

  18. Stahlschüssel key to steel

    CERN Document Server

    Wegst, W S


    The Key to Steel (Stahlschlüssel/Stahlschluessel) cross reference book will help you to decode / decipher steel designations and find equivalent materials worldwide. The 2016 edition includes more than 70,000 standard designations and trade names from approximately 300 steelmakers and suppliers. Presentation is trilingual: English, French, and German. Materials covered include structural steels, tool steels, valve steels, high temperature steels and alloys, stainless and heat-resisting steels, and more. Standards and designations from 25 countries are cross-referenced.

  19. Constructing the universal characteristic of a compressor based on the results of thermal tests of gas turbine units and using it to calculate variable operating modes (United States)

    Ol'Khovskii, G. G.; Trushechkin, V. P.; Chadovskaya, I. I.


    A procedure for constructing the universal characteristic of a compressor at different positions of its inlet guide vane using experimentally obtained characteristics of the compressor and turbine, and a computer program for simulating variable operating modes of a gas turbine unit are described. Results from a comparison between calculated data and data obtained from tests of similar types of gas turbines units are presented.

  20. Performance Improvement of R 410A Room Air Conditioner by Vapor Injection Refrigeration Cycle Using Scroll Compressor (United States)

    Nakamura, Hiroo; Daisaka, Hisashi; Yokoyama, Hidenori; Nonaka, Masayuki; Saito, Kiyoshi

    The vapor injection refrigeration cycle using the scroll compressor driven by inverter was investigated to improve the performance of room air conditioner with R 410A. One injection hole was bored on a fixed scroll plate, and through this hole the vapor refrigeration is injected into two compression rooms of a scroll compressor at different time. Then the pressure change of the compression room and the performance of vapor injection refrigeration cycle are calculated. And the performance of the room air conditioner using vapor injection refrigeration cycle was measured. As the result, the cooling/heating compressor input was decreased to 7.4/3.2 % at capacity 4.0/5.9 kW, and the heating capacity at outdoor temperature -15 °C was increased to 11.9 %.

  1. Control and performance improvements of a pulse compressor in use for testing accelerating structures at high power (United States)

    Woolley, Benjamin; Syratchev, Igor; Dexter, Amos


    New developments relating to compact X-band, SLED-I type pulse compressors being developed at CERN for testing high gradient structures are described. Pulse compressors of interest take rf pulses from one or more high power klystrons with duration typically >1.5 μ s and deliver up to 5 times the input power for a shorter duration operation with low level rf (LLRF) control have been developed. Input drive amplitude and phase for each pulse is evolved with a control algorithm from the pulse compressor output for previous pulses. The goal is to deliver precise amplitude for pulses to test stands and precise amplitude and phase for pulses to accelerator systems. Control algorithms have been developed and validated experimentally.

  2. Modelling fracture in ferritic steel

    CERN Document Server

    Smith, G


    Results from mathematical models and computer simulations of fracture in polycrystalline steels are presented for a range of temperatures. The proportions of intergranular and intragranular failure predicted are compared with experimental results for brittle fracture, ductile fracture and in the transition region. Interactive software to create two-dimensional polycrystalline models, which allow a range of physical to be varied independently, is described. The results include those for model materials chosen to match steels used by the power generation industry. The models simulate segregation and cavitation effects in steel and fracture of weldments and their associated heat-affected zones.

  3. Cold-formed steel design

    CERN Document Server

    Yu, Wei-Wen


    The definitive text in the field, thoroughly updated and expanded Hailed by professionals around the world as the definitive text on the subject, Cold-Formed Steel Design is an indispensable resource for all who design for and work with cold-formed steel. No other book provides such exhaustive coverage of both the theory and practice of cold-formed steel construction. Updated and expanded to reflect all the important developments that have occurred in the field over the past decade, this Fourth Edition of the classic text provides you with more of the detailed, up-to-the-minute techni

  4. Steel fiber replacement of mild steel in prestressed concrete beams (United States)


    In traditional prestressed concrete beams, longitudinal prestressed tendons serve to resist bending moment and : transverse mild steel bars (or stirrups) are used to carry shear forces. However, traditional prestressed concrete I-beams : exhibit earl...

  5. High-strength, low-alloy steels. (United States)

    Rashid, M S


    High-strength, low-alloy (HSLA) steels have nearly the same composition as plain carbon steels. However, they are up to twice as strong and their greater load-bearing capacity allows engineering use in lighter sections. Their high strength is derived from a combination of grain refinement; precipitation strengthening due to minor additions of vanadium, niobium, or titanium; and modifications of manufacturing processes, such as controlled rolling and controlled cooling of otherwise essentially plain carbon steel. HSLA steels are less formable than lower strength steels, but dualphase steels, which evolved from HSLA steels, have ferrite-martensite microstructures and better formability than HSLA steels of similar strength. This improved formability has substantially increased the utilization potential of high-strength steels in the manufacture of complex components. This article reviews the development of HSLA and dual-phase steels and discusses the effects of variations in microstructure and chemistry on their mechanical properties.

  6. 2169 steel waveform experiments.

    Energy Technology Data Exchange (ETDEWEB)

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.


    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mmthick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  7. Results of Investigative Tests of Gas Turbine Engine Compressor Blades Obtained by Electrochemical Machining (United States)

    Kozhina, T. D.; Kurochkin, A. V.


    The paper highlights results of the investigative tests of GTE compressor Ti-alloy blades obtained by the method of electrochemical machining with oscillating tool-electrodes, carried out in order to define the optimal parameters of the ECM process providing attainment of specified blade quality parameters given in the design documentation, while providing maximal performance. The new technological methods suggested based on the results of the tests; in particular application of vibrating tool-electrodes and employment of locating elements made of high-strength materials, significantly extend the capabilities of this method.

  8. Restoration of the wear-resistant coatings on a GTE compressor airfoil shroud platform (United States)

    Abraimov, N. V.; Geikin, V. A.; Chekalova, E. A.; Lukina, V. V.


    The deposition of a VT20 alloy onto the airfoil shroud platform of a compressor in an argon atmosphere and the composition, the structure, and the properties of a restored wear-resistant VK-25M coating are studied. The coating deposited onto the built-up material is found to contain (%) 3-4 C, 72-74 W, and 23-24 Co. This coating does not undergo cracking when a diamond pyramid is indented at a load of 50 kg or a diamond cone is indented at a load of 100 kg at a layer thickness of 0.15, 0.25, and 0.38 mm.

  9. Radiative gasdynamic processes in imploding discharges in a plasmodynamic magnetoplasma compressor (United States)

    Kamrukov, A. S.; Kozlov, N. P.; Protasov, Iu. S.; Chuvashev, S. N.


    Radiative gasdynamic processes in collapsing radiating plasmodynamic discharges in magnetoplasma compressors are simulated numerically and the results are compargd with available experimental data. The nonequilibrium ionic composition, the electron-ion temperature stratification, and the vaporization and influx of vaporized material from the transparent channel walls into the plasma in the implosion zone are all found to be important. The interaction between radiation and vaporization appreciably alters the time dependence of the light output relative to the pumping pulse and enhances the light-emitting efficiency of the discharge.

  10. Life time extension of quasi-stationary plasma flow from Magnetoplasma Compressor (United States)

    Dojčinović, I. P.; Kuraica, M. M.; Astashynski, V. M.; Purić, J.


    Time extension of quasi-stationary plasma flows from Magnetoplasma Compressor (MPC) operating in nitrogen at 5 mbar pressure has been obtained and discussed. A condenser bank of 1200 μF charged up to 2.7, 3.2 and 4 kV has been used as energy supply and was realized as an adequate delay line using properly chosen inductivity of the coils inserted among the capacitors and the resistance of the connecting conductor line through an ignitron to MPC electrode system. It gives a possibility to enlarge several times the life times of the investigated compression plama flows from MPC under the same other experimental conditions.

  11. Compression zone of a magnetoplasma compressor as a source of extreme UV radiation (United States)

    Garkusha, I. E.; Chebotarev, V. V.; Solyakov, D. G.; Petrov, Yu. V.; Ladygina, M. S.; Marchenko, A. K.; Staltsov, V. V.; Yelisyeyev, D. V.


    Results from experimental studies of extreme UV (EUV) radiation from the compression zone of a magnetoplasma compressor (MPC) operating with xenon are presented. Two MPC operating modes that differ in the method of xenon injection into the discharge were studied. It is shown that EUV radiation in the wavelength range of 5-80 nm is emitted from the compression zone. In the MPC operating mode with local xenon injection directly into the compression zone surrounded by helium plasma, the radiation power reaches it peak value of 16-18 kW in the wavelength range of 12.2-15.8 nm.

  12. Compression zone of a magnetoplasma compressor as a source of extreme UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I. E.; Chebotarev, V. V.; Solyakov, D. G.; Petrov, Yu. V.; Ladygina, M. S.; Marchenko, A. K.; Staltsov, V. V.; Yelisyeyev, D. V. [National Academy of Sciences of Ukraine, Institute of Plasma Physics, National Science Center ' Kharkiv Institute of Physics and Technology,' (Ukraine)


    Results from experimental studies of extreme UV (EUV) radiation from the compression zone of a magnetoplasma compressor (MPC) operating with xenon are presented. Two MPC operating modes that differ in the method of xenon injection into the discharge were studied. It is shown that EUV radiation in the wavelength range of 5-80 nm is emitted from the compression zone. In the MPC operating mode with local xenon injection directly into the compression zone surrounded by helium plasma, the radiation power reaches it peak value of 16-18 kW in the wavelength range of 12.2-15.8 nm.

  13. Magnetogasdynamic effects during the interaction between a gas and erosion plasma flows in a magnetoplasma compressor (United States)

    Ardelian, N. V.; Kamrukov, A. S.; Kozlov, N. P.; Kosmachevskii, K. V.; Popov, Iu. P.

    The physics of the interaction between a gas and erosion plasma flows is examined with reference to the results of a numerical experiment. It is shown that the interaction of a radially inhomogeneous flow with a deformable gas obstacle leads to the formation of a conical shock MHD-wave, with a local increase in pressure, temperature, and magnetic field at its front. Behind the shock wave, the plasma flow turns parallel to the contact boundary, with a noticeable increase in the radial velocity component. This leads to a significant increase in flow cumulation efficiency in comparison with a vacuum magnetoplasma compressor.

  14. High-tip-speed fiber composite compressor blades: Vibration and strength analysis (United States)

    Chamis, C. C.; Lynch, J. E.


    An analytical procedure is described which couples composite mechanics computer codes with NASTRAN. This procedure was used to perform a detailed analysis of a high-tip-speed fiber composite compressor fan blade. The results indicate that the various vibration modes of this blade are highly coupled. Mechanical load ply stresses are well below the corresponding room temperature strengths. Lamination residual stresses are likely to cause transply cracks and interply delamination. Transply cracks and relaxation of root fixity decrease the vibrational frequencies whereas centrifugal stiffening increases them. Comparisons of results for various parameters are presented in tabular and graphical form.

  15. Impact of Optics on CSR-Related Emittance Growth in Bunch Compressor Chicanes

    CERN Document Server

    Limberg, Torsten


    The dependence of emittance growth due to Coherent Synchrotron Radiation (CSR) in bunch compressor chicanes on optics has been noticed and empirically studied in the past. We revisit the subject, suggesting a model to explain slice emittance growth dependence on chicane optics. A simplified model to calculate projected emittance growth when it is mainly caused by transverse slice centroid offsets is presented. It is then used to find optimal compensation of centroid kicks in the single chicanes of a two-stage compression system by adjusting the phase advance of the transport in between and the ration of the compression factors.

  16. Research on Flow Characteristics of Supercritical CO2 Axial Compressor Blades by CFD Analysis (United States)

    Takagi, Kazuhisa; Muto, Yasushi; Ishizuka, Takao; Kikura, Hiroshige; Aritomi, Masanori

    A supercritical CO2 gas turbine of 20MPa is suitable to couple with the Na-cooled fast reactor since Na - CO2 reaction is mild at the outlet temperature of 800K, the cycle thermal efficiency is relatively high and the size of CO2 gas turbine is very compact. In this gas turbine cycle, a compressor operates near the critical point. The property of CO2 and then the behavior of compressible flow near the critical point changes very sharply. So far, such a behavior is not examined sufficiently. Then, it is important to clarify compressible flow near the critical point. In this paper, an aerodynamic design of the axial supercritical CO2 compressor for this system has been carried out based on the existing aerodynamic design method of Cohen1). The cycle design point was selected to achieve the maximum cycle thermal efficiency of 43.8%. For this point, the compressor design conditions were determined. They are a mass flow rate of 2035kg/s, an inlet temperature of 308K, an inlet static pressure of 8.26MPa, an outlet static pressure of 20.6MPa and a rotational speed of 3600rpm. The mean radius was constant through axial direction. The design point was determined so as to keep the diffusion factor and blade stress within the allowable limits. Number of stages and an expected adiabatic efficiency was 14 and 87%, respectively. CFD analyses by FLUENT have been done for this compressor blade. The blade model consists of one set of a guide vane, a rotor blade and a stator blade. The analyses were conducted under the assumption both of the real gas properties and also of the modified ideal gas properties. Using the real gas properties, analysis was conducted for the 14th blade, whose condition is remote from the critical point and the possibility of divergence is very small. Then, the analyses were conducted for the blade whose conditions are nearer to the critical point. Gradually, divergence of calculation was encountered. Convergence was relatively easy for the modified ideal

  17. Beam dynamics performances and applications of a low-energy electron-beam magnetic bunch compressor

    Energy Technology Data Exchange (ETDEWEB)

    Prokop, C. R.; Piot, P.; Carlsten, B. E.; Church, M.


    Many front-end applications of electron linear accelerators rely on the production of temporally compressed bunches. The shortening of electron bunches is often realized with magnetic bunch compressors located in high-energy sections of accelerators. Magnetic compression is subject to collective effects including space charge and self interaction via coherent synchrotron radiation. In this paper we explore the application of magnetic compression to low-energy (~40MeV), high-charge (nC) electron bunches with low normalized transverse emittances (<5@mm).

  18. End-wall and profile losses in a low-speed axial flow compressor rotor (United States)

    Lakshminarayana, B.; Sitaram, N.; Zhang, J.


    The blade-to-blade variation of relative stagnation pressure losses in the tip region inside the rotor of a single-stage, axial-flow compressor, is presented and interpreted in this paper. The losses are measured at two flow coefficients (one at the design point and the other at the near peak pressure rise point) to discern the effect of blade loading on the end-wall losses. The tip clearance losses are found to increase with an increase in the pressure rise coefficient. The losses away from the tip region and near the hub regions are measured downstream. The losses are integrated and interpreted in this paper.

  19. Some peculiarities of corrosion of wheel steel


    Alexander SHRAMKO; Alfred KOZLOWSKY; Elena BELAJA; Yuriy PROIDAK; Sofia PINCHUK; Svetlana GUBENKO


    Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosi...

  20. Review on Cold-Formed Steel Connections


    Lee, Yeong Huei; Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian


    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connection...

  1. Numerical investigation of variable inlet guide vanes with trailing-edge dual slots to decrease the aerodynamic load on centrifugal compressor impeller

    Directory of Open Access Journals (Sweden)

    Jianchi Xin


    Full Text Available In engineering practice, most centrifugal compressors use variable inlet guide vanes which can provide pre-whirl and control volume flow rates. As the impeller of a centrifugal compressor passes through the wakes created from the guide vanes, the aerodynamic parameters change significantly. The concept of adding dual slots at the trailing-edge of the guide vanes is proposed for reducing the aerodynamic load on the compressor impeller blades. In this article, the steady and unsteady performances of the new guide vanes are analysed under two compressor operating conditions (winter and design conditions. The results show that the average amplitude of the impeller passing frequency at the leading edge has a 13% decrease under the winter condition, especially at the middle and root parts. Moreover, the dual slots structure has no effect on the overall compressor performance.

  2. Operational efficiency of oil-flooded carbon dioxide screw refrigerating compressor as dependent on the supplied oil temperature (United States)

    Vasiliev, V. K.; Chernov, G. I.; Sadvakasov, D. Kh.; Panutich, A. A.


    The article presents the results of a theoretical study concerning the temperature influence of the oil supplied into the screw oil-flooded compressor on its efficiency under frequency regulation. The results of the research have shown that if the frequency regime of the compressor is changed by varying the oil proportion and the degree of its heating before supplying into the working cavity within certain limits, the new operating point will have the same or the largest value of the effective efficiency at a given new frequency.

  3. Early Jet Engines and the Transition from Centrifugal to Axial Compressors: A Case Study in Technological Change (United States)


    edition of his work appeared. In 1938, Eastman N. Jacobs and Eugene Wasielewski of the NACA began designing an axial-flow compressor on the basis of...development) proceeded slowly. In the case of NACA’s eight-stage compressor, Jacobs and Wasielewski designed it in 1938, the NACA built and tested it in 1941...36-38. In the late 1930’s Kantrowitz was involved in the design of a supersonic wind tunnel. 18 Seymour M. Bogdonoff and Harriet E. Bogdonoff, "Blade

  4. Development of a kilojoule channel for Nd-glass laser systems with a 70-ns pulse SBS compressor (United States)

    Sirazetdinov, Vladmir S.; Alekseev, V. N.; Charukhchev, A. V.; Kotilev, V. N.; Liber, V. I.; Serebryakov, Victor A.


    An optical scheme for a kJ channel of a neodymium glass laser system with SBS-compressor for a 70 ns pulse has been described. The use of a pump pulse of long duration - 70 ns - makes it possible to operate a near-steady SBS mode in compressed gasses. An experimental study of the SBS oscillator-compressor stage with pump focusing and a two- pass pattern has been carried out and a 70 ns, 8 J pump pulse has been compressed down to 1 ns.

  5. Modern motor and control technology for higher economic efficiency of compressors; Modernste Motoren- und Steuerungstechnik steigern Wirtschaftlichkeit von Kompressoren

    Energy Technology Data Exchange (ETDEWEB)

    Stengel, S. [Siemens AG, Erlangen (Germany). Automatisierungs- und Antriebstechnik; Lorenz, G. [Siemens AG, Fuerth (Germany). Automatisierungs- und Antriebstechnik


    Kaeser Kompressoren GmbH (Kasten) is one of the world's leaders in compressor construction. A new control and communication system for screw compressors on the basis of a compact PC and with energy-saving motors by Siemens and other suppliers sets new standards in compressed-air production. [German] Die Firma Kaeser Kompressoren GmbH (Kasten) zaehlt zu den weltweit fuehrenden Herstellern im Kompressorenbau. Mit einem neuen Steuerungs- und Kommunikationssystem fuer Schraubenkompressoren auf Basis eines PC-Kompaktrechners und mit Energiesparmotoren von Siemens und anderen Lieferanten setzt das Unternehmen erneut Massstaebe fuer die Drucklufterzeugung. (orig.)


    Directory of Open Access Journals (Sweden)

    L.G. Volyanskaya


    Full Text Available  The article considers the research results of D-27 gas turbine engine thrust-economical characteristics change due to of axial compressor flow path optimization. The applied procedure of optimization takes into account a difference in the shapes of axial compressor stage blades at rest and design mode, redistribution of kinetic energy losses along the blade height. The estimation of parameters of a gas flow in the stage flow path is made by the solution of Navier-Stokes equation complete set.

  7. Reciprocating compressors - simulation of their performance characteristics in a condensing unit; Kolbenverdichter - Simulation des Leistungsverhaltens beim Einsatz in einem Verfluessigungssatz

    Energy Technology Data Exchange (ETDEWEB)

    Ciconkov, R. [Univ. St. Kiril and Metodij, Masinski Fakultet, Skopje (Macedonia (The Former Yugoslav Republic of)); Hilligweg, A. [Georg-Simon-Ohm-Fachhochschule Nuernberg, Fachbereich Maschinenbau und Versorgungstechnik (Germany)


    In manufacturers' catalogues the refrigeration capacity and power input of a compressor are given depending on the evaporating and condensing temperatures of the refrigerant. In practical use these data have not to be absolutely correct because of the compressor's interaction with other components which show distinct influences. (orig.) [German] In Herstellerkatalogen sind die Leistungsdaten eines Verdichters wie Kaelteleistung oder Antriebsleistung abhaengig von Verdampfungs- und Verfluessigungstemperatur aufgefuehrt. Im praktischen Einsatz muessen diese Leistungsdaten nicht unbedingt zutreffen. Grund dafuer ist die Wechselwirkung mit den anderen Komponenten, die bestimmte eigene Einfluesse ausueben. (orig.)

  8. A one kPa centrifugal cold compressor for the 1.8 K helium refrigeration system of LHC

    CERN Document Server

    Saji, N; Yoshinaga, S; Itoh, K; Nogaku, T; Bézaguet, Alain-Arthur; Casas-Cubillos, J; Lebrun, P; Tavian, L


    CERN placed an order for a cold compressor prototype (CCP) with IHI for the LHC project. The CCP is supported by the oil-free magnetic bearings, driven by an induction motor. The compressor has the characteristics of high efficiency and wide operation range, thanks to the optimum design for the impeller and diffuser. The result of the performance tests at CERN showed that static heat in-leaks could be controlled at approx. 7.3 W, and an adiabatic efficiency is 75at a nominal flow of 18 g's with suction temperature of 4.4 K and suction pressure of 1 kPa. (4 refs).

  9. Stainless steel reinforcement as a replacement for epoxy coated steel in bridge decks : final report. (United States)


    The corrosion resistance of 2304 stainless steel reinforcement and stainless steel clad reinforcement was compared to conventional and epoxy-coated reinforcement (ECR). 2304 stainless steel was tested in both the as-received condition (dark mottled f...

  10. Steels for cryogenic power engineering

    Energy Technology Data Exchange (ETDEWEB)

    Ermakov, B.S.; Nikolaich A.Y.; Oparin, V.A.


    The authors investigated steels containing 0.9% C and 30% Mnwhich were additionally alloyed with 2, 4, 6, 8, 10, and 11% Al. Phase analysis on a diffractometer established that steels containing up to 10% Al have a single-phase austenitic structure and do not undergo any transformations whatsoever in plastic deformation and when cooled to 4 K. The magnetic permeability in an external magnetic field with intensity 620 kA/m and the mechanical properties of the investigated steels are presented in a table. These properties improve when their aluminum content increases to 10%; further alloying with aluminum causes some impairment of the plastic and ductile properties which is connected with the formation of alpha-phase in the structure of the steels.

  11. Phosphate Surface Treatments on Steel. (United States)


  12. A Tale of Wootz Steel

    Indian Academy of Sciences (India)

    /fulltext/reso/011/06/0067-0077. Keywords. Wootz steel; Damascus swords; Cyril Stanley Smith. Author Affiliations. S Ranganathan1 Sharada Srinivasan1. School of Humanities National Institute of Advanced Studies Bangalore 560 012, India ...

  13. Atmospheric corrosion of mild steel


    Morcillo, M.; de la Fuente, D.; Díaz, I.; Cano, H.


    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morphology of steel c...


    Directory of Open Access Journals (Sweden)

    Debanshu Bhattacharya


    Full Text Available Two major drivers for the use of newer steels in the automotive industry are fuel efficiency and increased safety performance. Fuel efficiency is mainly a function of weight of steel parts, which in turn, is controlled by gauge and design. Safety is determined by the energy absorbing capacity of the steel used to make the part. All of these factors are incentives for the U.S. automakers to use both Highly Formable and Advanced High Strength Steels (AHSS to replace the conventional steels used to manufacture automotive parts in the past. AHSS is a general term used to describe various families of steels. The most common AHSS is the dual-phase steel that consists of a ferrite-martensite microstructure. These steels are characterized by high strength, good ductility, low tensile to yield strength ratio and high bake hardenability. Another class of AHSS is the complex-phase or multi-phase steel which has a complex microstructure consisting of various phase constituents and a high yield to tensile strength ratio. Transformation Induced Plasticity (TRIP steels is another class of AHSS steels finding interest among the U.S. automakers. These steels consist of a ferrite-bainite microstructure with significant amount of retained austenite phase and show the highest combination of strength and elongation, so far, among the AHSS in use. High level of energy absorbing capacity combined with a sustained level of high n value up to the limit of uniform elongation as well as high bake hardenability make these steels particularly attractive for safety critical parts and parts needing complex forming. A relatively new class of AHSS is the Quenching and Partitioning (Q&P steels. These steels seem to offer higher ductility than the dual-phase steels of similar strengths or similar ductility as the TRIP steels at higher strengths. Finally, martensitic steels with very high strengths are also in use for certain parts. The most recent initiative in the area of AHSS

  15. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings. (United States)


    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The repairs...

  16. Investigation on Dynamic Behavior of Linear Compressor in Stirling-Type Pulse Tube Refrigerator (United States)

    Ko, Junseok; Jeong, Sangkwon; Kim, Youngkwon


    This paper describes the experimental study of the dynamic behavior of a linear compressor in a Stirling-type pulse tube refrigerator (PTR). The dynamic behavior of the piston is closely coupled with the hydraulic force of gas and, therefore, directly influenced by the specific load condition of the pulse tube refrigerator. In the experiment, the frequency response of the pressure at each component, the cooling performance and the piston displacement are measured while an alternate current with fixed magnitude is supplied to the linear motor. The linear compressor in this study was originally designed for a Stirling cryocooler and its maximum input power is approximately 200 W. The pulse tube refrigerator is configured as an in-line type and an inertance tube is incorporated as the phase control device in the pulse tube refrigerator. The pressure difference between both ends of the piston imposes additional stiffness and the PV power in the compression space can be considered a damping effect in the vibration system of the piston. From the experimental results, the effect of the gas force on the dynamic behavior of the piston is discussed. The dynamic relation among the input current, the displacement of the piston, the pulsating pressure and the cooling performance is also studied.

  17. A high-order model of rotating stall in axial compressors with inlet distortion

    Directory of Open Access Journals (Sweden)

    Peng LIN


    Full Text Available In this paper, a high-order distortion model is proposed for analyzing the rotating stall inception process induced by inlet distortion in axial compressors. A distortion-generating screen in the compressor inlet is considered. By assuming a quadratic function for the local flow total pressure-drop, the existing Mansoux model is extended to include the effects of static inlet distortion, and a new high-order distortion model is derived. To illustrate the effectiveness of the distortion model, numerical simulations are performed on an eighteenth-order model. It is demonstrated that long length-scale disturbances emerge out of the distorted background flow, and further induce the onset of rotating stall in advance. In addition, the circumferential non-uniform distribution and time evolution of the axial flow are also shown to be consistent with the existing features. It is thus shown that the high-order distortion model is capable of describing the transient behavior of stall inception and will contribute further to stall detection under inlet distortion.

  18. Benefits of compressor inlet air cooling for gas turbine cogeneration plants

    Energy Technology Data Exchange (ETDEWEB)

    De Lucia, M.; Lanfranchi, C. [Univ. di Firenze (Italy). Dept. di Energetica; Boggio, V. [CRIT S.r.l., Prato (Italy)


    Compressor inlet air cooling is an effective method for enhancing the performance of gas turbine plants. This paper presents a comparative analysis of different solutions for cooling the compressor inlet air for the LM6000 gas turbine in a cogeneration plant operated in base load. Absorption and evaporative cooling systems are considered and their performance and economic benefits compared for the dry low-NO{sub x} LM6000 version. Reference is made to two sites in Northern and Southern Italy, whose climate data series for modeling the variations in ambient temperature during the single day were used to account for the effects of climate in the simulation. The results confirmed the advantages of inlet air cooling systems. In particular, evaporative cooling proved to be cost effective, though capable of supplying only moderate cooling, while absorption systems have a higher cost but are also more versatile and powerful in base-load operation. An integration of the two systems proved to be able to give both maximum performance enhancement and net economic benefit.

  19. Reduction of the suction losses through reed valves in hermetic reciprocating compressors using a magnet coil (United States)

    Hopfgartner, J.; Posch, S.; Zuber, B.; Almbauer, R.; Krischan, K.; Stangl, S.


    Reed valves are widely used in hermetic reciprocating compressors and are responsible for a large part of the thermodynamic losses. Especially, the suction valve, which is opened nearly during the whole suction stroke, has a big potential for improvement. Usually, suction valves are opened only by vacuum created by the moving piston and should be closed before the compression stroke starts to avoid a reversed mass-flow through the valve. Therefore, the valves are prestressed, which results on the other hand in a higher flow resistance. In this work, a suction valve is investigated, which is not closed by the preload of the valve but by an electromagnetic coil located in the suction muffler neck. Shortly before the piston reaches its bottom dead centre, voltage is applied to the coil and a magnetic force is generated which pulls the valve shut. Thereby, the flow resistance through the valve can be reduced by changing the preload on the reed valve because it is no longer needed to close the valve. The investigation of this adapted valve and the electromagnetic coil is firstly done by numerical simulations including fluid structure interactions of the reed valves of a reciprocating compressor and secondly by experiments made on a calorimeter test bench.

  20. Study on flow field in capacity regulating actuator for reciprocating compressor (United States)

    Cao, J. L.; Hong, W. R.; Li, Y.; He, Z. K.


    The rated capacity of reciprocating compressor tends to be higher than the level needed, so the capacity regulation needs to be implemented to save unnecessary energy waste. Among the methods for reciprocating compressor capacity regulation, holding the suction valves open in partial stroke is a widely used method for its economy, full-range and easy-using characters. The capacity regulation system based on a hydraulic distributor has been successfully applied in industrial process. Hydraulic distributor is the core component of the complete set of stepless capacity regulation system. Continuous high-pressure hydraulic oil provided by hydraulic unit is converted into a pressure impulse wave with a controllable periodic time and pressure acting time when it flows through the hydraulic distributor, which is used to realize the suction valves regulation when it is in the compression stroke. Although the equipment is successfully used in industry fields, the fluid mechanics design of hydraulic distributor is still empirical as its complexity of the fluid field in inner circulation space. For better and more rational distributor design, the flow field in inner zones needs to be better analysed and studied. The manuscript concerned the subjects of path lines, pressure and velocity distribution in hydraulic distributor's flow channels using the CFD software FLUENT. The article explored the flow field characteristics and the flow performance with 5.0 MPa outlet pressure. In the end, a systematic conclusion would be given to guide the actor design.