Miniature Centrifugal Compressor

Science.gov (United States)

Sixsmith, Herbert

1989-01-01

Miniature turbocompressor designed for reliability and long life. Cryogenic system includes compressor, turboexpander, and heat exchanger provides 5 W of refrigeration at 70 K from 150 W input power. Design speed of machine 510,000 rpm. Compressor has gas-lubricated journal bearings and magnetic thrust bearing. When compressor runs no bearing contact and no wear.

Fluidos, bombas e instalaciones hidráulicas

OpenAIRE

Heras Jiménez, Salvador Augusto de las

2011-01-01

A la portada: Universitat Politècnica de Catalunya. Barcelonatech Descripció del recurs: 2 de maig de 2012 Esta obra describe los principios fundamentales que rigen el funcionamiento de las bombas y las instalaciones hidráulicas más usuales, sus características operativas y los criterios de diseño y selección. El contenido del libro se estructura en tres grupos básicos. Los dos primeros temas tratan de la mecánica de los fluidos y sus propiedades: los principios y las leyes de conser...

Centrifugal Compressor Surge Controlled

Science.gov (United States)

Skoch, Gary J.

2003-01-01

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

The Compressor Recycle System

OpenAIRE

Barstad, Bjørn Ove

2010-01-01

The compressor recycle system is the main focus of this thesis. When the mass flow through a compressor becomes too low, the compressor can plunge into surge. Surge is a term that is used for axisymmetric oscillation through a compressor and is highly unwanted. The recycle system feeds compressed gas back to the intake when the mass flow becomes too low, and thereby act as a safety system.A mathematical model of the recycle system is extended and simulated in SIMULINK. The mathematical model ...

Experimental investigation of a forced response condition in a multistage compressor

Science.gov (United States)

Murray, William Louis, III

The objective of this research is twofold. Firstly, the design, development, and construction of a test facility for a Honeywell APU-style centrifugal compressor was implemented, as well as the design and construction of an inlet flow experiment. Secondly, the aeromechanical response of an embedded stage in the Purdue 3-Stage axial research compressor was analyzed through a suite of different measurement techniques in the fulfillment of the end of the GUIde IV Consortium contract. The purpose of the first phase of Honeywell work was to comprehensively measure the flow field of an APU-style centrifugal compressor inlet through the use of Laser Doppler Velocimetry (LDV). A portion of a Honeywell supplied inlet was modified to provide optical access to the elbow, and a gas ejector system was designed and constructed to provide the same suction to the inlet that it would see during operation with the compressor. A performance and health monitoring electronics system was designed and purchased to support the testing of the Honeywell inlet ejector system and eventually it will be used for testing with a centrifugal compressor. Additionally, a secondary air and oil system has been designed and is currently being constructed in the test cell in preparation for the arrival of the Honeywell compressor this summer. An embedded rotor stage in the Purdue 3-stage compressor, with a Campbell diagram crossing of the 1T vibratory mode was analyzed with a suite of measurement systems. In addition to steady state compressor performance measurements, other types of measurements were used to characterize the aerodynamic forcing function for this forced response condition including: NSMS, high-frequency pressure transducers mounted in the casing and in a downstream stator, and cross-film thermal anemometry. Rotor geometry was measured by Aerodyne using an in-situ laser scanning technique. Vibrometry testing was performed at WPAFB to characterize safe operating speeds for stator

Comportamiento de la corrosión de diferentes aleaciones de titanio y tantalio en contacto con fluidos fisiológicos

OpenAIRE

Dueñas Santacruz, Ernesto Diego

2013-01-01

Programa de doctorado: Tecnología industrial El objetivo de la tesis es el estudio del comportamiento de diferentes aleaciones de titanio y tantalio en contacto con fluidos fisiológicos. En concreto, se trata de tres aleaciones con un contenido de un cinco, un quince y un veinticinco por ciento de tantalio. En cuanto al fluido fisiológico, se trata de una disolución Ringer.

Eficacia del extracto fluido de Vimang® en el tratamiento de pacientes con alveolitis

Directory of Open Access Journals (Sweden)

Yolanda Del Toro Gámez

2014-09-01

Full Text Available Se realizó un ensayo clínico de fase III en 118 pacientes con alveolitis, atendidos en la consulta estomatológica del Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba, para evaluar la eficacia del extracto fluido de Vimang® en el tratamiento de ellos. La muestra se dividió en 2 grupos (experimental y control, distribuidos aleatoriamente; los integrantes del primero, tratados con el mencionado extracto; y los del segundo, con Alvogyl. Los resultados del estudio fueron validados mediante el estadígrafo de Ji al cuadrado. Se concluye que el extracto fluido de Vimang® fue eficaz para eliminar la alveolitis en menor tiempo y sin reacciones adversas, por lo cual se recomendó generalizar su uso

Cooled spool piston compressor

Science.gov (United States)

Morris, Brian G. (Inventor)

1993-01-01

A hydraulically powered gas compressor receives low pressure gas and outputs a high pressure gas. The housing of the compressor defines a cylinder with a center chamber having a cross-sectional area less than the cross-sectional area of a left end chamber and a right end chamber, and a spool-type piston assembly is movable within the cylinder and includes a left end closure, a right end closure, and a center body that are in sealing engagement with the respective cylinder walls as the piston reciprocates. First and second annual compression chambers are provided between the piston enclosures and center housing portion of the compressor, thereby minimizing the spacing between the core gas and a cooled surface of the compressor. Restricted flow passageways are provided in the piston closure members and a path is provided in the central body of the piston assembly, such that hydraulic fluid flows through the piston assembly to cool the piston assembly during its operation. The compressor of the present invention may be easily adapted for a particular application, and is capable of generating high gas pressures while maintaining both the compressed gas and the compressor components within acceptable temperature limits.

Centrifugal Compressor Aeroelastic Analysis Code

Science.gov (United States)

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

2002-01-01

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

Compressor performance aerodynamics for the user

CERN Document Server

Gresh, Theodore

2001-01-01

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

Compressors selection and sizing

CERN Document Server

Brown, Royce N

2005-01-01

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

Empirical Design Considerations for Industrial Centrifugal Compressors

Directory of Open Access Journals (Sweden)

Cheng Xu

2012-01-01

Full Text Available Computational Fluid Dynamics (CFD has been extensively used in centrifugal compressor design. CFD provides further optimisation opportunities for the compressor design rather than designing the centrifugal compressor. The experience-based design process still plays an important role for new compressor developments. The wide variety of design subjects represents a very complex design world for centrifugal compressor designers. Therefore, some basic information for centrifugal design is still very important. The impeller is the key part of the centrifugal stage. Designing a highly efficiency impeller with a wide operation range can ensure overall stage design success. This paper provides some empirical information for designing industrial centrifugal compressors with a focus on the impeller. A ported shroud compressor basic design guideline is also discussed for improving the compressor range.

Oil-Free Compressor

Science.gov (United States)

Fitzjerrell, D. G.; Belver, T. L.; Moore, H. E.

1986-01-01

Compressor pistons moved by eccentric shaft need no lubricants. Compressor has shaft, middle section is eccentric in relation to end sections. Driven by brushless dc motor, shaft turns inner races of set of four cam bearings. Outer cam-bearing races in turn actuate four pistons spaced equally apart, around and along shaft. Each outer bearing race held in position by pressure exerted on it by piston. Because no frictional motion between piston and outer bearing race, lubricant between them unnecessary. Cam bearings themselves contain potted internal lubricant. Originally proposed for use in space, new compressor for refrigerators or freezers does not depend on pool of oil for lubricating its pistons. Operated in any orientation.

A review of linear compressors for refrigeration

OpenAIRE

Liang, Kun

2017-01-01

Linear compressor has no crank mechanism compared with conventional reciprocating compressor. This allows higher efficiency, oil-free operation, lower cost and smaller size when linear compressors are used for vapour compression refrigeration (VCR) system. Typically, a linear compressor consists of a linear motor (connected to a piston) and suspension springs, operated at resonant frequency. This paper presents a review of linear compressors for refrigeration system. Different designs and mod...

Meridional Considerations of the Centrifugal Compressor Development

Directory of Open Access Journals (Sweden)

C. Xu

2012-01-01

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.

Flow Range of Centrifugal Compressor Being Extended

Science.gov (United States)

Skoch, Gary J.

2001-01-01

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

Dispositivo para la medición automática del volumen de un fluido que corre por un conducto y el procedimiento para su medición y su posterior vaciado autónomo en función de la cantidad de fluido acumulado

OpenAIRE

Apalkov, Andrey; Fernández Saavedra, Roemi E.; Armada, Manuel; Otero-Rodríguez, Manuel Ángel

2012-01-01

Dispositivo para la medición del volumen de un fluido que corre por un conducto y su posterior vaciado autónomo compuesto por un receptor de líquido (1) y un sensor capacitivo (7) y que se caracteriza porque el receptor de líquido (1) tiene en su interior un elemento central móvil (12) con un obturador (13) para controlar el vaciado del líquido. El procedimiento para la medición y vaciado se caracteriza porque se mide el volumen de fluido Vi en el receptor ...

Algorithm for Controlling a Centrifugal Compressor

Science.gov (United States)

Benedict, Scott M.

2004-01-01

An algorithm has been developed for controlling a centrifugal compressor that serves as the prime mover in a heatpump system. Experimental studies have shown that the operating conditions for maximum compressor efficiency are close to the boundary beyond which surge occurs. Compressor surge is a destructive condition in which there are instantaneous reversals of flow associated with a high outlet-to-inlet pressure differential. For a given cooling load, the algorithm sets the compressor speed at the lowest possible value while adjusting the inlet guide vane angle and diffuser vane angle to maximize efficiency, subject to an overriding requirement to prevent surge. The onset of surge is detected via the onset of oscillations of the electric current supplied to the compressor motor, associated with surge-induced oscillations of the torque exerted by and on the compressor rotor. The algorithm can be implemented in any of several computer languages.

Fluidos intravenosos isotónicos en el paciente pediátrico: evolución de la natremia y efectos adversos

OpenAIRE

Toledo Parreño, Juan Diego

2016-01-01

Los fluidos hipotónicos se siguen usando de forma mayoritaria en niños hospitalizados pese al riesgo de hiponatremia iatrogénica, edema cerebral y muerte reportado en la literatura científica y en las advertencias de seguridad de organismos sanitarios internacionales. Se sabe que estímulos frecuentes en los niños hospitalizados inducen secreción no osmótica de ADH . Si a estas circunstancias sumamos el empleo de fluidos hipotónicos como los que resultan del trabajo clásico de Holliday-Se...

Uso de elementos de tierras raras contenidos en los discos duros de computadoras para optimizar la quema de combustibles fluidos

OpenAIRE

Carlos Vallejos; Job Balladares

2014-01-01

La investigación examinó el uso de imanes de neodimio provenientes de los discos duros de computadoras en desuso, y su utilización como optimizadores de la combustión de fluidos tales como propano, butano o la mezcla de los mismos. En la validación del efecto del campo magnético sobre los fluidos en referencia se utilizaron dos cocinas nuevas y dos cocinas previamente utilizadas, con su respectiva alimentación de gas. Los ensayos se realizaron sin y con imanes de neodimio provenientes d...

Modeling of scroll compressors - Improvements

Energy Technology Data Exchange (ETDEWEB)

Duprez, Marie-Eve; Dumont, Eric; Frere, Marc [Thermodynamics Department, Universite de Mons - Faculte Polytechnique, 31 bd Dolez, 7000 Mons (Belgium)

2010-06-15

This paper presents an improvement of the scroll compressors model previously published by. This improved model allows the calculation of refrigerant mass flow rate, power consumption and heat flow rate that would be released at the condenser of a heat pump equipped with the compressor, from the knowledge of operating conditions and parameters. Both basic and improved models have been tested on scroll compressors using different refrigerants. This study has been limited to compressors with a maximum electrical power of 14 kW and for evaporation temperatures ranging from -40 to 15 C and condensation temperatures from 10 to 75 C. The average discrepancies on mass flow rate, power consumption and heat flow rate are respectively 0.50%, 0.93% and 3.49%. Using a global parameter determination (based on several refrigerants data), this model can predict the behavior of a compressor with another fluid for which no manufacturer data are available. (author)

Displacement compressors - acceptance tests

CERN Document Server

International Organization for Standardization. Geneva

1996-01-01

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.

Comprehensive model of a hermetic reciprocating compressor

Science.gov (United States)

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

2017-08-01

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

Estudio de Mercado de la Microencapsulación de Fluidos

OpenAIRE

de Batlle Mercadé, Juan Batlle

2016-01-01

El TFG desarrollado a continuación trata sobre un estudio de mercado de la microencapsulación de fluidos llevado a cabo por petición de una empresa especializada en este producto. Los objetivos de este proyecto son: en primer lugar, dimensionar el mercado de las micropartículas para las zonas geográficas de Europa (EU) y Estados Unidos (EEUU) en cuatro sectores (Pharma, Functional Food, Personal Care y Home Care); en segundo lugar, identificar la demanda no cubierta mediante las necesidades d...

Hermetically Sealed Compressor

Science.gov (United States)

Holtzapple, Mark T.

1994-01-01

Proposed hermetically sealed pump compresses fluid to pressure up to 4,000 atm (400 MPa). Pump employs linear electric motor instead of rotary motor to avoid need for leakage-prone rotary seals. In addition, linear-motor-powered pump would not require packings to seal its piston. Concept thus eliminates major cause of friction and wear. Pump is double-ended diaphragm-type compressor. All moving parts sealed within compressor housing.

New technology of subsea and offshore compressor

Energy Technology Data Exchange (ETDEWEB)

Almasi, Amin

2012-09-15

Subsea compressor is a hot topic. Subsea compressor offers tremendous potentials, but also some obstacles. Active magnetic bearings installed inside the process gas allow the elimination of lubrication and seal systems. High-speed permanent- magnet motor directly drives centrifugal compressor to meet optimum speed, eliminating gear box. This design offers inherent machinery health monitoring features and very compact and reliable train. New technology of hermitically sealed direct drive centrifugal compressor for offshore and subsea applications are discussed and case studies for horizontal and vertical compressor train arrangements are presented. (orig.)

Modelamiento numérico de yacimientos naturalmente fracturados con flujo de fluidos composicional acoplado a deformación geomecánica

OpenAIRE

Arango Acevedo, María Adelaida

2009-01-01

Se desarrolla un modelo matemático que permite evaluar el comportamiento geomecánico en macizos rocosos que contienen fracturas y valorar el cambio de la permeabilidad debido a la variación en el estado de esfuerzos, causado por la diferencia en la presión de los fluidos presentes en el yacimiento, que por su complejidad deben ser analizados como fluidos composicionales. El modelo matemático se plantea en tres dimensiones y en coordenadas cartesianas partiendo de las ecuaciones de flujo de fl...

Performance test of 100 W linear compressor

Energy Technology Data Exchange (ETDEWEB)

Ko, J; Ko, D. Y.; Park, S. J.; Kim, H. B.; Hong, Y. J.; Yeom, H. K. [Korea Institute of Machinery and Materials, Daejeon(Korea, Republic of)

2013-09-15

In this paper, we present test results of developed 100 W class linear compressor for Stirling-type pulse tube refrigerator. The fabricated linear compressor has dual-opposed configuration, free piston and moving magnet type linear motor. Power transfer, efficiency and required pressure waveform are predicted with designed and measured specifications. In experiments, room temperature test with flow impedance is conducted to evaluate performance of developed linear compressor. Flow impedance is loaded to compressor with metering valve for flow resistance, inertance tube for flow inertance and buffer volumes for flow compliance. Several operating parameters such as input voltage, current, piston displacement and pressure wave are measured for various operating frequency and fixed input current level. Behaviors of dynamics and performance of linear compressor as varying flow impedance are discussed with measured experimental results. The developed linear compressor shows 124 W of input power, 86 % of motor efficiency and 60 % of compressor efficiency at its resonant operating condition.

Using helical compressors for coke gas condensation

Energy Technology Data Exchange (ETDEWEB)

Privalov, V E; Rezunenko, Yu I; Lelyanov, N V; Zarnitzkii, G Eh; Gordienko, A A; Derebenko, I F; Venzhega, A G; Leonov, N P; Gorokhov, N N

1982-08-01

Coke oven gas compression is discussed. Presently used multilevel piston compressors are criticized. The paper recommends using helical machines which combine advantages of using volume condensing compressors and compact high-efficiency centrifugal machines. Two kinds of helical compressors are evaluated: dry and oil-filled; their productivities and coke oven gas chemical composition are analyzed. Experiments using helical compressors were undertaken at the Yasinovskii plant. Flowsheet of the installation is shown. Performance results are given in a table. For all operating conditions content of insolubles in oil compounds is found to be lower than the acceptable value (0.08%). Compressor productivity measurements with variable manifold pressure are evaluated. Figures obtained show that efficient condensation of raw coke oven gas is possible. Increasing oil-filled compressor productivity is recommended by decreasing amount of oil injected and simultaneously increasing rotation speed. The dry helical compressor with water seal is found to be most promising for raw coke oven gas condensation. (10 refs.)

An exergy method for compressor performance analysis

Energy Technology Data Exchange (ETDEWEB)

McGovern, J A; Harte, S [Trinity Coll., Dublin (Ireland)

1995-07-01

An exergy method for compressor performance analysis is presented. The purpose of this is to identify and quantify defects in the use of a compressor`s shaft power. This information can be used as the basis for compressor design improvements. The defects are attributed to friction, irreversible heat transfer, fluid throttling, and irreversible fluid mixing. They are described, on a common basis, as exergy destruction rates and their locations are identified. The method can be used with any type of positive displacement compressor. It is most readily applied where a detailed computer simulation program is available for the compressor. An analysis of an open reciprocating refrigeration compressor that used R12 refrigerant is given as an example. The results that are presented consist of graphs of the instantaneous rates of exergy destruction according to the mechanisms involved, a pie chart of the breakdown of the average shaft power wastage by mechanism, and a pie chart with a breakdown by location. (author)

40 CFR 63.1012 - Compressor standards.

Science.gov (United States)

2010-07-01

... is equipped with a system to capture and transport leakage from the compressor drive shaft seal to a... in the referencing subpart. (b) Seal system standard. Each compressor shall be equipped with a seal..., except as provided in § 63.1002(b) and paragraphs (e) and (f) of this section. Each compressor seal...

Fairchild 7B compressor model

International Nuclear Information System (INIS)

Foster, R.E.; Neely, R.S.

1987-01-01

The Fairchild 7B centrifugal compressor used in the X-326 isotopic ''top'' cascade at the Portsmouth Gaseous Diffusion Plant has been modeled using a proprietary computer code called COMPAL by Concepts E.T.I., Inc. of Norwich, VT. The 7B compressor is described and some results of the modeling calculations are presented. Performance characteristics curves (PR/sub b/vs. flow and PR/sub a/) are included for UF 6 gas for two compressor inlet temperatures

Air compressor efficiency in a Vietnamese enterprise

Energy Technology Data Exchange (ETDEWEB)

Yang, Ming [3E and T International, Suite 1506, Building No. 10, Luo Ma Shi Street, Xuan Wu District, Beijing 100052 (China)

2009-06-15

Compressed air systems in a Vietnamese footwear manufacturing enterprise consume about 10% of enterprise's total electric power supply. Energy efficiency of these air compressor systems, either equipped with new and efficient compressors or old and inefficient ones, can only reach between 5% and 10%. In other words, regardless whatever air compressors were installed, energy loss from the compressor systems was over 80%. This study discovered that energy loss was due to non-optimized operations of the air compressor systems and air leakages. The objectives of the paper are to uncover energy saving potential in Vietnamese air compressor systems, demonstrate methodologies used in the auditing and assessment, share auditing and assessment results, and serve a guide on how to analyze energy efficiency in a compressed air system. This paper concludes that energy efficiency investment in air compressor systems in the Vietnamese enterprise could be extremely cost-effective. If the enterprise invests USD 84,000 in the air compressors to improve efficiency performance, the investment capital will be recovered in about six months. The net present value of the investment will be about USD 864,000 at a discount rate of 12%. (author)

Air compressor efficiency in a Vietnamese enterprise

Energy Technology Data Exchange (ETDEWEB)

Yang Ming [3E and T International, Suite 1506, Building No. 10, Luo Ma Shi Street, Xuan Wu District, Beijing 100052 (China)], E-mail: ming.yang7@gmail.com

2009-06-15

Compressed air systems in a Vietnamese footwear manufacturing enterprise consume about 10% of enterprise's total electric power supply. Energy efficiency of these air compressor systems, either equipped with new and efficient compressors or old and inefficient ones, can only reach between 5% and 10%. In other words, regardless whatever air compressors were installed, energy loss from the compressor systems was over 80%. This study discovered that energy loss was due to non-optimized operations of the air compressor systems and air leakages. The objectives of the paper are to uncover energy saving potential in Vietnamese air compressor systems, demonstrate methodologies used in the auditing and assessment, share auditing and assessment results, and serve a guide on how to analyze energy efficiency in a compressed air system. This paper concludes that energy efficiency investment in air compressor systems in the Vietnamese enterprise could be extremely cost-effective. If the enterprise invests USD 84,000 in the air compressors to improve efficiency performance, the investment capital will be recovered in about six months. The net present value of the investment will be about USD 864,000 at a discount rate of 12%.

Air compressor efficiency in a Vietnamese enterprise

International Nuclear Information System (INIS)

Yang Ming

2009-01-01

Compressed air systems in a Vietnamese footwear manufacturing enterprise consume about 10% of enterprise's total electric power supply. Energy efficiency of these air compressor systems, either equipped with new and efficient compressors or old and inefficient ones, can only reach between 5% and 10%. In other words, regardless whatever air compressors were installed, energy loss from the compressor systems was over 80%. This study discovered that energy loss was due to non-optimized operations of the air compressor systems and air leakages. The objectives of the paper are to uncover energy saving potential in Vietnamese air compressor systems, demonstrate methodologies used in the auditing and assessment, share auditing and assessment results, and serve a guide on how to analyze energy efficiency in a compressed air system. This paper concludes that energy efficiency investment in air compressor systems in the Vietnamese enterprise could be extremely cost-effective. If the enterprise invests USD 84,000 in the air compressors to improve efficiency performance, the investment capital will be recovered in about six months. The net present value of the investment will be about USD 864,000 at a discount rate of 12%.

Electrochemical Hydrogen Compressor

Energy Technology Data Exchange (ETDEWEB)

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

2016-01-21

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).

Refrigeration system having standing wave compressor

Science.gov (United States)

Lucas, Timothy S.

1992-01-01

A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

Modification of a compressor performance test bench for liquid slugging observation in refrigeration compressors

Science.gov (United States)

Ola, Max; Thomas, Christiane; Hesse, Ullrich

2017-08-01

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.

Comparison of CFD results for a supercritical CO{sub 2} compressor with compressible and incompressible working fluids

Energy Technology Data Exchange (ETDEWEB)

Kim, Seong Gu; Baik, Seungjoon; Cho, Seong Kuk; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of); Kwon, Jinsu [Hanyang University, Seoul (Korea, Republic of)

2015-10-15

The authors compared flow parameters of S-CO{sub 2} compressor with various fluids to investigate fluid characteristic of S-CO{sub 2}, and performance of pump-derived type (shrouded impeller) compressor. The CFD results showed that the isentropic efficiency of CO{sub 2} case has a comparable performance in comparison to the water since S-CO{sub 2} has a meta-incompressible characteristic near the critical point. Because of the low rotating speed and non-optimized geometry of impeller, the pressure ratio of the compressor is low. However, the authors confirmed that this shrouded type impeller for S-CO{sub 2} compressor showed good performance as much as water case. This results will be reflected in the future S-CO{sub 2} compressor design. As the generation IV reactors are being researched, the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle is identified as one of the promising power conversion cycles. The S-CO{sub 2} cycle has several advantages: high efficiency it has compact cycle components and simple layout. It can be also used for a power conversion system of sodium-cooled fast reactor (SFR) since it can eliminate potential safety issue of the sodium-water reactions. Moreover, the S-CO{sub 2} cycle can be used for small modular reactors (SMR) application since it occupies small footprint and it can designed as an economical dry-cooling system for SMRs. Design of a compressor is the major technical issue in development of S-CO{sub 2} cycle. Main purposes of this experiment are to accumulate operating experience of the S-CO{sub 2} loop, and to obtain fundamental data for the compressor design optimization near the critical point. However, inside the compressor, it is hard to know flow parameters by measurements. Therefore, the authors performed a CFD analysis to obtain useful flow parameters inside the compressor. The main goal of this paper is studying the flow parameters of pump-derived type compressor with S-CO{sub 2}, water, and air fluids to

40 CFR 63.164 - Standards: Compressors.

Science.gov (United States)

2010-07-01

... from the compressor drive shaft seal back to a process or a fuel gas system or to a control device that... compressor shall be equipped with a seal system that includes a barrier fluid system and that prevents... paragraphs (h) and (i) of this section. (b) Each compressor seal system as required in paragraph (a) of this...

Characterization of Multiflux Axial Compressors

International Nuclear Information System (INIS)

Brasnarof, Daniel; Kyung Kyu-Hyung; Rivarola, Martin; Gonzalez Jose; Florido, Pablo; Orellano, Pablo; Bergallo, Juan

2003-01-01

In the present work the results of analytical models of performance are compared with experimental data acquired in the multi flux axial compressor test facility, built in The Pilcaniyeu Technological Complex for the SIGMA project.We describe the experimental circuit and the data of the dispersion inside the axial compressor obtained using a tracer gas through one of the annular inlets.The attained results can be used to validate the design code for the multi flux axial compressors and SIGMA industrial plant

A helium regenerative compressor

International Nuclear Information System (INIS)

Swift, W.L.; Nutt, W.E.; Sixsmith, H.

1994-01-01

This paper discusses the design and performance of a regenerative compressor that was developed primarily for use in cryogenic helium systems. The objectives for the development were to achieve acceptable efficiency in the machine using conventional motor and bearing technology while reducing the complexity of the system required to control contamination from the lubricants. A single stage compressor was built and tested. The compressor incorporates aerodynamically shaped blades on a 218 mm (8.6 inches) diameter impeller to achieve high efficiency. A gas-buffered non-contact shaft seal is used to oppose the diffusion of lubricant from the motor bearings into the cryogenic circuit. Since it is a rotating machine, the flow is continuous and steady, and the machine is very quiet. During performance testing with helium, the single stage machine has demonstrated a pressure ratio of 1.5 at a flow rate of 12 g/s with measured isothermal efficiencies in excess of 30%. This performance compares favorably with efficiencies generally achieved in oil flooded screw compressors

Low-Vibration Oscillating Compressor

Science.gov (United States)

Studer, P. A.

1984-01-01

Oscillating compressor momentum compensated: produces little vibration in its supporting structure. Compressure requires no lubrication and virtually free of wear. Compresses working fluids such as helium, nitrogen or chlorfluorocarbons for Stirling-cycle refrigeration or other purposes. Compressor includes two mutually opposed ferromagnetic pistons of same shape and mass. Electromagnetic flux links both pistons, causing magnetic attraction between them.

33 CFR 154.826 - Vapor compressors and blowers.

Science.gov (United States)

2010-07-01

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

Numerical simulation of radial compressor stage

Science.gov (United States)

Syka, T.; Luňáček, O.

2013-04-01

Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

Numerical simulation of radial compressor stage

OpenAIRE

Luňáček O.; Syka T.

2013-01-01

Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

Transient analysis of a variable speed rotary compressor

International Nuclear Information System (INIS)

Park, Youn Cheol

2010-01-01

A transient simulation model of a rolling piston type rotary compressor is developed to predict the dynamic characteristics of a variable speed compressor. The model is based on the principles of conservation, real gas equations, kinematics of the crankshaft and roller, mass flow loss due to leakage, and heat transfer. For the computer simulation of the compressor, the experimental data were obtained from motor performance tests at various operating frequencies. Using the developed model, re-expansion loss, friction loss, mass flow loss and heat transfer loss is estimated as a function of the crankshaft speed in a variable speed compressor. In addition, the compressor efficiency and energy losses are predicted at various compressor-operating frequencies. Since the transient state of the compressor strongly depends on the system, the developed model is combined with a transient system simulation program to get transient variations of the compression process in the system. Motor efficiency, mechanical efficiency, motor torque and volumetric efficiency are calculated with respect to variation of the driving frequency in a rotary compressor.

Cooled-Spool Piston Compressor

Science.gov (United States)

Morris, Brian G.

1994-01-01

Proposed cooled-spool piston compressor driven by hydraulic power and features internal cooling of piston by flowing hydraulic fluid to limit temperature of compressed gas. Provides sufficient cooling for higher compression ratios or reactive gases. Unlike conventional piston compressors, all parts of compressed gas lie at all times within relatively short distance of cooled surface so that gas cooled more effectively.

Configuration and testing of a saturated vapor helium compressor

International Nuclear Information System (INIS)

Ludwigsen, J.L.; Iwasa, Y.; Smith, J.L.

1986-01-01

A saturated vapor helium compressor was designed and tested as a component of a helium-temperature refrigeration cycle. The use of the cold compressor allows reduction of both the precooling heat exchanger area and main compressor size compared to a conventional cycle due to increased pressure of the return gas. The compressor tested was a single-piston reciprocating device which was controlled with programmable hydraulic/pneumatic logic. The compressor was mounted at the cold end of a CTI Model 1400 helium liquefier. An average compression ratio of 2.4 was obtained and an average efficiency of 82% was achieved. In computing compressor efficiency, external heat leaks to the compressor were neglected

Dense-plasma research using ballistic compressors

International Nuclear Information System (INIS)

Hess, H.

1986-01-01

An introduction is given to research on dense (or nonideal) plasmas which can be generated to advantage by ballistic compressors. Some properties of ballistic compressors are discussed especially in comparison with shock tubes. A short review is given on the history of these devices for high-pressure plasma generation. The present state of the art is reported including research on the two ZIE (Central Institute for Electron Physics) ballistic compressors. (author)

Numerical simulation of radial compressor stage

Directory of Open Access Journals (Sweden)

Luňáček O.

2013-04-01

Full Text Available Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

Economics of water injected air screw compressor systems

Science.gov (United States)

Venu Madhav, K.; Kovačević, A.

2015-08-01

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

30 CFR 75.344 - Compressors.

Science.gov (United States)

2010-07-01

... Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.344 Compressors. (a) Except compressors that are...), shall be equipped with a heat activated fire suppression system meeting the requirements of 75.1107-3...

Harmattan gas plant compressor conversion

Energy Technology Data Exchange (ETDEWEB)

Temple, K. [Altagas Ltd., Calgary, AB (Canada)

2009-07-01

The Harmattan Gas Plant located near the town of Didsbury, Alberta has typical processing units such as amine treating, sulfur recovery, refrigeration, and dehydration. In 1999, a deep cut turbo expander train was added for the extraction of ethane and in 2003 a spec carbon dioxide unit was added. Since its construction in 1961, the plant has undergone many modifications. As such, the plant is a mix of new and old equipment. A 3500 kW Solar Centaur 50LS gas turbine compressor with waste heat recovery was installed at the plant in 2008. This paper reviewed the project from concept to execution and demonstrated how reciprocating compressors were economically replaced with a gas turbine. Altagas had an incentive to invest in the project to lower operating and maintenance costs. Altagas was able to economically replace aging reciprocating compressors with a single turbine driving a centrifugal compressor without any producer subsidies or contract revisions. 2 tabs., 5 figs.

Combined cold compressor/ejector helium refrigerator cycle

International Nuclear Information System (INIS)

Schlafke, A.P.; Brown, D.P.; Wu, K.C.

1984-01-01

This chapter demonstrates how the use of a cold compressor in series with an ejector is an effective way to produce the desired low pressure in a helium refrigeration system. The cold compressor is tentatively located at the low pressure side below the J-T heat exchanger. The ejector is the first stage and the cold compressor is the second stage of the two-stage pumping system. A centrifugal, oil-bearing type compressor was installed on the R and D refrigerator at the Brookhaven National Laboratory. It is determined that the combined cold compressor and ejector system produces a lower temperature on the same load or more cooling at the same temperature compared with a system which uses an ejector alone. Results of the test showed a gain of 20%

ANÁLISE EXPERIMENTAL DO HIDROCARBONETO R290 PARA A SUBSTITUIÇÃO DO CFC12 EM REFRIGERADOR DOMÉSTICO

Directory of Open Access Journals (Sweden)

Jucelino Gomes da Silva

2011-03-01

Full Text Available Recentemente, muita atenção tem sido dada aos chamados fluidos naturais, que são menos agressivos ao meio ambiente e também apresentam grande importância na necessidade latente do aumento da eficiência energética dos equipamentos em comparação aos fluidos sintéticos. O presente trabalho trata de uma análise experimental do hidrocarboneto propano (R290 como fluido refrigerante em um bebedouro de água potável projetado para operar com R12 numa estratégia de drop-in. O bebedouro foi preparado através da instalação de um manômetro na linha de alta pressão e um na linha de baixa pressão, termopares em cinco pontos estratégicos do ciclo termodinâmico: sucção do compressor, descarga do compressor, saída do condensador, entrada do evaporador e saída do evaporador, além da medição da temperatura da água e do ambiente. O ensaio de abaixamento de temperatura foi realizado durante 90 minutos sem atuação do termostato. A carga do hidrocarboneto propano (R290 aplicado ao equipamento foi reduzida em 61,5% com relação ao R12. Foram monitorados os dados de pressões de sucção e descarga do compressor, corrente elétrica consumida pelo compressor e temperaturas nos pontos do ciclo de refrigeração. Os parâmetros obtidos do ensaio foram comparados através do uso do software Coolpack, onde os diagramas pressão-entalpia (P-h para os fluidos foram obtidos e as características operacionais de trabalho de compressão, efeito refrigerante, efeito de condensação e coeficiente de performance (COP foram estudadas. Os resultados obtidos demonstraram um consumo de corrente elétrica 30% inferior em relação à operação com R12, porém, com muitas oscilações durante o tempo. As pressões para o R290 se apresentaram maiores em comparação com o R12. A razão de pressões do R290 foi 28% menor que para o R12. Após 16 minutos de funcionamento ocorreu a formação de gelo na serpentina do evaporador. O COP obtido para o R290 foi

Desenvolvimento de forma farmacêutica líquida de uso oral, isenta de substâncias glicogênicas, com extrato fluido de Mikania glomerata Sprengel - Asteraceae (guaco

Directory of Open Access Journals (Sweden)

N.C. Lubi

Full Text Available Mikania glomerata Sprengel, Asteraceae (guaco é tradicionalmente empregado como expectorante na forma de infusão, extrato fluido, tintura e xarope. Este trabalho teve como objetivo o desenvolvimento de uma forma farmacêutica líquida, isenta de substâncias glicogênicas, veiculando o extrato fluido desta, como substituto do xarope de guaco para pessoas, que por alguma restrição não possam ingerir sacarose ou açúcar invertido, componente dos xaropes em geral. Desenvolveu-se uma formulação líquida, definindo-se as concentrações de conservantes, agentes umectantes, edulcorantes e flavorizantes, testaram-se polímeros, espessantes usuais em processos tecnológicos, para reproduzir a viscosidade fornecida pelos xaropes. Analisou-se o comportamento reológico e uma avaliação preliminar das características físicas do produto. Dos polímeros testados, o alginato de sódio (1% foi o que apresentou melhores resultados frente aos parâmetros analisados, com comportamento reológico semelhante ao dos fluidos Newtonianos, e pH adequado ao uso oral, além da compatibilidade frente ao extrato fluido de guaco.

Orbiting compressor for residential air-conditioners

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Jin; Kim, Woo Young; Ahn, Jong Min [Department of Mechanical Engineering, University of Incheon, 12-1 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea)

2010-01-15

A new type of compressor, called an orbiting compressor, is introduced in this paper. The orbiting compressor is characterized by an orbiting piston, and the piston or orbiter consists of a circular base plate and a ring type vane protruding vertically from the base plate. The orbiter is made to orbit in an annular space formed between two concentric circular walls via an Oldham-ring mechanism, producing two sealed gas pockets on both sides of the vane wrap with a 180 phase difference. This operating mechanism leads to alternating compression and discharge processes, which results in low torque variation. The orbiting compressor has been designed for an R410A residential air conditioner with a cooling capacity of 10.0 kW. The performance of the orbiting compressor model has been analytically investigated, where the volumetric, adiabatic and mechanical efficiencies were calculated to be 94.8%, 90.4% and 93.4%, respectively for the ARI condition. The EER was estimated to be about 10.86 with a motor efficiency of 89%. (author)

Fisiologia do transporte de fluidos e solutos atraves da membrana peritoneal

OpenAIRE

Aguirre,Anna Rita; Abensur,Hugo

2014-01-01

Nesta revisão, são explicados os fenômenos envolvidos nas trocas de fluidos e solutos através da membrana peritoneal, tanto na situação fisiológica quanto no contexto da diálise peritoneal. Para tanto, são utilizados os modelos matemáticos desenvolvidos para estudo do transporte pela membrana, tais como o "Modelo de Poros" e o "Modelo Distributivo". Os ganhos científicos com as pesquisas nesse campo são contemplados e as áreas q...

Centrifugal compressor design for electrically assisted boost

International Nuclear Information System (INIS)

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

2013-01-01

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

Desenvolvimento de fluidos aquosos com bentonita para perfuração de poços de petróleo onshore Development of aqueous fluids with bentonite clay for drilling of onshore oil wells

Directory of Open Access Journals (Sweden)

R. C. A. M Nascimento

2010-06-01

Full Text Available Devido aos grandes desafios encontrados na perfuração de poços, há a necessidade de se desenvolver fluidos com propriedades adequadas e capazes de atender todas as exigências da perfuração, como elevada capacidade de carreamento de sólidos e alta lubricidade, como também fluidos ambientalmente corretos. O grau de impacto dos fluidos de perfuração no meio ambiente depende especialmente do tipo de fluido utilizado, se de base aquosa, oleosa, sintética ou mesmo de base ar. Portanto, é de fundamental importância o desenvolvimento de fluidos com características específicas em cada etapa da perfuração. Sendo assim, este trabalho objetivou o desenvolvimento de fluidos aquosos, com baixo teor de sólidos e propriedades reológicas, de filtração e lubricidade adequadas à perfuração de poços de petróleo onshore. Os fluidos foram formulados utilizando em sua composição bentonita sódica industrializada, aditivos poliméricos e lubrificantes, em diferentes concentrações. O estudo reológico, de filtração e lubricidade mostrou que os fluidos apresentam comportamento pseudoplástico e que os aditivos selecionados desempenham com êxito suas funções de modificadores reológicos, redutores de filtrado e agente lubrificante. Além disto, ficou evidenciada a necessidade de aditivos lubrificantes em fluidos aquosos contendo argila bentonítica e polímeros. A adição de 1% de lubrificante no fluido é suficiente para adequar a capacidade lubrificante dos fluidos.Due to challenges encountered in drilling wells, there is a need to develop fluids that have properties suitable and able to meet all the requirements of drilling, such as, high capacity for carrying of solid and high lubricity. Besides that, they need to be environmentally friend. The degree of impact of drilling fluids in the environment depends on the type of fluid used, if water or oil or synthetic or air based. It is therefore of fundamental importance to develop

Fault detection and diagnosis for refrigerator from compressor sensor

Science.gov (United States)

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

2016-12-06

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.

Thermal modelling of a dry revolving vane compressor

Science.gov (United States)

Ooi, K. T.; Aw, K. T.

2017-08-01

The lubricant used in compressors serves to lubricate, to seal the gaps to reduce internal leakage and to a certain extent, to cool. However, a lubricant free compressor is attractive if lubricants become a source of contaminant, or in areas where the compressor needs be placed under any orientation, such as those in military or portable computing. In this paper, a thermal model for a dry revolving vane compressor is presented. This thermal model sets out to predict the steady-state operating temperatures of the compressor components. The lumped thermal conductance method was employed. The results of the components temperature will be presented and discussed. A high potential for overheating is observed at the shaft bearings.

Pressure field study of the Tevatron cold compressors

International Nuclear Information System (INIS)

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

2003-01-01

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

Pressure Field Study of the Tevatron Cold Compressors

International Nuclear Information System (INIS)

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

2004-01-01

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

NASA low speed centrifugal compressor

Science.gov (United States)

Hathaway, Michael D.

1990-01-01

The flow characteristics of a low speed centrifugal compressor were examined at NASA Lewis Research Center to improve understanding of the flow in centrifugal compressors, to provide models of various flow phenomena, and to acquire benchmark data for three dimensional viscous flow code validation. The paper describes the objectives, test facilities' instrumentation, and experiment preliminary comparisons.

Compressor Has No Moving Macroscopic Parts

Science.gov (United States)

Gasser, Max

1995-01-01

Compressor containing no moving macroscopic parts functions by alternating piston and valve actions of successive beds of magnetic particles. Fabricated easily because no need for precisely fitting parts rotating or sliding on each other. Also no need for lubricant fluid contaminating fluid to be compressed. Compressor operates continuously, eliminating troublesome on/off cycling of other compressors, and decreasing consumption of energy. Phased cells push fluid from bottom to top, adding increments of pressure. Each cell contains magnetic powder particles loose when electromagnet coil deenergized, but tightly packed when coil energized.

Comparative assessment of characteristic part-load performances of screw compressors and turbo-compressors; Vergleich der charakteristischen Teillastwirkungsgrade von Schrauben- und Turboverdichtern

Energy Technology Data Exchange (ETDEWEB)

Brasz, J.J.; Hartmann, K. [Carrier Corp., Syracuse, NY (United States)]|[Carrier Corp., Muenchen (Germany)

2006-07-01

The relative part-load performance of screw compressors and radial compressors is compared. Compressor part load is represented by a 2D characteristic field with the pressure on the vertical axis as a function of mass flow on the horizontal axis, with efficiencies given for any possible combination of pressure and mass flow. While this manner of representation is common for radial compressors, it is new for screw compressors. In the comparison of compression efficiencies, the focus is on vapour compression. For a valid comparative assessment of total compression, also the mechanical and/or electric loss through bearings, transmission, drive and (in case of variable-speed drives) frequency converters must be taken into account. (orig.)

Impact of inlet coherent motions on compressor performance

Science.gov (United States)

Forlese, Jacopo; Spoleti, Giovanni

2017-08-01

Automotive engine induction systems may be characterized by significant flow angularity and total pressure distortion at the compressor inlet. The impact of the swirl on compressor performance should be quantified to guide the design of the induction systems. In diesel engines, the presence of a valve for flow reduction and control of low pressure EGR recirculation could generate coherent motion and influence the performance of the compressor. Starting from experimental map, the compressor speed-lines have been simulated using a 3D CFD commercial code imposing different concept motion at the inlet. The swirl intensity, the direction and the number of vortices have been imposed in order to taking into account some combinations. Finally, a merit function has been defined to evaluate the performance of the compressor with the defined swirl concepts. The aim of the current work is to obtain an indication on the effect of a swirling motion at the compressor inlet on the engine performance and provide a guideline to the induction system design.

Aplicación de la tecnología de los fluidos supercríticos a la purificación de carbohidratos prebióticos

OpenAIRE

Montañés Salcedo, Fernando Óscar

2010-01-01

En la presente memoria se exponen los resultados más relevantes obtenidos durante la realización del trabajo de investigación titulado “Aplicación de la tecnología de fluidos supercríticos a la purificación de carbohidratos prebióticos”, en el que se ha estudiado la posibilidad de fraccionar mezclas complejas de carbohidratos procedentes de isomerizados mediante una tecnología limpia de extracción, como es la extracción con fluidos supercríticos (SFE). Este enfoque resulta completamente noved...

49 CFR 178.337-15 - Pumps and compressors.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Pumps and compressors. 178.337-15 Section 178.337... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.337-15 Pumps and compressors. (a) Liquid pumps or gas compressors, if used, must be of suitable design, adequately protected...

49 CFR 178.338-17 - Pumps and compressors.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Pumps and compressors. 178.338-17 Section 178.338... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.338-17 Pumps and compressors. (a) Liquid pumps and gas compressors, if used, must be of suitable design, adequately protected...

14 CFR 33.27 - Turbine, compressor, fan, and turbosupercharger rotors.

Science.gov (United States)

2010-01-01

... 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...

Theoretical study of a novel refrigeration compressor - Part II: Performance of a rotating discharge valve in the revolving vane (RV) compressor

Energy Technology Data Exchange (ETDEWEB)

Teh, Y.L.; Ooi, K.T. [Thermal and Fluids Engineering Division, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, S639798 (Singapore); Djamari, D. Wibowo [Engineering Mechanics Division, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, S639798 (Singapore)

2009-08-15

A new refrigeration compressor, named 'Revolving Vane (RV) compressor', has been introduced in Part I of this paper series. For a first time in refrigeration compressors, a rotating discharge valve is employed in the RV compressor mainly due to the rotation of the entire cylinder. This paper presents a theoretical investigation on the dynamic behavior of a reed-type discharge valve undergoing rotatory motion, with the primary objective of elucidating the applicability of such valves in refrigeration compressors. Under the application of the Euler-Bernoulli beam theory, a mathematical model of the rotating valve is formulated and the transient response of the valve under centrifugal loads in addition to pressure forces is analyzed. Results have shown that under careful design considerations, the performance as well as the reliability of the rotating discharge valve can be enhanced as compared to a non-rotating valve that has been used in all refrigeration compressors currently. (author)

High Efficiency Centrifugal Compressor for Rotorcraft Applications

Science.gov (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.

2017-01-01

A centrifugal compressor research effort conducted by United Technologies Research Center under NASA Research Announcement NNC08CB03C is documented. The objectives were to identify key technical barriers to advancing the aerodynamic performance of high-efficiency, high work factor, compact centrifugal compressor aft-stages for turboshaft engines; to acquire measurements needed to overcome the technical barriers and inform future designs; to design, fabricate, and test a new research compressor in which to acquire the requisite flow field data. A new High-Efficiency Centrifugal Compressor stage -- splittered impeller, splittered diffuser, 90 degree bend, and exit guide vanes -- with aerodynamically aggressive performance and configuration (compactness) goals were designed, fabricated, and subquently tested at the NASA Glenn Research Center.

Possibility of Thermomechanical Compressor Application in Desalination Plants

Science.gov (United States)

Blagin, E. V.; Shimanov, A. A.; Uglanov, D. A.; Korneev, S. S.

2018-01-01

This article deals with estimation of thermocompressor operating possibility in desalination plant with mechanical vapour compressor. In this plant thermocompressor is used instead of commonly used centrifugal compressor. Preliminary analysis shows that such plant is able to operate, however, power consumption is 3.5-6.5 higher in comparison with traditional MVC plant. In turn, utilization of thermocompressor allows avoiding usual high-frequency drive of centrifugal compressor. Drives with frequency of 50 Hz are enough for thermocompressor when centrifugal compressor requires drives with frequency up to 500 Hz and higher. Approximate thermocompressor dimensions are estimated.

Design features of fans, blowers, and compressors

Science.gov (United States)

Cheremisinoff, N. P.; Cheremisinoff, P. N.

Fan engineering and compression machines are discussed. Basic aspects of fan performance and design are reviewed, and the design and performance characteristics of radial-flow fans, axial-flow fans, and controllable pitch fans are examined in detail. Air-conditioning systems are discussed, and noise, vibration, and mechanical considerations in fans are extensively examined. The thermodynamic principles governing compression machines are reviewed, and piston compressors, rotary compressors, blowers, and centrifugal compressors are discussed.

Modeling of surge in free-spool centrifugal compressors : experimental validation

NARCIS (Netherlands)

Gravdahl, J.T.; Willems, F.P.T.; Jager, de A.G.; Egeland, O.

2004-01-01

The derivation of a compressor characteristic, and the experimental validation of a dynamic model for a variable speed centrifugal compressor using this characteristic, are presented. The dynamic compressor model of Fink et al. is used, and a variable speed compressor characteristic is derived by

New concept single screw compressors and their manufacture technology

Science.gov (United States)

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

2017-08-01

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

Rotary Compressor Noise Analysis Using Mechanisms and Electromagnetics Coupled Approach

OpenAIRE

Chung, Jinah; Lee, Uiyoon; Lee, Jeongbae; Lee, Unseop; Han, Eunsil; Yoon, Jinhwan

2016-01-01

This research is conducted to investigate noise source and design low noise compressors. For improving energy efficiency, the rotary compressor with variable speed brushless DC motor is increasingly adopted for appliances. However brushless DC motor makes more compressor vibration than constant speed motor compressor at high speed operating condition. Therefore it is necessary to reduce noise and vibration for improving air conditioner quality. In this study, compressor’s noise and vibrat...

Uso de elementos de tierras raras contenidos en los discos duros de computadoras para optimizar la quema de combustibles fluidos

Directory of Open Access Journals (Sweden)

Carlos Vallejos

2014-12-01

Full Text Available La investigación examinó el uso de imanes de neodimio provenientes de los discos duros de computadoras en desuso, y su utilización como optimizadores de la combustión de fluidos tales como propano, butano o la mezcla de los mismos. En la validación del efecto del campo magnético sobre los fluidos en referencia se utilizaron dos cocinas nuevas y dos cocinas previamente utilizadas, con su respectiva alimentación de gas. Los ensayos se realizaron sin y con imanes de neodimio provenientes de desechos tecnológicos. Como resultado de la investigación se concluyó que tales imanes son aptos para este propósito, con un rango de optimización en la combustión del gas de entre el 13 y el 20%. Esto pudo demostrarse mediante la aplicación de principios generales de la mecánica de fluidos, del campo magnético y de la termodinámica. Los resultados contribuyen a la búsqueda de estrategias para disminuir el uso de combustibles fosiles en los hogares y otros espacios donde se utiliza gas licuado para la cocción de los alimentos, así cómo para contribuir al bienestar de la microeconomía.

Design of small centrifugal compressor test model for a supercritical CO2 compressor in the fast reactor power plant

International Nuclear Information System (INIS)

Muto, Y.; Ishizuka, T.; Aritomi, M.

2008-01-01

In order to clarify the CO 2 compressor performance in the vicinity of critical point, a research project has been started in Tokyo Institute of Technology based on Japanese government fund. This paper describes how fundamental parameters were selected and sizing of a small and high speed impeller of the test centrifugal compressor. The concept of canned type compressor structures provided with high speed electric motor and preliminary aerodynamic performance prediction are also given. (authors)

High frequency dynamics in centrifugal compressors

NARCIS (Netherlands)

Twerda, A.; Meulendijks, D.; Smeulers, J.P.M.; Handel, R. van den; Lier, L.J. van

2008-01-01

Problems with centrifugal compressors relating to high frequency, i.e. Blade passing frequency (BPF) are increasing. Pulsations and vibrations generated in centrifugal compressors can lead to nuisance, due to strong tonal noise, and even breakdown. In several cases the root cause of a failure or a

Turbofan compressor dynamics during afterburner transients

Science.gov (United States)

Kurkov, A. P.

1976-01-01

The effects of afterburner light-off and shut-down transients on the compressor stability are investigated. The reported experimental results are based on detailed high response pressure and temperature measurements on the TF30-P-3 turbofan engine. The tests were performed in an altitude test chamber simulating high altitude engine operation. It is shown that during both types of transients, flow breaks down in the forward part of the fan bypass duct. At a sufficiently low engine inlet pressure this resulted in a compressor stall. Complete flow breakdown within the compressor was preceded by a rotating stall. At some locations in the compressor, rotating stall cells initially extended only through part of the blade span. For the shutdown transient the time between first and last detected occurrence of rotating stall is related to the flow Reynolds number. An attempt was made to deduce the number and speed of propagation of rotating stall cells.

Pulse compressor with aberration correction

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-30

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

Rotating stall simulation for axial and centrifugal compressors

Science.gov (United States)

Halawa, Taher; Gadala, Mohamed S.

2017-05-01

This study presents a numerical simulation of the rotating stall phenomenon in axial and centrifugal compressors with detailed descriptions of stall precursors and its development with time. Results showed that the vaneless region of the centrifugal compressor is the most critical location affected by stall. It was found that the tip leakage flow and the back flow impingement are the main cause of the stall development at the impeller exit area for centrifugal compressors. The results of the axial compressor simulations indicated that the early separated flow combined with the tip leakage flow can block the impeller passages during stall.

Compressor Surge Control Design Using Linear Matrix Inequality Approach

OpenAIRE

Uddin, Nur; Gravdahl, Jan Tommy

2017-01-01

A novel design for active compressor surge control system (ASCS) using linear matrix inequality (LMI) approach is presented and including a case study on piston-actuated active compressor surge control system (PAASCS). The non-linear system dynamics of the PAASCS is transformed into linear parameter varying (LPV) system dynamics. The system parameters are varying as a function of the compressor performance curve slope. A compressor surge stabilization problem is then formulated as a LMI probl...

Desenvolvimento embrionário de oócitos bovinos mantidos em fluido folicular bovino de folículos de diferentes diâmetros

Directory of Open Access Journals (Sweden)

Lucio Pereira Rauber

2003-01-01

Full Text Available Oócitos bovinos têm sido mantidos em fluido folicular como meio para transporte e para aumento de sua competência, antes da maturação. Oitocentos e oitenta e um (881 oócitos foram aspirados de folículos de 2 a 8mm, de ovários de abatedouro, para avaliar o efeito da manutenção de oócitos bovinos em fluido folicular bovino de folículos de diferentes tamanhos sobre o desenvolvimento embrionário. Os oócitos foram distribuídos aleatoriamente em quatro tratamentos, com sete repetições cada. No grupo controle (n=217, os oócitos foram maturados por 24h em TCM-199 com Soro de Égua em Estro (SEE, piruvato e rFSH-h, em estufa a 39°C, com 5,00% de CO2 e umidade saturada. No tratamento FFpequeno (n=216, os oócitos foram mantidos por 6h em fluido folicular de folículos de 3 a 5mm a 30°C e posteriormente maturados por 18h nas mesmas condições do grupo controle. Os oócitos dos tratamentos FFmédio (n=226 e FFgrande (n=222 foram mantidos em fluido folicular de folículos com 5,1 a 8mm e folículos maiores de 8,1mm, respectivamente e, após, maturados por 18h. Após a fecundação por 18h, os zigotos foram cultivados por 8 dias em SOFaaci com 5,00% de SEE, em estufa a 39°C, em bolsas gaseificadas com 5,00%CO2, 5,00%O2 e 90,00%N2. Oócitos do grupo FFpequeno resultaram em menor (P;0,05 entre os grupos. O fluido folicular de folículos médios e grandes pode ser utilizado para o manutenção de oócitos bovinos por 6h a 30°C, antes da maturação por 18h.

Modal characteristics and fatigue strength of compressor blades

International Nuclear Information System (INIS)

Kim, Kyung Kook; Lee, Young Shin

2014-01-01

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

Modal characteristics and fatigue strength of compressor blades

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Kook [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of); Lee, Young Shin [Chungnam National University, Daejeon (Korea, Republic of)

2014-04-15

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

Experimental Pressure-Volume diagrams of scroll compressors

OpenAIRE

Picavet, Alain; Ginies, Pierre

2014-01-01

This paper presents the results of tests led with scroll compressors to establish pressure-volume diagrams. Two compressors were thinly instrumented with pressure and displacement sensors so as to follow the whole compression process, from suction to exhaust. A gear coder was set to mark off the closing and opening of gas pockets, and to study the speed variations occurring during a single rotation. These tests help to understand the various phenomena met in a compressor, such as back-flow, o...

Real-time trend monitoring of gas compressor stations

Energy Technology Data Exchange (ETDEWEB)

Van Hardeveld, T. (Nova, an Alberta Corp., AB (Canada))

1991-02-01

The authors' company has developed a machinery health monitoring system (MHealth) for short-term and long-term historical trending and analysis of data from its 40 gas compressor stations. The author discusses the benefits of real-time trending in troubleshooting operations, in preventative maintenance scheduling and cites specific applications in the startup operations of several new gas compressor/centrifugal compressor units.

A high pressure centrifugal oxygen compressor

International Nuclear Information System (INIS)

Larsen, L.P.

1986-01-01

The application of a centrifugal compressor train to 5860 kPa(g) (850 psig) for a coal gasification plant is discussed. Special considerations in the application, installation, and operation of the equipment are presented. Discussion includes such topics as compressor controls, machinery protection, noise, personnel safety, and operation of the equipment

Sound reduction of air compressors using a systematic approach

Science.gov (United States)

Moylan, Justin Tharp

The noise emitted by portable electric air compressors can often be a nuisance or potentially hazardous to the operator or others nearby. Therefore, reducing the noise of these air compressors is desired. This research focuses on compressors with a reciprocating piston design as this is the most common type of pump design for portable compressors. An experimental setup was developed to measure the sound and vibration of the air compressors, including testing inside a semi-anechoic chamber. The design of a quiet air compressor was performed in four stages: 1) Teardown and benchmarking of air compressors, 2) Identification and isolation of noise sources, 3) Development of individual means to quiet noise sources, 4) Selection and testing of integrated solutions. The systematic approach and results for each of these stages will be discussed. Two redesigned solutions were developed and measured to be approximately 65% quieter than the previous unmodified compressor. An additional analysis was performed on the solutions selected by the participants involved in the selection process. This analysis involved determining which of the design criteria each participant considered most important when selecting solutions. The results from each participant were then compared to their educational background and experience and correlations were identified. The correlations discovered suggest that educational background and experience may be key determinants for the preference models developed.

40 CFR 63.1031 - Compressors standards.

Science.gov (United States)

2010-07-01

... the compressor drive shaft seal to a process or a fuel gas system or to a closed vent system that... specified in the referencing subpart. (b) Seal system standard. Each compressor shall be equipped with a seal system that includes a barrier fluid system and that prevents leakage of process fluid to the...

Investigation of axial positioning for flexural compressors

Science.gov (United States)

Riggle, Peter

1991-01-01

The testing of the research compressor is presented. The research compressor was assembled and disassembled in order to show the consistency in which the piston and rod could be aligned with a .0004 inch radial gap around the piston. A full set of tests was completed for the first assembly, which is referred to as assembly no. 1. The compressor was disassembled and assembled a second time (assembly no. 2). Assembly no. 2 was only tested statically due to the time constraint. Results are discussed.

Numerical simulation investigation on centrifugal compressor performance of turbocharger

International Nuclear Information System (INIS)

Li, Jie; Yin, Yuting; Li, Shuqi; Zhang, Jizhong

2013-01-01

In this paper, the mathematical model of the flow filed in centrifugal compressor of turbocharger was studied. Based on the theory of computational fluid dynamics (CFD), performance curves and parameter distributions of the compressor were obtained from the 3-D numerical simulation by using CFX. Meanwhile, the influences of grid number and distribution on compressor performance were investigated, and numerical calculation method was analyzed and validated, through combining with test data. The results obtained show the increase of the grid number has little influence on compressor performance while the grid number of single-passage is above 300,000. The results also show that the numerical calculation mass flow rate of compressor choke situation has a good consistent with test results, and the maximum difference of the diffuser exit pressure between simulation and experiment decrease to 3.5% with the assumption of 6 kPa additional total pressure loss at compressor inlet. The numerical simulation method in this paper can be used to predict compressor performance, and the difference of total pressure ratio between calculation and test is less than 7%, and the total-to-total efficiency also have a good consistent with test.

Numerical simulation investigation on centrifugal compressor performance of turbocharger

Energy Technology Data Exchange (ETDEWEB)

Li, Jie [China Iron and Steel Research Institute Group, Beijing (China); Yin, Yuting [China North Engine Research Institute, Datong (China); Li, Shuqi; Zhang, Jizhong [Science and Technology Diesel Engine Turbocharging Laboratory, Datong (China)

2013-06-15

In this paper, the mathematical model of the flow filed in centrifugal compressor of turbocharger was studied. Based on the theory of computational fluid dynamics (CFD), performance curves and parameter distributions of the compressor were obtained from the 3-D numerical simulation by using CFX. Meanwhile, the influences of grid number and distribution on compressor performance were investigated, and numerical calculation method was analyzed and validated, through combining with test data. The results obtained show the increase of the grid number has little influence on compressor performance while the grid number of single-passage is above 300,000. The results also show that the numerical calculation mass flow rate of compressor choke situation has a good consistent with test results, and the maximum difference of the diffuser exit pressure between simulation and experiment decrease to 3.5% with the assumption of 6 kPa additional total pressure loss at compressor inlet. The numerical simulation method in this paper can be used to predict compressor performance, and the difference of total pressure ratio between calculation and test is less than 7%, and the total-to-total efficiency also have a good consistent with test.

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

Science.gov (United States)

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

2018-01-01

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

Surge recovery techniques for the Tevatron cold compressors

International Nuclear Information System (INIS)

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

2006-01-01

The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, made by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. 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

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

Science.gov (United States)

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

1979-01-01

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

Compressor Part I: Measurement and Design Modeling

Directory of Open Access Journals (Sweden)

Thomas W. Bein

1999-01-01

method used to design the 125-ton compressor is first reviewed and some related performance curves are predicted based on a quasi-3D method. In addition to an overall performance measurement, a series of instruments were installed on the compressor to identify where the measured performance differs from the predicted performance. The measurement techniques for providing the diagnostic flow parameters are also described briefly. Part II of this paper provides predictions of flow details in the areas of the compressor where there were differences between the measured and predicted performance.

Compressor ported shroud for foil bearing cooling

Science.gov (United States)

Elpern, David G [Los Angeles, CA; McCabe, Niall [Torrance, CA; Gee, Mark [South Pasadena, CA

2011-08-02

A compressor ported shroud takes compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.

Novel Long Stroke Reciprocating Compressor for Energy Efficient Jaggery Making

Science.gov (United States)

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

2017-08-01

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

Modelling and measurement of a moving magnet linear compressor performance

International Nuclear Information System (INIS)

Liang, Kun; Stone, Richard; Davies, Gareth; Dadd, Mike; Bailey, Paul

2014-01-01

A novel moving magnet linear compressor with clearance seals and flexure bearings has been designed and constructed. It is suitable for a refrigeration system with a compact heat exchanger, such as would be needed for CPU cooling. The performance of the compressor has been experimentally evaluated with nitrogen and a mathematical model has been developed to evaluate the performance of the linear compressor. The results from the compressor model and the measurements have been compared in terms of cylinder pressure, the ‘P–V’ loop, stroke, mass flow rate and shaft power. The cylinder pressure was not measured directly but was derived from the compressor dynamics and the motor magnetic force characteristics. The comparisons indicate that the compressor model is well validated and can be used to study the performance of this type of compressor, to help with design optimization and the identification of key parameters affecting the system transients. The electrical and thermodynamic losses were also investigated, particularly for the design point (stroke of 13 mm and pressure ratio of 3.0), since a full understanding of these can lead to an increase in compressor efficiency. - Highlights: • Model predictions of the performance of a novel moving magnet linear compressor. • Prototype linear compressor performance measurements using nitrogen. • Reconstruction of P–V loops using a model of the dynamics and electromagnetics. • Close agreement between the model and measurements for the P–V loops. • The design point motor efficiency was 74%, with potential improvements identified

Axial and Centrifugal Compressor Mean Line Flow Analysis Method

Science.gov (United States)

Veres, Joseph P.

2009-01-01

This paper describes a method to estimate key aerodynamic parameters of single and multistage axial and centrifugal compressors. This mean-line compressor code COMDES provides the capability of sizing single and multistage compressors quickly during the conceptual design process. Based on the compressible fluid flow equations and the Euler equation, the code can estimate rotor inlet and exit blade angles when run in the design mode. The design point rotor efficiency and stator losses are inputs to the code, and are modeled at off design. When run in the off-design analysis mode, it can be used to generate performance maps based on simple models for losses due to rotor incidence and inlet guide vane reset angle. The code can provide an improved understanding of basic aerodynamic parameters such as diffusion factor, loading levels and incidence, when matching multistage compressor blade rows at design and at part-speed operation. Rotor loading levels and relative velocity ratio are correlated to the onset of compressor surge. NASA Stage 37 and the three-stage NASA 74-A axial compressors were analyzed and the results compared to test data. The code has been used to generate the performance map for the NASA 76-B three-stage axial compressor featuring variable geometry. The compressor stages were aerodynamically matched at off-design speeds by adjusting the variable inlet guide vane and variable stator geometry angles to control the rotor diffusion factor and incidence angles.

Towards Large Eddy Simulation of gas turbine compressors

Science.gov (United States)

McMullan, W. A.; Page, G. J.

2012-07-01

With increasing computing power, Large Eddy Simulation could be a useful simulation tool for gas turbine axial compressor design. This paper outlines a series of simulations performed on compressor geometries, ranging from a Controlled Diffusion Cascade stator blade to the periodic sector of a stage in a 3.5 stage axial compressor. The simulation results show that LES may offer advantages over traditional RANS methods when off-design conditions are considered - flow regimes where RANS models often fail to converge. The time-dependent nature of LES permits the resolution of transient flow structures, and can elucidate new mechanisms of vorticity generation on blade surfaces. It is shown that accurate LES is heavily reliant on both the near-wall mesh fidelity and the ability of the imposed inflow condition to recreate the conditions found in the reference experiment. For components embedded in a compressor this requires the generation of turbulence fluctuations at the inlet plane. A recycling method is developed that improves the quality of the flow in a single stage calculation of an axial compressor, and indicates that future developments in both the recycling technique and computing power will bring simulations of axial compressors within reach of industry in the coming years.

Utilização de código aberto de dinâmica de fluidos computacional para estudo de placas de orifício

OpenAIRE

Thiago Teixeira Kunz

2014-01-01

Este trabalho apresenta simulações numéricas de escoamento de fluidos através de placas de orifício, elementos primários de medição de vazão, em comparação aos resultados esperados por normas internacionais. O coeficiente de descarga usado para a determinação da vazão de um escoamento em uma tubulação foi obtido numericamente através da aplicação do modelo de turbulência de baixo Reynolds proposto por Launder-Sharma, resolvido através de um código aberto de Dinâmica de Fluidos Computacional. ...

SIMULACIÓN NUMÉRICA DE FLUJO MONOFÁSICO DE FLUIDOS ACOPLADO A DEFORMACIÓN GEOMECÁNICA

Directory of Open Access Journals (Sweden)

MARIA ADELAIDA ARANGO ACEVEDO

2010-01-01

Full Text Available La simulación de flujo de fluidos en medios porosos es usada en la industria petrolera como herramienta para caracterizar yacimientos. Sin embargo, el análisis se ha llevado a cabo de manera convencional con suposiciones que deben ser levantadas para los yacimientos con complejidades no consideradas anteriormente. En la actualidad se encuentra que los yacimientos no son ideales como se pensaba y que las propiedades petrofísicas varían¿ esta es la base de la simulación acoplada a geomecánica. La ecuación de flujo de fluidos se plantea para un yacimiento naturalmente fracturado con flujo monofásico y se acopla con las ecuaciones de deformación por medio de las relaciones de esfuerzo ¿ deformación ¿ presión. Estas son resueltas usando la técnica de diferencias finitas y un método iterativo tipo Picard. El resultado es un simulador numérico para la interpretación de pruebas de presión que considera los cambios de la permeabilidad con la variación del esfuerzo utilizando el módulo de permeabilidad.

Variable speed gas engine-driven air compressor system

Science.gov (United States)

Morgan, J. R.; Ruggles, A. E.; Chen, T. N.; Gehret, J.

1992-11-01

Tecogen Inc. and Ingersoll-Rand Co. as a subcontractor have designed a nominal 150-hp gas engine-driven air compressor utilizing the TECODRIVE 8000 engine and the Ingersoll-Rand 178.5-mm twin screw compressor. Phase 1 included the system engineering and design, economic and applications studies, and a draft commercialization plan. Phase 2 included controls development, laboratory prototype construction, and performance testing. The testing conducted verified that the compressor meets all design specifications.

Efeito do Arrefecimento Causado pelo Fluido Durante a Soldagem em Operação em Tubulações com Espessura de Parede de 6 e 11 mm

Directory of Open Access Journals (Sweden)

Jefferson Pinto Soares

Full Text Available Resumo Este trabalho compara a influência do arrefecimento causado por um fluído em circulação e em contato com a parede interna de uma tubulação, que caracteriza a soldagem em operação. Foram avaliadas duas espessuras de parede do tubo e duas temperaturas do fluido interno. A soldagem foi realizada na ligação de conexões de aço ASTM A105 a um tubo API 5L Gr X60 com espessura de 11 mm e de 6 mm, utilizando os processos TIG (GTAW e eletrodo revestido (SMAW. A circulação do fluido foi feita com água potável em duas faixas de temperatura, de 6 a 10 °C e 18 a 36 °C. Durante a soldagem, a temperatura interna do tubo e a taxa de resfriamento foram monitoradas. Foram preparadas quatro juntas soldadas, avaliadas por ensaios não destrutivos (inspeção visual, líquido penetrante, partículas magnéticas e ultrassom, ensaios destrutivos (tração, dobramento, impacto, fratura e dureza e análise macrográfica e micrográfica. Os resultados mostram que, com os procedimentos adotados, não é necessária a adoção de cuidados especiais quanto à possibilidade de perfuração e vazamento de fluido durante a soldagem em operação. Houve evidencias que o efeito do arrefecimento do fluido no interior do tubo foi mais significativo que a espessura da parede do tubo no aumento da taxa de resfriamento. Ainda, a temperatura do fluido em circulação no tubo exerceu papel secundário no aumento da taxa de resfriamento e na redução da temperatura máxima na parede interna do tubo. O arrefecimento causado pelo fluido provocou aumento na dureza da ZF e ZTA, reduziu o alongamento no ensaio de tração, porém ainda em valores adequados. Estes comportamentos foram mais observados no tubo de menor espessura, de 6 mm. Foi possível, pelos resultados dos ensaios não destrutivos e ensaios mecânicos obtidos, qualificar os procedimentos de soldagem, com base nas normas especializadas neste processo.

Sorption compressor/mechanical expander hybrid refrigeration

Science.gov (United States)

Jones, J. A.; Britcliffe, M.

1987-01-01

Experience with Deep Space Network (DSN) ground-based cryogenic refrigerators has proved the reliability of the basic two-stage Gifford-McMahon helium refrigerator. A very long life cryogenic refrigeration system appears possible by combining this expansion system or a turbo expansion system with a hydride sorption compressor in place of the usual motor driven piston compressor. To test the feasibility of this system, a commercial Gifford-McMahon refrigerator was tested using hydrogen gas as the working fluid. Although no attempt was made to optimize the system for hydrogen operation, the refrigerator developed 1.3 W at 30 K and 6.6 W at 60 K. The results of the test and of theoretical performances of the hybrid compressor coupled to these expansion systems are presented.

Compressor airfoil tip clearance optimization system

Science.gov (United States)

Little, David A.; Pu, Zhengxiang

2015-08-18

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.

Modeling and control of compressor flow instabilities

NARCIS (Netherlands)

Willems, F.P.T.; Jager, de A.G.

1999-01-01

Compressors are widely used for the pressurization of fluids. Applications involve air compression for use in aircraft engines and pressurization and transportation of gas in the process and chemical industries. The article focuses on two commonly used types of continuous flow compressors: the axial

Experimental Investigation of Centrifugal Compressor Stabilization Techniques

Science.gov (United States)

Skoch, Gary J.

2003-01-01

Results from a series of experiments to investigate techniques for extending the stable flow range of a centrifugal compressor are reported. The research was conducted in a high-speed centrifugal compressor at the NASA Glenn Research Center. The stabilizing effect of steadily flowing air-streams injected into the vaneless region of a vane-island diffuser through the shroud surface is described. Parametric variations of injection angle, injection flow rate, number of injectors, injector spacing, and injection versus bleed were investigated for a range of impeller speeds and tip clearances. Both the compressor discharge and an external source were used for the injection air supply. The stabilizing effect of flow obstructions created by tubes that were inserted into the diffuser vaneless space through the shroud was also investigated. Tube immersion into the vaneless space was varied in the flow obstruction experiments. Results from testing done at impeller design speed and tip clearance are presented. Surge margin improved by 1.7 points using injection air that was supplied from within the compressor. Externally supplied injection air was used to return the compressor to stable operation after being throttled into surge. The tubes, which were capped to prevent mass flux, provided 9.3 points of additional surge margin over the baseline surge margin of 11.7 points.

Preliminary Design and Model Assessment of a Supercritical CO2 Compressor

Directory of Open Access Journals (Sweden)

Zhiyuan Liu

2018-04-01

Full Text Available The compressor is a key component in the supercritical carbon dioxide (SCO2 Brayton cycle. In this paper, the authors designed a series of supercritical CO2 compressors with different parameters. These compressors are designed for 100 MWe, 10 MWe and 1 MWe scale power systems, respectively. For the 100 MWe SCO2 Brayton cycle, an axial compressor has been designed by the Smith chart to test whether an axial compressor is suitable for the SCO2 Brayton cycle. Using a specific speed and a specific diameter, the remaining two compressors were designed as centrifugal compressors with different pressure ratios to examine whether models used for air in the past are applicable to SCO2. All compressors were generated and analyzed with internal MATLAB programs coupled with the NIST REFPROP database. Finally, the design results are all checked by numerical simulations due to the lack of reliable experimental data. Research has found that in order to meet the de Haller stall criterion, axial compressors require a considerable number of stages, which introduces many additional problems. Thus, a centrifugal compressor is more suitable for the SCO2 Brayton cycle, even for a 100 MWe scale system. For the performance prediction model of a centrifugal compressor, the stall predictions are compared with steady numerical calculation, which indicates that past stall criteria may also be suitable for SCO2 compressors, but more validations are needed. However, the accuracy of original loss models is found to be inadequate, particularly for lower flow and higher pressure ratio cases. Deviations may be attributed to the underestimation of clearance loss according to the result of steady simulation. A modified model is adopted which can improve the precision to a certain extent, but more general and reasonable loss models are needed to improve design accuracy in the future.

Ambientes Virtuales Para la enseñanza de la Mecánica de Fluidos: Algunos ejemplos simplificados aplicando ANSYS

Directory of Open Access Journals (Sweden)

Watson L. Vargas

2005-01-01

Full Text Available Para que un ambiente de enseñanza virtual pueda soportar un aprendizaje real, dichos ambientes deben proveer interacciones enseñanza-aprendizaje de alto nivel. En este artículo, se muestra como una herramienta computacional como ANSYS puede proveer un ambiente virtual para el aprendizaje de la mecánica de fluidos no sólo a nivel de pregrado si no también a niveles superiores. Las simulaciones computacionales, --aplicando ANSYS/FLOTRAN-CFD o cualquiera otro software de capacidades similares--, en el contexto de la enseñanza de la mecánica de fluidos son de interés fundamental dado que soportan un ambiente de simulación poderoso que puede aplicarse no sólo a la comprensión de ideas y conceptos fundamentales sino tambien al diseño y optimización de procesos de aplicación práctica

Speed and surge control for a lower order centrifugal compressor model

Directory of Open Access Journals (Sweden)

Jan T. Gravdahl

1998-01-01

Full Text Available A model of a variable speed centrifugal compression system is presented. The model is based on the work of Greitzer (1976, but the compressor characteristic is developed by modelling the losses in the compressor. For surge control, a close coupled valve is employed. This valve is placed immediately downstream of the compressor, and the pressure drop over the valve is used as the control variable. This makes it possible to manipulate the shape of the equivalent compressor, consisting of compressor and valve. The speed of the compressor is controlled with a PI-controller. Semi-global exponential stability of the model with the proposed controllers is proven by the use of Lyapunovs theorem.

IC ENGINE SUPERCHARGING AND EXHAUST GAS RECIRCULATION USING JET COMPRESSOR

Directory of Open Access Journals (Sweden)

Adhimoulame Kalaisselvane

2010-01-01

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.

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

2014-02-01

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.

Economics of water injected air screw compressor systems

OpenAIRE

Madhav, K. V.; Kovacevic, A.

2015-01-01

There is a growing need for compressed air free of entrained oil to be used in industry. In many cases it can be supplied by oil flooded screw compressors with multi stage filtration systems, or by oil free screw compressors. However, if water injected screw compressors can be made to operate reliably, they could be more efficient and therefore cheaper to operate. Unfortunately, to date, such machines have proved to be insufficiently reliable and not cost effective. This paper describes an in...

Kinetics of a gas adsorption compressor

International Nuclear Information System (INIS)

Chan, C.K.; Elleman, D.D.; Tward, E.

1984-01-01

This chapter uses a two-phase model to analyze the transients of a gas adsorption compressor. The modeling of the adsorption process is based on complete thermal and mechanical equilibrium between the gaseous phase and the adsorbed gas phase. The theories and techniques that have been developed for a two-phase system are used to predict the pressure, the temperature and the mass flow transients in a gas sorption compressor. The analytical solutions are then compared with the performance of a laboratory gas adsorption compressor. A computer code was written to solve the governing equations, using a standard forward marching predictor-corrector method. It is found that while the analytical model overpredicts the pressure and the temperature transient, it predicts the general trend of the transient profile and the existence of the turning point

Prediction of active control of subsonic centrifugal compressor rotating stall

Science.gov (United States)

Lawless, Patrick B.; Fleeter, Sanford

1993-01-01

A mathematical model is developed to predict the suppression of rotating stall in a centrifugal compressor with a vaned diffuser. This model is based on the employment of a control vortical waveform generated upstream of the impeller inlet to damp weak potential disturbances that are the early stages of rotating stall. The control system is analyzed by matching the perturbation pressure in the compressor inlet and exit flow fields with a model for the unsteady behavior of the compressor. The model was effective at predicting the stalling behavior of the Purdue Low Speed Centrifugal Compressor for two distinctly different stall patterns. Predictions made for the effect of a controlled inlet vorticity wave on the stability of the compressor show that for minimum control wave magnitudes, on the order of the total inlet disturbance magnitude, significant damping of the instability can be achieved. For control waves of sufficient amplitude, the control phase angle appears to be the most important factor in maintaining a stable condition in the compressor.

Comprehensive 3D-elastohydrodynamic simulation of hermetic compressor crank drive

Science.gov (United States)

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

2017-08-01

Mechanical, electrical and thermodynamic losses form the major loss mechanisms of hermetic compressors for refrigeration application. The present work deals with the investigation of the mechanical losses of a hermetic compressor crank drive. Focus is on 3d-elastohydrodynamic (EHD) modelling of the journal bearings, piston-liner contact and piston secondary motion in combination with multi-body and structural dynamics of the crank drive elements. A detailed description of the model development within the commercial software AVL EXCITE Power Unit is given in the work. The model is used to create a comprehensive analysis of the mechanical losses of a hermetic compressor. Further on, a parametric study concerning oil viscosity and compressor speed is carried out which shows the possibilities of the usage of the model in the development process of hermetic compressors for refrigeration application. Additionally, the usage of the results in an overall thermal network for the determination of the thermal compressor behaviour is discussed.

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

Science.gov (United States)

Xu, Jiu; Hrnjak, Pega

2017-08-01

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

NASA Glenn's Single-Stage Axial Compressor Facility Upgraded

Science.gov (United States)

Brokopp, Richard A.

2004-01-01

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

Modeling and analysis of an open-drive Z-compressor

Science.gov (United States)

Ziviani, Davide; Groll, Eckhard A.

2017-08-01

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.

Safe and efficient operation of multistage cold compressor systems

International Nuclear Information System (INIS)

Kauschke, M.; Haberstroh, C.; Quack, H.

1996-01-01

Large refrigeration rates in the temperature range of super fluid helium can only be obtained with the help of centrifugal cold compressors. For the large 2 K systems, four compression stages are necessary to reach atmospheric pressure. Centrifugal cold compressors are quite sensitive to mass flow and suction temperature variations; but these have to be expected in a real system. The first step in the systems design is to find safe and efficient quasi-stationary modes of operation. The system which is being proposed for the TESLA refrigerators relies on two features. The first is to allow the room temperature screw compressor, downstream of the cold compressors to work occasionally with a subatmospheric suction pressure. The second is to stabilize the suction temperature of the third stage of compression at about 10 K. With these features it is possible, that in all modes of operation all four compressor stages operate exactly at their design point

The Study of Vibration Processes in Oil Flooded Screw Compressors

Directory of Open Access Journals (Sweden)

I. V. Filippov

2014-01-01

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

Dual-worm screw compressors; Compresseurs bi-vis

Energy Technology Data Exchange (ETDEWEB)

Baleydier, J P [Bitzer France, 69 - Lyon (France)

1998-12-31

Low power worm-screw moto-compressors are used in any king of refrigerating machineries and more and more in air conditioning systems. This paper presents the principle of dual-screw moto-compressors: worm-screw technology, role of oil (lubrication, tightness, cooling), compression, internal pressure, power reduction, lubrication, economizer, operation, model selection and accessories. (J.S.)

Dual-worm screw compressors; Compresseurs bi-vis

Energy Technology Data Exchange (ETDEWEB)

Baleydier, J.P. [Bitzer France, 69 - Lyon (France)

1997-12-31

Low power worm-screw moto-compressors are used in any king of refrigerating machineries and more and more in air conditioning systems. This paper presents the principle of dual-screw moto-compressors: worm-screw technology, role of oil (lubrication, tightness, cooling), compression, internal pressure, power reduction, lubrication, economizer, operation, model selection and accessories. (J.S.)

Stall Margin Improvement in a Centrifugal Compressor through Inducer Casing Treatment

Directory of Open Access Journals (Sweden)

V. V. N. K. Satish Koyyalamudi

2016-01-01

Full Text Available The increasing trend of high stage pressure ratio with increased aerodynamic loading has led to reduction in stable operating range of centrifugal compressors with stall and surge initiating at relatively higher mass flow rates. The casing treatment technique of stall control is found to be effective in axial compressors, but very limited research work is published on the application of this technique in centrifugal compressors. Present research was aimed to investigate the effect of casing treatment on the performance and stall margin of a high speed, 4 : 1 pressure ratio centrifugal compressor through numerical simulations using ANSYS CFX software. Three casing treatment configurations were developed and incorporated in the shroud over the inducer of the impeller. The predicted performance of baseline compressor (without casing treatment was in good agreement with published experimental data. The compressor with different inducer casing treatment geometries showed varying levels of stall margin improvement, up to a maximum of 18%. While the peak efficiency of the compressor with casing treatment dropped by 0.8%–1% compared to the baseline compressor, the choke mass flow rate was improved by 9.5%, thus enhancing the total stable operating range. The inlet configuration of the casing treatment was found to play an important role in stall margin improvement.

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

Directory of Open Access Journals (Sweden)

VADAN, I.

2009-06-01

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.

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

Science.gov (United States)

Ackermann, R. A.

1985-01-01

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

An alternative compressor. A study; Alternativ kompressor. En udredning

Energy Technology Data Exchange (ETDEWEB)

Dall, O.; Jensen, F.; Danig, P.O.; Ritchie, E.; Kierkegaard, P.

1997-10-01

A linear compressor would be suitable for refrigerating systems with small effect. A computerized control system can be used to control the speed of a linear engine. A new compressor/engine with much improved energy efficiency can be designed to operate oil-free. The novel design of a compressor with smaller piston displacement is smaller than the existing models and thus more suitable for the future refrigerators. (EG) EFP-97. 71 refs.

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)

2011-07-01

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.

Identifying lubricant options for compressor bearing designs

Science.gov (United States)

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

2017-08-01

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.

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)

2004-07-01

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)

Funcionamiento de un termosifón cilíndrico con distintos fluidos de trabajo

OpenAIRE

Arcís Tellería, José

2010-01-01

Actualmente, las investigaciones llevadas a cabo en el campo de la transmisión de calor mediante termosifón, tratan de conocer el comportamiento de las distintas sustancias, con el fin de optimizar dicha tecnología para la transferencia de calor. En este sentido, en el Área de Máquinas y Motores Térmicos, perteneciente al Departamento de Ingeniería Mecánica, Energética y de Materiales de la Universidad Pública de Navarra, se está llevando a cabo un proyecto de investigación con fluidos de tra...

Multi-Temperature Heat Pump with Cascade Compressor Connection

Directory of Open Access Journals (Sweden)

Sit M.L.

2017-08-01

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.

Numerical research on the scroll compressor with refrigeration injection

International Nuclear Information System (INIS)

Wang Baolong; Shi Wenxing; Li Xianting; Yan Qisen

2008-01-01

A general model for a scroll compressor with refrigerant injection is established in this paper. The model can be used to predict the macro performance and inner compression process of the injected scroll compressor. A series of experiments are conducted to validate the accuracy of the model. The results show that the model can precisely predict not only the general performance of the compressor but also the inner compression with or without refrigerant injection. Based on the thermodynamic model and the test bench, the injection process of the scroll compressor has been investigated and the thermodynamic essence is revealed. It is found that the refrigerant injection process can be considered as a continual parameter-varying 'adiabatic throttling + isobaric mixture' time-varying process

Double throat pressure pulsation dampener for oil-free screw compressors

Science.gov (United States)

Lucas, Michael J.

2005-09-01

This paper describes a recent invention at Ingersoll-Rand for reducing the pressure pulsations in an oil-free screw compressor. Pressure pulsation is a term used in the air compressor industry to describe the rapid change in pressure with time measured in the downstream piping of the air compressor. The pulsations are due to the rapid opening and closing of the screws as the compressed air is eject from the compressor into the piping system. The pulsations are known to produce excessive noise levels and high levels of vibration in the piping system. Reducing these pulsations is critical to achieving a quiet running compressor. This paper will describe the methodology used to analyze the data and show both computational and experimental results achieved using the pulsation dampener. A patent for this design has been filed with the US patent office.

An Investigation of Backflow Phenomenon in Centrifugal Compressors

Science.gov (United States)

Benser, William A; Moses, Jason J

1945-01-01

Report presents the results of an investigation conducted to determine the nature and the extent of the reversal of flow, which occurs at the inlet of centrifugal compressors over a considerable portion of the operating range. Qualitative studies of this flow reversal were made by lampblack patterns taken on a mixed-flow-type impeller and by tuft studies made on a conventional centrifugal compressor. Quantitative studies were made on a compressor specially designed to enable survey of angularity of flow, static and total pressures, and temperatures to be taken very close to the impeller front housing.

Small Displacement, Long Life On-Orbit Compressor Design and Fabrication

Science.gov (United States)

Gerlach, C. R.; Schroeder, E. C.; Deffenbaugh, D. D.; Masetta, J. P.

1989-01-01

The focus is the generation of technology and fabrication of prototype hardware applicable to seven Space Station compressor system applications. The compressors are of the single acting reciprocating piston type and, in general, may be termed miniature in size compared with normal commercially available equipment. The initial technology development is focused on improved valve designs, and the control of pulsations and heating effects in order to increase compressor efficiency and reduce cycle temperatures, thus permitting significantly increased stage pressure ratios. The initial test compressor was successfully operated at pressure ratios of up to 50:1, and this significant extension of allowable pressure ratio will result in a reduction of the number of required stages and, hence, total hardware thereby reducing system weight and volume. These experiments have also identified the need to employ low shaft speeds, on the order of 250 to 500 rpm, to enhance heat transfer and increase life. The prototype compressor currently being designed, is to be driven by a low-speed brushless dc motor sealed in a case common to the compressor drive mechanism case. The compressor and motor case will communicate with stage suction pressure so that any minor gas leakage past the piston rings will be returned to the suction. Emphasis in this prototype design is being placed on simplicity, durability, commonality of components, and high efficiency.

Available pressure amplitude of linear compressor based on phasor triangle model

Science.gov (United States)

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

2017-12-01

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

Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

Science.gov (United States)

Knudsen, P.; Ganni, V.; Dixon, K.; Norton, R.; Creel, J.

2015-08-01

Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which may be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.

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)

2015-04-16

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.

Experimental Investigation of Diffuser Hub Injection to Improve Centrifugal Compressor Stability

Science.gov (United States)

Skoch, Gary J.

2004-01-01

Results from a series of experiments to investigate whether centrifugal compressor stability could be improved by injecting air through the diffuser hub surface are reported. The research was conducted in a 4:1 pressure ratio centrifugal compressor configured with a vane-island diffuser. Injector nozzles were located just upstream of the leading edge of the diffuser vanes. Nozzle orientations were set to produce injected streams angled at 8, 0 and +8 degrees relative to the vane mean camber line. Several injection flow rates were tested using both an external air supply and recirculation from the diffuser exit. Compressor flow range did not improve at any injection flow rate that was tested. Compressor flow range did improve slightly at zero injection due to the flow resistance created by injector openings on the hub surface. Leading edge loading and semi-vaneless space diffusion showed trends similar to those reported earlier from shroud surface experiments that did improve compressor flow range. Opposite trends are seen for hub injection cases where compressor flow range decreased. The hub injection data further explain the range improvement provided by shroud-side injection and suggest that different hub-side techniques may produce range improvement in centrifugal compressors.

Effects of casing treatment on a small, transonic axial-flow compressor

Science.gov (United States)

Holman, F. F.; Kidwell, J. R.

1975-01-01

Improved axial compressor surge margin through effective rotor casing treatment has been identified from test results on large axial compressors. A modified scale of a large compressor was built and tested to determine if similar improvements in surge margin could be duplicated in small-size turbomachinery. In addition, the effects of rotor radial running clearance, both with and without casing treatment, were investigated and are discussed. Test results of the scale configuration are presented and compared to the parent compressor.

Energy saving potential in existing industrial compressors

International Nuclear Information System (INIS)

Vittorini, Diego; Cipollone, Roberto

2016-01-01

The Compressed Air Sector accounts for a mean 10% worldwide electricity consumption, which ensures about its importance, when energy saving and CO_2 emissions reduction are in question. Since the compressors alone account for 15% overall industry electricity consumption, it appears vital to pay attention to machine performances. The paper presents an overview of present compressor technology and focuses on saving directions for screw and sliding vanes machines, according to data provided by the Compressed Air and Gas Institute and PNEUROP. Data were processed to obtain consistency with fixed reference pressures and organized as a function of main operating parameters. Each sub-term, contributing to the overall efficiency (adiabatic, volumetric, mechanical, electric, organic), was considered separately: the analysis showed that the thermodynamic improvement during compression achievable by splitting the compression in two stages, with a lower compression ratio, opens the way to significantly reduce the energy specific consumption. - Highlights: • Compressors technology overview in industrial compressed air systems. • Market compressors efficiency baseline definition. • Energy breakdown and evaluation of main efficiency terms. • Assessment of air cooling-related energy saving potential. • Energy specific consumption reduction through dual stage compression.

Computational analysis of a multistage axial compressor

Science.gov (United States)

Mamidoju, Chaithanya

Turbomachines are used extensively in Aerospace, Power Generation, and Oil & Gas Industries. Efficiency of these machines is often an important factor and has led to the continuous effort to improve the design to achieve better efficiency. The axial flow compressor is a major component in a gas turbine with the turbine's overall performance depending strongly on compressor performance. Traditional analysis of axial compressors involves throughflow calculations, isolated blade passage analysis, Quasi-3D blade-to-blade analysis, single-stage (rotor-stator) analysis, and multi-stage analysis involving larger design cycles. In the current study, the detailed flow through a 15 stage axial compressor is analyzed using a 3-D Navier Stokes CFD solver in a parallel computing environment. Methodology is described for steady state (frozen rotor stator) analysis of one blade passage per component. Various effects such as mesh type and density, boundary conditions, tip clearance and numerical issues such as turbulence model choice, advection model choice, and parallel processing performance are analyzed. A high sensitivity of the predictions to the above was found. Physical explanation to the flow features observed in the computational study are given. The total pressure rise verses mass flow rate was computed.

Screw compressor analysis from a vibration point-of-view

Science.gov (United States)

Hübel, D.; Žitek, P.

2017-09-01

Vibrations are a very typical feature of all compressors and are given great attention in the industry. The reason for this interest is primarily the negative influence that it can have on both the operating staff and the entire machine's service life. The purpose of this work is to describe the methodology of screw compressor analysis from a vibration point-of-view. This analysis is an essential part of the design of vibro-diagnostics of screw compressors with regard to their service life.

Development of throughflow calculation code for axial flow compressors

International Nuclear Information System (INIS)

Kim, Ji Hwan; Kim, Hyeun Min; No, Hee Cheon

2005-01-01

The power conversion systems of the current HTGRs are based on closed Brayton cycle and major concern is thermodynamic performance of the axial flow helium gas turbines. Particularly, the helium compressor has some unique design challenges compared to the air-breathing compressor such as high hub-to-tip ratios throughout the machine and a large number of stages due to the physical property of the helium and thermodynamic cycle. Therefore, it is necessary to develop a design and analysis code for helium compressor that can estimate the design point and off-design performance accurately. KAIST nuclear system laboratory has developed a compressor design and analysis code by means of throughflow calculation and several loss models. This paper presents the outline of the development of a throughflow calculation code and its verification results

Correct integration of compressors and expanders in above ambient heat exchanger networks

International Nuclear Information System (INIS)

Fu, Chao; Gundersen, Truls

2016-01-01

The Appropriate Placement concept (also referred to as Correct Integration) is fundamental in Pinch Analysis. The placement of reactors, distillation columns, evaporators, heat pumps and heat engines in heat exchanger networks is well established. The placement of pressure changing equipment such as compressors and expanders is complex and less discussed in literature. A major difficulty is that both heat and work (not only heat) are involved. The integration of compressors and expanders separately into heat exchanger networks was recently investigated. A set of theorems were proposed for assisting the design. The problem is even more complex when both compressors and expanders are to be integrated. An important concern is about the sequence of integration with compressors and expanders, i.e. should compressors or expanders be implemented first. This problem is studied and a new theorem is formulated related to the Correct Integration of both compressors and expanders in above ambient heat exchanger networks. The objective is to minimize exergy consumption for the integrated processes. A graphical design methodology is developed for the integration of compressors and expanders into heat exchanger networks above ambient temperature. - Highlights: • The correct integration of compressors and expanders in heat exchanger networks is studied. • A theorem is proposed for heat integration between compressors and expanders. • The total exergy consumption is minimized.

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

OpenAIRE

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

2016-01-01

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...

Centrifugal compressor efficiency improvement and its environmental impact in waste water treatment

International Nuclear Information System (INIS)

Viholainen, J.; Grönman, K.; Jaatinen-Värri, A.; Grönman, A.; Ukkonen, P.; Luoranen, M.

2015-01-01

Highlights: • Energy performance and environmental impact of the compressor operation was studied. • Diffusers can offer significant energy savings in aeration compressor tasks. • Diffusers used in compressors reduce the environmental impact of the machine use. • The influence of additional material and diffuser manufacturing is insignificant. - Abstract: Energy costs typically dominate the life-cycle costs of centrifugal compressors used in various industrial and municipal processes, making the compressor an attractive target for energy efficiency improvements. This study considers the achievable energy savings of using three different diffuser types in a centrifugal compressor supporting a typical end-use process in a waste water treatment plant. The effect of the energy efficiency improvements on the annual energy use and the environmental impacts are demonstrated with energy calculations and life-cycle assessment considering the selected compressor task in the waste water aeration. Besides the achievable energy saving benefits in the wastewater aeration process, the presented study shows the influence of the additional material needed in the diffuser manufacturing on the total greenhouse gas emissions of the compressor life-cycle. According to the calculations and assessment results, the studied diffuser types have a significant effect on the compressor energy use and environmental impacts when the compressor is operated in the aeration task. The achievable annual energy savings in this case were 2.5–4.9% in comparison with the baseline scenario. Also, the influence of the additional material and energy use for manufacturing the diffuser are insignificant compared with the avoided greenhouse gas reduction potential

Double-yoke balanced compressor

International Nuclear Information System (INIS)

Durenec, P.

1981-01-01

A double-yoke balanced compressor for a cryogenic cooler that has only linear motion imparted to balanced piston and cylinder masses. A piston yoke is driven in the linear stroke direction by a piston axially offset crankshaft cam and a cylinder yoke is driven linearly by a cylinder axially offset crankshaft cam that is exactly offset 180 0 from the other cam. A large circular bushing in the compressor housing covers the entire outer cylinder head during linear operation to prevent blow by and to guide the cylinder linearly. The lower portion of the piston and cylinder connecting rods fit into linear guides that are further comprised of low molecular weight gas filled cavities to provide additional air bearing smoothness to the linear motion of the piston and cylinder

All-optical fiber compressor

International Nuclear Information System (INIS)

Ivanov, Luben M.

2015-01-01

A simple all-optical fiber compressor, based on an idea of dispersion management using a fiber of positive dispersion in the first part and of negative dispersion in the second one at the working wavelength, is investigated. The method allows a combination of the advantages of the classic fiber-grating and of the multisoliton compression. It is possible to improve substantially the quality of the compressed pulse compared to the multisoliton compression. The compression factor could be increased up to 2-2.5 times when the fraction of the input pulse energy appearing within the compressed pulse enhances more than 2 times. Thus, the peak power of the compressed pulse is able to increase about 5 times and the quality of the obtained pulses should be comparable with those obtained by the fiber-grating compressor

Low-temperature centrifugal helium compressor

International Nuclear Information System (INIS)

Kawada, M.; Togo, S.; Akiyama, Y.; Wada, R.

1974-01-01

A centrifugal helium compressor with gas bearings, which can be operated at the temperature of liquid nitrogen, has been investigated. This compressor has the advantages that the compression ratio should be higher than the room temperature operation and that the contamination of helium could be eliminated. The outer diameter of the rotor is 112 mm. The experimental result for helium gas at low temperature shows a flow rate of 47 g/s and a compression ratio of 1.2 when the inlet pressure was 1 ata and the rotational speed 550 rev/s. The investigation is now focused on obtaining a compression ratio of 1.5. (author)

Turbine Engine with Differential Gear Driven Fan and Compressor

Science.gov (United States)

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

2013-01-01

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.

[Lubricant-free piston compressors for mechanized medical instruments].

Science.gov (United States)

Sabitov, V Kh; Repin, V A; Kil'kinov, A A

1988-01-01

Piston compressor without lubrication with air blow to packing rings by plunger, disposed in subpiston space, is recommended as the basic scheme of construction of a power supply unit for medical pneumatic tooling. The construction reduces a leak of the compressive medium, increasing the efficiency of a compressor and seal reliability.

Fisiologia do transporte de fluidos e solutos atraves da membrana peritoneal

Directory of Open Access Journals (Sweden)

Anna Rita Aguirre

2014-03-01

Full Text Available Nesta revisão, são explicados os fenômenos envolvidos nas trocas de fluidos e solutos através da membrana peritoneal, tanto na situação fisiológica quanto no contexto da diálise peritoneal. Para tanto, são utilizados os modelos matemáticos desenvolvidos para estudo do transporte pela membrana, tais como o "Modelo de Poros" e o "Modelo Distributivo". Os ganhos científicos com as pesquisas nesse campo são contemplados e as áreas que merecem pesquisas adicionais também são citadas. Assim, o estado atual do conhecimento fisiológico a respeito dessa modalidade de terapia renal substitutiva, no que se refere aos eventos relacionados à membrana peritoneal, encontra-se sintetizado nesse manuscrito.

Performance test for the compressor of 100kW APU

International Nuclear Information System (INIS)

Lim, Byeung Jun; Cha, Bong Jun; Yang, Soo Seok; Lee, Kyoung Jin; Baik, Ki Young

2001-01-01

The performance test of a centrifugal compressor for APU(Auxiliary Power Unit) which is developed by the collaborative research of KARI and Samsung TechWin has been conducted. The investigated compressor consists of a curved inlet, a centrifugal impeller, a channel diffuser and a plenum chamber. The experiments were carried out in an open-loop centrifugal compressor test rig driven by a turbine. For three different diffusers, overall performance data were obtained at 80%, 90% and 97% of design speed. For the initially designed wedge-type diffuser, test results showed that the compressor was operated at a higher mass flow rate than the design requirement. By reducing the diffuser throat area, the compressor operating range was shifted to lower mass flow rate range. The test result of redesigned wedge-type diffuser showed high pressure loss. To reduce the diffuser loss, diffuser inlet radius was increased and airfoil-type of diffuser was adopted. This airfoil-type diffuser showed reasonal results in terms of design requirement

Performance enhancement of hermetic compressor using phase change materials

Science.gov (United States)

Mahmoud, I. M.; Rady, M. A.; Huzayyin, A. S.

2015-08-01

The present study is motivated by the need for the research of simple measures for increasing energy efficiency of hermetic compressor. The measure is the application of phase change materials for performance enhancement. The first experimental study should be guide for choice of PCM. It has been performed to investigate the effects of thermostat setting temperature on the performance of hermetic compressor. The effects of thermostat setting temperature with and without load on power consumption have been analyzed. Performance enhancement using phase change materials (PCMs) has been studied by employing a phase change material Rubitherm-42 (RT-42) on the top surface of compressor. Choice of PCM material is based on basic compressor performance measured in the first part of the present study. Experiments have been carried out for different load values and different quantities of PCM. The quantity and phase change characteristic of PCM are essential parameters that determine the percentage of performance enhancement in term of energy consumption. Reduction of energy consumption of about 10% has been achieved in the present study by using PCM. The present study shows that how to reduce the electrical power consumption to enhance compressor heat dissipation method to improve efficiency.

Experiencias en el uso de la ORIMATITA® como densificante de fluidos de perforación en el Norte de Monagas, Venezuela

NARCIS (Netherlands)

Rengifo, R.; Quercia Bianchi, G.; Quiroga, F.; Chacón, O.; Ojeda, F.; Rollinson, J.; Rivers, R.; Tovar, J.G.

2004-01-01

La barita ha sido predominantemente el material densificante usado en los fluidos de perforación. Las minas de barita se encuentran ubicadas lejos de los centros de consumo, lo cual, debido al transporte, incrementa el costo final del mineral. En Venezuela, dentro de la industria petrolera nacional,

Development of Performance Analysis Program for an Axial Compressor with Meanline Analysis

International Nuclear Information System (INIS)

Park, Jun Young; Park, Moo Ryong; Choi, Bum Suk; Song, Je Wook

2009-01-01

Axial-flow compressor is one of the most important parts of gas turbine units with axial turbine and combustor. Therefore, precise prediction of performance is very important for development of new compressor or modification of existing one. Meanline analysis is a simple, fast and powerful method for performance prediction of axial-flow compressors with different geometries. So, Meanline analysis is frequently used in preliminary design stage and performance analysis for given geometry data. Much correlations for meanline analysis have been developed theoretically and experimentally for estimating various types of losses and flow deviation angle for long time. In present study, meanline analysis program was developed to estimate compressor losses, incidence angles, deviation angles, stall and surge conditions with many correlations. Performance prediction of one stage axial compressors is conducted with this meanline analysis program. The comparison between experimental and numerical results show a good agreement. This meanline analysis program can be used for various types of single stage axial-flow compressors with different geometries, as well as multistage axial-flow compressors

The New Performance Calculation Method of Fouled Axial Flow Compressor

Directory of Open Access Journals (Sweden)

Huadong Yang

2014-01-01

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.

Development of compressor equipment for technologies of hydrocarbons extraction using nitrogen

Directory of Open Access Journals (Sweden)

G. V. Kirik

2016-12-01

Full Text Available This article provides an overview of the results of research and development work aimed at the development and implementation of technologies compressor using nitrogen to extract hydrocarbons. Nitrogen as the most affordable gas, is used as a neutral environment while performing a variety of works: gas injection into wells to stabilize the reservoir pressure in the development of oil and gas fields, gas condensate production, as well as the performance of repair work and testing of pipelines. A significant role is played by the use of nitrogen for extinguishing fires in coal mines. The implementation of these technologies requires the design and development of domestic production of the compressor equipment. The article gives some examples of developments of compressor stations based on screw and piston compressors, which meet modern requirements of efficiency, reliability, ergonomics and ecology, equipped with systems of control and regulation on the basis of controllers. The description and characteristics of the compressor equipment, and some results of the implementation compressors and technologies using nitrogen as a neutral environment.

RF Energy Compressor

International Nuclear Information System (INIS)

Farkas, Z.D.

1980-02-01

The RF Energy Compressor, REC described here, transforms cw rf into periodic pulses using an energy storage cavity, ESC, whose charging is controlled by 180 0 bi-phase modulation, PSK, and external Q switching, βs. Compression efficiency, C/sub e/, of 100% can be approached at any compression factor C/sub f/

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

Science.gov (United States)

Zhao, Yuanyang; Li, Liansheng

2015-08-01

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

Centrifugal compressor tip clearance and impeller flow

Energy Technology Data Exchange (ETDEWEB)

Jaatinen-Varri, Ahti; Tiainen, Jonna; Turunen-Saaresti, Teemu; Gronman, Aki; Ameli, Alireza; Backman, Jari [Laboratory of Fluid Dynamics, LUT School of Energy Systems, Lappeenranta University of Technology, Lappeenranta (Finland); Engeda, Abraham [Turbomachinery Laboratory, Dept. of Mechanical Engineering, Michigan State University, East Lansing (United States)

2016-11-15

Compressors consume a considerable portion of the electricity used in the industrial sector. Hence, improvements in compressor efficiency lead to energy savings and reduce environmental impacts. The efficiency of an unshrouded centrifugal compressor suffers from leakage flow over the blade tips. The effect of tip leakage flow on the passage flow differs between the full and splitter blade passages. In this study, the differences in the flow fields between the full and splitter blade passages were studied numerically in detail. An industrial high-speed compressor with a design pressure ratio of 1.78 was modelled. Numerical studies were conducted with six different tip clearances and three different diffuser widths. The results show that increasing tip clearance considerably increases the reversed flow into the impeller with an unpinched diffuser. The reversed flow then partly mixes into the flow in the same blade passage it entered the impeller and the rest migrates over the blade, mixing with the tip clearance flow. Furthermore, as the reversed and clearance flow mix into the wake, the wake is weakened. As pinch reduces both the reversed flow and clearance flow, the passage wakes are stronger with pinches. However, the pinch is beneficial as the losses at the impeller outlet decrease.

Centrifugal compressor tip clearance and impeller flow

International Nuclear Information System (INIS)

Jaatinen-Varri, Ahti; Tiainen, Jonna; Turunen-Saaresti, Teemu; Gronman, Aki; Ameli, Alireza; Backman, Jari; Engeda, Abraham

2016-01-01

Compressors consume a considerable portion of the electricity used in the industrial sector. Hence, improvements in compressor efficiency lead to energy savings and reduce environmental impacts. The efficiency of an unshrouded centrifugal compressor suffers from leakage flow over the blade tips. The effect of tip leakage flow on the passage flow differs between the full and splitter blade passages. In this study, the differences in the flow fields between the full and splitter blade passages were studied numerically in detail. An industrial high-speed compressor with a design pressure ratio of 1.78 was modelled. Numerical studies were conducted with six different tip clearances and three different diffuser widths. The results show that increasing tip clearance considerably increases the reversed flow into the impeller with an unpinched diffuser. The reversed flow then partly mixes into the flow in the same blade passage it entered the impeller and the rest migrates over the blade, mixing with the tip clearance flow. Furthermore, as the reversed and clearance flow mix into the wake, the wake is weakened. As pinch reduces both the reversed flow and clearance flow, the passage wakes are stronger with pinches. However, the pinch is beneficial as the losses at the impeller outlet decrease

Design Method for Channel Diffusers of Centrifugal Compressors

Directory of Open Access Journals (Sweden)

Mykola Kalinkevych

2013-01-01

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.

Resistance Torque Based Variable Duty-Cycle Control Method for a Stage II Compressor

Science.gov (United States)

Zhong, Meipeng; Zheng, Shuiying

2017-07-01

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.

Centrifugal compressor case study

Energy Technology Data Exchange (ETDEWEB)

Eckert, B.

2010-10-15

Three centrifugal compressors at a pipeline station were retrofitted with higher head impellers in 2008. The owners of the station experienced vibration problems over the following 2 years that caused transmitter and position failures that were assumed to be flow-induced pulsations. A vibration and pulsation analysis indicated that the shell mode piping vibration excited by the blade pass pulsation was responsible for the failures. This study outlined factors that contributed to the vibration problem. Interferences between the compressor and shell mode piping natural frequencies were predicted, and potential excitation sources were examined. The study demonstrated how centrifugal vibration analyses can be used during the design phase to avoid costly adjustments. Recommendations included the addition of stiffeners to alter the shell modes, and the addition of constrained layer damping material to reduce resonant responses. 2 refs., 1 tab., 12 figs.

Centrifugal and axial compressor control

CERN Document Server

McMillan, Gregory K

2009-01-01

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.

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

International Nuclear Information System (INIS)

Jung, Mooncheong; Han, Jaeyoung; Yu, Sangseok

2016-01-01

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.

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)

2016-05-15

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.

Separation of compressor oil from helium

International Nuclear Information System (INIS)

Strauss, R.; Perrotta, K.A.

1982-01-01

Compression of helium by an oil-sealed rorary screw compressor entrains as much as 4000 parts per million by weight of liquid and vapor oil impurities in the gas. The reduction below about 0.1 ppm for cryogenic applications is discussed. Oil seperation equipment designed for compressed air must be modified significantly to produce the desired results with helium. The main differences between air and helium filtration are described. A description of the coalescers is given with the continuous coalescing of liquid mist from air or other gas illustrated. Oil vapor in helium is discussed in terms of typical compressor oils, experimental procedure for measuring oil vapor concentration, measured volatile hydrocarbons in the lubricants, and calculated concentration of oil vapor in Helium. Liquid oil contamination in helium gas can be reduced well below 0.1 ppm by a properly designed multiple state coalescing filter system containing graded efficiency filter elements. The oil vapor problem is best attached by efficiently treating the oil to remove most of the colatiles before charging the compressor

Uso de aceites esenciales extraídos por medio de fluidos supercríticos para la elaboración de alimentos funcionales

Directory of Open Access Journals (Sweden)

Angélica Esquivel F.

2007-11-01

Full Text Available El consumo de alimentos funcionales y la tendencia a productos cada vez más naturales se ha incrementado en los últimos años, dando pie a nuevas investigaciones en el campo de la obtención de aditivos que pueden generar alimentos funcionales. En esta revisión, se discutió sobre la técnica de obtención de extractos naturales conocida como extracción por medio de fluidos supercríticos, se evaluó el método de extracción, las ventajas y desventajas de este, así como las condiciones ideales de extracción de algunos compuestos naturales que se pueden utilizar como ingredientes funcionales debido a su poder antioxidante; adicionalmente, se revisó el uso que se les está dando a los compuestos extraídos por medio de fluidos supercríticos en la ciencia de alimentos.

Caracterización del tipo de cavitación mediante dinámica computacional de fluidos para posteriores aplicaciones al estudio experimental del daño por cavitación

OpenAIRE

Moll, Flavio; Manuele, Diego; Coussirat Núñez, Miguel Gustavo; Guardo Zabaleta, Alfredo de Jesús; Fontanals García, Alfred

2011-01-01

La cavitación se corresponde a una estructura bifásica (líquido-vapor) cuando la presión del líquido disminuye hasta su presión de vapor, pv. Esta disminución de pv puede deberse a diversos factores relacionados con la hidrodinámica del flujo y las propiedades físicas del fluido, pudiendo presentar diferentes características. En la cavitación hidrodinámica, pueden distinguirse efectos que pueden producir un acoplamiento fluido-estructura (lock-in) que puede favorecen la falla del material, só...

Preliminary S-CO_2 Compressor Design for Micro Modular Reactor

International Nuclear Information System (INIS)

Lee, Jekyoung; Cho, Seong Kuk; Kim, Seong Gu; Lee, Jeong Ik

2016-01-01

Due to economic benefit of S-CO_2 Brayton cycle which is came from high efficiency and compactness, active research is currently conducted by various research groups and various approaches are suggested to take benefits of S-CO_2 Brayton cycle. KAIST research team also has been working on advanced concept for application of S-CO_2 Brayton cycle to nuclear system and Micro Modular Reactor (MMR) concept was suggested. The preliminary compressor design of S-CO_2 compressor for MMR system was carried out to observe feasibility of compressor design. Preliminary S-CO_2 compressor design for MMR system was successfully conducted and some issues are discovered from the design study. From the previous work done by Cho, conceptual design for MMR system was provided. Thus, further preliminary design should be carried out to obtain feasible S-CO_2 compressor design for MMR system. KAIST_TMD which is turbomachinery in-house code for real gases including S-CO_2 is continuously updated and currently it has 3D geometry construction and design optimization capability

Study of compressor systems for a gas-generator engine

Science.gov (United States)

Sather, Bernard I; Tauschek, Max J

1950-01-01

Various methods of providing compressor-capacity and pressure-ratio control in the gas-generator type of compound engine over a range of altitudes from sea level to 50,000 feet are presented. The analytical results indicate that the best method of control is that in which the first stage of compression is carried out in a variable-speed supercharger driven by a hydraulic slip coupling. The constant-speed second stage could be either a mixed-flow rotary compressor or a piston-type compressor. A variable-area turbine nozzle is shown to be unnecessary for cruising operation of the engine.

Design, fabrication, and test plan of a small centrifugal compressor test model for a supercritical CO2 compressor in the fast reactor power plant

International Nuclear Information System (INIS)

Muto, Yasushi; Ishizuka, Takao; Aritomi, Masanori

2009-01-01

To clarify the CO 2 compressor performance in the vicinity of the critical point, a research project has begun at Tokyo Institute of Technology based on Japanese government funding. This paper describes the design and fabrication results of a small and high-speed centrifugal test compressor. Drawings of compressor structures such as an impeller and a rotor are presented. Numerical analysis results confirm that a desirable fluid flow distribution and structural integrity with respect to both the vane strength and rotor vibration can be expected. (author)

Eficiência agronômica de fertilizantes fosfatados fluidos e sólidos

Directory of Open Access Journals (Sweden)

W.B. Scivittaro

1997-09-01

Full Text Available Um experimento para avaliar a eficiência agronômica de fertilizantes fosfatados fluidos e sólidos foi desenvolvido em casa de vegetação no Centro de Energia Nuclear na Agricultura - CENA/USP, em Piracicaba (SP, de junho a outubro de 1992. Plantas de milho foram cultivadas durante 30 dias, por três cultivos sucessivos, em vasos contendo 1 kg de dois latossolos vermelho-amarelos com diferentes capacidades de retenção de fósforo. Os fosfatos na forma fluida - ácido fosfórico e suspensão coloidal 10-30-00 e sólida - fosfato monoamônico e superfosfato triplo foram aplicados no primeiro cultivo nas doses 0, 70, 140 e 210 mg kg-1 de P2O5 (0, 30,6, 61,2 e 91,8 mg kg-1 de P. Avaliaram-se os tratamentos pelo rendimento de matéria seca, pela absorção de fósforo e pelos índices: de eficiência agronômica (IEA e equivalente em superfosfato triplo (EqST. Os resultados indicaram não haver diferenças entre as fontes fosfatadas fluidas e sólidas quanto ao seu efeito sobre a produção de matéria seca e absorção de fósforo pelas plantas de milho. Entretanto, a aplicação de doses crescentes dos fosfatos aos solos promoveu aumentos significativos no rendimento de matéria seca e absorção de fósforo. Em ambos os solos, a eficiência agronômica dos fertilizantes fosfatados fluidos e sólidos foi semelhante.

Dynamic modelling and PID loop control of an oil-injected screw compressor package

Science.gov (United States)

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

2017-08-01

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.

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

Science.gov (United States)

Swan, Jeffrey A.

2000-01-01

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

Extração por fluido supercrítico

Directory of Open Access Journals (Sweden)

Aldo Adolar Maul

Full Text Available Acima de uma certa temperatura e pressão representados pelo ponto crítico, os gases não mais podem ser liquefeitos e em função do aumento da densidade passam para o que alguns consideram um estado intermediário entre o líquido e o gasoso: tornam-se "supercríticos" e podem então agir em parte como solventes. 0 dióxido de carbono em estado supercrítico pode dissolver ou incorporar a maioria das moléculas orgânicas. Já utilizado na indústria agroalimentar, está agora entrando na indústria farmacêutica. O presente trabalho tem como objetivo apresentar o atual estágio de utilização, as vantagens e desvantagens, princípios e perspectivas de aplicação da tecnologia de extração por fluidos supercríticos, principalmente dióxido de carbono , de uma maneira ampla, na obtenção de insumos farmacêuticos e fitoterápicos.

pH, sódio, potássio, cálcio, magnésio e alumínio em solos contaminados com fluido de perfuração de poços de petróleo após ensaios de lixiviação

Directory of Open Access Journals (Sweden)

Fábio Cardoso de Freitas

2015-08-01

Full Text Available Na exploração do petróleo, o uso de fluidos de perfuração é essencial para o equilíbrio da pressão entre as formações e o interior do poço, além de impedir o refluxo do reservatório de petróleo ao poço. Os fluidos também são responsáveis pela elevação dos cascalhos de perfuração à superfície. Entretanto, estes podem ser potenciais contaminantes do ambiente, uma vez que chegam à superfície impregnados de fluidos. O trabalho objetivou avaliar o pH e os teores de Na+, K+, Ca2+, Mg2+e Al3+em um Latossolo e um Planossolo submetidos a doses de fluido de perfuração, após sofrerem dois ensaios de lixiviação. Os resultados mostraram que a adição dos fluidos ao Planossolo e Latossolo nas concentrações de 4%, 8% e 16% (m/m reduziu o alumínio tóxico a zero e promoveu aumento do pH do solo, Na+, K+e Ca2+em comparação ao controle

Method and refrigerants for replacing existing refrigerants in centrifugal compressors

International Nuclear Information System (INIS)

Kopko, W.L.

1991-01-01

This patent describes a method for replacing an existing refrigerant in a centrifugal compressor. It comprises selecting a desired impeller Mach number for the centrifugal compressor; selecting a base refrigerant constituent; combining at least one additive refrigerant constituent with the base refrigerant constituent to form a replacement refrigerant having at least one physical or chemical property different from the existing refrigerant and substantially providing the desired impeller Mach number in the centrifugal compressor; and replacing the existing refrigerant with the replacement refrigerant

Deaths Due to Accidental Air Conditioner Compressor Explosion: A Case Series.

Science.gov (United States)

Behera, Chittaranjan; Bodwal, Jatin; Sikary, Asit K; Chauhan, Mohit Singh; Bijarnia, Manjul

2017-01-01

In an air-conditioning system, the compressor is a large electric pump that pressurizes the refrigerant gas as part of the process of turning it back into a liquid. The explosion of an air conditioner (AC) compressor is an uncommon event, and immediate death resulted from the blast effect is not reported in forensic literature. We report three such cases in which young AC mechanics were killed on the spot due to compressor blast, while repairing the domestic split AC unit. The autopsy findings, the circumstances leading to the explosion of the compressor, are discussed in this study. © 2016 American Academy of Forensic Sciences.

Design and test of a high pressure centrifugal compressor

International Nuclear Information System (INIS)

Choi, Jae Ho; Han, Chak Heui; Paeng, Ki Seok; Chen, Seung Bae; Kim, Yong Ryun

2005-01-01

This paper presents an aerodynamic design, flow analysis and performance test of a pressure ratio 4:1 centrifugal compressor for gas turbine engine. The compressor is made up of a centrifugal impeller, a two-stage diffuser consisted of radial and axial types. The impeller has a 45 degree backswept angle and the design running tip clearance is 5% of impeller exit height. Three-dimensional numerical analysis is performed to analyze the flows in the impeller, diffuser and deswirler considering the impeller tip clearance. Test module and rig facilities for the compressor stage performance test are designed and fabricated. The overall compressor stage performances as well as the static pressure fields on the impeller and diffuser are measured. Two diffusers of wedge and airfoil types are tested with an impeller. The calculation and test results show that flow fields downstream the deswirler at the design and off-design points are highly nonuniform and the airfoil diffuser has the better aerodynamic characteristics than those of wedge diffuser

Research on the performance of water-injection twin screw compressor

International Nuclear Information System (INIS)

Li Jianfeng; Wu Huagen; Wang Bingming; Xing Ziwen; Shu Pengcheng

2009-01-01

Due to the development of the automotive fuel cell systems, the study on water-injection twin screw compressor has been aroused again. Twin screw compressors with water injection can be used to supply the clean compressed air for the Proton Exchange Membrane (PEM) fuel cell systems. In this research, a thermodynamic model of the working process of water-injection twin screw compressor was established based on the equations of conservation of mass and energy. The effects of internal leakage and air-water heat transfer were taken into account simultaneously in the present mathematical model. The experiments of the performance of a prototype compressor operating under various conditions were conducted to verify the model. The results show that the predictions of the model are in reasonable agreement with the experimental data.

Energy saving screw compressor technology; Energiebesparende schroefcompressortechnologie

Energy Technology Data Exchange (ETDEWEB)

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

2011-03-15

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.

46 CFR 154.534 - Cargo pumps and cargo compressors.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo pumps and cargo compressors. 154.534 Section 154.534 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES... Equipment Cargo and Process Piping Systems § 154.534 Cargo pumps and cargo compressors. Cargo pumps and...

The improvement of screw compressor performance using a newly developed rotor profile

International Nuclear Information System (INIS)

Kishi, Takayuki; Nishio, Toshio; Matsui, Akira; Ino, Nobumi

1994-01-01

An oil-compression phenomenon occurs at two portions of a conventional oil injected screw compressor that degrades the isothermal efficiency of the screw compressor. Hence a new screw rotor profile and lubricant have been developed in order to avoid the above oil-compression phenomena. Mycom and Fermi National Accelerator Laboratory have measured the performance of a new Mycom compound type screw compressor 2016C using the new profile rotors and the new lubricant. In the experiments, a 33% enhancement rate in the isothermal efficiency of the new screw compressor installed in Fermilab was achieved

Tests of cold helium compressors at Fermilab

International Nuclear Information System (INIS)

Peterson, T.J.; Fuerst, J.D.

1988-01-01

Fermilab has tested two compressors for possible installation in the satellite refrigerator buildings of the Tevatron cryogenic system. Both Creare Inc. and Cryogenic Consultants Inc. have supplied units for evaluation. The Creare machine, a high speed centrifugal pump/compressor, yielded 60% adiabatic efficiency but had difficulty withstanding two-phase flow. Cryogenic Consultants provided a reciprocating unit which achieved 59% efficiency and, although lacking the operating characteristics of the turbomachine, endured throughout testing and was insensitive to two-phase flow. Test results are discussed

CFD analysis of linear compressors considering load conditions

Science.gov (United States)

Bae, Sanghyun; Oh, Wonsik

2017-08-01

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.

Air Compressor Driving with Synchronous Motors at Optimal Parameters

Directory of Open Access Journals (Sweden)

Iuliu Petrica

2010-10-01

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.

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

Science.gov (United States)

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

2015-01-01

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

Supercritical CO2 Compressor with Active Magnetic Bearing

International Nuclear Information System (INIS)

Cha, Jae Eun; Cho, Seong Kuk; Lee, JeKyoung; Lee, Jeong Ik

2016-01-01

For the stable operation of the sCO 2 integral test facility SCIEL, KAERI prepared Active Magnetic Bearing sCO 2 compressor for the 70,000RPM operation. Power generation test with AMB compressor will be finished within first half year of 2016 under supercritical state. The principal advantages of the sCO 2 Cycle are high efficiency at moderate temperature range, compact components size, simple cycle configuration, and compatibility with various heat sources. The Supercritical CO 2 Brayton Cycle Integral Experiment Loop (SCIEL) has been installed in Korea Atomic Energy Research Institute (KAERI) to develop the base technologies for the sCO 2 cycle power generation system. The operation of the SCIEL has mainly focused on sCO 2 compressor development and establishing sCO 2 system control logic

The performance test of a modified miniature rotary compressor in upright and inverted modes subjected to microgravity

International Nuclear Information System (INIS)

Ma, Rui; Wu, Yu-ting; Du, Chun-xu; Chen, Xia; Zhang, De-lou; Ma, Chong-fang

2016-01-01

Highlights: • A miniature rotary compressor by ASPEN company was modified. • The modified compressor can be employed in microgravity. • Performance of upright compressor is superior to inverted mode in most cases. • Performance curves of system with inverted compressor are obtained. • Experimental results of compressor inverted and upright are compared. - Abstract: Vapor compression heat pump is a new concept of thermal control system and refrigerator for future space use. Compressor is a key component in the vapor compression heat pump. Development of compressor capable of operating in both microgravity (10 E-6 g) and lunar (1/6 g) environments is urgently needed for space thermal control systems based on heat pump technique. In this paper, a miniature rotary compressor by ASPEN company was modified to realize acceptable compressor lubrication and oil circulation in microgravity environments. An experimental system was built up to check the performance of the modified compressor subjected to microgravity. A performances comparison of inverted compressor with upright one was made. The influences of operating parameters such as refrigerant charge, cooling water temperature as well as compressor speed on the performances of vapor compression heat pump were investigated. The results show that the modified miniature rotary compressor in inverted mode can operate stably in a long period, which indicates that the modified compressor can be employed in microgravity environments. Compressor discharge temperature increased or decreased while COP changed more obviously with cooling water temperature and speed in microgravity. In most cases, performance of the upright compressor is superior to that of the inverted one. But when the compressor speed is from 1500 rpm to 2500 rpm or the coolant temperature is between 20 and 25 degrees, the performance of inverted compressor is better. The highest discharge temperature of the inverted compressor can be as high

Research on Noise Reduction of Reed Valves of a Hermetic Refrigerator Compressor

Science.gov (United States)

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

2017-08-01

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.

Planeamiento estratégico de Ingeniería de Sistemas de Fluidos S.A.C.

OpenAIRE

Arana, Fernando; Iparraguirre, Miguel; Vásquez, Mariela

2015-01-01

La finalidad del presente trabajo de investigación es la elaboración de un plan estratégico para la empresa Ingeniería de Sistemas de Fluidos SAC para los siguientes tres años. Este plan se inicia analizando el entorno externo en el que se desempeña ISF SAC, tanto el entorno general como el entorno de la industria, de esta manera conocer las oportunidades y amenazas a las que se debe enfrentar la empresa. Una vez analizado el entorno externo, se realiza el análisis interno en el cual se evalú...

Modelica-based modeling and simulation of a twin screw compressor for heat pump applications

International Nuclear Information System (INIS)

Chamoun, Marwan; Rulliere, Romuald; Haberschill, Philippe; Peureux, Jean-Louis

2013-01-01

A new twin screw compressor has been developed by SRM (Svenska Rotor Maskiner) for use in a new high temperature heat pump using water as refrigerant. This article presents a mathematical model of the thermodynamic process of compression in twin screw compressors. Using a special discretization method, a transient twin screw compressor model has been developed using Modelica in order to study the dry compression cycle of this machine at high temperature levels. The pressure and enthalpy evolution in the control volumes of the model are calculated as a function of the rotational angle of the male rotor using energy and continuity equations. In addition, associated processes encountered in real machines such as variable fluid leakages, water injection and heat losses are modeled and implemented in the main compressor model. A comparison is performed using the model developed, demonstrating the behavior of the compressor and the evolution of its different parameters in different configurations with and without water injection. This comparison shows the need for water injection to avoid compressor failure and improve its efficiency. -- Highlights: • Difficulties related to the compressor limit the development of a high temperature heat pump using water as refrigerant. • A new water vapor double screw compressor has been developed to overcome compression problems. • A dynamic model of this compressor has been developed and simulated using Modelica. • The behavior of the compressor has been identified all along the compression cycle and efficiencies have been calculated

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

Science.gov (United States)

Kusuma, Yuriadi; Permana, Dadang S.

2018-03-01

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

FOREWORD: 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF2013)

Science.gov (United States)

Wu, Yulin; Wang, Zhengwei; Yuan, Shouqi; Shi, Weidong; Liu, Shuhong; Luo, Xingqi; Wang, Fujun

2013-12-01

; other fluid machinery and devices, such as, wind turbines, turbochargers and reversible pump-turbines, clearance and sealing, jets, filters and mixers; and their engineering application and their system behavior, especially, the application of the renewable energy of pumps, compressors, fans and blowers. The objective of the conference was to provide an opportunity for researchers, engineers and students to report on the latest developments in the fields of pumps, compressors, fans and turbochargers, as well as systems. The participants were encouraged to present their work in progress with a short lead time, and the conference promoted discussion of the problems encountered. The ICPF2013 brought together 191 scientists and researchers from 14 countries, affiliated with universities, technology centers and industrial firms to debate topics related to advanced technologies for pumps and fans, which would enhance the sustainable development of fluid machinery and fluid engineering. The Scientific Committee selected 166 technical papers on the following topics: (i) Principles of Fluid Machinery, (ii) Pumps, (iii) Compressors, Fans and Turbochargers, (iv) Turbines, (v) Cavitation and Multiphase Flow, (vi) Systems and Other Fluid Machinery, and 10 invited plenary and invited session lectures, which were presented at the conference, to be included in the proceedings. All the papers of ICPF2013, which were published in this volume of IOP Conference Series: Materials Science and Engineering, have been peer reviewed through processes administered by the editors of the ICPF2013, those are Yulin Wu, Zhengwei Wang, Shouqi Yuan, Weidong Shi, Shuhong Liu, Xingqi Luo and Fujun Wang. We sincerely hope that the 6th International Conference on Pumps and Fans with Compressors and Wind Turbines is a significant step forward in the worldwide efforts to address the present challenges facing modern fluid machines. Professor Yulin Wu Chairman of the Local Organizing Committee 6th International

Characterization and Performance Testing of Natural Gas Compressors for Residential and Commercial Applications

Science.gov (United States)

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

2017-08-01

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.

78 FR 1162 - Cardiovascular Devices; Reclassification of External Cardiac Compressor

Science.gov (United States)

2013-01-08

.... FDA-2012-N-1173] Cardiovascular Devices; Reclassification of External Cardiac Compressor AGENCY: Food... external cardiac compressors as class III requiring premarket approval. The Cardiovascular Device... on CPR and emergency cardiovascular care (Ref. 1) conclude that ``real-time CPR prompting and...

Experiments with Liquid Propellant Jet Ignition in a Ballistic Compressor

National Research Council Canada - National Science Library

Birk, Avi

1998-01-01

.... The apparatus consists of an inline ballistic compressor and LP injector. The rebound of the ballistic compressor piston was arrested, trapping 40 to 55 MPa of 750 to 8500 C argon for ignition of circular jets in a windowed test chamber...

Investigation on output capacity control strategy of variable refrigerant flow air conditioning system with multi-compressor

International Nuclear Information System (INIS)

Tu, Qiu; Zou, Deqiu; Deng, Chenmian; Zhang, Jie; Hou, Lifeng; Yang, Min; Nong, Guicai; Feng, Yuhai

2016-01-01

Highlights: • The control model of compressor output capacity has been built. • The control strategy of compressor switching has been presented. • The switching process of standard compressor has been described. • The characteristics of EER and noise have been presented. • The control strategy and model have been proved by experiments. - Abstract: A set of 14 HP variable refrigerant flow air conditioning system (VRF AC) with multi-compressor has been designed, and the output capacity control strategy of compressor(s) including the switching control model of standard compressor has been built. In the output capacity control model, a certain suction pressure is used as the pressure control target to adjust the output capacity of compressors, and a little pressure fluctuation is taken into account to amend the target pressure. Furthermore, in the compressor switching control model, the most favorable operation frequency region is determined on base of the energy efficiency characteristic and noise characteristic of the compressor. And, in order to solve the large fluctuation problem of the system running and frequent ON-OFF action of the standard compressor, the equal output capacity switching principle can be used to determine the thermo-on and thermo-off switched frequency points, and control the switching process of the compressor. Experiments demonstrate the feasibility of this control strategy to ensure the stability and reliability, improve the energy efficiency and reduce the compressor noise.

Thermodynamic properties of UF sub 6 measured with a ballistic piston compressor

Science.gov (United States)

Sterritt, D. E.; Lalos, G. T.; Schneider, R. T.

1973-01-01

From experiments performed with a ballistic piston compressor, certain thermodynamic properties of uranium hexafluoride were investigated. Difficulties presented by the nonideal processes encountered in ballistic compressors are discussed and a computer code BCCC (Ballistic Compressor Computer Code) is developed to analyze the experimental data. The BCCC unfolds the thermodynamic properties of uranium hexafluoride from the helium-uranium hexafluoride mixture used as the test gas in the ballistic compressor. The thermodynamic properties deduced include the specific heat at constant volume, the ratio of specific heats for UF6, and the viscous coupling constant of helium-uranium hexafluoride mixtures.

Part load efficiency of packaged air-cooled water chillers with inverter driven scroll compressors

International Nuclear Information System (INIS)

Cecchinato, Luca

2010-01-01

In this paper different packaged air-cooled systems, operating on scroll compressors, are experimentally analysed from the point of view of the relation between energy efficiency and actual capacity. Single compressor, double compressors and double compressors with uneven volumetric capacity units are tested. Experimental tests demonstrated that cooling capacity control by means of variation of rotational speed is an suitable solution for improving the part load efficiency of these systems. Step capacity units obtained by splitting the system volumetric capacity between two compressors are also effective solutions. Nevertheless they appear to be more efficient than single inverter driven chillers only for part load conditions lower than 60%. In the analysed cooling capacity range (25-50 kW), tandem compressors chillers with one inverter driven compressor appear the most efficient solution combining rotational speed with step capacity control. Seasonal energy efficiency ratios were obtained with prEN 14825 calculation method confirming reduced energy consumption associated to continuous and step cooling capacity control.

IEMDC IN-LINE ELECTRIC MOTOR DRIVEN COMPRESSOR

Energy Technology Data Exchange (ETDEWEB)

Michael J. Crowley; Prem N. Bansal

2004-10-01

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

Numerical analysis on centrifugal compressor with membrane type dryer

Science.gov (United States)

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

2017-09-01

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.

Decimal multiplication using compressor based-BCD to binary converter

Directory of Open Access Journals (Sweden)

Sasidhar Mukkamala

2018-02-01

Full Text Available The objective of this work is to implement a scalable decimal to binary converter from 8 to 64 bits (i.e 2-digit to 16-digit using parallel architecture. The proposed converters, along with binary coded decimal (BCD adder and binary to BCD converters, are used in parallel implementation of Urdhva Triyakbhyam (UT-based 32-bit BCD multiplier. To increase the performance, compressor circuits were used in converters and multiplier. The designed hardware circuits were verified by behavioural and post layout simulations. The implementation was carried out using Virtex-6 Field Programmable Gate Array (FPGA and Application Specific Integrated Circuit (ASIC with 90-nm technology library platforms. The results on FPGA shows that compressor based converters and multipliers produced less amount of propagation delay with a slight increase of hardware resources. In case of ASIC implementation, a compressor based converter delay is equivalent to conventional converter with a slight increase of gate count. However, the reduction of delay is evident in case of compressor based multiplier.

A cryogenic axial-centrifugal compressor for superfluid helium refrigeration

CERN Document Server

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

1997-01-01

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.

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

Directory of Open Access Journals (Sweden)

Pookongchai Kritsada

2015-01-01

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.

Study on Design Optimization of Centrifugal Compressors Considering Efficiency and Weight

International Nuclear Information System (INIS)

Lee, Younghwan; Kang, Shinhyoung; Ha, Kyunggu

2015-01-01

Various centrifugal compressors are currently used extensively in industrial fields, where the design requirements are more complicated. This makes it more difficult to determine the optimal design point of a centrifugal compressor. Traditionally, the efficiency is an important factor for optimization. In this study, the weight of the compressor was also considered. The aim of this study was to present the design tendency considering the stage efficiency and weight. In addition, this study suggested possibility of a selection of compressor design objectives at an early design stage based on the optimization results. Only a vaneless diffuser was considered in this case. The Kriging method was used with sample points from 1D design program data. The optimal points were determined in a substitute design space.

Study on Design Optimization of Centrifugal Compressors Considering Efficiency and Weight

Energy Technology Data Exchange (ETDEWEB)

Lee, Younghwan; Kang, Shinhyoung [Seoul National University, Seoul (Korea, Republic of); Ha, Kyunggu [Hyundai Motor Group, Ulsan (Korea, Republic of)

2015-04-15

Various centrifugal compressors are currently used extensively in industrial fields, where the design requirements are more complicated. This makes it more difficult to determine the optimal design point of a centrifugal compressor. Traditionally, the efficiency is an important factor for optimization. In this study, the weight of the compressor was also considered. The aim of this study was to present the design tendency considering the stage efficiency and weight. In addition, this study suggested possibility of a selection of compressor design objectives at an early design stage based on the optimization results. Only a vaneless diffuser was considered in this case. The Kriging method was used with sample points from 1D design program data. The optimal points were determined in a substitute design space.

Reliability and Maintainability Analysis of a High Air Pressure Compressor Facility

Science.gov (United States)

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

2013-01-01

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

Compensating effect of the coherent synchrotron radiation in bunch compressors

Science.gov (United States)

Jing, Yichao; Hao, Yue; Litvinenko, Vladimir N.

2013-06-01

Typical bunch compression for a high-gain free-electron laser (FEL) requires a large compression ratio. Frequently, this compression is distributed in multiple stages along the beam transport line. However, for a high-gain FEL driven by an energy recovery linac (ERL), compression must be accomplished in a single strong compressor located at the beam line’s end; otherwise the electron beam would be affected severely by coherent synchrotron radiation (CSR) in the ERL’s arcs. In such a scheme, the CSR originating from the strong compressors could greatly degrade the quality of the electron beam. In this paper, we present our design for a bunch compressor that will limit the effect of CSR on the e-beam’s quality. We discuss our findings from a study of such a compressor, and detail its potential for an FEL driven by a multipass ERL developed for the electron-Relativistic Heavy Ion Collider.

Control and data acquisition system for rotary compressor

Directory of Open Access Journals (Sweden)

Buczaj Marcin

2017-01-01

Full Text Available The rotary compressor (crimping machine is a machine designed for making hollow forgings. The rotary compressor is a prototype device designed and built at the Technical University of Lublin. The compressor is dedicated to perform laboratory tests related to the hollow forgings of various shapes using different materials. Since the rotary compressor is an experimental device, there is no control and acquisition data system available. The article presents the concept and the capabilities of the computer control and data acquisition system supporting rotary compressing process. The main task of software system is acquisition of force and kinetic parameters related to the analysed process of the rotary forging compression. The software allows the user to declare the course of the forming forgings. This system allows current recording and analysis of four physical values: feed rate (speed of working head movement, hydraulic oil pressure at inlet and outlet of hydraulic cylinder and the torque of engine. Application functions can be divided into three groups: the configuration of the pressing process, the acquisition and analysis of data from the pressing process and the recording and presentation of stored results. The article contains a detailed description about hardware and software implementation of mentioned functions.

Techno-Economic Analysis of Gas Turbine Compressor Washing to Combat Fouling

OpenAIRE

Abass, Kabir Oliade

2015-01-01

Among the major deterioration problems a gas turbine encountered while in operation is compressor blade fouling. This is the accumulation and adhesion of dirt and sediment on the compressor blade which contributes between 70 to 85% of gas turbine performance loss. Fouling reduces turbine air mass flow capacity, compressor pressure ratio and overall gas turbine efficiency. In most cases, its effect does not manifest immediately in gas turbine power output and efficiency since they are not meas...

Virtual Refrigerant Mass Flow and Power Sensors for Variable-Speed Compressors

OpenAIRE

Kim, Woohyun; Braun, James E.

2012-01-01

The use of variable-speed compressors in heat pumps and air conditioners has increased in recent years in order to improve comfort and energy efficiency. At the same time, there is a trend towards embedding more sensors in this type of equipment to facilitate real-time energy monitoring and diagnostics. Although compressor mass flow rate and power consumption are useful indices for performance monitoring and diagnostics, they are expensive to measure. The virtual variable-speed compressor sen...

Computational analysis of supercritical carbon dioxide flow around a turbine and compressor BLADE

International Nuclear Information System (INIS)

Kim, Tae W.; Kim, Nam H.; Suh, Kune Y.; Kim, Seung O.

2007-01-01

The turbine and compressor isentropic efficiencies are one of the major parameters affecting the overall Brayton cycle efficiency. Thus, the optimal turbine and compressor design should contribute to the economics of future nuclear fission and fusion energy systems. A computation analysis was performed utilizing CFX for the supercritical carbon dioxide (SCO 2 ) flow around a turbine and compressor blade to check on the potential efficiency of the turbine and compressor which determine such basic design values as the blade (or impeller) and nozzle (or diffuser) types, blade height, and minimum and maximum radii of the hub and tip. Basic design values of the turbine and compressor blades based on the Argonne National Laboratory (ANL) design code was generated by ANSYS BladeGen TM . The boundary conditions were based on the KALIMER-600 secondary loop. Optimal SCO 2 turbine and compressor blades were developed for high efficiency of 90% by the computational analysis. (author)

Comparison of heat transfer models for reciprocating compressor

International Nuclear Information System (INIS)

Tuhovcak, J.; Hejcik, J.; Jicha, M.

2016-01-01

Highlights: • Comparison of integral heat transfer models. • Influence of heat transfer model on volumetric and isentropic efficiency. • Various gases used as working fluid. - Abstract: One of the main factors affecting the efficiency of reciprocating compressor is heat transfer inside the cylinder. An analysis of heat transfer could be done using numerical models or integral correlations developed mainly from approaches used in combustion engines; however their accuracy is not completely verified due to the complicated experimental set up. The goal of this paper is to analyse the effect of heat transfer on compressor efficiency. Various integral correlations were compared for different compressor settings and fluids. CoolProp library was used in the code to obtain the properties of common coolants and gases. A comparison was done using the in-house code developed in Matlab, based on 1st Law of Thermodynamics.

Active compressor engine silencer reduces exhaust noise

International Nuclear Information System (INIS)

Denenberg, J.N.; Miller, S.K.; Jay, M.A.

1994-01-01

An active industrial silencer on a compressor engine at a Tenneco Gas station has reduced low-frequency 'rumbling' noise by 8 dB during trials while lowering backpressure about 90$. This 8 dB reduction of the piston firing frequency corresponds to a more than 80% decrease in emitted acoustic power. The silencing unit, installed on one of six engines at the station near Eden, N.Y., continues in operation. Based on the results, the manufacturer is identifying additional compressor sites for further tests. This paper reviews this project

Centrifugal compressor design options for small turbochargers

Energy Technology Data Exchange (ETDEWEB)

Rodgers, C. [ITC, San Diego (United States)

1998-07-01

Evolutionary development of the small turbocharger centrifugal compressor over the past four decades has resulted in a finely honed turbomachinery component satisfying both thermodynamic and economic constraints. At this penultimate stage of development an appraisal was considered timely of the remaining design options that exist to enhance the performance characteristics and cost reduction features. This paper presents the results of an analytical study of various small centrifugal compressor design options, assessed in merit of both aerodynamic and manufacturing cost attributes, together with recommendations for future research avenues. (author)

Analysis of ideal sorption compressor cycles operating with gas mixtures

NARCIS (Netherlands)

Tzabar, N.; ter Brake, H.J.M.

2018-01-01

Sorption-based compressors are thermally driven and because of the absence of moving parts they are vibration free, and have the potential for long life. Sorption-based compressors have been reported to operate Joule–Thomson (JT) cryogenic coolers with pure working fluids. However, using mixed

Determination of the oil distribution in a hermetic compressor using numerical simulation

Science.gov (United States)

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

2017-08-01

In addition to the reduction of friction the oil in a hermetic compressor is very important for the transfer of heat from hot parts to the compressor shell. The simulation of the oil distribution in a hermetic reciprocating compressor for refrigeration application is shown in the present work. Using the commercial Computational Fluid Dynamics (CFD) software ANSYS Fluent, the oil flow inside the compressor shell from the oil pump outlet to the oil sump is calculated. A comprehensive overview of the used models and the boundary conditions is given. After reaching steady-state conditions the oil covered surfaces are analysed concerning heat transfer coefficients. The gained heat transfer coefficients are used as input parameters for a thermal model of a hermetic compressor. An increase in accuracy of the thermal model with the simulated heat transfer coefficients compared to values from literature is shown by model validation with experimental data.

ESTUDO TERMODINÂMICO DA APLICAÇÃO DE HIDROCARBONETOS EM SISTEMA DE REFRIGERAÇÃO

Directory of Open Access Journals (Sweden)

Jucélio Gomes da Silva

2010-11-01

Full Text Available Os esforços de pesquisa e desenvolvimento na área de Refrigeração e Ar-Condicionado aplicados ao uso de fluidos refrigerantes naturais não esta associada somente à necessidade de preservação do meio-ambiente em si, mas também apresenta grande importância na necessidade latente do aumento da eficiência energética dos equipamentos. Neste sentido, o presente trabalho trata da avaliação termodinâmica da aplicação de fluidos refrigerantes hidrocarbonetos em um sistema de refrigeração residencial que utiliza o HFC134a como fluido de trabalho. Uma análise teórico-computacional foi desenvolvida para o R134a, propano (R290 e as misturas selecionadas (R290/R600a 60%/40%, R290/R600a/R134a 40%/30%/30% e R600a/R290-GLP 70%/30% no ciclo de refrigeração padrão ASHRAE, utilizando as propriedades termodinâmicas e termofísicas fornecidas pelo software REFPROP 6.0. Os resultados das simulações computacionais foram comparados entre os fluidos para indicação da melhor alternativa ao HFC134a. Neste sentido, pôde-se observar que os hidrocarbonetos reduzem os níveis de pressão no condensador e evaporador, além de menores trabalhos de compressão serem necessários no sistema devido às propriedades termofísicas privilegiadas destes fluidos. A utilização destes fluidos também proporciona uma menor temperatura de descarga do compressor, incrementando a vida útil deste componente de alto valor do sistema.

Step on the gas : Calgary-based firm increases efficiency of compressor fleets

Energy Technology Data Exchange (ETDEWEB)

Cope, G.

2005-11-01

Many operators are reluctant to run their compressors close to optimum efficiency due to concerns that a frozen well or other problems will push units over their limit, and gas limited areas also cause the machines to be run at partial capacity. This article suggested that the key to compressor optimization lies in the correct identification of deficiencies. Petroleum companies gather thousands of compressor data points every day, ranging from temperature and pressure to control valve position and compressor volume flow, but there is no easy way of analyzing the information. A software prototype called Production Equipment Performance Reporting (PEPR) is capable of disseminating log data and model compressor performance, as well as reporting results for an entire fleet. Raw operating data is gathered for the entire fleet and compressor utilization is ranked to show which compressors are being used efficiently and which ones are lagging. Data is processed from selected points per unit and then divided into key performance indicators (KPI), such as power utilization. To experienced operators, KPIs offer concise information and a range of changes they can make to improve the efficiency of their fleets. It was noted that Devon ran PEPR at one of its major gas fields, and was so satisfied with the results that it has now applied the system to the company's entire fleet. PEPR Inc. was formed in August 2004 to commercially market the production optimization software. In addition to optimizing compressor utilization, the software also handles other important functions, such as asset management, as well as generating downtime reports. While it only takes a day to install the software and a day to train, documenting basic data for each compressor can take several months for a large fleet. It was concluded that PEPR plans to configure its software to other production-related equipment. The system is capable of using operating parameters to calculate emissions instead of

Modulation method of scroll compressor based on suction gas bypass

International Nuclear Information System (INIS)

Wang Baolong; Han Linjun; Shi Wenxing; Li Xianting

2012-01-01

The air conditioners and heat pumps tend to work in much mild environments and part load situations rather than provide the rated full capacity under severe rated testing conditions. Both the capacity and inner compression ratio of the compressor should be regulated according to the working condition for higher energy efficiency and occupants’ comfort. A potential modulating technology of the scroll compressor, suction gas bypass, is investigated in this paper. The principle and operation method are illuminated and the adaptability is validated by experiments and simulations. As a conclusion, an appropriate suction gas bypass can reduce the inner compression loss of the scroll compressor under over compression conditions, enhance the system COP and also largely decrease the heating/cooling capacity of the refrigeration/heat pump system. - Highlights: ► Suction gas bypass (SGB) is an effective regulating method of scroll compressor. ► SGB reduces the inner compression loss under over compression conditions. ► SGB largely decreases the heating/cooling capacity of the refrigeration system.

Study on flow fields in high specific speed centrifugal compressor with unpinched vaneless diffuser

International Nuclear Information System (INIS)

Tamaki, Hideaki

2013-01-01

Performance of centrifugal compressors strongly depends on their internal flow fields. CFD has become indispensable tool for getting the information about flow fields in centrifugal compressors. CFD codes are usually validated by some representative data or compared with calculated results by other CFD codes, in order to ensure their accuracies. However, learning their accuracies for all types of centrifugal compressor's specifications requires continuous works that compare experimental data obtained in developmental processes of various types of centrifugal compressors with CFD results. A prediction of a performance and a flow field of a centrifugal compressor by CFD is relatively accurate when the impact of separation and secondary flow on that flow field is weak, i.e. near design condition. Centrifugal compressors are deemed to have a wide operating range alongside high efficiencies at design points. Hence the prediction accuracy of CFD at off design conditions, where the impacts of separation and secondary flow on the flow field are strong, is critical for the design of the centrifugal compressors. This study therefore investigated the prediction accuracy of CFD using a centrifugal compressor whose geometry was intentionally changed to have a distorted flow field over a whole operating range, i.e. from choke to surge.

Study on flow fields in high specific speed centrifugal compressor with unpinched vaneless diffuser

Energy Technology Data Exchange (ETDEWEB)

Tamaki, Hideaki [IHI Corporation, Yokoham (Japan)

2013-06-15

Performance of centrifugal compressors strongly depends on their internal flow fields. CFD has become indispensable tool for getting the information about flow fields in centrifugal compressors. CFD codes are usually validated by some representative data or compared with calculated results by other CFD codes, in order to ensure their accuracies. However, learning their accuracies for all types of centrifugal compressor's specifications requires continuous works that compare experimental data obtained in developmental processes of various types of centrifugal compressors with CFD results. A prediction of a performance and a flow field of a centrifugal compressor by CFD is relatively accurate when the impact of separation and secondary flow on that flow field is weak, i.e. near design condition. Centrifugal compressors are deemed to have a wide operating range alongside high efficiencies at design points. Hence the prediction accuracy of CFD at off design conditions, where the impacts of separation and secondary flow on the flow field are strong, is critical for the design of the centrifugal compressors. This study therefore investigated the prediction accuracy of CFD using a centrifugal compressor whose geometry was intentionally changed to have a distorted flow field over a whole operating range, i.e. from choke to surge.

Fast 4-2 Compressor of Booth Multiplier Circuits for High-Speed RISC Processor

Science.gov (United States)

Yuan, S. C.

2008-11-01

We use different XOR circuits to optimize the XOR structure 4-2 compressor, and design the transmission gates(TG) 4-2 compressor use single to dual rail circuit configurations. The maximum propagation delay, the power consumption and the layout area of the designed 4-2 compressors are simulated with 0.35μm and 0.25μm CMOS process parameters and compared with results of the synthesized 4-2 circuits, and show that the designed 4-2 compressors are faster and area smaller than the synthesized one.

Numerical investigation of refrigeration machine compressor operation considering single-phase electric motor dynamic characteristics

Science.gov (United States)

Baidak, Y.; Smyk, V.

2017-08-01

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.

Performance prediction of rotary compressor with hydrocarbon refrigerant mixtures

Energy Technology Data Exchange (ETDEWEB)

Park, M.W.; Chung, Y.G. [Hanyang University Graduate School, Seoul (Korea); Park, K.W. [LG Industrial System Corporation Limited (Korea); Park, H.Y. [Hanyang University, Seoul (Korea)

1999-04-01

This paper presents the modeling approach that can be predicted transient behavior of rotary compressor. Mass and energy conservation laws are applied to the control volume, and real gas state equation is used to obtain thermodynamic properties of refrigerant. The valve equation is solved to analyze discharge process also. Dynamic analysis of vane and roller is carried out to gain friction work. From above modeling, the performance of rotary compressor with radial clearance and friction loss is investigated numerically. The performance of each refrigerant and the possibility of using the hydrocarbon refrigerant mixtures in an existing rotary compressor are estimated by applying R12, R134a, R290/R600a mixture also. (author). 6 refs., 13 figs., 1 tab.

Internal combustion engine for natural gas compressor operation

Energy Technology Data Exchange (ETDEWEB)

Hagen, Christopher; Babbitt, Guy

2016-12-27

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.

Thermodynamic and aerodynamic meanline analysis of wet compression in a centrifugal compressor

International Nuclear Information System (INIS)

Kang, Jeong Seek; Cha, Bong Jun; Yang, Soo Seok

2006-01-01

Wet compression means the injection of water droplets into the compressor of gas turbines. This method decreases the compression work and increases the turbine output by decreasing the compressor exit temperature through the evaporation of water droplets inside the compressor. Researches on wet compression, up to now, have been focused on the thermodynamic analysis of wet compression where the decrease in exit flow temperature and compression work is demonstrated. This paper provides thermodynamic and aerodynamic analysis on wet compression in a centrifugal compressor for a microturbine. The meanline dry compression performance analysis of centrifugal compressor is coupled with the thermodynamic equation of wet compression to get the meanline performance of wet compression. The most influencing parameter in the analysis is the evaporative rate of water droplets. It is found that the impeller exit flow temperature and compression work decreases as the evaporative rate increases. And the exit flow angle decreases as the evaporative rate increases

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

2007-07-01

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.)

Performance Characteristics of a 4 × 6 Oil-Free Twin-Screw Compressor

Directory of Open Access Journals (Sweden)

Sun-Seok Byeon

2017-07-01

Full Text Available The screw compressor in the early stage of development is generally known as the oil-injection type. However, escalating environmental problems and advances in electronic components have spurred continuous R & D to minimize the oil content in compressed air. The oil-free twin-screw compressor is continuously compressed by inner volumetric change between rotors and casing. For this reason, in order to predict the overall performance of the screw compressor at the early stage of the design process, industry still relies on the empirical method. However, it is difficult using the existing empirical method to gain more information of the inner fluid flow of the twin-screw compressor. Flow simulation techniques using CFD are required. This study presents applications of a recently proposed overset grid method to the solution of the flow around a moving boundary. In order to analyze the performance of a 4 × 6 oil-free screw compressor, the 3-D, unsteady and compressible flow fields were numerically calculated with a shear stress transport (SST turbulence model, and implemented by the commercial software, Star-CCM+. The pressure distributions were calculated and graphically depicted. Results also showed that the volumetric and adiabatic efficiencies of the screw compressor measured by the experiments were 78% and 71%, respectively.

A CFD study of Screw Compressor Motor Cooling Analysis

Science.gov (United States)

Branch, S.

2017-08-01

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.

Maintenance problems on reciprocating compressors [Paper No.: VA-3

International Nuclear Information System (INIS)

Lakshminarayan, S.

1981-01-01

The Heavy Water Plant at Baroda has a number of reciprocting compressors for handling synthesis gas, refrigeration ammonia and air for instrumentation. As these compressors are running continuously, their parts are subjected to wear and tear. Problems generally come up in bearings, valves, stuffing box packings, piston rings and similar such components. These problems and methods of tackling them are discussed. (M.G.B.)

The design and development of an oil-free compressor for Spacelab Refrigerator/Freezer

Science.gov (United States)

Hye, A.

1984-01-01

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.

Modelling and Experimental Investigation of Unsteady Behaviour of a Screw Compressor Plant

OpenAIRE

Chukanova, Ekatarina; Stosic, Nikola; Kovacevic, Ahmed

2014-01-01

Majority of air compressor plants installed worldwide operate permanently under unsteady conditions, however, there is still a lack of published papers which describe the plant dynamics and offer quantification parameters of the phenomenon. An experimental and analytical study of a screw compressor operation under unsteady conditions has been carried out. For this purpose a one dimensional model of the processes within a screw compressor based on the differential equations of conservation of ...

Mathematical modeling of the working cycle of oil injected rotary twin screw compressor

Energy Technology Data Exchange (ETDEWEB)

Seshaiah, N. [Cryogenics and Gas dynamics Laboratory, Department of Mechanical Engineering, National Institute of Technology, Sector-2, NIT Campus, Rourkela 769008, Orissa (India)]. E-mail: seshuet@yahoo.com; Ghosh, Subrata Kr. [Cryogenics and Gas dynamics Laboratory, Department of Mechanical Engineering, National Institute of Technology, Sector-2, NIT Campus, Rourkela 769008, Orissa (India); Sahoo, R.K. [Cryogenics and Gas dynamics Laboratory, Department of Mechanical Engineering, National Institute of Technology, Sector-2, NIT Campus, Rourkela 769008, Orissa (India); Sarangi, Sunil Kr. [Cryogenics and Gas dynamics Laboratory, Department of Mechanical Engineering, National Institute of Technology, Sector-2, NIT Campus, Rourkela 769008, Orissa (India)

2007-01-15

Oil injected twin-screw air and gas compressors are widely used for medium pressure applications in many industries. Low cost air compressors can be adopted for compression of helium and special gases, leading to significant cost saving. Mathematical analysis of oil injected twin-screw compressor is carried out on the basis of the laws of perfect gas and standard thermodynamic relations. Heat transfer coefficient required for computer simulation is experimentally obtained and used in performance prediction, when the working medium being air or helium. A mathematical model has been developed for calculating the compressor performance and for validating the results with experimental data. The flow coefficients required for numerical simulation to calculate leakage flow rates are obtained from efficiency verses clearance curves. Effect of some of the compressor operating and design parameters on power and volumetric efficiencies have been analyzed and presented.

Mathematical modeling of the working cycle of oil injected rotary twin screw compressor

International Nuclear Information System (INIS)

Seshaiah, N.; Ghosh, Subrata Kr.; Sahoo, R.K.; Sarangi, Sunil Kr.

2007-01-01

Oil injected twin-screw air and gas compressors are widely used for medium pressure applications in many industries. Low cost air compressors can be adopted for compression of helium and special gases, leading to significant cost saving. Mathematical analysis of oil injected twin-screw compressor is carried out on the basis of the laws of perfect gas and standard thermodynamic relations. Heat transfer coefficient required for computer simulation is experimentally obtained and used in performance prediction, when the working medium being air or helium. A mathematical model has been developed for calculating the compressor performance and for validating the results with experimental data. The flow coefficients required for numerical simulation to calculate leakage flow rates are obtained from efficiency verses clearance curves. Effect of some of the compressor operating and design parameters on power and volumetric efficiencies have been analyzed and presented

Comparative Study of Unsteady Flows in a Transonic Centrifugal Compressor with Vaneless and Vaned Diffusers

Directory of Open Access Journals (Sweden)

Cui Michael M.

2005-01-01

Full Text Available To reduce vibration and noise level, the impeller and diffuser blade numbers inside an industrial compressor are typically chosen without common divisors. The shapes of volutes or collectors in these compressors are also not axis-symmetric. When impeller blades pass these asymmetric structures, the flow field in the compressor is time-dependent and three-dimensional. To obtain a fundamental physical understanding of these three-dimensional unsteady flow fields and assess their impact on the compressor performance, the flow field inside the compressors needs to be studied as a whole to include asymmetric and unsteady interaction between the compressor components. In the current study, a unified three-dimensional numerical model was built for a transonic centrifugal compressor including impeller, diffusers, and volute. HFC 134a was used as the working fluid. The thermodynamic and transport properties of the refrigerant gas were modeled by the Martin-Hou equation of state and power laws, respectively. The three-dimensional unsteady flow field was simulated with a Navier-Stokes solver using the k−ϵ turbulent model. The overall performance parameters are obtained by integrating the field quantities. Both the unsteady flow field and the overall performance are analyzed comparatively for each component. The compressor was tested in a water chiller system instrumented to obtain both the overall performance data and local flow-field quantities. The experimental and numerical results agree well. The correlation between the overall compressor performance and local flow-field quantities is defined. The methodology developed and data obtained in these studies can be applied to the centrifugal compressor design and optimization.

Determination of a suitable set of loss models for centrifugal compressor performance prediction

Directory of Open Access Journals (Sweden)

Elkin I. GUTIÉRREZ VELÁSQUEZ

2017-10-01

Full Text Available Performance prediction in preliminary design stages of several turbomachinery components is a critical task in order to bring the design processes of these devices to a successful conclusion. In this paper, a review and analysis of the major loss mechanisms and loss models, used to determine the efficiency of a single stage centrifugal compressor, and a subsequent examination to determine an appropriate loss correlation set for estimating the isentropic efficiency in preliminary design stages of centrifugal compressors, were developed. Several semi-empirical correlations, commonly used to predict the efficiency of centrifugal compressors, were implemented in FORTRAN code and then were compared with experimental results in order to establish a loss correlation set to determine, with good approximation, the isentropic efficiency of single stage compressor. The aim of this study is to provide a suitable loss correlation set for determining the isentropic efficiency of a single stage centrifugal compressor, because, with a large amount of loss mechanisms and correlations available in the literature, it is difficult to ascertain how many and which correlations to employ for the correct prediction of the efficiency in the preliminary stage design of a centrifugal compressor. As a result of this study, a set of correlations composed by nine loss mechanisms for single stage centrifugal compressors, conformed by a rotor and a diffuser, are specified.

Design, Test, and Evaluation of a Transonic Axial Compressor Rotor with Splitter Blades

Science.gov (United States)

2013-09-01

INTRODUCTION A. MOTIVATION Over the course of turbomachinery history splitter vanes have been used extensively in centrifugal compressors . Axial...TEST, AND EVALUATION OF A TRANSONIC AXIAL COMPRESSOR ROTOR WITH SPLITTER BLADES by Scott Drayton September 2013 Dissertation Co...AXIAL COMPRESSOR ROTOR WITH SPLITTER BLADES 5. FUNDING NUMBERS 6. AUTHOR(S) Scott Drayton 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES

Performance Characteristics of a 4 × 6 Oil-Free Twin-Screw Compressor

OpenAIRE

Sun-Seok Byeon; Jae-Young Lee; Youn-Jea Kim

2017-01-01

The screw compressor in the early stage of development is generally known as the oil-injection type. However, escalating environmental problems and advances in electronic components have spurred continuous R & D to minimize the oil content in compressed air. The oil-free twin-screw compressor is continuously compressed by inner volumetric change between rotors and casing. For this reason, in order to predict the overall performance of the screw compressor at the early stage of the design ...

Hyper dispersion pulse compressor for chirped pulse amplification systems

Science.gov (United States)

Barty, Christopher P. J.

2011-11-29

A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.

Experimental Study on Noise Characteristic of Centrifugal Compressor Surge

OpenAIRE

Yang, Qichao; Zhao, Yuanyang; SHU, Yue; LI, Xiaosa; LI, Liansheng

2016-01-01

The centrifugal air compressor test rig is was designed and established. The experimental study was carried out on the surge characteristics of centrifugal compressor including the pressure in the pipe and the noise characteristics under different rotation speed. The tested results showed that both the suction pressure and discharge pressure fluctuation increase under surge condition and the amplitude of discharge pressure fluctuation is significantly higher than that of suction pressure. In ...

Satellite refrigerator compressors with the oil and moisture removal systems

International Nuclear Information System (INIS)

Satti, J.A.

1983-08-01

There are twenty-eight compressors installed around the Main Accelerator Ring in seven locations. Drawing 9140-ME-129720 shows the piping and the components schematic for four Mycom compressor skids per building with each having an independent oil and moisture removal system. The Mycom skids each consist of an oil injected screw compressor of 750 SCFM capacity with a 350 hp motor, oil pump, oil cooler, and oil separator. Helium gas returning from the heat exchanger train is compressed from 1 atm to 20 atm in the compressor. The compressed gas is then passed through the three coalescer de-mister where oil mist is separated from the helium gas. The helium gas then flows through the charcoal adsorber and molecular sieve where any residual oil vapor and water vapor are removed. The final stage of purification is the final filter which removes any remaining particulates from the compressed helium gas. The end product of this system is compressed and purified helium gas ready to be cooled down to cryogenic temperatures

Compressor Foundation Analysis Tool(COFANTO)

NARCIS (Netherlands)

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

2012-01-01

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

Heat flows in piston compressors

NARCIS (Netherlands)

Lekic, U.; Kok, J.B.W.; van der Meer, T.H.; van Steenhoven, A.A.; Stoffels, G.G.M.

2008-01-01

Piston compressors are widely used in today's engineering applications. Among the most important applications is however the compression of thermal carrier gas in Rankine and Stirling refrigeration cycles. Fluids used in these cycles are commonly Ammonia and Helium. In order to improve the design

Vibration signature analysis of compressors in the gaseous diffusion process for uranium enrichment

International Nuclear Information System (INIS)

Harbarger, W.B.

1975-01-01

Continuous operation of several thousand axial-flow and centrifugal compressors is vital to the gaseous diffusion process for uranium enrichment. Vibration signature analysis using a minicomputer-based Fast Fourier Transform Analyzer is being applied to the evaluation and surveillance of compressor performance at the Portsmouth Gaseous Diffusion Plant. Three areas of application include: (1) new blade design and prototype compressor evaluation; (2) corrective and preventive maintenance of machinery components; and (3) evaluation of machinery health. The present system is being used to monitor signals from accelerometers mounted on the load-bearing housings of 16 on-line compressors. These signals are transmitted by hard-wire to the analyzer for daily monitoring. A program for expansion of this system to monitor more than a thousand compressors and automation of the signature comparison process is planned for all three gaseous diffusion plants operated for the United States Energy Research and Development Administration. (auth)

The analysis on centrifugal compressor rotating stall

International Nuclear Information System (INIS)

Kim, Ji Hwan; Kim, Kwang Ho; Shin, You Hwan

2003-01-01

In the present study, the performance characteristics and the number of stall cell during rotating stall of a centrifugal air compressor were experimentally investigated. Rotating stall in the vaneless diffuser were investigated by measuring unsteady pressure fluctuations at several different diffuser radius using a high frequency pressure transducer. The number of stall cell and their rotational speeds are distinctive features of the rotating stall phenomenon. The present study is mainly forced on the analysis for the stall cell number and its propagation speed unstable operating region of the compressor. The interpretation method of visualization is based on the pressure distribution in the circumference pressure fields while plotting the pressure and its harmonics variations in time in polar coordinates. To obtain the visualize the existence rotating stall, auto-correlation function and the frequency spectra of the pressure fluctuations were measured at r/r2=1.52. When the flow coefficient is lower than 0.150, the static pressure at impeller inlet is higher than that at inlet duct of the compressor. And the flow coefficient is lower than 0.086, several stall cell groups of discrete frequencies are observed

Performance improvement of standard turbo-compressor; Han`yo turbo asshukuki no seino kaizen

Energy Technology Data Exchange (ETDEWEB)

Hokari, T.; Hasegawa, K.; Ozaki, S.; Majima, K. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

1999-05-01

Abradable materials are soft and cause no contact damage to the impeller of the turbo-compressor. Using such materials for the inlet casing facing to the impeller allows very small clearances between the impeller and inlet casing, thus improving the compressor efficiency by 10% over conventional types. Changing the area of abradable material applied to the inlet casing identified the optimum area in which decrease of the compressor surge margin is minimized and efficiency is improved by 10%. As a result, turbo-compressors have the best performance when the abradable materials are applied from the impeller outlet to two-thirds of the forward location of the inlet casing. (author)

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 ...

DEVELOPMENT OF A LINEAR COMPRESSOR FOR AIR CONDITIONERS AND HEAT PUMPS

Science.gov (United States)

The report discusses the design, building, testing, and delivering to the Environmental Protection Agency of a linear compressor for operation in a 3.0- ton (10.5 kW) residential air-conditioning and heat pumping system. The compressor design evolved from a linear resonant piston...

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

2012-12-15

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.)

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

International Nuclear Information System (INIS)

Huang, F.H.

1994-01-01

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

40 CFR 65.112 - Standards: Compressors.

Science.gov (United States)

2010-07-01

... the compressor stuffing box pressure at all times (except during periods of start-up, shutdown, or... process stream. (c) Barrier fluid system. The barrier fluid shall not be in light liquid service. Each...

Mode change design for capacity modulation in reciprocating compressor

International Nuclear Information System (INIS)

Bae, Young Ju; Kim, Jin Kook; Kim, Jong Bong; Chang, Young June

2008-01-01

Due to environmental issues, the development of low energy consumption products has become one of the main topics in the home appliance industry. The energy consumption of a refrigerator depends on the efficiency of its compressor as well as on the refrigerator cycle design, such as the capacity modulation. This study features the design of a novel capacity modulation reciprocating compressor, i.e., two-step capacity modulation (TCM). In a TCM compressor, capacity modulation is achieved by changing the dead volume in the cylinder. Instead of a concentric sleeve, an eccentric sleeve is used to change the dead volume for the clockwise and counterclockwise rotation of a motor. For stable capacity modulation, a new latching system with a key, a spring, and an eccentric sleeve is introduced, and the mode change reliability is verified by dynamic analysis

Supercritical CO{sub 2} Compressor with Active Magnetic Bearing

Energy Technology Data Exchange (ETDEWEB)

Cha, Jae Eun [KAERI, Daejeon (Korea, Republic of); Cho, Seong Kuk; Lee, JeKyoung; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

2016-05-15

For the stable operation of the sCO{sub 2} integral test facility SCIEL, KAERI prepared Active Magnetic Bearing sCO{sub 2} compressor for the 70,000RPM operation. Power generation test with AMB compressor will be finished within first half year of 2016 under supercritical state. The principal advantages of the sCO{sub 2} Cycle are high efficiency at moderate temperature range, compact components size, simple cycle configuration, and compatibility with various heat sources. The Supercritical CO{sub 2} Brayton Cycle Integral Experiment Loop (SCIEL) has been installed in Korea Atomic Energy Research Institute (KAERI) to develop the base 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.

Noise analysis of fluid-valve system in a linear compressor using CAE

International Nuclear Information System (INIS)

Lee, Jun Ho; Jeong, Weui Bong; Kim, Dang Ju

2009-01-01

A linear compressor in a refrigerator uses piston motion to transfer refrigerant so its efficiency is higher than a previous reciprocal compressor. Because of interaction between refrigerant and valves system in the linear compressor, however, noise has been a main issue. In spite of doing many experimental researches, there is no way to rightly predict the noise. In order to solve this limitation, the CAE analysis is applied. For giving credit to these computational data, all of the data are experimentally validated.

Frequency regulated compact screw compressors. The new solution; Drehzahlgeregelte Kompakt-Schraubenverdichter. Die neue Loesung

Energy Technology Data Exchange (ETDEWEB)

Juergensen, Heinz [BITZER Kuehlmaschinenbau GmbH, Sindelfingen (Germany)

2012-07-01

Compact screw compressors have been used for many years in liquid chilling packages for comfort air conditioners, process cooling or heat pumps with mechanical power control. Standard frequency inverters offer the possibility to adjust the performance of a conventional screw compressor, piston compressor or scroll compressor in a small range of frequency. Furthermore, frequency inverters contain a number of additional functions. This combination of existing frequency inverters and compressors - as actually offered in many cases - allows only a limited improvement of the part-load performance in the system. Due to the high cost for the frequency inverters, this combination becomes economically questionable. An integrated package of newly developed compact screw compressors and a specially developed liquid-cooled frequency inverter is required in order to come to a new level of system efficiency at part load. In addition to the increased control range of the compressor, new possibilities can be opened up in terms of application and communication. The monitoring of various values such as the compliance with the application limits for pressure and temperature and especially the early warning against exceedance facilitates a more simply implementation of a secure machine because the setting of the relevant protection functions of the integrated type-specific components already is made in the factory.

Development of a High Efficiency Compressor/Expander for an Air Cycle Air Conditioning System.

Science.gov (United States)

1982-11-15

bearing, lb PHUB - Hub pressure (initial guess), psia RLG - Rotor length 1 ’B-2 RPM - Rotational speed, RPM R - Gas constant, lb -ft/lb - R CP - Specific...Compressor discharge port pressure ratio (PCD/PC2).:- CDP - Compressor pressure change, PCD-PCl PHUB - Pressure in compressor hub (acting on base of vanes

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

International Nuclear Information System (INIS)

Hiratsuka, Y

2015-01-01

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

40 CFR 264.1053 - Standards: Compressors.

Science.gov (United States)

2010-07-01

... with the barrier fluid at a pressure that is at all times greater than the compressor stuffing box... purges the barrier fluid into a hazardous waste stream with no detectable emissions to atmosphere. (c...

Magnetic power piston fluid compressor

Science.gov (United States)

Gasser, Max G. (Inventor)

1994-01-01

A compressor with no moving parts in the traditional sense having a housing having an inlet end allowing a low pressure fluid to enter and an outlet end allowing a high pressure fluid to exit is described. Within the compressor housing is at least one compression stage to increase the pressure of the fluid within the housing. The compression stage has a quantity of magnetic powder within the housing, is supported by a screen that allows passage of the fluid, and a coil for selectively providing a magnetic field across the magnetic powder such that when the magnetic field is not present the individual particles of the powder are separated allowing the fluid to flow through the powder and when the magnetic field is present the individual particles of the powder pack together causing the powder mass to expand preventing the fluid from flowing through the powder and causing a pressure pulse to compress the fluid.

Preliminary Design and Investigation of Integrated Compressor with Composite Material Wheel

Science.gov (United States)

Wang, Jifeng; Müller, Norbert

2012-06-01

An integrated water vapor compressor with composite material wheel is developed and strength analysis using FEM is presented. The design of wound composite material allows for integrating all rotating parts of the drive that may simply reduce to only the rotor of the electrical motor, since no drive shaft is required anymore. This design can reduce the number of parts and mass, which is convenient for engineers to maintain the compressor. The electrical motors are brushless DC motors operating through a frequency drive and apply a torque on the wheels through the materials bonded in the wheel shrouds. This system allows a large amount of compression to be produced in a multi-stage compression setup. To determine the stress and vibration characteristics of this integrated compressor, numerical analysis is carried out using FEM. The simulation result shows that the integrated compressor with composite material wheel can be used in a chiller system where water as a refrigerant.

Centrifugal compressor fault diagnosis based on qualitative simulation and thermal parameters

Science.gov (United States)

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

2016-12-01

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.

Evaluation and analysis on the coupling performance of a high-speed turboexpander compressor

Science.gov (United States)

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

2017-12-01

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.

Flow Characterization and Dynamic Analysis of a Radial Compressor with Passive Method of Surge Control

Science.gov (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

Predicting off-design range and performance of refrigeration cycle with two-stage centrifugal compressor and flash intercooler

Energy Technology Data Exchange (ETDEWEB)

Turunen-Saaresti, Teemu; Roeyttae, Pekka; Honkatukia, Juha; Backman, Jari [Lappeenranta University of Technology, Institute of Energy Technology, Laboratory of Fluid Dynamics, P.O. Box 20, 53851 Lappeenranta (Finland)

2010-09-15

A modern refrigeration process requires constant control to provide required cooling for the user. To properly and economically accommodate this need, a wide operation range of the compressor is necessary. Therefore, it is of interest to investigate the off-design operation of a cooling cycle and compressor. The refrigeration cycle equipped with a two-stage centrifugal compressor and a flash intercooler is studied. The compressor operation maps are generated with two different design codes and the operation values of the compressors are interpolated from the compressor maps in the simulation of the entire cooling cycle. Based on the previous studies of the utilised refrigeration cycle, R245fa is selected as coolant. The aim of this study is to demonstrate the control capacity of the centrifugal compressor and the performance of the cooling loop in off-design conditions. This configuration provides better and wider control over the cooling range than the traditional on-off control of displacement compressors. (author)

Refrigeration system with a compressor-pump unit and a liquid-injection desuperheating line

Science.gov (United States)

Gaul, Christopher J.

2001-01-01

The refrigeration system includes a compressor-pump unit and/or a liquid-injection assembly. The refrigeration system is a vapor-compression refrigeration system that includes an expansion device, an evaporator, a compressor, a condenser, and a liquid pump between the condenser and the expansion device. The liquid pump improves efficiency of the refrigeration system by increasing the pressure of, thus subcooling, the liquid refrigerant delivered from the condenser to the expansion device. The liquid pump and the compressor are driven by a single driving device and, in this regard, are coupled to a single shaft of a driving device, such as a belt-drive, an engine, or an electric motor. While the driving device may be separately contained, in a preferred embodiment, the liquid pump, the compressor, and the driving device (i.e., an electric motor) are contained within a single sealable housing having pump and driving device cooling paths to subcool liquid refrigerant discharged from the liquid pump and to control the operating temperature of the driving device. In another aspect of the present invention, a liquid injection assembly is included in a refrigeration system to divert liquid refrigerant from the discharge of a liquid pressure amplification pump to a compressor discharge pathway within a compressor housing to desuperheat refrigerant vapor to the saturation point within the compressor housing. The liquid injection assembly includes a liquid injection pipe with a control valve to meter the volume of diverted liquid refrigerant. The liquid injection assembly may also include a feedback controller with a microprocessor responsive to a pressure sensor and a temperature sensor both positioned between the compressor to operate the control valve to maintain the refrigerant at or near saturation.

40 CFR 265.1053 - Standards: Compressors.

Science.gov (United States)

2010-07-01

...) Operated with the barrier fluid at a pressure that is at all times greater than the compressor stuffing box... purges the barrier fluid into a hazardous waste stream with no detectable emissions to atmosphere. (c...

High Efficiency Pneumatic Systems Compressors Hydrodynamics and Termodynamics Process Research

Directory of Open Access Journals (Sweden)

Paulius Bogdevičius

2016-12-01

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.

Proposal to neutralize acid fluids from wells in the Los Humeros, Pue., geothermal field; Propuesta para la neutralizacion de fluidos acidos provenientes de pozos del campo geotermico de Los Humeros, Pue.

Energy Technology Data Exchange (ETDEWEB)

Flores Armenta, Magaly del Carmen; Ramirez Montes, Miguel; Garcia Cuevas, Juan Manuel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx

2009-07-15

Neutralizing an acidic fluid consists of adding a sodium hydroxide solution to neutralize the H group of acids, therefore increasing the pH. The injection of sodium hydroxide has to be continuous and at a proper depth inside the well to protect against the corrosion of casing and surface equipment. Neutralization is a common practice used in geothermal fields, such as at The Geysers in the US and Miravalles in Costa Rica-places where aggressive fluids cause problems for extracting and using geothermal fluids commercially. A zone surrounding wells H-4, H-16 and H-29 in the northern section of the Los Humeros, Pue., geothermal field, known as the Colapso Central, has shown evidence of aggressively acidic fluids. Several wells drilled in the area had to be repaired, thus plugging and isolating the deepest production zones. Well H-43 was drilled two years ago in the northern zone of the field, and even though it is not located in the aggressive-fluid zone, the well presents mineralogical features possibly indicating the presence of acidic fluids. Therefore, before producing this well it has been proposed we install a neutralization system with general characteristics presented in this paper. The system will prevent corrosion that up to now has prevented exploitation of the deep portion of Colapso Central, helping to develop the field in a more profitable way. [Spanish] Neutralizar un fluido acido consiste en agregarle una solucion de hidroxido de sodio. Esto neutraliza el grupo de acidos H y en consecuencia aumenta el pH. La inyeccion de hidroxido de sodio se realiza de manera continua y a una profundidad adecuada dentro del pozo para proteger a la tuberia y a todo el equipo superficial contra la corrosion. La neutralizacion es una practica comun que se viene realizando en campos como Los Geysers en Estados Unidos y en Miravalles, Costa Rica, donde la presencia de fluidos agresivos causa problemas en la extraccion y aprovechamiento del fluido geotermico con fines

Screw compressor system for industrial-scale helium refrigerators or industrial ammonia screw compressors for helium refrigeration systems; Schraubenkompressor-System fuer Helium-Grosskaelteanlage oder Ammoniak-Schraubenverdichter aus Industrieanwendungen fuer Helium-Kaelteanlagen

Energy Technology Data Exchange (ETDEWEB)

Fredrich, O.; Mosemann, D.; Zaytsev, D. [GEA Grasso GmbH Refrigeration Technology, Berlin (Germany)

2007-07-01

Material characteristics, requirements and measured data of ammonia and helium compression are compared. The compressor lines for industrial ammonia and helium refrigerators are presented, and important characteristics of the compressors are explained. The test stand for performance measurements with helium and ammonia is described, and results are presented. In spite of the different characteristics of the fluids, the compressor-specific efficiencies (supply characteristic, quality characteristic) were found to be largely identical. The values calculated for helium on the basis of NH3 test runs were found to be realistic, which means that the decades of experience with ammonia in industrial applications can be applied to helium compression as well. The design of screw compressor aggregates (skids) in industrial refrigeration is discussed and illustrated by examples. (orig.)

Transient modeling of an air conditioner with a rapid cycling compressor and multi-indoor units

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wei-Jiang [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang, Chun-Lu [College of Mechanical Engineering, Tongji University, 4800 Cao An Highway, Shanghai 201804 (China)

2011-01-15

Rapid cycling the compressor is an alternative of the variable speed compressor to modulate the capacity of refrigeration systems for the purpose of energy saving at part-load conditions. The multi-evaporator air conditioner combined with the rapid cycling compressor brings difficulties in control design because of the sophisticated system physics and dynamics. In this paper the transient model of a multi-split air conditioner with a digital scroll compressor is developed for predicting the system transients under performance modulations. The predicted cycling dynamics are in good agreement with the experimental data. Based on the validated model, the impact of compressor idle power and cycle period to the part load performance is discussed. (author)

Transient modeling of an air conditioner with a rapid cycling compressor and multi-indoor units

Energy Technology Data Exchange (ETDEWEB)

Zhang Weijiang [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang Chunlu, E-mail: chunlu.zhang@carrier.utc.co [College of Mechanical Engineering, Tongji University, 4800 Cao An Highway, Shanghai 201804 (China)

2011-01-15

Rapid cycling the compressor is an alternative of the variable speed compressor to modulate the capacity of refrigeration systems for the purpose of energy saving at part-load conditions. The multi-evaporator air conditioner combined with the rapid cycling compressor brings difficulties in control design because of the sophisticated system physics and dynamics. In this paper the transient model of a multi-split air conditioner with a digital scroll compressor is developed for predicting the system transients under performance modulations. The predicted cycling dynamics are in good agreement with the experimental data. Based on the validated model, the impact of compressor idle power and cycle period to the part load performance is discussed.

Transient modeling of an air conditioner with a rapid cycling compressor and multi-indoor units

International Nuclear Information System (INIS)

Zhang Weijiang; Zhang Chunlu

2011-01-01

Rapid cycling the compressor is an alternative of the variable speed compressor to modulate the capacity of refrigeration systems for the purpose of energy saving at part-load conditions. The multi-evaporator air conditioner combined with the rapid cycling compressor brings difficulties in control design because of the sophisticated system physics and dynamics. In this paper the transient model of a multi-split air conditioner with a digital scroll compressor is developed for predicting the system transients under performance modulations. The predicted cycling dynamics are in good agreement with the experimental data. Based on the validated model, the impact of compressor idle power and cycle period to the part load performance is discussed.

An Investigation of Surge in a High-Speed Centrifugal Compressor Using Digital PIV

Science.gov (United States)

Wernet, Mark P.; Bright, Michelle M.; Skoch, Gary J.

2002-01-01

Compressor stall is a catastrophic breakdown of the flow in a compressor, which can lead to a loss of engine power, large pressure transients in the inlet/nacelle and engine flameout. The implementation of active or passive strategies for controlling rotating stall and surge can significantly extend the stable operating range of a compressor without substantially sacrificing performance. It is crucial to identify the dynamic changes occurring in the flow field prior to rotating stall and surge in order to successfully control these events. Generally, pressure transducer measurements are made to capture the transient response of a compressor prior to rotating stall. In this investigation, Digital Particle Imaging Velocimetry (DPIV) is used in conjunction with dynamic pressure transducers to simultaneously capture transient velocity and pressure measurements in the non-stationary flow field during compressor surge. DPIV is an instantaneous, planar measurement technique which is ideally suited for studying transient flow phenomena in high speed turbomachinery and has been used previously to successfully map the stable operating point flow field in the diffuser of a high speed centrifugal compressor. Through the acquisition of both DPIV images and transient pressure data, the time evolution of the unsteady flow during surge is revealed.

Experimental study of a thermochemical compressor for an absorption/compression hybrid cycle

International Nuclear Information System (INIS)

Ventas, R.; Vereda, C.; Lecuona, A.; Venegas, M.

2012-01-01

Highlights: ► Experimental study of a thermochemical compressor for absorption/compression cycle. ► Spray adiabatic absorber using NH 3 –LiNO 3 solution working fluid. ► It is able to operate between 57 and 110 °C varying concentration between 0.46 and 0.59. ► The increase of absorber pressure decreases the circulation ratio. ► The numerical model performed agrees with the experimental results. -- Abstract: An experimental study of a thermochemical compressor with ammonia–lithium nitrate solution as working fluid has been carried out. This compressor incorporates a single-pass adiabatic absorber and all the heat exchangers are of the plate type: absorber subcooler, generator and solution heat exchanger. The thermochemical compressor has been studied as part of a single-effect absorption chiller hybridized with an in-series low-pressure compression booster. The adiabatic absorber uses fog jet injectors. The generator hot water temperatures for the external driving flow are in the range of 57–110 °C and the absorber pressures range between 429 and 945 kPa. Experimental results are compared with a numerical model showing a high agreement. The performance of the thermochemical compressor, evaluated through the circulation ratio, improves for higher absorber pressures, indicating the potential of pressure boosting. For the same circulation ratio, the driving hot water inlet temperature decreases with the rise of the absorber pressure. The thermochemical compressor, based on an adiabatic absorber, can produce refrigerant with very low driving temperatures, between 57 and 70 °C, what is interesting for solar cooling applications and very low temperature residual heat recovery. Efficiencies and cooling power are offered when this hybrid thermochemical compressor is implemented in a chiller, showing the effect of different operating parameters.

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

Directory of Open Access Journals (Sweden)

Chehhat A.

2016-12-01

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.

Optimization Design of IGV Profile in Centrifugal Compressor

Directory of Open Access Journals (Sweden)

Qi Sun

2017-01-01

Full Text Available Variable inlet guide vane (IGV is used to control the mass flow and generate prewhirl in centrifugal compressors. The efficient operation of IGV is limited to the range of aerodynamic characteristics of their vane profiles. In order to find out the best vane profile for IGV regulation, the modern optimization method was adopted to optimize the inlet guide vane profile. The main methodology idea was to use artificial neural network for continuous fitness evaluation and use genetic algorithm for global optimization. After optimization, the regulating performance of IGV has improved significantly, the prewhirl ability has been enhanced greatly, and the pressure loss has been reduced. The mass flow and power of compressor reduced by using the optimized guide vane at large setting angles, and the efficiency increased significantly; the flow field distribution has been improved obviously, since the nonuniform distribution of flow and flow separation phenomenon greatly weakened or even completely disappeared. The achievement of this research can effectively improve the regulation ability of IGV and the performance of compressor.

Helium compressor aerodynamic design considerations for MHTGR circulators

International Nuclear Information System (INIS)

McDonald, C.F.

1988-01-01

Compressor aerodynamic design considerations for both the main and shutdown cooling circulators in the Modular High-Temperature Gas-Cooled Reactor (MHTGR) plant are addressed in this paper. A major selection topic relates to the impeller type (i.e., axial or radial flow), and the aerothermal studies leading to the selection of optimum parameters are discussed. For the conceptual designs of the main and shutdown cooling circulators, compressor blading geometries were established and helium gas flow paths defined. Both circulators are conservative by industrial standards in terms of aerodynamic and structural loading, and the blade tip speeds are particularly modest. Performance characteristics are presented, and the designs embody margin to ensure that pressure-rise growth potential can be accomodated should the circuit resistance possibly increase as the plant design advances. The axial flow impeller for the main circulator is very similar to the Fort St. Vrain (FSV) helium compressor which performs well. A significant technology base exists for the MHTGR plant circulators, and this is highlighted in the paper. (author). 15 refs, 16 figs, 12 tabs

Stepless control system for reciprocating compressors: energy savings + process control improvement

Energy Technology Data Exchange (ETDEWEB)

Grande, Alvaro; Wenisch, Markus [Hoerbiger Ventilwerke GmbH and Co KG, Wien (Austria); Jacobs, Denis [HOERBIGER do Brasil Industria de Equipamentos, Cajamar, SP (Brazil)

2012-07-01

In the past, the capacity of reciprocating compressors was typically controlled by on/off unloaders (step-control) and recycle valves. But due to the fact that the power ratings of new reciprocating compressors for the oil and gas industry increase significantly, advanced control systems are required to reduce power costs and save energy. On top of that, multi-stage compressors are frequently integrated into complex process plants that demand precise control and operational flexibility. There are several solutions for this equation, but maybe the most successful is the use of the reverse flow principle applied to an electronically controlled and hydraulically actuated suction valve unloaders system. (author)

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)

1997-11-01

(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)

Compressor with pump recycling for isotopic separation through gaseous scattering

International Nuclear Information System (INIS)

Plotkowiak, J.; Quillevere, H.A.

1984-01-01

A compressor which compresses a principal flow at low pressure and recompresses a secondary flow at medium pressure to deliver a common flow at high pressure is disclosed. The compressor includes, in addition to compression devices for the principal flow, static devices forming an induction nozzle housed in the scatterer and devices to introduce therein the secondary flow, the principal flow constituting the drive flow

Determination of Pressure Fluctuations in Rotor Bundle of Centrifugal Compressor at Critical Conditions of Operation

Science.gov (United States)

Levashov, V. A.; Lyubchenko, K. Yu

2017-08-01

This article describes the physical processes that occur in the stage flow part of the compressor while it is operating and can create conditions for the occurrence of forced vibrations, which in turn can lead to the destruction of the impellers. Critical conditions of compressor operation are determined. To understand that critical condition of operation is cause of the destruction of the impellers, transient CFD analysis was carried for test stage of compressor. The obtained pressure fluctuation amplitudes allow to evaluate the critical conditions of compressor operation.

Modelamiento de Fluidos Magnetoreológicos (FMR Producidos con Magnetita Mineral

Directory of Open Access Journals (Sweden)

Claudia Molina

2015-07-01

Full Text Available Esta investigación establece la correlación entre los resultados del cambio de densidad de un FMR, expuesto a un campo magnético de intensidad variable, con los resultados de la simulación del sistema por elementos finitos, en ANSYS. A nivel de laboratorio se prepararon doce muestras de FMR, con: magnetita mineral como material magnético molida a 325, 400 y 500 mallas; aceites 20W30 y 20W50 como fluidos de transporte y, aditivos antigravitacionales y antiaglomerantes. Con el FMR de mayor estabilidad fisicoquímica (baja reactividad y sedimentación, se realizaron pruebas de variación de la densidad, en función de la intensidad de un campo magnético. La correlación de los resultados de las pruebas de laboratorio con los resultados de la simulación, fue de 0.92, lo cual indica que la predicción del comportamiento de la densidad del FMR, en presencia de un campo magnético de intensidad variable, es un procedimiento confiable.

Acoustical contribution calculation and analysis of compressor shell based on acoustic transfer vector method

Science.gov (United States)

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

2017-08-01

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.

Determination of the Optimal Operating Parameters for the Jefferson Lab's Cryogenic Cold Compressor System

International Nuclear Information System (INIS)

Joe Wilson; Venkatarao Ganni; Dana Arenius; Jonathan Creel

2004-01-01

Jefferson Lab's (JLab) Continuous Electron Beam Accelerator Facility (CEBAF) and Free Electron Laser (FEL) are supported by 2 K helium refrigerator known as the Central Helium Liquefier (CHL), which maintains a constant low vapor pressure over the accelerators' large liquid helium inventory with a five-stage centrifugal compressor train. The cold compressor train operates with constrained discharge pressure and can be varied over a range of suction pressures and mass flows to meet the operational requirements of the two accelerators. Using data from commissioning and routine operations of the cold compressor system, the presented procedure predicts an operating point for each cold compressor such that maximum efficiency is attained for the overall cold compressor system for a given combination of mass flow and vapor pressure. The procedure predicts expected efficiency of the system and relative compressors speeds for operating vapor pressures from 4 to 2.5 kPa (corresponds to overall pressure ratios of 29 to 56) and flow rates of 135 g/s to 250 g/s. The results of the predictions are verified by test for a few operating conditions of mass flows and vapor pressures

Study on the CO2 electric driven fixed swash plate type compressor for eco-friendly vehicles

Science.gov (United States)

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

2017-08-01

The purpose of this study is to experiment and to performance analysis about the electric-driven fixed swash plate compressor using alternate refrigerant(R744). Comprehensive simulation model for an electric driven compressor using CO2 for eco-friendly vehicle is presented. This model consists of compression model and dynamic model. The compression model included valve dynamics, leakage, and heat transfer models. And the dynamic model included frictional loss between piston ring and cylinder wall, frictional loss between shoe and swash plate, frictional loss of bearings, and electric efficiency. Especially, because the efficiency of an electric parts(motor and inverter) in the compressor affects the loss of the compressor, the dynamo test was performed. We made the designed compressor, and tested the performance of the compressor about the variety pressure conditions. Also we compared the performance analysis result and performance test result.

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

Science.gov (United States)

Marsh, Jan H.; Marra, John J.

2017-11-21

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.

Internal flow measurement in transonic compressor by PIV technique

Science.gov (United States)

Wang, Tongqing; Wu, Huaiyu; Liu, Yin

2001-11-01

The paper presents some research works conducted in National Key Laboratory of Aircraft Engine of China on the shock containing supersonic flow measurement as well as the internal flow measurement of transoijc compressor by PIC technique. A kind of oil particles in diameter about 0.3 micrometers containing in the flow was discovered to be a very good seed for the PIV measurement of supersonic jet flow. The PIV measurement in over-expanded supersonic free jet and in the flow over wages show a very clear shock wave structure. In the PIV internal flow measurement of transonic compressor a kind of liquid particle of glycol was successful to be used as the seed. An illumination periscope with sheet forming optics was designed and manufactured, it leaded the laser shot generated from an integrate dual- cavity Nd:YAG laser of TSI PIV results of internal flow of an advanced low aspect ratio transonic compressor were shown and discussed briefly.

Effect of piping systems on surge in centrifugal compressors

International Nuclear Information System (INIS)

Tamaki, Hideaki

2008-01-01

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

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

Science.gov (United States)

Owen, A. K.

1994-01-01

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

ADVANCED COMPRESSOR ENGINE CONTROLS TO ENHANCE OPERATION, RELIABILITY AND INTEGRITY

Energy Technology Data Exchange (ETDEWEB)

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

2004-03-01

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.

Experimental study on p-V indicator diagrams of twin-screw refrigeration compressor with economizer

International Nuclear Information System (INIS)

Wu Huagen; Peng Xueyuan; Xing Ziwen; Shu Pengcheng

2004-01-01

This paper presents the experimental investigation on the effects of the superfeed pressure together with economizer type on the performance of the twin-screw refrigeration compressor by means of the indicator diagram. With a pressure sensor embedded into the groove at the root of the female rotor on the discharge side, the pressure within the working chamber of a semi-hermetic twin-screw compressor with an economizer is recorded and then transformed into the indicator diagram. The results thus obtained are utilized to investigate the thermodynamic process of the compressor. It is shown that the compressor with an economizer has higher pressure during almost the whole compression process than without an economizer, resulting in the increase in the indicated power. Under different superfeed pressures, the pressure within the compression experiences different changes. This results in an optimal superfeed pressure for maximized compressor efficiency, which can be identified from the calculated compressor efficiency based on the indicator diagrams. It is also found that the pressure has a rapid increase at the beginning of superfeed process, and then a slow rise even a slight drop at the end of superfeed process, which is caused by the dynamic effect during superfeed process. Furthermore, if the superfeed pressure keeps the same, the pressure during compression in the compressor with the heat exchanger economizer is slightly higher than with the flash tank economizer, due to the higher temperature of superfeed refrigerant gas in the former case

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

Science.gov (United States)

McKain, Ted F.; Holbrook, Greg J.

1997-01-01

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

Performance estimates for the Space Station power system Brayton Cycle compressor and turbine

Science.gov (United States)

Cummings, Robert L.

1989-01-01

The methods which have been used by the NASA Lewis Research Center for predicting Brayton Cycle compressor and turbine performance for different gases and flow rates are described. These methods were developed by NASA Lewis during the early days of Brayton cycle component development and they can now be applied to the task of predicting the performance of the Closed Brayton Cycle (CBC) Space Station Freedom power system. Computer programs are given for performing these calculations and data from previous NASA Lewis Brayton Compressor and Turbine tests is used to make accurate estimates of the compressor and turbine performance for the CBC power system. Results of these calculations are also given. In general, calculations confirm that the CBC Brayton Cycle contractor has made realistic compressor and turbine performance estimates.

High stability design for new centrifugal compressor

Science.gov (United States)

Kanki, H.; Katayama, K.; Morii, S.; Mouri, Y.; Umemura, S.; Ozawa, U.; Oda, T.

1989-01-01

It is essential that high-performance centrifugal compressors be free of subsynchronous vibrations. A new high-performance centrifugal compressor has been developed by applying the latest rotordynamics knowledge and design techniques: (1) To improve the system damping, a specially designed oil film seal was developed. This seal attained a damping ratio three times that of the conventional design. The oil film seal contains a special damper ring in the seal cartridge. (2) To reduce the destabilizing effect of the labyrinth seal, a special swirl canceler (anti-swirl nozzle) was applied to the balance piston seal. (3) To confirm the system damping margin, the dynamic simulation rotor model test and the full load test applied the vibration exciting test in actual load conditions.

Effect on Vehicle Turbocharger Exhaust Gas Energy Utilization for the Performance of Centrifugal Compressors under Plateau Conditions

Directory of Open Access Journals (Sweden)

Hong Zhang

2017-12-01

Full Text Available This paper is focused on the performance of centrifugal compressors for vehicle turbochargers operating at high altitude. The reasons for turbocharged diesel engine power loss increases and bad economy performance caused by exhaust gas energy utilization are investigated. The atmosphere’s impact on the turbocharger centrifugal compressor’s energy distribution characteristics under the plateau is discussed. The key parameters that affect compressor characteristics are concluded in a theoretical method. A simulation calculation model is established to accurately predict compressor performance at high altitude. By comparing the experimental results, the calculation results are validated. The details of the internal flow fields analysis, including critical parameters of a compressor operating at high altitude, are analyzed. The results show that with the increase of altitude from 0 m to 4500 m, the peak efficiency of the compressor is reduced by 2.4%, while the peak pressure ratio is increased by 7%. The main influence characters of the plateau environment on the turbocharger centrifugal compressor performance, such as blade loads, exergy utilization and entropy distribution are concluded. The key factors for compressor performance and compressor energy flow control design method operated at high altitude are obtained.

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

International Nuclear Information System (INIS)

Han, Feng Hui; Mao, Yi Jun; Tan, Ji Jian

2016-01-01

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

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)

2016-11-15

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.

Investigation of turbocharger compressor surge inception by means of an acoustic two-port model

Science.gov (United States)

Kabral, R.; Åbom, M.

2018-01-01

The use of centrifugal compressors have increased tremendously in the last decade being implemented in the modern IC engine design as a key component. However, an efficient implementation is restricted by the compression system surge phenomenon. The focus in the investigation of surge inception have mainly been on the aerodynamic field while neglecting the acoustic field. In the present work a new method based on the full acoustic 2-port model is proposed for investigation of centrifugal compressor stall and surge inception. Essentially, the compressor is acoustically decoupled from the compression system, hence enabling the determination of sound generation and the quantification of internal aero-acoustic coupling effects, both independently of the connected pipe system. These frequency dependent quantities are indicating if the compressor is prone to self-sustained oscillations in case of positive feedback when installed in a system. The method is demonstrated on experimentally determined 2-port data of an automotive turbocharger centrifugal compressor under a variety of realistic operating conditions.

Centrifugal-reciprocating compressor

Science.gov (United States)

Higa, W. H. (Inventor)

1984-01-01

A centrifugal compressor is described which includes at least one pair of cylinders arranged in coaxial alignment and supported for angular displacement about a common axis of rotation normally disecting a common longitudinal axis of symmetry for the cylinders. The cylinders are characterized by ported closures located at the mutually remote ends thereof through which the cylinders are charged and discharged, and a pair of piston heads seated within the cylinders and supported for floating displacement in compressive strokes in response to unidirectional angular displacement imparted to the cylinders.

Flow and pressure characteristics within a screw compressor

Science.gov (United States)

Guerrato, D.; Nouri, J. M.; Stosic, N.; Arcoumanis, C.

2007-10-01

The angle-resolved mean and turbulence characteristics of the axial air flow inside a screw compressor with both male and female rotors have been measured, using a laser Doppler velocimeter (LDV) with high spatial and temporal resolution at different radial and axial locations for speeds of 800-1600 rpm, discharge pressures of 1-1.6 bar and discharge temperatures of 33-90°C. The velocity measurements were performed through a special transparent window fixed near the discharge port. The results confirmed the ability of the LDV technique to characterise the flow inside the compressor working chamber; an angular resolution of 1.5° was able to fully describe the velocity field within the machine. The flow variation between the different working chambers was established as well as the spatial variation of the axial mean velocity and turbulence velocity fluctuation within the working chamber. The effect of discharge port opening on the axial mean and RMS velocities was found to be significant near the leading edge of the rotors causing an increase in the mean and RMS velocities of the order of 4.2Vp in mean (where Vp is the axial pitched velocity) for male rotor and 5.4Vp for, female rotor and this effect is less pronounced on the flow near the root of the rotor. Moreover, to obtain a better understanding of the flow motion, a high sampling rate pressure transducer was used to provide the internal angular static pressure variation. These measurements are used to validate the in-house CFD model of the fluid flow within twin screw compressors which, in turn, allows reliable optimisation of various compressor designs.

Flow and pressure characteristics within a screw compressor

International Nuclear Information System (INIS)

Guerrato, D; Nouri, J M; Stosic, N; Arcoumanis, C

2007-01-01

The angle-resolved mean and turbulence characteristics of the axial air flow inside a screw compressor with both male and female rotors have been measured, using a laser Doppler velocimeter (LDV) with high spatial and temporal resolution at different radial and axial locations for speeds of 800-1600 rpm, discharge pressures of 1-1.6 bar and discharge temperatures of 33-90 0 C. The velocity measurements were performed through a special transparent window fixed near the discharge port. The results confirmed the ability of the LDV technique to characterise the flow inside the compressor working chamber; an angular resolution of 1.5 0 was able to fully describe the velocity field within the machine. The flow variation between the different working chambers was established as well as the spatial variation of the axial mean velocity and turbulence velocity fluctuation within the working chamber. The effect of discharge port opening on the axial mean and RMS velocities was found to be significant near the leading edge of the rotors causing an increase in the mean and RMS velocities of the order of 4.2V p in mean (where V p is the axial pitched velocity) for male rotor and 5.4V p for, female rotor and this effect is less pronounced on the flow near the root of the rotor. Moreover, to obtain a better understanding of the flow motion, a high sampling rate pressure transducer was used to provide the internal angular static pressure variation. These measurements are used to validate the in-house CFD model of the fluid flow within twin screw compressors which, in turn, allows reliable optimisation of various compressor designs

Rotating flux compressor for energy conversion

International Nuclear Information System (INIS)

Chowdhuri, P.; Linton, T.W.; Phillips, J.A.

1983-01-01

The rotating flux compressor (RFC) converts rotational kinetic energy into an electrical output pulse which would have higher energy than the electrical energy initially stored in the compressor. An RFC has been designed in which wedge-shaped rotor blades pass through the air gaps between successive turns of a solenoid, the stator. Magnetic flux is generated by pulsing the stator solenoids when the inductance is a maximum, i.e., when the flux fills the stator-solenoid volume. Connecting the solenoid across a load conserves the flux which is compressed within the small volume surrounding the stator periphery when the rotor blades cut into the free space between the stator plates, creating a minimum-inductance condition. The unique features of this design are: (1) no electrical connections (brushes) to the rotor; (2) no conventional windings; and (3) no maintenance. The device has been tested up to 5000 rpm of rotor speed

Data compressor designed to improve recognition of magnetic phases

Science.gov (United States)

Vogel, E. E.; Saravia, G.; Cortez, L. V.

2012-02-01

Data compressors available in the web have been used to determine magnetic phases for two-dimensional (2D) systems [E. Vogel, G. Saravia, F. Bachmann, B. Fierro, J. Fischer, Phase transitions in Edwards-Anderson model by means of information theory, Physica A 388 2009 4075-4082]. In the present work, we push this line forward along four different directions. First, the compressor itself: we design a new data compressor, named wlzip, optimized for the recognition of information having physical (or scientific) information instead of the random digital information usually compressed. Second, for the first time we extend the data compression analysis to the 3D Ising ferromagnetic model using wlzip. Third, we discuss the tuning possibilities of wlzip in terms of the number of digits considered in the compression to yield maximum definition; in this way, the transition temperature of both 2D and 3D Ising ferromagnets can be reported with very good resolution. Fourth, the extension of the time window through which the data file is actually compressed is also considered to get optimum accuracy. The paper is focused on the new compressor, its algorithm in general and the way to apply it. Advantages and disadvantages of wlzip are discussed. Toward the end, we mention other possible applications of this technique to recognize stable and unstable regimes in the evolution of variables in meteorology (such as pollution content or atmospheric pressure), biology (blood pressure) and econophysics (prices of the stock market).

Numerical simulation and experimental investigation on suction heating of a BOG compressor

International Nuclear Information System (INIS)

Jia, Xiaohan; Zhao, Bin; Feng, Jianmei; Zheng, Sulu; Peng, Xueyuan

2016-01-01

Highlights: • An investigation focusing on suction heating of a BOG compressor is carried out. • There is frost on the cylinder cover as the compressor at lower suction temperature. • The suction and discharge flow rate decrease with rising suction temperature. • The volumetric efficiency has a maximum value with increasing suction temperature. • The temperature coefficient increased with suction temperature or rotational speed. - Abstract: One of the key components of a liquefied natural gas (LNG) receiving terminal is the boil-off gas (BOG) compressor, which is used to pump out the BOG from the LNG storage tank to ensure safety in the transportation and receiving systems. Owing to the ultra-low suction temperature, the heat exchange between the intake gas and the cylinder, piston, and cylinder cover cannot be ignored as in normal conditions. This paper presents an investigation focusing on suction heating of the BOG compressor. A finite element model with dynamic mesh was established to simulate the suction process. At the same time, a performance test rig was built to study the characteristics of the BOG compressor under low suction temperature conditions and verify the numerical model. Consequently, the results of the simulation were in good agreement with experimental results. Both results implied that the temperature of cylinder surface increased starting from the cylinder cover to the crankcase. In addition, at lower suction temperature, the temperature difference between various points on the cylinder surface and cylinder cover was much larger than that at higher suction temperature. With increasing suction temperature, the temperature coefficient increased markedly, and the difference between gas temperatures at the beginning and end of the suction process, as well as the compressor flow rate, decreased significantly; however, the volumetric efficiency increased first and then decreased. Furthermore, the temperature coefficient clearly increased

Numerical analysis of gas leakage in the piston-cylinder clearance of reciprocating compressors considering compressibility effects

Science.gov (United States)

Braga, V. M.; Deschamps, C. J.

2017-08-01

Leakage is a major source of inefficiency in low-capacity reciprocating compressors. Not only does it lower the mass flow rate provided by the compressor, reducing its volumetric efficiency, but also gives rise to outflux of energy that decreases the isentropic efficiency. Leakage in the piston-cylinder clearance of reciprocating compressors is driven by the piston motion and pressure difference between the compression chamber and the shell internal environment. In compressors adopted for domestic refrigeration, such a clearance is usually filled by a mixture of refrigerant and lubricating oil. Besides its lubricating function, the oil also acts as sealing element for the piston-cylinder clearance, and hence leakage is expected to be more detrimental to oil-free compressors. This paper presents a model based on the Reynolds equation for compressible fluid flow to predict leakage in oil-free reciprocating compressors. The model is solved throughout the compression cycle so as to assess the effect of the clearance geometry and piston velocity on leakage and compressor efficiency. The results show that compressible fluid flow formulation must be considered for predictions of gas leakage in the cylinder-piston clearance.

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

Science.gov (United States)

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

2017-08-01

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

Control optimization of the cryoplant warm compressor station for EAST

International Nuclear Information System (INIS)

Zhuang, M.; Hu, L. B.; Zhou, Z. W.; Xia, G. H.

2014-01-01

The cryogenic control system for EAST (Experimental Advanced Superconducting Tokamak) was designed based on DeltaV DCS of Emerson Corporation. The automatic control of the cryoplant warm compressors has been implemented. However, with ever-degrading performance of critical equipment, the cryoplant operation in the partial design conditions makes the control system fluctuate and unstable. In this paper, the warm compressor control system was optimized to eliminate the pressure oscillation based on the expert PID theory

Optimization analysis of the motor cooling method in semi-closed single screw refrigeration compressor

Science.gov (United States)

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

2017-08-01

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.

Fluidos iónicos en lubricación de contactos aluminio-acero : interacciones superficiales y triboquímicas

OpenAIRE

Jiménez Ballesta, Ana Eva

2009-01-01

Los líquidos iónicos (LI) son fluidos de altas prestaciones con un amplio rango de estabilidad térmica. Actualmente están siendo objeto de estudio en una gran variedad de contactos, siendo una de sus aplicaciones tribológicas más interesante la lubricación del contacto aluminio-acero. En este trabajo se estudia la influencia de la longitud de la cadena lateral del catión y de la naturaleza del anión sobre la capacidad lubricante de 6 LI derivados del catión imidazolio, un derivado de piridini...

Experimental Investigation of Inlet Distortion in a Multistage Axial Compressor

Science.gov (United States)

Rusu, Razvan

The primary objective of this research is to present results and methodologies used to study total pressure inlet distortion in a multi-stage axial compressor environment. The study was performed at the Purdue 3-Stage Axial Compressor Facility (P3S) which models the final three stages of a production turbofan engine's high-pressure compressor (HPC). The goal of this study was twofold; first, to design, implement, and validate a circumferentially traversable total pressure inlet distortion generation system, and second, to demonstrate data acquisition methods to characterize the inter-stage total pressure flow fields to study the propagation and attenuation of a one-per-rev total pressure distortion. The datasets acquired for this study are intended to support the development and validation of novel computational tools and flow physics models for turbomachinery flow analysis. Total pressure inlet distortion was generated using a series of low-porosity wire gauze screens placed upstream of the compressor in the inlet duct. The screens are mounted to a rotatable duct section that can be precisely controlled. The P3S compressor features fixed instrumentation stations located at the aerodynamic interface plane (AIP) and downstream and upstream of each vane row. Furthermore, the compressor features individually indexable stator vanes which can be traverse by up to two vane passages. Using a series of coordinated distortion and vane traverses, the total pressure flow field at the AIP and subsequent inter-stage stations was characterized with a high circumferential resolution. The uniformity of the honeycomb carrier was demonstrated by characterizing the flow field at the AIP while no distortion screens where installed. Next, the distortion screen used for this study was selected following three iterations of porosity reduction. The selected screen consisted of a series of layered screens with a 100% radial extent and a 120° circumferential extent. A detailed total

Elements for modeling and design of centrifugal compressor housings

International Nuclear Information System (INIS)

Magoia, J.E.; Calderon, T.

1990-01-01

Various aspects of the structural analysis of centrifugal compressor housings are studied. These are usually used in different kinds of nuclear sites. Multiple areas of the analysis are evaluated with elastic models based on finite elements: sensitivity to different variables, quality of models on facing theoretical solutions and performed measurements. The development of an excentric bar element improved for the rigidized plate model, is included. The definition of criteria for a more efficient structural analysis as well as recommendations for the design of centrifugal compressor housings concludes the work. (Author) [es

Effect of double air injection on performance characteristics of centrifugal compressor

Science.gov (United States)

Hirano, Toshiyuki; Ogawa, Tatsuya; Yasui, Ryutaro; Tsujita, Hoshio

2017-02-01

In the operation of a centrifugal compressor of turbocharger, instability phenomena such as rotating stall and surge are induced at a lower flow rate close to the maximum pressure ratio. In this study, the compressed air at the exit of centrifugal compressor was re-circulated and injected to the impeller inlet by using two injection nozzles in order to suppress the surge phenomenon. The most effective circumferential position was examined to reduce the flow rate at the surge inception. Moreover, the influences of the injection on the fluctuating property of the flow field before and after the surge inception were investigated by examining the frequency of static pressure fluctuation on the wall surface and visualizing the compressor wall surface by oil-film visualization technique.

CFD comparison with centrifugal compressor measurements on a wide operating range

Directory of Open Access Journals (Sweden)

Arnou D.

2013-04-01

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.

A study on the oil flow characteristics in the inverter rotary compressor

International Nuclear Information System (INIS)

Kim, H J; Kim, Y J

2013-01-01

In order to secure the reliability of the oil in the inverter rotary compressor used in the system multi-air conditioners in heating and cooling modes, it is necessary to study the oil flow characteristics which affect to the compressor efficiency. In this study, sight glasses were installed at the compressor and accumulator for oil flow measurements, and various experiments were performed to measure the amount of discharged oil for different refrigerant pipe lengths. On the basis of the experimental measurements, we compared the OCR (Oil Circulation Rate) results of the system multi-air conditioner for various operating conditions. The results are graphically depicted

Geometric Optimization of Turbocharger Compressor and Its Influence on Engine Performance

Directory of Open Access Journals (Sweden)

Zhang Fangming

2017-01-01

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.

A Numerical Simulation of Elastoplastic Contact Analysis of Compressor by Overspeeding

Directory of Open Access Journals (Sweden)

Aihua Liao

2014-04-01

Full Text Available This study analyzes the stress distribution of 3D elastoplastic contact problems by using the FE parametric quadratic programming (PQP method derived from a 3D FE model based on parametric variational principle (PVP. We numerically analyze a 24-blade compressor by combining centrifugal loading with interference-fit one. To accelerate computation, calculation is simplified by structural modeling via multisubstructuring, aiming to deal with FE-simulated computer aided design (CAD conveniently. We then analyze the relationships between the maximum residual stresses of the compressor posterior to prestressing and overspeed rpms, and we also study the distribution and magnitude of the contact stresses of the compressor in working conditions after overspeed prestressing. Moreover, we thoroughly discuss the distribution and magnitude of the contact stresses of shaft-shaft sleeve-impeller in working conditions. Relative displacement can be prevented and contact stress can be kept uniform due to the nonuniform initial amount of interference in overspeed prestressing. This paper summarizes the FEM simulation results and provides reference data for improving the design and processing of compressor impellers, indicating that overspeed is indispensable in manufacture.

Modernizing the 5G 100/8 piston compressor by means of directly streaming valves

Energy Technology Data Exchange (ETDEWEB)

Tsvetanov, Ts.; Stoyanov, I.

1988-02-01

Deals with 5G 100/8 air compressors which, despite long service and lack of spare parts, are still widely used in Bulgarian underground coal mines. K-4-10 ring-type valves are in particularly short supply; maintenance engineers have been forced to modify the compresors. Initially, Bulgarian KP-3.1 valves with direct air streaming replaced the K-4-10; these were later replaced by PIK-220 and PIK-220A valves. Tests on overhauled compressors have shown that replacing the KP-3.1 with the PIK-220 or PIK-220A can result in a saving of up to 100,000 kWh of electricity per compressor. Details of reconstruction and testing of piston compressors are included. 10 refs.

Thermodynamic Model and Experimental Study of Oil-free Scroll Compressor

Science.gov (United States)

Peng, Bin; Zhao, Shengxian; Li, Yaohong

2017-10-01

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.

An Optimal Design Method of Centrifugal Compressors in Consideration of the Efficiency and the Noise

International Nuclear Information System (INIS)

Ha, K. G.; Sung, S. M.; Kang, S. H.

2007-01-01

A centrifugal compressor is a principal part of the fuelcell vehicles, aircraft and home appliances. Therefore not only efficiency but also compact size and a low operation RPM for noise reducing turn into important criteria of centrifugal compressors design. But those criteria are in conflict each other often. In the case of a RPM in particular, it is profitable to lower the RPM for a noise reduction and an endurance. But for a compact size and a light weight, the reverse has a beneficial effect undoubtedly. So it is necessary to introduce a new optimization concept in the centrifugal compressor design. An one dimensional optimal design method for the centrifugal compressor considering a impeller, a vaneless diffuser and a volute at a time is described. The new optimization process and underlying design methods of centrifugal compressors and some optimal design results are included in the paper

Description of Supercritical CO{sub 2} Compressor Experiment Loop

Energy Technology Data Exchange (ETDEWEB)

Lee, Je Kyoung; Lee, Jeong Ik; Ahn, Yoonhan; Kim, Seong Gu [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Cha, Je Eun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

The full scope of SCIEL project is to demonstrate high efficiency with simple recuperated cycle layout or recompressing layout, which the final cycle layout will be determined by the obtained compressor performance data. As a part of SCIEL project, S-CO{sub 2} compressor experiment facility has been constructed in KAERI. In this paper, current status of S-CO{sub 2} compressor experiment loop will be reviewed. With the growing interest in developing an advanced nuclear power plant, power conversion cycle innovation has been the part of this effort to secure high economics and enhanced safety. One of the main activities of power conversion cycle innovation is the development of Supercritical CO{sub 2} Brayton cycle technology. S-CO{sub 2} Brayton cycle concept was suggested in 1960s but the development and realization of the technology has been delayed up to now. In Korea, KAIST, KAERI and POSTECH are conducting research and development of Korean S-CO{sub 2} Brayton cycle technology by erecting the Supercritical CO{sub 2} Integral Experiment Loop (SCIEL)

Modeling of flexible reciprocating compressor considering the crosshead subsidence

Science.gov (United States)

Xue, Xiaogang; Liu, Shulin; Sun, Xin

2018-01-01

Crank-slider mechanisms are important parts of heavy duty machines, including reciprocating compressors, combustion motors. This paper targets on the dynamic response of the crosshead in a reciprocating compressor, taking into consideration the crosshead deviation from the original level. The traditional model of the compressor is usually a slider-mechanism system without considering the deflection of the crosshead, thus neglecting the influence of the piston rod, which has some flexible features. In this paper, a rigid-flexible model of slider-crank is described theoretically, using the commercial software MATLAB, where the crank, connecting rod and crosshead are treated as rigid bodies, while the piston rod connected to the crosshead is considered as a flexible body. The dynamic response of the mechanism with the crosshead subsidence is discussed detailedly in this paper. After calculated theoretically, the MATLAB simulation showed that the dynamic response of the crosshead will be greatly influenced if the crosshead subsided from the original level. Also, the influence of the crosshead subsidence was also investigated, and some extra vibration of the crosshead arises.

40 CFR 61.242-3 - Standards: Compressors.

Science.gov (United States)

2010-07-01

... at a pressure that is greater than the compressor stuffing box pressure; or (2) Equipped with a...) Equipped with a system that purges the barrier fluid into a process stream with zero VHAP emissions to...

Gas dynamic design of the pipe line compressor with 90% efficiency. Model test approval

Science.gov (United States)

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

2015-08-01

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.

Kinetics of a gas adsorption compressor

Science.gov (United States)

Chan, C. K.; Tward, E.; Elleman, D. D.

1984-01-01

Chan (1981) has suggested that a process based on gas adsorption could be used as a means to drive a Joule-Thomson (J-T) device. The resulting system has several advantages. It is heat powered, it has no sealing, there are no mechanical moving parts, and no active control is required. In the present investigation, a two-phase model is used to analyze the transients of a gas adsorption compressor. The modeling of the adsorption process is based on a consideration of complete thermal and mechanical equilibrium between the gaseous phase and the adsorbed gas phase. The experimental arrangement for two sets of kinetic tests is discussed, and data regarding the experimental results are presented in graphs. For a theoretical study, a two-phase model was developed to predict the transient behavior of the compressor. A computer code was written to solve the governing equations with the aid of a standard forward marching predictor-corrector method.

Compressor Part II: Volute Flow Predictions

Directory of Open Access Journals (Sweden)

Yu-Tai Lee

1999-01-01

Full Text Available A numerical method that solves the Reynolds-averaged Navier-Stokes equations is used to study an inefficient component of a shipboard air-conditioning HCFC-124 compressor system. This high-loss component of the centrifugal compressor was identified as the volute through a series of measurements given in Part I of the paper. The predictions were made using three grid topologies. The first grid closes the connection between the cutwater and the discharge diffuser. The other two grids connect the cutwater area with the discharge diffuser. Experiments were performed to simulate both the cutwater conditions used in the predictions. Surface pressures along the outer wall and near the inlet of the volute were surveyed for comparisons with the predictions. Good agreements between the predicted results and the measurements validate the calculations. Total pressure distributions and flow stream traces from the prediction results support the loss distribution through the volute. A modified volute configuration is examined numerically for further loss comparison.

Flow and pressure characteristics within a screw compressor

Energy Technology Data Exchange (ETDEWEB)

Guerrato, D; Nouri, J M; Stosic, N; Arcoumanis, C [Centre for Energy and the Environment, School of Engineering and Mathematical Sciences, City University, Northampton Square, London, EC1V OHB (United Kingdom)

2007-10-15

The angle-resolved mean and turbulence characteristics of the axial air flow inside a screw compressor with both male and female rotors have been measured, using a laser Doppler velocimeter (LDV) with high spatial and temporal resolution at different radial and axial locations for speeds of 800-1600 rpm, discharge pressures of 1-1.6 bar and discharge temperatures of 33-90{sup 0}C. The velocity measurements were performed through a special transparent window fixed near the discharge port. The results confirmed the ability of the LDV technique to characterise the flow inside the compressor working chamber; an angular resolution of 1.5{sup 0} was able to fully describe the velocity field within the machine. The flow variation between the different working chambers was established as well as the spatial variation of the axial mean velocity and turbulence velocity fluctuation within the working chamber. The effect of discharge port opening on the axial mean and RMS velocities was found to be significant near the leading edge of the rotors causing an increase in the mean and RMS velocities of the order of 4.2V{sub p} in mean (where V{sub p} is the axial pitched velocity) for male rotor and 5.4V{sub p} for, female rotor and this effect is less pronounced on the flow near the root of the rotor. Moreover, to obtain a better understanding of the flow motion, a high sampling rate pressure transducer was used to provide the internal angular static pressure variation. These measurements are used to validate the in-house CFD model of the fluid flow within twin screw compressors which, in turn, allows reliable optimisation of various compressor designs.

The Application of the Probabilistic Collocation Method to a Transonic Axial Flow Compressor

NARCIS (Netherlands)

Loeven, G.J.A.; Bijl, H.

2010-01-01

In this paper the Probabilistic Collocation method is used for uncertainty quantification of operational uncertainties in a transonic axial flow compressor (i.e. NASA Rotor 37). Compressor rotors are components of a gas turbine that are highly sensitive to operational and geometrical uncertainties.

Hybrid ANN–PLS approach to scroll compressor thermodynamic performance prediction

International Nuclear Information System (INIS)

Tian, Z.; Gu, B.; Yang, L.; Lu, Y.

2015-01-01

In this paper, a scroll compressor thermodynamic performance prediction was carried out by applying a hybrid ANN–PLS model. Firstly, an experimental platform with second-refrigeration calorimeter was set up and steady-state scroll compressor data sets were collected from experiments. Then totally 148 data sets were introduced to train and verify the validity of the ANN–PLS model for predicting the scroll compressor parameters such as volumetric efficiency, refrigerant mass flow rate, discharge temperature and power consumption. The ANN–PLS model was determined with 5 hidden neurons and 7 latent variables through the training process. Ultimately, the ANN–PLS model showed better performance than the ANN model and the PLS model working separately. ANN–PLS predictions agree well with the experimental values with mean relative errors (MREs) in the range of 0.34–1.96%, correlation coefficients (R 2 ) in the range of 0.9703–0.9999 and very low root mean square errors (RMSEs). - Highlights: • Hybrid ANN–PLS is utilized to predict the thermodynamic performance of scroll compressor. • ANN–PLS model is determined with 5 hidden neurons and 7 latent variables. • ANN–PLS model demonstrates better performance than ANN and PLS working separately. • The values of MRE and RMSE are in the range of 0.34–1.96% and 0.9703–0.9999, respectively

Axial-Centrifugal Compressor Program

Science.gov (United States)

1975-10-01

Assembly . .. . .... ..... 33 5 Tie Bolt...... .. .. .. .. . *.. .. .. .. .. .. ... 34 6 Axial Compressor Rotor Assembly Runouts . . .. . 34 7 CCV Blow...1.796 Impeller Slip Factor ’Ce2/U 2 ) .91 Impeller Wheel Speed ft/sec 1992.2 Impellet ’.ip Radius in. 3.780 Blade Tip Metal Angle- deg 0 Numbec of Blades...test item to the next Phase V component test. The test vehicle final balance levels and rotor runouts were normal at teardown, and no rubsI were

Centrifugal Compressor Surge Margin Improved With Diffuser Hub Surface Air Injection

Science.gov (United States)

Skoch, Gary J.

2002-01-01

Aerodynamic stability is an important parameter in the design of compressors for aircraft gas turbine engines. Compression system instabilities can cause compressor surge, which may lead to the loss of an aircraft. As a result, engine designers include a margin of safety between the operating line of the engine and the stability limit line of the compressor. The margin of safety is typically referred to as "surge margin." Achieving the highest possible level of surge margin while meeting design point performance objectives is the goal of the compressor designer. However, performance goals often must be compromised in order to achieve adequate levels of surge margin. Techniques to improve surge margin will permit more aggressive compressor designs. Centrifugal compressor surge margin improvement was demonstrated at the NASA Glenn Research Center by injecting air into the vaned diffuser of a 4:1-pressure-ratio centrifugal compressor. Tests were performed using injector nozzles located on the diffuser hub surface of a vane-island diffuser in the vaneless region between the impeller trailing edge and the diffuser-vane leading edge. The nozzle flow path and discharge shape were designed to produce an air stream that remained tangent to the hub surface as it traveled into the diffuser passage. Injector nozzles were located near the leading edge of 23 of the 24 diffuser vanes. One passage did not contain an injector so that instrumentation located in that passage would be preserved. Several orientations of the injected stream relative to the diffuser vane leading edge were tested over a range of injected flow rates. Only steady flow (nonpulsed) air injection was tested. At 100 percent of the design speed, a 15-percent improvement in the baseline surge margin was achieved with a nozzle orientation that produced a jet that was bisected by the diffuser vane leading edge. Other orientations also improved the baseline surge margin. Tests were conducted at speeds below the

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

CERN Document Server

Yoon, Se Young; Allaire, Paul E

2013-01-01

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...

Compressor noise control begins with design--Part 2

International Nuclear Information System (INIS)

Frank, L.

1993-01-01

Reduction of noise pollution at gas compressor stations associated with natural gas pipelines and distribution systems, has long been a complex problem. Specified noise levels of individual components tell nothing of the overall system when it is installed and placed in a site-specific setting. Further, testing for compliance performance guarantees is virtually impossible to conduct at a distant location because one cannot distinguish among various contributing noise sources. This paper develops a plan for calculating an estimate of sound generation from a compressor station and the methods for controlling and measuring sounds of individual components. It also classifies the types of noise and gives various methods of dealing with each noise type

Active unsteady aerodynamic suppression of rotating stall in an incompressible flow centrifugal compressor with vaned diffuser

Science.gov (United States)

Lawless, Patrick B.; Fleeter, Sanford

1991-01-01

A mathematical model is developed to analyze the suppression of rotating stall in an incompressible flow centrifugal compressor with a vaned diffuser, thereby addressing the important need for centrifugal compressor rotating stall and surge control. In this model, the precursor to to instability is a weak rotating potential velocity perturbation in the inlet flow field that eventually develops into a finite disturbance. To suppress the growth of this potential disturbance, a rotating control vortical velocity disturbance is introduced into the impeller inlet flow. The effectiveness of this control is analyzed by matching the perturbation pressure in the compressor inlet and exit flow fields with a model for the unsteady behavior of the compressor. To demonstrate instability control, this model is then used to predict the control effectiveness for centrifugal compressor geometries based on a low speed research centrifugal compressor. These results indicate that reductions of 10 to 15 percent in the mean inlet flow coefficient at instability are possible with control waveforms of half the magnitude of the total disturbance at the inlet.

Experimental Investigation of Factors Influencing Operating Rotor Tip Clearance in Multistage Compressors

Directory of Open Access Journals (Sweden)

Reid A. Berdanier

2015-01-01

Full Text Available An analysis of compressor rotor tip clearance measurements using capacitance probe instrumentation is discussed for a three-stage axial compressor. Thermal variations and centrifugal effects related to rotational speed changes affect clearance heights relative to the assembled configuration. These two primary contributions to measured changes are discussed both independently and in combination. Emphasis is given to tip clearance changes due to changing loading condition and at several compressor operating speeds. Measurements show a tip clearance change approaching 0.1 mm (0.2% rotor span when comparing a near-choke operating condition to a near-stall operating condition for the third stage. Additional consideration is given to environmental contributions such as ambient temperature, for which changes in tip clearance height on the order of 0.05 mm (0.1% rotor span were noted for temperature variations of 15°C. Experimental compressor operating clearances are presented for several temperatures, operating speeds, and loading conditions, and comparisons are drawn between these measured variations and predicted changes under the same conditions.

Modeling the Isentropic Head Value of Centrifugal Gas Compressor using Genetic Programming

Directory of Open Access Journals (Sweden)

Safiyullah Ferozkhan

2016-01-01

Full Text Available Gas compressor performance is vital in oil and gas industry because of the equipment criticality which requires continuous operations. Plant operators often face difficulties in predicting appropriate time for maintenance and would usually rely on time based predictive maintenance intervals as recommended by original equipment manufacturer (OEM. The objective of this work is to develop the computational model to find the isentropic head value using genetic programming. The isentropic head value is calculated from the OEM performance chart. Inlet mass flow rate and speed of the compressor are taken as the input value. The obtained results from the GP computational models show good agreement with experimental and target data with the average prediction error of 1.318%. The genetic programming computational model will assist machinery engineers to quantify performance deterioration of gas compressor and the results from this study will be then utilized to estimate future maintenance requirements based on the historical data. In general, this genetic programming modelling provides a powerful solution for gas compressor operators to realize predictive maintenance approach in their operations.

Supersonic compressor

Science.gov (United States)

Roberts, II, William Byron; Lawlor, Shawn P.; Breidenthal, Robert E.

2016-04-12

A supersonic compressor including a rotor to deliver a gas at supersonic conditions to a diffuser. The diffuser includes a plurality of aerodynamic ducts that have converging and diverging portions, for deceleration of gas to subsonic conditions and then for expansion of subsonic gas, to change kinetic energy of the gas to static pressure. The aerodynamic ducts include vortex generating structures for controlling boundary layer, and structures for changing the effective contraction ratio to enable starting even when the aerodynamic ducts are designed for high pressure ratios, and structures for boundary layer control. In an embodiment, aerodynamic ducts are provided having an aspect ratio of in excess of two to one, when viewed in cross-section orthogonal to flow direction at an entrance to the aerodynamic duct.

Optimization of the working process of the axial compressor according to the criterion of efficiency

Science.gov (United States)

Baturin, O. V.; Popov, G. M.; Goryachkin, E. S.; Novikova, Yu D.

2017-01-01

The paper shows search results of the optimal shape of low pressure compressor blades of the industrial gas turbine plant using methods of computational fluid dynamics and multicriteria methods of mathematical optimization. The essence of the methods is that an increase in compressor efficiency should be achieved by increasing the degree of compression up to 2%, and reducing the air flow to 8% relative to basic engine parameters. However, the compressor design elements should be retained as maximally unchanged as possible. During the work, the calculation model of the workflow in the test compressor has been developed and verified in the NUMECA software package, the automated algorithm of the blades shape change has been also developed using a small number of variables, while maintaining its stress-strain state. It allows reducing the number of changeable variables more than twofold. As the result of this study, the option of compressor performance was found, which can increase its efficiency by 1.3% (abs.).

LA DINÁMICA DE FLUIDOS COMPUTACIONAL, SU APLICACIÓN AL ESTUDIO DE LAS CARACTERÍSTICAS DE UN INTERCAMBIADOR DE TUBOS TÉRMICOS

Directory of Open Access Journals (Sweden)

David Fernández Rivas

2005-09-01

Full Text Available Para el estudio y el diseño de un intercambiador de calor del tipo Termosifón se emplea por primera vez enCuba una novedosa técnica de modelación numérica, la Dinámica de Fluidos Computacional, uso quepudiera ahorrar al país numerosos recursos. Este trabajo continua, con nuevos aportes, una largainvestigación que ha tenido como objetivo central, la instalación de tubos térmicos termosifón (ITTT. Lasimulación computacional, es una poderosa herramienta que se emplea para conocer parámetros de interésen la operación de dicha instalación. Se trabaja con programas de Dinámica de Fluidos Computacional(DFC para acortar el tiempo de experimentación y ahorrar recursos materiales y humanos durante elestudio de diferentes variantes de arreglos geométricos de los tubos térmicos. Se logran conocer lasparticularidades que los diferentes arreglos de tubos introducen al proceso de intercambio de calor. Esteresultado brinda una importante contribución para la futura construcción de un termosifón a escalaindustrial. Esta investigación ha suscitado mucho interés por lo que pudiera significar para la eficiencia de lacaldera las nuevas condiciones impuestas por la quema de combustible cubano.Palabras Claves: Dinámica de Fluidos Computacional, Tubos térmicos, termosifón.__________________________________________________________________________AbstractThe Computational Fluids Dynamic it is used for studying a thermosyphon heat exchanger like a noveltechnique of numeric modeling, for the first time in Cuba. This technique could save a lot of resources. Thiswork is the continuation of a long research in the heat pipes technology. Working with Computational FluidsDynamic (DFC programs, consumes less time in the experimentation and allows saving material andhuman resources for these studies. It is possible to know many particularities of different geometries of tubesarrangements. This investigation will guarantee a future thermosyphon

More Options for the NLC Bunch Compressors (LCC-0035)

International Nuclear Information System (INIS)

Emma, P.

2004-01-01

The present bunch compressor design for the NLC allows control of the final bunch length by way of changes to the horizontal betatron phase advance of the 180 o -turnaround arc. This adjustability requirement significantly constrains the design and cost optimization of the system and excludes the possibility of using permanent magnet quadrupoles in the arc. To relieve this constraint, and to avoid the very strong arc focusing required at the upper limits of the bunch length range, we explore an option of bunch length control using the first compressor stage, with the arc optics fixed

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.

2010-06-15

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.

Aeroacoustic Simulation for NASA CC3 Centrifugal Compressor Operating at off Design Condition

Directory of Open Access Journals (Sweden)

Alqaradawi Mohamed

2016-01-01

Full Text Available This paper covers the characterization of the acoustic noise and the unsteady flow field of a high speed centrifugal compressor NASA CC3. In order to accurately predict the noise, all analyses are carried out through the use of Large Eddy Simulation and Ffowcs Williams–Hawkings model for noise prediction. The relative effect of hub cavity on flow characteristics and sound levels is investigated, for a compressor stage with a total pressure ratio equal to 4, working from surge to near choke condition. In comparison with the experimental results from literature, the predicted compressor performance and flow field are predicted well. The hub cavity flow effect on the compressor aeroacoustic generated noise is shown in the paper. The unsteady static pressure and sound pressure levels are compared not only at different location but also for design and off design operating points. The internal flow results inside the hub cavity are presented at surge, design and near choke points. The conclusion is that the cavity effect of the centrifugal compressor cannot be ignored in the numerical prediction of aerodynamic generated noise. The impeller back plate of the rotor experiences a strong pressure fluctuation, which is maxima at the impeller outer radius for all operating point, but higher pressure values at the surge point.

Experimental investigation of hinged and spring loaded rolling piston compressors pertaining to a turbo rotary engine

International Nuclear Information System (INIS)

Okur, Melih; Akmandor, Ibrahim Sinan

2011-01-01

Hinged rolling piston compressor of a new thermodynamic cycle Pars engine promises high performance figures such as single stage high compression levels and higher volume flow discharge with competitively low input power and torque. The pumping characteristic of the present engine compressor unit has been increased by the implementation of a spring less vane configuration. The reciprocating vane which is usually operated by spring compression in air conditioning and refrigeration unit has been replaced by a hinge vane mechanism. At high speeds, the conventional spring loaded vane which is forced against the eccentrically moving rotor periphery does disconnect and starts rocking. With the new configuration, this mishap has been eliminated and subsequently resulting compressor pressure leaks have been avoided. Compressor experiments have been carried out at predetermined rotor speeds and compressed volume flow amounts and required shaft powers have been measured and derived accordingly. Experimentally determined pressure-volume relations have been compared with isentropic, isothermal, isochoric compressions as well as isobaric process. It is seen that at lower speeds, hinged vane compression is half way between isentropic and isochoric compressions whereas at high speed the compression process approaches further isochoric compression behavior. The isentropic compression efficiency of the hinged vane compressor is around 85% for pressures reaching 9 atm. - Research highlights: → Volume flow rate of rotary vane compressor unit has been increased by a hinged vane mechanism. → Hinged compressor pressure output is almost twice the performance of a spring loaded compressor. → The slipping and rocking of the spring loaded vane against the rolling piston have been eliminated.

Refrigeration compressor for the mobile application; Kaeltemittelverdichter fuer den mobilen Einsatz

Energy Technology Data Exchange (ETDEWEB)

Hagenlocher, T. [Bock GmbH und Co. Kaeltemaschinenfabrik, Frickenhausen (Germany)

2000-06-01

The mobile use of cooling air conditioning systems is increasingly important. Main component of this system is the refrigeration compressor. The special requirement for the compressor as well for the resulting boundary conditions are discussed. (orig.) [German] Der mobile Einsatz von Kaelte- und Klimaanlagen gewinnt zunehmend an Bedeutung. Wichtigste Komponente dieser Anlage ist der Kaeltemittelverdichter. Die speziellen Anforderungen an den Verdichter sowie an die daraus resultierenden Randbedingungen werden dargestellt. (orig.)

La flora como recurso terapéutico : el caso de los extractos fluidos de los Laboratorios Codex en México

OpenAIRE

Hersch Martínez, Paul

2008-01-01

Entre las fuentes para una historia social de la terapéutica en México, es pertinente analizar la producción de sus laboratorios farmacéuticos, aún cuando reflejen de manera limitada e indirecta la práctica terapéutica misma. Una primera aproximación a los extractos fluidos de los Laboratorios Codex producidos en el segundo cuarto del siglo XX, permite destacar la diversidad florística de la materia prima empleada en ellos y sus propiedades terapéuticas, avaladas entonces por las autoridades ...

Aspirated Compressors for High Altitude Engines, Phase I

Data.gov (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...

Reverse-Tangent Injection in a Centrifugal Compressor

Science.gov (United States)

Skoch, Gary J.

2007-01-01

Injection of working fluid into a centrifugal compressor in the reverse tangent direction has been invented as a way of preventing flow instabilities (stall and surge) or restoring stability when stall or surge has already commenced. The invention applies, in particular, to a centrifugal compressor, the diffuser of which contains vanes that divide the flow into channels oriented partly radially and partly tangentially. In reverse-tangent injection, a stream or jet of the working fluid (the fluid that is compressed) is injected into the vaneless annular region between the blades of the impeller and the vanes of the diffuser. As used here, "reverse" signifies that the injected flow opposes (and thereby reduces) the tangential component of the velocity of the impeller discharge. At the same time, the injected jet acts to increase the radial component of the velocity of the impeller discharge.

Chemical changes in well fluids from the Los Humeros geothermal field: Evidences for deep recharge; Cambios quimicos en fluidos de pozos del campo geotermico de Los Humeros: Evidencia de recarga profunda

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Flores Armenta, Magaly [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Tovar Aguado, Rigoberto [Comision Federal de Electricidad (Mexico)

2008-07-15

Fluid (water and steam) chemical changes over time were studied in 20 wells in the Los Humeros, Mexico, geothermal field for the purpose of correlating such changes with physical processes occurring in the reservoir due to exploitation. Most wells (except well H-1) produce high-enthalpy fluids with almost no liquid, making gas geochemistry important in this field. Liquid-phase studies include fluid classification, determination of water-rock equilibrium state, and reservoir-temperature estimates. Changes in gas composition through time were studied using the Fischer-Tropsch (FT) reaction and the combined balance pyrite-hematite-magnetite (HSH2) as the buffer controlling H{sub 2}S fluid concentration. Data for most wells from 1987-1995 and 2000-2005 indicate the presence of deeper-fluid recharge, with maximum temperatures occurring in 1994-95 and 2005. The estimated temperature in well H-1 in 1994 was 305 degrees Celsius and the estimated temperature in well H-7 was 338 degrees Celsius in 1995. Temperature estimations from 2005 data were 222 degrees Celsius in well H-1D and 350 degrees Celsius in well H-7. These results are considered caused by the entrance of deeper fluids due to the increase of secondary permeability, which in turn is related to the seismicity increase in the zone. At the same time, re-injection returns in the steam phase were identified in well discharges during 1995-2000 by means of the FT-HSH2 diagram. [Spanish] Se realizo un estudio de los cambios quimicos ocurridos en fluidos (liquido y vapor) de veinte pozos del campo geotermico de Los Humeros, Pue., Mexico, con objeto de investigar la ocurrencia de procesos del yacimiento relacionados con la explotacion. La mayoria de los pozos (excepto el pozo H-1) se caracterizan por producir descargas de alta entalpia con escasa produccion de liquido, por lo que en este campo la geoquimica de gases juega un papel importante. El estudio de la fase liquida incluyo la clasificacion de los fluidos, la

FOREWORD: 9th International Conference on Compressors and their Systems

Science.gov (United States)

Kovacevic, Ahmed, Prof

2015-08-01

The 9th International Conference on Compressors and their Systems will be held in London from 5th - 9th September 2015, and as its Chairman, it is my pleasure to welcome you. This series of conferences started in 1999 organised by the Fluid Machinery Group of the Institution of Mechanical Engineers (IMechE) but since 2009 it has been managed by City University London in conjunction with the IMechE and the Institute of Refrigeration, both of which have been very proactive in promoting it. The Organising committee is grateful for their support and continued encouragement. This year, after rigorous reviewing, we have accepted over 80 technical papers for publication, the highest number in the conference history. On behalf of the organising committee I would like to thank the reviewers for their hard work and assistance. In addition to the main technical sessions, this year we have introduced a third day, specifically for Industry, to consider technology, business and market drivers on compressor developments. The traditional series of the short courses is this year continuing prior to the main event with the second short course/forum on Computational Fluid Dynamics in rotating positive displacement machines. I would like to extend my special thanks to our main sponsors, Holroyd PTG, Howden and Kapp Niels for their continuing support for the conference. With their generous contributions we have managed to keep the conference fees at the same level as in 2013, despite extending it to 3 days and holding it outside the University this year. The welcome reception on Sunday 6th September 2015 is dedicated to the celebration of the 20th anniversary of the Centre for Positive Displacement Compressors Technology which was formed at City University in 1995 with support from the Royal Academy of Engineering and Holroyd; its main aim being to assist British manufacturers of screw compressors. The Centre has since made a significant impact on the screw compressor world, far beyond

Thermal performance analysis of reciprocating compressor with stepless capacity control system

International Nuclear Information System (INIS)

Bin, Tang; Yuanyang, Zhao; Liansheng, Li; Guangbin, Liu; Le, Wang; Qichao, Yang; Haiping, Xu; Feng, Zhu; Wenhui, Meng

2013-01-01

On the basic principle of stepless capacity control system for large reciprocating compressor, the thermal cycle was analyzed. The equations for the process of suction, reverse flow, compression, discharge and expansion of clearance gas were established. According to these equations, p–V diagrams at various situations were simulated. An experimental platform was setup and the compressor with designed stepless capacity control system run well. The experimental results show that the capacity of compressor can be regulated steplessly, and the motor power is reduced proportionally with respect to the reduction of capacity. During the suction process, both the flow resistance of valve and the pressure fluctuation in cylinder can be reduced by opening the suction valves with the actuators. The simulated and experimental results showed good coincidence. The clearance volume and valve clearance Mach number had a negative influence on the thermal performance of compressor with stepless capacity control system. -- Highlights: ► Flow resistance of valve can be reduced and pressure fluctuation can be reduced. ► Equivalent Mach number of reverse flow is much higher than that of suction process. ► Response of stepless capacity control system is important for regulation accuracy. ► Clearance and valve clearance Mach number have influence on thermal performance

Study of High Efficiency Flow Regulation of VIGV in Centrifugal Compressor

Directory of Open Access Journals (Sweden)

Chunjun Ji

2016-01-01

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.

Performance of vapor compression systems with compressor oil flooding and regeneration

Energy Technology Data Exchange (ETDEWEB)

Bell, Ian H.; Groll, Eckhard A.; Braun, James E. [Purdue University, Department of Mechanical Engineering, 140 S. Martin Jischke Drive, West Lafayette, IN 47906 (United States)

2011-01-15

Vapor compression refrigeration technology has seen great improvement over the last several decades in terms of cycle efficiency through a concerted effort of manufacturers, regulators, and research engineers. As the standard vapor compression systems approach practical limits, cycle modifications should be investigated to increase system efficiency and capacity. One possible means of increasing cycle efficiency is to flood the compressor with a large quantity of oil to achieve a quasi-isothermal compression process, in addition to using a regenerator to increase refrigerant subcooling. In theory, compressor flooding and regeneration can provide a significant increase in system efficiency over the standard vapor compression system. The effectiveness of compressor flooding and regeneration increases as the temperature lift of the system increases. Therefore, this technology is particularly well suited towards lower evaporating temperatures and high ambient temperatures as seen in supermarket refrigeration applications. While predicted increases in cycle efficiency are over 40% for supermarket refrigeration applications, this technology is still very beneficial for typical air-conditioning applications, for which improvements in cycle efficiency greater than 5% are predicted. It has to be noted though that the beneficial effects of compressor flooding can only be realized if a regenerator is used to exchange heat between the refrigerant vapor exiting the evaporator and the liquid exiting the condenser. (author)

AERODYNAMIC STUDIES IN THE STATIC COMPONENTS OF A CENTRIFUGAL COMPRESSOR STAGE

Directory of Open Access Journals (Sweden)

K. Srinivasa Reddy

2011-12-01

Full Text Available Aerodynamic studies in the static components of a centrifugal compressor stage were conducted using the computational fluid dynamics solver FLUENT. For the simulation study, a typical centrifugal compressor stage geometry with a flow coefficient of 0.053 was chosen, The study is confined to the static components of the centrifugal compressor stage, i.e., the crossover bend (180° U-bend, a radial cascade of return channel vanes, and the exit ducting (90° L-turn. The aerodynamic performance is reported in terms of total pressure loss coefficient, static pressure recovery coefficient, return channel vane surface static pressure distribution, and stage exit swirl angle distribution. The simulated flow through the static components covered five different operating conditions of the actual centrifugal compressor stage: the design point with 100% flow rate, and the off-design operating conditions with 70%, 80%, 110%, and 120% flow rates. The standard k-ε model was used with standard wall functions to predict the turbulence. A minimum total pressure loss coefficient was observed near 80% flow rate when the average flow angle at the U-bend inlet was 24°. Better static pressure recovery was observed with 70%, 80%, and 100% flow rates. The swirl angle distribution at the stage exit was recognized as satisfactory.

Experimental investigation of the discharge valve dynamics in a reciprocating compressor for trans-critical CO2 refrigeration cycle

International Nuclear Information System (INIS)

Ma Yuan; He Zhilong; Peng Xueyuan; Xing Ziwen

2012-01-01

The self-acting valve has a significant influence on the efficiency and reliability of the reciprocating compressor. In the trans-critical CO 2 cycle, the large density and high pressure difference across the valve cause serious bending and impact stresses in the valve, offering great challenges for successful valve design. Experimental investigation of the valve dynamics is required in order to design a self-acting valve with a high efficiency and long life span for the trans-critical CO 2 compressor. A semi-hermetic reciprocating compressor was developed for application in CO 2 refrigeration, and a test system was incorporated into the compressor performance test rig, with a focus on investigating the dynamics of the discharge valves. With the experimental results, the movement of the valve was discussed in detail for the trans-critical CO 2 compressor, allowing for the study of the thermodynamic performance of the compressor. While varying design parameters such as pressure ratio, valve lift, spring stiffness and compressor speed, the movement of the discharge valve in the reciprocating CO 2 compressor was measured in order to investigate the major factors that influence the valve dynamics. The average valve speed increased from 0.71 m/s to 0.81 m/s as the discharge pressure changed from 7.8 MPa to 12 MPa. The experimental methods and results discussed in this paper could provide useful information for both valve testing and the optimization of their reliability in trans-critical CO 2 compressors.

Technical Requirements and Principles for the Standards Development of the Key Parts for Rotor Air-conditioning Compressors

Institute of Scientific and Technical Information of China (English)

Sun Min; Wen Yun; Fan Zhangzeng

2011-01-01

ntroductionSince 2000,air-conditioning sales continues to grow,and the development of air-conditioning market makes a booming market of compressor.At the present time,compressor production rising all the way,and the sales steps up the new steps constantly.Tendency chart is shown in figure 1.Rotor compressor with its simple structure,small volume,light weight,easy processed mechanical parts,reliable operation and other excellent characteristics occupied the dominant position in the market.Compared with reciprocating compressor on the same application situation,decreased in the size by 40％～50％,weight was reduced by 40％～50％.But there were also disadvantages,mainly large friction loss,friction power consumption was about 10％of compressor's total power input.

Modelling of fluid flow and heat transfer in a reciprocating compressor

Science.gov (United States)

Tuhovcak, J.; Hejcik, J.; Jicha, M.

2015-08-01

Efficiency of reciprocating compressor is strongly dependent on several parameters. The most important are valve behaviour and heat transfer. Valves affect the flow through the suction and discharge line. Heat flow from the walls to working fluid increases the work of the cycle. Understanding of these phenomena inside the compressor is a necessary step in the development process. Commercial CFD tools offer wide range of opportunities how to simulate the flow inside the reciprocating compressor nowadays, however they are too demanding in terms of computational time and mesh creation. Several approaches using various correlation equation exist to describe the heat transfer inside the cylinder, however none of them was validated by measurements due to the complicated settings. The goal of this paper is to show a comparison between these correlations using in-house code based on energy balance through the cycle.

Enhancement of centrifugal compressor stable operation using an internal recirculation channel

Directory of Open Access Journals (Sweden)

Růžička M.

2016-12-01

Full Text Available Centrifugal compressors with a high pressure ratio are widely used in small aircraft turbine engines and turbocharges. At high rotational speeds they have a narrow stable operating region and the commonly used impellers with back swept blades are not able to ensure requested stability. In order to achieve a wider stable operating region, some other anti-surge measures can be used such as an Internal Recirculation Channel (IRC located in the inlet area of the compressor impeller. This paper analyses the influence of various IRC inlet slot geometries on air flow parameters. The flow velocity profiles downstream of the IRC outlet slot are evaluated and the influence of various channel configurations on compressor performance map is shown. Results from experiments as well as CFD simulations enable us to analyse the airflow in IRC and find out its most suitable geometry.

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...... and positional node, the model estimates the pressure and temperature of the hydrogen and liquid, the temperature of the compression chamber wall, and the amount of heat extracted from the hydrogen directly at the interface between the hydrogen and liquid, and through the wall. The results indicate......, fabrication, and control of the prototype is described in the presented work. The new compressor design has high potential to be used as an alternative to the conventional reciprocating compressors in hydrogen refueling stations, as it provides a simpler design with lower manufacturing costs, higher...

Study on the coupling performance of a turboexpander compressor applied in cryogenic reverse Brayton air refrigerator

International Nuclear Information System (INIS)

Yang, Shanju; Chen, Shuangtao; Chen, Xingya; Zhang, Xingqun; Hou, Yu

2016-01-01

Highlights: • Numerical simulations on expansion and compression processes were carried out. • A coupling model was built based on analysis and simulation and verified by test. • Relations and interactions among coupling parameters were quantitatively described. • When T_0_C = 0.39 MPa, the cooling capacity of refrigerator reached 221 W at 129.6 K. - Abstract: A small cryogenic reverse Brayton air refrigerator with turboexpander compressor (TEC) is presented in this study. Because of stable process, simple matching between expander and brake blower, and easy regulation, a turboexpander with brake blower is usually used in small reverse Brayton refrigerator. However, a turboexpander with brake blower just consumes and wastes the output energy during the enthalpy drop. In contrast, the output energy of TEC is absorbed by its coupled compressor for recycling. Thus when employing a TEC, the reverse Brayton refrigerator will achieve lower refrigeration temperature, larger cooling capacity and more effective energy use. TEC overall performance, which has an important impact on the refrigerator thermal performance, is mainly determined by the coupling between expander and compressor. In a TEC, the compressor and expander should seek balance among energy, rotating speed, mass flow rate and pressure, though restricted by individual working characteristics. The coupling relations among compressor efficiency, expander efficiency, compressor pressure ratio and expander expansion ratio are quite complex. In this study, theoretical coupling analysis between expander and compressor was conducted. The aerodynamic performances of compressor and expander were calculated using CFX simulation with SST model. The performance curves of compressor and expander were obtained through simulation results, which were validated by experimental data. Based on the coupling analysis and numerical simulations, the automatic coupling model between compression process and expansion process

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

2012-04-01

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.

Active surge control for variable speed axial compressors.

Science.gov (United States)

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

2014-09-01

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.

Simulation of Casing Treatments of a Transonic Compressor Stage

Directory of Open Access Journals (Sweden)

M. Hembera

2008-01-01

Full Text Available This article presents the study of casing treatments on an axial compressor stage for improving stability and enhancing stall margin. So far, many simulations of casing treatments on single rotor or rotor-stator configurations were performed. But as the application of casing treatments in engines will be in a multistage compressor, in this study, the axial slots are applied to a typical transonic first stage of a high-pressure 4.5-stage compressor including an upstream IGV, rotor, and stator. The unsteady simulations are performed with a three-dimensional time accurate Favre-averaged Navier-stokes flow solver. In order to resolve all important flow mechanisms appearing through the use of casing treatments, a computational multiblock grid consisting of approximately 2.4 million nodes was used for the simulations. The configurations include axial slots in 4 different variations with an axial extension ranging into the blade passage of the IGV. Their shape is semicircular with no inclination in circumferential direction. The simulations proved the effectiveness of casing treatments with an upstream stator. However, the results also showed that the slots have to be carefully positioned relative to the stator location.

Analytical model for an electrostatically actuated miniature diaphragm compressor

International Nuclear Information System (INIS)

Sathe, Abhijit A; Groll, Eckhard A; Garimella, Suresh V

2008-01-01

This paper presents a new analytical approach for quasi-static modeling of an electrostatically actuated diaphragm compressor that could be employed in a miniature scale refrigeration system. The compressor consists of a flexible circular diaphragm clamped at its circumference. A conformal chamber encloses the diaphragm completely. The membrane and the chamber surfaces are coated with metallic electrodes. A potential difference applied between the diaphragm and the chamber pulls the diaphragm toward the chamber surface progressively from the outer circumference toward the center. This zipping actuation reduces the volume available to the refrigerant gas, thereby increasing its pressure. A segmentation technique is proposed for analysis of the compressor by which the domain is divided into multiple segments for each of which the forces acting on the diaphragm are estimated. The pull-down voltage to completely zip each individual segment is thus obtained. The required voltage for obtaining a specific pressure rise in the chamber can thus be determined. Predictions from the model compare well with other simulation results from the literature, as well as to experimental measurements of the diaphragm displacement and chamber pressure rise in a custom-built setup

Refrigerator with variable capacity compressor and cycle priming action through capacity control and associated methods

Science.gov (United States)

Gomes, Alberto Regio; Litch, Andrew D.; Wu, Guolian

2016-03-15

A refrigerator appliance (and associated method) that includes a condenser, evaporator and a multi-capacity compressor. The appliance also includes a pressure reducing device arranged within an evaporator-condenser refrigerant circuit, and a valve system for directing or restricting refrigerant flow through the device. The appliance further includes a controller for operating the compressor upon the initiation of a compressor ON-cycle at a priming capacity above a nominal capacity for a predetermined or calculated duration.

Design of a 17.14 GHz quasi-optical pulse compressor

International Nuclear Information System (INIS)

Petelin, M. I.; Kuzikov, S. V.; Danilov, Yu. Yu.; Granatstein, V. L.; Nusinovich, G. S.

1999-01-01

A quasi-optical version of the ring cavity pulse compressor is considered. This concept is based on the coupling of the input wave to a whispering gallery mode of a barrel-like cavity due to helical corrugations of the cavity wall. Low-power tests of the prototype were carried out at 11.4 GHz and demonstrated reasonable agree-ment between experimental data and theoretical predictions. The design of a similar pulse compressor at 17.14 GHz compatible with the 17.14 GHz, 100 MW gyroklystron currently under development at the University of Maryland is presented

Parametric optimization of the MVC desalination plant with thermomechanical compressor

Science.gov (United States)

Blagin, E. V.; Biryuk, V. V.; Anisimov, M. Y.; Shimanov, A. A.; Gorshkalev, A. A.

2018-03-01

This article deals with parametric optimization of the Mechanical Vapour Compression (MVC) desalination plant with thermomechanical compressor. In this plants thermocompressor is used instead of commonly used centrifugal compressor. Influence of two main parameters was studied. These parameters are: inlet pressure and number of stages. Analysis shows that it is possible to achieve better plant performance in comparison with traditional MVC plant. But is required reducing the number of stages and utilization of low or high initial pressure with power consumption maximum at approximately 20-30 kPa.

Effect of self recirculation casing treatment on the performance of a turbocharger centrifugal compressor

Science.gov (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

An evaluation of 1D loss model collections for the off-design performance prediction of automotive turbocharger compressors

International Nuclear Information System (INIS)

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

2013-01-01

Single-zone modelling is used to assess different collections of impeller 1D loss models. Three collections of loss models have been identified in literature, and the background to each of these collections is discussed. Each collection is evaluated using three modern automotive turbocharger style centrifugal compressors; comparisons of performance for each of the collections are made. An empirical data set taken from standard hot gas stand tests for each turbocharger is used as a baseline for comparison. Compressor range is predicted in this study; impeller diffusion ratio is shown to be a useful method of predicting compressor surge in 1D, and choke is predicted using basic compressible flow theory. The compressor designer can use this as a guide to identify the most compatible collection of losses for turbocharger compressor design applications. The analysis indicates the most appropriate collection for the design of automotive turbocharger centrifugal compressors

Linear Resonance Compressor for Stirling-Type Cryocoolers Activated by Piezoelectric Stack-Type Elements

International Nuclear Information System (INIS)

Sobol, S; Grossman, G

2015-01-01

A novel type of a PZT- based compressor operating at mechanical resonance, suitable for pneumatically-driven Stirling-type cryocoolers was developed theoretically and built practically during this research. A resonance operation at relatively low frequency was achieved by incorporating the piezo ceramics into the moving part, and by reducing the effective piezo stiffness using hydraulic amplification. The detailed concept, analytical model and the test results of the preliminary prototype were reported earlier and presented at ICC17 [2]. A fine agreement between the simulations and experiments spurred development of the current actual compressor designed to drive a miniature Pulse Tube cryocooler, particularly our MTSa model, which operates at 103 Hz and requires an average PV power of 11 W, filling pressure of 40 Bar and a pressure ratio of 1.3. The paper concentrates on design aspects and optimization of the governing parameters. The small stroke to diameter ratio (about 1:10) allows for the use of a composite diaphragm instead of a clearance-seal piston. The motivation is to create an adequate separation between the working fluid and the buffer gas of the compressor, thus preventing possible contamination in the cryocooler. Providing efficiency and power density similar to those of conventional linear compressors, the piezo compressor may serve as a good alternative for cryogenic applications requiring extreme reliability and absence of magnetic field interference. (paper)

Thermal effect of lubricating oil in positive-displacement air compressors

International Nuclear Information System (INIS)

Valenti, Gianluca; Colombo, Luigi; Murgia, Stefano; Lucchini, Andrea; Sampietro, Andrea; Capoferri, Andrea; Araneo, Lucio

2013-01-01

The isentropic efficiency of positive-displacement compressors may be improved in order to follow an increasing demand for energy savings. This work analyzes the thermal effect of the lubricating oil presence in the air during compression with the scope of exploiting it as a thermal ballast to mitigate both the gas temperature rise and its compression work. The bibliographic review shows that other authors suggested that oil can have positive effects if properly injected. Here an energy balance analysis is executed with the scope of deriving relations for the gas–liquid compression in analogy with those typical for the gas-only compression and of confirming that ideally the liquid presence may have beneficial effects, making the gas–liquid compression even better than 1- and 2-time intercooled gas compressions. Given these positive results, a heat transfer analysis is conducted to model the thermal interaction between gas and oil droplets within a mid-size rotary vane air compressor. A droplet diameter of the order of 100 μm leads to large reductions of both temperature increase and compression work: air can exit the discharge port at a temperature as low as 60 °C and compression work can be lowered by 23–28% with respect to conventional compressors. Finally, a test rig is constructed and operated to investigate a large-flow and large-angle oil nozzle taken from the market showing that, at the operating conditions of a compressor, oil breaks up into small droplets and undefined structures with large exchange surfaces. -- Highlights: ► Exploitation of thermal effect of oil in gas compressors is assessed numerically. ► Oil in 100 μm-diameter droplets mitigates effectively the gas temperature rise. ► Discharge temperature and compression work result to be much smaller than typical. ► An experimental setup is used to investigate oil atomization via commercial nozzles. ► A tested nozzle creates fine oil droplets and structures at conditions of

Dual capacity compressor with reversible motor and controls arrangement therefor

Science.gov (United States)

Sisk, Francis J.

1980-12-02

A hermetic reciprocating compressor such as may be used in heat pump applications is provided for dual capacity operation by providing the crankpin of the crankshaft with an eccentric ring rotatably mounted thereon, and with the end of the connecting rod opposite the piston encompassing the outer circumference of the eccentric ring, with means limiting the rotation of the eccentric ring upon the crankpin between one end point and an opposite angularly displaced end point to provide different values of eccentricity depending upon which end point the eccentric ring is rotated to upon the crankpin, and a reversible motor in the hermetic shell of the compressor for rotating the crankshaft, the motor operating in one direction effecting the angular displacement of the eccentric ring relative to the crankpin to the one end point, and in the opposite direction effecting the angular displacement of the eccentric ring relative to the crankpin to the opposite end point, this arrangement automatically giving different stroke lengths depending upon the direction of motor rotation. The mechanical structure of the arrangement may take various forms including at least one in which any impact of reversal is reduced by utilizing lubricant passages and chambers at the interface area of the crankpin and eccentric ring to provide a dashpot effect. In the main intended application of the arrangement according to the invention, that is, in a refrigerating or air conditioning system, it is desirable to insure a delay during reversal of the direction of compressor operation. A control arrangement is provided in which the control system controls the direction of motor operation in accordance with temperature conditions, the system including control means for effecting operation in a low capacity direction or alternatively in a high capacity direction in response to one set, and another set, respectively, of temperature conditions and with timer means delaying a restart of the compressor

Approach to novel design of CO2 based centrifugal compressor

Directory of Open Access Journals (Sweden)

Kura Tomasz

2016-01-01

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

Multi-disciplinary design optimization and performance evaluation of a single stage transonic axial compressor

International Nuclear Information System (INIS)

Lee, Sae Il; Lee, Dong Ho; Kim, Kyu Hong; Park, Tae Choon; Lim, Byeung Jun; Kang, Young Seok

2013-01-01

The multidisciplinary design optimization method, which integrates aerodynamic performance and structural stability, was utilized in the development of a single-stage transonic axial compressor. An approximation model was created using artificial neural network for global optimization within given ranges of variables and several design constraints. The genetic algorithm was used for the exploration of the Pareto front to find the maximum objective function value. The final design was chosen after a second stage gradient-based optimization process to improve the accuracy of the optimization. To validate the design procedure, numerical simulations and compressor tests were carried out to evaluate the aerodynamic performance and safety factor of the optimized compressor. Comparison between numerical optimal results and experimental data are well matched. The optimum shape of the compressor blade is obtained and compared to the baseline design. The proposed optimization framework improves the aerodynamic efficiency and the safety factor.

Optimising the refrigeration cycle with a two-stage centrifugal compressor and a flash intercooler

Energy Technology Data Exchange (ETDEWEB)

Roeyttae, Pekka; Turunen-Saaresti, Teemu; Honkatukia, Juha [Lappeenranta University of Technology, Laboratory of Energy and Environmental Technology, PO Box 20, 53851 Lappeenranta (Finland)

2009-09-15

The optimisation of a refrigeration process with a two-stage centrifugal compressor and flash intercooler is presented in this paper. The two-stage centrifugal compressor stages are on the same shaft and the electric motor is cooled with the refrigerant. The performance of the centrifugal compressor is evaluated based on semi-empirical specific-speed curves and the effect of the Reynolds number, surface roughness and tip clearance have also been taken into account. The thermodynamic and transport properties of the working fluids are modelled with a real-gas model. The condensing and evaporation temperatures, the temperature after the flash intercooler, and cooling power have been chosen as fixed values in the process. The aim is to gain a maximum coefficient of performance (COP). The method of optimisation, the operation of the compressor and flash intercooler, and the method for estimating the electric motor cooling are also discussed in the article. (author)

A new Wankel-type compressor and vacuum pump

Science.gov (United States)

Garside, D. W.

2017-08-01

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.

Fuel efficiency, availability and compressor station configuration

Energy Technology Data Exchange (ETDEWEB)

Lubomirsky, Matt; Kurz, Rainer [Solar Turbines Inc., San Diego, CA (United States); Klimov, Pavel [Intergas Central Asia, Astana (Kazakhstan)

2009-12-19

Compressor stations play a very important role in the success of a gas pipeline design and a careful selection of centrifugal compressors and drivers are key aspects for the success of the project. The state of the art design available today for this equipment provides overall high thermodynamic performance and consequently minimizes installed power requirements and energy usage with significant savings on operating expenses during the economic life of the project For any application of machinery in a pipeline compression station, one of the key questions to answer is the number of units to install to meet the flow requirements of the pipeline. Depending on the load profile of the pipeline, the answers may look different. Other factors to consider include the fact that gas turbines can produce a significant amount of additional power at lower ambient temperatures. So, even for constant load of the pipeline, the relative load of the driver changes. In this paper, a typical transcontinental pipeline with multiple compressor stations is evaluated. The determination of the exact hydraulic behavior of the pipeline is part of the modeling effort. The site ambient conditions, with a significant swing in ambient temperatures are considered. The issue discussed in this paper evolves around the availability that can be achieved with various configurations, based on actually achieved reliability and availability numbers. The other large impact on operating costs, fuel consumption will be discussed. Here, the choice of the number of installed units has a distinct impact on annual fuel consumption, as well as the capacity of the pipeline during various scenarios. (author)

Establishing a Ballistic Test Methodology for Documenting the Containment Capability of Small Gas Turbine Engine Compressors

Science.gov (United States)

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

2009-01-01

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.

Virtual Training of Compressor Control Room, Phase I

Data.gov (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 training to...

Performance analysis of the reciprocating compressor with hydrocarbon refrigerant mixtures, R290/R600a

Energy Technology Data Exchange (ETDEWEB)

Kim, J.H.; Chung, Y.G.; Pak, H.Y. [Hanyang University, Seoul (Korea); Park, K.W. [LG Industrial Systems, Seoul (Korea)

1999-03-01

A performance analysis simulation program that can be applied to a hermetic reciprocating compressor with various refrigerants has been developed. For the numerical analysis, the passage of refrigerant in compressor is subdivided into control volumes. Instead of the ideal gas assumption, CSD equation of state is applied to calculate the thermodynamic properties of refrigerants. To verify the validity of developed program, the result has been compared with the experimental data served by the compressor supplier. The performance of each refrigerant and the possibility of direct application are estimated by applying R12, 134a, R290, R600a and R290/R600a mixture to an existing compressor. Also, parametric study for various crank rotating speeds and the mole fractions of refrigerant has been performed. 22 refs., 12 figs., 5 tabs.

Semi-supervised vibration-based classification and condition monitoring of compressors

Science.gov (United States)

Potočnik, Primož; Govekar, Edvard

2017-09-01

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.

Minimisation of pressure pulsations in the screw compressor discharge piping

Energy Technology Data Exchange (ETDEWEB)

Zaytsev, D. [Grasso GmbH Refrigeration Technology, Berlin (Germany). R and D Screw Compressors

2006-07-01

A problem of noise and vibration in the piping between the screw compressor and oil separator arises if the natural gas pulsations in the piping get in the resonance with the pulsations sent by the compressor. Several typical piping geometries such as a short and a long pipe with the open end and a short pipe with agglomerator have been studied to evaluate the natural frequency of the gas column. It was found that because of the wave reflection from the open pipe end the gas in such a pipe has several natural frequencies dependent on the sound speed and on the pipe length. Since the sound speed of various refrigerants differs significantly, the resonance pipe length will also vary strongly from one refrigerant to another. Hence, to avoid the resonance a separate examination for each refrigerant would be required at the compressor package design stage. Unlike open ended pipes, in the pipe with agglomerator the wave reflection at the agglomerator side is reduced. This allows using of one standard discharge pipe geometry resonance-free independent on the refrigerant. (orig.)

Composite hub/metal blade compressor rotor

Science.gov (United States)

Yao, S.

1978-01-01

A low cost compressor rotor was designed and fabricated for a small jet engine. The rotor hub and blade keepers were compression molded with graphite epoxy. Each pair of metallic blades was held in the hub by a keeper. All keepers were locked in the hub with circumferential windings. Feasibility of fabrication was demonstrated in this program.

Experimental and computational investigation of the NASA low-speed centrifugal compressor flow field

Science.gov (United States)

Hathaway, Michael D.; Chriss, Randall M.; Wood, Jerry R.; Strazisar, Anthony J.

1993-01-01

An experimental and computational investigation of the NASA Lewis Research Center's low-speed centrifugal compressor (LSCC) flow field was conducted using laser anemometry and Dawes' three-dimensional viscous code. The experimental configuration consisted of a backswept impeller followed by a vaneless diffuser. Measurements of the three-dimensional velocity field were acquired at several measurement planes through the compressor. The measurements describe both the throughflow and secondary velocity field along each measurement plane. In several cases the measurements provide details of the flow within the blade boundary layers. Insight into the complex flow physics within centrifugal compressors is provided by the computational fluid dynamics analysis (CFD), and assessment of the CFD predictions is provided by comparison with the measurements. Five-hole probe and hot-wire surveys at the inlet and exit to the impeller as well as surface flow visualization along the impeller blade surfaces provided independent confirmation of the laser measurement technique. The results clearly document the development of the throughflow velocity wake that is characteristic of unshrouded centrifugal compressors.

Numerical analysis of the transient flow in a scroll refrigeration compressor

Science.gov (United States)

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

2017-08-01

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.

INFLUÊNCIA DA TEMPERATURA NA REOLOGIA DE FLUIDOS DE PERFURAÇÃO PREPARADOS COM CARBOXIMETILCELULOSE, GOMA XANTANA E BENTONITA

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Klismeryane Costa de Melo

2013-10-01

Full Text Available O comportamento reológico dos fluidos de perfuração pode sofrer alterações ao longo da perfuração em função do gradiente de temperatura do poço. A degradação térmica sofrida por alguns aditivos utilizados como viscosificantes restringe a utilização da classe dependendo da temperatura a qual será exposto. Este trabalho apresenta um estudo sobre o comportamento reológico da Goma Xantana (GX, da Carboximetilcelulose (CMC e da Bentonita (BNT em função da temperatura. Os Modelos matemáticos de Ostwald de Waale e o de Herschel-Bulkley foram aplicados para determinar os parâmetros reológicos. O efeito da hidratação dos polímeros e da argila na reologia de soluções aquosas foram previamente estudados. A caracterização reológica foi realizada através de ensaios de reologia, utilizando sistema de cilindros coaxiais, para obtenção das curvas de fluxo. A reologia foi avaliada em função da temperatura para cada um dos aditivos utilizados. Os resultados mostraram que a CMC se solubiliza rapidamente em água, porém apresenta maior degradação quando exposta a temperatura mais elevada. A GX se mostrou apta para ser utilizada em formulações de fluidos que serão usados em poços com gradiente de temperatura mais elevados. A bentonita não apresentou alterações no comportamento reológico em função do gradiente de temperatura estudado.

Fluido-Dynamic and Electromagnetic Characterization of 3D Carbon Dielectrophoresis with Finite Element Analysis

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Rodrigo Martinez-Duarte

2008-12-01

Full Text Available The following work presents the fluido-dynamic and electromagnetic characterization of an array of 3D electrodes to be used in high throughput and high efficiency Carbon Dielectrophoresis (CarbonDEP applications such as filters, continuous particle enrichment and positioning of particle populations for analysis. CarbonDEP refers to the induction of Dielectrophoresis (DEP by carbon surfaces. The final goal is, through an initial stage of modeling and analysis, to reduce idea-to-prototype time and cost of CarbonDEP devices to be applied in the health care field. Finite Element Analysis (FEA is successfully conducted to model flow velocity and electric fields established by polarized high aspect ratio carbon cylinders, and its planar carbon connecting leads, immersed in a water-based medium. Results demonstrate correlation between a decreasing flow velocity gradient and an increasing electric field gradient toward electrodes’ surfaces which is optimal for selected CarbonDEP applications. Simulation results are experimentally validated in the proposed applications.

Design of energy saving monitoring system on isothermal oilless lubricated air compressor

Science.gov (United States)

Ma, S. N.; Liu, Q.; Xu, B. L.; Liu, Y.; Hu, F.

2017-10-01

This design introduces a kind of STM32F051C8T6 circuit monitoring system which is based on the ARM core. According to the operating principle of air compressor, the reduction of temperature and current is converted to save electricity and directly displayed, save electricity information stored at the same time, to achieve real-time monitoring air compressor energy saving effect in the process of operation.

Axial compressor gas path design for desensitization of aerodynamic performance and stability to tip clearance

Science.gov (United States)

Cevik, Mert

Tip clearance is the necessary small gap left between the moving rotor tip and stationary shroud of a turbomachine. In a compressor, the pressure driven flow through this gap, called tip clearance flow, has a major and generally detrimental impact on compressor performance (pressure ratio and efficiency) and aerodynamic stability (stall margin). The increase in tip clearance, either temporary during transient engine operations or permanent from wear, leads to a drop in compressor performance and aerodynamic stability which results in a fuel consumption increase and a reduced operating envelope for a gas turbine engine. While much research has looked into increasing compressor performance and stall margin at the design (minimum or nominal) tip clearance, very little attention has been paid for reducing the sensitivity of these parameters to tip clearance size increase. The development of technologies that address this issue will lead to aircraft engines whose performance and operating envelope are more robust to operational demands and wear. The current research is the second phase of a research programme to develop design strategies to reduce the sensitivity of axial compressor performance and aerodynamic stability to tip clearance. The first phase had focused on blade design strategies and had led to the discovery and explanation of two flow features that reduces tip sensitivity, namely increased incoming meridional momentum in the rotor tip region and reduction/elimination of double leakage. Double leakage is the flow that exits one tip clearance and enters the tip clearance of the adjacent blade instead of convecting downstream out of the rotor passage. This flow was shown to be very detrimental to compressor performance and stall margin. Two rotor design strategies involving sweep and tip stagger reduction were proposed and shown by CFD simulations to exploit these features to reduce sensitivity. As the second phase, the objectives of the current research

Conceptual Design of Automotive Compressor for Integrated Portable Air Conditioning System

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Ishak Muhammad Ikman

2017-01-01

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.

Effect of CuO nanolubricant on compressor characteristics and performance of LPG based refrigeration cycle: experimental investigation

Science.gov (United States)

Kumar, Ravinder; Singh, Jagdev; Kundal, Pankaj

2018-05-01

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%.

Effect of CuO nanolubricant on compressor characteristics and performance of LPG based refrigeration cycle: experimental investigation

Science.gov (United States)

Kumar, Ravinder; Singh, Jagdev; Kundal, Pankaj

2017-11-01

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%.

Experimental investigation on a high subsonic compressor cascade flow

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Zhang Haideng

2015-08-01

Full Text Available With the aim of deepening the understanding of high-speed compressor cascade flow, this paper reports an experimental study on NACA-65 K48 compressor cascade with high subsonic inlet flow. With the increase of passage pressurizing ability, endwall boundary layer behavior is deteriorated, and the transition zone is extended from suction surface to the endwall as the adverse pressure gradient increases. Cross flow from endwall to midspan, mixing of corner boundary layer and the main stream, and reversal flow on the suction surface are caused by corner separation vortex structures. Passage vortex is the main corner separation vortex. During its movement downstream, the size grows bigger while the rotating direction changes, forming a limiting circle. With higher incidence, corner separation is further deteriorated, leading to higher flow loss. Meanwhile, corner separation structure, flow mixing characteristics and flow loss distribution vary a lot with the change of incidence. Compared with low aspect-ratio model, corner separation of high aspect-ratio model moves away from the endwall and is more sufficiently developed downstream the cascade. Results obtained present details of high-speed compressor cascade flow, which is rare in the relating research fields and is beneficial to mechanism analysis, aerodynamic optimization and flow control design.

Static analysis of triple-effect adsorption refrigeration with compressor

Directory of Open Access Journals (Sweden)

Fumi Watanabe

2017-03-01

Full Text Available In order to improve the efficiency of the adsorption refrigeration cycle, this study proposes a triple-effect adsorption refrigeration cycle equipped with a compressor. This cycle can run in order to create a large variation in adsorbent concentration range by the compressor, even if there is little temperature variation in the desorption and adsorption processes. The objective of this study is to clarify the effect that regulating adsorption pressure using a compressor has on the adsorption refrigeration cycle, and to that end cycle efficiency was calculated using a static analysis based on a state of equilibrium. As a results from the simulation, the triple-effect cycles can operate by regulating adsorption pressure. Both COP and exergy efficiency can be improved by a factor of 1.2 if the cycled is regulated the adsorption pressure of each cycle rather than using a shared adsorption pressure. For heat sources in the temperature range of 70–100 °C, this method is superior in terms of COP and exergy efficiency. COP values of approximately 1.7–1.8 can be obtained, which is three times higher than single-effect cycles. The triple-effect cycles have one-third the SCE of single-effect cycles but about the same SCE as double-effect cycles.

Investigation on the electromagnetic centring technique in compressor with labyrinth seal structure

Science.gov (United States)

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

2017-08-01

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.

Diagnostics of Hydrogen-Containing Mixture Compression by a Two-Stage Piston Compressor with Cooling Demand Prediction

Directory of Open Access Journals (Sweden)

Tomáš Brestovič

2018-04-01

Full Text Available The present article describes the diagnostics of a compressor that is compressing a mixture of H2 and N2 on the basis of the results that were obtained by operational measurements of the flow rates and temperatures at selected compressor sites, as well as of the acoustic pressure levels during the full loading thereof. The obtained data were subsequently used to determine the limit conditions of the compressor operations in terms of the cooling capacity. A thermodynamic analysis of the compression of the H2/N2 gas mixture was carried out with subsequent heat and energy flow calculation and the determination of the minimum cooling water flow rate that is required to ensure the continuous compressor operations.

Performance Analysis of a Centrifugal Compressor for HFC-134a with aviation of Diffuser Vane Angle

International Nuclear Information System (INIS)

Park, Han Young; Chung, Jin Taek; Shin, You Hwan; Lee, Yoon Pyo; Kim, Kwang Ho; Cho, Yong Hun; Kim, Jong Seong

2007-01-01

Numerical simulation on the two-stage centrifugal compressor with Low Solidity Vaned Diffuser (LSVD) for HFC-134a turbo-chiller was performed using a commercial code. The comparative study with experimental results from other compressor was also investigated to testify the simulation schemes. The numerical analysis was separately simulated for each stage of the compressor and the effect of impeller-diffuser flow interaction was considered. Setting angle of the diffuser vane changed in the range of 15 .deg. and the effects on its variation were discussed in detail including the flow analysis in the passage of the compressor. The vane setting angle obtained from the preliminary design was slightly adjusted to the optimal value by the performance enhancement in terms of pressure recovery and flow characteristics

The UCOR pilot plant and the development of axial flow compressors

International Nuclear Information System (INIS)

Grant, W.

1984-01-01

This article discusses some of the mechanical aspects of the Uranium Enrichment Corporation of South Africa (Pty) Ltd. (UCOR) pilot plant. The most important mechanical components in a typical stage in the pilot plant, consists of a compressor which is used to compress the process gas mixture. After air cooling to almost room temperature, the mixture is fed through the separation elements. Other components are two pressure vessels connected to the compressor. The development and characteristics of the pilot plant is described in the article

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

Science.gov (United States)

Dietz, Robert O.; Kuenzig, John K.

1947-01-01

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.

Receptores de estrógeno e progesterona em células do sedimento de fluido peritoneal na endometriose pélvica: estudo imunocitoquímico

Directory of Open Access Journals (Sweden)

Eleutério Junior José

2001-01-01

Full Text Available Objetivo: avaliar a expressão de receptores de estrógeno (RE e progesterona (RP em esfregaços de sedimento de fluido peritoneal em pacientes com endometriose, comparando-a com a de mulheres sem endometriose. Métodos: foi realizado imunocitoquímica para RE e RP em esfregaços de sedimento de fluido peritoneal em 19 casos de endometriose e 7 sem endometriose (controle. Os dados foram submetidos ao teste t de Student para análise estatística. Resultados: em 84,6% dos casos de pacientes com endometriose, células tipo endometrial expressaram RE, numa média de 4,1%, ao passo que nos casos sem endometriose foi positivo em 42,9%, com uma expressão média de 4,5% (p = 0,1706. RP foi expresso apenas em um caso, com endometriose, com história de rotura de endometrioma. Conclusões: não houve diferença da expressão de RE entre os casos de endometriose e os casos-controle, observando-se um comportamento distinto em tecidos. Um mais aprofundado estudo deve ser feito para melhor avaliar o enigmático mecanismo envolvido na manifestação de receptores hormonais em células esfoliadas.

Influence of tip clearance on flow behavior and noise generation of centrifugal compressors in near-surge conditions

International Nuclear Information System (INIS)

Galindo, J.; Tiseira, A.; Navarro, R.; López, M.A.

2015-01-01

Highlights: • Centrifugal compressor aeroacoustics sensitivity to tip clearance is investigated. • 3 different clearance ratios are set in accordance to expected operating values. • Pressure spectra do not depend on tip clearance ratio in near-surge conditions. • DES performs better than URANS in predicting compressor acoustic signature. • Flow field observation reveals that tip clearance is immersed in rotating backflow. - Abstract: CFD has become an essential tool for researchers to analyze centrifugal compressors. Tip leakage flow is usually considered one of the main mechanisms that dictate compressor flow field and stability. However, it is a common practice to rely on CAD tip clearance, even though the gap between blades and shroud changes when compressor is running. In this paper, sensitivity of centrifugal compressor flow field and noise prediction to tip clearance ratio is investigated. 3D CFD simulations are performed with three different tip clearance ratios in accordance to expected operating values, extracted from shaft motion measurements and FEM predictions of temperature and rotational deformation. Near-surge operating conditions are simulated with URANS and DES. DES shows superior performance for acoustic predictions. Cases with reduced tip clearance present higher pressure ratio and isentropic efficiency, but no significant changes in compressor acoustic signature are found when varying clearance. In this working point, tip clearance is immersed in a region of strongly swirling backflow. Therefore, tip leakage cannot establish any coherent noise source mechanism

Program for aerodynamic performance tests of helium gas compressor model of the gas turbine high temperature reactor (GTHTR300)

International Nuclear Information System (INIS)

Takada, Shoji; Takizuka, Takakazu; Kunimoto, Kazuhiko; Yan, Xing; Itaka, Hidehiko; Mori, Eiji

2003-01-01

Research and development program for helium gas compressor aerodynamics was planned for the power conversion system of the Gas Turbine High Temperature Reactor (GTHTR300). The axial compressor with polytropic efficiency of 90% and surge margin more than 30% was designed with 3-dimensional aerodynamic design. Performance and surge margin of the helium gas compressor tends to be lower due to the higher boss ratio which makes the tip clearance wide relative to the blade height, as well as due to a larger number of stages. The compressor was designed on the basis of methods and data for the aerodynamic design of industrial open-cycle gas-turbine. To validate the design of the helium gas compressor of the GTHTR300, aerodynamic performance tests were planned, and a 1/3-scale, 4-stage compressor model was designed. In the tests, the performance data of the helium gas compressor model will be acquired by using helium gas as a working fluid. The maximum design pressure at the model inlet is 0.88 MPa, which allows the Reynolds number to be sufficiently high. The present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

40 CFR 60.482-3a - Standards: Compressors.

Science.gov (United States)

2010-07-01

...) Operated with the barrier fluid at a pressure that is greater than the compressor stuffing box pressure; or... § 60.482-10a; or (3) Equipped with a system that purges the barrier fluid into a process stream with...

A study on two phase flows of linear compressors for the prediction of refrigerant leakage

International Nuclear Information System (INIS)

Hwang, Il Sun; Lee, Young Lim; Oh, Won Sik; Park, Kyeong Bae

2015-01-01

Usage of linear compressors is on the rise due to their high efficiency. In this paper, leakage of a linear compressor has been studied through numerical analysis and experiments. First, nitrogen leakage for a stagnant piston with fixed cylinder pressure as well as for a moving piston with fixed cylinder pressure was analyzed to verify the validity of the two-phase flow analysis model. Next, refrigerant leakage of a linear compressor in operation was finally predicted through 3-dimensional unsteady, two phase flow CFD (Computational fluid dynamics). According to the research results, the numerical analyses for the fixed cylinder pressure models were in good agreement with the experimental results. The refrigerant leakage of the linear compressor in operation mainly occurred through the oil exit and the leakage became negligible after about 0.4s following operation where the leakage became lower than 2.0x10 -4 kg/s.

Extensive optimisation analyses of the piping of two large underground gas storage ariel compressors

NARCIS (Netherlands)

Eijk, A.; Korst, H.J.C.; Ploumen, G.; Heyer, D.

2007-01-01

Two large identical 6-cylinder Ariel JGB/6 compressors of each 7.5 Mw, are used for the underground gas storage (UGS) plant of Essent in Epe, Germany. The compressors can be operated at a wide range of operating conditions, e.g. variable suction and discharge pressures, 2-stage mode during gas

Stability Improvement of High-Pressure-Ratio Turbocharger Centrifugal Compressor by Asymmetric Flow Control-Part I: Non-Axisymmetrical Flow in Centrifugal Compressor.

Science.gov (United States)

Yang, Mingyang; Zheng, Xinqian; Zhang, Yangjun; Bamba, Takahiro; Tamaki, Hideaki; Huenteler, Joern; Li, Zhigang

2013-03-01

This is Part I of a two-part paper documenting the development of a novel asymmetric flow control method to improve the stability of a high-pressure-ratio turbocharger centrifugal compressor. Part I focuses on the nonaxisymmetrical flow in a centrifugal compressor induced by the nonaxisymmetrical geometry of the volute while Part II describes the development of an asymmetric flow control method to avoid the stall on the basis of the characteristic of nonaxisymmetrical flow. To understand the asymmetries, experimental measurements and corresponding numerical simulation were carried out. The static pressure was measured by probes at different circumferential and stream-wise positions to gain insights about the asymmetries. The experimental results show that there is an evident nonaxisymmetrical flow pattern throughout the compressor due to the asymmetric geometry of the overhung volute. The static pressure field in the diffuser is distorted at approximately 90 deg in the rotational direction of the volute tongue throughout the diffuser. The magnitude of this distortion slightly varies with the rotational speed. The magnitude of the static pressure distortion in the impeller is a function of the rotational speed. There is a significant phase shift between the static pressure distributions at the leading edge of the splitter blades and the impeller outlet. The numerical steady state simulation neglects the aforementioned unsteady effects found in the experiments and cannot predict the phase shift, however, a detailed asymmetric flow field structure is obviously obtained.

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

Positive feedback stabilization of centrifugal compressor surge

NARCIS (Netherlands)

Willems, F.P.T.; Heemels, W.P.M.H.; Jager, de A.G.; Stoorvogel, A.A.

2002-01-01

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

Numerical study on oil supply system of a rotary compressor

International Nuclear Information System (INIS)

Wu, Jianhua; Wang, Gang

2013-01-01

The oil supply system is a crucial reliability issue for rotary compressors. This paper provides a general method for analyzing the oil supply system of a rotary compressor by using computational fluid dynamics (CFD). The process includes establishing the physical model, dividing computational grid, setting boundary conditions, calculating leakage rates through the roller end clearances, translating the dynamic issue into the static issue and so on. Validation of the rationality of the oil supply system model has been made by the measurement of the main bearing oil flow rates. The effects of operating conditions of the compressor, the oil level height of the oil sump and the main design parameters of the oil supply system on the oil supply characteristics are analyzed by numerical simulation. It is found that the main bearing oil flow rate varies circularly along with the rotation of the shaft. The shape and inclination angle of the spiral groove also influence the main bearing oil flow rate. The oil leakage rates through the roller end clearances depend largely on the operating conditions. In addition, the oil level height of the oil sump has a huge effect on the total oil flow rate. -- Highlights: • A CFD method for analyzing the oil supply system of rotary compressor is presented. • Leakage through the roller end clearances depends on the operating condition. • Groove shape and inclination angle are the main design parameters of spiral grooves. • A parabolic interface of oil and gas can be formed in the gallery of the shaft. • Single-flow model and steady solver can be applied to the oil supply system

Coatings for Fuel Cell Propulsion Compressor Bearings, Phase I

Data.gov (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....

Vapor Compressor Driven Hybrid Two-Phase Loop, Phase I

Data.gov (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...

Feasibility of Applying Active Lubrication to Reduce Vibration in Industrial Compressors

DEFF Research Database (Denmark)

Santos, Ilmar; Nicoletti, Rodrigo; Scalabrin, A.

2004-01-01

of the orifices distributed over the sliding surface. The dynamic coefficients of tilting-pad bearings with and without active lubrication and their influence on an industrial compressor of 391 Kg, which operates with a maximum speed of 10,200 rpm, are analyzed. In the original compressor design, the bearing...... housings are mounted on squeeze-film dampers in order to ensure reasonable stability margins during full load condition (high maximum continuous speed). Instead of having a combination of tilting-pad bearings and squeeze-film dampers, another design solution is proposed and theoretically investigated...

Compressor Modeling for Transient Analysis of Supercritical CO2 Brayton Cycle by using MARS code

Energy Technology Data Exchange (ETDEWEB)

Park, Joo Hyun; Park, Hyun Sun; Kim, Tae Ho; Kwon, Jin Gyu [POSTECH, Pohang (Korea, Republic of); Bae, Sung Won; Cha, Jae Eun [KAERI, Daejeon (Korea, Republic of)

2016-05-15

In this study, SCIEL (Supercritical CO{sub 2} Integral Experimental Loop) was chosen as a reference loop and the MARS code was as the transient cycle analysis code. As a result, the compressor homologous curve was developed from the SCIEL experimental data and MARS analysis was performed and presented in the paper. The advantages attract SCO{sub 2}BC as a promising next generation power cycles. The high thermal efficiency comes from the operation of compressor near the critical point where the properties of SCO{sub 2}. The approaches to those of liquid phase, leading drastically lower the compression work loss. However, the advantage requires precise and smooth operation of the cycle near the critical point. However, it is one of the key technical challenges. The experimental data was steady state at compressor rotating speed of 25,000 rpm. The time, 3133 second, was starting point of steady state. Numerical solutions were well matched with the experimental data. The mass flow rate from the MARS analysis of approximately 0.7 kg/s was close to the experimental result of 0.9 kg/s. It is expected that the difference come from the measurement error in the experiment. In this study, the compressor model was developed and implemented in MARS to study the transient analysis of SCO{sub 2}BC in SCIEL. We obtained the homologous curves for the SCIEL compressor using experimental data and performed nodalization of the compressor model using MARS code. In conclusions, it was found that numerical solutions from the MARS model were well matched with experimental data.

Centrifugal compressor shape modification using a proposed inverse design method

International Nuclear Information System (INIS)

Niliahmadabadi, Mahdi; Poursadegh, Farzad

2013-01-01

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%.

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)

2013-03-15

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%.

Ultralow temperature helium compressor for Japan Atomic Energy Research Institute

International Nuclear Information System (INIS)

Asakura, Hiroshi

1988-01-01

Ishikawajima Harima Heavy Industries Co., Ltd. started the development of an ultralow temperature helium compressor for helium liquefaction in 1984 jointly with Japan Atomic Energy Research Institute, and has delivered the first practical machine to the Superconductive Magnet Laboratory of JAERI. For a large superconductive magnet to be used in the stable state for a fusion reactor, conventional superconductive materials (NbTi, NbTi 3 Sn, etc.) must be used, being cooled forcibly with supercritical helium. The supercritical helium which is compressed above the critical pressure of 228 kPa has a stable cooling effect since the thermal conductivity does not change due to the evaporation of liquid helium. In order to maintain the temperature of the supercritical helium below 4 K before it enters a magnet, a heat exchanger is used. The compressor that IHI has developed has the ability to reduce the vapor pressure of liquid helium from atmospheric pressure to 50.7 kPa, and can attain the temperature of 3.5 K. The specification of this single stage centrifugal compressor is: mass flow rate 25 - 64 g/s, speed 80,000 rpm, adiabatic efficiency 62 - 69 %. The structure and the performance are reported. (K.I.)

Variable speed hermetic reciprocating compressors for domestic refrigerators

DEFF Research Database (Denmark)

Rasmussen, Bjarne D.

1998-01-01

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...

Rotor-generated unsteady aerodynamic interactions in a 1½ stage compressor

Science.gov (United States)

Papalia, John J.

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

Study of blade aspect ratio on a compressor front stage aerodynamic and mechanical design report

Science.gov (United States)

Burger, G. D.; Lee, D.; Snow, D. W.

1979-01-01

A single stage compressor was designed with the intent of demonstrating that, for a tip speed and hub-tip ratio typical of an advanced core compressor front stage, the use of low aspect ratio can permit high levels of blade loading to be achieved at an acceptable level of efficiency. The design pressure ratio is 1.8 at an adiabatic efficiency of 88.5 percent. Both rotor and stator have multiple-circular-arc airfoil sections. Variable IGV and stator vanes permit low speed matching adjustments. The design incorporates an inlet duct representative of an engine transition duct between fan and high pressure compressor.

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)

2016-10-15

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.

Structure design and simulation research of active magnetic bearing for helium centrifugal cold compressor

Science.gov (United States)

Y Zhang, S.; Pan, W.; Wei, C. B.; Wu, J. H.

2017-12-01

Helium centrifugal cold compressors are utilized to pump gaseous helium from saturated liquid helium tank to obtain super-fluid helium in cryogenic refrigeration system, which is now being developed at TIPC, CAS. Active magnetic bearing (AMB) is replacing traditional oil-fed bearing as the optimal supporting assembly for cold compressor because of its many advantages: free of contact, high rotation speed, no lubrication and so on. In this paper, five degrees of freedom for AMB are developed for the helium centrifugal cold compressor application. The structure parameters of the axial and radial magnetic bearings as well as hardware and software of the electronic control system is discussed in detail. Based on modal analysis and critical speeds calculation, a control strategy combining PID arithmetic with other phase compensators is proposed. Simulation results demonstrate that the control method not only stables AMB system but also guarantees good performance of closed-loop behaviour. The prior research work offers important base and experience for test and application of AMB experimental platform for system centrifugal cold compressor.

Hydrogen sulfide booster compressors for HWP Manuguru - oil reclamation study - BHEL experience (Paper No. 5.2)

International Nuclear Information System (INIS)

Godbole, A.; Santanam, N.; Murthy, T.S.R.

1992-01-01

BHEL undertook the development of hydrogen sulphide booster compressor with a view to indigenise this most critical equipment in a heavy water plant. Throughout the design, manufacture and shop testing of these booster compressors BHEL had close interaction with Heavy Water Board. This paper describes the problems faced during commissioning of compressors at KCR -Manuguru such as deficiencies in the sizing of LP seal oil drain, development of a process for reclamation of oil and development of alternate sealing arrangement, etc. (author). 1 tab., 4 figs

Study on pressure pulsation and piping vibration of complex piping of reciprocating compressor

International Nuclear Information System (INIS)

Xu Bin; Feng Quanke; Yu Xiaoling

2008-01-01

This paper presents a preliminary research on the piping vibration and pressure pulsation of reciprocating compressor piping system. On the basis of plane wave theory, the calculation of gas column natural frequency and pressure pulsation in complex pipelines is done by using the transfer matrix method and stiffness matrix method, respectively. With the discretization method of FEM, a mathematical model for calculating the piping vibration and stress of reciprocating compressor piping system is established, and proper boundary conditions are proposed. Then the structural modal and stress of the piping system are calculated with CAESAR II. The comparison of measured and calculated values found that the one dimensional wave equation can accurately calculate the natural frequency and pressure pulsation in gas column of piping system for reciprocating compressor. (authors)

Simulated dynamic response of a multi-stage compressor with variable molecular weight flow medium

Science.gov (United States)

Babcock, Dale A.

1995-01-01

A mathematical model of a multi-stage compressor with variable molecular weight flow medium is derived. The modeled system consists of a five stage, six cylinder, double acting, piston type compressor. Each stage is followed by a water cooled heat exchanger which serves to transfer the heat of compression from the gas. A high molecular weight gas (CFC-12) mixed with air in varying proportions is introduced to the suction of the compressor. Condensation of the heavy gas may occur in the upper stage heat exchangers. The state equations for the system are integrated using the Advanced Continuous Simulation Language (ACSL) for determining the system's dynamic and steady state characteristics under varying operating conditions.

Design of a high-performance centrifugal compressor with new surge margin improvement technique for high speed turbomachinery

Directory of Open Access Journals (Sweden)

Sagar Pakle

2018-03-01

Full Text Available This paper presents the design of a centrifugal compressor for high-speed turbomachinery. The main focus of the research is to develop a centrifugal compressor with improved aerodynamic performance. As a meridional frame has a significant effect on overall performance of the compressor, special attention has been paid to the end wall contours. The shroud profile is design with bezier curve and hub profile with circular arc contour. The blade angle distribution has been arranged in a manner that it merges with single value at impeller exit. The rake angle is positive at leading edge and negative at trailing edge with identical magnitude. Furthermore, three-dimensional straight line element approach has been used for this design for better manufacturability. The verification of the aerodynamic performance has been carried out using CFD software with consideration of a single blade passage and vaneless diffuser. The result has been compared with matching size aftermarket compressor stage gas stand data. The compressor stage with Trim 55 provides 34% increase in choke flow at 210000 RPM as compared to gas stand data with 87% peak stage efficiency at 110000 RPM. In addition, new surge margin improvement technique has been proposed by means of diffuser enhancement. This technique provides an average of 16% improvement in surge margin compared to standard diffuser stage with 55 trim compressor impeller. The mechanical integrity has been validated at maximum RPM with the aluminum alloy 2014-T6 as a fabrication material. Keywords: Centrifugal compressor, Aerodynamic performance, Surge margin, Blade angles, Stress analysis, Computational fluid dynamics

Probabilistic analysis of manufacturing uncertainties for an automotive turbocharger centrifugal compressor using numerical and experimental methods

NARCIS (Netherlands)

Javed, A.; Kamphues, E.; Hartuc, T.; Pecnik, R.; Van Buijtenen, J.P.

2015-01-01

The compressor impellers for mass-produced turbochargers are generally die-casted and machined to their final configuration. Manufacturing uncertainties are inherently introduced as stochastic dimensional deviations in the impeller geometry. These deviations eventually propagate into the compressor

A numerical and experimental investigation of the thermal control performance of a spaceborne compressor assembly

Science.gov (United States)

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

2011-09-01

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.

Loss reduction in axial-flow compressors through low-speed model testing

Science.gov (United States)

Wisler, D. C.

1984-01-01

A systematic procedure for reducing losses in axial-flow compressors is presented. In this procedure, a large, low-speed, aerodynamic model of a high-speed core compressor is designed and fabricated based on aerodynamic similarity principles. This model is then tested at low speed where high-loss regions associated with three-dimensional endwall boundary layers flow separation, leakage, and secondary flows can be located, detailed measurements made, and loss mechanisms determined with much greater accuracy and much lower cost and risk than is possible in small, high-speed compressors. Design modifications are made by using custom-tailored airfoils and vector diagrams, airfoil endbends, and modified wall geometries in the high-loss regions. The design improvements resulting in reduced loss or increased stall margin are then scaled to high speed. This paper describes the procedure and presents experimental results to show that in some cases endwall loss has been reduced by as much as 10 percent, flow separation has been reduced or eliminated, and stall margin has been substantially improved by using these techniques.

A numerical strategy for modelling rotating stall in core compressors

Science.gov (United States)

Vahdati, M.

2007-03-01

The paper will focus on one specific core-compressor instability, rotating stall, because of the pressing industrial need to improve current design methods. The determination of the blade response during rotating stall is a difficult problem for which there is no reliable procedure. During rotating stall, the blades encounter the stall cells and the excitation depends on the number, size, exact shape and rotational speed of these cells. The long-term aim is to minimize the forced response due to rotating stall excitation by avoiding potential matches between the vibration modes and the rotating stall pattern characteristics. Accurate numerical simulations of core-compressor rotating stall phenomena require the modelling of a large number of bladerows using grids containing several tens of millions of points. The time-accurate unsteady-flow computations may need to be run for several engine revolutions for rotating stall to get initiated and many more before it is fully developed. The difficulty in rotating stall initiation arises from a lack of representation of the triggering disturbances which are inherently present in aeroengines. Since the numerical model represents a symmetric assembly, the only random mechanism for rotating stall initiation is provided by numerical round-off errors. In this work, rotating stall is initiated by introducing a small amount of geometric mistuning to the rotor blades. Another major obstacle in modelling flows near stall is the specification of appropriate upstream and downstream boundary conditions. Obtaining reliable boundary conditions for such flows can be very difficult. In the present study, the low-pressure compression (LPC) domain is placed upstream of the core compressor. With such an approach, only far field atmospheric boundary conditions are specified which are obtained from aircraft speed and altitude. A chocked variable-area nozzle, placed after the last compressor bladerow in the model, is used to impose boundary

Engineering task plan for BX/BY compressor upgrade

International Nuclear Information System (INIS)

Strand, R.G.

1995-01-01

This Engineering Task Plan outlines the remaining work to be completed for the BX/BY Instrument Air upgrade. Initial work efforts were guided by Engineering Work Plan, ''BX-BY Compressor Upgrade'' dated 1-25-93 (see Attachment A) which is provided for information. The overall engineering task is to provide a permanent replacement for the instrument air supply system for the 241-BX/BY Tank Farms. The existing system consists of a 25 horsepower Worthington non-lube compressor and an Oriad air dryer. The existing equipment is dated, requires high maintenance and is located in a contaminated zone making it unusable. The BX/BY instrument air replacement unit will be one of the 100 SCFM generic air stations. This station will be permanently sited with the addition of drawing changes to provide a concrete foundation, air piping to existing lines and electrical power supply tie-ins

Fully coupled fluid-structure interaction model of reed valves in a multi-cylinder reciprocating piston compressor

Science.gov (United States)

Xie, F.; Nieter, J.; Lifson, A.; Reba, R.; Sishtla, V.

2017-08-01

For years compressor researchers have tried to account for the fluid interaction effect of the working fluid on valve motion in displacement compressors. In recent years, the computing capacities and available CFD and FEA programs have allowed fully coupled interaction of fluids and moving structures to be modelled more comprehensively. This paper describes our experience and results from developing a model of a multi-cylinder reciprocating piston compressor with suction and discharge valve systems that are fully coupled with the pressure pulsation in the adjacent plenum. Valve dynamics are captured by the model that affects compressor performance. The results show that higher running speed causes more discharge valve delay on closing due to higher pressure pulsation in discharge plenum. The acoustic property of the discharge plenum as it relates to valve motion is studied by the developed cost-effective standalone model.

Stall inception and warning in a single-stage transonic axial compressor with axial skewed slot casing treatment

International Nuclear Information System (INIS)

Lim, Byeung Jun; Kwon, Se Jin; Park, Tae Choon

2014-01-01

Characteristic changes in the stall inception in a single-stage transonic axial compressor with an axial skewed slot casing treatment were investigated experimentally. A rotating stall occurred intermittently in a compressor with an axial skewed slot, whereas spike-type rotating stalls occurred in the case of smooth casing. The axial skewed slot suppressed stall cell growth and increased the operating range. A mild surge, the frequency of which is the Helmholtz frequency of the compressor system, occurred with the rotating stall. The irregularity in the pressure signals at the slot bottom increased decreasing flow rate. An autocorrelation-based stall warning method was applied to the measured pressure signals. Results estimate and warn against the stall margin in a compressor with an axial skewed slot.

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2017-08-01

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

Design and development of a four-cell sorption compressor based J-T cooler using R134a as working fluid

Energy Technology Data Exchange (ETDEWEB)

Mehta, R. N. [Mechanical Engineering Department, Indian Institute of Technology Bombay, Mumbai - 400076, India and Government Engineering College Bharuch, Gujarat - 392002 (India); Bapat, S. L.; Atrey, M. D. [Mechanical Engineering Department, Indian Institute of Technology Bombay, Mumbai - 400076 (India)

2014-01-29

The need of a cooler with no electromagnetic interference and practically zero vibration has led to sorption compressor based Joule-Thomson (J-T) coolers. These are useful for sophisticated electronic, ground based and space borne systems. In a Sorption compressor, adsorbed gases are desorbed into a confined volume by raising temperature of the sorption bed resulting in an increase in pressure of the liberated gas. In order to have the system (compressor) functioning on a continuous basis, with almost a constant gas flow rate, multiple cells are used with the adaptation of Temperature Swing Adsorption (TSA) process. As the mass of the desorbed gas dictates the compressor throughput, a combination of sorbent material with high adsorption capacity for a chosen gas or gas mixture has to be selected for efficient operation of the compressor. Commercially available (coconut-shell base) activated carbon has been selected for the present application. The characterization study for variation of discharge pressure is used to design the Four-cell sorption compressor based cryocooler with a desired output. Apart from compressor, the system includes a) After cooler b) Return gas heat exchanger c) capillary tube as the J-T expansion device and d) Evaporator.

Low emissions system featured on compressor drive

International Nuclear Information System (INIS)

Curtis, T.

1995-01-01

A high speed power turbine is offered as an option with direct drive capability for pipeline compressors and other high-speed applications. As developed, it features ease of maintenance with rotor and nozzle assembly in a single cartridge to allow quick change-out or replacement of parts on site. The new compressor drive builds extensively on proven technology and is expected to provide lower installed and life-cycle costs per unit horsepower than previous units. During its development stages, M ampersand IE preformed cost and risk assessment of several design configurations and concluded that a derivative approach based on the standard unit was an optimal solution in the 39,000 shp range. A two-shaft gas turbine is expected to be applied in the industrial and commercial marine markets, including 50- and 60-Hertz power generation applications, pipeline compression, gas injection, and fast ferry commercial marine uses. Emissions controls for the system will include water or steam injection using a standard combustor or M and IE's DLE combustion system

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

Directory of Open Access Journals (Sweden)

Hyun-Jin Ahn

2016-03-01

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.

Numerical simulation of air flow through turbocharger compressors with dual volute design

Energy Technology Data Exchange (ETDEWEB)

Jiao, Kui; Li, Xianguo; Wu, Hao [Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON (Canada); Sun, Harold; Schram, Tim [Ford Motor Company, Dearborn, MI 48126 (United States); Krivitzky, Eric; Larosiliere, Louis M. [Concepts NREC, White River Junction, VT 05001 (United States)

2009-11-15

In this paper, turbocharger centrifugal compressors with dual volute design were investigated by using Computational Fluid Dynamics (CFD) method. The numerical simulation focused on the air flow from compressor impeller inlet to volute exit, and the overall performance level and range are predicted. The numerical investigation revealed that the dual volute design could separate the compressor into two operating regions: ''high efficiency'' and ''low efficiency'' regions with different air flow characteristics, and treating these two regions separately with dual diffuser design showed extended stable operating range and improved efficiency by comparing with conventional single volute design. The ''dual sequential volute'' concept also showed the potential to further extend the stable operating range by closing one of the volutes at low air flow rates. Furthermore, by comparing with other alternate designs such as variable diffuser vanes and variable inlet guide vanes, the operation of the dual sequential volute also features relatively simple control and calibration. (author)

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

2013-08-01

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.

Computational Analysis of Flow Through a Transonic Compressor Rotor

National Research Council Canada - National Science Library

Bochette, Nikolaus J

2005-01-01

.... In examining this problem two Computational Fluid Dynamic (CFD) codes have been used by the Naval Postgraduate School to predict the performance of a transonic compressor rotor that is being tested with steam ingestion...

Axial forces in centrifugal compressor couplings

Science.gov (United States)

Ivanov, A. N.; Ivanov, N. M.; Yun, V. K.

2017-08-01

The article presents the results of the theoretical and experimental investigation of axial forces arising in the toothed and plate couplings of centrifugal compressor shaft lines. Additional loads on the thrust bearing are considered that can develop in the toothed couplings as a result of coupled rotors misalignment. Design relationships to evaluate the level of axial forces and recommendations for their reduction in the operating conditions are given.

On the design of lubricant free piston compressors

NARCIS (Netherlands)

Owczarek, P.

2010-01-01

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

Surge control of the electrically driven centrifugal compressor

NARCIS (Netherlands)

Boinov, K.O.; Lomonova, E.A.; Vandenput, A.J.A.; Tyagounov, A.

2006-01-01

This paper presents a method of the energy efficiency and the operational performance improvement of the electrically driven air compression system. The key innovation of the proposed method-the active surge suppression of the centrifugal compressor by means of the speed control of the electrical

Basic Study on Engine with Scroll Compressor and Expander

Science.gov (United States)

Morishita, Etsuo; Kitora, Yoshihisa; Nishida, Mitsuhiro

Scroll compressors are becoming popular in air conditioning and refrigeration. This is primarily due to their higher efficiency and low noise/vibration characteristics. The scroll principle can be applied also to the steam expander and the Brayton cycle engine,as shown in the past literature. The Otto cycle spark-ignition engine with a scroll compressor and expander is studied in this report. The principle and basic structure of the scroll engine are explained,and the engine characteristic are calculated based on the idealized cycles and processes. A prototype model has been proposed and constructed. The rotary type engine has always had a problem with sealing. The scroll engine might overcome this shortcoming with its much lower rubbing speed compared to its previous counterparts,and is therefore worth investigating.

Nitric oxide-to-nitrogen dioxide conversion rates at a natural gas compressor station

International Nuclear Information System (INIS)

Gibbons, T.H.; Gebhart, D.H.

1992-01-01

An ambient air quality measurements program collected NO x data for a year at a natural gas compressor station located in the southwestern United States. This monitoring program had the unique characteristic of measuring ambient NO x concentrations at a remote location that was virtually free of NO sources other than the compressor station. These measurements indicate that the only source of NO x emissions in the area comes from the combustion of natural gas by the compressor station turbines. Thus, increases in NO 2 calculation of NO-to-NO 2 conversion rates. These results indicate 22 percent of the compressor station NO x emissions were converted to NO 2 in the near field. Regulatory modeling methods often assume that all NO x emissions exist as NO 2 . In an environment where ozone concentrations are relatively low, however, NO 2 concentrations are commonly calculated using the ozone limiting method (OLM), wherein NO conversion to NO 2 is limited by the amount of ozone present. Results from the measurement program show that the OLM generally overpredicts NO 2 concentrations in the near field. A partial conversion method is more suitable for predicting NO 2 concentrations for low-level natural gas combustion sources

Compounding Of Ac Compressor Using Waste Heat Recovery From Exhaust Gas

Directory of Open Access Journals (Sweden)

Bheshma Yogendra Kiran

2015-08-01

Full Text Available This project works on the theme of turbocharger in which a low pressure high speed turbine is placed in the exhaust gas manifold. The exhaust gas from the engine is made to rotate the turbine where the thermal power of exhaust gas is converted into rotary motion through turbine. This rotary motion from turbine is given to the turbocharger compressor which compresses the refrigerant vapor. So through this air conditioning effect is obtained without loss of any crankshaft. The kinetic energy extracted from the turbine is used to run the AC compressor by planetary gear train.

Pesquisa de anticorpos anti Toxoplasma gondii em fluidos intra-oculares (humor vítreo e humor aquoso) de pacientes com toxoplasmose ocular, na cidade de Belém, PA

OpenAIRE

Carmo,Ediclei Lima do; Almeida,Edmundo Frota; Bichara,Cléa Nazaré; Póvoa,Marinete Marins

2005-01-01

Foi realizada pesquisa de anticorpos IgG, IgM e IgA anti-Toxoplasma gondii no soro e fluidos intra-oculares (humor aquoso e vítreo) de pacientes com toxoplasmose ocular. A partir dos resultados obtidos verificou-se que anticorpos IgG e IgA intraocular anti-Toxoplasma gondii podem vir a ser importantes marcadores no diagnóstico de toxoplasmose ocular.

Investigation on steady and unsteady performance of a SCO2 centrifugal compressor with splitters

Directory of Open Access Journals (Sweden)

Guo Ding

2017-01-01

Full Text Available Supercritical carbon dioxide (SCO2 is widely concerned with its excellent physical properties. Its high density helps to achieve a compact mechanical structure, especially in all kinds of turbomachinery. In this paper, a SCO2 centrifugal compressor with splitter blades is displayed and numerically investigated. A thorough numerical analysis of the steady and unsteady performance of this SCO2 centrifugal compressor is performed in ANSYS-CFX with SST turbulence model. Streamlines, pressure and temperature under steady- and unsteady-state are compared and analyzed. Moreover, the trans-critical phenomenon at the leading edge of the rotor blade and the aerodynamic performance are covered. The results in this paper provide the foundation for the design and numerical investigation of SCO2 centrifugal compressors.

Variable gas spring for matching power output from FPSE to load of refrigerant compressor

Science.gov (United States)

Chen, Gong; Beale, William T.

1990-01-01

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.

Chicane and wiggler based bunch compressors for future linear colliders

International Nuclear Information System (INIS)

Raubenheimer, T.O.; Emma, P.; Kheifets, S.

1993-05-01

In this paper, we discuss bunch compressors for future linear colliders. In the past, the bunch compression optics has been based upon achromatic cells using strong sextupoles to correct the dispersive and betatron chromaticity. To preserve the very small emittances required in most future collider designs, these schemes tend to have very tight alignment tolerances. Here, we describe bunch compressors based upon magnetic chicanes or wigglers which do need sextupoles to correct the chromatic emittance dilution. The dispersive chromaticity cancels naturally and the betatron chromaticity is not a significant source of emittance dilution. Thus, these schemes allow for substantially reduced alignment tolerances. Finally, we present a detailed design for the NLC linear collider

The 1/3-scale aerodynamics performance test of helium compressor for GTHTR300 turbo machine of JAERI (step 1)

International Nuclear Information System (INIS)

Takada, Shoji; Takizuka, Takakazu; Kunitomi, Kazuhiko; Xing, Yan

2003-01-01

A program for research and development on aerodynamics in a helium gas compressor was planned for the power conversion system of the Gas Turbine High Temperature Reactor (GTHTR300). The three-dimensional aerodynamic design of the compressor achieved a high polytropic efficiency of 90%, keeping a sufficient surge margin over 30%. To validate the design of the helium gas compressor of GTHTR300, aerodynamic performance tests were planned, and a 1/3-scale, 4-stage compressor model was designed. In the tests, the performance data of the helium gas compressor model will be acquired by using helium gas as a working fluid. The maximum design pressure at the model inlet is 0.88 MPa, which allows the Reynolds number to be sufficiently high. The present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

The influence of wedge diffuser blade number and divergence angle on the performance of a high pressure ratio centrifugal compressor

Science.gov (United States)

Wang, Yi; Han, Ge; Lu, Xingen; Zhu, Junqiang

2018-02-01

Wedge diffuser is widely used in centrifugal compressors due to its high performance and compact size. This paper is aimed to research the influence of wedge diffuser blade number and divergence angle on centrifugal compressor performance. The impact of wedge diffuser blade number on compressor stage performance is investigated, and then the wedge diffusers with different divergence angle are studied by varying diffuser wedge angle and blade number simultaneously. It is found that wedge diffuser with 27 blades could have about 0.8% higher adiabatic efficiency and 0.14 higher total pressure ratio than the wedge diffuser with 19 blades and the best compressor performance is achieved when diffuser divergence angle is 8.3°.These results could give some advices on centrifugal compressor design.

Effects of bending-torsional duct-induced swirl distortion on aerodynamic performance of a centrifugal compressor

Science.gov (United States)

Hou, Hongjuan; Wang, Leilei; Wang, Rui; Yang, Yanzhao

2017-04-01

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.

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

2017-10-01

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.

Initial isotopic geochemistry ({delta} 18 O, {delta} D) of fluids from wells of the Los Humeros, Pue., geothermal field; Geoquimica isotopica ({delta} 18 O, {delta} D) inicial de fluidos de pozos del campo geotermico de Los Humeros, Pue.

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Ramirez Montes, Miguel; Tovar Aguado, Rigoberto [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

2010-01-15

Isotopic data ({delta} 18 O, {delta} D) from fluids from production wells at the Los Humeros, Pue., geothermal field were analyzed to investigate the possible origin of these fluids and the dominant processes of the reservoir at its initial state. According to pre-exploitation data, it is suggested the Los Humeros reservoir fluids are made of a mixture of meteoric water of very light isotopic composition (paleo-fluids) and andesitic water. The relationship {delta} D vs {delta} 18 O from pre-exploitation data indicates the produced fluids are composed of a mixture of (at least) two fluids with distinct isotopic compositions. At the more enriched end of the mixing relationship are the isotopic compositions of the wells H-23 and H-18 (located in the southern area of the field), while the lighter fluids were found in well H-16 (originally) and then in well H-16 (repaired). It was found that the liquid phases of deep wells are more enriched in {delta} 18 O while the shallow wells present lower values, suggesting a convection process at the initial state. Based on this isotopic profile, it is considered that even the production depths of the wells H-1, H-12 and H-16 (repaired) are just about the same, but their respective isotopic compositions are quite different. The {delta} 18 O value for well H-16 (repaired) seems to be that of condensate steam, while the corresponding values for wells H-1 and H-12 fall within the value interval of the deep wells (H-23). This suggests wells H-1 and H-12 are collecting very deep fluids enriched in {delta} 18 O. These results could be useful in creating a conceptual model of the reservoir. [Spanish] Se analizaron datos isotopicos ({delta}18 O, {delta}D) de los fluidos de pozos productores del campo geotermico de Los Humeros, Pue., para investigar el posible origen de los fluidos asi como los procesos dominantes del yacimiento en su estado inicial. De acuerdo con datos previos a la explotacion, se plantea que los fluidos del yacimiento

An approach for establishing the performance maps of the sc-CO_2 compressor: Development and qualification by means of CFD simulations

International Nuclear Information System (INIS)

Pham, H.S.; Alpy, N.; Ferrasse, J.H.; Boutin, O.; Tothill, M.; Quenaut, J.; Gastaldi, O.; Cadiou, T.; Saez, M.

2016-01-01

Highlights: • Ability of CFD to predict the performance of a sc-CO_2 test compressor is shown. • Risk of vapor pockets occurrence inside a scale 1:1 compressor is highlighted. • Limitation of previous performance maps approaches to model the real gas behavior is shown. • A performance maps approach for the sc-CO_2 compressor is proposed and validated. - Abstract: One of the challenges in the performance prediction of the supercritical CO_2 (sc-CO_2) compressor is the real gas behavior of the working fluid near the critical point. This study deals with the establishment of an approach that allows coping with this particularity by dressing compressor performance maps in adequate reduced coordinates (i.e., suitable dimensionless speed and flow parameters inputs and pressure ratio and enthalpy rise outputs), while using CFD for its validation. Two centrifugal compressor designs have been considered in this work. The first one corresponds to a 6 kW small scale component implemented in a test loop at Tokyo Institute of Technology. The second one corresponds to a 38 MW scale 1:1 design considered at an early stage of a project that investigates sc-CO_2 cycle for a Small Modular Reactor application. Numerical results on the former have been successfully confronted with the experimental data to qualify the ability of CFD to provide a performance database. Results on the latter have revealed a significant decrease in the static temperature and pressure during flow acceleration along the leading edge of the impeller blades. In this line, the increased risk of vapor pockets appearance inside a sc-CO_2 compressor has been highlighted and recommendations regarding the choice of the on-design inlet conditions and the compressor design have been given to overcome this concern. CFD results on the scale 1:1 compressor have then been used to evaluate the relevancy of some previous performance maps approaches for a sc-CO_2 compressor application. These include the conventional

Unsteady flow measurements in centrifugal compressors

International Nuclear Information System (INIS)

Bammert, K.; Mobarak, A.; Rautenberg, M.

1976-01-01

Centrifugal compressors and blowers are often used for recycling the coolant gas in gas-cooled reactors. To achieve the required high pressure ratios, highly loaded centrifugal compressors are built. The paper deals with unsteady flow measurements on highly loaded centrifugal impellers. Measurements of the approaching flow have been done with hot wires. The method of measurement enabled us to get the velocity distribution across the pitch ahead of the inducer. The static pressure signals along the shroud line has been discussed on the basis of some theoretical considerations. Accordingly the form of flow in the impeller and the wave flow or separation zones in the impeller can now be better interpreted. The importance of the unsteady nature of the relative flow, especially at impeller exit, is clearly demonstrated. Measurements with high responsive total pressure probes in the vicinity of impeller exit and the subsequent calculations have shown, that the instantaneous energy transfer at a certain point after the impeller may differ by more than 30% from the Euler work. Lastly, unsteady pressure measurements along the shroud line have been performed during surge and rotating stall. The surge signal have been analyzed in more detail and the mechanism of flow rupture and pressure recovery during a surge cycle is thoroughly discussed. (orig.) [de

Design, fabrication, commissioning, and testing of a 250 g/s, 2-K helium cold compressor system

International Nuclear Information System (INIS)

V. Ganni; D. M. Arenius; B. S. Bevins; W. C. Chronis; J. D. Creel; J. D. Wilson Jr.

2002-01-01

In June 1999 the Thomas Jefferson National Accelerator Facility (TJNAF) Cryogenic Systems Group had completed the design, fabrication, and commissioning of a cold compressor system capable of pumping 250 g/s of 2-K helium vapor to a pressure above 1 bar. The 2-K cold box consists of five stages of centrifugal variable speed compressors with LN2 cooled drive motors and magnetic bearings, a plate fin heat exchanger, and an LN2 shield system. The new 2-K cold box (referred to as the SCN) was built as a redundant system to an existing four stage cold compressor SCM cold box that was commissioned in May 1994. The SCN has been in continuous service supporting the facility experiments since commissioning. This system has achieved a significant improvement in the total 2-K refrigeration system capacity and stability and has substantially increased the operating envelope both in cold compressor flow and operating pressure range. This paper describes the cold box configuration and the experience s in the design, fabrication, commissioning and performance evaluation. The capacity of the system for various operating pressures (0.040 to 0.025 bar at the load corresponding to a total compressor pressure ratio of 28 to 54) is presented. An effort is made to characterize the components and their operating data over the tested range. This includes the return side pressure drop in the distribution system, the heat exchanger, and the cold compressor characteristics. The system design parameters and their effects on performance are outlined