Improvement of Rotordynamic Performance of Integrally Geared Centrifugal Compressors Through a Systematic Design Modification Approach

2019 ◽  
Author(s):  
Zhusan Luo ◽  
Carl Schwarz
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
High Reliability ◽  
Air Separation ◽  
Centrifugal Compressors ◽  
Design Modification ◽  
Design Variables ◽  
Short Period ◽  
Key Indicators ◽  
Bearing System

Abstract Integrally geared centrifugal compressors have found wide applications in air separation plants and the petrochemical industry because they can be readily designed to run at a higher efficiency than in-line compressors. Many of these compressors with multiple stages are designed to meet the demands for high power and high speed applications with high efficiency and high reliability. These requirements are challenges for their rotordynamic designs. Some compressors may experience excessive synchronous or subsynchronous vibrations during commissioning or in a short period of service. This study starts with discussing the vibration characteristics of a compressor pinion-bearing system, including undamped critical speeds, unbalance responses, and rotordynamic stability. To improve the rotordynamic performance, a systematic and feasible approach for modifying a rotordynamic design has been proposed. It has been showed that damped modes at an operating speed are key indicators of the rotordynamic performance. The sensitivities of damped modes to main design variables, i.e. bearing geometry, shaft geometry and impeller mass properties, are thoroughly examined. A procedure for design modification is proposed for general guidance. The feasibility and effectiveness of this method have been demonstrated in the modification of a pinion-bearing system. In addition, this paper also proposes a method to evaluate the torsional natural frequencies of an equivalent pinion model and briefly discusses the application of optimal design methodology to the rotordynamic design modification.

A Study on 400V Sized Trench Power Semiconductor for Smart Power ICs

2013 ◽  
Vol 712-715 ◽  
pp. 1771-1774
Author(s):  
Ey Goo Kang
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
High Reliability ◽  
Low Noise ◽  
Noise Power ◽  
Smart Power ◽  
Large Power ◽  
Power Mosfet ◽  
Power Semiconductor ◽  
Fast Switching

Power MOSFET is develop in power savings, high efficiency, small size, high reliability, fast switching, low noise. Power MOSFET can be used high-speed switching transistors devices. Recently attention to the motor and the application of various technologies. Power MOSFET is devices the voltage-driven approach switching devices are design to handle on large power, power supplies, converters, motor controllers. In this paper, design the 400 V Planar type, and design the trench type for realization of low on-resistance. Trench Power MOSFET Vth : 3.25 V BV : 484 V Ron : 0.0395 Ohm has been optimized.

High-Performance and High-CRI OLEDs for Lighting and Their Fabrication Processes

2010 ◽  
Vol 75 ◽  
pp. 65-73 ◽  
Author(s):  
Takuya Komoda ◽  
Toshihiro Iwakuma ◽  
Minoru Yamamoto ◽  
Nobuto Oka ◽  
Yuzo Shigesato
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
High Reliability ◽  
Thin Layers ◽  
Heat Radiation ◽  
High Luminance ◽  
Time Operation ◽  
Long Lifetime ◽  
White Oleds ◽  
Material Utilization

The improvement of the basic performance makes white OLEDs the promising candidate of the next generation, environmental friendly lighting source. However, for the practical application, additional properties of higher color rendering index (CRI), long lifetime at high luminance, large area uniform light emission, and high reliability for long time operation are required. Furthermore, innovative fabrication processes specialized for OLED lighting are required to reduce the cost by improving the material utilization and productivity. We developed various technologies for OLED lighting in the Japanese governmental project “High-efficiency lighting based on the organic light-emitting mechanism” from 2007. In this project, high CRI, highly efficient and long lifetime white OLEDs were realized by optically designed two-unit structure with a fluorescent deep blue emissive unit and a green / red phosphorescent unit. A reliable encapsulation structure with high heat radiation and moisture-proof characteristics realized a stable emission at high luminance as well as long storage stability. Additionally, thermal diffusivities of organic thin films with sub-hundred nanometer thicknesses were analyzed by a “rear heating/front detection type” nanosecond thermo-reflectance method. High speed wet coating process and vacuum deposition process for very thin layers were developed to improve the accuracy, material utilization and productivity.

Design of Test System for one Type of Airborne Photoelectric Equipment Based on PC104 Bus

2012 ◽  
Vol 241-244 ◽  
pp. 789-792
Author(s):  
Man Yi Hou ◽  
Hui Lin Fan ◽  
Xian Yong Jing
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
High Reliability ◽  
Test System ◽  
Power Bus ◽  
Photoelectric Equipment ◽  
Embedded Computer ◽  
Develop Software ◽  
Multithreading Technology ◽  
Signal Conditioning Circuit

A certain type of airborne photoelectric equipment is the key device for aiming and distance measuring. On the basis of analyzing the test requirement of the equipment, a test system is designed with PC104 embedded computer as the core control system. The function of the test system is suggested. Hardware programs of power, bus board, signal conditioning circuit and anti-jamming measure are designed. The multithreading technology and measures to prevent wrong data communicating are applied to develop software of the test system. The test system can be applied to test and debug the photoelectric equipment. The data handling technology used in the test equipment has advantages as high speed, high efficiency and high reliability.

Proposal of High-Quality Laser Hardening System for Shaft Parts Using Cylindrical Mirror and Ring-Beam Shaped by High-Speed Laser Scan System

2020 ◽  
Author(s):  
Hirotaka Tanabe ◽  
Keiji Ogawa ◽  
Heisaburo Nakagawa ◽  
Hirohito Tsukada ◽  
Yuki Goto
Keyword(s):  
Heat Treatment ◽  
Laser Beam ◽  
High Speed ◽  
High Efficiency ◽  
High Reliability ◽  
Low Cost ◽  
Treatment Method ◽  
Post Processing ◽  
High Quality ◽  
Almost All

Abstract Shaft parts are important parts used in almost all machines including automobiles. In addition, extremely high reliability is required since a shaft failure is directly linked to a fatal machine trouble. Therefore, a hardening process is usually conducted to improve strength and wear resistance. In this study, we propose a new laser heat treatment method to produce high-quality and high-accuracy shafts with high efficiency, low cost and low environmental impact. We will also develop a technique to derive the appropriate laser irradiation conditions quickly and systematically for shafts with various shapes and dimensions. There are the other hardening techniques including the electric furnace method and the induction method. These methods require post-processing for deformation correction, whereas the proposed method uses a laser to achieve thermal deformation-free hardening, eliminating the need for the post-processing. As a result, an improvement in yield can be expected due to a reduction of the products that cannot be corrected after heat treatment, which had to be waste disposed with conventional methods. By using our method, the entire circumference of the shaft was hardened by using a ring-shaped laser beam and a cylindrical inner mirror. Here, the ring-shaped laser beam was formed by high-speed scanning of a spot shapelaser. In the present paper, the details of this system were introduced and some experimental results were described.

A Magnetic Bearing System for More-Electric Engines

2000 ◽  
Author(s):  
R. Jett Field ◽  
Christopher K. Sortore ◽  
Victor Iannello
Keyword(s):  
High Speed ◽  
High Performance ◽  
Fault Tolerant ◽  
High Reliability ◽  
Industrial Applications ◽  
Magnetic Bearing ◽  
Tip Clearance ◽  
Critical Components ◽  
Maintenance Requirements ◽  
Bearing System

Magnetic bearing systems for more-electric engines (MEEs) are under development for aircraft and industrial applications to improve performance and reduce maintenance requirements. Key features of the magnetic bearing system are high performance, high temperature actuators with integrated sensors; a high speed digital controller; a high reliability, fault-tolerant system architecture; modular amplifiers; active control of tip clearance; and adaptive control algorithms. Critical components of the magnetic bearing system have been demonstrated in an engine manufacturer’s rotordynamic test stand and other components are in various stages of development.

Based on Fluid Digital Transmission and Control Theory on Application of Digital Hydraulic Valve

2012 ◽  
Vol 619 ◽  
pp. 455-458
Author(s):  
Wen Hua Li ◽  
Yu Ling Du
Keyword(s):  
Control Theory ◽  
Hydraulic System ◽  
High Speed ◽  
High Efficiency ◽  
Simulation Analysis ◽  
High Reliability ◽  
Electronic Control Unit ◽  
System Pressure ◽  
Analysis Experiment ◽  
Hydraulic Valve

A digital hydraulic valve is a new control theory and method, it is through the electronic control unit installed in a conventional valve, and integrated processing, the formation of a wide variety of digital valve，By the digital-to-analog conversion element is directly connected with the computer. Using the computer output pulse number and frequency to control electro hydraulic system pressure and measurement. The system proposed can make the hydraulic system has the advantages of high efficiency, high speed, high reliability. And used Matlab/Simulink software to control system performance simulation analysis, experiment and simulation results show that, this system has great application prospect and practical value.

Capillary electrophoresis based on nucleic acid detection for diagnosing human infectious disease

2016 ◽  
Vol 54 (5) ◽  
Author(s):  
Dong-Sheng Lian ◽  
Shu-Jin Zhao
Keyword(s):  
Capillary Electrophoresis ◽  
Nucleic Acid ◽  
Infectious Diseases ◽  
High Speed ◽  
High Efficiency ◽  
Disease Diagnosis ◽  
Nucleic Acid Detection ◽  
High Morbidity ◽  
Biochemical Tests ◽  
Short Period

AbstractRapid transmission, high morbidity, and mortality are the features of human infectious diseases caused by microorganisms, such as bacteria, fungi, and viruses. These diseases may lead within a short period of time to great personal and property losses, especially in regions where sanitation is poor. Thus, rapid diagnoses are vital for the prevention and therapeutic intervention of human infectious diseases. Several conventional methods are often used to diagnose infectious diseases, e.g. methods based on cultures or morphology, or biochemical tests based on metabonomics. Although traditional methods are considered gold standards and are used most frequently, they are laborious, time consuming, and tedious and cannot meet the demand for rapid diagnoses. Disease diagnosis using capillary electrophoresis methods has the advantages of high efficiency, high throughput, and high speed, and coupled with the different nucleic acid detection strategies overcomes the drawbacks of traditional identification methods, precluding many types of false positive and negative results. Therefore, this review focuses on the application of capillary electrophoresis based on nucleic detection to the diagnosis of human infectious diseases, and offers an introduction to the limitations, advantages, and future developments of this approach.

Centrifugal Compressor Working Fluids for Refrigeration Cycle

2009 ◽  
Author(s):  
Pekka Ro¨ytta¨ ◽  
Juha Honkatukia ◽  
Teemu Turunen-Saaresti
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Working Fluid ◽  
Accurate Estimation ◽  
Cooling Power ◽  
Condensation Temperature ◽  
Refrigeration Cycle ◽  
Light Weight ◽  
Centrifugal Compressors ◽  
Working Fluids

A centrifugal high-speed compressor is an effective light weight option to power a refrigeration cycle for air conditioning purposes. Perhaps the most important decision in design is the working fluid selection. Modern high-speed technology makes it possible for the refrigeration compressor to be completely oil free, which considerably broadens the scale of possible working fluids. Furthermore, many traditional fluids have become banned and the industry standard R134a might face the same faith in some European countries because of its relatively high global warming potential. In this study eleven different fluids were studied and compared and R22 was used as a reference. It was found that there are many potential fluids for centrifugal compressors that provide better efficiencies than the most common fluids in use today. The purpose of this study is to initially screen a larger set of candidate fluids for more accurate estimation later on. The fluids are evaluated by the efficiency of the cycle, but also mechanical feasibility and dimensions are considered as light weight of the machinery was an important criterion in design process. The comparison was made with constant evaporation and condensation temperature and fixed cooling power for all the fluids. In selection of the working fluid the safety factors often play a dominant role which was also shortly considered. In our study we found out that for a residential HVAC size cooling cycle there are environmentally friendly fluids with high efficiency leading to feasible mechanical designs with centrifugal compressors.

scholarly journals Development and Application of Integrated Aerodynamic Protuberant Foil Journal and Thrust Bearing in Turboexpander

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Tianwei Lai ◽  
Yu Guo ◽  
Wei Wang ◽  
Yu Wang ◽  
Yu Hou
Keyword(s):  
High Speed ◽  
Least Square Method ◽  
Air Separation ◽  
Least Square ◽  
Thrust Bearings ◽  
Foil Bearings ◽  
Foil Bearing ◽  
Rotor Bearing ◽  
Speed Up ◽  
Bearing System

Foil bearing provides compliant support and moderate Coulomb friction for rotor-bearing system, which is conducive to stability and reliability of high speed rotating machinery. In this paper, both hydrodynamic lubricated foil journal and foil thrust bearings are applied in a 150 m3·h−1 turboexpander for air separation. In the bearings, protuberant foil is chosen as the supporting subfoil due to its merits of easy fabrication and assembly. Static loading and deflection of the bearings are tested, respectively, before integration into the turboexpander. Afterwards, the loading and deflection curves of the journal and thrust bearings are polynomial fitted using least-square method. Then, performance tests are carried out on the rotor-bearing system, including transient speed-up, high speed, and speed-down processes. In the tests, the turboexpander supported by the hydrodynamic foil bearings operates smoothly with repeatability. Maximal rotor speed of the turboexpander reaches 52000 rpm with hydrodynamic lubricated protuberant foil bearings.

scholarly journals Targeted mutagenesis of the ryanodine receptor by Platinum TALENs causes slow swimming behaviour in Pacific bluefin tuna (Thunnus orientalis)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kentaro Higuchi ◽  
Yukinori Kazeto ◽  
Yuichi Ozaki ◽  
Toshiya Yamaguchi ◽  
Yukinori Shimada ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
High Speed ◽  
High Efficiency ◽  
Functional Characterization ◽  
Bluefin Tuna ◽  
Targeted Mutagenesis ◽  
Swimming Behaviour ◽  
Pacific Bluefin Tuna ◽  
Thunnus Orientalis ◽  
Short Period

Abstract In bluefin tuna aquaculture, high mortalities of hatchery-reared juveniles occur in sea cages owing to wall collisions that are caused by high-speed swimming in panic due to changes in illuminance. Here, we report that targeted gene mutagenesis of the ryanodine receptor (RyR1b), which allows the sarcoplasmic reticulum to release Ca2+ in fast skeletal muscle, using highly active Platinum TALENs caused slow swimming behaviour in response to external stimuli in Pacific bluefin tuna (PBT) larvae. This characteristic would be a useful trait to prevent wall collisions in aquaculture production. A pair of Platinum TALENs targeting exons 2 and 43 of the PBT ryr1b gene induced deletions in each TALEN target site of the injected embryos with extremely high efficiency. In addition, ryr1b expression was significantly decreased in the mutated G0 larvae at 7 days after hatching (DAH). A touch-evoked escape behaviour assay revealed that the ryr1b-mutated PBT larvae swam away much less efficiently in response to mechanosensory stimulation at 7 DAH than did the wild-type larvae. Our results demonstrate that genome editing technologies are effective tools for determining the functional characterization of genes in a comparatively short period, and create avenues for facilitating genetic studies and breeding of bluefin tuna species.

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