Screw Compressors (eBook)

Mathematical Modelling and Performance Calculation

Nikola Stosic, Ian Smith, Ahmed Kovacevic (Autoren)

eBook Download: PDF

2005 | 1. Auflage
XI, 138 Seiten
Springer-Verlag
978-3-540-26228-2 (ISBN)

Infos

Althoughtheprinciplesofoperationofhelicalscrewmachines,ascompressors or expanders, have been well known for more than 100 years, it is only during the past 30 years that these machines have become widely used. The main reasons for the long period before they were adopted were their relatively poor e?ciency and the high cost of manufacturing their rotors. Two main developments led to a solution to these di?culties. The ?rst of these was the introduction of the asymmetric rotor pro?le in 1973. This reduced the bl- hole area, which was the main source of internal leakage by approximately 90%, and thereby raised the thermodynamic e?ciency of these machines, to roughly the same level as that of traditional reciprocating compressors. The second was the introduction of precise thread milling machine tools at - proximately the same time. This made it possible to manufacture items of complex shape, such as the rotors, both accurately and cheaply. From then on, as a result of their ever improving e?ciencies, high rel- bility and compact form, screw compressors have taken an increasing share of the compressor market, especially in the ?elds of compressed air production, and refrigeration and air conditioning, and today, a substantial proportion of compressors manufactured for industry are of this type. Despite, the now wide usage of screw compressors and the publication of many scienti?c papers on their development, only a handful of textbooks have been published to date, which give a rigorous exposition of the principles of their operation and none of these are in English.

Inhalt

Preface 5
Notation 7
Contents 9
1 Introduction 12
1.1 Basic Concepts 15
1.2 Types of Screw Compressors 18
1.3 Screw Machine Design 19
1.4 Screw Compressor Practice 21
1.5 Recent Developments 23
2 Screw Compressor Geometry 30
2.1 The Envelope Method as a Basis for the Profiling of Screw Compressor Rotors 30
2.2 Screw Compressor Rotor Profiles 31
2.3 Rotor Profile Calculation 34
2.4 Review of Most Popular Rotor Profiles 34
2.5 Identification of Rotor Position in Compressor Bearings 51
2.6 Tools for Rotor Manufacture 56
3 Calculation of Screw Compressor Performance 60
3.1 One Dimensional Mathematical Model 60
3.2 Compressor Integral Parameters 70
3.3 Pressure Forces Acting on Screw Compressor Rotors 72
3.4 Optimisation of the Screw Compressor Rotor Profile, Compressor Design and Operating Parameters 76
3.5 Three Dimensional CFD and Structure Analysis of a Screw Compressor 82
4 Principles of Screw Compressor Design 88
4.1 Clearance Management 89
4.2 Calculation Example: 5- 6- 128mm Oil- Flooded Air Compressor 93
5 Examples of Modern Screw Compressor Designs 100
5.1 Design of an Oil-Free Screw Compressor Based on 3- 5 N” Rotors 101
5.2 The Design of Family of Oil- Flooded Screw Compressors Based on 4- 5 N” Rotors 104
5.3 Design of Replacement Rotors for Oil- Flooded Compressors 107
5.4 Design of Refrigeration Compressors 111
5.5 Multifunctional Screw Machines 119
6 Conclusions 128
A Envelope Method of Gearing 130
B Reynolds Transport Theorem 134
C Estimation of Working Fluid Properties 138
References 144

Produkt-Details

• Erscheint lt. Verlag: 5.12.2005
• Zusatzinfo: XI, 138 p.
• Verlagsort: Berlin
• Sprache: englisch
• Themenwelt: Technik ► Architektur
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Maschinenbau
• Schlagworte: Design • fluid mechanics • Mathematical Modelling • Mechanics • Profil • Rotor • Screw Compressor
• ISBN-10: 3-540-26228-8 / 3540262288
• ISBN-13: 978-3-540-26228-2 / 9783540262282