GUIDELINE Screw Compressors Testing CBC （CBC准则螺杆压缩机测试）.pdfVIP

GUIDELINE Screw Compressors Testing Contents 1. Principle of operation and classification of the compressors 2 2. Basic parameters of the compression process. Nature of the compression 4 3. Screw compressors 6 3.1. Construction 6 3.2. Fundamentals of operation7 3.3. Volume Ratio 11 3.4. Capacity Control 13 4. Methods for testing of screw compressors 17 4.1. Testing of pressure distribution in twin screw compressors for multiphase duties 17 4.2. Testing of screw refrigeration compressors under superfeed conditions 19 4.3 Testing of gas screw compressors ( for natural gas or other types of gas ) 23 5. Conclusion 26 6. Bibliography 27 1. Principle of operation and classification of the compressors Compressors are operating pneumatic machines that increasing the potential energy, the pressure of gas or steam by converting them held to the shaft mechanical energy drive motor. All compressors according to the principle of action, which means according to physical phenomena, which are used to transfer energy to gas can be divided into three groups: 1) volume compressors ( positive displacement compressors); 2) dynamic compressors; 3) thermal compressors. In some types of compressors combinations of several ways to increase the pressure have been used. The volume compressors increase the gas pressure by reducing the volume of closed chambers containing a certain amount of gas, which means definite number of molecules of the gas. Reducing the chamber increases the concentration of molecules in unit volume. The pressure of the ambient gas on the walls according to the laws of kinetic energy of the gas is p