From Gas Turbine Engineering Handbook, Third Edition
- Chapter 6: Centrifugal Compressors
- Chapter 7: Axial-Flow Compressors
- Chapter 8: Radial-Inflow Turbines
- Chapter 9: Axial-Flow Turbines
- Chapter 10: Combustors
Centrifugal compressors are used in small gas turbines and are the driven units in most gas turbine compressor trains. They are an integral part of the petrochemical industry, finding extensive use because of their smooth operation, large tolerance of process fluctuations, and their higher reliability compared to other types of compressors. Centrifugal compressors range in size from pressure ratios of 1:3 per stage to as high as 12:1 on experimental models. Discussion here will be limited to pressure ratios below 3.5:1, since this type is prevalent in the petrochemical industry. The proper selection of a compressor is a complex and important decision. The successful operation of many plants depends on smooth and efficient compressor operations. To ensure the best selection and proper maintenance of a centrifugal compressor, the engineer must have a knowledge of many engineering disciplines.
In a typical centrifugal compressor the fluid is forced through the impeller by rapidly rotating impeller blades. The velocity of the fluid is converted to pressure, partially in the impeller and partially in the stationary diffusers. Most of the velocity leaving the impeller is converted into pressure energy in the diffuser as shown in Figure 6-1. It is normal practice to design the compressor so that half the pressure rise takes place in the impeller and the other half in the diffuser. The diffuser consists essentially of vanes, which are tangential...
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Chapter List Chapter 11: Materials Chapter 12: Fuels Overview Temperature limitations are the most crucial limiting factors to gas turbine efficiencies. Figures 11-1a and 11-1b show...
OVERVIEW Diffusers are designed to convert the high velocity exiting from the impeller to static pressure. The velocity in a diffuser is reduced, and the static pressure is increased while the total...
CENTRIFUGAL COMPRESSORS When compared with axial compressors, centrifugal compressors have the following five advantages: They occupy a smaller length than the equivalent axial compressors.
OVERVIEW Centrifugal compressors are used extensively because of their smooth operation, large tolerance of process fluctuations, and their higher reliability compared to other types of compressors.
5.8 Centrifugal Compressors As the name implies, a centrifugal compressor achieves part of the compression process by causing the fluid to move outward in the centrifugal force field produced by the...