Compressors
PROBLEM:
- Inlet distortions cause the compressor to operate at less than the factory rated flow, head and efficiency
- Interstage hunting caused by non-uniform flow
SOLUTION:
BENEFITS:
- Operates closer to the factory rated flow, head, and efficiency
- Lower suction piping pressure drop
- Reduced energy operating costs
Centrifugal and axial compressor operation and performance are sensitive to velocity and mass distribution at the inlet. The ASME Power Test Code for compressors (PTC-10) requires a fully developed uniform velocity profile entering the compressor OR a minimum straight run of three pipe diameters is required at the straight pipe inlet to produce a flat velocity profile. In field operations, however, compressors do not always have this ideal suction piping configuration.
Poor field suction piping includes single, double and triple elbows immediately upstream of the compressor, which create a considerable amount of distortion. For example, large multistage axial or centrifugal compressors (i.e. a refrigeration compressor) that supply high pressure systems, as shown in Figure 1, can have upstream turns in the suction piping which result in non-uniform mass and flow profiles approaching the splitter in the compressor casing.
The CRV® , when placed on the inlet side of an elbow, produces a flat velocity profile and an even distribution of process gas at the elbow exit. This allows the compressor to more closely approach its factory test inlet conditions and performance curves. Typical CRV® locations in compressor feed piping systems are shown in Figure 1 for multistage compressors and Figure 2 for interstage-cooled compressors.
Figure 2
