Improving The Process For Sizing Reciprocating Compressors
Posted by IAP on 01/10/2025
The task of sizing reciprocating compressors goes back many decades. Today, most reciprocating compressor OEMs provide powerful sizing software to aid engineers, packagers and end users. Nevertheless, without proper care and attention to detail, these sizing tools may generate misleading and undesirable hardware suggestions. Therefore, a fundamental understanding of the sizing process empowers users with the knowledge of what’s really happening when they click on the mysterious Auto Size button.
Finding Solutions Based On A Single Design Point — The Classic Approach
A typical compressor sizing methodology proceeds as follows:
1. Inlet and discharge pressures and a desired flow rate are specified.
2. A gas analysis or equivalent is specified.
3. Based on the compression ratio, an estimate of the total number of stages required is determined.
4. Based on required number of stages, interstage pressures are determined.
5. Based on the number of required stages and desired flow rate, an estimate of the power required to compress the volume of gas from inlet pressure to discharge pressure is determined.
6. Based on this power estimate, appropriate OEM frames are determined.
7. Based on unit speed (frame and/or driver), frame stroke, required flow, inlet and discharge pressures, gas analysis and estimated interstage pressures, appropriate OEM cylinders are determined.