Selection of centrifugal compressors
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I am currently designing a high-pressure natural gas process that requires compressing natural gas from 2 MPa to 9.5 MPa, and I am unsure whether to use a centrifugal compressor or a reciprocating compressor. Another issue is that the single-stage compression ratio of centrifugal compressors is roughly in that range; I remember that for reciprocating compressors it’s between 3 and 4. Moreover, a characteristic of centrifugal compressors is that the single-stage compression ratio is not high; however, I read in a source that the single-stage compression ratio for centrifugal compressors ranges from 2 to 4, which seems contradictory. Could some expert give me some advice?
The choice of type depends on your specific circumstances, mainly the volume of gas to be compressed. Centrifugal compressors are suitable for large volumes of gas; although they are more expensive, they require less maintenance. Generally, no backup unit is needed. Reciprocating units, such as piston and screw compressors, are suitable for smaller volumes of gas. Piston compressors tend to fail more often, so a backup unit is usually necessary. Your pressure level is quite suitable for a centrifuge; a two-stage centrifuge will suffice. Of course, the pressure level is also very appropriate for a reciprocating machine.
Thank you for the introduction from the second floor. But can secondary centrifugal compression meet the requirements? The single-stage compression ratio of the centrifuge seems to be kept within 1.6
The choice mainly depends on your company’s requirements for unit stability and the volume of gas needed. In most cases, both options are available; personally, I recommend using a centrifugal compressor for high flow rates, a piston compressor for medium and low flow rates, and a diaphragm compressor for very low flow rates.
I also want to know the compression ratio of the centrifuge. I heard it’s not high, but I’m not sure exactly how much. If anyone knows, please let me know!
If the gas flow rate is stable, it’s better to use a centrifugal machine for one batch; if the gas flow rate drops rapidly, it’s best to use a reciprocating machine