What is the practical maximum compression ratio for a reciprocating compressor?

The practical maximum compression ratio for a reciprocating compressor is generally considered to be 8:1. This value is based on the operational characteristics and limitations of reciprocating compressors, which include the effects of heat transfer, mechanical stresses, and volumetric efficiency.

At a compression ratio of 8:1, the compressor can achieve a good balance between efficiency and the mechanical constraints it faces. As the compression ratio increases, the discharge temperatures and pressures also rise, which can lead to inefficiencies and potential damage to the compressor. Operating beyond this 8:1 ratio may result in excessive heat and reduced lubrication effectiveness, leading to maintenance issues or even operational failure.

In contrast, lower compression ratios, such as 4:1 or 6:1, are generally more manageable in terms of heat and efficiency, but they do not take full advantage of the compression capabilities of the system. A compression ratio of 10:1 may push the compressor beyond its practical limits, increasing the likelihood of thermal and mechanical problems.

Thus, the choice of 8:1 as the practical maximum is rooted in the need to optimize performance while maintaining reliability in the operational context of industrial ammonia refrigeration systems.