Reciprocating Compressor Thermodynamic Capacity without the Thermo
There are almost as many ways of calculating reciprocating compressor capacity as there are organizations performing the task. The fundamental equation is common, but each organization has its own method to account for non--ideal behavior. The general equation entails using an ideal volumetric efficiency (based on pressure and clearance) followed by a preferred subjective correction factor. Depending on the accuracy desired, this methodology is reasonably sufficient for slow speed integral engine/compressor units operating over a relatively small compression ratio range; however a new technique is required for accurate capacity prediction while operating over varying speed and compression ratio ranges, and in different load steps and/or compressor end deactivation. This paper will discuss a technique that will provide accurate reciprocating compressor capacity at any operating condition with varying speed, clearance, compression ratio, and deactivation.