The displacement of a piston compressor usually refers to the volume of exhaust gas measured at the exhaust end of the compressor per unit time, converted into the first-stage suction conditions of the compressor (pressure, temperature, humidity, etc.) numerical value. Its common unit is m3/min or m3/h. However, when converting, you should pay attention to the following two points:
1) For the actual gas, the influence of the gas compression factor should be taken into account when converting;
2) For the gas containing water vapor, the partial pressure of water vapor is also increased after compression, and the gas may condense moisture in the intercooler and be separated in the liquid-gas separator.
When making a rough estimate, consider dry gas. According to the gas volume value Qd (m3/min) measured at the last stage, the exhaust volume Q0 (m3/min) is the gas pressure corresponding to Pa--Qd in the formula, MPa; the gas temperature corresponding to Td--Qd , K; p1--the gas pressure in the first-stage inlet state of I:1, MPa; T1--the gas temperature in the first-stage inlet state, K.
For small piston compressors, the volumetric method is often used to calculate the displacement. Discharge for large compressors is measured with a flow meter. When testing with air, the exhausted pressurized air is often discharged directly into the atmosphere through a flow meter. At this time, the displacement of the compressor can be calculated directly according to the calculation formula of the flowmeter, and then the precipitated water is added.