Usually, an alarm of low inlet pressure is set to ensure the safe operation of the compressor. If the back pressure of the system is low, the exhaust pressure of the compressor will be reduced accordingly, and maintaining the pressure ratio equal to or lower than the original design pressure ratio can ensure the normal operation of the compressor and reduce the load of the compressor. On the contrary, if the pressure ratio increases and the exhaust temperature and load increase, the compressor cannot operate normally, so we must try to improve the inlet pressure.
When the primary inlet pressure increases, if the outlet back pressure keeps the original design value, the pressure ratio decreases, which is beneficial to the operation of the compressor, but the pressure increase is limited by the pressure bearing capacity of the compressor inlet buffer tank, compressor cylinder and other equipment. The exhaust pressure is mainly determined by the system pressure and the pressure drop of compressor outlet buffer tank, cooler, separator and check valve.
In order to prevent the occurrence of coking and carbon deposition in the compressed medium, it is generally stipulated that the exhaust temperature of the compressor should not exceed a certain value, or a high alarm stop should be set to ensure the safe operation of the compressor, so the exhaust temperature should be controlled within the specified range. The increase of inlet air temperature leads to the further increase of compressor exhaust temperature, so it is necessary to control the inlet air temperature at all stages of the compressor.
