Two-stage reciprocating compressor optimization control system

A method comprising:

• operating a reciprocating compressor with a control system having a dual-mode model having a measurement mode and a tuning mode, wherein operating comprises:
• receiving one or more inputs into the dual-mode model measured from the reciprocating compressor during operation thereof;
• and
• in response to receipt of the one or more inputs, executing the dual-mode model in at least one of the measurement mode and the tuning mode, wherein:
• in the measurement mode, execution of the dual-mode model further comprises calculating an actual flow rate of gas in the reciprocating compressor based on the one or more inputs;
• in the tuning mode, execution of the dual-mode model further comprises calculating one of an unloader setting and a speed set point of a physical element of the reciprocating compressor for a desired flow rate of gas, wherein the reciprocating compressor is a two-stage reciprocating compressor, including a first stage for lower pressure and a second stage for higher pressure;
• setting a flow rate of gas and a minimum unloader setting for each of the first stage and the second stage;
• calculating a shaft speed set point via application of the tuning mode of the dual-mode model for the set flow rate;
• determining if the speed set point is greater than a minimum speed and less than a maximum speed;
• increasing the minimum unloader setting associated with the first stage when the minimum speed is greater than the speed set point;
• decreasing the set flow rate of gas when the speed set point is greater than the maximum speed;
• and
• increasing the minimum unloader setting associated with the second stage when an inter-stage pressure is lower than an optimum value.