US 7,094,019 B1 · System and method of surge limit control for turbo compressors

Abstract

A system and method of surge limit control for turbo compressors including a turbo compressor having an inlet and an outlet, an anti-surge valve, a variable speed drive to operate the compressor, a rotational speed transmitter, an inlet temperature transmitter, an inlet pressure transmitter, an outlet pressure transmitter and/or guide vanes, and a controller, the controller including a PID control module wherein the computer uses information from the transmitters to continuously calculate a pressure ratio of the compressor at the compressor's current operational speed and compare it to the compressor's calculated pressure ratio at surge limit conditions. A computer generates a control signal for determining when to open the anti-surge valve if the pressure ratio of the compressor at the compressor's current operational speed guide vanes are within a user defined safety margin to the calculated pressure ratio at surge limit conditions.

Claims3

Dependent claims

A unique method of anti-surge protection for turbo compressor systems, the method comprising:

monitoring a compressor rotational speed or guide vanes position;
monitoring a compressor inlet temperature;
monitoring a compressor inlet pressure;
monitoring a compressor outlet pressure;
calculating a compressor pressure ratio at surge limit conditions for the current inlet temperature, wherein a compressor ratio is based upon a ratio of the current inlet temperature to the given inlet temperature associated with the pressure ratio at the surge limit conditions and the pressure ratio at the surge limit conditions for the given temperature:
calculating a compressor pressure ratio at current operating conditions;
comparing the compressor pressure ratio at the current operating conditions to the compressor pressure ratio at the surge limit conditions;
and
opening an anti-surge valve when the comperssor pressure ratio at the current operating conditions approaches a pre-determined safety margin within the compressor pressure ratio at the surge limit conditions to minimize the possibility that the turbo-compressor would experience a surge.

6 more elements

Dependencies are inferred from the claim text.

System and method of surge limit control for turbo compressors

Life of this patent

System and method of surge limit control for turbo compressors

Life of this patent

Abstract

Claims3