This disclosure describes a novel methodology for anti-surge and anti-choke control systems protecting centrifugal and axial compressors. The methodology, based on Buckingham's π-theorem for compressors, presents compressor performance maps in dimensionless rectangular π-term coordinates that are independent of compressor inlet conditions, fluid molecular weight and rotational speed. The full range of compressor operating points from surge to choke is monitored and controlled when surge and choke limits are available. This is accomplished by converting rectangular coordinates presented in π-terms to polar coordinates, and then converting them to a controlled variable used in the closed-loop controllers. The methodology provides control algorithms for variable speed compressors, variable geometry compressors equipped with inlet guide vanes or stator vanes that exhibit displacement of surge and choke limits. The methodology most accurately estimates the location of the operating point relative to its limit in polar coordinates if only the surge or choke limit is available. The presented protection methods are applicable to any known types of dynamic compressors for industrial, commercial, jet engines, turbochargers.

A compressor control system includes: a compressor; an inlet guide vane (IGV) arranged at an inlet of the compressor, and configured to adjust opening of the inlet based on a supplementary surge control signal or a performance control signal; an anti-surge valve (ASV) connected to an outlet of the compressor, and configured to prevent a surge based on a surge control signal; and a controller configured to generate the surge control signal for controlling the ASV when an operating point enters a surge control range, generate the supplementary surge control signal for controlling the IGV in an anti-surge mode when the operating point enters a supplementary surge control range set between the surge control range and a surge range, and generate the performance control signal for controlling the IGV in a performance mode until the operating point enters the surge control range.

The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.

A vacuum exhaust apparatus capable of accurately and rapidly adjusting the pressure in an exhaust chamber and a vacuum pump used therein are provided. A vacuum pump includes a rotor that rotates to exhaust an exhaust chamber and a casing having an inlet port. A valve is located between the inlet port of the vacuum pump and an outlet port of the exhaust chamber. A controller performs control such that the pressure in the exhaust chamber matches a target value. The controller adjusts the opening degree of the valve when the absolute value of the difference between the pressure in the exhaust chamber and the target value is greater than a predetermined value, and adjusts the rotational speed of the rotor of the vacuum pump when the absolute value of the difference between the pressure in the exhaust chamber and the target value is less than the predetermined value.

Energy efficiency and/or operational stability of a multistage compression system comprising a plurality (N) of centrifugal compressors that is compressing a gas feed having a variable flow rate is improved by adjusting reversibly the load on each compressor in response to changes in the flow rate of the gas feed using a main recycle system to enable operation of the centrifugal compressors at turndown capacity during periods when the flow rate is below total turndown capacity for all of the compressors, and if necessary, using the local recycle systems in order to avoid activation of anti-surge control, and switching one or more centrifugal compressors into low power mode or shutdown mode as required.

Methods and systems for controlling a bleed-off valve of a gas turbine engine are described. The method comprises maintaining a first bleed-off valve associated with a first compressor of the gas turbine engine at least partially open upon detection of an unintended engine disturbance causing a drop in pressure of a combustion chamber of the engine; monitoring a rotor acceleration of the first compressor; and controlling closure of the first bleed-off valve when the rotor acceleration of the first compressor reaches a first threshold for a first duration.

An antisurge controller for a turbocompressor system stores multiple control algorithms in a memory for the antisurge controller. The antisurge controller identifies capabilities of field devices in the turbocompressor system. The field devices include an antisurge valve and multiple sensors. The antisurge controller selects one of the multiple control algorithms based on the identified capabilities and applies the selected control algorithm to the turbocompressor system. The selected control algorithm provides the smallest surge control margin, of the surge control margins in the multiple control algorithms, that are supported by the identified capabilities.

The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.

An anti-surge recycle valve system for a natural gas line using a pipeline rotary control valve for controlling gas flow through the gas line and a valve controller having a surge-programmable feature including a threshold setpoint deviation limit, which is used to control first and second control valve loops. The first solenoid valve loop drives a rotary high-pressure piston actuator when the linear position sensor determines a setpoint deviation in gas flow below the threshold deviation, and the second solenoid valve loop drives the rotary high-pressure piston actuator when the linear position sensor determines a setpoint deviation in gas flow above the threshold deviation. The system provides ultra-rapid stroking speed in tandem with highly accurate and stable positioning.

A system for bleeding air from a core flow path of a gas turbine engine is disclosed. In various embodiments, the system includes a bleed valve having a bleed valve inlet configured to receive a bleed air from a first access point to the core flow path and a bleed valve outlet; and an air motor having a first air motor inlet configured to receive the bleed air from the bleed valve outlet and a first air motor outlet configured to exhaust the bleed air, the air motor configured to pump the bleed air from the core flow path of the gas turbine engine.