Compressor Controls Corporation

Energy Control Technologies, Inc.

Krishnan Narayanan

Paul Reinke

Saul Mirsky

Brett W Batson

Naum Staroselsky

Paul F Fisher

Nikhil Dukle

A method of surge protection for a dynamic compressor that has a corresponding compressor map. A control system continually calculates an equivalent polytropic head parameter in order to define a surge limit line. The system then calculates a control parameter and determines the distance the control parameter to the surge limit line wherein the control parameter is dynamic to changes in gas compressibility and invariant to changes in suction conditions and gas compressibility. As a result of the distance of the control parameter to the surge limit line, the surge valve of a dynamic compressor is actuated to prevent surge.

Method of anti-surge protection for a dynamic compressor using a surge parameter

A method of preventing surge in a dynamic compressor is disclosed. The method includes providing an anti-surge valve having an adjustable opening for increasing the flow through a dynamic compressor. The next step is sensing process conditions in the dynamic control to determine a compressor load variable. A control system estimates a process disturbance model using the compressor load variable. The control system then adjusts a safety margin using a rate limited response and initiates a closed loop response using process feedback based on the process disturbance model. The control system adjusts the opening of the anti-surge valve according to the safety margin and closed loop response.

Method for preventing surge in a dynamic compressor using adaptive preventer control system and adaptive safety margin

A method of correcting surge control parameters that includes providing a dynamic compressor having a compressor, driver, surge valve, and control system. The control system establishes surge control parameters such as surge detection lines, surge limit lines, and then detects the onset of a surge in the dynamic compressor. When the surge is detected the control system measures variables of the dynamic compressor such as fluid pressure, fluid speed, power, speed and valve position and based on these variables the control system automatically corrects the surge control parameters based on these variables at the time of the onset of the surge is detected. Advisory information is provided by control system to user for corrective actions to prevent surge.

Surge estimator

Many variables in processes such as those using turbocompressors and turbines must be limited or constrained. Limit control loops are provided for the purpose of limiting these variables. By using a combination of closed loop and open loop limit control schemes, excursions into unfavorable operation can be more effectively avoided. Transition between open loop and closed loop may be enhanced by testing the direction and magnitude of the rate at which the limit variable is changing. If the rate of change indicates recovery is imminent, control is passed back to the closed loop limit control function.

Apparatus for the prevention of critical process variable excursions in one or more turbomachines

Method and apparatus for the prevention of critical process variable excursions in one or more turbomachines

Often, an application or process calls for multiple pumps operating within a piping network. Pump load, such as flow rate or pressure, is shared between these multiple pumps. The present disclosure relates to effective means of distributing the pumping load in a manner that satisfies the process requirements while keeping the pumping machinery safe from functioning in damaging operating regions. It also discloses a method of operating pumps in an efficient or optimal fashion. An additional aspect is a method of using an open-loop response to deal with large transients threatening to force a pump into an operating region that might result in damage or destruction.

Controlling multiple pumps operating in parallel or series

A method is provided for controlling fuel flow to the combustor of a gas generator turbine during sudden changes in load or during a surge cycle of the process turbocompressor. Surge control is initiated by analog input signals emanating from various devices located throughout the compressor-process system. The fuel control system includes input signals from the gas turbine driver. These signals are acted upon by the fuel control system which transmits a signal to a fuel valve actuator that controls the valve that meters fuel to the combustor. In addition to this sequence of control communication, however, is a rate-of-change in the amount of the fuel provided. The rate of the increase of the amount of fuel is determined by current operating functions of the fuel control system. However, because of the characteristics of general load rejection and recovery, and the abrupt nature of surge, the rate of change in the flow rate of fuel is extremely high. This rapid increase of fuel to the combustor may lead to dangerous excursions in temperature, resulting in high temperatures in gas turbine elements. Consequently, a new function is added to the fuel control system's operation whereby improved regulation of the rate of increase of fuel is achieved. This new function receives a signal that either surge or a change in load has been detected. Next, a signal is transmitted to the fuel valve actuator, regulating fuel to the combustor, thus power to the power turbine, thereby preventing overspeeding. After that, the rate of change of the fuel valve is limited for a period of time. Once recovery has been accomplished, the change rate of the fuel valve is gradually returned to a normal operating setting.

Prevention of parameter excursions during process compressor surge in

An improved method is provided for controlling fuel flow to the combustor of a gas generator turbine during sudden changes in load or during a surge cycle of the process turbocompressor. Surge control is initiated by analog input signals emanating from various devices located throughout the compressor-process system. The fuel control system includes input signals from the gas turbine driver. These signals are acted upon by the fuel control system which transmits a signal to a fuel valve actuator that controls the valve that meters fuel to the combustor. In addition to this sequence of control communication, however, is a rate-of-change in the amount of the fuel provided. The rate of the increase of the amount of fuel is determined by current operating functions of the fuel control system. However, because of the characteristics of general load rejection and recovery, and the abrupt nature of surge, the rate of change in the flow rate of fuel is extremely high. This rapid increase of fuel to the combustor may lead to dangerous excursions in temperature, resulting in high temperatures in gas turbine elements. Consequently, a new function is added to the fuel control system's operation whereby improved regulation of the rate of increase of fuel is achieved. This new function receives a signal that either surge or a change in load has been detected. Next, a signal is transmitted to the fuel valve actuator, regulating fuel to the combustor, thus power to the power turbine, thereby preventing overspeeding. After that, the rate of change of the fuel valve is limited for a period of time. Once recovery has been accomplished, the change rate of the fuel valve is gradually returned to a normal operating setting.

Prevention of parameter excursions in gas turbines

A method and apparatus are disclosed for protecting turbocompressors from unstable flow conditions (surge and stall). To accomplish this, it is necessary to easily and accurately calculate a compressor's operating point and its distance from the interface between the surge region and the stable region--this interface is referred to as the Surge Limit Interface. The proximity of the operating point to the Surge Limit Interface is calculated using measurements of properties throughout the compressor-process system. It is crucial that the calculation be invariant to suction conditions, especially gas composition. Disclosed are three coordinates, T.sub.r (reduced torque), P.sub.r (reduced power), and N.sub.e (equivalent speed). Each of these can be combined with other invariant parameters to construct coordinate systems in which to define the Surge Limit Interface and measure the distance of the operating point to that interface.

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West Des Moines, IA, United States of America

Krishnan Narayanan