Variable Bleed Valve Control Logic for Turbine Actuator Life

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Solution Overview

Problem

The frequent and rapid position changes in variable bleed valve systems of turbine systems lead to decreased valve efficiencies, resulting in premature wear and increased maintenance costs due to valve dithering and chatter.

Innovation Solution

Implementing semi-freeze logic in the valve system, which includes a controller that determines the operational mode based on turbine system data measurements, reducing the frequency and magnitude of valve actuations by transitioning between full-freeze, semi-freeze, and full-operation modes to manage airflow and extend valve actuator life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the valve actuator responds rapidly to position change commands (100 times per second), then the system response speed is improved, but the valve actuator life decreases due to frequent actuations

Engineering Contradiction:

Improvevalve response speedVSAvoidvalve actuator life

Core Design Contradiction:

SpeedVSDuration of action of stationary object

Solution Approach 1:

The patent applies dynamics by implementing a multi-mode control system that dynamically adjusts the valve actuation behavior based on real-time system conditions. The controller transitions between full-freeze mode (suspending actuation), semi-freeze mode (reduced actuation rate), and full-operation mode (rapid actuation), allowing the system to optimize between response speed and actuator life depending on operational requirements

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the actuation parameters (frequency and magnitude) based on system state. By monitoring turbine system data measurements and comparing them against thresholds, the controller adjusts the position demand update rate and valve actuation magnitude, switching between different operational modes to balance performance and component longevity

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If the valve position demand is updated frequently, then the system control precision is improved, but the valve dithering and chatter increase causing wear

Engineering Contradiction:

Improvevalve position control precisionVSAvoidvalve wear from dithering

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent implements periodic action by introducing freeze intervals where position demand updates are suspended. During full-freeze mode, no position demand changes are provided to the actuator for a predetermined interval, allowing the valve to stabilize and preventing continuous dithering. This periodic suspension of control updates reduces wear while maintaining control precision when needed

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS10168716B2Valve position demand systems and methods

Publication Date: 2019.01.01 GE INFRASTRUCTURE TECH LLC

AI summary

A method includes: obtaining a measurement; determining whether the measurement is in a first range, a second range, or a third range; controlling operation of a valve in a full-freeze mode when the data measurement falls within the first range; controlling the operation of the valve of the turbine system in a semi-freeze mode when the data measurement falls within the second range; and controlling the operation of the valve of the turbine system in a full-operation mode when the data measurement falls within the third range.