Turbine Trip Control System with Redundant Block and Bleed Valves
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Solution Overview
Problem
Existing turbine trip control systems lack redundancy and remote testing capabilities for the block circuit, leading to potential failures and manual operation challenges, which can result in unsafe and costly situations during emergency trips.
Innovation Solution
A tripping control system with redundant blocking and bleed valves actuated by a controller, allowing for individual component testing during turbine operation without causing a trip, and integrating these components into a compact package for easy retrofitting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a purely mechanical trip control system is used, then the system is simple in design, but it lacks redundancy and requires manual operation for testing which reduces reliability and increases operational complexity
Solution Approach 1:
The trip control system is segmented into multiple independent control valves (at least two) that can operate separately. Each valve controls a portion of the hydraulic fluid flow to the steam valve, allowing individual testing and operation without affecting the entire system. This segmentation provides redundancy while maintaining manageable system complexity.
Solution Approach 2:
The system incorporates preliminary testing capability where control valves can be tested individually while the turbine is operating. This allows verification of valve functionality before an actual trip is needed, ensuring reliability without requiring manual intervention during emergencies. The test mode can be activated remotely without causing a full trip sequence.
2Ease of operation
If manual operation of block circuit components is required, then the system is simpler to manufacture, but it requires operator presence at the turbine site which reduces ease of operation and increases response time
Solution Approach 1:
Manual mechanical operation of block circuit components is replaced with electronically controlled valves. The control system receives electrical signals to actuate the valves, enabling remote operation from the control room. This substitution maintains relatively simple manufacturing while dramatically improving ease of operation and reducing response time for trip events.
3Reliability
If redundant control valves are implemented, then the system provides better reliability, but it increases the number of components and system complexity
Solution Approach 1:
Multiple control valves are merged into a unified control architecture where they share common control logic and hydraulic circuits. The valves operate in parallel but are integrated through a single control system that can address them individually or collectively. This merging approach provides redundancy while minimizing the increase in overall system complexity through shared components and control pathways.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures reliable trip operations with redundant block and bleed functionality, enabling remote testing and reducing the need for manual intervention, thus enhancing safety and reducing operational costs.
Implementation Method 1
a block circuit having two or more redundant blocking valves connected in series within a pressure supply line to block the supply of hydraulic fluid within the pressure supply line
Implementation Method 2
a bleed circuit having two or more bleed valves connected in parallel between the trip line and a return or dump line to bleed to the hydraulic fluid from the trip
Data Source
AI summary
A tripping control system for use with, for example, turbines, includes a block circuit having two or more redundant blocking valves disposed or connected in series within a pressure supply line to block the supply of hydraulic fluid within the pressure supply line and a bleed circuit having two or more bleed valves connected in parallel between the pressure supply line and a return or dump line to bleed to the hydraulic fluid from the pressure supply line. The blocking valves and the bleed valves are actuated by one or more control valves under the control of a process or safety controller which trips the turbine by first performing a bleed function using the bleed valves, which then causes the block function to automatically actuate. Pressure sensors disposed at various locations in the tripping control system provide feedback to the controller to enable the controller to test each of the block and bleed valves individually, during operation of the turbine, without causing an actual trip of the turbine. The tripping control system thereby provides reliable trip operation during a trip by providing redundant block and bleed functionality in combination with enabling the individual components of the block and bleed circuits to be tested while the turbine is online and operating but without preventing the turbine from being tripped, if necessary, during the test.