Gas Turbine Clearance Control via Dynamic Cooling Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas turbine clearance control systems fail to manage excessive clearance reduction due to abrupt load fluctuations when the blade ring remains cooled during rated operation.
Innovation Solution
A clearance control system for a gas turbine that includes a cooling passage in the stationary part, a combustor internal flow passage, a supply device for cooling medium, and a control device to adjust flow rates based on detected load fluctuations, ensuring appropriate cooling amounts to maintain optimal clearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the blade ring is cooled during rated operation to reduce clearance, then the clearance between stationary part and rotary part is reduced, but the clearance excessively decreases when load fluctuates
Solution Approach 1:
The patent applies dynamics by making the cooling system adjustable rather than fixed. The cooling medium flow rate is dynamically changed based on load conditions: during stable operation, cooling is applied to reduce clearance; during load fluctuations, cooling is reduced to prevent excessive clearance decrease. This dynamic adjustment resolves the contradiction between maintaining precise clearance and adapting to load changes.
Solution Approach 2:
The patent changes the parameter of cooling medium flow rate based on load conditions. By adjusting the flow rate parameter - maintaining higher flow during stable operation for clearance control and reducing flow during load fluctuations - the system achieves both precise clearance control and load adaptability, resolving the technical contradiction.
2Manufacturing precision
If cooling medium flow rate is increased to maintain clearance, then clearance control is improved, but the system cannot respond to abrupt load changes
Solution Approach 1:
The patent implements feedback control where the cooling medium flow rate is continuously adjusted based on detected load conditions. The system monitors operation state and provides feedback to the cooling control mechanism, which adjusts flow rate accordingly - maintaining clearance during stable operation and preventing excessive clearance reduction during load fluctuations, thus improving both clearance maintenance and load response reliability.
Solution Approach 2:
The cooling system transitions from a static fixed flow rate to a dynamic adjustable flow rate that responds to load changes. This dynamic behavior enables the system to maintain clearance control during stable operation while reliably responding to abrupt load changes, resolving the contradiction between clearance maintenance and response reliability.
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
The system effectively reduces cooling of the stationary part during load fluctuations, preventing excessive clearance decrease and enabling the gas turbine to handle varying loads.
Implementation Method 1
a cooling passage which is formed in the stationary part and through which a cooling medium for cooling the stationary part flows
Data Source
AI summary
In a clearance control system for a gas turbine, a control device operates an adjustment device such that a first flow rate is greater than a second flow rate when a load stable state is entered in which a fluctuation range of a load shifts within a preset range, and operates the adjustment device such that the second flow rate is greater than the first flow rate when a load fluctuation state is entered in which the load falls outside the range.