Fuel Nozzle Cooling Airflow for Post-Shutdown Carbon Control
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Solution Overview
Problem
Gas turbine engine components experience residual heat soakback after shutdown, leading to excessive temperatures and carbon deposits in fuel carrying components, causing engine issues and inefficiencies.
Innovation Solution
A fuel nozzle thermal management system comprising a fan and a conditioning duct that directs cooling air to fuel nozzles, manifolds, and drain lines via jets or direct airflow, using electrically driven fans or ram air, to manage thermal energy post-shutdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If cooling systems are shut down during engine shutdown, then energy consumption is reduced, but component temperatures exceed allowable limits causing carbon deposits
Solution Approach 1:
The cooling fan operates periodically rather than continuously - it runs at high speed during engine operation and continues for a predetermined time after shutdown, then stops. This periodic operation reduces energy consumption while still managing thermal loads effectively during the critical post-shutdown period when carbon deposits form.
Solution Approach 2:
The control system activates the cooling fan in advance before engine shutdown occurs, and maintains operation for a predetermined time after shutdown. This preliminary and extended action ensures that component temperatures are managed during the critical transition period when residual heat causes thermal imbalance and carbon deposit formation in fuel nozzles.
2Temperature
If cooling fan operates continuously, then component temperatures are maintained within limits, but energy consumption increases
Solution Approach 1:
The cooling fan operates periodically rather than continuously - it runs at high speed during engine operation and continues for a predetermined time after shutdown, then stops. This periodic operation reduces energy consumption while still managing thermal loads effectively during the critical post-shutdown period when carbon deposits form.
3Device complexity
If cooling air is not directed to fuel nozzles, then system complexity is reduced, but carbon deposits form causing engine failures
Solution Approach 1:
A conditioning duct is introduced as an intermediary component that directs cooling air from the fan to the fuel nozzles and fuel carrying components. This relatively simple duct structure enables targeted thermal management of critical components without requiring complex active cooling systems, thereby maintaining engine reliability while avoiding excessive system complexity.
Solution Approach 2:
The conditioning duct directs cooling air specifically to fuel nozzles and fuel carrying components that are most susceptible to carbon deposits. This localized cooling approach applies thermal management only where needed rather than cooling the entire engine uniformly, maintaining reliability in critical areas without excessive system complexity.
4Object-affected harmful factors
If thermal management system is added, then carbon deposits are reduced, but device complexity increases
Solution Approach 1:
A conditioning duct is introduced as an intermediary component that directs cooling air from the fan to the fuel nozzles and fuel carrying components. This relatively simple duct structure enables targeted thermal management of critical components without requiring complex active cooling systems, thereby maintaining engine reliability while avoiding excessive system complexity.
Solution Approach 2:
The existing cooling fan is utilized to provide cooling air through the conditioning duct to fuel nozzles. The system leverages already-present components (the fan) and directs its output through a simple duct structure, rather than introducing entirely new active cooling mechanisms. This self-service approach reduces carbon deposits without significantly increasing device complexity.
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
Effectively reduces carbon deposits and maintains component temperatures within safe limits, preventing engine start issues and improving combustion efficiency.
Implementation Method 1
A fuel nozzle thermal management system comprising a fan fluidly coupled with at least one of a fuel nozzle, a fuel manifold, an external fuel supply, and a fuel drain line proximate a combustor
Implementation Method 2
temperatures of gas turbine engine components are maintained within allowable limits by a plurality of cooling processes that transfer heat from the components to one or more heat sinks
Data Source
Figure 1
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AI summary
A fuel nozzle thermal management system including a fan fluidly coupled with at least one of a fuel nozzle, a fuel manifold, an external fuel supply, and fuel drain lines proximate a combustor.