Staged Fuel Nozzle Cooling Circuits to Prevent Coking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing staged fuel systems in gas turbine engines face challenges in managing thermal degradation due to coking in stagnant fuel circuits, leading to performance degradation and maintenance needs, particularly during low power operation.
Innovation Solution
A fuel system with integrated cooling circuits in each nozzle, allowing coolant circulation through these circuits to prevent thermal degradation, including a coolant manifold system for efficient cooling of staged fuel nozzles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If staged fuel injection is used to reduce emissions and maintain stability at part power conditions, then engine performance is improved, but stagnant fuel in unused circuits becomes susceptible to coking
Solution Approach 1:
The patent extracts the cooling function from the fuel circuit by introducing a separate cooling circuit that runs parallel to the fuel circuit. This allows the fuel circuit to be staged on/off for performance optimization while the cooling circuit continuously prevents coking in stagnant fuel passages.
Solution Approach 2:
The cooling circuit serves multiple functions: it cools stagnant fuel in staged-off circuits, prevents coking formation, and can be integrated into the existing fuel system architecture without requiring separate dedicated cooling systems for each circuit.
2Duration of action of stationary object
If passive insulation or purging is used to protect fuel circuits from coking, then injector life is extended, but system complexity increases or additional components are required
Solution Approach 1:
The patent merges the cooling function with the existing fuel system architecture by integrating cooling circuits into the nozzle structure and using the fuel system's existing infrastructure (pump, manifolds, control systems) to distribute coolant, thereby extending injector life without proportionally increasing system complexity.
Solution Approach 2:
The system uses the fuel pump and existing fuel circulation infrastructure to also circulate coolant through the cooling circuits, allowing the fuel system to serve its own cooling needs without requiring entirely separate cooling infrastructure.
3Temperature
If active cooling using fuel flow from pilot fuel circuit is used, then stagnant fuel circuits are cooled, but heat capacity of cooling media limits effectiveness
Solution Approach 1:
The patent changes the cooling parameters by introducing a dedicated cooling circuit with controlled coolant flow rates and temperatures, allowing optimization of heat transfer efficiency beyond what is achievable with pilot fuel flow alone. The system can adjust coolant temperature and flow independently of fuel delivery requirements.
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 prevents coking in staged fuel nozzles, enhancing engine performance and reducing maintenance by actively cooling fuel circuits, even when the engine is inactive or at low power.
Implementation Method 1
The cooling circuit includes an inlet and an outlet. The inlet is in fluid communication with the cooling system for circulation of coolant through the cooling circuit and back to the cooling system out the outlet of the cooling circuit for cooling the fuel circuit with the fuel circuit staged off.
Data Source
AI summary
A fuel system includes a fuel supply system. A plurality of fuel nozzles are connected in fluid communication with the fuel supply system to supply fuel from a fuel source to be issued for combustion from the fuel nozzles. A cooling system is included, wherein at least one of the fuel nozzles includes a cooling circuit in addition to a fuel circuit for issuing fuel from the fuel supply system for combustion. The cooling circuit includes an inlet and an outlet. The inlet is in fluid communication with the cooling system for circulation of coolant through the cooling circuit and back to the cooling system out the outlet of the cooling circuit for cooling the fuel circuit with the fuel circuit staged off.