Gas Turbine Fuel Supply System Priming Control
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Solution Overview
Problem
The existing fuel supply systems for multi-stage combustors in gas turbine engines face challenges in controlling fuel dips and spikes during staging, leading to inefficient engine acceleration and deceleration, and increased fuel consumption due to uncertainty in fuel drainage and priming flows.
Innovation Solution
A fuel supply system with a metering and splitting arrangement, pressure sensor, and controller that provides closed-loop control of priming flows to refill the mains distribution pipework volume and manage pressure spikes, reducing fuel spikes and dips by optimizing priming flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a separate recirculation manifold is used to keep mains fuel cool during pilot-only operation, then thermal management is improved, but device complexity increases
Solution Approach 1:
The patent merges the cooling function into the existing mains fuel distribution system by using the distribution pipework volume itself as the cooling reservoir. The controller commands the mains fuel distribution pipework to supply cooling flow to the combustor during pilot-only operation, eliminating the need for a separate recirculation manifold while maintaining thermal management.
2Productivity
If open loop meter additional fuel to compensate for expected dip, then fuel consumption is increased, but acceleration performance is improved
Solution Approach 1:
The patent implements closed-loop control where the controller monitors engine operating conditions and commands the mains fuel distribution pipework to supply priming flow based on actual staging transitions. The system detects when mains stages are brought back into use and provides priming flow only when needed, rather than using open-loop compensation that continuously adds excess fuel.
3Reliability
If drained volumes are kept relatively small, then fuel spikes are reduced, but acceleration times are increased
Solution Approach 1:
The patent makes the priming flow dynamic and controllable through the controller that monitors engine operating conditions. The system can adjust the magnitude and duration of priming flow based on the specific staging transition requirements, allowing optimized acceleration profiles without excessive fuel spikes. This replaces the static approach of keeping drained volumes small with a dynamic control strategy.
Data Source
AI summary
A fuel supply system for fuel injectors of a multi-stage combustor of a gas turbine engine is provided. The system has a metering and splitting arrangement which receives a pressurised fuel flow and controllably meters and splits the received flow into metered pilot and mains flows for injecting respectively at pilot and mains fuel discharge orifices of the injectors to perform staging control of the combustor. The system further has pilot and mains fuel distribution pipeworks respectively distributing fuel from the metering and splitting arrangement to the pilot and mains discharge orifices. The system further has a controller which is configured to command the metering and splitting arrangement to provide the metered flows, to select the pilot distribution pipework and deselect the mains distribution pipework for pilot-only operation.