Fuel Manifold Bias Control for Gaseous Fuel Leakage Compensation
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Solution Overview
Problem
Existing engine systems struggle to manage fuel demand changes effectively due to the compressibility of gaseous fuels, leading to fuel leakage from the manifold into the combustor, which affects the accuracy of fuel delivery.
Innovation Solution
A controller is used to apply a fuel loss bias to account for the compressibility of gaseous fuel, adjusting the fuel flow request to compensate for leakage, using mass flow or pressure measurements to determine the necessary correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fuel manifold pressure is reduced to match combustor pressure (eliminating pressure differential), then fuel leakage from manifold to combustor is prevented, but fuel flow response to load changes becomes sluggish and inefficient
Solution Approach 1:
The system performs preliminary action by pre-positioning fuel in the manifold at elevated pressure before combustion events. This stored pressurized fuel is then rapidly delivered to the combustor when needed, enabling both quick response to load changes and controlled pressure management to prevent leakage.
Solution Approach 2:
The fuel manifold system dynamically adjusts pressure based on operating conditions. The pressure differential is maintained during normal operation for rapid response, then actively managed during transitions to prevent leakage. This dynamic pressure control allows the system to optimize between response speed and leakage prevention in different operational states.
2Productivity
If a large pressure differential is maintained between fuel manifold and combustor for rapid fuel delivery, then fuel flow response to load changes improves, but fuel leakage from manifold to combustor increases
Solution Approach 1:
The control system continuously monitors fuel manifold pressure and combustor conditions, then adjusts the fuel delivery rate accordingly. This feedback mechanism allows the system to maintain the pressure differential needed for rapid response while preventing excessive pressure that would cause leakage, optimizing both productivity and substance conservation.
Solution Approach 2:
The system changes the pressure parameter dynamically based on operational needs. During rapid load changes, higher pressure differential is applied for quick fuel delivery. During steady-state operation, pressure is reduced to minimize leakage. This parameter adjustment resolves the contradiction between response speed and leakage prevention.
3Speed
If fuel is stored in manifold at high pressure for quick response to load changes, then fuel delivery speed improves, but the risk of uncontrolled fuel transfer to combustor increases
Solution Approach 1:
The fuel delivery system incorporates controlled intermediary elements (such as pressure-regulated valves or flow control mechanisms) between the high-pressure manifold and the combustor. These intermediaries allow rapid fuel delivery when needed while preventing uncontrolled fuel transfer, mediating between the high-pressure storage and the combustion chamber.
Data Source
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AI summary
There are describes methods and systems for operating an engine coupled to a fuel system (120) having a fuel manifold (200) configured to supply fuel to a combustor (16) of the engine (100). The method comprises receiving a gaseous fuel flow request indicative of a change in demand for gaseous fuel to the engine; applying a fuel loss bias to the gaseous fuel flow request to obtain a biased fuel flow request, the fuel loss bias associated with a change in mass flow rate of the gaseous fuel from the fuel manifold (200) to the combustor (16) in response to the change in demand; and causing the gaseous fuel to flow into the combustor (16) in accordance with the biased fuel flow request.