Dual-Fuel Manifold Purging With Inert Gas to Prevent Flashback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dual-fuel engine systems face challenges in preventing flashback and coking during engine startup and shutdown due to the accumulation of flammable fuel mixtures in the manifolds, particularly with volatile gases like hydrogen.
Innovation Solution
A dual-fuel system with a purge gas circuit and controller that uses inert gas to maintain pressure in the fuel circuits, preventing flashback by mixing inert gas with gaseous fuel and ensuring the fuel manifold remains pressurized during engine shutdown and startup, and a method to purge residual fuel to prevent coking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gaseous fuel is supplied to the combustor during engine startup and shutdown, then the engine can be operated, but flashback occurs due to accumulation of flammable fuel mixtures in the manifolds
Solution Approach 1:
The patent introduces an inert gas (such as nitrogen) into the gaseous fuel manifold during engine startup and shutdown operations. This inert gas displaces the flammable fuel-air mixture in the manifold, creating an inert atmosphere that prevents flashback while allowing the engine to be operated during these transition phases.
2Reliability
If gaseous fuel pressure is reduced before purging, then purging can be performed, but coking occurs in the fuel circuits
Solution Approach 1:
The patent performs purging with inert gas before reducing the gaseous fuel pressure. By clearing the fuel circuits of residual fuel while maintaining pressure, the system prevents coking from occurring during the subsequent pressure reduction and shutdown phases.
3Reliability
If purge gas is introduced to maintain pressure in the gaseous fuel manifold, then flashback is prevented, but the system complexity increases
Solution Approach 1:
The inert gas system is designed to serve multiple functions: it acts as a purge gas to clear flammable mixtures from the manifold, serves as a pressure maintenance gas during startup and shutdown, and provides an inert atmosphere to prevent flashback. This multi-functionality reduces the need for separate systems for each function.
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 flashback and coking by maintaining fuel manifold pressure and purging residual fuel, enhancing safety and reliability during engine operations.
Implementation Method 1
mixing inert gas with gaseous fuel and ensuring the fuel manifold remains pressurized
Implementation Method 2
uses inert gas to maintain pressure in the fuel circuits, preventing flashback
Implementation Method 3
purging residual fuel to prevent coking
Data Source
AI summary
A fuel system can include a first fuel circuit, a second fuel circuit, and an inert gas purge system operatively connected to both the first fuel circuit and the second fuel circuit to purge at least a portion of either or both of the first and/or second fuel circuit. The first fuel can be a liquid fuel and the second fuel can be a gaseous fuel. The first fuel circuit can include a first fuel manifold configured to fluidly communicate a first fuel supply with at least one dual fuel nozzles downstream of the first fuel manifold.