Gaseous Fuel Manifold Air-Tightness Evaluation
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Solution Overview
Problem
Dual fuel internal combustion engines face issues with contamination and wear of gaseous fuel admission valves (GAVs) due to their proximity to the combustion chamber, leading to potential leakage and improper closure during switching between liquid fuel mode and gaseous fuel mode, which can result in severe engine damage.
Innovation Solution
A method is introduced to evaluate the air-tightness of the gaseous fuel manifold by flushing and pressurizing it with a purge gas, measuring pressure data, and aborting the initialization process if insufficient air-tightness is detected, ensuring proper operation of GAVs before switching to gaseous fuel mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gaseous fuel admission valves are positioned close to the combustion chamber for efficient fuel delivery, then fuel supply efficiency is improved, but the valves become susceptible to contamination and wear from combustion byproducts
Solution Approach 1:
The system performs a preliminary check of the gaseous fuel admission valves by attempting to open them and detecting any leakage paths before actual gaseous fuel injection begins. This preliminary action identifies contaminated or worn valves that cannot be properly closed, preventing them from receiving gaseous fuel and thus avoiding engine damage while maintaining efficient operation of healthy valves
2Ease of operation
If gaseous fuel admission valves are exposed to pressure differences during liquid fuel operation, then valve actuation is simplified, but particulates can enter the gaseous fuel piping and contaminate the valves
Solution Approach 1:
The system performs a preliminary operability check by attempting to open the gaseous fuel admission valves during liquid fuel operation and detecting any leakage. This preliminary action identifies valves that have opened due to pressure differences and may have allowed particulate contamination, allowing the system to prevent gaseous fuel injection through contaminated valves while maintaining simplified actuation operation
3Device complexity
If worn or contaminated gaseous fuel admission valves are used, then device complexity is reduced, but leakage occurs leading to sudden overfilling of cylinders and potential engine damage
Solution Approach 1:
The system implements a feedback mechanism by monitoring the operability of gaseous fuel admission valves through leakage detection. When a valve is found to be leaking or improperly closed, the system receives feedback and prevents gaseous fuel injection through that valve, avoiding sudden overfilling of cylinders and potential engine damage while maintaining simple valve structure without complex active control mechanisms
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
This approach prevents sudden overfilling of cylinders with gaseous fuel, reducing the risk of engine damage by ensuring the operability of GAVs before enabling gaseous fuel supply, thereby maintaining engine integrity and performance.
Implementation Method 1
flushing and/or pressurizing the gaseous fuel manifold with a purge gas at a pressure above an intake manifold air pressure thereby setting a differential gas pressure across gaseous fuel admission valves
Implementation Method 2
measuring a pressure associated with the flushing and/or the pressurizing, thereby generating pressure data
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
For a dual fuel internal combustion engine (100) with a plurality of cylinders (9) and at least one gaseous fuel admission valve (58) for each cylinder (9) of the plurality of cylinders (9) fluidly delimiting a gaseous fuel manifold (54) with respect to the respective cylinder (9), a method of evaluating air-tightness of the gaseous fuel manifold (54) comprises flushing (step 314) and/or pressurizing (step 316) the gaseous fuel manifold (54) with a purge gas at a pressure above an intake manifold air pressure thereby setting a differential gas pressure across gaseous fuel admission valves (58); measuring (step 320) a pressure associated with the flushing (step 314) and/or the pressurizing (step 316), thereby generating pressure data; and evaluating (step 322) the air-tightness of a gaseous fuel manifold (54) based on the measured pressure data.