Hydrogen ICE Pilot Injection Using EGR Water-Diesel Emulsion
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Solution Overview
Problem
Hydrogen ICE systems face challenges in achieving stable ignition and efficient fuel metering, particularly at lower engine loads, leading to increased diesel consumption and emissions, which complicates control and affects reliability and efficiency.
Innovation Solution
A system is introduced to extract water condensate from the exhaust gas recirculation system, utilizing it to create a diesel-water emulsion for pilot injection, reducing diesel volume and enhancing emission control strategies by integrating a water condensate extraction system and diesel-water emulsion blender.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If micro pilot diesel injection is used to achieve stable hydrogen ignition, then ignition stability is improved, but diesel consumption increases and emissions worsen
Solution Approach 1:
The patent changes the chemical composition parameter of the pilot fuel from pure diesel to a diesel-water emulsion. This emulsion contains water droplets dispersed in diesel, which modifies the combustion characteristics. The water content (typically 10-50% by volume) alters the ignition properties, allowing reduced diesel quantity while maintaining ignition stability for hydrogen combustion.
Solution Approach 2:
The patent uses a composite fuel mixture - a diesel-water emulsion - as the pilot fuel. This emulsion is created by mixing diesel with water and adding emulsifiers to stabilize the mixture. The composite nature of this fuel allows it to provide both the ignition properties of diesel and the emission-reducing effects of water, resolving the contradiction between ignition stability and diesel consumption.
2Object-generated harmful factors
If higher EGR levels are used to reduce engine-out NOx, then NOx emissions are reduced, but water concentration in exhaust gases increases requiring management
Solution Approach 1:
The patent converts the harmful effect of high EGR (which produces excessive water vapor that could condense and cause problems) into a beneficial resource. The water vapor in the exhaust is condensed and collected, then reused as part of the diesel-water emulsion for pilot injection. This transforms a potential harm (water management issue) into a benefit (reduced diesel consumption and further NOx reduction).
Solution Approach 2:
The system uses its own exhaust gas water vapor to create the emulsion fuel, rather than requiring external water sources. The condensed water from the exhaust is fed back into the emulsion preparation system, creating a self-sustaining cycle where the engine's own byproduct serves the fuel preparation need.
3Object-generated harmful factors
If diesel volume in pilot injection is reduced to lower emissions, then emission control is improved, but ignition stability may be compromised
Solution Approach 1:
The patent changes the physical and chemical parameters of the pilot fuel by introducing water in emulsion form. This emulsion modifies the combustion process - the water evaporates during combustion, absorbing heat and lowering combustion temperatures, which reduces NOx formation while the diesel component maintains ignition capability. This allows reduced diesel volume while preserving ignition stability.
Solution Approach 2:
The water in the emulsion acts as an intermediary substance that mediates between the need for low diesel emissions and the need for ignition stability. The water droplets are dispersed throughout the diesel, creating a two-phase fuel that provides both the ignition properties of diesel and the emission-reducing effects of water during combustion.
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 reduces diesel consumption and emissions, particularly under lower load conditions, improving fuel metering precision and reliability while aligning with environmental targets by lowering NOx and CO2 production.
Implementation Method 1
a water condensate extraction system configured to be in fluid communication with the EGR system and further configured to extract water condensate from the exhaust gases circulating in the EGR conduit
Implementation Method 2
a diesel-water emulsion blender and storage system configured to receive the extracted condensed water and further configured to create a diesel-water emulsion from the extracted condensed water and diesel
Implementation Method 3
the water condensate extraction system comprises a cooler for cooling exhaust gases passing through the EGR system
Data Source
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AI summary
The present disclosure relates to an internal combustion engine (ICE) system (2) operating on a hydrogen-based fuel, comprising: an ICE (10) having at least one cylinder (11) at least partly defining a combustion chamber (13); a fuel injector arrangement (72) configured to inject a pilot diesel fuel portion and a main hydrogen-based fuel portion into the combustion chamber; an exhaust gas recirculation (EGR) system (30) having an EGR conduit (32) arranged to connect an exhaust manifold (14) and an air intake manifold (12) to permit recirculation of exhaust gas through the at least one cylinder during operation of the ICE; a water condensate extraction system (50) configured to be in fluid communication with the EGR system and further configured to extract water condensate from the exhaust gases circulating in the EGR conduit; and a diesel-water emulsion blender and storage system (60) configured to receive the extracted condensed water and further configured to create a diesel-water emulsion from the extracted condensed water and diesel.