Fuel Ejector Assembly for Engine EGR Flow
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Solution Overview
Problem
Internal combustion engines face challenges in efficiently recirculating exhaust gases due to the negative pressure required to draw these gases back into the engine, which increases fuel consumption and reduces engine efficiency.
Innovation Solution
A fuel ejector assembly that incorporates a nozzle to accelerate pressurized fuel, which then mixes with recirculated exhaust gas in a mixing portion, reducing the backpressure needed to draw the exhaust gas into the engine. This assembly includes a diffuser to communicate the fuel-exhaust gas mixture to the engine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the engine draws recirculated exhaust gas using negative pressure, then the EGR flow is achieved, but the fuel consumption increases and engine efficiency decreases
Solution Approach 1:
The patent uses a fuel ejector assembly that utilizes pressurized fuel flow through a nozzle to create a low-pressure region that draws recirculated exhaust gas into the engine. This pneumatic/hydraulic approach replaces the traditional negative pressure suction method with a positive pressure-driven flow system, reducing the energy penalty associated with creating and maintaining negative pressure in the EGR system.
Solution Approach 2:
The patent introduces pressurized fuel as an intermediary substance that mediates the EGR flow process. The fuel serves dual purposes: it is both the working fluid that drives the ejector and the substance being delivered to the engine. The fuel's pressure and velocity act as the driving force that entrains and transports the exhaust gas, eliminating the need for separate suction mechanisms.
2Productivity
If the engine exerts backpressure to draw recirculated exhaust gas, then the EGR flow is maintained, but the engine efficiency is reduced
Solution Approach 1:
The patent inverts the traditional EGR approach by instead of using the engine's negative pressure to suck in exhaust gas, it uses pressurized fuel to push and entrain the exhaust gas into the engine. This inversion transforms the EGR system from a passive suction-based system to an active pressure-driven system, reducing the burden on the engine's own pressure differential.
3Loss of energy
If pressurized fuel is used to propel recirculated exhaust gas, then the backpressure is reduced, but the system complexity increases
Solution Approach 1:
The patent combines the fuel delivery system and the EGR system into a single integrated fuel ejector assembly. The nozzle, mixing portion, and diffuser are merged into one component that simultaneously handles fuel injection and exhaust gas recirculation. This merging reduces overall system complexity by eliminating separate control mechanisms for EGR flow while maintaining precise control through the fuel delivery system.
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 solution reduces the negative pressure required by the engine to draw recirculated exhaust gas, thereby increasing engine efficiency and fuel economy, while also providing independent control of EGR flow and preventing water condensation within the fuel ejector assembly.
Implementation Method 1
a nozzle that receives pressurized fuel flow and accelerates the fuel flow into a mixing portion
Implementation Method 2
The excess energy ('exergy') of the pressurized fuel propels the recirculated exhaust gas into an engine
Implementation Method 3
A diffuser is disposed downstream of the mixing portion and is structured to be fluidly coupled to an engine to communicate a mixture of the fuel and the recirculated exhaust gas to the engine
Data Source
AI summary
A fuel ejector assembly includes a nozzle structured to receive fuel from a fuel conduit and eject the fuel therethrough, and an exhaust gas recirculation (“EGR”) conduit structured to communicate a recirculated exhaust gas therethrough. A mixing portion is disposed downstream of the nozzle and the EGR conduit, the nozzle and the EGR conduit fluidly coupled to the mixing portion such that the mixing portion receives each of the fuel and the recirculated exhaust gas. A diffuser is disposed downstream of the mixing portion and is configured to be fluidly coupled to an engine to communicate a mixture of the fuel and the recirculated exhaust gas to the engine.