Sonic Gas Inlet Valve for High Lambda Combustion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current technologies face challenges in achieving efficient mixing and combustion in natural gas engines, particularly in uniflow 2-stroke engines with high Lambda values, leading to increased NOx emissions and reduced thermal efficiency, and in implementing continuous water injection due to weight, volume, and corrosion issues, as well as prechamber deactivation causing combustion instability.
Innovation Solution
A sonic and dual-stage gas inlet valve design with a narrower valve head and seat angle, direct water injection into the natural gas inlet valve, and an advanced prechamber fuel pressure control module to manage cylinder deactivation and mixing, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a larger prechamber is used to operate at very high Lambda values, then the engine can operate at high air/fuel ratios, but NOx emissions increase and thermal efficiency decreases
Solution Approach 1:
The patent changes the geometric parameters of the prechamber, specifically using a smaller prechamber volume with optimized dimensions. This parameter change allows the engine to operate at very high Lambda values (above 3 at low load, exceeding 4 at idle) while maintaining lower NOx emissions and higher thermal efficiency compared to larger prechamber designs.
2Adaptability or versatility
If inlet air box pressure is reduced to enable throttling at low loads, then smaller prechambers can be used, but mixing energy is lost and scavenging effectiveness decreases
Solution Approach 1:
The patent employs a sonic gas inlet valve that utilizes high-frequency oscillations to enhance mixing of air and natural gas at very high Lambda values. This vibration-based mixing mechanism compensates for the loss of mixing energy from reduced inlet air box pressure, maintaining effective combustion even when throttled at low loads.
Solution Approach 2:
The sonic gas inlet valve creates intense localized mixing and combustion conditions through high-frequency oscillations, accelerating the oxidation process. This allows complete combustion of natural gas even at very high air/fuel ratios where conventional mixing would be insufficient.
3Use of energy by moving object
If continuous water injection is implemented to improve combustion, then thermal efficiency increases, but system weight, volume, and corrosion issues increase
Solution Approach 1:
The patent extracts the water injection function from a continuous, heavy-duty system and implements it as an intermittent, on-demand system. Water injection is activated only during specific combustion events (every other cycle or during high load conditions), eliminating the need for continuous water flow infrastructure, reducing system weight and volume, and minimizing corrosion exposure.
Solution Approach 2:
The water injection system operates periodically rather than continuously, injecting water at strategically selected combustion cycles. This periodic operation achieves the desired thermal efficiency improvements while dramatically reducing the required water storage capacity, system weight, and corrosion-related maintenance.
4Object-generated harmful factors
If prechamber deactivation is used to reduce emissions, then NOx emissions decrease, but combustion stability deteriorates
Solution Approach 1:
The patent implements a feedback control system that monitors combustion conditions and dynamically adjusts prechamber fuel pressure and water injection timing. This feedback mechanism maintains optimal combustion stability even when prechambers are deactivated or operated at very high Lambda values, preventing misfires and ensuring consistent performance.
Solution Approach 2:
The advanced prechamber fuel pressure control module dynamically changes fuel pressure parameters based on operating conditions, maintaining stable combustion during prechamber deactivation events. This parameter adjustment ensures that when prechambers are active, they operate at optimal conditions, compensating for the instability introduced by periodic deactivation.
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 solutions enhance mixing efficiency, reduce NOx emissions, maintain thermal efficiency, and simplify water injection systems, while ensuring stable combustion and extended valve life, thereby improving engine performance and reducing emissions.
Implementation Method 1
a sonic and dual stage gas inlet valve design with a narrower valve head and seat angle to accelerate the incoming natural gas flow
Implementation Method 2
direct water injection into the natural gas inlet valve
Implementation Method 3
enhance mixing efficiency, reduce NOx emissions, maintain thermal efficiency
Implementation Method 4
an advanced prechamber fuel pressure control module to manage cylinder deactivation and mixing
Implementation Method 5
all the gas was converged into one flow stream that now had higher velocity and was pointed away from the prechamber
Data Source
AI summary
A gas injection valve includes a poppet valve extending from a valve body having a valve seat, a plunger moveable within a plunger body, a plunger stop axially moveable within a plunger stop enclosure formed within a plunger stop body secured within the valve body adjacent to the plunger body, a plunger follower secured to and extending through the plunger stop and in contact with the poppet valve, and a port for receiving hydraulic fluid extending through the valve body into the plunger stop body enclosure. The plunger stop is moveable between a first position and a second position. The gas injection valve has a first stroke length when the plunger stop is in the first position and a second stroke length when the plunger stop is in the second position.