Oxygen-Injected Two-Stroke Engine Combustion
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Solution Overview
Problem
Internal combustion engines face inefficiencies due to air dilution, which leads to unwanted oxides of nitrogen and increased volumetric flow, impacting design and operation, and existing solutions do not adequately address these issues.
Innovation Solution
A power system using a source of concentrated oxygen, separated from air using an ionic transport membrane, is introduced, allowing for controlled burn rates and oxygen-fuel ratios through pulsed injection, with an oxygen reservoir and injector system, and a rotary valve for efficient combustion and scavenging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If air is used as the oxidizer source in internal combustion engines, then the system does not require carrying fuel oxidizer, but the oxidizer is diluted with nitrogen resulting in unwanted oxides of nitrogen and increased volumetric flow
Solution Approach 1:
The patent extracts only the beneficial component (oxygen) from air by using an oxygen separator that removes nitrogen and other non-reactive gases. This extraction eliminates the source of nitrogen oxides while maintaining the necessary oxidizer for combustion, directly resolving the contradiction between avoiding harmful emissions and managing volumetric flow.
Solution Approach 2:
The patent changes the concentration parameter of the oxidizer from ambient air (21% oxygen) to concentrated oxygen (greater than 21% oxygen, preferably greater than 50%). This parameter change reduces the volumetric flow required for effective combustion while eliminating nitrogen-containing harmful emissions.
2Productivity
If concentrated oxygen is used in the engine, then fuel economy and engine efficiency increase, but the system requires an oxygen separator and storage system
Solution Approach 1:
The oxygen separator is designed to perform multiple functions: separating oxygen from air, cooling the oxygen, and providing a concentrated oxygen source for the engine. This multi-functionality reduces the need for additional separate systems, thereby limiting the increase in device complexity while achieving improved fuel economy.
3Object-affected harmful factors
If oxygen is separated from air by cooling to liquid for injection, then nitrogen is removed from the combustion process, but the system requires complex cryogenic equipment
Solution Approach 1:
The patent uses a membrane-based oxygen separator that operates at or near ambient temperatures, replacing complex cryogenic equipment. The membrane separator is a simpler, more compact device that achieves nitrogen removal through selective permeation rather than phase change, significantly reducing device complexity while maintaining the benefit of nitrogen exclusion.
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 solution significantly reduces air pollution, increases fuel economy, and enhances engine efficiency by minimizing nonproductive air components and achieving higher oxygen purity, allowing for a two-stroke cycle with controlled combustion and scavenging.
Implementation Method 1
The separator separates oxygen from other constituents of air. Ionic transport membranes from one category of such devices which are applicable for mobile and stationary use with an engine.
Implementation Method 2
In a preferred embodiment the oxygen separator employs a ceramic fiber membrane doped with perovskits or fluorites in a closed case.
Data Source
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AI summary
A power system including a variable volume combustion chamber for a two- stroke engine having a controlled exhaust port, a fuel injector to the combustion chamber and an oxygen injector to the combustion chamber. The oxygen injector provides repeated oxygen injection pulses to complete a charge. The controlled exhaust port includes an oscillating rotatably mounted valve. A source of pressurized concentrated oxygen to the oxygen injector is in a closed case having a ceramic fiber membrane. An air inlet and a waste outlet are in communication with a first side of the ceramic fiber membrane. An oxygen outlet is in communication with a second side of the ceramic fiber Ionic transport membrane. The case has a heat transfer surface in communication with the controlled exhaust port from the combustion chamber.