Virtual Variable Displacement Two-Stroke Engine
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Solution Overview
Problem
Conventional internal combustion engines rely on ambient air, which limits their efficiency and generates undesirable byproducts, necessitating the development of a more advanced technology that can utilize non-atmospheric oxidizers to enhance power and reduce pollution.
Innovation Solution
A two-stroke engine design with direct injection of fuel, oxidizer, and working fluid, utilizing cryogenic oxygen as the oxidizer, and a timing system to control the opening of exhaust valves, allowing for efficient power generation and reduced environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If ambient air is used as oxidizer and working fluid, then the engine can operate with simple intake system, but the thermodynamic efficiency is limited and nitrogen-oxygen compounds are generated in exhaust
Solution Approach 1:
The patent extracts nitrogen from the oxidizer mixture, using oxygen-enriched air or pure oxygen instead of ambient air. This removes the limiting factor (nitrogen) that caps combustion temperature and thermodynamic efficiency, allowing the engine to operate at higher efficiencies without generating harmful nitrogen-oxygen compounds
Solution Approach 2:
The patent changes the composition parameter of the oxidizer from ambient air (21% oxygen) to oxygen-enriched air or pure oxygen. This parameter change enables higher combustion temperatures and improved thermodynamic efficiency while eliminating the formation of undesirable nitrogen-oxygen compounds in the exhaust
2Device complexity
If ambient air is used as oxidizer, then the engine structure can be simplified, but exhaust catalysts are required to remove or change exhaust before venting
Solution Approach 1:
By extracting nitrogen from the oxidizer mixture and using oxygen-enriched air or pure oxygen, the patent eliminates the source of nitrogen-oxygen compounds in the exhaust. This removes the need for exhaust catalysts to treat harmful emissions, simplifying the overall engine system while reducing environmental impact
3Power
If large displacement engine is used to generate large power, then sufficient power can be produced, but engine size and weight increase
Solution Approach 1:
The patent implements a variable displacement system that dynamically adjusts the effective cylinder volume based on power demand. At low power requirements, the displacement is reduced by limiting the intake charge, while at high power demands, the full displacement is utilized. This allows the engine to maintain high specific power output while reducing overall size and weight compared to a conventional engine designed for maximum power
Solution Approach 2:
The patent changes the effective displacement parameter dynamically rather than maintaining a fixed large displacement. By adjusting the amount of intake charge and using oxygen-enriched combustion, the engine achieves high power output when needed while operating efficiently at lower power levels, reducing the required engine size and weight
4Quantity of substance
If mechanical methods are used to compress ambient air into cylinder, then sufficient oxygen can be provided for combustion, but mechanical force from engine must be used to compress the air
Solution Approach 1:
The patent extracts oxygen from ambient air through enrichment processes, providing a higher concentration of oxygen in the intake charge. This reduces the total volume of air that needs to be compressed and delivered to the cylinder, thereby reducing the work required for air compression while maintaining sufficient oxygen supply for combustion
Solution Approach 2:
The patent changes the oxygen concentration parameter in the intake charge from 21% in ambient air to a higher concentration through enrichment. This parameter change allows for reduced mass flow rates while maintaining the same oxygen supply, thereby reducing the energy required for compression and delivery of the charge to the cylinder
Data Source
AI summary
A true two-stroke (power and exhaust) internal combustion piston engine combining direct injection of all combustion and working fluid elements with exhaust valve(s) that open early during the power stroke if cylinder pressure falls below exhaust manifold pressure, will operate efficiently from power levels produced by conventional four-stroke engines of a fraction of the displacement of the two-stroke engine to power levels attainable by conventional four-stroke engines of twice the two-stroke engine displacement. No additional external systems will be required to enhance performance or control emissions, as all such enhancements are equivalent to control of the combustion and working fluid components. The magnitude of the combustion charge determines the power, and the makeup of the combustion components determine exhaust emissions. Any implementation of the true two-stroke engine will have the further advantages of requiring only half the cylinders (space and weight) and an equivalent reduction in required support systems. No intake valve train, no intake filter or manifolds, no catalytic converter or exhaust gas recirculation will be required. Some implementations may eliminate other support systems entirely (starter, cooling, exhaust valve train, etc.)