Two-Stroke Engine Port Layout and Positive Displacement Intake
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Solution Overview
Problem
Existing internal combustion engine systems face challenges in reducing backfiring and knock/self-ignition, particularly when operating on hydrogen fuel, due to the complexity and cost of adapting conventional diesel engines.
Innovation Solution
A spark-ignition internal combustion engine system with a two-stroke configuration, featuring a pair of cylinders with intake and exhaust ports positioned differently to prevent pressure pulses from transferring back into the induction system, and utilizing a positive displacement device in the air intake duct to control airflow and reduce backfiring risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional diesel engines are adapted to use hydrogen fuel, then the engine can operate on fossil-free fuel, but the adaptation becomes complex and costly
Solution Approach 1:
The engine system is divided into separate functional components: a dedicated two-stroke engine design with distinct intake/exhaust port arrangements, positive displacement device for air charging, and fuel injection system. This segmentation allows the engine to be optimized for hydrogen operation without requiring complex modifications to conventional four-stroke diesel architecture.
Solution Approach 2:
Instead of adapting four-stroke diesel engines to run on hydrogen, the patent inverts the approach by designing a dedicated two-stroke engine from the ground up for hydrogen operation. This reverse engineering approach eliminates the need for complex adaptations of existing diesel engines while achieving the goal of fossil-free fuel operation.
2Volume of moving object
If intake and exhaust ports are positioned close together in two-stroke engines, then the engine structure is compact, but pressure pulses can transfer back into the induction system causing backfiring
Solution Approach 1:
A positive displacement device is introduced as an intermediary component between the atmosphere and the cylinder intake port. This device charges the intake port with air during the intake stroke and prevents pressure pulse transfer back into the induction system during exhaust, thereby eliminating backfiring while maintaining compact engine design.
Solution Approach 2:
The positive displacement device dynamically adjusts its operation based on the engine cycle phase, providing air charging during intake and preventing pressure pulse backflow during exhaust. This dynamic behavior allows the engine to maintain compact port positioning while preventing backfiring through active pressure management.
3Object-generated harmful factors
If the engine operates on hydrogen fuel, then emissions are reduced, but the risk of knock and self-ignition increases
Solution Approach 1:
The positive displacement device performs preliminary action by charging the intake port with pressurized air before the combustion event. This pre-charging ensures proper air-fuel mixing and controlled combustion timing, preventing premature self-ignition and knock while maintaining the emission benefits of hydrogen fuel operation.
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 proposed engine system effectively reduces the risk of backfiring and knock/self-ignition, allowing for increased control over combustion chamber temperature and reduced time to ignition, while maintaining efficiency and power density.
Implementation Method 1
an air intake duct (22) comprising a positive displacement device (23) configured to receive and feed intake air to the at least one pair of cylinders
Implementation Method 2
The ICE has at least a pair of first and second cylinders (30, 40) with corresponding first and second cylinder walls (30a, 40a)... an ignition source (34, 44) arranged in the first combustion chamber
Data Source
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AI summary
The present disclosure relates to a spark-ignition internal combustion engine, ICE, system (10) for a vehicle, comprising a two-stroke ICE, (20) a first cylinder accommodating a reciprocating first piston (31) operable between a bottom dead center and a top dead center, and further at least partly defining a first combustion chamber (32) with a top end (33) of the first piston, at least one intake port (35) arranged at a top end (36) of the first cylinder and in fluid communication with the combustion chamber, and further an exhaust port (38) arranged distal from the top end of the first cylinder, a second cylinder accommodating a reciprocating second piston (41) operable between a bottom dead center and a top dead center, and further at least partly defining a second combustion chamber (42) with a top end (43) of the second piston, at least one corresponding intake port (45) arranged at a top end (46) of the second cylinder and in fluid communication with the second combustion chamber, and further a corresponding exhaust port (48) arranged distal from the top end of the second cylinder, wherein the pair of first and second cylinders are arranged separated from each other with a crank angle of 180 degrees.