Split-Cycle Air Hybrid Engine Multi-Mode Operation
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Solution Overview
Problem
Prior art air hybrid engines face complexity and cost issues due to the need for a complex valve and drivetrain system to switch between compression-braking, air motoring, and internal combustion engine modes, limiting their capability to operate in parallel and making them impractical for stationary applications.
Innovation Solution
A split-cycle engine design with dedicated compression and power pistons allows for simultaneous operation in internal combustion engine, air compressor, and pre-compressed air power modes, using an air reservoir and simplified control mechanisms to manage gas flow between cylinders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional four stroke cycle engine is adapted to perform compression, combustion and motoring functions in a single cylinder, then the engine can operate in multiple modes (ICE, CB, AM), but the valve and drivetrain system becomes complex and costly
Solution Approach 1:
The engine is divided into two separate cylinders: a compression cylinder dedicated to compression-braking functions and a power cylinder dedicated to power generation functions. This segmentation allows each cylinder to be optimized for its specific function, eliminating the need for complex valve and drivetrain switching mechanisms while maintaining multi-mode operation capability.
2Productivity
If a single cylinder performs all functions sequentially, then the engine structure remains simple, but the modes cannot operate in parallel and charging the air reservoir is limited
Solution Approach 1:
By separating the compression and power functions into different cylinders, the system enables parallel operation of multiple modes simultaneously. The compression cylinder can charge the air reservoir while the power cylinder generates power, increasing overall productivity without requiring complex sequential switching mechanisms.
3Ease of manufacture
If the compression piston and power piston share the same cylinder, then the engine design is simpler, but the tolerances and materials required to withstand combustion heat compromise compressor mode efficiency
Solution Approach 1:
The compression cylinder is designed separately from the power cylinder, allowing the compression cylinder to be optimized for compression efficiency with appropriate tolerances and materials, while the power cylinder handles combustion functions. This segmentation resolves the conflict between design simplicity and compressor mode efficiency.
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
Enables efficient operation in multiple modes simultaneously, enhancing capabilities and making the system applicable to both moving and stationary applications by optimizing cylinder functions and reducing the complexity of the valve/drivetrain system.
Implementation Method 1
the compression piston (26) draws in and compresses air which is stored in the reservoir (36) for later use
Implementation Method 2
the power piston (24) receives compressed air from the reservoir (36) which is expanded on the expansion stroke of the power piston (24), transmitting power to the crankshaft (18)
Implementation Method 3
compressed air is admitted to the power cylinder (14) with fuel, which is ignited, burned and expanded
Data Source
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AI summary
A split-cycle air hybrid engine operatively connects an air reservoir to a split cycle engine. A power piston is received within a power cylinder and operatively connected to a crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single revolution of the crankshaft. A compression piston is received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke in a single rotation of the crankshaft. The compression cylinder is selectively controllable to place the compression piston in a compression mode or an idle mode. An air reservoir is operatively connected between the compression cylinder and the power cylinder and selectively operable to receive compressed air from the compression cylinder and to deliver compressed air to the power cylinder for use in transmitting power to the crankshaft during engine operation.