Scissor-Type Compression Machine for Thermal Energy Recovery
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Solution Overview
Problem
Existing systems for transforming thermal energy into mechanical energy, such as those using Rankine, Brayton, and rotary vane machines, face inefficiencies due to high friction, complex architectures, and size constraints, particularly in vehicles where heat energy losses from engines need to be effectively harnessed.
Innovation Solution
A scissor-type compression and expansion machine with rotating pistons and a coordinated movement system that allows for high compression ratios and flow rates with reduced friction, utilizing an open cycle with air as the working fluid, and featuring distinct passage sections for gas inlet and outlet openings to optimize energy recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a turbine is used to transform thermal energy into mechanical energy, then high flow rates and efficiency are achieved, but the system becomes large and cumbersome requiring high rotation speeds (>100,000 rpm) and large cooling systems
Solution Approach 1:
The patent replaces the turbine's high-speed rotational mechanical system with a scissor-type mechanism operating at much lower speeds. The scissor mechanism transforms thermal expansion into mechanical work through a coordinated folding/unfolding motion, eliminating the need for high-speed rotation while maintaining effective energy transformation.
Solution Approach 2:
The invention changes the operating parameters from high rotation speeds (>100,000 rpm) to lower rotation speeds, and from continuous high-velocity flow to controlled volumetric expansion. This parameter transformation allows the system to achieve comparable productivity with significantly reduced size and simplified cooling requirements.
2Stress or pressure
If piston and crankshaft systems with camshafts and valves are used, then high compression ratios are achieved, but the system becomes complex and cumbersome
Solution Approach 1:
The patent segments the compression and expansion processes into distinct phases within the scissor mechanism's motion cycle. The scissor arms are divided into movable and fixed segments that coordinate to create compression and expansion chambers, eliminating the need for complex valve timing and camshaft mechanisms while maintaining high compression ratios.
Solution Approach 2:
Instead of using admission systems to force fluid into chambers, the invention inverts the approach by allowing fluid to naturally fill chambers during the expansion phase, then using the scissor mechanism's geometric constraints to achieve compression during the folding phase. This eliminates complex intake/exhaust valve systems.
3Productivity
If rotary vane machines are used, then high compression ratios and flow rates are achieved with low rotation speeds, but friction losses increase due to dry friction between vanes and chamber walls
Solution Approach 1:
The patent extracts the friction problem by eliminating direct contact between moving parts and chamber walls. The scissor mechanism uses pinned joints and hinges that rotate on well-lubricated bearings, separating the compression function from the friction-prone sliding contact found in vane machines. The chamber walls only contain fluid, not support moving vanes.
Solution Approach 2:
The invention uses the working fluid itself as the medium to transmit force and perform work, rather than relying on mechanical contact between solid vanes and walls. The fluid pressure drives the scissor mechanism's motion, converting thermal energy directly into mechanical work with minimal friction losses.
4Ease of manufacture
If passage sections for gas inlet and outlet are equal, then system simplicity is maintained, but energy recovery efficiency is reduced
Solution Approach 1:
The patent applies different passage section sizes at different locations in the system. The gas inlet passage has a larger cross-sectional area to facilitate high-speed fluid entry during compression, while the outlet passage is optimized for exhaust flow during expansion. This local differentiation optimizes energy recovery without significantly complicating the overall system design.
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 design achieves significant pressure gains at lower rotation speeds, reduces friction losses, and enhances integration and efficiency in vehicles by minimizing size and weight, while maintaining high flow rates and reducing pressure drops, thus improving overall energy recovery from heat sources like engine exhaust gases.
Implementation Method 1
a first compression/expansion cycle corresponding to a step of compressing a first flow of gas passing through this cell and at least one second compression/expansion cycle corresponding to a step of expansion of a second flow of gas passing through this cell
Implementation Method 2
the fluid performs a cycle during which it must be pumped or compressed to enter a heat exchanger before it can then supply mechanical energy through an expansion
Data Source
Figure 1~2
Figure 3~5
AI summary
The invention relates to a compression and expansion machine comprising a body (12a) with at least one chamber (12) of revolution about an axis of symmetry and rotary pistons (14a, 14b, 14c, 14d) rotating about the axis of symmetry and dividing the chamber into rotary cells (15a, 15b, 15c, 15d) rotating with the pistons, said machine further comprising a coordination device (22) for coordinating the movement of said pistons and configured so that, during one revolution, each cell (15a, 15b, 15c, 15d) performs at least one first expansion/contraction cycle corresponding to a stage of compressing a first stream of gas passing through this cell and at least one second expansion/contraction cycle corresponding to a stage of expanding a second stream of gas passing through this cell.