Flexible Bladder Energy Cell for Thermal-Mechanical Conversion
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Solution Overview
Problem
Existing solutions for thermal energy conversion to mechanical energy lack optimal thermal efficiency, structural strength, power density, manufacturing efficiency, and manufacturing costs.
Innovation Solution
An energy cell design that includes a housing for phase change material (PCM) with insulating and heat exchanging components, featuring pipes with disc apertures and a flexible bladder for hydraulic fluid flow, optimized for high thermal efficiency and structural strength, and capable of minimizing thermal and mechanical losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid container structure is used to hold PCM and hydraulic fluid, then structural strength is improved, but thermal efficiency deteriorates due to thermal mass and heat transfer resistance
Solution Approach 1:
The patent employs a flexible bladder instead of a rigid container to hold the hydraulic fluid. This flexible membrane structure minimizes thermal mass and thermal resistance, allowing efficient heat transfer from the PCM to the hydraulic fluid while maintaining structural integrity. The bladder expands and contracts with pressure changes without requiring a heavy rigid framework.
Solution Approach 2:
The system uses hydraulic pressure generated by PCM expansion during phase change to directly drive the piston and connected mechanical components. This hydraulic mechanism efficiently transmits force without requiring additional rigid structural elements, reducing thermal mass while maintaining strength where needed.
2Loss of energy
If thermal insulation is added between housing and PCM, then thermal efficiency is improved, but device complexity increases
Solution Approach 1:
The patent applies thermal insulation selectively only at the outer housing interface with the environment, not between all components. The insulation layer is positioned specifically where thermal loss to the environment occurs, maintaining thermal efficiency while avoiding unnecessary complexity in the internal PCM-hydraulic fluid heat transfer path.
3Power
If phase change material is allowed to expand freely, then power density is improved, but structural strength deteriorates due to pressure stresses
Solution Approach 1:
The flexible bladder containing the hydraulic fluid accommodates the expanding PCM during phase change by deforming elastically. This allows the PCM to expand freely to generate high pressure and power density while the bladder contains the pressure stresses without requiring a heavy rigid structure. The bladder's flexibility enables it to withstand repeated expansion and contraction cycles.
4Loss of energy
If heat exchanger pipes are placed directly in contact with PCM, then thermal efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent uses the hydraulic fluid in the bladder as an intermediary medium between the PCM and the external heat exchanger system. The hydraulic fluid is in direct contact with the PCM, ensuring excellent thermal coupling, while the bladder wall provides a flexible barrier that is easier to manufacture with lower precision requirements compared to rigid pipe connections.
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 energy cell achieves high thermal efficiency, structural strength, and optimized power density, manufacturing efficiency, and reduced costs, enabling efficient conversion of thermal energy to mechanical energy.
Implementation Method 1
when a phase change material (PCM) changes from solid phase to liquid phase
Implementation Method 2
an insulating means arranged between the housing means and the phase change material (PCM)
Implementation Method 3
a heat exchanging means encompassed by the phase change material (PCM) and comprising a number of pipe means
Implementation Method 4
a centrally located, flexible bladder means which at its end parts are fixed to the energy cell and are open, and between the end parts being flexible
Data Source
AI summary
An energy cell generates pressurized fluid for use as an energy source when a phase change material (PCM) changes from solid to liquid phase. The energy cell includes housing means holding the PCM, insulating means between the housing means and the PCM, heat exchanging means encompassed by the PCM, multiple pipe means, and multiple disc means, each provided with multiple aperture means and each encompassing a part of the pipe, and a centrally located bladder means with open end parts fixed to the energy cell, and which is flexible between the end parts. Each pipe means includes a heat transfer media. The PCM encompasses the pipe means and the disc means and is able to pass through the aperture means. The bladder means includes a hydraulic fluid flowing in and out through the open end parts of the bladder means and is affected by the PCM.