Liquid Methane Tank Structure for Low-Pressure Cryogenic Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid methane storage systems face challenges such as high pressure requirements, cylindrical shape constraints, limited hold times, and inefficiencies in energy density due to heat ingress and pressure build-up, which affect vehicle range and power generation capacity.
Innovation Solution
A low-pressure storage tank design with a rope suspension system and non-cylindrical shape, combined with a dual-compressor system and heat management, allows for extended hold times and efficient conversion to gaseous methane flow, using materials like Kevlar® for reduced heat conductivity and flexibility in tank design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If liquid methane is stored in above-ground tanks, then infrastructure cost and complexity are reduced, but the fuel must be kept at extremely low temperatures (around -162°C) to remain liquid
Solution Approach 1:
The patent implements nested insulation structures where multiple insulation layers are placed concentrically around the fuel storage bladder. The bladder is nested within the first insulation layer, which is nested within the second insulation layer, creating a multi-layered thermal barrier that maintains extremely low temperatures without complex external infrastructure.
Solution Approach 2:
The patent introduces a vacuum environment between insulation layers to create a thermally inert barrier. The vacuum layer eliminates conductive and convective heat transfer, providing passive thermal isolation that maintains cryogenic temperatures without requiring active cooling infrastructure.
2Volume of moving object
If the storage system is made smaller to fit in a garage, then space requirements are reduced, but maintaining extremely low temperatures becomes more difficult
Solution Approach 1:
The patent uses nested insulation layers where each layer is contained within the previous one, maximizing insulation efficiency within a compact volume. The concentric arrangement ensures optimal thermal protection while minimizing the overall footprint of the storage system.
Solution Approach 2:
The patent employs flexible bladder materials that can be collapsed when empty and expanded when filled, allowing the storage system to adapt to small spaces. The thin-film insulation layers provide adequate thermal protection without adding significant volume.
3Ease of manufacture
If conventional above-ground storage tanks are used, then installation is simpler, but heat transfer from the environment causes fuel to boil off and requires periodic refilling
Solution Approach 1:
The patent implements nested insulation structures that provide superior thermal isolation compared to conventional single-layer systems. The multiple nested layers create cumulative thermal resistance, dramatically reducing heat ingress and fuel boil-off while maintaining a relatively simple monolithic tank design.
Solution Approach 2:
The patent uses vacuum insulation to create a thermally inert environment between the fuel bladder and external surroundings. This eliminates heat transfer through conduction and convection, minimizing fuel boil-off without requiring complex active cooling systems or periodic refilling.
4Loss of substance
If insulation layers are added to reduce heat transfer, then fuel loss from boil-off is reduced, but the system becomes more complex and harder to install
Solution Approach 1:
The patent integrates multiple insulation layers in a nested configuration that simplifies installation compared to separate layered systems. Each insulation layer is self-contained and fits within the previous layer, creating a unified structure that reduces assembly complexity while maintaining superior thermal performance.
Solution Approach 2:
The patent combines multiple insulation functions into integrated layers that serve both thermal isolation and structural purposes. The insulation layers are merged with the tank wall structure, eliminating the need for separate insulation components and simplifying the overall system.
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 system extends non-venting periods to 25-50 days, increases energy density by 30%, and enables flexible tank shapes, improving vehicle range and power generation capacity while minimizing environmental impact.
Implementation Method 1
The storage tank includes a bladder defined by a flexible membrane and a first vacuum insulation layer surrounding the bladder and a second vacuum insulation layer surrounding the first vacuum insulation layer
Implementation Method 2
The storage tank includes a bladder defined by a flexible membrane and a first reflective insulation layer surrounding the bladder and a second reflective insulation layer surrounding the first reflective insulation layer
Implementation Method 3
Vaporization cooling sensors positioned within the fuel delivery system detect a vaporization cooling effect associated with the liquid methane
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
Systems and methods for the storage and delivery of fuel, such as methane. In certain aspects, a system is provided with an inner vessel, and outer vessel, and a rope suspension system connecting the two vessels. In certain aspects, the disclosed storage tanks operate at low pressure with long hold times, and have a non-cylindrical shape.