Multi-Lobe Composite Pressure Vessel for Automotive CNG Storage
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Solution Overview
Problem
Current pressure vessels for storing compressed natural gas (CNG) are large, bulky, and costly due to their metallic construction, which limits their use in automotive vehicles, and existing composite materials do not effectively address manufacturing challenges and corrosion issues.
Innovation Solution
A composite pressure vessel formed from fiber-reinforced polymer materials, such as carbon, glass, or aramid fibers in a polymer matrix, using processes like braiding, weaving, or knitting to create a lightweight, corrosion-resistant structure with optimized geometry for improved conformability and load transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metallic materials are used for pressure vessel construction, then structural strength and pressure containment are achieved, but weight increases and corrosion resistance decreases
Solution Approach 1:
The patent applies composite materials consisting of fiber reinforcement (such as carbon fiber, glass fiber, or aramid fiber) embedded in a polymer matrix resin to construct the pressure vessel. This composite structure provides high strength-to-weight ratio, achieving the required structural strength for pressure containment while significantly reducing the vessel weight compared to traditional metallic construction.
2Strength
If metallic materials are used for pressure vessel construction, then structural strength is achieved, but corrosion resistance worsens
Solution Approach 1:
The polymer matrix composite material used in the pressure vessel provides inherent corrosion resistance while maintaining structural strength. The fiber reinforcement (carbon, glass, or aramid) combined with the polymer resin creates a structure that is immune to corrosion from moisture, chemicals, and environmental factors, eliminating the corrosion issues associated with metallic construction.
3Ease of manufacture
If conventional cylindrical tank geometry is used, then manufacturing simplicity is maintained, but space utilization and conformability decrease
Solution Approach 1:
The pressure vessel is divided into multiple lobes or chambers that can be independently formed and then joined together. This segmentation allows each lobe to be manufactured using standard composite molding processes while the overall assembled structure achieves complex geometries and conformability requirements for optimized space utilization in automotive applications.
Solution Approach 2:
The patent transitions from conventional two-dimensional cylindrical geometry to a three-dimensional multi-lobed structure with varying cross-sections along the longitudinal axis. This dimensional complexity allows the vessel to conform to available installation spaces while maintaining manufacturing feasibility through modular construction and joining of individual lobe sections.
4Adaptability or versatility
If high conformability vessel geometry is achieved, then space utilization improves, but manufacturing complexity increases
Solution Approach 1:
By dividing the complex conformable vessel into multiple simpler lobe sections, each with manageable geometry, the manufacturing complexity of individual components is reduced while the overall assembled structure achieves the required conformability. Standard composite molding processes can be applied to each lobe separately.
Solution Approach 2:
Mandrels or molds are prepared in advance with the specific complex geometries required for the conformable vessel shape. These pre-fabricated forming tools enable the production of complex multi-lobed structures using conventional composite layup and curing processes, thereby managing manufacturing complexity through preliminary tooling preparation.
5Weight of moving object
If fiber-reinforced polymer composite materials are used, then weight is reduced and corrosion resistance improves, but manufacturing process complexity increases
Solution Approach 1:
The patent utilizes fiber-reinforced polymer composite materials with fiber orientations specifically designed to match the principal stress trajectories in the pressure vessel. This optimized fiber placement maximizes structural efficiency and minimizes material usage, achieving weight reduction while the modular lobe construction keeps manufacturing processes manageable through standard composite fabrication techniques.
Data Source
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AI summary
A composite pressure vessel assembly includes a plurality of lobes, each of the lobes having at least one interior wall and at least one curved wall, the plurality of lobes being positioned in a side by side arrangement and extending in a longitudinal direction from a first end to a second end. Also included is a plurality of end caps disposed at the ends of the lobes, wherein the plurality of lobes and end caps are formed of at least one fiber-reinforced polymer. A method of manufacturing a composite pressure vessel assembly is provided. The method includes forming a plurality of lobes consisting of at least one fiber-reinforced polymer. The method also includes forming a main body with the plurality of lobes, the lobes disposed in a side by side arrangement.