Ship Tank Support Structure for Thermal Contraction and Heat Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing support structures for liquefied gas tanks on ships face challenges in reducing heat transfer and accommodating thermal contraction, which can lead to deformation and instability during transportation.
Innovation Solution
A hollow support unit with tubular elements arranged in the circumferential direction of the tank, where inner members are fixed and outer members are slidable, allowing for axial displacement and reduced heat transfer through the use of glass fiber reinforced plastic and a vacuum space between the tank and outer shell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If block-shaped thermal-insulating liners are used in the support unit, then the tank can be displaced axially when thermal contraction occurs, but a large amount of heat enters the tank from the outside via the thermal-insulating liners
Solution Approach 1:
The support unit is divided into multiple tubular elements arranged in the circumferential direction, with inner members fixed to the tank and outer members slidable on the curved surface. This segmentation allows axial displacement while reducing heat transfer area compared to solid block-shaped liners.
Solution Approach 2:
The tubular elements are made of glass fiber reinforced plastic, which provides both structural support and thermal insulation properties, reducing heat transfer while maintaining the ability to accommodate thermal contraction.
2Object-affected harmful factors
If a hollow support unit with small cross-sectional area is formed to reduce heat transfer area, then heat transfer is reduced, but the support unit cannot bear the load of the tank when the ship swings
Solution Approach 1:
The support unit is segmented into multiple tubular elements arranged in the circumferential direction. Each tubular element has sufficient wall thickness to bear load while the hollow structure reduces overall heat transfer area. The distributed arrangement provides both structural strength and thermal insulation.
Solution Approach 2:
Glass fiber reinforced plastic is used for the tubular elements, providing high strength-to-weight ratio and good thermal insulation properties, allowing the hollow structure to bear tank loads while minimizing heat transfer.
3Strength
If the support unit is made rigid to bear tank load during ship swings, then load bearing capacity is improved, but thermal contraction of the tank cannot be accommodated
Solution Approach 1:
The outer members are designed to be slidable on the curved surface in the axial direction, allowing the support unit to dynamically adapt to thermal contraction of the tank while maintaining structural rigidity for load bearing during ship swings.
Solution Approach 2:
The segmented tubular element structure with slidable outer members allows independent movement to accommodate thermal contraction while the distributed rigid elements maintain overall structural strength for bearing tank loads.
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 support structure effectively bears the load of the tank during ship swings and accommodates thermal contraction, maintaining stability and reducing heat transfer to prevent liquefied gas evaporation, while keeping the gas at low temperatures for extended periods.
Implementation Method 1
a vacuum space between the tank and outer shell
Implementation Method 2
block-shaped thermal-insulating liners fitted in respective rectangular spaces surrounded by the partition walls and the holding plates, the thermal-insulating liners being in contact with the supporting surface of the saddle
Implementation Method 3
a plurality of tubular elements arranged in the circumferential direction of the tank such that an axial direction of each of the tubular elements coincides with a radial direction of the tank
Implementation Method 4
when a reduction in the length of the tank (i.e., deformation of the tank in its axial direction) occurs due to thermal contraction, displacement of one of the support units in the axial direction of the tank is restricted while the other support unit is allowed to slide
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A support structure of a ship tank, the ship tank being a horizontal type circular cylindrical tank (2) mounted on a ship and storing a liquefied gas, includes: a curved surface facing an outer peripheral surface of the tank; and a support unit (4) supporting the tank on the curved surface and extending in a circumferential direction of the tank. The support unit includes: a plurality of tubular elements (5) arranged in the circumferential direction of the tank such that an axial direction of each of the tubular elements coincides with a radial direction of the tank; a plurality of inner members (6) each holding, on the outer peripheral surface of the tank, an end portion of a corresponding one of the tubular elements at the tank side; and a plurality of outer members (7) each holding, on the curved surface, an end portion of a corresponding one of the tubular elements at an opposite side to the tank. The plurality of inner members are fixed to the tank. The plurality of outer members are configured to be slidable on the curved surface in an axial direction of the tank.