Nested-Tube Exhaust Gas Heating for Compact Marine Aftertreatment
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Solution Overview
Problem
Existing exhaust gas heating devices for ship engines require a large amount of space and have limited installation flexibility due to their design and the need for specific component arrangements.
Innovation Solution
A compact exhaust gas heating device with a nested arrangement of an inner and outer tube, where the exhaust gas flow direction is opposite in sections, utilizing a burner with a pre-combustion chamber and swirl body to enhance mixing and cooling, allowing for flexible installation and efficient heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a burner tube extends into a straight exhaust line with continuous mixing, then heating efficiency is improved, but the device requires a large amount of space and has limited installation flexibility
Solution Approach 1:
The inner tube is nested within the outer tube, creating a compact concentric structure. The inner tube contains the burner and initial mixing zone, while the outer tube provides the exhaust gas flow path. This nesting arrangement achieves effective heating and mixing in a compact volume, resolving the contradiction between heating efficiency and device space requirement
Solution Approach 2:
The patent transitions from a straight linear exhaust line to a three-dimensional concentric tube structure with radial and axial flow components. The exhaust gas flows axially in the outer tube while hot gases from the burner mix radially inward, creating multi-dimensional flow patterns that achieve thorough mixing in a compact space
2Productivity
If different components are required for different mounting positions, then heating performance is optimized for each position, but installation flexibility is reduced
Solution Approach 1:
The concentric tube design with the outlet on the outer tube creates a universal structure that can be installed in various mounting positions (horizontal, vertical, angled) without requiring different components. The structure maintains its heating performance across different orientations, achieving both optimized heating and installation flexibility
Solution Approach 2:
The outlet position on the outer tube can be oriented in different directions to adapt to various installation requirements. The structure allows dynamic adaptation to different mounting positions through flexible outlet orientation while maintaining the core heating and mixing functionality
3Productivity
If the outer tube is exposed to direct burner flame, then heating efficiency is improved, but the material requirements and insulation requirements increase
Solution Approach 1:
The inner tube serves as an intermediary structure that contains the burner flame and directs hot gases toward the exhaust flow. This intermediate structure protects the outer tube from direct flame exposure while still enabling effective heat transfer to the exhaust gas, reducing material and insulation requirements for the outer tube
4Device complexity
If the exhaust gas flows in a straight line through the heating device, then the design is simple, but mixing efficiency between exhaust gas and burner gases is reduced
Solution Approach 1:
The concentric tube structure creates curved flow paths as exhaust gas flows axially in the outer tube while hot burner gases move radially inward. This curvature induces centrifugal forces and enhances turbulent mixing between the two gas streams, achieving superior mixing efficiency while maintaining design simplicity
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 device achieves efficient gas mixing and cooling, enabling rapid heating of exhaust gas for downstream treatment, with improved installation flexibility and reduced material requirements, while maintaining a stable and controllable flame.
Implementation Method 1
a burner (20) associated with the heating channel
Implementation Method 2
The exhaust gas and the hot burner gases are swirled together
Implementation Method 3
the deflection between the inner and outer tubes alone results in good turbulence and thus good mixing of fuel gas and exhaust gas
Implementation Method 4
it ensures that the inner tube does not overheat, as exhaust gas flows around it on the outside and is thus cooled
Implementation Method 5
the flame root of the burner flame outside of the turbulent flow area at the exhaust gas inlet. Additionally, the flame root is protected by the pre-combustion chamber
Data Source
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AI summary
The invention relates to an exhaust gas heating device (10), in particular for the exhaust gas aftertreatment of the exhaust gas from ship engines, comprising an inner tube (16) having an exhaust gas inlet (14) and a transfer opening (24), between which a heating channel (26) is formed, a burner (20) associated with the heating channel (26), and an outer tube (12) surrounding the inner tube (16), such that a flow channel (30) is formed from the transfer opening (24) of the inner tube (16) to an outlet (18). The invention further relates to an exhaust gas aftertreatment system with a diesel particulate filter and a corresponding exhaust gas heating device (10).