Curved Transition Section for Steam Generator Efficiency
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Solution Overview
Problem
Steam generators face challenges in achieving effective transitions between radiant and convection sections due to differing heat transfer requirements, leading to inefficiencies and manufacturing complexities.
Innovation Solution
A cylindrical radiant section with a circular output is connected to a transition section that smoothly transitions to a rectangular convection section, eliminating the need for a substantial target wall and optimizing heat transfer by allowing combustion gases to flow directly from the radiant to the convection section without obstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a conventional transition section with a target wall is used to connect radiant and convection sections, then the structural transition from circular to rectangular shape is achieved, but thermal losses increase and manufacturing complexity increases
Solution Approach 1:
The transition section employs curved surfaces instead of flat target walls to connect the circular radiant section to the rectangular convection section. This curved geometry eliminates abrupt flow direction changes and reduces thermal losses by maintaining smoother combustion gas flow paths, directly resolving the contradiction between achieving shape transition and minimizing energy loss.
2Shape
If a target wall is installed in the transition section, then the structural transition is achieved, but mechanical fatigue risk increases due to stress concentration
Solution Approach 1:
The curved geometry of the transition section eliminates sharp corners and abrupt transitions that create stress concentration points. By using continuous curved surfaces, the design distributes mechanical stresses more evenly throughout the structure, reducing fatigue risk while achieving the required shape transition.
Solution Approach 2:
The invention removes the target wall component entirely from the transition section. By extracting this problematic element that causes both thermal losses and stress concentration, the design achieves shape transition through alternative curved geometries that eliminate the sources of mechanical fatigue and energy loss.
3Ease of manufacture
If the radiant section output diameter is reduced to match convection section input, then connection is simplified, but combustion gas flow is obstructed and heat transfer efficiency decreases
Solution Approach 1:
The curved transition section maintains a consistent circular output diameter from the radiant section, preventing flow obstruction. The curvature allows the combustion gases to flow smoothly without abrupt contractions or expansions, maintaining high heat transfer efficiency while achieving connection to the rectangular convection section.
Solution Approach 2:
The transition section uses three-dimensional curved surfaces to bridge the dimensional difference between circular and rectangular sections. Rather than reducing the diameter in a single dimension, the curved geometry distributes the transition across multiple dimensions, maintaining flow area while achieving shape change.
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
This design enhances heat transfer efficiency by minimizing thermal losses and reducing the risk of mechanical fatigue, allowing all tubes in the convection section to remain within the combustion gas flow and maintaining high efficiency in both radiant and convective heat transfer processes.
Implementation Method 1
a radiant section may position the fluid tubes in line-of-sight with the heat source (e.g., a flame)
Implementation Method 2
The heat source can be derived from combustion of one or more fuels
Implementation Method 3
a convection section may position the fluid tubes directly in the flow path of the combustion gases downstream of the flame in order to maximize radiant and convective heat transfer
Data Source
AI summary
Modern steam generators typically include a radiant section and a convection section. Due to differing performance requirements of the radiant and convection sections, the radiant section often has a round cross-section, while the convection section often has a rectangular cross-section. Previous designs utilized a target wall to affect the transition. An angled transition section is disclosed herein that substantially eliminates the target wall and/or the reverse target and provides a corresponding improvement in steam generator efficiency.