Tapering Boiler End Wall Steam Pipe Arrangement

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Solution Overview

Problem

In high-power circulating fluidized bed once-through steam generation boilers, achieving uniform heat exchange across the tapering lower sections of the end walls is challenging, leading to uneven heat delivery and increased risk of leaks due to varying pipe lengths and diameters required for welding.

Innovation Solution

The design features a tapering end wall structure with two groups of steam pipes, where one group passes perpendicularly and the other at an angle, ensuring equal heat exposure and eliminating the need for pipe size reduction, with a gas-tight space between them for medium delivery and measurement transducers, and refractory coating for reduced abrasion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If steam generator pipes are arranged in the tapering lower section of the end wall, then the evaporation and superheating area is increased, but the heat exchange becomes uneven and pipe lengths/diameters must vary causing welding complexity

Engineering Contradiction:
Improveevaporation and superheating areaVSAvoidpipe arrangement complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a gas-tight space with different structural characteristics within the tapering section. This localized space with uniform heat exchange properties allows pipes to maintain consistent dimensions while still benefiting from the overall increased surface area provided by the tapering wall configuration.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The tapering end wall is segmented into two distinct zones: the gas-tight space with uniform heat exchange and the surrounding tapering structure. This segmentation allows different pipe arrangements in different zones, with pipes in the gas-tight space having uniform lengths and diameters, thereby reducing welding complexity while maintaining large heat exchange area.

Inventive Principle:
Principle #1Segmentation

2Reliability

If pipe lengths and diameters are varied to accommodate the tapering wall structure, then the pipes can be made equally long for uniform heat exchange, but the number of welding operations increases and leak risk increases

Engineering Contradiction:
Improveheat exchange uniformityVSAvoidwelding operations
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By creating a localized gas-tight space with uniform thermal characteristics, the patent enables pipes within this space to have consistent lengths and diameters. This local uniformity reduces the variety of welding operations needed while maintaining reliable heat exchange, directly addressing the contradiction between manufacturing ease and heat exchange uniformity.

Inventive Principle:
Principle #3Local quality

3Shape

If the lower part of the end wall tapers towards the grid, then the reaction chamber structure is optimized, but arranging steam generator pipes becomes problematic due to varying heat exposure

Engineering Contradiction:
Improvetapering wall structureVSAvoidheat exchange uniformity
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent segments the tapering wall into two functional zones: an outer tapering structure that maintains the optimized reaction chamber shape, and an inner gas-tight space with uniform heat exchange properties. This segmentation allows the wall to taper for structural optimization while creating a protected zone where pipes experience uniform heat exposure, ensuring manufacturing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gas-tight space acts as an intermediary between the tapering wall structure and the steam generator pipes. It mediates the heat transfer process by providing a uniform thermal environment for the pipes, decoupling the structural tapering from the thermal exposure of the heat exchange surfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration ensures uniform heat exchange and reduced operational risks, enhancing the boiler's efficiency and reliability by maintaining consistent heat delivery and minimizing leaks, while allowing for precise process monitoring and medium delivery.

Implementation Method 1

the heat exchange occurring on the steam generator surfaces in the pipes is uniform enough in the various parts of the furnace

Methodology Applied
Scientific EffectHeat exchange: Conduction (thermal)

Implementation Method 2

the energy released in the chemical reactions of fuel is utilized for evaporating the water flowing in the pipes

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

refractory coating for reduced abrasion

Methodology Applied
Scientific EffectAbrasion resistance: Abrasion

Implementation Method 4

bed material containing solids and e.g. fuel is fluidized by means of fluidization gas, normally by means of oxygenous primary gas required by the exothermic reactions

Methodology Applied
Scientific EffectFluidization: Fluidisation

Implementation Method 5

oxygenous primary gas required by the exothermic reactions taking place in the reaction chamber

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Implementation Method 6

when a combustion process is performed in a circulating fluidized bed once-through steam generation boiler

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2524166B1Steam generation boiler
Publication Date: 2018.01.10 SUMITOMO SHI FW ENERGIA OY
  • EP2524166B1 patent drawingFigure 1
  • EP2524166B1 patent drawingFigure 2

AI summary

The present invention relates to a steam generation boiler (10) comprising a bottom portion (12) and a roof portion (16) as well as walls (14) to extend vertically between the bottom portion and the roof portion, thus forming the reaction chamber (20) of the steam generation boiler, the walls (14) of which reaction chamber embody a structure comprising of steam generator pipes (30), and which steam generation boiler (10) comprises in its lower part at least one wall section (14.31) tapering towards the bottom portion (12). A first group (30.1) of steam pipes in said tapering wall section (14.31) is arranged to pass from the wall plane (Y-Z) into the reaction chamber (20) and extend from the wall plane (Y-Z) to the bottom portion (12) of the steam generation boiler on the side of the reaction chamber (20) forming a wall (11) in the reaction chamber (20), and a second group (30.2) of steam pipes is arranged to pass to the bottom portion along the wall plane (Y-Z).