Air Distribution Cones for Circulating Fluidized Bed Boiler
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large-size circulating fluidized bed boilers face challenges in secondary air penetration and heating surface arrangement, leading to imbalanced heat emission and absorption, which can result in bed-overturn and deformation issues.
Innovation Solution
The design incorporates air distribution cones with membrane walls and T or Y-shaped extended heating panels, allowing for improved secondary air distribution and increased heating surface area, while enhancing the rigidity of the panel to prevent deformation and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the furnace cross section is increased to enlarge boiler capacity, then the boiler capacity increases, but the secondary air cannot reach the center of the furnace
Solution Approach 1:
The air distribution plate is divided into multiple independent air distribution cones, each with its own air distribution channels. This segmentation allows secondary air to be distributed through multiple pathways, enabling the air to reach the furnace center even when the furnace cross-section is enlarged, thus resolving the contradiction between increased boiler capacity and maintained air penetration effectiveness.
2Temperature
If the heat emission volume of the furnace is increased to raise steam parameters, then the steam parameters increase, but the imbalance between heat emission and heat absorption worsens
Solution Approach 1:
T-shaped or Y-shaped extended heating panels are added vertically above the air distribution cones, introducing a new vertical dimension for heat absorption. This increases the evaporation heating surface area without expanding the furnace cross-section, allowing the furnace to absorb the increased heat emission from higher steam parameters while maintaining heat emission-absorption balance.
3Ease of operation
If the furnace is divided into two separate undershorts legs to improve secondary air penetration, then secondary air distribution improves, but pressure fluctuation causes bed-overturn phenomenon
Solution Approach 1:
Multiple air distribution cones are arranged within a single unified furnace chamber rather than separating the furnace into two independent undershorts legs. This merging approach maintains good secondary air distribution through the multiple cones while keeping the furnace structure integrated, preventing pressure fluctuations that would cause bed-overturn and ensuring stable operation.
4Area of stationary object
If the height of intermediate-partition-water-wall panel is increased to match increased furnace height, then the heating surface area increases, but the panel strength becomes insufficient causing deformation and vibration
Solution Approach 1:
The extended heating surface is divided into multiple T-shaped or Y-shaped panels arranged vertically above different air distribution cones, rather than using a single tall intermediate partition panel. This segmentation reduces the height and structural load on each individual panel, maintaining sufficient strength while collectively providing the required total heating surface area.
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 solution ensures uniform air flow, prevents bed-overturn, and increases the heating surface area, enhancing combustion efficiency and operational safety by allowing secondary air to reach the furnace center and reducing the risk of tube burst.
Implementation Method 1
secondary air ports are provided in the cone side walls facing towards the furnace combustion space... ensures uniform air flow, allowing secondary air to reach the furnace center
Implementation Method 2
T or Y-shaped extended heating panels... increases the heating surface area, enhancing combustion efficiency
Implementation Method 3
enhancing the rigidity of the panel to prevent deformation and vibration... reducing the risk of tube burst
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention provides a circulating fluidized bed boiler, comprising: furnace side walls; a ceiling; an air distribution plate provided at a bottom of a furnace; and at least one air distribution cone provided on the air distribution plate, wherein each air distribution cone extends upwards from the air distribution plate into an interior of the furnace and has a shape gradually tapered in an extending direction, cone side walls which form the air distribution cone are provided with secondary air ports, the cone side walls are separated from the furnace side walls, and a furnace combustion space is formed and surrounded by the ceiling, the furnace side walls, the air distribution plate, and the cone side walls. The present invention further relates to an air distributor for a circulating fluidized bed boiler, the air distributor being provided on an air distribution plate of the boiler, wherein the air distributor is in a form of an air distribution cone, which extends upwards from the air distribution plate into an interior of a furnace to form a shape gradually tapered in an extending direction, and secondary air ports are formed in air distribution cone side walls forming the air distribution cone. The present invention also relates to an air distributor assembly for a circulating fluidized bed boiler.