Reverse-Flow Condensing Economizer With Accessible Tube Bundles
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Solution Overview
Problem
Existing condensing heat recovery systems face inefficiencies due to re-evaporation of condensate and maintenance challenges, particularly in cylindrical designs where tubes are inaccessible and difficult to assemble.
Innovation Solution
A reverse flow economizer design with a main duct and multiple reverse flow passages, where flue gas is redirected downward through heat exchange tubes, forming condensate that is not re-vaporized, and cooled gas is redirected upward through return passages, with adjustable dampers and accessible heat exchange tubes for easy maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If cylindrical inner and outer shells are used with heat exchange tubes in the inner zone, then reverse flow heat recovery is achieved, but assembly is laborious and maintenance is difficult
Solution Approach 1:
The patent segments the heat exchange tube assembly into modular sections that can be independently accessed and serviced. The rectangular shell design incorporates access panels that allow technicians to reach the heat exchange tubes without disassembling the entire structure, dividing the maintenance task into manageable sections rather than requiring complete system disassembly as in cylindrical designs.
Solution Approach 2:
The patent introduces access panels as intermediary elements between the external environment and the heat exchange tubes. These panels serve as mediators that provide direct access to the tubes for maintenance while maintaining the structural integrity and sealing of the overall economizer housing, eliminating the need for complex disassembly procedures.
2Volume of moving object
If heat exchange tubes are positioned in the inner zone between flow ducts, then compact design is achieved, but tubes become inaccessible for maintenance
Solution Approach 1:
The patent transitions from a three-dimensional nested cylindrical arrangement where tubes are buried in an inaccessible inner zone to a two-dimensional planar arrangement on the outer surface of a rectangular shell. This dimensional change allows the tubes to be positioned in a compact configuration while remaining accessible from the exterior through access panels, solving both compactness and maintainability requirements.
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
Enhances heat transfer efficiency while simplifying fabrication and maintenance by preventing condensate re-vaporization and allowing direct access to heat exchange tubes for servicing.
Implementation Method 1
the downwardly flowing flue gas interacts with the heat exchange tubes to form condensate and cool the flue gas
Implementation Method 2
the downwardly flowing flue gas interacts with the heat exchange tubes to form condensate and cool the flue gas
Implementation Method 3
Each reverse flow passage contains a respective bundle of heat exchange tubes carrying a heat exchange medium
Implementation Method 4
the downwardly flowing flue gas interacts with the heat exchange tubes to form condensate and cool the flue gas
Data Source
AI summary
A condensing heat exchange economizer wherein upwardly flowing hot flue gas is apportioned by a damper among a plurality of reverse flow passages and redirected to flow in a downward direction through the reverse flow passages over respective bundles of heat exchange tubes carrying a counter-flowing heat exchange medium to form condensate and cool the flue gas. The economizer may comprise a housing having a main flow duct defining a main flow passage in which the damper is located, a pair of conduits opposing one another across the main flow duct and defining respective reverse flow passages, and a pair of return channels opposing one another across the main flow duct and defining respective return flow passages. The cooled flue gas may be merged with the main flow passage at a location above the damper.