Fired heat exchanger
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Solution Overview
Problem
Existing fired heat exchangers in condensing boilers face challenges in optimizing liquid flow to mitigate lime scale deposition, as they often result in inefficient temperature control and flow speed under the combustion chamber, leading to suboptimal heat exchange and increased maintenance needs.
Innovation Solution
The implementation of a spiral baffle system that begins at a central opening, directing the liquid flow in spiral ducts between the top horizontal baffle and the sieve bottom, allowing for controlled temperature and flow speed optimization, thereby reducing lime scale deposition and enhancing heat exchange efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid flow speed under the combustion chamber is increased to reduce lime scale deposition, then heat exchange efficiency improves, but flow resistance increases
Solution Approach 1:
The patent employs a spiral baffle configuration that creates curved, spiral flow paths for the liquid under the combustion chamber. This curved geometry transforms the linear flow into a rotational pattern, increasing the velocity and shear stress on the chamber surface to prevent lime scale deposition, while the gradual spiral nature maintains acceptable pressure drop characteristics
Solution Approach 2:
The invention utilizes hydraulic principles by designing a baffle system that leverages the kinetic energy and flow dynamics of the liquid itself to achieve the cleaning effect. The spiral baffle configuration creates a self-sustaining flow pattern where the liquid's own motion generates the necessary shear forces to prevent deposition without requiring additional energy input or complex mechanical components
2Reliability
If temperature control under the combustion chamber is optimized to prevent lime scale, then heat exchange efficiency improves, but energy loss increases
Solution Approach 1:
The spiral baffle system allows the liquid flow to self-regulate and self-optimize the temperature distribution under the combustion chamber. The curved flow paths naturally create zones of varying velocity and heat transfer coefficient, with the system automatically adjusting the thermal field to maintain conditions unfavorable for lime scale deposition without external control mechanisms or additional energy consumption
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 optimizes liquid flow, reducing lime scale deposition and maintaining acceptable flow resistance, resulting in improved heat exchange efficiency and extended equipment lifespan by controlling temperature and flow speed effectively.
Implementation Method 1
a spiral baffle (11) which forms spiral ducts (13) for the flow of the liquid
Implementation Method 2
a set of vertical tubular elements (2) circular in cross-section... through which the heated water flows
Implementation Method 3
the water heated by the gases circulates around the tube sets
Implementation Method 4
exchanging heat between gas and liquid
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
The fired heat exchanger fitted with a chamber for the liquid encased in an outer jacket (1) which features a liquid inlet (7) and outlet (8), where inside the chamber there is a set of vertical tubular elements (2) for the flow of the fumes and at least one transverse baffle, and where the ends of the tubular elements are anchored in the sieve bottom (3) of the combustion chamber (4) on the one side, and in the sieve wall (5) of the condensate tank (6) featuring gas and condensate discharge stub pipes on the opposite side is characterized in that mounted close to the sieve bottom (3) of the combustion chamber (4), inside the chamber for the liquid, is a horizontal top baffle (9) with a single central opening (12) for the flow of the liquid, fitted with at least one vertical spiral baffle (11) adhering tightly to the sieve bottom (3) and to the top horizontal baffle (9), where the spiral baffle forms spiral ducts (13) for the flow of the liquid under the sieve bottom (3).