Three-Bundle Condensing Heat Exchanger for Compact Wide-Range Heating
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Solution Overview
Problem
Existing condensation heat exchangers for gas or fuel boilers are limited in power efficiency and compactness, with the energy recovered in secondary exchangers being lower than that captured by primary exchangers, and they struggle to operate optimally across a wide range of powers without significant bulk changes.
Innovation Solution
A condensation heat exchanger with three tubular bundles, where a third primary bundle is added to communicate with the secondary bundle, allowing hot gases to pass through in a controlled manner, enabling the secondary bundle to recover heat from both primary bundles while maintaining operational efficiency and safety across a wide power range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a double exchanger configuration is used with one primary and one secondary bundle, then heat recovery efficiency is improved, but the energy recovered in the secondary exchanger remains lower than that captured by the primary exchanger, limiting overall power efficiency
Solution Approach 1:
The invention divides the heat recovery function into three separate bundles (two primary, one secondary) instead of two, allowing each bundle to handle specific portions of the thermal load. This segmentation enables the secondary bundle to receive hot gases from both primary bundles, maximizing heat recovery while maintaining manageable size for each individual bundle.
Solution Approach 2:
The invention combines the outputs of two primary bundles to feed into a single secondary bundle, merging thermal streams to maximize heat recovery. The secondary bundle receives and recovers heat from both primary bundles simultaneously, creating a synergistic effect that improves overall energy efficiency beyond what a single primary-secondary configuration could achieve.
2Loss of energy
If the exchanger size is increased to improve heat recovery capacity, then energy recovery is enhanced, but the bulk and volume of the device increases significantly
Solution Approach 1:
The invention arranges the three bundles in a compact configuration where the secondary bundle is positioned to receive gases from both primary bundles in a nested or integrated manner. This spatial arrangement allows maximum heat recovery capacity within a minimized overall volume, as the bundles work in parallel and series combinations that optimize space utilization.
Solution Approach 2:
The invention optimizes the spatial arrangement of bundles by considering three-dimensional positioning and gas flow paths. The secondary bundle is strategically positioned to access thermal energy from both primary bundles through optimized flow channels, achieving high heat recovery capacity without linearly increasing the device's external dimensions.
3Power
If the exchanger is designed for high power operation, then energy recovery is maximized, but the device cannot operate optimally across a wide range of powers without significant bulk changes
Solution Approach 1:
The invention creates a dynamic system where the three-bundle configuration allows flexible operation at different power levels. The secondary bundle can adaptively recover heat from both primary bundles regardless of their individual output levels, enabling the system to maintain optimal efficiency across a wide range of operating conditions without requiring physical reconfiguration.
Solution Approach 2:
The secondary bundle serves multiple functions by receiving and recovering heat from both primary bundles simultaneously. This multi-functional design allows the exchanger to operate efficiently whether one or both primary bundles are active, providing versatility across different power demands while maintaining a fixed compact structure.
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
The solution enhances power efficiency and compactness, allowing the exchanger to operate effectively from 25 to 500 kW with improved heat recovery and flexibility in burner operation, ensuring optimal performance and safety.
Implementation Method 1
These hot gases contain a certain amount of water in the form of steam, which is capable of condensing when it comes into contact with the wall of the secondary exchanger, once it is below the dew-point temperature, on the order of 60° C. This condensation has the effect of providing additional heat energy to the water circulating in the secondary exchanger, which additional heat energy corresponds to the latent heat of vaporization.
Implementation Method 2
This condensation has the effect of providing additional heat energy to the water circulating in the secondary exchanger, which additional heat energy corresponds to the latent heat of vaporization.
Implementation Method 3
The water, or any other fluid to be heated, circulates entirely or partially in this secondary exchanger, where it is subjected to a preheating, then in a primary exchanger, where it is subjected to an actual heating.
Implementation Method 4
the hot gases generated by the burner pass radially, or approximately radially, first through said primary bundle, from the inside to the outside, then said secondary bundle
Data Source
AI summary
This exchanger comprises a pair of primary tubular bundles (5a, 5b) surrounding a fuel or gas burner (4a, 4b), and a secondary tubular bundle (6) on which condensation of the steam contained in the burned gases discharged from the primary bundles occurs, wherein the three bundles (5a, 5b, 6) are mounted parallel, side-by-side inside a gas-tight casing (10), and communicate with one another, with means being provided in order to circulate the water to be heated, between the tubes forming the secondary bundle (6) and the tubes forming the primary bundles (5a, 5b); the casing (10) is subdivided at the level of the secondary bundle (6) by a partition (7-70) that extends both inside and outside said bundle (6), with the arrangement being such that a only a circumferential section of the latter is capable of being contacted and traversed by the hot gases coming from one of the two primary bundles (5a), and its remaining section being capable of being contacted and traversed only by the hot gases coming from the other primary bundle (5b).Household or industrial heating installation with high efficiency and low bulk.