Heat exchanger system with improved performance and improved compactness

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Solution Overview

Problem

Existing heat exchanger systems for building walls face challenges in compactness and energy performance, particularly in renovation applications, where they need to efficiently transfer heat and humidity while minimizing risks of overheating, cold spots, and condensation.

Innovation Solution

A heat exchanger system with a double air flow counter-current design integrated into a building wall, featuring an outer casing with specific air channel configurations that create a quasi-adiabatic peripheral buffer zone, using stale air for better thermal balance and insulation, and a compact design with controllable bypass mechanisms to manage external climatic conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the heat exchanger system is integrated into building walls with compact design, then the space utilization and installation simplicity are improved, but the risk of overheating and cold spots increases due to limited thermal buffer zone

Engineering Contradiction:
Improveheat exchanger system thicknessVSAvoidoverheating and cold spots
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The heat exchanger system is segmented into functional zones (fresh air intake zone, fresh air distribution zone, stale air intake zone, stale air exhaust zone) arranged in a specific counter-flow configuration. This segmentation allows each zone to perform its specific function while maintaining compact overall dimensions of less than or equal to 20 cm thickness, preventing thermal gradients within the compact structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A first air channel is introduced as an intermediary thermal buffer zone that extends around the exchanger between the stale air intake cavity and the stale air exhaust cavity. This air channel acts as a thermal mediator, creating a quasi-adiabatic peripheral buffer zone that protects the heat exchanger from direct thermal shocks and reduces the risk of overheating and cold spots, while maintaining the compact integrated design

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the heat exchanger system uses traditional insulation methods, then the thermal protection is provided, but the system complexity and space requirement increase

Engineering Contradiction:
Improvethermal protectionVSAvoidinsulation structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The first air channel serving as thermal insulation is integrated into the existing stale air bypass system, allowing it to perform multiple functions: it acts as thermal insulation protecting the heat exchanger, provides a pathway for stale air bypass, and creates a quasi-adiabatic peripheral buffer zone. This multi-functionality reduces device complexity by eliminating the need for separate insulation structures while maintaining effective thermal protection

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own stale air flow to create the thermal buffer zone in the first air channel, rather than requiring external insulation materials or active heating/cooling systems. The stale air naturally circulating through the first air channel provides self-service thermal protection, reducing system complexity and additional space requirements

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the heat exchanger system operates in all climatic conditions, then the ventilation needs are met, but the energy efficiency decreases due to unnecessary heat exchange in favorable conditions

Engineering Contradiction:
Improveclimatic condition adaptabilityVSAvoidenergy degradation
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The controllable bypass means in the first air channel enable dynamic operation of the heat exchanger system. The bypass can be opened or closed depending on climatic conditions - when fresh outside air is colder than inside air (summer), the bypass is opened to allow stale air to flow through the first air channel and bypass the heat exchanger, preventing unnecessary heat exchange and energy loss. This dynamic adaptation maintains ventilation needs while optimizing energy efficiency across different climatic conditions

Inventive Principle:
Principle #15Dynamics

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 system enhances energy performance by reducing thermal gradients, minimizing risks of overheating and condensation, and maintaining energy efficiency through a compact and well-insulated design, suitable for integration into building walls with simplified installation and maintenance.

Implementation Method 1

heat transfer between the stale airflow and the fresh airflow

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

humidity transfer between these two flows, from the more humid environment to the drier one

Methodology Applied
Scientific EffectHumidity transfer: Diffusion

Implementation Method 3

the air trapped in the first air channel acts as a dead air volume whose temperature is in equilibrium with the surrounding environment of the heat exchanger system. It then constitutes peripheral insulation that protects the heat exchanger

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 4

stale air allows for better thermal equilibrium with the wall, i.e., the wall in which the heat exchanger system is integrated. This results in improved thermal insulation by preventing high temperature gradients

Methodology Applied
Scientific EffectThermal equilibrium: Convection

Data Source

PatentEP3198215B1Heat exchanger system with improved performance and improved compactness
Publication Date: 2019.12.25 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3198215B1 patent drawingFigure 1~2
  • EP3198215B1 patent drawingFigure 3
  • EP3198215B1 patent drawingFigure 4

AI summary

The invention relates to a heat exchanger system (100) intended to be built into a wall of a building, the system comprising an external housing (18) and a double air flow countercurrent exchanger (20) housed in this housing which comprises, at its periphery, an air duct (40a) extending around the exchanger (20) between a stale air intake cavity (54) and a stale air discharge cavity (56) into which it opens, the air duct (40a) passing externally around a fresh air intake cavity (50) and being separated from the stale air intake cavity (54) by controllable means (60) of diverting the air situated in this same cavity (54). This arrangement allows the system to be rendered multifunctional and allows it to achieve good energy performance, while at the same time being satisfactorily compact.