Three-Fluid Heat Exchanger for Simultaneous Domestic and Heating Water

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Solution Overview

Problem

Existing combined devices for heating sanitary water and room water struggle with optimized operation and compact installation due to inefficient energy performance, large size, and high mass, which limits their installation flexibility and user comfort.

Innovation Solution

A combined device featuring a three-fluid heat exchanger with nested pipes for simultaneous heating of sanitary and heating water, allowing direct heat exchange between a heat transfer fluid and both types of water, reducing the need for separate heating circuits and optimizing energy performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If selective or alternating operation between heating water circuits is used, then device complexity is reduced, but energy performance deteriorates significantly during rapid heating phases

Engineering Contradiction:
Improveheating circuit configurationVSAvoidenergy performance
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The heating system is segmented into independent circuits: a first heating water circuit for room heating and a second heating water circuit for domestic hot water, each with dedicated heat exchangers. This allows simultaneous operation of both circuits without selective switching, eliminating energy losses during transition phases while maintaining manageable system complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heat pump system is designed with multi-functionality to serve dual purposes simultaneously: heating the room via radiators and heating domestic water for sanitary use. The heat pump can operate in parallel modes to provide both heating functions at the same time, optimizing energy performance by avoiding the need to switch between single-function modes.

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

2Reliability

If separate heat exchangers for sanitary water and heating water are used, then heating effectiveness is improved, but device size and mass increase significantly

Engineering Contradiction:
Improveheating effectivenessVSAvoiddevice mass
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The heat exchangers are arranged in a nested configuration where the second heat exchanger for domestic hot water is positioned inside or around the first heat exchanger for heating water. This nested arrangement allows both heat exchangers to occupy overlapping spatial volumes, significantly reducing the overall device footprint and mass while maintaining the heating effectiveness of separate heat exchange surfaces.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Device complexity

If indirect domestic water heating through heating water is used, then system simplicity is improved, but temperature set point compliance deteriorates during sanitary water heating

Engineering Contradiction:
Improveheating circuit configurationVSAvoidtemperature set point compliance
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The system is segmented into independent heating circuits with dedicated heat exchangers, allowing the second heat exchanger for domestic hot water to operate independently from the first heat exchanger for heating water. This independence enables direct heating of sanitary water to the required temperature set point without being constrained by the temperature requirements of the heating water circuit, ensuring compliance while maintaining system simplicity.

Inventive Principle:
Principle #1Segmentation

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 enhances energy performance by over 30% compared to selective operation, reduces device size and cost, and allows for more flexible installation, including the possibility of suspending the device above the ground.

Implementation Method 1

a heat exchanger (58) in which a heat transfer fluid is adapted to circulate via a heat transfer fluid circuit (62), the exchanger being configured to carry out a heat exchange: between the heat transfer fluid and sanitary water present in the sanitary water circuit (54), and between the heat transfer fluid and heating water present in the circuit of heating water (56)

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

the pipe wall separating the water sanitary of the heat transfer fluid being a double wall

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3637014B1Combined device for heating of domestic water and water for heating a room with three-fluid heat exchanger
Publication Date: 2023.04.05 SOCI IND DE CHAUFFAGE SIC
  • EP3637014B1 patent drawingFigure 1~2
  • EP3637014B1 patent drawingFigure 3~6
  • EP3637014B1 patent drawingFigure 7~8

AI summary

The invention relates to a combined device (50) for heating domestic hot water and heating water for a room, said combined device (50) comprising: - a domestic hot water storage tank (52), - a domestic hot water circuit (54) in fluid communication with the storage tank (52), - a heating water circuit (56), - a heat exchanger (58) of a heat pump in which a heat transfer fluid is able to circulate, the heat exchanger (58) being configured to carry out a heat exchange: • between the heat transfer fluid and domestic hot water present in the domestic hot water circuit (54), and • between the heat transfer fluid and heating water present in the heating water circuit (56).