A method, system and a heat exchanger for heating subareas of apartments in buildings, such as a bathroom of an apartment

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Solution Overview

Problem

Existing systems fail to efficiently connect underfloor heating to domestic hot water circulation loops due to temperature limitations, leading to the use of electricity for heating subareas like bathrooms, which hinders energy efficiency and primary energy reduction.

Innovation Solution

A dedicated local water circulation loop with a coaxial heat exchanger, operating on the counter-current principle, transfers heating energy from the domestic hot water circulation loop to the local loop, allowing for controlled heating power and efficient heat transfer with a high terminal temperature difference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a heating device is directly connected to the domestic hot water circulation loop, then heating can be provided, but the temperature of domestic water falls below 55°C making traditional underfloor heating impossible

Engineering Contradiction:
Improvedomestic water temperatureVSAvoidheating system safety
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The system divides the heating function into two separate loops: the domestic hot water circulation loop and the local heating circulation loop. The heat exchanger acts as an intermediary that transfers thermal energy between these two independent loops, allowing each to operate at its optimal temperature without compromising safety or functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A heat exchanger is introduced as an intermediary device between the domestic hot water loop and the local heating loop. This mediator transfers heating energy from the domestic water to the local circulation system without allowing direct thermal mixing, thereby maintaining the temperature requirements of both systems independently.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If electricity is used for heating subareas like bathrooms, then heating can be provided, but energy efficiency and primary energy consumption are worsened

Engineering Contradiction:
Improveheating availabilityVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system utilizes the existing domestic hot water circulation loop, which is already heated by the building's hot water system, to provide additional heating for subareas. The heating system serves itself by recycling thermal energy that would otherwise be wasted in the return water, eliminating the need for separate electrical heating equipment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system recovers thermal energy from the domestic hot water return line that would otherwise be discarded. By capturing and redistributing this waste heat to local heating circuits, the system converts wasted energy into useful heating, significantly reducing overall energy consumption and primary energy requirements.

Inventive Principle:
Principle #34Discarding and recovering

3Use of energy by moving object

If a heat exchanger is used to transfer heating energy, then energy efficiency is improved, but the system complexity increases

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcirculation loop structure
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The heat exchanger unit serves multiple functions simultaneously: it transfers thermal energy from the domestic hot water loop to the local heating loop, maintains temperature control, and enables independent operation of both circulation systems. This multi-functionality justifies the added complexity by delivering multiple benefits from a single integrated component.

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

Solution Approach 2:

The local heating circulation loop is nested within the broader domestic hot water circulation system. The heat exchanger is integrated into the existing plumbing infrastructure, with the local loop effectively embedded within the larger system framework, minimizing the additional complexity while maximizing energy efficiency.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Enables safe and efficient heating of subareas using the domestic hot water circulation loop, reducing energy consumption and improving energy efficiency by allowing underfloor heating to be connected without the risks associated with prior solutions.

Implementation Method 1

a heat exchanger located in the subarea, where the preferred heat exchanger is arranged between the domestic water circulation loop and the local water circulation loop for transferring heating energy from the domestic water circulation system to the local water circulation loop

Methodology Applied
Scientific EffectHeat exchanger: Heat Exchanger

Implementation Method 2

one water circulation loop is arranged within the inner pipe and another one to flow in the jacket space of the jacket pipe based on the counter-current principle

Methodology Applied
Scientific EffectCounter-current principle: Convection

Data Source

PatentEP3746711B1A method, system and a heat exchanger for heating subareas of apartments in buildings, such as a bathroom of an apartment
Publication Date: 2022.02.23 HOLOPAINEN TIMO
  • EP3746711B1 patent drawingFigure 1
  • EP3746711B1 patent drawingFigure 2
  • EP3746711B1 patent drawingFigure 3

AI summary

The invention is related to a method for heating (22) subareas of apartments, such as a bathroom of an apartment, in a building provided with a domestic hot water circulation loop (11a, 11b) for supplying domestic hot water to points of use in apartments at a pre-set temperature and wherein heating of each subarea is performed with the heating energy of domestic water, a dedicated local water circulation loop (10, 22) is circulated in the subarea, to which heating energy is transferred from the domestic water circulation loop using a heat exchanger (15) placed in the subarea. The invention is also related to a system and a heat exchanger.