Thermal Storage Vessel Pre-Heating Domestic Hot Water

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Solution Overview

Problem

Existing systems for providing domestic hot water and space heating in buildings are inefficient, wasteful, and uneconomical due to thermal energy dissipation during non-demand periods and reliance on expensive or non-renewable electricity during peak demand.

Innovation Solution

A system with a thermal storage vessel equipped with a pre-heating heat exchanger and control valves to utilize stored thermal energy for domestic hot water pre-heating, allowing energy storage flexibility and reducing heat pump operation during peak demand.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a thermal storage vessel is used for space heating only, then space heating function is provided, but heat energy is wasted during warmer seasons when space heating demand is low

Engineering Contradiction:
Improveheat energy wasteVSAvoidthermal storage vessel usage
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The thermal storage vessel is designed to serve multiple functions: it can provide space heating through the heat emitter circuit line and simultaneously pre-heat domestic hot water through the pre-heating heat exchanger. This multi-functionality allows the stored thermal energy to be utilized for both space heating and domestic hot water preparation, eliminating the waste of heat energy during warmer seasons when space heating demand is low.

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

2Productivity

If the heat pump operates during periods of high domestic hot water demand, then domestic hot water is provided, but electricity consumption increases during expensive or non-ecological tariff periods

Engineering Contradiction:
Improvedomestic hot water provisionVSAvoidelectricity consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The system stores thermal energy in advance in the thermal storage vessel during periods when electricity is cheaper and more ecological (such as nighttime or periods with renewable energy availability). The pre-heating heat exchanger then utilizes this stored energy to pre-heat domestic hot water during peak demand periods, avoiding the need to operate the heat pump during expensive or non-ecological tariff periods.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the thermal storage vessel energy is used only for space heating, then space heating demand is met, but the energy cannot be utilized during periods with no space heating demand

Engineering Contradiction:
Improvespace heating demand fulfillmentVSAvoidstored heat energy utilization
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The thermal storage vessel is designed to serve multiple functions: it can provide space heating through the heat emitter circuit line and simultaneously pre-heat domestic hot water through the pre-heating heat exchanger. This multi-functionality allows the stored thermal energy to be utilized for both space heating and domestic hot water preparation, eliminating the waste of heat energy during warmer seasons when space heating demand is low.

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

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

Enhances energy efficiency, economics, and ecology by utilizing thermal storage for both space heating and domestic hot water, reducing waste and reliance on expensive electricity, and optimizing heat pump operation.

Implementation Method 1

the pre-heating heat exchanger is suitable for exchanging heat energy between the heat transfer fluid of the thermal storage vessel and water flowing from the cold water mains inlet to the domestic hot water cylinder unit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a domestic hot water heat exchanger which is suitable for exchanging heat energy between the domestic hot water cylinder unit and the primary heat transfer fluid circuit line

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

an air-to-water heat pump comprising a heat pump heat exchanger, wherein the heat pump heat exchanger is fluidly connected to a primary heat transfer fluid circuit line of the system

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4624827A1System for providing domestic hot water and space heating within a building
Publication Date: 2025.10.01 MITSUBISHI ELECTRIC CORP
  • EP4624827A1 patent drawingFigure 1
  • EP4624827A1 patent drawingFigure 2
  • EP4624827A1 patent drawingFigure 3

AI summary

A system for providing domestic hot water (DHW) and space heating (SH) within a building is provided, comprising a cold water mains inlet, a heat pump connected to a primary heat transfer fluid circuit line of the system, a domestic hot water cylinder unit fluidly connected to the cold water mains inlet and fluidly connected to a hot water outlet, a domestic hot water heat exchanger, a thermal storage vessel containing a heat transfer fluid, and a controller. The thermal storage vessel comprises a pre-heating heat exchanger which is fluidly connected to the domestic hot water cylinder unit and is fluidly connectable to the cold water mains inlet. The pre-heating heat exchanger is suitable for exchanging heat energy between the heat transfer fluid of the thermal storage vessel and water flowing from the cold water mains inlet to the domestic hot water cylinder unit. The system prevents a wasteful loss of heat energy and allows a more energy-efficient, more economical and more ecological operation.