Method for learning the pattern of hot water withdrawals in a storage water heater

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Solution Overview

Problem

Existing storage water heaters face inefficiencies due to high thermal losses and the need for constant high temperatures, which are not always necessary, as they are designed to meet peak demand while wasting energy during off-peak times, and current methods for managing temperature based on user habits are either inaccurate or require additional sensors.

Innovation Solution

A method that uses local temperature sensors to accurately determine withdrawal patterns and heating speeds without direct measurement of storage temperature, allowing for adaptive management of storage temperature to minimize heat losses while ensuring user needs are met, by calculating the reduction in storage temperature caused by withdrawals and estimating heating speed based on temperature variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the storage temperature is maintained at high values to satisfy peak demand, then the water heater can meet the largest foreseeable withdrawal, but thermal losses increase significantly during off-peak times

Engineering Contradiction:
Improveability to satisfy largest withdrawalVSAvoidthermal losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent implements dynamic temperature management by continuously monitoring local temperature variations and adjusting the storage temperature based on actual withdrawal patterns. The system transitions from static high-temperature maintenance to dynamic adaptation, reducing temperature when withdrawals are low and maintaining it when withdrawals occur, thereby resolving the contradiction between reliability and energy loss.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses self-learning capabilities to automatically detect withdrawal patterns and predict future withdrawals without user intervention. By monitoring local temperature changes and calculating heating speeds, the system autonomously adjusts storage temperature management, eliminating the need for manual programming while optimizing energy efficiency against thermal losses.

Inventive Principle:
Principle #25Self-service

2Loss of energy

If the storage temperature is reduced to minimize thermal losses, then energy efficiency improves, but the ability to satisfy unexpected or large withdrawals deteriorates

Engineering Contradiction:
Improvethermal lossesVSAvoidability to satisfy withdrawals
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent implements feedback mechanisms by continuously monitoring local temperature variations and using this information to adjust storage temperature management. The system calculates heating speeds based on temperature changes and uses this feedback to predict withdrawal timing and magnitude, then proactively adjusts storage temperature to ensure sufficient hot water availability while minimizing energy losses.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary actions by predicting future withdrawals based on detected patterns and proactively adjusting storage temperature before withdrawals occur. This allows the system to maintain optimal temperature levels in advance, ensuring reliability when withdrawals happen while avoiding unnecessary heating during off-peak periods.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If additional sensors are installed to directly measure storage temperature for accurate withdrawal pattern detection, then measurement precision improves, but device complexity and cost increase

Engineering Contradiction:
Improvestorage temperature measurementVSAvoidsensor requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses local temperature sensors as intermediaries to indirectly measure storage temperature characteristics. Instead of directly measuring storage temperature, the system monitors temperature variations at local points and uses these measurements to calculate heating speeds and detect withdrawal patterns, thereby achieving accurate measurement without direct storage temperature sensing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces direct mechanical/physical measurement of storage temperature with a computational approach. By monitoring local temperature variations and calculating heating speeds through mathematical relationships, the system substitutes direct measurement with indirect detection and computation, reducing sensor requirements while maintaining measurement precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of manufacture

If the tank volume is reduced to lower cost, then manufacturing cost decreases, but the ability to deliver high water flows deteriorates

Engineering Contradiction:
Improvetank volume costVSAvoidwater flow delivery
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent changes the operational parameters of the water heater by implementing dynamic temperature management. Instead of relying solely on large tank volume to ensure sufficient hot water supply, the system optimizes the temperature parameter, maintaining higher storage temperatures during withdrawal periods and reducing them during off-peak times, thereby enabling smaller tanks to deliver equivalent or superior performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system introduces dynamic temperature control to compensate for reduced tank volume. By continuously adjusting storage temperature based on detected withdrawal patterns and calculated heating speeds, the system ensures that smaller tanks can rapidly heat and deliver sufficient hot water flows when needed, replacing the static approach of oversized tanks with dynamic optimization.

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

This approach reduces energy consumption by optimizing storage temperature management, minimizing unnecessary heating and cooling, and providing accurate estimation of water withdrawals, thus enhancing the efficiency of storage water heaters.

Implementation Method 1

a heating element HE which can be switched from an OFF state to an ON state and vice versa by a thermostat TR

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a thermostat TR, suitable for switching said heating element HE from the OFF state to the ON state and vice versa

Methodology Applied
Scientific EffectThermal detection:

Implementation Method 3

phases of mild cooling for thermal losses

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

phases of mild cooling for thermal losses

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 5

s said local temperature sensors S.loc.i can coincide with the temperature sensor STR of the thermostat TR

Methodology Applied
Scientific EffectThermal detection:

Data Source

PatentEP3662210B1Method for learning the pattern of hot water withdrawals in a storage water heater
Publication Date: 2021.09.15 ARISTON THERMO SPA
  • EP3662210B1 patent drawingFigure 1.a~1.b
  • EP3662210B1 patent drawingFigure 2
  • EP3662210B1 patent drawingFigure 3

AI summary

Object of the present invention is a method for learning, value and timing of the physical and thermal characteristics of the hot water drawings profile in a storage water heater, where said profile repeats cyclically at given time intervals and where there are sensors of temperature (S.loc.i) which read local temperatures (T.loc.i) whence it is possible to devise an average local temperature T.loc approximating the average storage temperature (T.acc) only in the absence of turbulence in the storage tank (S). According to the invention, the amount of each water withdrawal or cluster of withdrawals is considered represented by the reduction (AT.tap) of the storage temperature (T.acc) caused by the water withdrawal and is calculated a posteriori, once the withdrawal is terminated at a time t3 during or at the end of a subsequent heating phase triggered by the reduction of the local temperature (T.loc) caused by the withdrawal and is considered equal to the difference between storage temperature (T.acc) a time before the start of withdrawal and the storage temperature (T.acc) at time t3 plus the increase (ΔΤ) of storage temperature (T.acc) caused by the heating itself. The main advantage of the method of the invention is that the determination of the extent of the withdrawals is not affected by the fact that said local temperatures (T.loc.i), the only ones that can be measured directly, are not generally representative of the temperature (T.acc) average of water in the storage tank.