Multi-Tank Hot Water Control Using Wavelet Load Curve Decomposition

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Solution Overview

Problem

Current methods are inadequate for optimizing the control and monitoring of domestic hot water production tanks in hotel complexes, particularly in distinguishing the electricity consumption of multiple tanks from a single load curve and detecting performance issues or damage, without requiring high-frequency data acquisition.

Innovation Solution

A method that acquires the fleet load curve at a low frequency, decomposes it using a dyadic basis of Gaussians, and extracts load curves for individual tanks, allowing for the identification of start and stop times, and detection of damage or inefficiencies, enabling optimized control and management of hot water production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If wavelet decomposition is used to extract DHW power curve from load curve, then DHW production curve can be estimated, but the method is limited to single tank case and cannot differentiate consumption of multiple tanks

Engineering Contradiction:
ImproveDHW production curve estimation accuracyVSAvoidApplicability to multiple tank systems
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent segments the total load curve into individual tank consumption curves by identifying characteristic patterns for each tank. The method decomposes the aggregate load curve into multiple component curves, each representing a specific tank's electricity consumption, enabling individual monitoring and control of each tank in a multi-tank system.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If high-frequency data acquisition is implemented to extract DHW consumption from total load curve, then consumption can be accurately differentiated, but implementation cost becomes prohibitive

Engineering Contradiction:
ImproveConsumption differentiation accuracyVSAvoidData acquisition frequency requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces high-frequency physical data acquisition with a signal processing approach using wavelet decomposition on standard-frequency load curve data. Instead of requiring expensive high-speed meters, the method uses mathematical transformation to extract tank-specific consumption patterns from routinely collected load curve data at standard frequencies.

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

3Reliability

If multiple tanks are operated during peak hours to meet high occupancy demand, then DHW sufficiency is improved, but electricity cost increases

Engineering Contradiction:
ImproveDHW sufficiency for high occupancyVSAvoidElectricity consumption cost
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements feedback control by continuously monitoring the extracted load curves of individual tanks and using this information to optimize tank operation. The system adjusts tank operation based on actual consumption patterns and hot water demand forecasts, enabling intelligent scheduling that meets occupancy needs while minimizing peak-hour electricity costs through off-peak pre-heating when possible.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3502809B1Method for controlling sanitary hot water tanks
Publication Date: 2020.12.16 ELECTRICITE DE FRANCE
  • EP3502809B1 patent drawingFigure 1
  • EP3502809B1 patent drawingFigure 2
  • EP3502809B1 patent drawingFigure 3

AI summary

The invention relates to a method for controlling a set of electrical equipment (1) comprising a plurality (10) of domestic hot water production tanks (101, 102, 103), the method comprising the steps of: - acquiring the load curve of the set (1), - extracting the load curve corresponding to the plurality (10) of tanks (101, 102, 103), - extracting the load curve corresponding to each tank (101, 102, 103), and - controlling all the tanks (101, 102, 103).