Hot Water Tank Control for Peak-Demand Shortage Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional hot water supply devices often fail to prevent shortages of hot water, especially when there is a sudden large usage, as they only start heating when the water level falls below a predetermined minimum, leading to potential shortages and inefficiencies in energy usage.

Innovation Solution

A controller that initiates the heating operation when the hot water level drops below a first start amount and stops when it exceeds a first stop amount, with adjustments made to these thresholds based on usage patterns, particularly increasing the start amount when the largest hot water consumption period ends to ensure timely replenishment and reduce surplus hot water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the heating operation starts only when hot water level falls below a predetermined minimum amount, then energy efficiency is improved by avoiding unnecessary heating, but hot water shortages occur when large amounts of hot water are used abruptly

Engineering Contradiction:
Improveenergy efficiencyVSAvoidhot water supply reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The controller performs preliminary action by detecting when the largest amount of hot water per unit time is used and, in anticipation of further large usage, lowers the start amount threshold before the hot water level actually falls below it. This proactive approach ensures heating starts timely to prevent shortages while avoiding unnecessary heating when not needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by continuously monitoring hot water usage patterns and detecting when the largest amount of hot water per unit time is consumed. Based on this feedback, the controller dynamically adjusts the start amount threshold, creating a closed-loop control system that balances reliability and energy efficiency.

Inventive Principle:
Principle #23Feedback

2Reliability

If the minimum hot water amount is increased to prevent shortages during peak usage, then hot water supply reliability is improved, but energy efficiency deteriorates due to unnecessary heating operations

Engineering Contradiction:
Improvehot water supply reliabilityVSAvoidenergy efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system applies dynamics by making the start amount threshold variable rather than fixed. The controller dynamically adjusts the threshold based on real-time detection of usage patterns, lowering it when large usage is detected and maintaining higher levels during normal operation. This dynamic adjustment resolves the contradiction by adapting the system behavior to actual conditions.

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 solution effectively prevents hot water shortages while optimizing energy efficiency by adjusting heating operations according to usage patterns, ensuring timely replenishment during peak demand and reducing unnecessary heating during off-peak times.

Implementation Method 1

activates its heat source automatically to start a heating operation, thereby heating water that is supplied to the storage tank

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP2960586B1Hot water supply device and controller employed therein
Publication Date: 2017.03.22 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2960586B1 patent drawingFigure 1
  • EP2960586B1 patent drawingFigure 2
  • EP2960586B1 patent drawingFigure 3

AI summary

Hot water supply device (100) includes storage tank (1) for storing hot water, heat source (2) for heating the hot water in storage tank (1), a supply channel through which the hot water in storage tank (1) or hot water heated by the hot water in storage tank (1) flows, and controller (9) for carrying out a heating operation that heats the hot water in storage tank (1). Controller (9) starts the heating operation when an amount of hot water in storage tank (1) decreases equal to or smaller than a first start amount, and ends the heating operation when the amount of hot water in storage tank (1) increases equal to or greater than a first stop amount. Controller (9) changes the amount of hot water in tank (1) before starting the heating operation to a second start amount greater than the first start amount when a supply of hot water takes place by an end of a given time zone, in which the largest amount of hot water per unit time is consumed, within an operation cycle.