Hot Water Mixing Control for Heating Efficiency and Overheat Safety

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Solution Overview

Problem

Conventional hot water heating devices experience reduced heat exchange efficiency when a large heating capacity is required, and there are safety concerns due to the potential for high-temperature hot water supply issues.

Innovation Solution

A hot water heating device configuration that includes a heat source machine, a hot water storage tank, a heating terminal, a circulating pump, a mixing device, and a temperature detector at the downstream side of the mixing device, with a control device that stops the circulating pump when a predetermined temperature is detected, ensuring improved heat exchange efficiency and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If hot water is conveyed from hot water storage tank to heating terminal via heat exchanger, then heat quantity can be supplied to heating terminal, but heat exchange efficiency is reduced when large heating capacity is required

Engineering Contradiction:
Improveheating capacityVSAvoidheat exchange efficiency
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent extracts the hot water directly from the storage tank and conveys it to the heating terminal without passing through a heat exchanger. This eliminates the heat exchange step that causes energy loss, allowing direct utilization of the stored hot water's thermal energy while maintaining high heating capacity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a mixing device as an intermediary component that blends hot water from the storage tank with return water from the heating terminal. This mediator allows direct conveyance of hot water to maintain efficiency while enabling temperature control and safe operation through proportional mixing.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If mixing device is used to mix hot water from storage tank with return water, then temperature control is improved, but safety risk increases if mixing device fails to detect high temperature

Engineering Contradiction:
Improvetemperature controlVSAvoidsafety against high temperature supply
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where a temperature detector continuously monitors the mixed water temperature and provides information to the control device. When the detected temperature exceeds the predetermined threshold, the control device automatically stops the circulating pump, creating a closed-loop safety system that responds to actual operating conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent takes preliminary safety action by pre-setting a temperature threshold and having the control device ready to stop the circulating pump before dangerous high-temperature conditions can cause harm. The temperature detector is positioned to detect temperatures before they reach the heating terminal, enabling preventive rather than reactive safety control.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If temperature detector is positioned at downstream side of mixing device, then high temperature detection reliability is improved, but device complexity increases

Engineering Contradiction:
Improvehigh temperature detection reliabilityVSAvoidsystem configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by positioning the temperature detector at the specific location where temperature monitoring is most critical - immediately downstream of the mixing device. This localized placement ensures the detector captures the highest temperature point in the system, providing reliable safety detection without requiring multiple sensors throughout the entire system.

Inventive Principle:
Principle #3Local quality

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

The solution enhances heat exchange efficiency and safety by directly conveying hot water from the storage tank to the heating terminal and allowing for reliable detection and prevention of high-temperature supply issues, enabling continued heating operations with user notification.

Implementation Method 1

a mixing device which mixes the hot water to be conveyed from the hot water storage tank to the heating terminal with hot water whose heat has been dissipated at the heating terminal

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a temperature detector provided at a downstream side of the mixing device for detecting a temperature of the hot water circulating between the hot water storage tank and the heating terminal

Methodology Applied
Scientific EffectTemperature detection: Temperature Gradient

Implementation Method 3

a circulating pump which circulates hot water between the hot water storage tank and the heating terminal

Methodology Applied
Scientific EffectFluid circulation: Pump

Data Source

PatentEP3124877B1Hot water heating device
Publication Date: 2018.11.28 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3124877B1 patent drawingFigure 1~2

AI summary

A hot water heating device according to the present disclosure includes a heat source machine, a hot water storage tank, a heating terminal, a circulating pump which circulates hot water between the hot water storage tank and the heating terminal, a mixing device which mixes the hot water to be conveyed from the hot water storage tank to the heating terminal with the hot water whose heat has been dissipated at the heating terminal, a temperature detector provided at a downstream side of the mixing device for detecting a temperature of the hot water circulating between the hot water storage tank and the heating terminal, and a control device. When the temperature detector detects a predetermined temperature or above, the control device stops driving of the circulating pump. This enables improvement in heat exchange efficiency as well as improvement in safety.