Hot Water Circulation Pump Layout for Stable Pipe Pressure

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Solution Overview

Problem

Existing hot water supply systems experience pressure variations in water distributing pipes due to the location of the circulating pump downstream of the branching point, leading to instability during power interruptions or water supply cutoffs.

Innovation Solution

The circulating pump is positioned upstream of the hot water outlet terminal in the hot water supply pipe, ensuring consistent pressure and preventing water from being drawn from the distributing pipe during supply cutoffs, thus maintaining stable pressure within the water distributing pipe.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the circulating pump is disposed downstream of the branching point in the circulation pipe, then the system structure is simpler, but pressure variation occurs in the water distributing pipe during power interruption or water supply cutoff

Engineering Contradiction:
Improvepump positioning structureVSAvoidpressure stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent inverts the conventional pump positioning by placing the circulating pump upstream of the branching point instead of downstream. This inversion changes the flow direction control mechanism, allowing the pump to prevent water from entering the circulation pipe during supply cutoff, thereby eliminating pressure variation in the water distributing pipe while maintaining system simplicity

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of manufacture

If the circulating pump is disposed downstream of the branching point, then installation is easier, but water is drawn from the water distributing pipe during supply cutoff causing pressure variation

Engineering Contradiction:
Improveinstallation easeVSAvoidpressure variation
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

By inverting the pump position to upstream of the branching point, the system prevents water from being drawn into the circulation pipe during supply cutoff. This inversion eliminates the harmful effect of pressure variation while maintaining ease of installation, as the pump connection points remain straightforward

Inventive Principle:
Principle #13The other way round (Inversion)

3Length of moving object

If the circulating pump is disposed downstream of the branching point, then the circulation path is shorter, but pressure variation occurs during power interruption

Engineering Contradiction:
Improvecirculation path lengthVSAvoidpressure stability
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The patent inverts the pump positioning to upstream of the branching point, which changes the circulation dynamics. Although this may slightly increase the circulation path length, it fundamentally prevents pressure variation during power interruption by blocking the path through which water would otherwise be drawn from the water distributing pipe

Inventive Principle:
Principle #13The other way round (Inversion)

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 configuration ensures reliable instant hot water supply while minimizing pressure variations in the water distributing pipe, even during power outages or water supply interruptions, by applying discharge pressure directly to the outlet terminal.

Implementation Method 1

The circulating pump draws by suction the hot water in the hot water storage tank and discharges the hot water toward the hot water outlet terminal and the circulation pipe

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 2

heat is exchanged between water and a refrigerant, such as carbon dioxide, to generate hot water

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2902714B1Hot-water supply system
Publication Date: 2019.10.23 MITSUBISHI ELECTRIC CORP
  • EP2902714B1 patent drawingFigure 1
  • EP2902714B1 patent drawingFigure 2
  • EP2902714B1 patent drawingFigure 3

AI summary

[Object] To prevent a variation in pressure inside a water distributing pipe while achieving instant hot water supply. [Solution] A hot water supply system includes a hot water storage tank that stores hot water, a hot water supply pipe through which the hot water in the hot water storage tank is supplied to a hot water outlet terminal, a circulation pipe through which the hot water flowing through the hot water supply pipe is returned to the hot water storage tank, and a circulating pump disposed in the hot water supply pipe. The circulation pipe is connected to the hot water supply pipe and the hot water storage tank. The circulating pump is configured to draw by suction the hot water in the hot water storage tank and discharge the hot water toward the hot water outlet terminal and the circulation pipe.