Outdoor Unit Leg Structure to Prevent Drainage Freezing

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Solution Overview

Problem

Water flowing from a heat exchanger in an outdoor air conditioner unit can freeze when in contact with metal installation legs, causing drainage channel blockages and reducing drainage performance, especially in low temperatures.

Innovation Solution

The heat exchanger is mounted on the installation leg, which transfers heat to the leg, preventing water from freezing, and the leg features drainage holes and a corrugated bottom plate design with gaps and channels to facilitate water drainage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water flows through a drainage channel formed above a support portion of an installation leg, then drainage function is provided, but water may be frozen when outside air temperature is below freezing point, closing the drainage channel and decreasing drainage performance

Engineering Contradiction:
Improvedrainage performanceVSAvoidfreezing of water
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an insulating member as an intermediary substance between the drainage channel and the metal installation leg. This insulating member prevents direct thermal conduction from the cold leg to the water in the drainage channel, thereby preventing freezing while maintaining the drainage function. The insulating member acts as a thermal barrier that mediates the heat transfer between the cold leg and the water.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful effect of the metal installation leg (which conducts heat away from water causing freezing) into a beneficial effect by covering it with an insulating material. The same structural element that causes the problem (the metal leg providing structural support) is transformed into a solution by adding insulation, which prevents heat loss while maintaining the structural function.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Strength

If the installation leg is made of metal to provide structural support, then mechanical strength is ensured, but heat conduction causes water to freeze in cold conditions

Engineering Contradiction:
Improvestructural support strengthVSAvoidheat loss from drainage channel
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent creates a composite structure by combining the metal installation leg (for structural strength) with an insulating material (for thermal insulation). This composite construction allows the system to simultaneously achieve mechanical strength from the metal component and thermal insulation from the insulating material, preventing heat loss without sacrificing structural support capability.

Inventive Principle:
Principle #40Composite materials

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 that water from the heat exchanger is not frozen and is effectively drained, enhancing the drainage performance of the outdoor unit even in low temperatures.

Implementation Method 1

heat of the heat exchanger (10) is transferred to the installation leg (30) and heats the installation leg (30)

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3730851B1Outdoor unit for air conditioner
Publication Date: 2022.03.02 DAIKIN INDUSTRIES LTD
  • EP3730851B1 patent drawingFigure 1
  • EP3730851B1 patent drawingFigure 2
  • EP3730851B1 patent drawingFigure 3

AI summary

An outdoor unit (1) includes a bottom plate (22) that defines a bottom surface of a casing (20); and an installation leg (30) that supports the bottom plate (22) from below. The installation leg (30) has a drainage hole (35a) that extends through the installation leg (30) in an up-down direction. A mount surface of the installation leg (30) for the heat exchanger (10) is substantially flush with an upper surface of the bottom plate (22). The heat exchanger (10) is mounted to extend from the bottom plate (22) to the installation leg (30).