Air conditioner

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Solution Overview

Problem

Air-conditioning devices with a thin shape in the height direction face issues such as unstable fan output flow, increased air flow resistance, and backflow due to dust and condensation, leading to condensation on the fan and potential scattering into the room, especially during cooling.

Innovation Solution

The air-conditioning device is designed with a cuboid-shaped main body where the depth dimension is greater than the height dimension, featuring a cross-flow fan, a heat exchanger with a specific inclination angle, and a stabilizer to guide air flow, ensuring the fan and heat exchanger are positioned to prevent backflow by optimizing the ratio of height to fan diameter and inclination angles, and using a diffuser to manage air flow and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the main body is formed in a thin shape with depth dimension greater than height dimension, then the installation surface area on wall surface is reduced and aesthetic appearance is improved, but the fan inlet region becomes small and air flow resistance increases

Engineering Contradiction:
Improveinstallation surface areaVSAvoidair flow stability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent reorients the heat exchanger from a horizontal arrangement to an inclined arrangement at angles of 30-60 degrees relative to the vertical direction. This dimensional change in the heat exchanger's orientation allows the fan inlet region to be positioned more effectively, increasing the distance between the fan and heat exchanger while maintaining the thin profile of the main body. The inclined configuration optimizes air flow paths without requiring additional horizontal space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent specifies precise parameter ranges: the inclination angle of the heat exchanger is set to 30-60 degrees, and the distance between the fan and heat exchanger is maintained at 20-50mm. These parameter optimizations ensure sufficient air flow resistance reduction while maintaining the compact thin-shape design, preventing back flow even when the depth dimension is greater than the height dimension.

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If the fan and heat exchanger are positioned close together to save space, then the device can maintain a thin profile, but air flow resistance increases and back flow occurs

Engineering Contradiction:
Improvedistance between fan and heat exchangerVSAvoidback flow and condensation
Core Design Contradiction:
Length of stationary objectVSObject-generated harmful factors

Solution Approach 1:

Instead of increasing the horizontal distance between the fan and heat exchanger (which would increase the overall device depth), the patent inclines the heat exchanger at 30-60 degrees relative to the vertical direction. This creates effective vertical and diagonal spacing that increases the air flow path length and reduces resistance without proportionally increasing the horizontal footprint, thus preventing back flow while maintaining a thin profile.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent introduces a stabilizer as an intermediary component positioned between the fan and heat exchanger. This stabilizer has a front surface that faces the fan and a rear surface that faces the heat exchanger, creating a structured air flow channel. The stabilizer acts as a mediator that guides air flow smoothly from the fan inlet through the heat exchanger, preventing turbulence and back flow that would occur in direct close proximity arrangements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the heat exchanger is positioned horizontally to simplify installation, then manufacturing is easier, but condensation drips onto the fan during cooling operation

Engineering Contradiction:
Improveheat exchanger installationVSAvoidcondensation on fan
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the orientation of the heat exchanger from horizontal to inclined, positioning it at 30-60 degrees relative to the vertical direction. This angular reconfiguration ensures that condensation formed on the heat exchanger surfaces during cooling operation drains downward away from the fan, preventing water accumulation and subsequent dripping onto the fan blades, while still allowing for relatively simple installation procedures.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 stabilizes air flow, reduces backflow, and enhances energy efficiency while preventing condensation on the fan, resulting in a high-quality air-conditioning device with improved performance and reduced noise.

Implementation Method 1

a heat exchanger (7) which cools down air taken in from the inlet port or heats the air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a cross-flow fan (8) which blows the air taken in from the inlet port, towards the outlet port

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP3214378B1Air conditioner
Publication Date: 2021.04.21 MITSUBISHI ELECTRIC CORP
  • EP3214378B1 patent drawingFigure 1
  • EP3214378B1 patent drawingFigure 2~3
  • EP3214378B1 patent drawingFigure 4~6

AI summary

In an air-conditioning device 100, back flow is less likely to occur at an outlet port in relation to an inlet resistance, and the air-conditioning device 100 includes: a main body 1 having an inlet port 2b and an outlet port 3; a cross-flow fan 8 provided inside the main body; and a heat exchanger 7 provided inside the main body 1, wherein the main body 1 includes at least a front surface 1a, a rear surface 1c, an upper surface 1b and a lower surface 1d, the inlet port 2b is formed in the upper surface 1b, a ratio H/Df between the main body height dimension H and the fan outer diameter Df is 2.2 to 2.7, and an angle of inclination β between a rear part of an front upward inclination section 7a' of the heat exchanger 7 and a vertical direction is 30° to 45°.