Indoor Airflow Blade Control for Stable Coanda Air Distribution

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Solution Overview

Problem

Existing air conditioning indoor units using the Coanda effect to guide outlet air face challenges in maintaining stable airflow across varying angular ranges of the Coanda blade and horizontal blade, leading to unstable airflow states.

Innovation Solution

An air conditioning indoor unit with a Coanda blade and horizontal blade that adjusts the relative angle between them to selectively use either a first airflow state producing Coanda airflow on the entire undersurface or a second state not using the Coanda effect, by setting specific angular ranges to exclude unstable third airflow states and ensuring stable airflow in both modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the relative angle between the Coanda blade and horizontal blade is adjusted to produce Coanda airflow, then the airflow guidance capability is improved, but the airflow stability deteriorates in certain angular ranges

Engineering Contradiction:
Improveairflow guidance capabilityVSAvoidairflow stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by identifying and avoiding specific angular ranges (the third angular range) where airflow instability occurs. The control unit adjusts the relative angle between the Coanda blade and horizontal blade to remain within first or second angular ranges, thereby maintaining stable airflow while achieving desired airflow guidance capability through controlled parameter selection.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the angular range of the Coanda blade and horizontal blade is increased to provide more airflow states, then the operational flexibility is improved, but the airflow stability deteriorates due to inclusion of unstable third airflow state

Engineering Contradiction:
Improveoperational flexibilityVSAvoidairflow stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by creating distinct angular ranges (first, second, and third angular ranges) with different airflow characteristics. The control unit selectively operates within specific ranges (first or second) that provide stable airflow, while avoiding the third angular range that produces unstable airflow. This localized control of operational parameters enables flexible airflow direction control while maintaining reliability.

Inventive Principle:
Principle #3Local quality

3Productivity

If the relative angle is adjusted to a predetermined angle in the first angular range, then the Coanda airflow is produced on the entire undersurface of the Coanda blade, but the device complexity increases due to control requirements

Engineering Contradiction:
ImproveCoanda airflow production efficiencyVSAvoidcontrol mechanism complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies self-service by implementing a control unit that automatically monitors and adjusts the relative angle between the Coanda blade and horizontal blade. The control unit independently determines whether to operate in the first or second angular range based on desired airflow requirements, eliminating the need for complex external control systems and simplifying the overall device architecture while maintaining efficient Coanda airflow production.

Inventive Principle:
Principle #25Self-service

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 allows for stable airflow production in both airflow states, reducing concerns of instability and ensuring reliable Coanda airflow utilization or non-utilization, enhancing the unit's operational efficiency.

Implementation Method 1

The Coanda blade cooperates with the horizontal blade to utilize the Coanda effect to change the outlet air to a Coanda airflow along an undersurface of the Coanda blade

Methodology Applied
Scientific EffectCoanda effect: Coanda Effect

Data Source

PatentEP2799790B1Air-conditioning indoor unit
Publication Date: 2016.04.27 DAIKIN INDUSTRIES LTD
  • EP2799790B1 patent drawingFigure 1
  • EP2799790B1 patent drawingFigure 2
  • EP2799790B1 patent drawingFigure 3~4A

AI summary

An air conditioning indoor unit (10) is equipped with: a horizontal blade (31) that changes an up and down direction flow of outlet air; a Coanda blade (32) that cooperates with the horizontal blade (31) to utilize the Coanda effect to change the outlet air to a Coanda airflow along an outside surface (32a) of the Coanda blade (32); and a control unit (40) that can adjust a relative angle between the Coanda blade (32) and the horizontal blade (31) in such a way as to selectively use either of a first airflow state, in which the control unit (40) adjusts the relative angle between the Coanda blade (32) and the horizontal blade (31) to a predetermined angle in a first angular range to produce the Coanda airflow on substantially the entire region of the outside surface (32a) of the Coanda blade (32), and a second airflow state, in which the control unit (40) adjusts the relative angle to a predetermined angle in a second angular range larger than the first angular range to not produce the Coanda airflow.