Indoor AC Blade Angle Control for Stable Coanda Airflow
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Solution Overview
Problem
Air conditioning indoor units using Coanda blades and horizontal blades face challenges in maintaining stable airflow states, with specific angular ranges leading to unstable airflow due to the Coanda effect, and existing solutions fail to effectively manage these transitions.
Innovation Solution
The air conditioning indoor unit incorporates a control system that adjusts the relative angle between the Coanda blade and the horizontal blade to predetermined angles in distinct angular ranges, allowing for selective use of airflow states that either utilize or do not utilize the Coanda effect, thereby stabilizing airflow in both modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the relative angle between the Coanda blade and the horizontal blade is adjusted to utilize the Coanda effect, then the airflow direction control is improved, but the airflow stability deteriorates in certain angular ranges
Solution Approach 1:
The patent applies parameter changes by defining specific angular ranges for the relative angle between the Coanda blade and horizontal blade. The control unit adjusts the relative angle to fall within a first angular range (where Coanda airflow is produced on substantially the entire region of the undersurface) or a second angular range (where Coanda airflow is not produced), thereby avoiding a third angular range that causes unstable airflow. This parameter-based control resolves the contradiction by enabling direction control through angle adjustment while maintaining stability by excluding unstable angular ranges.
2Area of stationary object
If the angular range for Coanda airflow production is increased, then the airflow coverage area is improved, but the airflow stability deteriorates
Solution Approach 1:
The patent resolves this contradiction by precisely defining the first angular range to ensure Coanda airflow is produced on substantially the entire region of the Coanda blade undersurface, maximizing coverage area. Simultaneously, the control unit excludes the third angular range that causes instability, thereby achieving both wide coverage and stable airflow through optimized parameter selection.
3Stability of the object's composition
If the relative angle is adjusted to produce Coanda airflow on the entire undersurface, then the airflow uniformity is improved, but the device complexity increases
Solution Approach 1:
The patent achieves uniform Coanda airflow across the entire undersurface by controlling the relative angle to fall within the first angular range, where the airflow state is characterized by production of Coanda airflow on substantially the entire region. The control unit implements this through parameter-based angle adjustment, which maintains airflow uniformity while avoiding the need for complex additional mechanisms.
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 solution ensures stable airflow in both Coanda airflow and non-Coanda airflow states by excluding unstable angular ranges and optimizing blade positions, reducing concerns of airflow instability and ensuring consistent air direction control.
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
Data Source
AI summary
An air conditioning indoor unit includes a casing having an air outlet, a horizontal blade that changes an up and down direction flow of outlet air, a Coanda blade to change the outlet air to a Coanda airflow along an undersurface of the Coanda blade, and a control unit. The control unit adjusts a relative angle between the Coanda blade and the horizontal blade to selectively use either of a first airflow state and a second airflow state. In the first airflow state, the control unit adjusts the relative angle to a predetermined angle in a first angular range to produce the Coanda airflow on substantially an entire region of the undersurface of the Coanda blade. In the second airflow state, the control unit 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.