Bell-Mouth Rectifier Layout for Ceiling Airflow Swirl Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ceiling-embedded air conditioners suffer from reduced heat-exchange efficiency due to swirling airflows generated at the back surface of the bell-mouth, leading to air retention and uneven wind speed distribution, which existing solutions like radial ribs do not effectively address, and may introduce noise and vibration issues.
Innovation Solution
The implementation of rectifiers on the back surface of the bell-mouth, which are erected vertically and extended horizontally to suppress swirling airflows, forcing them towards the heat exchanger and preventing air retention, while also serving as reinforcement to enhance structural strength and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If radial ribs are provided on the back surface of the shroud to suppress air loss, then air blow loss is reduced, but wind noise and vibration increase
Solution Approach 1:
A guide vane is introduced as an intermediary component between the bell-mouth and the shroud. The guide vane redirects the swirling airflow along its surface toward the heat exchanger, preventing direct contact with the shroud back surface while maintaining airflow control. This mediator structure achieves air flow suppression without the noise and vibration problems of radial ribs.
2Length of moving object
If the axial height of the outlet is set lower than the height of the heat exchanger, then the blowing range in the axial direction is reduced, but this causes uneven wind speed distribution and unbalanced heat exchange
Solution Approach 1:
The guide vane is positioned specifically at the back surface of the bell-mouth where swirling airflow occurs. It provides localized flow control exactly where needed, redirecting air along its surface toward the heat exchanger. This local intervention corrects wind speed distribution uniformity without requiring changes to the overall outlet height or blowing range.
3Device complexity
If no rectifier is provided on the back surface of the bell-mouth, then the structure is simple, but swirling airflows are generated that reduce heat-exchange efficiency
Solution Approach 1:
The guide vane serves as a simple intermediary structure that intercepts swirling airflow at the bell-mouth back surface and redirects it toward the heat exchanger. This single component effectively suppresses swirling airflows and improves heat-exchange efficiency without adding complex mechanisms, maintaining structural simplicity while solving the energy loss problem.
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 effectively suppresses swirling airflows, enhances heat-exchange efficiency, and reduces air recirculation, leading to improved airflow distribution and increased heat transfer effectiveness without increasing noise or vibration.
Implementation Method 1
swirling airflows generated on the back surface of a bell-mouth by rotation of a turbo fan
Implementation Method 2
The air blown from the turbo fan is directed to the surrounding heat exchanger, and is heat-exchanged with a refrigerant through the spaces between heat-radiation fins in the heat exchanger
Implementation Method 3
air blown from the turbo fan is directed to the surrounding heat exchanger, and is heat-exchanged with a refrigerant
Implementation Method 4
heat-exchanged with a refrigerant through the spaces between heat-radiation fins
Data Source
Figure 1~2
Figure 3
Figure 4A~4B
AI summary
A ceiling-embedded air conditioner includes: a ceiling-embedded casing body that has an air suction path at the center of a lower surface and has an air blowoff path around the air suction path; a turbo fan that is disposed inside the casing body; a heat exchanger that is disposed inside the casing body on an outer peripheral side of the turbo fan; a bell-mouth that guides air sucked from the air suction path toward the inside of the turbo fan; and a rectifier that is provided on a back surface side of the bell-mouth at the air suction path side opposite to an air suction surface of the bell-mouth, the rectifier suppressing swirling airflows generated by part of air blown from the turbo fan swirling along the back surface of the bell-mouth in the same direction as a rotation direction of the turbo fan.