Cross-Flow Fan and Heat Exchanger Layout for Lower AC Fan Power
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Solution Overview
Problem
Conventional air conditioners require high input power and revolution speed of the fan motor to achieve a predetermined airflow due to suboptimal blade shapes and heat exchanger arrangements, leading to inefficient airflow and increased energy consumption.
Innovation Solution
The air conditioner design includes a cross-flow fan with a front heat exchanger installed at an angle of 65° to 90° relative to the horizon and a back heat exchanger positioned adjacent to the front heat exchanger, along with a blade outlet angle of 22° to 28°, optimizing airflow direction and reducing fan motor input power and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the blade shapes of the cross-flow fan are changed without changing the arrangement of the heat exchangers, then the aerodynamic characteristics are improved, but the input power and revolution speed of the fan motor remain large
Solution Approach 1:
The patent applies parameter changes by optimizing both the blade outlet angle (20° to 30°) and the heat exchanger installation angle (45° to 90°) simultaneously. This dual parameter optimization resolves the contradiction by achieving improved aerodynamic characteristics while reducing fan motor input power, as the coordinated angles create optimal airflow patterns that reduce resistance and improve efficiency.
2Productivity
If the blade outlet angle is increased to reduce gushing in the delivery region, then the airflow performance is improved, but the input power of the fan motor increases
Solution Approach 1:
The patent identifies an optimal blade outlet angle range of 20° to 30° that balances airflow performance with power consumption. Within this range, the blade geometry is optimized to deliver sufficient airflow while minimizing the input power required, resolving the contradiction between airflow performance and power consumption through precise parameter selection.
3Productivity
If the heat exchanger installation angle is increased to improve heat transfer performance, then the heat transfer efficiency is improved, but the airflow resistance increases
Solution Approach 1:
The patent optimizes the heat exchanger installation angle within the range of 45° to 90° to achieve the best balance between heat transfer efficiency and airflow resistance. This parameter optimization ensures that the heat exchanger is positioned at an angle that maximizes heat transfer while minimizing the resistance to airflow, resolving the contradiction between these two performance criteria.
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 reduces the input power and rotational speed of the fan motor necessary for achieving a predetermined airflow, enhancing energy efficiency and airflow performance.
Implementation Method 1
a cross-flow fan (1) connected to a fan motor
Implementation Method 2
a front heat exchanger (2) and a back heat exchanger (3)
Data Source
AI summary
To provide an air conditioner capable of reducing an input power and a rotational speed of a fan motor necessary for obtaining a predetermined flow rate from an indoor unit. An air conditioner includes an indoor unit 8 having at least one inlet 6 and one outlet 8; a cross-flow fan 1 connected to a fan motor; a front heat exchanger 2; and a back heat exchanger 3, wherein an installation angle α of the front heat exchanger 2 positioned above the rotational center of the cross-flow fan 1 relative to the horizon is 65°≦α≦90°, a point of the back heat exchanger 3 closest to the front heat exchanger 2 is located adjacent to the front heat exchanger 2 from the rotational center of the cross-flow fan 1, and an outlet angle β2 of a blade of the cross-flow fan 1 is 22°≦β2≦28°.