Heat Exchanger Fin Portions Stabilize Vortex Flow
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Solution Overview
Problem
Heat exchangers in refrigeration cycle apparatuses face a reduction in heat exchange capacity due to attenuation of vortex flows as they pass through spaces between heat transfer parts, such as flat tubes.
Innovation Solution
The heat exchanger design incorporates fin portions that extend towards the vortex generator, creating uniform air passages and reducing vortex flow attenuation by providing wider inlets for air, thus stabilizing airflow and minimizing collisions with the heat exchanger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If vortex flows are generated to improve heat transfer performance, then heat exchange capacity is enhanced, but vortex flows are attenuated when passing through spaces between heat transfer parts
Solution Approach 1:
The patent applies local quality by providing fin portions at specific locations (upstream ends) of heat transfer parts that extend toward the vortex generator. These fin portions create localized wide inlets in the air passages where vortex flows are most vulnerable to attenuation, while maintaining the original structure in other regions. This targeted modification stabilizes vortex flows without requiring complete redesign of the entire heat exchanger structure.
Solution Approach 2:
The fin portions extend in the air flow direction (third direction) from the heat transfer tubes, creating a three-dimensional structure that modifies the two-dimensional air passage geometry. This dimensional addition creates wide inlets that reduce vortex flow attenuation while maintaining compact heat exchanger overall dimensions.
2Productivity
If heat transfer area is increased to improve heat exchange performance, then heat transfer efficiency is enhanced, but device complexity increases
Solution Approach 1:
The fin portions are integrated with the heat transfer tubes to form a unified heat transfer part structure. This merging approach increases the heat transfer area by adding fin surfaces while avoiding the complexity of separate, independently mounted components. The fin portions and heat transfer tubes work together as a single functional unit.
3Productivity
If air passages are made longer to accommodate more heat transfer parts, then heat exchange capacity increases, but vortex flow attenuation worsens
Solution Approach 1:
Rather than uniformly modifying all air passages, the patent applies fin portions selectively at strategic locations where wide inlets are most effective in maintaining vortex flows. This localized approach allows longer air passages to accommodate more heat transfer parts while preventing vortex attenuation at critical entry points into each heat transfer part.
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 enhances heat transfer performance by maintaining the stability of vortex flows, increasing the heat transfer area, and reducing attenuation, leading to improved heat exchange efficiency.
Implementation Method 1
The vortex generator generates vortex flows from air flowing into the heat exchangers
Implementation Method 2
change the flow of air traveling into a heat exchanger from laminar flows to vortex flows (turbulent flows)
Implementation Method 3
an evaporator including heat transfer tubes through which refrigerant flows, and heat transfer fins connected to the heat transfer tubes
Implementation Method 4
the evaporator being configured to cool air with the refrigerant
Data Source
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AI summary
A heat-exchanger unit and a refrigeration cycle apparatus are to be provided that are each configured to reduce attenuation of vortex flows of air that occurs when the air passes through spaces between heat transfer parts of a heat exchanger. The heat-exchanger unit and the refrigeration cycle apparatus each include the heat exchanger, a fan configured to supply air to the heat exchanger, and a vortex generator located upstream of the heat exchanger in a direction in which the air flows and configured to generate a vortex flow of the air. The heat exchanger is provided with a plurality of heat transfer parts that are arranged at intervals in a first direction. The plurality of heat transfer parts are each provided with a refrigerant passage portion through which refrigerant flows inside the refrigerant passage portion in a second direction that intersects the first direction, and a fin portion that extends from the refrigerant passage portion toward the vortex generator. Where a virtual line passes through a center of a width of the refrigerant passage portion in the first direction and extends in a third direction that is orthogonal to the first direction and the second direction, the fin portion overlaps with the virtual line in position.