Heat Exchanger Fin Spacing via Segmented Spacer Design
Solution Overview
Problem
Existing heat exchanger designs face issues with reduced heat exchange performance, increased ventilation resistance, and clogged air passages due to insufficient spacers maintaining the interval between fins, especially under low-temperature conditions where frost forms, leading to poor drainage and ventilation properties.
Innovation Solution
A heat exchanger configuration featuring a first spacer at the rim of the insertion portion and a second spacer on the plate surface, positioned upwind and downwind respectively, to maintain an appropriate interval between fins, enhancing drainage and ventilation while preventing frost buildup and maintaining heat exchange performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single spacer is formed at the rim of the insertion portion to maintain the interval between fins, then the structure is simple and easy to manufacture, but the standing portion is short and heat exchange performance is reduced
Solution Approach 1:
The spacer is divided into two distinct parts: a first spacer formed at the rim of the insertion portion and a second spacer formed on the plate surface at a position away from the rim. This segmentation allows each spacer to perform its specific function - the first spacer maintains the interval between fins while the second spacer ensures proper drainage path, thereby resolving the contradiction between manufacturing simplicity and heat exchange performance.
Solution Approach 2:
Different portions of the fin structure are given different functions: the rim portion (first spacer) is optimized for maintaining fin interval and structural support, while the plate surface portion (second spacer) is optimized for drainage function. This local differentiation of quality and function allows the system to achieve both manufacturing ease and high heat exchange performance.
2Length of stationary object
If a spacer is disposed in the air passage between fins to maintain the interval, then the fin interval is maintained, but ventilation resistance increases and air passage becomes clogged during low-temperature operation
Solution Approach 1:
The second spacer is strategically positioned on the plate surface away from the rim, creating a localized drainage structure that does not obstruct the main air passage. This local placement ensures the spacer maintains the fin interval while minimizing interference with air flow, thereby reducing ventilation resistance during low-temperature operation.
Solution Approach 2:
The second spacer acts as an intermediary element that provides a drainage path for condensation water or meltwater without directly blocking the air passage. By creating this intermediate drainage structure, the system maintains proper fin interval while allowing air to flow freely, thus resolving the contradiction between interval maintenance and ventilation resistance.
3Length of stationary object
If the standing portion is short to maintain fin interval, then the fin spacing is controlled, but drainage properties are poor and heat exchange performance deteriorates
Solution Approach 1:
The drainage function is separated from the fin interval maintenance function by creating a distinct second spacer on the plate surface. This segmentation allows the first spacer to focus on maintaining the fin interval while the second spacer is specifically designed to provide adequate drainage path length, thereby ensuring both proper fin spacing and reliable drainage properties.
Solution Approach 2:
The second spacer serves as an intermediary drainage structure that collects and channels condensation water or meltwater away from the heat exchange surface. This intermediate drainage path prevents water accumulation that would otherwise deteriorate heat exchange performance, while maintaining the required fin interval through the first spacer.
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 effectively prevents air passage clogging, ensures proper drainage during defrosting, and maintains heat exchange performance by reducing ventilation resistance and frost formation, thereby enhancing the heat exchanger's defrosting and heat exchange capabilities.
Implementation Method 1
the first spacer is in contact with a next fin
Implementation Method 2
the second spacer is in contact with a next fin
Implementation Method 3
heat is exchanged between air passing through between the fins and fluid flowing through the flat tubes
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus are provided where deterioration in drainage properties and ventilation properties is prevented, an air passage is not easily clogged when frost forms, and both defrosting properties and heat exchange performance are achieved. A flat tube and a plurality of fins that are each a plate having a plate surface extending in a longitudinal direction and in a width direction orthogonal to the longitudinal direction are provided. The plate surface intersects a pipe axis of the flat tube. The plurality of fins are arranged at an interval from one another. The plurality of fins each have an insertion portion in which the flat tube is inserted, a first spacer formed at a rim of the insertion portion and maintaining the interval, and a second spacer formed at a portion of the plate other than the rim of the insertion portion and maintaining the interval. The first spacer is positioned at one end portion in a longitudinal direction of a section of the rim of the insertion portion, and the section is perpendicular to the pipe axis of the flat tube.