Bowstring Heat Exchanger Pipes for Uniform Flow and Reduced Pressure Loss
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Solution Overview
Problem
Existing heat exchangers and oxygenators used in extracorporeal blood circulation lack improved flow and heat transfer characteristics, which are essential for efficient carbon dioxide removal, oxygen addition, and temperature adjustment during blood processing.
Innovation Solution
A multipipe heat exchanger with a unique configuration, including tapered inner surfaces and bowstring-shaped portions for heat transfer pipes, and an integrated oxygenator design with specific port placements and gas exchange mechanisms, ensures uniform heat exchange medium flow and efficient gas exchange between blood and oxygen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional heat exchanger configuration is used, then structure is simple, but flow and heat transfer characteristics are insufficient
Solution Approach 1:
The patent applies curvature by forming the heat transfer pipes in a bowstring-shaped configuration rather than straight lines. This curved geometry creates favorable flow patterns and enhances heat transfer characteristics between the blood and heat exchange medium, directly improving heat exchange performance while maintaining reasonable structural complexity.
Solution Approach 2:
The patent implements local quality by creating a tapered inner surface configuration in the heat exchanger case, where the distance between the tapered surface and the bowstring-shaped heat transfer pipes varies along the flow direction. This non-uniform spacing optimizes flow distribution and heat transfer efficiency at different locations, enhancing overall heat exchange performance without uniformly increasing structural complexity throughout the entire device.
2Temperature
If heat exchange efficiency is improved, then temperature adjustment capability increases, but pressure loss increases
Solution Approach 1:
The bowstring-shaped curved configuration of heat transfer pipes promotes smoother flow transitions and reduces flow separation compared to straight pipe arrangements. This curvature design enhances heat transfer efficiency for blood temperature adjustment while simultaneously reducing pressure loss by maintaining more favorable flow patterns throughout the heat exchanger.
Solution Approach 2:
The patent employs parameter changes by varying the spacing between the tapered inner surface and the bowstring-shaped heat transfer pipes along the flow direction. This gradual parameter variation optimizes the balance between heat transfer efficiency (for temperature adjustment) and pressure loss, creating conditions that enhance thermal exchange while minimizing flow resistance.
3Volume of stationary object
If heat transfer pipes are positioned closer to inner surface for compactness, then device volume decreases, but flow distribution becomes non-uniform
Solution Approach 1:
The tapered inner surface configuration creates location-dependent spacing between the heat exchanger case and the bowstring-shaped heat transfer pipes. This local variation in spacing ensures that even though the pipes are positioned relatively close to the inner surface for compactness, the flow distribution remains uniform by providing appropriate flow channels at different locations along the heat exchange path.
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
The solution enhances heat exchange performance, reduces pressure loss, and minimizes cell destruction, resulting in improved blood processing efficiency and patient safety by achieving high heat exchange performance and reduced priming volume.
Implementation Method 1
The heat exchange medium inlet port supplies a prescribed heat exchange medium to an outer surface of the heat transfer pipe
Implementation Method 2
The heat exchange medium outlet port discharges the heat exchange medium supplied to the outer surface of the heat transfer pipe
Data Source
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AI summary
A plurality of heat transfer pipes (8) have a circumferential portion (81) arranged at a short distance from an inner surface (72) of a heat exchanger case (70) while they are bundled to form a pipe group (80) and a first bowstring-shaped portion (82) which retracts toward a center in a direction of cylinder diameter from an arc formed by the circumferential portion (81). The plurality of bundled heat transfer pipes (8) are loaded in a cylindrical core (70) such that the first bowstring-shaped portion (82) and an inner surface (72L) of the cylindrical core (70) on a side where a heat exchange medium inlet port (74) is attached are opposed to each other. By making a flow of a heat exchange medium to each heat transfer pipe (8) uniform, a heat exchanger capable of obtaining high heat exchange performance is obtained.