How to efficiently transfer heat in microchannel flat tubes
Information summary:The microchannel flat tube achieves efficient heat transfer through special structure and flow optimization, with the following key points:
1、 Heat transfer principle
Small size advantage: The channel diameter is 0.5-3mm, and the heat transfer area per unit volume is 5-10 times that of traditional circular pipes. The fluid is prone to turbulence, which can damage the thermal resistance bou
The microchannel flat tube achieves efficient heat transfer through special structure and flow optimization, with the following key points:
1、 Heat transfer principle
Small size advantage: The channel diameter is 0.5-3mm, and the heat transfer area per unit volume is 5-10 times that of traditional circular pipes. The fluid is prone to turbulence, which can damage the thermal resistance boundary layer.
Phase change enhancement: When the refrigerant (such as R32) in the flat tube undergoes phase change, the liquid film becomes thin and the gas-liquid layer flows, reducing local overheating and improving evaporation/condensation efficiency.
2、 Key design
1. Structural parameters:
Multi channel (10-100 parallel channels), flat aspect ratio of 5:1~20:1, increasing heat dissipation area.
Thin walls (0.2~0.5mm) reduce thermal resistance, while non-circular cross-sections (trapezoidal/rectangular) enhance eddy currents.
2. Surface technology:
Adding disturbance to the inner wall micro fins/grooves increases the heat transfer coefficient by 20% to 30%.
The porous coating promotes the generation of boiling bubbles and increases the critical heat flux density by 50%.
3. Flow optimization:
The inlet distributor ensures uniform flow, and the variable cross-section design adjusts the flow rate. The large curvature of the curved section reduces pressure drop.
3、 Challenge and Improvement
1. High resistance: Gradient channels/drag reducing coatings reduce pressure drop by 20% to 30%.
2. Manufacturing difficulty: Laser microfabrication can produce sub millimeter level channels (accuracy ± 5 μ m).
3. Easy to clog: high-precision filtration+self-cleaning surface reduces impurity deposition.
Summary: Microchannel flat tubes have become the core solution for compact and efficient heat dissipation due to their high surface to volume ratio, multi-channel structure, and flow enhancement technology. They are widely used in the fields of new energy, refrigeration, and electronics.