On High Efficient Heating Pipes

The Improvement of Heat Transfer by Inserting Spiral Blades

Abstract

In the heat exchanger, it is important to improve the efficiency of heat transfer. The aim of this paper is to compare the efficiency of heating pipes by changing the shape of spiral blades; the pitch and Roynolds number. In addition, the flow in heating pipes is visualized.
Experimental results have revealed that the efficiency of pipes with blades increases
1) under 3 000 in Reynolds numbers,
2) under 5 in aspect ratios, and
3) by twisting blades left and right alternatively.