摘要：Flat horizontal spiral-tube is an ideal sort of heat exchangers applicable in solar ponds as it is placed in the hottest zone (bottom of the pond) with the maximum coverage area to transfer the heat into the secondary fluid flow. Due to the curve nature of the flat spiral-tube, most types of turbulators, useable for straight tubes, are not applicable for spiral-tube. However, this paper shows how spring-wire can be employed as a turbulator for spiral-tube to enhance its thermal characteristics including Nu number and thermal performance. It is noted that, for a given spiral tube length, turbulator will increase the heat transfer rate. From another viewpoint, for a given expected heat transfer rate, the turbulator will reduce the required size/length of the spiral tube (which means lower material/weight and cost). Spring-wire with different geometries are utilized as the turbulator for spiral tube in this research to identify its thermal, frictional and performance features. It is noted that, spring-wire should be inserted into the spiral tube through its fabrication process prior to the rolling step (when it is still straight tube). Interesting results were obtained which are reported and discussed in this paper.
