Experimental investigation on heat transfer enhancement with spiral springs with the square cross-section area inserts

The purpose of this study is to investigate the effect of spiral springs with the square cross-section area on heat transfer in heat exchangers. The experiments were conducted using the Spiral springs with square cross-section. The springs are mounted inside a copper tube with a circular cross-section. The diameter and length of the copper tube are 24.2 mm and 1820 mm, respectively. The experiments were performed with 3 spiral springs of 21 mm diameter in three pitches 10, 20 and 30. The fluid used in these experiments is water and the Reynolds number for the hot water flow into the copper tube at the range of 22462 to 36456.1.The results show that, after the springs was placed inside the copper tube, the heat transfer coefficient is increased by 45% relative to the non -spring condition. However, the pressure drop in the worst case was increased by 70%. It can also be seen that the heat transfer coefficient increases to 30%.

کلیدواژه ها:

Heat exchanger ، Heat transfer ، Pressure drop ، Spiral spring ، thermal performance factor