In this paper

RNG k-ε model is used to simulate the heat transfer of a double-pipe heat exchanger enhanced by helical fins. The simulation results are verified with experimental results. With the Reynolds number from 2362 to 16860

the effect of helix angle α on the Nusselt number and frictional resistance coefficient f are analyzed. The change of performance evaluation criteria(PEC) value and the comprehensive heat transfer performance at the same pump power are examined. The average error of Nu and f are 7.1% and 1.3%

respectively

indicating that the method used is appropriate. For α from 15° to 75°

both Nu and f increase as α decreases. In particular

for α values less than 35°

f increases dramatically as α decreases. With the same pump power

the value of PEC varies from 0.84 to 1.93. In the α range from 15° to 45°

the comprehensive heat transfer performance is better with 35°. Although the PEC values with α of 55°

65° and 75° are slightly higher than that of 35°

Nu is much smaller. Considering the rate of heat transfer in applications

helix angle of 35° is more appropriate

with PEC of 1.26—1.62. Besides

it is proposed to use oblique helical fins to reduce the value of f. Compared with double-pipe heat exchanger enhanced by common helical fins

the Nu value of that enhanced by oblique helical fins with α of 35° and β of 10° is a little higher

f is reduced by 12.5%—14.5%

and PEC varies from 1.38—1.71. The field synergy principle also verifies the result.