TY - JOUR
TI - Heat transfer on grooved high density poly ethylene tube for surface water source heat pump
AU - Jung Gun Joo
AU - Oh Geun Sug
AU - Chung Chul Woo
AU - Kim Han Ji
JN - Thermal Science
PY - 2014
VL - 18
IS - 4
SP - 1327
EP - 1341
PT - Article
AB - High density polyethylene (HDPE) tube has been successfully utilized in  surface water source heat pump (SWSHP) system as a surface water heat  exchanger (SWHE). Since the heat transfer coefficient (U value) of the HDPE  tube directly affects performance and energy efficiency of SWSHP, this  research aims to increase U value of HDPE tube by grooving external surface  of conventional 32A HDPE tube to reducing cross sectional volume. The final  shape of grooved HDPE tube is similar to that of fin. In order to verify the  performance of grooved HDPE tube, the U values of grooved and smooth tube  were compared experimentally. According to the results, U value of grooved  tube showed approximately 21.5% increase with natural convection and 23.5%  with forced convection system than U values obtained from smooth tube. The  reason for such increase in U value was found to be the reduction in cross  sectional volume of the HDPE tube.