| Abstract: | Forced convection heat transfer of single-phase water in helical coils was experimentally studied. The testing section was
constructed from a stainless steel round tube with an inner diameter of 10 mm, coil diameter of 300 mm, and pitch of 50 mm.
The experiments were conducted over a wide Reynolds number range of 40000 to 500000. Both constant-property flows at normal
pressure and variable-property flows at supercritical pressure were investigated. The contribution of secondary flow in the
helical coil to heat transfer was gradually suppressed with increasing Reynolds number. Hence, heat transfer coefficients
of the helical tube were close to those of the straight tube under the same flow conditions when the Reynolds number is large
enough. Based on the experimental data, heat transfer correlations for both incompressible flows and supercritical fluid flows
through helical coils were proposed. |
