**Greek symbols**

of the new heat transfer correlation. It is clearly seen from **Table 5** that the new correlation has a mean absolute deviation of 9.23%, and 78.57% of the predicted results fall into the 10% error band, and 95.18% of the predicted results fall into the 20% error band, and 99.39% of the predicted results fall into the 30% error band, indicating that the prediction accuracy of the new correlation is better than that of

1.Comprehensive reviews of experimental data of heat transfer of SCW and heat transfer correlations for SCW are conducted in this study. Totally, 250

2.About 34 heat transfer correlations for SCW are evaluated. It is found that remarkable discrepancies exist among the results predicted by different correlations, and there is no correlation which could give satisfactory

3.A new heat transfer correlation is proposed for heat transfer of SCW flowing in vertically upward tubes under both DHT and EHT regimes, and the prediction performance of the new correlation is better than that of other correlations when both the DHT and EHT regimes are considered at the same

The authors acknowledge the support of the National Basic Research Program of

Pr<sup>0</sup>*:*<sup>5</sup>

ð Þ *<sup>ρ</sup><sup>b</sup>* � *<sup>ρ</sup> <sup>ρ</sup>b=v*<sup>2</sup>

*b*

prediction accuracy under different heat transfer conditions.

experimental cases and 12,704 data points about heat transfer of SCW are collected.

the existing heat transfer correlations.

*Advanced Supercritical Fluids Technologies*

**5. Conclusions**

time.

**Acknowledgements**

**Conflict of interest**

**Appendices and Nomenclature**

*C* constant indices

Gr Grashof number

*h* enthalpy, J/kg *k* constant indices

**58**

*d* inner tube diameter, m *f* friction coefficient

*g* acceleration due to gravity, m/s<sup>2</sup>

*Kv* acceleration correction factor

China (973 Program, Grant No. 2015CB251502).

The authors declared that there is on conflict of interest.

Bu buoyance correction factor, Bu <sup>¼</sup> Gr*<sup>=</sup>* Re <sup>2</sup>*:*<sup>7</sup>

*C*<sup>p</sup> specific heat at constant pressure, J/(kg�K)

Gr\* acceleration correction factor, *βgD*<sup>4</sup>*qw=λν*<sup>2</sup> Gr average Grashof number, Grb <sup>¼</sup> *gd*<sup>3</sup>

*C*<sup>p</sup> average specific heat, ð Þ *hw* � *hb =*ð Þ *Tw* � *Tb* , J/(kg�K)

