TY - JOUR N2 - Heating surfaces in power boilers are exposed to very high heat flux. For evaporator protection against overheating, internally helically ribbed tubes are used. The intensification of the heat transfer and the maintenance of the thin water layer in the intercostal space, using ribbed tubes, enables better protection of the power boiler evaporator than smooth pipes. Extended inner surface changes flow and thermal conditions by influencing the linear pressure drop and heat transfer coefficient. This paper presents equations that are used to determine the heat transfer coefficient. The results of total heat transfer, obtained from CFD simulations, for two types of internally ribbed and plain tubes are also presented. L1 - http://journals.pan.pl/Content/85152/PDF/06-paper.pdf L2 - http://journals.pan.pl/Content/85152 PY - 2016 IS - No 2 June EP - 260 DO - 10.1515/cpe-2016-0020 KW - heat transfer coefficient KW - helically internally ribbed tubes KW - power boilers A1 - Majewski, Karol A1 - Grądziel, Sławomir PB - Polish Academy of Sciences Committee of Chemical and Process Engineering VL - vol. 37 DA - 2016 T1 - CFD simulations of heat transfer in internally helically ribbed tubes SP - 251 UR - http://journals.pan.pl/dlibra/publication/edition/85152 T2 - Chemical and Process Engineering ER -