An Experimental Investigation of Heat Transfer Characteristics in a Steam-Cooled Square Channel With Rib Turbulators

In recent years, steam is used in vane internal cooling ducts as a new coolant to replace compressed air. Much research has been carried out into the closed circuit steam cooling for vanes. But most of the existing literatures only provide information on the overall cooling effect of vanes. The effects of steam parameters on the cooling effectiveness of the vane internal channel are still not very clear. A steam heat transfer enhancement test platform of turbine blade (vane) internal channel at Equipment Cooling Technology Laboratory, Xi’an Jiaotong University was built to study the steam cooling characteristics in blade (vane) internal cooling channel. In this paper, heat transfer data of a steam-cooled duct have been experimentally obtained under different operating conditions. The range of key governing parameters is presented as follows: Reynolds numbers based on the channel hydraulic diameter (10000–60000), entry absolute pressures (0.3Mpa–0.6Mpa), heat flux of heat transfer surface area (5.5kWm⁻²−22kWm⁻²), steam superheat (0K–40K). The results show that the average Nusselt numbers along the centerline of the ribbed wall of the steam-cooled square duct are about 15 percent higher than that of air, but the overall heat transfer characteristics of steam in the square duct are similar to that of air under the same conditions.