Cooling of advanced steam turbine blades with boiling liquids

Abstract

Abstract A design solution has been developed and proposed for cooling the nozzle blades of the first stage of a steam turbine operating at steam parameters above standard supercritical conditions. In this work, a capillary-porous system is proposed, functioning on the principle of a closed evaporation–condensation scheme. A diagram of the cooling system is provided. The calculation of the evaporative and condensation parts has been performed. A model of vapor bubble contact with the vapor-generating surface within the vapor generation cells of the capillary-porous structure is presented. Experimental installations for optical research methods of the dynamics of vapor and liquid phase development have been created. Visual observations of the processes are carried out using high-speed filming with an HSMC-1 M camera; photo and filming are performed using «Zenit», «RPC-5 M» cameras, as well as «Krasnogorsk» and «Kiev-16 s» movie cameras. To study vaporization processes using holographic interferometry, an interferometer was employed, incorporating a helium–neon laser of the LG-38 type. The initial stage of vapor bubble nucleation and the dynamics of growth and destruction processes in the capillary-porous structure have been investigated using optical methods, with nine stages of development and destruction presented. Cinegrams and holographic interferograms of heat and mass transfer processes are shown for various structures, heat loads, and coolant excess ratios, including calculations of vaporization center density, liquid droplet (water) ejection from the structure, and cavity formation due to erosion.