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Experience with the development, study, and manufacturing of cooled blades for the GTÉ-65 high temperature gas turbine is described.The modern, mid-range power, fixed GTÉ-65 gas turbine unit is intended as an electrical generator driver capable of carrying base, semi-peak, and peak loads, either autonomously or in a steam-gas cycle. The GTÉ-65 is a high temperature gas turbine with a mass-mean gas temperature at the turbine inlet of 1368°C. The high initial parameters of the working medium make it necessary to use an advanced system for cooling the turbine blades. The nozzle and working blades in the first stage are equipped with a convective-film cooling system and cooling air input to the vane and onto the outlet edge. The blades in the second and third stages only have convective internal cooling.Design of the cooled blades. Figure 1 shows the cooled blades in the first and second stages of a GTÉ-65. The nozzle blade in the first stage is of the two-cavity type. The leading part of the blade is predominantly film cooled-all the cooling air is discharged through perforation holes. The trailing portion of the blade is primarily cooled convectively -the cooling air is discharged through a slot in the outlet edge.The working blades in the first and second stages are cooled by loop schemes. Since the first working blade undergoes intense film cooling, the bulk of the cooling air is discharged onto the blade profile surface through perforation holes. The nozzle blade in the second stage is a single cavity, deflector type. The cooling air is discharged into the flowthrough section through a slit in the outlet edge of the blade. The entire blade system and the engineering accessories were designed in the "Unigraphics" system. Many calculations were done during design of the cooled blades: modelling the outer flow around the blade profile; hydraulic calculations of the system of cooling channels in a blade cavity; calculations of the thermal state of a blade vane and of the thermally stressed state. In the course of the design work, the blade geometry was corrected using the computational results.The temperature fields in different cross sections of the blades were obtained by solving the conjugate heat transfer problem, i.e., a simultaneous gas dynamic calculation of the gas flow in the channel between blades and calculating the heat conduction in a blade vane including heat exchange at the boundary between the gas and solid. Boundary conditions of the third kind for heat exchange in a blade cavity were specified based on the results of a hydraulic calculation of the cooling air flow.The thermal state, static and fatigue limits, and short cycle fatigue of the blades were calculated for the final blade geometry.Fabrication of cooled blades for the GTÉ-65 turbine. The choice of materials for the blades and of the engineering process for fabricating them was based on calculations of the thermally stressed state and experimental test ticket data on the alloys, with the operating conditions of the gas turbine unit and the ...

This paper presents the results of experimental and numerical investigations of cooling effectiveness of the film cooled turbine nozzle. The nozzle is with two internal cavities. Front cavity of the nozzle is fed with high pressure cooling air from compressor diffuser with minimal losses of pressure for ensuring film cooling of the leading edge. Rear cavity is with impingement tube for high effective convective cooling. Experimental measurements of cooling flow capacity and cooling effectiveness were carried out on experimental facility of OSC “NPO CKTI”. Investigations included isothermal internal flow tests and hot tests with internal flow and metal temperature measurements. Test results were compared with flow and thermal field CFD predictions. Temperature fields of body and platforms of nozzle were predicted by conjugate heat transfer simulation. Computation domain includes vane-to-vane path flow, vane solid body with shrouds and holes for cooling air injection. Heat transfer conditions inside vane were calculated with one dimension internal flow model. Isothermal internal flow test results were used to validate one dimension internal flow model. Comparison of the experimental and simulation results enabled to modify calculation models to obtain good agreement. Turbine vane temperature fields calculations in different operation conditions were carried out with validated numerical models.