Dolhov O. Thermohydraulic substantiation of the optimization model of the calculations of the gas turbines cooling system

Research object are the processes flow and heat transfer in the high-temperature gas turbines. The purpose of research is substantiation of thermal-hydraulic optimization model of gas turbine cooling system by further developing methods for calculating the thermal state of the gas turbine and hydraulic schemes of cooling systems, the application of optimization techniques. Methods: Theoretical postulates of the thesis is based on the fundamentals of the theory of heat transfer, fluid dynamics, numerical methods for solving problems of heat conduction, convective heat transfer, methods of calculation branched hydraulic networks. Theoretical and practical results: it was developed method and its computer program for the calculation and optimization of the cooling of gas turbines. The computer program has been validated and is used in enterprises gas turbine. The novelty: for the first time it was proved and developed a phased methodology to optimize the cooling of gas turbines, which relies on consistent calculations of cooling schemes of with one-dimensional and two-dimensional theory of thermal conductivity to determine the temperature of the blades, which allows to optimize the cooling of gas turbine blades, varying almost 50 geometric parameters of cooling channels; it was further developed methods for calculating the thermal state of the gas turbine and hydraulic cooling systems through the use of modified similarity equations for heat transfer in the cooling channels, allowing to reach the required flow of cooling air and clarify the surface temperature of the gas turbine blades 30 ... 50 °C; basing on numerous experiments it was obtained new data on the effect of temperature factor on the heat transfer in the cooling channels. For the first time it was found that a large temperature difference, which is typical for the cooling channels of gas turbines, has a significant effect on heat transfer in smooth channels but for channels with turbulators, where there is intense mixing of air, the effect of temperature on the heat transfer disappears. Degree of the implementation: SE Zorya-Mashproekt" (Nikolaev), Limited Liability Company "Actual IC mechanic" (Kharkov), the department of turbine NTU "KPI" (g. Kharkov). Use: turbine enterprises.