Possibility of Using Liquid-Metals for Gas Turbine Cooling System

The possibility of using heat pipes to cool elements of a gas turbine is considered. The temperature of the parts gas turbine should be approximately equal to 850–950 ℃ to ensure its safe operation. This temperature range is suitable for a special type of heat pipes with a liquid metal coolant. It is proposed to reduce the temperature gradients on the turbine blade by mounting porous reservoirs with a liquid metal coolant on the inner surface of the blade body. In a closed porous reservoir, a two-phase state of the coolant is maintained, and heat is transferred by the mutually opposite movement of steam and liquid due to diffusion. The solution to the problem of modeling the processes of motion and phase transition in a porous medium filled with coolant is presented. The problem of thermal conductivity of a multilayer system consisting of a heated shell of a blade and a porous reservoir filled with a liquid metal coolant is formulated, and a numerical solution is proposed. As a practical example of the use of high-temperature heat pipes, a new type of aircraft engine nozzle cooling system has been developed. The example consists of two parts. The first part showed a decreasing temperature gradient in the leading edge of the gas turbine nozzle. The second part concerns the development of the cooling system of the nozzle as the whole.