Investigation of water phase change rotating cooling for high temperature turbine

Abstract

Thermal protection of high temperature turbine restricts the performance of gas turbine. In order to increase turbine inlet temperature, water phase change rotating cooling scheme for turbine was proposed for using the gasification latent heat to improve cooling capacity. Numerical model of phase change rotating cooling was established to study the flow and heat transfer characteristics with Ansys CFX software using SST k-ω turbulence model. Results showed that phase change rotating cooling had good performance for cooling the rotating blades. The temperature drops of blades were more than 400 K with the average heat flux of 2.42 MW/m2. Due to the influence of flow thermal acceleration effect, the outlet pressure of cooling channel reached a maximum value of 7.23 MPa with a mass flow rate of 0.17 g/s. The outlet quality distribution under rotating condition was relatively uniform than nonrotating condition. The temperature increased firstly and then decreased in centripetal channel along phase change process because of pressure variation. Meanwhile, gas-liquid interface disappeared due to the Coriolis force, resulting in higher heat transfer coefficient than static condition. The normalized Nusselt number (Nus) of phase change rotating cooling reached 3.915, much higher than static liquid cooling.