Archive | 2019
Numerical study of flow characteristic and heat transfer on high-pressure turbine forced cooling process of sub critical steam turbine
Abstract
Repairing turbine equipment in some cases requires a shutdown of power generating units and furthermore required stop turning gear of the turbine. To stop the turning gear on a turbine, the high-pressure turbine inner cylinder temperature must be below 130 ° C. To reach the minimum temperature requirement of a stop turning gear takes about 8 days with a natural cooling process. To speed up the cooling process, forced cooling is carried out by flowing the residual steam in the boiler and then the air flowing through the boiler at a lower temperature into the turbine. Forced cooling of the turbine by using residual steam and air from the boiler can be done by considering the rate of cooling in the turbine blade material and the turbine inner casing. The cooling process should consider the rate of temperature drop on the turbine blades so as not to cause damage to the material. Temperature distribution and rate of temperature reduction are simulated using a numerical approach namely Computational Fluid Dynamic (CFD). The temperature distribution and the rate of temperature reduction in the turbine blades will be used as a reference in the implementation of the next forced cooling process on the turbine. This research analyzes the flow distribution and heat transfer on the High-Pressure turbine blade during forced cooling.Repairing turbine equipment in some cases requires a shutdown of power generating units and furthermore required stop turning gear of the turbine. To stop the turning gear on a turbine, the high-pressure turbine inner cylinder temperature must be below 130 ° C. To reach the minimum temperature requirement of a stop turning gear takes about 8 days with a natural cooling process. To speed up the cooling process, forced cooling is carried out by flowing the residual steam in the boiler and then the air flowing through the boiler at a lower temperature into the turbine. Forced cooling of the turbine by using residual steam and air from the boiler can be done by considering the rate of cooling in the turbine blade material and the turbine inner casing. The cooling process should consider the rate of temperature drop on the turbine blades so as not to cause damage to the material. Temperature distribution and rate of temperature reduction are simulated using a numerical approach namely Computational Fluid Dynam...