Numerical investigation of influence of different underexcited operations on temperature distribution in the large turbine generator end domain with copper screen

摘要

Overheating of the complex end parts has become one of the main problems affecting safe and stable turbine generator operation under the underexcited operation. In order to study the temperature distribution in the large turbine generator end domain with copper screen under the different underexcited operations, a 330 MW turbine generator is studied. Three-dimensional fluid-thermal coupling model for the end domain of turbine generator is established. Three-dimensional transient magnetic field of the large turbine generator end domain with copper screen is calculated with 0.85 pf underexcited operation and 0.9 pf underexcited operation. Loss values of the end metal parts from the three-dimensional transient magnetic field are applied to end domain as heat source with 0.85 pf underexcited operation and 0.9 pf underexcited operation. Outlet-pressure values and fan inlet velocity from flow network calculations are applied to the end domain as boundary conditions in the fluid and thermal coupling analysis. The three-dimensional fluid and thermal fields in the turbine generator end domain are calculated with 0.85 pf underexcited operation and 0.9 pf underexcited operation. Distribution of the radial fluid velocity component around the stator winding is determined. Temperature distribution of the end metal parts in the large turbine generator end domain with copper screen is studied with 0.85 pf underexcited operation and 0.9 pf underexcited operation. Temperature calculation results of the copper screen are compared with measured values. Calculation results are in good agreement with measured values.