Investigation on low-pressure steam turbine exhaust hood modelling through computational fluid dynamic simulations
| Autor: | Tommaso Diurno, Lorenzo Palanti, Bruno Facchini, Leonardo Nettis, Nicola Maceli, Lorenzo Arcangeli, Antonio Andreini, Tommaso Fondelli |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
020301 aerospace & aeronautics
business.industry Flow (psychology) Mechanical engineering 02 engineering and technology Static pressure 01 natural sciences Turbine 010305 fluids & plasmas Renewable energy Power (physics) Flow separation 0203 mechanical engineering Steam turbine 0103 physical sciences Environmental science business Condenser (heat transfer) |
| Zdroj: | SECOND INTERNATIONAL CONFERENCE ON MATERIAL SCIENCE, SMART STRUCTURES AND APPLICATIONS: ICMSS-2019. |
| ISSN: | 0094-243X |
| DOI: | 10.1063/1.5138809 |
| Popis: | The constant growth of renewable energy sources has changed the working condition of the modern power plants, where a greater flexibility of the conventional units is required. Large steam turbines, for instance, have to be capable of partial load operation as well as quick starts in order to ensure a stable functioning of the power grid. This reflects on the design of the steam turbine and in particular on exhaust hoods which have a significant impact on the overall turbine performance, recovering the energy left and therefore affecting the power output. Exhaust hoods have to convert kinetic energy at the turbine last stage exit into static pressure at the condenser by decreasing the flow speed. In axial-radial hoods the flow must turn by 90 degrees in a very short distance, therefore, if such components are not well designed, this may lead to flow separation phenomena which reduce the hood recovery performance. Due to the nowadays operational requirements, it is mandatory to carefully design the steam turbine exhaust system for a wide range of operating conditions, in order to ensure high efficiencies also at partial loads.This work concerns a numerical investigation on a low-pressure steam turbine exhaust hood through computational fluid dynamic simulations, assessing several numerical methods to couple the exhaust casing with the turbine rear stage. The numerical outcomes were compared in terms of flow field distribution and pressure recovery coefficient, by allowing to define a numerical setup which is a good trade-off between results accuracy and computational effort. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|