Study of the effectiveness of the turbine condenser air extraction system using hydro ejectors

The aim of the paper is to investigate the effectiveness of the 18K380 steam turbine condenser air extraction system using hydro ejectors. Motivation for the analysis was a need of improvement of the energy conversion ratio of the power plant. To achieve this goal it was necessary to establish efficiency of each subsystem of the energy cycle. The air extraction system is not a highly power consuming system but it has great impact on the steam cycle efficiency by influence on the condensation temperature. The air extraction system effectiveness depends on a weather conditions, exactly on the ambient temperature, which raises the question whether it is worth to modernize the hydro ejectors or replace them by a centrifugal vacuum pumps. To establish the vacuum system effectiveness a new innovative mass flow measuring system has been implemented to measure an air-steam mixture flow and the fraction of the air mass in the mixture. The measuring system is based on a Venturi nozzle supplemented with a temperature drop during the mixture expansion.