Upgrade of the CCPU-420 of the Mosenergo CHPP-20 Increasing Its Efficiency

Abstract

A technical solution aimed at increasing the generation and expanding the operating capacity range and successfully implemented at CCPU-420 of the Mosenergo CHPP-20 is presented. In accordance with the technical proposals by the Siemens (SGTT) as a GT supplier, several SGT5-4000F gas turbines were upgraded at Russian thermal power plants with single-shaft CCPUs, which made it possible to increase the installed capacity of these installations by 30 MWon average (so-called SP8 package). Single-shaft CCPUs were chosen for the upgrade mainly because such installations are intended to operate in condensing mode only. In 2018, the Mosenergo Company decided to upgrade the SGT5-4000F gas turbine of Power Unit No. 11 of the Mosenergo CHPP-20. It was originally designed for heating purposes and, therefore, had a SST5-5000 two-shaft steam turbine with its own electric generator and two steam extractions for PSG-1 and PSG-2 network heaters. The unit was certified by the SO-UPS based on tests at an installed capacity of 418 MWunder normal conditions. The service interval of the SGT5-4000F gas turbine was set by the manufacturer at 25,000 equivalent operating hours (EOH), which corresponds to three years of operation approximately. The goals of the main inspection of the SGT5-4000F gas turbine were upgrading the gas turbine and increasing its capacity, implementing the concept of “flexible” service intervals ranging from 33,000 to 50,000 EOH, depending on the operating mode of the gas turbine. Accomplishing the second task will increase the periods of operation between inspections to 4 – 6 years, which will reduce the cost of servicing GT and CCPU equipment without reducing its reliability.