The upgrade of the steam turbine of the T-250 series manufactured by the Ural Turbine Works implies documentation for the previously developed and service-tested units for other steam turbines and new patented modern technical solutions aimed to improve and upgrade separate units, parts of the turbine, and related equipment.
The turbines of this series are installed and successfully operated at 31 powerful CHP plants in Russia, Ukraine, and Belarus providing such megacities as Moscow, St. Petersburg, Kiev, Kharkov, and Minsk with electric power, heat, and hot water.
The upgrade of the steam turbine of the T-250 series allows to get a modern turbine unit using buildings, foundations for equipment, crane facilities and replacing only the outdated equipment with new, more advanced one.
The Ural Turbine Works offers a comprehensive approach to the T-250 series steam turbine upgrade, which includes a wide range of technical solutions to upgrade the turbine units in a more timely, efficient, and cost-effective manner.
The scope of the T-250 series steam turbine upgrade includes
The high-pressure cylinder features double-walled and reverse-flow design. In the upgraded cylinder, the internal body of the high-pressure cylinder features new design, in particular the left flow blading with the reduction of root diameter of the control step and the addition of one pressure stage. The outer body has six pressure steps. The newly manufactured high-pressure cylinder has the same dimensions as the dismantled cylinder and is installed on the existing foundation without its reconstruction.
The control step is manufactured in the form of integral blade packages consisting of the three blades to increase the reliability of operation.
The high-pressure rotor is solid forged featuring rotating blades with integral bandages and aerodynamically more advanced profiles and outlines of steam passages.
New design of the high-pressure valve blocks with improved reliability and improved gas-dynamic characteristics allows to significantly reduce pressure losses in them. Each high-pressure valve block contains one stop valve and two control valves connected to four groups of nozzles with a total of eight leak-off tubes.
The upgraded medium pressure cylinder – 1 has nine pressure steps. The design of the cylinder’s steam admission chamber and the wicket gate of the 14th step has been changed to prevent erosive wear of the wicket gate and rotating blades of the 14th and 15th steps and to increase the reliability of operation. The newly manufactured high-pressure cylinder has the same dimensions as the dismantled cylinder and is installed on the existing foundation without its reconstruction.
The diaphragms of the medium-pressure cylinder - 1 are designed with improved aerodynamic characteristics of the guide chambers.
The design of the medium pressure cylinder the rotor – 1 is solid forged with rotating blades which have integral bandages and aerodynamically more advanced profiles and outlines of steam chambers.
New valve blocks are designed with the changes in the geometry of the flow part to ensure the steam flow uniformity and reduce losses on the pressure throttling.
The electro-hydraulic turbine control and protection system with a patented three-channel turbine protection unit has been introduced and integrated into the automatic process control system.
In the new system, the current coming from the turbine rotor is branched off by brush current collectors insulated from the bearing body, grounding is done by a separate wire with its inclusion in the circuit of the ammeter and current relay, which allows to control the ground current.
Installation of the layered thrust pads in a thrust bearing allows to significantly increase the bearing load capacity by reducing the thermal and power deformation of the pads, which is ensured by forced oil cooling of the hottest part of the thrust pads as well as the use of steel bearing base.
The type of the high and medium-pressure cylinder seals is determined by the customer (honeycomb, labyrinth, radial, axial-radial, and metal-ceramic seals are available).
The upgrade of the turbine has a high degree of customization and is tailored according to specific customer requirements. All units feature advanced design.
The control step is manufactured in the form of integral blade packages consisting of the three blades to increase the reliability of operation.
The diaphragms of the medium-pressure cylinder - 1 are designed with improved aerodynamic characteristics of the guide chambers.
