Upgrading the steam turbine of the PT-135 series produced 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.
From 1973 to 1991, the Ural Turbine Works produced about 45 steam turbines of this series. They are successfully operated at CHP plants not only in Russia but also in foreign countries such as the Republic of Belarus, Kazakhstan, and many others.
The upgrade of the steam turbine of the PT-135 series allows to get a modern turbine unit using buildings, foundations for equipment, crane facilities and replacing only outdated equipment with the new, more advanced one.
The Ural Turbine Works offers a comprehensive approach to upgrading the steam turbine of the PT-135 series, including a wide range of technical solutions to upgrade the turbine units in a more timely, efficient, and cost-effective manner. The scope of the PT-135 series steam turbine upgrade includes
The existing valves are replaced with the valves of new design, which excludes the possibility of unloading valve hanging and, therefore, eliminates the situations of under-closing of the stop valve during scheduled outages and emergency shutdowns of the turbine unit.
New design of the high-pressure cylinder optimized for increased fresh steam flow. The proposed design of mass-produced turbine's cylinder reflects all the measures aimed at improving turbine unit’s efficiency and reliability.
Installation of an upgraded cam-operated switchgear with a high-rigidity frame and bearings with increased load-bearing capacity.
New design of the high-pressure control valves with perforation holes on the bottom profile part of the valve, reinforced stem suspension points, valve seats with diffusive inlet part.
Installation of a new welded cast cylinder and placement of an upgraded flow part in it. Installation of water trap rings with shut-off guide blades behind 25 (24) steps, which prevents the formation of secondary moisture in the flow part and, consequently, reduces erosive wear of rotating blades.
The rotor of new design with installation of upgraded blading of 20, 21, and 22 steps, capped discs of 18 and 19 steps instead of solid forged ones to increase reliability.
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 low-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.
