Air-cooled turbogenerators

Convenience, simplicity and flexibility

Turbogenerators with air-cooling system of “ELSIB” production are the optimum choice for the power system application that demand flexibility and simplicity of operation and service. Air-cooled generators is well suited to the cyclic and peak operating mode, allow achieving the high extent of automatization of the technological processes, reducing the operation costs significantly. Almost all generators supplied by “ELSIB” with capacity rated from 6 to 20 МW have the indirect cooling system of the rotor winding that provides the higher reliability and durability. The use of the joint insulating impregnation of the stator winding and core provides a higher resource on a capacity, heat loads and minimizes the vibration values. The coil and coil-bar stator windings allow to reduce a length of generator and increase its specific weight characteristics. A proved materials and excellently presented itself insulation system exclude an appearance of the damages at the coronas. The thermal-resistance insulation class is “F”. At the rated and maximum modes, it provides the use of “B” class insulation that allows ELSIB generators to operate at the extended modes and at the wider range of the environment. This characteristic is especially important for generators matched to the gas turbines, because capacity of those notably increases at the reduction of the ambient temperature. Air-cooled generators operate with closed-loop cooling system. The air circulation is provided with the axial fans on the shaft of rotor, and the air-to-water heat exchangers located on each side of generator remove heat from the air.

The generators of power rating from 25 to 160 MW are produced at the one-piece welded case of cylindrical shape. The design of case provides the high rigidity and strength, that allows generators to operate reliably and stably at all operation modes include cycled load, peaking duty, overload modes. This is pledge of the generator durability and reliability providing for its high operational characteristics. The air circulating inside the generator over the close loop is cooled at the air-to-water heat exchangers built in the stator case horizontally. The heat exchangers of 160 MW generator located on each side of the stator. The simple and effective cooling system is slightly soiled, that significant assists to keep relatively low heat level of the active parts and the high effectiveness of the generator at the whole lifetime. Many design solutions for air-cooled turbogenerator were based on the reliable and proved by the long time service decisions realized before at the hydrogen-cooled generators of the similar class. Due to that, the “ELSIB” air-cooled generators imbibed all the best and proved existing today at the Russian generator technology. Moreover, they possess the unique capability to be transformed into hydrogen-cooled generator with the slight modernization fulfilled on site. At the same time the capacity of generator can be increased to 150 %. This gives the additional opportunities for our customers to plan the power system changes and reconstructions. The design and manufacturing technology of the generators guarantee the high maintainability of the equipment that at great extent reduces the possible future costs of our customers. Moreover, these generators with the minimum costs can be assembled on the existing foundations of the retired turbogenerators of the same capacity class with air and hydrogen cooling system.