Operation of units with adjustable-blade turbines converted to a propeller regime: Fid-Bau Portal

Operation of units with adjustable-blade turbines converted to a propeller regime

Markin, V. N. / Tomilin, V. I. / Il'in, A. Yu.

Conclusions The conversion of AB turbines to a PR at all investigated hydrostations is due to equipment defects and not to economically justified considerations in connection with altered operating conditions (streamflow regulation, i.e., a decrease of the range of fluctuations of the heads; changes in the characteristic load curves, increase of requirements imposed on the reliability of power supply), i.e., it should be regarded as a forced temporary measure until reliable operation of the runner blade seals is provided.The problem of providing reliable (without oil leaks) operation of AB turbine runners should be solved in the following directions: reconstruction of seals of old types by the plants and the use of superior sealing materials; retrofitting of the runner with an “oilless” hub for subsequent changing to the production of AB turbines just with runners of the modification.When it is necessary to convert AB turbines to a propeller regime the cost effectiveness of this measure should be analyzed with consideration of the operating regime, and special tests should be conducted to check the guarantees of regulation and to determine the reliability in all operating regimes (starting, stopping, idling, SC regime, etc.) with measurement of vibration and wobbling of the shaft.It is necessary to revise the firmly rooted practice of the unequivocal selection of AB turbines without fail for low-head hydrostations. The selection of the type of turbine for installation at hydrostations being designed or modernized with considerable daily variations of the head (1.5–2.0 m) should begin with an examination of the variant with propeller turbines as sufficiently reliable, cheap, and simple to operate. In the case of considerable seasonal variations of the head, the variant with discrete regulation of the runner blade angle is permissible.For some power systems it is advisable to examine a variant with the use of two types of turbines and assignment to each type of turbine operation in its own particular zone of the load curve. This means that in the system it is necessary to have turbines with dual regulation (adjustable-blade) and more simple ones (propeller or mixed-flow), which will make it possible to avoid irrational losses of power in AB turbines at peak hours.