Termoelektrarna Toplarna Ljubljana (hereinafter referred to as TE-TOL unit) is one of the leading Slovenian utilities for heat distribution in multi-dwelling buildings. It meets approx. 90% of the heating needs within the Ljubljana’s remote heating system.
The TE-TOL Power Station provides sufficient heat energy for distribution – mainly through the winter season – by three independent units. Thermal energy (besides heating) in the form of steam is directed to turbines connected to generator units for generation of electricity. Total installed capacity of all three units is 350 MW for thermal and 124 MW for electric power (G. Trnjak, Supply of energy products to the TE-TOL unit, Diploma Thesis, 2011).
Water pumped from Ljubljanica river is used for cooling of turbines and the generator. At the point of entry into the cooling system, two large filters were used in the past, which, however, became impassable during rainy periods. Both filters had to be cleaned manually, which was needlessly very time-consuming.
A new acquisition: Two-stage filtration
In collaboration with the TE-TOL technical staff, a corresponding solution has been found. We have installed automatic filters supplied by AMIAD and provided two-stage filtration. At the first stage, four Modular type filters DN200 with a 1000-micron filter mesh cartridge were installed. An automatic system has been installed for all four filters to control the operation of the entire system. The procedure to clean one or all four filters is triggered automatically depending on pressure drop in the filter (0.5 bar), timer-controlled or manually. All four filters are never cleaned simultaneously, which provides constant flow (360 m3/h) into the turbine and generator cooling system. At the second stage, two SAF 4500 filters DN200 with a 300-micron filter mesh cartridge were installed. At this stage too, the filter cleaning procedure commences in the same way as at the first filtration stage. The flow during the cleaning cycle is never interrupted, which ensures undisturbed operation of the unit and generator.
Cooling water filtration (project data):
|Max. pressure drop
|Filtration stage I
||4 x Modular-type, DN200, 1000-micron mesh filter
|Filtration stage II
||2 x SAF 4500, DN200, 300-micron mesh filter