Cooling system for the new 600 MW Unit 6 at the Šoštanj Thermal Power Plant

By constructing the 164 m high cooling tower RUDIS implemented one of the most demanding construction works lately realised in Slovenia

For reliable energy supply to the Republic of Slovenia a new Unit 6, power 600 MW, will be constructed in the Šoštanj Thermal Power Plant. Building of Unit 6 is comprehensive and consequently the Employer divided the Invitation for Bids into several autonomous Lots. In addition to construction of the Flue Gas Desulphurization Plant Rudis was awarded also constructing of the cooling system for Unit 6, as the Leading partner in the Consortium with the German partner SPX Cooling Technologies GmbH.

The function of the cooling system is to discharge the heat from the steam circulation process and other parts of Unit 6 into the atmosphere. The treated flue gas will be conducted from the Flue Gas Desulphurization Plant through the flue gas duct of 8 m diameter directly into the cooling tower.

Tower height 164 m, lower diameter 100 m, minimum wall thickness 18 cm

Due to specificity of the plant – height 164 m, lower diameter 100 m and minimum wall thickness only 18 cm, elaboration of the project documentation, execution of foundation and construction of the tower were extremely demanding, also for the reason of very diversified composition of the soil, high earthquake factors, interference wind influence, VGB requirements,...


Termoelektrarna Šoštanj
Completion date:
Scope of works:

Construction of the cooling system for Unit 6


Heat emitted into the atmosphere via the cooling tower is removed by the cooling water, which takes over the heat from the condenser, coolers of the closed cooling system, vacuum pumps and coolers of the step-up transformers. So heated water is cooled down in the cooling tower where in the area of spray unit it sprays into small droplets cooled by air passing through the cooling tower in the opposite direction of the sprayed droplets flow.

The cooling system project consists of two inter-linked segments, namely the cooling tower with equipment and pumping station with cooling pipelines. The cooling system can roughly be divided into the following assemblies:

  • cooling tower with natural draft conceived as monolithic hyperbolic reinforced concrete shell serving for cooling down of the hot cooling water and discharge of the treated flue gas into the atmosphere,
  • two main cooling pumps for water pumping via the condenser into the cooling tower, located in the main turbine building,
  • pipelines through which the cooling water flows
  • equipment for mechanical treatment of water from the cooling tower and
  • flue gas duct, diameter 8m, in total length 115m; the flue gas duct enters the cooling tower at approximate height 50m.
Description of works:

The contract with the Employer was signed in February 2010 according to the »turnkey principle«, with the exception of foundation (unit price principle).

Rudis started implementing the project by designing phase. Rudis elaborated the complete Building Permit documentation and on behalf of the Employer obtained the building permit. Construction of the cooling tower, including the foundation, was carried out from April 2011 to May 2012.

Anti-corrosion protection of the cooling tower shell and assembly of the cooling tower equipment is in progress.

All works on the cooling system of Unit 6 in the Šoštanj Thermal Power Plant will be completed until autumn 2013 and the plant will be ready for professional technical inspection, and taking over of the plant by the Employer will follow in the year 2015.

Technical data:
  • heat transfer: 637 MW
  • cooling water flow: 61,000 m3/h
  • cooling tower lower diameter: 100 m
  • cooling tower height: 164 m
  • flue gas flow: 2,240,000 Nm3/h
This site uses cookies. By continuing to browse this site, without changing the settings of your cookies, you accept our Terms of cookies. Accept Cookies What are Cookies?