The intention of the investor was the more ecological operation and upgrading of the existing operation of the cogeneration plant resulting from the principal ecological modifications and upgrading of the plant supplying heat and electric power into the distribution grid.
Within the framework of the project “ecological modifications and upgrading of the cogeneration plant Planá nad Lužnicí” there have been upgraded the existing equipments using coal. The improvement included the dismantling of the existing worn-out coal burning boilers K2 and K3 that were replaced new coal burning boilers K5 and K6 of modern design technological design. Also, the existing steam turbine has been completely reconstructed in order to comply with the new parameters and to handle the steam flow from the new boilers.
The steam output of the new boilers was 2x40 t/hr which corresponds to the terminal output of TG ~20 MWe. Part of the modernization was also the construction of a new hot-water heat exchange station within the scope of the main generating unit, which serves the supply of heating water for the system of central heat supply, which underwent extensive modernization as part of another project, and the existing steam distribution systems 0,3 MPa were replaced by warm water systems. In order to limit the emission of sulfur oxides and to fulfill the related strict limits, there was erected the new equipment for de-sulfurization of flue gas based upon the wet lime washing. The proposed connection of the TG set with steam extraction turbine with the extractions into central heat supply fulfills the requirements for cogeneration operation, that is combined generation of heat and electric power.
Within the scope of ecological modifications of the plant there have been installed 4 gas engines of electric output approx. 4x10 MWe and thermal output approx. 5 MWt in heating water and approx. 3,5 MWt in steam 10bar. The gas engines steam and generators HRSG were located in new objects, in the machine hall of gas engines and in the building of HRSG boilers.
As part of the ecological modifications and within the scope of another project there was also modified the existing steam turbine of TG3 (its nominal output has been reduced and its efficiency has been increased). Within the scope of this project there was also modified the unused boiler K4 burning natural gas and in the new conception it serves as the back-up source of steam.
Further, there were made reconstructions and modifications of other related technological equipments that will be used after reconstruction for the operation of the cogeneration plant (compressor station, ash removal, cooling cycle, system of monitoring and control, electrical equipment, etc).
The activities supported by the investment concerned also supplementary objects completing the whole civil part and infrastructure of the area affected by the construction, These include especially roads and compacted surfaces, outdoor lighting, relocations of networks and new connections, possibly also related modification of grounding, terrain and park landscaping, and also the necessary demolition works in existing affected objects.
As the general designer the company HDE has prepared the whole civil and technological parts of the design, including individual professions.