Serbia: TPP Kostolac overhaul completed and prepared for winter power gen

25. October 2013. / News Serbia Energy

All the blocks within TPPs have undergone short overhauls, because the block A1 is scheduled to undergo major overhaul activities next year, and the block A2 in 2015.

– Last year’s rehabilitation of the block B2 has brought in significant technological improvements.

Overhauls on the blocks of Kostolac TPPs have been completed, so the upcoming period is expected to be marked by stable electricity generation in thermal power plants “Kostolac A” and “Kostolac B “. As Mr. Zoran Stanojević, the Director of the Department for Electricity Generation in the company “TPPs and OPMs Kostolac ” points out, the scope of this year’s overhauls has been reduced.

– All the blocks within TPPs have undergone short overhauls, because the block A1 is scheduled to undergo major overhaul activities next year, and the block A2 in 2015 – says Mr. Stanojević. – A very significant major overhaul of the block B1 is planned for the next year, and it will last several months.

Last year’s rehabilitation of the block B2 has brought in significant technological improvements and marked the beginning of this plant’s operation with the projected capacity.
– The main goal of the block B2 major overhaul was to get the plant capable to operate in a stable manner with increased power. The revitalization of the block B2 has been done along with the adaptation of electrostatic precipitators, and within this overhaul, two major technological requirements have been fulfilled – explained the Director of the Department for Electricity Generation. – The first one was testing of the electrostatic precipitators’ performance with respect to particulate emission, while the other major technological requirement refers to the testing of boiler plant performance regarding the mills capacity and grinding fineness.

After several months of testing, now it has been proven that the electrostatic precipitators work in accordance with the established requirements, and measurements have been made early this month, for which the “Vinca” Institute has been responsible.  The mill capacity was found to exceed the required value while the grinding fineness was close to the contracted value, by which it has been proved that the major overhaul of the block B2 was successfully completed in its entirety.
As for the revitalization of the block B2, it should be noted that this undertaking has lasted for about three years.,

– The turbine reconstruction has resulted in increased power production by 30 MW, but then, the entire main plant facility needed to be taken care of – said the director Stanojević,.

– We are talking about boiler plants and their faults occurring after several years of operation in the pipe system, as well as about all being worn out on the coal line. A large part at the boiler pipe system has also been replaced, and a reconstruction of the slag removal section under the boiler has been done when a new type of afterburning grate has been installed. Thus, the process of turbine reconstruction has been completed, which has been followed by the tuning of combustion and the block operation. These are the tasks for achieving stable combustion, block control and heating for years to come.
The revitalization of the block B1 in TPP “Kostolac B” will start next year. Complex technological procedures should be completed during 2014, which will require a precise and carefully coordinated organization of works.

– Next year, the major overhaul of the block B1 will be carried out. Our plan is to reduce the overall time for revitalization, which was three years in the case of block B2, to just one year – said Mr. Stanojević . – The plan also envisages major works on the turbogenerator plant – We will try to include a transformer block in those works. In addition to all this, parts of the Chinese package related to flue gas desulphurisation plant should be included. The deadline for these works is nine months, which means that a good organization shall be the imperative when performing these works.
According to Mr. Zoran Stanojević’s opinion, it is reasonable to expect compensation of somewhat reduced electricity generation in Kostolac power plants, taking into account that there is a small delay in fulfilling this year’s plan.

– There is a certain delay in the production of electricity, primarily due to the testing performed on the unit B2. We have often operated at reduced power, carried out works relating to the afterburning grate, had a lot of coarse grinding of coal that influenced combustion process in a way that a large portion of coal was coming as unburnt on the grate, and this is where the mechanical damages happened – stressed Mr. Stanojević

– There had also been minor weaknesses in the construction, which were identified and replaced afterwards. All of this is a part of the block running in, so now we can say that the block B2 is stable for the upcoming winter season. We estimate that we will have higher production than envisaged for this block, thus we will be able to make up for what we have missed. The downtimes of the block B1 have also been recorded. These are the parts of the plant that are envisaged to be replaced within the revitalization and on the run can be solved in one day. There had been problems with the cooling water from the lake for condenser cooling, which affected the vacuum and thus the block power. Now the temperature is lower and we are entering a period with favorable weather conditions for the operation of our plants.

Source; EPS/Kwh

Download as PDF :

Download PDF