Projects / Programmes source: ARIS

The optimization of thermal and ecological performances of coal-fired power plants

Research activity

Code Science Field Subfield
2.03.01  Engineering sciences and technologies  Energy engineering  Efficient energy usage 

Code Science Field
T140  Technological sciences  Energy research 
T200  Technological sciences  Thermal engineering, applied thermodynamics 
power plant, efficiency, energy conservation, flue gas, emissions reductions
Evaluation (rules)
source: COBISS
Researchers (7)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  06322  Milko Čefarin  Energy engineering  Technical associate  2007  32 
2.  15990  PhD Boštjan Drobnič  Energy engineering  Researcher  2007 - 2009  200 
3.  06784  PhD Igor Kuštrin  Energy engineering  Researcher  2007 - 2009  357 
4.  23369  PhD Mitja Mori  Energy engineering  Researcher  2007 - 2009  384 
5.  09218  PhD Janez Oman  Energy engineering  Head  2007 - 2009  427 
6.  14342  PhD Mihael Sekavčnik  Energy engineering  Researcher  2007 - 2009  565 
7.  08456  PhD Andrej Senegačnik  Energy engineering  Researcher  2007 - 2009  331 
Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0782  University of Ljubljana, Faculty of Mechanical Engineering  Ljubljana  1627031  29,280 
Applicative researches that are proposed in this project originate on the base of measurement results and tests which are being performed for several years Slovenian thermal power plants by Laboratory for Heat and Power, Faculty of Mechanical Engineering, Ljubljana. Regarding the time course and significance the research activities can be classified in three groups: a) the optimization of power plant operation performances considering the lowering of the applied coals quality, b) improvements of operating shortcomings of firing process after introduction of low NOx firing of units, and c) separately for TE Šoštanj the analysis of the influence of natural draft cooling tower performance on the efficiency of a power plant. Ad- a):The investigations of optimizing of units' operation parameters due to using lower-rank coals (TE Trbovlje, TE Šoštanj) will be limited to the boiler losses due to quality of grinding and flue-gas loss due to utilizing regenerative air preheaters. One part of investigations will be dedicated to optimization of parameters of regenerative heat transfer after the additional gas turbines will be added to the existent steam cycle units in TE Šoštanj. Ad- b):The introduction of low NOx firing causes the change of the ratio of fuel mass flow through the mills and volume flow of gas through the mills. That gas is used for coal dust transportation and for cooling the mills. This phenomenon is a consequence of primary air quantity reduction. The solution will have to be found in the way in which cold flue gas are recirculated backwards to the mills. The achieved solutions will have to enable more flexible boiler operation and to ensure that the unit and boiler efficiency will be at least as high as it was before the modifications of the firing. Ad- c):The influence of natural draft cooling tower performances on the power plant efficiency, which will be investigated separately for TE Šoštanj, reflects in the fact that cooling towers with higher effectiveness convey less exergy from working cycle to the environment. The saved exergy can be than transformed into electrical power in a thermal power plant system. We must investigate the idea, that the improvement of the cooling tower effectiveness depend on the establishing the better homogeneity of mass and heat flow through the cross section of the tower. This can be achieved with a proper distribution of cooling water in the tower's rain region, which approaches the optimal ratio between mass flow of air and water at every location. We presume, that the entropy generation and in the same time exergy destruction in a cooling tower will be reduced significantly in the case of reestablish described conditions. If our assumptions are correct, the efficiency of the power plant will increase after realization of mentioned measures .
Significance for science
On the level of applied researching we achieved the results and solutions of problems connected with thermal engineering, with optimisation of operation performances of energy conversions, with combustion processes and to define the adequacy of substitutive coals. On the level of basic researchings we achieved the results on the field of analysis of transition phenomenon and analysis of parameters in power systems, especially on the field of entropy generation minimization in energy systems with highest parameters and in connection with cooling towers in thermal power plants. Some new methods were developed. The method of evaluation of suitability of substitutive coals in existent steam boilers was developed. The method was elaborated on the base of experiences with combustion tests of alternative coals in power plant boilers. The use of method gives the results for safe and reliable selection of most proper coal for burning in selected steam boiler. The method for dividing the power and heat in power and heat plants among the the different fuels using et the same time in the same plant. The results shows the quantity of individual sort of energy that was produced in heat and power plant from individual fuel used contemporary in the power plant boiler. The method was presented in the case of using coal and wood chips as supplementary fuel in the steam boiler furnace. The method of optimization of taking off the heat from steam process in power plants is founded on optimisation of cooling tower parameters.
Significance for the country
The acquired results may be applied on all Slovenian power plants where the boilers are fired with lignite and other low-quality coals. The immediate interest of the beneficiary is, in the first place the lowering the operation expenses, especially the expenses for fuel and ecological demands. In addition the expenses for maintenance and repowering are lowered and last but not least, the reliability and availability of the units are increased. The previous results and knowledge gained by project act as a strong tool for beneficiary by performing the measures for increasing the unit's quality and reliability of operation. The results of investigations that we performed until now shows, that the efficienies of the power plant units can be improve up to one percent and more. That results must be interesting for the Slovenian government as the owner of the power plants. On the other hand the reduction of the coal consumption means also the reduction of emissions of carbon diokside, sulphur diokside and other harmful emissions in environment
Most important scientific results Annual report 2008, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2008, final report, complete report on dLib.si
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