chapter  1
46 Pages

Modeling the Assessment and Monitoring of Reliability of the Condensation Thermal Power Plants (Co-TPP)

ByZdravko Milovanović, Svetlana Dumonjić-Milovanović

The development and use of condensation thermal power plants (Co-TPP) is characterized today by great complexity, regardless of whether a technological scheme or built-in equipment is observed. On the other hand, large energy 2plants with new or improved solutions can be built only in case they have a high degree of safety and reliability and when they fully meet the applicable environmental criteria. Any disturbance in the operating mode of such a plant or reduction of its power also affects the electric power system (increase in the reserves of production capacities in it, uneven supply of electricity to consumers, etc.). Reliability assessment methods are mainly based on results of experiments on the set of system components based on observations of parameters of number and/or time of failure. In order to determine the reliability of components, it is necessary to either conduct some long-term and very expensive tests on a very large number of samples under special operating modes collect the data from exploitations, which is very risky. At the same time, the choice of general mathematical methods is especially important, due to the different shapes of the curves which quantitatively define the reliability with different functions of the failure rate and the great dependency of such curves on the change in the operating mode of the components and environmental conditions. In an attempt to overcome the above problems, we find that the introduction of approximate calculations gives an overview not only of the basic characteristics of the reliability of the observed system as a whole, but also insufficiently exact final parameters, due to a whole series of larger or smaller approximations, as well as the inability to take into account all the existing influences (development of new technologies, specificities of new disorders, etc.). On the other hand, the calculation of reliability of a complex system represents only the first initial phase of verification of quantitative features, that is, the very formed hypothesis in which we have more or less confidence. Their final acceptance or refusal represents the verification of reliability through the control of certain quantitative indicators of the system for the set technical conditions of operation. For these reasons, the alternative concepts, such as reliability control or hypothesis testing, have been often used in the literature to verify the reliability. Diagnostics, the evaluation of the state of elements of the facility together with tracking the progression of its aging, is very complex, responsible, and expensive task which demands educated personnel and modern diagnostic equipment. Diagnostic equipment available in the market is filled with diversity and methods used for diagnostic purposes are not generally accepted. The results of conducted diagnostic controls do not always give full answers, so that they are often limited to the monitoring of trend of change of observed diagnostic values. Consequently, experience becomes an unavoidable and immeasurable element of diagnostics. Experience itself is of course only possible to be acquired through the work and usage of diagnostic equipment, but it is also necessary to keep in mind the cost of experience acquirement in relation to a risk of investment in testing equipment. Development of diagnostic methods is intense regarding both field and laboratory methods but efforts to provide more and more cost-effective application methods are highly required. By developing new technologies and through the application of modern equipment and tools for monitoring of present state and diagnostics of the primary gear, the cost of 3routine maintenance that makes possible to recognize priorities of intervention maintenance can be decreased.