COMPREHENSIVE METHODS OF EVALUATION OF EFFICIENCY AND OPTIMIZATION OF HEAT-UTILIZATION SYSTEMS
At present, Ukraine has the necessary potential for the implementation of effective energy-saving technologies for heat recovery, and therefore the problem of their development and implementation is relevant for the country's energy sector. The solution of this problem is related to the need for systematic studies of the efficiency of optimization of heat recovery facilities from the standpoint of modern methodological approaches. The paper outlines the main stages in the development of integrated methods for assessing the efficiency and optimization of heat recovery systems based on the principles of exergic analysis, statistical methods for planning the experiment, structured variational methods, multilevel optimization methods, the theory of linear systems and the thermodynamics of irreversible processes. Examples and illustrations illustrate some of the stages in the development of complex methods. The necessary general step in the development of methodologies is the development of new performance criteria. Such criteria are highly sensitive to changes in the regime and design parameters of heat recovery systems due to the inclusion of some exergic characteristics in them. The developed criteria also serve as target optimization functions. For individual elements of heat recovery systems, efficiency and optimization methods usually include the definition of the functional dependencies of the selected efficiency criteria on the main parameters. For this, balance methods of exergic analysis and statistical methods of experiment planning are used. If such dependencies are established, optimization is carried out using known mathematical methods. For complex heat recovery systems involving a large number of elements, it is not possible to establish general analytical dependencies of the optimization objective functions on the parameters of the system when constructing mathematical models necessary for their optimization. Complex methods based on the basic principles of structural-variant methods, methods of multilevel optimization, the theory of linear systems, and the thermodynamics of irreversible processes have been developed for such cases. For this purpose, structural diagrams of plants, block diagrams of multi-level optimization have been developed, complete input matrices have been constructed, mathematical models for the processes under investigation have been developed, formulas have been derived for calculating the loss of exergy power in heat conduction processes and formulas for calculating dissipators of exergy. A well-founded choice of the methodology for evaluating efficiency and optimization raises the effectiveness of optimization, since it allows the use of parameters maximally close to optimal when developing the heat recovery system design, which in turn increases the efficiency of the system. References 14, figures 5.
2. Dʹyarmati I. (Ed.), (1974). Neravnovesnaya termodinamika [Nonequilibrium thermodynamics]. Moskva: Mir, 247, [in Russian].
3. Pekhovich A. (1976). Raschety teplovogo rezhima tverdykh tel [Calculations of the thermal regime of solids] / Zhydkykh V. Leninhrad: Enerhiya, 351. [in Russian].
4. Pardo E. (1991) Analisis Exergetico у Termoeconomico de Procesos industriales. Madrid, 238.
5. Alvarado S. (1994) Cherardelli С. Exergoeconomie Optimization of Cogeneration Plant. Energy 124.
6. Fabbi G. (1998) Heat Transfer Optimisation in Internally Finned Tubes under Laminar Flow Condition // Int. J. Heat Mass Transfer, 41,1243-1253.
7. Valero A. (1998) Algebraic Thermodynamic Analysis of Energy Systems / Torres C. ASME Book no. G00452 WAM, 7, 13 – 23.
8. Fialko N. (2011). Eksergo-tekhnologicheskaya effektivnost' gazovozdushnykh teploutilizatorov energeticheskikh ustanovok [Exergo-technological efficiency of gas-air heat-recovery devices of power plants] / Fialko N., Prokopov V., Stepanova А. еt al. Promyshlennaya teplotekhnika 33(3), 42-49. [in Russian].
9. Fialko, N. M. (2013). Ekolohichna efektyvnist kombinovanykh system utylizatsiyi teploty vykydnykh haziv kotelnoyi ustanovky [Ecological efficiency of combined heat recovery systems waste of exhaust gases for boiler plant]. Visnyk Natsionalnoho universytetu Lvivska politekhnika. Teoriya i praktyka budivnytstva [Bulletin of Lviv Polytechnic National University. The theory and practice of construction] / Fialko, N., Presich, G., Navrodska, R., Gnedash, G. (755), 429 – 434. (in Ukr.)
10. Fialko N. (2014). Effektivnost' teploutilizatsionnoy ustanovki dlya kotel'nykh, optimizirovannoy razlichnymi metodami [The effectiveness of a heat re-covery boiler installation optimized by various methods] / Fialko N., Stepanova A., Navrodskaya R. еt al. Promyshlennaya teplotekhnika. 36(1), 41-46. [in Russian].
11. Navrodska R. (2015). Pidvyshchennya efektyvnosti teploutylizatsiynykh tekhnolohiy dlya kotelnykh ustanovok komunalnoyi teploenerhetyky [Improving the efficiency of heat utilization technologies for municipal heating boilers]. Naukovyy visnyk NLTU Ukrayiny [Scientific Bulletin of UNFU], 25(9), 225–229. (in Ukr.)
12. Stepanova А. (2016) Macroscopic model of a three-phase thermodynamic system of variable mass // Enerhetyka y avtomatyka, (4),133-144 (in Rus.).
13. Fialko N. (2017). Analiz effektivnosti kotel'noy ustanovki s kombinirovannoy teploutilizatsionnoy sistemoy pri razlichnykh rezhimakh raboty kotla [Analysis of the efficiency of the boiler plant with a combined heat recovery system under various operating conditions of the boiler] / Fialko N., Stepanova A., Navrodskaya R. еt al. Promyshlennaya teplotekhnika. 39(1), 33-39. [in Russian].
14. Navrodska R. (2018). Eksperymentalni doslidzhennya teploobminu pid chas hlybokoho okholodzhennya produktiv zhoryannya hazospozhyvalnykh kotliv [Experimental investigation of heat-transfer at deep cooling of combustion materials of gas-fired boilers] / Navrodska R., Stepanova A., Shevchuk S., Gnedash G., Presich G.Naukovyy visnyk NLTU Ukrayiny [Scientific Bulletin of UNFU], 28(6), 103–108. https://doi.org/10.15421/40280620 (in Ukr.)
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