Thermo-ecological cost (TEC) evaluation of metallurgical processes

Metallurgy represents a complex production system of fuel and mineral non-renewable resources transformation. The effectiveness of resource management in metallurgical chains depends on the applied ore grade and on the irreversibility of components of the system. TEC can be applied to measure the influence of metallurgy on the depletion of natural resources. The paper discusses the possibility of application of TEC in metallurgy and presents illustrative example concerning blast-furnace process

Methods of mathematical modeling for evaluation of energy management of blast-furnace plant

The reduction of energy consumption in the blast furnace is still the subject of investigations using mathematical modelling of a blast furnace plant. Theoretical-empirical hybrid models of a blast furnace and its equipment have been presented. This model is built based on the mass and energy balances of furnace zones and empirical data from the measurement of a blast furnace. The results of a numerical simulation of the injection of auxiliary fuels and the top-gas recirculation after the removal of CO2 to the blast furnace have been presented

Application of the entropy information for the optimization of an additional measurements location in thermal systems

For the optimal location of an additional surplus measurements in the design of redundant measurements system, from data reconciliation point of view, of thermal processes, an information entropy has been applied. The relative entropy - Kullback-Leibler divergence, has been used. As a criterion of the optimal location of an additional surplus measurements in a system of measurements data, the minimum of the entropy information of reconciled measurements data has been assumed. Hence, the objective function in the described optimization task is maximum of the relative entropy - Kullback-Leibler divergence concerning sets of raw and reconciled measurements data. Simulation calculation with application of data reconciliation algorithm and Monte Carlo method concerning the influence of installation of the additional surplus measurements on decrease of entropy information of measurements after data validation have been carried out. The example calculations concerned the cross high-pressure heat regeneration system with cascade flow of condensate installed in 153 MW power unit equipped with cooler of steam are presented. Calculations for all variants of configurations of an additional surplus measurements in the analyzed thermal system have been done. Usefulness of the proposed Kullback-Leibler divergence as a objective function has been demonstrated

Identification of unmeasured variables in the set of model constraints of the data reconciliation in a power unit

In generalized method of data reconciliation as equations of conditions beside substance and energy balances can be used equations which don't have precisely the status of conservation lows. Empirical coefficients in these equations are traded as unknowns' values. To this kind of equations, in application of the generalized method of data reconciliation in supercritical power unit, can be classified: steam flow capacity of a turbine for a group of stages, adiabatic internal efficiency of group of stages, equations for pressure drop in pipelines and equations for heat transfer in regeneration heat exchangers. Mathematical model of a power unit was developed in the code Thermoflex. Using this model the off-design calculation has been made in several points of loads for the power unit. Using these calculations identification of unknown values and empirical coefficients for generalized method of data reconciliation used in power unit has been made. Additional equations of conditions will be used in the generalized method of data reconciliation which will be used in optimization of measurement placement in redundant measurement system in power unit for new control systems

Ocena egzergo-ekologiczna wdmuchiwania paliw zastępczych do wielkiego pieca

Metallurgy represents complex technological chain supplied with different kinds of primary resources. Iron metallurgy based on blast-furnace process, dominates in world steel production. Metallurgical coke is the basic fuel in this case. Its production is connected with several environmental disadvantageous impacts. One of them is the extended production chain from primary energy to final energy. The reduction of coke consumption in the process can be achieved e.g. by injection of auxiliary fuels or increasing the thermal parameters in the process. In present injection of pulverised coal dominates while recirculation of top-gas seems to be future technology. However, the latter one requires the CO2 removal that additionally extended the production chain. The evaluation of resources management in complex energy-technological systems required application of advanced method based on thermodynamics. In the paper the system exergo-ecological assessment of pulverised coal injection into blast-furnace and top-gas recirculation has been applied. As a comparative criterion the thermo-ecological cost has been proposed.Metalurgia reprezentuje złożony łańcuch technologiczny zasilany różnymi rodzajami zasobów pierwotnych. Proces wielkopiecowy jest dominującą technologią w światowej metalurgii żelaza. Podstawowym paliwem w tym przypadku jest koks metalurgiczny. Produkcja koksu jest związana jednak z szeregiem niekorzystnych oddziaływań środowiskowych. Jednym z nich jest wydłużony łańcuch przemian od pozyskania zasobów energii pierwotnej do wytworzenia koksu. Redukcję zużycia koksu w wielkim piecu można osiągnąć przez wdmuchiwanie paliw zastępczych lub przez zwiększanie parametrów termicznych dmuchu wielkopiecowego. Obecnie w nowoczesnym procesie wielkopiecowym dominuje wdmuchiwanie pyłu węgla kamiennego. Jako technologię przyszłościową zaś wymienia się recyrkulację gazu wielkopiecowego do strefy dysz wielkiego pieca. Recyrkulacja gazu wymaga jednak zastosowania usuwania CO2, co wiąże się z dodatkowymi nakładami energii. Ocena efektywności gospodarki zasobami w złożonych systemach energo-technologicznych wymaga zastosowania zaawansowanych metod opartych o prawa termodynamiki. W pracy zaprezentowano systemową egzergo-ekologiczną ocenę wdmuchiwania pyłu węglowego oraz recyrkulacji gazu gardzielowego do wielkiego pieca. Jako kryterium porównawcze zastosowano wskaźnik kosztu termo-ekologicznego