Browsing by Author "Boshnakov K."

Now showing 1 - 8 of 8
  • No Thumbnail Available
    Item
    Case-based reasoning control of biological wastewater treatment
    (2014-01-01) Atanassov A.; Boshnakov K.
    The paper presents the usage of Case-Based Reasoning (CBR) approach for supervisory control of Wastewater Treatment Plants (WWTP) intended to better water purification. Proposed CBR supervisory control of WWTP is based on the cases. Each case contains specific regulators setpoints, corresponding to different situation in the plant, caused by different internal or external factors. Instead of solving on-line optimal control tasks CBR approach was applied. So, the regulators set-points are selected on the base of similarity between current situation (case) and already available solutions in the case-base database.
  • No Thumbnail Available
    Item
    Cost oriented redesign of condition-based maintenance of copper converting process
    (2013-01-01) Hadjiski M.; Boshnakov K.; Ginchev T.
    The presented investigation is focused on one important maintenance problem - tuyeres wear and their free section reduction solidification of melt. The results of experimental data show that this is nonstationary stochastic process. Legacy SCADA system provides data available only for the failure based maintenance. This results in a big losses in productivity of the metallurgical plant. In the present paper legacy hard instructions based maintenance system is re-designed in order to realize more effective condition based maintenance (CBM). Decision making process is based on adaptive forecasting and CBR procedure. The proposed re-engineering is cost oriented. The re-designed system gives competitive advantages, keeps the risk up to chosen settings, improves the operator's performance, and reduces the maintenance expenses. Copyright © 2013 IFAC.
  • No Thumbnail Available
    Item
    Decision making for control of combustion process of pulverized coal
    (2015-01-01) Boshnakov K.; Petkov V.; Nikolov M.
    A method and system for decision making and control (DMC) of combustion process of pulverizing fuel-air mixture in large multiburner furnace is proposed. Due to the lack of necessary information inference measurements are created on the basis on the first principle CFD model of the combustion process and a sequential image processing. Decision making procedure is based on Case Based Reasoning and Rule Based Reasoning which contains some elements of knowledge, acquired via a long time operator experience and off-line simulations on the CFD - model. Combination of off-line and on-line procedures is accepted in to two stage algorithm of DMC which improves the efficiency and safety of combustion process.
  • No Thumbnail Available
    Item
    Decision support system for condition based maintance of steel casting ladles
    (2019-01-01) Petrova I.; Mihailov E.; Boshnakov K.
    In these paper are represented the results from the capability evaluation for establishing small size defects with crack shape in the area of the joints between the refractory bricks. For the investigation methods for complex approach are developed and embedded upon diagnostic and evaluation of the equipment condition, based on the use of the results from the thermographic measurements in combination with those from mathematical simulation of the transient heat transfer (describing the heat exchange processes and temperature fields depending on the insulation thickness, type of refractory materials and conditions of operation) and visual expertise. A multi-model approach has been suggested for evaluation of the defect criticality with the purpose of diagnostic of the condition and taking a decision on the maintenance and operation of the steel cast ladle. A Decision Support System for operation and maintenance of the steel casting ladles with the purpose of the safe utilization of their maximal resource is presented.
  • No Thumbnail Available
    Item
    Diagnosis of metallurgical ladle refractory lining based on non-stationary on-line data processing
    (2013-08-29) Petkov V.; Hadjiski M.; Boshnakov K.; Mihailov E.
    A new method for diagnosis of the remaining thickness of metallurgical ladle refractory lining working in a batch mode is proposed, where directly measured by a thermovision camera data about the amplitude and phase delay of the maximum surface temperature is used. Regression equations are obtained to determine the remaining thickness of the ladle refractory lining depending on the parameters of steady auto oscillations of the maximum surface temperature. It is shown that the data from nonstationary auto oscillations could be used for adaptation of the regression equations, predicting the remaining thickness of the ladle refractory lining in case of a local damage.
  • No Thumbnail Available
    Item
    Modeling of the dynamic behaviour and energy consumption of the heating process of wooden houses
    (2006-01-01) Deliiski N.; Hadjiski M.; Boshnakov K.
    A summarized mathematical model has been created, solved, and verified for the transient non-linear heat conduction and energy consumption in wooden houses at arbitrary, encountered in the practice initial and boundary conditions. The paper presents the creation and the solution of the model, and the simulative investigation of the impact of the surrounding and room's medium parameters and the initial wood temperature on the change of the heat energy consumption, needed for reaching of different set temperatures in the rooms of the house. The obtained results are used in other papers of the authors for the creation of an algorithm and a system for optimized model predictive control of the energy consumption, required for heating of wooden houses. Copyright © 2006 IFAC.
  • No Thumbnail Available
    Item
    Performance comparison of three different controllers for proton exchange membrane fuel cell
    (2015-01-01) Fan L.; Li C.; Boshnakov K.
    Proton exchange membrane fuel cells (PEMFCs) are promising clear and efficient new energy sources. An excellent control system is a normal working prerequisite for maintaining a fuel cell system in correct operating conditions. Conventional controllers could not satisfy the high performance to obtain the acceptable responses because of uncertainty, time-change, nonlinear, long-hysteresis and strong-coupling characteristics of PEMFCs. Based on the dynamic model of PEMFC, an adaptive fuzzy sliding mode controller is proposed for PEMFC to realize constant voltage output and reliability service. Three different controllers, including fuzzy controller, fuzzy sliding mode controller and adaptive fuzzy sliding mode controller, are designed and compared. Simulation results show that the proposed adaptive fuzzy sliding mode controller for PEMFC can get satisfactory control effects.
  • No Thumbnail Available
    Item
    SUSTAINABLE VOLTAGE REUTILIZATION OF A MICROBIAL FUEL CELL OF A LOW ORGANIC LOAD USING pH BUFFER SOLUTION INJECTION
    (2017-01-01) Li C.; Boshnakov K.; Fan L.
    Microbial fuel cells are obtaining increased attention in wastewater treatment technology because of provision of effective treatment in presence of a low organic load through continuous electrical power supply. This paper studies the voltage reutilization performance of a microbial fuel cell using recycled wastewater from its treatment process as an anodic fuel. The experimental results show that a suitable pH buffer solution injection can provide a desirable output voltage response and advanced treatment.