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**Type of paper**:*Paper in journal*

**Title:**The mathematical model of the steam generator combustion chamber

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Journal**: Automatika

**Number**: 3

**ISSN**: 0005-1144

**Volume**: 33

**Year**: 1992

**Pages**: from 93 to 97

**Number of references**: 10

**Language**: engleski

**Keywords**: mathematical modeling, steam generator furnace

**Type of paper**:*Paper in journal*

**Title:**Prediction of once-through boiler steady states and dynamics in sliding pressure regime by simulation

**Authors:**- Šerman, Nikola (46501.00000)

**Journal**: Automatika

**Number**: 3

**ISSN**: 0005-1144

**Volume**: 33

**Year**: 1992

**Pages**: from 99 to 104

**Number of references**: 4

**Language**: engleski

**Type of paper**:*Paper in journal*

**Title:**Influence of spatial discretization on the results of the distributed parameters plant control simulation

**Authors:**- Šerman, Nikola (46501.00000)

**Journal**: Automatika

**Number**: 1

**ISSN**: 0005-1144

**Volume**: 34

**Year**: 1993

**Pages**: from 67 to 72

**Number of references**: 5

**Language**: engleski

**Type of paper**:*Paper in journal*

**Title:**Flow velocities computation inside a complexly shaped furnace with boundary condition approximation

**Authors:**- Martinis, Vinko (29004.00000)
- Novko, Igor (184335.00000)

**Journal**: Automatika

**Number**: 1

**ISSN**: 0005-1144

**Volume**: 34

**Year**: 1993

**Pages**: from 73 to 76

**Number of references**: 2

**Language**: hrvatski

**Summary**: The application of nonperpendicular nets usual computing numerical problems with two-dimensional domain in three-dimensional cases leads to serious difficulties when transferring real nets into numerically perpendicular ones. In this paper a perpendicular net relevant to furnace volume is retained so that differential equations discretisation is standard. As nodal points do not always fall into domain's boundary the approximation of boundary conditions is carried out at domain's nodal points that are closest to the boundary. That way a three-dimensional problem does not really differ from a two-dimensional problem. Such an approach is applicable with other methods od discretisation and equation system computation. In this paper a numerical solution of mathematicam model of a complexly shaped furnace found by numerical compression method is shown.

**Type of paper**:*Paper in journal*

**Title:**Heat transfer calculation of the furnace with a two-dimensional mathematical model

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Journal**: Zbornik radova Fakulteta strojarstva i brodogradnje Sveučilišta u Zagrebu

**ISSN**: 0350-3097

**Volume**: 16

**Year**: 1992

**Pages**: from 197 to 204

**Number of references**: 6

**Language**: hrvatski

**Summary**: Using a two-dimensional mathematical model, the calculation of an oil fired 330 t/h steam generator combustion chamber is carried out. The calculation gives gas velocity, fuel and oxygen concentration and temperature fields inside the furnace, as well as the distribution of heat fluxes along the furnace walls. The simulation of the furnace behavior under steady-state condition is performed in the range of 50-100 % load. The results are very favorably compared with the data supplied by the steam generator manufacturer.

**Type of paper**:*Paper in journal*

**Title:**Aplication of multigrid correction method on flow calculation in a steam generator

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Journal**: Zbornik radova Fakulteta strojarstva i brodogradnje Sveučilišta u Zagrebu

**ISSN**: 0350-3097

**Volume**: 17

**Year**: 1993

**Pages**: from 147 to 154

**Number of references**: 6

**Language**: hrvatski

**Summary**: In this paper the rate of convergence of the multigrid method with additive corrections when solving the two-dimensional mathematical model of the steam generator combustion chamber is analyzed. The mathematical model is represented by the system of strongly nonlinear partial differential equations. The solution of the mathematical model is obtained by the global iterative procedure. In one global iteration the system of equations of one variable is solved by applying line Gauss-Seidel iterative procedure. A great improvement in convergence is achieved by applying the multigrid method with additive corrections in solving mathematical model of the combustion chamber.

**Type of paper**:*Paper in journal*

**Title:**Solar thermal power plants on the way to commercialization

**Authors:**- Duić, Neven (179672.00000)

**Journal**: Sunčeva energija

**Number**: 2

**ISSN**: 0351-2797

**Volume**: 14

**Year**: 1993

**Pages**: from 61 to 68

**Number of references**: 8

**Language**: hrvatski

**Summary**: The paper analyses development of solar thermal power plants during last ten years. The question of commercial utilization of such plants is highlighted. Several most important types of such plants are discussed: central receiver system, parabolic through system, solar pond system all the way to the modular solar power plants for isolated consumers. Different solar thermal systems are compared to the conventional thermal power plants by means of cost analyses.

**Keywords**: solar thermal, central receiver, parabolic through, solar pond

**Type of paper**:*Paper in proceedings*

**Title:**Examination of once through boiler control strategy by simulation

**Authors:**- Šerman, Nikola (46501.00000)
- Mavračić, Krešimir

**Editors**- El Moudni, A.
- Borne, P
- Tzafestas, S.G.

**Proceedings title**: Proceedings of IMACS MCTS 91

**Language**: engleski

**Place**: Lille, Francuska

**Year**: 1991

**ISBN/ISSN**: 29502908-1-7

**Pages**: from 349 to 354

**Meeting**: IMACS IFAC Symposium on Modeling and Control of Technological Systems

**Held**: from 05/07/91 to 05/10/91

**Type of paper**:*Paper in proceedings*

**Title:**Contribution to investigation of variable area flowmeter

**Authors:**- Bogdan, Željko (4210.00000)

**Editors**- Galaso, Ivan

**Proceedings title**: Proceedings of INTERKLIMA 91

**Language**: engleski

**Place**: Zagreb

**Year**: 1991

**Pages**: from 233 to 239

**Meeting**: INTERKLIMA 91, 11th International Symposium of Heating, Refrigareting and Air Conditioning

**Held**: from 06/12/91 to 06/13/91

**Type of paper**:*Paper in proceedings*

**Title:**The mathematical model of a steam accumulator

**Authors:**- Duić, Neven (179672.00000)

**Editors**- Galaso, Ivan

**Proceedings title**: Proceedings of INTERKLIMA 91

**Language**: engleski

**Place**: Zagreb

**Year**: 1991

**Pages**: from 249 to 256

**Meeting**: INTERKLIMA 91, 11th International Symposium of Heating, Refrigareting and Air Conditioning

**Held**: from 06/12/91 to 06/13/91

**Other**: Zbornik radova nema ISBN.

**Type of paper**:*Paper in proceedings*

**Title:**Prediction of once through boiler steady states and dynamics in sliding pressure regime by simulation

**Authors:**- Šerman, Nikola (46501.00000)

**Editors**- Kecman, Vojislav

**Proceedings title**: Zbornik radova KoREMA 37

**Language**: engleski

**Place**: Zagreb

**Year**: 1992

**ISBN/ISSN**: 86-81571-11-7

**Pages**: from 85 to 89

**Meeting**: 37. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/92 to 04/29/92

**Type of paper**:*Paper in proceedings*

**Title:**The mathematical model of the steam generator combustion chamber

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Editors**- Kecman, Vojislav

**Proceedings title**: Zbornik radova KoREMA 37

**Language**: engleski

**Place**: Zagreb

**Year**: 1992

**ISBN/ISSN**: 86-81571-11-7

**Pages**: from 77 to 80

**Meeting**: 37. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/92 to 04/29/92

**Keywords**: mathematical modeling, steam generator furnace

**Type of paper**:*Paper in proceedings*

**Title:**The mathematical model of the production of carbon dioxide and sulphur dioxide in the steam generator furnace

**Authors:**- Duić, Neven (179672.00000)
- Bogdan, Željko (4210.00000)

**Editors**- Franković, Bernard

**Proceedings title**: Zbornik radova XIII. Međunarodnog kongresa Energija i zaštita čovjekove okoline

**Language**: hrvatski

**Place**: Opatija

**Year**: 1992

**ISBN/ISSN**: 86-81601-01-8

**Pages**: from 255 to 262

**Meeting**: XIII. Međunarodni kongres Energija i zaštita čovjekove okoline

**Held**: from 10/28/92 to 10/30/92

**Summary**: The two-dimensional mathematical model of processes inside the furnace is described with special attention given to the production of carbon dioxide and sulfur dioxide. The model consists differential equations of continuity, impulse, enthalpy and transport of chemical species, which are discretized by control volume scheme. Two optional models are applied: oil firing and natural gas firing. The source terms in the transport equations of species are modeled by the Arrhenius law of reaction rate. The resulting distributions of combustion products for oil model of combustion is shown and compared with the experimental results.

**Keywords**: mathematical model, furnace

**Type of paper**:*Paper in proceedings*

**Title:**Numerical computation of threedimensional flow models inside a furnace by the PISO method

**Authors:**- Martinis, Vinko (29004.00000)

**Editors**- Kecman, Vojislav

**Proceedings title**: Zbornik radova KoREMA 37

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1992

**ISBN/ISSN**: 86-81571-11-7

**Pages**: from 81 to 84

**Meeting**: 37. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/92 to 04/29/92

**Summary**: Computing furnace temperature field is divided into thermal and fluid flow parts. This enables separate study of fluid flows with a quick transient process. In this paper the numerical computation of steady-state flows by unstationary threedimensional nonlinear fluid flow model is shown. The stability and the second order accurancy in spatial coordinates are achieved by implicit discretisation of time derivative. Moreover, the quick transient process with the use of PISO method for sloving discretised equations significantly reduces calculation scope.

**Type of paper**:*Paper in proceedings*

**Title:**Influence of spatial discretiyation on the results of the distributed parameters plant control

**Authors:**- Šerman, Nikola (46501.00000)

**Editors**- Novaković, Branko

**Proceedings title**: Zbornik radova KoREMA 38

**Language**: engleski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 953-6037-00-9

**Pages**: from 471 to 475

**Meeting**: 38. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/93 to 04/28/93

**Type of paper**:*Paper in proceedings*

**Title:**The three-dimensional mathematical model of the horizontal furnace

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Editors**- Kalpić, Damir

**Proceedings title**: Zbornik radova KoREMA 38

**Language**: engleski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 953-6037-00-9

**Pages**: from 584 to 587

**Meeting**: 38. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/93 to 04/28/93

**Summary**: International Flame Research Foundation experimental furnace in IJmuiden (Netherlands) is modeled by the three-dimensional mathematical model, in order to check the results of simulation against the measured ones. The furnace is horizontal with nearly square cross-section. Holes for positioning of measuring equipment are placed on side walls. The mathematical model of the furnace includes fluid flow processes with recirculation of combustion products, combustion of oil, radiation heat transfer as well as transport of fuel and combustion products through the inside of the furnace. Calculated temperature field is compared to the experimental data with satisfactory agreement.

**Type of paper**:*Paper in proceedings*

**Title:**Numerical simulation of air-flow in a heated room

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Editors**- Galaso, Ivan

**Proceedings title**: Proceedings of INTERKLIMA 93

**Language**: engleski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 953-6037-01-7

**Pages**: from 7 to 12

**Meeting**: INTERKLIMA 93, 12th International Symposium of Heating, Refrigerating and Air-conditioning

**Held**: from 06/09/93 to 06/11/93

**Summary**: In this paper the three-dimensional numerical simulation of air-flow induced by heating body in a room is presented. The mathematical model consists of partial differential equations of mass conservation and transport of momentum and energy. Evaluation of numerical model is based on control volume approach. The mathematical model is tested against analytical solution which exists for cavity with heated and cooled vertical walls with very good agreement. Demonstration calculation is also presented for a room heated by a radiator and cooled through windows and the walls. Results are presented in the form of cross-sectional views of velocity and temperature fields.

**Type of paper**:*Paper in proceedings*

**Title:**Three-dimensional simulation of the combustion process in an oil-fired furnace

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Editors**- Čerić, Vlatko
- Hljuz-Dobrić, Vesna

**Proceedings title**: Proceedings of ITI 93

**Language**: engleski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 1330-1012

**Pages**: from 351 to 356

**Meeting**: 15th International Conference on Information Technology Interfaces

**Held**: from 06/15/93 to 06/18/93

**Summary**: In this paper the three-dimensional numerical simulation of the fuel combustion, flue gas flow and radiation heat transfer in an oil fired furnace is presented. The mathematical model of oil-combustion is fully empirical, based on experimental data. The flue gas flow model is described by partial differential equations of mass, momentum and energy conservation. The simplification of zone method is used for radiation heat transfer modelling. Evaluation of numerical discretization is based on the control volume approach. Sensitivity analysis of the grid refinement in the range of 5000 to 17500 control volumes is carried out.

**Type of paper**:*Paper in proceedings*

**Title:**Flow velocities computation inside a complexly shaped furnace with boundary condition approximation

**Authors:**- Martinis, Vinko (29004.00000)
- Novko, Igor (184335.00000)

**Editors**- Kalpić, Damir

**Proceedings title**: Zbornik radova KoREMA 38

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 953-6037-00-9

**Pages**: from 297 to 303

**Meeting**: 38. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/93 to 04/28/93

**Summary**: The application of nonperpendicular nets usual computing numerical problems with two-dimensional domain in three-dimensional cases leads to serious difficulties when transferring real nets into numerically perpendicular ones. In this paper a perpendicular net relevant to furnace volume is retained so that differential equations discretisation is standard. As nodal points do not always fall into domain's boundary the approximation of boundary conditions is carried out at domain's nodal points that are closest to the boundary. That way a three-dimensional problem does not really differ from a two-dimensional problem. Such an approach is applicable with other methods od discretisation and equation system computation. In this paper a numerical solution of mathematicam model of a complexly shaped furnace found by numerical compression method is shown.

**Type of paper**:*Paper in proceedings*

**Title:**Description of two-phase flow test loop with forced circulation

**Authors:**- Firak, Mihajlo (12003.00000)

**Editors**- Boršić, Mladen
- Mahović, Sanjin

**Proceedings title**: Zbornik radova KoREMA 38

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 953-6037-00-9

**Pages**: from 297 to 303

**Meeting**: 38. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/93 to 04/28/93

**Summary**: An experimental set-up for research of thermohydraulical phenomena with diabatic forced flow of one component two-phase water flow has been built at Thermal Power Plants Laboratory of the Faculty of Mechanical Engineering and Naval Architecture, Zagreb. Basically, this loop represents monotube steam generator with forced flow (0.5 - 4)x10-2 kg/s, at working pressure between 20 and 200 bar and superheated steam temperature up to 550 řC. Preheater and evaporating tube heating (and consequently medium heating) is done electrically by conduction of electric power through the wall of the tube. Maximum electric power of the test loop is 100 kW. By properly selected electric parameters (i.e. current and voltage), tube materials, tube dimensions and process parameters, (flow, pressure and temperature), it is possible to ensure various two-phase flow thermohydraulical phenomena. Incorporated sensors of electric and process parameters, connected together with computer aided data acquisition and processing system allow monitoring and analysis of the experiments. This paper presents basic components of the test loop, and as an illustration of its experimental abilities, a graphical presentation of certain system transients during suffocation of output valve with steam.

**Keywords**: two-phase flow, experimental set-up, thermohydraulical phenomena

**Type of paper**:*Paper in proceedings*

**Title:**Protecting infuction turbine flowmeter from elektromagnetic interference

**Authors:**- Firak, Mihajlo (12003.00000)
- Jakovljević, Žarko (171432.00000)

**Editors**- Boršić, Mladen
- Mahović, Sanjin

**Proceedings title**: Zbornik radova KoREMA 38

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 953-6037-00-9

**Pages**: from 321 to 327

**Meeting**: 38. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/93 to 04/28/93

**Summary**: Induction turbine flowmeter for water is incorporated into laboratory experimental set-up for researching thermohydraulic phenomena of diabatic two-phase forced flow. After passing through the flowmeter, water is heated in the monotube preheater by means of Joule's heat which is developed in the tube wall. Three-phase transformer with maximal power of 63 kW has the output parameters 1500 A and 16 V max. Transformer, preheater and connecting cables are all together very strong source of electromagnetic field. This field induces parasitic alternating voltage in the coil of induction turbine flowmeter which is superposed to the voltage formed due to the certain flow. Resulting output voltage carries both disturbance and information about flow, where disturbance can be stronger. The paper presents simple experimental/analytical way for approximate determination the strength of disturbation source alternating magnetic field in a certain point of space. The results of shielding factor experimental evaluation for six different shields, which protect induction turbine flowmeter from electromagnetic interference, are also presented.

**Keywords**: protecting induction turbine flowmeter from electromagnetic interference

**Type of paper**:*Paper in proceedings*

**Title:**Computer-aided processing of measurement data collected on two-phase flow test loop

**Authors:**- Jakovljević, Žarko (171432.00000)
- Firak, Mihajlo (12003.00000)

**Editors**- Čerić, Vlatko
- Hljuz-Dobrić, Vesna

**Proceedings title**: Proceedings of ITI 93

**Language**: engleski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 1330-1012

**Pages**: from 45 to 48

**Meeting**: 15th International Conference on Information Technology Interfaces

**Held**: from 06/15/93 to 06/18/93

**Summary**: An experimental two-phase flow test loop has been built at Thermal Power Plants Laboratory of Faculty of Mechanical Engineering and Naval Architecture, Zagreb. Short description of facility is given and its role in educational process is explained. Measurement data collected on this loop are processed with MATLAB software package. Description of developed algorithms is given and advantages of their application for educational purposes are stated.

**Keywords**: experimental facility, signal processing, MATLAB, education

**Type of paper**:*Paper in proceedings*

**Title:**Measuring velocity and temparature fields in industrial and experimental furnaces

**Authors:**- Slavica, Željko (146131.00000)

**Editors**- Boršić, Mladen
- Mahović, Sanjin

**Proceedings title**: Zbornik radova KoREMA 38

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 953-6037-00-9

**Pages**: from 432 to 436

**Meeting**: 38. Međunarodni godišnji skup KoREMA

**Held**: from 04/26/93 to 04/28/93

**Summary**: The review of papers published during last 30 years is presented covering measurement of velocity and temperature fields in furnaces. Difference is made between measurements on industrial steam generator furnaces and measurements on experimental furnace models in laboratory conditions. Measuring equipment used in experiments is specified, and problems that showed up with some parts of equipment during measurement are also stated.

**Type of paper**:*Paper in proceedings*

**Title:**Mathematical model of the gas-fired furnace

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Proceedings title**: II. kolokvij Modeliranje u znanosti, tehnici i društvu, CROSS 92

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1992

**Meeting**: II. kolokvij Modeliranje u znanosti, tehnici i društvu, CROSS 92

**Held**: from 12/11/92 to 12/11/92

**Other**: Zbornik je u tisku.

**Type of paper**:*Paper in proceedings*

**Title:**Water level control in the high pressure feedwater preheaters of the utility power block

**Authors:**- Šerman, Nikola (46501.00000)

**Editors**- Štambuk-Boršić, Neda

**Proceedings title**: Zbornik radova KoREMA 39

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1994

**ISBN/ISSN**: 953-6037-02-5

**Pages**: from 315 to 318

**Meeting**: 39. Međunarodni godišnji skup KoREMA

**Held**: from 04/25/94 to 04/27/94

**Summary**: Water level control strategy for the high-pressure feed water preheaters of the 320 MW utility power block is proposed. By proposing a new control system design in order to overcome functional shortcomings of the existing local controllers, the particularities of the regenerative feed water preheating system of the plant under consideration have been respected. The proposed control system is expected to ensure fully automatic water level control under all operational conditions of the H.P. preheater cascade. The basic functional characteristics of the partial technical solutions have been examined by use of simplified preheater models. Quantitative estimation of the achievable control quality within the preheater cascade under different operational conditions was performed by simulation of the thermohydraulic model coupled with the control system model.

**Type of paper**:*Paper in proceedings*

**Title:**Modeling and simulation of 320 MW thermal power block feedwater heating system

**Authors:**- Lončar, Dražen (197152.00000)
- Šerman, Nikola (46501.00000)

**Editors**- Štambuk-Boršić, Neda

**Proceedings title**: Zbornik radova KoREMA 39

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1994

**ISBN/ISSN**: 953-6037-02-5

**Pages**: from 264 to 268

**Meeting**: 39. Međunarodni godišnji skup KoREMA

**Held**: from 04/25/94 to 04/27/94

**Summary**: The mathematical model of the thermohydraulic processes in the line of feedwater heaters has been developed . The control volume approach and the implicit time domain discretization have been used to find model's solution in each time step. Thus the system of differential equations has been reduced to a system of nonlinear algebraic equations and solved by the numerical procedure based on Newton-Raphson's method. The influence of the different operational states on condensate flows has been estimated by simulation. The simulation's results have been used for verification of the proposed control system design.

**Type of paper**:*Paper in proceedings*

**Title:**Open flow boundary conditions at furnace exit in flow computation

**Authors:**- Martinis, Vinko (29004.00000)
- Slavica, Željko (146131.00000)

**Editors**- Kalpić, Damir

**Proceedings title**: Zbornik radova KoREMA 39

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1994

**ISBN/ISSN**: 953-6037-02-5

**Pages**: from 455 to 459

**Meeting**: 39. Međunarodni godišnji skup KoREMA

**Held**: from 04/25/94 to 04/27/94

**Summary**: Since flow velocities at industrial furnace exit are unknown, it is difficult to define outflow boudary conditions in numerical computation of partial differential equations governing fluid flow. In the present paper the open flow boundary conditions are determined with a relatively small extension of domain in the direction of outflow. The flow equations are discretized by the finite-difference method, and the system of equations is solved using the PISO method (Pressure-Implicit with Splitting of Operators). The estimation of required domain extension is given in order to determinate approximate fluid flow velocities at furnace exit.

**Type of paper**:*Paper in proceedings*

**Title:**Simulation of oil heater control loop dynamics

**Authors:**- Lončar, Dražen (197152.00000)

**Editors**- Čerić, Vlatko
- Hljuz-Dobrić, Vesna

**Proceedings title**: Proceedings of ITI 93

**Language**: engleski

**Place**: Zagreb

**Year**: 1993

**ISBN/ISSN**: 1330-1012

**Pages**: from 61 to 64

**Meeting**: 15th International Conference on Information Technology Interfaces

**Held**: from 06/15/93 to 06/18/93

**Summary**: The paper deals with an educational demo-example, based on the real-life control problem - the problem of the fuel temperature control, commonly appearing in oil-fired thermal power blocks. Mathematical model of the oil-heater has been developed and implemented in MATLAB1 in order to be used as an object in illustrations of the simulation technique itself and for further control-related investigations performed by students. The model of the oil heater is briefly decsribed and some simulation results are presented.

**Keywords**: modeling, simulation, MATLAB, education

**Type of paper**:*Paper in proceedings*

**Title:**Mathematical modelling and simulation of the 320MW thermal power block

**Authors:**- Bogdan, Željko (4210.00000)

**Editors**- Štambuk-Boršić, Neda

**Proceedings title**: Zbornik radova KoREMA 39

**Language**: hrvatski

**Place**: Zagreb

**Year**: 1994

**ISBN/ISSN**: 953-6037-02-5

**Pages**: from 380 to 383

**Meeting**: 39. Međunarodni godišnji skup KoREMA

**Held**: from 04/25/94 to 04/27/94

**Summary**: In this paper the mathematical model which describes thermodynamic behavior of the conventional thermal power plant for electricity generation is presented. The mathematical model consists of the three main parts: the steam generator model, the turbine model and the model of regenerative feedwater heaters. The steam generator thermodynamic model is based on the "normative" method. The mathematical model is used for simulation of steady-state operation of the thermal power plant Rijeka. Performance of the thermal power plant influenced by lowering of steam generator feedwater inlet temperature due to accident closing of high pressure water heaters is simulated. Good agreement of temperature profiles along water-steam and flue gas-air tracts as well as water and steam flow rates with power plant measured data is achieved.

**Type of paper**:*Paper in proceedings*

**Title:**Modeling of the high-temperature dissociation of CO2 in the steam generator furnace

**Authors:**- Duić, Neven (179672.00000)
- Bogdan, Željko (4210.00000)

**Editors**- Čerić, Vlatko
- Hljuz-Dobrić, Vesna

**Proceedings title**: Proceedings of ITI 94

**Language**: engleski

**Place**: Zagreb

**Year**: 1994

**ISBN/ISSN**: 1330-1012

**Pages**: from 265 to 270

**Meeting**: 16th International Conference on Information Technology Interfaces

**Held**: from 06/14/94 to 06/17/94

**Summary**: While simulating combustion and heat transfer processes in the steam generator furnace by the three-dimensional mathematical model, local temperature maximums considerably exceeded values obtained by measurement. It is caused partially by applied model of combustion kinetics and partially by the dissociation of three-atom flue gases. The CO2 dissociation influence becomes notable already at 1500C, which means it influences the processes in the furnace. The CO2 dissociation is modeled by the assumption of a local equilibrium. Since as one of the products of the dissociation is CO, the transport equation of carbon monoxide is introduced. Together with the fuel oxidation model, the entire combustion model includes four differential transport equations for following chemical species: fuel, O2, CO2 and CO. In the paper the influence of CO2 dissociation on the temperature field in the oil-fired steam generator furnace is shown. The influence is significant in high-temperature regions where perceptible decrease of maximal temperatures is observed.

**Keywords**: carbon dioxide dissociation, numerical simulation, steam generator furnace

**Type of paper**:*Paper in proceedings*

**Title:**Prediction of the thermal radiation heat transfer in a furnace by Monte Carlo zone method

**Authors:**- Bogdan, Željko (4210.00000)
- Schneider, Daniel Rolph
- Duić, Neven (179672.00000)

**Editors**- Čerić, Vlatko
- Hljuz-Dobrić, Vesna

**Proceedings title**: Proceedings of ITI 94

**Language**: engleski

**Place**: Zagreb

**Year**: 1994

**ISBN/ISSN**: 1330-1012

**Pages**: from 253 to 258

**Meeting**: 16th International Conference on Information Technology Interfaces

**Held**: from 06/14/94 to 06/17/94

**Summary**: The mathematical model of radiation heat transfer based on the Monte Carlo method is developed and tested on a simple case of radiation in a cubical enclosure for which numerical solution is available. Number of emitted energy bundles in a sample is varied in order to establish its influence on the final solution. Different averaging techniques are tried in an attempt of decreasing the magnitude of the temperature fluctuations during iterations which are the consequence of the stochastic nature of the method. Basically the same mathematical model with the additional provision for fuel heat generation is used for calculating radiation heat transfer in a steam generator furnace. Results are shown in the form of distributions of heat flux densities and temperatures in the furnace and on its walls.

**Keywords**: Monte Carlo method, radiation heat transfer, numerical simulation

**Type of paper**:*Paper in proceedings*

**Title:**Zone boiler furnace calculation

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Editors**- Galaso, Ivan
- Iljaš, Branko
- Jakšić, Smiljko
- Šimunović, Ante
- Švaić, Srećko

**Proceedings title**: Zbornik radova Energetska i procesna postrojenja

**Language**: hrvatski

**Place**: Hrašće

**Year**: 1994

**Pages**: from 165 to 169

**Meeting**: Energetska i procesna postrojenja

**Held**: from 05/25/94 to 05/27/94

**Keywords**: furnace, zone method, mathematical modeling

**Other**: Zbornik radova nema ISBN.

**Type of paper**:*Paper in proceedings*

**Title:**Leakage detection in power plant boiler

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)
- Schneider, Daniel Rolph
- Šerman, Nikola (46501.00000)
- Afgan, Naim

**Editors**- Reis, Albino

**Proceedings title**: Proceedings of 3rd European Conference on Industrial Furnaces and Boilers

**Language**: engleski

**Place**: Lisabon, Portugal

**Year**: 1995

**Meeting**: 3rd European Conference on Industrial Furnaces and Boilers

**Held**: from 04/18/95 to 04/21/95

**Summary**: The paper deals with the feasibility of using the radiation heat flux measurement as the diagnostic variable for the tube leakage detection system. The mathematical model based on the Monte Carlo zone method is used to investigate sensitivity of the radiative heat flux changes due to the water leakage into the furnace. Control volume based mathematical model is used to determine temperature, velocity and concentration fields. Radiative properties are determined by the three gray gases model. It was shown that the heat flux might be sufficiently sensitive diagnostic variable to be used in on-line monitoring of the large power plant boiler.

**Keywords**: boiler tube leakage, Monte Carlo method, numerical simulation, mathematical modeling, combustion chamber

**Other**: Zbornik nije numeriran i nema ISBN.

**Type of paper**:*Paper in proceedings*

**Title:**Tube leakage effect on radiation heat flux in boiler

**Authors:**- Duić, Neven (179672.00000)
- Bogdan, Željko (4210.00000)
- Schneider, Daniel Rolph
- Šerman, Nikola (46501.00000)
- Afgan, Naim

**Language**: engleski

**Year**: 1995

**Meeting**: ICHMT International Symposium on Radiative Heat Transfer

**Held**: from 08/14/95 to 08/18/95

**Summary**: Early diagnostics of tube leakage in a furnace would help in preventing the failure by planning maintenance. In the vicinity of the tube leakage the concentration of water vapor is increased and heat flux density distribution on the furnace wall changed. The degree of change is measure of the incident. The Monte Carlo zone method based mathematical model was developed in order to enable that analysis. The three-dimensional mathematical model describes steady-state behavior of the steam generator furnace. It was shown that the radiative heat flux is sufficiently sensitive to detect the water leakage into the furnace.

**Keywords**: boiler tube leakage detection, Monte Carlo method, combustion chamber

**Other**: Konačna verzija Zbornika radova u tisku. Preliminarna verzija, zbornik sažetaka nema ISBN.

**Type of paper**:*Paper in proceedings*

**Title:**Examination of the water level control strategy for the feed water preheaters of the 320 MW utility power blok by computer simulation

**Authors:**- Šerman, Nikola (46501.00000)
- Lončar, Dražen (197152.00000)

**Editors**- Galaso, Ivan
- Iljaš, Branko
- Jakšić, Smiljko
- Šimunović, Ante
- Švaić, Srećko

**Proceedings title**: Zbornik radova Energetska i procesna postrojenja

**Language**: hrvatski

**Place**: Hrašće

**Year**: 1994

**Pages**: from 446 to 453

**Meeting**: Energetska i procesna postrojenja

**Held**: from 05/25/94 to 05/27/94

**Summary**: The new control system for the high pressure feed water preheaters has been designed in order to overcome functional shortcomings of the existing local controllers. The proposed control system is expected to ensure fully automatic water level control under all operational conditions. Quantitative estimation of the acheivable control quality within the preheater cascade under different operational conditions was performed by simulation of the termohydraulic model coupled with control system model.

**Keywords**: feedwater preheaters, level control, simulation

**Other**: Zbornik radova nema ISBN.

**Type of paper**:*Paper in proceedings*

**Title:**Calculation of NOx production in a large steam generator combustion chamber

**Authors:**- Bogdan, Željko (4210.00000)

**Editors**- Franković, Bernard

**Proceedings title**: Zbornik radova XIV. Međunarodnog kongresa Energija i zaštita okoliša

**Language**: engleski

**Place**: Opatija

**Year**: 1994

**ISBN/ISSN**: 953-96054-3-1

**Pages**: from 27 to 33

**Meeting**: XIV. Međunarodni kongres Energija i zaštita okoliša

**Held**: from 10/26/94 to 10/28/94

**Summary**: In this paper the mathematical model of steady state thermodynamic processes inside a 1000 t/h steam generator is presented. It is a lumped model based on the "normative" design method. In the combustion chamber model the enhanced Zeldovich mechanism for thermal NO calculation is incorporated. Calculation results of the temperature profiles along water-vapor, flue gas and air tracts are successfully compared with measurements data. Results of NOx calculations are shown graphically for three different power plant loads.

**Keywords**: NOx production, mathematical modelling, steam generator

**Type of paper**:*Paper in proceedings*

**Title:**Steam generator design based on mathematical modelling

**Authors:**- Bogdan, Željko (4210.00000)

**Editors**- Kalpić, Damir
- Hljuz-Dobrić, Vesna

**Proceedings title**: Proceedings of ITI 95

**Language**: engleski

**Place**: Zagreb

**Year**: 1995

**ISBN/ISSN**: 1330-1012

**Pages**: from 419 to 424

**Meeting**: 17th International Conference on Information Technology Interfaces

**Held**: from 06/13/95 to 06/16/95

**Summary**: A mathematical model for the water-tube type of the steam generator is developed. The model has provisions for different types of heat exchange surfaces. Uniform inputs and outputs of the models of these surfaces enable easy inclusion into the main model where the configuration of steam generator is defined. The mathematical model is one-dimensional with heat exchange surfaces being nods of the system. The model is used as an auxiliary tool in upgrading design of the steam generator for fast steam production.

**Type of paper**:*Paper in proceedings*

**Title:**Modeling of a solid fuel combustion chamber of a ramjet using a multi-block domain decomposition technique

**Authors:**- Coelho, Pedro J.
- Duić, Neven (179672.00000)
- Lemos, C.
- Carvalho, Maria da Gra‡a

**Language**: engleski

**Year**: 1996

**Meeting**: 34th Aerospace Sciences Meeting

**Held**: from 01/15/96 to 01/18/96

**Other**: Rad je prihvaćen za objavljivanje.

**Type of paper**:*M.A.*

**Title:**Computer-aided experiment supervision and data acquiring and processing on the experimental evaporator

**Faculty**: Fakultet strojarstva i brodogradnje Sveučilište u Zagrebu

**Date of defense**: 03/18/93

**Language**: hrvatski

**Number of pages**: 105

**Type of paper**:*M.A.*

**Title:**Three-dimensional mathematical model of the processes in the steam generator furnace

**Faculty**: Fakultet strojarstva i brodogradnje Sveučilište u Zagrebu

**Author**: DUIĆ NEVEN

**Date of defense**: 07/14/93

**Language**: hrvatski

**Number of pages**: 121

**Type of paper**:*Mentorship*

**Title:**Computer-aided experiment supervision and data acquiring and processing on the experimental evaporator

**Faculty**: Fakultet strojarstva i brodogradnje Sveučilište u Zagrebu

**Mentor**: ŠERMAN NIKOLA

**Date of defense**: 03/18/93

**Number of pages**: 105

**Author**: Jakovljević mr.sc. Žarko

**Degree level**: M.A.

**Summary**: In order to investigate thermohydraulical phenomena in two-phase diabatic flow, a laboratory once-through evaporator with electrically heated tube wall has been built. Subject of this work is realization of computer-aided experiment supervision and computer-aided data acquiring and processing by means of HP 9000/320 computer system and HP 3852A Data Acquisition/Control Unit. Experimental loop and its functioning have been described. Characteristics of measuring equipment and computer system have been stated. Operating conditions supervision demands and loop protection demands have been defined. Some basic theoretical concepts needed for successful organizing of measurement data acquisition have been presented (time-domain and frequency-domain description of system parameters). Various possibilities of data acquiring and storing by means of available computer system have been considered. Special software has been designed for operating conditions supervision, loop protection and data acquisition. Its structure has been described and explained in details. Program's basic mode and special modes have been described, and the role of each computer system component in accomplishing aforesaid tasks has been explained. Basic theoretical concepts of signal processing have been introduced, while problems related with choosing data processing hardware and software have been mentioned. Various algorithms for data processing have been developed and their application has been illustrated on few chosen samples from experimental loop

**Keywords**: data acquisition, signal processing, software, MATLAB, HP 3852A, experimental, evaporator

**Type of paper**:*Mentorship*

**Title:**Three-dimensional mathematical model of the processes in the steam generator furnace

**Faculty**: Fakultet strojarstva i brodogradnje Sveučilište u Zagrebu

**Mentor**: BOGDAN ŽELJKO

**Date of defense**: 07/14/93

**Number of pages**: 121

**Author**: Duić mr.sc Neven

**Degree level**: M.A.

**Summary**: Three-dimensional mathematical model of the steam generator combustion chamber is presented. The model is mathematically represented by the system of nonlinear elliptic partial differential equations of the second order. It contains the flow of air, fuel and flue gas, the combustion process, transport of oil, gas and oxygen, heat transfer inside the gas chamber and radiative and convective heat transfer between gas and furnace walls. The combustion process is represented by the summary reaction modelled by the Arrhenius' reaction rate equation. Radiative heat transfer is modelled by the zone method simplified with the assumptions of black walls, constant absorption coefficient and one gray gas. For the transformation of differential equations to algebraic, control volume (SIMPLER) scheme is applied. The solving procedure is accelerated by the multigrid method. As a global solution algorithm the iterative modification of PISO is applied. Code ZONAL was developed in order to examine the latter model. Comparison between the available experimental data and the calculated results has shown good agreement.

**Type of paper**:*Survey/Study*

**Title:**Efects evaluation of sliding pressure operating regime in the 210 MW blocks TE Sisak with the reconstructed steam generators

**Authors:**- Šerman, Nikola (46501.00000)
- Bogdan, Željko (4210.00000)

**Ordering party**: Hrvatska elektroprivreda HEP

**Institution depot**: FSB-Zagreb

**Year**: 1991

**Number of pages**: 44

**Type of paper**:*Survey/Study*

**Title:**Air flow simulation through the nuclear power plant Krško cooling towers

**Authors:**- Bogdan, Željko (4210.00000)

**Ordering party**: Hrvatska elektroprivreda HEP

**Institution depot**: FSB-Zagreb

**Year**: 1991

**Number of pages**: 29

**Type of paper**:*Survey/Study*

**Title:**Heat flux distribution in the gas fired steam generator furnace X-571 A/B

**Authors:**- Bogdan, Željko (4210.00000)
- Duić, Neven (179672.00000)

**Ordering party**: INA-Etilen

**Institution depot**: FSB-Zagreb

**Year**: 1992

**Number of pages**: 75

**Type of paper**:*Survey/Study*

**Title:**Design proposal of high pressure feedwater heater control in the 320 MW plant Rijeka

**Authors:**- Šerman, Nikola (46501.00000)
- Bogdan, Željko (4210.00000)
- Lončar, Dražen (197152.00000)

**Ordering party**: Hrvatska elektroprivreda HEP

**Institution depot**: FSB-Zagreb

**Year**: 1993

**Number of pages**: 128

**Type of paper**:*Survey/Study*

**Title:**Feasibility study of the 320 MW block operating with high pressure feedwater heater turned off

**Authors:**- Bogdan, Željko (4210.00000)
- Šerman, Nikola (46501.00000)

**Ordering party**: Hrvatska elektroprivreda HEP

**Institution depot**: FSB-Zagreb

**Year**: 1993

**Number of pages**: 37

**Language**: hrvatski

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