Vladimir Glazar | Technical University in Rijeka (original) (raw)
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Papers by Vladimir Glazar
Sustainability
This article presents the performance analysis of a 700 MW future planned advanced ultra-supercri... more This article presents the performance analysis of a 700 MW future planned advanced ultra-supercritical (A-USC) coal-fired power plant fitted with post-combustion carbon capture and storage (CCS) technology. The reference A-USC unit without CCS achieves a net efficiency of 47.6% with CO2 emissions of 700 kgCO2/MWh. Relatively to subcritical units, the net efficiency of the A-USC is 8%-pts higher while CO2 emissions are 16.5% lower. For a CO2 removal rate of 90%, the net efficiency of the CCS integrated A-USC unit is 36.8%. The resulting net efficiency loss is 10.8%-pts and the electricity output penalty is 362.3 kWhel/tCO2 for present state CCS technology. The study continues with the assessment of interface quantities between the capture unit and the steam cycle affecting the performance of the A-USC. Improved CO2 absorbents could alleviate the net efficiency loss by 2–3%-pts, and enhanced CO2 compression strategies and advanced heat integration could further reduce the efficiency l...
Engineering Review, Jul 23, 2010
E3S Web of Conferences, 2019
International Journal of Refrigeration, 2015
Experimental and numerical analysis of heat transfer and fluid flow in the compact heat exchanger... more Experimental and numerical analysis of heat transfer and fluid flow in the compact heat exchanger has been done in this paper. In an open circuit wind tunnel, developed on purpose for this investigation, the measurement of working media temperatures and mass flow rates for heat exchanger with microchannel coil has been accomplished. In accordance with the heat exchangers used for experiments, numerical 3D simulation of adequate geometry shapes has been done. With utilization of air/water side numerical simulation, more detailed results have been achieved in relation to the simulation that assumes constant temperature or constant heat flux on the pipe wall. Good agreement between experimentally measured and numerically calculated results has been accomplished. The influence of different microchannel shapes on heat transfer effectiveness and pressure drop has been studied numerically. Comparison of results has been made accompanied by the discussion and final conclusions.
Journal of Energy Storage, 2020
In this paper a number of numerical simulations were performed to determine the geometry and the ... more In this paper a number of numerical simulations were performed to determine the geometry and the process parameters influence on the large volumetric heat storage tank radial plate diffuser pressure drop. The tank is used in district heating systems. To reduce the possibility of a pressure drop in the diffuser below the water saturation pressure, three basic diffuser types were tested sharpe edge joint (SEJ), conical element (COE) and curved element (CUE). The analysis shows the differences and similarities between the diffuser types and their influence on the static and total diffuser pressure drop. The geometric similarity of the hermetic compressor radial valve with heat storage tank radial plate diffuser was used to validate the numerical model. The numerical calculation results were compared with the experimental measurements of the air pressure drop on the radial valves front plate taken from the literature. Good correlation between the calculation results and experimental measurements has been achieved. Along with mentioned, the diffuser model similarity effect is also presented and analyzed. The obtained results showed that, the static pressure drop remains the same for different diffuser sizes, when the geometric similarity of the diffuser is preserved.
Journal of Energy Storage, 2020
In this paper a number of numerical simulations were performed to determine the geometry and the ... more In this paper a number of numerical simulations were performed to determine the geometry and the process parameters influence on the large volumetric heat storage tank radial plate diffuser pressure drop. The tank is used in district heating systems. To reduce the possibility of a pressure drop in the diffuser below the water saturation pressure, three basic diffuser types were tested sharpe edge joint (SEJ), conical element (COE) and curved element (CUE). The analysis shows the differences and similarities between the diffuser types and their influence on the static and total diffuser pressure drop. The geometric similarity of the hermetic compressor radial valve with heat storage tank radial plate diffuser was used to validate the numerical model. The numerical calculation results were compared with the experimental measurements of the air pressure drop on the radial valves front plate taken from the literature. Good correlation between the calculation results and experimental measurements has been achieved. Along with mentioned, the diffuser model similarity effect is also presented and analyzed. The obtained results showed that, the static pressure drop remains the same for different diffuser sizes, when the geometric similarity of the diffuser is preserved.
Energy, 2020
This paper presents various numerical analyses of two-dimensional temperature and velocity fields... more This paper presents various numerical analyses of two-dimensional temperature and velocity fields in vertical cylindrical large volumetric heat storage tanks used in municipal heating applications. Numerical simulations were performed in order to investigate the shape impact of the heat storage tank (height-to-diameter ratio), the diffuser distance from the top of the tank, temperature difference between the warm and cold water and the volume flow variation on temperature stratification in the tank. The accuracy and precision of the numerical model was verified by comparing the numerical calculation results with the measurement results from the literature. An empirical model for the calculation of the tank wall (mantle) insulation thickness with maximum constant temperature inside the tank was also developed. The effect of reducing the insulation thickness and changing the seasons on quality of the temperature stratification and thermal losses through the tank insulation were analyzed. The financial analysis justified the possible reduction of the insulation thickness, and more flexible investment in the plant is presented.
International Journal of Heat and Mass Transfer, 2020
Multivariate optimization of the air-water heat exchanger with microchannel coil has been present... more Multivariate optimization of the air-water heat exchanger with microchannel coil has been presented in this paper. The effects of four geometry parameters, i.e. fin pitch, microchannel flat tube transversal row pitch, number of small channels and partition wall thickness, on heat transfer rate per volume and mass, pressure drops on air and water side, heat transfer efficiency and rate of compactness have been examined using the Response Surface Methodology. Data set, composed of 27 different geometry models, has been prescribed using Box-Behnken design method. Experimentally validated, 3D mathematical model and numerical procedure have been used for numerical simulations. Fluid flow and heat transfer simulations have been performed using CFD solver FLUENT. Numerical results have been employed to calculate the objective function responses. Obtained contour plots of the objective functions have been shown for various setups. According to objective function results, nonlinear regression models (polynomial functions) have been derived and the Genetic Algorithm has been used to obtain optimal setup. The comparison of results has been given, followed by discussion and conclusions.
Spatial ability has been confirmed to be of particular importance for successful engineering grap... more Spatial ability has been confirmed to be of particular importance for successful engineering graphics education and to be a component of human intelligence that can be improved through instruction and training. Consequently, the creation and communication by means of graphics demand careful development of spatial skills provided by the balanced curricula based on the research results in multi disciplinary area. The approach to engineering graphics education had been transformed to meet spatial skills improvement even before significant and fast changes arose from the development of computer technology enabling the engineer powerful tools and techniques. The correlation and interference between new technologies widely introduced in engineering graphics education and spatial ability/skills, have initiated new studies to establish the basis of holistic engineering graphics education. This paper presents the overview of some efforts and possible answers resulting from intensive research into spatial ability and skills and their implementation in the conception of graphics education in engineering environment.
Experimental and numerical analysis of heat transfer and fluid flow in the compact heat exchanger... more Experimental and numerical analysis of heat transfer and fluid flow in the compact heat exchanger has been done in this paper. In an open circuit wind tunnel, developed on purpose for this investigation, the measurement of working media temperatures and mass flow rates for heat exchanger with microchannel coil has been accomplished. In accordance
with the heat exchangers used for experiments, numerical 3D simulation of adequate geometry shapes has been done. With utilization of air/water side numerical simulation, more detailed results have been achieved in relation to the simulation that
assumes constant temperature or constant heat flux on the pipe wall. Good agreement between experimentally measured and numerically calculated results has been accomplished.
The influence of different microchannel shapes on heat transfer effectiveness and pressure drop has been studied numerically. Comparison of results has been made accompanied by the discussion and final conclusions.
This article presents a review of glyph-based techniques for engineering visualization as well as... more This article presents a review of glyph-based techniques for engineering visualization as well as practical application for the multivariate visualization process. Two glyph techniques, Chernoff faces and star glyphs, uncommonly used in engineering practice, are described, applied to the selected data set, run through the chosen optimization methods and user evaluated. As an example of how these techniques
function, a set of data for the optimization of a heat exchanger with a microchannel coil is adopted for visualization. The results acquired by the chosen visualization techniques are related to the results of optimization carried out by the response surface method and compared with the results of user evaluation.
Based on the data set from engineering research and practice, the advantages and disadvantages of these techniques for engineering visualization are identified and discussed.
The development of three-dimensional Computer Aided Design (3D CAD) technology has additionally s... more The development of three-dimensional Computer Aided Design (3D CAD) technology has additionally spurred research into spatial ability to find the ways for its enhancement through teaching and instruction and to understand the mechanism
of its assessment. The techniques involved in multimedia engineering environment of today as well as their inclusion into engineering curricula and courses have to be strongly supported by wider knowledge of spatial ability. This paper is a review of research results applied to engineering graphics education by respecting spatial ability as a recognized predictor of success in engineering. The development of engineering
graphics teaching based on research suggestions about spatial ability represents an increasingly complex approach that puts additional stress on engineering graphics educators. Thus classical tests for the assessment of spatial ability are
described, the applied strategies for their solving are presented, the selected obtained results are compared, and a distinction is drawn between the strategies employed for more complex spatial tasks that engineering is dealing with.
Heat Transfer Engineering, 2012
Sustainability
This article presents the performance analysis of a 700 MW future planned advanced ultra-supercri... more This article presents the performance analysis of a 700 MW future planned advanced ultra-supercritical (A-USC) coal-fired power plant fitted with post-combustion carbon capture and storage (CCS) technology. The reference A-USC unit without CCS achieves a net efficiency of 47.6% with CO2 emissions of 700 kgCO2/MWh. Relatively to subcritical units, the net efficiency of the A-USC is 8%-pts higher while CO2 emissions are 16.5% lower. For a CO2 removal rate of 90%, the net efficiency of the CCS integrated A-USC unit is 36.8%. The resulting net efficiency loss is 10.8%-pts and the electricity output penalty is 362.3 kWhel/tCO2 for present state CCS technology. The study continues with the assessment of interface quantities between the capture unit and the steam cycle affecting the performance of the A-USC. Improved CO2 absorbents could alleviate the net efficiency loss by 2–3%-pts, and enhanced CO2 compression strategies and advanced heat integration could further reduce the efficiency l...
Engineering Review, Jul 23, 2010
E3S Web of Conferences, 2019
International Journal of Refrigeration, 2015
Experimental and numerical analysis of heat transfer and fluid flow in the compact heat exchanger... more Experimental and numerical analysis of heat transfer and fluid flow in the compact heat exchanger has been done in this paper. In an open circuit wind tunnel, developed on purpose for this investigation, the measurement of working media temperatures and mass flow rates for heat exchanger with microchannel coil has been accomplished. In accordance with the heat exchangers used for experiments, numerical 3D simulation of adequate geometry shapes has been done. With utilization of air/water side numerical simulation, more detailed results have been achieved in relation to the simulation that assumes constant temperature or constant heat flux on the pipe wall. Good agreement between experimentally measured and numerically calculated results has been accomplished. The influence of different microchannel shapes on heat transfer effectiveness and pressure drop has been studied numerically. Comparison of results has been made accompanied by the discussion and final conclusions.
Journal of Energy Storage, 2020
In this paper a number of numerical simulations were performed to determine the geometry and the ... more In this paper a number of numerical simulations were performed to determine the geometry and the process parameters influence on the large volumetric heat storage tank radial plate diffuser pressure drop. The tank is used in district heating systems. To reduce the possibility of a pressure drop in the diffuser below the water saturation pressure, three basic diffuser types were tested sharpe edge joint (SEJ), conical element (COE) and curved element (CUE). The analysis shows the differences and similarities between the diffuser types and their influence on the static and total diffuser pressure drop. The geometric similarity of the hermetic compressor radial valve with heat storage tank radial plate diffuser was used to validate the numerical model. The numerical calculation results were compared with the experimental measurements of the air pressure drop on the radial valves front plate taken from the literature. Good correlation between the calculation results and experimental measurements has been achieved. Along with mentioned, the diffuser model similarity effect is also presented and analyzed. The obtained results showed that, the static pressure drop remains the same for different diffuser sizes, when the geometric similarity of the diffuser is preserved.
Journal of Energy Storage, 2020
In this paper a number of numerical simulations were performed to determine the geometry and the ... more In this paper a number of numerical simulations were performed to determine the geometry and the process parameters influence on the large volumetric heat storage tank radial plate diffuser pressure drop. The tank is used in district heating systems. To reduce the possibility of a pressure drop in the diffuser below the water saturation pressure, three basic diffuser types were tested sharpe edge joint (SEJ), conical element (COE) and curved element (CUE). The analysis shows the differences and similarities between the diffuser types and their influence on the static and total diffuser pressure drop. The geometric similarity of the hermetic compressor radial valve with heat storage tank radial plate diffuser was used to validate the numerical model. The numerical calculation results were compared with the experimental measurements of the air pressure drop on the radial valves front plate taken from the literature. Good correlation between the calculation results and experimental measurements has been achieved. Along with mentioned, the diffuser model similarity effect is also presented and analyzed. The obtained results showed that, the static pressure drop remains the same for different diffuser sizes, when the geometric similarity of the diffuser is preserved.
Energy, 2020
This paper presents various numerical analyses of two-dimensional temperature and velocity fields... more This paper presents various numerical analyses of two-dimensional temperature and velocity fields in vertical cylindrical large volumetric heat storage tanks used in municipal heating applications. Numerical simulations were performed in order to investigate the shape impact of the heat storage tank (height-to-diameter ratio), the diffuser distance from the top of the tank, temperature difference between the warm and cold water and the volume flow variation on temperature stratification in the tank. The accuracy and precision of the numerical model was verified by comparing the numerical calculation results with the measurement results from the literature. An empirical model for the calculation of the tank wall (mantle) insulation thickness with maximum constant temperature inside the tank was also developed. The effect of reducing the insulation thickness and changing the seasons on quality of the temperature stratification and thermal losses through the tank insulation were analyzed. The financial analysis justified the possible reduction of the insulation thickness, and more flexible investment in the plant is presented.
International Journal of Heat and Mass Transfer, 2020
Multivariate optimization of the air-water heat exchanger with microchannel coil has been present... more Multivariate optimization of the air-water heat exchanger with microchannel coil has been presented in this paper. The effects of four geometry parameters, i.e. fin pitch, microchannel flat tube transversal row pitch, number of small channels and partition wall thickness, on heat transfer rate per volume and mass, pressure drops on air and water side, heat transfer efficiency and rate of compactness have been examined using the Response Surface Methodology. Data set, composed of 27 different geometry models, has been prescribed using Box-Behnken design method. Experimentally validated, 3D mathematical model and numerical procedure have been used for numerical simulations. Fluid flow and heat transfer simulations have been performed using CFD solver FLUENT. Numerical results have been employed to calculate the objective function responses. Obtained contour plots of the objective functions have been shown for various setups. According to objective function results, nonlinear regression models (polynomial functions) have been derived and the Genetic Algorithm has been used to obtain optimal setup. The comparison of results has been given, followed by discussion and conclusions.
Spatial ability has been confirmed to be of particular importance for successful engineering grap... more Spatial ability has been confirmed to be of particular importance for successful engineering graphics education and to be a component of human intelligence that can be improved through instruction and training. Consequently, the creation and communication by means of graphics demand careful development of spatial skills provided by the balanced curricula based on the research results in multi disciplinary area. The approach to engineering graphics education had been transformed to meet spatial skills improvement even before significant and fast changes arose from the development of computer technology enabling the engineer powerful tools and techniques. The correlation and interference between new technologies widely introduced in engineering graphics education and spatial ability/skills, have initiated new studies to establish the basis of holistic engineering graphics education. This paper presents the overview of some efforts and possible answers resulting from intensive research into spatial ability and skills and their implementation in the conception of graphics education in engineering environment.
Experimental and numerical analysis of heat transfer and fluid flow in the compact heat exchanger... more Experimental and numerical analysis of heat transfer and fluid flow in the compact heat exchanger has been done in this paper. In an open circuit wind tunnel, developed on purpose for this investigation, the measurement of working media temperatures and mass flow rates for heat exchanger with microchannel coil has been accomplished. In accordance
with the heat exchangers used for experiments, numerical 3D simulation of adequate geometry shapes has been done. With utilization of air/water side numerical simulation, more detailed results have been achieved in relation to the simulation that
assumes constant temperature or constant heat flux on the pipe wall. Good agreement between experimentally measured and numerically calculated results has been accomplished.
The influence of different microchannel shapes on heat transfer effectiveness and pressure drop has been studied numerically. Comparison of results has been made accompanied by the discussion and final conclusions.
This article presents a review of glyph-based techniques for engineering visualization as well as... more This article presents a review of glyph-based techniques for engineering visualization as well as practical application for the multivariate visualization process. Two glyph techniques, Chernoff faces and star glyphs, uncommonly used in engineering practice, are described, applied to the selected data set, run through the chosen optimization methods and user evaluated. As an example of how these techniques
function, a set of data for the optimization of a heat exchanger with a microchannel coil is adopted for visualization. The results acquired by the chosen visualization techniques are related to the results of optimization carried out by the response surface method and compared with the results of user evaluation.
Based on the data set from engineering research and practice, the advantages and disadvantages of these techniques for engineering visualization are identified and discussed.
The development of three-dimensional Computer Aided Design (3D CAD) technology has additionally s... more The development of three-dimensional Computer Aided Design (3D CAD) technology has additionally spurred research into spatial ability to find the ways for its enhancement through teaching and instruction and to understand the mechanism
of its assessment. The techniques involved in multimedia engineering environment of today as well as their inclusion into engineering curricula and courses have to be strongly supported by wider knowledge of spatial ability. This paper is a review of research results applied to engineering graphics education by respecting spatial ability as a recognized predictor of success in engineering. The development of engineering
graphics teaching based on research suggestions about spatial ability represents an increasingly complex approach that puts additional stress on engineering graphics educators. Thus classical tests for the assessment of spatial ability are
described, the applied strategies for their solving are presented, the selected obtained results are compared, and a distinction is drawn between the strategies employed for more complex spatial tasks that engineering is dealing with.
Heat Transfer Engineering, 2012