Dejan Ivezić - Academia.edu (original) (raw)

Papers by Dejan Ivezić

Chemical Industry, 2010

Fuels derived from biomass are an alternative solution for the fossil fuel shortage. Usually this... more Fuels derived from biomass are an alternative solution for the fossil fuel shortage. Usually this kind of fuels is called low calorific value fuels, due to the large proportion of inert components in their composition. The most common is carbon dioxide, and its proportion in biogas can be different, from 10 up to 40%, or even more. The presence of inert component in the composition of biogas causes the problems that are related with flame blow off limits. One of the possibilities for efficient combustion of biogas is the combustion in swirling flow including a pilot burner, aimed to expand the borders of stable combustion. This paper presents an analysis of the influence of the carbon dioxide content to the nitrogen oxides emissions. Laboratory biogas was used with different content of CO2 (10, 20, 30 and 40%). Investigation was carried out for different nominal powers, coefficients of excess air and carbon dioxide content. With increasing content of carbon dioxide, emission of nitr...

Thermal Science

The integration of wastewater heat pumps (using purified water) in district heating systems is an... more The integration of wastewater heat pumps (using purified water) in district heating systems is analyzed in this paper. The simulation procedure is proposed to analyze the impacts of stochasticity of purified water temperature and flow to heat pump integration and operation. The analysis includes calculation of the daily and seasonal coefficient of performance, as well as fossil fuel savings and CO2 emission reduction due to wastewater heat pump use. The proposed procedure is implemented for the case study in the city of Sabac (Serbia) and obtained results are discussed and evaluated. The historical data for two heating seasons was used for simulation. It was shown that the wastewater heat pump could provide 27-28% savings in fuel consumption, and 3.6-4.1% GHG emissions reduction, while the seasonal COP could be 4.2 - 4.3. Simulation based approach shows approximately 40% less savings of fuel consumption, compared to the approach based on the average values of heat pump input paramet...

Thermal Science, 2017

There is a range of modern approaches and models in literature for the evaluation and determinati... more There is a range of modern approaches and models in literature for the evaluation and determination of energy security, which are based on different parameters and indicators. For most of them, a common characteristic is emphasizing the availability of energy, as an important dimension for ensuring energy security. In this paper, concise overview of Serbian energy sectors is given and appropriate energy indicators are defined and determined. Selected indicators provide insight into the main components that characterize availability - security of supply, self-sufficiency, diversification of energy sources, level of renewable energy use and technological maturity. Besides calculation of energy indicators, the aim is to investigate and establish the relationships among components of availability of energy in Serbia, and to provide some recommendations for the policy makers to develop efficacious measures for enhancing energy security. Therefore Analytic Hierarchy Process (AHP) methodol...

UKACC International Conference on Control. Control '96, 1996

ABSTRACT

In Comparison to Deliverable 1.1.where policy packages are in the focus analysis, this report pre... more In Comparison to Deliverable 1.1.where policy packages are in the focus analysis, this report present single energy efficiency policy instruments in seven EU and one candidate Member States. For the buildings sector as well for the transport sector most important instruments are described briefly.

This report aims to present the overview of the energy efficiency policy packages for the buildin... more This report aims to present the overview of the energy efficiency policy packages for the buildings (residential and tertiary) and the transport sectors supported by multi-level governance framework in seven EU and one candidate Member State.

This paper discusses challenges of capacity building in sustainable urban energy planning and dev... more This paper discusses challenges of capacity building in sustainable urban energy planning and development in Western Balkan Countries (WBC). It identifies needs in training of municipal staff and addresses obstacles for transferring sustainable energy education from EU universities to universities of WBC. The analysis of the ten training courses developed and piloted in collaboration with academic and non-academic stakeholders in Bosnia and Herzegovina, Montenegro and Serbia shows that while international cooperation has a good potential to improve quality of capacity building and to catalyse university-society collaboration in WBC, significant efforts on national and local (university) levels are needed to fully capitalise on these opportunities. In particular, it is necessary to enhance an interdisciplinary approach to education in sustainable energy, incorporating economic, social and institutional aspects of energy production and consumption together with the technical ones. On ...

Sustainable Cities and Society, 2020

The district heating system (DHS) is one of the key elements of the Belgrade energy system. Overv... more The district heating system (DHS) is one of the key elements of the Belgrade energy system. Overview of the current state and basic characteristics of the DHS are presented in this paper. The focus is on the planned development of DHS and on the analyses of effects of realization of measures and projects defined by strategic documents related to DHS which are adopted by city authorities (Development Strategy of DHS and Strategy of Belgrade Development). Two exploratory scenarios were developed by using the LEAP tool. Heat consumption, fuel mix, and CO 2 emission are presented for both scenarios. Different measures on the demand side and infrastructural development in these two scenarios are analyzed using indicators related to the security of supply (primary energy factor, import dependency) and to climate change (CO 2 emissions). The results show that the aim of current strategic documents was to provide security of supply (mostly by the introduction of heat from the thermal powerplant and to less extent by the introduction of RES and improvement of efficiency), while the climate issues were mostly neglected. The positive effect of the introduction of RES to CO 2 emission was nullified by the indirect introduction of lignite in the energy mix.

Energy Sources, Part B: Economics, Planning, and Policy, 2016

The strategy of long-term energy development of Serbia identifies an increase of share of natural... more The strategy of long-term energy development of Serbia identifies an increase of share of natural gas in final energy consumption as one of the main aims. Serbia has signed a strategic agreement with the Russian Federation on cooperation in the oil and gas sector, within which the project South Stream pipeline is planned to be realized. In addition, the Republic of Serbia has signed the Treaty that establishes the Energy Community and accepted the obligation to implement the Energy Community acquis. In the natural gas sector it is related to establishing a fully liberated national and regional natural gas market. Overview and analysis of the current state concerning indigenous production, infrastructure, and consumption structure are presented as the basis for projections of the possible Serbian natural gas sector development. Three possible scenarios for future natural gas consumption, considering different influential parameters, have been developed by the Long-range Energy Alternatives Planning System (LEAP) software. Scenarios characterized by different levels and structures of consumption are analyzed in detail.

Tehnika, 2011

The one of the methods that successfully solves the problem of paraffin deposition in the well du... more The one of the methods that successfully solves the problem of paraffin deposition in the well during paraffin-base crude production is an application of electric heating cable. The heating cable application method removes or prevents the paraffin deposition. The ...

Renewable and Sustainable Energy Reviews

Energija, ekonomija, ekologija

This paper presents the results of a household survey about individual heating conducted in Serbi... more This paper presents the results of a household survey about individual heating conducted in Serbia in 2020. The objective of the survey was to examine the details of individual heating systems in households and households’ attitudes regarding the energy transition. The results indicate the obsolescence of the heating system, low efficiency, insufficient investment in the implementation of energy efficiency measures, and lack of funds for investment in sustainable heating. The main priorities when choosing a mode of heating are heating system costs and fuel costs, while the impacts of environmental factors and energy transition awareness are relatively weak. The cost of heating systems has also been identified as the biggest barrier to replacing existing systems. On the other hand, about half of households have a positive attitude towards potentially subsidizing the replacement of current heating systems with new and more efficient ones.

The user has requested enhancement of the downloaded file.

Strojniski Vestnik-journal of Mechanical Engineering, 2010

Robust controllers based on Internal Model Control (IMC) theory are developed in this paper to im... more Robust controllers based on Internal Model Control (IMC) theory are developed in this paper to improve the robust performance of industrial boiler system against uncertainties and disturbances. A simplified model of a boiler’s drum unit is developed and transfer matrix realization of its dynamics is obtained for a nominal operational condition. Controllers parameters are selected in accordance with the frequency domain optimization method based on micro-optimality frameworks. The proposed controllers are robust for reference signals and/or for disturbances. Finally, a comparison between the performances of the closed-loop system with designed IMC controllers is obtained.

Energy and Buildings

Abstract This paper presents the results of the household survey on individual household heating ... more Abstract This paper presents the results of the household survey on individual household heating systems in Serbia. The survey was conducted in the period October to December 2020 with the participation of 1,100 households with individual household heating systems. The information collected in the questionnaire can be separated into three main parts: basic household data, current heating system characteristics, and households’ perceptions and attitudes. The survey results provide unique and comprehensive information concerning individual household heating systems and the main barriers and drivers for a successful energy transition in the future. The results show the obsolescence of household heating systems, low efficiency, insufficient investment in thermal insulation in the past, and lack of financial resources for investing in sustainable heating. On the other hand, this survey highlights the positive attitude of about half of households towards potential subsidizing of the cost of new heating systems. This survey presents a valid starting point for defining instruments aimed to improve energy efficiency in the household sector, diminish its influence on climate change, and secure energy transition towards sustainable heating systems. The obtained results should be indicative for middle-income developing countries at the beginning of the energy transition process.

Effectiveness evaluation is one of basic components in engineering asset management. It is overal... more Effectiveness evaluation is one of basic components in engineering asset management. It is overall concept and represents measurement of quality of service level for selected engineering system. Effectiveness contains series of partial indicators related to time in operation and time for maintenance activities, as well as to functional properties of the system. This article describes analysis and structuring of partial indicators, as well as development of model for their synthesis to the level of effectiveness. Indicators have hybrid character (measured values and experts judgments), and the fuzzy inference model is suggested for their processing and integration into the effectiveness. This approach provided possibility for evaluation of a technical system in sense of decision making about remaining capabilities and optimization of life cycle costs. To demonstrate the opportunities of developed model for effectiveness evaluation, case study related to bulldozers is presented. Bulld...