Dejan Ivezić

University of Belgrade · Centre for Energy of the Faculty of Mining and Geology

Due to its complexity and heterogeneity, the household sector represents an essential point in energy transition policies. In the European Union, household energy consumption accounts for about 26% of final energy consumption, while in Serbia, this sector has the largest share in final consumption, accounting for about one-third of final consumptio...

The success of energy transition planning depends on several influential and variable factors that need to be considered and tracked in modeling to support policymakers. Expert-based energy models are mainly developed following the assumptions of experts and, in most cases, a limited number of stakeholders. This top-down modeling approach will prov...

Final energy consumption in the industrial sector accounts for almost 25% of energy-related final energy consumption in the Republic of Serbia. It is estimated that 50-70% of energy consumption in industry, is intended to heat production in various industrial processes. Some of the produced heat is irreversibly wasted: through walls of process equi...

To explore pathways of the energy transition of household heating, an agent-based simulation model was developed for the case of the Serbian household sector. The model is focused on individual entities (households) with the objective to explore the effects of policy instruments on energy transition in households with individual heating systems. Em...

Transformation of the heating sector is recognized as being essential for ensuring reliable and affordable energy services provided with reduced consumption of energy sources and diminished impact on the environment and less import dependency. The possibility of utilizing energy sources that otherwise would be wasted needs to be considered and trea...

U radu su prikazani rezultati istraživanja i ankete koja je sprovedena 2020. godine u domaćinstvima sa individualnim sistemima grejanja u Srbiji. Cilj ankete je bio da se sagleda stanje individualnih sistema grejanja, ali i stavovi vlasnika sistema vezano za energetsku tranziciju. Rezultati ukazuju na zastarelost sistema grejanja, nisku efikasnost,...

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...

When assessing the potential of renewable energy alternatives for electricity generation, it is necessary to implement a multi-perspective approach that includes economic, technical, environmental, and socio-political criteria. For the evaluation of criteria and alternatives, the Fuzzy Analytical Hierarchy Process (FAHP) method is applied. The obta...

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...

Transformation of the heating sector is recognized as being essential for ensuring reliable and affordable energy services provided with reduced consumption of energy sources, diminished impact on the environment and less import dependency. The possibility of utilizing energy sources that otherwise would be wasted needs to be considered and treated...

To strengthen the security of supply of the Serbian gas sector, it is necessary to analyze the impact of planned strategic measures. The analysis involves the identification of the most influential threats to the security of natural gas supply and prioritization of the strategic measures for overcoming the consequences of threats. The proposed meth...

In the next period, it is planned to build several wastewater treatment systems in major cities in Serbia. Experiences from the facilities currently in operation show that treated wastewater (taking into consideration available flow and temperature) could be a significant source of renewable energy. The paper presents examples of good practice in t...

The use of solid fuels (wood biomass and coal) for heating of households continues to be common practice within European countries. Solid fuel combustion in households contributes more than 46% to total emissions of fine particulate matter. In this study, a life-cycle assessment (LCA) of firewood-based and pellet-based heating systems is performed....

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 DH...

Natural gas is used for the production of almost 20% of total energy today. The natural gas security of the Republic of Serbia is an urgent strategic, political and security issue. Serbia is one of the most vulnerable countries in Southeast Europe, because it only has one supply route. This study is a contribution to efforts to better understand th...

The main idea of this chapter is to promote maintenance centered to safety, in accordance to adaptive fuzzy inference model, which has online adjustment to working conditions. Input data for this model are quality of service indicators of analyzed engineering system: reliability, maintainability, failure consequence, and severity and detectability....

Devices, based on the condensation technology are conquering the markets around the world as well as in our country. The most contemporary technology, ecologic aspect, cost-effectivness as well as a wide spectrum of devices with various concepts and strenghts are the main reason for this rising trend.

Ensuring security of supply for the domestic natural gas market is one of the priorities of Serbian energy sector development. In the natural gas sector, the Republic of Serbia is strongly dependent on Russian gas. Import dependency is almost 80% and gas is imported via a single supply route. In order to evaluate the security of the natural gas sup...

Bioenergetsko selo Kostojevići

Natural gas is considered as the most environmentally acceptable fossil fuel, thus it is an alternative to petroleum derivates, dominantly used in internal combustion engines. Physical properties of a fuel, as well as a behavior during combustion process are affected by its composition. This paper presets analysis of effect of natural gas compositi...

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...

Knowledge is of primary importance for sustainabilising energy systems. It is not just the knowledge to develop new generic technological systems, but especially the knowledge to pick the right energy systems for the local conditions, and to use these conditions optimally to sustainabilise the pre-existing energy systems. Both the geophysical condi...

Biomass is individually the most significant renewable resource potential in Serbia, but this energy source is still far from being sufficiently and adequately utilized. Biomass energy utilization generally depends on a large number of factors, as its availability, cost-effectiveness, level of biomass market development, economic incentives, infras...

Sustainability transformation of the heating sector is recognised as being essential for reaching climate and environmental targets while improving the quality of life in cities worldwide. Participatory strategic planning enabled by scenario methods can be an important tool to guide this transformation, but methods for qualitative scenario analysis...

Multivariable controller design for grinding circuit is the subject of this work. Model of grinding circuit in Majdanpek Copper Mine is subjected to the newly proposed sequential design method, based on the Gauss-Jordan factorization and Nyquist-like techniques. Due to the nature of the applied design method, generalization to any other grinding ci...

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 o...

The expected growth of living standard, number of inhabitants and development of technology, industry and agriculture will cause a significant increase of energy consumption in cities. Three scenarios of energy sector development until 2030 and corresponding energy consumption for the city of Belgrade are analyzed in this paper. These scenarios con...

Leaving produced gas entrained in heavy oil pipelines reduces energy costs by allowing the oil to flow at a lower temperature. This method achieved energy savings for two well pipelines in Serbia's Turija North oil field of 5.4 and 9.5%. This field produces heavy oil from 60 wells and has four gathering stations. Each well is connected to a gatheri...

Serbia is heavily dependent on expensive imported energy resources (oil, gas, and high-quality coal) that place a big burden on the economy. Pollution, related to energy production and consumption, is becoming a great environmental concern in the country. At the same time, it is estimated that Serbia has the potential to produce almost 4 Mtoes per...

This article presents the model for calculating the performance of dependability for complex technical systems. According to ISO-IEC 300, dependability is an overall indicator for the quality of service and considers simultaneously reliability, maintainability, and maintenance support. For a proper understanding of the quality of service for any te...

This article aims to present a new approach for assessing of maintenance support and model for its introduction into dependability concept. Process of expertise judgment is used directly for assessing the organization of maintenance support and it is shown in the form of linguistic variables as appropriate fuzzy sets. For the introduction of mainte...

Lignite, as an energy resource, is a mainstay of electricity generation in the Republic of Serbia. Installed capacity of lignite power plants represents 68% of the total installed capacity of Electric Power Industry of Serbia, the only company in Serbia, which manages electricity generation. In the future, with the increase in demand for electricit...

This study presents a model for dependability performance analysis of bucket wheel excavators using fuzzy sets. Dependability is overall indicator for quality of service, and considers simultaneously reliability, maintainability and maintenance support. As bucket wheel excavator is a technical system with a complex hierarchical structure, synthesis...

Considering the planned economic development of Serbia, its geostrategic position, structure and energy reserves availability and existing energetic infrastructure, the activities at a gas energy sector are top priorities of Serbian Energy Development Strategy. These activities include development of strategic-regional infrastructure for gas transp...

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. Con...

Fuels derived from biomass are an alternative solution for the fossil fuel shortage. Usually fuels of this kind are 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...

An evaluation model for bucket wheel excavator depend-ability is analysed in this paper. The model is formed to introduce fuzzy sets theory in dependability analysis regards to performances of reliability, maintainability and maintenance support, as well for synthesis of dependability from the lowest to higher level of excavators' structure. Depend...

Economic evaluation of different energy supply systems (district or local heating by natural gas) in Serbia is considered in this paper. According to variety of Serbian settlements (in density, size and layout of buildings) model which has ability to represent their different characteristics is formed. Model is based on identification of smaller ur...

Increasing of natural gas share in fulfillment of energy requirements is strategic direction of Serbian energy sector for a long time. This fact, together with environmental friendly use of natural gas, enforces accelerated development of natural gas supply system in the region of Eastern Serbia. In this paper, energy balances of Eastern Serbia mun...

This paper presents a model for dependability performance evaluation by fuzzy sets utilization. Basic dependability indicators (reliability, maintainability and maintenance support) are used for the analysis of technical systems' conditions from the aspects of design, construction, maintenance and logistics. These indicators as well as associated d...

Implementation of dependability performance was described in detail by standard ISO-IEC 300. In this paper possibility of dependability synthesis and analysis based to fuzzy sets theory is presented. Such conceptual and mathematic approach is appropriate for investigation and absorption of information related to machines' quality of service. Qualit...

An experimental research and analysis of performance of three domestic house hold gas appliances was carried out. The objective of this work, based on the conducted analysis of the research data, was to improve the appliances? performance, prefer ably through relative simple modifications, in order to satisfy DIN 4702 emissions and efficiency stand...

Possibility of geothermal energy utilization for balneology and recreation purposes is presented in this paper. For single geothermal borehole VS-2/H in Veliko Selo, low temperature heating and sanitary hot water preparation system for spa center is designed. Techno-economic analysis of proposed solution was done.

Performance analysis of technical systems by fuzzy sets utilization and synthesis of obtained information by evidential reasoning, give opportunity for deep understanding of considered technical system behavior. Basic condition, which is almost always satisfied, is possibility of system separation to different hierarchical levels. Another condition...

The aim of this paper is to present an application of robust inverse Nyquist array control design method to a milling circuit in Majdanpek Copper Mine. An existent model of a milling circuit was adopted to respond to robust inverse Nyquist array methodology demand by introducing model uncertainty, and optimal robust controller of milling circuit is...

In this paper, an optimal robust control approach for an important subsystem of the boiler is presented. Various types of controller using frequency domain optimization method based on μ-optimality framework are designed. Different structures of low-order controllers, a decentralized controller and a new controller based on Internal Model Control (...

This article presents a useful analysis and synthesis technique for the design of multivariable feedback systems. Optimal robust decentralized controllers of nominal and diagonal dominant nominal model of an important subsystem of the boiler using the structured singular value approach are designed. The controllers proposed are robust for reference...

The assignments of all closed-loop system poles by means of constant output feedback, has been considered. Through the use of Kronecker product, closed-loop matrix equation is expressed as set of linear sets of equations explicit in the elements of control matrix. Obtained set of equations is partitioned into two subsets, the first of which yields...