Suchergebnisse

The district heating system in Serbia, with an installed capacity of 6,600 MW, currently supplies 58 towns with thermal energy. As a candidate country for accession to the European Union, Serbia faces the obligation to reduce the level of its greenhouse gas emissions as part of environmental reforms. This paper presents a basic scenario and three alternatives for final energy consumption in the district heating sector for the years 2015, 2020 and 2025. It is suggested that demand for heating will increase 10% up to 2020 and by 15% up to2025, in relation to 2015 levels, while the share of each energy carrier will not change. Changing the structure of energy sources for heat supply assumes a decrease in the share of coal and liquid fuel, and increases in the use of biomass and natural gas. The results obtained were compared to the General Index of Sustainability which is a measure of the complexity of the proposed energy scenario. The paper considers the formation of related energy indicators as quantitative tools for the analysis of changes. It also proposes a methodology for multi-criteria analysis in the sustainability assessment of complex energy systems based on the stochastic evaluation of criteria (sets of indicators and sub-indicators). In this way, the results of the multi-criteria assessment can help in the decision-making process in cases where economic, social and ecological criteria are considered to be influential. © 2018 Serbian Society of Heat Transfer Engineers.

New Regulations on energy efficiency in buildings in the Republic of Serbia legislate values for the temperature correction factor used to calculate the heat flux to the outdoor environment through construction elements of a certain type. The temperature correction factor is used to correct errors caused by calculation of heat losses based on the design outdoor and indoor temperature difference of building elements adjacent to unheated spaces which are in direct contact with the ground or external environment. Since the temperature correction factor directly influences the calculation of total heat losses and total annual energy demand, it is recommended that the temperature correction factor be determined on the basis of measured values of outdoor and indoor air temperature, or, on the basis of the values obtained by the simulation. This paper presents the results of measurements in the High School of Design, Textile and Management in Belgrade in order to assess energy efficiency and the energy performance of buildings. Data obtained on the basis of measurements, such as indoor and outdoor temperatures, are used for the calculation of the heat transfer coefficient for the building envelope elements as well as to calculate a temperature correction factor for the unheated attic space of the building. This paper also offers a dynamic simulation of the multi-zones building in the TRNSYS environment. The aim was to compare temperature correction factor values obtained from measured temperature values, with those calculated from standard, taken from the Regulation table and produced by simulation. © 2018 Serbian Society of Heat Transfer Engineers.