scholarly journals Cost-optimal energy retrofit for Serbian residential buildings connected to district heating systems

2019 ◽  
Vol 23 (Suppl. 5) ◽  
pp. 1707-1717 ◽  
Author(s):  
Mladen Stojiljkovic ◽  
Mirko Stojiljkovic ◽  
Marko Ignjatovic ◽  
Goran Vuckovic
Keyword(s):  
Residential Buildings ◽  
District Heating ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Optimal Solutions ◽  
Heating Systems ◽  
Energy Retrofit ◽  
Global Cost ◽  
District Heating Systems ◽  
Cost Optimality

Buildings are significant energy consumers and provide a notable potential to reduce primary energy consumption and increase energy efficiency. Cost-effectiveness of energy efficiency projects is of crucial importance for their implementation. Cost-optimality of different packages of energy retrofit measures is studied across the EU, but Serbia mostly lacks such information. This paper analyzes cost-optimal solutions for Serbian residential buildings connected to district heating systems, considering three different scenarios related to the economic input parameters. Additionally, it considers the potential for primary energy savings beyond cost-optimality and associated costs. The optimal solutions, that correspond to minimal global cost or minimal primary energy consumption, are determined as the results of the combinatorial optimization problems. These problems are solved using the genetic algorithm and local search. The results are compared against the ones obtained with the sensitivity analysis. The global cost can be reduced by 8-43% in the cases of cost-optimal solutions, simultaneously saving 30-76% of primary energy. The potential to save primary energy is higher - it exceeds 70% in all the analyzed cases, but also requires higher global cost, sometimes larger than in the absence of the retrofit. The paper also emphasizes high dependencies of the results on very uncertain economic inputs.

scholarly journals Utilizing Sewage Wastewater Heat in District Heating Systems in Serbia - Effects on Sustainability

2021 ◽  
Author(s):  
Marija Živković ◽  
Dejan Ivezic
Keyword(s):  
Energy Source ◽  
Wastewater Treatment ◽  
Carbon Dioxide Emission ◽  
District Heating ◽  
Primary Energy ◽  
Energy Sources ◽  
Heating Systems ◽  
Current State ◽  
District Heating Systems ◽  
Treatment Facilities

Abstract 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 as a big advantage of district heating systems. Despite many advantages, sewage wastewater heat is still a mostly unused resource at the global level and a totally unused energy source in Serbia, while data about the potential of this energy source are lacking. This research proposes a methodology for the determination of the technical potential of waste heat from wastewater treatment facilities for use in district heating systems by heat pump application. Data from existing wastewater treatment facilities are used for providing data for replication in cities without wastewater treatment plants but with district heating systems. An estimation of the recoverable heat energy potential of wastewater is used for evaluation of some effects that could be obtained through its full utilization for heat production in the existing district heating systems. Three groups of indicators are selected for analysis focusing on district heating systems' energy performance (primary energy factor, specific heat consumption per degree day and heating area), the security of energy supply (import dependency, Shannon Wiener diversification index, the share of renewables) and environmental impact (carbon dioxide emission coefficient). Values of the selected indicators are determined for the current state of district heating systems and for the possible future state that could be achieved after full utilization of sewage wastewater potential. The proposed methodology is applied to Serbia, as a case study. It has been shown that all analyzed indicators for the projected future would have more preferable values compared to the values that correspond to the current state of the district heating systems. The use of this renewable energy source should provide primary energy savings of 5% per year, reduction of carbon dioxide emission of 6.5% per year, reduction of import dependency of DH systems of 9.8% and improved diversification of energy sources of 21%.

scholarly journals APLICATION OF REGRESSION ANALYSIS IN FEASIBILITY STUDIES OF CONSUMER CONNECTION TO DISTRICT HEATING SYSTEMS

2021 ◽  
Vol XXVIII (4) ◽  
pp. 121-132
Author(s):  
Corina Chelmenciuc ◽  
◽  
Constantin Borosan ◽  
Vadim Lisnic ◽  
◽  
...  
Keyword(s):  
Regression Analysis ◽  
Urban Areas ◽  
District Heating ◽  
Feasibility Studies ◽  
Heating System ◽  
Primary Energy ◽  
Energy Resources ◽  
District Heating System ◽  
Heating Systems ◽  
District Heating Systems

Nowadays, both globally and in Europe, and nationally, there is a tendency to promote district heating systems to the detriment of individual ones to heat dwellings in urban areas. The need to develop the DHSs is indisputable considering the topicality of global warming, the depletion of the primary energy resources and the energy efficiency trend. This article presents the method of applying regression analysis in feasibility studies for the projects of new heat consumers connection to the district heating system (hereinafter – DHS) or previously disconnected consumers reconnection via individual heating points (hereinafter – IHP) when the necessary investments are to be borne by the DHS operator, and the thermal energy is produced in cogeneration. At the same time, it is demonstrated that there is a direct and linear correlation between fuel consumption and electricity and heat produced in cogeneration at CHP plant.

scholarly journals Effects of implementation of co-generation in the district heating system of the Faculty of Mechanical Engineering in Nis

2010 ◽  
Vol 14 (suppl.) ◽  
pp. 41-51 ◽  
Author(s):  
Mladen Stojiljkovic ◽  
Mirko Stojiljkovic ◽  
Bratislav Blagojevic ◽  
Goran Vuckovic ◽  
Marko Ignjatovic
Keyword(s):  
Natural Gas ◽  
Energy Savings ◽  
Boiler House ◽  
District Heating ◽  
Electrical Energy ◽  
Heating System ◽  
Primary Energy ◽  
District Heating System ◽  
Heating Systems ◽  
District Heating Systems

Implementation of co-generation of thermal and electrical energy in district heating systems often results with higher overall energy efficiency of the systems, primary energy savings and environmental benefits. Financial results depend on number of parameters, some of which are very difficult to predict. After introduction of feed-in tariffs for generation of electrical energy in Serbia, better conditions for implementation of co-generation are created, although in district heating systems barriers are still present. In this paper, possibilities and effects of implementation of natural gas fired cogeneration engines are examined and presented for the boiler house that is a part of the district heating system owned and operated by the Faculty of Mechanical Engineering in Nis. At the moment, in this boiler house only thermal energy is produced. The boilers are natural gas fired and often operate in low part load regimes. The plant is working only during the heating season. For estimation of effects of implementation of co-generation, referent values are taken from literature or are based on the results of measurements performed on site. Results are presented in the form of primary energy savings and greenhouse gasses emission reduction potentials. Financial aspects are also considered and triangle of costs is shown.

Energy Consumption and CO2 Emission of Buildings Built with Industrialized Technology: The Case of Debrecen and Future Trends

2014 ◽  
Vol 899 ◽  
pp. 16-23
Author(s):  
Tamás Csoknyai
Keyword(s):  
Energy Consumption ◽  
Residential Buildings ◽  
District Heating ◽  
Energy Performance ◽  
Future Trend ◽  
Building Stock ◽  
Heating Systems ◽  
Heat Demand ◽  
District Heating Systems ◽  
Inefficient Operation

The residential buildings built with prefabricated technology (also called panel buildings) represent a significant part of the building stock, particularly in Eastern Europe. These buildings are typically 30-40 years old and due to their poor energy performance they have been in the focus of energy policy makers over the recent years. These buildings are typically connected to district heating systems and the continuously decreasing heat demand caused by the renovation subsidy programs resulting in risks of inefficient operation and on the long term it questions the viability of the district heating systems. Therefore it is particularly important to have a clear picture on the energy consumption trends about this segment of the building stock. In this paper, the building stock of the city of Debrecen connected to district heating is analysed. The current energy consumption figures of the buildings are analysed. In Debrecen, the share of retrofitted buildings is relatively low (appr. 15%), therefore a future trend analysis was also carried out. The results of this study can be interesting for other cities as well, particularly those with a significant share of “panel buildings”.

Exergoeconomic Analysis of District Heating Systems

2009 ◽  
Author(s):  
Vittorio Verda ◽  
Serena Fausone
Keyword(s):  
Fossil Fuels ◽  
Probabilistic Approach ◽  
District Heating ◽  
Heating System ◽  
Primary Energy ◽  
Combined Cycle ◽  
District Heating System ◽  
Heating Systems ◽  
District Heating Systems ◽  
Selection Of

District heating is a rational way to use fossil fuels for domestic heating (and cooling) in towns, especially if it is joined to a cogenerative production of electricity. The aim of this paper is to propose the use of exergoeconomic procedures for the design and analysis of district heating systems. Network design basically involves the selection of the areas to be connected to the network as well as the selection of some design variables as the pipe diameters, the location of pumps etc. This choice is operated assuming primary energy consumption as the objective function to be minimized. The application of these concepts is operated through a probabilistic approach derived from Simulated Annealing. An application to the Turin district heating system is presented here. The system is composed of a cogenerative combined cycle, some auxiliary boilers and the pipe network. An exergetic cost is associated to each user or potential user. This information is used to evaluate the opportunities for future expansions of the served area as well as the variation in some of the operating parameters.

scholarly journals Energy Efficiency of Water Heating Systems in Single-Family Dwellings in Brazil

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1068 ◽  
Author(s):  
Juliana May Sangoi ◽  
Enedir Ghisi
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Efficient ◽  
Residential Buildings ◽  
Heating System ◽  
Primary Energy ◽  
Solar Heating ◽  
Primary Energy Consumption ◽  
Single Family ◽  
Heating Systems

The objective of this paper was to compare primary energy consumption and energy efficiency during the operation phase of different types and combinations of water heating systems in single-family dwellings. Systems with an electric shower, liquefied petroleum gas heater, and solar heater with electric backup were analysed. The analysis was performed by means of computer simulation using EnergyPlus. Three Brazilian cities with different climates were assessed, i.e., Curitiba, Brasília and Belém. The systems were compared in terms of final energy and primary energy consumption. Results showed that systems with an electric shower, which have a lower water flow rate, led to lower primary energy consumption. The solar heating system combined with an electric shower was the option with the lowest energy consumption, and the solar heating system with a heating element in the storage tank was the option that consumed more energy. The systems were sized according to the requirements of the Brazilian energy efficiency labelling for residential buildings, and the efficiency level was compared to the results of primary energy consumption. The electric shower was found to be the third lowest energy consumer, but it was ranked the least energy efficient by Brazilian labelling, while systems with high energy consumption, such as gas heaters and solar heaters with a heating element in the storage tank, were ranked the most energy efficient. Therefore, a review of the requirements and methodology of the Brazilian energy efficiency labelling for residential buildings is recommended in order to encourage the use of truly efficient systems. Public policies that encourage solar heating systems should establish requirements regarding the configuration and sizing both the solar heating system and the backup system.

scholarly journals A Thermo-Economic and Emissions Analysis of Different Sanitary-Water Heating Units Embedded Within Fourth-Generation District-Heating Systems

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Primož Poredoš ◽  
Boris Vidrih ◽  
Andrej Kitanovski ◽  
Alojz Poredoš
Keyword(s):  
Local Heating ◽  
District Heating ◽  
Primary Energy ◽  
Hot Water ◽  
Fourth Generation ◽  
Heating Unit ◽  
Energy Factor ◽  
Heating Systems ◽  
District Heating Systems ◽  
The Eu

This paper presents the results of a thermo-economic (TE), primary-energy-factor and CO2-equivalent (CO2 (eq)), emissions-sensitivity analysis for the preparation of sanitary hot water (SHW) in fourth-generation district-heating systems. The annual required additional heat for the SHW provided by a local heating unit, based on an air-to-water heat pump (AWHP), a natural-gas boiler (NG boiler), and an electrical resistance heater (ERH), was determined using a trnsys simulation. Additionally, the seasonal performance factor (SPF) of the HP under consideration was determined. The study considered three possible supply temperatures, i.e., 35, 40, and 45 °C. The results show that a local heating unit based on an AWHP is most efficient in terms of the used primary energy (PE) and CO2 (eq) emissions. This unit is also the second best in terms of TE performance. The unit based on a NG boiler is much more appropriate than an ERH unit in terms of both the primary energy factor (PEF) and the CO2 (eq) emission factors for an electricity generation mix (EGM) that has values higher than the average for the EU-28. The heat generated by this NG unit is also cheaper than the heat produced by an ERH based on the average price for electricity in the EU-28.

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