scholarly journals Techno-economic and environmental optimization of heat supply systems in urban areas

2018 ◽  
Vol 22 (Suppl. 5) ◽  
pp. 1635-1647
Author(s):  
Igor Shesho ◽  
Risto Filkoski ◽  
Done Tashevski

The present work deals with an optimization model for selection of optimal heating structure in urban areas also considering the environmental aspects. The optimization model was established in order to facilitate the decision making during selection phase of heat sources locations and defining the boundaries of their action at the pre-design phase of heat supply schemes development of settlements. Within the model is performed comparative analysis between ten heating systems, whereas as leading criteria in the comparison procedure are considered heat load density per unit of area, techno-economic aspects, and environmental impact. The optimization result actually defines the optimal heating system type in regard of the heat load density per unit area. The model provides possibility in defining standard values of heat density indicators, according to which can be assessed the economic feasibility of implementing district heating system for the selected urban area. The less value of heat density in the system, the higher specific costs for generation, distribution, and transmission of heat energy. Further-more, the model is applied and verified for the local urban, infrastructural, technical and environmental conditions of the city of Skopje. The process of determination of optimal heating structure has holistic approach, where, beside techno-economic aspects and feasibility, the environmental aspect of different heating systems is considered as a major factor (threat) in air pollution.

2021 ◽  
Vol XXVIII (4) ◽  
pp. 121-132
Author(s):  
Corina Chelmenciuc ◽  
◽  
Constantin Borosan ◽  
Vadim Lisnic ◽  
◽  
...  

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.


2014 ◽  
Vol 535 ◽  
pp. 309-314
Author(s):  
Dian Zheng Fu ◽  
Guo He Huang

In this study, fuel supply optimization model coupled with environmental emission standard and heat demond prediction was applied in the district heating system of a new economic district in the middle part of Liaoning Province. The model results indicate that the coals from different sources and the use of nature gas are influenced while the component ratio of each coal type in coal bending is not influenced by the thermalization coefficient. Moreover, the results also shows that the thermalization coefficient can be regulated by the decision maker of the district heating system, resulting in redistributing the heat supplies between the main heat supply source and peak-shaving heat supply source in order to further obtain the reasonable heating alternative, which has both the economic and environmental merits for the residential users.


2021 ◽  
Vol 58 (3) ◽  
pp. 121-136
Author(s):  
D. Rusovs ◽  
L. Jakovleva ◽  
V. Zentins ◽  
K. Baltputnis

Abstract To develop an advanced control of thermal energy supply for domestic heating, a number of new challenges need to be solved, such as the emerging need to plan operation in accordance with an energy market-based environment. However, to move towards this goal, it is necessary to develop forecasting tools for short- and long-term planning, taking into account data about the operation of existing heating systems. The paper considers the real operational parameters of five different heating networks in Latvia over a period of five years. The application of regression analysis for heating load dependency on ambient temperature results in the formulation of normalized slope for the regression curves of the studied systems. The value of this parameter, the normalized slope, allows describing the performance of particular heating systems. Moreover, a heat load forecasting approach is presented by an application of multiple regression methods. This short-term (day-ahead) forecasting tool is tested on data from a relatively small district heating system with an average load of 20 MW at ambient temperature of 0 °C. The deviations of the actual heat load demand from the one forecasted with various training data set sizes and polynomial orders are evaluated for two testing periods in January of 2018. Forecast accuracy is assessed by two parameters – mean absolute percentage error and normalized mean bias error.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3218
Author(s):  
Pedro Durán ◽  
Herena Torio ◽  
Patrik Schönfeldt ◽  
Peter Klement ◽  
Benedikt Hanke ◽  
...  

There are 1454 district heating systems in Germany. Most of them are fossil based and with high temperature levels, which is neither efficient nor sustainable and needs to be changed for reaching the 2050 climate goals. In this paper, we present a case study for transforming a high to low temperature district heating system which is more suitable for renewable energy supply. With the Carnot Toolbox, a dynamic model of a potential district heating system is simulated and then transformed to a low temperature supply. A sensitivity analysis is carried out to see the system performance in case space constrains restrict the transformation. Finally, an economic comparison is performed. Results show that it is technically possible to perform the transformation until a very low temperature system. The use of decentralized renewable sources, decentralized heat storage tanks and the placement of a heat pump on each building are the key points to achieve the transformation. Regarding the sensitivity analysis, the transformation is worth doing until the seasonal storage and solar collector field sizes are reduced to 60% and 80% of their values in the reference case, respectively. The economic analysis shows, however, that it is hard for highly efficient low temperature renewable based heat networks to compete with district heating systems based on a centralized fossile CHP solution. Thus, though the presented transformation is technically possible, there is a strong need to change existing economic schemes and policies for fostering a stronger promotion of renewable energy policies in the heat sector.


Author(s):  
Tetiana Zheliuk

Introduction. One of the main directions of ensuring the sustainable development of the national economy and its regions is the reform of the energy sector, which can take place through the modernization or innovation of its components. An important component of these reforms is to provide the population with the environmentally friendly and socially safe thermal energy. At the present stage of management, the heat supply is the most costly branch of public utilities, which is supplemented by the problems of the inefficient fuel balance structure; worn-out infrastructure and low energy efficiency. This highlights the need to study the management of modernization of the heat supply system in the region in view of the declared vectors of the long-term development. Object of research is the process of managing the modernization of the heat supply system in the region. Subject of the research is a set of scientific approaches and practical mechanisms of modernization of the heat supply system of the region in the context of ensuring its sustainable development. Objective. The conceptual foundations of modernization of the heat supply system of the region in the context of its sustainable development through the introduction of the innovative technologies both in the management process and in the energy sector itself is substantiated in the paper. Methods. The following general scientific methods were used during the research process: system, structural analysis, grouping, when studying the structural elements and isolation of problems of development of the heat supply system of the region; historical analysis, when considering the scientific principles and institutional mechanism of modernization of the region’s heat supply system; comparative analysis in assessing the possibilities of the green transition of the heat supply system of the region and also when considering the features of the use of grant resources in the modernization of the heat supply system of the region; economic analysis in assessing the current state of the district heating system, etc. results. The essential determinants of the heat supply system of the region are analyzed, the objective need, organizational and economic mechanisms for managing the modernization of the heat supply, taking into account the need for the balanced development of the energy sector of the region are verified. The scientific novelty of the obtained results lies in the substantiation of the conceptual approaches to the management of modernization of the heat supply system of the region by innovating the forms and methods of managerial influence on the heat supply system of the region. The conclusion is made about the following effective approaches in managing the modernization of the district heating system: planning of the sustainable development of the energy sector, development of programs for modernization of the district heating, implementation of the infrastructure and soft projects, implementation of the international projects, motivation of households and entrepreneurship in the heat sector, participation in the grant requests, in state crediting programs, realization of the business projects in the field of production of environmentally friendly fuel; conducting an information campaign among the population and other key market players to raise the awareness of the energy efficiency financing mechanisms. The practical significance of the obtained results is that the developed recommendations will be used to improve the organizational and economic mechanism of management of the district heating system modernization and ensure its sustainable development.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Fisnik Dalipi ◽  
Sule Yildirim Yayilgan ◽  
Alemayehu Gebremedhin

We present our data-driven supervised machine-learning (ML) model to predict heat load for buildings in a district heating system (DHS). Even though ML has been used as an approach to heat load prediction in literature, it is hard to select an approach that will qualify as a solution for our case as existing solutions are quite problem specific. For that reason, we compared and evaluated three ML algorithms within a framework on operational data from a DH system in order to generate the required prediction model. The algorithms examined are Support Vector Regression (SVR), Partial Least Square (PLS), and random forest (RF). We use the data collected from buildings at several locations for a period of 29 weeks. Concerning the accuracy of predicting the heat load, we evaluate the performance of the proposed algorithms using mean absolute error (MAE), mean absolute percentage error (MAPE), and correlation coefficient. In order to determine which algorithm had the best accuracy, we conducted performance comparison among these ML algorithms. The comparison of the algorithms indicates that, for DH heat load prediction, SVR method presented in this paper is the most efficient one out of the three also compared to other methods found in the literature.


2018 ◽  
Vol 45 ◽  
pp. 00005 ◽  
Author(s):  
Bożena Babiarz ◽  
Paweł Kut

District heating systems as strategic objects from the point of view of state security must ensure reliability and security in supply of heat to their customers [1, 2]. Thanks to computer simulation methods, district heating companies can analyse the operation of the heating networks at the design and operation stage. Computer simulations also offer a wide range of possibilities in the aspect of optimization of the district heating operation as well as prediction and analysis of network failure effects [3-6]. The paper concerns the simulation of a district heating network. The methods for the simulation of heating networks were characterized and simulations of district heating system were carried out. The effects of the failure were analysed at different values of outside temperatures and for different durations of failure. The value of compensation for undelivered heat was also determined. Simulations were carried out for an actual district heating system located in Rzeszow.


Buildings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Amir Vadiee ◽  
Ambrose Dodoo ◽  
Elaheh Jalilzadehazhari

Floor heating and radiators are two of the most common types of hydronic heating systems used for space heating in single-family houses in cold climate regions. Notwithstanding, there are few comparative studies on indoor temperature distribution and system cost evaluations for radiators and floor heating. Furthermore, there are no aligned outcomes in terms of total heat supply for a single-family house with radiators or floor heating. In this study, the effect of building energy efficiency level and construction type, including flooring material, on the supply heating demand and transmission heat losses were studied for both radiator and floor heating systems. For this purpose, a single-family house located in Växjö, Sweden, was modeled as a case study. The heating demand was supplied with a district heating system with a similar supply temperature at 45 °C for both the radiator and floor heating system. A sensitivity analysis was also performed to assess the effect of flooring configurations on the annual supply heating demand for both conventional and passive versions of the case-study building. The results showed that the radiator-integrated building had a lower supply heating demand in comparison with the floor heating-integrated buildings. Based on the sensitivity studies, the flooring material did not have a significant influence on the supply heating demand and on the transmission heat losses in the case of the radiators. The supply heating demand was only reduced up to 3% if the flooring U-value was improved by 60%. The results also showed that refurbishment in a standard conventional building with a radiator heating system based on the passive criteria led to a 58% annual energy savings, while this amount for a building with a floor heating system was approximately 49%.


Author(s):  
Krzysztof Badyda ◽  
Wojciech Bujalski ◽  
Jarosław Milewski ◽  
Michał Warchoł

Heat accumulators in large district heating systems are used to buffer heat production. Their main purpose is to make heat production as independent as possible from district heating system demand. To do this effectively a heat accumulator of appropriate capacity must be selected. In large district heating systems, heat accumulators can be used for equalising production over periods lasting a few hours. Accumulators can be used for optimising electricity and heat production to achieve possible highest income. It may be important in situations where on-line prices change. An optimising algorithm for heat accumulator use is shown and commented. Typical working situations are simulated and results presented.


2014 ◽  
Vol 638-640 ◽  
pp. 2101-2105
Author(s):  
Lin Hua Zhang ◽  
Dong Yang ◽  
Ting Ting Chen ◽  
Shou Jun Zhou ◽  
Ling Liu

In this paper, we shall first briefly introduce the hydraulic junction of three-sources branched heat-supply network and the related optimization method. It's difficult to guarantee that the system runs in optimal state and it increases energy consumption in the system. In view of this situation this paper proposes a method to find the optimal positions of hydraulic intersections based on analyzing a real heating system with three heat sources in Jining. The optimization objective is to minimize the electric power consumption of circulating water pumps in district heating system. Finally, optimization programs are designed and the optimized results verify the feasibility and validity of the method compared with conventional experience values.


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