scholarly journals HEAT MODES OF THE HEATING NETWORK IN WARMING BUILDINGS

2020 ◽  
Vol 1 (154) ◽  
pp. 159-164
Author(s):  
A. Aleksahin ◽  
A. Boblovskey ◽  
К. Zhariy ◽  
J. Sidorenko ◽  
М. Skorik
Keyword(s):  
Energy Saving ◽  
Heat Loss ◽  
Heat Supply ◽  
District Heating ◽  
Heating System ◽  
Heat Losses ◽  
Transfer Resistance ◽  
Maximum Heat ◽  
Heating Systems ◽  
Network Water

The results of calculations of heat losses by network pipelines for heating of idealized groups of buildings during insulation of structures are presented in the work. Formulas for estimation of heat loss reduction by heat conduits are proposed depending on the efficiency of energy saving measures for construction and the law of change of network water costs along the length of the heat conduit, which is determined by the network configuration. The purpose of this work is to evaluate the influence of the hydraulic characteristics of the branches of the heating network on the magnitude of heat losses during transportation of the coolant by pipelines of the distribution network to buildings. Idealized groups of buildings with the same number of objects and the same maximum heat consumption for heating of a separate building are considered. For district heating systems, the efficiency of implementing energy-saving measures for buildings is determined not only by the reduction of heating costs, but also by the change in operating costs for the microdistrict heating network, which is caused by the reduction of heat carrier costs and heat losses by heating system pipelines. The magnitude of the heat loss depends on the method of laying the networks, the parameters of the pipeline insulation, the temperature of the coolant, and the environment. In the case of selective insulation of the buildings of the selected group of buildings, the location of the insulated building is significantly influenced by the amount of heat losses by the pipelines. In case of centralized heat supply, a fragment of the construction load decrease due to the insulation of buildings and the reduction of the network water temperature in the space heating devices causes the reduction of heat losses by the pipelines of the distribution thermal networks. The magnitude of the reduction of heat losses by heat pipelines is determined by the degree of efficiency of insulation of buildings, the nature of changes in the cost of the coolant along the length of the branch of the thermal network and practically does not depend on the magnitude of the heating load of buildings. Keywords: centralized heat supply, centralized heating systems, energy saving, heat transfer resistance, enclosing structures, coefficient of efficiency of building insulation, distribution thermal networks, heat loss by pipelines.

scholarly journals Calculation Of Heat Loss Through The Pipes Of The Interior Central Heating System

2015 ◽  
Vol 5 (2) ◽  
pp. 29-36 ◽  
Author(s):  
I. Giurca
Keyword(s):  
Heat Loss ◽  
Heating System ◽  
Building Energy ◽  
Local Heat ◽  
Heat Losses ◽  
Energy Audit ◽  
Heating Systems ◽  
Central Heating ◽  
Calculation Methodology

Abstract The article presents aspects related to the calculation of heat loss through the pipes of the interior central heating system. The purpose of the article is to detail the local heat losses in case of central heating systems. Based on the conclusions of the article, we propose the modification of the calculation methodology related to the building energy audit.

scholarly journals Heat Supply Comparison in a Single-Family House with Radiator and Floor Heating Systems

Buildings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Amir Vadiee ◽  
Ambrose Dodoo ◽  
Elaheh Jalilzadehazhari
Keyword(s):  
Heat Supply ◽  
Heating System ◽  
Heat Losses ◽  
Cold Climate ◽  
Single Family ◽  
Heating Systems ◽  
Family House ◽  
Flooring Material ◽  
Floor Heating

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%.

scholarly journals Technology Pathways and Economic Analysis for Transforming High Temperature to Low Temperature District Heating Systems

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3218
Author(s):  
Pedro Durán ◽  
Herena Torio ◽  
Patrik Schönfeldt ◽  
Peter Klement ◽  
Benedikt Hanke ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Renewable Energy ◽  
High Temperature ◽  
Low Temperature ◽  
Economic Analysis ◽  
District Heating ◽  
Heating System ◽  
District Heating System ◽  
Heating Systems ◽  
District Heating Systems

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.

scholarly journals Overview of Solutions for the Low-Temperature Operation of Domestic Hot-Water Systems with a Circulation Loop

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3350
Author(s):  
Theofanis Benakopoulos ◽  
William Vergo ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Svend Svendsen
Keyword(s):  
Low Temperature ◽  
Heat Loss ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Heating Power ◽  
Circulation Loop ◽  
Space Heating ◽  
District Heating System ◽  
Domestic Hot Water

The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.

scholarly journals METHODOLOGY OF THE PRIMARY DATA RECONSTRUCTION OF SINGLE PIPE HEATING SYSTEMS/VIENVAMZDŽIŲ ŠILDYMO SISTEMŲ PIRMINIŲ DUOMENŲ NUSTATYMO METODIKA

1999 ◽  
Vol 5 (5) ◽  
pp. 318-322
Author(s):  
Edvardas Tuomas ◽  
Saulius Neverbickas
Keyword(s):  
World War Ii ◽  
District Heating ◽  
Heating System ◽  
Heat Fluxes ◽  
Primary Data ◽  
Complex Coefficient ◽  
Heating Systems ◽  
Pipe System ◽  
Central Heating ◽  
Single Pipe

The majority of dwellings in Lithuania are situated in blocks of flats. The dwellings were built after World War II and they are heated by single pipe central heating systems, connected to district heating. The dwellers are not quite satisfied with such a heating system and try to improve it, but do that in a wrong way, by increasing the surface of radiators. Such means lead to violation of thermal regime and comfort conditions for other dwellers. There exists sometimes the necessity of reconstructing premises and together—the heating system. During the reconstruction the primary heat fluxes from radiators should be known, but very often such data are lost and only the size of radiators (number of sections) are known. To reconstruct the required primary data for single pipe systems is complicated because the temperatures of inlet and outlet water for radiators are unknown. In this article the methodology is proposed how to perform the calculations leading to the required data. The aim of calculations is the establishment of heat fluxes from each radiator connected to the riser. Heat flux from radiator can be calculated according the formula (1) but the complex coefficient is unknown. It could be found from formulae (2) but some magnitudes are unknown. According to the proposed methodology the values of unknown magnitudes are taken approximately and calculations are performed with iterations. In such a way the flow rate of water in riser is established from formula (3), which is the same for each radiator (the property of single pipe system). From formulas (3) and (4) an equation is produced (5), and is used for calculations of unknown temperatures. The equation (6) is used for calculation of heat fluxes from radiators. To carry out the above-mentioned calculations without computer practically is impossible due to many cycles of iteration. The programme was prepared to make easy all these calculations. The scheme of algorithm of programme is given in Fig 1. An example of calculation is given in this article. Calculations were fulfilled by newly created programme. The riser chosen for calculation is shown in Fig 2. The results of calculation are given in Table 1. The table shows that according to the proposed methodology the programme based on it can be used for reconstruction of primary data of single pipe heating systems successfully.

scholarly journals Technological Innovation in the Aspect of Safety in the Process of Heat Supply

2019 ◽  
Vol 1 (1) ◽  
pp. 412-418
Author(s):  
Aleksandra Wrzalik ◽  
Matevž Obrecht
Keyword(s):  
Energy Efficiency ◽  
Heat Supply ◽  
Renewable Energy Sources ◽  
District Heating ◽  
High Energy ◽  
The European Union ◽  
Heating Systems ◽  
Operation Conditions ◽  
Network Operation ◽  
The Impact

AbstractIn recent years heating in Poland has been transformed as a result of the priorities of the country's energy policy implemented within the European Union. The increase in energy security, the development of renewable energy sources and the fulfilment of legal and environmental requirements are very important. Exploitation of district heating systems should ensure reliable and safe heat supplies for industrial and municipal customers with high energy efficiency and reduction of environmental impact. The article discusses the conditions and directions of centralized heating systems development as well as technical and economic issues, which are important for the security of heat supply. The Author describes selected technological innovations used in the technical infrastructure for heat transfer and modern IT systems which are improving the management of heating systems. The article includes the results of simulation research with use of IT tools showing the impact of selected innovations on the improvement of network operation conditions. Directions of modernization of heating systems in the aspect of increasing energy efficiency and security of heat supply have also been indicted here.

scholarly journals Management of modernization of heat supply system of the region in the context of its sustainable development

2020 ◽  
pp. 20-36
Author(s):  
Tetiana Zheliuk
Keyword(s):  
Energy Efficiency ◽  
Sustainable Development ◽  
Heat Supply ◽  
District Heating ◽  
Heat Supply System ◽  
Heating System ◽  
Energy Sector ◽  
Supply System ◽  
District Heating System ◽  
The Sustainable Development

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.

scholarly journals The influence of heat loss from pipes in an unheated basement on the heating energy consumption of an entire typical apartment building

2020 ◽  
Vol 172 ◽  
pp. 12005
Author(s):  
Anti Hamburg ◽  
Targo Kalamees
Keyword(s):  
Energy Balance ◽  
Heat Loss ◽  
District Heating ◽  
Building Energy ◽  
Energy Performance ◽  
Heat Losses ◽  
Hot Water ◽  
Limited Information ◽  
Apartment Building ◽  
Heating Energy Consumption

The majority of old apartment buildings were designed with an unheated basement. Building service systems such as district heating heat exchangers and pipes for domestic hot water and for space heating are usually located in this unheated basement. In addition, these locations are connected with shafts. All these pipe’s heat losses increase air temperature in the basement. If these losses are included into the building energy balance, then they decrease heat loss through the basement ceiling. The basement’s heat balance is also dependent on heat loss from the basement envelope and outdoor air exchange in the basement. In early stages of design, designers and energy auditors need rough models to make decisions in limited information conditions. Once the effects of heat losses from pipes become apparent, they need to be factored into the buildings energy balance, and their effects on heat loss through the basement ceiling needs to be calculated. In this paper we analyse the effect these heat losses have on the service system’s heat gains and heat loss through an uninsulated basement ceiling at different basement insulation levels and with different thicknesses of pipe insulation. From our study we found that pipe losses in the basement increase the building energy performance value by at least 4 kWh/(m²∙a) and their impact on a renovated apartment building is very important.

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