APPLICATION OF MODERN PRE-INSULATED PIPES TO INCREASE THE ENERGY EFFICIENCY OF CENTRALIZED HEAT SUPPLY SYSTEMS

2020 ◽  
Vol 42 (4) ◽  
pp. 74-82
Author(s):  
I.K. Bozhko
Keyword(s):  
Thermal Conductivity ◽  
Polyurethane Foam ◽  
Thermal Insulation ◽  
Diffusion Barrier ◽  
Thermal Characteristics ◽  
District Heating ◽  
Environmental Parameters ◽  
Heating System ◽  
District Heating System ◽  
Heating Networks

The article is devoted to a review of manufacturing technologies and methods for counteracting the effects of aging and destruction of a ball of thermal insulation in previously insulated pipes (PIP) of heating networks. The thermophysical characteristics of various blowing agents are compared; the superiority of cyclopentane in both thermophysical and environmental parameters is shown. The basic technologies for the production of pre-insulated pipe wires are considered. The advantages of «conti» technology using a diffusion barrier are highlighted. It is shown that for polyurethane foam, the main factor that suppresses heat transfer through PUR type thermal insulation is the low thermal conductivity of the gas mixture, which is "sealed" in the foam cells. The analysis of the influence of “aging” of the heat-insulating shell, namely, the diffusion of oxygen molecules into the structure of polyurethane foam, is carried out, and its negative effect on the thermal characteristics of the heat-insulating material is shown. Oxygen diffusion leads to a gradual increase in the value of the coefficient of thermal conductivity of the heat-insulating shell, and as a result, increases heat loss by the pipeline. The results of predictive calculations confirmed the effectiveness of the use of diffusion barriers in the manufacture of PIP. It is shown that when using PIP with a diffusion barrier, unproductive heat energy losses decrease on average by 20–21%, which, in turn, leads to a decrease in the amount of payments to end consumers and an increase in the quality and efficiency of district heating systems. It is also noted that polymer pre-insulated pipelines are practically not inferior in strength and reliability to steel PIP and at the same time, they have several advantages over steel PIP. It is recommended to increase the use of polymer PIP in the reconstruction of heating networks of the district heating system.

scholarly journals District heating simulation in the aspect of heat supply safety

2018 ◽  
Vol 45 ◽  
pp. 00005 ◽  
Author(s):  
Bożena Babiarz ◽  
Paweł Kut
Keyword(s):  
District Heating ◽  
Heating System ◽  
Point Of View ◽  
Simulation Methods ◽  
District Heating System ◽  
Heating Systems ◽  
Network Failure ◽  
State Security ◽  
Wide Range ◽  
Heating Networks

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.

scholarly journals Methodology for the Improvement of Large District Heating Networks

2012 ◽  
Vol 10 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Anna Volkova ◽  
Vladislav Mashatin ◽  
Aleksander Hlebnikov ◽  
Andres Siirde
Keyword(s):  
Heat Generation ◽  
Large Scale ◽  
Renewable Energy Sources ◽  
District Heating ◽  
Heating System ◽  
District Heating System ◽  
Effective Operation ◽  
The Cost ◽  
Heating Networks

Abstract The purpose of this paper is to offer a methodology for the evaluation of large district heating networks. The methodology includes an analysis of heat generation and distribution based on the models created in the TERMIS and EnergyPro software Data from the large-scale Tallinn district heating system was used for the approbation of the proposed methodology as a basis of the case study. The effective operation of the district heating system, both at the stage of heat generation and heat distribution, can reduce the cost of heat supplied to the consumers. It can become an important factor for increasing the number of district heating consumers and demand for the heat load, which in turn will allow installing new cogeneration plants, using renewable energy sources and heat pump technologies

scholarly journals INVESTIGATION OF THE FREQUENCY OF DAMAGE TO HEATING NETWORKS

2020 ◽  
Vol 6 (159) ◽  
pp. 36-49
Author(s):  
V. Grankina ◽  
O. Maliavina ◽  
V. Milanko
Keyword(s):  
Service Life ◽  
District Heating ◽  
Heating System ◽  
Engineering Systems ◽  
Monthly Basis ◽  
District Heating System ◽  
Reliability Indicators ◽  
Labor Resources ◽  
Object Of Study ◽  
Heating Networks

This article is devoted to improving the efficiency of planning the consumption of material and technical and labor resources and their appropriate planning for heating and non-heating periods, by months of the year based on the calculation of the estimated number of damage to heating pipes, based on the obtained dependences of failure rate. This task is modern and relevant especially in conditions of limited funding of engineering systems. The object of study - the district heating system. The subject of research - pipelines of thermal networks. The purpose of the work is to determine the distribution of damage to the heating network pipelines by months. The research method is statistical modeling of damages of heating network pipelines by months of the year for different terms of their operation. Currently, the reliable operation of district heating systems and their heating networks is one of the main factors in the livelihood of settlements. The reliability of heating network pipelines is determined by the reliability indicators obtained on the basis of data on the damage of heating pipelines. Studying the distribution of the number of damages of heating network pipelines by months depending on the service life of heating pipelines is necessary for effective planning of material, technical and labor resources. In order to increase the efficiency of planning of material and technical and labor resources, it is advisable to calculate the number of damages for the heating and unheated periods, by months of the year, by decades. The calculated dependences of the distribution of damage to the pipelines of heating networks for the heating and non-heating periods on a monthly basis, decadally, should take into account the service life of the pipelines. The results of the above research will save material, technical, labor and energy resources.

scholarly journals Energy savings for residential heating in two pairs of buildings achieved by implementation of actually consumed energy measuring

2006 ◽  
Vol 10 (4) ◽  
pp. 79-88
Author(s):  
Branislav Zivkovic ◽  
Maja Todorovic ◽  
Petar Vasiljevic
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Thermal Characteristics ◽  
District Heating ◽  
Heating System ◽  
Total Energy Consumption ◽  
District Heating System ◽  
Residential Heating ◽  
Heating Energy Consumption ◽  
And Control

The paper presents results of heating energy consumption measurements in two pairs of buildings in community New Belgrade for two heating seasons. Influence of these measurements on energy savings is also presented. The measurements were carried out during heating seasons 2002/03 and 2003/04 in buildings in Block 34 and 63, connected to the district heating system "Beogradske elektrane". The buildings in each pair have similar architectural and thermal characteristics. One of the buildings in a pair was "test" building and the other "control" one. In the "test" building the energy consumption for heating of each apartment was measured, as well as total energy consumption for the whole building in the substation. Occupants were able to regulate the heating system. In the "control" building the energy consumption was measured only for the whole building, and occupants had almost no impact on heating energy consumption. The comparison of energy consumption for heating in the "test" and "control" buildings is given in the paper, as well as analysis of the influence of energy consumption measurements on the achieved energy savings. .

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.

Predicting Hourly Heating Load in a District Heating System Based on a Hybrid CNN-LSTM Model

2021 ◽  
pp. 110998
Author(s):  
Jiancai Song ◽  
Liyi Zhang ◽  
Guixiang Xue ◽  
YunPeng Ma ◽  
Shan Gao ◽  
...  
Keyword(s):  
District Heating ◽  
Heating System ◽  
District Heating System ◽  
Heating Load

scholarly journals Upgrading a District Heating System by Means of the Integration of Modular Heat Pumps, Geothermal Waters, and PVs for Resilient and Sustainable Urban Energy

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2347
Author(s):  
Elżbieta Hałaj ◽  
Jarosław Kotyza ◽  
Marek Hajto ◽  
Grzegorz Pełka ◽  
Wojciech Luboń ◽  
...  
Keyword(s):  
District Heating ◽  
Heating System ◽  
Upper Jurassic ◽  
Heat Pumps ◽  
Water Levels ◽  
Energy Potential ◽  
Geothermal Waters ◽  
District Heating System ◽  
Heating And Cooling ◽  
The City

Krakow has an extensive district heating network, which is approximately 900 km long. It is the second largest city in terms of the number of inhabitants in Poland, resulting in a high demand for energy—for both heating and cooling. The district heating of the city is based on coal. The paper presents the conception of using the available renewable sources to integrate them into the city’s heating system, increasing the flexibility of the system and its decentralization. An innovative solution of the use of hybrid, modular heat pumps with power dependent on the needs of customers in a given location and combining them with geothermal waters and photovoltaics is presented. The potential of deep geothermal waters is based on two reservoirs built of carbonate rocks, namely Devonian and Upper Jurassic, which mainly consist of dolomite and limestone. The theoretical potential of water intake equal to the nominal heating capacity of a geothermal installation is estimated at 3.3 and 2.0 MW, respectively. Shallow geothermal energy potential varies within the city, reflecting the complex geological structure of the city. Apart from typical borehole heat exchangers (BHEs), the shallower water levels may represent a significant potential source for both heating and cooling by means of water heat pumps. For the heating network, it has been proposed to use modular heat pumps with hybrid sources, which will allow for the flexible development of the network in places previously unavailable or unprofitable. In the case of balancing production and demand, a photovoltaic installation can be an effective and sufficient source of electricity that will cover the annual electricity demand generated by the heat pump installation, when it is used for both heating and cooling. The alternating demand of facilities for heating and cooling energy, caused by changes in the seasons, suggests potential for using seasonal cold and heat storage.

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