The Three-Pipe-System of the BEWAG District Heating

1980 ◽  
pp. 89
Keyword(s):  
District Heating ◽  
Pipe System

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 New Dimensionless Correlations for the Evaluation of the Thermal Resistances of a District Heating Twin Pipe System

2021 ◽  
Vol 11 (20) ◽  
pp. 9685
Author(s):  
Massimo Corcione ◽  
Luca Cretara ◽  
Lucia Fontana ◽  
Alessandro Quintino
Keyword(s):  
Thermal Resistance ◽  
Control Volume ◽  
District Heating ◽  
Heat Losses ◽  
Thermal Engineering ◽  
Thermal Conductivity Ratio ◽  
Burial Depth ◽  
Pipe System ◽  
Double Pipe ◽  
Dimensionless Correlations

The heat losses from pre-insulated double-pipe district heating (DH) systems buried in a homogeneous soil are studied numerically. The study is conducted using the diameter of the pipes and their distance, the size of the insulation, the thermal conductivity ratio between the insulation and the soil, as well as the burial depth of the double-pipe system, as controlling parameters. A computational code based on a control-volume formulation of the finite-difference method has been developed using the open-source framework OpenFOAM with the purpose to compute the heat transfer rate across adjacent solid regions with different thermophysical properties. The main scopes of the study are: (a) to investigate in what measure the geometry and the relative position of the warm and cold pipes, as well as the temperature imbalance, the burial depth and the physical properties of both the insulation and the soil, affect the heat losses; (b) to analyze the existence of an optimal configuration of the DH system by the thermal resistance enhancement viewpoint; and (c) to develop accurate correlating equations for the evaluation of the thermal resistance existing between each pipe and its surroundings, useful for practical thermal engineering applications.

Coupled Pump and Pipe System Analysis for Optimum Design of District Heating System

2017 ◽  
Author(s):  
Magnus Thor Jonsson ◽  
Lilja Magnusdottir
Keyword(s):  
Objective Function ◽  
System Analysis ◽  
District Heating ◽  
Heating System ◽  
System Optimization ◽  
Operational Cost ◽  
District Heating System ◽  
Pipe System ◽  
Pump Station ◽  
Optimization Parameters

This paper describes a novel approach for optimizing a district heating distribution network under various flow rate conditions. For district heating systems, the demand or the flow and pressure at each node varies over the time of year. The flow control that affects the operational cost can be based on the variable speed and the on/off control on serial pumping or pressure controlled valves. In the pipe system design, the topology, or the pipe layout, and the pipe diameter is optimized using genetic algorithms. Standardized methods are used for calculating the pipe thickness, supports, anchors and the thermal expansion loops. The interconnection between the pipe system and the pump station design is discussed. The objective is to minimize the total or life cycle cost (capital maintenance and operational cost), subject to ensuring demands or constraints at all points. The results are compared to classical methods where the pump station and the pipe system are designed separately and the improvements are discussed. The problem is formulated by developing an objective function where the optimization parameters define the pump arrangement, pipe system topology, and pipe diameters. The pump station and pipe system optimization consist of selecting components from a pre-defined set of elements and is implemented with discrete decision variables. Optimization of pipe elements consists of optimizing the diameter, after the topology has been defined, and is implemented with discrete variables. Flow distribution and pressure analysis is performed. Thicknesses, pressure classes, supports, expansion loops and anchors are not part of the optimization parameters, but are determined during the evaluation of the objective function. Each time the objective function is evaluated, the pipe system is designed in a sub-optimization according to given loads. The pressure head constraints are used to design the pumping curves. The method is tested on a district heating system in Reykjavik, Iceland.

Life Cycle Assessment of the District Heating Distribution System in China — Network Construction

2012 ◽  
Vol 256-259 ◽  
pp. 2662-2666
Author(s):  
Zhen Li ◽  
Wei Wei Wang ◽  
Hong Ming Sun
Keyword(s):  
Life Cycle ◽  
Environmental Impact ◽  
Distribution System ◽  
Technical Specification ◽  
District Heating ◽  
Steel Tubes ◽  
Total Consumption ◽  
Weighting Method ◽  
Welded Steel ◽  
Pipe System

In China, the environmental impact from the construction of the distribution system is seldom discussed. In this study, the environmental impact from construction of district pipes is considered. The purpose is to identify environmental significant parts in the construction of district pipes and to use the results in the actual projects including once more parts of the district distribution system have been investigated with LCA methodology.(Methods) Construction of district pipe networks according to the technical specification was studied. The total consumption of energy and materials was calculated based on budget norm for projects. The functional unit used in the study is construction of 100 metres of pipe system. The studied pipes are: pipe of the dimension DN100, DN200 (Seamless steel tubes) and DN500 (spirally welded steel tubes) .Urban environment surroundings were studied. A short description of the inventory, some inventory results and a life cycle impact assessment are presented. Based on the concept of the End-point damage weighting method, the total environment load is given.

Shape Design of Bends in District Heating Pipe System by Taguchi Method

2010 ◽  
Vol 34 (3) ◽  
pp. 307-313 ◽  
Author(s):  
Moon-Deok Choi ◽  
Joo-Yong Kim ◽  
Hyun-Il Ko ◽  
Chong-Du Cho
Keyword(s):  
Taguchi Method ◽  
District Heating ◽  
Shape Design ◽  
Pipe System

scholarly journals Data base for district heating pipe system design

1979 ◽  
Author(s):  
R Lesse ◽  
J Karkheck ◽  
H Serry ◽  
R Tessmer
Keyword(s):  
System Design ◽  
Data Base ◽  
District Heating ◽  
Pipe System

CONCEPTUAL POSITIONS OF MODERNIZATION OF EXISTING INEFFICIENT DISTRICT HEATING SYSTEMS

2017 ◽  
pp. 11-21
Author(s):  
Ye.Ye. Nikitin
Keyword(s):  
Energy Efficient ◽  
Mutual Influence ◽  
District Heating ◽  
Current Status ◽  
Cognitive Approach ◽  
Heating Systems ◽  
Energy Management Systems ◽  
Current State ◽  
Self Sufficiency ◽  
District Heating Systems

The current situation in the sphere of district heating is analysed on the basis of use of the cognitive approach. The presence of closed chains of cause-effect relationships of negative factors and conflicts of target settings of the subjects in the field of district heating is shown. The conceptual model of energy efficient modernization of district heating systems is proposed. This model includes indicators of the current status of heat sources, networks and heat consumers, energetic and economic models, restrictions, procedure of forming and analysis of the mutual influence of the recommended projects. The quantitative data on indicators of the current state of district heating systems of the cities of Ukraine are presented. The interrelation between indicators of the current state and projects of energy efficient modernization of district heating systems is shown. Assessment of energy self-sufficiency of municipal district heating systems on condition of thermal modernization of buildings is carried out. The creation of energy management systems at the district heating enterprises is proposed. Bib. 6, Fig. 7, Tab. 5.

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