scholarly journals Investigation of thermohydraulic dispatcher properties and peculiarities

2019 ◽  
Vol 124 ◽  
pp. 01009 ◽  
Author(s):  
D. O. Romanov ◽  
Y. V. Yavorovsky
Keyword(s):  
Thermal Stratification ◽  
Electricity Consumption ◽  
District Heating ◽  
Differential Pressure ◽  
Insufficient Information ◽  
Flow Rates ◽  
Heating Systems ◽  
District Heating Systems ◽  
Hydrodynamic Separation ◽  
Supply Systems

Application of thermohydraulic dispatcher (THD) for district heating systems is, to some extent, limited due to insufficient information about its properties and features. At the same time this device has a potential to solve the problem of mutual dependence of heat consumers and to decrease electricity consumption in heat supply systems. This paper deals with experimental research and numerical simulation of THD with the aim of increasing the range of knowledge about its properties. Presented results describe already known properties such as near-to-zero differential pressure at THD and flow rates independence which were checked. Some new properties and peculiarities of THD were obtained during the investigation as well. Among them is differential pressure “variability”, hydrodynamic separation under higher velocity, similarity of thermohydraulic processes inside THD under similar velocities in manifolds of THD, absence of thermal stratification in mixing regime, dependence of secondary circuits supply temperature from the height level and secondary circuits return temperature.

scholarly journals Feasibility study of conventional, DVSP, and THD-based heat supply systems

2019 ◽  
Vol 124 ◽  
pp. 04007 ◽  
Author(s):  
D. O. Romanov ◽  
Y. V. Yavorovsky
Keyword(s):  
Heat Source ◽  
Heat Supply ◽  
Electricity Consumption ◽  
District Heating ◽  
Variable Speed ◽  
Conventional System ◽  
Heating Systems ◽  
Hydrodynamic Separation ◽  
Discounted Costs ◽  
Supply Systems

Thermohydraulic dispatcher (THD) can be widely used in district heating systems. Heat source is one of the possible places of its application. In this case, it is possible to achieve hydrodynamic separation of heat source and heat supply network. This paper deals with comparison of three types of heat substation connection to heat source: conventional system, DVSP system, THD-based system. The latter two have variable speed pumps instead of throttling valves. Based on electricity consumption and investment costs calculations, total discounted costs of three systems were estimated. In result, DVSP system is more beneficial, while conventional system and THD-based system have high operational and investment costs accordingly.

scholarly journals Improving the efficiency of heat release regulation in centralized heat supply systems

2020 ◽  
pp. 81-97
Author(s):  
O Shelimanova ◽  
◽  
A. Kolienko ◽  
Keyword(s):  
Energy Source ◽  
Energy Efficiency ◽  
Control Systems ◽  
Heat Supply ◽  
Heat Dissipation ◽  
District Heating ◽  
Heating Systems ◽  
District Heating Systems ◽  
Heat Supply Systems ◽  
Supply Systems

Ensuring optimal hydraulic and thermal regimes in district heating systems (DHS) in the regulation of heat supply is an important factor in improving the energy and economic efficiency of DHS. In addition, high efficiency of the HS system is a factor that can ensure the preservation of its vital functions. Solving the problem of increasing the energy efficiency of the heat supply system is a complex problem that requires changes at all stages of heat transformation: in the energy source, heating networks and subscriber heating systems of heat consumers. The purpose of this study is to identify the impact of heat dissipation control processes in district heating systems on their energy and economic efficiency, provide recommendations for improving control processes taking into account modern challenges and regulatory requirements, analyze heat dissipation temperature schedules and select the optimal temperature schedule. It is shown that the optimal is the combined quantitative and qualitative regulation of heat release, which should be carried out both at the energy source and at consumers. The paper considers the possibility of using combined control systems in the existing district heating systems of Ukrainian cities. It is shown that the achievement of high energy efficiency is possible only with the introduction of automatic individual heating points with weather control and pressure drop regulators at the inlet to the buildings in the subscriber heating systems. Calculations of the amount of heat consumption reduction of centralized heat supply systems with the introduction of optimal control systems are performed.

scholarly journals Use of vertical geothermal heat exchanger with nanofluid for heat supply systems

2021 ◽  
Vol 288 ◽  
pp. 01089
Author(s):  
Alexei Sednin ◽  
Aliaksandr Mukhin ◽  
Boris Balakin
Keyword(s):  
Heat Exchanger ◽  
District Heating ◽  
Heat Pumps ◽  
Working Fluid ◽  
Geothermal Heat ◽  
Heating Systems ◽  
District Heating Systems ◽  
Geothermal Heat Exchanger ◽  
Double Pipe ◽  
Supply Systems

Future district heating systems need to be more flexible and move towards a carbon-neutral generation. Compression heat pumps are foreseen to be promising future tools for district heating systems in EU countries. The paper presents the simulation data or a vertical double-pipe geothermal heat exchanger with ethylene glycol-Al2O3 as a working fluid. To simulate the operation of the heat exchanger, the STAR-CCM + CFD application was used. It has been determined the optimal volume particle concentrations of nanofluid and enhance of heat exchanger performance.

Experimental Research of Thermo-Hydraulic Separators and Dispatchers in Heat Supply Systems

2018 ◽  
Vol 284 ◽  
pp. 1385-1389 ◽  
Author(s):  
Y.V. Yavorovsky ◽  
D.O. Romanov ◽  
V.G. Khromchenkov
Keyword(s):  
Low Temperature ◽  
Experimental Research ◽  
Heat Supply ◽  
District Heating ◽  
Ansys Fluent ◽  
Heating Systems ◽  
Experimental Part ◽  
District Heating Systems ◽  
Heat Supply Systems ◽  
Supply Systems

This article is concerned with the research of thermos-hydraulic separators and dispatchers (THD) in heat supply systems and focuses on the experimental part of the research. Тhe experiments allowed to develop the ANSYS Fluent model in terms of accuracy and veracity. The developed model allows to predict operation of THD in different regimes. The results may be used for designing the systems with THD. Such systems may be low temperature district heating systems, where THD allow to hydraulically separate the circuits from each other.

scholarly journals Design of direct acting differential pressure control valve test bench

2021 ◽  
Vol 327 ◽  
pp. 04002
Author(s):  
Ognyan Bekriev ◽  
Radoslav Asenov
Keyword(s):  
Test Bench ◽  
District Heating ◽  
Control Valve ◽  
Pressure Control ◽  
Differential Pressure ◽  
Heating Systems ◽  
Control Valves ◽  
District Heating Systems ◽  
Pressure Control Valve ◽  
Direct Acting

This article aims to acquaint readers with a designed test bench for direct acting differential pressure control valves. These control valves are used in district heating systems. The conformity of the construction of the test bench with the international standard IEC 60534-2-3:2015 is evaluate and the results of an experimental study of the control valve AVPB DN20 Kvs 6.3 PN16 are present.

Adapting the Existing District Heating Systems to Dynamic Operating Conditions

2015 ◽  
Vol 809-810 ◽  
pp. 688-693 ◽  
Author(s):  
Răzvan Corneliu Lefter ◽  
Daniela Popescu
Keyword(s):  
Energy Efficiency ◽  
District Heating ◽  
Point Of View ◽  
Operating Conditions ◽  
Flow Rates ◽  
Heating Systems ◽  
Operation Conditions ◽  
District Heating Systems ◽  
Dynamic Operating ◽  
Heating Networks

District heating systems operating under dynamic conditions without proper hydronic balancing is one of the causes of discomfort for heating consumers. Moreover, from the point of view of producers, unbalanced heating networks generate low energy efficiency. The study analyzes the operation conditions in three cases, on the same network: the first simulates the operating conditions of the network without balancing, the second when just balancing valves set to corresponding nominal flow rate values are used and the third when balancing valves and differential pressure controllers are used, the so-called total balancing method. Results highlight the importance of the hydraulic balancing under steady state and dynamic operating conditions, as a source to increase the energy efficiency and assure thermal comfort by better distribution of fluid flow rates between consumers.

scholarly journals Modernization for cogeneration and district heating systems in urban areas: objectives and practice

2018 ◽  
Vol 11 (3) ◽  
pp. 184-191
Author(s):  
V. I. Sharapov ◽  
M. E. Orlov ◽  
M. M. Zamaleev ◽  
P. E. Chaukin
Keyword(s):  
Urban Areas ◽  
Heat Supply ◽  
Power Plants ◽  
District Heating ◽  
Combined Heat And Power ◽  
Heat Sources ◽  
Heating Systems ◽  
District Heating Systems ◽  
Heat Supply Systems ◽  
Supply Systems

The factors determining the need for modernization of urban district heating systems with combined heat and power are considered. It is noted that these factors include a significant reduction in thermal loads, new technical and technological opportunities for improving district heating systems, the change in legislation in the field of energy and heat supplying. It is shown that the main disadvantage of the current state of Russian cogeneration systems is a decrease in the combined production of heat and power, leading to a decrease in the efficiency of fuel use, due to unreasonably extensive use of autonomous heat supply sources in many regions. Besides, combined heat and power plants (CHPP) experience a lack of a level playing field in competition with other power plants in the electricity market, with a technically and economically unjustified ban imposed on open heat supply systems. For effective use of the benefits of cogeneration and district heating, the following top priority measures are recommended. It is required to legislate the economic benefits for the combined production of electricity and heat. It is necessary to adjust the model of the wholesale electric energy and power market to eliminate discrimination of CHPP in this market. The construction of autonomous heat sources in urban areas with CHPPs is to be prohibited unless substantiated with an adequate feasibility study. Decommissioning of CHPPs and heat sources, which are used to back up CHPPs, must only be permitted subject to a mandatory feasibility study, including assessment of effects on reliability of heat supply of urban consumers. The Russian Federal Law “On heat supply” is to be adjusted to lift the total ban on the use of open heat supply systems. It is required to create a national body with sufficient authority to control and coordinate the activities of energy companies to modernize cogeneration and district heating systems.

scholarly journals Methodology for the Optimal Development of District Heating Systems: Theoretical and Practical Research

2020 ◽  
Vol 209 ◽  
pp. 02028
Author(s):  
Ivan Postnikov ◽  
Andrey Penkovskii ◽  
Ekaterina Mednikova
Keyword(s):  
Heat Supply ◽  
District Heating ◽  
Heating Systems ◽  
Fuel Supply ◽  
Market Participants ◽  
Irkutsk Region ◽  
District Heating Systems ◽  
Comprehensive Reliability ◽  
Supply Systems

The paper presents a synthesis of research results on the development of scientific and methodo-logical support for the comprehensive solution of the main technical, economic and organizational problems of designing, functioning and development of modern district heating systems (DHS). These studies were conducted at the Melentiev Energy Systems Institute of SB RAS (Irkutsk city) by the scientific team of the Laboratory of Heat Supply Systems. Within the framework of the developed scientific and methodological support, the following basic problems were solved: optimization of levels of district heating in DHS with feasibility study for connecting new consumers, selection of optimal forms and models of heating market for DHS, comprehensive analysis and ensuring (optimization) reliability of DHS taking into account the fuel supply of heating sources (HS), and other additional problems. Based on the developed scientific and methodological ensuring following practical researches were carried out on existing DHS schemes of cities of the Irkutsk region: optimal management of DHS in Angarsk, Irkutsk region, taking into account the diverging interests of heating market participants; determination of the optimal scale of development of the existing DHS in Irkutsk based on the optimization of the effective heat supply radius taking into account the reliability of heating to consumers; comprehensive reliability analysis of DHS in Shelekhov of Irkutsk region, taking into account the fuel supply to HS.

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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