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.

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 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 Business and socioeconomic assessment of introducing heat pumps with heat storage in small-scale district heating systems

2019 ◽  
Vol 139 ◽  
pp. 904-914 ◽  
Author(s):  
Poul Alberg Østergaard ◽  
Jan Jantzen ◽  
Hannah Mareike Marczinkowski ◽  
Michael Kristensen
Keyword(s):  
Heat Storage ◽  
District Heating ◽  
Heat Pumps ◽  
Small Scale ◽  
Heating Systems ◽  
District Heating Systems

scholarly journals Comparison of 4th and 5th generation district heating systems

2021 ◽  
Vol 246 ◽  
pp. 09004
Author(s):  
Oddgeir Gudmundsson ◽  
Anders Dyrelund ◽  
Jan Eric Thorsen
Keyword(s):  
District Heating ◽  
Heating System ◽  
Heat Pumps ◽  
District Heating System ◽  
Heating Systems ◽  
District Energy ◽  
District Heating Systems ◽  
Operating Temperatures ◽  
New Research ◽  
Levelized Cost Of Heat

In a pursuit to increase the efficiency of district heating system there has been a continuous focus to reduce the system operating temperatures. This has led to the current state of the art district heating systems, commonly referred to as the 4th generation district heating, also known as low temperature district heating (LTDH). The success of the LTDH has fuelled a lot of research interest in district energy systems, one of the new research topics has been focusing on reducing the operating temperatures down to the ambient temperature (ATDH), commonly referred as 5th generation district heating. In these systems the supply temperature is insufficient for fulfilling the heating demands of the connected buildings, which then requires end-user located heat pumps to raise the supply temperature to the level required by the buildings. As of today, number of ATDH systems have been realized as part of various research projects. The question however remains if ATDH brings additional benefits compared to LTDH. This paper compares the levelized cost of heat from these two systems types for two countries with different climate zones. The results of the analysis indicate that LTDH is the favourable solution in both countries.

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