scholarly journals Design and Assessment of District Heating Systems with Solar Thermal Prosumers and Thermal Storage

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1184
Author(s):  
Danhong Wang ◽  
Jan Carmeliet ◽  
Kristina Orehounig
Keyword(s):  
District Heating ◽  
Thermal Storage ◽  
Solar Thermal ◽  
Demand Model ◽  
District Size ◽  
Modeling Framework ◽  
District Heating System ◽  
Heating Systems ◽  
District Heating Systems

In this study, a holistic energy, economic and environmental assessment was performed on a prosumer-based district heating system, including scenarios with varying district size, retrofitting stages and system configurations. A modeling framework was built which comprises a thermal network design and simulation model; a building energy demand model for districts; and supply and storage technology models that allow assessing system solar fraction, equivalent annual cost and greenhouse gas emissions of district heating systems (DHS). Furthermore, the approach allows comparing the performance of a DHS with individual heating systems (IHS) for the district with the same set of technology options (rooftop-mounted solar thermal collectors, gas boilers and thermal storage tanks). The framework was applied to a Swiss case study. The results of the case study show that DHS often outperform IHS; however, parameters such as the district size, the retrofitting stage of buildings and the system configuration have impacts on the performance of the DHS. The most important parameter lies in the adequate selection of the storage volume over solar collector area ratio, which indicates that DHS solutions are only advantageous if they are properly sized. Smaller districts and districts with retrofitted buildings especially benefit from DHS solutions in terms of energy, economic and environmental performance. Maximum solar fractions of 50% (non-retrofitted case) and 63% (retrofitted case) were reached with the DHS solutions.

scholarly journals Excess heat utilization combined with thermal storage integration in district heating systems using renewables

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3673-3684
Author(s):  
Borna Doracic ◽  
Marino Grozdek ◽  
Tomislav Puksec ◽  
Neven Duic
Keyword(s):  
Service Sector ◽  
Peak Load ◽  
District Heating ◽  
Thermal Storage ◽  
Heating System ◽  
District Heating System ◽  
Heating Systems ◽  
Excess Heat ◽  
Heat Demand ◽  
District Heating Systems

District heating systems already play an important role in increasing the sustainability of the heating sector and decreasing its environmental impact. However, a high share of these systems is old and inefficient and therefore needs to change towards the 4th generation district heating, which will incorporate various energy sources, including renewables and excess heat of different origins. Especially excess heat from industrial and service sector facilities is an interesting source since its potential has already been proven to be highly significant, with some researches showing that it could cover the heat demand of the entire residential and service sector in Europe. However, most analyses of its utilisation in district heating are not done on the hourly level, therefore not taking into account the variability of its availability. For that reason, the main goal of this work was to analyse the integration of industrial excess heat into the district heating system consisting of different configurations, including the zero fuel cost technologies like solar thermal. Furthermore, cogeneration units were a part of every simulated configuration, providing the link to the power sector. Excess heat was shown to decrease the operation of peak load boiler and cogeneration, that way decreasing the costs and environmental effect of the system. However, since its hourly availability differs from the heat demand, thermal storage needs to be implemented in order to increase the utilisation of this source. The analysis was performed on the hourly level in the energyPRO software

scholarly journals Techno-economic analysis of implementing thermal storage for peak load shaving in a campus district heating system with waste heat from the data centre

2021 ◽  
Vol 246 ◽  
pp. 09003
Author(s):  
Haoran Li ◽  
Juan Hou ◽  
Yuemin Ding ◽  
Natasa Nord
Keyword(s):  
Waste Heat ◽  
Peak Load ◽  
District Heating ◽  
Thermal Storage ◽  
Heating System ◽  
Water Tank ◽  
District Heating System ◽  
Heating Systems ◽  
Heat Demand ◽  
District Heating Systems

Peak load has significant impacts on the economic and environmental performance of district heating systems. Future sustainable district heating systems will integrate thermal storages and renewables to shave their peak heat demand from traditional heat sources. This article analysed the techno-economic potential of implementing thermal storage for peak load shaving, especially for the district heating systems with waste heat recovery. A campus district heating system in Norway was chosen as the case study. The system takes advantage of the waste heat from the campus data centre. Currently, about 20% of the heating bill is paid for the peak load, and a mismatch between the available waste heat and heat demand was detected. The results showed that introducing water tank thermal storage brought significant effects on peak load shaving and waste heat recovery. Those effects saved up to 112 000 EUR heating bills annually, and the heating bill paid for the peak load could be reduced by 15%. Meanwhile, with the optimal sizing and operation, the payback period of the water tank could be decreased to 13 years. Findings from this study might help the heat users to evaluate the economic feasibility of introducing thermal storage.

scholarly journals Optimal coefficient of the share of cogeneration in the district heating system cooperating with thermal storage

2011 ◽  
Vol 32 (3) ◽  
pp. 71-87 ◽  
Author(s):  
Andrzej Ziębik ◽  
Paweł Gładysz
Keyword(s):  
High Efficiency ◽  
District Heating ◽  
Thermal Storage ◽  
Heating System ◽  
District Heating System ◽  
Heating Systems ◽  
Optimal Value ◽  
District Heating Systems ◽  
Optimal Coefficient ◽  
The Cost

Optimal coefficient of the share of cogeneration in the district heating system cooperating with thermal storage The paper presents the results of optimizing the coefficient of the share of cogeneration expressed by an empirical formula dedicated to designers, which will allow to determine the optimal value of the share of cogeneration in contemporary cogeneration systems with the thermal storages feeding the district heating systems. This formula bases on the algorithm of the choice of the optimal coefficient of the share of cogeneration in district heating systems with the thermal storage, taking into account additional benefits concerning the promotion of high-efficiency cogeneration and the decrease of the cost of CO2 emission thanks to cogeneration. The approach presented in this paper may be applicable both in combined heat and power (CHP) plants with back-pressure turbines and extraction-condensing turbines.

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.

Method for Redesign of District Heating Networks within Transition from the 2nd to the 3rd Generation

2014 ◽  
Vol 657 ◽  
pp. 689-693
Author(s):  
Răzvan Corneliu Lefter ◽  
Daniela Popescu ◽  
Alexandrina Untăroiu
Keyword(s):  
District Heating ◽  
Design Stage ◽  
Heating Systems ◽  
Load Duration ◽  
Load Duration Curve ◽  
District Heating Systems ◽  
Consumption Rates ◽  
Heat Loads ◽  
Heating Networks

Important investmentsare made lately in the area of district heating, as a technology capable ofhelping countries to reach sustainability goals. In Romania, European fundswere spent for transition from the 2nd to the 3rdgeneration of district heating systems. The lack of appropriate monitoringsystems in old district heating systems makes optimisation nowadays very difficult,especially because nominal values used in the first design stage areoverestimated. Realistic nominal heat loads are necessary to make goodestimations of hydraulic parameters to be used for redesign. This studyproposes a method that uses the heat load duration curve theory to identify theappropriate nominal heat loads to be used for redesign. Comparison betweenresults obtained by applying the nominal heat loads of each consumer, as theywere established in the first design stage, and the ones identified by theproposed method are analyzed in a case study. The results show that errors arein the +/- 3% band, between the metered heat consumption rates and the proposedrates. The new method can be used for the sizing of pumps and district heatingnetworks after retrofit, in order to get better adjustments of the circulationpumps and increase of the energy efficiency.

Heat Accumulator in Large District Heating Systems: Simulation and Optimisation

2010 ◽  
Author(s):  
Krzysztof Badyda ◽  
Wojciech Bujalski ◽  
Jarosław Milewski ◽  
Michał Warchoł
Keyword(s):  
Heat Production ◽  
District Heating ◽  
Heating System ◽  
Heat Accumulator ◽  
District Heating System ◽  
Heating Systems ◽  
District Heating Systems ◽  
On Line ◽  
Systems Simulation

Heat accumulators in large district heating systems are used to buffer heat production. Their main purpose is to make heat production as independent as possible from district heating system demand. To do this effectively a heat accumulator of appropriate capacity must be selected. In large district heating systems, heat accumulators can be used for equalising production over periods lasting a few hours. Accumulators can be used for optimising electricity and heat production to achieve possible highest income. It may be important in situations where on-line prices change. An optimising algorithm for heat accumulator use is shown and commented. Typical working situations are simulated and results presented.

scholarly journals Integration of solar thermal systems into existing district heating systems

2017 ◽  
Vol 116 ◽  
pp. 158-169 ◽  
Author(s):  
C. Winterscheid ◽  
S. Holler ◽  
J.-O. Dalenbäck
Keyword(s):  
District Heating ◽  
Solar Thermal ◽  
Thermal Systems ◽  
Heating Systems ◽  
District Heating Systems

scholarly journals Hourly optimization and sizing of district heating systems considering building refurbishment – Case study for the city of Zagreb

Energy ◽  
2017 ◽  
Vol 137 ◽  
pp. 1264-1276 ◽  
Author(s):  
Matija Pavičević ◽  
Tomislav Novosel ◽  
Tomislav Pukšec ◽  
Neven Duić
Keyword(s):  
District Heating ◽  
Heating Systems ◽  
District Heating Systems ◽  
Building Refurbishment ◽  
The City
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