scholarly journals Complete Analysis of the Impact of Distributed Heat Accumulators on the Efficiency of the District Heating Networks

2017 ◽  
Vol 14 (03) ◽  
pp. 34-39
Author(s):  
Malgorzata Kwestarz
Author(s):  
Daniel P. Smith

Abstract This article attempts to identify the main ‘above-ground’ factors which impact on the contribution that geothermal energy can make to the Dutch Energy Transition, and to draw conclusions about these factors. Recent literature sources are used to illustrate the size of Dutch heating demand, and the part of this which can be provided by geothermal energy. Consideration is given to the impact of off-take variability over time, showing that the base-load nature of geothermal doublets acts as a restraint on the share which they can take in the energy supply. The characteristics of district heating grids are discussed. Other potential sources of heat are considered and compared. The conclusion is that geothermal energy can provide a material contribution to the energy transition. This depends to a large extent on the existence of and design choices made for the development of district heating networks. Large size and standardisation, and the development of seasonal heat storage, are beneficial. Unlike most other renewable sources of heat, which have alternative ‘premium’ applications such as the provision of ‘peak capacity’ or molecules for feedstock, geothermal energy is not suitable for other uses. The emission savings that it can provide will be lost if other heat sources are chosen in preference as supply for district heating, so that it makes sense that district heating infrastructure should be designed to encourage the use of geothermal energy where possible.


2020 ◽  
Vol 176 ◽  
pp. 115413 ◽  
Author(s):  
Mohammad Amin Mirzaei ◽  
Morteza Nazari-Heris ◽  
Kazem Zare ◽  
Behnam Mohammadi-Ivatloo ◽  
Mousa Marzband ◽  
...  

2021 ◽  
Vol 25 (1) ◽  
pp. 786-802
Author(s):  
Kertu Lepiksaar ◽  
Kiur Kalme ◽  
Andres Siirde ◽  
Anna Volkova

Abstract District heating has proven to be an efficient way of providing space heating and domestic hot water in populated areas. It has also proven to be an excellent way to integrate various renewable energy sources (RES) into the energy system. In Estonia, biomass covers most of the heat demand, but carbon-intensive fuels are still used to cover peaks and lows. Heat pumps can be a good solution for rural areas, as there is usually plenty of land available for heat pump facilities. In addition, heat pumps require low-grade heat sources such as ambient air, groundwater, lakes, rivers, sea, sewage water, and industrial waste heat. One of the downsides of heat pumps is the need for large investments compared to boilers fired by natural gas and biomass, and electric boilers. This study examines the impact of heat pump use on consumer prices for district heating in rural district heating networks in Estonia.


2021 ◽  
Vol 2042 (1) ◽  
pp. 012089
Author(s):  
Clement Dromart ◽  
Loïc Puthod ◽  
Jérôme H. Kämpf ◽  
Diane von Gunten

Abstract A key advantage of district heating networks is their ability to integrate different renewable energy sources, from geothermal to solar. However, the success of this integration depends on a variety of design and technical decisions, such as feed-in locations or operating temperatures, which need to be compared and analysed. For this purpose, dynamic models of district heating grids, which allow for an hourly representation of the thermodynamic conditions, are necessary. This type of models are nevertheless still uncommon, drastically limiting options to perform these comparisons accurately. To address this challenge, an open-source tool to model district heating networks is presented here and successfully applied to two case studies in western Switzerland. These simulations are then used in conjunction with simplified models of storage and solar thermal collectors to investigate, in a preliminary way, the impact of solar thermal integration on the mass flow and temperature of the network pipes, illustrating the interest of the proposed method to compare different configurations of renewable heat injections in district heating networks.


Author(s):  
Lina Aglén

The introduction of district heating will have a significant impact on the building services industry, from the architecture of a building to its operation. This technical note investigates a delimited portion of the potential of currently unutilised heat which has the possibility to supply district heating networks in the UK. The UK industrial sector, wastewater treatment facilities and the existing UK waste incineration plants all produce waste heat available in a temperature range suitable for extraction into district heating networks via commercialised techniques broadly used in other countries. This technical note presents a comparative literature review, comparing UK statistics and studies with performance data based on Swedish operational facilities. It finds 51.7TWh of currently unutilised heat could be recovered annually, with a significant associated emission decrease if incorporated into the heat supply of the UK building stock. A quantitative analysis is carried out to compare the identified potential with the current UK heat demand and the potential impact on the UK carbon emissions is estimated. The calculations indicate a reduction of 14% in the required UK total domestic heat supply, despite only including a limited fraction of the available waste heat potential. This technical note serves to highlight and emphasise the large amount of available waste heat potential currently not utilised in the UK. By estimating the impact of waste heat utilisation and incorporation into district heating and heat networks in the UK, the technical note aims to fuel discussion around the further incorporation of waste heat to be utilised in the UK heat sector.


Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 454.1-454
Author(s):  
N. Schlesinger ◽  
A. Yeo ◽  
P. Lipsky

Background:Hyperuricemia is associated with non-alcoholic fatty liver disease (NAFLD)1,2, but the relationship to fibrosis remains uncertain3. Moreover, it is not known whether lowering serum urate will affect the course of NAFLD. The availability of data from two randomized trials of pegloticase, a pegylated recombinant mammalian uricase, that profoundly decreases serum urate afforded the opportunity to test the hypothesis that lowering urate might improve NAFLD.Objectives:To determine whether treatment of chronic refractory gout patients with pegloticase was associated with improvement in NAFLD determined by Fibrosis 4 index (Fib4).Methods:Databases from patients with chronic refractory gout who participated in two randomized 6 month clinical trials (RCTs) of pegloticase were analyzed4. Sub-sets who had persistent urate lowering to levels <1 mg/dL in response to biweekly pegloticase (Responders, n=36) were compared to those who received placebo (n=43). Since liver biopsy information was not available on these subjects, we relied on Fib4, a validated non-invasive estimate of liver fibrosis in a variety of liver diseases5,6calculated from measurements of AST, ALT, platelet count and age (Age x AST/platelets x √ALT). A Fib4 value of 1.3 is an indication that further evaluation of liver disease is warranted.Results:At baseline, the mean Fib4 values were 1.40 ± 0.86 in pegloticase responders and 1.04 ± 0.53 in subjects receiving placebo. As shown in figure 1, subjects receiving placebo exhibited a change of 0.26 ± 0.41 in the Fib4 score over the six months of the RCTs compared with 0.13 ± 0.62 in the pegloticase responders (p=0.048; by linear regression). When only the subjects with a Fib4 value > 1.3 were considered, a significant difference in the change in the Fib4 values over the 6 months of the trial between pegloticase responders and those receiving placebo was also observed (-0.15 ± 0.67 vs 0.37 ± 0.42, p=0.004, by linear regression). The correlations between serum urate area under the curve (AUC) over the 6 months of the trial and the change in Fib4 value was rs=0.33, p=0.0.0004 (Spearman rank-order correlation coefficient). Finally, multiple linear regression analysis indicated serum urate AUC (as a surrogate measure for group) is the main contributor to the change in Fib4 (p=0.018 by linear regression).Conclusion:The data are consistent with the conclusion that persistent lowering of serum urate had a significant impact on Fib4 levels, implying a possible effect on the course of NAFLD. The results support a more complete analysis involving biopsy examination of the impact of urate on liver inflammation and fibrosis.References:[1]Yang C et al. PlosOne2017; 12:e0177249[2]Jaruvongvanich V et al. Eur J Gastroenterol Hepatol 2017; 29:1031[3]Jaruvongvanich V et al. Eur J Gastroenterol Hepatol 2017; 29:694[4]Sundy JS, et al. JAMA. 2011; 306 (7):711-20[5]Sterling RK et al. Hepatol 2006; 43:1317[6]Shah AG et al. Clin Gastroenterol Hepatol 2009;7:1104Disclosure of Interests: :Naomi Schlesinger Grant/research support from: Pfizer, Amgen, Consultant of: Novartis, Horizon Therapeutics, Selecta Biosciences, Olatec, IFM Therapeutics, Mallinckrodt Pharmaceuticals, Anthony Yeo Employee of: Horizon Therapeutics, Peter Lipsky Consultant of: Horizon Therapeutics


2021 ◽  
Vol 282 ◽  
pp. 116105
Author(s):  
Suhan Zhang ◽  
Wei Gu ◽  
Haifeng Qiu ◽  
Shuai Yao ◽  
Guangsheng Pan ◽  
...  

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