scholarly journals Reduction of return temperatures in urban district heating systems by the implementation of energy-cascades

2017 ◽  
Vol 116 ◽  
pp. 438-451 ◽  
Author(s):  
Markus Köfinger ◽  
Daniele Basciotti ◽  
Ralf-Roman Schmidt
Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1302 ◽  
Author(s):  
Leszek Pająk ◽  
Barbara Tomaszewska ◽  
Wiesław Bujakowski ◽  
Bogusław Bielec ◽  
Marta Dendys

The paper presents a review of the geological and hydrogeological data of the Lower Cretaceous aquifer in the Polish Lowlands and discusses the possibilities for the utilisation of geothermal water resources in existing and new district heating systems. Based on experience related to the use of thermal waters in existing geothermal systems, and using data from the literature, assessments have been made of the energy and environmental effects of the application of low-enthalpy geothermal resources from the Lower Cretaceous aquifer as a source of heat for urban district heating systems. The authors concluded that the implementation of such solutions could result in the production of approximately 4 PJ of geothermal energy annually. To date, these resources have only been developed in three locations—Mszczonów, Uniejów and Poddębice—with the total amount of energy generated annually reaching 100 TJ/year. Similar district heating networks in 120 nearby localities have been also identified. Here, specified geological and hydrogeological conditions enable the extraction of heat from the investigated Lower Cretaceous aquifer, with the aim of using this for heating purposes. To achieve this goal, multiple measures are required, including the following: raising public awareness through appropriate education programmes aimed at the youngest school children; systemic, efficient energy management measures at the central, regional and local levels, and providing financial support and ensuring regulations and laws aimed at improving the development of geothermal resources.


Author(s):  
Ye.Ye. Nikitin

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.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3218
Author(s):  
Pedro Durán ◽  
Herena Torio ◽  
Patrik Schönfeldt ◽  
Peter Klement ◽  
Benedikt Hanke ◽  
...  

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.


2021 ◽  
Vol 285 ◽  
pp. 116392
Author(s):  
Ruud Egging-Bratseth ◽  
Hanne Kauko ◽  
Brage Rugstad Knudsen ◽  
Sara Angell Bakke ◽  
Amina Ettayebi ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3169
Author(s):  
Sara Månsson ◽  
Marcus Thern ◽  
Per-Olof Johansson Kallioniemi ◽  
Kerstin Sernhed

Faults in district heating (DH) customer installations cause high return temperatures, which have a negative impact on both current and future district heating systems. Thus, there is a need to detect and correct these faults soon after they occur to minimize their impact on the system. This paper, therefore, suggests a fault handling process for the detection and elimination of faults in DH customer installations. The fault handling process is based on customer data analysis since many faults manifest in customer data. The fault handling process was based on an analysis of the results from the previous fault handling studies, as well as conducting a workshop with experts from the DH industry. During the workshop, different organizational and technical challenges related to fault handling were discussed. The results include a presentation of how the utilities are currently working with fault handling. The results also present an analysis of different organizational aspects that would have to be improved to succeed in fault handling. The paper also includes a suggestion for how a fault handling process based on fault detection using data analysis may be designed. This process may be implemented by utilities in both current and future DH systems that interested in working more actively with faults in their customer installations.


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