scholarly journals Determining the possibility of placing turbine systems for hydraulic regulation and production of electrical energy in the District Heating Network in Krakow

2021 ◽  
Vol 323 ◽  
pp. 00026
Author(s):  
Piotr Natkaniec ◽  
Piotr Dzierwa

This article presents the methods of specifying the potentiality of energy recovery in the turbine installations projected to hydraulic regulation of the heating medium in the Krakow District Heating System. To achieve this, creating hydraulic calculations enabling to indicate the best places to install turbines in District Heating System is necessary. For this reason, a great amount of work - like choosing a methodology and optimal calculation program, creating an actual database for calculations - has to be done. Hydraulic calculations will also help to determine optimal parameters of future instalments, select the most suitable devices necessary for the proper working of turbine installations and create the future impact assessment to District Heating System.

2007 ◽  
Vol 11 (3) ◽  
pp. 85-100
Author(s):  
Alija Lekic ◽  
Semsudin Hadziefendic

The main sources for power generation in Bosnia and Herzegovina are domestic coals, mainly lignite and brown coals, which are relatively characterized with a high content of sulphur (3-5%) and incombustibles (?30%). From the 70?s, use of this type of fuels was not allowed in the city of Sarajevo due to very unfavorable emissions to the atmosphere, during the heating period, and since then Sarajevo has been supplied with natural gas. All the heating installations in the city were reconstructed and adapted. The district heating system Toplane Sarajevo is supplied with electrical energy from the Public electrical distribution network (Elektrodistribucija Sarajevo) at low voltage (0.4 kV). The boiler-house Dobrinja III-2 (KDIII-2), from the district heating system of Sarajevo Suburb Dobrinja, which was not in use after the war 1992-1995, had a lot of advantages for the reconstruction into the co-generation plant. The Government of Canton Sarajevo financially supported this proposal. An analysis of co-generations for the district heating system and a selection of most appropriate co-generation systems were made. In the proposed conceptual design, the co-generation KDIII-2 was located in the existing boiler-house KDIII-2, connected with the heating system in Dobrinja. The operating costs of production of electricity and heat were evaluated in the study and compared with the costs of conventional energy supply to the district heating system. This analysis resulted in economic indicators, which showed that this investment was economically viable, and it also determined the payback period of the investment. In this paper results of the mentioned study and an overview of co-generation in Bosnia and Herzegovina are presented.


Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 368 ◽  
Author(s):  
Sung-Soo Jeon ◽  
Young Jae Lee ◽  
Yeongsu Bak ◽  
Kyo-Beum Lee

This paper presents not only a hardware-simulator development for hydraulic turbine generation systems (HTGS) in a district heating system (DHS) but also its control strategies and sequence. Generally, a DHS uses a differential pressure control valve (DPCV) to supply high-pressure–high-temperature fluids for customers depending on distance. However, long-term exposure of the DPCV to fluids increases the probability of cavitation and leads to heat loss in an event of cavitation. Therefore, a HTGS was introduced to solve this problem. It performs differential pressure control of the fluids, replaces the DPCV, and converts excess energy wasted by the DPCV to electrical energy. In this paper, the development of a hardware-simulator for HTGSs with a back-to-back converter, which uses two-level topologies, is proposed; moreover, control strategies and sequence used in this design are presented. The performance and validity of the proposed hardware-simulator and its control strategies are demonstrated by experimental results.


2019 ◽  
Vol 111 ◽  
pp. 05022
Author(s):  
Haoran Li ◽  
Natasa Nord

Low temperature is the most significant feature of the future district heating (DH) - the 4th generation district heating (4GDH). The revolutionary temperature level (50–55/25°C) will improve the efficiency of heat sources, thermal storages, and distribution systems, meanwhile, bring huge potentials to renewable energies. One challenge of transition to the future DH is the compatibility of current customer installations and the future temperature level. The aim of this study was to find the temperature potential of Norwegian residential buildings for the future DH system. A reference apartment was created, and typical space heating (SH) system was designed. A detailed building and SH system model were built in Modelica® language, and simulation was conducted via Dymola environment. Different operation strategies: PI control of the supply temperature, weather compensated control of the supply temperature, and PI control of the return temperature were tested. The results of the study showed the average supply temperature could be as low as 56~58°C, and only limited time the temperature was above 60 °C, when the controlled supply temperature strategies were applied. For the case with controlled return temperature strategies, the average return temperature were 30 and 37°C, while the average required supply temperature could be 72 and 94°C. The conclusion was that the low supply temperature could be achieved through optimized operation strategies. Whereas, the low return temperature was not able to be achieved only by improving the operation strategy.


2010 ◽  
Vol 14 (suppl.) ◽  
pp. 41-51 ◽  
Author(s):  
Mladen Stojiljkovic ◽  
Mirko Stojiljkovic ◽  
Bratislav Blagojevic ◽  
Goran Vuckovic ◽  
Marko Ignjatovic

Implementation of co-generation of thermal and electrical energy in district heating systems often results with higher overall energy efficiency of the systems, primary energy savings and environmental benefits. Financial results depend on number of parameters, some of which are very difficult to predict. After introduction of feed-in tariffs for generation of electrical energy in Serbia, better conditions for implementation of co-generation are created, although in district heating systems barriers are still present. In this paper, possibilities and effects of implementation of natural gas fired cogeneration engines are examined and presented for the boiler house that is a part of the district heating system owned and operated by the Faculty of Mechanical Engineering in Nis. At the moment, in this boiler house only thermal energy is produced. The boilers are natural gas fired and often operate in low part load regimes. The plant is working only during the heating season. For estimation of effects of implementation of co-generation, referent values are taken from literature or are based on the results of measurements performed on site. Results are presented in the form of primary energy savings and greenhouse gasses emission reduction potentials. Financial aspects are also considered and triangle of costs is shown.


2013 ◽  
Vol 64 ◽  
pp. 200-212 ◽  
Author(s):  
Wang Haichao ◽  
Jiao Wenling ◽  
Risto Lahdelma ◽  
Zou Pinghua ◽  
Zhan Shuhui

Water ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 787
Author(s):  
Dariusz Borkowski ◽  
Tomasz Węgiel

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.


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