scholarly journals Evaluation of integration of solar energy into the district heating system of the city of Velika Gorica

2016 ◽  
Vol 20 (4) ◽  
pp. 1049-1060 ◽  
Author(s):  
Andreu Felipe ◽  
Daniel Schneider ◽  
Goran Krajacic

In the current situation the district heating system supplies the 32% of the total thermal consumption in the City of Velika Gorica. The main issue in the district heating system is the utilization of 14 small and distributed heat plants, each providing heat to a separate and individually disconnected heating grid. Reduction of costs and CO2 emissions can be reached with a high penetration of renewable sources. The aim of this paper is to evaluate and design the integration of a Central Solar Heating Plant with Seasonal Storage into the district heating system of the City. An economic assessment was made with a pessimistic and an optimistic prediction of the solar heat cost for ground mounted collectors and roof mounted collectors. The seasonal storage was chosen to be pit thermal energy storage; the system was modeled as a low-temperature district heating system with the real thermal demands of a district heating plant.

Energy ◽  
2020 ◽  
Vol 194 ◽  
pp. 116773 ◽  
Author(s):  
Helga Hubeck-Graudal ◽  
Jonas Kjeld Kirstein ◽  
Torben Ommen ◽  
Martin Rygaard ◽  
Brian Elmegaard

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.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2347
Author(s):  
Elżbieta Hałaj ◽  
Jarosław Kotyza ◽  
Marek Hajto ◽  
Grzegorz Pełka ◽  
Wojciech Luboń ◽  
...  

Krakow has an extensive district heating network, which is approximately 900 km long. It is the second largest city in terms of the number of inhabitants in Poland, resulting in a high demand for energy—for both heating and cooling. The district heating of the city is based on coal. The paper presents the conception of using the available renewable sources to integrate them into the city’s heating system, increasing the flexibility of the system and its decentralization. An innovative solution of the use of hybrid, modular heat pumps with power dependent on the needs of customers in a given location and combining them with geothermal waters and photovoltaics is presented. The potential of deep geothermal waters is based on two reservoirs built of carbonate rocks, namely Devonian and Upper Jurassic, which mainly consist of dolomite and limestone. The theoretical potential of water intake equal to the nominal heating capacity of a geothermal installation is estimated at 3.3 and 2.0 MW, respectively. Shallow geothermal energy potential varies within the city, reflecting the complex geological structure of the city. Apart from typical borehole heat exchangers (BHEs), the shallower water levels may represent a significant potential source for both heating and cooling by means of water heat pumps. For the heating network, it has been proposed to use modular heat pumps with hybrid sources, which will allow for the flexible development of the network in places previously unavailable or unprofitable. In the case of balancing production and demand, a photovoltaic installation can be an effective and sufficient source of electricity that will cover the annual electricity demand generated by the heat pump installation, when it is used for both heating and cooling. The alternating demand of facilities for heating and cooling energy, caused by changes in the seasons, suggests potential for using seasonal cold and heat storage.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3350
Author(s):  
Theofanis Benakopoulos ◽  
William Vergo ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Svend Svendsen

The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.


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.


Author(s):  
M Lemann

This paper outlines the system used by the authorities in Zurich to treat and recycle waste in an environmentally acceptable way. The waste incineration system produces power and incorporates a district heating system as well as a wet gas-cleaning process.


2019 ◽  
Vol 135 ◽  
pp. 01031
Author(s):  
Mereke Agilbayeva ◽  
Alexey Kalinin

The district heating system of Karaganda (Kazakhstan) is considered in the article. The characteristics of the existing cogenerators and the state of the pipeline networks are given. Given the analysis of the existing state of the entire district heating of Karaganda. Proposed the program for the integrated development of the heat supply system bringing world experience in implementing the main development and modernization of heating networks. Shown the experience of reconstruction of heat supply facilities in the city of Karaganda within the framework of the state loan program “Nurly Zhol”. Based on the statistical data on the development of the city of Karaganda and its heat supply system the predicted heat loads are given until 2030. Due to the shortage of available heat capacity, options for the development of a centralized heat supply system in Karaganda are given and analyzed.


Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4694
Author(s):  
Tina Lidberg ◽  
Thomas Olofsson ◽  
Louise Ödlund

When buildings become more energy effective, the temperature levels of district heating systems need to be lower to decrease the losses from the distribution system and to keep district heating a competitive alternative on the heating market. For this reason, buildings that are refurbished need to be adapted to suit low-temperature district heating. The aim of this paper is to examine whether four different energy refurbishment packages (ERPs) can be used for lowering the temperature need of a multi-family buildings space heating and domestic hot water (DHW) system as well as to analyse the impact of the DHW circulation system on the return temperature. The results show that for all ERPs examined in this study, the space heating supply temperature agreed well with the temperature levels of a low-temperature district heating system. The results show that the temperature need of the DHW system will determine the supply temperature of the district heating system. In addition, the amount of days with heating demand decreases for all ERPs, which further increases the influence of the DHW system on the district heating system. In conclusion, the DHW system needs to be improved to enable the temperature levels of a low-temperature district heating system.


Sign in / Sign up

Export Citation Format

Share Document