Demonstration and optimization of a solar district heating system with ground source heat pumps

Solar Energy ◽  
2020 ◽  
Vol 202 ◽  
pp. 171-189 ◽  
Author(s):  
Junpeng Huang ◽  
Jianhua Fan ◽  
Simon Furbo
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.


2020 ◽  
Author(s):  
Eric Wagner ◽  
Benjamin McDaniel ◽  
Dragoljub Kosanovic

Ground-source heat pump (GSHP) systems have been implemented at large scales on several university campuses to provide heating and cooling. In this study, we test the idea that a GSHP system, as a replacement for an existing Combined Heat and Power (CHP) heating system coupled with conventional cooling systems, could reduce CO2 emissions, and provide a cost benefit to a university campus. We use the existing recorded annual heating and cooling loads supplied by the current system and an established technique of modeling the heat pumps and borehole heat exchangers (BHEs) using a TRNSYS model. The GSHP system is modeled to follow the parameters of industry standards and sized to provide an optimal balance of capital and operating costs. Results show that despite a decrease in heating and cooling energy usage and CO2 emissions are achieved, a significant increase in electric demand and purchased electricity result in an overall cost increase. These results highlight the need for thermal energy storage, onsite distributed energy resources and/or demand response in cases where electric heat pumps are used to help mitigate electric demand during peak periods.


2015 ◽  
Vol 121 ◽  
pp. 1406-1412 ◽  
Author(s):  
Zhigang Wang ◽  
Daxing Huang ◽  
Pan Wang ◽  
Qiang Shen ◽  
Qingnan Zhang ◽  
...  

Author(s):  
Gatis Bazbauers ◽  
Ginta Cimdina

The Role of the Latvian District Heating System in the Development of Sustainable Energy Supply The aim of the study is to determine whether and to what extent it is possible to use excess electricity produced by wind power plants during low demand periods for district heat production by heat pumps. Energy system analysis on an hourly basis is conducted at various capacities of wind power plants. The results show that it is possible to increase the share of renewable energy sources, decrease the use of primary energy sources and CO2 emissions per unit of the produced energy, i.e. heat and electricity, by using the surplus electricity produced by wind power in the heat pumps combined with the heat storage.


2021 ◽  
pp. 103438
Author(s):  
Francesco Calise ◽  
Francesco Liberato Cappiello ◽  
Massimo Dentice d'Accadia ◽  
Fontina Petrakopoulou ◽  
Maria Vicidomini

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Richard P van Leeuwen ◽  
Jirka Fink ◽  
Jan B de Wit ◽  
Gerard JM Smit

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 321 ◽  
Author(s):  
Francesco Neirotti ◽  
Michel Noussan ◽  
Stefano Riverso ◽  
Giorgio Manganini

District heating systems have an important role in increasing the efficiency of the heating and cooling sector, especially when coupled to combined heat and power plants. However, in the transition towards decarbonization, current systems show some challenges for the integration of Renewable Energy Sources and Waste Heat. In particular, a crucial aspect is represented by the operating temperatures of the network. This paper analyzes two different approaches for the decrease of operation temperatures of existing networks, which are often supplying old buildings with a low degree of insulation. A simulation model was applied to some case studies to evaluate how a low-temperature operation of an existing district heating system performs compared to the standard operation, by considering two different approaches: (1) a different control strategy involving nighttime operation to avoid the morning peak demand; and (2) the partial insulation of the buildings to decrease operation temperatures without the need of modifying the heating system of the users. Different temperatures were considered to evaluate a threshold based on the characteristics of the buildings supplied by the network. The results highlight an interesting potential for optimization of existing systems by tuning the control strategies and performing some energy efficiency operation. The network temperature can be decreased with a continuous operation of the system, or with energy efficiency intervention in buildings, and distributed heat pumps used as integration could provide significant advantages. Each solution has its own limitations and critical parameters, which are discussed in detail.


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