Impact of district heating and groundwater heat pump systems on the primary energy needs in urban areas

The heating source of a district heating (DH) system in Beijing was reformed from coal boilers to a groundwater heat pump (GWHP) system and a sewage source heat pump (SSHP) system. This study aims to evaluate the actual performance and benefits of two water-source heat pump systems. We found total energy savings and primary energy saving rate due to the retrofit to be 950 tons of standard coal equivalent (TCE) every year and 34.6%, respectively. Field test results indicated the necessity of system performance improvement. Appropriate approaches to improve the system performance were discussed.

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Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽

10.3390/en13040954 ◽

2020 ◽

Vol 13 (4) ◽

pp. 954 ◽

Cited By ~ 1

Author(s):

Hanne Kauko ◽

Daniel Rohde ◽

Armin Hafner

Keyword(s):

Low Temperature ◽

Heat Pump ◽

Urban Areas ◽

Waste Heat ◽

Local Heating ◽

District Heating ◽

Heat Pumps ◽

Hot Water ◽

Local Network ◽

Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

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APLICATION OF REGRESSION ANALYSIS IN FEASIBILITY STUDIES OF CONSUMER CONNECTION TO DISTRICT HEATING SYSTEMS

Journal of Engineering Science ◽

10.52326/jes.utm.2021.28(4).12 ◽

2021 ◽

Vol XXVIII (4) ◽

pp. 121-132

Author(s):

Corina Chelmenciuc ◽

◽

Constantin Borosan ◽

Vadim Lisnic ◽

◽

...

Keyword(s):

Regression Analysis ◽

Urban Areas ◽

District Heating ◽

Feasibility Studies ◽

Heating System ◽

Primary Energy ◽

Energy Resources ◽

District Heating System ◽

Heating Systems ◽

District Heating Systems

Nowadays, both globally and in Europe, and nationally, there is a tendency to promote district heating systems to the detriment of individual ones to heat dwellings in urban areas. The need to develop the DHSs is indisputable considering the topicality of global warming, the depletion of the primary energy resources and the energy efficiency trend. This article presents the method of applying regression analysis in feasibility studies for the projects of new heat consumers connection to the district heating system (hereinafter – DHS) or previously disconnected consumers reconnection via individual heating points (hereinafter – IHP) when the necessary investments are to be borne by the DHS operator, and the thermal energy is produced in cogeneration. At the same time, it is demonstrated that there is a direct and linear correlation between fuel consumption and electricity and heat produced in cogeneration at CHP plant.

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Combined heat pump-district heating network energy source

E3S Web of Conferences ◽

10.1051/e3sconf/20184900063 ◽

2018 ◽

Vol 49 ◽

pp. 00063

Author(s):

Karolina Kurtz-Orecka ◽

Wojciech Tuchowski

Keyword(s):

Energy Efficiency ◽

Heat Source ◽

Heat Pump ◽

District Heating ◽

Heat Sources ◽

Medium Temperature ◽

Efficient Operation ◽

Energy Needs ◽

Working Medium ◽

Lower Heat

The article describes the innovative combination of the heat pump's operation with the heating network called as cHPNes. The heat pump's lower heat sources used so far are air, water or ground. Their efficiency is usually incoherent with the energy needs of recipients. In the period of the lowest temperatures of the source, we have the highest demand for heat in the supplied facility. A combination of the water heat pump and the heating network is aimed at increasing the energy efficiency (COP) of the heat source and indirectly increasing the participation of renewable energy in the energy balance of buildings. The essence of the new solution is the use of returning water in the heating network to supply the heat pump evaporator. The working medium temperature of the heating network on the return in the all-year cycle is stable and high, which allows further use of energy of the heating water on the return. These are the two main advantages of network water used as the lower heat source, allowing for stable and efficient operation of the heat pump with COP above 13. This solution is a response to the need to improve the energy efficiency of highly urbanized spaces.

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Renewable Energy Generation Scenarios Using 3D Urban Modeling Tools—Methodology for Heat Pump and Co-Generation Systems with Case Study Application †

Energies ◽

10.3390/en12030403 ◽

2019 ◽

Vol 12 (3) ◽

pp. 403 ◽

Cited By ~ 7

Author(s):

Verena Weiler ◽

Jonas Stave ◽

Ursula Eicker

Keyword(s):

Heat Pump ◽

Distribution System ◽

District Heating ◽

Energy Generation ◽

Primary Energy ◽

Modeling Tools ◽

District Heating System ◽

Heat Demand ◽

Chp System

In the paper, a method was developed to automatically dimensionalize and calculate central energy generation and supply scenarios with a district heating system for cities based on 3D building models in the CityGML format and their simulated heat demand. In addition, the roof geometry of every individual building is used to model photovoltaic energy generation potential. Two types of supply systems, namely a central heat pump (HP) system and a large co-generation (combined heat and power-CHP) system (both with a central storage and district distribution system), are modeled to supply the heat demand of the area under investigation. Both energy generation models are applied to a case study town of 1610 buildings. For the HP scenario, it can be shown that the case study town’s heat demand can be covered by a monovalent, low-temperature system with storage, but that the PV only contributes 15% to the HP electricity requirement. For the CHP scenario, only 61% of the heat demand can be covered by the CHP, as it was designed for a minimum of 4000 operating hours. Both the PV and the CHP excess electricity are fully injected into the grid. As a result, the primary energy comparison of both systems strongly depends on the chosen primary energy factors (PEF): with given German regulations the CHP system performs better than the HP system, as the grid-injected electricity has a PEF of 2.8. In the future, with increasingly lower PEFs for electricity, the situation reverses, and HPs perform better, especially if the CHP continues to use natural gas. Even when renewable gas from a power to gas (P2G) process is used for the CHP, the primary energy balance of the HP system is better, because of high conversion losses in the P2G process.

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Pumping Cost Minimization in an Existing District Heating Network

Volume 6A: Energy ◽

10.1115/imece2013-65169 ◽

2013 ◽

Cited By ~ 3

Author(s):

Adriano Sciacovelli ◽

Elisa Guelpa ◽

Vittorio Verda

Keyword(s):

Control Strategy ◽

Urban Areas ◽

Cost Minimization ◽

Fluid Dynamic ◽

District Heating ◽

Primary Energy ◽

Operating Conditions ◽

Waste To Energy ◽

District Heating System ◽

Partial Load

District heating is expected to significantly contribute to the reduction of primary energy needs for heating in urban areas. This result is obtained through use of such as CHP systems, residual heat from industries or waste-to-energy plants, as well as the integration of renewable energies. The pumping system plays a crucial role and may significantly affect its performances. In this paper a large district heating system is considered. Various operating conditions corresponding with partial load operation are analyzed through a thermo-fluid dynamic model of the network. For each condition, the optimal set point of the various pumps is obtained. The set of optimal operating conditions is finally used to obtain a control strategy for the network. Results show that with respect to conventional control strategy significant reductions in primary energy consumption can be achieved.

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Energy and environmental analysis of an open-loop ground-water heat pump system in an urban area

Thermal Science ◽

10.2298/tsci1003693b ◽

2010 ◽

Vol 14 (3) ◽

pp. 693-706 ◽

Cited By ~ 11

Author(s):

Giorgia Baccino ◽

Russo Lo ◽

Glenda Taddia ◽

Vittorio Verda

Keyword(s):

Ground Water ◽

Heat Pump ◽

Water Discharge ◽

Primary Energy ◽

Open Loop ◽

Hot Water ◽

Environmental Benefits ◽

Thermal Plume ◽

Pump System ◽

Groundwater Heat Pump

In this paper a multidisciplinary methodology for analyzing the opportunities for exploitation of open-loop groundwater heat pump is proposed. The approach starts from a model for calculation of a time profile of thermal requirements (heat and domestic hot water). This curve is then coupled with a model of the control system in order to determine the heat pump operation, which includes its energy performances (primary energy consumption) as well as profiles of water discharge to the aquifer in terms of mass flow rate and temperature. Then the thermo-fluid dynamics of the aquifer is performed in order to determine the system impact on the environment as on possible other systems. The application to a case study in the Piedmont region, in Italy, is proposed. Energy analysis of the system shows that ground-water heat pumps constitute an interesting option in areas with small housing density, where there is not district heating. In comparison with typical heating/cooling systems, environmental benefits are related with reduction in global emissions. These benefits may be significantly enhanced using renewables as the primary energy source to produce electricity. The analysis also shows that possible issues related with the extension of the subsurface thermal plume may arise in the case of massive utilization of this technology.

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Different design scenarios related to an open loop groundwater heat pump in a large building: Impact on subsurface and primary energy consumption

Energy and Buildings ◽

10.1016/j.enbuild.2010.09.026 ◽

2011 ◽

Vol 43 (2-3) ◽

pp. 347-357 ◽

Cited By ~ 26

Author(s):

Stefano Lo Russo ◽

Glenda Taddia ◽

Giorgia Baccino ◽

Vittorio Verda

Keyword(s):

Energy Consumption ◽

Heat Pump ◽

Primary Energy ◽

Open Loop ◽

Primary Energy Consumption ◽

Groundwater Heat Pump ◽

Large Building

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Techno-economic and environmental performances of heating systems for single-family code-compliant and passive houses

E3S Web of Conferences ◽

10.1051/e3sconf/201911103039 ◽

2019 ◽

Vol 111 ◽

pp. 03039 ◽

Cited By ~ 2

Author(s):

Ambrose Dodoo

Keyword(s):

Power Plant ◽

Heat Pump ◽

Power Plants ◽

Energy Use ◽

District Heating ◽

Primary Energy ◽

Climate Impacts ◽

Single Family ◽

Final Energy ◽

Energy Chain

In this study the implications of different energy efficiency requirements and heating solutions for versions of a single-family house in southern Sweden is explored. Final energy use, primary energy use, climate impacts and lifecycle cost of heat supply are analyzed for the building versions designed to meet the current Swedish BBR 2015 building code and heated with district heating or exhaust air heat pump. A case where the building is designed to the Swedish passive house criteria and heated with exhaust air heat pump is also analyzed. The district heating is assumed to be supplied from combined heat and power plants using bio-based fuels. For the heat pump solutions, cases are analyzed where the electricity supply is from coal-fired condensing power plant or fossil gas combined cycle power plant as baseline scenario, and from a combination of improved fossil power plants and non-fossil power plants as long-term scenario. The analysis considers the entire energy chain from natural resources to the final energy services. The results show that the BBR heat pump heated building use the most primary energy compared to the other two alternatives. Lifecycle cost is reduced by about 7-12% when district heating is used instead of heat pump for a BBR code-compliant building. This study shows the importance of lifecycle and system-wide perspectives in analyzing the resource efficiency and climate impacts as well as economic viabilities of heating solutions for houses.

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