Efficient energy systems on the basis of cogeneration and heat pump technology

The article contains the results of scientific research and design work related to environmentally safe usage of hydropower potential of the small rivers of the Dnieper basin. The innovative design solutions for extraction of low-grade heat energy of water and systems for its transformation into energy convenient for consumption were offered. It was established that use of renewable low-grade energy of soil is widely used in environmentally safe and economically sound power systems. At the same time hydropower potential is not widely used in hydrothermal heat pump systems. It was proved that existing hydrothermal systems are not always adjusted to actual operating conditions and object location. The evidence was provided that the scientific approach to development of appropriate configuration of hydrothermal collector, to methodology of their optimal mounting and to efficiency determination depending on operating conditions is quite topical issue. The scientific novelty of the new process approach is use of special design of water collector that has modular configuration and consists of several functionally related water sondes. The efficiency of hydrothermal system was scientifically proved. The paper describes the results of experimental research of efficiency of hydrothermal heat pump system where the low-grade heat energy of water is used as a renewable primary heating energy source for functioning of the heat pump. The authors have developed experimental hydrothermal and geothermal heat pump systems to conduct the research. Both collector and ground section of the system have mounted sensors of temperature, pressure and coolant flow velocity. The software for archiving and visualization of obtained data was developed. The research procedure was developed. As part of study, observation data were received and performance efficiency of geothermal and hydrothermal systems was calculated. The comparative analysis of energy systems depending on used renewable energy source was carried out. The conclusion was made that use of hydrothermal heat pump systems is environmentally safe. The data obtained as part of study have great scientific and applied significance for engineering of heat pump energy systems using hydropower potential of the small rivers.

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Towards Sustainable Heat Supply with Decentralized Multi-Energy Systems by Integration of Subsurface Seasonal Heat Storage

Energies ◽

10.3390/en14237958 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7958

Author(s):

Els van der Roest ◽

Stijn Beernink ◽

Niels Hartog ◽

Jan Peter van der Hoek ◽

Martin Bloemendal

Keyword(s):

Heat Pump ◽

Heat Storage ◽

Sustainable Energy ◽

Supply And Demand ◽

Energy Systems ◽

Energy System ◽

Threshold Temperature ◽

Energy System Model ◽

Heat Demand ◽

Seasonal Heat

In the energy transition, multi-energy systems are crucial to reduce the temporal, spatial and functional mismatch between sustainable energy supply and demand. Technologies as power-to-heat (PtH) allow flexible and effective utilisation of available surplus green electricity when integrated with seasonal heat storage options. However, insights and methods for integration of PtH and seasonal heat storage in multi-energy systems are lacking. Therefore, in this study, we developed methods for improved integration and control of a high temperature aquifer thermal energy storage (HT-ATES) system within a decentralized multi-energy system. To this end, we expanded and integrated a multi-energy system model with a numerical hydro-thermal model to dynamically simulate the functioning of several HT-ATES system designs for a case study of a neighbourhood of 2000 houses. Results show that the integration of HT-ATES with PtH allows 100% provision of the yearly heat demand, with a maximum 25% smaller heat pump than without HT-ATES. Success of the system is partly caused by the developed mode of operation whereby the heat pump lowers the threshold temperature of the HT-ATES, as this increases HT-ATES performance and decreases the overall costs of heat production. Overall, this study shows that the integration of HT-ATES in a multi-energy system is suitable to match annual heat demand and supply, and to increase local sustainable energy use.

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