VACUUM-ICE THERMAL ENERGY STORAGE, HEAT SOURCE FOR HEAT PUMPS AND MEANS TO IMPROVE THE CAPACITY OF COOLING

1988 ◽  
pp. 2087-2091
Author(s):  
Joachim Paul
Keyword(s):  
Energy Storage ◽  
Heat Source ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Pumps

scholarly journals Optimized Layouts of Borehole Thermal Energy Storage Systems in 4th Generation Grids

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4405 ◽  
Author(s):  
Hoofar Hemmatabady ◽  
Julian Formhals ◽  
Bastian Welsch ◽  
Daniel Otto Schulte ◽  
Ingo Sass
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heating Temperature ◽  
Storage System ◽  
District Heating ◽  
Temperature Shift ◽  
Heat Pumps ◽  
Optimal Designs ◽  
Practical Implementation

Borehole thermal energy storage (BTES) systems are a viable option to meet the increasing cooling demand and to increase the sustainability of low-temperature district heating and cooling (DHC) grids. They are able to store the rejected heat of cooling cycles on a seasonal basis and deliver this heat during the heating season. However, their efficient practical implementation requires a thorough analysis from technical, economic and environmental points of view. In this comparative study, a dynamic exergoeconomic assessment is adopted to evaluate various options for integrating such a storage system into 4th generation DHC grids in heating dominated regions. For this purpose, different layouts are modeled and parameterized. Multi-objective optimization is conducted, varying the most important design variables in order to maximize exergetic efficiency and to minimize levelized cost of energy (LCOE). A comparison of the optimal designs of the different layouts reveals that passive cooling together with maximizing the heating temperature shift, accomplished by a heat pump, lead to optimal designs. Component-wise exergy and cost analysis of the most efficient designs highlights that heat pumps are responsible for the highest share in inefficiency while the installation of BTES has a high impact in the LCOE. BTES and buffer storage tanks have the lowest exergy destruction for all layouts and increasing the BTES volume results in more efficient DHC grids.

Study of the Melting Behavior in a PCM-Based Thermal Energy Storage

2015 ◽  
Author(s):  
Mohammad Bashar ◽  
Kamran Siddiqui
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Heat Source ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Systems ◽  
Renewable Energy Sources ◽  
Heat Transfer Process ◽  
Convective Cells

Thermal energy storages are becoming important due to their significance in energy conservation as well as for the uninterrupted supply of thermal energy from renewable energy sources. The latent heat-based thermal energy storage systems utilizing phase change material (PCM) are gaining much attention due to some inherent advantages compared to sensible heat-based storage systems. However, the heat transfer process associated with the phase change in a PCM is complex and not well understood. In the present study, the melting process in a PCM-based thermal storage is experimentally studied. Two different configurations of the heat source were considered; horizontal and U-tube heat sources. The results show that the heat source shape has a significant influence on the solid to liquid phase change process (melting). The results also show that for the horizontal heat source configuration, the solid-liquid interface has a wavy profile, which is attributed to the convective cells in the melted domain of the PCM. These convective cells also influence the heat transfer coefficient, which decreased with an increase in the melted fraction. In U-tube configuration, the heat is non-uniformly transferred to the PCM domain.

scholarly journals A Fast-Reduced Model for an Innovative Latent Thermal Energy Storage for Direct Integration in Heat Pumps

2021 ◽  
Vol 11 (19) ◽  
pp. 8972
Author(s):  
Valeria Palomba ◽  
Andrea Frazzica
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Pumps ◽  
Heat Transfer Fluid ◽  
Direct Integration ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Operating Modes

In the present paper, the numerical modeling of an innovative latent thermal energy storage unit, suitable for direct integration into the condenser or evaporator of a heat pump is presented. The Modelica language, in the Dymola environment, and TIL libraries were used for the development of a modular model, which is easily re-usable and adaptable to different configurations. Validation of the model was carried out using experimental data under different operating modes and it was subsequently used for the optimization of a design for charging and discharge. In particular, since the storage unit is made up of parallel channels for the heat transfer fluid, refrigerant, and phase change material, their number and distribution were changed to evaluate the effect on heat transfer performance.

scholarly journals Flexibility Estimation of Residential Heat Pumps under Heat Demand Uncertainty

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5709
Author(s):  
Zhengjie You ◽  
Michel Zade ◽  
Babu Kumaran Kumaran Nalini ◽  
Peter Tzscheutschler
Keyword(s):  
Energy Storage ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Pumps ◽  
Hot Water ◽  
Maximum Temperature ◽  
Heat Demand ◽  
Residential Units ◽  
The Impact

With the increasing penetration of intermittent renewable energy generation, there is a growing demand to use the inherent flexibility within buildings to absorb renewable related disruptions. Heat pumps play a particularly important role, as they account for a high share of electricity consumption in residential units. The most common way of quantifying the flexibility is by considering the response of the building or the household appliances to external penalty signals. However, this approach neither accounts for the use cases of flexibility trading nor considers its impact on the prosumer comfort, when the heat pump should cover the stochastic domestic hot water (DHW) consumption. Therefore, in this paper, a new approach to quantifying the flexibility potential of residential heat pumps is proposed. This methodology enables the prosumers themselves to generate and submit the operating plan of the heat pump to the system operator and trade the alternative operating plans of the heat pump on the flexibility market. In addition, the impact of the flexibility provision on the prosumer comfort is investigated by calculating the warm water temperature drops in the thermal energy storage given heat demand forecast errors. The results show that the approach with constant capacity reservation in the thermal energy storage provides the best solution, with an average of 2.5 min unsatisfactory time per day and a maximum temperature drop of 2.3∘C.

scholarly journals How heat pumps and thermal energy storage can be used to manage wind power: A study of Ireland

Energy ◽  
2018 ◽  
Vol 157 ◽  
pp. 539-549 ◽  
Author(s):  
Inna Vorushylo ◽  
Patrick Keatley ◽  
Nikhilkumar Shah ◽  
Richard Green ◽  
Neil Hewitt
Keyword(s):  
Energy Storage ◽  
Wind Power ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Pumps
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