# 6 2022

Defence of Thesis 9th of December: Zhongxuan Liu

Zhongxuan Liu has submitted the following academic Thesis as part of the doctoral work at the Norwegian University of Science and Technology (NTNU), Department of Energy and Process Engineering:

Performance Improvements of Standalone Liquid Air Energy Storage
Zhongxuan Liu
She will defend her Thesis Friday 9th of December in the presence of first opponent Alessandro Romagnoli, (Nanyang Technological University, Singapore) and second opponent Chief Research Scientist Sturla Sæther (Equinor, Norway). Supervisor has been Prof. Truls Gundersen at NTNU EPT.

Zhongxuan has studied the use of liquid air to store electrical energy from renewable energy sources such as solar and wind, in times of surplus production. Liquid Air Energy Storage (LAES) involves three core processes: (1) Charging the system by using surplus electrical energy or/and low market price on electrical energy, to cool and liquefy air, (2) the liquid air is stored in insulated cryogenic tanks, and (3) power is produced by re-gasification and expansion of air when the energy prices are high and/or there is a demand in the market.

To achieve the highest possible Round-Trip Efficiency (RTE), hot and cold thermal energy recovery is used in the LAES process. Multi-component fluids are used to transfer cold thermal energy from re-gasification to liquefaction, while hot thermal energy storage is transferred from the compression part of the liquefaction to the expansion part in the re-gasification by thermal oil. Compression and expansion of air occurs in multiple steps with intermediate cooling and pre-heating, and the number of steps has been optimized. The results show an improvement in the performance of RTE from 54.4 to 66.7%.

Defence of Thesis 16th of December: Håkon Selvnes

Håkon Selvnes has submitted the following academic Thesis as part of the doctoral work at the Norwegian University of Science and Technology (NTNU), Department of Energy and Process Engineering:

Development of cold thermal energy storage for industrial applications
Håkkon Selvnes
He will defend his Thesis Friday 16th of December in the presence of first opponent Prof. Ana Ines Fernández Renna (Universitat de Barcelona, Spain) and second opponent Dr. Jørn Stene (COWI AS, Norway). Supervisor has been Prof. Armin Hafner at NTNU EPT.

Håkon has studied the possibilities of using cold thermal energy storage (CTES) in industrial refrigeration systems for peak shaving of the power consumption. The work has included mapping of possible technologies and identifying optimal solutions for larger refrigeration systems.

To increase the efficiency and performance of this technology a new thermal refrigeration system using novel heat exchanger plates designed for CO2 as refrigerant, was developed and constructed. Thermal energy is stored in a phase change material (PCM) with a freezing point fitting the refrigeration system, and large quantities of energy is stored in the phase transition between liquid and solid. The thermal energy storage system has two operating modes: (1) Storage of cold thermal energy by circulating cold, evaporated CO2 through the plates resulting in freezing of the PCM at the plate surface, and (2) Discharging of the cold thermal energy storage by circulating hot, condensed CO2 through the plates resulting in melting of the PCM. Different PCMs and conditions for the refrigerant has been tested in the laboratory, in addition to mapping of thermal properties of the PCMs. The results show that the concept works and that the temperature difference between the refrigerant and the PCM is the most important factor due tor the heat transfer in both modes. Further, and optimization of the design parameters of the thermal energy storage to fit other cooling demands is possible, and the concept is thus, suitable for several different cooling systems, temperature levels, required storage capacities and power requirements.

New funding for HighEFF
«Novel Emerging and Innovative Concept”

The second call for NEIC proposals was announced with a deadline for applications, September 30, 2022, and the committee received seven applications in total. The applications have been evaluated by Nancy Jorunn Holt (Hydro), Arve Solheim (Enova); Jens Olgard Dalseth Røyrvik (NTNU), Petter Nekså (SINTEF), Camilla Claussen (SINTEF) and Arne Petter Ratvik (SINTEF), resulting in two new NEIC projects:

ITChES Integration of ThermoChemical Energy Storage. The aim is to analyse the performance potential of selected steam-absorption thermochemical energy storage (SA-TCES) compounds to recover excess heat in the range of 120-300°C in a lab scale reactor and provide a techno-economic study for a large-scale implementation in industry processes. The project is led by SINTEF Energy Research together with SINTEF Industry

TES-AS: Monitoring and analysis of a pilot thermal energy storage (TES) unit to supply Air Conditioning (AC) in commercial refrigeration systems. This project aims to demonstrate TES technology developed in HighEFF to reduce the required installed capacities of supermarket refrigeration systems and improve energy efficiency. The project is led by SINTEF Energy Research together with NTNU-EPT and REMA 1000.

The next (and last) announcement for novel emerging and innovative concepts will be in December with a deadline in January 2023.

HighEFF Cross Sector Workshop: making plans for the landing and next take-off

HighEFF started in 2016 with a vision of a joint effort for creating competitive, energy efficient and environmentally friendly industry for the future. No it is time for HighEFF partners to review and discuss the work plan for the Centre’s remaining period until 2024. Read more
Petter Røkke

HighEFF Contacts:

Centre Manager: Petter Røkke
Editorial: Ingrid Camilla Claussen
Feel free to share this copy with a colleague or friend.
Do you want to subscribe to the newsletter - Subscribe-site

Kind regards
Petter E. Røkke, FME HighEFF Center Director

HighEFF Website

Bunnblokk HighEFF
facebook twitter