Session: 09-02 / 30-13 joint session: Pumped Thermal Energy Storage

Paper Number: 154187

Part Load Operation of Kilo-Watt Scale Thermally Integrated Supercritical CO2 Pumped Thermal Energy Storage 

Pumped thermal energy storage (PTES), a subcategory of Carnot battery technologies has attracted attention in recent years, mainly because of its ability to use grid arbitrage to convert electricity to be stored as heat(Charging), which can be again converted to electric power(discharging). The benefit of heat as the storage medium is the direct supply of heat for industrial or district heating purposes(heat as output) and the integration of heat sources to support the cycle performance(heat as input) usually in the charging cycle. The latter configuration is referred to as thermally integrated PTES(TI-PTES). A key advantage of TI-PTES is that it allows the integrated heat to be stored together with electricity during charging and used at a later time of high demand while also removing the constraint of cold storage, especially for Brayton cycle-based TI PTES plants.

Leveraging on such a concept, the EU SCO2OP-TES project aims at demonstrating sCO2-based TI-PTES up to TRL 5 through a lab-scale demonstration plant using industrial waste heat as an integrated heat source; the charging and discharging cycles are sCO2-based Brayton heat pump and power cycles respectively, adopting radial turbomachinery for both the hot compressor(charging) and the hot turbine(discharging).

Along with the mean line design and CFD analysis of the sCO2 turbomachines, this study explores the influence of their part load operation on the SCO2OPTES TI-PTES demonstration plant. The study elaborates on the effect of Partial electric loads considered for the hot compressor(high-temperature turbomachine for the charging) and for the hot turbine(high-temperature turbomachine for discharging) on the waste heat recovery unit in the charging cycle, thermal energy storage heat exchanger, recuperator and cooler in the discharging cycle. The separate and combined performance of the charging and the discharging cycles due to variations in thermodynamics and mass flows is evaluated. Lastly, operational constraints are discussed and control strategies are suggested.

Presenting Author: Stefano Barberis University of Genoa

Presenting Author Biography: He received his PhD in Turbomachinery and Advanced Energy Systems Engineering at the University of Genova in 2016. He is a Senior Mechanical Engineer with expertise in renewable energy sources, project management, techno-economical feasibility studies, research activities on energy storage, hydrogen, and renewable energy systems, due diligence, innovation, and technology transfer. He has worked for almost 6 years as part of the Innovation for Energy R&I division at Rina Consulting managing the activities of different European-funded Projects dealing with electrical and thermal power production, renewable energy, hydrogen, and energy efficiency.

Authors:

Syed Safeer Mehdi Shamsi University of Genoa
Stefano Barberis University of Genoa
Kiavash Kamali Politecnico di Milano
Alessandro Romei Politecnico di milano
Giacomo Persico Politecnico di milano
Alberto Traverso University of Genoa