Project Details
Projekt
Scalable virtual test bench for the integrated design and control of heat pumps and thermal storage in Carnot Batteries: Smooth
Subject Area
Energy Process Engineering
Term
since 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 526154539
Energy storage is essential for decentralized energy markets with high penetration of energy from renewable sources. Therefore, it is necessary to include extensive electricity storage capacities at all scales. While electric batteries will be limited at large scale, Carnot Batteries are promising technologies with potential applications in urban energy systems. Carnot Batteries can be integrated into energy hubs. If there is a surplus of electricity from renewable energy sources, a Carnot Battery stores the surplus. However, due to the interactions between the components and their dynamic operation due to the fluctuations of renewables, the system's efficiency strongly depends on the design and operation. Assessing the economic feasibility of Carnot Batteries accurately requires integrated design approaches. An integrated design of the components and operating strategy already in the early design stages maximizes the potential of Carnot Batteries. This project (two funding phases) provides a fluid- and off-design dependent 1D-scalable virtual test bench that can be used for inverse system design and in-depth assessment. The project identifies use cases for Carnot Batteries in urban energy systems in the first funding phase. Therefore, a simplified Carnot Battery model is integrated into an early-stage, open-source planning tool (EHDO). Based on the mathematical optimization of the design and schedule for the Carnot Battery, system requirements can be extracted. While focusing on the charging process, the project derives heat pumps, thermal storage, and controller requirements. Existing thermal storage models are reformulated and integrated into open-source simulation model libraries (AixLib/VCLib). These models are used in hardware-in-the-loop experiments. The experimental setup allows analyzing the interaction between a real heat pump with two different refrigerants and two different emulated thermal storage technologies at the lab scale. Based on experimental validation, a scalable virtual test bench will be set up. The second funding phase scales up the virtual test bench to assess the optimal design and control at a lab scale and urban energy system scale. Therefore, the virtual test bench is extended by an off-design turbo compressor model. Using integrated design optimization, the design and control parameters are defined. The optimal control parameters are experimentally validated in the lab. In the last step, the extended and validated virtual test bench is scaled up to match the proposed design of the planning tool in funding phase one. The optimal operation schedule assumed by the planning tool is compared to the realistic operation shown by the virtual test bench. Based on potential deviations, new operational boundary conditions can iteratively be evaluated with EHDO. Therefore, the combination of EHDO and scalable virtual test bench pave the way towards economically feasible Carnot Batteries in urban energy systems.
DFG Programme
Priority Programmes
