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

Paper Number: 153826

Thermodynamic Trade-Offs in Brayton High-Temperature Heat Pumps: Impact of Compressor Performance and Heat Exchanger Size 

High-temperature heat pumps (HTHP) are a standard solution to electrify and decarbonize process heat production. To date, commercial HTHP technologies cannot operate much beyond 200°C, but new solutions that can go beyond this threshold are being increasingly researched. Brayton HTHPs are one such solution, leveraging on the expectation that they could feature a maximum heat production temperature of up to 400°C with components of reasonable size and performance. While high maximum operating temperatures characterize Brayton HTHPs, they produce heat over an extensive range of temperatures. Therefore, the average heat production temperature is a parameter that quantifies Brayton HTHP performance better than the maximum one and can be of great importance for process integration. This average temperature can be increased at the cost of COP reduction, primarily if inter-cooled compression is used as a simple modification to the basic thermodynamic cycle. The paper explores the trade-off between performance and heat production temperature, considering practical limitations on the dimension of the cycle heat exchangers, which can be very impactful. Additionally, the analysis focuses on the compressor design, investigating its realistic performance in function of the specific operating conditions characterizing Brayton HTHP. The obtained results comprehensively characterize Brayton HTHP performance and improve the understanding of this novel heat-pumping technology.

Presenting Author: Matteo Benvenuti University of Pisa

Presenting Author Biography: Matteo Benvenuti received his Master's degree in Energy Engineering at the University of Pisa, where he is currently enrolled as a PhD student.
Matteo Benvenuti's research primarily focuses on Brayton systems for high-temperature heat pump and storage applications.

Authors:

Matteo Benvenuti University of Pisa
Guido Francesco Frate University of Pisa
Lorenzo Ferrari University of Pisa