Supercritical CO2 Power Cycle for Solar Applications: Thermodynamic Analysis and 1D Turbomachinery Design

Supercritical CO2 (s-CO2) Brayton cycle is indicated as one of the possible substitutes of the traditional steam cycle, that is currently used to produce the biggest share of electricity. Specifically, one of main candidates is the Brayton recompression cycle, that has been investigated for a wide range of operating conditions. This work is originated from the need to develop a tool that integrates the cycle design to a more detailed turbomachinery design. The results of the cycle design confirm its high thermodynamic efficiency and allow to calculate the mass flow needed to match the desired power output. Then, a preliminary and mean line design integrated code is developed for compressors and expanders. The preliminary design is based on the Baljé diagrams and it allows to estimate the number of stages and the diameter recommended to achieve the optimum efficiency. The mean line design provides a more advanced sizing and performance estimation, that is based on traditional relations as well as on the most recently improved correlations available in literature for supercritical fluids. The models are validated with the results of designs found in literature and with the few experimental data available. The methodology developed is applied to a case study: the Brayton recompression cycle is compared to the Rankine cycle in the solar thermal power plant PS10, a 11 MW solar tower located near Seville, Spain. The tool developed is accurate in the prediction of the cycle operating conditions and it provides a robust design tool for the turbomachinery equipment.

Subject

turbomachinery design
power cycle
supercritical CO2

To reference this document use:

http://resolver.tudelft.nl/uuid:466260b5-24eb-4979-912d-5c2080370021

Part of collection

Student theses

Document type

master thesis

Rights

Files

PDF

MSc_Thesis_S_Spazzoli.pdf

5.66 MB

Close viewer