Banca de QUALIFICAÇÃO: CAIO CEZAR NEVES PIMENTA
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : CAIO CEZAR NEVES PIMENTA
DATE: 22/04/2024
TIME: 16:00
LOCAL: Plataforma Microsoft Teams
TITLE:
KEY WORDS:
PAGES: 65
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUBÁREA: Engenharia Térmica
SPECIALTY: Termodinâmica
SUMMARY:
The possibility of efficient thermal energy storage has been pointed out as a
competitive advantage for power plants using Concentrated Solar Power (CSP) technology
compared to photovoltaic plants. Energy storage partially compensates for the intermittent
nature of the solar source, providing flexibility to the operator by allowing energy dispatch
when there is no heat source.
Various storage systems for CSP plants exist, depending on the technology adopted
at the plant. In this study, an exergy-energetic analysis was conducted for a Thermal
Energy Storage (TES) system using air as the heat transfer fluid flowing through a
porous medium with optimized geometry for heat transfer. Approximate energy equations
for air and the porous matrix were proposed to facilitate the study with different TES
configurations. Aerodynamic parameters for the flow were obtained through simulations in
the CFD platform Star-ccm+, which also served to validate the proposed approximations.
A numerical model based on the approximate equations was developed. The model
discretizes the domain into finite volumes, solving the solid and fluid energy conservation
equations and fluid mass conservation using the upwind scheme for advective terms and
implicit in time. Simulations of the thermal charge/discharge cycle were conducted for TES
lengths of 6m and a mass flow rate in the porous medium of 0.1 𝑘𝑔/𝑚2𝑠. Initial conditions
(porous medium temperature) and boundary conditions were based on operational data
from the Julich CSP Plant in Germany.
To validate the proposed model, the air discharge temperature in Julich, Germany,
was compared with the model’s prediction. In Julich, an acceptable temperature range
between 640 − 680 ℃was proposed, while in the present study, the corresponding temperature
obtained was 785℃, resulting in a variation of 14% between the results. This indicates that the model needs improvement to reduce the difference.
The results show different profiles of destroyed exergy in each cycle due to heat
exchanges between fluid and solid. Therefore, parameter optimization should be applied for
the specific operational conditions of each project to reduce losses that could compromise
the overall profitability of the system.
COMMITTEE MEMBERS:
Interno - 3138349 - EDGAR AMARAL SILVEIRA
Externo à Instituição - EDUARDO LUCAS KONRAD BURIN - UFPR
Interna - 2115160 - SIMONE MONTEIRO E SILVA