Dissertation Defense - Tufan Akba (PHDME)

Tufan Akba – Ph.D. Mechanical Engineering

Prof. M. Pınar Mengüç – Advisor

Prof. Derek K. Baker – Coadvisor

Date: 09.02.2023

Time: 10.00

Location: AB1 412

“Off-Design Performance of Micro-Scale Solar Brayton Cycle”

Prof. M. Pınar Mengüç, Özyeğin University

Assoc. Prof Özgür Ertunç, Özyeğin University

Prof. Hakan Ertürk, Boğaziçi University

Prof. Tuba Okutucu Özyurt, İstanbul Technical University

Asst. Prof. Altuğ Melik Başol, Özyeğin University

Abstract:

A novel methodology to design a micro-scale, solar-only Brayton cycle and assess its on- and off-design performance is presented. The method is applied to generate and assess six thermodynamic layouts over a range of solar irradiation levels. All plants have the same on-design requirements to create a baseline to compare their off-design performance. PyCycle, a thermodynamic cycle modeling library to model jet engine performance, is revised to transform the jet engine performance modeling to solar thermal plant performance modeling and used to create a volumetric receiver component.

For an efficient receiver design process, data-driven surrogate models and surrogate-based optimization algorithms are tested. Then, a response surface surrogate model of the receiver is selected for design optimization to maximize the component-level efficiency. The compressor and turbine maps are scaled for the balance of the plant. Off-design efficiency, mass flow rate, operation range, turbomachinery maps, and maximum power output are presented. Since the methodology can be adapted to all plant sizes, the results are normalized to on-design condition.

The outcome of this study demonstrates the impact of the thermodynamic configuration on off-design performance and provides a methodology to design plants that are more robust across a range of solar irradiation levels and can be operated in a more flexible manner.

Bio:

Tufan Akba attended the Middle East Technical University where he has a Bachelor of Science degree in Mechanical Engineering in 2011 and a Master of Science degree in Mechanical Engineering in 2014. In 2016, he started the Ph.D. program at Özyeğin University Mechanical Engineering department and has been a member of the Center for Energy, Environment, and Economy. His research interest is in thermal system modeling, concentrating solar power, gradient-based optimization, and surrogate-based design.