City Research Online

Thermodynamic modelling and real-time control strategies of solar micro gas turbine system with thermochemical energy storage

Yang, J., Xiao, G., Ghavami, M. ORCID: 0000-0002-0772-7726, Al-Zaili, J. ORCID: 0000-0003-4072-2107, Yang, T., Sayma, A. I. ORCID: 0000-0003-2315-0004 and Ni, D. (2021). Thermodynamic modelling and real-time control strategies of solar micro gas turbine system with thermochemical energy storage. Journal of Cleaner Production, 304, 127010. doi: 10.1016/j.jclepro.2021.127010

Abstract

Distributed solar gas turbine systems with thermal energy storage are expected to overcome the intermittence and instability of solar irradiance and produce reliable and flexible electricity for remote districts and islands. Here, a mathematical model is developed for a 10 kWe solar micro gas turbine (MGT) system with thermochemical energy storage (TCES) to study the system thermodynamic characteristics at real-world direct normal irradiation (DNI) variations. Real-time control strategies aiming for stable operation and set point tracing are proposed and implemented in transient simulations to analyze the control effect against both short- and long-term DNI disturbances based on system dynamics. Results show that, by regulating the output power, rotational speed (N) is kept constant, and system responses are smoothened (e.g., less than 5.8% fluctuation of the mass flow rate). Power regulation also enables a constant turbine outlet temperature (TOT) and the optimal overall performance (e.g., output power and total efficiency exceeding 14 kWe and 14%, respectively). By combining power and bypass regulations, N and TOT can simultaneously remain constant while outputting a stable power of 12.6 kWe ±5% under 750–820 W/m2, with a sharp drop to 500 W/m2. For favorable weather, N-TOT simultaneous control can guarantee the high and stable system performance. If massive clouds appear, constant TOT operation is more advantageous during peak load demand for larger electricity generation, while constant N operation is preferable during low power demand for smoother turbine operation. Furthermore, the addition of TCES smoothens the performance variation and prolongs the generation duration. TCES also allows constant TOT operation to store up to 32% more energy than constant N and output 18–28 kWh more energy during daytime operation, thanks to the higher operating temperature. Overall, the proposed real-time control methods reduce the dependency on fossil fuel combustion and contribute to the stable, safe, and efficient operation of a distributed high-percentage-solar-share MGT system.

Publication Type: Article
Additional Information: ©2021 Elsevier Ltd. All rights reserved. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0. The article has been published in Journal of Cleaner Production, DOI: https://doi.org/10.1016/j.jclepro.2021.127010
Publisher Keywords: Solar-MGT, Thermochemical energy storage, Thermodynamic model, Control strategies
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
T Technology > TD Environmental technology. Sanitary engineering
Departments: School of Mathematics, Computer Science & Engineering > Engineering > Mechanical Engineering & Aeronautics
Date available in CRO: 25 Oct 2021 13:51
Date deposited: 25 October 2021
Date of acceptance: 3 April 2021
Date of first online publication: 15 April 2021
URI: https://openaccess.city.ac.uk/id/eprint/26941
[img] Text - Accepted Version
This document is not freely accessible until 15 April 2022 due to copyright restrictions.
Available under License Creative Commons Attribution Non-commercial No Derivatives.

To request a copy, please use the button below.

Request a copy

Export

Downloads

Downloads per month over past year

View more statistics

Actions (login required)

Admin Login Admin Login