| 1. |
- Pan, Tianyao, 1994-, et al.
(författare)
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A novel gas turbine simulator for testing hybrid solar-Brayton energy systems
- 2022
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 268
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Tidskriftsartikel (refereegranskat)abstract
- A novel gas turbine simulator is developed to establish controllable boundaries for investigating the characteristics of key components in gas turbine based hybrid energy systems under different operating conditions. The gas turbine simulator consists of a compressed air system, an electrical heater, a mass flow controller, a proportional solenoid valve, a dual-flow choked nozzle, and a PLC-based control system. With the proposed control strategy, the fluid parameters, such as temperature, mass flow rate, and pressure, can be automatically regulated to simulate the boundary conditions of a gas turbine under various workloads. Experimental results for both cold and hot states have validated the capabilities of the gas turbine simulator to deliver convergent control results with fast response. The gas turbine simulator has demonstrated considerable performance in stabilizing system boundaries with the precision in terms of pressure control reaching +/- 0.004 bar for steady states, and +/- 0.018 bar to +/- 0.076 bar for transient states with mass flow and temperature perturbations. The gas turbine simulator can also accurately track linear and nonlinear trajectories during operating point migrations, and effectively limit deviations within +/- 0.037 bar.
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| 2. |
- Pan, Tianyao, 1994-
(författare)
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Development of a Novel Gas Turbine Simulator for Hybrid Solar-Brayton Systems
- 2022
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hybrid solar-Brayton systems utilize both solar thermal energy and supplementary renewable fuels to provide controllable and dispatchable power output, which renders them a promising way to meet the growing energy demand and reduce the carbon footprints. However, existing testing facilities for key components in such hybrid systems often fail to accomplish the testing requirements, hence impeding the improvement of the renewable energy share and the overall efficiency. A novel testing facility is urgently needed in order to thoroughly stimulate and analyze the component characteristics.This research work focuses on the development of a gas turbine simulator as an innovative testing facility for hot, pressurized components in hybrid solar-Brayton systems. The dual-flow choked nozzle based flow control has been proposed, explained, and analyzed in comparison to the single-flow layout. The basic idea of gas turbine simulator has been experimentally implemented and validated on a prototype, verifying its functionality. By incorporating a PLC-based control system, an automated gas turbine simulator has been designed and modified based on the prototype. Its performance with regard to stabilizing boundaries and tracking trajectories has been evaluated by experiments.Based on the experimental results, the gas turbine simulator prototype has proven its ability to establish controllable boundary conditions and migrate operating points for the impinging receiver. Through manual adjustments, excellent quasi-steady state performance has been obtained, with the precision for pressure control reaching ±0.005 bar at ambient temperature and ±0.015 bar at high temperature of 797.1-931.5 °C. The manual operation time has been identified at 23.1 s for establishing the receiver boundaries, and at 70 s for changing operating points.With the help of the proposed control strategy, the automated gas turbine simulator has eliminated the need for manual adjustments, and demonstrated the ability to maintain the safe and convergent operation for the receiver. The performance in boundary condition stabilization has been satisfactory, with enhanced steady-state accuracy comparing to the prototype by virtue of the PID controller. The transient-state fluctuations in pressure control have been effectively restrained within an acceptable region with deviations of ±0.018 bar to ±0.076 bar from the desired 2.400 bar operating pressure. The capability of tracking linear and nonlinear trajectories has also been testified, with the precision level between ±0.023 bar and ±0.037 bar.Finally, in view of the good stability, high precision, and rapid response manifested in the experimental studies, the gas turbine simulator has validated its ability to imitate the steady and transient characteristics of gas turbines on the boundaries of the test section. It also grants the possibilities to conduct control variable studies and wide-range transition studies. The gas turbine simulator is a suitable testing facility for the key components in hybrid solar-Brayton systems.
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| 3. |
- Wang, Wujun, 1984-, et al.
(författare)
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Experimental demonstration of a load flexible combustor for hybrid solar Brayton applications
- 2023
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 283, s. 116904-
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Tidskriftsartikel (refereegranskat)abstract
- A novel load flexible combustor has been developed for hybrid solar Brayton applications with any solar share. In this combustor design, the fuel is split into a pilot and a main fuel. The pilot flame is designed for re-igniting the main fuel at any workload in the range of 0-100%. Bypass cooling airflows are innovatively introduced for protecting the fuel flows from unpredictable auto-ignition and undesirable flashback. To evaluate the performances, the combustor has been experimentally demonstrated at its 30% workload with the help of the KTH high flux solar simulator, the KTH dual-flow choked nozzle based gas turbine simulator and an impinging solar receiver. By suddenly turning off the solar simulator and increasing the fuel injection, its performances under hybrid operation have been studied in detail. The results show that the combustor outlet air temperature can be successfully maintained in the range of 914.5 +/- 10 degrees C through the whole hybrid operation test without flashback by adjusting the main fuel injection manually after turning off the solar simulator. The temperature peak on the combustor liner of this test appears at the thermocouple TC3 with a value of 958.1 degrees C, which is significantly lower than the allowable working temperature of the material. The pressure drop across the combustor is within the range of 17.4 +/- 2.5 mbar, which is equivalent to approximately 0.58% of its working pressure.
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