A Quasi-Steady State Model of a Solar Parabolic Dish Micro Gas Turbine Demonstration Plant

Abstract

In the framework of the European Optimised Microturbine Solar Power system (OMSoP) project, a novel energy system for solar electricity production was developed, based on the integration of the solar dish technology with Micro Gas Turbines (MGT). A pilot plant with a capacity of 5–7 kWe was realized and installed at the ENEA Casaccia site (Rome) and went under testing to validate the feasibility of the technology and improve the current design. The present work deals with the development of a quasi-state system model, built in the Engineering Equation Solver environment, composed of different modules that correspond to the main system components. The system model was used to define the optimal system parameters, to help the elaboration on an operational strategy to maximize the overall plant efficiency, and to guide the improvement of the single components in view of their optimised design. From the analysis it emerged that the system in design conditions is able to generate, in nominal conditions, 4.5 kWe instead of the expected 5 kWe due to the limitation of the stator current to 13 A, while maximum levels of 5.6 kW could be achieved by “overcharging” the high-speed generator up to 15 A and operating the MGT at the very high speed of 150 krpm. From the transient simulation of the demo system on an annual basis, the maximum average output power is 3.58 kWe. Regarding the cycle efficiency, the annual averaged value is about 17%, whereas the target value is 21%. The improvement of the generator only does not seem to significantly increase the power output on the annual basis (3.75 kWe vs. 3.58 kWe). Differently, the improvement of the solar dish, with the upgrade of the other system components, would significantly increase the system power output to around ~10 kWe.

Annual performance evaluation of a hybrid concentrated solar–micro gas turbine based on off-design simulation

“…The quasi-steady approach cannot capture dynamics of the system. Acknowledging that the dynamic response of the MGT system in much faster than the changes in boundary condition and resolution of this study, neglecting these dynamics does not affect the performance of the system in annual scale [ [43] , [44] , [45] , [46] ].…”

“…Lanchi et al [ 36 ] presented the simulation procedure based on components maps to analyse the behaviour of pure solar MGT of the project OMSoP in different meteorological conditions to define the optimal system parameters and control strategy. Based on their results, the annual average output power of a system with a nominal rate of 4.5 kW was 3.58 kW.…”

“…In almost all of the past research, the flow configuration between the turbomachinery, recuperator, and receiver was assumed to be fixed. A limited number of studies have evaluated the annual performance and addressed the off-design condition of a solar-MGT system, while the off-design behaviour of the components and their effects on the annual performance of such systems is rarely ever addressed for a pure solar MGT ([ 34 , 35 ]) and few other solar hybrid systems ([ 3 , 36 , 37 ]). Particularly, the available literature does not consider the effect of ambient temperature on both the performance of the MGT components and heat loss in the solar receiver for a complete operating range of the system.…”

Triple-Objective Optimization of SCO2 Brayton Cycles for Next-Generation Solar Power Tower

“…Firstly, it is important to acknowledge that a larger heat storage temperature difference (∆T) between the two heat storage tanks can significantly improve each cycle's compatibility with the heat storage unit, thus playing a crucial role in the plant's efficient operation [48,49]. Therefore, ∆T is selected as a critical performance index, as expressed in Equation (9).…”

“…The primary objective of solar thermal power technology development is to enhance thermal efficiency, elevate specific work, and accomplish large-scale heat storage. Among the available solar thermal power technologies, including the solar power tower (SPT) [7,8], solar dish collector [9,10], linear Fresnel reflector [11,12] and parabolic trough collector [13][14][15], the SPT is a promising option that is expected to meet the above development requirements [16].…”