Review article
Simulation-based Estimation of the Optimization Potential of Dynamic Controller Settings for Solar Thermal Combisystems
Oleg Kusyy
; Kassel University, Institute of Thermal Engineering, Kassel, Germany
Klaus Vajen
; Kassel University, Institute of Thermal Engineering, Kassel, Germany
Abstract
Before improving the control settings of solar heating systems with the help of sophisticated predictive algorithms, it is reasonable first to determine or at least estimate the theoretical potential of these improvements and then to decide if they are worthy of implementation. An approach is proposed in this paper which enables the estimation of the theoretical potential of the dynamic control settings optimization for solar heating combisystems. Dynamic optimization was carried out for a solar combisystem with a solar fraction of approximately 35% for the period of an entire year. The theoretical potential of the optimization of the boiler controller settings as well as the fluid mass flow in the collector loop and, consequently, in store loop, was estimated. The solar thermal combisystem was simulated in TRNSYS and optimization was carried out by the binary (n-ary) search algorithm programmed in GenOpt (Generic optimization software). The results showed that the extended fractional savings for the considered combisystem with dynamically optimized mass flow in the collector loop was only 0.3 percent points larger than that for the system with an optimized, but fixed mass flow. The optimization potential of the boiler controller settings turned out to be more promising, showing an improvement of 4.4 percentage points in thermal fractional savings for the system with two instant electrical heaters versus the initial system with a heated volume in the store.
Keywords
Dynamic optimization; Solar thermal combisystems; TRNSYS Simulation
Hrčak ID:
98211
URI
Publication date:
21.12.2012.
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