## 1 Introduction
A dynamic solar field (SF) and thermal storage system (TSS) model of a 1 MW solar tower power plant was implemented in Beijing using Modelica software. The transient behaviour of charge storage and release processes for inlet and outlet steam quality was tested [8]. A proposed model was designed to provide a complete simulation of a thermocline tank operated at the lowest computing cost and to address the shortcomings of models developed in the previous studies. The suggested model was then integrated into a system-level model of a 100 MWel solar tower power plant to study the storage capability in long-term service. The heliostat array and solar absorber tubes were modelled using DELSOL software, whereas the transient absorber tubes response was simulated using SOLERGY software. The study showed that the efficiency of the thermocline tank in accumulating and releasing thermal energy is approximately 99% year-round. Despite the excellent level of thermal efficiency, the structural stability of the thermocline tank remains a problem due to the high thermal expansion of the internal quartzite stone at high temperatures of the molten salt [9]. A 50 MWel parabolic trough power plant has been modelled with (TRNSYS@ software, 2007). Two heat transfer fluids (thermal oil and molten salt) were applied in this model. Seven operation strategies for charging and discharging modes were analysed to determine the most appropriate mode of operation that will minimise the difference in annual return between the two systems [10]. A parabolic trough power model was developed using APROS. A precise specification of the control response structures and operating approach was implemented to ensure appropriate dynamic performance. The operating strategies used in this model were also proven to be effective in enhancing power plant output and improving power plant operating hours using TSS compared to the operator's choices under cloudy sky conditions [11]. The periodic processes of molten salt storage system thermolines for parabolic trough solar plants were systematically evaluated using two temperature models. These models were designed by Fluent 6.1 and investigated with measured data. It was found that cycle efficiency is improved for smaller Reynolds numbers of molten salt, larger aspect ratios (distance of flow of molten salt in half a cycle relative to the diameter of the filler particles), and larger tank height. It was shown that the diameter of the filler particles and the capacity of the tank significantly affect the efficiency of the cycle [12]. A ceramic honeycomb TSS was modelled for a 10 kW solar air Brayton cycle system in this study using steady-state cycle analysis. The TSS showed very good operational efficiencies under the charge and discharge experimental tests, which were 79.6% and 76.5%, respectively. This study provides a contribution to the designing and modelling of TSS for solar-air Brayton cycle systems and to the analysis of the power plant operation strategy [13]. The binary nitrate (KNO\({}_{3}\) + Ca (NO\({}_{3}\))\({}_{2}\)) with a melting point of 116.9 \({}^{\circ}\)C was chosen as the heat storage media in this research. The objective of this study was to achieve a stable and constant heat discharge performance of the TSS with a single tank of molten salt. A comparative study was undertaken of three different inlet velocity conditions, such as a steady value, automatic adjustment, and manual adjustment. According to the results, the heat discharge power decreases with increasing heat discharge period at a constant inlet velocity. The heat discharge period reduces as the inlet velocity increases, but the heat discharge power increases as the inlet velocity increases. The heat discharge power under automatic and manual adjustment of inlet speed varies by \(\pm\)3% and \(\pm\)10% from the set value, respectively [14].