Dynamic Process Simulation of a Molten-Salt Energy Storage System

Abstract

The main objective of this work was the construction of a numerical model using Advanced Process Simulation Software to represent the dynamic behaviour of a thermal storage system (TSS). The storage model was validated by comparing the results with the measured data of the storage process of the Andasol 2 solar power plant. Subsequently, a system analysis and system optimisation were carried out, and the stand-alone concept of the thermal storage system is presented. Stand-alone refers to an isolated use of the storage system without a solar power plant. During power peaks, this storage medium is heated with excess electrical power and later returned to the electrical grid through a steam cycle. Then, the system was optimised by modelling four models based on the type of storage medium and the temperature difference of the storage system. The four models, Andasol 2, SSalt max, Hitec, and Carbonate, were evaluated and compared in terms of the improvement in capacity and efficiency that can be achieved. The comparison shows that the preferred storage medium is carbonate salt due to the increases in both efficiency and capacity. The greatest increase in efficiency in terms of power generation can also be achieved with the Carbonate model (18.2%), whereas the amount of increase was 9.5% and 7.4% for each of SSalt max and Hitec, respectively. The goal of this analysis and system optimisation of a thermal salt storage system is to stabilise and relieve the local power grid.

Molten Salt Thermal Energy Storage for Renewable Energy: System Design, Materials, and Performance

“…This HTF can then be utilized to produce electricity or stored for future use. The discharging phase involves the reverse process, where the HTF is utilized to heat the molten salt, which is then conveyed back to the storage tank [5].…”

Advances in Process Modelling and Simulation of Parabolic Trough Power Plants: A Review

“…The most important programs for dynamic simulation can be mentioned in Table 2, e.g., Advanced Process Simulation Software (APROS) [6][7][8][9][10][11][12][13], ASPEN Plus DYNAMICS [14,15], ASPEN HYSYS, RELAP [16], MATHEMATICA [17], DYMOLA (based on Modelica language) [18][19][20][21][22], SIMULINK [23], and TRNSYS [24]. These programs originated from improvements made over a long period of time by universities or companies, and, generally, are not freely available.…”

“…The comparison displays that the sliding pressure strategies are more efficient in terms of net electrical power production than the fixed pressure strategies. Al-Maliki et al performed some studies [4,[10][11][12][13][14]43] in which the 50 MW el Andasol II power plant was also modelled using APROS software with all required automation circuits. In addition to the solar field, a thermal storage system operated with molten salt and a detailed dynamic model of the power block were also carried out in this study.…”

Parabolic Air Collectors with an Evacuated Tube Containing Copper Tube and Spiral Strip, and a New Cavity Receiver: Experimental Performance Analysis

“…Researchers have recently used various materials to design, develop, and assess parabolic sunray air heaters [10]. Absorbent tube design is one aspect that significantly affects the amount of energy that can be obtained from sunlight [11][12][13]. Several studies have lately been undertaken on the effect of heat exchanger geometry on sunray collector performance [14][15][16][17][18][19][20][21][22].…”