Dynamic Process Simulation of a Molten-Salt Energy Storage System

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.

Download Full-text

A Comparison Study on the Improved Operation Strategy for a Parabolic trough Solar Power Plant in Spain

Applied Sciences ◽

10.3390/app11209576 ◽

2021 ◽

Vol 11 (20) ◽

pp. 9576

Author(s):

Wisam Abed Kattea Al-Maliki ◽

Adnan G. Tuaamah Al-Hasnawi ◽

Hasanain A. Abdul Wahhab ◽

Falah Alobaid ◽

Bernd Epple

Keyword(s):

Power Plant ◽

Solar Power ◽

Storage System ◽

Simulation Software ◽

Plant Performance ◽

Heat Transfer Fluid ◽

Solar Power Plant ◽

Operation Strategy ◽

Parabolic Trough ◽

Control Circuits

The present work focuses on the development of a detailed dynamic model of an existing parabolic trough solar power plant (PTSPP) in Spain. This work is the first attempt to analyse the dynamic interaction of all parts, including solar field (SF), thermal storage system (TSS) and power block (PB), and describes the heat transfer fluid (HTF) and steam/water paths in detail. Advanced control circuits, including drum level, economiser water bypass, attemperator and steam bypass controllers, are also included. The parabolic trough power plant is modelled using Advanced Process Simulation Software (APROS). An accurate description of control structures and operation strategy is necessary in order to achieve a reasonable dynamic response. This model would help to identify the best operation strategy due to DNI (direct normal irradiation) variations during the daytime. The operation strategy used in this model has also been shown to be effective compared to decisions made by operators on cloudy periods by improving power plant performance and increasing operating hours.

Download Full-text

Generalized diagrams of energy storage efficiency for latent heat thermal storage system in concentrated solar power plant

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2017.10.153 ◽

2018 ◽

Vol 129 ◽

pp. 1595-1603 ◽

Cited By ~ 12

Author(s):

Hermes Chirino ◽

Ben Xu ◽

Xinhai Xu ◽

Penghua Guo

Keyword(s):

Energy Storage ◽

Power Plant ◽

Latent Heat ◽

Solar Power ◽

Storage System ◽

Thermal Storage ◽

Solar Power Plant ◽

Storage Efficiency ◽

Concentrated Solar Power ◽

Energy Storage Efficiency

Download Full-text

Volume Sizing for Thermal Storage With Phase Change Material for Concentrated Solar Power Plant

Volume 1: Combined Energy Cycles, CHP, CCHP, and Smart Grids; Concentrating Solar Power, Solar Thermochemistry and Thermal Energy Storage; Geothermal, Ocean, and Emerging Energy Technologies; Hydrogen Energy Technologies; Low/Zero Emission Power Plants and Carbon Sequestration; Photovoltaics; Wind Energy Systems and Technologies ◽

10.1115/es2014-6321 ◽

2014 ◽

Cited By ~ 2

Author(s):

Ben Xu ◽

Peiwen Li ◽

Cholik Chan

Keyword(s):

Power Plant ◽

Phase Change ◽

Phase Change Material ◽

Storage Tank ◽

Solar Power ◽

Heat Storage ◽

Storage System ◽

Thermal Storage ◽

Concentrated Solar Power ◽

Change Material

With a large capacity thermal storage system using phase change material (PCM), Concentrated Solar Power (CSP) is a promising technology for high efficiency of solar energy utilization. In a thermal storage system, a dual-media thermal storage tank is typically adopted in industry for the purpose of reducing the use of the heat transfer fluid (HTF). While the dual-media sensible heat storage system has been well studied, a dual-media latent heat storage system (LHSS) still needs more attention and study; particularly, the sizing of volumes of storage tanks considering actual operation conditions is of significance. In this paper, a strategy for LHSS volume sizing is proposed, which is based on computations using an enthalpy-based 1D model. One example of 60MW solar thermal power plant with 35% thermal efficiency is presented. In the study, potassium hydroxide (KOH) is adopted as PCM and Therminol VP-1 is used as HTF. The operational temperatures of the storage system are 390°C and 310°C, respectively for the high and low temperatures. The system is assumed to operate for 100 days with 6 hours charge and 6 hours discharge every day. From the study, the needed height of the thermal storage tank is calculated from using the strategy of tank sizing. The method for tank volume sizing is of significance to engineering application.

Download Full-text