Molten Salt Based Nanofluids for Solar Thermal Power Plant: A Case Study

Abstract

This work presents the effect of using molten salt-based nanofluids for performance enhancement of Concentrated Solar Power (CSP) plant. The study is carried out in the context of Pakistan, a country that has been struggling with energy crises for a very long time. Previously, it has been shown that a CSP plant in Pakistan is a feasible option. This paper aims to find an optimal combination of nanoparticles and molten salt for a CSP plant in Pakistan. The selected site Nara desert, Nawabshah in the province of Sindh receives an annual direct normal irradiance of 1955 kWh/m2. A 100 MW Parabolic Trough Collector (PTC) plant is modeled using the System Advisor Model (SAM) and is integrated with thermal energy storage of up to 10 hours. The model is validated by comparing results with commercial-scale plants. From literature, nanoparticles with the highest share of usage in performance enhancement of PTC collectors (CuO, Al2O3, and TiO2) with different fractions are selected and Hitec Solar Salt is considered as the base fluid. Parametric optimization is carried out for each of the working fluids. The performance is compared based on annual power generation, capacity factor, plant efficiency, and required Thermal Storage volume. The comparison shows that by using nanofluids, the annual power generation, capacity factor, and efficiency are increased by 8.86%, 8.88%, and 8.9% respectively, whereas the volume of thermal storage is reduced by 36.02%. The optimal fraction of nanoparticles is found to be 1%, 2%, and 5% for CuO, Al2O3, and TiO2, respectively.