Dynamic optimization with flexible heat integration of a solar parabolic trough collector plant with thermal energy storage used for industrial process heat. (1st September 2022)

• Record Type: Journal Article
• Authors: Immonen, Jake; Powell, Kody M.
• Is Part Of: Energy conversion and management. Volume 267(2022)
• Publication Date: 2022-09-01
• Subjects: Solar parabolic trough collector -- Flexible heat integration -- Solar industrial process heat -- Dynamic modeling -- Dynamic optimization -- Levelized cost of heat; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2022.115921
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Modeling of a solar industrial process heat plant with thermal energy storage. Optimization with flexible heat integration increases solar efficiency by 7.5%. 22.2% of emissions can be reduced using a solar industrial process heat plant. Detailed optimized operation for various solar conditions presented. 6.7% relative decrease in levelized cost of heat is achieved through optimization. Abstract: There is an increasing need to reduce fossil fuel consumption used for industrial process heat to slow the effects of climate change. Using solar thermal heat is a viable way to replace fossil fuel use, but solar industrial process heat plants have limited implementation due to large upfront costs and inefficiencies from the inherent variability from solar energy. Having more flexible and optimized control over these plants can enable them to be more efficient. In this work, a solar industrial process heat plant with thermal energy storage that can flexibly collect and deliver heat to two industrial processes (flexible heat integration) is dynamically modeled with control setpoints found by a dynamic optimization method. The optimized case can increase the solar efficiency of the plant by 7.5% on average relative to a base case. Results show that it is best to collect heat at lower temperatures for all but ideal solar conditions, only medium to high quality heat should be stored in large quantities, and exchanging heat with a lower temperature heat sink is generally more efficient. The optimized case is able to reduce the levelized cost of heat of the plant to $31.83/MWhth compared to a base case value of $34.10/MWhth . The optimized case can reduce emissions by 22.2% compared to a plant which uses only natural gas. This work shows that dynamic optimization with flexible heat integration can be a cost-effective way to increase efficiency so that more of these types of plants can be implemented.