SOLAR ENERGY SOLUTIONS
This article explores new valve designs that improve how molten salt is managed in solar power plants . It shows how these innovations are making solar energy more efficient and reliable .
Advancing molten salt valve technology in CSP systems
By Krishnakumar Viswanathan , Global Engineering Leader and
Vignesh Murugan , Engineer , Flowserve
About the authors Krishnakumar Viswanathan is the Global Engineering Leader for butterfly valves at Flowserve . With 15 years of experience , he specialises in new product development , valve design , actuation system design and testing and evaluation of isolation and control valves . His expertise covers both rotary and linear control valves , including triple and double offset butterfly valves , globe control valves and actuators . Krishnakumar holds a Bachelor of Engineering ( B . E .) degree in Mechanical Engineering .
Vignesh Murugan is an Engineer for butterfly valves at Flowserve valve division . He has 5 years of experience in valve design , specialising in the design of triple offset valves , gate , globe & check valves . Vignesh holds a Bachelor of Engineering ( B . E .) degree in Mechanical Engineering .
Concentrated solar power systems
Concentrated Solar Power ( CSP ) plants have become a pivotal technology in the renewable energy sector , leveraging the sun ’ s energy to produce electricity . One of the critical components enabling the efficiency and reliability of CSP plants is the advanced valve technology used to manage molten salts , which act as both heat transfer fluids ( HTF ) and thermal energy storage ( TES ) materials . This white paper delves into the design considerations , challenges and innovations in valve technology specifically tailored for molten salt applications in CSP plants .
Thermal energy storage and molten salt applications
Thermal energy storage is a pivotal component of CSP plants , enabling them to store excess thermal energy during peak sunlight hours for use during periods when sunlight is unavailable . This capability allows CSP plants to generate
Mixture Type |
Composition |
Melting Point |
|
|
(° C ) |
electricity even at night or on cloudy days , enhancing their reliability and efficiency . Molten salts serve as both a heat transfer fluid ( HTF ) and a thermal energy storage material here . Their ability to store and transfer heat efficiently makes them ideal for this dual role . In addition , molten salts are used as coolants and , in some cases , as fuel in nuclear power plants , as well as electrolytes in hightemperature molten salt batteries .
Why use salt mixtures
Simple salts require substantial energy to melt and degrade faster than mixtures . To optimise their thermal properties , salts like nitrates , carbonates , fluorides and chlorides are combined in specific ratios . These mixtures achieve lower melting points , high boiling points , low vapour pressure and high thermal stability . Few of the combination of salt mixtures and their properties are below :
Highest Operating Temp (° C )
Heat Capacity ( J / g K )
Non-Binary KNO3 334 < 530 1.4 Binary NaNO3-KNO3 221 < 550 1.53 Ternary LiNO3-KNO3-NaNO3 119 < 500 1.681 Quaternary
LiNO3-CaNO3-NaNO3- KNO3
109 < 450 1.689
30 Valve World October 2024 www . valve-world . net