Essay assingment
aaa6j
article.docxInstructor: MS.JAMIE TRUSTY
Name: ALI ALRAHIN
Course: Eng1010
Date: 3/27/2015
Salt Heat Transfer in CSP
SUMMARY The photovoltaic energy prices have continued to drop as temperatures for concentrated solar power (CSP) towards continue to increase. These changes have led to the investigation of how salt can be used in CSP to reduce costs of operation, increase plant efficiencies, as well as enabling operation at high temperatures. Raising the temperatures of through plants using synthetic or organic oil heat transfer fluids (HTF) from the standard 400 to 500 degree through the use of salt, will allow the steam turbines more efficiently.
Salts are more advantageous than oil based HTF in terms of prices, density and retention of energy. When the liquid is hot, storage and expansion can be done in a larger tank making it easier to add in heat storage and minimize the need for added tanks and heat exchangers. In addition, salts cause less pollution, are non-flammable, readily available, exhibit lower vapor pressures and save on cost. In some cases, synthetic oils may spill and cause fire hazards but molten salt on spilling will solidify and can easily be cleaned by scooping.
Even with these advantages, salt cause pipes to rupture if the molten salt solidifies due to blackout or cooling below the melting point. Absorbers and receiver tubes which is the heat collecting elements are at risk of permanent damaged if they are filled with frozen salt. The risk of freezing can be ensuring the circulating system is warm through the use of electric heaters.
The melting point of these salts can be lowered to as 30 degree by incorporating ingredients hike lithium nitrate and creating higher salt blends. The US department of energy has continued to support the research on the use of salts instead of oil in various areas including Solar Millennium, Germany, Seville, Spain and Abengoa Solar.
https://www.asme.org/engineering-topics/articles/heat-transfer/salt-heat-transfer-fluids-in-csp
