Abstract:

In engineering, especially power generation, heat energy is produced as a product in power generation or as an output of production processes. Generated heat is transferred out of the system for the continuity of the power cycles. This heat transfer process is carried out in three main mechanisms and through many different methods. One of the most preferred methods is to remove the heat to be expelled from the system boundaries by means of a heat transfer fluid. These fluids, also called HTF (Heat Transfer Fluid), have a wide range of uses. One of the most known HTFs is the eutectic molten nitrate salt mixture called as Solar Salt. This mixture is primarily preferred in solar energy systems and also preferred chemistry and other sectors. Thanks to its high temperature stability and thermal properties, it has been in great demand for decades. The most serious problem of this mixture is its high melting temperature (~220 ℃). To reduce this value, various substances are added to Solar Salt and it is aimed both to decrease the melting temperature and to improve its thermal properties. In this study, boron compounds were added to the fluid and some of its properties were analyzed. The fact that our country is the richest country in the world in terms of boron minerals has been the main source of motivation in selecting boron as additive. Amorphous boron oxide, glassy boron oxide and hexagonal boron nitride at 0.5%, 1% and 2% were added to Solar Salt in this study, which was carried out to increase the added value and usage areas of boron and its compounds, and melting point and mass loss analysis were performed. While the melting point values were spread between 215-226 ℃, the mass loss occurred in the range of 0.029% - 1%. As a result of the melting point and mass loss analysis together, the sample containing 2% boron nitride provided the most suitable values.

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