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Water Efficiency
Published in Steve Doty, Commercial Energy Auditing, 2020
Distillation. Water distillation occurs naturally on earth and deposited as rain. Distilled water can be manufactured by heating water until it evaporates and then condensing it in a clean container. The process relies on water boiling at a lower temperature than anything else within the water, such that only H2O is condensed. Distilling water requires considerable energy and is costly when the heat energy has a price tag. Distillation effectively separates water from minerals and biological contaminants, but will carry with it any substance with a boiling point equal to or lower than water such as solvents or oils.
Nuclear Reactor Fluid Mechanics
Published in Robert E. Masterson, Nuclear Reactor Thermal Hydraulics, 2019
for hemispherical ones (i.e., for ones that stick directly to the surface). Here, the value of Δp is given by Δp = pIN − pOUT where pIN is the internal pressure and pOUT is the external pressure of the bubble. Notice that the internal pressure must always be greater than the external pressure for a bubble to form. These equations can also be used to understand the process of bubble formation in reactor fuel assemblies when nucleate boiling occurs. We will examine nucleate boiling and how it affects the nuclear heat transfer rate in Chapter 23. Finally, surface tension can be reduced by adding impurities to the wetting fluid. In fact, it is possible to design certain chemicals called surfactants to decrease the surface tension of a particular liquid by weakening the molecular bonds between the adjacent molecules. This causes fluids such as water to better adhere to certain surfaces. Sometimes additional chemicals are added to the reactor coolant to improve the heat transfer rate by increasing the number of nucleation sites or by decreasing the wetting angle of the coolant. Normally, the water chemistry of the cooling water must be very carefully controlled to prevent unwanted impurities from depositing on the surfaces of the fuel rods and fouling the tubes in the steam generators of PWRs. Some impurities in the water system can be a good thing, but too many impurities can be disastrous especially if they plate out on the surfaces of the fuel rods and cause the rods to prematurely fail by reducing the overall heat transfer rate. Normally, distilled water is used in reactor coolant systems to minimize the number of unnecessary minerals in the coolant. In many countries, coal-fired power plants have adopted a similar practice as well.
Water Treatment and Purification
Published in P.K. Tewari, Advanced Water Technologies, 2020
The quality of water required for different processes varies over a wide range. In many cases, the quality of water has an impact on the quality of the finished product and influences the economics of the processing. Some processes may not require any treatment or only minimal treatment of raw water for use, while some other processes may need only a reduction in bicarbonate hardness. On the other hand, quite a few industrial processes may require very pure high-quality water, such as distilled water or demineralized water free from impurities.
Tribological performance and mechanism of 2D calcium borate nanoslice capped with stearic acid in rapeseed oil
Published in Journal of Dispersion Science and Technology, 2022
Kecheng Gu, Wang Lin, Xin Yuan, Hongye Peng, Shunxiang Wang, Jiacheng Lv, Zaifa Zhu
All regents used in the experiment were of analytically pure grade except stearic acid (SA) that was of chemically pure grade. Rapeseed oil was provided by Arowana (China), and physicochemical properties of rapeseed oil are listed in Table 1. All regents were used without further purification. Distilled water was used in all synthesis and treatment processes.