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Accelerators speed up or shorten the reaction time required for a cement slurry to become a hardened mass. In the case of oilfield cement slurries, this indicates a reduction in thickening time and/or an increase in the rate of compressive-strength development of the slurry. Acceleration is particularly beneficial in cases where a low-density (e.g., high-water-content) cement slurry is required or where low-temperature formations are encountered. Of the chloride salts, CaCl2 is the most widely used, and in most applications, it is also the most economical. The exception is when water-soluble polymers such as fluid-loss-control agents are used.
Aralov, O. V. (Pipeline Transport Institute LLC) | Korolenok, A. M. (Gubkin University) | Berezhansky, N. V. (Pipeline Transport Institute LLC) | Buyanov, I. V. (Pipeline Transport Institute LLC) | Savanin, A. S. (Pipeline Transport Institute LLC)
The article describes the basic principles of mathematical modeling of sampling devices (SD) in order to determine the design of their sampling tubes, allowing to ensure the highest representativeness of samples. The calculations were carried out for slot-type SD that are widely used at present in systems for measuring the quantity and quality of oil. To establish the boundary conditions for mixing the components, the authors substantiated the mixing criteria. To calculate the solution model, a dispersion turbulence model was chosen, implemented in the ANSYS application software. The analyzed components contained in the stream were water, chloride salts, and mechanical impurities. The main results obtained indicate the operability of the mathematical model, which makes it possible to calculate the SD for various incompressible media. The main research results also include the following conclusions. An increase in the content of chloride salts in the stream improves the representativeness of the water samples taken; increased turbulization of the flow can lead not only to an improvement in the representativeness of samples, but, under certain conditions, to their deterioration; in some cases, the representativeness of samples for water and chloride salts may coincide. In the process of research it was noted that it is impossible to obtain the same improvement in the representativeness for all substances contained in oil (in some cases, an improvement in the representativeness of samples for mechanical impurities led to deterioration in the previously achieved representativeness for water). Thus, the task of uniform improvement of the representativeness of samples with respect to water, mechanical impurities and chloride salts was taken as an optimization problem. In the course of research, this problem was solved: the obtained design of the SD allows to improve the representativeness of samples for water by 17.29%, for chloride salts by 21.89 %, for mechanical impurities by 6.77 %.
Pierce, Steven (California State Polytechnic University) | Lukiman, Carinne (California State Polytechnic University) | Shah, Touba (California State Polytechnic University) | Ravi, Vilupanur A. (California State Polytechnic University)
Concentrated Solar Power (CSP) plants provide the twin advantages of energy generation and thermal energy storage. The latter provides CSPs the advantage of persistent power, a feature that is absent in photovoltaic plants. However, there is much to be done to make CSPs competitive with traditional coal- powered plants. Reduction of CSP costs relies on the selection and use of salts with high heat capacity, relatively low melting temperatures and good thermal stability. Chloride salts are viable candidates that fulfill the technical requirements and are relatively low-cost. However, the corrosivity of these salts needs to be addressed. This paper outlines the approach taken to select a promising salt (KCl – 44.5 wt% NaCl), and containment materials (UNS S31600 and UNS N08330 with G10180 as the control/baseline). An experimental approach involving electrochemical testing of candidate alloys (as- received and surface modified) is described. Microstructural characterization included scanning electron microscopy. The selected salt was determined to be a viable candidate as a thermal energy storage medium based on thermodynamic considerations. The containment materials that are compatible with this salt in an argon atmosphere at 700°C are the as-received UNS S31600 and UNS N08330.
In recent years, the solar energy sector has expanded due to interest in clean and sustainable energy generation. The most common method of solar power generation uses photovoltaic (PV) cells, which are limited to cloudless, daytime use.1 Thermal Energy Storage (TES) plants, on the other hand, have the capacity to generate and store energy for use during night and cloudy periods in addition to periods of plentiful availability of sunlight.2 TES plants can use molten salts as a thermal energy storage medium as well as a heat transfer fluid.3 These plants have the ability to store large amounts of thermal energy. The reduction of TES costs relies on the selection of salts that are cheaper and more abundant than the current industry standard, while still maintaining favorable thermodynamic properties such as high latent heat of fusion and high heat capacity.4,5,6
Chloride salts are good candidates due to their low-cost and favorable thermodynamic properties.2’78 However, chloride salts can result in aggressive corrosion attack of the containment materials. Standard structural materials, e.g., carbon or stainless steels, could suffer significant chloridation if they are used to contain the molten salt.9 One method of mitigating this effect is to use corrosion-resistant alloys; however, these alloys can be cost-prohibitive and may not be a viable solution.10 Another method of mitigating the effects of corrosion is to utilize corrosion resistant coatings, which can be cost- effective.11 In this project, pack-aluminized carbon steel and stainless steels, along with the base alloys, were chosen for high temperature salt corrosion testing under a binary KCl – 44.5 wt% NaCl molten eutectic salt.
Logier, Jared (California State Polytechnic University) | Wang, Jason (California State Polytechnic University) | Villalpando, Obed (California State Polytechnic University) | Jalbuena, Alexander (California State Polytechnic University) | Ravi, Vilupanur A. (California State Polytechnic University)
ABSTRACTMolten salts have emerged as viable candidates for thermal energy storage in Concentrated Solar Power (CSP) applications. Candidate chloride salts offer the advantages of being readily available and stable at high temperatures, thus opening up the possibility for increased power generation efficiency. However, molten chloride salts are corrosive; therefore, proper materials selection for plant hardware is vital. Current CSP plants use stainless steels and nickel-base alloys as materials of construction because of the desirable combination of mechanical properties and corrosion resistance. In this research project, the focus was on the corrosion behavior of two different stainless steels (UNS S30400 and UNS S31600) and a carbon steel, i.e., UNS G10180. These were tested at 700°C in a molten NaCl-KCl-MgCl2eutectic salt in static air and flowing argon. Electrochemical techniques were used to characterize the corrosion behavior of these materials. The morphology of the attack was determined using scanning electron microscopy coupled with energy dispersive spectroscopy (EDS). X-ray diffraction was used to characterize the corrosion products formed on the surface of the substrate. Based on these results, the candidate salt was deemed to be unsuitable for this application. In addition, all of the candidate alloys had unacceptably high corrosion rates.INTRODUCTIONSolar energy is a rapidly expanding alternative to fossil fuels that is predominantly harvested through the use of photovoltaics (PVs). The functionality of PVs is restricted to the periods when direct sunlight is available. One method of overcoming this constraint to energy generation is through the use of concentrated solar power (CSP). CSP is emerging as an attractive alternative to PVs because of the persistence in providing energy to the grid during periods when the sunlight is absent. This is facilitated by storing energy in a heat transfer fluid (HTF).Molten salts have been identified as ideal heat transfer fluids in CSP applications because they contain many desirable thermal properties, e.g., high heat capacities, stability over a wide range of temperatures, etc. The Andasol plant in Spain and the Solano plant in Arizona currently use nitrate mixtures as heat transfer fluids.1 Stainless steels and nickel-base alloys are the materials of choice for molten salt containment in many current CSP plants because they provide sufficient corrosion resistance when exposed to nitrate salts, the currently preferred HTF.2 Chloride mixtures are a potentially attractive alternative because they offer higher thermal stabilities and are more economically viable than nitrates. However, molten chloride salts are corrosive, and therefore, proper salt & containment material selection are essential.
Otsuka, N. (Corporate R&D Laboratories,Sumitomo Metal Industries, Ltd) | Nishiyama, Y. (Corporate R&D Laboratories,Sumitomo Metal Industries, Ltd) | Miyahara, O. (Special Tube Steel Works, Sumitomo Metal Industries, Ltd) | Matsuo, T. (Sumitomo Metal Industries, Ltd)
Pulvirenti, April L. (The Catholic University of America) | Needham, K.M. (The Catholic University of America) | Hadadi, A. Adel- (The Catholic University of America) | Barkatt, Aaron (The Catholic University of America) | Marks, C. (Dominion Engineering Inc.) | Gorman, Jeffrey A. (Dominion Engineering Inc.)