Abstract:In 1997, the International Association for the Properties of Water and Steam (IAPWS) adopted a new formulation for the thermodynamic properties of water and steam for industrial use. This new formulation, called IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam (IAPWS-IF97), replaces the previous industrial formulation, IFC-67, that had formed the basis for power-plant calculations and other applications in energy engineering since the late 1960’s. IAPWS-IF97 improves signif… Show more
“…At high pressure (80 bar) a single peak at 153.5°C is observed. As expected, water boiling peak disappeared (at 80 bar pressure, water boiling point is 294.98°C [49]) and the remaining peak refers to the PA12 block melting. This peak shifted down by 17.5°C due to cryoscopy corresponding to the melting of a single phase made of water and PA12 blocks.…”
Section: Analysis Of Peba-water Solubilitymentioning
Abstract. Polyether-block-amide (PEBA) /clay nanocomposites were prepared water-assisted by twin-screw extrusion. Both organomodified and pristine (i.e. purified but non-modified) montmorillonite clays were used. A high-pressure differential scanning calorimetry analysis carried out in the processing conditions demonstrated that PEBA/water blend exhibits some miscibility and that amide blocks and water behave as a single phase. In addition to a significant decrease of the melting temperature, water injected into the melt plays a key role among the filler dispersion and prevents the matrix from degradation during melt-extrusion. This process enables the compounding of pristine clay-based nanocomposites whose dispersion state is high enough for the resulting mechanical performances in tension to be at least equivalent to what is reached with organomodified clay. Effects of the nanofiller dispersion onto the macromolecules' mobility are detailed and fracture mechanisms are identified for the various structures.
“…At high pressure (80 bar) a single peak at 153.5°C is observed. As expected, water boiling peak disappeared (at 80 bar pressure, water boiling point is 294.98°C [49]) and the remaining peak refers to the PA12 block melting. This peak shifted down by 17.5°C due to cryoscopy corresponding to the melting of a single phase made of water and PA12 blocks.…”
Section: Analysis Of Peba-water Solubilitymentioning
Abstract. Polyether-block-amide (PEBA) /clay nanocomposites were prepared water-assisted by twin-screw extrusion. Both organomodified and pristine (i.e. purified but non-modified) montmorillonite clays were used. A high-pressure differential scanning calorimetry analysis carried out in the processing conditions demonstrated that PEBA/water blend exhibits some miscibility and that amide blocks and water behave as a single phase. In addition to a significant decrease of the melting temperature, water injected into the melt plays a key role among the filler dispersion and prevents the matrix from degradation during melt-extrusion. This process enables the compounding of pristine clay-based nanocomposites whose dispersion state is high enough for the resulting mechanical performances in tension to be at least equivalent to what is reached with organomodified clay. Effects of the nanofiller dispersion onto the macromolecules' mobility are detailed and fracture mechanisms are identified for the various structures.
“…However, as the relationship between the state quantities is very complex and the assumption of an ideal gas cannot be applied, an approximate EOS does not have a high enough accuracy for the state quantities calculation (O(10 À1 )). Thus, we used a look-up table based on IAPWS-IF97 13) for the calculation of state quantities. In this model, density ( ) and internal energy ("), which are calculated from N-S equations, are assigned as independent variables in the look-up table, and state quanti- Figure 10 shows the applicable range of the look-up table for the MATIS-SC code.…”
The boiling water reactor (BWR-3) steam dryer in the Quad Cities (QC) Unit 2 Nuclear Power Plant was damaged by high-cycle fatigue due to acoustic-induced vibration. The cause of the dryer failure was considered as flow-induced acoustic resonance at the stub pipes of the safety relief valve (SRV) in the main steam lines (MSLs). The acoustic resonance was considered to be generated by the interaction between the sound field and an unstable shear layer across the closed side branches of SRVs. We have started a research program on BWR steam dryers to develop methods of evaluating the loading. Moreover, it is necessary to evaluate the dryer integrity of BWR-5 plants, which are the main type of BWR in Japan.In the present study, we conducted 1/10-scale BWR model tests and analysis to investigate the flowinduced acoustic resonance and acoustic characteristics in MSLs. The test apparatus consisted of a steam dryer, a steam dome, and 4 MSLs with 20 SRV stub pipes. Computational fluid dynamics (CFD) analysis was conducted to evaluate the acoustic source in MSLs. Finite element method (FEM) was applied to calculate the three-dimensional wave equations for acoustic analysis. We demonstrated that large fluctuating pressure occurred in the high-and low-frequency regions. The high-frequency fluctuating pressure was generated by the flow-induced acoustic resonance in the SRV stub pipes. We evaluated the acoustic source (that is, the fluctuating pressure) in MSLs by unsteady CFD calculations, and we evaluated the pressure propagation by acoustic analysis. These results were verified by comparison with the results of scale-model tests, and they showed good agreement with the experimental results. The effects of the difference between the properties of air and steam were numerically investigated, and it was found that the effects on the acoustic resonance in the SRV stub pipes were not significant.
“…Equations for dynamic viscosity correlations for NaCl solutions 22 include dynamic viscosity data for pure water which were adopted from Cooper and Dooley. 23 Water density data needed for the evaluation of water viscosity were obtained from Wagner et al 24 Combined standard uncertainties in temperature and pressure measurements evaluated earlier in Sec. III B (see Table III) were used to calculate the effect of pressure and temperature variation on dynamic viscosity for NaCl solutions at experimental conditions of 2.00 MPa and 298.15 K. Variation of pressure within its CSU resulted in negligible viscosity variation of 5.77 × 10 −3 μPa×s or 6.19 × 10 −4 %.…”
Using the law of propagation of uncertainties we show how equipment- and measurement-related uncertainties contribute to the overall combined standard uncertainties (CSU) in filter permeability and in modelling the results for polystyrene latex microspheres filtration through a borosilicate glass filter at various injection velocities. Standard uncertainties in dynamic viscosity and volumetric flowrate of microspheres suspension have the greatest influence on the overall CSU in filter permeability which excellently agrees with results obtained from Monte Carlo simulations. Two model parameters “maximum critical retention concentration” and “minimum injection velocity” and their uncertainties were calculated by fitting two quadratic mathematical models to the experimental data using a weighted least squares approximation. Uncertainty in the internal cake porosity has the highest impact on modelling uncertainties in critical retention concentration. The model with the internal cake porosity reproduces experimental “critical retention concentration vs velocity”-data better than the second model which contains the total electrostatic force whose value and uncertainty have not been reliably calculated due to the lack of experimental dielectric data.
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