A water-TiO2nanofluid with a weight fraction of 5% and an average particle size of 75 nm is used to investigate the effect of TiO2 nanoparticles on the crystallization and melting behaviors of deionized water by using...A water-TiO2nanofluid with a weight fraction of 5% and an average particle size of 75 nm is used to investigate the effect of TiO2 nanoparticles on the crystallization and melting behaviors of deionized water by using differential scanning calorimetry（DSC）at four different cooling rates,3,5,7,9 ℃/min.The DSC experimental results show that the water-TiO2 nanofluid has a lower supercooling degree and a faster crystallization rate than the deionized water.With the increase in the cooling rate,the influence of the TiO2 nanoparticles on the supercooling degree of the deionized water becomes greater,but on the crystallization rate it turns lower.During the melting process,compared with the deionized water,the water-TiO2 nanofluid has a lower melting temperature,a less latent heat and a higher melting rate.展开更多
An experimental study has been carried out to determine the partition coefficients of tungsten between aqueous fluids and granitic melts at 800℃ and 1.5kb with natural granite as the starting material,The effects of ...An experimental study has been carried out to determine the partition coefficients of tungsten between aqueous fluids and granitic melts at 800℃ and 1.5kb with natural granite as the starting material,The effects of the solution on the partition coefficients of tungsten show a wequence of P>co3^2->B>H2O.The effects are limited(generally KD<0.3)and the tungsten shows a preferential trend toward the melt over the aqueous fiuid.The value of KD increases with increasing concentration of phosphorus;the KD increases first and then reduces with the concentration of CO3^2-;when temperature decreases,the KD between the solution of CO3^2- and the silicate melt increases,and that between the solution of B4O7^2- and the silicate melt decreases.The partition coefficients of phosphorus and sodium between fluids and silicate melts have been calculated from the concentrations of the elements in the melts.The KD value for phosphorus is 0.38 and that for sodium is 0.56.Evidence shows that the elements tend to become richer and richer in the melts.展开更多
In this work, a thermodynamic model is developed for prediction of structure H hydrate formation. The model combines the Peng-Robinson equation of state for the vapor, liquid and aqueous phases with the extended Ng-Ro...In this work, a thermodynamic model is developed for prediction of structure H hydrate formation. The model combines the Peng-Robinson equation of state for the vapor, liquid and aqueous phases with the extended Ng-Robinson hydrate model for gas hydrate formation of all three structures. The parameters of 14 structure- H hydrate formers are determined based on the experimental data of structure-H hydrates in the literature. The expression of fugacity of water in the empty hydrate phase is correlated for calculating structure-H hydrate formation conditions in the absence of free water. The model is tested by predicting hydrate formation conditions of a number of structure-H hydrate forming systems which are in good agreement with the experimental data. The proposed model is also applied to the prediction of hydrate formation conditions for various reservoir fluids such as natural gas and gas condensate.展开更多
Measurement of two phase flow in porous medium for sequestration was carried out using high-resolution magnetic resonance imaging (MRI) technique. The porous medium was a packed bed of glass beads. Spin echo multi seq...Measurement of two phase flow in porous medium for sequestration was carried out using high-resolution magnetic resonance imaging (MRI) technique. The porous medium was a packed bed of glass beads. Spin echo multi sequence was used to measure the distribution of CO2 and water in the porous medium. The intensity images show that the fluid distribution is non-uniform due to its viscosity and pore structure of porous medium. The velocity distribution of fluids is calculated from the saturation of water and porosity of porous medium. The experimental results show that fluid velocities vary with time and position. The capillary dispersion rate donated the effects of capillary, which was largest at water saturations of 0.45. The displacement process is different between in BZ-02 and BZ-2. The final water residual saturation depends on permeability and porosity.展开更多
基金The National Natural Science Foundation of China(No.50876022)
文摘A water-TiO2nanofluid with a weight fraction of 5% and an average particle size of 75 nm is used to investigate the effect of TiO2 nanoparticles on the crystallization and melting behaviors of deionized water by using differential scanning calorimetry（DSC）at four different cooling rates,3,5,7,9 ℃/min.The DSC experimental results show that the water-TiO2 nanofluid has a lower supercooling degree and a faster crystallization rate than the deionized water.With the increase in the cooling rate,the influence of the TiO2 nanoparticles on the supercooling degree of the deionized water becomes greater,but on the crystallization rate it turns lower.During the melting process,compared with the deionized water,the water-TiO2 nanofluid has a lower melting temperature,a less latent heat and a higher melting rate.
文摘An experimental study has been carried out to determine the partition coefficients of tungsten between aqueous fluids and granitic melts at 800℃ and 1.5kb with natural granite as the starting material,The effects of the solution on the partition coefficients of tungsten show a wequence of P>co3^2->B>H2O.The effects are limited(generally KD<0.3)and the tungsten shows a preferential trend toward the melt over the aqueous fiuid.The value of KD increases with increasing concentration of phosphorus;the KD increases first and then reduces with the concentration of CO3^2-;when temperature decreases,the KD between the solution of CO3^2- and the silicate melt increases,and that between the solution of B4O7^2- and the silicate melt decreases.The partition coefficients of phosphorus and sodium between fluids and silicate melts have been calculated from the concentrations of the elements in the melts.The KD value for phosphorus is 0.38 and that for sodium is 0.56.Evidence shows that the elements tend to become richer and richer in the melts.
基金Supported by the National Natural Science Foundation of China (No. 20490207, No. 20176028, No. 90210020) and Huo Ying-dong Education Foundation (No. 81064)
文摘In this work, a thermodynamic model is developed for prediction of structure H hydrate formation. The model combines the Peng-Robinson equation of state for the vapor, liquid and aqueous phases with the extended Ng-Robinson hydrate model for gas hydrate formation of all three structures. The parameters of 14 structure- H hydrate formers are determined based on the experimental data of structure-H hydrates in the literature. The expression of fugacity of water in the empty hydrate phase is correlated for calculating structure-H hydrate formation conditions in the absence of free water. The model is tested by predicting hydrate formation conditions of a number of structure-H hydrate forming systems which are in good agreement with the experimental data. The proposed model is also applied to the prediction of hydrate formation conditions for various reservoir fluids such as natural gas and gas condensate.
基金Supported by the Major State Basic Research Development Program of China(2011CB707304)the National Natural Science Foundation of China(51006016,51006017,51106018,51106019)
文摘Measurement of two phase flow in porous medium for sequestration was carried out using high-resolution magnetic resonance imaging (MRI) technique. The porous medium was a packed bed of glass beads. Spin echo multi sequence was used to measure the distribution of CO2 and water in the porous medium. The intensity images show that the fluid distribution is non-uniform due to its viscosity and pore structure of porous medium. The velocity distribution of fluids is calculated from the saturation of water and porosity of porous medium. The experimental results show that fluid velocities vary with time and position. The capillary dispersion rate donated the effects of capillary, which was largest at water saturations of 0.45. The displacement process is different between in BZ-02 and BZ-2. The final water residual saturation depends on permeability and porosity.
