The vapor-liquid ejector is a simply flow device and driven by thermal energy. In this paper, a modified mathematical model of the vapor-liquid ejector is proposed, and the validation shows good agreements with the ex...The vapor-liquid ejector is a simply flow device and driven by thermal energy. In this paper, a modified mathematical model of the vapor-liquid ejector is proposed, and the validation shows good agreements with the experimental data. A study is carried out with six organic working fluids, namely R1233 zd(E), R1336 mzz(Z), R236 ea, R245 ca, R245 fa and R365 mfc. The influences of the entrainment ratio, the area ratio, the superheating at the vapor nozzle inlet, the subcooling at the liquid nozzle inlet, and the pressures at these inlets on the pressure lifting are parametrically investigated. An increase in the subcooling leads to the great increasing of pressure lifting and the superheating has slight effect on the pressure lifting, whereas others have the opposite tendency. The studies of the pressures and temperatures at the typical locations inside the vapor-liquid ejector are further conducted by using R1336 mzz(Z). The results show that the above parameters have great influence on these pressures and temperatures inside except that the pressures are insignificantly impacted by the superheating, and the temperatures are negligibly affected by the area ratio. R1336 mzz(Z) is recommended as a good working fluid for the vapor-liquid ejector.展开更多
Swelling clays are found extensively in various parts of the world, and sodium-montmorillonite(NaMMT) is the main constituent of an expansive clay mineral. In this work, the swelling behavior of NaMMT clay with a wide...Swelling clays are found extensively in various parts of the world, and sodium-montmorillonite(NaMMT) is the main constituent of an expansive clay mineral. In this work, the swelling behavior of NaMMT clay with a wide range of organic fluids, high polar through low polar fluids, is studied using a combination of Fourier transform infrared(FTIR) technique and molecular dynamics(MD) simulations.The construction of the representative clayefluid models is carried out, and the nature of nonbonded interactions between clay and fluids is studied using MD. Our FTIR and MD simulations results suggest the significant nonbonded interactions between Na-MMT clay and polar fluids, such as formamide and water. The nonbonded interactions of Na-MMT with methanol and acetone are significantly less than those in Na-MMT with polar fluids. The interactions of the fluids with various entities of the clay such as Sie O, Fee OH, Mge OH, and Ale OH captured via the spectroscopy experiments and modeling provide a finer understanding of the interactions and their contributions to swelling. The MD simulations are able to capture the band shifts observed in the spectra obtained in the spectroscopy experiments. This work also captures the conformations of interlayer sodium ions with formamide, water, methanol, and acetone during swelling. These nonbonded interactions provide insight into the molecular mechanism that the polarity of fluids plays an important role in the initiation of interlayer swelling, alteration in the orientations, and evolution of microstructure of swelling clays at the molecular scale.展开更多
Additives which can significantly enhance the nucleate pool boiling of acetone and Freons have beenfound in experiments.The boiling heat transfer coefficients of the working fluids can increase by 3 to 5 timeswith tra...Additives which can significantly enhance the nucleate pool boiling of acetone and Freons have beenfound in experiments.The boiling heat transfer coefficients of the working fluids can increase by 3 to 5 timeswith trace amount additives.The mechanism of enhancing the boiling of the organic fluids with additives hasbeen investigated.展开更多
基金supported by the National Natural Science Foundation of China(51706047)Guangdong Special Funding for Applied Technology R&D(2016B020243010)Foshan Science&Technology Innovation Project(2016AG101232)
文摘The vapor-liquid ejector is a simply flow device and driven by thermal energy. In this paper, a modified mathematical model of the vapor-liquid ejector is proposed, and the validation shows good agreements with the experimental data. A study is carried out with six organic working fluids, namely R1233 zd(E), R1336 mzz(Z), R236 ea, R245 ca, R245 fa and R365 mfc. The influences of the entrainment ratio, the area ratio, the superheating at the vapor nozzle inlet, the subcooling at the liquid nozzle inlet, and the pressures at these inlets on the pressure lifting are parametrically investigated. An increase in the subcooling leads to the great increasing of pressure lifting and the superheating has slight effect on the pressure lifting, whereas others have the opposite tendency. The studies of the pressures and temperatures at the typical locations inside the vapor-liquid ejector are further conducted by using R1336 mzz(Z). The results show that the above parameters have great influence on these pressures and temperatures inside except that the pressures are insignificantly impacted by the superheating, and the temperatures are negligibly affected by the area ratio. R1336 mzz(Z) is recommended as a good working fluid for the vapor-liquid ejector.
基金the support of USDoT,Mountain Plains Consortium,UGPTI under grant No.#69A3551747108
文摘Swelling clays are found extensively in various parts of the world, and sodium-montmorillonite(NaMMT) is the main constituent of an expansive clay mineral. In this work, the swelling behavior of NaMMT clay with a wide range of organic fluids, high polar through low polar fluids, is studied using a combination of Fourier transform infrared(FTIR) technique and molecular dynamics(MD) simulations.The construction of the representative clayefluid models is carried out, and the nature of nonbonded interactions between clay and fluids is studied using MD. Our FTIR and MD simulations results suggest the significant nonbonded interactions between Na-MMT clay and polar fluids, such as formamide and water. The nonbonded interactions of Na-MMT with methanol and acetone are significantly less than those in Na-MMT with polar fluids. The interactions of the fluids with various entities of the clay such as Sie O, Fee OH, Mge OH, and Ale OH captured via the spectroscopy experiments and modeling provide a finer understanding of the interactions and their contributions to swelling. The MD simulations are able to capture the band shifts observed in the spectra obtained in the spectroscopy experiments. This work also captures the conformations of interlayer sodium ions with formamide, water, methanol, and acetone during swelling. These nonbonded interactions provide insight into the molecular mechanism that the polarity of fluids plays an important role in the initiation of interlayer swelling, alteration in the orientations, and evolution of microstructure of swelling clays at the molecular scale.
文摘Additives which can significantly enhance the nucleate pool boiling of acetone and Freons have beenfound in experiments.The boiling heat transfer coefficients of the working fluids can increase by 3 to 5 timeswith trace amount additives.The mechanism of enhancing the boiling of the organic fluids with additives hasbeen investigated.
