In this study,enhanced kinetics of methane hydrate formation in the sodium dodecyl sulfate(SDS)solution with different concentrations of suspended graphite nanoparticles(GNPs)were investigated at 6.1-9.0 MPa and 274.1...In this study,enhanced kinetics of methane hydrate formation in the sodium dodecyl sulfate(SDS)solution with different concentrations of suspended graphite nanoparticles(GNPs)were investigated at 6.1-9.0 MPa and 274.15 K.The GNPs with rough surfaces and excellent thermal conductivity not only provided a considerable number of microsites for hydrate nucleation but also facilitated the fast hydrate heat transfer in the suspension system.At a relatively low pressure of 6.1 MPa,the suspension with 0.4 wt%of GNPs exhibited the minimum induction time of 22 min and maximum methane uptake of 126.1 cm3·cm-3.However,the methane storage performances of the suspensions with higher and lower concentrations of GNPs were not satisfactory.At the applied pressure,the temperature increase arising from the hydrate heat in the suspension system with the optimized concentration(0.4 wt%)of GNPs was more significant than that in the traditional SDS solution.Furthermore,compared with those of the system without GNPs,enhanced hydration rate and storage capacity were achieved in the suspensions with GNPs,and the storage capacities were increased by 3.9%-17.0%.The promotion effect of GNPs on gas hydrate formation at low pressure is much more obvious than that at high pressure.展开更多
By simplifying the characters in the air reverse circulation bit interior fluid field, the authors used air dynamics and fluid mechanics to calculate the air distribution in the bit and obtained an equation of flow di...By simplifying the characters in the air reverse circulation bit interior fluid field, the authors used air dynamics and fluid mechanics to calculate the air distribution in the bit and obtained an equation of flow distribution with a unique resolution. This study will provide help for making certain the bit parameters of the bit structure effectively and study the air reverse circulation bit interior fluid field character deeply.展开更多
By using fluent fluid engineer emulator software to simulate negative pressure formed inside the injector added in the reverse-circulation sampling drilling bit, at six angles of 15, 30, 45, 60, 75 and 90 degrees. The...By using fluent fluid engineer emulator software to simulate negative pressure formed inside the injector added in the reverse-circulation sampling drilling bit, at six angles of 15, 30, 45, 60, 75 and 90 degrees. The pressure distributing nephogram and the corresponding numerical value gotten compared with the experiment data received by an injector with 6 angles designed by emulation the conclusion. It has been found that the two values are coincident essentially. The article shows that using emulator technology to design optimizely is credible and simple. The cost is low and the design cycle is short compared with the method through experience and test.展开更多
基金supported by the National Natural Science Foundation of China(grant numbers 51606125,51802190,21978171,51876130,51674240)the Innovation Program of Shanghai Municipal Education Commission(grant number 13ZZ117)。
文摘In this study,enhanced kinetics of methane hydrate formation in the sodium dodecyl sulfate(SDS)solution with different concentrations of suspended graphite nanoparticles(GNPs)were investigated at 6.1-9.0 MPa and 274.15 K.The GNPs with rough surfaces and excellent thermal conductivity not only provided a considerable number of microsites for hydrate nucleation but also facilitated the fast hydrate heat transfer in the suspension system.At a relatively low pressure of 6.1 MPa,the suspension with 0.4 wt%of GNPs exhibited the minimum induction time of 22 min and maximum methane uptake of 126.1 cm3·cm-3.However,the methane storage performances of the suspensions with higher and lower concentrations of GNPs were not satisfactory.At the applied pressure,the temperature increase arising from the hydrate heat in the suspension system with the optimized concentration(0.4 wt%)of GNPs was more significant than that in the traditional SDS solution.Furthermore,compared with those of the system without GNPs,enhanced hydration rate and storage capacity were achieved in the suspensions with GNPs,and the storage capacities were increased by 3.9%-17.0%.The promotion effect of GNPs on gas hydrate formation at low pressure is much more obvious than that at high pressure.
基金Jilin Province Science and Technology Development Leading Project(No.200405033)
文摘By simplifying the characters in the air reverse circulation bit interior fluid field, the authors used air dynamics and fluid mechanics to calculate the air distribution in the bit and obtained an equation of flow distribution with a unique resolution. This study will provide help for making certain the bit parameters of the bit structure effectively and study the air reverse circulation bit interior fluid field character deeply.
基金Project of Science & Technology Development Guidance of Jilin Province (No.200405033)
文摘By using fluent fluid engineer emulator software to simulate negative pressure formed inside the injector added in the reverse-circulation sampling drilling bit, at six angles of 15, 30, 45, 60, 75 and 90 degrees. The pressure distributing nephogram and the corresponding numerical value gotten compared with the experiment data received by an injector with 6 angles designed by emulation the conclusion. It has been found that the two values are coincident essentially. The article shows that using emulator technology to design optimizely is credible and simple. The cost is low and the design cycle is short compared with the method through experience and test.
