http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Li Wang,Xuejing Zhang,JunHu Yang,Chong Ma,Wei Han,Yubing Gong 한국유체기계학회 2023 International journal of fluid machinery and syste Vol.16 No.2
When GVF in the inlet of the oil-gas mixed transmission twin-screw pump is high, the temperature difference between the inlet and outlet of the screw pump will rise significantly, and rotor expansion jam will occur. To prevent the expansion jam caused by the overheating of the screw pump, the cooling water jacket is designed for gas-liquid mixed screw pump with high GVF to continuously cool. Using the theory of fluid-structure interaction heat transfer, the cooling effect of the cooling water jacket of the equal pitch screw pump and the variable pitch screw pump is numerically calculated, and after comparison with the experiment, it finds that the maximum deviation of the outlet temperature of the variable pitch screw pump does not exceed 4K and the average deviation is about 6 %. When GVF is 96%, the calculation of the cooling water cavity shows that the average temperature drop of the liner after the cooling of the equal pitch screw pump and the variable pitch screw pump is about 4K and 3K, respectively. When GVF rises from 90% to 99%, the average temperature drop is about 3.5K. Cooling water jacket has obvious cooling effect on screw pump with high GVF.
Deyi Zhang,Mei Han,Yubing Li,Bing Wang,Yi Wang,Kunjie Wang,Huixia Feng 한국탄소학회 2017 Carbon Letters Vol.23 No.-
This paper introduces a nitrogen-doped ordered mesoporous carbon (NOMC) derived from glucosamine with hybrid capacitive behaviors, achieved by successfully combining electrical double-layer capacitance with pseudo-capacitance behaviors. The nitrogen doping content of the fabricated NOMC reached 7.4 at% while its specific surface area (SBET) and total pore volume reached 778 m2 g?1 and 1.17 cm3 g?1, respectively. A dual mesoporous structure with small mesopores centered at 3.6 nm and large mesopores centered at 9.9 nm was observed. The specific capacitance of the reported materials reached up to 328 F g?1, which was 2.1 times higher than that of pristine CMK-3. The capacitance retention rate was found to be higher than 87.9% after 1000 charge/discharge cycles. The supplementary pseudocapacitance as well as the enhanced wettability and conductivity due to the incorporation of nitrogen heteroatoms within the carbon matrixes were found to be responsible for the excellent capacitive performance of the reported NOMC materials.
Xuejing Zhang,Chong Ma,Li Wang,Xiaolin Huang,Wei Han,Yubing Gong 한국유체기계학회 2023 International journal of fluid machinery and syste Vol.16 No.1
The existing methods for studying the dynamics, thermodynamics and deformation characteristics of screw pumps do not consider the coupling effect of multi field interaction, which deviates from the actual working conditions. Based on SolidWorks and ANSYS software, a three-dimensional finite element model of a lead of conventional single screw pump is established in this paper. The influence of different gas(GVF) volume fraction on the temperature, pressure, deformation, leakage and volumetric efficiency of screw pump was studied by using the fluid-thermal-solid coupling method. The numerical simulation results of volumetric efficiency changing with the inlet and outlet pressure difference under pure liquid condition were verified by the published literature experimental data, and the optimal installation interference value was proposed. The results show that the GVF has an important influence on the comprehensive deformation of the rotor and pump bushing and the volumetric efficiency of the pump; the comprehensive deformation value of the rotor increases gradually from the inlet to the outlet, and increases gradually with the increase of the GVF; with the increase of GVF, the comprehensive deformation value of stator first decreases gradually, and then increases sharply; with the increase of GVF, the leakage first decreases slowly, then increases rapidly, and the volumetric efficiency first increases slowly, then decreases rapidly; the numerical simulation results are in good agreement with the experimental values, and the average deviation is less than 7%.