CFD Optimization of Gas Inlet Configuration for 100kW Microturbine Recuperator

2006 ◽  
Author(s):  
D. J. Zhang ◽  
Q. W. Wang ◽  
M. Zeng ◽  
L. Q. Luo ◽  
F. Wu ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Numerical Study ◽  
Cone Angle ◽  
Gas Pressure ◽  
Gas Pipeline ◽  
Worst Case ◽  
System A ◽  
Cavity Configuration ◽  
Gas Cavity ◽  
Cfd Optimization

Compact and efficient recuperator is an important component of a microturbine system. To ascertain the optimum gas cavity configuration of the recuperator in a 100kW-microturbine system, a numerical study of flow performance has been done. The main parameters to change in different cases are cone angle of the gas pipeline, α and depth of the pipeline in the gas cavity, L. By comparing the gas pressure drop, Δp and the gas outlets velocity nonuniformity, Su, we found that the case with α = 5° and L = 370mm is the best configuration. Comparing with the worst case, it may greatly decrease the velocity nonuniformity by 73.3% while the corresponding pressure drop increases only 8%.

OUTDOOR TESTS OF A TOWED BOAT MODEL WITH FUEL COMBUSTION IN A BOTTOM CAVITY

2020 ◽  
Author(s):  
S. M. FROLOV ◽  
◽  
S. V. Platonov ◽  
K. A. AVDEEV ◽  
V. S. AKSENOV ◽  
...  
Keyword(s):  
Drag Force ◽  
Direct Contact ◽  
Propulsion System ◽  
Hydrodynamic Drag ◽  
Atmospheric Air ◽  
System A ◽  
Bottom Cavity ◽  
Gas Cavity ◽  
System Power ◽  
Gas Supply

To reduce the hydrodynamic drag force to the movement of the boat, an artificial gas cavity is organized under its bottom. Such a cavity partially insulates the bottom from direct contact with water and provides “gas lubrication” by means of forced supply of atmospheric air or exhaust gases from the main propulsion system. A proper longitudinal and transverse shaping of the gas cavity can significantly (by 20%-30%) reduce the hydrodynamic drag of the boat at low (less than 3%) consumption of the propulsion system power for gas supply.

scholarly journals Numerical Study of Thermal-Hydraulic Performance of a New Spiral Z-Type PCHE for Supercritical CO2 Brayton Cycle

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4417
Author(s):  
Tingting Xu ◽  
Hongxia Zhao ◽  
Miao Wang ◽  
Jianhui Qi
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Pressure Loss ◽  
Numerical Study ◽  
Hydraulic Performance ◽  
Optimal Structure ◽  
Original Structure ◽  
Brayton Cycle ◽  
Compact Structure ◽  
Spiral Angle

Printed circuit heat exchangers (PCHEs) have the characteristics of high temperature and high pressure resistance, as well as compact structure, so they are widely used in the supercritical carbon dioxide (S-CO2) Brayton cycle. In order to fully study the heat transfer process of the Z-type PCHE, a numerical model of traditional Z-type PCHE was established and the accuracy of the model was verified. On this basis, a new type of spiral PCHE (S-ZPCHE) is proposed in this paper. The segmental design method was used to compare the pressure changes under 5 different spiral angles, and it was found that increasing the spiral angle θ of the spiral structure will reduce the pressure drop of the fluid. The effects of different spiral angles on the thermal-hydraulic performance of S-ZPCHE were compared. The results show that the pressure loss of fluid is greatly reduced, while the heat transfer performance is slightly reduced, and it was concluded that the spiral angle of 20° is optimal. The local fluid flow states of the original structure and the optimal structure were compared to analyze the reason for the pressure drop reduction effect of the optimal structure. Finally, the performance of the optimal structure was analyzed under variable working conditions. The results show that the effect of reducing pressure loss of the new S-ZPCHE is more obvious in the low Reynolds number region.

Experimental measurements of gas pressure drop of packed pebble beds

2020 ◽  
Vol 160 ◽  
pp. 111836
Author(s):  
Maulik Panchal ◽  
Abhishek Saraswat ◽  
Paritosh Chaudhuri
Keyword(s):  
Pressure Drop ◽  
Gas Pressure ◽  
Experimental Measurements

scholarly journals Numerical study on pressure drop factor in the vent-cap of CDQ shaft

2008 ◽  
Vol 17 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Bo Song ◽  
Yanhui Feng ◽  
Xinxin Zhang
Keyword(s):  
Pressure Drop ◽  
Numerical Study

Applicability of thermal response tests in designing standing column well system: A numerical study

Energy ◽  
2016 ◽  
Vol 109 ◽  
pp. 679-693 ◽  
Author(s):  
Jun-Seo Jeon ◽  
Seung-Rae Lee ◽  
Woo-Jin Kim
Keyword(s):  
Numerical Study ◽  
Thermal Response ◽  
System A

Understanding Carbon Dioxide Transfer in Direct Methanol Fuel Cells Using a Pore-Scale Model

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Nathaniel Metzger ◽  
Archana Sekar ◽  
Jun Li ◽  
Xianglin Li
Keyword(s):  
Carbon Dioxide ◽  
Pressure Drop ◽  
Gas Flow ◽  
Direct Methanol Fuel Cells ◽  
Gas Pressure ◽  
Mass Transfer Resistance ◽  
Transfer Resistance ◽  
Cell Components ◽  
Direct Methanol ◽  
Methanol Fuel Cells

Abstract The gas flow of carbon dioxide from the catalyst layer (CL) through the microporous layer (MPL) and gas diffusion layer (GDL) has great impacts on the water and fuel management in direct methanol fuel cells (DMFCs). This work has developed a liquid–vapor two-phase model considering the counter flow of carbon dioxide gas, methanol, and water liquid solution in porous electrodes of DMFC. The model simulation includes the capillary pressure as well as the pressure drop due to flow resistance through the fuel cell components. The pressure drop of carbon dioxide flow is found to be about two to three orders of magnitude higher than the pressure drop of the liquid flow. The big difference between liquid and gas pressure drops can be explained by two reasons: volume flowrate of gas is three orders of magnitude higher than that of liquid; only a small fraction of pores (<5%) in hydrophilic fuel cell components are available for gas flow. Model results indicate that the gas pressure and the mass transfer resistance of liquid and gas are more sensitive to the pore size distribution than the thickness of porous components. To buildup high gas pressure and high mass transfer resistance of liquid, the MPL and CL should avoid micro-cracks during manufacture. Distributions of pore size and wettability of the GDL and MPL have been designed to reduce the methanol crossover and improve fuel efficiency. The model results provide design guidance to obtain superior DMFC performance using highly concentrated methanol solutions or even pure methanol.

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