Heat transfer and combustion for a spiral flow in an ideal-displacement reactor

1991 ◽  
Vol 60 (2) ◽  
pp. 171-177 ◽  
Author(s):  
I. G. Dik ◽  
O. V. Matvienko

1976 ◽  
Vol 15 (6) ◽  
pp. 826-831
Author(s):  
V. S. Berman ◽  
Yu. P. Gupalo ◽  
A. V. Martirosov ◽  
Yu. S. Ryazantsev


1976 ◽  
Vol 31 (2) ◽  
pp. 900-903
Author(s):  
A. F. Koval'nogov ◽  
V. P. Ermachenko


2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Wei Du ◽  
Lei Luo ◽  
Songtao Wang ◽  
Jian Liu ◽  
Bengt Sunden

AbstractA numerical method was used to study the effect of the broken rib locations on the heat transfer and flow structure in the latticework duct with various rotational numbers. The latticework duct had eleven subchannels on both the pressure side and the suction side. The crossing angle for each subchannel was 45 deg. The numerical studies were conducted with five different broken rib locations and six rotational numbers (0–0.5). The Reynolds number was fixed as 44,000. The flow structure, wall shear stress, and Nusselt number distributions were analyzed. It was found that the upward spiral flow and helical flow dominated the flow structure in the latticework duct. In addition, the impingement region (at the beginning of the subchannel) induced by the upward spiral flow was responsible for the high Nusselt number and wall shear stress. After adoption of the broken rib in the latticework duct, the Nusselt number was increased by 6.12% on the pressure endwall surface and increased by 6.02% on the rib surface compared to the traditional latticework duct. As the rotational number was increased, the Nusselt number on the pressure endwall surface was decreased by up to 5.4%. However, the high rotational number enhanced the heat transfer on the suction side. The high rotational number also decreased the friction factor in the latticework duct. Furthermore, the overall thermal performance was increased by 12.12% after adoption of the broken ribs on both the turn region and the impingement region.





Author(s):  
Aleksey Bal'chugov ◽  
Mihail Vazhenin ◽  
Borislav Kustov

It has been experimentally established that the ideal displacement model adequately describes the heat transfer process in a horizontal heat exchange pipe cooled by atmospheric air



2014 ◽  
Vol 2014 (0) ◽  
pp. _A221-1_-_A221-2_
Author(s):  
Yuta Ichikura ◽  
Kazuya Kodani ◽  
Yuuki Tsukinari




2020 ◽  
Author(s):  
Yongchao Rao ◽  
Lijun Li ◽  
Shuli Wang ◽  
Shuhua Zhao ◽  
Shidong Zhou

Abstract The DPM model (discrete phase model) considering the motion of solid particles was used to simulate the complex spiral flow characteristics of hydrate in the pipe spinning up with long twisted band. The deposition and heat transfer characteristics of gas hydrate particles in the pipe spiral flow were studied. The velocity distribution, pressure drop distribution, heat transfer characteristics and particle settling characteristics of the flow field in the pipeline were investigated. The numerical results show that, compared with the straight flow of light pipe without twisted band, two obvious eddies are formed in the flow field under the spinning action of twisted band, and the velocities are maximum at the center of the eddies. Along the direction of the pipe, the two vortices move towards the pipe wall from near the twisted band, which can effectively carry the hydrate particles deposited on the pipe wall. With the same Reynolds number, the greater the twist ratio, the weaker the spiral strength, the smaller the tangential velocity of the spiral flow, and the smaller the pressure drop of the pipe. Therefore, the pressure loss can be reduced as much as possible while ensuring the spinning effect of the spiral flow. In a straight light pipe flow, the Nusser number is in a parabolic shape with the opening downwards. At the center of the pipe, the Nusser number gradually decreases towards the pipe wall at the maximum, and at the near wall, the attenuation gradient of Nu is large. For spiral flow, the curve presented by Nusserr number shows a trough at the center of the pipe and a peak at 1/2 of the pipe diameter. With the reduction of twist rate, the Nussel number becomes larger and larger. Therefore, the spiral flow can make the temperature distribution in the flow field in the pipeline more even, and prevent the large temperature difference resulting in the mass formation of hydrate particles in the pipeline wall. Spiral flow has a good carrying effect. Under the same working condition, the spiral flow carries hydrate particles at a distance about 3-4 times that of the straight flow.



Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 489
Author(s):  
Yongchao Rao ◽  
Lijun Li ◽  
Shuli Wang ◽  
Shuhua Zhao ◽  
Shidong Zhou

The natural gas hydrate plugging problems in the mixed pipeline are becoming more and more serious. The hydrate plugging has gradually become an important problem to ensure the safety of pipeline operation. The deposition and heat transfer characteristics of natural gas hydrate particles in the spiral flow pipeline have been studied. The DPM model (discrete phase model) was used to simulate the motion of solid particles, which was used to simulate the complex spiral flow characteristics of hydrate in the pipeline with a long twisted band. The deposition and heat transfer characteristics of gas hydrate particles in the spiral flow pipeline were studied. The velocity distribution, pressure drop distribution, heat transfer characteristics, and particle settling characteristics in the pipeline were investigated. The numerical results showed that compared with the straight flow without a long twisted band, two obvious eddies are formed in the flow field with a long twisted band, and the velocities are maximum at the center of the vortices. Along the direction of the pipeline, the two vortices move toward the pipe wall from near the twisted band, which can effectively carry the hydrate particles deposited on the wall. With the same Reynolds number, the twisted rate was greater, the spiral strength was weaker, the tangential velocity was smaller, and the pressure drop was smaller. Therefore, the pressure loss can be reduced as much as possible with effect of the spiral flow. In a straight light flow, the Nusselt number is in a parabolic shape with the opening downwards. At the center of the pipe, the Nusselt number gradually decreased toward the pipe wall at the maximum, and at the near wall, the attenuation gradient of the Nu number was large. For spiral flow, the curve presented by the Nusselt number was a trough at the center of the pipe and a peak at 1/2 of the pipe diameter. With the reduction of twist rate, the Nusselt number becomes larger. Therefore, the spiral flow can make the temperature distribution more even and prevent the large temperature difference, resulting in the mass formation of hydrate particles in the pipeline wall. Spiral flow has a good carrying effect. Under the same condition, the spiral flow carried hydrate particles at a distance about 3–4 times farther than that of the straight flow.



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