Parametric study of heat/mass transfer performance of seawater–air two‐phase counterflow in packing in seawater cooling towers

Heat Transfer ◽  
2022 ◽  
Author(s):  
Yang Yu ◽  
Xiao‐Ni Qi ◽  
Xiao‐Chen Hou ◽  
Xiao‐Hang Qu ◽  
Qian‐Jian Guo ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Parametric Study ◽  
Heat Mass Transfer ◽  
Transfer Performance ◽  
Cooling Towers ◽  
Two Phase

Influence of Blade Leading Edge Geometry on Turbine Endwall Heat(Mass) Transfer

2005 ◽  
Author(s):  
S. Han ◽  
R. J. Goldstein
Keyword(s):  
Mass Transfer ◽  
Heat Mass Transfer ◽  
Leading Edge ◽  
Local Heat ◽  
Secondary Flows ◽  
Transfer Performance ◽  
Turbine Cascade ◽  
Suction Surface ◽  
Naphthalene Sublimation Technique ◽  
Passage Vortex

The secondary flows, including passage and other vortices in a turbine cascade cause significant aerodynamic losses and thermal gradients. Leading-edge modification of the blade has drawn considerable attention as it has been shown to reduce the secondary flows. However, the heat transfer performance of a leading-edge modified blade has not been investigated thoroughly. Since a fillet at the leading edge blade is reported to reduce the aerodynamic loss significantly, the naphthalene sublimation technique with a fillet geometry is used to study local heat (mass) transfer performance in a simulated turbine cascade. The present paper compares Sherwood number distributions on an endwall with a simple blade and a similar blade having modified leading-edge by adding a fillet. With the modified blades, a horseshoe vortex is not observed and the passage vortex is delayed or not observed for different turbulence intensities. However, near the blade trailing edge the passage vortex has gained as much strength as with the simple blade for low turbulence intensity. Near the leading edge on the pressure and the suction surface, higher mass transfer regions are observed with the fillets. Apparently the corner vortices are intensified with the leading-edge modified blade.

Influence of Blade Leading Edge Geometry on Turbine Endwall Heat (Mass) Transfer

2005 ◽  
Vol 128 (4) ◽  
pp. 798-813 ◽  
Author(s):  
S. Han ◽  
R. J. Goldstein
Keyword(s):  
Mass Transfer ◽  
Heat Mass Transfer ◽  
Leading Edge ◽  
Local Heat ◽  
Secondary Flows ◽  
Transfer Performance ◽  
Turbine Cascade ◽  
Suction Surface ◽  
Naphthalene Sublimation Technique ◽  
Passage Vortex

The secondary flows, including passage and other vortices in a turbine cascade, cause significant aerodynamic losses and thermal gradients. Leading edge modification of the blade has drawn considerable attention as it has been shown to reduce the secondary flows. However, the heat transfer performance of a leading edge modified blade has not been investigated thoroughly. Since a fillet at the leading edge blade is reported to reduce the aerodynamic loss significantly, the naphthalene sublimation technique with a fillet geometry is used to study local heat (mass) transfer performance in a simulated turbine cascade. The present paper compares Sherwood number distributions on an endwall with a simple blade and a similar blade having a modified leading edge by adding a fillet. With the modified blades, a horseshoe vortex is not observed and the passage vortex is delayed or not observed for different turbulence intensities. However, near the blade trailing edge the passage vortex has gained as much strength as with the simple blade for low turbulence intensity. Near the leading edge on the pressure and the suction surface, higher mass transfer regions are observed with the fillets. Apparently the corner vortices are intensified with the leading edge modified blade.

scholarly journals Designed porous milli-scale reactors with enhanced interfacial mass transfer in two-phase flows

2017 ◽  
Vol 2 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Aditi Potdar ◽  
Lidia N. Protasova ◽  
Leen Thomassen ◽  
Simon Kuhn
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Packed Bed ◽  
Transfer Performance ◽  
Two Phase Flows ◽  
Two Phase ◽  
Reduced Pressure ◽  
Packed Bed Reactors ◽  
Interfacial Mass Transfer

Designed porous milli-scale reactors with enhanced mass transfer performance and reduced pressure drop compared to conventional packed bed reactors.

Augmented Heat Transfer for Angled Rib With Intersecting Rib in Rectangular Channels of Different Aspect Ratios

2014 ◽  
Author(s):  
Heeyoon Chung ◽  
Jun Su Park ◽  
Sehjin Park ◽  
Seok Min Choi ◽  
Hyung Hee Cho ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Aspect Ratio ◽  
Heat Mass Transfer ◽  
Transfer Performance ◽  
Aspect Ratios ◽  
Rectangular Channels ◽  
Naphthalene Sublimation ◽  
Sublimation Method ◽  
Channel Aspect Ratio

This study was an experimental investigation of the effect of an intersecting rib on heat/mass transfer performance in rectangular channels with angled ribs and different aspect ratios. In a rib-roughened channel with angled ribs, heat/mass transfer performance deteriorates as the channel aspect ratio increases, since the vortices induced by angled ribs diminish with increasing aspect ratio. A longitudinal rib that bisects the angled ribs is suggested to overcome this disadvantage. The heat transfer performance of angled rib configurations with a 60° attack angle were tested with and without an intersecting rib using naphthalene sublimation method. The channel aspect ratio is varied from 1 to 4. When the intersecting rib was present, additional vortices were generated at every point of intersection with the angled ribs. Thus the heat/mass transfer performance was significantly enhanced for all channel aspect ratios when an intersecting rib was added to an ordinary angled rib configuration.

scholarly journals Heat and mass transfer performance and exergy performance evaluation of seawater cooling tower considering different inlet parameters

2021 ◽  
pp. 312-312
Author(s):  
Yang Yu ◽  
Xiaoni Qi ◽  
Xiaochen Hou ◽  
Xiaohang Qu ◽  
Qianjian Guo ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Thermal Efficiency ◽  
Cooling Tower ◽  
Exergy Efficiency ◽  
Optimum Operating ◽  
Transfer Performance ◽  
Cooling Towers ◽  
Air Speed ◽  
Exergy Performance

Cooling towers are important components within recirculating cooling water systems. Due to a shortage of freshwater resources, seawater cooling towers are widely used both in manufacturing and everyday life. This paper researches the mechanical draft counterflow wet seawater cooling tower (MDCWSCT), and establishes and verifies a detailed thermal performance calculation model. Referring to the second law of thermodynamics, the heat and mass transfer performance and exergy performance of the seawater cooling tower were studied. The effects of salinity, inlet air speed, and air wet-bulb temperature on the cooling efficiency, thermal efficiency, and exergy efficiency were analyzed. The results show that compared to the air wet-bulb temperature, changes in air speed have more influence on cooling and thermal efficiency under the study conditions. Moreover, the air wet-bulb temperature is the significant parameter affecting exergy efficiency. With an increase in salinity, the cooling, thermal, and exergy efficiency are about 2.40-8.25 %, 1.06-3.09 %, and 2.47-7.73 % lower than that of freshwater, respectively, within an air speed of 3.1-3.6 m/s. With an increase in salinity, the cooling, thermal, and exergy efficiency are about 2.28-8.47 %, 1.03-3.37 %, and 2.44-7.99 % lower than that of freshwater, respectively, within an air wet-bulb temperature of 25-27 ?. Through the exergy analysis of the seawater cooling tower, it is obvious that the heat and mass transfer performance and exergy performance can be improved by selecting the optimum operating conditions and appropriate packing specifications.

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