Experimental study of ammonia flow boiling in a vertical tube bundle: Part 3 – Enhanced dimple tube with 2/3rd height solid round PVC nonconductive rod

2021 ◽  
Author(s):  
Zahid Ayub ◽  
Ahmad Abbas ◽  
Tauseef Ismail ◽  
Adnan Ayub ◽  
Wei Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
Tube Bundle ◽  
Flow Boiling ◽  
Vertical Tube

Experimental study of ammonia flow boiling in a vertical tube bundle: Part 1 – Enhanced dimple tube

2021 ◽  
Author(s):  
Ahmad Abbas ◽  
Zahid H. Ayub ◽  
Tauseef Ismail ◽  
Adnan H. Ayub ◽  
Wei Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
Tube Bundle ◽  
Flow Boiling ◽  
Vertical Tube

Experimental Investigation on Natural Circulation in a Thermosyphon Reboiler

2010 ◽  
Author(s):  
Xing Luo ◽  
Yanming Gao ◽  
Stephan Kabelac
Keyword(s):  
Heat Transfer ◽  
Tube Bundle ◽  
Flow Boiling ◽  
Natural Circulation ◽  
Liquid Product ◽  
Pilot Scale ◽  
Vertical Tube ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Set Up

Thermosyphon reboilers are widely used in refineries, petrochemical industries and other chemical processes. The liquid product stream coming from the bottom of the vapor-liquid separator is heated in an evaporator consisting of a vertical tube or tube bundle. When the evaporation occurs, the specific volume of the two-phase fluid increases. The upward buoyancy force caused by the density difference between the evaporator and down-flow pipe drives the fluid flowing through the evaporator in to the separator and forms a natural circulation. The experiments were conducted in a pilot scale thermosyphon system in which the evaporator consists of 7 steel tubes (outside diameter 30 mm, wall thickness 2 mm, length 4 m). A mathematical model was set up to simulate the heat transfer and pressure drop, in which empirical equations from literature were used. With the help of the simulation, the flow boiling heat transfer coefficients inside the tubes can be evaluated from a few measured local wall temperatures.

Experimental study of the subcooled flow boiling heat transfer of magnetic nanofluid in a vertical tube under magnetic field

2019 ◽  
Vol 140 (6) ◽  
pp. 2805-2816 ◽  
Author(s):  
Sajjad Ahangar Zonouzi ◽  
Rahmatollah Khodabandeh ◽  
Habibollah Safarzadeh ◽  
Habib Aminfar ◽  
Mousa Mohammadpourfard ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Experimental Study ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
Vertical Tube ◽  
Subcooled Flow Boiling ◽  
Magnetic Nanofluid ◽  
Subcooled Flow ◽  
Flow Boiling Heat Transfer

Heat Transfer Characteristics of Passive Condensers for Reactor Containment Cooling

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Shripad T. Revankar
Keyword(s):  
Heat Transfer ◽  
Turbulent Mixing ◽  
Tube Bundle ◽  
Flow Boiling ◽  
Heat Removal ◽  
Theoretical Models ◽  
Outer Wall ◽  
Vertical Tube ◽  
Condensation Heat Transfer ◽  
Single Tube

Passive condensers that are based on gravitational force do not require pumps or blowers to move fluid and, hence, are considered as safety measures in nuclear power plant containment cooling. In this paper vertical tube passive condensers with the tube inside condensation and cooled by a secondary pool of water are discussed as applied to reactor containment heat removal system. Series of experiments were carried out on scaled separate effects test facilities with vertical single tube and four tube bundle condensers. The results of experimental data on the rate of condensation heat transfer, the effects of noncondensable, and parametric effects, such as pressure, tube diameters and lengths, obtained from single tube and tube bundle passive condenser are presented. The data on the tube bundle indicated larger condensation heat transfer due to enhanced heat transfer in the secondary cooling. For tube bundle condensation, the turbulent mixing on the secondary pool side decreases the temperature difference between pool water and condenser tube outer wall, causing an increase in secondary heat transfer. Theoretical models on tube condensation based on heat and mass analogy and boundary layer models were developed. The data were compared with theoretical models and good agreement was observed between theoretical predictions and single tube condensation heat transfer data. For the tube bundle condenser, the theoretical model agreed with data when the secondary side enhancement in heat transfer due to turbulent mixing in the flow boiling was included. Practical heat transfer correlations are presented using available data on passive condensers for reactor application.

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