A Numerical Study on 2-D Flow and Heat Transfer in a Natural Gas Heater

2016 ◽  
Author(s):  
Yun Guo ◽  
Zhixiong Guo
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Natural Gas ◽  
Numerical Study ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Radiation Heat ◽  
Effective Measure ◽  
Heating And Cooling ◽  
Application Systems

The cylinder type natural gas heater with heat transfer medium is most widely used in gas application systems. But the conventional symmetrical arrangement of heat-exchange surfaces in cylinder is not conducive to the formation of an effective heat flow field. An effective measure of rotating the symmetrical layout structure at a certain angle is put forward creatively, which can optimize the overall heat transfer effect of the heater. The combined natural convection and radiation heat transfer model for both heating and cooling surfaces in the heat-exchanging cylinder is built. The finite volume method with unstructured body-fitted grids is employed. Analyses and comparisons of the flow conditions and temperature distributions of the cylindrical natural gas heater indifferent clockwise rotation angles (10°, 20°, 30°, 35°) are carried out. With increasing of the angle, the natural convection and radiation heat transfer will be correspondingly enhanced. When the angle exceeds than 30°, however, the natural convective circulation is destroyed instead. The numerical simulation shows the best rotation angle is 20∼30°.

Numerical Study on the Flow and Heat Transfer for the inside of the Cylinder Type Natural Gas Heater

2013 ◽  
Vol 860-863 ◽  
pp. 1441-1444
Author(s):  
Yun Guo ◽  
Zhi Qiang Huang ◽  
Shun Xin Yang
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Natural Gas ◽  
Numerical Study ◽  
Heating Surface ◽  
Gas Production ◽  
Transfer Model ◽  
Heat Transfer Medium ◽  
Heating And Cooling ◽  
Application Systems

The cylinder type natural gas heater is an indispensable piece of equipment in gas production, transmission, and application systems. According to the distinctive structure of the cylinder natural gas heater, the natural convection heat transfer model of both heating surface and cooling surface in the cylinder was built, the temperature and velocity field of the natural convection of the heat-transfer medium--ethylene glycol were numerically simulated. The simulation results show that the symmetrical arrangement of heating and cooling surfaces is not conducive to the formation of an effective heat flow field. Therefore, effective optimizing the layout of the heating and cooling surfaces is obviously a problem that must be solved, to help the heat-transfer medium form a well-organized flow and enhance the heat transfer.

scholarly journals Numerical Study of Convection and Radiation Heat Transfer in Pipe Cable

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Chen-Zhao Fu ◽  
Wen-Rong Si ◽  
Lei Quan ◽  
Jian Yang
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Study ◽  
Radiation Heat Transfer ◽  
Power Cable ◽  
Convection Heat ◽  
Radiation Heat ◽  
Cable System ◽  
Inner Surface ◽  
Convection Model

Pipe cable is considered as an important form for underground transmission line. The maximum electrical current (ampacity) of power cable system mostly depends on the cable conductor temperature. Therefore, accurate calculation of temperature distribution in the power cable system is quite important to extract the cable ampacity. In the present paper, the fluid flow and heat transfer characteristics in the pipe cable with alternating current were numerically studied by using commercial code COMSOL MULTIPHYSICS based on finite element method (FEM). The cable core loss and eddy current loss in the cable were coupled for the heat transfer simulation, and the difference of heat transfer performances with pure natural convection model and radiation-convection model was compared and analysed in detail. Meanwhile, for the radiation-convection model, the effects caused by radiant emissivity of cable surface and pipe inner surface, as well as the cable location in the pipe, were also discussed. Firstly, it is revealed that the radiation and natural convection heat flux on the cable surface would be of the same order of magnitude, and the radiation heat transfer on the cable surface should not be ignored. Otherwise, the cable ampacity would be underestimated. Secondly, it is found that the overall heat transfer rate on the cable surface increases as the cable surface emissivity increases, and this is more remarkable to the upper cable. While the effect caused by the radiant emissivity on the pipe inner surface would be relatively small. Furthermore, it is demonstrated that, as cable location in the pipe falls, the natural convection heat transfer would be enhanced. These results would be meaningful for the ampacity prediction and optimum design for the pipe cable.

Conjugate Heat Transfer From a Vertical Plate With Discrete Heat Sources Under Natural Convection

1989 ◽  
Vol 111 (4) ◽  
pp. 261-267 ◽  
Author(s):  
S. Lee ◽  
M. M. Yovanovich
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Conjugate Heat Transfer ◽  
Vertical Plate ◽  
Power Level ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Heat Sources ◽  
Radiation Heat ◽  
Discrete Heat Sources

A quasi-analytical conjugate heat transfer model is developed for a two dimensional vertical flat plate with discrete heat sources of arbitrary size and power level under natural convection. The plate is located in an extensive, quiescent fluid which is maintained at uniform temperature. The model consists of an approximate analytical boundary layer solution and a one dimensional numerical conduction analysis in which an allowance is made to account for radiation heat transfer. These fluid and solid solutions are coupled through an iterative procedure. A conjugate problem is solved when a converged temperature distribution is obtained at the plate-fluid interface, concurrently satisfying the thermal fields on both sides of the interface. Comparisons of the surface temperature variations obtained by using the present model are made with existing numerical and experimental data which were obtained for cases with two strip heat sources mounted flush with the surface of a vertical plate in air. The model is shown to be in good agreement. In addition, the convection and radiation heat flux variations are presented. The results illustrate the importance of radiation heat transfer for estimating surface temperatures of the plate.

scholarly journals Influence of Varying Pressure on Natural Convection and Radiation Heat Transfer in an Enclosure

PAMM ◽  
2005 ◽  
Vol 5 (1) ◽  
pp. 575-576 ◽  
Author(s):  
Jan Langebach ◽  
Stephan Senin ◽  
Christian Karcher
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Radiation Heat Transfer ◽  
Radiation Heat
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