Heat transfer and energy analysis of a pusher type reheating furnace using oxygen enhanced air for combustion

In this work, the development of a mathematical heat transfer model for a walking-beam type reheating furnace is described and preliminary model predictions are presented. The model can predict the heat flux distribution within the furnace and the temperature distribution in the slab throughout the reheating furnace process by considering the heat exchange between the slab and its surroundings, including the radiant heat transfer among the slabs, the skids, the hot combustion gases and the furnace wall as well as the gas convection heat transfer in the furnace. In addition, present model is designed to be able to predict the formation and growth of the scale layer on the slab in order to investigate its effect on the slab heating. A comparison is made between the predictions of the present model and the data from an in situ measurement in the furnace, and a reasonable agreement is found. The results of the present simulation show that the effect of the scale layer on the slab heating is considerable.

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Effect of Geometric Configuration and Back Plate Addition in Minichannel Solar Collectors

Volume 6A: Energy ◽

10.1115/imece2018-87852 ◽

2018 ◽

Cited By ~ 1

Author(s):

Sai Kiran Hota ◽

Julio Perez ◽

Gerardo Diaz

Keyword(s):

Heat Transfer ◽

Heat Exchange ◽

Exergy Analysis ◽

Energy Analysis ◽

Thermal Output ◽

Back Plate ◽

Large Heat ◽

Power Needs ◽

Tube Geometry ◽

Plate Width

Minichannel tubes have been successfully integrated into automotive, aerospace and HVAC due to their performance superiority and cost effectiveness. Recently, they have also been introduced in the solar thermal industry for similar reasons. Considering the indirect and limited contact area for heat exchange between absorber and fluid in a conventional solar collector, a minichannel tube has the advantage of providing an absorber surface with large heat transfer area and has less thermal resistance. Due to the method of construction, in many cases, minichannel tubes are separated by a few millimeters from each other, leaving a gap in between tubes that wastes collector area. The addition of a back plate to these minichannel-tube collectors will enhance the thermal output as they together provide a larger surface area for absorption. This effectively increases the thermal output. However, the balance between heat transfer and pumping power needs to be analyzed, thereby the need arises to optimize these geometric parameters. This paper attempts to determine these performance values while optimizing the minichannel-tube geometry and back plate width. From energy analysis, it is deduced that a back plate of 40mm width with the corresponding hydraulic diameter for a constant heat exchange width of 100mm maximizes the thermal performance. The exergy analysis further shows that when the back plate width was between 40mm–45mm, maximum of 73% exergy efficiency can be achieved.

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Heat transfer and energy analysis of a solar air collector with smooth plate

The European Physical Journal Applied Physics ◽

10.1051/epjap/2014130405 ◽

2014 ◽

Vol 66 (1) ◽

pp. 10901 ◽

Cited By ~ 6

Author(s):

Foued Chabane ◽

Noureddine Moummi

Keyword(s):

Heat Transfer ◽

Energy Analysis ◽

Solar Air Collector ◽

Smooth Plate

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Heat transfer optimization through new form of pin type of finned tube heat exchangers using the exergy and energy analysis

International Journal of Refrigeration ◽

10.1016/j.ijrefrig.2020.03.023 ◽

2020 ◽

Vol 117 ◽

pp. 12-22 ◽

Cited By ~ 1

Author(s):

Nidal H. Abu-Hamdeh ◽

Rashad A.R. Bantan ◽

Ashkan Alimoradi

Keyword(s):

Heat Transfer ◽

Heat Exchangers ◽

Energy Analysis ◽

Finned Tube ◽

Heat Transfer Optimization ◽

New Form

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Modeling of Steel Slab Reheating Process in a Walking Beam Reheating Furnace

Volume 2: Heat Transfer in Multiphase Systems; Gas Turbine Heat Transfer; Manufacturing and Materials Processing; Heat Transfer in Electronic Equipment; Heat and Mass Transfer in Biotechnology; Heat Transfer Under Extreme Conditions; Computational Heat Transfer; Heat Transfer Visualization Gallery; General Papers on Heat Transfer; Multiphase Flow and Heat Transfer; Transport Phenomena in Manufacturing and Materials Processing ◽

10.1115/ht2016-7282 ◽

2016 ◽

Cited By ~ 1

Author(s):

Guangwu Tang ◽

Arturo Saavedra ◽

Tyamo Okosun ◽

Bin Wu ◽

Chenn Q. Zhou ◽

...

Keyword(s):

Heat Transfer ◽

Three Dimensional ◽

Heat Transfer Model ◽

Furnace Operation ◽

Production Data ◽

Heating Process ◽

Transfer Model ◽

Transfer Coefficients ◽

Reheating Furnace ◽

Reheating Process

Slab reheating is a very important step in steel product manufacturing. A small improvement in reheating efficiency can translate into big savings to steel mills in terms of fuel consumption and productivity. Computational fluid dynamics (CFD) has been employed in conducting numerical simulations of the slab reheating furnace operation. However, a full industrial scale three-dimensional (3D) simulation of a slab reheating furnace, while comprehensive, is not an efficient way to conduct broad studies of the slab heating process. In this paper, a comprehensive two-dimensional (2D) numerical heat transfer model for slab reheating in a walking beam furnace was developed using the finite difference method. The 2D heat transfer model utilizes the heat transfer coefficients derived from a 3D reheating furnace CFD model which was validated by using mill instrumented slab trials. The 2D heat transfer model is capable of predicting slab temperature evolutions during the reheating processes based on the real time furnace conditions and steel physical properties. The 2D model was validated by using mill instrumented slab trials and production data. Good agreement between the model predictions and production data was obtained.

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