Heat Transfer During Cooling of Bulk Distillers Dried Grains with Solubles (DDGS)

2019 ◽  
Vol 35 (4) ◽  
pp. 569-577
Author(s):  
Kaliramesh Siliveru ◽  
Mark E. Casada ◽  
R. P. Kingsly Ambrose
Keyword(s):  
Heat Transfer ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Heat Transfer Model ◽  
Medium Size ◽  
Transfer Model ◽  
Ambient Conditions ◽  
Cooling Pattern ◽  
Environmental Relative Humidity ◽  
Volume Method

Abstract. DDGS is often transported in railcars and trucks from the ethanol plants to the feed mills and animal farms. During unloading, flowability of DDGS is often reduced due to caking of DDGS bulk. Based on published research, the environmental relative humidity, DDGS glass transition temperature, syrup content, and duration of cooling of DDGS piles influence the caking behavior of DDGS. The objective of this study was to develop and validate a heat transfer model for predicting the cooling pattern of DDGS piles. A finite volume method approach was used to develop the heat transfer model. Ergun’s equation was used to implement airflow resistance in the porous media of the DDGS bulk. The heat transfer inside the pile was simulated for winter (6°C) and summer (24°C) ambient conditions. The model agreed well with the experimental temperature measurements from the three sets of experiments with two sizes of experimental piles. The overall predicted temperatures were 2.7°C and 0.7°C higher than the observed temperatures for small- and medium-size experimental piles, respectively. This heat transfer model could be used to predict the temperature variations in DDGS bulk during storage and as a measure to predict the caking behavior. Keywords: Caking, DDGS, Finite volume method, Heat transfer.

Research on Heat Transfer Characteristics of Nano-Porous Silica Aerogel Material and its Application on Mars Surface Mission

2014 ◽  
Vol 924 ◽  
pp. 329-335 ◽  
Author(s):  
Cong Hang Li ◽  
Shi Chen Jiang ◽  
Zheng Ping Yao ◽  
Song Sheng ◽  
Xin Jian Jiang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Silica Aerogel ◽  
Thermal Environment ◽  
Porous Silica ◽  
Heat Transfer Model ◽  
Heat Radiation ◽  
Transfer Model ◽  
Ambient Conditions ◽  
Coupled Heat Transfer

Based on the nanoporous network structure features of silica aerogel, the gas-solid coupled heat transfer model of silica aerogel is analyzed, and the calculation formulas of the gas-solid coupled, the gas thermal conductivity and the heat radiation within the aerogel are derived. The thermal conductivity of pure silica aerogel is calculated according to the derived heat transfer model and is also experimentally measured. Moreover, measurements on the thermal conductivities of silica aerogel composites with different densities at ambient conditions are performed. And finally, a novel design of silica aerogel based integrated structure and thermal insulation used for withstanding the harsh thermal environment on the Martin surface is presented.

scholarly journals Comparison of the Finite Volume and Lattice Boltzmann Methods for Solving Natural Convection Heat Transfer Problems inside Cavities and Enclosures

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
M. Goodarzi ◽  
M. R. Safaei ◽  
A. Karimipour ◽  
K. Hooman ◽  
M. Dahari ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Lattice Boltzmann ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Square Enclosure ◽  
Volume Method

Different numerical methods have been implemented to simulate internal natural convection heat transfer and also to identify the most accurate and efficient one. A laterally heated square enclosure, filled with air, was studied. A FORTRAN code based on the lattice Boltzmann method (LBM) was developed for this purpose. The finite difference method was applied to discretize the LBM equations. Furthermore, for comparison purpose, the commercially available CFD package FLUENT, which uses finite volume Method (FVM), was also used to simulate the same problem. Different discretization schemes, being the first order upwind, second order upwind, power law, and QUICK, were used with the finite volume solver where the SIMPLE and SIMPLEC algorithms linked the velocity-pressure terms. The results were also compared with existing experimental and numerical data. It was observed that the finite volume method requires less CPU usage time and yields more accurate results compared to the LBM. It has been noted that the 1st order upwind/SIMPLEC combination converges comparatively quickly with a very high accuracy especially at the boundaries. Interestingly, all variants of FVM discretization/pressure-velocity linking methods lead to almost the same number of iterations to converge but higher-order schemes ask for longer iterations.

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