Estimation method for layered ground thermal conductivity using genetic algorithm based on a 2-D heat transfer model

2022 ◽  
pp. 111841
Author(s):  
Yongle Nian ◽  
Xiangyang Wang ◽  
Zhenpeng Deng ◽  
Wenlong Cheng
2011 ◽  
Vol 99-100 ◽  
pp. 112-115
Author(s):  
Ming Zhi Yu ◽  
Lei Zhang ◽  
Xiao Fei Yu ◽  
Zhao Hong Fang

A two dimensional numerical heat transfer model of buried geothermal heat exchanger has been established by finite element method. This model is used to analyse the heat transfer between buried vertical pipes and the ground, and determine the ground thermal properties together with parameters estimation method. The ground thermal conductivity of an actual project was measured and the analysis shows that the results can be used for engineering design.


2015 ◽  
Vol 13 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Kun Lei ◽  
Hongfang Ma ◽  
Haitao Zhang ◽  
Weiyong Ying ◽  
Dingye Fang

Abstract The heat conduction performance of the methanol synthesis reactor is significant for the development of large-scale methanol production. The present work has measured the temperature distribution in the fixed bed at air volumetric flow rate 2.4–7 m3 · h−1, inlet air temperature 160–200°C and heating tube temperature 210–270°C. The effective radial thermal conductivity and effective wall heat transfer coefficient were derived based on the steady-state measurements and the two-dimensional heat transfer model. A correlation was proposed based on the experimental data, which related well the Nusselt number and the effective radial thermal conductivity to the particle Reynolds number ranging from 59.2 to 175.8. The heat transfer model combined with the correlation was used to calculate the temperature profiles. A comparison with the predicated temperature and the measurements was illustrated and the results showed that the predication agreed very well with the experimental results. All the absolute values of the relative errors were less than 10%, and the model was verified by experiments. Comparing the correlations of both this work with previously published showed that there are considerable discrepancies among them due to different experimental conditions. The influence of the particle Reynolds number on the temperature distribution inside the bed was also discussed and it was shown that improving particle Reynolds number contributed to enhance heat transfer in the fixed bed.


2014 ◽  
Vol 924 ◽  
pp. 329-335 ◽  
Author(s):  
Cong Hang Li ◽  
Shi Chen Jiang ◽  
Zheng Ping Yao ◽  
Song Sheng ◽  
Xin Jian Jiang ◽  
...  

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.


2019 ◽  
Vol 65 (2) ◽  
pp. 169-185
Author(s):  
Yu. A. Shibayev ◽  
K. B. Tchikhatchev ◽  
V. Ya. Lipenkov ◽  
A. A. Ekaykin ◽  
E. Lefebvre ◽  
...  

The data on snow the temperature which was monitored to a depth of 10 m in the vicinity of Vostok Station by the TAUTO autonomous system in 2010–2017 are presented. By analyzing seasonal temperature variations at different depth with the aid of a heat-transfer model we have inferred a relationship between relative thermal conductivity of snow and its porosity at this site. The same approach was also applied to analyze similar data obtained at Dome Fuji station in 1995–1997. It was found that the thermal conductivity of snow layers with identical density is noticeably lower at Dome Fuji than at Vostok, which point to a difference in structural characteristics of snow that determine its thermophysical properties. We demonstrate that the conduction is the dominant heat-transport mechanism which controls the temperature distribution in snow pack on the Antarctic plateau. The obtained parameters of the heat-transfer model can be used for reconstructing the past surface temperature variations from the long-term temperature measurements in the upper 100 m thick layer of the ice sheet.


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