scholarly journals Coupled heat transfer model for the combustion and steam characteristics of coal-fired boilers

2021 ◽  
Vol 15 (1) ◽  
pp. 490-502
Author(s):  
Yan Xie ◽  
Xin Liu ◽  
Chaoqun Zhang ◽  
Jun Zhao ◽  
Heyang Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Coupled 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 Study on the Coupled Heat Transfer Model Based on Groundwater Advection and Axial Heat Conduction for the Double U-Tube Vertical Borehole Heat Exchanger

2020 ◽  
Vol 12 (18) ◽  
pp. 7345
Author(s):  
Linlin Zhang ◽  
Zhonghua Shi ◽  
Tianhao Yuan
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Flow Rate ◽  
Transfer Rate ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Borehole Heat Exchanger ◽  
Coupled Heat Transfer ◽  
Advection Velocity

In this paper, a dynamic heat transfer model for the vertical double U-tube borehole heat exchanger (BHE) was developed to comprehensively address the coupled heat transfer between the in-tube fluid and the soil with groundwater advection. A new concept of the heat transfer effectiveness was also proposed to evaluate the BHE heat exchange performance together with the index of the heat transfer rate. The moving finite line heat source model was selected for heat transfer outside the borehole and the steady-state model for inside the borehole. The data obtained in an on-site thermal response test were used to validate the physical model of the BHE. Then, the effects of soil type, groundwater advection velocity, inlet water flow rate, and temperature on the outlet water temperature of BHE were explored. Results show that ignoring the effects of groundwater advection in sand gravel may lead to deviation in the heat transfer rate of up to 38.9% of the ground loop design. The groundwater advection fosters the heat transfer of BHE. An increase in advection velocity may also help to shorten the time which takes the surrounding soil to reach a stable temperature. The mass flow rate of the inlet water to the BHE should be more than 0.5 kg·s−1 but should not exceed a certain upper limit under the practical engineering applications with common scale BHE. The efficiency of the heat transfer of the double U-tube BHE was determined jointly by factors such as the soil’s physical properties and the groundwater advection velocity.

Inverse problem-coupled heat transfer model for steel continuous casting

2014 ◽  
Vol 214 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Zhaofeng Wang ◽  
Man Yao ◽  
Xudong Wang ◽  
Xiaobing Zhang ◽  
Longsheng Yang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Inverse Problem ◽  
Continuous Casting ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Coupled Heat Transfer ◽  
Steel Continuous Casting

Numerical Study on Coupled Heat Transfer of Thrust Chamber with Raised Structure

2012 ◽  
Vol 516-517 ◽  
pp. 107-110
Author(s):  
Tao Nie ◽  
Wei Qiang Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Three Dimensional ◽  
Axial Direction ◽  
Heat Transfer Model ◽  
Chamber Wall ◽  
Transfer Model ◽  
Thrust Chamber ◽  
Coupled Heat Transfer ◽  
Flow And Heat Transfer

By the use of the map of the thermal resistance among volume cells, we establish a coupled heat transfer model of the hot gas, chamber wall and coolant. A reduced one-dimensional model was employed for the coolant flow and heat transfer, and three dimensional heat transfer model was used to calculate the coupling heat transfer through the wall, considering heat transfer at circumferential direction, axial direction and radial direction. Based on the study the mechanism of the cooling structure heat transfer, the computing model was employed and achieved the rule of heat flux and temperature of gas wall. Simultaneously, influence of different cooling structure was performed. The results indicated that the cooling structure with raised structure could better reduce the temperature of the chamber wall.

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