Modeling of Fine Annealing of Large Size Optical Glass

2013 ◽  
Author(s):  
Yefeng Ma ◽  
Nan Wu ◽  
Lihua Li ◽  
Song Zhang ◽  
Lili Zheng ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Temperature Distribution ◽  
Temperature Difference ◽  
Optical Glass ◽  
Maximum Temperature ◽  
Glass Temperature ◽  
Insulation Layer ◽  
Large Size ◽  
Fine Annealing

Large size optical glass has attracted much attention due to its applications in large optical devices. Due to stringent requirement in applications, extra thermal treatment should be investigated to increase the quality of product. During fine annealing, glass temperature is crucial for final quality of optical glass as a result of its influence on thermal stress and optical homogeneity. To ensure a high performance, temperature distribution in the glass should be homogeneous and symmetric, and maximum temperature difference is expected to be small. This paper proposed two approaches to improve the glass temperature uniformity during fine annealing. Firstly, the glass blocks are packaged with heat exchange blocks on the top and bottom surfaces and insulation layer on the side. Thickness of layers and materials usage are investigated. Simulation results show that the homogeneity and symmetry of glass temperature distribution can be improved. Temperature difference in the horizontal direction can be further reduced in the case of 10mm copper heat exchange block together with 50mm insulation layer. Secondly, a muffle apparatus is utilized and symmetry of temperature distribution can be improved. Furthermore, above two approaches can be combined. Knowledge learned in this work can be used to guide industrial fine annealing process to reduce the stress level and improve the symmetric of residual stress.

MODELING THE EFFECT OF HEAT EXCHANGE ON THE EFFICIENCY OF A THERMOELECTRIC COOLER

2020 ◽  
Vol 2 ◽  
pp. 132-135
Author(s):  
O.I. MARKOV
Keyword(s):  
Numerical Calculation ◽  
Heat Exchange ◽  
Solid State ◽  
Numerical Modelling ◽  
Temperature Difference ◽  
Maximum Temperature ◽  
Thermoelectric Cooler ◽  
Maximum Temperature Difference ◽  
Peltier Cooler ◽  
Account Heat

Numerical modelling thermal and thermoelectric processes in a branch of solid–state thermoelectric of Peltier cooler is performed, taking into account heat exchange by convection and radiation. The numerical calculation of the branch was carried out in the mode of the maximum temperature difference.

scholarly journals Homogenization of Radial Temperature by a Tungsten Sink in Sublimation Growth of 45 mm AlN Single Crystal

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5553
Author(s):  
Yue Yu ◽  
Botao Liu ◽  
Xia Tang ◽  
Sheng Liu ◽  
Bing Gao
Keyword(s):  
Thermal Stress ◽  
Crystal Growth ◽  
Heat Exchange ◽  
Single Crystal ◽  
Numerical Experiments ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Large Size ◽  
Sublimation Growth

To reduce the thermal stress during the sublimation growth of 45 mm AlN single crystal, a tungsten sink was put on the top of the crucible lid. Numerical experiments showed that the radial temperature gradient was reduced due to the homogenization effect on temperature as a result of the sink. Therefore, this simple tungsten sink method has the potential to grow large-size AlN ingots with fewer cracks. It also reveals that enhancing the heat exchange of the crucible lid is an effective way to improve the quality of crystal growth.

A Study on Storing Process of Thermoforming Using Finite Difference Method

2011 ◽  
Vol 314-316 ◽  
pp. 571-575
Author(s):  
Zhen Zhe Li ◽  
Gui Ying Shen ◽  
Xiao Qian Wang ◽  
Mei Qin Li ◽  
Yun De Shen
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Finite Difference Method ◽  
Initial Temperature ◽  
Thickness Distribution ◽  
Time Dependent ◽  
Maximum Temperature ◽  
Uniform Thickness ◽  
Maximum Temperature Difference

Obtaining a uniform thickness of the final product using thermoforming is difficult, and the thickness distribution depends strongly on the distribution of the sheet temperature. In this paper, the time-dependent temperature distribution of the total sheets in the storing process was studied because the temperature after the storing process is the initial temperature of the preheating process. An analysis code for simulating the storing process was developed under the condition that the thermal conductivity caused by contact resistance between sheets was assumed as a large value. In this study, the number of sheets in the storing room was adjusted for finding out the effect of it. The analysis results show that maximum temperature difference between sheets was significantly different when adjusting the number of sheets in the storing room. The temperature distribution of the total sheets and the method for analysis in this study will be used to optimize the storing process for higher quality of final products.

Vertical Thermal Distribution at the near Dam Region of the Three Gorges Reservoir in the Initial Impoundment Period

2014 ◽  
Vol 889-890 ◽  
pp. 1649-1652
Author(s):  
L.Q. Dai ◽  
H.C. Dai ◽  
B.W. Wang
Keyword(s):  
Temperature Distribution ◽  
Water Temperature ◽  
Temperature Difference ◽  
Three Gorges Reservoir ◽  
Thermal Structure ◽  
Maximum Temperature ◽  
Three Gorges ◽  
Bottom Water Temperature ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

Water temperature plays a crucial role in water ecological environment both in the reservoir and downstream area. Three Gorges Project (TGP) is the largest hydraulic engineering in the world, and changes of water quality attract much more attention, especially in the thermal structure since initial impoundment in 2003. In order to clearly understand water temperature distribution after the initial impoundment in the Three Gorges Reservoir (TGR), we monitored the temperature distribution of the Taipingxi section which was not far from the dam from early April to the end of July in 2004. According to the analyzing of the monitoring data of transverse and vertical temperature variation, we could find that when water level went up to 135m above sea level (a.s.l.) or 139m in the initial impoundment phase, the temperature mixed uniformly in transverse direction. Excepting April, there was basically had no temperature difference in vertical direction, even in April, the maximum temperature difference was only 1.39°C within 100 meters (April 22), the average temperature gradient was only 0.014°C/m; Both the temperature of water and atmosphere have similar variation tendency, but the response of the water temperature to atmosphere is delayed, especially the bottom water temperature. The result indicate that the reservoir displayed a mixed thermal structure during initial impoundment phase, therefore, the release had no change before and after impoundment, also had little influence on the aquatic organism and crops at downstream , the work provide a scientific basis for the development of pollution control and ecological protection measure.

Numerical Simulation of Temperature Field in the Cyclone

2012 ◽  
Vol 614-615 ◽  
pp. 208-211
Author(s):  
Zhen Wei Zhang ◽  
Ying Yu ◽  
Jie Leng ◽  
Su Juan Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Turbulence Model ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Inlet Tube ◽  
Higher Temperature ◽  
Air Compression

The temperature distribution of the cyclone was analyzed in the presented work, which was imitated by using RSM turbulence model of software FLUENT. Temperature difference in different regions is less than one centigrade degree with the maximum temperature in the cone part and the minimum temperature in inlet tube and cylinder part of the cyclone, what’s more, the temperature is relatively higher near the wall. The air compression can lead the higher temperature in the lower part, so the cone part has the maximum temperature. The higher temperature near the wall is caused by the friction between the wall and flow.

Stress and Fatigue Analysis of Pressurizer Surge Line under Thermal Stratification

2019 ◽  
Vol 795 ◽  
pp. 268-275
Author(s):  
Peng Tang ◽  
Zhi Wei Liu ◽  
Hong Wei Qiao ◽  
Peng Zhou Li
Keyword(s):  
Temperature Distribution ◽  
Temperature Difference ◽  
Thermal Stratification ◽  
Nuclear Power ◽  
Power Plants ◽  
Load Condition ◽  
Maximum Temperature ◽  
Large Temperature ◽  
Maximum Temperature Difference ◽  
Surge Line

Pressurizer surge line is one of the key equipments of nuclear power plants. The thermal stratification due to the intersection of hot and cold fluids inside the pressurizer surge line may affect the safe operation of nuclear power plant. In order to investigate the stress distribution and fatigue characteristics of surge line subjected to long-term thermal stratified loadings, a mechanical model of the surge line was established. And then, according to different temperature distribution assumptions, thermal stress analysis and fatigue assessment were conducted. The results show that the maximum stress appears under the load condition with maximum temperature difference, and finer temperature distribution can obtain more accurate stress and displacement results. The maximum value of fatigue cumulative coefficient appears at the junction of straight pipe and elbow with large temperature difference.

Numerical Simulation of Temperature Field in the Cyclone

2012 ◽  
Vol 479-481 ◽  
pp. 462-466
Author(s):  
Ping Yang Xiao ◽  
Zhen Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Turbulence Model ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Inlet Tube ◽  
Higher Temperature ◽  
Air Compression

This paper mainly focuses on the numerical simulation of temperature field in the cyclone separation. The authors took advantage of RSM turbulence model of software FLUENT to imitate the temperature field. This thesis puts forward the temperature distribution of the cyclone, and figures out that the overall temperature is 373°C. Temperature difference in different region is less than one centigrade degree with the maximum temperature in the cone part and the minimum temperature in inlet tube and cylinder part of the cyclone, what’s more, the temperature is relatively higher near the wall. The air compression can lead the higher temperature in the lower part, so the cone part has the highest temperature. The higher temperature near the wall is caused by the friction between the wall and flow.

Time-Dependent Temperature Distribution of Sheets in the Stage of Storing

2010 ◽  
Vol 26-28 ◽  
pp. 1137-1141
Author(s):  
Zhen Zhe Li ◽  
Rui Jiang ◽  
Dong Ji Xuan ◽  
Tai Hong Cheng ◽  
Seoung Yun Seol ◽  
...  
Keyword(s):  
Experimental Data ◽  
Temperature Distribution ◽  
Temperature Difference ◽  
Thickness Distribution ◽  
Time Dependent ◽  
Uniform Thickness

Obtaining a uniform thickness of the final product using thermoforming is difficult, and the thickness distribution depends strongly on the distribution of the sheet temperature. In this paper, the time-dependent temperature distribution of the total sheets in the stage of storing was studied using the analysis code which has been verified based on the experimental data. It was found out that the time for storing should be managed for decreasing the temperature difference between the sheets. The time-dependent temperature distribution of the total sheets and the method for analysis in this study will be used to improve the quality of the final products.

scholarly journals The Effect of Tab Attachment Positions and Cell Aspect Ratio on Temperature Difference in Large-Format LIBs Using Design of Experiments

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 116
Author(s):  
Jeong-Joo Lee ◽  
Ji-San Kim ◽  
Hyuk-Kyun Chang ◽  
Dong-Chan Lee ◽  
Chang-Wan Kim
Keyword(s):  
Temperature Distribution ◽  
Aspect Ratio ◽  
Design Of Experiments ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Lithium Ion ◽  
Maximum Temperature ◽  
Large Temperature ◽  
Large Format ◽  
Design Factors

Large-format lithium-ion batteries (LIBs) suffer from problems in terms of their product life and capacity due to large temperature differences in LIB cells. This study analyzes the effect of design factors on temperature distribution using a 3D electrochemical–thermal model. The design of experiments methodology is used to obtain the sampling points and analyze the effect of the cell aspect ratio, negative tab attachment position, and positive tab attachment position. These were considered as design factors for the maximum and minimum temperatures, as well as their difference, in large-format LIB cells. The results reveal that the cell aspect ratio, negative tab attachment position, and positive tab attachment position considerably influence temperature distribution. The cell aspect ratio has the most significant effect on the temperature distribution by changing the longest current pathway and the distance between tabs and the lowest temperature point in the LIB cell. A positive tab attachment position affects the maximum temperature, minimum temperature, and the temperature difference due to the heat generation caused by the high resistance of aluminum, which the positive tab is made. Furthermore, a negative tab attachment position affects the minimum temperature due to low resistance.

scholarly journals Monitoring and analysis of vertical thermal structure of the Three Gorges Reservoir

2019 ◽  
Vol 118 ◽  
pp. 03035
Author(s):  
Lingquan Dai ◽  
Haibo Liu ◽  
Wei Li ◽  
Zhengyang Tang ◽  
Yang Xu
Keyword(s):  
Temperature Distribution ◽  
Water Temperature ◽  
Temperature Difference ◽  
Three Gorges Reservoir ◽  
Thermal Structure ◽  
Maximum Temperature ◽  
Three Gorges ◽  
Bottom Water Temperature ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

Water temperature plays a crucial role in water ecological environment both in the reservoir and downstream area. Three Gorges Project (TGP) is the largest hydraulic engineering in the world, and changes of water quality attract much more attention, especially in the thermal structure since impoundment. In order to clearly understand water temperature distribution after impoundment in the Three Gorges Reservoir (TGR), we monitored the temperature distribution of the Taipingxi section which was not far from the dam from early April to the end of July. According to the analyzing of the monitoring data of transverse and vertical temperature variation, we could find that the temperature mixed uniformly in transverse direction. Excepting April, there was basically had no temperature difference in vertical direction, even in April, the maximum temperature difference was only 1.39°C within 100 meters (April 22), the average temperature gradient was only 0.014°C/m; Both the temperature of water and atmosphere have similar variation tendency, but the response of the water temperature to atmosphere is delayed, especially the bottom water temperature. The result indicate that the reservoir has mixed thermal structure during impoundment phase, so the release temperature had little change after the impoundment, the work provide a scientific basis for the development of pollution control and ecological protection measure.

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