The Experts below are selected from a list of 8562 Experts worldwide ranked by ideXlab platform
Lingen Chen - One of the best experts on this subject based on the ideXlab platform.
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Constructal entransy optimizations for Insulation Layer of steel rolling reheating furnace wall with convective and radiative boundary conditions
Chinese Science Bulletin, 2014Co-Authors: Huijun Feng, Lingen ChenAbstract:Based on the entransy dissipation extremum principle for thermal Insulation process, the constructal optimizations for a plane Insulation Layer of the steel rolling reheating furnace wall with convective and radiative boundary conditions are carried out by taking the minimization of entransy dissipation rate as optimization objective. The optimal construct of the plane Insulation Layer is obtained. The results show that for the convective heat transfer boundary condition, the optimal constructs of the Insulation Layer obtained based on the minimizations of the entransy dissipation rate and heat loss rate are obviously different. Comparing the optimal construct obtained based on the minimization of the entransy dissipation rate with that based on the minimization of the heat loss rate, the entransy dissipation rate is reduced by 5.98 %, which makes the global thermal Insulation performance of the Insulation Layer improve. For the combined convective and radiative heat transfer boundary condition, compared the Insulation Layer having an increasing thickness with that having constant thickness and a decreasing thickness, the entransy dissipation rates are reduced by 16.59 % and 39.72 %, respectively, and the global thermal Insulation performance of the Insulation Layer is greatly improved. There exits an optimal constant coefficient \( a_{{2,{\text{opt}}}} \) which leads to the minimum dimensionless entransy dissipation rate of the Insulation Layer. The difference between the optimal constant coefficients \( a_{{2,{\text{opt}}}} \) obtained based on the minimizations of the entransy dissipation rate and the maximum temperature gradient of the Insulation Layer is small. This makes the corresponding thermal stress obtained based on the minimum dimensionless entransy dissipation rate also be small, and the global thermal Insulation performance and thermal safety of the Insulation Layer are improved simultaneously. The results obtained can provide some guidelines for the optimal designs of the Insulation Layers.
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Constructal entransy dissipation rate minimization for variable cross-section Insulation Layer of the steel rolling reheating furnace wall
International Communications in Heat and Mass Transfer, 2014Co-Authors: Huijun Feng, Lingen ChenAbstract:Abstract A variable cross-section (distributed thickness and width) Insulation Layer of the steel rolling reheating furnace wall is investigated subjected to the constraints of the total volume and cross-sectional area of the Insulation material. According to the entransy dissipation extremum principle of the thermal Insulation process, the thickness of the Insulation Layer is optimized by taking minimum entransy dissipation rate as optimization objective, and the optimal construct of the Insulation Layer is obtained. The results show that when the temperature distribution of the furnace is linear with the length, the optimal thickness of the Insulation Layer with minimum entransy dissipation rate is linear with the dimensionless longitudinal position, which is evidently different from that with minimum heat loss rate. When the dimensionless temperature at the low temperature side e = 0, the minimum entransy dissipation rate of the Insulation Layer with distributed thickness is decreased by 33.33% than that with uniform thickness, and is decreased by 8.85% than that based on minimum heat loss rate. Essentially, the temperature gradient field obtained based on minimum entransy dissipation rate is more homogenous than that based on minimum heat loss rate, and the corresponding thermal stress performance is better. The decrement of the entransy dissipation rate tends to increase for the exponential temperature distribution case with a large exponent. Moreover, the Insulation Layer with triangular cross-section has a better global thermal Insulation performance derived from entransy dissipation than those with rectangular and trapezoidal cross-sections. Therefore, the optimal construct obtained by adopting variable cross-section Insulation Layer (distributed thickness and width) and based on minimum entransy dissipation rate can improve the global thermal Insulation performance of the Insulation Layer derived from entransy dissipation, and can reduce its average heat loss rate defined based on entransy dissipation simultaneously. The optimal construct obtained based on minimum entransy dissipation rate can provide a new scheme for the design of practical thermal Insulation system different from that based on minimum heat loss rate, which can satisfy the different requirements in the design of practical thermal Insulation systems.
Wenbing Yu - One of the best experts on this subject based on the ideXlab platform.
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optimal design of thermal Insulation Layer of a tunnel in permafrost regions based on coupled heat water simulation
Applied Thermal Engineering, 2017Co-Authors: Shuangyang Li, Wenbing YuAbstract:Abstract In permafrost regions, if thermal Insulation Layer is thinner, seasonal freeze-thaw action can induce severe damages on a tunnel structure; otherwise, the construction cost is high and not economical. To find out a scientific balance between the safety and the economy of the tunnel in permafrost regions, an optimal design on the thermal Insulation Layer should be carried out according to some relevant numerical or analytical calculations. To solve this problem, a coupled heat-water model for the tunnel in cold regions is built on the basis of energy and mass conservation principles. Then a representative permafrost tunnel in the Qinghai-Tibet Plateau (QTP) is used as an example to simulate temperature and water processes of the surrounding permafrost, and thereby a key position and an unfavorable time are picked out for the optimal design. Subsequently, the optimal thickness of the thermal Insulation Layer for the permafrost tunnel is determined by a series of coupled heat-water simulations. Eventually, the temperature and water states of the surrounding permafrost of the tunnel at the unfavorable time are fully evaluated to make sure that the tunnel is free of freeze-thaw damages. This study is expected to better understand the coupled temperature and water processes in the surrounding permafrost of the tunnel and further design a safe and economical tunnel structure. Of course, it can serve as a reference for further investigation, too.
C P Wong - One of the best experts on this subject based on the ideXlab platform.
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Investigation the effect of silane onto fabricating polymer Insulation Layer by spin-coating for through silicon vias
2017 18th International Conference on Electronic Packaging Technology (ICEPT), 2017Co-Authors: Qiang Liu, Guoping Zhang, Rong Sun, S. Ricky W. Lee, C P WongAbstract:3D packaging using through silicon via (TSV) technology is becoming important in IC packaging industry. The polymer material as Insulation material was fabricated by the spin-coating or spray-coating process. And the polymer Insulation can relax some of the stress induced and makes the process more convenient compared with CVD. Therefore, it is the most cost effective technology for the wafer level packaging. In this study, some polymer Insulation materials with different silanes are investigated comprehensively, including viscosity thixotropic index, adhesion strength, thermogravimetry analysis, differential scanning calorimetry and conformal coating. All the results show that the silane has significant effect on the adhesion strength and conformal coating. The adhesion strength is improved when the silane with nitrogen atom, and the Insulation Layer can be spin-coated uniformly or most filled vias when the silane with different polarity are used.
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Fabricating photosensitive polymer Insulation Layer by spin-coating for through silicon vias
2016 17th International Conference on Electronic Packaging Technology (ICEPT), 2016Co-Authors: Guoping Zhang, C P WongAbstract:Through silicon via (TSV) is an enabling technology for 3D interconnection. The Insulation Layer at the bottom of the via usually needs to be removed in order to expose the pad so that the electrical interconnection from the front side to the back side can be realized. This removal may be implemented by plasma etching, laser drilling, or photolithography. Compared with the other two methods, photolithography is considered having the merits of high efficiency, high reliability and low cost. In this study, we developed a photosensitive polymer Insulation material that can be deposited with the spin-coating process. The photosensitive material at the bottom of the TSV was developed with potassium hydroxide (KOH) solution after exposure to thr 365 nm UV light. At last, the residual photosensitive polymer was cured via a preset heating procedure. The resulting polymer Insulation Layer exhibited excellent thermal stability, good chemical resistance, good adhesion and good thickness uniformity. Such a material may be considered a promising candidate for the Insulation Layer for the applications of CMOS image sensor (CIS) and fingerprint identification sensor with TSVs having a low aspect ratio.
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Fabricating polymer Insulation Layer by spin-coating for through silicon vias
2015 IEEE 65th Electronic Components and Technology Conference (ECTC), 2015Co-Authors: Guoping Zhang, Kun Jiang, Jinhui Li, C P WongAbstract:This paper reports a fabrication process for the deposition of a polymer Insulation Layer on the sidewall of through silicon vias in wafer level packaging. The novolac resin based glue was used as precursor to prepare the Insulation Layer. The glue is a Newtonian fluid and has low viscosity (24 mPa*s @ 100 l/s) as well as low contact angle (25.9°) to silicon. The resultant polymer Insulation Layer has a shearing strength as high as 25.8 Kg/mm2. Furthermore, the polymer Insulation Layer exhibits good uniformity in thickness and roughness over the whole 8" wafer. On the conformal coating of the polymer Insulation Layer, the Ti/Cu seed Layer and Cu conductive Layer were fabricated by PVD and electroplating. Therefore, all the results show that the polymer materials could be a reliable and economical solution for the TSV insulator in the view of wafer level packaging.
Enshen Long - One of the best experts on this subject based on the ideXlab platform.
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effect of the thermal Insulation Layer location on wall dynamic thermal response rate under the air conditioning intermittent operation
Case Studies in Thermal Engineering, 2017Co-Authors: Lili Zhang, Xi Meng, Yating Wang, Enshen LongAbstract:Abstract Although the air-conditioning intermittent operation is widely used in buildings, more attention is focused on the air-conditioning continuous operation in the whole building to simplify energy conservation design, and thereby, the operation method inconsistence of air-conditioning must lead to the large difference between actual value and design value of energy consumption. According to this situation, in order to explore the wall energy conservation difference under the continuous and intermittent operation of air-conditioning, a experiment is built to analyze the effect of the thermal Insulation Layer location on wall dynamic thermal response rate. Experimental result shows that under the air-conditioning intermittent operation, wall cold storage is the main source of air-conditioning load formed by walls and the wall internal Layer has the significant effect on the wall dynamic thermal response performance. And the closer to wall inner surface for the thermal Insulation Layer, the lower the inner surface temperature and the higher the wall thermal response rate. Meanwhile, the internal thermal Insulation wall has the smallest heat flow value, which is less 35–86% than external thermal Insulation wall and the sandwich thermal Insulation wall, although they have the same heat transfer coefficients.
Huijun Feng - One of the best experts on this subject based on the ideXlab platform.
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Constructal entransy optimizations for Insulation Layer of steel rolling reheating furnace wall with convective and radiative boundary conditions
Chinese Science Bulletin, 2014Co-Authors: Huijun Feng, Lingen ChenAbstract:Based on the entransy dissipation extremum principle for thermal Insulation process, the constructal optimizations for a plane Insulation Layer of the steel rolling reheating furnace wall with convective and radiative boundary conditions are carried out by taking the minimization of entransy dissipation rate as optimization objective. The optimal construct of the plane Insulation Layer is obtained. The results show that for the convective heat transfer boundary condition, the optimal constructs of the Insulation Layer obtained based on the minimizations of the entransy dissipation rate and heat loss rate are obviously different. Comparing the optimal construct obtained based on the minimization of the entransy dissipation rate with that based on the minimization of the heat loss rate, the entransy dissipation rate is reduced by 5.98 %, which makes the global thermal Insulation performance of the Insulation Layer improve. For the combined convective and radiative heat transfer boundary condition, compared the Insulation Layer having an increasing thickness with that having constant thickness and a decreasing thickness, the entransy dissipation rates are reduced by 16.59 % and 39.72 %, respectively, and the global thermal Insulation performance of the Insulation Layer is greatly improved. There exits an optimal constant coefficient \( a_{{2,{\text{opt}}}} \) which leads to the minimum dimensionless entransy dissipation rate of the Insulation Layer. The difference between the optimal constant coefficients \( a_{{2,{\text{opt}}}} \) obtained based on the minimizations of the entransy dissipation rate and the maximum temperature gradient of the Insulation Layer is small. This makes the corresponding thermal stress obtained based on the minimum dimensionless entransy dissipation rate also be small, and the global thermal Insulation performance and thermal safety of the Insulation Layer are improved simultaneously. The results obtained can provide some guidelines for the optimal designs of the Insulation Layers.
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Constructal entransy dissipation rate minimization for variable cross-section Insulation Layer of the steel rolling reheating furnace wall
International Communications in Heat and Mass Transfer, 2014Co-Authors: Huijun Feng, Lingen ChenAbstract:Abstract A variable cross-section (distributed thickness and width) Insulation Layer of the steel rolling reheating furnace wall is investigated subjected to the constraints of the total volume and cross-sectional area of the Insulation material. According to the entransy dissipation extremum principle of the thermal Insulation process, the thickness of the Insulation Layer is optimized by taking minimum entransy dissipation rate as optimization objective, and the optimal construct of the Insulation Layer is obtained. The results show that when the temperature distribution of the furnace is linear with the length, the optimal thickness of the Insulation Layer with minimum entransy dissipation rate is linear with the dimensionless longitudinal position, which is evidently different from that with minimum heat loss rate. When the dimensionless temperature at the low temperature side e = 0, the minimum entransy dissipation rate of the Insulation Layer with distributed thickness is decreased by 33.33% than that with uniform thickness, and is decreased by 8.85% than that based on minimum heat loss rate. Essentially, the temperature gradient field obtained based on minimum entransy dissipation rate is more homogenous than that based on minimum heat loss rate, and the corresponding thermal stress performance is better. The decrement of the entransy dissipation rate tends to increase for the exponential temperature distribution case with a large exponent. Moreover, the Insulation Layer with triangular cross-section has a better global thermal Insulation performance derived from entransy dissipation than those with rectangular and trapezoidal cross-sections. Therefore, the optimal construct obtained by adopting variable cross-section Insulation Layer (distributed thickness and width) and based on minimum entransy dissipation rate can improve the global thermal Insulation performance of the Insulation Layer derived from entransy dissipation, and can reduce its average heat loss rate defined based on entransy dissipation simultaneously. The optimal construct obtained based on minimum entransy dissipation rate can provide a new scheme for the design of practical thermal Insulation system different from that based on minimum heat loss rate, which can satisfy the different requirements in the design of practical thermal Insulation systems.