Optimization of Cooled Shields in Insulations

1984 ◽  
Vol 106 (4) ◽  
pp. 871-875 ◽  
Author(s):  
J. C. Chato ◽  
J. M. Khodadadi
Keyword(s):  
Dissipation Rate ◽  
Heat Dissipation ◽  
Absolute Temperature ◽  
Entropy Production Rate ◽  
Insulation Layer ◽  
Temperature Ratio ◽  
Insulation System ◽  
Simple Method ◽  
Practical Applications ◽  
Cooling Loads

A relatively simple method has been developed to optimize the location, temperature, and heat dissipation rate of each cooled shield inside an insulation layer. The method is based on the minimization of the entropy production rate, which is proportional to the heat leak across the insulation. The results show that the maximum number of shields to be used in most practical applications is three. However, cooled shields are useful only at low values of the overall, cold wall to hot wall absolute temperature ratio. The performance of the insulation system is relatively insensitive to deviations from the optimum values of temperature and location of the cooling shields. Design curves are presented for rapid estimates of the locations and temperatures of cooling shields in various types of insulations, and an equation is given for calculating the cooling loads for the shields.

scholarly journals A new method for estimating of evapotranspiration and surface soil moisture from optical and thermal infrared measurements: the simplified triangle

2020 ◽  
Author(s):  
Toby N. Carlson ◽  
George Petropoulos
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Heat Fluxes ◽  
Surface Model ◽  
Landsat 8 ◽  
Simple Method ◽  
Practical Applications ◽  
Infrared Measurements

Earth Observation (EO) provides a promising approach towards deriving accurate spatiotemporal estimates of key parameters characterizing land surface interactions, such as latent (LE) and sensible (H) heat fluxes as well as soil moisture content. This paper proposes a very simple method to implement, yet reliable to calculate evapotranspiration fraction (EF) and surface moisture availability (Mo) from remotely sensed imagery of Normalized Difference Vegetation Index (NDVI) and surface radiometric temperature (Tir). The method is unique in that it derives all of its information solely from these two images. As such, it does not depend on knowing ancillary surface or atmospheric parameters, nor does it require the use of a land surface model. The procedure for computing spatiotemporal estimates of these important land surface parameters is outlined herein stepwise for practical application by the user. Moreover, as the newly developedscheme is not tied to any particular sensor, it can also beimplemented with technologically advanced EO sensors launched recently or planned to be launched such as Landsat 8 and Sentinel 3. The latter offers a number of key advantages in terms of future implementation of the method and wider use for research and practical applications alike.

Study on Spread of Fire Overflow on Building Facades with Insulation Materials

2013 ◽  
Vol 405-408 ◽  
pp. 2438-2442
Author(s):  
Yan Feng Li ◽  
Cong Cong Xu ◽  
Xue Fei Xing ◽  
Jin Zhang ◽  
Cheng Hu
Keyword(s):  
Numerical Simulation ◽  
Thermal Insulation ◽  
Maximum Temperature ◽  
Computational Results ◽  
Exterior Wall ◽  
Insulation Layer ◽  
Insulation System ◽  
High Rise ◽  
Building Facades ◽  
Fire Barrier

Fire overflow on exterior wall with thermal insulation system has been studied by numerical simulation. The spread laws of fire overflow are analyzed through the temperature distribution near the window. The computational results are compared with those of test in the Exterior Insulation Fire Barrier Technical Guidelines (EIFBTG). It has been found that the calculated maximum temperature points is closed to the test on the first floor, the first ceiling, and the points near the above two windows. However, there are differences between two kinds of results above two floors and ceilings, and the points near the first window. It has also shown that when the HHR is 7.5KW, the scope of damage of exterior thermal insulation layer is about 15 square meters near the window. The research would provide reference for fire protection design of exterior wall thermal insulation in the high-rise buildings.

A Simple Method for Thermal Characterization of Stacked Die Electronic Packages in Staggered Arrangement

2018 ◽  
Vol 15 (3) ◽  
pp. 117-125 ◽  
Author(s):  
Bharath R. Bharadwaj ◽  
SriNithish Kandagadla ◽  
Praveen J. Nadkarni ◽  
V. Krishna ◽  
T. R. Seetharam ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Superposition Principle ◽  
Thermal Characterization ◽  
Electronic Packages ◽  
Heat Sources ◽  
Linear Superposition ◽  
Simple Method ◽  
Ansys Simulation ◽  
Staggered Arrangement

Abstract The need for compactness and efficiency of processing devices has kept increasing rapidly over the past few years. This need for compactness has driven the dice to be stacked one above the other. But with this come the difficulty of heat dissipation and its characterization because there are multiple heat sources and a single effective heat-conductive path. Hence, it becomes important to know the distribution and characterization of heat and temperature to provide effective cooling systems. In this article, we discuss the temperature distribution of various power configurations on stacked dice with five dice, when the dice are in staggered arrangement. The simulations have been carried out for both free convection and forced convection conditions using the ANSYS commercial software. The linear Superposition principle (LSP) is demonstrated on these configurations and validated with the results obtained from ANSYS simulation. LSP can be applied for the quick estimation of die temperatures with negligible error.

scholarly journals Design and Verification of a Deep Rock Corer with Retaining the In Situ Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zhiqiang He ◽  
Heping Xie ◽  
Mingzhong Gao ◽  
Ling Chen ◽  
Bo Yu ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Heat Dissipation ◽  
Electric Heating ◽  
Transfer Model ◽  
Hollow Glass Microsphere ◽  
Insulation Material ◽  
Insulation System ◽  
Deep Rock ◽  
Active Thermal Insulation

Deep rock is always under high-temperature conditions. However, traditional coring methods generally have no thermal insulation design, which introduces large deviations in the guidance required for resource mining. Thus, a thermal insulation design that utilizes active and passive thermal insulation was proposed for deep rock corers. The rationale behind the active thermal insulation scheme was to maintain the in situ core temperature through electric heating that was controlled by using a proportional-integral-derivative (PID) chip. Graphene heating material could be used as a heating material for active thermal insulation through testing. In regard to the passive thermal insulation scheme, we conducted insulation and microscopic and insulation effectiveness tests for hollow glass microsphere (HGM) composites and SiO2 aerogels. Results showed that the #1 HGM composite (C1) had an excellent thermal insulation performance (3 mm thick C1 can insulate to 82.6°C), high reflectivity (90.02%), and wide applicability. Therefore, C1 could be used as a passive insulation material in deep rock corers. Moreover, a heat transfer model that considered multiple heat dissipation surfaces was established, which can provide theoretical guidance for engineering applications. Finally, a verification test of the integrated active and passive thermal insulation system (graphene heating material and C1) was carried out. Results showed that the insulating effect could be increased by 13.3%; thus, the feasibility of the integrated thermal insulation system was verified. The abovementioned design scheme and test results provide research basis and guidance for the development of thermally insulated deep rock coring equipment.

scholarly journals A simple method for implementing Monte Carlo tests

2019 ◽  
Vol 35 (3) ◽  
pp. 1373-1392 ◽  
Author(s):  
Dong Ding ◽  
Axel Gandy ◽  
Georg Hahn
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Statistical Test ◽  
Uniform Bound ◽  
Data Set ◽  
Simple Method ◽  
Practical Applications ◽  
Tuning Parameters ◽  
Sequence Method ◽  
Uniformly Bounded

Abstract We consider a statistical test whose p value can only be approximated using Monte Carlo simulations. We are interested in deciding whether the p value for an observed data set lies above or below a given threshold such as 5%. We want to ensure that the resampling risk, the probability of the (Monte Carlo) decision being different from the true decision, is uniformly bounded. This article introduces a simple open-ended method with this property, the confidence sequence method (CSM). We compare our approach to another algorithm, SIMCTEST, which also guarantees an (asymptotic) uniform bound on the resampling risk, as well as to other Monte Carlo procedures without a uniform bound. CSM is free of tuning parameters and conservative. It has the same theoretical guarantee as SIMCTEST and, in many settings, similar stopping boundaries. As it is much simpler than other methods, CSM is a useful method for practical applications.

scholarly journals Enhanced Stretchable and Sensitive Strain Sensor via Controlled Strain Distribution

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 218 ◽  
Author(s):  
Huamin Chen ◽  
Longfeng Lv ◽  
Jiushuang Zhang ◽  
Shaochun Zhang ◽  
Pengjun Xu ◽  
...  
Keyword(s):  
Strain Distribution ◽  
Tensile Strain ◽  
Strain Sensor ◽  
Gauge Factor ◽  
Simple Method ◽  
Practical Applications ◽  
Simple Strategy ◽  
Highly Sensitive ◽  
Highly Stretchable ◽  
Maximum Tensile Strain

Stretchable and wearable opto-electronics have attracted worldwide attention due to their broad prospects in health monitoring and epidermal applications. Resistive strain sensors, as one of the most typical and important device, have been the subject of great improvements in sensitivity and stretchability. Nevertheless, it is hard to take both sensitivity and stretchability into consideration for practical applications. Herein, we demonstrated a simple strategy to construct a highly sensitive and stretchable graphene-based strain sensor. According to the strain distribution in the simulation result, highly sensitive planar graphene and highly stretchable crumpled graphene (CG) were rationally connected to effectively modulate the sensitivity and stretchability of the device. For the stretching mode, the device showed a gauge factor (GF) of 20.1 with 105% tensile strain. The sensitivity of the device was relatively high in this large working range, and the device could endure a maximum tensile strain of 135% with a GF of 337.8. In addition, in the bending mode, the device could work in outward and inward modes. This work introduced a novel and simple method with which to effectively monitor sensitivity and stretchability at the same time. More importantly, the method could be applied to other material categories to further improve the performance.

Crack Analysis and Node Design Improvements for Polystyrene Outer Insulation System

2012 ◽  
Vol 174-177 ◽  
pp. 1273-1276
Author(s):  
Qi Shun Liu
Keyword(s):  
Surface Cracks ◽  
Exterior Wall ◽  
Detailed Structure ◽  
Insulation System ◽  
Practical Applications ◽  
Board Surface ◽  
Structure Treatment ◽  
Insulation Effect ◽  
Composite Wall ◽  
Wall System

As a new composite wall system, because of advanced structure, excellent polystyrene insulation board, insulation effect, light weight, the simple and flexible construction method and well adaptability, polystyrene insulation board thin coating of exterior wall thermal insulation technology is widely used in China. In practical applications, thermal bridges and the board surface cracks that caused by improper handling of deformation joints and detailed structure are the main problem of the technology. In this paper, many problems are analyzed such as the crack causes, the plates overlap and the node structure treatment, and also corresponding solutions are proposed.

Ocean Turbulent Mixing in Northern Bohai Strait, China

2013 ◽  
Author(s):  
Shu-xiu Liang ◽  
Zhao-chen Sun ◽  
Song-lin Han ◽  
Hong-qiang Yin ◽  
Bo Bai
Keyword(s):  
Turbulent Mixing ◽  
Yellow Sea ◽  
Dissipation Rate ◽  
Bohai Sea ◽  
Heat Dissipation ◽  
Strong Mixing ◽  
Observation Data ◽  
Diffusivity Coefficient ◽  
Division Line ◽  
Bohai Strait

The measurements of ocean microstructure through which ocean internal mixing mechanism is revealed are taken more often recently. Free-falling turbulence microstructure profiler TurboMAP-9 is used to take a field observation on the area of northern Bohai Strait. 13 stations distributed in Bohai Sea, Yellow Sea and the “division line” between them are measured. Turbulent mixing characteristics of northern Bohai Strait for different seasons are described by analyzing the observation data of ocean turbulence microstructure profile. The results show that the northern Bohai Strait is a strong mixing area during non-stratification period. Turbulent energy dissipation rate ε of winter is bigger than that of autumn and it is strongest near the bottom layers which is in the order of 10−5W/kg. Heat dissipation rate χθ is in the same order of 10−6–10−5°C2/s in autumn as ε and 2–3 orders smaller than ε in winter. Thermal diffusivity coefficient kθ is a little bigger than turbulent mixing rate kρ in autumn and 1–2 orders smaller than kρ in winter. Both the kρ and kθ along the “division line” of Bohai Sea and Yellow Sea are bigger than that of the Bohai Sea and Yellow Sea. Base on the measured data and the analysis, heat dissipation rate and thermal dispersion coefficient can change 2–3 orders in non-stratification seasons which should be paid much attention to, especially for ocean model parameterization and pollutant discharge modeling.

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