Measurement of Internal Temperature Distribution in PEMFCs by Nondestructive Inverse Method

2005 ◽  
Author(s):  
Mei-Hsia Chang ◽  
Chin-Hsiang Cheng
Keyword(s):  
Temperature Distribution ◽  
Outer Surface ◽  
Inverse Method ◽  
Initial Guess ◽  
Temperature Data ◽  
Membrane Electrode ◽  
Measured Temperature ◽  
Internal Temperature ◽  
Temperature Prediction ◽  
End Plate

A nondestructive inverse method is developed to determine the internal temperature distribution of PEMFCs. In this study, attention is focused on global measurement for the irregular temperature distribution at the interface between the carbon plate and the membrane electrode assembly (MEA) based on the measured temperature data on the outer surface of the end plate. In this report, a concept of point-by-point temperature prediction is adopted. This approach is particularly suitable for determining an irregular temperature distribution that is difficult to handle by the existing polynomial-function approach [1]. A number of test cases are considered in this study. Three irregular temperature functions are specified and regarded as exact temperature distributions for testing the performance of the approach. Influence of the uncertainties of the measured temperature data on the outer surface and the number of the temperature prediction points (NX×NY) on the end plate surface is evaluated. In addition, the effects of the initial guess on the uniqueness of the predictions are also investigated.

Study on Temperature Prediction Model of Asphalt Concrete Pavement

2011 ◽  
Vol 243-249 ◽  
pp. 506-509
Author(s):  
Yuan Xun Zheng ◽  
Ying Chun Cai ◽  
Ya Min Zhang
Keyword(s):  
Asphalt Concrete ◽  
Prediction Models ◽  
Asphalt Pavement ◽  
Temperature Data ◽  
Measured Temperature ◽  
Temperature Prediction ◽  
Distribution Laws ◽  
Pavement Temperature ◽  
Asphalt Concrete Pavement ◽  
Excellent Accuracy

This study presents a kind of new model correlates air and pavement temperatures in bituminous pavement. Based on abundant measured temperature data in Henan Province, China, distribution laws in asphalt conctete pavement temperature is studied detailed and the dependency between air and pavement temperature is discussed by the method of regression analysis and the prediction models of asphalt pavement temperature are established. Comparisons between measured and predicted asphalt pavement temperatures indicate that the models are equipped with comprehensive applicability and excellent accuracy.

Error in Temperature Measurements Due to Conduction Along the Sensor Leads

1976 ◽  
Vol 98 (3) ◽  
pp. 491-495 ◽  
Author(s):  
B. S. Singh ◽  
A. Dybbs
Keyword(s):  
Temperature Distribution ◽  
The Body ◽  
True Temperature ◽  
Measured Temperature ◽  
Internal Temperature ◽  
Sensing Element ◽  
First Approximation ◽  
Immersion Thermocouple ◽  
Thermocouple Wire ◽  
Good Agreement

When a sensor is embedded in a solid body to measure its internal temperature, any conduction to, or from, its sensing element may cause the indicated temperature to be different from the true temperature. This paper describes an analysis of the error caused by conduction when there is an arbitrary temperature distribution in thebbody along the sensor. The sensor is modeled as a cylindrical fin and the appropriate conduction equation is solved. The solution gives a correction for the error which depends on such parameters as, depth of immersion, thermocouple wire and insulation properties, contact between the sensor and the body, and temperature distribution in the body. The latter may not be known, but the measured temperature distribution can be used as a first approximation. The corrected value can then be used to obtain a better estimate of the error. The results show good agreement with experimental observations.

Temperature Distribution in Mechanically Stabilized Earth Wall Soil Backfills for Design Under Elevated Temperature Conditions

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Andrew M. Kasozi ◽  
Raj V. Siddharthan ◽  
Rajib Mahamud
Keyword(s):  
Las Vegas ◽  
Temperature Data ◽  
Measured Temperature ◽  
Mechanically Stabilized Earth ◽  
Ansys Fluent ◽  
Design Procedures ◽  
Model Predictions ◽  
Mse Wall ◽  
Mechanically Stabilized Earth Wall ◽  
Mechanically Stabilized

Two-dimensional (2D) transient numerical thermal modeling was undertaken using ansys fluent v12.1 software to estimate distribution of soil backfill temperatures in a typical mechanically stabilized earth (MSE) wall. The modeling was calibrated using field-measured temperature data from the Tanque-Verde MSE wall in Tucson, Arizona (AZ) in which computed temperature data were found to be within ±5% of the field data. The calibrated model predictions for Las Vegas, Nevada (NV) showed an overall average soil backfill temperature of 34.3 °C relative to a maximum outside surface temperature of 51.6 °C. Such a high average soil backfill temperature calls for modification of design procedures since conventional designs are based on geosynthetic tensile strength determined at 20 °C.

Embedded resistive heating in composite scarf repairs

2016 ◽  
Vol 51 (18) ◽  
pp. 2575-2583 ◽  
Author(s):  
Mahdi Ashrafi ◽  
Brandon P Smith ◽  
Santosh Devasia ◽  
Mark E Tuttle
Keyword(s):  
Temperature Distribution ◽  
Outer Surface ◽  
Thermal Gradient ◽  
Thermal Damage ◽  
Electrical Current ◽  
Tensile Tests ◽  
Resistance Heating ◽  
Uniform Temperature ◽  
Uniform Temperature Distribution ◽  
Bond Strengths

Composite scarf repairs were cured using heat generated by passing an electrical current through a woven graphite-epoxy prepreg embedded in the bondline. Resistance heating using the embedded prepreg resulted in a more uniform temperature distribution in the bondline while preventing any potential thermal damage to the surface of the scarf repairs. In contrast, conventional surface heating methods such as heat blankets or heat lamps lead to large through thickness thermal gradient that causes non-uniform temperature in the bondline and overheating the outer surface adjacent to the heater. Composite scarf repair specimens were created using the proposed embedded heating approach and through the use of a heat blanket for circular and rectangular scarf configurations. Tensile tests were performed for rectangular scarf specimens, and it was shown that the bond strengths of all specimens were found to be comparable. The proposed embedded curing technique results in bond strengths that equal or exceed those achieved with external heating and avoids overheating the surface of the scarf repairs.

scholarly journals A Method for Reconstruction of Boiler Combustion Temperature Field Based on Acoustic Tomography

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yuhui Wu ◽  
Xinzhi Zhou ◽  
Li Zhao ◽  
Chenlong Dong ◽  
Hailin Wang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Optimal Parameter ◽  
Interpolation Method ◽  
Least Square Method ◽  
Reconstruction Algorithm ◽  
Least Square ◽  
Temperature Fields ◽  
Acoustic Tomography ◽  
Measured Temperature

Acoustic tomography (AT), as a noninvasive temperature measurement method, can achieve temperature field measurement in harsh environments. In order to achieve the measurement of the temperature distribution in the furnace and improve the accuracy of AT reconstruction, a temperature field reconstruction algorithm based on the radial basis function (RBF) interpolation method optimized by the evaluation function (EF-RBFI for short) is proposed. Based on a small amount of temperature data obtained by the least square method (LSM), the RBF is used for interpolation. And, the functional relationship between the parameter of RBF and the root-mean-square (RMS) error of the reconstruction results is established in this paper, which serves as the objective function for the effect evaluation, so as to determine the optimal parameter of RBF. The detailed temperature description of the entire measured temperature field is finally established. Through the reconstruction of three different types of temperature fields provided by Dongfang Boiler Works, the results and error analysis show that the EF-RBFI algorithm can describe the temperature distribution information of the measured combustion area globally and is able to reconstruct the temperature field with high precision.

scholarly journals Thermal management evaluation of the complex electro-optical system

2017 ◽  
Vol 21 (5) ◽  
pp. 2189-2196
Author(s):  
Srecko Nijemcevic ◽  
Milan Tasic ◽  
Branko Livada ◽  
Dragana Peric ◽  
Marko Tasic
Keyword(s):  
Temperature Distribution ◽  
Thermal Management ◽  
Optical System ◽  
Life Time ◽  
System Optimization ◽  
Working Environment ◽  
Outdoor Environment ◽  
System Component ◽  
Catastrophic Failure ◽  
Internal Temperature

The thermal management of a complex electro-optical system aimed for outdoor application is challenging task due to the requirement of having an air-sealed enclosure, harsh working environment, and an additional thermal load generated by sunlight. It is essential to consider the effect of heating loads in the system components, as well as the internal temperature distribution, that can have influence on the system life expectancy, operational readiness and parameters, and possibility for catastrophic failure. The main objective of this paper is to analyze internal temperature distribution and evaluate its influence on system component operation capability. The electro-optical system simplified model was defined and related thermal balance simulation model based on Solid Works thermal analysis module was set and applied for temperature distribution calculation. Various outdoor environment scenarios were compared to evaluate system temperature distribution and evaluate its influence on system operation, reliability, and life time in application environment. This work was done during the design process as a part of the electro-optical system optimization. The results show that temperature distribution will not be cause for catastrophic failure and malfunction operation during operation in the expected environment.

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