scholarly journals Analysis of temperature distribution in a pipe with inner mineral deposit

2014 ◽  
Vol 35 (2) ◽  
pp. 37-49
Author(s):  
Magda Joachimiak ◽  
Michał Ciałkowski ◽  
Jarosław Bartoszewicz
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Mineral Deposit ◽  
Mineral Deposits ◽  
Heat Conduction Coefficient ◽  
Temperature Distributions

Abstract The paper presents the results of calculations related to determination of temperature distributions in a steel pipe of a heat exchanger taking into account inner mineral deposits. Calculations have been carried out for silicate-based scale being characterized by a low heat transfer coefficient. Deposits of the lowest values of heat conduction coefficient are particularly impactful on the strength of thermally loaded elements. In the analysis the location of the thermocouple and the imperfection of its installation were taken into account. The paper presents the influence of determination accuracy of the heat flux on the pipe external wall on temperature distribution. The influence of the heat flux disturbance value on the thickness of deposit has also been analyzed.

Research on the Inversion of Equivalent Surface Heat Transfer Coefficient of Mass Concrete by Calculating its Heat Flux

2012 ◽  
Vol 188 ◽  
pp. 264-269
Author(s):  
Li Xin Qu ◽  
Yi Hong Zhou ◽  
Yao Ying Huang ◽  
Guo Qing Tang ◽  
Shao Wu Zhou
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Optical Fiber ◽  
Transfer Coefficient ◽  
Surface Heat ◽  
Mass Concrete ◽  
Surface Heat Transfer Coefficient ◽  
The Heat Transfer Coefficient

Most of the cracks on concrete dam are external ones, while external heat preservation is an important measure to prevent cracking. In order to obtain the actual thermal parameters, according to thermal conduction theory and the temperature distribution conditions of optical fiber on concrete surface, the surface temperature distribution of concrete pouring deck was real-time monitored by setting optical fiber in different depths; then the surface heat flux of mass concrete was calculated, thereby the equivalent surface heat transfer coefficient, which varied as time goes, was inversed. It is indicated that the inversion process is relatively simple and reliable, and the heat transfer coefficient obtained can well reflect the real performance of the insulation materials. Meanwhile, it is also indicated that the heat transfer coefficient of equivalent surface varies as time goes, which can contribute to back analysis calculation and actual engineering practice.

A New Truly Meshless Method for Heat Conduction in Solid Structures

2010 ◽  
Author(s):  
Eisa Ahmadi ◽  
M. M. Aghdam ◽  
Nasrin Sheikhy
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Meshless Method ◽  
Numerical Results ◽  
Micromechanical Modeling ◽  
Matrix Interface ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

In this study a new meshless method is presented for the analysis of heat transfer in heterogeneous solid structures. The presented meshless method is based on the integral form of energy equation for the sub-particles in the domain of the material. A micromechanical model based on the presented meshless method is presented for analysis of heat transfer, temperature distribution and steady-state effective thermal conductivities of fiber-matrix type of composite materials. Because the domain integration is eliminated in the presented meshless formulation, the computational efforts in presented method are decreased substantially. A small area of the composite system called the representative volume element (RVE) is considered as the solution domain. The fully bonded fiber-matrix interface is considered and contact thermal resistant is neglected in the fiber-matrix interface and so the continuity of temperature and reciprocity of heat flux is satisfied in the fiber-matrix interface. A direct interpolation method is employed for enforcement the appropriate boundary conditions to the RVE. Numerical results are presented for temperature distribution, heat flux and thermal conductivity. Numerical results show that presented meshless method is simple, effective, accurate and less costly method in micromechanical modeling of heat conduction in heterogeneous materials.

Hyperbolic Heat Conduction Equation for Materials With a Nonhomogeneous Inner Structure

1990 ◽  
Vol 112 (3) ◽  
pp. 555-560 ◽  
Author(s):  
W. Kaminski
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Conduction ◽  
Physical Meaning ◽  
Heat Conduction Equation ◽  
Hyperbolic Heat Conduction ◽  
Temperature Profiles ◽  
Using Data ◽  
Penetration Time

The physical meaning of the constant τ in Cattaneo and Vernotte’s equation for materials with a nonhomogeneous inner structure has been considered. An experimental determination of the constant τ has been proposed and some values for selected products have been given. The range of differences in the description of heat transfer by parabolic and hyperbolic heat conduction equations has been discussed. Penetration time, heat flux, and temperature profiles have been taken into account using data from the literature and our experimental and calculated results.

Application of Inverse Heat Conduction Method and Method of Lines in Spray Cooling of Heated Surface

2016 ◽  
Author(s):  
Ramin Soujoudi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Heat Conduction ◽  
Transfer Coefficient ◽  
Heated Surface ◽  
Method Of Lines ◽  
Spray Cooling ◽  
Approximation Technique ◽  
Inverse Heat Conduction

This paper investigates application of Method of Lines (MOL) and Inverse Heat Conduction techniques in spray cooling process. A flat face of a heated cylinder is cooled by using a nozzle spray and using room temperature water as a cooling fluid. The numerical analysis is done using MOL to estimate exposed surface temperature, surface heat flux, and convection heat transfer coefficient [3],[4]. Since there is no exact solution to verify the approximation result, for the verification purpose and accuracy of the result, the numerical result from this study is compared to other approximation results with experimental research done by Chen-Lee and Qiao-Chandra [1]. The results illustrate that disparity between the outcome of MOL and the one generated by Chen and Lee’s raw data is very insignificant throughout the whole time domain. This discrepancy between these two estimated results proves that MOL is a very reliable approximation technique compared to other finite element methods which require a finer mesh size and significant amount of calculations[2],[5]. However, comparing the results obtained through MOL with Qiao and Chandra shows that the difference between the estimated heat transfer coefficient and estimated heat flux converges rapidly for the short times of 0 < t < 60, but as the time passes, the MOL approximation results diverge slowly until it reaches its maximum value at ninety seconds, and the variance remains almost constant for the rest of the time period.

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