scholarly journals Design to Build A Shallots Drying House with Fumigation in District Tanah Miring

2018 ◽  
Vol 1 (1) ◽  
pp. 28-34
Author(s):  
Indah Widanarti ◽  
Sunardi Sunardi ◽  
Ni luh Sri Suryaningsih
Keyword(s):  
Heat Transfer ◽  
Weight Loss ◽  
Convection Heat Transfer ◽  
Temperature Data ◽  
Heat Transfer Analysis ◽  
Small Scale ◽  
Test Results ◽  
Convection Heat ◽  
Fumigation Chamber ◽  
House Design

The purpose of this study was to make a simple shallots drying house design with fumigation so that dried shallots were obtained in accordance with the Standar Nasional Indonesia (SNI). The method used in this study is the temperature measurement in the smoke house. The benchmark in testing the smoking house is the temperature used in the room at the smoke house with the construction of a small scale permanent building. The temperature that shallots have to accept is 35-40oC.  Temperature data obtained from measurements at 3 observation points in the smoke house for heat transfer analysis. The test results on the design of the smoke house with a shelf design located 2 meters from the ground floor showed that convection heat transfer in the fumigation chamber was stable so as to produce dry shallots with a weight loss of 30%.

Particle Scale Heat Transfer Analysis in Rotary Kiln

2012 ◽  
Author(s):  
Amit Ravindra Amritkar ◽  
Danesh Tafti ◽  
Surya Deb
Keyword(s):  
Heat Transfer ◽  
Rotary Kiln ◽  
Granular Media ◽  
Particle Surface ◽  
Convection Heat Transfer ◽  
Heat Transfer Analysis ◽  
Convection Heat ◽  
Bed Temperature ◽  
Rotary Kilns ◽  
Pass Through

Rotary furnaces have multiple applications including calcination, pyrolysis, carburization, drying, etc. Heat transfer through granular media in rotary kilns is a complex phenomenon and plays an important role in the thermal efficiency of rotary furnaces. Thorough mixing of particles in a rotary kiln determines the bed temperature uniformity. Hence it is essential to understand the particle scale heat transfer modes through which the granular media temperature changes. In this study, numerical simulations are performed using coupled Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) to analyze heat transfer in a non-reacting rotary kiln. The microscopic models of particle-particle, particle-fluid, particle-surface and fluid-surface heat transfer are used in the analysis. The heat transfer simulations are validated against experimental data. The effect of particle cascading on the bed temperature is measured and contributions from various modes of particle scale heat transfer mechanisms are reported. Particles are heated near the rotary kiln walls by convection heat transfer as they pass through the thermal boundary layer of the heated fluid. These particles are transported to the center of the kiln where they transfer heat to the cooler particles in the core of the kiln and back to the cooler fluid at the center of the kiln. It is found that 90% of the heat transferred to particles from the kiln walls is a result of convection heat transfer, whereas only 10% of the total heat transfer is due to conduction from the kiln walls.

scholarly journals Convection Heat Transfer Analysis in a Channel with an Open Trapezoidal Cavity: Heat Source Locations effect

2020 ◽  
Vol 330 ◽  
pp. 01006
Author(s):  
F. Mebarek-Oudina ◽  
H. Laouira ◽  
A. Aissa ◽  
A. K. Hussein ◽  
M. El Ganaoui
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
The Other ◽  
Heat Transfer Analysis ◽  
Convection Heat ◽  
Nusselt Numbers ◽  
Discrete Heat Source ◽  
Trapezoidal Enclosure

In this work, a numerical study of mixed convection inside a horizontal channel with an open trapezoidal enclosure subjected to a discrete heat source in different locations is carried out. The heat source with the length of ε = 0.75, is maintained at a constant temperature. The air flow with a fixed velocity and a cold temperature enters the channel horizontally. The other walls of the enclosure and the channel are adiabatic. The results are presented in the form of the contours of velocity, isotherms and Nusselt numbers profiles for various heat source locations, Prandtl number (Pr = 0.71) and Reynolds number (Re = 100) respectively. The distribution of the isotherms depends significantly on the position of the heat source. We noted that the best heat transfer is detected where the heat source is placed in the top of the left .

A Modeling Analysis of Non-Melting Solid Fuel Particle Heating

2003 ◽  
Author(s):  
Ali A. Rostami ◽  
Susan E. Wrenn ◽  
Mohammad R. Hajaligol
Keyword(s):  
Heat Transfer ◽  
Weight Loss ◽  
Solid Particle ◽  
Convection Heat Transfer ◽  
Total Weight ◽  
Fuel Particle ◽  
Total Weight Loss ◽  
Convection Heat ◽  
Particle Heating ◽  
Internal Convection

The heating of fuel particles is generally the first step in the process of gasification or combustion of solid fuels such as coal and biomass. The particle heating that is achieved via combined convection and radiation effects requires a rigorous analysis of heat transfer within as well as outside of the particle, which makes the lumped capacity approximation unsuitable. A more adequate representation of the heating-up process requires the inclusion of the internal convection within the solid particle, the blowing effects on the particle surface, the spatial and temporal variations of the solid thermal conductivity as well as the heat of pyrolysis reactions. The internal convection tends to equalize the temperature distribution within the solid, while the blowing effect contributes to the boundary layer thickening and eventually to a reduction in the convection heat transfer to the particle. To include the above-mentioned effects, a kinetic model for the total weight loss of the solid material was coupled with the heating model. A simple first-order reaction model for the total weight loss was utilized in this study. For materials with high moisture contents, the heat of pyrolysis reactions is an important factor in the heating rate and non-uniform heating of the solid particle. Thermal equilibrium between the solid and evolved gases was assumed within the particle and the equations for the conservation of mass and energy were solved numerically. Results show that surface blowing which is due to the devolatilization of the particle tends to reduce the convection heat transfer from the hot gases to the particle. Internal convection contributes to thermal uniformity in the particle. Heat of pyrolysis reactions plays an important role in the heating profile of the particle. It delays the temperature rise of the particle until most of the volatile materials is released.

Force Convection Heat Transfer Analysis through Different Channel (Review Of Work)

2011 ◽  
Vol 3 (8) ◽  
pp. 256-258
Author(s):  
Pankaj Sonkusare ◽  
◽  
S. K. Dhakad S. K. Dhakad ◽  
Pravin Kumar Pravin Kumar ◽  
Sanjay Katarey ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Convection Heat Transfer ◽  
Force Convection ◽  
Heat Transfer Analysis ◽  
Convection Heat

Heat transfer analysis of supercritical methane on cooling channel of electromechanical actuator under various flight acceleration overloads

2021 ◽  
pp. 1-16
Author(s):  
Zhigang Gao ◽  
Jun Zhou ◽  
Tianhu Wang ◽  
Peng Li
Keyword(s):  
Heat Transfer ◽  
Secondary Flow ◽  
Convection Heat Transfer ◽  
Heat Transfer Analysis ◽  
Main Stream ◽  
Flight Vehicle ◽  
Cooling Channel ◽  
Convection Heat ◽  
Electromechanical Actuator ◽  
High Acceleration

Abstract The crucial distinction of heat transfer between the earth environment and the high-acceleration overloads of flight vehicle is the secondary flow resulting from the gravitational buoyancy force and centrifugal one, which influences the heat transfer of supercritical fluid significantly. Hence, in this work, the effect of various flight acceleration overloads on turbulent convection heat transfer in the cooling channel of flight vehicle electromechanical actuator is investigated numerically. The cooling channel is constructed from a helically coiled tube with an inner diameter of 8 mm, coil diameter of 74 mm, and screw pitch of 10 mm, the operation pressure covers the range of 5-9 MPa, and the gravity ranges from 1 g to 50 g. Based on this model, the heat transfer characteristics of supercritical methane in the cooling channel of flight vehicle electromechanical actuator under various acceleration overloads are studied, aiming to obtain a deep understanding of flow and heat transfer mechanism and thermal performance of supercritical methane in the cooling channel under the conditions of actual flight. The simulation result indicates that with the high-g overload, the heat transfer enhancement becomes obvious and the effect of secondary flow caused by the flight acceleration exhibits the non-negligible influence. The secondary flow caused by flight acceleration overloads disturbs the flow acceleration of the main stream that weakens the suppression of heat transfer. However, the effect of gravitational buoyancy does not dominate on forced convection heat transfer even under the high acceleration overload.

Inverse Heat Transfer Analysis of Grinding, Part 1: Methods

1996 ◽  
Vol 118 (1) ◽  
pp. 137-142 ◽  
Author(s):  
C. Guo ◽  
S. Malkin
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Convection Heat Transfer ◽  
Temperature Measurements ◽  
Heat Transfer Analysis ◽  
Estimation Accuracy ◽  
Convection Heat ◽  
Workpiece Surface ◽  
Inverse Heat Transfer ◽  
Accuracy And Stability

Thermal analyses of the grinding process generally require assumptions concerning the distributions of the heat flux to the workpiece within the grinding zone and convective cooling outside the grinding zone. The present work is concerned with the use of inverse heat transfer methods to estimate the heat flux and convection heat transfer coefficient distributions on the workpiece surface during straight surface grinding from temperature measurements within the workpiece. In the present paper, three inverse heat transfer methods are developed: temperature matching, integral, and sequential methods. Each method is evaluated for accuracy and stability using simulated temperature data. The selection of the sampling frequency of the temperature measurements and location of the temperature sensor are found to be critical for both estimation accuracy and stability. In a second paper, these inverse heat transfer methods are applied to estimate the distributions of the heat flux and convection heat transfer coefficients on the workpiece surface for grinding of steels with aluminum oxide and CBN abrasive wheels.

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