Parametric study of evaporative heat transfer coefficient in solar distillation

1997 ◽  
Vol 18 (4) ◽  
pp. 205-215 ◽  
Author(s):  
S. Kumar ◽  
G. N. Tiwari ◽  
S. Suneja ◽  
S. N. Rai
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Parametric Study ◽  
Solar Distillation ◽  
Evaporative Heat Transfer ◽  
Evaporative Heat Transfer Coefficient

Evaporative Heat Transfer Analysis of a Heat Pipe With Hybrid Axial Groove

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Lizhan Bai ◽  
Guiping Lin ◽  
G. P. Peterson
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Liquid Film ◽  
Transfer Coefficient ◽  
Flow Resistance ◽  
Heat Pipes ◽  
Low Flow ◽  
Circular Channel ◽  
Evaporative Heat Transfer ◽  
Evaporative Heat Transfer Coefficient

Through the application of thin film evaporation theory and the fundamental operating principles of heat pipes, a hybrid axial groove has been developed that can greatly enhance the performance characteristics of conventional heat pipes. This hybrid axial groove is composed of a V-shaped channel connected with a circular channel through a very narrow longitudinal slot. During the operation, the V-shaped channel can provide high capillary pressure to drive the fluid flow and still maintain a large evaporative heat transfer coefficient. The large circular channel serves as the main path for the condensate return from the condenser to the evaporator and results in a very low flow resistance. The combination of a high evaporative heat transfer coefficient and a low flow resistance results in considerable enhancement in the heat transport capability of conventional heat pipes. In the present work, a detailed mathematical model for the evaporative heat transfer of a single groove has been established based on the conservation principles for mass, momentum and energy, and the modeling results quantitatively verify that this particular configuration has an enhanced evaporative heat transfer performance compared with that of conventional rectangular groove, due to the considerable reduction in the liquid film thickness and a corresponding increase in the evaporative heat transfer area in both the evaporating liquid film region and the meniscus region.

scholarly journals FORCED CONVECTION DRYING OF INDIAN GROUNDNUT: AN EXPERIMENTAL STUDY

2017 ◽  
Vol 15 (3) ◽  
pp. 467
Author(s):  
Ravinder Kumar Sahdev ◽  
Mahesh Kumar ◽  
Ashwani Kumar Dhingra
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Forced Convection ◽  
Experimental Error ◽  
Linear Regression Analysis ◽  
Convective Heat Transfer Coefficient ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Evaporative Heat Transfer

In this paper, convective and evaporative heat transfer coefficients of the Indian groundnut were computed under indoor forced convection drying (IFCD) mode. The groundnuts were dried as a single thin layer with the help of a laboratory dryer till the optimum safe moisture storage level of 8 – 10%. The experimental data were used to determine the values of experimental constants C and n in the Nusselt number expression by a simple linear regression analysis and consequently, the convective heat transfer coefficient (CHTC) was determined. The values of CHTC were used to calculate the evaporative heat transfer coefficient (EHTC). The average values of CHTC and EHTC were found to be 2.48 W/m2 oC and 35.08 W/m2 oC, respectively. The experimental error in terms of percent uncertainty was also estimated. The experimental error in terms of percent uncertainty was found to be 42.55%. The error bars for convective and evaporative heat transfer coefficients are also shown for the groundnut drying under IFCD condition.

scholarly journals Analysis Effects of Average Value of Convective and Evaporative Heat Transfer Coefficient on Solar Cabinet Dryer for Reduction of Mass of Papad

2021 ◽  
Vol 9 (12) ◽  
pp. 1511-1523
Author(s):  
Goldi Mathuriya
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Forced Convection ◽  
Linear Regression Analysis ◽  
Transfer Coefficients ◽  
Average Value ◽  
Heat Transfer Coefficients ◽  
Mass Transfer Phenomenon ◽  
Evaporative Heat Transfer

Abstract: In this research paper, the behavior of heat and mass transfer phenomenon during greenhouse papad drying under forced convection mode has been investigated. Various experiments were performed during the month of April 2020 at SRCEM Banmore, morena (26o 34’13” N 78o 10’48” E). Experimental data obtained for forced convection greenhouse drying of papad were used to determine the constants in the Nusselt number expression by using the simple linear regression analysis and, consequently, the values of convective and evaporative heat transfer coefficients were evaluated. The average values of experimental constants C and n were determined as 0.9714 and 0.0129 respectively. The average values of convective and evaporative heat transfer coefficients were determined as 0.0886 W/m2 oC and 6.7583 W/m2 oC respectively. The experimental error in terms of percentage uncertainty was also evaluated. Keywords: Papad, Papad drying, Heat transfer coefficient, Convective, Evaporative, Forced convection greenhouse

Evaporative Heat Transfer Experiment of Air-Water Bubbly Flow

2003 ◽  
Author(s):  
Qinghua Chen ◽  
R. S. Amano ◽  
Linli Zhou ◽  
Yi Hou
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Water Film ◽  
Air Bubbles ◽  
Sieve Plate ◽  
Transfer Experiment ◽  
Evaporative Heat Transfer ◽  
The Heat Transfer Coefficient

In this paper, a new kind of evaporative heat transfer experiment for the cooling process of coolers/condensers is conducted. The design of the test coils is immersed in an airwater bubbling layer. The air-water two-phase flow passes through the tubes of the coils. Due to the motion of the air bubbles in the water, a thin water film forms on the surface of the tube. As the air bubbles pass by the tube this water film is evaporated into the air. The tubes of coil reject heat to the water film, and the evaporation of the water film rejects heat to the air bubble stream. This heat transfer mode significantly increases the heat transfer coefficient between tubes and air. The consumption of the power of a water pump can be decreased. Moreover, the airflow rate required is less than that of an aircooled condenser. The pressure drop of air through air-water bubbling layer and the heat transfer between the tube and water are experimentally investigated in this paper. The results show that the factors affecting the pressure drop and the heat transfer coefficient involve the pore geometry of sieve plate, the height of the air-water bubbling layer, the air flow rate through the sieve plate and the heat flux of tubes. The heat transfer coefficient between tube and water is two times larger than that of falling film of water on the outer surface of tube.

scholarly journals Mathematical modelling of heat and mass transfer in a roof type solar distillation system

2021 ◽  
Vol 40 (2) ◽  
pp. 261-268
Author(s):  
F. Onoroh ◽  
S.S. Folorunsho ◽  
M. Ogbonnaya ◽  
U.P. Onochie
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Practical Significance ◽  
System A ◽  
Solar Distillation ◽  
Proposed Model ◽  
Distillation System ◽  
Perform Sensitivity Analysis ◽  
The Heat Transfer Coefficient

This research examined the performance of a roof type solar distillation system. A model was developed that captured the influence of the cover angle on still performance in terms of evaluating the heat transfer coefficient, yield and efficiency. The previous models of evaluating these matric has been shown to be unsatisfactory due to over prediction. The objectives are to clarify the misconception on the efficiency, to validate the derived expression for the Nusselt’s number of condensation under an inclined surface and to perform sensitivity analysis on the dimensionless parameters with derived models. The derived model has a practical significance because it provides much information on the dependence of the heat transfer coefficient on the cover angle. The model was solved with MATLAB, and results show a well correlated trends with the established work of literature and the proposed model having the lest efficiency as the model is without the over prediction inherent in other models due to non-inclusion of evaporation in the analysis of free convection of air. The peak yield of all the models occurs at about 11:00 AM, with the proposed model having a peak yield of about 0.045kg.

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