Experimental study of gas–solid overall heat transfer coefficient in vertical tank for sinter waste heat recovery

2016 ◽  
Vol 95 ◽  
pp. 136-142 ◽  
Author(s):  
Junsheng Feng ◽  
Hui Dong ◽  
Jianye Gao ◽  
Jingyu Liu ◽  
Kai Liang
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Overall Heat Transfer Coefficient

scholarly journals Design of Flue Gas-Air Heat Exchanger for Regeneration of Desiccant System

2018 ◽  
Vol 225 ◽  
pp. 05006 ◽  
Author(s):  
Shaymaa H. Abdulmalek ◽  
Hussain H. Al-Kayiem ◽  
Aklilu T. Baheta ◽  
Ali A. Gitan
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Waste Heat ◽  
Thermal Characteristics ◽  
Tube Diameter ◽  
Fuel Gas ◽  
Overall Heat Transfer Coefficient ◽  
Heat Exchanger Design

Heat recovering from biogas waste energy requires robust heat exchanger design. This paper presents the design of fuel gas-air heat exchanger (FGAHE) for recovering waste heat from biogas burning to regenerate desiccant material. Mathematical model was built to design the FGAHE based on logarithmic mean temperature difference (LMTD) and staggered tube bank heat transfer correlations. MATLAB code was developed to solve the algorithm based on overall heat transfer coefficient iteration technique. The effect on tube diameter on design and thermal characteristics of FGAHE is investigated. The results revealed that the smaller tube diameter leads to smaller heat transfer area and tube. On the other hand, the overall heat transfer coefficient and Nusselt numbers have larger rates at smaller tube diameter. In conclusion, the nominated tube diameter for FGAHE is the smaller diameter of 0.0127 m due to the high thermal performance.

scholarly journals Duplicating Freshwater Productivity of Adsorption Desalination System Using Aluminum Metal Filings

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3231
Author(s):  
Hesham Alhumade ◽  
Ahmed Askalany ◽  
Hegazy Rezk ◽  
Abdulrahim A. Al-Zahrani ◽  
Sharif F. Zaman
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Silica Gel ◽  
Heat Recovery ◽  
Water Productivity ◽  
Worst Case ◽  
Overall Heat Transfer Coefficient ◽  
Daily Water ◽  
Metal Additives

In this paper, improving the overall heat transfer coefficient by adding aluminum species to silica gel has been studied theoretically. An adsorption desalination system is proposed, and a lumped theoretical model conducted to investigate employing the metal additives within the adsorbent bed with and without a heat recovery between condenser and evaporator. A 30% of the total mass of the adsorbent bed contents was considered to be replaced by aluminum species. According to this, the overall heat transfer coefficient has been increased by 260%, which shows a good impact on the performance of the adsorption system. Daily water productivity was increased by 70% at the worst-case, reaching up to 17 m3/day/ton of silica gel without heat recovery. By employing heat recovery with the metal filing, the daily water productivity reached 42 m3/day/ton of silica gel which is four times the productivity of the classic silica gel-based adsorption desalination system.

Algal Biomass Harvesting Using Low-Grade Waste Heat: Evaluation of Overall Heat Transfer Coefficient in a Heat Exchanger

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Temesgen Garoma ◽  
Ramin E. Yazdi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Nusselt Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Waste Heat ◽  
Low Grade ◽  
Cfd Analysis ◽  
Overall Heat Transfer Coefficient ◽  
Nusselt Number Correlation

Abstract This study is part of a broader study on a novel method for harvesting algae by evaporation, and it investigated the feasibility of heating algal biomass using low-grade waste heat in a heat exchanger. Computational fluid dynamic (CFD) analysis was performed with ansysfluent, and the results were verified with experiments. The results of CFD analysis showed the overall heat transfer coefficient increased by 4, 13, and 100% as inlet gas temperature increased from 150 to 245 °C, liquid mass flow rate increased from 1.82 to 9.1 g/s, and gas mass flow increased from 2.2 to 13.2 g/s, respectively. It was also observed the overall heat transfer coefficient was not significantly affected with variations of properties of the liquid (thermal conductivity, density, and viscosity), thermal conductivity of the tube wall, and thickness of the tube banks, but it was sensitive to thermal conductivity of the gas. The experimental data were analyzed with logarithmic mean temperature difference (LMTD), number of transfer units (NTU), and Nusselt number correlation methods. There was an excellent agreement between the overall heat transfer coefficient calculated with the LMTD and NTU methods. The coefficients calculated with the LMTD method and Nusselt number correlation exhibited slight variations. This is likely because the LMTD is a theoretical method covering all experimental conditions and material properties, but Nusselt number correlation is an empirical approach based on correlations. The overall heat transfer coefficient calculated by CFD was slightly overestimated because the CFD analysis assumed complete insulation.

An Experimental Performance Evaluation of a Disk and Doughnut Type Heat Exchanger

1984 ◽  
Vol 106 (4) ◽  
pp. 759-765 ◽  
Author(s):  
K. P. Goyal ◽  
B. K. Gupta
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Surface Roughness ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Shell Surface ◽  
Flow Rates ◽  
Experimental Performance ◽  
Overall Heat Transfer Coefficient

This paper reports the results of an experimental study in which 158-mm-dia disk and doughnut type 1-2 oil coolers were tested for various combinations of flow rates and clearances between the doughnut baffle and the shell. Oil coolers of 45 L per minute capacity were tested at the diametral clearances of 0.6 mm, 0.87 mm, and 1.25 mm between the doughnut baffle and shell for various flow rates of oil and water. It is found that the decrease in overall heat transfer coefficient with increasing clearance is not significant for most practical purposes. In another series of tests, oil coolers of 90 L per minute capacity with shell surface roughnesses of 4 and 19 microns and diametral clearances of 0.07 mm, 0.33 mm, and 0.59 mm were tested. The experimental results indicate that in this range of low clearances, the overall heat transfer coefficient increases with increasing clearance and surface roughness.

Sign in / Sign up

Export Citation Format

Share Document