Vapor Condensation and Absorption of SO2 in Wet Flue Gas

2003 ◽  
Author(s):  
Li Jia ◽  
Xiaofeng Peng
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Flue Gas ◽  
Phase Interface ◽  
Vapor Condensation ◽  
High Mass ◽  
Condensation Process ◽  
Gas Mixture ◽  
Vapor Fraction ◽  
So2 Absorption

The convection-condensation heat transfer mechanism of the gas mixture and its influence on SO2 absorption were theoretically analyzed with vapor fraction of 8% to 28%. A modified film model of mass transfer in mixture gas and Nusselt theory were used to describe the characteristics of mass, momentum and energy transfer at the phase interface. The effects of the velocities induced by mass transfer (vapor condensation and SO2 absorption) were included in conducting governing equations. Vapor condensation improves the SO2 absorption in the wet flue gas. Vapor fraction in the gas mixture would alter the mechanism of heat transfer modes, single-phase convection or condensation. But for high mass fraction of vapor the SO2 absorption will be an important phenomenon in the condensation process. Another important factor influencing the SO2 absorption is the Re number of bulk flow of wet flue gas.

scholarly journals An Experimental Investigation of Water Vapor Condensation from Biofuel Flue Gas in a Model of Condenser, (1) Base Case: Local Heat Transfer without Water Injection

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 844
Author(s):  
Robertas Poškas ◽  
Arūnas Sirvydas ◽  
Vladislavas Kulkovas ◽  
Povilas Poškas
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Flue Gas ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Water Injection ◽  
Vapor Condensation ◽  
Base Case ◽  
Water Vapor Condensation ◽  
Condensing Heat Exchanger

Waste heat recovery from flue gas based on water vapor condensation is an important issue as the waste heat recovery significantly increases the efficiency of the thermal power units. General principles for designing of this type of heat exchangers are known rather well; however, investigations of the local characteristics necessary for the optimization of those heat exchangers are very limited. Investigations of water vapor condensation from biofuel flue gas in the model of a vertical condensing heat exchanger were performed without and with water injection into a calorimetric tube. During the base-case investigations, no water was injected into the calorimetric tube. The results showed that the humidity and the temperature of inlet flue gas have a significant effect on the local and average heat transfer. For some regimes, the initial part of the condensing heat exchanger was not effective in terms of heat transfer because there the flue gas was cooled by convection until its temperature reached the dew point temperature. The results also showed that, at higher Reynolds numbers, there was an increase in the length of the convection prevailing region. After that region, a sudden increase was observed in heat transfer due to water vapor condensation.

Diffusion Layer Theory for Turbulent Vapor Condensation With Noncondensable Gases

1993 ◽  
Vol 115 (4) ◽  
pp. 998-1003 ◽  
Author(s):  
P. F. Peterson ◽  
V. E. Schrock ◽  
T. Kageyama
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Mass Transfer ◽  
Vapor Condensation ◽  
Sensible Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Noncondensable Gas ◽  
Noncondensable Gases ◽  
Vertical Tubes

In turbulent condensation with noncondensable gas, a thin noncondensable layer accumulates and generates a diffusional resistance to condensation and sensible heat transfer. By expressing the driving potential for mass transfer as a difference in saturation temperatures and using appropriate thermodynamic relationships, here an effective “condensation” thermal conductivity is derived. With this formulation, experimental results for vertical tubes and plates demonstrate that condensation obeys the heat and mass transfer analogy, when condensation and sensible heat transfer are considered simultaneously. The sum of the condensation and sensible heat transfer coefficients becomes infinite at small gas concentrations, and approaches the sensible heat transfer coefficient at large concentrations. The “condensation” thermal conductivity is easily applied to engineering analysis, and the theory further demonstrates that condensation on large vertical surfaces is independent of the surface height.

The Effects of Gas Mixture Composition on the Mass Transfer and Individual Diffusion Coefficient in CH4-CO2-Light Oil Systems

2021 ◽  
Author(s):  
Taiyi Zheng ◽  
Yongcheng Luo ◽  
Yu Shi ◽  
Xiangui Liu ◽  
Zhengming Yang ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Mass Transfer Rate ◽  
Molar Fraction ◽  
High Mass ◽  
Gas Mixture ◽  
Light Oil ◽  
The Individual ◽  
Tight Formation

Abstract Limited CO2 resources considerably narrow down the field application of CO2 EOR for improving oil recovery in tight formation. Considering that CH4 and CO2 have similar EOR mechanisms, CH4, as a by-product of produced oil, is a relatively cost-efficient agent to be injected into the tight formation with CO2. In this work, experimental and mathematical methods are proposed to probe the effect of CH4 composition on the mass transfer between a CO2-CH4 gas mixture and crude oil collected from a tight oil reservoir. Experimentally, the pressure-decay tests for different CH4-CO2-light oil systems are conducted at a constant temperature in a pressure / volume / temperature (PVT) setup. Also, the gas mixtures’ compositions before and after the experiments are analyzed with gas chromatography to investigate the mass transfer of different components. Theoretically, mathematical formulations are developed to describe the mass transfer between the gas mixture and light oil based on translated Peng Robinson equation of state (PR-EOS), a real gas equation, and one-dimensional convection-diffusion equations. The individual diffusion coefficients of CH4 and CO2 as well as the concentrations distribution can be obtained by minimizing the deviation between the calculated pressure and the measured ones. The results indicate that the higher the content of CO2 in the initial gas phase, the faster the pressure drops are and less time it takes for the oil and gas phases to reach a stable pressure, which implies a high mass transfer rate with an increase in CO2 composition. In particular, the diffusion coefficient of CO2 is found to be about 2 times larger than that of CH4 the same composition condition. However, it is noted that the individual diffusion coefficients of CH4 or CO2 are not constants. A high molar fraction in the initial gas sample will lead to a large diffusion coefficient in different CH4-CO2-light oil systems.

The Sonic Limit in Sodium Heat Pipes

1973 ◽  
Vol 95 (2) ◽  
pp. 218-223 ◽  
Author(s):  
E. K. Levy ◽  
S. F. Chou
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Heat Pipes ◽  
Vapor Condensation ◽  
Condensation Process ◽  
Recombination Reaction ◽  
Condenser Section ◽  
Sonic Point ◽  
Limit Heat Transfer

The results of an analytical study of the vapor dissociation–recombination and homogeneous vapor condensation phenomena in sodium heat pipes are described. It is shown that neither the dissociation–recombination reaction nor the vapor condensation process has a large influence on the sonic-limit heat transfer rate. The single most important factor is shown to be the wall shear stress in the heat-pipe vapor passage. The friction effects control the location of the sonic point, determine if the flow in the condenser section will be subsonic or supersonic, and decrease the sonic-limit heat transfer rate to values which can be substantially lower than those which are predicted from inviscid analyses.

Effect of Polymer Coating on Vapor Condensation Heat Transfer

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Mete Budakli ◽  
Thamer Khalif Salem ◽  
Mehmet Arik ◽  
Barca Donmez ◽  
Yusuf Menceloglu
Keyword(s):  
Heat Transfer ◽  
Saturation Pressure ◽  
Copper Substrate ◽  
Copper Surface ◽  
Vapor Condensation ◽  
Condensation Heat Transfer ◽  
Condensation Process ◽  
Limiting Factor ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients

Abstract Condensation heat transfer coefficients (HTCs) are rather low compared to thin film evaporation. Therefore, it can be a limiting factor for designing heat transfer equipment. In this work, heat transfer characteristics of water vapor condensation phenomena were experimentally studied on a vertically aligned smooth copper substrate for a range of pressures and temperatures for two different liquid wettability conditions. The heat transfer performance is dominated by the phase change process at the solid–vapor interface along with the liquid formation mechanism. Compared to heat transfer results measured at an untreated copper surface, heat transport is augmented with a thin layer of perfluoro-silane coating over the same substrate. In this work, the effect of saturation pressure on the condensation process at both surfaces has been investigated by analyzing heat transfer coefficients. The results obtained experimentally show an increase in contact angle (CA) with the surface coating. A heat transfer augmentation of about 26% over uncoated surfaces was obtained and surfaces did not show any degradation after 40 h of operation. Finally, current results are compared with heat transfer values reported in open literature.

Analytical Modeling for Vapor Condensation in the Presence of Noncondensable Gas and Experimental Validation

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Wei Zhang ◽  
Suilin Wang ◽  
Mu Lianbo
Keyword(s):  
Heat Transfer ◽  
Film Thickness ◽  
Latent Heat ◽  
Flue Gas ◽  
Vertical Surface ◽  
Vapor Condensation ◽  
Condensation Heat Transfer ◽  
Wall Area ◽  
Cooling Surface ◽  
Applicable Range

Abstract The sensible and latent heat transfer are two essential considerations in investigating vapor condensation in the presence of noncondensable gases. In this paper, a new model for filmwise condensation heat transfer was developed using similarity-based solution. The expression of gas–liquid interfacial temperature, film thickness, and heat transfer coefficient were derived and calculated, respectively. The analytical results showed that the temperature difference between gas–liquid interfacial and cooling surface is decreased as there is an increase in cooling surface temperature. In addition, the forced-convective condensation heat transfer and film thickness on the vertical surface were experimentally carried out. The proportion of latent heat is 62–67% and relatively larger than sensible heat in the range of wall temperature (17–32.5 °C). The experimental film thickness is less than analytical film thickness by 2–10%. It is because that the liquid film may evaporate back to water vapor in the neighboring wall area due to high temperature of flue gas. Further, a new nondimensional correlation of condensation heat transfer of flue gas is fitted with Nu = 0.62Re0.5Ja0.67 and applicable range is Re = 1000–2500, Ja = 1.7–4.4. The fitting shows a good agreement between experimental and correlated values except some points in the low Nu number. The model proposed is applicable to predict the temperature and velocity distribution for condensation heat and mass transfer of multicomponent gases.

Modeling Pneumatic Conveyor Duct Wear: A New Approach

2005 ◽  
Author(s):  
Prem Chand ◽  
A. C. Saha ◽  
Prafull Chand
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Material Flow ◽  
Gas Flow ◽  
Gas Mixture ◽  
New Approach ◽  
Flow Phenomenon ◽  
Transfer Processes ◽  
Flow Through ◽  
Difficult Situations

It was shown in one of our recent works [1] that, the apparently disconnected items like solid-gas flow phenomenon, duct wear and particle degradation are in fact beautifully connected involving all the three components of transfer processes — heat transfer, mass transfer and momentum transfer. This paper which basically is an extension of our work on Fluid Energy Mill [2] aims at predicting duct wear while transporting solids-gas mixture in pneumatic conveyor even in most difficult situations like flow through bends under interference situation. The paper elaborates the methodology used for wear prediction and highlights the effect of several parameters like material flow rate etc. on the nature and extent of the duct wear.

Heat Transfer and Sublimation at a Stagnation Point in Potential Flow

1960 ◽  
Vol 27 (4) ◽  
pp. 613-616 ◽  
Author(s):  
W. W. Short
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Mass Transfer ◽  
Potential Flow ◽  
High Mass ◽  
Fluid Stream ◽  
Simple Analytical Expression ◽  
Transfer Rates ◽  
Transfer Data ◽  
Constant Thermal Conductivity

A simple analytical expression is derived which predicts the effect of mass transfer on countercurrent heat transfer to a vaporizing body. In this theory, the fluid stream is assumed to be inviscid and of constant thermal conductivity. The inviscid theory correlates well with heat-transfer data without mass transfer and is believed to predict heat-transfer rates fairly accurately at high mass-transfer rates.

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