scholarly journals Evaluation of Heat Transfer Coefficients During the Water Vapor Condensation Contained in the Flue Gas

2016 ◽  
Vol 110 ◽  
pp. 01007 ◽  
Author(s):  
Victor Bespalov ◽  
Vladimir Bespalov ◽  
Denis Melnikov
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Flue Gas ◽  
Vapor Condensation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Water Vapor Condensation

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.

Heat Exchangers for Cooling Boiler Flue Gas to Temperatures Below the Water Vapor Dewpoint

2011 ◽  
Author(s):  
Edward Levy ◽  
Harun Bilirgen ◽  
Michael Kessen ◽  
Daniel Hazell ◽  
Barbara Carney
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Flue Gas ◽  
Heat Exchangers ◽  
Buoyancy Force ◽  
Power Plants ◽  
Vapor Condensation ◽  
Water Vapor Condensation ◽  
Funded Project ◽  
Condensed Water

Coal-fired power plants have traditionally operated with stack temperatures in the 300°F range to minimize fouling and corrosion problems due to sulfuric acid condensation and to provide a buoyancy force to assist in the transport of flue gas up the stack. However, as an alternative, there would be benefits to cooling the flue gas to temperatures below the water vapor and acid dew points, while capturing the condensed water vapor. This paper describes experimental results from a DOE and industry-funded project to develop condensing heat exchangers for application to coal-fired power plants. A system of condensing heat exchangers was designed, fabricated and tested using slip streams of boiler flue gas and experiments were performed to measure the effects of process parameters on rates of heat transfer and water vapor condensation. In addition, measurements were made to characterize the acid concentrations in the condensed water which collected on the heat exchanger tubes and to quantify the effects of the heat exchangers on flue gas mercury concentrations.

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.

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.

Effect of substrate wettability and flexibility on the initial stage of water vapor condensation

Soft Matter ◽  
2019 ◽  
Vol 15 (48) ◽  
pp. 10055-10064
Author(s):  
Qi Che ◽  
Yongjun Lu ◽  
Fenghui Wang ◽  
Xiang Zhao
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Vapor Condensation ◽  
Transfer Efficiency ◽  
Heat Transfer Efficiency ◽  
Initial Stage ◽  
Water Vapor Condensation ◽  
Condensation Mode

The condensation mode and heat transfer efficiency are significantly affected by substrate wettability and flexibility in the initial stage of vapor condensation.

scholarly journals Roles of Flue Gas in Promoting Steam Flow and Heat Transfer in Multithermal Fluid Flooding

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Zhuangzhuang Wang ◽  
Zhaomin Li
Keyword(s):  
Heat Transfer ◽  
Flue Gas ◽  
Film Condensation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Flow And Heat Transfer ◽  
Steam Flooding ◽  
Heat Injection ◽  
The Heat Transfer Coefficient ◽  
Steam Heat

Multithermal fluid technology is becoming an important method in the field of heavy oil development. However, because of insufficient investigation on the heat transfer for the multithermal fluid, some development phenomena and characteristics still cannot be well explained. In order to determine the effect of flue gas on the thermal swept scope, multithermal fluid flooding experiments were carried out through 1D sandpack. The temperatures along the sandpack were measured. On this basis, steam heat transfer simulation experiments were conducted and the heat transfer coefficients were calculated. The mechanism of flue gas on steam heat transfer was analyzed. The results show that at the same heat injection conditions, the thermal swept scope for the multithermal fluid flooding was larger than that for the steam flooding. With the increase of flue gas proportion in the multithermal fluid, the heat transfer coefficient decreased and the condensation pattern was transformed from drop condensation to film condensation gradually. The flue gas can form gas film on the surface of the cold body and inhibit the heat transfer between steam and the cold body. Because of the inhibiting effect of flue gas on steam heat transfer, flue gas can reduce the heat transferred to the rock matrix in flooding and thus promote steam to carry more heat further. Meanwhile, flue gas can accelerate the flow of steam in porous media, which also leads to the expansion of the thermal swept scope for the multithermal fluid flooding.

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