• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.4
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• pp.456-465
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• 1998

Effect of a non-absorbable gas on the absorption process in a vertical tube absorber was investigated numerically. The water vapor mined with air as the non-absorbable gas is absorbed into LiBr/water solution film. The flow is assumed to be laminar and fully developed in both liquid and gas phases. The diffusion and energy equations were solved in both phases to give the temperature and concentrations, from which heat and mass fluxes were determined. It was shown that the local absorption rate decreases as the mass fraction of air in water vapor increases. The vapor pressure of water at the liquid-vapor interface reduces significantly since the non-absorbable gas is accumulated near the interface. The effect of non-absorbable gases on absorption rate becomes larger as the mass flow rate of the vapor decreases. For small amount of non-absorbable gases the total absorption rate of water vapor increases as the mass flow rate of the vapor decreases. Total absorption rate increases as the mass flow rate of the vapor increases for large concentration of non-absorbables at the inlet of an absorber.

• International Journal of Air-Conditioning and Refrigeration
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• v.7
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• pp.69-78
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• 1999

Effects of a non-absorbable gas on the absorption process in a vertical tube absorber has been investigated numerically. The water vapor mixed with air is absorbed into LiBr/water solution film. The flow is assumed to be laminar and fully developed in both liquid and gas phases. The diffusion and energy equations were solved in both phases to give the temperature and concentrations, from which heat and mass fluxes were determined. The local absorption rate has been shown to decrease as the mass fraction of air in the water vapor increases. The vapor pressure of water at the liquid-vapor is interface reduced significantly since the non-absorbable gas accumulates near the interface. The effects of non-absorbable gases on absorption rate become larger as the mass flow rate of the vapor decreases. For a small amount of non-absorbable gases, the total absorption rate of water vapor increases as the mass flow rate of the vapor decreases. The total absorption rate increases as the mass flow rate of the vapor increases for large concentrations of non-absorbable gases at the inlet of an absorber.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.537-544
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• 1998

We selected Spathiyhyllum patinii and Pachira aqkatica, since the former has high O3 absorption while the latter low absorption, and analyzed physiological factors such as diffusive coefficient, transpiration rate, photosynthetic rate, and CO2 absorption rate, which affected O3 absorption capacity There was significant relationship between gas absorption capacity and the other factors; photosynthetic rate, diffusive resistance, stomatal resistance and CO2 absorption rate. Therefore model formula for estimation of O3 absorption rate in plant was formulated by making use of these factors. There was difference for the estimation of O3 absorption rate according to plant species. In case of Spathiphyllum patinii, photosynthetic rate is an optimal factor for estimation of O3 absorption capacity. On the other hand, stomatal resistance and diffusive resistance are optimal factors of Pachira aquatica among various physiological ones. And we knew that CO2 absorption rate is a potential factor to evaluate gas absorption capacity regardless of plant species. But considering efficiency and practicality, diffusive resistance was the most effective factor for the estimation of O3 gas absorption.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.2
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• pp.332-337
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• 2004

The use of gas absorption refrigeration machine has considerably increased because of the shortage of the electric power in the summer and the regulation of freon refrigerant. Gas absorption refrigeration machine consists of a condenser, a heat exchanger. supplying pipes, a radiator etc, This system is likely to be corroded by acid. dissolved oxygen and gases, Cavitation erosion-corrosion by flow velocity of cooling water may happen in absorption refrigeration machine. In these cases. erosion and corrosion occur simultaneously. Then, it makes a serious damage with synergy effect. Therefore, this paper was studied on the cavitation damage of cupronickel(70/30) tube for gas absorption refrigeration machine, In the $30^{\circ}C$ tap water, linear polarization test and anodic polarization test were carried out for copper(C1220T-OL) and cupronickel(70/30) tube. Also, cavitation erosion-corrosion behavior of cupronickel (70/30) tube was considered, The main results are as following: (1) In the linear test, the corrosion current density of cupronickel(70/30) is higher than that of copper. (2) The erosion-corrosion rate of cupronickel(70/30) displayed later tendency than that of copper by vibratory cavitation in cooling water. (3) In cooling water, the progress mechanism of erosion-corrosion rate of copper and cupronickel(70/30) follows a pattern of incubation, acceleration, attenuation and a steady state period.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.97-103
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• 2006

This work forcus on the development of gas sensor that measure the concentrations of exhaust gas using diode laser. Each diode laser for exhaust gas measurement is set to work at near-IR using both DA and WMS methods. Also use of fiber-coupled optical elements makes such a sensor rugged and easy to align. On-line data acquisition and processing can be performed with a PC running LabVIEW software, and absorption signals are measured simultaneously by multiplexing method. Finally, It were experimentally compared WMS (Wavelength Modulation Spectroscopy) with DA (Direct Absorption) for the accuracy.

• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.197-202
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• 2007

This research was basically carried out to extend the application of $CO_2$ absorption processes for flue-gas system, which are mainly applied to a reforming process in petro-chemical industries. In general, MEA absorbent has some problems in flue-gas treatment, such as, degradation, regeneration energy and absorption capacities. As we known, sterical hindered amine, typically AMP (2-amino 2-methyl 1-propanol), have a good potential to improve these problems. In this paper, the characteristics of $CO_2$ absorption in aqueous AMP solution were measured and compared with that of MEA. It has been found that the $CO_2$ absorption capacity in AMP is double than that of MEA in the low $CO_2$ partial pressure system such as flue-gas. Also, the equilibriums of $CO_2$-AMP system were partially suggested, which are essentially needed to design the absorption process.

• Journal of the Korea Society of Computer and Information
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• v.25 no.2
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• pp.189-195
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• 2020

In this study, the inlet duct and guide vane of the gas floating absorption tower were redesigned to improve the desulfurization efficiency so that the exhaust gas can be uniformly introduced into the absorption tower. In order to reduce the sulfur oxide pollutants among the main sources of air pollutants in industrial boilers, the existing equipment is redesigned and solved. For this purpose, change the exhaust gas, the slurry and recycling the adsorbent to improve the removal efficiency of SOx component in the exhaust gas inside the gas floating absorption tower so as to uniformly contact. And the initial design value and CFD value for the pressure loss from the boiler outlet to the gas floating absorption tower outlet are verified. Also, the velocity distribution of the exhaust gas, the concentration distribution of the recycled adsorbent, the liquid slurry behavior, and the pressure loss were compared. The results confirmed that the desulfurization efficiency was improved because the pressure loss from the boiler outlet to the absorption tower outlet was reduced and the deflection of the exhaust gas was minimized.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.121-130
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• 1986

Using the sbsorption coefficients and the weighting factors of the gray gas, the total emissivities of C $O_{2}$- $H_{2}$O and C $O_{2}$- $H_{2}$O- transient species-soot gas mixtures can be expressed by the following equation, [a numerical formula] Where, $a_{i}$ and $K_{i}$ represent the weighting factor and the absorption coeffient of i-gray gas respectively; L is the pathlength of the gas. This equation is widely used for the analyses of the radiation heat transfer in the combustors of internal combustion engines and in the furnace of external combustion engines. In this work, a simple calculation model of the weighting factor and the absorption coeffient of the above equation was developed. The weighting factors and the absorption coefficients of combustion products were calculated by applying the model to various kinds of fossil fuels such as coal and heavy oil. Then, the computed total emissivities for each fuel and pathlength were compared with measured and calculated values which have been already published in the literatures. The followings were the results obtained through the comparisons between the calculated emissivites and the published values; the developed model for the calculations of the weighting factor and the absorption coefficient of C $O_{2}$- $H_{2}$O and C $O_{2}$- $H_{2}$O- transient species-soot gas mixtures could be applied over the wide ranges of the temperature and the pathlength; the errors between the total emissivities calculted and the values published were maximum 10%, and average 1%, respectively.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2325-2332
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• 2012

A series $[C_3Omim]$[X] of imidazolium cation-based ILs, with ether functional group on the alkyl side-chain have been synthesized and structure of the materials were confirmed by various techniques like $^1H$, $^{13}C$ NMR spectroscopy, MS-ESI, FTIR spectroscopy and EA. More specifically, the influence of changing the anion with same cation is carried out. The absorption capacity of $CO_2$ for ILs were evaluated at 30 and $50^{\circ}C$ at ambient pressure (0-1.6 bar). Ether functionalized ILs shows significantly high absorption capacity for $CO_2$. In general, the $CO_2$ absorption capacity of ILs increased with a rise in pressure and decreased when temperature was raised. The obtained results showed that absorption capacity reached about 0.9 mol $CO_2$ per mol of IL at $30^{\circ}C$. The most probable mechanism of interaction of $CO_2$ with ILs were investigated using FTIR spectroscopy, $^{13}C$ NMR spectroscopy and result shows that the absorption of $CO_2$ in ether functionalized ILs is a chemical process. The $CO_2$ absorption results and detailed study indicates the predominance of 1:1 mechanism, where the $CO_2$ reacts with one IL to form a carbamic acid. The $CO_2$ absorption capacity of ILs for different anions follows the trend: $BF_4$ < DCA < $PF_6$ < TfO < $Tf_2N$. Moreover, the as-synthesized ILs is selective, thermally stable, long life operational and can be recycled at a temperature of $70^{\circ}C$ or under vacuum and can be used repeatedly.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.9 s.114
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• pp.964-970
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• 2006

Micro gas turbine(MGT) has received attention recently as small-scale distributed power sources. With characteristics such as their small size, lightweight, low maintenance cost and minimal vibrations during operation, they are expected to become widespread in a wide range of ' applications, including residential and small-scale industrial use. It is very easier to start-up and stop the MGT system which is the friendly environmental power system has just below the 9ppm NOx emmission and good quality of noise level. The exhaust heat emitted by the MGT is in the form of about $300^{\circ}C$ clean exhaust gas. The exhaust gas is suitable for absorption chiller/heater system. 1 has researched performance characteristics of the 60 kW class MGT-absorption chiller-heater system in the local condition. Variations of heat recovery from exhaust gas has measured according to micro gas turbine output of 15, 30, 45, 60kW. From those results, the performance of the MGT-absorption chiller/heater system has been evaluated.