• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.533-538
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• 2005

The number of domestic ice-rink is little by little increasing recently. Therefore, the demand for air-conditioning system to adjust adequately the indoor condition of ice-rink is constantly increasing. But, if air-conditioning system for ice-rink isn't designed properly, the problems such as fogging, ice surface condensation, structural deterioration, odors, generation of dew condensation on the surface of a wall occur. The solutions for these problems are to lower the relative humidify of indoor. The objectives of this paper is to apply of desiccant dehumidifier on ice-rink, solve these problems.

• KIEAE Journal
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• v.17 no.2
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• pp.5-12
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• 2017

Purpose: Under the purpose of presenting the adequate remodeling period for the improvement of thermal insulation performance of external walls in deteriorated buildings, the change in external wall and residential environment problem(dew condensation) due to aged deterioration after the apartments were constructed in Korea were analyzed. Method: Temperature Difference Ratio Outside(TDRo) and Heat Flow Meter(HFM) were used as measurement methods to evaluate the thermal insulation performance of deteriorated buildings. For TDR evaluation, thermo-graphic camera was used to measure and analyze the surface temperature of external wall. Also, dew condensation evaluation was analyzed using the Temperature Difference Ratio Inside(TDRi). Result: As a result of analyzing thermal performance through TDRo, the first decline point of thermal insulation performance began after 14-16 years have passed since construction was completed, and after 20 years have passed the decline point of thermal insulation performance reappeared. As a result of analyzing U-value with HFM measurement method, the decline rate of external wall's thermal insulation performance is lower than 2% in average at around 5 years after completion, and 8.7% in average at 10-15 years, and over 10.2% in average at 20 years.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.281-286
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• 2007

Road traffic accidents kill more than one million people a year. ESCC represents a new device, that hasn't any analogue. This embedded system, heats the car glasses, when it's needed, that makes more safety driving. It's build on Atmega128L CPU, using high-performance EEPROM CPLD ATF1504AS. Source code was written in C language. Algorithm of work was written by dew-point table. This system is not only clearing the glass from condensation, but averts condensation. ESCC began working, when input information became close to dew-point table information. Thankful this device, field of view is more widely, that increase safety level.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.4
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• pp.600-610
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• 1995

When combustion gas is cooled down below the dew point of sulfuric acid vapor in the heat recovery systems, condensation occurs. Since the condensed sulfuric acid solution causes low-temperature corrosion in materials, it is important to measure the SOx dew point by electric measurement. In this study, two kinds of probes having electric gaps of 1mm or 2mm were used. and experiments were carried out by the parameters of sulfuric acid vapor and water vapor concentration. The changes of electric current caused by sulfuric acid condensed on the surface of probe according to the cooling rate and the probe head surface temperature were sudied. The opimum cooling rate was decreased with the increasing of water vaper concentration regardless of sulfuric acid concentration. The sensitivity of electric current is improved for the narrower gap(1mm) of ring electrodes, but it rarely affects the SOx dew point measuring of different probes according to the change of cooling rate.

• Proceedings of the Korean Ceranic Society Conference
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• 2004.10a
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• pp.91-91
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• 2004

• Journal of Biosystems Engineering
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• v.41 no.2
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• pp.98-107
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• 2016

Purpose: The aim of this study was to find an appropriate polymer film, which could reduce the water condensation for pallet-size modified atmosphere packaging (MAP). Methods: Five different types of films were selected from several commercialized films. Prior to the real food storage test, plastic boxes with wetted plastic balls were used to simulate the high humidity conditions of real food storage. The initial MAP condition was 5% oxygen and 95% nitrogen, and the $O_2$ concentration, the relative humidity and water condensation inside the films were checked on a daily basis. The MAP test for tomatoes was conducted by using the most appropriate film from the five films examined in this study. Results: Every film except Mosspack(R) indicated a similar variation in the $O_2$ concentration over the course of time. The relative humidity near the surfaces of all the films except nylon-6 approached saturation conditions over time. For three kinds of films, namely, low-density polyethylene (LDPE) film, anti-fogging oriented polypropylene (AFOPP) film, and Mosspack(R), the inner surfaces of the films were fully covered with dew after a storage period of a day. Conversely, an area of 4.5% was covered with dew in the case of the poly lactic acid (PLA) film, and there was no dew inside the nylon-6 film. The pallet-size MAP test for tomatoes was conducted by using the nylon-6 film and there was no water condensation inside the nylon-6 film over three weeks of storage. Conclusions: During the pallet scale MAP, water condensation could cause severe fungal infection and wetting of the corrugated box. Hence, it was important to minimize water condensation. This study showed that the MAP films with high WVTR such as nylon-6 and PLA could reduce the water condensation inside the pallet scale MAP.

• Corrosion Science and Technology
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• v.22 no.5
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• pp.351-358
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• 2023

Although many thermal power plants use heat recovery systems, high exhaust gas temperatures are maintained due to corrosion at dew points and ash deposits caused by condensate formation. The dew point of exhaust gas is primarily determined by the concentration of SO₃ and steam, and various experiments and calculation equations have been employed to estimate it. However, these methods are known to be less suitable for exhaust gases with low SO₃ concentrations. Therefore, in this study, since the temperature of the exhaust gas is expected to decrease due to the low-load operation of the coal-fired power plant, sulfuric acid condensation and low-temperature corrosion are anticipated. We aimed to conduct a quantitative evaluation to propose ways to prevent damage by limiting operating conditions and improving facilities. The experimental results showed that the corrosion rate increased linearly with rising temperatures at a certain sulfuric acid concentration. Furthermore, variations in sulfuric acid concentrations generated during the current power plant operation process did not significantly affect the dew point, and the dew point of sulfuric acid under these conditions was observed to be between 120 - 130 ℃.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.496-502
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• 2015

Hydrocarbon dew point(HCDP), a property which is the most generally used for describing natural gas condensation, is a very important parameter of natural gas quality specifications. HCDP is strongly influenced by the concentration of the heavier hydrocarbon components, especially $C_6+$, so, along with compliance with gas quality specifications, build up of procedures for obtaining accurate HCDP is essential for gas transmission company, because hydrocarbon condensation present may cause serious operational and safety problems. This study has been carried out in an attempt to measure HCDP accurately by the automatic hydrocarbon dew point meter under the actual field conditions. Measured HCDP also has been compared with calculated HCDP using the composition determined by gas chromatograph and industry accepted equation of state at multiple pressures, along with the cricondentherm. The test results are 1) the automatic hydrocarbon dew point meter was able to measure stable HCDP continuously 2) the automatic hydrocarbon dew point meter has been performed reference measurement by pure propane with a known dew point from literature, and 3) A meaningful differences was observed when comparing the automatic hydrocarbon dew point meter and gas chromatograph results for synthetic standard gas mixtures and real gas mixtures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.17-18
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• 2012

Moisture condensation leading to defects that occur repeatedly in the winter, and recognize the same method, the problem of the other buildings in the same area again and again, a vicious cycle that occurs due to the temporary lack of systematic research and processing way of coping has been recurring. In this study, as warming progresses, more inside the air-conditioned summer season due to an increase in the ambient temperature of the condensation phenomenon to happen about summer wall condensation phenomena are expected to analyze the case of a building to prevent condensation and for insulation designs are proposed.

• KIEAE Journal
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• v.17 no.4
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• pp.89-94
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• 2017

Purpose: Condensation in walk-in closets attached to apartment bathroom has been known as an emerging issue that may threat occupants' comfort and health. Despite a number of design guidelines and enforcements to prevent condensation, condensation issues may still occur depending on various cases and scenarios. We aim to identify what condensation scenarios may lead to walk-in closet condensation and/or worse the existing condensation issues. Method: First we choose an actual walk-in closet of an apartment that suffers from sporadic condensation and resulting mold and mildew. Then we observe its relative humidity and temperature after the bathroom is used, in which excessive vapor is thought to be transported to the walk-in closet. We analyze Temperature Difference Ratio - a domestic indicator of condensation occurrence, and dew point temperature to compare it with surface temperature using 2D heat transfer simulation upon various condensation scenarios. Result: TDR of the test walk-in closet turns out be OK despite mold and mildew actually occurring. Hot water pipe installed in the floor would greatly reduce condensation. If hot water pipe in the upper floor, however, is not used, or hot water pipe of the closet is turned off during swing seasons, it is expected that condensations may still occur.