• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.88.1-88.1
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• 2010

In recent days, the study for the renewable energy is required to supplement traditional energy source. One of the renewable energy of Fuel Cell is classified according to the electrolytes. It is the MCFC (Molten Carbonate Fuel Cell) for this study. One of the equipments of the heat exchangers is important component for efficiency and cost. In MCFC system, several heat exchangers are used according to the application. It is named for the humidifier because it is to preheat the fuel and water so that a reactor will convert some of the incoming fuel to hydrogen. Then, hot side fluid service is used the exhausted gas from the fuel cell and cold side fluid service is the fuel and water. The operation temperature range is about 25~500 Celsius Degree. This heat exchanger has the problems of heat transfer considering to multiphase fluid and phase changing. So it is necessary to analyze the heat transfer characteristics and to propose the reasonable design methodology for the humidifier. In this study, the thermal characteristic for the humidifier is estimated by using commercial tool of heat exchanger design and rating. And this study provides the testing methodology and presents the results for test facility of fabrication and for testing.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.8
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• pp.613-620
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• 2014

A few Humidifier have vibration problems caused by velocity of flow, piping vibration and karman vortex. The crack is generated on pipe wall and humidifier are damaged. Vibration analysis is conducted to prevent pipe damage during the design. But the other problem are caused after analysis of vibration. Therefore in this paper, the vibration and static analysis have been measured and analyzed for pipes and curve. Also modal test is conducted for analysis of natural frequency.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.1
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• pp.42-47
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• 2014

Adequate relative humidity is needed in the common living space, for human health, and industrial space, for maintenance and efficiency. Evaporative humidifier systems generally have slow response tendencies of air loads, but relatively low initial investment and maintenance costs. Humidification efficiency in the evaporative humidifier is dependent mostly on the shapes and arrays of humidifying modules. So, we tried to apply the computational fluid dynamics to the evaporative humidifier systems, and studied the humidification efficiency of evaporative humidifiers, through the outlet air conditions.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.720-724
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• 2008

The purpose of this study is to evaluate the PM10 removal efficiencies of an Air-washer and an Ultrasonic humidifier by mock-up experiments. The concentrations of PM10 were measured at 5 minute intervals using $\beta$-Ray method. The average PM10 removal efficiency of the Air-washer was 79.8%, while the PM10 concentrations increased with the operation of Ultrasonic humidifier. In the case of operating the Air-washer, the R.H(Relative Humidity) level of the test room was maintained at around 45%, regardless of initial R.H condition. The R.H of the test room with Ultrasonic humidifier was influenced by the initial R.H condition.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.2
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• pp.111-116
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• 2010

In this study, the structural analysis was performed to optimize the membrane humidifier with hollow fiber membrane for polymer electrolyte membrane fuel cell system. The main design factors were considered by evaluating the humidifying performance according to various structural parameters such as packing density and length. The effects of operation conditions of membrane humidifier were also elucidated experimentally. Results imply that there are optimum points for the packing density and length of humidifier. It was also found that among operation conditions, relative humidity of wet exhaust gas and temperature of dry inlet gas have major effects on the humidifying performance.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.78.2-78.2
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• 2010

Effect of temperature elevation of inlet air on performance of a membrane humidifier for PEMFC vehicle application was investigated both experimentally and numerically. A shell-and-tube typed gas-to-gas humidifier with Nafion membrane was tested. The experimental result showed that water transfer varies nonlinearly with the temperature elevation. Numerical analysis based on detailed modeling is also conducted on a single tube geometry to explain this nonlinear behavior. The simulation revealed that the local water flux varies nolineary and dramatically along the tube. Analysis is based on competing role of temperature increase and relative humidity decrease, both of which seriously affect water conductivity of the membrane.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.14.1-14.4
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• 2016

A total of 221 patients were evaluated to be humidifier disinfectant associated with lung injury (HDLI) through two rounds of programs through April 2015. The humidifier disinfectant (HD) brands most often associated with HDLI were found to be Oxy (n=151, 68 %) and Cefu (n=26, 17 %). Polyhexamethylene guanidine used for disinfectant for four types of HD brands including Oxy was found to be associated with the highest number of HDLI cases (n=188). Further programs are operating to identify various health effects including lung injury which may be associated with the use of HD. Not only national agencies, but also pertinent environmental health societies should cooperate in the necessary investigations so that this tragedy can be properly addressed and future incidents concerning chemicals and chemical-containing products can be prevented.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2011.05a
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• pp.43-44
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• 2011

• Journal of Environmental Health Sciences
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• v.46 no.4
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• pp.457-469
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• 2020

Objective: This study was designed to estimate the precise nationwide number of those who used humidifier disinfectants (HDs) and experienced specific health effects, including death, due to exposure to HDs in Korea between 1994 and 2011. Methods: A total of 5,000 households (15,472 people) were surveyed by stratifying the sample with a design that is equivalent to nationally approved household systematic sampling and face-to-face interviews from October 16, 2019 to December 30, 2019. Results: The proportion of use of humidifier disinfectants at home was 18.4% (2,844/15,472 people) and the proportion of those who experienced health effects among those who were exposed to HDs was 10.7% (303/2,844 people). Based on these factors, it was estimated that 8.94 million people (95% CI=8.25-9.63 million) were exposed to HDs and 0.95 million people (95% CI=0.87-1.02 million) experienced health effects, which means almost one in five and one in fifty Koreans respectively. The estimated number of deaths from HDs were 20,366 people (95% CI=18,801-21,931). Conclusion: The survey was large and analyzed a representative sample across the country, so this estimation of the nationwide population exposed and at risk to HDs is more accurate and reliable than previous studies. However, it is necessary to confirm whether results similar to those of this study can be reproduced through a survey using a cross-sectional survey at the national level. In particular, a survey focused on death cases is needed.

• Toxicological Research
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• v.28 no.2
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• pp.103-106
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• 2012

The effect of continuous humidifier use on the bioaerosol concentration in an indoor environment was investigated. An ultrasonic humidifier was operated for 10 hr per day for 15 days in an apartment room. During this time period, viable bioaerosol samples were taken using a single-stage Andersen sampler containing culture media plates for bacteria and fungi. The culture plates were then incubated at room temperature for 2~7 days depending on the media. The counts for the air sample plates were corrected for multiple impactions using the positive hole conversion method and are reported as the colony forming units per cubic meter of air (CFU/$m^3$). While the bacterial concentration measured using the tryptic soy agar (TSA) did not show any significant change during the first 3 days, the concentration increased from the $6^{th}$ day (6979 CFU/$m^3$) and reached a maximum on the $9^{th}$ day (46431 CFU/$m^3$). The concentration then decreased to 2470 CFU/$m^3$ on the $12^{th}$ day, at which point the fungal concentration increased rapidly to 14424~16038 CFU/$m^3$. Also, while the fungal concentration showed a significant change until the $9^{th}$ day of humidifier use, fungal growth was observed on the wallpaper and increased rapidly from the $12^{th}$ day. However, the bacterial concentration increased rapidly after the fungi were removed by remediation. The major fungal species identified in the samples were Penicillium representing 34%, Aspergillus representing 31%, Cladosporium representing 24%, and Alternaria representing 1%. The results also indicated that a relative humidity over 80% was easily achieved with continuous humidifier use. Yet, maintaining a high humidity in a room can cause a rapid outbreak of microbial growth.