• Proceedings of the KSRS Conference
• /
• 1999.11a
• /
• pp.231-236
• /
• 1999

Accurate ocean surface fluxes with high resolution are critical for understanding a mechanism of global climate. However, it is difficult to derive those fluxes by using ocean observation data because the number of ocean observation data is extremely small and the distribution is inhomogeneous. On the other hand. satellite data are characterized by the high density, the high resolution and the homogeneity. Therefore, it can be considered that we obtain accurate ocean surface by using satellite data. Recently we constructed ocean surface data sets mainly using satellite data. The data set is named by Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO). Here, we introduce J-OFURO. The data set includes shortwave radiation, longwave radiation, latent heat flux, sensible heat flux, and momentum flux etc. Moreover, sea surface dynamic topography data are included in the data set. Radiation data sets covers western Pacific and eastern Indian Ocean because we use a Japanese geostationally satellite (GMS) to estimate radiation fluxes. On the other hand, turbulent heat fluxes are globally estimated. The constructed data sets are used and shows the effectiveness for many scientific studies.

• Journal of Environmental Science International
• /
• v.23 no.10
• /
• pp.1731-1743
• /
• 2014

The time variations in relative humidity observed at the Gangjeong (Goryeong) Reservoir in the Nakdong River over a one-year period (September 2012-August 2013) were analyzed with the Bowen ratio. The thermal vertical scale of the reservoir was also evaluated following Yamamoto's method. The study's results showed that the relative humidity at the reservoir was higher than that of the Daegu Meteorological Observatory (inland) all year round. The difference was slightly larger at nighttime (17-20 %) than at daytime (13-15 %) in all seasons except summer. The quantitative order of latent heat flux was summer, spring, autumn, and winter. This finding signifies that the thermal vertical scale of the reservoir corresponds to that of a shallow lake. The Bowen ratio was smallest at midday of the summer season. In other words, the net radiation energy was converted more as latent heat flux than sensible heat flux during a higher temperature period.

• Journal of the Korean Institute of Gas
• /
• v.11 no.3
• /
• pp.19-25
• /
• 2007

The heat transfer phenomena in a coil-typed LPG vaporizer with a hot water bath employed an electrical heating system were experimentally analyzed. The heat energy is initially used to sensible heat region to heat LPG and then is done to latent heat region to vaporize LPG and to heat up the vaporized gas. A two-phase flow region could be found from periodic temperature fluctuations, and only sensible heat effect was found after passing through the region. The overall heat capacity was defined as multiplying the overall heat transfer coefficient by the heat transfer area and we found a correlation employing the heating water temperature and LPG flow rate. The results of this work can effectively be applied for the design of field scale LPG vaporizers in the near future because they can predict the features of heat transfer on a kind of coil type LPG vaporizer.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.5
• /
• pp.535-540
• /
• 2003

Based on the monthly weather report of Korea Meteorological Administration (KMA) and daily sea surface temperature (SST) data from National Fisheries Research and Development Institute (NFRDl) (1991-2001), mean heat fluxes were estimated at the Gunsan harbor Net heat flux was transported from the air to the sea surface during March to early September, and it amounts to $125\;Wm^{-2}$ in average daily during May to June. During the middle of September to February, the transfer of net heat flux was conversed from the sea surface to the air with $-125\;Wm^{-2}$ in mininum value in October. Short wave radiation was ranged from 50 to $248\;Wm^{-2}$ showing maxima in April to June. Long wave radiation was ranged from 25 to $92\;Wm^{-2}$ with mininum value in June to July. Sensible heat flux denoting negative values in April to August was ranged from -30 to $72\;Wm^{-2}.$ Latent heat flux was ranged from 15 to $82\;Wm^{-2}$ with maxima in August to September. The phase of heat exchange was changed from cooling to heating in the end of February, and from heating to cooling In the beginning of September. The advective term of heat flux showed minima in April to June and maxima in November. The ratio of temperature variations was 1.37 in the sea surface process and the horizontal process by advection. This indicates that the main factor in variation of temperature at Gunsan harbor is the heat exchange process through the sea surface from the air.

• Journal of Environmental Science International
• /
• v.18 no.1
• /
• pp.33-39
• /
• 2009

Based on the monthly weather report of Korea Meteorological Administration (KMA) and daily sea surface temperature (SST) data from National Fisheries Research and Development Institute (NFRDI) in 2006, heat budget was estimated at Gampo in the eastern coast of Korea, the region occuring the cold water known as upwelling in summer. Net heat flux was transported from the air to the sea surface during February to November, and it amounts to $345Wm^{-2}$ in monthly mean value. During December to January, the transfer of net heat flux was conversed from the sea surface to the air with $-56Wm^{-2}$ in minimum of monthly mean value in January. Long wave radiation was ranged from $6Wm^{-2}\;to\;106Wm^{-2}$. Sensible heat was varied from $-36Wm^{-2}$(June) to $61Wm^{-2}$(February) and showed negative values from April to August. Latent heat showed $20Wm^{-2}$(July) with its minimum in July and $49Wm^{-2}$ with its maximum in March in monthly mean value. The annual mean of net heat flux is $129Wm^{-2}$, giving an annual heat surplus of $22Wm^{-2}$. Thus, during summer, the upwelled cold water at Gampo, appears to compensate the heat gain. However the ways in which these compensations are accomplished remains to be clarified.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.2
• /
• pp.128-136
• /
• 2008

It is necessary to estimate the cooling load of the next day for effective control of ice thermal storage system. In this paper, new methodology is proposed to estimate the cooling load using design parameters of building and predicted weather data. Only six input parameters such as sensible heat coefficient and constant, latent heat coefficient and constant, maximum and minimum temperature are necessary to obtain hourly distribution of cooling load for the next day. Two benchmarking buildings(hospital and research institute) are selected to validate the performance of the proposed method, and the estimated cooling loads in hourly and daily bases are calculated and compared with the measured data for E hospital. The estimated results show fairly good agreement with the measured data for both buildings.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.414-418
• /
• 2008

The effects of paper properties such as density, air permeability, water vapor transmission rate on the thermal performance of plate-type enthalpy exchanger were experimentally investigated. Three enthalpy exchanger samples having different properties were made, and were tested according to the standard test procedure (KS B 6879). Effective efficiencies were defined, which accounted for the air leakage between supply and exhaust streams. Results showed that paper density affected the sensible heat transfer of the samples. Sensible heat transfer increased with density of the paper. It was also shown that water vapor transmission rate alone was not a proper indicator for the efficiency of latent heat transfer. Air permeability should also be considered for adequate evaluation of the latent heat transfer. Best performance was obtained for the sample having highest paper density and moderate water vapor transmission ratio.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.19 no.10
• /
• pp.687-694
• /
• 2007

Cycle simulation is peformed for two types of the desiccant cooling system incorporating a regenerative evaporative cooler. The cooling capacity and COP are evaluated at various effectiveness values of the regenerative evaporative cooler, the desiccant rotor and the sensible heat exchanger. As either of the effectiveness of the regenerative evaporative cooler or the humidity effectiveness of the desiccant rotor increases, both the cooling capacity and COP increase, but the enthalpy leak ratio gives the opposite effect on the system performance. It is found that COP of cycle A mainly depends on the humidity effectiveness of the desiccant rotor, while for cycle B enthalpy leak ratio of desiccant rotor has the major impact on COP. The effect of the sensible heat exchanger on the cooling capacity is small about 1/10 compared with those of other components.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.12
• /
• pp.1756-1765
• /
• 2001

The heat and mass transfer process between the falling liquid desiccant(TEG) film and the air in counter flow at the dehumidifier of desiccant cooling system were investigated. The governing equations with appropriate boundary and interfacial conditions describing the physical problems were solved by numerical analysis. As a result, the effects of the design parameters and the outside air conditions on the rates of dehumidification and sensible cooling were discussed. The results of the dehumidification and sensible cooling rates were compared with those of the cross flow at the same conditions.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.16 no.6
• /
• pp.613-619
• /
• 1987

In a room air conditioning cooling system, if the room-sensible-heat-factor as plotted on a Psychrometric Chart intersects the saturation curve below the apparatus leaving air dewpoint, reheat must be used to maintain the design room air conditions. However, if the design room humidity is permitted to be raised to some degree, the cooling system will not require reheat as a new room-sensible-heat-factor line is developed between the apparatus leaving air dew-Point and the adjusted design room air conddition point. The advantages to this are the cost of reheat equipment and operation can be avoided. The cycle of this system can be shown on a Psychrometric Chart to plot the design condition points.