• Journal of Ocean Engineering and Technology
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• v.2 no.1
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• pp.176-182
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• 1988

The exergy analysis on the heat storage performance of the senible heat storage unit which consists of the heat storage material in the concentric annulus and the hot fluid flowing through the inner tube is performed. Heat transfer characteristics which are necessary for the performance of the exergy analysis is obtained from the energy balance equations and the second law of thermodynamics. As the index of heat storage performance, the exergy lossnumber $N_{s}$, and exergy storage ratio from the concepts of the second law of thermodynamics are defined. Results are ovtained for the grometry of the storage unit, the Biot number Bi, ambient temperature $T_{o}$ as parameters. From these results the exergy storage ratio can be considered as the efficiency of the hat storage unit and is introduced as a guide to design.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.301-306
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• 2018

Urbanization causes urban floods and urban heat island in the summer, so it is necessary to understanding the changes of the thermal environment through urban climate and energy balance. This can be explained by the energy balance, but in urban areas, unlike the typical energy balance, the storage heat flux saved in the building or artificial land cover should be considered. Since the environment of each city is different, there is a difficulty in applying the method of retrieving the storage heat flux of the previous research. Especially, most of the previous studies are focused on the overseas cities, so it is necessary to study the storage heat retrieval suitable for various land cover and building characteristics of the urban areas in Korea. Therefore, the object of this study, it is to derive the regression formula which can quantitatively retrieve the storage heat using the data of the area where various surface types exist. To this end, nonlinear regression analysis was performed using net radiation and surface temperature data as independent variables and flux tower based storage heat estimates as dependent variables. The retrieved regression coefficients were applied to each independent variable to derive the storage heat retrieval regression formula. As a result of time series analysis with flux tower based storage heat estimates, it was well simulated high peak at day time and the value at night. Moreover storage heat retrieved in this study was possible continuous retrieval than flux tower based storage heat estimates. As a result of scatter plot analysis, accuracy of retrieved storage heat was found to be significant at $50.14Wm^{-2}$ and bias $-0.94Wm^{-2}$.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.12 no.1
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• pp.179-214
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• 1999

The result were as follows: 1. Yu Wan So(劉完素) regarded the cause of surgical disease as the heat(熱). He used the three method to drain(疏通), promoting pus drainage(托裏) and the balance between ying-energy(營氣) and wei-energy(衛氣). 2. Jang Jong Jeung(張從正) only refered to medicines without entire theory. 3. Lee Dong Won(李東垣) regarded the cause of surgical disease as the greasy diet(膏梁厚味), damp air(濕氣), wetness heat(濕熱). For each treatment he used the method of Yu Wan So's treatment and emphasized the balance between ying-energy(營氣) and wei-energy(衛氣), stomach energy(胃氣). 4. Ju Jin Heung(朱震亨) distinguished the cause of surgical disease from enternal(內), external(外) and channel(經). For each treatment he used the method to drain(疏通), promoting pus drainage(托裏) and the balance between ying-energy(營氣) and wei-energy(衛氣). The first stage used the clearing away heat and toxic materials(淸熱解毒) and the last stage used the invigoration and dispersion(補托). 5. Yu Wan So(劉完素) used to be very busy of Moschus(麝香), Alumen(白礬), Olibanum(乳香), Coptidis Rhizoma(黃連), Minium(黃丹) and Scutel1ariae Radix(黃芩) In classification of the medical action, great part of the medicine are activating blood circulation to dissipate blood stasis(活血祛瘀), clearing away heat and toxic materials( 淸熱解毒) and external application(外用). 6. Jang Jong Jeung(張從正) used to be very busy of Olibanum(乳香), Angelicae Gigantis Radix(當歸), Minium(黃丹), Myrrha(沒藥), Calomelas(輕粉), Rhei Radix Et Rhizoma(大黃) and Phellodendri Cortex(黃柏). In classification of the medical action, great part of the medicine arc activating blood circulation to dissipate blood stasis(活血祛瘀), clearing away heat and toxic materials(淸熱解毒) and diverged wind-cold evil(發散風寒). 7. Lee Dong Won(李東垣) used to be very busy of Forsythiae Fructus(連翹), Scuteliariae Radix(黃芩), Angelicae Gigantis Radix(當歸). Astragali Radix(황기), Glycyrrhizae Radix(炙甘草), Bupleuri Radix(紫胡), Phellodendri Cortcx(黃柏), and Coptidis Rhizoma(黃連). In classification of the medical action, great part of the medicine are activating blood circulation to dissipate blood stasis(活血祛瘀), regulating vital energy(理氣) and clearing away heat and toxic materials(淸熱解毒). 8. Ju Jin Heung(朱震亨) used to be very busy of Glycyrrhizae Radix(甘草), Astragali Radix(황기), Angelicae Gigantis Radix(當歸), Phellodendri Cortex(黃柏), Scutellariae Radix(黃芩), Ginseng Radix(人蔘), Qlibanum(乳香). In classification of the medical action, great part of the medicine are clearing away heat and toxic materiaIs(淸熱解毒), activating blood circulation to dissipate blood stasis(活血祛瘀) and diverged wind-cold evil(發散風寒).

• Proceedings of the Korean Society of Crop Science Conference
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• 1989.05a
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• pp.30-31
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• 1989

• Atmosphere
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• v.24 no.4
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• pp.471-479
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• 2014

A road surface temperature prediction model (UM-Road) using input data of the Unified Model (UM) output and road physical properties is developed and verified with the use of the observed data at road weather information system. The UM outputs of air temperature, relative humidity, wind speed, downward shortwave radiation, net longwave radiation, precipitation and the road properties such as slope angles, albedo, thermal conductivity, heat capacity at maximum 7 depth are used. The net radiation is computed by a surface radiation energy balance, the ground heat flux at surface is estimated by a surface energy balance based on the Monin-Obukhov similarity, the ground heat transfer process is applied to predict the road surface temperature. If the observed road surface temperature exists, the simulated road surface temperature is corrected by mean bias during the last 24 hours. The developed UM-Road is verified using the observed data at road side for the period from 21 to 31 March 2013. It is found that the UM-Road simulates the diurnal trend and peak values of road surface temperature very well and the 50% (90%) of temperature difference lies within ${\pm}1.5^{\circ}C$ (${\pm}2.5^{\circ}C$) except for precipitation case.

• Journal of the Korean Solar Energy Society
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• v.27 no.1
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• pp.91-98
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• 2007

Perimeter zone is one of the weakest area in buildings and it makes an increase of heating and cooling loads, in addition to condensation or discomfort with cold-draft to residents in winter. Because of this, it needs to be reinforced by active systems. However, they use fossil fuel, and ultimately greenhouse effect is urged. Thus, we proposed BIPV system functioned as solar collector which can substitute active system. As an fundamental stage, heat balance equation in steady-state by Fortran was used not only, in winter for pre-heating effect and electric power capacity during the day, but also in summer, for the latter during the day and sky radiation effect during the night. Especially, we should have considered shading on PV by IES Suncast, since even a little bit of it makes the efficiency too low for the PV modules to work. As a result, in summer day, the PV panel should be tiled in 70 degrees to gain the most electric power. Moreover, we could verify that this model makes higher temperature and heat flux under 0.02 m/s. On the other hand, the PV had the high efficiency with high velocity because of cooling effect behind the PV. Therefore, we should regard the air current distribution later on.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.725-730
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• 2006

The purpose of this study is on the performance evaluation of horizontally installed GHEX(Geothermal Heat Exchanger, HGHEX) which has been operated for 5 years successfully. Followings are the results. Firstly, in summer season, on Aug. 2000, $33^{\circ}C$ water was flowing out from HGHEX with continuous operating method, and $27{\sim}29^{\circ}C$ with interval operating method on Jul. 2005. But $2.5{\sim}3.0^{\circ}C$ temperature differences are gained from HGHEX. Secondly, in winter season, on Nov. 2000, $25^{\circ}C$ water was flowing out from HGHEX with continuous operating method, and $13{\sim}15^{\circ}C$ with interval operating method on Jan. 2006. But with each operating method, only $0.1^{\circ}C$ and $0.7^{\circ}C$ temperature differences are gained from HGHEX respectively. As the conclusion of this study, at the point of continuos operating method, seasonal balance of heating and cooling loads, and at the point of interval operating method, balance for geothermal restoring time respectively must be considered for better system performances.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.953-958
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• 2006

Perimeter zone has been reinforced by active systems, such as fan-coil units, because it causes an increase in heating and cooling loads, dew condensation in winter, or discomfort with cold-draft to residents in buildings, through poor insulation by light-weighed skin due to progressing multi-storied buildings and skyscrapers. However, because these active systems raise Its capacity so that fossil fuel is used as much as they are added, and ultimately, greenhouse effect is urged, we proposed BIPV system functioned as solar collector which can substitute active system. As an early stage, heat balance equation in steady-state by Fortran was used not only for pre-heating effect and electric power capacity during the day in winter, but also for electric power capacity during day in slimmer and sky radiation effect during night in summer. Especially, we should have considered shading on PV, since even a little bit of it makes the efficiency too low for the PV to work. Still, when the flux of pre-heated air was increased to make air-barrier, its temperature was not enough to make it because the speed of heat exchange was too fast to warm up the air, thus the capacity to meet the condition was evaluated, and electric power from PV was made used for it.

• Atmosphere
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• v.22 no.4
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• pp.429-436
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• 2012

The performances of the Seoul National University Urban Canopy Model (SNUUCM) under different meteorological conditions (clear, cloudy, and rainy conditions) in summertime are compared using observation dataset obtained at an urban site. The daily-averaged net radiation, sensible heat flux, and storage heat flux are largest in clear days and smallest in rainy days, but the daily-averaged latent heat flux is similar among clear, cloudy, and rainy days. That is, the ratio of latent heat flux to net radiation increases in order of clear, cloudy, and rainy conditions. In general, the performance of the SNUUCM is better in clear days than in cloudy or rainy days. However, the performance in simulating sensible heat flux in clear days is as poor as that in rainy days. For all the meteorological conditions, the performance in simulating latent heat flux is worst among the performances in simulating net radiation, sensible heat flux, and latent heat flux. The normalized mean error for latent heat flux is largest in rainy days in which the relative importance of latent heat flux in the surface energy balance becomes greatest among the three conditions. This study suggests that improvements to the parameterization of processes that are related to latent heat flux are particularly needed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1548-1553
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• 2012

The important requirement for microgrid operation is to meet the balance between supply and demand. To meet, Combined Heat and Power (CHP) generation should be considered in microgrid scheduling. CHP generation is economical on the side of a consumer because it products heat and power. Therefore, it is high efficient. This paper presents a mathematical model for optimal microgrid operation including CHP generation using the optimal ratio of heat and power due to demand. The objective function and constraints are modeled by linear program (LP). Through the case study, the validation of the proposed model is shown.