• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.5
• /
• pp.334-341
• /
• 2011

In the present study, optimal heat supply algorithm which minimize the heat loss through the distribution pipe line in group energy apartment was developed. Variation of heating load of group energy apartment building in accord with the outdoor air temperature was predicted by the heating load-outdoor temperature correlation. Supply water temperature and mass flow rate were controlled to minimize the heat loss through distribution pipe line. District heating apartment building located in Hwaseong city, which has 1,473 households, was selected as the object building for testing the present heat supply a1gorithm. Compared to the previous heat supply system, 10.4% heat loss reduction can be accomplished by employing the present method.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.11a
• /
• pp.234-235
• /
• 2021

We set the representative balcony types of the existed building to two types: unexpanded balcony and extended balcony, and analyze the effect of reducing the cooling and heating energy load when applying remodeling. The scope of the study was limited to balcony walls, including window-wall junctions, and was conducted by comparing cases with and without thermal break insulation structures for a clear conclusion. The study was conducted using the equivalent U-value in each case. The equivalent U-value was calculated by deriving through 2 dimensional steady-state heat transfer analysis of each case balcony envelope. And building energy was calculated using the derived equivalent U-value. According to the calculation results, for unexpanded balconies, the equivalent U-value was reduced by about 80%, and the heating and cooling load was reduced by about 20%. In the case of extended balconies, the equivalent U-value was reduced by about 57% and the resulting heating and cooling load was reduced by about 12%.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.04a
• /
• pp.66-71
• /
• 2009

To reduce the building energy consumption, the major advanced nations are conducting actively many researches on so called a "self-sufficient building(or other words zero energy building)" which can support its required energy by itself. Given this background, KIER(Korea Institute of Energy Research) built full size test-bed of the zero energy solar house in early 2002, and has studied on the self-sufficient heating load up to now. We analyse the sensitivity between the heating load and the solar radiation gain according to the change the effective transmittance of windows. The authors classified 9 cases by solar transmittance of glass. The results demonstrate the solar radiation amount is 0.466 MWh from the eastern zone of Fl.,1(the first floor), 0.332 MWh from Fl.,2(the second floor), 1.194 MWh form the southern zone of F1., and 0.822 MWh from the southern zone of Fl.,2 on the case 1(each cases are classified by window types). On the case 9, the solar radiation amount is 3.127 MWh, 2.662 MWh, 8.799 MWh and 6.078 MWh from the same condition. For the Fl.,1, the amount of Heat Load that is saved per year ranged 10.5 to 48 %, and the reduction was anywhere from 0.2 to 17.9% for Fl.,2

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.12
• /
• pp.1204-1209
• /
• 2005

In-situ measurement was made to evaluate chiller performance and thermal storage density of an ice thermal storage system. The system belonged to a big hotel and the measurement was conducted during late October. Owing to very small cooling load, the data logging was possible for a single thermal storage cycle. However, operation history of the chiller showed a relatively good spectrum of data for performance evaluation. COP and thermal storage density were calculated. The COP at full load was about 4.07, which was lower than $4.8\~6.4$ of new chillers. The measured storage density was about $10.9RT-h/m^3\;(=152MJ/m^3)$, which also was lower than a criterion of normal performance $(above\;13.0RT-h/m^3\;or\;181MJ/m^3)$. The study result provides technical basis for quantitative ESCO business scenario.

• Structural Engineering and Mechanics
• /
• v.71 no.2
• /
• pp.109-118
• /
• 2019

This paper presents the numerical simulation of membrane structure under impact load. Firstly, the numerical simulation model is validated by comparing with the test in Hao's research. Then, the effects of the shape of the projectile, the membrane prestress and the initial impact speed, are investigated for studying the dynamic response and failure mechanism, based on the membrane displacement, projectile acceleration and kinetic energy. Finally, the results show that the initial speed and the punch shape are related with the loss of kinetic energy of projectiles. Meanwhile, the membrane prestress is an important factor that affects the energy dissipation capacity and the impact resistance of membrane structures.

• Journal of the Korean Solar Energy Society
• /
• v.34 no.3
• /
• pp.1-11
• /
• 2014

The Korean government plans to introduce the building energy performance standard which regulates the annual energy consumption of buildings. This paper aimed to set up the reference building from database based on the building design trends for non-residential buildings. We surveyed the design data of 435 non-residential buildings which were granted building permission from 2007 to 2011. And we conducted estimation on the heating & cooling load and the energy consumption of the reference building using ECO2 program. From results, the reference building of non-residential buildings was office building which had a total 7 floors and $20,838m^2$ gross floor area. And it suggests the design reference data of building envelope, HAVC, heat source equipment and lighting system for the reference building. The total annual energy use of the reference building was $151.9kWh/m^2yr$.

• Earthquakes and Structures
• /
• v.26 no.6
• /
• pp.449-461
• /
• 2024

The vertical reinforcement connection between the precast reinforced concrete shear wall and the cast-in-place reinforced concrete member is vital to the performance of shear walls under seismic loading. This paper investigated the structural behavior of three precast reinforced concrete shear walls, with different levels of connection (i.e., full connection, partial connection, and no connection), subjected to quasi-static lateral loading. The specimens were subjected to a constant vertical load, resulting in an axial load ratio of 0.4. The crack pattern, failure modes, load-displacement relationships, ductility, and energy dissipation characteristics are presented and discussed. The resultant seismic performances of the three tested specimens were compared in terms of skeleton curve, load-bearing capacity, stiffness, ductility, energy dissipation capacity, and viscous damping. The seismic performance of the partially connected shear wall was found to be comparable to that of the fully connected shear wall, exhibiting 1.7% and 3.5% higher yield and peak load capacities, 9.2% higher deformability, and similar variation in stiffness, energy dissipation capacity and viscous damping at increasing load levels. In comparison, the seismic performance of the non-connected shear wall was inferior, exhibiting 12.8% and 16.4% lower loads at the yield and peak load stages, 3.6% lower deformability, and significantly lower energy dissipation capacity at lower displacement and lower viscous damping.

• Journal of Convergence for Information Technology
• /
• v.9 no.1
• /
• pp.54-60
• /
• 2019

The recent climate change is exacerbating the external thermal environment and increasing the amount of energy used in building. Energy Plus was used to evaluate low energy technology performance of buildings responding to climate change. The test types of basic building(control) and evaporative mist system + basic building(EMS), and the analysis results of each type are compared. Energy performance evaluation result, Cooling peak load were EMS reduction compared to control is about 9%. Annual cooling load per unit area were EMS reduction compared to control is about 17%. Annual energy use per unit area were EMS reduction compared to control is about 10%. Therefore, the effect of the evaporative cooling system is considered to be good through energy reduction technology of building, according to the amount and distance of the evaporative mist system in the future research on building energy performance evaluation should be carried out.

• Journal of the Korean Solar Energy Society
• /
• v.35 no.5
• /
• pp.39-48
• /
• 2015

In this study, the solar chimney, one of the passive solar systems, is proposed as a method to improve the thermal environment of northern zones in buildings. As this well-known system has rarely been used in building projects, an adequate application of the system is proposed in this paper: the solar chimney system is designed to meet the required ventilation rate and consequently to reduce the ventilation load in the northern part of a building. To investigate such a possibility, a numerical model for the system is developed, and results of numerical tests are used for energy simulations. The results were taken into account for test simulations in EnergyPlus. As a result, approximately 75% of the volumetric ventilation rate required in the north zone could be supplied with the air volume acquired through the system and the monthly mean load was reduced by 29.5%, from 1.584 kWh to 1.117 kWh. The analyses of hourly mean heating and ventilation load over the heating period indicated that the system was very effective at around 13:00. Results show that 33% reduction in the ventilation load and 17% in the heating load for the north zone could be acquired through this system.

• Proceedings of the SAREK Conference
• /
• 2007.06a
• /
• pp.142-142
• /
• 2007