• Nuclear Engineering and Technology
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• 제52권12호
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• pp.2812-2820
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• 2020

House load operation (HLO) occurs when the generator supplies power to the house load without triggering reactor trips during grid disturbances. In Korea, the HLO capability of optimized power reactor 1000 (OPR1000) plants has prevented several reactor trips. Operational experiences demonstrate the difference in the reactor trip incidence due to grid disturbances between OPR1000 plants and Westinghouse plants in Korea, attributable to the availability of the HLO capability. However, probabilistic safety assessments (PSAs) for OPR1000 plants have not considered their specific design features in the initiating event analyses. In an at-power PSA, the HLO capability can affect the initiating event frequencies of general transients (GTRN) and loss of offsite power (LOOP), resulting from transients within the grid system. The initiating event frequencies of GTRN and LOOP for an OPR1000 plant are reduced by 17.7% and 78.7%, respectively, compared to the Korean industry-average initiating event frequencies, and its core damage frequency from internal events is reduced by 15.2%. The explicit consideration of the HLO capability in initiating event analyses makes significant changes in the risk contributions of the initiating events. Consequently, for more realistic at-power PSAs in Korea, we recommend incorporating plant-specific HLO-related design features when estimating initiating event frequencies.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.197.2-197.2
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• 2010

The study on the operation characteristics of solar space and water heating system with ground source heat pump (GSHP) as a back-up device was carried out. This system, called solar thermal and geothermal hybrid system (ST/G), was installed at Zero Energy Solar House II (KIER ZeSH-II) in Korea Institute of Energy Research. This ST/G hybrid system was developed to supply all thermal load in a house by renewable energy. The purpose of this study is to find out that this system is optimized and operated normally for the heating load of ZeSH-II. Experiment was continued for seven months, from October to April. The analysis was conducted as followings ; - the contribution of solar thermal system. - the appropriateness of GSHP as a back-up device. - the performance of solar thermal and ground source heat pump system respectively. - the adaptation of thermal peak load - the operation characteristics of hybrid system under different weather conditions. Finally the complementary measures for the system simplification was referred for the commercialization of this hybrid system.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(2)
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• pp.588-595
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• 1995

The Load Rejection to House Load test at 100% power was successfully performed during the YGN 4 PAT period. In this test, all plant control systems automatically controlled the plant from 100% power to house load operation mode. The LTC code, which was used in the performance analysis during the design process of YGN 3&4, predictions of the test agreed with the measured data demonstrating the validity of the code as well as the completeness of the plant design.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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• pp.398-403
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• 1998

The Load Rejection to House Load test at 50% power was successfully peformed during the UCN 3 PAT period. In this test, all plant control systems automatically controlled the plant from 50% power to house load operation mode. The KISPAC code, which was used in the performance analysis during the design process of UCN 3&4, predictions of the test agreed with the measured data demonstrating the validity of the code as well as the completeness of the plant design.

• 한국기계가공학회지
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• 제21권3호
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• pp.110-117
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• 2022

A chiller cooler absorbs the thermal energy of water to generate cold water and supplies the generated cold water to a cold water pipe buried in the wall of a small mobile modular house to greatly increase the cooling area. An attempt was made to reduce the required cooling time significantly. A small chiller cooler suitable for the cooling load of a small mobile modular house with an area less than 3.3 m² was employed. When cooling is done during summer using a chiller cooler installed outdoors, heat absorption energy loss occurs in the cold water pipe owing to the high temperature. To address this, a study was conducted to reduce the endothermic energy loss significantly. As the mass flow rate of the cold water flowing inside the cold water pipe increased, the temperature decrease gradient of the cold water increased. From the start of the cooling operation, the air temperature of the small mobile modular house decreased linearly in proportion to the operation time. Furthermore, the temperature of the air inside the small mobile modular house decreased in proportion to the increase in the flow of water inside the cold water pipe.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.746-748
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• 1996

House load operation (HLO) is the Willy of a plant to continue to operate while completely separated from the transmission system. HLO capability is recently adopted as basic design requirement for nuclear power plants, since HLO capability increases the plant availability and power system reliability. However, HLO results in the voltage and frequency transients to motors and pumps. This paper presents the computer simulation results such as the transient speeds, voltages, and control system responses of turbine/g enerator during HLO. This paper also suggests the plant design features required for HLO capability and the transient speed/vlitage limits caused by HLO.

• 설비공학논문집
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• 제29권12호
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• pp.638-644
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• 2017

Optimal cooling operation algorithm was developed based on a simulation case of a single family house model equipped with renewable energy facility. EnergyPlus simulation results were used as virtual test data. The model contained three energy storage elements: thermal heat capacity of the living room, chilled water storage tank, and battery. Their charging and discharging schedules were optimized so that daily electricity bill became minimal. As an optimization tool, linear programming was considered because it was possible to obtain results in real time. For its adoption, EnergyPlus-based house model had to be linearly approximated. Results of this study revealed that dynamic cooling load of the living room could be approximated by a linear RC model. Scheduling based on the linear programming was then compared to that by a nonlinear optimization algorithm which was made using GenOpt developed by a national lab in USA. They showed quite similar performances. Therefore, linear programming can be a practical solution to optimal operation scheduling if linear dynamic models are tuned to simulate their real equivalents with reasonable accuracy.

• Architectural research
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• 제15권3호
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• pp.143-150
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• 2013

The Korean government recently has rediscovered the potential value of Han-Ok, the Korean traditional house, as an eco-friendly building. In order to objectively verify the environmental performance of Han-Ok as a low carbon green building, this paper suggests the analysis method of GHG emission load of Korean traditional house, based on Life Cycle Assessment, which is commonly abbreviated to "LCA". The environmental impacts caused by building construction and operation can be analyzed through the sum of input and output data from every phase. The study particularly describes the GHG reduction effect by using traditional building materials such as wood products, traditional clay roof tiles, and mud, which are mainly used to construct Han-Ok. Also the study proposes the method for comparative analysis of quantity of GHG emissions in building's entire life cycle so that the data can be used as a reliable basis to optimize the environmental performance of building.

• 산업경영시스템학회지
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• 제32권1호
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• pp.44-51
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• 2009

A bonded warehouse is the warehouse located in bonded area. It functions not only as a general warehouse but also as a place for managing the work related to import and export bonded goods. As a general warehouse, it uses the rack system to store the goods and the folk lift truck to move the unitized goods. The operation of the storing system closely related to the efficiency of space uses in a warehouse and vehicle working. Thus, vehicle performance measured in distance units in the ware-house could be used as one of the key performance measure in warehouse system. This paper focuses on the operation efficiency of the bonded warehouse which uses rack system for the storing and the folk lift truck for moving goods. The method of load allocation for balancing the rack uses and vehicle operation for maximizing efficiency are the specific concerns in this paper. The simulation study is conducted to find a policy for efficient vehicle operation based on balanced rack utilization, and the favorable result for the system operation would lead the usable proposal in vehicle operation.

• Nuclear Engineering and Technology
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• 제33권3호
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• pp.339-348
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• 2001

NSSS Control Systems automatically mitigate transient conditions and leads to a stable plant condition without operator actions when a transient occurs during normal power operation. In this paper, the function and performance of NSSS control systems were examined and evaluated by comparing the predicted results with the measured data for the selected events. Loss of a Main Feedwater Pump and Load Rejection to House Load Operation events were selected for the evaluation among the transient tests peformed during the Power Ascension Test (PAT) of UCN unit 4. The overall schematic control actions of NSSS control systems can be evaluated easily through the observation of these two typical events. The selected events were analyzed by the KISPAC computer code[l] which had been used in developing the control logic and determining the control setpoints during the plant design. Additionally, the performance of FWCS during low power operation was evaluated. The result of evaluation showed that the NSSS control systems were designed properly and the performance of the NSSS control systems was excellent and also the computer code had a good prediction capability.