• 한국태양에너지학회 논문집
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• 제34권3호
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• pp.89-97
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• 2014

Recently design standard for energy-saving in apartment buildings has been consolidated gradually on the basis of evaluation and certification standards of energy efficiency of buildings, the energy-saving policy of building at home and abroad. Performance criteria for thennal insulation as well as fenestration has been progressively enhanced, and performance criteria for ventilation and airtightness of the building have also been re-developed. Therefore, heating and cooling load characteristics of the apartment building can be changed. For the design of the upcoming heating and cooling equipment in apartment buildings, it is necessary to evaluate the heating and cooling load characteristics according to the design strategies for energy saving in apartment buildings. As a result, in this study, it is intended to use as a resource for analyzing the impact that the adoption of energy-saving design variables for each of the apartment buildings, to predict the heating and cooling load characteristics in the apartment building.

• 설비공학논문집
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• 제14권12호
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• pp.1092-1101
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• 2002

The objective of this study is to develop energy saving strategies for indoor swimming pools and to estimate the effect of each energy saving strategy. For this purpose, field measurements regarding pool water heating energy, domestic hot water heating energy are conducted and a base energy consumption model is implemented using the DOE-2.1E program. The results of the study reveal that 25% of the total pool water heating energy may be saved by using night time pool covers, 27% of the total domestic hot water heating energy may be saved by using a waste water heat recovery system (effic. 60%), and of the total ventilation energy may be saved using an exhaust air heat recovery system (effic. 60%).

• 한국태양에너지학회 논문집
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• 제39권5호
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• pp.11-28
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• 2019

Governments are increasing energy efficiency in buildings through various policies to reduce building energy consumption. In 2002, the European Union adopted a building energy performance guideline to set minimum efficiency standards for residential and commercial buildings. Starting in 2020, all EU member states should ensure that all buildings are Near-Zero Energy Buildings (NZEB). In Korea, the government issued a zero-energy certification system. Since 2020, public buildings are required to cover energy consumption with the energy produced in buildings. As the demand for building energy simulation has increased to increase the energy efficiency of these buildings, the International Standard Organization (ISO) has created a standard for calculating building energy requirements called ISO 13790. This standard was revised to ISO 52016 in 2017. In this research, ISO 13790, which calculates the energy needs of existing buildings, and ISO 52016, which replaces them, are compared and analyzed, and applied to the calculation of heating energy needs of buildings. For models without thermal zoning(Case A), the difference in annual heating energy needs calculated from each criterion is $1.08kWh/m^2$, which is about 2% higher in ISO 52016. In the case of the thermal zoning model(Case B), the difference in annual heating energy needs calculated by each standard was $0.97kWh/m^2$, which was about 2% higher than ISO 52016. The heating energy needs model without thermal zoning has a higher energy needs than the heating energy needs model with thermal zoning. It is about 16% energy at $8.58kWh/m^2$ for ISO 13790 and $8.69kWh/m^2$ for ISO 52016.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.136.1-136.1
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• 2011

This paper proposes the method to implement the railroad switching point heating system using the hybrid of the photovoltaic and wind power. The goal of the implementation of the railroad switching point heating system is to prevent freezing of the snow in the winter. The heating system of railway used to supply electricity through photovoltaic and wind power to prevent freezing. Hot wires of the railroad switching point heating system are used about 2kW of electric energy at the day. The electric energy of 2kW used the length of the hot wires about 3m. As the ON and/or OFF mode considering the tracks temperature and the ambient temperature, so the way the use of power-saving effect. In addition, the system can be used the railroad switching point heating system in winter and railway signal and street lights around the track in summer. In experiment, we acquired the power data according to time at the day of photovoltaic and wind power. We confirmed the temperature rise using the heating cable for 3m of $85^{\circ}C$, 30W/m. The temperature rise of the heating cable changes the temperature of $5^{\circ}C$ after 10 minutes and $11^{\circ}C$ after 10 minutes. We have confirmed the possibility of the railroad switching point heating system using the hybrid of the photovoltaic and wind power.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.317-317
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• 2011

Enhanced ICRF (Ion Cyclotron Range of Frequency) ion heating of H-mode D(H) plasma will be tried in 2011 KSTAR experimental campaign. Minority heating is a main ion heating scheme in the ICRF. Its efficiency increases as the hydrogen minority ratio increases in deuterium plasmas. And it should be sustained at a lower level than the critical minority ratio. Consequently, it is important to elevate the critical ratio to maximize ion heating and it is possible by increasing the ion temperature or parallel wave number (k${\parallel}$) of the antenna. Increasing the k${\parallel}$ is not a good approach since the coupling efficiency decreases exponentially with regard to k${\parallel}$ as well. So the remaining method is to increase ion temperature by using NB (Neutral Beam). Ion heating fraction of NB increases as the electron temperature increases. Therefore, we will try to heat electron by using ECH together with NB ion heating before ICRF power injection. The ICRF heating efficiency will be compared with respect to several NB+ECH+ICRF heating combinations through several diagnostics such as XICS (Xray Imaging Crystal Spectroscopy), CES (Charge Exchange Spectroscopy) and neutron measurement. The theoretical background and the experimental results will be presented in more detail in the conference.

• 태양에너지
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• 제2권1호
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• pp.49-58
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• 1982

Aim of this study was to obtain the heating performance and the economic evaluation on solar heating system for greenhouse which area of floor was $90m^2$. For heating performance effective solar energy for the greenhouse was compared with overall heating loads including coefficient of heat transfer and conduction. And the economic evaluation solar heating system was evaluated by comparison its initial investiment costing with oil saving cost. Initial investiment costing included collector cost, storage cost, piping cost, control system cost and miscellaneous costs which included pumps, motors etc. The contents of this study included the survey of climate conditions for solar heating, long-term collector performance and optimum collector area of solar heating system in existing greenhouse. The results are follows: 1. Average horizontal radiation during winter was $2,434Kcal/m^2$ day which was the highest value in this country, so the climate conditions of Suwon was suitable for solar heating. 2. Resulting calculation of the optimum collector area was $30m^2$ and the solar energy accounted for 30% of the overall heating load. 3. The capacity of storage tank required 60 liter per unit area ($m^2$) of solar collector.

• KIEAE Journal
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• 제7권5호
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• pp.81-86
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• 2007

The research analyzes the arrangement of boiler and hot water header, the method of radiator pipe setting, hot water supply control, hourly heating situation of each room for underfloor radiant heating systems in Korea and suggests an alternative to improve to efficient heating method. One of the best options for install position of hot water distributor is under kitchen sink which is center point of all rooms, according to previous research of the energy saving strategies. When the radiator pipes are arranged to each individual room instead of bedrooms through livingroom and kitchen, it has energy saving effects. For rooms without occupancy according to a time period, hot water supply method should be intermittent heating rather than continuous heating. For this intermittent heating method, individual control of hot water supply is more practical, and it can lead to massive energy savings. The intermittent heating system has time-lag, so it is more effective in energy saving with mild and comfort condition if the spaces are preheated by automatic control equipment prior to required time.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.381-386
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• 2008

In this study, the energy characteristic of automatic thermostatic valves according to each heating method in floor radiant heating system were researched by computer simulation. For the analysis of unsteady heat transfer phenomena in household, the method of using electrical equivalent R-C circuit is applied, and radiation heat transfer between panel, ceiling and walls in household is calculated by enclosure analysis method. The parametric study on heating method, valve's control method, outdoor air condition, supply heating water temperature, supply flow rate are performed to compare energy characteristic, respectively.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.109-114
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• 2009

The dominant heating system used in Korean residential apartment buildings is a hydronic radiant floor heating system, known as the Ondol system. The most common control strategy applied to this traditional hydronic radiant system is a simple on-off control that intermittently supplies "hot water of a fixed temperature" at a "constant flow rate" to each room. However, the current problems with the aforementioned control are as follows: (1) since the simple on-off control is usually based on a one point measured temperature (a signal from a thermostat installed in a living room) in each dwelling unit, heating energy use for unoccupied rooms as well as a difference in temperatures between spaces (master bedroom, living room, bedroom1, bedroom2) can occur occasionally. (2) the most widely used residential water splitter has static valves, and is thus not able to change the flow rate to each room depending on the space heating load. In other words, the ratio of flow rates to rooms is fixed after construction, resulting in over- or under-heating and an improper use of energy. The aim of this paper is therefore to investigate the differences in the system's performance between control strategies in terms of the flow rate control and sensor location. It is shown that energy savings of control strategies are strongly influenced by occupant schedule.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.825-832
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• 2008

A simulation program is developed for analysing thermal networking process between the District heating and the CES(Community Energy Supply) systems. The effects of thermal networking on the District heating facilities previously being operated are implemented using mathematical correlations in terms of the fuel consumption and energy load such as heating and electricity. The operational characteristics according to the prime movers is modeled based on the materials of efficiency as a function of operational load. The unit energy load model is also developed extensively for several building types such as apartment complex, hotel, hospital, buildings for business and commercial use respectively. The specific features of the newly developed program in simulation of thermal networking process in district heating is described in terms of the reliability and the easiness for operating it etc.