• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.224-235
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• 2019

The increase in the amount of energy used in the agricultural sector due to the expansion of agricultural machinery and greenhouse horticulture has caused a range of problems, such as an increase in the cost of input, such as heating costs and greenhouse gas emission. To overcome these problems, this study examined the current status of energy use in greenhouse horticulture as well as the change patterns of non-taxable oil and agricultural electricity, and reviewed the current status of the supply of renewable energy and energy saving facilities for agriculture. This study investigated the area of advanced and renewable energy and energy saving facilities implemented, applied the energy saving ratio of advanced and renewable energy and energy saving facilities, and determined the effects of renewable energy in the agricultural sector, such as increase in production, decrease in heating cost, reduction in Government financial expenditure, reduction in greenhouse gas emission, and oil substitution effect.

• Journal of Soil and Groundwater Environment
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• v.25 no.1
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• pp.84-94
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• 2020

Jeju Island is seeking reliable ways to secure alternative water resources using rainwater in order to conserve and manage its groundwater as sustainable water resources. The purpose of this study is to investigate the rainwater storage capability of small-size storage facilities installed at farmhouses in Uigwi and Wimi of Namwon-eup region. The rainwater outflows from the storage facilities in rain events were analyzed. The appropriate size of rainwater utilizing facilities are suggested to be about 5,800 ㎥ in Uigwi area and 4,900 ㎥ in Wimi area based on the calculation from the rainfall frequency and runoff amounts. If those facilities are put into operation in Uigwi and Wimi area, it is estimated approximately 32.3 and 11.5% of total agricultural water can be supplied by the facilities. Wimi area showed low rainwater usage because of less number of facilities relative to the size of farm areas and less intensive underground water usage. It is analyzed that more than 55% of agricultural water can be supplied by rainwater if 70 facilities without the rainwater facilities are connected to the rainwater utilizing facilities.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.83-95
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• 2020

The economic issue of the period of return versus investment has emerged to efficiently utilize the thermal energy of public resource recovery facilities using waste and private thermal source facilities using BIO-SRF. Accordingly, the optimum temperature and pressure facilities are required beyond the traditional designed, constructed and operated. In this study, we analyzed current energy output by different heat and pressure model in domestic facilities, and calculated the characteristics of green-house gas emission. In order to, utilize the thermal energy producing facilities using waste and biomass fuel more efficiently, it is temperature and pressure, which will lead to more lucrative investment and return as well.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.354-359
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• 2012

With the long-term use of fossil fuel, the whole world is suffering from serious abnormal changes in weather caused by global warming. For this reason, many countries are reducing greenhouse gas emissions out of obligation and the allowable emissions are assigned to each country. Korea is also putting much effort into reducing greenhouse gas emissions by 30 percent against BAU(Business As Usual) by 2020, and is pushing ahead with several projects such as 'Million Green Home' and 'Hatsal Gaduk Home' to expand the use of new renewable energy in house as part of its policy. This study was designed to come up with improvements and help to expand photovoltaic facilities, by investigating and analyzing the current state of photovoltaic facilities in the country and problems in installing them through an in-site reconnaissance and a survey in Jecheon area. As the result, it was found that residents in the area were inadequate to operate and install photovoltaic facilities, lacked awareness of them and felt burdened economically by managing and installing them, although they had a high awareness of solar energy and photovoltaic facilities are constantly increasing with governmental support. In conclusion, it is considered that as improvements, operational effects should be increased through development of techniques, factors to reduce the effects in operating them due to insufficient management and installation should be removed and awareness of residents need to be improved through long-term plans, political support and education of the government.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.391-400
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• 2014

The number of large scale greenhouses has recently been increasing to cope with mass consumption of agricultural product. Korean government announced a new development plan for constructing greenhouse complex in reclaimed lands for the purpose of improvement in exports and activation of domestic market of agricultural product. Wind environment in the reclaimed land is totally different from that of inland area, and it can give a strong influence on ventilation performance of naturally ventilated greenhouse facilities. In this study, internal airflow analysis of naturally ventilated greenhouse built on a reclaimed land was conducted using wind tunnel and PIV for validation research. Later, the PIV measured results will be used to improve the accuracy of 3 dimensional CFD simulation in the future. Wind profile at a reclaimed land was produced using ESDU program and it was applied to the wind tunnel. The calculated error was only 5% and 0.96 of correlation coefficient, implying that the computed profiles were designed properly. From the measured results, when external wind speed changed from $1m{\cdot}s^{-1}$ to $1.5m{\cdot}s^{-1}$, air velocities inside the greenhouse which PIV measured were also increased proportionately in case of both side vent open and side-roof vent open. Considering reduced ratio of air velocity inside the greenhouse, it was measured a minimum of 40% in case of side vent and 30% in case of side-roof vent compared with external wind speed from each vent type. From the quantitative and qualitative PIV analysis, the PIV measured results indicated that there were well ventilated and stagnant areas in the greenhouse according to external wind condition as well as ventilation design.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.113-124
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• 2012

Reliable estimation of energy load inside the greenhouse and the selection of cooling and heating facilities are very important preceding factors to save energy as well as initial and maintenance costs of operating a greenhouse. Recently, building energy simulation (BES) technique to simulate a model similar to the actual conditions through a variety of dynamic simulation methods, and predict and analyze the flow of energy is being actively introduced and developed. As a fundamental research to apply the BES technique which is mainly used for analysis of general buildings, to greenhouse, this research designed four types of naturally-ventilated greenhouses using one of commercial programs, TRNSYS, and then compared and analyzed their energy load properties, by applying meteorological data collected from six regions in Korea. When comparing the greenhouse load of each region depending on latitude and topographical characteristics through simulation, Chuncheon had nearly 9~49 % higher heating load per year than other regions, but its annual cooling load was the reverse to it. Except for Jeju, 1-2W type greenhouses in five regions showed about 17 % higher heating load than a widespan type greenhouse, and 1-2W type greenhouses in Chuncheon, Suwon, Cheongju, Daegu, Cheonju and Jeju had 23 %, 20 %, 17 %, 16 %, 18 % and 20 % higher cooling load respectively than a wide span-type one. Glasshouse and vinyl greenhouse showed 8~11 % and 10~12 % differences respectively in heating load, while 2~10 % and 7~10 % differences in cooling load respectively.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.90-95
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• 2008

It has become a big matter of concerns that the skill and measures against reduction of energy and cost for heating a protected horticultural greenhouse were prepared. But in these days necessity of cooling a protected horticultural greenhouse is on the rise from partial high value added farm products. In this study, therefore, a horizontal type geothermal heat pump system with 10 RT scale to heat and cool a protected horticultural greenhouse and be considered to be cheaper than a vertical type geothermal heat pump system was installed in greenhouse with area of $240\;m^2$. And cooling performances of this system were analysed. As condenser outlet temperature of heat transfer medium fluid rose from $40^{\circ}C$ to $58^{\circ}C$, power consumption of the heat pump was an upturn from 11.5 kW to 15 kW and high pressure rose from 1,617 kPa to 2,450 kPa. Cooling COP had the trend that the higher the ground temperature at 1.75 m went, the lower the COP went. The COP was 2.7 at ground temperature at 1.75 m depth of $25.5^{\circ}C$ and 2.0 at the temperature of $33.5^{\circ}C$ and the heat extraction rate from the greenhouse were 28.8 kW, 26.5 kW respectively at the same ground temperature range. 8 hours after the heat pump was operated, the temperature of ground at 60 cm and 150 cm depth buried a geothermal heat exchanger rose $14.3^{\circ}C$, $15.3^{\circ}C$ respectively, but the temperature of ground at the same depth not buried rose $2.4^{\circ}C$, $4.3^{\circ}C$ respectively. The temperature of heat transfer medium fluid fell $7.5^{\circ}C$ after the fluid passed through geothermal heat exchanger and the fluid rejected average 46 kW to the 1.5 m depth ground. It analyzed the geothermal heat exchanger rejected average 36.8 W/m of the geothermal heat exchanger. Fan coil units in the greenhouse extracted average 28.2 kW from the greenhouse air and the temperature of heat transfer medium fluid rose $4.2^{\circ}C$after the fluid passing through fan coil units. It was analyzed the accumulation energy of thermal storage thank was 321 MJ in 3 hours and the rejection energy of the tank was 313 MJ in 4 hours.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.29-37
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• 2012

An experiment for an optimized automatic greenhouse environment in a flower farming greenhouse by building a ubiquitous sensor network with various sensors was conducted and the results were evaluated. And various culturing environmental information and data in the greenhouse were collected and analyzed. Then, the greenhouse was designed to maintain the best culturing environment on the basis of existing recommended optimized figures. By measuring the growth of the crops in the greenhouse, A system which controls facilities in the greenhouse to maintain the best culturing environment in accordance with change in the environment was analyzed.Computer simulation result proced that we discovered that controlling the facilities and the artificial light source increased production, enhanced quality, reduced labor and heating cost immensely. The experiment has proved that the u-flower farming system can maximize the income of farm families by sending warning messages to users of this system when weather suddenly changes so that users may cope with such changes and maintain the best culturing environment.

• Journal of Animal Environmental Science
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• v.17 no.sup
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• pp.21-34
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• 2011

In this study, researches on the development of country specific greenhouse gas measurement and sampling methods from the livestock sector were reviewed. Research on greenhouse gas emission factors was started in early 2000 but was not actively involved in the development of livestock sector based emission factor: since 2009, works are underway for the development of livestock sector based emission factor. Most of the research on greenhouse gas emission in the field of animal studies were done by National Institute of Animal Science, because of the uniqueness of the research laboratories. Methods of emission measurement are still not internationally certified and therefore, measurement and sampling methods for Korea livestock sector are being studied, consulting the worldwide research trends. Flux chamber method are commonly using in Korea for green house gas emission factors measurement. In recent years, continuous measurement of the microclimate was introduced to measure greenhouse gases from livestock manure storage facilities and the micrometeorology method should be adapted as recommended by Intergovernmental Penal on Climate Change (IPCC) Guideline.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.37-42
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• 2015

In order to provide fundamental data for the creation of environmental design criteria for horticultural facilities, we developed a method to easily calculate the seasonal heating load applying heating degree-hour while taking into account heating load reductions due to solar radiation in the daytime, and reviewed through greenhouse heating experiments. Heating experiments and measuring meteorological environments were carried out in three greenhouses located at Buyeo, Cheonan, and Buan, and we derived reduction factors of seasonal heating load according to hours of sunshine. Daily mean hours of sunshine during the experiment period in each of the greenhouse was 4.0 to 8.3 hours, and the reduction factor of seasonal heating load was 0.64 to 0.85, has been shown to decrease linearly with the increase in hours of sunshine. A method to estimate the seasonal heating load for greenhouses was developed using the reduction factor of seasonal heating load derived from the greenhouse heating experiment, including the adjustment factor of seasonal heating load according to hours of sunshine. The developed method was validated through heating experiments in a greenhouse located at Cheonan. Greenhouse seasonal heating loads calculated by the method developed in this study were analyzed to show the estimate error of 1.2 to 5.0%. It showed that the accuracy increased 2.3 times more than when using the heating load reduction factor of 0.75 applied uniformly in previous studies. Thus, the calculation method of seasonal heating load for greenhouses considering hours of sunshine developed in this study could be utilized for energy estimation, management planning, and economic evaluation in greenhouse design.