• 한국태양에너지학회 논문집
• /
• 제38권5호
• /
• pp.37-47
• /
• 2018

The heating performance of a solar thermal seasonal storage system applied to a glass greenhouse was analyzed numerically. For this study, the gardening 16th zucchini greenhouse of Jeollanam-do agricultural research & extension services was selected. And, the heating load of the glass greenhouse selected was 576 GJ. BTES (Borehole Thermal Energy Storage) was considered as a seasonal storage, which is relatively economical. The TRNSYS was used to predict and analyze the dynamic performance of the solar thermal system. Numerical simulation was performed by modeling the solar thermal seasonal storage system consisting of flat plate solar collector, BTES system, short-term storage tank, boiler, heat exchanger, pump, controller. As a result of the analysis, the energy of 928 GJ from the flat plate solar collector was stored into BTES system and 393 GJ of energy from BTES system was extracted during heating period, so that it was confirmed that the thermal efficiency of BTES system was 42% in 5th year. Also since the heat supplied from the auxiliary boiler was 87 GJ in 5th year, the total annual heating demand was confirmed to be mostly satisfied by the proposed system.

• 지질공학
• /
• 제25권4호
• /
• pp.599-612
• /
• 2015

신재생에너지는 지금까지 화석연료의 잔량과 환경적인 면에서 그 중요성이 부각되었지만, 경제성에 대한 요구도 점차 커져가고 있다. 특히, 지열 냉난방시스템은 초기 투자비가 큰 점이 단점으로 부각되어 경제성 분석을 통한 결과 제시가 더욱 중요해지고 있다. 따라서 본 연구에서는 지열 냉난방시스템의 경제성과 이산화탄소 발생량을 경유보일러, 도시가스 보일러, 수직밀폐형 및 SCW형의 4가지 방식으로 비교하여 분석을 수행하였다. 생애주기비용분석 결과, 지열 냉난방시스템의 경제성이 높게 나타났으며, 이중 SCW형 지열 냉난방시스템을 이용하는 경우 절감액이 가장 높은 것으로 분석되었다. 또한 이산화탄소 발생량 분석 결과, SCW형 지열 냉난방시스템을 적용할 때 저감량이 가장 크게 나타났다. 따라서 본 연구결과에서 제시된 분석 결과를 대규모 시설농업단지나 간척지에 적용 시 많은 비용을 절감할 수 있을 것으로 판단된다.

• 동력기계공학회지
• /
• 제21권3호
• /
• pp.30-36
• /
• 2017

Carbon fiber shows excellent heat generation value and thermal efficiency comparing with the metallic materials because of its far infrared-rays and radiant heat. So, high performance and economic steam boiler system for the industry can be manufactured by using the carbon fiber heater. The far infrared ray radiation rate was more than 90 % of carbon fiber. Steam boiler system with carbon fiber heater in this study is made up of heating section. In the proof test of steam boiler, the aimed temperature and dwelling time were at $500^{\circ}C$ for 8,000 hours, $600^{\circ}C$-3,000 hours, and $700^{\circ}C$-1,000 hours. The temperature rise rate of steam boiler with carbon fiber heater was about 40% faster than that of the conventional boiler.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
• /
• pp.250-253
• /
• 1989

As the necessity of increasing the midnight base load is extensively increased, electric power companies have to increase the demand of midnight electrical power by lowering the electrical charge rate at midnight. One of the most widely used midnight equipments is the heat Storage type's electrical boiler. A Single chip microprocessor controller for the heat-storage type's electrical boiler is developed. This controller call reduce the undesirable peak load at the begining of midnight (i.e.11 P.M.) time band by using backward load control method. Futhermore, this controller enables reservation of heat storge and the effective heating control the field test has been done by use the boiler for 66$m^2$ with the heater of 21KW quality.

• Journal of Mechanical Science and Technology
• /
• 제15권2호
• /
• pp.239-247
• /
• 2001

Measured radiative heat fluxes on the furnace exit plane of a heavy duty power boiler of steam output 1650 T/h are discussed. A high-ash pulverized bituminous coal was used. Such measurements are necessary to improve heat fluxes inside a steam boiler furnace was manufactured. An extra small heat radiation sensor was placed in the water cooled head of the probe. The sensor had no direct contact with furnace gases and measured only the radiant energy. There was no exposure to convective heat transfer. With the radiometric probe, one can obtain a spherical indicatrix of radiation intensity as well as hemispherical radiative heat flux incident on any surface passing through a measuring point inside the furnace. Thus, the quantity of radiation energy, passing through the furnace exit plane, to the convective heating surfaces and the quantity of radiation energy going in the opposite direction were measured. A formula for relative radiative heat flux on the furnace exit plane has been proposed.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 춘계학술대회 논문집
• /
• pp.450-454
• /
• 1997

This system is the automatic boiler tube bending equipment which has four heads for bending the tube and the carriage for moving the tube. The system consists of two frames for transporting each moving parts, high-frequency heating equipment for heating the tube in hot bending, control panel for inputting the job data operating, remote control unit for concetration and distribution of input/output, and the monitoring system which can establish unmanned operationby receiving the bending job data via LAN form a design teamwhich produces the job data and schedule based on master production plan and diagnoses bending data change, input, whole system status, and system malfunctions. By employing this system, 30% of production improvement was achieved was achieved comparing to the existing bending system.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
• /
• pp.451-456
• /
• 2012

This study was carried out to evaluate thermal performance of the renewable hybrid heat supply system with solar thermal system and wood pellet boiler for Zero Carbon Green home of apartment houses. The hybrid heat supply system was set up at Korea Institute Energy Research in 2011. The system was comprised of the wood pellet boiler unit with heat capacity designed as 20,000 kacal/hr, a evacuated tubular solar collector 3.74 $m^2$ of aperture area at the $20^{\circ}$ install angle, a 0.3 $m^3$ hot water storage tank, a 0.15 $m^3$ hot water storage tank for space heating. Thermal performance tests for one-house of apartment house were carried out by hot water load and heating load in winter season through the hybrid heat supply system. As a result, hot water energy supplied by the hybrid heat supply system was 11kWh in a day. Solar thermal energy portion was 2.99kWh which is 27% of the total hot water energy supply. wood pellet boiler supply portion was 8.017kWh which is 73% of the total hot water energy supply.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회B
• /
• pp.2934-2939
• /
• 2008

We conducted a test of a direct burning of crude Jatropha oil (CJO) in a commercial boiler system. The fuel, crude Jatropha oil is not biodiesel which comes from transeterification process of bio oil, but it is pure plant oil. The higher heating value (HHV) of the CJO is 39.3 MJ/kg (9,380 kcal/kg) and is higher than that of a commercial heating oil, 37.9 MJ/kg. The kinematic viscosity of CJO is 36.2 mm2/s at $40^{\circ}C$ and 8.0 mm2/s at $100^{\circ}C$. The burner used in the test is a commercial burner for a commercial heatingoil and its capacity is 140 kW (120,000 kcal/h). We did a preliminary test whether the combustion is stable or not. The preliminary test was a kind of open air combustion test using the commercial burner with crude Jatropha oil. We found that the combustion can be stable if the crude Jatrophaoil temperature is higher than $90^{\circ}C$. We measured the flue gas concentration by using a gas analyzer. The NOx concentration is $80{\sim}100\;ppm$ and CO concentration is nearly 0 ppm at flue gas O2 concentration of 3.0 and 4.5%.

• 대한설비공학회지:설비저널
• /
• 제10권4호
• /
• pp.304-315
• /
• 1981

This paper presents, the result of the study for the fluctuant temperature of the out-side air adopting the heat pump system in seoul, Taejean, Taegu, Busan and Jejeu among principle cities in korea for the purpose of checking the heating capacity, Heat pump capacity (outlet capacity), Coefficient of performance and running cost in comparison with the supporting the energy for the boiler's operation. According to the supply temperature changes of the out door coil by the out side air-return air mixing ratio, the Coefficient of performance is increased from 3. 1 to 5.0. Particularly, in Taegu, it is necessary to adopt the heat pump system against the supplement heat supply on the full outside air intake in January of the heating period, and it was recognized that the running cost is cheaper than that of the Boiler use. At the same time, if it is able to get $25\%$ of return air of the inside in the Seoul, it could be saved its costs when we use the supplementary boiler. And I think it is necessary to the development.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
• /
• pp.237-238
• /
• 2012

Recently, an energy-saving due to the energy utilisation efficiency enhancement is important. In order to improve the heat efficiency of the general residential boiler, We performed an experiment of condensation heat transfer to air pre-heat exchanger adhered to the condensing boiler. In this research, We analyze the heat transfer performance through the hydrophilic surface treatment(plasma, etching). The results of the research, On plasma and etching treated surface, Overall heat transfer coefficient is displayed the tendency to increase.