• Journal of Biosystems Engineering
• /
• v.25 no.3
• /
• pp.221-226
• /
• 2000

Hot air heater with light oil burner is the most common heater for greenhouse heating in the winter season in Korea. However, since the thermal efficiency of the heater is about 80∼85%, considerable unused heat amount in the form of exhaust gas heat discharges to atmosphere. In order to capture this exhaust heat a heat recovery system for plant bed heating in the greenhouse was built and tested in the hot air heating system of greenhouse. The heat recovery system is made for plant bed or soil heating in the greenhouse. The system consisted of a heat exchanger made of copper pipes, ${\Phi}12.7{\times}0.7t$ located in the rectangular column of $330{\times}330{\times}900mm$, a water circulation pump, circulation plastic pipe and a water tank. The total heat exchanger area is 1.5$m^2$, calculated considering the heat exchange amount between flue gas and water circulated in the copper pipes. The system was attached to the exhaust gas path. The heat recovery system was designed as to even recapture the latent heat of flue gas when exposing to low temperature water in the heat exchanger. According to the performance test it could recover 45,200 to 51,000kJ/hr depending on the water circulation rates of 330 to $690\ell$/hr from the waste heat discharged. The exhaust gas temperature left the heat exchanger dropped to $100^{\circ}C$ from $270^{\circ}C$ by the heat exchange between the water and the flue gas, while water gained the difference and temperature increased to $38^{\circ}C$ from $21^{\circ}C$ at the water flow rate of $690\ell$/hr. By the feasibility test conducted in the greenhouse, the system did not encounter any difficulty in operations. And, the system could recover 220,235kJ of exhaust gas heat in a day, which is equivalent of 34% of the fuel consumption by the water boiler for plant bed heating of 0.2ha in the greenhouse.

• Proceedings of the SAREK Conference
• /
• 2005.11a
• /
• pp.121-128
• /
• 2005

This is about experimental comparison study between convective heating and radiation heating system to use the design criteria for residential house. Experiment was done in EC(environment chamber) under simultaneous outdoor condition for 4 kinds of heating system such as CRHP(Ceiling Radiant Heating Panel), BEHC( Bottom Electric Heating Coil Mat), EFCU( Electric Fan Coil Unit) and CEHU( Convective Electric Heating Unit). Result show that CRHP ,which is radiation heating system, can consume more 23% energy than convective heating system when it is operated by dry bulb temperature but can save 1 ${\sim}$ 10% when operated by glove temperature and 27% when operated by MRT.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1438-1440
• /
• 2005

A power control and distribution unit(PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU scheme for the small LEO Satellite applications. The main constitutes of the PCDU are the battery interface module, the auxiliary supply modules, solar array regulators with maximum power point tracking(MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation. and instrument power distribution modules.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.12
• /
• pp.6072-6081
• /
• 2013

In this study, experiments were performed on air heater samples with three different shapes (chevron, wave and dimple type) to reduce the plumes from cooling towers. The tests were conducted for a range of frontal air velocities of 1~3 m/s and water flow rate 0.19~0.33 kg/s. The results showed that the heat transfer rate increased with increasing air velocity or water flow rate. The air-side pressure drop also increased with increasing air velocity. At the same frontal air velocity, the highest heat transfer rate was obtained for the chevron sample (1.5~1.7 times compared to that of the plate sample), followed by the dimple, wave and plate samples. The heat transfer rate per unit power consumption was also 15% larger than that of the dimple sample. On the other hand, there was no noticeable difference between the other samples.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.10 no.5
• /
• pp.481-487
• /
• 2005

Proposed induction-heated system is innovative system which applied special high-frequency power circuit technique for thermal converse technique and IH(Induction-Heating) magnetic induction heating generated from induction-heated metallic package that is for distillation unit. In this occurs not burning, so that the working environment can be improved. This electromagnetic induction heating technique is used high frequency inverter, By using high frequency inverter high frequency alternative current in the range of [kHz] can be made with conventional alternative current. In this contribution IGBT module is used for high frequency inverter. This paper proposes new fluid heating method. Which is operated as follows. Working coil, which is wrapped outside of pipeline, makes the eddy current. Inside of heating vessel in isolated pipeline the specially designed stainless metallic package is inserted, which can be heated by eddy current losses. And then In this paper are discussed action analysis and characteristics analysis of 5[kW] class full-bridge resonant inverter system and resonant metallic package. In addition, by using this system, how high-efficiency heater is developed and application of system are also discussed.

• Journal of Environmental Science International
• /
• v.13 no.7
• /
• pp.703-710
• /
• 2004

Petroleum refineries have been considered as an important emission source for atmospheric volatile hazardous air pollutants(HAPs). The emission source includes petroleum refinery processes and process equipment. The control strategy for volatile HAPs requires emission estimations of these pollutants. However, systematic methods of volatile HAPs emission from petroleum refineries have not yet been established. Accordingly, present study surveyed the estimation method of volatile HAPs emitted from the petroleum refinery processes and process equipment. The emission estimation methods for the petroleum refinery processes are applied for 11 petroleum refining facilities: fluidized catalytic cracking, thermal cracking, moving bed catalytic cracking, compressed engine, blowdown system, vacuum distilled column condensator, natural gas or distilled boiler, natural gas or distilled heater, oil boiler, oil heater and flare. Four emission estimation methods applied for the petroleum refinery process equipment are as follows: average emission factor approach, screening ranges approach, EPA correlation approach and unit-specific correlation approach. The process equipment for which emission factors are available are valves, pump seals, connectors, flanges and open-ended lines.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.38 no.5
• /
• pp.106-115
• /
• 1996

This study was carried out to provide fundamental data for reuse of resources and prevention of environmental pollution Actual states of environmental pollution by biological production facilities were investigated. Various pollution loads and quantity of wastes from greenhouse and animal housings estimated. In greenhouse contents of investigation were wastes of plastic cover, noise of heater and fan, air pollutant of heater, and wastes of soilless culture system, etc. In animal housings, those were actual state of livestock waste treatment and reuse, pollutant mass unit discharge, noise pollution, and malodorant, etc. The main pollutants discharged from greenhouses were wastes of plastic cover, rockwool, and waste fluid of nutrient solution. Developments of waste disposal methods for plastic cover and rockwool are required. And recycle technique of nutrient solution for soilless culture should be developed and propagated. With the buildup of legal control, pollutant mass discharged from livestock wastes are, on the decrease. The other side, reuse of livestock excreta increased. Most animal housings are located near the dwelling house. Malodorant and noise from animal housings have bad effects on the rural living conditions. So developments of integrated complex for small scale livestock farms are required.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.2
• /
• pp.17-22
• /
• 2014

Recently, the quick heating performance is an important issue in the car because engine power becomes so high. So car makers have been adapted the additional heating devices as like PTC(Positive Temperature Coefficient) heater. And the quick cooling performance is also important issue because its result is used in the IQS(Initial Quality Study). In this paper, control of the HVAC(Heating, Ventilation and Air Conditioning) intake door has been studied for the quick heating and cooling performance. Heating performance is improved $4.0^{\circ}C$ at $-20^{\circ}C$ ambient temperature after 20 minutes. And cooling performance is improved $1.5^{\circ}C$ at $35^{\circ}C$ ambient temperature after 10 minutes. In addition, intake door control system brings on the cost reduction because the flab door can be eliminated. This intake door control system has been adapted to the new developing cars.

• Journal of Biosystems Engineering
• /
• v.40 no.3
• /
• pp.250-260
• /
• 2015

Purpose: Dual cylindrical microwave chambers equipped with an ohmic heating tube were designed and fabricated to maximize the electric field strength for expeditious heat treatment of particulate foods. Methods: The efficacy of the combination heater was investigated by simulating the electric field distribution by using COMSOL Multiphysics software. Results: All components of the designed microwave heating unit were suitable for transmitting maximal microwave power to the load. The simulated electric field distribution implied that single-mode microwave heating would be sufficient for the steady generation of a highly localized heating zone in the cavity. During impedance matching, the calculated reflection coefficient ($S_{11}$) was small, possibly implying minimal power loss and wave reflection in the designed microwave heating chamber. Conclusions: This study demonstrates the possibility of concentrating the microwave power at the centerline for a single-frequency microwave, for thermal treatment of multiphase foods without attenuating the microwave power.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.90-93
• /
• 2009

Recently, CAN(Controller Area Network) being used in vehicle network system is suitable Network Protocol for smart vehicles with a future that need many ECUs, and it guarantees stability and reliability. It is revealed that being equipped many ECU could reduce the increasing of energy consumption and energy cost from the increasing of Wiring Harness's space and weight. In this paper, future smart vehicle control Air conditioner and heater for convenient and comfortable driving as using CAN protocol and implement auto control system According to driver's requirement using temperature in the vehicle.