• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.421-426
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• 2009

This paper describes on energy loss in a pipe of refuse collecting system. Analysis energy loss in a pipe is the decisive factor in a design for refuse collecting system. From the analysis energy loss, we can determine the capacity of turbo blower. The flow characteristics in the pipe with the refuse bag are analyzed by three-dimensional Navier-Stokes analysis. The refuse bag is modeled using the actual measurement. We obtain friction factor by changing refuse bag's size and mixing ratio and Reynolds number. And From the result we calculate energy loss by using compressible flow analysis.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.399-404
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• 2008

Condensing gas boiler units may make a big role for the reduction of energy consumption in heating industries. In order to decrease the energy consumption of a condensing gas boiler unit, the effective control of the system is necessary. In this study, control algorithms of a condensing gas boiler were developed. Control algorithms are composed of the setpoint algorithm and the control algorithm. The setpoint algorithm consists of the supply water temperature setpoint algorithm and the pump setpoint algorithm. The control algorithm consists of the gas valve control algorithm and the blower control algorithm. In order to analyse the performance of control algorithms, dynamic models of a condensing gas boiler system were used. Simulation results showed that control algorithms developed for this study may be practically applied to the condensing gas boiler.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.128.2-128.2
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• 2010

For stationary 1kW-class fuel cell systems to be used widely, it is essential to achieve dramatic improvements in system durability as well as cost reduction. In order to address this engineering challenge, it is important to develop innovative technologies associated with BOP components. According to this background, in 2009, the Korean Government and "Korea Institute of Energy Technology Evaluation and Planning(KETEP)" launched into the strategic development project of BOP technology for practical applications and commercializations of stationary fuel cell systems, named "Technology Development on Cost Reduction of BOP Components for 1kW Stationary Fuel Cell Systems to Promote Green-Home Dissemination Project". The objectives of this project are to develop fundamental technologies to meet these requirements, and to improve the performance and functionality of BOP components with reasonable price. The project consortium consists of Korea's leading fuel cell system manufacturers, BOP component manufacturers which technologically specialized, and several research institutions. This paper is to provide a summary of the project, as well as the achievements made through the 1st period of the project(2009~2010). Several prototypes of BOPs - Cathode air blowers, burner air blowers, preferential oxidation air blowers, fuel blowers, cooling water pumps, reformer water pumps, heat recovery pumps, mass flow meters, valves and power conditioning systems - had been developed through this project in 2010. As results of this project, it is expected that a technological breakthrough of these BOP components will result in a substantial system cost reduction.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.152-157
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• 2002

A cross-flow fan is widely used on many industrial fields: a blower for the general industry, mining industry, automobile and home appliances. The design point of the cross-flow fan is generally chosen by based on the region within low static pressure and high flow rate. It relatively makes high dynamic pressure at low speed because a working fluid passes through an impeller blade twice. However, it has low static pressure efficiency between $30\%$ and $40\%$ because of relative high impact loss. Recently, in the air-conditioning systems, the operating behaviors at the off-design points are highly regarded to broaden the application area for various air-cooling loads. Especially, at the low flow rate, there exists a rapid pressure head reduction, a noise increase and an irregular flow against a rearguider as a scroll of centrifugal fan. Numerical analyses are carried out for cross-flow fan including the impeller, the rearguider and the stabilizer. Numerical domains are discretized by hexahedral cells. Three-dimensional, unsteady governing equations are solved using FVM, SIMPLE algorithm, sliding grid system and standard k-$\epsilon$ turbulence model.

• 한국축산시설환경학회지
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• 제19권2호
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• pp.109-116
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• 2013

In this experiment, we hypothesized that pre-conditioning pig manure with microwave radiation can effectively eliminate moisture and consequently, cut down a need for expensive sawdust. For the experiment, pig manure/sawdust mixture of water content 79% was divided into 4 groups and each of them were treated with microwave for predetermined time periods, 5, 10, 15, 20 minutes. Subsequently, they were transferred to chambers (20 L) and aerobically composted. During the 2 weeks composting, air was supplied using blower (150 L per $1m^3$) and temperature and other variables were monitored continuously. When the data were analyzed, it was found, (1) moisture content was significantly decreased as radiation period extended. (2) weight reduction of compost after completion of composting was noticeably bigger in 15 min radiated group(31%), compared with 5 min (24.6%), 10 min (21.4%), 20 min (27.2%) radiated groups.