Byung-Ju Lim

One-dimensional Numerical Analysis of the Effect of Seawater Feed Rate on Multi-effect Solar Stills

In a multi-effect solar distiller, a feeding rate of seawater to each effect should be decreased as the effect number is increased. In previous studies, the feed rate of seawater was not reduced evenly between the effects, which is unreasonable, since the thermal energy input of each effect decreases by the same amount. In this work, numerical analysis was carried out in order to elucidate this discrepancy. The results showed that the amount of distillates produced was almost the same for both evenly and unevenly reduced flow rates between the effects. Optimum feed rates of seawater with various energy inputs from exhaust gas heat exchanger were also obtained. The results showed that the optimum feed rate of the first effect increased linearly or reached a steady state depending on the heat flux. 이 논문은 대한기계학회 창립 주년 기념 70 학술대회 제주 발표논문임 (2015. 11. 10-14., ICC ) . Corresponding Author, bzoo77@kimm.re.kr 2016 The Korean Society of Mechanical Engineers C 임병주 유상석 박창대 정경열 · · · 478 b 베이진 해수 : c 대류 : d 전도 : e 증발 및 응축 : g 배기가스 : i 효용단의 순서 : in 입구 : out 출구 : pi 번째 평판 : i r 복사 : wi 번째 윅 : i

Parametric performance test of distiller utilizing solar and waste heat

AbstractA seawater distiller utilizing the thermal energy of solar radiation and waste gas from a small electric generator was designed and constructed with a number of configurations to improve its performance. The distiller constructed is a combined model of a basin-type solar still and a vertical multiple-effect diffusion still, consisting of a series of closely spaced parallel plates in contact with saline-soaked wicks. Evaporation and condensation processes were repeated on all the plates by recycling thermal energy to increase distillate productivity in the still. Tests were performed with waste heat of actual exhaust gas from a portable electric generator, changing various experimental conditions such as feeding flow rate of seawater to the wicks, seawater level of the basin, and use of reflecting plate fins. Experimental results show that our two-effect distiller produces 17.1–19.6u2009kg/(m2u2009d) at 3,000u2009kJ/h and has a Performance Ratio of 14.8–16.9.

Design and implementation of the fault data providing system using mobile web service

Today electricity is essential to the modern people as one of the most important resources. Due to the increasing demand for electivity, the electric power system became complicated and huge on a scale. People want to be supplied with stable electricity with good quality. To be supplied with stable and good electricity, first generating facilities are required to operate without problems. In addition, a quick response is needed when the facilities are out of order. The fault data of generating facilities is very important. If users make the good use of this information, it will help users operate and repair/maintain generating facilities. Therefore, in this paper we propose the fault data providing system using mobile web service. Our proposed system enables users to access the fault data using web browsers, so that he/she can access the fault data from all types of mobile devices and personal computers.

Procedure and Method of Equipment Qualification for Solenoid-Operated Valves Used in Nuclear Power Plants

Key Words: Solenoid Operated Valve(솔레노이드밸브), Equipment Qualification(기기검증), Power Operated Valve(동력구동밸브), Nuclear Power Plant(원자력발전소)초록: 원자력발전소용솔레노이드밸브의국산화에필수과정인기기검증기술을개발하기위해관련규정을분석하고, 시험절차및방법, 시험조건, 시험장치및허용기준등을구체화하였다. 솔레노이드밸브의기기검증규격은법규, 가이드, 규정등의순으로계층화되어있으며, 시험기기와시험항목에따라규정이세분화되어있다. 세부규정인IEEE를분석한결과기기검증시험은크게기능시험, 일반환경시험및사고시험으로구분되어있는데, 일반환경시험과사고시험을통해발전소환경과동일한조건에서솔레노이드밸브를노화시킨후기능시험에서노화된밸브의성능을확인하는방식으로검증시험을수행하도록구성되어있었다. 본논문에서제시한솔레노이드밸브의기기검증시험절차와방법은기기검증수행자뿐만아니라밸브제조사에게매우유용한기술자료가될것으로판단된다.Abstract: In order to develop technology for an equipment qualification (EQ) test, which is an importantprocess in localizing solenoid-operated valves used in nuclear power plants, we analyzed related regulations,test procedures, conditions, equipment, and acceptance criteria. EQ regulations for the solenoid-operated valveare classified as law, guide, and standard, and are subdivided according to test specimens and contents. TheEQ test is composed of functional, normal-, and accident- condition tests. The solenoid-operated valve is agedunder normal and accident conditions, which are predicted in the design conditions of a nuclear power plant,and the performance of the valve is measured by a functional test. The test method and procedure analyzedin this paper might be very useful for manufacturers as well as EQ testers.