본 연구는 선박용 공기압축기의 상태기반보전 시스템에 필요한 이상치 탐지 알고리즘 적용에 대한 실험적 연구로서 고장모사 실험을 통해 시계열 전류 센서 데이터를 이용한 이상탐지 적용 가능성을 확인하였다. 고장 유형 10개에 대해 실험실 규모의 고장 모사 실험을 수행하여 정상 운전데이터와 고장 데이터를 구축하였다. 실험 결과 구축된 이상탐지 모델은 시계열 데이터의 주기에 변화를 유발하는 이상은 잘 탐지하는 반면 미세한 부하 변동에 대한 탐지 성능은 떨어졌다. 또한 오토인코더를 이용한 시계열 이상탐지 모델은 입력 시 퀀스의 길이와 초모수 조정에 따라 이상 탐지 성능이 상이한 것으로 나타났다.

In this theoretical study, a design and performance analysis theory of a micro flowrate and high pressure air-compressor is developed. The governing equations are from the gas state equation and fluid dynamic theories because the working fluid in the air compressor is in a gas phase. A case study was conducted to design a reciprocating type of air compressor which the target performance was 0.6liter/min in the volume flowrate with 5atg in air pressure at 1,600rpm rotational speed. Geometrical size of the model air compressor designed is 10mm in stroke, 20mm in bore with 4.79 compression ratio. From the performance analysis of the model compressor, it was found that the air volume flowrate produced was 0.6liter/min with 5.81atg in pressure. The design theory of a micro-size high-pressure air compressor developed in this study is expected to be very useful design tools in NANO technology industry.

왕복동식 압축기에서 피스톤과 커넥팅로드는 중요한 부분이다. 이러한 주요부에 기계적 부하가 과도하게 가해지면 해당 기부 속이 손상될 수 있으며, 교체하기도 쉽지 않고 비용도 많이 든다. 따라서 내구성과 수명에 영향을 미치는 요인을 분석할 필요가 있다. 본 연구의 주요 목적은 피스톤과 커넥팅로드의 최대 응력 집중 위치를 확인하는 것이다. 이를 위해 설계된 공기압축기의 작업 공정의 동적 계산을 기반으로 피스톤 및 커넥팅로드의 응력 분석을 수행하였다. 공기압축기의 피스톤과 커넥팅로드의 3 차원 모델을 따로 설계하고, 이러한 부품들의 유한요소 해석은 수치해석적인 근사해법을 사용하였다. 피스톤은 열 경계 조건 없이 크랭크 샤프트의 각도에 따라 압 력 부하를 받는다. 시뮬레이션 결과는 피스톤과 커넥팅로드의 응력 집중 위치와 그 값을 예측하고 추정할 수 있다. 그 결과 크랭크 각도 135°와 225°에서 피스톤은 190MPa, 커넥팅로드는 123MPa 이상의 최대 등가응력이 나타났으며 이는 인장 항복강도 이하의 값이다. 또한, 커넥팅로드와 피스톤에 계산 된 안전 계수는 1보다 높게 나타났다. 더욱이, 이러한 결과는 왕복동 공기압축기 제작사에 피스톤 및 커넥 팅로드를 설계함에 있어서 최적화를 위한 참고 자료로 활용 될 수 있다.

In this study, FLUENT v.16.1 was used to investigate the compressible flow generated by the supersonic jet spewed from a high pressure tube. As the boundary condition for CFD (Computational Fluid Dynamics) analysis, the inlet temperature of air was constantly 300 K and the variation of JPR (Jet Pressure Ratio) were 5, 50, 100, 150 and the variation of tube diameter were 10, 20, 30 cm. As a result, it was confirmed that the effective range was increased as the JPR was higher, but it was confirmed that the effective range was lower than the JPR rise, and that the effective range was increased as the diameter was larger. Therefore, it is found that the tube diameter is more sensitive than the JPR among the influence factors of jet, and if the result of this study were reflected in the design of high pressure system, it will contribute to the design of the system for preventing the second accident.

Pumps for hazardous materials handling areas of self service stations are still scattered in the country, generator room, engine room of the small vessels, etc. are installed inside buildings against big is the risk of fire extinguishers are installed only. These facilities are in severe climate change because it is an open space area, as well as a water based fire extinguishers may not be suitable for that type of gas extinguishing system is also adaptable. This study features a compressed air port operation principles and characteristics, equipment, fire extinguishers, which can minimize the casualties and property losses from fire against hazardous substances in small business, design requirements, domestic contain fire extinguishers laws and foreign Compression Four fire extinguishers through the air and foreign regulations comparative analysis of the compressed air port installations such as fire extinguishers and applied to study the measures to be included are fire extinguishers installed in the country. Climate change is a big country review In winter, water based fire extinguishers are also concerned about the freeze, but compared to the foreign installations were exploring ways to work in the country. CAF is especially preferred that the fire extinguishing performance and to demonstrate the protective space as there is a risk of frost risk significantly less compressed air port digestion plant.

Optimizing energy usage for maximum efficiency is an essential goal for manufacturing plants in every industrial manufacturing sector. The generation and distribution of purifying compressed air is a large expense incurred in practically all manufacturing processes. Not only is the generation and treatment expensive equipment of compressed air, but frequent maintenance and effective operation is also required. As a plant’s compressed air system is often an integral part of the production process, it needs to be reliable, efficient, and easy to be maintain. In this paper, we study to find operating method to save energy from the adsorption dryer in the process of purifying compressed air, which is required for a clean room production site in “A” company. The compressed air passes through a pressure vessel with two “towers” filled with a material such as activated alumina, silica gel, molecular sieve or other desiccant material. This desiccant material attracts the water from the compressed air via adsorption. As the water clings to the desiccant, the desiccant particle becomes saturated. Therefore, Adsorption dryer is an extremely significant facility which removes the moisture in the air 70℃ below the dew point temperature while using a lot of energy. Also, the energy consumption of the adsorption dryer can be varied by various operating conditions (time, pressure, temperature, etc). Therefore, based on existing operating experiments, we have searched operating condition to maximize energy saving by changing operating conditions of the facility. However, due to a short experiment period (from September to October), further research will be focused on considering seasonality.

The adoption of scroll type air compressor is gradually increased in the automotive/residential air-conditioner and clean air compressor, and the most of critical components of the scroll are made of aluminum to reduce the friction and weight. Many studies for the surface treatment of the aluminum have been performed to reduce the friction between the components. In the preceding research, we suggested the most appropriate combination of the solid lubricant. In this study, we coated the part of fixed or orbiting scroll wrap with the solid lubricant that suggested in the preceding research, and then have performed analysis of performance characteristics for the part. As a result, we could obtain the 7.66μm of the coating thickness, Ra 0.8μm of the surface roughness and 0.088 of the friction coefficient. These represent the satisfactory capability of the suggested solid lubricant for the scroll type air compressor.

The coating of solid lubricant on the part of fixed or orbiting scroll wrap in a scroll compressor can not only reduce friction loss, noise & vibration and time cost for surface finishing but also improve efficiency and performance of the compressor. In this study, we found the most appropriate combination of the solid lubricant by carrying out many measurements and tests such as coefficient of friction, surface structure, the coating thickness and surface roughness for the various cases. We have come to conclusion that the most appropriate solid lubricant can be obtained by adding WS2 3% to Base(SM 3901) without any solvent and filler.

Most systems used in industrial sites, actually have non-linearity and uncertainty. Therefore there are a lot of difficulties in evaluating conditions of these systems. Generally, the quantitative analysis and expression are found hard because the general public cannot easily make an accurate interpretation on the systems. Thus development of a system that utilizes an expertise from skilled analysts is required. In this research, a real-time sensor signal conditioning system and Fuzzy-expert system have been separately set up into an inference algorithm. So that it ensures a fast, accurate, objective and quantitative operational condition value provided to the manager. Therefore, FE_AFCDM is suggested in this literature, as an effective system for diagnosing the problems related to the air compressor. It can quantify the uncertain and absurd condition to operate the air compressor facilities safely and financially.

Air compressor is an important facility with electric power in the industry. However, because of the noise and vibration of air compressor and is installed outside the building management difficulty. In this study, MCP (Micro Control Processor) to remote monitoring of the air compressor via the compressed air through improved quality and allows stable maintenance were designed. So, increase the productivity improvement of energy-saving effect can be obtained. Remote real-time information stored on your PC to manage air compressor equipment was higher reliability. Monitoring system is developed in this study was applied to embedded systems. It is easy to install air compressor, and low maintenance costs was to raise the economic impact.

Micro bubbles are widely used in many cases such as agriculture, fishery, skin care, prevention of water pollution. A high pressure compressor which is one of part of a micro bubble generating system is needed to generate these micro bubbles. The purpose of this research is the development of a high pressure compressor which is achieve following conditions; discharge flow 0.6ℓ/min, maximum air flow 2ℓ/min, discharge pressure 5bar. To achieve these conditions, we optimized the geometry of cylinder and piston, clearance volume, compression ratio, power of operating motor experimentally. Moreover, we minimized the compressor which is the biggest part of a micro bubble generating system so that we could minimized the size of entire system.

Numerical modeling was used to evaluate the submerging characteristics of the submersible fish cage system operated by compressed air. The submerging characteristics calculated by numerical analysis as the cage was moved up and down were nearly identical to existing experiment results. Thus, the numerical model proposed in this study could be very useful in analyzing various parameters required for optimizing the design of a submersible fish cage system operated by compressed air.

압축공기에 의한 기포막을 어구로 활용하기 위한 기초 자료를 제공하고져 압축공익의 세기별, 기포 발생 호스 구명의 크기별, 간격별 기포막의 특성과 기포 소음의 음향학적 특성을 실험, 분석한 결과는 다음과 같다. 1. 공기 압축기(290l/min×1.5Kw)와 용량 10kgf/cm2인 공기 탱크로 구성한 기포막 발생 장치로써 발생시킨 기포막은 송기압이 0.2kgf/cm2이상이 되어야 형성되고, 구멍의 크기보다는 구멍 간격이 넓어짐에 따라 더욱 높게 형성됨을 알 수 있었다. 2. 기포 발생시 음압은 구멍이 크고 간격이 조밀하며 기포막에 가까울수록 크며 기포 중심부의 주파수 변동폭은 구명이 적고 간격이 조밀할수록 높았다. 3. 기포막의 빔 각도는 유속에 비례하여 커지며, 유속이 0.1m/sec당 10˚씩 변화되었다. 4. 송기압을 0.5, 1.0, 1.5kgf/cm super (2)로 변화시키면서 기포 발생 호스를 수직방향으로 0˚, 10˚, 20˚로 각각 경사시켜 측정한 결과 기포막 수평길이는 기포막 발생 호스의 경사각도에 따라 그 길이를 최대 45% 연장 할 수 있었다.

The real size submersible fish cage(L×B×D, 3×3×6m)system consists of the compressed air equipment was made in order to control efficiently in case of heavy weather or environmental pollution such as red tide, and then carried out experiment on the submersible functions and safety for that cage at Koje inland sea in 14th June, 1995. The authors could confirm that the submersible cage was very stabilized it's submersible functions and safety when the cage was floating and sinking at sea.