• Title/Summary/Keyword: Air Cycle Machine

Search Result 33, Processing Time 0.033 seconds

A Study on the Operation Performance of Diesel Engine by using of Soybean Oil Fuel (디젤엔진의 콩기름연료에 의한 운전성능에 관한 시험)

  • 이기명
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.18 no.4
    • /
    • pp.4259-4264
    • /
    • 1976
  • This paper, is about the test on the operating performance of diesel engine by using of soybean oil which farmers could supply in their farm yard. The diesel engine used is a swirl-chamber type, four stroke cycle with single cylinder, air cooling and its rated horse power is 2 PS per 1300 rpm. Several results obtained are as follows; 1. The starting performance of diesel engine with soybean oil is almost the same as that with light oil. 2. The variation of engine speed according to various engine load is small when soybean oil is used compared with light oil. It is considered that soybean oil is desirable for the purpose of industerial power machine fuel. 3. The specific fuel consumption increases approximately 10 percent high in the condition of rated horse power and maximum horse power and shows less or same during the load test in low velocity, when soybean oil is used 4. Though the brake thermal efficiency in the condition of rated horse power and maximum horse power is inclined to decrease when soybean oil is used compared during the load test in low velocityt shows good inclination.

  • PDF

Fabrication and Study on the Performance Characteristics of a Scroll Expander for Organic Rankine Cycle (유기랭킨사이클용 소형 스크롤 팽창기 제작 및 성능 특성 연구)

  • Baek, Seungdong;Sung, Taehong;Lee, Minseok;Kim, Kyung Chun
    • Journal of the Korean Institute of Gas
    • /
    • v.20 no.5
    • /
    • pp.50-56
    • /
    • 2016
  • In this work, the open-drive oil free air compressor is modified to activate an organic Rankine cycle system as an expanding machine. The shape of the modified scroll expander case is a rectangular parallelepiped and the size of the case is $0.0394m^3$. The scroll expander is operated in an ORC using R245fa as working fluid with various working conditions for the performance test. The test data points are used to calculate the parameters of the scroll expander semi-empirical simulation model. The simulation results are compared with the experimental results to validate the simulation model.

Effect of creep-fatigue interaction on high temperature low cycle fatigue strength and fracture behavior of STS 316 stainless steels (STS 316鋼 의 高溫低사이클 疲勞强度 와 破壞擧動 에 미치는 크리이프 - 疲勞 相互作용 의 影響)

  • 오세욱;이규용;김중완;문무경
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.9 no.2
    • /
    • pp.140-149
    • /
    • 1985
  • Fully reversed push-pull low cycle fatigue tests under strain control of trapezoid cyclic mode have been conducted in air at temperature of 550.deg. C and with frequency of 0.5 cpm on the domestic stainless steel STS 316 after solution treatment for 1 hour at 1100.deg. C. As an experimental equipment for high temperature fatigue tests, an electric servo-hydraulic fatigue machine(Instron model 1350) was used. This paper presents the effects of creep hold time and plastic strain range on push-pull high temperature low cycle fatigue life and fracture behavior. The fracture surfaces were observed by means of the scanning electron microscope. The results are as follows. (1) The fatigue life decreases with increase of the plastic strain range equal hold time and also decreases as the hold time is getting longer. (2) The frequency modified damage function can predict fatigue life by incorporating a variation of Coffin's frequency modified approach into damage function. (3) The ratios of creep damage and fatigue damage can be calculated by using he linear accumulation damage concept and the ratio of creep damage increases as the hold time is getting longer. (4) At the creep hold time of 5 minutes and the strain range of 2.0%, the fracture mode was intergranular fracture and striations were hardly observed. In this case, the intergranular cracking was originated in void type('.gamma.' type) cracking.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.27 no.7
    • /
    • pp.380-394
    • /
    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

Agile and Intelligent Manufacturing System for a Small IT Parts Assembly (초소형 IT 부품 조립을 위한 지능형 민첩 생산시스템)

  • Kim, Won;Kang, Heui-Seok;Cho, Young-June;Jung, Ji-Young;Suh, Il-Hong
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.13 no.5
    • /
    • pp.499-506
    • /
    • 2007
  • The tiny camera module used in a modern cellular phone requires precise assembly processes. To meet the requirement of high resolution and functionality, the number of parts used in a camera module becomes larger and larger. As the market grows rapidly, an automatic camera phone assembly process is required. However, diverse production line and short life cycle make it difficult to build an affordable assembly line. To attack this problem, a flexible and expandable lens assembly system is proposed. To save the manufacturing line set-up time, modular concept is adopted. Also, each module is designed to have intelligence to simplify the set-up process. The assembly system is built up on the standard flat-form that includes a vibration free base, air and electric supplies, and electronic controllers, etc. Furthermore, the assembly cell has the capability of handling tiny, thin, or transparent parts which are very difficult to identify without machine vision.

A Study on a Method for Detecting Leak Holes in Respirators Using IoT Sensors

  • Woochang Shin
    • International journal of advanced smart convergence
    • /
    • v.12 no.4
    • /
    • pp.378-385
    • /
    • 2023
  • The importance of wearing respiratory protective equipment has been highlighted even more during the COVID-19 pandemic. Even if the suitability of respiratory protection has been confirmed through testing in a laboratory environment, there remains the potential for leakage points in the respirators due to improper application by the wearer, damage to the equipment, or sudden movements in real working conditions. In this paper, we propose a method to detect the occurrence of leak holes by measuring the pressure changes inside the mask according to the wearer's breathing activity by attaching an IoT sensor to a full-face respirator. We designed 9 experimental scenarios by adjusting the degree of leak holes of the respirator and the breathing cycle time, and acquired respiratory data for the wearer of the respirator accordingly. Additionally, we analyzed the respiratory data to identify the duration and pressure change range for each breath, utilizing this data to train a neural network model for detecting leak holes in the respirator. The experimental results applying the developed neural network model showed a sensitivity of 100%, specificity of 94.29%, and accuracy of 97.53%. We conclude that the effective detection of leak holes can be achieved by incorporating affordable, small-sized IoT sensors into respiratory protective equipment.

Development of a Garlic Peeling System Using High-Pressure Water Jets (IV) - Structure and performance of a full-scale system in operation - (습식 마늘박피 시스템 개발 (IV) - 상업용 시스템의 구조와 성능 -)

  • Bae Y. H.;Yang K. W.;Baik S. K.;Kim J.;Chang Y. C.;Lee S. H.
    • Journal of Biosystems Engineering
    • /
    • v.30 no.1 s.108
    • /
    • pp.25-31
    • /
    • 2005
  • There are more than three hundred garlic peeling facilities in Korea and most of them use pressurized air for skin peeling operation. One of the major problems of using air for the peeling operation is the occurrence of excessive bruises on the flesh of peeled garlic which causes easy microbial contamination and shortening of the shelf lift. To reduce the occurrence of bruises during the peeling operation, a new type of garlic peeling system was developed which use pressurized water. In this system, high pressure water jets were used to separate garlic bulbs and to peel the skin of garlic cloves. Six commercial systems of this type had been developed and installed at several locations in Korea. The design and performance of the latest system according to three pressure levels were described in this paper. Peeling efficiency of the system was as high as $64.7\%$ in one cycle of peeling operation by three chambers installed in series. Incorporation of a sorting system based on machine vision and re-circulation of unpeeled and partially-peeled garlic enhanced peeling efficiency by additional $30\%$, resulting in total peeling efficiency of the final products of approximately $95\%$. Peeling capacity of the system was over 400 kg per hour.

An Experimental Study of Evaporative Heat Exchangers with Mini-channels (물의 증발잠열을 이용하는 미니채널 열교환기의 실험적 연구)

  • Lee, Hyung-Ju;Yoo, Young-June;Min, Seong-Ki
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2010.11a
    • /
    • pp.245-253
    • /
    • 2010
  • The present study shows some results of developing evaporative heat exchangers with mini-channels. Heat exchangers with three different water paths were manufactured and tested to compare performances of cooling and pressure drop. Among the three types of heat exchangers, Type 2 with full-etching was proved to be the best in the cooling performances for considered operating conditions, and thus it is recommended to adopt Type 2 for its simplicity of production and outstanding performance. However, Type 1 was shown to be better when it is operated at a high air inlet temperature condition. The developed evaporative heat exchanger will be installed in Environmental Control Systems(ECSs) for aerial vehicles, and it can be used effectively in case an ECS is not only limited in its weight and volume but also required to absorb heats without supplying water (or a coolant) for a certain period of time.

  • PDF

Optimization of the Scraper Speed and Improvement of the Refrigerant Path for the Evaporator of the Soft Ice Cream Machine (소프트 아이스크림 제조기 증발기의 스크레이퍼 회전수 최적화 및 냉매 유로 개선)

  • Baek, Seung-Hyuk;Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.10
    • /
    • pp.8-14
    • /
    • 2017
  • Improvements in the standard of living and lifestyle have led to increased sales of frozen milk products, such as soft ice cream or slush. These frozen milk products are commonly made in a small refrigeration machine. In a soft ice cream machine, the freezer is composed of a concentric cylinder, where the refrigerant flows in the annul us and the ice cream is made in the cylinder by a rotating scraper. In this study, an optimization and performance evaluation were conducted on a soft ice cream machine having a freezer volume of 2.8 liters. The optimization was focused on the scraper rotation speed and the refrigerant path of the freezer. The measurements included the temperature, pressure and consumed power. At the optimized speed of 124 rpm, ice cream was produced in 6 minutes and 2 seconds, and the COP was 0.90. Through a flow visualization study using air-water, the refrigerant path was improved. The improved design reduced the ice cream making time significantly. The present results may be used for the optimization of other refrigeration cycles, including those of frozen food products.

Evaluation of Characteristics and Reliability of an Auger Crane with Built-in Hydraulic Extender (유압식 확장기가 내장된 오거 크레인의 특성 및 신뢰성 평가)

  • Kim, Jeom-Sik;Kwon, Sin-Won
    • The Transactions of the Korean Institute of Electrical Engineers P
    • /
    • v.59 no.1
    • /
    • pp.77-82
    • /
    • 2010
  • This study evaluated the characteristics and reliability of an auger crane with a built-in hydraulic extender. The field test of the hydraulic extender was performed with the hydraulic lines filled with hydraulic fluid and free of air. The pressure generated during the test was measured with a digital pressure gauge. The crane was considered to have undergone one cycle of the excavation process after it had performed excavation under three conditions at the same location. This process was performed three times in total. From the results of the excavation using the hydraulic extender, it was found that the maximum pressure and torque measured were 19.9 [MPa] and 895.4 [$kgf{\cdot}m$], respectively. The rotation force of the auger crane generated at this time signifies a horizontal force. If the excavation diameter of the auger crane is increased, the rotation speed is reduced causing the circumferential speed to also be reduced. The torsional shear stress of the extendable auger crane was calculated to be approximately 23.5 [MPa]. However, the rotation shaft material used for this system was carbon steel for machine structural use (SM45C). Since the minimum torsional yield stress is greater than 150 [MPa] according to KS D 3752, it means the equipment has secured a safety factor greater than 6. Therefore, it was found that when performing work using the extendable auger crane, it exhibited no problems with the safety and reliability of its shaft.