• 제목/요약/키워드: Air flowrate

검색결과 130건 처리시간 0.02초

마이크로 터빈 연소기 주연소영역의 저 NOx 생성 특성 (The Low NOx Characteristics of the Primary Zone in Micro Turbine Combustor)

  • 손민규;안국영;이헌석;윤정중
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.155-160
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    • 2001
  • The low NOx characteristics have been investigated to develop the combustor for micro turbine. The lean premixed combustion technology was applied to reduce the NOx emission. The test was conducted at the condition of high temperature and ambient pressure. The combustion air which has the temperature of $450\sim650K$ were supplied to the combustor through the air preheater. The temperature and emissions of NOx and CO were measured at the exit of combustor, The exit temperature and NOx were increased and CO was decreased with increasing inlet air temperature. The premixing chamber can be operated very lean condition of equivalence ratio around 0.35. The NOx was decreased with decreasing the equivalence ratio. The CO was decreased with decreasing the equivalence ratio, but the CO was increased with decreasing the equivalence ratio below 0.4. But, at the very lean condition of equivalence ratio below 0.35 both NOx and CO were increased because of the flame unstability. The NOx was decreased and CO was increased with increasing inlet air flowrate. This results can be used to determine the size of combustor. Consequently the performance of combustor shows the possibility of the application to the gas turbine system.

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상용차 캐빈 내의 열전모듈에 의한 열유동 수치해석 (Numerical Analysis on the Thermal Flow by a Thermoelectric Module within the Cabin of a Commercial Vehicle)

  • 김장권;오석형
    • 동력기계공학회지
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    • 제16권5호
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    • pp.47-54
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    • 2012
  • The steady three-dimensional numerical analysis on the thermal flow using standard k-${\varepsilon}$ turbulence model was carried out to investigate the air cooling effect of a cooler on the cabin for a commercial vehicle. Here, the heat exchanging method of this cabin cooler uses the cooling effect of a thermoelectric module. In consequence, the air system resistance of a cooler within the cabin is about 12.1 Pa as a static pressure, and then the operating point of a virtual cross-flow fan considering in this study is formed in the comparatively low flowrate region. The discharging air temperature of a cooler is about $14{\sim}15^{\circ}C$. Moreover, the air cooling temperature difference obtained under the outdoor cabin temperature of $40^{\circ}C$ shows about $7{\sim}9^{\circ}C$ in a driver resting space and about $9{\sim}14^{\circ}C$ in the front of a driver's seat including the space of a driver's foot.

플라즈마 용사법을 이용한 원통형 고체산화물 연료전지의 요소피막 제조 (Fabrication of the Functional Coatings of a Tubular Solid Oxide Fuel by Plasma Spray Processes.)

  • 주원태;홍상희
    • 한국표면공학회지
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    • 제30권5호
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    • pp.333-346
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    • 1997
  • Plasma spray processes for functional coatings of tubular SOFC ( Soild oxide Fuel Cell).consisting of air electrode, oxide electrolyte, an fuel electrode, are optimized by fully saturated fractional factorial testing. Material and electric characteristics of each coating are analtsed by the implementation of SEM and optical microscope for evaluating microstructure and porosity, X-ray diffraction method for investigating compositional change between raw powder and sprayed coating, and Van der Pauw method for measuring electrical conductivity. LSM ($La_{0.65}Sr_{0.35}MnO_3$air electrode and Ni-YSL fuel electrode coatings have porosities of around 23~30% sufficient for effective fuel and oxidant gas supply to electrochemical reaction interfaces and electrical conductivities of around 90 S/cm and 1000 S/cm, respectively, enough for acting as current collecting electrodes. YSZ($ZrO_2-8mol%Y_2O_3$) electrolyte film has a high ionic conductivities of 0.05~0.07 S/cm at $1000^{\circ}C$ in air atmosphere, but appears to be somewhat too porous to reduce the thickness. for enhancing the cell efficiency. A unit tubular SOFC has beem fabricated by the optimized plasma spray processes for each functional coating and the cell. Its electrochemical chracteristics are investigated by measuring voltage-current and power density with variation of operationg temperature, radio of fuel to air gas flowrates, and total gas flowrate of reactants.

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2차 냉매로 천연냉매 R744를 사용하는 냉동시스템의 성능 특성 (Performance Characteristics of Refrigeration System Using R744 as a Secondary Refrigerant)

  • 이문빈;조환;윤정인;최인수;손창효
    • 동력기계공학회지
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    • 제18권4호
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    • pp.17-22
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    • 2014
  • In this paper, the performance characteristics of R404 indirect refrigeration system using R744 as a secondary refrigerant were investigated experimentally to obtain a optimum design data for this system. First, for the constant experimental conditions, the COP of R404A indirect refrigeration system using R744 as secondary refrigerants decreases with respect to the increases in R404A condensation temperature and temperature difference in R744 cooler. And, the COP of indirect refrigeration system using R744 as secondary refrigerants decreases slightly with decreasing the mass flowrate of R744.

미세먼지 간이측정기 현장 검사용 시험 입자 발생기 개발 및 성능 평가 (Development and performance evaluation of a test particle generator for a field inspection equipment of PM-2.5 sensors)

  • 정혁;박진수
    • 한국입자에어로졸학회지
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    • 제18권3호
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    • pp.61-68
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    • 2022
  • In this study, a fluidized bed particle generator was developed to generate an aerosol without supply of compressed air and to increase portability. It was assumed that the mixing ratio of the test particles and beads, the input amount, and the air flow rate supplied to the generator would have effect on the aerosol generation characteristics. The product of these three parameters was set as a characteristic parameter and particle generation characteristics according to the change of the characteristic parameter were observed. As a result, it was confirmed that the input amount of test particles and beads was not suitable as a characteristic parameter and a characteristic parameter expressed as a product of the mass mixing ratio and the air flowrate was newly defined. When the new characteristic parameter is applied, it can be confirmed that the total amount of particles generated from the particle generator is a function of the characteristic parameter. As a result of measuring the amount of particle generation by adjusting the characteristic parameter, it was confirmed that the performance required for the test particle generator for the field inspection equipment of PM-2.5 sensors could be satisfied.

공기주입 노즐관이 장착된 관형막의 투과특성 (Permeation Characteristics of the Tubular Membrane Module Equipped wtih the Air Injection Nozzle Tube)

  • 박미자;정건용
    • 멤브레인
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    • 제27권1호
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    • pp.43-52
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    • 2017
  • 분리막 오염을 감소시키고 투과유속 향상을 위하여 관형분리막 모듈 내에 공기 분사노즐관을 삽입시켰다. 분리막의 평균 기공크기는 $0.1\;{\mu}m$이며 이스트를 오염물질로 사용하였다. 모든 투과실험은 노즐관을 모듈에 장착하고 공기를 주입하지 않는 실험을 먼저 실시하고 연속해서 공기를 주입하는 투과실험을 하였다. 그 다음 노즐관을 제거한 후 공기를 주입시키지 않으면서 투과유속을 측정하였다. 측정된 투과유속은 공기주입 효과를 분석하기 위하여 비교하였다. 공기주입에 대한 투과유속은 거의 일정하거나 증가하였다. 노즐관이 장착되고 공기 주입을 하지 않을 경우의 투과유속이 빈 관형 모듈의 경우보다 높았다. 운전압력을 0.4 bar까지 감소시키면 노즐관이 장착되지 않는 경우와 비교하여 공기를 주입할 경우 투과유속이 21%까지 향상되었다. 기체량이 증가하여 기/액체 2상 흐름이 stratified-smooth에서 intermittent 상태로 변화됨에 따라서 공기 주입에 의한 투과유속은 30% 이상으로 증가하였다.

HFC134a를 사용한 열펌프 건조기의 성능에 관한 실험적 연구 (An Experimental Study on the Performance of Heat Pump Assisted Batch Dryer Using HFC134a)

  • 김영중;임장순
    • 태양에너지
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    • 제17권2호
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    • pp.3-11
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    • 1997
  • 열펌프건조기는 증발기에 의한 냉각및 감습기능과 응축기에 의한 가열기능을 대류형건조기와 연계시킴으로써 필연적 손실로 분류되던 배기가 갖고 있는 현열과 잠열을 회수하여 재활용할 수 있는 이점이 있다. 본 연구에서는 HFC134a를 냉매로 사용한 배치형(batch type) 열펌프건조기를 설계제작하여 건조실의 유지온도, 공기의 바이패스비(bypass ratio), 냉매의 과열도를 일정하게 유지하고 정면풍속(face velocity)과 압축기속도를 변화시켜 건조기의 성능을 분석하였으며 정면풍속의 증가에 따라 열펌프의 성적계수는 증가하나 SMER(Specific Moisture Extraction Rate)은 감소하였다.

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다구찌 방법에 의한 PAC 실내기 유로의 최적설계 (Optimum Design of an Indoor Package Air-Conditioner's Flow Path by Taguchi Method)

  • 김장권;오석형
    • 동력기계공학회지
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    • 제18권1호
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    • pp.32-37
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    • 2014
  • In this study, the optimum design process of an indoor package air-conditioner (PAC) was implemented by Taguchi method. The goal of this study is to obtain the best set condition of each control factor composing of an indoor PAC. The number of revolution of a double inlet sirocco fan installed in an indoor PAC was measured by the orthogonal array of $L_{18}(2^3{\times}3^4)$ and analysed by using the-smaller- the-better characteristic among the static characteristic analyses. As a result, the optimum condition of an indoor PAC was found as a set of when the cost of production, assembling and working conditions were considered. Moreover, the number of revolution of a double-inlet sirocco fan used for an optimum condition was reduced about 8.5% more than that of a standard condition for the target flowrate of $18.5m^3/min$.

가솔린 엔진에서의 냉각수로의 전열량에 대한 연구 (A Study on the Heat Rejection to Coolant in a Gasoline Engine)

  • 류택용;신승용;이은현;최재권
    • 한국자동차공학회논문집
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    • 제5권6호
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    • pp.77-88
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    • 1997
  • The heat rejection to coolant is a dominant factor for building vehicle cooling system such as radiator and cooling fan. Since the vehicle cooling system also has effects on fuel consumption and noise, the study of heat rejection to coolant has been emphasized. However, the study on heat rejection to coolant has been mainly focused on the field that related to the characteristics of combustion and localized heat loss. It is no much of use in design for the entire cooling system because it is focused on such a specific point. In this work, the heat rejection rate to coolant for four different engines are obtained to derive a simple heat transfer empirical formula that can be applied to the engine cooling system design, and it is compared with the other studies. Also, to observe effects of engine operation factors and heat transfer factors on coolant, we measured the metal temperature and the heat rejection rate. The heat rejection to coolant does not depend significantly upon the coolant flowrate, but mainly upon the amount of air fuel mixture and the air fuel ratio as long as the composition of coolant does not change. The reduction of heat rejection to coolant did not effectively improve the fuel consumption, but was mostly converted to raise the exhaust gas temperature and the oil temperature.

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축산폐수 고도처리를 위한 미세조류 Scenedesmus acuminatus의 이용 가능성 (Potential Use of Microalgae Scenedesmus acuminatus for Tertiary Treatment of Animal Wastewater)

  • 박기영;임병란;이기세;이수구
    • 한국농공학회논문집
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    • 제53권1호
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    • pp.63-69
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    • 2011
  • The green algae Scenedesmus acuminatus was cultured in different media: animal wastewater and an artificial culture medium in order to evaluate potential use for tertiary treatment. The experiments were conducted with air flowrate 1~2 L/min at $28{\sim}30^{\circ}C$. The nitrogen and phosphorus showed very similar removal efficiencies (68~77 % and 69~80 % for nitrogen and phosphorus respectively). The optimal fed period was estimated as three days in the semi-continuous experiment. The effects of $CO_2$ (4.5 %) injection on nutrient uptake from animal wastewater (biological treatment effluent) were compared to an air injection under the same conditions of light and photoperiod. The uptake rates of nutrient with air injection were observed 0.009 gN/gChl-a/day, 0.028 gN/gChl-a/day and T-P 0.003 gP/gChl-a/day for nitrate, total nitrogen and phosphorus respectively. The rates were enhanced by addition of $CO_2$ to 0.026 gN/gChl-a/day, 0.076 gN/gChl-a/day and T-P 0.018 gP/gChl-a/day. This study establishes that $CO_2$ addition during nutrient deprivation of microalgal cells may accelerate tertiary wastewater treatment.