• 제목/요약/키워드: Instantaneous exhaust

검색결과 17건 처리시간 0.026초

벌크 트레일러의 순간 및 누적 분말 배출량 추정을 위한 신경망 모델 성능 비교 (Performance Comparison of Neural Network Models for the Estimation of Instantaneous and Accumulated Powder Exhausts of a Bulk Trailer)

  • 이창준;이정근
    • 센서학회지
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    • 제32권3호
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    • pp.174-179
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    • 2023
  • Bulk trailers, used for the transportation of powdered materials, such as cement and fly ash, are crucial in the construction industry. The speedy exhaustion of powdered materials stored in the tank of bulk trailers is relevant to improving transportation efficiency and reducing transportation costs. The exhaust time can be reduced by developing an automatic control system to replace the manual exhaust operation. The instantaneous or accumulated exhausts of powdered materials must be measured for automatic control of the bulk trailer exhaust system. Accordingly, we previously proposed a recurrent neural network (RNN) model that estimated the instantaneous exhaust based on low-cost pressure sensor signals without an expensive flowmeter for powders. Although our previous study utilized only an RNN model, models such as multilayer perceptron (MLP) and convolutional neural network (CNN) are also widely utilized for time-series estimation. This study compares the performance of three neural network models (MLP, CNN, and RNN) in estimating instantaneous and accumulated exhausts. In terms of the instantaneous exhaust estimation, the difference in the performance of neural network models was insignificant (that is, 8.64, 8.62, and 8.56% for the MLP, CNN, and RNN, respectively, in terms of the normalized root mean squared error). However, in the case of the accumulated exhaust, the performance was excellent in the order of CNN (1.67%), MLP (2.03%), and RNN (2.20%).

메탄올기관과 흡.배기 밸브에서의 열유속 특성 (Characteristics of Heat Flux in Intake and Exhaust Valve of Methanol Fueled Engine)

  • 김문헌;임연기;이종태
    • 한국자동차공학회논문집
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    • 제4권1호
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    • pp.208-217
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    • 1996
  • Instantaneous surface temperature and unsteady heat flux of intake and exhaust valve in methanol fueled engine were investigate as a function of compression ratio and engine speed. To accomplish this purpose, the instantaneous temperature sensor was designed and it was installed into three point of intake and exhaust valve head to measure unsteady temperature. The unsteady heat flux at valves was evaluated using one dimensional heat conduction equation with the valve head temperature and temperature gradient. And also mean heat flux of intake and exhaust valve for each stroke were evaluated as a function of engine speed.

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ANALYSIS OF GAS-DYNAMIC EFFECTS IN COMPACT EXHAUST SYSTEMS OF SMALL TWO-STROKE ENGINES

  • Galindo, J.;Serrano, J.R.;Climent, H.;Tiseira, A.
    • International Journal of Automotive Technology
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    • 제8권4호
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    • pp.403-411
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    • 2007
  • This article describes a methodology based on experiments and 1D modeling work related to the exhaust system analysis of a small two-stroke engine. The primary goal of this work was to understand how the design criteria of a compact exhaust system influenced the exhaust port pressure, since its evolution controls not only engine performance but also exhaust emissions. On the experimental side, a fully instrumented 50cc two-stroke engine was used to check the behavior of three different exhaust systems. A problem related to instantaneous pressure measurements in unsteady, hot flow was detected and solved during the study. To build the 1D model of the three exhaust systems, experimental information on the steady flow and the impulse test rigs was obtained under controlled conditions in specific facilities. Accurate comparisons between measured and calculated exhaust port instantaneous pressures were obtained from the following different exhaust system configurations: a straight duct, a tapered pipe and the three compact exhaust systems. The last step in the method used this model to analyze the pressure waves inside the exhaust system and detect the influence of the geometric parameters. The results should lead to improvements in the design process of complex compact exhaust systems in two-stroke engines.

DI 디젤기관 실린더 헤드표면의 순간온도 및 열유속 측정에 관한 실험적 연구 (An Experimental Study on the Measurement of Instantaneous Surface Temperature and Heat Flux on the Cylinder Head Surface of DI Diesel Engine)

  • 이재순;김기태;이현구;강태경;우종헌;김수성
    • 한국자동차공학회논문집
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    • 제5권5호
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    • pp.178-187
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    • 1997
  • For the experimental measurement of heat flux of DI diesel engine combustion chamber, the instantaneous temperature probes and data acquisition system were developed. By the analysis of measured temperatures at the cylinder head, the temperature at the point 3 which is located between intake and exhaust valve was higher than that of the other points. Temperatures at the point located mear the exhaust valve were higher than those of intake valve. The instantaneous and mean temperature at the cylinder head increases proportionally to the increase of the engine speed, while the temperature swing varies inversely. Temperature swings have influence on the maximum heat flux values from gas into head surface. It has been verified that these probes and data acquisition system perform well by the comparison of the trend of instantaneous temperature variation with that of measured combustion chamber pressure variation with respect to crank angle. It is presumed that these probes could be used in the measurement of other parts of combustion chamber as piston, cylinder wall etc. for the future study.

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3차원 유동해석을 통한 차량 배기소음 예측에 관한 연구 (Prediction of Vehicle Exhaust Noise using 3-Dimensional CFD Analysis)

  • 진봉용;이상호;조남효
    • 한국자동차공학회논문집
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    • 제9권5호
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    • pp.148-156
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    • 2001
  • Computational Fluid Dynamics (CFD) analysis was carried out to investigate exhaust gas flow and acoustic characteristics in the exhaust system of a passenger car. Transient 3-dimensional flow field in the front and rear mufflers was simulated by CFD and far-field sound pressure was modeled by a simple monopole source method. Engine performance simulation was also performed to obtain the boundary condition of instantaneous fluid flow variation at the inlet of the exhaust system. Detailed exhaust gas flow characteristics such as velocity and pressure distribution inside the mufflers were presented and the pulsating pressure amplitude was compared at several positions in the exhaust system to deduce sound pressure level. The present method of the acoustic analysis coupled with CFD techniques would be very effective for the prediction of sound noise from vehicle exhaust systems although the effects of the inlet boundary condition and heat transfer on the accuracy of the prediction have to be validated through further studies.

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Measurement of suction air amount at reciprocating engine under stationary and transient operation

  • Kubota, Yuzuru;Hayashi, Shigenobu;Kajitani, Shuichi;Sawa, Norihiro
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.1037-1042
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    • 1990
  • The air-fuel ratio of an internal combustion engine must be controlled with accuracy for the improvements of exhaust emission and fuel consumption. Therefore, it is necessary to measure the exact instantaneous amounts of fuel and suction air, so we carried out the experiments for measuring the air flow velocity in a suction pipe of an internal combustion engine using three types of instantaneous air flowmeter. The results obtained can be summarized as follows: (1) The laminar-flow type flowmeter is able to measure both the average and the instantaneous flow rate, but it is necessary to rectify the pulsating air flow in the suction pipe. (2) The a spark-discharge type flow velocity meter is able to measure the instantaneous air velocity, but it is necessary to choose the suitable electrode form and the spark character. (3) The tandem-type hot-wire flow velocity meter indicates the instantaneous flow velocity and its flow direction.

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순간 가스온수기의 CO 중독사고 예방에 관한 연구 (A Method to Prevent CO Poisoning from Instantaneous Water Heaters)

  • 안정진;여창훈;조영도
    • 한국가스학회지
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    • 제15권3호
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    • pp.26-30
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    • 2011
  • 개방형 순간 가스온수기는 설치와 관리가 적절히 되지 않아 일산화탄소 중독과 질식과 같은 인명사고를 발생시킬 수 있다. 연소기에 공기가 충분히 공급되지 않거나 배기구가 막히면 배기가스 중의 일산화탄소(CO)의 농도가 증가하는 특성을 보인다. 본 연구는 가정집에서 사용 중인 개방형 가스온수기를 회수하여 연소기 주변 공기 중산소농도 및 배기가스 중 CO농도의 변화를 확인하였다. 환기구 면적에 따른 산소농도 측정 실험에서 환기구의 면적이 바닥면적의 3.5%에서 산소농도가 약 17.7%로 나타났고, 배기구를 폐쇄한 상태에서 CO농도를 측정한 결과 4,000ppm이상이 측정되었다. 따라서 정기적으로 배기구를 점검하는 것이 환기구 크기보다 일산화탄소 중독사고를 예방하기 위하여 중요하다.

대공간 화재시 배연효율 정의에 관한 수치해석적 연구 (Numerical Study on the Definition of the Exhaust Effectiveness of Smoke under Fire in a Large Space)

  • 김정엽;장경진;한화택
    • 설비공학논문집
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    • 제26권11호
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    • pp.535-540
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    • 2014
  • This paper investigates the exhaust effectiveness of smoke, in the case of fire in a large atrium space. Numerical analysis was conducted to simulate transient fire growth in a test room, modeled by the Murcia atrium fire test. Various indices representing the exhaust performance of the exhaust system were obtained, such as the height of the smoke layer, and the instantaneous and accumulative capture efficiency of the smoke. The residual life time of smoke from the fire was also obtained, by injecting tracer gases at the fire location, depending on the airflow rate, and the location of the exhausts. The capture efficiency based on smoke concentration at the exhausts exhibits how much smoke can be removed by the exhaust system; whereas, the exhaust effectiveness based on residual life time indicates how rapidly the smoke can reach the exhaust locations, before being exhausted. The definitions and meanings of the indices to be used in representing the exhaust performance of a smoke exhaust system installed in a large space are discussed.

엔진 배기단 적용을 위한 Time Resolved Laser Induced Icandescence (TIRE-LII) 신호의 보정 : 카본 입자 이용 (The Calibration Method of Time Resolved Laser Induced Incandescence Using Carbon Black Particles for the Soot Measurement at Exhaust Tail Pipe in Engine)

  • 오광철;김덕진;이천환;이춘범
    • 대한기계학회논문집B
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    • 제29권12호
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    • pp.1335-1343
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    • 2005
  • The calibration technique of Time Resolved Laser Induced Incandescence was investigated both experimentally and numerically by using standard-sized carbon black particles for the instantaneous soot measurement at exhaust tail pipe in engine. The carbon black particles (19nm, 25nm, 45nm and 58nm) used in this study are similar, though not identical, to soot particle generated from flame not only in morphology but also in micro-structure. The amount of soot loading in flow was controled by a diluted gas (nitrogen) and was measured by the gravimetric method at exhaust pipe in calibrator. The successful calibrations of primary particle size and soot mass fraction were carried out at the range from 19nm to 58nm and from $0.25mg/m^3$ to $37mg/m^3$ respectively. And based on these results the numerical simulation of LII signal was tuned and the effect of an exhaust temperature variation on the decay rate of LII signal was corrected.

4사이클 가솔린기관의 배기조성에 관한 연구 -$NO_{\chi}$의 비평형 계산- (Study on Exhaust Gas Composition in the Four Ctcle Gasoline Engind -Nonequilibrium Calculation of $NO_{\chi}$ -)

  • 이성열;오영일
    • 대한기계학회논문집
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    • 제1권4호
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    • pp.171-181
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    • 1977
  • This paper is aiming at calculating NOx concentration, which is one of the harmhul components of emission from the gasoline engine, formed in the combustor through the presess of combustion. Instantaneous temperature and concentration of each components for each division can be determined by the solution of simulatneous equation of reaction equation and equation of energy conservation, inputting the estimated temperature with a considerably wide rage of temperature. After determining instantaneous temperature and instantanous concentration of each components, the nonequilibrium calculation is performed based on the reaction kinetics in order to determine NOx concentration. To summarize the result abtained from the above method ;through the passage of NO concentration, NO concentration is the highest in the first division and it is gradually decreasing through the following divisions In the final division, NO concentation is the lowest.