CRDI 디젤엔진의 피에조 인젝터 불량에 따른 파형 분석에 관한 실험적 연구

유종식,김철수 한국기계기술학회 2018 한국기계기술학회지 Vol.20 No.6

This paper investigates the relationship of voltage and current waveform between normal piezo injector and deterioration abnormal piezo injector. The experimental methods using Pico oscilloscope and GDS scan tool are employed to measure current and voltage waveform and fuel pressure of piezo injector. The experiment is carried out during no-load condition. A summary of the important results are as follows. 1) In case of normal injector, the fluctuation of duration time of piezo injector was linearly and regularly decreased with increasing engine speed, but the that of deterioration piezo injector was irregularly decreased with increasing engine speed. 2) In main injection, the peak value of the current waveform of abnormal injector was larger than that of normal injector, the duration time of deteriorated abnormal injector was less than that of normal injector at 800rpm and 1500rpm, but the duration time of deteriorated abnormal injector was larger than that of normal injector at 2000rpm and 3000rpm. This irregularity appears to be caused by the deterioration of the injector.

기계식 디젤 인젝터의 노후화가 분무 특성에 미치는 영향

정민욱(Minuk Jeong),유영수(Young Soo Yu),양승호(Seungho Yang),박성욱(Sungwook Park) 한국자동차공학회 2021 한국자동차공학회 부문종합 학술대회 Vol.2021 No.6

최근 국내 노후 농기계의 비중이 증가함에 따라 농기계의 디젤 엔진이 노후화되어 성능 저하와 더불어 배출가스가 다량 배출되는 문제가 있다. 노후화가 심한 농기계의 경우 미세먼지 배출량이 매우 높을 것으로 판단되며, 디젤 엔진에서 인젝터의 분무 특성은 엔진의 성능 및 배기 배출물에 큰 영향을 주는 것으로 알려져 있다. 따라서 노후 농기계의 배출 가스를 줄이기 위한 연구가 필요하다. 노후 농기계의 배출가스 배출량에 영향을 주는 핵심 부품 중 기계식 디젤 인젝터의 노후화가 분무 특성에 미치는 영향을 확인하기위한 연구를 수행하였으며, 연구 대상으로 Perkins社의 Tier 1 농기계 디젤 엔진의 2345L009 노후 인젝터와 신품 인젝터를 대상으로 실험을 진행하였다. 노후화가 진행된 인젝터와 신품 인젝터의 분무 특성 비교를 위해 분사량, 분사율, 분무가시화 실험을 수행하였다. 실험 방법은 연료 압력이 인젝터 니들이 개방되면 분사가 개시되는 기계식 인젝터 특성상 전기 모터로 분사 펌프를 구동하여 분사실험을 진행하였으며, 부품 간 간섭의 영향을 반영하기 위하여 4개의 인젝터를 동시에 구동하고 4개 중 1개의 인젝터에 대하여 분무 실험을 수행하였다. 분사량 실험의 경우 분사속도를 엔진 회전수 기준 600, 1200, 1800 rpm으로 달리하여 실험을 진행하고 연료 밸브를 완전 개방한 상태로 1분동안 측정 용기에 분사하여 질량을 측정하였으며, 실험간 오차를 최소화하기 위해 동일 실험을 3회 반복하여 그 평균을 측정값으로 하였다. 분사율 측정의 경우 Bosch 장관법을 이용하여 측정하였으며, 엔진 회전수 1200 rpm에서 연료 밸브를 완전 개방하여 분사하였다. 또한, 측정장치의 분위기 압력을 10 bar로 하여 인젝터 분사에 의한 100개의 압력파형을 중첩하여 분사율을 측정하였다. 분무 가시화는 Mie-scattering 기법을 적용해 분위기 압력 조절이 가능한 정적 챔버를 이용하여 분무 가시화 실험을 수행하였다. 가시화 실험의 실험조건은 엔진 회전수 1200 rpm에서 연료 밸브를 완전 개방하여 분사하였으며, 계기압력 기준 0 bar, 5 bar, 10 bar, 15 bar으로 분위기압력을 변화시켜가며 분무 이미지를 취득하였다. 취득한 이미지는 MATLAB image processing tool을 이용하여 분무 도달거리와 같은 거시적 분무특성을 분석하였다.

BOSCH 솔레노이드 방식의 Grade 인젝터와 IQA 인젝터 불량이 연료 분사량제어에 미치는 영향에 관한 실험적 연구

강성구,김철수 한국기계기술학회 2018 한국기계기술학회지 Vol.20 No.3

In this paper, 'Pico scope' was used to measure and analyze high voltage waveforms of 'Grade injector' and 'IQA injector' due to defective solenoid injector of CRDI diesel engine, and the following conclusions were obtained. In the case of the injector of 'Grade Injector' and 'IQA Injector', there was no change in the injection timing of the injector while the injector was installed. However, by controlling the operation time, It is judged that the injector control is insufficiently controlled when the number of revolutions of the engine is increased to 2000 rpm and 3000 rpm in the idling state in the idling state because the injector failure is precisely controlled in the idling state, When determining the fault injector, the waveform of the 'Grade injector' and 'IQA injector' can be detected by waveform analysis by comparing the injection control time by measuring the high voltage waveform of the injector control in idle idling state. Can be easily diagnosed and maintained. I hope this study will be handed to the mechanics to make diagnosis of CRDI injector convenient.

포토 센서와 충격 센서를 이용한 디젤 솔레노이드 인젝터 연료 분사 시작 및 종료 타이밍 측정

박성재,이충훈 대한기계학회 2023 大韓機械學會論文集B Vol.47 No.11

디젤 솔레노이드 인젝터를 제어하여 연료를 분사하였을 때, 연료 분사 시작과 종료 타이밍을 광센서 및 충격 센서를 사용하여 측정하였다. 인젝터 노즐팁 최근접 위치에 광센서를 설치하여 분무를 감지하였다. 인젝터 바디 바깥쪽에는 충격 센서를 장착하여 인젝터 내 니들의 움직임을 감지하였다. 광센서와 충격 센서에 의한 연료 분사 시작 타이밍의 정확한 측정이 가능함을 확인하였다. 연료 분사 종료 타이밍은 광센서로는 측정이 가능하였으나 충격 센서로는 불가능하였다. 연료 분사 패턴은 단발 분사와 파일롯 분사 2가지를 사용하였다. 단발 분사로 연료를 분사할 때에는 연료 레일압을 45 MPa, 75 MPa, 105 MPa 3 케이스로 제어하였다. 파일롯 분사의 경우에는 75 MPa로 제어하였다. 측정 데이터의 통계적 처리를 위해서 하나의 실험 조건에서 35회씩 반복 측정하였다. 불확실성 해석에 필요한 에로 분포 함수는 정규 분포를 사용하였다. The start and end timings of a controlled fuel injection in a diesel solenoid injector were measured using photo and shock sensors. The photo sensor was installed near the tip of the injector nozzle to measure the spray. The shock sensor was installed outside the injector body to detect the movement of the injector needle. It was confirmed that the fuel injection start timing could be accurately measured by both the photo and shock sensors, while the fuel injection end timing could be measured only by the photo sensor. Two types of fuel injection patterns, namely single and pilot injections, were investigated. In the single injection, the fuel rail pressure was controlled at values of 45, 75, and 105 MPa. On the other hand, in the pilot injection, the pressure was set to 75 MPa. To aid in the statistical processing, the measurements were repeated 35 times under one experimental condition. For the uncertainty analysis, a normal distribution was assumed for the error distribution function.

디젤 엔진의 인젝터 설계 변수가 노즐 코킹에 미치는 영향 분석

김용래 ( Young Rae Kim ),송한호 ( Han Ho Song ) 한국분무공학회 2012 한국액체미립화학회지 Vol.17 No.3

Recent common-rail injector of a diesel engine needs more smaller nozzle hole to meet the stringent emission regulation, But, small nozzle hole diameter can cause nozzle coking which is occurred due to the deposits of post-combustion products, Nozzle coking has a negative effect on the performance of fuel injector because it obstructs the fuel flow inside a nozzle hole, In this study DFSS (Design for six sigma) method was applied to find the effect of nozzle design parameter on nozzle coking, Total 9 injector samples were chosen and tested at diesel engine, The results show that nozzle hole diameter and K-factor have more effect on nozzle coking than A-mass and hole length. Large hole diameter and A-mass, small hole length and K-factor give more positive performance on nozzle coking in these experimental conditions. But, a performance about nozzle coking and exhaust gas emission shows the opposite tendency. More detail studies are needed to find the connection relation between nozzle coking and emission at the optimization work of injector nozzle development.

CRDI 디젤엔진의 보쉬 제어방식과 델파이 제어방식의 인젝터 전압과 전류파형 비교연구

강성구,김철수 한국기계기술학회 2019 한국기계기술학회지 Vol.21 No.1

In this paper, we investigate the relationship between fuel injection quantity and voltage and current energy of Bosch system and Delphi system by measuring the high and low voltage waveform, current waveform, fuel injection quantity and fuel pressure of A and J- engines. Waveform measurements are made using the PICO scope and the CDS tester. The injectors of A and J engines were tested under no load condition using injector with normal fuel injection quantity, injector with small fuel injection quantity and injector with many fuel injection quantity. In case of normal injector, A-engine has higher fuel pressure, injection interval time , voltage energy, and current energy than J-engine. The current energy of the A-engine changed linearly compared to that of the J-engine. For over and under injectors, the change in the previous physical quantity was greater for the A-engine than for the J-engine. However, the duration time of maintaining to open the injector is controlled differently, and so the voltage and current energy values are changed, and the change of the current energy is larger than the voltage energy.

노후 기계식 인젝터의 분무특성 연구

정민욱 ( Minuk Jeong ),유영수 ( Young Soo Yu ),양승호 ( Seungho Yang ),최민후 ( Minhoo Choi ),박성욱 ( Sungwook Park ) 한국분무공학회 2021 한국액체미립화학회지 Vol.26 No.3

Deteriorated agricultural diesel engines using mechanical fuel injection systems have low fuel injection pressures. And they are not equipped with an exhaust gas abatement device, so it produces a lot of exhaust gas. Remanufactured used injectors can reduce emissions because spray characteristics are improved. In addition, remanufacturing is environmentally friendly and economical compared to producing new parts. For efficient injector remanufacturing, it is necessary to conduct a comparison experiment on the spray characteristics of an used mechanical injector and a new injector of the same model. In this study, the spray characteristics of the two injectors were compared by performing an injection quantity measurement and a spray visualization experiment. As a result, the used injector had a larger injection quantity, a shorter spray tip penetration, a wider spray angle and a smaller spray area than the new injector.

커먼레일 디젤인젝터의 분사성능 개선을 위한 내부유로형상 최적화에 관한 수치적 연구

문성준(Seongjoon Moon),정수진(Soojin Jeong),이상인(Sangin Lee),김태훈(Taehun Kim) 한국자동차공학회 2014 한국 자동차공학회논문집 Vol.22 No.2

The common-rail injectors are the most critical component of the CRDI diesel engines that dominantly affect engine performances through high pressure injection with exact control. Thus, from now on the advanced combustion technologies for common-rail diesel injection engine require high performance fuel injectors. Accordingly, the previous studies on the numerical and experimental analysis of the diesel injector have focused on a optimum geometry to induce proper injection rate. In this study, computational predictions of performance of the diesel injector have been performed to evaluate internal flow characteristics for various needle lift and the spray pattern at the nozzle exit. To our knowledge, three-dimensional computational fluid dynamics (CFD) model of the internal flow passage of an entire injector duct including injection and return routes has never been studied. In this study, major design parameters concerning internal routes in the injector are optimized by using a CFD analysis and Response Surface Method (RSM). The computational prediction of the internal flow characteristics of the common-rail diesel injector was carried out by using STAR-CCM+7.06 code. In this work, computations were carried out under the assumption that the internal flow passage is a steady-state condition at the maximum needle lift. The design parameters are optimized by using the L16 orthogonal array and polynomial regression, local-approximation characteristics of RSM. Meanwhile, the optimum values are confirmed to be valid in 95% confidence and 5% significance level through analysis of variance (ANOVA). In addition, optimal design and prototype design were confirmed by calculating the injection quantities, resulting in the improvement of the injection performance by more than 54%.

바이오 디젤 혼합비에 따른 커먼레일 인젝터 분사특성에 관한 실험 연구

김태범(Taebum Kim),임석연(Seokyeon Im),조성철(Sungchul Cho),유상석(Sangseok Yu) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

An object of this study is to understand the correlation of injection characteristics and injector dimensions according to bio-diesel mixture. The Injection characteristics of different types of common-rail injectors are the number of nozzle holes(5~8), jet cone angle(146°~153°), hydraulic flow rate(830~900㎖/min) injection quantity and response time. Prior to characteristic experiment, the reference injector has been selected in 6 candidates injectors under the investigation of injected quantity according to the bio-diesel mixture so that injector type can be determined. The injector is used for the characteristic experiment which varied the various operating conditions including pressure 23㎫, 80㎫, 160㎫, changing in injection duration 0.16㎳~1.2㎳ and even mixture ratio. The result shows that the nozzle hole number and cone angle influence the injection quantity much more than nozzle hole diameter at low injection pressure and the nozzle hole diameter at high injection pressure, post injection duration.

바이오 디젤 혼합비에 따른 커먼레일 인젝터의 분사 및 내구특성에 관한 실험 연구

임석연 ( Seok Yeon Im ),김태범 ( Tae Bum Kim ),유상석 ( Sang Seok Yu ) 한국분무공학회 2011 한국액체미립화학회지 Vol.16 No.1

An object of this study is to understand the correlation of injection characteristics and injector dimensions according to biodiesel mixture. The Injection characteristics of different types of common-rail injectors are the number of nozzle holes (5~8), jet cone angle (146˚~153˚), hydraulic flow rate (830~900 ml/min) injection quantity and response time. Prior to characteristic experiment, the reference injector has been selected in 6 candidates injectors under the investigation of injected quantity according to the biodiesel mixture so that injector type can be determined. The injector is used for the characteristic experiment which varied the various operating conditions including pressure 23 MPa, 80 MPa, 160MPa, changing in injection duration 0.16 ms~1.2 ms and even mixture ratio. The result shows that the nozzle hole number and cone angle influence the injection quantity much more than nozzle hole diameter at low injection pressure and the nozzle hole diameter at high injection pressure, post injection duration.