• 한국가스학회지
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• 제22권5호
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• pp.18-23
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• 2018

본 연구에서는 CNG자동차 인젝터의 외부 환경온도에 따른 인젝터의 분사량을 분석하고자 한다. 특히 냉간 시동시와 같은 조건에서 분사량의 변화를 측정하여 저온환경이 가스인젝터 성능에 미치는 영향을 파악하고자 하며, 가스 인젝터 내부의 스프링 특성을 다르게 하여 실험을 진행 하였다. 실험 장치는 연료 공급부, 유량 측정부, 온도 챔버와 인젝터 제어부로 구성하였다. 실험결과를 통해 저온환경일수록 가스인젝터의 초기 분사량이 증가하였으며, 스프링길이 증가에 따른 니들의 열리는 시간(무효분사시간)이 지연됨을 확인하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.207-210
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• 2006

액체로켓엔진을 설계할 때 가장 중요한 부품중의 하나가 인젝터이며, 이를 어떻게 배치하느냐에 따라 엔진의 성능이 크게 달라진다 본 연구에서는 swirl형 인젝터를 적용한 UDMH와 액체산소를 추진제로 사용하는 추력 170톤급 액체로켓 엔진의 인젝터 헤드를 1차 설계할 때, swirl 인젝터의 유량 분포 특성을 수식화한 식으로부터 단위면적당 유량 분포 관계를 계산하였다. 또한 연소실 중앙과 막냉각이 있는 벽면에 이 관계식을 적용함으로써, 연소실 원주방향의 연소특성을 예측하였다.

• 한국자동차공학회논문집
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• 제25권3호
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• pp.389-396
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• 2017

Restorations of automotive parts have been done ever since the first vehicle was produced. Because the most expensive parts of a vehicle are in the engine system, there have been various restoration methods developed for engine parts. In the case of commercial diesel engines, the fuel injection device is a key and expensive component. It also has a significant effect on vehicle performance. In particular, reduced engine power and increased exhaust gas emissions may result from mechanical damage due to abrasion of the spill valve in the fuel injection system of a diesel engine. In this paper, restoration techniques for damaged parts are applied to restore the abrasion of a spill valve of fuel injection, also called as the "unit injector", of commercial diesel engines. In order to recover the damage, optimized polishing techniques using hard-metal and coating processes are applied. To evaluate restoration techniques for the spill valve, performance and durability tests are performed on a test bench.

• 한국자동차공학회논문집
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• 제21권5호
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• pp.169-175
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• 2013

CRDi technology of diesel engine was developed from in the early 2000s due to a need to increase fuel efficiency and environment care. Especially, high-pressure fuel injection system in CRDi system which has a fuel injection unit including an injector, a fuel pump and common-rail, etc. becomes possible to make the exhaust gas clean as well as power improvement. In this study, comparison of dynamic characteristics of servo-hydraulic piezo-driven injector with 3-way and bypass-circuit type was analyzed by using the AMESim code. As results of this study, it found the bypass-circuit inside servo-hydraulic piezo injector can cause a faster injection response than that of the 3-way type. Also it was shown that bypass-circuit type had better control capability due to hydraulic bypass system.

• Journal of Mechanical Science and Technology
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• 제17권12호
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• pp.2087-2098
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• 2003

The development of numerical mathematical model to calculate both the static and dynamic characteristics of a multi-shaft gas turbine consisting of a single combustion chamber, including advanced cycle components such as intercooler and regenerator is presented in this paper. The numerical mathematical model is based on the simplified assumptions that quasi-static characteristic of turbo-machine and injector is used, total pressure loss and heat transfer relation for static calculation neglecting fuel transport time delay can be employed. The supercharger power has a cubical relation to its rotating velocity. The accuracy of each calculation is confirmed by monitoring mass and energy balances with comparative calculations for different time steps of integration. The features of the studied gas turbine scheme are the starting device with compressed air volumes and injector's supercharging the air directly ahead of the combustion chamber.

• 한국분무공학회지
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• 제25권4호
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• pp.154-161
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• 2020

A single spray plume is the basic unit of the entire spray plume and is an important factor in understanding the spray characteristics. However, since the multi-hole GDI injector has a narrow spray angle, the superposition of the spray plumes occurs severely. Therefore, the spray uniformity and the spray atomization characteristics of a single spray plume were analyzed in this study using a single-hole GDI injector. Five single-hole GDI injectors with different nozzle hole diameters were used in the experiment. The uniformity of the spray was evaluated through the analysis of the spray pattern images. In addition, the atomization characteristics were compared using the diameter distribution of the spray droplets obtained using PDPA. As a result, the larger diameter of the nozzle hole, the less uniformity of the spray, and the injection pressure did not have a significant effect on the spray uniformity. It is judged that the surface roughness of the injector has a greater effect on spray uniformity than the diameter of the nozzle hole. Also, the size of the spray droplets increased sharply when the diameter of the nozzle hole was 230 ㎛.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.43-51
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• 1998

Most of fuel-injection system operated with mechanical methods are difficult to control the injection quantity and injection timing as well as injection rate exactly. Moreover high pressure injection scheme is never be realized with conventional one. On the other hand, serious air pollution can be lessened with injection system equipped with those functions. Therefore, electronically controlled Unit Injuctor(UI) appeared to satify above mentioned desires. However, it is still difficult that the most important part, especially solenoid valve, is analyzed precisely, because of the existence of complex combination of electromagnetics, electrics and dynamic problems. In this study, experimental and theoretical analysis are accomplished for understanding of solenoid valve characteristics and further its design. As the result, the follows are obtained 1) As the increase of wire diameter, the response time became shorter and optimal inductance existed in relative with the response time and wire diameter. 2) According to increasing input voltage, the traction force increased, otherwise the response time was shortened. 3) As the increase of armature stroke, the traction force decreased and the response time became longer.

• Journal of Mechanical Science and Technology
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• 제17권1호
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• pp.146-156
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• 2003

A numerical algorithm is developed to analyze the performance of a Unit-injector (UI) System for a diesel engine. The fundamental theory of the algorithm is based on the continuity equation of fluid dynamics. The loss factors that should be seriously regarded on the continuity equation are the compressibility effect of liquid fuel, the wall friction loss in high-pressure fuel lines of the system, the kinetic energy loss of fuel in the system, and the leakage of fuel out of the control volume. For an evaluation of the developed simulation algorithm, the calculation results are compared with the experimental outputs provided by the Technical Research Center of Doowon Precision Industry Co. (DPICO) ； the maximum pressure in the plunger chamber (P$\_$p/) and total amount of fuel injected into a cylinder per cycle (Q$\_$f/) at each operational condition. The result shows that the average error rate (%) of P$\_$p/ and Q$\_$f/ are 2.90% and 4.87%, respectively, in the specified operational conditions. Hence, it can be concluded that the analytical simulation algorithm developed in this study can be reasonably applied to the performance prediction of newly designed UI system.

• 청정기술
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• 제30권2호
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• pp.94-104
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• 2024

재제조는 사용 후 제품을 분해, 세척, 검사, 보수, 조정, 재조립하여 원래의 성능 또는 그 이상의 성능을 가진 제품으로 재상품화하는 것으로, 재제조산업은 2050 탄소중립을 실현하기 위해 필요한 핵심 산업이다. 본 연구에서는 자동차부품 중 재제조가 활발히 이루어지고 있는 인젝터를 대상으로 전과정평가를 이용하여 회피효과를 고려 시와 미고려 시 자원 저감 및 온실가스 저감 효과를 분석하고자 한다. 연구결과, 인젝터 재제조로 인한 자원 저감 효과와 온실가스 저감 효과는 회피효과를 미고려 시 1개 기준으로 95.30%, 93.88%가 저감되는 것으로 나타났다. 재제조 시 제품을 재사용함으로써 사용 후 제품이 폐기되지 않는 환경영향과 천연자원을 사용하지 않는 환경영향의 회피효과를 고려할 시 190.91%, 188.33%가 저감되는 것으로 나타났다. 본 연구결과는 향후 재제조 시 회피효과를 고려한 환경영향 저감량을 평가하고, 연구방법론 개발 시 활용할 수 있을 것으로 본다.

• 한국응용과학기술학회지
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• 제31권4호
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• pp.688-693
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• 2014

본 연구는 생활주변에서 오존수를 쉽게 활용할 수 있도록 오존수 발생장치의 활용성을 증가시키고 한 동작으로 작동하는 시스템을 개발하고자 한다. 더 나아가 올리브 오일과 오존과 반응시켜 제조하는 기술에 적용하고자 한다. 기존의 경우 대부분이 오존수 시스템이 아닌 오존발생기 위주의 제품이 많다. 오존수기의 경우 펌프로 강제 흡입시키는 일반압력 방식으로 오존가스 누출 위험요소가 내포 되어 있으나, 본 과제의 경우 인젝터를 이용하여 물의 유입여부에 따른 오존의 발생과 흡입을 제한하고 있어 기존 제품의 오존 누출에 의한 위험을 최소화하였다. 인젝터 방식의 단점에도 불구하고 미생물 살균능을 유지하는 것으로 본 연구에서 사용된 인젝터 방식 오존수 제조 장치의 효용성을 알 수 있었다.