• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.498-503
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• 2012

It happens that the fuel is not injected when the driver doesn't push the acceleration pedal of vehicle with engine speed higher than 1,500rpm above the mid range of vehicle speed. This is called "fuel-cut function" and almost every modern vehicle is equipped with this function. This is activated frequently on the downhill area of highway and the quantity of vehicle-exhausted $CO_2$ gas can be zero on this area. With this fuel-cut function on the test highway, $CO_2$ gas from passenger car(2,000cc engine volume) can be reduced up to 4%. The fuel-cut function with CRUISE made in company AVL is simulated to find the most effective driving pattern on the downhill area. By simulating with CRUISE software, it is found that the lower limit of vehicle speed for fuel-cut should be raised to improve the fuel economy on the steeper downhill road. The fuel economy can be most economical when fuel-cut driving and reacceleration are completed on the section of downhill road.

• Journal of Digital Convergence
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• v.17 no.11
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• pp.207-213
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• 2019

The fuel-cut coast-down driving mode is activated when the acceleration pedal is released with transmission gear engaged, and it's a default function for electronic-controlled engine of vehicles. The fuel economy becomes better because fuel injection stops during fuel-cut driving mode. A fuel-cut detection method is suggested in the study and it's based on the speed, acceleration and road gradient data from GPS sensor. It detects fuel-cut driving mode by comparing calculated acceleration and realtime acceleration value. The one is estimated with driving resistance in the condition of fuel-cut driving and the other is from GPS sensor. The detection accuracy is about 80% when the method is verified with road driving data. The result is estimated with 9,600 data set of vehicle speed, acceleration, fuel consumption and road gradient from test driving on the road of 12km during 16 minutes, and the road slope is rather high. It's easy to detect fuel-cut without injector signal obtained by connecting wire. The detection error is from the fact that the variation range of speed, acceleration and road gradient data, used for road resistance force, is larger than the value of fuel consumption data.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.36-38
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• 2011

As the increase of the fuel oil price, the demand for saving of the ship running cost is growing. To meet the needs of the shipowners, the method for low load operation has been developed by engine licenser. As one of low load operation, the turbocharger cut-out system can be utilized flexibly both full and part load operation. It can be possible to optimize fuel consumption at both full and part load operation. Tests by engine licenser with 12K98MC engine have proven that the fuel oil consumption can be reduced approximately 5%. In this paper we will study the application of main engine turbocharger cut-out system onboard a vessel. One of four turbochargers with MAN Diesel & Turbo 12K98MC-C and 12K98ME-C engine is cut out with swing gate valve. The fuel oil consumption is measured during sea trial and engine shop test.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.10-13
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• 2008

Fuel cell systems have witnessed remarkable development in recent years as they offer a clean and efficient alternative for power generation. Testing was conducted to determine the safety performance of a residential fuel cell system when subjected to abnormal operation condition, especially for voltage sag and fuel cut. In case of voltage sag to 198V, its arriving time at rated power had shown a slight lag but there wasn't any noticeable change when operating it between rated voltage(220V) and 10% voltage sag(198V). In case of fuel cut, it also showed stable shut-down characteristics. The test results are being used to develop a new safety evaluation for residential fuel cell system.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.327-333
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• 2019

The Fuel-cut driving is started when the acceleration pedal released with transmission gear engaged. Fuel economy of the vehicle improves by active fuel-cut driving. A deep-learning technique is proposed to predict fuel-cut driving with vehicle speed, acceleration and road gradient data in the study. It's 3~10 of hidden layers and 10~20 of variables and is applied to the 9600 data obtained in the test driving of a vehicle in the road of 12km. Its accuracy is about 84.5% with 10 variables, 7 hidden layers and Relu as activation function. Its error is regarded from the fact that the change rate of input data is higher than the rate of fuel consumption data. Therefore the accuracy can be better by the normalizing process of input data. It's unnecessary to get the signal of vehicle injector or OBD, and a deep-learning technique applied to the data to be got easily, like GPS. It can contribute to eco-drive for the computing time small.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.141-144
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• 2006

In this study, we developed a decladding device which separates 250 mm length of simulated nuclear spent fuel rod into the pallets and the pieces of the hulls after inserting the rod cut into the module with several pairs of blades. To improve the performance of the equipment, we considered some mechanisms to prevent the rod cut from being exposed or bounced into the hot-cell, to reduce the operation time, and to insert the rods automatically. It is expected that the newly developed system will contribute to prevent radioactive pollution in the hot-cell, reduce the operation time, and to increase the safety of the operators. As a result of the performance test for some mockup fuel rod cuts in the ACP(Advanced Spent Fuel Control Process) facility, it was verified that the decladding device could be applied to the actual fuel rod cut. And it will be able to use for a scale-up facility in the future.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.86-92
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• 2010

The fuel is not injected when the driver doesn't push acceleration pedal of a vehicle with engine speed higher than about 1,500rpm above mid vehicle speed range. This is called "fuel-cut function" and almost every modern vehicle is equipped with this function. This is activated on downhill part of a highway most often. Therefore the vehicle-exhausted $CO_2$ can be zero in this downhill part if the driver could recognize this part of highway. We compared the vehicle-exhausted $CO_2$ emission when using fuel-cut function with the $CO_2$ mass when without using this function in this study. We found that the $CO_2$ emission reduced with fuel-cut function and measured the reduction rate of vehicle-exhausted $CO_2$ mass with this test results. The exhausted $CO_2$ mass of a passenger car(2,000cc engine volume) is reduced by 4% with this function used. This $CO_2$ reduction effect can be achieved if the downhill part of a highway is painted with a specific color. And this road painting can be included in the highway road rehabilitation policy.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.10a
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• pp.189-190
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• 2017

For the concept design of the device, a tool was made to test the simulated fuel rods and cutting force and the cutting force was measured. When 2-CUT and 3-CUT modules were used, the maximum force in 2-CUT at 12.5 mm/s speed change was $197.5kg_f$ and the maximum force at 3-CUT was $363.2kg_f$. The change of force in 2-CUT rapidly increases from about 1 second, and you can see that there are increase and decrease of the force change from about 5 seconds to 18 seconds, and it was rapidly decreased and the cut was made. The force change in 3-CUT has higher force at about 5 seconds later than 2-CUT at the speed of 12.5 mm/s, and you can see that it has the same tendency afterwards. If you search for the force at adequate speed from this cutting force test, 2-CUT module requires less slitting force than 3-CUT module, and the cutting time for 250 mm at 12.5 mm/s was 21 seconds, which can cut 4 m fuel rod in 5 minutes. But, there are cases of not completely slitting with 2-CUT module, so it is necessary to supplement this in the future through experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.393-396
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• 2000

Spent fuel rod cutting device should cut a spent fuel rod to an optimal size in order to fast decladding operation. In this paper, for developing spent fuel rod cutting device with cutter blade, rod properties such as dimension and material of zircaloy tube and fuel pellet are investigated at first and then, various methods of existing cutting devices used commercially are investigated and their performance are analyzed and compared. This device is designed to be operated automatically via remote control system considering later use in Hot-Cell (radioactive area) and the mdularization in the structure of this device makes maintenance easy. SUS and Zircaloy-4 are selected as cut material used in the test of spent fuel rod cutting device by cutter blade. In order for constructing the high durable cutter blade, various materials are analyzed in terms of quality, shape, characteristic, and heat treatment, etc. and from these results, spent fuel rod cutting device is designed and manufactured based on the considerations of durability, round shape sustainability of rod cross-section, debris generation, and fire risk, etc.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.20-27
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• 2003

In this paper, the fuel transport characteristics during transient condition was studied by using a Fast Response Flame Ionization Detector(FRFID). The quantitative measurement method for the inducted fuel mass into cylinder is studied. The inducted fuel mass into the cylinder was estimated by using calculated air-fuel ratio by hydrocarbon concentration of cylinder and air flow model. In order to estimate the transportation of injected fuel from the intake port into cylinder, the wall wetting fuel model was used. The two coefficient $\alpha$,$\beta$) of the wall-wetting fuel model was determined from the measured fuel mass that was inducted into the cylinder at the first cycle after injection cut-off To reduce an air/fuel ratio fluctuation during rapid throttle opening, the appropriate fuel injection rate was obtain from the wall wetting model with empirical coefficients. Result of air/fuel ratio control, air/fuel excursion was reduced.