• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.331-334
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• 2010

Operating characteristics of DGT-5 being developed by Doosan Heavy Industries & Construction Co., Ltd. for power generation service was evaluated. Starting behavior was improved by a series of tests to investigate the effect of various fuel schedule and several combination of bleed valve control. The engine showed stable operation without any instability of compressor in the full operating regime covering from start-up to load conditions. If there is a rapid change of load in the condition of synchronization to Grid, the engine can be controlled stably based on the analysis of dynamic responses of the engine to an rapid load change and a sudden load rejection.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.6
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• pp.778-784
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• 1999

In this study both the experimental and the analytic approach to find load characteristics on the cam-valve mechanism for matrine diesel engine were demonstrated. The experiment was per-formed with a test rig consisted of real engine components for cam-valve mechanism of overhead valve type. The 9-degree of freedom lumped mass model was developed to simulate cam-valve motion throughly. Behavior of the load acting on the cam-valve mechanism was estimated for the various cam speed. The load variation was getting deeper with the higher cam speed and the jumping of the follower was shown both in the experiment and in the simulation.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.15-17
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• 2007

The variable speed engine generator set is interested for an isolated power system due to reduced fuel consumption and less emission. However, because of sluggish dynamic behavior of the internal combustion engine the power quality would be degraded during the sudden load power surge, where the power required by the load is not available by the engine due to the reduced engine speed. An isolated power system based on variable speed engine with a super-capacitor bank improves dynamic characteristics under sudden load change, and power quality, fuel consumption, and pollutants can be reduced remarkably. Also, it is verified by the computer simulation that the inverter of 3phase-4leg is compatible to the isolated power system with unbalanced load. In this paper, the feasibility of the system has been verified based on a 26kw commercial diesel engine system.

• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.1-6
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• 1977

The dilution of crankcase oil with unburned portions of the fuel during operating is one source of the oil contaminations which will reduce engine life.It has been learned that major causes of oil dilution may be the result of using impure fuels which were mixed with water, dust, and some others, but very little was known about this. This study was conducted to develop a more intimate understanding about oil dilution of the farm kerosene engine while using impure fuel mixed with expecially diesel. Fuels being used in this study were 9 kinds of mixed fuels, kerosene and diesel. Farm kerosenen engine of 10 P.S. was tested at no-load of 1000 and 2000 rpm., such as 1/4, 2/4, 3/4, 4/4, and 11/10 loads for understanding about oil dilution of keresene engine.The result of this study are summarized as follows : 1. The amounts of oil dilution of the engine being tested was increased with increase in the applied loads and the contents of diesel in the mixed fuels when using fuels other than kerosenen and diesel, whereas at $D_100$ fuel the comount of oil dilution decreased in some cases. The lowest value was measured to be 20 cc/hr, at $K_90$ fuel of no-load condition, and the highest value to be 293cc/hr. at $K_{10}$ fuel of 4/4 load condition. 2. When the engine was operated at no-load condition, the amount of oil dilution at 100rpm. was much more than at 2000 rpm. 3. Because the fuel consumption and the oil dilution showed a similar tendency along the applied loads, the excessive fuel consumption of engines was supposed to be one of the important factors affecting oil dilution. 4. The temperature of crankcse oil was varied invesely with oil dilution, but they were not thought to be factors to determine each other variable. 5. The tested engine could be operated with high percentage of diesel mixed fuel from no-load condition to fully loaded condition, but it would be impossible to operate the engine for long hous continuously due to excessive speed fluctuation.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.147-158
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• 1997

This paper presents the analysis technique and procedure of main engine components-cylinder block, cylinder liners, gasket and cylinder head-using the finite element method, which aims to assess mainly the potential of lower oil consumption in a view point of engine design and to decide subsequently the accuracy of engine design which was done. The F.E. model of an engine section consisting of one whole cylinder and two adjacent half cylinders is used, whereby the crankcase is cut off at the block bottom deck. By means of a 3-dimensional F.E. model-including cylinder block, liners, gasket, cylinder head, bolts and valve seat rings as separate parts a linear analysis of deformations and stresses was performed for three different loading conditions;assembly, thermal and gas loads. For the analysis of thermal boundary conditions also the temperature field had to be evaluated in a subsequent step.

• Magazine of the Korean Society of Agricultural Engineers
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• v.18 no.4
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• pp.4259-4264
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• 1976

This paper, is about the test on the operating performance of diesel engine by using of soybean oil which farmers could supply in their farm yard. The diesel engine used is a swirl-chamber type, four stroke cycle with single cylinder, air cooling and its rated horse power is 2 PS per 1300 rpm. Several results obtained are as follows; 1. The starting performance of diesel engine with soybean oil is almost the same as that with light oil. 2. The variation of engine speed according to various engine load is small when soybean oil is used compared with light oil. It is considered that soybean oil is desirable for the purpose of industerial power machine fuel. 3. The specific fuel consumption increases approximately 10 percent high in the condition of rated horse power and maximum horse power and shows less or same during the load test in low velocity, when soybean oil is used 4. Though the brake thermal efficiency in the condition of rated horse power and maximum horse power is inclined to decrease when soybean oil is used compared during the load test in low velocityt shows good inclination.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.93-98
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• 2010

An object of this study is to confirm the opening amount of the throttle valve that is begun the temperature separation of vortex tube for various engine speed and load condition in a common rail diesel engine. The vortex tube located at downstream of the exhaust manifold is a device separating the incoming exhaust gas to hot and cold stream. To find optimum separation efficiency of vortex tube, the opening amount of throttle valve has been investigated for various engine speed and load conditions. Engine speed was found that the influence of engine speed was dominant compared with that of engine load. As engine speed was increased, the throttle opening amount starting temperature separation was reduced.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.822-826
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• 2009

In case of engine room of ship, it uses type 2 ventilation system which supplies outside air forcibly by engine room ventilation fan, and naturally discharges air to outlet through low-pressed casing. The advantage of type 2 ventilation is that it makes inside with bi-pressure status to discharge contaminated materials to outside naturally. However, there is a phenomenon that pressure is greatly different between outside and inside due to huge amount of air supply by engine room ventilation fan. Therefore, we went aboard a container vessel which is on test run to analyze differential pressure with micronanometer by engine load and by combustion air supply method of engine. As a result, as engine load decreases (50, 75, 100%), the differential pressure between outside and inside tends to increase by 35% average, and the difference of pressure was 6.5 times maximum by combustion air supply method of engine.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.617-628
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• 2023

This study aimed to evaluate the engine load factor (LF) of a 90 kW agricultural combine harvester. The combine harvester used in this study is equipped with an electronic engine, and real-time engine data (torque and speed) was collected through a controller area network. The speed of the combine harvester during harvesting operation was divided into three levels (4, 5, and 6 km/h) for the representative operation speed range of 4 to 6 km/h. The LF was calculated using the engine load data measured in real time during harvesting. A weight was applied to the LF for each condition based on a survey of the usage. Results of the field test showed that the LF was 0.53, 0.64, and 0.87 at working speeds of 4, 5, and 6 km/h, respectively. The highest engine load factor was recorded at 6 km/h. Finally, based on the weight for the usage applied, the integrated engine LF was analyzed to be 0.69, which is approximately 144% higher than the currently applied LF of 0.48. A study on LF analysis for the entire work cycle, including idling and driving of the combine harvester, will be addressed in a future study.

• International Journal of Automotive Technology
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• v.8 no.4
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• pp.395-402
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• 2007

Homogeneous Charge Compression Ignition (HCCI) shows great potential for low $NO_x$ emission but is hampered by the problem of no direct method to control the combustion process. Therefore, HCCI combustion becomes unstable easily, especially at lower and higher engine load. This paper presents a method to achieve diesel-fueled HCCI combustion, which involves directly injecting diesel fuel into the cylinder before the piston arrives at top dead center in the exhaust stroke and adjusting the valve overlap duration to trap more high temperature residual gas in the cylinder. The combustion stability of diesel-fueled HCCI combustion and the effects of engine load, speed, and valve overlap on it are the main points of investigation. The results show that: diesel-fueled HCCI combustion has two-stage heat release rate (low temperature and high temperature heat release) and very low $NO_x$ emission, combustion stability of the HCCI engine is worse at lower load because of misfire and at higher load because of knock, the increase in engine speed aids combustion stability at lower load because the heat loss is reduced, and increasing negative valve overlap can increase in-cylinder temperature which aids combustion stability at lower load but harms it at higher load.