• Journal of Applied Reliability
• /
• v.13 no.1
• /
• pp.11-18
• /
• 2013

For a reliability assessment of machinery parts, accurate performance test, environmental test, life test, etc. are required on the sample. In the performance test conditions of various machinery parts, some problems happen such as needs to rise temperature rapidly with large flow of oil having very low thermal conductivity and to measure very high torque or tiny torque, etc. This study brings out the method to apply heat to rise temperature for large flow of oil without chemical change in a performance test of oil cooler. To measure large scale of torque in a performance test of planetary gearbox of excavator, the method of torque measurement is proposed by replacing the large torque meter priced very expensive. To measure very small torque on lubricated friction, a methode of force balance type test mechanism is introduced for tests of piston assembly.

• Journal of Ocean Engineering and Technology
• /
• v.25 no.3
• /
• pp.90-95
• /
• 2011

On April 20, 2010, a well control event allowed hydrocarbon (oil and gas) to escape from the Macondo well onto Deepwater Horizon (DWH), resulting in an exploration and fire on the rig. While 17 people were injured, 11 others lost their lives. The fire continued for 36 hours until the rig sank. Hydrocarbons continued to flow out from the reservoir through the well bore and blowout preventer (BOP) for 87 days, causing an unprecedented oil spill. Beyond Petroleum (BP) and the US federal government tried various methods to prevent the oil spill and to capture the spilled oil. The corresponding responses were very challenging due to the scale, intensity, and duration of the incident that occurred under extreme conditions in terms of pressure, temperature, and amount of flow. On July 15, a capping stack, which is another BOP on top of the existing BOP, was successfully installed, and the oil spill was stopped. After several tests and subsea responses, the well was permanently sealed by a relief well and a bottom kill on September 19. This paper analyzes the subsea responses and engineering efforts to capture the oil, stop the leaking, and kill the subsea well. During the investigation and analysis of subsea responses, information was collected and data bases were established for future accident prevention and the development of subsea engineering.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.10
• /
• pp.1230-1237
• /
• 2009

The selective plugging strategy of Microbial Enhanced Oil Recovery (MEOR) involves the use of microbes that grow and produce exopolymeric substances, which block the high permeability zones of an oil reservoir, thus allowing the water to flow through the low permeability zones leading to increase in oil recovery. Bacillus licheniformis TT33, a hot water spring isolate, is facultatively anaerobic, halotolerant, and thermotolerant. It produces EPS as well as biosurfactant and has a biofilm-forming ability. The viscosity of its cell-free supernatant is $120\;mPa{\cdot}s$ at $28^{\circ}C$. Its purified EPS contained 26% carbohydrate and 3% protein. Its biosurfactant reduced the surface tension of water from 72 to 34 mN/m. This strain gave $27.7{\pm}3.5%$ oil recovery in a sand pack column. Environmental scanning electron microscopy analysis showed bacterial growth and biofilm formation in the sand pack. Biochemical tests and Amplified Ribosomal DNA Restriction Analysis confirmed that the oil recovery obtained in the sand pack column was due to Bacillus licheniformis TT33.

• Advances in nano research
• /
• v.2 no.2
• /
• pp.99-109
• /
• 2014

Experiments are performed to investigate the single-phase flow heat transfer augmentation of MWCNT/HT-B Oil in both smooth and micro-fin helical tubes with constant wall temperature. The tests in laminar regime were carried out in helical tubes with three curvature ratios of 2R/d=22.1, 26.3 and 30.4. Flow Reynolds number varied from 170 to 1800 resulting in laminar flow regime. The effect of some parameters such as the nanoparticles concentration, the dimensionless curvature radius (2R/d) and the Reynolds number on heat transfer was investigated for the laminar flow regime. The weight fraction of nanoparticles in base fluid was less than 0.4%. Within the applied range of Reynolds number, results indicated that for smooth helical tube the addition of nanoparticles to the base fluid enhanced heat transfer remarkably. However, compared to the smooth helical tube, the average heat transfer augmentation ratio for finned tube was small and about 17%. Also, by increasing the weight fraction of nanoparticles in micro-fin helical tubes, no substantial changes were observed in the rate of heat transfer enhancement.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.1
• /
• pp.83-90
• /
• 2020

Plate heat exchangers(PHE) have been commercialized since the 1920s. Since then, although the basic concept of PHEs has changed little, its design and construction have progressed significantly to accommodate higher temperatures, higher pressures, and large heat exchanging capacities. The development trend of PHEs is consistent with heat plate developments with better thermal efficiency, lower pressure drop, and good flow distribution. The purpose of this paper is to introduce the main development processes of a plate cooler for medium-speed engine lubricant oil cooling in vessels which is in line with the development trend of PHEs and to provide its thermal performance data that were found out during experimental tests. The plate cooler in this study cannot measure the wall temperatures directly due to its structural characteristics, so the heat transfer coefficients were calculated using the modified Wilson Plot method. The water-to-water tests were first conducted experimentally to figure out the characteristics of heat transfer coefficients and pressure drops on the water side and then the water-to-oil tests followed to obtain the heat transfer coefficients on the oil side. The test results showed that heat transfer coefficients and pressure drops on both water and oil side increased with flow rates, and it was also found that all the development targets of the plate cooler in this study were achieved successfully.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.19 no.10
• /
• pp.718-725
• /
• 2007

In the general vapor-compression refrigeration system, refrigeration lubricant circulates in refrigeration system with refrigerant. Knowledge of the amount of circulating lubricant is very important to exactly calculate capacity of the refrigeration system. An experimental study was conducted to estimate the oil concentration of a flowing $CO_2/Oil$ mixtures. POE and PAG oil are considered as test lubricants in this study. Performance tests were conducted under simulated liquid conditions for $CO_2/POE$ oil mixture in oil concentration of 0 to 10 weight-percent and $CO_2/PAG$ oil mixture in oil concentration of 0 to 6 weight-percent in the temperature ranges of $-5^{\circ}C\;to\;15^{\circ}C$. The results obtained indicate specific gravity of $CO_2/Oil$ mixture is increased as oil concentration is increased and as temperature of mixture is decreased. Oil concentration correlation of $CO_2/POE$ oil mixture and $CO_2/PAG$ oil mixture is suggested, based on the measurement of specific gravity and temperature. This correlation enable to predict the oil concentration without extraction of the mixture and can be applied for $CO_2/POE$ mixtures and $CO_2/PAG$ mixtures.

• Journal of Pharmaceutical Investigation
• /
• v.30 no.4
• /
• pp.259-266
• /
• 2000

Vitamin A palmitate, an oily drug which has low chemical stability and is poorly absorbed in the intestine, was formulated into a novel powdered dosage form. This is designated as a redispersible dry emulsion by freeze-drying technique. Before preparing a dry emulsion, vitamin A palmitate oil in solid in water (O/S/W) emulsion with soybean oil and coconut oil using Aerosil 200 as an emulsion stabilizer and polyoxyethylene-polyoxypropylene-blockcopolymer (Pluronic F68) as a surfactant was prepared. The resultants of the stability tests indicated that vitamin A palmitate O/S/W emulsion was improved on increasing the oil content of the formulation. The resultant dry emulsion particles have a good stabilities and free flow properties and readily released the oily droplets to form stable emulsions on rehydration. The drug releasing property from the resultant dry emulsion particles was dependent on factors such as amount of oily carrier(soybean oil) and surfactant(Pluronic F68) formulated. Above 80% of vitamin A palmitate content was released from the dry emulsion for 1 hour. It was deduced that vitamin A palmitate dry emulsion was definitely suitable for oral administration, since small droplets of vitamine A palmitate from the dry emulsion may alter the drug absorption profile resulting in bioavailability enhancement.

• Journal of ILASS-Korea
• /
• v.25 no.4
• /
• pp.162-169
• /
• 2020

The worldwide focus on reducing the emissions, fuel and lubricant consumption in T-GDI engines is leading engineers to consider the crankcase ventilation and oil mist separation system as an important means of control. In today's passenger cars, the oil mist separation systems mainly use the inertia effect (e.g. labyrinth, cyclone etc.). Therefore, this study has investigated high efficiency cylinder head-integrated oil-mist separator by using a compact multi-impactor type oil mist separator system to ensure adequate oil mist separation performance. For this purpose, engine dynamometer testing with oil particle efficiency measurement equipment and 3D two-phase flow simulation have been performed for various engine operating conditions. Tests with an actual engine on a dynamometer showed oil aerosol particle size distributions varied depending on operating conditions. For instance, high rpm and load increases bot only blow-by gases but the amount of small size oil droplets. Submicron-sized particles (less than 0.5 ㎛) were also observed. It is also found that the impactor type separator is able to separate nearly no droplets of diameter lower than 3 ㎛. CFD results showed that the complex aerodynamics processes that lead to strong impingement and break-up can strip out large droplets and generate more small size droplets.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.2
• /
• pp.87-94
• /
• 2007

It has been argued that the use of plastics can cause problems during design and manufacture owing to their low strength, relatively poor thermal conductivity and large thermal expansion. However, the advantages of plastics e.g., corrosion resistance, low cost, curtailment of weight, design flexibility etc., can compensate abundantly for the disadvantages. This study analyzes and compares the heat transfer performance characteristics of automotive compact oil cooler composed of plastic tube bundle with conventional metal oil cooler on the same core area basis as diameter, tube thickness, number of tube or tube arrangement varies. The performance analyses are accomplished by use of computational fluid dynamics program Fluent 6.2, which is verified and compared with the results of performance tests. The result of analyses is coincided with that of experiments. Flow pattern at air side according to tube arrangement is dominant factor which affects heat dissipation in case of similar total heat transfer surface area.

• Particle and aerosol research
• /
• v.13 no.3
• /
• pp.119-125
• /
• 2017

A novel two stage cylindrical cyclone was developed for a 3 phase separator in shale oil production industry. The cyclone performance was compared with a cone type cyclone and multi cyclone at the same experimental condition using water and oil mists generated by a humidifier and atomizer at the flow rate 1 to $2m^3/min$. The removal efficiency of total suspended water droplets by the novel cyclone, calculated using inlet and outlet concentrations measured by an optical particle counter, was 99% which is higher than 90% of oil droplet removal efficiency at $2m^3/min$. It might be due to the evaporation of small water droplets during the tests. The water and oil droplet removal performance of the novel cyclone based on the quality factor which is a function of pressure drop and removal efficiency was the highest among three cyclones. The results indicate that the cyclone could be an economical device to remove water and oil mists from shale gas generation processes where a huge three phase separator is commonly used.