Oil Nozzle Research Articles

저열량 바이오매스 합성가스의 혼소특성

Although biomass syngas is very low calorific gas, it is utilized by means of dual fuel combustion technology in the fields of industrial furnace and boiler as a substitute oil technology. The basic structure of duel fuel combustion burner is designed so that low caloric gas fuel is supplied around an oil burner in the middle. In the present study, three types of mixing burners were manufactured to conduct performance experiment. Low caloric gas was evenly distributed around the oil burner and the method of changing the angle of gas nozzle was applied. CO generation decreased according to the increase of the amount of air for combustion. In addition, the shapes and colors of flame changed according to the proportions of gas and oil used. Remained flame after combustion was from the lack of atomization at the exit of oil burner. Although it was difficult to maintain the optimum air ratio due to different required air ratio for oil and syngas, stable combustion was able to maintained within excess oxygen concentration of 4.7~8.2%. From this study, it was shown that the oil atomization at the exit of fuel oil nozzle was promoted by the increased rate of syngas combustion and the CO concentration in flue gas lower than only fuel oil combustion.

The Influence of Nozzle Size and Nozzle Distance on Thickness of Wall-Wetted Oil Film

In order to study the influence of constricting nozzles with different sizes and different distances on the formation of wall-wetted oil film，we measured the thicknesses of wall-wetted oil film under the conditions of different nozzle sizes and different nozzle distances by method of weighing. It is shown in the experiment that the relation between thickness of oil film and nozzle size, nozzle distance is not linear .However, in certain range, the larger the nozzle size, the more effectively the wall-wetted oil film forms and the thicker the thickness of oil film. The further the nozzle distance, the larger the area of the oil film and the thinner the thickness of wall-wetted oil film [1,2].

Time resolved numerical modeling of oil jet cooling of a medium duty diesel engine piston

In medium to heavy duty diesel engines, ever increasing power densities are threatening piston's structural integrity at high engine loads and speeds. This investigation presents the computational results of the heat transfer between piston and an impinging oil jet, typically used to keep the pistons cool. Appropriate boundary conditions are applied and using numerical modeling, heat transfer coefficient (h) at the underside of the piston is predicted. This predicted value of heat transfer coefficient significantly helps in selecting right oil (essentially right oil grade), oil jet velocity, nozzle diameter (essentially nozzle design) and distance of the nozzle from the underside of the piston. It also predicts whether the selected grade of oil will contribute to oil fumes/mist generation. Using numerical simulation (finite element method), transient temperature profiles are evaluated for varying heat flux (simulating varying engine loads) to demonstrate the effect of oil jet cooling. The model, after experimental validation, has been used to understand the transient temperature behavior of the piston and the time taken in achieving steady state. High speed CCD camera is used to investigate the oil jet breakup, localized pool boiling and mist generation due to impinging jet on the piston's underside.

Numerical investigations of piston cooling using oil jet in heavy duty diesel engines

Thermal loading of diesel engine pistons has increased dramatically in recent years owing to applications of various technologies to meet low emission and high power density requirements. Control of piston temperatures by cooling of these pistons has become one of the determining factors in a successful engine design. The pistons are cooled by oil jets fired at the underside from the crankcase. Any excessive piston temperature rise may lead to engine seizure because of piston warping. However, if the temperature at the underside of the piston, where the oil jet strikes the piston, is above the boiling range of the oil being used, it may contribute to the generation of mist. This mist significantly contributes to the non-tailpipe emissions in the form of unburnt hydrocarbons (UBHCs). The problem of non-tailpipe emissions has unfortunately not been looked into so seriously, as the current stress of all automobile manufacturers is to meet the tailpipe emission legislative limits. A numerical model has been developed using finite element methods for studying the oil jet cooling of pistons and has been validated experimentally on a flat plate cooled by oil jet. Using numerical modelling, the heat transfer coefficient (h) at the underside of the piston is predicted. This predicted value of heat transfer coefficient significantly helps in selecting the correct oil type, oil jet velocity, oil jet diameter, and distance of oil nozzle from the underside of the piston. It also helps to predict whether the selected grade of oil will contribute to mist generation. Isotherms of the predicted temperature profiles in a production grade piston have been plotted.

Influence of Spray Painting Parameters on Breathing Zone Particle Size Distributions

Abstract Published sampling data indicate large variability in overspray particle size distributions generated during compressed air spray painting. Several task parameters may influence this variability, including spray nozzle pressure, air-to-liquid mass flow ratio, and worker orientation to the spray booth freestream. This research investigated the importance of these parameters on the resulting breathing zone size distributions. To measure volatile paint mist distributions, droplets were collected on polycarbonate membrane filters treated with a spread retardant and then sized with a light microscope. Size distributions were measured first in a laboratory wind tunnel with a mannequin, flat plate, corn oil, and spray nozzle, and then in an actual paint spray booth. Despite sampling bias due to inlet aspiration efficiency, the results indicate that the worker's position to the freestream strongly influences breathing zone geometric mean diameters. Larger size distributions result when the worker stands ...

97/03479 Atomization of ultra-clean micronized CWS

Much attention is being paid to the Ultra-Clean Micronized Coal Water Slurry (UCMCWS) as a form of coal-based fuel in place of oil in the diesel engine, gas turbine and clean combustion. One of its most important parameters is the size distribution of fuel atomization. In the laboratory three kinds of UCMCWS have been made, with coal containing less than 0.8% ash. The slurry concentration is between 50% and 56% with viscosity less than 600 mPa s. A test rig of atomization with a diesel oil nozzle was used for the slurry. The preliminary conclusion is that UCMCWAS can be atomized equally as well as diesel oil in the working condition of a diesel engine.

Analytical Aspects of Gear Lubrication on the Disengaging Side

Variations and inconsistencies in the ratings of rocket engine lubricating oils on the Ryder Gear Tester prompted an analytical investigation into the mechanism of lubrication. It is considered that gears are lubricated on the disengaging side primarily to rapidly dissipate frictional heat. Based on this consideration, it is contended that oil nozzle position and depth of oil impingement are important variables. It is analytically shown by using the Ryder gears how these important variables could contribute to the load-carrying ability of oils and how these contributions could affect the Ryder ratings of oils. Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in San Francisco, Calif., October 18–20, 1965.