• Magazine of the Korean Society of Agricultural Engineers
• /
• v.43 no.4
• /
• pp.113-119
• /
• 2001

Ammonia emissions during composting of hog manure mixed with sawdust were studied in four runs comprising a total of 22 pilot-scale reactor vessels. These four runs extended previous work and both verified and extended the previous conclusions. The pilot-scale vessels were 205 L insulated stainless steel drums that were aerated either continuously (high/low thermostatically controlled fans) or intermittently (5 min high fan 55 min off). Temperature ammonia emissions air flow rates carbon dioxide production and oxygen utilization moisture and dry matter reduction initial and final chemical compositions were measured. Ammonia emissions from the intermittently aerated vessels were only about 50% as great as those from the continuously aerated ones but this was found to be a result more related to total air flow than to aeration technique. All of the data for total result more related to total air flow were fitted with a linear regression line y=0.139x+29.835 where y is ammonia expressed as g of N and x is air flow in kg with $R^2$=0.6808. this general trend indicates that about 50% reduction in ammonia emissions can be achieved with 75% reduction in air flow. For the aeration techniques used the minimum oxygen level in te exhaust gas from the vessels was 5% and this is probably a resonable lower limit constraining air flow reduction. However within this constraint lower air flow now appears to be a technique that can reduce odorous ammonia emissions.

• Journal of Biosystems Engineering
• /
• v.12 no.3
• /
• pp.7-16
• /
• 1987

This study was carried out to develop a microcomputer-based data acquisition and control system which was able to collect the data of engine performance test automatically and control the speed and load of the engine. The results of the study are summarized as follows: 1. The signal processing devices, which were able to measure cylinder pressure, coolant temperature, compositions of exhaust gas, fuel consumption, engine rpm and torque etc., were developed. The results of calibration showed that all of devices had high accuracy ranging from 0.3% to 0.69% respectively. 2. The PIA (peripheral interface adapter) for interfacing digital signal and PTM (programmable timer module) for displaying real time every 0.0408 sec were designed and developed. 3. An engine-speed control system using a stepping motor and driver was developed. The control system had the stability, and faster settling time than the manual control system. 4. The automatic control system of electrical dynamometer, which was able to control the speed and load of dynamometer, was developed with a SSD (shackleton system driver) and D/A converter. 5. The computer programs, which were able to collect and process the data of engine tests, were developed using both the machine language and BASIC.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.19 no.6
• /
• pp.10-16
• /
• 2011

Diesel particulate filter is being recognized that it is the most effective technologies to reduce particulate matter. In this study, to determine the characteristics of the cell-open-type pDPF, we employed p-DPF to exhaust gas tunnel of diesel engine and surveyed filtration efficiency and BPT on the basis of PM which is exhausted from engine. In this paper the soot loading mass in DPF can be predicted from increase of differential pressure of DPF so that we can measure filtration efficiency and Balance Point Temperature (BPT) by soot loading mass. The result of the research showed that the filtration efficiency is 65% in ESC mode with 0.7mm hole diameter. For the results of the characteristics of filtration efficiency and BPT according to mass_exh, we found that if mass_exh increases, filtration efficiency increases and BPT decreases.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.6
• /
• pp.168-175
• /
• 2008

In-use light duty diesel vehicles are considered as one of major sources of particulate emissions in many cities, and the start of the retrofit program for the light duty diesel vehicles is expected in near future in Korea. One of the problems of the retrofit of the light duty diesel vehicles is that the exhaust gas temperature is too low to apply passive regeneration DPF systems. This study introduces a catalytic combustor as a new active DPF regeneration technology. This study shows the principle and characteristics of DPF regeneration by the catalytic combustor and suggests it's proper control method for better regeneration.

• Journal of Energy Engineering
• /
• v.29 no.1
• /
• pp.58-62
• /
• 2020

Among the exhaust gas, Carbon dioxide which is a causative factor in greenhouse effect. We study for synthesis of propylene carbonate with carbon dioxide which is captured and utilized in commercially valuable. The Experiment was proceeded as pilot scale with using homogeneous organic catalyst which is able to produce propylene carbonate in commercial and reaction conditions. Optimization condition for concentration of catalyst and reaction temperature, pressure was studied. We confirm that this process is eco-friendly method and commercial application due to the mild condition and also catalyst has a competitive price, reusability.

• Journal of the Korean Society of Combustion
• /
• v.14 no.4
• /
• pp.25-32
• /
• 2009

In commercial combustion systems, heavy oil is one of main hydrocarbon fuel because of its economical efficiency. Regarding heavy oil combustion, due to increasing concerns over environmental pollutants such as carbon monoxide, unburned hydrocarbon and nitrogen oxides, development of low pollutant emission methods has become an imminent issue for practical application to numerous combustion devices. Also a great amount of effort has been tried to developed effective methods for practical using of biomass. It is also an important issue to reduce carbon tax. In this paper, an experimental study has been conducted to evaluate the effect of biomass reburning on NOx formation in a heavy oil flamed combustion furnace. Experiments were performed in flames stabilized by a multi-staged burner, which was mounted at the front of the furnace. Experimental tests were conducted using air-carried rice husk powder and LNG as the reburn fuel and heavy oil as the main fuel. The paper reports data on flue gas emissions and temperature distribution in the furnace for several kinds of experimental conditions. NOx concentration in the exhaust has decreased considerably due to effect of reburning. The maximum NOx reduction rate was 62% when the rice husk was used by reburn fuel, however it was 59% when the LNG was used by reburn fuel. The result shows the positive possibility of biomass reburning system for optimal NOx reduction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.499-505
• /
• 2004

A Propulsion System of the CRW(Canard Rotor Wing) type UAV(Unmanned Aerial Vehicle) was composed of the turbojet engine to generate the propulsive exhaust gas, and the duct system including straight bent ducts, tip-jet nozzles, a master valve and a variable main nozzle for three flight modes such as lift/landing mode, low speed transition flight mode and high speed forward flight mode. In this study, in order to operate safely the propulsion system, the dynamic Performance behavior of the system was modeled and simulated using the SIMULIN $K^{ }$, which is the user-friendly GUI type dynamic analysis tool provided by MATLA $B^{ }$. In the transient performance model, the inter-component volume model was used. The performance analysis using the developed models was performed at various flight condition, valve angle positions and fuel flow schedules, and these results could set the safe flight mode transition region to satisfy the inlet temperature overshoot limitation as well as the compressor surge margin. Performance analysis results using the SIMULIN $K^{ }$ performance program were compared with them using the commercial program GSP.m GSP.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.23 no.6
• /
• pp.608-614
• /
• 2015

Nitrogen oxide(NOx) emission reductions are required to meet the strict emission regulations for environmental protection. Most of the Exhaust Gas Recirculation(EGR) system applied to a diesel engine can relatively decrease the NOx at a low cost, but it has a disadvantage in that the PM generation is promoted due to the hot intake air temperature. Thus, high heat exchange efficiency of the EGR cooler is required for an effective removal of NOx. In this study, heat exchange efficiency for various types of heat exchangers used in EGR cooler was measured under same conditions, and determined best heat exchange performance shape depending on type of heat exchanger.

• International Journal of Automotive Technology
• /
• v.8 no.2
• /
• pp.165-177
• /
• 2007

Predictions of diesel particulate filtration are typically made by modeling of a particle collection, and providing particle trapping levels in terms of a pressure drop. In the present study, a series of single channel diesel particulate filter (DPF) experiments are conducted, the pressure traces are inversely analyzed and essential filtration parameters are deducted for model closure. A DPF filtration model is formulated with a non-linear description of soot cake regression. Dependence of soot cake porosity, packing density, permeability, and soot density in filter walls on convective-diffusive particle transportation is examined. Sensitivity analysis was conducted on model parameters, relevant to the mode of transition. Soot cake porosity and soot packing density show low degrees of dispersion with respect to the Peclet number and have asymptotes at 0.97 and $70\;kg/m^3$, respectively, at high Peclet number. Soot density in the filter wall, which is inversely proportional to filter wall Peclet number, controls the filtration mode transition but exerts no influence on termination pressure drop. The percolation constant greatly alters the extent of pressure drop, but is insensitive to volumetric flow rate or temperature of exhaust gas at fixed operation mode.

• Journal of Internet of Things and Convergence
• /
• v.7 no.3
• /
• pp.75-80
• /
• 2021

Since the optimization of the diesel engine for the ship cannot satisfy the NOx emission limit by the method of reducing the NOx emission, it is necessary to reduce the NOx by post-processing the exhaust gas. In this study, we will review the feasibility of designing a binary nozzle and mixing chamber duct for effectively converting the number of elements into NH3 in the oil burner for the SCR catalyst unit integrated duct in the ship under development through the computational heat flow analysis for the velocity distribution and temperature distribution.