※一部利用できない機能があります
| 1.
論文 |
論文
|
森田, 真一 ; 渡辺, 直樹 ; 古畑, 朋彦 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Six-stroke diesel engine proposed here has six processes in one cycle, i.e. intake, 1st compression, 1st combustion, 2nd compression, 2nd combustion and exhaust. By the direct EGR in the 2nd
…
combustion process, NO emission could be expected to decrease. However, much Soot was exhausted by a weak mixing in the 2nd combustion process. A high pressure injection with a common rail was introduced into the engine to improve the mixing in the second combustion process. As a result, more NO was exhausted while Soot was decreased due to better mixing. In this study, to decrease NO and Soot simultaneously, two stage fuel injection was applied to the 1st combustion. When the main injection timing for the 1st combustion process was extremely delayed, NO and Soot were decreased. It was considered that NO reduction was due to the 1st combustion of low temperature and EGR effect in the 2nd combustion. Also, Soot reduction was due to a relatively long ignition delay for the 2nd combustion
続きを見る
|
||
| 2.
論文 |
論文
|
山本, 知恵美 ; 内野, 寿一 ; 古畑, 朋彦 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Nanometer size particulate matter (Nano-PM) emitted from diesel engine has been received many anxieties due to its harmful potential for health. The objective of this study is to develop a
…
standard Nano-PM generator using liquid fuels, and to investigate the relationship between the characteristics of PM and operation parameters of the generator. A fundamental pool flame of diesel fuel was used for generation of Nano-PM. Scanning Mobility Particle Sizer (SMPS3034) was used to measure the size distribution of PM, and the components of PM were analyzed using a combustion type exhaust gas analyzer (MEXA-1370PM). Thermal diluter was used to investigate the heating effect on size distribution of PM. Main parameters of the PM generator were height and pattern of diffusion flame. Two types of diffusion flame were formed on a fuel pool. One is a small flame where the flame tip was closed and no visible soot was observed. The other was an open tip flame that emitted visible soot from its tip. As for the size distribution of PM, peak diameter increased gradually with an increase of fuel consumption rate. Main component of Nano-PM exhausted from a closed flame was SOF, however dry soot was the main component of open flame. Under hot thermal dilution, number of large particles decreased but number of small particles increased.
続きを見る
|
||
| 3.
論文 |
論文
|
橋本, 健 ; 古畑, 朋彦 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Six-stroke diesel engine proposed here has six processes in one cycle, i.e. intaka, 1st compression, 1st combustion, 2nd compression, 2nd combustion and exhaust. By the effect of direct EGR in the
…
2nd combustion process, NO concentration could be expected to decrease. However, by a weak mixing in the 2nd combustion process, much soot was exhausted and NO concentration was hardly decreased compared with the conventional four-stroke diesel engine. To improve the fuel/air mixing at the 2nd combustion process, high pressure injection with common rail system was applied to the engine. As the result, NO concentration was increased owing to the increase of premixed combustion of 1st combustion process, although soot was reduced. Therefore, the 1st injection timing was extremely advanced to control the 1st combustion process. It changed 1st combustion process into HCCI-like combustion, and NO concentration was greatly decreased. Moreover, soot was reduced with no increase of NO concentration in the 2nd combustion process. As the result, trade-off curve of NO and soot was improved compared with the conventional four-stroke diesel engine. But CO concentration was increased.
続きを見る
|
||
| 4.
論文 |
論文
|
佐藤, 桂司 ; 林田, 和宏 ; 宮川, 拓 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Laser induced fluorescence (LIF) method was applied to the measurement of PAHs (Polycyclic Aromatic Hydrocarbons) in a propane diffusion flame. Various PAHs were excited by a KrF excimer laser
…
and a dye-laser pumped by the XeF excimer laser. By measuring the enission spectra of various PAHs vapors, it was found that the peak wavelength in the emission spectrom of LIF shifted to the longer wavelength side with an increase of PAHs carbon numbers. The carbon numbers of PAHs in a diffusion flame was presumed from the data of peak wavelength of emission spectrum. It was confirmed that the carbon numbers of PAHs in the diffusion flame increased as approaching to the flame surface. The maximum carbon number was about 26 at the layer close to the flame surface.
続きを見る
|
||
| 5.
論文 |
論文
|
佐藤, 桂司 ; 林田, 和宏 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />In this paper, separation of laser-induced fluorescence (LIF) due to PAHs and incandescence (LII) due to soot by time-resolved measurement was demonstrated for the propane diffusion flame.
…
Laser-induced fluorescence method for the measurement of polycyclic aromatic hydrocarbons (PAHs) in diffusion flame was developed. A KrF excimer laser was used for excite the PAHs. Strong laser-induced incandescence due to soot was appeared with fluorescence signal due to PAHs. In order to separate the signals into LII and the PAHs-LIF detected from diffusion flame, time-resolved measurement was carried out. A pico-second gate CCD camera with a image intensifier was used taking a time-resolved image. From the two different images, which were taken at different time-delay, PAHs-LIF and LII were obtained. Intensity distributions of PAHs-LIF and LII were measured on the flame axis. Overlap region of the LIF and LII was observed around the onset position of the yellow flame. In this region, LIF intensity decreased and LII intensity increased along the flow direction. It seemed that this region was transition region from the PAHs to soot and was attributed the presence of soot precursor.
続きを見る
|
||
| 6.
論文 |
論文
|
林田, 和宏 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />NO concentration measurement in the burnt gas from the catalytic combustion was carried out by using a laser-induced fluorescence method. A palladium catalyst supported on a cordierite honeycomb
…
was used. The methance/air mixture, which was pre-heated to 530 K, was introduced into the catalyst honeycomb. To excite a NO molecule, an ArF excimer laser was used. Wavelength of the laser right was set at 193.375 nm. The laser sheet was introduced into the downstream of the honeycomb. In the case of a lean mixture, NO was observed after the honeycomb. On the other hand, in the case of a rich mixture, a blue flame at downstream from the honeycomb were observed, and NO was observed at the blue flame. In order to obtain the NO concentration from the NO fluorescence intensity, temperature dependency of the fluorescence intensity was investigated by using NO-N_2 mixture. Axial concentration distributions of NO were derived from the NO fluorescence intensity distributions. Furthermore, change of the NO emission level with equivalence ratio was investigated at the outlet of the honeycomb.
続きを見る
|
||
| 7.
論文 |
論文
|
茂木, 俊夫 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Fundamental characteristics of the catalytic combustion of vaporized kerosene
…
spray were studied experimentally. Palladium catalyst supported on the cordierite honeycomb monolith was used. Inlet temperature was elevated up to 700 K to evaporate the kerosene spray. Premixed gas of air and kerosene vapor was introduced into the catalyst. The catalytic combustion and gas phase reaction after catalyst were observed in this combustion system. The lean limit of the catalytic combustion was not affected by the space velocity and equivalence ratio of the mixture, but it was greatly affected by the inlet temperature. The parabolic shape blue flame that was supported on the catalyst was formed when the supplied mixture was not completely burned in the monolith. To clarify a reaction process in an combustive gas between the monolith and the blue flame, CO, HC(C_1～C_7) and NO were analyzed. When the blue flame was observed after the catalyst, the HC and CO were formed from the unburned composition of fuel and they were burned as the blue flame. The NO emission level of the catalytic combustion was very low compared with the gas phase reaction of lean mixture.
続きを見る
|
||
| 8.
論文 |
論文
|
周, 斌 ; Machacon, H.T.C. ; 志賀, 聖一 ; 譚, 達明 ; 柄澤, 隆夫 ; 小保方, 富夫 ; 中村, 寿雄
概要:
application/pdf<br />Journal Article<br />In this study a neural network prediction method that can be used in predicting engine behavior is proposed. Using data from a series of characteristic experiments, this method eliminates
…
the need for complicated mathematical calculations used in prediction models. To test this method exhaust emissions and engine performance data from intake gas composition variation experiments were taken and compared with the predicted data from this network. The method has been tested and found effective in predicting engine exhaust emissions and engine performance. This technique can be a valuable tool in engine research.
続きを見る
|
||
| 9.
論文 |
論文
|
新居, 利洋 ; 斉藤, 正浩 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />This paper reports the suppression of soot emission from acetylene diffusion flame by applying electric field. The effects of applied voltage, polarity and spacing of electrodes on soot emission
…
were investigated experimentally. The results showed that the shape of flame changed and the soot emission decreased with increasing the applied voltage. The polarity of applied voltage influenced to the shape of flame and the soot emission. When positive voltage was applied to the nozzle electrode, the flame length became short and the width at the flame tip was spread. And, more than 90% of soot emission was suppressed at over 200 kV/m of the intensity of electric field. The surface temperature of flame increased with increasing the applied voltage. Thus, it was considered that the increase of flame surface temperature promoted the soot oxidation. When negative voltage was applied to the nozzle electrode, on the contrary, only the 70% of soot emission was suppressed, because the flame temperature was comparable to that for non-applied voltage.
続きを見る
|
||
| 10.
論文 |
論文
|
岡本, 雄一郎 ; 荻原, 五郎 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />A Six-stroke diesel engine was developed and its performance was evaluated. This engine had second compression and second combustion strokes which were added on the four stroke diesel engine.
…
To control the fuel injection ratio and injection timings for first and second combustion strokes independently, two fuel pumps were attached to the engine. Effect of the fuel allocation ratio between first and second combustion strokes on the engine performance was investigated. Engine performance of the six stroke diesel engine was compared with that of the four stroke diesel engine which was the base engine of the six stroke engine. As a result, NO concentration in the exhaust gas decreased with a delaying of injection timing at second combustion stroke, but the injection timing at first combustion stroke didn't influence NO concentration. NO concentration decreased with an increase of allocation fuel ratio into the second combustion stroke. A trade-off relation between NO and soot concentration was observed against the change of allocation ratio. From the comparison between six and four stroke engine, it was confirmed that the NO concentration of the six stroke engine becomes lower than that of the four stroke engine.
続きを見る
|
