著者

田村 陽介

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.53, no.163, pp.29-35, 2011 (Released:2018-01-26)

参考文献数

11

---

This paper reports research outlines and safety issues from an experimental study conducted recently by Japan Automobile Research Institute on the fire safety, including existing safety measures, of hydrogen fuel cell vehicles (“HFCV”). One of the concerns about the fire safety of vehicles equipped with a compressed hydrogen cylinder is the proper presence and function of a pressure relief device (“PRD”) designed to release hydrogen gas from the cylinder at the detection of a fire. Since bursting energy in a 70-MPa high pressure compressed hydrogen cylinder can reach 2.4 - 4.2kg in TNT equivalent in case of PRD failure, every necessary step must be taken to prevent PRD malfunction. If the PRD of a 35-MPa hydrogen cylinder is activated, an upward flame of as high as 10m is generated for about 1 minute. However, this short-lived flame is not thermally sufficient for adjacent vehicles to catch fire; HFCV on fire are equivalent with CNG and gasoline vehicles on fire in terms of their thermal impact on surroundings. Furthermore, HFCV fire can be extinguished by an spraying of water while dispensing with any special fire fighting measures.

著者

酒井 康行

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.60, no.193, pp.191-198, 2018 (Released:2019-02-15)

参考文献数

23

---

Combustion simulation is a promising tool in many ways such as understanding the mechanism of ignition and extinction, engine design, emission prediction and control, and fuel development. Regarding the chemical kinetics mechanism for the oxidation of hydrocarbon fuels, there are many investigations on the elementary reaction process, and now we have detailed chemical kinetics models which quantitatively predict the ignition timing and laminar flame velocity for the representative components and their mixtures included in the natural gas, gasoline, diesel fuels, kerosene, and jet fuels. When we combine these large chemical kinetics models into fluid dynamic simulations, the computational cost inhibits the practical use. Thus, the need for the reduction of detailed chemical kinetics model is increasing. This article describes the concept of surrogate fuel which mimics the combustion properties of real fuels with few or several representative hydrocarbon components. Then, we see the mechanism reduction method briefly. Finally, we see the construction of simplified model for gasoline surrogate fuel which predicts the autoignition timing and laminar flame velocity under the temperature and pressure related to the internal combustion engines.

著者

永井 厚司 岡部 俊彦 キム ギョンミン 吉橋 照夫 小原 哲郎 大八木 重治

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 = Journal of the Combustion Society of Japan (ISSN:13471864)

巻号頁・発行日

vol.52, no.159, pp.86-93, 2010-02-15

参考文献数

27

---

<p>Pulse detonation engines (PDEs) are expected to be the next-generation engine systems, and are expected to have applications in various fields. One of the fundamental problems faced during the development of PDEs is the deflagration to detonation transition (DDT). In order to realize a PDE, it is essential to shorten a parameter of detonation transition called a detonation induction distance (DID). However, the mechanism underlying the DDT process and methods to shorten DID in narrow channels have not yet been understood. An experimental study on DDT process in a narrow rectangular channel with a height of 1-5 mm and a width of 8 mm was carried out by employing pressure transducers, ionization probes, and sooted plate technique in oxyhydrogen mixtures. The effects of the tube height and equivalence ratio on pressure detonation limits were discussed. Detonation velocity, DDT process, and DID were discussed on the basis of pressure history and soot track record. Overdriven detonation and attenuated detonation were observed in the narrow channel. The DID value measured on the basis of the soot track record in the present study was in the range of the empirical formula obtained by the other researchers.</p>

著者

北野 智朗 黒瀬 良一

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.59, no.187, pp.8-15, 2017 (Released:2018-02-15)

参考文献数

23

---

One of the most important issues in combustion researches is the prediction and suppression of combustion instability, which induces flashback, generates combustion noise and damages combustor. Although a number of studies on combustion instability have been performed, the underlying physics have not been well clarified yet, especially for spray combustion. In this article, authors' recent numerical works on Large-eddy Simulations (LES) of combustion instabilities are introduced. The combustion instabilities of gas and spray combustion in back-step flows are demonstrated in terms of LES, and effects of initial droplet diameter on the combustion instability are investigated for spray combustion. Methane and kerosene are used as fuels for gas and spray combustion, respectively, and two-step global reaction models are used for calculations of the reactions. A dynamic thickened flame model is employed as a turbulent combustion model.

著者

遠藤 琢磨 須佐 秋生

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.55, no.174, pp.317-328, 2013 (Released:2018-01-26)

参考文献数

17

---

Fundamentals of the propagation characteristics of a detonation are reviewed. First, the propagation characteristics of a detonation are discussed from the one-dimensional point of view. In this discussion, the characteristics of a steadily-propagating detonation and how to determine its static parameters are elucidated. Second, the non-planarity and transverse-wave structure of an actual detonation front are discussed. The transverse waves propagating along the leading shock wave of a detonation front and colliding with each other depict a cellular pattern after the passage of the detonation. The importance of the characteristic size of this cellular pattern is emphasized introducing so-called dynamic parameters of detonations. Finally, the stability issue of the transverse-wave structure of a detonation front is touched on. This issue has been drawing the attention of many researchers for more than a decade.

著者

壹岐 典彦 倉田 修

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.58, no.186, pp.215-222, 2016

---

<p>Ammonia is a carbon-free fuel and one of the candidates of hydrogen carrier. R&D of a gas turbine firing ammonia is not new issue but there are not successful results for a long time. AIST carried out demonstration tests with the aim to show the potential of ammonia-fired power plant. 50kW class turbine system firing kerosene is selected as a base model. A standard combustor is replaced by a prototype combustor which enables a bi-fuel supply of kerosene and fuel gas. The gas turbine started firing kerosene and increased its electric power output. After achievement of stable power output, ammonia gas was started to be supplied and its flow rate increased gradually. Over 40kW power output was achieved by firing ammonia gas only and over 40kW power output was also achieved by co-firing methane and ammonia. Ammonia gas supply increases NOx in the exhaust gas dramatically. However NOx removal equipment can reduce NOx successfully. The emission of NO and unburnt ammonia depends on the combustor inlet temperature.</p>

著者

下栗 大右 石塚 悟

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.59, no.187, pp.41-48, 2017 (Released:2018-02-15)

参考文献数

13

---

The radial / tangential modes of acoustically resonant oscillatory combustion have been observed in the large scale tubular flame burners. The triggering and amplification mechanisms of those modes of oscillations can be understood in detail with tubular flame burners because (1) those modes of oscillations have been found to be occurred in tubular flame burners at relatively low thermal input conditions with high reproducibility, and thus, the experiments can be repeatedly conducted under the well-controlled conditions, and (2) the modes of oscillations are easily identified because the natural frequencies of the tubular flame burners are easily obtained due to its simple geometry, and furthermore (3) the heat release position can be easily identified because the tubular flame is the thin laminar flame front. At present, it was found that (n, m) = (0, 1) mode of oscillation which has non-axisymmetric sound pressure profile is the dominant mode of oscillation, where n and m is the radial and tangential mode number, respectively. As results of flow field measurements, the Presessing Vortex Core motion was observed in the burned gas region of the tubular flame burner, which can cause the non-axisymmetric sound pressure structure in the tubular flame burner.

著者

阿部 一幾 小金沢 知己

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.57, no.179, pp.27-35, 2015 (Released:2018-01-26)

参考文献数

20

---

Humid air turbine systems that are regenerative cycle using humidified air can achieve higher thermal efficiency than gas turbine combined cycle (GTCC) power plant even though they do not require steam turbine, high combustion temperature, or high pressure ratio. In particular, the advanced humid air turbine (AHAT) system appears to be highly suitable for practical use because its composition is simpler than that of other systems. Moreover, the difference in thermal efficiency between AHAT and GTCC is greater for small and medium-size gas turbines. To verify the system concept and the cycle performance of the AHAT system, a 3 MW-class pilot plant was constructed. As a result of an operation test, the planned power output of 3.6 MW was achieved, so that it was confirmed the feasibility of the AHAT as a power-generating system. Moreover, the 40 MW-class AHAT test facility was developed and confirmed practicability of the AHAT system with a heavy-duty gas turbine for industrial use. In these AHAT systems, a cluster nozzle burner configuration, which has many coaxial jet streams of fuel and air, was adapted to cope with both flame stability and NOx reduction problems. From the test results, NOx emission is expected to be less than 10ppm for the future commercial AHAT system.

著者

三上 真人 大八木 大史 小嶋 直哉 菊池 政雄 若嶋 勇一郎 依田 真一

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 = Journal of the Combustion Society of Japan (ISSN:13471864)

巻号頁・発行日

vol.45, no.134, pp.238-247, 2003-11-30

参考文献数

30

被引用文献数

3

---

<p>A new concept of the droplet array generation technique was proposed to realize a high quality and high reliability performance of microgravity experiments of multiple-droplet combustion. Each fuel droplet was formed on the intersection of the X-shape fine SiC fibers by supplying the liquid fuel through a fine glass tube. Several sets of the X-shape fibers and corresponding fine glass tubes were aligned at an interval to make a droplet array. All the droplets in array were simultaneously generated in a short time. In flame spread experiments, an end-droplet was ignited by a hot-wire igniter to initiate the flame spread along the array. Microgravity experiments of droplet array combustion were demonstrated with the new droplet array generation technique using a drop experiment facility MGLAB in Japan. In microgravity, large droplets, which were often failed to be generated in normal gravity, were successfully generated through this method. The present technique is also effective in droplet array combustion experiments using a high-volatility fuel, whose prevaporization is not negligible. The flame spread rate and the flame spread limit of linear droplet arrays were compared with existing experimental results. Effects of the suspending fiber on the flame spread were also discussed.</p>

著者

大聖 泰弘

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.53, no.163, pp.37-41, 2011 (Released:2018-01-26)

参考文献数

4

---

Significant reductions in NOx and particulate emissions are required in diesel engines keeping their inherent high efficiency whereas spark-ignition or gasoline engines have achieved sufficiently low emission characteristics by using precise fueling control and three way catalysts. Toward 2020 and beyond, more emphasis will be placed on improvements in fuel economy in both engines to reduce oil dependence in the transportation sector, thereby mitigating global warming. It is essential to optimize combinations of technologies related to combustion, aftertreatment and fuel properties to achieve higher efficiency. Combustion technologies include downsizing the engine with turbocharging, multiple direct injection, exhaust gas recirculation and so forth. Homogeneous charge compression ignition will also be employed at part load for both engine types. For these purposes, detailed numerical combustion and chemical kinetics modeling should be developed and utilized not only to understand fuel-air mixture formation and combustion phenomena but also to devise, design and control advanced combustion systems. Such models must carefully be validated by comparing numerical results with detailed measurements associated with these phenomena.

著者

新井 充

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.60, no.193, pp.150-155, 2018 (Released:2019-02-15)

参考文献数

10

---

As an introduction of the special issue for the combustion science in fireworks, features of Japanese fireworks, competitions of fireworks display, names/gyokumei of individual firework, and science of fireworks are explained. The science of fireworks include physical, health, and environmental issues related to fireworks, such as searching of substitute for sensitive oxidizing substance, preventing mass explosion, searching of substitute for toxic or harmful ingredients, and preventing smoke emission.

著者

江崎 泰雄

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.56, no.178, pp.308-316, 2014 (Released:2018-01-26)

参考文献数

10

被引用文献数

1

---

It is well-known that the deposits accumulated excessively in automobile engine affect the exhaust emission and drivability. Accordingly, the accumulation of the deposit is one of the serious problems to be solved for developing high performance engines. We have been studying the analytical methods of the deposit formation in order to clarify the cause of the deposit accumulation. The methods introduced in this documentation are as follows. First, the deposits were classified into two types of seven components by the differences in their formation origins and environments; four components from fuel, three components from engine oil. Next, the characteristics of these components were determined by four kinds of analytical techniques, and the seven components could be distinguished from one another by four kinds of analytical indexes; chemical structure, elemental composition, thermal gravimetric property and solubility. Furthermore, by using these indexes, the deposit formation factors such as formation origins, formation environments and formation routes could be estimated. In addition to the above methods, the key points to keep in mind for the deposit countermeasure were also described.

著者

堤 敦司

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.50, no.151, pp.39-43, 2008 (Released:2018-01-26)

著者

秋濱 一弘

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.59, no.187, pp.49-54, 2017 (Released:2018-02-15)

参考文献数

21

被引用文献数

6

---

Gasoline vehicles, particularly, Gasoline Direct Injection (GDI) vehicles were subjected to regulations of PM (Particulate Matter) emissions because of the sales increase of GDI vehicles in the market. In this article, the emissions standards of PM for gasoline vehicles in Japan, EU and USA (EPA) are reviewed, and the latest regulatory trend are compared. The outline of PM generation in a GDI engine are explained as the fundamental information. In cold-fast-idle condition, for example, PM emissions in GDI engine originate from the wall fuel films produced by the fuel jet. The reported chemical compositions of exhaust PM are summarized. The major component is found to be Elemental Carbon (EC). Finally, the need for the modeling of PM generation is discussed for the numerical simulation in order to investigate the GDI engine with lower PM emission in the future.

著者

壹岐 典彦 倉田 修

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.58, no.186, pp.215-222, 2016 (Released:2017-12-21)

参考文献数

15

---

Ammonia is a carbon-free fuel and one of the candidates of hydrogen carrier. R&D of a gas turbine firing ammonia is not new issue but there are not successful results for a long time. AIST carried out demonstration tests with the aim to show the potential of ammonia-fired power plant. 50kW class turbine system firing kerosene is selected as a base model. A standard combustor is replaced by a prototype combustor which enables a bi-fuel supply of kerosene and fuel gas. The gas turbine started firing kerosene and increased its electric power output. After achievement of stable power output, ammonia gas was started to be supplied and its flow rate increased gradually. Over 40kW power output was achieved by firing ammonia gas only and over 40kW power output was also achieved by co-firing methane and ammonia. Ammonia gas supply increases NOx in the exhaust gas dramatically. However NOx removal equipment can reduce NOx successfully. The emission of NO and unburnt ammonia depends on the combustor inlet temperature.

著者

原 人志

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.52, no.162, pp.275-279, 2010 (Released:2018-01-26)

参考文献数

2

---

Hot water plays an indispensable part of our present daily life. It can be conveniently usable for everyone since the instantaneous hot water heater was developed and widespread in the market. This term, convenience, actually means that we can use hot water with required temperature and quantity on demand. In the appliance, water flow and temperature sensors are actuated and calculate the amount of energy to create the hot water with requested temperature. To realize the supply of comfortable hot water in this process, combustion must be very significant phenomenon, which can convert the enthalpy of the fuel to the heat revelation quickly. Historically hot water heater has been changed to meet the needs of end users and observes regulations to protect the environment (downsizing, weight saving, low noise and low hazardous emission). According to the modification of hot water heater, burner has also been evolved so as to attain high-intensity combustion and high stability, namely from famous conventional Bunsen type burners to the present burner referred to as low NOx emission burner. It can achieve the lean combustion in which flame is surrounded with rich flame to compensate for its weak stability. These burners can be developed mainly by many engineers' aspiration with try-and-error activity rather than calculating with the fundamental academic knowledge of combustion. Presently, more distinguished burner improvement has been so hard because many configurations has been tried already, therefore, it is expected that new breakthrough invention will be created in the field of academic combustion study and will leads to the development of new fine burner.

著者

岩井 保憲 野本 秀雄 佐々木 隆 筧 敦行 伊東 正雄 佐藤 岩太郎 Rodney J. ALLAM Jeremy E. FETVEDT

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.57, no.182, pp.274-279, 2015 (Released:2018-01-26)

参考文献数

13

---

Carbon dioxide (CO2) emissions from thermal power plants are one of the primary causes of global warming. As global demand for energy increases while environmental regulations tighten, novel power generation cycles are being developed to meet market needs while accommodating green requirements. To meet this demand in the global market, Toshiba has been engaged in the development of an environmentally conscious thermal power generation system applying a supercritical CO2 cycle (Allam cycle) developed by 8 Rivers in cooperation with U.S. companies: 8 Rivers Capital, NET Power, LLC; Chicago Bridge & Iron Company; and Exelon Corporation. The Allam cycle is an approach (with high pressure, low pressure ratios, oxy-fuel combustion and CO2 as a working fluid) that efficiently produces power in a compact plant, avoids NOx emissions, makes efficient use of clean-burning natural gas and can generate high-pressure carbon dioxide for enhanced oil and gas recovery in the field. We have been engaged in the development of a 25 MW-class pilot plant. In this project, Toshiba has been assigned the development of key equipment, including a high-temperature and high-pressure turbine and a combustor, for this thermal power generation system aimed at realizing a 295 MW-class commercial plant.

著者

井田 民男

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.57, no.181, pp.214-221, 2015 (Released:2018-01-26)

参考文献数

7

被引用文献数

1

---

Currently, various energies such as fossil fuels and nuclear power are considerable expenditures. Resource depletion and environmental issues are taking place by activation of various problems and economic activity due to population growth in developing countries. However, in order for society to develop, energy, such as natural energy, is required have been studied for this purpose. We are grappling with new solid bioenergy development named Biocoke. This Biocoke has new solid fuel characteristics with high density and high compressive strength. Firstly, this article reported on new bio-solid fuel which has different density and observed its combustion phenomenon. Through the observation of combustion for bio-solid fuel with different density from 0.8∼1.4 g/cm3, we quantitatively derived ignition limit of biosolid fuel about the difference of density. Thus, we confirmed time continuing the flame and char combustion and observed the situation of spread of combustion into the inside of solid fuel. Finally, Kinki University launched the Great East Japan Earthquake Reconstruction Support Office in August 2012. Its two main themes are of the reconstruction assistance "From Zero to Plus" and rehabilitation support from the disaster of "To Zero from Minus". We suggested that Biocoke is stabilized for a long time from various data. Especially, we was carried to the dissolution test into water from Biocoke including of adhere radioactive Cs-147. Emission of radioactive material from Biocoke reduced until 25%.

著者

三好 明

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.51, no.157, pp.175-181, 2009 (Released:2018-01-26)

参考文献数

17

---

Some aspects of the “first-principle” approach to the combustion chemistry, as a tool for understanding the chemical kinetics, are introduced and discussed. The traditional quantum chemical approach based on the multi-layered structure of the combustion science is briefly described. For the future progress of the chemical kinetics of combustion, three indispensable components are discussed; (1) the spread of the quantum chemical methods for the wide-spreading areas of combustion chemistry, including heterogeneous / catalytic combustion, catalyst for exhaust processing, and etc., (2) establishment of empirical approach in combustion chemistry based on the knowledge of the organic chemistry and the refinement by theoretical investigations, and, (3) development of the lumping and reduction methods for huge mechanism of the combustion, which is growing larger and larger, not only for the application with CFD, but also to extract the essentials of the complex mechanisms. Examples of the development of empirical rules are described for several types of reactions which are governing the low-temperature oxidation of hydrocarbons related to the engine-knock problems and the new combustion technologies such as HCCI (homogeneously charge compression ignition).

著者

伊東 弘行 酒井 雄人 井田 民男 藤田 修

出版者

一般社団法人 日本燃焼学会

雑誌

日本燃焼学会誌 (ISSN:13471864)

巻号頁・発行日

vol.53, no.164, pp.63-68, 2011 (Released:2018-01-26)

参考文献数

14

---

Utilization of biomass fuel is attracting more attention due to its advantage to the global warming problem. Biocoke (BIC), highly densified biomass briquette, has unique features such as economical advantages for its versatility of biomass resources, high volumetric calorific value because of its high density and high mechanical strength. The BIC made of Reynoutria japonica (Japanese knotweed), cylindrical blocks with 48 mm in diameter and 85 mm in length, are selected in the study. To investigate the fundamental thermal and combustion properties of the BIC, ignition and combustion behaviors are observed in the hot air flow. The results show that the ignition mode and the mass loss rate during the flaming combustion are influenced by the supplied air temperature with an interesting manner. This may be ascribed to the thickness of the heated layer inside the BIC depending on the preheating condition. This is because the heated thickness strongly controls the evolution characteristics of pyrolysis gas and the temperature distribution inside the BIC depends on the distinctive property of the BIC, high density. Finally, a new concept of BIC combustion method is proposed considering the BIC unique physical features as well as its fundamental combustion characteristics.