دانلود و نمایش مقالات مرتبط با Homogeneous charge compression ignition::صفحه 1
دانلود بهترین مقالات isi همراه با ترجمه فارسی 2

با سلام خدمت کاربران در صورتی که با خطای سیستم پرداخت بانکی مواجه شدید از طریق کارت به کارت (6037997535328901 بانک ملی ناصر خنجری ) مقاله خود را دریافت کنید (تا مشکل رفع گردد). 

نتیجه جستجو - Homogeneous charge compression ignition

تعداد مقالات یافته شده: 5
ردیف عنوان نوع
1 Second-law analysis of the reforming-controlled compression ignition
تجزیه و تحلیل قانون دوم احتراق فشرده سازی کنترل شده اصلاح-2020
This paper presents the optimization of energy conversion in a novel reforming-controlled compression ignition system, combining the benefits of low-temperature combustion with high-pressure thermochemical recuperation (mostly from the perspective of the second law of thermodynamics). Further, new insights into ways of improving efficiency are provided. A promising renewable fuel dimethyl ether is analyzed for the first time as a primary fuel. A comprehensive analysis of various factors influencing exergy destruction in the reformingcontrolled compression ignition system in their complex interdependence is also performed for the first time. Exergy mapping results show that approximately 33% of the exergy supplied to the system is destroyed owing to irreversible processes in the cylinder itself, and approximately 5% is destroyed in the reforming system (intercooler, vaporizer, and reformer). The reformer is the main source of exergy destruction in the reforming system. Approximately 45% and 38% of the engine exergy destruction is related to chemical reaction and in-cylinderwalls heat interaction, respectively. The results indicate that the efficiency improvement due to second-law optimization reaches up to 7.1%, and if the compression ratio is increased to 18:1 instead of 16:1, this reaches up to 9.2%. The higher improvement is achieved at the highest loads.
Keywords: Homogeneous charge compression ignition | Fuel reactivity control | Thermochemical recuperation | Exergy analysis | Hydrogen | Dimethyl ether
مقاله انگلیسی
2 Combustion performance, flame, and soot characteristics of gasoline–diesel pre-blended fuel in an optical compression-ignition engine
عملکرد احتراق، شعله، و سوخت دوده ویژگی های بنزین دیزل قبل از مخلوط در یک موتور فشرده سازی احتراق نوری-2016
Among the new combustion technologies available for internal combustion engines to enhance perfor- mance and reduce exhausted emissions, the homogeneous charge compression ignition method is one of the most effective strategies for the compression-ignition engine. There are some challenges to realize the homogeneous charge compression ignition method in the compression-ignition engine. The use of gasoline–diesel blended fuel has been suggested as an alternative strategy to take advantages of homo- geneous charge compression ignition while overcoming its challenges. Gasoline and diesel fuels are ref- erence fuels for the spark-ignition and compression-ignition engines, respectively, both of which are widely used. The application of both these fuels together in the compression-ignition engine has been investigated using a hybrid injection system combining port fuel injection (gasoline) and direct injection (diesel); this strategy is termed reactivity controlled compression ignition. However, the pre-blending of gasoline and diesel fuels for direct injection systems has been rarely studied. For the case of direct injec- tion of pre-blended fuel into the cylinder, various aspects of blended fuels should be investigated, includ- ing their spray breakup, fuel/air mixing, combustion development, and emissions.In the present study, the use of gasoline–diesel pre-blended fuel in an optical single-cylinder compression-ignition engine was investigated under various conditions of injection timing and pressure. Furthermore, KIVA-3V release 2 code was employed to model the formation of fuel/air mixtures in the cylinder. Neat diesel fuel was tested, as well as gasoline–diesel blends of 20% and 40% gasoline mass frac- tion. Experiments on the mixed fuels showed that the inclusion of gasoline fuel improved fuel/air mixing, yielding more homogeneous mixtures over wider cylinder areas. The low cetane index of gasoline fuel induced long ignition delays in the mixed fuels. Compared with neat diesel combustion flame, blended fuel did not produce the soot flame, white-yellow flame. Soot intensity was calculated based on captured flame images, and its variations were investigated as a function of fuel type and injection conditions.© 2016 Elsevier Ltd. All rights reserved.
Keywords: Gasoline–diesel blended fuel | Fuel/air mixture | Injection timing | Injection pressure | Flame image | Soot emission | Optical engine | Compression-ignition | KIVA-3V
مقاله انگلیسی
3 Towards a comprehensive understanding of the influence of fuel properties on the combustion characteristics of a RCCI (reactivity controlled compression ignition) engine
به سوی یک درک جامع از تاثیر خواص سوخت در ویژگی های احتراق (واکنش کنترل احتراق تراکمی) موتور HCCI-2016
The influence of fuel chemical properties on combustion characteristics of a RCCI (reactivity controlled compression ignition) engine was investigated using multi-dimensional simulations. The operating ranges of combustion phasing (CA50) for gasoline/diesel and methanol/diesel RCCI combustion were determined with respect to limited boundaries of fuel efficiency, RI (ringing intensity), and NOx (nitrogen oxide) emissions. The results indicated that a more retarded CA50 was necessary for methanol/diesel RCCI to avoid excessive RI due to its fast combustion rate. Because of the shortened combustion duration, reduced incomplete combustion, and lower heat transfer losses, improved fuel efficiency was achieved by methanol/diesel RCCI than gasoline/diesel RCCI. The trade-off relationship between RI and EISFC (equivalent indicated specific fuel consumption) could be defeated by increasing premixed fuel ratio (methanol or gasoline). For methanol/diesel RCCI, the more retarded CA50 was the primary reason for the higher sensitivity of CA50 to the variation of inecylinder initial temperature (TIVC), which conse- quently could lead to higher cyclic variations. In addition, the weakened low temperature heat release of methanol/diesel also deteriorated the stability of CA50 with the variation of TIVC. Overall, with optimized premixed fuel ratio, RCCI combustion demonstrated more advantages in EISFC, RI, controllability, and stable operation over HCCI (homogeneous charge compression ignition) combustion for a wide load range.© 2016 Elsevier Ltd. All rights reserved.
Keywords: RCCI (Reactivity controlled compression ignition) | Gasoline/diesel | Methanol/diesel | Fuel chemical properties | Operating range of combustion phasing
مقاله انگلیسی
4 Bio-diesel in homogeneous charge compression ignition (HCCI) combustion
بیودیزل در احتراق شارژ احتراق تراکمی همگن (HCCI)-2016
The continuously growing energy demands and the fast depleting fossil fuels reserves has led the research towards seeking alternative fuels and combustion concepts to combat the challenges. Biodiesel is one of the potential alternative fuels due to its being renewable in nature. Use of biodiesel in CI engines is generally found to reduce emissions of hydrocarbons (HC), carbon monoxide (CO), and particulate matters (PM); but to increase emission of oxides of nitrogen (NOX) as compared to conventional diesel fuel. Homogeneous charge compression ignition (HCCI) combustion, an advanced combustion concept for internal combustion (IC) engines, is believed to be a promising one due to its high efficiency and lower NOX and PM emissions. However, some issues such as difficulty in combustion phasing control, high levels of UHC and CO emissions, limited range of operation, cold starting problem, difficulty in homogeneous mixture preparation, abnormal pressure rise with noise, lacking in prompt response during cycle transient, engine control strategies and systems, cylinder to cylinder variation and the lack of accurate chemical mechanism and precise combustion model need to be resolved for successful operation of HCCI engine. The characteristic feature of HCCI combustion is the requirement of preparing a homogenous mixture before the start of combustion. In HCCI combustion, the entire combustion process lacks a direct method for the control of ignition timing and combustion rate, which are rather controlled primarily by chemical kinetics, and to a lesser degree, by turbulence and mixing. Biodiesel and its blends with diesel, if coupled properly with HCCI combustion concept, has the potential to reduce the exhaust emissions substantially, while maintaining the performance standards close to the conventional compression ignition (CI) engines. This paper reviews the concepts and methods of HCCI combustion and provides an overview of use of biodiesel in conventional compression ignition direct injection (CIDI) and HCCI engine.& 2015 Elsevier Ltd. All rights reserved.
Keywords: Biodiesel | HCCI | NOX | Soot
مقاله انگلیسی
5 Homogeneous charge compression ignition combustion: Advantages over compression ignition combustion, challenges and solutions
شارژ همگن فشرده سازی احتراق تراکمی : مزایای فشرده سازی بالای احتراق تراکمی، چالش ها و راه حل ها-2016
The homogeneous charge compression ignition (HCCI) engine uses a relatively new mode of combustion technology. In principle, there is no spark plug or injector to assist the combustion, and the combustion auto-ignites in multiple spots once the mixture has reached its chemical activation energy. It is noticeably faster than either compression ignition (CI) or spark ignition combustion (SI). The HCCI combustion mode provides better thermal efficiency and maintains low emission by modifying CI as well as SI engines. A wide variety of fuels, combinations of fuels and alternative fuels can be used in this technology. However, some challenges including combustion phase control, limited operating range, cold start, a high level of noise and homogeneous charge preparation need to be overcome for successful operation of HCCI engines. The objective of this study is to illustrate the engine performance and emission characteristics of HCCI engines at different test conditions and various challenges associated with these engines. Also introduced is a potential guideline to overcome these challenges and improve engine performance and emission characteristics. From the review, it can be concluded that HCCI combustion can be applied in existing CI engines with modifications and the most significant result of applying this combustion is the lower NOx and soot emissions with almost the same performance as with CI combustion.& 2015 Elsevier Ltd. All rights reserved.
Keywords: HCCI | Compression ignition | Engine performance | Emission | Combustion phase
مقاله انگلیسی
rss مقالات ترجمه شده rss مقالات انگلیسی rss کتاب های انگلیسی rss مقالات آموزشی
logo-samandehi
بازدید امروز: 4483 :::::::: بازدید دیروز: 3097 :::::::: بازدید کل: 38750 :::::::: افراد آنلاین: 46