Investigation of Clean Diesel Combustion with Oxygenated Fuels in a Constant-volume Combustion Chamber Using Forward Illumination Light Extinction Technique PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Investigation of Clean Diesel Combustion with Oxygenated Fuels in a Constant-volume Combustion Chamber Using Forward Illumination Light Extinction Technique PDF full book. Access full book title Investigation of Clean Diesel Combustion with Oxygenated Fuels in a Constant-volume Combustion Chamber Using Forward Illumination Light Extinction Technique by Yi Xu. Download full books in PDF and EPUB format.
Author: Yi Xu
Publisher:
ISBN: 9780549097723
Category :
Languages : en
Pages : 217
Get Book Here
Book Description
A fully automatically controlled constant-volume spray chamber was designed and fabricated to provide a stable and controllable environment to study diesel combustion. The chamber also has a larger ambient temperature and ambient oxygen concentration range than a diesel engine. Therefore, the chamber facilitates the investigation of soot formation mechanism and ultimately helps to achieve high efficient clean diesel combustion.
Author: Yi Xu
Publisher:
ISBN: 9780549097723
Category :
Languages : en
Pages : 217
Get Book Here
Book Description
A fully automatically controlled constant-volume spray chamber was designed and fabricated to provide a stable and controllable environment to study diesel combustion. The chamber also has a larger ambient temperature and ambient oxygen concentration range than a diesel engine. Therefore, the chamber facilitates the investigation of soot formation mechanism and ultimately helps to achieve high efficient clean diesel combustion.
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 980
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Emission standards for diesel engines in vehicles have been steadily reduced in recent years, and a great deal of research and development effort has been focused on reducing particulate and nitrogen oxide emissions. One promising approach to reducing emissions involves the addition of oxygen to the fuel, generally by adding an oxygenated compound to the normal diesel fuel. Miyamoto et al. [1] showed experimentally that particulate levels can be significantly reduced by adding oxygenated species to the fuel. They found the Bosch smoke number (a measure of the particulate or soot levels in diesel exhaust) falls from about 55% for conventional diesel fuel to less than 1% when the oxygen content of the fuel is above about 25% by mass, as shown in Figure 1. It has been well established that addition of oxygenates to automotive fuel, including both diesel fuel as well as gasoline, reduces NOx and CO emissions by reducing flame temperatures. This is the basis for addition of oxygenates to produce reformulated gasoline in selected portions of the country. Of course, this is also accompanied by a slight reduction in fuel economy. A new overall picture of diesel combustion has been developed by Dec [2], in which laser diagnostic studies identified stages in diesel combustion that had not previously been recognized. These stages are summarized in Figure 2. The evolution of the diesel spray is shown, starting as a liquid jet that vaporizes and entrains hot air from the combustion chamber. This relatively steady process continues as long as fuel is being injected. In particular, Dec showed that the fuel spray vaporizes and mixes with air and products of earlier combustion to provide a region in which a gas phase, premixed fuel-rich ignition and burn occurs. The products of this ignition are then observed experimentally to lead rapidly to formation of soot particles, which subsequently are consumed in a diffusion flame. Recently, Flynn et al. [3] used a chemical kinetic and mixing model to study the premixed, rich ignition process. Using n-heptane as a representative diesel fuel, they showed that addition of an oxygenated additive, methanol, to the fuel reduced the concentrations of a number of hydrocarbon species in the products of the rich ignition. Specifically, methanol addition reduced the total concentrations of acetylene, ethylene and 1,3-butadiene, as well as propargyl and vinyl radicals, in the ignition products. These are the same species shown in a number of studies [4-6] to be responsible for formation of aromatic and polycyclic aromatic species in flames, species which lead eventually to production of soot. Flynn et al. did not, however, examine the kinetic processes responsible for the computed reduction in production of soot precursor species. At least two hypotheses have been advanced to explain the role that oxygenated species play in diesel ignition and the reduction in the concentrations of these species. The first is that the additive, methanol in the case of Flynn et al., does not contain any C-C bonds and cannot then produce significant levels of the species such as acetylene, ethylene or the unsaturated radicals which are known to lead to aromatic species. The second hypothesis is that the product distribution changes very naturally as oxygen is added and the overall equivalence ratio is reduced. In the present study, we repeat the ignition calculations of Flynn et al. and include a number of other oxygenated species to determine which of these theories is more applicable to this model.
Author: Coordinating Research Council. Coordinating Fuel and Equipment Research Committee
Publisher:
ISBN:
Category : Diesel fuels
Languages : en
Pages : 44
Get Book Here
Book Description
Author: Bansun Chang
Publisher:
ISBN:
Category :
Languages : en
Pages : 376
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 1
Get Book Here
Book Description
Methods of producing non-sooting, low flame temperature diesel combustion were investigated in an optically-accessible, quiescent constant-volume combustion vessel under mixing-controlled diesel combustion conditions. Combustion and soot processes of single, isolated fuel jets were studied after auto-ignition and transient premixed combustion and while the injector was fully-open (i.e. during the mixing-controlled phase of heat release for diesel combustion). The investigation showed that small injector tip orifices could be used to produce non-sooting and low flame temperature combustion simultaneously. The use of small orifices was shown to enable non-sooting and low flame temperature combustion in two different ways as summarized below. A more detailed description of the experimental methods and results is provided in Ref. [1-3]. First, using an injector tip with a 50 micron orifice and ambient oxygen concentrations as low as 10% (simulating the use of extensive EGR), a fuel jet was non-sooting at typical diesel ambient temperatures (1000 K). Second, using the same injector tip at a reduced ambient gas temperature (850 K), but with 21% oxygen, it was shown that non-sooting, mixing-controlled combustion occurred at the lift-off length in a fuel-air mixture with a cross-sectional average equivalence ratio of approximately 0.6-suggesting that the quasi-steady combustion was fuel-lean and thereby avoided the formation of a diffusion flame. The adiabatic flame temperature with reduced ambient oxygen concentration or fuel-lean combustion was approximately 2000 K, compared to typical diesel flame temperatures that exceed 2600 K. The 50 micron orifice results above were obtained using a No. 2 diesel fuel. However, using an oxygenated fuel (20 wt% oxygen), the investigation showed that the same low temperature combustion, either with reduced ambient oxygen concentration or fuel-lean combustion, was realized with a 100 micron orifice. Although these single, isolated jets do not have jet-jet interactions that would occur in realistic engines, the results are useful for understanding limiting-case behavior of single-jet mixing and combustion during an injection event. The non-sooting and low flame temperature mixing-controlled combustion realized using small orifice tips suggests that the use of small orifices offers the potential for a simultaneous soot and NOx reduction in an engine, much like diesel HCCI combustion. However, further research is needed to determine whether these methods could be successfully implemented in real engines.
Author: Harold Colby Gerrish
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 40
Get Book Here
Book Description
Author: Brian Eric Hallgren
Publisher:
ISBN:
Category :
Languages : en
Pages : 144
Get Book Here
Book Description
Author: Richard Carnot Leupold
Publisher:
ISBN:
Category : Diesel fuels
Languages : en
Pages : 90
Get Book Here
Book Description
Author: Society of Automotive Engineers
Publisher:
ISBN:
Category : Automobiles
Languages : en
Pages : 322
Get Book Here
Book Description
