Масло в нафтата ???

[dani_94]

Като се събрахте толкова химици, може ли да ми кажете с какво мога да си измеря цетановото число на дизеловото гориво ???

И втори въпрос: Кое вещество или течност се слага в добавките за да се вдига цетановото число ???

Или ако знаете такава добавка която се ползва само за вдигане на цетановото число.

[yossarian]

Като се събрахте толкова химици...

Чаках колегата, дето е инжинер-химик по образование да се произнесе ама сигурно мисли нещо.
Та ето тук малко информация там са и отговорите на въпросите ти

The Importance of Cetane Number in Diesel Fuel
What is Cetane Number?
• Cetane Number is a measure of the ignition quality of a diesel fuel. It is often mistaken as a measure of fuel quality. Cetane number is actually a measure of a fuel's ignition delay. This is the time period between the start of injection and start of combustion (ignition) of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels.
• Cetane number should not be considered alone when evaluating diesel fuel quality. API gravity, BTU content, distillation range, sulfur content, stability and flash point are also very important. In colder weather, cloud point and low temperature filter plugging point may be critical factors.
Determining Cetane Number
• The optical method for determining cetane number is ASTM test D-613. This method requires the use of an industry standard test engine equipped with accepted instrumentation and operated under specific conditions. In this test, the engine compression ratio is varied for the test sample and reference fuels of known cetane number to obtain a fixed ignition delay. The compression ratio of the sample is bracketed by those of two reference fuels. The cetane number of the sample fuel is determined by estimating between the two reference fuel points.
• Because the ASTM D-613 test is time consuming and expensive, calculated cetane index (ASTM D-976 or D-4737 is often substituted for cetane number. The calculated cetane index is derived from the fuel's density and boiling range. While useful for estimating the cetane number of distillate fuels, this technique can not be applied to fuels containing additives that raise cetane number. These additives do not change the fuel density or distillation profile, so they do not alter the calculated cetane index.
How Does Cetane Number Affect Engine Operation?
• There is no benefit to using a higher cetane number fuel than is specified by the engine's manufacturer. The ASTM Standard Specification for Diesel Fuel Oils (D-975) states, "The cetane number requirements depend on engine design, size, nature of speed and load variations, and on starting and atmospheric conditions. Increase in cetane number over values actually required does not materially improve engine performance. Accordingly, the cetane number specified should be as low as possible to insure maximum fuel availability." This quote underscores the importance of matching engine cetane requirements with fuel cetane number.
• Diesel fuels with cetane number lower than minimum engine requirements can cause rough engine operation. They are more difficult to start, especially in cold weather or at high altitudes. They accelerate lube oil sludge formation. Many low cetane fuels increase engine deposits resulting in more smoke, increased exhaust emissions and greater engine wear.
• Using fuels which meet engine operating requirements will improve cold starting, reduce smoke during start-up, improve fuel economy, reduce exhaust emissions, improve engine durability and reduce noise and vibration. These engine fuel requirements are published in the operating manual for each specific engine or vehicle.
• Overall fuel quality and performance depend on the ratio of parafinic and aromatic hydrocarbons, the presence of sulfur, water, bacteria, and other contaminants, and the fuel's resistance to oxidation. The most important measures of fuel quality include API gravity, heat value (BTU content), distillation range and viscosity. Cleanliness and corrosion resistance are also important. For use in cold weather, cloud point and low temperature filter plugging point must receive serious consideration. Cetane number does not measure any of these characteristics.
Cetane Improvers / Ignition Accelerators
• U S diesel fuels are blends of distillate fuels and cracked petroleum hydrocarbons. The cracked hydrocarbons are low cetane compounds, largely due to their aromatic content. To meet the cetane number demands of most diesel engines, cetane improvers must be added to these blends. The lower cetane cracked compounds are less responsive to these cetane improvers than the higher cetane paraffinic fuels.
• Cetane improvers modify combustion in the engine. They encourage early and uniform ignition of the fuel. They discourage premature combustion and excessive rate of pressure increase in the combustion cycle. Depending on the amount of high versus low cetane components in the base fuel, typical alkyl nitrate additive treatments can increase cetane by about 3 to 5 numbers (1:1000 ratio). With high natural cetane premium base fuels (containing a high percentage of parafins) and a 1:500 treatment ratio, cetane may increase up to a maximum of about 7 numbers.
• Most cetane improvers contain alkyl nitrates which break down readily to provide additional oxygen for better combustion. They also break down and oxidize fuel in storage. This generates organic particulates, water, and sludge - all of which degrade fuel quality. The result is often a fuel which no longer meets even minimum requirements. Because of these drawbacks, nitrate cetane improvers are not used in Fuel Magic.
• Fuel MagicTM is blended to improve oxidation stability while providing a cetane number increase of 2 to 3 numbers. Fuel Magic improves combustion while reducing oxidation and particulate formation, increasing storage stability, and enhancing fuel quality.
Do Cetane Improving Additives Really Improve Fuel Quality?
• Fuel quality is defined by the physical property specifications given in the ASTM Standard Specification for Diesel Fuel Oils, ASTM D-975. Carbon residue, ash and sulfur increase engine wear and deposit formation. Premium diesel fuels should have lower specifications for these properties. Additionally, premium diesel fuels should be more stable in storage than standard fuels, so the premium fuel quality you purchase won't degrade over time. This is the area where nitrate-containing cetane improvers cause problems. Fuel Magic contains no alkyl nitrates.
Specifying Diesel Fuel
• Cetane number is an important measure of ignition quality, or cold-starting ability. API gravity is an excellent indicator of heat value, which translates into fuel economy and power. The distillation curve reflects the molecular weight distribution, with higher boiling fractions providing better lubrication, higher cetane - and more deposits. Sulfur content is directly related to corrosion; this needs to be as low as possible. Oxidation stability, water, and sediment content affect the storage life of the oil. For winter use, low cloud point and low temperature filter plugging point are critical to uninterrupted operation. To insure the best quality fuel for your diesel engines, follow the engine manufacturer's specifications for all these characteristics.

[dobrin]

За добавките в дизеловото гориво

[dobrin]

Аз карам с Diesel Power на Gold Eagle май беше. Струва 18 лв и нещо, ама едно шишенце е за 375 литра. Повишава цетановото число с 5 до 10 единици. И наистина действа. Препоръча ми го моя майстор и според него е единственото което действа. Според мен, от тези които съм пробвал поне, е единствената добавка, която като сложиш и усещаш разликата при всеки един режим на работа на двигателя. От време на време се намира на бензиностанцията на Газтрейд на Цариградско преди разклона за Младост. Но всеки път е различно, защото не се купува толкова често - стига минимум за 5000 км при разход около 7л/100км. Единствения недостатък е, че трябва да се внимава при дозирането, щото се сипва по много малко.

[yossarian]

...

Ето как да си мериш цетановото число в мазето
The cetane number measures the ignition quality of a diesel fuel.

It is the % volume of cetane ( n-hexadecane, Cetane Number = 100 ) in
alpha methyl naphthalene ( Cetane Number = 0 ), that provides the specified
standard of 13 degrees ( crankshaft angle ) ignition delay at the identical
compression ratio to that of the fuel sample. These days, heptamethyl
nonane - with a Cetane Number of 15 - is used in place of alpha methyl
naphthalene because it is a more stable reference compound.

It is measured in special ASTM variable compression ratio test engine
that is closely controlled with regard to temperatures ( coolant 100C,
intake air 65.6C ), injection pressure ( 1500psi ), injection timing 13 degrees
BTDC, and speed (900rpm ). The compression ratio is adjusted until
combustion occurs at TDC ( the ignition delay is 13 degrees ). The test
is then repeated with reference fuels with five cetane numbers difference,
until two of them have comporession ratios that bracket tthe sample.
The cetane number is then determined by interpolation, and the higher
the Cetane Number, the shorter the delay between injection and ignition.
Now, if the fuel is pure hydrocarbons ( does not contain cetane number
improving agents like alkyl or amyl nitrates ) then the cetace number
can be predicted fairly well using some physical properties, such as
boiling point and aniline point.

It's obvious from the above that the higher the cetane number ( 100 = normal
alkane, 15 = iso-alkane ), then the lower the octane number ( 100 = iso-alkane,
0 = normal alkane ). This is because the desirable property of gasoline to
prevent knock is the ability to resist autoignition, whereas for diesel, the
desirable property is to autoignite. The octane number of normal alkanes
decreases as carbon chain length increases, whereas the cetane number
increases as the carbon chain length increases. Many other factors also
affect the cetane number, and around 0.5 volume % of cetane number
improvers will increase the cetane number by 10 units. Cetane number
improvers can be alkyl nitrates, primary amyl nitrates, nitrites, or peroxides.

In general, aromatics and alcohols have low cetane numbers ( that's why
people using methanol in diesels convert it to dimethyl ether ).One of
the obvious effects of running on low cetane number fuel is the increase
in engine noise.

Typically engines are designed to use fuels with Cetane Numbers of 40-55,
because below 38 a more rapid increase in ignition delay. The significance of
the cetane number increases with the speed of the engine, and large, low
speed diesel engines often only specify viscosity, combustion and
contaminant levels, as Cetane Number requirement of the engine is met by
most distillate and residual fuels that have the appropriate propeties.
High speed diesel engines ( as in cars and trucks ) virtually all are designed
to accept fuels around 50 Cetane Numbers, with higher numbers being a
waste.

However, Cetane Number is only one important propety of diesel fuels, with
three of the others being also very important. Firstly, the viscosity is
important because many injection systems rely on the lubricity of the fuel for
lubrication. Secondly, the cold weather properties are important, remember that
normal alkanes are desirable, but the desirable diesel fraction alkanes
have melting points above 0C temperature, so special flow-enhancing
additives and changes to the hydrocarbon profiles occur seasonally.
That's why it's never a good idea to store diesel from summer for winter
use. Thirdly, diesel in many countries has a legal minimum flash point
( the minimum temperature it must attain to produce sufficient vapours
to ignite when a flame is applied. In all cases it's usually well above
ambient ( 60C+, kerosine is 37C+, whereas gasoline is typically below
-30C ), and anybody mixing a lowert flash point fraction with diesel will
usually void all insurance and warranties on the vehicle. The recent
increase in blending fuels has resulted in significantly more frequent
analyses of fuel tank contents from diesel vehicle fires.

From all of the above, you can see some common factors emerging,
larger normal alkanes are desirable, and they also burn with a less
smoky flame and have higher flash points than gasoline and kerosine,
making them also desirable for home heating fuels, however the relatively
expensive Cetane Index improvers have no value in heating fuels.

Most engines show an increase in ignition delay when the cetane
number is decreased from around 50 to 40, with an increase of 2 degrees
being typical, and minimal advantages accrue of lower CN fuels are used.

Heating oils are often a slightly different fraction, and may have
differing additives ( for cleaner combustion ) to fuels used for high
speed diesel engines. For low speed ( large, stationary and marine
engines ), they often use the cheapest residual fuel oil availble, as
do the larger heating boilers - so there is commonality of fuel as size
increases.

Details of the important, specified properties of various grades
( 1D, 2D, 4D ) of diesel fuel oils can be found in the Annual Book of
ASTM Standards. ASTM D975-93 " Standard Specification for
Diesel Fuel Oils", as can the fuel oil specification for grades
1, 2, 4, 5, and 6 in " Standard Specification for Fuel Oils ASTM
D 396-92. Note that ASTN D975-93 actually defines the low temperature
requirements by dividing the USA into regions. It is possible for
a fuel to meet both specifications, but the diesel specification may have
additional requirements such as Cetane Number and Cloud Point
( temperature at which the fuel goes cloudy ), whereas the Fuel Oil
may have additional limits on the distillation properties, and viscosity at
100C. A fuel has to be tested for all the criteria in each specification
grade before it can be said to comply with the relevant grade in
each specification.

The interchanging and dilution of fuels is performed by
suppliers, taking into account the effect on all of the above, but
especially flash point, as that is closely regulated in many countries.
Adding kerosine and gasoline to diesel can have dramatic, adverse
effects on the flash point, with minimal gains in the flow properties
if the fuel already contains flow-improving additives. Regardless of
what other people may advise, check your insurance policies before
embarking on experimentation. These days, assessors for both vehicle
and insurance companies these days are far more aware of the
signs of the dilution of expensive diesel fuel by cheaper lowerr flash
fuels. Some countries, like NZ, avoid this by having diesel cheaper
than gasoline at the service station, and imposing taxes based on
distance travelled ( as measured by hubometers on vehicle wheels),
number and location of axles, axle loads, and gross vehicle weight,
as they more accurately indicate road damage potential.

[kolgo]

Аз карам с Diesel Power на Gold Eagle май беше. Струва 18 лв и нещо, ама едно шишенце е за 375 литра. Повишава цетановото число с 5 до 10 единици. И наистина действа. Препоръча ми го моя майстор и според него е единственото което действа. Според мен, от тези които съм пробвал поне, е единствената добавка, която като сложиш и усещаш разликата при всеки един режим на работа на двигателя. От време на време се намира на бензиностанцията на Газтрейд на Цариградско преди разклона за Младост. Но всеки път е различно, защото не се купува толкова често - стига минимум за 5000 км при разход около 7л/100км. Единствения недостатък е, че трябва да се внимава при дозирането, щото се сипва по много малко.

oтиваш при вносителя - винаги го има + разни други екстри пък и цената е по тънака-аз си взех 1 литър опаковка за 1 тон гориво и са работата е 6- дига цетановото число,чисти дюзите,предпазва от желиране . удоволствието е 22 лева!

[dobrin]

..oтиваш при вносителя..

Кажи де го тоз вносител де

[TDI-RS]

Чаках колегата, дето е инжинер-химик по образование да се произнесе ама сигурно мисли нещо.

колега, ти като се изказваш така се мислиш за много остроумен ли или какво?
и ако искаш да пуснеш нещо - дай го на български или го преведи като си толкова начетен и искаш да помагаш. някой може би разбираме английски, но съм сигурен, че за други информацията е безполезна.

/ ако обичаш не ми отговаряй, темата не е за водене на диалог /

п.с. за повишаване на цетановото число аз лично ползвам това:

[dobrin]

[img].jpg[/img]

Точно това ползвам и аз, за него писах по - горе

[TDI-RS]

Точно това ползвам и аз, за него писах по - горе

само така!
но искам да вметна понеже и мойта струваше 18.20 лв., както и ти си писал, че видях същата добавка на ОМВ на автомагистрала Хемус е доста по - евтина. та следващият път аз лично ще пазарувам от там!

[dobrin]

Колегата kolgo да каже от къде я взема по-евтино.

[yossarian]

... ако искаш да пуснеш нещо - дай го на български или го преведи като си толкова начетен и искаш да помагаш. някой може би разбираме английски, но съм сигурен, че за други информацията е безполезна.

Относно превода, на времето взимах 5USD на страница. От много време не се занимавам с това. Определено в поста ми има много повече информация от твоя. Който има желание и се интересува ще намери начин. В крайна сметка форума не е образователен да го сдъвча и изплюя готово Ти ако има свободно време що не го преведеш, хем полза ще има за всички.

[веселин]

... ако искаш да пуснеш нещо - дай го на български или го преведи като си толкова начетен и искаш да помагаш. някой може би разбираме английски, но съм сигурен, че за други информацията е безполезна.

Относно превода, на времето взимах 5USD на страница. От много време не се занимавам с това. Определено в поста ми има много повече информация от твоя. Който има желание и се интересува ще намери начин. В крайна сметка форума не е образователен да го сдъвча и изплюя готово Ти ако има свободно време що не го преведеш, хем полза ще има за всички.

Няма смисъл да спорите-има си стандарти за горивата!За Г2 производителя препоръчва не по ниско от 42 цетаново число!За новите двигатели май е по-високо!

[gicho76]

В крайна сметка, ако може някой компетентен да обобщи всичко написано до тук:
1.Какво масло се слага в нафтата - двутактово, синтетично, полусинтетично, минерално, хидравлично?
2.Колко масло се слага в 50л. нафта?
3.Редовно ли се слага маслото или през някакъв пробег?
4.Колко газ за осветление или бензин се слага в 50л. нафта?


Лики Моли 1л. против замръзване на нафтата има в момента на промоция в Kaufland /Пловдив 100%/ на 19лв.

[juve]

Лики Моли 1л. против замръзване на нафтата има в момента на промоция в Kaufland /Пловдив 100%/ на 19лв.

Е, то и в Била-та дойде на 18 лева без промоция, ама чак когато си взех друга Мисълта ми беше, че Кауфланд - пфу