Autogas, the World's Choice | Candan Mühendislik

Advantages of Autogas LPG as Motor Fuel
•Autogas is economical, the main target is fuel saving..

•Autogas provides ease of starting in cold weather.

• Autogas exhaust emissions are lower.
• The maintenance of the autogas system is low.
• There is a more equal distribution of fuel (LPG) to the cylinders.
• Autogas has high octane numbers.
• The combustion of autogas is more efficient.
• Autogas is suitable for operation in lean mixture.
• The lubricating oil of an autogas vehicle lasts longer.
• Engines using autogas leave less residue in the combustion chamber.
• It causes 30% less damage to the ozone layer than petrol.
•Use of autogas provides clean combustion, delays spark plug contamination, burns due to contamination
It does not reduce efficiency.
The exhaust system of an autogas vehicle lasts longer

THE WHOLE WORLD'S CHOICE = AUTOGAS
Autogas and Autogas systems, which have been used in our country since the early 90s, have now made Turkey the 2nd country that consumes the most Autogas in the world. Our country is at the top of Europe in this market, especially due to the fact that the exhaust emission values of autogas systems are very low compared to petrol and diesel vehicles, the positive references made for years, the technological renewal of the systems day by day and the most important reason for preference, being economical. As you know, searching for such alternatives was inevitable in a country that consumes the most expensive petrol in the world. Autogas systems, which are currently the most widely used alternatives, provide us with many advantages.
AUTOGAS ECONOMY
If we examine the economic aspect of the matter, a consumer who is considering installing a sequential autogas system on his vehicle may encounter very different prices. It is possible to say that the most obvious factors affecting this price range are brand, quality, technology, and the number of cylinders of the vehicle to be installed. Quality and long-term trouble-free operation of the system play an important role for conscious consumers. Consumers should give importance to quality rather than their budget when making their choices. Nowadays, we can obtain various information and references from websites and forums before purchasing a product. These can shed light on brands and their quality.
If we give an example through the standard sequential system Smart of Lovato Sequential Autogas Systems; The assembly price of this product is 1.390 TL. If we say that a vehicle owner with a petrol expense of approximately 350 TL per month saves an average of 40% (this percentage may vary depending on the user and the vehicle. 40% is the average savings amount we stated), he will save 140 TL per month. Autogas systems are mostly offered to consumers with 10-month installment options.

In this case, the system will pay its own installments with the monthly savings of 140 TL. After 10 months, your investment will start to return to the consumer. If the consumer's petrol expenses are higher, he will be making a profit as soon as the system is installed. What we are generally trying to explain here is that 40% of the money you pay for petrol per month will be added to your monthly budget. There are not many investments that provide this much profit in such a short time to support the family economy. We are talking about hundreds of liras of additional income per month.
Savings are felt more effectively, especially when going on a long journey. If a long journey is to be made shortly after starting to use the system, the system will immediately amortize most of it. For example, if 600 TL will be spent on petrol to travel on holiday, 240, which is 40%, will be added to your holiday budget.
Similarly, if we calculate monthly petrol expenses for fleet-owning companies based on 40% savings, we encounter very large figures. It is also worth remembering that autogas systems have no maintenance costs other than filter replacement. We can give countless examples of this kind to explain the economic advantages of autogas systems.
CONTRIBUTION TO THE ENVIRONMENT
Although the environmentally friendly features of autogas are not an effective reason for people to prefer these systems, the following information should be kept in mind by consumers. Consumers who will convert to autogas are supported by the state in many parts of the world, although not in our country, due to this environmental factor.
A person needs only 15 cubic meters of clean air per day.

The vehicle can become a respiratory hazard within a 10-minute period. Today, more than two million registered motor vehicles in Istanbul are traveling on the streets and avenues of the city. This figure will give an idea about how effective cars are in air pollution in the air we breathe.

For example, in the emission comparison of a bus using LPG and a EURO II diesel bus, it was determined that the bus using LPG was approximately 23 times less polluting.

PERFORMANCE

As it is known, autogas systems work on the same principle as the intended petrol. For this reason, the only difference in the operation of the vehicle is that it uses petrol instead of petrol as fuel. Autogas will be used. Compared to other alternative automotive fuels, the performance and operating characteristics of autogas-powered vehicles are much more suitable. Engines running on autogas provide users with more powerful, quieter and more flexible use due to the high octane rating of autogas.
SECURITY
For consumers who still have questions about safety, it should be noted that the production and safety controls of these systems are at the same level as petrol or diesel production and controls. There are studies conducted by independent institutions in Europe that have revealed that autogas is at least as safe as petrol and diesel. There are already many international standards that are followed at every stage regarding autogas systems, and these are also applied in our country.

CAN LPG BE USED IN DIESEL ENGINES?
COMBUSTION IN DIESEL ENGINES
Petrol and diesel engines are extremely similar in terms of the thermodynamics of the cycle
, it is very important in terms of the stages of combustion and the control of the event.
reveal differences.
In diesel engines, the air is not subjected to any throttling during intake stroke.
It is completely filled into the cylinder without being left behind. Since the compression ratio is between 12–20
Towards the end of compression, the gas temperature in the cylinder is quite high. Just before TDC
fuel starts to be sprayed and due to high temperature it ignites as soon as it is sprayed.
and burns .
3.1.1 Stages of Combustion
Combustion in diesel engines can be examined in three parts. Regarding combustion in diesel engines
When the indicator diagrams are examined, it is seen that the maximum pressure point is the first phase of the combustion process.
is known as the end point. At the maximum temperature point, the second phase is the slow combustion phase.
is considered to be the moment when it ends and the third phase, afterburning, begins (Safgönül et al. 1999).
Delay Period
Between the start of fuel injection into the combustion chamber and the start of combustion
period or the delay time between the start of spraying and the start of ignition.
The duration of this period depends on the mixture of fuel and air. Pressure, temperature, combustion chamber
The form and the quality of the fuel are the most important factors affecting this period. Pressure and temperature
If it is high, it shortens the delay period. Fuel is injected into the compressed air
time mixes with air. As a result, combustion begins in the overly rich mixture region, but
In poor areas, combustion starts later. High air movement (turbulence) and homogeneous
reduces the mixing delay period. The longer the interval, the more inside
causes fuel to enter. After the first ignition, all the fuel filled into the cylinder
burns uncontrollably (explosively). Fuel injected into the cylinder during the ignition period Increasing the amount of
causes diesel knock (lkılıç 1999).
A typical pressure-crank angle diagram for a diesel engine is shown in Figure 3.1 (a).
In Figure 3.1 (b), from the beginning of spraying (PB) to the end of spraying (PS)
mass fuel injection amount is seen. As can be seen from the figure, it is expressed with point A.
is taken into account from the beginning of spraying to the ignition point expressed by point B. There is a delay of
.
curves shown with full and dashed lines represent fuel-air mixture and fuel-air mixture, respectively.
refer to pressure-crank angle records obtained only with air. Only in the first case
Since there will be an ignition, the two curves separate from each other at point B. Ignition delay time
as stated before, fuel evaporation (physical ignition delay) and
followed by preliminary reactions until the moment of ignition (chemical ignition delay). It consists of
stages. These preliminary reactions occur in the final gas region of petrol engines. It has the same characteristics as the
reactions (Borat et al. 1994).
As mentioned above, it is accepted that it takes a certain time for the fuel droplets to evaporate.
is done. However, a vapor forms around the droplets immediately after spraying.
layer is formed and combustion starts from this vapor layer. after that
evaporation does not affect TG anyway. Therefore, the contribution of evaporation to TG is very high.
not much. However, the reaction rate after ignition is in direct proportion to the evaporation rate.
is proportional. Likewise, the burning rate of the fuel in the vapor phase depends on the air surrounding the vapor layer.
It is proportional to the oxygen concentration. These observations show that combustion and evaporation in diesel engines
indicates that it started before completion (Altın 1998).
If the ignition delay period is long, there is more time for the fuel and air to mix. It means
. The crank rotation angle during the ignition delay is called the delay angle. this angle
is equal to the product of the crank angular speed and the ignition delay time. fuel pump crank Since it depends on the
shaft, the amount of fuel sprayed before ignition varies with the delay angle.
is proportional.
In engines where fuel is injected, such as diesel engines, the fuel/air ratio affects the combustion process.
It is not very important in terms of starting. Because the fuel/air ratio in the cylinder is zero.
There are many points varying between infinity. Combustion has the optimum rate for ignition. It starts from
dots or dots. Spray characteristics or degree of atomization are also
does not affect this infinite value change in the fuel/air ratio. Therefore, their TG It has no significant impact on
.
The most important factors affecting ignition delay are fuel quality, pressure and especially
is temperature. High temperature and pressure shorten the TG time. Fuel jet up to walls
, if the walls are very hot, the TG time is significantly shortened. T.G. Changing the amount of fuel injected during
does not affect the ignition delay.
3.1.1.2 Fast Burning
This phase consists of materials mixed with air within flammability limits during the ignition delay period.
It is formed by the rapid burning of fuel. During this period, the pressure rise in the cylinder
occurs. Maximum cycle pressure occurs during this period. spread all over
The fuel undergoes chemical changes due to flame (lkılıç 1999).
The pressure increase in this second stage of combustion is affected by the following factors:
• Degree of atomization of the fuel; This depends on the design of the vehicle's injection system.
• Amount of fuel injected during the delay; This depends on the length of the TG period.
depends.
• How well the fuel mixes with air during the ignition delay.
The time used for mixing depends on the spray characteristics and, to some extent, the cylinder
Air movements within it have an impact on this factor. Long lasting TG and high
The mixture becomes more perfect at engine speed.
• The amount of fuel injected into the cylinder during the ignition delay is
If too much fuel is injected, some of it combines with oxygen and increases the pressure rise rate.
causes it to increase even further.
From the explanations above, the pressure rise rate and duration are related to the ignition delay time.
It is understood that they are absolutely related. Less mixing of fuel and air before ignition
To allow the TG period to be short and the engine speed to be low to reduce air movement.
should be kept (Altin 1998).
Controlled Combustion
During the ignition delay, the mixing of air and fuel is controlled by the mixing ratio.
is done. Controlled combustion means that the last injected fuel burns after the combustion starts.
is the time between completion and completion. Above 2000°C after rapid combustion The fuel burning with a temperature of
continues until the crank angle of 6° and the flame at this time is bright.
A non-existent wife is in the form of a flame. This period until the exhaust valve opens
must be completed.
In order to have high efficiency, combustion must be completed as close as possible to the U.O.N.
is required. In this regard, in the third stage, the oxygen/unburnt fuel ratio is high and the mixture is mixed quickly.
And it is desired to be perfect. Even if fuel injection is complete before ignition
Poor spray characteristics may cause prolonged third-stage combustion.
In cases where injection extends to the third stage, as in low-speed diesels,
In addition to the mixing speed, the spray rate also affects the combustion process. These engines are in the third stage
It should be designed to make the fuel-air mixture very effective (lkılıç 1999).
CLASSIFICATION OF DIESEL FUEL
According to ASTM standards, diesel fuels are evaluated in three grades.
No.1-D: Obtained from the distillation of petroleum. Working at different speeds and loads
It is a volatile-distillate diesel fuel used in engines.
No.2-D: Containing distillate and cracking products, No. It has less evaporation feature compared to l-D
It is a fuel for heavy duty and industrial engines.
No.4-D: Low or medium speed, consisting of distillation and cracking products and some residues
It is the fuel of their engines.
3.3 FEATURES OF DIESEL FUEL
The combustion process in a diesel engine with a flat combustion chamber depends on the properties of the fuels.
varies.
3.3.1 Flammability (Cetane Number)
The most important feature of diesel fuel is the cetane number. Cetane number determines the combustion quality of diesel fuel.
It is a number that indicates and can be measured like the octane number in petrol. There are two separate methods in cetane number determination.
special liquid fuel is used (Cetane and Alpha-methyl naphthalene). In various proportions of these When the fuel obtained with the
mixture gives knock equal to the knock of the sample fuel, this situation
It is determined as the cetane percentage of that fuel. For example, 45% cetane and 55% alpha-methyl naphthalene
The knock of the mixture in the standard test engine is determined by the cetane number of the diesel fuel to be determined. If it is equal to
knock, the cetane number of this fuel is 45 (Karakus, 2000).
Determination of cetane number requires a difficult, expensive and time-consuming test method.
Instead of the cetane number, the "Diesel Index" is used, which will provide information about this value. diesel The
index can be calculated using formulas. For this, the aniline point and API gravity of the fuel Values such as
must be known. Apart from this, the method of determining the cetane number Nomographs are used as
.
Nomographs are based on API gravity and the average boiling point at which 50% of the fuel has distilled. It was prepared based on
. Nomographs normal distillate, thermal and catalytic
They give good results for diesel fuels taken from cracking units. Set the cetane number
If additives are added to the fuel in order to increase it and the fuel oil in the fuel is more
If volatile substances, pitch, animal and vegetable oils and synthetic fuels are present, the diesel produced
index determination does not correspond to the cetane number found experimentally.
The cetane number of normal diesel fuel should be 45. As a result, the diesel index of the fuel
As it rises, its self-ignition ability increases. Cetane number between 45 and 50 and diesel The
index is more or less the same. At values below 45, the diesel index is more than the cetane number.
is small, on the contrary, it is slightly larger for values above 50. Diesel of normal diesel fuel The
index is at least around 45 (Karakus 2000).
It is very closely related to the hydrocarbon types a diesel fuel contains. paraffinic
hydrocarbons increase the cetane number. Naphthenic hydrocarbons provide mediocre cetane numbers
does. The effect of olefins on cetane number has not been determined precisely. aromatic
Hydrocarbons provide low cetane number.
Methods for Determining Cetane Number
The flammability of diesel fuels depends on the structure of the fuel molecules and the components inside them.
is strongly connected. In diesel knock, the independent variable to be taken as basis for knock tendency
is the ignition delay. Therefore, there are factors that affect the ignition delay positively or negatively.
All factors are also effective in diesel knock.
If TG decreases in the engine under certain design and operating conditions, the combustion rate also decreases and combustion
presents the appearance of constant pressure combustion rather than constant volume. of diesel fuels
The knock properties are attributed to their flammability. TG also increases their flammability It is possible to describe it with the values
. There are two types of methods for determining the ignition delay time.
method is used. l) Critical compression ratio method, 2) Critical intake pressure method
• Critical compression ratio method: Some of the CFR-Diesel engine used in this method
features are stated in Table 3.3 (Karakus 2000).
Table 3.3 Some features of the CFR-Diesel engine (Karakus 2000).
Company: Waukesha
Number of Cylinders: 1
Engine Speed: 900 1/min
Cooling Water Temperature: 373 K
Intake Air Temperature: 339 K
Spray Advance: 13° KMA
Ignition Delay: before TDC: 13° KMA
Compression Ratio: Variable
According to ASTM Designation D613-61T, it is installed in one of the three fuel chambers of the CFR-Diesel engine.
The fuel to be investigated is added and the engine is rotated with the electric motor at a speed of 900 1/min. only 3 During spraying lasting
seconds (~23 times) the TG-Meter will give a TG of 13° KMA The compression ratio is changed as follows
21
. Since PA = 13° KMA, TG = 13° KMA When
comes, the pressure increase will be set to full T.O.N. This compression ratio is
is the critical compression ratio of the fuel. For example, the critical compression ratio for n-heptane is k = 8.6; i-octane For
, k = 17.4.
Cetane (C16H34, i.e. hexadecane) and heptamethylnonane (C16H34), which are called reference fuels
This time, fuel with specific volumetric mixtures is sent to the engine from the other two fuel chambers where it is placed.
reference fuel is shipped. Volumetric of cetane in the reference fuel giving the same TG and k values
percentage (YS) is determined. The cetane number (SS) of the fuel under consideration is;
SS = YS is found by the relation +0.15 (100-Ys).
Here, it is assumed that cetane is 100 and heptamethylnonane is 15 units cetane.
Generally, after the eK value of the tested fuel is found,
SS value can be found. Reference fuels are used for precise SS detection.
k value, cetane numbers SS, and SS of the fuel examined; Compression of two types of reference fuel Interpolation can be made between the ratios
( k1 > k > k2: ). However, in standards SS2 –
Interpolation is allowed for SS1, 5 units. Used to replace heptamethylnonane
alpha methylnaphthalene (C11H10,1-methylnaphthalene) was used and its SS value was zero (0).
, the volumetric percentage of cetane fuel in the reference fuel is directly
was taken as the SS value of the fuel.
• Critical intake pressure method: Any diesel engine can be used for this purpose.
However, it is preferred to have one cylinder (DIN 51773).
In this engine, the injection start, the pressure increase in the combustion chamber and the crank angles are It is necessary to record
. For this purpose, inductive transmitter, piezo-quartz transmitter, photo-transmitter and oscillograph are used.
can be used. The engine is rotated at a constant speed above half its maximum speed. partial
It is more important that the amount of fuel injected remains constant when operating at load. TG = 20° in the experiment
KMA constant value is selected and the target is for the pressure rise (ignition) to be exactly at TDC.
is taken (Karakus, 2000).
For this purpose, PA = 20° KMA should be set. Then the fuel to be tested is delivered to the engine and
The air is throttled with a butterfly in the suction nozzle. This process starts ignition at TDC.
. In this critical situation, the vacuum value in the intake manifold is determined.
is done. With the help of the reference fuel giving 20° KMA TG under the same conditions, SS can be used as in the previous method. It can be found like
.
DUAL FUEL ENGINES
Dual fuel diesel engines are defined as engines that run on gas-diesel fuel or only diesel fuel.
is defined. In a dual fuel engine, gas is mixed with air and taken into the cylinder.
The mixture is then compressed and towards the end of the compression period the diesel fuel is released from the injector.
The work is carried out by spraying.
The characteristics of dual-fuel combustion are different from single-fuel combustion. diesel fuel vapor
Since it is sprayed into the cylinder, it forms its own mixture after mixing with air compressed at high temperature.
It quickly dissolves in droplets that adhere to it and evaporate. In dual fuel operation
combustion tends to be conversely controlled by flame spread. Pilot powered by diesel fuel
the energy is greater than the energy provided by a spark plug. This is enough for the engine It can be applied to a dual-fuel engine to operate at a lean air-fuel ratio of
.
The energy of the pilot spray beam is 102-104 times the energy provided by the spark plug. Thus
Initial ignition is also guaranteed at values of the excess air coefficient of 1.4-2. From now on
More importantly, by creating a spray beam suitable for the room shape with pilot spraying,
With the help of the air movement created in the cylinder, combustion is carried out downwards at every point in the room.
is ensured to start at the same time. In this way, at compression ratios of 16-17
Knock-free combustion can be achieved. Original injector of pilot injection diesel engine If done with
, the orifice of this injector is relatively large for pilot injection flow rates.
remains, the quality of the beam will be poor (beam depth is small, droplet diameters are large).
The gas-air mixture, which is distributed quite homogeneously in the combustion chamber, is completely It cannot be burned as
.
In this case, there is an increase in harmful exhaust gas emissions and fuel consumption.
However, the biggest advantage of using the original spray injector is the engine operation.
It allows switching to natural gas or diesel fuel.
Smaller bore injector with hole diameter adapted to the fuel flow rate of the pilot injection
is used, there will be no problem in terms of combustion efficiency and emissions. In this case fuel
consumption and emission values are approximately at the level obtained with normal diesel fuel, sometimes
goes further down.
When it is desired to inject natural gas into the cylinder,
changes need to be made. By making changes to the engine cylinder head and fuel
. compression process
Towards the end, gaseous fuel is injected into the cylinder through a separate injector. here
The injection advance of the pilot fuel injected into the cylinder at the end of compression is important.
This advance must be reduced, otherwise there will be a decrease in power. pilot fuel With the help of
, ignition is ensured in the cylinder at the end of compression. In this system, the cylinder
Two injection valves are required in the head, one for gas and the other for pilot fuel.
is heard. In order for the engine to operate at the same power as normal, either high
pressurized gas injection or the use of diesel fuel together with gaseous fuel
is required.
Use of Natural Gas in Otto Engines
Natural gas can be used in petrol engines without much modification. petrol engines
It can be operated with petrol or natural gas when desired. natural gas petrol
While it is possible to use very small amounts in engines, it can also be used as the only fuel. It is possible to use
. In both cases, pollution in exhaust emissions decreases,
There are significant reductions, especially in the amount of carbon monoxide. Engine runs on both fuels It can work with the
cycle. The electric ignition system is used as is. natural gas petrol If used in
engines, pilot fuel is used to ignite the mixture with the ignition system.
is not required since the situation exists.
Addition of a gas/air carburetor to a petrol engine and ensuring that the ignition system is suitable for the engine By rearranging it as
, the engine can be used as a natural gas engine.
is possible. Apart from these, the necessary equipment for storing natural gas and transporting it from the warehouse to the engine
The system must be equipped with elements such as a pressure regulator and safety valve.
After the pressure of natural gas stored at high pressure is reduced in regulators, the gas
mixture with air is provided in the carburetor. The mixture of gas carburettors is homogeneous
and at the desired fuel/air ratio, the flow should be adjusted in a way that does not reduce engine power.
Keeping the resistance as low as possible ensures that the engine is safe under all operating conditions.
operation, preparing all cylinders at the same fuel/air ratio, engine power
The flow resistance should be as low as possible so as not to reduce the It operates safely under
conditions and sends the same fuel/air mixture to all cylinders.
and preparing the mixture to keep pollutant exhaust emissions at a low level.
is required.
In petrol engines, as in diesel engines, the venturi carburetor has an orifice (hole).
carburetor, vortex carburetor and variable limitation carburetor are used.
Natural gas is suitable for engines operating according to the Otto principle due to its high octane number.
It is a suitable fuel. However, the energy density per unit mass is higher than that of petrol.
Although it is higher, the energy density of the mixture at stoichiometric ratios is higher than that of petrol.
is low. For this reason, the power to be obtained from the same engine decreases when natural gas is used.
In addition, the low burning rate creates negative effects in terms of thermal efficiency.
However, the flammability limit of natural gas is lower than that of petrol as we move towards poorer mixtures.
Its width causes the thermal efficiency to be higher under these conditions.
The figure is lower than petrol. For this reason, the power to be obtained from the same engine is natural gas
It drops when used. In addition, the low burning rate is important in terms of thermal efficiency.
creates negative effects. However, the flammability limit of natural gas moves towards poor mixtures.
As you go, it is wider than petrol, which causes the thermal efficiency to be higher under these conditions.
causes.
variation of thermal efficiency as a function of excess air coefficient
can be seen. On the other hand, the maximum torque during natural gas usage In order to achieve
, the ignition advance must be increased.
On the other hand, in order to provide maximum torque when using natural gas, ignition
The advance payment needs to be increased. This difference occurs at poorer values of the excess air coefficient.
becomes even more evident.
66
The compression ratios of diesel engines are quite high, such as 18:1, while natural gas In
engines, this value needs to be reduced further. Within this or smaller
pistons are used, or the pistons are cut to the desired 12:1 level by machining.
compression ratios can be achieved. Methane is another element that makes up natural gas.
Since it is less reactive than hydrocarbons, it requires higher energy for ignition.
is needed. For this, a spark plug that gives higher energy must be used.

Category: news atiker brc brc prices brc autogas installation wholehearted engineering candan otogaz italian brc lavato lpg lpg conversion lpg autogas milan mimgas autogas autogas installation sequential system

Advantages of Autogas LPG as Motor Fuel
•Autogas is economical, the main target is fuel saving..

•Autogas provides ease of starting in cold weather.

This article is from the Candan Mühendislik knowledge archive. Prices, offers and procedures reflect the date of publication. Please contact our team for current information.