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Alternative Fuels for Transportation
As mentioned above, LPG, compressed natural gas (CNG), hydrogen, and
many other alternative fuels fall within the first category. As for the second
category, the use of the variable stroke length, variable compression ratio,
variable valve timing, turbocharger, supercharger, and so on have been
tested and used with gasoline. The use of the modified engine design with
another fuel constitutes the third category.
Each one aims at introducing improvement in one direction or parameter.
To assist these experimental researches, several theoretical studies investigated the performance of LPG as fuel for SI engines. A quasi-dimensional SI
engine cycle model has been developed to predict the cycle performance and
exhaust emissions of an automotive engine using gasoline and LPG fuels.
The model also studies the mechanism of combustion and emission formation of both fuels (i.e., gasoline and LPG). Many simulation models are now
available to be used for studying the behavior of LPG as a SI engine fuel.
Each one concentrates on certain phenomena.
As for the use of variable stroke length mechanisms concerned, a simulation model for the engine was developed with the different power and
efficiency characteristics being computed and presented for different stroke
lengths and the corresponding compression ratios. Effect of variable stroke
mechanism on LPG engine performance has been theoretically investigated
and it has been shown that the engine performance improves with this new
design (Ozcan and Yamin 2008)
7.5 Engine Tests
LPG is commonly used in both types of engines. The gasoline engines can
be equipped with retrofit devices that enable them to run on LPG as well as
gasoline. The gasoline engines can be converted to dedicated LPG fueled
engines. In both cases, vehicles have similar characteristics in terms of fuel
system and storage systems. In diesel engines dual fuel mode operation, LPG
is inducted into the engine as a mixture of LPG + air.
7.5.1 LPg Conversion Systems
Several methods were tested to improve the performance of LPG powered,
four stroke SI engines. The addition of coconut oil, gasoline, ethanol, dimethyl ether, and many other supplements to LPG were studied. Each of these
supplements showed a certain percentage of improvement. However, the
idea of supplementing fuel was not favorable since it is sometimes accompanied with additional accessories and equipments for the additional fuel. LPG
conversion systems are classified in three main groups, as follows:
Alternative Fuels for Transportation
As mentioned above, LPG, compressed natural gas (CNG), hydrogen, and
many other alternative fuels fall within the first category. As for the second
category, the use of the variable stroke length, variable compression ratio,
variable valve timing, turbocharger, supercharger, and so on have been
tested and used with gasoline. The use of the modified engine design with
another fuel constitutes the third category.
Each one aims at introducing improvement in one direction or parameter.
To assist these experimental researches, several theoretical studies investigated the performance of LPG as fuel for SI engines. A quasi-dimensional SI
engine cycle model has been developed to predict the cycle performance and
exhaust emissions of an automotive engine using gasoline and LPG fuels.
The model also studies the mechanism of combustion and emission formation of both fuels (i.e., gasoline and LPG). Many simulation models are now
available to be used for studying the behavior of LPG as a SI engine fuel.
Each one concentrates on certain phenomena.
As for the use of variable stroke length mechanisms concerned, a simulation model for the engine was developed with the different power and
efficiency characteristics being computed and presented for different stroke
lengths and the corresponding compression ratios. Effect of variable stroke
mechanism on LPG engine performance has been theoretically investigated
and it has been shown that the engine performance improves with this new
design (Ozcan and Yamin 2008)
7.5 Engine Tests
LPG is commonly used in both types of engines. The gasoline engines can
be equipped with retrofit devices that enable them to run on LPG as well as
gasoline. The gasoline engines can be converted to dedicated LPG fueled
engines. In both cases, vehicles have similar characteristics in terms of fuel
system and storage systems. In diesel engines dual fuel mode operation, LPG
is inducted into the engine as a mixture of LPG + air.
7.5.1 LPg Conversion Systems
Several methods were tested to improve the performance of LPG powered,
four stroke SI engines. The addition of coconut oil, gasoline, ethanol, dimethyl ether, and many other supplements to LPG were studied. Each of these
supplements showed a certain percentage of improvement. However, the
idea of supplementing fuel was not favorable since it is sometimes accompanied with additional accessories and equipments for the additional fuel. LPG
conversion systems are classified in three main groups, as follows: