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Most developed countries use indigenous fuels for powering their
transport sector, however developing countries have to import
transport fuels/ petroleum to produce transport fuels and they
struggle for fuel production from domestic resources. Being a
developing country, India is focusing on reduction of fuel import
bill by introducing indigenous transport fuels such as variety of
biofuels. High ash content coal is available in India, which cannot
be used for electricity generation, however this can be used for
methanol production using gasification route that can be used to
power the Indian transport sector. Although methanol production is
already done in India, but current production capacity cannot fulfil
the huge demand of the transport sector currently. Currently, India
is preparing a road map for large scale adaptation of M15 also, has
a vision to for M85 in the existing spark ignition (SI) engines,
which has several challenges. Methanol has great potential to be
utilized in SI engines. Two-wheelers population in Indian road
transport sector is more than 70% in terms of number of vehicles
registered. Carburetor is used to induct the fuel in these small
capacity (100-150 cc) SI engines. Research is focused on the
adaption methanol utilization in existing mechanical carburetor
assisted two-wheelers and electronic carburetors. A carburetor is
designed to perform three main tasks namely fuel atomization, fuel
vaporization, and fuel-air mixing. Following factors are important
for these tasks: (i) Time available for fuel-air mixing; (ii)
Temperature of the incoming air; (iii) Boiling range of fuel; and
(iv) Length of manifold used to connect a carburetor and the test
engine. Primarily, carburetor prepares three types of mixtures: rich
mixture for idling condition, lean mixture for superior fuel
economy, and stoichiometric mixture for achieving complete
combustion. The carburetor has to supply the required air-fuel ratio
at steady-state and transient conditions of the vehicle.
Steady-state means vehicle can run at a constant speed and achieve
constant power output from the engine. Transient condition means
speed and load of the vehicle varies continuously, thereby getting
variable power from the engine. Existing carburetors are calibrated
for the pure gasoline so, it will be calibrated for the M15 and M85
fuels in steady state conditions. Transient cycles such as WMTC and
IDC will be performed to check the emissions. Also, spray
characterisation of the fuel using calibrated jets will be performed
and compared with the baseline fuel spray characteristics to
understand the effects of calibration on fuels. |
