Self-Study Programme 427 BiFuel LPG drive.pdf

(2587 KB) Pobierz
Service Training
Self-study Programme 427
The BiFuel LPG Drive
Design and Function
For the first time, Volkswagen is offering the Golf
2009 with the 1.6l 75kW MPI engine and LPG drive
straight from the factory. LPG is also known as liquid
gas or autogas. LPG stands for “Liquefied Petroleum
Gas”. All components that are required for gas
operation are fitted on the production line at
Volkswagen.
LPG has been in use for decades and is currently the
most popular alternative fuel across the world. It is
made from a mixture of propane, butane and
additives. It burns cleanly and is thus among the latest
of energy fuels. In many cities, more and more
vehicles are being run on LPG due to rising
environmental awareness.
Compared with other fuels, LPG produces
considerably fewer exhaust emissions. The same
applies to carbon dioxide emissions (CO
2
), which are
associated with climate change. On the whole, the
exhaust emissions caused by LPG vehicles are among
the lowest that can currently be achieved with
combustion engines. LPG fuel is virtually sulphur-free
and its combustion produces almost no soot.
Hazardous substances like carbon monoxide (CO),
hydrocarbons (HC), nitrogen oxide (NO
X
) and other
health- and environment-harming exhaust gas
components are considerably less.
S423_889
The self-study programme portrays the
design and function of new
developments.
The contents will not be updated.
For current testing, adjustment and repair
instructions, refer to the relevant service literature.
Important
Note
2
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
LPG Drive Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
LPG System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Engine Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Functional Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Test Yourself . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3
Introduction
The raw material LPG
LPG (Liquefied Petroleum Gas) is a liquid gas that is
used to power combustion engines. It is just as
suitable for use as a vehicle fuel like petrol, diesel and
natural gas.
LPG is a waste product from natural gas and crude oil
refining. It is characterised by a high degree of purity.
This prevents “aging” so LPG can practically be stored
indefinitely.
The gas is liquefied under a relatively low excess
pressure of approx. 6-10bar and stored in various
types of compressed gas container. In this way, it is
possible to transport and store large quantities of fuel
in a small space. LPG can be used in any location.
Compared with petrol, LPG has a very high anti-knock
index and, depending on the mixture ratio of propane
and butane has an octane number of approx. 105 to
115 RON.
The quality requirements for LPG have been
standardised across Europe in DIN EN 589 so one
will have no problems when driving abroad.
Main components
In principle, LPG is a mixture of hydrocarbons. It is
mainly made from a mixture of propane and butane.
LPG also contains an odorant. This is added as a
precaution since pure LPG is odourless and
colourless.
Propane is lighter and liquifies at lower temperatures
than butane. Butane, however, has a higher energy
proportion per volume unit. The mixing ratio is,
dependent on the market, in summer 50:50 (in
percentage propane/butane) and in winter 85:15.
Deviations from the mixing ratio are possible
depending on the supplier. Since propane delivers
less energy than butane, the consumption of LPG is
slightly higher in winter.
4
Properties of the main components
Propane C
3
H
8
Butane C
4
H
10
S427_010
S427_008
Formula:
CH
3
-CH
2
-CH
3
Boiling point:
-42.1 °C
Ignition temperature:
470°C
(petrol 240°C)
Properties:
- Colourless and odourless gas
- Heavier than air
- Extremely flammable gas
Use as:
- Combustion gas for heating and lighting purposes
- Propellant in sprays
- Balloon gas
- Refrigerant in industry
Production:
Waste product from crude oil refining
H = hydrogen, C = carbon
Formula:
CH
3
-CH
2
-CH
2
-CH
3
Boiling point:
-0.5°C
Ignition temperature:
365°C
(petrol 240°C)
Properties:
- Colourless and odourless gas
- Heavier than air
- Extremely flammable gas
Use as:
- Combustion gas in laboratories and households
- Low-temperature solvent and extraction agent
- Propellant in sprays
- Refrigerant in fridges
(not for freezing)
Production:
Waste product from crude oil refining
The following names for LPG are common across Europe:
-
-
-
-
Autogas
GPL
GLP
GLP
= Germany
= France “Gas de pétrole liquéfie”, also called GPL-C (GPL-carburant)
= Italy “Gas Liquido Propano”
= Spain “Gases Licuados del Petróleo” (GPL Automoción)
5

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin