What is advantage And Disadvantage of CNG ?

What is advantage And Disadvantage of CNG ?

Advantages of CNG :

1. High octane number makes it a very good S.I. engine fuel.
2. Low engine emissions. Less aldehydes than with methanols.
3. It is cheap (It costs about 25 to 50% less than gasoline and more than 50% less than other alternative fuels, such as methanol and ethanol.
4. It is engine friendly.
5. It is safe in operation.
6. Fuel fairly abundant world-wide. Natural gas is the second most abundant fuel available in India after coal.
7. Easy to tap.
8. It is odourless.
9. It is clean.

Disadvantages of CNG :

1. Low energy density resulting in low engine performance.
2. Low engine volumetric efficiency because it is a gaseous fuel.
3. Need for large pressurised fuel storage tank.
4. Inconsistent fuel properties.
5. Refueling is a slow process.
6. The storage cylinder takes a lot of space as the gas once filled has to travel at least of 400 km. But now a days there are byfuel and duel-fuel engines which can run on CNG and other fuel.

What is Advantages of using biogas as fuel in C.I. engine?

Advantages of using biogas as fuel in C.I. engine

The biogas can be used in C.I. engine as a duel fuel and improves engine performance.
The following are the advantages of using biogas as fuel in C.I. engine :

1. A uniform gas-air mixture is available in multi-cylinder engine at all times.
2. Due to clean operation of the engine there is virtually no CO-emission in exhaust.
3. When biogas is used as a fuel, NOx emissions are reduced by about 60 per cent.
4. Soot is virtually eliminated and exhaust is found to have less pungent odour than that obtained while operating the engine with diesel oil.

What is advantage And Disadvantage of Air Injection ?

Air Injection:

In this method of fuel injection air is compressed in the compressor to a very high pressure (much higher than developed in the engine cylinder at the end of the compression stroke) and then injected through the fuel nozzle into the engine cylinder. The rate of fuel admission can be controlled by varying the pressure of injection air. Storage air bottles which are kept charged by an air compressor (driven by the engine) supply the high pressure air.

Advantages :

1. It provides better automisation and distribution of fuel.
2. As the combustion is more complete, the b.m.e.p. is higher than with other types of injection systems.
3. Inferior fuels can be used.

Disadvantages :

This method is not-used now-a-days due to the following reasons/disadvantages :

1. It requires a high pressure multi-stage compression. The large number of parts, the intercooler etc. make the system complicated and expensive.
2. A separate mechanical linkage is required to time the operation of fuel valve.
3. Due to the compression and the linkage the bulk of the engine increases.
4. This also results in reduced B.P. due to power loss in operating the compression and linkage.
5. The fuel in the combustion chamber burns very near to injection nozzle which many times leads to overheating and burning of valve and its seat.
6. The fuel valve sealing requires considerable skill.
7. In case of sticking of fuel valve the system becomes quite dangerous due to the presence of high pressure air.

What is advantage and disadvantage solid or airless injection ?

Advantages : solid or airless injection

1. The system arrangement is simple and less maintenance cost.
2. Only one pump is sufficient for multi-cylinder engine.
3. It fulfills the requirements of either the constant load with variable speed or constant speed with variable load.
4. Variation in pump supply pressure will affect the cylinders uniformly.

Disadvantages :

1. There is a tendency to develop leaks in the injection valve.
2. Very accurate design and workmanship are required.

What is advantage And Disadvantage of Battery or coil ignition system ?

Advantages : of Battery or coil ignition system

1. It offers better sparks at low speeds, starting and for cranking purposes.
2. The initial cost of the system is low.
3. It is a reliable system and periodical maintenance required is negligible except for battery.
4. Items requiring attention can be easily located in more accessible position than those of magnetos.
5. The high speed engine drive is usually simpler than magneto drive.
6. Adjustment of spark timing has no deterimental effect over the complete ignition timing range.

Disadvantages :

1. With the increasing speed, sparking voltage drops.
2. Battery, the only unreliable component of the system needs regular attention. In case battery runs down, the engine cannot be started as induction coil fails to operate.
3. Because of battery, bulk of the system is high.

What is advantage of 12-V ignition system over 6-V system ?

Advantages of 12-V ignition system over 6-V system :

The following are the advantages of 12-V ignition system over 6-V system :

1. Considerably higher voltages are obtainable.
2. For transmitting equal power with excessive voltage drop, the cable in a 6-V system needs theoretically to be four times the thickness of 12-V system, cables.
3. Improved starting.
4. Adequate electric power to supply the increasing number of electrical accessories used.

What is advantage and disadvantage of Magneto ignition system ?

Advantages : Magneto ignition system

1. The system is more reliable as there is no battery or connecting cable.
2. The system is more suitable for medium and very high speed engines.
3. With use of cobalt steel and nickel-aluminium magnet metals very light and compact units can be made which require very little room.
4. With recent development this system has become fairly reliable.

Disadvantages :

1. At low speeds and during cranking the voltage is very low. This has been overcome by suitable modifications in the circuit.
2. Adjustment of the spark timing i.e. advance or retard, has deterimental effect upon the spark voltage or energy.
3. The powerful sparks at high engine speeds cause burning of the electrodes.

What is advantage of electronic fuel ignition ?

Advantages : of electronic fuel ignition

The advantages of TCI system are :

1. Reduced wear of the components.
2. No problem faced in burning lean mixtures.
3. Reduced maintenance of the ignition system.
4. Increased reliability.
5. Increased spark plug life.