What is CNG?
CNG stands for Compressed Natural Gas. It is normally a gas and not fuel and is a mixer of hydrocarbons mainly Methane. For use in Automobiles as fuel, it is compressed to a Pressure of 200-250 kg/cm2 to enhance the vehicle on- board storage capacity.
Can LPG be filled on CNG vehicle cylinders?
No. Under no circumstances LPG is used in CNG vehicles nor CNG be filled in LPG vehicles as both gases have different properties and operates under different pressures.
What is CNG cylinder and its life?
CNG cylinders are manufactured from high strength alloy steel and are seamless to withstand high pressure. Each CNG cylinders are approved by Petroleum and Explosive Safety Organisation and Bureau of Indian Standards. Every CNG cylinder is retested at and interval of 3 years at PESO approved testing station. Life of CNG cylinder is 20 years. It is available is different sizes and capacities as per the requirement. CNG is filled at a pressure of 200-220 kg/cm2 at filling station.
Can a car, fitted with CNG conversion kit, run on Petrol after its CNG gets over?
Yes, after conversion to CNG the vehicle can run on petrol whenever desired simply by changing switch position from CNG to Petrol. It is advisable to carryout changeover operation in standby mode of vehicle.
Is CNG vehicle as powerful as normal petrol vehicle?
The average motorist doesn''t notice a difference between fuels but usually there will be variation – sometimes natural gas vehicle will be more powerful and sometimes less depends on the condition of engine and the driving habits.
Are maintenance needs different for CNG?
CNG engine works essentially the same way as petrol engine. Most engine service requirement are similar to petrol engine like air filter cleaning and spark plugs replacement on a regular interval for better performance and driving comforts.
Does CNG Kit requires servicing and maintenance?
CNG kit (vaporiser) is safe, simple and robust in its design. It gives years of trouble free operation as it doesn''t require frequent servicing. In case of low pick up or mileage which may occur due to impurities accommodate in the vaporiser, which needs to be cleaned and the diaphragms to be changed to get a better performance and mileage.
How much will be the saving after conversion of vehicle to CNG?
Looking to the price difference of Petrol and CNG, the approximate saving shall be in the range of 60 % to 75 %. In other words, if the running cost per km in petrol is Rs.7.00, then in CNG it shall be in the range of Rs.1.75-Rs.2.25 per km.
How does CNG usage benefit the country?
CNG emits less carbon dioxide and other pollutants as compared to liquid fuels. Thus, CNG contributes in lowering air pollution than the other conventional fuels. Secondly, as large resources of natural gas is available in country thus reducing import bill of crude oil which is helping economy of the country.
What Is Difference Between Conventional & Sequential CNG Kit ?
Conventional CNG Kit
In conventional kit the CNG Reducer supplies the CNG Gas to the Engine through a locally made Air Gas Mixture which is not supplied by the CNG Kit Manufacturer; it is then fitted on the Air Intake (Inlet Manifold) of the Engine. The CNG Gas and Air mixture is sucked by the Engine which travels through the manifold and reaches inside the engine, according to its firing order.
As there is no computer control over the flow of CNG gas into car’s engine in a conventional CNG Kit, an even flow of CNG gas mixture now enters into the combustion chamber and burns with the help of the Sparks generated by the Spark plugs fitted in the Cylinder Head.
With the improvement in Engine Technologies (BS-III) little improvement in the CNG Kit technology was achieved with the introduction of Lambda Controlled System (LCS) or Close loop System & Timing Advancers(TA). A little control of the Gas flow and poor pick up can be made up with this LCS and TA that are connected with the MAP Sensor, TPS & Oxygen Sensor (Lambda sensor) fitted in the Engine & Exhaust Manifold (Silencer) of the Car.
Due to the slight improvement in car’s pick-up with CNG Kits fitted with LCS and TA; more users started to switch to CNG from petrol and the use of A/C on CNG was more effective without compromising performance and engine’s life.
Sequential CNG Kit
With the further advancements in technology and need for better performance from CNG Kits users, Sequential CNG Kits were introduced to match the performance of EFI or MPFI car by delivering computer controlled CNG gas injection through nozzles (similar to injectors in petrol cars) which is matched to the engine’s original computer for better optimization, increased performance and power & even better fuel efficiency.
The Difference between a Sequential CNG Kit & Conventional CNG Kit is as same that of a Petrol Carburetor Car and MPFI Car. In MPFI cars the delivery and quantity of fuel is controlled by the Petrol Injectors installed in the Cylinder Head Assy.. The Injectors are connected with the Electronic Control Module (ECM) of the Car which takes signals from other sensors fitted and helps in improving the pick and mileage of the cars and helps in reduction of pollutants levels also.
A Sequential CNG Kit works the same way. It has a separate CNG gas ECM and multiple CNG Gas Injectors to control the flow and quantity of the CNG gas. These are installed just next to the petrol injectors on the engine cylinder head. CNG gas is pumped inside the engine’s combustion chamber which results in better fuel combustion resulting in better pickup, increased mileage, low engine load and no dust entry into the engine when compared to air-gas mixture installed in a conventional CNG Kit system. No modifications are required in the air intake system when using a Sequential CNG Kit system than compared to a Conventional CNG Kit system.
The size of the CNG reducer fitted is smaller than conventional CNG kit and supplies CNG directly to the CNG Injector rail which takes lesser engine space. The CNG Gas ECM is connected with the Engine ECM though specially Designed Waterproof Wiring which send the signals to the CNG Gas Injectors for gas injection.
The ECM receives signals from the MAP sensor fitted in the Car for proper quantity of the Gas to be released to the Injectors. The quantity of the CNG Gas is also monitored by the Vacuum Pipes installed. If there is any leakage in the Vacuum system the Gas Supply to the Engine is cut and it is automatically shifted to Petrol Mode with a buzzer sound installed in the Fuel Change over switch.
The system has a customized software design, which allows selection of Fuel change, Time, Temperature and Changeover RPM also. It comes with a very compact sized fuel selection switch with built in buzzer alarm which can be fitted easily anywhere. If the CNG GAS goes off while driving, the car automatically comes on Petrol with a buzzer sound. The user cannot judge the difference between the performance in Petrol / CNG and is useful for cars with Complex Engine Technologies or latest Engine Technologies.
The fully automatic and self-calibrated GAS ECM does not require tune ups on a regular basis which save maintenance costs. Even in case of problems the repairing is done through electronically using the software which automatically detects and fixes any faults in the system and takes much lesser time than manual calibration. Electronic maintenance reduces chances of human error and save a lot of time. Even when you take the car for regular service or maintenance, there is no need for the setting does not changes.