Sun. Jun 20th, 2021

City gas distribution

Transporting future fuel

#74 Natural Gas Vehicle (NGVs)

4 min read
  1. The performance of a NGV can be attributed to the fill ratio & driving range.
  2. Fill ratio is defined as a mass of charged gas after refueling divided by the mass which the cylinder could hold at the rating condition (300 K & 20 MPa for CNG)
  3. The driving range of NCVs is generally less than that of comparable conventional (gasoline based) vehicles because of the lower energy density of natural gas. Driving range is the ratio of mass flow rate (at the end of filling) to the product of fuel density & vehicle cylinder volume. For eg. A car with a tank of 50 litres capacity will run for 1000 km without refueling. This means that the driving range of car would be 20 km per litre.
  1. There are three basic types of NCVs i.e. Dedicated, Bi-fuel & Dual fuel.
  2. The Dedicated type NGV is designed to run only on natural gas, whereas the Bi-fuel type uses two separate fueling systems that enable them to run on either natural gas or gasoline. The dual-fuel type is limited to heavy-duty applications. They have fuel systems that run on natural gas & use diesel fuel for ignition assistance.
  3. Generally dedicated NGVs offer a better performance & have lower emissions than bi-fuel vehicles. Moreover, dedicated NGVs only have one fuel tank, so they aren’t as heavy as bi-fuel NGVs & offer more cargo capacity.
  4. NGVs offer various advantages over conventional vehicles, the most important being the reduction in emission of environmentally harmful gases.
  5. NGVs offer around 93% reduction in CO, 33% reduction in NOx & 50% reduction in reactive hydrocarbons.
  6. Natural gas cost lower than gasoline. On an average, natural gas costs one-third less than gasoline at the pump.
  7. NGVs also offer a noise reduction of as much as 50%.
  8. They have lower maintenance costs as natural gas burns cleanly which in turn results in less wear & tear on the engine & extends the time between tune-ups & oil change.
  9. The major disadvantage that NGVs have as compared to gasoline powered vehicles is the limited driving range. Moreover, NGVs are less spacious, as they have to accommodate the fuel storage cylinders.

Working of CNG Engine:

  1. CNG engine use a fuel tank which is mounted on the car, & is usually placed in the trunk.
  2. The gas is stored in an integrated storage system in which composite cylinders are contained within a fiber glass shell & impact-absorbing foam to protect them.
  3. CNG is filled in the tanks & is pulled through a series of highly pressurized lines until it reaches the regulator. The pressure of the gas is decreased (inside a regulator assembly) until it matches the amount needed by the fuel injection system of the car’s engine.
  4. When the gas reaches an acceptable pressure, a valve opens to allow the gas to move into the fuel injection system & from there into the engine.
  5. The fuel-air engine is ignited by a spark plug & the expanding gases produce rotational forces that propel the vehicle.

Leave a Reply

Your email address will not be published. Required fields are marked *

Copyright © Citygasdistribution |All rights reserved |