**Natural Gas Vehicles: Names and Working Principles of Three Power Forms** Natural gas vehicles (NGVs) are becoming increasingly popular due to their environmental advantages and cost-efficiency. There are three primary power forms of NGVs: Compressed Natural Gas (CNG), Liquid Natural Gas (LNG), and Adsorbed Natural Gas (ANG). Each of these forms has a unique name and working principle. 1. **Compressed Natural Gas (CNG)**: * **Name**: Compressed Natural Gas is a gas that is stored under high pressure (typically 20-25 MPa) in tanks for use as a fuel in vehicles. * **Working Principle**: The CNG is first compressed and then stored in tanks located on the vehicle. When the engine starts, the CNG is released from the tank through a regulator to lower its pressure. It then enters a mixer where it combines with air. This mixture is regulated by sensors and computers to ensure optimal combustion. The mixture is then fed into the cylinders where it is ignited by the spark plugs, causing the pistons to move, thus generating power. 2. **Liquid Natural Gas (LNG)**: * **Name**: Liquid Natural Gas is natural gas that has been cooled to a temperature of around -162°C, which converts it into a liquid form for easier storage and transportation. * **Working Principle**: LNG is stored in cryogenic tanks on the vehicle. Before being used as a fuel, it is warmed and converted back to a gaseous state. The subsequent process is similar to CNG, with the LNG gas being mixed with air, regulated, and then ignited in the engine cylinders. 3. **Adsorbed Natural Gas (ANG)**: * **Name**: Adsorbed Natural Gas is a storage technique where natural gas is adsorbed onto a porous material, such as activated carbon, at high pressure. This allows for a higher density of natural gas to be stored compared to traditional methods. * **Working Principle**: ANG systems typically have a storage tank filled with an adsorbent material. Natural gas is then pressurized and adsorbed onto the material. When needed, the pressure is reduced, allowing the gas to desorb and be used as fuel. The ANG gas is then mixed with air, regulated, and combusted in the engine cylinders. Each of these NGV power forms offers its own advantages and considerations, making them suitable for different applications and environments.
