Liquefied natural gas (LNG) is a clean energy source recognized in the world today. It has high calorific value, full combustion, low price, good transportation economy, and safety, and is welcomed by the majority of users. Currently, LNG vehicles fueled by LNG have been put into operation. As a key part of the LNG vehicle fuel system, the LNG vehicle cylinder has been widely concerned.

LNG vehicle cylinder

Detailed descriptions of LNG Vehicle Cylinder

LNG Vehicle cylinders are designed as low-temperature insulated pressure vessels with a double-layer (vacuum) structure. The inner tank is used to store low-temperature liquid liquefied natural gas, and the outer wall is wrapped with multiple layers of insulation material, which has super thermal insulation performance. At the same time, the interlayer (the space between the two layers of containers) is pumped into a high vacuum to form a good thermal insulation system. The actual housing and support system can withstand the relevant external forces generated by the vehicle when it is running.

The inner tank is designed with two safety valves to protect against overpressure. In the case of overpressure, the first opening is the main relief valve (opening pressure 1.59Mpa,230psi), which dissipates the pressure rise caused by the normal heat loss of the insulation layer and support, or the pressure rise caused by the accelerated heat leakage after the vacuum is destroyed and in the case of misfire. The secondary relief valve (opening pressure 2.41Mpa,350psi) has a higher pressure set point than the primary relief valve, and the secondary relief valve is activated when the primary relief valve fails or is blocked.

The protection of the enclosure under internal overpressure conditions is achieved by a ring-shaped evacuation plug. In the event of leakage of the liner (resulting in excessive jacket pressure), the evacuation plug will open pressure relief when the pressure reaches 0.1~0.2Mpa. In case of leakage of the evacuation, the plug will lead to vacuum destruction, then the shell can be found to "sweat" (large area of water droplets) or even frost phenomenon. Of course, frosting or condensation at the end of the pipe connected to the cylinder is normal.

All pipelines and valves are set at one end of the cylinder and protected with a protective ring or cover.

Safety precautions and emergency measures

1. The operators must fully understand the performance of the cylinder, the technological process of the filling platform, and the function of various valves and instruments on the equipment, master the operation rules and safety management system, understand the performance and hazards of LNG, and receive technical and safety training.

2. During the filling operation, the operator shall not leave the site, operate in strict accordance with the operation rules, observe the pressure changes, and avoid the danger caused by too fast pressure increase and too fast filling.

3. When the valve and connection on the equipment are frozen, the flow is controlled. It is strictly forbidden to bake with an open flame or hot objects, and it is not allowed to hit objects.

4. Operators must wear protective gloves, protective clothing, and antifreeze shoes, to prevent frostbite (to wear a mask, respirator, etc.).

5. The operators in the station must be proficient in the use of fire extinguishers.

Contact Cimc Enric for LNG Vehicle Cylinder details!