Hydraulic pressure-relieving safety system for LNG tank car

Abstract

The invention discloses a hydraulic pressure-relieving safety system for a LNG tank car. The system comprises a safety valve, a pressure transmitter, a micro-computer system and an emergency cut-off valve; the safety valve is arranged on a blow-down pipe of the tank car and is connected with the micro-computer system; the safety valve is controlled to automatically open or close by an automatic control system of the micro-computer system. The device disclosed by the invention is simple; the operation is simple and convenient; the pressure value and the alarm value of each monitoring point can be directly observed on a display; an audio alarm is sent, the emergency cut-off valve of a self-pressurizing system pipeline is automatically opened, the gasifying pressurization is stopped, and meanwhile, the safety valve is automatically controlled to open, the gas in the tank car can be locally emptied, the pressure of the tank car is reduced and the safety of the tank car main body is guaranteed once the pressure of the self-pressurizing system is ultrahigh, the pressure in the LNG tank car is ultrahigh and the pressure value reaches or exceeds a present threshold value because a liquid discharging system is in fault or is not started.

Description

technical field [0001] The invention relates to the technical field of safety in the liquid unloading production process of a liquefied natural gas gasification station, in particular to an LNG tank car unloading pressure safety system. Background technique [0002] With the advancement of energy saving and emission reduction, air pollution and smog control, the utilization of natural gas in cities in my country has increased sharply. As a liquid product with high energy density, liquefied natural gas is easy to transport, and is especially suitable for natural gas far away from natural gas production sites without pipeline transportation. However, due to the flammability and explosion hazard of natural gas and the low temperature of liquefied natural gas, once the liquefied natural gas pipeline leaks, the low-temperature liquefied natural gas will gasify rapidly, and the volume will expand by about 600 times, which may cause fire and explosion accidents. It will bring great h...

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Problems solved by technology

[0002] With the advancement of energy saving and emission reduction, air pollution and smog control, the utilization of natural gas in cities in my country has increased sharply. As a liquid product with high energy density, liquefied natural gas is easy to transport, and is especially suitable for natural gas far away from natural gas production sites without pipeline transportation. However, due to the flammability and explosion hazard of natural gas and the low temperature of liquefied natural gas, once the liquefied natural gas pipeline leaks, the low-temperature liquefied natural gas will gasify rapidly, and the volume will expand by about 600 times, which may cause fire and explosion accidents. Great harm to the life and property safety of residents around the gasification station

[0003] There have been many accidents in many gasification stations in China, all of which were caused by forgetting to open the valve of the unloading pipeline during the unloading process of the LNG tanker, and the self-pressurization system continued to gasify, and the pressure inside the tanker tank was too high, resulting in unloading. The liquid hose collapsed and the liquefied natural gas leaked, seriously endangering the safety of the gasification station

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