Overload processing method for LNG tank car

Abstract

The invention relates to an overload processing method for an LNG tank car. The overload processing method comprises the following steps: (1) connecting an empty tank car of an unloaded car with a pry, opening a first valve on a gas-phase arm of the unloaded car to decrease the pressure of the empty tank car of the unloaded car to be consistent with pressure of a BOG header, maintaining the first valve at an opening state, and closing a second valve on a liquid-phase arm of the unloaded car; (2) connecting an overloaded car with the pry, sequentially connecting a gas-phase arm and a liquid-phase arm of the overloaded car to the overloaded car, closing a third valve on the gas-phase arm of the overloaded car and a fourth valve on the liquid-phase arm of the overloaded car; (3) communicating one end of a cold-insulation circulating pipeline with the liquid-phase arm of the overloaded car, communicating the other end of the cold-insulation circulating pipeline with the liquid-phase arm of the unloaded car, opening a fifth valve and a sixth valve on the cold-insulation circulating pipeline, and starting a processing process; and (4) finishing the processing when the liquid level of the overloaded car is lower than the highest liquid level. The overload processing method is safe, reliable and efficient, damage of pipelines and equipment is avoided, and the loading operation of other tank cars is not influenced.

Description

Technical field [0001] The invention relates to a method for processing over loading of an LNG tanker. Background technique [0002] The existing tank truck overloading treatment is the nitrogen injection, boosting, and liquid discharge method. The specific steps are as follows: [0003] After discovering the over-installation, the tanker returns to the loading position and connects the gas phase arm and the liquid phase arm. Close the main circuit valves on the gas phase and liquid phase of the LNG loading on the tanker skid, open the circulating cooling valve, open the nitrogen injection valve on the gas phase arm, inject nitrogen from the top of the tanker to boost the pressure, and use the circulating cooling pipeline to remove the excess The LNG is compressed back into the LNG return line. [0004] This method has the following disadvantages: [0005] 1. Due to the high pressure at the back end of the cold preservation pipeline, the discharge pressure is high and the discharge ...

AI Technical Summary

Problems solved by technology

[0005] 1. Due to the high pressure at the back end of the cold insulation pipeline, the discharge pressure is high, and the discharge effect is not obvious

[0006] 2. Due to the cryogenic characteristics of LNG, part of the nitrogen will be liquefied as the nitrogen is continuously injected later, resulting in no obvious boosting effect of nitrogen, slow boosting and long time-consuming

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