Sleeve type spraying system used for liquid tank precooling of liquefied natural gas (LNG) vessel and spraying method of sleeve type spraying system

Abstract

The invention discloses a sleeve type spraying system used for liquid tank precooling of a liquefied natural gas (LNG) vessel and a spraying method of the sleeve type spraying system. The sleeve type spraying system comprises a hydraulic sleeve system and a spraying executing mechanism. The hydraulic sleeve system is embedded in the central of a ceiling of a liquid tank, penetrates through a multi-layer structure of a liquid tank cargo maintaining system and then reaches the interior of the liquid tank. The spraying executing mechanism is internally embedded in the hydraulic sleeve system. The hydraulic sleeve system is used for controlling the spraying executing mechanism to unfold and fold. According to the sleeve type spraying system used for liquid tank precooling of the LNG vessel and the spraying method of the sleeve type spraying system, the defects of an existing spraying device used for liquid tank precooling of an LNG vessel are overcome, the atomization effect of a precooling agent is improved, a flow field formed by the precooling agent in the liquid tank is more uniform during precooling, and then the precooling efficiency is improved, the precooling time is shortened, and the operation economy of the LNG transport vessel is improved.

Description

technical field [0001] The invention relates to a spraying system for precooling liquid tanks of LNG ships, in particular to a casing type spraying system and a spraying method for precooling liquid tanks of LNG ships. Background technique [0002] With the adjustment of energy structure, the utilization rate of natural gas resources has increased sharply, and the development of my country's natural gas industry has also entered a new stage. The temperature of liquefied natural gas (LNG) under normal pressure is about -163°C. Large-scale LNG storage and transportation equipment cannot withstand high pressure and can only be transported under normal or low pressure conditions. [0003] Liquefied natural gas can be roughly divided into the following five parts from production to use: LNG production, transportation, reception, distribution, and users. There are certain storage and transportation problems in each link. [0004] LNG carrier refers to a special ship that transpor...

AI Technical Summary

Problems solved by technology

This type of spraying method is mostly limited by the fixed installation position of the spraying actuator, it is difficult to make the precoolant evenly distributed in the liquid tank space, and the liquid precoolant is poorly atomized, which is not compatible with the tank cargo maintenance system and the tank. The heat exchange area of ​​the internal fluid is small, and the heat absorption effect of the precoolant is not good, so there are two problems: one is, when the LNG ship is unloaded and before it is reloaded, when the liquid tank is precooled before it arrives at the port for loading, The pre-coolant passes through the liquid tank spray device fixedly installed in the center of the tank ceiling, and its trajectory is limited to a cone within a certain angle, which makes the liquid pre-coolant atomized poorly and will inevitably reduce the cooling effect of the pre-coolant; the second is , because the pre-coolant will not achieve a good atomization effect under this spraying device, which will reduce the cooling rate of the pre-coolant, prolong the pre-cooling time for the LNG tank of the whole ship, and reduce the cost of the LNG carrier. economy

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