Precooling method and system of LNG unloading arm double-ball valve

Abstract

The invention relates to a precooling system and method of an LNG unloading arm double-ball valve. The precooling system comprises a stainless steel blind plate added on an unloading arm; the stainless steel blind plate is used for blocking a QCDC flange opening of the unloading arm; the system further comprises a metal hose; one end of the metal hose is connected to a downstream drain valve of the unloading arm double-ball valve; the other end of the metal hose is connected to a pressure gauge root valve of a dock circulating pipeline; a precooling flow control valve is arranged on the metal hose. The precooling system is simple in structure and easy to design, and does not rely on an LNG ship, meanwhile, the corresponding precooling method is particularly suitable for the precooling test of the unloading arm double-ball valve after ordinary maintenance, the method is convenient, and timing is flexible.

Description

technical field [0001] The invention relates to the technical field of LNG (liquefied natural gas), in particular to a precooling method and system for a double ball valve of an LNG unloading arm. Background technique [0002] As a clean energy source, LNG is being put into the market on a large scale, and the storage temperature of LNG is -162°C. In the LNG industry, before the double ball valve of the unloading arm is repaired and put into use, the valve needs to be pre-cooled in advance to prevent the sudden cooling during use from causing excessive deformation of the valve seal, resulting in leakage or even damage, and delaying the unloading operation of the LNG ship. Affect the shipping schedule. [0003] At present, the general way of precooling the double ball valve of the unloading arm is as follows: [0004] After the LNG ship is berthed and the unloading arm is connected, the pre-cooling pump in the ship's cabin is started, which is beneficial to the low-flow LNG...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a precooling method and system for the double ball valve of the LNG unloading arm, which is used to solve the problem that the existing double ball valve of the LNG unloading arm is highly dependent on the LNG ship and is not suitable for precooling after maintenance. Technical issues with testing

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