Liquid anti-rollover positioning, filling and circulation device for LNG storage tanks

Abstract

The invention discloses a liquid anti-rollover positioning filling and circulation device for a liquefied natural gas storage tank. The main control switch valve is installed on the material pipe, and the heavy and light branch pipe switch control valves are respectively installed on the heavy and light branch pipes. The inlet of the raw material branch pipe is connected, the outlet end of the light material branch pipe is connected with the inlet of the light material branch pipe, and a multi-branch switch control valve is installed on each heavy and light material branch pipe. Injection rings are installed in the inner interval, and multiple nozzles are arranged on each injection ring. The outlet end of the heavy material branch pipe is connected with the multiple injection rings arranged on the upper part one by one, and the outlet of the light material branch pipe The ends communicate with the injection rings arranged in the lower part in one-to-one correspondence. The adoption of the device greatly reduces the probability of rollover.

Description

technical field [0001] The invention relates to a liquefied natural gas storage tank, in particular to a liquid anti-rollover positioning filling and circulation device for a liquefied natural gas storage tank. Background technique [0002] Liquefied natural gas is referred to as LNG. With the rapid growth of my country's imported LNG, the storage tanks of LNG receiving stations play an important role as facilities for unloading, storing and exporting LNG. Receiving terminals are usually designed for continuous production operations, and once in operation, it is impossible to empty the LNG storage tanks to store LNG. The existing unloading flushing pipe is single-entry or double-entry (such as figure 1 ), the double-entry discharge pipe form consists of main discharge pipe 1-1, heavy (larger density LNG liquid discharge pipe) sub-discharge pipe 4-1, light weight (lower density LNG liquid discharge pipe ) 5-1, and branch pipe switch control valves 2-1, 3-1. Due to the diff...

AI Technical Summary

Problems solved by technology

Due to the different LNG densities of different origins and different batches, after a period of time after filling new LNG with different densities and temperatures, the LNG will be stratified in the storage tank. Rollover occurs, which poses a great threat to the safety of the storage tank and also increases the cost of dealing with the BOG (boil-off gas) generated by the rollover

[0003] The patent No. WO 2009 / 011497 discloses unloading at the top and bottom of the storage tank, and cannot specifically control the unloading liquid level

"Natural Gas Industry", Volume 28, Issue 5, the circulation device in Figure 4 in "LNG Overturning Mechanism and Preventive Measures in Large Tanks" published by Wang Liangjun and Liu Yang is an independent circulation device, not integrated with the unloading device

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