LNG receiving station terminal evaporated gas recovery system

Abstract

The invention discloses a terminal evaporated gas recovery system of an LNG receiving station. The terminal of the LNG receiving station includes an LNG storage tank; a BOG low-pressure compressor or blower communicates with the LNG storage tank for compressing the evaporated gas generated in the LNG storage tank; the BOG low-pressure compressor Or the blower is connected with the BOG / LNG heat exchanger; the high-pressure LNG output pipeline of the BOG / LNG heat exchanger is connected with the LNG vaporizer, and the low-pressure LNG output pipeline of the BOG / LNG heat exchanger is connected with the The LNG storage tank is connected; the LNG storage tank is connected with an LNG delivery pipeline, the LNG delivery pipeline is provided with a low-pressure pump and / or a high-pressure pump, and the output end of the LNG delivery pipeline is connected to the BOG / LNG The heat exchangers are connected. The invention utilizes the cold capacity of high-pressure liquefied natural gas (usually 7MPaG-10MPaG) to exchange heat with the evaporated gas generated by the receiving station in a heat exchanger, condenses the evaporated gas into liquefied natural gas, and finally recycles it into the liquefied natural gas storage tank.

Description

technical field [0001] The invention relates to a terminal evaporated gas recovery system of an LNG receiving station, which belongs to the field of liquefied natural gas. Background technique [0002] With the rapid development of my country's natural gas market, the proportion of natural gas in energy supply has increased rapidly, and the contradiction of insufficient natural gas supply has become more and more obvious. The output of liquefied natural gas (hereinafter referred to as "LNG") is growing at a high rate of about 12% per year, becoming one of the fastest growing energy industries, and the construction of LNG receiving stations has also set off a boom. [0003] The LNG receiving station will produce boil-off gas (hereinafter referred to as "BOG") due to the introduction of external heat. Generally, the BOG processing methods of the LNG receiving station include direct output and recondensation. The direct output method is to compress the boil-off gas to the exte...

AI Technical Summary

Problems solved by technology

However, the traditional recondensation method uses the cooling capacity of the low-pressure section (usually 0.6MPaG-1MPaG) of the LNG receiving station, and the BOG needs to be pressurized to the above-mentioned pressure by the compressor to condense with the LNG. Large energy input, on the other hand, the larger subcooling capacity of the high-pressure section (usually 7MPaG-10MPaG) of the LNG receiving station is not utilized

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