BOG processing system utilizing pressure energy of LNG receiving station

Abstract

The invention relates to a BOG processing system utilizing pressure energy of an LNG receiving station. A high pressure LNG transportation branch is separated from a high pressure LNG outer transportation line of an existing natural gas transportation system of the LNG receiving station; the output end of the high pressure LNG transportation branch is connected with the input end of a liquid-gas ejector mixer; the output end of the liquid-gas ejector mixer is connected with the input end of a medium-high pressure vaporizer; the liquid-gas ejector mixer is also provided with a low pressure suction inlet; the low pressure suction inlet is connected with the output end of a vapor-discharging total pipe of an LNG storage tank; and the vapor-discharging total pipe is provided with a vapor flow control valve that can be adjusted according to pressure conditions of the LNG storage tank. Low pressure BOG discharged by cooling the LNG storage tank is absorbed by using the pressure energy of the output high temperature LNG; full mix and energy exchange between the high pressure LNG and the low pressure BOG are completed in the liquid-gas ejector mixer; the mixed fluid is medium-high pressure LNG; and the medium-high pressure LNG is converted into a medium-high pressure natural gas by the medium-high pressure vaporizer and then is supplied to users of the medium-high pressure natural gas.

Description

technical field [0001] The invention relates to a BOG processing system of an LNG receiving station, in particular to a BOG processing system utilizing the pressure energy of the LNG receiving station which utilizes the pressure energy of the high-pressure LNG itself to absorb the condensed low-pressure BOG. Background technique [0002] LNG receiving stations generally undertake the functions of receiving, storing and gasifying LNG for export. Since LNG (Liquefied Natural Gas, liquefied natural gas) is a low-temperature fluid, although LNG equipment has good insulation measures, a certain amount of BOG (Boiled Off Gas, boil-off gas) will inevitably be generated due to heat conduction during production and operation. As the number of BOG increases, the temperature and pressure in the LNG storage system will increase accordingly. If the internal pressure of the LNG storage tank is higher than the safety relief pressure set by the system, the safety valve on the top of the ta...

AI Technical Summary

Problems solved by technology

These traditional technologies have the problems of complex process system design, cumbersome operation, high investment in disposable equipment (equipment backup needs to be considered) and high energy consumption.

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