A system for recovering, storing and utilizing vaporized gas in liquid cargo tanks by using tube-bundle high-pressure gas cylinders

Abstract

The invention discloses a system for recovering, storing and utilizing boil-off gas in a liquid cargo tank of an LNG ship by using a tube-bundle type high-pressure gas cylinder group, including a vacuum-proof valve, a gas compressor, a heat exchanger, a tube-bundle type high-pressure gas storage cylinder group, and a gas pressure regulating valve And the buffer gas cylinder is connected to the gas host in turn to provide LNG BOG gas fuel for the host. The invention realizes the recovery, storage and utilization of the evaporated gas of the liquid cargo tank at normal temperature, controls the pressure of the cargo tank within a safe range, solves the problem of excess or insufficient LNG BOG, provides a stable BOG fuel supply for the main engine, and avoids the loss of the LNG evaporated gas. Vents to atmosphere, costly reliquefaction units or gas flares, avoid the use of insulating materials and cryogenic steel. The invention realizes energy saving and emission reduction, natural gas saving, environmental protection, low cost, flexible arrangement and universal use.

Description

【Technical field】 [0001] The invention relates to the technical field of water transportation equipment manufacturing, in particular to a system for recovering, storing and utilizing LNG ship cargo tank evaporated gas by using a tube bundle type high-pressure gas cylinder group to supply gas fuel main engine / generator. 【Background technique】 [0002] LNG ships transport and store liquefied natural gas at atmospheric pressure -163 °C. Due to the influence of external heat, the movement of the ship, and the heat generated by the operation of the submersible pump in the LNG tank, the LNG in the tank will evaporate and BOG will be generated. To keep the LNG cargo tank pressure within a safe range, these BOG gases must be continuously vented. At present, there are mainly the following methods to deal with these BOGs. These methods have the following disadvantages: [0003] 1. The most common method is that BOG is used by gas fuel main engines and generators, and there is often a...

AI Technical Summary

Problems solved by technology

[0003] 1. The most commonly used method is that BOG is used by gas fuel hosts and generators, and the problem of insufficient or excess BOG often occurs

Especially for large LNG ships, with a large loading capacity, BOG surplus often occurs when they are fully loaded, berthed or maneuvering in and out of ports, and BOG shortages often occur during ballast sailing conditions

[0004] 2. Excess BOG is released into the atmosphere (empty release), which wastes resources, pollutes the environment, is flammable and explosive, and is unsafe. The greenhouse effect of methane is higher than that of carbon dioxide, and ports are not allowed to discharge like this

[0005] 3. Burn it with gas combustion unit (GCU), waste resources and pollute the environment

The reliquefaction unit is expensive, the energy consumption is too large, and the economy is poor

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