BOG heating utilization and LNG revaporization system and control method thereof

Abstract

The invention discloses a BOG heating utilization and LNG revaporization system. The BOG heating utilization and LNG revaporization system comprises an LNG storage tank, a heat exchange working medium circulation subsystem and a cold energy recovery subsystem, the heat exchange working medium circulation subsystem comprises a heat exchange working medium, a first heat exchanger and a second heat exchanger, the heat exchange working medium sequentially passes through the first heat exchanger and the second heat exchanger for heat exchange, the cold energy recovery subsystem comprises a third heat exchanger and air, a heat exchange working medium passes through the second heat exchanger and then exchanges heat with the air through the third heat exchanger, low-temperature air is obtained, the LNG storage tank is provided with a BOG outlet connected with the first heat exchanger, and an immersed pump connected with the second heat exchanger and used for extracting LNG is arranged in the LNG storage tank. The heat exchange working medium is added for heat exchange transition, the heat exchange working medium generates phase change in the heat exchangers and absorbs or releases a large amount of latent heat, interchange of air heat energy and LNG and BOG cold energy is achieved, BOG heating, LNG revaporization and cold energy recovery are completed at the same time, energy waste is avoided, and the system is simple, efficient and high in economic benefit.

Description

technical field [0001] The invention relates to natural gas production, in particular to a BOG heating utilization and LNG regasification system and a control method thereof. Background technique [0002] With the rapid increase of natural gas (Natural Gas, referred to as NG) demand and the development of liquefied natural gas (Liquefied Natural Gas, referred to as LNG) industry chain, offshore LNG floating storage and regasification unit (Floating Storage and Revaporization Unit, FSRU) is increasingly widely used , At present, a complete industrial system has been gradually formed from production, storage and transportation, shipment to receiving, regasification, refrigeration utilization, peak shaving, etc. During the storage and transportation of LNG, under the action of wind, wave and current, the FSRU will slosh, and at the same time, the LNG storage tank or adiabatic cabin will inevitably exchange heat with the outside world, resulting in the continuous vaporization of...

AI Technical Summary

Problems solved by technology

In the prior art, different heat sources are used to act on the two processes of BOG heating utilization and LNG regasification respectively, which makes the whole heat exchange system cumbersome and costly

Moreover, in the heat exchange process, the heat source directly exchanges heat with BOG and LNG, which may easily cause the heat exchange medium to freeze or incompletely vaporize.

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