LNG (liquefied natural gas) fuel supply method and device utilizing BOG (boil-off gas) preferentially

Abstract

The invention relates to an LNG (liquefied natural gas) fuel supply method and device utilizing BOG (boil-off gas) preferentially and solves problems that the reliability is poor, equipment is easily frozen and cannot work during starting and the fuel utilization rate is low in existing LNG gas fuel supply. According to the technical scheme, the LNG fuel supply device comprises an LNG storage tank, wherein a liquid outlet in the bottom of the LNG storage tank is connected with a gasifier through a pressurization pipe; the gasifier comprises a fuel heat exchanger and a self-pressurization heat exchanger; the pressurization pipe is connected with a gas inlet in the top of the LNG storage tank through the self-pressurization heat exchanger of the gasifier; a gas outlet in the top of the LNG storage tank is connected with gas equipment through a gas supply pipe and the fuel heat exchanger. The LNG fuel supply device is simple in structure, simple and convenient to operate, small in volume, high in reliability, good in safety, low in equipment investment and running cost, high in fuel utilization rate and environment-friendly.

Description

technical field [0001] The invention relates to an LNG fuel gas supply method and device. Background technique [0002] Based on the common understanding, the oil in the oil tank is fuel, and the oil fuel is sucked from the lower part of the oil tank to supply the fuel oil facilities. However, the gas in the space above the oil in the oil tank is not considered as a fuel available for reference, and is often discharged directly for decompression. [0003] The current LNG gas fuel gas supply device, such as the gas fuel supply of LNG-powered ships, adopts a gasification gas supply process in which LNG (liquid) is gasified into gaseous NG. The gas supply device for direct gasification of LNG adopts the low-level gas supply method of the LNG storage tank, which increases the number of low-level interfaces. The pipeline valves need to be opened and closed daily, and there are many connection nodes, which greatly increases the risk of leakage. What's more, before and at the beg...

AI Technical Summary

Problems solved by technology

[0005] During the operation of engines and other natural gas-fired facilities, due to changes in load and gas consumption, the pressure of the upstream gas will fluctuate, and the volume of LNG will expand rapidly after gasification, which will bring great pressure to the gas supply system. Pressure fluctuations, especially when the load decreases, even hot gas will flow back to the LNG storage tank, resulting in excessive BOG pressure, and the safety valve will open and release

Images