Low-pressure gas supply system capable of realizing high-efficiency utilization of cold energy of LNG fuel

Abstract

The invention discloses a low-pressure gas supply system capable of realizing high-efficiency utilization of cold energy of LNG fuel. The low-pressure gas supply system is provided with a central fresh water circulating system and a high-temperature cylinder jacket water circulating system; an LNG low-pressure pump is arranged in an LNG storage tank; the LNG low-pressure pump is connected with each of the high-temperature cylinder jacket water circulating system and the central fresh water circulating system through a pipeline, an LNG evaporator, a BOG preheater and the like; low-temperature LNG is pumped out and is conveyed to the LNG evaporator through the LNG low-pressure pump; and the LNG storage tank is connected with the BOG preheater through the pipeline. According to the low-pressure gas supply system capable of realizing high-efficiency utilization of the cold energy of the LNG fuel, liquid LNG and BOG in the LNG storage tank are converted into natural gas to provide fuel fora low-pressure dual-fuel main engine, a dual-fuel electric generator and a dual-fuel boiler after being subjected to evaporating and heating treatment through a heat exchanger to complete cold energyrelease; through the LNG fuel low-pressure gas supply system, the cold energy released by low-temperature liquid LNG and BOG in a gas supplying process can be utilized by the high-temperature cylinderjacket water circulating system and the low-temperature central fresh water circulating system of a ship, so that high-efficiency utilization of the cold energy in the operation of the ship is realized; and energy consumption is reduced.

Description

technical field [0001] The invention relates to the fields of ship building and ship design, in particular to a low-pressure gas supply system for efficiently utilizing cold energy of LNG fuel. Background technique [0002] For ships powered by LNG fuel, the existence of natural gas fuel in the form of liquid LNG is beneficial for its storage and transportation, but as a ship fuel supply, it needs to be further pressurized, gasified, and heated before it can be used by the main and auxiliary engines. At present, the X-DF series of low-speed two-stroke dual-fuel engines launched by WinGD are favored by the market due to their good emission characteristics. It is called a low-pressure gas supply system. Usually, the pressurization of LNG fuel in this system is completed by a low-temperature fuel pump, and the gasification and heating of LNG fuel are performed through a shell-and-tube heat exchanger, and the heat exchange medium is water-ethylene glycol and LNG. Glycol is hea...

AI Technical Summary

Problems solved by technology

This heat exchange method needs to consume a large amount of boiler steam. For large ocean-going ships equipped with X-DF dual-fuel main engines, when the boiler steam load is matched, it is generally necessary to provide at least 2 tons / hour of additional steam to meet the entire LNG supply. The demand for heat exchange of the gas system, that is, the consumption of about 3.5 tons / day of fuel oil or 3 tons / day of natural gas fuel

Images