 Working Principle The storage tank is double vacuum insulated tank, with a design pressure of 9-12 Bar, and gas supply pressure ≤10bar. When there is no gas consumption,the ventless storage duration of the tank is 15 days (the pressure of the storage tank can be maintained for at least 15 days without over pressure discharge). A water bath gasifier is used to pressurize the tank. The self-pressure of the tank will make the LNG liquid flow through the LNG gasification & heater. The gasified and heated LNG will be supplied to the gas equipment in the engine room. The gasification and heating can be controlled according to the gas consumption of the main engine. The LNG fuel tank is equipped with an economic loop, when the gaseous phase pressure of the tank is too high, the BOG as in the tank will be used preferentially until the gas phase pressure drops to the setting pressure, the self - contained pressure reducing and regulating valve closed, and the tank will continues to supply liquid.Low Pressure LNG Fuel System —— Low pressure LNG supply system (self-pressurized) Features ● High vacuum multilayer heat insulation or vacuum pearlite accumulation heat insulation can be applicable
● With good thermal insulation performance, excellent daily evaporation rate, and long ventless storage duration, the tank can effectively reduce fuel consumption ● No need of LNG pump and gas compressor, the system is easy to operate and maintenance cost low ● LNG gasifier and heater utilize water bath gasifier structure, and recycle cooling water from engine ● It is suitable for double vacuum insulated pressure storage tank with volume no more than 300m3 Low Pressure LNG Fuel System —— Low pressure LNG supply system (pump pressurized) Working Principle The complete system is mainly aimed at large LNG storage tanks and large vessel. Type B cabin or Type C cabin with thermal insulation layer are applicable for this system. The system is equipped with: LNG pumps (installed in storage tanks), gas compressor units, LNG gasifier and heater etc. The gas compressor will start and stop according to the pressure of the tank to keep the tank under normal working pressure. The continuous running of LNG pump supply LNG liquid to gasifier and heater, then, the gasified and heated gas will be supplied to fuel equipment on vessel. When the main engine is working, the vaporized gas in the storage tank can be condensed by the liquid discharged from the LNG pump, the condensed liquid return the LNG tank. Features ● Accumulation heat insulation or form heat insulation are applicable● The gas supply pressure ≤10bar, which can meet gas supply for almost all the low pressure main engine ● Occupy the Space small, high degree of automation, and easy to operate ● A normal temperature compressor is used to process the evaporation gas. The compressor unit can be started directly without precooling Features ● The self-balance re-liquefaction saves the installation cost● Low power consumption ● High pressure double-pipe heat exchanger is easy to manufacture ● Satisfy the gas supply both for high pressure main engine and low pressure auxiliary engine Working Principle When the pressure in the tank is too high, the BOG vaporized gas in the tank can be processed by the compressor and transferred to the buffer tank to provide 6Bar gas to the onboard gas generator or boiler. Meanwhile, the low-pressure liquid in the daily service tank can also be transferred to the buffer tank after gasification by the low-pressure heat exchanger. When the evaporation rate of the tank greater than the gas supply from the gas generator, the fuel gas pre-cooled by the high pressure double-pipe heat exchanger can return the LNG daily tank for cooling, we called it “self-balance re-liquefaction”. The LNG pump transfer the low temperature（-160 ℃） liquid to LNG daily tank, keep the pressure in the daily tank is at about 6Bar, and temperature below -132℃ . The “self-balance re-liquefaction” method can be used only when the main engine is working and the gas consumption of the main engine is 6 times more than the evaporation rate of the storage tank. The continuous running of booster pump will supply 315 kg liquid to high pressure double-pipe heat exchanger. High Pressure LNG Fuel System —— |
Contact Details Sales Tel.：+86 25 85549445 Company Tel.：+86 25 57700077 Sales E-mail：sales@secorp.cn Aftersales E-mail：cs@secorp.cn Post Code：210048 Address：No. 398, Wangxin Road, Zhongshan Science & Technology Park, Luhe District, Nanjing, Jiangsu, PRC
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