JPH0783117A - Lng transferring device - Google Patents

Abstract

PURPOSE:To dispense with equipment for functioning a gas compressor, and also dispense with countermeasure such as provision of an expansion joint. CONSTITUTION:In an LNG transferring device, LNG inside a tank 1 is vaporized by a vaporizer 3 for press-feeding. In the tank 1, naturally generated gas is suctioned through an gas ejector 4 by the pressure at the time of vaporizing LNG by the vaporizer 3. Then the gas is press-fed together with the LNG vaporized by the vaporizer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LNG transfer device applied to transfer boiler fuel in an LNG (liquefied natural gas) carrier.

[0002]

2. Description of the Related Art FIG. 2 is an explanatory view of a conventional LNG transfer device used for transferring boiler fuel in an LNG carrier. In the figure, BOG (boil-off gas) that naturally occurs in the LNG tank 1 is sucked by the gas compressor 10 and heated by the BOG heater 6, then sent to the LNG box 7, and injected from the boiler burner 9 in the boiler. To burn. In the case where the spontaneously generated BOG is insufficient, the boiler fuel is insufficient, and the LNG in the LNG tank 1 is pumped up by the pump 2, forcibly vaporized by the forcing vaporizer 3 and mixed with the naturally occurring BOG, and then the gas compressor. 10, the pressure is fed into the LNG box 7 through the BOG heater 6, and is injected and burned from the boiler burner 9.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the NG transfer device, since the gas compressor 10 is driven by an electric motor and the gas compressor 10 is also a rotary machine, various equipment for operating the gas compressor 10 such as electric wiring and lubricating oil piping. Need. Also,
Since LNG, which is a low-temperature fluid, is handled, there is a possibility that deformation may occur in pipes and equipment, causing a shift in the axis, etc., and it is necessary to take measures such as providing an expansion joint. Further, since the gas compressor 10 has moving parts, maintenance and labor require labor and cost.

[0004]

The LNG transfer device according to the present invention is intended to solve the above-mentioned problems, and the LNG transfer device in the tank is
In an LNG transfer device that vaporizes NG by a vaporizer and sends it under pressure, an LN vaporized by the vaporizer when a gas naturally generated in the tank is sucked through a gas ejector by the pressure when the LNG vaporizes in the vaporizer.
It is characterized in that it is pumped together with G.

[0005]

That is, in the LNG transfer device according to the present invention, the gas naturally generated in the tank in the LNG transfer device in which the LNG in the tank is vaporized and pressure-fed by the vaporizer is gasified by the pressure when the LNG is vaporized in the vaporizer. L sucked through the ejector and vaporized by the vaporizer
It is designed to pump together with NG. Instead of a gas compressor, a gas ejector that functions by the pressure gas generated in the vaporizer is used to suck in the gas naturally generated in the tank and pump it together with the LNG vaporized in the vaporizer. To do.

[0006]

FIG. 1 is an explanatory view of an LNG transfer device according to an embodiment of the present invention. In the figure, LNG according to the present embodiment
The transfer device is used to transfer boiler fuel in an LNG carrier, and as shown in the figure, the gas ejector 4 is used instead of the gas compressor used in the conventional LNG transfer device, and the boiler burner is used instead. Each of the gas ejectors 8 is used, and BOG (boil-off gas) naturally generated in the LNG tank 1 is sucked by the gas ejector 4 and heated by the BOG heater 6, and then L
The gas is sent into the NG box 7 and injected from the gas ejector 8 in the boiler to be burned. In the case where the spontaneously generated BOG is insufficient, the boiler fuel is insufficient, and the LNG in the LNG tank 1 is pumped up by the pump 2, forcibly vaporized by the forcing vaporizer 3 and mixed with the naturally occurring BOG, and then the gas ejector 4 is used. Thus, it is pressure-fed to the inside of the LNG box 7 through the BOG heater 6, and is injected from the gas ejector 8 to be burned.

LNG pumped up from the LNG tank 1 by the pump 2 is forcibly vaporized by the forcing vaporizer 3 and sent to the gas ejector 4 as a pressurized gas. This pressurized gas acts as a fluid that causes the ejector 4 to function, and after sucking and mixing the BOG generated in the LNG tank 1, it passes through the pump 2 and the BOG heater 6 by the gas pressure when it is forcibly vaporized. It is pumped into the LNG box 7. The gas ejector 8 used in place of the boiler burner in the conventional LNG transfer device sucks the fuel gas from the inside of the LNG box 7 by the flow of the combustion air, and injects it at a pressure combined with the transfer pressure from the gas ejector 4. And burn it. When LNG is not forcibly vaporized by the forcing vaporizer 3, the gas ejector 8 is used as a main device for sucking BOG. When the BOG amount may be small, the pump 2 is stopped and only the gas ejector 8 is sucked. When a large amount of BOG is required, the pump 2 is driven and the BOG is sucked from the gas ejector 4. BO
The G amount is controlled by the ACC (automatic combustion control device), and the pump 2 alone is controlled by the PIC (pressure instruction control device).

In the conventional LNG transfer device, since the gas compressor is driven by an electric motor and the gas compressor is also a rotating machine, it is necessary to operate the gas compressor such as electric wiring and lubricating oil piping. Requires various equipment. Further, since LNG of low-temperature fluid is handled, there is a case where deformation occurs in a pipe line or a device and the shaft center is displaced, and it is necessary to take measures such as providing an expansion joint. Further, since the gas compressor has moving parts, it requires labor and cost for maintenance, but in this LNG transfer device, the gas ejector 4 is used instead of the gas compressor used in the conventional LNG transfer device. In addition, the gas ejector 8 is used instead of the boiler burner, and the gas ejector 4 installed as an alternative to the gas compressor functions by the pressurized gas generated in the forcing vaporizer 3 and the fuel gas is LNG. Suction from tank 1 and pump. Further, the gas ejector 8 used as a substitute for the boiler burner functions by the flow of the combustion air, and when the forcing vaporizer 3 is generating gas, it assists the gas ejector 4 upstream and fuel in the burner section. To improve the drive effect of the gas used,
When the forcing vaporizer 3 is not generating gas, it acts as a main ejector for sucking BOG. In this way, by using the gas ejector 4 as an alternative to the gas compressor, a prime mover is not required, power is not consumed because there is no power unit, and the installation location is reduced and it is necessary to use electrical wiring. Disappear. Also,
Since there are no moving parts, lubricating oil and piping for supplying lubricating oil are unnecessary, and maintenance is simplified. Further, it is not necessary to consider deformation and axial misalignment due to the influence of temperature that occurs when handling LNG of a low temperature fluid, and devices such as an expansion joint for absorbing the deformation and the installation space thereof can be reduced. Further, the gas ejector 4 is less expensive than the gas compressor. Further, by using the gas ejector 8 as an alternative to the boiler burner, the drive effect of the fuel gas is improved.

[0009]

The LNG transfer device according to the present invention is configured as described above, and uses a gas ejector instead of the gas compressor for pressure feeding. Therefore, various equipment for operating the gas compressor is required. In addition, it is not necessary to take measures such as providing an expansion joint.

[Brief description of drawings]

FIG. 1 is a flow diagram of an LNG transfer device according to an embodiment of the present invention.

FIG. 2 is a flow diagram of a conventional LNG transfer device.

[Explanation of symbols]

 1 LNG tank 2 Pump 3 Forcing vaporizer 4 Gas ejector 6 BOG heater 7 LNG box 8 Gas ejector 11 Windbox 12 Gas pipeline

Claims (1)

[Claims] 1. A LNG transfer device for vaporizing LNG in a tank by vaporizing with a vaporizer, and sucking a gas naturally generated in the tank through a gas ejector due to the pressure at which LNG vaporizes in the vaporizer. An LNG transfer device which is pressure-fed together with LNG vaporized by a vaporizer.