JPH08178191A - Suppression device for bog generated in lpg storage tank - Google Patents

Abstract

PURPOSE: To suppress the generation of BOG generated in an LPG storage tank through high-efficient cooling by mounting an injection nozzle through which supercooled LPG is injected against a liquid phase on the inner bottom of an LPG storage tank in such a state to spread toward below. CONSTITUTION: An injection nozzle 11 through which supercooled LPAG is injected against a liquid phase on the inner bottom of an LPG storaged tank 1 in such a state to spread toward below is mounted. LPG supercooled by an LPG heat-exchanger 6 is injected at the inner bottom of the LPG tank 1 through the injection nozzle 11. Since, during the injection, the injection nozzle 11 injects supercooled LPG in such a state to spread toward below, though an injection area is localized at a nozzle 11 part, the injection area is spread toward an end and the supercooled LPG is well mixed with liquid in the tank 1 and convection is generated in the tank 1. This constitution suppresses the generation of BOG.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for suppressing BOG generated in an LPG storage tank.

[0002]

2. Description of the Related Art BO enters a LPG storage tank by heat input.
Since G is generated, it is necessary to suppress the generation of BOG and keep the tank internal pressure constant. This method is a so-called top feed method in which LPG in the tank is once pumped out of the tank, supercooled by using a supercooling liquid such as LNG, and the supercooled LPG is dispersed in the gas phase in the tank. A bottom feed method is known in which the liquid is returned to the liquid in the tank. The present invention relates to the latter bottom feed method, but the jet outlet in the liquid in the conventional bottom feed method is configured to face downward, sideways, or obliquely upward.

[0003]

However, the bottom feed method has the following drawbacks. Supercooled LP
Since G only jets downward, sideways or obliquely upward in the liquid, the diffusion effect in the liquid is small, and convection is generated in the liquid so that the supercooled LPG does not mix well. As a result, the cooling efficiency of the liquid in the tank is low.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and the constitution thereof is as follows. 1. LPG in the LPG storage tank is pumped out by using an LPG pump and led to the LPG heat exchanger, and supercooled liquid is led from the supercooled liquid line into the LPG heat exchanger.
In a device for suppressing BOG generation by supercooling PG, returning the supercooled LPG to the liquid phase at the bottom of the LPG storage tank to cool the liquid in the LPG storage tank,
An injection nozzle L for injecting supercooled LPG in a divergent manner is attached to the liquid phase at the bottom of the LPG storage tank.
A device for suppressing BOG generated in a PG storage tank. 2. 1. In the above-mentioned 1, the apparatus for suppressing BOG generated in the LPG storage tank, which is formed by forming the injection port of the injection nozzle on three limbs. 3. In the above 1 or 2, a device for suppressing BOG generated in an LPG storage tank, which uses LNG as a supercooling liquid.

[0005]

The LPG supercooled by the LPG heat exchanger is injected from the injection nozzle at the bottom of the LPG tank.
At the time of this injection, the injection nozzle is supercooled L in a flared shape.
Since it has a characteristic of injecting PG, the injection area is localized in the nozzle portion, but it expands as it goes forward and mixes well with the liquid in the tank to prevent convection in the tank.

[0006]

FIG. 1 shows an embodiment of the present invention, in which 1 is LPG.
Storage tank, 2 LPG pump, 3 LPG pumping line, 4 LPG pumping branch line, 5 LPG control valve, 6 LPG heat exchanger, 7 supercooled LPG line, 8 supercooled liquid (LNG) line , 9 is a supercooled liquid branch line, 10 is a supercooled liquid control valve, 11 is a supercooled LPG injection nozzle installed obliquely upward at a position near the bottom of the LPG storage tank 1. The injection port 12 is divided into three limbs as shown in FIG.

In the case of the above embodiment, the LPG pumped from the LPG storage tank 1 is supercooled by the supercooling liquid in the LPG heat exchanger 6 and injected into the liquid from the injection nozzle 11 at the bottom of the tank. Since this injection area becomes wider at the end,
While efficiently mixing, the convection is prevented from occurring as much as possible to cool the liquid in the tank, thereby suppressing the generation of BOG. In addition, although the injection nozzle 11 of the embodiment has three limbs, any shape may be used as long as it has a function of injecting in a divergent manner.

[0008]

As described above, according to the present invention, when the supercooled LPG is returned to the LPG storage tank, the injection nozzle for ejecting the injection liquid is selected and attached to the liquid phase at the bottom of the tank. As a result, it is possible to efficiently cool the liquid in the tank while suppressing the convection of the liquid phase and suppress the generation of BOG. As a result, it is possible to reduce the BOG suppressing equipment and the BOG suppressing operating cost as compared with the conventional bottom feed method.

[Brief description of drawings]

FIG. 1 is an explanatory view of an apparatus for suppressing BOG generation according to the present invention.

FIG. 2 is an explanatory diagram of an embodiment of a supercooled LPG injection nozzle.

[Explanation of symbols]

 1 LPG storage tank 2 LPG pump 3 LPG pumping line 4 Pumping branch line 5 LPG control valve 6 LPG heat exchanger 7 Supercooling LPG line 8 Supercooling liquid line 9 Supercooling liquid branching line 10 Supercooling liquid control valve 11 Injection nozzle 12 Jet

Claims (3)

[Claims] 1. The LPG in an LPG storage tank is pumped out by using an LPG pump and led to an LPG heat exchanger, and the supercooled liquid is introduced from the supercooled liquid line into the LPG heat exchanger to supercool the LPG. However, in the device for suppressing the generation of BOG by returning the supercooled LPG to the liquid phase at the bottom of the LPG storage tank to cool the liquid in the LPG storage tank, the liquid phase at the bottom of the LPG storage tank is spread out. A device for suppressing BOG generated in an LPG storage tank, in which an injection nozzle for injecting supercooled LPG is attached to. 2. The B generated in an LPG storage tank according to claim 1, wherein the injection port of the injection nozzle is formed in three limbs.
OG suppression device. 3. The B generated in the LPG storage tank according to claim 1, wherein LNG is used as the supercooling liquid.
OG suppression device.