KR-20260064865-A - Boil-Off Gas Handling System

Abstract

The present invention relates to an evaporative gas treatment system comprising: a liquefied gas storage tank; a bunkering line connected from a manifold to the liquefied gas storage tank; an evaporative gas supply line that supplies evaporative gas generated from the liquefied gas storage tank to a fuel demand source; and a first bypass line that branches off from the evaporative gas supply line and is connected to the bunkering line; and an evaporative gas treatment system that purges the bunkering line with evaporative gas supplied through the first bypass line, wherein the evaporative gas generated from the liquefied gas storage tank during the bunkering process is supplied to the bunkering line and utilized to purge the bunkering line, thereby preventing in advance the problem of the inert gas freezing that may occur when the existing inert gas meets liquefied hydrogen.

Inventors

• 장준혁
• 유지헌

Assignees

• 에이치디한국조선해양 주식회사
• 에이치디현대미포 주식회사

Dates

Publication Date

20260508

Application Date

20241030

Claims (6)

1. Liquefied gas storage tank; A bunkering line connecting the manifold to the above-mentioned liquefied gas storage tank; An evaporative gas supply line that supplies evaporative gas generated from the above-mentioned liquefied gas storage tank to a fuel demand source; and It includes a first bypass line that branches off from the above evaporative gas supply line and connects to the above bunkering line; and A vapor treatment system that purges the bunkering line with vapor supplied through the first bypass line.
2. In claim 1, A preheater provided on the above-mentioned evaporative gas supply line for heating the evaporative gas supplied from the above-mentioned liquefied gas storage tank; and An evaporative gas treatment system comprising a compressor provided at the downstream end of the preheater on the above evaporative gas supply line, for compressing the evaporative gas heated in the preheater.
3. In claim 1, An evaporative gas treatment system comprising a first valve provided on the first bypass line.
4. In claim 2, An evaporative gas treatment system comprising a second bypass line that branches off from the evaporative gas supply line upstream of the preheater and joins the evaporative gas supply line downstream of the compressor.
5. In claim 4, An evaporative gas treatment system including a second valve provided in the second bypass line.
6. In claim 1, A boil-off gas treatment system for storing liquid hydrogen in the above-mentioned liquid gas storage tank.

Description

Boil-Off Gas Handling System An embodiment of the present invention relates to an evaporative gas treatment system, and more specifically, to an evaporative gas treatment system used to purge a bunkering line of evaporative gas generated in a liquefied gas storage tank. Liquefied gases such as hydrogen, ammonia, LNG (Liquefied Natural Gas), and LPG (Liquefied Petroleum Gas) are transported in a liquefied state after being forcibly liquefied by increasing the pressure or lowering the temperature, and stored in liquefied gas storage tanks. Although liquefied gas is stored in a liquid state in insulated storage tanks, external heat is continuously transferred to the tank, causing the gas to naturally vaporize within the tank and generate Boil-Off Gas (BOG). Furthermore, while the liquefied gas storage tank is empty, the internal temperature remains higher than the temperature of the injected liquefied gas due to natural heat penetration from the outside. Consequently, when bunkering operations are performed to inject liquefied gas into the storage tank, the supplied gas vaporizes, generating a large amount of Boil-Off Gas. Therefore, conventionally, the generated Boil-Off Gas was simply released to the outside or burned, but this resulted in energy waste as the Boil-Off Gas could not be utilized. In addition, when bunkering operations are carried out to inject liquefied gas into a liquefied gas storage tank, some liquefied gas remains in the bunkering line. Conventionally, when the liquefied gas is LNG, the remaining liquefied gas in the bunkering line is purged using nitrogen, an inert gas. However, when the liquefied gas is hydrogen, since the boiling point of nitrogen gas is -196°C, which is higher than the boiling point of liquefied hydrogen -253°C, problems such as the bunkering line becoming blocked or valves becoming stuck occur when nitrogen is used to purge the bunkering line. Therefore, there is a need to solve the problem of nitrogen freezing in the bunkering line and to efficiently treat the evaporated gas generated in the liquefied gas storage tank. FIG. 1 illustrates an evaporative gas treatment system according to an embodiment of the present invention. FIG. 2 illustrates a bunkering line purging process using evaporated gas according to an embodiment of the present invention. FIG. 3 illustrates the process of supplying evaporated gas to a low-pressure fuel demand source according to an embodiment of the present invention. FIG. 4 illustrates the process of supplying evaporated gas to a high-pressure fuel demand source according to an embodiment of the present invention. Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted. In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are intended merely to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by these terms. Where it is stated that a component is "connected," "combined," or "joined" to another component, it should be understood that the component may be directly connected or joined to the other component, but that another component may also be "connected," "combined," or "joined" between each component. Below, an evaporative gas treatment system (10) according to an embodiment of the present invention will be described. FIG. 1 illustrates an evaporative gas treatment system (10) according to an embodiment of the present invention. Referring to FIG. 1, an evaporative gas treatment system (10) according to an embodiment of the present invention may be provided, comprising: a liquefied gas storage tank (100); a bunkering line (L10) connected from a manifold (110) to the liquefied gas storage tank (100); an evaporative gas supply line (L20) that supplies evaporative gas generated from the liquefied gas storage tank (100) to a fuel demand place (300); and a first bypass line (L31) that branches off from the evaporative gas supply line (L20) and is connected to the bunkering line (L10); and a evaporative gas treatment system (10) that purges the bunkering line (L10) with evaporative gas supplied through the first bypass line (L31). The liquefied gas storage tank (100) can store liquefied gas in a liquid state. The liquefied gas storage tank (100) may be provided as a C-Type tank of the pressure vessel type having a cylindrical struct