CN-117043057-B - Pressure adjustment method for storage tank in ship

Abstract

The ship is provided with a hull, a storage tank provided in the hull and storing liquefied carbon dioxide, and a carbon dioxide injection unit provided in the hull and capable of injecting carbon dioxide gas having a temperature and a pressure higher than those of the carbon dioxide in the storage tank into the storage tank.

Inventors

• MORIMOTO SHINSUKE
• ABE KAZUYA
• UEDA SHIN

Assignees

• 三菱造船株式会社

Dates

Publication Date

20260508

Application Date

20220325

Priority Date

20210331

Claims (5)

1. 1.A ship is provided with: A hull; a storage tank provided in the hull and storing liquefied carbon dioxide, and A carbon dioxide injection unit which is provided in the hull and is capable of injecting carbon dioxide gas having a higher temperature and a higher pressure than those of the carbon dioxide gas in the storage tank into the storage tank, The carbon dioxide injection unit injects the carbon dioxide gas into the storage tank when the sloshing of the liquefied carbon dioxide stored in the storage tank reaches a predetermined level.
2. 2. The vessel of claim 1, wherein, The carbon dioxide injection unit injects the carbon dioxide gas into a gas phase of carbon dioxide in the storage tank.
3. 3. The vessel according to claim 1 or 2, wherein, The carbon dioxide injection unit injects the carbon dioxide gas into a liquid phase of carbon dioxide in the storage tank.
4. 4. The vessel according to claim 1 or 2, wherein, The carbon dioxide injection unit injects the carbon dioxide gas into the storage tank when the pressure in the storage tank is equal to or lower than a pressure lower limit value set to be equal to or higher than a triple point pressure of the liquefied carbon dioxide.
5. 5. A pressure adjustment method of a tank in a vessel, which is the pressure adjustment method of a tank in a vessel according to any one of claims 1 to 4, comprising: a step of acquiring at least one of information on the pressure in the storage tank and information on the sloshing of the liquefied carbon dioxide stored in the storage tank, and And injecting the carbon dioxide gas into the storage tank by the carbon dioxide injection unit based on the acquired information.

Description

Pressure adjustment method for storage tank in ship Technical Field The present invention relates to a ship and a method for adjusting the pressure of a tank in the ship. The present application claims 2021, 3 and 31 to the priority of japanese patent application No. 2021-059785 of japanese application, and the contents thereof are incorporated herein. Background Patent document 1 discloses a structure for transporting dry ice precipitated by spraying liquid carbon dioxide in a cabin. Patent document 2 discloses a method of transporting carbon dioxide in a state of compressing carbon dioxide gas at a storage tank pressure of 15kg/cm 2 and at normal temperature (for example, 0 to 30 ℃). Technical literature of the prior art Patent literature Patent document 1 Japanese patent laid-open No. 5-180394 Patent document 2 Japanese patent application laid-open No. 2004-125039 Disclosure of Invention Technical problem to be solved by the invention When liquefied carbon dioxide is contained in a tank provided in a ship body, the liquefied carbon dioxide may be solidified to generate dry ice for the following reasons. That is, the pressure of the liquefied carbon dioxide within the storage tank corresponds to the storage tank application pressure. The pressure at the triple point where the gas phase, the liquid phase and the solid phase of liquefied carbon dioxide coexist (triple point pressure) is higher than the triple point pressure of liquefied natural gas (LNG: liquefied Natural Gas) or liquefied petroleum gas (LPG: liquefied Petroleum Gas), and if the tank is depressurized at the time of application, the triple point may be reached. If the pressure of the liquefied carbon dioxide is equal to or lower than the triple point pressure, flash evaporation of the liquefied carbon dioxide may occur. Then, the temperature of the liquefied carbon dioxide remaining without evaporation is lowered due to the vaporization latent heat of the flash evaporation of the liquefied carbon dioxide, and the liquefied carbon dioxide may be solidified in the storage tank to generate dry ice. Therefore, the tank application pressure (the design pressure of the tank) is set so that the pressure of the liquefied carbon dioxide does not become equal to or lower than the triple point pressure. However, if the tank application pressure is set to be significantly higher than the triple point pressure of liquefied carbon dioxide, the tank itself or a pipe connected to the tank must be set to a pressure-resistant structure corresponding to the tank application pressure (design pressure of the tank), which leads to an increase in cost. For example, when liquefied carbon dioxide in the storage tank shakes with the swing of the hull, dynamic pressure of the liquefied carbon dioxide increases according to the flow rate of the liquefied carbon dioxide, and static pressure of the liquefied carbon dioxide decreases. As the static pressure of the liquefied carbon dioxide in the storage tank thus generated decreases, the liquefied carbon dioxide may solidify in the storage tank to generate dry ice. Further, since dry ice is deposited on the bottom of the tank when the dry ice is generated in the tank due to the density of the dry ice being higher than that of liquefied carbon dioxide, sublimation of the dry ice may take a long time even after the pressure in the tank is restored. The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a ship and a method for adjusting the pressure of a tank in the ship, which can smoothly perform the tank application by suppressing the generation of dry ice. Means for solving the technical problems In order to solve the above problems, a ship according to the present invention includes a hull, a tank, and a carbon dioxide injection unit. The storage tank is arranged on the ship body. The storage tank stores liquefied carbon dioxide. The carbon dioxide injection part is arranged on the ship body. The carbon dioxide injection unit may inject carbon dioxide gas having a higher temperature than carbon dioxide in the storage tank into the storage tank. The method for adjusting the pressure of the tank in the ship according to the present invention is a method for adjusting the pressure of the tank in the ship as described above, and includes a step of acquiring information and a step of injecting carbon dioxide gas into the tank. In the step of acquiring information, at least one of information on the pressure in the storage tank and information on the sloshing of the liquefied carbon dioxide stored in the storage tank is acquired. In the step of injecting the carbon dioxide gas into the storage tank, the carbon dioxide gas is injected into the storage tank by the carbon dioxide injection unit based on the acquired information. Effects of the invention According to the ship and the method for adjusting the pressure of the tank in the ship of the present in