| 摘要 |
<p>PURPOSE:To promote a sharp reduction in power required for a pressure rise after liquefaction by storing cryogenic liquefied natural gas in a cold storage agent in advance in the daytime when a demand of city gas is much, and liquefying boil-off gas by means of the cold stored in the cold storage agent in the nighttime when the demand of the city gas is lesser. CONSTITUTION:In the daytime, a boil-off gas (BOG) being produced out of an ING storage tank is boosted high and, after being pre-cooled, it is mixed in a sufficient quantity of liquefied natural gas for liquefying this BOG, forming an ING single-layer flow. Next, this single-layer flow is taken into a cold storage vessel with a built-in cold storage agent, having this flow cooled and congealed, then this LNG single-layer flow is boosted up to delivery pressure with a pump and, after using this for the preliminary cooling of the BOG, it is fed to an LNG vaporizer for vaporization. On the other hand, in the nighttime, the boil-off gas being produced out of the LNG storage tank is boosted of its pressure and, after being pre-cooled, it is mixed in the LNG likewise, forming a gas-liquid two layer flow between LNG and BOG, and this flow is taken into the cold storage vessel being in a cold storage state, thus the BOG is liquefied, and the LNG single-layer flow is made to flow back to the ING storage tank.</p> |
