| 摘要 |
<p>PURPOSE:To reduce an installation cost and a running cost, by increasing and decreasing the pressure in a liquified gas storage tank to control the evaporation quantity of a liquified gas. CONSTITUTION:Connected to a LNG storage tank are a liquid extraction line 7, boiloff gas line 8, evaporator 9, gas holder 10, control valves 12-14, control device 15, input program 16 and pressure sensor 17. Set in the input program 16 is a target value of a boiloff quantity varying with a time, and the target value is inputted to the control device 15. The boiloff quantity is computed according to detection quantities from a thermometer 18 for detecting a temperature in the tank, a pressure sensor 17, a a flow meter 19 and a level meter 20, and is adjusted by control valves 12 and 13 and a blower 11. In a time zone when the amount of use is decreased, for example, the control valves 12 and 13 are controlled to be closed so as to increase the pressure in the tank.</p> |
