| 摘要 |
PROBLEM TO BE SOLVED: To reduce the amt. of water sprayed in an LNG vaporizer to thereby reduce the power cost of a seawater pump. SOLUTION: In the method for running a seawater pump 8 by calculating the amt. of seawater supplied by the pump 8 by using the higher value of the two amts. of water: the necessary amt. of sprayed water obtd. by comparing the temp. of seawater at the entry side of an LNG evaporator 1 to be monitored with the designed conditions of the evaporator 1 and the amt. of sprayed water at the film-breaking limit, as the set amt. of sprayed water, the temps. of sprayed water at tubes 4 near the lower header part 3 of the panel 5 of the evaporator 1 are measured along the right-and-left direction to calculate the difference between each of the above-obtd. temps. and the temp. of seawater at the entry sides of each of the tubes 4; then the apparent amt. of sprayed water is calculated about each tube from the above-obtd. temp. difference, the flow rate of the LNG, the enthalpies of the entry-side LNG and the exit-side gas, and the specific heat of water sprayed; and the amt. of seawater supplied by the pump 8 is increased when the apparent amt. of sprayed water becomes lower than the above set amt. |
