LEAKAGE DETECTION METHOD OF GAS TRANSPORTATION LINE

摘要

PROBLEM TO BE SOLVED: To improve reliability in gas leak detection by excluding a pressure head wave that occurs due to a primary factor other than leakage on a main line for reducing an erroneous alarm.;SOLUTION: Variation in pressure detected by a pressure detection units 4 and 5 is sent to an arithmetic unit 6. The arithmetic unit 6 constantly monitors the variation in pressure in the pressure detection unit 4, and monitors a negative pressure change. When the arithmetic unit 6 detects a negative pressure change rate (a change rate exceeding a fixed threshold), the arithmetic unit 6 obtains the detection time of the negative pressure change and the ratio of the size of the pressure change rate detected by the pressure detection units 4 and 5. Then, the ratio of the size of the pressure change rate is compared with a preset threshold. When the ratio of the size of the pressure change rate is smaller than the threshold, it is determined that the pressure peak wave is propagated from the side of a main line 1. When the ratio of the size of the pressure change rate is equal to or larger than the threshold, it is judged that the pressure head wave is due to the increase in the amount of gas supply in the gas supply station.;COPYRIGHT: (C)2004,JPO