| 摘要 |
<p>PURPOSE: To reduce erroneous reports of sensing of oil leakage when the wind is blowing by increasing the width of a dead zone of liquid level fluctuations as an instantaneous wind speed signal increases. CONSTITUTION: In an oil storage tank 11 provided with an inlet valve 13 and outlet valve 14, a liquid level signal (a) from a liquid level sensor 15 for sensing vertical movements of a floating roof 12 which moves in association with liquid level, instantaneous wind speed signal (b) from a wind speed sensor 16 provided near the roof 12, and closing signals (c, d) of the valves 13, 14 are inputted into an oil leakage monitoring device 17. After sensing that the valves 13, 14 of the tank 11 have been closed after receipt and shipment of oil, a dead zone of sensing of liquid level fluctuations is selected based on average wind speed calculated from the signal (b) and when the signal (a) inputted from the sensor 15 has exceeded the selected dead zone, an oil leakage is correctly sensed, which leakage is reported through a CTR 18 or the like. As a result, an erroneous report such that fluctuation of liquid level due to wind speed is taken as occurrence of leakage of oil or occurrence of leakage can be avoided.</p> |
