초록 ▼

An aboveground storage tank is provided with a mass balance system for quantitative detection of leakage of liquid from a tank. Arrays of temperature sensors measure the exterior wall temperature of the tank and temperature sensors in an open-ended standpipe within the tank measure the temperature o

An aboveground storage tank is provided with a mass balance system for quantitative detection of leakage of liquid from a tank. Arrays of temperature sensors measure the exterior wall temperature of the tank and temperature sensors in an open-ended standpipe within the tank measure the temperature of stored liquid. The temperature measurements and measurements of liquid level change in a chamber mounted at the upper end of the standpipe are polled at intervals to detect changes of the mass of liquid within the tank.

대표청구항 ▼

A method for quantitative detection of leakage from an aboveground storage tank, defined by a surrounding tank shell, a tank top and a tank bottom and containing liquid whose level is below said tank top, comprising vertically positioning in the tank a standpipe with an open bottom end thereof on sa

A method for quantitative detection of leakage from an aboveground storage tank, defined by a surrounding tank shell, a tank top and a tank bottom and containing liquid whose level is below said tank top, comprising vertically positioning in the tank a standpipe with an open bottom end thereof on said tank bottom permitting said liquid to enter the standpipe, said standpipe extending upward to an open top end thereof above said liquid level, said standpipe further having a liquid level measuring chamber portion within the length of the standpipe and having a length portion above and a length portion below the level of said liquid within the tank; positioning a first array of vertically spaced temperature sensors within and along said standpipe including said chamber portion for measuring temperatures of liquid within the standpipe and the liquid level measuring chamber portion; and positioning a second array of vertically spaced temperature sensors against the outside of said shell of the tank for measuring temperatures along the tank shell; and including the steps of: polling the sensors of said first and second arrays to obtain average temperatures of the liquid within the standpipe including said chamber portion and of the tank shell at a time n; measuring any change in the level of liquid within the liquid level chamber portion during a time interval between the time n and a time n+1; polling the sensors of said first and second arrays to obtain average temperatures of the liquid within the standpipe including said chamber portion and of the tank shell at the time n+1; comparing the average temperatures at the times n and n+1 to obtain temperature difference measurements for the liquid within the standpipe including said chamber portion representing the change in the average temperature of the liquid in the tank and a change in the average temperature of the tank shell related to a change in the cross sectional area of the tank; and using the temperature difference measurements and the liquid level change measurements to determine an amount of leakage from the tank during said time interval.