PURPOSE: To enable abnormalities or failures of a flow meter and the accident of leakage of a piping to be discriminated and detected by finding the ratio of the flow rate total value on the outflow side in relation to the flow rate total value to be measured on the inflow side and judging abnormalities of a flow meter when the ratio of the flow rate satisfies the specified relationship.
CONSTITUTION: When an abnormality detecting device is applied to a blast furnace gas transport piping system, generation flow meters 11, 12 are attached to inflow pipes p1, p2 extending to a blast furnace gas transporting pipe line P, and consumption side flow meters 13 to 17 are attached to outflow pipes p3 to p7. The generation side flow rate total values ΣF1, ΣF0 obtained from a generation side flow rate calculator 20 and a consumption side flow rate calculator 21 are input, the flow rate ratio Fr is found by a flow rate calculator 22, and abnormalities of the flow meters are judged when the flow rate Fr satisfies the formula Fr>1-, or 1->Fr≥1-λ. On the other hand, when the flow rate ratio Fr satisfies the formula Fr<1-λ, leakage caused by damage of the pipe line of a piping system is judged. The letter is indicates properties of fluid and the error ratio to be determined from the pipe diameter, and the letter λ indicates the ratio of the leakage amount in relation to the inflow side total flow rate.
