A method for monitoring a device for regulating the flow of a gas and a regulating system employing said method

Abstract

A method for monitoring a device (1) for regulating the flow of a gas, comprising a flow conduit (2) and a shutter assembly (3) that defines a restriction (4) in the flow conduit (2). The method comprises the following operations: causing the transit of gas through the flow conduit (2); defining a sequence of time intervals (Z1...Zn) of corresponding durations (t1...tn); during each time interval(Zi), determining a value of density (di) and a value of velocity (Vi) of the gas at the restriction (4); calculating the product of the value of density (di), of the value of velocity (Vi), of the duration (ti) of the time interval (Zi) and of a correction coefficient (ki) to obtain a corresponding value of equivalent wear (ui); for each time interval (Zi), adding all the values of equivalent wear (u1... ui) calculated for the current time interval (Zi) and for the preceding time intervals (Z1...Z(i-1)) to obtain a cumulative value (cui); comparing the cumulative values (cui) with a predefined limit value (cu*), corresponding to a condition of maximum wear allowable for the shutter assembly (3), to obtain an indication of the condition of efficiency of the shutter assembly (3).

Description

technical field [0001] The invention relates to a method for monitoring a device regulating the flow of gas, in particular for a pressure reducer or for a flow control valve, of the type that can be used, for example, in networks for the distribution of compressed gas, in particular natural gas. [0002] The invention also relates to a regulating system employing the aforementioned method. Background technique [0003] As is known, natural gas is distributed to consumer installations through a suitable distribution network which keeps the delivery pressure to the consumer installations as constant as possible regardless of the supply pressure of the network and the flow rate provided. [0004] Delivery pressure is ensured to be maintained at a constant level by a regulating system, which may include pressure reducers positioned along the piping of the distribution network, which reduce the supply pressure of the network to the value required by the user's installations. In ...

AI Technical Summary

Problems solved by technology

[0013] A disadvantage of the aforementioned prior art is that the criteria establish the time interval between one maintenance operation and the next based on theoretical criteria without taking into account the actual operating history of each pressure reducer

[0014] Therefore, in many practical situations, the aforementioned criteria are found to be overly cautious and can lead to maintenance work being carried out while the pressure reducer is still fully functional and thus it can still ensure safe operation for a certain period of time

[0015] On the other hand, it is also possible that unusual heavy usage of the pressure regulator requires maintenance earlier than planned

[0016] In this case, the performance of the pressure regulator can deteriorate before maintenance work can be performed, resulting in a possible risk to system safety

[0017] Similar disadvantages apply to flow control valves, which also include closures commanded in such a way as to control gas flow

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