Simulation method for the operation of magnetic flowmeters

The issues of testing magnetic flowmeters for liquid metal and studies of their metrological characteristics are considered. The existing liquid metal pouring flowmeters are unsuitable for experimental studies of error components, therefore it is necessary to use simulation methods to simulate the operation of magnetic flowmeters. The tests require the liquid metal plants or methods that allow you to examine flowmeters without plants that can reproduce the flow rate in various operating modes. By analogy with the simulation method of water flowmeters research, a simulation method for modeling the operation of magnetic flow meters for liquid metals has been developed. The proposed method estimates the error of magnetic flowmeters in operation mode. The components of the measurement error of flowmeters caused by a violation of the geometry of the primary converter (the size and location of the electrodes, the design of the inductor coils), a change in the hydrodynamic regime, and the temperature dependence of the shunting effect of the pipeline wall are considered. A representation is obtained for the signal of the primary converter in the form of an integral over the inner surface of the pipe from the product of the radial component of the magnetic field and the surface weight function. The expression found can be interpreted as a magnetic flux through an induction coil located on the inner surface of the channel, the turns of which are drawn along the level lines of the surface weight function. This expression can be interpreted as a magnetic flux through an induction coil located on the inner surface of the channel, the coils of which are placed along the lines of the level of the surface weight function. If such a coil is inserted in the flowmeter channel, the time-integrated voltage induced in the coil will be proportional to the voltage generated between the electrodes of the flowmeter. Since the surface weight function depends on the geometry of the channel, the kinematic structure of the flow, the ratio of wall and liquid conductivities, therefore, the metrological characteristics of the flowmeter can be studied by the simulation method when each of the above factors changes individually or together. To do this, it is enough to make an induction coil taking into account the surface weight function that reflects any of the factors under study or their combination. Simulation methods for studying the dependences of magnetic flowmeter signals on the velocity distribution in the channel and the shunting effect of the pipeline wall are considered.

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