Signal conditioning integrated circuit for wire-mesh sensors applied to multiphase flow monitoring
Complex impedance measurement, multiphase flow, wire-mesh sensors, CMOS integrated circuits
In the petrochemical industry, accurate control and monitoring of mixtures composed of oil, gas and water (multiphase) has led to the development of research techniques based on tomographic imaging. In order to achieve good temporal resolution, wire-mesh sensor technology has been developed over the last decade. These sensors, which are inserted inside the pipes, consist of a mesh of electrodes that perform the measurement of complex impedance of fluids. Despite the intrusive nature, multiphase flow images are generated without the use of iterative reconstruction algorithms. This work proposes an integrated circuit (IC) to perform the conditioning of a 4x4 wire-mesh sensor mesh, applied to the determination of the phase fraction in multiphase flows. The integration would reduce the size and power consumption of conditioning circuits, compared to implementations of existing systems that use discrete components. The chip is composed of the following blocks: a transimpedance amplifier, which converts currents from the sensors into voltage; A phase-synchronous demodulator that provides phase and quadrature voltage signals that are functions of the electrical properties of the fluids (permittivity and conductivity); And analog-to-digital converters, which perform the conversion of the signals to the digital domain. The integrated circuit will be designed to be manufactured using standard 180 nm CMOS technology.