Development of Conductivity Sensors for Multi-Phase Flow Local Measurements at the Polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI)

Abstract

This paper describes all the procedures and methods currently used at UPV (Universitat Politécnica de Valencia) and UJI (University Jaume I) for the development and use of sensors for multi-phase flow analysis in vertical pipes. This paper also describes the methods that we use to obtain the values of the two-phase flow magnitudes from the sensor signals and the validation and cross-verification methods developed to check the consistency of the results obtained for these magnitudes with the sensors. First, we provide information about the procedures used to build the multi-sensor conductivity probes and some of the tests performed with different materials to avoid sensor degradation issues. In addition, we provide information about the characteristics of the electric circuits that feed the sensors. Then the data acquisition of the conductivity probe, the signal conditioning and the data processing including the device that have been designed to automatize all the measurement process of moving the sensors inside the channels by means of stepper electric motors controlled by computer are shown in operation. Then, we explain the methods used for bubble identification and categorization. Finally, we describe the methodology used to obtain the two-phase flow information from the sensor signals. This includes the following items: void fraction, gas velocity, Sauter mean diameter and interfacial area concentration. The last part of this paper is devoted to the conductance probes developed for the annular flow analysis, which includes the analysis of the interfacial waves produced in annular flow and that requires a different type of sensor.

Study of Liquid Film Behaviour in Vertical Downward Air–water Annular Flow

“…The most important element to accomplish the measurements in the GEPELON facility is the conductance probes represented in Fig. 2(a) and detailed in Muñoz-Cobo et al [6] and Cuadros et al [7]. These devices take advantage of the conductive properties of water to detect the film thickness near the wall.…”

Experimental Study of the Interfacial Waves Produced in Upward Vertical Annular Flows When Varying the Liquid-Phase Surface Tension

“…To estimate the characteristics of the interfacial waves we use a conductance probe. The conductance probe used in these measurements is described in reference [11]. The physical basis of the conductance sensors is the dependence of the water conductivity on the film thickness value [12].…”

Experimental investigations on electrical-insulation performance of Al2O3 coatings for high-temperature PbLi liquid-metal applications

“…Such an electrical-insulation, by virtue of its non-porosity towards LM ingress, is also envisaged to act as a corrosion-protection layer as well as Tritium Permeation Barrier (TPB) [4, 8-11, 14, 20, 25-37]. Additionally, development of a few speci c diagnostic tools for LM systems necessitates provision of electrical-isolation over a substantial length [38][39][40][41][42].…”