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ENCIT 2020
18th Brazilian Congress of Thermal Sciences and Engineering
EVALUATION OF AN AUTOMOTIVE INJECTOR FOR DROPLETS GENERATION IN THE STUDY OF DISPERSED FLOW FILM BOILING IN LOCA CONDITIONS
Submission Author:
Eduardo Telli , RS
Co-Authors:
Eduardo Telli, Carlos Roberto Altafini, Giovani Dambros Telli, Arthur Vieira da Silva Oliveira, Michel Gradeck
Presenter: Eduardo Telli
doi://10.26678/ABCM.ENCIT2020.CIT20-0032
Abstract
In order to improve an experimental workbench used to study the heat and mass transfer of a Pressurized Water Reactor (PWR) during a loss-of-coolant accident (LOCA) at sub-channel scale, has been emerged a demand for the replacement of a piezoelectric injector for another one capable to provide higher flow rate of injected water. These injected droplets are mixed with water vapor at high temperature, providing a dispersed steam-droplets flow that is injected in the test section. This work is an experimental characterization of a Marelli™ IWP220 electromagnetic automotive injector operating with demineralized water. The main purpose is to understand how the injector mass flow, droplet velocity and diameter vary according to adjustable parameters such as pressure injection and duty cycle. Scale weight apparatus was used to measure sprayed water mass through certain time to obtain mass flow rate and a Phase Doppler Anemometry (PDA) system to measure the droplets velocity by Doppler Effect and their diameter by phase difference. The results provided characteristic curves regarding these parameters, which in turn serve for evaluating and comparing injection capability to supply the desired droplet characteristics for dispersed flow film boiling studies. Droplet velocity rising with pressure, smaller droplets losing its kinetic energy to air friction and transient behavior of the electromagnetic injector were some noticeable effects in this work’s results. The range of droplets diameters and liquid volume fraction values was found to be closer to LOCA conditions than with the piezoelectric injector. Moreover, the latter has no mass flow rate control besides pressure variation, also indicating that the former suits better for LOCA experimental studies.
Keywords
PWR Reactors, LOCA, PDA, Automotive injection, Droplet size distributions, Droplet velocity
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